• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.231-242
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• 2007

This study was conducted to identify the relation of bottleneck and satisfaction factors in Korean succession companies. The final goal of this paper is finding some strategies and supporting system for Korean succession companies. According to the results of the study, we found four latent variables of the cause variables and two latent variables of the result variables. Three latent variables of the cause variables have an direct effect on two latent variables of the result variables.

• Journal of Preventive Medicine and Public Health
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• v.49 no.2
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• pp.80-96
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• 2016

Recently, a series of lawsuits were filed in Korea claiming tort liability against tobacco companies. The Supreme Court has already issued decisions in some cases, while others are still pending. The primary issue in these cases is whether the epidemiological evidence submitted by the plaintiffs clearly proves the causal relationship between smoking and disease as required by civil law. Proving causation is difficult in tobacco lawsuits because factors other than smoking are involved in the development of a disease, and also because of the lapse of time between smoking and the manifestation of the disease. The Supreme Court (Supreme Court Decision, 2011Da22092, April 10, 2014) has imposed some limitations on using epidemiological evidence to prove causation in tobacco lawsuits filed by smokers and their family members, but these limitations should be reconsidered. First, the Court stated that a disease can be categorized as specific or non-specific, and for each disease type, causation can be proven by different types of evidence. However, the concept of specific diseases is not compatible with multifactor theory, which is generally accepted in the field of public health. Second, when the epidemiological association between the disease and the risk factor is proven to be significant, imposing additional burdens of proof on the plaintiff may considerably limit the plaintiff's right to recovery, but the Court required the plaintiffs to provide additional information such as health condition and lifestyle. Third, the Supreme Court is not giving greater weight to the evidential value of epidemiological study results because the Court focuses on the fact that these studies were group-level, not individual-level. However, group-level studies could still offer valuable information about individual members of the group, e.g., probability of causation.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.11a
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• pp.141-168
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• 2001

본 연구는 초고속인터넷 접속서비스에서 $\ulcorner$서비스 품질$\longrightarrow$고객만족$\longrightarrow$재구매의도(고객충성도)$\lrcorner$의 일반적인 인과관계가 적용되는지를 규명하고, 고객만족, 재구매의도와 고객충성도에 영향을 미치는 서비스 품질속성을 살펴보면서, 궁극적으로 품질속성 중 고객유지와 충성도를 향상시키는 핵심 품질요소를 도출하기 위한 모형을 이론적으로 제시하고, 그 모형의 유효성을 설문조사와 이에 대한 실증분석을 통해 평가하는데 목적이 있다. 모형을 검증하기 위하여 세 단계의 분석과정을 수행하였다. 첫째, 전반적 서비스 품질과 고객만족, 재구매의도(또는 고객충성도), 그러고 고객만족과 재구매의도 및 고객충성도의 상호관계를 검증하였다. 둘째, 고객만족, 재구매의도 및 고객충성도에 영향을 미치는 선행변수인 품질속성(서비스 성능, 서비스 지원, 부가서비스, 이용요금, 과금, 절차 편리성)들의 영향력을 검증하였다. 마지막으로 공통적 개념으로 분류된 품질속성이 개별적인 품질요소의 미세한 차이를 제대로 반영하지 못하는 단점을 극복하고, 고객유지와 충성도 향상을 위한 핵심 품질요소를 도출하기 위하여 품질속성을 대표하는 품질요소들과 재구매의도와 고객충성도의 상관관계를 살펴보았다. 초고속인터넷 접속서비스 이용자를 대상으로 웹설문조사를 실시하여 총 551 개의 표본을 분석에 사용하였으며, 분석결과는 다음과 같다. 첫째, 서비스 품질은 재구매의도와 고객충성도에 비해 고객만족에 높은 설명력을 갖고 있으며, 재구매의도에 대한 서비스 품질과 고객만족의 설명력은 미미한 것으로 나타나, 고객만족이 더 높은 설명력을 갖는다는 기존의 연구와 차이를 보여 향후 추가적인 연구의 필요성이 제기되었다. 둘째, 여섯 가지의 품질속성들 중 서비스 이용과정에서 1, 2 회의 적은 경험을 하게 되는 서비스 이용절차의 편리성을 제외하곤 나머지 속성 모두 고객만족, 재구매의도 및 고객충성도의 선행변수로써 영향을 미치고 있는 것으로 나타났다. 그러나 절차 편리성은 고객충성도에 유의한 영향을 미치는 것으로 나타나, 충성도는 고객이 서비스를 총체적인 관점에서 평가하고 나타나는 행동이라는 시사점을 얻었다. 셋째, 재구매의도와 고객충성도를 결정하는 품질요소로서는 서비스 안정성, 불만사항 처리결과, 회사의 이미지, 다양한 부가서비스가 도출되었다. 본 연구의 결과는 초고속인터넷 접속서비스의 품질 및 결과변수들에 대한 인과관계를 분석하였다. 그리고 경쟁이 치열해지는 시장 환경에서 미래의 재무적 성과와 수익성을 보장하는 충성스런 고객을 확보하기 위하여 필수적으로 관리되어야 할 핵심 품질요소의 제시와 이에 따른 제언을 하였기 때문에 사업자들이 품질 및 마케팅 전략을 수립함에 있어서 이론적, 실무적 근거를 제공하여 준다.

