• 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.

• Korean Journal of Community Nutrition
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• v.25 no.3
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• pp.226-235
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• 2020

Objectives: Decreasing muscle strength in old age has become a significant health problem because it increases the risk of falls or fractures and transfers to other diseases. The precise role of dietary protein intake in preventing or reducing muscle weakness is unclear. This study examined the relationship between handgrip strength and protein intake in Korean female elderly. Methods: This was a cross-sectional study that used data from the Seventh Korean National Health and Nutrition Examination Surveys (KNHANES) on female subjects aged 65 years and older. Low handgrip strength (LHGS) was defined as a handgrip strength below than 18 kg. Dietary intake data were obtained using the 1-day 24-hour recall method. Multiple regression was performed to test whether there is an independent relationship between the grip strength and protein intake, and the association between protein intake and LHGS was confirmed through multiple logistic regression. Results: The mean age of the 2,083 elderly females was 73.3 ± 0.1 years, and the prevalence of LHGS was 35% (n=734). Elderly women with an LHGS consumed less energy, total protein, and animal-based protein than those in the normal group. A multiple regression analysis after adjusting for covariate revealed a significant positive association between the handgrip strength and energy, protein, and animal-based protein intake. Multiple logistic regression analysis showed that the odds ratio (OR) of LHGS in female elderly with the highest quartiles of consumption of energy [OR, 0.65; 95% confidence interval (CI), 0.43-0.82; P for trend=0.004], and animal-based protein [OR, 0.59; CI, 0.40-0.87; P for trend=0.037] were significantly lower than those in the lowest quartiles. Conclusions: The energy intake and animal-based protein intake were negatively associated with the LHGS. These results suggest that adequate energy intake and protein intake, particularly those from animal-based sources, for elderly women in Korea are beneficial in lowering the risk of LHGS.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.1-11
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• 2020

Medium to large post structures installed along the roadside without proper protection can lead to serious vehicle damage and occupant injury at the impact. In North America and Europe, splitting systems such as slip base or breakaway device are used to reduce impacts. But the system has the risk of secondary accident when the splitted post falls down to the traffic or pedestrian. Sliding Post have been proposed as a way to solve this problem. By studying the crash test results of the 1.3ton and 0.9ton vehicle with 60 km/h and 80 km/h to a Rigidly Fixed Post (RFP) and Sliding Post (SP), danger of the conventional RFP and crashworthiness of the SP have been proven. While collision analysis only from the acceleration measured at the center of the vehicle assumes the motion of the post is the same as that of the vehicle, in this paper, by adding high speed film data to the analysis with vehicle acceleration could have separate the post motion from the vehicle motion. It gives better explanations on the movement of post and vehicle in each distinctive time step and provides basics to the crashworthy post design.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.95-105
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• 2016

Recently the problem of child abuses has become a big social issue. According to national statistics data portal, the population under 19 years old is shrinking trend, but the number of child abuse is increasing day ever. However, the number of counseling after calling is a constant level without large fluctuations. Due to the seriousness of the problems, child abuse is even worse despite the research and countermeasures. This study designed a study model on the child abuse based on a preliminary study and suggested plans for reducing child abuse through the big data analytics. When we see a result of test of the hypothesis, abuse actor characteristics, characteristics of children, and employment type were analyzed to have a significant impact on child abuse. Based on such analysis, this research has suggested ways to reduce child abuse, including educational and economic support measures.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.20-30
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• 2017

Due to the evolution of wireless communications technology, Long Term Evolution (LTE), which is a $4^{th}$ generation mobile communications system, has been adopted as a railway communications system. This LTE Railway (LTE-R) system is composed of various elemental functions, which are largely categorized into public safety and wireless communications for train control. Research on the public safety functions of railway communications have their roots in TRS based national public safety communication systems, and research on wireless communications functions for train control have their roots GSM-R, which is utilized by the ETCS in Europe. Based on these circumstances, this paper first analyzes the requirements for developing public safety technology in LTE-R, and compares those requirements with the functions of public safety LTE (PS-LTE), which is being deployed for the first time in the world by the South Korean government. Based on an analysis of the common and specific functions of LTE-R and PS-LTE, we conclude that there is little problem in integrating LTE-R and PS-LTE from the perspective of functionality. Second, this paper provides a comparison of the LTE-R requirements for the Quality of Service (QoS) with those of GSM-R utilized by the ETCS. This offers a guideline to allow LTE-R to be applied to a 500km/h train control system.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.33-42
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• 1997

It is not long since treatment of food waste became a social problem. However, it is a fact that there have been a lot of debates on the treatment of food waste since several years ago. At present, two ways of disposing food waste are under great interest in Korea and Japan. One is drying of food waste at high temperature. The other is disappearance type, in which analysis by microorganism takes place with continuous supply of a bulking agent for a certain period of time that was stored in a reactor. In our laboratory, Disappearance type Food Waste Disposer is under interest, and experiments regarding condition establishment for efficient analysis of food waste were conducted. As preceding experimentation, experiments were done with regard to the selection of a substance to be used as a bulking agent, improvement by addition of a substance which maximizes initial growth of microorganism, and a concentration change in rank odors generated by reaction with deodorizer (absorbent). The results turned out to be satisfactory.

