• Title/Summary/Keyword: Just-in-time

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Direct Just-in-time Methods for Nonlinear Control Design

  • Qiubao Zheng;Kim, Hidenori ura
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.93.4-93
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    • 2001
  • Based on input and output data pairs of nonlinear systems, this paper proposes a simple and effective Just-In-Time (JIT) method, called Direct JIT Control, for nonlinear control design. It uses an inverse model of controlled plant to compute an initial control action, and then adapts the initial control action by adding a fine-tuning control action, depended on the errors between the real outputs and the expected reference signals. Meanwhile, the proposed JIT method accomplishes the adaptation of the inverse model just simply by means of the refreshment of input and output data pairs. In addition, the JIT modeling technique guarantees this method to obtain an approximate inverse model of the controlled nonlinear plant in the neighborhood of a query. Based on a ...

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Automobile Assembly Sequence System Using Production Information (생산정보를 이용한 자동차 조립 서열시스템에 관한 연구)

  • Ock, Young-Seok;Kim, Byung Soo;Bae, Jun-Hee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.3
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    • pp.8-15
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    • 2014
  • For zero inventory and mixed assembly production, JIT (Just In Time) production system in Toyota and JIS (Just-In-Sequence) production system in Hyundai motor co. have been proposed in automobile production areas. Even though the production systems are popular in the areas, many subcontract companies producing part-modules for final production at a parent company suffers from excessive or shortage amount of inventory due to the time gap of production and delivery to the parent company. In this study, we propose an efficient real-time assembly sequence system applying a well-known Pareto method using Paint-In information in painting process and daily production planning information. Based on this system, a production line can estimate the shortage amount of UPH (Units Per Hour) at production line and recovers the amount before operating assembly production in the line. The proposed system provides efficiency on productivity compared with the previous system.

Index of Optimum Harvest Time as Seasonal Hesperidin Content Changes for Citrus lemon Juice in Plastic Film House (레몬 하우스 재배에 있어 시기별 과즙의 Hesperidin 함량변화에 따른 적정수확 기준)

  • Lee, Kwang Ju;Han, Sang Heon
    • Journal of Bio-Environment Control
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    • v.22 no.1
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    • pp.55-59
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    • 2013
  • This study was evaluated that seasonal change of the hesperidin content was in relation to the skin color and weight of fruit in outer or inner side of the canopy, for determine the optimum time and the index of most abundant hesperidin content in lemon fruits juice. The hesperidin content was different with fruit growth and on fruit bearing site of the tree. The fruits of the either side contained the highest hesperidin value at 162 and 176 days after anthesis just after de-greening and the value was highest in the fruits of outer side of the canopy. This time also corresponded to the time just before the cessation of fruit growth. These results suggested that the optimum harvesting period for more hesperidin content was the stage just after de-greening and just before fruit growth cessation.

Sequencing to keep a constant rate of part usage in car assembly lines (자동차 조립라인에서 부품사용의 일정율 유지를 위한 투입순서 결정)

  • 현철주
    • Journal of the Korea Safety Management & Science
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    • v.4 no.3
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    • pp.95-105
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    • 2002
  • This paper considers the sequencing of products in car assembly lines under Just-In-Time systems. Under Just-In-Time systems, the most important goal for the sequencing problem is to keep a constant rate of usage every part used by the systems. In this paper, tabu search technique for this problem is proposed. Tabu search is a heuristic method which can provide a near optimal solution in real time. The performance of proposed technique is compared with existing heuristic methods in terms of solution quality and computation time. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

Analysis of inventory strategy of middle-small company which are ordered form large company which product using JIT(just in time) system (JIT를 적용하는 대기업에 납품하는 중소기업의 재고정책)

  • 이상복
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1997.10a
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    • pp.117-120
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    • 1997
  • In this paper, we analyze Inventory Strategy of our country middle-small Company which are ordered form large Company which product using JIT(just in time) System. Until now, we have not found a good inventory strategy for middle small Company which such like above. In this paper, we first simply survey product lead time, lot size and safety inventory in continuous product system which idea can be adapted our object. We try to mathematical modelling of product lead time, total inventory cost of bur country middle-small Company. We suggest inventory strategy for middle-small Company.

