• Computers and Concrete
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• 제8권3호
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• pp.327-341
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• 2011

Three-dimensional graphic objects created by MATLAB are exported to the AUTOCAD program through the MATLAB handle functions. The imported SAT format files are used to produce the finite element mesh for MSC.PATRAN. Based on the Monte-Carlo random sample principle, the material heterogeneity of cement composites with randomly distributed fibers is described by the WEIBULL distribution function. In this paper, a concept called "soft region" including micro-defects, micro-voids, etc. is put forward for the simulation of crack propagation in fiber-reinforced cement composites. The performance of the numerical model is demonstrated by several examples involving crack initiation and growth in the composites under three-dimensional stress conditions: tensile loading; compressive loading and crack growth along a bimaterial interface.

• 한국세라믹학회지
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• 제38권2호
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• pp.238-238
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• 2001

본 연구에서는 kaolin을 이용하여 반기상법, gel coating법, seed 첨가법으로 mullite를 합성하였으며 mullite 15 wt%를 고 알루미나질 내화물 원료에 첨가하여 내화물 시편을 제조하였다. 제조된 시편의 물성을 분석한 결과 seed 첨가법으로 제조된 mullite를 첨가한 시편의 물성이 338.60 MPa의 꺾임강도와 9,427 kgf/㎠의 압축강도값을 나타내었다. 제조된 시편의 내화도 및 잔존선팽창수축률을 측정한 결과 나머지 두가지 방법으로 합성한 mullite나 일반적인 고 알루미나질 내화물에 비하여 좋은 특성을 나타내었다.

• Mycobiology
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• 제32권4호
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• pp.186-189
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• 2004

The study on the cultural characteristics of Bipolaris spicifera was conducted to provide with information for the identification, and inoculation studies, etc. B. spicifera grew well at $30{\sim}35^{\circ}C$ and wide range of pH $5.0{\sim}9.0$. However, the fungal growth was retarded at pH 4.0 and 10.0, respectively. Conidia were germinated with 70% at $30^{\circ}C$ but maintained 50% germination even at $40^{\circ}C$, indicating that this pathogen could infect plants at relatively high temperature. The pathogen could not produce conidia under 24 hr fluorescent light condition for 7 days. In contrast, it produced many more conidia at 24 hr dark condition.

• Asian-Australasian Journal of Animal Sciences
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• 제31권7호
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• pp.933-950
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• 2018

In Japan, Wagyu cattle include four Japanese breeds; Black, Brown, Shorthorn, and Polled. Today, the renowned brand name Wagyu includes not only cattle produced in Japan, but also cattle produced in countries such as Australia and the United States. In recent years, the intramuscular fat percentage in beef (longissimus muscle) from Japanese Black cattle has increased to be greater than 30%. The Japanese Black breed is genetically predisposed to producing carcass lipids containing higher concentrations of monounsaturated fatty acids than other breeds. However, there are numerous problems with the management of this breed including high production costs, disposal of untreated excrement, the requirement for imported feed, and food security risks resulting from various viral diseases introduced by imported feed. The feeding system needs to shift to one that is more efficient, and improves management for farmers, food security for consumers, and the health environment for residents of Japan. Currently, we are developing a metabolic programming and an information and communications technology (ICT, or Interne of Things) management system for Wagyu beef production as future systems. If successful, we will produce safe, high-quality Wagyu beef using domestic pasture resources while solving the problems of how to utilize increasing areas of abandoned agricultural land and to make use of the plant-based feed resources in Japan's mountainous areas.

