• Title/Summary/Keyword: Mechanisms and Machines

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Linear Electric Motors in Machining Processes

  • Gieras, Jacek F.
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.4
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    • pp.380-389
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    • 2013
  • Application of linear electric motors to automation of manufacturing processes, gantry robots, machining processes, machining centers, additive manufacturing and laser scribing has been discussed. The paper focuses on replacement of ball lead screw mechanisms with linear electric motors, linear motor driven positioning stages, linear motor driven gantries, machining centers, machining of large objects and industrial lasers. The best linear electric motors for application to machining processes are permanent magnet (PM) linear synchronous motors (LSMs), especially those without PMs in the reaction tail, e.g., high thrust density linear (HDL) LSMs and PM flux switching (FS) LSMs.

A study on the insulation detection for electrical machnes by corona pulse technique (Corona pulse 검출에 의한 전력기기절연진단에 대한-고찰)

  • 성영권;정성계;김왕곤
    • 전기의세계
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    • v.16 no.5
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    • pp.15-18
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    • 1967
  • This paper shows the analysis for mechanisms of corona pulse caused by dielectric breakdown, and for the results of observed values on an actual machines with the this corona pulse technique. Although the above results are not directly related with the generation, numbers or wave of the corona pulse, it may possibly be chanced a judgement of dielectric breakdown and one of better synthetic judgement methods for actual electrical machines.

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An Adaptive Virtual Machine Location Selection Mechanism in Distributed Cloud

  • Liu, Shukun;Jia, Weijia
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.12
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    • pp.4776-4798
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    • 2015
  • The location selection of virtual machines in distributed cloud is difficult because of the physical resource distribution, allocation of multi-dimensional resources, and resource unit cost. In this study, we propose a multi-object virtual machine location selection algorithm (MOVMLSA) based on group information, doubly linked list structure and genetic algorithm. On the basis of the collaboration of multi-dimensional resources, a fitness function is designed using fuzzy logic control parameters, which can be used to optimize search space solutions. In the location selection process, an orderly information code based on group and resource information can be generated by adopting the memory mechanism of biological immune systems. This approach, along with the dominant elite strategy, enables the updating of the population. The tournament selection method is used to optimize the operator mechanisms of the single-point crossover and X-point mutation during the population selection. Such a method can be used to obtain an optimal solution for the rapid location selection of virtual machines. Experimental results show that the proposed algorithm is effective in reducing the number of used physical machines and in improving the resource utilization of physical machines. The algorithm improves the utilization degree of multi-dimensional resource synergy and reduces the comprehensive unit cost of resources.

Study of Danger-Theory-Based Intrusion Detection Technology in Virtual Machines of Cloud Computing Environment

  • Zhang, Ruirui;Xiao, Xin
    • Journal of Information Processing Systems
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    • v.14 no.1
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    • pp.239-251
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    • 2018
  • In existing cloud services, information security and privacy concerns have been worried, and have become one of the major factors that hinder the popularization and promotion of cloud computing. As the cloud computing infrastructure, the security of virtual machine systems is very important. This paper presents an immune-inspired intrusion detection model in virtual machines of cloud computing environment, denoted I-VMIDS, to ensure the safety of user-level applications in client virtual machines. The model extracts system call sequences of programs, abstracts them into antigens, fuses environmental information of client virtual machines into danger signals, and implements intrusion detection by immune mechanisms. The model is capable of detecting attacks on processes which are statically tampered, and is able to detect attacks on processes which are dynamically running. Therefore, the model supports high real time. During the detection process, the model introduces information monitoring mechanism to supervise intrusion detection program, which ensures the authenticity of the test data. Experimental results show that the model does not bring much spending to the virtual machine system, and achieves good detection performance. It is feasible to apply I-VMIDS to the cloud computing platform.

A Study on the Friction of Tire Tread Rubber using High-Speed Friction Test Machine (고속 마찰 특성 평가시험기 개발을 통한 타이어 트레드 고무의 마찰에 관한 연구)

  • Lee, Jin Koo;Lee, Dong Ju
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.6
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    • pp.622-628
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    • 2013
  • Due to the development of compounding technology, there is a considerable increase in the number of high performance rubbers in the world. Accordingly, there are rapid growing requests about high performance tires such as UHP tire and Run-flat tire. However, it is extremely difficult to investigate the friction coefficient of tire tread rubbers. An alternative solution must be developed with the reliability of high-speed linear friction test machines. The use of friction test machines can be expected to improve rubber friction researches. In this paper, we propose a new kind of high-speed linear friction test machine. We have designed and manufactured various mechanisms for friction tests. The final goals are to design and manufacture friction test machines that can investigate friction coefficients efficiently and rapidly. The performance of the proposed high-speed linear friction test machine is evaluated experimentally; however additional study should be necessary for safer and more reliable experimentation.

