• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.13-17
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• 2003

본 논문에서는 낮은 대역폭, 높은 지연, 그리고 잦은 네트워크 단절로 인한 모바일 컴퓨팅 환경의 문제점들을 해결하기 위한 효과적인 캐시 적재 기법으로서 협업 추천 기반의 데이터 마이닝 전략을 제안하였다. 캐시 적재가 모바일 클라이언트의 이러한 문제점들을 해결하기 위한 효율적인 방법이 된다는 기존의 연구는 많이 진행되어 왔다. 하지만 모바일 컴퓨터의 요구에 대한 이력 정보만을 이용한 기존의 연구는 모바일 클라이언트가 필요로 하는 모든 정보 요구를 만족하지 못하였다. 특히 저장 공간의 제약을 갖는 모바일 컴퓨터의 한계 때문에 더욱 큰 어려움을 갖게 되었다. 본 연구에서는 모바일 클라이언트의 이력 정보에 대하여 데이터 마이닝 기법을 적용한 캐시 적재 기법을 제안하여 적은 캐시 용량만으로도 모바일 클라이언트의 요구를 만족할 수 있는 아이템들을 효과적으로 서비스할 수 있도록 하였다. CSIM Simulator를 이용하여 모의 데이터를 생성하여, 제안 모형의 성능 평가를 위한 실험을 수행하였다. Cache hit ratio를 이용한 객관적인 성능 평가를 통하여 제안된 모형이 모바일 클라이언트의 캐시 적재 기법으로서 우수한 성능을 보임이 확인되었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.314-319
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• 2021

Problems that satisfy various constraints while maintaining weight balance in ships or aircraft were studied. In addition, a study was conducted to solve the problem with a mathematical method under the condition that the shape and weight of the load are the same and the m×n (m and n are all odd) mesh structures. The problem is that the existing mathematical weight balancing method is not suitable for circular structures. In this paper, we studied the load stowing problem in a circular space where objects are loaded at the vertices of N equilateral polygons. Assuming that all N conformal polygons have an even number of angles, it was proved that a loading method that always maintains weight balance regardless of the variety of number of loads. By providing the structure and loading method of the drone loading ship, we showed that our method was appropriate.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.2
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• pp.1-15
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• 2007

This paper proposes a method for determining the number of storage rooms and designing the storage layout in warehouses for pyramid type stacks whose example are slacks for steel coils, paper rolls, and drums for oils. Formulas are derived for estimating the expected values and the variances of various handling times by cranes. From the derived formulas, the expected queuing time of road trucks is estimated. Base on the derived formulas, this study derives the cost function for determining the optimal numbers of rows, bays, and tiers of stacks and sizing cranes under the condition that the requirement for storage space is satisfied. Results of numerical analysis are provided.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.1
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• pp.37-48
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• 2020

Logistics centers, distribution centers, or warehouse facilities increasingly dominate urban and suburban landscapes, their enormous but blank, repetitive facades completely overshadowing adjacent buildings. Mostly ignored by architects, this new building type symbolically represents the arrival of post-anthropocene, or post-urbicene era of architecture, in which an increasing portion of our built environment will not be intended for human occupancy, but rather for use by machines and artificial intelligence. As a new wave of logistics centers are becoming more automated, and more supersized, it is important to deepen architects' understanding of the organizational logic and programming factors that inform the overall design decisions for these facilities. With a particular focus on three case studies--Coupang, E-Mart, and Amazon Fulfillment Centers, this research examines the current trends in automation and expansion of logistics centers, and offers an analysis and forecast for future facilities in South Korea.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.77-92
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• 2006

This paper proposes an efficient spatial data manager for map services in mobile environment. It is designed to provide interoperability and efficient performance at once. To provide interoperability and reusability, the spatial data manager conforms to international standards such as the OpenGIS Simple Features Implementation Specification for OLE/COM, OpenGIS Geography Markup Language (GML) Encoding Specification developed by the Open Geospatial Consortium (OGC). The spatial data manger exploits physical main memory using Address Windowing Extensions supported by Microsoft Windows to manage spatial data for efficient performance by reducing time to read data from disk on user's request. The format of the spatial data in main memory is target data (GML) to reduce conversion time from source data to it. Progressive transmission is also provided to reduce latency time by representing only received partial data for mobile environment without waiting whole transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1095-1101
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• 2020