• 한국수정란이식학회지
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• 제5권2호
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• pp.38-44
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• 1990

This study was carried out to produce superior dairy cattle by embryo transfer. Seven dairy cows were superovulated with divided injection of FSH 4Omg for 5 days started on day 9 to 14 of the estrus cycle and injection of PGF$_2$$\alpha$ 45mg on day 4 of FSH injection. Donor cows were flushed to collect embryos on day 7 or 8 of the estrus cycle. Fresh embryos collected were transferred to synchronized dairy recipients or frozen using glycerol 3 step method to he equilibrated. And 35 embryos which were frozen using glycerol 6 step method were imported from U.S.A. After glycerol dilution of frozen embryos was done by reverse density during freezing. frozen-thawed embryos were transferred to synchronized dairy or beef recipients. The results obtained were as follows; 1. Total of 24 embryos were collected from 7 donor cows flushed and transferable embryos were 18 (75.0%). 2. Among 24 embryos. morula, early blastocyst, blastocyst, expanded blastocyst and unfertilized ova were 3 (12.5%), 1 (4.2%), 10 (41.6%), 4 (16.7%) and 6 (25.0%), respectively. 3. Heat inducing rate after 1st and 2nd injections of PGF$_2$$\alpha$ in Holstein and beef cattle was 83.3% and 71.4% and 62.5% and 69.2%, respectively. 4. Among 56 recipients, 23 head were pregnant (41.1%). The pregnancy rate of fresh embryos was 50.0% (1/2 heads) and the pregnancy rate of frozen embryos which were frozen using glycerol 3 step and using glycerol 6 step imported from U.S.A. was 52.6%(l0/19 heads) and 34.3%(12/35 heads), respectively. 5. The pregnancy rate of blastocyst (60.0%) was higher than that of morula (39.0%), early blastocyst (25.0%) and expanded blastocyst (0%). 6. The pregnancy rate of grade I embryos (52.2%) was higher than that of grade 2 (34.6%) and grade 3 (28.6%). 7. The pregnancy rate according to synchrony of recipient with donor was higher in simultaneous recipient (55.0%) and +l2hrs' (53.8%) than -24hrs' (23.5%), -l2hrs' (20.0%) and +24hrs' (0%).

• 복식
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• 제23권
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• pp.169-181
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• 1994

The Purpose of this study is to help the neck-tie business enterprise establish the reasonable marketing strategy meeting consumer' needs by grasping their characteristic of purchasing neck-ties and their attitudes toward trademarks. The findings of this study are as follows : 1. It was shown that the neck-tie enterprise tended to appeal to megazines, catalogues , etc as promotional politics, while the tips obtained by consumers would come from the showcase at the purchasing place. and the consumer showed a positive response to the salesperson's advice. For this result, it is required to place further emphasis on the marketing policy such as the display of products at the store or the education of sales persons. 2. It was shown that the consumer tended to use the department store as the purchasing place remarkably, and so it could be found that the use of the department store is becoming generalized to the consumer. But is was shown that the consumer sensitive to prices tended to make use of the marketplace as the purchasing place, so the practical marketing strategy should be established in relation to this trend. 3. The important elements excreting an influence on the consumer's purchasing the neck-tie were shown to be in orders of design > color> harmony > with suit > price > quality, and the product differentiation policy used by the business enterprise to appeal to the consumer was shown to be in orders of design >color > quality > material > price. Accordingly , it was consistent with the consumer's criterion for choice to an extent. 4. It was shown that the selling price for the neck-tie brand actually was higher for imported or technically cooperated brands than for the home-made brand. Thus, the consumer's perception of the price for the neck-tie was consistent with in this regard, consumers did not feel some difference in quality between the home -made neck-tie brand and the imported or technically cooperated neck-tie brand . Therefore, it is important to produce the product capable of satisfying the consumer's need by manufacturing the own brand on basis of impored technology.

