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        검색결과 1,895

        1661.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 요트 계류장과 같은 소형 해상 부유체의 위기수준을 모니터링하기 위한 확률 기반 위기평가기법(Probability based risk Evaluation Techniques, PET)의 이론적인 접근 방법을 기술하였다. PET는 5단계 척도의 위기 기준을 이용한 위기 판단 절차가 핵심 개념이다. 이러한 5단계 척도들은 폐형 공식을 이용한 해상 부유체 운동의 응답함수에 대한 누적확률분포에서 계산했다. 그리고 위기기준을 갖는 PET의 위기판단 절차를 제안하였다. PET의 유용성 검증을 위하여 시뮬레이션 실험을 하였는데, 실험에는 해상 부유체의 운동 측정에 사용할 ADIS16405 센서의 전기특성을 갖는 모의 신호를 이용하였다. 실험결과, PET의 위기평가 오차는 최대 5.0 수준에서 0.38 수준으로 나타났다. 이 결과로부터 제안한 PET가 모니터링 기법으로 사용 가능함을 확인하였다.
        1662.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, the quality characteristics and antioxidant activity of mulberry salad dressing prepared with yam juice during storage at 5℃ for four weeks were evaluated. The salad dressing was prepared with a salad base, mulberry, omija, and yam (4:4:6:1 or 4:4:6:3). Fresh yam juice was added to the salad dressing at 0, 7, and 18% levels. After four weeks storage, the pH increased whereas the acidity decreased. As the yam concentration increased, the pH increased to 3.84 and the acidity decreased to 0.14%. The Hunter color L (lightness), b (yellowness), and a (redness) values decreased over the storage period. After four weeks storage, the viscosity increased from 83.2 to 158.5 cp according to the amount of yam juice that was added. The antioxidant activity, such as the DPPH radical scavenging activity, and the total polyphenol content of the salad dressing improved as the yam concentration increased. Moreover, according to the storage time, the peroxide value did not increase. These results show that the mulberry salad dressing to which omija and fresh yam juice were added maintained its freshness with high antioxidative activity during storage.
        1663.
        2012.11 서비스 종료(열람 제한)
        To check the serviceability of K-UHPC structures, we need the guideline for the allowed crack width in various environment. To setup the guideline, direct tensile test of reinforced K-UHPC tensile members was implemented. The test results show very small crack width, and the allowed values for the ordinary concrete can be used for K-UHPC structures.
        1664.
        2012.11 서비스 종료(열람 제한)
        In this study, a bridge maintenance system is developed to generate performance based maintenance strategy by considering the life cycle cost(LCC). And it is proposed that the concept of generally annual maintenance are practically and easily used to perform LCC analysis. Some of generally annual maintenance data are suggested through existing data analysis due to the proposed concept and LCC analysis of by a real bridge structures is preformed by comparison with a current approach. This paper presents the development of bridge maintenance strategy and can be utilized as an efficient tool to provide the best economical bridge maintenance scenario corresponding to the various constraints and requirements of bridge agency.
        1665.
        2012.10 KCI 등재 서비스 종료(열람 제한)
        We studied the ozone concentrations generated by low-temperature dielectric barrier discharge plasma reactor after adding air and phytoplankton to control the ozone concentrations in seawater. We also examined the numbers of bacteria and Vibrio spp. after treatment using the plasma reactor. As the airflow rate was increased, more ozone was removed. Although marked variation in the ozone decrease was observed with and without airflow, the rate of ozone removal did not increase proportionately with the airflow rates. The ozone concentration decreased with increasing organic matter and time. The amount of organic matter seems to be an important factor decreasing the dissolved ozone concentration in liquid. The ozone concentration was 0.07, 0.32, 1.28, and 2.3 mg/L when operating the plasma reactor for 30, 60, 180, and 300 s, respectively; i.e., the ozone concentration increased with the reactor operating time. The initial numbers of bacteria and Vibrio spp. were 800 and 480 CFU/mL, respectively. After operating the plasma reactor at a flow rate of 6 L/min for 30 s, no bacteria or Vibrio spp. were detected. The disinfection effect of this plasma reactor seems to be superior to that of a conventional ozone generator.
        1666.
        2012.10 KCI 등재 서비스 종료(열람 제한)
        In this study, we devised a regeneration process for deactivated catalyst which used in SCR denitrification facility using sulfuric acid. Catalyst regeneration process using sulfuric acid showed the recovery of the activity of waste catalyst over 80% comparison with new catalyst, and we optimized operating condition through control sulfuric acid concentration and regeneration time. The activity recovery ratio of waste catalyst was revealed at 0.5 M sulfuric acid in regeneration solution, but for the case of higher than 2.5 M of H2SO4 concentration, activity recovery high hest ratio was decreased owing to the elution of active compounds from the catalyst surface. The eluted active compounds were increased for the case of longer regeneration time and higher sulfuric acid concentration. Sulfuric acid concentration and regeneration time were main operating factors in regeneration of waste catalyst. But, the conditions of waste catalyst are affected by the boiler and SCR operating conditions and preliminary tests are needed to check the waste catalyst and decide the regeneration method and process.
