• Title/Summary/Keyword: experimental work

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가상협동공간에서의 Haptic Display (Haptic Display in the Virtual Cooperative Workspace)

  • 류성모;최혁렬
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.284-289
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    • 1995
  • This paper presents a haptic display of a cooperative work between the networked multiple users. Excluding the possibility of large timedelay among the users, it is presented the way of configuring individual haptic display systems including the computation of interaction forces, joint driving forces of haptic devices and simulation of the virtual objects. A haptic display system is developed consisting of two haptic display devices operated by two remote users and experimental results to show the validity of the proposed method are also presented.

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EXPERIMENTAL RESULTS OF W-CYCLE MULTIGRID FOR PLANAR LINEAR ELASTICITY

  • Yoo, Jae-Chil
    • East Asian mathematical journal
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    • 제14권2호
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    • pp.399-410
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    • 1998
  • In [3], Franca and Stenberg developed several Galerkin least squares methods for the solution of the problem of linear elasticity. That work concerned itself only with the error estimates of the method. It did not address the related problem of finding effective methods for the solution of the associated-linear systems. In this work, we present computational experiments of W-cycle multigrid method. Computational experiments show that the convergence is uniform as the parameter, $\nu$, goes to 1/2.

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작업의 질을 향상시키는 인간인자에 관한 실증적 연구 (An empirical study of the factors that upgrade job quality)

  • 이순요
    • 대한인간공학회지
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    • 제1권2호
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    • pp.25-29
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    • 1982
  • The job design was frequently tried in many enterprises in order to give workers the job satisfaction, but there remains obscure about what kinds of human factors in job yield the satisfaction. This study is concerned with an experimental method for job design to account for such findings that work with conveyor gave workers unsatisfaction, and that enlarged job of work resulted in high job satisfaction.

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Flow Analysis within a Small Reverse Flow Cyclone

  • R. B Xiang;Lee, K. W.
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2003년도 춘계학술대회 논문집
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    • pp.277-278
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    • 2003
  • Cyclone separators are widely used for cleaning gas streams or for catalyst recovery. For many years, the complexity of the gas flow pattern in cyclones has been a matter of many experimental and theoretical work. At present, precise flow measurements have been performed by means of LDA and hot-wire anemometry (Patterson and Munz, 1996; Hoekstra et al., 1999; Peng et al., 2002). In the theoretical work, Computational fluid dynamics (CFD) codes are frequently employed for simulating cyclone gas-particle flows(Hoekstra et al., 1999). (omitted)

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On the accuracy of estimation of rigid body inertia properties from modal testing results

  • Ashory, M.R.;Malekjafarian, A.;Harandi, P.
    • Structural Engineering and Mechanics
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    • 제35권1호
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    • pp.53-65
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    • 2010
  • The rigid body inertia properties of a structure including the mass, the center of gravity location, the mass moments and principal axes of inertia are required for structural dynamic analysis, modeling of mechanical systems, design of mechanisms and optimization. The analytical approaches such as solid or finite element modeling can not be used efficiently for estimating the rigid body inertia properties of complex structures. Several experimental approaches have been developed to determine the rigid body inertia properties of a structure via Frequency Response Functions (FRFs). In the present work two experimental methods are used to estimate the rigid body inertia properties of a frame. The first approach consists of using the amount of mass as input to estimate the other inertia properties of frame. In the second approach, the property of orthogonality of modes is used to derive the inertia properties of a frame. The accuracy of the estimated parameters is evaluated through the comparison of the experimental results with those of the theoretical Solid Work model of frame. Moreover, a thorough discussion about the effect of accuracy of measured FRFs on the estimation of inertia properties is presented.

A Theoretical and Experimental Study of the Steam Condensation Effect on the CCFL in Nearly Horizontal Two- phase Flow

  • Chun, Moon-Hyun;Yu, Seon-Oh
    • Nuclear Engineering and Technology
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    • 제31권6호
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    • pp.618-630
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    • 1999
  • An analytical model that includes the steam condensation effect has been derived and a parametric study has been performed. In addition, a series of experiments were performed and a total of 34 experimental data for the onset of CCFL in nearly horizontal countercurrent two-phase How have been obtained for various flow rates of water. Comparisons of the present CCFL data with slug formation models show that the agreement between the present as well as the existing model and the data is about the same. However, the deviation between the Taitel and Dukler's model predictions and the data is the largest when if j$_{f}$<0.04 m/s. A parametric study of the effect of the steam condensation using the present model shows that, when all local conditions are similar, the model predicted local gas velocities that cause the onset of flooding are slightly lower when condensation occurred. Based on the visual observation and the evaluation of the present work, it has been concluded that the criterion derived for the onset of slug flow can be directly used to predict the onset of inner flooding in nearly horizontal two-phase flow within the experimental ranges of the present work.

