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        검색결과 120

        101.
        1983.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        정면규칙파중에서 Bow-flare부 충격은 선저충격에 비해서 작용 시간이 길고, 선체 수직운동진폭이 큰 상태이거나, 파고가 큰 입사파가 적용되는 경우에 선체에 작용하는 충격력은 상당히 크며, 파고가 높아지면, 발생하는 모우멘트도 증가한다. 2. Bow-flare부가 큰 선형의 경우에는 선저노출이 일어나지 않더라도 부가질량의 급격한 증가에 따라 상당히 큰 충격력이 작용한다. 3. Deckwetness, 불규칙파중에서의 응답해석, 상대변위를 구할 때 Dynamic Swell-up의 양을 고려한 계산 등의 검토가 요망된다.
        4,000원
        102.
        2020.06 KCI 등재 서비스 종료(열람 제한)
        북극해 관련 정부정책의 경우 해양수산부에서 제시된 “북극활동 진흥 기본계획”이 있으나, 구체적인 정책 집행의 순위 및 가중치 등 이 제시되어 있지 않아 정책집행의 시기조절 및 경중을 고려하기에 어려움이 있다. 이러한 측면에서 본 연구에서는 정부에서 제시한 북극정 책의 우선순위를 평가하는 것을 연구의 목적으로 하였다. 또한 북극정책의 원활한 수행을 위한 “지원방안” 및 “대외협력 방안”에 대해서도 우 선순위를 제시하였다. 연구의 방법론은 전문가 의견을 종합적으로 평가할 수 있는 CFPR(Consistent Fuzzy Preference Relations) 방법을 활 용하였다. 분석결과 해양수산부의 가장 중요한 북극정책은 ‘북극항로 개척 등 해운물류 협력’(0.087)이며, ‘전문인력 양성’(0.086), ‘제도적 기반 및 청사진 마련’(0.085) 순으로 나타났다. 본 연구의 결과는 북극해 관련 정책입안자 혹은 당국의 정책수립에 시사점을 제공할 수 있다.
        103.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        The concepts of residence time and flushing time can be used to explain the exchange and transport of water or materials in a coastal sea. The application of these transport time scales are widespread in biological, hydrological, and geochemical studies. The water quality of the system crucially depends on the residence time and flushing time of a particle in the system. In this study, the residence and flushing time in Gamak Bay were calculated using the numerical model, EFDC, which includes a particle tracking module. The average residence time was 55 days in the inner bay, and the flushing time for Gamak Bay was about 44.8 days, according to the simulation. This means that it takes about 2 months for land and aquaculture generated particles to be transported out of Gamak Bay, which can lead to substances accumulating in the bay. These results show the relationships between the transport time scale and physical the properties of the embayment. The findings of this study will improves understanding of the water and material transport processes in Gamak Bay and will be important when assessing the potential impact of coastal development on water quality conditions.
        106.
        2011.07 KCI 등재 서비스 종료(열람 제한)
        A ecosystem model was applied for understanding of circulation process of state variables in marine ecosystem. A mass balance was conducted by calculating the physical process. The sensitivity analysis was conducted to know which coefficient is the most effective factor to the state variables in the model. The results of the mass balance indicate that the primary production was 58.6 ton C/day in the case of mass flux. DIN and DIP in nutrient ingestion of phytoplankton were each 7.9 ton N/day, 1.1 ton P/day. POC and DOC in mineralization of organic matter were each 10.8 ton C/day, 40.6 ton C/day. The results of sensitivity analysis showed that the maximum growth rate of phytoplankton was the most important factor for overall state variables. In the case of nutrients, Half saturation constant of DIN, and mineralization rate of DOM for COD were important factor.
        107.
        2011.04 KCI 등재 서비스 종료(열람 제한)
        A three-dimensional ecological model(EMT-3D) was applied to DAS1 in Tokyo Bay. The simulated results of DAS1 were in good agreement with the observed values. The result of sensitivity analysis showed that photolysis coefficient and extinction coefficient were important factor for dissolved DAS1, and photolysis coefficient, extinction and POC partition coefficient for PAHs in particulate organic matter. Mass balance of DAS1 in Tokyo Bay was calculated by using the simulated results of EMT-3D.
        108.