• 한국포장학회지
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• 제5권1호
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• pp.21-24
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• 1999

시중 유통되고 있는 50종의 목제 주방기구와 위생용품을 각각 benzene과 n-heptane에 용출시켜 GC-MSD를 이용하여 분석한 결과, naphthalene과 diethyl phthalate는 모든 조건에서 검출되지 않았으나, biphenyl의 경우 전 제품에서 미량이 검출되었다. Biphenyl은 자작나무 수입 원목과 국산 원목에서도 각각 0.25 ppm, 0.34 ppm 함유되어 있는 것으로 확인되었다. 또한 biphenyl의 검출량은 목제를 가공하는 과정 중에 감소하며, 그 검출량은 과일의 잔류 허용치 (110 ppm)에 비해 극히 미량인 것으로 판단된다. 따라서 biphenyl의 유입경로는 제품의 제조 및 생산과정에서 첨가되었다기 보다는 제제 자체에 잔존한다고 추정되며, 이러한 biphenyl의 잔존량은 인체에 영향을 미칠 수 있는 농도는 아닌 것으로 판단된다.

• 기술혁신연구
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• 제9권1호
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• pp.149-165
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• 2001

This paper analyses characteristics of the numerical controller industry in market formation and the flow of information between users and producers and the characteristic of knowledge base of the industry and discuses the difficulties derived, from the characteristics, in accumulation of technological capability. In market formation between users and producers, the multi-layered market is not favorable to domestic producers in that lower end market is not large enough to provide cradle market to them which produce inferior quality and lower price than imported products. The credibility of the performance of a product is different to prove until a critical mass of products are sold. Therefore gaining market share is deterred by unproven credibility of the performance of the product. The flow of information between users and producers is limited. The flow of information on users environment through mass market to producers is essential for improving credibility of a product. The nature of knowledge base is tacit and the means of knowledge transmission is limited. Technological licensing and reverse engineering, which have been conventional means of knowledge transmission, are not useful in the numerical controller industry. These characteristics provide conditions of vicious circle in accumulation of technological capability of the numerical controller industry. This paper argues that these characteristics of the industry challenge existing approach to R&D management and framework of science and technology policy.

• 환경영향평가
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• 제7권1호
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• pp.109-116
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• 1998

As of July 1997, the registered number of automobiles exceeded 10 million and Korean auto industry produced 2,850,000 cars. Many environmentalists warn that the passenger cars are not sustainable urban transportation system in large cities. The cars produce about 80% of air pollutants, and consume 30% of petroleum imported. For the past 30 years the administration increased the road system, but the length of road per car is decreased from 813m in 1965 to 9m in 1995. The cost of traffic congestion was estimated to be \14.7 trillion in 1996, and is feared to increase without changing the present transportation system. The undesirable impact of cars include the casualties from traffic accidents, insurance loss, and separation of human relatioships. To construct sustainable urban transportation system, three principles should be followed. The first principle is to make the urban streets walkable for the people. The second principle is to encourage bicycling. Roads and traffic systems should be designed to let bicylces travel safely. The third principle is to supply more buses and construct integrated transportation system based on buses. The subway system is too expensive to construct and without the support of a well-organized bus system it may not work efficiently. The Brazilian city of Curitiba has constructed a very efficient bus system only with 1/80 of the estimated cost of subway system. The car-oriented transportation system does not seem to be an envrironmentally sustainable transportation system in most of the Korean cities.

• 한국작물학회지
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• 제30권4호
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• pp.455-459
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• 1985

우수 이위체 clone을 선발하고 이를 FDR clone으로 육성하고자 본 실험 이 수행되었다. 1) 도입된 2X종자를 포장 및 온실에서 재배하여17 clone이 선발되었으며 이들의 특성이 조사되 고, 이들 Clone을 인공교배, 개방수분, 집단수분하여 그후대에서 18clone 이 선발되었다. 2) 선발된 clone들은 2n웅성과 2n자성배우자 형성에 대하여 조사되었다. 그중 D6-21만이 27∼30％의 2n웅성 배우자를 FDR에 의해 형성하였고. 다른 clone들은 2n웅성 배우자 형성율이 7％ 미만이었다. 3) 자성 2n배우자를 생성하는 clone은 발견되지 않았다.