• 대한토목학회논문집
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• 제33권3호
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• pp.901-907
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• 2013

본 논문에서는 이방향 응력상태에서의 콘크리트 강도 특성과 크기효과 그리고 피로거동에 관한 연구를 수행하였다. 이를 위해 ASTM C 1550 시험법과 이방향 휨강도 시험(biaxial flexure test; BFT)을 적용하여 크기효과 및 피로시험을 실시하였으며, 단순보의 3등분점 하중에 의한 콘크리트 휨강도 시험(third-point bending test) 결과와 비교하였다. 실험 결과 3등분점 재하 휨강도 시험에 의한 일방향 응력상태의 강도보다는 ASTM C 1550 시험법과 이방향 휨강도 시험법에 의한 이방향 응력상태의 강도가 더 큰 것으로 측정되었다. 3등분점 재하 휨강도 시험, ASTM C 1550, 이방향 휨강도 시험법 모두 시편의 크기가 증가함에 따라 강도는 감소하는 것으로 관찰되었으며, 이방향 휨인장강도의 크기 효과가 일방향 휨인장강도의 크기효과보다 더 큰 것으로 확인되었다. S-N 곡선에 의한 일방향과 이방향 휨강도의 피로 수명은 유사한 것으로 분석되었다.

• 대한의생명과학회지
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• 제18권4호
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• pp.362-368
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• 2012

Enterotoxigenic Bacteroides fragilis (ETBF) is an intestinal commensal bacterium implicated as a risk factor for colon cancer. The key virulence factor is a secreted toxin called B. fragilis toxin (BFT). In this study we used an in vitro bioassay to examine the prevalence of ETBF in colonic washings from patients with colorectal polyps and normal control patients. We found that 9.3% of polyp patients and 10.9% of non-polyp patients harbored ETBF, respectively. A total of nine ETBF clinical isolates were isolated and confirmed to be positive for the BFT gene by PCR analysis and the ability to induce IL-8 secretion in the colonic epithelial cell line HT29/c1. Two of the ETBF clinical strains were characterized further in vitro and in vivo. We found that the two ETBF clinical isolates induced E-cadherin cleavage in HT29/c1 cells and promoted colonic inflammation in C57BL/6 mice. Our results indicate that the prevalence of ETBF in polyp patients were similar in non-polyp patients suggesting that ETBF carriage does not positively correlate to polyp incidence.

• 한국수산과학회지
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• 제52권5호
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• pp.482-495
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• 2019

This study compared the productivity of fish and vegetables grown using the hybrid biofloc technology-aquaponics (HBFT-AP), a semi-recirculating aquaculture system (SRAS), and hydroponics (HP). For the study of fish productivity (HBFT-AP vs. SRAS), fish were provided feed containing 3.0% monobasic potassium phosphate (MKP) for 18 weeks. After the 18-week feeding trial, the average weight of the sampled population (n=100) was not significantly different (P>0.05), while hematocrit (PCV, %), hemoglobin (Hb, g/dL), and plasma K (mEq/L) were significantly different (P<0.05) between the two groups (HBFT-AP: 47.83%, 15.48 g/dL, and 1.39 mEq/L; SRAS 34.83%, 11.81 g/dL, and 2.48 mEq/L). Leaf vegetable productivity (HBFT-AP vs. HP) was compared in three experiments (EXP 1-3), and slower growth was observed in both groups in EXP 2, in which pH was maintained at 5.0 or less throughout the experiment. During the 18-week feeding trial, total ammonia nitrogen (TAN), $NO_3-N$, and $PO_4-P$ levels increased with time in the HBFT-AP system, while the concentration of $NO_2-N$ remained below 0.1 mg/L throughout the study.

• 한국동물생명공학회지
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• 제38권1호
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• pp.32-37
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• 2023

This study has evaluated the genomic estimated breeding value (GEBV) of the commercial Hanwoo population using the genomic best linear unbiased prediction (GBLUP) method and genomic information. Furthermore, it analyzed the accuracy and realized accuracy of the GEBV. 1,740 heads of the Hanwoo population which were analyzed using a single nucleotide polymorphism (SNP) Chip has selected as the test population. For carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS), the mean GEBVs estimated using the GBLUP method were 3.819, 0.740, -0.248, and 0.041, respectively and the accuracy of each trait was 0.743, 0.728, 0.737, and 0.765, respectively. The accuracy of the breeding value was affected by heritability. The accuracy was estimated to be low in EMA with low heritability and high in MS with high heritability. Realized accuracy values of 0.522, 0.404, 0.444, and 0.539 for CWT, EMA, BFT, and MS, respectively, showing the same pattern as the accuracy value. The results of this study suggest that the breeding value of each individual can be estimated with higher accuracy by estimating the GEBV using the genomic information of 18,499 reference populations. If this method is used and applied to individual selection in a commercial Hanwoo population, more precise and economical individual selection is possible. In addition, continuous verification of the GBLUP model and establishment of a reference population suitable for commercial Hanwoo populations in Korea will enable a more accurate evaluation of individuals.

