• 제목/요약/키워드: inconsistency

검색결과 670건 처리시간 0.024초

Structural Dynamic Modification of Fixture by Antiresonance Frequency Analysis in Environmental Vibration Test Control (환경진동시험 제어에서 반공진 진동수해석에 의한 치구의 구조변경설계)

  • 김준엽;정의봉
    • Journal of KSNVE
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    • 제5권4호
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    • pp.555-563
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    • 1995
  • This paper proposes the method of antiresonance frequency analysis of multi-input multi-output system. The structural dynamic modification techniques by antiresonance frequency analysis are also applied to reduce the undertest at specimen attachment points on the fixture in environmental vibration test, which is resulted from the inconsistency of antiresonance frequencies at any specified points. Several computer simulations show that the proposed method can remove the undertest problem which is not removed in conventional vibration test control. And the effectiveness of the method is verified with the impact hammer excitation of aluminium fixture model.

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A Study on the Evaluation Model of Strategic Information Systems Planning (정보시스템 전략계획 평가모형에 관한 연구)

  • 김동태;문용은;이재범
    • Korean Management Science Review
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    • 제15권1호
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    • pp.149-178
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    • 1998
  • Strategic Information Systems Planning(SISP) has gained considerable interest among researchers and practitioners in recent years Which has instigated various related research. Neverthless, only 24 percent of the projects recommended as a result of SISP are ultimately performed. This statistics raise the questions for the need of SISP. This study provides the framework that may enable SISP to be more effectively utilized by studying factors for consideration from the review of pertinent literature. These factors will then be validated by case studies of domestic companies and by simultaneously inducing key characteristics and solutions of SISP. The result of the study indicate some inconsistency between literal factors and the case study. The factors added through case study were considered to be actual factors of SISP. This study emphasized the role of the senior manager, the quality of the implementation of the state plan, change management and the capability of the planning team. As a key characteristics of domestic companies considered was the general lack of ability to collect and analyze data. In addition, the domestic companies have little consideration of the organizational contingency factors.

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정보시스템 전략계획 평가에 관한 연구

  • 김동태;문용은;이재범
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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    • pp.245-249
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    • 1996
  • Strategic Information Systems Planning(SISP) has gained considerable interest among researchers and practitioners in recent years which has instigated various related research. Nevertheless, only 24 percent of the projects recommended as a result of SISP are ultimately performed. This statistics raise the questions for the need of SISP. This study provides the framework that may enable SISP to be more effectively utilized by studying factors for consideration from the review of pertinent literature. These factors will then be validated by case studies of domestic companies and by simultaneously inducing key characteristics and solutions of SISP. The result of the study indicates some inconsistency between literal factors and the case study. The factors added through case study were considered to be actual factors of SISP. This study emphasized the role of the senior manager, the quality of the implementation of the state plan and the capability of the planning team. As key characteristics of domestic companies considered were the general lack of ability to collect and analyze data. In addition, the domestic companies have little consideration of the organizational contingency factors.

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Characteristics of Lifted Flames in Nonpremixed Turbulent Confined Jets (제한공간에서 비예혼합 난류제트 화염의 부상특성)

  • Cha, Min-Suk;Chung, Suk-Ho
    • Journal of the Korean Society of Combustion
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    • 제1권1호
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    • pp.41-49
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    • 1996
  • Effects of ambient geometry on the liftoff characteristics are experimentally studied for nonpremixed turbulent jet flames. To clarify the inconsistency of the nozzle diameter effect on the liftoff height, the ambiences of finite and infinite domains are studied. For nonpremixed turbulent jet issuing from a straight nozzle to infinite domain, flame liftoff height increases linearly with nozzle exit mean velocity and is independent of nozzle diameter. With the circular plate installed on the upstream of nozzle exit, flame liftoff height is lower with plate at jet exit than without, but flame liftoff characteristics are similar to the case of infinite domain. For the confined jet having axisymmetric wall boundary, the ratio of the liftoff height and nozzle diameter is proportional to the nozzle exit mean velocity demonstrating the effect of the nozzle diameter on the liftoff height. The liftoff height increases with decreasing outer axisymmetric wall diameter. At blowout conditions, the blowout velocity decreases with decreasing outer axisymmetric wall diameter and liftoff heights at blowout are approximately 50 times of nozzle diameter.

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Bearing-only Localization of GNSS Interference using Iterated Consider Extended Kalman Filter

  • Park, Youngbum;Song, Kiwon
    • Journal of Positioning, Navigation, and Timing
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    • 제9권3호
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    • pp.221-227
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    • 2020
  • In this paper, the Iterated Consider Extended Kalman Filter (ICEKF) is proposed for bearing-only localization of GNSS interference to improve the estimation performance and filter consistency. The ICEKF is an extended version of Consider KF (CKF) for Iterated EKF (IEKF) to consider an effect of bearing measurement bias error to filter covariance. The ICEKF can mitigate the EKF divergence problem which can occur when linearizing the nonlinear bearing measurement by a large initial state error. Also, it can mitigate filter inconsistency problem of EKF and IEKF which can occur when a weakly observable bearing measurement bias error state is not included in filter state vector. The simulation result shows that the localization error of the ICEKF is smaller than the EKF and IEKF, and the Root Mean Square (RMS) estimation error of ICEKF matches the covariance of filter.

