• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.118-128
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• 1992

The determination of appropriate buffer capacity is an important issue in the design of the advanced manufacturing systems and closely related to the system efficiency and flexibility. Work-in-process is usually not desirable. However, in reality, maintaining some capacity of buffer storage is inevitable in compensation for the machine blocking and break down. The objective of this paper is to present analytical methods and tools for the buffer capacity planning in the Flexible Manufacturing System Environments. The effects when machine blocking is critical factor are also discussed.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.39-44
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• 2001

An instance of domestic exhibition facility building case, the shortage of managing personal in construction resulted serious issue on expenses, times, quality, and safty with no satisfaction on its process and result. According to subject's speciality the CM's application methods are varied and because of its speciality, overall process of building an exhibition facility operating by its owner. This study intends to exam a application possibility of CM on exhibition facility construction to make smooth communication among varied area that following to exhibition facility construction.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.207-220
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• 1999

In this paper, some of the issue about a group sequential method are considered in the Bayesian context. The continuous time optimal stopping boundary can be used to approximate the optimal stopping boundary for group sequential designs. The exact stopping boundary for group sequential design is obtained by using the backward induction method and is compared with the continuous optimal stopping boundary and the corrected continuous stopping boundary.

• IT SoC Magazine
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• s.1
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• pp.37-41
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• 2004

전력이라는 장벽 때문에 공정 스케일링은 점점 어려워지고 있다. 반면, 미래의 컴퓨터와 통신은 더더욱 낮은 전력 소모를 필요로 한다. 아직은 에너지 효율적인 공정이 널리 보급되고 있지 않으므로, 저전력 CMOS SoC 설계는 여전히 큰 어려움이 있다. 본문에서는 CMOS의 전력 감소를 위해 무엇을 어떻게 해야 하는지 알아보도록 한다.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.598-599
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• 2017

In motor application, High efficiency is important. So Design engineer select small gate resistor for lower switching. But There is side effect with small gate resistor. It makes large dv/dt and system request large EMI filter. It makes price increase. This paper introduce about gate drive IC which have solution both of lower loss and EMI issue.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.22-30
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• 2012

Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

• Journal of KIISE
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• v.43 no.1
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• pp.27-33
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• 2016

Virtualization has become one of the most helpful techniques in computing systems, and today it is prevalent in several computing environments including desktops, data-centers, and enterprises. However, since I/O layers are implemented to be oblivious to the I/O behaviors on virtual machines (VM), there still exists an I/O scalability issue in virtualized systems. In particular, when a multi-queue solid state drive (SSD) is used as a secondary storage, each system reveals a semantic gap that degrades the overall performance of the VM. This is due to two key problems, accelerated lock contentions and the I/O parallelism issue. In this paper, we propose a novel approach, including the design of virtual CPU (vCPU)-dedicated queues and I/O threads, which efficiently distributes the lock contentions and addresses the parallelism issue of Virtio-blk-data-plane in virtualized environments. Our approach is based on the above principle, which allocates a dedicated queue and an I/O thread for each vCPU to reduce the semantic gap. Our experimental results with various I/O traces clearly show that our design improves the I/O operations per second (IOPS) in virtualized environments by up to 155% over existing QEMU-based systems.

• Journal of Distribution Science
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• v.12 no.5
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• pp.61-69
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• 2014

Purpose - Many studies report that returns on hedge portfolios that eliminate particular risk types are abnormal from traditional asset pricing models' perspectives. This study examines the pervasiveness of anomalous returns conditioned on business cycle and group size. Research design, data, and methodology - Using KOSPI and KOSDAQ market data from July 1991 to December 2013, we categorize stocks into appropriately sized groups, and dichotomize our sample periods into expansion and recession periods then, we construct hedge portfolios by sorting stocks by anomaly variables and calculate their returns. Results - Four anomalies, including earnings yield, net stock issue, total asset growth, and liquidity appear pervasive across all groups for the entire sample period. However, only the hedge returns of net stock issues are significant across all group sizes during both expansion and recession. Conclusions - A net stock issue can be an appropriate proxy for expected growth of book equity for all group sizes in recessions. This finding could provide insights to investment industry participants and to researchers interested in the relationship between expected growth of book equity and business cycle risk.

• Journal of Information Processing Systems
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• v.14 no.4
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• pp.948-960
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• 2018

Many mobile sensing frameworks have been developed to help researcher doing their mobile sensing research. However, energy consumption is still an issue in the mobile sensing research, and the existing frameworks do not provide enough solution for solving the issue. We have surveyed several mobile sensing frameworks and carefully chose one framework to improve. We have designed an adaptive sampling module for a mobile sensing framework to help solve the energy consumption issue. However, in this study, we limit our design to an adaptive sampling module for the location and motion sensors. In our adaptive sampling module, we utilize the significant motion sensor to help the adaptive sampling. We experimented with two sampling strategies that utilized the significant motion sensor to achieve low-power consumption during the continuous sampling. The first strategy is to utilize the sensor naively only while the second one is to add the duty cycle to the naive approach. We show that both strategies achieve low energy consumption, but the one that is combined with the duty cycle achieves better result.

• The Journal of Information Systems
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• v.30 no.3
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• pp.47-64
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• 2021

Purpose This study measures the degree of improvement in statistical quality experienced by data users when the data of a more convenient measurement method is extended to the analysis target to improve the quality of fine dust statistics service, and the method of expressing analysis data is revised. Ultimately, the main purpose is to explore how it can affect the quality of life of citizens. Design/methodology/approach As it was an issue the emerged as the most important issue at the time, various parties (government, private company, academia, civic groups, etc.) conducted multifaced research on fine dust, but they all focused on measuring technology and demonstrating its effectiveness there was only. This researcher redesigned the study from the viewpoint of statistical data users by changing the research subject from the technology itself to user, different from the existing research cases. The questionnaire method and structural equation were used in the study, and fine dust statistics generated through the existing method and the expanded/revised method were provided and compared for a total of 200 people. Findings Based on the results of the study, I would like to suggest what each entity should ultimately focus on to resolve the fine dust issue in the future.