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        검색결과 15

        1.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of dietary total mixed ration (TMR) supplementation and dry-aging period on the physico-chemical and sensory quality of striploin (longissimus lumborum) from multiparous Hanwoo cows. The experimental cows were divided into two treatments (n=3/treatment) according to the type of feed: in one treatment (slaughter age: 87±6 months old, parity: 5±1) the cows were fed on TMR for 7 months before slaughter, while in the other treatment (slaughter age: 83±9 months old, parity: 5±2) the cows were fed on concentrate and rice straw (CRS) for the whole rearing period. After slaughtering, the striploins were dry-aged for 20 or 40 days at 2±1℃, 85% relative humidity and 2 m/sec air flow velocity and then utilized for quality measurements. The pH value, cooking loss, and hypoxanthine content were higher (p<0.05) for the striploins dry-aged for 40 days than for those dry-aged for 20 days. Notably, the inosine 5’-monophosphate content was decreased (p<0.05) by increasing the dry-aging time. With regard to microbiological quality, the striploins dry-aged for 40 days exhibited lower (p<0.05) lactic acid bacteria counts and higher (p<0.05) coliform counts than those dry-aged for 20 days. Moreover, the tenderness and overall liking scores based on sensory evaluation were higher (p<0.05) for the dry-aged striploins of the TMR treatment and those dry-aged for 40 days than for the CRS treatment and those dry-aged 20 days, respectively. These findings suggest that dietary TMR supplementation leads to an increase in the sensory preference of dry-aged striploins from multiparous Hanwoo cows, and alteration of the CRS into the TMR may improve the quality of dry-aged Hanwoo beef.
        4,000원
        2.
        2006.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research we tried to make nano-sized TiNx by using planetary milling, and we made the composites double layered of titanium and nano-sized TiNx by using spark plasma sintering apparatus after mixing with the different ratio of pure titanium powder, and they were heat treated at for 30 minutes. The crystal structures of nano-sized TiNx powders and the composites were analyzed by X-ray diffraction (XRD). The microstructures of the powders were analyzed by using scanning electron microscopy (FESEM) and the 40-50 nm size of nano-sized TiNx particle on the surface of agglomerated particles was investigated. With increasing the ratio of nano-sized TiNx of the composites, the microvickers hardness of the composites was increased.
        4,000원
        3.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The silica nanoparticles were used as support of catalyst, filling material, electronic assembler, thin film material, and sensor material. And, the titania nanoparticles were used as pigment, dielectric substance, sensor and photocatalyst. In this paper, the spherical composite particles of TiO2/SiO2with narrow size distribution and phase pure were synthesized by ultrasonic spray pyrolysis method from TiOSO4 and colloidal silica solution. Using ultrasonic apparatus, this starting solution was vaporized to droplets, and these droplets were induced into tube furnace by carrier gas. The resulting composite powder was characterized by scanning electron microscopy, X-ray diffraction analysis, TG-DTA, in vitro sun protection factor(SPF) and BET surface area analysis.
        4,000원
        4.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 섬유소공급원 7종, alfalfa hay cube (AHC), corn cob (CC), corn silage (CS), cotton seed hull (CSH), peanut hull (PHL), rice straw(RS), sugar cane bagasse(SCB)의 반추위에서의 반추활동, pH, 완충능력과 전소화기관 내 소화율을 알아보고자 실시하였다. 공시 동물은 평균체중 37.1kg인 Corridale종 수 면양 5두 (3두는 반추위
        4,000원
        5.
