Manta형 무인잠수정(Manta-type Unmanned Undersea Test Vehicle, 이하 MUUTV라 함)은 Naval Undersea Warfare Center의 Manta Test Vehicle의 설계 및 운용 개념을 기초로 하여 제안되었다(손 등, 2006). 본 연구에서는 Feldman(1979)과 손 등(2006)의 6자유도 운동 수학모델을 이용하여 MUUTV의 조종운동 특성에 미치는 유체력미계수의 민감도 해석을 수행하였다. 민감도 해석 기법으로는 Sen(2000)이 제안한 방법을 채택하였다. 본 연구를 통하여 각각의 유체력미계수가 MUUTV의 조종운동 특성에 미치는 영향을 정량적으로 파악할 수 있었으며, 상대적으로 영향을 작게 미치는 유체력미계수가 포함된 항을 제거하여 조종운동 수치 시뮬레이션을 수행하여도 운동 추정이 가능함을 알 수 있었다.

본 연구는 동남아 각국에서 시행되고 있는 레저 스쿠버 잠수 인증 제도에 대한 자료를 수집하고, 잠수 현황 및 인증 현황을 비교하였다. 자료 수집을 위해 인터넷에 게시된 내용을 많이 활용하였고, 관련 문헌을 조사하였으며, 자료 보완을 위해 잠수 협회 관계자, 2007년 동남아 각국의 DIVE EXPO에 참가한 동남아 각국의 관공홍보 정부 관계자, 잠수 리조트 운영자 및 강사들과 폭 넓은 인터뷰를 하였다. 논문에는 인증 제도에 대한 이해를 돕기 위해 스쿠버 인증과 국제 표준의 관계에 대해서도 언급하였다. 조사 결과, 동남아 지역은 레저 스쿠버 잠수 활동이 매우 활발한 지역으로 관광 산업에서 중요한 부분을 차지하고 있었으며, 전 세계 레저 다이버 인증 숫자의 30% 이상을 차지하고 있는 큰 시장으로 발전되어 있었다. 그러나 스쿠버 잠수 활동이 구미 지역에서 도입되었고 잠수 단체의 총 본부가 구미 지역에 있는 만큼 잠수 제도나 정책 문제에 있어서 조직 체계상 아시아에서 주도적인 역할을 하기 어려운 구조이며, 현재 상태로는 개선책을 찾기가 매우 어려울 것으로 예상된다. 또한 동남아시아에서는 유럽이나 미국과 같이 국제 표준 제도와 협력하여 교육의 질을 높이기 위한 프로그램 도입 및 단체 결성에는 아직 무관심한 것으로 나타났지만 이에 대한 필요성이 곧 대두될 것으로 예측되고 있다.

Dynamic simulator can be a helpful tool for understanding underwater robotic system's dynamics. However, due to difficulties in modeling dynamics of vehicle/manipulator and interaction between them, dynamic simulation is not easy. This is true even when fluid dynamics are not considered during the simulation. In this paper, two schemes are introduced for dynamic simulation of underwater robotic systems. One is principle of dynamical balance, which is an easy and powerful tool for formulating dynamic equations of composite systems such as underwater vehicle- manipulator system. In the dynamic modeling, this principle gives us the closed-form of dynamic equations on matrix Lie group. The other is geometric integration algorithm, called 4-th order explicit Munthe-Kaas method. By this method, the derived differential equations can be integrated preserving geometric structure. Adopting these two schemes, dynamic simulation of underwater vehicle- manipulator system can be conducted more easily and more reliably.

The thruster is the crucial factor of an underwater vehicle system, because it is the lowest layer in the control loop of the system. In this paper, we propose an accurate and practical thrust modeling for underwater vehicles which considers the effects of ambient flow velocity and angle. In this model, the axial flow velocity of the thruster, which is non-measurable, is represented by ambient flow velocity and propeller shaft velocity. Hence, contrary to previous models, the proposed model is practical since it uses only measurable states. Next, the whole thrust map is divided into three states according to the state of ambient flow and propeller shaft velocity, and one of the borders of the states is defined as Critical Advance Ratio (CAR). This classification explains the physical phenomenon of conventional experimental thrust maps. In addition, the effect of the incoming angle of ambient flow is analyzed, and Critical Incoming Angle (CIA) is also defined to describe the thrust force states. The proposed model is evaluated by comparing experimental data with numerical model simulation data, and it accurately covers overall flow conditions within 2N force error. The comparison results show that the new model's matching performance is significantly better than conventional models'.

연구는 1997년부터 2003년까지 우리나라 전국에서 발생한 스쿠버 잠수 사고 자료를 수집 및 분석하고 일본 및 미국에서 발생한 잠수 사고와 비교 분석하여 우리나라 스쿠버 잠수 사고의 특성을 밝혀내었다. 연구 결과는 잠수 사고 예방에 큰 기여를 할 수 있을 것으로 기대된다. 사고 자료는 대한수중협회의 기술위원회에 보고된 자료와 해양경찰청의 자료, 스쿠버 잠수 전문점에 전화 통화 및 방문 조사를 실시하여 얻은 정보, DAN(Diver Alert Network)에서 발행한 잠수 사고 보고 자료집, 월간 잡지에 수록된 잠수 사고 보고 자료, 그리고 세미나 발표 자료 등을 참조하였다. 자료 분석은 사망 사고에 국한하였으며 분석 결과 우리나라의 사망률이 일본의 2.8배, 미국의 2.2배 수준인 것으로 나타났다.

