• 제목/요약/키워드: Failure Probability

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3차원 수리모형을 이용한 농업용 저수지의 파괴확률에 따른 하류부 피해예측 모델 개발 (Development of Downstream Flood Damage Prediction Model Based on Probability of Failure Analysis in Agricultural Reservoir)

  • 전정배;윤성수;최원
    • 한국농공학회논문집
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    • 제62권3호
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    • pp.95-107
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    • 2020
  • The failures of the agricultural reservoirs that most have more than 50 years, have increased due to the abnormal weather and localized heavy rains. There are many studies on the prediction of damage from reservoir collapse, however, these referenced studies focused on evaluating reservoir collapse as single unit and applyed to one and two dimensional hydrodynamic model to identify the fluid flow. This study is to estimate failure probability of spillway, sliding, bearing capacity and overflowing targeting small and medium scale agricultural reservoirs. In addition, we calculate failure probability by complex mode. Moreover, we predict downstream flood damage by reservoir failure applying three dimensional hydrodynamic model. When the reservoir destroyed, the results are as follows; (1) the flow of fluid proceeds to same stream direction and to a lower slope by potential and kinetic energy; (2) The predicted damage in downstream is evaluated that damage due to building destruction is the highest.

The Video on Demand System Failure Evaluation of Software Development Step

  • Jang, Jin-Wook
    • 한국컴퓨터정보학회논문지
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    • 제24권4호
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    • pp.107-112
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    • 2019
  • Failure testing is a test that verifies that the system is operating in accordance with failure response requirements. A typical failure test approaches the operating system by identifying and testing system problems caused by unexpected errors during the operational phase. In this paper, we study how to evaluate these Failure at the software development stage. Evaluate the probability of failure due to code changes through the complexity and duplication of the code, and evaluate the probability of failure due to exceptional situations with bugs and test coverage extracted from static analysis. This paper studies the possibility of failure based on the code quality of software development stage.

TiGER의 복호화 실패율 분석 (Analysis on Decryption Failure Probability of TiGER)

  • 이승우;김종현;박종환
    • 정보보호학회논문지
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    • 제34권2호
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    • pp.157-166
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    • 2024
  • LWE(learning with errors) 문제 기반의 공개키 암호는 기법 설계 및 파라미터 설정에 따라 복호화 실패율이 주어지는데, 높은 복호화 실패율은 실용성의 저하를 불러올뿐만 아니라 기법에 대한 공격으로 이어질 수 있음이 밝혀진 바 있다[1]. 따라서, KpqC 1차 라운드에 제안된 Ring-LWE 기반 KEM 기법인 TiGER[2]는 오류 보정 코드 (error correction code) Xef와 D2 인코딩 방법을 사용함으로써 복호화 실패율을 낮추고자 하였다. 그런데, Ring-LWE 문제에 기반한 암호화 기법 중 오류 보정 코드를 사용하는 기법의 경우 흔히 가정하는 각 비트 오류의 독립성이 성립하지 않음이 알려진 바 있다[3]. TiGER의 복호화 실패율 계산은 이를 고려하지 않은바, 본 논문에서는 오류 의존성을 고려하여 복호화 실패율을 다시 계산한다. 또한, TiGER(v2.0)의 비트 오류가 잘못 계산되었음을 발견하여 올바른 비트 오류 계산 식과 그에 따라 새로 계산한 복호화 실패율을 제시한다.

확률함수를 이용한 비균질 Ti-6Al-4V 합금의 변형거동 모델링 (Modeling Deformation Behavior of Heterogenous Microstructure of Ti-6AI-4V Alloy using Probability Functions)

  • 고은영;김태원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.292-297
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    • 2003
  • A stochastic approach has been presented for superplastic deformation of Ti-6AJ-4V alloy, and probability function are used to heterogeneous phase distributions. The experimentally observed spatial correlation function are developed, and microstructural evolutions together with superplastic deformation behavior have investigated by means of the probability function. The result have shown that the probability varies approximately linearly with separation with distance, and significant deformation enhanced probability changes during the deformation. The stress-strain behavior with the evolutions of probability function can be correctly predicted by the model. The finite clement implementation using Monte Carlo simulation associated with phase re-distributions shows that better agreement with experimental data of failure strain on the test specimen.

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복합 반응면 기법을 이용한 복합재 적층판의 신뢰성해석 (Reliability Analysis for Composite Laminated Plate Using Hybrid Response Surface Method)

  • 이석제;김인걸
    • Composites Research
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    • 제23권2호
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    • pp.40-47
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    • 2010
  • 본 논문에서는 복합 반응면 기법을 제안하고 성능을 고찰하였다. 복합 반응면 기법은 MPP의 좌표를 기준으로 하여 근사모델을 반복 계산하는 기법이다. 성능을 검증하기 위해 비선형 함수와 복합재 적층판에 대하여 신뢰성 해석 기법을 적용하여 파괴확률, MPP(Most Probable failure Point), 신뢰도 지수를 계산하고 일반적인 반응면 기법의 결과와 비교하였다. 파괴확률은 비선형 한계상태식을 가정하고 임의의 파괴 기준을 정의하여 계산하였다. 제안한 복합 반응면 기법을 이용하여 파괴확률을 계산한 결과 일반적인 반응면 기법보다 향상된 성능을 나타내었다.

