• Journal of Korean Institute of Industrial Engineers
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• v.15 no.1
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• pp.41-50
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• 1989

This paper deals with the problem of space allocation of items within a warehouse. Recognizing the importance of weights associated with material handling, mathematical models are developed for two cases, out-and-back selection and storage retrieval interleaving. It is proved that the density order index rule we proposed generates an optimal solution for the first model. An example problem solved with the pairwise interchange method indicates that the rule is also fairly efficient for the second model. The proposed rule is compared with other assignment rules of warehouse space such as COI rule, space and popularity.

• IE interfaces
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• v.12 no.2
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• pp.210-221
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• 1999

Several researchers have previously studied the problem of allocating buffer storage to maximize the throughput rate and/or minimize the mean buffer average of a transfer line for a given total amount of buffer space. But there seems to be very little difference in performance between intuitively reasonable and optimal allocations. This paper proposes and illustrates a methodology, based on the robust design concept of Taguchi, to allocate buffer storage of long transfer lines with a given total amount of buffer capacity when up and down times follow exponential distributions, respectively. We show how this procedure using simple heuristic rule can be used for design of long transfer lines.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.125-137
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• 2006

One of the important tactical problems for the efficient operation of container terminals is to determine the usage of storage space There are two different strategies for stacking containers; mixing strategy, in which outbound containers and inbound containers are mixed in the same block, and segregating strategy, in which outbound containers and inbound containers are stacked in blocks different from each other The performance of space allocation strategies also depends on the types of handling equipment in the yard and the number of handling equipment allocated to each block. A simulation model is developed considering various handling characteristics of yard cranes. Performances of various space and equipment allocation strategies are evaluated by using the simulation model.

• Journal of Information Processing Systems
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• v.14 no.1
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• pp.140-149
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• 2018

Social data such as users' comments are unstructured in nature and up-to-date technologies for analyzing such data are constrained by the available storage space and processing time when fast storing and processing is required. On the other hand, it is even difficult in using a huge amount of dynamically generated social data to analyze the user features in a high speed. To solve this problem, we design and implement a topic association analysis system based on the latent Dirichlet allocation (LDA) model. The LDA does not require the training process and thus can analyze the social users' hourly interests on different topics in an easy way. The proposed system is constructed based on the Spark framework that is located on top of Hadoop cluster. It is advantageous of high-speed processing owing to that minimized access to hard disk is required and all the intermediately generated data are processed in the main memory. In the performance evaluation, it requires about 5 hours to analyze the topics for about 1 TB test social data (SNS comments). Moreover, through analyzing the association among topics, we can track the hourly change of social users' interests on different topics.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.281-286
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• 2004

It's important to operate the yard for improving to the productivity in container terminal effectively. Because the automated container terminal(ACT) has storage yard of automation and horizon, it's character is different from conventional terminal. As the automation yard in ACT is operated by the automated equipments, it needs to an efficient storage plan which is connected the automated equipment, the external truck, the shipment etc.. Hut the traditional method of storage plan is the space assignment problem. The efficiency of yard decreases and it is brought about increase of shipment time, because real-time automated equipments and present yard status is not reflected in. In order to solve this problems, we propose the algorithm for real-time storage location of container considering shipment plan, yard status and the state of ATC.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data scalable growth and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for suports snapshots and reorganizations.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for supports snapshots and reorganizations.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.1-10
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• 2016

Magnetic disks have been used for decades in auxiliary storage devices of computer systems. In recent years, the use of NAND flash memory, which is called SSD, is increased as auxiliary storage devices. However, NAND flash memory, unlike traditional magnetic disks, necessarily performs the erase operation before the write operation in order to overwrite data and this leads to degrade the system lifetime and performance of overall NAND flash memory system. Moreover, NAND flash memory has the lower endurance, compared to traditional magnetic disks. To overcome this problem, this paper proposes EPET (Enhanced Prediction and Elapsed Time) wear leveling technique, which is especially efficient to portable devices. EPET wear leveling uses the advantage of PET (Prediction of Elapsed Time) wear leveling and solves long-term system failure time problem. Moreover, EPET wear leveling further improves space efficiency. In our experiments, EPET wear leveling prolonged the first bad time up to 328.9% and prolonged the system lifetime up to 305.9%, compared to other techniques.

• Journal of architectural history
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• v.12 no.3
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• pp.131-148
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• 2003

This study has main purpose to understand the traditional house, not by outside researcher's but by inside dweller's view. The house in Geochang, is descendent house of Jeong-On who was faithful scholar at Chosen Dynasty. In order to understand, I restore firstly the house form and space at traditional era, 60 years ago, and every dwellers not only family members but also servants and guests, by interviewing old matriarch. One of the main rules of the house disposition is Ancester worshipping life. Worshipping floor of Anchae, main building, is located unusually in front of Shrine for Jeong-On, in order to connect all activities directly. Sarangchae, men's building, opened to the funeral mourners, is separated by a wall because women have to serve foods and wail at the backside. Space for everyday life is separated by man/woman, insider/outsider, master/subordinate. Agricultural production is also key factor of the space allocation: big storage buildings for rice crop needed to tenant farming. Both activities of ancestor worship ceremony and guest greeting need large kitchen annex area for food preparation and serving space of rear veranda floor. A number of guests visit the house: guest-greeting activity is taken place from the family pavilion, Neungheo-Jeong and Saranchae by the social position. This study show that architectural space and form of the house reflects exactly dwellers life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.433-442
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• 2017

This study consists of five case studies of the catering facilities of newly-built elementary schools' in Sejong City, regarding the spatial configuration and allocation. The analysis indicated that the space allocated in the cooking area in the five schools compared to the standard was as follows: School A; 99.2%, B; 91.1%, C; 81.4%, D; 110.8%, E; 88.1%. Accordingly, the cooking area was close to, or slightly above the standard; nevertheless, other areas in the facilities were not allocated sufficient space and were not appropriately planned. Among the other findings, the receiving areas of three schools were not even planned, and the receiving works were carried out in the pre-preparation area. Considering the flow of the dish-washing process, the width of the room should be at least 3.6 meters with a passage width of 1.6 meters, and easy access to the cooking and dining areas must be equipped. An interview with all five supervisors showed that most complaints focused on the cooking and dishwashing areas, whereas there were none in the storage and workers' area. The result highlights the importance of the cooking and dishwashing areas as the main functions in catering facilities, and future planning strategies should consider this aspect.