        2000.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many cultural heritages for the modern ages in Korea are becoming lost rapidly as a result of subsequent technological innovation and changes in industrial structures and other reasons. But they are indispensable for an understanding of history, tradition culture of Korea, and form the basis for development and advancement of future culture at the same time. Therefore, this study is aimed to review the protection of cultural heritage in Japan, establishing the protection policies in Korea. In Japan, The Advisory Committee for the Preservation and Utilization of Modern Cultural heritage was organized by The Agency for Cultural Affairs. And this classified modern cultural heritage into four fields, as like; (1)monuments, (2)buildings, (3)fine arts and historical heritage, and (4)life, culture, and technology to pursue concrete research and study. The next step is tarrying out investigations to identify these cultural heritages, which were once the backbone of Japanese modernization and are now in the process of being lost, in an effort to preserve them as cultural heritage of the Japanese modernization period. The investigation will have conducted on an about eight year scheme starting with 1996. And it's will ask all local boards of education(of the prefectures, cities, towns, and villages throughout the country) to supply all related records or documents available and to cooperate in field studies. So now, many cultural heritages for the modern ages in Japan have been designated as Important Cultural Properties, Registered Tangible Cultural Properties, Monuments, etc. And they have been prepared various tax policy(ex, reduction of the real estate tax). Also, that's examples are not only one by one but magnified with protection of large-scale construction associated with region. In addition, magnified with region's activities. In conclusion, in the process, protection has been extended to a broader variety of cultural properties and much consideration has been given to the methods of protection in Japan.
        4,900원
        6.
        2000.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Alkylation of phenol with tert-butanol in the liquid phase on mordenite was studied. The influence of many reaction parameters such as calcination temperature, reaction temperature, t-butanol/phenol molar ratio on catalytic properties was discussed. The main products were 2,4-di-t-butylphenol, o-t-butylphenol, p-t-butylphenol, the last of these was wanted product. In order to enhance the selectivity of p-t-butylphenol, optimum conditions were recommended at 500℃ calcination temperature, 140℃ reaction temperature, 1.0 molar ratio of reactants over mordenite. P-t-butylphenol was formed with 90% isomer selectivity at optimum conditions after 4hr reaction. On the basis of the behavior obtained in the cases mentioned, optimum conditions and catalytic properties for t-butylation of phenol were provided.
        4,000원
        8.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to infer the plan and location of the government office building in Chongju Castle in the Late Yi-dynasty. The conclusion is as follows: 1. The Chongju Castle Map(淸州邑城圖, late in the 18th century, hereinafter referred to CCM) provides the detail arrangement and location of Government Office Building in Chongju Castle. And the road structure and plan of the CCM is almost same with the present time. 2. As compared with CCM and a Chongju-land Registration Map(淸州面地籍原圖, 1913, CRM) to infer the location of the traditional government office building in Chongju Castle, the building locations of Gaek-Sa(客舍) Donghun(東軒)'s region in CCM are almost accordance with today's. But those of Byungyoung(兵營) Group's region are represented by a little error. So the locations of Byungyoung(兵營) Group's region rearranged, moved down to be in accordance with the approach circulation of Main Gate(閉門樓) which is shown in CRM. 3. The records, on the plan of the traditional government office building in Chongju Castle, have proved that the plan of Gaek-Sa was a width of 11 bay and a depth of 2 bay. A width of 3 bay drawn in CCM, the present plan of Donghun is a width of 7 bay and a depth of 4 bay. The main building and especially the double-storied Main Gate($4{\times}3$ 수식 이미지) of Byungyoung Group are exactly in keeping with the present road structure.
        4,300원
        9.
        1991.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In relation to the preparation of Langmuir-Blodgett thin film, four kinds of N-alkylpyridiniurn bromide were synthesized. The values of surface tensions of these materials, measured with a Traube stalagmometer, gave the relationship between the critical micells hydrophobic radical and between CMC and temperature. Values of thermodynamic properties(δH0m, δS0m, δG0m,) for the formatoin of micelle were also obtained. Experiments gave the following results; at the temperature range between 40 and 60℃, CMC of Hexadecyl-, Octadecyl-, Eicosyl-, and Docosyl-Pyridinium Bromide were 7.64×10-4~9.13×10-4, 3.85×10-4~4.60×10-4, 2.00×10-4~2.39×10-4, and 1.07×10-4~1.28×10-4 mol/l, respectively. Surface tension, γCMC, of those were 33.49~36.00, 34.78~37.61, 35.49~37.61 and 38.76~55.80 dyne/cm, respectively, The relationship between CMC and the mumber of carbon atoms in the hydrophobic radical, N was expressed as follows : Log(CMC)=A-BN where A and B are constants. At the temperature range between 40 and 60℃, the change of Gibbs evergy (δGm) for one methylene group (-CH2-) were -0.65RT, respectively, The minus values of enthalpy change (δHm) suggest that the formation of micelle is exothermic. Additionally, the overall increase in the entropy change (δSm) with respect to the temperature increase suggests that the formation of micelle is attained by a exothermic enthalpy directed process.
