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        검색결과 1,001

        261.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 홍삼 유화 음료의 유통기한 예측을 위하여 수행하였다. 저장기간 동안 이화학적 특성 (산도, pH, 지방구크기, 색도) 및 관능적 특성의 변화를 주기적으로 조사하였다. 저장 초기에 홍삼 유화 음료의 산도, pH 및 지방구 크기는 거의 변화하지 않았으나 저장 후반기(70일 이후)에는 유의적으로 변화하 였으며 이는 주로 Maillard reaction 의한 것으로 추정하였다. 관능특성과 이화학적 특성들과의 상관분석을 통하여 색도 a 값(적색도)을 홍삼 유화 음료의 이화학적 품질지표로 설정하였다. Arrhenius 식에 의한 a값 변화에 대한 활성화 에너지 및 Q10-value는 각각 13.37 kcal/mol, 1.56-2.14로 조사되었으며, 홍삼 유화 음료의 유통기한은 상온(20℃) 보관의 경우 730일(약 2년)로 예측되었다.
        4,000원
        262.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선박의 안전 확보를 위해 준수해야 하는 IMO 복원성 규칙에는 복원정 곡선(GZ Curve) 등에 관한 내용이 다양하게 규정되어 있다. 이 IMO 복원성 규정에는 다양한 항목의 만족 기준이 제시되고 있으나, 선박을 운항하는 선장에게 선박의 복원성능을 종합적이며, 간편하게 제공할 수 있는 방법은 부재한 상황이다. 이를 위해 본 연구에서는 복원성을 하나의 값으로 표현할 수 있는 지수를 개발하였다. IMO에서 규정한 선박의 6가지 복원성 항목과 대상선박의 적재상황에 따른 복원성 계산결과를 바탕으로 지수산정식이 도출되었다. 또한 개발된 지수산정식을 적용하여 다양한 화물 적재 상황별 복원성 지수(Stability Index)를 계산하였으며, 복원성능의 전반적인 정도를 수치적으로 적절하게 설명할 수 있음을 검증하였다. 이는 선박의 선장에게 복원성 평가하고 판단하는데 도움을 줄 것으로 판단된다.
        4,000원
        263.
        2017.12 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 용액 공정으로 제작된 단분자 기반의 유기 반도체 전계효과 트랜지스터에 적용된 보호막이 유기 트랜지스터의 전기적 안정성에 미치는 영향에 대해여 살펴보았다. Solvay社에서 제공한 용액 공정형 유기 단분자 반도 체를 채널로 사용하여 제작한 유기 트랜지스터는 약 1 cm2/Vs의 상대적으로 높은 이동도를 보였으며, 대략 2.5 ~ 20 k Ωcm 범위의 낮은 접촉저항을 가진 것으로 측정되었다. 무엇보다 중요한 것은, 제작한 유기 트랜지스터에 불소원자가 함유된 Hyflon AD를 보호막으로 적용하였을 때, 보호막을 적용하기 전에 비해 훨씬 더 향상된 전기적 안정성을 보였 다. 이는 불소원자가 함유된 Hyflon AD 고분자막이 대기 중의 수분을 효과적으로 차단하기 때문으로 추측된다.
        4,000원
        264.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, single layer latticed domes have attracted many designers and researchers’s attention all over the world, because single layer latticed domes as space structure are of great advantage in not only mechanical rationality but also function, fabrication, construction and economic aspect. Yamada developed the shape factor S which represents the shape of spherical latticed dome from a structural perspective as well as a geometric perspective. According to a prior study, the structural behavior and the buckling characteristics of the latticed dome were mostly noticeable when the shape factor of latticed dome was in the range of 1.5 to 5. That is, S, in the range of 1.5 to 5, are able to estimate not only overall buckling, but also member buckling and nodal buckling. In this study, we developed shape models using various size of members with the fixed rise-span ratio. One particular characteristic of the latticed dome is that it is not only light in weight but also high in strength. But the aiming at the use of light-weight materials and at the minimized section of members may result in buckling to cause an unstable state of the overall structure when the external force reaches a limitation. Especially, the structural strength is disadvantageous to the snow loads than the earthquake loads because of light-weight, and is greatly affected by the conditions of loading. This paper is to develop the structural stability according to the shapes and load conditions for single-layer latticed spherical dome with 300m span.
