Search

This paper explains a design and the comparison of two multi-disc permanent magnet motor. The actuator must provide answers to the volume constraint and torque. This application is employed in land transport for aeronautical field. The axial flux motors become interesting when obtaining large surfaces of air-gap with the traditional machines is no possible. Indeed, surfaces of air-gap are more important in comparison with a radial flux machine, and, in a given volume, they allow to obtain a higher torque. After having shown the multi-air gap structure, we describe the design method from elementary cells. That's why two types the disc-type motor were selected. This paper clearly shows the efficient topology of a disc-type multi-air gap machine.

With increased demands, power modules are often required to run at higher temperatures with improved reliability. Solder joint fatigue is a major failure mode for current power modules. Silver sintering die-attach technology significantly improves power module reliability. Due to the reliability problem at the interface between aluminum (Al) wire and a silver (Ag) layer, bonding Ag wire to the Ag layer is highly desired. Ag wire is harder and stiffer than Al wire, resulting in much higher wear and significantly reduced lifetime of consumables. This paper introduced the K&S CuEx™ bond tool and studied coupling and interaction between the bond tool and Ag wire. By optimizing the bonding process, the CuEx™ bond tools achieved 400,000 touchdowns, which is 80× more than the standard bond tool lifetime of 5,000 touchdowns. The difference between the front-cut and rear-cut process is discussed. By studying and optimizing the cutting process, the standard rear-cut cutter blade lifetime is increased 4×, from 50,000 cuts to 200,000 cuts. It is observed that Ag wire did not wear a wire guide much faster than Al wire. The standard wire guide exhibited minimum wear after 200,000 bonds.

This paper presents a novel control strategy for an above-knee powered prosthetic leg that unifies the entire gait cycle, eliminating the need to switch between controllers during different periods of gait. Current control methods divide the gait cycle into several sequential periods each with independent controllers, resulting in many patient-specific control parameters and switching rules that must be tuned by clinicians. Having a single controller could reduce the number of control parameters to be tuned for each patient, thereby reducing the clinical time and effort involved in fitting a powered prosthesis for a lower-limb amputee. Using the Discrete Fourier Transformation, a single virtual constraint is derived that exactly characterizes the desired actuated joint motion over the entire gait cycle. Because the virtual constraint is defined as a periodic function of a monotonically increasing phase variable, no switching or resetting is necessary within or across gait cycles. The output function is zeroed using feedback linearization to produce a single, unified controller. The method is illustrated with simulations of a powered knee-ankle prosthesis in an amputee biped model and with examples of systematically generated output functions for different walking speeds.

The continuous Skyline query has recently become the subject of the several researches due to its wide spectrum of applications such as multi-criteria decision making, graph analysis network, wireless sensor network and data exploration. In these applications, the datasets are huge and have various dimensions. Moreover, they constantly change as time passes. Therefore, this query is considered as a computation intensive operation that finding the result in a reasonable time is a challenge. In this paper, we present an efficient parallel continuous Skyline approach. In our suggested method, the dataset points are sorted and pruned based on Manhattan distance. Moreover, we use several optimization methods to optimize memory usage in comparison with naive implementation. In addition, besides the applied conventional parallelization methods, we partition the time steps based on the number of available cores. The experimental results for a dataset that contains 800k points with 7 dimensions show considerable speedup.

Various control strategies are being used to achieve high performance operation of linear motor drives. To maintain minimum volume and weight of the power supply unit on board the transportation vehicle, peak thrust per unit current operation is a desirable objective. True peak thrust per unit current through slip control is difficult to achieve because the parameters of linear induction machines vary during normal operation. This paper first develops a peak thrust per unit current control law based on the per-phase equivalent circuit for linear induction machines. The algorithm for identification of the variable parameters in induction machines is then presented. Application to an operational linear induction machine (LIM) demonstrates the utility of this algorithm. The control strategy is then simulated, based on an operational transit LIM, to show the capability of achieving true peak thrust operation for linear induction machines.