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The Spatial Restructuring and Changes of Locational Pattern of Auto Parts Industry in Korea (자동차 부품산업의 공간적 재구조화와 입지 패턴 변화)

  • Kim, Tae-Whan
    • Journal of the Korean Geographical Society
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    • v.42 no.3 s.120
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    • pp.434-452
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    • 2007
  • The globalization of the economy has strengthened competition in all industries. Facing an intensely competitive environment, the firm's choice of location is one of the most important strategies in enhancing its competitiveness. This paper aims to examine the locational changes and the spatial restructuring of suppliers firm with regard to modularization and customer diversification which result from the process of assembler's restructuring after the financial crisis. Some experimental findings which have been identified throughout this study can be summarized as follows: First, a number of suppliers has been located in the southern Seoul metropolitan area and northern Chungcheong area. And Hyundai's suppliers has been enlarged in the Seoul metropolitan area and Kia's in the Southeastern area. Second, suppliers who transact with several assemblers(network trade) tend to be more dispersed, but dedicated(exclusive) suppliers are more concentrated on assembly plants. Also it was confirmed that 'JIS(Just In Sequence)' system which is more detailed than 'JIT(Just In Time)'system has been used. Third, it was Prominent that suppliers are internalizing in order to reach economies of scale compare to assemblers are externalizing.

A Study on the Data Compression Algorithm for Just-in-Time Rendering of Concentric Mosaic (동심원 모자이크의 실시간 표현을 위한 데이터 압축 알고리즘에 관한 연구)

  • Jee, Inn-Ho;Ahn, Hong-Yeoung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.91-96
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    • 2010
  • Concentric mosaics are made with arranging and summing of video frames by using common spacial standards. Compared with previous works on 3-D wavelet transform coding, we have made important design considerations to enable flexible partial decoding and bit-stream random access. A just-in-time(JIT) rendering engine of the compressed concentric mosaic is developed. However, computationally, it is still demanding to accomplish the real-time rendering. Only the contents for specific scene representation are need to be decoded by maintaining compressed data. Thus our proposed algorithm is able to render real concentric mosaic by using lifting scheme instead of wavelet transform.

A Study of Information Systems for Cross Functional Team and Just-in-Time Production for Competitive Advantage of the Korean fashion Firms (패션기업의 다기능 팀조직 과 적시생산을 위한 정보시스템에 관한 연구)

  • 장대성
    • Journal of the Korea Society of Computer and Information
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    • v.6 no.3
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    • pp.143-151
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    • 2001
  • Fashion Industry is one of the Knowledge Based Industry. The firms which produce the fashion merchandises should shirt to new paradigm of creating new image to delight customers. New image and design is derived from each designer's creative mind. However, self management team work of designers is more creative power than each independent designer's work. This study recommends that the Korean fashion firms implement self management team, concurrent product design and development and Just-in-Time Ⅱ based on sharing information and knowledge with the supplier to set competitive advantage. It can not only reduce cost and improve speed of management and the qualify of products but also satisfy and delight customers.

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Sequencing for Mixed-model Assembly Lines Considering Part Supplier in Just-in-time Production Systems (JIT생산시스템에서 부품공급업자를 고려한 혼합조립순서결정에 관한 연구)

  • 남궁석;이상용
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.1-16
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    • 1997
  • This paper improves the autonomy for supplier's schedule and the flexibility of the final assembly line. The final assembly line is a single work station and each product taking different assembly time is considered. In the assembly schedule, the heuristic method based on the goal chasing method is used. Consequently, suppliers can independently determine their output rates and thus, change their workload pattern according to their needs and priorities. Moreover, this flexibility can help to avoid expensive final-assembly-line stoppages in case of sudden part supply disruptions. The sequencing method can be easily implemented into an existing just-in-time system. In addition, the mathematical model was formulated and the algorithm was explained through the flow chart. The numerical example was given and the efficiency of this method is shown through the analysis of computational results of that example.

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