• Title/Summary/Keyword: 레이스면

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Influence of Contact Types on the Stress Distributions in Large-Diameter Rolling Bearings (대형 구름 베어링의 접촉형태가 응력분포에 미치는 영향에 관한 연구)

  • 이승렬;이영제;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1995.06a
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    • pp.54-64
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    • 1995
  • 대표적인 대형 베어링인 일체형 볼 베어링과 와기어 레이스형 볼 또는 로울러 베어링의 마찰 특성을 비성형 유한요소 프로그램인 MARC를 사용하여 상호간의 마찰형상에 대한 접촉응력과 마찰력 특성을 비교 해석하였다. 특히 와이어 레이스식 슬루잉 링 베어링은 우수한 마찰특성 때문에 건설기계, 하역기계, 광산기계나 탱크와 같은 국방무기 등에서 널리 사용되고 있다. 접촉면의 변형에 따른 일체형의 볼 베어링은 마찰력과 기울기면에서 와이어 레이스식 베어링에 비하여 크고, 같은 와이어 레이스식 베어링에서는 마찰력의 경우 볼 타입이 로울러 탕입에 비하여 약간 크게 나타났다. 이들의 계산결과를 종합하면 와이어 레이스식 베어링이 일체형 베어링에 비하여 마찰특성이 우수하고, 특히 와이어 레이스 베어링중에서 로울러 타입은 마찰 토오크면에서 균일하기 때문에 베어링을 사용한 제어기능 설계에서 특히 우수한 결과를 제공할 수 있다. 유한요소 해석결과는 기존의 실험결과와 잘 일치하고 있어서 슬루잉 링 베어링의 최적설계에 유한요소 해석의 유용함을 확인하였다. 또한 상부 구조물과 하부 구조물을 연결하기 위한 체결볼트의 구멍은 하중조건에 따라서 구조적 불안정성을 야기할 수 있음도 확인하였다.

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A Study on the Superfinishing of Ball Bearing Race (볼베어링 레이스면의 슈퍼피니싱에 관한 연구)

  • 이재우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.879-882
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    • 1997
  • This paper aims to clarify the effect of the sol-gel sintered alumina grain and the PbO content of binder on the performance of the vitrified alumina stone for superfinishing the ball bearing race with the vitrified alumina superfinishing stone. The main conclusions obtained were as follows. The stone that contain 8- 11% PbO in binder shows the highest grinding ratio, and increasing or decreasing the PbO contents causes lower grinding ratio. When superfinishing with the stone using the 45% fused alumina and 55% sol-gel sintered alumina grain, the grinding ratio becomes the best, the other ratio of grain contents shows lower performance. With increasing the bending strength of stone, the grinding ratio becomes larger. The roughness of the finished surface is the lowest in case of using the stone of the above mentioned conditions.

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Breakdown of Resistance of Rice Cultivars by New Race KI-1117a and Race Distribution of Rice Blast Fungus During 1999~2000 in Korea (도열병균 새로운 레이스 KI-1117a에 의한 저항성 품종의 이병화 및 레이스 분포변동(1999~2000))

  • 한성숙;류재당;심홍식;이세원;홍연규;차광홍
    • Research in Plant Disease
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    • v.7 no.2
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    • pp.86-92
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    • 2001
  • This experiment was carried out to analyze the recent epidemic of rice blast in southern provinces of Korea in 1999 and 2000. Incidences of leaf blast and panicle blast in these years were 1.5 and 2.9 times greater than those in 1998, respectively. Cultivation areas of rice cultivars, Daesan, Ilmi and Dongan bred from Milyang 95 as a recurrent parent increased over the country from 11% in 1998 to 38.4% in 2000, which were grown in more than 85% of total paddy fields in Jeonnam province. Predominant race populations of Pyricularia grisea in the farmers' fields had been changed from KJ-301 to KI-1117 in 1999 and KI-1113 and KJ-105 in 2000. Distribution ratio of the KI-1117 race in 1998 in the southern provinces was 1.7%, but increased to 30% in 1999. Although the cultivars Daesan, Ilmi and Dongan have shown wide spectrum of resistance to many races including KJ-301, they were susceptible to such races as KI-1117, KI-1113 and, KJ-105. These three races could be further classified into two sub-races, KI-1117 and KI-1117a, KI-1113 and Kl-1113a, and KJ-105 and KJ-105a based on virulence to Daesan. The newly classfied races, Kl-1113a, Kl-1117a, and KJ-l05a were also pathogenic to Ilmi and Dongan. This indicates that rice blast epidemic in southern provinces in 1999 and 2000 resulted from the breakdown of the resistance of Daesan, Ilmi and Dongan by the rapid increase of virulent races KI-1117, KI-1113, KJ-105 and their new sub-races.

