가변 시간 분해능 시간 영역 전자파 해석법

김형훈,박종일,김형동,Kim Hyung-Hoon,Park Jong-Il,Kim Hyeong-Dong 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.9

본 논문은 무조건 안정의 특징을 갖는 ADI-FDTD의 특성을 효과적으로 적용하기 위한 가변 분해능 시간 영역 전자파 해석법을 제안한다. 제안된 해석법은 관심 주파수 영역에서 정확도를 유지하면서 분해 시간 간격을 증가시켜 계산 시간을 감소시킬 수 있다. To make the best use of known characteristics of the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method such as unconditional stability and modeling accuracy, an efficient time domain solution with variable time-step size is proposed. Numerical experiment shows that a time-step size for a given mesh size can be increased preserving a desired numerical accuracy over frequencies of interest. The proposed method can be used to analyze electromagnetic problems with reduced computation time.

고속 전자파 해석을 위한 그린 함수의 이산 웨이블릿 표현법

김형훈,박종일,김형동,Kim Hyung-Hoon,Park Jong-Il,Kim Hyeong-Dong 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.9

A compact representation of Green function is proposed by applying the discrete wavelet concept in the k-domain, which can be used for the acceleration of scattered field calculations in integral equation methods. Since the representation of Green function is very compact in the joint spatio-spectral domain, it can be effectively utilized in the fast computation of radiation integral of electromagnetic problems. A mathematical expression of Green function based on the discrete wavelet concept is derived and its characteristics are discussed. 파수 영역(k-domain)에서 웨이블릿 변환 개념을 적용한 그린 함수 표현법은 적분 방정식에 활용할 때 전자파 해석의 고속화 계산에 사용할 수 있다. 그 표현 식은 기존의 표현에 비해서 매우 간결하기 때문에 전자파 해석의 방사 적분 계산 시간을 줄이는데 효과적으로 사용될 수 있다. 그린 함수의 이산 웨이블릿 개념을 이용한 수학적인 표현 식을 유도하고 그 특성에 대하여 설명하고자 한다.

배경기계학습을 사용한 침입탐지시스템

김형훈(Hyung-Hoon Kim),조정란(Jeong-Ran Cho) 한국컴퓨터정보학회 2019 韓國컴퓨터情報學會論文誌 Vol.24 No.5

The existing subtract image based intrusion detection system for CCTV digital images has a problem that it can not distinguish intruders from moving backgrounds that exist in the natural environment. In this paper, we tried to solve the problems of existing system by designing real - time intrusion detection system for CCTV digital image by combining subtract image based intrusion detection method and background learning artificial neural network technology. Our proposed system consists of three steps: subtract image based intrusion detection, background artificial neural network learning stage, and background artificial neural network evaluation stage. The final intrusion detection result is a combination of result of the subtract image based intrusion detection and the final intrusion detection result of the background artificial neural network. The step of subtract image based intrusion detection is a step of determining the occurrence of intrusion by obtaining a difference image between the background cumulative average image and the current frame image. In the background artificial neural network learning, the background is learned in a situation in which no intrusion occurs, and it is learned by dividing into a detection window unit set by the user. In the background artificial neural network evaluation, the learned background artificial neural network is used to produce background recognition or intrusion detection in the detection window unit. The proposed background learning intrusion detection system is able to detect intrusion more precisely than existing subtract image based intrusion detection system and adaptively execute machine learning on the background so that it can be operated as highly practical intrusion detection system.

인공신경망을 사용한 수화영상인식시스템

김형훈(Hyung-Hoon Kim),조정란(Jeong-Ran Cho) 한국컴퓨터정보학회 2019 韓國컴퓨터情報學會論文誌 Vol.24 No.2

Hearing impaired people are living in a voice culture area, but due to the difficulty of communicating with normal people using sign language, many people experience discomfort in daily life and social life and various disadvantages unlike their desires. Therefore, in this paper, we study a sign language translation system for communication between a normal person and a hearing impaired person using sign language and implement a prototype system for this. Previous studies on sign language translation systems for communication between normal people and hearing impaired people using sign language are classified into two types using video image system and shape input device. However, existing sign language translation systems have some problems that they do not recognize various sign language expressions of sign language users and require special devices. In this paper, we use machine learning method of artificial neural network to recognize various sign language expressions of sign language users. By using generalized smart phone and various video equipment for sign language image recognition, we intend to improve the usability of sign language translation system.

