Showing 8 results for Comfort
Mohsen Aliabadi, Neda Mahdavi, Maryam Farhadian, Masoud Shafie Motlagh,
Volume 1, Issue 2 (12-2013)
Abstract
Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort.
Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan University of medical sciences, were studied using questionnaire with reliability coefficient equal to 0.8 was completed among 413 students. Measurement of noise level was performed using sound level meter (model TES-1358) according ANSI S12.6 in classrooms.
Result : The results showed the background noise level and outdoor noise level were equal 46.97 ± 3 dB(A), and 57.16 ± 4.8 dB(A) , respectively. The background noise was higher than the recommended limit equal to 45 dB(A) (P<0.01). The construction activities are most important annoying factor and concentration disturbance are most complication of noise. Signal to noise ratio within the classroom was 13.14±3.54 dB (A), which was inappropriate compared with the recommended limit 15 dB (A) (P<0.01). The difference in speech intelligibility at various levels of signal to noise ratio was significant (p<0.05).
Conclusion: The results confirmed the studied classrooms haven’t acceptable acoustic conditions and background noise level was affected by outdoor noise. In regard to confirmation of the effects of noise on the student attention, the acoustic interventions is must be considered.
Mehdi Ganji, Milad Karimi, Behnoush Bahari,
Volume 6, Issue 4 (3-2019)
Abstract
Background and Objectives: Due to the necessity of the proper driver packaging, setting parameters for the driver to achieve the highest ergonomics of the driver has a great importance. The range of variations in some parameters of the package is wide, and the correct selection of the packaging parameters until to achieve driver’s ergonomics position, requires some tests.
Methods: In this study, using the MINITAB16 software and using these parameters, several driving simulation were performed using the DHM (Digital human modeling) and DOE (Design of experiment) tools. Hence, for the C segment vehicles, the range of all driver’s package parameters, such as seat height, steering angle etc., was extracted using the A2MAC1 site, and was considered as the basis for the input parameter. According to the proposed tests by MINITAB16 software, the driver’s comfort level was evaluated based on the PORTER (1998) criteria.
Results: The seat height and also vertical and horizontal distances of the steering wheel to the accelerator heel point have the greatest impact on the driver’s ergonomics. Also, due to the high correlation between some of the parameters of the package and the ergonomics outputs of the body while driving, predictive equations were presented in this regard.
Conclusion: The results are the optimal model for ergonomic driving position. The most influential parameters of the driver’s package are ergonomically known and using the ANOVA (Analysis of variance), mathematical predictor models were presented.
Reza Shahidi, Rostam Golmohammadi, Zahra Pirmoradi Rizevandi, Azar Soltani, Nassrin Shirmohammadi Khoram, Reza Kazemi,
Volume 8, Issue 1 (5-2020)
Abstract
Background and Aim: Undesirable lighting at work environment causes visual and non-visual effects on employers. The aim of this study was to compare the quantity and quality of combined and artificial lighting in daytime and its relationship with the indexes of mental performance.
Methods: This study was carried out at 65 rooms and on 81 employees randomly selected from different clusters. Measurement of lighting parameters was done using a spectrometer. To assess the cognitive function, the Pshycomotor Vigiliance Task (PVT) test and for the sake of visual comfort, alertness and sleep quality, the Conlone, KSS (Karolinska Sleepiness Scale) and PSQI (Pittsburgh Sleep Quality Index) questionnaires were used respectively.
Results: Most artificial sources used in the rooms included fluorescent lights in different shapes and colors. The average indexes of combined lighting was more than artificial lightings (P<0.001). Visual comfort was correlated with high color temperature (P=0.006, r = 0.315). The employees with natural lighting had less visually impairment. The sleep quality of the subjects was related to the type of work environment lighting (Chi2=0.59, P=0.44). Alertness of subjects exposed to high color temperature or natural light was better at 8 and 11 hours. The results of cognitive performance test showed no significant difference between different lighting conditions.
