• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.11-20
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• 2023

The cost of medical treatment for motor vehicle accidents is increasing every year. In this study, we created a model to predict long-term hospitalization(more than 18 days) among minor patients, which is the main item of increasing traffic accident medical expenses, using five algorithms such as decision tree, and analyzed the factors affecting long-term hospitalization. As a result, the accuracy of the prediction models ranged from 91.377 to 91.451, and there was no significant difference between each model, but the random forest and XGBoost models had the highest accuracy of 91.451. There were significant differences between models in the importance of explanatory variables, such as hospital location, name of disease, and type of hospital, between the long-stay and non-long-stay groups. Model validation was tested by comparing the average accuracy of each model cross-validated(10 times) on the training data with the accuracy of the validation data. To test of the explanatory variables, the chi-square test was used for categorical variables.

• Journal of the Korean Society of School Health
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• v.5 no.1
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• pp.84-91
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• 1992

The purpose of this study was to find family characteristics, habit of dietary intake, physical exercise, and mothers' concern related to obesity through questionaires among 5th grade children of 5 emementary schools in Taegu city from May 29th to June 8th, 1989. The data used in this study were collected from 245 obese children and 327 normal children by Body Mass Index with their body weight and height, and measurement of Triceps Skinfold Thickness The findings were as follows: 1. This survey revealed that Triceps Skinfold Thickness was 11.0mm in the obese group and 7.5mm in normal group. Their parents body weight and BMI of the obese group were higher than those of the normal group. 2. Ending of weaning of the obese group had a faster tendency than that of the normal group. 3. It showed that the children of obese group had a hearty appetite during the evening meal and children of the normal group did so in lunch time. 4. The normal group was willing to take exercise but the obese group was not so. 5. Mothers of the obese group showed deeper concern at quantity of dietary intake and physical exercise than mothers of the normal group for their children's health.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.111-125
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• 2012

This study investigates the behavioral characteristic difference of the container volumes of three ports-Gwangyang, Incheon, and Pyeongtaek-Dangjin. All series span the period January 2003 to December 2011. I first test whether the series are stationary or not. I can reject the null hypothesis of a unit root in each of the level variables and of a unit root for the residuals from the cointegration at the 5 percent significance level. I hitherto make use of error-correction model and find that Gwangyang port is the slowest in adjusting the short-run disequilibrium, whereas the adjustment speed of Incheon is much faster than that of Gwangyang. The impulse response functions indicate that container volumes increase only a little to the negative shocks in exchange rate, while they respond positively to the shocks in the business activity in a great magnitude and decay very slowly to its pre-shock level. meaning that the shocks last very long. The accumulative response to the exchange rate increase of 20 won per dollar and the 5 point industrial production increase is the smallest in Gwangyang, no more than a half of that of two ports. The intervention-ARIMA models also forecast that Gwangyang port will have much lower growth rate than Incheon and Pyeongtaek-Dangjin port in trading volumes.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.333-352
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• 2010

This study analyzed the services of libraries for babies and toddlers and the possibilities of service expansion through Bookstart program as a cooperative system for libraries. This study shows how users change their way of using libraries and their perceptions of the services of libraries for toddlers by implementing the questionnaire method and the analysis of library statistics. Results show that most of library users (98.8%) expressed the need for Bookstart program. Respondes also said that libraries, rather than other institutions, should be the place where the program is to be implemented. By analyzing the perceptions of library users, we also find that they think that the age of the first use of a library is more appropriate for toddlers than kindergarten-ages. We also found that library users who participated in a Bookstart program had a positive change in the way they used libraries. After participating in Bookstart programs, many changes occurred with respect to the perception of babies, reading habits of parents, and users' perception of libraries. After introducing Bookstart program, one city library's membership enrollment rates of babies and toddlers increased from 7.1% to 26.2%. But the rate for another city that did not participate in the program was shown at 4.3%. This study suggests that the introduction of Bookstart program would bring changes and expansions to the functions of libraries and the sometimes inflexible attitudes of library users. The study examined Bookstart program as a cooperative system for libraries by changing the perception of library users and activating the services of libraries for babies and toddlers.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.52-63
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• 2014