Measurement and analysis experiences have shown great difficulties in interharmonic detection and measurement due to their small amplitudes and their consequent vulnerability from harmonics spectral leakage. The spectral leakage is due to lack of synchronization between the analyzed waveforms actual periods and the sampled window length, deriving from both fundamental frequency deviations and nonsynchronized interharmonics. This paper compares the techniques, that are introduced by the same authors in previous papers and that improve the IEC recommended signal processing: the utilization of the classical Hanning Window, in place of the Rectangular; the harmonic filtering and the self tuning signal processing. All the techniques are applied to numerical and experimental tests showing the different performances.

This paper evaluates the benefits of energy storage systems applied to renewable intermittent sources like wind. With this objective, a 144 MW Portuguese wind farm is used as a case-study. The storage system design and evaluation processes use a computational tool developed in MatLab to simulate the wind farm operation with an energy storage system and computes the remuneration tariff. The energy storage design settles on a system of 5 MW with 30 MWh. The simulation results show a 2.1% gain in wind farm tariff and a improved adjustment on generation to the typical electricity demand curve. Considering the storage system design and an available storage technology survey, one concludes that redox flow batteries are the best suited to application, in spite of their present prices being not the most advantage.

Delivering reliable service requires satisfactory operation of numerous line components, spanning significant geographical areas and subject to environmental, electrical, and mechanical stresses, plus normal aging. Conventional reliability practices use periodic maintenance to minimize failures, coupled with rapid restoration procedures when outages occur. Reliability statistics have shown little change in decades. Newer technologies can shorten outages, by automatically rerouting service to customers on healthy feeder segments, but they: require redundant paths for power flow; react only after outages occur; and often require communications with pole-mounted switches. Over the past decade, Texas A&M University has demonstrated that electrical waveforms, available via conventional substation-based CTs and PTs, contain evidence of failures, incipient failures, and improper operation of feeder equipment, often well before these conditions escalate and cause outages. This provides the basis for conditioned-based maintenance and outage avoidance. This paper provides examples, from operating feeders, demonstrating some of these advances.

In this paper, a new reference waveform estimation strategy based on an adaptive notch filter (ANF) is proposed for unified power quality conditioner (UPQC). Two coupled ANFs are used to generate the reference waveforms for shunt and series components of UPQC. Mathematical properties of proposed algorithm are presented in detail. The technique is simple and its speed and accuracy are controllable. Moreover, robustness against internal parameter variations is a feature of this method. Numerical simulations result show the superiority of the algorithm for compensation of voltage and current distortions in compare with the conventional methods.

In this paper, we consider the age of information (AoI) of a discrete time status updating system, focusing on finding the stationary AoI distribution assuming that the Ber/G/1/1 queue is used. Following the standard queueing theory, we show that by invoking a two-dimensional state vector which tracks the AoI and packet age in system simultaneously, the stationary AoI distribution can be derived by analyzing the steady state of the constituted two-dimensional stochastic process. We give the general formula of the AoI distribution and calculate the explicit expression when the service time is also geometrically distributed. The discrete and continuous AoI are compared, we depict the mean of discrete AoI and that of continuous time AoI for system with M/M/1/1 queue. Although the stationary AoI distribution of some continuous time single-server system has been determined before, in this paper, we shall prove that the standard queueing theory is still appliable to analyze the discrete AoI, which is even stronger than the proposed methods handling the continuous AoI., 9 pages, 3 figures, Accepted for presentation in ITW 2021

This paper addresses the Joint Angle and Delay estimation problem of a received multi-carrier frame through multiple antennas. In particular, each source is parameterized through its complex gain, Time-of-arrival (ToA) and Angle-of-arrival (AoA). We develop three novel JADE methods in a partially relaxed model, where one relaxes the interference zone, while focusing on a certain direction at a given time. Computer simulations are given with comparison to the Cramer-Rao Bound.

Network coding has been applied successfully in peer-to-peer systems to shorten the distribution time, particularly in extreme conditions where peers in the network are clustered and separated by physical links with limited bandwidth. In this paper, we focus more closely on the use of source coding, i.e. encoding is done only at the source, as an alternative to network coding to facilitate content distribution under such limited bandwidth configuration. We observe analytically and experimentally that, in this specific case, with appropriately chosen expansion factors, source coding can have comparable performance to network coding in terms of distribution time, yet consuming much less computational resources than the latter approach does.