        4,000원
        265.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the homogeneity and stability of standard samples for proficiency testing in indoor air quality within the country (formaldehyde, benzene, toluene, ethylbenzene, p-xylene, styrene, TVOC) were evaluated. The procedures and statistical analysis methods applied in ISO/IEC 13528 (2009) and KS A ISO Guide 35 (2005) were applied as evaluation methods. The homogeneity evaluation was a statistical analysis of repeated measurements of each of the 11 ports and between the 11 ports concentration data. As a result, the coefficient of variation (CV) was within the range of 1.9%~5.9%. The difference between the ports was found to be insignificant and met the statistical standard specified in KS Q ISO 13528. The stability evaluation was assessed by the change in concentration over the long-term stability of the standard samples stored for 90 days. The coefficient of variation (CV), which was within the range of 2.6%~9.0%, exhibited changes in the concentration of the long-term stored standard samples. However, the results satisfy the statistical standard specified in KS A ISO Guide 35. Overall, there is no significant difference between the homogeneity of the standard samples by the port and the stability of the long-term stored samples. Therefore, it is considered to be an appropriate method to supply standard samples in an indoor air quality proficiency test.
        4,000원
        266.
        2017.11 구독 인증기관·개인회원 무료
        Curcumin is an active polyphenolic compound with antioxidant, anti-inflammatory and antitumor properties. Curcumin, however, is highly unstable under physiological conditions due to its low stability in acidic and alkaline conditions. Therefore, the objective of this study was to investigate the effects of enzyme-treated rice starch as a wall material on the stability of curcumin in oil-in-water emulsion under different pH conditions. The rice starch was treated using 4-a-glucanotransferase for different time periods and their molecular weight distribution was measured by HPSEC. Curcumin was encapsulated within lipid droplets of O/W emulsion prepared with Tween 20 and the modified rice starch in the aqueous phase at different concentrations (0, 2.5, 7.5 and 10 wt%). The temperature and pH stability of the system were determined respectively by measuring particle size, zeta potential and retention of the curcumin loaded in the emulsion after one-week storage in the solutions with different pH and temperature conditions. The average molecular weight of the modified starch decreased with treatment time. The 96h treated rice starch had the lowest molecular weight while the 1h treated starch mainly consisted of high molecular weight components. The storage temperature did not significantly influence the stability of curcumin emulsion. However, the particle size of the emulsion with modified starch slightly increased when stored at acidic pH condition, which might be attributed to starch aggregation. The curcumin retention was higher for the samples with the modified starch than the control at all concentrations. The pH stability of the curcumin was also higher than the control at all pH conditions. Specifically, the 1h treated starch showed the best performance regarding curcumin protection in emulsion, which might be attributed to the high viscosity that retarded the curcumin release. Further research needs to be conducted on the mechanism.
        267.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fish skin peptide-loaded liposomes were prepared in 100 mL and 1 L solution as lab scales, and 10 L solution as a prototype scale. The particle size and zeta potential were measured to determine the optimal conditions for the production of fish skin peptide-loaded liposome. The liposome was manufactured by the following conditions: (1) primary homogenization at 4,000 rpm, 8,000 rpm, and 12,000 rpm for 3 minutes; (2) secondary homogenization at 40 watt (W), 60 W, and 80 W for 3 minutes. From this experimental design, the optimal conditions of homogenization were selected as 4,000 rpm and 60 W. For the next step, fish peptides were prepared as the concentrations of 3, 6, and 12% at the optimum manufacturing conditions of liposome and stored at 4ºC. Particle size, polydispersion index (pdI), and zeta potential of peptide-loaded liposome were measured for its stability. Particle size increased significantly as manufacture scale and peptide concentration increased, and decreased over storage time. The zeta potential results increased as storage time increased at 10 L scale. In addition, 12% peptide showed the formation of a sediment layer after 3 weeks, and 6% peptide was considered to be the most suitable for industrial application.
