Nagmeh Neisany Samany; Mahmoud Reza Delavar; Mohammad Reza Malek
Abstract
Navigation is one of the most important daily activities of individuals in an urban environment. The spatial information systems of the user guidance are the most common services which guide people to navigate the various routes with different goals.The main challenge of such systems is providing context-aware ...
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Navigation is one of the most important daily activities of individuals in an urban environment. The spatial information systems of the user guidance are the most common services which guide people to navigate the various routes with different goals.The main challenge of such systems is providing context-aware navigation information. The location, time,and the identifier of the individual person are among the primary contexts and the other related contexts are modeled based on these contexts. The present paper attempts to model the spatial-temporal communication of the moving user based on the identifier of the individuals. So that it covers all spatial communications (topologic, metric and directional) in time dimension andtakes the characteristics of the user and the related contexts into consideration. In this regard, the proposed model utilizedthe advantages of Allen’s Multi-Interval Algebra (MIA) and dynamic Voronoi-based Continuous Range Query (VCRQ), and introduceda new method by following the large calculus principles and the existing customization methods. The designed model (MIA25) was implemented in a software applicable in mobile systems. The evaluation of the implemented model in the tourist’s navigation scenariointhe regions 3, 6, and 11 of Tehran municipality was carried out based on 3 parameters of accuracy, runtimeand users’ satisfaction. These three regions were selected as the case study area. In order to test the accuracy of the model, the designed software was iterated 100 times in three different routes in the study area by three different tourists at three time intervals with two different average speed. Then, the recognition of each one of the textures existing on the way, was examined by the one-way binomial approximationwith 95% of confidence level over 100 iterations. Also, two indices of correctness and recall were used to evaluate the recognition of the textures through the entire route. The results of implementation and evaluation of the model based on three parameters of accuracy, runtime and users’ satisfaction demonstrate the efficiency of the proposed model in an urban context-aware navigation system.
Fatemeh Mohammadyari; Hamidreza Pourkhabaz; Morteza Tavakoli; Hossein Aghdar
Abstract
Knowledge of qualitative and quantitative characteristics of changes are extremely important in environmental planning, land use planning and sustainable development. Currently, using vegetation maps is one of the key factors in data production for macro and micro planning. In this research, information ...
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Knowledge of qualitative and quantitative characteristics of changes are extremely important in environmental planning, land use planning and sustainable development. Currently, using vegetation maps is one of the key factors in data production for macro and micro planning. In this research, information of Landsat ETM + and OLI sensors were used to display the temporal and spatial changes of vegetation in Behbahan city in 1999 and 2013 and the value of NDVI index was calculated for two years. In order to evaluate the quality changes of vegetation, the numerical values of the index were classified into 4 classes of different lush green vegetation including land with excellent, very good, good, and poor coverage. Then, the changes were determined using CROSSTAB. The results showed that the qualitative and quantitative changes in vegetation for the study area have been extensive over 14 years, so that, the area of lands with excellent, very good and poor coverage has increased and the area of landswith good coverage, has decreased. The greatest increase in areashas occurred in lands with excellent coverage, so that, it has increased from 5069.76 hectares (ha) in 1999 to 7735.5 ha in 2013. Also, the highestdecrease in areas has occurred in lands with good coverage thathas reached from 34061.4 ha to 27434.43 ha. Finally, the regression equation was obtained to show better relationship between the two parameters of vegetation and temperature. The results confirmed the point that the areas covered with vegetation have lower temperature and vegetation has cooling effects on the surrounding. Therefore, the degradationof the region’s vegetationwill be followed by the warming of the city and many other environmental consequences.
Samad Shadfar
Abstract
One of the types of environmental hazards that causes the destruction of agricultural lands, rangelands and Infrastructure in many parts of the country is gully erosion. In this research, fuzzy logic operators were used with the aim of determining the different hazard zones,obtaining the area of each ...
