• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.6
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• pp.67-75
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• 2011

This study was carried out to investigate the changes in citizen satisfaction with parks and green spaces in Daegu. Three surveys were conducted using the same measurement tools in 1986, 2001, and 2010. Major results are as follows: 1. The overall satisfaction level with parks and green spaces increased remarkably over the last25years. Satisfaction levels with city spaces overall were higher than that of nearby surrounding areas. 2. Diversity of green spaces was the most distinguished indicator in increasing level of satisfaction while the management level of green space facilities showed the lowest improvement. 3. The factor analysis for individual variables for satisfaction resulted in two factors: functions and physical conditions were categorized as one factor, and indicators for the planning of green spaces were the other. Using a regression model, the major variables found for satisfaction were diversity, management level of woods, quantitative level, function of static recreation, and management level of facilities, respectively. 4. Regarding satisfaction level by the type of green spaces, green spaces by streets showed a remarkable increase while green spaces in industrial areas showed the lowest improvement. A factor analysis for each type of green space resulted in 3 factors: green spaces of urban parks, green spaces of urban recreational facilities, and green spaces of each district including residential areas and industrial areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.312-316
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• 2010

현재 국내에서 주로 사용되고 있는 홍수기 다목적 댐의 홍수조절효과에 대한 정량적인 평가지표로는 유량조절률, 저수지 방류율, 저수지 저류율, 저수지 이용률 등이 있다. 이러한 평가지표들은 유입량, 방류량, 저류량 등의 자료를 단순 비교하는 방법을 사용하고 있는데, 홍수조절효과 평가지표 산정식에 사용되는 자료들이 가지는 불확실성이 평가에 고려되지 못하고 있으며, 다목적댐에서 얻을 수 있는 자료만을 사용함으로써 댐 하류 지점에서의 홍수조절효과를 평가하지 못하고 있다. 또한 수자원 시스템의 설계에 있어서 허용 가능한 부분적인 실패를 고려하지 못하는 등의 문제점이 존재하므로, 홍수조절효과를 정량화 할 수 있는 새로운 지표의 개발이 요구된다. 본 연구에서는 각종 변수들이 가지는 불확실성, 댐 하류지점에서의 홍수조절효과, 수자원 시스템에서 허용 가능한 부분적 실패를 고려하기 위하여 홍수조절효과 정량화 지표 개발에 퍼지집합 이론을 적용하였고, 충주댐 유역을 시험 유역으로 선정하여 연구를 수행하였다. 대상 홍수사상으로는 2006년도 7월의 홍수사상을 적용하였으며 그에 따른 인자들을 퍼지화하고 시스템의 상태로부터 허용 가능한 부분적인 실패 영역을 구분하였고, 통합 신뢰도-취약도 지수를 적용하여 홍수조절효과 정량화 지표를 개발하였다. 적용 결과, 본 연구를 통하여 개발된 통합 신뢰도-취약도 지수는 저수지의 홍수조절효과를 보다 구체적이고 객관화하여 나타낼 수 있었다.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.149-159
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• 2017

There are many studies on the health and protection of Old-growth and Giant Trees, concentrating on empirical judgment and basic protection measures. The problem this study addresses is the relative importance and priority of the health evaluation indicators of Old-growth and Giant Trees. Firstly, this study exports the evaluation indicators of Old-growth and Giant Trees. The evaluation system for the degree of danger of Old-growth and Giant Trees are composed of two layers: 5 fields and 46 indicators. Secondly, using the AHP and PCA method can determine the weight of each field and each index factor. The process of AHP establishes the relative importance judgment matrix of each field and fully proves that the main cause of danger is individual aging. The PCA method suggested that trunk rot status, light conditions, tree surgeries, bacterial diseases, and soil moisture level are the most important factors in each field. These aspects should be given priority in the management and protection of Old-growth and Giant Trees. Weight values obtained in this study seemed to be useful in the evaluation of Old-growth and Giant Trees.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.161-166
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• 2001

