Showing 4 results for Mehrabi
M. Kazempour, Mj. Jafari, Y. Mehrabi , I. Alimohammadi, J. Hatami,
Volume 8, Issue 2 (summer 2011)
Abstract
Background and aims
The influences of Low Frequency Noise (LFN) on mental performance have been the objectives of many papers in recent years. Many researchers believe that the LFN even at low pressure levels has impacts on mental performance. In the present work the influences of LFN and Reference Noise (RN) at two different sound pressure levels (45 & 65 dBA) on mental performances of college students during solving math problems were studied. Other factors such as annoyance and sensitivity to LFN and hearing status of the participants were also determined.
Material and Methods
Low Frequency and Reference Noise were generated and verified using Cool Edit software program. The number of participants was calculated using data gathered from a pilot study conducted in advance. The mental performance of the students was evaluated while they were exposed to LFN and RN at 45 & 65 dBA sound pressure levels. For this purpose, standard psychological tests were applied. Standard measuring instrumentation including sound level meters, psychological tests, acoustic room and etc were calibrated prior to their application based on standard methods.
Results
The results revealed that, Low frequency noise annoyance and sensitivity have no significant differences between different studied ages and sexes. The results also revealed that, a significant correlations exists between sensitivity to low frequency noise and deep mental process (r=0.33, p=0.01). It was recognized that low frequency noise at 65 dBA can decrease accuracy (pvalue=0.005) and performance (pvalue=0.001) in comparison with reference noise at the same level.
Conclusion
Low frequency noise, have impact on mental performance during performing math calculations
M.j Jafari, A.r Haji Hoseini1, Gh.h Halvani, Y Mehrabi, M Ghasemi,
Volume 9, Issue 3 (4-2012)
Abstract
Background and Aims: Human being as the designer, programmer, and operator of systems, equipment and machineries plays a significant role in their safety at present time. In a sophisticated system, the operators’ behavior has the potential of errors that can influence the capability of the system. In the present study, human errors of 400 kV posts were identified, analyzed and their reduction due to the application of proposed control measures were predicted.
Methods: After identification of key jobs affective on electric industry’s stability, the operator of 400 kV posts was selected as the sensitive and key joband analyzed using Hierarchical Task Analysis (HTA). The operator’s probable errors and their reduction were predicted using Systematic Human Error Reduction and Prediction (SHERPA).
Results: The results revealed that in 107 predicted errors at 6 main tasks and 61 sub tasks of 400 kV posts, the most frequent type of error was action error and the maximum predicted error was related to maneuvering task. The results also showed that about 95% of identified risks from errors were at unacceptable and undesirable level. It was predicted that if the recommended control measures were applied the unacceptable and undesirable risks would be reduced to 0 and 7.5% respectively.
Conclusion: It is possible to predict, identify and reduce the human errors in control rooms using SHERPA.
Davood Eskandari, Hossien Charkhanf, Mohamad Javad Jafari, Dr Yadolla Mehrabi,
Volume 17, Issue 1 (5-2020)
Abstract
Background and aims: Continuous improvement in safety is one of the important goals of successful organizations. The traditional method for assessing safety performance is the statistical analysis of incident data, which is known as lagging indicators. The use of lagging indicators cannot be useful since the goal of establishing a safety management system is continuous improvement. The purpose of this study is to provide a leading indicator for assessing the safety performance of the organization.
Methods: The present research is a mixed method study with the approach of the human factors theory that includes the organization, environment and individual factors. In this study, a scale developed and validated for assessing the factors affecting the safety of the organization. The fuzzy hierarchical process (FAHP) method was used to the weighting of the constructions In order to demonstrate the effect of different structures of the proposed scales on the safety performance index.
Results: a scale was developed with 83 items after the interview process to examine the factors affecting safety performance. Based on the results of face validity 6 items were eliminated. The mean value of the instrument's validity index was 0.77. According to the results of the fuzzy hierarchical analysis, the organizational factor with the highest weight load of 0.503 was the highest and the environmental factor with a weight of 0.173 had the least effect on the score of the organization's safety performance index.
Conclusion: Analysis of the study data showed that the designed scale is an objective and simple tool for evaluating the factors affecting safety performance and can be useful as a future performance indicator for assessing the organization's safety performance.
Keywords: Safety performance, Leading indicator, Fuzzy hierarchy method.
Fardin Mehrabian, Mohammad Simin Jorshari, Moein Zamani, Ali Sobhani Dargah, Yasaman Borghei, Asieh Ashouri, Mohammad Assadian Rad,
Volume 20, Issue 1 (3-2023)
Abstract
Abstract
Background and aims: Nurses are one of the most important elements of health care system that have been in a stressful situation during the Covid-19 pandemic. The aim of this study was to investigate the prevalence and sources of nurses' occupational stressand identify related factors during this period.
Methods: This cross-sectional study was performed on 392 nurses of Rasht educational and medical centers in January to March 2021 selected with stratified random method. Demographic and occupational stress data (by Expanded Nursing Stress Scale questionnaire) werecollected. Data analyses performed by descriptive statistics and multiple regression models with SPSS software version 26.
Results: The mean age of nurses were 37.8±8.8 years old. Stress was mild in 62% of nurses, moderate in 20% and severe in 2%. Death and dying situation (1/78±0/74), uncertainty concerning treatments (1.71±0.72) and workload (1.69±0.68), expressed higher occupational stress. Working in the intensive care units or emergency ward, higher education, excessive hours of work and female gender were independently predictors of more occupational stress and these characteristics determined 15% of the variance of stress scores.
Conclusion: Stress related to the job during the Covid-19 pandemic is high, and stress in the workplace, especially in intensive care units and emergency ward, should be reduced and standard work shifts should be developed. Furthermore, training of stress management in situations of patients’ death and dying, high workload and uncertainty concerning treatment in pandemic conditions for at risk population of nurses should be done.
