سجاد صالحی

One of the challenges of unbalanced population growth and activities in villages located at the regional level and urban peripheries is the formation of unplanned settlements or informal settlements and similar limited areas in encroached or unsuitable agricultural lands in rural areas.The Tehran region has also witnessed various and numerous transformations in population, social, economic, and physical-spatial fields in the surrounding rural areas and its urban peripheries over the past few decades. Due to natural population growth and migration from villages and cities to the Tehran urban area, the population in this region has significantly increased. As a result, due to economic factors influencing location selection, low-income populations have settled in informal settlements in villages located within the immediate vicinity of Tehran. Given these issues, the aim of this research is initially to investigate the trend of formation and expansion of informal settlements in villages located within peri-urban spaces and the urban periphery of Tehran over the past half-century. Furthermore, focusing on examining demographic changes that have occurred in these villages over the past three decades, this research aims to present a current picture of their situation and provide spatial patterns for rural settlements while predicting potential hotspots for informal settlement formation.

This research is classified as applied research based on its objective, descriptive-analytical in terms of content, and qualitative-quantitative in terms of methodology. The necessary data was collected through document reviews, library research, official information, and statistics. To identify, map out, and present a current picture of demographic changes occurring in rural areas during the period between1996-2016 (the Iranian calendar), data from 283 villages with populations were analyzed using SPSS software. In order to identify spatial patterns of rural settlements and predict population density hotspots for potential informal settlement formation within these areas, interpolation methods and kernel density estimation were utilized within a Geographic Information System (GIS) environment. The study area covers an area of 5920 square kilometers centered around Tehran city.

The analysis of the trend of formation and expansion of informal settlements in rural spaces within Tehran's region shows that since the mid- 1940 s apart from land reforms that transformed Iran's land system freeing up labor force along with rapid urbanization due to industrial development led to widespread rural-to-urban migration resulting in the emergence of informal settlements in surrounding towns and villages during this decade. During 1975-1985 two significant events; Islamic Revolution(1979) followed by Iraq-Iran war (1980-1988) played a crucial role in demographic changes leading to informal settlement formation. In subsequent years after 1996 until 2006 migration intensified towards suburban areas from major cities. People unable to afford housing especially in Tehran city moved towards creating new settlements in surrounding villages near Tehran. From 2016 on wards generally there has been a much stronger tendency towards rural populations moving towards larger villages mainly located in semi-southern plains near major cities' suburbs close to other economic centers.Examining population density levels within densely populated rural areas located within Tehran's periphery during 1996-2016 census period revealed that by 2016 population density was at 50 individuals per hectare which increased to 61 individuals per hectare by 2016 reaching close to 85 individuals per hectare by 2016 with a projected increase exceeding 168 individuals per hectare by 2026.Investigating the makeup and spatial patterns of population density in the settlement areas of villages located within the vicinity of Tehran also shows that, in general, the rural population tends to move towards larger villages more intensively on the outskirts of economic centers around Tehran and other urban centers in the region. The highest population density is observed first in villages surrounding urban areas located southwest of Tehran, then in villages southeast of Tehran, and with less intensity in south Tehran.

In the informal spaces around cities due to lower land and housing prices in rural areas, weaknesses in rural management control over construction, land speculation, proximity to the main city, and availability of minimum living facilities in villages have led to an increasing trend towards informal settlement patterns in villages. The housing system in these areas is heavily influenced by the main city and has been affected by various changes and functions.Neglecting and ignoring this settlement pattern in villages will not only have significant consequences for the villages but also pose a serious threat to the city and its residents. In other words, these villages cannot be considered separate from metropolitan areas and should be taken into account in planning processes (redevelopment or empowerment plans related to informal settlement areas) because these villages are constantly connected to the main city and are considered part of the urban area.Keywords: peri-urban villages, informal settlement, spatial pattern, Tehran.

Although natural frequencies and mode shapes can be accurately measured by dynamic tests, error bounds in values of damping estimation can be large. Since damping strongly influences the design and control of structures, efforts are made to find the damping that has the least error. The random and bias errors are the two important types of error in damping estimation of structures via frequency domain methods. These errors can be reduced by choosing appropriate frequency spacing. In this study, the frequency spacing leading to the least bias and random errors for estimation of modal damping is determined. The complexity of the damping phenomenon on the one hand and complexity of the structural behavior of a double layer grid, on the other hand, led to this study. For this purpose, a double layer grid constructed from ball joint system was tested. the modal damping ratios related to the first 6 modes of a double layer grid with the ball jointed system were identified for different frequency spacing via two output only modal identification techniques; namely enhanced frequency domain decomposition (EFDD), curve fit frequency domain decomposition (CFDD). The modal damping ratio estimations identified through the two methods were then compared with the results of the input output identification method of Ibrahim time domain (ITD) as the reference value. The results showed that there is an almost linear relationship between the modal damping ratio estimations and the frequency spacing in each mode. At the frequency spacing of 0.0625 Hz, the modal damping ratios obtained from the output only methods showed the least difference (between 0 to 21.43%) with the reference values. At this frequency spacing, the root mean square deviation of modal damping estimations between enhanced frequency domain decomposition (EFDD) and curve-fit frequency domain decomposition (CFDD) with the corresponding reference values was 0.02.

Rural migration not only leaves fundamental effects on the target habitats, but also causes drastic change on the structure of the source villages. The city of Khoramdarreh witnessed some changes on the price of land, destruction of the surrounding farming lands, and on the formation of the margin and boundaries. It seems that the main reason of such changes is the immigration of villagers from the suburban areas to the city. In the present research, all data and information are collected through the library documents, questionnaire, field study and interview. The main aim of the research is the detection and analysis of the consequences of the rural migration to the city of Khoramdarreh. The statistical society of the present research is the population of Khoramdarreh, and the sampling method is the simple systematic sampling from the central and suburban districts. This research is based on analytic–descriptive method that studies population changes, the price of land, and urban physical development as the main consequences of rural migration. Statistical method is used for the analysis of data and the urban status during the last few years of the period. The results of the study reveal that there is a direct relationship between people's immigration from the surrounding villages of Khoramdarreh to the city of Khoramdarreh. Secondly, there is a close relationship between people's immigration and urban structural changes such as, urban physical development, destruction of farming lands, formation of new urban spaces, development of the margin, and consequently, unreasonable increase in the price of lands.

futures studies is a systematic process for drawing the medium and long term future of science, technology, economy and society so that its purpose is a exploring of strategic research domains and discovering new technologies with profound effects on economy, industrial competitiveness, wealth creation and quality of life. In general, futures studies is included drawing of future in current time even in scenario formats, and opportunities and threats in the future. Since all opportunities aren’t available and some of them must be created and some of threats must be prevented, the organizations are forced to pay attention to opportunities in the future. In this paper, by reviewing related works and documents, foresight literature is done with a meta analysis approach. In the next step, several foresight frameworks that have been introduced by researchers and experts, is reviewed and analyzed. Finally, key technologies in Iranian ICT industry are presented by using of qualitative research methods. For this purpose by enjoying focus group tools, several meetings were held with 9 persons of University of Tehran and ITRC experts. In the end, some business models including mobile service, intelligent computers, electronic assistant and etc. are detected. These models are the result of Iranian key technologies recognition and their capabilities.