检索结果-南通市图书馆

Development of a Multiple Degree of Freedom Knee Disarticulation Prosthesis with Active Leg Length Variation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Mechanical engineering 2014年第4期4卷 207-221页

作者： Berend Denkena Martin Eckl Dominik Brouwer Leibniz Universität Hannover Institute of Production Engineering and Machine Tools An der Universit&aumlt 2 Hanover Germany

This paper presents a novel design for a knee disarticulation prosthesis. In this design, three hydraulic cylinders form the supporting structure and provide the damping effect at the same time. That way the novel knee joint offers two fundamental advantages compared to the state of the art. First, the combination of a supporting structure and damping element reduces the weight of the prosthesis. Secondly, the use of several cylinders allows the actuation of further degrees of freedom. Additional degrees of freedom can be used to vary the leg length within the gait cycle and hence to optimize the gait behavior.

关键词： Biomechanics Biomedicine Prostheses Knee-Disarticulation

HOW ARE PRODUCT-SERVICE COMBINED OFFERS PROVIDED IN GERMANY AND ITALY?ANALYSIS WITH COMPANY SIZES AND COUNTRIES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems engineering 2008年第3期17卷 367-381页

作者： Tomohiko SAKAO Nicola NAPOLITANO Massimo TRONCI Erik SUNDIN Mattias LINDAHL institute for Product Development and machine Elements Darmstadt University of TechnologyGermany Department of Management and engineering Linkping UniversitySweden Department of Mechanics and Aeronautics University of Rome"La Sapienza"Italy

A new business concept that offers products and services in a different way of traditional product-sales businesses is getting more attention especially in manufacturing industries. This paper investigates how this new business by means of integration of products and services is achieved in Germany and Italy. In addition, it analyzes the differences according to the company sizes. The results include that this type of business is in many cases motivated by their focus on customers and often consists of physical products and their maintenance. The Italian companies, as opposed to the German ones, often design their physical products specifically for this type of offers. From the analysis based on the size difference, small companies are found to achieve specific design for this type of offers while owning physical products. There do not seem to be any established methods or tools developed to support the development of such offers and within such methods/tools there would be room for more adaptation in form of physical product design.

关键词： Product-service combination functional sales integrated product service engineering service management product design maintenance

Guest Editorial:Advanced Materials for HVDC Insulation

在线全文

学校读者我要写书评

暂无评论

High Voltage 2020年第4期5卷 351-352页

作者： Du, Boxue Wang, Qing Tu, Youping Tanaka, Yasuhiro Li, Jin institute of High Voltage School of Electrical and Information Engineering Tianjin University China Materials Science and engineering Department of Materials Science and Engineering Pennsylvania State University United States Department of Electrical engineering North China Electric Power University China Measurement and Electric machine control Laboratory Tokyo City University Japan School of Electrical and Information engineering Tianjin University China

The rapid increase in both voltage level and capability of HVDC power transmission and transformation equipment poses great challenges to both integration and reliability of power *** insulation systems deployed along with these equipments have to withstand the severe electric field distortion,higher temperature rise and greater mechanical stress,*** insulation materials with unique comprehensive performance provide effective solutions to meet new ***,investigating the dielectric properties,determining the failure mechanisms,and exploring novel insulation materials become the core issues in developing more capable insulation systems.

关键词： insulation dielectric power

Lom： Discovering Logic Flaws Within MongoDB-based Web Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2017年第1期14卷 106-118页

作者： Shuo Wen Yuan Xue Jing Xu Li-Ying Yuan Wen-Li Song Hong-Ji Yang Guan-Nan Si institute of machine Intelligence College of Computer and Control Engineering Nankai University Tianjin 300350 China Department of Electrical engineering and Computer Science Vanderbilt University Nashville Tennessee 37212 USA Centre for Creative Computing Bath Spa University Bath BA2 9BN UK School of Information Science and Electrical engineering Shandong Jiaotong University Ji'nan 250357 China

