期刊文献+
共找到12,749篇文章
< 1 2 250 >
每页显示 20 50 100
Defected Ground Structure Multiple Input-Output Antenna For Wireless Applications
1
作者 Ramya Sridhar Vijayalakshimi Patteeswaran 《Computer Systems Science & Engineering》 SCIE EI 2023年第8期2109-2122,共14页
In this paper,the investigation of a novel compact 2×2,2×1,and 1×1 Ultra-Wide Band(UWB)based Multiple-Input Multiple-Output(MIMO)antenna with Defected Ground Structure(DGS)is employed.The proposed Elect... In this paper,the investigation of a novel compact 2×2,2×1,and 1×1 Ultra-Wide Band(UWB)based Multiple-Input Multiple-Output(MIMO)antenna with Defected Ground Structure(DGS)is employed.The proposed Electromagnetic Radiation Structures(ERS)is composed of multiple radiating elements.These MIMO antennas are designed and analyzed with and without DGS.The feeding is introduced by a microstrip-fed line to significantly moderate the radiating structure’s overall size,which is 60×40×1 mm.The high directivity and divergence characteristics are attained by introducing the microstripfed lines perpendicular to each other.And the projected MIMO antenna structures are compared with others by using parameters like Return Loss(RL),Voltage Standing Wave Ratio(VSWR),Radiation Pattern(RP),radiation efficiency,and directivity.The same MIMO set-up is redesigned with DGS,and the resultant parameters are compared.Finally,the Multiple Input and Multiple Output Radiating Structures with and without DGS are compared for result considerations like RL,VSWR,RP,radiation efficiency,and directivity.This projected antenna displays an omnidirectional RP with moderate gain,which is highly recommended for human healthcare applications.By introducing the defected ground structure in bottom layer the lower cut-off frequencies of 2.3,4.5 and 6.0 GHz are achieved with few biological effects on radio propagation in human body communications.The proposed design covers numerous well-known wireless standards,along with dual-function DGS slots,and it can be easily integrated into Wireless Body Area Networks(WBAN)in medical applications.This WBAN links the autonomous nodes that may be situated either in the clothes,on-body or beneath the skin of a person.This system typically advances the complete human body and the inter-connected nodes through a wireless communication channel. 展开更多
关键词 MIMO-multiple input multiple output defected ground structure WBAN-wireless body area networks ULTRA-WIDEBAND voltage standing wave ratio
下载PDF
Influence of laser energy input mode on joint interface characteristics in laser brazing with Cu-base filler metal 被引量:4
2
作者 李俐群 封小松 陈彦宾 《中国有色金属学会会刊:英文版》 EI CSCD 2008年第5期1065-1070,共6页
The flange butt joints of 1 mm-thick galvanized steel sheets were brazed with CuSi3 as filler metal at different laser heating modes.The microstructures and element distributions of joint interface were investigated b... The flange butt joints of 1 mm-thick galvanized steel sheets were brazed with CuSi3 as filler metal at different laser heating modes.The microstructures and element distributions of joint interface were investigated by SEM and EDS.The results show that there is no obvious interface layer with the circular individual beam heating and lamellar Fe-Si intermetallic compound layer is found with dual-beam laser spot heating.With the irradiation of rectangular laser spot,the joint interface layer is also formed.The layer thickness is larger than that of dual-beam brazing and the layer shape is flat so that intermetallic compounds trend to grow into cellular crystals.Moreover,the interface layer shape also depends on its position in the joint.Under the high heat input,dendritic or granular intermetallic compounds dispersively distribute in brazing seam adjacent to the interface,which is caused by the melting or dissolving of the base metal.According to the results,the brazing quality can be controlled by laser heating mode and processing parameters. 展开更多
关键词 激光铜焊法 接口特征 激光能量输入模式 焊接技术 镀锌钢
下载PDF
基于Input-Output模型的新疆水资源合理配置研究 被引量:2
3
作者 刘爽 李莉 荣伟 《江西农业学报》 CAS 2018年第5期101-105,109,共6页
根据2007和2012年新疆统计年鉴和投入产出表等相关资料,利用Input-output模型和水资源结构偏差系数对国民经济各产业的用水效率、用水效益指数等进行了分析。研究表明:2012年新疆各产业水资源利用效率和效益显著提高,但农业用水消耗量... 根据2007和2012年新疆统计年鉴和投入产出表等相关资料,利用Input-output模型和水资源结构偏差系数对国民经济各产业的用水效率、用水效益指数等进行了分析。研究表明:2012年新疆各产业水资源利用效率和效益显著提高,但农业用水消耗量远高于其产出效益,第三产业和生态环境产业的水资源消耗呈现递减趋势。此外,工业和建筑业的水资源配置较为合理。最后,为促进新疆水资源优化配置提出了相应的对策建议。 展开更多