        4,000원
        268.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 제품혁신에 초점을 맞추어 기술혁신이 기업의 수익과 재무안정성에 미치는 영향을 분석하고 기업의 지속성장을 위한 전략적 시사점을 도출하는 데 목적이 있다. 제품혁신은 신제품개발 및 도입으로 정의한다. 기업의 수익은 종업원 1인당 매출액과 매출액 증가율로 측정하고, 재무안정성은 자기자본대비 부채비율과 유동비율로 측정한다. 실증분석 은 제품혁신의 내생성을 고려하여 2단계 추정법을 사용하였고, 분석자료는 「인적자본기업패 널(HCCP)」의 1차(2005년)~6차(2015년) 자료와 한국신용평가(주)의 기업재무자료를 병합한 자료이다. 분석결과에 의하면, 제품혁신은 기업의 지식자본스톡과 인적자원투자, 시장선도전 략 등에 영향을 받으며, 제품혁신이 활발히 이루어지는 기업일수록 1인당 매출액과 매출액 증가율이 높고 부채비율은 낮으며 유동비율이 높다. 이러한 분석결과는 기술혁신투자와 이 를 통한 제품혁신이 기업의 단기수익 창출 및 장기적인 재무안정성을 촉진하는 중요한 전략 이라는 것을 의미한다.
        6,000원
        271.
        2017.11 구독 인증기관·개인회원 무료
        An advanced organic-inorganic composite membrane is investigated to enhance mechanical and chemical stability of membrane for vanadium redox flow battery (VRFB). In order to improve chemical and mechanical stability of membrane, organic polymer is composed with inorganic material for VRFB. The inorganic material can be used as anti-oxidant for improving membrane chemical stability during long-term operation of VRFB. However, higher concentration of inorganic particles increased the hydrophobicity which may make membranes brittle. Therefore, the optimization of inorganic materials in polymer membrane is carried out for the application VRFB.
        272.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Solder paste is widely used as a conductive adhesive in the electronics industry. In this paper, nano and microsized mixed lead-free solder powder (Sn-Ag-Cu) is used to manufacture solder paste. The purpose of this paper is to improve the storage stability using different types of solvents that are used in fabricating the solder paste. If a solvent of sole acetate is used, the nano sized solder powder and organic acid react and form a Sn-Ag-Cu malonate. These formed malonates create fatty acid soaps. The fatty acid soaps absorb the solvents and while the viscosity of the solder paste rises, the storage stability and reliability decrease. When ethylene glycol, a dihydric alcohol, is used the fatty acid soaps and ethylene glycol react, preventing the further creation of the fatty acid soaps. The prevention of gelation results in an improvement in the solder paste storage ability.
        4,000원
        273.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the non-thermal sterilization effect of methods such as high hydrostatic pressure (HHP) and UV-irradiation (specifically with regard to the storage stability and shelf-life of carrot juice. The microbial counts of the non-sterilized product increased from 5.51 to 7.34 log CFU/mL up to the fifth day, and then decreased to 5.46 log CFU/mL at six days. UV-irradiation was increased from 2.37 to 4.92 log CFU/mL. HHP was maintained under the 3 log CFU/mL. The pH of UV-irradiation and HHP was maintained withing the range of 6.29~6.30 and 6.20~6.22 during storage. However, the pH arising from non-sterilization decreased from 6.31 to 4.49. The color of non-sterilization changed significantly during storage, but UV-irradiation and HHP were similar during storage. The β- carotene content of non-sterilization was noted to have decreased from 269.45 to 65.19 μg/mL during storage. The UV- irradiation and HHP decreased from 263.46 and 268.35~281.16 μg/mL to 243.42 and 244.09~269.29 μg/mL, respectively. In conclusion, these findings suggest that HHP can be used for the pasteurization, or sterilization, of carrot juice and the optimal condition is two minutes.
