• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2572-2576
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• 2009

The wafer prober is used in mass production process of semiconductor chips. The chuck in wafer prober must have a uniform temperature distribution when the chuck is heated or cooled. The temperature distribution of prober chuck is measured by using a thermocouple when the chuck is cooled. The temperature distribution is also calculated by using a CFD program, FLUENT. The measured temperature and calculated temperature show similar distributions. A modified coolant circuit distribution for the improving temperature uniformity is suggested based on the numerical analysis results.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.1
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• pp.49-52
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• 2002

This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. Glass coating on the stainless steel substrate was 125 $\mu\textrm{m}$ thick. The adhesion of glass coating was found to be excellent such that it was able to withstand temperature cycling to over $300^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and high applied voltages. The deviations at elevated temperatures and high applied voltages are due to increased leakage current as the electrical resistivity of glass coating drops.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.42-44
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• 2003

The paper presents the method and apparatus for conformal photoresist spray coating on the 3D structured substrate. The system consists of a high-temperature-rotational chuck, ultrasonic spray nozzle module, angle control module and nozzle moving module. The coating uniformity is acquired by controlling the moving speed of the ultrasonic spray nozzle across the substrate which is rotated constantly. To coat the photoresist conformally the spray angle of the nozzle and the temperature of the substrate are controlled during spray coating. The rotational chuck can be heated up by hot air or $N_2$. The photoresist (AZ1512) has been coated on the 3D structured wafer by spray coating system and the characteristics have been evaluated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.10 s.253
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• pp.957-965
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• 2006

A high-performance hot chuck is designed as a heating device for an ultra-precision flip-chip bonder with infrared alignment system. Analysis of design requirements for thermal performance leads to a radiative heating mechanism employing two halogen lamps as heating source. The heating tool is made of silicon carbide characterized by high thermal diffusivity and small thermal expansion coefficient. Experimental tests are performed to assess heat-up performance and temperature uniformity of the heating tool. It is revealed that the initial design of hot chuck results in a good heat-up speed but there exist a couple of troubles associated with control and integrity of the device. As a means to resolve the raised issues, a revised version of heating tool is proposed, which consists of a working plate made of silicon carbide and a supporting structure made of stainless steel. The advantages of this two-body heating tool are discussed and the improved features are verified experimentally.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.153-153
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• 2003

