期刊文献+
共找到10,000篇文章
< 1 2 250 >
每页显示 20 50 100
Consensus Control With a Constant Gain for Discrete-time Binary-valued Multi-agent Systems Based on a Projected Empirical Measure Method 被引量:5
1
作者 Ting Wang Min Hu Yanlong Zhao 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第4期1052-1059,共8页
This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a pr... This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a projected empirical measure method for a holding time.Based on the estimates,each agent designs the consensus control with a constant gain at some skipping time.The states of the system are updated by the designed control,and the estimation and control design will be repeated.For the estimation,the projected empirical measure method is proposed for the binary-valued observations.The algorithm can ensure the uniform boundedness of the estimates and the mean square error of the estimation is proved to be at the order of the reciprocal of the holding time(the same order as that in the case of accurate outputs).For the consensus control,a constant gain is designed instead of the stochastic approximation based gain in the existing literature for binary-valued observations.And,there is no need to make modification for control since the uniform boundedness of the estimates ensures the uniform boundedness of the agents’states.Finally,the systems updated by the designed control are proved to achieve consensus and the consensus speed is faster than that in the existing literature.Simulations are given to demonstrate the theoretical results. 展开更多
关键词 Binary-valued observations CONSENSUS CONTROL CONSTANT GAIN convergence rate multi-agent systems projected empirical measure method
下载PDF
Risk measurement of international oil and gas projects based on the Value at Risk method 被引量:2
2
作者 Cheng Cheng Zhen Wang +1 位作者 Ming-Ming Liu Xiao-Hang Ren 《Petroleum Science》 SCIE CAS CSCD 2019年第1期199-216,共18页
International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to me... International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to measure the risks of international oil and gas projects. For this purpose, this paper constructs a probabilistic model that is based on the traditional economic evaluation model, and introduces value at risk(VaR) which is a valuable risk measure tool in finance, and applies Va R to measure the risks of royalty contracts, production share contracts and service contracts of an international oil and gas project. Besides, this paper compares the influences of different risk factors on the net present value(NPV) of the project by using the simulation results. The results indicate:(1) risks have great impacts on the project's NPV, therefore, if risks are overlooked, the decision may be wrong.(2) A simulation method is applied to simulate the stochastic distribution of risk factors in the probabilistic model. Therefore, the probability is related to the project's NPV, overcoming the inherent limitation of the traditional economic evaluation method.(3) VaR is a straightforward risk measure tool, and can be applied to evaluate the risks of international oil and gas projects. It is helpful for decision making. 展开更多
关键词 RISK measurement Value at RISK INTERNATIONAL oil and gas projectS FISCAL TERMS - Probabilistic model
下载PDF
Fringe Projection Measurement System in Reverse Engineering 被引量:1
3
作者 林朝辉 何海涛 +3 位作者 郭红卫 陈明仪 石璇 俞涛 《Journal of Shanghai University(English Edition)》 CAS 2005年第2期153-158,共6页
Acquisition of physical data with high precision is a key step in reverse engineering (RE). It is an important stimulative for the progress of reverse engineering with which various digitizing devices are invent ed,... Acquisition of physical data with high precision is a key step in reverse engineering (RE). It is an important stimulative for the progress of reverse engineering with which various digitizing devices are invent ed, developed and made applicable. This paper introduces a three dimensional opt ical measurement method based on digital fringe projection technique in RE to im prove the technique through its application. A practical example is presented an d the result demonstrates the applicability and feasibility of the measurement s ystem as well as the reliability and validity of relevant methods and algorithms . 展开更多
关键词 reverse engineering 3D optical measurement fring e projection multi-aperture overlap-scanning technique (MAOST) surface fitti ng.
