• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.21-22
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• 2011

In this study, an analytical algorithm for collision avoidance is proposed, which is applicable to designing collision avoidance maneuvers for two encountering ships. The minimum separation distance is defined and an appropriate maneuver sequence is computed for safe and effective collision avoidance. Two approaches: 1) collision avoidance through speed change and 2) collision avoidance through heading change, are considered, and the initiation point of the avoidance maneuver is computed analytically using the geometric configuration of the two encountering ships. To verify the feasibility of the proposed algorithm, numerical simulations are carried out using a set of ship-to-ship encountering scenarios.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.229-231
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• 2004

대량의 정보를 빠르게 처리하기 위해 DBMS의 성능관리는 필수적이고 이를 뒷받침하기 위해 많은 툴들이 있다. 이들 제품 중의 하나인 국산 Maxgauge는 오라클 데이터베이스의 성능 현황이 어떤지 조회하고, 설정된 임계 값을 초과하는지 강시하고, 성능 문제 발생시에 원인을 추적하는 기능을 제공한다. 하지만 이는 설치의 번거로움과 국한된 환경에서만 서비스를 받을 수 있다는 한계가 있기 때문에 우리는 웹을 통해서도 시간과 장소에 구애받지 않고 성능을 관리할 수 있게끔 클라이언트/서버 버전을 웹 버전으로 설계 침 구현하였다. 1)서론 2) MAXGAUGE 소개 3) Web버전 설계 및 구현 4) 결론 및 향후구현방향 5) 참고문헌

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.347-348
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• 2022

자율운항선박 도입에 관한 논의가 국제해사기구에서 본격적으로 시작됨에 따라 자율운항선박 관련 기술개발이 세계적으로 활발하게 진행되고 있다. 그러나, 통신, 보안, 고장진단, 유지보수 등의 기술개발이 아직 미흡하여, 자율운항선박의 상용화까지는 많은 시간이 소요될 것으로 예상된다. 이러한 기술들은 문제가 발생할 경우 선박에 막대한 피해를 발생시킬 수 있으며, 특히, 연안을 항해하는 선박보다는 대양을 항해하는 선박에 더 치명적이기 때문이다. 본 연구에서는 대양항해 시 자율운항선박에 발생할 수 있는 문제들을 극복하기 위한 방안으로 여러 척의 선박을 하나의 그룹으로 묶어 항해하는 그룹항법시스템을 제안한다. 하나의 그룹은 한 척의 유인선박인 리더선박과 여러 척의 무인선박인 추종선박으로 구성되어 있으며, 항해하는 동안 일직선 형태를 유지한다. 리더선박은 출발지에서 목적지까지 미리 설정된 변침점을 따라 항해하며, 추종선박은 리더선박의 경로를 추종하여 항해한다. 선박의 침로를 제어하기 위한 타각 제어기는 선박에서 주로 사용되는 PD 제어기를 구현하여 사용하였다. 그룹항법시스템을 검증하기 위해 선박해양플랜트연구소에서 공개한 KVLCC2의 축소 모형인 L-7 모델을 사용하여 시뮬레이션을 진행하였다.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.603-610
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• 2000

Climate factors such as rainfall, temperature, wind, humidity, and solar radiant heat affect soil erosion. Among those factors, rainfall influences soil erosion to the most extent. The kinetic energy of rainfall breaks away soil particles and the water flow caused by the rainfall entrains and transport them downstream. In order to estimate soil erosion, therefore, it is important to determine the rainfall erosivity. In this study, the annual average Rainfall Erosivity(R) in Korea, an important factor of the Universal Soil Loss Equation(USLE) and Revised Equation(RUSLE), has been estimated using the nationwide rainfall data from 1973 to 1996. For this estimation, hourly rainfall data at 53 meterological stations managed by the Meterological Agency was used. It has been found from this study that the newly computed values for R are slightly larger than the existing ones. It would be because this study is based on the range of rainfall data that is longer in period and denser in the number of gauging stations than what the existing result used. The final result of this study is shown in the form the isoerodent map of Korea.