태권도 시범활동을 통한 여가만족과 신체적자아효능감 관계 분석

김형훈(Hyung Hoon Kim),이철원(Chul Won Lee) 한국여가레크리에이션학회 2010 한국여가레크리에이션학회지 Vol.34 No.2

The purpose of this study was to examine the relationship between leisure satisfaction and physical self-efficacy through Taekwondo demonstration activity. For this study, 253 University students who participate in Taekwondo demonstration activity were selected from 6 areas, Seoul, Gyeonggi, Gyeongbuk, Gyeongnam, Jeolla, and Chungcheong. Questionnaires were used as a research method. In order to analyze the result, exploratory factor analysis, reliability analysis, correlation analysis and the multiple liner regression were conducted by using SPSS13.0 version. The findings of this study are as follows; First, physiological satisfaction from the Taekwondo demonstration activity was related to perceived physical ability under the physical self efficacy. Second, physical satisfaction from the Taekwondo demonstration activity was related to the physical self-presentation confidence.

마이크로 컴퓨터를 이용한 실시간 QRS 검출 앨고리즘

金炯勳(Hyung-Hoon Kim),李景中(Kyung-Joong Lee),金成煥(Sung-Hwan Kim),李明鎬(Myung-Ho Lee) 대한전기학회 1986 전기학회논문지 Vol.35 No.4

재미 한인 태권도사범의 미국 문화적응 경험에 관한 분석

김형훈(Hyung Hoon Kim),이철원(Chul Won Lee) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.40

The objective of this study was to understand the experience of acculturation for Korean Taekwondo masters lived in United States. Based on the in-depth interview, 5 research informants were participated in this study for explaning the process of acculturation. The results were as follows; Firstly, the reason for moving to USA was classified as a challenge and an interest in American culture. Secondly, the main stress due to acculturation was inconvenience of communication and economic burden. At lastly, the major concern was related to visa issues. The result showed that despite facing hardship moment, Korean Taekwondo master understood and accepted American culture and integrated themselves into it as time goes by.

청소년 태권도 수련생의 사회적지지와 정신건강과의 관계

김형훈 ( Hyung Hoon Kim ),이철원 ( Chul Won Lee ) 대한무도학회 2010 대한무도학회지 Vol.12 No.1

본 연구의 목적은 청소년 태권도 수련생의 사회적지지와 정신건강과의 관계를 규명하는데 있다. 이를 위하여 서울·경기 소재의 고등학교에 재학 중이고, 태권도 수련 활동에 참여하는 청소년을 편의표집방법을 활용하여 350명을 표집 하였다. 조사도구는 설문지를 사용하였으며, 불성실하게 답변한 설문지 8부를 제외하고 342부의 설문지를 수거하고 결과분석에 사용하였다. 설문지를 통해 수집된 자료는 구성타당도 검증을 위한 요인분석과 신뢰도검정을 실시하였으며, 결과분석을 위해 상관관계분석과 다중회귀분석을 이용하여 분석하였다. 이상의 방법을 통해 얻어진 결과는 다음과 같다. 첫째, 청소년 태권도 수련생의 사회적지지와 정신건강은 상관관계를 가지고 있었다. 둘째, 청소년 태권도 수련생의 사회적지지가 정신건강에 통계적으로 유의한 영향을 미치는 것으로 나타났다. The purpose of this study was to examine the relationship between the Tae kwon do trainees` social support and mental health. For this study, 350 high school students who participate in Tae kwon do training activity in Seoul and Gyeonggi-do areas were selected with the convenience sampling method. The result, was analyzed with the confirmatory factor analysis for construct validity test, reliability analysis, correlation analysis and the multiple liner regression analysis. The study results are as follows: First, in the correlation of the youth trainees` social support and mental health, there was both significant and weak relationship existing between social support`s sub-factor and mental health`s sub-factor. Second, the social support had statistically significant effects on the mental health of the youth trainees.