In the paper a concept of creating a filtering network based on first order nonstationary elements is presented. In each element of the structure two outputs were used: low-pass and high-pass. Replacing gain coefficient k and time constant T with gain function and time function considerably improved the system operation in the time domain. During the research effects of the corresponding stationary, nonstationary and partially stationary structures were compared.

In this paper, a class of 1D fuzzy numbers is studied. The definitions of arithmetic operations such as addition, subtraction, scalar multiplication and multiplication between fuzzy number and fuzzy number are given without the aid of alpha-level set. And also we study the expectation, variance, covariance of fuzzy random variables and differential, Stieltjes integral of fuzzy number-valued functions without the aid of set-valued theory which is very different from the present research approach. Fuzzy number-valued Brownian motion and its properties are studied, which are very similar to real-valued Brownian motion.

This paper presents a compact up-conversion mixer using commercial 0.18-μm CMOS technology for UWB system applications. To achieve broadband frequency response, low power consumption, and small chip size simultaneously, the folded structure and inductor-free matching network are adopted. The measured mixer demonstrates a measured wideband response from 1 to 11 GHz with a conversion loss of lower than 6 dB. The dc power consumption is 25 mW under a supply voltage of 1.8-V, with a compact chip size of 0.5 mm times 0.6 mm.

In this paper, a new configuration for a multi-terminal offshore wind farms based VSC-HVDC and large scale photovoltaic system using modified unified adaptive linear neuron (Adaline) algorithm is presented. In the offshore station, the permanent magnet synchronous generator (PMSG)-based wind turbines are tied to the bus via back-to-back converters and a step-up transformer. The large scale photovoltaic power is connected to the dc bus between the offshore voltage source converters (VSC) and onshore VSC-HVDC stations via a modular multilevel converter (MMC). The Power management and the synchronization between two buses are achieved by controlling the two VSC converters. The performance of the topology proposed is tested using Matlab/Simulink during permanent operation mode and in the presence of DC fault.

In this paper, phase unwrapping techniques, which are the most critical step in extracting the Digital Topography Maps of the region in Interferometric Synthetic Aperture Radar imaging, are discussed and compared. Algorithms based on path following method for the phase unwrapping, which is the heart of the interferometric SAR (InSAR/IFSAR) technique were analyzed comparatively using real SAR images. Comparisons of the algorithms in terms of performance, duration, complexity have been made and evaluations on how to cover the missing aspects have been included. In addition, both Matlab and C / C ++ codes of the algorithms are analyzed due to time constraints that may occur while producing the topography map of large regions.

Sudoku is a very popular mathematical and logical curiosity with abundant variations. Many artificial intelligence (AI) programs that imitate human expertise have been developed to solve sudoku puzzles. However, most popular methods, such as Recurrent Relational Networks and Double Q-learning, are primarily reinforcement learning (RL) algorithms. These algorithms are rather complex since they consist of two or more fundamental models for achieving high accuracy. To circumvent this drawback, this paper proposes a simple Multi-Layer Perceptron (MLP) model that not only produces correct results but is easy enough for implementation as well. Since the MLP model is a supervised learning method and is widely used in classification problems, this paper first discusses how the training data is generated. It then demonstrates a coding method that can be used to convert 4 × 4 sudoku puzzles to classification problems. Afterward, it shows the MLP settings and how the predictions from the model can be transformed into legal solutions. This model has been thoroughly tested on sudoku puzzles with various levels of difficulty, and the resulting data illustrate that its accuracy is no worse than those reinforcement learning methods and other non-AI algorithms. Moreover, with slight modification, the MLP model can be utilized on larger scales, such as 9 × 9 sudoku puzzles, or even harder ones.

Wireless Power Transfer (WPT) is a new technology for charging the electric vehicles that can make free humans from annoying wires. In recent years, WPT systems have been developed and have significant advances. Design of an inductive power transfer (IPT) has several sections; the two important of which are design of the power electronic devices and design of the pad topology and electromagnetic issues. In this paper, we have discussed the second section and examined parameters that affect the magnetic coupling coefficient between the two pads especially for DD Pad structure.

