• Fisheries and Aquatic Sciences
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• 제8권3호
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• pp.177-181
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• 2005

Fishing selectivity is determined by the level of voluntary escaping behavior in accordance with decision-making based on the relationship between fish size and mesh size. This study examined movement during the swimming behavior of black porgy in a trawl's towing cod-end and analyzed the movement components such as swimming speed, angular velocity of turning, and distance to the net over time. Most of the observed fish exhibited an optomotor response, maintaining position and swimming speed without changing direction. Others exhibited erratic or 'panic' behavior with sudden changes in swimming speed and direction. The latter behavior involved very irregular and aperiodic variations in swimming speed and angular velocity, termed 'chaotic behavior.' Thus, the results of this study can be applied to a chaotic behavior model as a time series of swimming movements in the towing cod-end for the fishing selectivity.

• KSBB Journal
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• 제13권4호
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• pp.444-448
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• 1998

Biosorption of Pb and Cu was evaluated for 23 species of marine algae collected from a Korean coast. Among a variety of species for biosorbent potential, Hypnea charoides showed the highest capacity for Pb. An adsorption equilibrium was reached in about 2 hr for Pb and 30 min for Cu. The uptake capacity was 192.8 mg Pb/g biomass and 256 mg Cu/g biomass, respectively. The adsorption parameters for Pb and Cu were determined according to Langmuir model. With an increase in pH value, more negative sites are becoming avaliable for adsorption of pH and Cu, thus the removal of Pb and Cu increases at alkaline conditions. The selectivity of mixture solution shows the uptake order of Pb>Cu>Cr>Cd. When Ca concentration increases in Pb solution, Pb was selectively adsorbed.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.94.2-94.2
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• 2003

CJ-11668 is a new potent and selective COX-2 inhibitor. CJ-11668 showed COX-2 inhibition (IC50) of 65nM and selectivity ratio (COX-l/COX-2) of 770 in the cell based assay. In the human whole blood assay, CJ-11668 showed COX-2 inhibition (IC50) of 370nM and selectivity ratio (COX-l/COX-2), 135. The treatment of CJ-11668 (5 mg/kg, p.o) produced a significant inhibition (35%) of inflamed rat paw volume in the carrageenan-induced acute inflammation. CJ-11668 also suppressed the PGE2 level (69% inhibition, 1 mg/kg, p.o) in the zymosan-induced mouse air pouch model after 3 hrs. (omitted)

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3353-3358
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• 2007

The present paper is devoted to investigate dynamic effect and steady-state performance of methane autothermal reformer theoretically and numerically. In order to simplify the complicated phenomena in the system, axisymmetric heterogeneous reactor model is developed. As autothermal reaction takes places on catalyst surface between bulk gas and catalyst, volume averaging method is incorporated using porous medium approach. To understand the start-up process which occurs in the reactor is highly important. Therefore, in this paper we get various goverining equations to find out transient and steady solutions and time scale for start-up introducing dimensionless variables. Start-up is a significant issue in reforming reaction for automobile system and fueling of SOFC-based auxiliary power units. This paper deals with characteristics of heat and mass transfer and predicted light-off time in the reformer as oxygen to carbon ratio ($O_2$/C) and amount of feeding gas.

• Nuclear Engineering and Technology
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• 제44권7호
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• pp.767-772
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• 2012

In support of optimizing electrorefining technology for treating spent nuclear fuel, lithium drawdown has been investigated for separating actinides from molten salt electrolyte. Drawdown reaction selectivity is a major issue that requires investigation, since the goal is to remove actinides while leaving the fission products and other components in the salt. A series of lithium drawdown tests with surrogate fission product chlorides was run to obtain selectivity data with non-radioactive salts, develop a predictive model, and draw conclusions about the viability of using this process with actinide-loaded salt. Results of tests with CsCl, $LaCl_3$, $CeCl_3$, and $NdCl_3$ are reported here. Equilibrium was typically achieved in less than 10 hours of contact between lithium metal and molten salt under well-stirred conditions. Maintaining low oxygen and water impurity concentrations (<10 ppm) in the atmosphere was observed to be critical to minimize side reactions and maintain stable salt compositions. An equilibrium model has been formulated and fit to the experimental data. Good fits to the data were achieved. Based on analysis and results obtained to date, it is concluded that clean separation between minor actinides and lanthanides will be difficult to achieve using lithium drawdown.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.261-261
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• 2006

Membranes are a central feature of all biological systems and their ability to control many cellular processes is critically important. As a result, a better understanding of how molecules bind to biological membranes is an active area of research. In this report, the interaction between our biomimetic structures and different biological membranes is reported using both model vesicle and in vitro bacterial cell experiments. These results show that lipid composition is more important for selectivity than overall net charge. An effort is made to connect model vesicle studies with in vitro data and naturally occurring lipid compositions.

