• Title/Summary/Keyword: imperfect

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Economic Decision of Specification Limits for a Ham Production Process - An Industrial Case Study -

  • Cha, Young-Joon;Hong, Yeon-Woong;Lee, Jae-Man
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.4
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    • pp.943-949
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    • 2005
  • An economic design of specification limits for production process of ham is considered for a given process mean in a complete inspection plan. Each ham is inspected, and if it meets the specification, it is accepted. The ham less than the lower specification limit are changed another products or at a discounted price, and those greater than the upper specification limit are reworked. A profit model is developed which involves selling price, production cost, rework cost and the cost which is incurred by imperfect quality. Methods for finding the optimal specification limits are derived for the case of piecewise linear loss function with an industrial case study.

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Robust Predictive Control of Robot Manipulators with Uncertainties (불확실 로봇 매니퓰레이터의 견실 예측 제어기 설계)

  • 김정관;한명철
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.1
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    • pp.10-14
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    • 2004
  • We present a predictive control algorithm combined with the robust robot control that is constructed on the Lyapunov min-max approach. Since the control design of a real manipulator system may often be made on the basis of the imperfect knowledge about the model, it is an important trend to design a robust control law that guarantees the desired properties of the manipulator under uncertain elements. In the preceding robust control work, we need to tune several control parameters in the admissible set where the desired stability can be achieved. By introducing an optimal predictive control technique in robust control we can find out much more deterministic controller for both the stability and the performance of manipulators. A new class of robust control combined with an optimal predictive control is constructed. We apply it to a simple type of 2-link robot manipulator and show that a desired performance can be achieved through the computer simulation.

Study of applicable security tunneling technique for military wireless network (군 무선네트워크 환경에서 적용 가능한 보안 터널링 기법 연구)

  • Kim, Yun-young;Namkung, Seung-Pil
    • Convergence Security Journal
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    • v.15 no.4
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    • pp.107-112
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    • 2015
  • Due to the rapid development of wireless communication technology, foundation system of military communication that is based on the daily use technology has been changed in to wireless system. However, military communication contains clssified information, and it is expected to have increase amount of enemy's there in such a imperfect security system. The next generation of tactical network communication system is expected to adopt All IP based wireless system. This research studies expected threatening factor on the wireless environment, and find the appropriate tunneling techniques.

Development of On-Line Diagnostic Expert System : Heuristics and Influence Diagrams (현장진단 전문가 시스템의 개발 : 휴리스틱과 인플루언스 다이아그램)

  • Kim, Young-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.1
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    • pp.95-113
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    • 1997
  • This paper outlines a framework for a diagnosis of a complex system with uncertain information. Sensor validation ploys a vital role in the ability of the overall system to correctly determine the state of a system monitored by imperfect sensors. Here, emphases are put on the heuristic technology and post-processor for reasoning. Heuristic Sensor Validation (HSV) exploits deeper knowledge about parameter interaction within the plant to cull sensor faults from the data stream. Finally the modified probability distributions and validated data are used as input to the reasoning scheme which is the runtime version of the influence diagram. The output of the influence diagram is a diagnostic mapping from the symptoms or sensor readings to a determination of likely failure modes. Once likely failure modes are identified, a detailed diagnostic knowledge base suggests corrective actions to improve performance. This framework for a diagnostic expert system with sensor validation and reasoning under uncertainty applies in $HEATXPRT^{TM}$ a data-driven on-line expert system for diagnosing heat rate degradation problems in fossil power plants [1].

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Computational impact responses of reinforced concrete slabs

  • Mokhatar, S.N.;Abdullah, R.;Kueh, A.B.H.
    • Computers and Concrete
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    • v.12 no.1
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    • pp.37-51
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    • 2013
  • The responses of reinforced concrete slabs subject to an impact loading near the ultimate load range are explored. The analysis is carried out on a simply supported rectangular reinforced concrete slab using a nonlinear explicit dynamic procedure and considering three material models: Drucker-Prager, modified Drucker-Prager, and concrete damaged plasticity, available in the commercial finite element software, ABAQUS/Explicit. For comparison purposes, the impact force-time response, steel reinforcement failure, and concrete perforation pattern are verified against the existing experimental results. Also, the effectiveness of mesh density and damage wave propagation are studied independently. It is shown that the presently adopted finite element procedure is able to simulate and predict fairly accurate the behavior of reinforced concrete slab under impact load. More detailed investigations are however demanded for the justification of effects coming from an imperfect projectile orientation as well as the load and structural surface conditions, including the impulsive contacted state, which are inevitable in an actual impact environment.

