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Suitability and Sustainability of Rainwater QualityMonitoring System in Cistern for Domestic Use
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作者 Kenedy A.Greyson 《Journal on Internet of Things》 2023年第1期1-11,共11页
Rainwater harvesting(RWH)systems have been the source of domestic water for many years and still becoming essential in many communities of developing countries.However,due to various reasons,there are several sources ... Rainwater harvesting(RWH)systems have been the source of domestic water for many years and still becoming essential in many communities of developing countries.However,due to various reasons,there are several sources of contamination in the rainwater cistern systems.Dissolved chemicals from the roofing,storage,and conveyance materials,together with the suspended particulate matter from the airborne,are examples of water contamination.In this work,the water quality monitoring system has been designed and implemented.Chemical and physical parameters of water samples were collected from three locations using a data acquisition(DAQ)system and rainwater quality was analyzed using Water Pollution Index(WPI).Results obtained from three locations have been presented. 展开更多
关键词 Cistern DAQ system monitoring system RWH system water pollution WPI
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Gait Recognition by Cross Wavelet Transform and Graph Model 被引量:8
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作者 Sagar Arun More Pramod Jagan Deore 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第3期718-726,共9页
In this paper, a multi-view gait based human recognition system using the fusion of two kinds of features is proposed.We use cross wavelet transform to extract dynamic feature and bipartite graph model to extract stat... In this paper, a multi-view gait based human recognition system using the fusion of two kinds of features is proposed.We use cross wavelet transform to extract dynamic feature and bipartite graph model to extract static feature which are coefficients of quadrature mirror filter(QMF)-graph wavelet filter bank. Feature fusion is done after normalization. For normalization of features, min-max rule is used and mean-variance method is used to find weights for normalized features. Euclidean distance between each feature vector and center of the cluster which is obtained by k-means clustering is used as similarity measure in Bayesian framework. Experiments performed on widely used CASIA B gait database show that, the fusion of these two feature sets preserve discriminant information. We report 99.90 % average recognition rate. 展开更多
关键词 Binary sequences feature extraction identification of persons linear discriminant analysis(LDA)
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Performance analysis and design of MIMO-OFDM system using concatenated forward error correction codes 被引量:3
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作者 Arun Agarwal Saurabh N.Mehta 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第6期1322-1343,共22页
This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shif... This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance. 展开更多
关键词 bit ERROR rate (BER) convolutional CODE (CC) forward ERROR correction peak signal to noise ratio (PSNR) Turbo CODE
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Resistance and Seakeeping Numerical Performance Analyses of a Semi-Small Waterplane Area Twin Hull at Medium to High Speeds 被引量:1
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作者 Giuliano Vernengo Dario Bruzzone 《Journal of Marine Science and Application》 CSCD 2016年第1期1-7,共7页
新半小的 waterplane 区域双胞胎壳(一行) 的水动力学分析对象小、中等的尺寸旅客渡船那样的各种各样的应用合适被介绍。这可以是源于合并二古典形状的一种吸引人的转线路配置:常规一行和快长筏。最后的壳设计与最大的横梁展出像楔的... 新半小的 waterplane 区域双胞胎壳(一行) 的水动力学分析对象小、中等的尺寸旅客渡船那样的各种各样的应用合适被介绍。这可以是源于合并二古典形状的一种吸引人的转线路配置:常规一行和快长筏。最后的壳设计与最大的横梁展出像楔的吃水线形状在严厉;壳与一个很狭窄的入口角度结束,有典型地代表一行容器的一个突出的球状的弓,并且展示完整对严厉安排 waterjet 推进器。我们与如此的建筑群执行对壳的水动力学表演的一个初步的评价的分析目的在常规头波浪在平静的水和经得起海上风浪的能力里以壳的抵抗塑造两个并且把表演与常规一行的作比较。分析用 preliminarily 在一个常规一行容器上被验证的一个边界元素方法被执行。 展开更多
关键词 小水线面双体船 水动力性能 船体阻力 耐波性 数值分析 高转速 SWATH船 船体设计
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Analysis and Modeling of Propagation in Tunnel at 3.7 and 28 GHz 被引量:1
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作者 Md Abdus Samad Dong-You Choi 《Computers, Materials & Continua》 SCIE EI 2022年第5期3127-3143,共17页
