• 한국정보처리학회논문지
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• 제6권3호
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• pp.773-780
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• 1999

In this paper, we explore a behavioral animation of artificial birds that have lived by doing an aggregate motion. We first model individual birds and then propose a behavioral model for an aggregate motion of a flock of birds. In order to represent realistically collision avoidance and flock centering among birds, which are necessary properties in a flock of birds, we consider motive of a flock of birds, and role, velocity, momentum, banking and internal characteristics of each bird. The paper presents the simulation result of the proposed model for a flock of 100 birds.

• 한국가금학회지
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• 제7권1호
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• pp.43-51
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• 1980

본 연구는 산란계에 있어 일령에 따른 수정율 및 부화율의 변화상을 조사하여 실용적인 중란생산기간을 구명함과 동시에 성비가 조절된 품종을 육성하기 위한 기초연구로서 일령에 따른 성비의 변화 및 성비와 경제형질간의 상관관계를 추정하고자 실시하였으며 백색레그혼 순종 248수의 165-262일 령까지의 7회 부화성적과 500일령까지의 주요경제형질에 대한 성적을 이용하여 분석한 결과는 다음과 같다. 1) 수정율 90%이상을 얻을 수 있는 실용적인 중란생산 기간은 7개월령이후가 적합한 것으로 사료된다. 2) 성비 40%이하군이 성비 60%이상군보다 수정율 및 부화율이 높은 경향을 나타냈다. 3) 성비 60%이상군이 성비 40%이하군보다 일영에 따른 성비의 변이폭이 컸다. 4) 체중과 란중에 있어서는 성비 60%이상군이 산란지수에 있어서는 성비 40%이하군이 좋은 성적을 나타냈다. 5) 성비 60%이상군에서 성비와 산란지수간에 빈의 상관이었으나 성비 40%이하군에서는 정상관이었다.

• 대한수학회지
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• 제39권4호
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• pp.653-664
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• 2002

This article discusses a new representation of the generalized Fisher flocks and shows that there is a unique flock for each full field K of odd or zero characteristic that has a full field quadratic extension. It is also shown that partial flock extensions of 'critical linear subflocks'are completely determined.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.14.1-14.12
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• 2018

Background: Sheep production is a major component of the livestock sector in Ethiopia. The country owing to the large population of 30.70 million estimated numbers of sheep in the country and out of which about 72.14% are females, and 27.86% are males with diverse genetic resources. The real value of indigenous breeds was often under-estimated mostly due to their poor appearance and relatively low productivity. Developing countries in most cases opt for exotic breeds to increase animal productivity through crossbreeding or breed substitution without properly investigating the production potential of the indigenous breeds. The main objective of the research was to identify sheep flock composition and structure, farmers' traits of interest and breeding objective of Wollo highland sheep, and their $F_1$ crossbreed progenies. Results: Smallholder farmers' flock synthesized from breeding ewes, breeding rams, pre-weaned ewe lambs, pre-weaned ram lambs, unproductive ewes, castrated and fattened rams, with the percentage coverage of 29.2, 13.3, 15.5, 16.5, 12.4, and 12.5%, respectively. The maximum number of flock size was 289.0 sheep per flock and higher in the third stratum. The off-take rate percentage of the three strata presented as 21.9% in 1st stratum, 12% in the 2nd stratum, and 16.4% in the 3rd stratum and higher off-take rate recorded in the first stratum. Sheep producer's traits of interest ranked by growth rate (first), body size (second) and marketing value was third rank. Communal breeding (random mating), village based controlled breeding, mixed type and private ram controlled breeding practice were comprised of 39.7, 61.7, 52 and 71.3%, respectively. The percentages of ewes per flock composition were presented as 36.5, 27.1 and 25.5%, respectively in the 3rd stratum, 2nd stratum and 3rd stratum in the order of their importance's. Conclusion: Genetic improvement practices at smallholder sheep producers situation was showing promising outcome with indigenous Washera $F_1$ crossbred lambs and which designated for weaning rate, body size, marketing age, age at first lambing, good temperament and large litter size in the order of their rank. The contemporary breeding practice tendency indicated that, reduced flock size to improve flock productivity via crossbreeding practices.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.408-415
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• 1997

