检索结果-南通市图书馆

A Novel Synchronization Method in Terahertz Large-Scale Antenna Array System

Chinese Journal of electronics 2021年第5期30卷 956-968页

作者： ZHENG Chen DING Xuhui LIU Dekang BU Xiangyuan AN Sining School of Information and electronics Beijing Institute of Technology Microwave electronics Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology

We focus on the problems of the accurate time delay estimation, the design of training pilots,and hybrid matrix optimization within the large-scale antenna array Terahertz(THz) broadband communication system. In contrast to the existing researches based on narrow-band arrays, we hereby shed light on the time delay estimation of broadband arrays. In THz broadband communication systems, the data symbol duration is relatively short when comparing with the dimension of the antenna array. In large-scale antenna systems,signals received in each antenna are no longer different phase-shifted copies of the same symbol, but completely different symbols in which occasion traditional narrowband structure is no longer suitable. Based on the above conclusion, firstly, we put forward a system model based on large-scale antenna arrays and Time delay line(TDL)structure. Secondly, we deduce the Cramer-Rao lower bound(CRLB) of the time delay estimation, and present a time delay estimation algorithm that could reach the CRLB. Thirdly, by minimizing the CRLB, we address the design of the training pilot and optimized TDL structure under the condition of constant envelope training pilot and modulus TDL structure. Finally, we disclose the numerical simulation results. According to the simulation results, the aforementioned method is workable in reaching the CRLB,the TDL structure can significantly surpass that of the traditional model, and the optimal pilot design method outperforms the pseudo-random pilot structure.

关键词： OFDM modulation time-domain analysis time delay estimation algorithm narrow-band arrays constant envelope training pilot frequency estimation synchronisation hybrid matrix optimization different phase-shifted copies completely different symbols THz broadband communication systems large-scale antenna systems optimal pilot design method Terahertz large-scale antenna array system modulus TDL structure occasion traditional narrow-band structure channel estimation large-scale antenna array Terahertz broadband communication system optimized TDL structure data symbol duration CRLB large-scale antenna arrays array signal processing pseudorandom pilot structure broadband arrays system model accurate time delay estimation antenna arrays Time delay line structure delay estimation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Analysis of highly efficient perovskite solar cells with inorganic hole transport material

引用

Chinese Physics B 2019年第12期28卷 393-399页

作者： I Kabir S A Mahmood department of Electrical and electronics Engineering Bangladesh University of Engineering and Technology

Organo-halide perovskites in planar heterojunction architecture have shown considerable promise as efficient light harvesters in solar cells. We carry out a numerical modeling of a planar lead based perovskite solar cell(PSC) with Cu2ZnSnS4(CZTS) as the hole transporting material(HTM) using the one-dimensional solar cell capacitance simulator(SCAPS-1 D). The effects of numerous parameters such as defect density, thickness, and doping density of the absorber layer on the device performance are investigated. The doping densities and electron affinities of the electron transporting material(ETM) and the HTM are also varied to optimize the PSC performance. It has been observed that a thinner absorber layer of220 nm with a defect density of 1014 cm-3 compared to the reference structure improves the device performance. When doping density of the absorber layer increases beyond 2×1016 cm-3, the power conversion efficiency(PCE) reduces due to enhanced recombination rate. The defect density at the absorber/ETM interface reduces the PCE as well. Considering a series resistance of 5 ?·cm2 and all the optimum parameters of absorber, ETM and HTM layers simultaneously, the overall PCE of the device increases significantly. In comparison with the reference structure, the PCE of the optimized device has been increased from 12.76% to 22.7%, and hence the optimized CZTS based PSC is highly efficient.

关键词： CH3NH3PbI3 Cu2ZnSnS4(CZTS) SCAPS-1D absorption coefficient

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ultra-low power anti-crosstalk collision avoidance light detection and ranging using chaotic pulse position modulation approach

引用

Chinese Physics B 2016年第7期25卷 250-257页

作者：郝杰巩马理杜鹏飞卢宝杰张帆张海涛付星 Center for Photonics and electronics Department of Precision Instrument Tsinghua University

A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors（SPD） and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power.

