• Korean Journal of Poultry Science
• /
• v.15 no.3
• /
• pp.211-218
• /
• 1988

Data on egg number from time of first lay to 71 week of age were obtained from samples of single comb white leghorn breeder and brown layer breeder populations which were raised at manny breeding Co. These data were used to estimate the heritabilities of age at sexual maturity, early egg number, residual egg number and annual egg number. Also, the genetic correlation coefficients between these traits were estimated and selection efficiencies of each segment in early part record were estimated by use of the heritabilities and generic correlations. The estimated heritabilities and standard errors in two lines(W and B) were $0.30\pm0.07$ and $0.33\pm0.08$ at early records, $0.19\pm0.06$ and $0.18\pm$0.05 at residual records and $0.37\pm0.09$ and $0.49\pm0.10$ at time of first lay. Those at annual records were $0.24\pm0.06$ equally. The estimated correlation coefficients and standard errors between early record and annual record were $0.76\pm0.08$ and $0.77\pm0.07$. Those between early record and residual record were $0.46\pm0.15$ and $0.39\pm0.16$ respectively. At improving annual egg production per year, selection based on early part record(SM to 40 week of age) would be 69% more efficient than on annual record in line W and 80% more efficient than on annual record in line B. But, if it were considered that egg weight decreased due to sexual maturity and cost for data collection, use of selected segment from 35~40week of age in line W and from 31~40 week of age in line B would be desired in spite of a. small loss in relative selection efficiency. The generation interval would not be shortened.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.9
• /
• pp.775-782
• /
• 2016

In this study, elevated temperature design and integrity evaluation have been conducted using two different piping design codes for the high-temperature piping systems of sodium integral effect test loop for safety simulation and assessment(STELLA-2) being developed by KAERI(Korea Atomic Energy Research Institute). The design code of ASME B31.1 for power piping and French nuclear grade piping design guideline, RCC-MRx RD-3600 were applied, and conservatism of those codes was quantified based on the piping integrity evaluation results. The piping system of Model DHRS, Model IHTS and PSLS are to be installed in STELLA-2. The integrity evaluation results for the three piping systems according to the two design codes showed that integrity of the piping system was confirmed. As a code comparison result, ASME B31.1 was shown to be more conservative for sustained loads while RD-3600 was more conservative for thermal loads compared to B31.1.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.435-437
• /
• 2005

전력계통 운영은 시시각각 변화하는 전체 전력계통의 수요에 맞춰서 다양하고 광범위하게 구성된 발전 설비의 전력생산량을 정확히 일치시킴과 동시에 전국에 걸쳐 복잡하고 다단계적으로 망을 형성하고 있는 송전계통을 통하여 전력을 안정하게 유통하는 것이다. 이러한 수급조정과 계통의 안정운용이라는 기본적인 목표와 함께 수요의 급변이나 전력설비의 불시고장정지 등으로 전력 계통상황, 위급해지거나 정전사고를 유발할 경우 신속히 대응, 복수조치를 취할 수 있도록 능력을 확보하는 것 또한 주요 목표이므로 전력계통운영의 기본 목표를 효율적으로 달성하기 위한 기술발전의 목표와 현재의 당면한 기술적 과제를 효과적으로 대처해 나감으로서 중장기적으로 발전시켜 나아가야할 미래지향적 기술 발전 추진계획을 제시하였다.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.499-500
• /
• 2011

국내전력수요의 지속적인 성장과 더불어 전력산업의 대용량화, 고밀도화에 따른 친환경 고신뢰도의 전력계통 구성을 위하여 친환경 녹색기술의 초전도케이블이 실증시험을 통한 실계통 적용 사업이 이천변전소에서 정부지원으로 한전전력공사 주관으로 진행되고 있다. 그래서 향후 초전도 케이블이 실계통에 연계한 계통이 운용되는 것을 고려해야 하기 때문에 기존 전력기기와 협조하여 운영되기 위해서는 계통영향 분석이 필요하다. 특히 초전도케이블은 초전도성이라는 물리적인 특성 때문에 기존 계통해석과정과는 다른 계통 과도현상의 모델링이 필요하다. 따라서 본 논문에서는 초전도케이블의 실계통 적용을 위해서 이천변전소에 시범 적용된 22.9kV 50MVA 500m 초전도케이블 계통을 대상으로 열적특성을 분석하고 안정적인 대규모 전력전송을 위해서 초전도 케이블을 열적특성으로부터 보호하기 위한 열동계전기(Thermal Protection Relay)의 운영방법과 적용방안을 소개하고자 한다. 향후 대용량 초전도케이블의 실계통 적용 확대를 고려한 열동계전기의 운영방법과 적용방안도 제시하고자 한다.

• Current Research on Agriculture and Life Sciences
• /
• v.15
• /
• pp.17-24
• /
• 1997

According to the morphological characteristics of leaves, and flowers, including leaf and flower color, 24 horticultural cultivars of Calanthe discolor and C. striata which were collected from Jaeju island of Korea and cultivated at similar environmental conditions in Taegu from 1995 to 1996 were classified newly. Variation ranges were relatively narrow flower shape and leaf. but wide in other characteristics among cultivars.

