• Proceedings of the Korean Reliability Society Conference
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• 2011.06a
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• pp.131-140
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• 2011

도로안전시설용 시선유도봉은 통상 도로에 설치되어 운전자의 시선을 유도하고 차선을 분리하는 용도로 사용된다. 이러한 시선유도봉은 주로 도로상에 설치되기 때문에 차량과 부딪히는 경우가 자주 발생하므로 제품의 내구성이 특히 요구된다. 종래의 시선유도봉에 대한 평가방법은 제품의 일부를 채취하여 재료의 기본 품질 성능만을 평가하였다. 그러나 현장의 도로관리를 담당하고 있는 수요기관에서는 빈번한 사고와 민원으로 인해 제품의 평가방법에 대한 문제 제기를 하였고, 완제품 상태로 신뢰성을 평가할 수 있는 방법 개발을 요구하였다. 따라서 본 연구에서는 시선유도봉의 주요 고장 요인이 되는 차량 충돌에 의한 재질 파손, 바퀴 압축에 의한 회복 불능, 제품 표면에 부착되는 반사시트의 박리 및 변색에 대한 고장 메커니즘 분석하고, 이러한 고장을 재현할 수 있는 신뢰성 평가법을 개발하고자 하였다. 주요 고장 메커니즘 분석을 위해 국내.외 평가 기준을 조사하였으며, 특히 미국 AASHTO's (American Association of State Highway and Transportaion Officials)의 NTPEP (National Transportation Products Evaluation Program)에서 수행하고 있는 내구성 평가 방법에 대한 사례 조사를 통해 국내 적용을 검토해 보았다. 또한 서울시설관리공단의 협조로 가장 주요한 고장의 요인으로 꼽히는 차량 충돌 시험을 올림픽대로 내 조각공원에서 실시하였다. 그 결과 시험실에서 고장을 재현할 수 있는 신뢰성 평가 장비 개발의 필요성이 부각되었으며, 차량 충돌과 바퀴 압축을 모사할 수 있는 신뢰성 평가 장비를 제작하였다. 시선유도봉의 신뢰성 평가는 기본적인 품질성능평가 이외에 신규로 개발된 충격시험(고온, 저온, 반사지)과 굴곡압축시험, 반사지와 재질의 내후성 시험을 실시하였다. 또한 국내 9개사(社) 10개 제품에 대한 신뢰성 비교평가를 실시한 결과, 제품의 내구성에 중요 척도가 되는 신뢰성 평가 기준을 설정할 수 있었고, 합리적인 제품의 가격 수준과 품질 수준에 대한 신뢰성 가이드를 제공할 수 있었다.

• Journal of environmental and Sanitary engineering
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• v.21 no.2 s.60
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• pp.20-29
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• 2006

Analysis of benthic macroinvertebrate community and biological estimation of water quality by the benthic macroinvertebrates were conducted at Olympic Park at its nearby waters in Seoul from December, 2004 to September, 2005. The benthic macrovertebrates were 49 species. Among them, 39 species of aquatic insects were included 11 species in odonata, 9 species in diptera, 7 species in hemiptera, 6 species in coleoptera, 3 species in ephemeroptera, 2 species in trichoptera and 1 species in lepipdoptera, and 10 species of non-insects were 6 species in mollusca, 2 species in hirudinea and 2 species in oligochaeta. Species number of lakes, Seongnae Stream within and outside the Olympic Park was 25 species, 35 species and 33 species, respectively. Individual number of lakes, Seongnae Stream within and outside the Olympic Park was $131\;inds/2.5m^2\;239\;inds/2.5m^2\;556\;inds/2.5m^2$, respectively. Mean dominance indices of lakes, Seongnae Stream within and outside the Olympic Park was 0.74, 0.61 and 0.72, respectively. According to the saprobic system based on the ESB index(Ecological score of benthic macroinvertebrate community), all survey sites are $\beta-mesosaprobic$ waters. To increase of abundance of benthic macroinvertebrates, regular interval monitoring has to be enforced and standard of water quality for the ecological ponds of Olympic Park has to be prepared.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.491-499
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• 2020