        2011.03 KCI 등재 서비스 종료(열람 제한)
        여드름 나노화장품(nanocosmetics) 개발을 위하여 azelaic acid-milk nano powder의 nanoencapsulation을 fluid-bed processor로 중심합성계획에 따라 유입공기온도(60 ~ 80 ℃), 분무속도(0.5 ~ 0.9 mL/min) 및 분무압력(1.2 ~ 2.0 kg/cm2)을 달리하여 나노캡슐(nanoencapsule)을 제조하고, 나노캡슐의 품질특성을 조사하여 회귀분석을 실시하였다. 나노캡슐의 예측된 수율의 최대값은 70.97 %로 수율은 유입공기온도, 분무속도 및 분무압력 에 의해 크게 영향을 받고 있었다. 시료의 입자 크기는 유입공기온도가 높고 분무속도가 빠르며, 분무압력이 낮을수록 커지는 것으로 나타났고, 생리식염수에서 나노캡슐의 용출율은 모두 유입공기온도 및 분무속도에 의해서 가장 많은 영향을 받고 있었다. 수분함량은 분무 속도가 증가하고 분무압력이 높아질수록 증가하였고, 수분활성도는 수분함량과 유사한 경향을 나타내었다. 기계적 색도인 L값과 b값은 유입공기온도가 높아질수록 증가하였다. 수율이 높고 입자크기가 작으며, 피부적합성 나노캡슐 제조의 최적조건은 유입공기온도 67 ~ 73 ℃, 분무속도 0.6 ~ 0.8 mL/min 및 분무압력 1.8 ~ 2.0 kg/cm2 범위로 예측되었다. 이상의 예측범위 내의 임의의 점에서 실제 실험한 실험치는 반응표면분석법에 의해 예측된 값과 유사한 경향을 보여 도출된 회귀식의 신뢰성을 검증할 수 있었다.
        109.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        To find proper water quality management strategy for oxygen consumption organic matters in Jinhae bay, the physical process and net supply/decomposition in terms of COD was estimated by three-dimensional eco-hydrodynamic modeling. The estimation results of physical process in terms of COD showed that transportation of COD was dominant in loading area from land to sea, while accumulation of COD was dominant in middle~bottom level. In case of surface level, the net supply rate of COD was 0~60 mg/m2/day. The net decomposition rate of COD was 0~-0.05 mg/m2/day(-5~-10 m, in depth) to 2 level, and -0.05~-0.20 mg/m2/day(10 m ~) to bottom level. These results indicate that the biological decomposition and physical accumulation of COD are occurred for the most part of Jinhae Bay bottom. The variation of net supply or net decomposition rate of COD as reducing land based input loading is also remarkable. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters to improve the water quality of Jinhae Bay.
        110.
        2007.08 KCI 등재 서비스 종료(열람 제한)
        The three-dimensional eco-hydrodynamic model was applied to estimate the autochthonous COD caused by production of phytoplankton in Jinhae Bay. A residual current was simulated, using a hydrodynamic model, to have a sightly complicated pattern in the inner part of the bay, ranging from 0.001 to 5 cm/s. In the outer part of the bay, the simulated current flowed out to the south sea with a southward flow at a maximum of 25 cm/s. The results of the ecological model simulation of COD levels showed high concentrations, exceeding 4 mg/L, in the inner bay of Masan, an area of wastewater discharge, and lower levels, approaching less than 1 mg/L, closer to the outer part of the bay. The simulation results of Autochthonous COD by two methods using ecological modeling, showed high ratio over 70% of total COD. Therefore, it is more important to consider nutrients than organic matters in the region for control COD standard.
        111.
        2005.09 KCI 등재 서비스 종료(열람 제한)
        The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0~0.50 mg/m2/day. The net decomposition rate of COD was 0~0.04 mg/m2/day in middle level(3~6m) and 0.05~0.15 mg/m2/day in bottom level(6m~bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.
        112.
        2005.09 KCI 등재 서비스 종료(열람 제한)
        A three-dimensional ecological model (EMT-3D) was applied to Nonylphenol in Tokyo Bay. EMT-3D was calibrated with data obtained in the study area. The simulated results of dissolved Nonylphenol were in good agreement with the observed values, with a correlation coefficient(R) of 0.7707 and a coefficient of determination (R2) of 0.5940. The results of sensitivity analysis showed that biodegradation rate and bioconcentration factor are most important factors for dissolved Nonylphenol and Nonylphenol in phytoplankton, respectively. In the case of Nonylphenol in particulate organic carbon, biodegradation rate and partition coefficient were important factors. Therefore, the parameters must be carefully considered in the modeling. The mass balance results showed that standing stocks of Nonylphenol in water, in particulate organic carbon and in phytoplankton are 8.60×105 g, 2.19×102 g and 3.78×100 g, respectively. With respect to the flux of dissolved Nonylphenol, biodegradation in the water column, effluent to the open sea and partition to particulate organic carbon were 6.02×103 g/day, 6.02×102 g/day and 1.02×101 g/ day, respectively.
        113.
