데이타 네트워크에 있어서 경로 선택 알고리즘에 관한 연구

조정복,이재욱,임효택,고석범 東西大學校 1998 동서논문집 Vol.4 No.-

최근에 많은 기업체에서 LAN(Local Area Network)을 기반으로 하는 인터넷 환경을 구축하는 예가 종종 보고되어 지는 것을 보면 네트워크 설계분야에 많은 관심이 집중되고 있음을 알 수 있다. 본 논문에서, Star-Ring LAN상에서 HUB의 할당과 경로 선택 문제를 취급한다. Star-Ring LAN의 설계는 1)HUB들과 사용자 노드(컴퓨터)들 간의 연결, 2)HUB들 간의 경로 선택 문제로 나눌 수 있다. 여기서 제안한 수학적 모델은 HUB의 설치 비용과 각 노드에서 트래픽의 전송 지연 시간을 고려한다. 그리고 최적 해를 탐색하기 위하여 경험적 탐색방법의 하나인 유전 알고리즘(GA:Genetic Algorithm)을 설계한다. 끝으로 본 논문에서 제안된 유전 알고리즘의 성능을 검증하기 위하여 하나의 수치 예를 보인다. Recently, many people are interested in the field of network design again as we know that Intranet environment based on LAN(Local Area Network) is often implemented at many companies. In this paper, we deal with the HUB allocation and routing problem on Star-Ring LAN. The design of Star-Ring LAN is divided into two level problems: 1)connecting between HUBs and user nodes(i.e. computers), and 2) routing between HUBs. In the mathematical model which we will develope, the cost to set up HUBs, and delay time due to communication traffic at each node should be considered as the important factors. Also, we investigate GA(genetic Algorithm)as heuristic method to search the optimal solution. Lastly, we show a numerical example to demonstrate good performances of the proposed method.

유전적 알고리즘을 이용한 근거리 통신망의 위상 설계

조정복,임효택,이재욱,고석범 東西大學校 1999 동서논문집 Vol.5 No.-

최근에 많은 기업체에서 네트워크 설계 분야에 많은 관심이 집중되고 있다. 본 논문에서 Star-Ring LAN(Local Area Network)상에서 허브(HUB)의 할당과 경로 선택 문제를 취급한다. Star-Ring LAN의 설계는 1)허브들과 사용자 노드 즉, 컴퓨터들간의 연결,2)허브들간의 경로 선택 문제로 나눌 수 있다. 여기서 제안한 수학적 모델은 허브의 설치 비용과 각 노드에서 트래픽의 전송 지연 시간을 고려한다. 그리고, 최적 해를 탐색하기 위하여 경험적 탐색 방법의 하나인 유전 알고리즘(GA:Genetic Algorithm)을 설계한다. 끝으로 본 논문에서 제안된 유전 알고리즘의 성능을 검증하기 위하여 하나의 수치 예를 보인다. Recently, many people are interested in the field of network design again as we know that Intranet environment based on LAN(Local Area Network) is often implemented at many companies. In this paper, we deal with HUB allocation and routing problem on Star-Ring LAN. The design of Star-Ring LAN is divided into two level problems; 1) connecting between HUBs and user nodes(i.e,computers), and 2) routing between HUBs, and delay time due to communication traffic at each node should be considered as the important factors. Also, we investigate GA(genetic Algorithm) as heuristic method to search the optimal solution. Lastly we suow a numerical example to demonstrate good performances of tje proposed method.

실선시험기법을 이용한 다방향파중에서의 선박의 응답추정법

조효제,강일권,김종철 韓國海洋大學校 附設 海洋科學技術硏究所 1998 硏究論文集 Vol.7 No.-

In this study, the frequency transfer function of motions are predicted from the result of a full-scale seakeeping trials. Because the real sea has the characteristics of multi-directional waves, we compare the results in the one directional waves with ones in the directional waves. For calculation of the frequency transfer function in the directional waves, Takezawa's inverse estimation method was introduced and the frequency ranges were divided into three parts in order to consider following seas. The full-scale seakeeping trials was executed in the south sea of Korea using the stern trawler. Those results show that analysis method of the multi-directional waves is more reliable than that of one directional waves, and confirm the possibility of applying this method to the full-scale seakeeping trials.