• Korean Journal of Oriental Medicine
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• v.3 no.1
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• pp.183-197
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• 1997

In order to detect the safety and effect of various aqua-acupunctures from Scutellariae Radix, the modifications of boiling, filtration and dilution were employed for the manufacture of aqua-acupunctures. We injected 0.2cc of aqua-acupunctures into Joksamri (足三里) of rat, repeatedly. We compared subacute toxicity of them with saline group, distilled water(D.W.) group, acupuncture group and control group. The results were summarized as follows: 1. The groups were all healthy and alive, and there was no special abnormality in physical condition and autopsy. And there were not any toxic symptoms in repeating application of aqua-acupunctures to the rat, including changes of body weight, organ weight, haematological examination and serum biochemical test. 2. There was slight change of body weight in acupuncture group : We could see significance after 3 days(p<0.05) and after 7 days(p<0.001) in body weight loss. After 9 days, all tested groups were suppressed in body weight increment. 3. Result of organ weight : In Palkang aqua-acupuncture(D-2 group), saline group and acupuncture group there were some statistical significance. Especially, acupuncture group revealed significant result in liver and spleen than aqua-acupunctures. From this result, we could suggest that the efficacy of acupuncture was preceded herbal medicine. 4. In serum biochemical test, we examined glucose(GLU), triglyceride(TG) and cholesterol(CHOL). In comparison with control group, the diluted 10 times of Hwanggum aqua-aqupuncture$({\times}10\;group)$ was recognized significant decrease of glucose, but the diluted 100 times of Hwanggum aqua-acupuncture$({\times}100\;group)$, D-2 group, saline group were confirmed significant increment. There was not any meaningful change of CHOL in all of tested group, excepting the acupuncture group was exhibited statistically significant decrease(p<0.05). In TG level all tested group except complex injection of standard compound(CPA group) and HG, there were significant value iii statistically. The diluted solution was more significant decrease than Hwanggum aqua-acupuncture(HG). The mutual relationship of components of aqua-acupunture tended to decrease level of TG, regardless of its concentration. In acupunture guoup, we gained some interesting result In meaningful decrease in 7G. 5. Haematological examination showed significant increment of granulocytes(GR) in all tested groups except Hwanggum aqua-acupuncture. And the diluted solutions of HG expressed very high increment of them(p<0.001). The GR and Mean Corpuscular Volume(MCV) of acupuncture group showed statistical significance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.639-650
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• 2022

In areas where large-scale sediment transport occurs, it is important to apply appropriate countermeasure method because the phenomenon tends to accelerate by time duration. Among the various countermeasure methods applied so far, beach nourishment needs to be reviewed as an erosion prevention measure because the erosion pattern is mitigated and environmentally friendly depending on the particle size. In the case of beach nourishment. a detailed review is required to determine the size, range, etc., of an appropriate particle diameter. In this study, we investigated the characteristics of the related topographic change using the change in the particle size of nourishment materials, the application of partial area, and the condition under the coexistence of waves and wind as variables because those factors are hard to be analyzed and interpreted within results and limitation of that the existing numerical models are not able to calculate and result out so that it is required that phenomenon or efforts are reviewed at the same time through physical model experiments, field monitoring and etc. So we attempt to reproduce the tendency of beach erosion and deposition and predict possible phenomena in the future using machine learning techniques for phenomena that it is not able to be interpreted by numerical models. we used the hydraulic experiment results for the training data, and the accuracy of the prediction results according to the change in the training method was simultaneously analyzed. As a result of the study it was found that topographic changes using machine learning tended to be similar to those of previous studies in short-term predictions, but we also found differences in the formation of scour and sandbars.

• Journal of Acupuncture Research
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• v.25 no.1
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• pp.211-219
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• 2008

목적 : 전통적으로 태충($LR_3$)과 양릉천($GB_{34}$)은 운동기능과 관련된 질환에 사용되어 왔다. 우리는 두뇌에 신경독을 주입하여 파킨슨병 쥐모델을 제작하였고, 쥐는 운동기능이 손상되고 도파민성 신경세포가 선택적으로 소멸하였다. 병증 모델 쥐에게 태충과 양릉천에 자침한 결과 운동기능이 개선되고 신경세포보호효과가 나타남을 관찰한 바 있다. 이에 실제로 태충과 양릉천에 자침하여 운동기능과 관련된 추체외로 영역에서 신경의 활성화가 나타나는지를 fMRI를 통하여 관찰하였다. 방법 : 자침은 수기침을 선택하였으며, 혈위는 (1) 태충, (2) 양릉천, (3) 태충+양릉천의 세군데를 설정하였고, 자침에 대한 대조자극으로 피부자극을 채택하였다. fMRI 스캐너는 3T를 사용하였고 뇌신경 활성화의 신호는 BOLD(blood-oxygen-level dependant)를 관찰하였다. 두뇌에서 관찰부위는 중뇌를 중심으로 추체외로로 한정하였다. 결과 : 태충에 자침하였을 때 두뇌의 substantia nigra, subthalamic nucleus, red nucleus, pons 등이 활성화 되었다. 양릉천에 자침하였을 때 substantia nigra, subthalamic nucleus, caudate nucleus, thalamus가 활성화 되었다. 태충과 양릉천에 동시에 자침하였을 때는 substantia nigra, subthalamic nucleus, red nucleus, globus pallidus가 활성화되었다. 대조자극에 의해서는 위의 영역들이 활성화되지 않았다. 결론 : 태충, 양릉천, 태충+양릉천 자극은 대뇌에서 추체외로 영역을 활성화시키며 특히 substantia nigra의 활성화는 파킨슨병과 같은 질환의 조절가능성을 시사한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3307-3314
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• 2012

