• Journal of Broadcast Engineering
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• v.25 no.7
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• pp.1052-1062
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• 2020

As the market demand for immersive media increases, an efficient streaming method is required in consideration of network conditions while maintaining the user's immersive experience. Accordingly, transmitting a viewport with relatively high-quality, such as tile-based streaming, is mainly used. But there still remains a lot of technical challenges, such as quickly providing a new viewport in high-quality according to the gaze. To solve the aforementioned problem, in this paper, we propose a method of configuring and transmitting a supplemental tile set through the predicted direction, and a range of stable utilization of the transmitted supplemental tile set.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.13-25
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• 2003

The lack of consideration for statistical properties in Taguchi's three­level linear graphs is rectified. We propose a new set of linear graphs for the three­level orthogonal arrays according to the maximum resolution criterion. In the presence of two­factor interactions however, the serious bias of all the estimated effects as well as the estimated variance shows that these designs should not be employed. The various alternative designs are discussed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2005.09a
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• pp.157-172
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• 2005

기존 단말기에 Fine Pitch (0.3mm) WLCSP를 개발/적용해 봄으로써 SMT 조립 한계로 인식되고 있는 Pitch인 0.4mm이하의 접속 기술을 검증함. Set Maker 입장에서 Fine Pitch를 가진 Customized Package를 적용할 경우, Design 단계에서부터 부품, 기판, 조립공법, Infrastructure등을 동시에 검토해야 함. 이동단말의 소형화/박형화 경쟁이 가속화 되는 가운데 Package Pitch만을 고려해 볼 때, 2006년에는 0.4mm Pitch를 가진 BGA의 적용이 확대 될 것으로 예상되며 일부 제품에서 0.3mm Pitch Package의 적용도 예상됨.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1576-1579
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• 1991

This paper discusses on the machine loading and tool allocation (MLTA) problem. Mathematical formulation of the problem is given first. Then a heuristic approach based on Group Technology (GT) is presented to deal with the MLTA problem effectively. By using this approach, part-tool group generation and their assignment to adequate machines can easily be obtained in consideration of the work load on each machine, the number of tool-set replacement, and the total number of cutting tools required through the interactive setting of the desired machine utilization rate.

• Journal of the Korean Statistical Society
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• v.31 no.2
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• pp.143-152
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• 2002

In an effort to make a right choice among ratio estimation strategies and PPS sampling strategies, we conduct an empirical investigation of the relative performances of three ratio estimation strategies and four PPS estimation strategies using a set of 12 natural populations. The quality of a strategy is measured in the traditional way, namely with the consideration of efficiency, achieved coverage rate of the nominal 99% confidence interval and approach to normality (asymmetry).

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.427-432
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• 1999

An electrci method for the rapid determination of chloride diffusion coefficient in concrete is proposed considering the electrical migration term in the Nernst-Plank equation. The experimental set-up for this method is basically that for PD index by Dhir, excluding some change in the experimental parameter values in consideration of reliability, simplicity and rapidity of the accelerated test method. Experimental results show that 30mm of specimen thickness, 10 volt of supplied potential, and 5M of chloride ion concentration are optimal

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.499-505
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• 2000

The shape of the KHST, and of the power car in particular, is largely determined by aerodynamic considerations. At high speeds, air resistance accounts for the major part of overall resistance to forward motion. Further points to be considered are environmentally undesirable acoustic phenomena and pressure waves. Minimizing power requirements and environmentally-unfriendly noise and pressure waves are thus major objectives in the development of the KHST. When deciding on the aerodynamic design of the power car, the entire train set has to be taken into consideration. This paper describes the design process and results about the front shape of the KHST.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.467-474
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• 2001

The KNR(Korean National Railroad) is trying to set a new rail standard to back up the speed-up policy of the conventional railways. This work has passably significance since the rail standards used were introduced from Japan without the consideration on our situation. The contact analysis between wheel treads and rail heads, attended with complex calculation and the wear experiments taken long time should be accomplished for the exact investigation to establish a new rail standard. However, this paper just concentrates the structural investigation of the proposed rail standard and the dynamic analysis between trains and rail models with intent to shift the above procedure on the next step.

• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.163-165
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• 2007

The authors have reviewed many mathematical thermal mode lings of bipropellant propulsion system in literatures to gather basic data for developing a computer program which analyses the performance of bipropellant propulsion system. In this paper COMS and its propulsion system is briefly introduced for understanding. The set of first order nonlinear differential equations is reviewed and considered as candidate equations for the program development.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.115-120
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• 1999

The shape of the KHST, and of the power car in particular. is largely determined by aerodynamic considerations. At high speeds, air resistance accounts for the major part of overall resistance to forward motion. Further points to be considered are environmentally undesirable acoustic phenomena and pressure waves. Minimizing power requirements and environmentally-unfriendly noise and pressure waves are thus major objectives in the development of the KHST. When deciding on the aerodynamic design of the power car, the entire train set has to be taken into consideration. This paper describes the design process and results about the front shape of the KHST.