        2003.07 KCI 등재 서비스 종료(열람 제한)
        The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of nutrients and net uptake(or regeneration) rate of nutrients in Kamak Bay for scenario analysis to find proper management plan. The estimation results of the physical process in terms of nutrients showed that transportation of nutrients is dominant in surface level while accumulation of nutrients is dominant in bottom level. In the case of dissolved inorganic nitrogen, the results showed that the net uptake rate was 0~60 mg/m2/day in surface level(0~3m), and the net regeneration rate was 0.0~10.0 mg/m2/day in middle level(3~6m) and above 10 mg/m2/day in bottom level(6m~below). In the case of dissolved inorganic phosphorus, the net uptake rate was 0.0~3.0 mg/m2/day in surface level, and the net regeneration rate was 0.5~1.5 mg/m2/day in middle level and 1.0~3.0 mg/m2/day in bottom level. These results indicates that net uptake and transport of nutrients are occurred predominantly at the surface level and the net generation and accumulation are dominant at bottom level. Therefore, it is important to consider the re-supplement of nutrients due to regeneration of bottom water.
        114.
        2002.09 KCI 등재 서비스 종료(열람 제한)
        씀바귀 뿌리 추출물 및 분획물에 대한 DPPH free radical 소거법에 의한 항산화활성을 검색한 결과 에칠아세테이트 분획물(RC50=12μg/ml)이 대조구인 BHA(RC50=14μg/ml)나 α-tocopherol(RC50=12μg/ml)과 유사한 활성을 나타내었다. 항미생물 활성을 측정한 결과 곰팡이 균주에 대해서는 물 분획물이 대체적으로 우수한 활성을 나타내었다. Hypocrea nigricans에서는 대조구인 Cyclohexamide(13μg/ml)보다 우수한 활성(8μg/ml)을 나타냈으며, Cladosporium herbarum에서는 부탄올 분획물(8μg/ml)과 메탄올 추출물(16μg/ml)에서 대조구(25μg/ml)보다 우수한 활성을 나타내었다. 반면에 세균 균주중 Bacillus subtilis 균주에 대해서는 물층 분획물(32μg/ml)과 에칠아세테이트 분획물(125μg/ml)이 우수하였으며, Candida lypolytica 균주에 대해서는 핵산 분획물 (32μg/ml)과 물충 분획물(63μg/ml)이 우수하였고, Escherichia coli 균주에 대해서는 에칠아세테이트 분획물(125μg/ml)과 메탄올 추출물(250μg/ml)이 우수한 활성을 나타내었다. 돌연변이원성 억제작용을 검토하기 위하여 Ames test 에서 양성반응을 나타내며, 물질 그 자체로서 돌연변이를 유발하는 직접 변이원물질로 MNNG와 4NQO 그리고 대사활성을 필요로 하는 간접 변이원 물질인 B(a)P을 사용하여 각각의 농도에 따른 돌연변이원성 억제활성 결과 MNNG(0.4μg/plate)의 경우 S. typhimurium TA100 균주에서 시료농도 (100μg/plate)에서 메탄올 추출물이 79.94%로 가장 높은 억제효과가 나타났다 4NQO(0.15μg/plate)에 대한 S. typhimurium TA98 균주에서 메탄올 추출물이 89.99%로 가장 높은 억제효과를 나타냈으며, TA100 균주의 경우에서도 메탄올 추출물에서 84.56% 로 가장 높은 억제 효과를 나타내었다. B(a)P(10μg/plate)에서는 TA98 균주에서 (100μg/plate)의 시료농도에서는 부탄올 분획물이 89.92%로 가장 높은 억제효과를 보였으며 TA100 균주에서는 메탄올 추출물이 77.47%로 가장 높은 억제효과를 나타내었다. 암세포주(A549, Hep3B, MCF-7)에 대한 씀바귀 뿌리추출물의 세포독성을 알아보기 위하여 실험한 결과, 페암세포주인 A549세포에서는 에칠아세테이트 분획물(250μg/ml)이 91.67%로 가장 높은 억제효과를 나타내었고, 간암세포주인 Hep3B에서는 에칠아세테이트 분획물 (500μg/ml)이 75.01%로 가장 높은 억제효과를 나타냈으며, 유방암 세포주인 MCF-7에서도 에칠아세테이트 분획물(500μg/ml)이 84%로 가장 높은 억제효과를 보였다. 정상 간세포주인 293에 대하여 시료농도에 따른 세포독성 효과를 나타낸 것으로 (500μg/ml) 시료 첨가시 암세포에 대하여 대부분 50% 전후(물 분획물 제외)의 억제율을 보이는데 반해 293세포에 대해서는 29% 이하의 생육억제율을 보였다. 이는 암세포주에 대한 높은 억제효과에 비해 정상세포에 대해서는 비교적 낮은 독성효과를 나타냄을 알 수 있었다.
