• 제목/요약/키워드: Flow Shop

검색결과 158건 처리시간 0.023초

유연가공 및 조립시스템에서의 AGV 운용전략 (A strategic operating model of AGVs in a flexible machining and assembly system)

  • 양대용;정병희;윤창원
    • 경영과학
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    • 제11권1호
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    • pp.23-37
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    • 1994
  • This paper discusses the methodology for the operational performance of unit-load automated guided vehicles(AGVs) in a flow-shop-type flexible machining and assembly systems (FM/AS). Throughout the paper, AGVs are working as a carrier and mobile workstation. For a double-loop FM/AS, in which one loop is dedicated to machining and the other to assembly, three AGV operating strategies are proposed. Considering the entering interval and travel time of AGVs between workcenters, the strategies are developed to determine the best job sequence which minimizes the makespan and vehicle idle time. Entering times of AGVs and the required minimum number of AGVs are obtained on the basis of the best job sequence. When the number of AGVs are limited, entering times of AGVs are adjusted to maximize the utilization of AGVs.

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아웃소싱 전략을 활용하는 두 단계 흐름생산라인에서 완료시간의 총합을 최소화하는 일정계획문제 (Minimizing Total Completion Times in a Two-machine Flowshop Scheduling with Outsourcing Strategy allowed)

  • 유재욱;이익선
    • 경영과학
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    • 제33권2호
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    • pp.1-10
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    • 2016
  • We treats a job scheduling in a 2-machine flow-shop problem with outsourcing strategy allowed. Jobs in the first machine are processed in-house or outsourced to the other companies. In this paper, all the considered jobs are determined to be in-house processed or outsourced. When a job is outsourced, then the firm should pay an outsourcing cost additionally. We want to minimize the sum of the outsourcing costs and the total completion times of finished jobs. In this paper, some solution properties are characterized, and then some heuristic algorithms and a branch-and-bound solution algorithm are derived. This paper evaluates finally the performance of the proposed algorithms during the numerical tests.

다수의 경쟁이 존재하는 환경에서 적시 스케줄링에 관한 연구 (Just-in-time Scheduling with Multiple Competing Agents)

  • 정대영;최병천
    • 한국경영과학회지
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    • 제37권1호
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    • pp.19-28
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    • 2012
  • We consider a multi-agent scheduling problem such that each agent tries to maximize the weighted number of just-in-time jobs. Two objectives are considered : the first is to find the optimal solution for one agent with constraints on the other agents' weight functions, and the second is to find the largest set of efficient schedules of which corresponding objective vectors are different for the case with identical weights. We show that when the number of agents is fixed, the single machine case with the first objective is NP-hard in the ordinary sense, and present the polynomial- time algorithm for the two-machine flow shop case with the second objective and identical weights.

유연생산시스템의 기계와 AGV의 동적 작업배정규칙 비교연구 (A Comparative Study of Dynamic Dispatching Rule for Machine and AGV of Flexible Manufacturing System)

  • 이성우
    • 한국산업융합학회 논문집
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    • 제12권1호
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    • pp.19-25
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    • 2009
  • We suggest and evaluate a dynamic scheduling rule of machines and material handling systems for on-line operation in job shop type Flexible Manufacturing System. Alternating status should be able to take operation scheduling procedures and without delay in dynamic industrial environments effectively. The interaction(SPT-NS, SPT-QSNS, SPT-NUJ, EDD-NS, EDD-QSNS, EDD-NUJ, CR-NS, CR-QSNS, CR-NUJ) between machine operation scheduling and AGV dispatching rule were also studied in this research. The performance evaluation which was obtained from DSS compares the performance of Flow time, and Empty to loaded travel ratio. It is Compared with the best rules & two system.

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공정계획을 위한 분산객체의 응용 (Application of Distributed Objects for CAPP)

  • 김준국;이홍희
    • 대한안전경영과학회지
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    • 제4권2호
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    • pp.155-168
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    • 2002
  • As the market and the organizations of an enterprise expand globally, the rapid and accurate communication gets more important for product manufacturing. The manufacturing information flow among the designers, the process planners and the shop floors is characterized and modelled. Its methods are constructed using distributed objects. Their introduction to the network-based CAPP system offers speed and safety for the system and makes the reconstruction and distribution of the application programs easy. The manufacturing processes are generated based on the feature information of a designed part, then the manufacturing resources are selected using the process planning logic which is implemented by distributed objects. The databases and distributed objects are integrated under the recent internet environments. The developed system makes it possible to manipulate and to transfer the process planning and manufacturing data everywhere in the world.

