• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1004-1007
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• 2005

As a new approach to analyze grinding energy, this paper introduces a specific grinding energy model based on the average grain. Using this model, grinding characteristics such as specific grinding energy of SM45C were investigated with changing variables such as grain size of CBN, workpiece velocity(v) and apparent depth of cut(Z) in down-surface grinding. From the experimental results, the specific grinding energy decreases as the maximum undeformed chip thickness increases.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.151-157
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• 2005

Sheep production is affected by genetic and non-genetic factors. A knowledge of these factors is essential for efficient management and for the accurate estimation of breeding values. The objective of this study was to establish the non-genetic factors which affect birth weight and weaning weight in Dorper, Mutton Merino and indigenous Sabi sheep breeds. A total of 2,625 birth and weaning weight records from Grasslands Research Station collected from 1991 through 1993, were used. The records were collected from indigenous Sabi (939), Dorper (807) and Mutton Merino (898) sheep. A mixed classification model containing the fixed effects of year, birth status and sex was used for identification of non-genetic factors. Sire within breed was included as a random effect. Two factor interactions and three factor interactions were important in indigenous Sabi, Mutton Merino and Dorper sheep. The mean birth weights were 4.37${\pm}$0.04 kg, 4.62${\pm}$0.04 kg and 3.29${\pm}$0.04 kg for Mutton Merino, Dorper and Sabi sheep, respectively. Sire had significant effects (p<0.05) on birth weight in Mutton Merino and indigenous Sabi sheep. Year of lambing had significant effects (p<0.05) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep. The effect of birth status was non significant in Dorper and Mutton Merino sheep while effect of birth status was significant on birth weight in indigenous Sabi sheep. In Indigenous Sabi sheep lambs born as singles (3.30${\pm}$0.05 kg) were 0.23 kg heavier than twins (3.07${\pm}$0.05 kg), in Mutton Merino lambs born as singles (3.99${\pm}$0.08 kg) were 0.07 kg heavier than twins (3.92${\pm}$0.08 kg) and in Dorper lambs born as singles (4.41${\pm}$0.04 kg) were 0.02 kg heavier than twins (4.39${\pm}$0.04 kg). On average males were heavier than females (p<0.05) weighing (3.32${\pm}$0.04 kg vs. 3.05${\pm}$0.07 kg) in indigenous Sabi, 4.73${\pm}$0.03 kg vs. 4.08${\pm}$0.05 in Dorper and 4.26${\pm}$0.07 kg vs. 3.66${\pm}$0.09 kg in Mutton Merino sheep. Two way factor interactions of sire*year, year*sex and sex*birth status had significant effects (p<0.05) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep while the effect of year*birth status was non significant on birth weight in Indigenous Sabi sheep. The three way factor interaction of year*sex*birth status had a significant effect (p<0.01) on birth weight in indigenous Sabi and Mutton Merino. Tupping weight fitted as a covariate had significant effects (p<0.001) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep. The mean weaning weights were 17.94${\pm}$0.31 kg, 18.19${\pm}$0.28 kg and 14.39${\pm}$0.28 kg for Mutton Merino, Dorper and Indigenous Sabi sheep, respectively. Effects of sire and sire*year were non significant on weaning weight in Dorper and Mutton Merino while year, sex and sex*year interaction had significant effects (p<0.001) on weaning weight. On average males were heavier than females (p<0.001) at weaning. The respective weaning weights were 18.05${\pm}$0.46 kg, 18.68${\pm}$0.19 kg, 14.14${\pm}$0.15 kg for males and 16.64${\pm}$0.60 kg, 16.41${\pm}$0.31 kg, 12.64${\pm}$0.32 kg for females in Mutton Merino, Dorper and Indigenous Sabi sheep. Lambs born as singles were significantly heavier at weaning than twins, 0.05 kg, 0.06 kg and 0.78 kg for Mutton Merino, Dorper and Indigenous Sabi sheep, respectively. Effect of tupping weight was highly significant on weaning weight. The three way factor interaction year*sex*birth status had a significant effect (p<0.01) on weaning weight. Correction for environmental effects is necessary to increase accuracy of direct selection for birth weight and weaning weight.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.489-493
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• 2003

