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        검색결과 685

        223.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We adopt the PASTEL catalog combined with SIMBAD radial velocities as a testing standard to validate the stellar parameters (effective temperature Teff , surface gravity log g, metallicity [Fe=H] and radial velocity Vr) from the first data release (DR1) of The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey. After applying data reduction and temperature constraints to the sample obtained by cross-identification, we compare the stellar parameters from DR1 and PASTEL. The results show that the DR1 results are reliable under certain conditions. We derive a dispersion of 110 K, 0.19 dex, 0.11 dex and 4.91 kms-1 in specified effective temperature ranges, for Teff , log g, [Fe=H] and Vr respectively. Systematic errors are negligible except for those of Vr. In addition, for stars with PASTEL [Fe=H] < —1.5, the metallicities in DR1 are systematically higher than those in PASTEL.
        3,000원
        224.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to assess the potential of using NIRS to accurately determine the chemical composition and fermentation parameters in fresh coarse sorghum and sudangrass silage. Near Infrared Spectroscopy (NIRS) has been increasingly used as a rapid and accurate method to analyze the quality of cereals and dried animal forage. However, silage analysis by NIRS has a limitation in analyzing dried and ground samples in farm-scale applications because the fermentative products are lost during the drying process. Fresh coarse silage samples were scanned at 1 nm intervals over the wavelength range of 680~2500 nm, and the optical data were obtained as log 1/Reflectance (log 1/R). The spectral data were regressed, using partial least squares (PLS) multivariate analysis in conjunction with first and second order derivatization, with a scatter correction procedure (standard normal variate and detrend (SNV&D)) to reduce the effect of extraneous noise. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation (SECV). The results of this study showed that NIRS predicted the chemical constituents with a high degree of accuracy (i.e. the correlation coefficient of cross validation (R²cv) ranged from 0.86~0.96), except for crude ash which had an R² cv of 0.68. Comparison of the mathematical treatments for raw spectra showed that the second-order derivatization procedure produced the best result for all the treatments, except for neutral detergent fiber (NDF). The best mathematical treatment for moisture, acid detergent fiber (ADF), crude protein (CP) and pH was 2,16,16 respectively while the best mathematical treatment for crude ash, lactic acid and total acid was 2,8,8 respectively. The calibrations of fermentation products produced poorer calibrations (RPD < 2.5) with acetic and butyric acid. The pH, lactic acid and total acids were predicted with considerable accuracy at R²cv 0.72~0.77. This study indicated that NIRS calibrations based on fresh coarse sorghum and sudangrass silage spectra have the capability of assessing the forage quality control
        4,000원
        225.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ground Level Enhancements (GLEs) in cosmic ray intensity observed during the period of 1997-2012 have been studied with energetic solar features and disturbances in solar wind plasma parameters and it is seen that all the GLEs have been found to be associated with coronal mass ejections, hard X-ray solar ares and solar radio bursts. All the GLEs have also been found to be associated with sudden jumps in solar proton ux of energy of ≥ 60 Mev. A positive correlation with correlation coefficient of 0.48 has been found between the maximum percentage intensity (Imax%) of Ground Level Enhancements and the peak value of solar proton ux of energy (≥ 60Mev). All the Ground Level Enhancements have been found to be associated with jumps in solar wind plasma velocity (JSWV) events. A positive correlation with correlation coefficient of 0.43 has been found between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the peak value of solar wind plasma velocity of associated (JSWV) events. All the Ground Level Enhancements have been found to be associated with jumps in solar wind plasma pressure (JSWP) events. A positive correlation with correlation coefficient of 0.67 has been found between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the peak value of solar wind plasma pressure of associated (JSWP) events and of 0.68 between the maximum percentage intensity (Imax %) of Ground Level Enhancements and the magnitude of the jump in solar wind plasma pressure of associated (JSWP) events.
        4,000원
        226.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The rheological properties of complex materials such as colloid dispersion show complicated non-Newtonian flow phenomena when they are subjected to shear flow. These flow properties are controlled by the characteristics of flow units and the interactions among the flow segments. The rheological parameters of relaxation time (β2)0, structure factor C2 and shear modulus X2/α2 for various thixotropic flow curves was obtained by applying thixotropic equation to flow curves. The variations of rheological parameters are directly related to non-Newtonian flows, viscosities and activation energies of flow segments.
