• MALSORI
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• no.49
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• pp.63-75
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• 2004

Most existing telephone speech transmitted in current public networks is band-limited to 0.3-3.4 kHz. Compared with wideband speech(0-8 kHz), the narrowband speech lacks low-band (0-0.3 kHz) and high-band(3.4-8 kHz) components of sound. As a result, the speech is characterized by the reduced intelligibility and a muffled quality, and degraded speaker identification. Bandwidth extension is a technique to provide wideband speech quality, which means reconstruction of low-band and high-band components without any additional transmitted information. Our new approach considers to exploit harmonic synthesis method for reconstruction of low-band speech over the CELP coded speech. A spectral distortion measurement and listening test are introduced to assess the proposed method, and the improvement of synthesized speech quality was verified.

• Journal of the Korean Arthroscopy Society
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• v.2 no.1
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• pp.4-14
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• 1998

As with anterior cruciate ligament reconstruction, posterior cruciate ligament(PCL) reconstruction requires a good understanding of the anatomy and biomechanical properties of the PCL to place the graft correctly as well as to choose the appropriate structure and material for the graft. The anatomy and function of the PCL can be somewhat confusing and continuing to evolve so far. Recent studies have focused on the insertion site anatomy and the identification of the functional components of the ligament. The issue of the ligament isometry and the role of PCL in knee kinematics are still totally resolved. This article can be provided an update on current concepts of the anatomy and biomechanics of the PCL through literature reviews. A clear understanding of these knowledges enables the clinicians to diagnose injuries to the PCL accurately and to reconstruct these structures successfully.

• ETRI Journal
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• v.25 no.5
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• pp.345-355
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• 2003

In this paper, we propose a method for designing a class of M-channel, causal, stable, perfect reconstruction, infinite impulse response (IIR), and parallel uniform discrete Fourier transform (DFT) filter banks. It is based on a previously proposed structure by Martinez et al. [1] for IIR digital filter design for sampling rate reduction. The proposed filter bank has a modular structure and is therefore very well suited for VLSI implementation. Moreover, the current structure is more efficient in terms of computational complexity than the most general IIR DFT filter bank, and this results in a reduced computational complexity by more than 50% in both the critically sampled and oversampled cases. In the polyphase oversampled DFT filter bank case, we get flexible stop-band attenuation, which is also taken care of in the proposed algorithm.

• Journal of the Korean housing association
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• v.8 no.3
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• pp.231-236
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• 1997

After 1970 Years. Korea has developed a concept of public domestic housing. But this house is reached the uppermost limit time of using the occupant's satisfying life. Then reconstruction of Apartment house is urgently needed which is developed in Korea. So this study is examined the demolition work on current reconstructing apartment site. for reconstruction. Therefore this research examined the fitted demolition time of low-rise house and characteristics of demolition works. The conclusions from this experiment are shown below. 1. The average day work in clutcher method is shown about 1, 032㎥/Day. 2. The calculations of the term of construction which is produced by the analysis of demolition construction period on low-rise house is below. D(day) ＝ S(day) ＋ (0.272＋0.000902b(㎥))＋R(day)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.12
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• pp.943-947
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• 2014

Recently, a new method for reconstructing a forced nonlinear dynamic system has been proposed; specifically, the simultaneous reconstruction of its excitation as well as restoring characteristics of the system. The reconstruction was just theoretically shown to be possible by measuring the system's responses, based on newly introduced notions, a J-function and a zero-crossing time. However, numerically in the current paper, we are to reconstruct a linear system, i.e., we focus on numerical experiments to reconstruct both the excitation and the linear restoring characteristic of a linear forced oscillating system by using response data, based on the J-function and the zero-crossing time.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.3
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• pp.163-172
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• 2003

A stereo matching has been an important tool for the reconstruction of 3D terrain. The current state of stereo matching technology has reached the level where a very elaborate DEM(Digital Elevation Map) can be obtained. However, there still exist many factors causing DEM error in stereo matching. This paper propose a new method to reduce the error caused by the lack of significant features in the correlation window The proposed algorithm keeps the correlation window as small as possible, as long as there is a significant feature in the window. Experimental results indicate that the proposed method increases the DEM accuracy by $72.65\%$ in the plain area and $41.96\%$ in the mountain area over the conventional scheme. Comparisons with Kanade's result show that the proposed method eliminates spike type of errors more efficiently than Kanade's adaptive window technique and produces reliable DEM.

• Current Optics and Photonics
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• v.2 no.4
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• pp.332-339
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• 2018

A new multi-frequency fringe projection method is proposed to reduce the nonlinear phase error in 3-D shape measurements using an adaptive compensation method. The phase error of the traditional fringe projection technique originates from various sources such as lens distortion, the nonlinear imaging system and a nonsinusoidal fringe pattern that can be very difficult to model. Inherent possibility of phase error appearing hinders one from accurate 3-D reconstruction. In this work, an adaptive compensation algorithm is introduced to reduce adaptively the phase error resulting from the fringe projection profilometry. Three different frequencies are used for generating the gratings of projector and conveyed to the four-step phase-shifting procedure to measure the objects of very discontinuous surfaces. The 3-D shape results show that this proposed technique succeeds in reconstructing the 3-D shape of any type of objects.

• Journal of the Korean Vacuum Society
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• v.4 no.4
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• pp.367-372
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• 1995

We investigate the Au(001) surface reconstruction, numerically, by Molecular Dynamics (MD) simulation. We find that the top-most layer of Au(001) surface is reconstructed to a contracted hexagonal face, and relaxed about 0.05$\AA$ upward at room temperature. The contraction ratio with respect to a unreconstructed Au(111) surface is about 3.5%. The hexagonal layer is slightly distorted and buckled. The surface corrugation is found to be about 0.28$\AA$ on average. In our earlier work we have predicted the in-plane orientation of the reconsturcted layer to be either $0^{\circ}$ or $0.7^{\circ}$ depending on the size of the cluster. However, we find only $0.0^{\circ}$ in this simulation because the size of the cluster correspoding to the $0.7^{\circ}$ orientation is larger than the current limitation of MD simulation. These findings are in good agreement with experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.60.4-60
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• 2001

Electrical impedance tomograpy (EIT) determines the resistivity distribution inside an inhomogeneous target by means of voltage and current measurements conducted at the target boundary. In this paper, a genetic algorithm (GA) approach is proposed for the solution of the EIT image reconstruction. Results of numerical experiments of EIT solved by the GA approach are presented and compared to that obtained by the modified Newton-Raphson method. The GA approach is relatively expensive in terms of computing time and resources, and at present this limits the applicability of GA to the field of static imaging. However, the continuous and rapid growth of computing resources makes the development of real-time dynamic imaging applications based on GA´s conceivable in the near future.

• ETRI Journal
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• v.41 no.1
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• pp.61-72
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• 2019

In this paper, we demonstrate the current concepts in holographic tomography (HT) realized within limited angular range with illumination scanning. The presented solutions are based on the work performed at Warsaw University of Technology in Poland and put in context with the state of the art in HT. Along with the theoretical framework for HT, the optimum reconstruction process and data visualization are described in detail. The paper is concluded with the description of hardware configuration and the visualization of tomographic reconstruction, which is calculated using a provided processing path.