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        검색결과 282

        141.
        2004.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        침하식 가두리 시설의 안정성 평가를 위한 기초 단계로서 일방향 규칙파 중 2점 계류된 원통형 부체를 대상으로 부설 수심의 변화에 따른 부체의 동적 거동 및 계류삭에 작용하는 장력 산정에 관한 수치 계산을 수행하였다. 수치 계산 결과, 수면 상에 설치된 부체를 수면 아래의 약 1/2되는 수층까지 침하 시킨 경우 그것은 동적 거동과 파력은 초기 상태에 비해 각각 최대 50%와 77%까지 감소되어 시설물을 수중으로 침하 시키면 그것의 안정성 유지에 매우 효과적임을 확인할 수 있었다. 또한 부체의 전 후단 변위 및 계류삭에 작용하는 장력의 최대치는 부체의 고유 주기의 영향으로 인해 그것은 길이 d 에 대한 파장 λ의 비 즉, d/λ가 약 0.66에서 나타났으며, 이와 같은 현상은 기존 수리 모형실험 결과와 비교적 잘 일치하였다. 그러나 본 수치 계산의 신뢰성 확인을 위해서는 수리 모형실험을 통해 부체의 고유 주기와 작용 파고에 대한 전 후단 변위 등에 대한 충분한 검토가 요구된다.
        4,000원
        144.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kim, Kyu-hyun. 2004. A Conversation Analysis of Korean Sentence-Ending Modal Suffixes -ney, -kwun(a), and -ta: Noticing as a Social Action. Sociolinguistic Journal of Korea, 12(1). Drawing upon H. S. Lee's (1993) cognitively-oriented research on the functions of three sentence-ending modal suffixes in Korean that are used to express newly perceived information, -ney, -kwun(a), and -ta, this study analyzes the distinct meanings of these suffixes from a conversation-analytic perspective (Sacks et al. 1974). The suffix -ney is used in the context in which the speaker notices a referent/event and makes an assessment on the spot in such a way that the speaker's stance displayed through the action is formulated as something that is to be immediately oriented to and contingently taken up by the hearer. In contrast, the suffix -kwun(a) is used when the speaker is mainly oriented to displaying a stance congruent with the prior talk. The action it organizes is often limited to acknowledging a point of the prior talk or having the hearer acknowledge the speaker's observation, often with a salient topic-curtailing and sequence-terminating import. The suffix -ta tends to orient the hearer to the next stage of the speaker's action (e.g., suggestion, warning, offer, etc.) to whose directive force the hearer is variably implicated as a beneficiary/facilitator. The interactional account offered in this paper is shown to complement Lee's cognitive account, with emphasis placed on examining the ways in which these suffixes are used as resources for organizing distinct types of social action.
        8,300원
        145.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A peer assessment method was implemented as part of an action research project where the primary goal was to create constructivist science classrooms. Student reflective writings, which had been created in the process of action research, were analyzed to examine the perceptions of the students concerning the peer assessment method employed in their earth science classrooms. Five perception categories and thirteen statements were developed from the student writings. These indicated that the students appreciated the positive nature of peer assessment and the effects of it as an alternative method for promoting learning. It was also revealed, however, that some students displayed inappropriate behaviors toward peer assessment which led to negative perceptions of the new assessment method. Implications for future use of peer assessment in science classrooms are discussed. Limitations founded in the present study as well as possible solutions are provided.
        4,500원
        146.
        2003.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,700원
        147.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        누룩치, 고본, 당귀 및 산초의 ethanol ext.는 자발운동량에 미치는 영향에 대한 시험에서 아무런 영향을 미치지 않았다. 다만 phenobarbital sodium 수면시간에 대해서는 산초투여군에서만 수면시간을 다소 단축시켰다. 0.7% acetic acid의 복강내 투여에 의해 유발된 writhing syndrome을 다소 억제하였으나 유의성은 없었다. 체온에 미치는 영향에 대한 시험에서는 유의성 있는 체온 변화가 없었다. 다만 흰쥐의 위액분비에 미치는 영향에 대한 시험에서는 누룩치와 고본투여군에서 위액분비량과 총산도가 유의적으로 감소하였다. 소장운동능에 미치는 영향에 대한 시험결과 누룩치, 당귀 및 고본투여군에서 유의성 있는 charcoal의 이동억제가 관찰되었다. 결론적으로 누룩치, 고본, 당귀 및 산초의 ethanol ext.는 일반약리작용에 대하여 특이한 작용이 없었다.
        4,000원
        150.
        2002.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        규칙파와 불규칙파 및 흐름이 함께 작용하는 상태에 놓인 가두리 시설에 대해 작용 유체력을 가두리 시설의 부설 방향별로 해석하기 위하여, 정사각형 모형 가두리 시설과 원형 모형 가두리 시설을 대상으로 예인 수조에서 수리 모형 실험을 실시하였다. 실험에서 얻어진 결과를 요약하면 다음과 같다. 1. 규칙파를 받고 있는 정사각형 가두리 시설에 작용하는 유체력은 가두리 시설의 부설 방향별로 큰 차이를 보이지 않았다. 2. 불규칙파와 흐름을 동시에 받고 있는 가두리시설에 작용하는 파력 에너지의 피크 주파수는 파의 그것과 잘 일치하였고, 작용 유체력은 정사각형 가두리 시설보다 원형 가두리 시설에서 더 작았다. 3. 가두리 시설의 안정성에서 있어서는 그 구조가 원형인 것이 정사각형인 것보다 나은 편이었다.
