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Please write an abstract with title: Remote Sensing Image Change Captioning With Dual-Branch Transformers: A New Method and a Large Scale Dataset, and key words: Feature extraction, Transformers, Task analysis, Remote sensing, Visualization, Semantics, Image recognition. Abstract: Analyzing land cover changes with multitemporal remote sensing (RS) images is crucial for environmental protection and land planning. In this article, we explore RS image change captioning (RSICC), a new task aiming at generating human-like language descriptions for the land cover changes in multitemporal RS images. We propose a novel Transformer-based RSICC (RSICCformer) model. It consists of three main components: 1) a CNN-based feature extractor to generate high-level features of RS image pairs; 2) a dual-branch Transformer encoder (DTE) to improve the feature discrimination capacity for the changes; and 3) a caption decoder to generate sentences describing the differences. The DTE consists of a hierarchy of processing stages to capture and recognize multiple changes of interest. Concretely, we use the bitemporal feature differences as keys to enhance image features (queries) from each temporal image in the dual-branch Transformer encoder (DTE). To explore the RSICC task, we build a large-scale dataset named LEVIR-CC, which contains 10077 pairs of bitemporal RS images and 50385 sentences describing the differences between images. We benchmark existing state-of-the-art synthetic image change captioning methods on the LEVIR Change Captioning dataset (LEVIR-CC dataset), and our RSICCformer outperforms previous methods with a significant margin (+4.98% on BLEU-4 and +9.86% on CIDEr-D). The attention visualization results also suggest that our model can focus on changes of interest and ignore irrelevant changes.
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Please write an abstract with title: MO-Tree: An Efficient Forwarding Engine for Spatiotemporal-Aware Pub/Sub Systems, and key words: Indexes, Spatiotemporal phenomena, Data structures, Maintenance engineering, Engines, Computational modeling, Limiting. Abstract: For large-scale spatiotemporal-aware publish/subscribe systems, it is critical to design an efficient forwarding engine to achieve fast matching and maintenance of events and subscriptions. For this goal, we propose a novel data structure called MO-Tree to index both subscriptions and events in a unified way. The design philosophy behind MO-Tree is to keep the data structure concise, which manifests in three aspects: limiting the height of MO-Tree, trading space for time, and avoiding node merging and splitting. The difficulty in designing MO-Tree is how to efficiently index width-variable intervals. We present a multi-level cell-overlapping partition scheme and build a theoretical model to optimize the cell width in each level. To evaluate the performance of MO-Tree, a series of experiments is conducted on real-world trace datasets. The experiment results show MO-Tree significantly outperforms the state-of-the-art in terms of matching speed and maintenance cost.
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Please write an abstract with title: On Streaming Coding for Low-Latency Packet Transmissions Over Highly Lossy Links, and key words: Maintenance engineering, Delays, Encoding, Decoding, Out of order, Indexes, Performance analysis. Abstract: This letter investigates streaming coding that places multiple repair packets between source packets to achieve in-order delivery over highly lossy links. While directly analyzing the deterministic placement of repair packets is difficult, a tractable random model is proposed and analyzed to show that a finite in-order delay is achieved. Using it as a guide of the insertion percentage, the delay is then shown to be further reducible by uniformly placing the repair packets, which suppresses the random variation.
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Please write an abstract with title: National Forest Biomass Mapping Using the Two-Level Model, and key words: Forestry, Estimation, Data models, Biological system modeling, Predictive models, Synthetic aperture radar, Satellites. Abstract: This article uses the two-level model (TLM) to predict above-ground biomass (AGB) from TanDEM-X synthetic aperture radar (SAR) data for Sweden. The SAR data were acquired between October 2015 and January 2016 and consisted of 420 scenes. The AGB was estimated from forest height and canopy density estimates obtained from TLM inversion with a power law model. The model parameters were estimated separately for each satellite scene. The prediction accuracy at stand-level was evaluated using field inventoried references from entire Sweden 2017, provided by a forestry company. AGB estimation performance varied throughout the country, with smaller errors in the north and larger in the south, but when the errors were expressed in relative terms, this pattern vanished. The error in terms of root mean square error (RMSE) was 45.6 and 27.2 t/ha at the plot- and stand-level, respectively, and the corresponding biases were -8.80 and 11.2 t/ha. When the random errors related to using sampled field references were removed, the RMSE decreased about 24% to 20.7 t/ha at the stand-level. Overall, the RMSE was of similar order to that obtained in a previous study (27-30 t/ha), where one linear regression model was used for all scenes in Sweden. It is concluded that, using the power law model with parameters estimated for each scene, the scene-wise variations decreased.
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Please write an abstract with title: Facial feature tracking combining model-based and model-free method, and key words: Facial features, Tracking, Mouth, Karhunen-Loeve transforms, Computer science, Computer vision, Content addressable storage, Video sequences, Data mining, Application software. Abstract: We propose a novel facial feature tracker, which integrates model-free and model-based method to reliably track dense facial features with complex non-rigid motions in low quality video sequence. The tracker consists of the mouth motion model part and the enhanced KLT tracker part. There are three key elements in our algorithms: dense facial feature tracking, noise removal with global rank constraints and characteristic non-rigid motion description. Experiments show good results on tracking dense facial features under various expressions, even some facial features have degenerate features.
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Please write an abstract with title: Combination of Auction Theory and Multi-Armed Bandits: Model, Algorithm, and Application, and key words: Program processors, Computational modeling, Costs, Task analysis, Mobile computing, Crowdsensing, Sun. Abstract: The multi-armed bandit (MAB) models have always received lots of attention from multiple research communities due to their broad application domains. The optimal selection problem with unknown rewards in advance, such as ad recommendation in social networks, spectrum access in the cognitive radio field, etc., can be efficiently solved by using MAB models. In an MAB model, given $N$ arms whose rewards are unknown in advance, the player selects exactly one arm in each round, and his goal is to maximize the cumulative rewards over a fixed horizon. Further, a more general model called combinatorial MAB (i.e., CMAB), where $K$ arms can be played simultaneously in each round, is put forward. However, the existing CMAB models neglect the strategic behaviors of the $N$ arms, which indicates that one arm might report false information to increase its own profits. In fact, in many applications such as user selection in crowdsensing, the arms are not the feelingless machines but the rational individuals. To this end, we combine the upper confidence bound (UCB) with auction theory to develop a new algorithm called auction-based UCB (AUCB). We divide the auction-based CMAB problem into two sub-problems: winning arm selection and payment computation problems. For AUCB, we derive an upper bound on regret and prove the truthfulness in one round, individual rationality, and computational efficiency. In addition, we consider an extended situation that some arms may be unavailable in some rounds and the arms will bid inconsistently in different rounds. We devise another algorithm called eAUCB to solve this problem. Extensive simulations are conducted to show the significant performance of the proposed algorithms.
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Please write an abstract with title: A New dv/dt Filter Design Method using the Voltage Reflection Theory, and key words: Design methodology, Simulation, RLC circuits, Voltage, Filtering theory, Inverters, Reflection. Abstract: This paper proposes a dv/dt suppression second-order RLC filter for an inverter-cable-high impedance load system. The dv/dt filter placed at the inverter output is designed purposely to minimize excessive voltage overshoot at the load terminal by reducing dv/dt or voltage pulse rise time. A 500 V unit pulse of inverter source is connected over several cable lengths to a high impedance load with a load reflection coefficient of 0.9. Voltage overshoot in terms of the ratio of rise time to propagation time is analyzed and verified by Matlab/Simulink environment. In addition, a new design method for the second-order dv/dt filter is proposed. From the simulation results, the dv/dt filter is able to reduce a high load peak voltage of approximately 950 V to 588.6 V in a 50m inverter-cable-load system, and increase to 1 µs of rise time at the load terminal.
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Please write an abstract with title: An enhanced hierarchy for (robust) controlled invariance, and key words: Linear systems, Closed-form solutions, Scalability, Aerospace electronics, Control systems, Iterative methods. Abstract: We revisit the problem of computing controlled invariant sets for controllable discrete-time linear systems. Inspired by previous work by the authors, our main idea works in two moves: the problem is lifted to a higher dimensional space, where we provide a closed-form expression for a set whose projection back onto the original space is proven to be controlled invariant. We propose two methods in which the key insight is computing controlled invariant sets by considering periodic control policies. The first method considers hyperboxes that are rendered recurrent and essentially improves computational performance of the authors' previous work, while computing the same sets. The second method relaxes the assumption of recurrent hyper-boxes and yields substantially larger controlled invariant sets as shown in case studies. These methods do not rely on iterative computations and their scalability is illustrated in several examples, which show that none of the methods is strictly better than the other.
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Please write an abstract with title: A Comprehensive Benefit Evaluation Model for Distributed Energy Systems Based on AHP-entropy Weight Method, and key words: Economics, Photovoltaic systems, Weight measurement, Electrical engineering, Asia, Wind power generation, Environmental factors. Abstract: Whether the design scheme of the distributed energy system is reasonable, it is necessary to comprehensively consider the benefits of various aspects for evaluation, and introduce appropriate evaluation methods. This paper comprehensively considers the economic, energy and environmental factors of distributed energy system to construct an evaluation index system. Based on the measurement mathematics method, the subjective and objective weighting methods are combined to make up for the deficiency of using the empowerment alone, and a more scientific and reasonable AHP-entropy is proposed. The power empowerment method establishes a comprehensive benefit evaluation model for distributed energy systems. According to the calculated closeness of the scheme, considering the economic, energy and environmental factors affecting the distributed energy system, giving the advantages and disadvantages of each scheme, it has very important reference significance for realizing the economic operation of the distributed energy system.
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Please write an abstract with title: Continual Human Value Analysis in Software Development: A Goal Model Based Approach, and key words: Stakeholders, Systematics, Adaptation models, Software systems, Analytical models, Alarm systems. Abstract: Software failures that demonstrate violations of human values can result in financial losses, reputation damages and social implications. Therefore, integrating human values into software is vital to satisfy stakeholder needs. However, developing methodological approaches that allow systematic integration of human values throughout the software development life cycle is an open challenge. This paper proposes the Continual Value(s) Assessment (CVA) framework that uses extended goal and feature modeling techniques to support systematic integration, tracing and evaluation of human values in software systems. The CVA framework prescribes (i) brainstorming of value implications of system features based on conventional system artefacts and (ii) the expansion of the existing set of system features to better serve stakeholder values expectations. In a pilot study, we use an emergency alarm system for the elderly to demonstrate the feasibility of the framework. We further discuss the challenges we faced while applying the framework and present the lessons learned from the pilot study.
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3,210
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Please write an abstract with title: Automatic Design of Reliable Systems Based on the Multiple-choice Knapsack Problem, and key words: Fault tolerant systems, Field programmable gate arrays, Design automation, Circuit faults, Redundancy. Abstract: This paper evaluates the practical usage of the Multiple-choice Knapsack Problem (MCKP) solver to automatically select the proper fault mitigation method for each component to maximize the overall fault tolerance of the whole system. The usage of the MCKP is placed into the context with our fault tolerance automation toolkit, the goal of which is to completely automate the process of fault-tolerant system design on a very general level. To achieve our goal, we present our research on Field Programmable Gate Arrays (FPGAs) for which we have developed the specific components in order to support their fault-tolerant design automation. In our particular case study, the MCKP method on the partitioned system was able to find the solution with 18% less critical bits compared to our previous approach, while even lowering the circuit size. The results indicate that by splitting the system into smaller components and applying the MCKP method, considerably better results in terms of critical bits representation can be achieved.
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Please write an abstract with title: Vegetation mapping of herring spawning grounds in British Columbia, and key words: Vegetation mapping, Photography, Filters, Algae, Substrates, Cameras, Aquaculture, Sun, Tides, Oceans. Abstract: A knowledge of the extent and type of shoreline vegetation on which Pacific herring annually deposit adhesive eggs is helpful in determining the amount of spawn deposited and hence the size of the spawning population. Low-level aerial photography was evaluated as a means of preparing maps of shoreline vegetation. Maps of spawning localities in Barkley Sound on the west coast of Vancouver Island were drawn from color infrared and color aerial photographs at a scale of 1:3600. The charts were assessed in terms of accuracy and species composition of vegetation zones by a scuba-diving survey.
