• 제목/요약/키워드: Multiple contact

검색결과 441건 처리시간 0.027초

고분자전해질막 연료전지의 공기유로 내에서의 다중 액적 거동에 대한 수치적 연구 (NUMERICAL STUDY OF MULTIPLE DROPLET DYNAMICS IN A PEMFC AIR FLOW CHANNEL)

  • 최지영;손기헌
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 춘계학술대회논문집
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    • pp.159-164
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    • 2009
  • The water droplet motion and the interaction between the droplets in a PEMFC air flow channel with multiple pores, through which water emerges, is studied numerically by solving the equations governing the conservation of mass and momentum. The liquid-gas interface is tracked by a level set method which is based on a sharp-interface representation for accurately imposing the matching conditions at the interface. The method is modified to implement the contact angle conditions on the walls and pores. The dynamic interaction between the droplets growing on multiple pores while keeping the total water flow rate through pores constant is investigated by conducting the computations until the droplet motion exhibits a periodic pattern. The numerical results show that the droplet merging caused by increasing the number of pores is not effective for water removal and that the contact angle of channel wall strongly affects water management in the PEMFC air flow channel.

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Smart Multiple-Tap System Based on WiFi for reduction of Standby-Power

  • Jeon, Jeong-woo;Yi, Mira
    • 한국컴퓨터정보학회논문지
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    • 제22권6호
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    • pp.123-129
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    • 2017
  • In this paper, we proposed a smart multiple-tap system which a remote user with smartphone can control multiple-taps in order to reduce standby-power consumption more conveniently when plugged-in electric appliances are turned-off. Recently, several researches of smart multiple-tap using IoT technology has reported. However, in these researches, an additional device like as a server computer is necessary, or multiple-taps could be only remotely controlled by smartphone and not directly controlled by on/off switch. The proposed smart multiple-tap system does not need any additional device only if it has a WiFi router, and it can be used for user as well as remote control using smartphone application and physically direct control using contact switches like existing multiple-taps. Our approach is to develop a smart multiple-tap device capable of WiFi communication can each serve as a server or a client, and can be operated by the hybrid switch combining the on/off contact switch and the relay switch. We implemented the prototype of the proposed system composed of the smart multiple-tap device and the smartphone application, and the test of the prototype validates the proposed system.

화폐상 습진에 병발한 급성 알레르기성 피부염 한방 치험 1례 (A Case of Acute Allergic Contact Dermatitis with Multiple Nummular Eczema)

  • 장인욱;장정현;윤화정;고우신
    • 한방안이비인후피부과학회지
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    • 제27권4호
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    • pp.243-250
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    • 2014
  • Objective : The purpose of this report is to know the effect of oriental medical treatments on acute allergic contact dermatitis with multiple nummular eczema. Methods : We treated a 34-years-old woman patient with acute allergic contact dermatitis on face and multiple nummular eczema on both arm, right ankle and left inguinal region by Korean medicine. After Korean medical treatment for 42 days in hospital, we measured the decrease of exudation and pruritis as well as recovery of skin damages. We recorded pictures of changes on symptoms. Results & Conclusion : The symptoms of ACD and nummular eczema were significantly improved except scars. Exudation and pruritis were disappeared and skin damages were almost recovered until discharge from hospital. After 20 days we could confirm the symptoms were clearly disappeared. Thus Korean medical treatments are effective on ACD and nummular eczema.

Non-destructive estimation of soluble solids in the intact melon fruits from cross progeny by non-contact mode with a fiber optic probe

  • Ito, Hidekazu;Fukino, Nobuko
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1524-1524
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    • 2001
  • A previous paper(Ito et al., 2000) has described the improvement of the standard error(SEC and SEP) of the predicted soluble solids(Brix) in a melon cultivar by non-contact mode with a fiber optic probe. Then we examined the immature and mature fruits. The objective of this study was to determine if non-contact mode could improve the standard error of the predicted Brix of matured melon fruits from cross progeny as well as the contact mode(usual method). The optical absorption spectrum was measured using a NIR Systems model 6500 spectrophotometer. A commercial spectral program(NSAS ver. 3.27) was used for multiple linear regression analysis. Absorbances of 902 and in the vicinity of 877 nm were included as the independent variables in both multiple regression equations. These wavelengths are key wavelengths for non-destructive Brix determination. When the results for the contact mode and non-contact mode are compared, the latter mode improved the former standard error(SEP and RMS).

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전자접촉기 열화에 따른 전기적 특성 분석 (Analysis of Electrical Characteristics Due to Deterioration of Electromagnetic Contactor)

  • 최순호
    • 한국전기전자재료학회논문지
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    • 제32권5호
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    • pp.407-412
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    • 2019
  • In this paper, the changes in the electrical characteristics (arc energy, contact resistance, and bouncing phenomenon) due to the deterioration of the contact are analyzed. The results are generally consistent and can be analyzed for contact deterioration. The results of the experiment demonstrate that the arc energy is linearly related to the current when the contact samples and the voltage conditions are the same. The contact resistance varies due to multiple factors, but is generally within a certain range, and the contact deterioration can be determined. Contact stabilization can be detected by the decrease in the bouncing phenomenon due to deterioration (the change of the shape of the contact).

