• 한국CDE학회논문집
• /
• 제9권1호
• /
• pp.62-76
• /
• 2004

Many customers are no longer satisfied with mass-produced goods. They are demanding customization and rapid delivery of innovative products. Many companies are now realizing that the best way to reduce life cycle costs is to evolve a more effective product development paradigm using Internet and web based technologies. Yet there remains a gap between current market demands and product development paradigms. The existing CAD systems require that product developers possess all the design analysis tools in-house making it impractical to employ all the needed and newest tools. Hence, this paper addresses how assembly operation analysis can be embedded transparently and remotely into a service-oriented collaborative assembly design environment. A new assembly operation analysis framework is introduced and a relevant architecture and tools are developed to realize the framework. Instead of the current sequential process for verifying and validating an assembly design, a new Virtual Assembly Analysis (VAA) method is introduced in the paper to predict the various effects of joining during actual collaborative design. As a case study, arc welding and riveting processes are investigated. New service-oriented VAA architecture and its VAA components are proposed and implemented on prototype mechanical assemblies.

• 한국컴퓨터그래픽스학회논문지
• /
• 제15권3호
• /
• pp.1-9
• /
• 2009

최근 역감, 촉감 피드백을 생성할 수 있고 3 차원 상호작용이 가능한 컴퓨터 인터페이스 기술이 발전하면서 기존의 입출력 장치에 의존하던 컴퓨터 시뮬레이션의 한계가 줄어들어 그 종류가 다양해지고 있다. 특히, 가상현실 기반 수술 시뮬레이터의 수요가 증가 하면서 사실적인 가상환경을 제공하는 방법에 관련된 연구가 활발히 진행 되고 있으며 그 중에서 가상 장기 모델의 사실적인 표현 기술은 사용자의 몰입감을 높여주는데 중요한 역할을 하기 때문에 반드시 필요한 분야이다. 가상 장기 모델의 사실성을 높이기 위해서는 사용자의 상호작용에 따라 변형되는 시각적 피드백과 알맞은 햅틱 피드백을 전달해야한다. 본 연구에서는 이 두 가지 피드백은 사람이 인지하는 방법과 시스템의 요구 사항이 다르기 때문에 보다 효과적인 시뮬레이션을 하기 위하여 서로 다른 두 모델을 구현하고 두 모델간의 동기화를 위한 기술로써 적응성 질량-스프링 모델 기법을 제안한다. 또한, 유연체 변형에 대하여 표면의 세부 형태를 보여주는 시각모델과 사용자의 상호작용에 따른 햅틱 피드백을 전달하는 햅틱 모델, 그리고 이 두개의 모델을 연동시키는 동기화 모델을 통하여 유연체의 거동을 실시간, 사실적으로 제공할 수 있는 가변형 모델 시뮬레이션 프레임워크를 설계한다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.1153-1159
• /
• 2007

The vibration analysis is necessary at the design stage to improve crew's life on board and to prevent the vibration troubles of the hull structures and main machineries prior to the construction. Especially, if high vibration problems occur on the global structures like the hull girder and the deckhouse after construction, it takes lots of time, labor and cost to cure them and thus accurate analysis of global vibration should be performed from the design stage. In this study, some factors for the global vibration analysis have been investigated and the way to be applied to the analysis has been suggested.

• 한국안전학회지
• /
• 제18권1호
• /
• pp.19-27
• /
• 2003

This paper presented an experimental modal analysis of clamped perforated rectangular plates submerged in water. The penetration of holes in the plates had a triangular pattern with P/D (pitch to diameter) 1.750, 2.125, 2.500, 3.000 and 3.750. The natural frequencies of the perforated plates in air were obtained by the Rayleigh-Ritz method and compared with the experimental results. Good agreement was obtained between the analytical solution and experimental result. The experimental results in water showed that the mode shapes are not sensitive to the depth of submergence. The natural frequencies were shown to decrease drastically once the perforated plates come in contact with water. However, the natural frequencies decrease with the depth of submergence until a certain depth is reached, and become the asymptotic values beyond this depth of submergence. The depth of submergence did not affect the damping ratio greatly.