Logic flaws within web applications will allow malicious operations to be triggered towards back-end database. Existing approaches to identifying logic flaws of database accesses are strongly tied to structured query language （SQL） statement construction and cannot be applied to the new generation of web applications that use not only structured query language （NoSQL） databases as the storage tier. In this paper, we present Lom, a black-box approach for discovering many categories of logic flaws within MongoDB- based web applications. Our approach introduces a MongoDB operation model to support new features of MongoDB and models the application logic as a mealy finite state machine. During the testing phase, test inputs which emulate state violation attacks are constructed for identifying logic flaws at each application state. We apply Lom to several MongoDB-based web applications and demonstrate its effectiveness.

关键词： Logic flaw web application security not only structured query language (NoSQL) database black-box MougoDB.

Effect of the Welding Parameters on the Structural and Mechanical Properties of Aluminium and Copper Sheet Joints by Electromagnetic Pulse Welding

在线全文

学校读者我要写书评

暂无评论

World Journal of engineering and Technology 2016年第4期4卷 538-561页

作者： Irene Kwee Verena Psyk Koen Faes Belgian Welding institute Zwijnaarde Belgium Fraunhofer institute for machine tools and Forming Technology Fraunhofer Institute Chemnitz Germany

Aluminium-copper hybrid parts, as a substitution to copper parts, result in weight and cost reduction, and are relevant in applications related to the electronic, heating and cooling sector. However, aluminium to copper joined by thermal welding processes presents challenges in terms of achieving good joint quality. This is attributed to their dissimilar mechanical and thermal properties which result in large stress gradients during heating. This study investigated joining of aluminium to copper sheets by electromagnetic pulse welding, which is a solid-state process that uses electromagnetic forces for joining of dissimilar materials. Hybrid sheet welds were obtained for all parameters conditions, selected according to a Taguchi L18 design. The structural and mechanical characteristics were examined and related to the welding parameters by means of a Pareto analysis and response graphs. The welded zone started with a wavy interface with interfacial layers and defects and evolved to a flat interface without interfacial layers. The maximum transferable force depended on the minimum specimen thickness and the strength of the hybrid sheet weld. In case of aluminium sheet thickness reduction, the maximum transferable force was linearly correlated with the aluminium sheet thickness. High quality joints were obtained for no aluminium sheet thickness reduction and for a sheet weld strength which was at least as high as that of the base material. The most effective way to increase the transferable force was to lower the initial gap and to increase the free length, which resulted in no aluminium sheet thickness reduction. Alternatively, the use of a rounded spacer decreased the effect of the aluminium sheet thickness on the transferable force. An increase in weld width was achieved for an increase in capacitor charging energy and gap, whereas an increase in weld length was obtained for a decrease in gap. An increase in weld width did not necessarily result in an increase in t

关键词： Electromagnetic Pulse Sheet Welding Aluminum-to-Copper Welds Dissimilar Metal Welds Transferable Force Interfacial Morphology

Scheduling a three-machine no-wait flowshop with separated setup time

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Harbin institute of Technology(New Series) 2006年第2期13卷 206-210页

作者：常俊林邵惠鹤 Dept. of Automation Shanghai Jiaotong University Shanghai 200030 ChinaDept. of Control Science and Engineering Harbin Institute of Technology Harbin 150001 China Dept. of control Science and engineering Harbin Institute of Technology Harbin 150001 China

In many practical flowshop production environments, there is no intermediate storage space available to keep partially completed jobs between any two machines. The workflow has to be continuous, implying that the no-wait conditions must be abided, which is typical in steel and plastic production. We discuss the three-machine no-wait flowshop scheduling problem where the setup times are considered as separated from processing times and sequence independent. The scheduling goal is to minimize the total flowtime. An optimal property and two heuristic algorithms for this problem are proposed. Evaluated over a large number of problems, the proposed heuristics are found that they can yield good solutions effectively with low computational complexity, and have more obvious advantage for the large size problem compared with the existing one.

