• 제목/요약/키워드: Random Number Generation

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RMS 가속도에 의한 인공 지진파 생성기법 (Generation of RMS Hazard-Compatible Artificial Earthquake Ground Motions)

  • 김진만
    • 한국지진공학회논문집
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    • 제7권1호
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    • pp.31-40
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    • 2003
  • 지진응답 해석 시 불확실한 지진현상을 추정하여 설계지진파를 선정하는 것은 어려운 일 중의 하나이다. 게다가 제한된 숫자의 설계인자에 상응하는 지진파가 결코 유일하지 않다는 문제도 있다. 따라서 동일한 설계진도에 상응하는 여러 지진파들로부터 구한 응답치들이 서로 크게 차이가 날 수 있다. 본 논문은 이 같은 지진하중의 불확실성을 체계적으로 고려하는 실용적인 지진파 생성 기법을 제시한다. 이 기법은 에너지 개념의 RMS 지진가속도에 기반하며 주요 지진파 설계인자의 불확실성을 고려한다. 시뮬레이션을 통해, 이 새로운 RMS 기법이 지진재해에 상응하는 지진파를 대량 생성하는 경우에 적합하며 따라서 소량의 지진파 생성에 적합한 기존의 방법들과 비교할 때 특히 확률론적 지진응답 해석 시 유용하다는 점을 확인하였다.

Evaluation of Inbreeding and Genetic Variability of Five Pig Breeds in Czech Republic

  • Krupa, Emil;Zakova, E.;Krupova, Z.
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권1호
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    • pp.25-36
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    • 2015
  • The complex analysis of the pedigree records of Czech Landrace (CLA), Czech Large White-dam line (CLWd), Czech Large White-sire line (CLWs), Duroc (DC), and Pietrain (PN) was performed to determine trends of genetic diversity (GD), and to find the main sources of the GD loss. The total size of the pedigree was 132,365, 391,151, 32,913, 13,299, and 7,160 animals in CLA, CLWd, CLWs, DC, and PN, respectively. Animals born in the years 2011 through 2013 were assumed as the reference population. The average pedigree completeness index for one generation back was 95.9%, 97.4%, 91.2%, 89.8%, and 94.2% for appropriate breeds. Number of ancestors explaining 100% of gene pool was 186, 373, 125, 157, and 37 in CLA, CLWd, CLWs, DC, and PN, respectively. The relative proportion of inbred animals (58%, 58%, 54%, 47%, and 25%), the average inbreeding (2.7%, 1.4%, 2.5%, 3.6%, and 1.3%) and the average co-ancestry (3.1%, 1.6%, 3.3%, 4.2%, and 3.3%) were found over the past decade in analysed breeds. The expected inbreeding under random mating increased during the last 10 years in CLWs and PN and varied from 1.27% to 3.2%. The effective population size computed on the basis of inbreeding was 76, 74, 50, 35, and 83 in 2012 in CLA, CLWd, CLWs, DC, and PN, respectively. The shortest generation interval (1.45) was observed for CLWd in sire to son selection pathway. The longest generation interval obtained PN (1.95) in sire to daughter pathway. The average relative GD loss within last generation interval was 7.05%, 4.70%, 9.81%, 7.47%, and 10.46%, respectively. The relative proportion of GD loss due to genetic drift on total GD loss was 85.04%, 84.51%, 89.46%, 86.19%, and 83.68% in CLA, CLWd, CLWs, DC, and PN, respectively. All breeds were characterized by a high proportion of inbred animals, but the average inbreeding was low. The most vulnerable breeds to loss of GD are DC and PN. Therefore, a breeding program should be more oriented to prevent the increase of GD loss in these breeds.

DEVS 형식론을 이용한 다중프로세서 운영체제의 모델링 및 성능평가

  • 홍준성
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 1994년도 추계학술발표회 및 정기총회
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    • pp.32-32
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    • 1994
  • In this example, a message passing based multicomputer system with general interdonnedtion network is considered. After multicomputer systems are developed with morm-hole routing network, topologies of interconecting network are not major considertion for process management and resource sharing. Tehre is an independeent operating system kernel oneach node. It communicates with other kernels using message passingmechanism. Based on this architecture, the problem is how mech does performance degradation will occur in the case of processor sharing on multicomputer systems. Processor sharing between application programs is veryimprotant decision on system performance. In almost cases, application programs running on massively parallel computer systems are not so much user-interactive. Thus, the main performance index is system throughput. Each application program has various communication patterns. and the sharing of processors causes serious performance degradation in hte worst case such that one processor is shared by two processes and another processes are waiting the messages from those processes. As a result, considering this problem is improtant since it gives the reason whether the system allows processor sharingor not. Input data has many parameters in this simulation . It contains the number of threads per task , communication patterns between threads, data generation and also defects in random inupt data. Many parallel aplication programs has its specific communication patterns, and there are computation and communication phases. Therefore, this phase informatin cannot be obtained random input data. If we get trace data from some real applications. we can simulate the problem more realistic . On the other hand, simualtion results will be waseteful unless sufficient trace data with varisous communication patterns is gathered. In this project , random input data are used for simulation . Only controllable data are the number of threads of each task and mapping strategy. First, each task runs independently. After that , each task shres one and more processors with other tasks. As more processors are shared , there will be performance degradation . Form this degradation rate , we can know the overhead of processor sharing . Process scheduling policy can affects the results of simulation . For process scheduling, priority queue and FIFO queue are implemented to support round-robin scheduling and priority scheduling.