Reproductive traits of sows are determined chiefly by the genetic background of the dam herself. Whether the breed of the serviced boars also contributes is not yet clear. A total of 8,946 litters of Landrace (L) sows from 68 farms were examined. Of these, 876, 1,260, and 6,810 litters were produced from natural mating with L, Yorkshire (Y), and Duroc (D) breeds, respectively. The birth litter size (BLS), weaning litter size (WLS), live born piglets (LBP), and survival rate % (SR), of every litter were recorded. A general linear-model procedure was followed to estimate the effects of boars' breed (B), parity (P) and B${\times}$P interaction on the reproductive traits of the sows. Results show that BLS, WLS, and LBP were all significantly (p<0.001) affected by B and P. SR% was significantly influenced by B but not by P. L sows crossbred with Y or purebred with L produced litters with higher BLS, WLS, and LBP values than those bred with D. Pure L breeding yielded litters with lower SR% than did crossbreeding with D, while the difference between SR% due to LY and that due to LD crossbreeding was not significant. The interaction of B with P was significant with respect to BLS, WLS, and LBP (p<0.001), but not SR%. No significant B effect on reproductive traits was measured in sows at their first parity; but at latter parities, LL or LY produced litters with similarly high BLS, WLS and LBP, which values were all significantly greater than those of LD litters. The breed of boar evidently affected the subsequent reproductive performance of L sows and this effect may be further manipulated by the parity effect. Breed differences in semen quality and the success of fetus development with different interactions of the genetic background with the uterus function of the sow that may contribute to these effects are discussed.

• 한국수정란이식학회지
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• 제20권3호
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• pp.255-269
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• 2005

축산연구소에서 사육중인 비거세우와 거세우를 대상으로 혈청내에 있는 호르몬 및 대사물질 농도가 채혈시기, 사육지역, 거세 여부 등에 따라 어떻게 변하며 경제형질과 어느 정도 상관이 있는지 그리고 이들에 대한 유전변이의 크기는 어느 정도이며 이들의 유전상관계수는 어느 정도인지를 파악하기 분석한 결과는 다음과 같다 1. 혈청 호르몬 및 대사물질의 분산분석 결과 testosterone과 globulin을 제외한 나머지 혈청성분은 사육지역에 따라 차이가 있었고 출생년도 및 계절에 따라 차이가 나타나는 혈청성분 cortisol, total protein, globulin 및 creatinine을 제외한 혈청들이었고 거세 여부에 따라 차이가 있는 혈청들은 total protein과 BUN을 제외한 혈청들이었으며 그리고 tstosterone을 제외한 나머지 혈청들은 종모우의 영향을 비교적 크게 받는 것으로 나타나 종모우의 효과가 인정되므로 이들 성분들의 농도 변이에 상가적 유전자 작용이 어느 정도 관여하고 있음을 시사한다. 2. 도체 형질은 도체중과 등지방두께 및 육량지수는 사육 지역의 효과가 인정되나, 도체율, 근내지방도, 배최장근단면적, 생체중 및 수송 감량은 $5\%$수준에서 유의성이 인정되지 않았다. 종모우의 효과는 대부분의 형질에서 유의적인 효과가 있었고 특히 도체율과 근내지방도에는 큰 영향을 미치는 것으로 나타났다. 3. 월령별 체중을 분산분석 결과 사육지역의 효과는 9개월령을 제외한 모든 연령에서 체중에 대한 유의적인 영향을 미쳤고, 거세 여부는 6개월령 체중을 제외한 나머지 월령별 체중에 대해 유의적인 영향을 미쳤으며, 종모우효과는 모든 월령별 체중에서 유의적인 영향을 미쳤다. 4. 혈청 성분 농도들의 사육연도, 계절 및 거세여부별 최소자승평균치는 대관령에서 사육한 소는 남원에서 사육한 소들에 비해 testosterone 농도가 낮았으나 유의성은 인정되지 않았고, 거세우는 비거세우에 비해 cotisol과 creatinine 및 triglyceride농도가 높았고 IGF-1 및 glucose농도가 낮았으며 testosterone 농도는 비거세우의 약 $5.2\%$에 불과했다. 5. Sire Model을 적용하여 제한 최대우도법으로 추정한 혈청성분의 유전력은, 0.07${\~}$0.58 범위로 추정되었는데 이중 단백질 성분인 total protein, albumin 및 globulin의 유전력은 각각 0.53, 0.54 및 0.42로 비교적 높았고 cotisol과 creatinine 및 BUN은 각각 0.45, 0.58 및 0.54로 높게 추정된 반면 calcium은 0.07, testosterone 0.15 및 IGF-1은 0.12로 아주 낮은 편이었다. 6. 도체 형질에 대한 유전력은 도체중 0.39, 등 지방두께 0.45, 육량지수 0.30 및 배최장근단면적 0.13으로 추정되었으나 근내지방도는 0.93으로 아주 높게 추정되었다. 월령별 체중에 대한 유전력은 18개월령 0.78, 12개월령 0.76, 9개월령 0.62, 6개월령 0.58, 24개월령 0.58 순위였고 기간별 일당 증체량의 유전력추정치는 6${\~}$12개월령이 0.80, 12${\~}$18개월령이 0.75, 그리고 18${\~}$24개월령은 0.19로 육성기와 비육전기에 비해 비육말기는 유전력 추정치가 낮았다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.575-579
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• 2000