        1667.
        2012.10 서비스 종료(열람 제한)
        본 연구는 대상자의 수가 적고 대조군이 없어 연구결과를 일반화시키기에 제한점이 있으나, 연구결과에서 원예치료 프로그램이 청소년의 자아 존중감과 학교생활적응에 미치는 영향을 검증한 결과 통계적으로 유의한 차이가 나타났다. 이러한 원예치료 프로그램을 대상자와 함께 하는 동안 그들의 변화하는 모습에서 프로그램 실시 전에 비해 프로그램 실시 후 청소년들의 자아존중감과 학교생활적응에 원예치료가 많은 영향력을 미친다는 사실을 알 수 있었다. 그리고 다양한 식물과 재료를 사용하여 새로운 것에 대하여 경험해보게 하고 새로운 방법을 시도해 볼 수 있도록 하여 청소년들의 건강한 성장과 발달을 위하여 다양한 원예치료 프로그램 개발이 필요하다고 사료된다.
        1668.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        Ground seawater quality was investigated, and the algal growth potential (AGP) tests were performed along the Tongyeong coast to examine the inflow of materials, which is needed for the red tide species Cochlodinium polykrikoides to grow. The study was conducted to determine the mechanism for C. polykrikoidesred tides. Water temperature, salinity, pH, and dissolved oxygen (DO) ranged from 16.05 to 20.74°C, 18.20 to 32.11 psu, 6.00 to 7.61, and 3.41 to 7.91 mg/L (41.4– 96.1%), respectively. No seasonal variation was observed in water temperature. The salinity, pH, and DO saturations at most stations were lower than those of coastal seawater at Tongyeong. The NH4 +-N, NO2+3 --N, PO4 3--P concentrations ranged from 0.43 to 16.00μM, 1.50 to 132.38μM, and 1.30 to 6.29μM, respectively; the values at some stations were much higher than observed in Tongyeong coast seawater. Using seawater from station B, C. polykrikoides grew consistently, with a high growth rate, similar to the red tide in nature. This seawater appeared to contain materials needed by C. polykrikoides to grow. Therefore, C. polykrikoides red tides seem to occur wherever the ground sea water contains materials that are needed for its growth.
        1669.
        2012.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        To evaluate the effect of aging on solar salts produced in Korea, the chemical compositions of the solar salts, including their heavy metal contents, were analyzed after they were aged for one-year (OA) and for three years (TA). The average contents of the components were: sodium chloride; 81.4% (OA) and 90.9% (TA), chloride; 57.7% (OA) and 65.0% (TA), moisture content; 4.7% (TA) and 12.0% (OA), insoluble solids; 0.03% (OA) and 0.04% (TA), and SO4 ions; and 0.57% (TA) and 0.85% (OA). No significant difference was found, however, in the heavy metal contents. Heavy metals such as As, Pb, and Hg were detected with values far below the maximum permissible limit, and Cd was not detected in the salts. The TA solar salts showed higher values of sodium chloride, chloride, and insoluble solids than the OA solar salts, but the TA solar salts had lower moisture and SO4 values. These results clearly indicate that the levels of heavy metals in the OA and TA solar salts that are produced in Korea are safe.
        1670.
        2012.07 서비스 종료(열람 제한)
        2004년도부터 저온 암꽃 발생이 양호한 모계친 원형수박인 KC계통을 모본으로 하고, 부계는 노란색 과피의 비대가 빠른 HB.Y계통을 선발하여 조합을 작성하였다. 이중 2008년도와 2009년도에 2년간 조합작성 및 조합능력을 검정한 결과 한 개의 조합을 선발하였다. 2009년 가을파종에 선발된 조합을 시교생산을 하여 2010년도에 생산력검정 및 차대검정을 하였던바 균일성 및 생산성이 좋아 새로운 품종으로 충분한 가치가 있다고 판단되어 “조생노란꿀수박”으로 명명 하였다. “조생노란꿀수박” 품종의 특성으로는 과의 형태는 단타원형의 중대과종이고, 황색의 외피에 과육색은 연한 빨강색이며 당도가 매우 높다. 생육초기에는 잎이 연한 녹색이나 착과 후에는 노란색으로 변한다. 저온에서 암꽃 발생이 좋으며 과의 비대가 좋다.
