고 양력 타가 선박의 조종성능에 미치는 영향에 관한 연구

김상현,김현준,전희철,윤승배,박화평,김옥석,Kim, Sang-Hyun,Kim, Hyun-Jun,Jun, Hee-Chul,Yoon, Seung-Bae,Park, Hwa-Pyeong,Gim, Ok-Sok 해양환경안전학회 2010 海洋環境安全學會誌 Vol.16 No.4

최근 선박의 좌초 및 추돌 사고로 인한 해양오염이 심각해짐에 따라 선박의 조종성능에 대한 관심이 고조되고 있는 가운데 IMO에서는 Resolution MSC.137을 채택함으로써 조종성능에 대한 국제적인 기준이 강화되었다. 선박의 조종성능을 향상시키기 위해서는 여러 가지 방법이 있으나 본 연구에서는 타의 양적 증가가 조종성능 향상에 얼마나 기여하는지를 알아보고자 한다. 조종성능 평가 방법으로 수치 시뮬레이션을 이용하였고, 대상선형은 공시선형인 Mariner Class Vessel로 하였다. 조종성능 평가 방법은 선회 시험과 지그재그 시험을 수행하였고, 고 양력 타의 적용은 수학모델에서 타와 관련된 동유체력 미계수의 값을 양력 증가에 따라 변화 시켜 조종성능의 변화를 예측하였다. 시뮬레이션 결과, 타의 양력 증가로 인해 선회성능 개선이 예상되나, 변침성능을 저해할 가능성이 있는 것을 확인하였다. Recently, a vessel's maneuvering performance is considered to be an important subject as marine pollution from the ships that stranded on a rock becomes more severe. So, IMO(International maritime organization) has adopted Resolution MSC.l37 to enhance international standards of ship's maneuverability. There's more than one way to improve ship's maneuverability. This research focused on improving ship's maneuverability by high-lift rudder. To predict the maneuverability, the numerical simulation model was used. The evaluation of maneuverability was carried out by turning test and zig-zag test. The results obtained with these simulation showed that the high-lift rudder would be effective in improving the turning ability of the ship. But it was clarified that there Has a possibility that course changing ability night become bad through an increase of rudder lift.

국외 인문사회의학 교육과정 현황

김상현,Kim, Sang Hyun 연세대학교 의과대학 2008 의학교육논단 Vol.10 No.1

Purpose: This study is purposed to analyze the curriculum on medical humanity and social science in foreign medical schools. The Main topics are classified into three parts: the characteristics of American medical humanity and social science curriculum: understanding of medical humanity and social science in medical school in USA, UK, and Australia: standard recommendations on medical ethics and professionalism in curriculum design. Methods: The literature reviews and on-line searching were conducted to collect the information and data on medical humanity and social science in foreign medical schools, 9 medical schools were selected in terms of reputations in USA, UK, and Australia. Results: First, American medical humanity and social science curriculum have changed, especially from cores to electives, from informal to formal and from subjects to interdisciplinary. In addition. teaching methods have changed into small-group discussion and teaching materials into various sources, such as essays, poetry, films and so forth. Second, most medical schools had their own unique curriculum adjusted to their academic traditions. Especially, curriculum of UK and Australia were more integrated than those of USA. Finally, it is recommended that standards of medical ethics and professionalism have to be considered in curriculum design. Conclusion: It is suggested that medical humanity and social science curriculum be designed closely connecting with clinical medicine.

