• Title/Summary/Keyword: Inventory-Allocation

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A Study on Deterministic Utilization of Facilities for Allocation in the Semiconductor Manufacturing (반도체 설비의 효율성 제고를 위한 설비 할당 스케줄링 규칙에 관한 연구)

  • Kim, Jeong Woo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.153-161
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    • 2016
  • Semiconductor manufacturing has suffered from the complex process behavior of the technology oriented control in the production line. While the technological processes are in charge of the quality and the yield of the product, the operational management is also critical for the productivity of the manufacturing line. The fabrication line in the semiconductor manufacturing is considered as the most complex part because of various kinds of the equipment, re-entrant process routing and various product devices. The efficiency and the productivity of the fabrication line may give a significant impact on the subsequent processes such as the probe line, the assembly line and final test line. In the management of the re-entrant process such as semiconductor fabrication, it is important to keep balanced fabrication line. The Performance measures in the fabrication line are throughput, cycle time, inventory, shortage, etc. In the fabrication, throughput and cycle time are the conflicting performance measures. It is very difficult to achieve two conflicting goal simultaneously in the manufacturing line. The capacity of equipment is important factor in the production planning and scheduling. The production planning consideration of capacity can make the scheduling more realistic. In this paper, an input and scheduling rule are to achieve the balanced operation in semiconductor fabrication line through equipment capacity and workload are proposed and evaluated. New backward projection and scheduling rule consideration of facility capacity are suggested. Scheduling wafers on the appropriate facilities are controlled by available capacity, which are determined by the workload in terms of the meet the production target.

Strategies and Plans of Official Development Assistance (ODA) for Tajikistan in the Forest Sector (타지키스탄 대상 산림 부문 공적개발원조 (ODA) 사업의 추진 전략과 방안)

  • An, Jiae;Chang, Hanna;Kim, Jusub;Han, Seung Hyun;Son, Yowhan
    • Journal of Climate Change Research
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    • v.9 no.3
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    • pp.263-271
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    • 2018
  • Considering the high needs of recipient countries and the regional biases of Korean Official Development Assistance (ODA) policy, increases in the total amount of ODA and allocation to the forest sector are needed for Central Asia. In Tajikistan, illegal harvesting and grazing cause a gradual decrease in forest area. The Tajikistan government conserves forests by requesting international cooperation and establishing a policy for sustainable management of forest resources and prevention of further damages. To suggest suitable strategies and plans, the current statuses of forests and forestry were investigated, and ODA projects that can illustrate successful Korean experiences of forestation were conceived based on various geographical features and local conditions of Tajikistan in this study. Forest resource creation type projects (fuelwood and Tugai forest restoration) could result in energy independence and enhancement of ecosystem service such as a climate regulation and an increase in biodiversity. Community development type projects (introduction of ecotourism, agroforestry, and planting of fruit trees) can contribute to job creation and encourage participation of local residents, thus improving their incomes. In addition, establishment of a project foundation, including education, training, and a national forest inventory, would help those projects be sustainable in the long-term.

Topic Modeling Analysis Comparison for Research Topic in Korean Society of Industrial and Systems Engineering: Concentrated on Research Papers from 1978~1999 (한국산업경영시스템학회지 연구 주제의 토픽모델링 분석 비교: 1978년~99년 논문을 중심으로)

  • Park, Dong Joon;Oh, Hyung Sool;Kim, Ho Gyun;Yoon, Min
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.44 no.4
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    • pp.113-127
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    • 2021
  • Topic modeling has been receiving much attention in academic disciplines in recent years. Topic modeling is one of the applications in machine learning and natural language processing. It is a statistical modeling procedure to discover topics in the collection of documents. Recently, there have been many attempts to find out topics in diverse fields of academic research. Although the first Department of Industrial Engineering (I.E.) was established in Hanyang university in 1958, Korean Institute of Industrial Engineers (KIIE) which is truly the most academic society was first founded to contribute to research for I.E. and promote industrial techniques in 1974. Korean Society of Industrial and Systems Engineering (KSIE) was established four years later. However, the research topics for KSIE journal have not been deeply examined up until now. Using topic modeling algorithms, we cautiously aim to detect the research topics of KSIE journal for the first half of the society history, from 1978 to 1999. We made use of titles and abstracts in research papers to find out topics in KSIE journal by conducting four algorithms, LSA, HDP, LDA, and LDA Mallet. Topic analysis results obtained by the algorithms were compared. We tried to show the whole procedure of topic analysis in detail for further practical use in future. We employed visualization techniques by using analysis result obtained from LDA. As a result of thorough analysis of topic modeling, eight major research topics were discovered including Production/Logistics/Inventory, Reliability, Quality, Probability/Statistics, Management Engineering/Industry, Engineering Economy, Human Factor/Safety/Computer/Information Technology, and Heuristics/Optimization.