Purpose: Poor living conditions such as overcrowding and sharing a bed are reported to be significant risk factors for H. pylori infection throughout childhood. We investigated the prevalence of Helicobacter pylori infection in Korean athletes who are obliged to live together in training camps over six months a year. Methods: Blood sampling and surveying through questionnaire were performed on 440 regular high school students (228 boys and 212 girls) and 220 athletes (148 boys and 72 girls) of a physical education high school. We measured serum IgG Ab to H. pylori in order to compare the prevalence of H. pylori infection between normal adolescents and athletes. In addition, we conducted a nutritional analysis and questionnaire survey for socioeconomic status in order to compare other risk factors that might influence H. pylori infection between groups. Results: The prevalence (43.2%) of H. pylori infection in athletes was higher than that (22.7%) in the controls. No significant differences in the nutritional factors or socioeconomic status, such as Hollingshead index, type of house, and crowding index, were found between the groups. Multivariate analysis showed that crowding and the difference in school type were the significant predictors of H. pylori seropositivity after controlling for dietary and socioeconomic factors. Conclusion: Living together in training camps might be a significant risk factor for H. pylori infection in athletes.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.197-205
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• 2008

Total displacement under non-reinforcement is a quantitative index of rock mass behavior during tunnel excavation and depends widely upon geological characteristics. The primary purpose of this study is to suggest a rock mass evaluation method, well representing tunnel behavior during excavation, according to rock type. A 3-D numerical analysis was carried out, with consideration of the shape of tunnel section, excavation condition and so forth, in a sedimentary rock-based tunnel, and total displacements under non-reinforcement according to rock mass class were calculated. Finally, quantification analysis was carried out to assess correlation of the total displacement with RMR parameters. As the result, a modified RMR system fer quantification of rock mass behavior during tunnel excavation is suggested.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.81-98
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• 1999

The influence of tunnelling on buildings has become an important issue in urban areas. The problem is an interactive one: not only do tunnelling settlements affect existing structures, but existing structures affect tunnel-induced soil movements. In order to examine the constraint of surface settlement and the degradation of building damage parameters, 3-dimensional elasto-plastic finite element analyses are peformed. Also, in this paper, the results of the parametric studies for the variations of the damage parameters due to the ground movements are presented by utilizing 2-dimensional elasto-plastic finite element models, totally 162 models. The width of a structure, its bending and axial stiffness, its position relative to the tunnel and the depth of tunnel are considered. The interaction is shown by reference to commonly-used building damage parameters, namely angular distortion, deflection ratio, maximum building settlements, maximum differential settlements and horizontal strain. By introducing relative stiffness parameters which combine the bending and axial stiffness of the structure with its width and stiffness of soil, design curves are established. These give a guide as to the likely modification of the greenfield settlement trough caused by a surface structure. They can be used to give initial estimates of likely building damage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.393-403
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• 2008

While characteristics of topography, soil, and vegetation coverage were surveyed, also surface runoff and soil erosion for each rainfall event were measured to analyze effect of change of land cover conditions in mountain areas, Yangyang, directly after wildfire. Fifteen rainfall events were taken in total during the survey period. The result of this survey appeared that the amount of surface runoff and soil erosion are a great difference between plots with rapidly recovered vegetation and bare plots after wildfire. The burned plots where vegetation recovered rapidly generated two times or more of surface runoff and soil erosion than control plots, as burned plots with bare soil showed about ten times of surface runoff and sediment than control plots. The result of correlation analysis between main parameters of the surface runoff and soil erosion presented that rainfall factors and vegetation factors had significant effects on runoff and soil erosion. The sensitivity of runoff and soil erosion showed specially high correlation with vegetation indices. If the land surface disturbed by wildfire are recovered by natural vegetation as time passes, runoff and soil erosion may be decreased gradually. Because runoff and soil erosion in the areas with rare vegetation or bare soil are generated continuously, the discriminated mediation strategies would be established as condition of each region.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.68-73
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• 2009

