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        검색결과 161

        141.
        2011.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        캠벨' 포도주스의 이화학적 및 관능적 품질특성에 저온 안정화 처리기간이 미치는 영향을 조사하기 위하여, 포도 과실로 압착 주스를 제조하여 에서 30일간 보관하면서 주스의 각종 품질특성 변화를 조사하였다. 주스의 당/산비와 pH는 증가하였으나 적정산도와 가용성 고형분 함량은 경시적으로 감소함을 보였다. 주스의 명도( 값)와 황색도( 값)는 증가하는 경향을 보였으며 적색도( 값)는 감소하는 경향을 각각 나타내었다. 주스의 총페놀, 안토시아닌, 플라보
        142.
        2011.04 KCI 등재 서비스 종료(열람 제한)
        본 연구는 선박용 Night Vision 시스템을 개발하기 위한 선행연구로 2축 지그와 이를 구동할 수 있는 PCU 보드를 제작하고, 추종 및 안정화 제어루틴을 얻는 문제를 다룬다. 개발한 지그와 PCU 보드를 6DOF 모션 시뮬레이터와 결합하여 실험환경을 구축하고 RCGA를 이용하여 지그 모델의 파라미터를 얻고, 추정된 모델과 RCGA를 이용하여 2DOF PID 제어기를 동조한다. 실험과 시뮬레이션을 통해 제안하는 2자유도 PID 제어기의 유효성을 검토한다.
        143.
        2010.11 KCI 등재 서비스 종료(열람 제한)
        This paper proposes a robust image stabilization system for a mobile robot using an Extended Kalman Filter (EKF). Though image information is one of the most efficient data used for robot navigation, it is subjected to noise which is the result of internal vibration as well as external factors such as uneven terrain, stairs, or marshy surfaces. The camera vibration deteriorates the image resolution by destroying the image sharpness, which seriously prevents mobile robots from recognizing their environment for navigation. In this paper, an inclinometer was used to measure the vibration angle of the camera system mounted on the robot to obtain a reliable image by compensating for the angle of the camera vibration. In addition the angle prediction obtained by using the EKF enhances the image response analysis for real time performance. The experimental results show the effectiveness of the proposed system used to compensate for the blurring of the images.
        144.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        In this paper, we propose a digital image stabilization technique using edge detection and Lucas-Kanade optical flow in order to minimize the motion of the shaken image. The accuracy of motion estimation based on block matching technique depends on the size of search window, which results in long calculation time. Therefore it is not applicable to real-time system. In addition, since the size of vector depends on that of block, it is difficult to estimate the motion which is bigger than the block size. The proposed method extracts the trust region using edge detection, to estimate the motion of some critical points in trust region based on Lucas-Kanade optical flow algorithm. The experimental results show that the proposed method stabilizes the shaking of motion image effectively in real time.
        145.
        2010.03 KCI 등재 서비스 종료(열람 제한)
        본 총설에서는 나노미터 크기의 고체 입자가 오일-물 계면에 흡착됨으로써 안정화된 에멀젼의 제조와 성질에 대하여 기술하였다. 이렇게 제조된 에멀젼을 Pickering 에멀젼이라 하며 이 에멀젼을 계면활성제로 안정화된 일반적인 에멀젼과 비교하였다. Pickering 에멀젼의 독특한 성질은 입자의 계면 흡착 에너지가 큰 점에 기인하며 일반 에멀젼과 주요한 차이점은 고체 입자가 비가역적으로 계면에 흡착한다는 사실이다. Pickering 에멀젼의 전상은 w/o (waterin-oil) 타입에서 o/w (oil-in-water)로 수상의 분율이 증가함에 따라 발생한다. 친수성의 입자는 o/w 에멀젼을 형성하는 경향을 보이고 친유성 입자는 w/o 에멀젼을 형성하는 경향을 보이며 이는 고체 입자의 오일-물 계면에서의 접촉각에 따른다. Pickering 에멀젼의 안정성은 많은 부분에서 일반적인 에멀젼과는 다른 거동을 보였다. 저자는 또한 Pickering 에멀젼의 화장품 응용 가능성에 대해서도 논의하였다.
