• Title/Summary/Keyword: rotary type

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Variability of Practice Effects in Transfer of Photoelectric Rotary Pursuit Task

  • Jeon, Hye-Seon
    • Physical Therapy Korea
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    • v.12 no.4
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    • pp.7-11
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    • 2005
  • The purposes of this study were to investigate the effects of variability of training on the acquisition of motor skill of closed loop type tracking task using Rotary Pursuit, and to determine if there was a bilateral transfer effect to the non-dominant hand following practice with the dominant hand. Twelve healthy volunteer students (5 males and 7 females, aged 25 to 37) were randomly divided into a constant practice group and a variable practice group. A photoelectric rotary pursuit apparatus with stop clock and repeat cycle timer by Lafayette Instrumentation Co. was used for this study. Rotary pursuit is a closed loop task in which a subject attempts to keep a photoelectric stylus on a lighted target in motion. Subjects performed the clockwise circular pursuit task while standing. Experimental procedure was divided into three sessions, namely, pre-test, training, and post-test. The constant group practiced all 60 trials at 30 rpm. Variable practice group did a varied practice session with 15 trials at speeds of 20 rpm, 26 rpm, 34 rpm, and 46 rpm. No one in either group practiced with their non-dominant arm. A Mann-Whitney test and a Wilcoxon Signed Ranks test were used for statistical analyses. The results of this study showed no different training effect between groups on the post-test with the dominant hand. However, bilateral transfer effect of rotary pursuit task between hands was demonstrated. Possible mechanisms are discussed.

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Design and Analysis of a L shape two touch point ultrasonic rotary motor (L형 2타점 회전모터의 설계와 해석)

  • Kim, Sung-Hyun;Kim, Hang-Sik;Park, Tae-Gone
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1649-1651
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    • 2004
  • The piezoelectric ceramic is attached between 'L' type guide and 'L' type stator. This motor has rotary motion which is operated by the travelling wave. The basic structure of the two kinds of type motor that called one stator motor, two stator motor is same but we suggested a few parameters for considering their stator design and characteristics. As a result, the two stator type motor is much more useful than one stator type motor for bi-direction rotation.

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Design and Analysis of a L shape two touch point ultrasonic rotary motor (L형 2타점 회전모터의 설계와 해석)

  • Kim, Sung-Hyun;Park, Tae-Gone
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.85-88
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    • 2004
  • The piezoelectric ceramic is attached between 'L' type guide and 'L' type stator, This motor has rotary motion which is operated by longitudinal and bending mode. The basic structure of the two kinds of type motor that called one stator motor, two stator motor is same but we suggested a few parameters for considering their stator design and characteristics. As a result, the two stator type motor is much more useful than one stator type motor for hi-direction rotation.

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Distribution Characteristics of Airborne Bacteria in Organic-Waste Resource Facilities (유기성 폐기물 자원화 시설에서 발생되는 부유 세균의 분포 특성)

  • Kim, Ki-Youn;Ko, Han-Jong;Kim, Dae-Keun
    • Journal of Environmental Health Sciences
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    • v.38 no.2
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    • pp.151-158
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    • 2012
  • Objectives: Bioaerosols released by treating organic-waste resources cause a variety of environmental and hygiene problems. The objective of this study was to investigate the distribution characteristics of the airborne bacteria emitted from a pig manure composting plant, a principal site for organic-waste resource facilities. Methods: Three types of pig manure composting plant were selected based on fermentation mode: screw type, rotary type and natural-dry type. Each site was visited and investigated on a monthly basis between September 2009 and August 2010. A total of 36 air samplings were obtained from the pig manure composting plants. The air sampling equipment was a six-stage cascade impactor. Quantification and qualification of airborne bacteria in the air samples was performed by agar culture method and identification technique, respectively. Results: The mean concentrations of airborne bacteria in pig manure composting plant were 7,032 (${\pm}1,496$) CFU $m^{-3}$ for screw type, 3,309 (${\pm}1,320$) CFU $m^{-3}$ for rotary type, and 5,580 (${\pm}1,106$) CFU $m^{-3}$ for natural dry type. The screw type pig manure composting plant showed the highest concentration of airborne bacteria, followed by the natural dry type and the rotary type. The ratio of respirable to total airborne bacteria was approximately 40-60%. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp. and Escherichia spp. Conclusion: Monthly levels of airborne bacteria were highest in August and lowest in November regardless of fermentation mode. There was no significant correlation relationship between airborne bacteria and environmental factors such as temperature, relative humidity and particulate matters in pig manure composting plants.