关键词 水资源 合理配置 input-output模型 新疆
下载PDF
On the Balance Between “Input” and “Output” in College English Teaching
4
作者 刘芳 《海外英语》 2016年第1期239-240,242,共3页
The current college English teaching is usually associated with two discouraging words—"time-consuming"and"inefficient", which badly demands some urgent solutions. On the basis of Krashen's In... The current college English teaching is usually associated with two discouraging words—"time-consuming"and"inefficient", which badly demands some urgent solutions. On the basis of Krashen's Input Hypothesis and Swain's Output Hypothesis, this paper elaborates the indispensable and critical roles respectively of input and output in language learning, and proposes a concept of balanced input and output in college English teaching. The paper also presents some personal suggestions as to how to bring the balance into teaching. 展开更多
关键词 COLLEGE English TEACHING input output BALANCE
下载PDF
Input and Output Balance to Assist in Language Competence
5
作者 马滢颖 《海外英语》 2011年第11X期109-110,共2页
Second Language Acquisition(SLA) education in China suffers from an imbalance between language input and output.Reading and listening are the dominate methods used in the classroom,while speaking and writing are used ... Second Language Acquisition(SLA) education in China suffers from an imbalance between language input and output.Reading and listening are the dominate methods used in the classroom,while speaking and writing are used far less.This paper examines the results that are caused by this imbalanced development of comprehensible output and input.Alternative solutions are examined.The results show the limitations in students' abilities that are commonly based on the current methods of teaching.The implications are that policy makers,curriculum developers and teachers should strive to balance the amount of comprehensible input and output through various means. 展开更多
关键词 SECOND LANGUAGE ACQUISITION LANGUAGE input and output
下载PDF
语言学习过程中的“Input”和“Output”类课程特点分析
6
作者 田凤俊 《教育教学论坛》 2010年第11期165-166,共2页
"Input"和"Output"作为语言学习和运用的两个主要方式,历来备受语言研究者和学习者的关注。因此,有关它们的理论著述和观点也颇多。但主要是如何就二者能很好的在中国英语外语环境中得以有效地应用和实践,如在高校... "Input"和"Output"作为语言学习和运用的两个主要方式,历来备受语言研究者和学习者的关注。因此,有关它们的理论著述和观点也颇多。但主要是如何就二者能很好的在中国英语外语环境中得以有效地应用和实践,如在高校英语专业课程群中得以很好的实施则显得非常必要和实用。将所有英语外语课程按照"Input"和"Output"进行分类并按照课程建模的方式进行课程教学和人才培养是本文讨论的主要任务。 展开更多
关键词 input”和“output 语言学习和习得 课程建模 英语外语教学
下载PDF
From Input to Output-Exploring the Role of Intake in English Learning
7
作者 黄志红 《山东师范大学外国语学院学报(基础英语教育)》 2007年第4期7-17,54,共12页
This paper aims to explore the role of intake in second language learning.Based on her literature review and the case of an English lesson in a Chinese secondary school,the author argues that L2 acquisition does not t... This paper aims to explore the role of intake in second language learning.Based on her literature review and the case of an English lesson in a Chinese secondary school,the author argues that L2 acquisition does not take place directly from input to output.In each sqecific part of L2 acquisition process,intake plays various important roles such as filtering,facilitating in comprehensible input and processing in pushed output.In the Chinese foreign language teaching context,it is also found that L2 acquisition is an arduous task for learners to extract information from the input,utilize it in forming a grammar and produce target language forms accurately and fluently.It is the same with L2 teachers who need to play their roles of a controller,a corrector,an organizer and a prompter in the learning process. 展开更多
关键词 英语教学 第二语言习得 中学 输入 输出 消化吸收
下载PDF
Input and Output in Second Language Acquisition
8
作者 李志远 《学周刊(下旬)》 2015年第7期7-7,共1页
Input and output are two major terminal actions in second language acquisition.For these two actions scholars have carried out a great number of researches.Among them the most famous are Krashen’s Input Hypothesis an... Input and output are two major terminal actions in second language acquisition.For these two actions scholars have carried out a great number of researches.Among them the most famous are Krashen’s Input Hypothesis and Output Hypothesis. 展开更多
关键词 英语学习 学习方法 阅读知识 阅读材料
下载PDF
