• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.432-438
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• 2010

In this paper we study the effect of bit-to-symbol mappings on the convergence behavior of turbo equalizers employing low-density parity-check (LDPC) codes over high order modulations. We analyze the effective SNR of the outputs from linear minimum mean-squared error (MMSE) equalizers and the convergence property of LDPC decoding for different symbol mappings. Numerical results show that the bit-reliability (BR) mapping provides better performance than random mapping in LDPC-coded turbo equalizers over high order modulations. We also verify the effect of symbol mappings through the noise threshold and error performance.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.607-614
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• 2019

It has been an issue among researchers that the tsunamis that occurred on the west coast of Japan in 1983 and 1993 damaged the coastal cities on the east coast of Korea. In order to predict and reduce the damage to the Korean Peninsula effectively, it is necessary to install offshore tsunami observation instruments as part of the system for the early detection of tsunamis. The purpose of this study is to recommend the optimal deployment of tsunami observation instruments in terms of the higher probability of tsunami detection with the minimum equipment and the maximum evacuation and warning time according to the current situation in Korea. In order to propose the optimal location of the tsunami observation equipment, this study will analyze the tsunami propagation phenomena on the east sea by considering the potential tsunami scenario on the west coast of Japan through numerical modeling using the COrnell Multi-grid COupled Tsunami (COMCOT) model. Based on the results of the numerical model, this study suggested the optimal deployment of Korea's offshore tsunami observation instruments on the northeast side of Ulleung Island.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.3
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• pp.1-9
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• 2004

This study concentrates on the upwind schemes for convergence acceleration of the multigrid method for the Navier-Stokes equations. Comparative study of the upwind schemes in the Fourier space has been performed to identify why the second-order upwind scheme with enlarged stencil can be preconditioned better than the classical second-order upwind scheme. The full-coarsening multigrid method with implicit preconditioned multistage scheme has been implemented for verification of analysis. Numerical simulations on the inviscid and turbulent flows with the Spalart-Allmaras turbulent model have been performed. The results showed consistent trend with the analysis.

• Journal of the Korea Society of Computer and Information
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• v.21 no.7
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• pp.31-38
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• 2016

In this paper, we propose a direction for improving 'Geospatial information open platform' service to support the converged and integrated geospatial information. Since there can be a number of issues relating to the support for geospatial information convergence industry, two qualitative surveys were performed to collect opinions comprehensively and specifically. The responses from 165 experts from 5 areas that use geospatial information were used, and the requirements of demanders were divided into the aspect of policy, aspect of data development and distribution, and aspect of data utilization support in order to effectively analyze the survey results. As a result, a total of 26 major issues were derived and it was deemed that it is necessary to find a way to expand the role of 'Geospatial information open platform' from "Open-API Oriented Passive Spatial Information Open Platform" to "Platform that Comprehensively Provides Active Convergence Support Information" order to resolve the issues derived.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.2
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• pp.146-151
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• 2010

This paper proposes a rank-based control method of mutation probability for improving the performances of genetic algorithms (GAs). In order to improve the performances of GAs, GAs should not fall into premature convergence phenomena and should also be able to easily get out of the phenomena when GAs fall into the phenomena without destroying good individuals. For this, it is important to keep diversity of individuals and to keep good individuals. If a method for keeping diversity, however, is not elaborately devised, then good individuals are also destroyed. We should devise a method that keeps diversity of individuals and also keeps good individuals at the same time. To achieve these two objectives, we introduce a rank-based control method of mutation probability in this paper. We set high mutation probabilities to lowly ranked individuals not to fall into premature convergence phenomena by keeping diversity and low mutation probabilities to highly ranked individuals not to destroy good individuals. We experimented our method with typical four function optimization problems in order to measure the performances of our method. It was found from extensive experiments that the proposed rank-based control method could accelerate the GAs considerably.

• Annals of Clinical Neurophysiology
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• v.19 no.1
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• pp.40-45
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• 2017

Background: Telbivudine is a nucleoside analogue used for the treatment of chronic hepatitis B, but it often develops mitochondrial toxicity leading to symptomatic myopathy. In this study, three patients with telbivudine induced myopathy were enrolled in order to investigate the nature and pathogenesis of mitochondrial toxicity caused by long-term use of telbivudine. Methods: Clinical features, laboratory findings, muscle pathology, and quantitation of mitochondrial DNA were studied in three patients. Results: Patients presented with progressive muscle weakness with high serum creatine kinase levels. Light microscopic findings of muscle pathology showed ragged red fibers that reacted strongly with succinate dehydrogenase stain, but negative for cytochrome c oxidase activities. Electron microscopy revealed abnormal mitochondrial accumulation with rod shaped inclusions. The quantitative peroxidase chain reaction showed a depletion of mitochondrial DNA in skeletal muscle of the patients. Conclusions: Nucleoside analogues including telbivudine are potent inhibitors of viral DNA polymerases. However, they are not specific for viral DNA and can disturb mitochondrial replication at the same time. All nucleotide analogues should be used with close clinical observation in order to avoid development of mitochondrial myopathy.

• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.108-117
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• 2013

Studies on the regulation and measurement of greenhouse gases(GHGs) emissions have been carrying out for global wanning. In order to reduce greenhouse gas emissions, many countries have been promoting the Emissions Trading System and projects of the Joint Implementation(JI) and Clean Development Mechanism(CDM). These country's GHG emissions have been measured calculation criteria based on the Intergovernmental Panel on Climate Change(IPCC) Guidelines. In order to respond to GHGs regulation, in each country, it is planing to build a Low-Carbon City. The system has been developed for calculating GHGs emissions from companies and institutions in their respective countries. However, the system can monitor the GHGs per city, has not been developed. In this paper, it is studied to design the User Interface and to develop integrated monitoring program for Low-carbon city. This program will make possible monitoring and management, statistics, and reports written by using each data in units of cities.

• Journal of the Korea Society of Computer and Information
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• v.22 no.1
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• pp.143-151
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• 2017

In this paper, we suggest a method utilizing OSHW(Open Source HardWare) in order to raise up students who are competent in IT convergence and integration as a basic research to improve the university software education. Software education cannot be too much emphasized in the age of big change of Fourth Industrial Revolution. It hardly seems to have changes in the software education area of university where has to train competent technicians to be deployed into the industrial field, although software education is planned even in elementary, middle, and high school. In this situation, we expect that utilizing OSHW in software education can result in gaining a meaningful effect. However, we don't have various and systemic approach which use it as a education system component, unlike the response and necessity OSHW market. Therefore in this paper we suggest models which constitute software education environment based on OSHW and exemplify how to use it in each model. In addition, we compare and analyze each model in order to give a criteria to choice one of them according to the condition.

• ETRI Journal
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• v.33 no.5
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• pp.695-703
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• 2011

The number of adders and critical paths in a multiplier block of a multiple constant multiplication based implementation of a finite impulse response (FIR) filter can be minimized through common subexpression elimination (CSE) techniques. A two-bit common subexpression (CS) can be located recursively in a noncanonic sign digit (CSD) representation of the filter coefficients. An efficient algorithm is presented in this paper to improve the elimination of a CS from the multiplier block of an FIR filter so that it can be realized with fewer adders and low logical depth as compared to the existing CSE methods in the literature. Vinod and others claimed the highest reduction in the number of logical operators (LOs) without increasing the logic depth (LD) requirement. Using the design examples given by Vinod and others, we compare the average reduction in LOs and LDs achieved by our algorithm. Our algorithm shows average LO improvements of 30.8%, 5.5%, and 22.5% with a comparative LD requirement over that of Vinod and others for three design examples. Improvement increases as the filter order increases, and for the highest filter order and lowest coefficient width, the LO improvements are 70.3%, 75.3%, and 72.2% for the three design examples.

• Journal of Information Technology Services
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• v.16 no.1
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• pp.83-98
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• 2017

Broadcasting telecommunication convergence service means a service where broadcasting and telecommunication converge. Recently with the advancement of technology, broadcasting telecommunication convergence service has been evolving to provide multimedia contents through various devices including wired and wireless network environment. Up to now, IPTV and smartphone-based convergence services have been dominant, but more developed and evolved technology and media will appear in the future. In order to derive the next generation broadcasting telecommunication convergence service supporting model, this study derives an evaluation model of broadcasting telecommunication convergence service and presents a case of evaluation of 30 demonstration projects supported by the Korean government from 2010 to 2014. In this study, we derive an evaluation model and evaluate the demonstration projects by reflecting the position of the main stake holders of service such as users, experts, and related organizational institutions, away from the existing simple service evaluation method. Expert questionnaire used AHP (Analytic Hierarchy Process) method, and the evaluation results were divided into upper and lower groups to provide key implications by a gap analysis. From this analysis this study suggests guidelines for next generation broadcasting telecommunication service support projects. The next generation broadcasting convergence service business should be based on open platform type in terms of service type. In terms of service media, it should be centered on open devices such as smart phones and smart TVs. In terms of types of business responsibilities, it should be led by public organizations and it is necessary to increase the fund matching ratio by at least 62% when the private sector participates.