The Effect of Feeding Characteristics on the Temperature Distribution of Rotary Kiln (로타리 킬른의 장입 특성이 온도분포에 미치는 영향)

  • Park, Jong-Seok;Chun, Chul-Kyun
    • Journal of the Korean Society of Combustion
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    • v.12 no.3
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    • pp.24-32
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    • 2007
  • A theoretical model was developed for rotary kiln and computational study was conducted to find the effect of feeding characteristics. One dimensional model with the variations of heating distribution, length of heating zone, excess air ratio and revolution was considered. The comparison of parallel-flow rotary kiln with that of counter-flow was conducted. For parallel-flow type, it is found that the variation of temperature of solid is not great for the zone that is following flame-heating zone. This zone is good to take the special treatment because thermal deviation is small and contacting time is enough for another treatment. Increase of excess air ratio have the effect of decreasing solid temperature. But this effect of decreasing solid temperature goes small for the great excess air ratio. The heating is efficient for the flame which has the maximum heating at the central region of the full length.

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An Error Motion Analysis of Rotary Stage Driven By PZT (PZT로 구동되는 회전 스테이지의 오차 운동 분석)

  • Kim, Jin-Ho;Shin, Dong-Ik;Yun, Deok-Won;Han, Chang-Soo;Lee, Sang-Moo;Nam, Kyung-Tae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.1
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    • pp.132-136
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    • 2008
  • Axis of rotation error on rotary system are significant; such as the spindle radial error motion of a aligner, wire bonder and inspector machine which results in the poor state of manufactured goods. In this paper, the simple stage which consists of one PZT actuator and rotary encoder, is analyzed and measured by high resolution capacitance type displacement sensor. As the result of experiment, the paper discusses several issues that must be considered when designing rotary stage driven by PZT.

Friction Characteristics Between Vane and Rolling Piston in a Rotary Compressor Used for Refrigeration and Air-Conditioning Systems

  • Cho, Ihn-Sung;Baek, Il-Hyun;Oh, Seok-Hyung;Jung, Jae-Youn
    • KSTLE International Journal
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    • v.9 no.1_2
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    • pp.17-21
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    • 2008
  • The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present study is one of studies to maximize the advantages of refrigerant compressors. In addition, because friction characteristics of the critical sliding component is essential in the design of refrigerant compressors, the present study also analyzed the lubrication characteristics of a rotary compressor used for refrigeration and air-conditioning systems. In order to measure the friction force between the vane and the rolling piston, an experimental apparatus known as the Pin-on-Disk was used. Load is applied by the hydraulic servo valve controlling the pressure of the hydraulic cylinder. The results showed that the rotational speed of the shaft, the operating temperature, and the discharge pressure significantly influenced the friction force between the vane and the rolling piston.

Design of rotary actuator for CF II type ODD (CF II 카드 규격의 광디스크 드라이브를 위한 로터리 엑추에이터 설계)

  • Kim Sa-Ung;Oh Jeseung;Lee Dong-Ju;Hong Hyuksoo;Park No-Cheol;Yoo Jeonghoon;Park Young-Pil
    • 정보저장시스템학회:학술대회논문집
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    • 2005.10a
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    • pp.64-68
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    • 2005
  • This paper proposes the rotary actuator to apply the designed actuator to the drive of the CF II size. New focus magnetic circuit is considered at this research. The rotary actuator including this circuit is designed to have the dynamic characteristic satisfying the mechanical specification as well as the portable devices. Finally, the adaptability to the portable devices was demonstrated by the finite element analysis and optimization of structural part.

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Effect of the Heat Transfer on the Performance Characteristics of Rolling Piston Type Rotary Compressors for Air Conditioner (회전 피스톤형 로터리 압축기 내의 열전달이 성능특성에 미치는 영향에 관한 연구)

  • 양동준;정진택;박진무;황선웅
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.8
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    • pp.763-770
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    • 2001
  • The high pressure side rotary compressor is investigated in this study. The temperatures at 29 points of main components and the refrigerant and the performance of the instrumented compressor are measured at various operating conditions. The complex heat transfer mechanism between the components, such s cylinder, suction pipe and stator of motor, is fairly clarified. It is also confirmed that the achievement of a high efficiency by reducing the heat transfer loss in the rotary compressor is possible.

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Development of a Web-based Vibration Analysis System for a Rotary Compressor (웹기반 회전식 압축기 진동해석 시스템 개발)

  • 한형석
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.3
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    • pp.175-183
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    • 2003
  • This paper introduces a Web-based vibration analysis system for rotary-type refrigerator compressors. Concern for vibration reduction in compressors has been growing for many years. What is important in vibration reduction is to easily predict the vibration without using a physical compressor. The dynamic model of the compressor is represented as a multi-body dynamic system. Solving the dynamic model is run on a high-performance server. The interfaces of the system are accessible via Web browsers, such as Netscape or Explorer. Anyone who wants to analyze the vibration of the rotary compressor or share the results data can access the system over the Internet regardless of their OS, platform, or location.