이중편파 레이더의 강우 추정 알고리즘별 수문학적 적용성 평가

이명진,이충기,유영훈,곽재원,김형수,Lee, Myungjin,Lee, Choongke,Yoo, Younghoon,Kwak, Jaewon,Kim, Hung Soo 한국수자원학회 2021 한국수자원학회논문집 Vol.54 No.1

Recently, many studies have been conducted to use the radar rainfall in hydrology. However, in the case of weather radar, the beam is blocked due to the limitation of the observation such as mountain effect, which causes underestimation of the radar rainfall. In this study, the radar rainfall was estimated using the Hybrid Sacn Reflectivity (HSR) technique for hydrological use of weather radar and the runoff analysis was performed using the GRM model which is a distributed rainfall-runoff model. As a result of performing the radar rainfall correction and runoff simulation for 5 rainfall events, the accuracy of the dual-polarization radar rainfall using the HSR technique (Q_H_KDP) was the highest with an error within 15% of the ground rainfall. In addition, the result of runoff simulation using Q_H_KDP also showed an accuracy of R2 of 0.9 or more, NRMSE of 1.5 or less and NSE of 0.5 or more. From this study, we examined the application of the dual-polarization radar and this results can be useful for studies related to the hydrological application of dual-polarization radar rainfall in the future.

레이더 강우 앙상블과 유출 블랜딩 기법을 이용한 최적 유출 수문곡선 산정

이명진,강나래,김종성,김형수,Lee, Myungjin,Kang, Narae,Kim, Jongsung,Kim, Hung Soo 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.3

최근 기후변화로 인한 국지성 호우 및 태풍 피해가 자주 발생하고 있다. 이와 같은 피해를 저감하기 위해서는 정확한 강우의 예측과 홍수량 산정이 필요하다. 그러나 지점 및 레이더 강우 시 공간적 오차를 포함하고 있고, 유출 모형에 의한 유출수문곡선 역시 보정을 실시하더라도 관측유량과 오차를 가지고 있어 불확실성이 존재한다. 따라서 본 연구에서는 확률론적 강우 앙상블을 생성하여 강우의 불확실성을 확인하였다. 또한 유출 결과를 통해 수문 모형의 불확실성을 확인하였고, 블랜딩 기법을 이용하여 하나의 통합된 유출 수문곡선을 제시하였다. 생성된 강우앙상블은 강우강도 및 지형적인 영향으로 레이더가 과소 관측이 될 때, 강우 앙상블의 불확실성이 큰 것을 확인하였고, 블랜딩 기법을 적용하여 산정된 최적 유출 수문곡선은 유출모형의 불확실성을 크게 줄이는 것으로 나타났다. 본 연구 결과를 활용한다면, 정확한 홍수량 산정 및 예측을 통해 집중호우로 인한 피해를 줄일 수 있을 것으로 판단된다. Recently, the flood damage by the localized heavy rainfall and typhoon have been frequently occurred due to the climate change. Accurate rainfall forecasting and flood runoff estimates are needed to reduce such damages. However, the uncertainties are involved in guage rainfall, radar rainfall, and the estimated runoff hydrograph from rainfall-runoff models. Therefore, the purpose of this study is to identify the uncertainty of rainfall by generating a probabilistic radar rainfall ensemble and confirm the uncertainties of hydrological models through the analysis of the simulated runoffs from the models. The blending technique is used to estimate a single integrated or an optimal runoff hydrograph by the simulated runoffs from multi rainfall-runoff models. The radar ensemble is underestimated due to the influence of rainfall intensity and topography and the uncertainty of the rainfall ensemble is large. From the study, it will be helpful to estimate and predict the accurate runoff to prepare for the disaster caused by heavy rainfall.

의미망 제약식언어를 기반으로 한 인터넷 쇼핑 의사결정 틀

이명진(Myungjin Lee),김학진(Hak-Jin Kim),김우주(Wooju Kim) 한국경영과학회 2008 韓國經營科學會誌 Vol.33 No.3

Semantic Web society initially focused only on data but has gradually moved toward knowledge. Recently rule beyond ontology has emerged as a key element of the Semantic Web. All of these activities are obviously aiming at making data and knowledge on the Web sharable and reusable between various entities around the world. If one of ultimate visions of the Semantic Web is to increase human's decision making quality assisted by machines, there is a missing but important part to be shared and reused. It is knowledge about constraints on data and concepts represented by ontology which should be emphasized more. In this paper, we propose Semantic Web Constraint Language (SWCL) based on OWL and show how effective SWCL can be in representing and solving an internet shopper's decision making problem by an implementation of a shopping agent in the Semantic Web environment.

이중 - 링크 네트워크상에서 실시간 메시지 스케듈링 기법

이명진(MYUNGJIN LEE),이정배(JEONGBAE LEE) 한국정보과학회 1993 한국정보과학회 학술발표논문집 Vol.20 No.2

컴퓨터 네트워크들은 여러가지 다양한 서비스의 지원이 요구된다. 컴퓨터 네트워크을 통해서 전송되는 음성, 화상 기타 긴급 전송과 관련된 메시지들은 명확한 전송제한시간을 갖는 실시간 통신 기법이 요구된다. 본 논문에서는 예약기법을 이용한 이중-링크 네트워크에서 사용하는 실시간 통신기법을 개선하여, 실시간 메시지 전송시에 전송제한시간을 기초로 하여 메시지 전송순위를 결정하는 스케듈링 기법을 제시한다. 전자의 기법과 제시된 기법의 성능을 비교 분석하기 위하여 SLAM II언어를 사용한 시뮬레이션을 통해, 시스템 부하의 변화에 따른 메시지 상실율을 비교 분석 중에있다.

