• 베이커리
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• no.7 s.324
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• pp.142-143
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• 1995

• Defense and Technology
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• no.4 s.182
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• pp.22-35
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• 1994

냉전의 종식과 걸프전 이후 미국은 군의 역할과 임무를 계속적으로 재조정하고 있으며 국방예산 역시 계속하여 감소일로에 있다. 이에 따라 미공군도 현재의 임무와 미래의 역할을 조화시키면서 가장 효율적이고 경제적인 무기체계와 전력구조를 마련하기 위하여 여러가지 노력을 경주하고 있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.854-857
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• 2000

Chemical Mechanical Polishing(CMP) has been accepted as one of the essential processes for VLSI fabrication. However, as the polishing process continues, pad pores get to be glazed by polishing residues, which hinder the supply of new slurry. This defect makes removal rate decrease with a number of polished wafer and the desired within-chip planarity, within wafer and wafer-to-wafer nonuniformity are unable to be achieved. So, pad conditioning is essential to overcome this defect. The eletroplated diamond grit disk is used as the conventional conditioner, And alumina long fiber, the .jet power of high pressure deionized water and vacuum compression are under investigation. But, these methods have the defects like scratches on wafer surface by out of diamond grits, subsidences of pad pores by over-conditioning, and the limits of conditioning effect. To improve these conditioning methods. this paper presents the Characteristics of Ultrasonic conditioning aided by cavitation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.86-89
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• 2003

Chemical Mechanical Planarization(CMP) has been accepted as the most effective processes for ultra large scale integrated (ULSI) chip manufacturing. However, as the polishing process continues, pad pores get to be glazed by polishing residues, which hinder the supply of new slurry. And pad surface is ununiformly deformed as real contact distance. These defects make material removal rate(MRR) decrease with a number of polishied wafer. Also the desired within-chip planarity, within wafer non-uniformity(WIWNU) and wafer to wafer non-uniformity(WTWNU) arc unable to be achieved. So, pad conditioning in CMP Process is essential to overcome these defects. The eletroplated or brazed diamond conditioner is used as the conventional conditioning. And. allumina long fiber, the jet power of high pressure deionized water, vacuum compression. ultrasonic conditioner aided by cavitation effect and ceramic plate conditioner are once used or under investigation. But. these methods arc not sufficient for ununiformly deformed pad surface and the limits of conditioning effect. So this paper focuses on the characteristics of diamond conditioner which reopens glazed pores and removes ununiformly deformed pad away.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.151-161
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• 1991

I tried to specify the taxa of Fagaceae in Korea by the character of their pollen grains. The light microscope(LM) and the Scanning electron microscope(SEM) were used to examine the pollen grains of 19 taxa, 5 genera. The result are as follows. 1. The pollen of Fagaceae in Korea could be grouped into four types and 4 subtypes. 1) Fagus type 2) Castanea type 3) Lithocarpus, Castanopsis type 4) Quercus type (1) Cyclobalanopsis subtype (2) Prinus subtype (3) Dentatae subtype (4) Cerris subtype. 2. The morphology of the granula on the pollen of Quercus was closely related to the differantiation of the shape of the cup scales. 1) The uniformity of branching granula on the pollen grain surface corresponds to the morphological features of the concentric arrangement of cup scales. 2) The morphological features of the pollen grain surface intermingled with large or small granula, simple-granula and tuber granula which have small points of circular prominence, corresponded to those of short cup scales. 3) The morphological features of the polllen grain surface intermingled with large or small granula, simple-granula and tuber granula with an apex of amoeba type corresponded to those of Q. dentata Thunb, with thin, fine and long cup scales. 4) The morphological features of the pollen grain surface intermingled with large of small granula of with only simple-granula, corresponded to those of Q. acutissima carr. with thick, fine and long cup scales. 3. The result of cluster analysis by coding the sculpture pattern of the pollen grain surface, the existence and nonexistence of surface perforate, the grain size and granula type were coincident with the system of classification of plants and showed an intimated relationship even under th level of species.