• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.846-854
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• 2017

In this paper, we proposed a method to reduce the error of compass by combining the ceiling technique used in the past with modern IT technology. We combined an encoder and the Azimuth Circle for applying an algorithm. The algorithm is able to calculate the true north by using astronomical observation. Finally, we implemented the embedded system possible to indicate various situations and perform calculations. As a result, it isn't only able to calculate the true north with an error of about $0.2^{\circ}$ but also takes less than 5 seconds. Originally, using astronomical observation requires more than 5minutes. So it is analyzed as convenient by solving the problem of taking lots of time. Especially, we present the tolerance less than $0.5^{\circ}$ by the analysis of the existing gyrocompass and the bearing standard of IMO. In conclusion, we clearly confirm that the results of this paper are possible to reduce the error of various compasses in a real world.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1082-1092
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• 1996

The design of distrbuted systems is difficult to achieve as the execution patterns of distrbuted systems are typically more complex than those of non- distributed systems. Thus, research toward the development of design methods for distributed systems is quitely needed. As object-oriented systems and distrbuted systems share similar properties, the combination of these two is somehow natural. In this work, a design of distributed systems is introduced. The goal of the method in this paper is to provide assistance to the process of specifying a formal object- oriented specification from graphical representation specification inputs such as data flow diagrams, state transition diagrams and Petri nets. It addresses the extraction of objects, operations and reationshipsfrom the problem domain with emphasis on the specification of the characteristics of distributed systems. This object identification method is supported by a knowledge base that provides for the automated analysis and reasoning about objects and their relationsships. The final object model is represented in a format which provides a formal mechanism for reprsenting the object information.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1103-1111
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• 1996

The design of distrbuted systems is difficult to achieve as the execution patterns of distrbuted systems are typically more complex than those of non- distributed systems. Thus, research toward the development of design methods for distributed systems is quitely needed. As object-oriented systems and distrbuted systems share similar properties, the combination of these two is somehow natural. In this work, a design of distributed systems is introduced. The goal of the method in this paper is to provide assistance to the process of specifying a formal object- oriented specification from graphical representation specification inputs such as data flow diagrams, state transition diagrams and Petri nets. It addresses the extraction of objects, operations and reationshipsfrom the problem domain with emphasis on the specification of the characteristics of distributed systems. This object identification method is supported by a knowledge base that provides for the automated analysis and reasoning about objects and their relationsships. The final object model is represented in a format which provides a formal mechanism for reprsenting the object information.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.41-56
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• 2016

This study investigates the employment and spatial mismatch as a significant acting factor of deepening urban poverty and analyses the placeness of regional labor market that the more efficient place-based labor market intervention needs to take into account. The change of unemployment rate as a regional labor market outcome in metropolitan cities is determined by the dynamic interaction between disequilibrium of labor supply and demand and employment mismatch according to various labor market conditions and its process is certainly differentiated across the metropolitan regional labor markets. In addition, it is analyzed that during the employment suburbanization the spatial mismatch puts differentiated impacts on different labor groups through human capital requirements and industry-selective job opportunities. As a result, because this whole process works with its unique process within individual regional labor markets, in order to link between urban poverty and employment mismatch and to promote problem-solving labor market intervention, we need to develop place-based policy based on the placeness of regional labor marekt.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.392-399
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• 2005

Shear modulus (or rigidity) of dam material is an important parameter which can be directly associated with the deformation of dam. Seepage or leakage of water can cause the defects or cracks of dam body. The existence of cracks and rigidity of dam body are decisive information for the estimation of dam safety. Rigidity of material is mainly determined from S-wave velocity and the defects of dam body can be detected by seismic reflection survey. Therefore, seismic reflection survey will be a desirable method which can give a solution about dam safety problem. Among various physical properties of dam body, S-wave velocity is the most important information but it is not easy to get the information. In this study, diverse measuring techniques of S-wave reflection survey were attempted to get the information about S-wave velocity of dam body. Ultimately, S-wave velocity could be estimated by the analysis of SH reflection events which can be easily observed in shot gather data obtained from SH measuring technique. Meanwhile, P-wave reflection survey was also performed at the same profile. P-beam radiation technique which can reduce the surface waves and reinforce the P-wave reflection events was applied for giving a help to analyse P-wave velocity. In the end, P-and S-wave velocity, Vs/Vp, Poisson's ratio distribution of the vertical section under the profile could be acquired.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6A
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• pp.455-464
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• 2005