        146.
        2010.02 KCI 등재 서비스 종료(열람 제한)
        A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.
        147.
        2009.02 KCI 등재 서비스 종료(열람 제한)
        In this study, to stabilize the heavy metal in the contaminated soils, the column leaching test based on rainfall and pH value was performed by using coal mine drainage sludge(CMDS): which was generated during electrical purification of abandoned coal mine wastewater. Four types of testing column were used in this study. That were the CMDS and the heavy metal contaminated soils well mixed in 0 wt%, 1 wt%, 3 wt% and 3 wt% layered column. According to the investigation, when the influent pH was 5.5∼6.2, there were no heavy metal elution at all conditions, and when the influent pH was 3∼3.3, the order of Cu, Zn, Pb, Cr elution concentration was 3 wt% M(mixed)<3 wt% S(separation)<1 wt% M<0 wt% and the average elution concentration was quite low, the value was 0.005 mg/L. Therefore, CMDS can used as new stabilizer of the heavy metal in the contaminated soils.
        148.
        2008.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        해양 녹조류인 청각에 함유되어 있는 chlorophyll을 유기용매를 사용하여 추출한 후 chlorophyll의 안정성을 증가시키기 위한 조건을 확립하였다. 추출 용매로 사용된 acetone, ethanol 그리고 methanol 중 methanol이 가장 효과적이었으며, 추출 수율은 건조 중량으로 이었다. TLC 및 HPLC 분석을 통하여 청각 색소에는 chlorophyll a 와 chlorophyll b가 주성분이며, 이들은 각각 0.40
        149.
        2007.08 KCI 등재 서비스 종료(열람 제한)
        컨테이너 화물의 복합운송시스템 중에서 체화현상은 항만에서 가장 심각하다. 이러한 문제를 해결하기 위해 해상과 육상의 경계선에서 체선체화 문제를 발생시키는 컨테이너 크레인의 직업효율을 향상시키는 방법을 생각할 수 있다. 이를 위해 본 연구에서는 가능한 범위에서 트롤리를 목표지점까지 빠르게 이동시키는 동시에 목표위치에서의 흔들림도 짧은 시간 내에 제어하는 문제를 다루고 있다. 제어 전략으로 설계된 구간에서 최적의 성능과 강인성이 보장되는 LQ 제어와 제약조건에서 최적화가 가능한 실수코딩 유전알고리즘을 결합한다. 컴퓨터 시뮬레이션을 통해 제안한 제어기가 설정한 설계사양을 완벽하게 만족하는 것을 보임으로 그 유효성을 증명한다.
        150.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        일반적으로 음이온 계면활성제는 효소의 disulfide bond를 분해시켜 효소의 활성이 없어진다. 따라서 특정한 캡슐에 효소를 포집하여 안정도를 증대시킨다. 본 연구에서는 polyethylene glycol (PEG), polypropylene glycol (PPG), 그리고 PEG- PPG-PEG block copolymer 등의 폴리올을 이용하여 papain 효소의 안정도를 증대시켰다. Energy dispersive spectroscopy (EDS)와 confocal laser scanning microscope (CLSM) 분석을 통하여 폴리올은 고분자층과 효소의 중간에 위치하며, 이들은 완충액으로 작용하여 효소의 안정도를 증대시키는 것으로 확인하였다. 또한, 이온 복합체를 이용하여 다층 캡슐을 제조하여 wash-off 형태의 세정제에 응용하였다. 세정제 내에서 계면활성제와 물은 효소캡슐의 표면에 분산되었으며, 캡슐의 중앙부분으로 서서히 침투되었다. 반면에 본 연구에서 사용된 sodium lauroyl sarcosinate와 polyguaternium-6는 물이 효소부분으로 침투하지 않는 것을 in vivo 시험을 통하여 확인하였다.
