• Communications for Statistical Applications and Methods
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• v.19 no.4
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• pp.559-569
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• 2012

Compositional data consist of compositions that are non-negative vectors of proportions with the unit-sum constraint. In disciplines such as petrology and archaeometry, it is fundamental to statistically analyze this type of data. Aitchison (1983) introduced a log-contrast principal component analysis that involves logratio transformed data, as a dimension-reduction technique to understand and interpret the structure of compositional data. However, the analysis is not usable when zero values are present in the data. In this paper, we introduce 4 possible methods to reduce the dimension of compositional data with zero values. Two real data sets are analyzed using the methods and the obtained results are compared.

• IE interfaces
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• v.15 no.2
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• pp.209-217
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• 2002

Quality of Service(QoS) in the telecommunications can be evaluated by analyzing the opinion data which result from the surveyed opinions of respondents and quantify subjective satisfaction on the QoS from the customers' viewpoints. For analyzing the opinion data, MOS(mean opinion score) method and Cumulative Probability Curve method are often used. The methods are based on the scoring method, and therefore, have the intrinsic deficiency due to the assignment of arbitrary scores. In this paper, we propose an analysis method of the opinion data using logit models which can be used to analyze the ordinal categorical data without assigning arbitrary scores to customers' opinion, and develop an analysis procedure considering the usage of procedures provided by SAS(Statistical Analysis System) statistical package. By the proposed method, we can estimate the relationship between customer satisfaction and network performance parameters, and provide guidelines for network planning. In addition, the proposed method is compared with Cumulative Probability Curve method with respect to prediction errors.

• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.97-102
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• 2003

데이터 마이닝의 여러 기법중 모형의 변동성을 줄이고 정확도가 높은 분류자를 형성하기 위하여 다양한 앙상블 기법이 연구되고 있다. 그 중에서 배깅과 부스팅 방법이 가장 널리 알려져 있다. 여러 가지 데이터에 이 두 방법을 적용하여 오분류율을 구하여 비교한 후 각 데이터 특성을 입력변수로 하고 배깅과 부스팅 중 더 낮은 오분류율을 갖는 알고리즘을 목표변수로 하여 의사결정나무를 형성하였다. 이를 통해서 배깅과 부스팅 알고리즘이 어떠한 데이터 특성의 패턴이 존재하는지 분석한 결과 부스팅 알고리즘은 관측치, 입력변수, 목표변수 수가 큰 것이 적합하고 반면에 배깅 알고리즘은 관측치, 입력변수, 목표변수 수의크기가 작은 것이 적합함을 알 수 있었다.

• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.241-254
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• 2020

This study proposes generalized models of joint latent class analysis (JLCA) for longitudinal data in two approaches, a JLCA with latent profile (JLCPA) and a JLCA with latent transition (JLTA). Our models reflect cross-sectional as well as longitudinal dependence among multiple latent classes and track multiple class-sequences over time. For the identifiability and meaningful inference, EM algorithm produces maximum-likelihood estimates under local independence assumptions. As an empirical analysis, we apply our models to track the joint patterns of adolescent depression and anxiety among US adolescents and show that both JLCPA and JLTA identify three adolescent emotional well-being subgroups. In addition, JLCPA classifies two representative profiles for these emotional well-being subgroups across time, and these profiles have different tendencies according to the parent-adolescent-relationship subgroups.

• The Journal of Industrial Distribution & Business
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• v.8 no.2
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• pp.21-31
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• 2017

Purpose - The total amount of advanced Corporate Pension Insurance products exceed 148 trillion Korean Won at the end of 2016. For a firm with over 300 employees, when a bill on compulsion of introduction of Corporate Pension Insurance products, currently pending in court, is passed, Corporate Pension shall be an essential. The findings of the paper will provide a guideline for understanding on firm's attributes and its effects towards introduction of Corporate Pension Insurance products. Research design, data, and methodology - The data were collected using statistics of employer panel survey from Korea Labour Institute in 2013. The study analyses a sample survey on 1,775 outstanding enterprises and their HR department among whole corporations in Korea. For analysis of data, empirical testing by Logistic Regression was utilized. Results - As an outcome of empirical testing, variables on share of regular employees and the aged employees in over 50's generates a significant statistical meaning. It eventually gives a great impact on purchase of Corporate Pension scheme. Moreover, variables on corporate financial statement, current sales, current net income, total amount of the debts, labor cost per person also has a vital influence on introduction of Corporate Pension Insurance products. Lastly, variables on firm's labor relationship have no effect except for the execution or non-execution of HR consulting. Meanwhile, Variables affecting a choice on pension schemes types among firm's attributes are a share of regular employees, current net income, execution or non-execution of HR consulting etc. These variables represents a statistical implication. According to their each features, they prefer DB or DC plan. Conclusions - Introduction of corporate pension scheme is apposite to contemporary Korea's situation entering a hyper-aging society and firms with a high share of regular employees, the weight of aging, current sales, current net income and labor cost per person are exceedingly active in purchasing Corporate Pension Insurance products. However, after the introduction of corporate pension scheme, firms which has an implementation of consultation on human resource management, flexible benefits plan, job security and welfare system prefer DC plan whereas from financial perspective firms with high net income prefer DB plan.