        1671.
        2012.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        To prepare calcium-binding peptides as calcium supplement, barley proteins were hydrolyzed using Flavourzyme for 18 h and the hydrolysates were ultra-filtered under 3 kDa as a molecular weight. The resultant filtered peptides were fractionated using ion exchange and normal-phase high performance liquid chromatography. Then each fraction that was obtained was determined for its calcium-binding activity to isolate the calcium-binding peptides. As a result, the highest calcium-binding peptide fraction was obtained, and the results suggest that barley protein hydrolysates can be used as a calcium supplement.
        1673.
        2012.05 서비스 종료(열람 제한)
        This paper presents the development of LRFD codes for axially-loaded driven piles in sands. Reliability analyses were performed using the AFOSM and finally, reasonable resistance factors of base and shaft resistances were calculated base on the results of reliability analyses for different target reliability index levels. From the results of extensible reliability analyses using AFOSM, resistance factors for base and shaft resistances were found to be highly dependent on the ratios of dead-to-live load and ultimate base resistance to limit shaft resistance. Resistance factors are proposed for different combinations of these ratios within their possible ranges.
        1674.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        The feature of asthma are airway inflammation (AI), reversible airway obstruction, and an increased sensitivity to bronchoconstricting agents, elevated airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. This study was performed to investigate if oral administration of Scutellaria baicalensis Georgi water extracts (SBG) have the antiasthmatic potential for the treatment of asthma. Asthmatic HI and AHR were induced by systemic sensitization to ovalbumin (OVA) with intratracheal instillation with 0.1 mg/mL of diesel exhaust particles (DEP) suspension once a week for 10 weeks in BALB/c mice. SBG was orally administered with the concentraion of 200 mg/kg 5 days a week for 10 weeks. Long-term SBG treatment suppressed the eosinophil infiltration into airways from blood, the asthmatic AI and AHR by attenuating the production of cytokine IL-4, IL-5 and IL-13, histamine and OVA-specific IgE. Our data suggest that SBG has inhibitory effects on AI and AHR in a mouse model of asthma, may act as a potential Th2 cytokine antagonist, and may have a therapeutic effect on allergic asthma.
        1675.
        2012.03 KCI 등재 서비스 종료(열람 제한)
        약용식물은 피부와 모발을 보호하는 잠재적 기능을 가지고 있다고 알려져 있다. 수용성 호스트 β-cyclodextrin 과 약용식물의 기능성 성분들과의 복합체 형성 시 나타나는 피부와 모발에 미치는 효과에 대하여 조사하였다. 기존의 연구에서 복합체 형성물의 무독성, 그리고 그람양성균과 비듬을 발생시키는 곰팡이에 대한 항균기능성을 확인하였다.본 연구에서는 약용식물의 기능성 성분을 함유한 크림이 피부의 콜라젠 생성을 유도하여 피부의 생리활성을 증대시킴을 확인하였다. 또한 기능성 성분을 함유한 헤어토닉 처리군에서 육모의 성장이 증진되었음을 생쥐를 이용한 동물실험에서 확인하였다. 본 연구 결과, 비수용성 약용성분을 수용성 β-cyclodextrin에 포접시켜 초분자 복합체 형성을 통해, 육모기능의 향상과 피부노화지연 등 부가적 화장제재로의 개발가능성을 보여주었다.
        1676.
        2012.02 서비스 종료(열람 제한)
        우리나라에는 태풍, 호우, 폭풍 등 자연재난에 의한 피해가 자주 발생하는데, 대부분 물과 관련된 기상재난의 성격을 갖는다. 이 같은 자연재난은 인구 증가와 도시화 현상으로 도시외곽 저지대의 증가, 경사지 토지 이용도 증가, 홍수조절 구조물과 시설의 빈약성, 각종 개발사업의 영향 등으로 그 피해가 점점 증가하고 있는 실정이다. 본 연구에서는 홍수 예·경보체계 및 기타 상황전파체계의 시사점을 검토하고 위험지역의 예·경보 발령 시 효율적인 대피체계를 수립하고자 한다. 재해정보지도 작성 시에는 현장 확인을 통하여 지도의 효율성과 품질을 높였고, 대피 장소는 대피대상지역에서 가능한 도보로 이동이 가능한 장소를 지정하는 것을 원칙으로 하였다. 재난 발생 시 현 대피 경로 구축을 위한 작성 지침을 조사하고, 실제 피난활용형 재해지도 작성을 위한 대피경로 구축과정을 통하여 개선방안을 도출하였다.
        1677.
