• 농업과학연구
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• 제47권4호
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• pp.1159-1168
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• 2020

The conduits of agricultural reservoirs undergo deterioration over a considerable period of time and this is highly likely to cause structural problems such as cracks. It is therefore important to consider the effects of structural defects on the body from the viewpoint of stability and maintenance of the embankment. In this study, basic data on the effects of the crack location on the stability of the embankment is obtained by identifying, comparing, and analyzing the erosion characteristics and pore water pressure behavior through a large-scale model experiment that involves classifying the location of the conduit cracks. From the results of the experiment, it was confirmed that when a crack occurred, the amount of leakage increased as the location of the crack portion was closer to the water level, and the internal erosion phenomenon accelerated, thereby increasing the possibility of piping. It was also found that an upstream conduit crack affects the erosion and water pressure change of the central and downstream conduit of the embankment, and the conduit crack has a very large effect on the pore water pressure despite the low upstream water level. Therefore, the seepage behavior of the embankment for each conduit crack identified in this study is considered to be useful basic data for preparing a repair and reinforcement plan according to the crack location in the future.

• 대한예방한의학회지
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• 제8권2호
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• pp.55-63
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• 2004

Objectives : This study was designed to identify the possibility of aroma oils as the complementary medical goods specially for the effects of aromatheraphy on xerosis cutis. Materials and Methods : The participants were 23 adult patients and all participants of this study use aroma oils which is known to effect on xerosis cutis. The subjects consist of voluntary patients with xerosis cutis in Seong-So Hospital in Andong Kyoungbuk, Korea. From April 1st to April 30th, 2004 for 4 weeks, the subjects massaged aroma oils on itching parts or the whole body. Aroma oils were Lavender, Losemary, Jasmine and blended drop by drop per 10ml jojoba oil which used a carrier oil. Skin pH was measured with a skin pH meter(Model : HI98110, Se-Chang instruments, made in Portuga. After 4weeks using aroma oils, the participants answered questions about the feeling of satisfaction with aroma oils. Results : Changes in the physiological indices. The mean deviation of skin pH was $5.58{\pm}0.47$ points before using aroma oils and $5.53{\pm}0.45$ points after 2 weeks, no statistical significance was found(p=0.221). MD was $5.36{\pm}0.41$ points after 4 weeks using aroma oils, which was statistically significant decrease of 0.22 points(p=0.001) Changes on the Pruritus Score Scale. A modified scale of the Pruritus Score Scale(Duo, 1987) was used to measure the severity, location, frequency, and the inconveniences of daily life due to prurius. The maximum scale of severity was 4 points, the full marks of location was 2 points, the full marks of frequency was 3 points, the full marks of inconveniences of daily life due to pruritus was 3 points. The scores ranged from 0 to 12, with 12 indicating the most severe pruritus. There was no statistical difference in severity and frequency score at 4 weeks later(severity p=0.097, frequency p=0.633). A statistically significant difference was found in the score of location and the inconveniences of daily life due to pruritus(each p=0.003). Conclusion : Generally speaking, the patient suffering from renal itch is the higher than normal in skin pH levels. that means to show alkaline condition of skin surface. In some case in this study, skin pH levels was rather lower than normal levels when measured actually patients suffering from renal itch by skin pH meter. But in this study post-test skin pH levels decreased, showing the contribution of aromathrapy to acidic condition of skin surface in suffering from renal itch. It seems to be some help to cure a pruritus and also have no ill effects on aroma oils.

• 한국지역지리학회지
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• 제17권1호
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• pp.58-74
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• 2011

