• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.291-294
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• 2012

Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.98-101
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• 2000

The Internet can be considered as a good environment for dwelling of many types of virtual lives. If we could build up the proper ecosystem with the lives in the internet, It would be possible to implement the system as a life. The life system thus obtained would provide us some decisive advantages, which is hardly available by the reduction paradigm. In this paper, we presented an ecosystem based on Internet, which will be followed by the discussion of its meaning in terms of usefulness.

• Animal Systematics, Evolution and Diversity
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• v.33 no.1
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• pp.33-36
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• 2017

Two new Hydropsychidae (Insecta: Trichoptera) species from the Philippines are described. Hydropsyche philippinensis, n. sp., differs from other congeners in the structure of the phallic apparatus. Diplectrona lagunensis, n. sp., can be distinguished from other congeners by its distinct white band pattern in the forewings and by the structure of the phallus. Both new species were collected from a high mountain stream in the northern part of the Philippines. Paratype materials were barcoded to make the sequences readily available in the GenBank.

• Journal of Life Science
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• v.3 no.2
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• pp.91-114
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• 1993

키틴은 N-아세틸-D-글루코사민 잔기가 다수 beta-(1, 4) 결합하고 있는 다당류이고, 그 탈아세틸화물을 키토산이라 한다. 키토산도 D-글루코사민의 beta-(1, 4) 중합체이지만 보통 약간의 아세틸기를 가지고 있는 것을 키토산이라 부르고 있다. 현재로는 제조 키틴의 대부분이 키토산으로 변환되어 응집제로서 폐수처리에 이용되고 있고, 기타 많은 용도가 개발되어 있지만 아직 연구단계에 있다. 따라서 키틴이나 키토산 분자의 잠재적 기능을 개발하여 인간생활에 유효하게 이용하도록 한다는 것은 폐기물 처리나 미이용 지원의 개발이라는 측면에서 볼 때 중요한 문제라고 볼 수 있다. 따라서 본고에서는 키틴의 생물계에서의 분포, 입체배좌, 제조법, 물성 및 기능성 그리고 그 용도에 대해 간추렸다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2271-2279
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• 1993

In the case of life prediction on the structures and machines after long service, it is natural to consider a degradation problems. Most of degradation data form practical structures are isolated data obtained at the time of periodical inspection or repair. From such data, it may be difficult to obtain the degradation curve available and necessary for life prediction. In this paper, for the purpose of obtaining a degradation curves, developed the simulate degradation method and fatigue test and Charpy impact test were conducted on the degraded, simulate degraded and recovered materials. Fatigue life prediction were conducted by using the relationship between fracture transition temperature (DBTT : vTrs) obtained from the Charpy impact test through the degradation process and fatigue crack growth constants of m and C obtained from the fatigue test.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.103-117
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• 1988

Replacement demand plays an important role to forecast the total demand of durable goods, while most of the diffusion models deal with only adoption data, namely initial purchase demand. This paper presents replacement demand forecasting models incorporating repurchase rate, multi-ownership, and dynamic product life to complement the existing diffusion models. The performance of replacement demand forecasting models are analyzed and practical guidelines for the application of the models are suggested when life distribution data or adoption data are not available.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.319-328
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• 2000

This paper presents a new design method of the 1 generation wheel bearing unit using a numerical optimization technique in order to increase bearing fatigue life. For calculating the fatigue life, a method of load analysis is studied on the automotive wheel bearing system. The design variables selected are ball size, initial contact angle, number of balls, pitch diameter, pre-load, and distance between ball centers. The method of feasible directions in ADS (Automated Design Synthesis) is utilized to automatically find the optimum design variables. To validate the design method, a computer program is developed and applied to a practical passenger car model. The optimum design results demonstrated the effectiveness of the proposed design method showing that the system life of the optimally designed wheel bearing unit is enhanced in comparison with that of the initial ones within the given available design space.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.760-780
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• 1988

Using the fatigue test results obtained in the SAE Fatigue Cumulative Damage Test Program, prediction methods of fatigue crack initiation life for notched members undergoing random loaming histories were discussed in detail. Conventional fatigue life predictions based on so-called modified Miner's rule were found to be apt to give nonconservative estimate, due to lack of sufficient consideration for stress-interaction effect. A modified .epsilon.-N curve concept was proposed to account for the stress-interaction effect. The predicted fatigue life based on the modified .epsilon.-N curve concept was in good agreement with the experimental results of SAE Test Program. Specifically for the cases when fatigue data was not available at hand, was proposed a procedure to give conservative estimate of fatigue life.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.191-199
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• 2001

We have constructed a cDNA library from the whole body of the spider, Araneus ventricosus. Sequence analysis of randomly selected cDNA clones was performed to obtain genetic information on the spider A. ventricosus, of which genetic information is currently not available. We have partially sequenced randomly selected 385 clones of the cDNA library constructed from A. ventricosus. This expressed sequence tags (EST) analysis revealed 383 genes had high homologies to known genes in GenBank. In this report, 241 independent genes were analyzed in detail.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.344-349
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• 2009

To be Low Carbon and Green Growth, it is necessary that Long-Life Housing based on Green Technology is supplied. The main concern at the moment is developing Sustainable Housing relative to Life-Cycle or Life-Style of the residents, and the resident of Remodeling or Redevelopment. This study is aim to be Development of Maintenance Process in order to make steady dwelling when supplying Long-Life Housing that separates Support(Skeleton) and Infill different from the existing Short-Life Housing, and has durability, alterability, available remodeling, easy maintenance. Long-Life Housing should consider the maintenance about movement and variableness. In contrast, the maintenance of the existing Housing is regular maintenance, change and repair by damage. As well as Long-Life Housing should be demanded proper Development of Maintenance Process because of difference of Housing in concept, design and Construction. Therefore, this study looks into problems when applying Development of Maintenance Process in Long-Life Housing, and shows Development of Maintenance Process about the efficient Long-Life Housing for the manager.