• 제목/요약/키워드: quality of contact

검색결과 825건 처리시간 0.033초

집전성능 향상을 위한 팬터그래프-전차선의 주요 설계 파라미터분석 (Analysis of the Major Design Parameters of a Pantograph-Railway Catenary System for Improving the Current Collection Quality)

  • 조용현
    • 한국철도학회논문집
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    • 제17권1호
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    • pp.7-13
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    • 2014
  • 팬터그래프와 전차선 사이의 이선을 유발하는 주요 요인은 팬터그래프로 인하여 전차선에 야기되는 파동의 전파와 반사 그리고 열차 진행방향의 전차선로 강성변화이다. 본 논문의 목적은 200km/h급 일반철도와 300km/h급 고속철도에서 이선을 효과적으로 줄이기 위하여 앞서 언급하였던 두 가지 요인 중에서 어느 쪽을 중요하게 고려해야 하는지를 분석하는 것이다. 고속철도 경우에는 파동의 전파와 반사가 강성 변화에 비하여 집전성능에 영향을 더 크게 미친다. 증속을 위해서는 드로퍼 경량화와 전차선 고 장력 부여를 위한 고 강도 전차선 개발이 필요하다. 파동전파속도를 향상하기 위하여 조가선의 장력을 증가시키면 오히려 집전성능을 악화할 수 있음에 유의해야 한다. 200km/h급 일반철도의 경우에는 전차선로 강성 변화가 파동 전파 및 반사에 비하여 집전성능에 영향을 더 미치므로 강성변화를 완화시키기 위하여 경간길이 축소, 전차선로의 장력 증가 및 드로퍼배치 최적화가 필요하다.

푸드서비스산업에서 고객지향적인 서비스 컨택요소의 탐색적 연구 (Exploratory Study on Customer-Oriented Service Contact Elements in Foodservice Industry)

  • 한명애;정유경
    • 대한영양사협회학술지
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    • 제21권1호
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    • pp.72-82
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    • 2015
  • The purpose of this study was to provide preliminary data for competitive dominance in an institutional foodservice environment. Data were collected from 85 experts and practitioners on customer-oriented service contact elements and contact fields in the foodservice industry. PASW Statistics ver.18 and MS Excel were used for data analysis. From the pilot study, 67 service contact-elements were derived. Contribution rate analysis and frequency analysis in each contact field were performed in order to categorize four factors, including environment-oriented contact, product-oriented contact, service-oriented contact, and image-oriented contact fields. Thirty three contact elements were derived, and environment-oriented contact consisted of eight contact-elements (cleanliness of restaurant/kitchen, etc.), product-oriented contact consisted of twelve contact-elements (food taste, etc.), service-oriented contact consisted of seven contact-elements (service quality, etc.), and image-oriented contact consisted of six contact-elements (image/reputation, etc.). The results of study will be useful to develop an effective marketing program for competitive dominance in an competitive foodservice industry environment.

Development of an Inspection System of Contact Light Emitting Device for Quality Control

  • Lee, Jun-Ho;Kwon, Hyung-Kee;Ryu, Young-Kee
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.118.3-118
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    • 2001
  • CLED (Contact Light Emitting Device) has three layers consisting of a transparent electrode, a light emitting layer and a substrate. When the substrate of the CLED comes in contact with a fingerprint under AC input voltage, it makes an electric field between the fingerprint and the device. Due to the electric field, the light is emitted along the ridgeline of the fingerprint. The intensity along the ridge on the surface of the CLED increase in proportion to the electric field. To achieve uniform performance of fingerprint verification devices, inspection system of CLED for quality control were required. In this research, we proposed the factors for quality controls such as dimensions of the CLED, uniformity ...