First lactation records of 683 Murrah buffaloes maintained at NDRI, Karnal which were progeny of 84 sires used for comparing the heritability estimates of age at first calving, first lactation milk yield and first service period under single and multiple trait models using restricted maximum likelihood (REML) method of estimation under an individual animal model. The results indicated that the heritability estimates may vary under single and multiple trait models depending upon the magnitude of genetic and environmental correlation among the traits being considered. Therefore, a single or multiple trait model is recommended for estimation of variance components depending upon the goal of breeding programme. However, there may not be any advantage of considering a trait with zero or near zero heritability and having no or very low genetic correlation with other traits in the model. Lower heritability estimates of part lactation yield (120-day milk yield) implied that there may not be any advantage of considering this trait in place of actual 305-day milk yield, whereas, comparable heritability estimates of predicted 305-day milk yield suggested that it could be used for sire evaluation to reduce the cost of milk recording under field conditions.

• 국제교류와 융합교육
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• 제4권1호
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• pp.35-56
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• 2024

이 연구는 중국 의무교육단계 학생 부담경감 최신정책 '쌍감'정책을 중심으로 Kingdon의 정책흐름모형을 활용하여 정책의 흐름을 분석하였다. 데이터의 직관적인 반영, 현행 정책의 피드백 등으로 문제의 흐름을 구성하였다. 중국 정부의 높은 관심, 정치협상회의 위원과 전문가의 건언, 학교 현장과 이해관계자의 강한 요구 등은 정책대안의 흐름을 구성하였다. 집권당의 집권 이념과 교육 지침, 국민 정서, 전환기 이익 게임 등은 정치의 흐름을 구성한 것이다.문제의 흐름,정책대안의 흐름, 정치의 흐름 세 가지 흐름이 결합되어 '정책의 창'이 열리게 된 것으로 분석되었다.

