• 제목/요약/키워드: Uncertainty theory

검색결과 573건 처리시간 0.021초

회전 관절형 로봇 매니플레이터의 강인제어 (Robust Control of a Robot Manipulator with Revolute Joints)

  • 신규현;이수한
    • 한국정밀공학회지
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    • 제20권9호
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    • pp.77-83
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    • 2003
  • In this paper, a robust controller is proposed to control a robot manipulator which is governed by highly nonlinear dynamic equations. The controller is computationally efficient since it does not require the dynamic model or parameter values of a robot manipulator. It, however, requires uncertainty bounds which are derived by using properties of revolute joint robot dynamics. The stability of the robot with the controller is proved by Lyapunov theory. The results of computer simulations show that the robot system is stable, and has excellent trajectory tracking performance.

신뢰성 이론을 이용한 자동창고 설비 선정 전문가 시스템 개발에 관한 연구 (Development of the Expert System for Selection of Equipment for Automated Warehouses Using Reliability Theory)

  • 이영해;정창식
    • Asia pacific journal of information systems
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    • 제8권3호
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    • pp.135-145
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    • 1998
  • There exists popular approach using certainty factor (CF) for the development of effective reasoning mechanism under uncertainty in Expert System, However, there is a problem with CF. The CF values could be resulted in the opposite of given conditional probabilities. In this paper, a method for, reasoning under uncertainty using reliability theory to overcome the problem is proposed. And the proposed method is used in the development of Expert System for the selection of equipment for automated warehouses.

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정부출연연구기관에서의 자금조달환경의 불확실성이 관리통제시스템에 미치는 영향 - PBS 제도 도입을 중심으로 -

  • 이민형
    • 기술혁신연구
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    • 제11권1호
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    • pp.177-193
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    • 2003
  • This paper examines empirically if the increase of funding uncertainty in government supported R&D institutes(GSRIs) in Korean cause managers to use more effective management control practices. Recently government introduced a new government R&D budget management system, based on competition, named PBS(Project Base System). Government requires GSRIs to be self-supporting and compete for funding from government. The introduction of new budget management system named PBS, has resulted in the increase of funding uncertainty in GSRIs. According to institutional theory, government organizations gain legitimacy by conforming to external expectations regarding management control practices, In contrast, contingency theory proposes that management control practices are driven by the fit between the technical features of the environment and the management control practices. The contingency literature provides that one external factor expected to motivate government managers to use more efficient control practices is the presence of competition and funding uncertainty. This paper use both theoretical perspective to develop hypotheses and examine the influence of funding environment on management control practices. Results show that the more institutionalized environment, the more managers in GSRIs rely on bureaucratic mode of control for conforming to external requirements, and the greater the funding uncertainty, the more managers use results and personal modes of control to improve research team performance.

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밀장전 발파압력의 확률론적 예측 (Probabilistic Estimation of Fully Coupled Blasting Pressure)

  • 박봉기;이인모;김동현;이상돈
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.391-398
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    • 2004
  • The propagation mechanism of a detonation pressure with fully coupled charge is clarified and the blasting pressure propagated in rock mass is derived from the application of shock wave theory. Probabilistic distribution is obtained by using explosion tests on emulsion and rock property tests on granite in Seoul and then the probabilistic distribution of the blasting pressure is derived from their properties. The probabilistic distributions of explosive properties and rock properties show a normal distribution so that the blasting pressure propagated in rock can be also regarded as a normal distribution. Parametric analysis was performed to pinpoint the most influential parameter that affects the blasting pressure and it was found that the detonation velocity is the most sensitive parameter. Moreover, uncertainty analysis was performed to figure out the effect of each parameter uncertainty on the uncertainty of blasting pressure. Its result showed that uncertainty of natural rock properties constitutes the main portion of blasting pressure uncertainty rather than that of explosive properties.

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다국적기업의 R&D 자회사 전략 : 기술기업 연구개발 특허성과를 중심으로 (MNCs R&D Subsidiary Strategy : Focusing on Technology Firm Patent Performance)

  • 김지연
    • Journal of Information Technology Applications and Management
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    • 제24권4호
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    • pp.13-24
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    • 2017
  • This study aims to analyze which subsidiary configuration strategy is more effective under uncertainty especially technology base multinational corporations (henceforth MNCs). In previous studies real option theory scholars argue that high breadth subsidiary configuration is most effective strategy because that provides flexibility to MNCs global network. In this study I want unveil more various types of uncertainty such as technology and learning uncertainty which are more important for technology base firm and further more examine the effect of MNCs subsidiary configuration on firm R&D performance each uncertainty case. Empirical study is performed by negative binominal model based on Japanese 108 multinational corporations. The result shows that under technology uncertainty, high breadth subsidiary configuration is better for firm R&D performance but under learning uncertainty high depth subsidiary configuration is better. Thus, the effects of MNCs subsidiary configuration on firm value can differ by types of uncertainty.

