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        검색결과 16

        3.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the densification behavior of rhenium alloys including W-25 wt.%Re and Re-2W-1Ta (pure Re) during sintering. The dilatometry experiments were carried out to obtain the in-situ shrinkage in H2 atmo-sphere. The measured data was analyzed through shrinkage, strain rate and relative density, and then symmetricallytreated to construct the linearized form of master sintering curve (MSC) and MSC as a well-known and straightforwardapproach to describe the densification behavior during sintering. The densification behaviors for each material were ana-lyzed in many respects including apparent activation energy, densification parameter, and densification ratio. MSC witha minimal set of preliminary experiments can make the densification behavior to be characterized and predicted as wellas provide guideline to sinter cycle design. Considering the results of linearized form and MSC, it was confirmed thatthe W-25 wt.%Re compared to Pure Re is more easily densified at the relatively low temperature.
        4,000원
        5.
        2020.04 KCI 등재 서비스 종료(열람 제한)
        In the past 20 years, passenger and cargo transportation performance at the international passenger ports in Korea have increased by 8.6% on the compound annual growth rate, respectively. The Korean government had expected to continue expanding the market of car ferries and the government included plans for the development of additional routes and lanes with neighboring countries such as China, Japan, and Russia as a part of the Plan of the Korean Ministry of Oceans and Fisheries in 2019. However, compared to the development of routes, the management and operation of passenger terminals are inefficient. The purpose of this paper was to introduce the overall improvement of the passenger terminal operating system that reflects the recent changes in the supply and demand of international passenger vessels and the needs of the government and private sector passengers. To this end, a basic survey was conducted on the status of operations and facilities at the Busan International Passenger Terminal and a questionnaire survey was administered on the subject of use. The results of the survey were analyzed using the IPA model. As a result of the analysis, three items in the operation sector, three items in the facility sector, and four items in the system sector of the Busan International Passenger Terminal were identified as in need of improvement. Based on the results, the need for investment to improve the international passenger terminal operating system is suggested.
        8.
        2011.08 KCI 등재 서비스 종료(열람 제한)
        This study is to generate SCARs markers for identification of Perilla species. A SCAR is a genomic DNA fragment at a single genetically defined locus that is identified by PCR amplification using a pair of specific oligonucleotide primers. We derived SCARs by sequencing and cloning the both ends of the amplified products of RAPD markers. Sixteen sequence-specific primers were synthesized from eight RAPD markers, which were completely sequenced. We developed the species-specific SCAR markers which could be used successfully in detecting genetic variation in four Perilla species. These markers could be used to verify species-origins of various forms of Perilla germplasms.
        16.
        2000.12 KCI 등재 서비스 종료(열람 제한)
        The technology of direct-seeding in rice cultivation is an innovation mainly induced by factors in market economy and is rapidly diffused among individual farmhouses. Because the effect of technology can be affected by many factors under various farming circumstances, the impact and stability of the direct-seeding technology compared with transplanting was analyzed under various topographical regions. Yield in direct-seeding was higher in plains, although the farm size producing higher yield was quite different depending on the topographical regions. In the direct-seeding cultivation of rice, man-labor hours was reduced by about 38 percent and the reduction rate showed little difference among topographical regions. Fertilizer was used about 11 percent more but the increase rate varied from 3 to 17 percent depending on regions with higher rates in plains. Application of agricultural chemicals was also increased about 9 percent in direct-seeding, but the increase rate was as high as 12 percent in suburbs. More fertilizer and agricultural chemicals were used in direct-seeding cultivation by farmhouses implementing both direct-seeding and transplanting than by those implementing direct-seeding only. Use of more fertilizers and agricultural chemicals in direct-seeding in all regions may indicate its technical instability. Major problems causing the technical instability of direct-seeding cultivation should be solved by comprehensive research considering various farming circumstances such as topographical features rather than just a top-down style research and extension.