움직임 벡터 및 보상 블록의 특성을 이용한 움직임 보상된 차영상 CVQ

최정현,이경환,이법기,정원식,김경규,김덕규,Choi, Jung-Hyun,Lee, Kyeong-Hwan,Lee, Bub-Ki,Cheong, Won-Sik,Kim, Kyoung-Kyoo,Kim, Duk-Gyoo 대한전자공학회 2000 電子工學會論文誌-SP (Signal processing) Vol.37 No.2

본 논문에서는, 움직임 벡터와 보상 블록을 이용한 분류기를 제안하고, 이 분류기로써 MCD(motion compensated difference) 블록을 CVQ(classified vector quantization)하는 새로운 MCDI(motion compensated difference image) 부호화 방법을 제안하였다. MCD 블록의 분산은 움직임 벡터의 크기뿐만 아니라 보상 블록의 분산과도 밀접한 관계가 있으므로, 이 특성들을 이용하여, 새로운 분류기를 제안하였다. 제안한 방법은 서브 코드북(sub-codebook)을 선택하는 분류기에 대한 부가 정보가 필요 없으면서, 모의 실험 결과 분류 비트가 필요한 기존의 방법에 비해 제안한 방법이 좋은 성능을 나타내었다. In this paper, we presents a new MCDI(motion compensated difference image) coding method using CVQ(classifled vector quantization) whoes MCD(motion compensated difference) block is classified by proposed classifier using motion vector and compensated block The variance of MCD block is closely related with the magnitude of motion vector as well as the variance of compensated block, so using this property, we propose a new classifier. This scheme has no side information of the classifier what sub-codebook is selected, and simulation results show that the proposed method exhibits a good performance even when compared with a conventional method that requires classification bits.

전달함수를 이용한 동흡진기 설계에 대한 연구(I)

최정현,임병덕,Choi, Joung-Hyun,Lim, Byoung-Duk 대한기계학회 2003 大韓機械學會論文集A Vol.27 No.9

The problem of reducing the level of vibrations in structures arises in various branches of technology. For the calculation of systems equipped with DVAs, the frequencies of the protected system's free vibrations are determined first. In most practical problems system have to be considered continuous systems. It is important to obtain the detailed information about not the first frequency and the mode but anothers corresponding to it. So, this paper describes the method to obtain the accurate information about the combined discrete system. This information is obtained from the combined system's receptance. This paper shows the convenience when design the dynamic vibration absorber with the combined system's receptance.

Sendust를 이용한 휴대전화용 전파 흡수체의 개발

최정현,김동일,송재만,정재현,Choi Jung-Hyun,Kim Dong-Il,Song Jae-Man,Jung Jae-Hyun 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.8

본 논문에서는 시편의 두께와 $Al_2O_3$ 함유량, 분쇄시간에 따른 입자 크기가 Sendust를 이용한 sheet형 전파 흡수체 의 전파 흡수능에 미치는 영향을 조사한 것이다. $Al_2O_3$를 코팅한 전파 흡수체는 코팅하지 않은 전파 흡수체와 비교할 때 흡수 대역이 넓어지고, 분쇄 시간이 증가함에 따라 입자 크기가 작아지고 이로 인해 전파 흡수능이 증가함을 확인하였다. 제작된 전파 흡수체의 두께가 4 mm일 때 946 MHz에서 17.4 dB, 1 mm일 때 1.8 GHz에서 약 5 dB의 전파 흡수능을 나타내었다. In this paper, we fabricated sheet-type EM wave absorbers for mobile phones by using sendusts and tested EM wave absorption of it. The band-width of EM wave absorbers coated with $Al_2O_3$ were larger than non-coated EM wave absorbers. Particle size decreased with increasing milling time, which made the result of increasing of EM wave absorption. The fabricated EM wave absorbers show a reflection coefficient 17.4 dB at 946 MHz for a 4 mm sample and 5 dB at 1.8 GHz for a 1 mm sample.

대퇴네갈래근에 테이핑요법 적용이 근력과 근피로에 미치는 영향

최정현,이재갑,안호정,Choi, Jung-Hyun,Lee, Jae-Kap,Ahn, Ho-Jung 대한물리치료과학회 2008 대한물리치료과학회지 Vol.15 No.4

Background: This study examines the changes in muscular strength and muscle fatigue substances when taping treatment is applied in squat exercise and treadmill exercise, in which quadriceps femoris muscles are used frequently so as to clarify the effects of taping as an aid of exercise ability improvement. Methods: 20 healthy male adults in their 20's participated in the study, in which tapes were put on their quadriceps femoris muscles, and various variables as the indicator of muscular strength and muscle fatigue substances were measured by means of the measuring tool before and after exercises. Results: the following conclusion was drawn up: 1. In exercise using muscular strength of the right knee extension, the reduction of muscular strength after exercise of the taping group showed significant statistical difference from that of the non-taping group. 2. In exercise using muscular strength of the lower limbs, the reduction of blood Glaucos after exercise of the taping group showed significant statistical difference from that of the non-taping group. 3. In exercise using muscular strength of the lower limbs, the value of lactic acid after exercise of the taping group showed significant statistical difference from that of the non-taping group. Conclusion: Therefore, the results of this study demonstrate that the application of taping treatment in sports activity or daily life where quadriceps femoris muscles are used a lot can have positive effects on the improvement of muscular strength and relief of muscle fatigue.

