محمد کوهی

One of the important types of crashes on rural roads is run-off way crashes. These types of crashes have a significant share in rural road crashes. Roadside safety improvements can greatly reduce the frequency and severity of run-off Road crashes. One important and practical equipment to prevent vehicle departure from the road is safety barriers. Safety barriers can reduce the consequences of vehicle departure, which can be fatal or result in severe injuries. Determining the quantitative impact of this countermeasure on reducing crashes severity can assist road safety authorities in economically evaluating it based on severity reduction, comparing it with other safety countermeasures, and ultimately deciding to implement it or choose other optimal options. Accordingly, the present study selects a rural axis in Ilam province to determine the quantitative impact of safety barriers on reducing the severity of run-off Road crashes, and analyzes the crashes data from 2 years before the installation of barriers and 3 years after using the before-after Bayesian analysis method. The research findings show that safety barriers can reduce fatal crashes by 41% and injury crashes by 42%.

Emotions are central to all aspects of human experience and are an integral part of principals' jobs and lives. Due to the nature of their job, elementary and high school principals need to be aware of their own and others' emotions and manage their emotions. These observations suggest that the emotional aspect of leadership warrants further investigation. The present study aimed to validate the Principals' Emotions Inventory (Chen, 2020). The statistical population of the study was all elementary and high school principals in Mashhad who were engaged in management in the academic year 2020-2021. The sample size determined 450 people based on Cochran's formula. Participants were selected by the available sampling method. Principals' Emotions Inventory, after translation and validation, was distributed and completed electronically and in pencil and paper format among the research sample. Confirmatory factor analysis was used to determine the validity of the structure and the alpha coefficient was used for reliability. The results confirmed the fit of the model and the structure of the internal relations of the items. The alpha coefficient for the Principals' Emotion Inventory was equal to 0.85 and for the factors of enjoyment (0.88), pride (0.96), frustration (0.86), anxiety (0.85), and hopelessness (0.89). The results showed that the principals' emotions inventory has acceptable psychometric properties and can be used as a valid instrument in the study of principal emotions.

In this paper, two structures of surface plasmon resonance fiber optic biosensors with the addition of a thin layer of titanium dioxide and barium titanate are introduced and studied comparatively. The sensitivity of these biosensors has been calculated using the transfer matrix method. Adding a thin layer of barium titanate and titanium dioxide after the gold layer, both make increase the sensitivity of the biosensor due to the transfer of free charge between the gold and the dielectric. The obtained results of the comparative study show that the titanium dioxide layer can be a suitable alternative to barium titanate for further increase of the sensitivity of the fiber optic surface plasmon resonance biosensor.

For a long time, controlling the speed of vehicles, or in other words, controlling the behavior of drivers in adopting speed, has been and is one of the most important challenges for road safety engineering. In this regard, there are various tools for controlling the speed of vehicles on the roads, the most important tool used all over the world is the use of speed limit signs. To determine the speed limit when constructing roads, there is a common trend that the relevant authorities are more or less familiar with. However, determining the appropriate speed limit on existing roads after several years of operation requires speed Scrutinize studies, That The country's road engineering community is not well known. The goal of speed Scrutinize studies on an axis is to obtain the speed limit for vehicles. In order to acquaint the engineering community of the country with this issue, in this research, the speed Scrutinize study has been used to determine the speed limit on the Semirom-Yasuj axis. The present study is based on the study of speed-based research in 2016. The method used is that after the traffic studies and the available data, the study axis is based on the aerial maps of the initial segmentation and after the field visit, the final segmentation is obtained. Speed information is also measured in two ways: point speed and garlic speed. Finally, the information is analyzed and the speed limit of each part is determined.

Existence research for to evaluate the effectiveness of a series of Countermeasures in reduction crashes on the Malayer-Jokar axis in Hamadan province. In this axis, in 2015, a series of Countermeasures have been implemented during three months. To determine the effectiveness of the set of Countermeasures, Crashes data were used 19 months before and 19 months after the implementation of these Countermeasures. Due to its high efficiency in estimating the expected accidents without implementing Countermeasures and also eliminating the phenomenon of regression, the business method was used to average. The high accuracy of this method is due to the use of safety performance function (SPF) in order to logically estimate the frequency of crashes in the period before the Countermeasures. A crash prediction model was used using AASHTO (2010). Using this tool and predicting crashes before and after the implementation of Countermeasures, as well as the calculation of the expected number of crashes in the before and after periods, the effectiveness of safety was calculated. The results showed that the combination of these Countermeasures reduced the crashes by 4 percent. Although the significant assessment of this value showed that it is not significant at the 90 percent confidence level, the result is still valid, and this small amount of accident reduction, as the type of collisions observed in the after period has shown, is most likely due to the fact that Some Countermeasures have led to a reduction in certain types of crashes and an increase in other specific types.

