• Title/Summary/Keyword: probability-based

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Naval ship's susceptibility assessment by the probabilistic density function

  • Kim, Kwang Sik;Hwang, Se Yun;Lee, Jang Hyun
    • Journal of Computational Design and Engineering
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    • v.1 no.4
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    • pp.266-271
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    • 2014
  • The survivability of the naval ship is the capability of a warship to avoid or withstand a hostile environment. The survivability of the naval ship assessed by three categories (susceptibility, vulnerability and recoverability). The magnitude of susceptibility of a warship encountering with threat is dependent upon the attributes of detection equipment and weapon system. In this paper, as a part of a naval ship's survivability analysis, an assessment process model for the ship's susceptibility analysis technique is developed. Naval ship's survivability emphasizing the susceptibility is assessed by the probability of detection, and the probability of hit. Considering the radar cross section (RCS), the assessment procedure for the susceptibility is described. It's emphasizing the simplified calculation model based on the probability density function for probability of hit. Assuming the probability of hit given a both single-hit and multiple-hit, the susceptibility is accessed for a RCS and the hit probability for a rectangular target is applied for a given threat.

Real-Time Motion Estimation Algorithm for Mobile Surveillance Robot (모바일 감시 로봇을 위한 실시간 움직임 추정 알고리즘)

  • Han, Cheol-Hoon;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.311-316
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    • 2009
  • This paper presents the motion estimation algorithm on real-time for mobile surveillance robot using particle filter. the particle filter that based on the monte carlo's sampling method, use bayesian conditional probability model which having prior distribution probability and posterior distribution probability. However, the initial probability density was set to define randomly in the most of particle filter. In this paper, we find first the initial probability density using Sum of Absolute Difference(SAD). and we applied it in the partical filter. In result, more robust real-time estimation and tracking system on the randomly moving object was realized in the mobile surveillance robot environments.

A 3D analytical model for the probabilistic characteristics of self-healing model for concrete using spherical microcapsule

  • Zhu, Hehua;Zhou, Shuai;Yan, Zhiguo;Ju, Woody;Chen, Qing
    • Computers and Concrete
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    • v.15 no.1
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    • pp.37-54
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    • 2015
  • In general, cracks significantly deteriorate the in-situ performance of concrete members and structures, especially in urban metro tunnels that have been embedded in saturated soft soils. The microcapsule self-healing method is a newly developed healing method for repairing cracked concrete. To investigate the optimal microcapsule parameters that will have the best healing effect in concrete, a 3D analytical probability healing model is proposed; it is based on the microcapsule self-healing method's healing mechanism, and its purpose is to predict the healing efficiency and healing probability of given cracks. The proposed model comprehensively considers the radius and the volume fraction of microcapsules, the expected healing efficiency, the parameters of cracks, the broken ratio and the healing probability. Furthermore, a simplified probability healing model is proposed to facilitate the calculation. Then, a Monte Carlo test is conducted to verify the proposed 3D analytical probability healing model. Finally, the influences of microcapsules' parameters on the healing efficiency and the healing probability of the microcapsule self-healing method are examined in light of the proposed probability model.

Call Admission Control Based on Adaptive Bandwidth Allocation for Wireless Networks

  • Chowdhury, Mostafa Zaman;Jang, Yeong Min;Haas, Zygmunt J.
    • Journal of Communications and Networks
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    • v.15 no.1
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    • pp.15-24
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    • 2013
  • Provisioning of quality of service (QoS) is a key issue in any multi-media system. However, in wireless systems, supporting QoS requirements of different traffic types is a more challenging problem due to the need to simultaneously minimize two performance metrics - the probability of dropping a handover call and the probability of blocking a new call. Since QoS requirements are not as stringent for non-real-time traffic, as opposed to real-time traffic, more calls can be accommodated by releasing some bandwidth from the already admitted non-real-time traffic calls. If the released bandwidth that is used to handle handover calls is larger than the released bandwidth that is used for new calls, then the resulting probability of dropping a handover call is smaller than the probability of blocking a new call. In this paper, we propose an efficient call admission control algorithm that relies on adaptive multi-level bandwidth-allocation scheme for non-realtime calls. The scheme allows reduction of the call dropping probability, along with an increase in the bandwidth utilization. The numerical results show that the proposed scheme is capable of attaining negligible handover call dropping probability without sacrificing bandwidth utilization.

