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15,300 | Please write an abstract with title: Prototyping a residential gateway using Xilinx ISE, and key words: Prototypes, Roentgenium, SONET, Software prototyping, Wavelength division multiplexing, Field programmable gate arrays, Optical fiber networks, Optical fiber cables, IEC standards, ISO standards. Abstract: This paper presents a residential gateway (RG) prototyping process using Xilinx Integrated Software Environment (ISE) version 6.1i. The RG was designed for broadband residential multiservices based on a SONET over DWDM (dense wavelength division multiplexing) access network. The RG design was targeted for Xilinx Virtex II FPGA for prototyping purpose. The RG core design and the prototyping process using Xilinx ISE, including simulation and implementation, are discussed in this paper. |
15,301 | Please write an abstract with title: Data, User and Power Allocations for Caching in Multi-Access Edge Computing, and key words: Servers, Resource management, Games, Interference, NOMA, Intercell interference, Distributed databases. Abstract: In the multi-access edge computing (MEC) environment, app vendors’ data can be cached on edge servers to ensure low-latency data retrieval. Massive users can simultaneously access edge servers with high data rates through flexible allocations of transmit power. The ability to manage networking resources offers unique opportunities to app vendors but also raises unprecedented challenges. To ensure fast data retrieval for users in the MEC environment, edge data caching must take into account the allocations of data, users, and transmit power jointly. We make the first attempt to study the Data, User, and Power Allocation (DUPA$^3$) problem, aiming to serve the most users and maximize their overall data rate. First, we formulate the DUPA$^3$ problem and prove its $\mathcal {NP}$-completeness. Then, we model the DUPA$^3$ problem as a potential DUPA$^3$ game admitting at least one Nash equilibrium and propose a two-phase game-theoretic decentralized algorithm named DUPA$^3$Game to achieve the Nash equilibrium as the solution to the DUPA$^3$ problem. To evaluate DUPA$^3$Game, we analyze its theoretical performance and conduct extensive experiments to demonstrate its effectiveness and efficiency. |
15,302 | Please write an abstract with title: Tensor Nuclear-Norm Minimization for Snapshot Compressive Imaging Cameras, and key words: Performance evaluation, Image sensors, Tensors, Optical variables measurement, Reconstruction algorithms, Cameras, Minimization. Abstract: Snapshot compressive imaging (SCI) cameras optically compress high-speed video frames using low-resolution sensors into one measurement frame. The key to implement efficient SCI cameras is accurate reconstruction algorithms. However, existing works are not satisfactory due to either low fidelity or extensive running time. In this paper, we propose a novel tensor nuclear-norm minimization scheme that achieves fast and accurate reconstruction for SCI cameras. First, we model the high-speed video as a low tubal-rank tensor and exploit the low tubal-rank property to reconstruct the high-speed video frames from the measurement frame. Second, we propose a novel tensor nuclear-norm minimization scheme using Alternating Direction Method of Multiplier algorithm, called TNN-ADMM. Finally, we present performance evaluations on two synthetic videos and one real SCI camera video. The propsed TNN-ADMM scheme exhibits an average improvement of 3.5 dB in PSNR over the GAP-TV algorithm, and reduces DeSCI's 8 hours' running time to less than 6 minutes. |
15,303 | Please write an abstract with title: Fünfiiber-Drone: A Modular Open-Platform 18-grams Autonomous Nano-Drone, and key words: Power demand, Robot vision systems, Sensor systems, Optical sensors, Task analysis, State estimation, Open source software. Abstract: Miniaturizing an autonomous robot is a challenging task - not only the mechanical but also the electrical components have to operate within limited space, payload, and power. Furthermore, the algorithms for autonomous navigation, such as state-of-the-art (SoA) visual navigation deep neural networks (DNNs), are becoming increasingly complex, striving for more flexibility and agility. In this work, we present a sensor-rich, modular, nano-sized Unmanned Aerial Vehicle (UAV), almost as small as a five Swiss Franc coin - called Fünfliber - with a total weight of 18g and 7.2cm in diameter. We conceived our UAV as an open-source hardware robotic platform, controlled by a parallel ultra-low power (PULP) system-on-chip (SoC) with a wide set of onboard sensors, including three cameras (i.e., infrared, optical flow, and standard QVGA), multiple Time-of-Flight (ToF) sensors, a barometer, and an inertial measurement unit. Our system runs the tasks necessary for a flight controller (sensor acquisition, state estimation, and low-level control), requiring only 10% of the computational resources available aboard, consuming only 9mW - 13x less than an equivalent Cortex M4-based system. Pushing our system at its limit, we can use the remaining onboard computational power for sophisticated autonomous navigation workloads, as we showcase with an SoA DNN running at up to 18Hz, with a total electronics' power consumption of 271mW. |
15,304 | Please write an abstract with title: Active Learning in Online Computer Systems Course, and key words: Education, Prototypes, Registers, Computational modeling, Instruction sets, Computer science, Springs. Abstract: Active learning has been proven to improve students learning outcomes effectively. An online active learning pedagogy model is designed and applied in online Computer Systems course this Spring. The model includes five cycle phases which cover online feedback between students and instructor before class, active discussion in the online class, and asynchronous interaction after class in the virtual education environment. Based on the data from students’ questionnaires and the test score ratio shows the active learning pedagogy model is efficient for online education. |
15,305 | Please write an abstract with title: Andrew K. Packard (July 7, 1960 - September 30, 2019) [Obituary], and key words: Obituaries, Packard, Andrew K.. Abstract: Prof. Andrew K. Packard, loving husband and father and adored professor, passed away on September 30, 2019 at the age of 59. He died as he lived, surrounded by friends and family. Andy is survived by his wife Johanna, son Zachary, and his mother and sisters. Andy was born on July 7, 1960 in Chicago, Illinois, to Ann and Max Packard. He grew up in a large, loving family with his sisters Hilary, Betsy, Jean, and Kathie. He received the B.S. degree in mechanical engineering from the University of Illinois, Urbana-Champaign, followed by his master’s and Ph.D. degrees from the University of California (UC), Berkeley. He completed his postdoctoral work at the California Institute of Technology (Caltech). He served as a faculty member at UC Santa Barbara before joining the faculty at UC Berkeley in 1990. |
15,306 | Please write an abstract with title: Benefits of Strategically Sizing Wind-Integrated Energy Storage and Transmission, and key words: Wind energy generation, Wind energy, Generators, Wind power generation, Investment, Batteries. Abstract: We examine the behavior of a strategic firm that invests-in and operates wind, energy storage, and transmission. The capacity of the energy storage and transmission are co-optimized with the firm's wind-supply and energy-storage offers into a centrally dispatched electricity market. We employ a bi-level stochastic optimization model. The upper level determines the capacities and offering strategies to maximize the firm's expected profits. Multiple lower-level problems represent market clearing under different operating conditions, which capture uncertainties. The resulting large-scale optimization model is solved using multi-cut Benders's decomposition. The model is applied to a case study that is based on Alberta's electricity market. |
15,307 | Please write an abstract with title: Decomposability and Parallel Computation of Multi-Agent LQR, and key words: Regulators, Control design, Simulation, Computational modeling, Reinforcement learning, Robustness, Matrix decomposition. Abstract: Individual agents in a multi-agent system (MAS) may have decoupled open-loop dynamics, but a cooperative control objective usually results in coupled closed-loop dynamics thereby making the control design computationally expensive. The computation time becomes even higher when a learning strategy such as reinforcement learning (RL) needs to be applied to deal with the situation when the agents dynamics are not known. To resolve this problem, we propose a parallel RL scheme for a linear quadratic regulator (LQR) design in a continuous-time linear MAS. The idea is to exploit the structural properties of two graphs embedded in the Q and R weighting matrices in the LQR objective to define an orthogonal transformation that can convert the original LQR design to multiple decoupled smaller-sized LQR designs. We show that if the MAS is homogeneous then this decomposition retains closed-loop optimality. Conditions for decomposability, an algorithm for constructing the transformation matrix, a parallel RL algorithm, and robustness analysis when the design is applied to non-homogeneous MAS are presented. Simulations show that the proposed approach can guarantee significant speed-up in learning without any loss in the cumulative value of the LOR cost. |
15,308 | Please write an abstract with title: Development of Event triggered Feed forward Control Scheme for Fed-Batch E.coli Fermentation Process, and key words: Temperature sensors, Biological system modeling, Process control, Predictive models, Real-time systems, Data models, Biomass. Abstract: This paper presents development of Event Triggered Feed Forward Control (ET-FFC) scheme for K12 Escherichia coli (E.coli) fermentation process. Modeling and control of E.coli fermentation is a challenging task due to strong influence of the risk factors/disturbance like variations in pH, temperature, agitator speed, substrate concentration and air flow rate on biomass yield. The main idea is to develop event triggered Feed forward control scheme to reduce the influence of known disturbance on biomass by minimizing Control Energy(CE) and Integral Square Error (ISE). Real time data of Biomass concentration, substrate feed rate and temperature are collected from the 1.5 Liter laboratory experimental Bioreactor setup. Based on the data, data-driven model based Feedback Controllers (FBC) namely Proportional Integral (PI) controller and Model Predictive controller (MPC) are designed to control Biomass concentration by manipulating substrate feed rate. In addition, Feed-Forward controller is designed for known temperature disturbance. When the temperature disturbance event is detected, FF controller takes control action to suppress its effect on yield. Finally, the closed loop performances of the E.coli fermentation process with proposed controllers are evaluated and analyzed through simulation. Further, a comparative study is carried out for the closed loop system with PI based ET-FFC and proposed MPC based ET-FFC schemes qualitatively as well as quantitatively. The results show that MPC based ET-FFC scheme provides better performances with minimum ISE over PI based ET-FFC scheme. |
15,309 | Please write an abstract with title: Review of Research on the Curriculum for Artificial Intelligence and Industrial Automation based on Edge Computing, and key words: Schedules, Automation, Education, Learning (artificial intelligence), Optimization, Edge computing. Abstract: In the background of edge computing becoming an important technology of China’s new infrastructure construction, it is necessary for colleges and universities to set up a new professional curriculum system for edge computing. It is construction and learning from the refinement of artificial intelligence which is easier to industrialize. Through the interdisciplinary integration and optimization construction of the curriculum, this course system is suitable for universities. According to developed course content, design the teaching schedule, and then, based on this scheme, we will cultivate edge computing research and application-oriented talents, and support the transformation and upgrading of industrial automation to intelligent. |
15,310 | Please write an abstract with title: EMG-Based Gestures Classification Using a Mixed-Signal Neuromorphic Processing System, and key words: Neuromorphic engineering, Biomedical signal processing, Recurrent neural networks, Wearable sensors. Abstract: The rapid increase of wearable sensor devices poses new challenges for implementing continuous real-time processing of physiological data. Neuromorphic sensory-processing devices can enable both the measurement of bio-signals and their processing locally in compact embedded wearable systems. In particular, mixed-signal spiking neural networks implemented on neuromorphic processors can be integrated directly with the sensors to extract temporal data-streams in real-time with very low power consumption. In this work, we present a neuromorphic approach for classifying spatio-temporal data from electromyography (EMG) signals, which paves the way toward the realization of compact wearable solutions for neuroprosthetic control. Here we extend previously proposed delta-encoding methods to transform bio-signals into spike trains and use a spiking Recurrent Neural Network (SRNN) architecture to extract features from them. The SRNN was first simulated in software to find the optimal set of hyperparameters, and then validated on the neuromorphic hardware, with a difference in the performance of less than 2%. We describe how biologically plausible mechanisms such as Spike-Timing Dependent Plasticity (STDP) and soft Winner-Take-All (WTA) networks can be exploited to classify the EMG signals and show how their combined use in EMG data classification achieves competitive results with different datasets. Specifically, the classification performance for the Roshambo EMG dataset, which has three different classes, is above 85%, and for the basic finger movements dataset from the Ninapro database, which has eight different classes, reaches 55% accuracy. |
15,311 | Please write an abstract with title: Emulation of robots interacting with environment, and key words: Emulation, Robots, Orbital robotics, Manipulator dynamics, Space technology, Computational modeling, Robotic assembly, Gravity, Space vehicles, Humans. Abstract: In this paper, we present a methodology for emulation of a target robot operating in a complex environment by using an actual robot. The emulation scheme aims to replicate the dynamical behavior of the target robot interacting with an environment, without dealing with a complex calculation of the contact dynamics. This method forms a basis for the task verification of a flexible space robot. The actual emulating robot is structurally rigid, while the target robot can represent any class of robots, e.g., flexible, redundant, or space robots. Although the emulating robot is not dynamically equivalent to the target robot, the dynamical similarity can be achieved by using a control law developed herein. The effect of disturbances and actuator dynamics on the fidelity and the contact stability of the robot emulation is thoroughly analyzed. The concept of robot emulation is demonstrated by performing a number of preliminary experiments for emulation of flexible-joint robots. |
