期刊文献+
共找到6,341篇文章
< 1 2 250 >
每页显示 20 50 100
Quantum generative adversarial networks based on a readout error mitigation method with fault tolerant mechanism
1
作者 赵润盛 马鸿洋 +2 位作者 程涛 王爽 范兴奎 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期285-295,共11页
Readout errors caused by measurement noise are a significant source of errors in quantum circuits,which severely affect the output results and are an urgent problem to be solved in noisy-intermediate scale quantum(NIS... Readout errors caused by measurement noise are a significant source of errors in quantum circuits,which severely affect the output results and are an urgent problem to be solved in noisy-intermediate scale quantum(NISQ)computing.In this paper,we use the bit-flip averaging(BFA)method to mitigate frequent readout errors in quantum generative adversarial networks(QGAN)for image generation,which simplifies the response matrix structure by averaging the qubits for each random bit-flip in advance,successfully solving problems with high cost of measurement for traditional error mitigation methods.Our experiments were simulated in Qiskit using the handwritten digit image recognition dataset under the BFA-based method,the Kullback-Leibler(KL)divergence of the generated images converges to 0.04,0.05,and 0.1 for readout error probabilities of p=0.01,p=0.05,and p=0.1,respectively.Additionally,by evaluating the fidelity of the quantum states representing the images,we observe average fidelity values of 0.97,0.96,and 0.95 for the three readout error probabilities,respectively.These results demonstrate the robustness of the model in mitigating readout errors and provide a highly fault tolerant mechanism for image generation models. 展开更多
关键词 readout errors quantum generative adversarial networks bit-flip averaging method fault tolerant mechanisms
下载PDF
An Error Equivalent Model of Revolute Joints with Clearances for Antenna Pointing Mechanisms 被引量:4
2
作者 Quan Liu Sheng-Nan Lu Xi-Lun Ding 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期97-105,共9页
Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consider... Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consideration. In fact, own?ing to errors from machining and assembly, thermal deformation and so forth, practically, axial clearance is inevitable in the joint. In this study, an error equivalent model(EEM) of revolute joints is proposed with considering both radial and axial clearances. Compared to the planar model of revolute joints only considering radial clearance, the journal motion inside the bearing is more abundant and matches the reality better in the EEM. The model is also extended for analyzing the error distribution of a spatial dual?axis("X–Y" type) antenna pointing mechanism of Spot?beam antennas which especially demand a high pointing accuracy. Three case studies are performed which illustrates the internal relation between radial clearance and axial clearance. It is found that when the axial clearance is big enough, the physical journal can freely realize both translational motion and rotational motion. While if the axial clearance is limited, the motion of the physical journal will be restricted. Analysis results indicate that the consideration of both radial and axial clearances in the revolute joint describes the journal motion inside the bearing more precise. To further validate the proposed model, a model of the EEM is designed and fabricated. Some suggestions on the design of revolute joints are also provided. 展开更多
关键词 error modeling Joint clearances Antenna pointing mechanism Radial clearance Axial clearance
下载PDF
CALCULATION OF ELASTIC ERROR OF PLANAR MECHANISM—AN EQUIVALENT METHOD 被引量:2
3
作者 Wang Ailun Zhong Jue Chang Tiegang (College of Mechanical and Electrical Engineering, Central South University of Technology, Changsha 410083, China) 《Journal of Central South University》 SCIE EI CAS 1999年第1期57-59,共3页
Theacuracyproblemwasoneoftheprincipalconcernsinmachinedesignandperformanceconsideration.Itisimportanttounde... Theacuracyproblemwasoneoftheprincipalconcernsinmachinedesignandperformanceconsideration.Itisimportanttounderstandtherelation... 展开更多
关键词 PLANAR mechanism ELASTIC error EQUIVALENT FLEXIBILITY
下载PDF
Error Analysis of Three Degree-of-Freedom Changeable Parallel Measuring Mechanism 被引量:7
4
作者 CHENG Gang GE Shi-rong WANG Yong 《Journal of China University of Mining and Technology》 EI 2007年第1期101-104,共4页
A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Base... A three degree-of-freedom (DOF) planar changeable parallel mechanism is designed by means of control of different drive parameters. This mechanism possesses the characteristics of two kinds of parallel mechanism. Based on its topologic structure, a coordinate system for position analysis is set-up and the forward kinematic solutions are analyzed. It was found that the parallel mechanism is partially decoupled. The relationship between original errors and position-stance error of moving platform is built according to the complete differential-coefficient theory. Then we present a special example with theory values and errors to evaluate the error model, and numerical error solutions are gained. The investigations concentrating on mechanism errors and actuator errors show that the mechanism errors have more influences on the position-stance of the moving platform. It is demonstrated that improving manufacturing and assembly techniques can greatly reduce the moving platform error. The small change in position-stance error in different kinematic positions proves that the error-compensation of software can improve considerably the precision of parallel mechanism. 展开更多