• 농업과학연구
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• 제48권4호
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• pp.655-668
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• 2021

The present study was conducted to investigate the effects of the supplementation of Achyranthes japonica extract (AJE) on overall performance levels with different nutrition concentrations in the diets of finishing pigs. Here, 140 finishing pigs with initial body weights of 50.18 ± 2.37 kg were used in a ten-week trial involving a 2 × 2 factorial design in two phases with the following factors: diet types with different nutrition concentrations (Positive control [PC] vs. Negative control [NC]) and 0 or 0.05% AJE supplementation to NC and PC diets. The PC diet was a basal diet, whereas the NC diet consisted of a 5% and 7% crude protein (CP) reduced basal diet during phase 1 (1 - 35 days) and phase 2 (36 - 70 days), respectively. A significant effect (p < 0.05) on the gain-to-feed ratio (G : F) was observed with interaction effects between the diets and AJE supplementation. However, during phase 1 and in all periods, the pigs fed the PC and NC diets with average daily feed intake (ADFI) tended to decrease compared to those fed diets with AJE. A significant effect (p = 0.0380) of E. coli was observed in pigs fed the PC and NC diets compared to AJE supplementation in phase 2 of the experiment. The backfat thickness (BFT) tended to decrease and the lean meat percentage (LMP) was significantly improved in phase 2 for pigs fed the PC and NC diets. In summary, BFT and LMP showed beneficial effects and fecal microbiota of E. coli counts were positively affected when pigs were fed diets with different nutrient concentrations.

• 농업과학연구
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• 제48권4호
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• pp.681-691
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• 2021

The estimated breeding value (EBV) and accuracy of Hanwoo steer (Korean cattle) is an indicator that can predict the slaughter time in the future and carcass performance outcomes. Recently, studies using pedigrees and genotypes are being actively conducted to improve the accuracy of the EBV. In this study, the pedigree and genotype of 46 steers obtained from livestock farm A in Gyeongnam were used for a pedigree best linear unbiased prediction (PBLUP) and a genomic best linear unbiased prediction (GBLUP) to estimate and analyze the breeding value and accuracy of the carcass weight (CWT), eye muscle area (EMA), back-fat thickness (BFT), and marbling score (MS). PBLUP estimated the EBV and accuracy by constructing a numeric relationship matrix (NRM) from the 46 steers and reference population I (545,483 heads) with the pedigree and phenotype. GBLUP estimated genomic EBV (GEBV) and accuracy by constructing a genomic relationship matrix (GRM) from the 46 steers and reference population II (16,972 heads) with the genotype and phenotype. As a result, in the order of CWT, EMA, BFT, and MS, the accuracy levels of PBLUP were 0.531, 0.519, 0.524 and 0.530, while the accuracy outcomes of GBLUP were 0.799, 0.779, 0.768, and 0.810. The accuracy estimated by GBLUP was 50.1 - 53.1% higher than that estimated by PBLUP. GEBV estimated with the genotype is expected to show higher accuracy than the EBV calculated using only the pedigree and is thus expected to be used as basic data for genomic selection in the future.

• 한국동물생명공학회지
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• 제38권4호
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• pp.268-274
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• 2023

Background: Recently, the single-step genomic best linear unbiased prediction (ssGBLUP) method, which incorporates not only genomic information but also phenotypic information of pedigree, is under study. In this study, we performed a ssGBLUP analysis on a commercial Hanwoo population using phenotypic, genotypic, and pedigree data. Methods: The test population comprised Hanwoo 1,740 heads raised in four regions of Korea, while the reference population used Hanwoo 18,499 heads raised across the country and two-generation pedigree data. Analysis was performed using genotype data generated by the Hanwoo 50 K SNP beadchip. Results: The mean Genome estimated breeding values (GEBVs) estimated using the ssGBLUP methods for carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS) were 7.348, 1.515, -0.355, and 0.040, respectively, while the accuracy of each trait was 0.749, 0.733, 0.769, and 0.768, respectively. When the correlation analysis between the GEBVs as a result of this study and the actual slaughter performance was confirmed, CWT, EMA, BFT, and MS were reported to be 0.519, 0.435, 0.444, and 0.543, respectively. Conclusions: Our results suggest that the ssGBLUP method enables a more accurate evaluation because it conducts a genetic evaluation of an individual using not only genotype information but also phenotypic information of the pedigree. Individual evaluation using the ssGBLUP method is considered effective for enhancing the genetic ability of farms and enabling accurate and rapid improvements. It is considered that if more pedigree information of reference population is collected for analysis, genetic ability can be evaluated more accurately.