In distribution system, the subject of fault location has been of considerable interest for a long time. The objective of this paper is to develop Cumulative approach for fault location based on statuses of Fault Indicators (FI), Circuit Breakers (CB), Fuses and Fault Impedances from distance protection devices. This approach is using mainly graph theory algorithms and Area Marking Strategy to resolve fault diagnosis problem in electric power networks. Unlike neighborhood approach where one link only affects the marking of neighbor areas, cumulative approach marks all areas down the link. In many situations, cumulative approach may outperform neighbor approach.

This paper discusses the performance of the first CrIS flight instrument and its data product performance. Together with ATMS, the CrIS sensor is a critical payload for National Polar-orbiting Operational Environmental Satellite System (NPOESS) and will first fly on the NPOESS Preparatory Project (NPP) mission, the risk reduction flight for NPOESS. NPOESS is the next generation weather and climate monitoring system for the U.S. Air Force and National Oceanic and Atmospheric Administration (NOAA), being developed under contract by Northrop Grumman Aerospace Systems. This paper describes instrument radiometric performance such as calibrated spectral response shape, error residuals and absolute spectral calibration of the CrIS Flight Model 1 (FM1) sensor including the signal processing algorithms used to radiometrically and spectrally calibrate the CrIS sensor. This includes a description of the CrIS ground algorithms that convert Raw Data Records (RDR) into calibrated Sensor Data Records (SDR) and then the SDRs into Environmental Data Records (EDR).

High speed transmission of information suffers inevitably by intersymbol interference (ISI) induced by multipath propagation over frequency selective channels. ISI has been a major obstacle preventing the successful implementation of physical layer network coding (PLNC) systems in these environments. Another major obstacle is the high computational complexity of existing algorithms dealing with ISI, which is a determining factor in the design of relay nodes. In this paper, we propose a novel and computationally efficient decision feedback equalizer structure that is utilized at the end node and in conjunction with a simple amplify and forward (AF) technique employed at the relay. We derive the optimal equations for the decision feedback equalizer (DFE) coefficients and evaluate the end-to-end bit error rate performance in frequency selective channels, and provide both analytical and numerical simulation results that demonstrate the feasibility of the proposed approach under realistic channel conditions. The obtained results show that E2E performance is dominated by the channel with most severe frequency selectivity.

In this paper, the output regulation of multi-agent systems over signed digraphs is discussed. We consider antagonistic interactions among subsystems and propose a distributed feedback paradigm to achieve the output regulation goal. The reference and disturbance signals are produced by exosystems, which can be considered as a leader. However, not all subsystems have access to the information of the leader for constructing a feedback law to achieve the output regulation objective. The paper presents a distributed feedback strategy that makes all subsystems track the reference signal in a bipartite manner while rejecting the inflicted disturbance. Finally, the theoretical findings of this paper are validated through a numerical example.

Non-motorized transport is becoming increasingly important in urban development of cities in China. How to evaluate the non-motorized transport popularity of urban roads is an interesting question to study. The great amount of tracking data generated by smart mobile devices give us opportunities to solve this problem. This study aims to provide a data driven method for evaluating the popularity (walkability and bikeability) of urban non-motorized transport system. This paper defines a p-index to evaluate the popular degree of road segments which is based on the cycling, running, and walking GPS track data from outdoor activities logging applications. According to the p-index definition, this paper evaluates the non-motorized transport popularity of urban area in Wuhan city within different temporal periods., 5 pages, 4 figures, CPGIS2018-The 26th International Conference on Geoinformatics

Insurance telematics is a disruptive technology that is expected to reform the vehicle insurance industry. Based on sensor data, the traditional measures for calculating the insurance premium are complemented to determine a fee that more accurately predicts the risk profile of the policyholder. From an instrumentation and measurement point of view, there are several insurance telematics challenges that have to be tackled. It is about consistently extracting relevant figures of merit (FoMs) like number of harsh braking, speeding, heavy cornering, trip smoothness, etc, and then to transform these FoMs into a valid measure, or score, that determines the risk profile of the insurance customer. The paper presents a characterization of FoMs in terms of actuarial relevance, the driver's influence, stationarity and observability, which are important for the given task. Dedicated hardware to be fitted into the on-board diagnostics outlet as well as contemporary smartphones are two different insurance telematics platforms for data collection. The paper discusses the properties of the smartphone in the perspective of insurance telematics as a low-cost alternative to the hardwired platforms like the one connected to the vehicle's on-board diagnostics outlet.