• Pediatric Infection and Vaccine
• /
• v.22 no.3
• /
• pp.194-200
• /
• 2015

Purpose: Urinary tract infection (UTI) is a common bacterial infection in children and Escherichia coli is a predominant pathogen. The purpose of this study is to evaluate phylogenetic groups and virulence factors of E. coli causing UTI in children in Korea. Methods: From October 2010 to April 2013, urinary E. coli strains were isolated from the 33 pediatric patients of UTI. Multiplex polymerase chain reactions were performed to evaluate the phylogenetic groups and 5 virulence factor genes (fimH, sfa, papA, hylA, and cnf1) of E. coli. Distribution of molecular characteristics of E. coli was analyzed by clinical diagnosis and accompanying vesicoureteral reflux (VUR). Results: Most (84.8%) uropathogenic E. coli were belonged to phylogenetics group B2 and the others (15.2%) were belonged to group D. The virulence factors were distributed as: fimH (100%), sfa (100%), hylA (63.6%), cnfI (63.6%), and papA (36.4%). According to clinical diagnosis, phylogenetic distribution of E. coli strain was 92.3% of B2 and 7.7% of D in acute pyelonephritis and 57.1% of B2 and 42.9% of D in cystitis. Distribution of virulence factors was similar in both groups. In patients with acute pyelonephritis, phylogenetic distribution was similar in VUR and non-VUR group, but proportion of papA genes were lower in VUR group than that of non-VUR group (43.8% vs. 20.0%, P=0.399). Conclusions: This study provides current epidemiologic molecular data of E. coli causing pediatric UTI in Korea and will be a fundamental for understanding the pathogenesis of pediatric UTI.

• Korean Journal of Plant Resources
• /
• v.27 no.1
• /
• pp.51-59
• /
• 2014

In this study, we developed a high frequency watermelon regeneration system using three breeding lines ('B02', 'B05' and 'D04') of watermelon (Citrullus lanatus (thunb.) Matsum. & Nakai) which are differed in their fruits in shape, color of pericarp and flesh. The highest frequency of explants with callus was observed by using explants that consist of cotyledon proximal part end in all breeding lines, and the highest rate of callus induction was obtained on MS medium containing 1.0 mg/L BAP + 0.5 mg/L IAA for 'B02' (94%), 3.0 mg/L BAP for 'B05' (95%), 3.0 mg/L BAP + 0.1 mg/L IAA for 'D04' (90%). The highest shoot regeneration rates from derived callus were obtained on MS medium containing 1.0 mg/L BAP + 0.5 mg/L IAA for 'B05' (94%), and then a 'B02' (81%) with a same culture conditions, and the lowest regeneration was obtained on MS medium containing 1.0 mg/L BAP for 'D04' (56%). Regenerated plants showed the best rates of root formation on MS containing 0.1 mg/L IBA for 'B02' (67%), 0.1 mg/L NAA for 'B05' (87%), 0.5 mg/L IAA for 'D04' (88%). The regenerated plants showed a 100% survival rate in soil condition. The tissue culture and regeneration conditions obtained from this study will be useful for regenerating plants in breeding applications, and will be a useful tool for further genetic transformation studies on watermelons.

• Korean Journal of Environmental Biology
• /
• v.24 no.2 s.62
• /
• pp.112-118
• /
• 2006

We report mitochondrial cytochrome b (cyt b) genes from greenling Hexagrammos otakii (Jordan et Starks) and spotty belly greenling, H. agrammus (Temminck et Schlegel) within Hexagrammidae, two species of aquaculture importance. Of 489 bp of the cytochrome b gene, a little variation occurred between species (96% similarity). The pairwise distance (0.0342) between greenling and spotty belly greenling in term of the Neighbor-joining method indicated that two species was close in molecular phylogenetic consideration. These findings are applicable to aquaculture, fisheries genetics and molecular phylogenetics in the genus Hexagrammos.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.604-606
• /
• 2008

본 논문에서는 단상 계통 연계 태양광 인버터의 소신호 모델링을 통한 체계적인 제어기 설계 방법을 제안한다. 계통 연계 태양광 인버터의 내부 전류제어기는 계통 전압과 동상이 되도록 계통 주입 전류를 제어하고, 외부 전압제어기의 태양전지 안정화 제어기를 통해 태양전지의 최대전력점 추적제어를 수행한다. 태양전지의 전 동작 영역에서 안정적인 동작 수행과 계통주입 전류 제어를 위한 태양전지 전압 제어기 및 인버터 전류제어기의 안정도 해석 및 설계 방법을 소신호 모델링을 통해 제시한다. 본 연구에 제안된 방법은 200W급 태양전지를 이용한 축소 시스템을 이용하여 검증한다.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.588-589
• /
• 2007

전력계통은 송전선로, 발전기, 변압기 등의 다양한 요소들로 구성된다. 이러한 전력계통 내에서 스위칭 또는 낙뢰 등에 의해 과도현상이 발생할 경우, 고려해야 할 정도의 과전압이 발생하며, 이의 분석은 매우 중요하다. 본 논문에서는 전력계통 과도해석 프로그램인 EMTP-RV를 사용하여 발전기와 주변압기 연계 계통을 모델링하고, 계통 내에서 발생하는 과전압을 모의하였다. 또한 발생한 과전압이 제어회로에 미치는 영향을 모의하고, 분석하였다.