关键词： collision avoidance chaotic pulse position modulation time-correlated single photon counting anti-crosstalk

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Local Contrast Fusion Based 3D Otsu Algorithm for Multilevel Image Segmentation

引用

IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 200-213页

作者： Ashish Kumar Bhandari Arunangshu Ghosh Immadisetty Vinod Kumar department of electronics and Communication Engineering National Institute of Technology Patna

To overcome the shortcomings of 1 D and 2 D Otsu’s thresholding techniques, the 3 D Otsu method has been *** all Otsu’s methods, 3 D Otsu technique provides the best threshold values for the multi-level thresholding processes. In this paper, to improve the quality of segmented images, a simple and effective multilevel thresholding method is introduced. The proposed approach focuses on preserving edge detail by computing the 3 D Otsu along the fusion phenomena. The advantages of the presented scheme include higher quality outcomes, better preservation of tiny details and boundaries and reduced execution time with rising threshold levels. The fusion approach depends upon the differences between pixel intensity values within a small local space of an image;it aims to improve localized information after the thresholding process. The fusion of images based on local contrast can improve image segmentation performance by minimizing the loss of local contrast, loss of details and gray-level distributions. Results show that the proposed method yields more promising segmentation results when compared to conventional1 D Otsu, 2 D Otsu and 3 D Otsu methods, as evident from the objective and subjective evaluations.

关键词： 1D Otsu 2D Otsu 3D Otsu image fusion local contrast multi-level image segmentation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Decoupling multimode vibrational relaxations in multi-component gas mixtures: Analysis of sound relaxational absorption spectra

引用

Chinese Physics B 2013年第1期22卷 328-337页

作者：张克声王殊朱明丁毅胡轶 department of electronics and Information Engineering Huazhong University of Science and Technology

Decoupling the complicated vibrational-vibrational （V-V） coupling of a multimode vibrational relaxation remains a challenge for analyzing the sound relaxational absorption in multi-component gas mixtures. In our previous work [Acta Phys. Sin. 61 174301 （2012）], an analytical model to predict the sound absorption from vibrational relaxation in a gas medium is proposed. In this paper, we develop the model to decouple the V-V coupled energy to each vibrationaltranslational deexcitation path, and analyze how the multimode relaxations form the peaks of sound absorption spectra in gas mixtures. We prove that a multimode relaxation is the sum of its decoupled single-relaxation processes, and only the decoupled process with a significant isochoric-molar-heat can be observed as an absorption peak. The decoupling model clarifies the essential processes behind the peaks in spectra arising from the multimode relaxations in multi-component gas mixtures. The simulation validates the proposed decoupling model.

关键词： vibrational relaxation sound absorption vibrational-vibrational coupling decoupled singlerelaxation process

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Performance and analytical modelling of halo-doped surrounding gate MOSFETs

引用

Chinese Physics B 2008年第11期17卷 4312-4317页

作者：李尊朝 department of Microelectronics School of Electronics and InformationEngineering Xi’an Jiaotong University

Halo structure is added to sub-100 nm surrounding-gate metal-oxide-semiconductor fieldeffect-transistors （MOS- FETs） to suppress short channel effect. This paper develops the analytical surface potential and threshold voltage models based on the solution of Poisson＇s equation in fully depleted condition for symmetric halo-doped cylindrical surrounding gate MOSFETs. The performance of the halo-doped device is studied and the validity of the analytical models is verified by comparing the analytical results with the simulated data by three dimensional numerical device simulator Davinci. It shows that the halo doping profile exhibits better performance in suppressing threshold voltage roll-off and drain-induced barrier lowering, and increasing carrier transport efficiency. The derived analytical models are in good agreement with Davinci.

关键词： MOSFET surrounding gate compact model halo

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Accurate analysis of ellipsometric data for thick transparent films

引用

Chinese Optics Letters 2011年第5期9卷 81-84页

作者：赵源盛明裕郑玉祥陈良尧 department of Optical Science and Engineering Fudan University department of Optical electronics Information Engineering Shanghai Second Polytechnic University department of electronics Information Engineering Shanghai Business School

Using e-beam evaporation, the ellipsometric parameters of thick transparent films are studied with the modified analysis method for the SiO 2 film samples deposited onto the Si substrate. The ellipsometric parameters are measured at the incidence angles changing from 50 to 70 and in the 3–4.5 eV photon energy range. The error in the conventional method can be significantly reduced by the modified ellipsometric method considering the spatial effect to show good agreement between the theoretical and experimental results. The new method presented in this letter can be applied to other optical measurement of the periodic or non-periodic film structures.