베이즈 규칙을 활용한 배전선로 위험도 평가모델 -가공배전분야- (A Risk Evaluation Model of Power Distribution Line Using Bayesian Rule -Overhead Distribution System-)

  • 정종만;박용우
    • 전기학회논문지
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    • 제62권6호
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    • pp.870-875
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    • 2013
  • After introducing diagnosis equipment power failure prevention activities for distribution system have become more active. To do facility diagnosis and maintenance work more efficiently we need to evaluate reliability for the system and should determine the priority line with appropriate criteria. Thus, to calculate risk factor for the power distribution line that are composed of many component facilities its historical failure events for the last 5 years are collected and analysed. The failure statics show that more than 60% of various failures are related to environment factors randomly and about 20% of the failures are refer to the aging. As a strategic evaluation system reflecting these environmental influence is needed, a system on the basis of the probabilistic approach related statical variables in terms of failure rate and failure probability of electrical components is proposed. The figures for the evaluation are derived from the field failure DB. With adopting Bayesian rule we can calculate easily about conditional probability query. The proposed evaluation system is demonstrated with model system and the calculated indices representing the properties of the model line are discussed.

Consumer Misperceptions, Product Liability Law and Product Safety

  • Lee Jong-In
    • International Journal of Human Ecology
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    • 제6권2호
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    • pp.63-72
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    • 2005
  • This paper considered the impact of changing the product liability rule from consumer to producer liability on product safety under asymmetric information. In particular, it has been attempted to remove several constraints on antecedent studies. The main results of the study are as follows: under the misperception of the risk on a product, consumers may underestimate the probability of product failure. In this case, the accident rate can be lowered under the producer's liability rule. However, even under the asymmetric information, a consumer's estimation on the probability may be converged with the expected risk level, which could be called the 'rational expectation.' In this situation the probability of product failure can be lowered under the strict liability with contributory negligence. Additionally, it is possible to reduce the probability of product failure when a legal rule that imposes liability on cheapest cost avoider is admitted.

Prediction of Durability for RC Columns with Crack and Joint under Carbonation Based on Probabilistic Approach

  • Kwon, Seung-Jun;Na, Ung-Jin
    • International Journal of Concrete Structures and Materials
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    • 제5권1호
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    • pp.11-18
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    • 2011
  • Carbonation in RC (reinforced concrete) structure is considered as one of the most critical deteriorations in urban cities. Although RC column has one mix condition, carbonation depth is measured spatially differently due to its various environmental and internal conditions such as sound, cracked, and joint concrete. In this paper, field investigation was performed for 27 RC columns subjected to carbonation for eighteen years. Through this investigation, carbonation distribution in sound, cracked, and joint concrete were derived with crack mappings. Considering each related area and calculated PDF (probability of durability failure) of sound, cracked, and joint concrete through Monte Carlo Simulation (MCS), repairing timings for RC columns are derived based on several IPDF (intended probability of durability failure) of 1, 3, and 5%. The technique of equivalent probability including carbonation behaviors which are obtained from different conditions can provide the reasonable repairing strategy and the priority order for repairing in a given traffic service area.

A New Methodology for the Rapid Calculation of System Reliability of Complex Structures

  • Park, Sooyong
    • Architectural research
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    • 제3권1호
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    • pp.71-80
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    • 2001
  • It is quite difficult to calculate the collapse probability of a system such as statically indeterminate structure that has many possible modes or paths to complete failure and the problem has remained essentially unsolved. A structure is synthesized by several components or elements and its capacity to resist the given loads is a function of the capacity of the individual element. Thus it is reasonable to assess the probability of failure of the system based upon those of its elements. This paper proposes an efficient technique to directly assess the reliability of a complex structural system from the reliabilities of its components or elements. The theory for the calculation of the probability of a structural system is presented. The target requirements of the method and the fundamental assumptions governing the method are clearly stated. A portal frame and two trusses are selected to demonstrate the efficiency of the method by comparing the results obtained from the proposed method to those from the existing methods in the literature.

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관개조직의 수명기간 신뢰성 해석 (Lifetime Reliability Analysis of Irrigation System)

  • Kim Han-Joong;Lee Jeong-Jae;Im Sang-Joon
    • 한국농공학회지
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    • 제45권2호
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    • pp.35-44
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    • 2003
  • A system reliability method is proposed to decide reliable serviceability of agricultural irrigation system. Even though reliability method is applied to real engineering situations involving actual life environments and maintaining costs, a number of Issues arise as a modeling and analysis level. This article use concepts that can be described the probability of failure with time variant and series-parallel system reliability analysis model. A proposed method use survivor function that can simulate a time-variant performance function for a lifetime before it is required essential maintenance or replacement to define a target probability of failure in agricultural irrigation canal. In the further study, it is required a relationship between a state of probability of failure and current serviceability to make the optimum repair strategy to maintain appropriate serviceability of an irrigation system.