• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.291-298
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• 2008

For many years beak trimming has been a controversial subject, particularly since the 1980's when the practice came under close scrutiny by animal welfare groups. In Australia it is considered an essential practice, averting losses of AUD$17.5m annually by reducing mortality from cannibalism. While mortality in flocks from cannibalism can be reduced from 25% of the flock to virtually nil, the beak trimming procedure is considered traumatic for the bird. This study examined if chronic pain in the beak was evident in birds 10, 20 and 60 weeks after being trimmed at hatch and in another group of birds, 8 and 52 weeks after being re-trimmed at 14 weeks. Chronic pain was assessed by measuring pecking behaviour and beak sensitivity responses. Pecking behaviour studies completed after beak trimming and re-trimming showed no evidence to indicate that birds were suffering severe chronic pain in the beak. Beak trimmed pullets pecked more at the cage and had more toe pecks, yet overall pecks made at the feed and the environment were no different than untrimmed controls. While the beak sensitivity studies provided evidence that the beak of birds trimmed at hatch and also re-trimmed at 14 weeks may be more sensitive there was no evidence that re-trimming resulted in a more sensitive beak than birds trimmed at hatch only. These studies have shown that birds which are beak trimmed and re-trimmed return to apparently normal feeding and pecking behaviour in the long term. However, there was limited evidence that beaks of trimmed birds have an altered threshold to potentially painful stimuli.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.61-61
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• 2010

The purpose of this study is to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in the ultra large containership during service life. In order to do it, the behavior of the embedded crack at the weldment under design loading conditions was evaluated in accordance with BS7910. Here, the level of primary stress induced by ship motion was evaluated by the design code of classification society and FEA. The level of residual stress as secondary stress was calculated in consideration of the restraint degree of weldment and welding heat input by using the predictive equation proposed by authors in the previous study. The fatigue crack growth rate at the weldment was evaluated using CT specimen in accordance with ASTM E647. According to the results, although the allowable defect for embedded crack specified in the classification society exists at the weldment, the occurrence possibility of unstable fracture at the weldment could not be negligible, regardless of CTOD value given in this study. So, in this study, the effect of initial defect size, welding heat input, restraint degree and CTOD on the fracture mechanical characteristics of embedded crack at the weldment was evaluated by the comprehensive fracture assessment. Based on the results, the design criteria including allowable defect, residual stress level and CTOD value was established to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in an ultra large containership during service life of 20years.

• 농업과학연구
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• 제47권2호
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• pp.255-262
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• 2020

The aim of this study was to investigate the growth performance between two different crossbred strains of Korean native chickens denoted as 1E and 2E with a white semibroiler (LL) from hatch to d-84 post-hatch. A total of 450 one-day-old chicks were randomly distributed into cages which included 15 replicate cages each for 1E and 2E with 9 replicate cages for LL. A three phase feeding program was used as a starter (Day 1 - 35; crude protein [CP] 20.3%; metabolizable energy [ME] 3,059 kcal·kg^-1), grower (Day 36 - 56; CP 18.6%; ME 3,123 kcal·kg^-1) and finisher (Day 57 - 84; CP 16.7%; ME 3,187 kcal·kg^-1). The results revealed that LL had a higher (p < 0.05) BW during d-8 to d-84 compared with the other two cross breed groups. A higher (p < 0.05) ADG was observed from the LL during the entire period except from d-1 to d-14 and d-71 to d-84 when compared with 1E and 2E. Shank length did not vary (p > 0.05) between the strains, despite LL having a SL that was 2.86% higher (p < 0.05) when compared with the other strains from d-15 to d-21 post-hatch, and 1E had a SL that was 2.28% (p < 0.05) higher when compared with the other strains during the first week of the experiment.

