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        검색결과 876

        581.
        2003.08 구독 인증기관 무료, 개인회원 유료
        In this study, the control perfomances of Tuned Mass Damper (TMD) and Tuned Liquid Column Damper (TLCD) are evaluated and compared for seismically excited structures. Results show that TLCD is more effective than TMD for interstory drift control while TLCD is as effective as TMD for acceleration control. In special, it is shown that interstory drifts are maximally controlled in lower floors and accelerations are reduced most in upper floors. This indicates that TLCD is an effective controller for earthquake-induced structures in terms of structural safety as well as serviceability.
        4,000원
        583.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the factors influencing body mass index of 618 university students located in the Gwangju area, from Nov. 20th to 30th, 2002. The subjects included 301 males(48.7%) and 317 females(51.3%). This survey was conducted using a self-administered questionnaire. The percentage of students who were underweight, normal and overweight based on their body mass index(BMI) was 3.7, 88.0 and 8.3 for the males, and 29, 71 and 0 for the females, respectively. Most students (73.8%) skipped breakfast. This was because of lack of time(65.1%) of the cases. Self-reported eating habit problems were eating irregular meal(52.4%), overeating(21%), prejudiced meal(12.4%) and skipping meal(7.4%). The type of favorite snack was biscuit(31.9%) and cup Ramyon(31.9%). The type of favorite beverage was juice(23.3%). The coffee intake was higher in males compared to females. The rates of alcohol drinking in male and female students were 88.0% and 85.8% respectively, and the rates of smoking were 35.9% and 2.8% respectively. Percentages of weight control experience were 30.2 and 51.4 in the male and female, respectively. The BMI of students living in home and eating breakfast was higher than that of the other students. The BMI of students eating cup Ramyon and water increased. The BMI of students taking regular exercise and weight control tended to be higher than that of subjects not doing so. When the amount of pocket money available and the rates of coffee intake, alchol drinking and smoking increased, the BMI was increased. Therefore, nutritional education for university students is needed so as to improve their health and to modify life habits and nutritional education program should be developed to meet the various needs of these students.
        5,100원
        584.
        2003.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        일반적으로 유체-구조물 상호작용을 고려한 유체속 구조물들의 지진 및 진동해석에는 주어진 시스템에 대한 유체부가질량을 추정하여 구조물관 연계하는 단순해석 방법을 주로 사용한다. 실제로 유체속 구조물의 응답특성은 유체부가질량 뿐만 아니라 유체점성으로 인한 감쇠영향을 받으며 이들은 모두 연계항을 갖는 복잡한 행렬 형태로 나타난다. 본 연구에서는 비점성 및 점성 유체에 대한 Navier-Stokes 지배방정식의 선형화를 통한 유한요소 정식화를 유도하였다. 이를 이용하여 유한요소 해석 프로그램을 작성하고 6각형 단면특성을 갖는 액체금속로 노심에 대하여 덕트집합체 사이의 유체간격과 레이놀즈수 변화에 따른 유체부가질량과 유체감쇠에 대한 유한 요소 해석을 수행한 결과, 유체간격이 줄어들수록 유체부가질량은 유체점성의 영향을 크게 받고 유체감쇠는 점성으로 인하여 레이놀즈수의 영향을 크게 받는 것으로 나타났다. 또한 편심을 갖는 동축원통에 대한 유한요소 해석결과, 편심이 증가할수록 유체부가질량은 크게 증가하지만 유체감쇠는 편심이 작은 경우 거의 변화가 없으며 어느 일정 수준이상으로 편심이 커질 경우에는 크게 영향을 받는 것으로 나타났다.
        4,000원
        585.