15,312 | Please write an abstract with title: Transition Graphs for SAR Image Texture Characterization: An Exploratory Study, and key words: Image texture, Image edge detection, Vegetation mapping, White noise, Radar polarimetry, Polarimetric synthetic aperture radar, Contamination. Abstract: We investigate the use of ordinal pattern transition graphs in the characterization of PolSAR image textures. Chagas et al. [4] proposed WATG, a transition graph analysis which includes the amplitude information of texture samples in the graph edges. This approach led to good results in the characterization and classification of data from urban, oceanic, and vegetation regions. In this work, we study how this approach behaves when considering the three intensity channels of PolSAR data, and its behavior when the samples are not homogeneous. |
15,313 | Please write an abstract with title: Image Detection in Noisy Images, and key words: Visualization, Image recognition, Surveillance, Object detection, Benchmark testing, Real-time systems, Sensors. Abstract: The problem of image noise is prevalent in various visual recognition tasks. This problem arises due to multiple factors like insufficient illumination, low-quality camera sensors, background-clutters, etc. Low-quality images incur degraded performance for visual recognition tasks like classification, object detection, because of the noise present in the image. Thus, mostly the latest image recognition benchmarks and methods, such as Pascal Visual Object Classes Challenges and Microsoft Common Objects in Context Challenges, rely primarily on clean and high-definition images. Furthermore, image noise is a typical problem in real-time applications like surveillance, autonomous vehicles, etc. To tackle this bothersome problem of underperformance of visual recognition tasks, particularly object detection, due to inclusion of noise in real-time scenarios, a technique has been proposed to reduce the image noise's impact on the object detection task and improve its performance altogether. A two-phase pipeline is introduced, in which the first phase consists ofremoving noise from the low-quality image, and the second stage includes accomplishing the object detection process by employing the standard Single-shot multibox object detector. The proposed approach is evaluated on the Pascal Visual Object Classes benchmark. The detection results and image denoising results exhibit the efficiency of the proposed technique for reliable object detection with varying image noise levels. |
15,314 | Please write an abstract with title: Towards Spin-Multiphoton Entanglement using Quantum Dots with Asymmetric Waveguide Coupling, and key words: Optical waveguides, Quantum dots, Quantum entanglement, Laser excitation, Probes, Couplings, Stimulated emission. Abstract: We demonstrate selectively enhanced dipoles of an InAs quantum dot embedded in a nanophotonic waveguide, thereby forming optical cycling transitions, a basic tool for scalable spin-multiphoton entanglement generation. |
15,315 | Please write an abstract with title: Project Overview for Step-Up!CPS - Process, Methods and Technologies for Updating Safety-critical Cyber-physical Systems, and key words: Collaboration, Cyber-physical systems, Software, Monitoring, Contracts. Abstract: We describe the challenges addressed by the three year German national collaborative research project Step-Up!CPS that is currently in its third year. The goal of the project is to develop software methods and technologies for modular updates of safety-critical cyber-physical systems. To make this possible, contracts are utilized, which formally describe the behaviour of an update and make it verifiable at different times of the update life cycle. We have defined a development process that allows for a continuous improvement of such systems by monitoring their operation, identifying the need for updates, and development and deploying these updates in a safe and secure manner. We highlight the points along the update process that are necessary for a secure update and show how we counteract them in a contractually secured update process. |
15,316 | Please write an abstract with title: A path planning strategy for kinematically redundant manipulators anticipating joint failures in the presence of obstacles, and key words: Path planning, Service robots, Kinematics, Orbital robotics, Telecommunication network reliability, Collaboration, Government, Motion control, Humans, Radioactive pollution. Abstract: This work considers the failure tolerant operation of a kinematically redundant manipulator in an environment containing obstacles. In particular, the article addresses the problem of planning a collision-free path for a manipulator operating in a static environment such that the manipulator can reach its desired goal despite a single locked-joint failure and the presence of obstacles in the environment. A method is presented that searches for a continuous obstacle-free space between the starting configuration and the desired final end-effector position, which is characterized in the joint space by the goal self-motion manifold. This method guarantees completion of critical tasks in the event of a single locked-joint failure in the presence of obstacles. |
15,317 | Please write an abstract with title: Block Codes for Energy-Harvesting Sliding-Window Constrained Channels, and key words: Block codes, Art, Table lookup, Windows, Internet of Things, Systematics. Abstract: Energy-harvesting sliding-window constrained block codes guarantee that within any prescribed window of ℓ consecutive bits the constrained sequence has at least t, t ≥ 1, 1's. Prior art code design methods build upon the finite-state machine description of the (ℓ, t) constraint, but as the number of states equals I choose t, a code design becomes prohibitively complex for mounting I and t. We present a new block code construction that circumvents the enumeration of codewords using a finite-state description of the (ℓ, t)-constraint. The codewords of the block code are encoded and decoded using a single look-up table. For (ℓ = 4, t = 2), the new block codes are maximal, that is, they have the largest possible number of codewords for its parameters. |
15,318 | Please write an abstract with title: Hardware Implementation and Evaluation of the HDDM, and key words: Performance evaluation, Global navigation satellite system, Software algorithms, Interference, Receivers, Manipulators, Hardware. Abstract: Interferences can significantly degrade the performance of global navigation satellite system (GNSS) receivers. Therefore, mitigation methods are required to ensure reliable operations. However, as there are different types of interferences, robust, multi-purpose mitigation algorithms are needed. The high-rate DFT-based data manipulator (HDDM) algorithm is a promising mitigation method, but so far has only been evaluated in theory and software. This paper presents a hardware implementation of the HDDM algorithm and its evaluation in an exemplary hardware configuration with comparison to the interference mitigation of a high-end professional receiver. Results with interferences achieve the same or improved performance. With more complex interferences, like frequency hopping or pulsed, the HDDM shows even better performance than state of the art. |
15,319 | Please write an abstract with title: An Architecture for Distributed Energies Trading in Byzantine-Based Blockchains, and key words: Blockchains, Games, Smart cities, Cogeneration, Resistance heating, Security, Throughput. Abstract: With the development of smart cities, not only are all corners of the city connected to each other, but also connected from city to city. They form a large distributed network together, which can facilitate the integration of Distributed Energy Stations (DESs) and corresponding smart aggregators. Nevertheless, because of potential security and privacy protection arising from trustless energies trading, how to make such energies trading go smoothly is a tricky challenge. In this paper, we propose a blockchain-based multiple energies trading (B-MET) system for secure and efficient energies trading by executing a smart contract we design. Because energies trading requires the blockchain in B-MET system to have high throughput and low latency, we design a new byzantine-based consensus mechanism (BCM) based on node’s credit to improve efficiency for the consortium blockchain under the B-MET system. Then, we take combined heat and power (CHP) system as a typical example that provides distributed energies. We quantify their utilities and model the interactions between aggregators and DESs in a smart city by a novel multi-leader multi-follower Stackelberg game. It is analyzed and solved by reaching Nash equilibrium between aggregators, which reflects the competition between aggregators to purchase energies from DESs. In the end, we conduct plenty of numerical simulations to evaluate and verify our proposed model and algorithms, which demonstrate their correctness and efficiency completely. |
15,320 | Please write an abstract with title: Comparing JavaBeans and OSGi towards an integration of two complementary component models, and key words: Java, Software engineering, Read only memory, Ear, Software reusability, Application software, Sun. Abstract: In today's software engineering practices, building applications from components is the ongoing trend. What can be noticed however is that there really is not a clear consensus about the definition of components, and instead in the literature we find many definitions of what components are. This renders a comparison between component models difficult. However, it is possible to compare different component models over a list of characteristics that several authors agree should be found in a component model. In this article, Sun's JavaBeans and the Open Services Gateway Initiative's framework (OSGi) are compared. These are two technologies that target very different types of applications. Their study reveals, however, that both technologies cover, at different levels, a set of important features that characterize components. It also reveals that these component models are in some ways complementary. The paper concludes by giving a proposal to integrate these two technologies to obtain a more complete component model. |
15,321 | Please write an abstract with title: Terahertz MIMO Fading Analysis and Doppler Modeling in a Data Center Environment, and key words: Wireless communication, Fading channels, Antenna measurements, Data centers, Power measurement, Power cables, Atmospheric modeling. Abstract: In this paper, we present results from a Terahertz (THz) channel measurement campaign in a data center environment. We analyze propagation parameters, such as pathloss, shadowing gain, and RMS delay spread. Amplitude fading statistics in a 4 × 4 Multiple-Input-Multiple-Output (MIMO) channel are also investigated. Furthermore, Doppler shift in THz bands due to the effect of cooling airflow turbulence, which causes cables (lying in the wireless propagation path) to vibrate is also measured. A two-dimensional (2-D) geometrical propagation model that includes moving scatterers (cables) is introduced. From the 2-D model, a corresponding Doppler power spectrum (DPS) is derived and validated with measured data. This work is pertinent to THz wireless systems design for a data center environment. |
15,322 | Please write an abstract with title: Discrimination of Single-channel Radar Micro-doppler of Human Joints Based on Kinect Sensor, and key words: Legged locomotion, Knee, Visualization, Radar measurements, Tracking, Target recognition, Radar. Abstract: In recent years, the micro-Doppler signature (MDS), human MDS in particular, has become a hot topic for target recognition and classification.All limbs’ periodic oscillations and torso’s relatively stable motion of a pedestrian are representative micro motions, which all induce micro-Doppler (MD) in the radar data.The MDS of a pedestrian can provide his/her motion information (e.g., velocity and step length) and can be exploited to identify his/her motion state (such as walking or running). However, if we need to conduct some further quantitative studies on the MD data of an interested joint such as the left knee joint of the pedestrian, which may have a contribution to human gait recognition, health monitoring, etc., the human whole MDS of the pedestrian fails to meet the requirements.In this paper, in order to discriminate the MD data of any interested joint of pedestrian using single-channel radar, we propose to use the Kinect sensor, which is a low-cost motion tracking device developed by Microsoft. The advantage of Kinect is that it can provide the motion data of every joint of human body, although it has lower accuracy compared with radar and it is easily affected by light intensity and occlusion. Finally, the results of measured experimental data validate this method and show a good visual consistency with Kinect and radar data. |
15,323 | Please write an abstract with title: Discussion, and key words: Poles and towers, Lightning, Wires, Surges, Surge protection, Storms, Space missions. Abstract: Professor J. M. Meek: I am exceedingly glad to have had the opportunity of hearing the paper to-night. It is only within the last two weeks or so that I heard about this paper, and have since had great interest in reading it. |
15,324 | Please write an abstract with title: An Algebra-Logical Approach to Modeling of Complex Systems Control Problems, and key words: Calculus, Lattices, Boolean algebra, Frequency modulation, Mathematical model, Semantics, Process control. Abstract: We consider an algebraic approach to the description of modeling methods, in which the generation of structures with different types of logical calculus is based on the use of the concept of “valuation” as a morphism from a set of formulas in the structure, which takes the value of their truth. This allows us to consider the set of formulas of the algebra of logic with the equivalence relation introduced on it as a factor-algebra with a certain structure. The results of modeling of non-classical formal-logical systems, new, generalized formulations of generally recognized rules of inference are presented. The principal novelty of the proposed approach lies in the fact that it opens the way to the formation of a unified formal base of methods for modeling control problems. It is of general significance for modeling problems, since it allows not only to expand the capabilities of methods for modeling control problems, but also forms a methodological base for studying the relationship between them. |
