• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.120-127
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• 2023

Recently, metaverse has attracted great attention worldwide with the development of related technologies and the demand for on-tact systems. The ideal metaverse should constitute a virtual world more similar to the realistic society with physical interactions. However, there are many constraints when we construct a virtual world using the existing commercialized metaverse platform. In this paper, we design and implement a university campus-based metaverse which minimizes the constraints, and create a virtual environment maps very similar to the real-world using Unity engine, Photon cloud and Playfab SDK for multi-user accessible to virtual world as a personal avatar. Also, this work includes attractive interaction based on exchange between users. Lastly, we illustrate our implemented metaverse works on Android phone, and it works without difficulty in terms of performance.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.31-37
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• 2001

In this paper, we developed an automated program for the modeling and simulation of three-dimensional roller gear cam mechanisms. The three-dimensional modeling for a roller-gear cam employs coordinate transformations based on the con-tact condition. the wire frame modeling followed by the shading technique using triangular meshing elements incorporat-ed the to reduce the number of data and computational load. Computer simulations for two kinds of products for rollger-gear cam mechansim illustrate the relative motion between the modeled roller-gear cam and a turret and thus show the effectiveness of the proposed modeling.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.553-556
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• 2002

A numerical study on the use of the momentum interpolation mettled for flows with a large body force is presented. The inherent problems of the momentum interpolation method are discussed first. Numerical experiments are performed for a typical flow involving a large body force. The tact that the momentum interpolation method may result in physically unrealistic solutions is demonstrated. Numerical experiments changing the numerical grid have shown that a simple way of removing the physically unrealistic solution is a proper grid refinement where there is a large pressure gradient. An effective way of specifying the pressure and pressure correction at the boundary by a local mass conservation near the boundary is proposed, and it is shown that this method can effectively remove the inherent problem of the specification of pressure and pressure correction at the boundary when one uses the momentum interpolation method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.94-98
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• 2012

The behavior of ozone micro bubble cleaning system was investigated to evaluate the solution as a new method of solar cell wafer cleaning in comparison with former conventional RCA cleaning. We have developed the ozone dissolution system in the ozonated water for more efficient cleaning conditions. The optimized cleaning conditions for solar cell wafer process were 10 ppm of ozone concentration and 12 minutes in cleaning periods, respectively. We have confirmed the cleaning reliability and cell efficiencies after ozone micro bubble cleaning. Using this new cleaning technology, it was possible to obtain higher efficiency, higher productivity, and fast tact time for applying cleaning in the fields on bare ingot wafer, LED wafers as well as the solar cell wafer.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.359-361
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• 2023

관광산업은 뉴 노멀(New Normal) 시대에 언택트에서 온택트(On-tact)형식의 메타버스(Metaverse)로의 새로운 관광 패러다임 전환을 맞이하고 있다. 이에 이 연구는 뉴 노멀 시대에 직면하여 관광산업의 변화방향에 대한 문제의식을 가지고서 지역의 관광활성화 방안 중에서도 체류형 지역 관광 활성화를 위한 방안으로 메타버스를 활용한 관광 홍보마케팅에 대한 효율적인 방안들에 대해 제안한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2016-2025
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• 1994

A hierarchical planning strategy for dextrous manipulation of multifingered hands with soft finger contact model is proposed. Dextrous manipulation planning can be divided into a high-level stage which specifies the position/orientation trajectories of the fingertips on the object and a low-level stage which determines the contact forces and joint trajectories for the fingers. In the low-level stage, various nonlinear optimization problems are formulated according to the contact modes and integrated into a manipulation planning algorithm to find contact forces and joint velocities at each time step. Montana's contact equations are used for the high-level planning. Quasi-static simulation results are presented and illustrated by employing a three-fingered hand manipulating a sphere to demonstrate the validity of the proposed low-level planning strategy.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.1-6
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• 2001

An analytical thermal model of HESG(higt efficiency speed grinding) is presented, in which the heat flux to workpiece in grinding zone is modeled as time dependent and moves along a slope decided by contact chord(approximation of con-tact arc). By matching the maximum surface temperature of workpiece derived from this model to the maximum surface temperature of grinding wheel composite as done in Lavins simple thermal model, the relation of maximum surface tem-perature and energy partition of workpiece to grinding speed is obtained. In high speed grinding, as wheel speed increases, energy partition decreases with no regard to table speed.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.97-110
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• 2000

Production schedule and realization quantity of Large type bus [929(HD), 928, 928-A(SD), 937E/L, 937/L,] were analyzed in order to intruoduce FMS(Flexible Manufacturing System) appropriate for varities of customer desire and multi-item, small lot production. And this paper is aimed to propose introduction method of FMS, analyzing zig tools change times and idle times with production line and workers as an object. According to analysis results, only simple spec., depending on bus type, changed with decrease in production. For 929(HD), 928,928-A(SD), 937Eh, 937/L bus type, there was no harmony between schdule and realization. Therefore, it caused many difficulties in part supply. And there was loss of manpower and reduction of productibility due to idle time of process with bus type change. Production processes were operated inefficiently because tact time exceeded or shortaged of allow time.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.6
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• pp.124-130
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• 1989

For the higher density DRAM'S, innovations in fabrication process and circuit design which have led to dramatic density improvement are discussed from the desinger's perspective. A new dynamic RAM cell called Trench Epitaxial Transistor Cell(TETC) using trench technics and SEG have been developed for use in future megabit DRAMS. Storge electrode with $n^+$-polysilicon and $n^+$-source electrode are self-contacted in TETC. With keeping the storage capacitance large enough to prevent soft errors, the cell size reduced to 30% compare with existing BSE cell by utilizing the vertical capacitor made along the isolation region.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.651-657
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• 1996

Industrial products are getting more and more complex. The number of parts or components and the variety of manufacturing processes are increasing. This leads to rapid product oriented machine tools. The process integrated CNC lathe is one of the these machine tools which can produce numerous parts and various machining processes and reduce the lead time and non-machining time. Therefore this study deals with the design technique of a process-intergated CNC lathe which can reduce the tact time and production cost by the speed-up of the tooling system and the high-speed machining oriented construction of 2 spindles and 2 turrets.