• The Journal of Society for e-Business Studies
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• v.24 no.4
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• pp.109-118
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• 2019

As a result of the United States (U.S) -China trade conflict, the recent instability of the stock market has led many people to invest in Bitcoin, a commodity that many previous studies have interpreted as a safe asset. However, recent Bitcoin market price fluctuations suggest that the asset's stability stems from speculative purchasing trends. Therefore, classifying the characteristics of Bitcoin assets can be an important reference point in analyzing relevant accounting information. To determine whether Bitcoin is a safe asset, this study analyzed the correlation between Bitcoin and economic indicators to verify whether gold and Bitcoin responded similarly in time series analyses. These show that the regression explanatory power between the price of gold and bitcoin is low, thus no relation between the two assets could be drawn. Additionally, the Granger causality analyses of six individual economic variables and Bitcoin did not establish any notable causality. This can be interpreted that short-term price fluctuations have a significant impact on the nature of Bitcoin as an asset.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.387-387
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• 2021

지구온난화와 기후변화로 인한 강우패턴의 변화는 가뭄, 홍수 등의 피해를 증가시키고 있다. 그 예로 2020년 여름 장마는 1973년 이후로 가장 긴 장마로 기록되었다. 이 장마는 제주도를 제외한 우리나라 전역에 평균 858 mm의 강수량을 발생시켰다. 장마로 인해 많은 지역에서는 도시침수와 하천범람이 발생하였으며 인적 그리고 물적인 피해를 입었다. 게다가 극한강수의 미래변화는 평균 강수량의 증가와 더불어 빈도도 증가하리라 전망한다. 따라서 심화되는 극한 기우 현상의 피해를 대비하기 위해서 수문순환이라는 시스템에 대한 이해가 필요하다. 구조방정식모형은 특정 현상에 대한 인과관계를 분석하기 위한 다변량 분석방법 중 하나로, 사회과학 분야에서 널리 사용되었으나 최근 자연과학 분야에서도 응용되고 있다. 구조방정식모형을 사용하여 관측된 자료가 이론 및 경험을 토대로 구축된 모형과 충분히 부합하는지를 검증할 수 있다. 구조방정식모형은 변수 간의 영향의 크기와 영향이 직접 혹은 간접적으로 작용하는지를 확인할 수 있고 모형에 대한 통계적인 평가로 연구모형이 수용 가능한지를 판단할 수 있다. 따라서 구조방정식모형을 사용하여, 수문순환의 모형을 구축하고 수문특성 간의 영향을 확인할 수 있다. 본 연구에서는 수문요소의 인과관계와 상관관계를 파악하기 위해 구조방정식모형을 적용하였고 2010년부터 2018년까지 설마천 유역과 청미천 유역의 연단위 강수량, 기저유출량, 직접유출량, 증발산량을 사용하였다. 각 유역에서의 수문특성과 수문요소 간의 관계를 확인하고 수문순환 모형을 구축/평가를 하였다. 그 결과, 서로 다른 유역이지만 비슷한 구조방정식모형을 갖는다는 것을 확인하였다.

