• Title/Summary/Keyword: randomness

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A Randomness Test by the Entropy (Entropy에 의한 Randomness 검정법)

  • 최봉대;신양우;이경현
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 1991.11a
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    • pp.105-133
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    • 1991
  • 본 논문에서는 임의의 이진 난수발생기의 source가 $BMS_{p}$ 이거나 M-memory를 갖는 마르코프연쇄로 모델화 되었을 경우에 비트당 entropy와 관련이 있는 새로운 randomness에 관한 통계적 검정법을 제안한다. 기존에 알려진 이진 난수발생기의 randomness검정법이 0또는 1의 분포의 편향성(bias)이나 연속된 비트간의 상관성(correlation)중의 한 종류만의 non-randomness를 추적해낼 수 있는 반면에 새로운 검정법은 위의 두가지 검정을 통과하였을 때 암호학적으로 중요한 측도인 비트당 entropy 를 측정하여 암호학적인 약점을 검정할 수 있다. 또한 대칭(비밀키) 암호시스템의 통계적 결점을 바탕으로 하여 키를 찾는 공격자의 최적 전략( optimal strategy)문제를 분석하여 이 최적 전략이 이진 수열의 비트당 entropy와 밀접한 관계가 있음을 보이고 이 비트당 entropy와 관련이 있는 새로운 통계량을 도입하여 이진 난수 발생기의 source의 이진수열이 다음 3가지 경우, 즉, i.i.d. symmetric인 경우, $BMS_{p}$ 인 경우, M-memory를 갖는 마르코프연쇄인 경우의 각각에 대하여 특성을 조사하고 새로운 통계량의 평균과 분산을 구한다. 이때 구한 새로운 통계량은 잘 알려진 중심 극한 정리에 의하여 근사적으로 정규분포를 따르므로 위의 평균과 분산을 이용하여 스트림 암호시스템에서 구성요소로 많이 사용되는 몇 몇 간단한 이진 난수 발생기에 적용하여 통계적 검정을 실시함으로써 entropy 관점의 검정법이 새로운 randomness 검정법으로 타당함을 보인다.

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Seismic train-bridge coupled system sensitivity analysis considering random aftershock intensity and residual track deformation

  • Jincheng Tan;Manman Chen;Xiang Liu;Han Zhao;Lizhong Jiang;Peidong Guo;Wangbao Zhou;Ping Xiang
    • Structural Engineering and Mechanics
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    • v.91 no.1
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    • pp.25-38
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    • 2024
  • After the mainshock, whether the train can be allowed to pass the bridges plays an important role in ensuring the transport of supplies and rescue works for example, in the "12 May" earthquake in China, after evaluation, the bridge was still used for transportation in rescue at a very slow speed, engineers usually evaluate whether the train can pass the bridge safely based on the experience, lacks sufficient calculation basis and does not fully consider the risk caused by aftershocks. To address this issue, this paper comprehensively considers the randomness of track irregularity, the randomness of aftershock intensity and other multiple random sources in train-bridge interaction system (TBIS). The sensitivity of train to various random parameters after earthquake is analyzed from the perspective of probability, the most sensitive random variable in this paper is PGA of aftershocks, both for bridge and trailer car, With the increase of epicentral distance, the sensitivity of PGA will decrease, and correspondingly, for trailer car, the sensitivity of other random variables will increase, research in this paper provides a basis for the subsequent random analysis of post-earthquake driving safety.

TOA Estimation Technique for IR-UWB Based on Homogeneity Test

  • Djeddou, Mustapha;Zeher, Hichem;Nekachtali, Younes;Drouiche, Karim
    • ETRI Journal
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    • v.35 no.5
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    • pp.757-766
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    • 2013
  • This paper deals with the estimation of the time of arrival (TOA) of ultra-wideband signals under IEEE 802.15.4a channel models. The proposed approach is based on a randomness test and consists of determining whether an autoregressive (AR) process modeling an energy frame is random or not by using a distance to measure the randomness. The proposed method uses a threshold that is derived analytically according to a preset false alarm probability. To highlight the effectiveness of the developed approach, simulation setups as well as real data experiments are conducted to assess the performance of the new TOA estimation algorithm. Thereby, the proposed method is compared with the cell averaging constant false alarm rate technique, the threshold comparison algorithm, and the technique based on maximum energy selection with search back. The obtained results are promising, considering both simulations and collected real-life data.

