Showing 15 results for Modeling
Mr Milad Khayat, Ms Atefeh Bosak, Dr Zahra Hejazizadeh,
Volume 0, Issue 0 (3-1921)
Abstract
Using urban growth and development modeling, it is possible to draw a development trend appropriate to the city's position according to environmental and natural factors and population attraction. The purpose of this study is to represent a model of urban development in Shushtar that can be used as a felicitous tool to analyze the complex processes of urban development. To achieve this goal, two databases consist of urban land use maps for educational, medical, habitation, etc and Landsat satellite images for major land uses such as rivers, barren areas, forests, etc were used by GIS and MATLAB software environment in three time periods 1991, 2004 and 2014. Existing urban land use maps were updated by using Landsat satellite imagery after digitization. Then the effective parameters in urban development were entered as inputs with the adaptive neuro-fuzzy inference algorithm (ANFIS). in order to evaluate the performance of the proposed method, training for 1991 and 2004 was performed. the result of urban development forecasting using the algorithm was compared with the current situation in 2014. The results are very close to reality and with an accuracy of 93.7%. The land use change map, which is the result of the change detection process, can be prepared based on multi-time remote sensing images and combined with urban user maps, and the relevant consequences examined. The use of intelligent algorithms in this research has allowed us to execute modeling with high accuracy. The results are satisfactory and this development was predicted for the coming years.
Phd Mohammad Mohammadi,
Volume 0, Issue 0 (3-1921)
Abstract
Today, energy consumption plays a decisive role in the qualitative and quantitative development of human life. One of the energy sources is in line with the development and economic prosperity as well as acquisition of climate comfort in natural gas. This source of energy supply, especially in cold areas of the country as well as to provide thermal comfort is required to proper management. Good management of this fossil energy sources is through awareness and forecasts of demand rate of that path. For this reason, demand for natural gas in Zanjan city was studied and modeled as one of the cold cities in Iran. Two groups of data (weather elements and natural gas consumption) for a period of 9 years (2013-2021) on a daily scale have been used for performing this study. CurveExpert software and regression method (regression) were used in order to modeling the demand for natural gas in the city. Based on the most graceful pattern, temperature element was selected as the only independent variable in selective pattern. Polynomial regression with a correlation coefficient of 0.94 (coefficient of determination 89.03 percent) was selected to the final model. The percentage increase in natural gas consumption per one degree decrease in temperature, from 22 to 16 degrees, the highest percentage increase and from zero to -5 degrees, the lowest percentage increase per one degree decrease in temperature. The turning point and the beginning of problems related to the lack of natural gas in Zanjan city was determined to be below minus 7 degrees.
Alireza Yousefi, Mahdiyeh Shahabinejad, Amimozafar Mini,
Volume 15, Issue 37 (9-2015)
Abstract
Agricultural sector has an important role in development of countries. One of the obstacles to development in this sector, especially in Iran is significant fragmentation of agricultural lands. The aim of this study is to assess the farmers’ willingness to participate in land consolidation project using structural equation modeling. The population of this study consists of all farmers of Meymeh County and its surrounding cities and villages and Niloofar-Abi cooperative of Vazvan city. Data were collected on a sample of 156 farmers through face-to-face interviews based on a comprehensive structured questionnaire. Before the survey, the reliability and validity of questionnaire was initially evaluated on a pre-test study respectively by using Cronbach’s alpha coefficient, expert’s judgment and Kaiser-Meyer-Olkin (KMO) criteria. The results of this study show that the most important factors on farmers' willingness to participation are crop acreage and number of plots which respectively has the greatest positive and negative effect. The awareness of the farmers about benefit of consolidation project is another factor which has significant and positive impact on farmers' willingness. Furthermore, level of farmers schooling has no significant effect.
Majid Yasoori, Seyedeh Fatemeh Emami,
Volume 18, Issue 48 (4-2018)
Abstract
The current study was conducted to investigate and explain poverty in Saravan village in Rasht city. In this research, survey method and structural equation modeling were used to present a model of based on results of the census in 2011, the number of villages in this district was 7 villages and the number of households was 4283 households. Morgan table was used to determine the sample size of the family heads living in rural areas of Saravan. Finally, 351 questionnaires were selected for family heads, which it was increased to 370 to obtain better results of the questionnaires. The results of a single sample T test indicate that the social and political indices are at good status. However, the T-value of the economic dimension is at the poverty status. The main reason for the poor status of this index is adequate consumption of fruits and vegetables in the household food plan, the inadequacy of housing space for children and the vulnerability of residential against earthquakes and accidents, and the sale of products indirectly through middlemen. It has caused respondents to consider lower scores for this index. According to the findings, the factor load of all items is confirmed in the social, economic and political dimensions.
