• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.181-181
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• 2011

도로는 국내 물류를 담당하는 중요한 기반시설로 국내 경제성장의 중추적인 역할을 담당하고 있다. 특히, 1970년대 개통된 경부고속도로는 우리나라의 대동맥으로 산업 성장의 파급효과를 가져오는 기반이 되었고, 공학적인 차원에서도 도로 포장재료를 경험 및 과학적으로 분석하여 적용하는 계기로 도로공학발전의 초석이 되었다. 과거에 적용된 도로 포장재료는 기술자의 경험에 의존하여 배합설계가 진행되었으며, 중차량의 비중이 많은 지역은 강성포장을 적용하고, 상대적으로 중차량이 적은 구간은 연성포장을 적용하는 설계를 따랐다. 하지만, 강성포장을 대표하는 시멘트 콘크리트 포장은 시공상의 복잡함과 시멘트 콘크리트 특성상 강도발현을 위해서 일정기간 이상의 양생일수가 필요하므로, 도로건설의 인프라 구축이 시급한 지역에서는 사용의 제약이 따른다. 연성포장을 대표적하는 재료로는 아스팔트 콘크리트 포장을 들 수 있다. 강성포장보다는 상대적으로 시공상의 편리함과 일정기간의 양생이 필요하지 않아 도로 포장재료로서 그 적용성이 우수하다. 과거에는 아스팔트 콘크리트 포장의 종류가 단순화되어 표층, 기층에 대표되는 몇몇 혼합물이 도로 포장재료로 사용되었다. 도로공학의 학문적 발달과 함께 도로포장의 전반적인 기술이 향상되고 있다. 과거의 도로 기능은 국가 경제발전을 위한 산업용 원자재의 운반이 주요 기능을 담당하고 있는 반면, 국민의 경제적 수준이 증대되고 자가용의 보급이 보편화되면서 도로 이용의 주체가 국민 개개인으로 변화되고 있고, 그 요구조건도 다양화되고 있다. 이에 발맞추어 도로공학의 기술적 향상으로 다양한 기능을 발휘할 수 있는 도로포장재료가 개발되고 있으며, 대표적인 제품으로는 배수성 포장, 반강성 포장, 보수성 포장, 탄성 포장, 저소음 포장 등이 있다. 본 연구에서는 기능성 포장의 하나인 저소음 포장의 특성 중 생산성능을 평가하였다. 생산성능이란 저소음포장을 현장 플랜트에서 생산하였을 경우의 특성을 분석하는 과정으로, 실내 실험으로 최적화된 재료의 배합은 이상적인 조건을 적용하여 결정된 것으로 입고된 현장 골재 및 생산 플랜트 조건에 따른 그 배합 및 물성이 변동을 가져올 수 있다. 특히, 저소음 포장은 기존의 아스팔트 포장과 달리 적용되는 골재, 아스팔트의 재료가 고성능을 발휘하기 위하여 특수한 재료를 적용해야 한다. 배합설계에서도 개립도 아스팔트 혼합물에 적용되는 내구성분석 절차를 따라야 하므로, 실내 배합설계 혼합물과 현장 생산 혼합물간의 물리적 특성에 차이를 나타낼 수 있다. 따라서, 본 연구에서는 실내 및 현장 혼합물의 전반적인 물리적 특성의 차이를 분석하여 저소음 포장의 현장 생산성능을 확인하였다. 분석요소로는 혼합물의 기초물성면에서는 밀도, 공극률을 분석하였으며, 실내 내구성면에서는 마샬안정도, 잔류안정도를 분석하여 실내 및 현장 혼합물의 물성차이를 분석하였다. 기초물성을 평가할 수 있는 밀도와 공극률에서는 생산 현장 혼합물이 실내 혼합물 보다 높은 밀도와 낮은 공극률을 나타내고 있으며, 이에 상관하여 강도특성을 분석할 수 있는 마샬안정도도 생산 현장 혼합물이 다소 높은 강도를 발휘하였다. 또한, 수분에 대한 안정성을 평가하는 인자인 잔류 안정도에서는 실내 및 현장 혼합물 모두 우수한 성능을 발휘하였다.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.304-317
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• 2020

