• Title/Summary/Keyword: exact

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The Bogie Bunting Sensors quality Inspection (고속열차의 대차불안정감지센서 시험에 대한 연구)

  • Cha, Geun-Su;Jeon, Seong-Joon;Shon, Kang-Ho
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.603-612
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    • 2009
  • The bogie hunting sensor detects accelerations of a bogie. It transmits those accelerations using frequency modulated signal to the TCMS(Train Control and Management System) electronics for functional processing. TCMS decide undesirable bogie hunting and high speed instability with frequency modulated signal. The bogie hunting sensor is essential component for safety driving of high speed train. The bogie hunting sensor's quality inspection before sensor is installed on bogie is very important. Therefore it is required equipment for exact inspection of train bogie hunting sensor. This study is about development of Bogie Hunting sensor's inspection equipment that we can improve Bogie Hunting sensor's quality. Accordingly, I suppose that this thesis will be utilized to improve the bogie hunting sensor's quality thru exact inspection.

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A site-specific CFD study of passing ship effects on multiple moored ships

  • Chen, Hamn-Ching;Chen, Chia-Rong;Huang, Erick T.
    • Ocean Systems Engineering
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    • v.9 no.1
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    • pp.43-77
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    • 2019
  • A local-analytic-based Navier-Stokes solver has been employed in conjunction with a compound ocean structure motion analysis program for time-domain simulation of passing ship effects induced by multiple post-Panamax class ships in the exact condition of a real waterway. The exact seabed bathymetry was reproduced to the utmost precision attainable using the NOAA geophysical database for Virginia Beach, NOAA nautical charts for Hampton Roads and Norfolk harbor, and echo sounding data for the navigation channel and waterfront facilities. A parametric study consists of 112 simulation cases with various combinations of ship lanes, ship speeds, ship heading (inbound or outbound), channel depths, drift angles, and passing ship coupling (in head-on or overtaking encounters) were carried out for two waterfront facilities at NAVSTA Norfolk and Craney Island Fuel Terminal. The present paper provides detailed parametric study results at both locations to investigate the site-specific passing ship effects on the motion responses of ships moored at nearby piers.

EXACT SOLUTIONS OF GENERALIZED STOKES' PROBLEMS FOR AN INCOMPRESSIBLE COUPLE STRESS FLUID FLOWS

  • SIDDIQUE, IMRAN;UMBREEN, YOUSRA
    • Journal of applied mathematics & informatics
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    • v.37 no.5_6
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    • pp.507-519
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    • 2019
  • The ground for this paper is to examine the generalized Stokes' first and second issues for an incompressible couple pressure liquid under isothermal conditions. Exact solutions for each problem are acquired by using the Laplace transform (LT) with respect to the time variable t and the sine Fourier transform (FT) with respect to the y-variable. Further, a comparison is given of the obtained results and the results of Devakar and Lyengar [1] and by using the four inverse Laplace transform algorithms (Stehfest's, Tzou's, Talbot, Fourier series) in the space time domain utilizing a numerical methodology. Moreover, velocity profiles are plotted and considered for various occasions and distinctive estimations of couple stress parameters. At the end, the outcomes are exhibited by graphs and in tabular forms.

On exact wave propagation analysis of triclinic material using three-dimensional bi-Helmholtz gradient plate model

  • Karami, Behrouz;Janghorban, Maziar;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.69 no.5
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    • pp.487-497
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    • 2019
  • Rapid advances in the engineering applications can bring further areas to provide the opportunity to manipulate anisotropic structures for direct productivity in design of micro/nano-structures. For the first time, magnetic affected wave characteristics of nanosize plates made of anisotropic material is investigated via the three-dimensional bi-Helmholtz nonlocal strain gradient theory. Three small scale parameters are used to predict the size-dependent behavior of the nanoplates more accurately. After owing governing equations of wave motion, an analytical approach based harmonic series is utilized to fine the wave frequency as well as phase velocity. It is observed that the small scale parameters, magnetic field and wave number have considerable influence on the wave characteristics of anisotropic nanoplates. Due to the lack of any study on the mechanics of three-dimensional bi-Helmholtz gradient plates made of anisotropic materials, it is hoped that the present exact model may be used as a benchmark for future works of such nanostructures.