생태저류지 LID 시설의 강우유출수 처리비 산정

최정현,이옥정,김상단,Choi, Jeonghyeon,Lee, Okjeong,Kim, Sangdan 한국물환경학회 2017 한국물환경학회지 Vol.33 No.5

Because of the rapid progress of urbanization in recent decades, the proportion of impervious areas in cities has increased. As a result, hydrological properties of urban streams have changed and non-point pollution sources have increased, that have had considerable influence on human life and ecosystems. To manage these situations, application of non-point pollution reduction facilities and LID facilities are expanding recently. In this study, it is investigated if rainfall interception rate used in design of non-point pollution reduction facilities can be applied to design of LID facilities. For this purpose, EPA SWMM is constructed for part of Noksan National Industrial Complex area wherein long-term observed storm water data can be obtained and storm water interception rates for various design capacities of a bio-retention LID facility reservoirs are estimated. While sensitivity of storm water interception rate according to design specifications of bio-retention facility is not large, sensitivity of storm water interception rate according to regional rainfall characteristics is relatively large. As a result of comparing present rainfall interception rate estimation method with the one proposed in this study, the present method is highly likely to overestimate performance of the bio-retention facility. Finally, a new storm water interception rate formula for bio-retention LID facility is proposed.

공사중단 방치건축물 정비 제도개선을 위한 실증연구: 충청남도를 중심으로

최정현,임준홍,Choi, Jeonghyeon,Im, Junhong 한국토지주택공사 토지주택연구원 2021 LHI journal of land, housing, and urban affairs Vol.12 No.1

우리나라는 경제성장과 위기, 사업성 부족 등 다양한 이유로 공사중단 방치건축물이 꾸준히 발생하고 있다. 공사중단 방치건축물은 다양한 형태와 규모로 분포하고 있으며 이로 인해 도시경관을 악화, 주거안정성을 저해하고, 화재 ·범죄·악취 등 다양한 도시문제를 야기하고 있다. 정부는 관련법을 제정·시행하고 있지만 시행과정에서 현실과 거리 있는 많은 문제점이 나타나고 있다. 이에, 본 연구는 충청남도 방치건축물을 대상으로 현지 실태조사, 건축관계인 및 이해관계인 심층인터뷰, 정비사업 시행자(LH), 도 및 시군 담당공무원 FGI를 통해 방치건축물 정비사업 추진의 문제점과 개선사항을 실증적으로 도출하였다. 그리고 이를 바탕으로 향후 방치건축물의 예방, 원활한 정비사업 추진을 위한 과제와 실효성 높은 제도개선사항을 제시하였다. South Korea is renowned as one of the countries which have experienced high economic growth in the past years. However since Global Financial Crisis in 2008, its economic growth has remained slow and majority cities have faced various issues in property sector such as declining property price, the increase of uncompleted building sites, abandoned land and disproportionate rate of vacant buildings. These abandoned sites in various scales and locations, particularly nearby residential areas have negative impacts on the urban environment such as crime and vandalism. To tackle these issue, in May 2013, the "Special Act on the Maintenance of Long-Term abandoned Buildings" was enacted and has been put into operation since May 2014. Subsequently, a base maintenance plan was established in 2016 by the Ministry of Land, Infrastructure and Transport. Nevertheless the plan has not been implemented properly due to the limitation of financial and human resources, lack of expertise and ambiguity of laws and guidelines. This study examines the challenges and barriers of the implementation of the Act and recommendations to resolve the urban issues are drawn. This study is a case study of Chungcheongnam-do and the main methods used are in-depth interviews and field surveys with a wide range of stakeholders including the main developer (LH), architects, surveyor and local authority officers. The findings suggest several improvement in the 'Special Act on the maintenance of long-term abandoned buildings'.

분포질량 동흡진기가 부착된 연속체 시스템에 대한 연구 (II)

최정현,임병덕,Choi, Jeung-Hyun,Lim, Byoung-Duk 대한기계학회 2004 大韓機械學會論文集A Vol.28 No.3

Large machine and structure can not be normally treated as lumped parameter system. Such machine or structure must be broken down to individual beams or panels the motion of which must be analysed before an absorber system can be designed for each element. The absorber may be a lumped parameter system or a continuous system. One of the most common elements in a machine or structure is the cantilever, and in this paper is considered the design of a continuous parameter absorber to reduce the transverse vibrations of a beam. So this paper describes the method to obtain the accurate information about combined continuous beam system with DVA. This information is obtained from the combined system's receptance. and this paper shows the convenience and useful informations when design the dynamic vibration absorber with the combined system's receptance.