15,325 | Please write an abstract with title: Image reconstruction algorithm for electrical capacitance tomography based on radial basis function neural network, and key words: Image reconstruction, Electrical capacitance tomography, Radial basis function networks, Projection algorithms, Neural networks, Capacitance measurement, Fluid flow measurement, Electric variables measurement, Inverse problems, Software measurement. Abstract: Electrical capacitance tomography (ECT) technique is a new technique for two-phase flow measurement. This paper describes the basic principles of ECT. Forward and inverse problem of ECT are analyzed in detail. The conventional image reconstruction algorithm, i.e., linear back projection algorithm has been given. Then, the new image reconstruction algorithm for ECT based on radial basis function (RBF) neural network has been presented. Using the measurement data obtained from the ECT simulation software developed by the author, the reconstructed images were obtained. Results indicate that RBF neural network is suitable for solving the nonlinear problem of ECT image reconstruction. Comparing with linear back projection algorithm, this algorithm has advantages of higher accuracy. |
15,326 | Please write an abstract with title: Lyapunov Spectra Behavior for Linear Time-Varying Discrete Systems Under Small Perturbations, and key words: Perturbation methods, Behavioral sciences, Stability criteria, Time-varying systems, Asymptotic stability, Numerical stability, Linear systems. Abstract: We investigate the behavior of the Lyapunov spectrum of a linear time-varying discrete system under the action of small perturbations in order to obtain some verifiable conditions for stability and openness of the Lyapunov spectrum. To this end we introduce the concepts of broken away solutions and splitted systems. The main results obtained are a necessary condition for stability and a sufficient condition for the openness of the Lyapunov spectrum, which is given in terms of the system itself. Finally, examples of using the obtained results are presented. |
15,327 | Please write an abstract with title: Branch outage simulation for MVAr flows: bounded network solution, and key words: Power system modeling, Computational modeling, Power system simulation, Reactive power, Computational efficiency, Linear systems, Constraint optimization, Feedback, Error correction, Nonlinear equations. Abstract: Almost all of the methods developed thus far to calculate the post outage quantities in an electric power system use linear models for the sake of computational efficiency. Linear models, however, may cause relatively large computational errors especially for reactive power flows. This paper presents a new line outage simulation method for reactive power flows that minimizes the errors resulting from the use of linear system models. The proposed method formulates a line outage as a local nonlinear constrained optimization problem. Optimization is used as a feedback to correct the errors resulting from linearized equations. The method provides more accurate calculation of post-outage load bus voltage magnitudes with less computational effort. The method is applied to IEEE test systems and the results are compared with those obtained using the full power flow. |
15,328 | Please write an abstract with title: Applicability of a new generation of photonic devices in backbone network scenarios, and key words: Optical fibers, Scalability, Bandwidth, Optical saturation, Optical fiber networks, Optical fiber devices, Transponders. Abstract: This article presents the characteristics of the transponders and optical nodes developed by the QAMeleon project and illustrates an example of application of these systems in an optical backbone. A scalability study shows how with traffic increasing at a rate of 30% per year, high flexible and spectral efficient QAMeleon devices allow the network to scale to carry all the traffic up to 2030 as long as multiple systems are used in parallel on the most heavily loaded nodal degrees. Scalability extends beyond 2030 with the use of nodes with a greater number of ports and with the possible use of C + L band systems instead of C band only. |
15,329 | Please write an abstract with title: Research on Online Course Recommendation Model Based on Improved Collaborative Filtering Algorithm, and key words: Cloud computing, Data analysis, Filtering, Collaborative filtering, Computational modeling, Conferences, Education. Abstract: Aiming at the problem of sparse data and poor recommendation effect in online course recommendation, this paper proposes an improved online course intelligent recommendation model based on user implicit behavior collaborative filtering. Through data analysis, the implicit behavior data such as user login details, learning details and course selection details are mined, and the online course intelligent recommendation is carried out combined with the collaborative filtering algorithm based on items. Based on the operation data of an education platform in recent two years, the experimental results show that the precision and recall rate of the improved collaborative filtering recommendation model are improved under different K values. |
15,330 | Please write an abstract with title: Dynamic analysis of the activley controlled segmented mirror of the W. M. Keck ten-meter telescope, and key words: Mirrors, Telescopes, Control systems, Instruments, Image segmentation, Spatial resolution, Image quality, Space technology, Apertures, Optical design. Abstract: The W. M. Keck Observatory and Telescope are presently under construction on Mauna Kea, Hawaii. When completed in 1990, the telescope will be the world's largest instrument for astronomical observations at visible and infrared wavelengths. The primary mirror has a diameter of 10 m and consists of a mosaic of 36 hexagonal segments, with the orientation of each segment actively controlled. This paper presents an analysis of the dynamic interaction between the segment control system and the telescope structure. Results from computer simulations show improvement in image quality achieved by the control system in response to environmental wind disturbances. |
15,331 | Please write an abstract with title: Grid Code Compliance for Primary Frequency Regulation with DFIG-based Wind Parks in the Mexican Power System, and key words: Doubly fed induction generators, Rotors, Frequency control, Customer relationship management, Wind turbines, Power systems, Software packages. Abstract: Wind parks based on doubly fed induction generators can provide primary frequency regulation if additional control loops are implemented-the blade pitch angle control is used for endowing variable-speed wind turbines with frequency regulation capabilities. This technique is proposed in this paper for wind turbines to provide frequency support in the Mexican power system, which is fully evaluated under the perspective of the Mexican grid code. To this end, the performance of a recently commissioned 180-MW DFIG-based wind farm in Mexico, with pitch angle control for frequency support is studied. In addition, an equivalent model of the mexican power system is assessed using credible scenarios with high wind power penetration and different demand scenarios. The impact of the wind parks is thoroughly assessed under the perspective of the Mexican grid code, identifying under which operating scenarios and wind turbine parameters, the wind parks comply with the requirements imposed by the grid code for primary frequency control. |
15,332 | Please write an abstract with title: The synthesis of CaZn/sub 2/Sb/sub 2/ and its thermoelectric properties, and key words: Thermoelectricity, Temperature, Thermal conductivity, Conducting materials, Zinc, Resistance heating, Conductivity measurement, Electric variables measurement, Doping, Materials testing. Abstract: CaZn/sub 2/Sb/sub 2/ was prepared and examined for use as a high temperature thermoelectric material. It has a high Seebeck coefficient and high electrical conductivity-comparable to /spl beta/-Zn/sub 4/Sb/sub 3/. These two properties are vital in determining the ability of the compound to change heat into electricity isentropically. The dimensionless figure of merit, ZT, a measure of the thermoelectric material's efficiency is defined as ZT = S/sup 2//spl sigma/T//spl lambda/ where S is the Seebeck coefficient, Z the figure of merit, T the temperature, /spl sigma/ the electrical conductivity, and /spl lambda/ the thermal conductivity. However, due to its simple structure, CaZn/sub 2/Sb/sub 2/ has high /spl lambda/. Doping CaZn/sub 2/Sb/sub 2/ with Ga/sup 3+/ or modifying the (Ca, Zn) to Sb ratio was also investigated. Samples were prepared from Zn, Sb, and the binary compound CaSb/sub 2/. They were tested for material composition, structure, and thermoelectric properties. Results of this experiment are presented and discussed as are the applicability of these materials to future thermoelectric use. Conservative estimates show a ZT of .5 at 500/spl deg/C; CaZn/sub 2/Sb/sub 2/ could be a good thermoelectric to use at temperatures above 400/spl deg/C. |
15,333 | Please write an abstract with title: Complexity in the narration of the self A new theoretical and methodological perspective of diagnosis in psychopathology based on the computational method, and key words: Complexity theory, Complex systems, Tools, Psychology, Heart rate variability, Computational modeling. Abstract: Psychopathological diagnostics is affected by structural methodological limitations that make it less effective in clinical and research applications. These limits are related to: the intrinsic characteristics of psychopathological experiences which cannot be described in the third person; to the complexity of the individual-environment system that cannot be studied using methods based on linear causality; to the forms of psychodiagnostic reagents that hypothesize the possibility of obtaining quantitative measurements of psychic phenomena. In order to overcome these limitations, a complex psychodiagnostic evaluation model is presented in which self-report questionnaires, technologies for the evaluation of physiological indices and methods of analysis of data derived from artificial intelligence are integrated. In this project, the objectives of diagnostic evaluations are: emotional experiences articulated according to a phenomenological vision; the relational dynamics analyzed through the complex network method; the biological variations of the organism detected with the HRV. These assessments could converge towards an integrated and ecological knowledge of the individual, naturalistically based, adapted to clinical decisions and research programs. |
15,334 | Please write an abstract with title: An Efficient Key Management Algorithm for Hierarchical Group Communication, and key words: Cryptography, Protocols, National security, Video on demand, Telecommunication traffic, Scalability, Fires, Earthquakes, Tsunami, Tornadoes. Abstract: Even though hierarchical group communication is a prominent communication model for a variety of applications, featured by hierarchical communication rules, it has not been sufficiently investigated in the security literature. In this paper, we introduce private hierarchical group communication and we determine its specific confidentiality requirements, and then we propose an efficient key management protocol satisfying those requirements. This work is done in the frame of a national french project whose consortium includes the international telecom company EADS, INRIA, CNRS and ENST-Paris. The project is called Safe- Cast and deals with group communication in PMR networks that are used mainly by security corps (police, fire fighters, soldiers, and so forth) in areas where it is difficult to have network infrastructures, such as war battles or following a natural disaster (earthquake, tsunami, tornado, or similar). |
15,335 | Please write an abstract with title: Evaluation of harmonics and interharmonics produced by AC/DC/AC conversion systems, and key words: Power system modeling, Switching converters, System testing, Iterative methods, Harmonic analysis, Convergence, Frequency domain analysis, Rectifiers, Inverters, Variable speed drives. Abstract: A new model of line commutated AC/DC/AC conversion systems is presented and discussed. It is based on the inclusion of the modulation function approach inside the iterative harmonic and interharmonic analysis algorithm. The new model allows to perform the evaluation of waveform distortion taking into account comprehensive representations of both supplying and load systems and overcoming their convergence problems and long times of execution. Numerical tests validate the proposed method and demonstrate its result accuracy and computational efficiency in comparison with time domain simulations. |
15,336 | Please write an abstract with title: Successive-Coded Spatial Shift Keying Modulation for MIMO Wireless Communications, and key words: Modulation, Transmitting antennas, Detectors, GSM, Receiving antennas, Slot antennas, Detection algorithms. Abstract: Spatial domain modulation employs spatial degree of freedom to convey information bits. Traditional spatial domain modulation schemes include spatial modulation, spatial shift keying (SSK), and variations of these two schemes. To fully make use of the spatial degree of freedom and improve the achievable data rate of traditional spatial domain modulation schemes, we propose a successive-coded SSK (SC-SSK) modulation scheme. The core of the proposed SC-SSK scheme is a multiple step coded modulation strategy, in which different information bits are mapped to the designed pattern in each step. The constellation of the transmit signals is designed. A QR decomposition based successive detection algorithm is proposed for this particular coded modulation strategy. The achievable rate, the error rate performance, and the computational complexity of the proposed SC-SSK scheme are analyzed in detail. Simulations are carried out to compare the proposed the SC-SSK scheme with the reference spatial domain modulation schemes, and reveal the advantages of the proposed SC-SSK scheme. |
15,337 | Please write an abstract with title: Depth Estimation Under Motion With Single Pair Rolling Shutter Stereo Images, and key words: Cameras, Estimation, Motion estimation, Buildings, Convergence, Pipelines, Feature extraction. Abstract: Many methods have been proposed to process stereo matching for rolling shutter image pairs, they treat all pixels from an image pair in an identical way and require additional estimation approaches to estimate motion states of the camera. However, pixels from a rolling shutter image pair naturally have diverse baseline lengths, and motion estimation methods are unstable for one instantaneous image pair input. In this letter, we present a rolling shutter stereo depth estimation pipeline, which can robustly estimate motion states and depth maps by alternating the estimation of the depth maps and refining the motion states from coarse image levels to fine image levels. What is more, we design a novel cost volume building method for rolling shutter image pairs, which adapts depth candidates to the change of baseline lengths for all pixels. We further demonstrate the usability of the proposed method by constructing a new platform, building an outdoor evaluation dataset, and comparing it with baseline methods. |
