期刊文献+
共找到2,317篇文章
< 1 2 116 >
每页显示 20 50 100
A redundant subspace weighting procedure for clock ensemble
1
作者 徐海 陈煜 +1 位作者 刘默驰 王玉琢 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期435-442,共8页
A redundant-subspace-weighting(RSW)-based approach is proposed to enhance the frequency stability on a time scale of a clock ensemble.In this method,multiple overlapping subspaces are constructed in the clock ensemble... A redundant-subspace-weighting(RSW)-based approach is proposed to enhance the frequency stability on a time scale of a clock ensemble.In this method,multiple overlapping subspaces are constructed in the clock ensemble,and the weight of each clock in this ensemble is defined by using the spatial covariance matrix.The superimposition average of covariances in different subspaces reduces the correlations between clocks in the same laboratory to some extent.After optimizing the parameters of this weighting procedure,the frequency stabilities of virtual clock ensembles are significantly improved in most cases. 展开更多
关键词 weighting method redundant subspace clock ensemble time scale
下载PDF
Joint multi-user space time block coding and beamforming via convolutional weighting 被引量:1
2
作者 邢志强 Zhou Tingxian Meng Weixiao 《High Technology Letters》 EI CAS 2006年第2期119-123,共5页
A convolutional weighting (CW) scheme applied to a half-wavelength spacing array was proposed for multi-user system to joint STBC (space time block ceding) and beam forming (BF). The transmitting beam is equival... A convolutional weighting (CW) scheme applied to a half-wavelength spacing array was proposed for multi-user system to joint STBC (space time block ceding) and beam forming (BF). The transmitting beam is equivalent to the product of two sub-beams. One is used to realize interference suppression, while the other is employed to form a couple of uncorrelated channels from base station (BS) to the desited user (to meet the requirement of STBC) and to maximize SINR (signal-to-interference-plus noise ratio) at the desired receiver. As an optimum combination of STBC and beam forming, the proposed scheme can achieve both full diversity order of STBC and array gain of BF. Meanwhile, it can also effec- tively restrain multi-user interference by nulling. Simulation results show that the proposed scheme can significantly improve the BER (Bit Error Rate) performance and enhance system capacity as compared with the conventional eigen-beamforming (EBF) technique applied to a half-wavelength spacing array. 展开更多
关键词 space time block ceding beam forming convolutional weighting multi-user interference
下载PDF
A Simple Additive Weighting Method for Time-SeriesMultiindices Decision Making and Its Applications
3
作者 Wang Yingming(Department of Automation, Xiamen University, 361005, P. R. China)(Received January 16, 1998) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1999年第1期4-10,共7页
This paper takes the evaluation of overall economic benefit by an example and proposes a simple additive weighting method for time-series multiindices decision making. The method can automatically determine the weight... This paper takes the evaluation of overall economic benefit by an example and proposes a simple additive weighting method for time-series multiindices decision making. The method can automatically determine the weight coefficients among the multiindices and the years respectively and it also can obtain the objective evaluation results and conclusions. 展开更多
关键词 time-series multiindices DECISION MAKING ECONOMIC BENEFIT evaluation SIMPLE ADDITIVE weighting method.