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최대길이 여원 CA 기반의 의사랜덤수열 분석 (Analysis of Pseudorandom Sequences Generated by Maximum Length Complemented Cellular Automata)

  • 최언숙;조성진
    • 한국전자통신학회논문지
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    • 제14권5호
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    • pp.1001-1008
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    • 2019
  • 고품질 의사랜덤수열 생성은 암호화 프로토콜을 포함한 많은 암호화 응용 프로그램에서 매우 중요한 부분이다. 그러므로 의사랜덤수열 생성기(Pseudo Random Number Generator, 이하 PRNG)는 암호시스템에서 키수열 생성하는데 꼭 필요한 요소이다. PRNG는 고품질의 랜덤한 큰 데이터 스트림을 효과적으로 생성해야 한다. CA 기반의 PRNG는 LFSR기반의 PRNG에 의해 출력되는 난수열보다 랜덤성이 우수하다는 사실은 이미 잘 알려져 있다. 본 논문에서는 비밀키 암호시스템에서 보다 안전한 비트스트림을 생성하고 키 공간을 확장할 수 있는 PRNG를 설계하기 위해 최대길이를 갖는 90/150 셀룰라 오토마타(Cellular Automata, CA)로부터 유도된 여원 CA가 최대길이 CA임을 보인다. 또한 90/150 최대길이 CA(MLCA)와 여원벡터로부터 유도된 여원 MLCA의 각 셀에서 출력되는 수열 중 비선형 수열을 출력하는 셀의 위치를 분석한다.

스토캐스틱 분자동역학 시뮬레이션을 통한 직사각형 마이크로 채널 내의 입자 확산 연구 (STOCHASTIC MOLECULAR DYNAMICS SIMULATION OF PARTICLE DIFFUSION IN RECTANGULAR MICROCHANNELS)

  • 김영록;박철우;김대중
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 학술대회
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    • pp.204-207
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    • 2008
  • Stochastic molecular dynamics simulation is a variation of standard molecular dynamics simulation that basically omits water molecules. The omission of water molecules, occupying a majority of space, enables flow simulation at microscale. This study reports our stochastic molecular dynamics simulation of particles diffusing in rectangular microchannels. We interestingly found that diffusion patterns in channels with a very small aspect ratio differ by dimensions. We will also discuss the future direction of our research toward a more realistic simulation of micromixing.

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스토캐스틱 분자동역학 시뮬레이션을 통한 직사각형 마이크로 채널 내의 입자 확산 연구 (STOCHASTIC MOLECULAR DYNAMICS SIMULATION OF PARTICLE DIFFUSION IN RECTANGULAR MICROCHANNELS)

  • 김영록;박철우;김대중
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년 추계학술대회논문집
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    • pp.204-207
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    • 2008
  • Stochastic molecular dynamics simulation is a variation of standard molecular dynamics simulation that basically omits water molecules. The omission of water molecules, occupying a majority of space, enables flow simulation at microscale. This study reports our stochastic molecular dynamics simulation of particles diffusing in rectangular microchannels. We interestingly found that diffusion patterns in channels with a very small aspect ratio differ by dimensions. We will also discuss the future direction of our research toward a more realistic simulation of micromixing.

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Effectiveness of E-Training, E-Leadership, and Work Life Balance on Employee Performance during COVID-19

  • WOLOR, Christian Wiradendi;SOLIKHAH, Solikhah;FIDHYALLAH, Nadya Fadillah;LESTARI, Deniar Puji
    • The Journal of Asian Finance, Economics and Business
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    • 제7권10호
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    • pp.443-450
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    • 2020
  • This study aims to add insight into the effectiveness of e-training, e-leadership, work-life balance, and work motivation on millennial generation employees' performance in today's work life amid the outbreak of the COVID-19 pandemic that requires to work more online. Unlike previous generations, millennials are technology-literate, intent on succeeding quickly, give up easily, and seek instantaneous gratification. The population in this study are millennial generation employees at one of Honda motorcycle dealers in Jakarta, Indonesia. The number of samples collected was 200. The sampling technique used is the side probability method, with proportional random sampling technique. The research method used is an associative quantitative approach through survey methods and Structural Equation Modeling. Data were collected through questionnaires distributed to millennial generation employees, with results then processed through the Lisrel 8.5 program. The results of this study show, first, that e-training, e-leadership, and work-life balance have positive effect on work motivation. Second, e-training, e-leadership, work-life balance, and work motivation have positive effect on employees' performance. The findings indicate that companies must pay attention to the factors of e-training, e-leadership, and work-life balance to keep employees motivated and to maintain optimal employee performance, especially during the COVID-19 pandemic through working online.