• 한국소음진동공학회논문집
• /
• 제18권5호
• /
• pp.509-515
• /
• 2008

The vibration analysis is necessary at the design stage to improve crew's life on board and to prevent the vibration troubles of the hull structures and main machineries prior to the construction. Especially, if high vibration problems occur on the global structures like the hull girder and the deckhouse after construction, it takes lots of time, labor and cost to cure them and thus accurate analysis of global vibration should be performed from the design stage. In this study, some factors for the global vibration analysis have been investigated and the way to be applied to the analysis has been suggested.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2013년도 특별논문집
• /
• pp.85-89
• /
• 2013

In the engine room and the aft body, there are so many fluid tanks such as fresh water tank and oil tank. The vibration analysis for the fluid tank structures has to consider the added mass effect due to the fluid. However, it is known that the result of the fluid tank has the difference according to the boundary condition of the fluid field such as infinite fluid and finite fluid. In this paper, a numerical case study is carried out for the research about the vibration characteristics of the fluid tank with various fluid field. In addition, an experimental study is carried out to verify the validity of the vibration analysis for the fluid tank structure.

• 한국소음진동공학회논문집
• /
• 제17권1호
• /
• pp.3-9
• /
• 2007

In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(virtual mass method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
• /
• pp.19-26
• /
• 1997

Firesafety design engineerings have been mainly derived from complicated rearrangement of descriptive specifications in codes or regulations through a great number of lessons from fire disasters. In this paper, the author refers to some recent developments in the field of building fire protection. At first, the author expresses his viewpoints concerning performance-based design codes, which have been popular throughout the world as a symbol of freedom from restricted usage of building materials and components prescrived in regulation or bylaws, in spite of some conflicts between objects-oriented design method and industrial mass production. Secondly, the author introduces several innovative fire protection methods adopted for large or void spaces in building complex. Finally, the author forcasts a next development of firesafety science and technology, aimed at securing personal safety in hyperscale urban areas.

• 디자인학연구
• /
• 제16권4호
• /
• pp.5-14
• /
• 2003

본 연구는 매스커스터마이제이션을 위한 소비자 참여 디자인 과정에 디자인에 관한 비전문가인 일반 소비자들이 그들의 디자인 요구를 표현할 수 있는 도구로서 인터랙티브 디자인 툴킷(Interactive Design Toolkit)의 개발과 이의 활용 방법을 제시하고자 한다. 일반 소비자들의 디자인 요구 사항을 표현하게 하기 위해서는 그들에게 익숙하고 직접적인 의사소통 방법이 필요하며, 디자인의 결과는 디지털 매체(digital media)의 형태로 변환될 필요가 있다. 본 연구에서는 사용자의 직접적인 조작을 통해 컴퓨터를 조작함으로써 디자인의 변경 및 구현이 가능한 디자인 도구로서 인터랙티브 디자인 툴킷(Interactive design toolkit)을 정의하고자 한다. 인터랙티브 디자인 툴킷은 PC 기반의 영상인식 시스템을 응용한 것으로서, 사용자는 물리적인 모형을 이용하여 스스로 디자인 안을 만들고 영상인식시스템을 이용하여 컴퓨터 가상 공간에서 가상의 모델을 구성할 수 있다. 인터랙티브 디자인 툴킷은 유통측 커스터마이제이션에서의 소비자 참여 디자인에 활용할 수 있으며, 특히, 시스템 키친(system kitchen)과 같이 모듈(module)식으로 제작되고 조합될 수 있는 제품의 레이아웃(layout) 조합에 효율적이다. 향후에는 3차원 형상의 직접적인 형태변형을 위한 디자인 툴킷의 개발이 요구되며, 제품 디자인과 자동차 디자인 분야에 활용될 것으로 예상된다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.2005-2011
• /
• 2003

Introducing the interfacial pressure jump terms based on the surface tension into the momentum equations of two-phase two-fluid model, the system of governing equations is turned mathematically into the hyperbolic system. The eigenvalues of the equation system become always real representing the void wave and the pressure wave propagation speeds as shown in the previous manuscript. To solve the interfacial pressure jump terms with void fraction gradients implicitly, the conventional semi-implicit method should be modified as an intermediate iteration method for void fraction at fractional time step. This advanced semi-implicit method (ASIM) then becomes stable without conventional additive terms. As a consequence, including the interfacial pressure jump terms with the advanced semi-implicit method, the numerical solutions of typical two-phase problems can be more stable and sound than those calculated exclusively by using any other terms like virtual mass, or artificial viscosity.