• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.328-329
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• 2020

The AC/DC converter, which connects the AC grid to the DC grid in the microgrid, is a critical component in power sharing and stable operation. Sometimes the AC/DC converters are connected in parallel to increase the transmission and reception capacity. When connected in parallel, circulating current is generated due to line impedance difference or sensor error. As a result of circulating current, there is deterioration and loss in particular PCS(Power Conversion System). In this paper, we propose droop control with novel adaptive virtual impedance for reducing circulating current. Feasibility of proposed algorithm is verified by PowerSIM simulation.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.505-512
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• 2016

The paper is concerned with high frequency financial time series. A weighted hybrid volatility is suggested to compute daily volatilities based on high frequency data. Various realized volatility (RV) computations are reviewed and the weights are chosen by minimizing the differences between the hybrid volatility and the realized volatility. A high frequency time series of KOSPI200 index is illustrated via QLIKE and Theil-U statistics.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.634-639
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• 2001

Central anticholinergic syndrome is defined as an absolute or relative reduction in cholinergic activity in the central nervous system and has a wide variety of manfestations. It is associated with almost any drug given during anesthesia, except neuromuscular relaxants, and treated with the cholinesterase inhibitor physostigmine. The diagnosis of central anticholinergic syndrome is often made when symptoms resolve promptly after the administration of physostigmine. We present a case of a central anticholinergic syndrome diagnosed by treatment with physostigmine, in a patient who received closure of patent foramen ovale associated with stroke.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.7
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• pp.165-174
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• 2018

The purpose of this study is to verify the effects of R&D process maturity on product development performance and to verify whether R&D project performance mediating effect. The questionnaire was collected and analyzed to 131 persons related to the R&D work in 55 companies and public institutions performing R&D work. The results of this study are as follows, the effect of R&D process maturity on product development performance and mediating effect of R&D project performance were analyzed by simple and multiple regression analysis. Regression analysis was analyzed by SPSS statistical program. The higher the maturity level of the R&D process, the higher the product development performance and the R&D project performance, and the R&D project performance is partially mediated. It is concluded that it is important to establish and operate a systematic R&D process and to develop a project management methodology suitable for the characteristics of a company in order to improve product development performance. It is expected that if this study are utilized as practical R&D management methodology in corporate management, it will contribute to improvement of company product performance.

• Journal of Labour Economics
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• v.35 no.2
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• pp.1-24
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• 2012

This paper analyzes the wage structure of college professors in private institutions in Korea. An analysis of earning functions reveals that the human capital of the professors is of more general type rather than firm-specific one. It is also found that the wage differential among colleges is far greater than that within colleges. Finally, the influence of research output or the fields of study on wage is found to be small. This shows that compensation for professors is set largely independent of individual performance or labor market conditions for professors.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.13-19
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• 2021

Fog is a phenomenon caused by condensation of water vapor in the atmosphere, which is when very fine drops of water float in the atmosphere and the distance of visible is less than 1km. Fog dispersion technology is a technology that removing or weakening fog by using artificial methods to reduce damage caused by fog. It is applied differently depending on the temperature of fog generation rather than the cause of fog. This study conducted an experimental study on the fog dispersion mechanism in order to minimize damage caused by fog on the road, and studied two methods of over-cooling dispersion using solid-carbon-dioxide as a dissipated particle and dissipating fog particles through thermal acoustic waves. As a result the two methods proved experimentally that were capable of dissipating fog.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.31-39
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• 2013

Smart TV is a television set with internet capabilities, computing ability, and broadcasting service that increases user interactions. Usability has been regarded as one of the most important criteria for measuring and evaluating smart TV. To evaluate smart TV from the perspective of usability, we first need to develop a measurement model by determining the major factors affecting usability, which become a measurement the evaluation criteria of the model. The objective of this paper is to suggest an AHP(Analytic Hierarchy Process) model for measuring usability of smart TV. Factors affecting usability are described from the prior research. We show how the judgment data is acquired and the usability score is computed by an numerical example.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.272-280
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• 2014

This study was researched by practical method in a subjectivity study accessible in-depth, in sloughing off old habit of functional quantity analysis about utility awareness of medical machinery. The perception pattern come out in this study were divided into three types in Q-methodology. The result is as follows ; it is that divided '1[(N=11) : Safety & Importance of Advertising 1], 2[(N=9) : Safety & Importance of Advertising 2], 3[(N=10) : Safety & Endurance]'. Like this, it found that is very different type all over. Hereafter, this study is to ascertain acceptance behavior about reception type on utility awareness of medical machinery ; to offer a developmental suggestion about it.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.947-952
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• 2007

The construction project is composed of individual trade which is consists of each activity. and the performance of each activity is the lowest level to influence the project performance. Consequently, It is essential to measure and evaluate the performance of the each assignment. But the existing performance measurement have mainly focussed on company level and project level. Therefore, this paper select PPC as the indicator of a activity and, suggests the analysis method of indicators for a goal-oriented management and continuous improvement through a statistical control techniques.

• Journal of Internet Computing and Services
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• v.16 no.5
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• pp.39-47
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• 2015

The centrality is calculated to describe the importance of a node in a graph and ranking is given according to the centrality for each node. There are many centrality measures and we use degree centrality, closeness centrality, eigenvector centrality, and betweenness centrality. In this paper, we analyze the effect of an additional edge of a graph on centrality and ranking through experimental computations. It is found that the effect of an additional edge on centrality and ranking of the nodes in the graph is different according to the graph structure using PCA. The results can be used for define the graph characteristics.