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Please write an abstract with title: Multi Output Hybrid Solar Inverter with no Right Half Plane Zero and Reduced Common Mode Leakage Current, and key words: Capacitors, Transfer functions, Microgrids, Switches, Transformers, Inverters, Steady-state. Abstract: A multi output based transformerless hybrid solar inverter with minimum phase property and reduced common mode leakage current for photovoltaic (PV) based residential microgrid applications is proposed in this article. As two inversely coupled magnetic coils are placed between the input and output sides of the proposed transformerless minimum phase hybrid solar inverter (TLMPHSI), there is no right half plane zero (RHPZ) in control-to-DC output voltage transfer function and it behaves as a minimum phase system. Further, a unipolar based sinusoidal pulse width modulation (SPWM) technique is implemented for the switching operation of the proposed TLMPHSI to minimize the high frequency common mode voltage across the PV to ground parasitic capacitor. Also, it regulates both DC and AC load at the same instant. So, the harmful common mode leakage current is reduced in the system. In addition, as the shoot-through issue is resolved, so the reliability of the proposed TLMPHSI is improved. A 280 W experimental set-up of the proposed TLMPHSI is developed to verify its performance.
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Please write an abstract with title: LDPC Decoding With Low Complexity for OFDM Index Modulation, and key words: Communication systems, Simulation, OFDM, Bit error rate, Modulation, Parity check codes, Encoding. Abstract: In this paper, the posterior probabilities of the low-density parity check (LDPC) coded bits are derived for the orthogonal frequency division multiplexing index modulation (OFDM-IM) system to reduce the implementation complexity of LDPC decoding without performance loss. Specifically, the complexity of LDPC decoding is reduced by decomposing the posterior probability of the coded bit into multiple likelihood probabilities, each of which is obtained for each subcarrier of the corresponding OFDM-IM subblock. The results of the complexity analysis indicate that the proposed approach significantly reduces the implementation complexity of LDPC decoding for OFDM-IM compared to the conventional approach. Furthermore, the simulation results confirm that the proposed approach provides the same bit error rate performance as the conventional approach.
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3,214
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Please write an abstract with title: Influence of Perspective on Dynamic Tasks in Virtual Reality, and key words: Task analysis, Cameras, Avatars, Navigation, Virtual environments. Abstract: Users are increasingly able to move around and perform tasks in virtual environments (VEs). Such movements and tasks are typically represented in a VE using either a first-person perspective (1PP) or a third-person perspective (3PP). In Virtual Reality (VR), 1PP is almost universally used. 3PP can be represented as either egocentric or allocentric. However, there is little empirical evidence about which view may be better suited to dynamic tasks in particular. This paper compares the use of 1PP, egocentric 3PP and allocentric 3PP for dynamic tasks in VR. Our results indicate that 1PP provides the best spatial perception and performance across several dynamic tasks. This advantage is less pronounced as the task becomes more dynamic.
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Please write an abstract with title: The Method for Synthesis of Parameters of Devices for Prevention and Post Therapeutic Restoration of Spine Zones, and key words: Magnetic fields, Inductance, Capacitance, Transient analysis, Automation, Coils, Radiation effects. Abstract: The transients process in circuits with variable inductance and capacitance into devices for prevention and post healing of spinal areas have been considered. The method of synthesis of the law for control of external voltage is formed as law of voltage drop, current strength and set of devices parameters. The influence of current-dependent inductance and capacitance on the resulting magnetic field strength and energy costs of the therapy process as a whole is investigated.
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3,216
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Please write an abstract with title: Flat top pole writer design, and key words: Magnetic heads, Numerical analysis, Coils, Chemicals, Lithography, Milling, Writing, Design optimization, Lungs, Testing. Abstract: In this paper, the design and magnetic performance of a new writer design with flat top pole are discussed. In this study, flat top pole heads with throat height of 2.0 /spl mu/m and magnetic track width of 0.28/spl mu/m were made with conventional plating/milling process. Finite element modeling (FEM) was also used to calculate head field and field gradient at the media. Modeling data show that good writing performance can be achieved by optimising the head design and implementing high moment material.
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3,217
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Please write an abstract with title: Scene Text Detection based on Dual-branch Multi-resolution Feature-aware Enhancement Network, and key words: Shape, Conferences, Semantics, Feature extraction, Complexity theory, Reliability, Task analysis. Abstract: Arbitrary shape scene text detection becomes a challenge task due to its background complexity and shape diversity. In this paper, we propose a dual-branch multi-resolution feature-aware enhancement network (DMFE), the lower branch constructs multi-resolution features through a bidirectional feature pyramid network with weights, and the upper branch enhances the perception of multi-scale text at each level through parallel pooling modules with receptive field enhancement. The global and local co-action will integrate high-level semantic information and low-level location information, so as to generate high-quality feature map. Extensive experiments on ICDAR2015, CTW1500 and Total-Text datasets show that the proposed method effectively improves the detection performance of natural scene text.
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3,218
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Please write an abstract with title: A blind adaptation algorithm for decision feedback equalizers with fractionally-spaced feedforward filters, and key words: Decision feedback equalizers, Nonlinear filters, DSL, IIR filters, Blind equalizers, Convergence, Adaptive filters, Feedback circuits, Signal design, Data communication. Abstract: This paper introduces a blind adaptation algorithm for decision feedback equalizers (DFE) which employ an oversampled feedforward filter. The coefficient set of the feedback filter is obtained from a pure recursive filter which is designed to whiten the oversampled input signal in the sense that it minimizes correlations between the original signal and versions of it which are shifted by multiples of the symbol duration. This recursive filter is adapted by the introduced multichannel extension of the hyperstable adaptive filter algorithm (HARF). The forward equalizer is adapted by the standard constant modulus algorithm (CMA). Simulation results show that the introduced technique is able to equalize a class of channels for which the standard CMA algorithm fails to converge and that it also works well in a digital subscriber line (DSL) environment.
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3,219
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Please write an abstract with title: Study for Buildings with IoT System for Energy Management, and key words: Smart buildings, Smart cities, Architecture, Semantics, Government, Regulation, Service-oriented architecture. Abstract: A smart city makes use of sustainable information and communication technology to upgrade the effectiveness and quality of municipal services for inhabitants and government officials while conserving resources. Buildings with energy-efficient control are an essential part of this. The IoT may be able to help. Its goal is to link many heterogeneous devices over the internet, which necessitates a flexible layered architecture that combines things, people, and web services to simplify an application's work. Also, this Paper will offer a customizable Internet of things, hierarchical architectural model, with an overview of each important component enabling intelligent energy regulation in buildings of smart cities. This paper describes an advanced IoT-based energy management system for buildings. A semantics framework is proposed to unify and standardize the modelling of the things that make up the built environment. Appropriate rules are created with the goal of intelligent energy management and the overall Smart Building mode of operation.
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Please write an abstract with title: Analysis of surface roughness scattering and its contribution to conductivity degradation in nanoscale interconnects, and key words: Rough surfaces, Surface roughness, Conductivity, Degradation, Surface resistance, Particle scattering, Frequency, Quantum mechanics, Atomic layer deposition, Adhesives. Abstract: We use a quantum mechanical calculation of momentum loss rates as function of spatial frequency of surface roughness to identify which frequencies contribute most strongly to conductivity degradation. We combine these calculations with surface roughness spectrum from atomic step model matched to AFM data. We find that roughness with period on the order of 300 nm gives greatest contribution to resistance increase, but that scattering from typical Cu surfaces can be expected to be nearly specular. We attribute apparent surface scattering to adhesion/barrier layer properties rather than interface or surface roughness.
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3,221
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Please write an abstract with title: ECG compression using signal dependent frames and matching pursuit, and key words: Electrocardiography, Matching pursuit algorithms, Design methodology, Filter bank, Dictionaries, Wavelet transforms, Signal design, Algorithm design and analysis, Pursuit algorithms, Bit rate. Abstract: This paper describes a general design method for signal dependent frames, or over-complete dictionaries. The design method is developed for block-oriented frames, overlapping frames, and constrained frames, which can be regarded as extensions of, respectively, block-oriented transforms, filter banks, and general filter banks like wavelets. The frames are optimized for sparse representation of a signal class. Using the designed frames and a matching pursuit algorithm it is shown that superior, compared to other methods, sparse representations are achieved for an electrocardiogram signal. It is also demonstrated that compression based on these sparse representations gives excellent performance at low bit rates.
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3,222
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Please write an abstract with title: 3D Modeling of the airport environment for fast and accurate LiDAR semantic segmentation of apron operations, and key words: Laser radar, Semantics, Airports, Three-dimensional displays, Sensors, Atmospheric modeling, Aircraft. Abstract: Airport ground operations must be safe and should avoid capacity backlogs. To that end, the availability of reliable surveillance data capturing important semantic information about the local traffic situation and the operating conditions on the apron and the maneuvering area are essential. Along those lines, LiDAR sensors combined with computer vision algorithms for semantic scene understanding were recently identified to offer a cost-effective, noncooperative surveillance solution that is expected to contribute to the operational goals mentioned above. However little work exists dealing with fast and accurate LiDAR semantic segmentation of such environments. This is partly due to the fact, that state-of-the-art algorithms in LiDAR semantic segmentation heavily rely on large-scale data sets with fine-grained labels. Although some hand-labeled data sets are publicly available, the point-wise annotation of 3D point clouds requires painstakingly work that is extremely cumbersome. Consequently, we propose a simulation-based approach to generate synthetic training data of the apron using a virtual airport environment that integrates a LiDAR sensor model. In this way, arbitrary scenarios captured under different operational conditions including static objects and moving aircraft provide labeled point data. This way, we trained and tested successfully a LiDAR semantic segmentation model emphasizing on aircraft approaching/leaving the gate after arrival/departure, thin structures (poles), airport buildings, and ground-plane. The developed technique provides an important baseline for the expected performance of the trained model on real data. We believe that the resulting framework provides additional visual cues capturing relevant semantic information that potentially assist the controller in complex situations.
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3,223
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Please write an abstract with title: Relative depolarization of the black hole photon ring in GRMHD models of Sgr A* and M87*, and key words: accretion, accretion discs, black hole physics, MHD, polarization, radiative transfer. Abstract: Using general relativistic magnetohydrodynamic simulations of accreting black holes, we show that a suitable subtraction of the linear polarization per pixel from total intensity images can enhance the photon ring feature. We find that the photon ring is typically a factor of ≃2 less polarized than the rest of the image. This is due to a combination of plasma and general relativistic effects, as well as magnetic turbulence. When there are no other persistently depolarized image features, adding the subtracted residuals over time results in a sharp image of the photon ring. We show that the method works well for sample, viable GRMHD models of Sgr A* and M87*, where measurements of the photon ring properties would provide new measurements of black hole mass and spin, and potentially allow for tests of the ‘no-hair’ theorem of general relativity.
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3,224
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Please write an abstract with title: Feature Selection for Evolving Many-Objective Job Shop Scheduling Dispatching Rules with Genetic Programming, and key words: Job shop scheduling, Processor scheduling, Genetic programming, Evolutionary computation, Feature extraction, Dispatching, Standards. Abstract: JSS (Job Shop Scheduling) is a significant and challenging combinatorial optimization issue. Dispatching rules have been successfully used to determine scheduling decisions in the JSS challenges. Genetic programming (GP) has been widely used to discover and develop dispatching rules for various scheduling problems. However, there has been relatively little research into feature selection in GP-HH for many-objective JSS. In many conflicting objective contexts, it's also vital to quantify the contribution of features. This work presents a new two-stage GP-HH methodology for many-objective JSS with feature selection for changing rules. The quality of the solutions (dispatching rules) after incorporating the many-objective algorithm with feature selection is investigated in this paper. On a four-objective JSS problem, the suggested algorithm (FS-GP-NSGA-III) is compared to the standard GP-NSGA-III. The experimental results show that using GP to pick relevant features improves the algorithm's performance. Furthermore, the proposed technique generates rules that are minimal in size and easy to understand.
