• Title/Summary/Keyword: rotary function

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Design Optimization of an Accumulator for Noise Reduction of Rotary Compressor (공조용 로터리 압축기 소음저감을 위한 어큐뮬레이터 최적설계)

  • Lee, Ui-Yoon;Kim, Bong-Joon;Lee, Jeong-Bae;Sung, Chun-Mo;Lee, Un-Seop;Lee, Jong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.759-766
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    • 2011
  • Recently, noise reduction in room air conditioners has been one of the important issues as well as cooling efficiency. The rotary compressor is the dominant noise source in an air conditioner. A number of studies have been conducted on reducing compressor noise through improving muffler and resonator design. However the noise from the accumulator, a noise delivering path between compressor and air conditioner, is not fully taken into consideration. The accumulator contains a large inner cavity, and usually generates additional resonance noise during operation. This paper aims to conduct an optimal design for reducing accumulator noise by maximizing the transmission loss within the target frequency range that represents high-order nonlinearity. Design of experiments and radial basis function neural network are used in the context of approximate meta-models, and genetic algorithm is used as an optimization tool.

A Study on the Shaping Ability of Three Different Rotary Nickel-Titanium Instruments in Simulated Curved Root Canal (만곡 근관에서 다양한 엔진 구동형 Nickel-Titanium 파일의 근관 성형능력에 대한 연구)

  • Kim, Kyoung-A;Chon, Seong-Min;Kwon, Su-Mi;Lee, Kwang-Won;Yu, Mi-Kyung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.4
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    • pp.293-302
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    • 2007
  • I. Objectives The purpose of this study was to compare the shaping ability between the single length technique performed with Mtwo instruments (VDW, Munich, Germany) and the crown-down technique using K3 (SybronEndo, West Collins, CA, USA) and RaCe (FKG, La Chaux-de-Fonds, Switzerland) instruments. II. Materials & Methods Forty five curved canals in resin blocks were equally divided in to three groups. Group 1 (Mtwo) was instrumented used the full length of canal according to the manufacturer's instructions. The simulated canals was prepared to an instrument size of 35, 0.04 taper canal terminus. In group 2 (Race) and group 3 (K3) was instrumented in a crown-down manner and prepared to an instrument size of 30, 0.06 taper canal terminus. Pre- and post-instrumentation images were scanned and assessment of canal shape was completed with a computer image analysis program. Material removal was measured at 7 measuring points, beginning 1mm from the end point of preparation. Differenced of centering ratio were statistically analyzed using One-way ANOVA followed by Duncan's test. II. Results & Conclusion There was no significant difference on 1, 2, 3 and 7mm measuring point. At 4 and 5 measuring point, significant difference showed between the Mtow instruments and other two instruments. (p<0.05)

Development of Adaptive AE Signal Pattern Recognition Program and Application to Classification of Defects in Metal Contact Regions of Rotating Component (적응형 AE신호 형상 인식 프로그램 개발자 회전체 금속 접촉부 이상 분류에 관한 적용 연구)

  • Lee, K.Y.;Lee, C.M.;Kim, J.S.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.15 no.4
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    • pp.520-530
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    • 1996
  • In this study, the artificial defects in rotary compressor are classified using pattern recognition of acoustic emission signal. For this purpose the computer program is developed. The neural network classifier is compared with the statistical classifier such as the linear discriminant function classifier and empirical Bayesian classifier. It is concluded that the former is better. It is possible to acquire the recognition rate of above 99% by neural network classifier.

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Quadratic B-spline finite element method for a rotating non-uniform Rayleigh beam

  • Panchore, Vijay;Ganguli, Ranjan
    • Structural Engineering and Mechanics
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    • v.61 no.6
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    • pp.765-773
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    • 2017
  • The quadratic B-spline finite element method yields mass and stiffness matrices which are half the size of matrices obtained by the conventional finite element method. We solve the free vibration problem of a rotating Rayleigh beam using the quadratic B-spline finite element method. Rayleigh beam theory includes the rotary inertia effects in addition to the Euler-Bernoulli theory assumptions and presents a good mathematical model for rotating beams. Galerkin's approach is used to obtain the weak form which yields a system of symmetric matrices. Results obtained for the natural frequencies at different rotating speeds show an accurate match with the published results. A comparison with Euler-Bernoulli beam is done to decipher the variations in higher modes of the Rayleigh beam due to the slenderness ratio. The results are obtained for different values of non-uniform parameter ($\bar{n}$).

