• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.1
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• pp.39-55
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• 2011

Process monitoring has been emphasized for the monitoring of complex system such as chemical processing industries to achieve the efficiency enhancement, quality management, safety improvement. Recently, ICA (Independent Component Analysis) based MSPC (Multivariate Statistical Process Control) was widely used in process monitoring approaches. Moreover, DICA (Dynamic ICA) has been introduced to consider the system dynamics. However, the existing approaches show the limitation that their performances are strongly dependent on the statistical distributions of control variables. To improve the limitation, we propose a novel approach for process monitoring by integrating DICA and LOF (Local Outlier Factor). In this paper, we aim to improve the fault detection rate with the proposed method. LOF detects local outliers by using density of surrounding space so that its performance is regardless of data distribution. Therefore, the proposed method not only can consider the system dynamics but can also assure robust performance regardless of the statistical distributions of control variables. Comparison experiments were conducted on the widely used benchmark dataset, Tennessee Eastman process (TE process), and showed the improved performance than existing approaches.

• KIEAE Journal
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• v.17 no.3
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• pp.35-44
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• 2017

Purpose: This study questioned the efficiency of daylight factor as a daylight adequacy and investigated a method of how to complement its weakness by considering a direct sunlight component under a clear sky condition. Method: The Snowdon visitor centre cafe was chosen as a case study building and various techniques such as BRE formula, BRE sky protractor, Pilkington dot diagram and mock-upscale model under the artificial sky simulator were used to analyse and compare daylight factor values. An analysis of direct sunlight component under the clear sky condition was carried out by Climate Consultant 5.5, sun path diagram, and the artificial sky simulator. Result: The result of daylight factor analysis differed by the adopted techniques and it was also contradictory to the results on a direct sunlight penetration. The result not only showed the limitation of daylight factor as a metric but also suggested an improvement by combining it with direct sunlight analysis. The techniques used in this study had a merit of being applied in the early design stage and thus be beneficial to many design professions in order for early daylight performance analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.134-135
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• 2015

This study was conducted to present basic improvement measures to improve the negative construction industry image of construction workers in the future, by investigating the construction industry images that construction workers have, through previous studies and analyzing the factors influencing these images, based on the multiple regression model. But this study is limited to construction workers and failed to establish specific improvement measures. Therefore, continued research which remedies the limitation of this study, will performed in the future.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.51-57
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• 2000

Cylinder machine usually gives more fiber orientation than fourdrinier and has limitation in machine speed because of fiber wash-off caused by centrifugal force when machine speed increases. This study aimed for the improvement of paper formation and productivity by setting an apron in vat inlet and by adjusting mould water head. Improvement of formation and increase of machine speed were achieved, which ultimately improve productivity. Installing an apron successfully decreased fiber wash-off. Fiber orientation and two-sideness of ash distribution became less severe. The proper adjustment of water head inside the cylinder mould proved to be an important factor not only in paper formation but also in decreasing paper two-sideness.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.17-17
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• 2002

There are considerable reports that the expression of insulin-like growth factor-Ⅰ (IGF-Ⅰ) is related to ovarian regulation and oviductal development in poultry. Korean Native Ogol Chicken (KNOC) have been inbred to keep a pure line so that there has been limitation in the improvement of egg productivity by genetic studies. Therefore, this study was conducted to investigate the early egg productivity of KNOC pre-selected by IGF-Ⅰ expression. (omitted)

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.70-76
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• 2017

The pollution problem of fossil energy sources has caused the development of green energy harvesting systems. Piezoelectric energy harvesting technology has been developed under those external environmental factors. A piezoelectric energy harvester can be defined as a device which transforms mechanical vibration or impact energy into electrical energy. Most researches have focused on bender structures. However, these have a limitation on energy efficiency because of the small effective electromechanical coupling factor, around 10%. Therefore, we should look for a new design for energy harvesting. A cymbal energy harvester can be a good candidate for the high-power energy harvester because it uses a high amplification mechanism using endcaps while keeping a higher electromechanical coupling factor. In this research, we focused on energy efficiency improvements of the cymbal energy harvester by changing the polarization direction, because the electromechanical coupling factor of the k33 mode and the k15 mode is larger than that of the k31 mode. Theoretically, we checked the cymbal harvester with radial polarization and it could obtain 6 times larger energy than that with the k31 direction polarization. Furthermore, we verified the theoretical expectation using the finite element method program. Consequently, we could expect a more efficient cymbal harvester with the radial polarization by comparing two polarization directions.

• Proceedings of the IEEK Conference
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• summer
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• pp.325-329
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• 2004

Linear size expanders have been studied in many fields for the practical use, which is possibility to connect large numbers of device chips in parallel communication systems. One major limitation on the efficiency of parallel computer designs has been the prohibitively high cost of parallel communication between processors and memories. Linear size expanders can be used to construct theoretically optimal interconnection networks. In current, the defined constructions have large constant factors, thus rendering them impractical for reasonable sized networks. This paper presents an improvement on constructing concentrators using an $(n,\;k,\;2rs/(r^2-s^2))expander,$ which realizes the reduction of the size in a superconcentrator by a constant factor.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.1
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• pp.99-108
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• 2012

The purpose of this study is to demonstrate the improvement of the education process in architectural engineering through the analysis of the advantages of the BIM tool. As public institutions and owners have been introduced to Building Information Modeling (BIM) tools, BIM has become an important factor in the design process in undergraduate university programs. First, BIM-related issues, domestic and overseas, was analyzed. Second, a case study of BIM education was analyzed at K University under the ABEEK process. Students participated a survey about the understanding of BIM and the use of BIM tools. As a result of the analysis, six advantages of the use of BIM tools were found. As a result of this research, following five issues are found about BIM education through advantage of using BIM tools. The result of this research was verified by conducting a survey on the usage of BIM softwares. The limitation of this study was to analyze the case study of only limited numbers of participants at the university.

• Journal of Fashion Business
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• v.8 no.1
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• pp.107-116
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• 2004

In the modern society, magazine is a information communicating media which is an important element in assessing the whole of a nation's cultural standard. More subdivided fields of magazines are expanding according to the diversified concepts. As the variety of Korean edition of foreign magazines are increasing, the type of Women's magazines are also diversifying and expanding. By finding out the problems and analyzing the visual side of domestic women's magazines among the intense competition of the magazines, the design improvement program was requested. The analysis result from the visual side of domestic women's magazines tells us that the problem of current domestic women's magazines is that their identities are not clear. The cause can be divided into three reasons: First, it is the lack of creativity and originality. There is a limitation in arousing the readers' interests by designing the magazines with similar layouts. Second, there are no distinct design concepts in the magazines. It seems as if the uniformity is lacked as the impression the magazine gives is not clear. The diversification of layouts and the use of design elements could actually bring about a counter result. Third, the excessive advertisement pages is another reason. The ads that covers over 35% of the whole of the magazine can act as a factor that drops the readers' trust in the magazine.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1412-1422
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• 2010

A bistatic radar using the pulse chasing can detect a target to track successive transmitted pulses using a receive beam for effectively scanning the cosite search area. When tracking a transmitted pulse with the receive beam, some beam pointing errors within pulse-to-pulse can cause the timing error in received pulse and the variation of the signal strength. In this paper, we have proposed that some errors due to the receive beam pointing error could limit the MTI filter's performance and derived that the relationship between the MTI performance and the geometric factors which are the inherent properties in bistatic configuration. Through the simulation, we have considered the limitations of the improvement performance restricted by the receiving beam pointing error and confirmed the contribution to the performance improvement in maintaining the receiving beam pointing error of under 0.5 degrees.