15,338 | Please write an abstract with title: ROMY: a multicomponent ring laser for geodesy and geophysics, and key words: Earth rotation variations, Geodetic instrumentation, Earthquake ground motions, Rotational seismology, Seismic instruments, Seismic noise. Abstract: Single-component ring lasers have provided high-resolution observations of Earth's rotation rate as well as local earthquake- or otherwise-induced rotational ground motions. Here, we present the design, construction and operational aspects of ROMY, a four-component, tetrahedral-shaped ring laser installed at the Geophysical Observatory Fürstenfeldbruck near Munich, Germany. Four equilateral, triangular-shaped ring lasers with 12 m side length provide rotational motions that can be combined to construct the complete vector of Earth's rotation from a point measurement with very high resolution. Combined with a classic broad-band seismometer, we obtain the most accurate 6 degree-of-freedom ground motion measurement system to date, enabling local and teleseismic observations as well as the analysis of ocean-generated Love and Rayleigh waves. The specific design and construction details are discussed as are the resulting consequences for permanent observations. We present seismic observations of local, regional and global earthquakes as well as seasonal variations of ocean-generated rotation noise. The current resolution of polar motion is discussed and strategies how to further improve long-term stability of the multicomponent ring laser system are presented. |
15,339 | Please write an abstract with title: LU-GPU: Efficient Algorithms for Solving Dense Linear Systems on Graphics Hardware, and key words: Linear systems, Graphics, Hardware, Matrix decomposition, Concurrent computing, Appropriate technology, Bandwidth, Clocks, Fluid flow, Coprocessors. Abstract: We present a novel algorithm to solve dense linear systems using graphics processors (GPUs). We reduce matrix decomposition and row operations to a series of rasterization problems on the GPU. These include new techniques for streaming index pairs, swapping rows and columns and parallelizing the computation to utilize multiple vertex and fragment processors. We also use appropriate data representations to match the rasterization order and cache technology of graphics processors. We have implemented our algorithm on different GPUs and compared the performance with optimized CPU implementations. In particular, our implementation on a NVIDIA GeForce 7800 GPU outperforms a CPU-based ATLAS implementation. Moreover, our results show that our algorithm is cache and bandwidth efficient and scales well with the number of fragment processors within the GPU and the core GPU clock rate. We use our algorithm for fluid flow simulation and demonstrate that the commodity GPU is a useful co-processor for many scientific applications. |
15,340 | Please write an abstract with title: Parameter Optimization for Energy Efficient Indoor Massive MIMO Small Cell Networks, and key words: Transmitting antennas, Power demand, Biological cells, Genetic algorithms, Massive MIMO, Optimization. Abstract: To better characterize indoor small cell networks (SCN), we consider the blockages caused by interior walls and employ the bounded path loss model to derive the expression for energy efficiency (EE) of a downlink massive multiple-input multiple-output (MIMO) SCN. Our EE expression demonstrates that a higher penetration loss of interior walls leads to a higher EE. For the purpose of maximizing EE, we propose a novel genetic algorithm (GA) based scheme to jointly optimize the number of antennas per base station (BS), the number of users per cell, and the transmission power per antenna. Numerical results show that our proposed scheme can achieve almost the identical EE as the optimal greedy search algorithm, while significantly reducing the computational time. |
15,341 | Please write an abstract with title: 5.3 GHz 1.6 dB NF CMOS low noise amplifier using 0.11 /spl mu/m technology, and key words: Noise measurement, Low-noise amplifiers, CMOS technology, Circuit noise, Wireless LAN, Low voltage, Analog circuits, CMOS digital integrated circuits, CMOS analog integrated circuits, Power amplifiers. Abstract: We fabricated a low noise amplifier (LNA) for a 5 GHz WLAN with a supply voltage of 1.2 V using 0.11 /spl mu/m CMOS technology. Low voltage design is crucial for an analog circuit to use the scaled digital CMOS. Employing the cascode amplifier configuration, we have shown that the LNA has a wide operating margin even at the supply voltage of 1.2 V. The measured LNA revealed an NF of 1.6 dB, a power consumption of 12.5 mW and 8.2 dBm of OIP3 at 5.3 GHz with a supply voltage of 1.2 V. |
15,342 | Please write an abstract with title: Internal Wave Features In The Northeast Atlantic As Imaged by SEASAT-SAR, and key words: Optical surface waves, Sea surface, Surface waves, Image analysis, Optical films, Meteorology, Wind speed, Computerized monitoring, Image processing, Optical materials. Abstract: This paper presents results derived from a study of some 5 million square kilometres of optical survey processed SEASAT-SAR imagery of the Northeast Atlantic. In the study, markings often attributed to internal wave activity were collated on maps which also showed the bathymetry and surface meteorology at the time of each pass. Two thirds of the satellite coverage of the area shows evidence of such internal wave activity. The markings occur in well over one hundred separate locations from Iceland to the Azores. Most appear to be associated with long wavelength, single mode packets. The features occur in conjunction with a wide combination of surface wind speeds and water depths. The paper classifies them according to wind speed, water depth, geographic location and clarity against the image background. The number of observations of internal wave activity has also been related to the number possible for each wind speed and water depth. This work confirms the capability of spaceborne SAR to observe internal wave effects and illustrates the advantage it offers for deriving features of the internal wavefield on a scale unattainable with shipborne measurements. |
15,343 | Please write an abstract with title: High-Performance, Transparent and Flexible Antenna Based on Conductive Nanocomposites, and key words: Radio frequency, Microwave antennas, Dipole antennas, Nanocomposites, Wearable computers, Metasurfaces, Radiofrequency identification. Abstract: Transparent antennas and radio-frequency (RF) components have recently attracted much attention because they can be monolithically integrated with lighting and photodetection devices for creating compact and multi-functional modules. In this work, we theoretically studied and experimentally manufactured high-performance, large-area conductive nanocomposites, which provide the unprecedented optical transparency (~96%) and moderately high electric conductivity (~ 12.5 Ω/sq). We have experimentally demonstrated several transparent antennas working at different frequencies: a flexible printed dipole antenna (2.95 GHz), a high-gain Fabry-Perot (FP) cavity antenna based on the optically-transparent metasurface (8 GHz), and a multifunctional RF -solar energy harvesting platform (~2.4 GHz). Our high-performance transparent antennas may find a broad range of applications in future wearable electronics and internet-of-thing (IoT). |
15,344 | Please write an abstract with title: 1-6 GHz GaAs MMIC Linear Attenuator with Integral Drivers, and key words: Gallium arsenide, MMICs, Attenuators, MESFETs, Voltage control, Attenuation, Bandwidth, Capacitance, Temperature, Frequency. Abstract: This paper describes the performance of a voltage-controlled attenuator with a 12 dB linear attenuation vs. control voltage range. This linear attenuator greatly facilitates the realization of both closed and open loop gain compensation networks. Over the -55°C to 85°C range the attenuator recorded a 7.2 +- 1 dB/V linear transfer function while using only 25 mW from a single 4 V power supply. |
15,345 | Please write an abstract with title: Using Learning Styles to Accommodate for Heterogeneous Groups of Learners in Software Engineering, and key words: Conferences, Unified modeling language, Engineering education, Software engineering. Abstract: Commonly, learning is expected to happen uniformly even in large classes. Typically, instructors can provide only a single learning setting in presence courses. Yet, student groups are heterogeneous in terms of their learning styles. This paper presents a learning concept which uses Kolb’s Learning Style Inventory to address different groups of learning habits adequately. This learning concept is used as a pilot in an introductory course on software engineering for learning modelling with the Unified Modelling Language. |
15,346 | Please write an abstract with title: Distributed Nash Equilibrium Seeking Dynamics With Discrete Communication, and key words: Nash equilibrium, Heuristic algorithms, Games, Cost function, Directed graphs, Real-time systems, Costs. Abstract: In this brief, we aim to provide a distributed Nash equilibrium seeking algorithm in continuous time with discrete communications. A group of agents are considered playing a continuous-kernel noncooperative game over a network. The agents need to seek the Nash equilibrium when each player cannot get the overall action profiles in real time, rather are only able to get information from its networked neighbors. Meanwhile, a continuous-time dynamics is discussed for the players to update their variables, but the communications over the network are only assumed to allow at discrete-time instants, since continuous-time communications are prohibitive and cumbersome in practice. First, the periodic communication is considered at a fixed interval, and the solvability of Nash equilibrium seeking is shown with discrete communications. Then, an event-trigger communication scheme is proposed to further reduce the communication rounds. Nevertheless, the event-trigger communication scheme requires each player continuously monitoring its local states. To alleviate the monitoring burden, a periodic event detection mechanism is further developed. The exponential convergence of the dynamics with the three discrete communication schemes is proven. Finally, the comparative simulation studies are designed to illustrate the algorithm performance with different communication schemes and parameter settings. |
15,347 | Please write an abstract with title: Blind watermarking using wavelet tree quantization, and key words: Watermarking, Quantization, Frequency, Robustness, Wavelet coefficients, Data mining, Discrete cosine transforms, Copyright protection, Image coding, Streaming media. Abstract: This paper proposes a blind watermarking scheme using wavelet tree quantization. The wavelet coefficients of the host image are grouped into wavelet trees and each watermark bit is embedded using two trees. The trees are so quantized that they exhibit a large enough statistical difference, which can later be used for watermark extraction. Each watermark bit is embedded in all frequency bands, which renders the mark more resistant to attacks that remove certain frequency components. Also, the embedding is spread throughout a relatively large spatial region, which yields more robustness against spatial domain geometric attacks. Examples of various attacks are given to demonstrate the robustness of the proposed technique. |
15,348 | Please write an abstract with title: Active RC LPFs with Single-Element Pole Frequency Tuning, and key words: Tuning, Resistors, Transfer functions, Low-pass filters, Flow graphs, Cutoff frequency, Operational amplifiers. Abstract: New low-pass filter (LPF) architectures based on differential difference operational amplifiers (DDOA) are studied in this paper. The feature of the proposed LPF is that when tuning the cut-off frequency, the LPF gain remains unchanged at zero frequency. As a tuning element, it is possible to use digital potentiometers. The basic equations for two LPF modifications are presented, which provide parametric synthesis of circuits. The results of computer simulation of tunable responses were given in Micro-cap CAD. |
15,349 | Please write an abstract with title: Unsupervised segmentation of multispectral images using edge progression and cost function, and key words: Image segmentation, Multispectral imaging, Cost function, Euclidean distance, Iterative algorithms, Robustness, Military computing, Pixel, Coordinate measuring machines, Random variables. Abstract: The paper is concerned with the development of an unsupervised segmentation algorithm for multispectral images. Due to the high dimensionality of these images, the underlining motivation of this work is on how to build up a robust unsupervised segmentation algorithm with acceptable computational complexity. After an initial approximate segmentation using the EM algorithm, a cost function associated to each pixel is proposed. This function includes a term that measures how close the pixel at hand is to the region's distribution centroids, and another term that measures the local homogeneity in the pixel's neighborhood. In addition, an edge progression technique is used to re-label pixels optimally. Extensive experiments have been carried out on many multispectral images and quantitative results have shown the efficiency of the approach. |
15,350 | Please write an abstract with title: Distributed generation system planning based on renewable energy source, and key words: Renewable energy sources, Production systems, Costs, Power quality, Distributed power generation, Planning, Smart grids. Abstract: Distributed generation systems are needed in order to use existing energy resources efficiently and to meet energy needs. Although the interconnection of distributed generation systems with renewable sources offers many advantages, technical difficulties may arise from the inappropriate integration of distributed generation. Therefore, optimal planning of distributed generation is very important for the distributed grid to provide the expected power. Optimizing production systems is used to increase efficiency, provide flexibility in electrical systems, reduce costs and reduce power fluctuations. Meta-heuristic algorithms are more suitable for multi-purpose applications. In this study, the renewable energy source and energy storage system in the distributed generation system are also mentioned. Some of the optimization methods used for optimal planning of the distributed system are also included. |
15,351 | Please write an abstract with title: Feasibility Study on Interactive Geometry Sonification, and key words: Performance evaluation, Geometry, Visualization, Navigation, Optical feedback, Sonification, Haptic interfaces. Abstract: We performed a feasibility study on new ways of using sound in interactive computer graphics to improve visual interaction as well as to replace or augment haptic interaction. We considered using sound during surface interaction tasks performed with a desktop haptic device and an optical hand tracking device and evaluated the efficiency of such interactive geometry sonification in terms of its precision and speed. We also considered scenarios of using sound for easing navigation while moving along a path or surface. |
