• Title/Summary/Keyword: 마르코프 체인

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Prediction of Household Ratio by Rice Farm Scale in ChungCheongnam-province - Focused on Markov Chains and Quadratic Programming - (충청남도 논 경지규모별 농가비율 예측 -마르코프체인과 이차계획법을 중심으로-)

  • Kim, Sung-Rok
    • Journal of Agricultural Extension & Community Development
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    • v.24 no.1
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    • pp.1-8
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    • 2017
  • The Purpose of this study is to predict farm size per farming household in Chungcheongnam-province by using the Markov chains and Quadratic Programming.. The results are as follows; First, small-scale farms with less than 1.0ha of land are predicted to be still more than half (of total farming households) in 2025 as well. Second, large-scale farms with 3.0ha-5.0ha land and extra large-scale farms with over 5.0ha of land are predicted to gradually expand their proportion in total farm scale. Third, middle-scale farms with 1.0ha-3.0ha land are forecasted to be reduced in their relative proportion. It is required to take into account regional characteristics to improve the effectiveness of a rice industry policy. Therefore, this study has some significance in attempting to research on the ownership structure of rice production areas in consideration of target regions.

Failure Probability Calculation Method Using Kriging Metamodel-based Importance Sampling Method (크리깅 근사모델 기반의 중요도 추출법을 이용한 고장확률 계산 방안)

  • Lee, Seunggyu;Kim, Jae Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.5
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    • pp.381-389
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    • 2017
  • The kernel density was determined based on sampling points obtained in a Markov chain simulation and was assumed to be an important sampling function. A Kriging metamodel was constructed in more detail in the vicinity of a limit state. The failure probability was calculated based on importance sampling, which was performed for the Kriging metamodel. A pre-existing method was modified to obtain more sampling points for a kernel density in the vicinity of a limit state. A stable numerical method was proposed to find a parameter of the kernel density. To assess the completeness of the Kriging metamodel, the possibility of changes in the calculated failure probability due to the uncertainty of the Kriging metamodel was calculated.

A Bayesian Evolutionary Algorithm with Multiple Markov Chains (다중 마르코프 체인의 베이지안 진화 알고리즘)

  • 이시은;장병탁
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.322-324
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    • 2002
  • 진화 연산의 확률적 모델인 베이지안 진화 알고리즘의 수렴 특성에 대한 이전 연구를 통해 개체군 크기가 1인 경우에 대해 베이지안 진화 알고리즘을 단일 테인 MCMC로 변환하여 수렴 특성을 보였다. 본 논문에서는 개체군 크기가 1로 제한되지 않는 경우 베이지안 진화알고리즘을 다중 체 인의 개체군으로 생각하여 수렴 특성을 살펴본다.

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Probabilistic Prediction of Structural Performance for Rational Bridge Management Policy (합리적 교량유지관리 의사결정을 위한 구조성능의 추계학적 예측)

  • Oh, Byung-Hwan;Kim, Dong-Wook
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.185-193
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    • 2004
  • Reasonable prediction of bridge deterioration is the most important factor in the determination of repair time or optimized maintenance policy for bridges. To accomplish these purposes, the proposed method is composed of quantitative condition assessment, Markov chains and Bayesian estimates. Example predictions of concrete slab bridges in Korea were illustrated with higher reasonability than those of existing methods such as expert opinion and visual inspection only.

MCMC Particle Filter based Multiple Preceeding Vehicle Tracking System for Intelligent Vehicle (MCMC 기반 파티클 필터를 이용한 지능형 자동차의 다수 전방 차량 추적 시스템)

  • Choi, Baehoon;An, Jhonghyun;Cho, Minho;Kim, Euntai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.2
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    • pp.186-190
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    • 2015
  • Intelligent vehicle plans motion and navigate itself based on the surrounding environment perception. Hence, the precise environment recognition is an essential part of self-driving vehicle. There exist many vulnerable road users (e.g. vehicle, pedestrians) on vehicular driving environment, the vehicle must percept all the dynamic obstacles accurately for safety. In this paper, we propose an multiple vehicle tracking algorithm using microwave radar. Our proposed system includes various special features. First, exceptional radar measurement model for vehicle, concentrated on the corner, is described by mixture density network (MDN), and applied to particle filter weighting. Also, to conquer the curse of dimensionality of particle filter and estimate the time-varying number of multi-target states, reversible jump markov chain monte carlo (RJMCMC) is used to sampling step of the proposed algorithm. The robustness of the proposed algorithm is demonstrated through several computer simulations.

Markov Chain Monte Carlo Simulation to Estimate Material Properties of a Layered Half-space (층상 반무한 지반의 물성치 추정을 위한 마르코프 연쇄 몬테카를로 모사 기법)

  • Jin Ho Lee;Hieu Van Nguyen;Se Hyeok Lee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.3
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    • pp.203-211
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    • 2023
  • A Markov chain Monte Carlo (MCMC) simulation is proposed for probabilistic full waveform inversion (FWI) in a layered half-space. Dynamic responses on the half-space surface are estimated using the thin-layer method when a harmonic vertical force is applied. Subsequently, a posterior probability distribution function and the corresponding objective function are formulated to minimize the difference between estimations and observed data as well as that of model parameters from prior information. Based on the gradient of the objective function, a proposal distribution and an acceptance probability for MCMC samples are proposed. The proposed MCMC simulation is applied to several layered half-space examples. It is demonstrated that the proposed MCMC simulation for probabilistic FWI can estimate probabilistic material properties such as the shear-wave velocities of a layered half-space.

