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21,300 | Please write an abstract with title: Payout Decision pre- and during COVID-19: Evidence from Bahrain, and key words: COVID-19, Smoothing methods, Companies, Stock markets, Stability analysis, Pandemics, Investment. Abstract: There are several significant decisions taken during the lifespan of any firm, payout decision is no doubt a critical one among them. In this paper, we first examine the payout decision and dividend smoothing of firms listed on Bahrain Bourse during the period 2017–2019. Second, we investigate whether the payout decision of Bahraini firms has been affected by COVID-19 by utilizing data from the first two quarters of 2020. The findings show that non-financial firms have a higher percentage of dividends payers and smooth dividends compared to financial firms during the pre-COVID-19 period. Furthermore, the payout decisions of both types of firms were relatively affected by COVID-19. |
21,301 | Please write an abstract with title: Analytic signal processing in music computation, and key words: Signal analysis, Signal processing, Multiple signal classification, Music, Signal synthesis, Instruments, Production, Additives, Digital signal processing, Power engineering computing. Abstract: Digital synthesis of music has led to the consideration of models other than the usual additive (Fourier) synthesis of waveforms. One of these methods, based on the FM equation, has been found to be of particular value due to its easy implementation and the richness and evolutionary character of its harmonic structure in time. Any useful synthesis procedure should be accompanied by a corresponding analytic procedure. In this paper we lay the foundations for such a procedure based on the discrete Hilbert transform. |
21,302 | Please write an abstract with title: Entrepreneurship in Islamic Financial Technology Products: Evidence from the Kingdom of Bahrain, and key words: Systematics, Law, Instruments, Finance, Banking, Market research, Information technology. Abstract: The digital financial products applied and become legal and regulatory frameworks and some are trying to gain legal status to gain more comprehensive access to business and finance. Financial technology is invading all banking and financial aspects. Islamic Fin-Tech (i-Fin-Tech) is becoming a new trend in the recent industry studied due to the importance of Islamic finance and banking sector. This study aims to Introduce the Islamic fin-tech products that are offered to a market in the Kingdom of Bahrain. This review studies decentralized digital financial products in payment and financing, in addition to trading and investment, and reveals decentralized digital financial products in asset management and insurance. This study uses the qualitative research method, especially by reviewing the published research on previous studies that clarified the essential Islamic financial products used in banks. In addition, this study relies on secondary data, especially reports published by Islamic banks, which show the distinctive products they offer to customers, performing a systematic literature review, the guidelines are significant in encouraging researchers, which are characterized as simulating the technical development of Islamic finance in the era of digital technology. The results showed that Islamic banks are still seeking to benefit from modern technologies by adapting their financing instruments by industry and financial engineering to create products Islamic financial services are up to the challenges of the digital world. This study recommends focusing on information technologies and development and the trend towards digital preparation. |
21,303 | Please write an abstract with title: A Unified Approach to Quantitatively Measure the Similarity of Computer Science Units in Australia, and key words: Taxonomy, Accreditation, Education, Guidelines, Australia, Area measurement, Measurement units. Abstract: Research Full paper - Computer Science (CS) education is increasingly becoming popular across the globe. With the increased popularity of CS and Information and Communications Technology (ICT) courses, the ability to measure the similarity/distance between units can aid the decision-making process of education providers during learning path recommendations, evaluating unit exemptions/advanced standings, etc. The ability to quantitatively measure the similarity of two units will assist decision-making processes which are otherwise likely to be tedious and time-consuming. Therefore, in this work, we explore how to quantitatively measure the similarity/distance between two CS/ICT units, in an Australian setting. In this study, we utilize data from multiple CS/ICT courses offered by two Australian education providers. The data is generated as a result of the Australian Computer Society's (ACS) course accreditation process during which each unit of a course is mapped into multiple knowledge areas. We measured the similarity between units in terms of their coverage of the knowledge areas using multiple distance measures. Our work is novel in examining a quantitative measure of unit similarity, by introducing a unified approach across education providers that follow the ACS course accreditation process. |
21,304 | Please write an abstract with title: A bibliography of Information Theory (communication theory-cybernetics) (Second supplement), and key words: Bibliographies, Information theory, Abstracts, Telecommunications, Frequency, Speech analysis, Game theory, Optical noise, Psychology, Bandwidth. Abstract: The original bibliography, of which this is a second supplement, appeared in IRE TRANS., PGIT-2; November, 1953. First supplement appeared in vol. IT-l, pp. 31-47; September, 1955. THis supplement covers eleven major topics with additional minor topics included. The bibliographiy covers the following: I. General Theory; II. a) Bandwidth and Transmission Capacity, Time - Frequency Uncertainty; b) Signal-to-noise Ratio (SNR); c) Instantaneous Frequency; d) Analytical Signals; III. Definition, Relation with Statistical Mechanics, Philosophy; IV. Correlation Prediction, Filtering, Storage; V. a) Radar; b) Radionavigation; VI. a) Speech; b) Hearing; c) Vision; d) Linguistics, Semantics; VII. a) Other Biological Applications (Cybernetics and the Nervous System); b) Human Engineering; c) Group Communication and Learning; VIII. Television; IX. a) Miscellaneous Applications; b) Games; c) Optics; d) Servomechanisms; X. Mathematics: a) Statistics; b) Games (Theory); c) Relay-Algebra, Reliability; d) Noise Analysis; XI. Pulse Modulation, Multiplex, and Coding. |
21,305 | Please write an abstract with title: Radio, concerts and the future of music distribution, and key words: Multiple signal classification, Internet, Law, Legal factors, Business, Cultural differences, Broadcasting, Marketing and sales, Companies, Monitoring. Abstract: Internet has undoubtedly changed the prerequisites for global music distribution once for all. After years of skepticism, clinging to old business models and pirate hunt on P2P networks, the record industry has reluctantly begun to embrace the new channel for marketing and distribution of cultural content. But what do we know about music consumption on P2P networks? Does it coincide with the variety of cultural content in traditional media channels? This work describes the differences in cultural content on P2P networks, concerts and traditional broadcasted media based on comprehensive data on theoretic rage of choice, air play and requested music at P2P services. The study also describes some of the changes in business models that have already taken place. The study concludes among all that legal download services might reduce the present dominance of the big five major record companies in the long run. |
21,306 | Please write an abstract with title: The Research on Multi-Dimensional Evaluation Index System of Distribution Network Loss, and key words: Power demand, Distribution networks, Radar, Transformers, Power grids, Planning, Indexes. Abstract: At present, the evaluation of regional distribution network loss usually uses a single line loss rate index as the evaluation standard. Comprehensively considering factors such as the distribution grid structure, equipment status, power consumption structure and other factors, this paper establishes a multi-dimensional evaluation index system of the distribution network line loss from three aspects as line loss rate, power grid operation and planning, line and transformer equipment. Taking the line loss situation of the distribution network in two regions of a province as an example, the evaluation index system and corresponding evaluation method are used for evaluation. The calculation example shows that the constructed index system can comprehensively and effectively evaluate the overall situation and weak links of the regional distribution network line loss, thus guiding the direction of regional distribution network loss reduction. |
21,307 | Please write an abstract with title: Novel Sawtooth Structure Loading to Mitigate Mode Competition in a 346 GHz Backward Wave Oscillator, and key words: Loading, Stability analysis, Circuit stability, Vacuum electronics, Copper, Integrated circuit modeling, Oscillators. Abstract: A novel approach to mitigate mode competition and improve stability in a 346 GHz Backward Wave Oscillator (BWO) by loading a copper sawtooth slow wave structure (SWS) is proposed. The effects of mode competition, and the sawtooth structure loading effects are discussed. CST simulation has been used to verify the analysis and test of the stability of those circuits. |
21,308 | Please write an abstract with title: Markovian performance analysis of a synchronous optical packet switch, and key words: Performance analysis, Optical packet switching, Optical switches, Optical fiber networks, Analytical models, Performance loss, Optical losses, Telecommunication traffic, Traffic control, Optical design. Abstract: Switch architectures applicable to fixed-length optical packet networks is studied and we compare their performance in terms of packet loss ratio. We propose analytical models of these switches (as discrete time Markov chains) and we compare their performance with those obtained by simulation, varying statistical properties of incoming traffic. We show that Markovian models of future optical architectures can be applied as a tool to studies of network design. |
21,309 | Please write an abstract with title: Design of High-Speed Driver Circuits Based on Thick Film Technology, and key words: Charge coupled devices, System performance, Oscilloscopes, Detectors, Thick films, Cameras, Telecommunications. Abstract: In order to improve system integration without compromising system performance, this paper presents the design and implementation of driver circuits of a TDI CCD detector using in a remote sensing satellite. The capacitive loads of the CCD detector up to 4 nF are indispensable for the present cameras. The driver circuits take up too much area and space of PCB board for the excessive number and variety of CCD detector driving signals. It is a challenge that designs these high-speed driver signals since drive large capacitive loads while meeting the rise and fall time requirements. This paper presents the design and test results from CCD drivers. Based on thick film technology, the integration of the discrete driver devices circuit reduces the PCB area to 33% than the convention PCB area. In this paper, the design of driving circuit and the selection of driving components are presented in detail. The CCD detector and driver circuits are placed in flex-rigid PCB. In the experiment, the output signal of the module integrated with the thick film measured by the oscilloscope completely meets the requirement of the TDI CCD detector. |
21,310 | Please write an abstract with title: Subject-Dependent Emotion Recognition System Based on Multidimensional Electroencephalographic Signals: A Riemannian Geometry Approach, and key words: Covariance matrices, Electroencephalography, Manifolds, Transfer learning, Feature extraction, Emotion recognition, Symmetric matrices. Abstract: Emotion recognition plays an important role in human computer interaction systems as it helps the computer in understanding human behavior and their decision making process. Using Electroencephalographic (EEG) signals in emotion recognition offers a direct assessment on the inner state of human mind. This study aims to build a subject dependent emotion recognition system that differentiate between high and low levels of valance and arousal, using multidimensional EEG signals. Our system offers a transfer learning- minimum distance to Riemannian mean (TL-MDRM) framework. In this work, we perform two pre-processing stages. In the first stage, we analyze the EEG signals to investigate their non-Gaussianity and determine the most appropriate signal distribution. Using several statistical and goodness of fit tests, T-distribution was found to be the most appropriate distribution. Covariance matrix estimations plays a crucial step in manifold learning technique, based on the most suitable signal distribution the covariance matrix estimation technique is chosen. In the second stage, we perform transfer learning to deal with cross-session variability by generating a unique reference point for each participant and performing affine transformation for the covariance matrices on the symmetric positive definite (SPD) manifold around this point. The results show that, TL process improved the performance even when assuming Gaussian distribution, while assuming T-distribution with TL improved the performance further. |
21,311 | Please write an abstract with title: A hybrid control strategy for capturing cognitive processes in virtual reality (VR) in a natural and efficient way, and key words: Cognitive processes, Navigation, Tracking, Virtual environments, Aerospace electronics, Hardware, Software. Abstract: When using virtual reality (VR) to study cognitive processes, the user’s sensory input and motor output in the virtual setting should closely resemble the actual physical signals. For extended VR settings, in which users can freely navigate substantial distances, this becomes challenging, as the virtual movement cannot be matched in the real world for space constraints. It has been suggested that performing rotations in the physical world, while keeping translational movements purely virtual, may present a good compromise. However, most such control strategies use head orientation as input to determine the virtual movement direction and/or require additional tracking hardware. Using the head to control the virtual locomotion is problematic when the objective of the VR investigation relates to attention or gaze. For such research topics, it is critical to avoid confounding gaze and head orientation with commands for moving in the VR. Here, we propose a control strategy that combines virtual translation with physical body rotation to control VR locomotion. This leaves the head free from navigational control and allows studying attention, gaze and other cognitive processes in naturalistic settings and large, complex virtual environments. Importantly, we achieve this by standard software and hardware, which is part of typical consumer-grade VR bundles. |
