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        검색결과 910

        261.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        부재 교차 결합부 조건에 따른 초기강성은 고정 조건인 경우와 비교하여 반고정 조건인 경우 33% 작게 나타났으나 부재 교차 결합부 특성에 의하여 재하지점과 3m 떨어진 지점에서는 9% 크게 나타났다. 즉, 고정 조건인 경우 구조물 전체로 하중이 분산되어 재하지점과 떨어진 지점에서는 상대적으로 반고정 조건 구조물의 강성이 높게 나타났다. 기초 조건에 따른 초기 강성은 강관 삽입 기초의 경우에는 고정기초 조건과 비교하여 31% 크게 나타났으며, 휨강성은 20% 높게 나타났다. 인터페이스 요소(beam interface element, BIE) 및 지반요소(3-D solid element)를 사용하여 재하시험 결과를 기반으로 각종 계수를 산정하고 시험조건과 동일하게 수치모델링하여 유한요소해석을 수행한 결과 실험결과와 유사한 구조거동을 나타냈다. 그러나 극한하중 조건에서는 비선형 특성의 발현 등에 의하여 다소 상이한 결과 값을 보였다. 이상의 결과로부터 플라스틱 필름 온실의 설계 및 구조성능 평가에서 절점 및 지점 조건에 대한 임의 또는 과다한 이상화는 구조물의 성능 평가에 적지 않은 영향을 줄 수 있음을 알 수 있었다. 한편 플라스틱 필름 온실은 세장한 부재로 구성된 유연한 철골 구조물이므로 구조성능 산정에 있어서 좌굴과 함께 대변형 및 지반의 비선형 특성 등을 충분히 고려해야 할 것으로 판단된다.
        4,000원
        262.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 흑염소 비육에 있어서 조사료원이 볏짚 단용인 경우 농후사료 급여수준이 흑염소의 사료섭취량, 체중변화, 도체특성 및 경제성에 미치는 영향을 구명하기 위하여 실시하였다. 비육 흑염소 40두를 공시하여 농후사료 급여수준을 체중의 1.5% (T1), 2.0% (T2, 농가관행), 2.5% (T3) 및 자유채식구(T4)로 나누어 급여 하였고 조사료는 볏짚을 자유채식 시켰으며그 결과는 다음과 같다. 볏짚인 조사료 섭취량은 농후사료 급여수준이 증가 할수록 감소하였으며, 흑염소의 일당증체량은 체중대비 농후사료 급여수준 1.5, 2.0, 2.5% 및 자유채식구가각각 22, 50, 69 및 94 g으로 농후사료 급여수준이 증가할수록 유의적으로 증가하였다(p <0.05). 비육 흑염소의 도체율은 농후사료 급여수준을 체중비 1.5, 2.0, 2.5% 및 자유채식 시켰을 때 각각 41.77, 42.78, 46.12 및 49.78%로농후사료 급여 수준이 증가할수록 증가하였으며(p<0.05), 지방률도 농후사료 급여수준이 증가 할수록 유의적으로 증가하였다. 경제성 분석에서는 농후사료 급여수준이 증가할수록 소득은 증가하였으며, 자유채식구가 두당 34,270원으로 가장 소득이 높았다. 이상의 결과를 종합적으로 고려할 때 조사료 자원이 볏짚 단용일 경우 비육 흑염소의 농후사료 급여 수준은자유채식 시키는 것이 사료이용성, 발육, 도체율 및 경제성에서 가장 유리할 것으로 사료되며, 흑염소의 비육을 위한 조사료 자원으로서볏짚 단용은 농후사료비의 가중을 가져오므로앞으로는 흑염소 비육을 위한 새로운 조사료자원의 개발이 필요하다고 하겠다.