This study conducted selected two sites in Geumnamhonam and four sites in Honam-Jeongmaek for vegetation survey with consideration to the location environment and anthropogenic impacts to investigate the vegetation structures of the Geumnamhonam-Jeongmaek·Honam-Jeongmaek ridge areas. Using TWINSPAN (two-way indicator species analysis), each of the two ridge areas were categorized into seven plant communities. The differential species in the TWINSPAN technique indirectly represent the environmental factors of plant communities, and the community types of the two ridge areas were divided based on environmental factors such as altitudes above sea level, soil moisture, and disturbance. These results were in harmony with the environmental factors of the DCA (detrended correspondence analysis) axis 1. In the low-lying areas of both ridge areas, afforestation tree species such as Pinus rigida and P. thunbergii were in competition with native tree species. As such, in the low-lying areas, artificial vegetation disturbance was severe due to afforestation and development projects. In relatively highland areas, such as upper slopes, and top areas, in the ridge, the vegetation type with the dominance of Quercus mongolica, Q. variabilis, and P. densiflora was preserved well. As for differences between the two ridge areas, communities dominated by Q. mongolica were distributed widely in Geumnamhonam-Jeongmaek because of the altitudes above sea level, and the latitude of this ridge area are higher than those of Honam-Jeongmaek. On the other hand, communities dominated by P. densiflora were distributed along with communities dominated by Q. mongolica, and communities dominated by Q. variabilis appeared in Honam-Jeongmaek because it is adjacent to the south coast. In quantitative vegetation analysis such as TWINSPAN and DCA, changes in species composition and the extracting environmental factors that cause the changes are important. To that end, the removal of accidental emergent species, the establishment of an investigation plan that assumes environmental factors, and the selection of the optimal analytical method suitable for the characteristics of the survey data are necessary.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1011-1016
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• 1999

This study was performed to search a physical method having high yield and quality and minimum environmental pollution for extraction of pectin from apple pomace. Based on the physical solubilization of plant cell wall under the condition of high temperature, pressure and shearing stress, apple pomace was treated by a corotating intermeshing type twin-screw extruder with the diameter-to-length ratio of 1/20. The specific mechanical energy of extruder was introduced as system parameter for extrusion process modeling and the shaft speed, feed rate and moisture content as process variables. The yield, average molecular weight and galacturonic acid content of water-soluble polysaccharides obtained by extrusion were, respectively, modeled with the linear functions of the system parameter which was of the form as a linear function of process variables. The specific mechanical energy increased with increase of shaft speed and with decrease of feed rate and moisture content. Out of process variables, moisture content had the greatest effect on specific mechanical energy. The yield increased with increase of specific mechanical energy while the average molecular weight and galacturonic acid content increased with its decrease. In aspects of yield and quality of pectin, the results from this study showed the possibility to replace a traditional acidic method with the extrusion treatment of this study.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.942-948
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• 2002

When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and the strength development may be delayed. One of the solution methods to resolve these problems is to reduce freezing temperature of concrete by the use of chemical admixture called Accelerator for freeze protection. In this study we Investigate the effect on the strength development of cement mortar using accelerator for freeze protection with the variable curing condition. As the result of this study, the mortar using accelerator for freeze protection show continuously the strength development in curing condition of -5$^{\circ}C$. And the compressive strength under variable temperature condition was higher than constant temperature condition in same maturity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1457-1461
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• 2014

The feasibility of incorporating cinnamon powder as a value-added food ingredient in cookies was investigated. Density of dough was not significantly affected by cinnamon powder (P>0.05). Moisture content, spread ratio, and loss rate of cookies decreased significantly with increasing levels of cinnamon powder (P<0.05). Lightness ($L^*$) and yellowness ($b^*$) decreased, whereas redness ($a^*$) as well as hardness increased significantly with higher amount of cinnamon powder (P<0.05). 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical scavenging activities were significantly elevated (P<0.05), and they were well-correlated. The consumer acceptance test indicated that addition of cinnamon powder to 4% had a favorable effect on consumer preferences in all attributes. Based on overall observations, cookies with 4% cinnamon powder can take advantage of the functional properties of cinnamon powder without sacrificing consumer acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.132-139
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• 2004

This study was peformed in order to compare general components, color, free amino acid, fatty acid and organic acid contents between commercial doenjang (C-1, C-2, C-3) and green tea doenjang (GT). The moisture content in green tea doenjang was higher than that in commercial doenjang, but the contents of crude protein, carbohydrate and energy in commercial doenjang were higher than those in green tea doenjang. The crude lipid and fiber contents of commercial doenjang were similar to green tea doenjang. Catechin content of green tea doenjang was 2.3%. The total content of free amino acids in commercial doenjang ranged from 2,739∼6,380 mg% in which it showed wide variation among samples and the total content of free amino acids in green tea doenjang was 3000 mg%. Glutamic acid was almost high in commercial doenjang except one product but green tea doenjang was low. Linoleic acid (51%) was the highest content among the fatty acids. The major organic acid in both commercial and green tea doenjang was oxalic acid and its content in commercial times higher than in green tea doenjang. The antioxidant activity of green tea doenjang was higher than that of commercial doenjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1677-1685
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• 2012