21,312 | Please write an abstract with title: Cooperative Search Algorithm for UAVs Based on Multi-ant Colony, and key words: Simulation, Sociology, Object detection, Search problems, Autonomous aerial vehicles, Cost function, Probability distribution. Abstract: The cooperative search problem of multiple unmanned aerial vehicles (UAVs) in unknown sea environment is studied. Considering the influence of detection distance on target detection probability, UAV steering and collision avoidance threat, a multi ant colony cooperative search algorithm based on prior information is proposed. Firstly, according to the prior information of target distribution, the probability distribution map of target based on searching region is established. Then, the pheromone concentration is initialized according to the target probability distribution, and the prior information is used to guide various ant colony searches. According to the target probability, the state transition rules are designed to maximize the target discovery probability. Finally, the pheromone concentration is updated according to the advantages and disadvantages of the search path solution, and the effectiveness of the search strategy is verified by simulation. |
21,313 | Please write an abstract with title: Hierarchical Construction of Sound Speed Profile based on Argo and Sea Surface Data, and key words: Temperature sensors, Sea surface, Temperature distribution, Surface reconstruction, Correlation, Salinity (geophysical), Sea level. Abstract: Sound speed profile is an important content of hydroacoustics research, real-time acquisition of large-scale, high-precision sound speed profile is of great significance to ocean surveys. This paper studies the Indian Ocean from 2 degrees to 24 degrees north latitude and 50 degrees to 77 degrees east longitude. The data of the Argo sound speed profile; the sea surface temperature SST (Sea Surface Temperature) data and the sea level anomaly SLA (Sea Level Anomaly) data from September 2013 to 2015 are selected. Through correlation analysis, it is found that the sea surface data is feasible to reconstruct the sound speed profile and has a high degree of correlation with the upper layer (mixed layer and thermocline); therefore, through the establishment of a layered model, the upper layer adopts the sEOF-r method. The first two-order coefficients and sea surface data are used to construct a local temperature profile regression database; the lower layer uses the Empirical Orthogonal Function (EOF) method to obtain the full-sea depth temperature profile. Combined with the stable temperature-salt relationship and the empirical formula of sound speed, the sound speed profile is calculated. The analysis shows that the overall root mean square error of the upper layer of the temperature profile constructed by layers is 1.6234, and the overall root mean square error of the lower layer is 0.5439. The overall reconstruction result is accurate and conforms to the characteristics of the water area. |
21,314 | Please write an abstract with title: A fast position recovery approach for GPS receivers in jamming environments and a recommendation for future GPS signal structure, and key words: Global Positioning System, Jamming, Satellite navigation systems, Position measurement, Delay effects, Signal processing, Least squares methods, Performance evaluation, Decoding, Data mining. Abstract: The GPS receiver operation in a jamming environment brings several challenging tasks. If the signal is lost for a certain period of time then a reacquisition delay can be undesirable for time critical applications. The delay is due to necessity to find the lost signal again and to determine the time stamp on this signal which is contained in the navigation message. While the signal can be found in sub-second intervals with state-of-the-art prediction and searching strategies the time-stamp reading from navigation message may take up to six seconds provided good signal conditions. This paper suggests an approach to get a position fix without this time stamp recovery. It is based on an iterated least squares method and uses an excessive number of satellites to perform positioning with partially available measurements. It has been suggested initially for indoor positioning but is equally valuable for jamming environments. The method is simulated with GPS LI C/A signals which provided an evidence of its potential |
21,315 | Please write an abstract with title: Comparative Analysis of Next Generation Aircraft Data Networks, and key words: Protocols, Atmospheric modeling, Quality of service, Ethernet, Bandwidth, Aerospace electronics, Jitter. Abstract: Aircraft have many sensors and modules scattered throughout their fuselage. Due to the ever-increasing sensor load (radar, electronic warfare, radio, camera, etc.), aircraft need more bandwidth and higher broadband communication backbones. Legacy protocols such as ARINC-429 and MIL-STD-1553 used in the communication of these modules are insufficient to meet the increased bandwidth requirements of today’s aircraft. However, these legacy networks are highly reliable and deterministic, as avionics systems require. For this reason, different technologies have been developed without losing their quality of service and suitability for critical systems. Avionics Full-Duplex Switched Ethernet (AFDX) protocol, a special application of ARINC-664 Part 7, patented by Airbus, has come to the fore in recent years. Another prominent solution is the Time-Triggered Ethernet (TTEthernet) protocol, patented by TTTech. This paper compares these two protocols from the avionics perspective with a simulation model in OMNET++ and outlooks the new generation avionics networks. |
21,316 | Please write an abstract with title: Putting alternative sources of energy into prospective, and key words: Petroleum, Natural gas, Power generation, Energy consumption, Power engineering and energy, Transportation, Power generation economics, Solar energy, Fuels, Energy conservation. Abstract: The present United States energy consumption pattern is discussed and a realistic evaluation of the various energy options for the next ten to thirty years is presented. In this period oil and natural gas will essentially be exhausted and the emphasis will most likely shift to coal, nuclear energy, solar energy and synthetic fuels. Other alternative energy sources should also be developed since they may offer excellent solutions to specific regions. Energy conservation is essential and must be continuously implemented in all sectors of the economy. |
21,317 | Please write an abstract with title: Linking Inmates to Mental Health Services by Matching Records Between Independent Data Sets, and key words: Measurement, Couplings, Data security, Collaboration, Organizations, Mental health, Systems engineering and theory. Abstract: Officials in the United States correctional system have long been aware of the significant role that serious mental illness (SMI) plays in recidivism. In a 2011 study, Bronson reported that 68% of prison inmates with diagnosed SMI returned to custody at least once within 4 years, 8% higher than those without SMI [1]. This issue is especially prevalent in regional jails, where 63% of male inmates and 75% of female inmates in regional jails suffer from symptoms of serious mental illness every year, making immediate assistance to these individuals crucial [2]. In response, a team of University of Virginia (UVA) Systems Engineering students work in collaboration with an array of organizations in the Charlottesville-Albemarle region to identify and provide local jail inmates with the mental health services they need, and produce policy recommendations to improve conditions for individuals with SMI who are prone to exposure to the criminal justice system [3]. The current Capstone team consists of undergraduate UVA students who perform analysis using the data provided by the organizations, enabling the community to make informed decisions. However, these decisions are hindered because, since the data sets from different organizations are not linked with a unique identifier for individuals across the agencies that are responsible for the care and supervision of individuals suffering from SMI. This makes the matching of individuals between data sets difficult. This issue is exacerbated by recidivism, which results in multiple occurrences of similar (or identical) values, complicating typical record matching methods, which often rely on one-to-one matching methods. Moreover, the data include protected personal identifiers (PPI) and HIPPA protected data, which also restricts data sharing among the agencies. Thus, any effort to merge the data must adhere to applicable data security rules and non-disclosure agreements. To resolve these matching issues, we first condensed the reiterations of data within each dataset into one line per individual and included an internal consistency metric that reflects possible changes (i.e. preferred name, address, etc.) that could affect data matching. Then, we developed a matching algorithm using the Record Linkage package on Python that compares two data sets consisting of resident information from Region Ten Community Services (R10) and the Jail Management System (JMS) at the Albemarle-Charlottesville Regional Jail (ACRJ) [4]. As a result of this process, we identified over 95 additional matches and another 50 uncertain matches that required human spot-checking, which is an improvement of 10% to previous methods of record matching applied to the data set. Such results could have significant results to the Capstone team as well as to other fields of research, especially regarding medical, financial, or other forms of data that deal with changing data over time. |
21,318 | Please write an abstract with title: Spatiotemporal Characterization of Time-varying Optical Vortices with a Bulk Interferometer, and key words: Optical interferometry, Optical vortices, Crystals, Lasers and electrooptics, Laser stability, Spatiotemporal phenomena, Electrooptical waveguides. Abstract: We implement an in-line and ultrastable spatiotemporal technique based on uniaxial crystals, which solves high-complexity and stability problems associated with other techniques. Moreover, we generate and characterize the temporally resolved wavefronts of time-varying optical vortices. |
21,319 | Please write an abstract with title: MDS analysis of electrically large dual-reflector "PACO" antenna in 2-D, and key words: Reflector antennas, Electromagnetic scattering, Computational modeling, Integral equations, Feeds, Mathematics, Electronic mail, Numerical analysis, Mathematical model, Polarization. Abstract: In this work, Method of Discrete Singularities (MDS) is applied for a full numerical analysis of two-dimensional (2-D) model of dual-reflector PACO (parabolic subreflector and conical reflector) antenna, for the both polarization cases. Numerical results are shown, to illustrate the performance of the considered antenna. |
21,320 | Please write an abstract with title: Phenomenological Layer Structure of an Intelligent Agent for IoT, and key words: Biological neural networks, Calculus, Neuroscience, Computer architecture, Sensors, Training. Abstract: The main components in the study of multi-agent systems in the field of IoT are intelligent agents and contexts. From the viewpoint of each agent, the primary objective is to choose actions that maximize the agent's future utility. The choice of a correct action depends on a process of complex data collection from context. Using a neuroscience model, we consider the receptive field to slice the context area and to group the appropriate sensors. To permit the phenomenological analysis and consequent cognitive evaluation, we have applied Bellmund and Doeller's model of hippocampus identifying two types of cells: the map cells and the grid cells. The first linked to the positional aspects and the second to cognitive aspects. This paper describes only the phenomenological layer architecture. From a scientific point of view there is a novel fusion between fluent calculus and neural network ensemble. Such net is used to associate to situations' fluent the appropriate schema of actions. |
21,321 | Please write an abstract with title: A low latency router supporting adaptivity for on-chip interconnects, and key words: Delay, Network-on-a-chip, Routing, System-on-a-chip, Energy consumption, Power system interconnection, Chip scale packaging, Permission, Telecommunication traffic, Switches. Abstract: The increased deployment of system-on-chip designs has drawn attention to the limitations of on-chip interconnects. As a potential solution to these limitations, networks-on-chip (NoC) have been proposed. The NoC routing algorithm significantly influences the performance and energy consumption of the chip. We propose a router architecture which utilizes adaptive routing while maintaining low latency. The two-stage pipelined architecture uses look ahead routing, speculative allocation, and optimal output path selection concurrently. The routing algorithm benefits from congestion-aware flow control, making better routing decisions. We simulate and evaluate the proposed architecture in terms of network latency and energy consumption. Our results indicate that the architecture is effective in balancing the performance and energy of NoC designs. |
21,322 | Please write an abstract with title: Wireless Electronic Skin with Integrated Pressure and Optical Proximity Sensing, and key words: Wireless communication, Wireless sensor networks, Robot sensing systems, Skin, Optical sensors, Optical reflection, Robots. Abstract: Electronic skins and tactile sensors can provide the sense of touch to robotic manipulators. These sensing modalities complement existing long range optical sensors and can provide detailed information before and after contact. However, integration with existing systems can be challenging due to size constraints, the interface geometry, and restrictions of external wiring used to interface with the sensor. Here, we introduce a low-profile, wireless electronic skin for direct integration with existing robotic manipulators. The flexible electronic skin combines pressure, optical proximity sensing, and a micro-LIDAR device in a small, low profile package. Each of the sensors are characterized individually and the system is demonstrated on Robonaut 2, an anthropomorphic robot designed to work in environments designed for humans. We demonstrate the sensor can be used for contact sensing, mapping of local unknown environments, and to provide medical monitoring during an emergency in a remote area. |
21,323 | Please write an abstract with title: High-Order Taylor Expansion for Wind Field Retrieval Based on Ground-Based Scanning Lidar, and key words: Mathematical models, Laser radar, Taylor series, Atmospheric modeling, Wind speed, Volume measurement, Velocity measurement. Abstract: The uniform and linear wind models have been commonly used for wind field retrieval in meteorological community. However, the accuracy and robustness of the retrieval results can be quite unsatisfactory due to the mismatch between these models and the real wind distribution, especially under complex wind conditions. In this article, a nonlinear model based on high-order Taylor expansion is proposed to deal with this limitation, and the combination of ridge regression and decomposition-iteration process (denoted as Ridge-DI method) is further introduced to solve the model with high accuracy and robustness. A case study on simulation and field experiment shows that the proposed method with the third-order Taylor expansion can reduce the mean root-mean-square errors (RMSEs) of the retrieved velocities by more than 16.84% in comparison with traditional methods. |
