• 제목/요약/키워드: rotary function

검색결과 103건 처리시간 0.019초

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

  • 이의윤;김봉준;이정배;성춘모;이운섭;이종수
    • 대한기계학회논문집A
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    • 제35권7호
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    • pp.759-766
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    • 2011
  • 최근 가정용 에어컨은 냉방효율뿐 아니라 소음에 대한 중요성이 지속적으로 높아지고 있다. 로터리 압축기는 에어컨의 소음 중 매우 높은 영향도를 가지고 있으며, 압축기의 소음을 줄이기 위해 머플러 및 공명기에 관한 많은 연구들이 진행되어 왔다. 압축기의 부품 중 어큐뮬레이터는 큰 용적으로 인해 공명에 의한 추가 소음을 에어컨에 전달하는 소음 전달경로가 되며, 어큐뮬레이터의 내부구조는 소음저감을 위해 중요한 설계요소가 되나 지금까지는 연구결과가 미비한 수준이었다. 본 논문에서는 어큐뮬레이터의 소음 저감을 위해 목표주파수 대역에서의 투과손실이 최대가 되는 설계최적화를 수행하였다. 높은 비선형성을 가진 문제의 최적화를 위해 실험계획법과 반경기저신경망기법을 이용한 근사 모델을 사용하였으며, 유전알고리즘을 사용한 최적화를 수행하였다.

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

  • 김경아;전성민;권수미;이광원;유미경
    • 구강회복응용과학지
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    • 제23권4호
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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)

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

  • 이강용;이종명;김준섭
    • 비파괴검사학회지
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    • 제15권4호
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    • pp.520-530
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    • 1996
  • 본 연구에서는 음향방출법을 이용하여 로터리 압축기의 인공 결함을 분류하기 위한 연구를 수행하였다. 이를 위해 프로그램을 개발하였고 선형 분류기, 경험적 Bayesian 분류기, 신경 회로망 분류기를 함께 사용하여 비교하였다. 그 결과 신경 회로망 분류기가 인식률 면에서 유리하였으며 신경 회로망 분류기의 경우 99%이상의 인식률을 얻을 수 있었다.

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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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    • 제61권6호
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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 ($\bar{n}$).

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

  • 이민도;최상민
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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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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초저전력 마이크로 서보시스템의 모델식별을 위한 계측 파라미터 선정 기법 (Sensing Parameter Selection Strategy for Ultra-low-power Micro-servosystem Identification)

  • 한봉수
    • 제어로봇시스템학회논문지
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    • 제20권8호
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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.

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

  • 김동수;김용채;김형의
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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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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회전 외팔보의 진동 및 응력 특성을 고려한 형상 최적화 (Shape Optimization of a Rotating Cantilever Beam Considering Its Modal and Stress Characteristics)

  • 윤영훈;유홍희
    • 대한기계학회논문집A
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    • 제25권4호
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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.

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

  • 모진용;이진교;박득용;김진섭
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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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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진동 특성을 고려한 회전 외팔보 형상의 최적화 (Shape Optimization of a Rotating Cantilever Beam Considering Its Modal Characteristics)

  • 윤영훈;유홍희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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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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