HALE-BOPP 혜성의 CN, C2 분자 생성율

손동훈,김상준,김주현,김강민,성언창,형식,Son, Dong-Hoon,Kim, Sang-Joon,Kim, Joo-Hyun,Kim, Kang-Min,Sung, Eon-Chang,Hyung, Siek 한국천문학회 1997 天文學論叢 Vol.12 No.1

We obtained the CN($\Delta_V=0$) and $C_2(\Delta_V=0,\;\pm1$) spectra of comet Hale-Bopp(C/1995 O1) at the Kyunghee Observatory and Bohyunsan Astronomical Observatory between March 7 and May 12, 1997 The fluxes for each molecular band were measured and then the production rates and column densities of CN and $C_2$ were calculated using a simple model. The resultantproduction rates of CN and $C_2$ are logQ(CN)=27.4 at r=0.94 AU(preperihelion) and $logQ(C_2)=27.3$ at r=0.94 AU(postperihelion), respectively.

다기간 자료포락분석을 이용한 전기차 충전소 효율성 변화 분석

손동훈(Dong-Hoon Son),강영수(Yeong-Su Gang),김화중(Hwa-Joong Kim) 한국산업경영시스템학회 2021 한국산업경영시스템학회지 Vol.44 No.2

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

Heuristics for Rich Vehicle Routing Problem : A Case of a Korean Mixed Feed Company

손동훈(Dong Hoon Son),․,김화중(Hwa-Joong Kim) 한국산업경영시스템학회 2019 한국산업경영시스템학회지 Vol.42 No.1

The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that he proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.

항공 특송화물 탑재계획을 위한 알고리즘

손동훈(Dong-Hoon Son),김화중(Hwa-Joong Kim) 한국산업경영시스템학회 2016 한국산업경영시스템학회지 Vol.39 No.3

For air express service providers offering various express delivery services such as overnight delivery and next-business day delivery services, establishing quickly cargo loading plans is one of important issues owing to the characteristics of air express business, i.e., a short amount of time is available to complete all cargo loading operations before flight departure after receiving air express containers, pallets and bulks. On the other hand, one of major concerns in the air cargo loading planning is to make a plan that insures the stability of an aircraft to avoid take-off, flight, and landing accidents. To this end, this paper considers an air cargo loading planning problem, which is the problem of determining locations in the aircraft cargo space where air containers, pallets and bulks to be loaded while insuring the aircraft stability, motivated from DHL and Air Hong Kong. The objective of the problem is to maximize the total revenue gained from loading air express containers, pallets and bulks. To solve the problem, this paper suggests a simulated annealing algorithm to overcome impracticality of the integer programming model developed by a previous study requiring excessive computation time. The results of computational experiments show that the heuristic algorithm is a viable tool for establishing express cargo loading plans as giving robust and good solutions in a short amount of computation time. Scenario analyses are performed to investigate the effect of the current activities of air express carriers on the revenue change and to draw practical implications for air express service providers.

자료포락분석을 이용한 전기차 충전소 운영효율성 평가

손동훈(Dong-Hoon Son),강영수(Yeong-Su Gang),김화중(Hwa-Joong Kim) 한국산업경영시스템학회 2020 한국산업경영시스템학회지 Vol.43 No.3

Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

군용 차량 탑재 체계의 진동 및 충격 분석 기법에 대한 연구

손동훈(Dong-Hun Son),강광희(Kwang-Hee Kang),최지호(Ji-Ho Choi),박도훈(Do-Hoon Park),황대진(Dae-Jin Whang) 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.4

Recently developed weapons systems are developed primarily as a vehicle-mounted tactical mobility or securing and increasing operability with equipment. The weapon system is to be designed so that the vibration and shock transmitted to the insulation from the road surface. Therefore, military vehicles and is also a tendency to mount the most recently developed independent suspension. This recent trend is to have the need to look for the right to verify the vibration and shock testing of vehicle systems with the US military standard independent suspension for use in weapons development. In this study, it is confirmed whether test standard is suitable for performance verification of this system by comparing test results of the vibration and shock of the developed vehicle with US military standard specifications.

소년원생들의 우울증 예측에 기계학습을 적용한 예비연구

손동훈(Dong Hun Son),장진구(Jhin Goo Chang),송후림(Hoo Rim Song),이수영(Su Young Lee),이승훈(Seung Hoon Lee),방수영(Soo-Young Bhang),이미선(Mi-Sun Lee),김현수(Hyun-Soo Kim),홍민하(Minha Hong) 대한사회정신의학회 2021 사회정신의학 Vol.26 No.2

