Parseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Modeling of Pollutants Emission from Asphalt Plant and Crusher Devices of Road Construction Projects (Case study: Sarab – Bostanabad Road)Modeling of Pollutants Emission from Asphalt Plant and Crusher Devices of Road Construction Projects (Case study: Sarab – Bostanabad Road)3133324245FAJournal Article20140116Asphalt plants are a major part of construction activities. Asphalt factories produce pollution and degradation of the environment. Most of contaminants are produced by crushing operations and hot asphalt production processes. Derived pollutants are carbon monoxide, nitrogen oxides, volatile organic compounds, sulfur dioxide and suspended particles. In this study, by use of emission factors proposed by the Environmental Protection Agency, United States of America, the amount of pollutants produced was calculated. Then by using AERMOD Model and AERMOD, distribution patterns of these pollutants in the area around the factory for any emissions above for the mean duration of 1, 3, 8 and 24 hours, and period of 1 and 12 months in both scale regional (range 20 20 km squares) and local (range 1 1 km square) were modeled. The amount of these pollutants was then compared with the clean air standards and the EPA's. Comparisons show that production of carbon monoxide and oxides of nitrogen emissions are lower than the national clean air standards and EPA's. The maximum amount of sulfur dioxide emissions, more than the country’s clean air standards, but the maximum amount of this pollutant is less than the EPA standard and maximum particles produced in both controlled and uncontrolled for the average time of twenty-four hours and one year, respectively, about 90 and 287 times greater than the nations clean air standards. Also comparison of maximum concentration for the 24-hour average with the EPA standard shows that the concentration of the pollutant is about 30 times greater than the standard.Asphalt plants are a major part of construction activities. Asphalt factories produce pollution and degradation of the environment. Most of contaminants are produced by crushing operations and hot asphalt production processes. Derived pollutants are carbon monoxide, nitrogen oxides, volatile organic compounds, sulfur dioxide and suspended particles. In this study, by use of emission factors proposed by the Environmental Protection Agency, United States of America, the amount of pollutants produced was calculated. Then by using AERMOD Model and AERMOD, distribution patterns of these pollutants in the area around the factory for any emissions above for the mean duration of 1, 3, 8 and 24 hours, and period of 1 and 12 months in both scale regional (range 20 20 km squares) and local (range 1 1 km square) were modeled. The amount of these pollutants was then compared with the clean air standards and the EPA's. Comparisons show that production of carbon monoxide and oxides of nitrogen emissions are lower than the national clean air standards and EPA's. The maximum amount of sulfur dioxide emissions, more than the country’s clean air standards, but the maximum amount of this pollutant is less than the EPA standard and maximum particles produced in both controlled and uncontrolled for the average time of twenty-four hours and one year, respectively, about 90 and 287 times greater than the nations clean air standards. Also comparison of maximum concentration for the 24-hour average with the EPA standard shows that the concentration of the pollutant is about 30 times greater than the standard.https://jte.sinaweb.net/article_4245_e546594ad40b116388b50d48c6955f2b.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Traffic Signs Detection and Recognition by Using a Method Based on Attention Mechanism and Classical and Support Vector Machine ClassifierTraffic Signs Detection and Recognition by Using a Method Based on Attention Mechanism and Classical and Support Vector Machine Classifier3333444247FAJournal Article20140116Creation and developing of intelligent systems in transportation field, is one of the major issues in recent years. Detection and recognition are two main phases for traffic sign identification. Researchers have proposed different methods for implementation of these stages. This paper has presented a method for localization, detection and recognition of military traffic signs using a method based on attention mechanism and saliency toolbox. Probability of traffic signs presence in the images that are taken from traffic scenes is determined and salient regions in form of saliency maps were extracted. As traffic signs are distinctive because of their special shape and color, they would be detected as salient regions. In the next step, for traffic signs recognition and classification, traffic signs images were divided into several groups based on their types and SIFT feature extraction algorithm were applied for keypoints extraction. A procedure was proposed to create histograms for showing signs' feature vectors for both test and train images. Traffic signs were recognized and classified by comparing of test and train histograms. Classical classifier "K nearest neighbor" with