• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.719-720
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• 2008

This paper deals with analytical approach for rotor loss prediction of permanent magnet synchronous generator(PMSG). The rotor losses of synchronous generator are induced by the magnets. Since stator of our model is skewed, slotting effect can be negligible for our PM wind turbine generator. In order to calculate eddy current, this paper derives analytical solutions by the magnetic vector potential. Finally this paper compared analytical result with eddy current density obtained from finite element(FE) calculations using phase current harmonics analysis.

• Structural Engineering and Mechanics
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• 제15권4호
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• pp.437-449
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• 2003

The aim of this study is to develop an analytical model of a beam with open cracks and external strengthening which is able to predict its modal scheme components (natural frequencies and mode shapes). The model is valid as far as the excitation level is low enough not to activate non linear effects. The application field of the model are either the prediction of the efficiency of the reinforcement or the non destructive assessment of the structural properties. The degrees of freedom associated to the fault lips must be taken into account in order to introduce the effect of the external strengthening. In a first step, an analytical formulation of a beam with thin notches is proposed according to the references. The model is then extended to incorporate the strengthening consisting in a longitudinal stiffness applied in the vicinity of the cracks. In a second step, the analytical results are compared with these obtained from a finite element simulation.

• 물과 미래
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• 제8권2호
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• pp.93-99
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• 1975

A linear and optimum linear systems have been reviewed in some detail. The procedure of the solution of the Wiener-Hopf equation analytically in time domain is given and the prediction of downstream outflow for given upstream inflow are made. The predicted results are fairly satisfaotory. The intended physical interpretation of the analytical solution could be descriptable but it was found that the evaluation of the parameters of the response function is rather difficult due to complicacy and a great deal of works.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.885-890
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• 2001

For the shear strength prediction of reinforced concrete beams, this paper considered the bending moment effect. Experimental results of the thirty-seven reinforced concrete beams were compared with analytical results by the FA-STM, TATM and TATM considered bending moment effect. While Ratios of test results to analytical results by using the truss models does not considered the bending moment effect decreased as shear span ratio increased, those by using the proposed method considered that were almost constant regardless of the increase of the shear span ratio. Predicted results obtained from proposed method agreed well with the experimental results.

• 대한기계학회논문집A
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• 제33권3호
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• pp.210-217
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• 2009

This paper presents the analytical prediction of stability lobes in milling. The stability lobes are obtained by measuring the frequency response function (FRF) of a machining center at the cutting point of the end mill cutter, identifying cutting constants, and approximating cutting force coefficients. The stability lobes are experimentally verified through cutting tests.

• Ocean and Polar Research
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• 제37권1호
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• pp.1-9
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• 2015

An approach based on the combined use of a 2D shallow water model and analytical 1D long wave run-up theory is proposed which facilitates the forecasting of tsunami run-up heights in a more rapid way, compared with the statistical or empirical run-up ratio method or resorting to complicated coastal inundation models. Its application is advantageous for long-term tsunami predictions based on the modeling of many prognostic tsunami scenarios. The modeling of the Chilean tsunami on February 27, 2010 has been performed, and the estimations of run-up heights are found to be in good agreement with available observations.

• International Journal of Concrete Structures and Materials
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• 제6권1호
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• pp.41-47
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• 2012

Fiber-Reinforced Polymers (FRP) are used to enhance the behavior of structural components in either shear or flexure. The research conducted in this paper was mainly focused on the shear-strengthening of reinforced and prestressed concrete beams using FRP. The main objective of the research was to identify the parameters affecting the shear capacity provided by FRP and evaluate the accuracy of analytical models. A review of prior experimental data showed that the available analytical models used to estimate the added shear capacity of FRP struggle to provide a unified design equation that can predict accurately the shear contribution of externally applied FRP. In this study, the ACI 440.2R-$08^1$ model and the model developed by Triantafillou and Antonopoulos$^2$ were compared with the prior experimental data. Both analytical models failed to provide a satisfactory prediction of the FRP shear capacity. This study provides insights into potential reasons for the unsatisfactory prediction.

• 한국도로학회논문집
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• 제19권4호
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• pp.37-44
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• 2017

PURPOSES : Conductive and convective heat transfer simulations for an asphalt mixture were made by using discrete element method (DEM) and similarity principle. METHODS : In this research, virtual specimens composed of discrete element method particles were generated according to four different predetermined particle size distribution curves. Temperature variations of the four different particles for a given condition were estimated and were compared with measurements and analytical solutions. RESULTS : The virtual specimen with mixed particles and with the smallest particle show very good agreement with laboratory test results and analytical solutions. As particle size decreases, better heat transfer simulation can be performed due to smaller void ratio and more contact points and areas. In addition, by utilizing the similarity principle of thermal properties and corresponding time unit, analytical time can be drastically reduced. CONCLUSIONS : It is concluded that the DEM asphalt mixture specimens with similarity principle could be used to predict the temperature variation for a given condition. It is observed that the void ratio has critical effect on prediction of temperature variation. Comparing the prediction for a 4 mm particle specimen with a mixed particle specimen, it is also concluded that predicting the mixed particle specimen temperature is much more efficient considering the number of particles that are directly associated with computational time in DEM analysis.

• 소성∙가공
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• 제27권4호
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• pp.227-235
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• 2018

The flow stresses have been identified prior to a numerical simulation for predicting a deformation of materials using the experimental or analytical analysis. Recently, the flow stress models considering the temperature effect have been developed to reduce the number of experiments. Artificial neural network can provide a simple procedure for solving a problem from the analytical models. The objective of this paper is the prediction of flow stress on the fiber metal laminate using the artificial neural network. First, the training data were obtained by conducting the uniaxial tensile tests at the various temperature conditions. After, the artificial neural network has been trained by Levenberg-Marquardt method. The numerical results of the trained model were compared with the analytical models predicted at the previous study. It is noted that the artificial neural network can predict flow stress effectively as compared with the previously-proposed analytical models.

• 한국연초학회지
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• 제21권1호
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• pp.95-101
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• 1999

This study was carried out to analyze chemical components in burley tobacco using near infrared spectroscopy(NIRS). Samples were collected in '96 and '97 crop year. Calibration equations were developed by modified partial least square. The standard error performance(SEP) of '96 crop year samples between NIRS and standard laboratory analysis were 0.25% for nicotine, 0.18% for total nitrogen, 0.59% for crude ash, 0.32% for ether extracts, and 0.14% for chlorine, respectively. The analytical results of '97 crop year samples were similar to those of '96 crop year samples. The analytical result of '97 crop year samples analyzed by '96 calibration equation was more inaccurate than that of '96 crop year samples. The SEP of '96 or '97 crop year samples applying calibration equation derived from '96 plus '97 crop year samples was similar to that of '96 or '97 crop year samples analyzed by '96 or '97 calibration equation, respectively. The SEP of '97 crop year samples analyzed by calibration equation derived from '96 plus '97 crop year samples was more accurate than that of '97 crop year samples analyzed by '96 calibration equation. To improve the analytical inaccuracy caused by the difference of crop year between calibration and prediction samples, we need to include the prediction sample spectra which were different from calibration sample spectra in recalibration sample spectra, and then develop recalibration equation. The NIRS can apply to analyze burley leaf tobacco, leaf process or tobacco manufacturing process which were required the rapid analytical result.