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8,100 | Please write an abstract with title: Line-of-Sight Probability for mmWave-Based UAV Communications in 3D Urban Grid Deployments, and key words: Buildings, 3GPP, Mathematical model, Analytical models, Urban areas, Unmanned aerial vehicles, Three-dimensional displays. Abstract: The network operators will soon be accommodating a new type of users: unmanned aerial vehicles (UAVs). 5G New Radio (NR) technology operating in the millimeter-wave (mmWave) frequency bands can support the emerging bandwidth-hungry applications facilitated by such aerial devices. To reliably integrate UAVs into the NR-based network infrastructure, new system models that capture the features of UAVs in urban environments are required. As city building blocks constitute one of the primary sources of blockage on the links from the UAV to its serving base station (BS), the corresponding line-of-sight (LoS) probability models are essential for accurate performance evaluation in realistic scenarios. We propose a LoS probability model in UAV communication setups over regular urban grid deployments, which is based on a Manhattan Poisson line process. Our approach captures different building height distributions as well as their dimensions and densities. Under certain characteristic distributions, closed-form expressions for the LoS probability are offered. Our numerical results demonstrate the importance of accounting for the building height distribution type as well as the orientation of the UAV with respect to its BS. By comparing our model with the standard ITU and 3GPP formulations, we establish that the latter provide an overly optimistic approximation for various deployments. |
8,101 | Please write an abstract with title: An implementation of evolutionary computation for path planning of cooperative mobile robots, and key words: Evolutionary computation, Path planning, Mobile robots, Traveling salesman problems, Orbital robotics, Genetic engineering, Cities and towns, Genetic algorithms, Analytical models, Circuits. Abstract: This article describes how to apply a genetic algorithm in finding a globally sub-optimal path for the robot group working under certain tasks. Path planning is an important problem in robotics. With the development of cooperative robotics in recent years, the problem of path planning for a robot group is receiving more and more attention and interest. In this paper, the problem of path planning for a robot group is formalized as a multiple travelling salesman problem (MTSP) that employed either total-path-shortest or longest-path-shortest as the evaluating criterion. Longest-path-shortest MTSP has never been studied before. The formalized models of the two kinds of multiple travelling salesman problem are presented in this paper, and the main idea and specific way of applying the genetic algorithm in solving the two kinds of travelling salesman problem or their admixture are also amply discussed in this paper. At the end the convergence analysis and the simulation are discussed, as the simulation result shows, it is an effective and robust way of solving the problem of path planning for a robot group. |
8,102 | Please write an abstract with title: On Optimal Power Control for Sequential NOMA in Wireless Relay Networks, and key words: Wireless communication, NOMA, Base stations, Vehicular and wireless technologies, Power demand, Spectral efficiency, Simulation. Abstract: In this paper, we study optimal power control for sequential NOMA in wireless relay networks. When a sequential NOMA scheme is used, in each time slot, the base station uses NOMA in the first phase, while the stronger relay uses NOMA in the second phase. To solve the problem of optimal power control for sequential NOMA, we design the geometric eight-point algorithm based on geometric properties of the non-convex optimization problem. Specifically, the proposed geometric eight-point algorithm adopts parabolas and the geometric classification algorithm to obtain a locally optimal power allocation vector with low computational complexity. Simulation results indicate that the proposed sequential NOMA scheme could increase the spectral efficiency and reduce the relay power consumption for wireless relay networks. |
8,103 | Please write an abstract with title: High Dimensional Feature Selection Method of Dual Gbest Based on PSO, and key words: Feature extraction, Filtering algorithms, Particle swarm optimization, Classification algorithms, Sociology, Statistics, Optimization. Abstract: Particle swarm optimization (PSO) has a bright future in feature selection (FS). However, with the increase of data set dimension, the search space becomes larger, PSO is easy to fall into local optima and brings a lot of time and space overhead. It is still a big challenge to apply PSO to thousands of feature data sets. In this paper, the features are reordered to ensure that the shorter particles can get better classification performance. We propose a subset length constraint mechanism to reduce the number of selected features of particles gradually, so as to introduce particles into smaller and more effective space and jump out of local optima. Although the short running time of filter FS is more suitable for high-dimensional feature selection, the classification accuracy of filter FS is generally lower than that of wrapper FS. In order to achieve better classification performance in a short time, we propose a dual global optimal (Gbest) updating model. PSO has been modified. Compared with six algorithms on six high-dimensional data sets. The results show that the new dual Gbest update mechanism based on length restriction mechanism has higher efficiency and accuracy. |
8,104 | Please write an abstract with title: National Geospatial-Intelligence Agency Academic Research Program, and key words: Educational institutions, Research initiatives, Proposals, Intelligent systems, Educational programs, Terrorism. Abstract: "Know the Earth... Show the Way". In fulfillment of its vision, the National Geospatial-Intelligence Agency (NGA) provides geospatial intelligence in all its forms and from whatever source - imagery, imagery intelligence, and geospatial data and information - to ensure the knowledge foundation for planning, decision, and action. To achieve this, NGA conducts a multi-disciplinary program of basic research in geospatial intelligence topics through grants and fellowships to the leading investigators, research universities, and colleges of the nation. This research provides the fundamental science support to NGA's applied and advanced research programs. The major components of the NGA Academic Research Program (NARP) are the NGA University Research Initiatives (NURI), the Historically Black College and University - Minority Institution Research Initiatives (HBCU-MI), the service Academy Research Grants, and the director of Central Intelligence Post-Doctoral Research Fellowships |
8,105 | Please write an abstract with title: Performance Analysis of MIMO-HARQ Assisted V2V Communications With Keyhole Effect, and key words: MIMO communication, Fading channels, Probability, Power system reliability, Scattering, Reliability, Spatial diversity. Abstract: Vehicle-to-vehicle (V2V) communications under dense urban environments usually experience severe keyhole fading effect especially for multi-input multi-output (MIMO) channels, which degrades the capacity and outage performance due to the rank deficiency. To avoid these, the integration of MIMO and hybrid automatic repeat request (HARQ) is proposed to assist V2V communications in this paper. By using the methods of integral transforms, the outage probabilities are derived in closed-form for different HARQ-assisted schemes, including Type I-HARQ, HARQ with chase combining (HARQ-CC), and HARQ with incremental redundancy (HARQ-IR). With the results, meaningful insights are gained by conducting the asymptotic outage analysis. Specifically, it is revealed that full time diversity order can be achieved, while full spatial diversity order is unreachable as compared to MIMO-HARQ systems without keyhole effect. Moreover, we prove that the asymptotic outage probability is a monotonically increasing and convex function of the transmission rate. More importantly, although HARQ-IR performs better than HARQ-CC owing to its higher coding complexity, this advantage becomes negligible in the large-scale array regime. Finally, the numerical results are verified by Monte-Carlo simulations along with some in-depth discussions. |
8,106 | Please write an abstract with title: A novel method to mitigate commutation failures in HVDC systems, and key words: HVDC transmission, Valves, Inverters, Bridge circuits, Control systems, Rectifiers, Fault detection, Circuit faults, Voltage fluctuations, Load flow. Abstract: In this paper we show a method to mitigate commutation failures in HVDC systems due to voltage dips from AC systems. The abc-/spl alpha//spl beta/ transformation is used for three-phase fault detection, and the zero-sequence voltage, which is obtained by the addition of the three-phase voltages, is used for single-phase fault detection. Both detection methods are based on instantaneous values, which ensure fast reaction of the control system when AC faults occur. After detecting the fault, an additional angle is deducted from the firing order at the inverter station, which in practice enlarges the commutation margin. The test results show that this method is very effective in reducing the risk of commutation failures. |
8,107 | Please write an abstract with title: Voltage Sensitivity Estimation Based on Measurements of Distributed PV Inverters, and key words: Reactive power, Voltage measurement, Sensitivity, Power measurement, Measurement uncertainty, Estimation, Inverters. Abstract: Quantifying how inverters can affect the grid voltage by active and reactive power changes enables advanced concepts for voltage support. A method for the estimation of the voltage sensitivity in a grid section with distributed PV generation is proposed and compared with analytic calculations. The method relies on the aggregation and evaluation of available voltage and power measurements. The necessity of linearly independent power injections is elaborated and the injection of reactive power pulses is proposed to increase the accuracy of the estimate. The method is validated by simulation and experimental results. |
8,108 | Please write an abstract with title: FCOS3D: Fully Convolutional One-Stage Monocular 3D Object Detection, and key words: Convolutional codes, Training, Three-dimensional displays, Costs, Estimation, Object detection, Transforms. Abstract: Monocular 3D object detection is an important task for autonomous driving considering its advantage of low cost. It is much more challenging than conventional 2D cases due to its inherent ill-posed property, which is mainly reflected in the lack of depth information. Recent progress on 2D detection offers opportunities to better solving this problem. However, it is non-trivial to make a general adapted 2D detector work in this 3D task. In this paper, we study this problem with a practice built on a fully convolutional single-stage detector and propose a general framework FCOS3D. Specifically, we first transform the commonly defined 7-DoF 3D targets to the image domain and decouple them as 2D and 3D attributes. Then the objects are distributed to different feature levels with consideration of their 2D scales and assigned only according to the projected 3D-center for the training procedure. Furthermore, the center-ness is redefined with a 2D Gaussian distribution based on the 3D-center to fit the 3D target formulation. All of these make this framework simple yet effective, getting rid of any 2D detection or 2D-3D correspondence priors. Our solution achieves 1st place out of all the vision-only methods in the nuScenes 3D detection challenge of NeurIPS 2020. Code and models are released at https://github.com/open-mmlab/mmdetection3d. |
8,109 | Please write an abstract with title: Multi-dimensional comparison and selection of high-quality drinking water renovation project schemes for communities, and key words: Simulation, Chlorine, Pipelines, Layout, Water quality, Hydraulic systems, Attenuation. Abstract: In order to respond to the “Water Pollution Prevention Action Plan” promulgated by the State Council and achieve the goal of direct drinking of municipal tap water in 2035, this article uses EPANET software to conduct a hydraulic simulation of the secondary water supply network of an old community in Shanghai. According to the current pipeline network layout, three other different pipeline network layout schemes were proposed, which are simulated to compare the water age, pressure, flow rate and other hydraulic conditions at each point. Choose a more appropriate transformation plan: the current situation and plan one, and optimize the water level of the pool and the diameter of the pipe network respectively. The simulation results show that the water level optimization and pipe diameter optimization of the pool can significantly shorten the water age, and the pressure and flow velocity are in a more appropriate range. According to the simulation results, the multi-dimensional comparison and selection are finally selected based on the current situation of the optimization of the water level of the pool and the pipe diameter. Pipe Network. After testing, all water quality indicators were up to standard after the renovation, and the residual chlorine attenuation coefficient was reduced by 53.3%. |
8,110 | Please write an abstract with title: Traffic Jam Prediction Based on Analysis of Residents Spatial Activities, and key words: Data models, Traffic congestion, Big Data applications, Logistics. Abstract: The prediction of urban traffic congestion has always been one of the important contents in the research of intelligent transportation systems. The difficulty in predicting urban traffic congestion is that urban traffic operation is essentially a collection of spatial activity planning for residents under certain conditions. The huge group of residents themselves has great complexity and uncertainty. Traditional neural networks mostly focus on road characteristic data and road condition data, and lack of in-depth exploration of the fundamental factors of traffic congestion for residents' travel. So we propose a traffic congestion prediction model based on the analysis of residents' spatial activities. Starting from the residents' activities, the simulation of urban traffic operation conditions can more realistically reflect the traffic congestion situation of the city at specific times and roads, and quickly generate model results. The experimental results show that the model analyzed by residents' spatial activities runs fast and has high prediction accuracy. The results are in line with the actual situation and have strong practical value. |
8,111 | Please write an abstract with title: Timing requirements on multi-processing and reconfigurable embedded systems with multiple environments, and key words: Multi-Processor System on Chip, virtualization, real-time, latency, hypervisor, Xen, Asymmetric Multi-Processing, OpenAMP. Abstract: In recent years, Multi-Processor System on Chip (MPSoC) devices are becoming more and more common in embedded systems, due to the possibilities and flexibility they offer. They allow running different environments simultaneously in a single platform, usually one for general purpose applications and another one for real-time processes. This is possible with a software technique such as hypervisors or Asymmetric Multi-Processing (AMP) frameworks, however, they can significantly affect the system in terms of latency. This work summarizes the main latencies a reconfigurable multi-core device with virtualized environments can have and proposes methods to measure and quantify latencies. |