The Study of Strategies in College English Translation Teaching from the Perspective of Input and Output Theory
9
作者 刘莹 《海外英语》 2014年第14期135-136,共2页
Research on SLA gives highlights to English translation teaching. The second language acquisition is a cognitive process of understanding and outputting the second language by making use of strategies, which contains ... Research on SLA gives highlights to English translation teaching. The second language acquisition is a cognitive process of understanding and outputting the second language by making use of strategies, which contains language input, learners' linguistic knowledge, and language output. This paper analyzes language input and output theory and then proposes that we should stress language input by practice and interaction and at the same time focus on the role of language output in college English translation teaching. 展开更多
关键词 ENGLISH TRANSLATION TEACHING LANGUAGE input langua
下载PDF
A Pilot Study on Task Frequency Effects of Input-Output Cycles on EFL Learners’Oral Proficiency
10
作者 王玉山 《中国校外教育》 2012年第9期40-41,共2页
This paper gives a report of the findings of a pilot study on task frequency effects of input-output cycles on EFL learners'oral proficiency.The results showed that the experimental group made greater progress in ... This paper gives a report of the findings of a pilot study on task frequency effects of input-output cycles on EFL learners'oral proficiency.The results showed that the experimental group made greater progress in complexity and accuracy than control groups.We may come to the conclusion that circular input-out benefits learners most.The study may give some insights for foreign language teachers to give second language learners appropriate tasks in listening and speaking classes. 展开更多
关键词 英语教学 教学方法 阅读教学 英语翻译
下载PDF
Input和Output理论在高职高专英语口语教学中的应用*
11
作者 孙淑梅 《贵州商业高等专科学校学报》 2012年第2期76-78,共3页
影响高职高专学生英语口语训练的因素有很多。从Input和Output(输入和输出)理论的角度,分析影响口语发展障碍的成因,并从教、学双重角度考虑,提出相应的教学对策。
关键词 输入输出 英语口语 障碍 教学对策
下载PDF
Adaptive Control Based on Neural Networks for an Uncertain 2-DOF Helicopter System With Input Deadzone and Output Constraints 被引量:11
12
作者 Yuncheng Ouyang Lu Dong +1 位作者 Lei Xue Changyin Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第3期807-815,共9页
In this paper, a study of control for an uncertain2-degree of freedom(DOF) helicopter system is given. The2-DOF helicopter is subject to input deadzone and output constraints. In order to cope with system uncertaintie... In this paper, a study of control for an uncertain2-degree of freedom(DOF) helicopter system is given. The2-DOF helicopter is subject to input deadzone and output constraints. In order to cope with system uncertainties and input deadzone, the neural network technique is introduced because of its capability in approximation. In order to update the weights of the neural network, an adaptive control method is utilized to improve the system adaptability. Furthermore, the integral barrier Lyapunov function(IBLF) is adopt in control design to guarantee the condition of output constraints and boundedness of the corresponding tracking errors. The Lyapunov direct method is applied in the control design to analyze system stability and convergence. Finally, numerical simulations are conducted to prove the feasibility and effectiveness of the proposed control based on the model of Quanser's 2-DOF helicopter. 展开更多
关键词 2-degree of FREEDOM (DOF) HELICOPTER adaptive control input DEADZONE integral barrier Lyapunov function neural networks output constraints
下载PDF
Dark output characteristic of γ-ray irradiated CMOS digital image sensors 被引量:5
13
作者 MENG Xiangti and KANG A iguo Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第1期79-84,共6页
The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic par... The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic parameters of the dark output images captured atdifferent radiation dose, e.g. average brightness and itsnon-uniformity of dark out- put images, were analyzed by our testsoftware. The primary explanation for the change of the parameterswith the radi- ation dose was given. 展开更多
关键词 CMOS digital image sensor gamma radiation dark output characteristic SI
下载PDF
Robust Output Feedback Control for a Class of Nonlinear Systems with Input Unmodeled Dynamics 被引量:4