Increasing impervious surfaces can cause various physical and mental illnesses as well as further problems like deterioration of the thermal environment and disconnection of the water circulation system in the downtown area. This study is intended to suggest baseline data for the future creation or remodelation of large-scaled urban parks in consideration of human health on the aspect of climate by analyzing air ions condition and correlation analysis between air ions and meteorological elements depending on distances from the center in the urban park. The study site was divided into four types by distances from the center of Olympic Park in Songpa-gu, Seoul, then classified as A and B. After selecting 80 points to record, land coverage and vegetation status were investigated, and then meteorological elements and air ions were measured. First, the green space rate by section is A section Center (90%)> Inner (70%)> Outer-inner (10%) = Outer (10%), B section Center (100%)> Inner (60%)> Outer- In order of inner (30%)> Outer (0%). Second, for weather factors, the temperature was analyzed by Outer (24.18℃) > Outer-inner (22.90℃) > Inner (22.43℃) > Center (21.719℃). For relative humidity, center (46.49%) > Inner (43.36%) > Outer-inner (42.41%) > Outer (38.53%) was analyzed. Third, In the case of cations in the air ions, Outer(435.71ea/㎤) > Outer-inner(415.16ea/㎤) > Inner (389.46ea/㎤) > Center (352.64ea/㎤). In the case of negative ions, Center (569.72ea/㎤) > Inner (499.83ea/㎤) > Outer-inner(410.58ea/㎤) > Outer (292.02ea/㎤). It was analyzed to increase toward Center, and analyzed to decrease with increasing distance from road. For the Air ion index, it was analyzed as Center (1.67) > Inner (1.31) > Outer-inner (1.08) > Outer (0.71). Negative irons was analyzed to increase when its measuring points close to the center and decrease with shortening distance to the road. Fourth, as a result of correlation analysis, positive(+) correlation is negative ions and ion index. These were measured to increase as the recording points closing to the center of the park from the road. The negative(-) correlation is temperature, solar radiation, and positive ions. These increased as getting closer to the road.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.4
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• pp.36-47
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• 2008

The purpose of this study is to classify and assess the characteristics of urban Korean parks by on-site park users' reactions, such as satisfaction, preference and cognitive image of the park and park facilities. The park facilities are classified into five types of satisfaction: management status, activity facilities, convenient facilities, circulation and density, and landscape facilities. The park users are satisfied with conversation, rest and relaxation in the parks, but not satisfied with studying and nature experience. The behaviors in the park are classified as park activities, emotional and experiential activities, and nature activities. The results indicate that the images of the parks are stable, comfortable and natural. There are three factors to classifying the park images: nature-harmony, openness, uniqueness. Preferences for each parks are generally good. According to the criteria such as satisfaction of park facility, behavioral satisfaction, images and preference for each park, the 12 parks are divided into 5 different types: multi-purpose park, well-balanced park with natural elements, urban open space, park to be improved, and ecological park. The characteristics of each park was analyzed and categorized. This study dealt with only the parks in Seoul and its environs, and the survey was only done during the summer season. Therefore, further research is necessary to enlarge and generalize the results of this study, considering seasonal and regional variations.

• Archives of design research
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• v.19 no.4 s.66
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• pp.31-40
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• 2006

For a long time, we have been good at the static image, 'the country of calm morning' as reminding Korea. But, it became a chance that we were recognized newly and actively through the success of the Olympic games in 1988 and World cup games in 2002 all over the world. And foreigners' interest and expectation for Korea becomes much higher by these reasons. Moreover, the importance of our cultural industry, recognition for new cultural improvement have been changing step by step by the oriental trend in Asia in these days. So, this study intends to realize the Korean symbol with showing Korean Identity and its image's applying to the street furniture design through the making of special street which expresses well the Korean Image. There is a purpose of this study not to use as just street furniture but to make characterized Korean culture through showing examples which are based on Korean culture. The way of the improvement for the street furniture design using Korean image are these we analyze the character of Korean international image with the previous data for the change of Korean Image. We understand the symbol of changed Korean international Image, and extract the design elements. We analogize the shape, material and color image of the street furniture which is joined with both the Korean national image and formative traditional elements. At last, we formalize its symbolic image by applying to the street furniture according to the design improvement process with the analogized image. The formal study using Korean image makes more cleary the Korean Identity, and it doesn't influence only the actual change but also Korean cultural value equipment.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.441-453
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• 2015

