The underground economy has long been of interest to economists and has devoted extensive studies to itself in economic literature. Through fuzzy logic approach in present research, we estimated the size of underground economy of Iran over the period of 1978-2010. For this purpose and according to theoretical bases and previous studies, variables such as GDP per capita, ratio of direct taxes to...

Values have very important functions in any society. The significance  becomes so clear when a society has been exposed to changes and strengthening social cohesion is viewed as an essential subject. Great changes as the Islamic Revolution and the Imposed War have been happened in Iran during last several decades. In this line, generations can be understood via  direct or indirect experience of...

Many view the period after the Second Industrial Revolution as a paradigm of a transition to a new economy following a technological revolution, including the Information Technology Revolution. We build a quantitative model of diffusion and growth during transitions to evaluate that view. With a learning process quantified by data on the life cycle of US manufacturing plants, the model accounts...

In the past three years our views on how the standard model of particle physics could be embedded into string theory have dramatically changed. The heterotic string is no longer the only possibility for such an embedding and other perturbative (or non-perturbative) corners of M-theory, like Type I or Type II strings seem now possible. It has also been realized that the string scale Ms is not ne...

The first Industrial Revolution and most technological developments preceding it had little or no scientific base. It created a chemical industry with no chemistry, an iron industry without metallurgy, power machinery without thermodynamics. Engineering, medical technology, and agriculture until 1850 were pragmatic bodies of applied knowledge in which things were know to work, but rarely was it...

The quantitative revolution in geography in the 1960s and 1970s was an exciting time to be a post-graduate student. Like many social scientists, geographers at that time wanted to make the ‘intellectual music’ of science, the anthem of geography, from an orchestra of common methods and techniques. It is therefore with great appreciation that we thank Peter Haggett for providing retrospective co...

11 Chong, C., and G. Fedde, "Magnetic films: Revolution in computer memories," Proceedings Fall Joint Computer Conference, 1962. 12 Pohm, A. V., R. J. Zingg, T. A. Smay, G. A. Watson, and R. M. Stewart, "Large, high speed, DRO film memories," Proceedings of the International Conference on Nonlinear Magnetics, 1963. 13 James, J. B., B. J. Steptoe, and A. A. Kaposi, "The design of a 4,096 word on...

Four decades ago in Silent Spring, Rachel Carson (1962) wove together a fabric of evidence suggesting that parts of the modern chemical revolution were having unintended consequences, undermining human and wildlife health in unexpected ways. At the time that fabric was more Chantilly lace than Afghan rug, with the scientific pattern defined as much by the holes as by the threads of connecting e...

abstract background: the aim of this study was to compare the effects of the second- and third-generation oral contraceptives on women’s reproductive sexual function. materials and methods: this randomized, double-blind, placebo-controlled clinical trial was conducted on 82 married women of reproductive age in tehran. samples were randomized into the groups receiving second- and third-generatio...