Super-resolution (SR) algorithms for multiview videos aim at refining the low-resolution (LR) views using high-frequency detail information from adjacent high-resolution (HR) views. However, to refine a LR view, the state-of-the-art methods only exploit the spatial redundancy of a multiview video. To take full advantage of the spatial and temporal redundancy, a new spatiotemporal SR algorithm is proposed in this paper. Depth-image-based rendering (DIBR) establishes coordinate correspondences between different views. Motion estimation handles object motion between different frames. The high-frequency details are extracted in transform domain and added to LR images. In order to merge the details from different HR images, a combination of global and local weights is proposed. The effectiveness of the proposed algorithm is proved theoretically and shown experimentally.

This paper investigates motion planning for under-actuated systems with impacts, as in legged robots. Some such systems admit decoupling vector fields between impacts, and the system can be thought of as a kinematic system as it moves along the integral curves of these decoupling vector fields. This reduces motion planning to choosing a sequence of decoupling vector fields and impact transition times between these vector fields. Each transition must satisfy the condition that the image of the pre-impact state (through the impact mapping) leads to a post-impact state aligned with the new decoupling vector field. We derive this condition, extending previous work where transitions were only allowed at zero velocity. Our approach combines the benefits of computationally efficient kinematic planning with potentially faster execution times due to the fact that the system does not have to be slowed to zero velocity at the switches. Switches are restricted to a lower-dimensional configuration surface, however. We have applied this approach to motion planning for a planar two-link robot which locomotes by using a single revolute actuator at the joint between the links and by alternately clamping one of two possible pivot points to the ground.

Survey of research papers is not an easy task for novice researchers, because they are not always good at finding all appropriate keywords for the survey. Moreover, it is not easy for them to understand positions of papers in their research fields instantly, even when they use famous search engines like Google Scholar, it may often take a long time for them to find scholarly literature. On the other hand, many researchers have presented citation visualization techniques for surveying research papers. However, it is still often difficult to observe the complicated relations across multiple research fields or traverse the entire relations in their interest. In this paper, we proposed a visualization technique for citation networks applying topic-based paper clustering. Our technique categorizes papers applying LDA (Latent Dirichlet Allocation), and constructs clustered networks consisting of the papers.

This paper examines the current CT2 system and proposes a simple method of capacity expansion using embedded ADPCM coding. Existing objective measures of speech quality are analyzed based on a simple error model.

Re documentation and design recovery are two important areas of reverse engineering. Detection of recurring organizations of classes and communicating objects, called Software Patterns, supports this process [1]. Many approaches to detect Software Patterns which have been published in the past years suffer from the problems of necessity of reference library, performance and language compatibility. This paper presents a model to solve those problems in software pattern detection. The proposed model solves the problem of necessity of reference library by detecting software patterns using Formal Concept Analysis (FCA). The proposed model solves the problem of performance by using the most efficient algorithm CMCG (Concept-Matrix based Concepts Generation) for the construction of concept lattice, which is the core data structure of FCA [3]. The proposed model solves the problem of language compatibility by using the language independent Meta model called MOOSE for taking the input information. The validity of this model was proved in theory and by experiment.

In this paper, we present a dynamic model for simulating a car-like robot with trailer taking into account suspension system and tires deformations. The model describing the wheel/ground contact is a linear model and the joint tractor/trailer is modeled as a spherical-joint. The obtained results are compared with those given by the Pc-Crash software. We noted a good correlation for various scenarios. Furthermore, the proposed model has been successfully applied to study the unbalanced braking in a straight line and the jack-knife problem.

In technical study programs on the bachelor level the focus is mainly directed on the scientific education in theory and practice. Publication is usually started during the PhD phase when students write their first scientific papers. During the last years some very successful projects were made at the university of applied sciences Regensburg to motivate bachelor students doing their first own small publications. The results of these projects are presented in this paper and ideas how students can publish are given.

