• 한국산학기술학회논문지
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• 제18권4호
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• pp.487-493
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• 2017

본 연구의 목적은 한국형포장설계법 프로그램을 이용하여 아스팔트포장에 발생하는 주요 파손 유형인 평탄성(IRI, International Roughness Index), 피로균열, 소성변형 등에 영향을 주는 요소를 평가하는 것이다. 평가에 사용된 설계입력변수로는 지역구분(서울과 부산), 교통량조건, 아스팔트 바인더, 표층용 골재의 최대치수, 아스팔트 표층 두께, 아스팔트 기층의 두께 등을 적용하였다. 해석조건은 위의 변수를 조합하여 총 64개의 case study를 수행하여, 이들 결과를 상호 비교 평가하여 아스팔트 포장의 파손에 영향을 주는 변수의 중요도를 평가하였다. 기본조건에서 1개의 변수에 의한 영향 고려시, 서울지역 5000대/일 교통량의 경우 아스팔트 바인더(C)의 영향이 다른 요소에 비해 상대적으로 크게 나타났고, 나머지 요소 중에서는 기층두께(A), 표층두께(B), 골재입도두께(D) 순으로 결과를 나타내었다. 10,000대/일 교통량의 경우도 마찬가지로 똑같은 결과 값이 나타났다. 부산지역 5000대/일 교통량의 경우 서울지역과 마찬가지로 아스팔트 바인더(C)의 영향이 다른 요소에 비해 상대적으로 크게 나타났고, 나머지 요소중에는 서울지역과 다르게 기층두께(A), 골재입도두께(D), 표층두께(B) 순으로 결과를 나타내었다. 교통량 조건과 지역에 따라 다소 차이는 있었지만, 아스팔트 포장 파손에 가장 큰 영향을 주는 요소는 아스팔트 바인더이고, 2가지 조합의 경우 아스팔트 바인더와 기층의 두께 등으로 평가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.183-188
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• 2012

To investigate the influence of the prolactin receptor 3 (PRLR3) gene and the retinol-binding protein 4 (RBP4) gene on the production traits of swine, genotyping was performed on 156 and 141 Berkshire pigs, respectively, that were carefully selected for economic traits. The frequencies of allele A in the PRLR3 locus and allele B in the RBP4 locus were 0.50 and 0.42, respectively. Neither locus was in the Hardy-Weinberg equilibrium. After a genotype was assigned to the individuals whose parents had the homozygous genotype, a statistical analysis was conducted for 291 pigs. The animals with the PRLR3 and RBP4 genotypes included 182 and 227 head, respectively. Even though the genotypic effects of PRLR3 (p<0.05) and RBP4 (p<0.01) had a significant influence on the pigs' back fat thickness, the interaction of both genes was not highly significant in terms of the back fat thickness (p = 0.1235). While the estimated epistasis effects of aaBB and aaBb decreased the back fat thickness and reduced the growth rate, the effects of AAbb and aabb increased the growth rate. Despite the insignificant difference in the PRLR genotypes in terms of the days to 90 kg and the average daily gain, the back fat thickness showed a significant difference (p<0.05), and the additive effect of allele A and the dominant effect of the hetero-genotype were -0.377 and 1.206 mm, respectively. The RBP4 genotypes had a very significant effect (p<0.01) on the back fat thickness, the days to 90 kg, and the average daily gain. The additive effects of allele B of the RBP4 locus on the back fat thickness, the days to 90 kg, and the average daily gain were 0.70 mm, -1.3 days and 6.2 g, respectively. Moreover, the dominant effects of the heterozygote for those traits were 0.63 mm, 9.9 days and -45.0 g, respectively. Allele A of the PRLR3 locus favorably influenced the back fat thickness, the days to 90 kg of the body weight, and the average daily gain and its dominant effect unfavorably influenced those traits. Allele B of RBP4 showed an incremental growth rate and back fat thickness, which could lower the lean meat percentage in the carcass. The RBP4 hetero-genotype negatively affected the pork production. These results strongly imply that the selection of allele A of PRLR3 and allele B of RBP4 would produce highly productive pigs in the Berkshire breed. Careful selection of allele B of RBP4 is required because of the increase in the back fat thickness.

• 소성∙가공
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• 제18권7호
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• pp.531-537
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• 2009

The effect of blank holding force on thickness variation in simultaneous sheet forming with rectangular shape and circular has been demonstrated. Because has investigated an effect on formability of magnesium sheet, in this paper, the effect of punch radius on formability have been thinning, various crack phenomena and forming velocity. By simultaneously forming process with circular and rectangular shape, the data of simultaneously forming process with circular and rectangular shape will used to a part development such as notebook computer case, cell phone and bipolar plate of fuel cell.