• Journal of KIISE
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• v.44 no.2
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• pp.139-147
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• 2017

Most of the information prevailing in the Internet space consists of textual information. So one of the main topics regarding the huge document analyses that are required in the "big data" era is the development of an automated understanding system for textual data; accordingly, the automation of the keyword extraction for text summarization and abstraction is a typical research problem. But the simple listing of a few keywords is insufficient to reveal the complex semantic structures of the general texts. In this paper, a text-visualization method that constructs a graph by computing the related degrees from the selected keywords of the target text is developed; therefore, two construction models that provide the edge relation are proposed for the computing of the relation degree among keywords, as follows: influence-interval model and word- distance model. The finally visualized graph from the keyword-derived edge relation is more flexible and useful for the display of the meaning structure of the target text; furthermore, this abstract graph enables a fast and easy understanding of the target text. The authors' experiment showed that the proposed abstract-graph model is superior to the keyword list for the attainment of a semantic and comparitive understanding of text.

• KDI Journal of Economic Policy
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• v.36 no.4
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• pp.135-169
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• 2014

This study empirically analyzes changes in production patterns of farmers by agricultural disaster insurance. The aim of this project is to achieve stability of farm management by paying insurance in case of a natural disaster. However, it causes farmers to change production patterns in the direction of increasing production, and leads the crop price to drop. This can be explained by producers' risk reduction through the disaster insurance. The empirical analysis is based on IV approach with using two stage least squares method. The first stage estimates by difference-in-differences methodology indicate that the production of insurable crops increases more about 80,000ton on average than that of non-insurable crops. In addition, to solve the endogeneity problem caused by general supply and demand model, I use the first stage estimates and find that the price index of the crops drops about 2.3% according to the production increase by 10,000ton. The credibility of these results is also attained by various robustness checks. These findings suggest that it is necessary for government to analyze the whole economy which consists of producer and consumer welfare when it determines the policy. Besides, it implies that it is essential to develop a new market to cope with the unintended effect.

• Informatization Policy
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• v.25 no.1
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• pp.30-59
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• 2018

The ICT policy domain is one of the most important policy domains in terms of national development and continuity. It is primarily because the contemporary society has been continuously developed and changed based upon the advanced information technologies. Recently, the Moon Jae-in Administration reorganized the Ministry of Science and ICT, and transferred a few of the key ICT related functions to other ministries as an attempt to develop the national ICT policies. However, critics in this domain argue that various problems still exist in the ICT policies in Korea. Therefore, the purpose of this research is to verify the empirical validity of the existing problems in the ICT policies in Korea, and develop alternatives to solve those problems. In order to serve the research purpose, this study employs multiple methods; a quantitative method which is a survey involving experts in ICT policies, and a social network analysis involving public officials in ICT related ministries. Research results show that the Korean government needs to enhance its capacity to make adjustments in ICT-related policies as the current decentralized system continuously creates various types of problems. The second possible solution to the problem is to change the national ICT policy system to a centralized one. However, this requires various efforts such as cooperation among ICT related government agencies, separation of ICT policies from science and technology policies, and increased government capacity to implement the ICT policies.

• Korean journal of communication and information
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• v.79
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• pp.40-69
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• 2016

This study examines how the Korean media has covered the leukemia case of Samsung workers. The news articles on the cases, published in the three terrestrial broadcasting stations, the five major newspapers, progressive Internet news media, conservative Internet news media, and business newspapers between 2007 and 2015, were retrieved and analyzed. Four characteristics of news reports were discovered as following: First, while conservative news media and business news media have exnominated the first phase of the case in which a civil organization Sharp claimed that Samsung workers had leukemia from their workplace; they have nominated the second phase of the case in which Samsung attempted to solve the problem by compensating the victims for their disease. Second, the media generally have displayed more interests in the results than in the causes of the case. Third, the conservative press and business newspapers have reported the case in favor of Samsung rather than laborer victims. Fourth, the conservative press have deployed market-friendly discourses, rather than problematizing the state and civil society. Through an abduktive analysis, this study argues that except the Hangyore and Kyunghyang Shinmun, most of the Korean media, assuming pro-business attitude, do not question or clarify where the responsibility of the industrial disaster lies by displaying their interests in the phase of solution, not in the phase of cause.