下载PDF
Non-contact angle measurement based on parallel multiplex laser feedback interferometry 被引量:4
4
作者 张松 谈宜东 张书练 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期320-324,共5页
We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry (PLFI), which outputs two parallel laser beams and thus their displacement difference reflects the angle ... We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry (PLFI), which outputs two parallel laser beams and thus their displacement difference reflects the angle variation of the target. Due to its ultrahigh sensitivity to the feedback light, PLFI realizes the direct non-contact measurement of non- cooperative targets. Experimental results show that PLFI has an accuracy of 8" within a range of 1400". The yaw of a guide is also measured and the experimental results agree with those of the dual-frequency laser interferometer Agilent 5529A. 展开更多
关键词 laser feedback angle measurement non-cooperative targets
下载PDF
NON-CONTACT MEASUREMENT SYSTEM OF FREEFORM SURFACE AND NURBS RECONSTRUCTION OF MEASUREMENT POINTS 被引量:4
5
作者 Li Jian Wang Wen Chen Zichen Institute of Advanced Manufacturing Engineering, Zhejiang University, Hangzhou 310027, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2002年第4期366-371,共6页
Based on the development of the non-contact measurement system of free-formsurface, NURBS reconstruction of measurement points of freeform surface is effectively realized bymodifying the objective function and recursi... Based on the development of the non-contact measurement system of free-formsurface, NURBS reconstruction of measurement points of freeform surface is effectively realized bymodifying the objective function and recursive procedure and calculating the optimum number ofcontrol points. The reconstruction precision is evaluated through Ja-cobi's transformation method.The feasibility of the measurement system and effectiveness of the reconstruction algorithm aboveare proved by experiment. 展开更多
关键词 freeform surface non-contact measurement NURBS precision evaluation
下载PDF
WEIGHTED ESTIMATES FOR COMMUTATORS OF MULTILINEAR CALDERóN-ZYGMUND OPERATORS WITH NON-DOUBLING MEASURES 被引量:9
6
作者 林海波 孟岩 杨大春 《Acta Mathematica Scientia》 SCIE CSCD 2010年第1期1-18,共18页
Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multil... Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multilinear CalderSn-Zygmund op- erators and RBMO(μ) functions. 展开更多
关键词 non-doubling measure COMMUTATOR multilinear Calderon-Zygmund opera-tor RBMO(μ) weight
下载PDF
Local distinguishability by projective measurement
7
作者 姜伟 任喜军 +2 位作者 周幸祥 周正威 郭光灿 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第8期3243-3246,共4页
This paper proves that a set of orthogonal pure states are indistinguishable by restricted local projective measurement and classical communication if the sum of their Schmidt ranks is larger than the dimension of the... This paper proves that a set of orthogonal pure states are indistinguishable by restricted local projective measurement and classical communication if the sum of their Schmidt ranks is larger than the dimension of their joint Hilbert space. This result is useful in determining the local distinguishability of quantum states and is stronger in some respects than that of Hayashi et al [Phys. Rev. Lett. 96, 040501]. In addition, it presents a new method to determine the local distinguishability of orthogonal states by projecting measurement operators into their subspaces. 展开更多
关键词 local distinguishability projective measurement Schmidt rank
下载PDF
BOUNDEDNESS OF FRACTIONAL INTEGRALS IN HARDY SPACES WITH NON-DOUBLING MEASURE—In Memory of Professor Sun Yongsheng 被引量:2
8
作者 Wengu Chen Yixin Lai 《Analysis in Theory and Applications》 2006年第2期195-200,共6页
Let μ be a Borel measure on R^d which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)^n for any cube Q belong to R^d with sides parallel to the coordinate axes and for some fixed ... Let μ be a Borel measure on R^d which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)^n for any cube Q belong to R^d with sides parallel to the coordinate axes and for some fixed n with 0 〈 n ≤ d. The purpose of this paper is to obtain a boundedness property of fractional integrals in Hardy spaces H^1(μ). 展开更多
关键词 fractional integral Hardy space non-doubling measure
下载PDF
Boundedness for Multilinear Commutators of Marcinkiewicz Integral on Morrey-Herz Spaces with Non Doubling Measures
9
作者 Jianglong Wu Qingguo Liu 《Analysis in Theory and Applications》 2013年第1期62-71,共10页
In this paper, the authors establish the boundedness of multilinear commutators generated by a Marcinkiewicz integral operator and a RBMO(μ) function on homogeneous Morrey-Herz spaces with non doubling measures.
关键词 Marcinkiewicz integral COMMUTATOR Morrey-Herz space non doubling measure RBMO function.