15,352 | Please write an abstract with title: Optimizing transportation for a centralized sterilization service in a multi-hospital network, and key words: Performance evaluation, Integer programming, Technology management, Medical devices, Costs, Sensitivity analysis, Hospitals. Abstract: In this paper, we deal with transportation services' configuration in the context of centralization of sterilization service for a multi-hospital network. We address the problem as a Multi-trip VRP with pickup and delivery, with time windows and release dates. The objective is to design logistics trips between the network of hospitals and the sterilization center to pick-up contaminated reusable medical devices and distribute sterile ones while minimizing the transportation costs. We propose a mixed integer programming model and provide numerical experiments on randomly generated instances. A sensitivity analysis regarding several parameters is provided and the performance of the proposed model is shown. |
15,353 | Please write an abstract with title: NGN architecture for supporting composite services, and key words: Next generation networking, Intelligent networks, Network servers, Standardization, Intserv networks, Logic, Convergence, Electronic mail, Mediation, Mobile radio mobility management. Abstract: This paper described the NGN Service Architectures proposed by some standardization organizations, for supporting complex, integrated services. Consequently, this paper proposed new NGN Service Architecture for efficiently supporting the future services like the enhanced and composite services. |
15,354 | Please write an abstract with title: Optical Communications in Japan, and key words: Optical fiber communication, Optical attenuators, Repeaters, Optical devices, Bandwidth, Optical waveguides, Coaxial cables, Power lasers, Laboratories, Telegraphy. Abstract: This paper reviews research and developmental activities in optical communications currently under way in Japan. Three major systems: 1) atmospheric optical communication systems, 2) optical-cable systems, and 3) lens-waveguide systems, using various types of lasers and newly developed optical devices and components, have been extensively studied at the Electrical Communication Laboratories of Nippon Telegraph and Telephone (NTT) and other electronic manufacturing companies in Japan. |
15,355 | Please write an abstract with title: Automatic Image Stitching for Stereo Spherical Image, and key words: Three-dimensional displays, Cameras, Image stitching, Image reconstruction, Testing. Abstract: This paper deals with automatic image stitching of two or more images using OpenCV algorithm in computing environment Python. The aim of this work was to create a new image from various input pictures, from multiple camera positions using existing method proposed by OpenCV. The main goal is to prepare algorithm for image stitching where objects are relatively close to the camera. After testing the algorithm, we pointed out some disadvantages of existing method of image stitching and proposed some adjustments for existing algorithm to achieve better results in 3D image reconstruction. |
15,356 | Please write an abstract with title: Digital Payments: Blockchain based Security Concerns and Future, and key words: Cryptocurrency, Companies, Servers, Computer science. Abstract: Technological growth has been tremendous in the past few decades and has brought significant changes in the lifestyle of human beings. One such field where the growth of technology brought a radical change is the field of transactions. Introduction of digital payments and digital money brought a whole new dimension in money payments and transactions. Policies of different governments has encouraged and also discouraged the use of various types of digital money. Still digital payments are ever growing in terms of volume. Still digital payments are not widespread as traditional cash transactions due to various security issues, threats, vulnerabilities and mostly the people's fear or doubt on its security aspects. The paper addresses such issues and finally proposes a better enhancement for the existing digital payment technologies by using secured and privacy sensitive technologies like blockchain. |
15,357 | Please write an abstract with title: Improving FM-GAN through Mixup Manifold Regularization, and key words: Manifolds, Interpolation, Adaptation models, Circuits and systems, Semisupervised learning, Generative adversarial networks, Generators. Abstract: Due to their ability to model the manifold of natural images, generative adversarial networks (GANs) have been adapted to semi-supervised learning and shown promising results. Using this property of GANs, manifold regularization has been incorporated into feature-matching GANs (FM-GAN) [14] and shown improvement over FM-GAN. In this work, we present a novel approach for performing manifold regularization in semi- supervised classification using the FM-GAN framework. Our approach, mixup manifold regularization (MUMR), regularizes the networks to favor linear behavior so that linear interpolations of noise vectors lead to linear interpolations of the associated predictions. We show that our approach is able to achieve state-of-the-art results when compared to other GANs- and perturbation-based approaches. |
15,358 | Please write an abstract with title: Effective Usage of Cognitive Computing for Designing Smart Sensing Systems and Networks in Transportation, and key words: Deep learning, Computational modeling, Oral communication, Chatbots, Sensors, Cognitive systems, Task analysis. Abstract: Thousands of people utilize public transit every day all across the world. People travel to new areas on a regular basis using public transportation, and they may feel entirely disoriented in a new environment at times. At this point, this chatbot is here to assist. A chat interface that communicates with humans. It is frequently referred to be one of the most promising technologies used for human-machine interaction. It’s a piece of software that employs deep learning methods and natural language processing (NLP) to conduct an online chat conversation via text/voice. In the form of a GUI, it offers direct communication with a conscious human agent. It is a software program that uses methods for deep learning and natural language processing (NLP) to conduct an online chat conversation via text/voice. In the form of a GUI, it offers direct communication with a conscious human agent. It analyses and extracts from the user’s inquiry the relevant database values. The cognitive Computing technique employed to these chatbots is in charge of effectively comprehending the user’s intents and avoiding any misunderstandings. The chatbots respond to the user’s query request with the most relevant response once the user’s intent is recognized. The user subsequently receives all of the info regarding the bus name as well as their figures, allowing them to comfortably go to their intended place. Proposed research makes use of much accessible Application Programming Interfaces (APIs), including the Dialog flow API for effective NLP combination with our TARS chatbot sensor. |
15,359 | Please write an abstract with title: Bearing only tracking using square root sigma point Kalman filter, and key words: Filters, Target tracking, Robustness, Filtering, Kinematics, Nonlinear equations, Frequency, Testing, Tuning, Monte Carlo methods. Abstract: The robustness and the r.m.s error settling performance of scaled square root SPKF and the same for EKF in a bearings-only-tracking are compared. While the error settling performances are comparable, the SPKF is found to be more robust, as quantified by the frequency of track loss cases in Monte Carlo simulation. A new quantitative test for track loss is introduced. The feasibility tuning the SPKF filter by utilising a design freedom is demonstrated. It is shown that the use of square root SPKF does not introduce substantial computational burden, making the SPKF a strong candidate for on board implementation. |
15,360 | Please write an abstract with title: Effect of Large Mechanical Stress on Electrical Tree Characteristics of Silicone Rubber, and key words: Electrodes, Resistance, Silicon compounds, Needles, Cable insulation, Rubber, Steel. Abstract: Silicone rubber (SIR) is widely used in the field of high-voltage cable accessories insulation due to its excellent electrical properties. However, according to statistics, in 2016 alone, there were many cable accidents at home and abroad, among which cable accessories failure accounted for 85.5%. In order to fit closely with the cable, the high-voltage cable accessories adopt the installation method of pre-expanding and maintain the expanding state in the long-term operation of the cable. The silicone rubber is deteriorated by the circumferential mechanical stress, which is easy to lead to electrical tree and finally cause breakdown fault. At present, because the steel needle electrode is easy to form gas gap with the insulating material which results in the error of electrical tree experiment under the large deformation, the research on mechanical stress is mainly focused under 30% deformation, which is far less than the actual diameter expansion ratio of 45%. In this paper, in order to approach the actual working state of the insulation material of accessories, the initial voltage and morphological characteristics of silicone rubber electrical tree under large tensile ratio of 0%, 25%, 45% and 60% were studied. In order to avoid the stress concentration at the tip of the traditional steel needle electrode, a new semi conducting needle electrode was designed and successfully manufactured, and a real-time observation system of electrical tree under power frequency was built. The results showed that the initial voltage of semi conducting needle electrode was higher than that of traditional needle electrode under the same tree initiation condition. With the increase of tensile mechanical stress, the initial voltage decreased from 15.30kV to 14.33kV, and the electrical tree tended to grow in the direction of stress application. Combined with the test results of Differential scanning calorimetry and Thermogravimetric Analysis, it can be seen that the "melting point" and the temperature of maximum thermogravimetric rate increased first and then decreased with the increase of tensile ratio. At low tensile ratio, small-scale fracture of SIR molecular chain occurred, and the amorphous region increased. At high tensile ratio, the number of broken molecular chains increased. On the whole, the physical crosslinking of silicone rubber was destroyed, some molecular segments cracked, the free volume inside the material became larger, the electrical tree was more easily induced, and the electrical tree resistance of the material decreased. |
15,361 | Please write an abstract with title: Virtual Prototyping Approach for Package Delamination Risk Assessment under Simulated High Temperature Exposure using Finite Element Analysis, and key words: Degradation, Temperature, Adhesives, Bills of materials, Thermomechanical processes, Compounds, Virtual prototyping. Abstract: Infineon is currently extending the portfolio of leadless packages platform by developing the next-gen bill of materials (BOM) which are able to withstand longer exposure to high temperatures (e.g. up to 6000 hours at 150 °C) for customer applications demanding very stringent mission profiles (e.g. 10 years of operating life). The molding compounds used to encapsulate the semiconductor devices are a mixture of inorganic fillers (usually silica) and organic resin (usually epoxy-based). The organic components will experience degradation and decomposition when exposed to elevated temperatures for an extended duration, e.g. during High Temperature Storage Life (HTSL) testing. Consequently, the thermomechanical properties (such as CTE, Tg and elastic modulus) of the mold compound will change. This results to a gradual increase in the interfacial stress between the leadframe and the molding compound, eventually leading to delamination. Performing actual HTSL test requires substantial amount of effort and time (up to 8.5 months to complete 6000 hours). Virtual prototyping approach using Finite Element Analysis (FEA) simulation offers an innovative and cost-effective alternative for delamination risk assessment by numerically evaluating the interfacial stresses in a shorter amount of time. Major benefit of this approach is: a significant reduction in engineering resources during pre-selection of materials as candidate for the next-gen BOM. This paper generally describes the observed changes in the thermomechanical properties of three different molding compound types under three different HTSL conditions by discussing the results obtained from material characterizations. The characterization results will later be translated as material inputs for the FEA simulation. The resulting interfacial stresses are then evaluated at the leadframe to different molding compound interfaces under different HTSL conditions. |
15,362 | Please write an abstract with title: Influence of construction data on the dynamics of dry-reed relays, and key words: Coils, Inductance, Digital relays, Voltage, Electromagnetic forces, Eddy currents, Radio frequency, Damping, Shape. Abstract: Analysis and the results of calculations connected with the closing process and bounces of dry reeds are presented. Dynamic properties of dry-reed relay are described by means of several dimensionless parameters. The calculation results of dynamic properties of dry-reed relays are presented in appropriate characteristics. The case of quasi-optimal control is also discussed. |
15,363 | Please write an abstract with title: TrafficPowerFlow:A Time-space Network based Program for Optimal Traffic Power Flow Analysis, and key words: Integer programming, Industrial electronics, Conferences, Vehicle routing, Power system dynamics, Transportation, Vehicle dynamics. Abstract: With transportation electrification, the power systems and traffic systems are more and more interdependent on each other. To analysis this interdependence more concisely, an optimal traffic power flow problem is formulated with the help of alternating current (AC) optimal power flow and vehicle routing problem (VPR). These two problems are integrated into an unified time-space network (TSN), as a mixed integer programming problem. To solve the meso-scale level problems with multiple oriented destination pairs, the random permuted alternating direction method of multipliers is adopted to solve the formulated problem distributed. The case study is performed on the modified IEEE-30 and Sioux fall networks, and the results verify the effectiveness of the proposed scheme. |
15,364 | Please write an abstract with title: Physical Layer Security for V2I Communications: Reflecting Surfaces Vs. Relaying, and key words: Wireless communication, Industries, Vehicle-to-infrastructure, Physical layer security, Communication system security, Security, Global communication. Abstract: Wireless vehicular network (WVN) is exponentially gaining attention from industries and researchers since it is the keystone of intelligent transportation systems (ITS). Despite the sophisticated features and services that it can offer, it is susceptible to networking attacks such as eavesdropping threats where the confidential transmitted signal could be overheard by a malicious entity. In this paper, we intend to study the physical layer security (PLS) where we consider the eavesdropping attack for vehicle-to-infrastructure (V2I) communications. We analyze the average secrecy capacity, under different scenarios by comparing the performances of employing the decode-and-forward (DF) relay, the amplify-and-forward fixed gain (AFFG) relay, and the intelligent reflecting surface (IRS). Actually, this comparison investigates the efficiency of IRS comparing to the traditional relaying systems, since it was introduced as a novel paradigm in wireless technology with highly promising potential, especially in 5G and 6G. |