21,324 | Please write an abstract with title: On the throughput performance of CSMA-based wireless local area network with directional antennas and capture effect: a cross-layer analytical approach, and key words: Throughput, Wireless LAN, Directional antennas, Performance analysis, Media Access Protocol, Physical layer, Access protocols, Multiaccess communication, Collision avoidance, Analytical models. Abstract: In this paper we develop a cross-layer analytical approach from both the physical layer and the medium access control (MAC) layer to evaluate the performance of the IEEE 802.11 wireless local area network (WLAN). From the physical layer, this analytical approach incorporates the effects of both capture and directional antenna, while from the MAC layer, our model takes account of the carrier sense multiple access with collision avoidance (CSMA/CA) protocol. Through a cross-layer modeling technique, this analytical framework can provide valuable insights of the physical layer impact on the throughput performance of the CSMA/CA MAC protocol. These insights can be helpful in developing a MAC protocol to fully take advantage of directional antennas for enhancing the performance of the WLAN. |
21,325 | Please write an abstract with title: Impact of Time-Step of Digital Controllers on the Harmonic Spectrum of Power Converters, and key words: Total harmonic distortion, Multilevel converters, Switching frequency, Power system harmonics, Harmonic analysis, Power electronics, Voltage control. Abstract: Modern digital controllers offer a variety of computational power (clock frequency/time-step), resolution and price choices. Their cost often varies based on the lowest time-step they offer. Since the controller’s time-step affects the accuracy of the generated modulated signal, it affects the generation of output signal harmonics in power converter applications. In this paper, the impact of the controller’s time-step is investigated with regard to the generated total harmonic distortion (THD) in the output signal. Moreover, the sinusoidal pulse modulation technique SPWM is compared with a novel wavelet-based modulation WPWM technique. Unlike SPWM, it does not rely on a high-frequency carrier which makes it less dependent on the controller’s time-step. A qualitative comparison is provided in this work based on the types of harmonics and THD generated in the output signal. |
21,326 | Please write an abstract with title: Extended orthogonal polyphase codes for multicarrier CDMA system, and key words: Multiaccess communication, Autocorrelation, Downlink, Wideband, Mobile communication, Bandwidth, Error correction, Error correction codes. Abstract: The Complete Complementary (CC) codes have been able to improve the performance of multicarrier CDMA system for both downlink and uplink transmission. However, the number of users supported by CC code design is limited as its family size is relatively small. In this letter, an extension to CC codes using Zadoff-Chu sequence is proposed. The proposed codes are able to support large number of users and have perfect auto- and cross-correlation function just like CC codes. |
21,327 | Please write an abstract with title: Editorial Special Section on Invited Papers in 2021 on Emerging Topics in the Power and Energy Society, and key words: Special issues and sections, Power grids, Microgrids, Power distribution networks, Power systems planning. Abstract: The publication of the 2020 Special Section of Invited Papers on Emerging Topics in the Power and Energy Society (PES) received broad interest from diverse readers of the PES community. We continued to publish the special section for another year. After a rigorous peer-review process, a total of 13 papers [A1]–[A13] were accepted for publication in this invited section of the IEEE Open Access Journal of Power and Energy (OAJPE) in 2021. |
21,328 | Please write an abstract with title: Modeling and Simulation of Si IGBTs, and key words: Insulated gate bipolar transistors, Solid modeling, Semiconductor device measurement, Scattering, Predictive models, Silicon, Semiconductor process modeling. Abstract: Technology CAD (TCAD) has been recognized as a powerful design tool for Si insulated gate bipolar transistors (IGBTs). Here, physical models, such as a mobility model for carrier-carrier scattering, were investigated for a predictive TCAD. Simulated currentvoltage characteristics of the trench-gate IGBTs were compared with measurements. The difference between 3D- and 2D-TCAD simulations was observed in a high current region, which was explained by a bias-dependent current flow. A test element group (TEG) for separation of the emitter currents for holes and electrons was also determined as effective for calibration of lifetime model parameters. |
21,329 | Please write an abstract with title: Use of wire-grid method to evaluate the effect of finite metallic plane of OATS on NSA in LF (30-100 MHz) region, and key words: Open area test sites, Wire, Attenuation, Receiving antennas, Transmitting antennas, Dipole antennas, Testing, Area measurement, Antennas and propagation, Electromagnetic interference. Abstract: A wire grid model is proposed to discuss the normalized site attenuation (NSA) associated with an open area test site (OATS) with finite metallic ground plane. The NSA values for three different OATS sites around Taiwan, based on the wire grid model and measurement, are carefully examined. The agreement between the calculated and measured results supports the usefulness of the proposed wire grid model. The wire grid model is then adopted to analyze the deviation in NSA values for the LF (30-100 MHz) region. |
21,330 | Please write an abstract with title: Progressive Semantic-Aware Style Transformation for Blind Face Restoration, and key words: Computer vision, Face recognition, Semantics, Robustness, Data models, Image restoration, Faces. Abstract: Face restoration is important in face image processing, and has been widely studied in recent years. However, previous works often fail to generate plausible high quality (HQ) results for real-world low quality (LQ) face images. In this paper, we propose a new progressive semantic-aware style transformation framework, named PSFR-GAN, for face restoration. Specifically, instead of using an encoder-decoder framework as previous methods, we formulate the restoration of LQ face images as a multi-scale progressive restoration procedure through semantic-aware style transformation. Given a pair of LQ face image and its corresponding parsing map, we first generate a multi-scale pyramid of the inputs, and then progressively modulate different scale features from coarse-to-fine in a semantic-aware style transfer way. Compared with previous networks, the proposed PSFR-GAN makes full use of the semantic (parsing maps) and pixel (LQ images) space information from different scales of input pairs. In addition, we further introduce a semantic aware style loss which calculates the feature style loss for each semantic region individually to improve the details of face textures. Finally, we pretrain a face parsing network which can generate decent parsing maps from real-world LQ face images. Experiment results show that our model trained with synthetic data can not only produce more realistic high-resolution results for synthetic LQ inputs but also generalize better to natural LQ face images compared with state-of-the-art methods. |
21,331 | Please write an abstract with title: Multi-Level Structure-Enhanced Network for 3D Single Object Tracking in Sparse Point Clouds, and key words: Three-dimensional displays, Target tracking, Point cloud compression, Object tracking, Representation learning, Search problems, Location awareness. Abstract: 3D single object tracking is the task of localizing a target object in a search point cloud frame. In this letter, we present a multi-level structure-enhanced tracking model to improve the tracking performance in sparse 3D point clouds. Towards this end, we first encode the target and the search point clouds efficiently in two near-neighbors graphs, which allows structural information to flow between neighbors along graph edges. We then design a cross-graph attention mechanism, which associates similar nodes across the target graph and the search graph, and further dissimilar graph nodes for apart. Integrating the proposed mechanism into the above Siamese feature learning of both the target and the search frame, we strengthen the structural correlation between the target and the search frame. In that case, distinguishing the potential target from the background in the search frame would be much simpler. Finally, we design a U-shaped sparse convolutional block to aggregate the structural features of the potential target in the search frame. Integrating the proposed block into an existing target localization module from (Hui et al., 2021), we localize target centers accurately. Experiments on the KITTI benchmark demonstrate that our method outperforms some state-of-the-art models, achieving at least a 3.2% improvement in terms of average tracking precision. |
21,332 | Please write an abstract with title: Anatomy and Performance of SSL Processing, and key words: Anatomy, Cryptography, Costs, Algorithm design and analysis, Performance analysis, Banking, Sockets, Cryptographic protocols, Privacy, Authentication. Abstract: A wide spectrum of e-commerce (B2B/B2C), banking, financial trading and other business applications require the exchange of data to be highly secure. The Secure Sockets Layer (SSL) protocol provides the essential ingredients of secure communications - privacy, integrity and authentication. Though it is well-understood that security always comes at the cost of performance, these costs depend on the cryptographic algorithms. In this paper, we present a detailed description of the anatomy of a secure session. We analyze the time spent on the various cryptographic operations (symmetric, asymmetric and hashing) during the session negotiation and data transfer. We then analyze the most frequently used cryptographic algorithms (RSA, AES, DES, 3DES, RC4, MD5 and SHA-1). We determine the key components of these algorithms (setting up key schedules, encryption rounds, substitutions, permutations, etc) and determine where most of the time is spent. We also provide an architectural analysis of these algorithms, show the frequently executed instructions and discuss the ISA/hardware support that may be beneficial to improving SSL performance. We believe that the performance data presented in this paper is useful to performance analysts and processor architects to help accelerate SSL performance in future processors |
21,333 | Please write an abstract with title: Word recognition by means of orthogonal functions, and key words: Speech recognition, Vocabulary, Loudspeakers, Automatic speech recognition, Software libraries, Adaptive algorithm, Automata, Automatic control, Control systems, Computer languages. Abstract: This paper describes experiments in which word recognition is based on comparing the projections of input words on an orthogonal basis with those of a stored library of words. An initial orthogonal basis is determined from the generalized spectrum of short time segments selected from a vocabulary of ten words. The initial basis is optimized by minimizing the complementary error energy. By projecting a spoken word onto the optimum orthogonal basis, a sequence of numbers is generated to represent the word. By correlating the absolute values of the sequence with those of a stored library of words, the spoken word is identified. The percent of correct recognition varies from 71.6 to 96.6 percent for two speakers. Techniques are developed to improve the recognition scores and to reduce the lengthy computer processing time and large storage requirement. First a master template is made for each word by averaging six templates for the particular word. For one speaker the percent of correct recognition increases to 100 percent when incoming words are compared against the master templates. For a second speaker, the recognition rates improve significantly and vary between 93 and 98 percent when the master templates are used. To further improve the recognition process, the feasibility of grouping words into several classes is demonstrated. The classifications are based on the locations of formant regions and the time durations of each spoken word. |
21,334 | Please write an abstract with title: A Centralized CB-MPC to Suppress Low-Frequency ZSCC in Modular Parallel Converters, and key words: Inverters, Centralized control, Voltage measurement, Active filters, Master-slave, Communication channels, Inductors. Abstract: The parallel operation of three-phase converters has become an effective way to achieve modularity. However, zero-sequence circulating current (ZSCC) will appear when the multiparalleled converter modules share a common dc link. In the event that the converters have different output powers and inevitable circuit parameter mismatch, low-frequency (LF) ZSCC can be produced. To address the LF-ZSCC issues, in this article, we propose a centralized carrier-based model predictive control (CB-MPC) scheme for modular parallel converters. This control scheme can be implemented either in master converters or in a dedicate central controller. The CB-MPC can achieve both power control and LF-ZSCC elimination. In addition, with carriers adopted, interleaving and fixed device switching frequency can be easily realized. As such, the benefits of model predictive control and interleaving can be combined. Based on the ZSCC model derived in this article, the elimination of LF-ZSCC can be achieved for more than two paralleled converters when they have different output powers and/or with parameter mismatch. The effectiveness of the proposed CB-MPC has been verified by the simulation and experimental results. |
21,335 | Please write an abstract with title: Co-clustering Vertices and Hyperedges via Spectral Hypergraph Partitioning, and key words: Text mining, Analytical models, Laplace equations, Signal processing algorithms, Clustering algorithms, Europe, Signal processing. Abstract: We propose a novel method to co-cluster the vertices and hyperedges of hypergraphs with edge-dependent vertex weights (EDVWs). In this hypergraph model, the contribution of every vertex to each of its incident hyperedges is represented through an edge-dependent weight, conferring the model higher expressivity than the classical hypergraph. In our method, we leverage random walks with EDVWs to construct a hypergraph Laplacian and use its spectral properties to embed vertices and hyperedges in a common space. We then cluster these embeddings to obtain our proposed co-clustering method, of particular relevance in applications requiring the simultaneous clustering of data entities and features. Numerical experiments using real-world data demonstrate the effectiveness of our proposed approach in comparison with state-of-the-art alternatives. |
