• Journal of Digital Convergence
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• v.18 no.1
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• pp.169-175
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• 2020

This study is to analyze the relationship between Taeoom(workplace bullying) and organizational performance and to investigate the mediating effects of organizational silence between the relationship among nurses. In order to test the causal and mediating effects, this study employs the mediation analyses with regression. The sample is 273 from A university hospital in Seoul. Based on the results, Taeoom is basically, negatively associated with organizational performance. Acquiescence silence has played a full mediating role in the relationship between Taeoom and organizational performance. That is, Taeoom is not directly associated with organizational performance; however, it has a negative effect on organizational performance through acquiescence silence. Defensive silence plays a partial mediating role in the interdependence relationship. The implications of this study are that the negative effects of Taeoom would increase organizational silence and performance directly and indirectly; therefore, it is necessary to provide institutional prevention of Taeoom.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.808-809
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• 2007

전력수요는 경기변동과 밀접한 관련성을 가지고 동행적으로 움직이며, 전력자료는 경제자료에 비해 조기 관측되는 선행성이 있다. 본 연구에서는 GDP 전망을 위해 발전량이 유용하게 사용될 수 있는가를 살펴 보았다. 발전량과 GDP의 관련성은 그랜저 인과관계 검정을 통해서 검증해 보았으며, 발전량 자료 취득의 선행성은 선행차수를 변화시켜 보면서 관련성이 어떻게 변하는가를 살펴보았다. 실제 자료를 이용하여 분석하고, 2004년부터 2006년 기간의 전망치를 평가한 결과, 본 논문에서 살펴 보고자 했던 발전량과 GDP 사이에는 아주 높은 관련성이 있음을 확인할 수 있었고 또한 발전량 자료를 이용함으로써 실제로 GDP 전망의 예측력을 상당히 개선시킬 수 있음을 볼 수 있었다. 발전량과 GDP 사이의 관계는 시간변동계수를 가지는 공적분 및 오차수 정모형을 이용하여 모형화하였다.

• Journal of Global Scholars of Marketing Science
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• v.16 no.3
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• pp.61-86
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• 2006

The main purpose of this study is to conceptualize and investigate the relationships between the antecedents and outcomes of customer satisfaction and the linking variables of brand preference and repurchase intention in service industries. To achieve this objective, the study tries to validate the structural equation model and causal relationships among the model's elements involving antecedents to customer satisfaction(perceived quality, value, equity), consequences(brand preference, repurchase intention), and moderating variable/switching cost, customer loyalty). Empirical findings are as follows: First, the effect of two antecedents/perceived quality and value) on customer. satisfaction was accepted but perceived equity was rejected. Second, I found out that there were direct or indirect relationships between the mediating variables/switching cost, customer loyalty, brand preference) and repurchase intention. This means that the proper management concerned with indirect path is probably more important for the success of services industries. Third, the direct effects of customer satisfaction and switching cost on repurchase intention were not significant against the existing studies excepting brand preference. This implies that repurchase intention was mainly intensified by the indirect path, 'customer loyalty${\rightarrow}$brand preference${\rightarrow}$repurchase intention' and 'switching cost${\rightarrow}$brand preference${\rightarrow}$repurchase intention.' The service marketers make efforts not only to strengthen the direct casual linkage but also to consolidate the indirect connections leading to create repurchase intention. Finally, the proper management of these structural relationships will help clarify the role of service marketer resulting in increasing sustainable competitive advantage in service industries.

• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.107-118
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• 2022

In this study, daily data from January 2002 to June 2022 were used to investigate the relationship between risk-return relationship and market fear, uncertainty, stock market, and maritime freight index for the crude oil market. For this study, the time varying EGARCH-M model was applied to the risk-return relationship, and the wavelet consistency model was used to analyze the relationship between market fear, uncertainty, stock market, and maritime freight index. The analysis results of this study are as follows. First, according to the results of the time-varying risk-return relationship, the crude oil market was found to be related to high returns and high risks. Second, the results of correlation and Granger causality test, it was found that there was a weak correlation between the risk-return relationship and VIX, EPU, S&P500, and BDI. In addition, it was found that there was no two-way causal relationship in the risk-return relationship with EPU and S&P500, but VIX and BDI were found to affect the risk-return relationship. Third, looking at the results of wavelet coherence, it was found that the degree of the risk-return relationship and the relationship between VIX, EPU, S&P500, and BDI was time-varying. In particular, it was found that the relationship between each other was high before and after the crisis period (financial crisis, COVID-19). And it was found to be highly associated with organs. In addition, the risk-return relationship was found to have a positive relationship with VIX and EPU, and a negative relationship with S&P500 and BDI. Therefore, market participants should be well aware of economic environmental changes when making decisions.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.11-22
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• 2017

