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Showing 38 results for Inequality
Volume 0, Issue 0 (12-2024)
Abstract
Aim and Introduction
This paper examines the distribution of income in Iran from 2006 to 2016 and evaluates the validity of one of the latest economic theories concerning income distribution, namely, the Econophysics Two-Class Theory of Income Distribution (EPTC).
According to this model, income distribution generally comprises two classes. The lower class of this distribution, typically representing 97 to 99% of th society, follows the exponential (thermal) Boltzmann-Gibbs distribution, primarily driven by labor income. This distribution remains stable over time and undergoes minimal fundamental changes. Conversely, the income distribution of the upper class, constituting approximately 1 to 3% of society, follows the Pareto distribution, recognized as a superthermal distribution in econophysics. Notably, this distribution exhibits high variability over time, closely mirroring fluctuations in the stock market.
For this study, a review of the theoretical literature on the statistical distribution of income is conducted, tracing its evolution from Pareto's initial attempts to the formulation of the two-class distribution of income. In the methodology section, emphasis is placed on delineating the characteristics of two Probability Density Functions (PDFs) and Complementary Cumulative Distribution Functions (CCDFs) associated with exponential and Pareto distributions. The methodology elaborates on the approach to detecting income distribution patterns within the framework of the aforementioned theory. Subsequently, in the data and findings section, an examination of the income data spanning the specified time period in Iran is undertaken. The section meticulously explores the compatibility of these data with the EPCT, offering detailed discussions on the observed patterns and their alignment with the theoretical framework. Finally, the implications of the EPCT are elucidated, and the paper's conclusions are presented in the concluding remarks section.
Methodology
In complex systems concluding big data or complex models, alternative approaches beyond conventional statistical tests may be employed to estimate distributions. Visual inspection and descriptive analysis, facilitated by histograms and distribution charts, serve as effective tools for approximating distributions without relying on statistical tests. The selection of distributions is informed by theoretical considerations that align with the underlying characteristics of the system. These alternative methods offer practicality and informativeness, particularly in scenarios where traditional statistical assumptions may not hold or when dealing with extensive and unconventional data. The present article adopts this methodological approach to analyze income distribution in Iran.
The initial step involves drawing the histogram and probability density function (PDF). The shape of the histogram guides the identification of distribution. Given the potential complexity arising from large datasets, and the ambiguity that may arise from visual inspection of merely the PDF, a Complementary Cumulative Distribution Function (CCDF) plot serves as a valuable aid. Subsequently, following the first step and the selection of candidate theoretical distributions, the CCDFs are plotted to ascertain the optimal fit with the experimental data distribution. Consequently, the combined use of PDF and CCDF serves as indispensable tools for delineating annual income distribution patterns.
The resemblance between the graphs of the PDF for both exponential and Pareto distributions on a linear-linear scale poses challenges in distinguishing between these distributions. Similarly, the CCDF curve lacks clarity on a linear-linear scale due to this similarity. However, employing a logarithmic-linear scale to plot the survival function related to the data of the lower part of society proves beneficial, as it reveals a smooth line representative of the exponential Boltzmann-Gibbs law. Similarly, plotting the survival function for the upper part of the society on a logarithmic-logarithmic scale serves to elucidate the Pareto power law. Consequently, plotting the survival function for the entire dataset on a logarithmic-logarithmic scale, as per the hypothesis of the EPTC, should unveil two distinct segments: exponential and Pareto.
Findings
The data utilized in this study were derived from the raw tables pertaining to the household expenditure-income (budget) plan, annually published by the Statistical Center of Iran. Specifically focusing on data sourced from the urban population, which constituted approximately three-quarters of the total population during the study period. Data preparation commenced with the meticulous removal of zero and negative values, followed by deflation adjustments based on the consumer price index. Subsequently, data normalization was conducted utilizing the slope of the line of the CCDF for the lower part of the dataset, plotted on a logarithmic-linear scale for each year. This normalization process was initiated based on the initial estimate of the border income, set at the 99.7th percentile. Finally, an appropriate binning strategy was selected, with a uniform value of 0.4 (∆r≈0.4T) applied to all data subsequent to the initial 0.2 portion.
