risk assessment ارزیابی ریسک
background and aims: metro driving is one of the newest jobs in iran.for scarcity of studies on the tasks and hazards of metro drivers,we performed a task and hazard analysis of metro drivers to recommend control measures.methods: this qualitative study was conducted in metro organization in tehran during 2012-2013.in this mixed method study,data was collected through field observations,document reviews,individual interviews,focus group interviews and focus group discussions.many models and techniques include task analysis,organizational accident model,energy model,human factor analysis and classification,failure mode and effect analysis,fault tree analysis,event tree analysis,management oversight and risk tree,risk priority number,and lower and upper control levels were used to data analysis.results: metro driving has many tasks and hazards.most hazards were under upper control level while automatic train protection (atp) was active.in contrast,when atp was inactive,most hazards were over upper control level.conclusion: commitment to customer over commitment to safety was root cause of all of systematic failures and hazards in metro driving job and operation.establishment of permitto-work system can control many of hazards while atp is inactive.
the effects of past earthquakes have demonstrated the seismic vulnerability of confined masonry structures (cmss) to earthquakes.the results of experimental analysis indicate that damage to these structures depends on lateral displacement applied to the walls.seismic evaluation lacks an analytical approach because of the complexity of the behavior of this type of structure;an empirical approach is often used for this purpose.seismic assessment and risk analysis of cmss,especially in area have a large number of such buildings is difficult and could be riddled with error.the present study used analytical and numerical models to develop a simplified nonlinear displacement-based approach for seismic assessment of a cms.the methodology is based on the concept of esdof and displacement demand and is compared with displacement capacity at the characteristic period of vibration according to performance level.displacement demand was identified using the nonlinear displacement spectrum for a specified limit state.this approach is based on a macro model and nonlinear incremental dynamic analysis of a 3d prototype structure taking into account uncertainty of the mechanical properties and results in a simple,precise method for seismic assessment of a cms.to validate the approach,a case study was considered in the form of an analytical fragility curve which was then compared with the precise method.© 2017.techno-press,ltd.all right reserved.
the seismic hazard assessment of tehran,the capital of iran with a population of over 10 million,is necessary in the decision-making process for risk reduction.the main objective of this paper is to present a procedure for obtaining maximum hazard maps in seismically active regions such as tehran with a history of destructive earthquakes,but where the number of the instrumentally recorded large magnitude events is small.the deterministic and probabilistic seismic hazard methods are two quantitative approaches with some practical limitations.to overcome their limitations,the bayesian statistics are used to estimate maximum earthquake magnitude by combining prior seismological information with the available limited data.the bayesian approach is used to estimate maximum earthquakes corresponding to different individual ground-motion scenarios at a specific hazard level.the maximum hazard maps are obtained by merging different individual worst-case ground-motion scenarios at a specific hazard level.the hazard analyses under different scenarios are conducted by the finite-fault procedure which uses geological and seismological parameters for each seismic source.the obtained results are in agreement with the observed intensities of historical earthquakes.moreover,the conventional approach of probabilistic seismic hazard analysis is presented to show the difference between the two procedures.the findings provide information about the seismic design or retrofit of structures and infrastructures.© 2017 elsevier b.v.
background: manual handling of patients without using proper devices built for this purpose is the most important risk factor causing musculoskeletal disorders (msds) among nursing staff.objectives: the aim of the present study was to determine the prevalence of msds,assess the risk of manual handling of patients,and identify the risk factors related to the development of such disorders among nursing staff.methods: this cross-sectional study was conducted in 2015 and included 220 nurses from 24 wards who were working in baqiyatallah hospital,tehran,iran;their duties mainly involved patient handling.the participants were selected based on the random stratified sampling method.in this study,the nordic musculoskeletal questionnaire,demographic questionnaire,movimentazione and assistenza di pazienti ospedalizzati (mapo),and patient transfer assessment instrument (ptai) methods were applied as data collection tools.in addition,spearman correlation coefficients and binary and multiple logistic regressions were used to determine the possible relationships between the variables.results: the prevalence of msdsamongthe participants over the past 12monthswasfound to be 79.5%.the results for the risk factors showed that the lower back,neck,shoulders,and upper back were the most affected areas of the body.according to the mapo and ptai,60% and 40% of the wards,respectively,are at risk of msds.a significant relationship betweenmapoand ptai was found,with a coefficient correlation of 0.252.based on the statistical analysis,positively significant relationships were found between body mass index,gender,nurse-to-bed ratio,final ptai and mapo indices,and msds.conclusions: the prevalence of msds among the nurses was high,and the occurrence of such disorders was found to be related to the scores of mapo and ptai indices.based on the results,these two indices can be used as appropriate tools to assess the risk of msds in patient handling by nursing staff.the risk of developing msds can be lowered through interventional programs,such as providing and equipping hospitals with the tools required for patient handling and educating staff on how to properly use such devices.in addition,increasing the nurse-to-bed ratio will lower the burden for the nurses in patient handling.© 2016,iranian red crescent medical journal.
the multi-criteria decision analysis (mcda) and the geographical information systems (gis) are used to provide more accurate decisions for decision makers in order to evaluate the effective factors of the natural science.one of the popular algorithms of the multi-criteria analysis is the ordered weighted averaging (owa).the owa procedure depends on some parameters which can be specified by means of the fuzzy logic.the aim of this study is to take the advantage of incorporating the fuzzy logic into gis-based soil fertility analysis by owa in the west of shiraz,fars province,iran.in fact,different soil fertility maps with different risk level are prepared in the present study.this study introduces a method for farmers in case of make balance between their budget and their farm soil parameters.a farmer can accept more risk it can use more areas for farming and also the amount of needed budget increases too.for determining the soil fertility maps,the owa parameters such as potassium (k),phosphor (p),copper (cu),iron (fe),manganese (mn),organic carbon (oc) and zinc (zn) were used.after generating the interpolation maps with the inverse distance weighted (idw),the fuzzy maps were generated by the membership functions for each parameter.finally,by utilizing owa,six fertility maps with different risk levels (degrees of uncertainty) were made.the results show that by decreasing the risk (no trade-off),increasing the risk,more area within the study area was suitable in terms of the soil fertility.therefore,using owa can generate many maps with different risk levels.this leads to different managements based on different financial conditions of farmers.© 2016