14
作者 Ming-Zhe Hou Ai-Guo Wu Guang-Ren Duan 《International Journal of Automation and computing》 EI 2008年第3期307-312,共6页
The robust global stabilization problem of a class of uncertain nonlinear systems with input unmodeled dynamics is considered using output feedback, where the uncertain nonlinear terms satisfy a far more relaxed condi... The robust global stabilization problem of a class of uncertain nonlinear systems with input unmodeled dynamics is considered using output feedback, where the uncertain nonlinear terms satisfy a far more relaxed condition than the existing triangulartype condition. Under the assumption that the input unmodeled dynamics is minimum-phase and of relative degree zero, a dynamic output compensator is explicitly constructed based on the nonseparation principle. An example illustrates the usefulness of the proposed method. 展开更多
关键词 Nonlinear systems global stabilization output feedback input unmodeled dynamics high gain
下载PDF
Comparative and Empirical Study on Vegetable Input-Output Efficiency of Suburban and Rural Areas 被引量:1
15
作者 Li LI Jianmin SHI 《Asian Agricultural Research》 2015年第2期23-28 33,33,共7页
On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable... On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable input-output relationship of suburban areas in 1998-2012. Comparative analysis indicated that the vegetable input-output benefit of suburban area declines,while that of rural area rises; empirical analysis indicated that there is a long-term stable relationship between labor cost of vegetable planting and vegetable income and between material cost of vegetable planting and vegetable income,but the vegetable income itself has certain lag effect,followed by material cost,and the labor cost has minimum influence. Finally,it came up with recommendations for improving suburban vegetable input-output relationship,including improving vegetable input security mechanism,improving farmers' quality and innovation ability,and increasing technological input. 展开更多
关键词 VEGETABLE input VEGETABLE output SUBURBAN area Rur
下载PDF
Sensitivity of Chinese Industrial Wastewater Discharge Reduction to Direct Input Coefficients in an Input-output Context 被引量:3
16
作者 TANG Zhipeng GONG Peiping +1 位作者 LIU Weidong LI Jiangsu 《Chinese Geographical Science》 SCIE CSCD 2015年第1期85-97,共13页
Industrial wastewater discharge in China is increasing with the country′s economic development and it is worthy of concern. The discharge is primarily relevant to the direct discharge coefficient of each sector of th... Industrial wastewater discharge in China is increasing with the country′s economic development and it is worthy of concern. The discharge is primarily relevant to the direct discharge coefficient of each sector of the economy, its direct input coefficient and the final demand in input-output models. In this study, we calculated the sensitivity of the reduction in the Chinese industrial wastewater discharge using the direct input coefficients based on the theory of error-transmission in an input-output framework. Using input-output models, we calculated the direct and total industrial wastewater discharge coefficients. Analysis of 2007 input-output data of 30 sectors of the Chinese economy and of 30 provincial regions of China indicates that by lowering their direct input coefficients, the manufacturers of textiles, paper and paper products, chemical products, smelting and metal pressing, telecommunication equipment, computers and other electronic equipment will significantly reduce their amounts of industrial wastewater discharge. By lowering intra-provincial direct input coefficients to industrial sectors themselves of Jiangsu, Shandong and Zhejiang, there will be a significant reduction in industrial wastewater discharge for the country as a whole. Investment in production technology and improvement in organizational efficiency in these sectors and in these provinces can help lessen the direct input coefficients, thereby effectively achieving a reduction in industrial wastewater discharge in China via industrial restructuring. 展开更多
关键词 工业废水排放 中国经济 直接输入 输入输出 敏感性 上下文 投入产出模型 废水排放系数
下载PDF
Direction-of-arrival estimation for co-located multiple-input multiple-output radar using structural sparsity Bayesian learning 被引量:4