8,112 | Please write an abstract with title: Trust and deception in mediated communication, and key words: Face detection, Collaboration, Collaborative work, Information management, Medical diagnostic imaging, Teamwork, Information resources, Psychology. Abstract: Guided by interpersonal deception theory and the principle of interactivity, this investigation examined whether communication modalities differentially affect the extent to which group members develop trust or are vulnerable to manipulation and deceit, based on the degree of interactivity the modalities afford. According to the principle of interactivity, involvement and mutuality should increase as one move from text to audio and audiovisual (AV) modalities, to face-to-face (FtF) communication. Under nondeceptive circumstances, greater interactivity should elicit corresponding increases in trust and credibility; under deceptive circumstances, it should produce greater truth biases and inaccurate detection of deceit. This effect should be partly mitigated in text and audio modalities due to the presence of diagnostic deception indicators Pairs were assigned to a truthful or deceptive condition in one of three mediated conditions, or in a face-to-face condition. In the deceptive condition, one member of each pair was enlisted to deceive during the interaction. Following discussion, participants rated their communicative behavior and the credibility of the truthful or deceptive actor. Truth bias and accuracy in judging deceptive information was calculated. Results are compared to previous findings from face-to-face deception. Implications for collaborative technologies are advanced. |
8,113 | Please write an abstract with title: Development of generator stator coil with 22kV global VPI insulation, and key words: Stators, Coils, Dielectrics and electrical insulation, Voltage, Testing, Resistance heating, Thermal stresses, Virtual manufacturing, Performance evaluation, Electric variables. Abstract: Recently, the demands for generators with large capacity are increasing in the market, and their rated voltage has been heightened accordingly. Therefore, it is required to manufacture high voltage stator windings to improve the quality of the insulation system and to strive for a long-term life. On the grounds of the above, we have evaluated numerous model coils and full-scale coil models by performing the heat cycle test, and established a computing program both for the electric field strength and the taping conditions. As a result of these studies, the development of a global vacuum pressure impregnation (VPI) insulation system for 22 kV has been completed successfully. |
8,114 | Please write an abstract with title: Torque Ripple Suppression of Permanent Magnet Synchronous Motor Based on Improved Active Disturbance Rejection Controller, and key words: Torque, Simulation, Resonant frequency, Observers, Harmonic analysis, Permanent magnet motors, Robustness. Abstract: The traditional auto disturbance rejection controller (ADRC) can’t effectively suppress the torque ripple of the permanent magnet synchronous motor (PMSM) caused by current sampling errors. A speed loop generalized integral-decoupled auto disturbance rejection controller (GI-DADRC) is proposed, which utilizes the high gain characteristics of quasi-resonant integrators at resonant frequencies to enhance the observation accuracy of extended state observer (ESO) against harmonics disturbance. This method not only retains the ability of traditional ADRC in suppressing the DC disturbance, but also improves its performance to suppress harmonics disturbance. Simulation results prove the feasibility of the proposed method. |
8,115 | Please write an abstract with title: Introduction to the Special Section on the 2020 Asian Solid-State Circuits Conference (A-SSCC), and key words: Special issues and sections, Meetings, Solid state circuits. Abstract: This Special Issue of the IEEE Journal of Solid-State Circuits (JSSC) includes some of the highlights of the best papers presented at the 2020 Asian Solid-State Circuits Conference (A-SSCC), which was held on November 9–11, 2020. A-SSCC 2020 was originally planned to be held in Hiroshima, Japan. However, due to COVID-19, A-SSCC 2020 had to become a virtual conference. As one of the five conferences fully sponsored by the IEEE Solid-State Circuits Society, the A-SSCC was in its 16th appearance in 2020 since its inauguration in 2005 in Taiwan. Rotating among Asian countries, the A-SSCC is quickly becoming one of the leading global forums for the presentation of advances in solid-state circuits and system-on-a-chip (SoC). From 2018, this conference accepts field-programmable gate array (FPGA) papers for presentation and demo and allows two-page format papers for submission and publication. |
8,116 | Please write an abstract with title: Gradient and Huygens’ Metasurface Design and Analysis Based on Transmission Line Theory, and key words: Magnetic resonance, Impedance, Prototypes, Surface impedance, Permittivity, Surface waves, Permeability. Abstract: In this article, a new transmission-line-based analysis is introduced to design the gradient and Huygens' metasurfaces. In this method, each unit cell of the gradient and Huygens' metasurfaces is modeled by a transmission line with a specific characteristic impedance and propagation constant. By using this method, a prototype for each of the gradient and Huygens' metasurfaces is designed and simulated. Each unit cell in the prototype consists of only one magneto-dielectric slab. Due to the difficulty of realizing the magneto-dielectric materials, a special unit cell structure consisting of three dielectric slabs is introduced. A prototype for each gradient and Huygens' metasurface is designed and simulated. To verify the designed structure, a Huygens' metasurface prototype is fabricated using Rogers TMM 13i substrate. The measured results are in good agreement with the theoretical results. |
8,117 | Please write an abstract with title: Machine Learning based Fall Detection Algorithms for Toddlers using Public and Experimental Datasets, and key words: Deep learning, Training, Pediatrics, Machine learning algorithms, Sensitivity, Computational modeling, Wearable computers. Abstract: Falling and its adverse impacts, especially for children under the age of six, have life long consequences. Fall detection, in such cases can be paramount for administering care quickly and efficiently. This paper addresses the concern of a dearth of fall datasets, with the falls being performed by actual toddlers, and presents a novel experimental dataset for the same. It also provides a comparison between multiple publicly available datasets, which are recorded by simulating falls by adults, across deep learning and machine learning models. Using a binary classification scheme to detect falls, the machine learning models are tested for both the experimental dataset as well as the publicly available ones. In the comparison of models, the kNN model showed favorable results, having the highest accuracy to our experimental dataset, that of 96 percent, with a sensitivity of 96.5 percent and specificity of 95.8 percent. Similar tests of models with the publicly available datasets highlight the significant difference in results when utilizing fall data simulated by adults and children. The research also sheds light on the application of such models in various wearables as well as the metrics to be deliberated over when choosing a suitable algorithm for this particular implementation. |
8,118 | Please write an abstract with title: Interrogation of a passive fiber Bragg grating resonator sensor by current modulation of a diode laser, and key words: Diode lasers, Capacitive sensors, Frequency modulation, Radio frequency, Resonance, Laser tuning, Optical resonators, Fabry-Perot, Optical fiber sensors, Optical sensors. Abstract: In this paper, experimental results for a current modulation frequency locking scheme in a single feedback control loop are presented, and are compared with the Pound-Drever-Hall (PDH) topology. This experiment provides confidence that with proper pre-stabilization of the diode laser in a more sophisticated two-loop control scheme, current modulation may well attain similar ultra-resolution strain sensitivities as those achieved using the PDH technique. |
8,119 | Please write an abstract with title: Canada's Emergency Geomatics Service Near Real-Time Flood Mapping from Multi-Source Data, and key words: Geomagnetism, Laser radar, Satellites, Spaceborne radar, Vegetation mapping, Radar imaging, Optical imaging. Abstract: The Canadian Emergency Geomatics Service (EGS) creates and disseminates flood maps in near real time during major flood events. In 2017, the EGS developed and deployed a fully automated method to map open water and flooded vegetation using available optical and radar imagery. This method employs machine learning trained using historical inundation maps to classify open water followed by region growing to map flooded vegetation, and requires only a few sensor-specific parameters for different input satellite data. Recent collection of High-Resolution Digital Elevation Model (HRDEM) lidar data over important floodplains, in Canada, in combination with in-situ flood perimeter observations from an EGS-developed Citizen Geographic Information (CGI) mobile application or other sources, has facilitated the development of better urban flood mapping where traditional satellite-based methods fail. This presentation will describe existing operational EGS flood mapping methods with examples from previous activations, as well as new developments in urban flood mapping that will become operational depending on the availability ofrequired input data. |
8,120 | Please write an abstract with title: An Efficient Npusch Receiver Design For Nb-Iot System, and key words: Channel estimation, Interpolation, Receivers, 3GPP, Discrete Fourier transforms, Estimation error. Abstract: As specified in Release 13 specification of the 3rd Generation Partnership Project (3GPP), narrowband physical uplink shared channel (NPUSCH) is a critical physical layer component of narrowband Internet-of-Things (NB-IoT) system. This paper designs and implements an efficient NPUSCH receiver by using modified discrete Fourier transform channel estimation and exponential moving average interpolation. Moreover, three key blocks including channel equalization, soft demodulation and soft combining are implemented for a full receive processing chain. Extensive simulation results corroborate that the designed receiver obtains lower block error rate than the benchmark specified by 3GPP. |
8,121 | Please write an abstract with title: Move&Find: The Value of Kinaesthetic Experience in a Casual Data Representation, and key words: Data visualization, Google, Creativity, Task analysis, Bicycles, Servers, Human computer interaction. Abstract: The value of a data representation is traditionally judged based on aspects like effectiveness and efficiency that are important in utilitarian or work-related contexts. Most multisensory data representations, however, are employed in casual contexts where creativity, affective, physical, intellectual, and social engagement might be of greater value. We introduce Move&Find, a multisensory data representation in which people pedalled on a bicycle to exert the energy required to power a search query on Google's servers. To evaluate Move&Find, we operationalized a framework suitable to evaluate the value of data representations in casual contexts and experimentally compared Move&Find to a corresponding visualization. With Move&Find, participants achieved a higher understanding of the data. Move&Find was judged to be more creative and encouraged more physical and social engagement—components of value that would have been missed using more traditional evaluation frameworks. |
8,122 | Please write an abstract with title: Towards a fractioned treatment in conformal radiotherapy using 3D-multimodal data registration, and key words: Medical treatment, Cathode ray tubes, Neoplasms, Cancer, Registers, Calibration, Testing, Performance evaluation, Imaging phantoms, Protocols. Abstract: The combination of conformal radiotherapy and fractioned radiotherapy is a very useful tool against cancer. Meanwhile, this combination is only interesting if the patient positioning method is accurate and non invasive. This paper presents an algorithm fulfilling the latter conditions. The method was developed for tumors located in the head and does not need any patient dedicated device. Homologous structures, acquired with a computer tomograph and with a sensor fixed in the treatment room, are used to register two 3D-surfaces. The registration scheme is notably based on the directed Hausdorff distance. The registration, together with a calibration of the 3D-sensor in the therapy room, leads to a mean positioning error of 0.77 mm. Tests performed with a phantom deliver also a maximal error of 1.6 mm. |
8,123 | Please write an abstract with title: Organic resin method for highly reactive and homogeneous hexaferrite powders, and key words: Resins, Powders, Scanning electron microscopy, Magnetic materials, Ferrites, Ceramics, Temperature, Magnetization, X-ray diffraction, Magnetic analysis. Abstract: Hexagonal ferrites with M, Y and W structures were prepared from powders obtained by the decomposition of organometallic salt (citrate) solidified solutions, Due to the improved reactivity of these powders with respect to the classical ceramic ones, a number of advantages were obtained: pure hexaferrites were produced at lower temperature; they exhibited improved magnetization and coercitivity; a finer and more homogeneous granulometry was achieved in the final products. X-Ray diffractometry, magnetic analysis and SEM microscope observations were used for characterizing the obtained materials. |
8,124 | Please write an abstract with title: Classification of Electroencephalograms during Mathematical Calculations Using Deep Learning, and key words: Deep learning, Neurons, Feature extraction, Entropy, Brain-computer interfaces, Mathematical models, Electroencephalography. Abstract: Classifying Electroencephalogram(EEG) signals helps in understanding Brain-Computer Interface (BCI). EEG signals are vital in studying how the human mind functions. In this paper, we have used an Arithmetic Calculation dataset consisting of Before Calculation Signals (BCS) and During Calculation Signals (DCS). The dataset consisted of 36 participants. In order to understand the functioning of neurons in the brain, we classified BCS vs DCS. For this classification, we extracted various features such as Mutual Information (MI), Phase Locking Value (PLV), and Entropy namely Permutation entropy, Spectral entropy, Singular value decomposition entropy, Approximate entropy, Sample entropy. The classification of these features was done using RNN based classifiers such as LSTM, BLSTM, ConvLSTM, and CNN-LSTM. The model achieved an accuracy of 99.72% when entropy was used as a feature and ConvLSTM as a classifier. |
