• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.143-148
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• 2003

In recent years, as the optical Communication systems are developed, the demands of essential parts such as splitter, coupler, WDM, and AWG filter are grow rapidly. The fabrication process for them is not, however, automatic. On that reason, the automation is needed for the grow of productivity. The optical alignment and attach ment is the core process in fabrication. In this paper, the 6-axis rotary stage for multi-channel optical alignment system is developed and the dynamic characteristic of this system is studied.

• 설비공학논문집
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• 제16권4호
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• pp.324-331
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• 2004

Particle Image Velocimetry (PIV) measurements have been carried out to investigate the pulsatile flow characteristics in a triangular grooved channel. The results showed that a vortex was generated at the tip of the groove and flowed into the groove rotating inside during the acceleration phase of the main stream promoting the mixing of the fluid. Then, at the deceleration phase of the main stream, the vortex entrained fluid from the relatively slow moving main stream to grow bigger than the groove size. Finally the vortex was ejected to the main stream carrying the fluid away from the groove, resulting in the enhancement of mixing between the stagnant fluid in the groove and the main stream in the channel. It was found that the fluid mixing enhancement is maximized when the pulsatile period is the same as the time duration which the vortex takes to grow larger enough to fill the groove and to be ejected to the main stream.

• 대한기계학회논문집B
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• 제24권8호
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• pp.1069-1076
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• 2000

As the environmental problems grow, the regulation of the pollutants emitted from power plants increases. Most of the pollutants in particle phase are removed by particle removal facilities, but fine particles between 0.1 micron and I micron in diameter have a low removal efficiency compared to particles in other size ranges. Therefore the present concern has concentrated on the removal of those fine particles. The purpose of this study is to grow fine particles by condensation to the range larger than I micron. Theoretically the general dynamic equation is solved with an assumption that the particle size follows a log-normal distribution to calculate the temporal behavior of the size distribution. Experiments have been carried out to compare the results with the theoretical predictions. Particles grown by condensation are sampled by impactors and observed with SEM photographs.

• 한국표면공학회지
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• 제38권4호
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• pp.174-178
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• 2005

Chemical vapor deposition technique has been used to grow epitaxial SiC thin films on Si wafers using tetramethylsilane(TMS) precursor. The films were observed to grow along (110) direction of 3C-SiC at $800^{\circ}C$. The quality of the films was significantly influenced by the TMS flow rate and growth temperature. Nanocrystal SiC films were grown at flow rates of TMS 10 sccm with $H_2$ carrier gas of 100 sccm. The temperature and gas pressure in the reactor have a great influence on the crystallinity and morphology of the SiC film grown. The growth mechanism of the SiC film on the Si substrate without the carbonization process was discussed based on the experimental results.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1908-1914
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• 2008

An alkaliphilic bacterium, Bacillus clausii SKAL-16, was isolated from soil that had been contaminated with vegetable oil. The optimal pH and general pH range for bacterial growth was 8, and 7 to 10, respectively. The bacterium could grow on tributyrin and glycerol, but could not grow on acetate and butyrate. The SKAL-16 strain excreted butyric acid during growth on tributyrin, and selectively ingested glycerol during growth on a mixture of butyric acid and glycerol. The SKAL-16 generated intracellular lipase, but did not produce esterase and extracellular lipase. The DNA fragment amplified with the chromosomal DNA of SKAL-16 and primers designed on the basis of the esterase-coding gene of Bacillus clausii KSM-KI6 was not identical with the esterase-coding gene contained in the GenBank database. Pyruvate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase activities were detected in the cell-free extract (crude enzyme).

• 한국수학교육학회지시리즈D:수학교육연구
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• 제13권3호
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• pp.235-250
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• 2009

Researchers at Truman State University in Missouri, located in the heartland of the United States, have been using materials adapted from the English translations of the sixth national primary mathematics curriculum from Korea for professional development and assessment with groups of Missouri teachers for the purpose of enhancing teachers' understanding of the fundamentals of mathematics since 2002 [gecKo Mathematics (2008). Korean Mathematics in American Classrooms. Edited by J. Grow-Maienza. Adapted from Korean Mathematics (2001). Kirksville, MO: Truman State University. http://kmath.truman.edu/]. A professional development initiative for 50 teachers conducted in Missouri this past year is reported here. Significant gains in teacher understanding of fundamental mathematics concepts and pedagogy necessary for student achievement in primary mathematics were found as a result of the initiative.