현장상황을 고려한 회전현상 부품의 공정계획 시스템 구축과 운영에 관한 연구 (A Study on Computer Aided Process Planning System for Rotational Parts Considering Shop Floor Status)

  • 전성범;박남규;신기태;김기동;박진우
    • 산업공학
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    • 제7권3호
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    • pp.125-135
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    • 1994
  • This thesis reports the development of a Computer-Aided Process Planning system for rotational parts. The developed system ultimately generates process plans for rotational parts through a knowledge-base. The knowledge-base and decision-making algorithms are represented by Pascal computer programming language. We have developed a process planning system which adjusts the sequence of processes by itself to ensure the quality of the parts. This system generates more detailed job sequence and descriptions than other well-known process planning systems. We present realistic and efficient process plans through the integration of process planning and scheduling. This system optimizes flow time of parts by decreasing the number of machine set-ups.

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Lung Function of Grain Millers Exposed to Grain Dust and Diesel Exhaust in Two Food Markets in Ibadan Metropolis, Nigeria

  • Iyogun, Kemi;Lateef, Suraju A.;Ana, Godson R.E.E.
    • Safety and Health at Work
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    • 제10권1호
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    • pp.47-53
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    • 2019
  • Background: Despite growing concern over occupational exposure to particulate matter (PM) such as grain dust and diesel exhaust, information about the exposure level and health implications among workers in small-scale milling enterprises in developing countries like Nigeria has not been adequately documented. The purpose of this study was to assess the level of exposure to grain dust and diesel exhaust and effect on lung function among grain millers in food markets in Ibadan metropolis, Nigeria. Methods: The study adopted descriptive cross-sectional design with a comparative approach. Sixteen grain milling shops each were randomly selected from two major food markets in Ibadan metropolis for indoor $PM_{10}$ and $PM_{2.5}$ monitoring. Seventy-two respondents each were proportionately selected from grain millers and shop owners for forced expiratory volume in one second and peak expiratory flow rate tests. Results: The $PM_{2.5}$ concentrations for both market locations ranged between 1,269.3 and $651.7{\mu}g/m^3$, while $PM_{10}$ concentrations were between 1,048.2 and $818.1{\mu}g/m^3$. The recorded concentrations exceeded the World Health Organization guideline limit of $50{\mu}g/m^3$ and $25{\mu}g/m^3$ for $PM_{2.5}$ and $PM_{10}$, respectively. As compared with control group (2.1 L), significantly lower forced expiratory volume in one second value (1.61 L) was observed among the exposed group (p < 0.05). Likewise, significantly lower peak expiratory flow rate value (186.7 L/min) was recorded among the exposed group than the control group (269.51 L/min) (p < 0.05). Conclusion: Exposure to grain dust and diesel exhaust accentuated respiratory disorders with declines in lung functions amongst grain millers. Improved milling practices and engaging cleaner milling facilities should be adopted to minimize exposure and related hazards.

흐름라인 방식의 철도차량 의장공장에서 비용을 고려한 운영전략 비교 (Comparison of Operation Strategies Considering Costs in a Railway Vehicle Assembly Shop with Flow Line Layout)

  • 김동옥;신양우;문덕희
    • 한국시뮬레이션학회논문지
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    • 제31권3호
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    • pp.23-34
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    • 2022
  • 철도차량은 제품의 특성상 일정한 수량의 차량이 결합되어 편성이 구성되며, 프로젝트는 복수의 편성을 고객에게 납품하는 것으로 계약이 이뤄지는데 만일 납기를 지키지 못하면 생산자가 지체보상금을 고객에게 지불해야 한다. 이 논문에서는 부품의 결품이 발생하는 상황에서 흐름라인 방식으로 운영되는 철도차량 의장공장의 운영전략에 대해 시뮬레이션을 이용하여 분석한다. 만일 부품의 결품이 발생한다면 조립공정의 특성상 후속 조립공정이 진행될 수 없다. 따라서 이 문제를 해결하기 위해 부품의 결품이 발생했을 때 조립작업을 수행하는 3가지 전략을 제시하였고, 인건비와 지체보상금을 합한 총 비용이 전략에 따라 어떻게 변화되는지 비교하였다.

관공호텔 조리직무의 분업과 통합에 따른 문제점과 개선방안에 관한 연구 (A Study on Effective Management & Administration System for Deluxe Hotel Kitchen in Seoul Area.)

