• The Journal of the Acoustical Society of Korea
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• v.16 no.3E
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• pp.7-13
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• 1997

This paper addresses traffic prediction issues on MPEG. A new adaptive traffic prediction scheme is proposed using MPEG picture characteristic that picture traffic depends on the coding mode of that picture, that is, I, P, and B mode. Our prediction scheme, which is based n picture decomposition (PD) and the cross-correlation of the different types of pictures, has better performance in predicting bursty MPEG traffic than that of the first-order autoregressive (AR) prediction scheme. Our simulation results show that the performance is further improved about 15% by utilizing the cross-correlations between pictures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8654-8664
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• 2015

Beam-type structures with non-uniform cross sections are widely used in mechanical, architectural, and civil engineering fields. This paper deals with dynamic characteristics and vibration problems. Governing equations are first derived by using local coordinates. Their solutions are then assumed by using Galerkin's mode summation method. Bisection method is also applied in solving the determinant of the matrix which can provide natural frequencies. Whereas finite element methods adopt admissible functions satisfying only geometric boundary condition, in this study we apply Galerkin's mode summation method which uses eigen-functions satisfying both governing equations and boundary conditions. Modal analysis and experimental tests are finally performed using simply-supported beams with four different non-uniform cross-sections. Our analytical results then show good agreement with experimental ones.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.457-464
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• 2006

Fiber-reinforced composite materials due to their high specific strength, high stiffness and light weight are becoming increasingly used in many engineering industry, especially in the aerospace, marin and civil, etc. In this paper, the buckling load and mode shapes of composite laminates with elliptical cross-section including transverse shear deformations are analyzed. For solving this problems, a versatile flat shell element has been developed by combining a membrane element with drilling degree-of-freedom and a plate bending element. Also, an improved shell element has been established by the combined use of the addition of enhanced assumed strain and the substitute shear strain fields. The combined influence of shell geometry and elliptical cross-sectional parameter, fiber angle, and lay-up on the buckling loads of elliptical cylinder is examined. The critical buckling loads and mode shapes analyzed here may serve as a benchmark for future investigations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.9-15
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• 2011

In this paper, we designed and fabricated a dual-band bandpass filter which can control upper and lower bandwidth using the transformed E-shaped dual-mode resonator. The filter is made the coupling between even-mode not to affect odd-mode resonant frequency by the transformed resonator to control upper bandwidth effectively. The cross coupling between input and output feed lines was employed to improve stopband characteristic. The bandpass filter has been designed to indicate the same bandwidth at center frequency 2 GHz and 3 GHz to show to control bandwidth.

• Cross-Cultural Studies
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• v.26
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• pp.201-226
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• 2012

This essay exams the issues of aesthetic elements that come up when Korean novels get translated into Chinese language. The short story collection titled "An old well" written by Jeong Heui Oh in both languages are compared and analyzed by focusing on the mode of narrations. There are various narrative modes in "An old well". Each narrative mode properly functions for aesthetic effects and drawing meanings. In short, we can find a way to grasp its leitmotif the writer wants to indicate only when we carefully interpret the narrative modes in the original text. However, the narrative modes in Korean text have been simplified by changing its modes into direct narrative in Chinese-translated text. Thus the aesthetic effects in the original text have been spoiled and the Chinese text fails to deliver its meaning involved in the original narrative mode. Translation of novel invites consideration on both of its form and content on account of the text's uniqueness. Accordingly, a close examination and study of the original text should be completed beforehand.

• Industrial Engineering and Management Systems
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• v.14 no.3
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• pp.299-311
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• 2015

Nowadays, the distribution centres aim to reduce costs by reducing inventory and timely shipment. Cross docking is a logistics strategy in which products delivered to a distribution centre by inbound trucks are directly unloaded and transferred to outbound trucks with minimum warehouse storage. Moreover, on-time delivery in a distribution network becomes very crucial especially when several distribution centres and customers are involved. Therefore, an efficient truck scheduling is needed to synchronize the delivery throughout the network in order to satisfy all stake-holders. This paper presents a mathematical model of a mixed integer programming for door assignment and truck scheduling in a multiple inbound and outbound doors cross docking problem according to Just-In-Time concept. The objective is to find the schedule of transhipment operations to simultaneously minimize the total earliness and total tardiness of trucks. Then, a multi-objective differential evolution (MODE) is proposed with an encoding scheme and four decoding strategies, called ITSH, ITDD, OTSH and OTDD, to find a Pareto frontier for the multi-door cross docking problems. The performances of MODE are evaluated using 15 generated instances. The numerical experiments demonstrate that the proposed algorithm is capable of finding a set of diverse and high quality non-dominated solutions.

• The Journal of the Acoustical Society of Korea
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• v.41 no.4
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• pp.397-409
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• 2022

A model is developed for the calculation of sea surface generated ambient noise in the range dependent ocean environment. The sources are located in the horizontal plane all around and their depths are at the near-surface. The receiver array is located in the range dependent ocean waveguide. One-way coupled mode method is used to model the acoustic propagation between the sources and receiver in the range dependent waveguide, and the cross spectral density matrix of noise is derived. In simulation, noise intensity, beamforming result and coherence function are calculated from the cross spectral density matrix. These results are compared with those in the range independent environment. The modeling result shows the effect of the vertical directionality and asymmetry characteristics of the horizontal plane.

• Communications for Statistical Applications and Methods
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• v.22 no.2
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• pp.159-172
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• 2015

This paper considers the problem of reconstructing an underlying signal from noisy data. This paper presents a reconstruction method based on synchrosqueezed wavelet transform recently developed for multiscale representation. Synchrosqueezed wavelet transform based on continuous wavelet transform is efficient to estimate the instantaneous frequency of each component that consist of a signal and to reconstruct components. However, an objective selection method for the optimal number of intrinsic mode type functions is required. The proposed method is obtained by coupling the synchrosqueezed wavelet transform with cross-validation scheme. Simulation studies and musical instrument sounds are used to compare the empirical performance of the proposed method with existing methods.

• Analytical Science and Technology
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• v.17 no.1
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• pp.16-22
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• 2004

Inclusion complexes of the p-nitrophenol with ${\beta}$-cyclodextrin (CD), sulfated ${\beta}$-CD, and ${\beta}$-CD polymer cross-linked with epichlorohydrine (EP) were prepared and characterized by Raman spectroscopy. The intensity of vibration peaks of the C-O and C-N at 1284 and $856cm^{-1}$ of the p-nitrophenol in the presence of EP-linked CD polymer was remarkably increased, respectively. The vibration modes at 1284 and $856cm^{-1}$ are assigned to the out-of phase C-C-O stretching mode and the C-N stretching mode, respectively. The vibration peaks at 1284 and $856cm^{-1}$ increased with increasing the content of EP-linked CD polymers, while decreased with increasing the p-nitrophenol content. Furthermore, the vibration mode of the $NO_2$ symmetric stretch at $1344cm^{-1}$ enhanced with increasing the content of p-nitrophenol.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.709-712
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• 2004

A study of the coupled flexural-torsional vibrations of thin-walled beams with monosymmetric cross-section is presented. The governing differential equations for free vibration of such beams are solved numerically to obtain natural frequencies and their corresponding mode shapes. The beam model is based on the Bernoulli-Euler beam theory and the effect of warping is taken into consideration. Numerical results are given for two specific examples of beams with free-free, clamped-free, hinged-hinged, clamped-hinged and clamped-clamped end constraints both including and excluding the effect of warping stiffness. The effect of warping stiffness on the natural frequencies and mode shapes is discussed and it is concluded that substantial error can be incurred if the effect is ignored.