• Journal of the Economic Geographical Society of Korea
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• v.18 no.4
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• pp.556-572
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• 2015

Since the late 1990s dualistic spatial structure has been configurated in Icheon ceramic industrial space due to the articulation of transmitted ceramics space rooted from imitating the Goryeo and Joseon ceramics and contemporary ceramics space based on academic ceramic arts. Therefore, the main purpose of this paper is to identify the formation of dualistic space in Icheon by investigating the development paths of ceramic industry in historical perspectives and analyzing inter- and extra-firm relations in Icheon. The main results of this research are as follows. Firstly, the development path of transmitted ceramics has declined gradually, while the development path of contemporary ceramics has been embedded in Icheon region. Secondly, the research pointed out that networks of transmitted ceramics and contemporary ceramics are different in the perspectives of inter-firm and extra-firm relations. Thirdly, the government has played a critical role as a financial and administrative supporter and as a network broker between university and Icheon ceramic firms(mainly with transmitted ceramics) for technological cooperation and collaborative R&D.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.43-55
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• 2003

Workflow mining is a newly emerging research issue for rediscovering and reengineering workflow models from workflow logs containing information about workflows being executed on the workflow engine. In this paper, we proposed workcase mining which was used dependency among activities. Main purpose of this paper is to minimize discrepancies between the modeled workflow process and the enacted workflow process as it is actually being executed. That is, we can get a complete set of activity firing sequences on buildtime. Besides, we can discover from workflow logs that which path out of all reachable paths a workcase has actually followed through on runtime. For this purpose we proposed two algorithm, the one is 'Activily-Dependent Net Algorithm' and the other is 'E-Walk Series Analysis Algorithm'.

• Water for future
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• v.25 no.4
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• pp.61-73
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• 1992

There are needs to examine the consequences of a regulation in effect to control the migration of leachates from disposal sites. The main objective of this study is to illustrate the methodology to evaluate basic disposal designs for compliance with a certain regulation, The "100/100 rule" is selected for demonstration purpose which dictates that the time for the leachates to travel a horizontal distance of 100feet (30.5m) away from the property where the landfill or pond is located must exceed 100 years. The two primary methods for disposal of ash from coal-fired utility plants, landfill and pond, are studied, Numerical groundwater flow analysis resulted in pressure head distribution and flux information in the cross-section of the domain while path line analysis provided travel path and time of leachate migration to compliance zone.ance zone.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.2
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• pp.72-83
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• 2003

The main purpose of this study was to analyze the causal relationship, in the perspective of Total Quality Management, among the education quality factors, which were suggested in the previous researches, including education leadership, process improvement, educational environment, regional commitment, student performance and satisfaction of education quality. In this study, education quality factors were measured by several measures, and were processed with the most efficient statistical package in the SEM area, AMOS. In order to analyze the causal relationship among the education quality, this study designed the structural equation model with suggested factors and established several the research hypotheses. Also this study found that there was a prominent causality among the education quality factors, such as education leadership, education environment, student performance and satisfaction of education quality.

• Journal of Drive and Control
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• v.15 no.4
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• pp.11-16
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• 2018

Pilot operated control valve for $CO_2$ refrigerant is a valve that can perform various functions according to the user's intention by replacing pilot units, widely used for flow rate, pressure, and temperature control of refrigeration and air conditioning systems. In addition, $CO_2$ refrigerant, that requires high pressure and low critical temperature, can be installed and used in all positions of the refrigeration system, regardless of high or low pressure. In this paper, response characteristics are modeled and analyzed based on behavior of the main piston of the pilot-operated control valve. Although various factors influence operation of the main piston, this paper analyzes the effect of equilibrium pressure depending on valve installation position and application, and inlet and outlet orifice size of the load pressure feedback chamber to determine feedback characteristics of the main piston. As a result, it was possible to quantitatively analyze the effect of change in equilibrium and load pressure feedback chamber flow path size on the change in main piston dynamic and static characteristics.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.700-714
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• 2015

The characteristic of the water quality and pollutant discharge was analyzed at the units watershed of the total amount management in Han-river basin, and after classified in a similar area by multivariate statistical analysis, the main trend such as the water quality trend and pollutant discharge characteristic were analyzed. As a result of this study, the density of the pollutant at the unit watershed is not necessarily identified as discharge density, and the primary management watershed and targeted substances were analyzed depending on the operating status of the environmental infrastructure in watershed and the main pollution factor and discharge path per pollutants. As a result of cluster analysis, watersheds were classified into four groups according to discharge characteristics. It will be used when selecting target area of primary management that is appropriate to the characteristics of each river and establishing efficient water quality improvement plans.