우리나라와 일본에서 특유의 향미로 인해 오래 전부턴 조미식품으로 애용되었던 참기름은 최근 토코페롤과 세사몰류 항산화 성분의 인체 기능성으로 인해 유지시장에 서 더욱 증가일로에 있다. 지금까지 좋은 향미와 품질을 지닌 참기름을 얻기 위해 참깨의 roasting조건에 대한 많은 연구가 이루어져 왔으나, 가공 전처리인 이물질 제거를 위한 수세 작업 및 탈수 작업에 관한 연구는 아직까지 없었다. 따라서, 본 연구에서는 이물질을 제거하는 수세 작업을 한 후 수분의 제거 정도 즉, 참깨가 roasting 과정으로 들어가기 직전의 수분 함량이 참기름의 제조와 품질에 미치는 영향을 알아보고자 하였다. 시료 350g을 수세 후 24 hr, 48 hr, 120 hr 실온에서 송풍 건조를 시켜 참깨 자체의 수분 함량을 각각 17.14%, 11.78%, 6.08%로 조절하여 착유하였다. 수분함량이 다른 세 군 시료를 각기 24$0^{\circ}C$, 26$0^{\circ}C$, 28$0^{\circ}C$에서 20분간 roasting하여 착유된 참기름에 대해 이화학적 품질 특성을 알기 위해 seed와 oil의 색도, 산가, 과산화물가, TBA가, 점도와 굴절률을 측정하였다. 또한, sample single test(5점 척도)를 이용한 관능검사를 행하여 benny, nutty, burnt flavor 및 전체적 만족도와 향의 강도 항목을 조사한 후 상관분석을 실시하였다. roasted sesame seed와 oil에 대해 색도를 측정하고 분산 분석을 실시한 결과, 참깨의 색도 중 L＊가 R-suare=1로서 전체 자료가 모형을 잘 설명해줌을 의미하는데, 고수분 시료일수록 whiteness가 높게 나왔고(60이상), 고온일수록 미미한 감소가 나타났다. 이것은 수분함량이 시료의 건화속도에 요인자로 작용함을 말해준다. oil의 L＊도 마찬가지 경향을 보이나 고수분 시료구의 경우(40 이상), 타 시료구(20이하)에 비해 백색도가 높은 것을 볼 수 있어 볶음에 더 많은 시간을 투자해야 함을 보여주었다. 그러나 a＊와b＊는 시료구간 뚜렷한 차이는 보이지 않았다. 참기름에 대하여 화학적 품질 평가로 산가는 수분함량 시료구별로 1.204, 3.28, 1.862가 측정되었고, 과산화물가는 0.493, 0.169, 0.315가 기록되었고, TBA가 또한 13.45, 10.27, 11.73로서 시료의 수분 함량과 상관없이 초기 산패 경향은 거의 없는 것으로 나타났다. 참기름의 물리적 품질요소로서 점도는 평균 85.57 cS, 굴절률은 평균 1.471로서 시험구간 이화학적 차이는 없는 것으로 드러났다. 관능검사결과의 상관분석에서는 beany와 burnt flavor간에 -0.9975(p＜0.05)의 음상관을, nutty flavor와 전체favor간에 0.99662의 양상관(p$\leq$0.05)을 보였고, burnt와 향의 strength, 전체 favor와 nutty flavor간에도 상관성이 높았다. strength와 nutty 항목간에도 0.982의 높은 상관을 보였으나 전체 favor와 burnt 항목간에는 높은 음상관(-0.9862)을 보였다. 고수분 함량의 시료는 28$0^{\circ}C$의 고온 처리시 외에는 향미가 좋지 못한 것으로 나타났고, 수분량이 적은 실험구는 고온일수록 향과 고소함은 강해지나 수분 보유량이 적어 타 실험구에 비해 탄내가 많이 발생하였다. 향미 만족도는 중간 수분량, 26$0^{\circ}C$ 볶음 처리구가 가장 컸다. 결론적으로 수분함량을 10~12%로 조절한 시료로 26$0^{\circ}C$~28$0^{\circ}C$에서 20분 이내로 roasting할 때가 좋은 참기름을 얻을 수 있을 것으로 사료된다.

• Economic and Environmental Geology
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• v.50 no.3
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• pp.225-238
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• 2017

In this study, two viable measures of mean length and cumulative thickness of sand layers as important spatial statistics responsible for optimal SAGD (Steam Assisted Gravity Drainage) location for oil sand development were compared. For the comparisons, various deposits composed of sand and clay media were realized using a geostatistical simulator and the extent of steam chamber is simulated using multiphysics numerical simulator (dualphase flow and heat transfer). Based on the spatial statistics of each realization and the corresponding size of simulated steam chamber, the representativeness of two candidate measures (cumulative thickness and mean length of permeable media) were compared. The results of the geostatistical and SAGD simulations suggest that the mean length of permeable media is better correlated to the size of steam chamber than the cumulative thickness. Given those two-dimensional results, it is concluded that the cumulative thickness of the permeable media alone may not be a sufficient criterion for determining an optimal SAGD location and the mean length needs to be complementarily considered for the sound selections.

• KSBB Journal
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• v.10 no.2
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• pp.212-220
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• 1995

An obligatory type II methanotroph Methylosinus trichosporium OB3b was cultivated on methanol as a sole carbon and energy source. The effects of methanol concentration, pH, temperature, nitrogen source and phosphate concentration on cell growth were investigated and the results were compared with the growth on methane, which had been studied previously. When $(NH_4)_2SO_4$ was used as a nitrogen source, the maximal specific growth rate (${\mu}max$) on methanol was $0.20hr^{-1}$ and the carbon conversion efficiency(CCE) was 43%. In comparison, on methane, ${\mu}max$ and CCE were $0.08hr^{-1}$ and 32%, respectively. Ammonia was found to be a better nitrogen source for methanol-growing cells. Cell yield on nitrogen (YX/N) was the same regardless of nitrogen source as 7.14g dry cells/g N, but the yield on methanol(YX/N) was higher with ammonia(0.8g dry cells/g MeOH) than with nitrate(0.64g dry cells/g MeOH). Optimal pH and temperature were 7.0 and $30^{\circ}C$, respectively. Methanol inhibition on cell growth was observed at above 0.5%(v/v). Inhibition by phosphate was observed at above 60mM, although the inhibition on methanol dehydrogenase activity started at a much lower level of 20mM. Based on the experimental findings, the cellular physiology of M. trichosporium OB3b growing on the two closely-related carbon sources were discussed extensively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.2028-2042
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• 1994