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3,225
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Please write an abstract with title: FingerButton: Enabling Controller-Free Transitions between Real and Virtual Environments, and key words: Cross-Reality, Transition techniques, FingerButton, RealWorld, VirtualWorld. Abstract: With the recent Virtual Reality (VR) Head-Mounted Displays (HMDs), users can seamlessly transition between the virtual and real worlds with techniques such as passthrough. These techniques leverage on-device cameras to capture the real world and show users a view of their physical surroundings while wearing the HMDs. However, they often require users to hold a controller or frequently tap on the HMD, limiting the potential for hands-free interaction and thereby hindering a truly immersive and natural VR experience. To address this limitation, we designed FingerButton, a finger-worn push button device that enables seamless transitions between real and virtual environments. We conducted two studies, where the first one explored a set of hand gestures for transitioning between two environments that are commonly used for “mode switching” within realities. In the second study, we compared FingerButton with the best two-hand gesture identified in the first study and other commercially available solutions (e.g., double tap) for a between-reality selection task. The results show that the physical finger button is faster and user-preferred than other techniques for the transition tasks. Overall, this research contributes to understanding and improving the interaction techniques for fluid switching between the real and virtual worlds, thereby enhancing VR user experiences.
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3,226
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Please write an abstract with title: Fuzzy Logic Based Inverter Controller for Stand-Alone Operation of PV/Battery System, and key words: Fuzzy logic, Atmospheric modeling, Simulation, Load management, Inverters, Mathematical models, Batteries. Abstract: The production of electrical energy using renewable energy sources such as wind and solar has increased due to atmospheric pollution and the shortage of conventional energy resources. This paper focuses on modelling and simulation of photovoltaic system with battery storage for isolated operation. The stand-alone system consists of PV system with MPPT controller, battery storage and inverter with its controller. The entire model has been simulated in MATLAB/Simulink platform. A Fuzzy Logic based inverter controller is implemented to get constant AC voltage and frequency. A control strategy for bidirectional DC-DC converter is necessary to obtain constant DC link voltage in the course of change in supply power or load variations. The performance of PV and battery system for stand-alone operation is verified by considering various operational conditions, such as varying PV power and load scenarios. The simulation results establish the satisfactory working of the system under different operating scenarios.
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3,227
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Please write an abstract with title: A dead-time compensation strategy for permanent magnet synchronous motor drive suppressing current distortion, and key words: Permanent magnet motors, Drives, Voltage, Inverters, Synchronous motors, Diodes, Phase distortion, Armature, Induction motors, Rotors. Abstract: This paper presents a dead-time compensation strategy for permanent magnet synchronous motor drives suppressing current distortion. Although dead-time effects can be compensated by a dead-time compensation voltage along with a current polarity, it is difficult to determine the current polarity when the phase currents are clamped to zero. If the current polarity is misjudged, the dead-time compensation operates improperly; as a result, both the phase current and commanded voltage are distorted. In this paper, a misjudge of the current polarity is appropriately corrected by the proposed correction algorithm. Simulation and experimental results confirm that the distortions of the phase current and commanded voltage are suppressed.
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3,228
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Please write an abstract with title: Integration of the freebsd TCP/IP-stack into the discrete event simulator OMNET++, and key words: Discrete event simulation, Protocols, TCPIP, System testing, Operating systems, Linux, Hardware, Telematics, Information science, Intersymbol interference. Abstract: The discrete event simulator OMNeT++, that is programmed in C++, shows a steady growing popularity. Due to its well-structured nature, it is easy to understand and easy to use. A shortcoming of it, however, is the limited number of available simulation models. Especially, for network simulations a validated TCP implementation was missing. In order to avoid a re-implementation of a full-featured TCP, including all potential implementation errors and costly validation tests, we integrated a TCP/IP stack of a real operating system into OMNeT++. In this paper we show that such a port is feasible with reasonable effort and we describe difficulties of the integration process as well as the applied solutions. We also present some evaluation results that outline memory and CPU usage.
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3,229
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Please write an abstract with title: Pricing the American put using a new class of tight lower bounds, and key words: Pricing, Computational modeling, Computational efficiency, Integral equations, Computer science, History, Fitting, Upper bound, Numerical simulation. Abstract: We present new families of lower bounds for the price of the American put option on a dividend paying stock when the stock follows a log normal process and the option can be exercised continuously to a finite horizon T. By put call parity, these bounds can be easily converted to bounds on the price of the American call option on a dividend paying stock. By numerically optimizing these bounds, we obtain tighter bounds on the option price. Our methodology simultaneously furnishes us with an (exponential) exercise strategy. We provide an extensive experimental computation, comparing with convergent binomial tree pricing methods. Our bounds deliver an accuracy comparable to a 2000 step binomial tree, with a computational cost comparable to a 400 step binomial tree.
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3,230
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Please write an abstract with title: An optimised ensemble for antibody-mediated rejection status prediction in kidney transplant patients, and key words: Prediction algorithms, Optimization, Machine learning algorithms, Particle swarm optimization, Training, Supervised learning, Tunneling magnetoresistance. Abstract: Antibody-mediated rejection (AMR) is one of the primary mechanisms of graft loss following organ transplantation. A key difficulty with AMR diagnosis is that symptoms typically manifest when the graft is already damaged beyond repair. Diagnosis is also complicated by differing interpretations of histological data by pathologists, highlighting the urgent need for more quantitative approaches. In this paper we propose an ensemble classifier approach to predicting AMR status from gene expression data. We employ two random oversampling techniques - Synthetic Minority Oversampling Technique (SMOTE) and Adaptive Synthetic Oversampling (ADASYN) - to address the class imbalance in the original data set, and use particle swarm optimisation (PSO) for the selection of the ensemble hyperparameters. Our results demonstrate that applying the PSO-optimised ensemble to the balanced data set provides better predictive performance than the ensemble alone, and represents an important step towards more accurate sub-clinical prediction of AMR status and improved patient risk stratification.
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3,231
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Please write an abstract with title: Exploiting ECC redundancy to minimize crosstalk impact, and key words: Crosstalk, Error correction codes, Decoding, Wire, Error correction, Redundancy, Delay, Fault tolerance, Capacitance, Signal design. Abstract: Signal integrity in high-speed bus designs is put at risk by crosstalk-related-bus delays. This article provides a comprehensive study of the usefulness of error-correcting code (ECC) redundancy in reducing such delays. It shows that dual Rail codes perform better at this task than Hamming codes. We analyze the impact of different ECCs on crosstalk-induced-bus delays (CIBD). We investigate the possibility of exploiting the information redundancy previously necessary to limit CIBD, thus reducing the consequent risk of a system's incorrect operation.
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Please write an abstract with title: Dynamic QoS-Aware Traffic Planning for Time-Triggered Flows in the Real-Time Data Plane, and key words: Quality of service, Schedules, Degradation, Real-time systems, Jitter, Routing, Processor scheduling. Abstract: Many networked applications, e.g., in the domain of cyber-physical systems, require strict service guarantees for time-triggered traffic flows, usually in the form of jitter and latency bounds. It is a notoriously hard problem to compute a network-wide traffic plan, i.e., a set of routes and transmission schedules, that satisfies these requirements, and dynamic changes in the flow set add even more challenges. Existing traffic-planning methods are ill-suited for dynamic scenarios because they either suffer from high computational cost, can result in low network utilization, or provide no explicit guarantees when transitioning to a new traffic plan that incorporates new flows. Therefore, we present a novel approach for dynamic traffic planning of time-triggered flows. Our conflict-graph-based modeling of the traffic planning problem allows for the reconfiguration of active flows to increase the network utilization, while also providing per-flow QoS guarantees during the transition to the new traffic plan. Additionally, we introduce a novel heuristic for computing the new traffic plans. Evaluations of our prototypical implementation show that we can efficiently compute new traffic plans in scenarios with hundreds of active flows for a wide range of settings.
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Please write an abstract with title: Study on the Learners’ Performance Evaluation in Online Teaching with Personal Response Systems, and key words: Performance evaluation, COVID-19, Distance learning, Pandemics, Educational technology, Computer crashes. Abstract: COVID-19 pandemic is unprecedented in its impact on education, forcing a crash course for online teaching programs and technology for students and instructions. Though, some studies have applied personal response systems (PRSs) to online teaching, few researches have experimentally evaluated the effectiveness of PRSs. Learner’s performance, including academic achievement and perception, can inform the effectiveness of using PRSs in online teaching. Therefore, 98 sophomores majoring in “Educational Technology” are selected to evaluate learners’ performance in online teaching with PRSs like UMU, and reached the following conclusions: the test group’s academic achievement was higher than the control group; majority of learners have positive perception, such as learning motivation (LM), learning engagement (LE) and learning satisfaction (LS) towards PRSs. In general, PRSs used in online teaching is efficient, which is a new way to improve the effectiveness of online teaching. Finally, limitations of study and prospects for further research are discussed.
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Please write an abstract with title: Latency-aware Topology Discovery in SDN-based Time-Sensitive Networks, and key words: Knowledge engineering, Wireless communication, Temperature measurement, Network topology, Real-time systems, Topology, Behavioral sciences. Abstract: Time-Sensitive Networking (TSN) is a set of standards currently being defined by the IEEE 802.1 Time-Sensitive Networking Task Group [1] for Real-Time behavior in the network. Software-Defined Networking (SDN) provides a good solution for implementing TSN networks due to its characteristics such as run-time flexibility, benefits in management, cost efficiency, and performance. For achieving Real-Time behavior in TSN networks, the high-priority traffic should be scheduled precisely to fulfill its timing requirements. For this purpose, in SDN-based implementation, the control plane must have a good knowledge of the network topology and the delay in the network to be able to schedule the traffic. In this paper, we propose a topology discovery mechanism for the Central Network Controller (CNC) in TSNs based on the Link Layer Discovery Protocol (LLDP) able to discover accurate link latency characteristics as required for time-aware scheduling without relying on external time synchronization protocols such as PTP. We evaluate its feasibility and assess its performance in terms of required bandwidth and achieved accuracy.
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Please write an abstract with title: A Frequency-Reconfigurable Coaxial Liquid Metal Yagi-Uda Antenna with Arbitrary Directivity, and key words: Liquids, Yagi-Uda antennas, Resonant frequency, Directive antennas, Antenna feeds, Electrolytes, Reflector antennas. Abstract: This paper introduces a reconfigurable Yagi-Uda antenna using liquid metal eutechtic gallium and indium (EGaIn). The antenna consists of three coaxial circular capillaries inserted with electrolyte and certain amount of liquid metal according to their different functions. Arbitrary intended directions in 2D-plane can be realized by changing the position of EGaIn in each capillary electrochemically. The resonant frequency is also adjustable by altering the location of the feed element. The results of HFSS simulation show that the antenna has resonant frequencies of 1.69 GHz and 2.03 GHz with high gain in the intended directions.
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Please write an abstract with title: The electret properties of two kinds of poly(vinylidene fluoride-hexafluoropropylene) copolymer films, and key words: Electrets, Mechanical factors, Casting, Space charge, Temperature, Piezoelectric films, Solvents, Thermal stability, Acoustic transducers, Aluminum. Abstract: P(VDF-HFP) (poly(vinylidene fluoride-hexafluoro-propylene)) copolymer is a new member of PVDF family. In this paper, the electret properties of the two kinds of casting prepared P(VDF-HFP) copolymer films whose content of HFP is 4.7% and 5.9% respectively were discussed with the focus on the influences of mechanically thermal stretching process and of the content of HFP on electret properties of the said copolymer. Experimental results point out that the said copolymer electret film is a polar material, i.e. there exist both oriented dipoles and deposited space charges in the film after charging. The mechanically thermal stretching process not only increases the density of oriented dipoles and deposited space charges but also improves the stability of deposited space charges; however, the increase of HFP content in the copolymer has a negative impact on the density of oriented dipoles and deposited space charges. The measurement result by means of Laser Doppler Vibrometer shows the copolymer in which the HFP content is 4.7% has a notable converse coefficient as high as 130pm/V.
