• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.436-437
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• 2006

Porcelain insulators have generally been used in Korea but polymer insulators which are superior in that they are light weight, explosion proof, impact proof, economical with construction characteristics, have been in use for the 154kV transmission line since 1999 following a worldwide trend towards the reduced weight, simplification and compact usage of new material insulators. However there have been approximately 500 cases of forest fires in Korea, so the transmission lines that for the most part pass through mountainous areas have been highly effected and the highly polymerized compound polymer insulator has raised concern about reliability in cases of exposure to forest fires. Therefore for the reliability assessment of the effect of forest fires on polymer insulators, mechanical and electrical characteristics are analyzed by an artificial flare test device and transmission facility surrounding conditions along with forest fire characteristics are surveyed. In addition to this, actual 90kV energized transmission line was tested with an artificial forest fire and the expanded usage of polymer insulators is presented through the analysis of mechanical and electrical characteristics and physical properties, and a study on the influence of forest fires on polymer insulators.

• 한국레이저가공학회지
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• 제4권2호
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• pp.21-28
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• 2001

The laser strengthening of 35kgf/㎟ and 60kgf/㎟ grade steel sheets is investigated by using CO$_2$ laser beam irradiation. The increase of tensile strength is dominated by the number of fully penetrated melting line. Also. the optimal laser input energy(hardness) and the number of melting line (melting width) are important variables for laser strengthening. Local strengthening by laser beam may be effective for the weight reduction of components where the tailored welded blank can not be applied.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1909-1915
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• 2008

The brake systems of the rolling stocks are generally consisted of electrical and mechanical brake systems. Because of its inherent structure of the each brake system, the electrical brake system is mainly used at the high speed range while the mechanical brake system is used at the relatively lower speed range. It is desirable for the rolling stocks to apply the entire electrical brake system. However, since the brake force from electric brake system is not enough to stop the rolling stock within the legal stop distance. Therefore, the mechanical brake system is indispensable to rolling stocks. In general, the vast majority of the world trains are equipped with mechanical braking systems which use compressed air as the force to push block on to wheels or pads on to discs. These mechanical systems are known as air brake or pneumatic brakes. For the air brake system, basically huge scale air compressor is equipped and the long pipe line is complexively connected. Since mass of these air brake components, it is difficult to be a light weight equipment and the long pipe line raise the maintenance problem. In order to overcome these problems of air brake system, the hydraulic brake system is proposed in this research. The hydraulic brake system makes the whole weight of brake equipment be light and large braking force can be applied. Therefore, in this research, the validity and advantages of applying the hydraulic brake system are reviewed.

• 소성∙가공
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• 제32권3호
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• pp.129-135
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• 2023

The use of engineering plastic products in internal combustion engine and electric cars to improve stiffness and reduce weight is increasing significantly. Among various lightweight materials, engineering plastics have significant advantages such as cost reduction, improved productivity, and weight reduction. In particular, engineering plastics containing glass fibers are used to enhance stiffness. However, the stiffness of glass fibers can increase or decrease depending on their orientation. Before developing plastic products, optimal designs are determined through injection molding and structural analysis to enhance product reliability. However, reliable analysis of products with variable stiffnesses caused by anisotropy cannot be achieved via the conventional isotropic structural analysis, which does not consider anisotropy. Therefore, based on the previously reported study "the Effect of Impacted Fracture in Glass Fiber Orientation with Injection Molding & Structural Coupled Analysis," this study aims to investigate the structural analysis and degradation mechanisms of various polymers. In particular, this study elucidates the actual mechanism of plastic fracture by analyzing various fracture conditions and their corresponding simulations. Furthermore, the objective of this study is to apply the injection molding and structural coupled analysis mechanism to develop engineering plastic products containing glass fibers. In addition, the study aims to apply and improve the plastic fracture mechanism in actual products by exploring anisotropy and stiffness reduction owing to the unfilled polymer weld line.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.21-27
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• 2003