        115.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        각 균주에 대하여 씀바귀 분말 시료들이 독성을 나타내지 않는 범위에서 강력한 발암물질로써 직접 변이원으로 사용된 MNNG(0.4μg/plate)의 경우 S. typhymurium TA100 균주에서 시료농도 100μg/plate에서 메탄올 추출물이 84.51%로 가장 높은 억제효과가 나타났으며, 4NQO(0.15μg/plate)에 대한 S. typhymurium TA98 균주에서 시료농도 100μg/plate에서는 물 분획물이 86.73%로 가장 높은 억제효과를 나타내었다 또한, TA100균주의 경우에는 부탄올 분획물에서 88.93%로 가장 높은 억제효과를 나타내었다. 간접변이원인 B(a)P를 사용한 실험에서 TA98 균주에서는 메탄올 추출물이 86.98%로 가장 높은 억제효과를 보였으며, TA100 균주에서는 부탄올 분획물이 75.35%로 가장 높은 억제효과를 나타냈다. 암세포주(A549, Hep3B, MCF-7)에 대한 씀바귀 분말의 증식 억제효과를 알아보기 위하여 실험한 결과, 폐암세포주인 A549세포에서는 핵산 분획물(500μg/ml)이 87.91%로 가장 높은 억제효과를 나타내었으며, 간암 세포주인 Hep3B 에서는 핵산 분획물(375μg/ml)이 70.64%로 가장 높은 억제효과를 나타냈다. 유방암 세포주인 MCF-7에서도 핵산 분획물(375μg/ml)이 82.89%로 가장 높은 억제효과를 보였으며, 인간 정상 간세포 293에 대해서는 24% 이하의 생육억제율을 보였다. 이는 암세포주에 대한 높은 억제효과에 비해 정상세포에 대해서는 비교적 낮은 증식 억제효과를 나타냄을 알 수 있었다.
        119.
        2000.10 KCI 등재 서비스 종료(열람 제한)
        It is very important to interprete and simulate the variation of phytoplankton maximum region for the prediction and control of red tide. This study was composed of two parts, first, the hydrodynamic simulation such as residual current and salinity diffusion, and second, the ecological simulation such as phytoplankton distribution according to freshwater discharge and pollutant loads. Without the Nakdong river discharge, residual current was stagnated in inner side of this estuary, and surface distribution of salinity was over 25psu. On the contrary, with summer mean discharge, freshwater stretched very far outward and some waters flowed into Chinhae Bay through the Kadok channel, and low salinity extended over coastal sea and salinity front occurred. From the result of contributed physical process to phytoplankton biomass, the accumulation was occurred at the west part of this estuary and the Kadok channel with the Nakdong river discharge. When more increased input discharge, the accumulation band was transported to outer side of this estuary. The frequently outbreak of red tide in this area is caused by accumulation of physical processes. The phytoplankton maximum region located inner side of this estuary without the Nakdong river discharge and with mean discharge of winter, but it was moved to outer side when mean discharge of the Nakdong river was increased. The variation of input concentration from the land loads was not largely influenced on phytoplankton biomass and location of maximum region. When discharge was increased, phytoplankton maximum region was transferred to inner side of the Kadok channel. On the other hand, when discharge was decreased, phytoplankton maximum region was transferred to inner side of this estuary and chlorophyll a contents increased to over 20㎍/L. Therefore, if any other conditions are favorable for growth of phytoplankton, decrease of discharge causes to increase of possibility of red tide outbreak.
        120.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        It is noted that the red tides and the oxygen-deficient water mass are extensively developed in Masan Bay during summer. The nutrients mass balance was calculated in Masan Bay, using the three-dimensional numerical hydrodynamic model and the material cycle model. The material cycle model was calibrated with the data obtained on the field of the study area in June 1993. The nutrients mass balance calculated by the combination of the residual currents and material cycle model results showed nutrients of surface and middle levels to be transported from the inner part to the outer part of Masan Bay, and nutrients of bottom level to be transported from outer part to inner part of Masan Bay. The uptake rate of DIN in the box A1(surface level of inner part) was found to be 337.5㎎/㎥ ·day, the largest value in all 9 boxes and that of DIP was found to be 18.6㎎/㎥·day in box A1, and the regeneration rate of DIN was found to be 78.2㎎/㎥· day in the box A3(bottom level of inner part), and that of DIP was found to be 18.6㎎/㎥· day in box A1. The regenerations of DIN and DIP in the water column of the entire Bay were found to be 7.66ton/day and 760㎏/day, respectively. And the releases of DIN and DIP from the sediments of the entire Bay were found to be 2.86ton/day and 634㎏/ day, respectively. The regeneration rate was 2.5 times as high as the release rate in DIN, and 1.2 times in DIP. The results of mass balance calculation showed not only the nutrients released from the sediments but the nutrients regenerated in water column to be important in the control and management of water quality in Masan Bay.
        6