Today diving activity and technology are indispensable for underwater technology and offshore engineering. And then diving business is still more important to business of subsea. This study surveyed the issue of diving activity in Korea as for compared foreign diving activity. This paper analyzed the status of diving business that include commercial and sport-leisure diving business and development of commercial divers in Korea. This paper reputed the object, the necessity and the character of commercial divers. For the purpose of this study is considered in order to analyze the environment of commercial divers and propose the planning for industrial diving business. Under the present circumstance in Korea this development planning study may be restricted. but the effective planning to activate Korean commercial diving business is abstracted as follows; First, establishment of new course, grade, certificate and licence test for diver is a pre-requisite factor for the successful enactment. Second, the political assistance of concerned government authority is needed. Third, establishment of Korean diving school and medical center for divers are strongly required. Forth, setting up the department of diving activity in university.

2차의 섭동법과 경계요소법에 기초한 시간영역해석법은 불규칙파의 파동장에 있어서 파-구조물의 비선형간섭을 해석할 수 있는 해석법이지만. 파와 구조물의 운동이 정상상태에 도달하기까지 시간스텝으로 계산을 수행하여야 하므로 계산시간이 매우 길어지고, 각 성분파와 그에 의한 운동요소를 평가하는 것이 어렵다. 반면에 주파수영역해석법은 계산시간이 짧고, 각 성분요소들의 변화특성을 쉽게 판단할 수 있지만, 불규칙파동장으로의 적용이 현실적으로 어렵다는 단점을 가진다. 본 연구에서는 잠제 등에 대해서 전개되어 있는 주파수영역해석법을 임의형상의 부체 구조물에 대해 새롭게 수식의 전개를 수행하고, 압축공기주입 부체구조물에 적용하여 실험 및 이론해석결과로부터 그의 타당성을 확인한다. 이 때 압축공기의 거동은 Boyle법칙을 사용하여 평가한다.

The present paper discusses the nonlinear wave deformation due to a submerged coastal structure. Theory is based on the frequency-domain method using the third order perturbation and boundary integral method. Theoretical development to the second order perturbation and boundary integral method. Theoretical development to the second order Stokes wave for a bottom-seated submerged breakwater to the sea floor is newly expanded to the third order for a submerged coastal structure shown in Figure 1. Validity is demonstrated by comparing numerical results with the experimental ones of a rectangular air chamber structure, which has the same dimensions as that of this study. Nonlinear waves become larger and larger with wave propagation above the crown of the structure, and are transmitted to the onshore side of the structure. These characteristics are shown greatly as the increment of Ursell number on the structure. The total water profile depends largely on the phase lag among the first, second and third order component waves.

The submarine played an active part in military operation during the last of nineteenth century. Today, as an aid to science and technology and technology m the submarine is being utilized in the fields of deep sea investigation and sight-seeing as well as military activities. When the stability and the maneuverability of a submarine is studied, the problems arise on the vertical plane as well as the horizontal plane. However, the horizontal plane has been dealt with in the study of surface vessels. The author attempts to look into the hydrodynamic directional stability at high speeds (above 10knots) on the vertical plane, and to clarify the submarine's depth-rate as related to the factors that affect it : the distance from the center of buoyancy to the center of gravity, the speed of the submarine, and the position and the area ratio of hydroplane. In this study, the author considered the two groups of dimensionless derivatives of submarine. It is confirmed that the depth-rate of a submarine is decreased when the length, of BG is increased under the continuous submerging status. But the depth-rate is increased when the area ratio of hydroplane is enlarged. It is also confirmed that a submarine has only one critical speed in accordance with the shape of its hull, but unconcerned with its speeds.

Nowadays natural resources on shore have been almost exhausted all over the world and mankind is beginning searching for unexploited resources on the bed of deep-sea floor. In exploring mineral resources and etc. in the ground of sea-bed, a sumbersible craft is one of the most important tools. These days, the stage of the technique of building and operating an exploring submersible craft is almost alike that of building and operating an airplane in the first years of the nineteen-twenties. At the present time, the problems arising in building and operating a submersible craft can be divided into four parts as follows; 1. How to build a hull that can bear high pressure under deep sea level. 2. How to decide the necessary facilities to be put on it. 3. How to decide the scope of stabilities and maneuvering characteristics of it. 4. On what sea conditions, the devices of launching and recovering it should be designed on the mother-ship. In this paper treating one of the third problems the author made a mathematic formula that can be useful in deciding the scope of dynamic course stability on the vertical plane and actually calculated the onset speed of pitch instability of an exploring craft. With the above mentioned calculations the author demonstrated that the value of Zg and the speed of a submerged craft are the most important factors in decideing the scope of dynamic stability on the vertical plane.