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Please write an abstract with title: Yield statistics for large area ICs, and key words: Statistics, Semiconductor device modeling, Integrated circuit yield, Statistical distributions, Manufacturing processes, Wafer scale integration, Redundancy, Integrated circuit technology, Instruments, Analysis of variance. Abstract: This report will cover an examination of Poisson statistics and their inadequacy to represent defects in large area chips on a wafer. Measurements of defects will be cited and the consequences on redundancy methods will be discussed.
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Please write an abstract with title: A novel frequency synchronization method for wireless OFDM systems, and key words: Frequency synchronization, OFDM, Frequency estimation, Energy efficiency, Computer simulation, Digital video broadcasting, Fading, Channel estimation, Application software, Digital audio broadcasting. Abstract: In this paper, we propose a new frequency synchronization method for wireless orthogonal frequency division multiplexing (OFDM) systems. The method exploits the pilots' energy efficiently by collecting the energy leaked into the neighbor subcarriers, and provides the coarse and fine estimation of the frequency offset at the same time. Furthermore, an adaptive accumulator is used to attain a good tradeoff between the performance and the synchronization time. Computer simulation results demonstrate that the proposed method performs well at various Doppler frequency shifts with a fairly short synchronization time.
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Please write an abstract with title: Integrated bake/chill module with in situ temperature measurement for photoresist processing, and key words: Temperature measurement, Resists, Substrates, Temperature sensors, Lithography, Temperature control, Instruments, Chemicals, Silicon, Open loop systems. Abstract: Thermal processing of photoresist are critical steps in the microlithography sequence. The postexpose bake (PEB) steps for current DUV chemically amplified resists is especially sensitive to temperature variations. The problem is complicated with increasing wafer size and decreasing feature size. Conventional thermal systems are no longer able to meet these stringent requirements. The reason is that the large thermal mass of conventional hot plates prevents rapid movements in substrate temperature to compensate for real-time errors during transients. The implementation of advanced control systems with conventional technology cannot overcome the inherent operating limitation. An integrated bake/chill module with in situ temperature measurement capability has been developed for the baking of 300-mm silicon wafers. The system provides in situ sensing of the substrate temperature. Real-time closed-loop control of the substrate temperature is thus possible as oppose to conventional open-loop control of the substrate temperature. Experimental results are provided to demonstrate a complete thermal cycle.
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Please write an abstract with title: AI-based Blockchain for the Metaverse: Approaches and Challenges, and key words: Metaverse, Scalability, Ecosystems, Buildings, Smart contracts, Feature extraction, Blockchains. Abstract: The recent advances in AI have enabled novel approaches and remarkable enhancements in the provision of existing services and applications. The metaverse is one of the emerging applications that got the advantages of this technological progression. Due to the cooperation between several cutting-edge technologies including IoT, digital twin (DT), and big data, the metaverse highly relies on the manipulation of an immense amount of gathered data. In this context, security is a major challenge, and as such, blockchain brings several advantages to the metaverse ecosystem as it allows secure and transparent data storage. However, with the dynamic nature of such an ecosystem and the fast variation in its AI-based services, the traditional blockchain features (e.g. smart contracts and consensus protocols) will face big challenges to meet the needed dynamic service requirements and scalability. This positioning paper proposes the concept of using a blockchain governed by AI to leverage the various features and advantages of blockchain services. The paper provides a review of the role of blockchain in the metaverse, challenges that arise, and then the role of AI in building intelligent blockchain features and their impact on the metaverse ecosystem.
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Please write an abstract with title: Nonlinear PDE-Based control of the electron temperature in H-mode tokamak plasmas, and key words: Plasma temperature, Toroidal magnetic fields, Heating systems, Stability analysis, Tokamak devices, Lyapunov methods. Abstract: This paper studies the exponential stability of the electron temperature profile in H-mode tokamak plasmas. Lyapunov stability analysis is carried in an infinite-dimensional setting on the nonlinear partial differential equation describing the dynamics. The nonlinear components are handled with the sum of squares framework, in order to prove the exponential convergence of the Lyapunov function. Nominal stability of the system is first checked, then a controller is proposed to improve the convergence rate of the closed-loop system. The controller algorithm including the input constraints is then used for profile tracking on the RAPTOR simulator with different challenging scenarios.
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Please write an abstract with title: The role of neural networks in telerehabilitation, and key words: Neural networks, Intelligent networks, Sensor arrays, Neurofeedback, Electromyography, Medical services, Automation, Medical diagnostic imaging, Neuromuscular, Biomedical informatics. Abstract: Delivery of rehabilitative health care at remote distances becomes feasible with neural net-assisted automation. Using neural nets trained to recognize characteristics of extensive/reflective responses, a series of rules can be invoked to guide functional restoration for individuals with neurological disorders of movement. The key to reeducation follows from sensory feedback substitution.
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Please write an abstract with title: Protocol-based conflict resolution for finite information horizon, and key words: Aircraft, Protocols, Aerospace control, Air safety, Air traffic control, Topology, Optimization methods, NASA, Laboratories, Graph theory. Abstract: Proposes a protocol-based multiple aircraft conflict resolution for a finite information horizon, in which the communication range of an aircraft is finite. A protocol for multiple aircraft conflict resolution for an infinite information horizon is presented and then this protocol is extended to a finite information horizon problem using graph theory. Communication topology among aircraft is important for the finite information horizon problem and is modeled by a graph called the communication graph. We develop a protocol for multiple-aircraft conflict resolution based on the communication graph and show the safety of the protocol. Finally, we validate our protocol through simulations with a dynamic aircraft model.
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Please write an abstract with title: The results of WINDS experiments of NICT, and key words: WINDS, Ka-band, NICT fundamental experiments. Abstract: The Wideband InterNetworking engineering test and Demonstration Satellite (WINDS) was developed for the research of high-data-rate satellite communication technologies using Ka-band. WINDS was launched on February 23, 2008 and completed its operation on February 27, 2019. The National Institute of Information and Communications Technology (NICT) planned and conducted various experiments, such as satellite communication experiments for disaster countermeasures, an orthogonal frequency-division multiplexing transmission experiment, and mobile satellite communication experiments, using a small vehicle earth station, an airborne earth station, and a seaborne earth station.
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Please write an abstract with title: Design of General Flux-Controlled and Charge-Controlled Memristor Emulators Based on Hyperbolic Functions, and key words: Memristors, Integrated circuit modeling, Mathematical models, Voltage, Capacitors, Switching circuits, Semiconductor device modeling. Abstract: In this article, a general memristor model emulator based on the hyperbolic function is proposed. Based on the mathematical model of hyperbolic function memristor, a general circuit model emulator is designed. The general circuit can realize memristor models of different hyperbolic functions by controlling the state of switches in the circuit. The advantage of the emulator is that it can realize three different mathematical models of hyperbolic function and be easily integrated. The circuit of the hyperbolic function memristor model conforms to three basic characteristics of the mem-element, so it can be regarded as a memristor element. Finally, the model of charge-controlled memristor based on hyperbolic function is derived. The universal memristor model proposed in this article enriches the research of constructing memristor components with existing components and provides a reference for future research on mem-element emulators.
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Please write an abstract with title: Online discussions in computer science courses: how to make them an effective learning tool, and key words: Computer science, Computer science education, Potential well, Warehousing, Foot, Collaborative work, Videoconference, Decision making, Educational programs, Job shop scheduling. Abstract: This paper discusses the experience of using asynchronous online discussions obtained by a group of faculty teaching graduate computer science courses online. We also discuss a number of advantages of using asynchronous discussions and how they can enrich the learning experience of students. This is followed by a collection of our practices in course management when online discussions are used. The paper is concluded by a case study describing how online discussions were used in a data warehousing course offered to graduate students online.
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Please write an abstract with title: Assessing dependability of wireless networks using neural networks, and key words: Wireless networks, Neural networks, Availability, Maintenance, Artificial neural networks, Computer network reliability, Arm, Analytical models, Computer simulation, Artificial intelligence. Abstract: Critical infrastructures such as wireless network systems demand dependability. Dependability attributes addressed in this paper include availability, reliability, maintainability and survivability. This research uses computer simulation and artificial intelligence to introduce a new approach to assess dependability of wireless networks. The new approach is based on the development of a neural network, which is trained to investigate availability, reliability, maintainability, and survivability attributes (ARMS) of a wireless network. In this work, given a variety of reliability and maintainability attribute scenarios for a wireless infrastructure, the resulting impact on network availability and survivability are determined. Component mean time to failure (MTTF) is used to model reliability, while the mean time to restore (MTR) is used for maintainability. Here, unavailability, the complement of availability, is defined as the fraction of time the entire network system is down, while survivability is the fraction of network user capacity up over time. Both availability and survivability can be instantaneous or averaged over some period. The data set, which is used to train the neural network, is obtained from simulation experiments with a range of component MTTF and MTTR. In addition, the number of times a new regulatory outage reporting threshold is surpassed is also determined. This research also focuses on the relative performance of neural network modeling compared to analytical and simulation techniques for assessing the ARMS attributes of a wireless network, and the additional insights that can be obtained from NN modeling.
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Please write an abstract with title: An attendance system design based on RFID technology, and key words: Radio frequency, Databases, Maintenance engineering, Stability analysis, Robustness, Liquid crystal displays, Social implications of technology. Abstract: This paper presented a design scheme of attendance system based on RFID technology. The system used Arduino, MRFC522 and WIFI to design the network card reader. The system stored data through Access database, and designed the upper computer program by the LabVIEW 2016. The system realized the record, query and background management of staff attendance data. Through the attendance system, the enterprise can timely understand the attendance of employees, facilitate the management and assessment of employees. The system had the advantages of low cost, simple operation, simple interface and easy maintenance.
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Please write an abstract with title: Evaluating an embedded software reference architecture - industrial experience report, and key words: Embedded software, Computer architecture, Computer industry, Engines, Software architecture, Software maintenance, Pulp manufacturing, Programming, Software systems, Protection. Abstract: In this paper, we discuss experiences gained during evaluation of the maintainability of a reference architecture in use at Oce, one of the world's leading copier manufacturers. The evaluation is conducted using an approach based on SEI's software architecture analysis method (SAAM). The paper proposes a variant of SAAM that helps to reduce the organisational impact of architecture evaluations. Second, we analyse the implications of evaluating reference architectures as opposed to single-product architectures. Furthermore, we share our experience of conducting the evaluation, draw lessons for practitioners, and propose new research topics.
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Please write an abstract with title: Investigation into Physical and Pathophysiological Changes of Hemodynamics on Segmented Patient-Specific Cerebral Aneurysm Models through Computational Analysis, and key words: Geometry, Image segmentation, Computational modeling, Simulation, Aneurysm, Hemodynamics, Image reconstruction. Abstract: Growth and rupture of human cerebral aneurysm are risky as both of these stages may lead to human organ dysfunction arisen from neurological disorders. The rupture of cerebral aneurysm can even lead to fatal hemorrhaging and other serious health issues. Several sets of medical images from patients have been utilized to reconstruct patient-specific cerebral aneurysm model geometries with different threshold value through image segmentation for computational analysis. In this paper, the physical and pathophysiological changes on hemodynamics, namely geometry volume, inlet area, outlet area, wall shear stress (WSS) distribution, and velocity flow field in the particular models are discussed. A prediction on the location where the aneurysm grows and ruptures has been made. Besides, the model geometries have been validated with varied mesh size. The simulation results show that the mesh size which is applied on the model geometry has significant effect on the generated WSS and velocity values, when varying within certain range. From the findings, the mesh size is one of the important elements which should be optimized, other than the threshold value used for model geometry reconstruction.