Identifying the factors that contribute to injury as a result of crashes will help policy makers and road designers implement countermeasures, which could reduce crash injury severity, and cost. In result, objective of this study is identifying factors are more likely to contribute to crashes severity. Today, Researchers have utilized mathematical and statistical modeling-schemes to solve this complex road-safety problem. For this, discrete choice modeling is widely used to model injury severity of the crash. From the models, factors contributing to the injury severity are identified. MNL is the most prominent discrete choice model for modeling crash severity. For modeling, the data of a 5-year period of crashes occurred at the rural roads of Ilam province has been used. The input variables of the model were selected after a significance evaluation test. These variables included Age, Speed, Alcohol, Head-on, Airbag, Ejection, Seatbelt, following too Close, Gender, and Curved. After selecting the variables, the accuracy of the model was also studied. To validate the model, the likelihood ratio and the percent correctly predicted by the model at each crash severity level were used. After evaluating the model accuracy in the prediction of accidents severity, it was found that the model provides acceptable results for evaluating crashes severity, and it was found that except curve and following too close variables, all selected variables contributing in crashes severity.

In this research, researchers are looking to prioritize countermeasures in one of the important intersections of Darrehshahr city. The four countermeasures including installing a traffic signal, installing a speed hump in the minor approach, drawing a stop line in the minor approach +sign and creating a rumble stripe in the major and minor approach for this intersection are considered. The research method is the economic evaluation method in HSM. In the economic evaluation of countermeasures, the costs of fatal crashes, injuries and damages for the year 1399 have been calculated. Also, the expected crashes before and after the implementation of the countermeasures and the reduction in the frequency and severity of the crashes caused by the implementation of the countermeasures have been estimated. By calculating the annual benefits of crashes reduction and calculating the current value of benefits, assuming a 3 percent discount rate and a service life of 10 years for countermeasures, cost-benefit analysis and cost-effectiveness of countermeasures have been performed. The results show that according to the Benefit-Cost Ratio method, the stop line in the minor approach +sign, the creation of the rumble stripe in the major and minor approach, the installation of the speed hump in the minor approach and the installation of the traffic signal have priority, respectively. Also, for every million Rials spent on the implementation of the stop line in the minor approach +sign, the ratio of benefit to cost during the 10-year lifespan is 396508.5 to 1.

Determining the numerical value of the safety effectiveness of countermeasures or the Crash Modification factor (CMF) is one of the issues that has received considerable attention in recent years in the world. In this regard, several studies have been carried out to determine the CMF for converting intersection to roundabout in different countries. The results of these studies have led to a reduction of about 35 to 70 percent of crashes at the intersections. Since there is no serious study regarding determining CMF of constructing a roundabout and the percentage of crash reduction due to this countermeasure in Iran, the researchers are seeking to determine the CMF and reduction percentage of the crashes due to this measure in Iran. For this purpose, Salman Farsi roundabout of Ilam city was evaluated. AADT rates were obtained from the available traffic counts and crash data from the police. For determining CMF, empirical Bayes method was considered. The reason for using empirical Bayes method is its high efficiency in removing the phenomenon of regression to mean and other time-alteration factors and the high precision of this method is due to the use of SPF in order to reasonably estimate the frequency of crashes in the period prior to countermeasure. During studying, a SPF from AASHTO 2010 was used. Using this tool and predicting crashes before and after the construction of the roundabout, as well as calculating the frequency of expected crashes before and after it, the effectiveness of safety was calculated. The results for crash frequency is as crash CMF and crash frequency reduction percentage indicates a CMF of 0.68, implying a 32 percent reduction in crash. The statistical significance evaluation of this reduction shows that the 32 percent reduction of crashes after constructing roundabout is significant at 90 percent confidence level.