下载PDF
Differentiation degree combination weighting method for investment decision-making risk assessment in power grid construction projects 被引量:5
4
作者 Yuan Chang Chenmiao Liu +4 位作者 Minghua Liu Wenxia Liu Zongqi Liu Heng Zhang Yan Zheng 《Global Energy Interconnection》 2019年第5期466-478,共13页
Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such proj... Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such projects and effectively prevent investment risks,this paper proposes an investment optimization decision-making method for multiple power grid construction projects under a certain investment scale.Firstly,an in-depth analysis of the characteristics and development requirements of China’s power grid projects was performed.Thereafter,the time sequence and holographic method was adopted to conduct multi-dimensional,multi-perspective risk assessment of different parts of power grid projects,and a holographic risk assessment index system was developed.Moreover,an investment decision model considering the comprehensive risk based on combination weighting was developed according to the output and input of power grid construction projects.A new combination weighting optimization method that takes into account the investment willingness of enterprises was designed to improve the current weighting evaluation methods.Finally,the validity and applicability of the proposed evaluation method were verified by case examples. 展开更多
关键词 Power GRID PROJECTS Risk assessment time SEQUENCE Index system Combination weighting
下载PDF
New HB-weighted time delay estimation algorithm under impulsive noise environment 被引量:2
5
作者 Sun Yongmei Qiu Tianshuang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第6期1102-1108,共7页
The traditional HB-weighted time-delay estimation (TDE) method degenerates under the impulsive noise environment. Two new time-delay estimation methods are proposed based on fractional lower order statistics (FLOS... The traditional HB-weighted time-delay estimation (TDE) method degenerates under the impulsive noise environment. Two new time-delay estimation methods are proposed based on fractional lower order statistics (FLOS) according to the impulsive characteristics of fractional lower order α-stable noises. Theoretic analysis and computer simulations indicate that the proposed covariation based HB weighted (COV-HB) algorithm can suppress impulsive noises in one received signal for 1 ≤α≤ 2, whereas the other proposed fractional lower order eovariancebased HB weighted (FLOC-HB) algorithm has robust performance under arbitrary impulsive noise conditions for the whole range of 0 〈α≤ 2. 展开更多
关键词 HB weighted time delay COVARIATION fractional lower order covariance.
下载PDF
Concise review of relaxations and approximation algorithms for nonidentical parallel-machine scheduling to minimize total weighted completion times 被引量:1
6
作者 Li Kai Yang Shanlin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第4期827-834,共8页
A class of nonidentical parallel machine scheduling problems are considered in which the goal is to minimize the total weighted completion time. Models and relaxations are collected. Most of these problems are NP-hard... A class of nonidentical parallel machine scheduling problems are considered in which the goal is to minimize the total weighted completion time. Models and relaxations are collected. Most of these problems are NP-hard, in the strong sense, or open problems, therefore approximation algorithms are studied. The review reveals that there exist some potential areas worthy of further research. 展开更多
关键词 parallel machine SCHEDULING REVIEW total weighted completion time RELAXATION algorithm
下载PDF
Data point selection for weighted least square fitting of cavity decay time constant 被引量:1
7
作者 何星 晏虎 +2 位作者 董理治 杨平 许冰 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第1期640-646,共7页
For the accurate extraction of cavity decay time, a selection of data points is supplemented to the weighted least square method. We derive the expected precision, accuracy and computation cost of this improved method... For the accurate extraction of cavity decay time, a selection of data points is supplemented to the weighted least square method. We derive the expected precision, accuracy and computation cost of this improved method, and examine these performances by simulation. By comparing this method with the nonlinear least square fitting (NLSF) method and the linear regression of the sum (LRS) method in derivations and simulations, we find that this method can achieve the same or even better precision, comparable accuracy, and lower computation cost. We test this method by experimental decay signals. The results are in agreement with the ones obtained from the nonlinear least square fitting method. 展开更多
关键词 cavity ring-down decay time extraction weighted least square method data point selection
下载PDF
Parametric Transformation of Timed Weighted Marked Graphs:Applications in Optimal Resource Allocation 被引量:1
8
作者 Zhou He Ziyue Ma +1 位作者 Zhiwu Li Alessandro Giua 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第1期179-188,共10页
