A study on the improvement of the accuracy of fishing vessels manoeuvrability prediction

Only a few studies related to the manoeuvring characteristics of fishing vessels have been reported, because most fishing vessels are not subject to the International Maritime Organization(IMO) manoeuvrability standards. In addition, since the construction scale is smaller than that of merchant ships, empirical formulas, rather than model tests, are use to predict the manoeuvring characteristics at the design stage due to time and budget savings. Nevertheless, because no empirical formula is developed for fishing vessels, the empirical formula developed for merchant ships is applied in its place. However, since the characteristics of hull shape parameter in particular and of fishing vessels and merchant ships are clearly different, prediction errors will occur. Therefore, in this study, the modified empirical formula was derived by including the characteristic parameters of target fishing vessels in the Kijima et al.(1990) formula to improve the accuracy in predicting the manoeuvring characteristics of the target fishing vessels. Simulating the turning-motions of the target fishing vessels using the modified empirical formula yielded an average error of 6% compared with the sea trial test of full scale ships. Hence, our results reproduce the test data more accurately than the Kijima et al.(1990) formula. In the future, the modified empirical formula derived through this study will enable a prediction of the manoeuvring characteristic of fishing vessels at the design stage and an improvement in ship safety and fishing efficiency in the narrow fishing port or in the fishing ground.1. 서 론 1 1.1 연구 배경 1 1.2 연구 동향 및 목적 4 1.3 연구 내용 및 한계 5 2. 조종운동 수학모델 10 2.1 좌표계 11 2.2 조종운동 방정식 11 2.2.1 선체에 작용하는 힘과 모멘트 15 2.2.2 프로펠러에 작용하는 힘 15 2.2.3 타에 작용하는 힘과 모멘트 17 2.3 경험식 22 2.3.1 선미 형상을 고려하지 않은 경험식 22 2.3.2 선미 형상을 고려한 경험식 26 3. 경험식의 유효성 검증 30 3.1 대상 선박 선정 30 3.2 조종 유체력 미계수 도출 31 3.3 선회운동 시뮬레이션 수행 38 3.3.1 수행 조건 38 3.3.2 수행 결과 38 3.3.3 수행 결과 분석 47 4. 보정 경험식 도출 49 4.1 대상 선박 선정 49 4.2 선형 특성 계수 확인 51 4.3 조종 유체력 미계수 분석 57 4.4 보정 경험식 도출 67 4.4.1 상관관계 그래프 68 4.4.2 경험식 도출 87 5. 보정 경험식의 유효성 검증 94 5.1 조종 유체력 미계수 도출 94 5.2 선회운동 시뮬레이션 수행 100 5.2.1 수행 조건 100 5.2.2 수행 결과 100 5.2.2 수행 결과 분석 108 5.3 간섭 계수 값에 대한 고찰 110 6. 요약 및 결론 113 참고문헌 115Docto

인유두종 바이러스 E5 단백질이 Hypoxia inducible factor 1-alpha의 매개에 의한 VEGF 발현 유도에 관한 연구

학위논문(박사)--서울대학교 대학원 :의과대학 협동과정 종양생물학전공,2007.Docto

MPI를 이용한 다중 프로세서 시뮬레이션 플랫폼 설계

학위논문(석사)--서울대학교 대학원 :전기컴퓨터공학부,2006.Maste

스핀들 베어링의 강성 특성에 관한 연구

학위논문(석사)--서울大學校 大學院 :機械設計學科,1997.Maste

Celecoxib induces apoptosis in cervical cancer cells independent of cyclooxygenase : using NF-κB and GADD153 as possible targets

Thesis (master`s)--서울대학교 대학원 :협동과정 종양생물학전공,2003.Thesis (master`s)-

(A) clinical study on cryptococcosis (12 cases)