• The Korean Journal of Applied Statistics
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• v.28 no.5
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• pp.871-883
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• 2015

Vector autoregressive (VAR) models in high dimension suffer from noisy estimates, unstable predictions and hard interpretation. Consequently, the sparse vector autoregressive (sVAR) model, which forces many small coefficients in VAR to exactly zero, has been suggested and proven effective for the modeling of high dimensional time series data. This paper studies coupling measures to select non-zero coefficients in sVAR. The basic idea based on the simulation study reveals that removing the effect of other variables greatly improves the performance of coupling measures. sVAR model coefficients are asymmetric; therefore, asymmetric coupling measures such as Granger causality improve computational costs. We propose two asymmetric coupling measures, filtered-cross-correlation and filtered-Granger-causality, based on the filtered residuals series. Our proposed coupling measures are proven adequate for heavy-tailed and high order sVAR models in the simulation study.

• International Area Studies Review
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• v.14 no.3
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• pp.86-107
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• 2010

Prior research on the relationship between output volatility and growth has produced mixed results, failing to provide clear empirical evidence on the sign of the relationship. In this paper, we raise the possibility that such failure is due to misspecification in empirical models previously used, i.e., not taking into account the business cycle dependence of the volatility-growth relation. We set off with the conjecture that higher volatility exerts qualitatively different effect on growth depending on whether the economy is in expansion or contraction. We estimate a series of ARCH-type models with the monthly industrial production data of the U.K., and find strong evidence suggesting that the volatility-growth relation is positive when the economy is in expansion, while higher volatility lowers growth rate in the contraction phase. We also find evidence supporting that the volatility-growth relation estimated in the paper captures a a causal relation, not a bidirectional correlation.

• Journal of dental hygiene science
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• v.6 no.2
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• pp.107-111
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• 2006

This study purports to investigate the determinants of intent to leave of dental hygienists working at dental clinics. The sample used in this study consisted of 356 dental hygienists selected from nationwide Korea. The independent variables contain three groups of determinants: 6 structural variables, 2 psychological variables and one environmental variable. Job satisfaction and organizational commitment were included in the model as intervening variables. Data were collected with self-administered questionnaires and analyzed using path analysis. The results of the path analysis indicate that the following variables have significant total effects on the intent to leave of dental hygienists: organizational commitment, supervisory support, job satisfaction, alternative job opportunity, positive affectivity, role conflict and job autonomy. The results imply that the administrators of dental clinics should make an effort to motivate dental hygienists by redesigning their work process, to provide them with more autonomy in doing their work, and to develop their job knowledge and skills through continuous training and education.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.309-315
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• 2021

Purpose of this study is to analyze the correlation between the level of smartphone overdependence and depression among the high school student. Study subjects were 50 high school student. The assessment of the level of smartphone overdependence was used by the smartphone overdependence scale for adolescents and the assessment of the level of depression was used by Korean ver. of patient health questionnaire-9. As the results, the positive correlation was showed between the level of smartphone overdependence and depression and the statistically significant difference was showed. It was found that the higher the level of smartphone overdependence among high school students, the higher the level of depression. The smartphone overdependence among high school students could contribute to increase the level of depression. Thus, based on these results of this study, it is necessary to consider to reduce the level of smartphone overdependence and depression among high school students and subsequent studies should be conducted to clarify the casual relationship and influences of the level of smartphone overdependence and depression among high school students.

• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.303-324
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• 2008

From mid-1890's, biometricians and Mendelians debated over Darwin's evolutionary theory. Biologist W. Weldon and Mathematician K. Pearson were leaders of the biometric school and biologist W. Bateson led Mendelian school. In this paper topics of the controversy such as causation vs. correlation, frequency distribution are considered. And in relation to the tradition of British statistics, we consider the philosophy of Karl Pearson revealed in this debate. Besides many statistical methods and concepts by Karl Pearson, the newly born mathematical statistics got a new journal Biometrika, a department in university, and a school of researchers from this controversy.