In present-day society,train tunnels are extensively used as a means of transportation.Therefore,to ensure safety,streamlined train operations,and uninterrupted internet access inside train tunnels,reliable wave propa... In present-day society,train tunnels are extensively used as a means of transportation.Therefore,to ensure safety,streamlined train operations,and uninterrupted internet access inside train tunnels,reliable wave propagation modeling is required.We have experimented and measured wave propagation models in a 1674 m long straight train tunnel in South Korea.The measured path loss and the received signal strength were modeled with the Close-In(CI),Floating intercept(FI),CI model with a frequency-weighted path loss exponent(CIF),and alpha-beta-gamma(ABG)models,where the model parameters were determined using minimum mean square error(MMSE)methods.The measured and the CI,FI,CIF,and ABG modelderived path loss was plotted in graphs,and the model closest to the measured path loss was identified through investigation.Based on the measured results,it was observed that every model had a comparatively lower(n<2)path loss exponent(PLE)inside the tunnel.We also determined the path loss component’s possible deviation(shadow factor)through a Gaussian distribution considering zero mean and standard deviation calculations of random error variables.The FI model outperformed all the examined models as it yielded a path loss closer to the measured datasets,as well as a minimum standard deviation of the shadow factor. 展开更多
关键词 Path loss shadow factor telecommunications train tunnel wave propagation wireless networks
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Modeling of OFDM Based Transceiver for Broadband Powerline Communication 被引量:1
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作者 Syed Samser Ali Amitabha Bhattacharya Dipak Ranjan Poddar 《Journal of Electromagnetic Analysis and Applications》 2014年第6期125-129,共5页
In the recent past power line communication has emerged as an attractive choice for high speed data transfer and is looked upon as inexpensive and reliable media suitable for broadband internet access, home and office... In the recent past power line communication has emerged as an attractive choice for high speed data transfer and is looked upon as inexpensive and reliable media suitable for broadband internet access, home and office automation, in-vehicle data communication etc. In this paper we present an architecture for the physical layer of a PLC transceiver based on Orthogonal Frequency Division Multiplexing (OFDM) and the impact on multipath distortion for PLC transmission in terms of bit error rate. Since there is no standard PLC channel model available, a widely accepted multipath channel model is used for simulation purpose. Simulation results as well as FPGA synthesis verify the effectiveness of the proposed architecture for PLC modem design at 110 Mbps data rate. 展开更多
关键词 OFDM Power LINE Communication (PLC) MULTIPATH CHANNEL FPGA
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Overlapped Subarray Architecture of an Wideband Phased Array Antenna with Interference Suppression Capability 被引量:1
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作者 Quazi Md. Alfred Tapas Chakravarty Salil Kumar Sanyal 《Journal of Electromagnetic Analysis and Applications》 2013年第5期201-204,共4页
This paper presents a novel architecture of combining the linear array of antenna elements, where each antenna element has digitally selectable true time-delays as weights. Use of time-delays for beam-formation inhere... This paper presents a novel architecture of combining the linear array of antenna elements, where each antenna element has digitally selectable true time-delays as weights. Use of time-delays for beam-formation inherently makes the phased array network a wideband system. In particular, this technique envisage a new method of sharing antenna elements, by fixed overlapped sub-array architecture, which is able to maintain permissible element spacing to avoid grating lobe in antenna pattern. Moreover, this scheme additionally offers an easier null steering capability to the subarray architecture. This method essentially eliminates the need for intensive computation of complex weight vectors attached to each antenna element. 展开更多
关键词 Phased ARRAY SUBARRAY TIME-DELAY Overlapped ARRAY
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Validation of Heat Transfer between Theoretical and Experimental from the Internal Surface of Vertical Tubes with Internal Rings Heated by Electrical Heating Coils 被引量:1
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作者 Ramesh Chandra Nayak Manmatha K.Roul +2 位作者 Ipsita jena Ipsita Dash Ashish Ku.Patra 《Electrical Science & Engineering》 2019年第1期41-47,共7页