different parameters such as: (Euclidean, x2, Manhattan) and Support Vector Machine (SVM) were used for classification. In proposed method, traffic signs detection is implemented without using an extra preprocessing methods and the result was satisfactory. In spite of the variety of traffic signs images used in each category, the recognition rate is appropriate and because of using SIFT, proposed method is scale and rotation invariant and was stable to view point and illumination changes.Creation and developing of intelligent systems in transportation field, is one of the major issues in recent years. Detection and recognition are two main phases for traffic sign identification. Researchers have proposed different methods for implementation of these stages. This paper has presented a method for localization, detection and recognition of military traffic signs using a method based on attention mechanism and saliency toolbox. Probability of traffic signs presence in the images that are taken from traffic scenes is determined and salient regions in form of saliency maps were extracted. As traffic signs are distinctive because of their special shape and color, they would be detected as salient regions. In the next step, for traffic signs recognition and classification, traffic signs images were divided into several groups based on their types and SIFT feature extraction algorithm were applied for keypoints extraction. A procedure was proposed to create histograms for showing signs' feature vectors for both test and train images. Traffic signs were recognized and classified by comparing of test and train histograms. Classical classifier "K nearest neighbor" with different parameters such as: (Euclidean, x2, Manhattan) and Support Vector Machine (SVM) were used for classification. In proposed method, traffic signs detection is implemented without using an extra preprocessing methods and the result was satisfactory. In spite of the variety of traffic signs images used in each category, the recognition rate is appropriate and because of using SIFT, proposed method is scale and rotation invariant and was stable to view point and illumination changes.https://jte.sinaweb.net/article_4247_f40ee694989b3e2161be989e7b9907fc.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Simulation of Circumferential air flow around Parsi Passenger Train under the influence of CrosswindsSimulation of Circumferential air flow around Parsi Passenger Train under the influence of Crosswinds3453644248FAJournal Article20140116Compared to the past, derailment prevention for a majority of railway machineries is now a more important task. Crosswinds are amongst the reasons for the derailment of the railway vehicles. Combination of the moving train and the turbulent transient flow of air causes complexity in the air flow domain. This can expose the rail vehicle to sever instability and increases the oscillations in the resultant aerodynamic forces and momentums. Interaction between such loads and the vehicle dynamics can cause instability problems. This can eventually lead to the derailment of the vehicle. On the other hand, to comply with the never ending demand for increasing the speed of travel, lighter materials are used in the structure of the railway vehicles. Combination of the lightweight and the increased speed of travel adds to the anxiety about the stability of the train. Such anxieties amplify especially when the vehicle is subjected to crosswinds.
This paper deals with the numerical simulation of the air flow surrounding the moving railway vehicle (Parsi coach) under the influence of crosswinds. Computational fluid dynamic engineering software is used. The aerodynamic forces and momentums for a variety of deviation angles and conditions of turbulence are calculated. The pattern for the flow of air around the vehicle and the pressure distribution on the vehicle surface are also calculated. Effects of the relative distance between the vehicles are also investigated. The most appropriate and practical distances between the vehicles are suggested. It is observed that doubling the speed of air that is directed at a yaw angle of 8 degrees, causes an increase of 4-45% in the corresponding aerodynamic coefficients. Compared to the past, derailment prevention for a majority of railway machineries is now a more important task. Crosswinds are amongst the reasons for the derailment of the railway vehicles. Combination of the moving train and the turbulent transient flow of air causes complexity in the air flow domain. This can expose the rail vehicle to sever instability and increases the oscillations in the resultant aerodynamic forces and momentums. Interaction between such loads and the vehicle dynamics can cause instability problems. This can eventually lead to the derailment of the vehicle. On the other hand, to comply with the never ending demand for increasing the speed of travel, lighter materials are used in the structure of the railway vehicles. Combination of the lightweight and the increased speed of travel adds to the anxiety about the stability of the train. Such anxieties amplify especially when the vehicle is subjected to crosswinds.