关键词： Optical data processing Optical films Periodic structures Silicon compounds

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptive network fuzzy inference system based navigation controller for mobile robotAdaptive network fuzzy inference system based navigation controller for mobile robot

引用

Frontiers of Information Technology & Electronic Engineering 2019年第2期20卷 141-151页

作者： Panati SUBBASH Kil To CHONG department of electronics and Information Engineering Chonbuk National University Advanced electronics and Information Research Center Chonbuk National University

Autonomous navigation of a mobile robot in an unknown environment with highly cluttered obstacles is a fundamental issue in mobile robotics research. We propose an adaptive network fuzzy inference system(ANFIS) based navigation controller for a differential drive mobile robot in an unknown environment with cluttered obstacles. Ultrasonic sensors are used to capture the environmental information around the mobile robot. A training data set required to train the ANFIS controller has been obtained by designing a fuzzy logic based navigation controller. Additive white Gaussian noise has been added to the sensor readings and fed to the trained ANFIS controller during mobile robot navigation, to account for the effect of environmental noise on sensor readings. The robustness of the proposed navigation controller has been evaluated by navigating the mobile robot in three different environments. The performance of the proposed controller has been verified by comparing the travelled path length/efficiency and bending energy obtained by the proposed method with reference mobile robot navigation controllers, such as neural network, fuzzy logic, and ANFIS. Simulation results presented in this paper show that the proposed controller has better performance compared with reference controllers and can successfully navigate in different environments without any collision with obstacles.

关键词： Adaptive network fuzzy inference system Additive white Gaussian noise Autonomous navigation Mobile robot

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Power Quality Improvement for Grid-connected PV System Based on Distribution Static Compensator with Fuzzy Logic Controller and UVT/ADALINE-based Least Mean Square Controller

引用

Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1289-1299页

作者： Amit Kumar Pradeep Kumar Electrical and electronics Engineering department Natioanl Institute of Technology Sikkim

This paper presents a novel method of power quality enrichment in a grid-connected photovoltaic(PV) system using a distribution static compensator(DSTATCOM). The paper consists of two-step control processes. In the primary step, a fuzzy logic controller(FLC) is employed in the DC-DC converter to extract the peak power point from the PV panel, where the FLC produces a switching signal for the DC-DC *** the secondary step, a unit vector template(UVT)/adaptive linear neuron(ADALINE)-based least mean square(LMS) controller is adopted in the DC-AC converter, i. e., voltage source converter(VSC). The input to this VSC is the boosted DC voltage, which originates from the PV panel as a result of DC-DC conversion. The VSC shunted with the power grid is known as a DSTATCOM, which can maintain the power quality in the distribution system. The UVT controller generates reference source currents from the grid voltages and DC-link *** ADALINE-based LMS controller calculates the online weight according to the previous weights by the sensed load current. The UVT/ADALINE-based LMS controller of a DSTATCOM performs several tasks such as maintaining the sinusoidal source current, achieving a unity power factor, and performing reactive power compensation. The reference current extracted from the UVT/ADALINE-based LMS controller is fed to the hysteresis current controller to obtain the desired switching signal for the VSC. A 100 k W solar PV system integrated into a three-phase four-wire distribution system through a four-leg VSC is designed in MATLAB/Simulink. The performances of the FLC and UVT/ADALINE-based LMS controllers are demonstrated under various irradiances as well as constant temperature and nonlinear loading conditions.

关键词： Adaptive linear neuron least mean square(LMS) fuzzy logic controller(FLC) maximum power point tracking(MPPT) photovoltaic(PV) unit vector template

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intelligent Control System of Textile Mill's Air-conditioning

引用

Journal of Donghua University(English Edition) 2009年第3期26卷 309-312页

作者：巫付专赵方 department of electronics and Information Zhongyuan University of Technology department of electronics and Electric Zhengzhou Technical College

This paper briefly analyzes the present situation of textile mill＇s air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill＇s airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.

关键词： multi-function data acquisition card 485 serial port communication expanding module expert database universal serial interface protocol

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：