• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.55-64
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• 2004

Many researchers have made a lot of progress in studying the evaluation of fracture probability of brittle materials. However, studies of fracture probability for elastic-plasticity have not been made yet. An evaluation method for fracture probability which is grafted onto a 2-parameter criterion and statistical probability analysis is not only introduced in this study, but also applied to the simple 2-dimensional model and carbon steel piping to vealuate the effect of statistical variables.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.97-106
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• 1996

One of the main problems in evaluating complex objects, such as an ill-defined system, is how to treat ambiguous aspect of the evaluation. Due to the Complexity and ambiguity of the objects, many types of evaluation attributes should be identified based on the rational dsision. One of these attributes is an analytical hierarchy process (AHP). the weight of evaluation attribtes in AHP however comes from the probability measure based on the additivity. Therefore, it is notapplicable to the objects which have the property of non-additivity. In the previous studies by other researchers they intriduced the Hierarchical Fuzzy Integral method or mergd AHP and fuzzy measure for the analysis of the overlaps among the evaluation objects. But, they need more anlyses in terms of transformation of the probability measure into fuzzy measure which fits for the additivity and overlapping coefficient which affects to the fuzzy measure. Considering these matters, this paper deals that, ⅰ) clarifying the relation between the fuzzy and probability measure adopted in AHP, ii) calculating directly the family of fuzzy measure from the overlapping coefficient and probability measure. A simple algorithm for the calculation of fuzzy measures and set family of those from the above results is also proposed. Finally, the effectiveness of the algorithm developed by applying this to the problems for estimation of safety in ship berthing and for evaluation of ports in competition is verified. This implied that the new algoritnm gives better description of the system evaluation.

• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.395-403
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• 2017

An efficient evaluation method for the probability of a tornado missile strike without using the Monte Carlo method is proposed in this paper. A major part of the proposed probability evaluation is based on numerical results computed using an in-house code, Tornado-borne missile analysis code, which enables us to evaluate the liftoff and flight behaviors of unconstrained objects on the ground driven by a tornado. Using the Tornado-borne missile analysis code, we can obtain a stochastic correlation between local wind speed and flight distance of each object, and this stochastic correlation is used to evaluate the conditional strike probability, $Q_V(r)$, of a missile located at position r, where the local wind speed is V. In contrast, the annual exceedance probability of local wind speed, which can be computed using a tornado hazard analysis code, is used to derive the probability density function, p(V). Then, we finally obtain the annual probability of tornado missile strike on a structure with the convolutional integration of product of $Q_V(r)$ and p(V) over V. The evaluation method is applied to a simple problem to qualitatively confirm the validity, and to quantitatively verify the results for two extreme cases in which an object is located just in the vicinity of or far away from the structure.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.225-234
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• 2018

In this paper, we consider a problem of partitioning a search area into smaller rectangular regions, so that multiple platforms can conduct search operations independently without requiring unnecessary coordination among themselves. The search area consists of cells where each cell has some prior information regarding the probability of target existence. The detection probability in particular cell is evaluated by multiplying the observation probability of the platform and the target existence probability in that cell. The total detection probability within the search area is defined as the cumulative detection probability for each cell. However, since this search area partitioning problem is NP-Hard, we decompose the problem into three sequential phases to solve this computationally intractable problem. Additionally, we discuss a special case of this problem, which can provide an optimal analytic solution. We also examine the performance of the proposed approach by comparing our results with the optimal analytic solution.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.48-53
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• 2007

A new way to integrate various geophysical information for evaluation of RQD was developed. In this study, we did not directly define the RQD value where borehole data are not sampled. Instead, we infer the probability of RQD values with prior probability from borehole direct data, and secondary supporting probability from resistivity and seismic tomography data. For the integration, we applied the geostatstical indicator kriging to get prior probability of RQD value, and indicator kriging with soft data to get the supporting probability from resistivity and seismic data. And we finally use the permanence ratio rule to integrate these information. The finally obtained result was also analyzed to fully utilize the probabilistic features. We show the probability of wrongly classifying the RQD evaluation and vice versa. This result may be used for decision making process based on the geophysical exploration.