21,336 | Please write an abstract with title: Sentiment Analysis Using Deep Learning: A Comparative Study, and key words: Deep learning, Computer science, Sentiment analysis, Companies, Tag clouds, Motion pictures, Data models. Abstract: Sentiment Analysis is a technique associated with Natural Language Processing in understanding the sentiments of the people. In today’s environment where shopping, watching movies, expressing thoughts or emotions is done via social platforms. The social platforms have become a stage where people can express their sentiments freely. Such behaviour has made it important for companies to provide the best of the platforms for their customers while using their services based on the polarity of their sentiments. In other cases where the manner of the sentiments is to be understood for security reasons or regarding any social issues, sentiment analysis has been the most important tool. In this work we have studied NLP, different deep learning techniques such as LSTM, BiLSTM and CNN along with Word Embeddings and their types: Glove and Word2Vec and performed a comparative study. We found improvement in BiLSTM and LSTM models using Glove(50d) word embeddings. [1]The accuracy received using LSTM and BiLSTM are: 90.36% using batch size 100 and 91.68% using batch size 128. We also tested the best model which was BiLSTM with batch size of 128 on an unlabelled testing data and also projected the results of it. The results were very impressive and promising and at the end the word clouds were created for all the reviews, positive and negative reviews respectively in the unlabelled dataset. |
21,337 | Please write an abstract with title: A Review : Fault Detection in Pipeline using Vibration analysis and Wireless Sensor Network Technologies, and key words: Vibrations, Location awareness, Wireless sensor networks, Fluids, Fault detection, Pipelines, Maintenance engineering. Abstract: In order to deliver fluid from one place to another the pipeline system is a commonly used method although as a result of low-quality maintenance and lack of efficient safety, there is an increase in loss financially which is usually associated with fluid waste and environmental hazards. This paper analyses different approaches to detect fault in pipeline structure, a brief overview of different techniques used to determine if a leak is present in a pipeline, although a series of experiment and testing need to be done in order to get more accurate result. |
21,338 | Please write an abstract with title: Side information aware coding strategy in the quadratic Gaussian CEO problem, and key words: Distortion measurement, Gaussian noise, Encoding, Decoding, Equations. Abstract: Summary form only given. The side information aware coding strategy was employed to address the quadratic Gaussian chief executive officer (CEO) problem. By using this strategy, the CEO problem is decomposed into a sequence of data fusion encoding and decoding blocks. We obtain the optimal rate allocation scheme that achieves the minimum distortion under a sum-rate constraint. We also derive the optimal sum-rate distortion tradeoff based on the successive coding strategy and show that our result is indeed the sum-rate distortion function for the quadratic Gaussian CEO problem. Hence, the optimal sum-rate distortion performance for the CEO problem is achievable using the successive coding strategy which is essentially a less complex way to attain a prescribed distortion |
21,339 | Please write an abstract with title: Multi-level Hierarchical Clustering Algorithm For Energy-theft Detection in Smart Grid Networks, and key words: Wireless sensor networks, Smart grids, Clustering algorithms, Routing, Robustness. Abstract: Without a good and a robust infrastructure, it is difficult for electricity providers to satisfy the increased demand needs, and to have an effective management of the electricity grid, from generation, transmission, and distribution. Several studies have shown that the Smart Grid represents a necessary evolution of current electrical infrastructures. By using communication technology like the Wireless Sensor Networks (WSNs), it is possible to effectively improve the reliability and robustness of electrical networks for better control, monitoring, and management visibility. The only concern is that existing grids often present infrastructure constraints in the implementation of these solutions. Moreover, the very exorbitant cost should not be overlooked, depending on the choice of technology. In agreement with the Chadian electricity company (SNE), this work presents a self-stabilizing hierarchical algorithm taking into account the electrical network. The proposed architecture considers two levels: the Home Area Networks (HAN) layer and Neighborhood Area Networks (NAN) layer. In essence, we define three types of nodes: Cluster Head (CH), Simple Node (SN) and Home Node (HN). Extensive simulations using the OMNeT++ simulator reveal that the proposed method can efficiently identify the fraudulent users in the system. |
21,340 | Please write an abstract with title: Typical application and economic evaluation under the background of deep integration of 5G+ smart grid, and key words: Economics, Technological innovation, Power demand, 5G mobile communication, Ultra reliable low latency communication, Communications technology, Smart grids. Abstract: In the era of energy Internet, with the deepening construction of strong smart grid, the emerging 5th generation mobile networks 5G communication technology will meet great market demand with its advantages of high bandwidth, low delay and low power consumption. It has become the key technology to lead and support the technological innovation of power system and realize the interconnection of all things. In view of the deep integration of 5G communication technology and smart grid in the future, it is necessary to study the characteristics of the power system itself and its requirements for communication to determine the key role that 5G communication technology can play in some specific fields. At first, this paper simply introduces the basic technology of 5G communication principle and the key performance indicators, in-depth study based on 5G core slice of the smart grid communication application scenarios, and finally combined with 5G and the advantages and significance of the smart grid integration, build a cost-benefit model of 5G+smart grid, to 5G+economy and rationality of the smart grid construction. |
21,341 | Please write an abstract with title: BuildingFusion: Semantic-Aware Structural Building-Scale 3D Reconstruction, and key words: Image reconstruction, Three-dimensional displays, Semantics, Liquid crystal displays, Collaboration, Two dimensional displays, Geometry. Abstract: Scalable geometry reconstruction and understanding is an important yet unsolved task. Current methods often suffer from false loop closures when there are similar-looking rooms in the scene, and often lack online scene understanding. We propose BuildingFusion, a semantic-aware structural building-scale reconstruction system, which not only allows building-scale dense reconstruction collaboratively, but also provides semantic and structural information on-the-fly. Technically, the robustness to similar places is enabled by a novel semantic-aware room-level loop closure detection(LCD) method. The insight lies in that even though local views may look similar in different rooms, the objects inside and their locations are usually different, implying that the semantic information forms a unique and compact representation for place recognition. To achieve that, a 3D convolutional network is used to learn instance-level embeddings for similarity measurement and candidate selection, followed by a graph matching module for geometry verification. On the system side, we adopt a centralized architecture to enable collaborative scanning. Each agent reconstructs a part of the scene, and the combination is activated when the overlaps are found using room-level LCD, which is performed on the server. Extensive comparisons demonstrate the superiority of the semantic-aware room-level LCD over traditional image-based LCD. Live demo on the real-world building-scale scenes shows the feasibility of our method with robust, collaborative, and real-time performance. |
21,342 | Please write an abstract with title: Analysis of Approaches to Use Wireless Sensors Networks in Design of the Spinal Traction Therapy Systems, and key words: Wireless sensor networks, Diseases, Medical treatment, Sensor systems, Force. Abstract: Wireless sensors networks is new technology, that can solve the problem of data transmission from multiple sensors in modern medical equipment. Robotic hardware and software system for diagnosis and treatment of spine diseases using traction therapy was proposed. In this paper we will discuss using wireless sensors network in the traction therapy system, its advantages and disadvantages, and also the field of practical implementation for this technology. In general, traction therapy system allows to use customized traction algorithms, brings the treatment quality to a new level and makes patient's life better. |
21,343 | Please write an abstract with title: An information statistics approach to data stream and communication complexity, and key words: Statistics, Complexity theory, Protocols, Algorithm design and analysis, Frequency, Sun, Computational modeling, Approximation algorithms, Computer science, Context. Abstract: We present a new method for proving strong lower bounds in communication complexity. This method is based on the notion of the conditional information complexity of a function which is the minimum amount of information about the inputs that has to be revealed by a communication protocol for the function. While conditional information complexity is a lower bound on the communication complexity, we show that it also admits a direct sum theorem. Direct sum decomposition reduces our task to that of proving (conditional) information complexity lower bounds for simple problems (such as the AND of two bits). For the latter, we develop novel techniques based on Hellinger distance and its generalizations. |
21,344 | Please write an abstract with title: The Usage of Load Intensity Balance Approach For 5G MAC Protocol Chatacteristics Investigation, and key words: Adaptation models, Protocols, 5G mobile communication, Quality of service, Media Access Protocol, Mathematical models, Numerical models. Abstract: The fifth generation networks 5G NR are the networks of the closest future providing possibility to serve the traffic with very different quality of service requirements. That makes the study of such technologies to be very challenging. The most approaches of the 5G MAC study are based on simulation. But this paper is aimed to use the load intensity approach proposed by professor A. Markhasin for investigation the probability-time characteristics of 5G MAC-protocol. That method is a numerical and analytical way to formalize the defined task and derive 5G MAC layer key performance indicators. The characteristics of average packet delay and normalized data rate versus input load intensity are derived for different protocol parameters such a frame format and priority are derived and shown in that paper. The adaptation of that approach is done relatively the intermediate channel load intensity parameter for solving the load balancing equation and getting the probability-time characteristics. |
21,345 | Please write an abstract with title: Policy driven mobile agents for ubiquitous medical diagnosis assistant system, and key words: Mobile agents, Medical diagnosis, Medical diagnostic imaging, Web server, Network servers, Hospitals, Diabetes, Protocols, Personal digital assistants, Wireless communication. Abstract: Ubiquity has been a key element to modern medical diagnosis system to improve medical service's efficiency and convenience on both medical personals and patients sides. Mobile agents and SIP technology make this anticipation possible. This paper proposes an approach to a ubiquitous medical diagnosis assistant system based on SIP, mobile agents and policy driven technology. First we describe mobile agent and SIP technology, and how they can integrate together at diagnosis assistant system. Second, we present a conceptual model for this medical diagnosis assistant system. Finally, a typical application scenario on diabetes management is described. |
21,346 | Please write an abstract with title: Basic Parameters of Coiled Fishing Line Actuator, and key words: Damping, Actuators, Temperature, Temperature control, Reliability, Springs, Thermal stability. Abstract: Coiled fishing line actuator is created by twisting the straight nylon fishing line under a constant tensile preload. Actuator looks like extension spring and its function is controlled by temperature changes. This article presents a brief introduction to this type of actuator and its basic parameters. |
21,347 | Please write an abstract with title: Passivity based control of a magnetic levitation system with two electromagnets for a flexible beam, and key words: Control systems, Magnetic levitation, Electromagnets, Vibration control, Feedback, Force control, Magnetic forces, Velocity control, Stability, Lyapunov method. Abstract: This paper presents a passivity based control of a magnetic levitation system handling a flexible beam supported by two electromagnets. Elastic vibrations sometimes cause control failure so it is important to suppress the elastic vibrations in order to ensure stable control in case of levitating a flexible object. The system can be decomposed into two subsystems: an electrical subsystem and a mechanical subsystem. It is shown that the whole system can be regarded as a feedback connected system with these subsystems and a controller for each subsystem can be designed independently. Passivity for each subsystem is also shown and a controller for each subsystem is designed based on its passivity. A controller for the electrical subsystem generates the desired magnetic force that makes the flexible beam follows a desired trajectory. A controller for the mechanical subsystem consists of position and velocity feedback related to deflections of the flexible beam. The whole controller ensures stability of the system and suppression of the elastic vibrations by means of Lyapunov stability theory. To illustrate the validity of the controller a numerical simulation is carried out. |
21,348 | Please write an abstract with title: Identifying the formation mechanism of redback pulsars, and key words: (stars:) binaries (including multiple): close, (stars:) evolution, (stars:) pulsars: general. Abstract: We analyse the evolution of close binary systems containing a neutron star that lead to the formation of redback pulsars. Recently, there has been some debate on the origin of such systems and the formation mechanism of redbacks may still be considered as an open problem. We show that the operation of a strong evaporation mechanism, starting from the moment when the donor star becomes fully convective (or alternatively since the formation of the neutron star by accretion-induced collapse), produces systems with donor masses and orbital periods in the range corresponding to redbacks with donors appreciably smaller than their Roche lobes, i.e. they have low filling factors (lower than 0.75). Models of redback pulsars can be constructed assuming the occurrence of irradiation feedback. They have been shown to undergo cyclic mass transfer during the epoch at which they attain donor masses and orbital periods corresponding to redbacks, and stay in quasi-Roche lobe overflow conditions with high filling factors. We show that, if irradiation feedback occurs and radio ejection inhibits further accretion on to the neutron star after the first mass transfer cycle, the redback systems feature high filling factors. We suggest that the filling factor should be considered as a useful tool for discriminating among those redback formation mechanisms. We compare theoretical results with available observations and conclude that observations tend to favour models with high filling factors. |