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Please write an abstract with title: Acquisition of FDS for Oil-Immersed Insulation at Transformer Hotspot Region Based on Multiconstraint NSGA Model, and key words: Insulation, Aging, Power transformer insulation, Oil insulation, Oils, Dielectrics, Data models. Abstract: The evaluation of the state of transformer oil-immersed insulation based on the traditional methods becomes unreliable due to the nonuniform aging effect. To address this issue, a novel model for accessing the aging information of transformer oil-immersed insulation at the hotspot is proposed. In this article, frequency-domain spectroscopy (FDS) is selected as the carrier for characterizing the aging states of oil-immersed insulation. The multiobjective function for reversing the FDS of the hotspot is constructed based on the dielectric response equivalent circuit. Then, the nondominated sorting genetic algorithm with the multiconstraint scheme is proposed to solve the multiobjective function, by which the FDS data of the transformer hotspot region are acquired. The verification results indicate that the average standard deviation between the computed FDS of the hotspot region and the measured data is less than 0.26. The contribution of this article is in the exploration of the proposed model as a potential tool to extract the FDS data of the hotspot region. This will promote a more reliable aging evaluation of the transformer oil-immersed paper insulation at the hotspot.
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Please write an abstract with title: A Multi-Stage Progressive Learning Strategy for Covid-19 Diagnosis Using Chest Computed Tomography with Imbalanced Data, and key words: COVID-19, Sensitivity, Three-dimensional displays, Computed tomography, Pulmonary diseases, Lung, Signal processing. Abstract: In this paper, a multi-stage progressive learning strategy is investigated to train classifiers for COVID-19 Diagnosis using imbalanced Chest Computed Tomography Data acquired from patients infected with COVID-19 Pneumonia, Community Acquired Pneumonia (CAP) and from normal healthy subjects. In the first learning stage, pre-processed volumetric CT data together with the segmented lung masks are fed into a 3D ResNet module, and an initial classification result can be obtained. However, due to categorical data imbalance, we observe large differences in sensitivity between COVID-19 and CAP cases. In the second stage, five learning models are independently trained over data with only COVID-19 and CAP cases, and are then ensembled to further discriminate the two classes. The final classification results are obtained by combining the predictions from both stages. Based on the validation dataset, we have evaluated our method and compared it with up-to-date methods in terms of overall accuracy and sensitivity for each class. The validation results validate the accuracy of the proposed multi-stage learning strategy. The overall accuracy of the validation dataset is 88.8%, and the sensitivities are 0.873, 0.789 and 1 for COVID-19, CAP and normal cases, respectively.
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Please write an abstract with title: Simulate Forest Trees by Integrating L-System and 3D CAD Files, and key words: Solid modeling, Vegetation, Three-dimensional displays, Computational modeling, Forestry, Visualization, Geometry. Abstract: In this article, we propose a new approach for simu-lating trees, including their branches, sub-branches, and leaves. This approach combines the theory of biological development, mathematical models, and computer graphics, producing simu-lated trees and forest with full geometry. Specifically, we adopt the Lindenmayer process to simulate the branching pattern of trees and modify the available measurements and dimensions of 3D CAD developed object files to create natural looking sub-branches and leaves. Randomization has been added to the placement of all branches, sub branches and leaves. To simulate a forest, we adopt Inhomogeneous Poisson process to generate random locations of trees. Our approach can be used to create complex structured 3D virtual environment for the purpose of testing new sensors and training robotic algorithms. We look forward to applying this approach to test biosonar sensors that mimick bats' fly in the simulated environment.
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Please write an abstract with title: Incorporating Temporal Information for Ventricular Contour Detection in Echocardiographic Image Sequences, and key words: Image sequences, Level set, Heart, Echocardiography, Image segmentation, Degradation, Ultrasonic imaging, Image edge detection, Active contours, Counting circuits. Abstract: A novel way to incorporate temporal information with level set algorithm is proposed to counter the dropout problem when detecting ventricular contours in echocardiographic raphic image sequences. The temporal information ided embed- ed into the speed term of the level set equation. By identifying the ventricular contours as strong or weak segments, the weak segments are strengthened based on temporal information from neighboring frames. Hence disrupted heart wall boundary structure information due to dropout can be recovered. A Gaussian Mixture Model (GMM) is employed to compute thresholds separating the segments. A weight and a strengthening ng factor are used to control the information recovery process. Experimental results show the proposed method exhibits good performance when tracking the ventricular boundary in real echocardiographic data.
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Please write an abstract with title: Lightnings over rose bouquets: an analysis of the topology of the Bitcoin Lightning Network, and key words: Network topology, Scalability, Conferences, Lightning, Bitcoin, Routing, Software. Abstract: The Lightning Network is a P2P overlay that allows two Bitcoin users to create a new payment channel with a transaction, and later exchange cryptocurrency on that channel independently from the Bitcoin blockchain, improving Bitcoin’s scalability issues and making it more suitable for frequent micropayments. Moreover, the channels can also be used to route payments between two users who do not share a direct channel themselves.In this paper we study the topology of the Lightning Network in a given time period, performing a number of analysis on the channels and on the nodes composing the network. We study the churn rate, we evaluate centrality measurements and the clustering coefficient to evaluate the network connectivity, and finally we analyze the presence of a pattern that we named "bouquet". The importance of this pattern is proven by the finding that, removing specific nodes of the "bouquets" (1% of the total) causes the disconnection from the largest component of about 41% nodes.
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Please write an abstract with title: Joint channel & polarization assignment for capacity enhancement in non line-of-sight fixed wireless networks, and key words: Polarization, Intelligent networks, Wireless networks, Radiofrequency interference, Frequency, Independent component analysis, Electronic mail, Base stations, Receiving antennas, Directional antennas. Abstract: We consider frequency channel assignment (CA) and antenna polarization assignment (PA) schemes jointly in the scope of non line-of-sight fixed wireless networks. First, we introduce a new, more accurate method to characterize CA and PA schemes. Following this approach, we propose a new rotated-interleaved CA scheme that outperforms existing CA schemes and a new interleaved-interleaved PA methodology that is more efficient than basic strip-by-strip PA when applied on top of most CA schemes for re-use factor F/sub R/ = 1. An investigation on the total capacity gains of the CA and PA schemes showed that each CA scheme performs differently when combined with different PA schemes and for different re-use factors and only a joint consideration can highlight the best CA-PA combination. In a further step, instead of simply combining CA, PA schemes, we introduce a methodology to design new PA patterns that are optimized (oPA) on the distinct features of each CA scheme. Our results demonstrate that the oPA strategy achieves higher performance than other PA methodologies for F/sub R/ = 1, 2.
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3,257
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Please write an abstract with title: Market-driven sizing and siting of generation investment, and key words: Renewable energy sources, Costs, Profitability, Production, Network analyzers, Generators, Power markets. Abstract: The analysis of new electricity generation initiatives in power systems within unbundling framework should account for the competitiveness of marginal cost in energy market dispatch and for the location of proper plant sizes. In this paper, a method for the generation investment analysis is proposed, involving market-based power production levels over yearly horizon with hourly time steps. Furthermore load flow analysis is carried out in order to assess most suitable connection bus. An investment profitability is therefore evaluated. The method is applied to the case of Sicily, accounting for discrete sizes and production cost for candidate technology.
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Please write an abstract with title: Parameter Optimization to Power Oscillation Damper (POD) Considering its Impact on the DFIG, and key words: Doubly fed induction generators, Oscillators, Power system stability, Transfer functions, Stability analysis, Rotors, Damping. Abstract: The power oscillation damper (POD) in the doubly-fed induction generator (DFIG) is to damp the low- frequency oscillation (LFO) in the power systems. But the POD will introduce the LFO to the DFIG and intensify the oscillation of the latter. In this paper, open-loop subsystems of the DFIG with the POD and the rest part of power system are derived to describe the interaction between them. The balanced truncation method is used to reduce the transfer function of the DFIG and derive the analytical description to the oscillation of the DFIG. Considering the impact of the POD on the DFIG, the constraint to the DFIG is newly incorporated in the optimization model to the POD parameters, with the aim to alleviate the oscillation of both the DFIG and power system. The simulation verifies the accuracy of the reduced model of the DFIG, and validates the effectiveness of the improved optimization to the POD of the DFIG.
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Please write an abstract with title: Modern coding algorithms of video and audio information, and key words: Modems, Image coding, Transform coding, Video compression, Arithmetic, Vehicle dynamics, Signal processing, Decoding, Discrete cosine transforms, Brightness. Abstract: This work present the results of simulation of a procedure of compression of a piece of a media-signal are shown. The features of application of algorithms of Haffmann, LZW and arithmetic are reviewed and routined on an example of a faxgram efficiency of the indicated methods.
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Please write an abstract with title: Eddy Current Damping Suppression of Long Primary Linear Synchronous Motor, and key words: Damping, Fluctuations, Three-dimensional displays, Magnetomechanical effects, Industry applications, Synchronous motors, Permanent magnet motors. Abstract: This paper concerns the analysis and suppression method of eddy current induced in the water-cooled plate. Eddy current is generated by time-varying current in the armature and the back EMF caused by moving magnets in the water-cooled plate. It produces a damping force, which influences the motor's dynamic characteristic. In this paper, a new method is introduced to suppress eddy current by current vector synthesis. The new structure has been analyzed using 3D FEM and the results show that the new method has a good effect of suppressing eddy currents.
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Please write an abstract with title: Analysis of Methods for Calculating Parameters of the Equivalent Circuit of a Squirrel Cage Induction Motor, and key words: Induction motors, Integral equations, Rotors, Estimation, Electromagnetics, Complex systems, Equivalent circuits. Abstract: Induction motor is a complex system, characterized by electrical, electromagnetic, mechanical and thermal processes. For an exact mathematical description of them it's requires solving a large systems of integral equations, which in some number of cases is not worth it. Today we know quite a lot of simplified techniques, which allowing us to make calculations with various of assumption, the latter in turn will lead to errors in values. In this article analyzes existing methods for calculating parameters of the replacement circuit of a three-phase squirrel cage induction motor. For selecting most precise method, the calculating of parameters of the real motor 4AA50 series was done and they were compared to catalog data. Estimation of errors introducing by various methods also was made. In result of research it was established that methods of Pantel O.V., Makeev M.C., Kuvshinov A.A., Moshinskiy Yu.A., Bespalov V.Ya., Kiryakin A.A., Gridin V.M., German-Galkin S.G. and Kardonov G.A. have the greatest error, so for calculating parameters of the replacement circuit of low-power induction motor it's more efficient to use methods by Usoltsev A.A.
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Please write an abstract with title: A Novel and Unified Full-Chip CMP Model Aware Dummy Fill Insertion Framework With SQP-Based Optimization Method, and key words: Layout, Optimization, Integrated circuit modeling, Microsoft Windows, Surface topography, Semiconductor device modeling. Abstract: Dummy filling is widely applied to significantly improve the planarity of topographic patterns for the chemical mechanical polishing process in VLSI manufactures. The main challenge of dummy filling is balancing multiple objectives, such as fill amounts, planarity, parasitic capacitance, etc. An obvious drawback of traditional rule-based dummy filling methods is pattern densities, instead of post-chemical mechanical polishing (CMP) topographies, being included in optimization objectives. Although the quality of post-CMP topography strongly depends on pattern features of layouts, especially the density uniformity, however, experimental results show that chip surface variations are not exactly the same as density variations. In this article, a unified dummy fill insertion optimization framework is proposed, integrated with the multiple starting points-sequential quadratic programming (MSP-SQP) optimization solver, where all objectives are considered without approximation. Inside this framework, a full-chip CMP simulator is first integrated to evaluate the planarity of the chip surface. By selecting the initial points smartly with heuristic prior knowledge, the proposed method can be effectively accelerated. The effectiveness of the proposed algorithm is verified with the average 25.8% improvement of quality compared with rule-based methods.
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Please write an abstract with title: A heating data management system based on B/S mode, and key words: Heating systems, Heat engines, Databases, Data compression. Abstract: There are more and more applications in the industrial market with the continuous development of network technology in recent years. In this paper we use the database technology and network technology to design a heating data management system based on B/S mode. This system enables the staff view the real-time data of each heating station through the network anytime and anywhere. This system consists of three parts: client, database and server. We use Visual Studio 2010 to develop this project which uses asp.net framework and ado.net technology to access the database.
