• Journal of the Korean Data and Information Science Society
• /
• 제10권1호
• /
• pp.103-110
• /
• 1999

In this paper, we summarize some relative risk estimators under the two sample model with proportional hazard and examine the relative efficiencies of the nonparametric estimators relative to the maximum likelihood estimator of a parametric survival function under random censoring model by comparing their asymptotic variances.

• 응용통계연구
• /
• 제29권1호
• /
• pp.113-122
• /
• 2016

경시적 자료는 반복적으로 측정된 다변량 자료의 한 형태로 임상학, 보건학, 경제학에서 자주 발생된다. 시계열자료와 구분되는 가장 큰 특징은 표본수와 공변량 효과의 추정에 있다. 경시적 자료는 일반적으로 시계열 자료보다 더 큰 표본 개체로 이루어져 있으며 연구의 주 관심은 특정 공변량의 효과를 추정하는 데 있다. 또한 시계열 자료보다 반복 측정 횟수가 짧으며 개체마다 다른 관측 횟수와 다른 관측 중단 시점을 가질 수 있다. 본 연구에서는 관측 시점과 관측 종료 원인이 경시자료와 서로 연관된 경우에 결합 모형을 적용함으로써 이들간의 연관성을 분석하고자한다. 따라서 이들 변량간의 연관성을 모형화하기 위해 이변량 랜덤효과가 적용된다. 실제 자료 분석에서는 간경변증 환자의 핼액 응고 수치 시간을 관심 있는 경시적 자료로 환자가 병원 방문시점과 관측 중단원인들간의 상호 연관관계를 규명하고자 하였다. 특히, 중도 절단원인은 사망이나 간이식을 받는 사건일 때 발생하는데 본 연구에서는 사망 사건과의 연관성이 고려되었다. 결과를 통해 혈액 응고 시간이 길고 병원 방문 시점이 빈번할수록 사망할 가능성이 높음을 알수 있었다. 또한 혈액응고 시간이 길수록 병원 방문 횟수가 빈번하였다.

• 한국가스학회지
• /
• 제12권2호
• /
• pp.110-117
• /
• 2008

정량적 원인분석이 가능한 위험기반검사 프로그램(KS-RBI Ver. 3.0)을 사용하여 화학설비의 위험도를 산출하고, 설비의 위험도를 경감할 수 있는 방안을 모색하였다. 그 결과, 손상메커니즘, 검사횟수 및 검사 유효성을 고려하여 사고발생 가능성(LOF)을 줄이고, 검출, 차단 및 완화 시스템의 수준을 변경하여 사고 피해 크기(COF)를 감소시킴으로써 설비의 위험도를 낮출 수 있었다. 특히, 고 위험도를 낮추기 위해서는 LOF와 COF를 동시에 낮출 수 있는 방안을 모색할 필요가 있으며, 설비의 위험도를 경감함으로써 설비의 안전성 향상으로 사고피해 감소는 물론 검사주기 연장으로 검사비용 및 인건비 절감 등을 기대할 수 있다.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권2호
• /
• pp.309-315
• /
• 2021

Risks and uncertainty are unavoidable problems in management of projects. Therefore, project managers should not only prevent risks, but also have to respond and manage them. Risk management has become a critical interest subject in the construction industry for both practitioners and researchers. This paper presents critical risk factors of office building projects in the construction phase in Ho Chi Minh City, Vietnam. Data was collected through a questionnaire survey based on the likelihood and consequence level of risk factors. These factors fell into five groups: (i) financial risk factors; (ii) management risk factors; (iii) schedule risk factors; (iv) construction risk factors; and (v) environment risk factors. The research results showed that critical factors affecting office building projects are natural (i.e., prolonged rain, storms, climate effects) and human-made issues (i.e., soil instability, safety behaviors, owner's design change) and the schedule-related risk factors contributed to the most significant risks for office buildings projects in the construction phase in Ho Chi Minh City. They give construction management and project management practitioners a new perspective on risks and risk management of office buildings projects in Ho Chi Minh City and are proactive in the awareness, response, and management of risk factors comprehensively.

• Architectural research
• /
• 제24권2호
• /
• pp.21-27
• /
• 2022

For the past decade, South Korea had experienced catastrophic building fires, which resulted in consider-ably high number of casualties. This motivated research to develop fire-safe wall assemblies. In this study Fire Risk Analysis (FRA) is conducted as part of the project designing phase to ensure fire safety of the final product. Traditional approach was to consider fire performance at the end of the designing stage, when PASS/FAIL fire test results are required to be submitted to the Authority Having Jurisdiction (AHJ). By applying a fire risk analysis to guide the designing phase, overall fire safety of a wall assembly can be achieved more systematically as conducting FRA allows designers to clearly identify elements that are more vulnerable to fire and simply replace them with other practical options. Severity of fire risk is determined by considering the fire hazards of a wall assembly such as the exterior layer, insulation, vertical connectivity, and external ignition sources (e.g., photovoltaic panels). Frequency of fire risk is assessed based on the factors affecting fire likelihood, which are air cavity and fire-stopping applied in the design, and random design changes occurring during on-site construction. Fire risk matrix is proposed based on these fire risk factors and efforts to reduce the fire risk level associated with the wall assembly are given by systematically assessing the fire risk factors identified from fire risk analysis. Current study demonstrates how fire risk analysis can be applied to develop fire-safe walls by reducing the relevant fire risks- both severity and frequency.