21,349 | Please write an abstract with title: Random coordinate descent methods for non-separable composite optimization, and key words: Europe, Linear programming, Optimization. Abstract: In this paper we consider composite optimization problems having the objective function formed as a sum of two terms, one has Lipschitz continuous gradient and another is differentiable but non-separable. Under these settings we design two random coordinate descent methods, one takes into account the composite form of the objective function, while the other algorithm disregards the composite form of the objective function yielding a random coordinate gradient descent scheme with a novel stepsize rule. Our methods are able to tackle both convex and non-convex problems. For these algorithms we also show that they are descent methods in expectation. Preliminary numerical results confirm the efficiency of our two algorithms. |
21,350 | Please write an abstract with title: Ensemble Learning of Numerical Weather Prediction for Improved Wind Ramp Forecasting, and key words: Weight measurement, Power measurement, Wind speed, Wind power generation, Predictive models, Real-time systems, Data models. Abstract: Numerical weather predictions used for wind power forecasting might not be updated in a timely manner in practice, due to its high computational complexity and complicated postprocessing. Thus, the accuracy of wind power forecasts could be significantly compromised especially during wind ramp events. This paper presents an innovative method for improving regional wind power ramp forecasting through ensemble learning of numerical weather prediction models, by using real-time weather measurements as the supervisory data. The numerical weather prediction models are combined to minimize the discrepancy between the forecast values and the real-time measurements in the trend of wind ramps, and the weights of the linear combination are calculated through gradient boosting. The proposed method is non-intrusive and could be efficiently carried out online. The proposed method is evaluated on historical ERCOT wind power ramp events, and compared with existing ensemble aggregation method using simple averaging. The results reveal the effectiveness of the proposed method for improving wind power forecasting during wind ramp events. |
21,351 | Please write an abstract with title: Calculations of enhanced field electron emission at the triple junction, and key words: Electron emission, Geometry, Dielectric constant, Physics, Vacuum breakdown, Moon, Material properties, Current density, Space charge, Potential energy. Abstract: Numerical calculations of the field enhancement were carried out for a finite geometry of triple junction which consists of a half space of metal, a quarter space of dielectric and a quarter space of vacuum. The electric field F was analytically obtained as a function of geometry and dielectric constant. It was found that the enhancement factor is approximately 50 and 20 in the vacuum and the dielectric regions, respectively. It was also found that the metallic size and dielectric constant only determines the field intensity but not the enhancement of the field. Taking into account the space charge effect produced by strong field, the enhancement of field emission becomes larger. |
21,352 | Please write an abstract with title: Bi-Directional Clamping Based H5, HERIC and H6-Type Transformerless Inverter Topologies with Improved Modulation Technique, and key words: Topology, Inverters, Leakage currents, Reactive power, Switches, Pulse width modulation, Clamps. Abstract: Transformerless inverters (TLIs) are well commercialized for Photovoltaic applications due to its small in size, less cost and high power conversion efficiency. However, the major challenge is to develop an inverter with reactive power capability and minimum leakage current. Therefore, in this paper, an improved H5, Heric, and H6-type topologies with bi-directional clamping branch are proposed to maintain constant common-mode voltage (CMV) during the freewheeling period. Thus, high-frequency variations due to switch junction capacitances in CMV are diminished and it further reduces the leakage current. Besides, an improved pulse width modulation scheme (PWM) provides a bidirectional current path during zero state to enhance the output waveform quality of the grid-connected inverter at different power factor conditions. Finally, the proposed concept is examined through the simulation results using Matlab software. |
21,353 | Please write an abstract with title: A Grid based Approach for Handwritten Text Segmentation, and key words: Writing, Connectors, Pattern analysis, Image segmentation, Computational modeling, Analytical models, Shape. Abstract: The hand-written text is subject to inconsistency and variability. To achieve the accuracy and consistency in recognizing handwritten characters, the present work discusses an efficient approach to segment the handwritten text into individual characters. In order to achieve this, the writing space is divided into three different zones and then the zones are subdivided tiny square shape grids, which are distributed evenly. After this, we analyze to find the presence of handwritten character in a selected grid by performing horizontal scanning method. Moreover, we propose an approach of segmenting the character set of a single line text by vertical scanning and curve pattern analysis on the touching zones of the selective grids. The efficacy of the approach has proven through rigorous testing on hand-written texts of both professional as well as non-professional users. The testing set consists of 106 text samples including both single line text phrases and short sentences. The proposed approach achieves around 100% accuracy for word level text segmentation on the handwritten texts of both professional and non-professional users. In addition, the average character level segmentation accuracy on texts written by professional and non-professional users are found to be 98.4% and 96.2% respectively. Thus, the average character level segmentation accuracy is improved by 97.3%. |
21,354 | Please write an abstract with title: Assessment of approaches for technical diagnostic of pump faults with induction motor as transducer, and key words: Feature extraction, Hydraulic systems, Induction motors, Pumps, Error analysis, Data mining, Circuit faults. Abstract: The centrifugal pump is an important component in industry and its failure and repair are associated with high cost. These cost can be reduced by technical diagnostics. Besides the additional monitoring of the pump and the motor, there is the approach of using the motor as a sensor. In this case the current and voltage signals of the motor are used for the diagnosis of both components. The extension of the known approaches from motor diagnostics for pump faults is currently subject of the research. It is not known whether these approaches can be used to recognize the conditions healthy, cavitation, hydraulic blockage and dry running or which approach delivers the best classification result. In order to clarify this several experiments with a pump on a test bench are conducted. |
21,355 | Please write an abstract with title: Input selection in data-driven fuzzy modeling, and key words: Input variables, Fuzzy systems, Data mining, Hydrogen, Data engineering, Iterative methods, Fuzzy sets, Computational efficiency, Iterative algorithms, Testing. Abstract: An iterative backward selection method for determination of relevant input variables in data-driven fuzzy modeling is presented. The method utilizes parameters of the Takagi-Sugeno model as a factor to determine the significance of input variables. As a result, it is less computationally intensive than most of the existing methods for input variable selection. |
21,356 | Please write an abstract with title: Super Resolution of Medical Images Using Generative Adversarial Networks, and key words: Measurement, Digital control, Computational modeling, Magnetic resonance imaging, Superresolution, Neural networks, Medical services. Abstract: This paper aims to present a new model called SRMIGAN that performs super-resolution for MRI and CT medical images to help doctors reach a better diagnosis. This model, SRMIGAN adopts deep learning by applying generative adversarial networks technique. It is developed using MSE loss and by exploiting different optimization techniques. This model is compared to other adopted models by using both objective and subjective metrics. Hence PSNR, SSIM, and mean opinion score results are included. The results show that our model beats the other examined models. |
21,357 | Please write an abstract with title: Investigation of the properties of textile electrodes in order to apply them as capacitive electrodes, and key words: Electrodes, Clothing, Capacitive sensors, Standards, Chemicals, Textiles, Manufacturing systems. Abstract: The paper presents a study of the change in the parameters of textile electrodes depending on the service life and external, mechanical and chemical effects. The aim of the study is to prove their applicability as capacitive sensors for capturing biomedical signals, in terms of keeping their parameters within acceptable limits for repeated use and after long service life. |
21,358 | Please write an abstract with title: A fast method for real-time median filtering, and key words: Filtering algorithms, Hardware, Speech processing, Image processing, Smoothing methods, Councils, Signal processing algorithms, Acoustic signal processing. Abstract: A fast real-time algorithm is presented for median filtering of signals and images. The algorithm determines the kth bit of the median by inspecting the k most significant bits of the samples. The total number of full-word comparison steps is equal to the wordlength of the samples. Speed and hardware complexity of the algorithm is compared with two other fast methods for median filtering. |
21,359 | Please write an abstract with title: Optimization of SC-LDPC Codes for Window Decoding With Target Window Sizes, and key words: Codes, Decoding, Measurement, Optimization methods, Windows, Couplings, Complexity theory. Abstract: In this paper, we propose an optimization method for protograph-based spatially coupled low-density parity-check (SC-LDPC) codes under window decoding (WD). Previous works on constructing SC-LDPC codes for WD typically focused on optimizing asymptotic performance metrics such as the WD threshold. However, in this paper, it is observed that the WD threshold is not an appropriate metric to sufficiently explain the finite-length behavior of SC-LDPC codes under WD. Thus, we propose a new performance metric, called the window mean parameter, based on a scaling analysis to capture the WD performance more accurately and formulate a code optimization algorithm that optimizes the proposed performance metric. Since the proposed metric depends on the window size, the optimization algorithm can provide a code family of SC-LDPC codes optimized for various target window sizes. Simulation results confirm that the improvement in the proposed metric leads to a finite-length performance improvement, resulting in one to two orders of the frame error rate gain over the conventional SC-LDPC codes for a wide range of window sizes. Furthermore, we investigate structural characteristics of the proposed codes to provide a supplementary explanation for the performance improvement, which also promotes a better understanding of SC-LDPC codes for WD. |
21,360 | Please write an abstract with title: Website Recommendation with Side Information Aided Variational Autoencoder, and key words: Measurement, Computational modeling, Neural networks, Predictive models, Motion pictures, Linear programming, Recommender systems. Abstract: Recommender systems had been proposed to help people to find the interested items, such as recommending products to a buyer; identifying movies or music that a user will find interest, etc. However, the existing recommendation approaches mainly focus on capturing user-item interaction patterns for prediction, and ignore the user's side information such as visit frequency and duration. In this paper, we study the side information aided website recommendation problem that using the browsing history of a set of users and their side information to predict the websites that will be of interest to a certain user. We propose a novel recommendation approach called SI-VAE that incorporates side information with the variational autoencoders (VAEs) model for top-k recommendation. The proposed method takes both user-website interaction information and side information as input, and adopts an encoder/decoder model to generate user's interested websites from partial observations. The model of SI-VAE is implemented as a neural network, and trained with a multinomial likelihood objective function to form the ranking of user-website interaction probabilities. We conduct extensive experiments on two real-world datasets, which show that the proposed model outperforms the baselines in a number of performance metrics in website recommendation. |
21,361 | Please write an abstract with title: Analysis of Demand-side Business Opportunities in Iran, as a Digital Transformation Perspective, and key words: Digital Transformation, Electricity Grid, Demand-Side, Business Opportunities, Commercial Product. Abstract: The digital transformation of electrical utilities has gained an ongoing attention in recent years; It means a tremendous change using disruptive technologies (including Internet of Things (IoT), Data Analytics, Artificial Intelligence, etc.) which leads to new data-driven business opportunities. On the other hand, various projects have been conducted in this field by the Joint Research Center (JRC) in the European Union (EU), mostly focused on the demand-side, and several commercial product and services have been developed. Iran is also moving through the way of transforming its grid digitally, which would lead to the appearance of several business opportunities. In this paper, after detailed review and classification of the commercial products developed or used in EU projects, the business opportunities of Iran electricity grid digital transformation, with emphasis on demand-side management, has been discussed. |