Timed weighted marked graphs are a subclass of timed Petri nets that have wide applications in the control and performance analysis of flexible manufacturing systems.Due to the existence of multiplicities(i.e.,weights... Timed weighted marked graphs are a subclass of timed Petri nets that have wide applications in the control and performance analysis of flexible manufacturing systems.Due to the existence of multiplicities(i.e.,weights)on edges,the performance analysis and resource optimization of such graphs represent a challenging problem.In this paper,we develop an approach to transform a timed weighted marked graph whose initial marking is not given,into an equivalent parametric timed marked graph where the edges have unitary weights.In order to explore an optimal resource allocation policy for a system,an analytical method is developed for the resource optimization of timed weighted marked graphs by studying an equivalent net.Finally,we apply the proposed method to a flexible manufacturing system and compare the results with a previous heuristic approach.Simulation analysis shows that the developed approach is superior to the heuristic approach. 展开更多
关键词 Discrete event system resource allocation timed Petri net weighted marked graph
下载PDF
Optimizing Polynomial-Time Solutions to a Network Weighted Vertex Cover Game 被引量:1
9
作者 Jie Chen Kaiyi Luo +2 位作者 Changbing Tang Zhao Zhang Xiang Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期512-523,共12页
Weighted vertex cover(WVC)is one of the most important combinatorial optimization problems.In this paper,we provide a new game optimization to achieve efficiency and time of solutions for the WVC problem of weighted n... Weighted vertex cover(WVC)is one of the most important combinatorial optimization problems.In this paper,we provide a new game optimization to achieve efficiency and time of solutions for the WVC problem of weighted networks.We first model the WVC problem as a general game on weighted networks.Under the framework of a game,we newly define several cover states to describe the WVC problem.Moreover,we reveal the relationship among these cover states of the weighted network and the strict Nash equilibriums(SNEs)of the game.Then,we propose a game-based asynchronous algorithm(GAA),which can theoretically guarantee that all cover states of vertices converging in an SNE with polynomial time.Subsequently,we improve the GAA by adding 2-hop and 3-hop adjustment mechanisms,termed the improved game-based asynchronous algorithm(IGAA),in which we prove that it can obtain a better solution to the WVC problem than using a the GAA.Finally,numerical simulations demonstrate that the proposed IGAA can obtain a better approximate solution in promising computation time compared with the existing representative algorithms. 展开更多
关键词 Game-based asynchronous algorithm(GAA) game optimization polynomial time strict Nash equilibrium(SNE) weighted vertex cover(WVC)
下载PDF
Weighted average consensus problem in networks of agents with diverse time-delays 被引量:4
10
作者 Wenhui Liu Feiqi Deng +1 位作者 Jiarong Liang Xuekui Yan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第6期1056-1064,共9页
This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is ... This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is destroyed by diverse time-delays which include communication time-delay and self time-delay. Based on the generalized Nyquist stability criterion and the Gerschgorin disk theorem, some sufficient conditions for the consensus of multi-agent systems are obtained. And we give the expression of the weighted average consensus value for our consensus protocol. Finally, numerical examples are presented to illustrate the theoretical results. 展开更多
关键词 networks of agents distributed control weighted average consensus time-DELAY digraph theory
下载PDF
Fabrication scheduling on a single machine to minimize the weighted sum of product completion time
11
作者 王玉青 孙世杰 《Journal of Shanghai University(English Edition)》 CAS 2007年第2期109-114,共6页
In this paper, a fabrication scheduling problem concerning the production of components at a single manufacturing facility was studied, in which the manufactured components are subsequently assembled into a finite num... In this paper, a fabrication scheduling problem concerning the production of components at a single manufacturing facility was studied, in which the manufactured components are subsequently assembled into a finite number of end products. Each product was assumed to comprise a common component to all jobs and a unique component to itself. Common operations were processed in batches and each batch required a setup time. A product is completed when both its two operations have been processed and are available. The optimality criterion considered was the minimization of weighted flow time. For this scheduling problem, the optimal schedules were described in a weignted shortest processing time first (WSPT) order and two algorithms were constructed corresponding to the batch availability and item availability, respectively. 展开更多
关键词 SCHEDULING PRODUCT weighted flow time weighted shortest processing time first (WSPT) batch processing dynamic programming.