17
作者 文方青 张弓 贲德 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期70-76,共7页
This paper addresses the direction of arrival (DOA) estimation problem for the co-located multiple-input multiple- output (MIMO) radar with random arrays. The spatially distributed sparsity of the targets in the b... This paper addresses the direction of arrival (DOA) estimation problem for the co-located multiple-input multiple- output (MIMO) radar with random arrays. The spatially distributed sparsity of the targets in the background makes com- pressive sensing (CS) desirable for DOA estimation. A spatial CS framework is presented, which links the DOA estimation problem to support recovery from a known over-complete dictionary. A modified statistical model is developed to ac- curately represent the intra-block correlation of the received signal. A structural sparsity Bayesian learning algorithm is proposed for the sparse recovery problem. The proposed algorithm, which exploits intra-signal correlation, is capable being applied to limited data support and low signal-to-noise ratio (SNR) scene. Furthermore, the proposed algorithm has less computation load compared to the classical Bayesian algorithm. Simulation results show that the proposed algorithm has a more accurate DOA estimation than the traditional multiple signal classification (MUSIC) algorithm and other CS recovery algorithms. 展开更多
关键词 multiple-input multiple-output radar random arrays direction of arrival estimation sparseBayesian learning
下载PDF
Fundamental Theories of Second Language Acquisition: The Input Hypothesis, the Output hypothesis, and the Interaction Hypothesis 被引量:1
18
作者 ZHAO Congmin 《Sino-US English Teaching》 2021年第7期192-195,共4页
In the field of applied linguistics,several hypotheses have been proposed for second language acquisition:the Input Hypothesis,the Output hypothesis,and the Interaction Hypothesis.They address the fundamental componen... In the field of applied linguistics,several hypotheses have been proposed for second language acquisition:the Input Hypothesis,the Output hypothesis,and the Interaction Hypothesis.They address the fundamental components of successful second language acquisition respectively.This paper introduces these hypotheses and constructs a comprehensive picture based on them。 展开更多
关键词 input output INTERACTION
下载PDF
Input-output approach to robust stability and stabilization for uncertain singular systems with time-varying discrete and distributed delays 被引量:4
19
作者 Hui-jiao WANG An-ke XUE +1 位作者 Yun-fei GUO Ren-quan LU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第4期546-551,共6页
Based on input-output approach, the robust stability and stabilization problems for uncertain singular systems with time-varying delays are investigated. The parameter uncertainties are assumed to be norm-bounded and ... Based on input-output approach, the robust stability and stabilization problems for uncertain singular systems with time-varying delays are investigated. The parameter uncertainties are assumed to be norm-bounded and the time-varying delays include both discrete delay and distributed delay. By introducing a new input-output model, the time-delay system is embedded in a family of systems with a forward system without time delay and a dynamical feedback uncertainty. A sufficient and necessary condition, which guarantees the system regular, impulse-free and stable for all admissible uncertainties, is obtained. Based on the strict linear matrix inequality, the desired robust state feedback controller is also obtained. Finally, a numerical example is provided to demonstrate the application of the proposed method. 展开更多
关键词 自动控制系统 输入输出系统 线形矩阵系统 计算机
下载PDF
Adaptive controller design based on input-output signal selection for voltage source converter high voltage direct current systems to improve power system stability 被引量:2
20
作者 Abdolkhalegh Hamidi Jamal Beiza +1 位作者 Ebrahim Babaei Sohrab Khanmohammadi 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2254-2267,共14页
An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is w... An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance. 展开更多
关键词 高压直流系统 自适应控制器 控制器设计 输入输出 信号选择 电压源换流器 PHILLIPS-HEFFRON模型 稳定性
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部