Data from 5,311 ewes and 13,076 lambing from 1977 through 1994 were used to analyse both annual and cumulative outputs in terms on total number of lambs born, total lamb weight weaned and total wool produced per ewe for ewe longevity 1 to 8 depending on their productive life in the flock. Ewes at Khushab produced 0.08 more lambs per parturition than ewes at Khizerabad; however, 0.39 less lambs were weaned at Khushab than at Khizerabad. Similarly, cumulative number of lambs born was more at Khushab flock than Khizerabad flock (p < .01). However, total weight of lambs weaned was greater at Khizerabad than Khushab flock (p < .01) for each ewe longevity. Most ewes (35%) were sold/replaced just after their first parturition (i. e. ewe longevity 1). The overall mean for annual sale/replacement was 32 and 23% at Khushab and Khizerabad, respectively. Distribution of growth and reproductive traits from 1977-94 did not show upward or downward trend inspite of heavy sale/replacement except yearly variation. Lack of any genetic progress over the year suggested that random breeding was employed without any scientific selection programme. Annual means for lambs born, lambs weaned and weight of lambs weaned per ewe present in the flock were the highest for ewe longevity 2 compared with other ewe longevity groups. Relative efficiency in terms of net income was highest for ewe longevity 5 followed by ewe longevity 4 and 6 in both flocks.

• 한국미생물·생명공학회지
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• 제18권4호
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• pp.383-389
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• 1990

Penicillium verruculosum 섬유소 분해효소의 유도물질인 KC-flock 및 cellobiose octaacetate(COA)를 유일한 탄소원으로 포함하는 배지에서 21일간 배양하면서 배양여액 중의 섬유소 분해효소 각 성분의 활성도와 전기영동상의 단백질 양상을 검토하였다. 배양여액의 중의 총단백질 생성 및 섬유소 분해활성의 유도 효과는 COA 배지가 다른 두 배지의 3배 이상이었다. 배양기간의 증가에 따라 배양여액 중의 총단백질량이 증가되었는데 CMC 분해활성이나 $\beta$-glucosidase 활성의 증가보다는 avicel 분해활성도의 증가가 총단백질량의 증가와 유사하다.

• 대한수의학회지
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• 제48권4호
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• pp.457-462
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• 2008

The objective of this study was to determine appropriate sample size that simulated different assumptions for diagnostic test characteristics and true prevalences when designing serological surveillance plan for pullorum disease and fowl typhoid in domestic poultry production. The number of flocks and total number of chickens to be sampled was obtained to provide 95% confidence of detecting at least one infected flock, taking imperfect diagnostic tests into account. Due to lack of reliable data, within infected flock prevalence (WFP) was assumed to follow minimum 1%, most likely 5% and maximum 9% and true flock prevalence of 0.1%, 0.5% and 1% in order. Sensitivity were modeled using the Pert distribution: minimum 75%, most likely 80% and maximum 90% for plate agglutination test and 80%, 85%, and 90% for ELISA test. Similarly, the specificity was modeled 85%, 90%, 95% for plate agglutination test and 90%, 95%, 99% for ELISA test. In accordance with the current regulation, flock-level test characteristics calculated assuming that 30 samples are taken from per flock. The model showed that the current 112,000 annual number of testing plan which is based on random selection of flocks is far beyond the sample size estimated in this study. The sample size was further reduced with increased sensitivity and specificity of the test and decreased WFP. The effect of increasing samples per flock on total sample size to be sampled and optimal combination of sensitivity and specificity of the test for the purpose of the surveillance is discussed regarding cost.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.606-612
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• 2005

Individual production traits, such as reproduction and mortality rates, are partial measures, but may be used to evaluate the performance of different systems by comparing the rate of flock growth and potential offtake. The productivity of two existing sheep production systems, one extensive, one intensive, was compared with an alternative semi-intensive system. The future flock sizes, offtakes and structures were predicted based on the age structure of the flock and age-specific reproduction, mortality and growth rates. The measurements were illustrated with reference to growth of a sheep flock of different age and sex categories. The flock was in a socalled dynamic situation. During the dry period, the digestible organic matter intake of the animals in the intensive system and both extensive and semi-extensive systems was 36 and 20.1 g kg$^{-0.75}$ d$^{-1}$, respectively. During the cold period, the digestible organic matter intake of the animals in extensive, intensive and semi-extensive systems was 34, 34.5 and 41 g kg$^{-0.75}$ d$^{-1}$, respectively. During the dry period, the animals in the both extensive and semi-intensive systems lost in body weight at a rate of 19 g per day, but the rate of gain in body weight of the animals in intensive system was 57 g per day. During the cold period, the animals in extensive, intensive and semiintensive systems gained in body weight at rates of 56, 67 and 97 g per day, respectively. The higher gain of animals during the cold period in the semi-intensive system was related to a sustained higher intake of low-quality roughage and more efficient use of the available feed. Compared to the intensive system, the annual concentrate input of the semi-intensive system was about 48% lower for each livestock unit. The productivity of the semi-intensive system was higher than that of the extensive system.