        2002.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Five contemporary pre-main sequence (PMS) evolution model grids are compared with the photo-metric data for a nearly complete sample of low-mass members in NGC 2264. From amongst the grids compared, the models of Baraffe et al. (1998) prove to be the most reliable in mass-age distribution. To overcome the limited mass range of the models of Baraffe et al. we derived a simple transformation relation between the mass of a PMS star from Swenson et al. (1994) and that from Baraffe et al., and applied it to the PMS stars in NGC 2264 and the Orion nebula cluster (ONC). The resulting initial mass function (IMF) of the ONC shows that the previous interpretation of the IMF is not a real feature, but an artifact caused by the evolution models adopted. The IMFs of both clusters are in a good agreement with the IMF of the field stars in the solar neighborhood. This result supports the idea proposed by Lada, Strom, & Myers (1993) that the field stars originate from the stars that are formed in clusters and spread out as a result of dynamical dissociation. Nevertheless, the IMFs of OB associations and young open clusters show diverse behavior. For the low-mass regime, the current observations suffer from difficulties in membership assignment and sample incompleteness. From this, we conclude that a more thorough study of young open clusters is necessary in order to make any definite conclusions on the existence of a universal IMF.
        4,300원
        588.
        2002.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of the this study was to investigate the dietary behavior and the food habits of university freshman according to body mass index. Questionnaire were completed by 532 students in university freshman. The data were analyzed by SAS program. The results were as follows : The means of normal group's height, weight were 175.00±5.98cm, 72.93±10.20kg for male students and 162.00±4.75cm, 51.97±4.98kg for female students. Under 20 of BMI(body mass index) among students were 69.7% for male and 9.6% for female. Twenty~twenty five(20~25) of BMI were 21.9% for male and 40.2% for female. The consumption of milk, oil and animal fat were significant according to BMI. There was high significant difference in the score of exercise and activity. In the self recognition of body shape 59.0% of male and 52.6% of female in normal weight group answered that their weight had to be a little thin. Self satisfaction rate was significantly higher in under weight group compared to normal weight group. This study suggest that a comprehensive nutrition education program is need for university students to improve desirable food habits and recognition of rate of figure.
        4,300원
        589.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        곤충병원성 선충인 Steinernema carpocapsae All (ScA)과 포천(ScP) 계통, S.glaseri NC (SgN)와 동래(SgD) 계통, Heterorhabditis bacteriophora NC 1 계통(HbN)이 당근뿌리혹선충 (Meloidogyne hapla)의 난낭 형성에 미치는 영향을 구명하기 위하여 토마토를 이용한 pot실험을 수행한 결과는 다음과 같다. 450마리의 당근뿌리혹선충이 있는 100g 토양에 곤충병원성 선충을 2.5 마리 농도로 처리한 결과 ScA처리에서 9.4-36.5개, SgN처리에서 5.7-24.7개, HbN처리에서 11.2-16.0개로서 당근뿌리혹선충 단독 처리에서의 62.5개보다 난낭수가 매우 적었다. Steinernema선충을 100㎤당 100마리, 200마리의 당근뿌리혹선충에 대해 2,020마리/토양 350g와 1.6 마리 농도로 처리한 결과 Steinernema 선충의 종간, 계통별 또는 처리농도 간에는 난낭수의 차이가 없었으나, 당근뿌리혹선충 단독 처리와 비교하면 난낭수가 현저히 감소하였다 곤충병원성 선충을 당근뿌리혹선충 처리 3일 전에 처리한 것이 3일 후에 처리한 것보다 난낭 형성 억제에 더 효과적이었다. 한편, 곤충병원성 선충은 토마토의 생육에 아무런 영향을 끼치지 않았다.
        4,000원
        591.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, vertical acceleration of center of mass was observed along normal gait phases in 9 healthy male volunteers (aged ). The developed wireless accelerometric device was attached on the intervertebral space between L3 and L4 using a semi-elastic waist belt. A three-dimensional motion analysis system, synchronized with the accelerometry, was used for detecting gait phases. There was no significant correlation between the body weight and the acceleration. The first peak curve covered loading response phase. The second downward peak point was matched accurately with the opposite toe-off. In mid-stance and terminal stance, the acceleration curve highly resembled the vertical ground reaction force curve. There was no significant difference in timing between the final upward peak point and the initial contact. Therefore, the developed accelerometry system would be helpful in determining determine temporal gait pattems in patients with gait disorders.