• 한국가금학회지
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• 제46권1호
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• pp.1-10
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• 2019

닭의 성장과정에서 어린 병아리의 발달에 가장 결정적인 시간으로 인식되는 시점은 부화 전 수일부터 부화 후 수일간이다. 부화 전후의 충분한 영양소 공급은 배아의 최종 발달과 병아리의 초기성장에 결정적 기여를 한다고 볼 수 있다. In ovo feeding에 의한 탄수화물 또는 아미노산의 공급은 부화 전 후의 소화장기 발달에 긍정적으로 작용한다. Prebiotics과 synbiotics 등에 대한 in ovo 주입은 건강한 미생물 균총 형성 등을 제공하여 영양적, 면역적 측면에서 좋은 결과들을 볼 수 있지만, 연구 결과의 수적 제한과 in ovo 주입의 양과 주입 부위 및 주입시기 등에 대한 추가적인 연구가 요구된다. 탄수화물을 이용한 in ovo feeding은 부화시 체중 증가를 보이지만 육계의 부화 후 능력에는 크게 영향을 보이지 않으며, 탄수화물 주입에 따른 부화율 감소는 기술적 요인(최적 농도, 주입 장소, 부피 등)이 크게 작용하는 것으로 보인다. In ovo feeding에 의한 아미노산 공급은 병아리의 세포성 면역과 체액성 면역을 높여 초기 면역 향상에 도움이 되는 것으로 판단된다. In ovo feeding은 부화 전후의 최적의 영양소 공급과 면역력 증진 및 절식에 따른 병아리의 스트레스를 완화시켜주는 실용적인 기술이 될 수 있다.

• Journal of Ship and Ocean Technology
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• 제3권4호
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• pp.35-51
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• 1999

Fatigue strength assessment procedures have been implemented in the ship design rules by many classification societies. However, a large variation tin the details of the different approaches exists in practically all aspects influding load history assessment, stress evaluation and fatigue strength assessment. In order to assess the influences of thesd variations on the prediction of fatigue lives. a comparative study is organized by the ISSC Committee III.2 Fatigue and Fracture. A pad detail on the top of longitudinal hatch coaming of a panamax container vessel is selected for fatigue calculation. The work described in this paper is one set of results of this comparative study in which the ABS dynamics approach is applied. Through this analysis the following conclusions can be drawn. (1) With the original ABS approach, the fatigue life of this pad detail is very low, only 2.398 years. (2) The treatment of the stillwater bending moment in the ABS approach might be a source of conservatism. If the influence of stillwater bending moment is ignored, then the fatigue life for this pad detail is 7.036 years. (3) The difference between the nominal stress approach and the hot spot stress approach for this pad detail is about 26%.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.50-55
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• 2007

Stereolithography (SLA) is a technique using a laser beam to cure a photopolymer liquid resin with three-dimensional computer-aided design (CAD) data, The accuracy of the prototype, the build time, and the cured properties of the resins are controlled by the SLA process parameters such as the size of the laser beam, scan velocity, hatch spacing, and layer thickness, In particular, the size of the laser beam is the most important parameter in SLA, This study investigated the curing properties of photopolymers as a function of the laser beam size, The cure width and depth were measured either on a single cure line or at a single cure layer for various hatch spacings and laser beam sizes, The cure depth ranged from 0.23 to 0.34 mm and was directly proportional to the beam radius, whereas the cure width ranged from 0.42 to 1.07 mm and was inversely proportional to the beam radius, The resulting surface roughness ranged from 1.12 to $2.23{\mu}m$ for a ratio of hatch spacing to beam radius in the range 0.5-2.0 at a beam radius of 0.17 mm and a scan velocity of 125 mm/sec.

• 대한조선학회지
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• 제24권3호
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• pp.25-34
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• 1987

Whereas the finite element method is well established today, the boundary element method is a fairly recent development. Both are general-purpose methods for the solution of various structural analysis problem. The B.E.M has several potential advantages relative to the F.E.M. One of them is that the number of unknowns in algebraic system obtained by discretization is proportional to the number of boundary nodes. Anothor advantage is the ease of discretization and input data preparation. However, the B.E.M. always leads to a fully populated and unsymmetric system of equations. Even though the number of degree-of-freedom is reduced as compared with F.E.M, since nodes exist on the boundary only in the B.E.M, to follow that the effort to solve the equations can be greater. It has been shown also that the time spent in setting up the coefficient matrix is a significant and can, in some cases, be greater than the time required to solve the equation. Thus, one can naturally consider the idea that two methods should be coupled, then the advantages of both methods can be taken. And further, by using this coupling method the HATCH CORNER was analyzed to give initial design data.