关键词 并行装置 驱动系统 机构学 自动控制
下载PDF
Error analysis and distribution of the driving mechanism for large spherical radio telescope active reflector 被引量:1
5
作者 黄鹏 《High Technology Letters》 EI CAS 2008年第1期1-5,共5页
In order to reduce the cost,3-PRS mechanism is introduced into the application of supporting theactive reflector unit of large radio telescope.The kinematic model of 3-PRS mechanism with rotationaljoint errors is deri... In order to reduce the cost,3-PRS mechanism is introduced into the application of supporting theactive reflector unit of large radio telescope.The kinematic model of 3-PRS mechanism with rotationaljoint errors is derived to solve the error problem in actual engineering application.Then based on the errormodel,inverse and forward kinematics are analyzed.Because the solutions can not be analytically ex-pressed,a numerical method is applied.Afterwards,the parasitic motion errors are analyzed using searchmethod and empirical formulas of the maximum parasitic motion error are put forward.Finally,the toler-ance is distributed using empirical formulas to avoid interference between adjacent reflector units.Theanalyses provide a theoretical basis for the design and installation of large radio telescope active reflector. 展开更多
关键词 无线电 望远镜 3-PRS机制 运动学 误差分析
下载PDF
Fraud Prevention Mechanisms of Malaysian Government-Linked Companies: An Assessment of Existence and Effectiveness 被引量:2
6
作者 Normah Omar Katerina Maria Abu Bakar 《Journal of Modern Accounting and Auditing》 2012年第1期15-31,共17页
关键词 欺诈行为 马来西亚 机制 政府 防范 内部审计 评估 内部控制
下载PDF
Communication error prevention model in industrial organization
7
作者 SHI Gui-rong 《西安科技大学学报》 CAS 北大核心 2016年第5期732-736,共5页
In this study,the communication error generation mechanism was analyzed from the view of human's psychological trait and organizational behavior,based on the basic process of communication,and the individual facto... In this study,the communication error generation mechanism was analyzed from the view of human's psychological trait and organizational behavior,based on the basic process of communication,and the individual factors and organizational factors which cause communication errors were examined.Communication error doesn't just say that there was just a slip in transport of information(misinformation),the behavior which information wasn't conveyed or which couldn't be transported is also included(non-information). To prevent communication error,it's necessary to consider from the individual personal level and the organizational level based on a process of communication. The model to prevent communication error in the industrial organization was tried to propose by this consideration. In recent years,the trouble and accident by nonverbal communication which doesn't depend on language often generate at a work site. It should be considered as future's problem how to prevent such communication error,based on the environment of the work site and the situation. 展开更多
关键词 组织行为学 通信行业 人际交流 通信错误
下载PDF
Designing the Instrument Crank-Coupler Mechanism of Linear Output with Least Transmission Ratio Error
8
作者 裘建新 赵爱华 《Journal of Donghua University(English Edition)》 EI CAS 2004年第4期46-51,共6页
Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction fac... Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction factors all will have synthesis effect on the position accuracy of the mechanical system, the essential factor to guarantee the movement precision remains the kinematic dimensions. Combining the classical theory of mechanical synthesis with the modern error theory and the numerical method, the authors put forward a systematic and complete process and method of computer aided design for the instrument crank-coupler mechanism in which the follower takes the linear displacement approximately within a certain limited domain, with the design result of least transmission ratio error. 展开更多
关键词 曲柄连接机构 线性输出量 传动比 误差 计算机辅助设计
下载PDF
Research on the Error Averaging Effect in A Rolling Guide Pair 被引量:2
9
作者 Yanbing Ni Haiyang Zhou +1 位作者 Cuiyan Shao Jinhe Li 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第4期104-115,共12页
