• 한국문화재보존과학회:학술대회논문집
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• 2005.11a
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• pp.207-212
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• 2005

• The KSFM Journal of Fluid Machinery
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• v.11 no.6
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• pp.31-37
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• 2008

Film cooling effectiveness on the convergent or divergent channel was measured by pressure sensitive paint technique. The channel convergent or divergent angle was changed from $-5^{\circ}$ to $10^{\circ}$ and the tested blowing ratios were 0.5, 1 and 2. Results showed that the film cooling effectiveness on the convergent channel was not much affected by the convergent angle. With divergent film cooled surface, the film cooling effectiveness near the injection hole decreased as the divergent angle increases. However, the film cooling effectiveness at far downstream from the hole showed opposite trend. For the non-film cooled surface inclined case, the film cooling effectiveness was not much affected by the divergent angle.

• The Korean Journal of Rheology
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• v.11 no.1
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• pp.44-49
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• 1999

Effects of particulate size and frictional characteristics were examined on the melting behavior of PP (polypropylene) in a batch mixer. Powder and pellet types of PP were used and each component was blended with PE (polyethylene) wax and clay, respectively. It was observed that small size particulates, i.e. powder systems exhibit accelerated melting behavior; and it was also found that the abrasive additive acts as an effective agent for fast melting of PP powder. Retardation of melting due to the reduced friction was observed in PP pellet/PE wax blends, while melting rate of PP powder was increased by addition of PE wax.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.896-906
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• 2011

There are lots of efforts to get more and more higher level of reliability, maintainability, availability, and safety in all the railway system development process. To do a RAMS activity and process very effectively, many an information is required based on operational knowledge and manufacturer's engineering technology together. But some interests between organization in demand sector and manufacturers in supply makes it difficult to do. This paper, for this reason, presents an idea about the activities and process for SR001 system, which is newly under developing and manufacturing by SMRT. Especially, we provide it with some idea how to integrate every activity and process and to analyze it specifically for system level as well. With these efforts, we provide a typical RAMS process of SR001 that could be applicable to other rolling stock system and the improvement of the system over total life cycle phases.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1739-1742
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• 2011

Public transportation network in our country is concentrated and advanced focusing on urban area in order to secure economic feasibility. As a result, as dependence on private vehicles is relatively getting higher in public transportation vulnerable area, traffic problem occurs since the average running speed in urban area is 22.5km/h. This paper has an objective to suggest an improvement plan by selecting public transportation vulnerable area, and defining according to urban structure, formation and function, and understand traffic characteristics and draw problems. As a method selecting public transportation vulnerable area, an area with high division rate of vehicle was selected as a primary proposed site by calculating division rate of means of public transportation according to area. Final proposed site was selected by using GIS Buffering technique aiming at selected proposed site, and selecting non-benefit area 500m outside, which is the road limit distance from each subway and bus station. Lastly, the degree of improvement effect was studied by constructing imaginary public transportation network aiming at final proposed site and comparing to the amount of change in division rate of means of transportation.

• BMB Reports
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• v.49 no.6
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• pp.349-354
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• 2016

The archaeon Sulfolobus solfataricus P1 carboxylesterase is a thermostable enzyme with a molecular mass of 33.5 kDa belonging to the mammalian hormone-sensitive lipase (HSL) family. In our previous study, we purified the enzyme and suggested the expected amino acids related to its catalysis by chemical modification and a sequence homology search. For further validating these amino acids in this study, we modified them using site-directed mutagenesis and examined the activity of the mutant enzymes using spectrophotometric analysis and then estimated by homology modeling and fluorescence analysis. As a result, it was identified that Ser151, Asp244, and His274 consist of a catalytic triad, and Gly80, Gly81, and Ala152 compose an oxyanion hole of the enzyme. In addition, it was also determined that the cysteine residues are located near the active site or at the positions inducing any conformational changes of the enzyme by their replacement with serine residues.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.724-728
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• 2001

Objectives : Pituitary apoplexy is a well-described clinical syndrome resulting from pituitary hemorrhage, hemorrhagic infarction, or infarction, almost invariably occurring in the presence of an adenoma. We analyzed pituitary apoplexy with an emphasis on clinical presentation, pathology and predisposing factors. Methods : We reviewed 35 histologically proven pituitary adenomas, operated from January 1995 to August 1999, to select 8 cases which showed clinical or operative findings compatible with pituitary apoplexy. These patients were analyzed in terms of symptom and sign, hormonal status, and predisposing factors, pathologic findings. Results : Among 35 surgically treated tumors of the pituitary gland, 8 cases(23%) were diagnosed as pituitary apoplexy. The pathologic findings revealed hemorrhage(7 cases) and infarction(1 case) of pituitary adenomas. One case had predisposing factor of appendectomy. The most common presenting symptom and sign were sudden severe headache and visual disturbance. Conclusion : We treated pituitary apoplexy surgically and obtained good outcomes. Pituitary apoplexy due to massive infarction of the pituitary gland is very rare condition but surgical treatment by trans-spheniodal surgery showed a good result.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.103.1-103.1
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• 2010

Recently domestic wood pellet boilers are installed in rural and forestry houses. The fuel price per lower heating value of wood pellet is about 20 % lower than that of heating oil on July 2010. In spite of lower price of wood pellet, a few user of wood pellet boiler complain expensive fuel cost. One of this reason is inaccurate or improper air-fuel ratio setting of wood pellet boiler. O2 concentration of flue gas of domestic wood pellet boiler is about 9.7 % and there are few domestic wood pellet boiler which can control air-fuel ratio automatically. We tested a domestic wood pellet boiler in changing boiler thermal output and air-fuel ratio. The nominal boiler thermal output is 25 kW (21 500 kcal/h). We measured thermal efficiency and flue gas concentrations such as CO and NOx at each boiler thermal load with various air-fuel ratio. The results show that if air flow rate is the same as full load and part load, thermal efficiency of part load of 40 % drops about 7.7 %p compared to boiler full load case.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.104.1-104.1
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• 2010

We investigated combustion characteristics of wood pellets in a combustion equipment with adjusting amount of flue gas. Maximum temperature in a combustion chamber was $850^{\circ}C$. Higher heating Value of a domestic wood pellet tested is 19.1 MJ/kg and water content was 8.3%. Amount of flue gas causes big effect on burning characteristics in $450{\sim}600^{\circ}C$. Wood pellet does not burn in low temperature atmosphere less than $450^{\circ}C$ and low flue gas flow rate. We made burning the pellet that is made in Korea, USA, Chile and Canada. Color of foreign pellets are bright brown and they made by mainly sawdust. Korean pellet is a dark brown color because it contains bark. There are some differences in the result of elementary analysis and technical analysis. According to the result of burning experiment, burning times of each countries's pellet are similar.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.369-372
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• 2002

To remedy both the degradation and saturation of the output voltages in the modified Dickson pump, a new multistage charge pump circuit is presented in this paper. Here using PMOS charge-transfer switches instead of NMOS ones eliminates the necessity of diode-configured output stage in the modified-Dickson pump, achieving the improved voltage pumping gain and its output voltages proportional to the stage numbers. Measurement indicates that VOUT/3VDD of this new pump circuit with two stages reaches to a value as high as 0.94V even with low VDD=1.0 V, strongly addressing that this scheme is very favorable at low-voltage memory applications.