• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.2
• /
• pp.83-91
• /
• 2022

Seismic design and analysis of nuclear power plant components are performed based on an decoupled model. However, this decoupled analysis has a limitation in that it generates inaccurate results compared to the coupled analysis because it cannot simulate actual phenomena such as the interaction between structures and components. Thus, this study performed seismic coupled and decoupled analysis on an existing nuclear containment structure and related components, considering the mass and natural frequency ratios. And based on these results, comparative analyses of responses of components were conducted. Consequently, the seismic coupled analysis result generally gave a smaller value than the decoupled analysis result. These results were similar to the analysis results for the simple coupled model, which was an existing study, but the difference in component responses was much more pronounced. Also, this was influenced by the installation location of the component rather than the influence of the input frequency of the input seismic motions. Finally, the difference between the decoupled and coupled seismic analysis occurred in the region where the mass ratio of the components was large, and the natural frequencies were almost similar due to the considerable dynamic interaction between the structure and the component in this realm.

• Korean Journal of Poultry Science
• /
• v.7 no.1
• /
• pp.31-42
• /
• 1980

In order to identify the best superior cross combination of breeder stocks for broiler production, combining ability test and analyses of phenotypic performances for parent stocks were examined on records of 1,440 broiler chicken which were produced from 4 parental strains and 3 maternal strains at Hanhyup Poultry Breeding Farm from September 28, 1978 to January 5, 1979. The results obtained were as follows; 1. There was not found heterosis effect in viability but it seems to be desirable to select Hubbard strain in paternal line to improve viability. 2. As the paternal and maternal lines, selection of Ross strain showed the best paternal and maternal performance and the best general combining ability in body weight at 8 weeks of age is expected to be able to improve body weight of it s crossbred And the most superior cross combinations based on the specific combining ability and performance of rack crossbred were identified as Hubbard x Ross ana Ross x Hypeco crossbreds. 3. The best paternal and maternal lines on the smallest feed consumption for 8 weeks were Hubbard and Ross strains, and Hypeco strain, respectively. Especially Hubbard x Hypeco cross combination was proved as the smallest feed consumption compared with other cross combinations. 4. In feed requirement per Kg body weight increase, Hubbard strain for paternal line, Hypeco strain for naternal line, and cross combinations of Hubbard x Hypeco, Hubbard x Ross and Ross x Hypeco were certified as the most superiors. 5. Also superior cross combinations of Hubbard x Hypeco and Hubbard x Ross earned the most profit per bird through economic analysis. According to results as shown above, this experiment seems to be able to reach a such conclusion that production of superior cross combinations Hubbard x Ross, Hubbard x Hypeco and Ross x Hypeco through selection of Ross and Hubbard strains to paternal line and Hypeco and Ross strains for maternal line may become to considerable improvement for important economic characters of broiler; viability, body weight, feed consumption and feed requirement.

