• 제목/요약/키워드: influence diagram

검색결과 160건 처리시간 0.029초

Predicting the Tritium Release Accident in a Nuclear Fusion Plant (원자핵 융합 발전소의 삼중수소 유출 사고 예측)

  • 양희중
    • Journal of Korean Society for Quality Management
    • /
    • 제26권1호
    • /
    • pp.201-212
    • /
    • 1998
  • A methodology of the safety analysis on the fusion power plant is introduced. It starts with the understanding of the physics and engineering of the plant followed by the assessment of the tritium inventory and flow rate. We a, pp.y the probabilistic risk assessment. An event tree that explains the propagation of the accident is constructed and then it is translated in to an influence diagram, that is accident is constructed and then it is translated in to an influence diagram, that is statistically equivalent so far as the parameter updating is concerned. We follow the Bayesian a, pp.oach where model parameters are treated as random variables. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of time to next severe accident.

  • PDF

최저가 낙찰제의 확대시행이 건설산업과 공공부문에 미치는 영향성 분석 Causal Loop Diagram 이용

  • Park, Kwang-Kuk;Kim, Tae-Min;Kim, Chang-Duk;Yu, Jung-Ho
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 한국건설관리학회 2007년도 정기학술발표대회 논문집
    • /
    • pp.267-272
    • /
    • 2007
  • In the construction industry government is not only an owner but also a consumer. Accordingly it should develop the construction industry and this role is important. Among them, the law of the ordering method is standards of selecting a successful bidder and have powerful influence over the construction industry and owners. Therefore this study said how the lowest bid method, which has taken effect still more, has influence on the construction industry and the public sector with the Causal Loop Diagram. According to analyzing this construction law, we can grasp the point of the strength and weakness of this law also examine a trend of how the present law is changed. While we studied, we tried to adhere to neutrality and form a new opinion about it because the previous studies were opposed to each other. As a result, to improve the relation between the government and private company, which were opposed to each other about arguments for and against the lowest bid method, this study suggest the method of making better the relation. The final goal of it is researching the inefficient factors and improving the weakness of this law.

  • PDF

Experiments for Forming Limit Diagram and Springback Characteristics of AZ31B Magnesium Alloy Sheet at Elevated Temperature (AZ31B 마그네슘 합금판재의 온간 성형한계도 및 스프링백 특성 시험)

  • Choi, C.S.;Lee, H.S.;Kim, H.J.;Lee, K.T.;Kim, H.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 한국소성가공학회 2007년도 춘계학술대회 논문집
    • /
    • pp.289-293
    • /
    • 2007
  • The effect of temperature on the forming limit diagram was investigated for AZ31B magnesium alloy sheet through the limit dome height test in the range from room temperature to $300^{\circ}C$. The formability of AZ31B sheet was improved significantly according to the increasing temperature. Also we studied the springback characteristics through the 2D draw bending test with different blank holding forces at elevated temperatures. Springback quantity was considerably reduced as temperature went up. The blank holding force in the range used, however, had little influence on springback. Experimental results obtained in this study may provide a material database for AZ31B sheet.

  • PDF

Experiments for Forming Limit Diagram and Springback Characteristics of AZ31B Magnesium Alloy Sheet at Elevated Temperature (AZ31B 마그네슘 합금판재의 온간 성형한계도 및 스프링백 특성 시험)

  • Kim, H.Y.;Choi, S.C.;Lee, H.S.;Kim, H.J.;Lee, K.T.
    • Transactions of Materials Processing
    • /
    • 제16권5호통권95호
    • /
    • pp.364-369
    • /
    • 2007
  • The effect of temperature on the forming limit diagram was investigated for AZ31B magnesium alloy sheet through the limit dome height test in the range from room temperature to $300^{\circ}C$. The formability of AZ31B sheet was improved significantly according to the increasing temperature. Also we studied the springback characteristics through the 2D draw bending test with different blank holding forces at elevated temperatures. Springback quantity was considerably reduced as temperature went up. The blank holding force in the range used, however, had little influence on springback. Experimental results obtained in this study may provide a material database for AZ31B sheet.

Ordered Reverse k Nearest Neighbor Search via On-demand Broadcast

  • Li, Li;Li, Guohui;Zhou, Quan;Li, Yanhong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제8권11호
    • /
    • pp.3896-3915
    • /
    • 2014
  • The Reverse k Nearest Neighbor (RkNN) query is valuable for finding objects influenced by a specific object and is widely used in both scientific and commercial systems. However, the influence level of each object is unknown, information that is critical for some applications (e.g. target marketing). In this paper, we propose a new query type, Ordered Reverse k Nearest Neighbor (ORkNN), and make efforts to adapt it in an on-demand scenario. An Order-k Voronoi diagram based approach is used to answer ORkNN queries. In particular, for different values of k, we pre-construct only one Voronoi diagram. Algorithms on both the server and the clients are presented. We also present experimental results that suggest our proposed algorithms may have practical applications.