The comparison between experimental and theoretical heat transfer inside heated vertical channels that dissipate heat from the internal surface with and without internal rings is studied.The experimental setup consist... The comparison between experimental and theoretical heat transfer inside heated vertical channels that dissipate heat from the internal surface with and without internal rings is studied.The experimental setup consists of a circular pipe which is heated electrically by providing constant heat flux on the wall.The theoretical and experimental analysis is conducted in several pipes of same diameter but different lengths.The length of the pipe varies from 450 mm to 850 mm.The length to diameter ratios are taken as L/D=10,12.22,15.56,and 18.89.The value of imposed heat flux varies from 250 to 3340 W/m2.The internal ring thickness varies from 4 mm to 8 mm.separation distance between the internal rings varies from 75mm to 300 mm.The theoretical results are compared with experimental data to ascertain numerical accuracy of the method.The effects of L/D ratio,thickness of internal rings and separation distance on the heat transfer performance are studied.The experimental result is compared with theoretical,theoretical results are found by using ANSYS.In this study theoretical result for wall temperature along the height of tube,fluid temperature at exit of tube are compared with experimental data. 展开更多
关键词 Heat transfer Natural CONVECTION PROTRUSION thickness Separation distance GEOMETRICAL SIZES
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A highly sustainable multi-band orthogonal wavelet code division multiplexing UWB communication system for underground mine channel
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作者 Athar Ravish Khan Sanjay M.Gulhane 《Digital Communications and Networks》 SCIE 2018年第4期264-276,共13页
The underground mine channel is highly hostile for communication.A sustainable communication system is required to be integrated as a multipurpose system capable of transferring all types of information such as data, ... The underground mine channel is highly hostile for communication.A sustainable communication system is required to be integrated as a multipurpose system capable of transferring all types of information such as data, voice and video on identical infrastructure.With its large bandwidth,the Ultra Wide Band (UWB)provides a promising solution to satisfy these requirements.The Multi-Band Orthogonal Frequency Division Multiplexing (MBOFDM)UWB system provides high resilience to Inter-Symbol Interference (ISI)caused by multipath fading channels.This study compares the performance of various existing multi-band UWB systems in the IEEE UWB channel and underground mine channel:MBOFDM,Multi-Band Orthogonal Frequency Code Division Multiplexing (MBOFCDM)and Multi-Band orthogonal Wavelet Division Multiplexing (MBOWI)M).Further,the application of 2D spreading to the MBOWI)M UWB system is attempted,and as a result,the Multi-Band Orthogonal Wavelet Code Division Multiplexing (MBOWCDM)UWB system is proposed.The performance of the MBOWCDM system in the IEEE UWB channel and underground mine channel is investigated.The performance of the MBOWCDM UWB system is observed to be superior to those of other multi-band UWB systems.Moreover,the MBOWCDM UWB system supports a higher data rate with low complexity and lower overheads. 展开更多
关键词 MBOFDM MBOFCDM MBOWDM MBOWCDM 2D SPREADING UNDERGROUND MINE CHANNEL
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Influence of self-heating on the millimeter-wave and terahertz performance of MBE grown silicon IMPATT diodes
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作者 S.J.Mukhopadhyay Prajukta Mukherjee +1 位作者 Aritra Acharyya Monojit Mitra 《Journal of Semiconductors》 EI CAS CSCD 2020年第3期13-22,共10页
The influence of self-heating on the millimeter-wave(mm-wave)and terahertz(THz)performance of double-drift region(DDR)impact avalanche transit time(IMPATT)sources based on silicon(Si)has been investigated in this pape... The influence of self-heating on the millimeter-wave(mm-wave)and terahertz(THz)performance of double-drift region(DDR)impact avalanche transit time(IMPATT)sources based on silicon(Si)has been investigated in this paper.The dependences of static and large-signal parameters on junction temperature are estimated using a non-sinusoidal voltage excited(NSVE)large-signal simulation technique developed by the authors,which is based on the quantum-corrected drift-diffusion(QCDD)model.Linear variations of static parameters and non-linear variations of large-signal parameters with temperature have been observed.Analytical expressions representing the temperature dependences of static and large-signal parameters of the diodes are developed using linear and 2nd degree polynomial curve fitting techniques,which will be highly useful for optimizing the thermal design of the oscillators.Finally,the simulated results are found to be in close agreement with the experimentally measured data. 展开更多