The autolysate and hydrolysate of a common squid liver, Todarodes pacificus, were prepared. Autolysis (liver ratio, pH, temperature) and Protamex-treated hydrolysis (pH, temperature, ratio of protease to liver) conditions were optimized by response surface methodology using central composite design for under 1 hr of hydrolysis time. The desirability profile indicated that maximum DH could be achieved at a squid liver of 93.5%, pH 6.4, and $47^{\circ}C$ in autolysis, while that of Protamex-treated hydrolysis did at a Protamex-to-squid liver level of 0.33%, pH 6.0, and $55^{\circ}C$. Three amino acids, proline, cysteine, and methionine, were not detected in the total amino acid composition of the Protamex-treated hydrolysate, while they were detected in the free amino acid composition. Cadmium was $8.32{\pm}0.03$ mg/100 g-powder for raw, $3.56{\pm}0.02$ mg/100 g-powder for the autolysate, and $13.26{\pm}0.04$ mg/100 g powder for the Protamex-treated hydrolysate. The major molecular weight ranged from 1.0 to 1.5 kDa for the autolysate and from 210 to 470 Da for the Protamex-treated hydrolysate. Food functionalities of the autolysate, such as surface hydrolphobicity, emulsion activity index, emulsion stability, water, and fat adsorption, were similar to the Protamex-treated hydrolysate. Both the autolysate and Protamex-hydrolysate showed high inhibitory activities on the angiotensin-I converting enzyme. Cell toxicity against the HepG2 cell line was not detected in the autolysate or the Protamex-treated hydrolysate by 200 ${\mu}g/mL$.

• Journal of Aquaculture
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• v.21 no.2
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• pp.102-106
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• 2008

This study was conducted to evaluate extruded pellets(EP) for the growth of sub-adult flounder Paralichthys olivaceus by comparing with raw fish-based moist pellet(MP). Two replicate groups of 150 fish per each tank(initial mean weight $594{\pm}6.5g$) were fed one of two EPs(EP1 and EP2) and a MP for 32 weeks. Survival was not significantly affected by experimental diets. Final mean weight of fish fed the EP1 was not significantly different from that of fish fed the MP, but that of fish fed EP2 was significantly lower than that of fish fed EP1 and MP (P<0.05). Feed efficiency and protein efficiency ratio of fish fed the EP1 and EP2 were significantly higher than those of fish fed MP(P<0.05). Daily feed intake of fish fed the EPs was significantly lower than that of fish fed MP(P<0.05). Condition factor was not significantly different among all groups. The contents of moisture, crude protein and lipid in dorsal muscle were significantly affected by experimental diets(P<0.05). Based on the results of this study, the dietary formulations used in EP1 and EP2 could be applied in the practical extruded pellet feeds for sub-adult flounder(594-1,126 g).

• Culinary science and hospitality research
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• v.21 no.2
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• pp.141-153
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• 2015

We investigated the feasibility of incorporating Aster yomena powder into cookies as a value-added food ingredient. In this study, we assessed the quality characteristics and antioxidant activity of cookies containing various concentrations (0, 3, 5, 7 and 9%) of Aster yomena powder(AYP). For the analysis, quality characteristics such as density and pH of dough, spread factor, moisture content, color(L, a, b), hardness, DPPH radical scavenging activity and sensory properties were measured. The Hardness and DPPH radical scavenging activity of the cookies significantly increased with increasing concentrations of AYP, whereas pH and density of the dough, L value of the cookies significantly decreased. The results of sensory properties showed that cookies made with 3% and 5% AYP did not differ significantly from the control in color, taste, and overall quality. Texture scores for the 3% and 5% AYP groups ranked significantly higher than those of the other groups. Taken together, the results of this study suggest that AYP is a beneficial ingredient for increasing the consumer acceptability and functionality of cookies. The quality characteristics of the 3% and 5% added samples exhibited significantly similar or higher values as compared to those of the controls, raising the possibility of developments in health-functional cookies. The results of the sensory evaluation produced very significant values for color, appearance, texture, and overall quality of instrumental analysis.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.31-36
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• 2005

Cauliflower mushroom (Sparassis crispa) is an edible mushroom that shows remarkably high contents of $1,3-{\beta}-D-glucan$ compared to other edible mushrooms. The mushroom is known to give high antitumor and immunologic activities, thus the mushroom is recently cultivated in Japan and Korea. However, cultivation methods are being kept in secret or under patents by some companies with complicated procedures. This study was conducted to solve the problem by providing a simple method for the cultivation of cauliflower mushroom. We could produce the mushroom using sawdust-based media of Larix leptolepis, Pinus densiflora and P. koraiensis with addition of barley flours and sugar. The ratio of the sawdust : barley flours : sugar used for this study was 80:20:3 in dry-weight base, and the water content was adjusted as 65%. The productivity was somewhat different among the species of sawdust media and the strains of Sparassis crispa for the cultivation, and the mushroom production reached up to 177g from 650g base(productivity : 27%). Thus, this medium is strongly recommended as a practical cultivation method for cauliflower mushroom. By the way, further study for the determination of adequate concentration of barley flour and the selection of proper strain for each sawdust species is needed.