• 한국유통학회지:유통연구
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• 제11권3호
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• pp.103-125
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• 2006

본 연구에서는 최근 물류시스템과 통신매체의 급격한 발달로 인하여 보편화된 가정 내 쇼핑채널을 연구함에 있어서 새로운 접근방법이 필요함을 제시하고 있다. 가정 내 쇼핑채널 각각에 구매의도에 대한 영향요인을 검토하는 채널중심 연구는 가정 내 쇼핑채널이 보편화된 현재에는 큰 의미를 가지기 어렵다고 볼 수 있다. 본 연구에서는 고객중심 채널연구의 필요성을 제기하고 가정 내 쇼핑채널 이용비중과 이용다양성에 대한 고객특성과 쇼핑특성의 영향을 고객 중심적으로 검토하였다. 표본의 선택성을 고려하고 종속변수 간 인과관계를 모델에 반영하기 위하여 선택성을 가진 동시방정식 모델을 통하여 실증분석을 수행하였다. 연구결과 첫째로 가정 내 쇼핑채널 이용비중과 이용다양성은 서로 영향이 없는 것으로 나타나고 있으며, 둘째로 점포형 쇼핑채널 중에서 특히 백화점 이용이 증가할수록 가정 내 쇼핑채널 이용비중은 감소하는 것으로 나타나고 있으며, 셋째로 고객특성 및 쇼핑특성은 가정 내 쇼핑채널 이용다양성에 영향을 미치지 않는 것으로 나타나고 있다.

• 수산해양기술연구
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• 제50권3호
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• pp.351-360
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• 2014

The experiments were carried out to decide the selective fishing gear of the shrimp beam trawl fishery. The model nets were made of General type, Double-level type and Grid type. The model experiments were carried out to test opening efficiency and towing tension. The experimental tanks were the flume tank [$8.0L{\times}2.8W{\times}1.4H(m)$] and the towing tank [$85L{\times}10W{\times}3.5H(m)$] in National Fisheries Research and Development Institute. The full scale experiments were carried out to compare the selectivity of General type net, Double-level type net and Grid type net in the southern sea of korea. The vertical opening (net height) of the model nets can be expressed as a function of the towing velocity as the straight line. The towing tension of the model nets can be expressed as a function of the towing velocity as the parabola. The shrimp catching rates of upper cod end in Boryeong and tongyeong were 78%, 9% respectively, but the rates of lower cod end were 23%, 91% respectively. The number bycatch rates of General type and Grid type were 23%, 11% respectively, and the weight bycatch rates were 34%, 31% respectively. A selective shrimp beam trawl net is Grid type in korea coastal sea.

• 노동경제논집
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• 제26권1호
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• pp.23-52
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• 2003

본고는 청년층의 실업 및 비경제활동의 실태를 살펴보고 그 원인을 분석해 보았다. 청년층 비경제활동인구를 가사 육아 학업 훈련, 기타의 범주로 구분하고 선택편의 모형 및 다항로짓 모형으로 미취업자들의 시장가능임금 을 추정하고 실업 및 비경제활동의 선태 요인을 분석하였다. 분석의 결과 미취업자의 희망임금과 시장가능임금의 차이가 실업보다는 학업 훈련 범주나 기타의 범주에 속하는 비경제활동 청년에게서 크게 나타났다. 남성, 연령이 적을수록, 저학력일수록 희망임금과 시장가능임금의 차이가 크게 나타났다. 취업 및 실업, 비경제활동의 선택에서 남성, 고연령, 가구주, 자격증 소지자일 경우 취업의 선택 확률을 높이고 비경제활동의 선태 확률은 낮추는 것으로 나타났다. 청년층의 첫 직장 경험은 취업을 선택할 확률을 크게 낮추고, 실업 및 비경제활동을 선택할 확률을 높이는 것으로 나타났다. 이는 현재 청년층의 취업의 질이 극히 낮은 수준임을 반영하는 것이라 파악할수 있다.

• 멤브레인
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• 제17권1호
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• pp.14-22
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• 2007

본 연구는 투과증발법을 이용하여 수용액 중 미량의 목련 향 성분을 농축하는 방법으로, PVDF/PDMS 복합막을 제조하여 지지막의 구조와 활성층의 두께에 따른 분리능의 변화를 살펴보았다. PVDF 지지막은 제막조건인 응고액의 온도가 감소하고 고분자 농도가 증가함에 따라 지지층에서의 표면공극률과 기공의 직경이 감소함을 순수투과실험을 통해서 간접적으로 확인하였고, 복합막에 대한 지지막 구조의 영향을 투과 mechanism식에 적용하여 해석하였다. 또한 PDMS의 두께가 증가됨에 따라 선택도가 증가하는 결과를 통해서, 활성층에서의 물질전달을 Fick's law에 의하여 설명하는데 제한이 있음을 알 수 있었다.