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Please write an abstract with title: Energy-Efficient Barrier Lifetime Prolonging Scheme Based on Repairing in Directional Sensor Networks, and key words: Sensors, Maintenance engineering, Wireless sensor networks, Fans, Energy consumption, Batteries, Mobile nodes. Abstract: As the sensor nodes have quite limited battery capacity and their energies are not renewable, the barrier hole appears once one node in the barrier runs out of its energy. Barrier hole repairing is necessary to effectively extend the lifetime of barrier coverage in directional sensor networks (DSNs). This article studies the design of effective barrier-hole-repairing scheme for DSNs. Specifically, it first presents the important concept of the repairing region (RepR), inside which the mobile nodes located can repair the hole only by rotating their sensing directions. Then it analyzes the movement and rotation energy consumption of different types of candidate repairing nodes which are not in the barrier. Finally, based on the above analysis, it proposes an effective scheme to schedule an optimal node to repair the barrier hole with the minimum energy consumption, fully exploiting residual resources (unused nodes and power) to increase network service time. Simulation results show that, compared to other barrier-hole-repairing schemes, our scheme could greatly prolong the lifetime of barrier coverage.
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Please write an abstract with title: Deep Learning Based Identification Method for Signal-Level Wireless Protocol, and key words: Protocols, Feature extraction, Wireless communication, Deep learning, Convolutional neural networks, Behavioral sciences, Convolutional neural networks, Neural networks. Abstract: Electromagnetic spectrum surveillance is the basis of space environment monitoring and management, while protocol identification is one of the most important methods. Protocol identification has been applied in many fields, such as target recognition, anomaly detection, security management and information countermeasure. In the past decade, a lot of deep learning based protocol identification methods have been proposed, based on the data-level protocol. However, the data needs to be demodulated and decoded, depending on the prior information of the target system. In this paper, we focus on signal-level protocol, and introduce the deep learning based identification method. We first develop a multi-dimensional convolutional neural network based method for feature extraction of signal-level protocol. Then, a spatial pooling convolutional neural network is introduced for variable length protocol identification. At last, an unsupervised training network is proposed for feature extraction of unlabelled signal-level protocol. The proposed methods are evaluated by using the practical wireless protocols, and the effectiveness is verified by simulation results.
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Please write an abstract with title: The Hand Prehensile Movement Modified by Visual Illusion in Immersive Virtual Reality, and key words: Visualization, Virtual reality, Apertures, Stroke (medical condition), Life sciences, Steady-state, Analysis of variance. Abstract: This paper investigates prehensile movement (PM) characteristics of non-dominant hand (NDH) with visual illusion (VI) in immersive virtual reality (VR) with haptic feedback. A VR program with compensation for subtle finger motions (FM) of a hemiplegic hand was developed. There are two controlling factors of VI: visibility of virtual hand and virtual object- visual factor (VF), and metacarpophalangeal joint angle (MCP) gain- gain factor (GF). This research consists of two experiments: proprioception experiment with everyday life objects and VF, and PM characteristics experiment with VI. As a statistical result, 2-way analysis of variance (ANOVA) test revealed that object size affects significantly towards steady-state pinch grip aperture (SGA). As for the second experiment, peak grip aperture (PGA), SGA error (SGAE) and steady-state pinch grip aperture time (SGAT) were influenced by VI. From this study, we concluded that VI impacts PM for healthy subjects, and further research is possible toward hemiplegic stroke patients (HSP).
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Please write an abstract with title: New linearization method for the modulated signals with high peak-to-average ratio: peak-to-average ratio reduction and expansion, and key words: Peak to average power ratio, High power amplifiers, Operational amplifiers, Multiaccess communication, Circuits, Power amplifiers, Power system restoration, Signal restoration, Statistics, Linearity. Abstract: A new linearization method for the high power amplifier modulated by a high peak-to-average ratio signal is proposed. The amplifier consists of a high power amplifier with a predistorter, a peak power limiter, and cancellation loops similar to the feedforward amplifier. The linearization performance is enhanced by reducing the peak input power to the amplifier using a rate limiter and the distortion from the limited signal is restored at the cancellation sub-path. Simulation and experimental results for the amplifier module with WCDMA signal show a significant improvement of ACLR.
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Please write an abstract with title: Effect of Surface Degradation of Actuator on Electromagnetic Pulse Welding, and key words: Degradation, Industries, Actuators, Surface discharges, Welding, EMP radiation effects, Electron tubes. Abstract: One of the high speed welding process among all the present welding techniques is Electromagnetic pulse welding (EMPW). Electromagnetic force from discharged current through Actuator responsible to develop a repulsive force between the induced current flowing parallel and in opposite direction. For successful weldment using this process the design of actuator is the most important factor due to high magnetic field on surface of work piece. In case of high quality welding factors such as impact velocity, impact angle standoff distance, flyer thickness and overlap length have to be chosen carefully. Still the surface of actuators plays vital role over all those above mentioned factors. EMPW has wide applications in nuclear industry, automotive industry, aerospace, electrical industries. However major issues such as formability and weldability still remain due to surface degradation. Surface degradation affects the magnetic field on surface of work piece. Due to ease in controlling the magnetic field enveloped inside tubes, the EMPW has been widely used for tube welding. In case of flat components control of magnetic field is difficult. Hence the application of EMPW gets restricted. But both tube and flat welding methods face same actuator surface degradation. The present work attempts to make a novel contribution by investigating the root cause of surface degradation and its elimination to improve welding quality in EMPW. The work emphasizes the approaches and engineering calculations required to effectively use of actuator in EMPW.
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Please write an abstract with title: Progressive-Granularity Retrieval Via Hierarchical Feature Alignment for Person Re-Identification, and key words: Measurement, Training, Conferences, Aggregates, Signal processing, Feature extraction, Cameras. Abstract: Person re-identification (re-ID) aims to match pedestrian images from non-overlapping cameras. It is a challenging task because of the feature misalignment problem caused by occlusion. In this paper, inspired by the coarse-to-fine nature of human perception, we propose a novel Progressive-Granularity Retrieval (PGR) method to tackle this issue. Specifically, (i) we define instance-level, part-level and pixel-level features for an image. PGR learns these features by a single feature extractor to capture hierarchical clues in the image. (ii) These features are inherently related but different in perceptual granularity, and they can provide complementary information. For each type of feature, we propose a corresponding similarity metric to achieve hierarchical feature alignment. (iii) In training, we learn the model end-to-end. In inference, a progressive retrieval strategy is introduced to efficiently aggregate the complementary information provided by these features. Extensive experiments on three bench-marks of both occluded and holistic-body re-ID tasks show the effectiveness of the proposed method. Especially, our method significantly outperforms state-of-the-art by 4.5% Rank-1 score on the challenging Occluded-Duke dataset.
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Please write an abstract with title: Decision Tree Ensembles Applied to Benchmark Data Set for Three-Phase Coriolis Mass Flow Metering, and key words: Coriolis Mass Flow Metering, Random Forest, Gradient Boosting, Extra Randomized Trees, three-phase flow. Abstract: This paper considers the problem of correcting Coriolis meter mass flow and density errors induced by the effects of three-phase (oil/water/gas) flow. Previously, neural networks and support vector machines have been used. Here, for the first time, algorithms based on ensembles of decision trees are used: Random Forest, Gradient Boosting, and Extra Randomized Trees. The process of finding the optimal parameters for each model is described. Gradient Boosting shows the best results, giving the mean absolute errors for mass flow and density of 1.07% and 0.69% respectively. The results demonstrate the potential for using Decision Trees Ensembles in Coriolis mass flow metering multiphase correction.
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Please write an abstract with title: Faster-LIO: Lightweight Tightly Coupled Lidar-Inertial Odometry Using Parallel Sparse Incremental Voxels, and key words: Laser radar, Point cloud compression, Data structures, Spinning, Simultaneous localization and mapping, Spatial databases, Graphics processing units. Abstract: This letter presents an incremental voxel-based lidar-inertial odometry (LIO) method for fast-tracking spinning and solid-state lidar scans. To achieve the high tracking speed, we neither use complicated tree-based structures to divide the spatial point cloud nor the strict k nearest neighbor (k-NN) queries to compute the point matching. Instead, we use the incremental voxels (iVox) as our point cloud spatial data structure, which is modified from the traditional voxels and supports incremental insertion and parallel approximated k-NN queries. We propose the linear iVox and PHC (Pseudo Hilbert Curve) iVox as two alternative underlying structures in our algorithm. The experiments show that the speed of iVox reaches 1000–2000 Hz per scan in solid-state lidars and over 200 Hz for 32 lines spinning lidars only with a modern CPU while still preserving the same level of accuracy.
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Please write an abstract with title: Rank Minimization-Based Toeplitz Reconstruction for DoA Estimation Using Coprime Array, and key words: Estimation, Sensor arrays, Covariance matrices, Direction-of-arrival estimation, Sensors, Minimization, Optimization. Abstract: In this letter, we address the problem of direction finding using coprime array, which is one of the most preferred sparse array configurations. Motivated by the fact that non-uniform element spacing hinders full utilization of the underlying information in the receive signals, we propose a direction-of-arrival (DoA) estimation algorithm based on low-rank reconstruction of the Toeplitz covariance matrix. The atomic-norm representation of the measurements from the interpolated virtual array is considered, and the equivalent dual-variable rank minimization problem is formulated and solved using a cyclic optimization approach. The recovered covariance matrix enables the application of conventional subspace-based spectral estimation algorithms, such as MUSIC, to achieve enhanced DoA estimation performance. The estimation performance of the proposed approach, in terms of the degrees-of-freedom and spatial resolution, is examined. We also show the superiority of the proposed method over the competitive approaches in the root-mean-square error sense.
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3,273
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Please write an abstract with title: Collaboration in Participant-Centric Federated Learning: A Game-Theoretical Perspective, and key words: Training, Computational modeling, Costs, Collaboration, Data models, Games, Collaborative work. Abstract: Federated learning (FL) is a promising distributed framework for collaborative artificial intelligence model training while protecting user privacy. A bootstrapping component that has attracted significant research attention is the design of incentive mechanism to stimulate user collaboration in FL. The majority of works adopt a broker-centric approach to help the central operator to attract participants and further obtain a well-trained model. Few works consider forging participant-centric collaboration among participants to pursue an FL model for their common interests, which induces dramatic differences in incentive mechanism design from the broker-centric FL. To coordinate the selfish and heterogeneous participants, we propose a novel analytic framework for incentivizing effective and efficient collaborations for participant-centric FL. Specifically, we respectively propose two novel game models for contribution-oblivious FL (COFL) and contribution-aware FL (CAFL), where the latter one implements a minimum contribution threshold mechanism. We further analyze the uniqueness and existence for Nash equilibrium of both COFL and CAFL games and design efficient algorithms to achieve equilibrium solutions. Extensive performance evaluations show that there exists free-riding phenomenon in COFL, which can be greatly alleviated through the adoption of CAFL model with the optimized minimum threshold.
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3,274
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Please write an abstract with title: Synchronous wavelength reusing/sharing protocols for non-regenerative dual bus optical networks, and key words: Optical fiber networks, Access protocols, Optical receivers, Wavelength division multiplexing, Throughput, Erbium-doped fiber amplifier, Optical transmitters, Telecommunication traffic, Traffic control, Stimulated emission. Abstract: The dual-bus optical network with non-regenerative stations has become popular. In general, the non-regenerative implementation is better than the generative implementation. In this paper, two protocols are proposed to improve the performance of this network. These two protocols are "synchronous wavelength sharing protocol (SWSP)" and "synchronous wavelength reusing/sharing protocol (SWRP)". The simulation results show that the network throughput is better than those of SWSP in the situation of a limited number of wavelengths, tunable receivers and heavy traffic loading.
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3,275
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Please write an abstract with title: The PLR Recovery for GMR/TMR Devices Using Internal Thermal Heat and External Magnetizing, and key words: Temperature sensors, Electrical engineering, Magnetization, Magnetic domains, Materials reliability, Magnetic heads, Magnetic materials. Abstract: A pinned layer reversal failure in GMR or TMR devices could be recovered using internal thermal energy and external magnetization. The thermal energy from the dynamic flying height control heater activates the exchange layer to an unstable state. Its magnetic domain could be oriented freely. Then, the external magnetic field realigns the magnetic domain of the exchange layer to the right orientation that provides the proper magnetization of the pinned layer. This recovery is helpful to correct the head defect and enhances its reliability.