• International Journal of Aeronautical and Space Sciences
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• 제1권1호
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• pp.29-35
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• 2000

A numerical method to simulate Wing-In-Ground(WIG) effects for the wings moving near ground is developed. The aerodynamic analysis scheme for the wings is based on a compressible non-planar lifting surface panel method and the WIG effect is included by images. The thickness-induced effect is implemented into the lifting surface panel method by using the teardrop theory. The numerical simulation is done for the rectangular wings by varying the ground proximity. The present method is validated by comparing the calculated aerodynamic coefficients with other numerical results and measured data, showing good agreements.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.950-955
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• 2005

For the insulation design of a high temperature superconducting(HTS) cable, three kinds of design method were proposed, which used AC and impulse withstand voltage and partial discharge inception strength. However, the designed insulation thickness by AC and impulse could not be applied to cable fabrication process due to much low electrical breakdown strength. The effect of the multi-layered insulation paper was not considered on the previous insulation design and the insulation thickness by partial discharge inception strength could be applied only. In this paper, the electrical breakdown characteristic, which considered the effect of multi-layered of LPP, was investigated to design the insulation thickness.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권4호
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• pp.187-191
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• 2004

In this work, we used the PCID simulator for simulation of solar cell and examined the effect of front-back surface recombination velocity, minority carrier diffusion length, junction depth and emitter sheet-resistance. As the effect of base thickness, the efficiency decreased by the increase in series resistance with the increase of the thickness and found decrease in efficiency by decrease of the current as the effect of the recombination. Also, as the effect of base resistivity, the efficiency increased somewhat with the decrease in resistivity, but when the resistivity exceeded certain value, the efficiency decreased as a increase in the recombination ratio. The optimum efficiency was obtained at the resistivity 0.5 $\Omega$-cm, and thickness $100\mu\textrm{m}$. We have successfully achieved 10.8% and 13.7% efficiency large area($103mm{\times}103mm$) mono-crystalline silicon solar cells without and with PECVD silicon nitride antireflection coating.

• 대한기계학회논문집A
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• 제20권4호
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• pp.1356-1362
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• 1996

Fracture toughness of heterogeneous brittle materials such as poly crystalline ceramics used to present the size (thickness) effect as well as statistically distributed results. There is belief that both(size effect and scatter) must be associated with each other. However, no generally accepted theory has been established so far. Using statistical approach, a probabilistic modeling for the fracture toughness which describes the thickness effect was attempted in this paper, Weibull distribution of specific fracture energy(SFE)at local areas and Griffith criterion are applied to the model. In addition, the newly developed model was verified with experimental results of alumina.

• Structural Engineering and Mechanics
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• 제82권5호
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• pp.587-594
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• 2022

Behavior of concrete elements under the effect of high-speed projectiles has gain increasing interest recently. It's necessary to understand how far the concrete can absorb the effect of bullets in order to save the occupants when design security and military infrastructures. This study presents a total of 18 concrete slabs casted and tested under reinforcement ratios, 0%, 0.35% and 0.7%. Parameters interested were slab thickness, (50 mm, 100 mm, and 150 mm) and type of weapon. All specimens tested to investigate their response under the effect of attacking by two common types of weapon. In general, it was found that projectile penetration was controlled by their thickness regardless the steel reinforcement ratio. However, the steel reinforcement controls the damage.

• 한국의류학회지
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• 제23권4호
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• pp.551-562
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• 1999

This study was intended to investigate the effect on the human body such as subcutaneous fat thickness the circumference of extremities etc. of the clothing training of putting on thin clothes periodically from the cold period. The subjects were divided into the clothing training group and the non-training group, The training group was asked to wear cool clothes in daily life and to wear the training clothes of T-shirts with half-length sleeves and pants and perform the clothing training for two hours daily three times a week in a cold environment over the period from November to February. The non-training group was asked to lead a life wearing comfortable clothes. Then a comparative experiment was conducted at 15$\pm$1$^{\circ}C$, 50$\pm$5% R, H and 0.25m/sec before and after the clothing training. After the clothing training regardless of gender subcutaneous fat thickness was more increased and total clothing weight per the surface area of the body was decreased in the training group than the non-training group. The training group showed lower skin temperature in the limbs and lower average skin temperature than the non-training group irrespective of gender which proved the effect of the clothing training. The training group was shown to have attendancy toward a greater sense of warmth and a less sense of discomfort which proved the effect of the clothing training.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.827-836
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• 2004

The design parameter of the heat loss for the pressurized water reactor has been studied. The heat loss from the reactor vessel through the air gap. insulation are analysed by using the computational fluid dynamics code, FLUENT. Parametric study has been performed on the air gap width between the reactor vessel wall and the inner surface of the insulation, and on the insulation thickness. Also evaluated is the performance degradation due to the chimney effect due to gaps left between the panels during the installation of the insulation system. From the analysis results, the optimal with of air gap and insulation thickness and the value of heat loss are obtained The results show how the heat loss varies with the air gap width and insulation thickness. The temperature and the velocity distributions are also presented. From the results of the evaluation. the optimal air gap width and the optimal insulation thickness are obtained. As the difference between the predicted heat loss and measured heat loss from the reactor vessel is construed Primarily as losses due to chimney effect. the contribution of the chimney effect to the total heat loss is quantitatively indicated.