선박용 LED Chamber Light의 열 및 광학 특성에 관한 연구

김상현,이도엽,김우성,장낙원,Kim, Sang-Hyun,Lee, Do-Yup,Kim, Woo-Sung,Jang, Nakwon 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.1

Recently, LED is widely used in the kinds of display devices or lighting. In this paper, we fabricated LED chamber light for naval vessels to replace to conventional chamber light using incandescent lamp. The LED package of chamber light was designed with luminous intensity of 5.5 cd, color temperature of $6,000{\pm}500K$, forward voltage of 3~3.2 V and input current of 60 mA. A LED module was composed of 36 LED packages and metal PCB. The VF and luminous intensity of LED package were getting down when temperature increased. The temperature of LED chamber light was measured by changing the number of LED package and applied current for one hour when an electric current flow. The heat transfer capability have been improved by using metal PCB. The power consumption of LED chamber light reduced by 86% compared to the conventional chamber light using incandescent lamp.

인천-개성 항로 바지 수송시스템 구축에 관한 기초적 연구

김상현,이승희,이영길,유진원,Kim, Sang-Hyun,Lee, Seung-Hee,Lee, Young-Gill,Yu, Jin-Won 해양환경안전학회 2008 海洋環境安全學會誌 Vol.14 No.3

Recently, the transport quantity of goods between South and North Korea is rising rapidly by increasing of economical exchange between South and North Korea and growth of Gaeseoung industrial complex. In addition to a land transportation route, it is necessary to secure various logistics and transportation route for freight transportation between Incheon and Gaesung. In this paper, we investigated a construction of barge transportaion system between Incheon and Gaesung. The barge transportation system which has many merits such as a little initial investment and convenience of harbor loading/ unloading has been also used to transport freight widely in the EU and USA. Firstly, we investigated barge transport route, marine freight and barge fleet which consists of barge and pusher between Incheon and Gaesung. And next, we designed hull form and general arrangement of a barge and pusher based on shipping service condition, barge fleet, etc. Finally, a construction plans of barge transport system such as a operation of shipping service, berthing facilities, logistics center, intermodal transport are investigated. 최근 남북한의 경제교류 증대 및 개성공단의 발전에 따라 남북한의 물동량은 급속히 증가하고 있다. 또한 인천과 개성 사이의 물류 수송을 위하여 육상수송뿐만이 아니라 다양한 물류 수송 및 수송로의 제공이 요구되고 있다. 이 논문에서는 인천과 개성 사이의 바지 운송시스템 구축에 대하여 고찰한다. 적은 초기 투자비용, 적하역 및 접안 편이성 등과 같은 유리한 점을 가진 바지 운송시스템은 유럽 및 미국 등에서 널리 사용되고 있다. 먼저 본 논문에서는 바지 운송 항로, 해상 물동량 및 바지와 푸셔로 구성되는 바지 선단 등에 대하여 고찰한다. 그 다음에 바지 해상항로 조건 및 바지 선단 등에 기초하여 바지 및 푸셔의 선형 및 일반배치 설계를 수행한다. 마지막으로 바지 항로 운영 방안, 적하역 시설, 물류 센터 및 복합 수송 등과 같은 바지 해상항로 구축 방안에 대하여 고찰한다.

선천 백내장에서 백내장 제거술 및 일차 인공수정체 삽입술 후의 사시 발생에 영향을 주는 인자 비교

김상현,김완수,이수정,Sang Hyun Kim,Wan Soo Kim,Soo Jung Lee 대한안과학회 2011 대한안과학회지 Vol.52 No.3