비부착형 포스트텐션 구조의 모델링기법 (Modeling Technologies for Unbonded Post-Tension Systems)

  • 강현구;나창순
    • 한국전산구조공학회논문집
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    • 제24권1호
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    • pp.33-41
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    • 2011
  • 본 연구에서는 비부착형 포스트텐션 시스템의 해석에 적용할 수 있는 모델링기법을 제시하였다. 모델링은 유한요소 해석 프로그램을 이용하였으며, tube-to-tube contact 요소를 도입하여 강연선의 물리적 형상을 직접적으로 모델링하는 방법과 실제의 강연선 외에 가상의 강연선을 콘크리트에 매입하고, 두 개의 강연선을 스프링으로 연결하여 간접적으로 모델링하는 방법을 동시에 제시하고 비교하였다. 콘크리트의 인장경화 현상을 무시하였을때 두 모델링기법에서는 거의 동일한 결과를 제공하지만 콘크리트의 인장경화를 고려한 경우에는 스프링을 이용한 간접적인 모델링기법을 통해서만 결과를 얻을 수 있었으며, 결과 또한 콘크리트의 경화현상을 고려하지 않은 경우와 다소 상이하였다. 비교를 통하여 비부착형 포스트텐션 시스템의 모델링기법으로 스프링을 이용한 모델링기법을 최종적으로 선정하고 기존의 실험적 연구에서 인용한 실험결과와 해석결과를 비교, 검증하였으며 또한 파라미터 스터디를 통해서 모델링의 적절성을 확인하였다.

Computer Simulations on the Thermal Behaviors of a Friction Pad in High-Speed Train Disk Brakes

  • Kim, Chung Kyun
    • KSTLE International Journal
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    • 제1권2호
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    • pp.95-100
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    • 2000
  • The thermal behaviors of disk-pad braking models has been analyzed for a high-speed train brake system using the coupled thermal-mechanical analysis technique. The temperature distribution, thermal distortion, and contact stress in the disk-pads contact model have been investigated as functions of the convective heat transfer rate. The FEM results indicate that multiple spot type pads show more stabilized thermal characteristics compared with those of the flat type pads for the increased convective heat transfer rate. The maximum contact stress for a friction pad loaded against a rubbing disk was occurred on the edge of the pad at the disk-pad interface.

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유학생 참여 기반 다문화 교육 프로그램이 간호대학 신입생의 문화 간 의사소통 능력과 간호전문직관에 미치는 영향 (Effects of a multicultural education program based on international students' participation on intercultural communication competence and nursing professionalism)

  • 홍경진;한정진
    • 한국간호교육학회지
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    • 제28권4호
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    • pp.389-399
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    • 2022
  • Purpose: This study aimed to develop a multicultural education program that includes contact with persons from multiple cultures and to report on the program's effects on intercultural communication competence and nursing professionalism. Methods: A multicultural education program that included contact with persons from multiple cultures was developed, and a quasi-experimental study was performed using a non-equivalent control group pretest-posttest design. The experimental group comprised 32 participants, and the control group comprised 26 participants. An online survey was conducted before and immediately after the intervention to collect data. Results: The experimental and control groups' mean scores for intercultural communication competence before the intervention were 3.67 and 3.84, respectively, while their mean scores for nursing professionalism were 3.87 and 3.69, respectively. After the intervention, both the intercultural communication competence score and the nursing professionalism score improved to 4.02 in the experimental group. The study demonstrated significant improvement in intercultural communication competence and nursing professionalism after the multicultural education program was conducted. Conclusion: The study's results demonstrate the need to develop a multicultural education program including contact and communication with persons from multiple cultures, such as international students, women who immigrated for marriage, immigrant workers, and multicultural families.

스위블 연결구용 멀티접촉패킹의 밀봉특성에 관한 유한요소해석 (FE Analysis on the Sealing Characteristics of Multi-Contact Packing for Swivel Joint)

  • 김청균
    • 한국가스학회지
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    • 제18권4호
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    • pp.51-55
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    • 2014
  • 본 연구에서는 한곳에서 접촉하는 오링과 여러 곳에서 접촉하는 멀티접촉패킹에 대한 밀봉특성을 유한요소법으로 해석하였다. FEM 해석결과에 의하면, LP가스압력 1.8MPa을 공급하였을 때 기존의 오링에서는 밀봉성에 관련된 2.5MPa의 수직접촉 최대응력을 발생하였다. 반면에 새롭게 고안된 멀티접촉패킹에서는 3.01MPa이 발생하여 20.4%나 높아진 밀봉성이 향상되었음을 알 수 있다. 또한, 밀봉내구 안전성에 밀접한 관련이 있는 압출현상은 기존 오링의 경우 1.62MPa의 가스압력에서 발생되었지만, 멀티접촉패킹에서는 1.8MPa 정도로 가스내압을 올려도 압출현상이 발생되지 않는 것은 오랫동안 밀봉작용을 한다는 것을 의미한다. 따라서 밀봉성과 내구안전성을 높게 요구할 때는 한곳에서 접촉하는 기존의 오링보다는 여러 곳에서 접촉하는 멀티접촉패킹을 사용하는 것이 유리함을 알 수 있다.