        4,000원
        263.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 토마토 재배에 적합한 규격을 가지면서 기상재해에 안전한 토마토 재배용 연동 비닐하우스를 설계하였다. 토마토 하우스의 규격은 폭 7m, 측고 4.5m, 동고 6.5m이다. 1995년에 농촌진흥청에서 개발한 1-2W형 하우스와 비교해서 폭은 같지만 측고는 1.8m, 동고는 2m 더 높다. 중방은 작물하중과 장치하중을 견딜 수 있도록 트러스 구조로 설계하였다. 토마토 하우스는 높으면서도 내재해 설계 기준(MIFFAF, 2010)에 맞게 만들어졌다. 즉, 최고 설계 기준인 풍속 40m·s-1, 적설 40cm 이상에 안전하도록 구조안전성 분석을 통해 하우스 기둥, 서까래 등의 부재 규격과 설치 간격을 설정하였다. 1-2W형 하우스와 달리 토마토 하우스에는 랙-피니언 타입의 천창을 용마루 부분에 설치하여 외부 공기 유입과 자연 환기를 극대화할 수 있도록 하였다. 하우스 높이가 증가하면 난방비는 증가하므로 토마토 하우스에는 보온력이 우수한 다겹 보온커튼을 설치하여 하우스 바깥으로 빠져나가는 열을 최소화하였다.
        4,000원
        264.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Preservation, distribution and share of regional genetic resources are one of the hot topics of international debates. Korean government under National Institute of Animal Science (NIAS) supervision made a law that initiated national management system of livestock genetic resources in agriculture and fishery (July, 2012). NIAS preserve domestic livestock genetic sources of Chikso (Korean brindle cattle), Heugu (Korea black cattle), native pig and native chicken under the strategies of multiple place guardians to keep these minor animals from getting extinct through various reasons. A total of around 3,300 animals are under protection currently. Around 70,000 germ cells of Chikso, Heugu, native goat, etc, are stored by cryopreservation method. Moreover,around 30,000 samples of whole blood and DNA are stored in deep freezers. NIAS also constructed Animal Genetic Resource Information Management System (AGRIMS) and stored information including the phenotypes and genotypes of livestock genetic resources. We also have built companionships with nine provincial livestock institutes and two universities regarding rare livestock animal management since 2008. These companion organizations have around 16,000 animals of 11 breeds in their custody. Internationally, we keep on registering these breeds on FAO and Domestic Animal Diversity Information System (DAD-IS) database systems. Recently we updated registration of 24 breeds of six species such as Chikso, Chookjin Chamdon, Ginkkoridak, Jindo, etc.
        4,000원
        265.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the influence of parity on chemical composition and meat quality of Hanwoo cows (n=74, 2-15 years old). The beef loin and top round muscle samples were obtained and divided by 3 groups of parity numbers (G1, 0; G2, 1-3; G3, 4-9 times). Loin and top round from G1 had significantly higher intramuscular fat contents and lower protein contents than those from G3 (p<0.05). There was no significant difference in collagen contents among 3 parity groups (p>0.05). In meat color, G1 was higher in a* values for loin and higher in L* and a* values for top round muscle (p<0.05). The loin from G1 had significantly lower cooking loss (%) than G3, however, there was no significant difference in water holding capacity among 3 parity groups. For top round muscle, G3 had significantly higher Warner-Bratzler shear force values and lower water holding capacity values than G1 (p<0.05). In fatty acid composition, G1 had significantly higher C18:1n7 and C18:1n9 contents for loin, and it had significantly higher C16:1n7 and C18:1n7 contents for top round than those of the other groups (p<0.05). In free amino acid composition, alanine was highest and followed by glutamine, phenylalanine, isoleucine, proline, glycine, methionine. In conclusion, the parity conditions influenced on chemical composition and meat quality depending on different cut of Hanwoo cows, and the parity numbers were related with the age of cows.