下载PDF
ABSOLUTE CONTINUITIES OF EXIT MEASURES AND TOTAL WEIGHTED OCCUPATION TIME MEASURES FOR SUPER-α-STABLE PROCESSES
12
作者 张静 任艳霞 《Acta Mathematica Scientia》 SCIE CSCD 2006年第2期358-370,共13页
Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measur... Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measure and the total weighted occupation time measure of X in a bounded smooth domain D, respectively. The absolute continuities of Xγ and Yγ are discussed. 展开更多
关键词 Super-α-stable process absolute continuity exit measure total weighted occupation time measure
下载PDF
Lumped Time Distribution Function of Dynamic Equilibrium System and Its Application in Calculating Molecular Weight Distribution of Polymer
13
作者 李洪泊 孙建中 +2 位作者 刘青 翁志学 潘祖仁 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第2期212-217,共6页
The lumped time distribution functions were proposed, which can be used for describing the dynamicsystems with two or more than two states of the end of growing polymer chain during chain addition polymerization.Numer... The lumped time distribution functions were proposed, which can be used for describing the dynamicsystems with two or more than two states of the end of growing polymer chain during chain addition polymerization.Numerical analysis of the lumped time distribution functions was carried out. The method for calculating molecularweight distribution of polymer in the stable free radical polymerization and more general cases was developed basedon the lumped time distribution functions. 展开更多
关键词 lumped time distribution function molecular weight distribution dynamic system
下载PDF
Predictability of Al-Mn Alloy Exposure Time Based on Its As-Cast Weight and Corrosion Rate in Sea Water Environment
14
作者 Chukwuka Nwoye Simeon Neife +2 位作者 Ebere Ameh Awo Nwobasi Ndubuisi Idenyi 《Journal of Minerals and Materials Characterization and Engineering》 2013年第6期307-314,共8页
This paper presents the predictability of aluminium-manganese alloy exposure time based on its as-cast weight and corrosion rate in sea water environment. The validity of the derived model: α = 26.67γ + 0.55β?- 0.2... This paper presents the predictability of aluminium-manganese alloy exposure time based on its as-cast weight and corrosion rate in sea water environment. The validity of the derived model: α = 26.67γ + 0.55β?- 0.29 is rooted on the core expression: 0.0375α = γ + 0.0206β?- 0.0109 where both sides of the expression are correspondingly approximately equal. Statistical analysis of model-predicted and experimentally evaluated exposure time for each value of as-cast weight and alloy corrosion rate considered shows a standard error of 0.0017% & 0.0044% and 0.0140% & 0.0150% respectively. The depths of corrosion penetration (at increasing corrosion rate: 0.0104 - 0.0157 mm/yr) as predicted by derived model and obtained from experiment are 0.7208 × 10-4 & 1.0123 × 10-4 mm and 2.5460 × 10-4 & 1.8240 × 10-4 mm (at decreasing corrosion rate: 0.0157 - 0.0062 mm/yr) respectively. Deviational analysis indicates that the maxi- mum deviation of the model-predicted alloy exposure time from the corresponding experimental value is less than 10%. 展开更多
关键词 Prediction EXPOSURE time AL-MN Alloys SEA Water Alloy AS-CAST weight Corrosion Rate
下载PDF
Real-Time Update of Sequence Placement Logic for High Arch Dams Based on Evidence Weight Discount 被引量:1
15
作者 Tao Guan Denghua Zhong Bingyu Ren 《Transactions of Tianjin University》 EI CAS 2017年第3期267-276,共10页
Sequence placement logic plays a significant role in construction simulation of high arch dams and directly affects the simulation process and results. To establish a sequence logic for dam block placement, the constr... Sequence placement logic plays a significant role in construction simulation of high arch dams and directly affects the simulation process and results. To establish a sequence logic for dam block placement, the construction scheme, real-time construction process, and random factors of the site all need to be considered in detail. There are few studies available currently that take all these factors into consideration. To address this problem, a real-time update of sequence placement logic for high arch dams based on evidence weight discount is proposed in this study. First, the subjective weight of the dam block sequence priority criteria is built using a consistent matrix method based on the construction scheme. Second, using evidence theory, dynamic objective weight of the priority criteria and basic probability assignment is built. Finally, using a weight self-adaptive adjustment method and comprehensive evidence discounting, the placing probabilities of different dam blocks are obtained. A case study indicates that this method can realize real-time update of sequence placement logic. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg. 展开更多