곡선형 강박스거더 도로교의 단면최적화에 관한 연구

김상효,조성범,정재익 연세대학교 산업기술연구소 1996 논문집 Vol.28 No.1

The steel-box girder decks are widely adopted for middle and long-span bridges due to many advantages, when comparing with other open-section girder types, such as higher torsional rigidity, better resistance against corrosion, etc. In current design practice, the design variables of steel-box girder are selected mainly on the basis of engineer's experience and direct observation. Then the assumed sections are checked for design limit states. Therefore, the resulted design sections are doubtful in the optimum viewpoint. To achieve more rational design, systematic design procedure is required, by which the design constraints on steel-box girders are satisfied and the design variables of minimum cost are obtained. Generally both bending moments by transverse loads and torsional moments by eccentric loadings are the most important load effects in curved steel-box girder bridges. Therefore, an optimization program is developed to consider the torsional moment in addition to other load effects. The efficiency of the developed program has been verified by redesigning some sections selected from existing bridge designs. The resulting optimum sections with discrete variables are found to be cost-saving and comparable with original sections. Based on the parametric studies performed for mainly radius of curvature on curved bridge and bridge width, some essential guidelines for rational design of curved steel-box girder bridges are suggested.

體育行政에 關한 考察 : 그 範圍가 對象을 中心으로

李同宰,李鉉貞 군산대학교 1988 論文集 Vol.15 No.-

This study is investigate the scope and the object of administration in physical Education through the publications of Korea, America and Japan. The result of this study was as follows : 1.The scope and the object of administration in Physical Education to be dealt with in korea were as follows ; meaning, organization, government, civilian group, school, army, sports for all, workshop and community, management and plan of facilities, law and rule. 2.Compared to the others, those not to be dealt with in Korea were as follows : int ramural games, extramural games, personnel management, financial management, publicity activities, accident and legal responsibility, accident insurance. 3.Among three nations about administration theory of physical Education, America deal with more its theory and the others deal with more its practice. 4.Therefore, we have to be concerned with interdisciplinary approach in order to its theoretical study because its theory must connect with practice for the scientific development of the administration in physical Education.

쌍동선의 운동 및 파랑하중 해석

구자삼,조효제,이승철 한국해양대학교 해양과학기술연구소 2000 硏究論文集 Vol.9 No.1

A three-dimensional linearised potential theory is presented for the prediction of motions and dynamic structural responses of twin-hull ships travelling with forward speed in regular waves. Comparisons between theoretical and experimental results are shown for the motion responses and lateral wave loads of an ASR(anti-submarine rescue) catamaran. In general, good agreement between theory and experiment is found except for some discrepancies that are believed to be caused by neglect of forward speed effects on free surface.

초기 횡경사선박의 파랑중 전복거동에 관한 연구

김진안,조효제,진창배 부산대학교 1994 生産技術硏究所論文集 Vol.47 No.

It is an important problem to consider the mechanism of capsizing of a ship in waves in the design of ship. Especially, the inclined vessels which were caused by the cargo shift or inclining initially by the wind force etc, are easy to be capsized in comparison with the upright vessel. In this paper, we investigate the characteristics of roll motion of the inclined vessel in following seas by meas of the analysis of parametric oscillation. We derived the nonlinear equation of motion to express the roll motion of the inclined vessel and compared with behaviour of the upright vessel. It is known that capsizing phenomena of the inclined vessel which occur instantaneously in the following seas, can be explained well by the solution of the nonlinear equation. 파랑중 선박의 전복 메카니즘을 규명하는 것은 선박의 안전한 설계를 위하여 다루어져야 할 또하나의 중요한 문제이다. 특히 적하물의 이동이나 바람에 의한 경사모멘트 등에 의하여 경사된 선박의 경우에는 직립선에 비하여 전복될 위험이 많은 것으로 알려져 있다. 따라서, 본 논문에서는 파라메트릭 진동의 관점에서 추파중을 항해하는 초기 경사선의 횡요운동 특성을 조사하여, 선체의 전복 현상을 고찰한다. 위를 위하여 우선 초기 경사선에 대한 비선형 운동방정식을 유도하여 그 운동방정식의 해를 직립선에 대한 것과 서로 비교 검토하였다. 그 결과 추파중을 항해하는 초기경사선이 아주 짧은 시간에 전복하는 현상은 본 논문에서 설정한 비선형 운동방정식으로서 충분히 설명할 수 있음을 보였다.