• 한국정밀공학회지
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• 제20권2호
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• pp.76-84
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• 2003

Stereolithography is the technique using a laser beam to cure a liquid resin, a photopolymer, with three dimensional computer-aided design (CAD) data. The build parameters of stereolithography such as beam size, scan velocity. hatch spacing, layer thickness and etc. are determined by the accuracy of prototype, the build time and the cured properties of the resin. In particular, beam size is important processing parameter fur the other parameters. Therefore, this study observed the cured property to beam size. For this purpose, according to hatch spacing and beam size, the cure width and depth were measured on single cured line. Also, the cure width and depth were measured at single cured layer As a result of experiments. cure depth which varied from 0.23mm to 0.34mm was directly proportioned to beam radius. on the other hand, cure width which varied from 0.42mm to 1.07mm was inversely proportioned to beam radius. Surface roughness varied from 1.12 to 2.23 m for the ratio of hatch spacing to beam radius.

• 한국응용곤충학회지
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• 제35권2호
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• pp.119-125
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• 1996

가루깍지벌레 월동안 부화시기 예찰모형을 수립하기 위하여 월동알에 대한 온도발육 실험이 수행된다. 5개온도(10, 15, 20, 25, 27$^{\circ}C$)와 채집시기별로 월동알 부화기간을조사하여 비교분석하였다. Wagner 등 (1984a)의 비선형발육모형이 온도별 평균발육률에 대하여 적용되었으며 ($R^2$=0.9729). 발육영점온도는 15~$25^{\circ}C$ 영역에서 얻은 직선회귀식에 의하여 $11.9^{\circ}C$로 추정되었으며, 발육완료를 위해서는 154.14일도가 필요하였다. 적산온도 모형과 발육률전산(Wagner 등 1985) 모형이 부화시기 예측에 이용된다. 적산온도 모형은 평균온도에서 발육영점온도 이상의 온도를 적산하는 방법(Mean-minus-base 추정법), Sine wave 추정법(Allen 1976), 그리고 Rectangle 추정법(Arnold 1960)을 잉요하여 계산하였다. 50% 부화예측일을 실측일과 비교한 결과 적산온도를 이용하는 경우 Mean-minus-base 추정법은 18~28일, Sine wave 추정법은 11~14일, 그리고 Rectangle 추정법은 3~5일의 편차를 보였고, 발육률 적산모형은 2~3일의 편차가 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.834-841
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• 2019

Objective: This study was conducted to investigate the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the energy metabolism in thigh muscle of embryos and neonatal broilers. Methods: A total of 960 eggs were randomly assigned to three treatments: i) non-injected control group, ii) saline group injected with 0.6 mL of physiological saline (0.75%), and iii) CrPyr group injected with 0.6 mL of physiologi-cal saline (0.75%) containing 12 mg CrPyr/egg on 17.5 d of incubation. After hatching, 120 male chicks (close to the average body weight of the pooled group) in each group were randomly assigned to eight replications. The feeding experiment lasted 7 days. Results: The results showed that IOF of CrPyr increased glucose concentrations in the thigh muscle of broilers on 2 d after injection (p<0.05). Compared with the control and saline groups, the concentration of creatine in CrPyr group was increased on 2 d after injection and the day of hatch (p<0.05). Moreover, IOF of CrPyr increased the creatine kinase activity at hatch and increased the activities of hexokinase and pyruvate kinase on 2 d after injection and the day of hatch (p<0.05). Chicks in CrPyr group showed higher mRNA expressions of glucose transporter 3 (GLUT3) and GLUT8 on the day of hatch (p<0.05). Conclusion: These results demonstrated that IOF of CrPyr was beneficial to enhance muscle energy reserves of em-bryos and hatchlings.