8,125 | Please write an abstract with title: Investigations of Object Detectors with Deep Learning Methods: A Review, and key words: Deep learning, Semantics, Detectors, Object detection, Computer architecture, Feature extraction, Transformers. Abstract: Over the past ten years, deep learning methods has achieved great progress in the field of computer vision (CV), especially in object detection. In contrast with traditional detection methods, deep learning methods significantly outperform those in real-time performance and accuracy without any complicated hand-crafted process of feature extraction. The powerful ability of convolutional neural networks (CNNs) to extract features was realized as image classification task made breakthroughs by employing it. Therefore, many researchers attempt to apply CNNs which can learn high-level semantic features to object detection, producing some representative models like classical one-stage detectors and two-stage detectors. Besides, in recent years, Transformer which shows extraordinary talents in the field of natural language processing (NLP) has also been utilized in object detection models. A kind of novel detectors has been proposed based on transformer encoder-decoder architecture without usage of anchor generation and non-maximum suppression (NMS) postprocessing, which starts a new detection mode—set prediction, and gains great performance. In this paper, we summarize various detectors from different detection modes. To begin with, our review shows architecture of classical two-stage detectors and one-stage detectors. Then, transformer-based detectors are introduced in detail. Experimental evaluation is also provided to compare performance from various detectors. Finally, we raise a conclusion and future prospects to serve as a guideline for future work. |
8,126 | Please write an abstract with title: Deep Autotuner: A Pitch Correcting Network for Singing Performances, and key words: Tracking, Neural networks, Music, Multiple signal classification, Task analysis, Speech processing, Spectrogram. Abstract: We introduce a data-driven approach to automatic pitch correction of solo singing performances. The proposed approach predicts note-wise pitch shifts from the relationship between the respective spectrograms of the singing and accompaniment. This approach differs from commercial systems, where vocal track notes are usually shifted to be centered around pitches in a user-defined score, or mapped to the closest pitch among the twelve equal-tempered scale degrees. The proposed system treats pitch as a continuous value rather than relying on a set of discretized notes found in musical scores, thus allowing for improvisation and harmonization in the singing performance. We train our neural network model using a dataset of 4,702 amateur karaoke performances selected for good intonation. Our model is trained on both incorrect intonation, for which it learns a correction, and intentional pitch variation, which it learns to preserve. The proposed deep neural network with gated recurrent units on top of convolutional layers shows promising performance on the real-world score-free singing pitch correction task-autotuning. |
8,127 | Please write an abstract with title: A Comparison Between Conventional and User-Intention-Based Adaptive Pushrim-Activated Power-Assisted Wheelchairs, and key words: Wheelchairs, Wheels, Propulsion, Torque, Kinetic theory, Batteries, Microcontrollers. Abstract: Pushrim-activated power-assisted wheel (PAPAW) users ideally require different levels of assistance depending on activity and preference. Therefore, it is important to design and develop adaptive PAPAW controllers to account for these differences. The main objective of this work was to integrate a user intention estimation framework into a PAPAW and develop personalized adaptive controllers. We performed experiments to gather kinetics of wheelchair propulsion for a variety of daily life wheelchair activities. The propulsion characteristics (i.e., pushrim forces) were used to train intention estimation models and characterize implicit user intentions when performing daily life wheelchair maneuvers. These intentions included moving straight forward, performing a right/left turn, and braking. The intention estimation framework, based on random forest classification algorithms and kinetic features, was implemented and tested in our laboratory-developed PAPAW. This computationally efficient framework was successfully implemented and tested for each participant in real-time. Our results revealed that the real-time user intention predictions were similar to the offline models. The power-assist ratio of each wheel was adjusted based on which user intention was identified. Data collected from four participants provided evidence regarding the effectiveness of using adaptive intention-based controllers. For instance, the propulsion effort was significantly reduced when using an adaptive PAPAW controller. Subjective views of participants regarding the workload of wheelchair propulsion (e.g., physical/cognitive effort) were also gathered. Our findings suggest that rankings of different controllers varied among different participants and across different wheelchair maneuvers, indicating the need for customized adaptive controllers to fit different users’ activities and preferences. |
8,128 | Please write an abstract with title: Full-Duplex Covert Communications Assisted by Intelligent Reflective Surfaces, and key words: Interference, Full-duplex system, Downlink, Channel estimation, Uplink, Jamming, Error probability. Abstract: The letter proposes resource allocation in uplink covert communication systems, which aim to hide the existence of the covert user from the warden. The wireless system consists of a full-duplex receiver, an intelligent reflective surface (IRS), a public user, a covert user, and a watchful warden. The receiver sets the IRS reflection matrix so as to maximize the downlink throughput to the public user. In doing so, in each transmission block we optimize the covert user’s transmit power and rate, subject to the detection error probability at the warden and predefined interference level at the public user. The numerical results unveil the importance of increasing the number of reflecting elements at the IRS. |
8,129 | Please write an abstract with title: Multimodal Fusion for Segment Classification in Folk Music, and key words: Support vector machines, Measurement, Computational modeling, Music, Feature extraction, Data models, Computational efficiency. Abstract: A folk music segment classification system that uses a multimodal fusion of acoustic features, textual information and duration based feature on Thiruvathirakali music corpus is proposed. Acoustic features are learned from musical texture features (MTF) using a long short term memory (LSTM) model. A term frequency-inverse document frequency (TF-IDF) model is employed to derive text-based features from transcription data. For multimodal fusion, early integration of the LSTM derived features, TF-IDF features and duration feature is employed. An attempt to optimise the LSTM model is carried out through frame fusion in the temporal domain. Frame fusion is seen to increase classification efficiency by 13 percent and reduce computational expense by tenfold. The system reports an overall precision, recall and F1 measure of 0.53, 0.52 and 0.51 respectively for an LSTM model with frame fusion, with better performance over a baseline SVM classifier. The classification efficiency is seen to improve by 15 percent (absolutely) with the addition of each multimodal component. For complete multimodal fusion, the metrics improve to 0.83, 0.78 and 0.80 respectively. |
8,130 | Please write an abstract with title: Pseudorandom bits generated by chaotic maps, and key words: Chaos, Cryptography, NIST, Algorithm design and analysis, Standards development, Circuit testing, Upper bound, US Department of Commerce, Proposals, Documentation. Abstract: Different possibilities of using chaotic maps as pseudorandom number generators are discussed. A class of chaos-based pseudorandom bit generators is constructed. We give simple arguments to explain the unpredictability of the generators. |
8,131 | Please write an abstract with title: Energy-Efficient Precision-Scaled CNN Implementation With Dynamic Partial Reconfiguration, and key words: Convolutional neural networks, Field programmable gate arrays, Computer architecture, Convolution, Reconfiguration logic, Feature extraction, Power demand, Energy efficiency, Precision engineering. Abstract: A convolutional neural network (CNN) classifies images with high accuracy. However, CNN operation requires a large number of computations which consume a significant amount of power when implemented on hardware. Precision scaling has been recently used to reduce the hardware requirements and power consumption. In this paper, we present an energy-efficient precision-scaled CNN (EEPS-CNN) architecture. Furthermore, the Field Programmable Gate Array (FPGA) is reconfigured during run time using Dynamic Partial Reconfiguration (DPR). If the battery level decreases, the EEPS-CNN design with the most appropriate power consumption is configured on the FPGA. DPR enables recognition applications to run at a low power budget while sacrificing minor accuracy instead of termination. The proposed architecture is implemented on Xilinx XC7Z020 FPGA and is evaluated on three datasets: MNIST, F-MNIST, and SVHN datasets. The results show a 2.2X, 2.39X, and 2.38X reduction in the energy consumption, respectively, while using only 7 bits to represent all inputs and network parameters. The accuracy of the proposed EEPS-CNN is only 0.53%, 3.67%, and 0.88% less than 32-bit floating-point architectures for MNIST, F-MNIST, and SVHN, respectively. Moreover, the results show up to 92.91X and 4.84X reductions in the power and energy consumption of the proposed EEPS-CNN compared to related designs developed for the MNIST dataset. |
8,132 | Please write an abstract with title: Signatures of exciton correlations in the time-resolved vectorial polarization state of four-wave mixing signals from semiconductor quantum wells, and key words: Quantum wells, Optical mixing, Excitons. Abstract: Summary form only given. The microscopic many-body theory applied to the time-resolved vectorial polarization state of the FWM signal documents two-exciton correlations. Under our experimental conditions, the biexciton dephasing rate is found to be much less than twice the exciton dephasing rate. |
8,133 | Please write an abstract with title: Design and Application of Embedded System Based on ARM7 LPC2104 Processor in Telemedicine, and key words: Embedded system, Telemedicine, Real time systems, Operating systems, Universal Serial Bus, Internet, Optical fiber communication, Hardware, Energy consumption, Power system reliability. Abstract: This paper, based on ARM7 processor and real-time embedded operating system (μC/OS-II), establishes an embedded telemedicine platform ground on LPC2104 and realizes some very popular embedded application technologies such as USB communication, embedded Internet communication, infrared communication, etc. Meanwhile the volume of the hardware is smaller; power consumption is lower; the functions are mightier and the expansibility is stronger. In addition, for the embedded real-time μC/OS-II in use has gone through the reliability authentication, the whole running system is more stable and the program maintenance and update is more convenient. The telemedicine system based on this technology has been tested to be stable and efficient, and has obtained the results as expected. |
8,134 | Please write an abstract with title: Harvesting Production GraphQL Queries to Detect Schema Faults, and key words: Software testing, Conferences, Pipelines, Finance, Production, Behavioral sciences, Test pattern generators. Abstract: GraphQL is a new paradigm to design web APIs. Despite its growing popularity, there are few techniques to verify the implementation of a GraphQL API. We present a new testing approach based on GraphQL queries that are logged while users interact with an application in production. Our core motivation is that production queries capture real usages of the application, and are known to trigger behavior that may not be tested by developers. For each logged query, a test is generated to assert the validity of the GraphQL response with respect to the schema. We implement our approach in a tool called AutoGraphQL, and evaluate it on two real-world case studies that are diverse in their domain and technology stack: an open-source e-commerce application implemented in Python called Saleor, and an industrial case study which is a PHP-based finance website called Frontapp. AutoGraphQL successfully generates test cases for the two applications. The generated tests cover 26.9 % of the Saleor schema, including parts of the API not exercised by the original test suite, as well as 48.7% of the Frontapp schema, detecting 8 schema faults, thanks to production queries. |
8,135 | Please write an abstract with title: Joint Management of Compute and Radio Resources in Mobile Edge Computing: A Market Equilibrium Approach, and key words: Resource management, Computational modeling, Servers, Numerical models, Microprocessors, Computer architecture, Task analysis. Abstract: Edge computing has been recently introduced to bring computational capabilities closer to end-users of modern network-based services, supporting existing and future delay-sensitive applications by effectively addressing the high propagation delay issue that affects cloud computing. However, the problem of efficiently and fairly managing the system resources presents particular challenges due to the limited capacity of both edge nodes and wireless access networks and the heterogeneity of resources and services’ requirements. To this end, we propose a techno-economic market where service providers act as buyers, securing both radio and computing resources to execute their associated end-users’ jobs while being constrained by a budget limit. We design an allocation mechanism that employs convex programming to find the unique market equilibrium point that maximizes fairness while ensuring that all buyers receive their preferred resource bundle. Additionally, we derive theoretical properties that confirm how the market equilibrium approach strikes a balance between fairness and efficiency. We also propose alternative allocation mechanisms and give a comparison with the market-based mechanism. Finally, we conduct simulations to numerically analyze and compare the performance of the mechanisms and confirm the market model's theoretical properties. |
8,136 | Please write an abstract with title: Detection of Polymer-shelled ultrasound contrast agents using a signal subtraction method, and key words: Ultrasonic imaging, Acoustic signal detection, Optical harmonic generation, Optical polymers, Acoustic pulses, High speed optical techniques, Nonlinear optics, Cameras, Optical pulses, Signal design. Abstract: Polymer-shelled contrast agents demonstrate unique properties because the enclosed gas oscillates freely only after the shell is damaged. We have observed this behavior optically using a high-speed camera, and hypothesize that it leads to the observed acoustical property that the response of a polymer-shelled bubble to a two-pulse sequence depends on the order of pulse transmission. We have observed this property in two different polymer-shelled contrast agents. Based on these findings, we designed a pulse sequence to detect polymer-shelled bubbles, "signal subtraction", in which two same-phase single-cycle pulses are transmitted in succession and the resulting echoes subtracted. This subtraction results in the cancellation of tissue echoes, even in the presence of tissue harmonic generation, with only a small reduction in bubble signal amplitude. |