밝기변화 보상을 적용한 효율적인 비디오 코딩 알고리즘

김상현,Kim Sang-Hyun 한국융합신호처리학회 2004 융합신호처리학회 논문지 (JISPS) Vol.5 No.4

This paper proposes an efficient motion compensation algorithm for video sequences with brightness variations. In the proposed algorithm, the brightness variation parameters are estimated and local motions are compensated. To detect the frame with large brightness variations, we employ the frame classification based on the cross entropy between histograms of two successive frames, which can reduce the computational redundancy. Simulation results show that the proposed method yields a higher peak signal to noise ratio (PSNR) than that of the conventional methods, with a low computational load, when the video scene contains large brightness changes. 본 논문은 밝기 변화가 심한 비디오 시퀀스에 대해 효율적인 움직임 보상 알고리즘을 제안한다. 제안한 알고리즘에서는 화면간의 밝기 변화 변수들을 추정하고 지역적인 움직임 보상을 수행한다. 밝기 변화가 심한 화면을 검출하기 위해 연속되는 두 프레임간의 히스토그램의 크로스 엔트로피를 계산하여 밝기 변화가 심한 화면을 그렇지 않은 화면과 나누어 밝기 변화가 심하지 않은 경우에 발생할 수 있는 불필요한 계산량을 줄였다. 밝기 변화가 심한 비디오 시퀀스에 대한 실험결과 제안한 알고리즘은 기존의 알고리즘에 비해 적은 계산량으로 높은 PSNR (peak signal to noise ratio) 성능을 나타내었다.

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

당뇨황반부종의 빛간섭단층촬영 분류에 따른 유리체강내 트리암시놀론과 베바시주맙의 효과 비교

김상현,박정민,Sang Hyun Kim,Jung Min Park 대한안과학회 2010 대한안과학회지 Vol.51 No.2

Purpose: To compare the effect of single intravitreal injection of triamcinolone acetonide and bevacizumab for the treatment of diabetic macular edema by optical coherence tomography (OCT) patterns. Methods: We classified diabetic macular edema by three OCT patterns: Type 1, diffuse retinal thickening; Type 2, increased retinal thickness associated with the presence of intraretinal cystoid spaces (cystoid spaces with horizontal diameter >300 μm); and Type 3, serous macular detachment. According to this classification, 84 eyes of 42 patients with bilateral diabetic macular edema by the same OCT pattern participated in this study.In each patient,one eye was treated with a single intravitreal injection of bevacizumab 1.25 mg/0.05 ml (IVBI group) and the other eye with a single intravitreal injection of 4 mg/0.1 ml triamcinolone (IVTI group). A comprehensive ophthalmic examination was performed at baseline and at one, three and six months after treatment. Main outcome measures included best corrected visual acuity (logMAR) and central macular thickness measured with OCT. Results: In Type 1, central macular thickness (CMT) reduced significantly in the IVBI group at one month.In Type 2, mean BCVA and CMT improved significantly in the IVTA group at one and three months and in the IVBI group at one month following treatment. In Type 3, CMT reduced significantly in both groups at one, three and six months.However, BCVA did not significantly increase in either group at one, three or six months after treatment. Conclusions: The effects of one single intravitreal injection of triamcinolone and bevacizumab differ by OCT patterns in bilateral diabetic macular edema patients.The correct therapeutic method, depending on OCT patterns of macular edema, should result in better improvement of visual acuity. J Korean Ophthalmol Soc 2010;51(2):210-219

동적 슬롯 할당기법을 통한 인천공항과 김포공항 수용량 효율화방안

김상현,Kim, Sang Hyun 한국항공운항학회 2017 한국항공운항학회지 Vol.25 No.3

Demand for air transportation in Korea keeps increasing, and the number of airport operations also grows as a result. The major two airports in Korea, Incheon International Airport and Gimpo International Airport, share the metropolitan airspace, which is crowd with air traffic. As air traffic increases in the metropolitan airspace, the demand for the airport operations would outnumber the capacities of these airports. However, there is a room to efficiently manage the shortage of the airport capacity due to the different distributions of operations in these airports. This study presents a dynamic slot allocation that allows exchanging slots according to the traffic demand. The dynamic allocation mitigates the airports' capacity problem but the airspace capacity itself should be increased in order to tackle the problem fundamentally.

