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논문검색은 역시 페이퍼서치



  • - 주제 : 공학분야 > 산업공학
  • - 성격 : 학술지
  • - 간기: 계간
  • - 국내 등재 : KCI 등재
  • - 해외 등재 : -
  • - ISSN : 1598-2475
  • - 간행물명 변경 사항 :
수록 범위 : 17권 4호 (2012)

단일 제조업자-다소매업자의 공급사슬에서 다완제품의 통합재고모형

김대홍 ( Dae Hong Kim )
In this paper, we investigate an inventory system where a single manufacturer purchases and processes raw materials in order to deliver multiple items to multiple retailers. Earlier study in this type of supply chain only consider a single raw material in order to produce single item, but we consider raw materials in order to produce multiple items. Also, we develop an iterative solution procedure to find the order quantity for the multiple items and raw materials, and the number of shipments between manufacturer and retailers that minimizes the total cost per unit time of the raw materials ordering and holding, manufacturer`s setup and finished items holding, the retailer`s ordering and inventory holding. Numerical examples are presented to show that the proposed heuristic gives good performance.

신뢰성 최적화 설계문제 해결을 위한 강화된 유전 알고리즘

우병훈 ( Byung Hun Woo )
This paper proposes an adaptive genetic algorithm with local search (pro-aGA) for effectively solving reliability optimization design problems. The pro-aGA has the adaptive scheme which can automatically determine the use of local search and adaptively regulate the rates of crossover and mutation operations in genetic algorithm (GA), during genetic search process. For local search, an improved iterative hill climbing method is used and incorporated into GA loop. The adaptive scheme used in the pro-aGA considers the change of the variances resulting from the various fitness values of population at each generation. For comparing the efficiency of the pro-aGA, i) an conventional GA without any adaptive scheme and local search technique, ii) an conventional GA with an local search technique alone, iii) several adaptive GAs (aGAs) with various adaptive schemes are also presented. These algorithms, including the pro-aGA, are tested and analyzed each other using various reliability optimization design problems. Numerical results by various measures of performance show that the proposed pro-aGA outperforms the conventional algorithms.

연속주조 턴디쉬 내 유동제어부재의 배열 변경에 따른 용강유동 거동의 수모델 실험

최병관 ( Byung Kwan Choi ) , 배재호 ( Jae Ho Bae )
This paper present a method to evaluate priorities of critical to quality (CTQ) factors and to derivate key process input variables (KPIVs) using analytic hierarchy process (AHP). The presented method is applied in film-making factory used for flexible packaging units. The capability of a company is very limited, therefore focusing one`s capability on high priority factors is also important. Generally there are too many factors to control them effectively. In addition, it is not easy to verify the relationship between input variables and quality characteristics in real field production level. AHP will be a good way to decide priorities of which are not clearly defined. The presented method will be helpful in evaluating competitiveness of companies by utilizing one`s capability effectively.

공동 납품의 배송 경로 선택과 이익 공헌도에 의한 공통 이익의 배분

이경근 ( Kyung Keun Lee ) , 류시욱 ( Si Wook Ryu )
Multiple suppliers can reduce the total of inventory related cost and delivery cost by cooperating their delivery schedules to a large end-user such as an auto assembly manufacturer or a big department store. In this study, two important decisions are investigated; the first one is how to decide their delivery schedules to minimize the their cooperative total cost, and the next one is allocation of the reduced cost (joint profit) to each supplier by his contribution to joint profit. A mathematical model is developed to find the delivery schedules and the common period of delivery. Moreover, the contribution to joint profit is decided by the Shapley value which is one way to distribute the joint profit to the suppliers, assuming that they all collaborate. A numerical example about allocation of the reduced cost to each supplier is presented at last.

LCD 라인 클린룸에서 기류개선에 관한 연구

국윤부 ( Youn Boo Kook ) , 김정식 ( Jung Sik Kim )
The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. In order to test the accuracy of these correlations, we compared air flow patterns before regulating the opening ratio of access floor with those after regulating. Results after regulating the opening ratio of access floor show good unidirectional uniform airflow pattern. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines.