This is the study on users' perception gap about the effects of leisure space development of the Han River Citizen Park according to leisure constraints and was to identify leisure constraints expressed when using Han River Citizen Park and identify perception on positive and negative impacts according to use behavior characteristics of Han River Citizen Park and leisure space development. In order to compare and analyze the perception gap about the leisure space development of Han River Citizen Park users according to leisure constraints, we classified information and resources, economic affordability, free time on leisure activities in Han River Citizen Park into high influence group and low influence group and did an in-depth analysis. The results are as follows. First, Han River Citizen Park has the nature of neighborhood use with little influence on leisure constraints such as jogging and marathon, biking etc. including walking and relaxation and was a place to visit for simple exercises. Second, in the effects according to leisure space development of Han River Citizen Park, affordable leisure activity costs and ease of access were evaluated the most highly and congestion due to increasing users, increase in administrative operating budget and management personnel were concerned the most. Third, the leisure constraints in Han River Citizen Park were affected in the order of free time, economic affordability, information and resources. There were also perception gaps in congestion due to an increase in administrative operating budget and management personnel, increase in users including improvement of various leisure opportunities and leisure levels, encouragement of pride and attachment for Han river, affordable leisure activity costs depending on the degree of the influence of leisure constraints. Therefore, this study can be said to have the meaning in that we could identify leisure constraints affecting Han River Citizen Park users and resulting perception in leisure space development and revealed that the degree of the influence of leisure constraints varies in the use behavior of leisure space development of Han River Citizen Park and perception of positive and negative development impact. In addition, in order to resolve leisure complaints according to leisure constraints, we studied the need of accompaniment of leisure space operation and management system, development of various customized programs, introduction of recreational space and facilities prioritizing public interest rather than private interest with public relations and information delivery about leisure space of Han River Citizen Park.

• The Korean Journal of Financial Studies
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• v.6 no.1
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• pp.23-45
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• 2000