This paper deals with the numerical simulation of the air flow surrounding the moving railway vehicle (Parsi coach) under the influence of crosswinds. Computational fluid dynamic engineering software is used. The aerodynamic forces and momentums for a variety of deviation angles and conditions of turbulence are calculated. The pattern for the flow of air around the vehicle and the pressure distribution on the vehicle surface are also calculated. Effects of the relative distance between the vehicles are also investigated. The most appropriate and practical distances between the vehicles are suggested. It is observed that doubling the speed of air that is directed at a yaw angle of 8 degrees, causes an increase of 4-45% in the corresponding aerodynamic coefficients. https://jte.sinaweb.net/article_4248_5f245ebebce62ddcfacd1b6292c69392.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Effects of Abutment’s Modeling and Assignment of Plastic Hinges’ Types on Seismic Response of Reinforced Concrete Highway BridgesEffects of Abutment’s Modeling and Assignment of Plastic Hinges’ Types on Seismic Response of Reinforced Concrete Highway Bridges3653884249FAJournal Article20140116In seismic analysis and modeling of bridges, some assumptions are usually considered to simplify the analyses. Sometimes, these simplifications will cause some changes in seismic response of bridges. One of the important cases in this category is simplification of abutment’s modeling and assignment of different types of plastic hinges. Using simple and complex models of abutment in bridges is always an important factor in design and seismic response of bridges. Bridges with simple spans and continuous slab are commonly used in Iran. Therefore, the effects of three types of abutment models and plastic hinges on six bridges with various lengths and heights are analyzed. The bridges have the span of 20m and 5.3-10m heights and have been studied with 3D models. Then, analyses are accomplished with modal, pushover and study of performance point of bridges using ATC-40 method. In this paper, abutments have been analyzed with roller, simple and complete types of modeling based on laboratory results. Simple modeling considers neoprene behavior and complete modeling is composed of neoprene, shear key, end wall and wing wall specifications. Results have been presented as mode shapes, maximum base shear and the performance level in the direction of longitudinal, transverse and the angle of 45° according to the principle direction. The difference between results is increased for bridges up to 80m total length. Therefore, in seismic analysis, the connivance of nonlinear behavior of abutment element will cause notable errors in results. However, for longer bridges the responses are too closed with consideration of three models. According to this fact that the studied bridges are the commonly used bridges in Iran, results of this study are applicable for designing, modeling and seismic analysis of bridges with simple spans and continuous slab.In seismic analysis and modeling of bridges, some assumptions are usually considered to simplify the analyses. Sometimes, these simplifications will cause some changes in seismic response of bridges. One of the important cases in this category is simplification of abutment’s modeling and assignment of different types of plastic hinges. Using simple and complex models of abutment in bridges is always an important factor in design and seismic response of bridges. Bridges with simple spans and continuous slab are commonly used in Iran. Therefore, the effects of three types of abutment models and plastic hinges on six bridges with various lengths and heights are analyzed. The bridges have the span of 20m and 5.3-10m heights and have been studied with 3D models. Then, analyses are accomplished with modal, pushover and study of performance point of bridges using ATC-40 method. In this paper, abutments have been analyzed with roller, simple and complete types of modeling based on laboratory results. Simple modeling considers neoprene behavior and complete modeling is composed of neoprene, shear key, end wall and wing wall specifications. Results have been presented as mode shapes, maximum base shear and the performance level in the direction of longitudinal, transverse and the angle of 45° according to the principle direction. The difference between results is increased for bridges up to 80m total length. Therefore, in seismic analysis, the connivance of nonlinear behavior of abutment element will cause notable errors in results. However, for longer bridges the responses are too closed with consideration of three models. According to this fact that the studied bridges are the commonly used bridges in Iran, results of this study are applicable for designing, modeling and seismic analysis of bridges with simple spans and continuous slab.https://jte.sinaweb.net/article_4249_8c26d2fad09dc76f3ff36b6ea752b0e1.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Estimating the Operating Cost Excesses for Iran Air CompanyEstimating the Operating Cost Excesses for Iran Air Company3894064250FAJournal Article20140116The purpose of this study is to estimate the operating cost excess and its components for Iran Air Company using a new non-radial inefficiency measurement method. To this end a dataset of flights for 10 domestic routes over the period 2006-2008 were utilized. The findings of this study show that there is a considerable potential operating cost saving for Iran Air Company over the sampled aircraft-routes. Considering each input excesses separately provides more evidence of such a potential improvement. The results indicate that the largest cost saving for inefficient aircraft-routes can be achieved by using fuel, labor and maintenance more efficiently. Overall, and on average, fuel, labor and maintenance costs are the main sources of the weak performance for Iran Air Company by the relative costs excesses of 56%, 48% and 40%, respectively. More precisely, for Iran Air optimizing fuel consumption, labor and maintenance costs should have the high priorities in the path of performance improvement.The purpose of this study is to estimate the operating cost excess and its components for Iran Air Company using a new non-radial inefficiency measurement method. To this end a dataset of flights for 10 domestic routes over the period 2006-2008 were utilized. The findings of this study show that there is a considerable potential operating cost saving for Iran Air Company over the sampled aircraft-routes. Considering each input excesses separately provides more evidence of such a potential improvement. The results indicate that the largest cost saving for inefficient aircraft-routes can be achieved by using fuel, labor and maintenance more efficiently. Overall, and on average, fuel, labor and maintenance costs are the main sources of the weak performance for Iran Air Company by the relative costs excesses of 56%, 48% and 40%, respectively. More precisely, for Iran Air optimizing fuel consumption, labor and maintenance costs should have the high priorities in the path of performance improvement.https://jte.sinaweb.net/article_4250_fcac695db02687ffb7955b66a43fe6e6.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Urban Environmental Transportation Management of Arak City by GIS_ Based Modeling for Fuel Consumption Reducing in the Best Route FindingUrban Environmental Transportation Management of Arak City by GIS_ Based Modeling for Fuel Consumption Reducing in the Best Route Finding4074184251FAJournal Article20140116
With respect to reducing energy resources in the world, it is required to pay more attention to environmental management of energy consumption. Urban transportation is an important area in the field of energy. Urban activities are considerably concerned in the environmental management. There are two overall objectives in this study:
Development of a GIS model with acceptable accuracy, to plan appropriate locations for main transportation destinations
Development of urban transportation network to address one issue- fuel consumption.
