• Journal of the Korean institute of surface engineering
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• v.14 no.3
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• pp.161-168
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• 1981

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.1
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• pp.71-76
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• 2009

In a running blower, there are various exciting forces which can generate noise. The noise of an running industrial fan or blower depends on the structure of a fan, the machining accuracy of each element, and assembled conditions. Many studies have been carried out to reduce the noise of it. In this study, 3-hole buffs are used in pipe of blower to study the influence the number and position of buffs on the noise reduction at inlet and outlet in pipe. Commercial engineering software ANSYS and SYSNOISE were employed to analyze the characteristics and reduction ratio of pressure. It is concluded that optimal position and number of buffs in pipe of blower to show the least reduction ratio of pressure.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1880-1884
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• 2008

Cleaning is required following CMP (chemical mechanical planarization) to remove particles. The minimization of particle residue is required with each successive technology generation, and the cleaning of wafers becomes more complicated. In copper damascene process for interconnection structure, it utilizes 2-steop CMP consists of Cu CMP and barrier CMP. Such a 2-steps CMP process leaves a lot of abrasive particles on the wafer surface, cleaning is required to remove abrasive particles. In this study, the buffing is performed various conditions as a cleaning process. The buffing process combined mechanical cleaning by friction between a wafer and a buffing pad and chemical cleaning by buffing solution consists of tetramethyl ammonium hydroxide (TMAH)/benzotriazole(BTA).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.19-24
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• 2010

The noise of an running industrial fan or blower depends on the type of a fan, the machining accuracy and assembled conditions of each element, and buffs. Many studies have been carried out to reduce the noise through silencer in blower. In this study, 3 types of buffs which have different hole are employed in pipe of blower to study the influence the number and arrangement of buffs on the noise reduction at inlet and outlet in pipe. Commercial engineering software ANSYS was employed to analyze the characteristics and reduction ratio of pressure. Experimental results shows that optimal one can reduce the reduction ratio of noise as much as 16 percents in the laboratory. Good agreement was found between the analysed ratio of noise reduction and those obtained from the experiments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.9 s.102
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• pp.1060-1069
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• 2005

Silencers are engineering devices that are designed to attenuate sound waves propagating in a flowing medium. The muffler type silencer has a series of chambers in parallel or series utilizing the reflection and expansion characteristics of the expansion chambers, sidetubes, branch resonators, and tailpipes to attenuate the sound. To Improve the performance of industrial blower silencer of muffler type which is employed in petrochemical plant, this paper seeks its optimal arrangement of buffs by experimental method and suggests optimal arrangement of buffs. Experimental results show that the optimal one suggested can reduce the noise level as much as 14 dB (or 18 dB(A)) in the laboratory and as much as 4 dB(A) compared to that of the existing silencer on the ground.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.452-460
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• 2010

Any theory of liquid should account for interactions between molecules, since molecules in a liquid are close to each other. For this matter statistical-mechanical methodology has been used and various models have been proposed on the basis of this methodology. Among them Kirkwood-Buff solution theory has attracted a lot of interest, because it is regarded as being the most powerful. In this article Kirkwood-Buff solution theory is revisited and its key equations are derived. On the way to these equations, the concepts of pair correlation function, radial distribution function, Kirkwood-Buff integration are explained and implemented. Since complexity of statical mechanics involved in this theory, the equations are applied to one-component systems and the results are compared to those obtained by classical thermodynamics. This may be a simple way for Kirkwood-Buff solution theory to be examined for its validity.

• Korean Journal of Logic
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• v.6 no.1
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• pp.1-18
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• 2003

1989년 네일버프(B. Nalebuff)에 의해서 두 봉투의 역설이 제시된 이래 많은 철학자들이 이 역설에 많은 논의가 있었데 이 역설에 대한 논의를 다시 촉발시킨 글은 1997년의 잭슨(F. Jackson)과 멘지스(P. Menzies)와 오피(G. Oppy)가 발표한 논문이다. 이 글은 잭슨 등의 논문에서 제시된 두 봉투의 역설에 대한 설명을 토대로 두 봉투의 역설이 생긴다고 생각하는 이유는 무엇이고, 구체적으로 어떤 경우에 역설이 생길 수 있는지를 살펴본다. 그리하여 필자는 다음 두 가지를 주장할 것이다 첫째 두 봉투의 역설이라고 불리는 것은 봉투에 들어있는 금액이 무한하고 동시에 그 금액의 평균값이 무한한 경우만 발생할 수 있을 뿐이고, 이는 내가 선택한 봉투 안의 기대값을 실제로 계산할 수 없는 경우이다. 둘째로 기대값이 실제로 계산될 수 있는 그 외의 경우, 역설은 발생하지 않으며 역설이 발생한다고 생각하는 것은 자신의 봉투 안의 금액을 고정적인 것으로 상대방의 금액을 가변적인 것으로 해석하는 잘못으로부터 기인하는 것이다. 요컨대 기대값이 계산될 수 있는 일반적인 경우 두 봉투의 역설이 생긴다고 생각하는 것은 잘못이고 그 경우 역설은 발생하지 않는다는 것을 논증할 것이다.

• Journal of Korea Game Society
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• v.15 no.4
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• pp.49-58
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• 2015

Due to the improving mobile environments, we can play RPG in not only computer online field but also mobile field. It is difference from hardware environment between them so that mobile RPG has been changed and modified to play in mobile environment except RPG's frame and basic element. This Study has investigated the model to evaluate the balance of battle that is based on the RPG. Although there is an assessment model studied with a focus on the MMORPG, It is difficult to apply to the entire balance in RPG especially mobile RPG. Former model has used only basic element because there were so many kinds of variables such as user's controls, other players and objects in game. The reason why that model just gave a guide line about battle balance. In this paper, the new assessment model to include the balance factors such as BUFF, NURF and PASSIVE could be possible for applying the balance of mobile RPG on recent trends. As a result, the new model can measure numerical calculations compared to the previous model.