• 미생물학회지
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• 제4권2호
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• pp.1-4
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• 1966

As a part of studies of plant tumor induction, this experiment was prepared for the purpose of studying the ability of tumor induction and the tendency of tumor initiation in some Korean plants using the various Agrobacterium tumefaciens strains. Results obtained from this experiment are as follows. The virulences of five strains used in this experiment were gradually decreased in order of strain A6Kl, B6, 11BV7, T37 and 11 BNV6. Especially strain T37 which is known to the host limited strain showed virulent effect to the most of plants given for the materials as well as strain A6Kl, B 6 and 11BV7. Concerning the grade of tumor development, in plants which has tough stem, for example, Glycine max Meer, tumor induction was not well developed after the inoculation of all strains. Particullary in Ricinus communes Linne all strains showed virulent effect but tumor tissues were declined in relation to the development of lignification. It was also confirmed that the induction of tumor tissues on plants is to delay according to the increase of the age of host plants.

• 자원리싸이클링
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• 제13권3호
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• pp.43-49
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• 2004

플라스틱 재료는 재생이 가능한 열가소성 플라스틱과 재생이 거의 불가능한 열경화성 플라스틱으로 분류 할 수 있고, 본 연구에서는 재생이 가능한 열가소성 플라스틱 중 산업 및 생활 전반에 널리 사용되고 있는 PP. PA6, PC 및 PBT 재료의 재생 방안에 대한 기초 연구로서 재생 재료의 혼합비가 증가함에 따라 치수 정밀도에 미치는 영향을 고찰하였다.

• 한국연소학회지
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• 제15권4호
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• pp.53-57
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• 2010

The purpose of the present work is to investigate the effect of gasoline-premixing on a combustion and emissions characteristics in a compression ignition engine. For studying combustion characteristics, a combustion pressure and rate of heat release (ROHR) were measured using a single-cylinder DI compression ignition engine with a common-rail injection system and premixed fuel injection system. In addition, exhaust emissions characteristics were studied using emission analyzers and smoke meter. The experimental results showed that the case of gasoline-premixing had longer ignition delay and lower combustion pressure compared to the cases of diesel direct injection. Furthermore, premixed gasoline-air mixture reduced NOx emissions due to low peak of ROHR.

• 응용통계연구
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• 제25권3호
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• pp.415-422
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• 2012

For statistical microarray data analysis, clustering analysis is a useful exploratory technique and offers the promise of simultaneously studying the variation of many genes. However, most of the proposed clustering methods are not rigorously solved for a time-course microarray data cluster and for a fitting time covariate; therefore, a statistical method is needed to form a cluster and represent a linear trend of each cluster for each gene. In this research, we developed a modified hierarchical mixture of an experts model to suggest clustering data and characterize each cluster using a linear mixed effect model. The feasibility of the proposed method is illustrated by an application to the human fibroblast data suggested by Iyer et al. (1999).

• Tribology and Lubricants
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• 제12권3호
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• pp.85-91
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• 1996

An analysis for turbulent hybrid beatings with fluid inertia and swirl injection effect was derived for studying static characteristics of swirl-controlled hybrid journal. The swirl-controlled hybrid journal beating is considered to have more freedom in stability control in high speed rotating machinery. Current analysis is compared with experimental results with 3-recess hydrostatic journal bearing. The analysis revealed that the fluid momentum exchange at orifice discharge could produce pressure rise inside the recess region which can control the shear flow induced by journal rotation. The analysis also shows that the swirl-controlled hybrid journal beating has a capability of controlling load carrying capacity and stability by manipulating supply pressure and injection angle.

• 대한기계학회논문집
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• 제19권2호
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• pp.537-547
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• 1995

Numerical study on the chaotic stirring of viscous flow in an alternately driven cavity has been performed. Even under the Stokes-flow assumption, the inherent singularity at the corners made the problem not so easily accessible. With some special treatments to the region near the corners, the biharmonic equation was solved numerically by using the fully implicit method. The velocity field was then used in obtaining the trajectories of passive particles for studying the stirring effect. The three tools developed in the field of the nonlinear dynamics and chaos, that are the Poincare sections, the unstable manifolds, and the Lyapunov exponents, were used in analysing the stirring effect. It was shown that the unstable manifolds obtained in this study well fit the experimental results given by the previous investigators. It is predicted that the best stirring can be obtained when the aspect ratio a is near 0.8 and the dimensionless period T is in the range 4.3 - 4.7.

• 혜화의학회지
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• 제25권1호
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• pp.37-44
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• 2016

Objectives : This study was designed to investigate the effect of Gamishinchubogun-tang (JiaweiShenzhuibujian-tang; GSB) on regeneration of PC12 cells. Methods : PC12 cells have been used extensively as a model for studying the cellular and molecular effects of neuronal cells. In order to check the effect of GSB on the regeneration of PC12 cells, the morphological change of PC12 cells were observed comparatively in GSB group and control group. Results : The significant changes in neurite length of PC12 cells have been observed on GSB group. In proportion to the concentration of GSB it was observed an increase in neurite outgrowth. Conclusions : This study confirmed that GSB made a significant influence on regeneration of PC12 cells.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.361-371
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• 2005

The confined concrete subjected multi-axial stresses have been known as the fact it increases strength of concrete significantly compared with unconfined concrete. Many researchers have studied in confining effects of concrete, and now are studying in many fields. Although many researches about confined concrete using FRP have been studied recently, it is difficult to apply concrete confined by FRP in real structures because FRP is a brittle material. To investigate the influence of concrete strength and ductility increased by confining stiffness in steel, this study was tested and compared with 51 specimens confined by different shapes and thicknesses of steel tube. This test verified the increasement of strength and ductility in confined concrete. Also, analyzing the experimental data by regression method, this study provides stress-strain model about CSS and R4S considering effect of confinement stiffness on the stress-strain relations of concrete.

• 한국대기환경학회지
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• 제11권2호
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• pp.145-152
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• 1995

Predictability of a Gaussian model, ISCST2 was assessed by scaling up wind tunnel experiments with a 1/3,000 terrain model to the real scale. Concentration profiles obtained from the flat-terrain experiment in the neutral condition were estimated to be in agreement with the calculated ones from ISCST2 in the stability class A, but the difference between the two was still large. Concentration profiles from the mountainous-terrain experiments were better fitted to the calculated ones primarily because in the experiment, concentration behind the source was raised due to the effect of a hill in the upstream side. Model prediction was improved with including the downwash effect of buildings and the hill, but overall concentration profiles were not much different from a typical Gaussian profile. While concentration profiles in the experiments were changed with local flows by varying the wind direction and the topography, those from the Gaussian modeling were mot freely changed together with these variations.

• Natural Product Sciences
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• 제2권1호
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• pp.43-47
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• 1996

Macrophages play an important role in host defense against tumors by killing tumor cells. Our work is directed toward studying the effect of the extracts of Salvia plebeia on induction of antitumor activity in macrophages, since it has been usezd as a folk-medicine for the treatment of hepatitis and tumors. The ability of macrophage treated with the plant extracts to inhibit the growth of tumor cells was assessed. The Extracts of the plant induced antitumor activity and could enhance the tumoricidal activity of macrophages when used in combination with $IFN-{\gamma}$. These results suggest that Salvia plebeia extract contain immunomodulatory factors responsible for the induction of the antitumor activity.