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Relation between applied forces and surface characteristics on surface rolling in cast iron (주철의 표면로울링에서 가압력의 영향)

  • 육굉수;박병성;최재승
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.4
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    • pp.705-711
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    • 1988
  • Surface rolling is one of the plastic deformation processes, which improves surface roughness and increases hardness. The surface rolling tool used in this experiment was specially designed by author for surface rolling on cast iron. The cutting feeds were 0.10mm/rev.and 0.30mm/rev.The applied forces of rolling were in the range of 10kgf to 30kgf with 5kgf differences. The results obtained are as follows. (1) In general the good surface roughness can be obtained with the applied force 25kgf according to surface roughness of the previous turning. (2) The hardness is mainly increased at the first rolling process and is more increased with the increasing applied forces. (3) The reduction of the diameter heavily depends on the original surface roughness. That is, the larger surface roughness is, the larger is the reduction is the reduction of diameter.

An Investigation on Structural Analysis of Feldspars by Electron Diffraction Patterns (전자회절도형을 이용한 장석의 구조 분석에 대한 고찰)

  • 김윤중;이영부;박병규;이정후
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.2
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    • pp.177-187
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    • 2004
  • Measurements of the lattice parameters of albite and oligoclase from electron diffraction patterns with the Au internal standard resulted in errors of less than 1 %. An electron diffraction map for natural oligoclase samples was constructed and 11 stations of zone-axes diffraction patterns were obtained. This process is indispensible for reliable TEM studies of triclinic feldspars. Utilizing the [001] cleavage plane of feldspar and the double-tilting TEM holder the following information is obtainable: Si-Al ordering and chemistry of alkali feldspars could be estimated from the $\alpha$* - * plot, where * is measured from the [001] orientation, while $\alpha$* is measured from the [100] orientation. Si-Al ordering of Na-rich plagioclase could be estimated from * [001] patterns. Structure and chemistry or Na-poor plagioclase could be estimated from existence of e-reflections, their intensity variations as well as their positional changes.

Antirapakivi Mantled Feldspar of the Albong Trachyandesite from Ulleung Island, Korea (울릉도 알봉조면안산암에서 산출되는 안티라파키비조직 장석의 성분)

  • Sung-Hyo Yun
    • Journal of the Korean earth science society
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    • v.43 no.6
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    • pp.737-748
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    • 2022
  • In this study, the composition of feldspar phenocrysts observed in the Ulleungdo Albong trachyandesite lava dome was identified by performing point and X-ray element mapping surface analysis (EPMA). Plagioclase, which appears as a phenocryst in the Albong trachyandesite, corresponds to bytownite and labradorite, and andesine, and lath in the microphenocrysts and the matrix corresponds to andesine to oligoclase. Alkali feldspar mantled around plagioclase phenocrysts and microphenocrysts correspond to anorthoclase and sanidine. Plagioclase phenocrysts with a distinct zonal structure represent a normal structure in which the An content of the zoning decreases from bytownite to labradorite or andesine as it moves from the center of the phenocrysts to the edge. The edge of the phenocryst is surrounded by alkali feldspar, showing an antirapakivi texture. X-ray mapping of feldspar phenocrysts showed a typical antirapakivi texture. Normal zoning with distinct zoning showing a difference in component composition was clearly shown. The edges were mantled with alkali feldspar, and antirapakivi represents the texture. The antirapakivi texture of feldspar in the Albong trachyandesite may have been formed in the mixing system when alkali feldspar crystallized and mantled around plagioclase phenocrysts and microphenocrysts. This is because plagioclase phenocrysts and microphenocrysts in magma that had already crystallized are more mafic than trachyandesite magma.

종료종모돈이 3원 교잡종의 육질에 미치는 영향

  • 최임수
    • 종축개량
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    • v.20 no.1
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    • pp.93-102
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    • 1998
  • 3원교잡종의 지육지방축척과 육질에 대한 종료종모돈(두록종:D, 버크셔종:B, 매산돈:M)의 영향을 보기 위해, 랜드레이스종과 대요크셔종의 F1(LW) 종빈돈에 D, B 또는 M종의 3품종의 종모돈을 교배시켜 얻은 3원교 잡종(LWD, LWB, LWM)에 대해서 지육의 지방 축적량, 로스육의 물리적 특성과 화학적 조성 또는 근육섬유의 특성, 근육과 피하지방의 지방산 조성을 비교 검토했다. 시험돈은 3원교잡종 각각에 대해서 거세돈 수컷과 암컷을 각각 6두씩, 합계 36두를 공시했다. 단사(單飼), 무제한 급여 하에서 체중이 30kg에서 105kg가 될 때까지 사육했다. 도살한 돼지의 지육우반환(枝肉右半丸)의 제5-6, 8-9, 11-12, 13-14 흉추(胸椎) 간, 제16흉추-제1요추(腰推) 또는 최후요추-제1선추(仙推)간의 횡단면지방의 면적비율은 어떠한 부분에도 LMW이 LWD, LWB보다 통계적으로 유의가 많았다. 로스육의 물리적 특성치인 Tenderness는 $LWM961.3Kgw/cm^2)$ of $LWD(84.13KgW/cm^2)$$LWD(87.22KgW/cm^2)$보다 유의적으로 부드럽고, Pliability는 역으로 LWM이 LWD, LWB보다 유의 있게 낮았다. 또 로스육의 근육내 지방함량은 $LWM(3.23\%)$$LWD(2.32\%)$$LWB(2.35\%)$보다 유의성 있게 많았고, 가열 손실율(加熱損失率)은 LWM이 LWD, LWB보다 유의성 있게 높았다. 근섬유경(筋纖維經)은 LWD가 LWB, LWM보다 큰 경향으로 인정되어 지고, 근속(筋束)의 횡단면적은 LWD가 LWB 또는 LWM보다 유의 있게 조밀했다. LWM은 근육 내 지방산인 오레인산이 LWD, LWB보다 훨씬 높았고, 불포화 지방산의 비율이 높았다. 이상의 결과 종료종모돈이 3원교잡종의 육질에 영향을 미친다는 것이 명확하게 되었다.

