• Title/Summary/Keyword: Distribution Approach

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Study of Integrated Production-Distribution Planning Using Simulation and Genetic Algorithm in Supply Chain Network (공급사슬네트워크에서 시뮬레이션과 유전알고리즘을 이용한 통합생산분배계획에 대한 연구)

  • Lim, Seok-Jin
    • Journal of the Korea Safety Management & Science
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    • v.22 no.4
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    • pp.65-74
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    • 2020
  • Many of companies have made significant improvements for globalization and competitive business environment The supply chain management has received many attentions in the area of that business environment. The purpose of this study is to generate realistic production and distribution planning in the supply chain network. The planning model determines the best schedule using operation sequences and routing to deliver. To solve the problem a hybrid approach involving a genetic algorithm (GA) and computer simulation is proposed. This proposed approach is for: (1) selecting the best machine for each operation, (2) deciding the sequence of operation to product and route to deliver, and (3) minimizing the completion time for each order. This study developed mathematical model for production, distribution, production-distribution and proposed GA-Simulation solution procedure. The results of computational experiments for a simple example of the supply chain network are given and discussed to validate the proposed approach. It has been shown that the hybrid approach is powerful for complex production and distribution planning in the manufacturing supply chain network. The proposed approach can be used to generate realistic production and distribution planning considering stochastic natures in the actual supply chain and support decision making for companies.

Simulation-Based Operational Risk Assessment (시뮬레이션 기법을 이용한 운영리스크 평가)

  • Hwang, Myung-Soo;Lee, Young-Jai
    • Journal of Information Technology Services
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    • v.4 no.1
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    • pp.129-139
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    • 2005
  • This paper proposes a framework of Operational Risk-based Business Continuity System(ORBCS), and develops protection system for operational risk through operational risk assessment and loss distribution approach based on risk management guideline announced in the basel II. In order to find out financial operational risk, business processes of domestic bank are assorted by seven event factors and eight business activities so that we can construct the system. After we find out KRI(Key Risk Indicator) index, tasks and risks, we calculated risk possibility and expected cost by analyzing quantitative data, questionnaire and qualitative approach for AHP model from the past events. Furthermore, we can assume unexpected cost loss by using loss distribution approach presented in the basel II. Each bank can also assume expected loss distributions of operational risk by seven event factors and eight business activities. In this research, we choose loss distribution approach so that we can calculate operational risk. In order to explain number of case happened, we choose poisson distribution, log-normal distribution for loss cost, and estimate model for Monte-Carlo simulation. Through this process which is measured by operational risk. of ABC bank, we find out that loss distribution approach explains closer unexpected cost directly compared than internal measurement approach, and makes less unexpected cost loss.

Bulk-Type Cloud Microphysics Parameterization in Atmospheric Models (대기 모형에서의 벌크형 미세구름물리 모수화 방안)

  • Lim, Kyo-Sun Sunny
    • Atmosphere
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    • v.29 no.2
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    • pp.227-239
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    • 2019
  • This paper reviews various bulk-type cloud microphysics parameterizations (BCMPs). BCMP, predicting the moments of size distribution of hydrometeors, parameterizes the grid-resolved cloud and precipitation processes in atmospheric models. The generalized gamma distribution is mainly applied to represent the hydrometeors size distribution in BCMPs. BCMP can be divided in three different methods such as single-moment, double-moment, and triple-moment approaches depending on the number of prognostic variables. Single-moment approach only predicts the hydrometeors mixing ratio. Double-moment approach predicts not only the hydrometeors mixing ratio but also the hydrometeors number concentration. Triple-moment approach predicts the dispersion parameter of hydrometeors size distribution through the prognostic reflectivity, together with the number concentrations and mixing ratios of hydrometeors. Triple-moment approach is the most time expensive method because it has the most number of prognostic variables. However, this approach can allow more flexibility in representing hydrometeors size distribution relative to single-moment and double-moment approaches. At the early stage of the development of BMCPs, warm rain processes were only included. Ice-phase categories such as cloud ice, snow, graupel, and hail were included in BCMPs with prescribed properties for densities and sedimentation velocities of ice-phase hydrometeors since 1980s. Recently, to avoid fixed properties for ice-phase hydrometeors and ad-hoc category conversion, the new approach was proposed in which rimed ice and deposition ice mixing ratios are predicted with total ice number concentration and volume.

Hazard Rate Estimation from Bayesian Approach (베이지안 확률 모형을 이용한 위험률 함수의 추론)

  • Kim, Hyun-Mook;Ahn, Seon-Eung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.3
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    • pp.26-35
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    • 2005
  • This paper is intended to compare the hazard rate estimations from Bayesian approach and maximum likelihood estimate(MLE) method. Hazard rate frequently involves unknown parameters and it is common that those parameters are estimated from observed data by using MLE method. Such estimated parameters are appropriate as long as there are sufficient data. Due to various reasons, however, we frequently cannot obtain sufficient data so that the result of MLE method may be unreliable. In order to resolve such a problem we need to rely on the judgement about the unknown parameters. We do this by adopting the Bayesian approach. The first one is to use a predictive distribution and the second one is a method called Bayesian estimate. In addition, in the Bayesian approach, the prior distribution has a critical effect on the result of analysis, so we introduce the method using computerized-simulation to elicit an effective prior distribution. For the simplicity, we use exponential and gamma distributions as a likelihood distribution and its natural conjugate prior distribution, respectively. Finally, numerical examples are given to illustrate the potential benefits of the Bayesian approach.