        2012.02 서비스 종료(열람 제한)
        우리나라는 화산재해의 안전지대로 여겨졌으나 최근 백두산의 분화 가능성이 고조됨에 따라 백두산 분화 전조 및 분화 시나리오, 화산재 확산 연구 등이 발표되고 있으며, 이에 대한 대응 수립 방안이 논의되고 있다. 본 연구는 국내 대기 환경관리 기준 제시와 방향을 설정하기 위한 기초연구로 백두산 화산재 성분 조사와 화산재 성분의 위험성을 평가하였고, 국내외 대기관리 기준을 비교·분석하였다. 추가적으로 백두산 분화시 화산재의 확산 범위와 거리별 확산 농도, 이동 중 성분변화 등의 연구가 진행된다면, 화산재 피해에 대응할 수 있는 지역별 대기 관리 기준이 수립될 수 있을 것으로 판단된다.
        1678.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 소형 선박용 관성측정장치(Inertial Measurement Unit, IMU) 개발에 적합한 MEMS(Micro-Electro Mechanical System) 기반의 관성 센서 평가와 선정에 관하여 기술했다. 먼저, 오일러 공식에 기초한 관성 센서의 오차 모델과 잡음 모델을 정의하고, 앨런 분산(Allan Variance) 기법과 몬테카르로(Monte Carlo) 시뮬레이션 기법을 도입하여 관성 센서를 평가하였다. ADIS16405, SAR10Z, SAR100Grade100, LIS344ALH, ADXL103 등 다섯 가지 관성 센서에 대한 평가결과, ADIS16405의 자이로와 가속도계를 조합한 경우 오차가 가장 작게 나타났는데, 600 초 경과시 속도 오차의 표준편차가 약 160 m/s, 위치 오차의 표준편차가 약 35 km로 나타났다. 평가를 통해 ADIS16405 관성 센서가 IMU 구축에 최적임을 알았고, 이러한 오차 감소 방법에 대해서 참고문헌을 조사하여 검토하였다.
        1679.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        Conventional Thiamine Dilauryl Sulfate (TDS) powder has a low stability. In order to solve this problem, this study was performed to improve the solubility of TDS. The process for enhance solubility of TDS was nano grinding mill and ultrasonic dispersion process. TDS paticle was manufactured to nano size through nano grinding mill process. The size of TDS nanoparticle was measured as average 220 nm by DLS. And The TDS nanoparticle in water solution manufactured through ultrasonic dispersion process. The TDS nanoparticle in water solution was showed the highest solubility with 40% ethanol. These results was increased the concentration of TDS from 200 ppm to 240 ppm in water solution. The TDS nanoparticle in water solution showed diameter of Colletotrichum gloeosporioides growth with smaller than about 1.56 cm compared to the TDS paticle in water solution at same concentration. Also, TDS nanoparticle in water solution showed growth inhibition activity as 59.2% with higher than about 10% compared to the TDS paticle water solution in same concentration. Finally, TDS nanoparticle in water solution was increased solubility through nano grinding mill and ultrasonic dispersion process. Also, the increase of concentration in TDS nanopaticle in water solution according to solubility enhancement lead to an result enhancement of antifungal activity. Consequently, we suggested that the TDS nanoparticle in water solution was more effective than TDS particle in water solution owing to the sub-cellular particle size, ability to persistence and targeting to cell membrane of Colletotrichum gloeosporioides. Furthermore we expected the applicating possibility with bio pesticide.
        1680.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        The present study examined the effects of Korean white ginseng (WG, Panax ginseng C. A. Meyer) on the learning and memory function and the neural activity in rats with trimethyltin (TMT)-induced memory deficits. The rats were administered with saline or WG (WG 100 or 300 mg/kg, p.o.) daily for 21 days. The cognitive improving efficacy of WG on the amnesic rats, which was induced by TMT, was investigated by assessing the Morris water maze test and by performing immunohistochemistries on choline acetyltransferase (ChAT), acetylcholinesterase (AchE), cAMP responsive element binding protein (CREB) and brain derived neurotrophic factor (BDNF). The rats treated with TMT injection (control group) showed impaired learning and memory of the tasks, but the rats treated with TMT injection and WG administration produced significant improvement of the escape latency to find the platform in the Morris water maze at the 2nd and 4th days compared to that of the control group. In the retention test, the WG 100 and WG 300 groups showed significantly increased crossing number around the platform compared to that of the control group (p < 0.001). Consistently with the behavioral data, result of immunohistochemistry analysis showed that WG 100 mg/kg significantly alleviated the loss of BDNF-ir neurons in the hippocampus compared to that of the control group (p < 0.01). Also, treatment with WG has a trend to be increased the cholinergic neurons in the hippocampal CA1 and CA3 areas as compared to that of the control group. These results suggest that WG may be useful for improving the cognitive function via regulation of neurotrophic activity.