        4,000원
        227.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 지진위험도 산출에서 불확실성을 줄이는 한 방법으로서 지진위험도 계산에 입력되는 파라미터들(a, b값, Mmax, 감쇠식 및 지진지체구조)이 지진위험도 값에 어느 정도로 영향을 미치는지 민감도를 분석하고자 하였다. 이를 위해 지진 전문가 10명이 제시한 입력자료를 사용하였다. 그 결과 a값, Mmax값이 커질수록 PGA값이 증가하였으며, b값은 작아질수록 PGA값이 커졌다. 가장 큰 영향을 미치는 파라메타는 감쇄식, b값 및 a값이며, Mmax와 지진지체구조구 모델의 영향은 상당히 적었다. 따라서 영향이 큰 파라메타에 대해서는 한반도의 지진학적 특성에 적합한 값의 산출이 요구된다.
        4,000원
        228.
        2015.08 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 정소가 제거된 흰쥐에 비타민 E와 셀레늄(Selevit)을 5주간 투여 후 체중, 장기 무게, 혈액학적 그리고 생화학적 변화를 관찰하였다. 체중의 변화에서는 모든 실험군에서 증가가 나타냈다. Orch+Selevit군의 체중 증가는 11.2±10.25 g으로 가장 낮았으며, Intact군, Sham군, Orch군과 비교 시 유의적으로 감소되었다. 장기 무게의 변화에서는 Orch+Selevit군의 심장과 간장 무게는 Intact군, Sham군과 비교 시 유의적으로 감소되었다. Intact군, Sham군, Orch군의 신장 무게는 Orch+Selevit군 비교 시 유의적인 증가를 확인하였다. 백혈구 수의 혈액학적 변화에서는 Orch+Selevit군은 다른 모든 군과 비교해 유의적인 증가를 확인하였으며, 적혈구수, 평균적혈구용적, 평균적혈구혈색소량, 평균적혈구색소농도 등과 같은 혈액학적 측정치에서는 유의성은 인정되지 않았다. 생화학적 변화에서는 Orch+Selevit군의 혈청총단백질, 알부민은 Orch군과 비교 시 유의적으로 증가하였으며, 알부민은 Intact군, Sham군 그리고 Orch군과 비교 시 유의적으로 감소했다. AST와 ALT는 모든 실험군에서 유의성이 없었다.
        4,000원
        229.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전분과 구연산 사이의 다중 에스테르화반응에 의한 starch citrate의 저항전분 함량에 대한 반응압출성형조건들의 영향을 조사하였으며, 이들의 페이스팅 점도 특성을 조사하여 산업적 활용도가 높은 starch citrate를 제조할 수 있는 반응조건을 탐색하였다. 반응압출성형에 의한 starch citrate를 제조하기 위해 성형노즐을 제거한 쌍축압출성형기를 사용하여 반응온도, 스크류 회전속도, 반응혼합물의 쌍축압출성형기 통과횟수를 변수로 하였다. 반응온도가 높아지면서, 스크류 회전속도가 느려지면서, 쌍축압출성형기 통과횟수가 증가하면서 starch citrate의 저항전분 함량은 증가하는 경향을 나타내었다. 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 10 rpm의 쌍축압출성형기를 5회 통과시킬 때 90%의 저항전분을 보유한 starch citrate를 얻을 수 있었다. 또한 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 50 rpm의 쌍축압출성형기를 5회 통과시킬 때 58%의 저항전분을 보유한 starch citrate를 얻을 수 있었으며, 이는 유의적인 페이스팅 점도를 발달시켜 높은 저항전분 함량에도 불구하고 가공적성이 우수한 starch citrate를 얻을 수 있었다. 또한 starch citrate의 제조 시 전통적으로 사용되는 컨백션 오븐 보다는 쌍축압출성형기를 사용하는 것이 가공적성이 우수한 starch citrate를 제조할 수 있을 것으로 보인다. 따라서 본 연구에서 보고한 50%(s.b) 이상의 저항전분을 보유하면서도 페이스팅 점도 특성을 잃지 않은 starch citrate와 쌍축압출성형기를 활용한 starch citrate 제조기법들은 산업적 활용도 높을 것으로 예상되며 기존의 저항전분 소재들을 대체할 수 있는 잠재력이 높은 저항전분 소재일 것으로 생각된다.