21,362 | Please write an abstract with title: LIMAN: Local Information-Based Multiattention Network for 3D Shape Recognition, and key words: Solid modeling, Three-dimensional displays, Feature extraction, Solid modeling, Correlation, Visualization, Training data. Abstract: Exploring effective 3D shape recognition algorithms attracts much research attention recently. The existing multiview-based 3D shape recognition methods usually ignore the local information exploration in each view image. In this article, we propose a novel local information-based multiattention network, which concentrates the effective information in the feature maps and captures the view-wise interactions to improve the shape representation performance. Concretely, we design the spatial-aware and channel-aware weight learning modules to quantify the contributions of each spatial region and channel for feature map updating in the view-wise descriptor extraction process. Then, the multihead attention module is introduced for multiview feature aggregation, considering the view-wise interactions to preserve the effective information. Finally, we generate the discriminative shape descriptors for 3D shape recognition task. We conduct comprehensive experiments on the ModelNet databases and achieve competitive performances compared with the state-of-the-art methods. |
21,363 | Please write an abstract with title: On Coding Theorems for General Simultaneous Channels, and key words: Codes, Automatic control, Automation, Signal design, Filters, Mean square error methods, Linear systems, Probability distribution, Circuit theory. Abstract: This paper deals with the lengths of codes for several simultaneous channels in a general formulation. The paper is almost self-contained, and requires for its reading no prior knowledge of information theory. |
21,364 | Please write an abstract with title: Authentication and integrity in telecommunication signaling network, and key words: Authentication, Telecommunication switching, Communication system signaling, Telephony, Switching circuits, Databases, Switches, Convergence, Wireless networks, Cryptographic protocols. Abstract: The signaling system 7 (SS7) is a signaling system for the public switched telephone network (PSTN). SS7 network transports call setup, teardown messages, database queries, trunk status, instructions for remote phone switches and so on, in fact it acts as a glue for the circuit switched network. Telecommunication deregulation, liberalization of economies and convergence of telephone, IP and wireless networks has broken the trust enjoyed so long by PSTN as being considered a closed community network. The convergence results in increasing number of interfaces between SS7 and other networks, and each brings with it many vulnerabilities. This paper first analyzes existing security threats due to virtually non-existent authentication and integrity check process and then presents a MTPSec solution at the MTP3 layer in the SS7 protocol stack which provides security services through cryptographic operations. It can be implemented at each signaling point (SP) throughout the network to provide link-by-link security or at least at the SPs residing at the interface between two networks or trust sets. |
21,365 | Please write an abstract with title: A Review and Analysis of Attack Vectors on MIL-STD-1553 Communication Bus, and key words: Military standards, Security, Synchronization, Codes, Standards, Military vehicles, Aerospace electronics. Abstract: MIL-STD-1553 has been used for the past four decades by the military as a standardized, reliable, and fault-tolerant communication bus to provide connectivity between different embedded components in mission-critical military vehicles. The bus was designed with a great focus on reliability, responsiveness, and fault tolerance. However, its security aspects were an afterthought. Indeed, in the early 1970s, the notion of cyberattacks was not ubiquitous as it is today. Attacking computerized systems located at very high altitudes was an inconceivable scenario for many people, including security engineers. With current developments in cybersecurity and telecommunication networks, the security analysis of the MIL-STD-1553 bus reveals that the system is not immune from cyberattacks. The bus is vulnerable to many attacks that could seriously damage the entire system. Rebuilding the security of MIL-STD-1553 from scratch is cost prohibitive and a very complex, not scalable, and inflexible approach. A common alternative to embedding security to the existing system is the development of an intrusion detection system that can be added to the MIL-STD-1553 bus with minimal cost. In this article, we review and discuss some possible attack vectors on the MIL-STD-1553 bus. Then, we analyze the risk and consequences of each attack vector on a fighter jet. This review and analysis will provide security engineers with a holistic overview of possible attacks and their related risk on MIL-STD-1553 to better design an effective intrusion detection system. |
21,366 | Please write an abstract with title: Computer-Simulated Design of an Active Microwave Allpass Network, and key words: Computer networks, Active filters, Microwave transistors, Microwave filters, Gallium arsenide, Microwave integrated circuits, Computer simulation, Passive filters, Microwave frequencies, FETs. Abstract: A new microwave active allpass network is proposed. In a computer simulation, it is shown that the network, even with markedly non-ideal transistors, can provide a true allpass response over 8 - 12 GHz. |
21,367 | Please write an abstract with title: Battle Humanoid, and key words: Engines, Robots, Wires, Radio frequency, Voltage control, Microcontrollers, Capacitors. Abstract: This inventive system is made for errands which incorporate high peril for individuals to enter, especially for some criminal case and may exhibit amazingly beneficial for military zone for spying purposes. This system makes uses robotized vehicle which urges not solely to enter a locale incorporating high risk yet moreover it is furnished with laser gun to destroy the foes when required. The system moreover fuses remote camera transmitter which is prepared for spouting the video got by the robot remotely to the remote DVR which can be related with common TV for audit. The whole system is constrained by methods for signal in a remote spot and consequently by improvement of the hand towards forward, left and right movement robot advancement can be controlled. The transmitter system sends headings to the getting circuit mounted on the robotized vehicle through RF Transmitter set in the remote end. The tolerant circuit incorporates ARDUINO and a RF beneficiary which gets headings sent remotely to control the advancement of the mechanical module and to control the shooting movement of the laser weapon. |
21,368 | Please write an abstract with title: Data Augmentation for Insider Threat Detection with GAN, and key words: Conferences, Training data, Tools, Generative adversarial networks, Generators, Data models, Detection algorithms. Abstract: In insider threat detection domain, the datasets are highly imbalanced, where the number of user's normal behavior is higher than that of insider's anomalous behavior. A direct approach to handle the class imbalance problem is using data augmentation on the minority class. Existing data augmentation methods mainly produce synthetic samples according with the linear operation based on samples of the minority class. Hence, these methods just focus on local information which leads to the unitarily of the synthetic samples, resulting in overfitting. To enrich the diversity of the synthetic samples, we propose a deep adversarial insider threat detection (DAITD) framework using the Generative Adversarial Networks (GAN) to approximate the true anomalous behavior distribution. Specifically, we first obtain anomalous user behavior representations from the anomalous behavior data (minority class), and then use the generator of the GAN to model the actual anomalous behavior distribution, use the discriminator of the GAN to distinguish whether the synthetic sample from the generator is real or not. In this way, our method is able to generate high quality synthetic samples that are close to the anomalous user behavior. Experimental results show that the DAITD framework outperforms other comparative inside threat detection algorithms. |
21,369 | Please write an abstract with title: An Improved Harmony Search Based on Teaching-Learning Strategy for Unconstrained Binary Quadratic Programming, and key words: Benchmark testing, Search problems, Quadratic programming, Optimization. Abstract: Unconstrained binary quadratic programming (UBQP) problem plays an important role in operational research due to its application potential and its computational challenge. This paper presents a new hybrid algorithm based on Harmony Search (HS) and Teaching-Learning-Based Optimization. The main features of the proposed algorithm called harmony search with teaching-learning (HSTL) are the integration of teaching-learning strategy in the basic harmony search. This hybridization has led to an efficient hybrid framework which achieves better balance between the exploration of HS and the exploitation capabilities of the Teaching-Learning-Based Optimization. Experiments on numerous benchmark problems having 50 to 2500 variables show the effectiveness of the proposed framework and its ability to achieve good quality solutions. |
21,370 | Please write an abstract with title: RIA Post Accelerator Design, and key words: Particle beams, Ion accelerators, Voltage, Acceleration, Frequency, Linear particle accelerator, Isobaric, Particle separators, Ion beams, Temperature. Abstract: Overall design of the post accelerator for the RIA project is described with emphasis on performance for different ion beams. Characteristics for beams from A=10 to A=240 are provided with an estimate of output intensities. The selection rational for different accelerating structures, both for the normal conducting and for the superconducting types, is provided for a system design that accelerates beams to at least 10 MeV/u for heavy ions and up to 20 MeV/u for light ions. |
21,371 | Please write an abstract with title: Disturbance Observer based Controller Design to Reduce Sensor Count in Standalone PVDG Systems, and key words: Batteries, Load modeling, Voltage control, Mathematical model, Stability analysis, Disturbance observers, Power system stability. Abstract: Standalone photovoltaic distributed generation (PVDG) systems have found their way into many popular off-grid applications like deserts, military and rural development. Generation of power at the consumption site and supplying power in DC make these systems more efficient due to minimization of losses during transmission and conversion. But, these systems suffer from lower inertia and this factor added with uncertainties in power generation and load consumption, greatly affects system stability. Nonlinear control techniques like backstepping although effective, are expensive to implement since they are model-based and demand information from many sophisticated sensors. In this paper, a disturbance observer based on back-stepping control strategy is proposed for grid voltage control and MPPT of an isolated PVDG system with storage consisting of PV array, battery and load. The effects of irradiation and temperature on PV arrays, the variations in loads and battery voltage are modeled in the form of disturbances. Instead of measuring these entities with sensors, the update laws designed in this paper based on Lyapunov stability theory estimate their values which are further utilized for effective control during intermittencies. It can be seen from the MATLAB simulation results that adoption of this technique contributes towards faster and cheaper control of the PVDG system for a greater range of operating conditions. |
21,372 | Please write an abstract with title: From Ensemble Clustering to Subspace Clustering: Cluster Structure Encoding, and key words: Encoding, Codes, Clustering algorithms, Predictive coding, Optimization, Training, Sparse matrices. Abstract: In this study, we propose a novel algorithm to encode the cluster structure by incorporating ensemble clustering (EC) into subspace clustering (SC). First, the low-rank representation (LRR) is learned from a higher order data relationship induced by ensemble K-means coding, which exploits the cluster structure in a co-association matrix of basic partitions (i.e., clustering results). Second, to provide a fast predictive coding mechanism, an encoding function parameterized by neural networks is introduced to predict the LRR derived from partitions. These two steps are jointly proceeded to seamlessly integrate partition information and original features and thus deliver better representations than the ones obtained from each single source. Moreover, an alternating optimization framework is developed to learn the LRR, train the encoding function, and fine-tune the higher order relationship. Extensive experiments on eight benchmark datasets validate the effectiveness of the proposed algorithm on several clustering tasks compared with state-of-the-art EC and SC methods. |
21,373 | Please write an abstract with title: Multivideo compression in texture space, and key words: Cameras, Video compression, Image coding, Streaming media, Layout, Video recording, Sampling methods, Humans, Decoding, Bandwidth. Abstract: We present a model-based approach to encode multiple synchronized video streams depicting a dynamic scene from different viewpoints. With approximate 3D scene geometry available, we compensate for motion as well as disparity by transforming all video images to object textures prior to compression. A two-level hierarchical coding strategy is employed to efficiently exploit inter-texture coherence as well as to ensure quick random access during decoding. Experimental validation shows that attainable compression ratios range up to 50:1 without subsampling. The proposed coding scheme is intended for use in conjunction with free-viewpoint video and 3D-TV applications. |
21,374 | Please write an abstract with title: Online Weight Pruning Via Adaptive Sparsity Loss, and key words: Training, Deep learning, Adaptive systems, Image coding, Conferences, Neural networks, Network architecture. Abstract: Pruning neural networks has regained interest in recent years as a means to compress state-of-the-art deep neural networks and enable their deployment on resource-constrained devices. In this paper, we propose a robust sparsity controlling framework that efficiently prunes network parameters during training with minimal computational overhead. We incorporate fast mechanisms to prune individual layers and build upon these to automatically prune the entire network under a user-defined budget constraint. Key to our end-to-end network pruning approach is the formulation of an intuitive and easy-to-implement adaptive sparsity loss used to explicitly control sparsity during training, enabling efficient budget-aware optimization. |
21,375 | Please write an abstract with title: Security Vulnerabilities Detected in Medical Devices, and key words: Medical diagnostic imaging, Medical services, Industries, Monitoring, Computer security. Abstract: The increasingly close connection between medical devices and computer networks has given rise to novel cybersecurity threats. Due to the elevated number of connected medical devices, this means that more opportunities for security vulnerabilities exist. To safeguard against cybersecurity breaches in medical devices, understanding the complex nature of the operational surroundings is essential, and knowing about each technical susceptibility is valuable. The purpose of this paper is to discuss a network model of medical devices. Security vulnerabilities in the devices, as well as potential methods of attack, were examined. A solution is provided to improve the security of IT systems, due to essential role medical devices play in patient outcomes. |