        4,000원
        274.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study was to investigate the properties and stability of the wet noodles added to nanoemulsion as a industrial model system, and in so doing, survey practical applicability in the food industry. In order to test out these objectives, the characteristics and stability of the wet noodles added to nanoemulsion were investigated and their cooking characteristics and capsaicinoids loss were examined. As a result, the test results showed that the findings indicated that the post-cooking loss of capsaicinoids in the wet noodles added to double-layer nanoemulsion covered with chitosan was less than the losses in the wet noodles added to any other noodles. More especially, this demonstrates that the noodle added to double-layer nanoemulsion covered with chitosan scored significantly higher than the others with reference to their cooking properties, color, texture, stability for storage stability, and sensory evaluation. These results show that the findings of this study demonstrated that the noodles added to nanoemulsions could be produced as a food-grade merchandise because they could provide enhanced encapsulation capacity of capsaicinoids and higher acceptability.
        4,500원
        275.
        2017.10 구독 인증기관·개인회원 무료
        The exosomes are the most studied nanometer-sized extracellular vesicles (40-100 nm) in eukaryotic cell. Exosomeharbors various molecular components of their cell origin, including nucleic acids and proteins, and it is involved in intraand intercellular communication. These characteristics make exosomes to be a prospective biomarkers, therapeutic agents,or drug delivery vehicles. Edible insect industry is rapidly growing up in Korea. The insect exosomes were isolated fromthe larvae of Korean rhinoceros beetle, Allomyrina dichotoma, and White-spotted flower chafer, Protaetia brevitarsis, sothat they can be used for diagnosis of insect disease. The stable preservation of exosome is very important for diagnosisand research, especially for long term storage. Here, the stable recovery of exosome isolated from hemolymph of A. dichotomalarva was evaluated by analyzing exosomal protein and RNA after storage in -70°C for three months.
        276.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to estimate the effect of home or hetero fermentative lactic acid bacteria(LAB) on chemical composition, fermentation quality, and aerobic stability of rye silage. Rye forage was harvested at dough stage(28.9% of dry matter), chopped to 3-5 cm length, and divided into 4 piles for different inoculations as treatment, following 1) No additives(CON); 2) Lactobacillus plantarum at rate of 1.5 x 105 cfu/g of fresh forage(LP); 3) L. buchneri at rate of 1.2 x 105 cfu/g of fresh forage(LB); and 4) Mixture of LP and LB at 1:1 ratio(MIX). Rye silage was ensiled into 20 L bucket silo in quadruplicate for 0, 1, 4, 7, and 100 day periods. After 100 days of ensiling, the silage treated with LB had lower acid detergent fiber content(p<0.05), but higher in vitro dry matter digestibility(p<0.05). The LB and MIX reduced (p<0.05) pH more rapidly than CON and LP across the ensiling days, but had no difference on 100 days. Silage treated LP had lowest(p<0.05) acetic acid, but highest(p<0.05) propionic acid. In contrast, LB treated silage had highest(p<0.05) acetic acid, but lowest(p<0.05) propionic acid with the absence of butyric acid. On microbial count, LP treated silage had lowest(p<0.05) LAB, yeast, and aerobic stability, whereas LB and MIX treated silages had highest(p<0.05). Mold was not detected across all silages. Therefore, it could be concluded that heterofermentative LAB solely or combo with homofermentative LAB might improve in vitro dry matter digestibility, fermentation characteristics, and aerobic stability of rye silage harvested at dough stage.
        4,000원
        277.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was performed to analyze the annual variation of growth traits of soybean to determine the information of less sensitive traits and stable cultivars based on the environmental conditions. Sowing was carried out on June 2 for each year and the test plot was arranged in three replicates by randomized complete block design with thirty soybean varieties including two landraces during the period 2014-2015. The weather conditions during the test period were quite different with extremely low precipitation and longer sunshine duration in 2015. The variation of characteristics related to growth period such as days of growth, days of maturity, days of flowering and 100-seed weight were less in spite of different environmental conditions. While the variation of the number of pods per plant was high. Considering growth and seed characteristics like the number of pods per plant, the number of seeds per pod, and 100-seed weight which are linked directly to the yield, cultivars such as Shingi, Daewonkong, Danbaegkong, and Daepung for beancurd and soypaste, Pungwon, Haepum and Shingang for soy-sprout and Seoritae for cooking with rice were more stable and are expected to have high yield in Suwon, the south-central part of South Korea. These results are useful for the selection of breeding resources to develop cultivars with high stability under changeable weather condition.
