• Title/Summary/Keyword: probability calculation

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FAST BDD TRUNCATION METHOD FOR EFFICIENT TOP EVENT PROBABILITY CALCULATION

  • Jung, Woo-Sik;Han, Sang-Hoon;Yang, Joon-Eon
    • Nuclear Engineering and Technology
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    • v.40 no.7
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    • pp.571-580
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    • 2008
  • A Binary Decision Diagram (BDD) is a graph-based data structure that calculates an exact top event probability (TEP). It has been a very difficult task to develop an efficient BDD algorithm that can solve a large problem since it is highly memory consuming. In order to solve a large reliability problem within limited computational resources, many attempts have been made, such as static and dynamic variable ordering schemes, to minimize BDD size. Additional effort was the development of a ZBDD (Zero-suppressed BDD) algorithm to calculate an approximate TEP. The present method is the first successful application of a BDD truncation. The new method is an efficient method to maintain a small BDD size by a BDD truncation during a BDD calculation. The benchmark tests demonstrate the efficiency of the developed method. The TEP rapidly converges to an exact value according to a lowered truncation limit.

Failure Probability Prediction based on probabilistic and stochastic methods in generating units (확률 통계적 기법을 이용한 발전설비 고장확률 예측)

  • Lee, Sung-Hoon;Lee, Seung-Hyuk;Kim, Jin-O;Cha, Seung-Tae;Kim, Tae-Kyun
    • Proceedings of the KIEE Conference
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    • 2004.11b
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    • pp.69-71
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    • 2004
  • This paper presents a method to predict failure probability related to aging. To calculate failure probability, the Weibull distribution is used due to age-related reliability. The Weibull distribution has shape and scale parameters. Each estimated parameter is obtained from Data Analytic Method (Type II Censoring) which is relatively simpler and faster than the traditional calculation ways for estimating parameters. Also, this paper shows the calculation procedures of a probabilistic failure prediction through a stochastic data analysis. Consequently, the proposed methods would be likely to permit that the new deregulated environment forces utilities to reduce overall costs while maintaining an age-related reliability index.

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Numerical Calculation of Vibrational Transition Probability for the Forced Morse Oscillator by Use of the Anharmonic Boson Operators

  • Lee, Chang Sun;Kim, Yu Hang
    • Bulletin of the Korean Chemical Society
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    • v.22 no.7
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    • pp.721-726
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    • 2001
  • The vibrational transition probability expressions for the forced Morse oscillator have been derived using the commutation relations of the anharmonic Boson operators. The formulation is based on the collinear collision model with the exponential repulsive potential in the framework of semiclassical collision dynamics. The sample calculation results for H2+ He collision system, where the anharmonicity is large, are in excellent agreement with those from an exact, numerical quantum mechanical study by Clark and Dickinson, using the reactance matrix. Our results, however, are markedly different from those of Ree, Kim and Shin's in which they approximate the commutation operator I。 as unity, the harmonic oscillator limit. We have concluded that the quantum number dependence in I。 must be retained to get accurate vibrational transition probabilities for the Morse oscillator.

Reliability analysis of circular tunnel with consideration of the strength limit state

  • Ghasemi, Seyed Hooman;Nowak, Andrzej S.
    • Geomechanics and Engineering
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    • v.15 no.3
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    • pp.879-888
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    • 2018
  • Probability-based design codes have been developed to sufficiently confirm the safety level of structures. One of the most acceptable probability-based approaches is Load Resistance Factor Design (LRFD), which measures the safety level of the structures in terms of the reliability index. The main contribution of this paper is to calibrate the load and resistance factors of the design code for tunnels. The load and resistance factors are calculated using the available statistical models and probability-based procedures. The major steps include selection of representative structures, consideration of the limit state functions, calculation of reliability for the selected structures, selection of the target reliability index and calculation of load factors and resistance factors. The load and resistance models are reviewed. Statistical models of resistance (load carrying capacity) are summarized for strength limit state in bending, shear and compression. The reliability indices are calculated for several segments of a selected circular tunnel designed according to the tunnel manual report (Tunnel Manual). The novelty of this paper is the selection of the target reliability. In doing so, the uniform spectrum of reliability indices is proposed based on the probability paper. The final recommendation is proposed based on the closeness to the target reliability index.

Estimating the Transmittable Prevalence of Infectious Diseases Using a Back-Calculation Approach

  • Lee, Youngsaeng;Jang, Hyun Gap;Kim, Tae Yoon;Park, Jeong-Soo
    • Communications for Statistical Applications and Methods
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    • v.21 no.6
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    • pp.487-500
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    • 2014
  • A new method to calculate the transmittable prevalence of an epidemic disease is proposed based on a back-calculation formula. We calculated the probabilities of reactivation and of parasitemia as well as transmittable prevalence (the number of persons with parasitemia in the incubation period) of malaria in South Korea using incidence of 12 years(2001-2012). For this computation, a new probability function of transmittable condition is obtained. The probability of reactivation is estimated by the least squares method for the back-calculated longterm incubation period. The probability of parasitemia is calculated by a convolution of the survival function of the short-term incubation function and the probability of reactivation. Transmittable prevalence is computed by a convolution of the infected numbers and the probabilities of transmission. Confidence intervals are calculated using the parametric bootstrap method. The method proposed is applicable to other epidemic diseases in other countries where incidence and a long incubation period are available. We found the estimated transmittable prevalence in South Korea was concentrated in the summer with 276 cases on a peak at the $31^{st}$ week and with about a 60% reduction in the peak from the naive prevalence. The statistics of transmittable prevalence can be used for malaria prevention programs and to select blood transfusion donors.