본 연구는 국내 외국인직접투자기업의 제조업에 적합한 입지결정요인을 추출하여 AHP 분석기법(Analytic Hierarchy Process)을 통해 집단별, 업종별, 기업규모별, 입지유형별로 입지요인의 중요도와 우선순위를 분석하고 시사점을 도출하는데 목적이 있다. 본 연구결과를 요약하면 다음과 같다. 첫째로, 전문가집단이 외국인직접투자기업을 바라보는 관점과 외국인직접투자기업에서 실제로 고려하고 있는 각 입지요인의 중요도와 우선순위에는 상당한 괴리가 있는 것으로 확인되어 전문가집단의 정보 비대칭 문제가 심각한 것으로 나타났다. 둘째로, 외국인직접투자기업에서는 투자동기와 연관되어 있는 경쟁우위요인과 경영전략요인의 중요도를 높게 평가하고 있다. 또한 기업규모별, 업종별, 입지유형별로 입지요인의 중요도와 우선순위에도 많은 차이가 있는 것으로 나타났다. 셋째로, 투자만족도와 입지요인간에는 유의한 상관관계가 있는 것으로 나타나 입지요인들이 긍정적인 영향력을 많이 받을수록 투자의 만족도가 높아진다는 것을 시사하고 있다. 또한 투자기업에서는 노동의 유연성 부족과 우수인력의 확보문제를 가장 큰 경영상의 애로사항으로 인식하고 있었다. 넷째로, 입지의사결정에 필요한 정보의 원천에 관한 조사에서 행정당국보다는 이미 국내에 진출하여 사업을 영위하고 있거나 철수한 경험이 있는 선행의 투자기엽으로부터 입지정보를 수집하는 사례가 많은 것으로 나타났다. 아울러 가장 영향력이 높은 의사결정계층으로는 최고경영자로 확인되어 입지결정과 같은 전략적 정책결정들은 실무책임자보다는 최고경영층과의 관계 마케팅이 더욱 더 중요하다는 것을 확인하였다.

• 대한조선학회논문집
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• 제57권1호
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• pp.35-44
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• 2020

Propeller cavitation extent, pressure fluctuation induced by cavitation, pressure distribution on propeller blade, total velocity distribution and nominal wake distribution for a MR Taker were computed in both conditions of model test and sea trial using a code STAR-CCM⁺. Then some of the results were compared with model test data at LCT and full-scale measurement (Ahn et al (2014); Kim et al (2014)] in order to confirm the availability of a numerical prediction method and to get the physical insight of local flow around a ship and propeller. The nominal wake distributions computed and measured by LDV velocimeter on the variation of on-coming velocity show the wake contraction characteristics proposed by Hoekstra (1974). The numerical prediction of propeller cavitation extent on a blade angular position and pressure fluctuation level on each location of pressure sensors are very similar with the experimental results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.286-290
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• 2011

This paper introduces the optimum macro-siting of a potential site for an offshore wind farm around Jeju Island using the RDAPS sea wind model. The statistical model was developed by analyzing the sea wind data from RDAPS model, and the meso-scale digital wind map was prepared. To develop the high resolution spatial calibration model, Artificial Neural Network(ANN) models were used to construct the wind and bathymetric maps. Accuracy and consistency of wind/bathymetric spatial calibration models were obtained using analysis of variance. The optimization problem was defined to maximize the energy density satisfying the criteria of maximum water depth and maximum distance from the coastline. The candidate site was selected through Genetic Algorithm(GA). From the results, it is possible to predict roughly a candidate site location for the installation of the offshore wind jam, and to evaluate the wind resources of the proposed site.

• 인터넷정보학회논문지
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• 제10권5호
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• pp.183-194
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• 2009

본 논문에서는 인터넷상에 업로드되는 음란 영상물을 차단하기 위해 활동적 형태 모델(active shape model)을 이용한 유해 영상 탐지 방법을 제안한다. 본 논문에서는 활동적 형태 모델을 이용하여 가슴선의 형태를 주성분 분석(Principle Component Analysis)과 정렬을 통해서 학습하고, 각 제어점에 대응하는 화소값 분포를 학습한다. 그리고 학습된 형태와 화소값 분포를 이용하여 가슴선을 찾는다. 본 논문에서는 형태 모델의 초기 위치를 정확하게 선택하기 위해 스케일, 회전, 이동에 관한 파라미터를 추출한다. 이 정보를 획득하기 위해서 본 논문에서는 유두 부분의 위치를 찾고, 유두 위치로부터 모든 방향으로 방사하여 후보 가슴선을 찾는다. 이와 같이 검출한 가슴선 정보를 이용하여 스케일과 회전 값을 찾아 평균 형태(mean shape)를 위치시키고, 활동적 형태 모델을 반복적으로 탐색한다. 최종적으로 수렴한 형태의 제어점(landmark)과 후보 가슴선과의 거리 평균을 계산하여 유해영상의 유무를 판단한다.