        4,000원
        230.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        프리스트레스 콘크리트 정착부의 설계를 위해 AASHTO 및 PTI에서 관련 설계식을 제안하고 있다. 그러나 이러한 설계식은 구조물의 긴장력이 단순 지압판을 통해 구조 전반으로 전달된다는 가정으로 유도된 것으로 실제 구조물에 적용되는 상용 정착구의 형태와는 차이가 있다. 이 논문에서는 하중전달 시험에 의한 실험적 방법과 3차원 고체요소를 사용한 비선형 유한요소해석 프로그램을 이용한 해석적 방법을 통해 정착구의 형상 변수에 따른 정착부의 거동특성 변화에 대한 연구를 수행하였다. 하중전달시험 결과에서 얻어진 하중변위 곡선 및 극한하중 값을 해석을 통해 얻은 결과와 비교하여 유한요소모델의 적합성을 확인하였다. 또한 정착구의 리브의 설치위치, 리브의 개수, 리브의 설치길이를 주요 변수로 설정하여 형상변수에 따른 매개변수 연구를 수행하였다.
        4,000원
        231.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        경포호에서 수질 변수들의 장기적인 경향을 파악하기 위하여 1998년부터 2013년까지 매년 3월부터 11월까지 2개월에 1회씩 3개 지점에서 조사된 15가지 수질변수들과 강우량자료를 이용하였으며, Mann-Kendall test, Sen’s slope estimator 및 linear regression을 적용 분석하였다. 계절 변화 분석에는 Mann-Kendall test 및 Sen’s slope estimator만 이용하였다. 분석결과 염분, 투명도 및 영양염류 (총인, 용존무기인, 총질소, 질산성 질소, 암모니아성 질소)의 변수들만 통계학적으로 유의적인 경향을 보였다. 선형회귀 분석에서는 염분 (표층과 심층의 전 지점)과 투명도 (지점 1)만이 통계학적으로 유의적인 증가 경향을 나타냈으나, 비모수법에 의한 분석에서는 염분과 투명도 모두 전 지점에서 통계학적으로 유의적인 증가 경향을 보였다. 통계학적으로 유의적인 감소 경향을 보인 수질변수들은 선형회귀 분석에서는 용존산소 (표층 지점 1, 심층 지점 2와 3), 총인(지점 1과 2), 용존무기인, 총질소, 질산성 질소 및 암모니아성 질소, 비모수법에 의한 분석에서는 용존산소 (심층 전 지점), 총인, 용존무기인, 총질소, 질산성 질소 및 암모니아성 질소였다. 계절적인 경향을 분석한 결과 봄에는 염분, 탁도, 투명도 및 부유물질 (SS), 여름에는 염분, 투명도, 질산성 질소 및 부유물질, 가을에는 수온, 염분, 투명도 및 부유물질 만이 증가하는 경향을 보였으며 이들 변수들이 계절에 따라 다소 차이를 보이는 것으로 나타났다. 특히 봄과 여름에 비해서 가을철에 Mann-Kendall test 및 Sen’s Slope estimator에 의해 유의적인 경향을 나타낸 수질변수들이 많았다. 가장 강한 증가 경향을 보인 것은 염분이었으며 봄보다는 여름과 가을에 뚜렷하였다. 투명도도 염분과 유사한 특성을 보였다. 강우량은 조사기간 동안 전체적으로 감소하는 경향을 보였다. 경포호에서 영양염류의 유의적인 감소경향은 그동안 강릉시에서 추진해온 석호 복원사업 및 해수유통 (수중 보 철거) 등과 관련이 있는 것으로 판단되나 정확한 원인 규명을 위해서는 보다 면밀한 조사가 수반되어야 할 것으로 사료된다.
        4,500원
        232.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to estimate the genetic and phenotypic parameters of litter size and birth weight traits in three Korean black goat lines (Dangjin, Jangsoo and Tongyung) raised at the Animal Genetic Resources Station (AGRS) of the National Institute of Animal Science (NIAS). A total of 1,861 records collected from 2001 to 2013 were used for analyses with single trait animal models. The average litter size of Dangjin line was the largest (1.72 kids) and the average birth weight of Jangsoo line was the heaviest (1.88 kg) among the three lines. Heritability estimates of litter size and birth weight were 0.07 and 0.26, respectively. The average breeding value of litter size and that of birth weight of Jangsoo line were the greatest of all three lines, 0.15 heads and 1.88 kg, respectively. The correlation coefficients between phenotypic values and breeding values of litter size in the lines of Dangjin, Jangsoo and Tongyung were 0.054, -0.031 and 0.131, respectively. The correlation coefficients between phenotypic values and breeding values of birth weight in the lines of Dangjin, Jangsoo and Tongyung were 0.570, 0.454 and 0.521, respectively. The phenotypic correlation and breeding value correlation between litter size and birth weight were 0.031 and 0.003 in Dangjin line, -0.038 and 0.094 in Jangsoo line, and 0.109 and 0.121 in Tongyung line, respectively. These data suggest that the genetic parameters estimated for litter size and birth weight in this study could be used to improve genetic potentials of Korean black goats in industrial level
        4,000원
        233.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This work introduces a modal testing and analysis results of the mock-up for a layered stone pagoda. The pagoda has been horizontally excited by an impact hammer. As to the measured acceleration time responses, the first five lower mode shapes and natural frequency are extracted by the TDD technique. It is observed that the time delay of a shear wave occurs through friction surfaces. Such phenomena cannot be described by using the traditional analytical models such as a continuum cantilever beam model or a discrete shear building model. However, the time delay typically affects only the phases of the pagoda system. The frequencies of the pagoda system are not affected by such time delay. It is found in the first time that the layered stone pagoda system has a set of closely placed modes in near of natural frequency. It is believed that such modes are due to the friction characteristics in friction surfaces. Based on the stick-slip friction model, it seems that the one of the closely placed mode can be a self-excited one.