关键词 Arch dams ARCHES DAMS
下载PDF
The Time-Effect Relationship of Central Action in Acupuncture Treatment for Weight Reduction 被引量:2
16
作者 赵玫 刘志诚 +1 位作者 苏静 王友京 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2000年第1期26-29,共1页
Purpose: To study the time-effect relationship of action of acupuncture on the satiety center of ventromedial nucleus of hypothalamus (VMH) in rats with experimental obesity. Methods: Microelectrode recording method o... Purpose: To study the time-effect relationship of action of acupuncture on the satiety center of ventromedial nucleus of hypothalamus (VMH) in rats with experimental obesity. Methods: Microelectrode recording method of nerve cells and stereotaxic technique for brain were adopted with discharge frequency (Hz/s) of nerve impulse in VMH as the index, and the time-effect of acupuncture action in different periods between groups were observed. Results: Electric activity in acupuncture group was higher than that in the obesity model group (P<0.001) and the normal group (P<0.01) respectively, and the curve of acupuncture action within 2 hours showed irregular fluctuation. Conclusion: Acupuncture can increase excitability of the satiety center, with a better long-term effect. 展开更多
关键词 Acupuncture Therapy ELECTROACUPUNCTURE weight Loss ANIMALS ELECTROPHYSIOLOGY Male Obesity Random Allocation RATS Rats Sprague-Dawley time Factors Ventromedial Hypothalamic Nucleus
全文增补中
Improving Badminton Action Recognition Using Spatio-Temporal Analysis and a Weighted Ensemble Learning Model
17
作者 Farida Asriani Azhari Azhari Wahyono Wahyono 《Computers, Materials & Continua》 SCIE EI 2024年第11期3079-3096,共18页
Incredible progress has been made in human action recognition(HAR),significantly impacting computer vision applications in sports analytics.However,identifying dynamic and complex movements in sports like badminton re... Incredible progress has been made in human action recognition(HAR),significantly impacting computer vision applications in sports analytics.However,identifying dynamic and complex movements in sports like badminton remains challenging due to the need for precise recognition accuracy and better management of complex motion patterns.Deep learning techniques like convolutional neural networks(CNNs),long short-term memory(LSTM),and graph convolutional networks(GCNs)improve recognition in large datasets,while the traditional machine learning methods like SVM(support vector machines),RF(random forest),and LR(logistic regression),combined with handcrafted features and ensemble approaches,perform well but struggle with the complexity of fast-paced sports like badminton.We proposed an ensemble learning model combining support vector machines(SVM),logistic regression(LR),random forest(RF),and adaptive boosting(AdaBoost)for badminton action recognition.The data in this study consist of video recordings of badminton stroke techniques,which have been extracted into spatiotemporal data.The three-dimensional distance between each skeleton point and the right hip represents the spatial features.The temporal features are the results of Fast Dynamic Time Warping(FDTW)calculations applied to 15 frames of each video sequence.The weighted ensemble model employs soft voting classifiers from SVM,LR,RF,and AdaBoost to enhance the accuracy of badminton action recognition.The E2 ensemble model,which combines SVM,LR,and AdaBoost,achieves the highest accuracy of 95.38%. 展开更多
关键词 weighted ensemble learning badminton action soft voting classifier joint skeleton fast dynamic time warping SPATIOTEMPORAL
下载PDF
Weighted Pseudo Almost Periodic Solutions for a Class of Hematopoiesis Model with Time-Varying Delay
18
作者 Hui Zhou Liu Yang Wei Jiang 《Analysis in Theory and Applications》 CSCD 2017年第3期197-205,共9页
In this paper, firstly, a notion of a class of generalized weighted pseudo al- most periodic function is introduced, then we investigate some basic and essential properties of the space that consists of these function... In this paper, firstly, a notion of a class of generalized weighted pseudo al- most periodic function is introduced, then we investigate some basic and essential properties of the space that consists of these functions. Finally, we study the exis- tence of weighted pseudo almost periodic solutions to hematopoiesis model with time- varying delay. 展开更多
关键词 weighted pseudo almost periodic hematopoiesis model time-varying delay.