8,137 | Please write an abstract with title: Prediction of Parkinson's Disease using Hybrid Feature Selection based Techniques, and key words: Neurological diseases, Parkinson's disease, Predictive models, Boosting, Feature extraction, Hybrid power systems, Random forests. Abstract: Parkinson's disease (PD) is one of the significant severe problems globally in recent times. It is a neurological disorder that progresses over time and the most severe problems after Alzheimer's disease. Our article proposes a Hybrid Feature Selection system for the initial detection of PD from speech recordings. This method picks the best set of instances that can lessen instance vector dimensions from 22 to 5. We have proposed a machine learning-based model using five different classifiers named Random Forest, Logistic Regression, XGBoost, AdaBoost, and Gradient Tree Boosting. Gradient Tree Boosting presents the best appearance with a spectacular accuracy of 98.31% and the area under the ROC curve 98.66%, among all classifiers used to predict PD. We showed that the stated design has greater accuracy than the current methods available in the literature, and the number of instances is less than others. |
8,138 | Please write an abstract with title: Detection of heap management flaws in component-based software, and key words: Application software, Logic programming, Computer languages, Programming profession, Memory management, Embedded software, Software systems, Writing, Runtime, Java. Abstract: Heap management is responsible for the allocation of heap segments to a running application. When the logic of the heap management is left to the application programmer, as it is the case with programming languages like C and C++, a number of problems may arise. One kind of problems related to imperfect heap management is that of memory leaks, which happen when heap segments become inaccessible before they are deallocated. Closely related to that problem, from the standpoint of programmer's operations, is the problem of corrupted heap due to redundant attempts to deallocate the same heap segment that has been previously allocated. This work presents a method for detecting such flaws in heap management. Our method is based on traces collected during the execution of an application and their off-line analysis in order to determine the presence of memory leaks and redundant deallocations of the same heap segment. When our method is applied to component-based embedded software, it allows to locate the component that had allocated heap memory and did not deallocate it before exiting, as well as the components that are responsible for the redundant deallocation of heap segments. |
8,139 | Please write an abstract with title: Genetic algorithms based analyses of nonlinearly loaded antenna arrays including mutual coupling effects, and key words: Genetic algorithms, Algorithm design and analysis, Loaded antennas, Antenna arrays, Mutual coupling, Microwave circuits, Microwave antennas, Linear antenna arrays, Equivalent circuits, Scattering. Abstract: Initially, the analysis of a single nonlinearly loaded antenna is transformed into a nonlinear microwave circuit with the circuit elements representing the antenna element and the lumped load. This equivalent circuit is then reformulated into an optimization problem which can be solved by genetic algorithms. The analyses can also be easily extended to finite and infinite nonlinearly loaded antenna arrays including mutual coupling effects. Numerical examples show that the results by genetic algorithms are consistent with those using harmonic balance techniques. With the use of genetic algorithms, our analyses do not require a suitable guess of an initial solution and there exists no gradient operations in the iteration procedures. Therefore, the analyses are suitable for problems of nonlinearly loaded antenna arrays with any types of lumped loads and the array mutual coupling effects are included. |
8,140 | Please write an abstract with title: DNA-Based Molecular Computing, Storage, and Communications, and key words: DNA, Memory, Writing, Information and communication technology, DNA computing, Tutorials, Molecular communication. Abstract: DNAs exist in nature and could provide solutions to computing, storage, and communications as existing ones approach their physical limits. Plenty of research work has been conducted on DNA-based computing, data storage and molecular communications (MCs), but largely in isolation. There is a lack of a unified place where the triples are put together to be discussed. This article aims to filling in this gap by providing an overview of each triplet. Starting from an overall description of DNA features and their reading and writing in practical terms, this article goes on to describe each of the three from three aspects: 1) requirements and differences from current electronic-dominating technologies; 2) their working principles; and 3) practical considerations. Recent advancement in each area is summarized and discussed. Furthermore, this article intends to call for researches that go beyond the boundary of each and encourages interconnection and joint research among the three. It proposes a molecular information and communication technology (ICT) system architecture with all its three components underpinned by DNAs. This article also identifies and discusses some new future directions, such as joint coding for storage and communications, directional DNA-based MCs, interfaces between molecular DNA systems and electronic systems. It is hoped that this article can spark more joint research across computing, storage, and communications in this exciting field of DNA-based molecular ICT systems. |
8,141 | Please write an abstract with title: Modern Maintenance Strategies Prescriptive Approach Using Machine learning, and key words: Classifier, machine-learning, algorithms, maintenance, classification. Abstract: With most industrial processes requiring electric motors for all their pumps and drive mechanisms, it is not always possible to have the all the sensors that include axial movements, drive and non-drive-end temperature monitors, and if you combine all these sensors the cost of which outdo the cost of replacing the motor. It is of importance that the evaluation of the cost of downtime thereof is done to ensure whether the spent on such sensors is viable. The characteristics of the motor will always change with differing surroundings, load, and frequency of start-stop and these are the characteristics that have been taken advantage of in this research. The predictive maintenance, in this case, was made from classification models that did categorize the following critical factors that affect the performance of the small motors that include surrounding environment and running temperature, motor speed, and load current. Several experiments were carried out with the motor to find out which classification model gave the best results. |
8,142 | Please write an abstract with title: Introduction of Phrase Structures into the Example-Based Machine Translation System, and key words: Syntactics, Dictionaries, Analytical models, Tools, Task analysis, Grammar, Computational modeling. Abstract: The formal model of the syntax structure of texts based on representations of phrase structures as generalized syntagms and methods of their automatic construction are described. A new solution to a number of current problems of automatic processing of text information in the field of information search and machine translation, as well as an approach to the problem of unification of syntax structures of sentences and phrase structures constituting the sentences has been proposed. Declarative tools which are a complex of dictionaries and grammatical tables in machine form were created on the basis of large-scale studies of extensive volumes of scientific and technical texts using linguistic and statistical methods. |
8,143 | Please write an abstract with title: A self-sustainable home: ‘BAITYKOOL’ developed for the extreme warm climate an experimentation of active & passive strategies, and key words: Heating systems, HVAC, Cooling, Photovoltaic cells, Prototypes, Lighting, Glass. Abstract: The paper shares the design of the self-sustaining energy efficient 90 Sq. m eco-responsive solar regions with the use of innovative systems having the combination of the active and passive strategies. The project named BAITYKOOL prototype was designed, constructed, assembled and tested as a competition entry for the Solar Decathlon Middle East (SDME 2018). The house works as a biological eco system developed to suit the culture and climate condition of the region. The comfort conditions of the habitat and the house performance has been enhanced with development of the innovative systems - the compact composite house envelop works effectively to enhance the comfort conditions within the house with reduced cooling load and lighting system worked with control mechanisms for the ambient light quality as suiting to the user based on the activity. A smart water management system with a monitoring system to optimize the use of water has been implemented. This adds value to every drop of water used being filtered by the Lumbrifilter and an UV treatment system being used for the aquaponic system that crystallizes the biodiversity. The HVAC system takes advantage of the night sky acting as a heat with the radiative sky cooling system. The energy requirements of the house has been met by the solar panels used in the prototype integrated architecturally on the roof as dynamic pergolas and on the wall as vertical panels maintain the energy balance. The biomimetic solar cells mounted on the glass panels generates higher energy and maintains an energy balance. The prototype exhibits the innovative systems and its strategies taken in design, construction technique, technology used and its operations to have an eco-responsive solution developed for a healthy living and working suited to the extreme warm climate of the region. |
8,144 | Please write an abstract with title: Analysis and Design of Bipolar Programmable-Gain Amplifiers Using Digital Potentiometers, and key words: Workability, Resistors, Negative feedback, Design methodology, Measurement uncertainty, Potentiometers, Stability analysis. Abstract: This paper presents a theoretical analysis and design procedure of versatile programmable amplifier circuits with bipolar gain. In particular, under analysis are two basic electronic circuits of single- and two-stage bipolar program-mable-gain amplifiers employing monolithic CMOS digital potentiometers. For both circuits, a single digital potentiometer is connected as a voltage divider in the negative feedback network of an op-amp. As a result of adjusting the position of the wiper of the potentiometer, the depth of the feedback changes, and hence the voltage gains change. Based on theoretical analysis of the circuits, analytical expressions for the basic static and dynamic parameters are derived. Moreover, using those formulas, approaches for selecting an appropriate circuit configuration and recommendations for selecting passive and active component values are proposed. The workability of the presented design recommendations is proved by computer simulations and experimental testing of sample analog circuits. The comparative analysis between simulation and measured results shows that the maximum relative error is up to 10%, which ensures a sufficient degree of accuracy in comparison to the tolerances of the electrical parameters. |
8,145 | Please write an abstract with title: Blocking artifact detection and reduction in compressed data, and key words: Discrete cosine transforms, Image coding, Quantization, Laplace equations, Transform coding, Frequency domain analysis, Pixel, Decoding, Image reconstruction, Information processing. Abstract: A novel frequency-domain technique for image blocking artifact detection and reduction is presented. The algorithm first detects the regions of the image which present visible blocking artifacts. This detection is performed in the frequency domain and uses the estimated relative quantization error calculated when the discrete cosine transform (DCT) coefficients are modeled by a Laplacian probability function. Then, for each block affected by blocking artifacts, its DC and AC coefficients are recalculated for artifact reduction. To achieve this, a closed-form representation of the optimal correction of the DCT coefficients is produced by minimizing a novel enhanced form of the mean squared difference of slope for every frequency separately. This correction of each DCT coefficient depends on the eight neighboring coefficients in the subband-like representation of the DCT transform and is constrained by the quantization upper and lower bound. Experimental results illustrating the performance of the proposed method are presented and evaluated. |
8,146 | Please write an abstract with title: Interface magnetic properties of epitaxial Fe-InAs heterostructures, and key words: Magnetic properties, Magnetic films, Iron, Substrates, Laboratories, Plasma temperature, Electrons, X-ray diffraction, Magnetooptic effects, Kerr effect. Abstract: The growth and interface magnetic properties of epitaxial Fe films grown on InAs [100]-4/spl times/2 have been studied using low-energy electron diffraction, in situ magneto-optical Kerr effect, and X-ray magnetic circular dichroism. The magnetic properties at room temperature were found to proceed via three phases with thickness; a nonmagnetic phase, a superparamagnetic phase, and a ferromagnetic phase. The initial ferromagnetic phase might be stabilized by interparticle interactions. The films show bulk-like spin moments of 1.90 /spl plusmn/ 0.15 /spl mu//sub B/ with the thickness above about 20 ML and a large enhancement /spl sim/ 260% of the ratio of orbital versus spin moment in the ultrathin region. |
8,147 | Please write an abstract with title: Parallel algorithms for the medial axis transform on linear arrays with a reconfigurable pipelined bus system, and key words: Parallel algorithms, Phase change random access memory, Concurrent computing, Optical arrays, Computational modeling, Pixel, Information management, Educational institutions, Optical computing, Image processing. Abstract: In this paper based on the advantages of both optical transmission and electronic computation, we first provide an O(log log N) bus cycles parallel algorithm for the medial axis transform of an N/spl times/N binary image on a linear array with a reconfigurable pipelined bus system using N/sup 2/ processors. By increasing the number of processors, the proposed algorithm can be modified to run in O(log log/sub q/ N) and O(1) bus cycles using qN/sup 2/ and N/sup 2+1//spl isin// processors respectively, where 1/spl les/q/spl les//spl radic/N, /spl isin/ is a constant and /spl isin//spl ges/1. These results improve on previously known algorithms developed on various parallel computation models. Key Words: Medial axis transform, image processing, image compression, computer vision, parallel algorithms, linear array with a reconfigurable pipelined bus system. |
8,148 | Please write an abstract with title: A High Speed Fully Integrated Capacitive Digital Isolation System in 0.35 µm CMOS for Industrial Sensor Interfaces, and key words: Temperature measurement, Temperature sensors, Semiconductor device modeling, Simulation, Power control, CMOS process, Amplitude modulation. Abstract: This work presents the implementation and simulation of a high speed fully integrated capacitive digital isolation system in 0.35 μm CMOS process. Pulse amplitude modulation scheme was adopted for the proposed design to allow high data rates while maintaining a small integration area compared to the current state-of-art works. The proposed modulation scheme eliminates the need of additional larger on-chip capacitor to support low-frequency operation. Simulation results show that the proposed system supports a wide range of data rates between 50 kbps and 500 Mbps. Moreover, the design shows a propagation delay of only 2 ns from input to output, which allows fast operation. |
