• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.33-40
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• 2020

As hydrogen utilization becomes more active recently, a large amount of hydrogen should be supplied safely. Among the three supply methods, liquefied hydrogen, which is an optimal method of storage and transportation convenience and high safety, has a low temperature of -253℃, which is complicated by the liquefaction process and consumes a lot of electricity, resulting in high operating costs. In order to reduce the electrical energy required for liquefaction and to raise the efficiency, hydrogen is cooled by using a mixed refrigerant in a precooling step. The electricity required for the precooling process of the mixed refrigerant can be reduced by using the cold energy of LNG. Actually, LNG cold energy is used in refrigeration warehouse and air liquefaction separation process, and a lot of power reduction is achieved. The purpose of this study is to replace the electric power by using LNG cold energy instead of the electric air-cooler to lower the temperature of the hydrogen and refrigerant that are increased due to the compression in the hydrogen liquefaction process. The required energy was obtained by simulating mixed refrigerant (MR) hydrogen liquefaction system with LNG cold heat and electric system. In addition, the power replacement rate of the electric process were obtained with the pressure, the temperature of LNG, the rate of latent heat utilization, and the hydrogen liquefaction capacity, Therefore, optimization of the hydrogen liquefaction system using LNG cold energy was carried out.

• 가정과삶의질연구
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• 제23권1호
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• pp.125-137
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• 2005

Information technology is an important driving force that has changed consumer information environments. In order to adjust in the new environments, consumers need an innovative information system. The purpose of this study was to develop a Consumer Information System (CIS). CIS is a device that supports consumer's decision-making process and elevates consumer information competence. The CIS was constructed by the following steps: (1) organization of developers, (2) systematization of consumer information, (3) data loading, (4) integration of consumer database: data warehouse, (5) data distribution, (6) composition of data mart, (7) use of data access tools: data-mining, OLAP, statistical analysis, Q+R, (8) data visualization: web server.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.441-442
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• 2000

예건 공정을 거친 양파를 구입하여 2평 정도의 콘테이너 창고에 넣어 실온에서 보관을 하면서 3ppm의 농도로 오존을 처리한 결과 무처리구에 비해 무게 감소율이 현저하게 낮았으며 부패 발생율도 무처리구는 30일 경과 시 10% 정도인 것에 비해 오존 처리 시 2%로 아주 낮았다. 또한 보관 중에 발생되는 양파의 냄새도 완전히 억제하였다.

• Journal of Information Technology Applications and Management
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• 제10권2호
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• pp.19-31
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• 2003

We propose an indexing technique and an index selection algorithm for optimal OLAP query processing in object database systems, Although there are many research results on the relational database systems for OLAP Query processing, few researches have been done on the object database systems. Since OLAP queries represent complex business logic on a huge data ware-house, object database systems supporting the OLAP queries should have higher performance. Proposed bitmap index structure is an extension of conventional bitmap indexes for adapting object databases and provides higher performance with lower space overhead. We also propose a linear time solution of the index selection problem that will be used in the OLAP query optimization process.

• 한국농촌건축학회논문집
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• 제1권3호
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• pp.35-44
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• 1999

When modern farm houses were built, they were made up of only residential parts. So that many new accessory building-private residential room, toilet, warehouse, storeroom, barn, cattle pen and etc.-were made without any order around modern farm houses. This study is aimed at grasping how the process and contents of extension of the accessory building of modern farm houses have been changed, understands and explicates the reason why accessory buildings of modern farm houses were changed and bring forward better directions about accessory building of modern farm houses at Samchok seashore area of Kangwon Province. The way for it which be made good that the scenery of a rural district was ruined by accessory buildings distributes and develops various standard models about accessory buildings that they are becoming to modern farm houses.

• 대한안전경영과학회지
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• 제16권3호
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• pp.363-368
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• 2014

During the fierce competition among the companies, improvement of logistics center managing efficiency is importantly recognized. Among them, studies on improvement of picking work process on about 55% of logistics center managing costs are continuously conducted. And, most of studies focus on analysis on strengths and weaknesses of picking method performable on the stage of logistics center design, etc, so the purposes of this research are to define load location rule by product releasing frequency in logistics managing environment based on conveyer and suggest expected effects by simulation analyzing method to improve picking managing efficiency.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (C)
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• pp.205-207
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• 2006

유비쿼터스 컴퓨팅 환경의 실현 가능성이 높아지면서 Automatic identification and Data Capture(AIDC)에 대한 많은 연구들이 이루어지고 있다. AIDC 기술 중 하나인 Radio Frequency IDentification(RFID)는 라디오 주파수에 따라 반응하는 태그를 이용하여 사람이나 사물을 인식하는 기술이다. 또한 RFID 특성을 지원하면서 발생 이벤트를 효율적으로 처리하기 위해 다양한 미들웨어가 개발되고 있다. 그러나 미들웨어의 지원에도 불구하고 RFID 시스템 개발자는 많은 부가적 지식을 알아야만 한다. 이 점을 해결하여 RFID 기술을 편리하게 사용하도록 돕는 Business Aware Framework(BizAF)이 제시되었다. 본 논문에서는 BizAF를 기반으로 여러 애플리케이션을 개발한 경험을 바탕으로 RFID 비즈니스 이벤트들을 생성하기 위한 모델링 프로세스를 제시하고자 한다.

• 산업경영시스템학회지
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• 제13권21호
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• pp.101-110
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• 1990

This study presents a two-level inventory distribution system with one-upper level facility(warehouse) in first echelon and n-lower level facilities(stores) in the second echelon. The demand process at the upper level is induced by the aggregated backorder processes of n independently operated lower level facilities in parallel. For the upper level and the lower level we find the decision points and the distribution function of the aggregate backorders from n-stores. Optimal allocation units and expected system profits are obtained. If the product is of great enough importance to the customer, echelon structure will include a shadow installation. Also, this case is analyzed. Numerical examples are presented to illustrate the results for each case.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2003년도 창립학술대회
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• pp.11-24
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• 2003

It is far more expensive for companies to acquire new customers than it is to retain customers. As a result, companies are turning to Customer Relationship Management (CRM) in order to make decisions about managing the relationship and the profitability of those customer relationships. CRM is a strategy that integrates the concepts of Knowledge Management, Data Mining and Data Warehousing in order to support the organization's decision -making process to retain long-term and profitable relationships with its customers. This paper examines the design implications that CRM poses to data warehousing. We then present a robust data warehouse schema to support CRM analyses and decisions. For example, the proposed schema could be used to calculate customer profitability and to identify social networks of influence between customers. The paper also discusses future areas for research pertaining to CRM data warehousing and data mining.

• Journal of Information Technology Applications and Management
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• 제13권1호
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• pp.137-147
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• 2006

Spatiotemporal data are records of the spatial changes of moving objects over time. Most data in corporate databases have a spatiotemporal nature, but they are typically treated as merely descriptive semantic data without considering their potential visual (or cartographic) representation. Businesses such as geographical CRM, location-based services, and technologies like GPS and RFID depend on the storage and analysis of spatiotemporal data. Effectively handling the data analysis process may be accomplished through spatiotemporal data warehouse and spatial OLAP. This paper proposes a multidimensional model for spatiotemporal data analysis, and cartographically represents the results of the analysis.