• Title/Summary/Keyword: hazard function

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Development and Validation of an Integrated Healthy Workplace Management Model in Taiwan

  • Fu-Li Chen;Peter Y. Chen;Chi-Chen Chen;Tao-Hsin Tung
    • Safety and Health at Work
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    • v.13 no.4
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    • pp.394-400
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    • 2022
  • Background: Impacts of exposure are generally monitored and recorded after injuries or illness occur. Yet, absence of conventional after-the-effect impacts (i.e., lagging indicators), tend to focus on physical health and injuries, and fail to inform if workers are not exposed to safety and health hazards. In contrast to lagging indicators, leading indicators are proactive, preventive, and predictive indexes that offer insights how effective safety and health. The present study is to validate an extended Voluntary Protection Programs (VPP) that consists of six leading indicators. Methods: Questionnaires were distributed to 13 organizations (response rate = 93.1%, 1,439 responses) in Taiwan. Cronbach α, multiple linear regression and canonical correlation were used to test the reliability of the extended Voluntary Protection Programs (VPP) which consists of six leading indicators (safe climate, transformational leadership, organizational justice, organizational support, hazard prevention and control, and training). Criteria-related validation strategy was applied to examine relationships of six leading indicators with six criteria (perceived health, burnout, depression, job satisfaction, job performance, and life satisfaction). Results: The results showed that the Cronbach's α of six leading indicators ranged from 0.87 to 0.92. The canonical correlation analysis indicated a positive correlation between the six leading indicators and criteria (1st canonical function: correlation = 0.647, square correlation = 0.419, p < 0.001). Conclusions: The present study validates the extended VPP framework that focuses on promoting safety and physical and mental health. Results further provides applications of the extended VPP framework to promote workers' safety and health.

Telecommunication Service Usage as Predictor of the Timing of Handset Buyers' Replacement Purchases (통신서비스 이용행태 분석을 통한 휴대폰 교체기간 예측)

  • Park, Hyun Jung;Kim, Sang-Hoon
    • Asia Marketing Journal
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    • v.7 no.2
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    • pp.47-69
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    • 2005
  • With the explosive growth of mobile products industry, tons of newer versions of products are putting on the market. From the marketer's perspective, understanding consumers' replacement purchases, especially the replacement timing, is essential to product planning and selling. This study presents an approach to finding out factors influencing the timing of buyers' replacement purchases of cell phones, using duration analysis; a hazard function specification is applied to describe consumers' replacement timing decision. Based on the data collected from a mobile telecommunication company, five categories of factors have been inspected. These are consumer's innovative service usage, data service usage, voice service usage, participation in loyalty programs, and the demographic characteristics. The results of the study are as follows. Firstly, the positive coefficient of 'the number of related services used' suggests that the consumers who have more usage knowledge tend to replace faster. Secondly, customers participating in the membership service are positively associated with early replacement purchases. Lastly, younger customers(vs. older) and male(vs. female) customers turned out to replace cell phones earlier.

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A Case of Fence Entrapment Associated with Anti-Welfare in a Thoroughbred Colt with Misbehavior at a Paddock (행동장애를 가진 Thoroughbred 수망아지에서 반동물복지와 연관된 펜스함정 1례)

  • Yang, Jae-Hyuk;Park, Yong-Soo
    • Journal of Practical Agriculture & Fisheries Research
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    • v.18 no.1
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    • pp.25-28
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    • 2016
  • The welfare of horses depends on satisfying both the physiological and psychological needs of the animal. The object of this study was to evaluate fence safety at the horse farm. A Thoroughbred colt with cribbing was found dead in a paddock. The fence of paddock is a four-pipe fencing. He cribbed the 2nd pipe from the top. But he couldn't pull his face because his incisors acted as hooks and two ramuses of the mandible was entrapped in a top pipe. So he was embarrassed and went down while he terribly struggled to get out his face. Finally, he was strangulated to death. Safe fencing is essential on a horse farm. The function of these fences are to protect the horses but it was more of a hazard. In order to safe management of horses, facial length of the horse and the pipe interval of the fence should be considered. Further research is needed to put a muzzle on the horses while they are at a paddock. This study provides important benchmarks for the equine industry to consider fence type and evaluate fence safety.