关键词 IMPATT oscillators linear temperature coefficient SELF-HEATING thermal runway quadratic temperature coefficient
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Analysis of Wide-Bandgap Material OPFET UV Detectors for High Dynamic Range Imaging and Communication Applications
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作者 Jaya V. Gaitonde Rajesh B. Lohani 《Communications and Network》 2019年第4期83-117,共35页
The ultraviolet (UV) photoresponses of Wurtzite GaN, ZnO, and 6H-SiC-based Optical Field Effect Transistor (OPFET) detectors are estimated with an in-depth analysis of the same considering the generalized model and th... The ultraviolet (UV) photoresponses of Wurtzite GaN, ZnO, and 6H-SiC-based Optical Field Effect Transistor (OPFET) detectors are estimated with an in-depth analysis of the same considering the generalized model and the front-illuminated model for high resolution imaging and UV communication applications. The gate materials considered for the proposed study are gold (Au) and Indium-Tin-Oxide (ITO) for GaN, Au for SiC, and Au and silver dioxide (AgO2) for ZnO. The results indicate significant improvement in the Linear Dynamic Range (LDR) over the previously investigated GaN OPFET (buried-gate, front-illuminated and generalized) models with Au gate. The generalized model has superior dynamic range than the front-illuminated model. In terms of responsivity, all the models including buried-gate OPFET exhibit high and comparable photoresponses. Buried-gate devices on the whole, exhibit faster response than the surface gate models except in the AgO2-ZnO generalized OPFET model wherein the switching time is the lowest. The generalized model enables faster switching than the front-illuminated model. The switching times in all the cases are of the order of nanoseconds to picoseconds. The SiC generalized OPFET model shows the highest 3-dB bandwidths of 11.88 GHz, 36.2 GHz, and 364 GHz, and modest unity-gain cut-off frequencies of 4.62 GHz, 8.71 GHz, and 5.71 GHz at the optical power densities of 0.575 μW/cm2, 0.575 mW/cm2, and 0.575 W/cm2 respectively. These are in overall, the highest detection-cum-amplifi-cation bandwidths among all the investigated devices. The same device exhibits the highest LDR of 73.3 dB. The device performance is superior to most of the other existing detectors along with comparable LDR, thus, emerging as a high performance photodetector for imaging and communication applications. All the detectors show considerably high detectivities owing to the high responsivity values. The results have been analyzed by the photovoltaic and the photoconductive effects, and the series resistance effects and will aid in conducting further research. The results are in line with the experiments and the commercially available software simulations. The devices will greatly contribute towards single photon counting, high resolution imaging, and UV communication applications. 展开更多
关键词 UV OPFET GaN SiC ZnO Au ITO AgO2 High Dynamic Range Imaging PHOTON COUNTING COMMUNICATION
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A BCH code assisted modified NCO based LSPF-DPLL topology for Nakagami-m, Rayleigh and Rician fading channels
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作者 Sabyasachi Bhattacharyya Aradhana Misra Kandarpa Kumar Sarma 《Digital Communications and Networks》 SCIE 2019年第2期102-110,共9页
In spite of the rapid developments in communication technologies over the past few decades, which include attractive features offered by the presently used 3G/4G systems,让 continues to be a challenge to render adequa... In spite of the rapid developments in communication technologies over the past few decades, which include attractive features offered by the presently used 3G/4G systems,让 continues to be a challenge to render adequate services with the exponential rise in the number of users and applications. However, efficient alternatives, including 5G methods, are being explored to mitigate this problem. Such systems also aspire to render sustained coverage with lesser constraints on power and Quality of Service (QoS). Today, versatile Digital Phase Locked Loop (DPLL) based packages find place as communication receivers. Of late, a Least Square Polynomial Fitting DPLL (LSPF-DPLL) with Modified Phase Resolving Numerically Controlled Oscillator (MPR-NCO), which demonstrates excellent time performance and maintains satisfactory error rates, was proposed. A Bose, Chaudhuri, and Hocquenghem (BCH) channel code assisted version of the MPR-NCO based LSPF-DPLL system is presented here. The proposed system exhibits better B让 Error Rate (BER), throughput, and baud rate levels over the previously proposed uncoded version. 展开更多