Data reconciliation for multicomposition processes (다성분 공정을 위한 데이터 보정)

  • 이무호;한종훈;장근수
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.36-39
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    • 1996
  • In chemical processes, measurement errors reduce the credibility of information and cause inconsistency in material and energy balances. Because multicomposition flows and temperature measurements make material and energy balances nonlinear equations, data reconciliation becomes a nonlinear constrained optimization problem. In multicomposition processes, if we follow general optimization procedure, the number of measurement variables is so large that data reconciliation requires much computation time. We propose the decomposition procedure to reduce the computation time without the decrease of accuracy of data reconciliation. Decomposition procedure finds global variables, that can reduce the nonlinearity of constraints, and divides two sub-optimization problems. Once we optimize the global variables at upper level, we can easily optimize the remain variables at tower level, We can obtain the short computational time and the same accuracy as SQP optimization method.

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Merits and Limitations of Microgenetic Method as a Means of Studying Developmental Change (아동 발달연구에 있어서 미시발생적 방법의 실과 허)

  • Jun, Myong Nam
    • Korean Journal of Child Studies
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    • 제22권1호
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    • pp.97-107
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    • 2001
  • This study argues the nature of the microgenetic method in respect to child development research and explores its merits and limitations. The microgenetic method focuses on observations that span the entire period from the beginning of developmental change to the time it reaches a relatively stable state. This produces a high density of observations relative to the rate of change in the phenomenon. In this way, observed behavior may be used in intensive trial-by-trial analysis. The microgenetic method is superior to other methods in the possibilities for observing developmental changes as they occur, examining various aspects of change, detecting variability in behavior, and flexibility in application regardless of theoretical perspectives. Limitations of this method include reliability problems due to repeated observations, artificiality relative to the natural situation, inconsistency of short-and long-term change, and demands on children's motivation for participation in research.

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Pre-service Teachers' Conceptions of the Nature of Science

  • Lee, Eun-Ah;Choi, Seong-Hee
    • Journal of the Korean earth science society
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    • 제23권2호
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    • pp.140-146
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    • 2002
  • We have studied 73 pre-service science teachers' conceptions about the nature of science (NOS) using 120 true-false test items based on AAAS Benchmarks statements. We have found that participants have inadequate understanding of the NOS, especially in understanding of five categories of conceptions; change and continuity in science, bias in scientific investigations, hypothesis in scientific investigations, things common in science, and science ethics. The result also indicates that there is a difference between primary pre-service teachers and secondary pre-service teachers. From the analysis of consistency, we also found that this inadequate understanding comes from confusion rather than misconception. All the results support that there is a need of intense pre-service teacher education concerning thenature of science.

Design of the Integrated Incomplete Information Processing System based on Rough Set

  • Jeong, Gu-Beom;Chung, Hwan-Mook;Kim, Guk-Boh;Park, Kyung-Ok
    • Journal of the Korean Institute of Intelligent Systems
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    • 제11권5호
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    • pp.441-447
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    • 2001
  • In general, Rough Set theory is used for classification, inference, and decision analysis of incomplete data by using approximation space concepts in information system. Information system can include quantitative attribute values which have interval characteristics, or incomplete data such as multiple or unknown(missing) data. These incomplete data cause tole inconsistency in information system and decrease the classification ability in system using Rough Sets. In this paper, we present various types of incomplete data which may occur in information system and propose INcomplete information Processing System(INiPS) which converts incomplete information system into complete information system in using Rough Sets.

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Consistency preservation techniques for Location Register System in Mobile Networks

  • Kim, Jang-Hwan
    • International Journal of Internet, Broadcasting and Communication
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    • 제12권2호
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    • pp.144-149
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    • 2020
  • A database called Home Location Register(HLR) plays a major role in location management in mobile cellular networks. The objectives of this paper are to identify the problems of the current HLR system through rigorous analysis, to suggest solutions to them. The current HLR backup method is a process of simply writing the changed memory SLD block to disk, which has a problem in maintaining database consistency. Since information change and backup are performed separately by separate processes, there is a risk of information inconsistency when an error restart occurs. To solve this problem, a transaction concept was introduced for subscriber-related operation functions and a recovery method through logging and checkpointing was introduced. The subscriber related functions of tasks terminated normally by the suggested process are recovered with consistency even after system restarts. Performance is also not affected seriously because disk tasks for log occur with only subscriber related functions.