• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.119-131
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• 1997

Ball type automatic balancer is used to reduce the vibration caused by unbalance of rotor. In this study, A analytic modeling of a front loaded washing machine with ball type automatic balancer has been suggested theoretically and ADAMS has been used to analyze the dynamic characteristics of automatic balancer. It is found from simulation and experimental results that the automatic balancer suppress the steady state vibration of the washing machine effectively. The test results match well with the simulation results of ADAMS, thereby the dynamic model of ADAMS can be used as virtual prototype to predict the vibration characteristics which could be changed by the modification of design variable and can reduce the design cycle sharply. To maximize the balancing effect of automatic balancer, the friction between balls and race and the deviation between geometric center and rotation center of drum need to be minimized and the optimum design for the stiffness of flange shaft and the angular acceleration of drum should be achieved.

• Korean Journal of Computational Design and Engineering
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• v.9 no.2
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• pp.167-174
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• 2004

As the networks connect the world, enterprises tend to move manufacturing activities into virtual spaces. Since different applications use different data terminology, it becomes a problem to interoperate, interchange, and manage electronic data among different systems. According to RTI, approximately one billion dollar has been being spent yearly for product data exchange and interoperability. As commercial CAD systems have brought in the concept of design feature for the sake of interoperability, terminologies of design feature need to be harmonized. In order to define design feature terminology for integration, knowledge about feature definitions of different CAD systems should be considered. STEP (Standard for the Exchange of Product model data) have attempted to solve this problem, but it defines only syntactic data representation so that semantic data integration is unattainable. In this paper, we utilize the ontology concept to build a data model of design feature which can be a semantic standard of feature definitions of CAD systems. Using feature ontology, we implement an integrated virtual database and a simple system which searches and edits design features in a semantic way. This paper proposes a methodology for integrating modeling features of CAD systems.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.57-74
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• 2013

In this study, the virtual fixed point analysis and 3D full-modeling analysis for pile bent structures are conducted by considering various influencing factors and the applicability of the virtual fixed point theory is discussed. Also, a discrete analysis calculating separately both the superstructure and substructure of pile bent structures is performed on the basis of an equivalent base spring model by taking into account the major influencing parameters such as soil conditions, combined loading and pile diameter. The results show that the settlement and lateral deflection of the virtual fixed point theory are smaller than those of 3D full-modeling analysis. On the other hand, the virtual fixed point analysis overestimates the axial force and bending moment compared with 3D full-modeling analysis. It is shown that the virtual fixed point analysis cannot adequately predict the real behavior of pile bent structures. It is also found that discrete analysis gives similar results of lateral deflection and bending moment to those of unified analysis. Based on this study, it is found that discrete analysis considering column-pile interaction conditions is capable of predicting reasonably well the behavior of pile bent structures. It can be effectively used to perform a more economical design of pile bent structures.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.110-114
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• 2007

In this paper we present 3-D Navigation View, a three-dimensional visualization of indoor environment which serves as an intuitive and unified user interface for our developed indoor location tracking system via Virtual Reality Modeling Language (VRML) in web environment. The extracted user's spatial information from indoor location tracking system was further processed to facilitate the location indication in virtual 3-D indoor environment based on his location in physical world. External Authoring Interface (EAI) provided by VRML enables the integration of interactive 3-D graphics into web and direct communication with the encapsulated Java applet to update position and viewpoint of user periodically in 3-D indoor environment. As any web browser with VRML viewer plug-in is able to run the platform independent 3-D Navigation View, specialized and expensive hardware or software can be disregarded.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.509-513
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• 1996

The information technology of computers and computer tools have become so powerful that virtual enterprises are not just concepts any longer The virtual enterprises comprise distributed facilities and it is necessary to have a collaborative system among them. This paper proposes the modeling process of web-based collaborative system in the distributed manufacturing environment. It also presents the information infrastructure in order to communicate and to share the information more efficiently among the collaboration subsystem. The web-based collaborative system consists of four processes: 1) product design, 2) procurement of DB information, 3) query process, and 4) negotiation. The proposed web-based collaborative system will be implemented with network technologies.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.172-179
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• 1998

To quickly determine the effect of the substitute component on the machine's performance is very important in the design and manufacturing processes. And minimizing machine cost and maximizing machine quality mandate predictability of machine accuracy. In this study, in order to evaluate the effects of the component's geometric errors and dimensions on the machining accuracy of gantry-type 5-axis machining centers, a geometric error analysis and virtual manufacturing system are developed based on the mathematical model for the shape generation motion of machine tool considering the component's geometric errors and dimensions, the solid modeling techniques and so on.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.556-558
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• 2000

최근 인터넷상에서 삼차원 가상세계를 기술하기 위한 VRML(Virtual Reality Modeling Language) 문서의 효율적인 작성을 위해 다양한 VRML 저작도구들이 개발되어지고 있다. 이러한 기존의 VRML 저작도구들을 실세계에 존재하는 모든 객체들에 대한 다양한 형태의 가상세계를 저작할 수 있는 범용 저작도구들이다. 하지만, 특정의 특성을 가지는 삼차원 객체들로만 구성된 가상세계를 저작하는 경우에는 더욱더 편리한 저작도구를 개발할 수 잇다. 가상 건축물의 경우 외형이 주로 직선적이고, 모든 구성 객체들을 레이어(layer)로 쌓음으로써 구현할 수 있는 특성을 지닌다. 따라서, 본 논문에서는 건축물 객체가 가지는 특성을 이용하여 전문가가 아닌 일반인도 웹 상에서 삼차원 가상 건축물을 쉽게 저작할 수 있는 저작도구를 설계하고 구현한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.143-146
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• 2005

In modern automotive control modules, mechanical failures of surface mounted electronic components such as microprocessors, crystals, capacitors, transformers, inductors, and ball grid array packages, etc., are mai or roadblocks to design cycle time and product reliability. This paper presents a general methodology of failure analysis and fatigue prediction of these electronic components under automotive vibration environments. Mechanical performance of these packages is studied through finite element modeling approach fur given vibration environments in automotive application. Using the results of vibration simulation, fatigue lift is predicted based on cumulative damage analysis and material durability information. Detailed model of solder/lead joints is built to correlate the system level model and obtain solder strains/stresses. The primary focus in this paper is on surface-mount interconnect fatigue failures and the critical component selected for this analysis is 80 pin plastic leaded microprocessor.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.1-8
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• 2001

We developed an on-line lathe simulator which can be used for a CAM education on the internet. Previously, VRML or static images such as JPG have been commonly used to achieve the same goal. With the 3D tool like VRML, it was possible to describe the movement of 3D object effectively. However, G-code based modeling and real-time visualization for the cutting process including parts being machined could not be accomplished. By using the simulator, we can machine a part with G-code input from a user or modeler, and parts being machined can be visualized in 2D as well as 3D. The developed system is based on EMCO lathe from Eshed and can be used through a web browser.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.677-682
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• 2007

Recently, a precision stage is widely used in the fields of the nano technology. In this paper, the precision stage which consists of linear motor, vision system, light source system and controller, is designed and developed for nano imprint machine. Stiffness design considering resonance frequency is important for the precision stage. A virtual machine simulation is useful for machine development the early design stage. Kinematic and dynamic simulations of XYZ stage are performed. To consider the resonance frequency and vibration effects flexible multibody dynamics are utilized with FE modeling of the structural components.