To successfully create a low-carbon landscape in order to become a low-carbon city, it is necessary to understand the dynamics of artificial greening's resources on a multi-scale. Additionally, the effects of carbon storage should be quantitatively evaluated. The purpose of this study is to simulate and evaluate the changes in carbon storages of artificial ground trees using system dynamics throughout a long-term period. The process consisted of analyzing the dynamics of the multi-scale carbon cycle by using a casual loop diagram as well as simulating carbon storage changes in the green roof of the Gangnam-gu office building in 2008, 2018, 2028, and 2038. Results of the study are as follows. First, the causal loop diagram representing the relationship between the carbon storage of the artificial ground trees and the urban carbon cycle demonstrates that the carbon storage of the trees possess mutual cross-scale dynamics. Second, the main variables for the simulation model collected 'Biomass,' 'Carbon storage,' 'Dead organic matter,' and 'Carbon absorption,'and validated a high coefficient of determination, the value being ($R^2$=0.725, p<0.05). Third, as a result of the simulation model, we found that the variation in ranking of tree species was changing over time. This study also suggested the specific species of tree-such as Acer palmatum var. amoenum, Pinus densiflora, and Betula platyphylla-are used to improve the carbon storage in the green roof of the Gangnam-gu office building. This study can help contribute to developing quantitative and scientific criteria when designing, managing, and developing programs on low-carbon landscapes.

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.33-42
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• 2018

In the aftermath of an earthquake, seismic-damaged infrastructure systems loss estimation is the first step for the disaster response. However, lifeline systems' ability to supply service can be volatile by external factors such as disturbances of nearby facilities, and not by own physical issue. Thus, this research develops the bayesian model for probabilistic inference on common-cause and cascading failure of seismic-damaged lifeline systems. In addition, the authors present network robustness estimation metrics in the context of failure propagation. In order to quantify the functional loss and observe the effect of the mitigation plan, power and water supply system in Daegu-Gyeongbuk in South Korea is selected as case network. The simulation results show that reduction of cascading failure probability allows withstanding the external disruptions from a perspective of the robustness improvement. This research enhances the comprehensive understanding of how a single failure propagates to whole lifeline system performance and affected region after an earthquake.

• 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.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.669-674
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• 2006

The purpose of this study is to examine the effects of the factors on the usage level of e-business in the shipping companies. In order to do empirical analysis, firstly, this study carried out reliability analysis and factor analysis. Secondly, this study examined the effects of the factors on the usage level of e-business in the shipping companies by multiple regression analysis. In conclusion, the analysis result revealed that 5 factors effect on the service business usage's level and 4 factors effect on the real transaction usage's level of e-business.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.88-88
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• 2016

최근 우리나라에서 발생한 홍수 중 많은 관심을 불러일으킨 2010년 광화문 일대와 2011년 강남역 일대 홍수의 주요 원인은 하천관리를 통하여 대응해온 지금까지의 홍수와는 달리 도시의 우수배제 기능이 높은 강도의 강우에 대응하지 못한 것으로 분석되고 있다. 도시내부에서 발생한 이 같은 홍수는 도시의 기능에 심각한 영향을 줄 수 있으며, 거주민의 안전과도 밀접하게 연관된다. 본 연구에서는 도시의 기능과 거주민의 안전을 우선적으로 고려한 홍수 취약성평가 인자를 선정하고자 한다. 기존의 여러 홍수취약성 연구들에서는 취약성을 평가함에 있어 피해금액을 기준으로 적용하는 경우가 많이 있다. 장기적인 홍수대응, 완화 정책의 구상에 있어 예상되는 피해금액은 중요한 지표라고 볼 수 있다. 그러나 이 방법으로는 도시에서 발생 가능한 피해를 모두 반영하는데 한계가 있다. 도로, 지하철, 철도 등의 교통수단이 침수되는 경우, 피해회복을 위한 비용뿐만 아니라, 도시기능에 심각한 영향을 주어 도시의 생산성, 안정성에 막대한 피해를 남길 수 있다. 따라서 피해금액의 규모에 대한 접근만으로는 도시에서 발생한 홍수에 의해 피해를 받는 취약요인을 적극적으로 반영할 수 없다. 본 연구에서는 도시홍수 피해양상과 이에 대한 대응 방법 등 홍수의 물리적 위험성 뿐 아니라 홍수와 연관된 사회적인 요인들을 반영한 취약성 평가인자를 구성하기위하여 인자간의 인과관계 등을 고려하여 인자의 범위를 규정하고 델파이 설문조사와 문헌 연구를 통하여 전문가 의견을 수집, 분석하였다. 홍수취약성에 영향을 주는 요인들을 크게 3가지 그룹으로 정리하여 도시구조물, 거주민, 위험요인으로 구분하고 각 항목별로 영향인자을 선정하였다. 결정된 인자는 2011년 홍수피해가 발생한 도림천 유역에 적용하여 홍수취약성 평가를 수행하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.376-381
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• 2018

The purpose of this study is to investigate price transmissions between wholesale and retail markets regarding Jeju tangerines by employing co-integration analysis and vector error correction model. The results of this study are summarized as follows: First, the long-run equilibrium relationship was found among wholesale and retail markets in time series for level by distribution channel. Second, a short-run causality relationship was observed between wholesale and retail markets. Third, the long-run causality relationship between wholesale market and retail markets was found bidirectional and feedback effect. These results imply that the wholesale price performs a central role in establishing price in the tangerine market, and the wholesale market influences tangerine price. In conclusion, for the development of a competitive tangerine industry, it is necessary to aggressively promote the policy of supply and demand control of tangerine production through organizing producers.