• Title/Summary/Keyword: lot-size

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Dynamic lot-size model allowing lost sales

  • 함주호;김승한
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 1994년도 추계학술발표회 발표논문집; 연세대학교경영관, 서울; 8 Oct. 1994
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    • pp.73-73
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    • 1994
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귀촌형 공동체마을 조성을 위한 생활환경과 사회환경 측면의 가이드라인 개발 (Guidelines Development of Living and Social Environmental Aspects for the Planning of Back-to-Farm Community Village)

  • 박경옥;이상운;정지인
    • 한국농촌건축학회논문집
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    • 제20권1호
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    • pp.1-10
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    • 2018
  • In order to give back-to-farm residents the stable settlement environment in the rural area, the 'community village' is desirable as the village type and its village planning guideline should be supported as well. The purpose of this study was to develop a guideline for the planning of back-to-farm community village in the living and social environmental aspects, based on the comprehensive comparative analysis about items that field survey and literature suggested. The guideline for the living environment was developed for 6 items; village structure(adequate size, lot, outer space for household), village landscape(allocation, space composition), road system and transportation(parking lot in village, placement of bus stops, village trail, public transportation, road and pedestrian system), common living facilities and common space(number, size, location & placement, plan type, planning type of common facilities), transfer space, individual housing(type, size, planning type). The guideline for the social environment was developed for 3 items; village making and establishment(resident participation type, resident participation tool, residents' construction participation) and resident education in the course of planning, resident participation(gathering resident opinion, decision making, composition of construction committee, community newsletter).

Heuristic Approach for Lot Sizing and Scheduling Problem with State Dependent Setup Time

  • Han, Jung-Hee
    • Industrial Engineering and Management Systems
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    • 제10권1호
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    • pp.74-83
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    • 2011
  • In this paper, we consider a new lot-sizing and scheduling problem (LSSP) that minimizes the sum of production cost, setup cost and inventory cost. Setup carry-over, setup overlapping, state dependent setup time as well as demand splitting are considered. For this LSSP, we develop a mixed integer programming (MIP) model, of which the size does not increase even if we divide a time period into a number of micro time periods. Also, we develop an efficient heuristic algorithm by combining a decomposition scheme with a local search procedure. Test results show that the developed heuristic algorithm finds a good quality (in practice, even better) feasible solution using far less computation time compared with the CPLEX, a competitive MIP solver.

최대 로트 그룹핑 문제의 복잡성 (On the hardness of maximum lot grouping problem)

  • 황학진
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.409-416
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    • 2003
  • We consider the problem of grouping orders into lots. The problem is modelled by a graph G = (V, E). where each node $\nu\;\in\;V$ denotes order specification and its weight $\omega(\nu)$ the orders on hand for the specification. We ran construct a lot simply from orders or single specification For a set of nodes (specifications) $\theta\;\subseteq\;V$, if the distance or any two nodes in $\theta$ is at most d, it is also possible to make a lot using orders on the nodes. The objective is to maximize the number of lots with size exactly $\lambda$. In this paper, we prove that our problem is NP-Complete when d = 2, $\lambda\;=\;3$ and each weight is 0 or 1. Moreover, it is also shown to be NP-Complete when d = 1, $\lambda\;=\;3$ and each weight is 1, 2 or 3

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생산준비시간 단축과 생산로트사이즈에 대한 연구 (A Study on the Effect of Setup Time Reduction on Production Lot Sizes)

  • 구일섭;김진수
    • 산업경영시스템학회지
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    • 제17권32호
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    • pp.121-126
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    • 1994
  • Setup Time Reduction is an important aspect of the Just-in-Time(JIT) and Zero Inventory(Zl) Concepts since it supports reductions in manufacturing lead times and inventories. It also enables small lot sizes and kanban systems implementation for material flow - achieving major improvements in production floor management. One concept fundamental to the pursuit of JIT production in Japan and other countries is adoption of a setup time reduction. This paper looks at the necessities of setup time reduction and the relations to machine utilization. By using an EOQ model for evaluate the effect of setup time reduction, we get the results that over 75 % reduction in setup time is obtain the desired results in the lot size reduction.

