• 한국공간정보시스템학회 논문지
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• 제7권3호
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• pp.119-130
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• 2005

공간 데이터 웨어하우스는 공간정보를 주제 중심적이고 통합적이며 시간성을 가지는 비 휘발성 자료로 저장하여 의사결정을 효율적으로 지원하는 시스템이다. 이 시스템은 구축기와 공간 데이터 웨어하우스 서버로 구성되어 있다. 공간 데이터 웨어하우스 서버는 구축기에서 전송된 데이터를 적재하기 위해 사용자 서비스를 정지하고, 사용자의 빠른 응답시간을 위해 적재된 데이터로 색인을 구축한다. 색인 구축을 위한 기존 기법에는 벌크 삽입 기법과 색인 전송 기법이 있다. 벌크 삽입 기법은 색인을 구축하기 위한 클러스터링 비용이 크며 검색 성능도 떨어진다. 색인 전송 기법은 주기적인 소스 데이터의 변경을 지원하지 않는 문제점이 있다. 본 논문에서는 공간 데이터 웨어하우스에서의 부분 색인을 이용한 효율적인 색인 재구축 기법을 제안한다. 제안 기법은 부분 색인을 직접 전송, 기록하며 물리적 위치 정보를 예상하여 기록할 수 있는 효율적인 색인 재구축 기법이다. 구축기에서 추출된 데이터를 공간의 근접도가 아닌 색인의 구조에 맞게 클러스터링하며, 생성된 각 클러스터를 부분 색인으로 구성하여 페이지 단위로 전송한다. 공간 데이터 웨어하우스 서버에서는 전송된 부분 색인을 저장하기 위해 물리적으로 연속된 공간을 예약하고 예약된 공간에 부분 색인을 기록한다. 기록된 부분 색인을 공간 데이터 웨어하우스 서버의 기 구축된 색인에 삽입함으로써 색인 재구축을 위한 검색, 분할, 재조정 비용이 최소화된다.

• 산업공학
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• 제15권2호
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• pp.159-171
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• 2002

Data Warehouses integrate data from multiple heterogeneous information sources and transform them into a multidimensional representation for decision support applications. Data warehousing has emerged as one of the most powerful tools in delivering information to users. Most previous researches have focused on marketing, customer service, financing, and insurance industry. Further, relatively less research has been done on data warehouse systems in the complex manufacturing industry such as ship production, which is characterized complex product structures and production processes. In the ship production, data warehouse systems is a requisite for effective cost analysis because collecting and analysis of diverse and large of cost-related(material/production cost, productivity) data in its operational systems, was becoming increasingly cumbersome and time consuming. This paper proposes architecture of the data warehouse systems to support cost analysis in the ship production. Also, in order to illustrate the usefulness of the proposed architecture, the prototype system is designed and implemented with the object of the enterprise of producing a large-scale ship.

• 한국전자통신학회논문지
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• 제8권12호
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• pp.1803-1810
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• 2013

물류창고 시스템에서는 물류의 입고/출고에 따른 재고현황의 변동이 잦고, 내용물에 따라 주위환경요소가 큰 영향을 미칠 수 있으므로, 재고현황 및 환경요소를 빠르고 정확하게 관리하는 것이 물류관리에 있어서 매우 중요하다. 하지만 현재 제안되고 있는 RFID 기반의 물류관리 시스템은 RFID 리더 간 통신에 대해 통일된 국제규격이 없고, 일반적으로 사용되는 중앙집중방식 MAC 방식의 경우 클러스터 헤더의 이동이나 채널 상황의 영향으로 인해 이 시간동안 각 노드 간 통신이 불가능하다. 따라서 본 논문에서는 채널 상황에 능동적으로 대처할 수 있는 물리계층 정보를 이용한 와이미디어 MAC 프로토콜 기반의 릴레이 협력통신 방안에 대한 결과를 제안한다.

• 산업경영시스템학회지
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• 제34권1호
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• pp.1-8
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• 2011

Controlling industrial vehicle operated by human in warehouse was not simple since the information transfer for controlling the vehicle was not easy. However, as the technology for the WMS (Warehouse Management System) has been advanced and the PDA (Personal Digital Assistant) has come into wide use in a workplace, the control of man-operated vehicle became less difficult as do to AGVS (Automated Guided Vehicle System). This study examines the ways to improve the efficiency of warehouse operation through introducing rule of task assignment for the vehicles, particularly forklift. This study, basically, refer to AGV operation policy because a great number of studies for AGV dispatching rule have been done and the mechanism for the controlling vehicles is very similar. The workers in field prefer to simple dispatching rules such as Shortest Retrieval Time First (SRTF), Shortest Travel Time First (STTF), and Longest Waiting Time First (LWTF). However, these rules have potential disadvantage. Thus, several rules made up by combining rules mentioned above are introduced and these new rules use threshold value or evaluation formula. The effectiveness of these new rules are tested by simulation and the results are compared. This study proposes favorable dispatching rules for forklift in warehouse for the efficiency of the vehicle operation and stability of service level.