        4,000원
        154.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dual-actions are the most recently used delivery system in drug study. Dual-action agents are unique chemical entities comprised of two different type of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfanilamide such as antibiotics is synthesized by synthetic handle with glutaraldehyde. As a result, New synthetic antibacterial agent exhibited the broad antibacterial activities against gram(+) and gram(-) of 4 strains and a long durability supposing that the stomach and blood.
        4,000원
        156.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dual-action agents are unique chemical entities comprised of two different types of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfacetamide such as antibiotics synthesized by crosslingking reaction such as glutaraldehyde. These structures of the compounds were confirmed by IR, NMR. 4 strains of Gram(+) and Gram(-) revealed effective susceptibility to synthetic crosslinked sulfadiazine-sulfacetamide.
        4,000원
        157.
        1999.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, a greater part of all ship use a coarse heavy fuel oil(HFO) over specific gravity(S.G) 1.00/15℃ and viscosity 3,500 cSt/40℃ as the fuel oil of marine boiler or internal combustion engine from the viewpoint of economical ship' operation. The greater plan to improve a combustion methods of heavy fuel oil, such as atomization, homogeneity and emulsification, were contrived and carried out newly, and then applied 20kHz ultrasonic homogenizer to one of test methods. Also, adopted the marine oils(fuel oil and lubricating oil etc.) and sludge oil as test solutions, and its matrix structures were examined with photographs, Especially, it is important at control system of oil pollution, for the sludge oil emulsified, to be recycled as fuel oil of boiler according to 20kHz Ultrasonic homozenizer, and then fuel saving is attained effectively by making sludge oil to be burnt.
        4,300원
        158.
        1999.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Steering and Sailing Rules of International Regulation for Preventing Collisions at Sea now in use direct actions to avoid collision when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision. But these rules do not refer to the minimum relative distances and safety relative distances between two vessels when they should take such actions.In this paper the ship's collision avoiding actions being analyzed from a viewpoint of ship motions, the mathematical formulas to calculate such relative distances necessary for taking actions to avoid collision were worked out. The values of maneuvering indices being figured out through experiments of 20 actual ships of small, medium, large and mammoth size and applied to calculating formulas, the minimum relative distances and safety relative distances were calculated. The main results were as follows. 1. It was confirmed that the criterion elements for collision avoiding actions in head-on situation of two vessels shall be the minimum relative distances and safety relative distances between them. 2. On the assumption that two vessels same in size and condition were approaching each other in head-on situation, the minimum relative distance of small vessel(GT : 160~650tons) was found to be about 4.7 times her own length, and those of medium (GT:2,300~4,500tons),large(GT:15,000~62,000tons) and mommoth (GT:91,000~194,000tons) vessels were found to be about 5.2 times, about 5.2 times and about 6.1 times their own lengths respectively. 3. On the assumption that two vessels same in size and condition were approaching each other in head-on situation, the safe relative distance of small vessel (GT : 160~650tons) was found to be about 6.8 times her own length, and those of medium (GT : 2,300~4,500tons), large (GT: 15,000~62,000tons) and mammoth (GT : 91,000~194,000tons) vessels were found to be about 9.0 times, about 6.3 times, and about 8.0 times their own lengths respectively. 4. It is considered to be helpful for the safety of ship handling that the sufficient safe relative distances for every vessels shall be more than about 12~14 times which are 2 times minimum relative distance, their own length on above assumption.
        4,000원
        159.
        1998.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,700원
        160.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Panax ginseng C.A. Meyer has been extensively used in the traditional oriental medicine as a restorative, tonic and prophylatic agent. Petroleum ether extract of panax ginseng C.A. Meyer (GPE) and its several fractions (P1-P5) were tested for the evaluation of antigenotoxicity against N-methyl-N-nitrosourea (MNU) and benzo(a)pyrene [B(a)P]-induced micronucleated reticulocytes in mouse peripheral blood. GPE and P2 showed more significant anticlastogenicity than other fractions did. To elucidate the anticlastogenic action mechanism of GPE and P2 against B(a)P, the alteration of B(a)P metabolism was studied. GPE and P2 inhibited B(a)P metabolism in the presence of S-9 mix and decreased B(a)P-DNA binding in calf thymus DNA with S-9 mix. They also decreased [3H] MNU induced DNA binding and methylation to 7-methyl guanine and O^5-methyl guanine adducts in calf thymus DNA by HPLC analysis. These results suggest that the anticlastogenicity of GPE and P2 on the B(a)P or MNU-induced clastogenicity is due to decrease of DNA binding with B(a)P or MNU, the inhibition of metabolism with B(a)P and the inhibition of methylation in DNA. Therefore, GPE and P2 may be useful chemopreventive agents of alkylating agent like MNU and secondary carcinogen like B(a)P.
        4,000원