A Study of Operation Performance Prediction Method for the Gasification Melting Furnace (가스화 용융로의 운전성능 예측기법에 관한 연구)

  • Lee, Min-Do;Choi, Sang-Min
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.43-49
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    • 2005
  • Social interest and request about low pollution waste treatment process are growing and gasification melting method, as a new technology concept, is risen. The necessity of engineering analysis to determine design standards and operation condition is required. In this study, the objective and function of components and operation process of various gasification melting furnaces such as shaft type, fluidized bed and Rotary Kiln type gasification melting furnace are reviewed and the design standard and operation range of gasification melting furnace are determined by inspecting the change of output and operation condition with input condition change.

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Sensing Parameter Selection Strategy for Ultra-low-power Micro-servosystem Identification (초저전력 마이크로 서보시스템의 모델식별을 위한 계측 파라미터 선정 기법)

  • Hahn, Bongsu
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.8
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    • pp.849-853
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    • 2014
  • In micro-scale electromechanical systems, the power to perform accurate position sensing often greatly exceeds the power needed to generate motion. This paper explores the implications of sampling rate and amplifier noise density selection on the performance of a system identification algorithm using a capacitive sensing circuit. Specific performance objectives are to minimize or limit convergence rate and power consumption to identify the dynamics of a rotary micro-stage. A rearrangement of the conventional recursive least-squares identification algorithm is performed to make operating cost an explicit function of sensor design parameters. It is observed that there is a strong dependence of convergence rate and error on the sampling rate, while energy dependence is driven by error that may be tolerated in the final identified parameters.

Seven axis modular type pneumatic manipulator development (7축 모듈라형 공기압 매니퓰레이터 개발)

  • 김동수;김용채;김형의
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.968-973
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    • 1991
  • Seven axis modular type pneumatic manipulator is composed of electro-pneumatic automation system which contributes to factory automation by performing loading & unloading process successively which is simple routine work of dealing item of machine tool, catapult, assembly machine, welding machine and so on. In this study, we obtained soft and quick movement in a large space and good reliability motion of various function by combining several actuators which perform rotation movement as well as linear movement at the same time. Gripper which apply to rotary sensor transmitted a structure to demanded position. This development item of 5kgf load prevent stick-slip phenomena of stroke end by designing high cushion internal. We develope flexible manipulator which conforms to demand of user by applying multiple sequence program.

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Shape Optimization of a Rotating Cantilever Beam Considering Its Modal and Stress Characteristics (회전 외팔보의 진동 및 응력 특성을 고려한 형상 최적화)

  • Yun, Yeong-Hun;Yu, Hong-Hui
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.4
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    • pp.645-653
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    • 2001
  • It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency or the maximum stress of a rotating beam. By changing the thickness of the rotating beam, the modal or the stress characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized for the design of rotating structures such as turbine blades and aircraft rotary wings.

Determination of the Operating Frequency and Pipe Design of Inverter Air-conditioner considering Dynamic Characteristics of Inverter Rotary Compressor (진동 특성 파악을 통한 인버터 에어컨의 운전 주파수 및 파이프 형상 결정)

  • 모진용;이진교;박득용;김진섭
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.203-206
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    • 2001
  • The reduction of chopping noise generated from inverter compressor and the piping design reducing vibration are the most important items in the quality of air conditioner. The chopping noise is identified by the study of the relationship between carrier frequency and natural frequency of the compressor shell. The high carrier frequency is the key factor in reduction of carrier noise. To keep the natural frequencies of the system as far as away from the operating frequencies appears to be the most important factor in the design of piping system.

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Shape Optimization of a Rotating Cantilever Beam Considering Its Modal Characteristics (진동 특성을 고려한 회전 외팔보 형상의 최적화)

  • Yun, Young-Hoon;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.643-648
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    • 2000
  • It is well known that natural frequencies increase when a cantilever beam rotates about the axis perpendicular to its longitudinal axis. Such phenomena that are caused by centrifugal inertia forces are often referred to as the stiffening effects. Occasionally it is necessary to control the variation of a natural frequency of a rotating beam. By changing the thickness of the rotating beam, the modal characteristics can be changed. The thickness of the rotating beam is assumed to be a cubic spline function in the present work. An optimization method is employed to find the optimal thickness shape of the rotating beam. This method can be utilized usefully for the design of rotating structures such as turbine blades and aircraft rotary wings.

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