  • 라영선
    • 한국조리학회지
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    • 제1권
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    • pp.57-89
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    • 1995
  • Despite prologed business stagnation of both international and domestic economy, hotel business as well as tourist industry has continuously been keeping growing, owing to increase of surplus income and world flowing population. During recent 4 years, growth rate of yearly mean in domestic hotels reached 9.9% and especially that of the superior class hotels 15.2%. In the composition of domestic tourist hotel's revenue, the earnings of guest rooms form 37.4%, on the other hand those of food & beverage 39.9%. This result is that our hotel business is concentrated on its interest in FOOD & BEVERAGE of which productivity per unit dimension can be increased to an unlimited extent and extent and superior class hotels strengthened in F&B are increasing in comparison with European or American hotels which are focused on guest rooms in their management. For value added rate of F&B is low as compared with increase of their earnings, they are interested in the management techniques which focus on rising the rate. As for the cost of Food & Beverage, personnel expenditure forms 36.5% and the direct materials 31.5%. Therefore how to manage personnel and materials costs which compose as much as 68% of total revenue will greatly affect net profit. We can say that an effective management technique in cost of Food & Beverage is one of the most important know-hows in hotel management. Especially management know-how for the Kitchen Department where the most of foods come out makes a great effects on various expenses, productivity and it is the achievement from hotel management. For the most of the hotel's top managers, they don't seriously take the fact that KITCHEN SYSTEM affects greatly total expenditure. This study starts from the point of recognizing the question of fundamental cause affecting tow largest cost elements incurred in Food & Beverage and trying to present an effective kitchen system. To settle the questions raised, I compared and analyzed productivity and cost of food & beverage and unit kitchen centered around superior class hotels in Seoul, which vary in Kitchen Systems. In order to attain the aforementioned study effectively purpose of this study, I compared Room-Service and Coffee-Shop Menu, flow of basic food in the kitchen, extent and result of division of labor and integration in the kitchen, scale of outlet kitchen, productivity, the turnover rate of food in store, food cost rate one another which all vary in Kitchen Systems. All these elements are compared and analyzed each other being divided into two main groups such as①. Main Production kitchen and Banquet Kitchen, and ②. coffee-shop kitchen and Room-service Kitchen. Therefore this study is to point out the problems in managing kitchens of superior class hotels which are different in systems. An effort was made to find out the better Kitchen System for superior deluxe hotels. I emphasize the followings on the proper scale of division of labor and integration of unit kitchen and a disposition plan for outlet kitchens of restaurant. First, KITCHEN SYSTEM as a sub-system of Hotel Management System is composed of sub-systems of outlet unit kitchen. Basic food materials are cooked and served for the guests while support kitchen and out restaurant kitchen interact organically each other. So Kitchen should be considered as a system composed of integrated sub-systems. Second, support and banquet kitchens should be integrated to be managed. And these unit kitchens have to be designed to be placed in the back of banquet rooms area. Third, coffee-shop kitchen and room-service kitchen should be integrated to be managed. Fourth, several unit business kitchens should be place on the same floor. Fifth, main production kitchens ought to be located near the loading duck, food store and large refrigerator. Sixth, considering the limits of supervision, duties should be adjusted as 12-20 cooks in two shifts a day for a sub-kitchen, and 18-30 cooks in three shifts a day so that labor division can be made. Last, I would like to two points for direction and task of future study. Firstly, I compare the effective income and increasing costs each other, which are incurred by increasing the use rate of the second processing materials for foods perched outside and through the results. I can find out the better points of the processing production and circulation system, and then I study this effects made on hotel kitchen system. Secondly, I can point out that more efficient kitchen system shall be established through comparing and analyzing the matter of amount of indirect costs and flow of food in different kitchen systems.

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마케팅자극과 충동구매행동 간의 관계에서 플로우의 매개효과에 관한 연구: 자기행동통제와 감각추구성향의 조절효과 (A Study on the Mediating Effect of FLOW between Marketing Stimulation and Impulsive Buying Behavior : The Moderating Role of Self Behavior Control and Sensation Seeking Tendency)

  • 오종철;권홍규;홍상진
    • 한국산학기술학회논문지
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    • 제11권1호
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    • pp.278-286
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    • 2010
  • 본 연구는 새로운 유통환경인 인터넷환경에서 디지털 콘텐츠의 충동구매에서의 마케팅 자극, 플로우, 자기행동통제 및 감각추구성향간의 영향을 살펴보고자 하였다. 이를 위해 충동구매 동기요인을 기존의 연구들에서 제시된 마케팅자극을 이용하였다. 구매자의 마케팅자극으로 디지털 콘텐츠 구매자들이 받게 되는 제품자극, 가격자극, 촉진자극으로 구분하여 구매자의 충동구매행동에 미치는 영향을 검증하였다. 이때 구매행위 전에 자신이 받은 자극에 대해 플로우를 경험하는 과정이 나타날 것이다. 플로우(FLOW)는 구매행위자가 받은 자극을 보다 강화시키는 충동구매행위의 중요한 요소가 될 것이다. 이처럼 인터넷 환경에서는 기존의 충동구매 과정과는 달리 충동구매자극 이후에 더 많은 정보를 획득할 수 있고 쉽고 빠르게 구매할 수 있기 때문에 마케팅자극이외에 구매자의 심리적인 측면이나 성향등이 충동구매행동에 있어 보다 중요한 역할을 하게 될 것이다. 행위에 대한 자신의 능력 및 통제 가능성인 자기행동 통제에 따라서 충동구매행동이 다르게 나타나게 될 것이다. 또한 구매자들이 가지고 있는 구매자들의 성향 중에 감각 추구성향은 충동구매를 하는데 조절역할을 하는지에 대한 검증을 하였다. 이를 통해 디지털 콘텐츠 충동구매와 관련된 학문적인 시사점과 더불어 디지털 콘텐츠 마케터들의 효과적인 마케팅 전략수립에 도움을 주고자 한다.