        4,200원
        278.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A metallic oxide layer of a heat-resistant element contributes to the high-temperature oxidation resistance by delaying the oxidation and has a positive effect on the increase in electrical resistivity. In this study, green compacts of Fecralloy powder mixed with amorphous and crystalline silica are oxidized at 950oC for up to 210 h in order to evaluate the effect of metal oxide on the oxidation and electrical resistivity. The weight change ratio increases as per a parabolic law, and the increase is larger than that observed for Fecralloy owing to the formation of Fe-Si, Fe-Cr composite oxide, and Al2O3 upon the addition of Si oxide. Si oxides promote the formation of Al2O3 and Cr oxide at the grain boundary, and obstruct neck formation and the growth of Fecralloy particles to ensure stable electrical resistivity.
        4,000원
        279.
        2017.07 구독 인증기관·개인회원 무료
        With the development of information technology, the market situation is changing more rapidly than ever. The change is most rapid in the preferences and lifestyle of consumers. For companies to survive in such an environment, it is indispensable to develop innovative and competitive new products by better understanding the needs of consumers. Any novel and meaningful idea of a new product basically originates from knowledge, which plays an important role in the performance of new products because it is the most valuable asset for a business entity. In this study, the author considers the knowledge sharing process as a dynamic aspect based on the term “knowledge,” carrying a static meaning as used in the existing research. The nature of the knowledge sharing process pertaining to new product development has been largely divided into three terms and then re-established. The author focuses on a new product development team as the subject of sharing and providing knowledge on new products, and regards the solution to problems that may arise in the development process as the stability of the team. The moderating effect was examined by the relationship between the type of knowledge sharing process and the outcome of the new product with the variable of team stability. The results indicate that the convergence and similarity of the knowledge sharing process affect new product performance as positive variables, whereas the tacitness of the knowledge sharing process does not lead to a significant result in terms of performance of new products. This study also shows that the stability of the team has a positively direct effect on the outcome of the new product. Thus, the convergence process of various kinds of knowledge positively affects the diversity and innovation of new product concepts. Moreover, the same recognition area or shared goal awareness and sense of responsibility play important roles in the performance of the new product. The moderating effect of team stability between the type of knowledge sharing process and new product performance is described in the convergence and tacitness of the knowledge sharing process. In the process of merging existing knowledge with new knowledge or sharing embedded knowledge in the members with, the activity wherein the members of the NPD team communicate and collaborate with each other over a long period of time will provide opportunity to improve the performance of the new product. The purpose of this paper is to examine the relationship between the type of knowledge sharing process, the stability of the team, and new product performance. Academic and managerial implications and the directions for future research are discussed as well.
        280.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to identify the effects of two trunk stability exercise types on the gait factors of stroke patients. We randomly divided 24 old elderly patients with hemiplegia, who were hospitalized due to stroke, into a two groups, each with its own six-week exercise program: one that used of a dynamic trunk stability exercise using with physio-balls(n=12) and a group of one that used a static trunk stability exercise using on mats(n=12). After measuring the participants gait ability a sin a pre-test, we again measured their ability again as in a posttest after two-for both types of six-week exercise programs for each group. The analysis of the data analysis showed that both ball and mat exercise programs significantly improved the participants’ gait velocity and stride length; cadence, however, was significantly changed only by the ball exercise program. In conclusion, both types of trunk stability exercise may be useful in improving the gait ability of stroke patients, and, in particular, the former can be used as an exercise method that effectively significantly affects more various other gait factors.
        4,000원