21,376 | Please write an abstract with title: Optimal point-wise control of distributed parameter systems based on wavelet transform, and key words: Optimal control, Distributed control, Control systems, Distributed parameter systems, Wavelet transforms, Function approximation, Matrix converters, Automation, Educational institutions, Machinery. Abstract: Point-wise control is a typical control strategy for distributed parameter systems control. Since the employment of /spl delta/-function in point-wise control, it becomes very difficult to design the control law. The orthogonal function approximation is applied to deal with the optimal point-wise control of distributed parameter systems, and Haar wavelets have been chosen as orthogonal functions in this paper. The differential operational matrix and the product integrated operational matrix of Haar wavelet base have been proposed. The various operational matrices have been applied to convert the optimal point-wise control of distributed parameter systems to the lumped one, and an approximation algorithm has been obtained. The illustrated simulation results have validated the efficiency of the presented algorithm. |
21,377 | Please write an abstract with title: Measurement and analysis of building entry loss in High base station environment, and key words: Antenna measurements, Propagation, Buildings, Urban areas, Vegetation mapping, Propagation losses, Mobile communication. Abstract: High-Altitude Platform Station (HAPS), which provides communication services from an altitude of 20 km via an Unmanned Aerial Vehicle (UAV), is attracting much attention as a new mobile communications platform for ultra-wide coverage areas and disaster-resilient networks. A HAPS can provide mobile communications services directly to smartphones. In order to design efficient cell configurations for HAPS-based services, we need a radio wave propagation model that takes into consideration factors such as terrain, vegetation, urban areas, suburban areas, and building entry loss. We measure and clarify the building entry loss characteristics at various elevation and azimuth angles environment. In this paper, based on measured results, we identified the key parameters required for the site-specific building entry loss model and proposed a site-specific model. |
21,378 | Please write an abstract with title: Identification of Voltage Sag Sources Based on Wavelet Transform Sample Entropy and Extreme Learning Machine, and key words: Wavelet transforms, Analytical models, Extreme learning machines, Power quality, Feature extraction, Entropy, Indexes. Abstract: Accurate identification of voltage sag sources is the basis for the allocation of responsibilities and governance decisions for voltage sags. In order to solve the problem of voltage sag sources identification, this paper proposes a voltage sag sources identification method based on the combination of wavelet transform sample entropy and extreme learning machine. First, wavelet transform is used to decompose the voltage signal, and the sample entropy is extracted from its approximate coefficients and detail coefficients to form a feature vector; then based on the extreme learning machine theory, a voltage sag sources identification model is established, and the feature vector is input into the identification model to identify the type of voltage sag source. Through simulation analysis, the performance of the proposed method is evaluated by the confusion matrix and its evaluation index, which proves the correctness and feasibility of the proposed method. |
21,379 | Please write an abstract with title: Research on Text-based Q&A System Technology for Medical Aesthetic Field, and key words: Training, Information science, Dictionaries, Shape, Computational modeling, Diversity reception, Search problems. Abstract: Medical aesthetics is the process of re-homing the shape of various parts of the body using medical means in order to meet the subjective definition of beauty. A text-based question and answer system in the field of medical aesthetics can provide quick answers to patients’ various medical search needs and help them to consult online and get professional explanations of their medical aesthetic problems. We propose the GPT2 Medchat model as an important part of the system and need to set up the following aspects to complete the system: 1. We prepare a new dataset in the medical aesthetics domain, which covers a wide range of questions and answers with strong professionalism. 2. In the pre-training phase, high-quality dialogue texts in the medical aesthetics domain are used as training materials. The system is built based on the pre-training phase. The medical text is used as training material, and the GPT2 Medchat model is trained and fine-tuned by relying on the pkuseg professional medical model to segment the medical text. The optimized segmentation results are used as a medical dictionary. 3. Sampling strategy to ensure the quality and diversity of the quizzes under the specified medical aesthetic domain questions. Both objective and subjective evaluations show that the GPT2 Medchat model has achieved a high practical and reference value for quizzing in the medical aesthetics domain. |
21,380 | Please write an abstract with title: KingFisher: Unveiling Insecurely Used Credentials in IoT-to-Mobile Communications, and key words: Performance evaluation, Privacy, Authentication, Mobile applications, Internet of Things, Servers, Data communication. Abstract: Today users can access and/or control their IoT devices using mobile apps. Such interactions often rely on IoT-to-Mobile communication that supports direct data exchanges between IoT devices and smartphones. To guarantee mutual authentication and encrypted data transmission in IoT-to-Mobile communications while keeping lightweight implementation, IoT devices and smartphones often share credentials in advance with the help of a cloud server. Since these credentials impact communication security, in this paper we seek to understand how such sensitive materials are implemented. We design a set of analysis techniques and implement them in KingFisher, an analysis framework. KingFisher identifies shared credentials, tracks their uses, and examines violations against nine security properties that the implementation of credentials should satisfy. With an evaluation of eight real-world IoT solutions with more than 35 million deployed devices, KingFisher revealed that all these solutions involve insecurely used credentials, and are subject to privacy leakage or device hijacking. |
21,381 | Please write an abstract with title: Analysis of infrared polarization signatures for backgrounds and objects, and key words: Atmospheric modeling, Landmine detection, Optical sensors, Soil, Optical polarization, Infrared spectra, Atmosphere, Object detection, Optical materials, Environmental factors. Abstract: Recent investigations into the use of new electro-optical sensing modalities for the detection of landmines and other objects in complex backgrounds have led to the need to understand the optical properties of background materials (e.g., soils) in more detail. In particular, the use of polarimetric signatures in the optical and infrared domains has been the subject of much study; an understanding of soil optical properties and their variations is critical to evaluating the utility of these signatures. Our research examined polarimetric signatures and corresponding metrics in the context of a real world environment; specifically, we examined the spectral polarization characteristics of landmines and soils within a complex radiative environment. Our initial results indicate that the optical properties of sand dominate the resultant signature for the buried and flush-buried cases. Therefore, a spectral phenomenological model for the polarization signature of the combined sand-landmine system was developed for the infrared band (mid-wave and long-wave infrared) to study these issues in more detail; this model included the effects of various environmental factors such as solar insolation and atmosphere. The modeling paradigm centered on a radiative transfer approach coupled with heat transfer results to account for incident and emitted radiation simultaneously; the Hapke emission model served as a basis for the current investigations. This paper presents a description of the physics-based model for the spectral polarization signatures of buried, flush, and surface land mines and soil features along with signature effects arising from changes in the atmosphere and other environmental processes. |
21,382 | Please write an abstract with title: A new GPC-based PID controller using memory-based identification, and key words: Three-term control, Control systems, Tuning, Automatic control, System identification, Industrial control, Chemical processes, Equations, Automatic generation control, Parameter estimation. Abstract: In this paper, a system identification scheme is proposed based on a memory-based modeling (MBM) method. According to the MBM method, some local models are automatically generated based on input/output data pairs of the controlled object stored in the data-base. Therefore, even if the system includes nonlinearities, the parameter estimation can work well. Furthermore, a PID parameters tuning method is discussed based on the relationship between the generalized predictive control (GPC) and the PID control. Then, the estimates given by the proposed identification scheme are utilized for the GPC-based PID controller. |
21,383 | Please write an abstract with title: Extraction and Analysis of Micro-Doppler Signature in FMCW Radar, and key words: Frequency modulation, Conferences, Mathematical analysis, Radar, Robustness, Radar signal processing, High frequency. Abstract: Micro-Doppler effect due to target micro-motions induce additional frequency components in the received radar signal. In addition to other target parameters, these micro-Doppler signatures can be used for target identification. For targets with high frequency micro-motion we observe that the conventional extraction of micro-Doppler signature in Frequency Modulated Continuous Wave (FMCW) radar fails due to insufficient sampling frequency along the slow-time. In this paper, we first develop a signal model for FMCW radar in the presence of a target with micro-motions. It can be inferred from the model that the micro-Doppler signature is preserved in the received signal. We then propose an approach to extract high frequency micro-Doppler signatures for FMCW radar, and verify it using simulation studies and experimental results. |
21,384 | Please write an abstract with title: Blocking probability and channel assignment in wireless networks, and key words: Intelligent networks, Wireless networks, Spread spectrum communication, Telecommunication traffic, Traffic control, Network topology, Interference, Quality of service, Steady-state, Routing. Abstract: We consider a multi-hop wireless network with a connection-oriented traffic model and multiple transmission channels that can be spatially re-used. In such a network the blocking probability of a call that makes a channel request depends on (a) the channel assignment scheme and (b) the transmission radius of the nodes which affects the network link structure. In this work, we study these two aspects for simple wireless networks. Specifically, we develop blocking probability analysis for a wireless line and grid network and explore the tradeoff between transmission radius and blocking probability for multi-hop calls. We show that for a line network a larger transmission radius can substantially reduce the blocking probability of calls, while for a grid network with a more dense node topology using a smaller transmission radius is better. We then, investigate various channel assignment schemes and present a novel non-rearranging channel assignment algorithm for multi-hop calls in a general network. Our algorithm efficiently incorporates spatial channel re-use and significantly reduces call blocking probability when compared to other algorithms. |
21,385 | Please write an abstract with title: Ultra low-loss waveguides of 0.12 dB/cm directly written in pure silica glass by femtosecond laser pulses, and key words: Silicon compounds, Glass, Waveguide lasers, Optical pulses, Optical waveguides, Ultrafast optics, Pulse amplifiers, Optical refraction, Optical variables control, Optical pumping. Abstract: Ultra low-loss of 0.12 dB/cm at 1580 nm was achieved for directly written waveguides in pure silica glass using femto-second laser for the first time as far as we know. A three-dimensionally structured optical splitter was also demonstrated. |
21,386 | Please write an abstract with title: Adaptive Contactor – A New Scheme to Improve Induction Motor Immunity to Voltage Sags, and key words: Rotors, Torque, Induction motors, Power quality, Load modeling, Equivalent circuits, Electromagnetics. Abstract: One of the consequences of voltage sags is unexpected motor trips or stalls. This is caused by the simple voltage-magnitude-based tripping logic used in the motor contactors. Since a motor has momentum during a voltage sag, a deep voltage sag with a short duration does not necessarily lead to motor misoperation. Based on this reasoning, a novel motor contactor operation scheme is proposed in this paper. The proposed scheme takes into account both the magnitude and duration of a voltage sag plus the momentum of the rotor, in real-time, to decide if a motor will be tripped. The core idea of the scheme is to utilize the critical clearance time (CCT) of motors as the tripping time of AC contactors. The proposed scheme combines an offline analysis and an online calculation to minimize the computation burden in real-time operation. An improved motor parameter estimation method is also proposed to ensure the accuracy of the calculated CCT. The performance of the proposed scheme is evaluated and demonstrated through comparative case studies. Moreover, some practical issues are discussed to facilitate the real implementation. |
21,387 | Please write an abstract with title: Creative destruction [car crash testing], and key words: Vehicle crash testing, Automotive engineering, Vehicle safety, Engineering profession, System testing, Road accidents, Computer crashes, Steel, Research and development, Technological innovation. Abstract: Crashing cars-lots of them-is how Volvo safety engineer Daniel Hedqvist earns his living. Running cars into steel barriers or other cars or the sides of mountains is his job. These days the Swede rigging up plenty of Fords for crash tests. Ford owns the prestigious Volvo, Jaguar, and Aston Martin car companies, and has made Sweden its center of excellence for vehicle safety testing. There's a good reason why the second-largest US car maker has ceded this area of expertise to a non-US supplier: few auto companies have won as many awards for car safety as Volvo. This article discusses safety testing of cars at Volvo using virtual crashes and real crashes. The unique features of the test facilities are briefly outlined including the two intersecting test tracks: a 154-meter fixed track and an 80-meter movable one that can be turned as much as 90 degrees. Front and side collisions can thus be tested at virtually all angles. If the back door at the end of the movable track is opened, cars can be sent flying directly into the rocky hillside outside. For so-called barrier tests, a single car on the fixed track hurtles into an 850-ton block at the far end. |