Purpose: To evaluate factors associated with the development of strabismus after cataract extraction and primary intraocular lens implantation. Methods: Medical records of 80 patients who had undergone cataract extraction with primary intraocular lens implantation between 6 months and 21 years of age from March 1993 to March 2008 were reviewed. Nine patients (11 eyes) with strabismus before cataract surgery were excluded. Patients were divided into 2 groups; patients with congenital bilateral cataracts (43 patients, 86 eyes) or patients with unilateral cataracts (28 patients, 28 eyes). Data were collected on age at cataract surgery, pre and post-cataract extraction visual acuity, interocular visual acuity differences, nystagmus, operation method, and the existence of associated other ocular diseases to evaluate the association of the onset of strabismus and after cataract. Results: Factors statistically significantly associated with the development of strabismus include presence of nystagmus in bilateral cataracts and postoperative visual acuity differences > 0.3 in unilateral cataracts. A post-cataract extraction mean visual acuity ≤ 0.2 and preservation of posterior capsule were significant factors in both groups. Conclusions: Children with congenital cataracts should be monitored carefully after cataract surgery for the development of strabismus especially when they have poor postoperative visual acuity, nystagmus, large postoperative interocular visual acuity differences, or preservation of posterior capsule. J Korean Ophthalmol Soc 2011;52(3):325-331

의과대학생들의 진로선택과 진로지도

김상현,윤유상,전우택,양은배,Kim, Sang Hyun,Yoon, Yoo-sag,Jeon, Woo-Tack,Yang, Eunbae 연세대학교 의과대학 2007 의학교육논단 Vol.9 No.2

Purpose: This study analysed the intention of medical students career choice, educational programmes, and mentoring and counseling system for career planning at Yonsei medical school in Korea. Methods: The data were collected based on four separate graduation questionnaires at Yonsei medical school in the years of 2005, 2006, 2007, and 2008. The number of the survey was 130 in 2005, 130 in 2006, 153 in 2007, and that of the latest was 120 in 2008. We analysed the career intention on medical specialties and activities, and perceptions of important factors in choosing medical specialty. Results : The results which can be drawn from this study are these: firstly. students had more intention for choosing clinical medicine as university faculty than any other activities. While male students preferred to major in surgery, neurosurgery, orthopedic surgery, urology, otorhinolaryngology, female students in internal medicine, neurology, anesthesiology and pain medicine, diagnostic radiology, laboratory medicine. Secondly, students perceived that the most important factor which can influence on choosing a medical specialty was individual factor such as one's interests and concerns, values, and aptitudes. In stead, they relatively less perceived mentor and role model's effects on choosing a medical specialty compared to those of the United States of America. Third, the career planning at Yonsei medical school was evaluated well, especially educational programmes for career planning such as self assessment programme, elective(specialized) courses, and conversation with a senior programme. Conclusions: Unexpectedly, there are high demands for career planning by medical students. Therefore, we will reorganize systematic devices for career planning such as mentoring and counseling system at medical school.

Luminance Projection Model for Efficient Video Similarity Measure

김상현,Kim, Sang-Hyun The Korea Institute of Convergence Signal Processi 2009 융합신호처리학회 논문지 (JISPS) Vol.10 No.2

비디오 데이터들의 효율적 색인과 검색을 위해서는 비디오 시퀀스의 유사도 측정방법이 매우 중요한 요소이다. 본 논문은 비디오 시퀀스에 대한 효율적인 유사도 측정을 위해 휘도 성분 투사법을 제안한다. 기존의 알고리즘들이 히스토그램, 윤곽선, 움직임등과 같은 특성을 사용한 반면 본 논문에서 제안한 알고리즘은 휘도 성분을 투사하는 방법을 사용하여 비디오 유사도 특성을 효율적으로 나타낼 수 있다. 비디오 데이터의 효율적인 색인과 계산량 감소를 위해 누적된 유사도에 의해 추출된 키프레임들을 이용하여 비디오 시퀀스의 유사도를 구하고 수정된 하우스도르프 거리를 사용하여 키프레임 묶음들의 유사도를 측정하였다. 실험결과 제안한 휘도투시법을 사용한 비디오 색인 기법이 유사도 특성에서 기존의 특성을 사용한 방법에 비해 확연한 정확도 및 성능 차이를 보였다. The video similarity measure is very important factor to index and to retrieve for video data. In this paper, we propose the luminance projection model to measure the video similarity efficiently. Most algorithms for video indexing have been commonly used histograms, edges, or motion features, whereas in this paper, the proposed algorithm is employed an efficient measure using the luminance projection. To index effectively the video sequences and to decrease the computational complexity, we calculate video similarity using the key frames extracted by the cumulative measure, and compare the set of key frames using the modified Hausdorff distance. Experimental results show that the proposed luminance projection model yields the remarkable accuracy and performance than the conventional algorithm.