In this paper, according to the illuminance at night with artificial lighting in downtown Seoul, trees flowering and leaf growth rate was performed as a case study to examine whether there is a difference. The illuminance was measured at 78 points on a total of 26 points, the range of illuminance were divided into three groups considering land use, Group A (plots 1-7) were 4.90 ~ 112.50 lx, Group B (plots 8 to 18) were 0.45 ~ 42.40 lx, group C (plots 19 to 26) were 0.28 ~ 22.10 lx. According to the One-way ANOVA on illuminance difference, the survey groups were classified into three groups. To survey the ratio of the flowering Prunus yedoensis and Rhododendron spp. and to survey the ratio of leaf growth Zelkova serrata, Ginkgo biloba, and Acer palmatum each 30 individuals were investigated. Rhododendron spp. to study the ratio of the flowering and Acer palmatum to study the ratio of leaf growth were determined to be useful as indicator woody species according to the correlation. The higher illuminance of night lighting is, the faster flowering and leaf growth of trees will be by correlation between the mean illuminance of each group and the flowering and leaf growth of trees. In the future, should be made a more detailed study of how much affect to the trees with some impact on the level of light pollution at night lighting.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.256-267
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• 2015

The intelligent transportation systems allow us to have valuable opportunities for collecting wide-area coverage traffic data. The significant efforts have been made in many countries to provide the reliable traffic conditions information such as travel time. This study analyzes the impacts of the fog weather conditions on the traffic stream. Also, a strategy for predicting the long-term traffic speeds is developed under foggy weather conditions. The results show that the average of speed reductions are 2.92kph and 5.36kph under the slight and heavy fog respectively. The best prediction performance is achieved when the previous 45 pattern cases data is used, and the 14.11% of mean absolute percentage error(MAPE) is obtained. The outcomes of this study support the development of more reliable traffic information for providing advanced traffic information service.

• Journal of Preventive Medicine and Public Health
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• v.22 no.1 s.25
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• pp.136-145
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• 1989

This study made a descriptive analysis of the cumulative amount and rate of sports medical care utilization during the 24th Seoul Olympic Games by the participating athletes, officials, etc. The sports medical care utilization was a component of the total medical care use and was basically caused by the prevention and treatment of sports injuries. The analytic data were derived from the Olympic Health Management Information System(OHMIS) of the SLOOC and the Korea Athlete Trainer Association(KATA). These were analyzed according to the quantity of physician visits and the utilization rate, which was the amount of utilization divided by the total number of participating persons. The results were as follows: Firstly, the sports medical care utilization by the persons participating in the Seoul Olympics amounted to 17.9% of the total medical care utilization. The venue medical services utilization accounted for 54.7% of the total physician visits, which was larger than the village medical center's utilization. The number of physician visits per hundred persons during the 2 week period in the venue clinic was 3.03 and that of the village medical center was 2.51, therefore, the total was 5.54. Secondly, athletes accounted for 82.3% and officials 12.2% in the sports medical care utilization by participants. These results were because athletes, who were directly related to the games, called extremely often on the physicians. The utilization rate of sports medical care by athletes was 34.29. Thirdly, the sports medical demand according to type of therapy could be ranked from high to low in the following order: sports massage, thermal therapy, and electrical stimulation treatment, etc. The department of physical therapy in the village medical center was used a great deal. Fourthly, the trend of daily sports medical care utilization by the athletes showed a bell shape centering around the opening day of the Seoul Olympic Games. The utilization rate of athletes was 2.3; however, that of officials was 0.6. Lastly, the sports medical demand was calculated according to the continents, and Central America, Africa and Middle-East Asia proved to have a higher rate of sports medical care utilization than the more powerful and industrialized continent or regions.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.265-274
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• 1998