关键词 Coding FADING Frequency tracking Least SQUARES Phase recovery
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Multi-Objective High-Fidelity Optimization Using NSGA-III and MO-RPSOLC
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作者 N.Ganesh Uvaraja Ragavendran +2 位作者 Kanak Kalita Paras Jain Xiao-Zhi Gao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第11期443-464,共22页
Optimizing the performance of composite structures is a real-world application with significant benefits.In this paper,a high-fidelity finite element method(FEM)is combined with the iterative improvement capability of... Optimizing the performance of composite structures is a real-world application with significant benefits.In this paper,a high-fidelity finite element method(FEM)is combined with the iterative improvement capability of metaheuristic optimization algorithms to obtain optimized composite plates.The FEM module comprises of ninenode isoparametric plate bending element in conjunction with the first-order shear deformation theory(FSDT).A recently proposed memetic version of particle swarm optimization called RPSOLC is modified in the current research to carry out multi-objective Pareto optimization.The performance of the MO-RPSOLC is found to be comparable with the NSGA-III.This work successfully highlights the use of FEM-MO-RPSOLC in obtaining highfidelity Pareto solutions considering simultaneous maximization of the fundamental frequency and frequency separation in laminated composites by optimizing the stacking sequence. 展开更多
关键词 COMPOSITES finite element OPTIMIZATION PARETO swarm intelligence
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Wearable Antenna for Power Efficient On-Body and Off-Body Communications
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作者 Mohammad Monirujjaman Khan Md. Azizur Rahman +1 位作者 Md. Abu Talha Tarannum Mithila 《Journal of Electromagnetic Analysis and Applications》 2014年第9期238-243,共6页
A novel dual-band and diverse radiation pattern antenna is proposed for power efficient on-body and off-body communications intended for various applications in healthcare and sport monitoring. The antenna is dual ban... A novel dual-band and diverse radiation pattern antenna is proposed for power efficient on-body and off-body communications intended for various applications in healthcare and sport monitoring. The antenna is dual band at 2.45 GHz (ISM band) with omnidirectional radiation pattern over the body surface to communicate power efficiently with other co-located body worn devices and at 1.9 GHz (PCS band), it has directive radiation pattern towards off the body to communicate from on-body device to off-body devices. The free space and on-body performances of the antenna are investigated by both simulation and experiment. The antenna shows very good on-body radiation efficiency of 58% at 2.45 GHz and 61% at 1.9 GHz. Good on-body gain is noticed at both frequency bands. Results show that the gain of the proposed antenna increases by 4.7% at 2.45 GHz and 3.2% at 1.9 GHz when placed on the body. 展开更多
关键词 Dual Band Diverse Radiation Pattern Power EFFICIENT On-Body COMMUNICATIONS Power EFFICIENT Off-Body COMMUNICATIONS Body-Centric Wireless COMMUNICATIONS
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Experimental Study of On-Body Radio Channel Performance of a Compact Ultra Wideband Antenna
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作者 Mohammad Monirujjaman Khan Qammer H. Abbasi +1 位作者 Mirazur Rahman Ratil Hasnat Ashique 《Journal of Electromagnetic Analysis and Applications》 2015年第1期1-9,共9页
In this paper, on-body radio channel performance of a compact ultra wideband (UWB) antenna is investigated for body-centric wireless communications. Measurement campaigns were first done in the chamber and then repeat... In this paper, on-body radio channel performance of a compact ultra wideband (UWB) antenna is investigated for body-centric wireless communications. Measurement campaigns were first done in the chamber and then repeated in an indoor environment for comparison. The path loss parameter for eight different on-body radio channels has been characterized and analyzed. In addition, the path loss was modeled as a function of distance for 34 different receiver locations for propagation along the front part of the body. Results and analysis show that, compared with anechoic chamber, a reduction of 16.34% path loss exponent is noticed in indoor environment. The antenna shows very good on-body radio channel performance and will be a suitable candidate for future efficient and reliable body-centric wireless communications. 展开更多