Use of the estimated critical values adapting a regression equation for the approximate entropy test

  • Cha, Kyung-Joon;Ryu, Je-Seon
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.77-85
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    • 2002
  • The statistical testing methods have been widely recognized to determine the plain and cipher texts. In fact, the randomness for a sequence from an encryption algorithm is necessary to guarantee security and reliance of cipher algorithm. Thus, the statistical randomness tests are used to discover cipher text. In this paper, we would provide the critical value for an approximate entropy test by estimating the nonlinear regression equation when the number of sequence and the level of significance are given. Thus, we can discern plan and cipher text for real problem with given number of sequence and the level of significance. Also, we confirm the fitness of the estimated critical values from the rate of success for plain or cipher text.

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On Radar Surveillance in Statistical Perspective for the Classroom

  • Kim, G. Daniel;Kim, Sung-Sook
    • Research in Mathematical Education
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    • v.6 no.1
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    • pp.97-106
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    • 2002
  • Educators have found that the concept of randomness is often misunderstood by students. Chance recently pointed out that students should be introduced to the concept of randomness through the use of simulations. In this article, we studied various aspects of the probability distribution off linear random path in a circle and introduce some related simulations to guide student exploration and discovery. Consider a random line segment that crosses a circle with a certain radius. Perhaps it can be considered to be a path that an airplane shows up and flies into a random direction in a monitor. What is the expected amount of flying distance through the monitor, and the expected variation\ulcorner Are we monitoring what we see scientifically\ulcorner This article studies the probability distribution and some related aspects of a linear random path within a circular monitor. Some simulative activity is also introduced which can be used in a statistics or probability classes.

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Algorithm for Generating Traffic Distributions in ATM Networks using 2-D LHCA

  • Cho, Sung-Jin;Kim, Seok-Tae;Kim, Jae-Gyeom;Kim, Han-Doo;Park, Un-Sook
    • Journal of Korea Multimedia Society
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    • v.2 no.2
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    • pp.176-183
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    • 1999
  • Using Asynchronous Transfer Mode(ATM) which is a high-bandwidth, low-delay, cell switching and multiplexing technology, Broadband-Integrated Services Digital Network (B-ISDN) can support communication services of all kinds. To evaluate the performance of ATM networks, traffic source models to meet the requirements are demanded. We can obtain random traffic distribution for ATM networks by using the Cellular Automata (CA) which have effective random pattern generation capability. In this paper we propose an algorithm using 2-D LHCA to generate more effective random patterns with good random characteristics. And we show that the randomness by 2-D LHCA is better than that of the randomness by 1-D LHCA.

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A Model for Determining Optimal Input Quantity in a Semiconductor Production Line Considering Yield Randomness and Demand Uncertainty (불확실한 수율과 수요를 고려한 반도체 생산라인에서의 최적 투입량 결정모형)

  • 박광태;안봉근
    • Journal of the Korean Operations Research and Management Science Society
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    • v.20 no.1
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    • pp.27-34
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    • 1995
  • In this paper, we have developed a model to determine the input quantity to be processed at each stage of a multi-stage production system in which the yield at each stage may be random and may need reworking at this stage. Yield randomness. especially in a semiconductor industry, is a most challenging problem for production control. The demand for flnal product is uncertain. We have extended the model proposed in Park and Kim[9] to consider a multiple number of reworkings which can be done at any stage prior to or tat the stage whose output in bad, depending on the level of the defect.

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Analysis of Output Stream Characteristics Processing in Digital Hardware Random Number Generator (디지털 하드웨어 난수 발생기에서 출력열 특성 처리 분석)

  • Hong, Jin-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.3
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    • pp.1147-1152
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    • 2012
  • In this paper, it is key issue about analysis of characteristics processing of digital random output stream of hardware random number generator, which is applied in medical area. The output stream of random number generator based on hardware binary random number is effected from factors such as delay, jitter, temperature, and so on. In this paper, it presents about major factor, which effects hardware output random number stream, and the randomness of output stream data, which are combined output stream and postprocessing data such as encryption algorithm, encoding algorithm, is analyzed. the analyzed results are evaluated by major test items of randomness.

Vehicle Travel Time Analysis in Automated Guided Vehicle Systems (무인운반차 기반 물류시스템에서의 이동시간 분석)

  • 구평회;장재진
    • Journal of the Korean Operations Research and Management Science Society
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    • v.26 no.1
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    • pp.97-108
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    • 2001
  • Design and evaluation of AGV-based material handling systems are very complicated due to the randomness and the large number of variables involved Vehicle travel time is a key parameter for designing and evaluating AGV systems. Although loaded travel time is relatively easy to estimate, determination of empty vehicle travel time is difficult due to the inherent randomness of material handling systems. Most previous studies assume that the empty vehicle travel time is the same as the loaded travel time or assume very specific environments. This paper presents new vehicle travel time models for AGV-based material transport systems. The research effort is focused on the estimation of empty vehicle travel time under various vehicle dispatching policies. Simulation experiments are used to verify the proposed travel time models.

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