• 제목/요약/키워드: Radial Parameters

검색결과 576건 처리시간 0.031초

레이디얼 볼베어링의 내륜 끼워맞춤에 관한 유한요소해석 (Finite Element Analysis on the Shaft Fitting to Inner Raceway of Radial Ball Bearing)

  • 고병두;이하성
    • Design & Manufacturing
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    • 제6권1호
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    • pp.45-51
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    • 2012
  • The main goal of this paper is to establish an interference tolerance for determining optimal amount of clearance in the shaft-bearing system supported by radial ball bearings. The 2-D frictional contact model was employed for the FE analysis between the shaft and the inner raceway. Several examples were simulated using different material properties for the solid shaft. Efforts were focused on the deformation applied in the radial direction to select suitable bearings. The analysis results showed that the initial axial preload applied on the bearings plays a significant role to reduce bearing fatigue life. The proposed design parameters obtained by numerical simulations can approximately predict a rate of bearing life reduction as a function of shaft diameter ratio. This analysis can also be used to calculate the optimal initial radial clearance in order to obtain a shaft-bearing system design for high accuracy and long life.

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맥파의 인식상의 분류와 주파수 해석 (The Classification and Frequency Analysis in Radial Pulse)

  • 길세기;한성현;권오상;박승환;홍승흥
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1998년도 추계학술대회
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    • pp.263-264
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    • 1998
  • In this paper, we present the result of feature points recognition and classification of radial pulse by the shape of pulse wave. And we analyze radial pulse in frequency domain. The recognition algorithm use the method which runs in parallel with both the data of ECG and differential pulse simultaneously to recognize the feature points. Also fie specified 3-time elements of pulse wave as main parameters for diagnosis and measured them by execution of algorithm, then we classify the shape of radial pulse by existence and position of feature points. lastly we execute frequency analysis on the feature points and get the power spectrum of radial pulse.

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A boundary radial point interpolation method (BRPIM) for 2-D structural analyses

  • Gu, Y.T.;Liu, G.R.
    • Structural Engineering and Mechanics
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    • 제15권5호
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    • pp.535-550
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    • 2003
  • In this paper, a boundary-type meshfree method, the boundary radial point interpolation method (BRPIM), is presented for solving boundary value problems of two-dimensional solid mechanics. In the BRPIM, the boundary of a problem domain is represented by a set of properly scattered nodes. A technique is proposed to construct shape functions using radial functions as basis functions. The shape functions so formulated are proven to possess both delta function property and partitions of unity property. Boundary conditions can be easily implemented as in the conventional Boundary Element Method (BEM). The Boundary Integral Equation (BIE) for 2-D elastostatics is discretized using the radial basis point interpolation. Some important parameters on the performance of the BRPIM are investigated thoroughly. Validity and efficiency of the present BRPIM are demonstrated through a number of numerical examples.

방사형기저함수망을 이용한 표면 비드폭 예측에 관한 연구 (A Study on Prediction for Top Bead Width using Radial Basis Function Network)

  • 손준식;김인주;김일수;김학형
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.170-174
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    • 2004
  • Despite the widespread use in the various manufacturing industries, the full automation of the robotic CO$_2$ welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, productivity, microstructure and weld properties in arc welding processes have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on the specific experimental results. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an Radial basis function network model to predict the weld top-bead width as a function of key process parameters in the robotic CO$_2$ welding. and to compare the developed model and a simple neural network model using two different training algorithms in order to verify performance. of the developed model.