시맨틱 웹 환경에서의 부분선형 제약지식표현을 위한 SWCL의 확장

이명진(Myungjin Lee),김우주(Wooju Kim),김학진(Hak-Jin Kim) 한국경영과학회 2012 韓國經營科學會誌 Vol.37 No.4

The Semantic Web technology, purporting to share, to reuse and to process by machines data stored in the Web environment, incessantly evolves to help human decision making; in particular, decision making based on data, or quantitative decision making. This trend drives researchers to fill the gap with strenuous efforts between the current state of the technology and the terminus of this evolution. The Semantic Web Constraint Language (SWCL) together with SWRL is one of these endeavors to achieve the goal. This paper focuses particularly on how to express the piecewise linear form in the context of SWCL. The importance of this ingredient can be fortified by the fact that any nonlinear expression can be approximated in the piecewise linear form. This paper will also provide the information of how it will work in the decision making process through an example of the Internet shopping mall problem.

로잉 구동방식 응용 레저용 소형 패들보트 디자인

이명진 ( Myungjin Lee ),이호숭 ( Hosoong Lee ) 한국산업디자이너협회 2018 산업디자인학연구 Vol.12 No.4

Unlike overland travel facilities, water leisure facility location environment conditions mostly are inaccessible and unfavorable for mobility-impaired people. This is because leisure facility environments and appropriate water leisure facilities are not established to meet the characteristics of mobility-impaired people, who are either physically disabled or use mobility aids. This study aims to propose a small leisure paddle boat for mobility-impaired people who can hardly participate in water leisure activities. To that end, this study observed and surveyed the use situations of the existing popular water leisure mode, duck boat(pedal-driven duck-shaped boat), and surveyed similar overseas products to identity their standards, driving principles, convenience, etc. Thus the survey results were referred to in the basic specifications of the proposed boat body. Further, based on the universal design concept, an original power train was developed using the propelling principle of rowing boats. For its characteristics, the driving train can be driven only in one direction according to the rider's physical position and convenience when the front passenger performs propelling action, using his or her hands and feet. In addition, the wheel-chaired passenger in the rear space of the boat can have the pleasure of participating in driving the boat, using his or her hands and arms alone, together with the front passenger.

분산 저장소 구조에서 안전한 데이터 접근을 위한 키 관리 메커니즘

이명진(Myungjin Lee),채기준(Kijoon Chae) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.2

분산 저장소의 데이터를 여러 사용자가 공유하는 시스템에서는 데이터 보호를 위해 데이터를 암호화하여 저장한다. 사용자가 데이터를 서비스받기 원하면 사용자에게 데이터를 암호화한 키를 공개한다. 이러한 시스템에서는 기존의 사용자가 시스템을 탈퇴할 경우 그 사용자가 접근가능했던 데이터가 위험에 노출되게 된다. 이를 막기 위해서 시스템을 탈퇴한 사용자가 접근 가능했던 모든 데이터 각각에 대해 다른 키를 사용하여 암호화를 해야 한다. 이 과정은 데이터의 크기가 기가바이트 혹은 테라바이트에 달할 경우 막대한 오버헤드를 수반한다. 이러한 문제점을 해결하기 위해 본 연구에서는 사용자에게 데이터 키를 노출하지 않고 사용자가 데이터를 서비스 받을 수 있는 메커니즘을 제안한다.

연료전지 전기자동차 전력 구동시스템 분석 및 전동기 구동시스템 제어기 설계

이명진(Myungjin Lee),박인덕(Induck Park),김시경(Sikyung Kim) 대한전기학회 2004 대한전기학회 학술대회 논문집 Vol.2004 No.11

600 MPa급 플럭스 코어드 아크 용접금속의 저온균열에 미치는 예열 온도 및 미세조직의 영향

이명진 ( Myungjin Lee ),조경목 ( Kyungmox Cho ),강남현 ( Namhyun Kang ) 대한금속재료학회(구 대한금속학회) 2016 대한금속·재료학회지 Vol.54 No.4

The influence of preheat and microstructure on cold cracking for high strength and low hydrogen flux cored arc (FCA) weld metal was analyzed using Y-groove test. The weld microstructure consisted of acicular ferrite and martensite. As the preheat temperature increased, the volume fraction of acicular ferrite increased and that of martensite decreased, thereby decreasing the volume expansion during the transformation from austenite to martensite. This result was consequently associated with a reduced cold cracking ratio. Cold cracking progressed mainly along the prior austenite grain boundary of martensite, and the fractograph of cold cracking consisted of intergranular fractures and quasi-cleavage fractures. With increasing the preheat temperature and decreasing the carbon equivalent, the fraction of intergranular fractures decreased and quasi-cleavage fractures increased. The microstructure related with intergranular fractures was martensite; quasi-cleavage fractures were associated with acicular ferrite.

Matlab/Simulink를 이용한 IPMSM 제어 시스템의 고장 모델링 및 분석

이명진(Myungjin-Lee),최연수(Yeonsu-Choi),이열경(Yeol-Kyeong Lee),허진(Jin Hur) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.11

In this study, a method of modeling using Matlab/Simulink for partial irreversible magnetization fault and the stator inter-turn fault that occur most frequently in permanent magnet synchronous motors is developed, the developed simulation model is applied for analyzing the characteristics of the normal state and the fault state. In a permanent magnet motor, the irreversible demagnetization fault of permanent magnets and inter-turn short fault are representative causes of fault. However, for analyzing the characteristics due to the fault, it is difficult to use electromagnetic analysis or complex formulas using FEM. In this study, the voltage and current for these failures are compared using the proposed simple equivalent circuit.