• Korean Journal of Poultry Science
• /
• v.11 no.2
• /
• pp.86-92
• /
• 1984

Present study was carried out to estimate phenotypic and genetic parameters influencing body weight (BW) at 4 weeks of age egg breadth (EB), egg length(EL), egg shape index (SI) and egg weight (EW) at 32 weeks of age and egg numbers (EN) up to 38 weeks of age in broiler male and female lines. The data were collected from closed White Plymouth Rock (female line; G) and Cornish (male line; C) flocks involving 1193 pullets from 211 dams and 48 sires in 1982. The results obtained are summarized as follow: 1. General performance for various trails of lines C and G. The means and standard deviations of BW, EB, EL, SI, EW and EN were 668.34${\pm}$47.18, 4.23${\pm}$0,11, 5.49 ${\pm}$0.19, 77.06${\pm}$2.98, 55.73${\pm}$3.54 and 59.72${\pm}$13.39 in line C, respectively and 487.89${\pm}$ 41.43, 4.22${\pm}$0.11, 5.51${\pm}$0.19, 76.72${\pm}$3.20, 55.43${\pm}$3.26 and 76.93${\pm}$12.17 in line G, respectively. 2. Heritability Heritabilities were estimated from sire, dam and combined components. Estimates for BW, EB, EL, SI, EW and EN from combined components were 0.30, 0.29, 0,40, 0.22, 0.45 and 0.60 in line C, respectively and 0.33, 0.23, 0.28, 0.13, 0.49 and. 0.33 in line G, respectively. 3. Correlation Genetic and phenotypic correlations showed similar trend in line C and G. Genetic correlations, estimated EW with EB and EL, were high and positive (line C; 0.99, 0.75, respectively and line G; 0.94, 0.82, respectively), also correlation of EB with EL was 0.58 (both lines; 0.58). High and negative genetic correlations were shown between SI and EL in line C and G (-0.70, -0.65, respectively). Genetic correlations between SI and EW were relatively low and negative in line C and G (-0.11, -0.19, respectively) and between SI and EN were relatively low and positive in line C and G (0.25, 0.17, respectively). Between other traits, low genetic correlations were shown in both lines, High and positive correlation was estimated between hatchability and egg shape index and polynomial regression of egg shape index on hatchability was estimated; Y=-216.77＋7.6216X-0.0146939X$^2$.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.2
• /
• pp.87-93
• /
• 2020

Seismic responses due to the dynamic coupling between a primary structure and secondary system connected to a structure are analyzed in this study. The seismic responses are compared based on dynamic coupling criteria and according to the error level in the natural frequency, with the recent criteria being reliant on the error level in the spectral displacement response. The acceleration responses and relative displacement responses of a primary structure and a secondary system for a coupled model and two different decoupled models of two degrees-of-freedom system are calculated by means of the time integration method. Errors in seismic responses of the uncoupled models are reduced with the recent criteria. As the natural frequency of the secondary system increases, error in the natural frequency decreases, but seismic responses of uncoupled models can be underestimated compared to that of coupled model. Results in this paper can help determine dynamic coupling and predict uncoupled models' response conservatism.

• Korean Journal of Poultry Science
• /
• v.19 no.3
• /
• pp.113-123
• /
• 1992

This study was carried out to build up new synthetic egg Production lines which had sex linked gene for feather color sexing and had also superior combining ability for producing the best commercial chicks. In order to make autosexing layer line, the commercial layers which had Z$^{s}$ Z$^{s}$ and Z$^{s}$ W were mated. Among progeny, the chicks which had homozygote of silver gene and non-silver gene were selected for making dam and sire lines. Afterwards the closed flock breeding method was utilized to improve general performances of the each line. The performances of egg production in synthetic line were 161 day for age at sexual maturity, 219 eggs for total egg number to 60 weeks of age, 84% for hen-day egg production and 619 for average egg weight. There was no difference in egg production between new synthetic lines and imported breeds. In the analysis of genetic trends, the estimates of genetic parameter in the autosexing lines were similar to those of the general population of layer breeders. This results indicated the consistency of genetic variation from this selection.