Arak (a developing city in Iran) has been chosen as the case study. Methodology of this study helps to select suitable sites for development of urban transportation network and main destinations. GIS as a powerful tool is applied for layers overlaying and interpretation of several scenarios. Developed GIS model can be applied for planning of urban transportation networks and main transportation destinations. Based on the fuel consumption parameters, some suitability maps are produced. These maps show there are non-suitable zones for most of main destinations. This research has successfully managed development of a scientific approach for current and future model development. This approach can be employed in transportation planning and main destinations suitability assessment at both the local and national structure plan levels. The results focus on the approaches such as road type change and location changes of the main destination landuses to reduce fuel consumption.
With respect to reducing energy resources in the world, it is required to pay more attention to environmental management of energy consumption. Urban transportation is an important area in the field of energy. Urban activities are considerably concerned in the environmental management. There are two overall objectives in this study:
Development of a GIS model with acceptable accuracy, to plan appropriate locations for main transportation destinations
Development of urban transportation network to address one issue- fuel consumption.
Arak (a developing city in Iran) has been chosen as the case study. Methodology of this study helps to select suitable sites for development of urban transportation network and main destinations. GIS as a powerful tool is applied for layers overlaying and interpretation of several scenarios. Developed GIS model can be applied for planning of urban transportation networks and main transportation destinations. Based on the fuel consumption parameters, some suitability maps are produced. These maps show there are non-suitable zones for most of main destinations. This research has successfully managed development of a scientific approach for current and future model development. This approach can be employed in transportation planning and main destinations suitability assessment at both the local and national structure plan levels. The results focus on the approaches such as road type change and location changes of the main destination landuses to reduce fuel consumption. https://jte.sinaweb.net/article_4251_608b30e45f4b60adb254a8127a6da8ef.pdfParseh Designers Transportation Research InstituteQuarterly Journal of Transportation Engineering2008-65984420130622Research Note
Road Safety Performance Evaluation, Benchmarking and Target Setting by Data Envelopment AnalysisResearch Note
Road Safety Performance Evaluation, Benchmarking and Target Setting by Data Envelopment Analysis4194284252FAJournal Article20140116In this paper, analysis outputs are illustrated in two distinct stages as follows: The DEA outputs consisting of the indices that declare road safety condition in a region under study (an inverse criterion of the risk indices), and the single relative efficiency indicator in each region which best indicates the performance revenue attributed to the implemented measures. The analysis outputs (road fatality risks) are stated regarding implementation of road safety countermeasures that their great magnitude is expected to result in less road crashes and casualties. The efficiency index depends on the level of the road safety measures applied. Estimating the relative inefficiency values among the different provinces is performed applying the Data Envelopment Analysis (DEA) method. In this research, an inefficiency index is used as a criterion to evaluate the previous performances of road safety agencies. Using a dual model of the main DEA model for each DMU, a target setting task can be conducted by identifying the benchmarks as the leading entities. Two restricting subjects and relevant solutions have been proposed. The first is the concern about efficient units or benchmarks who have not found any unit to follow as a better performing one. Somehow, the benchmarks can also find a better situation in a special analytical context. The second issue relates to the two-year data comparison in a same province and the related debates.In this paper, analysis outputs are illustrated in two distinct stages as follows: The DEA outputs consisting of the indices that declare road safety condition in a region under study (an inverse criterion of the risk indices), and the single relative efficiency indicator in each region which best indicates the performance revenue attributed to the implemented measures. The analysis outputs (road fatality risks) are stated regarding implementation of road safety countermeasures that their great magnitude is expected to result in less road crashes and casualties. The efficiency index depends on the level of the road safety measures applied. Estimating the relative inefficiency values among the different provinces is performed applying the Data Envelopment Analysis (DEA) method. In this research, an inefficiency index is used as a criterion to evaluate the previous performances of road safety agencies. Using a dual model of the main DEA model for each DMU, a target setting task can be conducted by identifying the benchmarks as the leading entities. Two restricting subjects and relevant solutions have been proposed. The first is the concern about efficient units or benchmarks who have not found any unit to follow as a better performing one. Somehow, the benchmarks can also find a better situation in a special analytical context. The second issue relates to the two-year data comparison in a same province and the related debates.https://jte.sinaweb.net/article_4252_7bfa32686d200c64cb46de03ac2eac0d.pdf