Dr. Mostafa Karimi, Mis Fatemeh Sotoudeh, Dr. Somayeh Rafati,
Volume 18, Issue 48 (4-2018)
Abstract
Increasing CO2 emissions and consequently, air temperature causes climate anomalies which affects all the aspects of human life. The purpose of this study was to assess the temperature changes and also to predict the extreme temperatures in Gilan and Mazandaran Provinces. To do this, the SDSM statistical and dynamical model was used. As well, it was applied the Mann-Kendal graphical and statistical technique to analyze the temperature changes and its trend. In this regard, the daily temperature was obtained from Rasht, Ramsar and Babolsar synoptic stations during 1961 – 2010, and also the general circulation models data of HadCM3 and NCEP were collected from related databases. The results revealed a significant positive trend in monthly and annual minimum and maximum temperature in all three stations in the first (1961-2010) and third (1961-2040) periods. There is not a significant trend in extreme temperatures in Ramsar and maximum temperature in Rasht in the second period (2011-2040). The Mann-Kendal graphical test was used for the yearly extreme temperatures in all periods. The results showed that it was occurred both increasing trend and suddenly changes or shifts at the 95% confidence level in all stations. It is occurred the highest of changes in monthly and annual of the minimum temperature at forecasted period (2011-2040). It was predicted extreme temperature to increase about 0.1 to 1.7° C. The short time oscillations and significant positive trend occurred in both the maximum and minimum temperature shows the temperature increase and climate changes in the future. Thus it is obvious the decrease in temperature difference in warm and cold seasons.
Dr Abazar Solgi, Dr Heidar Zarei, , ,
Volume 18, Issue 50 (6-2018)
Abstract
Estimating and predicting precipitation and achieving its runoff play an important role to correct management and exploitation of basins, management of dams and reservoirs, minimizing the flood damages and droughts, and water resource management, so they are considered by hydrologists. The appropriate performance of intelligent models leads researchers to use them for predicting hydrological phenomena more and more. Therefore, in this study, the Gene Expression Programming (GEP) and Support Vector Regression (SVR) models were used to model monthly precipitation of Nahavand City. In this study, precipitation, temperature, and relative humidity data were used in a 32-year period (from 1983 to 2014). The results showed that the same and good performance of both models (R2= 0.92), but according to different evaluation criteria, GEP model showed a little better performance (RMSE= 0.0478 and 0.0486), while the running GEP model is so easier than the SVM model. Totally, it can be said that GEP model had been suitable for modeling monthly precipitation of Varayeneh station in Nahavand City. Finally, the monthly precipitation was predicted the GEP which showed a decrease in precipitation in compared with previous months.
Hossein Asakereh, Robab Razmi,
Volume 18, Issue 50 (6-2018)
Abstract
In the present study, the main aim was the spatial evaluation summer rainfall of northwest of Iran based on30 stations in northwest of Iran during 30 years of statistical period (1985-2014). An attempt, using geo-statistical modeling by ordinary least squares (OLS) and geographically weighted regression (GWR) procedures, was also made. The results represented that the GWR model with higher S2, lower residuals and lower RMSE is an optimized geo-statistical model for rainfall modeling of this area. This model can explain spatio-temporal rainfall distribution in northwest of Iran in a diversified topographical and geographical background. This model revealed that two spatial factors including elevation and slope, have the most important role in the summer rainfall behavior.Therefore Elevations in the mountainous and eastern parts of Lake Urmia, Latitude in the northern regions and slopes in the east of the region, have the most role in the spatial variations of summer precipitation in northwestern Iran.
Hossein Naserzadeh, Fariba Sayadi, Meysam Toulabi Nejad,
Volume 19, Issue 55 (12-2019)
Abstract
This research was carried out with the aim of understanding the spatial displacement of rainfall nuclei as an effective factor in the future hydrological conditions in Iran. Two types of databases were used to conduct this research. The first type of data is the monthly precipitation of 86 synoptic stations with the statistical period of 1986-1989 and the second type of predicted data from the output of the CCSM4 model under the three scenarios (RCP2.6, RCP4.5, and RCP6) from 2016 to 2036. After collecting and modeling the data, the maps were mapped to the ARCGIS environment. The results of the study showed that the terrestrial nuclei in the whole of Iran's zone in the four seasons will have changes with a negative trend in the future. The coefficient of rainfall variation in the spring, summer, autumn and winter seasons will be 61.4, 101.4, 58.9 and 55.8 percent, respectively. The results of the triple scenario study showed that the displacement of the spring core from all north north of the country to the northwest of the country is limited to the common borders of Iran, Turkey and Armenia (the Maku and Jolfa region), but in summer, the high core The northern shores and parts of the northwest of the country will be transported to the south of the country (around Khash and Saravan). In the autumn, the high-lying zone, which is located throughout the northern part of the country, will move to two distinct nuclei in the central Zagros (Dena and Zadkouh areas) and southwest Khazars (Anzali and Astara areas), and the core of winter from the central Zagros And the Caspian region will be transferred to the northwest of Kurdistan and southwest of West Azarbaijan, which will be seen in all scenarios. Another point is that, in addition to reducing the boulders, in the future, drought areas will cover more of the country.