Plotting the PDF of the income pertaining to the lower class of the society across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—alongside the fitting line of the exponential distribution function for the year 2016 revealed a notable alignment, indicative of a robust fit with the theoretical exponential distribution.
Alternatively, the survival function chart was employed to analyze the income distribution among the upper class of society. Presenting this data graphically across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—for the entirety of 2016 underscored two key findings. Firstly, the tail-end distribution of income follows the Pareto distribution. Secondly, and of paramount significance, these graphical representations unequivocally affirmed the appropriateness of dividing the dataset into two distinct segments.
Plotting the PDF for the 11-year period revealed that the data pertaining to the lower part of the society, representing 99.7% of the total population, converged onto a singular curve following normalization across the entire duration under study. Subsequently, depicting the survival functions for the aforementioned 11-year time frame in a unified graph, utilizing both logarithmic-linear and logarithmic-logarithmic scales, served as a more definitive validation of the two-class theory of income distribution.
Discussion and Conclusion
The analysis of income data in Iran from 2006 to 2016 reveals a distinct two-class structure in the country's income distribution.
Firstly, the lower class, encompassing approximately 97 to 99.7% of the population, follows the exponential Boltzmann-Gibbs distribution, primarily driven by labor income. This statistical distribution reflects a cumulative process characterized by a constant rate of decrease, as indicated by the exponential distribution's parameter. The consistency observed in the exponential fit graphs of the survival function and data histogram across different years suggests the stability of income distribution within the lower class over time. This stability parallels thermal equilibrium in physics, suggesting that the majority of the population is in a stable equilibrium. Notably, the high-resolution histogram of the PDF reveals a sharp and narrow peak at low incomes, attributed to governmental policies such as the imposition of minimum wage regulations.
Conversely, the upper class, constituting approximately 0.3 to 3% of the population, follows a Pareto distribution, predominantly influenced by capital income. However, unlike the lower class, the distribution of income within this part does not align along a single line in the power law segment. This part undergoes discernible fluctuations from year to year, indicating instability within this economic sector. These fluctuations are attributed to the variability of capital income
This paper examines the distribution of income in Iran from 2006 to 2016 and evaluates the validity of one of the latest economic theories concerning income distribution, namely, the Econophysics Two-Class Theory of Income Distribution (EPTC).
According to this model, income distribution generally comprises two classes. The lower class of this distribution, typically representing 97 to 99% of th society, follows the exponential (thermal) Boltzmann-Gibbs distribution, primarily driven by labor income. This distribution remains stable over time and undergoes minimal fundamental changes. Conversely, the income distribution of the upper class, constituting approximately 1 to 3% of society, follows the Pareto distribution, recognized as a superthermal distribution in econophysics. Notably, this distribution exhibits high variability over time, closely mirroring fluctuations in the stock market.
For this study, a review of the theoretical literature on the statistical distribution of income is conducted, tracing its evolution from Pareto's initial attempts to the formulation of the two-class distribution of income. In the methodology section, emphasis is placed on delineating the characteristics of two Probability Density Functions (PDFs) and Complementary Cumulative Distribution Functions (CCDFs) associated with exponential and Pareto distributions. The methodology elaborates on the approach to detecting income distribution patterns within the framework of the aforementioned theory. Subsequently, in the data and findings section, an examination of the income data spanning the specified time period in Iran is undertaken. The section meticulously explores the compatibility of these data with the EPCT, offering detailed discussions on the observed patterns and their alignment with the theoretical framework. Finally, the implications of the EPCT are elucidated, and the paper's conclusions are presented in the concluding remarks section.
Methodology
In complex systems concluding big data or complex models, alternative approaches beyond conventional statistical tests may be employed to estimate distributions. Visual inspection and descriptive analysis, facilitated by histograms and distribution charts, serve as effective tools for approximating distributions without relying on statistical tests. The selection of distributions is informed by theoretical considerations that align with the underlying characteristics of the system. These alternative methods offer practicality and informativeness, particularly in scenarios where traditional statistical assumptions may not hold or when dealing with extensive and unconventional data. The present article adopts this methodological approach to analyze income distribution in Iran.