정적분 기호 이해의 특징과 교수학적 전략

최정현,Choi, Jeong-Hyun 한국수학사학회 2011 Journal for history of mathematics Vol.24 No.3

This study aims to provide a teaching strategy accommodating the symbols of the definite integral and guiding students through the meaning of notations in area and volume calculations, based on characterization as to how students comprehend the symbols used in the Riemann sum formula and the definite integral, and their interrelationship. A survey was conducted on 70 high school students regarding the historical background of integral symbols and the textbook contents designated for the definite integral. In the following analysis, the comprehension was qualified by 5 levels; students in higher levels of comprehension demonstrated closer relation to the history of integral notations. A teaching strategy was developed accordingly, which suggested more desirable student understanding on the concept of definite integral symbols in area and volume calculations. 본 연구에서는 리만합의 극한식과 정적분 기호 각각의 구성 요소의 의미와 상호 관계에 대한 학생들의 이해의 특징을 살펴보고, 이를 토대로 하여 정적분 기호 지도에 대한 교수학적 전략을 제안함으로써 학생들이 넓이, 부피를 나타내는 정적분 기호에 대한 올바른 심상을 형성할 수 있도록 하고자 한다. 이를 위하여 정적분 기호 탄생의 수학사적 배경과 교과서의 정적분 단원의 진술 내용을 살펴보았으며, 이를 토대로 고등학교 학생 70명을 대상으로 한 설문 조사를 분석하였다. 이 연구에서 학생들의 정적분 기호에 대한 이해의 층위를 5단계로 구분할 수 있었으며, 상위 단계일수록 학생들의 기호에 대한 심상이 정적분 기호 탄생의 역사와 관련 깊음을 알 수 있었다. 이러한 분석을 바탕으로 하여 정적분 기호 지도에 대한 교수학적 전략을 제안하였으며, 그 결과 학생들이 넓이, 부피를 구하는 정적분 기호들에 대한 올바른 심상을 형성할 수 있음을 알 수 있었다.

청소년의 인지능력 훈련을 위한 운동-학습 시스템의 개발

최정현,박준호,윤지숙,서재용,박찬홍,Choi, Jung-Hyeon,Park, Jun-Ho,Yoon, Ji-Sook,Seo, Jae-Yong,Pakr, Chan-Hong 한국융합신호처리학회 2020 융합신호처리학회 논문지 (JISPS) Vol.21 No.3

With the importance of creative learning highly valued, the demand for education in early childhood and adolescence has been increasing in recent years, but simple memorization-oriented and classical teaching methods tend not to prove high effectiveness in terms of learner-centeredness. Students who study static at their desks for a long time do not prefer boring classical learning methods, and there is also a lack of educational methods and educational content that conforms to the convergence education trend in the actual educational field. Therefore, this study has created a system that allows students to exercise and learn at the same time through a fun and familiar approach, and implement educational content through activation of brain plasticity. 최근 교육현장 및 가정에서는 창의적 학습의 중요성이 높게 평가되면서 유아 및 청소년기 아동의 교육 수요가 증가하고 있지만, 단순한 암기교육 위주와 고전적인 교육방식은 학습자 중심적 측면에서 효과가 크지 않은 경우가 많다. 오랫동안 책상에 앉아 있는 학생들은 지루한 고전적인 학습방법을 선호하지 않으며, 현재 교육 현장에서도 융합 교육 트렌드에 부응하는 교육 방법 및 교육 콘텐츠가 부족한 것이 현실이다. 따라서 본 연구에서는 학생들이 재미있고 친숙한 접근방법을 통해 운동을 병행하며 학습할 수 있으며, 뇌 가소성(brain plasticity) 활성화를 통해 교육 콘텐츠를 구현할 수 있는 시스템을 만들었다.

움직임 벡터의 통계적 특성을 이용한 고속 움직임 추정

최정현,박대규,이경환,이법기,김덕규,Choi, Jung-Hyun,Park, Dae-Gyue,Lee, Kyeong-Hwan,Lee, Bub-Ki,Kim, Duk-Gyoo 대한전자공학회 2000 電子工學會論文誌-SP (Signal processing) Vol.37 No.2

고속 움직임 추정 방법들에서는, 움직임 추정 오차는 최적 탐색점에서 멀어질수록 단조 증가한다는 성질을 이용하여, 계산량을 줄인다 본 논문에서는 먼저, 참조 탐색점들의 MAE (mean absolute error) 차가 클 때에, 대부분의 움직임 벡터는 작은 MAE의 참조 탐색점 방향에서 나타난다는 통계적 특성을 조사하였다 그러므로, 이 특성을 이용하여 탐색점 수를 줄일 수 있는 고속 움직임 추정 방법을 제안한다 모의 실험 결과, 기존의 고속 움직임 추정 방법들에 비해서는 비슷한 성능을 유지하면서 계산량을 줄일 수 있었다. In Fast motion estimaion algorithms, they reduce the computational complexity using the assumption that the matching error increases monotonically as the search moves away from the global minimum error In this paper, we first investigate the statistical characteristics of motion vector that the motion vector mostly occures on the side of small MAE (mean absolute error) between the reference search points when the MAE difference of them is large Therefore, we propose a fast motion estimation algorithm using this property and can reduce the number of search points The computer simulation result shows that the proposed method reduces computational complexity compared with conventional fast algorithms.