• Journal of the military operations research society of Korea
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• v.23 no.1
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• pp.1-13
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• 1997

This research investigates a kill probability model for the performance evaluation of guided missile system, and also develops the user interface implementation for the output of the model based on the visual object-oriented programming application. This paper describes in detail the methodology for the kill probability attained by a missile warhead detonating near an airborne target. The major simulation events used in this research are missile guidance homing point, burst points, and kill mechanism(direct kill, blast kill and fragment kill). For the user interface, we also design and implement the visualization system that can show the graphic style of the kill probability attained by the model. This research will bridge the gap between the sophisticated kill probability model and users who want to see the results interactively with visualization, which can benefit many of other military systems. Some examples are shown, but these will be improved to be better with visual simulation which can visualize all the simulation process of the model.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.491-501
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• 2021

This paper aims to evaluate the mechanical integrity for Spent Nuclear Fuel (SNF) cladding under lateral loads during transportation. The evaluation process requires a conservative consideration of the degradation conditions of SNF cladding, especially the hydride effect, which reduces the ductility of the cladding. The dynamic forces occurring during the drop event are pinch force, axial force and bending moment. Among those forces, axial force and bending moment can induce transverse tearing of cladding. Our assessment of 14 × 14 PWR SNF was performed using finite element analysis considering SNF characteristics. We also considered the probabilistic procedures with a Monte Carlo method and a reliability evaluation. The evaluation results revealed that there was no probability of damage under normal conditions, and that under accident conditions the probability was small for transverse failure mode.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.15-24
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• 2006

In simulation input modeling, it is important to identify a probability distribution to represent the input process of interest. In this paper, an appropriate sample size is determined for parameter estimation associated with some typical probability distributions frequently encountered in simulation input modeling. For this purpose, a statistical measure is proposed to evaluate the effect of sample size on the precision as well as the accuracy related to the parameter estimation, square rooted mean square error to parameter ratio. Based on this evaluation measure, this sample size effect can be not only analyzed dimensionlessly against parameter's unit but also scaled regardless of parameter's magnitude. In the Monte Carlo simulation experiments, three continuous and one discrete probability distributions are investigated such as ; 1) exponential ; 2) gamma ; 3) normal ; and 4) poisson. The parameter's magnitudes tested are designed in order to represent distinct skewness respectively. Results show that ; 1) the evaluation measure drastically improves until the sample size approaches around 200 ; 2) up to the sample size about 400, the improvement continues but becomes ineffective ; and 3) plots of the evaluation measure have a similar plateau pattern beyond the sample size of 400. A case study with real datasets presents for verifying the experimental results.

• The Mathematical Education
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• v.42 no.2
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• pp.203-218
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• 2003

The purpose of this study is to see what the essential characteristics are in teaching probability and statistics among various mathematical fields. we also tried to connect the study of probability and statistics education with what is needed for a science be synthetic to have its own identity as a unique research field. Since we searched for the future direction of the pedagogic study in the probability and statistics we first selected papers on probability and statistics published in (Series A), the Journal of Korea Society of Mathematical Education, and establish the following research questions. What kinds of characteristics can be found when papers on probability and statistics published in (Series A) are classified into low categories; contents of probability and statistics education, research method of the mathematics education, methods of teaming and teaching, and finally measurements and evaluation\ulcorner We classified papers into two kinds. One is related to the educational contents, consisting of the methods of learning and teaching, and of the measurement and evaluation. The other is reined to the methods of research, which is not a part of the educational curriculum but is essential for establishing the identity of mathematics education. According to the periods, papers on the curricular contents in 1960s were influenced by the New Mathematics, and papers on the curricular contents in 1980s were influenced by 'back to basic'. In 1990s, papers on methods of learning and teaching, and measurement md evaluation were increasing in number. Besides, (series A) from the Journal of Korea Society of Mathematical Education covers contents, methods of Loaming and teaching, and measurement and evaluation. And when I examined the papers on the contents of textbook of a junior high school related to the probability and statistics education and on methods of learning and teaching, 1 found that those papers occupy 1.84% in . When it comes to the methods of loaming and teaching, most of studies in (series A) are about application of concrete implement like experiment and practical application of computer programs, Through this study, I found that over-all and more active researches on probability and statistics are required and that the studies about methods of loaming and teaching must be made in diverse directions. It is needed that how students recognize probability and statistics, connection, communication and representation in probability and statistics context, too. (series A) does not have papers on methods of study. Mathematics pedagogy is a mixture of various studies - mathematical psychology, mathematical philosophy, the history of mathematics and Mathematics. So If there doesn't exist a proper method of study adequate in the situation for the mathematics education the issue of mathematics pedagogy might be taken its own place by that of other studies'. We must search for the unique method of study fur mathematics education so that mathematics pedagogy has its own identity as a study. The study concerning this aspect is needed.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.203-207
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• 2005

A loss system where two types of customers arrive in accordance with two independent Poisson processes is considered. An efficient recursive formula is developed for calculating the loss probability when the number of servers is large. Some practical examples regarding the performance evaluation of telecommunications networks are discussed.