15,365 | Please write an abstract with title: End-to-End Deep Multi-Modal Physiological Authentication With Smartbands, and key words: Authentication, Physiology, Biometrics (access control), Sensors, Laboratories, Deep learning, Temperature measurement. Abstract: The number of fitness tracker users increases every day. Most of the applications require authentication to protect privacy-preserving operations. Biometrics such as face images have been used widely as login tokens, but they have privacy issues. Moreover, occlusions like face masks used for COVID may reduce their effectiveness. Smartbands can track heart rate, movements, and electrodermal activities. They have been widely used for health-related applications. The use of smartbands for authentication is in the exploratory stage. Physiological signals gathered from smartbands may be used to create a multi-modal and multi-sensor authentication system. The popularity of smartbands enables us to deploy new applications without a need to buy additional hardware. In this study, we explore the multi-modal physiological biometrics with end-to-end deep learning and feature-based traditional systems. We collected multi-modal physiological data of 80 people for five days using modern smartbands. We applied a deep learning approach to the multi-modal physiological data and used feature-based traditional machine learning classifiers. The CNN-LSTM model achieved a 9.31% equal error rate and outperformed other models in terms of authentication performance. |
15,366 | Please write an abstract with title: Investigation of Environmental Reliability of Optical Polymer Waveguides Embedded on Printed Circuit Boards, and key words: Optical waveguides, Optical polymers, Printed circuits, Optical buffering, Optical refraction, Optical variables control, Temperature, Electric shock, Thermal stresses, Circuit stability. Abstract: In this paper, the effects of environmental stresses on the properties of polymer optical waveguides were studied. Optical multimode waveguides were fabricated on printed circuit boards using commercial polymers. The stability of the optical properties of the guide systems was investigated in damp heat-high humidity, high temperature storage, thermal shock and in environmental flowing multigas tests. Aging at high temperature and temperature cycling reduced the refractive index to largest extent. The optical build-up (o-BU) structure in which the optical layer was fabricated on the board surface was observed to be vulnerable under temperature shock when compared with the structure where the optical layer was laminated inside the FR4/Cu boards. The buffer layer beneath the optical build-up was found to improve the stability of the optical waveguides significantly. |
15,367 | Please write an abstract with title: A Novel AI-Based Framework for AoI-Optimal Trajectory Planning in UAV-Assisted Wireless Sensor Networks, and key words: Trajectory, Unmanned aerial vehicles, Trajectory planning, Wireless sensor networks, Data collection, Optimization, Wireless communication. Abstract: Information freshness, which is characterized by a new performance metric called age of information (AoI), significantly influences decision making in numerous applications. In wireless sensor networks, unmanned aerial vehicle (UAV) has been widely adopted for fresh data collection. The key to applying UAV lies in UAV trajectory planning. Considering several fixed waypoints in UAV trajectory, the trajectory planning is an NP-hard combinatorial optimization problem, and is difficult to solve in practice. To well balance between the accuracy and efficiency, we propose an end-to-end AI-based framework in this paper to deal with the UAV trajectory planning within two stages. First, the hover positions of UAV and data transmission time are decided using a clustering module. Then, the AoI-minimal flight path is obtained through a neural trajectory solver. Compared with classic heuristic algorithms, the proposed AI-based framework achieves a smaller AoI with two orders of magnitude lower computational time. Besides, the proposed AI-based framework can be easily generalized to larger-scale scenarios (e.g., up to 2,000 sensor nodes) which cannot be solved by exact algorithms (e.g., dynamic programming) in a limited time. Moreover, the AI-based framework is comparable in accuracy with the commercial open-source solver Google OR-tools, but the efficiency is increased by 200%. |
15,368 | Please write an abstract with title: Low power low phase noise 3.9GHz SiGe VCO with data modulation correction loop, and key words: Phase noise, Silicon germanium, Germanium silicon alloys, Voltage-controlled oscillators, Phase modulation, Inductors, Varactors, Circuit optimization, Transceivers, Spirals. Abstract: A 3.9 GHz LC VCO is fabricated using a 0.35 /spl mu/m SiGe BiCMOS process. The VCO is modulated through a modulation port in transmit mode. The VCO utilizes a modulation correction loop to compensate the modulation deviation due to the variation in the tuning circuit. The VCO measured phase noise is -140 dBc at 8 MHz offset, while draining 4 mA from a 2.5 V regulated supply. A 25% tuning range was also measured. |
15,369 | Please write an abstract with title: Reliability of a Physical System, and key words: Reliability theory, Electronic equipment, Graph theory, Constraint optimization, Constraint theory, Weapons, Probabilistic logic, Flow graphs, Costs, Probability. Abstract: This paper presents the general concept of the reliability of a complex physical system which consists of a number of unreliable components. Such a system may be analyzed systematically by means of algebraic and topological theory. Various properties concerning the system reliability are established. A numerical procedure for finding the necessary topological quantities is developed to facilitate computations. The optimization of the reliability of the basic system under given restricted conditions can be accomplished by the application of the theory described. |
15,370 | Please write an abstract with title: ESD-Performance Enhancement of Circular Ultra-High-Voltage 300-V N-Channel Lateral-Diffused MOSFETs by Source/Drain Embedded Schottky Diodes, and key words: Schottky diodes, Electrostatic discharges, Layout, Breakdown voltage, Electrodes, Equivalent circuits, Testing. Abstract: This study with the area-efficient design for improving electrostatic discharge (ESD) and Latch-up (LU) abilities in the ultra-high voltage (UHV) n-channel Lateral-Diffused MOSFET (nLDMOS) is investigated via a TSMC 0.5-μm UHV Bipolar CMOS DMOS (BCD) process. There are two architectures of these nLDMOS devices with embedded Schottky diodes in the electrode area. Firstly, the drain side is divided into three concentric circles and embedded with Schottky diodes. The influence of these samples with different layout arrangements on ESD is evaluated. For the second item, UHV nLDMOS devices with the source side embedded Schottky diodes by two alternative layout types are developed. Experimental results showed that an UHV nLDMOS with embedded Schottky diodes at the drain side can significantly improve ESD ability, especially for the fully embedded Schottky diodes at the drain side (being with the highest figure of merit (FOM) value in the ESD, LU, and cell-area considerations). On the other hand, with embedded Schottky diodes at the source side can increase the holding voltage which can effectively improve the LU immunity. |
15,371 | Please write an abstract with title: Teaching About Metamaterials and Nanotechnologies, and key words: Education, Valves, Metamaterials, Telecommunications, Nanobioscience, Biosensors, Task analysis. Abstract: In the beginning of the XXI century, new advances in technology allowed for the manufacturing of new materials which allowed for new developments in areas as diverse as information and telecommunications, biology, medicine, industry and Defense. It is a multidisciplinary field where contributions from physics chemistry, material science and electronics converge. In Electrical and Information Engineering the teaching of these new subjects is mandatory in order to keep in pace with the industrial developments and contributing to an effective scientifically sound professional formation. Teaching these new concepts however, clashes sometimes with the classical approach, used in the standard curricula.In this paper we describe the challenges presented by the teaching of these subjects applied to metamaterials. Metamaterials are non-natural materials constituted by a substrate with inclusions distributed with a spatial periodicity lower than the wavelength of the incident radiation. They present a macroscopical behavior which can be described classically by the constitutive parameters ε and μ. These materials which date from the beginning of the XXI century are of paramount importance for several applications, namely antennas, lenses and invisibility cloaks, which will change the paradigm of many areas, especially in Security and Defense. |
15,372 | Please write an abstract with title: Design of a Microcontroller-Based Heating System Controller Using Fuzzy Logic, and key words: Heating systems, Temperature sensors, Fuzzy logic, Air conditioning, Temperature distribution, Technological innovation, Microcontrollers. Abstract: Heating, Ventilation and Air Conditioning systems provide heating and cooling requirement for human health as well as optimal conditions for the quality of life. They are the essential consumer of energy in buildings. There is a growing interest in improved control of such systems and reduction of energy consumption. In addition to not providing required comfort, convenience control systems are also away keeping energy efficiency. In this paper, a fuzzy logic-based control system has been investigated for realizing a low-cost heating system for efficient energy constraints and comfortable heat distribution. The fuzzy logic approach allows to provide the appropriate temperature and comfortable heat distribution with low energy requirements. The proposed system has two temperature inputs and two outputs as heater level and vane angle. From the outputs of the system, basically heater level is controlled by considering minimum temperature and angle is controlled by considering temperature difference value read from the sensors, respectively. By using LabVIEW Fuzzy System Designer, control rules are formed and simulated. The system is implemented with an Arduino Mega based microcontroller embedded system and tested for various operating conditions. Simulations performed and the experimental results show the superiority of such controller. |
15,373 | Please write an abstract with title: Low-Loss Impedance-Matched Sub-25-μm Vias in 3-D Millimeter-Wave Packages, and key words: Resistance, Substrates, Routing, Impedance, 5G mobile communication, Antenna arrays, Packaging. Abstract: This article presents, for the first time, low-loss small microvias in build-up layers for the next-generation highdensity high-performance fifth-generation (5G) millimeter-wave (mm-wave) antenna-integrated packages. As the operating frequency increases, the signal losses in antenna packages become more critical and need to be mitigated to obtain desired performance in beamforming and massive multi-input multioutput. As electrical wavelengths in mm-wave spectra are short, the signal losses caused by microvias dominate the loss budget. To minimize the signal losses and identify the required microvia diameter in build-up layers, this article first focuses on the modeling of small microvias for impedance matching. Based on the models and simulated characteristic impedance, test vehicles with daisy chains are fabricated in build-up layers on a core package substrate. Ultraviolet (UV) laser is utilized to drill microvias, and targeted microvia diameters are obtained through a semiadditive patterning process. High-frequency measurements are also performed to correlate with the models and simulated results in the 28-GHz band. The characterization results exhibit good model-to-hardware correlation and indicate that small microvias (20 μm) provide impedance closer to 50 Ω compared with the larger microvias. This matched microvia impedance lowers reflection and insertion loss, resulting in a 10% reduction in the signal losses caused by microvias in the 5G New-Radio n257 band around 28 GHz. |
15,374 | Please write an abstract with title: Steady-state bumpless transfer under controller uncertainty using the state/output feedback topology, and key words: Steady-state, Closed loop systems, Uncertainty, Output feedback, Topology, Pressure control, Convergence, Industrial control, Error correction, MIMO. Abstract: Linear quadratic (LQ) bumpless transfer design introduced recently by Turner and Walker gives a very convenient and straightforward computational procedure for the steady-state bumpless transfer operator synthesis. It is, however, found to be incapable of providing convergence of the output of the offline controller to that of the online controller in several industrial applications, producing bumps in the plant output in the wake of controller transfer. An examination of this phenomenon reveals that the applications in question are characterized by a significant mismatch, further referred to as controller uncertainty, between the dynamics of the implemented controllers and their models used in the transfer operator computation. To address this problem, while retaining the convenience of the Turner and Walker design, a novel state/output feedback bumpless transfer topology is introduced that employs the nominal state of the offline controller and, through the use of an additional controller/model mismatch compensator, also the offline controller output. A corresponding steady-state bumpless transfer design procedure along with the supporting theory is developed for a large class of systems. The new technique is shown to be capable of eliminating the online/offline controller output tracking errors under significant controller uncertainty, while preserving fast convergence of Turner and Walker design. Due to these features, it is demonstrated to solve a long-standing problem of high-quality steady-state bumpless transfer from the industry standard low-order nonlinear multiloop PID-based controllers to the modern multiinput-multioutput (MIMO) robust controllers in the megawatt/throttle pressure control of a typical coal-fired boiler/turbine unit. |