        4,000원
        234.
        2015.04 구독 인증기관·개인회원 무료
        Frankliniella occidentalis (Pergande) is an anthophilus pest of many greenhouse and field crops worldwide. We compared the influence of constant (27.3ºC) and fluctuating temperatures (23.8 to 31.5ºC, with an average of 27.3ºC) on the life table characteristics of F. occidentalis held at a 16:8 h L:D photoperiod and 45 ± 5% RH. The development times from egg to adult of F. occidentalis were significantly affected by temperature fluctuation and sex. Survival of immature life stages was higher under fluctuating than constant temperature. Total first instar larvae/female was not significantly different (58.7 at constant and 60.5 at fluctuating temperatures) but daily production of first instars was higher in constant temperature than fluctuating temperatures (3.3 at constant temperature and 3.1 at fluctuating temperatures). The off-spring sex ratio was not significantly different between constant and fluctuating temperatures. The intrinsic rate of natural increase (rm), net reproductive rate (R0), finite rate of increase (λ), mean generation time (tG), and doubling time (tD) were affected significantly by fluctuation of temperature. The intrinsic rate of natural increase of F. occidentalis was higher in constant temperature (0.1808) than did in fluctuation of temperatures (0.1733). Thus, this study show that variable temperatures influence population growth rates of F. occidentalis.
        235.
        2015.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recent large scale surveys such as Sloan Digital Sky Survey have produced homogeneous samples of multiple-image gravitationally lensed quasars with well-defined selection effects. Statistical analysis on these can yield independent constraints on cosmological parameters. Here we use the image separation statistics of lensed quasars from Sloan Digital Sky Survey Quasar Lens Search (SQLS) to derive constraints on cosmological parameters. Our analysis does not require knowledge of the magnification bias, which can only be estimated from the detailed knowledge on the quasar luminosity function at all redshifts, and includes the consideration for the bias against small image separation quasars due to selection against faint lens galaxy in the follow-up observations for confirmation. We first use the mean image separation of the lensed quasars as a function of redshift to find that cosmological models with extreme curvature are inconsistent with observed lensed quasars. We then apply the maximum likelihood test to the statistical sample of 16 lensed quasars that have both measured redshift and magnitude of lens galaxy. The likelihood incorporates the probability that the observed image separation is realized given the luminosity of the lens galaxy in the same manner as Im et al. (1997). We find that the 95% confidence range for the cosmological constant (i.e., the vacuum energy density) is 0.72 ≤  ≤ 1.0 for a flat universe. We also find that the equation of state parameter can be consistent with −1 as long as the matter density m . 0.4 (95% confidence range). We conclude that the image separation statistics incorporating the brightness of lens galaxies can provide robust constraints on the cosmological parameters.