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튜브 배열에 따른 튜브/튜브시트 수압 확관 접합의 민감도 해석 (Sensitivity Analysis on Hydraulic Expanded Tube-to-Tubesheet Joints for Tube Layout Patterns)

  • 김동영;김태완
    • 대한기계학회논문집A
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    • 제23권11호
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    • pp.1896-1903
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    • 1999
  • The basic requirements to improve the joints quality of tube-to-tubesheet for heat exchangers are to obtain high residual contact pressures between the tubes and the tubesheet as well as low residual stresses in the transition zone of the tubes. The residual contact pressures and residual stresses which govern the joint quality are influenced by parameters such as material properties, geometric dimension of tube and tubesheet and expansion pressures. There are two types of tube layout patterns, triangular and square, which are frequently used for heat exchangers. The purpose of the present work is to examine the superior tube layout patterns considering the joints quality by comparing numerical results from sensitivity analyses which were performed for both of tube layout patterns.

균일 화상 품질 구현을 위한 닥터 블레이드 접촉압력 근사모델링 (Approximate Modeling of Doctor Blade Contact Pressure for Realization of Uniform Image Quality)

  • 최하영;박승찬;이종수
    • 한국생산제조학회지
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    • 제22권2호
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    • pp.241-247
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    • 2013
  • The doctor blade is equipped in a toner cartridge and is a device to maintain the uniform thickness of a toner by controlling the pressure on the developing roller. The contact pressure between the developing roller and the doctor blade is one of the significant factors for image quality and durability of toner cartridge. The purpose of this study is to develop approximation model in order to minimize the time and cost which are needed much required in making optimal design of the doctor blade. Central composite design was used for the design of experiment and response surface design was used for approximation. The data for contact pressure were acquired through finite element analysis and data of image density and toner weight were acquired through experiment. The approximation model developed in this study has presented very high fitness.

Skin Contact와 Suspended Solid가 백포도주 품질에 미치는 영향 (The Effects of Skin Contact Time and Suspended Solid on The White Wine Quality)

  • 노태욱;김찬조;성창근;문영자;김복난;오만진
    • 농업과학연구
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    • 제24권2호
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    • pp.290-297
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    • 1997
  • Danored is considered as the most favorable grape variety for national wine manufacturing in terms of sugar, organic acid contents, annual production amount, as well as quality control convenience after harvest. This study was canied out to know the influence of suspended solid(SS) and skin contact time(SCT) with Danored variety on the white wine quality. The results are summarized as follows; 1. Suspended solid and skin contact time did not greatly influence on the chemical composition of Danored juice. But skin contact time provided slightly increaseness to the content of phenol compounds 2. Suspended solid accelerated fermentation rate of white wine manufacturing. Although the content of suspended solid are less amount than 0.3% in must, wine fermentation was completed to dryness in concentration of sugar. 3. When the content of suspended solid was around 3%, higher alcohol in white wine was increased by the 20%. This result is relatively small increasement compared to the other reported results. 4. Because Danored contained less amount of phenol compounds comparison with other grape varieties, browning capacity in white wine was much favorable to quite low concentration. Especially, phenolic compounds was decreased remarkably as one of fermentation characteristics of Danored variety. 5. As a result of sensory evaluation, wine quality was A-1> B-1> A-2> B-2 in its favorable ranking orders. It was so concluded that A-1 might be the most acceptable one from this study.

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Reduction of metal-graphene contact resistance by direct growth of graphene over metal

  • Hong, Seul Ki;Song, Seung Min;Sul, Onejae;Cho, Byung Jin
    • Carbon letters
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    • 제14권3호
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    • pp.171-174
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    • 2013
  • The high quality contact between graphene and the metal electrode is a crucial factor in achieving the high performance of graphene transistors. However, there is not sufficient research about contact resistance reduction methods to improve the junction of metal-graphene. In this paper, we propose a new method to decrease the contact resistance between graphene and metal using directly grown graphene over a metal surface. The study found that the grown graphene over copper, as an intermediate layer between the copper and the transferred graphene, reduces contact resistance, and that the adhesion strength between graphene and metal becomes stronger. The results confirmed the contact resistance of the metal-graphene of the proposed structure is nearly half that of the conventional contact structure.