Reliability Demonstration Test for a Finite Population Based on the Conjugacy of the Beta-Binomial Distribution (베타-이항분포의 공액성을 근거로 한 유한 모집단의 신뢰성 입증 시험)

  • Jeon, Jong-Seon;Ahn, Sun-Eung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.2
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    • pp.98-105
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    • 2012
  • This paper describes the Bayesian approach for reliability demonstration test based on the samples from a finite population. The Bayesian approach involves the technical method about how to combine the prior distribution and the likelihood function to produce the posterior distribution. In this paper, the hypergeometric distribution is adopted as a likelihood function for a finite population. The conjugacy of the beta-binomial distribution and the hypergeometric distribution is shown and is used to make a decision about whether to accept or reject the finite population judging from a viewpoint of faulty goods. A numerical example is also given.

Operational Risk Measurement of Financial Institutions via AHP (AHP 분석을 이용한 금융기관 운영리스크 측정)

  • Choi, Seung-Il
    • Korean Management Science Review
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    • v.28 no.3
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    • pp.73-82
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    • 2011
  • Basel II advanced measurement approaches for operational risk need to estimate the frequency and severity distribution of operational losses. Due to lack of internal loss data, the estimation is impossible in many cases and so external loss data might be used by scaling on asset or gross income. To get around lack of loss data, scenario analysis combined with loss distribution approach can be useful in calculating the capital charge of operational risk. However, scenario based loss distribution approach requires much time and effort. Instead we may apply the analytic hierarchy process to measure operational risk of financial institutions. The analytic hierarchy process combined with loss distribution approach is to estimate the capital charge of operational risk in other areas based on the operational VaR in an area with sufficient loss data. AHP provides a tool for timely measurement of operational risk in this rapidly changing global environment.

Distribution System and the Environment (환경과 유통시스템)

  • Sejo Oh;Lim, Young-Kyun
    • Proceedings of the Korean DIstribution Association Conference
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    • 2000.10a
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    • pp.183-185
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    • 2000
  • A proactive approach on environmental issues may be one of critical competitive factors for global business in near future. Especially, distribution systems are very related to the various environmental issues, including development of green products and packaging, selection of the transportation vehicles and pallets, design of retail stores and distribution facilities, participation for solving the local environmental problems, and so on. In order to approach the environmental issues on distribution systems, for the first time managers need to understand the strategic framework for green management and then, to find the key success factors of leading companies in this field. Finally, future directions of strategic green management on distribution systems are discussed and shared.

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A Study of Cold Chain Logistics in China: Hybrid Genetic Algorithm Approach (중국 콜드체인 물류에 관한 연구: 혼합유전알고리즘 접근법)

  • Chen, Xing;Jang, Eun-Mi
    • Journal of Korea Society of Industrial Information Systems
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    • v.25 no.6
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    • pp.159-169
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    • 2020
  • A cold chain logistics (CCL) model for chilled food (-1℃ to 8℃) distributed in China was developed in this study. The CCL model consists of a distribution center (DC) and distribution target points (DT). The objective function of the CCL model is to minimize the total distribution routes of all distributors. To find the optimal result of the objective function, the hybrid genetic algorithm (HGA) approach is proposed. The HGA approach was constructed by combining the improved K-means and genetic algorithm (GA) approaches. In the case study, three scenarios were considered for the CCL model based on the distribution routes and the available distance, and they were solved using the proposed HGA approach. Analysis results showed that the distribution costs and mileage were reduced by approximately 19%, 20% and 16% when the proposed HGA approach was used.

Effect of Task-Oriented Approach on Weight-Bearing Distribution and Muscular Activities of the Paretic Leg During Sit-to-Stand Movement in Chronic Stroke Patients (과제지향적 접근법이 만성 뇌졸중 환자의 일어서기 동작 시 환측다리의 체중지지비율과 근활성도에 미치는 영향)

  • Kim, Won-Ho
    • Physical Therapy Korea
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    • v.18 no.2
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    • pp.18-26
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    • 2011
  • The purpose of this study was to investigate the effects of a task-oriented approach on weight-bearing distribution and muscular activities of the paretic leg during sit-to-stand movement in 18 chronic stroke patients. Both groups were received neurodevelopmental treatment for 30 min/day and then the experimental group ($n_1$=9) followed additional a task-oriented approach (sit-to stand training with controlled environment) and the control group ($n_2$=9) followed a passive range of motion exercise for 15 min/day, five days/week, for four weeks. Weight-bearing distribution and muscular activities of the paretic leg during sit-to-stand movement were measured before and after four weeks of training. There was significantly improved weight-bearing distribution of the paretic leg during sit-to-stand movement in the experimental group compared with that of the control group after four weeks of training (p<.05). But electromyographic activities of the quadriceps and the tibialis anterior of the paretic leg were not significantly different (p>.05). Thus, it is necessary to apply a task-oriented approach to improve the weight-bearing distribution of the paretic leg during sit-to-stand movement in chronic stroke patients.

A Novel Statistical Feature Selection Approach for Text Categorization

  • Fattah, Mohamed Abdel
    • Journal of Information Processing Systems
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    • v.13 no.5
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    • pp.1397-1409
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    • 2017
  • For text categorization task, distinctive text features selection is important due to feature space high dimensionality. It is important to decrease the feature space dimension to decrease processing time and increase accuracy. In the current study, for text categorization task, we introduce a novel statistical feature selection approach. This approach measures the term distribution in all collection documents, the term distribution in a certain category and the term distribution in a certain class relative to other classes. The proposed method results show its superiority over the traditional feature selection methods.