• Journal of Korea Water Resources Association
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• v.40 no.10
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• pp.769-781
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• 2007

Factor analysis has been usually employed in reducing quantity of data and summarizing information on a system or phenomenon. In this analysis methodology, variables are grouped into several factors by consideration of statistic characteristics, and the results are used for dropping variables which have lower weight than others. In this study, factor analysis was applied for extracting primary factors influencing multi-dam system operation in the Han River basin, where there are two multi-purpose dams such as Soyanggang Dam and Chungju Dam, and water has been supplied by integrating two dams in water use season. In order to fulfill factor analysis, first the variables related to two dams operation were gathered and divided into five groups (Soyanggang Dam: inflow, hydropower product, storage management, storage, and operation results of the past; Chungju Dam: inflow, hydropower product, water demand, storage, and operation results of the past). And then, considering statistic properties, in the gathered variables, some variables were chosen and grouped into five factors; hydrological condition, dam operation of the past, dam operation at normal season, water demand, and downstream dam operation. In order to check the appropriateness and applicability of factors, a multiple regression equation was newly constructed using factors as description variables, and those factors were compared with terms of objective function used in operation water resources optimally in a river basin. Reviewing the results through two check processes, it was revealed that the suggested approach provided satisfactory results. And, it was expected for extracted primary factors to be useful for making dam operation schedule considering the future situation and previous results.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.48-56
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• 2010

Recently, we need to dramatically speed up real-time video encoding and decoding on mobile devices because complexity of video CODEC is significantly increasing along with the demand for multimedia service of high-quality and high-definition videos by users. A variety of research is conducted for parallelism of video processing using newly developed multi-core platforms. In this paper, we propose a method of parallelism based on slice partition of video compression CODEC. We propose a novel concept of a parallel slice for parallelism and propose a new coding order to be adequate to the parallel slice which keeps high coding efficiency. To minimize synchronization time of multiple parallel slices, we also propose a synchronization method to determinate whether the parallel slice could be independently decoded or not. Experimental results shows that we achieved 27.5% (40.7%) speed-up by parallelism with bit-rate increase of 3.4% (2.7%) for CIF sequences (720p sequences) by implementing the proposed algorithm on the H.264/AVC.

• Journal of Technologic Dentistry
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• v.37 no.4
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• pp.271-284
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• 2015

Purpose: The purpose of this study was to examine the usage of CAD/CAM, which is one of dental technologist duties, in an effort to look for any possible changes in the usage of CAD/CAM. It's specifically meant to compare the results of this study with those of Lee Jong-do, Park Kwang-Sig(2011)'s study in March, 2011, to determine if there were any changes over the past four years. The selected variables that were investigated were the ownership of CAD/CAM, awareness of it, the route of acquiring the first information on it, the merits and demerits of its usage, usage experience and educational experience about it. Methods: An online survey was conducted on the dental technologists who worked in urban communities including metropolitan cities to find out the usage of CAD/CAM in 2015 from July 15 to 31, 2015, after existing questionnaire items were modified. The collected data were analyzed by IBM SPSS statistics 22.0, and statistical data on frequency, percentage, mean and standard deviation for each item were obtained. To figure out the characteristics of the subjects and the relationship between their occupational characteristics and the usage of CAD/CAM, crosstabs, independent-samples t-test and one-way ANOVA were utilized. As for the usage of CAD/CAM in 2011, the results of Lee Jong-do, Park Kwang-Sig(2011)'s study were selected, and then a comparative analysis was made. The level of significance was all set at .05. Total 250 questionnaires were distributed to them, and 190(76.0%) were returned. After excluding 23 whose answers were uncertain or seemed to lack reliability, total 167(66.8%) were used in final analysis. Results: As a result of analyzing the usage of CAD/CAM that was one of dental technologist duties, there was a great increase in the ownership of CAD/CAM in their workplaces from 2.4 percent in 2011 to 71.7 percent in 2015, and there was an improvement in awareness about it and the necessity of its usage as well. In 2011, the Internet and mass media were the most common route that they got to know about it. They had a strong tendency to acquire related knowledge through education in 2015, and there were some changes in the products that they used or preferred. In both years, the great merit of CAD/CAM was the simplified manufacturing process of restoration, and it had another great advantages in 2015 such as the improved quality of restoration or improved environments for dental technology. Concerning disadvantages, high price was a big problem in 2011. In 2015, not only price but the burden of material costs, frequent breakdown, poor demand among dental clinics and a lack of CAD/CAM professionals were pointed out a lot. In the future, this researcher intends to make research to seek ways of improving CAD/CAM professionals. Conclusion: There was more awareness of CAD/CAM in 2015 than in 2011 when the changes in awareness of it were analyzed, and the finding suggest the necessity of sustained education and concern.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.61-69
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• 2016

