• Earthquakes and Structures
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• v.24 no.1
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• pp.65-79
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• 2023

A simplified analytical solution for seismic response of tunnel cross section in horizontally layered ground subjected to oblique incidence of SH wave is deduced in this paper. The proposed analytical solution consists of two main steps: free-field response in layered field and tunnel response. The free field responses of the layered ground are obtained by one-dimensional finite element method in time domain. The tunnel lining is treated as a thick-wall cylinder to calculate the tunnel response, which subject to free field stress. The analytical solutions are verified by comparing with the dynamic numerical results of two-dimensional ground-lining interaction analysis under earthquake in some common situations, which have a good agreement. Then, the appropriate range of the proposed analytical solution is analyzed, considering the height of the layered ground, the wavelength and incident angle of SH wave. Finally, by using the analytical solutions, the effects of the ground material, burial depth of the tunnel, and lining thickness and the slippage effect at the ground-lining interface on the seismic response of tunnels are investigated. The proposed solution could serve as a useful tool for seismic analysis and design of tunnels in layered ground.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.990-1001
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• 2015

This paper presents analysis of Switched Reluctance Machine (SRM) using Geometry Based Analytical Model (GBAM), Finite Element Analysis (FEA) and Fourier Series Model (FSM) with curve fitting technique. Further a Transient Analysis (TA) technique is proposed to corroborate the analysis. The main aim of this paper is to give in depth procedure in developing a Geometry Based Analytical Model of Switched Reluctance Machine which is very accurate and simple. The GBAM is developed for the specifications obtained from the manufacturer and magnetizing characteristic of the material used for the construction. Precise values of the parameters like Magneto Motive Force (MMF), flux linkage, inductance and torque are obtained for various rotor positions taking into account the Fringing Effect (FE). The FEA model is developed using MagNet7.1.1 for the same machine geometry used in GBAM and the results are compared with GBAM. Further another analytical model called Fourier Series Model is developed to justify the accuracy of the results obtained by the methods GBAM and FEA model. A prototype of microcontroller based SRM drive system is constructed for validating the analysis and the results are reported.

• The KSFM Journal of Fluid Machinery
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• v.13 no.5
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• pp.35-42
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• 2010

This paper deals with the development of analytical model of a turbocharger and its detail rotordynamic analysis. Two analytical models, which are verified by experimental modal testing, are proposed and the analytical model including rotor shaft extended to compressor and turbine wheel end side is chosen. A rotordynamic analysis includes the critical map, Campbell diagram, stability, and unbalance response, especially nonlinear transient response considering nonlinear fluid film force at bearings. Although the linearized analysis accurately predicts the critical speeds, stability limit, and stability threshold speed, the predicted vibration results are not valid for speeds above the stability threshold speed since the rotor vibrates with a subsynchronous component much larger than the one synchronous with rotor speed. Hence, for operating speed above the stability threshold, a nonlinear transient analysis considering nonlinear fluid film force must be performed in order to accurately predict vibration responses of rotor and guarantee results of analysis.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.804_805
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• 2009

This paper deals with analysis on electromagnetic characteristics of linear induction motor(LIM) using the analytical method. As a analytical method, space harmonics method which is applied to multilayer region is used in this paper. Using the flux density obtained by analytical method, thrust and normal force are calculated through Maxell stress tensor. The results such as flux densitty, eddy current and force are verified by comparison between analytical results and FEM.

• Korean Journal of Pharmacognosy
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• v.38 no.1
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• pp.19-21
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• 2007

Myristica fragrans has been used for the treatment of stomachache in East Asia. It is very important to determine the amount of myristicin in Myristica fragrans, because excess myristicin causes side effects. In this study, we developed and validated the method for determination contents of myristicin in Myristica fragrans which was purchased from various regions of Korea. The average content of myristicin in Myristica fragrans was 2.10% with the validated HPLC analysis method.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.241-247
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• 2011

This paper is intended to improve efficiency of two-phase BLDC motor using analytical and statistical methods, and then the stability of the starting for the designed model is investigated. The characteristics of the motor according to magnetization directions of permanent magnet are analyzed through the analytical method, and design variables that affect the efficiency are selected. Preliminary optimal design is performed using the analytical method with the design variable. The RSM (Response Surface Method) based on the FEA (Finite Element Analysis) is applied to complement errors of the analytical method. As a result, the optimal design is determined. Finally, the stability of the starting for the optimal designed model is evaluated by analyzing cogging torque, and it is verified through the FEA.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.997-998
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• 2007

This paper deals with analytical solution concerning the image method using the magnetic charge instead of 3D FEA(finite element analysis) in the slotless single air-gap motor. The theory of analytical method and the design procedures are introduced. The reliability and validity of proposed analytical solution are verified through the comparison with the results of commercial 3D FE software. In addition, calculation time between proposed analytical solution and 3D FEA is compared. Finally, characteristics, such as Back-EMF and phase resistance, between calculated and experimental results are compared. From the verification with 3D FEA and experimental results, it is proved that presented analytical method provided very effective and precise results.

• Journal of Power Electronics
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• v.10 no.6
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• pp.680-685
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• 2010

Although LLC resonant converters have the advantages of a wide operation range and high efficiency, the lack of an analytical solution for the peak gain makes it difficult to optimize the resonant tank design, when considering not only the normal condition but also the holdup time requirement. In this paper, based on a mathematical analysis of a LLC resonant converter at the peak gain point, an analytical solution for the peak gain has been developed. By using the developed analytical solution, the peak gain with given resonant tank parameters can be obtained. To confirm the validity of the developed analytical solution, simulations and experimental results are compared.

• Food Science and Industry
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• v.55 no.1
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• pp.45-57
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• 2022

This study was proceeded the analytical methods using various analytical instruments for polycyclic aromatic hydrocarbons (PAHs) in food products. Various analytical methods were developed to determine levels of PAHs including benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and chrysene formed in various food products using gas chromatography-mass spectrometry (GC-MS), enzyme-linked immunosorbent assay (ELISA) and raman spectroscopy. Recently, the rapid on-site response for the detection of hazardous substances in food aims to develop an onsite rapid detection of a simplified technical analysis method to reduce the time and cost required for analysis of PAHs. Current PAHs detection methods have been reviewed along with new raman spectroscopy analytical method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.720-725
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• 2000

This paper persents the characteristic analysis method of slotless-type Permanent Magnet Synchronous Motor using the analytical method. The results of analysis are compered with FEM to verify the validity of the proposed method.