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3,276
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Please write an abstract with title: Supporting Coursework in an Online Gaming Environment, and key words: Games, Online Communities/Technical Collaboration, Toy industry, Virtual environment, Computer science, Educational institutions, Computer industry, Personnel, Engineering profession, Information technology. Abstract: As video games are growing in popularity among a wider audience, new challenges and opportunities are arising for game-oriented research. For example, one characteristic of many modern games is an infrastructure for collaboration - game environments often involve multiple players who either compete or collaborate to accomplish individual or shared objectives. Support for collaboration makes certain game activities possible, but also has initiated a number of virtual communities, i.e. the players who regularly plan ahead to meet within a gaming environment (such as the large groups of Everquest players or the new and extremely popular Warcraft game). Our research begins with the premise that online communities of this sort might have other benefits, such as supporting collaboration and community in other online activities. Currently, we are initiating a project that will explore the relationship of identity establishment in online gaming environments with students' willingness and desire to participate in other online activities (e.g. group projects)
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Please write an abstract with title: A game theoretic framework for incentives in P2P systems, and key words: Game theory, Peer to peer computing, Distributed computing, Economic forecasting, Intelligent networks, Computer science, Availability, Incentive schemes, Centralized control, Control systems. Abstract: Peer-to-peer (P2P) networks are self-organizing, distributed systems, with no centralized authority or infrastructure. Because of the voluntary participation, the availability of resources in a P2P system can be highly variable and unpredictable. We use ideas from game theory to study the interaction of strategic and rational peers, and propose a differential service-based incentive scheme to improve the system's performance.
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3,278
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Please write an abstract with title: H-Diffu: Hyperbolic Representations for Information Diffusion Prediction, and key words: Integrated circuit modeling, Social networking (online), Predictive models, Task analysis, Diffusion processes, Recurrent neural networks, Logic gates. Abstract: With the proliferation of online social networks, a great deal of online user action data has been generated. Such data has enabled the study of information diffusion prediction, which is a fundamental problem for understanding the propagation of information on social media platforms. In diffusion prediction models, there are two standard components, i.e., a social graph and information diffusion cascades. We observe that both components exhibit latent hierarchical structures. However, most existing models are designed based on euclidean spaces, and hence cannot effectively capture complex patterns, especially hierarchical structures. Therefore, we investigate a novel research problem to learn hyperbolic representations for information diffusion prediction. To reflect the different characteristics of social graphs and diffusion cascades, we encode them into two latent hyperbolic spaces with different trainable curvatures. In addition, to model influence dependencies, we propose a co-attention mechanism to capture the processes of diffusion cascades using positional embeddings. Given a set of activated seed users, we jointly exploit diffusion cascades and social links to predict which users will be influenced. We conduct extensive experiments on four real-world datasets. Empirical results demonstrate that the proposed H-Diffu model significantly outperforms several state-of-the-art diffusion prediction frameworks.
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3,279
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Please write an abstract with title: Review of the thin film resonator technology, and key words: Resonator filters, Piezoelectric films, Substrates, Frequency, Bandwidth, Biomembranes, Composite materials, Transistors, Impedance, Microelectronics. Abstract: The thin film resonator technology has been under the development for over forty years in one form or another. Although the basic approach is derived from the desire to reach higher frequencies than those readily achieved by thinning bulk crystals, there have always been competing technologies for fundamental material or processing problems that have impeded the development. Finally, a point was reached in the wireless market wherein competing technologies appeared unable to meet the demands of modern wireless applications and thin film approaches began to receive some emphasis. This paper is a review of the thin film resonator technology.
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3,280
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Please write an abstract with title: Magnetic field analysis of HTS transformer windings with high currents, and key words: Magnetic fields, Magnetic analysis, High temperature superconductors, Windings, Transformer cores, Coils, Geometry, Magnetic cores, Critical current, Anisotropic magnetoresistance. Abstract: The leakage magnetic field in HTS transformer windings fabricated by Bi-2223 tapes decreases the critical current and increases the ac losses in the tapes. Because of the anisotropy of the HTS tape, the numerical analysis of the radial component of the leakage field is especially important. In this paper the influence of the core structure and the winding configuration on the stray field is studied by finite element method, and some suggestions for improving the leakage field distribution are presented to make HTS transformers more efficient.
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3,281
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Please write an abstract with title: Femtosecond soliton spatio-temporal properties in multimode GRIN fibers, and key words: Couplings, Chromatic dispersion, Europe, Solitons, Optical fiber communication, Ultrafast optics, Optical fiber dispersion. Abstract: Femtosecond multimode solitons composed by non-degenerate modes have unique properties: their pulsewidth and energy only depend on linear dispersive properties, and coupling conditions. They are unstable objects which evolve into stable singlemode pulses.
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3,282
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Please write an abstract with title: Recent advances in high-density and large-scale AWG multi/demultiplexers with higher index-contrast silica-based PLCs, and key words: Large-scale systems, Programmable control, WDM networks, Optical filters, Optical fiber networks, Wavelength division multiplexing, Thin film circuits, Interference, Microoptics, Optical losses. Abstract: This paper reviews recent progress on high-density and large-scale arrayed-waveguide-grating (AWG) multi/demultiplexers, which have been developed for wavelength division multiplexing (WDM)-based photonic networks. The AWG has been the key to the construction of flexible and large-capacity WDM networks. This is because, compared with conventional filters consisting of thin-film interference filters and microoptics, the AWG offers the advantages of low loss, high port counts, and mass productivity. To improve such characteristics further, low-loss, higher index-contrast (super-high /spl Delta/) planar lightwave circuits (PLCs) with a bending radius of 2 mm have recently been developed. It has been shown that these PLCs are effective for use in constructing a compact AWG module with 1/5 the volume of a conventional module and large-scale AWGs with 256 and 400 channels. Three techniques for low-loss fiber connection with spot-size converters have also been developed for the super-high /spl Delta/ PLCs, and it has been confirmed that these techniques can be applied to the fabrication of AWG modules. Furthermore, two-stage tandem AWG-type multi/demultiplexers with more than 1000 channels have been demonstrated. This paper describes the progress that has been made on these high-density and large-scale AWGs, which are expected to contribute greatly to the construction of future photonic networks including optical add/drop multiplexing systems and optical crossconnect systems.
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3,283
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Please write an abstract with title: Internet of Things Traffic Consumption Control System, and key words: Time-frequency analysis, Protocols, Information resources, Control systems, Malware, Telecommunications, Internet of Things. Abstract: The problem of controlling the consumption of traffic by devices of the Internet of things to prevent threats associated with attacks on devices with the aim of stealing information resources is considered. To control the traffic consumption, an application integrated into the Internet of things device is proposed. The application is an information system with the functions of accounting for traffic consumption, control of consumed resources and forecasting of traffic volumes and consumed resources. The system analyzes several characteristics of traffic received from an IoT device, such as the frequency of packets transmitted over a certain type of protocol, the number of traffic packets for a set time, and others. The traffic characteristics are tested against statistical criteria. Deviations will indicate to the user anomalous occurrences. Thus, the user will be warned about possible attacks on the device and theft of information resources.
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3,284
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Please write an abstract with title: Adaptive Frequency-Domain Normalized Implementations of Widely-Linear Complex-Valued Filter, and key words: Frequency-domain analysis, Signal processing algorithms, Adaptive filters, Convergence, Filtering algorithms, Adaptation models, Information filters. Abstract: The widely-linear complex-valued least-mean-square (WL-CLMS) algorithm exhibits slow convergence in the presence of non-circular and highly correlated filter input signals. To tackle such an issue with reduced computational complexity, this paper introduces adaptive frequency-domain normalized implementations of widely-linear complex-valued filter. Two normalized algorithms are firstly devised based on the circulant matrices of weight coefficients and the regression vector, respectively. In the design, the normalization matrix using the second-order complementary statistical information of the input signal helps increase the algorithm convergence speed. Then, mean-square and complementary mean-square performance of periodic update frequency-domain widely-linear normalized LMS (P-FDWL-NLMS) algorithm for non-circular complex signals is analyzed. In addition, by introducing a variable-periodic (VP) mechanism, we propose the VP-FDWL-NLMS method that provides faster convergence than the P-FDWL-NLMS scheme. Computer simulation results show the superiority of the proposed approach over the fullband widely-linear complex-valued least-mean-square, augmented affine projection algorithm and its variable step-size version, in terms of both complexity and convergence rate.
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3,285
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Please write an abstract with title: Random Fourier Features based Post-Distortion for Massive-MIMO Visible Light Communication, and key words: Dictionaries, Bit error rate, Signal processing algorithms, Light emitting diodes, Kernel, Optimization, Visible light communication. Abstract: Massive multiple input multiple output (m-MIMO) visible light communication (VLC) has emerged as a viable technology to enhance the throughput of an existing VLC based systems in order to serve the high speed data requirement for beyond 5G and 6G communication systems. However, performance of m-MIMO VLC is severely impaired by (1) columns of m-MIMO VLC channel are highly correlated which makes the channel matrix ill-conditioned, and (2) nonlinear transfer-characteristics of light emitting diode (LED). The aforementioned channel impairments collectively degrade the overall bit error rate (BER) at the receiver. In this paper, finite memory budget adaptive precoder is proposed to decrease the channel correlation/condition number of MIMO channel matrix. Reproducing kernel Hilbert space (RKHS) based post-distorters have been proposed in the literature for VLC which rely on growing dictionary of kernel evaluations, and hence it is difficult to practically implement them under finite memory budget. In this paper, random Fourier features (RFF) based kernel least mean square (RFF - KLMS) algorithm is proposed for post-distortion over m-MIMO VLC channels which alleviates the requirement of dictionary and facilitates post-distortion under finite memory budget. Computer simulations performed over m-MIMO VLC channels show that the proposed RFF based algorithm exhibit similar BER performance with reduced computational complexity as compared to the dictionary based post-distortion algorithm.
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3,286
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Please write an abstract with title: Design and Simulation of An Energy Recovery Circuit for Repetitive Inductive Pulsed Power Supply, and key words: Capacitors, Turning, Power supplies, Integrated circuit modeling, Load modeling, Inductors, Equivalent circuits. Abstract: The use of high-temperature superconducting pulsed power transformers (HTSPPT) for repetitive pulsed power supplies has been demonstrated. However, this type of inductive pulsed power supply (IPPS) has a problem that cannot be ignored, that is, it has more residual energy that is difficult to recover when facing inductive loads. In this paper, a residual energy recovery circuit unit is designed for this type of repetitive IPPS for inductive loads. With this circuit unit, the residual energy of the secondary inductors can be recovered and reused for the next discharging phase. To illustrate this circuit, simulations were carried out. The results show that the circuit can reduce the falling time of the load current pulse in the case of inductive load.
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3,287
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Please write an abstract with title: DNA-like Materials Could Open New Computing Frontiers, and key words: Optical fiber amplifiers, Stimulated emission, Optical amplifiers, Optical fiber networks, Optical noise, DNA. Abstract: As computers have progressed over the last few decades, with their component transistors getting ever smaller and ever more numerous on a single chip, that relentless progress, famously described by Moore's Law, has begun to bump up against fundamental physical limits to what can be done with the present etched-lines-on-silicon technology. But now, a new twist involving an inorganic molecule that has a DNA-like helical shape may provide an alternative pathway that could shrink transistors down to atom-sized scales. And even DNA molecules themselves might ultimately become the bits and bytes and logic gates of the future.