최대길이를 갖는 셀룰라 오토마타의 생성 (Generation of Maximum Length Cellular Automata)

  • 최언숙;조성진
    • 정보보호학회논문지
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    • 제14권6호
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    • pp.25-30
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    • 2004
  • 최대길이를 갖는 선형 90/150 셀룰라 오토마타(CA)가 패턴생성, 신호분석, 암호, 오류정정 부호에 응용되면서 n차 원시다항식을 특성다항식으로 갖는 선형 CA에 관한 연구가 활발하게 이루어지고 있다. 본 논문은 최대길이를 갖는 다양한 셀룰라 오토마타의 효과적인 생성방법을 제안한다. 특성다항식이 n차 원시다항식인 선형이며 최대길이를 갖는 CA(MLCA)로부터 유도된 여원 CA가 MLCA임을 밝히며 여원 MLCA의 여러 가지 성질들을 분석한다 또한 n-셀 MLCA를 ${\phi}(2^{n}-1)2^{n+1}$/n.개 생성할 수 있음을 보인다.

Longitudinal Analysis of Body Weight and Feed Intake in Selection Lines for Residual Feed Intake in Pigs

  • Cai, W.;Wu, H.;Dekkers, J.C.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권1호
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    • pp.17-27
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    • 2011
  • A selection experiment for reduced residual feed intake (RFI) in Yorkshire pigs consisted of a line selected for lower RFI (LRFI) and a random control line (CTRL). Longitudinal measurements of daily feed intake (DFI) and body weight (BW) from generation 5 of this experiment were used. The objectives of this study were to evaluate the use of random regression (RR) and nonlinear mixed models to predict DFI and BW for individual pigs, accounting for the substantial missing information that characterizes these data, and to evaluate the effect of selection for RFI on BW and DFI curves. Forty RR models with different-order polynomials of age as fixed and random effects, and with homogeneous or heterogeneous residual variance by month of age, were fitted for both DFI and BW. Based on predicted residual sum of squares (PRESS) and residual diagnostics, the quadratic polynomial RR model was identified to be best, but with heterogeneous residual variance for DFI and homogeneous residual variance for BW. Compared to the simple quadratic and linear regression models for individual pigs, these RR models decreased PRESS by 1% and 2% for DFI and by 42% and 36% for BW on boars and gilts, respectively. Given the same number of random effects as the polynomial RR models, i.e., two for BW and one for DFI, the non-linear Gompertz model predicted better than the polynomial RR models but not as good as higher order polynomial RR models. After five generations of selection for reduced RFI, the LRFI line had a lower population curve for DFI and BW than the CTRL line, especially towards the end of the growth period.

한국 침 임상시험의 질 평가 및 분석 (Assessing Methodological Quality of Acupuncture Clinical Trials of Korea)

  • 박지은;강경원;최선미
    • Journal of Acupuncture Research
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    • 제24권1호
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    • pp.127-135
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    • 2007
  • Objectives: To evaluate the methodological quality of Korean Acupuncture Clinical trials Methods : Two independent researchers reviewed 12 protocols of Acupuncture clinical trials which were conducted in Korea 2006. Also, Survey Principal Investigator of those was conducted. We compare the results of protocol review with investigator reponses of actual practice. Quality assessment consisted of 5 items including random sequence generation, randomization method, allocation concealment, subject blinding, assessor blinding. Results : Randomization was performed using the proper procedure to insure that treatment assignment is unbiased and concealed from subjects in all clinical trials, According to protocols, 6(50%) of 12 clinical trials used computer-generated random numbers, 6(50%) remaining trials didn't describe the randomization method. Also all trials used appropriate randomization methods on the basis of the survey results: 8 trials used computer-generated random number, 2 used random table. Of 7 protocols in which allocation concealment was stated, 5(71%) reported appropriate method (Calling a central office or statisticians, Sealed opaque envelopes). However according to survey, 5(42%) of 12 trials used inappropriate allocation concealment (Keeping a master randomization list and referring to when subject entered the trial). In addition, the result of protocol review and survey response was not coincident in 5(42%) trials. Subject blinding was conducted in all except 1 clinical trials. Although 11(92%) of 12 trials were conducted using assessor blinding in actual practice, only 7(58%) reported that in protocol. Conclusion : Although randomization and blinding were conducted adequately, allocation concealment was used inadequately, Not only appropriate allocation concealment, but also every quality assessment item including randomization, blinding should be stated in more detail in protocol.

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