The initial step involves drawing the histogram and probability density function (PDF). The shape of the histogram guides the identification of distribution. Given the potential complexity arising from large datasets, and the ambiguity that may arise from visual inspection of merely the PDF, a Complementary Cumulative Distribution Function (CCDF) plot serves as a valuable aid. Subsequently, following the first step and the selection of candidate theoretical distributions, the CCDFs are plotted to ascertain the optimal fit with the experimental data distribution. Consequently, the combined use of PDF and CCDF serves as indispensable tools for delineating annual income distribution patterns.
The resemblance between the graphs of the PDF for both exponential and Pareto distributions on a linear-linear scale poses challenges in distinguishing between these distributions. Similarly, the CCDF curve lacks clarity on a linear-linear scale due to this similarity. However, employing a logarithmic-linear scale to plot the survival function related to the data of the lower part of society proves beneficial, as it reveals a smooth line representative of the exponential Boltzmann-Gibbs law. Similarly, plotting the survival function for the upper part of the society on a logarithmic-logarithmic scale serves to elucidate the Pareto power law. Consequently, plotting the survival function for the entire dataset on a logarithmic-logarithmic scale, as per the hypothesis of the EPTC, should unveil two distinct segments: exponential and Pareto.
Findings
The data utilized in this study were derived from the raw tables pertaining to the household expenditure-income (budget) plan, annually published by the Statistical Center of Iran. Specifically focusing on data sourced from the urban population, which constituted approximately three-quarters of the total population during the study period. Data preparation commenced with the meticulous removal of zero and negative values, followed by deflation adjustments based on the consumer price index. Subsequently, data normalization was conducted utilizing the slope of the line of the CCDF for the lower part of the dataset, plotted on a logarithmic-linear scale for each year. This normalization process was initiated based on the initial estimate of the border income, set at the 99.7th percentile. Finally, an appropriate binning strategy was selected, with a uniform value of 0.4 (∆r≈0.4T) applied to all data subsequent to the initial 0.2 portion.
Plotting the PDF of the income pertaining to the lower class of the society across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—alongside the fitting line of the exponential distribution function for the year 2016 revealed a notable alignment, indicative of a robust fit with the theoretical exponential distribution.
Alternatively, the survival function chart was employed to analyze the income distribution among the upper class of society. Presenting this data graphically across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—for the entirety of 2016 underscored two key findings. Firstly, the tail-end distribution of income follows the Pareto distribution. Secondly, and of paramount significance, these graphical representations unequivocally affirmed the appropriateness of dividing the dataset into two distinct segments.
Plotting the PDF for the 11-year period revealed that the data pertaining to the lower part of the society, representing 99.7% of the total population, converged onto a singular curve following normalization across the entire duration under study. Subsequently, depicting the survival functions for the aforementioned 11-year time frame in a unified graph, utilizing both logarithmic-linear and logarithmic-logarithmic scales, served as a more definitive validation of the two-class theory of income distribution.
Discussion and Conclusion
The analysis of income data in Iran from 2006 to 2016 reveals a distinct two-class structure in the country's income distribution.
Firstly, the lower class, encompassing approximately 97 to 99.7% of the population, follows the exponential Boltzmann-Gibbs distribution, primarily driven by labor income. This statistical distribution reflects a cumulative process characterized by a constant rate of decrease, as indicated by the exponential distribution's parameter. The consistency observed in the exponential fit graphs of the survival function and data histogram across different years suggests the stability of income distribution within the lower class over time. This stability parallels thermal equilibrium in physics, suggesting that the majority of the population is in a stable equilibrium. Notably, the high-resolution histogram of the PDF reveals a sharp and narrow peak at low incomes, attributed to governmental policies such as the imposition of minimum wage regulations.