A Study on Development of WBI Program and Application for Learning Probability and Statistics in the Middle School (웹 기반의 중학교 확률과 통계를 중심으로 한 WBI 프로그램 개발 및 적용에 관한 연구)

  • 강청귀
    • Journal of the Korean School Mathematics Society
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    • v.4 no.2
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    • pp.49-60
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    • 2001
  • This paper is dedicated to the enhancement of the second-grade students of middle school students' understanding of the basic principles and concepts of probability with the help of Web-browser-used WBI programs relating to probability and statistics in teaching them the unit of probability. I have come up with the following research problems with a view to applying and analyzing the findings. (1) A web sites in relation to the learning of probability and statistics is to be developed with the second graders of middle school in mind. (2) Is there any difference between the experiment group exposed to web-sites-aided classes and the control group going through the conventional ways of math classes when the sites is made trial use of \ulcorner (3) What response do the learners show in regard to classes which makes use of the web sites when the sites is applied\ulcorner After making an experiment with the aid of the web sites and teaching plans, I made a measurement and an analysis of the academic achievement of the subjects, their understanding of classes based on the web sites, the concentration of the learners, and their responses relating to the contents of web sites concentrating on probability and statistics. I have come to the following conclusions based on the findings. First there was a significant difference between the classes of honor students and the classes of backward pupils when T-Test was made with regard to the achievement of the subjects who divided into the experiment group and the control group. The former made use of the web sites whereas the latter stuck to the conventional way of teaching math. The former scored higher than the latter. Second, the research based on questionnaire findings shows that the web-site-aided experiment classes proved to be more effective than the traditional control classes. All in all, I think that web-aided classes will have a more positive influence on the students' interest in math and on the scholastic achievement of math than conventional classes.

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Estimate of First-Passage Probability for Hazard Fluctuating Wind Velocity (재난 변동풍속의 최초파괴확률 평가)

  • Oh, Jong Seop;Heo, Seong Je
    • Journal of Korean Society of Disaster and Security
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    • v.6 no.2
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    • pp.23-30
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    • 2013
  • A dynamic analysis of random vibration processes is concerned with the first excursion probability based on first passage time during some specified lifetime or duration of the excitation. This study is concerned with the estimation of first-passage probability for hazard fluctuate wind velocity in the major cities reflecting the recent meteorological with largest data samples (yearly 2003-2012). The basic wind speeds were standardized homogeneously to the surface roughness category C, and to 10m above the ground surface. In this paper, the hazard fluctuate wind velocities are treated as a time-independent (stationary) random process and Gaussian random processes. The first excursion probability were calculated from Poisson model based on the independent event of level crossing & two-state Markov model based on the envelopes of level crossing.

System Reliability Analysis of Rack Storage Facilities (물류보관 랙선반시설물의 시스템신뢰성 해석)

  • Ok, Seung-Yong;Kim, Dong-Seok
    • Journal of the Korean Society of Safety
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    • v.29 no.4
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    • pp.116-122
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    • 2014
  • This study proposes a system reliability analysis of rack storage facilities subjected to forklift colliding events. The proposed system reliability analysis consists of two steps: the first step is to identify dominant failure modes that most contribute to the failure of the whole rack facilities, and the second step is to evaluate the system failure probability. In the first step, dominant failure modes are identified by using a simulation-based selective searching technique where the contribution of a failure mode to the system failure is roughly estimated based on the distance from the origin in the space of the random variables. In the second step, the multi-scale system reliability method is used to compute the system reliability where the first-order reliability method (FORM) is initially used to evaluate the component failure probability (failure probability of one member), and then the probabilities of the identified failure modes and their statistical dependence are evaluated, which is called as the lower-scale reliability analysis. Since the system failure probability is comprised of the probabilities of the failure modes, a higher-scale reliability analysis is performed again based on the results of the lower-scale analyses, and the system failure probability is finally evaluated. The illustrative example demonstrates the results of the system reliability analysis of the rack storage facilities subjected to forklift impact loadings. The numerical efficiency and accuracy of the approach are compared with the Monte Carlo simulations. The results show that the proposed two-step approach is able to provide accurate reliability assessment as well as significant saving of computational time. The results of the identified failure modes additionally let us know the most-critical members and their failure sequence under the complicated configuration of the member connections.