측정이론에 관한 중학교 1학년 학생의 선개념 조사 (Investigation on the Seventh Grade Student's Preconceptions about Measurement Theory)

  • 서정아
    • 한국과학교육학회지
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    • 제22권3호
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    • pp.455-465
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    • 2002
  • 본 연구는 중학교 1학년 학생 30명을 대상으로 반복 측정, 대푯값 선정, 오차, 측정의 불확실성에 대한 신개념을 관찰 및 면담을 통하여 조사하였다. 조사 결과 50%의 학생들이 단 두 번만 측정하였고, 5번 이상 측정한 학생은 없었다. 반복 측정 후에 77%의 학생들은 자신의 느낌에 의거하여 측정값 중에서 대푯값을 선택하였고, 13%의 학생만 평균값을 계산하여 대푯값으로 정하였다. 60%의 학생은 측정 오차의 원인을 환경이나 측정 도구보다는 자신의 과실 때문이라고 하였다. 또한 대부분의 학생들은 다른 사람들에 의한 측정값이나 사간차를 둔 측정값이 달라지는 원인을 인간 때문이라고 생각하였다. 측정의 불확실성에 대하여 묻는 질문에 대하여 완전히 정확한 측정이 가능하다고 응답한 학생이 40%, 측정은 불확실하다고 응답한 학생이 33% 이었다. 학생들은 이에 대한 판단 근거로 주로 인간의 한계를 생각하였다. 결론적으로 과반수 이상의 학생들이 반복 측정 및 대푯값 선정에 대하여 이해하지 못하였고 측정 오차의 원인을 자신의 과실로 생각하였다. 또한 대부분의 학생들은 측정 결과가 다르거나, 측정이 불확실한 원인을 인간으로 생각하였다.

대장암 환자를 위한 불확실성 이론 기반 모바일 내비게이션 프로그램의 효과 (Effects of Mobile Navigation Program in Colorectal Cancer Patients based on Uncertainty Theory)

  • 김경진;박완주
    • 대한간호학회지
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    • 제49권3호
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    • pp.274-285
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    • 2019
  • Purpose: This study aimed to examine the effects of a mobile navigation program on uncertainty, resilience, and growth through uncertainty in colorectal cancer patients. Methods: To verify the effectiveness of the mobile navigation program, 61 participants diagnosed with colorectal cancer undergoing surgery were selected. A nonequivalent control group nonsynchronized design was used to evaluate the program. Uncertainty was measured using the Korean version of the Uncertainty in Illness Scale, resilience was measured using the Korean version of the Connor-Davidson Resilience Scale, and growth through uncertainty was measured using the Growth through Uncertainty Scale. Results: Compared with the control group, patients in the mobile navigation program group showed significant differences in scores for uncertainty (F=7.22, p=.009) and resilience (F=4.31, p=.042), but not for growth through uncertainty (F=2.76, p=.102). Conclusion: These results suggest that the mobile navigation program has positive effects on decreasing uncertainty and increasing resilience among colorectal cancer patients. The mobile navigation program could play a significant role in assisting colorectal cancer patients in regard to the continuity and usability of the program.

Fixed Charge Transportation Problem and Its Uncertain Programming Model

  • Sheng, Yuhong;Yao, Kai
    • Industrial Engineering and Management Systems
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    • 제11권2호
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    • pp.183-187
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    • 2012
  • In this paper, we study the fixed charge transportation problem with uncertain variables. The fixed charge transportation problem has two kinds of costs: direct cost and fixed charge. The direct cost is the cost associated with each source-destination pair, and the fixed charge occurs when the transportation activity takes place in the corresponding source-destination pair. The uncertain fixed charge transportation problem is modeled on the basis of uncertainty theory. According to inverse uncertainty distribution, the model can be transformed into a deterministic form. Finally, in order to solve the uncertain fixed charge transportation problem, a numerical example is given to show the application of the model and algorithm.

Comonotonic Uncertain Vector and Its Properties

  • Li, Shengguo;Zhang, Bo;Peng, Jin
    • Industrial Engineering and Management Systems
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    • 제12권1호
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    • pp.16-22
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    • 2013
  • This paper proposes a new concept of comonotonicity of uncertain vector based on the uncertainty theory. In order to understand the comonotonicity of uncertain vector, some equivalent definitions are presented. Following the proposed concept, some basic properties of comonotonic uncertain vector are investigated. In addition, the operational law is given for calculating the uncertainty distributions of monotone functions of comonotonic uncertain variables. With the help of operational law, the comonotonic uncertain vector is applied to the premium pricing problems. At last, some numerical examples are given to illustrate the application.

MCCARD: MONTE CARLO CODE FOR ADVANCED REACTOR DESIGN AND ANALYSIS

  • Shim, Hyung-Jin;Han, Beom-Seok;Jung, Jong-Sung;Park, Ho-Jin;Kim, Chang-Hyo
    • Nuclear Engineering and Technology
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    • 제44권2호
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    • pp.161-176
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    • 2012
  • McCARD is a Monte Carlo (MC) neutron-photon transport simulation code. It has been developed exclusively for the neutronics design of nuclear reactors and fuel systems. It is capable of performing the whole-core neutronics calculations, the reactor fuel burnup analysis, the few group diffusion theory constant generation, sensitivity and uncertainty (S/U) analysis, and uncertainty propagation analysis. It has some special features such as the anterior convergence diagnostics, real variance estimation, neutronics analysis with temperature feedback, $B_1$ theory-augmented few group constants generation, kinetics parameter generation and MC S/U analysis based on the use of adjoint flux. This paper describes the theoretical basis of these features and validation calculations for both neutronics benchmark problems and commercial PWR reactors in operation.