• Wind and Structures
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• 제14권4호
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• pp.301-319
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• 2011

The full-scale measurements are compared with the wind tunnel test results for the long-span roof latticed spatial structure of Shenzhen Citizen Center. A direct comparison of model testing results to full-scale measurements is always desirable, not only in validating the experimental data and methods but also in providing better understanding of the physics such as Reynolds numbers and scale effects. Since the quantity and location of full-scale measurements points are different from those of the wind tunnel tests taps, the weighted proper orthogonal decomposition technique is applied to the wind pressure data obtained from the wind tunnel tests to generate a time history of wind load vector, then loads acted on all the internal nodes are obtained by interpolation technique. The nodal mean wind pressure coefficients, root-mean-square of wind pressure coefficients and wind pressure power spectrum are also calculated. The time and frequency domain characteristics of full-scale measurements wind load are analyzed based on filtered data-acquisitions. In the analysis, special attention is paid to the distributions of the mean wind pressure coefficients of center part of Shenzhen Citizen Center long-span roof spatial latticed structure. Furthermore, a brief discussion about difference between the wind pressure power spectrum from the wind tunnel experiments and that from the full-scale in-site measurements is compared. The result is important fundament of wind-induced dynamic response of long-span spatial latticed structures.

• Smart Structures and Systems
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• 제26권1호
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• pp.35-47
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• 2020

This paper proposes the use of transmissibility functions combined with a machine learning algorithm, Artificial Neural Networks (ANNs), to assess damage in a truss bridge. A new approach method, which makes use of the input parameters calculated from the transmissibility function, is proposed. The network not only can predict the existence of damage, but also can classify the damage types and identity the location of the damage. Sensors are installed in the truss joints in order to measure the bridge vibration responses under train and ambient excitations. A finite element (FE) model is constructed for the bridge and updated using FE software and experimental data. Both single damage and multiple damage cases are simulated in the bridge model with different scenarios. In each scenario, the vibration responses at the considered nodes are recorded and then used to calculate the transmissibility functions. The transmissibility damage indicators are calculated and stored as ANNs inputs. The outputs of the ANNs are the damage type, location and severity. Two machine learning algorithms are used; one for classifying the type and location of damage, whereas the other for finding the severity of damage. The measurements of the Nam O bridge, a truss railway bridge in Vietnam, is used to illustrate the method. The proposed method not only can distinguish the damage type, but also it can accurately identify damage level.

• 한국건설관리학회논문집
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• 제12권2호
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• pp.12-20
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• 2011

최근 국가경제규모의 성장과 더불어 단위 건설현장의 규모도 대형화, 복합화되어 가고 있다. 이에 건설시장은 공기단축, 원가절감, 품질개선을 요구하게 되었고, 보다 효율적인 프로젝트 관리를 위해 첨단기술을 적용한 연구가 다양하게 진행되고 있다. 특히, 건설현장의 인력, 자재, 장비 등의 다양한 자원에 대한 실시간 위치추적기술인 RTLS기술은 안전관리에 효과적인 것으로 평가받고 있다. 하지만 건축공사 뿐만아니라 해양, 도시 및 타 산업분야에서 연구와 적용이 이뤄지는 것과는 달리 협소하고 위험요소가 많은 터널공사에 대한 연구는 거의 전무한 실정이다. 따라서 본 연구에서는 RTLS기술을 이용한 터널현장에서의 안전관리를 위한 모델을 제시하고, 이의 현장적용성 검토를 실시하였다. 적용성 검토 결과, 제시된 모델은 발생되는 일부의 오차로 인해 현장에 바로 적용하기 힘드나 하드웨어기술의 발전과 위치보정에 대한 노력으로 극복할 수 있을 것으로 판단된다. 본 연구를 통해서 토목분야의 효율적인 프로젝트관리는 물론 안전관리의 방향을 제시하는데 이바지할 것으로 사료된다.

• KIEAE Journal
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• 제12권4호
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• pp.47-57
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• 2012

The purpose of this study is to develop an aging friendly guideline aging friendly outdoor exercise environment in Universal design aspect. The aim for this guideline is to suggest a creative method to cope with forthcoming aging society and meet the various demands of all park users. Documentary survey and field survey were used to extract notion of universal design and aging friendly design; based from the extracted notions three types of exercise environment were suggested, Small scale, Medium scale and Large scale. The significant of this guideline is as fallow: First, negative aspects of aging friendly design can be eliminated by adopting universal design; therefore the guideline can have social integration aspect. Second, reflected needs of residents can be suggested on the guideline; and it was extracted from documentary survey, PPP UD checklist and field survey. Third, classifying universal design and aging friendly design in one guideline can enhance ability to manage various composition of population. Fourth, by studying young child and old people's likeness and parallel resemblance, design guideline for forthcoming aging society can be suggested. Fifth, from three developed exercise environments, the guideline can be applied into different conditions of location. Sixth, canopy type design model can be very useful for old people.