Conversely, the upper class, constituting approximately 0.3 to 3% of the population, follows a Pareto distribution, predominantly influenced by capital income. However, unlike the lower class, the distribution of income within this part does not align along a single line in the power law segment. This part undergoes discernible fluctuations from year to year, indicating instability within this economic sector. These fluctuations are attributed to the variability of capital income
Volume 3, Issue 7 (12-2015)
Abstract
Gender as a social identity, has an important role in the formation of folk poetry, especially poetry and folk Bakhtiari culture. The lyrics besides reflecting different values and beliefs about women and men are important in the internalization of these values. The aim of this study was to evaluate the effect of gender on popular poems (The chansons of caress, Lullabies, and mourning lyrics) of Bakhtiari culture that have been analyzed using content analysis and theoretical basis of gender inequality. Gender divides these poems into two parts; male and female poetry. Home prepares the way in which the women benefit from a private atmosphere that helps them to do several activities like baking, milking and conviviality. Instead social and public activities such as to be with others in assembly, eloquence, rationality, courage and to be belligerent are those of characteristics attributed to men. Gender inequality in the tradition of Bakhtiari culture has a tender signification, in its turn, it means that women are in lower rank in comparison with men .
Volume 4, Issue 1 (10-2012)
Abstract
Gender archaeology is a branch of social archaeology, which was born in the 80s.Itfocouses on the investigation of gender identity and role as social issues in different societies. The Sasanian dynasty was one of the empires of ancient Iran, dating back to 224 - 651 A.D. (Frye 274: 2001). The research investigates the social inequality between men and women in Sasanidempire, Iran. The exertion of some kinds of gender discrimination and men superiority has appeared in archaeological records and Sasanid texts. The presentation of women in the archaeological evidence such as visual arts are rare,in comparison to men. The research follows a comparative method in data analyzing. Based on the above mentioned evidences, this research examines women’s social status and their role in Sasanid society in comparison to other gender groups such as men and children.
Volume 5, Issue 2 (8-2024)
Abstract
Problem: Justice in urban health means the absence of systematic differences in one or more aspects of the health status of citizens or population groups in terms of social, economic and physical environment. In the present study, the city of Urmia has been investigated and analyzed as a focus of studies on the level of realization of the right to health approach to the city and the distribution of health-therapeutic services and functions.
Aims: In terms of its purpose, the current research is in the category of semi-basic, semi-applied research, which is carried out with descriptive and analytical method.
Methods: The methods of collecting information are based on documentary-library methods, observation and field verification (Swara and Cocoso tests).
Findings: Based on the results, the city of Urmia has not acted in a fair manner in terms of the distribution of health-treatment functions and services in accordance with the approach of the right to the city, in spatial planning and allocation.
Conclusion: Regions 4 in the central context and the commercial pole of the city and 2 in the peripheral part of Urmia city have respectively the most favorable and unfavorable environmental conditions and conditions in the matter of enjoying the right to health policies of the city. In the end, based on the findings and the identification of the strengths and weaknesses of the study area in the field of urban development, some targeted and sustainable proposals and actions have been taken to improve the environmental conditions.
Volume 5, Issue 17 (10-2017)
Abstract
This study explores the concept of women in Lori's proverbs with emphasis on gender inequality. To analyze the issue, From the perspective of Barrett's semiotics, discourse analysis Laclau and Mouffe and interpretive Geertz was used. Approach and methodology, Qualitative approach using both documentary study and in-depth interviews with people (men, women) over age 50 were qualified. These individuals selection methods, and interpretation of data, respectively, based on procedure of purposive sampling and analysis is thematic. The data examined, common proverbs in the dialect Lori mamasani, in particular, has been associated with gender inequality. Categories of Analysis proverb can be around subcategories woman superficial, humble, tool, obey the orders, seditious and Telltale, and category or axis signifier " the other inferior" category and analysis. According to Emic look at the analysis of themes and the interviewees, Representations of women in proverbs Larry, to the formation and strengthening of a sexist language and gender discriminatory practice has resulted in the target population. As far as gender language, according to Barthes, the shape of mythic taken and on the basis of discursive look Laclau and Mouffe, A clear boundary contradict between our (male) as sex superior, and the other (women) as inferior sex has been drawn and consolidation. Finally, such an image can reflect gender inequality and the prevention of women's access to positions of their social life is important and valuable.