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3,288
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Please write an abstract with title: MedCloud: Cloud-Based Disease Surveillance and Information Management System, and key words: Diseases, Surveillance, Cloud computing, Stakeholders, Data visualization, Information management. Abstract: Outbreaks can overwhelm fragile health systems that lack the tools, infrastructure, policies, and systems to keep communities healthy and safe. Timely detection, preparedness, and appropriate response are essential for limiting both the loss of human life and social economic disaster due to disease outbreaks. Countries must build effective and sustainable disease surveillance and reporting systems that mobilize all levels of the health system-including communities for crisis response. In Pakistan currently, there is no centralize Health Information and Diseases Surveillance System. The current disease surveillance system is a completely manual system, where diseases are being reported through hard copies or print and electronic media. Because of the delayed process, the outbreaks are usually heard through print and electronic media. The ineffective reporting system not only creates problems in managing the countermeasures against a disease outbreak but is likely to cause mass hysteria among the people. In this paper, we propose MedCloud, a cloud-based health management system for disease surveillance and early warning with trend analysis. The proposed system provides a nationwide connected disease surveillance system with the provision of statistical data processing, data validation, and secure backup features. MedCloud is flexibly designed to easily incorporate new plugins. It uses cloud virtual machines to dynamically handle users sessions; thus, can easily and efficiently be accessed using the Internet.
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3,289
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Please write an abstract with title: Solar Array Performance of a Geostationary Mission with Full Electric Orbit Raising, and key words: Orbits, Space vehicles, Degradation, Attitude control, Protons, Space radiation, Solar radiation. Abstract: This paper reports the solar array performance of a Maxar spacecraft during a 4-month geostationary transfer orbit (GTO) through the Van Allen radiation belts. During this period, the spacecraft used its stationary plasma thrusters (SPTs) to propel from Low Earth Orbit (LEO) to Geostationary Orbit (GEO). As expected, solar array experienced degradation due to the belts' trapped radiation. The paper provides the required analyses to predict the solar array degradation and the uncertainty of the prediction from available radiation models. The solar array flight telemetry performance versus predicted solar array performance are presented.
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3,290
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Please write an abstract with title: Convolutional Neural Network-Based License Plate Recognition Techniques: A Short Overview, and key words: Scientific computing, Electric breakdown, License plate recognition, Optical character recognition software, Convolutional neural networks, Monitoring, Computational intelligence. Abstract: Identification of vehicle license plate has become more practical within the last decade in many applications such as; storage and retrieval of vehicular inflow records, automatic toll collection, parking fee payment, traffic monitoring, tracking of moving vehicles, recovery of stolen vehicles, etc. A lot of researches have been carried out on license plate recognition which has led to the development of new techniques and modification of existing techniques. This study provides a breakdown of some techniques used for the implementation of license plate recognition systems, with significant emphasis on Convolutional Neural Network (CNN). The strength and weaknesses of the highlighted techniques were discussed. Also, areas of further improvement of some of the selected CNN-based techniques were suggested.
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3,291
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Please write an abstract with title: Improving migration by diversity, and key words: Computer science, Genetic algorithms, Content addressable storage, System performance, Context-aware services, Genetic programming, Cows. Abstract: We present an improvement to distributed GAs based on migration of individuals between several concurrently evolving populations. The idea behind our improvement is to not only use the fitness of an individual as criterion for selecting the individuals that migrate, but also to consider the diversity of individuals versus the currently best individual. We experimentally show that a distributed GA using a weighted sum of fitness and a diversity measure for selecting migrating individuals finds the known optimal solutions to benchmark problems from literature (that offer a lot of local optima) on average substantially faster than the distributed GA using only fitness for selection. In addition, the run times of several runs of the distributed GA to the same problem instance vary much less with our improvement than in the base case, thus resulting in a more stable behavior of a distributed GA of this type.
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3,292
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Please write an abstract with title: Optimal Beam Separation in Auxiliary Beam Pair-based Initial Access in mmWave D2D Networks, and key words: Gain, Device-to-device communication, Delays, Array signal processing, Antenna arrays, Receivers. Abstract: In this paper, we propose the optimization of beam separation in auxiliary beam pair (ABP) schemes to optimize the device discovery process in a millimeter wave (mmWave) device-to-device (D2D) network. Specifically, two beams are generated both at the transmitter (TX) and receiver (RX) for user detection through directional beamforming (BF). BF is employed by either splitting the uniform linear array into two halves (Auxiliary-Half (AH) scheme) or utilizing the whole antenna array (Auxiliary-Full (AF) scheme). It is shown that the separation between two beams plays a vital role in device discovery. Optimum values of probability of miss detection (PMD) and discovery delay (DD) are obtained for a suitable combination of beam pair separation at both TX and RX. Moreover, it is shown that the narrowest possible beams at TX and RX do not improve the detection probability in either AH or AF schemes.
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3,293
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Please write an abstract with title: Design of Flexible and Wearable Antenna for 5G IoT Application, and key words: 5G mobile communication, Resonant frequency, Reflector antennas, Scattering parameters, Reflection coefficient, Internet of Things, Antennas. Abstract: In this paper, a flexible and wearable antenna for 5G IoT (Internet of things) applications using polytetrafluoroethylene (PTFE) substrate has been proposed. The antenna design was carried out using meander line type micro strip antenna with appropriate size reduction for Fifth Generation (5G) Internet of Things (IoT) applications. The main challenge to design a wearable antenna is its size as in the applications very small space is given to fit in the antenna. The main aim is to propose a flexible, wearable, light weight and cost-effective antenna with improvised performance. The antenna displays triple band at 2.52 GHz, 3.8 GHz and 5.58 GHz with excellent reflection coefficient and gain.
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3,294
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Please write an abstract with title: Understanding the evolution of NSAID: a knowledge domain visualization approach to evidence-based medicine, and key words: Visualization, Drugs, Clinical trials, Chaos, Time factors, Arthritis, Colon, Cancer, Cardiac arrest, Medical control systems. Abstract: Finding the most rigorous, updated, and well received clinical evidence is a crucial and challenging task in the practice of evidence-based medicine (EBM). In this article, we describe a knowledge domain visualization-based quantitative approach that is designed to support the task of searching for high-quality clinical evidence in the medical literature. We illustrate the use of this new approach with the knowledge domain of non-steroidal anti-inflammatory drugs (NSAIDs). A sample of the literature is visualized in a base map depicting structural and temporal properties of emerging themes and references made by such themes over time. In addition, the visualization highlights the rigorousness of a published clinical trial in terms of the type of study design retrieved dynamically from PubMed. The contribution of this approach is that it offers users an integrated search environment so that the rigorousness, recentness, and consensus of clinical evidence can be assessed with the support of visual exploration facilities.
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3,295
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Please write an abstract with title: Predicting Places of Revelation of Quran’s Verses, and key words: Radio frequency, Clustering algorithms, Classification algorithms, Training, Forestry, Ethics, Testing. Abstract: Classical scholars mostly relied on the topics discussed in the verses of Quran to identify their places of revelation. They didn't have access to today’s computing facilities. That’s why they didn’t and even couldn’t efficiently use numeric properties like word length, word count, letter count, etc. to classify verses of the Quran. To the best of our knowledge, these properties haven't been fully exploited for this purpose till today. In this work, we tried to fill this gap. We wrote a Java program that creates a feature-matrix consisting of 64 features for each verse by analyzing its contents. We split this feature matrix into a training set and a testing set and used the training set to train seven classifiers in WEKA. Then we applied the trained model on the testing set. We found that with both 80% and 90% split as well as with 10-fold cross-validation, Decision Table classifier performed the best (with an accuracy around 98%) in classifying verses for both types of vectorization methods we employed. When we removed the chapter-number attribute from our feature-matrix, the highest accuracy dropped to 80-82% for each (split, vectorization-method) combination and Random Forest classifier turned out to be the best performer. When we ignored both chapter number and verse number, Random Forest remained the best performer in almost every case but its accuracy dropped slightly to 78-80%. We also applied five clustering algorithms for the same purpose and found that Canopy algorithm achieves the highest accuracy (around 74%) in every experiment. Each classification and clustering algorithm took less than two seconds to run. Together, these results suggest that it is possible to efficiently and quite accurately classify verses of Quran using only their constituent characters and other features. These results suggest that the place of revelation of the verses of Quran have high correlation with the numeric properties of their constituents.
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3,296
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Please write an abstract with title: Machine Learning based Diabetes Prediction using Decision Tree J48, and key words: Diabetes, Decision trees, Machine learning, Diseases, Classification algorithms, Data mining, Conferences. Abstract: Gestational diabetes is found among majority of the Indian pregnant women, when un-attended may give birth defects to child. Diabetes, which is caused by the rise in level of glucose in blood, has many latest devices to identify from blood samples. Diabetes, when unnoticed may bring many serious diseases like heart attack, kidney disease. In this way there is a requirement for solid research and learning models enhancement in the field of gestational diabetes finding and analysis. This research work has proposed a machine learning knowledge, for example, Decision Tree J48 calculation for diabetes forecast. Decision Tree is one of the powerful classification models. The dataset considered of 768 patients data with major 8 features and a target column with result "Positive" or "Negative". Experiment is done with weka, outcome of our demonstration shows that Decision Tree J48 calculation gives more efficiency with less processing time.
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3,297
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Please write an abstract with title: Some ionospheric factors affecting the coverage of an HF/VHF direct broadcasting satellite service, and key words: Satellite broadcasting, Hafnium, Ionosphere, Frequency, Earth, Radio spectrum management, Absorption, Orbits, Electrons, Performance loss. Abstract: A study has been undertaken to assess the effects of the ionosphere on the performance of a direct broadcasting satellite service operating in the high frequency (HF) band. Results relating to two issues of performance are presented: 1) determining under what conditions a frequency allocated to the broadcasting service can be expected to reach the surface of the earth from a satellite and 2) the loss of signal strength due to passage through the ionosphere, it was found that if high frequency broadcast services are to be provided on a worldwide basis using satellite platforms, the satellites need to be optimally configured for the intended service area. Also, a 3 dB loss of signal strength is expected due to ionospheric absorption.
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3,298
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Please write an abstract with title: Mutual Coupling Reduction of Slot Array Antenna for 5G Millimeter-wave Handset, and key words: Mutual coupling, Telephone sets, Gain, Phased arrays, Switches, Surface waves. Abstract: A planar switchable phased array has been proposed for 5G handset terminals at 28GHz. It consists of three subarrays. Each subarray contains eight radiating slots. The three subarrays share the same ground plane and can steer their beams to three distinct regions. By switching between the three subarrays, a three-dimensional (3-D) coverage of the terminal is obtained. However, the array suffers from relatively high mutual coupling. Hence, in this work, an effective decoupling technique is proposed to reduce the mutual coupling between adjacent elements of each subarray, while preserving the matching conditions and radiation characteristics of the original handset array. The isolation within each array is enhanced more than 5dB, achieving an isolation larger than 18dB at the center frequency, resulting in smaller active reflection and larger scanning angle.
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3,299
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Please write an abstract with title: Mathematical Model of Diffuse Reflection Light of Materials Used In Agriculture, and key words: Monte Carlo methods, Atmospheric measurements, Computational modeling, Industrial engineering, Optics, Mathematical models, Reflection. Abstract: There has been developed and obtained theoretical dependence of the diffuse reflection coefficient $\rho$ from the angle of incidence of the light beam $\alpha$. To test the adequacy of the mathematical model there has been developed a computer programme admitting realization of the diffuse reflection of the light thus based on the Monte Carlo method. The results of computer calculations of the diffuse reflection coefficient, with an error not exceeding 0.03%, are consistent with the proposed theoretical dependence $\rho(\alpha)$. With the values of the angle $\alpha$ in the range 0°-12°, values of the diffuse reflection coefficient are designated within the range 0$.395\lt\rho\lt0.405$. The area of consistency for a mathematical model and experimental results is specified. The region of the spectrum where reference values of the reflection coefficient of materials and objects are consistent with the value of 0.4 is principally in the visible part. The area of agreement in the ultraviolet part of the spectrum has been determined by the measurement results made in the Institute of Atmospheric Optics after V. E. Zuev SB RAS, at $\alpha=8^{\circ}$. Conducted researches had been followed by the conclusions formulated as follows: the obtained function $\rho(\alpha)$ admits to theoretically estimate the diffuse reflection coefficient for the acknowledged angle of incidence of the beam light; and the developed computer program allows to calculate the diffuse reflection coefficient due to averaging at random directions of the reflected beam; values of the theoretical and of the calculated diffuse reflection coefficient are well consistent at small light angles with the experimental values $\rho=0.4$ for the materials used in the agriculture.
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