PL법 환경을 고려한 배전 케이블 종단부의 전기적 사고 연구

김상현,최재형,최진욱,백승명,Kim, Sang-Hyun,Choi, Jae-Hyeong,Choi, Jin-Wook,Baek, Seung-Myeong 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.2

This paper introduces experimental investigates of an accident pattern for the distributing cross linking-polyethylene(XLPE) cable terminations considering product liability(PL) law environment. The influence of defects such as thickness and length decrease of XLPE, an impurity on XLPE and the gap between stress-con of housing and semi-conductor on insulating properties of the termination have been studied. The thickness and length decrease of XLPE decrease ac breakdown strengths. Breakdown traces of XLPE that is damaged by knife displayed ellipse shape. The gap of between stress-con and semiconductor deteriorates dielectric strength of XLPE seriously.

안정적인 사물인터넷 플랫폼을 위한 MQTT 기반 데이터 수집 솔루션 관한 연구

김상현,김동휘,오형석,전현식,박현주,Kim, Sang-hyun,Kim, Dong-hwi,Oh, Hyeung-seok,Jeon, Hyun-sig,Park, Hyun-ju 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.4

ICT 기술의 발전은 인간이 생산해내는 정보뿐 아니라 일상 사물을 인터넷에 연결하여 사물의 정보와 사물이 센싱하는 환경 정보까지 공유할 수 있는 사물인터넷 시대의 도래를 촉진하고 있다. 이에 사물과 사물 간 데이터를 전송하는 많은 방법들이 제안되고 있으며 대표적으로 HTTP 프로토콜을 활용한 데이터 전송 방법이 대중적으로 사용되고 있다. 하지만 방대한 데이터들을 효과적으로 처리하기 위하여 사물 인터넷 플랫폼 시장에서는 좀 더 신속하고 안정적인 통신 프로토콜을 지향하고 있다. HTTP 프로토콜을 지원하는 시스템에서는 헤더가 데이터에 비해 상대적으로 크기에 전송 효율의 문제를 보인다. 또한 시스템 과부하의 문제점이 대두되고 있으며 기업 간 자체 사물인터넷 표준은 데이터 교환 호환성을 방해하고 있다. 이에 본 논문에서는 경량의 표준 사물인터넷 프로토콜인 MQTT와 Web Socket을 활용하여 전송 효율을 개선하고 신속하고 안정성 있는 사물인터넷 플랫폼을 위한 데이터 수집 솔루션을 제안한다. We are currently able to share not only the information from humans but also the data from connected things on the Internet. We are getting close to IoT era because of progress of Information Communication Technology. Therefore, the ways of data transfer are offered between things to things. One of typical way is the HTTP protocol. However, The field of Internet of Things platforms requires more fast and more stable communication protocol to handle massive data. The system supporting HTTP protocol, there is a problem of transmission efficiency in a relatively large header compared to data. also HTTP protocol system overload situations and the problem of data compatibility happens due to each standard of many organizations. Thus, To solve these problems, I suggest the data collection solution based on MQTT protocol for the operation of the stable IoT platforms.

