• Journal of the Korean Data and Information Science Society
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• v.26 no.5
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• pp.1061-1069
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• 2015

Recently, transportation big data generated in the transportation sector has been widely used in the transportation policies making and efficient system management. Bus passengers' mobility patterns are useful insight for transportation policy maker to optimize bus lines and time intervals in a city. We propose a new methodology to discover mobility patterns by using transportation card data. We first estimate the bus stations where the passengers get-off because the transportation card data don't have the get-off information in most cities. We then applies LDA (Latent Dirichlet Allocation), the most representative topic modeling technique, to discover mobility patterns of bus passengers in Cheong-Ju city. To understand discovered patterns, we construct a data warehouse and perform multi-dimensional analysis by bus-route, region, time-period, and the mobility patterns (get-on/get-off station). In the case of Cheong Ju, we discovered mobility pattern 1 from suburban area to Cheong-Ju terminal, mobility pattern 2 from residential area to commercial area, mobility pattern 3 from school areas to commercial area.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.274-282
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• 2013

The goal of this study was to analyze prevalence and distribution of congenitally missing teeth in 3302 patients from 7 to 15 years old, who had visited and taken panoramic radiographs at the Department of Pediatric Dentistry, from January 2008 to December 2012. The prevalence of hypodontia in the males (5.9%) was slightly higher than in the females (4.7%). In the affected patients, the mean number of congenitally missing teeth in the mandible was statistically higher than in the maxilla (p < 0.05). However, there was no significant difference in the number of congenitally missing teeth between left and right dentitions (p > 0.05). Excluding the Mn. third molars, the most frequent congenitally missing teeth site was the Mn. second premolars. In contrast, the most infrequent congenitally missing teeth sites were the Mx. and Mn. first premolars, and Mx. central incisors. The bilateral combination or antagonistic quadrants combination of congenitally missing teeth in hypodontia patients was 80.3%. The result of this study will contribute to clinicians to make accurate diagnosis and establish favorable treatment plans, by offering invaluable data about the number and distribution of congenitally missing teeth.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.473-481
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• 2017

With the barracks modernization project, the Ministry of National Defense has been operating 60 projects of the 75 that have been announced. It was difficult to investigate and analyze the data in the past because data could not be obtained while it was much easier to do that since data can be obtained from private companies. With the aim of increasing the usability of the facilities, the objective of this study is to present a reasonable alternative for repair and maintenance costs by investigating and analyzing the budget and the actual expenses of repair and maintenance of military facilities for the past 3 to 5 years, and then identifying the problems with these. To accomplish this, a theoretical review of previous studies and legal grounds related to repair and maintenance costs was performed, and data on the estimates and the actual expenses data used in BTL projects carried out by private companies were analyzed. First, one of the problems was that there are some items omitted, including consumables, and these items should be included in order to secure their budget. Second, in terms of the items for divided payments, two improvements had been presented: a short-term payment plan for the operation period of 3 to 5 years and a long-term payment plan for an additional and complemented period other than the operation period. The repair and maintenance costs should be further studied at the point of time in a future when the actual data on the costs and operation period of military facilities can be secured. This study is expected to serve as empirical data that will form the basis for a reasonable calculation of the construction cost for military facilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.44-52
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• 2019

Industrial accidents differ considerably according to the industry and the scale of these industries. These industrial disasters have been analyzed in various ways. Therefore, a technique was developed to evaluate the disaster level among companies using the ANP method and the data derived from the disaster statistics over the past five years(2013~2017), as well as the safety information characteristics through questionnaires. The objective of the study was to determine the disaster level and safety level of a company. In this paper, six factors that are considered important for assessing the disaster level of the enterprise among the disaster statistics were selected. These factors included the industry type and size, age of employee, duration of treatment, duration of employment, and typical occurrence. Most companies use the accident rate for their disaster level to compare only with other companies. In this study, the weighting factors of the company were derived taking the characteristics of each company into consideration. Therefore, the disaster level of each company can be evaluated using the disaster statistics from each company and the derived weighting factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.190-198
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• 2020

For domestic urban railways, which have a 19.7% aging rate, a performance evaluation is necessary to establish capital improvement investment plans. The performance evaluation, which was recently enacted in the relevant law, points out the excessive time and effort for acquiring data and evaluation. This study developed a performance evaluation simulation prototype using a virtual reality (VR) method to use as training contents for railway performance evaluations. The practical use of the VR technique to reduce the working time under poor environment conditions was confirmed through a literature review. A survey and consultation were conducted for urban railway experts to determine the weight of the performance evaluation items and the facility breakdown structure. This information was utilized to develop performance evaluation sheets for simulation. Based on the evaluation sheet, a training content prototype that evaluates the performance of platform safety doors was developed using VR techniques with HTC VIVE equipment. VR simulation tests were conducted for six players, and the prototype was sufficiently advantageous for a visual confirmation of the facility information. The result is expected to be useful for engineers to understand the performance evaluation process efficiently before an actual performance evaluation of urban railway facilities.