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다종제품의 동적 로트크기결정 모형에서의 생산준비비용 절감효과에 관한 연구 (Setup Cost Reduction in a Multi-Product Dynamic Lot-Sizing Model)

  • 이운식;주철민
    • 산업공학
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    • 제13권2호
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    • pp.217-224
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    • 2000
  • This paper analyzes the effects of setup cost reduction in a dynamic lot-sizing model for a single-facility multi-product problem. In the model, demands for each product are known, no backlogging is allowed, and a single resource is employed. Also, setup cost is defined as a function of capital expenditure to invest in setup cost reduction. Furthermore, in each production period the facility (or plant) produces many products, each representing a fixed part of the involved production activity (or input resource quantity). In this paper, the structure of the optimal solution is characterized and an efficient algorithm is proposed for simultaneously determining the optimal lot size with reduced setup cost and the optimal investment in setup cost reduction. Also, the proposed algorithm is illustrated by a numerical example with a linear and an exponential setup reduction functions.

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지능형 주차 관제를 위한 실내주차장에서 실시간 차량 추적 및 영역 검출 (Realtime Vehicle Tracking and Region Detection in Indoor Parking Lot for Intelligent Parking Control)

  • 연승호;김재민
    • 한국멀티미디어학회논문지
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    • 제19권2호
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    • pp.418-427
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    • 2016
  • A smart parking management requires to track a vehicle in a indoor parking lot and to detect the place where the vehicle is parked. An advanced parking system watches all space of the parking lot with CCTV cameras. We can use these cameras for vehicles tracking and detection. In order to cover a wide area with a camera, a fisheye lens is used. In this case the shape and size of an moving vehicle vary much with distance and angle to the camera. This makes vehicle detection and tracking difficult. In addition to the fisheye lens, the vehicle headlights also makes vehicle detection and tracking difficult. This paper describes a method of realtime vehicle detection and tracking robust to the harsh situation described above. In each image frame, we update the region of a vehicle and estimate the vehicle movement. First we approximate the shape of a car with a quadrangle and estimate the four sides of the car using multiple histograms of oriented gradient. Second we create a template by applying a distance transform to the car region and estimate the motion of the car with a template matching method.

수송공정을 고려한 다분기 공정-저장조 망구조의 최적설계 (Optimal Design of Multiperiod Process-Inventory Network Considering Transportation Processes)

  • 서근학;이경범
    • 제어로봇시스템학회논문지
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    • 제18권9호
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    • pp.854-862
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    • 2012
  • The optimal design of batch-storage network by using periodic square wave model provides analytical lot sizing equations for a complex supply chain network characterized as multi-supplier, multi-product, multi-stage, non-serial, multi-customer, cyclic system including recycling and/or remanufacturing. The network structure includes multiple currency flows as well as material flows. The processes are represented by multiple feedstock/product materials with fixed composition which are very suitable for production processes. In this study, transportation processes that carry multiple materials with unknown composition are added and the time frame is changed from single period into multiple periods in order to represent nonperiodic parameter variations. The objective function of the optimization involves minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders in the numeraire currency. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a multiperiod subproblem for average flow rates and analytical lot-sizing equations. The multiperiod lot sizing equations are different from single period ones. The effects of corporate income taxes, interest rates and exchange rates are incorporated.

칸반시스템에서 수요와 도착간격 변동에 따른 컨테이너 크기에 관한 시뮬레이션 연구 (A simulation study of container size based on the variance of demand and interarrival time in Kanban systems)

  • 손권익;함성호
    • 산업기술연구
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    • 제19권
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    • pp.301-312
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    • 1999
  • The purpose of this paper is to study the effects of container size with multi-stage and multi-item on average inventory and customer service level in Kanban systems. We use the different distributions of demand and interarrival time for each item to show that we had better to change the container size depending on different type of item for this simulation study. The small lot size can be used for container size of a single item if there is no setup time. The container size should be identical with average order size as setup time increases. The fill rate increases if the container size is large with multi-item. However, it is difficult to establish the effective container size because the effects of the container size on the order queue time are not clear. It is suitable to use the average order size as the container size for each item if the variance of demand and interarrival time of each item is relatively small. It is effective to sue the average container size if the variance of them is relatively large.

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Buyer's EOQ model for deteriorating products under order-size-dependent delay in payments

  • Shinn Seong-Whan;Song Chang-Yong
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2002년도 춘계학술대회
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    • pp.243-247
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    • 2002
  • This paper deals with the problem of determining the buyer's economic lot sizing policy for exponentially deteriorating products under trade credit. Assuming that the supplier's credit terms are already known and the length of delay is a function of the buyer's order size, we formulate the mathematical model and the solution algorithm is developed based on the properties of an optimal solution.

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