연구목적 : 청소년 범죄에서 정신건강의 문제와 범죄가 관련성이 높다는 것은 잘 알려져 있지만 국내에서는 아동청소년 범죄자들의 정신건강에 관한 연구가 거의 없다. 뿐만 아니라 아동청소년정신건강 영역에서 기계학습을 적용한 연구는 아직 초기단계이다. 본 예비연구에 서는 여자청소년 재소자들에서 정신건강 문제 중 우울증의 예측에 기계학습 알고리즘을 적용하여 적합한 지를 알아보고자 한다. 방 법 : 대상자는 청주소년원에 재소중인 87명의 여자청소년을 대상으로 하였다. 대상자들에게 설문지 패키지 (인구학적 정보, 범죄관련 정보, 자기보고척도 설문지(아동기부정적경험 설문지, 벡우울척도)를 배부하여 정보를 수집하였다. 기계학습 기법을 이용하여 수집된 재소자들의 기본 정보를 바탕으로 우울증을 예측할 수 있는 6개의 모델(Logistic regression, Random forest, Supportive vector machine, Decision tree, Nearest neighbor, Adaboost)을 생성하여 각 모델간의 예측 성능을 비교해 보았다. 결 과 : 대상자를 벡우울척도(절단점 13)로 군을 분류한 결과 정상군 18명(21%)과 우울증군 69명(79%)이었다. 6개 모델의 우울증 예측 정확도는 Logistic regression 81.8%, Random forest 81.8%, Supportive vector machine 68.18%, Decision tree 72.7%, Nearest neighbor 77.3%, Adaboost 63.6%였다. 그중에서 Random forest 모델의 AUC score는 0.75로 다른 모델들과 비교하여 가장 높았다. 결 론 : 본 연구는 재소청소년의 정신건강에 중점을 두어 현황을 파악하고,우울증의 예측에 기계학습 기법을 적용을 하여 높은 정확도를 확인하였다는 점에서 의의가 있다. 또한 취약계층의 정신건강 영역에 기계학습 기법을 적용하여 관리 및 감시에 적용 가능성에 대한 근거를 제공하였다. Objectives : It is well known that mental health problems and crime are highly related to youth crime, but there is little research on the mental health of young offenders in Korea. Furthermore, research on the application of machine learning in the mental health of children and adolescents is still novel. This preliminary study aims to investigate whether it is appropriate to apply machine learning algorithms to predict depression among female adolescent inmates. Methods : The subjects were 87 young females in Cheongju Juvenile Center. A questionnaire was distributed to the subjects to gather their demographic information and crime-related information, as well as their adverse childhood experiences and Beck depression inventory scores using self-reported scale questionnaires. Based on the collected information, six models (logistic regression, random forest, supportive vector machine, decision tree, nearest neighbor, Adaboost) that can predict depression were created to compare the predictive performance between models using machine learning techniques. Results : Results showed that 29 victims (25.7%) met the criteria of PTSD and 19 victims (16.8%) met the rigid criteria of PTSD. But, according to the subscales, 41 victims (36.3%) were diagnosed as PTSD. Victims with PTSD had more serious depression, anxiety, sleep disturbance, anger, social withdrawal and life stresses. Conclusion : This study identified the current mental health status of female inmates with high accuracy by applying machine learn-ing techniques to predict depression. The applicability of machine learning techniques to the management and surveillance of mental health in vulnerable groups was also highlighted.

군용 차량 탑재 캐비닛 구조물의 구조건전성 분석

손동훈(Dong-Hun Son),강광희(Kwang-Hee Kang),최지호(Ji-Ho Choi),박도훈(Do-Hoon Park) 한국소음진동공학회 2014 한국소음진동공학회 학술대회논문집 Vol.2014 No.10

The development of a vehicle-mounted radar to detect the location of enemy artillery is mainly mounted during operation to the mobility of the equipment and efficiency of utilization range. It is equipped with an electronic device responsible for the operation of the radar system. El ectronic equipments is performed functionality imparted without an error-specific in spite of disturbances such as vibration / shock caused by vehicle movement. Therefore, vibration / shock resistance is held to prevent damaging from vibration / shock generated from the outside environment during operation. In addition, a standardized and specified cabinet structure equipped with electronic equipment is placed in shelter to ensure additional safety for vibration / shock. In this study, it is evaluated by analytical method with vibration / shock resistance of the cabinet structures for ensuring structural safety factor is applied to the aluminum. It is verified the reliability of the structure and structural dynamics to verify by calculated natural frequencies adding the weight of the cabinet structure and the structural displacement and stress results confirmed with vibration / shock caused by the vehicle movement.

유한요소해석을 이용한 이동형 쉘터구조물의 동특성 분석에 대한 연구

손동훈(Dong-Hun Son),강광희(Kwang-Hee Kang),최지호(Ji-Ho Choi),박도훈(Do-Hoon Park),김준환(Joon-Hwan Kim) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.10

흉요추부 및 요추부의 방출성 골절에서 후방기기 정복이 척추관의 면적 변화에 미치는 영향

신동배(Dong-Bae Shin),이영규(Young-Kyu Lee),안장엽(Jang-Yeob Ahn),손동훈(Dong-Hoon Son) 대한정형외과학회 1994 대한정형외과학회지 Vol.29 No.4