下载PDF
Quantum parameter estimation in a spin-boson dephasing quantum system by periodical projective measurements
10
作者 杨乐 戴宏毅 张明 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期242-249,共8页
In this paper,we explore how to estimate the phase damping parameter γ and the tunneling amplitude parameter ?from a spin-boson dephasing quantum model by periodical projective measurements.The preparation of initia... In this paper,we explore how to estimate the phase damping parameter γ and the tunneling amplitude parameter ?from a spin-boson dephasing quantum model by periodical projective measurements.The preparation of initial states is accomplished by performing the period measurements in our scheme.The parameter γ can be always estimated when projective measurement bases are chosen as θ = π/2 and φ = 0.Based on the estimated value of γ and the interval information of ?,we can select another measurement bases(θ = π/4 and φ = π/2) to obtain the estimated value of ?.A coherent control is indispensable to estimate ? if γ is in the interval of ?;whereas the control is not necessary if γ is out of the known interval of ?.We establish the relation between the optimal period time and the parameter γ or ? in terms of Fisher information.Although the optimal measurement period cannot be selected beforehand,the aforementioned relation can be utilized to adjust the measurement period to approach the optimal one. 展开更多
关键词 parameter estimation periodical projective measurement spin-boson model dephasing quantum system
下载PDF
Research on Selecting Measurement for Landscaping Project in Salination Areas of Changzhou City
11
作者 LIUHui-min CHENYa-jun 《Journal of Northeast Agricultural University(English Edition)》 CAS 2004年第2期123-126,共4页
We had investigated about the situation about garden-making of Changzhou City twice where soil was serious saline and alkaline. We had also investigated the natural environment of the city. Based on these cases, we di... We had investigated about the situation about garden-making of Changzhou City twice where soil was serious saline and alkaline. We had also investigated the natural environment of the city. Based on these cases, we discussed the possible measurements about landscaping project under these conditions, so that we can give out the possible project measurements for the same area. 展开更多
关键词 salination Changzhou City landscaping project possible measurements
下载PDF
Von Neumann’s Theory, Projective Measurement, and Quantum Computation
12
作者 Koji Nagata Tadao Nakamura 《Journal of Applied Mathematics and Physics》 2015年第7期874-897,共24页
We discuss the fact that there is a crucial contradiction within Von Neumann’s theory. We derive a proposition concerning a quantum expected value under an assumption of the existence of the orientation of reference ... We discuss the fact that there is a crucial contradiction within Von Neumann’s theory. We derive a proposition concerning a quantum expected value under an assumption of the existence of the orientation of reference frames in N spin-1/2 systems (1 ≤ N to a new constant . It may be said that a new type of the quantum theory early approaches Newton’s theory in the macroscopic scale than the old quantum theory does. We discuss how our solution is used in an implementation of Deutsch’s algorithm. 展开更多
关键词 Von Neumann’s THEORY projectIVE measureMENT and QUANTUM COMPUTATION
下载PDF
Control Measures of Soil Erosion in a Typical Construction Project Area ( Dina 2 Gas Field)
13
作者 Huiming Lv 《Meteorological and Environmental Research》 CAS 2013年第2期53-58,共6页
To treat the relationship between project construction and ecological environment and effectively prevent new soil erosion during the construction, according to the project layout, soil erosion distribution as well as... To treat the relationship between project construction and ecological environment and effectively prevent new soil erosion during the construction, according to the project layout, soil erosion distribution as well as natural and socio-economic conditions, the control measures of newly increased soil erosion along the project were carried out based on site survey and analysis of relevant information. In addition, adhering to the prin- ciple of partition prevention and treatment, some guiding prevention and control measures of the natural zone passed by the project and soil erosion control district were determined, which provided scientific references and technical support for the rational layout of water and soil conservation and ecological restoration measures in Dina 2 gas field. 展开更多
关键词 Typical construction project area Dina 2 gas field Ecological environment Soil erosion Control measures China
下载PDF
Critical Barriers to Traditional Project Progress Measurement: Perspectives of Ghanaian Construction Professionals