• KOREAN POULTRY JOURNAL
• /
• v.41 no.9
• /
• pp.102-105
• /
• 2009

농촌진흥청 국립축산과학원(원장 라승용)은 지난 15년간의 재래닭 수집과 순계 복원, 연구 및 개량을 통해 '우리맛닭'을 탄생시켰다. 재래닭 복원 프로젝트는 1994년부터 1997년까지 4년간 대한양계협회에서 '재래닭육용화 사업'의 일환으로 서울대학교 오봉국 박사(본회 고문)의 진두지휘 하에 대학교 수 16명, 연구관 8명 등 연인원 84명과 9억2천만원의 예산이 투입되어 진행됐으며, 11개의 과제를 수행해 마침내 재래닭 순계 복원에 성공하였다. 연구진은 이후 연구 결과물을 축산과학원으로 이관하여 후속연구를 지속토록 하였으며, 축산과학원은 이로부터 우수한 실용계를 생산하는 연구에 착수하게 됐다. 이러한 과정을 거쳐, 경제적으로 불리한 기존 재래닭의 문제점을 보완하여 산란성과 산육성이 우수한 닭으로 개발한 것이 바로 '우리맛닭'이다. '우리맛닭'은 축산과학원이 보유한 9개 순계 모군으로부터 성장이 빠른 부계통과 맛이 좋고 알 생산이 많은 모계통의 교잡을 통해 맛이 좋고 성장이 빠른 실용계로 생산된다. '우리맛닭'은 콜라겐 함량이 높아 탄력감과 쫄깃한 느낌의 육질을 지니고 있으며, 이를 접하는 소비자들의 반응도 좋게 나타나 그 가능성이 긍정적으로 점쳐지고 있다.

• Korean Journal of Poultry Science
• /
• v.8 no.1
• /
• pp.1-5
• /
• 1981

In trying to predict the effect of genetics on the broiler in the year 2000, this is a relatively short period of time as far as broiler genetics in concerned. Modern broiler genetics started around 1945 and tremendous gains when made in past 35 years. Futher improvements on broiler will depend on the evolution and revolution: 1. Evolution: (1) Growth rate has been made 4-5% per year. (2) Feed conversion has improved approximately 1% per year. (3) Abdominal fat is becoming a major complaint in broiler. (4) Because of the changing life-style, broiler meat sales in the future will be more and more in cut-up form. (5) Breeding for stress resistance and selection for docile temperament can be important in order to funker improve fled efficiency. (6) In female parent stock, reproduction characteristics are in many can negatively correlated with the desired broiler traits. (7) Egg production and hatchability in moot commercial parent nod m at a fairly high level. (8) In male parent stock, the heavier and mon super-meat-type male lines are desired to Product better broilers. 2. Revolution: Trying to forecast revolutionary change in broiler genetics is highly speculative, as sudden change are aften unpredictable. (1) Species hybridization, such as a turkey-chicken cross (2) Biochemical tools, such as blood typing. (3) Mutation breeding by radiation or chemical mutagentia. (4) Broiler breeding would be to change the phenotypic appearance by single gene, such as naked, wingless. (5) Changes in production techniques. such as growing in cage or growing in filtered air positive pressure houses.

• Korean Journal of Poultry Science
• /
• v.44 no.2
• /
• pp.123-134
• /
• 2017

This study was conducted to establish new synthetic lines of Korean Native Chicken. We performed $5{\times}5$ diallel crossings with GPS lines of Korean Native Chicken for the selection of parent stock. The production traits including viability, body weight, age at first egg laying, egg weight, hen-day egg production, and hen-housed egg production were measured and analyzed for 25 crosses with 1,157 hens. The heterosis effects of these traits were also estimated. The results showed that the average survival rate during laying periods was 67.7% in the pure lines and 77.1% in the crosses. The 25 cross combinations were shown to be distinctly divided into three groups according to body weight; nine crosses in the high-weight group, 12 crosses in the medium-weight group and four crosses in the light-weight group. The average body weight at 12 weeks of age was $1,873.8{\pm}43.0g$ in the high group, $1,595.4{\pm}56.6g$ in the medium group and $1,152.7{\pm}24.7g$ in the light group, and $1,560.2{\pm}339.3g$ in the pure lines and $1,640.9{\pm}213.7g$ in the crosses. In terms of egg production performance, the age at first egg laying was $139.7{\pm}4.9$ days in the pure lines and $135.8{\pm}5.1$ days in the crosses. The average egg weight was $52.3{\pm}1.6g$ in the pure line and $53.0{\pm}1.6g$ in the crosses. The average hen-housed egg production from 20 to 40 weeks was $58.3{\pm}12.9$ eggs in the pure line and $69.2{\pm}10.4$ eggs in the crosses. The average heterosis effect was 16.9% for survival rate, 5.4% for body weight at 12 weeks, -2.7% for age at first egg laying, 1.3% for egg weight, and 14.3% for hen-day egg production. Generally, the heterosis effect for viability and egg production traits was higher than that for growth trait. On the basis of these results, it is expected that the selection of the HF combination, which had excellent growth performance, is the most desirable as the paternal strain, and the selection of GW and FW combinations, which had excellent laying performance, are preferable as the maternal strain.