A Study on the Forming Limit Diagram Tests of Metal Sheets (금속 판재의 성형한계도 시험법에 관한 연구)

  • Jang, Uk-Kyeong;Jang, Yun-Ju;Kim, Hyung-Jong
    • Journal of Industrial Technology
    • /
    • 제30권A호
    • /
    • pp.49-57
    • /
    • 2010
  • A forming limit diagram (FLD) defines the extent to which specific sheet material can be deformed by drawing, stretching or any combination of those two. To determine the forming limit curve (FLC) accurately, it is necessary to perform the tests under well-organized conditions. In this study, the influence of several geometric or process parameters such as the blank shape and dimensions, strain measuring equipments, test termination time, forming speed and lubricants on the FLC is investigated.

  • PDF

Risk-based Decision Model to Estimate the Contingency for Large Construction Projects (리스크 분석에 기초한 대형건설공사의 예비비 산정에 관한 연구)

  • Kim Du-Yon;Han Goo-Soo;Han Seung-Hun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 한국건설관리학회 2003년도 학술대회지
    • /
    • pp.485-490
    • /
    • 2003
  • Nowadays the rapid change in construction environment getting more globalized and complicated has caused lots of unexpected risks from inside and out of the country, so more sophisticated construction management strategies are being strongly needed. This paper suggests a risk management model with which we can estimate the appropriate contingency by quantifying the amount of probable risks immanent in large construction projects, which have a high degree of uncertainty in the anticipation of the total construction cost. To develop the model, the risk factors that make cost variations are elicited based on the real data of the contingencies assigned to the past projects. Furthermore, the influential relationship of risk factors is structured by applying the CRM(Cost Risk Model) which is the synthetic model of Monte Carlo Simulation, Influence Diagram and Decision Tree. The ultimate outcome of this research can by validated by tile case study with a large construction project performed.

  • PDF

Approximations of Optimal Calibration Experimental Designs Using Gaussian Influence Diagrams

  • Kim, Sung-Chul
    • Journal of the Korean Statistical Society
    • /
    • 제22권2호
    • /
    • pp.219-234
    • /
    • 1993
  • A measuring instrument must be calibrated for accurate inferences of an unknown quantity. Bayesian calibration designs with respect to squared error loss based on a linear model are discussed in Kim and Barlow (1992). In this paper, we consider approximations of the optimal calibration designs using the idea of Gaussian inflence diagrams. The approximation is evaluated by means of numerical calculations, where it is compared with the exact values from the numerical integration.

  • PDF

A Heuristic Algorithm to Update Probabilities in Influence Diagrams (영향도에서의 확률개선을 위한 휴리스틱 알고리즘)

  • Bae, Ki Woong
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • 제18권36호
    • /
    • pp.83-91
    • /
    • 1995
  • The objective of this paper is to develop ail algorithm to update probabilities in influence diagrams. Pearl has designed the method of conditioning. This paper applies his algorithm for probability updates by selecting a loop-outset for tile diagram and instantiating these loop-outset nodes. It is discussed the conditions that need to be satisfied by the selected nodes. And a heuristic algorithm is presented for finding a loop-outset that satisfies these conditions.

  • PDF

A Study on Low-Current-Operation of 850nm Oxide VCSELs Using a Large-Signal Circuit Model (대신호 등가회로 모델을 이용한 850nm Oxide VCSEL의 저전류 동작 특성 연구)

  • Jang, Min-Woo;Kim, Sang-Bae
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • 제43권10호
    • /
    • pp.10-21
    • /
    • 2006
  • We have studied the characteristics of oxide VCSELS when their off-current and on-current are kept small in order to find out the possibility of low current operation. A large signal equivalent circuit model has been used. By comparing measured data and simulation results, the parameters of the large signal models are obtained including the capacitances. Using the large signal model, we have investigated the effects of capacitance and on/off currents upon the turn-on/turn-off characteristics and eye diagram. According to the experiment and simulation, the depletion capacitance, which has been neglected, is found to have significant influence on the him-on delay and eye-diagram. Therefore, for high speed and low current operation, the reduction of the depletion capacitance is essential.