21,388 | Please write an abstract with title: Metalorganic vapor-phase epitaxy of antimonide for application to 1.55 /spl mu/m VCSELs on InP substrates, and key words: Epitaxial growth, Vertical cavity surface emitting lasers, Indium phosphide, Substrates, Distributed Bragg reflectors, Reflectivity, Mirrors, Molecular beam epitaxial growth, Epitaxial layers, Refractive index. Abstract: A distributed Bragg reflector at 1.55 mum grown monolithically by metalorganic vapor-phase epitaxy is reported. The DBR composed of 24 AlGaAsSb/InP periods achieves a reflectivity of 99.5% over the 2 inch wafer surface |
21,389 | Please write an abstract with title: Near-Optimal Consensus of Multi-Dimensional Double-Integrator Multi-Agent Systems, and key words: Consensus protocol, Performance analysis, Cost function, Taylor series, Multi-agent systems, Laplace equations, Topology. Abstract: In this paper, a distributed near-optimal method is presented for the consensus of multi-agent systems with multiple multi-dimensional double integrators. The method is developed based on the performance index regarding the consensus behavior with respect to the agent state differences and the control efforts of the agents. By using the Taylor expansion method, an analytical distributed near-optimal controller is presented for solving the optimal consensus problem. A simulative example is presented to demonstrate the performance of the method. |
21,390 | Please write an abstract with title: A novel fingertip haptic device for display of local contact geometry, and key words: Haptic interfaces, Displays, Geometry, Fingers, Shape, Motion control, Prototypes, Testing, Virtual environment, Control system synthesis. Abstract: This paper presents a new concept of fingertip haptic device for the display of local contact geometry on the user's fingerpad. We propose an extension of the encountered haptic interface concept (Y. Sato et al., 2004), in order to build an active haptic thimble, that is portable and can be fixed to the user's finger. The device is endowed with an actuation system that controls the motion of a platform, that can come in contact with the fingerpad with different orientations and at different fingerpad locations, simulating the contact with a virtual surface. A prototype of the device has been built and tested and is presented throughout the paper. |
21,391 | Please write an abstract with title: Three learning systems in the reconnaissance of basic movements in contemporary dance, and key words: Learning systems, Reconnaissance, Hidden Markov models, Humans, Stochastic processes, Principal component analysis, Vector quantization, Space technology, Databases, Data mining. Abstract: Although action and gesture recognition by human beings, for example dance movements, is a high level process executed in the human brain there is quite a bit of structure imposed on the task so that it be can be analyzed by a computer by dividing it into a chain of more simple steps. One technique that has been successfully used in developing automatic systems to identify this type of activities, is the hidden Markov models (HMM). In this work, an automatic recognition system of basic movements in the contemporary dance that uses three learning techniques is presented. The first two of these techniques are used in order to generate the discrete observations needed in the Markov model associated to each of these movements. In the first one, the principal components analysis is used to extract the most relevant information coming from sensors tied to dancers who execute the movements. In the second one, the vector quantization is used in order to convert the output of the first data pretreatment to discrete symbols and so to feed the HMM to identify a given movement or for adjusting model parameters so as to best account for the observations. |
21,392 | Please write an abstract with title: Design of quadratic filters based on the D norm for seismic deconvolution, and key words: Deconvolution, Nonlinear filters, Wiener filter, Filtering, Reflectivity, Entropy, Reflection, Kalman filters, Shape, Nonlinear equations. Abstract: In this paper, quadratic filters are designed for seismic deconvolution. These nonlinear filters can be easily obtained from optimizing the D norm for the Minimum Entropy Deconvolution (MED) algorithm. Due to the symmetric structure of the quadratic filter, the actual number of filter coefficients is reduced. In finding the filter coefficients, a system of linear equations is obtained. Recently, efficient methods to realise these quadratic filters have been reported. Simulation results show that low order quadratic filters are usually sufficient and that the filtered output indicates the seismic events even when the seismic wavelet is nonminimum phase. When the data are contaminated with noise, quadratic filters can still perform reasonably well. In the case of a complex reflectivity series, nonlinear filtering is superior to linear filtering. Examples of processing synthetic seismic data by linear and nonlinear filtering are presented. |
21,393 | Please write an abstract with title: Architecture for area-efficient 2-D transform in H.264/AVC, and key words: Automatic voltage control, CMOS technology, Video compression, Discrete transforms, Discrete cosine transforms, Algorithm design and analysis, Integrated circuit interconnections, Silicon, Very large scale integration, Application specific integrated circuits. Abstract: As the VLSI technology advances continuously, ASIC can easily achieve the required performance and most of them are actually over-designed. Thus, architecture shrinking is inevitable in optimal designs especially when supply voltages are getting lower. However, conventional designs starting from minimization of algorithmic operations (e.g. multiply) may not always lead to optimal architectures, for the wires and the interconnection complexity significantly grow and have become predominant. This paper explores algorithms and architectures for the 2-D transform in H.264/AVC, of which the operations are very simple (i.e. only shift and add). We have shown that fewer operations do not always result in more compact designs. In our experiments with the UMC 0.18 /spl mu/m CMOS technology, the most straightforward matrix multiplication without separable 2-D operation or any fast algorithm has the best area efficiency for DI-size (720/spl times/480) video at 30 fps. It saves 48%, 34%, and 16% silicon area of the previous works respectively. |
21,394 | Please write an abstract with title: Efficiently Vehicle Route Planning based on Metaheuristic Algorithm in 5G, and key words: 5G mobile communication, Navigation, Roads, Wireless networks, Simulation, Signal processing algorithms, Simulated annealing. Abstract: Navigation is an important function when we want to travel or reach a new place. Although the navigation can lead the people to go to the destination, the user always hopes that it can fast to achieve the site. However, the situation on the road is unpredictable, so that the vehicle routes need to adjust in real-time. Fortunately, the concept with mobile edge computing (MEC) and vehicle to anything (V2X) in the fifth-generation wireless network (5G), that can help us to achieve the goal. In this paper, we take the achieved destination time of vehicle, vehicle route, and retransmission times for network package into account for the multi-objective optimization (MOO) problem in 5G. Then, we through the Efficiently Vehicle Route Planning based on simulated annealing algorithm (EVRPSA) to find the best vehicle route. The simulation results show using our method can planning the vehicle route efficiently. |
21,395 | Please write an abstract with title: Polarization characteristics of a mixed seeding pasture and its application for predicting the ratio of legumes, and key words: Optical polarization, Reflectivity, Wavelength measurement, Remote monitoring, Radiometry, Optical sensors, Optical surface waves, Surface morphology, Satellite broadcasting, Q measurement. Abstract: Reflectance (R), polarized reflectance (Q) and degree of polarization (P) were measured for a mixed seeding pasture consisting of white clover and tall fescue in 8 spectral bands in the visible, near- and short-wave infrared wavelength ranges. Horizontal leaves in the white clover canopies generated more polarized light than vertical leaves of the tall fescue. Polarization (Q and P) increased as the ratio of legumes (ROL, leaf area ratio of white clover to the total) increased in the mixed sown canopies. A multiple regression model that used a Q and Rs of 3-bands that were all acquired at view zenith angle 60/spl deg/ explained 90% of the variation of ROL with RMSE 11%. The regression model was validated by a data set provided in the next growing season. The model including polarization information was comparatively more stable inter-annually than the model of reflectance only. It is effective to utilize the polarization information of reflected light as a method of estimating ROL of mixed seeding pastures where planophyll and erectophyll plant species coexist. Polarization is appropriate for ROL monitoring in pastures. |
21,396 | Please write an abstract with title: Identification Of Dominant Features in Non-Portable Executable Malicious File, and key words: Computer science, Codes, Feature extraction, Malware, Encryption, Anti-virus software. Abstract: Malware group identification is a crucial procedure that involves extracting unique properties from a collection of malware samples. Several malware developers now employ different tactics, such as encryption and obfuscation, to avoid the detection of their programmers’ distinctive properties. This research proposes features for extracting malware from file contents. it searches a sample dataset for non-portable executable files, then disassemble the file, and removes structural discrimination characteristics from non-Portable harmful files. dominant features combined with analysis techniques, and retrieved characteristics help to tell the difference between harmful and non-malicious files. The purpose of the research is to bring a noble collection of qualities to well-known malware characteristics. |
21,397 | Please write an abstract with title: 1 kW PFC converter with compound active-clamping, and key words: Diodes, Parasitic capacitance, Resonance, Clamps, Voltage, Stress, Switches, Inductors, Prototypes, Testing. Abstract: A PFC converter employing compound active clamping technique is proposed. It can effectively reduce the loss caused by diode reverse recovery. The parasitic oscillation caused by the parasitic capacitance of the boost diode is eliminated. The maximum voltage stress of switches and the soft-switching region with relation to the resonant inductor and resonant capacitance are investigated. A prototype of 1 kW is built to test the proposed topology. |
21,398 | Please write an abstract with title: Joint Wireless and Service Allocation for Mobile Computation Offloading with Job Completion Time and Cost Constraints, and key words: Energy consumption, Costs, Wireless networks, Programming, Mobile handsets, Delays, Resource management. Abstract: This paper proposes a method of joint wireless network and job service allocation for use with mobile computation offloading where task completion times have deadline constraints. In this design, mobile devices (MDs) may execute a computational task locally or offload the task through a wireless network for execution on an edge server (ES). The network owner offers to lease wireless communication channels at a given set of base stations along with edge server capacity that is used for job execution. The objective is to obtain a wireless and service capacity allocation that minimizes the total energy consumption of the mobile devices, subject to a cost budget constraint and constraints on the delay incurred by offloaded task execution. The design is first formulated as a mixed integer nonlinear programming problem. An approximate solution is then obtained by decomposing it into a collection of convex subproblems that can be efficiently solved. Results are presented that demonstrate that the proposed solution achieves near optimum performance over a wide range of system parameters. |
21,399 | Please write an abstract with title: Cooperative Interference Management for Over-the-Air Computation Networks, and key words: Power control, Interference, Sensors, Wireless communication, Task analysis, Performance evaluation, Noise reduction. Abstract: Recently, over-the-air computation (AirComp) has emerged as an efficient solution for access points (APs) to aggregate distributed data from many edge devices (e.g., sensors) by exploiting the waveform superposition property of multiple access (uplink) channels. While prior work focuses on the single-cell setting where inter-cell interference is absent, this article considers a multi-cell AirComp network limited by such interference and investigates the optimal policies for controlling devices' transmit power to minimize the mean squared errors (MSEs) in aggregated signals received at different APs. First, we consider the scenario of centralized multi-cell power control. To quantify the fundamental AirComp performance tradeoff among different cells, we characterize the Pareto boundary of the multi-cell MSE region by minimizing the sum MSE subject to a set of constraints on individual MSEs. Though the sum-MSE minimization problem is non-convex and its direct solution intractable, we show that this problem can be optimally solved via equivalently solving a sequence of convex second-order cone program (SOCP) feasibility problems together with a bisection search. This results in an efficient algorithm for computing the optimal centralized multi-cell power control, which optimally balances the interference-and-noise-induced errors and the signal misalignment errors unique for AirComp. Next, we consider the other scenario of distributed power control, e.g., when there lacks a centralized controller. In this scenario, we introduce a set of interference temperature (IT) constraints, each of which constrains the maximum total inter-cell interference power between a specific pair of cells. Accordingly, each AP only needs to individually control the power of its associated devices for single-cell MSE minimization, but subject to a set of IT constraints on their interference to neighboring cells. By optimizing the IT levels, the distributed power control is shown to provide an alternative method for characterizing the same multi-cell MSE Pareto boundary as the centralized counterpart. Building on this result, we further propose an efficient algorithm for different APs to cooperate in iteratively updating the IT levels to achieve a Pareto-optimal MSE tuple, by pairwise information exchange. Last, simulation results demonstrate that cooperative power control using the proposed algorithms can substantially reduce the sum MSE of AirComp networks compared with the conventional single-cell approaches. |
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