15,375 | Please write an abstract with title: An Algorithm for Mining Track Law Based on Adaptive Clustering, and key words: Target tracking, Conferences, Fitting, Clustering algorithms, Interference, Trajectory, Data mining. Abstract: In many sailing trajectories, the curve can be approximated, and the target often has a certain law of activity. So how to use unsupervised learning to mine the law of the target trajectory in the route is of great significance to situational awareness. More importantly, the law of the mining activity should be suitable for different scenarios, so the adaptiveness of the target trajectory mining algorithm should be considered. In this regard, firstly, it is based on the distance formula between the vectors to consider the similarity between the tracks, and the multi-dimensional distance calculation method is used to calculate the distance relationship between the tracks. The multi-dimensional calculation method uses longitude, latitude, altitude, and speed. The distance calculation method of attributes such as, heading, etc. under different influence factors, and then use the improved density-based clustering algorithm to mine the law of the route, and finally display the mined fitting track in the interface to represent the characteristic track. The experimental results show that the mining effect of the adaptive clustering mining algorithm is better than the fixed value of the parameters. The track accuracy and recall rate that can be mined by the adaptive method are significantly higher than the previous algorithms, and it can be extended to different scenarios. |
15,376 | Please write an abstract with title: New Approach for Indoor Positioning With Wi-Fi Using Quadratic Antenna Arrays, and key words: Microstrip antenna arrays, Linear antenna arrays, Phased arrays, Antenna feeds, Microstrip antennas, Microstrip, IP networks. Abstract: This letter provides a versatile solution for indoor positioning systems (IPS). Existing IPS designs are either accurate but complicated, or simple yet not accurate. All of the available solutions solely target positioning. In this letter, a novel idea is proposed as a proof of concept, which can be augmented in the IEEE 802.11 standards. The proposed concept offers adjustable positioning accuracy, along with the provision of networking. It is based on designing two steering quadratic phased antenna arrays providing two orthogonal footprints intersecting at the location of interest. With a distinct service set identifier (SSID) associated with each footprint, determining the position becomes straightforward. Some scenarios are possible for maintaining the communication aspects of the IEEE 802.11. Two quadratic microstrip antenna arrays and two feeding circuits with phase shifters are used to achieve the steer. The letter includes the RF design, simulation and analysis for further illustration. |
15,377 | Please write an abstract with title: From traditional to home-confined learning: a case study in a school involved with ICT, and key words: COVID-19, Uncertainty, Pandemics, Statistical analysis, Measurement uncertainty, Switches, Vocational training. Abstract: The SARS-CoV-2 pandemic affected all aspects of daily life overnight, worldwide. In education, academic systems had to frantically switch to an online format. Teachers and students had to face an unknown situation, with difficulties as isolation, technology management and pedagogical approaches. However, this impact can be drastically reduced for schools with strong previous background in information and communication technologies (ICT). We reached this conclusion by objectively quantifying the learning results in a sudden transition from face-to-face (F2F) to distant learning (DL). We focus on the abrupt home confinement experienced by the Maristak Durango school during the COVID-19 outbreak. As revealed by the statistical analysis related to the grades of the 360+ students (VET, High School) who went through this F2F to DL transition (F2F2DL), almost all students were able to retain and improve their grades. The results prove how a good ICT-based background can tangibly alleviate any radical F2F2DL shift brought by an unforeseen chain of events. This paper contributes to this type of analysis for VET, since there are hardly any studies related to this scenario. |
15,378 | Please write an abstract with title: One Class Support Vector Machine Active Learning Method for Unbalanced Data, and key words: Support vector machines, Learning systems, Machine learning algorithms, Distributed databases, Machine learning, Predictive models, Knowledge discovery. Abstract: Active learning is an important method to efficiently reduce the labeled sample size in large-scale machine learning. As the large amount of data presents the nature of imbalance, the study of active learning methods for corresponding unbalanced datasets highlights important practical significance. There is a problem with the current algorithm. The initialization of active learning becomes difficult with the increase of the unbalanced degree, which causes more labels waste. This paper proposes a one-class support vector machine active learning (OCSVM-AL) method for this problem. Firstly, we obtain the structure information of the sample set by k-means clustering. Then, the OCSVM-AL is used on each cluster. For each cluster, OCSVM-AL iteratively marks the sample from the cluster and adds the marked sample to the marked sample pool. A one-class support vector machine model is trained by using majority class samples in the marked sample pool. The trained model is used to predict the unlabeled samples in this cluster, and the labels of unlabeled samples is obtained. By the results of each cluster, all sample labels are obtained. Simulation experiments proved that this method is an effective active learning method and can significantly reduce the labeled sample size. |
15,379 | Please write an abstract with title: Robust Detection of Electricity Theft Against Evasion Attacks in Smart Grids, and key words: Degradation, Deep learning, Energy consumption, Perturbation methods, Simulation, Detectors, Benchmark testing. Abstract: Electricity theft cyber-attacks pose significant threats to smart power grids. In these attacks, malicious customers hack into their smart meters and manipulate the integrity of their energy consumption readings to reduce their electricity bills. Recently, machine learning techniques have been successfully employed to detect such cyber-attacks. However, the developed detectors have been tested against simple attacks. In this paper, we investigate the performance of electricity theft detectors against evasion attacks that are designed to reduce the reported value of the energy consumption and at the same time fool the machine learning-based detector model via adversarial samples. Furthermore, we propose a strong evasion attack that significantly degrades the performance of a set of benchmark detectors. Our results reveal that evasion attacks can deteriorate the detection rate (DR) and false alarm (FA) rate by ~ 20%. To address such evasion attacks, we propose an ensemble learning-based detector that integrates auto-encoder with attention (AEA), long-short-term-memory (LSTM), and feed forward deep neural networks. The developed detector maintains a stable detection performance against evasion attacks with a deterioration in performance by only 1 − 5% in DR and FA. |
15,380 | Please write an abstract with title: A lamination technique of LCP/Cu for electronic packaging, and key words: Lamination, Electronics packaging, Bonding, Rough surfaces, Surface roughness, Surface cleaning, Crystallization, Liquid crystal polymers, Electronic circuits, Mechanical factors. Abstract: Liquid crystalline polymer (LCP) is expected to be used for the lamination of electronic circuit boards because of its excellent mechanical and electric properties, such as a low dielectric constant and dimensional stability. However, it has not been widely used yet due to the weak interaction between LCP and Cu. Roughened surfaces of Cu foil that could deteriorate the electrical property are being used in conventional lamination process in order to improve the bonding strength. Surface activated bonding (SAB) of Cu/LCP based on a surface cleaning process by physical bombardment in vacuum has been performed to achieve the strong bonding. A peel strength of 800/spl sim/900 g/cm of the laminate prepared by SAB process is achieved, and the surface roughness of the interface between LCP and Cu is controlled to be less than 100 nm. In this experiment, additional treatment including Cu deposition on LCP and annealing after bonding is applied in order to obtain strong bonding. The effects of these treatments are investigated with the discussion of bonding mechanism. |
15,381 | Please write an abstract with title: Accelerated Stress Tests and Statistical Reliability Analysis of Metal-Oxide/GaN Nanostructured Sensor Devices, and key words: Stress, Reliability, Life estimation, Acceleration, Performance evaluation, Signal to noise ratio, Gallium nitride. Abstract: In this work, sensor die/process and packaging reliabilities of metal-oxide/GaN nanowire-based gas sensors have been studied for the first time, using industry standard accelerated lifetime tests, such as- High Temperature Operating Life, High Temperature Storage Life, Temperature Cycling Test and Highly Accelerated Stress Test. The metal-oxide functionalization used for sensing ethanol exposure in this study is ZnO. For all the tests, sample ZnO/GaN devices have been exposed to 500 ppm of ethanol in dry air at room temperature (20°C) to observe and record the degradation of signal to noise ratio (SNR) as a function of stress time and number of thermal cycles. Although no complete device failure was observed in any of the performed tests, gas sensing response kept decreasing gradually due to increasing stress. The lowering of the sensor response is believed to be due to gradual phase transformation of the receptor ZnO and baseline resistance increase. The method for estimating failure rate and lifetime of sensor devices has been discussed in detail. Using statistical data from the performed accelerated stress tests, chi-square distribution has been implemented to predict the failure rate and lifetime of GaN nanostructured sensor devices. The mean-time-to-failure (MTTF) of the stressed devices of this study is about 4 years. |
15,382 | Please write an abstract with title: A Coarse-to-Fine Bilevel Adversarial Domain Adaptation Method for Fault Diagnosis of Rolling Bearings, and key words: Fault diagnosis, Vibrations, Rolling bearings, Adaptation models, Training, Task analysis, Pattern recognition. Abstract: Recently, domain adaptation (DA) has been used to solve the fault diagnosis problem in rolling bearings. However, most of the existing methods only align the distribution of domains and ignore the fine-grained information of the same fault categories in different domains, which leads to the degradation of diagnostic performance. To address such domain difference issues, this article proposes a novel coarse-to-fine bilevel adversarial DA approach (C2FADA) for bearings fault diagnosis. First, a sparse autoencoder (SAE) is used to extract features from raw data (containing both the source and target domains), and a Kullback–Leibler (KL) divergence term is then introduced to measure the discrepancy between the features from the source domain and the target domain. Second, a bilevel adversarial module is established to gradually align different domains at the domain level (with a coarse-grained model) and the class level (with a fine-grained approach) to tackle the domain shift issue and enable the classifier to learn the domain invariant representation features. Third, a spectral norm regularization constraint term is introduced to improve the stability of the adversarial training process by mitigating the effect of adversarial perturbations. The results show that the classification performance of the proposed C2FADA method is better than the compared existing peer methods. |
15,383 | Please write an abstract with title: A defect detection method of gear end-face based on modified YOLO-V3, and key words: Gears, Convolution, Feature extraction, Surface treatment, Brightness, Conferences, Real-time systems. Abstract: Due to the continuous improvement of gear machining quality requirements, the detection of gear face defects has been paid more attention. The traditional sampling method based on artificial experience has been unable to meet the detection needs of manufacturing enterprises. Manufacturing enterprises urgently need an accurate, fast and low-cost detection method. Due to the small surface defects of gear end-face, the complex shape of the gear end-face, the complex processing environment in the workshop and the high requirements of real-time detection, there are great challenges in the detection of gear end-face defects. Therefore, this paper proposes a method for gear end-face defect detection based on improved YOLO-V3. Firstly, this paper proposed a gear image preprocessing method based on gray histogram, it's used to eliminate the unfavorable and unobvious defects caused by the workshop processing environment and non-machined areas. Then, based on the newly designed feature extraction backbone network DWPW-ResNet34 that takes into account both accuracy and efficiency, an improved YOLO-V3 defect detection network is proposed to realize the real-time detection of metal gear end-face defects in the production process. |
15,384 | Please write an abstract with title: Digital Cultural Heritage Twins, a Proposal and Some Examples, and key words: Knowledge representation, Digital twins, Cultural differences, Proposals. Abstract: We propose here to consider the digitalized image of a CH entity as the association of two components, the first describing the physical properties of the entity, and the second its immaterial/symbolic aspects under the form of a “Digital Cultural Heritage Twin”. NKRL, the Narrative Knowledge Representation Language, has been chosen for the implementation of the Digital CH Twins components; some detailed examples of its use are given in the paper. |
15,385 | Please write an abstract with title: Periodic motion in nonlinear systems, and key words: Nonlinear systems, Feedback, Linear systems, Sufficient conditions, Forward contracts, Transfer functions, Stability, Australia, Geometry, Frequency response. Abstract: In this paper it is shown how some basic ideas from system theory and differential geometry can be used to establish some new results on the existence of periodic motion in automomous feedback systems. The conditions are expressed in terms of the frequency response characteristic of the open-loop system and certain general properties of the non-linearities. |
15,386 | Please write an abstract with title: Modulated Reactance Surfaces With Several Modulation Indices for Multibeam Leaky-Wave Antenna Design, and key words: Surface waves, Surface impedance, Dispersion, Impedance, Frequency modulation, Antennas. Abstract: A general formulation describing a multitone periodicity of reactance surfaces is investigated, assuming a 1-D periodicity along the surface, while the surface periodicity is composed of several modulation indices. The dispersion analysis of the wave guided by artificial reactance surfaces is theoretically studied based on Floquet's theorem, and then, rigorous results are obtained for the two-tone modulated reactance surfaces (MRSs). Using n = -2 and n = -3 space harmonics (Sits) in a two-tone MRS, a novel planar leaky-wave antenna (LWA) composed of a transverse magnetic (TM) surface wave source and a two-tone MRS is proposed to achieve double-beam radiation. At the design frequency of 14 Gitz, the suggested antenna is simulated and then manufactured. It is observed that the theoretical analysis of the radiation power and beam angles of the fast Sits have good agreement with the simulation results and measurements. |