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

  • Seungwoo Lee;Jonghyun Kim;Jong Hwan Park
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.34 no.2
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    • pp.157-166
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    • 2024
  • Probability of decryption failure of a public key cryptography based on LWE(learning with errors) is determined by its architecture and parameter settings. Since large decryption failure probability leads to attacks[1] on scheme as well as degradation of performance, TiGER[2], a Ring-LWE(R)-based KEM proposed for the first round of KpqC, tried to reduce the decryption failure probability by using error correction code Xef and D2 encoding method. However, D'Anvers et al. has shown that the commonly assumed independence of each bit error is not established since in the case of an encryption scheme based on Ring-LWE(R) using an error correction code, there is error dependency which is not negligible[3]. In this paper, since TiGER does not consider the error dependency, we calcualte the decryption failure probability of TiGER by considering the error dependency. In addition, we found that the bit error probability is incorrectly calculated in TiGER, so we present the correct calculation.

Estimation of underwater acoustic uncertainty based on the ocean experimental data measured in the East Sea and its application to predict sonar detection probability (동해 해역에서 측정된 해상실험 데이터 기반의 수중음향 불확정성 추정 및 소나 탐지확률 예측)

  • Dae Hyeok Lee;Wonjun Yang;Ji Seop Kim;Hoseok Sul;Jee Woong Choi;Su-Uk Son
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.3
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    • pp.285-292
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    • 2024
  • When calculating sonar detection probability, underwater acoustic uncertainty is assumed to be normal distributed with a standard deviation of 8 dB to 9 dB. However, due to the variability in experimental areas and ocean environmental conditions, predicting detection performance requires accounting for underwater acoustic uncertainty based on ocean experimental data. In this study, underwater acoustic uncertainty was determined using measured mid-frequency (2.3 kHz, 3 kHz) noise level and transmission loss data collected in the shallow water of the East Sea. After calculating the predictable probability of detection reflecting underwater acoustic uncertainty based on ocean experimental data, we compared it with the conventional detection probability results, as well as the predictable probability of detection results considering the uncertainty of the Rayleigh distribution and a negatively skewed distribution. As a result, we confirmed that differences in the detection area occur depending on each underwater acoustic uncertainty.

A Study on Experiments and Two Interpretations of Probability in 《Probability and Statistics》 and Its Educational Implications (《확률과 통계》의 시행과 두 가지 확률에 대한 고찰 및 교육적 시사점)

  • Lee, Gi Don
    • Journal for History of Mathematics
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    • v.31 no.5
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    • pp.251-269
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    • 2018
  • Empirical probability and classical probability, which are two interpretations of Kolmogorov's axiom, are two ways to recognize the chances of events occurring in the real world. In this paper, I analyzed and suggested the contents of the high school textbooks ${\ll}$Probability and Statistics${\gg}$, associated with two interpretations of probability and experiments on which two interpretations are based. By presenting the cases required expressly stating what the experiment is for supporting students' understanding of some concepts, it was discussed that stating or not stating what the experiment is should be carefully determined by the educational intent. Especially, I suggested that in the textbooks we contrast the good idea of calculating the ratios of two possibilities in the imaginary world of the classical probability with the normal idea of grasping the chances of events through the frequencies in the real world of the empirical probability, with distinguishing the experiments in two interpretations of probability. I also suggested that in the textbooks we make it clear that the Weak Law of Large Numbers justifies our expectations of the frequencies' reflecting the chances of events occurring in the real world under ideal conditions. Teaching and learning about the aesthetic elements and the practicality of imaginary mathematical thinking supported by these textbooks statements could be one form of Humanities education in mathematics as STEAM education.