关键词 On-Body Radio Channel PATH LOSS Ultra WIDEBAND (UWB) Antenna Body-Centric Wireless COMMUNICATIONS
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Wireless Body Area Network: An Overview and Various Applications
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作者 Md. Taslim Arefin Mohammad Hanif Ali A. K. M. Fazlul Haque 《Journal of Computer and Communications》 2017年第7期53-64,共12页
Over the past years a booming interest is comprehended in the field of wireless communication for the development of a monitoring system to observe human vital organs activities remotely. Wireless Body Area Network (W... Over the past years a booming interest is comprehended in the field of wireless communication for the development of a monitoring system to observe human vital organs activities remotely. Wireless Body Area Network (WBAN) is such network that provides a continuous monitoring over or inside human body for a long period and can support transmission of real time traffic such as data, voice, video to observe the status of vital organs functionalities. In this paper an overview of WBAN technology and its requirements has been narrated. The aim of this paper was to offer a suitable and appropriate wireless technology for deploying WBAN. Several suitable short range wireless communication technologies that can be adopted in WBAN have also been discussed. Finally numerous applications in the field of medical and non-medical sectors using WBAN technology have been outlined. 展开更多
关键词 WBAN WiFi BLUETOOTH ZigBee Monitoring SENSORS WBAN APPLICATIONS
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Polarization and Breakdown Analysis of AlGaN Channel HEMTs with AlN Buffer
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作者 Godwin Raj Mohan Kumar Chandan Kumar Sarkar 《World Journal of Condensed Matter Physics》 2015年第3期232-243,共12页
We have demonstrated the first carrier density model for AlGaN channel with AlN buffer using spontaneous and piezoelectric polarization comparison with experimental and theoretical results. From the results we proved ... We have demonstrated the first carrier density model for AlGaN channel with AlN buffer using spontaneous and piezoelectric polarization comparison with experimental and theoretical results. From the results we proved that the formation of 2DEG in undoped structure relied both on spontaneous and piezoelectric polarization. The electron distribution of Al concentration (0 < x < 0.5) was measured for both AlGaN channel and barrier. Barrier thickness assumed between 20 and 25 nm for validating the experimental results. The carrier concentration was observed at the specific interface of the N- and Ga-face by assuming x1, x2 = 0. The model results are verified with previously reported experimental data. 展开更多
关键词 ALGAN CHANNEL Sheet CARRIER Concentration Model N- and Ga-face POLARIZATION High BREAKDOWN Total Induced Net Interface POLARIZATION
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Mean Territorial Energy Based Clustering Protocol for Randomly Deployed Wireless Sensor Networks
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作者 Rohit D. Gawade Sanjay L. Nalbalwar 《Advances in Internet of Things》 2017年第3期87-96,共10页
Clustering algorithms can balance the power consumption of energy constraint wireless sensor networks. This paper proposes a new clustering protocol called Mean Territorial Energy Based Clustering Protocol (MTEP) for ... Clustering algorithms can balance the power consumption of energy constraint wireless sensor networks. This paper proposes a new clustering protocol called Mean Territorial Energy Based Clustering Protocol (MTEP) for randomly deployed wireless sensor networks. In MTEP, cluster heads are selected according to residual energy and location information of a node in current round as well as mean territorial energy and total base station distance of node’s corresponding cluster territory in previous round. Energy consumption in conventional protocols becomes unbalanced because of clusters having different lengths. Proposed MTEP protocol addresses this problem by setting thresholds on cluster length and node to cluster head distance for producing equal length clusters. Simulation results show that MTEP protocol extends network lifetime and stability with reduction in energy dissipation compared to other clustering protocols such as LEACH and REAC. 展开更多