1 Somayeh Mehrabadi,
Volume 21, Issue 60 (3-2021)
Abstract
The classical methods, also known as hard methods, are based on the accuracy of calculations, while the real world is founded on the inaccuracy of boundaries and the uncertainties, which is more consistent with soft computing methods. Each of these methods has its own strengths and weaknesses, and the hybridization theory was introduced to solve these problems. In the hybridization theory, which is also called intelligent hybrid systems, two or more single intelligent methods are combined to eliminate or rectify the shortcomings and limitations of single methods. In this study, forest degradation was modeled by employing the single-perceptron neural network and hybrid neuro-fuzzy method. For this purpose, the images from Landsat-5 TM sensor in 1999 and Landsat 8 OLI sensor in 2017 were utilized. Then, the degraded and non-degraded forest areas were sampled in 200 locations. Seven factors identified as the most effective factors in forest degradation, including the distance from the features like city, river, village, sea, and road, elevation and slope were measured for the 200 locations. The mean squared error (MSE) was used to evaluate the performance of models, which was 0.0535, 0.0704, and 0.0908 for the perceptron neural network in the Levenberg-Marquardt, Bayesian regularization, and scaled conjugate gradient algorithms, respectively. Also, the MSE value for the neuro-fuzzy model in the optimization and hybrid algorithms was 0.0190 and 0.0102, respectively. The analysis of the results showed the optimal performance of the neuro-fuzzy method both in reducing the error and in generalizing the model. Relying on the uncertainty rule, the neuro-fuzzy model provides the conditions that are closer to reality and have been more successful than the perceptron model at selecting the appropriate data.
Elias Mavedat,
Volume 21, Issue 61 (6-2021)
Abstract
An earthquake, though a natural phenomenon that can be very destructive, But urban planning and management can play an important role in the damage it poses. Today, risk analysis is one of the basic needs for planning in general and urban planning in particular. From the perspective of many researchers, urban regeneration is one of the most important issues for sustainability. It serves as a way to strengthen communities by using their capacities. From the issue of choice in the city of Ilam, Ilam is located in the Zagros zone. So that the Zagros area has the highest earthquake with magnitude 4 to 4/5 richter has. According to the necessity of this research, a combination of methods (descriptive, exploratory, surveying, and analytical). In terms of the nature of research, it has a developmental-applied approach in line with the overall objective of urban spatial management planning research from the perspective of resilience is a city of Ilam. Based on the VIKOR statistical statistic, Bootstrap and Bootstrap simulation have been used. Visio, Grafer, SPSS, MINITAB and GIS software have been used to complete the research. Results of the findings were based on Bootstrap simulation and based on the 196 cells studied, distributed among 14 urban districts; The minimum residual cell in the city of Ilam has been around 0.07 percent. Therefore, the dispersion and status of the Ilam city variables can not be confirmed at urban confidence level of 95%. Based on the VIKOR model of the 4th region, the least resiliency and the region of 2 is the highest Ilam city resilience. Also, the regression model calculations have shown that the applied model is a good predictor of the urban regression variable. Because the significance of the present study is less than 0.05.
Dr Mandana Habibi, Dr Hosein Mojtabazadeh,
Volume 21, Issue 61 (6-2021)
Abstract
A review of the history of the Islamic period reveals that concepts such as Islamic values and principles have always been one of the foundations of Islamic cities. This has made the Islamic city a space for the development of other Islamic fundamental concepts and principles. However, with the emergence of modern thinking and the emergence of numerous movements, we have seen that many of these are distorted. considering the historical background, values and factors present, district 20 in Tehran, is of no exception. In this regard, the purpose of this study is to investigate the mechanisms of how each of the factors of the Islamic city influence the perception of the inhabitants of this historical district of Tehran. To achieve this goal, a conceptual model of the research was first developed using the literature as well as the research context in which the three main physical, social and validity dimensions were considered for Islamic urban planning. Subsequently, using a questionnaire survey and its analysis by structural equation modeling, the effect of each of these factors on their indicators was put forth as the research findings. The results of the analysis indicate that the "validity" factors have the most impact on people's perception of the Islamic city, while the "social and civil" and "physical" factors are less influential.