By studying the e ects of geometric precision on kinematic accuracy, an error mapping model has been established, based on the hypothesis that a motion pair and its installation surface are rigid. However, when using ... By studying the e ects of geometric precision on kinematic accuracy, an error mapping model has been established, based on the hypothesis that a motion pair and its installation surface are rigid. However, when using this assumption,there is a significant error induced in high-precision computer numerical control(CNC) machine tools as compared with reality. One of the most important reasons for this error is failing to consider the error averaging e ect of motion pair elements. Therefore, this work examines a high-precision horizontal machining center as its research object, and analyzes the error averaging mechanism of a rolling guide pair under a deformation of the rolling elements. The carriage bearing forces caused by guideway straightness errors are obtained by constructing a geometric error model of a single carriage. The relationship between guideway straightness errors and carriage bearing forces is described by a transfer function in the spatial frequency domain, and its characteristics are analyzed. It quantifies the so-called error averaging e ect of the rolling guide system and, on this basis, a static model for four carriages is established to reflect the error averaging e ect of the rolling guide pair on the position and orientation errors of the motion pair. In addition, it is found that the wavelengths and phase di erences of guideway errors a ect this error averaging mechanism, but the amplitude and preload have little influence thereon. The experiment result shows that the kinematic straightness errors in the x-and y-directions were approximately 1/3 to 1/2 of the guideway straightness errors in the corresponding directions. The results can be used to guide the precision design and assembly of machine tools. 展开更多
关键词 ROLLING guide PAIR error AVERAGING mechanism GUIDEWAY STRAIGHTNESS errors Precision design
下载PDF
A Research on the State-owned Enterprise’s Anti-Corruption Risk Prevention Mechanism and Internal Control Construction
10
作者 Shi JinLong Wang Jingjing 《International Journal of Technology Management》 2016年第12期59-61,共3页
下载PDF
The Scientific Error Analysis在机构误差分析中的应用
11
作者 陈召国 《机电设备》 2004年第1期17-19,共3页
介绍了 ScientificErrorAnalysis软件包的使用,研究了基于 ScientificError Analysis软件包的误差分析方法与一般步骤,以平面四杆机构为例进行了公式推导,给出了计算实例的位置、速度与加速度方差曲线.
关键词 机构分析 误差分析 MAPLE SciemificerrorAnalysis软件包 平面四杆机构 加速度方差曲线 速度 位置
下载PDF
Modeling Method for Assembly Variation Propagation Taking Account of Form Error 被引量:2
12
作者 ZUO Fuchang JIN Xin +1 位作者 ZHANG Zhijing ZHANG Tingyu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第4期641-650,共10页
The propagation of variations, such as fixture errors and datum errors resulting from assembly and machining processes, has been extensively studied. However, only a few studies that focus on form error propagation in... The propagation of variations, such as fixture errors and datum errors resulting from assembly and machining processes, has been extensively studied. However, only a few studies that focus on form error propagation in assembly systems have been implemented. Machining errors, especially form errors, have great impact on assembly accuracy and accuracy stability of precision mechanical systems. With form errors being the research object, a method for calculating mating variation and specifying mating coordinate is proposed to improve the accuracy of the variation propagation model. Taking into account the form error of mating surfaces, the assembly variation propagation of a precision mechanical system is analyzed, and the brief derivation procedure of the variation propagation model is introduced afterwards. The variation propagation model involves a new concept of mating variation specified by the two mating surfaces. An innovative method, the difference surface search based method, is proposed to calculate the mating variation amongst the mating surfaces. The obtained mating variation is then utilized to specify the mating coordinate in the variation propagation model. Moreover, FEM is employed to simulate the contact state of the two mating surfaces to demonstrate effectiveness of the proposed method. Meanwhile, the mating variation and mating coordinate obtained are incorporated into the assembly variation propagation model, which is then verified by a following case study through a comparison between the calculated results and the experimental results. The comparing results indicate that the established model improves the prediction of assembly accuracy. The developed model enables the investigation of various fundamental issues in variation reduction, including variation analysis, process monitoring, accuracy prediction, and accuracy control. 展开更多
关键词 variation propagation precision mechanical system form error difference surface contact point
下载PDF
Influence Analysis of Machining and Installation Errors on the Radial Stiffness of a Non-Pneumatic Mechanical Elastic Wheel 被引量:2
13
作者 You-Qun Zhao Zhen Xiao +2 位作者 Fen Lin Ming-Min Zhu Yao-Ji Deng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第4期92-100,共9页
Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel(ME-Wheel) is not considered in previous studies. To this en... Machining and installation errors are unavoidable in mechanical structures. However, the effect of errors on radial stiffness of the mechanical elastic wheel(ME-Wheel) is not considered in previous studies. To this end, the interval mathematical model and interval finite element model of the ME-Wheel were both established and compared with bench test results. The intercomparison of the influence of the machining and installation errors on the ME-Wheel radial stiffness revealed good consistency among the interval mathematical analysis, interval finite element simulation,and bench test results. Within the interval range of the ME-Wheel machining and installation errors, parametric analysis of the combined elastic rings was performed at different initial radial rigidity values. The results showed that the initial radial stiffness of the flexible tire body significantly influenced the ME-Wheel radial stiffness, and the inverse relationship between the hinge unit length or suspension hub and the radial stiffness was nonlinear. The radial stiffness of the ME-Wheel is predicted by using the interval algorithm for the first time, and the regularity of the radial stiffness between the error and the load on the ME-Wheel is studied, which will lay the foundation for the exact study of the ME-Wheel dynamic characteristics in the future. 展开更多
关键词 Mechanical elastic wheel Stiffness characteristic errorS Interval algorithm Interval finite element
下载PDF
Preventing medication errors in neonatology: Is it a dream? 被引量:3
14
作者 Roberto Antonucci Annalisa Porcella 《World Journal of Clinical Pediatrics》 2014年第3期37-44,共8页
Since 1999, the problem of patient safety has drawn particular attention, becoming a priority in health care. A "medication error"(ME) is any preventable event occurring at any phase of the pharmacotherapy p... Since 1999, the problem of patient safety has drawn particular attention, becoming a priority in health care. A "medication error"(ME) is any preventable event occurring at any phase of the pharmacotherapy process(ordering, transcribing, dispensing, administering, and monitoring) that leads to, or can lead to, harm to the patient. Hence, MEs can involve every professional of the clinical team. MEs range from those with severe consequences to those with little or no impact on the patient. Although a high ME rate has been found in neonatal wards, newborn safety issues have not been adequately studied until now. Healthcare professionals working in neonatal wards are particularly susceptible to committing MEs due to the peculiarities of newborn patients and of the neonatal intensive care unit(NICU) environment. Current neonatal prevention strategies for MEs have been borrowed from adult wards, but many factors such as high costs and organizational barriers have hindered their diffusion. In general, two types of strategies have been proposed: the first strategy consists of identifying human factors that result in errors and redesigning the work in the NICU in order to minimize them; the second one suggests to design and implement effective systems for preventing errors or intercepting them before reaching the patient. In the future, prevention strategies for MEs need to be improved and tailored to the special neonatal population and the NICU environment and, at the same time, every effort will have to be made to support their clinical application. 展开更多
关键词 MEDICATION errorS Drug safety ADVERSE events prevention NEWBORN
下载PDF
Enriched goal-oriented error estimation for fracture problems solved by continuum-based shell extended finite element method 被引量:2
15
作者 林治家 庄茁 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第1期33-48,共16页
An enriched goal-oriented error estimation method with extended degrees of freedom is developed to estimate the error in the continuum-based shell extended finite element method. It leads to high quality local error b... An enriched goal-oriented error estimation method with extended degrees of freedom is developed to estimate the error in the continuum-based shell extended finite element method. It leads to high quality local error bounds in three-dimensional fracture mechanics simulation which involves enrichments to solve the singularity in crack tip. This enriched goal-oriented error estimation gives a chance to evaluate this continuum- based shell extended finite element method simulation. With comparisons of reliability to the stress intensity factor calculation in stretching and bending, the accuracy of the continuum-based shell extended finite element method simulation is evaluated, and the reason of error is discussed. 展开更多
关键词 goal-oriented error estimation finite element analysis fracture mechanics continuum-based shell
下载PDF
OPTIMAL ERROR ESTIMATE IN L~∞(J;L^2(Ω)) NORM OF FEM FOR A MODEL FOR COMPRESSIBLE MISCIBLE DISPLACEMENT IN POROUS MEDIA 被引量:2
16
作者 程爱杰 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1995年第2期222-236,共15页
We’ll study the FEM for a model for compressible miscible displacement in porous media which includes molecular diffusion and mechanical dispersion in one-dimensional space.A class of vertices-edges-elements interpol... We’ll study the FEM for a model for compressible miscible displacement in porous media which includes molecular diffusion and mechanical dispersion in one-dimensional space.A class of vertices-edges-elements interpolation operator ink is introduced.With the help of ink(not elliptic projection),the optimal error estimate in L∞(J;L2(Ω)) norm of FEM is proved. 展开更多
关键词 Molecular diffusion and mechanical dispersion Single-phase displacement Finite element method (FEM) Vertices-edges-elements interpolation Optimal error estimate in L∞(J L2 (Ω)) norm.