• Journal of Animal Science and Technology
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• 제52권2호
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• pp.157-164
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• 2010

본 연구는 성숙한 한우 암소 도체에서 몇 개의 도체형질들이 경락단가나 도체가격과 같은 가격변수의 변이에 미치는 영향력을 파악하기 위하여 도체형질과 가격변수들 간의 상관관계 추정, 다중회귀분석 및 경로분석 등을 실시했다. 자료는 강원도 홍천지역 한우 사육농가에서 번식우로 사용되다 2008년도에 도축된 96두의 도체 판정결과를 이용하였다. 도축된 암소들의 도축시 평균 나이는 약 51개월 령이었으며, 도살시 생체중, 냉도체중, 등지방두께, 등심면적, 9단계로 구분하여 평가한 근내지방도 및 도체율의 평균치는 각각 556.81 kg, 319.24 kg, 10.95 mm, $78.08\;cm^2$, 3.92 및 57.19%였다. 그리고 도체경락단가와 도체가격은 각각 12,681원 및 4,070천원이었다. 경락단가와 상관계수가 큰 형질은 MAR, DP 및 EMA 등이었고 육량지수는 상관계수가 제일 작았다. 도체 경락단가를 종속변수로 CWT, BFT, EMA MAR 및 DP등 5개의 도체 형질을 독립변수로 적합시켜 추정한 다중회귀 방정식에서 모형 방정식의 결정계수는 69.86%였고, 도체가격을 종속변수로 하여 추정한 모형 방정식의 결정계수는 85.43%였다. 다중회귀 분석에서 CWT, BFT, EMA, MAR 및 DP의 표준화 편회귀계수는 AP를 종속변량으로 한 방정식에서 각각 -0.028, -0.106, 0.107, 0.814, 0.075, 그리고 CP를 종속변량으로 하는 방정식에서는 각각 0.561, -0.060, 0.083, 0.590, 및 0.051으로 나타나 AP의 변이에 큰 영향을 미치는 형질은 MAR 이었고, CP의 변이에 큰 영향을 미치는 형질은 CWT와 MAR이었던 것으로 판단된다. 경로분석 결과에서도 AP의 변이에 큰 영향을 미치는 형질은 MAR로서 직접효과와 간접효과를 합친 MAR의 기여도는 0.668이었다. 그리고 CP의 변이에 영향을 미치는 MAR의 기여도는 0.408 그리고 CWT의 기여도는 0.397이었다. 이상의 결과를 종합해보면 육량지수는 AP나 CP에 큰 영향을 미치지 않으며 AP의 변이에 영향을 크게 미치는 것은 MAR이고 CP에 영향을 크게 미치는 형질은 MAR과 CWT였다.

• 생명과학회지
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• 제27권3호
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• pp.295-300
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• 2017

제주재래흑돼지와 듀록의 교배 $F_2$ 집단에서 경제형질과 isocitrate dehydrogenase 3, beta subunit (IDH3B) 유전자의 유전자형의 연관을 시험하였다. IDH3B 유전자형은 promoter 영역에서 304-bp 삽입/결실 절편의 유무를 기준으로 기초축군과 $F_1$, $F_2$에서 판독하였다. 세 가지 유전자형(AA, AB, BB)이 $F_1$과 $F_2$에서는 모두 발견되었으나, JBP에서는 AA 유전자형이, Duroc에서는 BB 유전자형이 발견되지 않았다. 연관 분석결과에서 도체중(CW), 등지방두께(BFT)와 등심단면적(EMA)의 수준이 유전자형에 따라 유의적인 차이를 보였으나(p<0.05), 각기 다른 성장시기별로 측정된 체중들과 일당증체량을 포함한 성장형질, 유두수를 포함한 번식형질, 등심 내 조지방함량(CFAT)의 수준은 유의적인 차이가 없었다(p>0.05). IDH3B AA 동형접합자인 $F_2$ 돼지들은 다른유전자형을 보유한 개체들에 비해 도체중이 더 무겁고($72.92{\pm}11.133kg$), 등지방두께는 더 두껍고($25.75{\pm}6.06mm$), 등심단면적은 더 넓은 수준($23.82{\pm}4.825cm^2$)을 보였다(p<0.05). 이상은 비육돈 생산 후기에 근내지방의 축적과 상관없이, 등심단면적, 등지방두께, 도체중의 증가가 IDH3B 유전자형과 연관된 생물학적 작용에 의한 결과라 하겠다. 돼지 IDH3B의 304-bp 삽입 대립 유전자는 제주재래흑돼지와 Duroc-관련 분자육종체계에서 돈육 생산성 향상을 위한 분자도움선발의 유전적 마커로 이용될 것으로 기대된다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.614-617
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• 2008

This paper presents the numerical investigation of the characteristics of biaxial flexure specimens for the Biaxial Flexure Test(BFT) which was recently developed to measure the biaxial tensile strength of concrete. Using FEM, the effect of size and eccentricity on the specimens was evaluated. The parameters such as radious of the support and the loadings, thickness and free length were studied. The results of the FE analysis were entirely consistent with the predictive solution, when b/agt;0.4, h/alt;0.6 and the thickness of the specimens were increased. On the other hands, when b/agt;0.4, those with lesser free length showed good results. To limit the difference between the stresses at the end points of 2b as the specimen was sustained and the stress at the center point of the specimen are not over 10%, lateral eccentricity was analyzed to be in the limits of 3%.