• ETRI Journal
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• v.28 no.6
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• pp.793-795
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• 2006

When quadrature error exists, the shape of the M-ary phase shift keying (MPSK) signal constellation becomes skewed-elliptic. Each MPSK symbol takes on a different symbol error probability (SEP) value. The analytical results presented thus far have been derived from studies which examined the SEP problem assuming that the SEP of each MPSK symbol is equally likely; therefore, those results should not be treated as offering a complete solution. In this letter, we present a new and more complete solution to the SEP problem of MPSK by relaxing the above assumption and finding the expressions for the average as well as individual SEP in the presence of quadrature error.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1557-1564
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• 2017

We take genomic sequences of high-dimensional low sample size (HDLSS) without ordering of response categories into account. When constructing an appropriate test statistics in this model, the classical multivariate analysis of variance (MANOVA) approach might not be useful owing to very large number of parameters and very small sample size. For these reasons, we present a pseudo marginal model based upon the Gini-Simpson index estimated via Bayesian approach. In view of small sample size, we consider the permutation distribution by every possible n! (equally likely) permutation of the joined sample observations across G groups of (sizes $n_1,{\ldots}n_G$). We simulate data and apply false discovery rate (FDR) and positive false discovery rate (pFDR) with associated proposed test statistics to the data. And we also analyze real SARS data and compute FDR and pFDR. FDR and pFDR procedure along with the associated test statistics for each gene control the FDR and pFDR respectively at any level ${\alpha}$ for the set of p-values by using the exact conditional permutation theory.

• Journal of the Korean Data and Information Science Society
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• v.24 no.1
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• pp.189-200
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• 2013

In this paper, it will be assumed that there are two distinct populations which are multivariate normal with equal covariance matrix. We also assume that the two populations are equally likely and the costs of misclassification are equal. The classification rule depends on the situation whether the training samples include missing values or not. We consider the conditional bootstrap confidence intervals for classification error rate when a block of observation is missing.

• Journal of Information Science Theory and Practice
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• v.10 no.4
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• pp.38-52
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• 2022

Since older people are traditionally considered disadvantaged when it comes to Internet use, it is useful to examine whether older individuals use the Internet for health information seeking (HIS). This study aims to investigate digital inequalities in terms of Internet use by older population for HIS in the European region. As methods, we applied secondary data analysis (of Eurostat data) to investigate the influence of age, educational level, sex, and countries' wealth. Cluster analysis combined with multidimensional scaling was used to find out those countries exhibiting similarities in older people's online HIS. The main results are: Older individuals do not equally use the Internet in general and for HIS in particular. Older Internet users with higher level of education and of the female sex are more likely to use the Internet for health information.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.478-483
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• 2001

We experimentally attempted to understand the vibration characteristics of a flexible pipe excited by vortex shedding. This has been extensively studied in the past decades (For example, see ［2-9］). However, there are still areas that need more study. One of them is to study the relation between spatial characteristics of a flow induced vibrating pipe, such as its length, the distribution of wave number, and frequency responses. A non-linear mechanism between the responses of in-line and cross-flow directions is also an area of interests, if the pipe is relatively long so that structural modal density is reasonably high. In order to investigate such areas, two kinds of instrumented pipe were designed. The instrumented pipes, of which the lengths are equally 6m, are wound with rubber and silicon tape in different ways, having different vortex shedding conditions. One has uniform cross-section of diameter of 26. 7mm, and the other has equally spaced by 4 sub-sections, which are composed of different diameters of 75.9, 61.1, 45.6 and 26.7mm. Both pipes are towed in a water tank (200m ${\times}$ 16m ${\times}$ 7m) so that they experienced different vortex shedding excitations. The towing pipe experiments exhibit several valuable features. One of them is that the natural frequencies and their corresponding strain mode shapes dominate the strain response of the uniform pipe. However, for those of non-uniform pipe, the responses are more likely local and many modes participate in it.

• Journal of Family Relations
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• v.22 no.3
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• pp.47-72
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• 2017

Objectives: Do husbands with working wives share domestic labor more equally than husbands with unemployed housewives? Is the husband's contribution sufficient enough to satisfy his wife? These questions have long inspired many researchers to find ways to more accurately estimate husband's domestic contributions and narrow the emotional gap following the different threshold of satisfaction within couples, but not without some limits. This study attempted to figure out an answer to the above-mentioned subject by using time diaries of Korean married couples with a preschooler as their first-born child and relying on the typology of husbands' sharing of housework and childcare, which allowed me to overcome some limitations of prior research. Method: I analyzed a total of 1,716 diaries of 858 married couples from 2014 Korea Time Use Survey with descriptive statistics, t-test, cluster analysis, and multinomial logit. Results: Analytic results showed that husbands in dual-earner households did share domestic labor more equally than husbands in single-earner households, but there were different types of husband's contribution depending on time they spent in housework and childcare. While more than half of husbands with employed wives shared more or less than ten percent of domestic labor, the rest were divided into one group of husbands who shared both housework and childcare more heavily and evenly, and another group who were mainly involved in childcare duties. It is interesting that husbands who made the least contributions to domestic labor were not the ones with the lowest level of satisfaction with their sharing of household labor, whereas their wives were deeply dissatisfied, leading to a huge emotional gap within couples. Conclusion: Identifying factors associated with the three different types allowed me to find a point of intervention to narrow the emotional gap that is likely to harm the marital relationship if left unattended to.