Investigation on vortex-induced vibration of a suspension bridge using section and full aeroelastic wind tunnel tests

  • Sun, Yanguo;Li, Mingshui;Liao, Haili
    • Wind and Structures
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    • v.17 no.6
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    • pp.565-587
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    • 2013
  • Obvious vortex induced vibration (VIV) was observed during section model wind tunnel tests for a single main cable suspension bridge. An optimized section configuration was found for mitigating excessive amplitude of vibration which is much larger than the one prescribed by Chinese code. In order to verify the maximum amplitude of VIV for optimized girder, a full bridge aeroelastic model wind tunnel test was carried out. The differences between section and full aeroelastic model testing results were discussed. The maximum amplitude derived from section model tests was first interpreted into prototype with a linear VIV approach by considering partial or imperfect correlation of vortex-induced aerodynamic force along span based on Scanlan's semi-empirical linear model. A good consistency between section model and full bridge model was found only by considering the correlation of vortex-induced force along span.

Frequency analysis of beams with multiple dampers via exact generalized functions

  • Failla, Giuseppe
    • Coupled systems mechanics
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    • v.5 no.2
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    • pp.157-190
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    • 2016
  • This paper deals with frequency analysis of Euler-Bernoulli beams carrying an arbitrary number of Kelvin-Voigt viscoelastic dampers, subjected to harmonic loads. Multiple external/internal dampers occurring at the same position along the beam axis, modeling external damping devices and internal damping due to damage or imperfect connections, are considered. The challenge is to handle simultaneous discontinuities of the response, in particular bending-moment/rotation discontinuities at the location of external/internal rotational dampers, shear-force/deflection discontinuities at the location of external/internal translational dampers. Following a generalized function approach, the paper will show that exact closed-form expressions of the frequency response under point/polynomial loads can readily be derived, for any number of dampers. Also, the exact dynamic stiffness matrix and load vector of the beam will be built in a closed analytical form, to be used in a standard assemblage procedure for exact frequency response analysis of frames.

Analysis of post-buckling of higher-order graphene oxide reinforced concrete plates with geometrical imperfection

  • Mirjavadi, Seyed Sajad;Forsat, Masoud;Yahya, Yahya Zakariya;Barati, Mohammad Reza;Jayasimha, Anirudh Narasimamurthy;Khan, Imran
    • Advances in concrete construction
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    • v.9 no.4
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    • pp.397-406
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    • 2020
  • The present article deals with post-buckling of geometrically imperfect concrete plates reinforced by graphene oxide powder (GOP) based on general higher order plate model. GOP distributions are considered as uniform and linear models. Utilizing a shear deformable plate model having five field components, it is feasible to verify transverse shear impacts with no inclusion of correction factor. The nonlinear governing equations have been solved via an analytical trend for deriving post-buckling load-deflection relations of the GOP-reinforced plate. Derived findings demonstrate the significance of GOP distributions, geometric imperfectness, foundation factors, material compositions and geometrical factors on post-buckling properties of reinforced concrete plates.

Performance Analysis for Cognitive Vehicular Networks with Imperfect Channel State Information (불완전한 채널 정보가 존재하는 무선 인지 차량 네트워크에서의 성능 분석)

  • Lee, Juhyun;Lee, Jae Hong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.11a
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    • pp.34-35
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    • 2013
  • 기존 연구에서 무선 인지 네트워크의 성능 분석에 관한 연구는 많았지만 무선 인지 네트워크에 차량 통신을 접목시킨 무선 인지 차량 네트워크의 성능 분석에 관한 연구는 많지 않았다. 또한 최근 실질적인 채널환경을 고려하기 위해 불완전한 채널정보를 가잔 시스템에서의 성능 분석에 대한 연구가 많이 진행되고 있는데 무선 인지 차량 네트워크에서의 연구는 아직 진행되지 않았다. 본 논문에서는 불완전한 채널정보가 존재하는 인지 차량 네트워크의 성능 분석을 한다. 본 논문에서는 언더레이 (underlay) 무선 인지 네트워크를 가정하고 차량간 통신이 일어나는 2차 사용자 네트워크의 채널들을 double Rayleigh fading으로 모델링한다. 성능 분석의 지표로 불능 확률을 사용하고 컴퓨터 모의실험을 통해 분석된 불능확률 값이 상관계수가 변화함에 따라 어떠한 변화가 있는지 확인하였다.

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A Research Study on the Actual Conditions of Propensity to Consume and Enterprises of the Knitwears. (니트웨어의 소비자성향 실태 및 업체에 관한 조사연구)

  • 김경희;이순홍
    • Journal of the Korean Society of Costume
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    • v.23
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    • pp.131-150
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    • 1994
  • Knitwears are originated earlier than textiles in human beings life. And then human beings life. And then human beings have been continuously developing as life patterns of human beings are becoming various and society is rapidly changing. Recently , changing life styles of the consumer emphasize the importance of the high quality , individuality , variety , and activity of knitwears. In this study , university women and housewives livings in Seoul have been surveyed in the cause of analyzing of the consumer's actual conditions. And eight brands of th specialized knit enterprises also have been surveyed, though it is imperfect . The purpose of this study lies in giving a help to the rational clothing habits of consumer and presenting some courses for aiming of korean knit industry. I made use of percentage and $x^2$-test for the analysis of the data and analyzed the contents of the question papers.

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