Moxibustion for Knee Osteoarthritis : A Protocol for a Pilot Randomized Controlled Trial (슬관절염에 대한 뜸 치료의 유효성 및 안전성 연구 : 무작위 대조 예비 임상연구 프로토콜)

  • Lee, Seung-Hoon;Kim, Kun-Hyung;Kim, Tae-Hun;Kim, Jung-Eun;Kim, Joo-Hee;Kang, Kyung-Won;Jung, So-Young;Kim, Ae-Ran;Park, Hyo-Ju;Shin, Mi-Suk;Hong, Kwon-Eui;Choi, Sun-Mi
    • Korean Journal of Acupuncture
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    • v.28 no.4
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    • pp.1-15
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    • 2011
  • Objectives : The purpose of this study is to evaluate the feasibility of massive clinical research and to make a basic analysis on the effectiveness and safety of moxibustion treatment on knee osteoarthritis compared to usual care. Methods and Results : This study is a protocol for a pilot randomized controlled trial. Forty participants are assigned to the moxibustion group (n=20) and usual care group (n=20). Participants assigned to the moxibustion group receive moxibustion treatment on the affected knee(s) at six standard acupuncture points (ST36, ST35, ST34, SP9, Ex-LE04 and SP10) three times per week for four weeks (total of 12 sessions). Participants in the usual care group don't receive moxibustion treatment during the study period and follow-up are made on the 5th, 9th and 13th weeks after random allocation. Both groups are allowed to use any kind of treatment, including surgery, conventional medication, physical treatment, acupuncture, herbal medicine, over-the-counter drugs and other active treatments. Education material that explains knee osteoarthritis and current management options and self-exercise is provided for each group. The pain scale of the Korean Western Ontario and McMaster Universities Questionnaire (K-WOMAC) is the primary outcome measurement used in this study. Other subscales of the K-WOMAC, the Short-Form 36 Health Survey (SF-36), Beck Depression Inventory (BDI), Physical Function test, Patient Global Assessment, and Pain Numeric Rating Scale (NRS) are used as outcome variables to evaluate the effectiveness of acupuncture. Safety is assessed at every visit. Conclusions : The result of this trial will provide a basis for the effectiveness and safety of acupuncture treatment for knee osteoarthritis.

Effect of Pulsed Electromagnetic Field Treatment on Alleviation of Lumbar Myalgia; A Single Center, Randomized, Double-blind, Sham-controlled Pilot Trial Study

  • Park, Won-Hyung;Sun, Seung-Ho;Lee, Sun-Gu;Kang, Byoung-Kab;Lee, Jong-Soo;Hwang, Do-Guwn;Cha, Yun-Yeop
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.161-169
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    • 2014
  • The aim of this study is to investigate the efficacy of pulsed electromagnetic field (PEMF) on the alleviation of lumbar myalgia. This is a randomized, real-sham, double blind pilot study. 38 patients were divided into the PEMF group and the Sham group, each of which was composed of 19 patients (1 patient dropped out in the Sham group) of randomized allocation. The PEMF group was treated by using the PEMF device and the Sham group by using a sham device on the lumbar muscle and acupuncture points, three times a week for a total of two weeks. Evaluations of Visual Analogue Scale for bothersomeness (VASB), Visual Analogue Scale for pain intensity (VASP), Oswestry Disability Index (ODI), 36-Item Short Form Health Survey Instrument (SF-36), EuroQol-5Dimension (EQ-5D), Beck's Depression Inventory (BDI) and Roland-Morris Disability Questionnaire (RMDQ), etc. before and 1 week after treatment were carried out. The primary outcome measure was the VASB, measured 1 week after the end of the pulsed electromagnetic therapy. VASB scores for the PEMF group changed by $-2.06{\pm}2.12$ from the baseline, and that for the Sham group changed by $-0.52{\pm}0.82$ (p < 0.05). VASP scores for the PEMF group were reduced by $-2.10{\pm}2.12$ from the base line, and that for the Sham group was reduced by $-0.53{\pm}1.50$ (p < 0.05). PEMF group showed significant improvements in all VASB, VASP, ODI, SF-36, EQ-5D, BDI and RMDQ scores, while the Sham group showed significant improvements in all scores, except the VASP score. However, the VASB, VASP and RMDQ scores of the PEMF group were much lower than those of the Sham group. The two groups showed no significant difference in ODI, SF-36, EQ-5D and BDI. This study demonstrates the effectiveness of PEMF treatment for alleviating lumbar myalgia.

Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.131-145
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    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.