• Korean Journal of Poultry Science
• /
• v.48 no.1
• /
• pp.41-50
• /
• 2021

Although feather-sexing using sex-linked genes related to feather development is a widely used chick sexing method in the poultry industry, the feather-sexing method has yet to be used for Korean native chickens (KNCs). The purpose of this study was to construct a KNC feather-sexing line using early-feathering (EF) and late-feathering (LF) genes for industrial application. Using 557 reddish-brown KNCs as the basal flock, frequencies of the EF (k) and LF (K) genes were estimated to be 0.814 and 0.186, respectively. This indicating that it would be feasible to construct a feather-sexing line using this chicken group, and we accordingly constructed EF paternal and LF maternal lines. On the basis of test-cross for the selection of LF homozygous (KK) males in the maternal line, we confirmed that three of 40 chickens were homozygous males. The survival rate, body weight, days at first egg-laying, hen-day egg production, and egg weight were analyzed to compare the production performance of EF and LF chickens. The results revealed that EF chickens were characterized by a superior survival rate, whereas LF chickens were superior in terms of egg production rate. However, no differences between LF and EF chickens were detected with respect to other production performance parameters. In addition, assessment of the fitness of sexed chicks produced in the established KNC feather-sexing lines revealed that the accuracy of sexing was 98.6%. Collectively, these findings indicate the feasibility of constructing effective KNC feather-sexing lines with potential industrial application.

• Korean Journal of Poultry Science
• /
• v.43 no.4
• /
• pp.207-212
• /
• 2016

This work was carried out to investigate the ability of thirteen crossbreds for production of commercial chicken (CC) of Korean native chicken to be cut out for Korean circumstance. Total of one thousand three hundred of crossbreds were divided thirteen groups (100 birds/group) that were twelve groups (1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6A, 6B) to crossbreed with two sires (A, B) and six dams (1, 2, 3, 4, 5, 6) of parent stock (PS) of Korean native chicken and one group (HH) as commercial Korean native chicken. Experimental diets were starter diet (0~7d; CP 22.0% ME 3,150 kcal/kg), early diet (8d~Wt 800 g; CP 19.0% ME 3,150 kcal/kg) and finished diet (Wt 800 g~12 wk; CP 18.0% ME 3,150 kcal/kg). Fertility of 1B group was higher than other groups. Hatchability per fertilization eggs and hatchability per setting eggs were 87.5~89% and 87.9~96.3%, respectively, and those of 4B and 6B groups were lower compared to other groups. Weekly body weight of HH group was lower than other groups. CV values of body weight of thirteen groups were showed over 12% as 12.5~18.2%, and especially, those of 2B, 3B, 5B, HH groups were lower compared to other groups. Weekly feed conversion ratios (FCRs) of 13 crossbreds were 1.7~2.3, 2.1~2.5, 2.4~2.7 and 2.7~3.2 at the age of 6, 8, 10 and 12 weeks, respectively. Weekly production indexes of 2A, 3A and HH groups were the lower than other groups and those of thirteen groups decreased following weeks. Feed costs per body weight gain (kg) were 1,069~1,255 won, 1,100~1,263 won, and 1.468~1,696 won at starter, earlier and finished period of broilers. These results leaded down to conclusion to be possible selection of new Korean native commercial chicken that have the excellent performance and economics.