        4,000원
        592.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a method that estimates stiffness and mass matrices of shear building from modal test data is presented. This method applied of building depends on the number of measurement points that are less in number than the total structural degrees of freedom, and on the first two orders of structural mode measured. By means of this method it is possible to use modal data of unmeasurable points to estimate total stiffness and mass matrices of structure. Some examples are studied in this paper, and its result shows that this method is reliable.
        4,000원
        594.
        2001.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        현재 국내에서 개발중인 액체금속로 원자로구조물의 내진설계 및 지진해석을 위하여 원자로내부에 존재하는 유체-구조물 상호작용을 고려한 단순지진해석 모델링 개발이 필수적이다. 이를 위하여 본 논문에서는 유체속에 잠긴 동축원통 구조물의 유체부가질량에 대한 이론적 배경을 검토하였으며 기존의 유체부가질량법을 고려하여 시간이력 지진응답해석을 수행할 수 있는 Runge-Kutta 수치해석 알고리즘을 사용한 해석코드를 개발하였다. 개발된 지진해석코드를 사용하여 유체속에 잠긴 두개의 동축원통 구조물의 진동특성과 지진응답에 대한 유체부가질량의 영향을 살펴보았다. 적용예로서 두개의 동축원통에 대한 단순지진해석모델을 가정하고 유체부가질량을 고려한 진동특성해석과 지진응답해석을 수행한 결과 유체가 채워진 동축원통 구조물은 유체와의 상호작용으로 인하여 구조물의 진동특성과 지진응답특성이 크게 영향을 받으며 지진응답해석시 연계항을 포함한 유체부가질량의 영향을 신중하게 고려할 필요가 있는 것으로 나타났다.
        4,000원
        597.
        2001.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CTA ester bonds in TG molecules were not attacked by pancreatic lipase and lipases produced by microbes such as Candida cylindracea, Chromobacterium viscosum, Geotricum candidium, Pseudomonas fluorescens, Rhizophus delemar, R. arrhizus and Mucor miehei. An aliquot of total TG of all the seed oils and each TG fraction of the oils collected from HPLC runs were deuterated prior to partial hydrolysis with Grignard reagent, because CTA molecule was destroyed with treatment of Grignard reagent. Deuterated TG (dTG) was hydrolyzed partially to a mixture of deuterated diacylglycerols (dDG), which were subsequently reacted with (S)-(+)-1-(1-naphthyl)ethyl isocyanate to derivatize into dDG-NEUs. Purified dDG-NEUs were resolved into 1, 3-, 1, 2- and 2, 3-dDG-NEU on silica columns in tandem of HPLC using a solvent of 0.4% propan-1-o1 (containing 2% water)-hexane. An aliquot of each dDG-NEU fraction was hydrolyzed and (fatty acid-PFB ester). These derivatives showed a diagnostic carboxylate ion, (M-1)-, as parent peak and a minor peak at m/z 196 (PFB-CH3)- on NICI mass spectra. In the mass spectra of the fatty acid-PFB esters of dTGs derived from the seed oils of T. kilirowii and M. charantia, peaks at m/z 285, 287, 289 and 317 were observed, which corresponded to (M-1)- of deuterized oleic acid (d2-C18:0), linoleic acid (d4-C18:0), punicic