Since 2000, the market of convenient stores in Korea has developed rapidly due to the explosive growth in single households but it still consists mainly of manual work due to the nature of the domestic industry. Hence the explosive increase in demand in the market is mostly due to workers. Therefore, the research aimed at encouraging efficiency via automation, which is carried out in manufacturing, such as electronic, cars and so on, is inadequate. This study performed a feasibility analysis of investment for introducing an automated system on brand A, which is domestic famous convenience store company. Productivity growth according to the introduction of an automated guided vehicle and the cost-benefits was studied with using a simulation for the picking process, which is most personnel and time consuming. As a result, the simulation showed that the equipment AGV introduced for choosing the process has the effects of cost saving and increased time efficiency for performing manual labor. Furthermore, appropriate numbers of AGV were forecasted considering the capacity of the distribution Center in the brand A convenient store, which has been growing steadily. There are increasing numbers of worker labor costs in the distribution industry these days. Before building a large new automate center, it is expected to provide a good information to investors who are considering increasing productivity through partial automation of each of unit process to achieve some cost reduction.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.461-476
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• 2009

Digital Printers that are mainly used in enterprises and public institutions are compound machinery and tools which are combined into various functions such as printing, copying, scanning, and fax so on. Digital Printers has security functionality for protecting the important data related with confidential industry technology from leaking. According to the trends, CC(Common Criteria) evaluation and assurance about digital printer is on progress in Japan and USA. Domestically CC evaluation and assurance is started recently. However, the know-how about the digital printer evaluation is not enough and the developers and the evaluators have difficulty in CC evaluation of digital printer products in the country. Therefore, the testing method of digital printer security functionality and evaluation technology is essentially needed for increasing demand for the evaluation afterwards. In this study, we analyze the security functionality and developing trends of digital printer products from internal and external major digital printer companies. Moreover, we research the characters of each security functions and propose guideline for digital printer security functionality evaluation and vulnerability testing methods.

• Journal of Korea Port Economic Association
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• v.36 no.3
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• pp.55-74
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• 2020

With globalization and the development of information and communication technology, the supply chain is becoming more widespread and complex, which increases the occurrence and damage caused by supply chain risks. Supply chain risk management has a great impact on corporate performance through the analysis of risk factors and proactive and strategic approaches. This study aims to analyze the effects of supply chain risk factors on risk management strategies and corporate performance empirically. In the research model for empirical analysis, supply chain risk factors were classified into supply, demand, operation, network, and external environment, while the risk management strategies were divided into active and passive strategies, as well as financial and operational performance for corporate performance. The data obtained via the questionnaire were analyzed for the path of the structural equation model. As a result of the analysis, companies are actively pursuing risk management for internal risk factors, rather than external factors, in terms of internal and external risk factors, and it was found that these strategies have a significant effect on corporate performance. Therefore, in the future, companies should conduct risk management strategies more proactively and preemptively through a thorough analysis of various risk factors affecting business operations.

• Journal of Distribution Science
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• v.13 no.3
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• pp.69-77
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• 2015

Purpose - The purpose of this study is to examine whether the cash policies of retail firms listed on Korean stock markets are consistent with the evidence provided in the study of Almeida et al. (2004). Liquidity management is an important issue for financially constrained firms relative to financially unconstrained firms. Because there are few sources of external funding, the optimal liquidity policies of financially constrained firms should reflect their own earnings or cash inflows to create opportunities for current and future real investments. According to this simple idea, we estimate the sensitivity of cash to cash flows and simply check whether the estimated sensitivity to cash flows of the cash retained by constrained retail firms is greater than that of the cash retained by unconstrained retail firms. Through this work, we aim to explain why the cash policies of the retail firms listed on the Korean stock markets differ from those of listed manufacturing enterprises. Research design, data, and methodology - To explain a firm's cash holdings, we use only three explanatory variables: earnings before interest and taxes (EBIT), Tobin's q, and size. All the variables are defined as the value of the numerator divided by aggregate assets. Thanks to this definition, it is possible to treat all the sample firms as a single large firm. The sample financial data for this study are collected from the retail enterprises listed on the KOSPI and KOSDAQ markets from 1991 to 2013. We can obtain these data from WISEfn, the financial information company. This study's methodology has its origin in Keynes's simple idea of precautionary liquidity demand: When a firm faces financial constraints, cash savings from earnings or cash inflows become important from the corporate finance perspective. Following this simple idea, Almeida et al. (2004) developed their theoretical model and found empirical evidence that the sensitivity of cash to cash flows varies systematically according to different types of financing frictions. To find more empirical evidence for this idea, we examined the cash flow sensitivity of the cash held by Korean retail firms. Results - Through several robustness tests, we empirically showed that financially constrained Korean retail firms display significant positive propensity to save cash from earnings before interest and taxes, while the estimated cash flow sensitivity of the cash held by unconstrained retail firms is not significant. Despite the relatively low earnings of retail firms, their sensitivity is three times greater than that of manufacturing enterprises. This implies that Korean retail firms have greater intentions of facilitating future investments rather than current investments. Conclusions - The characteristics of the cash policies of Korean retail firms differ from those of manufacturing firms. This contrast may be attributable to industry-oriented policy planning, regulations, and institutional differences. However, the industrial policymakers should observe signals of the long-term growth options of retail firms based on their high propensity to save from their cash inflows.