• 대한수학교육학회지:수학교육학연구
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• 제12권2호
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• pp.213-228
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• 2002

We know that curriculum is, first of all, related to teaching materials, namely, contents. Therefore, when we think of mathematics curriculum, we must take account of characteristic of mathematics. Vygotsky has studied the development of scientific concepts and everyday concepts. According to Vygotsky, scientific concepts grow down through spontaneous concepts; spontaneous concepts grow upward through scientific concepts. And mathematics is a representative of subjects dealing with scientific or theoretical concept. Therefore, his study provides scientific basis for mathematics curriculum design. In this context, Davydov notes that everyday concepts are developed through empirical abstraction, while scientific concepts require a theoretical abstraction. And Davydov constructed the curriculum materials for the teaching of number concept. Davydov's curriculum is an example of reflecting Vygotsky' theoretical view and his view about the types of abstraction. In particular, it represents mathematical characteristic of a 'science' by introducing number concept through quantitative relationship and use of signs. In conclusion, stance mathematical concepts have scientific characteristic, mathematics curriculum reflects this characteristic.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.1-4
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• 2007

Because reinforced concrete structures were being high more and more in recent year, concrete was being demanded high performance of high strength and high fluidity. But various characteristics must be confirmed besides guarantee of demand strength in ultra-high strength concrete. In ultra-high strength concrete, autogenous shrinkage and drying shrinkage grow big because of a low water cement ratio and much quantity of binder. So dangerousness of crack generation grow big in early ages. And ultra-high strength concrete is influenced by use materials more than ordinary strength concrete. In this study we were examined mix design, atuogenous shrinkage and pumpability of ultra-high strength concrete to apply on the ground.

• Journal of Plant Biology
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• 제12권1호
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• pp.35-48
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• 1969

This study was made on the taxa Chrysanthemum zawadskii complex that grow in South Korea on the basis of chromosomes, epidermis, pollens and gross morphology. I have found four types of chromosome numbers, 36, 45, 54, and 72 as a polyploidal series. Even though the gross morphology was quite similar almost the same gross morphology, chromosome number was different among the taxa. The taxa of 36 chromosomes present broad and fine lobed leaves which grow separately, broad leafed taxon in the mainland of Korea and the other's in Ullungdo Island which is isolated form the mainland in the East Sea. The taxa of 54 chromosomes are also present in the broad and in the fine lobed leaves. The fine lobed leave taxon grows in central to northern Korea and in the high altitude of mountains. Broad leafed taxon grows in central to southern Korea and comparatively lower altitude of the mountains. The taxon of 72 chromosomes is grown in the high altitude of Mt. Hallasan which is isolated from the mainland of Korea. According to this study of Chrysanthemum zawadskii complex, I have arranged the scientific names, as Chrysanthemum zawadskii subsp. latilobum, subsp. acutilobum, subsp. naktongenese, subsp. lucidum, subsp. coreanum and hybrid between subsp. acutilobum X subsp. latilobum.

• 한국주거학회논문집
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• 제12권3호
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• pp.61-73
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• 2001

This study is to examine and classify the phasic characteristics of organic thoughts in modern architecture. Organic architects have applied organic thoughts to solutions for the problems of each period in architecture since modern times. As results of this study, the architecture of organic thoughts from 1850s to 1940s could be divided into two phases. The phasic characteristics of the first phase from 1850s to 1910s was physical resemblance in real or fantastic appearance that the work of art and architecture should imitate organic forms from the view of solid empiricism. The phasic characteristics of the second phase from 1920s to 1940s was organic growth that the form appropriate to a work of art and architecture should grow from the nature of the problem itself as a system in nature grows from the view of pragmatism and was organic unity that the form and function or the form and content of a work of art should be inseparably integrated as the form in nature should grow out of the inner nature of the thing and be an expression of that inner nature from the view of expressive theory.