Manifestation of heterotic genetic interaction was studied in different hybrids made between multivoltine recurrent backcross (RBL)/congenic lines (Con. L) during unfavourable season when temperature and relative humidity are > $30^{\circ}C$ and 86%, respectively. A few number of silkworm race or strain or breed like Nistari (N ＋ p or Np) can sustain the temperature above 3$0^{\circ}C$ and RH above 86%. The present heterosis study screened a hybrid i.e., CB$_{5}$Lm5RBL1M$_{6}$DPC-LmE$^1$RBL and its reciprocal provided heterobeltiotic effect on survival by number and pupation rate at a magnitude of 20% (p < 0.01) and yield by weight of 10% (p < 0.01). Beside all the hybrids expressed heterosis over check - Nistari (N ＋ p) with better quality silk. Therefore, aforesaid hybrid may be useful for utilization at commercial level during adverse seasons of West Bengal.gal.

• 한국의류학회지
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• 제11권1호
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• pp.29-42
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• 1987

This study was an attempt to survey, the relationships between women's values and preference in clothing design. For the measurement of values scale was to relect the theoretical, economic aesthetic, social. political and religious values explained by Allport-vernon- Lindzey. The preference rate in clothing design consisted of 50 items and 3 factors including color, form and texture. The questionnaire were administered to a sample of women (between college students and adult) who lined in Seoul, Korea. The date for 910 respondents were analyzed by person's carrelation coefficient, to-test and $x^2$ test. Through this study, the followings were founds; 1. Aesthetic value was the mast important of female college students values and economic value was the most important of adult's values. 2. There were significant relation between values and the preference for clothing form in line and style; 1) In line preference, adult women indicated negative correlation with religious values but positive correlation with aesthetic and political values. 2) In style preference, adult women indicated negative correlation with economic values positive correlation with social values, for female college students indicated positive correlation with aesthetic social and political values. 3. There were significant relation between values and preference for texture in touch, thickness, weight, light and luster; 1) In relationship between texture and values, adult women indicated touchness preference negative correlation with theoretical and religious values, for female college students indicated positive correlation with aesthetic and social values. 2) In thickness preference adult women indicated negative correlation with theoretical values but female college students indicated positive correlation with political values. 3) In weight preference, adult women indicated negative correlation with theoretical values. But female college students indicated positive correlation with religious values. 4) In brightness preference, only adult women indicated positive correlation with social values, negative correlation with economic values. In transparency preference, adult women indicated positive correlation with aesthetic values, negative correlation with religious values. 4. There were significant correlation among color and economic, aesthetic; political and religious values, that is, evacuation and economic political values in adult women there were positive correlation with religious values in female students. 1) In chroma only adult women indicated negative correlation with religious values. In warm and cold, positive correlation with economic values in both of them. 2) In coloration, adult women like a complement color indicated negative correlation with aesthetic values, but positive correlation with political values. 5. There were significant differences in the preference of clothing design between female college students and adult women; correlationship with color variables. Evacuation, both of them indicated negative correlation with chroma positive correlation with warm and cold and coloration. In chroma, adult women indicated negative correlation with coloration and warm and cold, for female students indicated negative correlation with coloration. 6. Comparison with clothing preference: 1) In color preference, adult women liked the most white, brown, blue and black in sequence. Female college students liked the most white, also the next is blue and pink. 2) Clothing design preference, there was significant difference in warm and cold and coloration, adult women more liked than female students. In shape of clothing, both of them indicated significant difference in line and style, female students more liked sporty style. In texture, adult women more liked soft thin light weight and bright. 3) In silhouette preference, the most is H-line, female college students more liked.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.423-426
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• 2009

POSTECH Graduate School of Wind Energy is trying to upgrade the PMSG used for Unison U50 to 900 kW class. Intensive optimization efforts are carried out the reduce the axial size and total weight of the generator while increasing the rated output to 900 kW. The generator features 3.32m stator inner radius, 671mm stator length, 84 pole, 25 rated rpm and 31.6kN/$m^2$ shear force density. To reduce the gross weight, the stronger magnetic material is applied with optimal magnet size resulting lowest cogging torque. Also, instead of stator skewing the stator, the magnet position along the circumference is optimized to further reduce the cogging torque. This scheme eliminates the stator skewing procedure and may enhance the productivity. This method also reduces the total harmonic distortion. In this report, upgrade method, no-load line to line voltage and phase voltage, cogging torque, loss calculations and thermal analysis are presented.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.23-30
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• 2002