8,149 | Please write an abstract with title: An area and power efficient RAKE receiver architecture for DSSS systems, and key words: Fading, Multipath channels, Spread spectrum communication, Fingers, Multiaccess communication, Clocks, Complexity theory, Computer architecture, Power dissipation, Hardware. Abstract: In this paper, an area and power efficient RAKE receiver architecture is proposed for base and mobile-stations employing the direct sequence spread spectrum (DSSS) technique. One common parallel de-spreader provides precomputed sub-symbols to fingers for the proposed design, and, hence, each finger can operate at a lower clock speed to save power. Our simulation results indicate that the proposed RAKE architecture for a WCDMA system reduces power dissipation by 37% and the circuit complexity by 28% compared with that of a conventional RAKE receiver. |
8,150 | Please write an abstract with title: Filter bank based narrowband interference detection and suppression in spread spectrum systems, and key words: Filter bank, Narrowband, Interference suppression, Spread spectrum communication, Jamming, Signal synthesis, Channel bank filters, Signal analysis, Filtering, Electronic mail. Abstract: A complex modulated filter bank based narrowband interference detection and suppression method is developed and its performance is studied in a spread spectrum system. The use of an efficient decimated filter bank with a highly selective subband filter prototype, in combination with a newly developed excision algorithm, offers a solution with efficient implementation that gives better performance than the FFT-based reference systems, especially in the presence of strong interference. |
8,151 | Please write an abstract with title: The junction matrix in the analysis of scattering networks, and key words: Scattering, Jacobian matrices, Integrated circuit interconnections, Impedance, Admittance, Voltage, Network topology, Computer networks, Equations. Abstract: A "scattering network" is an interconnection of multiports whose electrical properties are described by scattering matrices. The junction matrix defines the constraints imposed on the interconnected ports. This paper shows how the junction matrix is derived from the topological properties of the graph which represents the interconnections and how it is combined with the scattering matrices of the component multiports to arrive at the scattering matrix of the network. |
8,152 | Please write an abstract with title: Unsupervised learning based mining of academic data sets for students’ performance analysis, and key words: Computational modeling, Supervised learning, Machine learning, Predictive models, Data models, Performance analysis, Data mining. Abstract: The main purpose of the Educational Data Mining domain is to provide additional insights into the students’ learning mechanism and thus to offer a better understanding of the educational processes. This paper investigates the usefulness of unsupervised machine learning methods, particularly principal component analysis and relational association rule mining in analysing students’ academic performance data, with the broader goal of developing supervised learning models for students’ performance prediction. Experiments performed on a real academic data set highlight the potential of unsupervised learning models for uncovering meaningful patterns within educational data, patterns which will be relevant for predicting the students’ academic performance. |
8,153 | Please write an abstract with title: Deep Convolutional Long Short-Term Memory Network based video abnormal behavior prediction, and key words: Integrated optics, Correlation, Convolution, Prediction methods, Mean square error methods, Optical imaging, Hardware. Abstract: A deep convolutional long short-term memory network (DC-LSTM) based video abnormal behavior prediction method has been proposed. The DC-LSTM deepens the single-layer convolution of the convolutional LSTM, which can be applied to suppress structural information ambiguity in predicting multiple frames. Mean square error is combined with structural similarity to perform loss reconstruction for correlative calculating between predicted and input frames. An adaptive dynamic double-threshold strategy based on the loss reconstruction is adopted to determine whether the video is abnormal. Comparisons with some state-of-the-arts have highlighted the superior performance of the proposal. |
8,154 | Please write an abstract with title: Improved quality of service for WCDMA networks and coexistence with indoor wireless technologies, and key words: Quality of service, Multiaccess communication, Downlink, Interference, Base stations, GSM, Bit rate, USA Councils, Feedback, Europe. Abstract: In this paper we use a WCDMA network simulator to evaluate the different performance criteria. We also simulate a transmit diversity scheme and use the results of the diversity scheme in the simulator to evaluate the QoS (quality of service) enhancements obtained. Further we explore the possibility of a coexistence of a WCDMA network with the WIPAS (wireless IP access system). |
8,155 | Please write an abstract with title: Application of speech recognition to African elephant (Loxodonta africana) vocalizations, and key words: Speech recognition, Animals, Acoustic noise, Speech processing, Working environment noise, Feature extraction, Cepstral analysis, Robustness, Biomedical acoustics, Signal processing algorithms. Abstract: This paper presents a novel application of speech processing research, classification of African elephant vocalizations. Speaker identification and call classification experiments are performed on data collected from captive African elephants in a naturalistic environment. The features used for classification are 12 mel-frequency cepstral coefficients plus log energy computed using a shifted filter bank to emphasize the infrasound range of the frequency spectrum used by African elephants. Initial classification accuracies of 83.8% for call classification and 88.1% for speaker identification were obtained. The long-term goal of this research is to develop a universal analysis framework and robust feature set for animal vocalizations that can be applied to many species. |
8,156 | Please write an abstract with title: Mapping Heterogeneous Interfaces for System Integration, and key words: Knowledge engineering, Program processors, Ergonomics, Semantics, System integration, Software systems, Service-oriented architecture. Abstract: The utility of modern software systems is dependent on their ability to change. Driven by the need to remain relevant, software systems are subject to continuous and incremental integration. This need blurs the traditional separation between development and sustainment, and favors modularity as a highly desired architectural quality. Modularity in software systems partitions system functions into individually manageable services. Individual services can be tested, updated, scaled, and eventually replaced. A change in a service, however, often ripples through a system in the way it interacts with other services. The integration of a new service can be a non-trivial engineering activity that often requires interface changes. Such changes require mapping between two or more heterogeneous software interfaces. In this paper we examine the problem of interface mapping as it pertains to service-oriented architectures and provide system engineering considerations for design and implementation of interface-mapping software. Our considerations seek to inform the system engineering process and present practical guidance for reference. We demonstrate our engineering considerations as applied to an exemplar wealth aggregation service. |
8,157 | Please write an abstract with title: Studies on the pull-up RF MEMS switch for the lower actuation voltage and high speed using double electrode, and key words: Switches, Radiofrequency microelectromechanical systems, Voltage, Electrodes, Contacts, Electrostatics, Micromechanical devices, Glass, Millimeter wave communication, Millimeter wave technology. Abstract: We report a pull-up type RF MEMS switch using double electrode without elastic deformation of the cantilever involved in the actuation. At a voltage of 4.5 V, reliable actuations are achieved such that the movable lower contact pad is pulled up by the electrostatic force to make contact with the upper pad. At a frequency of 50 GHz, an insertion loss of 0.7 dB and an isolation of 50.7 dB are obtained from the switch. The measured transient times for switch-on and switch-off are 120 and 80 ns, respectively. |
8,158 | Please write an abstract with title: Positioning for User Equipment of a mmWave System Using RSSI and Stereo Camera Images, and key words: Degradation, Base stations, Global navigation satellite system, Millimeter wave technology, Estimation, Position measurement, Cameras. Abstract: In this paper, we propose a positioning method for user equipment of a mobile millimeter wave (mmWave) communication system. In such a system, a blockage is a cause of a disconnection or a serious degradation of communication. Several techniques to control radio links between multiple base stations have been proposed to avoid these problems. These techniques control radio links by a blockage prediction based on images from a depth camera in a base station. However, those techniques require an accurate position of the user equipment (UE) with a precision of several tens of centimeters. There are methods to obtain accurate UE positions, but they are difficult to apply in real environments because they require particular equipment (e.g., high-precision global navigation satellite systems) and acquisition methods of position information from UEs by a communication system. To solve this problem, we propose the UE positioning method using information only on the base station side. Our proposed method estimates a UE position based on temporal variations in images from a stereo camera and the received signal strength indicator (RSSI) by movements of the UEs and objects. We evaluated our method by experiments in an outside environment, and it achieved an average position accuracy of 0.740 m. |
8,159 | Please write an abstract with title: A Supervised Learning Approach for Centralized Fault Localization in Smart Microgrids, and key words: Microgrids, Phasor measurement units, Topology, Current measurement, Transient analysis, Location awareness, Fault detection. Abstract: This article proposes a supervised learning approach for centralized localization of faults in microgrids with radial configuration that can operate in grid-connected or islanded mode. The key concept is to identify faults by learning and analyzing the features of voltage and current disturbances detected by a microgrid central protection unit. Two algorithms are developed that determine fault indices and transient features for simulation-based training, classification, and backup protection purposes. The proposed data-driven approach is effective under high penetration of distributed energy resources (DERs), and is robust under microgrid topology variations. Moreover, it requires few sensors (two for radial structure) and is easy to implement, yet provides high degree of reliability. The performance and accuracy of the developed approach are verified through extensive simulations of low-voltage microgrids that incorporate different types of DERs, including wind and solar photovoltaic systems. |
8,160 | Please write an abstract with title: Research on Fault-phase Selection of New High-Speed Railway Continuous Power Line Based on Wavelet Transform, and key words: Continuous wavelet transforms, Software packages, Power cables, Distribution networks, Rail transportation, Discrete wavelet transforms, Mathematical model. Abstract: On the basis of constructing a new high-speed railway distribution network structure, according to the actual operation of Xi-Cheng passenger dedicated line, a simulation model of power cable continuous line between two distribution stations is built on MATLAB / Simulink platform. Based on this model, the operation status of the system connected with power electronic transformer is simulated and analyzed, and a low-power experimental platform is built for experimental verification. The method of high-speed fault-phase selection of transmission line based on wavelet transform is applied to fault-phase selection of new high-speed railway continuous power line. In this method, the detected transient fault current is transformed into a module component through the phase-mode transformation, and binary discrete wavelet transform (DWT) was carried out on the fault current mode component by using db5 wavelet basis in MATLAB wavelet toolbox, then the maximum modulus was obtained as the phase selection criterion for phase selection. According to the characteristics of the continuous power line and the simulation results, the phase selection criterion is modified and improved. A large number of simulation experiments show that this method can realize phase selection under different fault types, different fault distances and different fault grounding resistance in new high-speed railway continuous power line. |
8,161 | Please write an abstract with title: Method of Equipment Fault Diagnosis Based on Frequent Itemsets Mining, and key words: Training, Correlation, Itemsets, SCADA systems, Power system stability, Prediction algorithms, Power grids. Abstract: With the construction of new power systems, the grid structure is becoming increasingly complex, and the potential factors that cause power grid faults are also increasing. In this paper, frequent itemset mining is used to deeply mine the association relationship between equipment faults, so as to predict the occurrence of equipment faults and improve the stability of power grid operation. Firstly, the correlation feature of equipment faults is to be selected, at the same time, the method of mutual information is used to filter out the main features. Then, the potential correlation relationship between the fault equipment is evaluated and analyzed by establishing a model. Finally, through the correlation analysis of actual data, the results show that this method performs better compared with other algorithms at the respect of the training time and accuracy, which can be used to predict and guide the fault correlation analysis of power grid equipment. |
8,162 | Please write an abstract with title: Angiographic prognosis and diagnosis of heart disease by using unsupervised and supervised Machine Learning techniques, and key words: Diseases, Heart, Measurement, Machine learning, Unsupervised learning, Couplings, Gaussian mixture model. Abstract: The present work provides a detailed analysis of machine learning methods which can successfully be used in discovering and predicting coronary heart disease from datasets containing human body parameters. Unsupervised learning techniques are responsible for detecting patterns linking together medical parameters which result in a common outcome, and our paper details three such approaches: clustering (GMM, hierarchical), outlier detection (KDE, KNN density, KNN-ARD) and association mining. At the same time, supervised learning classifiers will help in understanding the prediction possibilities of such a medical condition, and this has been done by applying and statistically evaluating the performance of logistic regression and artificial neural networks (ANN) against a predictive baseline model. The results of our analysis show that predicting coronary heart disease is a well-suited task for machine learning detection, with small error ranges being achieved even from low-dimension datasets of only a dozen features, provided that the features are relevant and the patient data is well-recorded. |