下载PDF
Analysis of 3 Serious Medication Errors in Provincial Hospital 被引量:1
17
作者 Ning Hou Hui Tang 《Pharmacology & Pharmacy》 2014年第4期408-412,共5页
Background: Medication errors are a common problem in Chinese hospital, with potentially harmful consequences for patients. The objective of this study was to analyze the cause of typical serious medication errors in ... Background: Medication errors are a common problem in Chinese hospital, with potentially harmful consequences for patients. The objective of this study was to analyze the cause of typical serious medication errors in some first-class provincial hospital to prevent medication error and improve rational use of drug and ensure patients administration security. Medication errors were collected between September 1, 2012 and August 31, 2013. 332 cases’ medication errors were categorized as harmful or not according to NCC MERP’s Index and other indexes such as type of error and causes of error. We focus on analyzing the 3 serious cases (0.9%, n = 3) among the all MEs that may have contributed to or resulted in temporary harm to the patient and required intervention, including the process and the cause and the background of the errors. The case analysis reminds us to pay more attention to prevent medication errors. The preventive medication error’s measures are explored through the analysis of the causes, such as forcing functions and constraints, automation and standardization, double-checking systems, rules and policies, information and more careful working. Conclusion: This analytical study demonstrates that medication error is an objective existent in hospital. It is especially important to ensure patient medication safety for reporting and analyzing medication error in order to explore measures preventing medication error. 展开更多
关键词 MEDICATION error CAUSE ANALYSIS MEDICATION Safety PREVENT Measure
下载PDF
Variation analysis ofprecision mechanical assembly consideringform errors and local deformation
18
作者 张婷玉 金鑫 +1 位作者 张之敬 叶鑫 《Journal of Beijing Institute of Technology》 EI CAS 2014年第3期325-331,共7页
A method to analyze the effect of form errors and local deformation on the assembly accu- racy and its stability in a non-rigid assembly system is proposed. The contact finite element method was used to obtain local d... A method to analyze the effect of form errors and local deformation on the assembly accu- racy and its stability in a non-rigid assembly system is proposed. The contact finite element method was used to obtain local deformation of mating surfaces, which was superposed onto form errors to obtain real mating surface data of assemblies. Then mating variation was obtained by establishing vir- tual contact planes. Finally, an experiment of the assembly of two cylindrical components was car- ried out to verify the validity of the proposed method. By comparing the calculation accuracies of 3D assembly with and without taking into account local deformation, the results showed that the effects of local deformation of mating surfaces on calculation accuracy of mating variation was not neglect- able compared with form errors. 展开更多
关键词 form errors finite element method local deformation precision mechanical system
下载PDF
Prospectively Recording Errors Is Valuable in Reducing Complications
19
作者 Caroline Gunaratnam Adetunji Adeniyi Oremakinde Mark Bernstein 《Health》 2014年第18期2388-2391,共4页
Errors have traditionally been a less commonly discussed topic but are becoming increasingly examined due to a trend towards expanded awareness about the high human and financial cost of errors in medicine. Recording ... Errors have traditionally been a less commonly discussed topic but are becoming increasingly examined due to a trend towards expanded awareness about the high human and financial cost of errors in medicine. Recording and reporting of errors has been a difficult issue in the health sector due to fear of litigation from patients, complaint to governing bodies, and embarrassment from colleagues. In this article we examine the advantages of prospective error recording. The studies on this subject report that the culture of prospective error recording is of high value in improving most parameters of errors and may indeed reduce complications. 展开更多
关键词 PROSPECTIVE Study error RECORDING prevention NEUROSURGERY PROSPECTIVE Value
下载PDF
Identify gaps between local and international measures to avoid administration error on 1-year review in United Christian Hospital, Hong Kong
20
作者 Lap Fung Tsang 《Open Journal of Nursing》 2013年第8期13-20,共8页
Many medication errors could be avoided if administration was more closely linked with structured monitoring. The contributory factors to administration errors occurred in one recent year were reviewed and identified ... Many medication errors could be avoided if administration was more closely linked with structured monitoring. The contributory factors to administration errors occurred in one recent year were reviewed and identified contributory factors to errors as six domains of administration principles according to the report from the Quality and Safety website. The current measures including guidelines, policy, and practices to prevent the administration errors identified in the previous step were searched from the United Christian Hospital (UCH) homepage. Meanwhile, the international measures suggested in literature were identified to address the administration errors identified. 41 cases were identified as medication errors related to administration error events, with total twenty contributory factors identified according to the incident report which identified five contributory factors as common causes. Measures to prevent interruption of medication round and measures to improve individual knowledge and skills, and personal responsebility were suggested to fill the gaps. The medication administration errors should be avoided through both education reinforcing programme and preventive interventions of distraction or interruption to the procedure after comparing the existing measures to the suggested measures from literature. This study was so important to improve the current measures to prevent medication administration errors. 展开更多
关键词 MEDICATION ADMINISTRATION errors Contributory Factors Preventive Measures Gap REVIEW
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部