مطالب

Nowadays, Spatial and social inequalities are universal and expanding phenomenon. Identification and spatial analysis of social, economic and ecological inequalities in metropolises is one of the essential and basic proceeding for planning and achieving urban sustainable development. The present research method is descriptive-analytical and using 13 sub criteria based on three main criteria of social, economic and environmental analyzes the status of spatial fragmentation among the metropolis Tehran's districts. For this purpose, the criteria and sub- criteria's internal and external dependencies was determined using the Delphi and ANP method in Super Decisions Software and assessed and scored relative to each other. The results of assessing the indicators shows that Tehran metropolis lacks of the physical unity and spatial heterogeneity between the north and south of the city remains as main feature of its spatial structure. It is necessary that the authorities of Tehran urban management to take actions for better understanding of this phenomenon and consequently offer new and efficient solutions for reducing the effects of various impacts of spatial inequality and duality. For this reason, it is essential to rethink the concept of city in terms of social, economic, political, and ecological and sustainability dimensions.

The questions of centralization and decentralization arise in every polity. The constitution or the practice or both have to settle how much of policy making is to be decided by the central government and by component bodies. By and large liberalism and decentralization tend to go together while authoritarianism tends to be associated with centralization. The constitutional model which is generally regarded as bringing about the largest amount or decentralization is federalism. This is said to sonstitute a half way house between confederacies (where component units dominate)and unitary states (where the center dominates) In its classical form at least , federalism stipulates that there have to be two independent levels of government (the centre and upper level component bodies (often named states) each of these levels has the right to decide on matters falling within its own sphere. There are difficulties in practice especially with respect to the constituent power and to the fields allocated to each level. Federalism must be based on a rigid constitution there has to be s supreme court protecting the independence of the two levels of government there has to be a second chamber defending the rights of the component bodies at the central level.yet there are variations in the extent to which the component bodies are protected and generally in the extent to which there is decentralization. On the one hand federal states are becoming more centralized on the other centralization cannot go beyond a given point without leading to gross inefficiency and perhaps to a break up of the regime as the communist experience showed. Partly for this reason there is a degree of convergence between federal and unitary states. Federalism is also associated with efforts to bring together independent states but this has occurred in a smell number of polities only. Attempts at achieving closer cooperation between states has led more commonly to confederacies, such as the Unites Nations. The European community or European :::union::: has innovated by forming a type of association labeled supranational which is intermediate between the confederal and the federal models. There is innovation in that developments take place gradually with new fields beings progressively covered new structures being set up and new member states joining. The problems of centralization and decentralization have exercised the minds of many in relation to many types of organization : both efficency and freedom appear to be at stake . federalism succeeded in a number of contexts but it is not the panacea which some suggest it is it is also so diverse that one has to refer to federalisms rather than to federalism . what is at stake is the need to find an equilibrium between the two extremes of over centralization and break up. Given the large number of situations in the contemporary world one should look for a variety of solutions and for a continuous evolution of the models which have hitherto been proposed.

Utopian thoughts have precedence as old as human history. Islamic civilization utopian thought owes its progress to the Farabi&rsquos utopian concept and expansion and academic study of utopian term in west owes to the Thomas More Utopia book. Theoretically, Farabi&rsquos utopian thoughts influenced development of utopian system in both Islam and Western civilizations. By emphasis on Farabi&rsquos Utopia as an example of utopian ideas in Islamic civilization, and Thomas More&rsquos Utopia as an example of utopian though in the western civilization, this research tries to investigate the commonalties and differences of these utopias. The architectural and urban building spaces of these examples were studied in the conceptual viewpoint. Thomas More Utopia consists of fifty four similar cities. All of the cities have been constructed well according to the same plan as possible as. The nearest cities have approximately twenty four miles distance, and the furthest ones are not so far from each other so that the people can travel less than one day. Because of similarities in the cities, only one of them has been referred in the &ldquoUtopia&rdquo this city is Amaurot. Each city sends three wise old men to Amaurot every year to negotiate on their common affairs. Amaurot is the main city of the island and it is near the center of the island. &ldquoThe opinions of the Utopians&rdquo and &ldquoThe Policy of the City&rdquo are two books of Farabi. He expresses the political and philosophical systems of Utopia comprehensively. He divides communities qualitatively and in addition, there are cities in contrary to Utopia. He pays attention to the quality of communities from perfectionism and auspicious perspective. In other words, the goal of the city determines type of the city. Farabi likens utopia to a creature that has independent existence beyond the members of the city. The comparison of the architectural and urban building spaces of Farabi&rsquos utopia and Thomas More&rsquos utopia showed that both of the cities are placed in the defined space from urban structure perspective both of them have defined volume and level, and the difference is that Thomas More&rsquos utopia is located in an islands and Farabi&rsquos utopia is universal. The More&rsquos city has a defied localization but Farabi&rsquos city does not posse this characteristic. Farabi has referred to the market space and transaction regarding to the urban micro spaces while Thomas More has referred to passages, hospitals, market and hall and other specification, situations and services. More has not explained the social and geographical divisions, but Farabi divides his utopia into complete and incompetent city and offers subcategories of human communities. Thomas More has emphasized on the urban divisions on streets and fragmentation of the city and also has referred to details like type of material, material used and entrance of city while, in Farabi&rsquos utopia has no references to the details of the architectural spaces and he has emphasized on educational and social goals.