• School Mathematics
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• v.15 no.2
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• pp.315-335
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• 2013

Probability has distinctive characteristics which are different from other areas of school mathematics. The critical change can be noticed in the domain, 'probability and statistics' of 2009 revised national curriculum for elementary school mathematics. This indicates that the concept of chance is supposed to be taught in the 5~6 grade band instead of the definition of probability which is moved to the middle school level. The purpose of this study is to seek desirable methods for teaching the concept of chance which reflect the achievement criteria and the attention point for teaching and learning of the curriculum at the point of time when textbooks haven't yet been developed. To do this, based on theoretical considerations and comparative analysis of the curricula in the longitudinal - latitudinal dimensions respectively, the validity of the latest curriculum change was confirmed and several learning activities were devised. And then two lessons were planned for applying these activities to eight fifth graders and were implemented along the plan. As a result, the relevance of the learning activities was examined and students' difficulties in learning the concept of chance with educational implications were discussed.

• Korean Journal of Health Education and Promotion
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• v.22 no.3
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• pp.49-63
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• 2005

Objectives: The study was designed to assess the trends of the incidence of HIV among young people and their sexual risk-taking behaviors by gender in Korean college students. Methods: The cross-sectional study was used from college students from selected 60 among 208 4-year colleges and universities in 9 provinces and Seoul. A self-reported anonymous questionnaire administered and completed to a national representative sample of 4-year college students from May 15th to June 14th in 2003. We analyzed 2,385 cases. The overall response rate was 82.0%. Results: After controlling age effects, male students were more likely to be sexually experienced than female students(40.0% vs. 8.1%), OR=5.5, p<.000. The proportions of 19 years and before reported for initiation of sexual intercourse were 18.6% for males and 3.2% for females. Males reported significantly younger ages than females at initiation of sexual intercourse(p<.01). Only 14.8% of current sexually active subjects reported consistent use of contraceptive methods. After controlling age effects, male students reported a higher proportion of sexually experienced respondents with one or more casual partners(excluding a formal partner) during the last 12 months than women(38.8% vs. 22.2%), OR=2.2, p<. 05. Conclusion : This study can conclude that although males students initiate sex earlier and have higher percentage of sexual experience, the percentage of sexually experience female students has risen rapidly compared to the past. This data revealed a number of young people were at risk for HIV infection. Both genders are equally likely to have engaged in inconsistent condom use even though when they have a sex with an unknown partner. These findings suggest that practical sex education focused on using condom use should have been included in the school curricular. Educational and community interventions need to prevent sex-related problems.

• Korean Journal of Legislative Studies
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• v.22 no.2
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• pp.157-188
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• 2016

Since democratic transition in the early 1990s, constitutionalism is getting more important for democratic consolidation in Africa. Using Afribarometer data set, this paper explains influences on public confidence in judiciary. High levels of public trust in judiciary is a necessary condition for judicial system to work effectively in emerging democracy. Unlike existing studies focusing on the function of judiciary and legal procedures, this paper is interested in the relationship between how ordinary Africans perceive the attitudes of the chief executive toward judiciary, the rule of law, and judicial corruption and their confidence in judiciary. The results show that those who think that the chief executive is likely to respect the constitution and the judiciary, that the law applies to everyone equally, and that there are few corrupt judicial personnel are likely to show high levels of confidence in judiciary. This study argues that the tension between laws and politics have a significant influence on transitional justice in emerging democracy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8C
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• pp.1086-1103
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• 2004

Most research efforts on the OCDMA technology assume single-bit-per-symbol transmission techniques such as on-off keying. However, achieving high spectral efficiency with such transmission techniques is likely to be a challenging task due to the "unipolar" nature of optical signals. In this paper, an M-ary transmission technique using more than two equally-weighted codes is proposed for OCDMA local area networks, and ie BER performance and spectral efficiency are analyzed. Poison frame arrival and randomly generated codes are assumed for the BER analysis, and the probability of incorrect symbol detection is analytically derived. From the approximation, it is found that there exists an optimal code weight that minimizes the BER, and its physical interpretation is drawn in an intuitive and simple statement. Under the assumption of this optimized code weight and sufficiently large code dimension, it is also shown that the spectral efficiency of OCDMA networks can be significantly improved by increasing the number (M) of symbols used. Since the cost of OCDMA transceivers is expected to increase with the code dimension, we finally provide a guideline to determine the optimal number of symbols for a given code dimension and traffic load.