• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.10
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• pp.1545-1553
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• 1989

The ohmic contact behavior in HEMT structure was compared with that in MESFET one throughout the specific contact resistance and microstructural change in both structures. A Au-Ge-Ni based metallization scheme was used and the alloying temperature of the ohmic materials was changed from 330\ulcorner to 550\ulcorner. The alloying temperature to obtain the minimum specific contact resistance in HEMT structure was 60k higher than that in MESFET. The volume fraction of NiAs (Ge) in MESFET structure increases with alloying temperature and/or the alloying time, which makes the decrease of specific contact resistance at the initial stage of ohmic metallization. In contrast, the volume fraction of NiAs(Ge) in HEMT structure was not dependent upon the specific contact resistance, which implies that the ohmic contacts are dominantly formed by the Ge diffusion to 2-DEG(two dimensional electron gas) layer.

• Journal of the Korean Ceramic Society
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• v.28 no.1
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• pp.29-36
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• 1991

Microporous glasses in the system TiO2-SiO2-Al2O3-B2O3-CaO-Na2O were prepared by the phase-separation technique. Morphology and distribution of pore and specific surface area of glasses heated and leached out at various conditions were investigated by SEM and Porosimeter. Crystallization of glasses heated above transition temperature was also inspected by X-ray diffraction method. When the heating temperature and time increased, the pore size and volume increased, but the specific surface area decreased above the critical temperature. The phase-separation, specific surface area and pore size showed more sensitive change on the variation of heating temperature than of heating time. The specific surface area and micropore volume of porous glasses prepared in this study were about 120-330$m^2$/g and 0.001-0.01cc/g, respectively. Mean pore size of porous glasses were about 20-90$\AA$. Anatase phases was deposited when the parent glass was heat-treated at 75$0^{\circ}C$ for 6hrs.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.2
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• pp.239-245
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• 2012

Mulberry fruit powder was substituted for wheat flour in pound cake recipes in amounts of 0%(control), 5%, 10%, 15%, and 20%. We measured the specific gravity of the dough, specific loaf volume, dough yield, baking loss, moisture content, pH, color, identified the texture, and conducted a sensory evaluation for each pound cake. Moisture content increased according to the amount of mulberry fruit powder, but specific gravity, dough yield, and pH decreased. Specific loaf volume and baking loss increased as the amount of mulberry fruit powder increased, but not considerably. The chromatic 'L' and 'b' values were reduced as more mulberry fruit powder was added to more pound cake, While the chromatic 'a' value increased. Texture hardness, springiness, gumminess and chewiness decreased as the pound cake contained more mulberry fruit powder. Cohesiveness did not show any considerable differences beteeen the cakes. A sensory evaluation showed a high preference for the pound cake made with 10% mulberry fruit powder.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.8
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• pp.733-741
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• 2013

This is the first paper on the combustion characteristics of landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine, and it discusses the fundamental characteristics of fuel from the viewpoint of thermochemistry and thermodynamics and compares these results with experimental ones. The results show that the final pressures obtained from theoretical analysis vary under the same heating value owing to the change in the constant volume specific heat owing to the difference in the burned gas composition according to the fuel gas compositions; furthermore, the stoichiometric ratios and trends of analytical and experimental pressures coincide very well, although some minor differences are observed between the two. The root cause of the difference is the heat transfer, which changes the specific heat and lowers the temperature considerably, in the real combustion process. In addition, the large chamber volume and ignition position promote the heat transfer to the wall. Finally, the fuel conversion efficiency increases as the methane mol fraction decreases, and it is maximum when the stoichiometric ratio ranges from 0.8 to 0.9. These increases due to the composition and stoichiometric ratio could sufficiently compensate the decrease due to the specific heat ratio drop, LFG might be more advantageous than pure methane in a real engine.

• Journal of Korean Society of Transportation
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• v.4 no.2
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• pp.75-92
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• 1986

The paper contains the data collection methods and procedures employed in the study to evaluate the operational effects of stop sign and signal control at diamond interchanges. An assessment of traffic control alternatives is described in terms of operational effects of queues and travel speed. Guidelines for installing signal control at diamond interchanges are provided in terms of internal volume, left turn proportion within internal volume, and the sum of internal and external volume. The specific traffic volume guidelines were developed based on a combination of these variables affecting operational performance.