퇴계의 「향입약조」 재구성

김상현(Kim, Sang-hyun) 대한철학회 2021 哲學硏究 Vol.157 No.-

퇴계의 「향입약조」는 율곡의 「해주일향약속」과 더불어 조선향약의 전형으로 평가받는다. 그래서 많은 연구자들이 퇴계의 향약을 연구하기 위해 『퇴계선생문집』에 수록되어 있는 「향입약조」를 분석하였다. 그런데 『퇴계선생문집』에 수록된 「향입약조」보다 퇴계의 향약 사상을 더 온전히 담고 있는 「향입약조」가 있다는 문제 제기가 등장했다. 『퇴계선생문집』본 「향입약조」에 대한 의문이 제기되자 이어서 몇몇 학자들은 『퇴계선생문집』이 간행될 때 퇴계 선생이 초안했던 「향입약조」의 조항 일부가 누락된 채 간행되었다는 주장을 제기하고 있다. 이렇듯이 『퇴계선생문집』본 「향입약조」가 퇴계의 향약 사상을 온전히 담고 있는 자료인지에 대한 논란이 일고 있다. 문제는 퇴계의 향약 사상을 온전히 담고 있는 「향입약조」가 무엇이냐에 대한 이견은 퇴계의 향약 사상이 정확히 무엇인지, 그것의 주요 특징은 무엇인지에 대한 논란을 낳을 수밖에 없다. 그런데도 학계에서는 아직도 이 문제에 대한 규명작업을 하고 있지 않다. 따라서 본 연구의 목적은 퇴계의 사상을 온전히 담고 있는 「향입약조」를 복원하는 것이다. 이와 같은 목적을 이루기 위해 우리는 다음과 같은 과정을 밟을 것이다. 먼저, 퇴계의 「향입약조」와 관련된 선행연구를 검토할 것이다. 다음으로 퇴계 향약이 조선향약의 핵심으로 자리잡는데 결정적 역할을 한 제자 김기의 향약과 퇴계의 향약과 매우 유사한 것으로 평가되는 호남의 양과동향약을 차례로 분석할 것이다. 이렇게 문헌적 탐구가 마무리되면, 마지막으로 퇴계의 사상 내부로 들어가 앞선 연구를 통해 복원한 「향입약조」조항들이 퇴계의 평소 지론과 얼마나 잘 부합하는지를 검토할 것이다. 이와 같은 연구를 통해 『퇴계선생문집』 간행시 누락되었던 벌목 3개 조항과 각 벌목의 세부 규정을 복원할 것이다. This thesis is intended to find Toegye’s Hyang-Lip-yak-jo(鄕立約條) which contains the ideas of Toegye’s Hyangyak entirely. To achieve this goal, we will take the following steps. First, we will review prior research related to Toegye’s Yang-Lip-yak-jo. Through this analysis, we will reveal that there are several types of Toegye’s Hyang-Lip-yak-jo. Next, we will analyze Kim-gi-hyangyak(金圻鄕約) which established Toegye’s Hyangyak as the core of Joseon-Hyangyak, and Yang-Gwa-dong-hyangyak(良苽洞鄕約) which is considered very similar to Toegye’s Hyangyak. When this literature research is completed, we will finally go inside the thought of Toegye and examine how well the previously restored provisions of Hyangyak fit with Toegye’s usual theory. Through this research process, we will restore three provisions of Penalty and the details of each Penalty provision, which were omitted in the publication of the TegyeseonsaengMunjib(退溪先生文集).

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.

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.

지하수 내 질산성 질소 반응-이동 모델링을 위한 부지특이적 탈질화 계수 선정 방안에 대한 고찰

김상현,정재식,이승학,Kim, Sang Hyun,Chung, Jaeshik,Lee, Seunghak 한국지하수토양환경학회 2021 지하수토양환경 Vol.26 No.6

A simple and efficient scheme is presented that attempts to implement the site-specific denitrification rate in the reactive transport modeling for the nitrate in groundwater. A series of correlation analyses were conducted using 133 datasets obtained from different nitrate-contaminated sites to find the empirical relationships between denitrification rates and various subsurface properties. Based on Pearson's correlation analysis, the soil organic carbon concentrations showed a statistically significant correlation (r = 0.75, p < 0.05) with the denitrification rates. A linear regression was performed, which could be utilized to effectively determine the site-specific denitrification rate based on the soil organic carbon concentration of a site. The proposed method is expected to effectively replace the conventional methods which either were too complicated for practical application or impose large uncertainties that might end up with unreliable results.