• 한국콘텐츠학회논문지
• /
• 제8권10호
• /
• pp.342-350
• /
• 2008

본 연구는 서비스 상품의 구매상황에서 고객들이 인지하는 위험의 정도와 보유하고 있는 기업과 상품의 정보의 수준이 구매의사결정을 내리는데 필요한 정보를 탐색하는 채널 선택과 고객의 충성도에 어떤 영향을 미치는지에 대하여 연구 하였다. 연구결과 고객들이 인지하는 위험의 정도가 높고 보유하고 있는 정보의 수준이 낮을수록 공식정보채널 보다는 개인적인 정보채널을 선택하여 정보를 탐색하는 것으로 나타났다. 또한 인지하는 위험의 정도가 높을수록 해당 기업과 상품에 대한 충성도가 높아지는 것으로 밝혀졌으나 정보의 수준은 고객 충성도에 유의미한 영향을 미치지 않는 것으로 나타났다.

• Safety and Health at Work
• /
• 제8권1호
• /
• pp.89-93
• /
• 2017

Background: Rates of overweight and obese Australians are high and continue to rise, putting a large proportion of the population at risk of chronic illness. Examining characteristics associated with preference for a work-based weight-loss program will enable employers to better target programs to increase enrolment and benefit employees' health and fitness for work. Methods: A cross-sectional survey was undertaken at two Australian mining sites. The survey collected information on employee demographics, health characteristics, work characteristics, stages of behavior change, and preference for workplace assistance with reaching a healthy weight. Results: A total of 897 employees participated; 73.7% were male, and 68% had a body mass index in the overweight or obese range. Employees at risk of developing obesity-related chronic illnesses (based on high body mass index) were more likely to report preference for weight management assistance than lower risk employees. This indicates that, even in the absence of workplace promotion for weight management, some at risk employees want workplace assistance. Employees who were not aware of a need to change their current nutrition or physical activity behaviors were less likely to seek assistance. This indicates that practitioners need to communicate the negative effects of excess weight and promote the benefits of a healthy lifestyle to increase the likelihood of weight management. Conclusion: Weight management programs should provide information, motivation. and trouble-shooting assistance to meet the needs of at-risk mining employees, including those who are attempting to change and maintain behaviors to achieve a healthy weight and be suitably fit for work.

• Safety and Health at Work
• /
• 제10권2호
• /
• pp.172-179
• /
• 2019

Background: Workers exposed to hazards without adequate protections are at greater risk of injury and illness. Supervisor activities have also been associated with injury risk. We examined the interplay between supervisor safety support and occupational health and safety (OHS) vulnerability on workplace injury and illness. Methods: A survey was administered to 2,390 workers employed for more than 15 hrs/week in workplaces with at least five employees who had a direct supervisor. We examined the combined effects of hazard exposure with inadequate protection (OHS vulnerability) and supervisor support on workplace injury and illness, using additive interactions in log-binomial regression models. Results: OHS vulnerability and lack of supervisor support independently increased the likelihood of physical injuries at work. Crude and adjusted models showed that the risk of physical injury was at least 3.5 times higher among those experiencing both OHS vulnerability and a lack of supervisor support than individuals without OHS vulnerability and with a supportive direct supervisor. Workers who experienced vulnerability were at less risk if they had a supervisor who was supportive. Conclusion: In workplaces where workers experience one or more types of OHS vulnerability, having a supportive supervisor may play an important role in reducing the risk of injury and protecting workers.

• Journal of East Asia Management
• /
• 제3권1호
• /
• pp.25-40
• /
• 2022

This study investigates the effect of labor union and its power on information opacity. Given that the information opacity ultimately leads to the stock price crash, this study examines the relationship between labor unions and future stock price crash risk. Further, by assuming a strike by labor union as the actual power of the unionization in firms, whether labor union's power subrogated by the activity (i.e., a strike) makes a significant difference in the likelihood of future stock price crash between unionized firms is also examined. The work place survey data provided by Korea Labor Institute is used to test the hypotheses. The data is for the periods of 2004 - 2012 on firms listed on Korea Stock Exchange and KOSDAQ. The results show that while labor unionization has a positive impact on future stock price crash risk, on which labor union's power has a negative impact. This means that the existence of labor union itself might facilitate firm's information to be opaque by tolerating manager opportunism, while its power mitigates the managerial opportunism, which leads to lower future stock price crash risk. This study adds to the literature on the role of labor unions as nonfinancial stakeholders and its power in accounting environment, and also on the determinants of stock price crash. It is also valuable to examine the unions' role in terms of the economic consequences of both presence and power of the labor unions.

• 한국가스학회지
• /
• 제24권5호
• /
• pp.1-9
• /
• 2020

국내에서는 수소충전소 보급 및 상용화를 추진 중에 있으나 수소충전소에 대한 위험도 판정이 명확하지 않다. 특히 수소충전소에 대한 위험도 산출 방법 및 허용가능 기준이 명확하지 않은 실정이다. 이에 본 연구에서는 설치 중인 수소충전소 3개소를 선정하여 일반적인 위험도 산출 방법을 활용하여 각각의 수소충전소의 사회적 위험도를 계산해보았다. 일반적인 위험도 산출의 방법으로 개인적/사회적 위험도를 통한 사고빈도를 고려한 개인의 사망활률 및 인근주민의 수에 따른 사망 가능성을 통해 수소충전소의 위험도 수준을 산출할 수 있다. 그러나 이러한 위험도의 경우에도 허용가능 여부를 판단할 기준이 불분명한 실정이다. 이에 국외의 위험도 허용가능 기준을 조사하고 국내의 선정된 수소충전소의 위험도를 적용하여 허용가능 수준임을 고찰해 보았다.