The shoulder width of the main roads has risen by 35% by revising the Highway Geometric Design. In this research, determination of the effect of simultaneously increasing shoulder width and its paving on decreasing crashes in rural two-way two-line highways was targeted. The studies were conducted in Ilam province highways and the experimental empirical Bayes (EB) method was used. Several highways sections with narrow shoulders paved or non-paved were selected as reference groups and crash data, traffic flow, and their geometry was collected and modeled. Three types of crash prediction model (SPF) were created for the total number of crashes, fatal crashes and shoulder related crashes in the cold seasons (autumn and winter) using the negative binomial regression model for the reference group. Some sections of which shoulders had become safety by widening and paving were also selected as an improved group. To estimate the crash modification factor (CMF), the expected crashes in all improved sections were summed up and then compared with the total number of observed crashes in the period after the countermeasure. The EB method was also repeated twice for the improved group of improving the narrow shoulder to the wide and paved shoulder. Once with the SPF for each of the three crash categories, considering the improved group may not be well-matched with the reference group, and once only with the SPF of the total crashes. The results showed that Widening and paving the shoulders affects considerably on the safety of the shoulders related crashes in the cold seasons with CMF of about 0.42 (58% reduction) and the fatal and injuring accidents with CMF of about 0.72 (28% reduction). It can also contribute to a 12 percent improvement of the total crashes of the cold seasons.

In the present research, the relationship between family structure and academic failure is considered with mediator role of  identity styles. The research method was correlation of path analysis. The statistical population consisted of all Secondary school students in the Khorramabad city. A sample of 365 students was selected using multi-stage random sampling and Purposive method. The research instrument consisted of Family structure Questionnaire (FAD) and Identity Styles (ISI), and the average less than 15 considered as a criterion for academic failure. For data analysis the path analysis method was used. Based on the results the research proposed model was approved. There was no direct relationship between family structure and academic failure, but there was an indirect relationship through all the components of identity styles, Also, there was a direct relationship between family structure and all components of identity styles. In addition, among the components of identity styles, two components of confused-avoidance identity styles and informational identity showed a direct relation with academic failure. In sum, the family structure through the identity styles as an influential mediator, can affect students' academic failure. Therefore, the central role of styles of identity and family structure should be at the center of attention of interventions and planning related to improving the academic performance of students.

The present study aims to investigate and study the understanding of the risk of drivers in Ilam city in terms of traffic rules according to age variables, level of education, accident records, driving experience and number of fines per year, using a questionnaire developed and distributed among drivers in the city level and their collection were completed after being completed by the drivers to achieve the results that have the greatest impact on increasing the level of understanding of the risk. Components of traffic behaviors, traffic views, and risky behaviors were considered as components of driver risk perception to be evaluated for all drivers according to the variables mentioned. The results showed that higher education did not make high-educated people more likely to be at risk. Also, as people age, their understanding of traffic hazards and their legitimacy increases dramatically. People who have less than 1 year of driving experience have a better understanding of the risk than people who have 1-2 years or 3-5 years of driving experience. But from the fifth year onwards, the perception of danger increases again, and among drivers with more than 10 years of driving experience, it peaks.

In this research, cadmium sulfide (CdS) and cadmium sulfide doped with 3 cc manganese (3cc Mn-CdS) nanostructures have been prepared by ultrasound-assisted method and obtained products have been used for preparation of PVC: CdS and PVP: 3 cc Mn-CdS nanocomposites as an interfacial layer of the metal-polymer-semiconductor (MPS) Schottky structures. The structural, morphological, purity and optical properties of prepared nanostructures have been investigated by XRD, SEM, EDX and UV-Vis analyzes. The XRD of CdS sample confirmed the formation of the cadmium sulfide with cubic phase and its average nanocrystallite size obtained 6 nm. EDX analysis of both samples confirmed the pure phase of the prepared nanostructures. The energy gap of the CdS and 3 cc Mn-CdS nanostructures was calculated through the energy gap diagram 4.2 eV and 3.6 eV, respectively, that these values are bigger than from its bulk value (2.5 eV) due to the quantum confinement effect.Dielectric parameters such as ɛ′, ɛ″ and tan δ, of Al /PVP: CdS/ p-Si (MPS1) and Al /PVP: 3 cc Mn-CdS / p-Si (MPS2) Schottky structures are calculated and compared using C/G-f measurements in the frequency range of 100 Hz –1 MHz.The results showed that the dielectric parameters are strong function frequency. Also, doping of cadmium sulfide nanostructures with a very small amount of manganese source leads to a decrease in the dielectric constant, conductivity, and increase in the series resistance and loss tangent of the MPS2 compared to MPS1 Schottky structure.