• Information Systems Review
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• v.18 no.2
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• pp.151-171
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• 2016

With the widespread adoption of mobile devices, such as smart phones and smart pads, as well as the rapid growth of mobile technologies, consumer shopping patterns are changing. This study investigates key factors of consumer purchasing intention in a mobile shopping mall context by incorporating trust belief into the theory of planned behavior. We posit perceived usefulness, perceived enjoyment, perceived ease of use, and trust belief as antecedents of behavioral attitude toward mobile shopping malls. Moreover, social influence and security are identified as key enablers of trust belief on mobile shopping malls. Data collected from 154 consumers with purchasing experience in mobile shopping malls are empirically tested against a research model using partial least squares. Analysis results show that behavioral attitude and perceived behavioral control significantly influence purchasing intention. Moreover, this study reveals the significant effects of perceived usefulness and perceived enjoyment on behavioral attitude. Trust belief indirectly influences purchasing intention through behavioral attitude and is significantly affected by social influence. Understanding consumer purchasing decision-making processes in mobile shopping malls can help service providers to develop effective marketing and operation strategies and campaigns.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.961-965
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• 2007

현재 오염총량관리제를 시 군 단위의 기초자치 단체별로 시행하고 있는데 실제로 오염물질의 전달은 행정구역단위가 아닌 유역내에서 이루어지진다. 따라서 본 연구에서는 기초자치 단체별이 아닌 유역단위로 오염부하량과 삭감량을 산정함으로써 유역 단위의 오염총량관리제 계획 수립을 위한 토대를 제공하고자 한다. 본 연구에서는 보청천 유역을 대상으로 유역의 오염부하량을 산정하고자 하였다. 이를 위하여 지리정보시스템(GIS)인 WMS(Watershed Management System)와 ArcView를 이용하여 유역의 지형인자들을 추출하고, 각 소하천의 토지이용도와 생활계, 축산계, 양식계, 토지계를 바탕으로 원단위를 적용하여 발생부하량을 산정하였다. 그리고 각 소하천별 발생부하량 산정 결과를 토대로 각 수질관측점을 기준으로 하여 배출부하량을 산정하였으며, 배출부하량의 산정결과를 이용하여 유달부하량을 산정하였다. 이를 위해서 필요한 수질 데이터는 QUAL2E 모형을 이용하여 모의 하였으며, 수리 및 수질 매개변수를 추정하고 모형의 보정 및 검증을 수행하였다. 그 결과 유달부하량은 BOD는 2013.16kg/일, TN은 1091.34kg/일, TP은 235.16kg/일이 도출되었다. 따라서 장래에 수질이 악화될 경우를 고려하여 수질 항목별 오염량이 2배, 3배로 증가한다고 가정하였다. 오염량이 2배 증가하였을 경우, 오염부하량을 산정한 결과 보청천3 지점에서 BOD는 184.68kg/일이 삭감되어야 하고, 오염량이 3배 증가하였을 경우 BOD는 1775.69kg/일이 삭감되어야 한다는 결과를 도출할 수 있었다. 본 연구와 같이 유역단위로 오염부하량을 산정할 경우, 오염원을 줄이는데 효율적일 것으로 생각되며, 향후 오염총량관리제를 위해 유역단위의 오염부하량 산정을 고려하면 좋을 것으로 사료된다.는 지배적인 요인으로 남게 될 것이다. 본 연구에서는 현재 진행중인 승기천 오염하천 정화사업이 종료되는 시점을 기준으로 남동유수지에 대해 승기천과 연계한 유수지의 환경개선 방법을 제안하였다. 준설을 통해 유수지의 근본적인 오염원을 제거하고 남동유수지 유입부에 인공습지와 수처리설비를 설치하여 유수지의 수질을 개선하고 개선된 수질이 3급수로 유지하도록 하였으며, 설치된 인공습지에는 철새도래지를 조성하여 유수지 유입수인 철새가 날아드는 하천인 승기천의 테마와 연계하도록 하였다. 인공습지 주변으로 식생호안을 설치하고 유수지 주변에는 산책로를 설치하여 지역주민들의 친환경 수변공간으로 활용하도록 하였다. 1유수지와 연결된 2유수지는 BTL사업을 통해 주변공단으로부터의 오폐수를 원천적으로 차단하도록 하였으며 2유수지를 매립하여 지하는 강우시 유출수 저류가 가능한 화물차주차장으로 활용하고 지상은 녹지공간으로 조성하여 공단근로자 및 지역주민을 위한 휴식공간으로 활용될 수 있도록 제안하였다. 본 연구는 남동유수지 환경 개선 사업 실행을 위한 정책 연구로 연구결과를 인천시가 적극 수용하기로 결정함에 따라 인천시의 환경 현안 문제인 남동유수지의 수질개선을 통해 시민의 휴식 및 여가선용 공간으로 활용하기 위한 사업의 기초자료로 활용되며 이미 설계검토가 시작되었다. 본 연구결과는 유수지 및 저수지의 환경개선 사업의 선두적인 성공사례로 국내 타 지역의 유사한 사업에 있어 벤치마킹을 할 수 있는 훌륭한 사례가 될 것이다.요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째, 경기도 광주에서 백자관요가 운영되었으므로 지방인 상주