• Journal of Animal Science and Technology
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• 제49권2호
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• pp.171-176
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• 2007

본 연구에서는 생산성이 인정된 모돈 F1(YL)에 종료웅돈(Terminal Sire)으로 Duroc종 이외에 생산성 저하에 많은 영향을 미치지 않을 것으로 판단되는 최종 종료웅돈(Terminal Sire) Berkshire종과 Berkshire×Duroc(F1)을 YL(♀) 교배시켜 생산된 비육돈(YLD, YLB, YLBD)의 성장과 육질을 비교 분석 하였다. 성장형질에서는 YL(♀)×BD(♂)가 YL(♀)×D(♂)보다 우수하였으며, 조사된 성장형질 전체에서 유의적인 차이(p<0.05)를 보였다. 육질에서도 pH, 보수력, 육색이 다른 비육돈 보다 유의적으로(p<0.05) 우수하였고, 돼지 육질의 표준이 되는 등심조지방 함량에서 YL(♀)×BD(♂)가 유의적으로 우수하였다. 교배조합별 육색에서는 YL(♀)×BD(♂)가 대체로 명도와 적색도가 높았으며, 지방산 조성에 있어서는 불포화 지방산의 비율이 높은 것으로 나타났다. 따라서, 성장형질에서는 YL(♀)×BD(♂)가 비교 대상의 교배조합에 비해 우수하였으며, 육질에서도 YL(♀)×D(♂) 보다 좋거나 같아 비육돈 교배조합(YLBD)으로서의 이용가치가 있을 것으로 사료된다. 하지만 본 연구의 경우 경남 첨단양돈연구소의 계통조성이 완료된 American Berkshire종을 이용하여 경남의 경우 경남 첨단양돈연구소를 활용하여 별도의 비용이 없이 YLBD를 생산이 가능하겠으나, 다른 지역의 경우 Berkshire의 계통 조성하여 활용할 경우 기존의 종료웅돈 Duroc종을 계통 조성하는 비용만큼 더 소요될 것이라 사료된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.435-438
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• 2004

This paper presents a new analytical model to suppress RLC resonance effects in power/ground lines due to a decoupling capacitor. First, the resonance frequency of an RLC circuit which is composed of package inductance. decoupling capacitor, and output drivers is accurately estimated. Next, using the estimated resonance frequency, a suitable decoupling capacitor sire is determined. Then, a novel design methodology to suppress the resonance effects is developed. Finally, its validity is shown by using $0.18 {\mu}m$ process-based-HSPICE simulation.

• 동위원소회보
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• 제21권4호
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• pp.46-54
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• 2006

Biocompatible and biodegradable hydrogels based on carboxymethyl cellulose(CMC) and polyethyleneglycol(PEG) were prepared far physical barriers for preventing surgical adhesions. These interpolymeric hydrogels were synthesized by a gamma irradiation crosslinking technique. The 1Scmxl.Scm of cecal serosa and adjacent abdominal wail were abraded with bane burr until tbe serosal surface was disrupted and hemorrhagic but not perforated. and the serosa of tbe cecum was sutured to the abdominal wall in 5mm apart from the injured sire. The denuded cecum was covered with either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. Control rat serosa was not covered. Two weeks later. the rats were sacrificed and adhesion was scored on a 0-5 scale. No treatment showed the significantly higher incidence of adhesions than either CMC/BEC hydrogels or solution from CMC/PEG hydrogel. In conclusion, these studies demonstrate that CMC/BEG hydrogels have a function of prevention of intra abdominal adhesion in a rat model.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.669-676
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• 2002

유전표지인자를 이용한 선발(marker assisted selection; MAS)과 전통적인 표현형기록에 근거한 반응의 비교분석을 위하여 고정효과모델(deterministic model)을 이용하여 시뮬레이션을 하였다. 자신의 단일 기록을 이용한 경우와 자신의 기록과 자신의 표지인자 정보를 이용할 경우 유전력이 높을수록 MAS의 효율성이 38%정도 높게 나타났다. 그러나 유전력이 높은 경우(50%) MAS의 효율성은 약 1%정도로서 효율성이 대단히 낮은 것으로 나타났다. 자신의 기록과 부모의 표현형 정보에 표지인자 정보를 추가할 경우 MAS의 효율성은 27% 정도였으며 마찬가지로 유전력이 높은 경우에는 효율성이 0에 가깝게 나타났다. MAS의 효율성은 유전력이 낮을수록 그리고 이용한 표지인자의 유전적 변이가 클수록 효율성이 높아지는 것으로 나타났다.