Assessing the Relationship between Forms of Spatial Inequalities and Sustainable Development in Iran
Volume 7, Issue 1 (2-2025)
Abstract
Spatial inequalities and income and capital gaps between different areas of society are currently considered one of the most significant barriers to sustainable development. Disparities between disadvantaged regions (border or non-border) and developed regions, as well as urban-rural gaps, are the most important signs of spatial inequalities. This paper attempts to study the degree of integration or disparity between urban and rural areas in Iran over the past four decades using a secondary analysis method. Four variables will be analyzed: population distribution, dominant economic and production sectors, poverty levels and distribution, and income and expenditure gaps. Evaluation of the spatial planning system’s performance in the country reveals a sectoral and non-planning approach with an emphasis on centralization and urbanization, which has exacerbated inequalities and disparities between peripheral and central regions, as well as between urban and rural areas. The country has experienced rapid, unplanned, and sometimes uneven urbanization, to the detriment of the sustainability and population balance in small urban areas and rural ones, which has not necessarily been accompanied by balanced regional development. Large cities have attracted a labor force to their peripheries, leading to a life of poverty in marginal and rural areas. While absolute poverty has decreased, rural populations, especially in disadvantaged areas, continue to bear the brunt of poverty. Income and expenditure indicators have also favored urban dwellers. Overall, macro-level data in the country indicates the existence of spatial divisions. However, wherever urban-rural linkages have been established and strengthened, regional and urban-rural disparities have decreased.
Volume 8, Issue 4 (1-2009)
Abstract
Most debates on the role of trade openness and the wage inequality are based on the well-known Hecscher-Ohlin and Stopler-Samuelson (HOS) theories. According to the Heckscher-Ohlin theory, Countries have comparative advantages in those goods for which the required factors of production are relatively abundant locally while the Stopler-Samuelson theory refers to the income distribution effects of trade openness. In this paper, a computable general equilibrium (CGE) model and social accounting matrix (SAM) approach are used to assimilate the effect of tariff cuts on the earnings of production factors and relative wages by using Iran's data for 2001. The results confirm that general tariff cuts lead to a decrease in wage inequality while it leads to an increase in wage inequality in the foods, apparel and textile sectors. However, tariff cuts in agriculture sector reduce wage inequality.
Volume 9, Issue 3 (10-2009)
Abstract
Casual relationship between financial developments and economic growth is one of the striking empirical macroeconomic relationships. Following the development of financial issues, our attention turns from economic growth to another issue of economic welfare. In this study, we try to examine the relationship between financial developments, economic growth, poverty and inequality in OPEC countries. The simulation of the models and statistical inferences, in this study, are based on the static and dynamic panel data approach. The empirical models are estimated by using GMM estimators, fixed effects and random effects using the data between 1990 and 2004. The results of this study show that financial developments through its effect on economic growth can mainly contribute poverty alleviation and inequality reduction in these countries.
Volume 11, Issue 4 (1-2012)
Abstract
This paper addresses adaptive observer design problem for joint estimation of the states and unknown parameters for a class of nonlinear systems which satisfying one-sided Lipschitz and quadratic inner bounded conditions. It’s shown that the stability of the proposed observer is related to finding solutions to a quadratic inequality consists of state and parameter errors. A coordinate transformation is used to reformulate this inequality as a linear matrix inequality (LMI). Sufficient conditions that ensure the existence of adaptive observer are expressed in forms of LMIs, which are easily tractable via standard software algorithms. If the proposed conditions are satisfied, then the state estimation errors are guaranteed to converge to zero asymptotically while, the convergence of the parameters is guaranteed when a persistence of excitation condition is held. The effectiveness of the proposed method is shown by simulation for the joint estimation of states and parameters of a numerical system.
Volume 12, Issue 1 (4-2012)
Abstract
Non-fragile observer design is the main problem of this paper. Using continuous frequency distribution, the stability conditions based on integer order Lyapunov theorem are derived for Lipschitz class of nonlinear fractional order systems. The proposed observer is stable beside the existence of both gain perturbation and input disturbance. For the first time, in this paper a systematic method is suggested based on linear matrix inequality to find an optimal observer gain to minimize both the effects of disturbance on the synchronization error and norm of the observer gain. A comparison has done between this observer and previous research on resilient observer design for nonlinear fractional order systems based on fractional order Lyapunov method. The comparison shows a much broader range of feasible response for the proposed method of this paper besides simpler computing. After presenting thediscussion, chaos synchronization is simulated to show the effectiveness of the proposed method in the end.