In this paper, we implement resource allocation algorithm based on the WiBro system which including OFDMA, TDD, and we propose the algorithm in order to increase bandwidth efficiency. In this algorithm, data is allocated from the subchannel which has large channel gain to the subchannel which has small channel gain with maximum modulation order. The moment total power is more than available power, the modulation order of the latest subchannel is adjusted. The problem of decreasing of throughput in large channel attenuation environment is solved by allocating additional power. Still, this algorithm has large bandwidth efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.391-400
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• 2009

Recently, cellular communication networks are migrating from 2G to 3G. Spectrum utilization tends to be inefficient during the transition. Cognitive radio (CR) technology can be a key solution to increase spectrum efficiency by allowing secondary networks to utilize frequency resource of primary networks. However, conventional CR approaches which do not utilize the frequency reuse factor of primary networks may incur degradation of whole network performance. In this paper, we propose a mechanism that a secondary network senses pilot signals of a primary network and select optimum frequency bands. In order to maximize whole network performance, we formulate an optimization problem subject to interference constraints for a primary network and present algorithms. Simulation results compare the proposed method with the conventional method. Our proposed method shows performance gain over the conventional method if channel variation of a primary network is dynamic and the frequency reuse factor of a primary network is high.

• Korean Journal of Health Education and Promotion
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• v.28 no.1
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• pp.23-35
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• 2011

Objectives: This study aims to identify the impact of subjectively reported oral health status on the quality of life by applying the PRECEDE model. Methods: This study was conducted on a total of 450 people who had dental visit experience among persons above 35 and under 65 years living in Seoul and Gyeonggi provinces. Oral health-related quality of life was measured using the OHIP-14. The relationship between subjectively reported oral health status and the quality of life was evaluated by the chi-square test, t-test, one-way ANOVA and multiple linear regression analysis. Results: OHIP-14 scores were significantly associated with self-reported oral health problem. Especially the strongest correlations were found between functional limitation, physical psychological social disability on the OHIP-14 7 sub-factor and self-reported periodontitis and dry mouth symptoms. Conclusion: Subjectively reported oral health status is associated with oral heath related quality of life. In order to improve people's the quality of life, taking care of their oral heath is indispensable factor. Therefore, it is required to revitalize regular oral health check system and the development of effective oral health education programs by the government to prevent periodontitis and dry mouth as well.

• Journal of Families and Better Life
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• v.31 no.5
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• pp.19-32
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• 2013

The purpose of this study was to identify the influences of psychological independence(functional independence and emotional independence) and career decision-making self-efficacy(self-estimation, career goal, occupational-knowledge, and problem solving) on career maturity(preparation, objective, decisiveness, and certainty) among adolescents. The subjects were 447 students in the second grade of middle school and high school in D. The questionnaire consist of measures of psychological independence, career decision-making self-efficacy, and career maturity. The data were analysed with factor analysis, Cronbach's ${\alpha}$, t-test, ANOVA, correlation and multiple regression by using the SPSS(SPSS/WIN 19.0) program. The major results were as follows. First, adolescents' the career maturity was significantly different depending on the socio-demographic variables. Second, it was shown that middle and high school students have a statically relation, in a relation among psychological independence, career decision-making self-efficacy, and career maturity. Third, it was found that psychological independence and career decision-making self-efficacy gave statistically meaningful influence on the career maturity of adolescents. This study is significant in that it suggests a plan for improving career maturity, and provides a basic material to improve one's active role in their parents. In addition, the results of this study can be used as a fundamental reference in career development programs and career-counseling centers at schools for enhancing adolescents' career development and success.

• Convergence Security Journal
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• v.11 no.6
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• pp.73-80
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• 2011

In this study, software products developed in the course of testing, software managers in the process of testing software and tools for effective learning effects perspective has been studied using the NHPP software. The delayed software S-shaped reliability model applied to distribution was based on finite failure NHPP. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than automatic error that is generally efficient model could be confirmed. This paper, numerical example of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error and $R^2$(coefficient of determination).