acid (d6-C18:0) and eicosamonoenoic acid (d2-C20:0), respectively. Fatty acid compositions of deuterized total TG of each oil measured by relative intensities of (M-1)- ion peaks were similar with those of intact TG of the oils by GLC. The composition of fatty acid-PFB esters of total dTG derived from the seed oils of T. kilirowii are as follows; C16:0, 4.6 mole % (4.8 mole %, intact TG by GLC), C18:0, 3.0 mole % (3.1 mole %), d2C18:0, 11.9 mole % (12.5 mole %, sum of C18:1Ω9 and C18:1Ω7), d4-C18:0, 39.3 mole % (38.9 mole %, sum of C18:2Ω6 and its isomer), d6-C18:0, 41.1 mole % (40.5 mole %, sum of C18:3 9c,11t,13c, C18:3 9c,11t,13r and C18:3 9t,11t,13c), d2-C20:0, 0.1 mole % (0.2 mole % of C20:1Ω9). In total dTG derived from the seed oils of M. charantia, the fatty acid components are C16:0, 1.5 mole % (1.8 mole %, intact TG by GLC), C18:0, 12.0 mole % (12.3 mole %), d2-C18:0, 16.9 mole % (17.4 mole %, sum of C18:1Ω9), d4-C18:0, 11.0 mole % (10.6 mole %, sum of C18:2Ω6), d6-C18:0, 58.6 mole % (57.5 mole %, sum of C18:3 9c,11t,13t and C18:3 9c,11t,13c). In the case of Aleurites fordii, C16:0; 2.2 mole % (2.4 mole %, intact TG by GLC), C18:0; 1.7 mole % (1.7 mole %), d2-C18:0; 5.5 mole % (5.4 mole %, sum of C18:1Ω9), d4-C18:0 ; 8.3 mole % (8.5 mole %, sum of C18:2Ω6), d6-C18:0; 82.0 mole % (81.2 mole %, sum of C18:3 9c,11t,13t and C18:3 9c,11t,13c). In the stereospecific analysis of fatty acid distribution in the TG species of the seed oils of T. kilirowii, C18:3 9c,11t,13r and C18:2Ω6 were mainly located at sn-2 and sn-3 position, while saturated acids were usually present at sn-1 position. And the major molecular species of (C18:2Ω6)(C18:3 9c,11t,13c)2 and (C18:1Ω9)(C18:2Ω6)(C18:3 9c,11t,13c) were predominantly composed of the stereoisomer of sn-1-C18:2Ω6, <..
        5,400원
        598.
        2001.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 지반 기진력을 받는 5층의 시험 구조물의 전동 레벨을 줄이기 위해 AC 서보모터를 이용한 복합 질량 감쇠기를 설계 및 제작하여, 5층의 시험구조물을 랜덤 및 지진 파형으로 가진하였을 때의 복합 질량 감소기와 동조 질량 감쇠기의 효과 및 제어 성능을 실험을 통해 비교 분석하였다. 이를 통해 복합질량 감쇠기는 동조 질량 감쇠기에 비하여 특히 과도 상태의 지진이 구조물의 2개 모드 이상을 동시에 가진할 경우에 구조물의 진동을 줄임에 훨씬 더 유용함을 확인하였다.
        4,000원
        599.
        2001.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        총채벌레류의 토착천적인 Orius strigicollis Poppius의 사육에 영향을 주는 부화율, 산란수 및 산란시기, 사육용기 당 암컷 성충의 밀도와 내적자연증가율을 광주기 16L:8D, 상대습도 10%, 온도 의 사육조건에서 조사하였다. 부화율과 알기간은 각각 88.5%, 5.7일이었다. 사육용기 당 산란수는 50-100개일 때에 우화율이 50.8%로 가장 좋았고, 새로 얻은 성충의 회수시기는 산란 후 17일이 적당하였다. 사육용기 당 암컷 성충의 밀도와 새로 얻은 성충의 수와의 관계는 Y= -10.7971n(X)+44.659(=0.7619)와 같았다. 사육실에서 대량으로 사육하는 경우 일세대 평균기간(T), 순번식율( )과 내적자연증가율( )은 각각 26.5일, 6.18과 0.0687이었다.
        4,000원