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One of the types of environmental hazards that causes the destruction of agricultural lands, rangelands and Infrastructure in many parts of the country is gully erosion. In this research, fuzzy logic operators were used with the aim of determining the different hazard zones,obtaining the area of each one of them, and presenting the map of the gully erosion hazard in Troud watershed. In order to achieve this goal, satellite imagery, interpretation of 1:20000 scale aerial photos, 1:50000 scale topographic maps, 1:100000 scale geological maps, field studies and ArcGIS software have been used as the main research tools. To do this, at first, some of the effective variables which had more important roles in the formation and development of gully erosion, as well as the areas with gully erosion, were identified. In the next stage, the effective factor classes were weighted and the gully erosion map was prepared using fuzzy operators including fuzzy algebraic sum, fuzzy multiplication, fuzzy gamma 0.5 and fuzzy gamma 0.8 in the GIS environment.The results indicate that in the fuzzy algebraic summation method, 100% of the gully areas are located in very highclass, in the fuzzy algebraic multiplication, 83.29% of the gully areas are located in low class, in 0.8 fuzzy gamma method,60.93% of the gullies are located in low class and about 17 %are located in high and very high classesbut, in 0.5 fuzzy gamma method, around 1.5% of the gully areas are located in low class and about 62% are located in high and very high classes.
Haniyeh Jafari; Ali Asghar Alesheikh
Abstract
With the increase in urbanization, the surface of the Earth and its climate have changed.These changes resulted in more frequent inundation(flooding) problems in urban areas. Prediction and monitoring systems can act as appropriate tools for quick decision-making and taking necessary actions to deal ...
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With the increase in urbanization, the surface of the Earth and its climate have changed.These changes resulted in more frequent inundation(flooding) problems in urban areas. Prediction and monitoring systems can act as appropriate tools for quick decision-making and taking necessary actions to deal with flooding in urban areas. In this research, we developed a Web-based GIS system for the prediction and monitoring storm inundation in urban areas. This system is based on service oriented architecture and uses web processing services. The architecture of the developed system has three tiers including data tier, business logic tier, and presentation tier. Data tier includes some data which is stored as spatial web services in a distributed database. Business logic tier includes two web processing services. These web processing services are hydrological characteristics calculation service and inundation calculation service. Hydrological characteristics calculation service uses WASI algorithm to calculate flow direction as well as flow accumulation. The output of hydrological characteristics calculation service is delivered to inundation calculation service as input. Inundation calculation service uses ASIISM model for inundation calculations. The output of this service is inundated points with inundation volume, area and its depth. A central web processing service chain these services. The duty of presentation tier is to take precipitation information from the user and show the resulting maps. A part of region 22 in Tehran was chosen as the case study area. The results showed that the um of the inundation area for selected storm event is about 0.81 percent of the study area. The system used by the users and its user interface, its inundation simulation ability and its ability of inundation evaluation were evaluated by these users. Its user interface and its ability of inundation simulation have the most and the least satisfaction among users. Using standard-based spatial web services to implement the system, provided reusable services.
Marziyeh Mokarram; Saeed Negahban
Abstract
Landform is a feature of land or landscape, the establishment of which is formed by natural processes that can be described and defined by index feature, and if detected, the landformprovidesinformation aboutits own structure along with its composition, texture, or integration. The existence of landforms ...
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Landform is a feature of land or landscape, the establishment of which is formed by natural processes that can be described and defined by index feature, and if detected, the landformprovidesinformation aboutits own structure along with its composition, texture, or integration. The existence of landforms variety and their diversity are mainly controlled by the change inthe shape and the position of the Earth. Therefore, the classification and identification of different areas with regard to their morphological characteristics is essential. This research attempts to classify different landforms in the southern city of Darab. This research is Descriptive-analytical based on quantitative, field, software and modeling methods in which the Topographic Position Index (TPI) method was used for the identification and classification of landforms of the study area. The input data in this model includes slope, transverse curvature, minimum and maximum curvatures. The results of the morphological classification of the study region showed that the region includes 10 types of landform (waterway, valleys of middle waterways, high drains, upstream, u-shaped valleys, small plains, open slopes, upper slopes, elevated ridges, middle slope ridges, mountain peaks). Most of the landform types in the study area are related to the waterways (32/19 %) and then, the peaks (25/36 %).
Esmaeil Nasrabadi
Abstract
Analyzing the changes in the characteristics of daily precipitationis very important in water resources planning and cultivation patterns. In this research, the changes of the most fitting frequency distribution and its parameters over time are investigated. To this end,thenetworked daily precipitation ...