        4,000원
        236.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        두 개의 형질 사이에 유전상관이 존재하면 제 1의 형질을 선발함으로써 다른 중요한 형질의 간접선발도 가능해 진다. 따라서 부분육 형질 중 선호도가 높은 안심과 등심에 대한 생산량 증대를 위해서 생체 상태에서 부분육과 상관도가 높은 체형형질을 발굴하여 개량함으로써 고가이며 선호도가 높은 안심과 등심 등의 생산량을 높일 수 있을 것이라 사료된다. 분석에 이용한 데이터는 1998~2012년도에(23~53차) 후대검정한 5,001두의 후대검정우 자료이며 조사형질로는 대분할육 10개의 형질과 18개월령 체형형질을 이용하였다. 유전모수 추정은 WOMBAT 6.0 software package를 이용하여 실시하였다. 분석에 이용된 모형은 부분육 중량의 경우 도축일을 범주형 변량으로 도축 전 생체중을 공변량으로 하였으며 체형형질의 경우에는 차수, 출생지 및 검정소를 범주형 변량으로 측정일령을 공변량으로 하였다. 분석 결과 안심, 등심 및 갈비중량의 유전력은 각각 0.53, 0.50 및 0.14로 나타났다. 등심과 안심은 체고, 십자부고 및 곤폭과 유전상관이(0.34~0.53) 비교적 높게 나타났으므로 이러한 체형형질을 간접선발 함으로써 선호되는 부위의 생산량을 늘릴 수 있을 것이라 사료된다.
        4,000원
        237.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to estimate genetic parameters for 18 linear conformation traits and overall conformation score in Holstein cattle. A total of 376,606 records for type traits were collected from 2001 to 2011 from Korea Animal Improvement Association. The model of estimation of variance components and correlations among lactations using VCE included both fixed effects (herd-year-season and stage of lactation parity-wise) and random effect (animal additive genetic). The estimated heritabilities (h2) for capacity class, such as stature, chest width, body depth, angularity, and body condition score were 0.32, 0.16, 0.27, 0.12, and 0.19, respectively. Rump angle and width from rump class also showed h2 of 0.31 and 0.17, respectively. The heritabilities in udder class were mostly low to medium; in which traits were fore udder attachment (0.13), rear udder height (0.17), udder support (0.11), udder depth (0.33), front teat placement (0.17), front teat length (0.21), and rear teat placement (0.21). For feet and legs composite class, the estimated heritabilities for rear leg set, foot angle, rear leg rear view, and locomotion were 0.12, 0.07, 0.08, and 0.03, respectively. The h2 estimated for overall conformation score was 0.16 in the study. The genetic and environmental variance components estimated from this study would be helpful to change from single lactation animal models to multiple lactation animal models in the national genetic evaluation system for the improvement of linear type traits. Moreover, The breeding values obtained using these variance components would be able to be used in the calculation of Korean type production index (KTPI), udder composite (UDC) and, feet and legs composite (FLC).
        4,000원
        239.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is imperative to know the reproductive parameters of the existing swine breed for profitable farming in Bangladesh. This study was designed to determine the reproductive parameters of sows at hilly areas. A total of 245 pigs with 47 breedable sows were included. The data on age at puberty, oestrous cycle length, oestrus duration, gestation length, interval between furrowing and onset of oestrus, first service pregnancy rate, service per pregnancy and number of piglets born per sow in local and cross bred sows were determined. The present study revealed that age at puberty of local and cross breed sows was 232.5±8.4, 221.3±6.9 days, respectively. Oestrous duration was 41.1±3.1 hours. The interval between furrowing and onset of oestrus was shorter in cross bred sows. There was no variation in values of oestrus cycle length and gestation length. The first service pregnancy rate was higher in both the local and cross bred sow. Number of piglets per sow per farrowing was 6.1±2.2 and 60.9% local sows gave birth of 3 to 5 piglets per farrowing whereas 75.0% cross bred sows gave birth of 6 to 9 piglets. These results suggest that reproductive parameters of local sow need to be improved for better production, and cross bred sows should be reared for obtaining expected productivity.
        4,000원
        240.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to explore the accuracy of near infrared spectroscopy (NIRS) for the prediction of chemical and fermentation parameters of whole crop winter rye silages. A representative population of 216 fresh winter rye silages was used as database for studying the possibilities of NIRS to predict chemical composition and fermentation parameters. Samples of silage were scanned at 1 nm intervals over the wavelength range 680~2,500 nm and the optical data recorded as log 1/Reflectance (log 1/R) and scanned in fresh condition. NIRS calibrations were developed by means of partial least-squares (PLS) regression. NIRS analysis of fresh winter rye silages provided accurate predictions of moisture, acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP) and pH as well as lactic acid content with correlation coefficients of cross-validation (R2cv) of 0.96, 0.86, 0.79, 0.85, 0.82 and 0.78 respectively and standard error of cross-validation (SECV) of 1.89, 2.02, 2.79, 1.14, 1.47 and 0.46 % DM respectively. Results of this experiment showed the possibility of NIRS method to predict the chemical parameters of winter rye silages as routine analysis method in feeding value evaluation and for farmer advice.
        4,000원