Conclusion: Using natural light or artificial lights with adequate illuminance and high correlated color temperature can increase the alertness and visual comfort to some extent and improve the sleep quality of day staff employers.
Mostafa Rahmiani Iranshahi, Masoud Shafiee Motlagh, Elahe Dortaj, Maryam Farhadian,
Volume 9, Issue 4 (3-2022)
Abstract
Background and Objectives: Visual comfort is an important and influential factor on safety, mental health, sleep quality, and musculoskeletal disorders of employees in the workplace. This study aimed to design and develop a questionnaire to assess the visual comfort of employees in the workplace.
Methods: The study was performed on 101 participants (88 men and13 women) in the food industry. First, the available lighting questionnaires in the field of lighting were reviewed, and a question bank was set up. Twenty questions were considered in two sections of natural and artificial lighting (10 questions in each section) based on the opinion of 10 experts in this field. The validity of the questionnaire was assessed using the content validity index (CVI) based on the comments of experts. To validate the questionnaire in the workplace, The lighting of employees' workstations was evaluated according to the Illuminating Engineering Society of North America (IESNA) standards and compared with the results of the questionnaire.
Results: The Cronbach's alpha of natural and artificial lighting visual comfort questionnaire was 0.858 and 0.922, respectively. The total CVI of the questionnaire was 1. There was a significant positive relationship between the score of the visual comfort questionnaire and the workstations' illumination (P = 0.001). More than 97% of employees who had workstations with the desired lighting reported excellent levels of visual comfort.
Conclusion: The visual comfort questionnaire had good and acceptable reliability and validity. This tool is recommended for the use of visual comfort asessments of employees in work environments given the fewer number of and simplicity of sentences.
Azam Maleki-Ghahfarokhi, Iman Dianat, Mohammad Asghari Jafarabadi, Mohamad Parnianpour, Mahmood-Reza Azghani, Maryam Khosravifar, Sina Samadi,
Volume 10, Issue 1 (7-2022)
Abstract
Objectives: The comfort questionnaire for hand tools (CQH) is a subjective measure for exploring the starting points for improving hand tool design. This study aimed to investigate the psychometric properties of the Farsi version of the CQH.
Methods: In this cross-sectional study, which was conducted among 163 university students, the 17-question CQH was translated into Farsi with a translation back-translation procedure. Content validity was assessed by a panel of 10 experts. Exploratory Factor Analysis (EFA) was applied for determining construct validity. Cronbach’s alpha and Intraclass Correlation Coefficient (ICC) were used for assessing internal consistency and test-retest reliability, respectively. Ceiling and floor effects were also estimated for evaluating the feasibility of the measure.
Results: The CQH showed good content validity. Content validity index (CVI) ranged from 0.80 to 1.00 and Content Validity Ratio (CVR) ranged 0.62-1.00. EFA led to extraction of two factors from the data. The first one was mostly related to functionality and physical interaction and the second one, was generally about adverse body effects. The Cronbach’s alpha was 0.74 and test-retest reliability was 0.74 (95% CI = 0.58 to 0.86) which both were satisfactory. There were no (0%) ceiling and floor effects.
Conclusion: The Farsi version of CQH is an acceptable and useful instrument for evaluating hand tools comfort.
Morteza Mahdavi, Arezo Sammak Amani, Mohammad Amin Mououdi, Hadi Asghari,
Volume 10, Issue 2 (9-2022)
Abstract
Objectives: Providing safety for human resources in the industry is very important. Safety shoes are one of the most common PPEs that protect the foot against potential hazards. This study aimed to evaluate the discomfort and usability of safety shoes in different industries of Mazandaran province to find gaps in the quality of design and improve the design of safety shoes.
Methods: This was a cross-sectional study and was conducted in 2021.This study included employees of 11 different industrial companies that used seven safety shoe brands. They answered two researcher-made questionnaires, LPD (discomfort and general satisfaction) and SFUQ (usability). Data analysis was performed with Spearman rank correlation coefficient while Pearson correlation coefficient, and ANOVA test were also performed.