Integrating physics-based fragility for hierarchical spectral clustering for resilience assessment of power distribution systems under extreme winds

  • Jintao Zhang;Wei Zhang;William Hughes;Amvrossios C. Bagtzoglou
    • Wind and Structures
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    • v.39 no.1
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    • pp.1-14
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    • 2024
  • Widespread damages from extreme winds have attracted lots of attentions of the resilience assessment of power distribution systems. With many related environmental parameters as well as numerous power infrastructure components, such as poles and wires, the increased challenge of power asset management before, during and after extreme events have to be addressed to prevent possible cascading failures in the power distribution system. Many extreme winds from weather events, such as hurricanes, generate widespread damages in multiple areas such as the economy, social security, and infrastructure management. The livelihoods of residents in the impaired areas are devastated largely due to the paucity of vital utilities, such as electricity. To address the challenge of power grid asset management, power system clustering is needed to partition a complex power system into several stable clusters to prevent the cascading failure from happening. Traditionally, system clustering uses the Binary Decision Diagram (BDD) to derive the clustering result, which is time-consuming and inefficient. Meanwhile, the previous studies considering the weather hazards did not include any detailed weather-related meteorologic parameters which is not appropriate as the heterogeneity of the parameters could largely affect the system performance. Therefore, a fragility-based network hierarchical spectral clustering method is proposed. In the present paper, the fragility curve and surfaces for a power distribution subsystem are obtained first. The fragility of the subsystem under typical failure mechanisms is calculated as a function of wind speed and pole characteristic dimension (diameter or span length). Secondly, the proposed fragility-based hierarchical spectral clustering method (F-HSC) integrates the physics-based fragility analysis into Hierarchical Spectral Clustering (HSC) technique from graph theory to achieve the clustering result for the power distribution system under extreme weather events. From the results of vulnerability analysis, it could be seen that the system performance after clustering is better than before clustering. With the F-HSC method, the impact of the extreme weather events could be considered with topology to cluster different power distribution systems to prevent the system from experiencing power blackouts.

Risk Factors Related to Development of Delirium in Hospice Patients (호스피스 병동의 암환자에서 섬망 발생 위험 요인)

  • Ko, Hae Jin;Youn, Chang Ho;Chung, Seung Eun;Kim, A Sol;Kim, Hyo Min
    • Journal of Hospice and Palliative Care
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    • v.17 no.3
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    • pp.170-178
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    • 2014
  • Purpose: Delirium is a common and serious neuropsychiatric complication among terminally ill cancer patients. We investigated risk factors related to the development of delirium among hospice care patients. Methods: Between May 2011 and September 2012, we included patients who were mentally alert and had no psychiatric disease or drug addiction at the hospice ward of two local hospitals. Among them, participants who had been diagnosed with delirium by two doctors according to the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-4th edition) criteria were grouped as Delirium Group. We analyzed results of psychometric and other laboratory tests performed at the time of patient's admission - psychometric tests included cognitive function (mini-mental status examination, MMSE), depression (Beck Depression Inventory, BDI), anxiety, and insomnia (Insomnia Severity Index, ISI). Logistic regression analysis was used to compare delirium and the related factors. Cox's proportional hazard model was performed using significant factors of logistic regression analysis. Results: Of the 96 patients who met the inclusion criteria, 41 (42.7%) developed delirium. According to the logistic regression analysis, primary cancer site, cognitive impairment (MMSE < 24), depression ($BDI{\geq}16$), and insomnia ($ISI{\geq}15$) were significant factors related to delirium. Among the four factors, depression (OR 5.130; 95% CI, 2.009~13.097) and cognitive impairment (OR 5.130; 95% CI, 2.009~13.097) were found significant using Cox's proportional hazard model. Conclusion: The development of delirium was significantly related to depression and cognitive impairment among patients receiving hospice care. It is necessary to carefully monitor depression and cognitive function in hospice care.

Study and Evaluation of an Incident Detection Algorithm for Urban Freeways (도시고속도로 돌발상황 감지 알고리즘 개발에 관한 연구 및 평가)

  • Seo Jeong-ho;In Sung-man;Kim Young-chan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.1 s.4
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    • pp.53-65
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    • 2004
  • A series of accidents, which are non-recurrent and non-anticipated, are called incidents. These incidents make standard traffic flows interrupt, which result in the decrease of road capacity and a number of social and economic costs, such as the traffic congestion and air pollution. In order to prevent the hazard of incidents, domestic and foreign traffic management center are likely to opt auto-sense system with algorithms of auto-incident sense. However, it is evaluated that the algorithms have a low function with frequent wrong alarms, even if they accurately ry to speculate the incidents. In the case of bottleneck which has lack of road capacity, compared with other roads, due to inefficient road structured over-capacity of the demand of on-off ramp, the incidents regularly take place. Nonetheless, it can be more difficult to speculate the auto-incidents sense owing to similar incidents, such as the queue of in-out flows of cars and the change of road line. Throughout this research, the function of the model has improved excluding near road line in the module of the incidents which is based on the auto-incidents algorithms during the sense of the congestion of ramp areas.