• Journal of Environmental Impact Assessment
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• v.13 no.3
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• pp.125-135
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• 2004

Environmental Impact Assessment(EIA) in Korea has been used to improve environmental conservation and decision-making. Since environmental impact statement(EIS) was introduced in 1981 with the promulgation of the Environmental Preservation Act in 1977, which replaced the Pollution Control Act legislated in 1963. With a rapid growth of environmental perception as well as the diversification of development activities, however, it has recently bring about a strong demand for a new assessment process related to the strategic level of policies, plan, programs. Method of this study includes analyses of the situation of local EIA and its problematic issues through survey and analysis of information and data, analysis of the level of environmental awareness of professionals and case studies including analysis of foreign strategic environmental assessment. Accordingly, I have elicited a concept of SEA. In addition, I have studied on costs of environmental assessment, and efficiency of internalization of HIA. The survey was carried between September and November 2003, and 177 professionals were asks to complete a questionnaire. As a result of questionnaire survey of environmental pundits, it revealed that 83.8% of participants were in favor of introduction of strategic assessment. This result demonstrated more or less higher approval rate than those of awareness survey done by the Ministry of Environment, i.e. 86.0% ayes, and 14.0% nays. 22.8% of participants agreed to the opinion; "For introduction of this system, earlier is better," 50% reported having an opinion such as, "Will introduce this system in an earliest possible time after correcting problems," 26.3% reported having an opinion such as, "Let's decide the time for introduction of this system after correcting problems first,' and 0.9% reported having an opinion, "it's too early to introduce this system." Specifically, the ratio of ayes on introduction of the system marked 72.8%, and it revealed that a majority of respondents have an opinion such as, "Will introduce this system in an earliest possible time after correcting problems." As means of solutions for the problem regarding the limits of applications that existed in SEA System, factors, such as collecting a wide variety of opinions, securing experts, and faithful implementation, etc. were reported important, and in addition to these factors, respondents revealed having opinions such as, consistent research and development, reflection of public interest, establishment of professional organization, enforcement of after-management service, expanding investments in large, systemizing reference materials, and encouraging public participation, etc. To improve problems involving with present EIA system, it has been identified through this study that SEA is efficient and useful. In order to have SEA introduced successfully, it has been cleared that internalization of effectiveness of environmental cost together with HIA must be accomplished.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.71-81
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• 2020

Family companies are the unique industry-academic cooperation-related systems of Korean universities created by universities to promote various forms of industry-academic cooperation with companies. It is important to figure out the current status of family companies in order to understand the achievements of industrial-academic cooperation projects that have been actively pursued since the early 2000s. A lot of studies on industry-academic cooperation have focused mainly on the university's position. On the contrary, this study focuses on understanding the current status of the family company system and the status of industry-academic cooperation. Introduced in 2004, the Family Company System expanded rapidly as it was used as a performance indicator for college financial support projects related to industry-academic cooperation, with 174,425 companies registered as family companies as of 2017. A survey of family companies registered in universities carrying out the LINC+ project shows that companies registered in multiple universities are increasing, with relatively high demand and satisfaction for industry-academic cooperation among companies. Family companies were found to be relatively satisfied in terms of the use of R&D equipment or joint research, while they were relatively less satisfied in terms of workforce training and retraining. While companies have assessed product quality improvements through industry-academic cooperation, they have underestimated the effect of increasing sales and reducing production costs. Further, it was found that it was urgent to expand incentive systems and improve online information services to boost corporate participation in order to enhance the effectiveness of industry-academic cooperation.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.475-487
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• 2011

Objectives : The growing elderly population and social changes have fueled a rapid increase in demand for elderly care facilities, but health care services for the elderly, especially oral health services, have long been overlooked. The purpose of this study was to examine the oral health care of elderly residents in elderly care facilities in an effort to provide some information on the elderly's oral health care and the development of dental care programs geared toward institutionalized elderly people. Methods : The subjects in this study were 230 elderly people who were in elderly care facilities in Jeolla Province. An individual interview was held, and they got a dental checkup. As for data analysis, t-test and ANOVA were utilized, and Scheffe post-hoc test was employed. Results : 1. In relation to the subfactors of the quality of life related to oral health, the elderly people investigated got a mean of 4.58, 4.47, 4.38, 4.09, 3.94, 3.91 and 3.76 respectively in activity disorder, mental disorder, social disorder, mental inconvenience, functional disorder, physical pain and physical disorder. 2. Concerning the overall quality of life related to oral health, there were statistically significant gaps in this aspect according to gender, age, presence or absence of systemic disorder, presence or absence of eating difficulties, subjective health status, subjective oral health state and oral health concern. 3. The presence or absence of root caries had a significant relationship to physical pain and social disorder among the subfactors of the OHIP-14, but that had nothing to do with functional disorder, mental inconvenience, physical disorder, mental disorder and activity disorder. Conclusions : The oral health indexes of the institutionalized elderly people in Jeolla Province were measured, and what factors affected the subfactors of oral health was checked. As a result, there appeared a close relation ship between oral health and the quality of life. Therefore effective oral health plans that cater to the elderly should be carried out to improve elderly people's quality of life related to oral health who stay in long-term elderly care facilities. In the future, prolonged research should be implemented from diverse angles for the sake of institutionalized elderly people.