The general and specific combining abilities and hybrid vigour of seven polyvoltine breeds [BL24, BL62, BL6S, BL67, BL68, BL69, and Pure Mysore (PM)] with five bivoltine breeds (NB4D2, CSR2, CSR5, CSR18 and CSR19) were evaluated in a line ${times}$ tester design by analysing six quantitative traits viz., fecundity, yield 110,000 larvae both by number and weight, cocoon weight, shell weight and cocoon shell ratio. ANOVA estimates showed significant effects for all the traits indicating the role of both additive and non- additive gene actions. Estimation of GCA revealed that the breed BL67 exhibited significant positive effects toy all the six traits followed by BL68 for four important economic traits viz., fecundity, cocoon weight, shell weight and cocoon shell ratio. Among testers, CSR5 showed significant GCA effects for five traits whereas CSR2 exhibited for shell weight and shell ratio. Three hybrids viz., BL67${times}$ NB4D2, BL67 ${times}$CSR5 and BL67${times}$ CSR19 excelled in four quantitative traits for SCA. Majority of the hybrids expressed positive hybrid vigour for cocoon yield/10,000 larvae by weight, cocoon weight and shell weight. Four hybrids namely PM ${times}$ NB4D2, BL67 ${times}$NB4D2, BL67${times}$ CSR5 and BL67${times}$ CSR19 manifesting positive hybrid vigour for five economic traits were adjudicated as best Heterotic hybrids and recommended for commercial exploitation to increase the silk yield.

• 한국작물학회지
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• 제38권6호
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• pp.537-544
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• 1993

화청벼 에서 유기된 초거대배 돌연변리계통을 육성하고 그의 미립 외형특성, 단백질함량 및 아미노산 조성, 지질함량 및 지방산 조성, 비타민 함량등의 영양특성 및 작물학적 특성을 원품종과 대비하여 조사하였다 그 결과는 다음과 같다. 1. 초거대배 변리계통의 현미 외형크기는 원품종과 차이가 없었으나, 1000립중은 원품종의 74.5%이었고, 1립당 배의 크기는 건물중으로 322%이었다. 2. 현미의 단백질함량은 8.99%로 화청벼의 7.39%에 비해 높았고, 저장단백질의 조성은 차이가 없었다. 아미노산조성에서는 현미 전체로 볼 때 lysine 함량이 월등히 증대되었고, methionine, serine, ,tyrosine 함량이 다소 감소되었다. 3. 현미의 지질함량은 5.7%로 원품종의 3.8%에 비해 1.5배 증가하였다. 지방산 중 팔미틴 산 함량은 증가하였고, 리놀산 함량은 감소하였다. 4. 배의 비타민 $B_1,B_2$, niacin함량에서 초거대배미와 원품종과는 차이가 없었으며, ${\alpha}$-tocopherol 함량은 감소하였으나, 현미 전체로 보면$B_1,B_2$, ${\alpha}$-tocopherol 함량이 월등히 증가하였다. 5. 초거대배미는 고영양미로서의 이용가치가 클것으로 판단되었다. 6. 초거대배 변이계통(M4)들의 정조수량은 원품종인 화청벼(556kg/10a)에 비해 69.2～78.8% 정도이었다. 생육형질의 변이계수로 보아 대부분 계통들이 고정된 것으로 나타났다.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.219-225
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• 2018

In this paper, for the testing of tensile strength of dead-end clamp used in transmission line, resulting values were estimated by designing and producing the horizontal version of widely-used vertical tensile tester. Tensile strength test of dead-end clamp for transmission line is essential for quality test of products. Moreover, tensile tester is an equipment that requires high level of reliability which needs to be examined through sampling tests commensurate with total inspection. Frames of tensile tester were made up of H-beams so that it can endure more than 20 [tons] of load capability and the test was implemented for 60[seconds] applying five types of tension. In consequence, the tester could withstand up to 21,600[kg] of weight as well as all types of tension. This newly developed horizontal tensile tester can be utilized in figuring out properties of various materials by estimating tensile strength of materials such as metal, rubber and fiber.