• Korean Journal of Optics and Photonics
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• v.28 no.4
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• pp.153-157
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• 2017

An infrared camera and laser common-path optical system is applied to DIRCM (directional infrared countermeasures), to increase boresighting accuracy and decrease weight. Thermal effects of a laser beam in a common-path optical system are analyzed and evaluated, to predict any degradation in image quality. A laser beam with high energy density is absorbed by and heats the optical components, and then the surface temperature of the optical components increases. The heated optical components of the common-path optical system decrease system transmittance, which can degrade image quality. For analysis, the assumed simulation condition is that the laser is incident for 10 seconds on the mirror (aluminum, silica glass, silicon) and lens (sapphire, zinc selenide, silicon, germanium) materials, and the surface temperature distribution of each material is calculated. The wavelength of the laser beam is $4{\mu}m$ and its output power is 3 W. According to the results of the calculations, the surface temperature of silica glass for the mirror material and sapphire for the lens material is higher than for other materials; the main reason for the temperature increase is the absorption coefficient and thermal conductivity of the material. Consequently, materials for the optical components with high thermal conductivity and low absorption coefficient can reduce the image-quality degradation due to laser-beam thermal effects in an infrared camera and laser common-path optical system.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.2
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• pp.35-56
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• 2018

This study examines the current state of library related data opened through public data portals, and analyzes how much data is being utilized according to the type of releasing organization, and open level. In addition, we analyzed the subject cluster of data and the centrality of data by performing PathFinder Network analysis using keywords assigned to data by dividing the releasing subject into local government and national/public institutions. Based on this, the subject area of library - related data disclosed by local governments and national/public organizations is understood. And identify the main open body that should be opened first by linking with data utilization analysis result and then suggest implications for future improvement in connection with library big data business.

• Journal of Power Electronics
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• v.19 no.2
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• pp.403-412
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• 2019

Aiming at the problems of large dv/dt and di/dt in traditional single-ended converters and high electromagnetic interference (EMI) noise levels, a single-ended isolated converter using the secondary resonance technique is proposed in this paper. In the proposed converter, the voltage stress of the main power switch can be reduced and the voltage across the output diode is clamped to the output voltage when compared to the conventional flyback converter. In addition, the peak current stress through the main power switch can be decreased and zero current switching (ZCS) of the output diode can be achieved through the resonance technique. Moreover, the EMI noise coupling path and an equivalent model of the proposed converter topology are presented through the operational principle of the proposed converter. Analysis results indicate that the common mode (CM) EMI noise and the differential mode (DM) EMI noise of such a converter are deduced since the frequency spectra of the equivalent controlled voltage sources and controlled current source are decreased when compared with the traditional flyback converter. Furthermore, appropriate parameter selection of the resonant circuit network can increase the equivalent impedance in the EMI coupling path in the low frequency range, which further reduces the common mode interference. Finally, a simulation model and a 60W experimental prototype of the proposed converter are built and tested. Experimental results verify the theoretical analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1709-1715
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• 2021

In order to accurately extract the necessary text from the web page, the method of specifying the tag and style attributes where the main contents exist to the web crawler has a problem in that the logic for extracting the main contents. This method needs to be modified whenever the web page configuration is changed. In order to solve this problem, the method of extracting the text by analyzing the frequency of appearance of the text proposed in the previous study had a limitation in that the performance deviation was large depending on the collection channel of the web page. Therefore, in this paper, we proposed a method of extracting texts with high accuracy from various collection channels by analyzing not only the frequency of appearance of text but also parent tag paths of text nodes extracted from the DOM tree of web pages.