Machine vision based automatic apparatus is a necessary component of an automated production line. In this paper, taking can-end surface defect detection as an example, we presented a visual inspector and proposed a new surface defect detection framework. Firstly, the Region of Interest (ROI) of the input image is got by circle detection and prior radius knowledge of can-end. Then, the saliency map and texture filtering image are computed to overcome the problems of irregular texture and non-uniform illumination. Finally, all suspected defects are obtained by saliency map segmentation, connected component analysis. Following, the size, the average saliency value and the mean texture filtering value of each suspected defective region are calculated, and the 3-dimensional features are used to distinguish true defects in the central panel region of can-end. We employ the designed equipment to grab can-end images and do tests divided into four groups on the grabbed images. The accuracy is 98.16% and the execution time is about 65.7 milliseconds. Experimental results demonstrate that the proposed method can inspect faint and low contrast defect accurately. Meanwhile, the proposed method is simple and computationally efficient and meets the high speed of industrial automation.

Video synopsis provides a means for fast browsing of activities in video. Principal background selection (PBS) is an important step in video synopsis. Existing methods make PBS in an offline way and at a high memory cost. In this paper we propose a novel background selection method, ``online principal background selection'' (OPBS). The OPBS selects n principal backgrounds from N backgrounds in an online fashion with a low memory cost, making it possible to build an efficient online video synopsis system. Another advantage is that, with OPBS, the selected backgrounds are related to not only background changes over time but also video activities. Experimental results demonstrate the advantages of the proposed OPBS.

This paper discusses an optical filter designed using the two-dimensional (2D) photonics crystal. The filter has been designed to work in Dense Wavelength Division Multiplexing (DWDM) communication using ultra cell resonant cavity. The filter analysis was initially carried out by changing the attributes of photonic crystal such as radius of inner ring rods and refractive index. Hence, it is possible to tune the wavelengths with characteristics according to DWDM standard. The filter is designed to work in 1552 nm, 1553 nm, 1554 nm, 1555 nm, 1556 nm, 1557 nm and 1558 nm with 1nm channel spacing and 0.2 nm spectral linewidth, 96 % to 100 % transmission efficiency, and quality factor to be 8000 respectively. The proposed filter was designed and simulated with Finite-Difference Time-Domain (FDTD) algorithms and the results are discussed at the end for the use in Photonic Integrated Circuits.

Microcontroller devices mass-produced by the industry often include built-in mixed-signal analog-to-digital conversion circuitry. Testing of these converters embedded into an otherwise purely digital integrated circuit requires using additional equipment, extends test time, and ultimately leads to higher cost. A traditional test set-up would include Automatic Test Equipment (ATE) system as well as an external rack-and-stack device for analog-to-digital and digital-to-analog converter testing. This paper proposes to substitute this external device with a simple electronic circuitry placed on the ATE load-board.

4th International Conference on Problems of Cybernetics and Informatics (PCI) -- SEP 12-14, 2012 -- Baku, AZERBAIJAN, WOS: 000320337500173, In this paper the control system with integral constraint on the controls is studied. It is assumed that the behavior of the system is described by an affine Volterra integral equation which is nonlinear with respect to the state vector and is linear with respect to the control vector. The closed ball of the space L-p (p > 1) with gives radius mu(0) and centered at the origin, is chosen as the set of admissible control functions. Compactness of the set of trajectories and existence of the optimal trajectories in the optimal control problems with semi-continuous cost functionals are proved., IEEE

This paper analyzes the robustness of input-shaped model reference control when applied to a double-pendulum crane using a linear single-pendulum crane as the reference model. The single- and double-pendulum crane dynamics are derived and then used to develop the input-shaped model reference control scheme. The robustness of the controller is enhanced to handle both parameter variations and the system order difference between the reference model and the plant. The natural frequencies of the cranes are calculated and utilized to design a three-mode zero-vibration input shaper. A Lyapunov control law using only the states associated with the first mode is derived. The robustness of the proposed controller in state tracking and oscillation suppression performances are analyzed and verified via numerical simulations and experiments. The controller has good robustness to the parameter estimation errors and the fundamental system order difference between the reference model and the plant.