본 연구는 SWSI를 보완한 식을 이용하여 금강유역에 대해 농업가뭄지수(ASWSI)를 산정하고 농업가뭄 분포도를 작성하여 가뭄지수에 의한 농업용 저수지 유역의 가뭄을 평가하는 방법을 제시하였다. SWSI는 유역 단위의 수문학적 가뭄을 평가하기 위하여 개발된 지표로서 융설량, 강수량, 하천유출량, 저수지 저류량이 입력인자로서 유역별, 계절별로 입력인자를 선택적으로 적용하여 유역의 수문학적 가뭄을 평가한다. 본 연구에서는 가뭄에 영향을 미치는 인자를 강수량, 저수지 유입량 및 저수량으로 결정하고 ASWSI의 입력인자를 저수지 상류유역은 강수량과 유입량, 하류지역은 강수량과 저수량을 사용하였다. 금강유역 내 천만톤 이상의 대표 저수지 7개를 선정하여 16개년(1991-2006) 동안의 저수지 상 하류 유역의 농업가뭄지수를 산정하였으며, 산정된 결과를 토대로 다중회귀분석을 실시하여 금강유역 용수구역별 농업가뭄지수 분포도를 작성하였다. 적용결과를 과거 가뭄사상에 검증한 결과, 1994년 1, 2차 가뭄 피해기간인 7월과 9월에 대해서 심한가뭄 상태로 표현하였고, 1995년 가장 가뭄이 심화되었던 6월의 가뭄에 대해서도 심한가뭄으로 표현하였으며, 2001년에도 5월의 최대 용수부족 상황에 대해서 심한가뭄을 표현하였다. 이처럼 ASWSI가 실제 가뭄 발생 현상과 일치함을 확인하였으며, 농업가뭄을 표현하는데 있어 적합한 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.95-95
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• 2016

한반도 중부지방은 2014년과 2015년에 연이은 강수량 부족으로 많은 지역에서 가뭄 현상이 나타났다. 특히, 한반도는 여름철에 강수가 집중되는 몬순기후대에 속하기 때문에 여름철 강수량은 생활용수나 농업용수 확보 등 이수 측면에서 매우 중요하다 할 수 있다. 이러한, 한반도(남한)의 중부지역 가뭄을 유발하는 강수량의 부족 현상은 대략 5-10년(평균 7-8년) 주기로 반복된다. 그리고 이러한 10여년 주기 변동성과 더불어 예외적인 경우가 발생하고 매번 그 심도도 변화한다. 이러한 주기성을 우연이라 보기는 어려울 것이나 예외적인 경우나 심도를 가늠할 수 없다는 점(인과관계가 불분명하다는 점)에서 확정론적 현상이라 단정하기도 어려운 현실이다. 따라서 본 연구에서는 이러한 주기적 가뭄을 야기하는 강수량 변동의 원인을 지구물리학적 측면에서 추론해 보고자 한다. 가뭄은 인위적인 조건에 의해서도 발생하고 인과관계에 따른 정의도 다양하지만, 본 연구에서는 자연 상태에서 강수량의 부족에 의한 가뭄 조건만을 고려하였다. 강수과정은 지구의 물순환 운동에 의해 야기되고 지구의 물순환 운동은 지구의 역학적 운동 및 상호작용 관계에 의해 발생한다고 알려져 있다. 따라서 본 연구에서는, 지구물리 과정의 일부로 강수과정을 유발하는 지표인자로 SST와 같은 기후 인자에 대해 변동 주기의 상관성을 범지구적인 시공간 규모에서 검토하였다.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.403-411
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• 2014

This study Development of Evaluation Items and Indicators for Hydrological Safety on Agricultural Reservoir improvement and grasped the relative importance through stratification of the evaluation points through AHP technique exercised by group of experts. Below conclusion was acquired based on the study done. Firstly, the hierarchy of the evaluation items was divided into two layers: there were six upper evaluation items and eleven lower evaluation items. Secondly, using the analytic hierarchy process, the importance values of the six upper evaluation items were determined via the paired comparison questionnaire survey and consistency check, which were in the order of maintenance condition (condition evaluation grade), freeboard of levee body (non-overtopping), discharge capacity of spillway, potential flood damage, flood calculation factor and freeboard of downstream bank. The maintenance condition(condition evaluation grade) was significantly influenced the results of the hydrological safety on agricultural reservoir evaluation results. Finally, the study indicated that in the short term, improving the safety check condition evaluation grade will be useful to improve the hydrological safety of the agricultural reservoir because it can be performed immediately.