• Korean Journal of Computational Design and Engineering
• /
• v.9 no.1
• /
• 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.

• Journal of the Korea Computer Graphics Society
• /
• v.15 no.3
• /
• pp.1-9
• /
• 2009

Traditional computer simulation uses only traditional input and output devices. With the recent emergence of haptic techniques, which can give users kinetic and tactile feedback, the field of computer simulation is diversifying. In particular, as the virtual-reality-based surgical simulation has been recognized as an effective training tool in medical education, the practical virtual simulation of surgery becomes a stimulating new research area. The surgical simulation framework should represent the realistic properties of human organ for the high immersion of a user interaction with a virtual object. The framework should make proper both haptic and visual feedback for high immersed virtual environment. However, one model may not be suitable to simulate both haptic and visual feedback because the perceptive channels of two feedbacks are different from each other and the system requirements are also different. Therefore, we separated two models to simulate haptic and visual feedback independently but at the same time. We propose an adaptive mass-spring method as a multi-modal simulation technique to synchronize those two separated models and present a framework for a dual model of simulation that can realistically simulate the behavior of the soft, pliable human body, along with haptic feedback from the user's interaction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• 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.

• Journal of the Korean Society of Safety
• /
• v.18 no.1
• /
• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.5
• /
• 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.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2013.12a
• /
• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.1 s.118
• /
• 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.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1997.11a
• /
• 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.

• Archives of design research
• /
• v.16 no.4
• /
• pp.5-14
• /
• 2003

This study suggest the development and application of the Interactive Design Toolkit as a participatory design method for general customer who are non-expert on design activity to participate in design process of mass customization. In order to let general customers to express their design needs, we have to make a familiar and direct communication method for them. And, customer's design needs should be transformed into digital media. This study define the Interactive Design Toolkit as a design tool for customer participation by direct manipulation of computer system for simulation of design needs by customer themselves. The Interactive Design Toolkit is based on a PC-based image perception system and its application. User can make virtual models in virtual space by manipulating physical objects in real world. And, The toolkit can be used in the field of participatory design for deliverer side customization, especially in system kitchen which is manufactured and distributed in modular system. More improved design toolkit for manipulating 3 dimensional shape is needed for consumer product design and car styling.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• 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.