-
Open Access Article
1 - Exploring the features of complexity theories in Tehran City Comprehensive Plan (2007)
Esfandiar Zebardast Mohammad Amin SaeidiTodays’ cities are accepted as dynamic and ever-changing phenomena and are classified as “complex systems” in which Planning encounters with much “uncertainties”. In this kind of systems, absolute cognition of existing condition is impossible. In complex systems, “optim MoreTodays’ cities are accepted as dynamic and ever-changing phenomena and are classified as “complex systems” in which Planning encounters with much “uncertainties”. In this kind of systems, absolute cognition of existing condition is impossible. In complex systems, “optimum” is not predictable. So, we cannot be sure about the existing condition of complex systems nor about the future and the consequences of our manipulation, then, how can we think of planning in this system? Complexity theories are about studying nonlinear dynamic complex systems. These theories deliver new approaches to study complex systems like cities. Complex systems have some common characteristics which introduces them. Openness, ever-changing, non-linear behaviors, non-equilibrium and being on the edge of chaos, self-organization, uncertainty, emergence and naturally unpredictability are some of these characteristics. Therefore, popular linear methods of planning don’t work for complex systems. In this article, eight key elements of urban planning process are proposed based on the complexity theories approaches. Qualitative prediction, gradual evolution (path dependence), actor-space relationship, actor cooperation, self-organization, inhibitor rules, ongoing evaluation, innovation and intuition are introduced with huge literature review as core characteristics of urban planning process. Afterward, in the latest Tehran master plan, use of these key words are analyzed. Summative qualitative context analyze method is used to do this. Tehran has been chosen since the importance of this city in Iran. Tehran is Iran’s capital and also economic center of Iran. It has about 8.7 million inhabitants in about 700 square kilometers area. Tehran has been known as “a problem” since more than fifty years ago. Three development plans are prepared for Tehran but problems like transportation, pollution and etc. are getting worth. Tehran is one of the most complicated cities in Iran, so, is selected as case study in this article. The latest development plan is selected because it is written that Tehran is a very complex problem in that and the plan is prepared with this consciousness. The results of the analysis show that Tehran Comprehensive Plan has not used the concept of gradual evolution, self-organization and innovation and intuition in its process of plan preparation. In the case of ongoing evaluation, just 1 process (each five years) is proposed. Cooperation (of citizens) been referred to mostly in the implementation part of the plan and not in preparation process of the plan. The concept of inhibitor rules are used in the plan, and the most refers to existing sanctioned rules, only 8 new rules are developed in the plan. Actor-space relationship is user 11 times in the plan. Qualitative prediction is used as some patterns and processes in the plan and the most are related to proposed stage. After all, it seems that eight key word proposed in this article are seldom used in Tehran comprehensive plan. In complex context of Tehran it is recommended to use complexity theory concepts to better understand the status-quo and the existing trends. Off course, this is not only the duty of preparation organizations but also all who are involved in the plan Manuscript profile -
Open Access Article
2 - Solving Urban Problems by Means of Fuzzy Systems
farah habib Dr Ali ShokoohiThe study of complex systems is bringing new vitality to many areas of science where a more typical reductionism strategy has fallen short. Complexity expresses a condition of numerous elements in a system and numerous forms of relationships among the elements. In this MoreThe study of complex systems is bringing new vitality to many areas of science where a more typical reductionism strategy has fallen short. Complexity expresses a condition of numerous elements in a system and numerous forms of relationships among the elements. In this regard, urban systems are complex and finding their elements and relationships is a wicked problem. The search for scientific bases for confronting these problems is bound to fail, because of their aggressive nature. The kinds of problems that urban planners deal with, societal problems are inherently different from the problems that scientists and perhaps some classes of engineers deal with. Planning problems are inherently wicked. As distinguished from problems in the natural sciences, which are definable and separable and may have solutions that are findable, the problems of urban planning are ill-defined; and they rely upon elusive political judgment for resolution. But nowadays, scientists are seeking non-linear coupling rules for resolute complex systems problems. In these endeavors, fuzzy systems are an alternative to traditional notions of logic that can cope with complexity of systems. Fuzzy systems provide a rich and meaningful addition to standard logic. Utilizing fuzzy systems in an urban environment raises the likelihood of encountering difficult stability problems. This paper aims to follow the بررسی امکان بکارگیری نظریه فازی در تحلیل مسائل پیچیده شهرapplication of fuzzy systems in the analysis of urban complex problems; In the first part of the paper, authors review definition of urban problem with system approach.