• The Korean Journal of Applied Statistics
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• v.35 no.4
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• pp.527-541
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• 2022

A company is a social group of many individuals that work together to obtain better results, and it is an organization that pursues common goals such as profit. As a result, forming networks among members, as well as individual communication abilities, is critical. The purpose of this research was to determine what factors influence the creation of employee advice relationships. Using the ERGM(Exponential Random Graph Model) approach, we looked at the network data of 44 individuals from consulting firms with offices in the United States and Europe. The significance of structural network factors like connectivity was first discovered. Second, the gender factor had the most significant main influence on the likelihood of adopting each other's advice. Third, geographical homogeneity resulted in higher link probabilities than major impacts of gender. This research looked at ways to make a company's network more efficient and active.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.275-281
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• 2022

This paper intends to provide a more effective understanding of the management performance (survival and growth) of startups and to suggest methods that can be applied to empirical research related to startups in the future. Therefore, in this study, the effect of entrepreneurship, trend analysis, and government support on business performance (non-financial and financial) is studied. A total of 220 questionnaires were received, and 215 were adopted except for 5 insincere questionnaires. Therefore, it was evaluated based on statistical data of 215 companies surveyed by startup officials. The questionnaire was analyzed using the SPSS 28.0 statistical program. The results of the study confirmed that all three items of the hypothesis, government support, entrepreneurship, and trend analysis of start-ups all play a positive role regardless of the difference in financial and non-financial management performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.10-20
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• 2017

The proportion of software in the automotive industry is steadily increasing due to the rapid technological development of automobile E/E parts. Because the automotive E/E technology is now on the basis of intelligent automobile and advanced safety automobile technology. The purpose of this study is to investigate the effect of organizational capability (organizational resource capability and management capability), process capability (process capability, customer Requirement management capability), performance dimension (motivation, participation level). In this study, we conducted questionnaires and statistical analysis on engineers (members of the Korea Advanced Automotive Technology Association) who perform research and development activities in the R&D organization of the automotive E/E part in South Korea. ANOVA is applied for the verification of the difference in performance measured by organizational capability, process maturity, and motivation participation level according to company characteristics (level of processing : supply chain configuration, annual sales, total SW development ratio). According to the results of this study, in order to improve the performance of ASPICE or ISO 26262-related consulting project, a different consulting approach strategy considering the characteristics of organization and personnel is needed. In summary, the analysis results for the three main treatment levels are as follows. The difference in organizational capacity, process capability and performance was found to be statistically significant according to supply chain configuration and annual sales, but it was found that the difference of response according to the proportion of total SW was not significant.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.173-181
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• 2021

In previous research, large companies were analyzed to focus on their past management performance and patent rights, but in this study we looked at the variability in future sales of small and medium-sized enterprises with patents through empirical analysis. We looked at how the quantitative and qualitative value of patent rights affect management performance of company. We used 'the number of patents' as the quantitative value of patents, 'the average score of patents' as the qualitative value of patents, and the average sales growth rate as the management performance of company. Through a discriminant analysis using the statistical program SPSS, both independent variables used in this study were significant for distinguishing between companies with an average growth in sales more than twice that of general small and medium-sized enterprises and those with less than twice the average sales growth rate. Therefore it is meaningful to provide stakeholders with an analysis framework on how sales will change in the future using the results of this study during guarantee or loan screening for small and medium-sized enterprises with patent rights.

• Journal of Distribution Science
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• v.15 no.10
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• pp.81-92
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• 2017

Purpose - One of the main objectives of this paper is to identify the most effective type of social media and to analyze the priority of blogs by their informational attributes in the aspect of their impacts on word-of-mouth intention(WOM) in on-line markets. Research design, data, and methodology - We set 'attitude' variable in the middle to see if there is mediating effects between blog information and word-of-mouth intention. We conducted a survey by questionnaire and received 206 answers. Employing the OLS statistical methods through the SPSS package, we tested our hypotheses. Results - Some of the main results are the followings. First, blog, micro-blog, and profile-based services showed significant effects on WOM, while Internet community and mini-homepages are not significant. Second, blog has positive impacts on WOM. Third, attitude has perfect mediating effects between blog and WOM. Fourth, in terms of effects on WOM, interactivity shows the first priority and reliability and usability follows. Finally, attitude has a more significant effect for users of 3 types of blog compared with those of 2 types. Conclusions - In this paper, we analyzed the effects of social network services by type and identified the priority among various attributes of information contained in blogs. It would provide businesses with viable strategic options to establish public relations in their sales promotion.