• Phonetics and Speech Sciences
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• v.12 no.1
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• pp.65-74
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• 2020

This study aims to compare the acoustic characteristics of vowel phonation in children with spastic and dyskinetic cerebral palsy (CP). Thirty-four children aged 4-12 years with CP participated in the study (spastic 26, dyskinetic 8). Voice samples for the acoustic analysis were extracted from a sustained vowel /a/. All acoustic measures were made using Praat. Group differences were compared by an independent t-test or Welch-Aspin test, if the equivalence assumption was not met. The results of this study are as follow. First, maximum phonation time(MPT) was significantly shorter for the dyskinetic CP than for the spastic CP. Second, shimmer percent was significantly increased in the dyskinetic CP than in the spastic CP. Lastly, there were no significant group differences in both the first formant and the second formant. These findings indicate that the dyskinetic CP has a poorer respiratory capacity and poorer laryngeal function than the spastic CP. On the other hand, both groups have a comparable ability to articulate the vowel /a/. The results of the present study help speech language pathologists identify the speech motor control ability of children with two types of CP (spastic and dyskinetic) and help to make an intervention plan associated with a specific type of CP.

• Journal of The Korean Association For Science Education
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• v.38 no.5
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• pp.649-665
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• 2018

In this study, we extracted the core competencies of makers through the analysis of critical incident technique and behavioral event interview to explore the nature and attributes of maker education, and then we developed a maker competency model based on these core competencies. As a result, six competency groups and 23 sub-competencies were extracted. In other words, we were able to confirm the existence of integrated thinking competency group consisting of four competencies made up of 'analytic thinking', 'intuitive thinking', 'visual thinking', and 'empirical thinking' and that of collaborative competency group with four competencies of 'sharing', 'communication', 'conflict management', and 'scrupulosity'. In addition, we could also confirm the existence of making mind competency group, which is composed of four competencies namely 'interest in various areas', 'challenge consciousness', 'failure management', and 'pleasure of the making process'. We could also confirm that human-centered competence group consisting of two competencies of 'humanity' and 'user-oriented' and the problem-finding competence group consisting of two competencies of 'observation' and 'recognition of discomfort in daily life'. Lastly, the making practice competency group is composed of seven competencies: 'understanding making tool', 'understanding electricity', 'understanding programming', 'planning', 'hand knowledge', 'information search', and 'direct execution'. We discussed educational implications of these findings.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.248-253
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• 2015

This study applied the portfolio approach as a means to provide decision-making information for the establishment of the optimal production plan for non-timber products. The target items of non-timber forest product were Chestnut, Jujube, Walnut and Astringent Persimmon. The data used in this study were the annual report of forestry production cost survey which contains the annual production, annual gross income, and annual product cost from 2008 to 2013. These data were used to calculate the expected return of non-timber forest product. The objective function in the portfolio models was to minimize the expected return volatility, called risk and the constrain was to achieve the minimum expected return rate. Results indicated that the production ratio of the nuts and fruits in 2013 was 7% for Chestnut, 20% for Jujube, 5% for Walnut and 68% for Astringent Persimmon. Furthermore, portfolio presented that the production ratio was 10% for Chestnut, 9% for Jujube, 3% for Walnut and 78% for Astringent Persimmon in the near future. The cause was analyzed due to maintain stable production and income of Astringent Persimmon and Chestnut. Meanwhile, the revenue of Walnuts and Jujube was in great variation with relatively higher revenues.