مسأله، مانعی است که دستیابی به اهداف دلخواه را با دشواری مواجه می‏سازد. A problem is an issue or obstacle which makes it difficult to achieve a desired goal or purpose. It refers to a situation or issue that is yet unresolved. In a broad sense, a problem exists when an individual becomes aware of a significant difference between what actually is and what is desired. In urban studies an urban problem is difference between an observed condition and a desired condition in a city. Thus urban planning is identifying the actions that might effectively narrow the gap between what-is and what-ought-to-be in a city. (حبیب a 1383)….. For eliminate or reduce the distance between the existing and desired conditions, it is necessary to recognize of complex system constructive elements and the interrelationships between them. برای حذف یا کاهش فاصله میان وضع موجود و وضع مطلوب لازم است که عوامل و عناصر سازنده سیستم پیچیده شهر و روابط میان آنها مورد شناسایی قرار گیرد. بنابراین مسأله شهری، در واقع یافتن اجزا و عناصر سازنده یک پدیده شهری و نحوه پیوند و عملکرد آنهاست. Therefore, urban problem, is finding elements of the urban system and relationships between them. This study is concerned with proposing of a fuzzy system driven approach for solving urban problems and introduces a new model for solving urban problems with fuzzy systems principles. In this model, expert knowledge of urban field converts to fuzzy "If-Then" rules at the first. Then a Fuzzy Urban Decision Engine (FUDE) that connected to a rules database, return a fuzzy solution for a wicked problem. The findings indicate that the fuzzy system methods are powerful processes and analytic tools for helping planners to resolve urban complex problems. These tools can be successful where as others have failed because both incorporate or address uncertainty and risk; complexity; systems interacting with other systems; competing points of view and values; different people knowing different parts of the urban problem; and inter organizational politics. Manuscript profile -
Open Access Article
3 - Resolution of Fuzzy Complex Systems of Linear Equations Via Wu's Method
H. Farahani M. Paripour -
Open Access Article
4 - On Complex Systems and Structure of Emergence in Games- A Survey
Hassan Rashidi Latifeh Pour Mohammad Bagher -
Open Access Article
5 - Chaotic Time Series Prediction Using Optimal Fuzzy Systems Based on Sequential Quadratic Programming-Case Study: Gold Price
Rasoul Rajaei Ali Akbar Gharaveisi Seyed Mohammad Ali Mohammadi -
Open Access Article
6 - Reliability analysis of repairable systems using system dynamics modeling and simulation
M. Srinivasa Rao V. N. A. Naikan -
Open Access Article
7 - Applying Random Matrix Theory Approach for Making Portfolio Enable to Beat the Market
N.S. Safavi Mobarhana Gholamreza Jafari Ali SaeediWe applied Random Matrix Theory making a portfolio enables to beat the market. On the basis of previous findings, the largest eigenvalue represents the influence of the entire market that is common to all stocks. We analyzed cross-correlation between returns of differen MoreWe applied Random Matrix Theory making a portfolio enables to beat the market. On the basis of previous findings, the largest eigenvalue represents the influence of the entire market that is common to all stocks. We analyzed cross-correlation between returns of different stock market indices (S&p500, DJ USA, DAX Germany, FTSE100 England, HSI Hong Kong for efficient markets and TSE Iran, SSE180 China and MXX Mexico for emerging markets) for 730 trading days from May 2012 to October 2014 by using Random Matrix Theory (RMT). Looking at the largest eigenvalue and components (stocks) of the largest eigenvector (demonstrating market mode or trend) and calculating share of every stock in market trend, we could categorize stocks in terms of their impact on the trend in 3 groups: high, middle and low or no impact on market trend. Then we created 3 portfolio in this respect for Tehran stock market. The results shows the portfolio consisting of high impact stocks can beat the market return. Manuscript profile
Sanad
Sanad is a platform for managing Azad University publications
Links
Related Centers
Technical Support
Official pages
The rights to this website are owned by the Raimag Press Management System.
Copyright © 2021-2024