• The Korean Journal of Applied Statistics
• /
• v.20 no.1
• /
• pp.39-52
• /
• 2007

Crossover trials of new drugs in the treatment of angina pectoris, which frequently use treadmill exercise test for the assessment of its efficacy, produce censored survival times. In this paper we consider analysis approaches for censored survival times from crossover trials. Previously, a stratified Cox model for paired observation and nonparametric methods have been presented as possible analysis methods. On the other hand, the differences of two survival times would produce interval-censored survival times and we propose a Cox model for interval-censored data as n alternative analysis method. Example data is analyzed in order to compare these different methods.

• Journal of Digital Convergence
• /
• v.11 no.10
• /
• pp.153-168
• /
• 2013

Information security has been a major concern in organizations. The longstanding question of how to improve employees security behaviors and reduce human errors remains unanswered and requires further exploration in the information security domain. To do this, we propose a risk compensation theory-based model and examine the model. Research results shows that the relationships between information security countermeasures and information security compliance intention of employees are moderated by system vulnerability. However, the finding is contrary to the previously held risk compensation assumption and deserve further study. In addition, system quality does not play a moderator role in the relationship. Conclusions and implications are discussed.

• Life and Agrochemicals
• /
• v.29 no.10
• /
• pp.14-17
• /
• 2008

일반에게 공정한 입장에서 소비자와 커뮤니케이션을 실행하는 수단으로서 "일본농약학회, 지방자치단체, 내각부 식품안전위원회나 농림수산성, 후생노동성 등의 공적기관, 농약공업회나 전국농약협동조합 등 임의단체, 전국농업협동조합이나 전국 판매상 등의 유통업자 등이 실시하는 농약의 안전 사용자 안전 등에 관한 세미나 강습회, 소비자의 간담회", "학회나 농약연구자, 과학리더에 의한 계몽서의 출판, 학회나 업자 단체에 의한 Q&A집의 학회지 게재나 배포". "각종 학회나 공적기관의 홈페이지 계몽 해설문제의 게재", "농약제조 메이커나 임의단체에 의한 인터넷을 통한 메일 잡지 배송", "신문(전국지)를 매개로 한 홍보활동" 등을 들 수 있다. 최근에는 대학에 있어서도 일반사회인(소비자 포함)을 대상으로 한 농약이나 각종 화학물질의 안전성에 관한 공개강좌가 개설되어 있다. 한편 공정한 입장서 농약에 대해서 올바르게 전달한다는 개념에서 출발하지만, 결국엔 상업적 측면이 강한 "재미있고 우습게, 농약이 가지는 잠재적 위험성을 일부러 강조하고, 때로는 과학적 사실과 다른 내용을 의도적 또는 비의도적으로 전달하여 시청자나 독자의 관심을 끌어 시청률이나 발행부수를 신장시키는 것을 목적으로 하는 각종 매스컴으로부터의 막대한 양의 정보발신(모든 매스컴이 해당하는 것은 아님)이 있다. 더욱이 인터넷 사이트에는 종교적 측면이 강한 단체를 포함, 농약의 위험성을 강조하는 일이 있으며 온갖 정보가 넘쳐나고 있다. 물론 공적기관을 포함, 농약의 유용성과 잠재적 위험성에 대하여 공정하고 객관적 입장에서 인터넷을 소개한 정보 발신도 행해지고 있다. "농약은 나쁘고 위험하다"라는 정보로는 센세이셔날 한 상품가치(매스컴측의 보도 메리트)가 있지만 "농약은 안전하고 문제없다"로는 상품가치가 없다고 하는 상업 저널리즘을 드러낸다. "양적으로 압도적인 매스컴 보도"를 뛰어넘어 소비자에게 올바른 정보를 전달, 이해시키는 것은 가능하지 않을까. 다음으로 농약에 관한 리스크커뮤니케이션 수법에 대한 유의점과 과제를 기술한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2012.05a
• /
• pp.551-554
• /
• 2012

KARI is now developing KSLV-II which can insert 1.5ton satellite into the orbit, and system design review is close at hand. As a part of mission assurance for space launch vehicle, reliability and safety management is being performed and to assure the safety, KARI has been doing actions on the basis of the safety assurance plan and system safety program plan. In this study, preliminary hazard analysis is reviewed and the result for the propulsion system will be illustrated. The result will be used as a reference for the safety and risk management.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.05a
• /
• pp.146-147
• /
• 2023

해양사고는 도로교통과 달리 지속적으로 증가하고 있으며, 인명피해가 주로 발생하는 주요 사고의 치사율은 도로교통의 11.7배 이상이다. 해양사고는 외부 환경에 따라 사고 위치가 변하고 즉각적인 조치가 어려워 타 교통에 비해 대형 사고로 이어질 가능성이 매우 크다. 그러나 여전히 사고가 발생하고 난 후 대응하는 등 사후적 관리 단계에 무르고 있어 사고의 주요 요인을 사전에 식별·관리하는 선제적 관리단계로의 전환 필요성이 대두되고 있다. 따라서 본 연구에서는 해양사고 발생 지점 밀도 기반의 가변 공간 군집체계를 반영한 해양사고 예측모델을 개발하였다. 반복적인 공간 가산분석을 통해 밀도가 높을수록 작은 규모의 격자 체계를 가질 수 있도록 상세한 공간 군집체계를 구성하였으며, 단순 사고 위험도 예측뿐만 아닌 사고 인과관계를 설명할 수 있는 BN(Bayesian Network) 기반의 모형을 사용하여 해양사고 위험예측 모델을 개발하였다. 또한, Cost-of-Omission을 통해 해양사고 예측확률의 변화와 각 변수들의 영향력을 확인하였으며, 월별 해양사고예측 결과를 GIS를 활용하여 2D/3D 기반으로 시각화하였다.

