• 전산구조공학
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• 제9권4호
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• pp.209-217
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• 1996

구조물의 손상전후에 나타나는 고유진동수와 모드 형상으로 부터 Inverse Modal Perturbation기법을 이용하여 잔교식 부두나 돌핀과 같은 대규모 항만구조물의 손상도 추정을 위한 모드 기여도 계수를 근사적으로 직접 구하는 방법을 제시하였다. 잔교식 항만구조물의 고유치 해석을 통해 구조물의 강성 변화량과 구조물의 고유진동수와 모드 형상의 변화량과 요소 손상도 계수를 도입하여 Inverse Modal Perturbation의 2차항을 고려한 관계식을 유도하고 손상전후에 구조물의 강성 감소로 나타나는 구조물의 손상도를 추정하여 수렴정도를 고찰하였다.

• 한국환경과학회지
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• 제1권2호
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• pp.1-13
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• 1992

Physiological toxic and mutagenic effects of gramoxone in Drosophila melanogaster were invetigated. Gramoxone was highly toxic on the development, resulting in of lowering the viability and in prolongation of the developmental times. Adults treated with gramoxone during the developmental stages caused a lowering of the productivity and a little chinge in protein quantity. But the effect on the sex-linked lethal mutagenesis was found to be negative. The order of mortality causing ado리t stoa형e feeding to gramoxone in the D. melanogaster complex was like this ; D. mauritiana, D. sechellia, D. simulans and D. melanogasteu Two species of the D. yakuba complex were alike. Those results were more or less correlation with speciation of the D. melanogaster subgroup.

• 한국공작기계학회논문집
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• 제15권5호
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• pp.97-103
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• 2006

A meso-scale analysis method using the natural element method, which is a kind of meshless method, is proposed for the analysis of material damage of brittle microcracking solids such as ceramic materials, concrete and rocks. The microcracking is assumed to occur along Voronoi edges in the Voronoi diagram generated using the nodal points as the generators. The mechanical effect of microcracks is considered by controlling the material constants in the neighborhood of the microcracks. The macro elastic moduli of anisotropic as well as isotropic solids containing a number of randomly distributed microcracks are calculated in order to demonstrate the validity of the proposed method.

• 생약학회지
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• 제19권4호
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• pp.262-269
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• 1988

The Forsythiae fructus is described to be used as an antiinflammatory drug, diuretics, antidotes and antibacterials in oriental literatures. In order to investigate the efficacy of Forsythiae viridissima (Oleaceae), the methanol extract and its fraction have been evaluated for the acute toxicity, antiinflammatory, analgesic and spasmolytic action in animals. The methanol extract of Forsythiae fructus was found to have significant antiinflammatory activity in the acute and subacute antiinflammatory model in rats, but have no analgesic action. Furthermore, through fractionation procedure, it was found that the active compounds were easily soluble in chloroform and butanol. It is also noted that the extracts had spasmolytic activities in the rat fundus and uterus and had low acute toxicity in mice.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.172-175
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• 2002

Sloshing of fuel in a liquid propellant tank is an important part of the dynamic and the stability analysis of the rocket. Baffles are installed in a propellant tank to reduce the instability due to sloshing. Multi degree of spring-mass-damper model was used to model sloshing of fuel in an axisymmetric tank. The natural frequencies and damping ratios are estimated. In order to verify the estimated natural frequencies and damping ratios, tests are performed for the real propellant tank of KSR-III with single ring baffle. Results of fuel sloshing analysis are compared with those of tests.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권2호
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• pp.153-157
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• 2005

Recently two breeding programs were carried out for isolation of new parental inbred lines in Iran. This study was undertaken in order to estimate the combining ability effects and heterosis of these lines. For this purpose an $8\times8$ diallel cross analysis including eight inbred lines of silkworm with four lines from each program were studied for their five quantitative traits. The results indicated that reciprocal effects appeared insignificant for most of traits. Japanese lines of 111 and 113 were best combiners for shell weight, cocoon weight and shell percentage traits. With respect to pupation rate, Chinese line 110 was the best and according to general combining ability (GCA) and specific combining ability (SCA) variances, it is superior in specific combinations. Hybrid $109\times110$ showed better characters for both productive and viability traits. Hybrids with high heterosis had high SCA too.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.353-358
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• 1998

In general, we have used the finite element method(FEM) to find natural frequencies of plates. In this method, however, it is necessary to use a large amount of computer memory and computation time because the FEM requires many degrees of freedom for finding natural frequencies of plates correctly. Therefore it was very difficult to analyze the free vibration of plates correctly on personal computer. For overcoming this disadvantage of the FEM, the authors have developed the finite element-transfer stiffness coefficient method(FE-TSCM) which is based on the concept of modeling techniques in the FEM and the transfer of the stiffness coefficient in the transfer stiffness coefficient method. In this paper, we formulate free vibration analysis algorithm of rectangular plates using the FE-TSCM. Some numerical examples of rectangular plates are proposed, and their results and computation times obtained by the FE-TSCM are compared with those by the FEM and the finite element-transfer matrix method in order to demonstrate the accuracy and efficiency of the FE-TSCM.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.124-128
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• 1998

The procedures currently used for determining microbiological quality of natural mineral water recommend filtration through membrane filters. In this study, we evaluated the effect of vacuum pressure for the accurate detection of bacteria from water samples seeded with Escherichia coli. We observed that the number of E. coli detected increased with increasing vacuum pressure. In order to examine the retention rate of bacteria in the holes of the membranes under the different pressures, the membrane filters were removed after filtration, washed with sterile water by vortexing, and placed on m-Endo agar plates. With all the filters tested, the number of E. coli retained within the filters at negative 600 mmHg was approximately 10 to $20\%$ higher than that obtained with 100 mmHg. These results demonstrate that the vacuum pressure exerted during the filtration procedure may affect the fixation of bacteria into some portions of openings in the membrane filter.

• 한국농공학회논문집
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• 제48권3호
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• pp.3-8
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• 2006

The fractions of nitrogen were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The content of total-N varied to ranged form 619 to 5,534 mg/kg dry weight with a mean value of 1,857 mg/kg. The order of different fractions of nitrogen was as follows: Acid non-extractable-N > uncounted-N > acid extractable-N > ammonia-N > nitrate-N. The content of ammonia-N, acid extractable-N, and acid non-extractable-N showed highly negative correlations with pH. The content of acid extractable-N and ammonia-N showed highly positive correlation with clay content.

• 패션비즈니스
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• 제18권4호
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• pp.114-124
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• 2014

This research was carried out to find the mordant effects by Tara and Myrobalan as natural tannins on the cow leather dyed with Lac powder. The cow leathers were treated with Tara, Myrobalan, Al, Cu, and Fe mordants by changing treatment orders. It was examined for K/S value, surface color changes, and color difference. The K/S value generally has higher Myrobalan than Tara, and pre-mordant than post-mordanted condition. Cu is the strongest among the three mordants. As a results of the treatment order, the K/S value is higer in pre-tannin-mordant agent than in pre-mordant agent-tannin. In the post mordant, K/S value is higher in mordant agent-tannin than in tannin-mordant agent. The color difference and color factors such as H, V and C were various according to the mordant agents, treatment orders and mordant methods; and surface colors of dyed cow leathers were R and RP. It was difficult to find some significant means of mordant orders.