Changes in Spatial Distribution of Manufacturing Startup Activities in the Capital Region, Korea: A Spatial Markov Chain Approach (수도권 제조업 창업 활동의 공간적 분포 변화 - 공간 마르코프 체인의 응용 -)

  • Song, Changhyun;Ahn, Soonbeom;Lim, Up
    • Journal of the Korean Regional Science Association
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    • v.37 no.2
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    • pp.63-82
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    • 2021
  • This study aims to explore how manufacturing start-up activities from 2000 to 2018 have changed spatially and to predict changes in distribution patterns of future start-up activities. For the analysis, the Census on Establishments microdata from 2000 to 2018 were used, and the manufacturing industry was classified into four detailed industrial groups according to the 40 manufacturing standards presented by the Korea Institute for Industrial Economics and Trade's ISTANS. According to the results, start-up activities in industries that require high technology levels are concentrated in southern Gyeonggi region, and other start-up activities are concentrated outside of the metropolitan area. When the distribution change from 2018 to 2036, extending the trend from 2000 to 2018, it was confirmed that there was a high possibility of a rise in the hierarchy in the future in regions adjacent to regions where start-up activities occur. This study aimed to provide implications for regional policies related to fostering start-ups and creating jobs by dynamically analyzing the location pattern of manufacturing start-ups, which is a major source of job creation.

Two-Dimensional Model of Hidden Markov Lattice (이차원 은닉 마르코프 격자 모형)

  • 신봉기
    • Journal of Korea Multimedia Society
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    • v.3 no.6
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    • pp.566-574
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    • 2000
  • Although a numbed of variants of 2D HMM have been proposed in the literature, they are, in a word, too simple to model the variabilities of images for diverse classes of objects; they do not realize the modeling capability of the 1D HMM in 2D. Thus the author thinks they are poor substitutes for the HMM in 2D. The new model proposed in this paper is a hidden Markov lattice or, we can dare say, a 2D HMM with the causality of top-down and left-right direction. Then with the addition of a lattice constraint, the two algorithms for the evaluation of a model and the maximum likelihood estimation of model parameters are developed in the theoretical perspective. It is a more natural extension of the 1D HMM. The proposed method will provide a useful way of modeling highly variable patterns such as offline cursive characters.

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On-line Handwritten Numeral Recognition based on Table Top Display (테이블 탑 디스플레이 기반의 온라인 필기 숫자 인식)

  • Kim, Eui-Chul;Kim, Ji-Woong;Kim, Soo-Hyung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.11a
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    • pp.9-12
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    • 2007
  • 테이블 탑 디스플레이는 사람에게 친숙한 상호작용의 매개체인 손을 입력장치로 이용하는 일종의 탁자형 멀티 터치스크린이라고 할 수 있다. 본 논문에서는 이러한 환경에서 손가락 제스쳐를 활용하여 필기 숫자를 인식하는 연구를 수행함으로써 테이블 탑 디스플레이에 적합한 필기 숫자 인식 기술을 개발하였고, 이로 인해 추후 진행될 연속 숫자 혹은 특수기호의 성공적인 인식 가능성을 확인하였다. 실험 과정은 테이블 탑 디스플레이의 표면을 통해 입력된 손가락 궤적을 잡음제거, 대표점 추출등의 전처리 과정을 거쳐 16-방향 체인코드로 변환하고, 변환된 체인코드의 학습 및 필기 숫자 인식에 확률 통계적 모델인 은닉 마르코프 모델을 이용하였다. 학습에는 총 300개 필기 숫자 데이터를 이용하였고, 인식 실험에 사용한 별도의 100개의 필기 숫자 데이터에 대해 97%의 정인식율을 보였다.

User Independent On-line Handwritten Numeral Recognition in Table Top Display (테이블 탑 디스플레이에서 사용자 독립적인 온라인 필기 숫자 인식)

  • Kim, Ji-Woong;Kim, Eui-Chul;Kim, Soo-Hyung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.05a
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    • pp.182-185
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    • 2008
  • 테이블 탑 디스플레이는 사람에게 친숙한 상호작용의 수단인 손을 인터페이스 수단으로 이용하는 일종의 탁자형 터치스크린이다. 본 논문에서는 이러한 환경에서 사용자 독립적인 온라인 필기 숫자를 인식하는 연구를 수행하였다. 이로 인해 추후 진행될 다중 사용자의 한글, 영문, 특수기호의 인식 가능성을 확인하였다. 실험 과정은 테이블 탑 디스플레이의 표면을 통해 입력된 사용자별 손가락 궤적으로 기준점을 잡고, 각 사용자별 필기궤적에서 대표점 추출과 16-방향 체인코드변환을 수행하였다, 변환된 체인코드의 학습 및 필기숫자 인식에 확률 통계적 모델인 은닉 마르코프 모델을 이용하였다. 실험에 사용된 데이터는 총 300개의 데이터를 사용 하였고, 학습은 10회 복제하여 총 3000개의 데이터로 수행하였다. 각 사용자별 데이터를 100개씩 인식 실험에 사용하여 각각 93%, 94%의 정인식율을 보였다.