The annual energy demand of the standard rural house models was analyzed using the DesignBuilder. Indoor temperature set-point, U-value of outer wall, type of window, and degree of ventilation were selected as simulation parameters. In all the simulation cases, heating energy demand was higher than cooling energy demand regardless of the building size. When the lower U-value of the outer wall was applied to account for the thicker insulation layer, heating energy demand was decreased while cooling energy demand was increased. However, it is better to reduce the area of outer wall which is directly exposed to outdoor air because reducing the U-value of the outer wall is not effective in decreasing heating energy demand. Among the four different window types, the double skin window is most favorable because heating energy demand is the lowest. For a fixed infiltration rate, higher ventilation rate resulted in an increased heating energy demand and had minor impact on cooling energy demand. As long as the indoor air quality is acceptable, lower ventilation rate is favorable to reduce the annual energy demand.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.387-387
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• 2020

본 연구에서는 LIP에 의한 극한강우로부터 발생되는 극한홍수량을 산정한다. Huff 형 강우시간 분포를 기후변화 시나리오별로 적용하고, 원전주변지역에서의 상세한 토지이용조건의 변화를 고려하여 빈도별 홍수량을 산정한다. 외부침수해석의 정교화를 위한 상세 지형자료를 구축하고, 원자력발전소 부지의 상세 DEM 자료를 생성한다. 이를 위해서 원자력발전소 부지에서 건물, 연석, 도로 등의 영향을 분석하고 토지이용상황에 따른 조도계수를 산정한다. 또한 원전지역에서의 외부침수재해도 분석을 위해서 국립해양조사원에서 검토한 기후변화를 고려한 조위분석 자료를 외부경계조건으로 설정한 후 부지에 대한 2차원 수리분석을 실시한다. 침수심, 침수유속, 침수시간, 침수동압력 분석 등 2차원 침수해석결과를 바탕으로 발생빈도별 침수심, 침수강도 등의 정량적인 분석을 통해서 빈도별 재해도 곡선을 개발한다. 그리고 원전지역에서의 외부 침수에 대한 대표적인 재해도 곡선을 산정하기 위하여 재현기간별 지속시간에 따른 침수심을 분석하고 정리한다. 재현기간별 침수심에 대해 확률 분포형을 적용하기 위해서 AIC검증을 통한 분포형의 적합성을 분석을 실시한다. 또한 재현기간별 지속시간에 따른 침수심들 간의 상관관계를 분석하여 분포형에 적용한다. 적용된 분포형을 몬테칼로 시뮬레이션을 통한 대표적인 확률론적 외부 침수 재해도 곡선을 산정한다. 본 연구를 바탕으로 원전 부지 및 그 부속 시설물(SSC)의 홍수방지 기능과 홍수 대비 시설물에 대한 적용 절차의 신뢰성, 홍수 저감 및 대응 전략에 대한 정량화가 가능하여 원전 홍수 위험에 대한 정량적인 평가 지원이 가능하겠다. 고려할 외부 홍수와 관련된 원전 내부시설 및 장비에 대한 상세한 모델링 절차, 특정 시나리오에 대한 홍수 방지 및 예방과 관련한 SSC의 정량화, 홍수저감 활동과 관련된 통제실 외부 시설물에 대한 수동 조작에 대한 평가가 이루어질 수 있겠다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6C
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• pp.349-358
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• 2008

In performing the reliability analysis for predicting the settlement with time of alluvial clay layer at Kobe airport, the uncertainties of geotechnical properties were examined based on the stochastic and probabilistic theory. By using Terzaghi's consolidation theory as the objective function, the failure probability was normalized based on AFOSM method. As the result of reliability analysis, the occurrence probabilities for the cases of the target settlement of ${\pm}10%,\;{\pm}25%$ of the total settlement from the deterministic analysis were 30~50%, 60%~90%, respectively. Considering that the variation coefficients of input variable are almost similar as those of past researches, the acceptable error range of the total settlement would be expected in the range of 10% of the predicted total settlement. As the result of sensitivity analysis, the factors which affect significantly on the settlement analysis were the uncertainties of the compression coefficient Cc, the pre-consolidation stress Pc, and the prediction model employed. Accordingly, it is very important for the reliable prediction with high reliability to obtain reliable soil properties such as Cc and Pc by performing laboratory tests in which the in-situ stress and strain conditions are properly simulated.