Results: In total, 226 men with a mean age of 36.33 ± 7.4 years were included in this study. The participants reported the lowest usability for the brand G (3.3 and 3.99), and the least discomfort and the most usability index with the brand A (1.2 and 5.35). Overall, the highest satisfaction was reported for brand A and the lowest satisfaction to brand G.
Conclusion: The findings of this study showed that the main problem in comfort and usability is probably related to shoe molds because the manufacturers of safety shoes import molds from abroad that do not fit the anthropometric characteristics of Iranian users’ feet.
Hamed Ahmadi, Mojtaba Noorllahi, Mohmmad Reza Soleimani, Ehsan Bitaraf,
Volume 10, Issue 4 (3-2023)
Abstract
Objectives: Human-made environments can have negative and positive effects on the planet. One of the two-faceted artifacts is the construction of buildings for people's lives, buildings that are being built irregularly and quickly and lead to excessive consumption of fossil resources and energy waste. Become Therefore, one of the most important things in the design of a building is providing its thermal comfort; Comfort that has a direct effect on the cognitive function of humans. In this research, in addition to the topic of thermal comfort, we also discuss fatigue in the classroom, which is one of the factors influencing the cognitive performance of the students.
Methods: In this research, the cognitive performance of people were examined and compared in the range of thermal comfort and the suggested range of the Ashri standard. To investigate their performance in different temperature ranges, 220 architecture students of Ilam universities were selected by systematic random sampling method. The state of thermal comfort, cognitive functions, and fatigue of people was evaluated after measuring environmental factors through questionnaires and standard cognitive function software.
Results: In addition to thermal comfort, which has a direct relationship with the cognitive performance of students, the passage of time is not an exception to this rule, in other words, the cognitive performance of students is derived from thermal comfort and the passage of time, which has a direct effect on academic, mental productivity. and also their practical efficiency. After examining the data in this regard, we reached meaningful results that indicate the highest efficiency of the students in the conditions of proper thermal comfort and the first 60 minutes of the start of their performance.
Conclusion: The results of this research show that even if the thermal comfort of the students' classrooms is provided according to the ASHERI standard, the students' cognitive performance will decrease after 60 minutes from the start of the class.
Mohammad Amin Mououdi, Arezoo Sammak Amani, Mohammad Taghipour,
Volume 11, Issue 2 (9-2023)
Abstract
Objectives: Nowadays, workers are less mobile and more sedentary due to the use of modern technologies in the workplace, and the complications resulting from static work and fixed posture have caused numerous disorders, including musculoskeletal disorders. This study was conducted to evaluate the comfort and usability of the ergonomic sit-stand desk converter with the aim of preventing disorders caused by constant sitting in workers.
Methods: 30 employees and faculty members of a university voluntarily participated in this study and provided informed consent. After the necessary explanations, subjects were provided with two researcher-created questionnaires ( Local Perceived Discomfort (LPD) and Sit-Stand Desk Converter Usability Questionnaire (SSDCUQ)), two methods of posture analysis, two methods of Workstation evaluation and general satisfaction along with 20-8-2 software and an ergonomic desk converter. After the test period, the data was analyzed using SPSS version 22 software and statistical tests such as mean, standard deviation, Spearman's rank correlation coefficient and Pearson correlation coefficient.
Results: The overall mean LPD in the different body parts was 0.48 ± 0.87, indicating that the converter functions in the range of no problem to very little discomfort. The average overall satisfaction with the function of the converter was 3.18 ± 1.08 ,which is in the medium to good range. When analysing the different sitting and standing postures, a significant correlation was also found between the different situations of using the converter (P<0.0005), which indicates an improvement in sitting and standing posture while using the converter.
Conclusion: Height-adjustable workstations are a good choice to reduce sitting time and improve posture. Despite the improvement in sitting and standing posture when using the converter, there are limitations, such as ignoring the software warnings for sitting and standing in the mechanical converter studied.