의학과/석사[한글] Cryptococcosis는 Cryptococcous neoformanas에 의하여 발생되는 전신적 감염으로서 그 발생이 희귀 할 뿐 아니라 치료에 문제점을 가지고 있다. 저자는 1964년 1월부터 1977년 4월 까지 연세대학교 의과대학 부속 세브란스병원 소아과에 입원하였던 crytococcoi에 의한 뇌막염 또는 Cryptococcosis 환아 12예에 대하여 병상일지 및 병리조직소견을 기초 로 하여 연령별 및 성별 발생빈도, 침범된 장기별 분류, 임상증상, 치료제 및 침범장기에 따른 치료효과에 대하여 임상적 관찰을 하였다. 결과를 요약하면 다음과 같다. 1. 연령별 분포는 17개월에서 13세 사이였으며, 5세 미만이 7예로 많았다. 성별 분포는 남아에 1.4:1의 비율로 약간 많았다. 2. 임상적으로 가장 빈번히 침범된 장기는 중추신경계로 12예중 10예이었고 그 외의 장 기는 임파선, 피부(각각 3예), 간장 (2예) 및 폐(1예)이었다. 3. 입원시 임상증상의 빈도는 발열(7예), 두통(6예), 구토, 복통(각각 4예), 식욕부진, 경련, 황달(각각 2예)의 순으로 나타났다. 4. 사망한 6예중 2예는 적절한 치료를 시행하기 전에 사망하였으며, 나머지 4례는 amph otericin B의 치료에도 불구하고 사망하였다. Amphotericin B로 치료한 5예중 1예만이 치 유되었으며, 1975년 이후 5-fluorocytosine을 사용한 5예는 전예가 치유되었다. 5. 침범장기별 치료효과는 중추신경계 침범이 있으면서 뇌막자극증상이 있었던 6예중 5 예가 사망하였고 뇌막자극증상이 없이 범발성 감염으로 침범된 4례는 1예만 사망하였다. 임파선이나 피부만을 침범한 2예 모두 치유되었다. [영문] Twelve patients with cryptococcosis, which is a systemic infection caused by Cryptococcus neoformans admitted to the Pediatric department of Yonsei University College of Medicine over thirteen years were reviewed. The diagnosis was made by either the India ink preparation or culture of the cerebrospinal fluid and tissue sections and their cultures. The age distribution was from 17 months to 13 years with a sex ratio of 1.4:1 of male predominance. The signs and symptoms of crytococcosis were fever in seven patients, headache in six patients, vomiting and abdominal pain in four patients each, anorexia, convulsions and jaundice in two patients each, in that order of frequency. The organ system clinically involved most frequently was the central nervous system(10 patients). The organisms were found in other organs which were lymphnodes and skin (three patients each), liver (two patients), and lung (one patient). The usual therapy upto 1974 was the administration of amphotericin B. Of six patients who died, two died before adequate treatment, and four died despite ampohotericin B treatment. Only one patient survived with amphotericin B treatment. Since 1975, 5-fluorocytosine has been available and five patients who were admitted after 1974 were all alive and well for at least nine to 24 months after discharge. Of six patients who had meningeal signs with central nervous system involvement, five died, but only on died among four patients with dissminated infection who had no menigeal signs. With the advantage of oral administration and the fewer side effects of 5-fluorocytosine, it will probably replace amphotericin B as the treatment of choic for cryptococcosis although further trials are needed.restrictio

Suggesting tags of picture using GPS

With the development of technology, large amounts of picture contents are being produced and users can attach various tags to the picture. Among picture tags, most users consider location-specific tags important. Recently, pictures including GPS are becoming increasing common. In this paper, we propose a method that suggests tags of a picture from GPS coordinates included in the picture. But, GPS coordinates are not intuitive to users and difficult to be used in keyword searches. It is necessary to transform to more informative and user-friendly landmark name using reverse geocoding. When a subject is far from where the picture is taken, the difference may raise the problem of matching the subject and the actual location indicated by GPS. The proposed method solves the problem and recommends candidate tags of pictures searched in picture database around GPS coordinates. Our experimental results showed that the proposed method suggested suitable tag recommendations

외곽선기반 영상처리, 벡터화 및 고리구조 인식을 통한 선도면의 자동입력

학위논문(박사) - 한국과학기술원 : 전산학과, 1993.2, [ v, 106 p. ]Automatic input of paper-based line drawings into a CAD system can be performed by converting the rasterized image of the drawing into a description in terms of CAD primitives. The conversion process can be roughly divided into two functional modules of low-level picture processing and application specific meaning extraction. The automatic input system should be accurate, robust, and efficient. Most of existing systems impose severe restrictions on the input drawings to increase their recognition accuracy, but it prevents them from being totally effective in the general engineering environment. In addition, little care has been taken about the computational efficiency. In this thesis, we present two automatic systems for the recognition of logic circuit diagrams and the vectorization of general line drawings. By constructing the preprocessing module which is commonly used for the two systems as a sequence of contour-based picture processing operations, we can make them highly efficient. Through and error correcting mechanism and a flexible knowledge representation, we can make them reliable for the syntactic variations of input drawings. In case of vectorization, we can obtain higher degrees of data compaction ratio and applicability from the extraction of free-form curves. Experiment with a number of logic diagrams shows that the recognition system identifies more than 96＼% of symbols and connections and that an A4-sized diagram with an average complexity can be processed within 15 seconds on a workstation. Another advantage of the system is the flexibility of knowledge representation in which the prior knowledge about input diagrams can be modified without rewriting the recognition program. Similar performance can also be obtained for the vectorization system. The efficiency in terms of time and storage can be readily achieved by the contour-based picture processing, and higher degrees of geometric accuracy and data compression can be reached from the v...한국과학기술원 : 전산학과