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An Improved Method of FTA and Associated Risk Analysis Reflecting Automotive Functional Safety Standard (자동차 기능안전 표준을 반영하는 개선된 FTA 및 위험원 분석 기법)

  • Jung, Ho-Jeon;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.9-17
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    • 2017
  • Ensuring the safety of automobiles and trains during system operation is regarded as indispensable due to the progress in unmanned operation. The automotive functional safety standard, ISO 26262, has been proposed to ensure the safe design of vehicles. This standard describes in detail the required risk analysis and evaluation procedure and safety measures, while appropriately reflecting the system design information. Therefore, much research has been done on the risk analysis procedure, wherein the design information is mostly extracted from physical components of similar systems already in operation, the information traced back to obtain constituent functions, and then methods of identifying risk sources are studied. This method allows the sources of risk to be identified quickly and easily, however if the design requirements are changed or systems are newly developed, others may be introduced which are not accounted for, thereby yielding mismatched design information. To resolve this problem, we propose a top-down analysis in order to utilize the system design information appropriately. Specifically, a conceptual system is designed to obtain the functions, which are then analyzed. Then, a function-based fault tree analysis is conducted, followed by a risk source analysis. In this paper, a case study of automotive safety is presented, revealing that the proposed method can analyze the risk sources with reduced possibility of omission by systematically reflecting the system design information.

A Comparative Study on the Infinite NHPP Software Reliability Model Following Chi-Square Distribution with Lifetime Distribution Dependent on Degrees of Freedom (수명분포가 자유도에 의존한 카이제곱분포를 따르는 무한고장 NHPP 소프트웨어 신뢰성 모형에 관한 비교연구)

  • Kim, Hee-Cheul;Kim, Jae-Wook
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.5
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    • pp.372-379
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    • 2017
  • Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

An attitude survey on the safety of the household utilities with the urban gas (설문에 의한 도시가스 사용가구의 안전의식도 조사)

  • Ko Jae-Sun;Kim Hyo;Lee SuKyoung
    • 한국가스학회:학술대회논문집
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    • 2005.10a
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    • pp.37-43
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    • 2005
  • The questionnaires about the safety of the urban gas have been carried out for the end users. about 8 of 10 persons said that the urban gas Is safe to use, whereas $35\%$ of them said there exists a hazard of an accident in thier residences. There cannot be found the clear evidences that the understandings on the safety of the urban gas have no relations to their ages, sex, and monthly incomes, while the safety is less confidential to the highly educated, the accident-experienced, or the mans who are poor at the safety inspections. Most of the questioned man know the inspection knacks for the gas utilities, but only $60\%$ of them carry out it. They said that they do not feel the necessity of the inspection because they are inspected routinely by the suppliers or the inspection companies. This says that the end user does not concern the safety inspections, and in order to improve the dependency of the user for the self-inspections, the inspection staff should educate the user for the necessity and the knack of inspections to encourage the self-inspection of the gas utilities.

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Shear-Rate Dependent Ring-Shear Characteristics of the Waste Materials of the Imgi Mine in Busan (부산 임기광산 광미의 전단속도에 따른 링 전단특성 연구)

  • Jeong, Sueng-Won;Ji, Sang-Woo;Yim, Gil-Jae
    • Journal of the Korean Geotechnical Society
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    • v.30 no.7
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    • pp.5-15
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    • 2014
  • Abandoned mine deposits are exposed to various physico-chemical geo-environmental hazards and disasters, such as acid mine drainage, water contamination, erosion, and landslides. This paper presents the ring shear characteristics of waste materials. The ring shear box with a rotatable O-ring was used in this study. Three tests were performed: (i) Shear stress-time relationship for given normal stress and shear speed, (ii) shear stress as a function of shear speed, and (iii) shear stress as a function of normal stress. For a given normal stress (50 kPa) and speed (0.1 mm/sec), the materials tested exhibit a strain softening behavior, regardless of drainage condition. The peak and residual shear stresses were determined for each normal stress and shear speed. The shear stress was measured when shear speed is equal to 0.01, 0.1, 1, 10, 50, 100 mm/sec or when normal stress is equal to 20, 40, 60, 80, 100, 150 kPa. From the test results, we found that the shear stress increases with increasing shear speed. The shear stress also increases with increasing normal stress. However, different types of shearing mode were observed in drained and undrained conditions. Under drained condition, particle crushing was observed from the shearing zone to the bottom of lower ring. Under undrained condition, particle crushing was observed only at the shearing zone, which has approximately 1 cm thick. It means that a significant high shear speed under undrained condition can result in increased landslide hazard.