• 한국연초학회지
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• 제3권1호
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• pp.41-48
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• 1981

Dihaploid lines were derived from the anthers of the F, of single cross, "Va 115" x"SC 72" (Nicotiana tabacum L.). The path-analysis, correlation coefficient, and variation of characteristics among dihaploid families were evaluated. Dihaploid lines displayed much greater variation than their parents. The genetic correlation coefficient between yield and total alkaloids of dihaploids was significantly lower than that of conventional varieties and lines. In path-analysis which relates yield components to yield, number of leaves harvested and leaf width had a direct effect on yield. a direct effect on yield.

• Journal of Animal Science and Technology
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• 제58권2호
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• pp.8.1-8.14
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• 2016

In this research data representing 72,946 primiparous cows from 724 herds with 638,063 total test day records calved between 2001 and 2011. These data were analysed to determine the effect of age at first and season of calving on parameters of the Wood lactation curve. Also, genetic trend of the lactation curve parameters in different calving years were evaluated. The results indicate that the highest rate of atypical lactation curve was related to cows that calved in summer (28.05 %). The maximum phenotypic relationship between initial milk yield and total 305-d milk yield was observed in cows calved in spring (0.40). The role of peak yield is more than peak time on 305-d total milk yield in primiparous Holstein. One month increase in age at first calving from 18 to 26 month raised 305-d milk yield by around 138 kg and from 27 to 32 month decreased by 61 kg. The persistency of lactation between 101 and 200 days is higher than that of 201-305 days. Our results indicate that the shape of lactation curve is largely dependent on the season of calving (higher level of milk production in cows which calved in autumn and winter). The heritabilities of parameters of lactation curve and persistency measures were low. The genetic trends for peak time, peak yield and 305-d milk yields were positive and estimated to be 0.019, 0.021 and 8.13 kg/year respectively. So the range from 24 to 26.5 month of calving is the optimum calving time in primiparous Holstein for maximizing 305-d milk yield.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.1044-1052
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• 2015

The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.

• 한국작물학회지
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• 제66권4호
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• pp.411-418
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• 2021

파종시기를 달리하여 참깨 수량구성요소 및 종실수량에 미치는 영향과 수량구성요소 간 상호 연관성을 구명하고자 2019부터 2020년까지 수행하였으며, 그 결과를 요약하면 다음과 같다. 1. 참깨를 만파하면 기본적인 생육량이 확보되지 않은 상태에서 생식생장으로 전환되어 초장, 분지수, 주당삭수의 감소로 궁극적으로는 총 종실 수량이 감소하였으며, 조파 시 저온으로 인한 유효적산온도 및 일조시간 확보 불충분으로 총 종실 수량이 줄어드는 경향을 보였다. 2. 우리나라 기상조건에서 참깨 파종적기인 5월 상순에 파종하면 평균 주당삭수는 103개로 다른 파종기보다 4~44개 정도 많았으며 종실수량도 90 kg/10a으로 다른 파종 기대비 5~70 kg정도 많았다. 3. 회귀분석을 통한 참깨 수량구성요소의 종실수량에 대한 연관성 정도를 비교하여 본 결과 주당삭수가 가장 크게(R²=0.7211) 나타났으며 분지수(R²=0.1896)가 가장 적었다. 이러한 차이는 온도나 일장 등 재배환경에 대한 수량구성요소의 감응도 차이, 관련요인 간 상호작용, 공시품종의 일장 및 온도반응성 정도 등 복합적인 요인이 관여하는 것으로 판단되었다. 4. 경로분석을 통해 참깨 총 종실수량에 미치는 직접효과는 주당삭수 0.621, 초장 0.521, 천립중 0.086 순으로 크게 나타났다. 직접효과와 간접효과를 합한 총 효과는 주당삭수가 0.921로 가장 높았으며 초장 0.889, 분지수 0.482, 천립중 0.345 순으로 나타났다. 따라서 조파, 만파 시 불량 기상환경조건에서 주당삭수를 많이 확보할 수 있는 품종 선정이 필요할 것으로 판단되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권7호
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• pp.915-921
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• 2006

Various random regression models with different order of Legendre polynomials for permanent environmental and genetic effects were constructed to predict future milk yield of Holstein cows in Korea. A total of 257,908 test-day (TD) milk yield records from a total of 28,135 cows belonging to 1,090 herds were considered for estimating (co)variance of the random covariate coefficients using an expectation-maximization REML algorithm in an animal mixed model. The variances did not change much between the models, having different order of Legendre polynomial, but a decreasing trend was observed with increase in the order of Legendre polynomial in the model. The R-squared value of the model increased and the residual variance reduced with the increase in order of Legendre polynomial in the model. Therefore, a model with $5^{th}$ order of Legendre polynomial was considered for predicting future milk yield. For predicting the future milk yield of cows, 132,771 TD records from 28,135 cows were randomly selected from the above data by way of preceding partial TD record, and then future milk yields were estimated using incomplete records from each cow randomly retained. Results suggested that we could predict the next four months milk yield with an error deviation of 4 kg. The correlation of more than 70% between predicted and observed values was estimated for the next four months milk yield. Even using only 3 TD records of some cows, the average milk yield of Korean Holstein cows would be predicted with high accuracy if compared with observed milk yield. Persistency of each cow was estimated which might be useful for selecting the cows with higher persistency. The results of the present study suggested the use of a $5^{th}$ order Legendre polynomial to predict the future milk yield of each cow.