下载PDF
Fragmental Weight-Conservation Combining Scheme for Statistical Signal Transmissions under Fast Time-Varying Channels
19
作者 Xingwei Wang Ting Zhou +3 位作者 Tianheng Xu Songlin Feng Honglin Hu Yanliang Jin 《China Communications》 SCIE CSCD 2020年第1期118-128,共11页
Statistical Signal Transmission(SST)is a technique based on orthogonal frequency-division multiplexing(OFDM)and adopts cyclostationary features,which can transmit extra information without additional bandwidth.However... Statistical Signal Transmission(SST)is a technique based on orthogonal frequency-division multiplexing(OFDM)and adopts cyclostationary features,which can transmit extra information without additional bandwidth.However,the more complicated environment in 5G communication systems,especially the fast time-varying scenarios,will dramatically degrade the performance of the SST.In this paper,we propose a fragmental weight-conservation combining(FWCC)scheme for SST,to overcome its performance degradation under fast time-varying channels.The proposed FWCC scheme consists of three phases:1、incise the received OFDM stream into pieces;2、endue different weights for fine and contaminated pieces,respectively;3、combine cyclic autocorrelation function energies of all the pieces;and 4、compute the final feature and demodulate data of SST.Through these procedures above,the detection accuracy of SST will be theoretically refined under fast time-varying channels.Such an inference is confirmed through numerical results in this paper.It is demonstrated that the BER performance of proposed scheme outperforms that of the original scheme both in ideal channel estimation conditions and in imperfect channel estimation conditions.In addition,we also find the experiential optimal weight distribution strategy for the proposed FWCC scheme,which facilitates practical applications. 展开更多
关键词 Cyclostationary features statistical signal transmission(SST) weight conservation time-varying channels
下载PDF
Weighted Time-Variant Slide Fuzzy Time-Series Models for Short-Term Load Forecasting
20
作者 Xiaojuan Liu Enjian Bai Jian’an Fang 《Journal of Intelligent Learning Systems and Applications》 2012年第4期285-290,共6页
Short-term load forecast plays an important role in the day-to-day operation and scheduling of generating units. Season and temperature are the most important factors that affect the load change, but random factors su... Short-term load forecast plays an important role in the day-to-day operation and scheduling of generating units. Season and temperature are the most important factors that affect the load change, but random factors such as big sport events or popular TV shows can change demand consumption in particular hours, which will lead to sudden load changes. A weighted time-variant slide fuzzy time-series model (WTVS) for short-term load forecasting is proposed to improve forecasting accuracy. The WTVS model is divided into three parts, including the data preprocessing, the trend training and the load forecasting. In the data preprocessing phase, the impact of random factors will be weakened by smoothing the historical data. In the trend training and load forecasting phase, the seasonal factor and the weighted historical data are introduced into the Time-variant Slide Fuzzy Time-series Models (TVS) for short-term load forecasting. The WTVS model is tested on the load of the National Electric Power Company in Jordan. Results show that the proposed WTVS model achieves a significant improvement in load forecasting accuracy as compared to TVS models. 展开更多
关键词 LOAD Forecasting FUZZY time-Series weightED SLIDE
下载PDF
上一页 1 2 116 下一页 到第
使用帮助 返回顶部