8,163 | Please write an abstract with title: Implementation of Project-Based Learning in Teaching an Antenna and Wave Propagation Course, and key words: Electrical engineering, Propagation, Conferences, Education, Collaboration, Antenna feeds, Antennas. Abstract: Antenna and Wave Propagation course is regarded as an important course for senior undergraduates or postgraduates majoring in electrical engineering, especially communication engineering. This article presents an implementation of project-based learning in antenna and wave propagation course. A project-based learning component is developed to supplement traditional classroom learning. It motivates the students to apply the textbook theory to real-world engineering problems, allows meaningful collaborations between the students, and boosts students' self-learning capability. Demonstrated by project results and student feedbacks, incorporating project-based learning into traditional classroom learning benefits both student learning outcomes and student personal development. |
8,164 | Please write an abstract with title: HERMES: Hardware-Efficient Speculative Dataflow Architecture for Bonsai Merkle Tree-Based Memory Authentication, and key words: Technological innovation, Nonvolatile memory, Memory management, Throughput, Hardware, Computer crashes, Security. Abstract: Emerging byte-addressable Non-Volatile Memory (NVM) technology, although promising superior memory density and ultra-low energy consumption, poses unique challenges to guaranteeing memory confidentiality, integrity, and crash-consistency. As such, extensive research has been conducted to transparently protect memory security through an FPGA-implemented middleware that effectively deploys encryption, authentication/integrity verification, and replay attack protection. Bonsai Merkle tree (BMT) has been proven to be highly effective in guaranteeing memory integrity and protecting against replay attack. However, when used in a strictly persistent trusted execution environment (TEE), BMT-based memory integrity protection severely bottlenecks memory performance because properly maintaining a BMT results in a deep traversal over the hash tree for every counter update. In this paper, we propose HERMES, a hardware-efficient memory integrity engine specifically designed to deliver a crash-consistent BMT for NVM, capable of processing multiple outstanding counter requests in flight, which significantly improves both latency and throughput of all BMT operations through leveraging an asynchronous dataflow architecture and speculative execution. HERMES incorporates three architectural innovations: (1) a speculative control logic and a speculative temporary buffer dedicatedly designed and deployed at each level; (2) an optimized hardware component verifying all BMT levels in parallel and an adaptive algorithm adapting to caching status of BMT levels; (3) a formalized message format transferred between BMT levels to accommodate both counter operations within a unified architecture where each level is able to adaptively behave. Experimented with Shuhai memory bandwidth benchmark, HERMES achieved up to 7.9x higher throughput and up to 3.5x shorter latency over the state-of-the-art ARES while consuming 2x resource utilization as a tradeoff. |
8,165 | Please write an abstract with title: Faceting and critical current densities of [001] high-angle tilt boundaries in YBCO films, and key words: Critical current density, Yttrium barium copper oxide, Transmission electron microscopy, Superconducting films, Substrates, Scanning electron microscopy, Sputtering, Grain boundaries, Image segmentation, Scattering. Abstract: The [001] high-angle tilt boundaries in YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) thin films deposited on SrTiO/sub 3/ (STO) bicrystal substrates have been studied by Scanning Squid Microscopy (SSM) and transmission electron microscopy (TEM). Generally critical current density across a boundary decreases with increasing misorientation. However, misorientation angle is found to be insufficient to predict the J/sub c/ behavior of a YBCO grain boundary. The two inclination angles of the adjacent grains are found to be important parameters. In two separate cases of same misorientation but different inclinations, the boundaries exhibit drastically different superconducting behaviors and this has been observed by SSM imaging of Josephson vortices. The YBCO film boundary is not an exact copy of the design boundary of the substrate bicrystal template. YBCO boundaries meander due to island formation during film growth. These microscopically wavy boundaries contain straight segments of atomistic facets. Three energetic criteria that affect faceting have been identified. The particular criterion that a facet plane cannot be too deviated from the design boundary plane (/spl phi/<28/spl deg/) explains the strong effect of the design inclination angles on J/sub c/ despite extensive faceting. The original scattered values of J/sub c/ each calculated from individual fluxes of the same design boundary are likely to be a bona fide effect corresponding to individual facet having its own J/sub c/ and /spl lambda//sub j/ values. |
8,166 | Please write an abstract with title: NOC-Based Multiple Low-Order Harmonic Currents Suppression Method, and key words: Harmonic analysis, Power harmonic filters, Large Hadron Collider, Capacitors, Registers, Harmonics suppression, Inductors. Abstract: In a microgrid system, the dc bus contains a significant amount of undesired low-order harmonic currents (LHC) when multiple converters of various types and with nonlinear behavior are connected. To address the issue, this article proposes an iterative control strategy based on a negative-order capacitor (NOC) branch on dc bus. In the proposed method, the reference voltage of decoupling capacitors in the NOC circuit is obtained based on the dc bus current. The voltage difference between the two decoupling capacitors is taken as the control objective, leaving little dc difference between the two capacitors and resulting in maximum LHC suppression ability. To refactor the reference voltage, a singularity points hunting strategy is proposed, helping to reduce the current spike. More importantly, the iterative control strategy is employed in the virtual current loop, decreasing steady-state error from device deviation or control deviation. Finally, an 800 W prototype is built to validate the effectiveness of the proposed method. |
8,167 | Please write an abstract with title: An Experimental Ferromagnetic Wall Climbing and Paint Fixing Robot Control by an Upper Computer with Colour Discrimination and Its Development Prospect, and key words: Automobiles, Image color analysis, Cameras, DC motors, Brushes, Robot vision systems. Abstract: It is an extremely important task to detect and repair the magnetic conductivity walls of large tanks, steel bridges, ship walls and aircraft exterior surfaces in the industrial field. This kind of task is usually carried out in extremely complex environment, which has the characteristics of high labor intensity and dangerous operation. Thus, there is a great demand for robot assistance. The paper describes a kind of corporation robot system, which use a Linux based computer with a camera as upper computer and a Magnetic caterpillar car robot with Arduino inside. With pixel to real distance calculation, upper computer is able to find the path and correctly guide the robot. The combination of magnetic wall climbing robot and upper-computer system can greatly improve the safety and efficiency of engineering operations. In addition, this paper analyses the motion system and the computer system in detail. The result shows that the whole system has the ability to adapt many kinds of magnetic conducting surface, and is able to expand easily. |
8,168 | Please write an abstract with title: Some lessons learned on constructing an automated testbench for evolvable hardware experiments, and key words: Automatic testing, Hardware, Laboratories, Signal generators, Instruments, Adaptive systems, Circuit testing, Guidelines, Frequency domain analysis, System testing. Abstract: A testbench is absolutely essential to conducting evolvable hardware research, particularly if intrinsic investigations are conducted. Although testbench design is straightforward, in practice its construction has numerous pitfalls. This work describes the automated testbench used in the Adaptive Systems Laboratory at Portland State University. We identify the problems we encountered in making the testbench operational and how those problems were resolved. Finally, we offer some guidelines others find useful when constructing their own evolvable hardware testbenches. |
8,169 | Please write an abstract with title: Practice Test 1, and key words: Object recognition, Mobile handsets, Wireless communication, Databases, Companies, Communication cables, Blocklists. Abstract: This chapter provides a complete practice test for the Systems Security Certified Practitioner (SSCP). It covers each of the seven domains on the SSCP exam: security operations and administration; access controls; risk identification, monitoring and analysis; incident response and recovery; cryptography; network and communications security; and systems and application security. When her/she feels well prepared, the practitioner uses the practice test to assess his/her readiness to take the exam. SSCP certification demonstrates he/she has the advanced technical skills and knowledge to implement, monitor and administer IT infrastructure using security best practices, policies and procedures. |
8,170 | Please write an abstract with title: Feedback control of flexible structures with non-uniform rods, and key words: Feedback control, Flexible structures, Structural rods, Control systems, Partial differential equations, Transfer functions, Delay effects, Feedback loop, Damping, Velocity control. Abstract: A new method of noncollocated controller design for non-uniform flexible structures, governed by the wave equation, is proposed. First, an exact infinite dimensional transfer function, relating the actuation and measurement points, with general boundary conditions, is derived. A key element in that part is the existence of time delays due to the wave motion. These delays play a major role in the controller design, which consists of two stages. In the first one, an inner rate loop is closed in order to improve the system dynamic behavior. It uses rate feedback from both ends and leads to a finite dimensional plus delay inner closed loop, which is the equivalent plant for the outer loop. In the second stage an outer noncollocated loop is closed to obtain feedback from the variable of interest. It has the structure of an observer-predictor control scheme to compensate for the response delay. The resulting overall transfer function is second order, with arbitrarily assigned dynamics, plus delay. |
8,171 | Please write an abstract with title: Few-Shot Classification With Intra-Class Unrelated Multi-Prototype Representation and Episode Adaptation Strategy, and key words: Training, Adaptation models, Conferences, Redundancy, Prototypes, Benchmark testing, Task analysis. Abstract: The episode training strategy, which trains models by many episodes to recognize unseen object categories using one or a few samples, is used by many existing approaches to solve the few-shot classification. An episode can be regarded as a classification task for the few-shot classification. However, this training strategy will be tricky when the task feature differences between the training episodes are big. To improve on this shortcomimg, we propose an Episode Adaptation Loss (EAL) to reduce these gaps for optimizing the models efficiently. Furthermore, to enhance the ability of each class feature representation and preserve diversities of the intra-class features, we propose Multi-Prototypical Representations (MPR) and a Multi-Prototype Unrelated Loss (MPUL). In addition, we introduce the multi-prototypes inductive inference as a classification strategy for our method. We evaluate our method on miniImageNet and Fewshot-CIFAR100 benchmarks. Experimental results demonstrate that our method outperforms the baseline approaches. The ablation study validates that the components of the proposed method all provide positive effects on few-shot learning. |
8,172 | Please write an abstract with title: Real-Time Dynamic SLAM Algorithm Based on Deep Learning, and key words: Semantics, Heuristic algorithms, Simultaneous localization and mapping, Visualization, Optical flow, Real-time systems, Feature extraction. Abstract: In the traditional visual simultaneous localization and mapping (SLAM), the strong static assumption leads to a large degradation in the accuracy of visual SLAM in dynamic environments. For this reason, many scholars incorporate semantic segmentation networks into the visual SLAM framework to extract dynamic information in images. However, most semantic segmentation networks consume a lot of computing time due to the large model size, which leads to the algorithm’s inability to meet real-time requirements in practical applications. In this paper, a real-time visual SLAM algorithm based on deep learning is proposed. This novel algorithm is based on ORB-SLAM2, and a parallel semantic thread based on the lightweight object detection network YOLOv5s is designed, which enables us to get semantic information in the scene more quickly. In the tracking thread, an optimized homography matrix module is proposed, which utilizes semantic information to optimize and solve the homography matrix so that we can calculate a more accurate optical flow vector. In the optical flow module, the semantic information is used to narrow down the calculation range of the optical flow value to improve the real-time performance of the system, and the dynamic feature points in the image are removed by the optical flow mask to improve the accuracy of the system. Experimental results show that compared with ORB-SLAM2, DynaSLAM, and other excellent visual SLAM algorithms, this algorithm can effectively reduce the absolute trajectory error of visual SLAM in dynamic environments. Compared with other deep learning-based visual SLAM algorithms, the real-time performance of this algorithm is also significantly improved. |
8,173 | Please write an abstract with title: Detailed FEM-based Analysis of Vibration in a 3-phase Switched Reluctance Motor and its Experimental Validation, and key words: Vibrations, Accelerometers, Analytical models, Simulation, Hysteresis motors, Switched reluctance motors, Stators. Abstract: This paper deals with FEM-based electro-magnetic and mechanical analysis on a 3 phase, 1 kW, 48 V, 3000 rpm switched reluctance motor laboratory prototype. At first the modal analysis of the individual parts of the motor namely, the stator, rotor, shaft and the frame has been done in order to obtain the dominant natural modes of vibration. Then the static structural analysis is done to determine deformation due to its self-weight. A coupled simulation of electro-magnetic and transient structural is finally performed to estimate the motor deformation during the usual operation. Experiments have been performed to validate the simulation results. A MEMS-based accelerometer has been used to measure the instantaneous acceleration of the motor. The recorded data has been processed to obtain the deformation amplitude which is found to be in good agreement with the FEM-based simulation results. |