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Analysis of Sensing Mechanisms in a Gold-Decorated SWNT Network DNA Biosensor

  • Ahn, Jinhong;Kim, Seok Hyang;Lim, Jaeheung;Ko, Jung Woo;Park, Chan Hyeong;Park, Young June
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권2호
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    • pp.153-162
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    • 2014
  • We show that carbon nanotube sensors with gold particles on the single-walled carbon nanotube (SWNT) network operate as Schottky barrier transistors, in which transistor action occurs primarily by varying the resistance of Au-SWNT junction rather than the channel conductance modulation. Transistor characteristics are calculated for the statistically simplified geometries, and the sensing mechanisms are analyzed by comparing the simulation results of the MOSFET model and Schottky junction model with the experimental data. We demonstrated that the semiconductor MOSFET effect cannot explain the experimental phenomena such as the very low limit of detection (LOD) and the logarithmic dependence of sensitivity to the DNA concentration. By building an asymmetric concentric-electrode model which consists of serially-connected segments of CNTFETs and Schottky diodes, we found that for a proper explanation of the experimental data, the work function shifts should be ~ 0.1 eV for 100 pM DNA concentration and ~ 0.4 eV for $100{\mu}M$.

CFD-based Design and Analysis of the Ventilation of an Electric Generator Model, Validated with Experiments

  • Jamshidi, Hamed;Nilsson, Hakan;Chernoray, Valery
    • International Journal of Fluid Machinery and Systems
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    • 제8권2호
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    • pp.113-123
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    • 2015
  • The efficiency of the ventilation system is a key point for durable and reliable electric generators. The design of such system requires a detailed understanding of the air flow in the generator. Computational fluid dynamics (CFD) has the potential to resolve the lack of information in this field. The present work analyses the air flow inside a generator model. The model is designed using a CFD-based approach, and manufactured by taking into consideration the experimental and numerical requirements and limitations. The emphasis is on the possibility to accurately predict and experimentally measure the flow distribution inside the stator channels. A major part of the work is focused on the design of an intake and a fan that gives an evenly distributed flow with a high flow rate. The intake also serves as an accurate flowmeter. Experimental results are presented, of the total volume flow rate, the total pressure and velocity distributions. Steady-state CFD simulations are performed using the FOAM-extend CFD toolbox. The simulations are based on the multiple rotating reference frames method. The results from the frozen rotor and mixing plane rotor-stator coupling approaches are compared. It is shown that the fan design provides a sufficient flow rate for the stator channels, which is not the case without the fan or with a previous fan design. The detailed experimental and numerical results show an excellent agreement, proving that the results reliable.

An experimental and numerical approach in strength prediction of reclaimed rubber concrete

  • Williams, Kanmalai C.;Partheeban, P.
    • Advances in concrete construction
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    • 제6권1호
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    • pp.87-102
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    • 2018
  • Utilization of waste tires may be considered as one of the solution to the problems faced by the local authorities in disposing them. Reclaimed rubber (RR) is being used in concrete for replacing conventional aggregates. This research work is focused on the strength prediction of reclaimed rubber concrete using a Genetic Algorithm (GA) for M40 grade of concrete and comparing it with experimental results. 1000 sets were taken and 100 iterations were run during training of GA models. A base study has been carried out in this research work partially replacing cement with three types of fillers such as Plaster of Paris (POP), Fly Ash (FA) and Silica Fume (SF). A total of 243 cubes were cast and tested for compression using a Universal Testing Machine. It was found that SF produced maximum strength in concrete and was used in the main study with reclaimed rubber. Tests were conducted on 81 cube samples with a combination of optimum SF percent and various proportions of RR replacing coarse aggregates in concrete mix. Compressive strength tests of concrete at 7, 14 and 28 days reveal that the maximum strength is obtained at 12 percent replacement of cement and 9 percent replacement of coarse aggregates respectively. Moreover the GA results were found to be in line with the experimental results obtained.