대형 조선소 타 장치 설계 프로세서 비교 및 분석에 의한 표준 타 장치 설계 프로세서 제안

김상현,김현준,전희철,윤승배,Kim, Sang-Hyun,Kim, Hyun-Jun,Jun, Hee-Chul,Yoon, Seung-Bae 대한조선학회 2010 大韓造船學會 論文集 Vol.47 No.1

Recently, a very large vessel's maneuvering performance, rudder performance and rudder design's importance is considered to be an important subject. There have been few studies on the design process of rudder device before. The aim of this paper is to investigate a design process of rudder device and to propose a generalized design process of rudder device. Firstly, we investigated the rudder device design process of Korean major shipyards. And the differences of a torque calculation method, rudder section design, maneuvering performance examination method, etc were analyzed theoretically. Secondly, the design process of rudder device was divided into concept design, initial design and detail design. In concept design, a rudder area was estimated and its validity was examined. In initial design, rudder profile and design method has been selected through rudder form determination process. And principal dimension and steering gear capacity were determined. Maneuvering performance was also examined by simulation tool. In detail design, design criteria considered in rudder initial design has been investigated thoroughly. Also a rudder torque, rudder cavitation performance and rudder structure analysis were estimated. And maneuvering performance was also examined by model test. Finally, based on the results of investigation, the design process of rudder device was generalized and proposed.

기질 농도 (S₀)와 F/M 비 (S₀/X₀)가 농축 하수 슬러지 혐기성 소화에 미치는 영향

김상현,주현준,Kim, Sang-Hyoun,Ju, Hyun Jun 대한상하수도학회 2012 상하수도학회지 Vol.26 No.6

The retrofitting of a thickening unit process is widely considered in municipal wastewater treatment plants in Korea to enhance the anaerobic digestion efficiency. The authors examined the effect of feed concentration (2-34.1 g VS/L) and feed to microorganism (F/M) ratio (0.50-1.35 g VS/g VS) on anaerobic batch digestion of sewage sludge. Methane yield over 90 mL $CH_4/g$ $VS_{feed}$ was found at a feed concentration in the range of 12-26 g VS/L and a F/M ratio below 0.6 g VS/g VS. A high F/M ratio decreased methane yield and rate with oragnic acid accumulation. As sudden increase of sewage sludge concentration prior to anaerobic digestion would jeopardize the digester performance due to the rasied F/M ratio, gradual increase of the sludge feed concentration or an additional biomass retention in the digester is recommended.

이진화기반 영역분할을 이용한 3D입체영상의 밝기보정

김상현,김정엽,Kim, Sang-Hyun,Kim, Jeong-Yeop 한국정보처리학회 2011 정보처리학회논문지B Vol.18 No.5

본 논문에서는 이진화기반 영역분할을 이용한 3D입체영상의 밝기 보정방법을 제안한다. 제안된 방법은 입력된 좌우 3D입체영상 중 우 영상을 이진화를 통한 영역분할을 하고 크기가 작은 영역들은 제거한다. 다음 우 영상의 각 영역들에 대해 대응되는 좌 영상내의 영역을 상관계수(correlation coefficient)를 이용한 정합을 통해 추출한다. 영역단위의 매칭을 할 때 영역들 간의 겹침을 방지하기 위하여 모폴로지 필터로 영역경계에 인접한 일정부분을 제거한다. 그리고 좌우 영상의 영역 간 히스토그램 명세화를 수행함으로써 우 영상의 밝기 보정을 한다. 실험에서 좌 영상으로부터 블록단위 움직임보상으로 우 영상을 생성했을 때 제안한 방법이 블록평균 정합오차가 가장 작은 것을 확인 할 수 있었다. In this paper, we propose a method for intensity correction using binarization-based region segmentation in 3D stereoscopic images. In the proposed method, 3D stereoscopic right image is segmented using binarizarion. Small regions in the segmented image are eliminated. For each region in right image, a corresponding region in left image is decided through region matching using correlation coefficient. When region-based matching, in order to prevent overlap between regions, we remove a portion of the area closed to the region boundary using morphological filter. The intensity correction in left and right image can be performed through histogram specification between the corresponding regions. Simulation results show the proposed method has the smallest matching error than the conventional method when we generate the right image from the left image using block based motion compensation.