• 한국초지조사료학회지
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• 제14권3호
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• pp.238-246
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• 1994

본 시험은 가을에 파종한 호밀()에 대한 파종시기 및 가을 수확방법이 호밀의 생육특성, 사초수량 및 사료가치에 미치는 영향을 구명하기 위하여 1992년 9월 5일부터 1993년 4월 21일까지 서울대학교 농업생명과학대학 부속시럼목장의 사초시험포장에서 수행되였으며, 가을수확방법으로서 무예취, 가을예취 및 가을 방목을 주구로 하고 파종시기(조기파종;9월 5일, 중기파종;9월 25일, 만기파종;10월 15일)를 세구로 하는 분할구 시험법으로 3반복 설계배치하였으며 그 결과를 요약하면 다음과 같다. 1. 호밀의 출수시작일은 무예취 및 가을방목간에는 3일차이가 있었으나 조기 및 만기파종간에는 6일의 차이가 있었다. 따라서 호밀의 출수시작일에 미치는 가을파종시기의 영향은 가을수확방법보다 더 컸다. 2. 호밀의 CPgkafid은 가을방목구가 16.5%로 가을예취 및 무예취구의 15.6보다 조금 높았으나, 파종기에 따라 호밀의 CP함량은 조기, 중기 및 만기파종이 각각 14.2, 14.5, 19.0%를 보였다. 3. 호밀의 ADF 함량은 가을예취(29.9%)및 무예취구(29.5%)가 가을방목구의 28.0%보다 조금 높았으며 파종기에 따라서는 조기, 중기 및 만기파종이 각각 30.7, 29.1 및 27.7%를 보였다. 또한 가을수확방법 및 파종시기에 따른 호밀의 NDF함량은 ADF함량과 같은 경향을 보여주었다. 4. 호밀의 RFV와 IVDMD는 무예취 및 가을 예취구가 가을방목구보다 낮았으나, 파종기의 경우는 파종이 늦어짐에 따라 증가하였다. 5. 호밀의 건물수량은 가을예취구가 6,779kg/ha로 가장 높았고 무예취구가 6,240kg/ha로 가장 낮았으나 수확방법간에는 유의성이 없었으며 파종기에 따른 건물수량은 파종이 늦어짐에 따라 유의적으로 감소하였다. 본 시험의 결과를 종합하면 호밀은 봄의 1회 수확보다 가을 일찍 파종하여 가을과 봄에 2회 수확하는것이 사초수량이 높았다.

• 한국초지조사료학회지
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• 제38권4호
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• pp.331-336
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• 2018

본 연구는 한우 번식우에 있어서 영양대사물질 분석을 통하여 영양수준을 구명하여 번식우의 수태율 개선을 위한 기초 자료로 활용하기 위해서 실시하였다. 번식우의 정확한 영양수준 분석을 위해서 사료급여량을 80%, 100%, 120%로 구분하여 사양관리를 실시한 결과 Cholesterol과 BUN 농도가 120% 급여구에서 유의적으로 높은 결과를 나타내었다(p<0.05). 방목우 중에서 임신우와 비임신우의 영양대사물질 수준 분석 결과, Cholesterol, AST, NEFA 농도가 임신우에 비해 비임신우에서 유의적으로 높은 결과를 보였다(p<0.05). 이와 같이 임신과 관련한 영양수준 분석에 Cholesterol, AST, NEFA 의 3가지 항목을 설정하는 것이 필요할 것으로 사료된다. 방목과 사사 사육에 대한 결과 분석에서 Glucose 농도는 방목우 84.8, 비방 목우 56.0 mg/dl 으로서 방목우에서 유의적으로 높은 결과를 보였고(p<0.05), Cholesterol 수준은 방목우에서 142.5 mg/dl로서 사사 사육 128.9 mg/dl 보다 유의적으로 높았으며(p<0.05), ALT(34.4 vs 27.1 IU/l)와 NEFA 농도(317.8 vs 160.2 ЧEq/l) 역시 방목우에서 유의적으로 높은 결과를 보였다(p<0.05). 결론적으로, 암소에 사료 급여시 Cholesterol, ALT, NEFA 수준을 낮출 수 있도록 하는 것이 한우 암소의 수태율을 높일 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권5호
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• pp.726-732
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• 2014

