• 제목/요약/키워드: Rolling Behavior

검색결과 330건 처리시간 0.042초

A FEM Analysis of Dynamic Behavior for a Slider with Curvature Effect

  • 임성근;임윤철
    • KSTLE International Journal
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    • 제5권2호
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    • pp.44-48
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    • 2004
  • A new type slider with optical components is going to be introduced on market for portalbe and high capacity disk drive, and it will show a great potential for high performance drive in the paper the dynamic behavior and static characteristics of silder for a small form factor optical disk drive have been investigated numerically by an in-house simulation code using FEM. A curvature effect is found when a slider is applied to a relatively small disk, which makes rolling characteristics worse due to the negative pressured generated at the air bearing surface because of the curvature of small disk diameter.

Fatigue Crack Growth Behavior for Welded Joint of X80 Pipeline Steel

  • Kim, Young-Pyo;Kim, Cheol-Man;Kim, Woo-Sik;Shin, Kwang-Seon
    • 비파괴검사학회지
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    • 제29권1호
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    • pp.43-48
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    • 2009
  • The fatigue crack growth behavior of high strength X80 pipeline steel was investigated with compact tension specimens that crack growth directions were aligned either parallel or normal to the rolling direction of the pipeline. Also, the fatigue crack growth rates for welded joint of X80 pipeline steel were investigated with compact tension specimens that crack growth directions were aligned either parallel or normal to the welding line. The experimental results indicated the fatigue crack growth behavior was markedly different in three zones, weld metal, heat affected zone and base metal of welded joints. There was a trend toward increment in the fatigue life of weld metal and heat affected zone as compared with the X80 pipeline steel.

일부 대학생의 자아존중감과 칫솔질 행위 (Self Esteem and Toothbrushing Behavior in College Students)

  • 김민아;김희천
    • 한국보건간호학회지
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    • 제14권1호
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    • pp.1-11
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    • 2000
  • The purpose of this study was to examine self-esteem and toothbrushing behavior in college students. The research was conducted from August 26 to September 16. 1999. Totally 1003 students consisted of whom 875 in college and 128 in university were surveyed. Questionnaires including period. frequency. method. and time of toothbrushing and self-esteem were obtained. The data were analysed by descriptive statistics. t-test, Pearson Correlation Coefficient and ANOVA. A significant level of statistical difference was 5 percent. The results were summarized as follows: 1. The average score of self-esteem was $28.358\pm4.928$. 2. The average score of toothbrushing behavior $52.63\pm11.12$. 3. 54.8 percent of the students who were surveyed reported that they brushed their teeth after breakfast and after dinner. 42.9 percent did so twice a day. and 50.2 percent did Rolling method. 4. The Pearson Correlation Coefficient between the self esteem and toothbrushing behavior showed a positive correlation(p=.005), 3. The level of self-esteem was significantly varied with toothbrushing period (p=.000), toothbrushing frequency (p=.020)' and toothbrushing time (p=.003). From the above findings. we found out self-esteem might play a significant role in mediating changes in oral health behavior.

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탄성 유체 윤활에서의 액정의 마찰 특성 및 유막두께 (Frictional Behavior and Film Thickness of Some Liquid Crystals in Elastohydrodynamic Lubrication)

  • 이희성
    • Tribology and Lubricants
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    • 제18권4호
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    • pp.255-259
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    • 2002
  • The tribological properties of eight different liquid crystals were investigated in a concentrated point contact device and a ball-on-flat contact. For comparison, the same tests were also performed with commercial greases and the corresponding base oils. Under the fully flooded conditions studied, liquid crystals in a concentrated point contact showed lower friction than commercial greases and greater film thickness dependence on rolling speed than grease base oils or greases. Test results also showed that the film thickness and friction were little influenced by the composition of the examined liquid crystals.

Endothelin-1이 유발하는 stereotyped behavior과 arterial blood pressure 상승에 NMDA receptor와 NO의 관련성

  • 류정수;방준석;허인회
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1997년도 춘계학술대회
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    • pp.92-92
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    • 1997
  • Stereotaxic apparatus를 이용하여 흰쥐의 두개골을 천공하여 periaqueductal gray matter에 정확히 cannula를 삽입하여 1일 이상의 방치후 여기로 약물을 투여하여 일군의 동물들은 행동의 변화를 관찰하고, 일군의 동물들은 경동맥에서의 혈압과 심박수의 변화를 관찰한다. 결과: ET-1에 의해 유발된 barrel-rolling은 NMDA receptor-selective antagonist인 MK-801에 의해 유의성있게 억제되었으며, NOS antagonist인 L-NAME과 NO scavenger인 Hemoglobin에 의해서도 유의성 있게 억제되었다.

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Effectiveness of classical rolling pendulum bearings

  • Raftoyiannis, Ioannis G.;Michaltsos, George T.
    • Coupled systems mechanics
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    • 제6권2호
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    • pp.127-139
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    • 2017
  • During the last decades, Pendulum Bearings with one or more concave sliding surfaces have been dominating bridge structures. For bridges with relative small lengths, the use of classical pendulum bearings could be a simple and cheaper solution. This work attempts to investigate the effectiveness of such a system, and especially its behavior for the case of a seismic excitation. The results obtained have shown that the classical pendulum bearings are very effective, mainly for bridges with short or intermediate length.

통계적 에너지 해석법을 이용한 KTX차량의 실내소음 해석 (Analysis of Interior Noise for KTX Train using SEA)

  • 김재철;이찬우;최성훈
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.783-788
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    • 2004
  • Recently, Statistical Energy Analysis(SEA) is being increasingly applied to describe vibro-acoustic behavior of complex structures, such as air plane, automobile, ship, building. In this paper, we discuss the application of SEA to predict the interior noise for KTX train. To validate the SEA model of KTX train, calculated the interior noise for motorized car is compared to measured one. Finally, the reduction measures of interior noise for KTX are also discussed.

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Control of Platelet Rolling and Adhesion

  • Moskowitz, Samuel E.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.77.1-77
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    • 2002
  • Platelets arrest bleeding and repair damaged blood vessels. The purpose of this paper is to formulate a mathematical model for the control of platelet adhesion within the vasculature consistent with experimental findings, particularly those of Frenette, Ruggeri , Savage, Yuan, Lawrence and Springer. In addition to providing some, albeit rudimentary, insight into the behavior of platelets, a numerical simulation of this theoretical model may be useful in a systematic study of pathological cases. Glycoprotein receptor complex (GPIb/V/IX), found on the platelet surface membrane, binds to the adhesive protein and ligand von Willebrand factor (vWf), located within the sub-endothelium. The binding...

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볼스크류를 이용한 유정압테이블의 고정밀위치 결정

  • 황주호;박천흥;이후상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.288-292
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    • 1997
  • Positioning accuracy largely depends on the variation of friction force in guide table, geometric accuracy of feed unit like as ballscrew and controllable accrecy of servo unit, in general. This paper deals with improvement of microstep resolution about hydrostatic table. Torque control mode have a advantage in microstep test, and more stable than velocity control mode in low velocity motion. Hydro static table have the elastic behavior within several .mu.m, so different character exist between the elastic motion and rolling motion. Integral gain is dominant than other gain in elastic motion. In order to improve response time in elastic motion,increasing gain is suggested within the stable region.