14
作者 James Cofie Danku Kofi Agyekum Francis Terkpertey Asare 《Journal of Building Construction and Planning Research》 2020年第2期119-137,共19页
Accurate project progress measurement is critical for effective project management. Besides guarantying smooth work progress, it affords project managers the chance to identify early warning signs for peremptory remed... Accurate project progress measurement is critical for effective project management. Besides guarantying smooth work progress, it affords project managers the chance to identify early warning signs for peremptory remedial actions to keep the project on schedule and to budget. However, pertinent barriers can suppress the realization of the benefits of an accurate assessment of construction progress. This study aims to identify, examine and prioritize the critical barriers militating against accurate project progress measurement in the Ghanaian construction industry. Sixteen barriers identified from the literature were administered in a questionnaire survey to professionals with tier one construction firms and consultants. Sixty experienced construction professionals practising with tier-one construction firms and consultancy services took part in the survey. The relative importance index technique was used to rank the factors and correlation in responses of the two parties tested by the Mann-Whitney <em>U</em> statistics. The most critical barriers perceived by the professionals were 1) Reliance on Supervisor’s Judgement, 2) Generic and Non-Systematic Approach, 3) Variable Quality of Data and 4) Intricate Measurement Reports. Other highly ranked barriers include 5) Lack of Timely Information, 6) Laborious Data Gathering and 7) Quality Integration Constraint. The findings underpin the need to minimize dependence on subjective opinions and mere experiences of supervisors for assessment of project progress in this age of information technology. Incorporation of a level of automation into traditional progress methods will not only reduce human errors introduced into manually collected data but facilitate visualization of progress reports. Contiguous to a clear specification of the method of progress measurement in the contract document, a system that conveniently integrates cost, time and scope of work into progress measurement must be pursued. Addressing these identified critical barriers will consolidate current construction progress management practices. 展开更多
关键词 project Progress measurement Critical Barriers Construction Professionals Traditional Methods Ghana
下载PDF
A NOTE ON PERTURBATION OF NON-SYMMETRIC DIRICHLET FORMS BY SIGNED SMOOTH MEASURES 被引量:3
15
作者 陈传钟 《Acta Mathematica Scientia》 SCIE CSCD 2007年第1期219-224,共6页
This article discusses the perturbation of a non-symmetric Dirichlet form, (ε, D(ε)), by a signed smooth measure u, where u=u1 -u2 with u1 and u2 being smooth measures. It gives a sufficient condition for the pe... This article discusses the perturbation of a non-symmetric Dirichlet form, (ε, D(ε)), by a signed smooth measure u, where u=u1 -u2 with u1 and u2 being smooth measures. It gives a sufficient condition for the perturbed form (ε^u ,D(ε^u)) (for some a0 ≥ 0) to be a coercive closed form. 展开更多
关键词 non-symmetric Dirichlet form signed smooth measure perturbation of Dirichlet form generalized Feynman-Kac semigroup
下载PDF
A CHARACTERIZATION OF SCHECHTER'S ESSENTIAL SPECTRUM BY MEAN OF MEASURE OF NON-STRICT-SINGULARITY AND APPLICATION TO MATRIX OPERATOR 被引量:1
16
作者 Nedra Moalla 《Acta Mathematica Scientia》 SCIE CSCD 2012年第6期2329-2340,共12页
In this paper we use the notion of measure of non-strict-singularity to give some results on Fredholm operators and we establish a fine description of the Schechter essential spectrum of a closed densely defined linea... In this paper we use the notion of measure of non-strict-singularity to give some results on Fredholm operators and we establish a fine description of the Schechter essential spectrum of a closed densely defined linear operator. 展开更多
关键词 measure of non-strict-singularity Fredholm operator Schechter essentialspectrum matrix operator
下载PDF
Probabilistic Teleportation of an Arbitrary Unknown Two-Qubit State via Positive Operator-Valued Measure and Two Non-maximally Entangled States 被引量:1
17
作者 WANG Zhang-Yin WANG Dong LIU Jun SHI Shou-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5X期859-862,共4页
关键词 正算子估值测量 量子输运 非最大纠缠态 量子信道
下载PDF
Research On Construction Traffic Safety Measures Based On FAHP Model In Hydropower Project
18
作者 Xiao-yan YANG Xin-sheng XIE +2 位作者 Ya-ping NIU Xiao-long ZHU Chang-qi DENG 《Open Journal of Applied Sciences》 2012年第4期91-95,共5页