• 한국환경생태학회지
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• 제28권5호
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• pp.516-522
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• 2014

본 연구에서는 두루미류의 서식밀도에 영향을 주는 요인 중 인위적 요인에 의한 영향을 평가하고자 하였다. 대상지역은 강원도 철원군의 민간인통제지역이며 2009년부터 2014년까지 매년 1월의 두루미와 재두루미의 분포를 대상으로 하였다. 인위적 요인인 도로, 거주지 및 군사시설로 부터의 거리에 따른 두루미류의 밀도를 파악하였으며, 비닐하우스의 분포밀도 차이에 따른 두루미류의 서식밀도를 평가하였다. 두루미와 재두루미는 동일지점에서 서식밀도 상관관계가 있었기 때문에 인위적 요인에 대해 유사한 민감성을 보이는 것으로 나타났다. 거주지와 가까운 곳은 두루미와 재두루미 모두 낮은 서식밀도를 보였으며, 2.5km 구간까지 거리가 멀어질수록 밀도가 증가하는 양상을 보였다. 이는 군사시설 및 통행량이 높은 도로와 유사한 양상이었으며, 군사시설로 부터는 약 0.8km까지, 통행량이 높은 도로는 2km 구간까지 요인으로부터 멀어질수록 서식밀도가 증가하였다. 이러한 경향은 인가지역과 군사시설 및 통행량이 높은 도로가 두루미류의 서식밀도에 일정범위까지 악영향을 주는 것을 의미하였다. 통행량이 적은 도로와 인접한 곳은 간헐적 간섭으로 먹이자원이 보전되어 있어 밀도가 높은 것으로 판단되었다. 비닐하우스의 밀도가 낮은 곳에서는 밀도가 증가할수록 두루미류의 서식밀도가 감소하는 경향을 보였는데, 비닐하우스의 밀도가 40개/$km^2$ 미만인 경우에서 나타났다. 하지만 비닐하우스의 밀도가 40개/$km^2$ 이상인 지역에서는 뚜렸한 밀도의 감소가 나타나지 않았다.

• 한국가금학회지
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• 제36권2호
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• pp.165-175
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• 2009

국내 실용 산란계 농장에서 FLHS 병력을 지닌 계군과 정상계군에 대한 특정 혈액화학치를 비교 측정하여 다음과 같은 결과를 얻었다. FLHS 계군의 간의 지방 함량과 vacuolation score가 Non-FLHS 계군보다 높게 나타났으며, FLHS를 확인하는데 간의 지방 함량과 조직 병리학적 소견을 평가하는 것이 유의성이 있음을 확인할 수 있었다(p<0.05). 또한, FLHS 계군과 Non-FLHS계군이 실험군으로서 명확하게 구분이 되었다. Non-FLHS와 FLHS 계군의 다섯 가지의 혈액화학치를 측정한 결과, cholesterol, AST, LDH의 평균 수치가 Non- FLHS 계군보다 FLHS 계군이 높았으며, FLHS를 확인하는데 cholesterol, AST, LDH가 유의성 있는 항목임을 알 수 있었다(p<0.05). FLHS 계군은 Non-FLHS 계군보다 CK는 높지 않으면서, AST가 높게 나타났으며, FLHS를 진단하기 위해 AST를 측정할 때, CK를 비교 항목으로 이용하는 것이 유용하다는 것을 확인할 수 있었다. Serum AST는 케이지에서 사육되는 산란계에서 FLHS 발생시 현저하게 상승되는 항목으로, FLHS 계군 중에는 250 IU/L 이상을 보이는 개체가 있었으나, Non-FLHS 계군에는 250 IU/L 이상을 보이는 개체가 없었다. MINITAB을 이용하여 판별 분석을 실시한 결과, AST의 판별 추정 계수가 cholesterol이나 LDH보다 큰 수치를 나타내어, AST가 FLHS의 판별에 더 큰 의미를 부여하는 유용한 항목임을 다시 확인할 수 있었다.