        4,000원
        10.
        1990.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A Stability to the dispersion solvent, which is acetonitrile, dichloromethane, benzene, chloroform and acetonitrile-benzene(1:1,v/v) of N-docosyl pyridinium)-TCNQ(1:2)complex was investigated by U.V Spectrophotometer and was confirmed stabilized on acetonitrile, the dichloromethane and acetonitrile-benzene (1:1,v/v) for seven hours. Using CdCl2buffer solution as subphase for LB films deposition, it was achived successively to fabricate the Y-type LB films of (N-docosyl pyridinium)-TCNQ(1:2)complex. For the sake of verifying the deposition of LB films, U.V is measured by variation of nominal layer number.
        4,000원
        11.
        1990.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transesterification reactions (methyl methacrylate with monoethanolamine, methyl methacrylate with n-butyl alcohol, dimethylphthalate with ethylene glycol, dimethyl phthalate with monoethanolamine) were kinetically investigated in the presense of various metal acetate catalysts at 110℃. The amount of reactants was measured by gas and liquid chromatography, and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd, Maximum reaction rates were appeared at the range of 1.4 to 1.6 in electronegativity of metal ions and maximum catalytic activities were obserbed at the range of 1.5 to 1,8 in instability constant of metal acetates.
        4,000원
        12.
        2013.04 KCI 등재 서비스 종료(열람 제한)
        In this study, the use survey of domestic and international weather information on coastal regions and the demand survey (e.g. general and in-depth surveys) for customer needs with coastal industries were carried out to design customized coastal weather contents. The general demand survey showed that most of the customers working in the coastal industries were interested in a short-term forecast, such as a general weather outlook (approximately 29% of the total respondents) and typhoon information (19%), and they preferred to be given the forecast information from new media such as the internet web-pages (36%) and mobile utilities (23%) rather than old media such as TV (16%) and radio (11%). In addition, only 31% of the total respondents were found to be satisfied with the use of the current coastal weather service. This low percentage might mainly be a result of lack of information accuracy (about 64%) and diversity (28%). From in-depth survey with site visiting, the need of coastal weather contents, such as weather elements, data form, a tool of communication, and forecast interval, differed with the working stages in three coastal industries (e.g. shipbuilding, maritime trade, and passenger transport industries).
        14.
        2005.10 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 OFDM 방식의 문제점으로 지적되고 있는 송신단에서의 PAR 특성을 고려하여 고속 적응형 PTS 기법과 SLM 기법을 결합한 SLM-PTS 결합기법을 제안하였다. 또한, PAR 저감기법을 적용한 시스템을 평가하기 위하여 ETD-Turbo 부호를 사용한 COFDM 시스템을 구성한 후 성능을 평가하였다. 분석 결과 제안된 SLM-PTS 기법이 연산량을 경감시키며 전반적으로 우수한 PAR 저감성능을 보임을 알 수 있었다. 특히 Combine 3의 경우 10-5 BER을 기준으로 약 3.7~3.9 dB 정토의 개선된 PAR 성능을 보였다. 또한, 터보부호를 사용한 경우 전반적으로 우수한 PAR 성능을 보임을 알 수 있었고, ETD-Turbo 부호를 적응한 경우 추가적으로 약 0.5 dB 정도의 성능 개선효과가 있음을 알 수 있었다.
        15.
        2005.04 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 OFDM 시스템의 문제점으로 지적되고 있는 송신단의 피크전력 대 평균전력비(Peak to average Power Rate; PAR) 을 고려하여 부호화된 OFDM (Coded OFDM) 시스템을 설계하고 PAR 저감기법을 사용하여 BER (Bit Error Rate)과 SNR (Signal to Noise Ratio) 특성을 평가하였다. 변조방식에 따른 성능 평가를 위하여 M-ary PSK와 M-ary QAM 방식을 비교하였고, 그 결과 16-PSK와 16-QAM 의 성능이 우수하게 나타났다. 또한 16-QAM이 16-PSK 방식보다 10-3의 오차범위에서 2 dB 더 우수한 성능을 보였으며, Peak Power Clipping 기법에서는 약 5dB 정도 우수한 성능을 보였다.