Volume 13, Issue 4 (1-2014)
Abstract
In the economic literature, inflation is one of the most important factors influencing income inequality. Since Iran as a developing country has frequently been facing with high and volatile inflation rates, the study of the effect of inflation on income inequality is of considerable importance. Despite the importance of the issue, the few studies that have dealt with this subject have not derived same result, so the effect of inflation on income inequality remains paradoxical. However, the economic studies in recent decades confirm the nonlinear relationship between inflation and income inequality. Inspired by these studies, we investigate the nonlinear effect of inflation on income inequality during 1971-2006. Likewise, we examine the Granger causality relationship between inflation and income inequality by using “Toda & Yamamoto” and “Error correction” procedures during 1971-2007.
Volume 13, Issue 4 (1-2014)
Abstract
This paper has proposed a gain-scheduled controller with stability proof and guaranteed cost for a turboshaft driving a variable pitch propeller. In order to overcome the complexity of the nonlinear model, a linear parameter varying (LPV) model is proposed for the first time which is in affine form. Proposed model is established based on a family of local linear models and is suitable for LPV gain scheduling methods. Thus a gain scheduled design procedure is proposed which considers parameter dependent Lyapunov matrices to ensure stability and a quadratic cost function for guaranteed performance of the closed loop system. Proposed procedure also has the advantage of considering an upper bound for change rate of the scheduling signal which decreases conservativeness. Controller design problem and calculating its gain matrices is formulated in a set of Linear Matrix Inequalities which easily can be solved using LMILAB toolbox. Simulation results showed the effectiveness and practicality of the proposed procedure.
Volume 14, Issue 3 (6-2014)
Abstract
Electro hydraulic servo systems (EHSS) are widely used in all aspects of industry, due to their ability to handle large torque loads and quick response. According to the wide range of use, the desired control objectives for EHSS are: velocity, force/torque and position control. Existing approaches for control of electro hydraulic servo systems are in the presence of external noises, internal friction and non-linearity in the model behavior which is considered as uncertainty parameters. In this paper fuzzy intelligent controller by using parallel distributed compensator (PDC) method based on Takagi-Sugeno is used. The controller is designed for a high level performance (velocity control) which could reach the main control goals. The concluding results of this approach best fit the other researches data.
Leader-Following Consensus of Nonlinear Multi-Agent Systems Based on Parameterized Lyapunov Function
Volume 15, Issue 2 (8-2015)
Abstract
This paper studies the consensus problem of nonlinear leader-following multi-agent systems (MAS). To do this, the error dynamics between the leader agent and follower ones are described via a Takagi-Sugeno (TS) fuzzy model. If the obtained TS fuzzy model is stable, then all of the nonlinear agents reach consensus. The consensus problem is investigated based on the parameterized or fuzzy Lyapunov function combined with a technique of introducing slack matrices. The slack matrices cause to decouple the Lyapunov matrices from systems ones and therefore, sufficient consensus conditions are obtained in terms of linear matrix inequalities (LMIs). The proposed slack matrices add an extra degree-of-freedom to the LMI conditions and also decrease the conservativeness of the LMI-based conditions. Finally, in order to illustrate the effectiveness and merits of the proposed method, a numerical example for the consensus problem of nonlinear leader-follower MAS with thirteen followers is solved.
Volume 15, Issue 3 (11-2015)
Abstract
Inequality in income and wealth distribution as the most critical socioeconomic indicator is highly influenced by political structure. In the recent centuries, democratization along with enfranchisement has caused a course of economic changes including income and wealth redistribution. This study uses a neoclassical microeconomic approach for a hypothetical economy and demonstrates how to being affected incomes inequality and redistribution by enfranchisement in a society whose economic and political power pillars are under control of aristocrats. Theoretical analysis suggests that expansion of democracy leads to less inequality in incomes. Empirical evidence from Iran for the period 1969-2008 indicates that democracy can be a significant determinant in income redistribution.