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단강품 기공의 압착성 향상을 위한 레이디얼 단련변수의 영향 (Effect of Radial Parameters in Cogging Process on Void Closure for Large Forged Products)

  • 최호준;최석우;윤덕재;정진호;백동규;최성규;박훈재;임성주
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 춘계학술대회 논문집
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    • pp.67-70
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    • 2008
  • This paper deals with the effect of radial parameters in cogging process such as reduction in height (Rh) and rotational angle ($\theta$) of a billet on a void closure for large forged products. Usually closing and consolidation of internal void defects in a ingot is a vital matter when utilized as large forged products, using a press with limited capacity and the sizes of the ingots becoming larger. Consequently, it is important to develop cogging process for improvement of internal soundness without a void defect and cost reduction by solid forging alone with limited press capacity. For experiments of cogging process, hydraulic press with a capacity of 800 ton was used together with a small manipulator which was made for rotation and overlapping of a billet. Size of a void was categorized into two types; $\emptyset$ 6.0 mm and $\emptyset$ 9.0 mm to investigate the change of closing and consolidation of void defects existed in the large ingot during the cogging process. Also open void and closed void in the ingot were tackled to show the differentiation of closing process of internal voids with respect to void sizes. In this paper systematic configuration for closing process of void defects were expressed based on this experiment results in the cogging process.

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신정격 및 방광정격 자침이 정상 성인의 맥파 변화에 대한 비교 연구 (The Effects of Sa-am Acupuncture on Radial Pulse in Healthy Human Subjects: A Comparative Study on Tonifications of Kidney and Urinary Bladder)

  • 곽규인;강재희;이현
    • Journal of Acupuncture Research
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    • 제32권2호
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    • pp.105-121
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    • 2015
  • Objectives : The purpose of this study is to observe the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse in healthy subjects. Methods : Sixty healthy subjects participated in this study, and were divided into a kidney tonifying acupuncture group(KI group), urinary bladder tonifying acupuncture group(BL group) and control group. Radial pulse was measured by 3 dimensional pulse imaging system(DMP-3000) before, immediately after, 30 minutes after, and 60 minutes after acupuncture at Cun, Guan, and Chi in each time. Results : 1. BL group exhibited significantly reduced T1 / T, T4 / T, T4 / (T-T4), T5 / T and increased(T-T4) / T compared to KI group. 2. BL group showed increase of radial augmentation index / heart rate(RAI / HR) in left Cun, H5, Ad / Ap in left Chi, H1, As / Ap in right Chi compared to KI group. BL group showed decrease of As / Ap, Aw / Ap in left Chi, H1, pulse depth, Ad / Ap in right Chi compared to KI group. 3. KI group showed increase of Aw / Ap, H1, H2, H4, pulse area in right Guan, pulse depth in right Chi compared to BL group. KI group showed decrease of RAI in left Cun, applied pressure, pulse depth in left Guan, Aw / Ap in right Chi compared to BL group. Conclusions : The effects of Sa-am acupuncture with tonifications of kidney and urinary bladder in healthy humans have been observed on various parameters. The parameters analysed in this study can be used to differentiate the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse.

비정격(脾正格) 자침이 정상 성인 맥파(脈波) 변화에 미치는 영향 (The Effects of Sa-Am Spleen-tonifying Acupuncture on Radial Pulse in Healthy Human Subjects)

  • 윤광식;이현
    • Journal of Acupuncture Research
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    • 제30권4호
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    • pp.1-14
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    • 2013
  • Objectives : The purpose of this study is to investigate the effects of Sa-Am spleen-tonifying acupuncture on radial pulse in healthy human subjects. Methods : Forty healthy human subjects participated in this study, divided into acupuncture group and control group. Radial pulse was measured by 3 dimensional pulse imaging system(DMP-3000) before, right after, 30 minutes after and 60 minutes after acupuncture in the acupuncture group. The subjects in the control group didn't received acupuncture but took a rest and then the radial pulse was measured at the same time points as the acupuncture group. The parameters were analyzed by gender, measuring location, and measuring time point. However the time related parameters exceptionally were analyzed without distinction of measuring location. Results : 1. T, variance of period, T2/T, T4/T, (T-T4)/T, T4/(T-T4), and W significantly changed after acupuncture. 2. Pressure, amplitude of H1, amplitude of H2, Amplitude of H4 and pulse energy significantly changed after acupuncture. 3. Pulse area, systolic pulse area and diastolic pulse area significantly changed after acupuncture. 4. Elasticity, AIx and AIx/HR significantly changed after acupuncture. Conclusions : The effect of Sa-Am spleen-tonifying acupuncture in healthy human may be observed on time, amplitude, pulse area and augmentation index. Further studies on the effects of Sa-Am acupuncture using radial pulse are needed.

