• ALGAE
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• 제31권4호
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• pp.391-401
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• 2016

To develop an easy and rapid method of quantifying lipid contents of marine dinoflagellates, we quantified lipid contents of common dinoflagellate species using a colorimetric method based on the sulpho-phospho-vanillin reaction. In this method, the optical density measured using a spectrophotometer was significantly positively correlated with the known lipid content of a standard oil (Canola oil). When using this method, the lipid content of each of the dinoflagellates Alexandrium minutum, Prorocentrum micans, P. minimum, and Lingulodinium polyedrum was also significantly positively correlated with the optical density and equivalent intensity of color. Thus, when comparing the color intensity or the optical density of a sample of a microalgal species with known color intensities or optical density, the lipid content of the target species could be rapidly quantified. Furthermore, the results of the sensitivity tests showed that only $1-3{\times}10^5cells$ of P. minimum and A. minutum, $10^4cells$ of P. micans, and $10^3cells$ of L. polyedrum (approximately 1-5 mL of dense cultures) were needed to determine the lipid content per cell. When the lipid content per cell of 9 dinoflagellates, a diatom, and a chlorophyte was analyzed using this method, the lipid content per cell of these microalgae, with the exception of the diatom, were significantly positively correlated with cell size, however, volume specific lipid content per cell was negatively correlated with cell size. Thus, this sulpho-phospho-vanillin method is an easy and rapid method of quantifying the lipid content of autotrophic, mixotrophic, and heterotrophic dinoflagellate species.

• Journal of Plant Biology
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• 제37권4호
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• pp.403-410
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• 1994

The taxonomic criterion between Erythroglossum and Sorella was reappraised based on Korean plants of E. minimum Okamura and S. repens (Okamura) Hollenberg. Development of the reproductive organs was observed from field collected plants as well as cultured plants. The Polyneura-tuype procarp which comprised one group of sterile cells and two carpogonial branches arising from a supporting cell was observed in both species. Distribution of tetrasporangial sori was irregular in both species, so it is not relevant to distinguish Sorella from Erythroglossum by the characteristic of tetrasporangial distribution. E. minimum and S. repens were very similar in vegetative form, but were reproductively isolated. Chromosome numbers were given as n=ca. 30 in S. repens and n=ca. 41 in E. minimum, respectively.

• 한국공간정보시스템학회 논문지
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• 제6권2호
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• pp.23-37
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• 2004

최근 GPS기능을 탑재한 휴대폰 PDA등의 모바일 장치를 사용하여 위치 기반 서비스를 이용하는 사용자가 급증하고 있다. 이에 위치 정보를 지닌 공간 데이타를 저장하고 관리하는 대용량의 공간 데이타베이스는 사용자의 다양한 질의 조건과 빠른 검색을 가능하게 하기 위한 색인이 필요하며 대표적인 색인 기법으로는 R-tree가 널리 사용되고 있다. 기존의 R-tree를 이용한 검색은 질의 영역과 관계없는 공간 데이타까지 검색하여 불필요한 입출력을 유발하기 때문에 응답시간이 늦어진다. 본 논문에서는 공간 데이타가 위치 기반 질의를 지원하기 위해 자신이 속한 노드의 전체(Union) MBR 영역에 따라 동적으로 셀 레벨 값을 구성하는 CLR-트리(Cell Leveling R-tree)를 제안한다. 또한, CLR-트리에서의 새로운 공간 데이타의 삽입, 분할, 삭제, 검색 알고리즘을 제안한다. 제안된 CLR-트리에서는 위치 기반 질의 시 사용자 질의 영역의 셀 레벨 값과 공간 데이타의 셀 레벨 값을 비교하여, 겹치지 않는 셀에 대해서는 검색 대상으로부터 제거하고 연관된 셀만을 검색하기 때문에 빠른 응답시간을 제공한다. 디스크 입출력 실험에서 CLR-트리가 기존 R-tree보다 디스크 접근 수를 $5{\sim}20%$ 감소시켜 사용자의 위치 기반 질의에 대해 빠르게 처리함을 알 수 있었다.

• 한국수소및신에너지학회논문집
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• 제14권3호
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• pp.236-246
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• 2003

This paper focuses on developing a model of a PEM fuel cell stack and to integrate it with realistic model of the air supply system for fuel cell vehicle application. The fuel cell system model is realistically and accurately simulated air supply operation and its effect on the system power and efficiency using simulation tool Matlab/Simulink. The Peak performance found at a pressure ratio of 3, and it give a 15mV increase per cell. The limit imposed is a minimum SR(Stoichiometric Ratio) of 2 at low fuel cell load and 2.5 at high fuel cell load.