• 무역상무연구
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• 제59권
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• pp.81-112
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• 2013

This article intends to examine main features of revision in relation to the duration of cover in the Institute Cargo Clauses 2009 and the results of analysis are as followings. First, the cover, which had been "warehouse to warehouse", has been extended to what may be called "shelf to unloading". Thus the insurance attaches when the goods are first moved within the warehouse or place of storage at the named place for the purpose of immediate loading for the commencement of transit. Secondly, the new termination Clause 8.1.3 requires an election by the assured, or their employees, to use a vehicle or container, for storage other than in the ordinary course of transit. Thirdly, Clause 10.1, which deals with the assured's voluntary change of voyage, was amended to solve the problem that the words "held covered" could be misunderstood by an assured without specialist knowledge of English marine insurance law to be a guarantee of cover, even where cover would not be commercially available. Finally, Clause 10.2 is designed to solve the so-called "phantom ship problem", arising from the harsh decision in The Prestrioka. The new Clause 10.2 provides protection for an innocent assured in the situation of a phantom ship.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.397-414
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• 2005

In the existing literature, most of the purchasing models were developed only for retailers problem ignoring the constraint of storage capacity of retailers shop/showroom. In this paper, we have developed a deterministic model of wholesaler-retailers' problem of single product. The storage capacity of wholesaler's warehouse/showroom and retailers' showroom/shop are assumed to be finite. The items are transported from wholesaler's warehouse to retailers' Own Warehouse (OW) in a lot. The customer's demand is assumed to be displayed inventory level dependent. Demands are met from OW and that spaces of OW will immediately be filled by shifting the same amount from the Rented Warehouse (RW) till the RW is empty. The time duration between selling from OW and filling up its space by new ones from RW is negligible. According to relative size of the retailers' existing (own) warehouse capacity and the demand factors, different scenarios are identified. Our objectives are to optimize the cost functions of wholesaler and two retailers separately. To solve this problem, a real coded Genetic Algorithm (GA) with roulette wheel selection/reproduction, whole arithmetic crossover and non-uniform mutation is developed. Finally a numerical example is presented to illustrate the results for different scenarios. To compare the results of GA, Generalised Reduced Gradient Method has been used for the problem. Also, a sensitivity analysis has been performed to study the variations of the optimal average cost with respect to the different parameters.

• 통상정보연구
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• 제7권1호
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• pp.55-74
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• 2005

Recently, many enterprises have attempted to construct data warehousing systems for decision-support. Data warehouse is an intelligent store of data that can aggregate vast amounts of information. Building DW requires two important development issues:(i) DW for the decision making of business users and (ii) metadata within it. Most DW development methodologies have not considered metadata development; it is necessary to adopt a DW development methodology which develops a DW and its metadata simultaneously. Metadata is a key to success of data warehousing system and is critical for implementing DW. That is, metadata is crucial documentation for a data warehousing system where users should be empowered to meet their own information needs; users need to know what data exists, what it represents, where it is located, and how to access it. Furthermore, metadata is used for extracting data and managing DW. However, metadata has failed because its management has been segregated from the DW development process. Metadata must be integrated with data warehousing systems. Without metadata, the decision support of DW is under the control of technical users. Therefore, integrating data warehouse with its metadata offers a new opportunity to create a more adaptive information system. Therefore, this paper proposes a DW development methodology from a metadata perspective. The proposed methodology consists of five phases: preparatory, requirement analysis, data warehouse (informational database) development, metastore development, and maintenance. To demonstrate the practical usefulness of the methodology, one case is illustrated

• 한국연초학회지
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• 제24권2호
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• pp.88-93
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• 2002

This study was carried out to investigate the changes of chromatic, chemical and organoleptic characteristics of green leaf tobaccos during storage in warehouse. Eight grades(flue-cured ; A2O, B2O, C2L and D2L, burley ; A2T, B2T, C2W and D2W) of green loaves produced in 2001 were stored during 8 months(Oct. 30, 2001 to Jun. 30, 2002) in warehouse of Kimcheon(flue-cured) and Namwon(burley) Leaf Tobacco Processing factory, respectively. Moisture contents of D2L in flue-cured and four grades in burley were significantly decreased during storage in warehouse. Redness(a) values of six grades except for D2L and D2W were significantly increased during storage. Lightness(L), yellow(b) and pH values, and the contents of nicotine, total nitrogen and total sugar were not changed during storage. Irritations of flue-cured tobacco were increased, whereas tastes were decreased during storage. Irritations and tastes of burley tobacco were little changed during storage. The result suggests that the flue-cured green leaf being processed as early as possible for minimizing the deterioration of smoke taste during storage in warehouse.

• 한국화재소방학회논문지
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• 제24권4호
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• pp.47-54
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• 2010

본 연구에서는 창고 화재 사고의 위험성을 파악하기 위해서 중규모 실물 화재 실험 장비인 룸코너 시험기(Room Corner Tester)를 통해 구축된 단위 구성품의 화재 특성 DB를 바탕으로 화재에 취약할 것으로 판단되는 의류 창고를 실험 모델로 구성하여 실물 화재실험 장비인 라지 스케일 칼로리미터(Large Scale Calorimeter)에서 실물 화재실험을 실시하였다. 창고 모델의($3m{\times}3m{\times}2.4m$) 벽체는 불연등급의 그라스울과 일반 스티로폼 샌드위치 패널로 구성하였다. 실험결과 최대 열방출률은 그라스울 샌드위치 패널 창고모델에서 5MW, 스티로폼 샌드위치 패널 창고모델에서 11MW를 나타내었다.

• International Journal of Safety
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• 제5권2호
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• pp.29-33
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• 2006

A numerical flow analysis of the case of a refrigeration warehouse where an unusual death of an operator occurred by deficiency of oxygen is performed by using STAR-CD program of the computational fluid dynamics (CFD) code. The refrigeration room of the warehouse for storing the fruits maintains an atmosphere of 95% nitrogen and 5% oxygen by volume. When the operator was found dead in the refrigeration room, the room was in normal operating conditions except for the fact that the auxiliary door had been left open. For the flow analysis, unsteady 3-dimensional natural convection with mass transfer is considered. The flow analysis result is compared with the oxygen concentration level measured against time during on-site investigation. The change in oxygen concentration level in the warehouse due to the opening of the auxiliary door is found to be negligible.