• Journal of Digital Convergence
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• v.15 no.8
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• pp.391-400
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• 2017

The purpose of this paper is to present the effect of image stimulation on body stability as a conceptual model and to investigate the effect of image stimulus(2D, VR) on body stability(hand stability) through experiments Recently, stereoscopic images such as virtual and augmented reality are combined with smart phones and exercise equipments, and the diffusion is becoming active. The possibility of a safety accident or human error is also increasing as it temporarily affects the balance of the body and hand stability after the image stimulus is removed. The conceptual model is presented based on the results of previous studies. Based on the experimental results, the conceptual model has been explained in combination with the human information processing process and cognitive resource models that take place in the brain. Twenty subjects were exposed to 2D and VR stimuli, and display fatigue was measured by cybersickness questionnaire and hand stability by hand steadiness tester. Experimental results show that VR images induce higher display fatigue and lower hand stability than 2D. In this study, it is meaningful that hand stability according to image type and display fatigue level which have not been tried yet is revealed through conceptual model and experiment.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.165-172
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• 2020

Heavy metals are common pollutants in the freshwater environment and have toxicological effect in habitat organisms. The heavy metals highly accumulated in sediment and organism, and observed various physiological responses. In this study, we investigated the molecular response to heavy metal toxicity (Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) through expression of heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450 (CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP). HSPs showed up-regulation in Cu and Zn exposures. Furthermore, HSPs expression in treated groups tended to be higher than the control group. The tendency of CYP450 and GST mRNA expression was higher for Cr and Cu than for other exposure group. The expression of SP gene was low at Al exposure and other group were measured to be similar to control. These results suggest that heavy metal toxicity in freshwater ecosystem may affect physiological and molecular process. Also, the comprehensive gene expression in the aquatic midge Chironomus riparius give useful information to potential molecular biomarkers for assessing heavy metal toxicity.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.259-264
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• 2014

This paper is research paper on the MPD(Magnet Position Device) for the outdoor MGV(Magnet /Magnet Gyro Guidance Vehicle). Usually, MGV is used in indoor environment because of a measurement height of the magnet position device. CMPD(Commercial magnet position device) has 30 mm measurement height, so this is suitable structure in indoor environment like to a flat surface. Outdoor environment is an uneven and irregular, So Outdoor MGV must has a suspension. But CMPD is unsuitable for outdoor environment because of a collision with a surface caused by suspension. Thus, measurement height of the outdoor MPD is positively necessary more than 100 mm. So, we suggest the outdoor MPD using analog magnet hall sensor, moving average filter and Characteristic(rate of the magnet hall sensor) function of the localization. Result of the experiments, the proposed Magnet Position Device for the outdoor MGV has localization accuracy 4.31 mm, measurement height 150 mm and width 150 mm and is efficient more than CMPD.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.179-198
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• 2011

The understanding of mathematical concepts should be backed up on a constant basis in oder to grow problem-solving skills which is one of the ultimate goals of math education. The purpose of the study was to provide readers with the information which could be considered valuably for the math educators trying both to prevent mathematical misconceptions and to develop curricular program by estimating the actual conditions and developing backgrounds of the mathematical misconceptions held by the gifted education learners. Accordingly, this study, as the first step, theoretically examined the meaning and the developing background of mathematical misconception. As the second step, this study examined the actual conditions of mathematical misconceptions held by the participant students who were enrolled in the CTY(Center for Talented Youth) program run by a university. The results showed that the percentage of the correct statements made by participant students is only 35%. The results also showed that most of the participant students belonged either to the level 2 requiring students to distinguish examples from non-examples of the mathematical concepts or the level 3 requiring students to recognize and describe the common nature of the mathematical concepts with their own expressions based on the four-level of concept formulation. The causes could be traced to the presentation of limited example, wrong preconcept, the imbalance of conceptual definition and conceptual image. Based on the estimation, this study summarized a general plan preventing the mathematical misconceptions in a math classroom.

• Informatization Policy
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• v.26 no.4
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• pp.36-61
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• 2019

While smart devices can have a positive impact on work efficiency and productivity by reducing time-space constraints and enabling rapid processing of tasks, side effects can arise from the imbalances between work and personal life. In recent years, as smart devices are increasingly used in work environments, it is more necessary than ever to understand the related phenomenon, find the cause of negative effects, and search for appropriate solutions. This study has developed and verified a theoretical model that shows how the technical characteristics known as the utility of smart devices are converted into negative results such as work-life conflict. As a result of analyzing the collected data from the employees, our study provides significant implications for the researchers, as well as the practitioners and policy makers, regarding various relationships among IT-enabled work flexibility, after-hours work connectivity and work-life conflict, and the new knowledge about the important role of segmentation supplies from the organization.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.19-32
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• 2016