A Study on Performance Improvement of the Motion Drive of a Card Vending Machine (카드자판기 구동부의 성능 향상에 관한 연구)

  • 남명현;강철구
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.4
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    • pp.357-363
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    • 2004
  • Earlier models of card vending machines have generally motion drives with high cost and large size. However, current trend in card vending machines requires low-cost, compact-sized and readily installable motion drives. This paper shows the operational principle of the motion drive of a card vending machine and then presents the performance test results of the motion drive with improved mechanisms proposed in the paper. The results show that the proposed mechanism is valid and improves the card dispensing performance. The proposed model in the paper is accepted and introduced in the actual production line.

APPLICATION OF CONSTRAINT LOGIC PROGRAMMING TO JOB SEQUENCING

  • Ko, Jesuk;Ku, Jaejung
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.617-620
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    • 2000
  • In this paper, we show an application of constraint logic programming to the operation scheduling on machines in a job shop. Constraint logic programming is a new genre of programming technique combining the declarative aspect of logic programming with the efficiency of constraint manipulation and solving mechanisms. Due to the latter feature, combinatorial search problems like scheduling may be resolved efficiently. In this study, the jobs that consist of a set of related operations are supposed to be constrained by precedence and resource availability. We also explore how the constraint solving mechanisms can be defined over a scheduling domain. Thus the scheduling approach presented here has two benefits: the flexibility that can be expected from an artificial intelligence tool by simplifying greatly the problem; and the efficiency that stems from the capability of constraint logic programming to manipulate constraints to prune the search space in an a priori manner.

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Next station selection rules for FMS scheduling against due-date (납기를 고려한 FMS 일정계획에서의 기계선정규칙)

  • 문일경;김태우
    • Korean Management Science Review
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    • v.13 no.2
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    • pp.147-161
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    • 1996
  • Due-date is an important factor in Flexible Manufacturing System scheduling. Even though most of researchers have focused part selection and loading problem using fixed due-date assignment rules, FMSs consist of multi-function machines which facilitate alternative processes. This research investigates interactions of three dispatching mechanisms, three NSS (Next Station Selection) rules and four due-date assignment rules using simulation. Both cost-based and time-based performance measures are considered in this research.

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The a.c. losses in (Bi,Pb)2Sr2Ca2Cu3Ox silver-sheathed superconducting tapes (Bi-2223 고온 초전도 선재의 교류손실에 관한 연구)

  • Kang, Hyoung-Ku;Chu, Yong;Lee, Chan-Joo;Ko, Tae-Kuk;Nah, Wan-Soo
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.822-824
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    • 2000
  • To apply HTS to AC devices, it is necessary that study theoretically and experimentally to analyze the AC losses. It should be investigated the theoretical mechanisms precede the actual experiments. Because the AC losses cause some complicated troubles in AC machines, we can design the machines properly. In this study, firstly we analyze the basic cause of AC losses by investigating the several loss factors, secondly measure the AC losses of HTS by using Magnetization. Technique and this results show that AC losses of HTS is tenuous than those of general materials used in power system. Consequently we can compare the actual results with the theoretical results. And we find that AC losses of HTS are related to the amplitude of external magnetic field and the frequency. Through this study, we find that it is possible to apply the results by Magnetization. Technique to the AC power system, to the design of AC machine, to design of HTS proper to the foretold AC losses.

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Locking in Practice : Performance of a Database System on a Multicore Machine (락의 실제 : 멀티코어 상의 데이터베이스 성능 분석)

  • Han, Hyuck
    • The Journal of the Korea Contents Association
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    • v.14 no.8
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    • pp.22-29
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    • 2014
  • A lock is a general and popular way of serializing accesses to shared data in multiprocessor environments. After the mutual exclusion was first introduced in 1960s, many spinlock algorithms have been proposed and deployed to real systems such as operating systems and (transactional) database systems. In this study, we measure impacts of a lock mechanism on a database system under various CPU configurations using a high-end multicore system. For the evaluation, we use the most up-to-date version of MySQL (version 5.6) with InnoDB engine, which has been substantially re-architected to improve scalability on multicore machines. We changed the original spinlock function of InnoDB to evaluate various spinlock mechanisms on multicore machines.