The purpose of this study was to investigate the effect of psychological capital and spirit of inquiry on research autonomy of postgraduate students of Chamran university of Ahvaz. The research method was descriptive correlational. the statistical population of the study included all postgraduate students of the faculties of humanities of Chamran university who were studying in the academic year 1396-97 that is total of 368 students of these, 190 people were selected by stratified sampling method as research sample. data were collected using Research autonomy questionnaire (Gravand, 2016), Psychological capital (Lutans et al., 2007) and Spirit of inquiry (Sherzad, 2012). data were analyzed by SPSS-21 software using multiple regression. The results of regression analysis showed that among the subscales of psychological capital, two subscales of resiliency and self-efficacy subscales were able to influence research autonomy. in addition, among the subscales of the spirit of inquiry, two subscales of perseverance and the curiosity subscale were able to influence research autonomy. Therefore, it is necessary to nurture and enhance resilience, self-efficacy, perseverance, and curiosity as effective factors in enhancing students' autonomy and research spirit, to consider the relevant professors, authorities, and policy makers and provide context for the realizing of these traits in educational settings.

The present study was conducted with the aim of constructing and investigating the factor structure of students' research engagement questionnaire. The research method was survey and the statistical population includes all of the postgraduate students of humanities faculty (Literature and Humanities, Islamic Theology and Science, Sport Sciences, Education and Psychology, Administrative and Economic Sciences) at Ferdowsi University of Mashhad (N=3199). Using Cochran formula, the sample size was estimated to be 343 student. The participants were selected by stratified random sampling. The theoretical model Linnenbrink and Pintrich (2002) was determined as the basis of scale construction. This model includes three components of cognitive, emotional, and leadership engagement. SPSS and AMOS software are used for data analysis. Content validity and confirmatory factor analysis were used to determine the validity of the questionnaire and Cronbach's alpha coefficient to check the reliability. The results showed that the alpha coefficient of the questionnaire was 0.89 and for cognitive (0.80), emotional (0.73) and behavioral (0.76). Content validity of the questionnaire was confirmed by 8 experts of Ferdowsi University of Mashhad (based on CVI) and inappropriate items were removed. Goodness indicators confirmed the fit of the model. According to the research results the research engagement questionnaire had good internal consistency and validity and this questionnaire can be used in research.

In this research, the effectiveness of installing night lighting in rural roads was evaluated. To this end, a number of rural roads of Ilam province have been selected. Two axes have been selected as the counter group and two axes as the comparison group. Crash data of four years has been collected. The collected data is analyzed according to before and after study with comparison group for studying crash reduction and benefit/cost method for economic analysis. For accurately estimating the effectiveness, the predicted crashes on improved and comparison sites were used. These predictions were done using the prediction model of crashes in rural two-way roads, and then the results were calibrated for local conditions using the crash modification factor related to lighting installation and also the model calibration method. By applying different stages of the method, the results show a 28% reduction in the frequency of overnight crashes after lighting installation. The statistical significance test indicates the accuracy of the result at 90% confidence level. The results demonstrate an acceptable effectiveness of lighting installation in reduce overnight crashes. The results of the economic evaluation of lighting installation in this study indicate that lighting installing has been successful in improving safety. The ratio of the benefit to the total cost of lighting installing on two counter sites is 1700 to 1. This value indicates that the benefits gained in Rial value are much higher than the annual costs of lighting installation during a 15-year period and about 1700 times.