도로터널 임계속도 산정에 난류모델 및 대류항 처리기법이 미치는 영향

이승철 ( Seung Chul Lee )
This study conducted comparative analysis to estimate critical velocity in tunnel fire under variation of turbulence model and convection schemes using three-dimensional computational fluid dynamics (CFD). In the target tunnel, by one-dimensional way, the calculated critical velocity in the tunnel, 2.22 m/s was estimated, if appling hydraulic diameter, instead of the tunnel height. From our results, the numerical analysis of three turbulence models reaffirmed that standard k-ε model has greater turbulence kinetic energy and turbulence kinetic energy dissipation compared to realizable k-ε and SST k-ω model. In the numerical results of convection schemes, 2nd upwind scheme was the larger backlayering than 1st upwind scheme and the larger gradient of temperature and CO concentration distribution. Therefore, it is necessary to decide appropriate grid number, turbulent model, convection schemes and the location and size of the fire source through comparison with actual experiment results and three-dimensional analysis.

전기로를 이용한 제강공정의 최적 스크랩 배합 비율 선정에 대한 연구

홍정의 ( Jung Eui Hong )
In steel production, an electric arc furnace (EAF) is most commonly used to melt raw material in order to produce liquid steel. Scrap is the main raw material which differs in regard to the content of iron and of some chemical elements. The price of scrap depends on these attributes. In order to obtain the desired quality and quantity, each melting bath unit of steel has either its own material constraints or the constraints for electric arc furnace such as the capacity of EAF. In addition, the availability and transportation of scrap are also restricted because they need space. This research is to create an optimization model which minimizes the cost of raw material The running speed of the model is reasonably guaranteed by properly designing the combinatorial structure with branch and bound rules. Simulation results show significant improvement compared to the : the cost of scrap steel is reduced by 2 to 6% and the time of charging buckets is 2 to 10 minutes faster.

스트림 기반 데이터 전송을 위한 컴퓨터 및 네트워크 최적화 연구

송민규 ( Min Gyu Song ) , 김현구 ( Hyun Goo Kim ) , 변도영 ( Do Young Byun ) , 정태현 ( Tae Hyun Jung ) , 오세진 ( Se Jin Oh ) , 손봉원 ( Bong Won Sohn ) , 이상성 ( Sang Sung Lee ) , 강용우 ( Yong Woo Kang ) , 위석오 ( Seog Oh Wi ) , 노민기 ( Min Ki Noh ) , 조부승 ( Bu Seung Cho )
As the first facility of VLBI observation, KVN (Korean very long baseline interferometer network) is consists`of three radio observatories, which sites are KVN Yonsei, KVN Ulsan and KVN Tamna. In each radio`observatory, more than ten Tera Bytes of data is produced during VLBI observation. But in traditional method,`this massive VLBI (very long baseline interferometer) data recorded in magnetic tape or HDD is transferred to`correlation center by transportation, which cause much loss of time and research products. To overcome this`problem, e-VLBI connecting each radio observatory and correlation center with high speed network was`appeared, and we are now design this concept in KVN by using KREONET (Korea Research Environment`Open NETwork). In this paper, we discuss the methods to transfer VLBI data from radio observatory to`correlation center efficiently. As part of an solution to improve the performance of data transfer, we especially`discuss system tuning for computer and network systems and stream based data transfer. Additionally, we`suggest upgraded data transfer system with this improvements.``
This paper examines the effects of the dividend payment and the certification of venture capital on the underpricing of shares of IPO firms listed in the KOSDAQ markets. The payment of dividends has been known to reduce the information asymmetry about the quality of firms and increase the value of firms with dividends. This result is supported by the information content and signalling hypotheses of the dividend payment and the certification effect of venture capital. Our empirical results show that IPO shares with dividend payments and venture capital investments were less underpriced than IPO shares without dividend payments and venture capital investments. Their difference is also statistically significant. This paper suggests that the payment of dividend and venture capital investment have indeed the information content and the effects of certification and signal the quality of firms to the market, resulting in the reduction of underpricing of IPO shares.

공급업자-구매업자의 공급사슬에서 운송비할인을 고려한 통합재고모형

김대홍 ( Dae Hong Kim )
In this paper, we consider a single vendor single buyer supply chain problem where a single vendor orders raw materials from its supplier, then using its manufacturing processes converts the raw materials to finished goods in order to deliver finished goods to a single buyer. It is a fact that transportation cost is a major part of the total operational cost. However, in most vendor-buyer models, the transportation cost is only considered implicitly as part of fixed ordering cost and thus is assumed to be independent of the size of shipment. In this study we incorporate transportation cost into the model and we develop an integrated lot-splitting model of facilitating multiple shipments in small lots between vendor and buyer. Also we develop an iterative heuristic solution procedure to find the order quantity for finished goods and raw materials, and number of shipments between vendor and buyer. Numerical examples are presented for illustrative purpose.
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