• Korean Journal of Materials Research
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• v.26 no.9
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• pp.493-497
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• 2016

This study was carried out to investigate the effect of deformation induced martensite on the damping capacity of Fe-26Mn-4Co-2Al damping alloy. ${\alpha}^{\prime}$ and ${\varepsilon}$-martensite were formed by cold working, and; deformation induced martensite was formed with according to the specific direction and the surface relief. With an increasing degree of cold rolling, the volume fraction of ${\alpha}^{\prime}$-martensite increased rapidly, while the volume fraction of ${\varepsilon}$-martensite decreased after rising to a maximum value at a specific level of cold rolling. Damping capacity was increased, and then decreased with an increasing of the degree of cold rolling. Damping capacity was influenced greatly by the volume fraction of ${\varepsilon}$-martensite formed by cold working, but the effect of the volume fraction of ${\alpha}^{\prime}$-martensite have a actually on effect on the damping capacity.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.5
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• pp.586-596
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• 2013

This study was designed to investigate the effect of Korean whole wheat flour making pan bread. Korean whole wheat flour was mixed with flour at the level of 10% (WHF10), 20% (WHF20), 30% (WHF30), 40% (WHF40) and 50% (WHF50) in order to make bread. According to mixogram, the CON (control), WHF10, WHF20, WHF30, WHF40, except WHF50 were found to be proper between 3 and 5 min. in terms of peak time. CON and WHF10 for peak value were at the level of over 60%. By increasing the ratio of Korean whole wheat flour, the pH, dough fermentation rate, volume, specific volume and moisture content were decreased, and gumminess, cohesiveness and hardness except springiness, were increased for storage days. In the crumbScan analysis, the addition of Korean whole wheat flour decreased the volume and increased the crumb fineness of pan bread. In the sensory evaluation, WHF30 showed good preference in the aspect of flavor, taste and overall acceptance, but was not significant between WHF20. CON scored the highest points in volume, specific volume, moisture content and texture, but was not significant between WHF20.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.46-50
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• 2016

This study was carried out to investigate the effect of cold working on the tensile strength of Fe-26Mn-4Co-2Al damping alloy. ${\alpha}^{\prime}$ and ${\varepsilon}$-martensite were formed by cold working, and martensite was formed with the specific direction and surface relief. With the increasing degree of cold rolling, volume fraction of ${\alpha}^{\prime}$-martensite was increased, whereas the volume fraction of ${\varepsilon}$-martensite was decreased after rising to maximum value at specific lever of cold rolling. Tensile strength was linearly increased with an increasing of degree of cold rolling. Tensile strength was strongly affected to the volume fraction of ${\varepsilon}$-martensite formed by cold working, but the effect of volume fraction of ${\varepsilon}$-martensite on the tensile strength was not observed.

• Journal of Distribution Science
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• v.21 no.3
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• pp.93-100
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• 2023

Purpose: The purpose of this paper is to confirm whether stocks belonging to the distribution industry in Korea have reversals, following large daily stock price changes accompanied by large trading volumes. Research design, data, and methodology: We examined whether there were reversals after the event date when large-scale stock price changes appeared for the entire sample of distribution-related companies listed on the Korea Composite Stock Price Index from January 2004 to July 2022. In addition, we reviewed whether the reversals differed depending on abnormal trading volume on the event date. Using multiple regression analysis, we tested whether high trading volume had a significant effect on the cumulative rate of return after the event date. Results: Reversals were confirmed after the stock price shock in the Korean distribution industry and the return after the event date varied depending on the size of the trading volume on the event day. In addition, even after considering both company-specific and event-specific factors, the trading volume on the event day was found to have significant explanatory power on the cumulative rate of return after the event date. Conclusions: Reversals identified in this paper can be used as a useful tool for establishing a trading strategy.

• Culinary science and hospitality research
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• v.17 no.4
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• pp.285-294
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• 2011

Using mulberries, a kind of functional food rising these days, we made muffins that people often eat to find the best recipe for mulberry muffins. Also, to find their quality characteristics and show possibility of making new products using mulberries, tests of pH, specific gravity, specific volume, chromaticity, mechanical quality characteristics and preference were done. As more mulberry concentrate was added, pH of muffin dough was decreased and specific gravity was increased. Specific volume was decreased as more mulberry concentrate was added Weight became heavier while volume decreased; and it seems decrease of volume was caused by additives like roughage of concentrate. For chromaticity, all L, a, b values decreased. Acceptance test of muffins with 15% substituted sample showed the highest figure and the rest of the samples were similar to one another in general. For texture, hardness and chewiness were increased as more mulberry concentrate was added, but springiness and adhesiveness were decreased. For example, general interest was the highest in 20% added group, and the order is as follows; 20% > 15% > 10% > 0% > 25%. Addition of mulberry concentrate could lower the quality of products by decreasing their volumes and increasing their hardness. Therefore, this research suggests that the optimum addition rates of mulberry concentrate should be between 15~20%.