Efficient Adaptive Algorithms Based on Zero-Error Probability Maximization (영확률 최대화에 근거한 효율적인 적응 알고리듬)

  • Kim, Namyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.5
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    • pp.237-243
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    • 2014
  • In this paper, a calculation-efficient method for weight update in the algorithm based on maximization of the zero-error probability (MZEP) is proposed. This method is to utilize the current slope value in calculation of the next slope value, replacing the block processing that requires a summation operation in a sample time period. The simulation results shows that the proposed method yields the same performance as the original MZEP algorithm while significantly reducing the computational time and complexity with no need for a buffer for error samples. Also the proposed algorithm produces faster convergence speed than the algorithm that is based on the error-entropy minimization.

Uncertainty Analysis of Dynamic Thermal Rating of Overhead Transmission Line

  • Zhou, Xing;Wang, Yanling;Zhou, Xiaofeng;Tao, Weihua;Niu, Zhiqiang;Qu, Ailing
    • Journal of Information Processing Systems
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    • v.15 no.2
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    • pp.331-343
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    • 2019
  • Dynamic thermal rating of the overhead transmission lines is affected by many uncertain factors. The ambient temperature, wind speed and wind direction are the main sources of uncertainty. Measurement uncertainty is an important parameter to evaluate the reliability of measurement results. This paper presents the uncertainty analysis based on Monte Carlo. On the basis of establishing the mathematical model and setting the probability density function of the input parameter value, the probability density function of the output value is determined by probability distribution random sampling. Through the calculation and analysis of the transient thermal balance equation and the steady- state thermal balance equation, the steady-state current carrying capacity, the transient current carrying capacity, the standard uncertainty and the probability distribution of the minimum and maximum values of the conductor under 95% confidence interval are obtained. The simulation results indicate that Monte Carlo method can decrease the computational complexity, speed up the calculation, and increase the validity and reliability of the uncertainty evaluation.

Multi-body dynamics simulation of 14 facepieces and probability study by using residual moment (14 면체의 다물체 동역학 Simulation 과 잔류 모멘트 계산을 통한 확률계산)

  • Lee, Jeong-Han;Yoo, Wan-Suk
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.865-869
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    • 2008
  • Juryeonggu is a Cuboctahedral die that had used in ancient Korea. This Cuboctahedral is consisted of different two penal servitudes of 14 facepieces, but the probability distribution can appear equally so it can be usable as a die. In this paper, achieved research study about probability of a Cuboctahedral die that have quadrilateral and triangle preferentially to search Juryeonggu's probability calculation method. First, confirmed probability distribution through Multibody-dynamics analysis and verified probability distribution through several experiments. Finally, with this simulation data, achieved theoretical analysis about Cuboctahedral die occurrence probability by using the residual momentum energy.

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Calculation of Life-Time Death Probability due Malignant Tumors Based on a Sampling Survey Area in China

  • Yuan, Ping;Chen, Tie-Hui;Chen, Zhong-Wu;Lin, Xiu-Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4307-4309
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    • 2014
  • Purpose: To calculate the probability of one person's life-time death caused by a malignant tumor and provide theoretical basis for cancer prevention. Materials and Methods: The probability of one person's death caused by a tumor was calculated by a probability additive formula and based on an abridged life table. All data for age-specific mortality were from the third retrospective investigation of death cause in China. Results: The probability of one person's death caused by malignant tumor was 18.7% calculated by the probability additive formula. On the same way, the life-time death probability caused by lung cancer, gastric cancer, liver cancer, esophageal cancer, colorectal and anal cancer were 4.47%, 3.62%, 3.25%, 2.25%, 1.11%, respectively. Conclusions: Malignant tumor is still the main cause of death in one's life time and the most common causes of cancer death were lung, gastric, liver, esophageal, colorectal and anal cancers. Targeted forms of cancer prevention and treatment strategies should be worked out to improve people's health and prolong life in China. The probability additive formula is a more scientific and objective method to calculate the probability of one person's life-time death than cumulative death probability.

A New Calculation Method of Equalizer algorithms based on the Probability Correlation (확률분포 상관도에 기반한 Equalizer 알고리듬의 새로운 연산 방식)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3132-3138
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    • 2014
  • In many communication systems, intersymbol interference, DC and impulsive noise are hard-to-solve problems. For the purpose of cancelling such interferences, the concept of lagged cross-correlation of probability has been used for blind equalization. However, this algorithm has a large burden of computation. In this paper, a recursive method of the algorithm based on the lagged probability correlation is proposed. The summation operation in the calculation of gradient of the cost is transformed into a recursive gradient calculation. The recursive method shows to reduce the high computational complexity of the algorithm from O(NM) to O(M) for M symbols and N block data having advantages in implementation while keeping the robustness against those interferences. From the results of the simulation, the proposed method yields the same learning performance with reduced computation complexity.