        155.
        2002 서비스 종료(열람 제한)
        Nowadays a fierce competition among the liner carriers and thus liner shipping market is characterized by chronic overtonnage and lower freight rates. So this paper's purpose is to analysis the determinant of liner freight rates and to seek for an effective policy and counter measures to stabilize liner freight market and rates. To achieve research purpose, on empirical and theoretical study was conducted. Survey questionnaire Objects are local ship operators and international freight forwarders in Korea And analysis method are reliability Test, factor analysis method for the variable choice and used the Structural Equation modeling(SEM) analyzing relationship determinant of freight rates with freight rates change & shipping company's decision & performance. As to Results of survey analysis. The best optimization strategy for both carriers and shippers in liner shipping business is to maintain a stable and adequate fright rate without its rapid fluctuation as per supply and demand in the market. To be concrete, it is essential for them to set up and effectively manage on international institute or association for the purpose of I) constant study and circulation of ships capacity us cargo movements, ii) strong recommendation of capacity adjustment.
        157.
        2001.02 KCI 등재 서비스 종료(열람 제한)
        HRP(high rate pond) which had kept the manufactured clay of 3㎝-thickness as benthic clay in reactor and the 6 flat-blade turbine as impeller for agitation was named HRASP(high rate algae stabilization pond). And the experiment for treatment of artificial synthesis wastewater containing COD : 300㎎/ℓ. , NH3-N : 30㎎/ℓ, T-P : 9㎎/ℓ. as nutrients was been performed successfully. This reactor was been operated under conditions : 24 hrs.-irradiation and water temperature, 25℃ and pH 7 and agitation velocity, 15, 30, 45rpm and the effect of agitation velocity on algal bioaccumulation of nutrients was been studied with view point of fluid dynamics. The next followings could be obtained as results. 1. The agitation with a turbine impeller blade in HRASP makes clay particle indicate superior suspension effect by means of forming of excellent curl/shear flow in reactor. 2. The excessive suspension of clay particle which is created at 45rpm as rotation velocity of impeller blade of turbine disturbs the light penetration and algal photosynthesis reaction. 3. Efficiencies for removal of nutrients come out as COD : 93.9%∼94.3%, (NH3-N + NO3-N) : 81.9%-99.0%, T-P : 46.8%-53.6%. 4. Kuo values of K1 for algal growth come out seperately as 15rpm : 1.876×10-2, 30rpm : 4.618×10-3. 5. Kuo values of K2 for removal of N, P come out seperately as 15rpm : 8.403×10-1 and 1.397×10-1, 30rpm : 4.823×10-1 and 2.052×10-1. 6. It can be guessed easily that the excessive agitation can inhibit the algal and bacterial symbiotic reaction if it is considered that micro organism' sense to preservation of life is relied on natural function of metabolism. Therefore the studies for this matter should be followed continuously.
        160.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        This research aims to seek active control of ball-beam position stability by resorting to neural networks whose layers are given bias weights. The controller consists of an LQR (linear quadratic regulator) controller and a neural networks controller in parallel. The latter is used to improve the responses of the established LQR control system, especially when controlling the system with nonlinear factors or modelling errors. For the learning of this control system, the feedback-error learning algorithm is utilized here. While the neural networks controller learns repetitive trajectories on line, feedback errors are back-propagated through neural networks. Convergence is made when the neural networks controller reversely learns and controls the plant. The goals of teaming are to expand the working range of the adaptive control system and to bridge errors owing to nonlinearity by adjusting parameters against the external disturbances and change of the nonlinear plant. The motion equation of the ball-beam system is derived from Newton's law. As the system is strongly nonlinear, lots of researchers have depended on classical systems to control it. Its applications of position control are seen in planes, ships, automobiles and so on. However, the research based on artificial control is quite recent. The current paper compares and analyzes simulation results by way of the LQR controller and the neural network controller in order to prove the efficiency of the neural networks control algorithm against any nonlinear system.
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