• Journal of Digital Convergence
• /
• v.17 no.11
• /
• pp.149-156
• /
• 2019

With widespread use of information technologies, information privacy issues have been gaining more attention by not only the public but also researchers. The number of studies on the issues has been increasing exponentially, which makes incomprehensible the whole picture of research outcome. Thus, it is necessary to conduct a systematic examination of past research. This study developed two competing models with four essential constructs in information privacy research and empirically tested the models with data obtained from previous studies. This study employed a quantitative meta-analysis method called TSSEM. It is one of MASEM methods in which structural equation modeling and meta-analysis are integrated. The analysis results indicated that risk-centric model exhibited much better model fits than those of concern-centric model. This study implies that traditional concern-centric model should be questioned it's explanatory power of the model and researchers may consider alternative risk-centric model to explain user's intention to provide privacy information.

• Tunnel and Underground Space
• /
• v.17 no.5
• /
• pp.372-380
• /
• 2007

Surface damage due to subsidence is an inevitable consequence of underground mining, which may be immediate or delayed for many years. The surface damage due to abandoned underground mine is observed to be two subsidence types such as simple sinkhole or trough formation to a large scale sliding of the ground from with in the subsided area. An evaluation of the risk of a subsidence occurrence is vital in the areas affected by mining subsidence. For a subsidence prediction or a risk evaluation, there has been used various methods using empirical models, profile functions, influence functions and numerical models. In this study, a simple but efficient evaluation method of subsidence hazard is suggested, which is based on a diffusion theory and uses just information about geometry of caving and topography. The diffusion model has an analogous relationship with granular model which can explain a mechanism of subsidence. The diffusion model is applied for the evaluation of subsidence hazard in abandoned metal and coal mines. The model is found to be a simple but efficient tool because it needs information of geometry of caving and gangway and the topography.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.732-739
• /
• 2014

This research was performed to investigate the effect of recent climate changes on wood decay hazard index (Scheffer index) in Korea. The index was determined using a climate data of 58 different locations obtained from the website of Korea Meteorological Administration (KMA), and the wood decay hazard index was determined at the intervals of 10 years. Most of regions in Korea except Juju island showed wood decay hazard index values between 35 and 65, considered to be moderate decay hazard zones. But in recent 10 years (2003~2012), the wood decay hazard index was rapidly increased, resulting in showing many high decay hazard regions. The trend may be explained by the in crease of temperature and precipitation. The recent climate change of Korea turning into the weather of subtropical region may explain the increase of wood decay hazard index.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.3900-3914
• /
• 2012

This study examined the background of the recent global financial crisis and the concept of one of the financial derivatives such as the credit default swap(CDS) or synthetic CDO(collateral debt obligations), given the rapid growing and changing the over-the-counter derivative markets in their volume and structures. In comparison with the previous literature such as the study of Park & Kim (2011), this research empirically performed more thorough and comprehensive investigations to find any financial characteristics or attributes to determine the CDS spreads. Regarding the results obtained from the multiple regression models, the explanatory variables such as STYIELD3, SLOPE, INASSETS, and VOLATILITY, showed their statistically significant effects on all the tested dependent variables(DVs). Another procedure such as the principle component analysis(PCA), was also performed to account for additional IDVs as possible determinants of the dependent variables. Subsequent to this analysis, larger coefficients of each corresponding eigenvector such as BETA, PFT2, GROWTH, STD, and BLEVERAGE were found to be possible financial determinants. For robustness, all the IDVs were employed to be tested in the 'full' regression model with stepwise procedure. As a result, STYIELD3, SLOPE, and VOLATILITY, and BETA showed their statistically significant relationship with all the dependent variables of the CDS spreads.

• Journal of the Korean Society of Safety
• /
• v.22 no.6
• /
• pp.91-97
• /
• 2007

A survey of risk perception in Korea was conducted in 2001 with a special emphasis on industrial and technological risks. This article summarizes the characteristics of risk perception in consideration of socio-demographic background of respondents. The survey with sample size of 1,870 evaluates the perceived level of 25 risk items in the areas of transportation, chemicals, environment, industry, and nuclear power generation. Risks are categorized by using factor analysis to clarify attitudinal or behavioral properties of risk perception. Research findings show that the level of perceived risk does not correspond to the statistical level. Socio-demographic variables are significant predictors in explaining risk perception, or the discrepancies between "subjective" and "objective" risks. Effective risk communication can reduce the perceptional discrepancies, improve the awareness of technological risks, and ultimately facilitate the process of making and implementing policies for risk management and safety regulation. This article tries to provides policy guidelines for "Who is the target for risk communication" and "Which risk has the policy priority for safety improvement." Married females at the age of 30s and 40s with lower education and lower income in small cities are more vulnerable to risk misperception than other groups. More information and knowledge regarding unfamiliar, intangible, new technological risks should be delivered to the vulnerable groups for reducing perceptional bias. Society-wide safety can be improved by integrating policy, human, and social factors as well as techno-engineering advances.