With the rapid expansion of hydropower projects, Construction safety problem has become one of the bottlenecks for the development of hydropower industry. Combined with the construction of the diversion channel projec... With the rapid expansion of hydropower projects, Construction safety problem has become one of the bottlenecks for the development of hydropower industry. Combined with the construction of the diversion channel project of Guan Yinyan hydropower station, from the point of view of construction traffic safety, based on the result of the FAHP model, factors which influence the construction safety of the diversion channel project of Guan Yinyan hydropower station have been found, relative measures focuses on the approach to eliminate hazards and guarantee construction safety have been elaborated. 展开更多
关键词 CONSTRUCTION SAFETY measures FAHP model SAFETY evaluation Guan Yinyan HYDROPOWER STATION DIVERSION channel project
下载PDF
Application of 3D Projection Profilometry in the High Speed Impaction Surface Deformation Measurement Research
19
作者 Eryi Hu 《Journal of Signal and Information Processing》 2020年第4期103-115,共13页
In order to study the strength of the composite material plate problems, need to adopt a nondestructive testing method to obtain the specimen surface under the effect of high-speed impact regularity of shape. The proj... In order to study the strength of the composite material plate problems, need to adopt a nondestructive testing method to obtain the specimen surface under the effect of high-speed impact regularity of shape. The projection profilometry was used to measure the surface profile or the full field deformation. Furtherly, by using the Fourier transform algorithm, there is only one frame of captured image</span><span style="font-family:Verdana;"> which</span><span style="font-family:Verdana;"> is needed in the measurement, so that it can be introduced into the high speed impaction procedure measurement. An experimental system, which was contained with an impact setup and the projection profilometry measurement part, was constructed for the impaction action characteristic research. The metallic impact object can be launched by a gas gun or a spin fan, respectively. The detected object </span><span style="font-family:Verdana;">is</span><span style="font-family:Verdana;"> manufactured by composite materials. In order to increase the surface deformation measurement accuracy, the calibration method and the error was discussed with different calibration specimen. And then, the proposed profilometry measurement method is proved by the gas gun and spin fan projectile test. The surface deformation of the manufactured composite plates and fan case are measured in the impaction procedure. So that the impact action details can be described much more clearly than the traditional video monitoring method. 展开更多
关键词 projection Profilometry Fourier Transform Algorithm Deformation measurement Impaction Monitoring
下载PDF
Non-Contact Blood Pressure Measurement Based on IPPG
20
作者 Jiancheng Zou Shouyu Zhou +1 位作者 Bailin Ge Xin Yang 《Journal of New Media》 2021年第2期41-51,共11页
Blood pressure is an important physiological parameter to reflect human vital signs.In order to achieve the non-contact dynamic blood pressure acquisition based on ordinary optical camera,a theoretical understanding o... Blood pressure is an important physiological parameter to reflect human vital signs.In order to achieve the non-contact dynamic blood pressure acquisition based on ordinary optical camera,a theoretical understanding of the functional relationship between blood pressure and pulse wave signal conduction time.And through imaging photoelectric plethysmography(IPPG),pulse wave signal conduction time of forehead and hand was obtained with ordinary optical camera.First,the pulse wave conduction time was obtained by recording the video with an ordinary optical camera.Second,real-time blood pressure values were collected.Finally,based on the relationship between blood pressure and pulse wave conduction time,a non-contact blood pressure measurement prediction model was obtained through neural network fitting.So that non-contact blood pressure measurement with optical camera could be completed.The method in this paper has several advantages,such as low requirements on measuring equipment,low cost,and simple operation.It can let people get rid of the discomfort caused by measuring equipment such as cuff and can measure blood pressure at any time.The predicted blood pressure results were compared with an Omron wrist electronic sphygmomanometer.The calculated error of systolic blood pressure is-9.28%~3.16%,and the error of diastolic blood pressure is-9.84~4.35%. 展开更多
关键词 non contact blood pressure measurement imaging photoelectric plethysmography(IPPG) pulse wave conduction time
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部