Due to the increasing fiscal burden and structural unbalanced premium/benefit costs, the new reform on the government employees pension system (GEPS) was considered even after the recent reform in 2009. This article examines the various effects of recent amendment in 2015 on GEPS using a simple probabilistic model. We consider effects on both sides, the pensioners and the government. First of all, the expected net value of pension payment for an individual employee was calculated based on the supposed survival distribution. The fairness of individual pension holders was compared using the benefit-cost ratio. Secondly, from pension system users' point of view, the default probability and the government subsidy were examined by Monte-carlo simulation. From the simulation experiment, we could see that the 2015 reform plan indeed reduces the default probability and the size of the fiscal burden of government by increasing the premium and decreasing the benefit. However, the size of the effect is not very standout at this moment because the number of new employees who are fully subject to the reform will be much smaller than the number of previous employees for a while. Thus, the effect of the reform is expected to appear in a slow manner.

• KDI Journal of Economic Policy
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• v.14 no.2
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• pp.155-187
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• 1992

The Korean economy has sustained high growth rate for almost three decades, that have been associated with the rapid expansion of manufacturing industries. In the beginning stage of development, the high growth of the Korean economy has been based on improvements in productivity obtained by the economies of scale. In that period, the improvements in productivity could be secured by the economies of scale in the export-oriented industries which are the labor- and material-intensive industries. In the latter half of the 1980s, the Korean economy went through rapid transition. Now Korea is at another juncture in its development process, where economic restructuring is critical to sustain high growth. However, economic restructuring in the 1990s call for much more concerted effort than before, since changes in internal and external conditions have profoundly altered the environment for economic development. If Korea is to sustain high growth in the 1990s, it has to promote balanced economic and social development in coordination with the smooth facilitation of industrial restructuring. There are no inherent conflicts among the issues involved, so they can be resolved by restructuring the economy to facilitate, in a global context, the development of knowledge- and technology-intensive activities and to ensure that the benefts of growth are reflected of qualitative improvements in national living standards. In this paper, we examined a scenario of structural changes using a mid- and long-term multisector model, in order to understand the conditions needed for realizing the growth potential. This examination explains the important features of the development course and policy directions that will help sustain high growth in the 1990s.

• Management & Information Systems Review
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• v.36 no.3
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• pp.89-111
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• 2017

The era of today's day is that the era of the black gold age is now approaching the era of the blue gold age. As the importance of water increases, support and policies for the water industry are presented. The water industry is a public service industry but it faces the problem for unbalanced supply between users. One of solutions for solving the problem at hand is the privatization of the public service and it is the most sensitive and focused subject to the issue. Korea is also coming up for the privatization of the water industry. So, one of the privatization operations based on the privatization of the current waterworks law is management contract by the specialized organization and it is in progress to enhance the efficiency of public services. Therefore, this study aims at finding out the local water supply services' efficiency by K-Water using DEA(Data Envelopment Analysis), and productivity analysis by malmquist index on 18 organizations of the implementation of local water supply management contract using the date from 2012 to 2014. According to the result of the DEA, 10 of the 18 organizations were the most efficient during 3 years and malmquist index for analysing the productivity was decreasing. That is because of the leakage ratio and utilization ratio of the raw water and both of them are significant to productivity. As a result, this study differs from the previous studies by analysing efficiency and productivity using DEA and malmquist index to the solution for the problem faced by current water industry.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.3
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• pp.188-194
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• 2008

In this paper, we propose for improving QoS in Hospital wireless network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it has its vulnerability in frequent handoff environment. This handoff state machine using differentiated handoff improves quality of services in Cellular-IP/PRC Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and moat of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.743-754
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• 2017

Assessing bioequivalence between original drug and generic drug is traditionally based on $2{\times}2$ crossover design. As bioequivalence trials for highly variable drugs are getting popular, the required sample size based on $2{\times}2$ crossover design would be very large, which might cause the ethical concerns. Regulatory agencies like EMA and MFDS recommended higher order crossover designs such as $2{\times}4$, $4{\times}2$ and $4{\times}4$ crossover designs. Alternatively, a $2{\times}3$ dual design may be recommended in terms of economical and ethical points of view in comparison with the $2{\times}4$ crossover design for highly variable drug. In this study, we consider some statistical characteristics of $2{\times}3$ dual design and propose statistical procedures for calculating sample size and assessing bioequivalence based on $2{\times}3$ dual design. We also discuss the proposed procedures from the perspective of newly revised bioequivalence guidance issued by MFDS.