15,387 | Please write an abstract with title: Location-dependent Task Assignment for Opportunistic Mobile Crowdsensing, and key words: Task analysis, Sensors, Crowdsensing, Protocols, Social networking (online), Performance evaluation. Abstract: In mobile crowdsensing applications that rely on opportunistic sensing and communication, efficient task assignment strategies are needed to ensure that the tasks are completed before their expiration time. This requires to optimize the tradeoff between high task completion ratio and cost-efficiency by assigning tasks only to a small group of users who are expected to be of most assistance to task owners. To address this issue, in this paper, we propose two new task assignment protocols based on a new metric that accurately measures the utility of users to each other in performing tasks in specific regions. Through simulations we show that the proposed protocols not only provide a high task completion ratio, but also utilize the network resources efficiently by assigning tasks to as few users as possible, hence they perform better than the previous work. |
15,388 | Please write an abstract with title: False Data Injection Cyber Range of Modernized Substation System, and key words: Substations, Smart grids, Temperature measurement, Temperature sensors, Power measurement, Software, Frequency measurement. Abstract: The extensive deployment of information and communication technologies in modern power grid makes the grid more vulnerable to cyber attacks, resulting in threats to the economy, social stability and sometimes human lives. While it is necessary to deploy cybersecurity measures to counter such threats, evaluation of the effectiveness and negative impact of the cybersecurity solutions through extensive experiments is challenging. For instance, it is often very restricted or even impossible to conduct experiments directly on the operating physical systems as the interruption of those critical systems will incur significant financial losses. In this paper, we discuss components and configurations that are necessary to implement a cyber range, a virtual environment for cybersecurity evaluation and experimentation, for emerging false data injection attacks against the smart grid. We also discuss the proof-of-concept implementation using open-source software and discuss case studies of attacks against modernized substation systems. |
15,389 | Please write an abstract with title: Power flow and stability models for induction generators used in wind turbines, and key words: Load flow, Induction generators, Wind turbines, Wind energy, Reactive power, Power system modeling, Stators, Induction machines, Power system stability, Power system transients. Abstract: Model initialization of the induction generator for the wind power generation is investigated. Incorrect initialization may lead to numerical instability problems, not to mention erroneous result from dynamic simulation. The machine model is studied from the perspective of slip and reactive power calculation and tested for various cases. The dynamic reactive power calculation in well-know software package is discussed and the deviation of dynamic reactive power from the steady state reactive power is highlighted. |
15,390 | Please write an abstract with title: Principal component analysis for online handwritten character recognition, and key words: Principal component analysis, Character recognition, Smoothing methods, Feature extraction, Low pass filters, Training data, Handwriting recognition, Pattern classification, Noise reduction, Low-frequency noise. Abstract: In this paper, principal component analysis (PCA) is applied to the problem of online handwritten character recognition in the Tamil script. The input is a temporally ordered sequence of (x,y) pen coordinates corresponding to an isolated character obtained from a digitizer. The input is converted into a feature vector of constant dimensions following smoothing and normalization. PCA is used to find the basis vectors of each class subspace and the orthogonal distance to the subspaces used for classification. Pre-clustering of the training data and modification of distance measure are explored to overcome some common problems in the traditional subspace method, in empirical evaluation, these PCA -based classification schemes are found to compare favorably with nearest neighbour classification. |
15,391 | Please write an abstract with title: What Makes Transfer Learning Work for Medical Images: Feature Reuse & Other Factors, and key words: Deep learning, Microscopy, Microprocessors, Transfer learning, Computer architecture, Data models, Pattern recognition. Abstract: Transfer learning is a standard technique to transfer knowledge from one domain to another. For applications in medical imaging, transfer from ImageNet has become the de-facto approach, despite differences in the tasks and im-age characteristics between the domains. However, it is un-clear what factors determine whether - and to what extent- transfer learning to the medical domain is useful. The long- standing assumption that features from the source domain get reused has recently been called into question. Through a series of experiments on several medical image bench-mark datasets, we explore the relationship between transfer learning, data size, the capacity and inductive bias of the model, as well as the distance between the source and tar-get domain. Our findings suggest that transfer learning is beneficial in most cases, and we characterize the important role feature reuse plays in its success. |
15,392 | Please write an abstract with title: Reducing spatial interference in robot teams by local-investment aggression, and key words: Interference, Orbital robotics, Robot sensing systems, Investments, Displays, Centralized control, Transportation, System performance, Sensor phenomena and characterization, Computational modeling. Abstract: This paper extends and improves upon our previous work on the use of stereotypical aggressive display behavior to reduce interference in robot teams, and thus improve their overall efficiency. We examine a team of robots with no centralized control performing a transportation task in which robots frequently interfere with each other. The robots must work in the same space, so territorial methods are not appropriate. In our method, when robots come into competition for floor space, each selects an aggression level and the competition is resolved in favor of the more aggressive robot. Our recent work showed that choosing aggression proportional to task investment can produce better overall system performance compared to aggression chosen at random. This paper describes a new technique, local investment, for computing an aggression level that performs better than any previous method and relies only on local sensor data. The method is evaluated in a simulation study, and is then shown to be effective in a real-world robot implementation. |
15,393 | Please write an abstract with title: Experimental Understanding of the Impact of Channel Percolation on Low Frequency Noise Using Transient Enhanced Diffusion of Channel Dopants, and key words: Low-frequency noise, Manufacturing, Transient analysis, MOS devices. Abstract: This paper investigates the impact of channel percolation on low frequency noise (LFN). Using transient enhanced diffusion (TED) of channel dopants, the degree of channel percolation was changed. It was demonstrated that LFN in low drain current region was degraded by enhanced channel percolation induced by TED of channel dopants. |
15,394 | Please write an abstract with title: A Coarse-to-Fine Approach for Urban Land Use Mapping Based on Multisource Geospatial Data, and key words: Roads, Urban areas, Geospatial analysis, Sensors, Planning, Remote sensing. Abstract: Timely and accurate land use mapping is a long-standing problem, which is critical for effective land and space planning and management. Due to complex and mixed use, it is challenging for accurate land use mapping from widely-used remote sensing images (RSI) directly, especially for high-density cities. To address this issue, in this paper, we propose a coarse-to-fine machine learning-based approach for parcel-level urban land use mapping, integrating multisource geospatial data, including RSI, points-of-interest (POI), and areas-of-interest (AOI) data. Specifically, we first divide the city into built-up and non-built-up regions based on parcels generated from road networks. Then, we adopt different classification strategies for parcels in different regions, and finally combine the classified results into an integrated land use map. The results show that the proposed approach can significantly outperform baseline method that mixes built-up and non-built-up regions, with accuracy increase of 250% and 30% for level-1 and level-2 classification, respectively. In addition, we examine the rarely explored AOI data, which can further boost the level-1 and level-2 classification accuracy by 13% and 14%. These results demonstrate the effectiveness of the proposed approach and also indicate the usefulness of AOIs for land use mapping, which are valuable for further studies. |
15,395 | Please write an abstract with title: Real-time Measurement and Prediction of Ball Trajectory for Ping-pong Robot, and key words: Cameras, Robot vision systems, Trajectory, Machine vision, Robots, Robot kinematics, Three-dimensional displays. Abstract: This paper develops a vision system to predict ball trajectory for the ping-pong robot. The stereo vision system with two cameras is used to measure ball center. A multi threshold segmentation algorithm is applied to precisely locate the center of ball in image and the triangulation algorithm is applied to compute the 3D position in the world coordinates. Six consecutive coordinates are collected and the least squares method is used to determine the initial states of the ball. From these initial states, the following flight trajectory of the ball is predicted using two physical models: aerodynamics model and rebound model. Then the states of the ball at striking point are calculated from the predicted trajectory. Experimental results show that the developed system can achieve a good predicting precision in real-time. |
15,396 | Please write an abstract with title: Porting Applications to Arm-based Processors, and key words: Program processors, Instruction sets, Memory management, Bandwidth, Servers, Stress, Optimization. Abstract: Arm-based server processors are becoming increasingly used for building massively parallel HPC systems. This triggers the need for porting HPC applications to such architectures and to collect more knowledge about performance benefits and challenges. In this contribution, we report on experiences made during our ongoing efforts to port applications to Arm-based platforms at the Jülich Supercomputing Centre (JSC). The performance of these applications is explored on different Arm-based node architectures plus an x86-based architecture for reference. |
15,397 | Please write an abstract with title: Imbalance-Tolerant Bit-Line Sense Amplifier for Dummy-Less Open Bit-Line Scheme in DRAM, and key words: Sensors, Capacitance, MOS devices, Latches, Computer architecture, Microprocessors, Random access memory. Abstract: In a conventional open bit-line scheme of DRAM, the edge subarrays (MATs) located at both ends of the cell array block contain alternated real and dummy bit-lines, unavoidably leading to an additional area overhead. To reduce the area overhead, one edge MAT can be eliminated by converting the dummy bit-lines of the other edge MAT into real bit-lines. This strategy causes the conventional bit-line sense amplifiers (BLSAs) in the MATs located at both ends of the cell array block to have a much smaller complementary bit-line capacitance than a true bit-line capacitance. Thus, the sensing operation of a conventional BLSA with this unbalanced bit-line capacitance experiences various problems: sensing voltage decrease, data flipping, and asymmetric equalization. To solve these problems, we propose a novel sensing circuit that can operate effectively even under unbalanced bit-line capacitance, thus suggesting the possibility of an open bit-line scheme without dummy bit-lines. Our proposed dummy-less open bit-line scheme can save approximately 4% of the array height. Compared with the conventional unbalanced BLSA, the proposed BLSA increases the sensing voltage by more than 100%, reduces the voltage peaks by 30% during the data transfer, and reduces equalization time by 1.2 ns in HSPICE Monte Carlo simulation. |
15,398 | Please write an abstract with title: Application Study of UAV and IOT Technology in Intelligent Detection of Bridge Engineering, and key words: Bridges, Wireless communication, Road transportation, Wireless sensor networks, Technological innovation, Machine learning, Logic gates. Abstract: The ministry of transport officially released the implementation plan for the construction of highway long- span bridge structural health monitoring system on march 1, 2021, which is doomed to promote the popularization and application of bridge structure health monitoring. This paper innovatively combines UAV(Unmanned Aerial Vehicle) and IOT(Internet of Things) technology, and carries out practical engineering application in bridge quality detection project. Firstly, based on the research status of bridge health monitoring, the design principles, reference laws and code of intelligent bridge inspection system are sorted out, and a three-layer intelligent bridge detection system based on IOT is designed. The main components include low-power consumption wireless sensor, edge data acquisition device, gateway and health big data analysis center. This paper focuses on the practical application of UAV and IOT technology in intelligent detection of bridge engineering. The innovations include targeted deployment and monitoring of various types of sensors according to the actual bridge structure and on-site conditions, as well as targeted design of UAV flight routing and important detection sites. Finally, this paper discusses the research status of bridge structural damage identification and health status assessment. Although some progress has been made, there are still many difficulties to be overcome for practical engineering applications. Through the introduction of the above practical engineering application cases, it is hoped to provide some guidance for the research of bridge health monitoring and intelligent detection. |
15,399 | Please write an abstract with title: Modified progressive phasing for endfire arrays, and key words: Phased arrays, Senior members, Antenna arrays, Antenna radiation patterns, Geometry, Delay, Antennas and propagation. Abstract: The general problem of modifying antenna array patterns by adjusting only the phase of the elements is discussed. It is shown that, in the case of endfire arrays, considerable reduction of the sidelobe levels can be obtained by using small departures from progressive phasing. Simple formulas for the required phasing are derived. An alternative method, using only a single pair of "sidelobe-reducing" elements, is also given. |
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