• 설비공학논문집
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• 제7권2호
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• pp.207-216
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• 1995

Flow and heat transfer characteristics of mixed convection heat transfer in a rectangular en-closure with various outlets are numerically investigated. The parameters considered here include Reynolds number, Grashof number and the position of outlet. The results show streamlines, isotherms, Nusselt numbers, velocity and temperature distributions. It has been shown that as Reynolds number increases, the size of cell decreases at Re$\leq$100 and increases at Re>100 for $Gr=10^4$. There is a minimum size of cells at Re=100, $Gr=10^4$. The maximum mean Nusselt number occurs at Re=400, $Gr=10^4$ and one right outlet. The mean Nusselt numbers can be formulated by the correlation equation $Nu=C{\cdot}Gr^a{\cdot}Re^b$.

• 한국해양공학회지
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• 제10권4호
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• pp.109-117
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• 1996

The numerical and experimental studies on the mixed convection of a rectangular enclosure for indoor air control has been studied numerically using the finite volume method and experimentally with holographic interferometry and Laser apparatus. The parameters studied here are Pr= 0.71, $30{\leq}Re{\leq}600$, $700{\leq}Gr{\leq}100000$ and the positions of an outlet. The results show streamlines, isothrems, velocity distributions and photograph of holographic interferometry and streamlines. It is found that the minimum cell occurs at Re=100, Gr=10000. The mean Nusselt numbers can be expressed by the correlation equation $Nu=C{\cdot}Gr^a$ $Re^b.$ The comparison of numerical and experimental results shows a good agreement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1110-1111
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• 2008

The life time of PV module is semi-permanent. But, because of installation and module fabrication process, its important part can not be finished. In this paper, we analyze 15 years old modules made from different company. Among the PV modules, the maximum power drop ratio was 12.23% minimum and 80.63% maximum. Also the effect of solar cell's short circuit current difference was analyzed. The PV module exposed about 65days, its the maximum power drop ratio was 1.29% minimum and 23.43% maximum. It is for reduction of current value. And the reason for current reduction was due to reduction of parallel resistance of solar cell. To prevent early degradation, it is need to have attention to fabrication, installation and maintenance.

• ALGAE
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• 제20권3호
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• pp.233-238
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• 2005

The photosynthetic parameters of dark- adapted minimum fluorescence (Fo) and maximum quantum yield of charge separation in PSII (Fv/Fm) were measured in transverse sections of eight species of marine Phaeophyceae (species of Laminariales, Fucales, Desmarestiales, Chordariales) using pulse amplified modulation (PAM) fluorometry. Within each transverse section fluorescence was measured in three regions corresponding to outer cortical and meristoderm cells, inner cortical cells and innermost medullary cells. Minimum fluorescence declined from 19-74% (mean of 39%) from outermost to innermost cells. Maximum quantum yield varied from 0.51-0.59 in outermost cell layers and this was reduced to 0.23-0.40 in innermost cell layers, with an average reduction of 50%. Despite the reduction Fo in medullary cells (inner), medullas of all species showed maximum quantum yields consistent with a photosynthetic role in carbon fixation. These results show that medullary cells of complex brown algae have more than a role in structure, storage or transport, and may also provide an important role in carbon fixation.

• Mycobiology
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• 제30권2호
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• pp.93-95
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• 2002

The antifungal activities of propolis on Cryptococcus neoformans and Candida albicans were evaluated. In microbroth culture assay, the MIC(minimum inhibitory concentration) of propolis for C. neoformans and C. albicans were 2 and 16 mg/ml, respectively. In propolis-included solid medium assay, the MIC of propolis for C. neoformans and C. albicans were 4 and 16 mg/ml, respectively. Propolis showed fungicidal activity against C. neoformans, whereas propolis possesed fungistatic activity against C. albicans. The MFC(minimum fungicidal concentration) for C. neoformans was 8 mg/ml. Cell morphology of C. neoformans was affected by treatment of propolis. In scanning electron microscope, the appearance of cell rupture was observed.

• 로봇학회논문지
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• 제1권1호
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• pp.9-16
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• 2006

The Mobile robots are increasingly being used to perform tasks in unknown environments. The potential of robots to undertake such tasks lies in their ability to intelligently and efficiently search in an environment. An algorithm has been developed for robots which explore the environment to measure the physical properties (dust in this paper). While the robot is moving, it measures the amount of dust and registers the value in the corresponding grid cell. The robot moves from local maximum to local minimum, then to another local maximum, and repeats. To reach the local maximum or minimum, simple gradient following is used. Robust estimation of the gradient using perturbation/correlation, which is very effective when analytical solution is not available, is described. By introducing the probability of each grid cell, and considering the probability distribution, the robot doesn't have to visit all the grid cells in the environment still providing fast and efficient sensing. The extended algorithm to coordinate multiple robots is presented with simulation results.