기존연구에 의하면 무상증자의 공시는 공시기간 중 정(+)의 가격효과를 초래하는 것으로 나타나고 있다. 무상증자에 대한 이러한 시장의 호의적인 반응을 설명하기 위해 여러 가설이 제기되어 왔으며, 그 중 무상증자는 좋은 내부정보를 외부에 신빙성 있게 전달하는 신호기제가 될 수 있다는 신호가설이 특히 지지를 받고 있다. 그런데 짧은 공시기간 중의 정(+)의 주가반응만을 보고 신호가설이 지지된다고 단정짓는데는 무리가 있다. 본 연구에서는 과연 신호가설이 주장하는 것처럼 무상증자가 사업기회의 확대, 미래현금흐름의 증대, 추후 차입여력의 증대를 가져오는가를 더 면밀히 검증하기 위하여 무상증자 실시기업의 장기성과를 조사하였다. 본 연구의 특징은 (1)공시기간 이후의 1년 이내의 기간에 중점을 둔 대부분의 기존연구와 달리 증자 후 36개월간의 장기성과를 측정하였으며, (2)주가수익률 자료와 회계자료를 동시에 이용하여 장기성과를 조사하였고, (3)장기 초과수익률 측정과 검증에 있어 통계적 오류가 있는 누적초과수익률(CAR)을 보완하기 위해 매입보유초과수익률(BHAR)을 사용했으며, 이를 위해 엄격한 기준을 적용하여 표본기업과 비교기업을 선정하였다는 데 있다. 실증분석 결과 신호가설을 지지하는 증거는 발견하지 못하였으며 오히려 무상증자 실시기업이 시장평균 또는 비교기업인 비증자기업에 비해 장기적으로 주가수익률 및 영업성과에 있어 저성과를 보이는 증거를 상당 수 발견하였다. 구체적으로 동일가중평균수익률로 조정한 보유기간 초과수익률의 경우 증자 후 1개월에서 24개윌까지의 BHAR이 5% 미만 수준에서 부(-)의 값을 보였으며, 비모수통계치를 사용할 경우 $1{\sim}36$개월까지의 전기간에서 유의한 부(-)의 저성과를 보이고 있다. 또한 영업성과면에서도 증자기업이 비증자기업에 비해 증자 후 수익성과 현금흐름이 저조하게 나타나고 있다.해 현물시장의 수익률, 변동성이 높은 것으로 나타났으나, 변경후에는 현물시장에 비해 선물시장의 수익률 변동성이 높은 것으로 나타났다. VAR 분석에 의하면 변경후가 변경전에 비하여 선물이 현물을 선도하는 시차가 다소 커진 것으로 나타나 현물시장과 선물시장이 동시에 가격제한폭 확대후에 비효율적으로 되었다는 의미로 판단된다.기간에서는 선물의 15분 선도효과와 현물의 1분 선도효과가 발견되어 선물의 선도효과가 지배적임을 발견하였다.적 일정하게 하는 소비행동을 목표로 삼고 소비와 투자에 대한 의사결정을 내리고 있음이 실증분석을 통하여 밝혀졌다. 투자자들은 무위험 자산과 위험성 자산을 동시에 고려하여 포트폴리오를 구성하는 투자활동을 행동에 옮기고 있다.서, Loser포트폴리오를 매수보유하는 반전거래전략이 Winner포트폴리오를 매수보유하는 계속거래전략보다 적합한 전략임을 알 수 있었다. 다섯째, Loser포트폴리오와 Winner포트폴리오를 각각 투자대상종목으로써 매수보유한 반전거래전략과 계속거래 전략에 대한 유용성을 비교검증한 Loser포트폴리오와 Winner포트폴리오 각각의 1개월 평균초과수익률에 의하면, 반전거래전략의 Loser포트폴리오가 계속거래전략의 Winner포트폴리오보다 약 5배정도의 높은 1개월 평균초과수익률을 실현하였고, 반전거래전략의 유용성을 충분히 발휘하기 위하여 장단기의 투자기간을 설정할 경우에 6개월에서 36개월로 이동함에 따라 6개월부터 24개월까지는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1747-1754
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• 2013

We evaluate the impact of near work has on myopia and how they differ across generation. The study subjects were 201(83 males and 118 females) adults who live in Cheongju and Daejeon. Myopia was defined as more than or equal to (-)2.50D. The subjects were divided myopic and control group. The surveys and eye tests that are related to near work and refractive error were conducted and the relationship between the degree of myopia and near work was investigated. Then, the groups were divided into people in their 20s and 30s and the comparisons were made again. The survey results showed significant differences between myopic and control groups that depended on: hours spent in school and outdoor activities during high school period, degree of refractive error caused by level of exercises during the junior high school and high school years, refractive error based on the type of high schools, also hours spent in school and outdoor activities. When the same question was done on the group in their 20s and 30s, there was a different outcome in trends between the groups and refractive error depending on whether they exercised. The degree of near work is one of the environmental risk factors that affect myopia and must be considered when studying myopic progression. However, when discussing specific behavioral patterns in relations to myopia prevention, culture and visual environment of a given generation must also be considered.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1362-1366
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• 2006