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A Study on the Contact Force of Rubber Seals for Ball Bearings (볼 베어링용 고무시일의 접촉력 해석에 관한 연구)

  • 김청균;전인기;최인혁
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.12
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    • pp.2261-2267
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    • 1992
  • The equations are derived for the evaluation of the axial contact force. The contact forces for rubber seals are analyzed as a function of the ratio of real contact length, the thickness of seal lip, the inclined angle of seal lip, and the interference between the edge of seal lip and the rotating inner ring. The design data for rubber seals are presented in terms of the ratio of real contact length, initial inclined lip angle, lip thickness and the interference. The calculated results show that the deflected interference and the circumferential stress cause considerable change of contcat forces for the low sealed pressure.

A Study on the Effects and Value Analysis of the B2B e-Commerce Guarantee Service (B2B 전자상거래 보증 서비스의 효과 및 가치 분석)

  • Han, Chang-Hee;Kim, Min-Kwan;Lim, Chang-Kyu
    • The Journal of Society for e-Business Studies
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    • v.15 no.4
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    • pp.265-284
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    • 2010
  • B2B e-commerce guarantee service is a guarantee service combining the electronic systems among Korea Credit Guarantee Fund(KCGF), banks and e-marketplaces to process all procedures on internet ranging from application for credit guarantee, issue of written guarantee and contracting for a commerce to payment. B2B e-commerce guarantee service plays as an intermediary role in financial support for small and mediumsized enterprise(SME), which are small size, low credit level, and unfavorable status in many aspects compared to major companies. Despite the B2B e-commerce guarantee service has various advantages conducive to promotion of e-commerce among small and medium businesses as well as development of e-commerce itself, it has yet to be diffused due to lack of acknowledgement, misunderstanding of its functions and vague psychological fear of the on-line settlement. Thus, this study identifies the values and effects of the B2B e-commerce guarantee service using financial data and cases. The process of this study is 4 phase. first phase is analysis of B2B e-commerce guarantee service and e-Marketplace. second phase is analysis of performance from the Perspective of Diverse Participants. third phase is analysis of economic performance and support for SME. last phase is policy suggestions and conclusion.

A Study on the Marketplace Models for Korean Animation Content Foreign Sales (국산 애니메이션 콘텐츠 해외 판매를 위한 마켓플레이스 모델 연구)

  • Han, Sang-Gyun
    • Cartoon and Animation Studies
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    • s.44
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    • pp.333-361
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    • 2016
  • In general, content business companies include animation industry can have benefits, which they have higher incomes when they obtain wider markets. Therefore, they pursue to have diverse windows for content distribution or to reach the foreign markets for dealing their content products with potential customers. It have the greatest value. They can re-invest the incomes to produce their new products, and they can enhance the international competitiveness of their next products. As the results, the companies can have more incomes and wider markets in next business, and it will be the effectiveness of the good cycle of the animation industry. Animation industry has being undergone of its structure changes, more economical chances and viewers' attitudes changes through the all over the industry because of the acceptance of new digital technology. To response the changes or have the new chances from the changes, they should to review the existing system and the law concerned with the animation business as well as having the diverse new plans for supporting the industry like a construction of the online marketplace of Korean animation. It would make the Korean animation companies to meet foreign customers easily by making lower the entrance barrier of the foreign markets. Current Korean government needs to estimate the value of the Korean animation accurately and objectively by concerning its surroundings to support efficiently. However, it is very difficult to estimate the value of the content rightly because of its' intangible and subjective matter. For this, they should analyze the all the data of the information of the Korean animation content by accumulate, open to the public and manage. So if the government makes online marketplace for the Korean animation, which all the Korean animation companies get in, it would be a solution of estimating the value of the Korean animation rightly. In addition, it will be used as the role of archive of the government to lead the industry successfully. As a point of the small size of the Korean animation companies, they are government dependable because of its low budget, so they strongly expect the government to do the right role as the unique knowledge distributor. Therefore, the Korean animation online marketplace would make not only big companies, but also small companies to have the chances to increase the value of their content in the global markets by themselves without economic burdens.