One of the intersection safety analysis methods is creating crash prediction models using the negative binomial and Poisson regression models. However, the use of negative binomial regression is preferable due to its more data dispersion. But, the research evaluates both models at first for modeling urban intersections crashes. After testing the models by criteria of Akaike information, deviation and log-likelihood, the negative binomial regression model showed a better fit and was chosen as the better model. For modeling, the data of a 5-year period of crashes occurred at the three leg intersections of Boroujerd city has been used. The input variables of the model were selected after a significance evaluation test. These variables included the number of passing lanes, the number of right turn with traffic island lanes and the skew angle. After selecting the variables, the accuracy of the model was also studied. To validate the model, the criteria of R2, root mean square error, mean absolute error, and mean absolute percentage error were used. After evaluating the model accuracy in the prediction of accidents, it was found that the model provides acceptable results for evaluating crashes, but the results are not very accurate for predicting them (R2 = 0.52). The R2 value for the model shows that the predictions will not be precise enough, but reasonable predictions can still be provided.

Cycle of scientific research related to self-regulation skills and participation in research requires planning, monitoring and reflection. The aim of this study was to investigate of research self-regulation of post graduate students. The research method was descriptive. The statistical population included all postgraduate students of Ferdowsi university of Mashhad. 275 students were selected from the mentioned population by quota sampling method and answered the research self-regulated questionnaire. The questionnaire was developed based on Zimmermann's self-regulation theory (2002) and its content validity was confirmed by the expert judgment of six psychology and education scholars. Principal component analysis with varimax rotation revealed four factors that explained 41.90% of the variance of the research self-regulation questionnaire. Cronbach's alpha coefficients used for research self-regulation questionnaire (0.93) and motivational beliefs (0.87), research resource management (0.84), Monitoring and Self-reflection (0.84), and Forethought (0.83).The results showed that there was no significant difference between the degrees of education in self-regulation, but there was a significant difference between educational groups that the mean of motivational beliefs and resource management factors of the students of the humanities was higher than the non-human sciences students. Therefore, according to the findings of this study, improving student performance requires teachers’ attention and training, academic curriculum to research self-regulation.

Emotions are intimately involved in virtually every aspect of the teaching and learning process and good teaching is charged with positive emotions. Therefore; an understanding of the nature of emotions within the educational context is essential. This study aimed to investigate the Psychometric Properties of the emotions in the teaching Inventory of Trigwell (2012). The research method was descriptive-correlative. Teachers of Ferdowsi University of Mashhad were the research population. The required sample size was determined 280 based on the Cochran formula and participants were selected by the relative class sampling method. The Content Validity of inventory was evaluated by 5 experts based on the CVI Index. The validity was determined by confirmatory factor analysis and the reliability of ETI was confirmed by internal consistency (Cochran`s alpha) and test-retest method. The goodness of fit indexes was confirmed by confirmatory factor analysis (CFA). Also, the alpha coefficient for total size was 0/89 and for subscales was from 0/73 to 0/84. Hence, Results showed that Emotions in the teaching Inventory had acceptable psychometric properties in the sample of university teachers and can be used as a valid scale in studies related to the teaching emotions.

In this paper, the effect of the material and distance of the substrate on the characteristics of gamma alumina nanopowder coated by plasma spray method are investigated. For this purpose alumina nanopowder were coated on the two types of stainless steel and Pyrex glass substrates using a plasma torch. Morphological characteristics of the prepared nanolayer are studied by investigating the scanning electron microscope patterns. Also, the structure and phase changes of deposited alumina are investigated by X-ray diffraction spectrum. The results of this study show that the amount of particles deposition on the steel substrate is more than the glass case. Also, it is shown that by increasing the substrate distance, the amount of particle deposition is decreased for substrates. There is one optimum distance for substrate position with respect to the nozzle exit of the torch for produce and suitable coating and its control. One important result of this experimental study is the phase transfer of alumina from gamma to alpha due to the high temperature of the plasma torch

In this paper, a new spherical quantum dot is proposed to management and enhancement of third order nonlinear optical susceptibility of quadratic electro optic effect. This nanostructure is containing defective shell surrounding with two well. The size of quantum dot, thickness, position and potential of defect have a significant effect on third order optical susceptibility. By numerically solving of Schrödinger equation in the effective mass approximation the third order nonlinear optical susceptibility were calculated. The results are shown that with increasing of dot size the third order nonlinear optical susceptibility is increased. Also, with increasing of defect shell thickness the third order nonlinear optical susceptibility is increased and resonance wavelength is red shifted. The most value of third order optical susceptibility is available when in the symmetric condition of defect position, the defect potential becomes equal to the barrier potential.