This work describes a general concept for modeling weather phenomena as renewable energy resources. The model considers all typical effects, like time-variance, realistic rates of change, the causality relation between different weather phenomena and satisfying the reference distribution functions. The focus of this work is to design a continuous model, similar to a weather generator, with a simple analytical description. This paper illustrates the concept by a specific implementation for global horizontal irradiance, air temperature and wind speed. We describe the model itself and the data analysis to determine the model parameters. This specific implementation and the concept is validated by designing a model from a 8 year reference dataset. The results show a similar behavior to the recorded data. Only rare, extreme phenomenas are modeled limitedly.

Multi-level AC-AC converter has the advantages of reducing switch voltage stress, adapting to high voltage input and reducing waveform distortion. In this paper, a symmetrical switched capacitor multi-level (SSCML) AC-AC converter is studied. The switched capacitor (SC) technology is introduced into the AC-AC converter, which has the advantages of small size, high efficiency and high power density. Firstly, the topology of SSCML AC-AC converter and its control strategy are introduced. Then, the working principle of the topology is analyzed, and the relationship between input voltage and output voltage is derived in detail, as well as the expression of switch voltage stress. Finally, a 300W prototype is built to verify the proportional relationship between input voltage and output voltage. The prototype and experimental results prove that the multi-level AC-AC converter using SC technology has the advantages of small size and low voltage stress. The experimental results also prove that the voltage stress is proportional to the modulation ratio, which is the key to reducing the voltage stress.

Analysing the traversability from the point cloud input is a critical task for mobile robot navigation. However, there is no mature method for mobile robots to exploring complicated 3D environments, especially those with multi-layered roads. This paper proposes a new traversability map based on the point cloud input, and the map will help analyze where the mobile robot can move in the whole space. The proposed 3D traversability map consists of nodes and edges generated according to the mobile robot’s geometry and driving performance. Nodes represent where the robot can be placed, and edges indicate the cost of moving to another node. The traversability map is stored in digraph form and is convenient to be applied to path planning. Experiments show the successful results of traversability map generation and path planning with D algorithm in different situations.

Truncated multiplication can be used to significantly reduce the power dissipation for applications that do not require correctly-rounded results. This paper presents an efficient method for truncated multiplication called hybrid-correction truncation that utilizes the advantages of two previous methods to obtain lower average and maximum absolute error. Comparisons are presented contrasting power, area, and delay for all three methods compared to standard parallel multipliers. Estimates indicate that hybrid truncated multipliers dissipate slightly less power and consume slightly less area than previous methods for truncated multiplication. In addition, utilization of the hybrid truncation method can provide a method for altering the implementation within certain limits to meet a given precision.

Sign language is the most natural and expressive way for the hearing impaired. Its most appealing application is the development of more effective and friendly interfaces for human-machine interaction. Gestures are a natural and powerful way of communication. A hand gesture recognition system can provide an opportunity for a mute person to communicate with normal people without the need of an interpreter. In this paper we proposed a novel technology for hand gesture recognition which is based on thinning of segmented image.

In this paper, an experimental validation of vertical forces estimation is presented. An original method using high order sliding mode observer is developed. The test bench is a static vehicle excited vertically by hydraulic jack. It's equipped by different sensors in order to measure its dynamics. Real time tests are done and results are presented in this paper.

Quality of Service (QoS) assurance in Wireless Sensor Network (WSN) is a tough task, and it is more exciting due to the scarcity of resources. The requirement of different WSN applications running over has different constraints. In QoS, routing protocol the network has to balance the traffic. This paper presents a novel heuristic routing algorithm known as QoS Assured Multi-Objective Hybrid Routing Algorithm (Q-MOHRA) for Heterogeneous WSN. Q-MOHRA takes into account the link (energy, hop count, link quality indicator etc.) and path (jitter) metrics for optimal path selection. The performance of Q-MOHRA is evaluated through intensive simulation and equated with Simple Hybrid Routing Protocol (SHRP) and Dynamic Multi-objective Routing Algorithm (DyMORA). The metrics such as Average Energy Consumption, Residual Energy, Packet Delivery Ratio, Jitter, and Normalized Routing Load are used for comparison. The performance of Q-MOHRA has been observed to outclass SHRP and DyMORA. It improves the Packet Delivery Ratio (PDR) by 13.72% as compared to SHRP and 28 % as compared to DyMORA. Q-MOHRA outperforms SHRP and DyMORA in terms of Average Energy Consumption (AEC) by a factor of 4.2 % and 2.3 %.