关键词 CLUSTER Head Base STATION CLUSTERING PROTOCOL Energy Efficiency Network LIFETIME
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Investigation on Lanthanum Fluoride as a Novel Cathode Buffer Material Layer for the Enhancement of Stability and Performance of Organic Solar Cell
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作者 Md. Shahinul Islam Md. Golam Saklayen +2 位作者 Md. Ferdous Rahman Hartmut Baerwolff Abu Bakar Md. Ismail 《Optics and Photonics Journal》 2014年第10期280-287,共8页
This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl... This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) polymer blend at 1:1 ratio. Electron-beam evaporation at room temperature was used to deposit 3 and 5 nm thick LaF3 layer. A very smooth surface of LaF3 with an average roughness of 0.2 nm has been observed by the Atomic Force Microscope (AFM) that is expected to prevent diffusion of cathode metal ion through it and thereby enhance the lifetime and stability of OSC. Huge enhancement of JSC and VOC was also observed for 3 nm-thick LaF3 CBL. Several excellent features of the LaF3 layer such as, transporting electron through tunneling, blocking of holes to the cathode, minimizing recombination, protecting the photoactive polymer from ambient oxygen, and reducing degradation/oxidation of any low work function layer at the cathode interface, might have contributed to the performance enhancement of OSC. The experimental findings indicate the promise of LaF3 to be an excellent CBL material for OSC. 展开更多
关键词 ORGANIC Semiconductor Photoactive Polymer ORGANIC SOLAR Cell Bulk Heterojunction SOLAR Cells CATHODE BUFFER Layer LANTHANUM FLUORIDE Spin Coating E-Beam Evaporation
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Sources of Variability in the Use of Standardized Perfusion Value for HCC Studies
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作者 Michela D’Antò Mario Cesarelli +2 位作者 Francesco Fiore Maria Romano Paolo Bifulco 《Open Journal of Medical Imaging》 2012年第2期33-40,共8页
Hepatocellular carcinoma (HCC) is one of the world’s most common malignant tumours. As known, liver tumour tissue is characterised by an increased blood supply related to neoangionesis which causes an increased arter... Hepatocellular carcinoma (HCC) is one of the world’s most common malignant tumours. As known, liver tumour tissue is characterised by an increased blood supply related to neoangionesis which causes an increased arterial vascularisation. CT Perfusion Imaging is an important, non invasive, technique for qualitative assessment of tissue perfusion after contrast agent administration. Nevertheless, being able to reliably quantifying angiogenesis is increasingly important to both the evaluation of the disease progression and monitoring of the therapeutic response of HCC. With this in mind, we believe that could be helpful to employ Standardised Perfusion Value (SPV), which has the potential to be a useful non-invasive marker of HCC angiogenesis. However, before using SPV in clinical practice, we need to verify its reliability. There are different causes of variability in applying the SPV index, e.g., the technical specifications of the CT system employed and the image processing system. In this paper the authors will analyse the variability of the BFa estimates and the variability due to the calibration procedure of the CT system, this with the objective of verifying how these factors affects SPV values. In our case, perfusion MDCT images of seventeen HCC patients were analysed. A software application, based on maximum slope method, was developed to compute BFa and SPV values. Four radiologists were involved in images processing evaluating variability related to ROI selection;each radiologist repeated the ROI drawing four times on the same image set. We computed the k calibration factor in order to evaluate SPV variability due to calibration protocol of CT systems. Results show that calibration factor variance, due to the position in the gantry, is less than BFa variability. So, we conclude that, when daily calibration is preferred, a simplified protocol, which neglects the dependence of K factor from the position, may be utilised;at least until the intrinsic variability of perfusion parameter computation operator-dependent will be reduced. 展开更多
关键词 CT PERFUSION Calibration LIVER TUMOUR
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