The purpose of this study was to investigate the simple and multiple relationship between constructive environments with the Research Spirit of Graduate Students of Ferdowsi University of Mashhad. The research method was descriptive and correlational and population (475) students of the faculty of Education and Psychology, Ferdowsi University of Mashhad, 135 of students (99 females and 36 males) were selected by Stratified random sampling based on Cochran formula. Instrument were included constructivism environments questionnaire and Research spirit. The results of Pearson correlation coefficient showed that there was a positive and significant relationship between the scale of constructivism environments and all the sub-components of the research Spirit, except for the sub-components of emphasis on previous knowledge. In addition, simple regression analysis showed that through constructivist environments, could predicted Research Spirit . Among the sub-components of constructivist environments, the three sub-components of the facilitator's role, the Formative assessment, and attention to different perspectives were able to predict the Research Spirit. Therefore, it is imperative that university professors take into account the constructivist approach Teachings to improve the student's spirit of research and, moreover, facilitate the flow of education and research rather than the transfer of information.

In addition to Intelligence and Talent, other variables such as College student`s achievement task value improved their academic performance and achievement. the aim of this study was to investigate Validity and Reliability of the Achievement Task Value Scale. The research method was descriptive-correlative. The population was graduate students of Ferdowsi university of Mashhad in 2015-2016 year. The required sample size was determined 306 based on Cochran formula, and participants were selected by multi-stage Cluster Sampling among five Colleges. The Achievement Task Value Scale (ATVS) of Lou et al (2012) were completed by participants. The reliability of ATVS was confirmed by Internal Consistency (Cochran`s alpha). The validity was determined by Content validity, Exploratory and Confirmatory factor analysis. Results showed that alpha coefficient for total size was 0/94 and for subscales was from 0/77 to 0/87. The analysis of principle components with Varimax Rotation showed that eigenvalue of 4 factors are considerable which explains 50/78 percent of the total variance. The goodness of fit indexes was confirmed by confirmatory factor analysis (CFA). Hence, ATVS has a good internal consistency and sufficient validity in the sample of Iranian college students.

Context: Emotions plays a major role in the educational environment so Scale to measure teachers emotions is noteworthy and significant subject.
aim: The aim of this research is to examine Validity and Reliability of TEI in Mashhad.
The research method was descriptive-correlative. The required sample size was determined 023 based on Cochran formula, and participants were selected by random Cluster method. The Teacher Emotion Inventory (TEI) of Chen (2016), positive and negative affect scale (PANAS; Watson, Clark and Tellegen) (1988) were completed by participants at the same time. Primary teachers were selected by multi-stage random sampling. Teacher Emotion Inventory and positive and negative scale were tested. The reliability of TEI was confirmed by internal consistency (Cochran`s alpha). The validity was determined by content validity, convergent validity, exploratory and confirmatory factor analysis.
Findings: Results showed that alpha coefficient for total size was 0/88 and for subscales was from 0/74 to 0/88. The correlation coefficient between Teacher Emotion Inventory and PANAS for convergent validity was 0/41. The analysis of principle components with Varimax Rotation showed that eigenvalue of 5 factors are considerable which explains 62/49 percent of the total variance. The goodness of fit indexes was confirmed by confirmatory factor analysis (CFA).
Hence, TEI has a good internal consistency and sufficient validity in the sample of Iranian teachers.

Discovery of new drugs and study of their side effects has been an important research field in recent years. Because of direct effect of the pharmaceutical products on human health usually the drug design projects are challenging and technically demanding. The incorporation of computer simulations into drug design projects is one of the best ways to optimize drugs' potency. In this approach, researchers try to find the best interaction between protein structure and drug in a virtual environment; this procedure is called "molecular docking". The molecular docking problem can be considered as a search problem. The search space in this problem is defined with all possible protein-ligand interactions and the best interaction is the solution of problem. In this paper, a new approach for finding the best interaction is proposed. The proposed method is based on opposition based differential evolution algorithm. Also the proposed method is enhanced by a local search algorithm and a pseudo-elitism operator. Like other metaheuristic algorithms, our method uses a population of possible solution and AutoDock scoring function is used to evaluate each vector in the population. Six different protein-ligand complexes are used to verify the efficiency of the proposed algorithm. The experimental results show that the proposed algorithm is more robust and reliable than other algorithms such as simulated annealing and Lamarckian genetic algorithm.