Dr Foroogh Khazaee Nezhad, Sakine Beigi,
Volume 21, Issue 61 (6-2021)
Abstract
Today, most of the world's population lives in cities, and urbanization, as the dominant phenomenon of human life, has continued to grow. But in recent years, the lives of city dwellers have faced many problems. In recent years, urban experts are looking for a solution for these problems, in which different theories, views, approaches, and models have been proposed. One of the most important approaches is the livability that is related to sustainable development. In this study, the relationship between different indicators of livability and its nature is explained. The central part of Bojnourd city has been selected as the case study. This research is a practical, desk and field study. Structural Equation Modeling with partial least squares approach and related software were used for data analysis. The results of the research showed that although there is a significant relationship between most of the indicators studied in this study and the viability, the local participation, educational facilities, and leisure facilities have had the greatest impact on livability. It was also found that there is a significant statistical relationship between residence time and identity (P = 0.01) and duration of residence and individual participation (P = 0.08) (90% confidence level).
Rahman Zandi, Najmeh Shafiei, Ebrahim Akbari, Ali Hajizadeh Shikhanlo,
Volume 23, Issue 71 (1-2024)
Abstract
Natural parameters are one of the main determinants of the physical development of cities and settlements. In a mountainous area, the effects of these factors have become a barrier to development and can have natural hazards. In this research, it is tried to identify the optimal directions of physical development of the city of Nurabad as a relatively high region by identifying its effective factors and evaluating it. To achieve this, seven effective indicators (elevation, gradient, gradient direction, lithology, distance from the fault, distance from the waterway) were used and to assess, model, and predict areas suitable for physical development of the city from Landsat satellite imagery and Models of FUZZY-AHP and Makov and Markov's predictions have been used. So that each of the layers is fuzzy according to the fuzzy membership functions in GIS Arc 10.3 software. An analytical comparison on the appropriate areas of the city based on the critical points with the appropriate zones. Finally, the final map with the two models was classified into five classes. The results of the research showed that up to 1404 horizons of the city were developed eastwards in Although this pathway is not a suitable route, due to the existence of the main Kazeroun fault and the main waterway, the most important risk factors in the city are considered to be the best place for the development of the city of the western and southwestern regions of the region, which is 13% of the area of the basin Includes.
Mr Hamid Fakhimzade, Dr Hadi Sarvari, Dr Mohamadhadi Mahdinia, Dr Mahdi Mahmoodzade Vashan,
Volume 24, Issue 72 (6-2024)
Abstract
A city requires city brand and appropriate strategies for beneficiaries, especially tourists; hence, city development plans can affect the type of city brand orientations. Accordingly, this study was conducted to identify the effective factors to design structural equation modeling (SEM). SEM was employed to rank the factors and find the correlation between them using Forner-Larcker Matrix. This was an applied-correlational study in which, data were collected through convergent mixed methodology, library study, questionnaire, and Semi-structured interviews. Birjand was chosen as the research field and a statistical sample was chosen at descriptive statistics using purposive and snowball sampling methods. Accordingly, 19 subjects were selected from urban experts, and 381 tourists were chosen at the quantitative step using simple random sampling. findings obtained from interviews implied that some points should be considered for the city branding of Birjand. The factors include the significant militarily and academic impact of Birjand on historical aspect and service-based economy of the city, cultural capitals, and the arts that are forgetting, immigration, and implementing the development-driving plans. The research model indicated that city development plans had the highest positive effects on the landscape and mental image regarding city branding plans. Moreover, According to the correlation between components, the highest relationship was between mental image and landscape (0.66).
Dr. Mohsen Aghayari Hir, Dr. Hossein Karimzadeh, Mrs. Nahid Rahimzadeh,
Volume 24, Issue 73 (8-2024)
Abstract
Access, plays an important role in rural development as there is a meaningful relationship between rural development and access to infrastructure services. Villages that have less access to essential services, especially transport, faced with a lot of structural and socio-economic constraints, which are obstacles to sustainable rural development. The present study seeks to examine the accessibility and the factors affecting it. Accordingly, it is considered with descriptive-analytic research method. The statistical population of the study, consisted of villages in the central District of Tabriz County (52 villages) that there needed data were gathered from rural municipals. After validity and reliability of the research, in order to evaluate accessibility, we used the Dematel technique and ANP, then to assess the role of different elements in accessibility of rural areas, we used SEM in Amos software. Initial results of Rural Accessibility Survey showed that the Mayan Sefli village had the highest accessibility and the final result of the research are determining the role of factors in rural accessibility based on factors such as distance from the city, service centers and social status of the village are more effective than other factors in accessibility.
Key words: accessibility, rural services, analytical network process, structural equation modeling, Tabriz County.
