반잠수식 부체군의 상호간섭특성

구자삼 ( Ja Sam Goo ),홍봉기 ( Bong Ki Hong ) 한국어업기술학회 1992 수산해양기술연구 Vol.28 No.1

인장 계류식 해양구조물의 동적응답 해석법의 개발

구자삼(Ja-Sam Goo),이창호(Chang-Ho Lee),홍봉기(Bong-Ki Hong) 한국해양공학회 1993 韓國海洋工學會誌 Vol.7 No.1

A numerical procedure is described for predicting the motion and structural responses of tension leg platforms (TLPs) in waves. The developed numerical approach is based on combination of a three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLPs is assumed flexible instead of the rigid body assumption used in usual two-step analysis method, proposed by Yoshida et. al. The hydrodynamic interactions among TLP members, such as columns and pontoons, are included in the motion and structural analyses. Numerical results are compared with the experimental and numerical ones, which are obtained in the literature, of the motion and structural responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

해양공간이용구조물의 응답제어

구자삼(Ja-Sam Goo),홍봉기(Bong-Ki Hong) 한국해양공학회 1991 韓國海洋工學會誌 Vol.5 No.2

A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large number of the floating bodies in waves.<br/> The hydrodynamic interactins among total floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicable to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.

쌍동선의 운동 및 파랑하중 해석

구자삼(Ja-Sam Goo),조효제(Hyo-Jae Jo),이승철(Seung-Chul Lee) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.4

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.

반잠수식 초대형 해양구조물의 파랑중 탄성응답특성

구자삼(Ja-Sam Goo),김경태(Kyung-Tae Kim),홍봉기(Bong-Ki Hong) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.4

To design a very large floating structure, such as a floating airport, we have to estimate the hydroelastic responses of a very large floating structure (VLFS) exactly. We developed the numerical method for estimating the hydroelastic responses of the VLFS. The developed numerical approach is based on a combination of the three-dimensional source distribution method, the wave interaction theory and the finite element method for structurally treating the space frame elements. The Numerical results of the hydroelastic responses and steady drift forces of a semisubmersible type offshore structure, which is supported by the 33(3 by 11) floating bodies, with various bending rigidities are illustrated.

주파수 의존형 LQR 설계법에 의한 무어링 윈치 제어시스템 설계

구자삼(Ja-Sam Goo),김영복(Young-Bok Kim) 한국항해항만학회 2014 한국항해항만학회지 Vol.38 No.1

본 논문에서는 무어링윈치시스템 제어를 위한 제어계 설계법에 대해 고찰하고 있다. 특히 무어링윈치의 동적운전이 로우프에 부가하는 급격한 부하변동을 억제함으로써 로우프 피로하중을 감소시키고 선박운동제어에 있어서의 바람직한 제어성능을 달성할 수 있도록 하는 제어기 설계법을 제안하고 있다. 최적제어이론에 기반하여, 평가함수에 주어지는 중량행렬(weighting matrix)에 주파수 특성을 부여함으로써, 고주파 모드가 포함된 제어입력이 불안전한 특성을 여기시키지 않도록 하는 것이 제어기 설계 목표이며, 이것은 곧 로우프에 급격한 부하변동을 발생시키지 않게 되는 결과를 얻게 된다. 설계된 제어기는 저차이면서도 외란에 대한 강인성 뿐 만 아니라 제어성능 또한 보장하는 유용한 기법이며 시뮬레이션 및 실험을 통해 그 유효성을 검증하고 있다. In this paper, the author consider control system design problem of the surface vessel where any types of floating units are included. To keep their motion/position, the Dynamic Positioning System(DPS) is equipped in. Even though sometimes the thrust systems are installed on them, in general the mooring winch system with the rope/wire is used. Therefore, in this paper we consider a single type mooring winch control problem to keep the vessel's position. For this, we introduce an easy and useful control approach which is based on LQ control theory. In this approach, we introduce the frequency dependent weighting matrices which give the system filters to shape frequency characteristics of the controlled system and guarantee the control performance. Based on this, we will show that the proposed approach works well.

인장계류식 해양구조물의 동적응답해석(Ⅱ)

구자삼(Ja-Sam Goo),박찬후(Chan-Hu Park),이창호(Chang-Ho Lee) 한국해양공학회 1996 韓國海洋工學會誌 Vol.10 No.1

A numerical procedure is described for predicting the motion and structural responses of tension leg platforms(TLPs) in waves. The developed numerical approach is based on a combination of a three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLPs is assumed to be flexible instead of rigid. Restoring forces by hydrostatic pressure on the submerged surface of a TLP have been accurately calculated by excluding the assumption of the slender body theory. The hydrodynamic interactions among TLP members, such as columns and pontoons, and the structural damping are included in the motion and structural analysis. The equations of motion of a whole structure are formulated using element-fixed coordinate systems which have the orgin at the nodes of the each hull element and move parallel to a space-fixed coordinate system.<br/> Numerical results are compared with the experimental and numerical ones, which are obtained in the literature, concerning the motion and structural responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

부유식 해양도시의 동적응답특성

구자삼(Ja-Sam Goo),홍석원(Seok-Won Hong) 한국해양공학회 1994 韓國海洋工學會誌 Vol.8 No.2

The dynamic response characteristics of a floating ocean city are examined for presenting the basic data for the design of huge offshore structures supported by a large number of floating bodies in waves. The numerical approach which is accurate in linear system is based on combination of a three dimensional source distribution method, wave interaction theory and the finite element method of using the space frame element. The hydrodynamic interactions among the floating bodies are taken into account in their exact form within the context of linear potential theory in the motion and structural analysis. The method is applicable to an arbitrary number of three dimensional bodies having any individual body geometries and geometrical arrangement with the restriction that the circumscribed. bottom-mounted, imaginary vertical cylinder for each body does not contain any part of the other body. The validity of this procedure was verified by comparing with experimental results obtained in the literature.

인장계류식 해양구조물의 동적응답해석 (Ⅰ)

구자삼(Ja-Sam Goo),김진하(Jin-Ha Kim),이창호(Chang-Ho Lee) 한국해양공학회 1995 韓國海洋工學會誌 Vol.9 No.1

A numerical procedure is described for predicting the motion and structural responses of tension leg platforms(TLPs) in waves. The developed numerical approach is based on a combination of a three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLPs is assumed flexible instead of the rigid body assumption used in two-step analysis method. Both the hydrodynamic interactions among TLP members, such as columns and pontoons, and the structural damping are included in the motion and structural analyses. The equations of motion of a whole structure are formulated using element-fixed coordinate systems which have the origin at the node of the each hull element and move parallel to a space-fixed coordinate system. Numerical results are compared with the experimental and numerical ones, which are obtained in the literature, concerning the motion and structural responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

바아지식 초대형 부유 구조물의 유탄성 응답 해석

구자삼(Ja-Sam Goo),조효제(Hyo-Jae Jo),김병현(Byung-Hyun Kim),이창호(Chang-Ho Lee) 한국해양공학회 1998 韓國海洋工學會誌 Vol.12 No.2

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