국내 대학병원에서 정주용 Ciprofloxacin 사용의 적정성 평가

김신우,박효정,오원섭,김연숙,장현하,정숙인,정두련,이혁,염준섭,기현균,손준성,백경란,우건조,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내 병원에서의 정주 ciprofloxacin 사용의 적정성을 평가하고자 하였다. 재료 및 방법 : 2003년 9월 25일부터 8개의 대학병원에서 정주 ciprofloxacin을 받았던 290명의 연속적으로 모집한 성인환자를 대상으로 약제사용 평가(DUE)를 전향적으로 수행하였다. 이 연구에 사용된 DUE 기준은 미국병원약사회의 기준을 국내 실정에 맡게 수정하여 사용하였으며 1) 사용의 정당성에 관한 항목, 2) 사용 시 준수되거나 시행되어야 할 사항에 대한 항목, 3) 부작용에 대한 항목, 4) 치료 효과에 대한 항목으로 나누어 조사하였다. 결과 : 환자의 평균 나이는 54세였다. 33예(26.9%)에서만 약제 사용의 적정성 측면에서 기준을 만족하였고 91예(73.1%)에서는 사용이 적절하지 않았다. 정주 cipro-floxacin의 부적절한 사용의 흔한 원인은 수술 전후의 예방약 사용, 비뇨기계 처치 전의 예방적 사용, 열성 질환에 대한 경험적 사용 등의 순이었다. 사용 시 준수사항 의 측면에서는 사용 전 배양검사(73.8%)와 사용 중 배양검사(68.6%)가 낮은 수행 정도를 보였으나 그 외는 비교적 높은 적정성(82.4-100%)을 보여주었다. 정주 ciprofloxacin사용의 합병증은 드물었다. 치료 효과의 면에서 치료반응은 93.3%였다. 결론 : 약제 사용의 정당성 기준에 따른 정주 cipro-floxacin의 부적절한 사용은 연구에 포함된 대학병원에서 매우 흔하였다(73.1%). 그러므로 적절한 항생제 사용에 대한 교육과 제도적 장치가 매우 필요한 것으로 판단되었다. Background : To evaluate the appropriateness of intravenous (IV) ciprofloxacin usage in university hospitals in Korea. Materials and Methods : We prospectively evaluated the appropriateness of drug usage in 290 consecutive adult patients who received IV ciprofloxacin in eight teaching hospitals during the period from September 25, 2003 to November 15, 2003. Drug use evaluation (DUE) in this study was based on the modified standard by the American Society of Hospital Pharmacy with regard to the justification of drug use, critical and process indications, complications, and outcome measures. Results : Average age of the patients was 54 years. The use of IV ciprofloxacin was appropriate only in 33 cases (26.9%). Common reasons for inappropriate use of IV ciprofloxacin include perioperative uses or prophylactic injection before urologic procedures, and empirical therapy for febrile episodes. Most of the "critical indications" and "process indications" showed high rate of appropriateness (82.4-100%). However, the rate of taking culture and sensitivity test before (73.8%) and during ciprofloxacin use (68.6%) were low. Complications with ciprofloxacin use were rare. In 93.3% of cases, ciprofloxacin treatment was clinically effective. Conclusion : Use of intravenous ciprofloxacin is frequently inappropriate in tertiary care hospitals in Korea. Implementation of education program and antibiotic control system is critical in improving the appropriateness of antimicrobial use.

바아지식 초대형 부유 구조물의 유탄성 응답 해석

구자삼,김병현,조효제,이창호 韓國海洋大學校 附設 海洋科學技術硏究所 1998 硏究論文集 Vol.7 No.-

A barge-type structure has been recently watched since The Floating Structures Association of Japan proposed the new concept as the most suitable one of floating airports. In this paper, the method, which is based on a combination of a three-dimentional source distribution method and the wave interaction theory is applied to very large floating structure of barge-type. The calculated results show good agreement with the experimental and calculated ones by Yago and remarkable characteristics concerning the hydroelastic behavior of the very large floating structure on the effects of hydrodynamic interactions and choice of body modelling.

최적설계 기법을 적용한 1톤 운반차용 P.T.O축 및 트랜스미션 개발에 관한 기초연구

김재열,심재기,최승현,정효희,김훈조,오현중,박경섭 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Now, power tillers and cultivators which are spread among fruit tree households have usage, low application, and high accident risk. Therefore, the development of multi-purpose work vehicles is needed as an alternative for these problems. Especially, easy usage and the ability to easily change gears when driving and the development of the P.T.O for various tasks such as pruning, water lifting, pest control, application and, mowing are needed. In this research, we will develop a transmission with design on P.T.Oaxle for agricultural work vehicles including multi-purpose vehicles. We aim to develop a 4-wheel drive transmission of synchronous contact type for practical use in fruit tree households which is required to be a large-sized agricultural vehicle. Therefore, we have per performed as follows that are composed of load capacity from 500kg to 1,000kg, safety securing for passengers, and drive securing under bad conditions of the topography slope and swampy land and the rest. For this purpose, we have developed a prototype vehicle through strength analysis of transmission design. we have selected optimal design conditions (Optimal RPM and torque according to some works) on the power transmission with multi-purpose vehicle for various jobs: spraying, manure spreading, mowing, brush wood chopping. If development of the P.T.O containing variable RPM and torque is successful, the following tasks can be possible. Air pruning, air maintenance, water lift, pest control, application, mowing, spraying, and brush wood chopping are possible with this developed P.T.O. Methods and contents for research are followed. Therefore, we have achieved performance-tests through the prototype of the multi-purpose work vehicle and have improved on troubles by the analysis of results of R&D. Also, we provided solutions to problems in mass production in the future.