Vessels or aircraft should be loaded with containers or cargo to maintain weight balance in order to be stable when navigating the route. The container loading algorithm is known as the NP problem and several heuristic methods have been studied. Containers can be characterized by the uniform volume and weight, which makes it easier to find an optimal loading method. In this paper, we propose an algorithm for weight balance when the volume and weight of an object are uniform. It is assumed that the loading space has a special structure of m * n mesh (where m and n are both odd). In this case, we designed a greedy algorithm and proved that the algorithm is optimal in that it can always find a loading position that maintains a weight balance regardless of the number of objects. Our algorithm can be used in many engineering problems, such as loading algorithms and load balancing problems.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.6
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• pp.687-692
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• 2004

In this paper, we proposed an efficient cache hoarding method in mobile computing environments using collaborative filtering. This method is used for solving the difficult problem of mobile computing, which is the vacuum of information service depending on low bandwidth, long delay, and frequent network disconnection. Many previous researches have been studied a cache hoarding approach for solving these problems of mobile client. But, the research of history information of mobile client did not support all informative requests for mobile clients. In our research, collaborative filtering model using history information and location data of mobile client is proposed. This proposed model supports an efficient service of necessary items for client's requirement. For the performance evaluation of proposed model, we make an experiment of simulation data using SAS enterprise miner. According to objective evaluation using cache hit ratio, we show that our model has a good result.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.99-103
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• 2003

The most commonly used method for space management in the industry is development of site plans. These plans outline how to manage material deliveries, staging areas, and crane locations for construction sites in suburban area but not in congested urban areas. This study focuses on how to efficiently manage space for construction facilities on high-rise buildings in congested urban areas where normally space for facilities around a building footprint is not available. The limitations of available horizontal space create a need to explore vertical expansion of facilities. This raises new aspects of vertical facility handling and flow that need to be considered in the facility design problem. The construction facilities layout plan method provides layout planners with a valuable technique to develop efficient sequences of work that optimally defines how to efficiently utilize the construction facilities and minimize the travel of specific facilities effort on multiple-floor buildings. A genetic algorithm-based heuristic will be presented for generating block layouts for multiple-floor la)rout problems.

• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.119-130
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• 2005

A spatial data warehouse is a system that stores geographical information as a subject oriented, integrated, time-variant, non-volatile collection for efficiently supporting decision. This system consists of a builder and a spatial data warehouse server. A spatial data warehouse server suspends user services, stores transferred data in the data repository and constructs index using stored data for short response time. Existing methods that construct index are bulk-insertion and index transfer methods. The Bulk-insertion method has high clustering cost for constructing index and searching cost. The Index transfer method has improper for the index reconstruction method of a spatial data warehouse where periodic source data are inserted. In this paper, the efficient index reconstruction method using a partial index in a spatial data warehouse is proposed. This method is an efficient reconstruction method that transfers a partial index and stores a partial index with expecting physical location. This method clusters a spatial data making it suitable to construct index and change treated clusters to a partial index and transfers pages that store a partial index. A spatial data warehouse server reserves sequent physical space of a disk and stores a partial index in the reserved space. Through inserting a partial index into constructed index in a spatial data warehouse server, searching, splitting, remodifing costs are reduced to the minimum.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.33-36
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• 2001

LCL은 컨테이너에 화물을 적재할 때 한 화주가 컨테이너의 공간을 전부 사용하는 FCL과 달리 여러 명의 화주가 각자의 화물을 한 컨테이너에 적재하는 방식을 말한다. 기존의 LCL 화물 선적은 화주의 요청에 의하여 선주가 Forward를 통하거나 이전에 거래하던 화주를 통하여 화물을 모집하여 남는 CBM(Cubic Miter)를 태우게 된다. 본 논문에서는 이들을 웹 상에서 서비스하는 LCL 화물 정보시스템을 제안한다. 이 시스템은 화주와 선주의 정보를 시스템을 통하여 다른 화주나 선주에게 제공하는 한편 이들 정보들을 바탕으로 LCL 선적할 화주의 결정에 필요한 적절한 정책은 시스템의 Agent들에 의해서 이루어진다. 그리고 데이터베이스의 접근에 있어서도 CORBA를 이용하여 이 기종의 시스템들에 분산된 데이터베이스에 쉽게 접근할 수 있도록 하여 보다 많은 정보를 바탕으로 시스템을 운영할 수 있다.