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Analyzing the changes in the characteristics of daily precipitationis very important in water resources planning and cultivation patterns. In this research, the changes of the most fitting frequency distribution and its parameters over time are investigated. To this end,thenetworked daily precipitation data of the Middle East Aphroditeprecipitation database with a latitude and longitude of 0.25, 0.25 degreeswere used.The daily precipitation data of this database in Iran, during the period of22.03.1951 to 20.03.2007 (20453 days) was extracted using Grads software. To track the changes over time, the data was divided into two 28-year periods. The precipitation data of the first period from 22.03.1951 to 20.03.1979 was placed in an array with a dimension of 10226*2491 and the data of the second periodfrom 21.03.1979 to 20.03.2007 was placedin an array with a dimension of 10227*2491(the rows and columns represent the number of days and cells respectively).The Kolmogorov-Smirnov Goodness-of-Fit test was used to identify the most fitting distribution of rainy days. The normal and gamma type distribution functions onindividual cells of the precipitation were fitted by programming in Matlab software environment. The theoretical two- parameter and exponential gamma distribution function has been able to attain the required statistical conditions for the Goodness-of-Fit test at a 95% confidence level as the most fitting distribution in both periods.The extensive spatial and temporal changes in precipitation distribution are not confirmed as one of the components of climate change tracking. The calculation of the most fitting distribution parameters by linear torque method shows slight variations in the spatial dispersion pattern of these parameters. But, these changes do not follow a specific pattern. The mapping of the standard deviation variation indicates that in a vast part of central and western Iran, the confidence in precipitation has decreased in recent decades.
Masoud Torabi Azad; Kamran Lari; Faramarz Rostaei
Abstract
In this research, the large-scale currents have been investigated using field data of the Caspian Sea temperature, salinity and density at the stations near west of the South Caspian, related to two field patrols. The geostrophic current is created due to the balance of the gradient pressure force and ...
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In this research, the large-scale currents have been investigated using field data of the Caspian Sea temperature, salinity and density at the stations near west of the South Caspian, related to two field patrols. The geostrophic current is created due to the balance of the gradient pressure force and theCoriolisEffect, and is the major factor in the creation of large-scale currents. After analyzing the data, the speed and direction of these types of currents were calculated using satellite imagery.These images were extracted from Aviso satellite with a spatial resolution 0.25 degrees.The calculations for the five vertical sections in the westpart of the South Caspian Sea werecarried out using Excel software and the depth profile of the geostrophic currents speed was obtained speed in each of these sections.In the Southwestern part of theCaspian, the average velocity of these currents for field data was calculated to be 5.85 and 15 cm /s is for the summer and winter respectively. The direction of these currents was also obtained to be 285 in the summer and 44 in the winter. With regard to the satellite images, counterclockwise currents up to 4.5 cm/s velocities and, eastward counterclockwise currents at the velocities of 8 cm/s are observed in the summer and in the winter respectively. The value of the currents velocity (the magnitude of the vectors) indicates that the average currentsvelocity is higher in the winter. One of the reason for this is due to the difference in density caused by the increase in rivers flow rate (especially the Volga), precipitation, wind, etc.
Hadi Babapour; Mahdi Mokhtarzadeh; Mohammad Javad Valadanzoj; Mahdi Modiri
Abstract
The importance of spatial-referenceddata in all developmental and research affairs is not overlooked. Among the methods for the preparation and production of spatial data, the photogrammetry method has a unique position due to speed, cost-effectiveness and above all, the lack of need to direct human ...
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The importance of spatial-referenceddata in all developmental and research affairs is not overlooked. Among the methods for the preparation and production of spatial data, the photogrammetry method has a unique position due to speed, cost-effectiveness and above all, the lack of need to direct human presence on the site. In photogrammetric method, airborne cameras play a key role in the success and achievements of other stages, as the main means of providing input data and the first operational loop. Today, technological advances have led to the presentation of high quality digital cameras that promise the provision of the required spatial information by photogrammetric method with high accuracy, speed and efficiency. Given the emergence of new digital cameras and the variety of construction and technology used in these types of cameras, the need for their calibration is recognized as a primary requirement. Considering the high costs and executive problems with performing laboratory calibration, the use of self-calibration equations is considered as one of the most useful solutions in this field. For this purpose, in this paper, the use of Fourier equations with optimal terms derived from the genetic algorithm was proposed, and was evaluated and compared with previous models on the simulated data. Based on the results, this model is able to model multiple distortions with minimal dependency. The accuracy presented for modeling multiple distortions in simulated images of the Ultra Cam digital camerashows an about 30% improvement in modeling accuracy with the least dependency,compared with other additional parameters.