8,174 | Please write an abstract with title: Property-restoral algorithms for blind equalization of OFDM, and key words: Blind equalizers, OFDM, Adaptive equalizers, Adaptive filters, Least squares approximation, Convergence, Signal restoration, Adaptive algorithm, Bandwidth, Statistics. Abstract: Adaptive blind equalization for OFDM can be difficult due to its nearly Gaussian marginal density. OFDM has unique properties, however, including constant mean block energy and zero-padded or circular-prefix guard bands, that allow blind equalization. The hybrid LMS/VCMA algorithms introduced here blindly restore the guard-band properties while maintaining a constant mean block energy. These simple, low-complexity adaptive algorithms demonstrate rapid convergence in simulations. |
8,175 | Please write an abstract with title: Reliable Transmission of Critical Packets in IEEE 802.15.4-based Body Area Networks, and key words: Wireless Body Area Networks, IEEE 802.15.4, Markov Chain, Backoff Stage, Slotted CSMA-CA Algorithm, Critical Packet, Reliable Transmission. Abstract: In this paper, we propose a mechanism to ensure reliable transmission of critical packets in Wireless Body Area Networks (WBANs). As WBANs are responsible for real-time health monitoring, thus, high success rate is necessary in packet transmissions. Especially, packets that possess critical health information must be dealt with utmost priority. To ensure this, in this work we express the probability of successful packet transmission as a function of maximum number of backoff stage - an important MAC parameter - so that we can judiciously tune its value to achieve maximum transmission reliability for critical nodes. The IEEE 802.15.4 is used as the underlying communication standard. We use a simple two-dimensional Markov chain to model the slotted CSMA-CA based channel access mechanism of IEEE 802.15.4, which acts as the basis of the whole work. We compare the proposed approach with random assignment of maximum number of backoff stage to the body sensor nodes and show that judicious tuning of this value yields 25% improvement in reliable packet transmission, in comparison with random assignment. |
8,176 | Please write an abstract with title: Development Planning Method of Weapon Equipment System Based on Dynamic Game, and key words: Procurement, Analytical models, Costs, Systematics, Weapons, Decision making, Games. Abstract: Aiming at the feature of weapon equipment systematic confrontation in modern war, this study analyzed the problems of weapon equipment system planning and development from the perspective of rivalry game, provided its analysis elements, established the dynamic game framework of weapon equipment system's development planning, set up the dynamic game model of incomplete information weapon equipment's development planning, and gave an example analysis. |
8,177 | Please write an abstract with title: Robust Seventh Order Complex Filter Controller for PV-BES System with Seamless Grid Synchronization, and key words: Total harmonic distortion, Power system stability, Steady-state, Synchronization, Phase locked loops, Power harmonic filters, Standards. Abstract: This paper presents a robust and comprehensive seventh order complex filter (7thOCF) based control for solar photovoltaic (SPV) based nonconventional energy system (NES) with seamless changeover proficiency from different modes i.e, from the grid connected (GC) to an islanded (IL) mode. In GC mode of NES operation, this conquers the problem of poor grid conditions. The NES has a capability to feed the load both in GC and IL modes and it operates smoothly during mode shifting between modes. The unknown disturbances of NES in grid connected mode are taken care by the 7thOCF. With the help of this algorithm, the quadrature sinusoidal fundamental component (Q-SFC) is extracted. For control of the NES in an islanded mode, a control algorithm is used which based on the resonant controller plus proportional resonant (R+PR) control. A dual seventh order complex filter (D7thOCF) is combining to phase locked loop (PLL) for smooth synchronization and resynchronization to the grid. Without affecting the stability, it improves performance of the system. Simulated results are presented to demonstrate the performance of the NES and validate the robustness and effectiveness of control schemes. Moreover, total harmonic distortions (THDs) of the load and grid parameters are in the limits of the IEEE-519 standard. |
8,178 | Please write an abstract with title: Feedback Control for a Piezoelectric-Resonator-Based DC-DC Power Converter, and key words: Resistance, Time-frequency analysis, Voltage measurement, DC-DC power converters, Switches, Zero voltage switching, Control systems. Abstract: Piezoelectric resonators (PRs) are promising alternatives to magnetic components for miniaturized power conversion. PR-based converter topologies and operating modes are capable of high efficiencies with behaviors such as zero voltage switching, PR soft charging, and all-positive instantaneous power transfer. However, closed-loop control of such behaviors is challenging because it requires precise modulation of frequency, duty cycle, dead times, and phase shift between half-bridges. This paper presents a simple control algorithm for a class of PR-based dc-dc power converters employing six-stage switching sequences and topologies with two half-bridges. The proposed control method regulates the converter’s output voltage while maintaining its high-efficiency behaviors. Further, highlevel aspects of converter dynamics can be modeled with only two state variables. We validate this control strategy in a microcontroller-based experimental prototype. |
8,179 | Please write an abstract with title: Utilizing Differential Evolution for an Automated Compact Model Parameter Extraction, and key words: Semiconductor device modeling, Semiconductor device measurement, Computational modeling, Fitting, Manuals, Time measurement, Task analysis. Abstract: Parameter extraction is a challenging task, as it searches for a solution inside a high dimensional plus non-convex space. To be able to apply well known gradient based optimizers, the problem is dissected into multiple simpler yet intertwined tasks, which yields a complex and manual labour intensive procedure. On the contrary to gradient based methods, genetic algorithms perform excellent on global search problems, which eliminates the need for such a sophisticated workflow. In this paper a highly automated methodology is presented that is capable of replacing the standard manual extraction sequence for the BSIM MOSFET compact model. Due to its superior extreme finding behaviour, the Differential Evolution algorithm is applied in combination with a special error metric to ensure a high fitting quality, in all regions of the output and transfer curves. Repeatably good results for 20k measurement points are obtained, with a reduction of factor 10 in total fitting duration, while coincidentally consuming mostly computation instead of manual labour time. |
8,180 | Please write an abstract with title: Fourier synthesizer using left-handed transmission lines, and key words: Synthesizers, Transmission lines, Power harmonic filters, Power transmission lines, Transmission line theory, Varactors, Phase shifters, Shunt (electrical), Inductors, Signal generators. Abstract: We propose an arbitrary waveform generator based on Fourier synthesis from left-handed (LH) transmission lines. Cascaded varactors and shunt inductors are used to construct the LH transmission line, which can be used as an efficient harmonic generator when driven with a large signal, and as a linear phase shifter when driven with a small signal. By controlling the amplitude and phase of each harmonic, and combining them together, we can generate pulses of arbitrary waveforms. |
8,181 | Please write an abstract with title: Optimal switching control via direct search optimization, and key words: Optimal control, Switched systems, Control systems, Switches, Vehicle dynamics, Optimization methods, Chemical engineering, Difference equations, Logic, Computer networks. Abstract: We demonstrate in this paper that for switched systems the optimal switching time instants and the optimal control policy can be solved readily by direct search optimization. General problem formulation and numerical procedures are presented together with two demonstrative examples previously considered in the literature using other numerical solution methods. |
8,182 | Please write an abstract with title: Implicit similarity: a new approach to multi-sensor image registration, and key words: Image registration, Image sensors, Robustness, Magnetic resonance imaging, Gradient methods, Computer science, Sensor phenomena and characterization, Remote sensing, Biomedical imaging, Computed tomography. Abstract: This paper presents an implicit similarity-based approach to registration of significantly dissimilar images, acquired by sensors at different modalities. The proposed algorithm introduces a robust matching criterion by aligning the locations of gradient maxima. The alignment is formulated as a parametric variational optimization problem, which is solved iteratively by considering the intensities of a single image. The location of the maxima of the second image's gradient are used as initialization. We are able to robustly estimate affine and projective global motions using 'coarse to fine' processing, even when the images are characterized by complex space varying intensity transformations. Finally, we present the registration of real images, which were taken by multi-sensor and multi-modality using affine and projective motion models. |
8,183 | Please write an abstract with title: The shipborne radar antenna pattern at over-horizon object observation, and key words: Radar antennas, Aperture antennas, Radar tracking, Terrestrial atmosphere, Radar detection, Radar clutter, Antennas and propagation, Switches, Fluctuations, Meteorological radar. Abstract: The paper considers the possibilities for shipborne radar (/spl lambda/ = 4.5 cm) to detect over-the-horizon objects in higher refraction conditions. It is shown that, due to antenna pattern adaptation to high refraction coefficient gradients in the troposphere lower layers, the radar receiver output signal-to-noise ratio can increase by 20-23 dB. |
8,184 | Please write an abstract with title: Frequency chirping in LiNbO/sub 3/ electrooptic modulator, and key words: Frequency, Chirp, Electrooptic modulators, Finite difference methods, Dispersion. Abstract: Frequency chirp in LiNbO/sub 3/ electrooptic modulators is assessed and numerically evaluated using the FDTD method. Affecting parameters and suggested configurations are highlighted and finally, its influence is illustrated by propagating frequency chirped pulses in a dispersive fiber. |
8,185 | Please write an abstract with title: A ubiquitous photo mapping considering users' lines of sight, and key words: Cameras, Information retrieval, Global Positioning System, Layout, Prototypes, Uniform resource locators, Image storage, Information science, Data visualization, Data structures. Abstract: This paper proposes a new framework for mapping and retrieving photographs, maps and cyberspaces to each other. Our target photographs are enhanced with spatial metadata such as geographic coordinates where they were taken and directions where they focused on. We assume photographs having such spatial metadata become popular. In a common framework, such photographs are mapped to their viewpoints by using their location information generated by GPS. We think this framework has less function for practical spatial queries. For example, even if a photograph is mapped to a certain point on a map, a scene of the point may not be shown in the photograph. It may show a different direction than user wants to see. A problem is that though locations or objects shown in photographs are important for users, viewpoints are not positions of them but positions of cameras from which photographs were taken. We therefore map each photograph to a vector from its viewpoint to its gazing point, and named the vector as photo vector. A prototype system based on our framework provides functions such as handling advanced spatial queries for retrieving photographs, visualizing how many photographs show each location, and mapping text labels having URLs and geographic coordinates to the appropriate positions on photographs. In this framework, photographs, maps and cyberspaces are mapped to each other. |
8,186 | Please write an abstract with title: A distributed privacy preserving framework for the Smart Grid, and key words: Smart meters, Cryptography, Privacy, Smart grids, Data privacy. Abstract: Smart grid is envisioned to be deployed on cyberinfrastructure, which makes it vulnerable to cyberattacks. Studies have shown that by accessing the metering data, behavioral patterns of the customers can be derived by analysis. Therefore, to protect the privacy of the customers, it is important to develop privacy-preserving protocols and frameworks. Various studies in the smart grid domain address the privacy issue, but the techniques either have a high computational overhead or they are dependent on a single dedicated aggregator, making them prone to single points of failure. In this paper, a framework based on Shamir's secret sharing is proposed to address the above-mentioned issues. The framework is designed to prevent dedicated aggregators and the electrical utility from linking the aggregated reading to a specific smart meter. The security of the proposed framework is analyzed with respect to different attack scenarios. |
8,187 | Please write an abstract with title: Design and Operational Optimization of CCHP Systems Using a Hybrid Method Based on MILP, and key words: Linear programming, Optimization, Trigeneration, Search methods, IEEE transactions, Hybrid power systems, Gases. Abstract: Combined Heat and Power (CCHP) systems provide electricity, chilled water, and steam for industries and buildings. The choice of the equipment used as well their operation to meet the energy demands depends on a series of factors, among them investment costs, fuel and electricity tariffs, seasonality of loads, and maintenance costs. A challenge faced in the optimization of those systems using Linear Programming is the discrete and non-uniform availability of equipment on the market. Satisfactory results can be obtained using an exhaustive search method coupled with Linear Programming, although this requires a high computational effort. On the other hand, the use of MILP is fast, but the equipment rated power must be uniformly available, with is not realistic. In this paper, we compare two methods for optimizing CCHPs: MILP (Mixed Integer Linear Programming), which used only 0.16% of the original time but with an imprecision of 8%; and a hybrid method of mixing MILP, Selective Search and Linear Programming, which used 4.2% of the original time without loss of precision. The results showed that the hybrid method has the same precision as the exhaustive search method, but with a much shorter processing time. |