• 한국환경과학회지
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• 제16권12호
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• pp.1319-1324
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• 2007

A tank model in conjunction with Kalman filter is developed for prediction of sediment yield from an upland watershed in Northwestern Mississippi. The state vector of the system model represents the parameters of the tank model. The initial values of the state vector were estimated by trial and error. The sediment yield of each tank is computed by multiplying the total sediment yield by the sediment yield coefficient. The sediment concentration of the first tank is computed from its storage and the sediment concentration distribution(SCD); the sediment concentration of the next lower tank is obtained by its storage and the sediment infiltration of the upper tank; and so on. The sediment yield computed by the tank model using Kalman filter was in good agreement with the observed sediment yield and was more accurate than the sediment yield computed by the tank model.

• 한국연초학회지
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• 제9권1호
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• pp.3-10
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• 1987

This study was conducted to investigate the effects of plant density and urea supplement on the yield, quality, value and total nitrogen, alkaloid contents of burley tobacco leaves. The results were as fellows; As urea supplement were increased from 0kg/10a to 50kg/10a, yield, total alkaloid, total nitrogen of cured leaf were significantly increased. The lower plant density levels also increased dry weight and leaf area per plant. Price of cured leaves were not influenced by plant density and amounts of urea supplemented. The effects of plant density and urea supplement on the number of leaves were not detected.

• 한국식품영양과학회지
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• 제28권6호
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• pp.1408-1411
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• 1999

In order to investigate the appropriate processing season of ark shell(Scapharca subcrenata) cultured at the south coast of Korea, the edible portions were determined for coefficient of fatness and yield of edible portion using specimens collected bimonthly from December 1994 to December 1995. The relationship between shell length(X) and total weight(Y) of S. subcrenata is shown as follows; Y=0.001608X2.5199. The relationship between total weight(X) and meat weight(Y) of S. subcrenata is shown as follows; Y= 0.3594X 0.5566(r=0.99). The relationship between total weight(X) and meat weight(Y) of S. subcrenata is shown as follows; Y=67.1647X＋20.6370(r=0.99). The coefficient of fatness and yield of edible portion showed a marked bimonthly variation with a maximum in December and a minimum in August. The appropriate processing season of S. subcrenata would be in winter and spring, and not in summer and autumn season, the spawning season of the S. subcrenata.

• 식품보건융합연구
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• 제4권2호
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• pp.17-23
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• 2018

Carica papaya is an important medicinal plant used in the management of different disease conditions. Phytochemical screening was carried out using different chemical test, Percentage yield and total phenolic content was evaluated using Folin Ciocalteu method in different solvent system; methanol, ethanol, ethyl acetate, n-butanol and n-hexane respectively. The phytochemical screening of the studies showed the presence of flavonoids, saponins, tannins, terpenoids, glycosides, steroids, carbonhydrate, anthraquinone and alkaloids. The percentage yield of crude extract and total polyphenol content was high in methanol, ethanol and ethyl acetate when compared with n-butanol and n-hexane. The studies show that Carica papaya leave extracts is a potent source of secondary metabolites. The use of the plant in the management of diseases is justified.

• 한국초지조사료학회지
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• 제15권4호
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• pp.279-284
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• 1995

The competition relationship between orchardgrass(Docflis glomerutu L. cv; Potomac) and red clover (Trifnlium prurense L. cv; Kenland) was investigated under the pure and mixed swards. Each species were grown in intra- and interspecific competition in pots and fields for 2-years. Intra- and interspecific competition were evaluated by calculating traditional methods; expected yield, relative yield total(RYT), aggressivity and compensation index(CI), and shoot and root dry matter production in the orchadgrass(ffi) pure, red clover(RC) pure and orchardgrdss(W)-red clover(RC) mixed sward. The results obtained were summarized as follows: Compared to OG and RC pure swards, the shoot and root dry maaer(DM) yield of OG-RC mixed sward were higher and more deeply rooted under the soil than those of OG and RC pure sward. Also, the number of tillen per plant of OG in the OG-RC mixed sward was less than that of OG pure sward, but that of RC in the OGRC mixed sward was more than that of RC pure sward. OG-RC mixed sward were evaluated as a productive sward type compared to OG and RC pure swards in that actual yield was higher than expect yield and that relative yield total(RYT), and compensation index(C1) were high. As mentioned above, compared to intraspecific competition as a OG and RC pure sward, interspecific competition as a OG-RC mixed sward was evaluated to productive type under the ffi and RC species utilization