The objective of this study was to investigate the effect of maintenance system as well as the effect of Se, Zn, and vitamin E supplementation of ram-lambs on the slaughter value and concentration of mineral elements in the loin muscle of lambs. The experiment was conducted on 72 Polish Merino ram-lambs divided into three groups: group C, indoor with no supplement, 19 lambs; S, indoor with supplement, 23 lambs; G, outdoor with no supplement, 30 lambs. From birth all the lambs were maintained indoor with their dams and then weaned at the age of 8 weeks. The rams from group C and S were placed in individual straw-bedded pens and fattened individually with concentrate mixture offered ad libitum until the age of 16 weeks. The lambs from group G were grazed every day from May to July (2 months). During the fattening period each lamb from the supplemented group S was administered per os 1 mL 0.1% $Na_2SeO_4$ (Se, 0.42 mg), 3 mL 10% $ZnSO_4$ (Zn, 68 mg), and 1 mL premix protect vitamin E (0.1 g ${\alpha}$-tocopherol, 5 mg lysine, 5 mg methionine) daily. A comparison of half carcasses across the groups has shown no difference between the control group and the one with supplements, while the weight of half carcasses in the grazing group was smaller in comparison with groups C and S (p<0.001). The meat content in the pelvic limb showed no differences across all groups under study. The pelvic limb of grazing lambs contained less fat compared to the control and supplemented groups (p<0.001). The concentrations of Se and Zn in the blood plasma of ram-lambs from the supplemented group were significantly higher than for the control and grazing lambs. Inorganic Se and Zn supplementation with vitamin E to the diet of lambs increased Se and Zn levels in loin muscle (p<0.001) to $0.46{\mu}g/g$ and $32.9{\mu}g/g$ in fresh tissue, respectively.

• 한국전자파학회논문지
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• 제29권8호
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• pp.615-623
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• 2018

낮은 관측각에서의 해상 클러터 반사계수의 진폭 확률밀도 함수는 각 클러터 패치별 평균 세기가 서로 다르므로 Rayleigh 분포가 아닌 compound Gaussian 분포로 가정하는 것이 일반적이다. 반사계수를 구성하는 텍스쳐(texture) 성분은 Gamma 분포 및 MNLT(memoryless nonlinear transformation)를 이용해서 발생시키지만, 스펙클(speckle) 성분 시뮬레이션에 대해서는 정형화된 방법은 없다. 수신 신호의 스펙트럼을 Gaussian 형태의 도플러 스펙트럼 형태로 모델링한 후 스펙클 성분을 발생시킨 기존 S. Watt 방법을 소개한 후 본 논문에서 새롭게 제안한 방법을 제시하였다. 제안 방법은 이퀄라이져(equalizer) 필터를 사용해서 인접 클러터 영향을 최소화한 후, 클러터 공분산 행렬에 대해 Cholesky 분해를 통해서 스펙클 성분을 생성하는 방법으로써 제안 방법의 타당성 검증을 위해 시뮬레이션을 통해 도플러 스펙트럼 및 코릴레이션(correlation) 함수 관점에서 제안한 방법과 기존 방법을 비교한다.

• 한국음향학회지
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• 제32권2호
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• pp.95-103
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• 2013

천해에서 수중음향통신은 해면과 해저의 음향특성에 강한 영향을 받는다. 시변적인 해면 산란과 입사각에 좌우되는 해저손실에 의해 수중통신 시스템의 성능은 영향을 받게 되어 고속의 디지털 통신 성능은 저하된다. 우세한 직접파가 존재하면 통신채널은 Rice 페이딩, 그렇지 않은 경우 Rayleigh 페이딩으로 모델링된다. 그러나 실해역의 실험으로 이러한 통계적인 채널 모델링을 검증하는 것은 어려운 연구주제로 알려져 있다. 해면산란과 해저반사 손실이 수중음향통신에 미치는 영향의 근원적인 이해를 돕기 위하여 저자들은 이들의 영향을 정량화하기 위한 천해 해역에서 실험을 수행하였다. 이진 주파수 천이 변조 방식으로 영상을 전송하여 해면산란과 해저 입사각에 좌우되는 해저반사 영향을 송신기와 수신기간의 거리, 수신기 깊이에 따른 영상의 양호성과 비트 오류율로 평가하였다. 결론적으로 영상의 전송 성능은 채널의 일관성 대역폭을 결정하는 송수신기간의 거리 및 수신기의 깊이에 좌우된다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권1호
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• pp.60-67
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• 2000