Energetics of In-plane Motions in Coupled Plate Structures

  • Park, Young-Ho;Park, Chang Hyun
    • Journal of Ocean Engineering and Technology
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    • v.34 no.6
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    • pp.428-435
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    • 2020
  • Energy flow analysis (EFA) has been used to predict the frequency-averaged vibrational responses of built-up structures at high frequencies. In this study, the frequency-averaged exact energetics of the in-plane motions of the plate were derived for the first time by solving coupled partial differential equations. To verify the EFA for the in-plane waves of the plate, numerical analyses were performed on various coupled plate structures. The prediction results of the EFA for coupled plate structures were shown to be accurate approximations of the frequency-averaged exact energetics, which were obtained from classical displacement solutions. The accuracy of the results predicted via the EFA increased with an increase in the modal density, regardless of various structural parameters. Therefore, EFA is an effective technique for predicting the frequency-averaged vibrational responses of built-up structures in the high frequency range.

Frontal Face Generation Algorithm from Multi-view Images Based on Generative Adversarial Network

  • Heo, Young- Jin;Kim, Byung-Gyu;Roy, Partha Pratim
    • Journal of Multimedia Information System
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    • v.8 no.2
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    • pp.85-92
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    • 2021
  • In a face, there is much information of person's identity. Because of this property, various tasks such as expression recognition, identity recognition and deepfake have been actively conducted. Most of them use the exact frontal view of the given face. However, various directions of the face can be observed rather than the exact frontal image in real situation. The profile (side view) lacks information when comparing with the frontal view image. Therefore, if we can generate the frontal face from other directions, we can obtain more information on the given face. In this paper, we propose a combined style model based the conditional generative adversarial network (cGAN) for generating the frontal face from multi-view images that consist of characteristics that not only includes the style around the face (hair and beard) but also detailed areas (eye, nose, and mouth).

Comparison of ab initio Effective Valence Shell Hamiltonian with Semiempirical Theories of Valence: Pairing Theorem

  • Sun, Ho-Sung;Kim, Un-Sik;Kim, Yang
    • Bulletin of the Korean Chemical Society
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    • v.6 no.3
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    • pp.168-170
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    • 1985
  • The pairing properties of electronic structure are investigated from ab initioists' point of view. Numerical results of exact ab initio effective valence shell Hamiltonian are compared with simple semiempirical Hamiltonian calculations. In the oxygen atom case it was found that effective three-electron interaction terms break the similarity between electron-states and hole-states. With the trans-butadiene as an example the pairing theorem was studied. Even for alternant hydrocarbons, the deviation from the pairing was found to be enormous. The pairing theorem, which is usually stated for semiempirical Hamiltonians, is not valid when the exact effective Hamiltonian is considered. The present study indicates that comparisons between the pairing theorem of semiempirical methods and ab initio effective Hamiltonian give important information on the accuracy of semiempirical methods.

Response of angle-ply laminated cylindrical shells with surface-bonded piezoelectric layers

  • Wang, Haojie;Yan, Wei;Li, Chunyang
    • Structural Engineering and Mechanics
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    • v.76 no.5
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    • pp.599-611
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    • 2020
  • A state-space method is developed to investigate the time-dependent behaviors of an angle-ply cylindrical shell in cylindrical bending with surface-bonded piezoelectric layers. Both the interfacial diffusion and sliding are considered to describe the properties of the imperfect interfaces. Particularly, a matrix reduction technique is adopted to establish the transfer relations between the elastic and piezoelectric layers of the laminated shell. Very different from our previous paper, in which an approximate numerical technique, i.e. power series expansion method, is used to deal with the time-dependent problems, the exact solutions are derived in the present analysis based on the piezoelasticity equations without any assumptions. Numerical results are finally obtained and the effects of imperfect interfaces on the electro-mechanical responses of the laminated shell are discussed.

A Study on the Heat Transfer in Radial Fin of Hyperbolic Profile (쌍곡선 단면을 가진 반경휜에서의 열전달에 관한 연구)

  • Kim, Kwang-Soo;Seoh, Jeong-Il
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.11 no.3
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    • pp.9-17
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    • 1982
  • In this paper, temperature distributions in radial fin of hyperbolic profile for steady -state with no heat generation are obtained by one-dimensional analytical method, finite difference method and experiment respectively. Heat flow rate and fin efficiency from the fin model are obtained by analytical method. To compare the exact solutions obtained by theoretical analysis with the results obtained by finite difference method, cylindrical shape is selected. Particularly, equations of finite difference method for cylindrical shape with irregular boundary are rearranged and formulated. Consequently, temperature distributions in radial fin can certify that are similar to exact solutions. From theoretical analysis, the effects according to heat flow rate and fin efficiency are related to variation of parameters which are fin thickness ${\delta}_o$, fin base temperature $T_o$, thermal conductivity K with same basic dimensions and the fleets are studied and compared.

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