• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.203-204
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• 2008

A novel method using scaling down and restoration to reduce the PAPR of OFDM signal is proposed. This method shows a better BER performance than clipping method. And also the throughput efficiency is better than SLM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.998-1012
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• 2013

The article is concerned with a mathematical modeling which can improve performances of PDE-based restoration models. Most PDE-based restoration models tend to lose fine structures due to certain degrees of nonphysical dissipation. Sources of such an undesirable dissipation are analyzed for total variation-based restoration models. Based on the analysis, the so-called equalized net diffusion (END) modeling is suggested in order for PDE-based restoration models to significantly reduce nonphysical dissipation. It has been numerically verified that the END-incorporated models can preserve and recover fine structures satisfactorily, outperforming the basic models for both quality and efficiency. Various numerical examples are shown to demonstrate effectiveness of the END modeling.

• Journal of Multimedia Information System
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• v.1 no.1
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• pp.87-93
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• 2014

The aim of microscopic image restoration is to recover the image by applying the inverse process of degradation, and the results facilitate automated and improved analysis of the image. In this work, we consider the problem of image restoration as a minimization problem of convex cost function, which consists of a least-squares fitting term and regularization terms with non-negative constraints. The finite step method is proposed to solve this constrained convex optimization problem. We demonstrate the convergence of this method. Efficiency and restoration capability of the proposed method were tested and illustrated through numerical experiments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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• pp.53-61
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• 2004

This paper proposes two types of sub-network based on dynamic restoration schemes to improve survivability of GMPLS networks and analyzes characteristics of these two schemes. The first proposed scheme divides with a whole GMPLS network into several sub-networks, applies a mixture of both restoration and protection methods according to fault location. The other scheme divides a whole GMPLS network into primary and secondary sub-networks, applies a restoration method in each sub-network according to fault location. In our simulation, we evaluate the performances of network resource utilization, restoration success rate, and mean restoration time and conduct its comparative analysis with conventional schemes. The simulation results show that the efficiency of network resource utilization in the proposed schemes is increased as compared with conventional restoration schemes (l＋l, 1:1, 1:N) in case of single-failed link. By contrast, we found that the performances of restoration success rate and mean restoration time in case of multi-failed link is lower than conventional restoration schemes. However, the probability that multi-failed link is occurred is very low so that the problem in practical GMPLS network is negligible.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.5
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• pp.1-9
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• 2006

The purpose of this study is to make a design guideline in designing constructed wetland which can treat water quality both of point and nonpoint source water pollution. It focuses on structural aspects of two case studies of constructed wetland applying SSB(Sustainable Structured wetland Biotope) system in Korea. The constructed wetland of Lake Ju-am which was constructed in 2002 by Environmental Management Corporation, was designed by applying SSB system. It shows higher removal efficiency than expected - 56% of BOD removal efficiency, 60% of T-N removal, and 76% of T-P removal efficiency. In two cases, total wetland areal extents were calculated referred to treatment efficiency. The system is consist of micro-cell structures : inflow channel, forebay, multiple wetland cells and micro-pool. When designing constructed wetland appropriate in local area, the total organic system of vertical and horizontal structure : geology, hydrology, land use, and ecological surroundings of the sites should be considered totally.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.603-610
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• 2003

On the optical network, it is important to build restoration scheme capable to network survivability in preparation of potential failure on communication route. This paper analyze the existing schemes on restoration of failure on the optical network, and propose deferred commit scheme to improve resource utilization and management efficiency. Also, the transfer flow of messages needed for transferring restoration signal are presented in a concrete way and delay time required by shared mesh restoration scheme is explained in a substantial way. Simulation-based comparative analysis of various schemes is performed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.49-58
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• 2010

In this paper, we present a methodology for fast segment restoration under multiple simultaneous link failures in mesh-type MPLS networks. The salient feature of the methodology is that both resilience and QoS constraint conditions have been taken into account for fast segment restoration. For fast restoration, a sufficient condition for testing the existence of backup segments with guaranteed-resilience has been derived for a mesh-type MPLS network. The algorithms for constructing backup segments which can meet both resilience and QoS constraint conditions are then presented with illustrating examples. Finally, simulation has been done to show the efficiency of the proposed segment restoration algorithms.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.4-14
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• 2016

Although CAD/CAM technology has been used in dentistry for more than decades, the present CAD/CAM dentistry is still quite inefficient or unesthetic. Zirconia restoration has faced with two contradictory words, 'Efficiency' and 'Esthetics'. One can consider monolithic zirconia restoration to be efficient with CAD/CAM. The monolithic zirconia restoration, however, is rarely esthetic due to the current limitations with zirconia. On the contrary, porcelain build-up is almost indispensible in fabricating esthetic restoration, especially in anterior region. In this article, the current status of monolithic zirconia restoration and clinical cases will be presented.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.1
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• pp.104-113
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• 2001

This article described a procedure for fabricating an esthetic gingival porcelain restoration as an implant-supported fixed prosthesis for edentulous maxilla. Alternative treatments for fully edentulous patients include an implant-supported overdenture or a fixed implant-supported prosthesis with bilateral distal cantilevers. But, from a functional and biomechanical point of view, the fixed implant-supported prosthesis with posterior cantilevers or implant-supported tissue-borne overdenture do not significantly improve masticatory effectiveness compared with a distributed implant restoration as a fixed implant-supported prosthesis. The fact that the prosthesis is supported by distributed implants over eight for edentulous maxilla in general, provides increased masticatory efficiency as a fixed restoration and similar gingival appearance with esthetic gingival porcelain. It is also detachable by dentist to allow easier after-care of soft tissue and the prosthesis.

• Journal of applied mathematics & informatics
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• v.38 no.5_6
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• pp.519-532
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• 2020

In this paper, we first propose a new total variation-based regularization model for image restoration. We next propose a fixed-point-like method for solving the new image restoration model, and then we provide convergence analysis for the fixed-point-like method. To evaluate the feasibility and efficiency of the fixed-point-like method for the new proposed total variation-based regularization model, we provide numerical experiments for several test problems.