COLOR GRADIENTS WITHIN GLOBULAR CLUSTERS: RESTRICED NUMERICAL SIMULATION

  • Sohn, Young-Jong;Chun, Mun-Suk
    • Journal of Astronomy and Space Sciences
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    • 제14권1호
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    • pp.1-17
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    • 1997
  • The results of a restricted numerical simulation for the color gradients within globular clusters have been presented. The standard luminosity function of M3 and Salperter's initial mass functions were used to generate model clusters as a fundamental population. Color gradients with the sample clusters for both King and power law cusp models of surface brightness distributions are discussed in the case of using the standard luminosity function. The dependence of color gradients on several parameters for the simulations with Salpter's initial mass functions, such as slope of initial mass functions, cluster ages, metallicities, concentration parameters of King model, and slopes of power law, are also discussed. No significant radial color gradients are shown to the sample clusters which are regenerated by a random number generation technique with various parameters in both of King and power law cusp models of surface brightness distributions. Dynamical mass segregation and stellar evolution of horizontal branch stars and blue stragglers should be included for the general case of model simulations to show the observed radial color gradients within globular clusters.

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Multiobjective Space Search Optimization and Information Granulation in the Design of Fuzzy Radial Basis Function Neural Networks

  • Huang, Wei;Oh, Sung-Kwun;Zhang, Honghao
    • Journal of Electrical Engineering and Technology
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    • 제7권4호
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    • pp.636-645
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    • 2012
  • This study introduces an information granular-based fuzzy radial basis function neural networks (FRBFNN) based on multiobjective optimization and weighted least square (WLS). An improved multiobjective space search algorithm (IMSSA) is proposed to optimize the FRBFNN. In the design of FRBFNN, the premise part of the rules is constructed with the aid of Fuzzy C-Means (FCM) clustering while the consequent part of the fuzzy rules is developed by using four types of polynomials, namely constant, linear, quadratic, and modified quadratic. Information granulation realized with C-Means clustering helps determine the initial values of the apex parameters of the membership function of the fuzzy neural network. To enhance the flexibility of neural network, we use the WLS learning to estimate the coefficients of the polynomials. In comparison with ordinary least square commonly used in the design of fuzzy radial basis function neural networks, WLS could come with a different type of the local model in each rule when dealing with the FRBFNN. Since the performance of the FRBFNN model is directly affected by some parameters such as e.g., the fuzzification coefficient used in the FCM, the number of rules and the orders of the polynomials present in the consequent parts of the rules, we carry out both structural as well as parametric optimization of the network. The proposed IMSSA that aims at the simultaneous minimization of complexity and the maximization of accuracy is exploited here to optimize the parameters of the model. Experimental results illustrate that the proposed neural network leads to better performance in comparison with some existing neurofuzzy models encountered in the literature.

두꺼운 복합재 원통의 잔류응력 측정방법 (Measurement Method of Residual Stresses in Thick Composite Cylinders)

  • 김종운;박동창;이대길
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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    • pp.245-248
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    • 2005
  • During manufacturing thick composite cylinders, large thermal residual stresses are developed and induce catastrophic interlaminar failures. Since the residual stresses are dependent on many process parameters, such as temperature distribution during cure, cure shrinkage, winding tension, and migration of fibers, calculation of the residual stresses is very difficult. Therefore a radial-cut method have been used to measure the residual stresses in the composite cylinders. But the conventional radial-cut method needs to know numerous material properties which are not only troublesome to obtain but also vary with change of fiber arrangement during consolidation. In this paper, a new radial-cut method with cut-cylinder-bending test was proposed and the measured residual stresses were compared with calculated thermal residual stresses. It was found that the new radial-cut method which does not need to know any of material properties gave better estimation of residual stresses regardless of radial variation of material properties. Additionally, interlaminar tensile strength could be obtained by the cut-cylinder-bending test.

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