Properly defining signal and noise in a self-organizing system like ART(Adaptive Resonance Theory) neural network model raises a number of subtle issues. Pattern context must enter the definition so that input features, treated as irrelevant noise when they are embedded in a given input pattern, may be treated as informative signals when they are embedded in a different input pattern. The ATR automatically self-scales their computational units to embody context and learning dependent definitions of a signal and noise and there is no problem in categorizing input pattern that have features similar in nature. However, when we have imput patterns that have features that are different in size and nature, the use of only one vigilance parameter is not enough to differentiate a signal from noise for a good categorization. For example, if the value fo vigilance parameter is large, then noise may be processed as an informative signal and unnecessary categories are generated: and if the value of vigilance parameter is small, an informative signal may be ignored and treated as noise. Hence it is no easy to achieve a good pattern categorization. To overcome such problems, a Coupled-ART neural network capable of modularized categorization of patterns is proposed. The Coupled-ART has two layer of tightly coupled modules. the upper and the lower. The lower layer processes the global features of a pattern and the structural features, separately in parallel. The upper layer combines the categorized outputs from the lower layer and categorizes the combined output, Hence, due to the modularized categorization of patterns, the Coupled-ART classifies patterns more efficiently than the ART1 model.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2263-2273
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• 2000

Catalytic wet air oxidation of acetic acid over Mn-Ce based catalysts deposited on various supports ($SiO_2$, $TiO_2$, $ZrO_2$), $ZrSiO_4$, $ZrO_2(10wt%)/TiO_2$) have been carried out in high pressure microreactors. Also, promotional effects by small addition(O.5~1.0 wt%) of p-type semiconductors (CoO, $Ag_2O$, SnO) have been investigated. From the screening tests for initial activity ranking, both Mn(2.8)-Ce(7.2 wt%) and Ru(O.4)Mn(2.7)-Ce(6.9 wt%) supported on $TiO_2$ were selected as the promising reference candidates. In $Mn-Ce/TiO_2$ reference catalyst, addition of small amount of each p-type semiconductor (Co, Sn and Ag) resulted in activity promotional effect and the degree of the increase was in the following order: Co> Ag > Sn. Especially, $Mn-Ce/TiO_2$ promoted with 0.5 wt% Co gave the 2.6 folds activity increase compared to the reference case attributing to the surface area increase as well as synergy effect. In $Ru-Mn-Ce/TiO_2$ reference catalyst, only Co(1.0 wt%) promoted case showed a little reaction rate increase.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.15-30
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• 1998

The variation of the catches of Skipjack(Euthynnus pelamis) and the relationships between the SST and the fishing ground is examined using the catches data of skipjack obtained by Iwawada Fisheries Cooperative of Chiba Prefecture in Japan from 1982 to 1988. The annual mean catch for Skipjack was 151,375.1kg. the annual fluctuation of catch was that the catch in 1984 was increasing, but it was decreased less than 50% in 1985, and was repeated after being a little recovered in 1986, and it was recovered with the level of 1984 in 1988. The fluctuation of catch for Skipjack in every fishing term is that daily mean catch of the primary fishing term (January, February and March) is 894.6kg, but the middle fishing term(April and May) more than four times of the primary fishing term is 3,666.0kg, the last fishing term(June and July) was decreasing at 767.9kg and the fishing ground gradually becomes extinct. The annual mean SST in fishing ground was an extent of from $19.0^{\circ}C$ to $20.2^{\circ}C$, the mean SST of every year except 1983 was from $19.0^{\circ}C$ to $19.9^{\circ}C$. It is said that the optimum SST of Skipjack in Sotobo sea area is the degree of $19.0^{\circ}C$. Therfore, the thing which will guess the time and the location appeared the optimum SST is the very important factor to operate efficiently. About the extent of SST in fishing ground, it was from $17.0^{\circ}C$ to $19.0^{\circ}C$ on March, from $17.5^{\circ}C$ to $20.5^{\circ}C$ on April and from $17.5^{\circ}C$ to $23.5^{\circ}C$ on May, which the extent of SST was gradually larger and larger, on June from $21.0^{\circ}C$ to $23.5^{\circ}C$, fishing ground was formed only the degree of SST more than $21.0^{\circ}C$.