우리나라에서는 하천법 제11조에 의거하여 10년마다 한 번씩 수자원장기종합계획을 수립하고 있으며, 필요에 따라 5년마다 이를 수정 보완하고 있다. 2001년 7월 수자원장기종합계획(Water Vision 2020)이 수립된 이후 잦은 봄 가뭄 등 이수측면에서의 사회, 경제, 환경의 변화와 최근 이상홍수 등으로 인한 대규모 홍수피해 발생에 따른 치수측면의 종합적인 대책의 제시가 요구되면서 2001년 수립된 계획에 대한 보완 필요성이 제기되었다. 또한 수자원계획의 신뢰성에 대한 시민단체 등의 문제제기와 지역 차원의 수자원계획 및 수자원환경에 대한 국민적 관심 증대로 인해 계획 수립 과정과 결과에 대한 국민적인 공감대 형성을 위한 체제의 구축이 금번 보완 계획의 수립을 통해 추진되고 있다. 금번 수자원장기종합계획 보완은 투명성 확보라는 큰 목표를 가지고 수행되고 있으며, 이를 통해 국가 수자원 관리의 청사진을 제시하고 물 수급 전망 및 용수수급 계획을 수립하는 과정에 있다. 기 개발된 한국형 통합수자원평가계획 모형인 K-WEAP 모형을 보완 계획 수립 과정에서 활용하고 있으며, K-WEAP 모형을 통해 물 수지 분석을 수행하여 수급 균형을 판단함으로써 일반 대중에게 물 수급 관련 상황에 대한 이해력을 높일 수 있다는 장점을 확보할 수 있다. 본 연구에서는 K-WEAP 모형을 이용하여 각 권역별로 2003년의 물 수급 현황을 분석하여 이를 하천의 관측유량과 비교해봄으로써 모형의 검증을 수행하였으며, 각 권역에서 시나리오별로 추정된 용수수요량을 이용하여 물 수지 분석을 수행함으로써 목표연도별 물 수급 분석결과를 제시하였다. 물 수급 분석 시 지하수 및 농업용 저수지 등 하천과 다목적댐 이외의 지역 공급원에 대해서도 고려하였으며, 이를 통해 수자원계획 수립 시 도움이 될 수 있는 기초적인 자료를 제공할 수 있었다. 인공순환에 의한 저감효과가 크지는 않을 것으로 예측된다. 조사 기간중 H호의 현존 식물플랑크톤량의 $60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.49-59
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• 2001

In the transportation planning process, origin and destination(O-D) trip matrix is one of the most important elements. There have been developments and applications of the methodology to adjust old matrices using link traffic counts. Commonly, the accuracy of an adjusted O-D matrix depends very much on the reliability of the input data such as the numbers and locations of traffic counting points in the road network. In the real application of the methodology, decisions on the numbers and locations of traffic counting points are one of the difficult problems, because usually as networks become bigger, the numbers of traffic counting points are required more. Therefore, this paper investigates these issues as an experiment using a nationwide network in Korea. We have compared and contrasted the set of link flows assigned by the old and the adjusted O-D matrices with the set of observed link flows. It has been analyzed by increasing the number of the traffic counting points on the experimental road network. As a result of these analyses, we can see an optimal set of the number of counting links through statistical analysis, which are approximately ten percentages of the total link numbers. In addition, the results show that the discrepancies between the old and the adjusted matrices in terms of the trip length frequency distributions and the assigned and the counted link flows are minimized using the optimal set of the counted links.

• Journal of the Korean association of regional geographers
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• v.16 no.2
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• pp.100-109
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• 2010

The study examines two different sites to analyze the difference of stream channel profile between two different landuse areas on Neponset River, Boston, MA. Landuse represents the current status of land in terms of human, agricultural or forest, industry and environmental activity types. According to the previous research, forest and urban area are significantly distinguished in chemical characteristic, shape and bed load of the stream. On the chosen sites, I look at the cross-section profile, the slope, velocity, and roughness of the channels. With the data collected at the site I determined the value for the channel bed material using Manning's equation, and compared with the result of HEC-RAS model with the cross-section profile data I measured. In the forest area, water surface elevation and bed material obtained through Manning's equation are very close to HEC-RAS model result. However, in the resident area the Manning's 'n' value calculated much higher than assumption which was considered as cobble whose 'n' value is 0.03-0.06. The difference could be caused by unusual steep elevation on the site and the dam present down further. With the steep elevation upside of dam, there is critical-depth condition occurs. The difference of Manning's 'n' value reflects the difference of depth. HEC-RAS model was run to analyze the difference and the result shows that depth is 0.36 much less than 0.688 what I computed when the Manning's n value is 0.03(cobble) instead of the result of the study (0.13292). Beside, dam is a major source of fragmentation and degradation of stream, and it's possibly inferred upstream water levels are increased and stream velocity is decreased. This study is meaningful for introduction of HEC-RAS in geography field to analyze different sites with channel bed material, and it is going to be used more actively to manage river and river side.