• Tribology and Lubricants
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• v.14 no.3
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• pp.94-99
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• 1998

Generally not only the radial load but also the moment may be applied to the ball bearings for a shaft system. However it has been difficult to determine the static equivalent load because there is the radial static equivalent equation only for the axial and radial force on the bearings. In this paper, the same static equivalent radial load which makes the maximum contact force at the interface between the ball and groove as the applied radial force and moment generate is calculated under the condition that the radial force and the moment are applied to the bearings simultaneously. The relation between the static equivalent load and applied force is studied. Therefore the simple and effective equation for the static equivalent radial load of the radial load and moment is proposed for the deep groove ball bearings.

• Transactions of Materials Processing
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• v.6 no.6
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• pp.482-488
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• 1997

New carbon equivalent equation for the better prediction for the better prediction of roll force in a continuous hot strip mill has been formulated by applying a neural network method. In predicting roll force of steel strip, carbon equivalent equation which normalize the effects of various alloying elements by a carbon equivalent content is very critical for the accurate prediction of roll force. To overcome the complex relationships between alloying elements and operational variables such as temperature, strain, strain rate and so forth, a neural network method which is effective for multi-variable analysis was adopted in the present work as a tool to determine a proper carbon equivalent equation. The application of newly formulated carbon equivalent equation has increased prediction accuracy of roll force significantly and the effectiveness of neural network method is well confirmed in this study.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2262-2267
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• 2017

A new force expression on dielectrics subjected to electric field is proposed in this paper. It is the electric version of the equivalent magnetizing current method in magnetic field. From the idea of electromagnetic duality, virtual equivalent electrifying magnetic current method is conjectured in the field of dielectric force problem. Numerical results show that the proposed method has good agreements with the conventional methods. The merits and demerits of the proposed method are also discussed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.73-78
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• 1990

In current practice of earthquake resistant design the equivalent lateral force procedure is widely used for its simplicity and convenience. But the equivalent lateral force procedure is derived based on the assumption that the dynamic behavior of the structure is governed primarily by the fundamental vibration mode. Therefore proper prediction of dynamic responses of the structure is unreliable using the equivalent lateral force procedure when the effect of higher vibration modes on the dynamic behavior is negligible. In this study design seismic load which can reflect the effect of higher vibration modes is proposed from the point of view of proper assessment of story shears which have the major influence on the design moment of beams and columns. To evaluate the effect of higher modes, differences between the story force based on the equivalent lateral force procedure specified in current earthquake resistance building code and the one based on modal analysis using design spectrum are examined. From these results improved design seismic load for the equivalent lateral force procedure which can reflect the effect of higher vibration modes is proposed.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.96-98
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• 2001

In this paper, the equivalent magnetic circuit and FEM are used to calculate force density of linear BLDC motor. The equivalent magnetic circuit is hard to exact compose for analysis model and it is just applied to linear system. To flexible design and reducing the calculated and analyzed time, magnetic circuit has to be used for designing the linear BLDC motor and deducing equation of force density. Force density as parameter of permanent magnet and coil-side width that are important to determined force density can be estimated using equation of force density. FEM is used to prove reliability of equation of force density and to consider the nonlinear system. Equivalent magnetic circuit and result of FEM are similar, but it is little different by friction loss at the experiment.

• Wind and Structures
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• v.19 no.5
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• pp.565-583
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• 2014

Using synchronous surface pressures from the wind tunnel test, the three dimensional wind load models of high-rise buildings are established. Furthermore, the internal force responses of symmetric high-rise buildings in along-wind, across-wind and torsional directions are evaluated based on mode acceleration method, which expresses the restoring force as the summation of quasi-static force and inertia force components. Accordingly the calculation methods of equivalent static wind loads, in which the contributions of the higher modes can be considered, of symmetric high-rise buildings in along-wind, across-wind and torsional directions are deduced based on internal forces equivalence. Finally the equivalent static wind loads of an actual symmetric high-rise building are obtained by this method, and compared with the along-wind equivalent static wind loads obtained by China National Standard.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.157-162
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• 2000

The ball bearings are the widely-used machine elements in many machineries. They support not only the radial and the axial force but also the moment in many cases. To simply determine the limit load which can be maintained on an ball bearing or survived in wanted life, the combined the radial and axial force with the moment is converted to the equivalent radial or axial load. However, it is not easy to calculate the equivalent load on the ball bearings. So the simplified equations to evaluate the dynamic and static equivalent load considering the axial force and moment are proposed in this analysis. And the modified equation for the static equivalent radial load with the moment and the axial load is proposed. It is desired that these equations are effectively refered in designing the machineries where the ball bearings are installed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.4
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• pp.339-346
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• 2012

In this paper, equivalent models for active control devices are proposed so that building structures with such devices are analyzed using commercial structural analysis programs for the assessment of the structural members under active vibration control. Equivalent link models represent active control device with a virtual linear spring and dashpot, and equivalent force models are control force history acting at the installation point in structural models. Active controllers are designed based on the reduced-order models for a vertical cantilever model and a high-rise building model and corresponding equivalent models are determined from control gain matrices. Based on acceleration, displacement and member force responses, the effectiveness of the equivalent models is verified. As a result, proposed equivalent models, of which equivalent link model showed better performance, appear to enable detailed investigation of structural behavior to the extent of member force level.

• Journal of the Korean Magnetics Society
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• v.21 no.5
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• pp.174-179
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• 2011

Magnetic force calculation methods such as Maxwell stress, virtual work principle, equivalent magnetic charge, and equivalent magnetizing current are widely used until now. The force density is still controversial issue even though it is common sense that all of these methods have legitimate results. The surface force densities of each method are quite different with each other in the point of numerical result and final expression. In this paper, it is shown that a unified expression of body force density is derived using virtual air-gap scheme for an analytic model in which cylindrical magnetic material with a vertical current runs through its center.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.19-30
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• 2019

Recent research on the behavior of silty sand tends to advocate the use of equivalent skeleton void ratio to characterize the density state of this type of soil. This paper presents an investigation to explore the physical meaning of the equivalent skeleton void ratio by means of DEM simulations for assemblies of coarse and fine particles under biaxial shear. The simulations reveal that the distribution pattern of fine particles in the soil skeleton plays a crucial role in the overall macroscopic response: The contractive response observed at the macro scale is mainly caused by the movement of fine particles out of the force chains whereas the dilative response is mainly associated with the migration of fine particles into the force chains. In an assembly of coarse and fine particles, neither all of the fine particles nor all of the coarse ones participate in the force chains to carry the external loads, and therefore a more reasonable definition for equivalent skeleton void ratio is put forward in which a new parameter d is introduced to take into account the fraction of coarse particles absent from the force chains.