IoT contains a large amount of data as well as privacy sensitive information. This information can be easily identified by the various cyber-attackers. Attackers may steel the data or they can introduce viruses and other malicious software to damage the network. So to overcome these issues, we need to establish an efficient security mechanism for data protection in IoT systems. Advanced Encryption standard is one of the popular security protocols for IoT systems. The main disadvantage of this standard is power consumption for large sized IoT networks. In this paper we proposed an novel mechanism for secure communication in large sized IoT systems. In our design, we use a Hash based Message Authentication Code (HMAC) and a privacy-preserving communication protocol for chaos-based encryption. We observe that proposed mechanism consumes relatively less power over AES with less storage resources.

Consumer generated contents on social media can provide insights and intelligence for firms to improve their performance. In this paper, we highlight the significance of firm generated content (FGC) on social media in supply chain context. Drawing upon social capital theory, this study uses an advanced sentiment analysis approach to examine the impact of FGC effect on supply chain performance. Information sharing and collaboration are identified as two key FGC elements affecting supply chain performance. We discuss and explain major implications of these FGC elements in this paper. Based on the insight gained from the analyses, this paper not only can help academicians understand how FGC can influence the outcome of a supply chain, but also can guide practitioners to adjust their supply chain strategies to have a sustainable competitive advantage.

Given an image, scene understanding is the process of segmenting and identifying the objects present, and classifying the overall scene. Several frameworks already exist to perform these tasks coherently but training of their probabilistic models is time consuming thereby limiting their scalability. This paper presents a scalable framework adopting an object-based approach. The steps taken by the algorithm are saliency detection for unsupervised object discovery, graph-cut for object segmentation, bag-of-features for object classification and binary decision trees for scene classification. A region of interest (ROI) detector is proposed to automatically provide object location priors from saliency maps for graph-cut. We tested our system on a novel NUS/NTU dataset and compared the scene classification accuracy using different classifiers. Unlike other existing frameworks, the proposed algorithm is scalable and can easily accommodate more object and scene classes.

Based on the principle of piezoelectric driving and ultrasonic near-field levitation technology, this paper designs a piezoelectrically driven ultrasonic levitation bearing, which is mainly composed of a rectangular piezoelectric sheet and a metal cylinder. The piezoelectric sheet drives cylinder wall to squeeze air in bearing gap under the action of high-frequency alternating voltage to form a gas squeezed film. According to the theory of viscous fluid mechanics, squeeze film Reynolds equation is derived. From the equation, it can be seen that cylinder radial deformation and squeeze number are the key parameters that determine the bearing capacity of gas squeeze film. With finite element software, radial deformation displacement function of cylinder is obtained, and the relationship between squeeze number and bearing capacity is analyzed by solving Reynolds equation. Based on above simulation and theoretical analysis, bearing is studied experimentally. The experimental results prove that theoretical calculation method is accurate, which has guiding significance for theoretical research and structural design of ultrasonic levitation bearings.

In this paper, we focus on the issue of optimal control policy of rural medical insurance system with high satisfaction degree for the aged, and old people are the main customers for medical insurance company. Firstly, current situation of rural medical insurance in China is analyzed carefully, and statistical data of rural medical insurance in China are given as well. Afterwards, we present an optimal control policy of rural medical insurance system with constraints. In order to verify the effectiveness of the proposed rural medical insurance system which is managed by the optimal control policy, we establish a dataset which include eight administrative villages in China's rural areas. Next, we utilize SPSS toolkit to deal with the sample data. Experimental results demonstrate that the willingness of old people to join the rural medical insurance is enhanced significantly.