Volume 15, Issue 3 (11-2015)
Abstract
This study examines the relationship between financial development and income inequality in Iran using bounds testing approach over the period of 1973-2010. In this study the domestic credit to private sector (% of GDP) and the ratio of liquidity to GDP are applied as proxies for financial development. The empirical results indicate that a negative and linear relationship between financial development and income inequality exists. Financial development significantly reduces income inequality in Iran. However, there is no evidence of an inverted U- shaped relation between financial development and income inequality, as suggested by Greenwood and Jovanovic (1990). The empirical findings also suggest that the enhanced institutional quality results in reduced income inequality in Iran.
Volume 15, Issue 3 (10-2012)
Abstract
Objective: The goals of the study are evaluation the effect(s) of food deprivation as a social stress on testis structure. We also investigated the effects of melatonin treatment as an antioxidant component and inequality on the effect(s) of food deprivation. Methods: We investigated the improving effects of melatonin and social stress (food deprivation) on 42 male rats in 7 groups including control, sham, melatonin received (M), food deprivation (1/3 of control daily food) plus observation (FD), FD + melatonin (FDM), isolated FD (FDi), and FDi + melatonin (FDMi) groups. After 14 days, rats' testes were studied using immuno histochemistry and TUNEL assays to determine the number of apoptotic cells. Biochemical evaluation was taken on malodialdehide (MDA) and glutathione (GSH). ANOVA and Tukey's tests were done to analyse the data. PResults: The results of sham group was declined for similarity to results of control group. In FD group, MDA was increased significantly (PConclusion: Food deprivation can induce oxidative stress which is associated with increasment of apoptotic cells in testis. Isolation can compensate these effects. These results refer to inequality. Since melatonin is recognized for its anti-oxidative and improving effects, we have shown involvement of oxidative stress mechanisms on the stress of food deprivation with inequality.
Volume 15, Issue 8 (10-2015)
Abstract
In this paper, the spacecraft formation flying using virtual structure algorithm is studied. In spacecraft formations flying, several small spacecraft have been used instead of employing a single one to achieve the same goal. In virtual structure method, the position and orientation of each spacecraft is measured with respect to the position and attitude of a virtual node in every moment. Two robust control methods are proposed to control formation. At first, the robust μ synthesis controller is used to attenuate the influence of the sensor noises, environment disturbances and parametric uncertainties but it is done with heavy computations. The second method is in the standard form of optimization problem. It is composed of state feedback controller and lyapanov stability theory. The LMI controller Computations are very efficient and the controller is robust against parametric uncertainties and most of the disturbances. The implementations of control methods on virtual center guarantees robust stability and performance. Concerning with Actuator constraints, Simulation example is provided to show the effectiveness of the proposed control schemes to track the desired attitude and position trajectories despite system uncertainties.
Volume 16, Issue 2 (8-2016)
Abstract
One of the fundamental problems in regional economic development is determining the ways in which government can allocate resources of society so that economic growth and income equality among provinces can be achieved simultaneously. In this study, a Vector Auto Regressive Model is estimated using seasonal data during Q1: 2000- Q4:2009. Inter-provincial income inequality is obtained with both Gini Coefficient and Theil Index. The results show that, in short run, income inequality among provinces accelerates economic growth and in long run decelerates it, however, it does not return to its initial level. Economic growth in short run accelerates income inequality among provinces, but decelerates it in long run. Robustness tests with Theil Index, confirm our primary results applying Gini Coefficient.
Volume 16, Issue 3 (11-2016)
Abstract
Distribution of income in society is so important that almost all economists consider it as one of the main aims and missions of the government. As credit constraints cause inequality in society, thus the development of financial intermediaries and financial markets in national level, which affects access of the low-income and poor individuals to credit and financial services, can influence significantly income redistribution in the country. This study aims to examine the relationship between financial development and inequality among the Iranian provinces. By using fixed effects panel data model, and applying Galor-Zeira theory, the relationship between financial development and income distribution is tested in Iran during 2000-2011. The results show that increasing proliferation of financial intermediaries has negative impact on Gini coefficient and results in more equitable income distribution across the provinces.