关键词： three-machine flowshop setup time no-wait total flow time

Network Protocol Recognition Based on Convolutional Neural Network

在线全文

学校读者我要写书评

暂无评论

China Communications 2020年第4期17卷 125-139页

作者： Wenbo Feng Zheng Hong Lifa Wu Menglin Fu Yihao Li Peihong Lin institute of Command and control engineering Army Engineering University of PLANanjing210007China School of Computer Science and Technology Nanjing University of Posts and TelecommunicationsNanjing210023China

How to correctly acquire the appropriate features is a primary problem in network protocol recognition *** to avoid the trouble of artificially extracting features in traditional methods and improve recognition accuracy,a network protocol recognition method based on Convolutional Neural Network(CNN)is *** method utilizes deep learning technique,and it processes network flows ***,normalization is performed on the intercepted network flows and they are mapped into two-dimensional matrix which will be used as the input of ***,an improved classification model named Ptr CNN is built,which can automatically extract the appropriate features of network ***,the classification model is trained to recognize the network *** proposed approach is compared with several machine learning *** results show that the tailored CNN can not only improve protocol recognition accuracy but also ensure the fast convergence of classification model and reduce the classification time.

关键词： convolutional neural network protocol recognition network flow classification model

Application of Kernel GDA to Performance Monitoring and Fault Diagnosis for Rotating machinery

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2010年第5期27卷 709-714页

作者：马思乐张曦邵惠鹤 School of control Science and engineering Shandong University Guangdong Electric Power Research institute School of Electronic Information and Electrical EngineeringShanghai Jiaotong University

Faults in rotating machine are difficult to detect and identify,especially when the system is complex and *** order to solve this problem,a novel performance monitoring and fault diagnosis method based on kernel generalized discriminant analysis(kernel GDA,KGDA)was *** KGDA,the data were mapped from the original space to the high-dimensional feature *** the statistic distance between normal data and test data was constructed to detect whether a fault was *** a fault had occurred,similar analysis was used to identify the type of *** effectiveness of the proposed method was evaluated by simulation results of vibration signal fault dataset in the rotating machinery,which was scalable to different rotating machinery.

关键词： kernel generalized discriminant analysis(KGDA) performance monitoring fault diagnosis rotating machinery

Indirect Adaptive Robust Trajectory Tracking control of Hard Rock TBM with Load Variation of Tunneling Face

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2019年第2期32卷 168-179页

作者： Chengjun Shao Jianfeng Liao Zhitao Liu Hongye Su State Key Laboratory of Industrial control Technology Institute of Cyber-Systems and Control Zhejiang University State Key Laboratory of Fluid Power Transmission and control Zhejiang University

Posture adjustment of open-type hard rock tunnel boring machine(TBM) can be achieved by properly adjusting the hydraulic pressure of gripper cylinder and torque cylinders. However, the time-varying inhomogeneous load acting on tunneling face of TBM and complex stratum working condition can cause the trajectory deviation. In this paper,the position and posture rectification kinematics and dynamics models of TBM have been established in order to track the trajectory. Moreover, there are uncertain parameters and uncertain loads from complex working conditions in the dynamic model. An indirect adaptive robust control strategy is applied to achieve precise position and posture trajectory tracking control. Simulation results show when the position deviation only occurs in Y-axis and the current orientation is parallel with the designed axis, the deviation can be corrected by controlling the pressure of gripper cylinder and the actual trajectory meets the designed axis when TBM is pushed forward 0.14 m in X-axis. If the deviation only occurs in Z-axis, then the deviation can be corrected by controlling torque cylinders. If the position deviation occurs both in Y-axis and Z-axis at the same time, the pressure of gripper cylinder and torque cylinders should be controlled at the same time to rectify the deviation. Simulation results are shown to illustrate the e ectiveness and robustness of the proposed controller. This research proposes an indirect adaptive robust controller that can track the planned tracking trajectory smoothly and rapidly.

关键词： Open type hard rock TBM Inhomogeneous load Position and posture rectification Indirect adaptive robust control