        4,000원
        266.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This paper aims to improve the evaluation method of the Level of Service(LOS) for urban streets presented by the current Korean Highway Capacity Manual(KHCM) and suggest its utilization plan as a part of the methods to evaluate the sustainability of a transportation policy. METHODS : This paper carried out a research in 3 steps to develop a new evaluation method. First of all, this paper reviewed the previous studies related to the LOS of urban streets and the socially requested items for a sustainable transportation system. Then this paper derived an index and weight through expert questions to select an evaluation index. Lastly, this paper compared the results according to the existing evaluation methods with the new evaluation methods through case studies. This paper used an Analytic Hierarchy Process(AHP) for importance analysis and weight selection between new evaluation items and indices, and applied a Grey System Theory(GST) for a synthetic and integrated evaluation between the selected evaluation indices. RESULTS : As a result of evaluating the LOS according to the existing evaluation methods and the integrated evaluation methods using a GST through case studies, it was analyzed that new methods' results are less than or equal to the existing evaluation methods; and as a result of applying a weight between evaluation indices according to AHP, it was noticed that the total score seems to rise more when the LOS in the existing evaluation is calculated lower. It was analyzed that the LOS calculated by reflecting the newly established evaluation items and the importance between indices in this study has difference from the LOS of the existing urban streets. CONCLUSIONS : It is expected that this evaluation method can diagnose the current conditions when establishing a future sustainable traffic system and can be used for the measurement of the sustainability effects of the improvement plans and so on.
        4,000원
        279.
        2012.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the effects of redox reaction on preparation of high purity α-alumina from selectively ground aluminum dross. Preparation procedure of the α-alumina from the aluminum dross has four steps: i) selective crushing and grinding, ii) leaching process, iii) redox reaction, and iv) precipitation reaction under controlled pH. Aluminum dross supplied from a smelter was ground to separate metallic aluminum. After the separation, the recovered particles were treated with hydrochloric acid(HCl) to leach aluminum as aluminum chloride solution. Then, the aluminum chloride solution was applied to a redox reaction with hydrogen peroxide(H2O2). The pH value of the solution was controlled by addition of ammonia to obtain aluminum hydroxide and to remove other impurities. Then, the obtained aluminum hydroxide was dried at 60˚C and heat-treated at 1300˚C to form α-alumina. Aluminum dross was found to contain a complex mixture of aluminum metal, aluminum oxide, aluminum nitride, and spinel compounds. Regardless of introduction of the redox reaction, both of the sintered products are composed mainly of α-alumina. There were fewer impurities in the solution subject to the redox reaction than there were in the solution that was not subject to the redox reaction. The impurities were precipitated by pH control with ammonia solution, and then removed. We can obtain aluminum hydroxide with high purity through control of pH after the redox reaction. Thus, pH control brings a synthesis of α-alumina with fewer impurities after the redox reaction. Consequently, high purity α-alumina from aluminum dross can be fabricated through the process by redox reaction.
        4,000원
        280.
        2012.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the comparison of transferable embryos and pregnancy rate between Hanwoo and Chickso. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on Hanwoo 78%, and Chickso 85%, respectively. The mean number of total embryos are each 14.76± 2.16 and 6.23±1.07. So the mean number of transferable embryos are each 10.94±1.91 and 4.58±1.05. In addition, the mean number of total Hanwoo embryo from <10 and 10≤ of corpora luteum was 0.50±0.50, 11.56±1.92, respectively. In case of Chickso, The mean number of transferable embryo from <10 and 10≤ of CL was 2.75±1.39, 6.00±1.00, respectively. The pregnancy rates were Hanwoo 40%, and Chickso 37% following transfer of fresh embryos produced in vivo. Also, the pregnancy rates of Chickso 60% were significantly greater (p<0.05) than the Hanwoo 42.48% following transfer of following transfer of frozen embryos, respectively. In conclusion, these results suggest that Chickso may be effectively used for transferable embryos production in Hanwoo. Although the transferable embryos number was not enough, it seems the Chickso greatly affect pregnancy rate. The results indicated that the possibility of transferable embryos from Chickso for embryo transfer could be confirmed in this study. Based on the present findings, it was suggested that it is very important to evaluate in vivo embryo production and pregnancy rate of embryo transfer following superovulation for effective Hanwoo and Chickso production.
        4,000원