연마 브러시 접촉력 산출 (Contact Force Estimation for a Polishing Brush)

  • 이병수
    • 한국정밀공학회지
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    • 제27권1호
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    • pp.58-63
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    • 2010
  • A new contact force estimation technique is proposed. Keeping the contact force at a certain level between finishing tool and the object is essential since the quality of the finished surface is very sensitive to the contact force during the finishing process. However, the contact force measurement cannot be obtained by simply installing load cells under machine table or in the middle of tool linkage. The reason is that the weight of the machine table and the tool linkage are much heavier than the force to be measured. To that end, a method for estimating disturbance is proposed for a system that is similar to the mechanism of the finishing machine, and the same method is applied to estimate the contact force of the brush-type finishing machine. To verify the effectiveness of the proposed method, a small scale test set-up has been built and the method has been tested.

실차시험을 통한 팬터그래프 커버가 고속열차의 집전성능에 미치는 영향에 대한 분석 (Analysis of Effect of Pantograph Cover on the Current Collection Quality of High Speed Train using Real Train Experiment)

  • 오혁근;김석원;조용현;곽민호;권삼영
    • 한국철도학회논문집
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    • 제19권4호
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    • pp.409-416
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    • 2016
  • 팬터그래프와 전차선간의 접촉력 특성은 열차의 집전성능을 나타내는 중요한 특성으로서 국제규격에 따른 엄격한 관리가 필요한 항목이다. 최근에는 소음저감 커버가 고속열차의 팬터그래프 주위에 설치가 되고 있으나 팬터그래프 커버에 의한 접촉력 특성에 대한 연구는 거의 수행되지 않았다. 본 연구에서는 차세대고속열차(HEMU-430X)를 이용하여 팬터그래프 커버가 팬터그래프의 집전성능에 미치는 영향을 동적 접촉력 측정을 통하여 분석하였다. 그 결과 팬터그래프 커버가 부착이 되면 300km/h 주행 시 평균접촉력이 약 50N 낮아짐을 확인하였다. 또한 정적압상력을 제외한 순수한 팬터그래프 커버 유무에 의한 평균접촉력의 차이는 300km/h에서 최대 110N까지 측정되었다. 한편 팬터그래프 커버에 의하여 접촉력 표준편차가 약 3~5N 변화하는 것도 확인하였다.

종업원의 고객에 대한 배려행동이 서비스 충성도에 미치는 영향: 미용실서비스와 패스트푸드서비스의 비교적 접근 (The Effect of Employees' Social Regard on Service Loyalty: Comparative Approach of Beauty Services and Fast-food Services in Service Settings)

  • 성윤옥
    • 한국콘텐츠학회논문지
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    • 제14권1호
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    • pp.409-422
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    • 2014
  • 본 연구의 목적은 고객에 대한 배려가 전반적인 서비스품질, 서비스 만족과 서비스 충성도에 대한 영향력을 검증함으로서, 서비스에서 종업원의 고객에 대한 배려 행동이 충성도 형성 과정에 미치는 영향을 설명하였다. 또한 고객에 대한 배려의 전반적인 서비스품질과 만족에 대한 영향이 서비스 접촉수준이 높은 미용실 서비스와 낮은 패스트푸드 서비스 사이에 차이가 난다는 것을 검증하였다. 본 연구는 미용실 서비스와 패스트푸드 서비스를 이용한 경험을 가진 소비자를 대상으로 자료를 수집하였으며, Amos 18.0 통계패키지를 이용한 구조방정식 모형분석으로 연구가설을 검증하였다. 연구결과는 다음과 같다. 첫째, 고객에 대한 배려는 전반적인 서비스품질과 서비스 만족을 통해 충성도에 영향을 주며, 또한 직접적으로 서비스 충성도에 영향을 주는 것으로 나타났다. 둘째, 접촉수준의 차이에 따라 접촉수준이 높은 미용실 서비스에서 고객에 대한 배려의 만족에 대한 영향이 더 크게 나타나는 것을 확인하였다. 즉, 종업원과의 접촉수준이 좀 더 빈번한 서비스에서 종업원의 고객에 대한 배려 행동이 고객 만족을 향상시키는데 중요하다는 것을 확인하였다.