8,188 | Please write an abstract with title: Architecture reviews: practice and experience, and key words: Project management, Knowledge management, Management training, Computer architecture, Software development management, Software quality, Scheduling, Engineering management, Knowledge engineering, Software design. Abstract: Architecture reviews have evolved over the past decade to become a critical part of our continuing efforts to improve the state of affairs. We use them to identify project problems before they become costly to fix and to provide timely information to upper management so that they can make better-informed decisions. It provides the foundation for reuse, using commercially available software, and getting to the marketplace fast. The reviews also help identify best practices to projects and socialize such practices across the organization, thereby improving the organization's quality and operations. |
8,189 | Please write an abstract with title: Reinforcement Learning-Based Adaptive Optimal Fuzzy MPPT Control for Variable Speed Wind Turbine, and key words: Wind speed, Wind turbines, Adaptive systems, Heuristic algorithms, Adaptation models, Uncertainty, Neural networks, Fuzzy logic, Reinforcement learning, Permanent magnet motors, Synchronous generators. Abstract: A reinforcement learning-based adaptive optimal fuzzy controller is proposed for maximum power point tracking (MPPT) control of a variable-speed permanent magnet synchronous generator-based wind energy generation system. The algorithm consists of a critic, an adaptive optimal fuzzy controller, and an adaptive optimal fuzzy estimator. The critic is built based on an adaptive neuro-fuzzy inference system (ANFIS) network instead of the neural network as normal to reduce the computation. The error between the system output and the estimator output is used as the input of the critic. In addition, the critic is used to calculate the update law for the parameters of the adaptive optimal fuzzy controller and adaptive optimal fuzzy estimator based on minimizing the input error function. Moreover, the proposed control scheme is output feedback instead of state feedback, which does not require a system model as well as system parameters, so the system is robust to uncertainties and external disturbances. Besides, the stabilization proof is accomplished by using the Lyapunov stability theorem for the closed-loop system and the convergence of the update law. Finally, the effectiveness of the proposed reinforcement learning-based adaptive optimal fuzzy control scheme is verified through simulation with various scenarios such as step wind speed, random wind speed, and system parameter variations. Also, the comparisons with other control schemes in the state-of-art (neural network reinforcement learning based adaptive optimal fuzzy controller, PI controller) are executed to demonstrate the advantages of the proposed control scheme. |
8,190 | Please write an abstract with title: Field evaluation of ADCP refinements for profiling shallower waters, and key words: Sea measurements, Rivers, Velocity measurement, Current measurement, Transducers, Instruments, Boats, Fault location, Frequency, Bandwidth. Abstract: During recent years, RD Instruments (RDI) has received. increasing requests for the Acoustic Doppler Current Profiler (ADCP) to be able to operate in shallower water. Providing a well-resolved velocity profile in water depths of 0.6 m required several refinements of prior ADCP capabilities. These included creating an ADCP transducer (ZedHed/spl trade/) that has reduced ringing, bottom tracking at lower altitudes, increasing the pinging rate, and operating with smaller cell sizes in both slower and faster flows. This paper describes results from a field evaluation of these engineering developments. Data were collected by colocated 1200 kHz ADCPs during a flood/ebb cycle in a shallow, tidally affected, coastal lagoon north of San Diego, California. We installed in the lagoon bed a standard ADCP operating with a high ping rate (Mode 12). A ZedHed ADCP, set to work with high precision (Mode 11), was mounted in an Oceanscience's tri-hulled River Boat. Modes 11 and 12 were demonstrated to provide the capability to profile water depths of 0.6 m when used together with the ZedHed transducer (and the shallow bottom tracking capability for moving surveys). These modes were shown to meet noise specifications even for the small cell sizes required for profiling shallow water. An interesting possibility revealed in this work was the prospect of using Error Velocity in Mode 11 as a gauge of natural variability in turbulence and mixing studies. |
8,191 | Please write an abstract with title: Combined state estimation and A/D conversion with multipath tree coders, and key words: State estimation, Quantization, Control systems, State feedback, Signal design, Analysis of variance, Source coding, Robustness, Performance analysis, Optimal control. Abstract: Concepts of optimal source coding, as developed in rate-distortion theory, are applied to the problems of feedback signal quantization and of process state estimation from quantized measurements. Tree coders are shown to have a real-time capability for providing a combined solution to these problems. The multipath feature of the estimator memory provides the additional benefit of increased robustness to bad data and unmodeled disturbances. Simulation results for an example control system indicate that significant performance improvements are possible with multipath quantizer/estimators as compared to the corresponding single path versions. |
8,192 | Please write an abstract with title: Modelling and Prediction of Injection Molding Process Using Copula Entropy and Multi-Output SVR, and key words: Support vector machines, Computer aided software engineering, Conferences, Predictive models, Injection molding, Entropy, Product design. Abstract: Optimization and parameter adjustment of an injection molding (IM) process depend largely on a good modelling and prediction of industrial process, which has been received considerable attention in recent years. However, IM process is a typical multivariate production process with multiple product quality indices. It poses a great challenge for multi-output quality prediction problem to select key process variables as input with good interpretability. This study proposes a multivariate quality prediction method for IM process using copula entropy (CE) and multi-output support vector regression (MSVR). First, copula entropy is employed to characterize the association relationships between each process variable and the set of quality indices, thus key process variables can be selected by ranking CE. Then, the quantitative relationship between key process variables and quality indices is established by MSVR. Finally, the proposed method is tested by the experiment on a real IM process dataset. This study will provide an important reference for modelling and prediction of IM process and other multi-output problems. |
8,193 | Please write an abstract with title: Empirical Review of Automated Analysis Tools on 47,587 Ethereum Smart Contracts, and key words: Smart contracts, Computer bugs, Debugging, Blockchain, Tools, Testing, Software engineering. Abstract: Over the last few years, there has been substantial research on automated analysis, testing, and debugging of Ethereum smart contracts. However, it is not trivial to compare and reproduce that research. To address this, we present an empirical evaluation of 9 state-of-the-art automated analysis tools using two new datasets: i) a dataset of 69 annotated vulnerable smart contracts that can be used to evaluate the precision of analysis tools; and ii) a dataset with all the smart contracts in the Ethereum Blockchain that have Solidity source code available on Etherscan (a total of 47,518 contracts). The datasets are part of SmartBugs, a new extendable execution framework that we created to facilitate the integration and comparison between multiple analysis tools and the analysis of Ethereum smart contracts. We used SmartBugs to execute the 9 automated analysis tools on the two datasets. In total, we ran 428,337 analyses that took approximately 564 days and 3 hours, being the largest experimental setup to date both in the number of tools and in execution time. We found that only 42% of the vulnerabilities from our annotated dataset are detected by all the tools, with the tool Mythril having the higher accuracy (27%). When considering the largest dataset, we observed that 97% of contracts are tagged as vulnerable, thus suggesting a considerable number of false positives. Indeed, only a small number of vulnerabilities (and of only two categories) were detected simultaneously by four or more tools. |
8,194 | Please write an abstract with title: Lightweight Bird's Nest Location Recognition Method Based on YOLOv4-tiny, and key words: Training, Power transmission lines, Computational modeling, Poles and towers, Tools, Birds, Prediction algorithms. Abstract: Activity around transmission lines after bird nesting poses a threat to the safe operation of the power grid. Identifying bird nests in transmission lines and towers is the key to preventing wading bird failures. With the development and change of deep learning and patrol mode, the accuracy and speed of bird's nest recognition algorithm are challenged. To address this challenge, this paper presents a bird's nest location recognition method based on YOLOv4-tiny. YOLOv4-tiny, a lightweight version of YOLOv4, consists of a backbone network, FPN, and YOLO head with 13×13 and 26×262 prediction scales. The YOLOv4-tiny algorithm extracts the features of the input bird's nest image data to realize the positioning recognition of the bird's nest. This paper chooses the open source Darknet framework as a tool, which combines Loss and AP curves in the visualization training process. The results show that the model accuracy of YOLOv4-tiny algorithm can reach 77.20%, and the inference speed on the edge computing platform Jetson Xavier NX can reach up to 50.39 FPS. The method proposed in this paper can meet the requirements of real-time target detection in both speed and accuracy, and has a good application prospect. |
8,195 | Please write an abstract with title: A study of injection pulling and locking in oscillators, and key words: Injection-locked oscillators, Clocks, Nonlinear equations, Transceivers, Phase noise, Frequency domain analysis, Radio frequency, Vibrations, Humans, Circuits and systems. Abstract: This paper presents an analysis that confers new insights into injection pulling and locking of oscillators and the reduction of phase noise under locked condition. A graphical interpretation of Adler's equation predicts the behavior of injection-pulled oscillators in time and frequency domains. An identity derived from the phase and envelope equations expresses the required oscillator nonlinearity across the lock range. |
8,196 | Please write an abstract with title: Effect of randomness in the distribution of impurity ions on FET thresholds in integrated electronics, and key words: Impurities, FETs, Fluctuations, Threshold voltage, Doping, Electric breakdown, Electrodes, Atomic layer deposition, Transistors, Space charge. Abstract: A model of the effect of random fluctuations in the number of impurity atoms in the depletion layer of a field-effect transistor (FET) is presented and analyzed. It is conducted that the range of space charge per unit area that must be anticipated on a chip containing N FET's each of area A is /spl Delta/S=q(2 ln N)/SUP 1/2/A/SUP -1/4/n~/SUP 1/2/. n~ is the doping level of the substrate. |
8,197 | Please write an abstract with title: Impact of VCO and PLL Phase Noise on Distributed Beamforming Arrays With Periodic Synchronization, and key words: Array signal processing, Phase noise, Oscillators, Synchronization, Phase locked loops, Wireless communication, Phased arrays. Abstract: Distributed beamforming between separate wireless nodes in a distributed antenna array requires significant coordination of the relative electrical states of the systems to achieve and maintain a phase-coherent state. A principal factor impacting distributed phase coherence is the relative stability of the local oscillators on each node. Ensuring a coherent state requires the distribution of a reference frequency such that all nodes are operating on the same basis frequency. To support distributed beamforming, the reference frequency must furthermore be distributed wirelessly, typically using a phase-locked loop (PLL) on the secondary nodes. In large arrays, the wireless link used for frequency distribution will have limited capacity, necessitating intermittent updates during which the oscillators are locked, and between which their frequencies will drift. The stability of the oscillator therefore plays an important role in the overall performance relative to the update time. In this paper, we discuss the sources of phase noise generated by the reference oscillator and the PLL, and analyze the impacts of phase noise and update interval on distributed beamforming performance. We provide a framework for analyzing distributed beamforming performance from oscillator and PLL parameters in general, and we analyze beamforming performance for two specific cases using nominal high-stability and low-stability voltage-controlled oscillators, with a parametric comparison between their impact on beamforming performance. |
8,198 | Please write an abstract with title: A low power, polyimide valved micropump for precision drug delivery, and key words: Polyimides, Micropumps, Drug delivery, Valves, Packaging, Micromechanical devices, Pharmaceutical technology, Hydraulic actuators, Bonding, Energy consumption. Abstract: We present a microfabricated pump designed for low flow-rate, implantable drug infusion. The positive displacement type micropump is actuated by a precision linear stepper fabricated using watch-making technology and incorporates two polyimide check-valves which were fabricated using photolithography. Two check-valve die are juxtaposed, bonded and subsequently packaged using PDMS bonding techniques. The design was implemented in order to meet the three major challenges that still face implantable micropumps; low power actuation, debris tolerant valves, and packaging. |
8,199 | Please write an abstract with title: An Accurate Subthreshold Analytical Model for Black Phosphorus Heterojunction Dopingless Tunneling Field-Effect Transistors, and key words: Analytical models, TFETs, Dielectric constant, Logic gates, Heterojunctions, Tunneling, Phosphorus. Abstract: This paper presents an accurate subthreshold analytical model for black phosphorus heterojunction dopingless tunneling field-effect transistors (HD-TFET). At first, the center potential is derived by solving Poisson's equation with ingeniously developed boundary conditions, which the electrical field are derived from this center potential. Finally, the subthreshold drain current model of black phosphorus heterojunction dopingless TFET is developed using maximum generation rate considering the local minimum effect in the device structure energy band diagram. The proposed model is investigated for the channel length, gate dielectric constant and gate oxide thickness variation. To ensure the performance of the developed model, the model results are compared and validated with the TCAD simulation results. The modeled results show the close agreement with the TCAD simulation results without the need of fitting parameters. It was confirmed that the model is able to correctly predict most of the physical phenomena occurring inside the black phosphorus heterojunction dopingless TFET. |
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