Development of big data based Skin Care Information System SCIS for skin condition diagnosis and management

Hyung-Hoon Kim(김형훈),Jeong-Ran Cho(조정란) 한국컴퓨터정보학회 2022 韓國컴퓨터情報學會論文誌 Vol.27 No.3

피부상태의 진단과 관리는 뷰티산업종사자와 화장품산업종사자에게 그 역할을 수행함에 있어서 매우 기초적이며 중요한 기능이다. 정확한 피부상태 진단과 관리를 위해서는 고객의 피부상태와 요구사항을 잘 파악하는 것이 필요하다. 본 논문에서는 피부상태 진단 및 관리를 위해 소셜미디어의 빅데이터를 사용하여 피부상태 진단 및 관리를 지원하는 빅데이터기반 피부관리정보시스템 SCIS를 개발하였다. 개발된 시스템을 사용하여 텍스트 정보 중심의 피부상태 진단과 관리를 위한 핵심 정보를 분석하고 추출할 수 있다. 본 논문에서 개발된 피부관리정보시스템 SCIS는 빅데이터 수집단계, 텍스트전처리단계, 이미지전처리단계, 텍스트단어분석단계로 구성되어 있다. SCIS는 피부진단 및 관리에 필요한 빅데이터를 수집하고, 텍스트 정보를 대상으로 핵심단어의 단순빈도분석, 상대빈도분석, 동시출현분석, 상관성분석을 통해 핵심단어 및 주제를 추출하였다. 또한 추출된 핵심단어 및 정보를 분석하고 산포도, NetworkX, t-SNE 및 클러스터링 등의 다양한 시각화 처리를 함으로써 피부상태 진단 및 관리에 있어 이를 효율적으로 사용할 수 있도록 하였다. Diagnosis and management of skin condition is a very basic and important function in performing its role for workers in the beauty industry and cosmetics industry. For accurate skin condition diagnosis and management, it is necessary to understand the skin condition and needs of customers. In this paper, we developed SCIS, a big data-based skin care information system that supports skin condition diagnosis and management using social media big data for skin condition diagnosis and management. By using the developed system, it is possible to analyze and extract core information for skin condition diagnosis and management based on text information. The skin care information system SCIS developed in this paper consists of big data collection stage, text preprocessing stage, image preprocessing stage, and text word analysis stage. SCIS collected big data necessary for skin diagnosis and management, and extracted key words and topics from text information through simple frequency analysis, relative frequency analysis, co-occurrence analysis, and correlation analysis of key words. In addition, by analyzing the extracted key words and information and performing various visualization processes such as scatter plot, NetworkX, t-SNE, and clustering, it can be used efficiently in diagnosing and managing skin conditions.

노인의 여가활동과 우울의 관계: 여가인식의 조절효과

김형훈 ( Kim Hyung-hoon ),이지연 ( Lee Jiyeon ) 한국레저사이언스학회(구 한국여가웰니스학회) 2018 한국레저사이언스학회지 Vol.9 No.1

본 연구는 노인들의 여가활동유형과 여가인식 정신건강의 구조관계를 파악하여 노인여가와 심리적 특성에 대해 파악하는데 그 목적이 있다. 연구는 2016년 Sendex(노인 & 장애인 박람회)에 참여한 65세 이상의 노인들을 대상으로 설문을 수거하여 본 연구에 적합한 총 193부의 설문을 연구에 활용하였다. 수집된 자료는 SPSS 22.0을 사용하여 빈도분석과 상관관계 분석, AMOS를 활용하여 경로분석을 실시하였다. 연구결과 여가활동유형 중 취미문화 활동과 사회활동이 모든 정신건강의 하위요인에서 유의하게 나타났다. 정신건강과 여가인식의 관계를 확인한 결과 주관적 건강상태가 여가인식의 하위요인과 유의미한 영향을 미쳤다. The purpose of this study is to examine the relationships of leisure activity types, leisure cognitive and mental health. This study utilized random sampling on the subjects of residents in SENDEX 2016(12nd Senior & People with Disability Expo) who are over 65 years old, total 193 were used for this study. Data was analyzed by employing SPSS ver22.0 for Windows, frequency analysis, correlation analysis and AMOS. The results showed that hobby·cultural activities and social activities of leisure activitiy types havs positive effects with all sub fectors of mental health. The results of the relationship between mental health and leisure cognitive, subjective health status were correlated with all sub fectors of leisure cognitive. with this results, leisure activity types, leisure cognitive and mental health.