본 논문은 도로를 주행하는 차량의 지점속도에 대하여 단기간(short-term)으로 예측하는 네 가지의 모형들에 대한 개발 및 결과의 비교하고 평가했다. 사용된 기법들로는 다중회귀분석, 시계열분석(ARIMA), 인공 신경망, 칼만필터링 등이며, 모형의 구출을 위하여 다수의 독립변수 및 입력변수가 요구되는 다중회귀분석과 인공 신경망에서는 연속방정식에서 고려되는 변수들간의 단순상관계수 및 편상관계수의 계산을 통해서 입력변수가 설정이 되었으며, 시계열분석(ARIMA)과 칼만필터링 등 단일 입력 변수만을 요하는 모형에서는 바로 전 시간대와 현재시간대의간격동안 속도의 변화량을 입력변수로 설정하였다. 속도를 비롯해서 교통 데이터는 현장자료를 사용하였는데, 이는 서울의 한강 옆에 위치한 올림픽대로 중 한강대로에 위치한 검지기 3개를 통해서 천호동 방면으로 이동하는 교통류에 대해서 17시간 (00시~17시)동안 수집했다. 17시간 수집했는데 그중에 검지된 속도는 14km/h에서 98km/h까지 변하는 등, 수집된 자료에는 다양한 교통상태가 포함되어 있는데 이는 각 모형들의 정확한 예측력과 적응성을 평가하기 위함이었다. 각 모형은 예측하고자 하는 시점으로부터 1, 5, 10, 15분 후의 속도를 예측하는 것으로 총 4가지의 예측시간간격으로 각각 실험되었다. 결과는 전반적으로 신뢰성 있게 나왔으나 그중에서도 정확성면에서는 인공신경망과 칼만필터링이 우수했고 적응성면에서는 칼만필터리딩 탁월했다. 또한 1분 후의 속도를 예측하는 결과들은 모형들간에 거의 비슷한 정확도를 보여주었는데 이는 입력변수의 설정이 중요한 것임을 보여주는 것이라 판단된다. 있는 기법이다.적으로 세부적 차종분류로 접근한다.의 영향들을 고려함으로써 가로망 설계 과정에서 가로망의 상반된 역할인 이동성과 접근성의 비교가 가능한 보다 현실적인 가로망 설계 모형을 구축하고자 한다. 지금까지 소개된 가로망 설계모형들은 용량변화에 대한 설계변수의 형태에 따라 이산적 가로망 설계 모형과 연속적 가로망 설계모형으로 나뉘어지게 된다. 본 논문의 경우, 계산속도의 향상 측면에서는 연속적 가로망 설계 모형을 도입할 수 있지만, 이때 요구되는 도로용량이 이산적인 변수(차선 수)로 결정되어야만 신호제어 변수를 결정할 수 있기 때문에, 이산적 가로망 설계 모형이 사용된다. 하지만, 이산적 설계모형의 경우 조합최적화 문제이므로 정확한 최적해를 구하기 위해서는 상당한 시간이 소요되며, 경우에 따라서는 국부 최적해에 빠지게 된다. 이러한 문제를 극복하기 위해, 우선 이상적 모형의 근사화, 혹은 조합최적화문제를 위해 개발된 Simulated Annealing기법의 적용, 연속적 모형의 변수를 이산화하는 방법 등 다양한 모형들을 고려해 본 뒤, 적절한 모형을 적용할 것이다. 가로망 설계 모형에서 신호제어를 고려하기 위해서는 주어진 가로망에 대한 통행 배정과정에서 고려되는 통행시간을 링크통행시간과 교차로 지체시간을 동시에 고려해야 하는데, 이러한 문제의 해결을 위해서 최근 활발히 논의되고 있는 교차로에서의 신호제어에 대응하는 통행배정 모형을 도입하여 고려하고자 한다. 이를 위해서 지금까지 연구되어온 Global Solution Approach와 Iterative Approach를 비교, 검토한 뒤 모형에 보다 알맞은 방법을 선택한다. 차량의

• Journal of Korean Society of Transportation
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• v.34 no.2
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• pp.158-167
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• 2016

This study evaluates potential sources of errors in k-NN(k-nearest neighbor) algorithm such as procedures, variables, and input data. Previous research has been thoroughly reviewed for understanding fundamentals of k-NN algorithm that has been widely used for short-term traffic states prediction. The framework of this algorithm commonly includes historical data smoothing, pattern database, similarity measure, k-value, and prediction horizon. The outcomes of this study suggests that: i) historical data smoothing is recommended to reduce random noise of measured traffic data; ii) the historical database should contain traffic state information on both normal and event conditions; and iii) trial and error method can improve the prediction accuracy by better searching for the optimum input time series and k-value. The study results also demonstrates that predicted error increases with the duration of prediction horizon and rapidly changing traffic states.