A survey involving 71 cattle and buffalo farming households under coconut plantations was carried out in three districts (Pannala, Bingiriya and Kuliyapitiya) with the aim of assessing the status of livestock farming. Also, 24 households (eight from each district) were visited monthly for period of one year to collect information on feeding practices. Apart from milk, animals were reared for selling, draught, bio-gas and for manure. Due to difference in system of management of cattle and buffaloes, manure from buffaloes (46%) was more frequently used for coconuts than that from cattle (10%). Majority of cattle were improved breeds (temperate origin) or their crosses, as compared to buffaloes (mainly indigenous). The most predominant management system was tethered grazing during the day, and stall feeding during the night. Coconut land (own or others) and paddy fields were the major grazing areas for the animals. The grass from coconut land was lower in crude protein (8.2%) and digestibility (48%) compared to those from paddy fields (12.1 and 57%, respectively). Of the 288 rations analysed, grass was included in 280 of the daily rations for cattle as compared to 251 for buffaloes. Straw was more commonly included in mixed rations for buffaloes (137 out of 288) than for cattle (53 out of 288). The frequency of use of straw for buffaloes was high in Pannala (75 out of 137 cases). There was wide variation among the improved breeds of cattle and buffaloes in milk production (2 to 9 litres/day), lactation length (6 to 10 months) and calving interval (13-21 months).

• Fisheries and Aquatic Sciences
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• 제24권12호
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• pp.415-427
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• 2021

Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

• Animal Bioscience
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• 제35권1호
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• pp.105-114
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• 2022

Objective: This work was carried out to evaluate the effect of pasture (PA) feeding on buffalo meat quality compared with buffaloes reared intensively with the use of corn silage as a forage base or alternatively with polyphite meadow hay (PH). Methods: Thirty Mediterranean bull buffaloes were distributed into three experimental diet groups: maize silage (MS), PH, and PA. The animals were slaughtered at a live weight of 250 kg, and carcass and meat quality were evaluated. After 7 days of ageing, physical and chemical parameters of longissimus thoracis muscle were determined. To evaluate lipid oxidation the thiobarbituric acid reactive substances was tested at 7 and 14 days, and also the fatty acid profile was recorded by gas chromatography. Results: The PA group, even if it showed carcass parameters lower than those of the silage maize group, reported a good meat percentage (60.59% vs 58.46%, respectively) and lower fat percentage (p<0.001). PA-fed animals showed meat redness, and even if only on raw meat, shear force was higher than the others. Low values of conjugate linoleic acid, polyunsaturated fatty acids, and n-3 were reported in the silage maize group. Principal component analysis (PCA) clearly showed the influence of different diets on meat quality, and PCA1 and PCA2 explained 82% of the variability. Conclusion: Buffaloes reared on PA had meat with high nutritional value even if they showed poor carcass performance compared to the animals fed on MS. Buffaloes fed on polyphite hay were in an intermediate position, similar to grazing animals, according to the same nutritional determinations.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.500-505
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• 2005

This paper introduces an experimental study for the noise characteristics and reduction of a ventilating fan system. For the purpose of noise reduction of it, an absorptive duct silencer filled with a glass fiber has been conventionally utilized. However, a glass fiber has some disadvantages like hygiene and secondary pollution problems. In order to overcome these problems, in this paper, a perforated duct silencer has been applied to the ventilating fan system. For the designing of a perforated duct silencer, the transmission losses for various perforated panel systems are measured and compared with their sound absorption performances.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.181-181
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• 2013

Recently, nanostructure and the molecular orientation of organic thin films have been largely paid attention due to its importance in organic electronics such as organic thin film transistors (OTFTs), organic light emitting diodes (OLEDs), and organic photovoltaics (OPVs). Among various methods, the diffraction and scattering techniques based on synchrotron x-rays have shown powerful results in organic thin film systems. In this work, we introduce the in-situ annealing system installed at PLS-II (Pohang Light Source II) for organic thin films by simultaneously conducting various x-ray scattering measurements of x-ray reflectivity, conventional x-ray scattering, grazing incidence wide angle x-ray scattering (GI-WAXS) and so on. Using the in-situ measurement, we could obtain real time variation of nanostructure as well as molecular orientation during thermal annealing in metal-phthalocyanine thin films. The variation of surface and interface also could be simultaneously investigated by the x-ray reflectivity measurement.