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Showing 3 results for shahnazi


Volume 17, Issue 3 (5-2017)
Abstract

In this paper, an optimal Fractional-order Proportional-Integral-Derivative (FOPID) controller is proposed to control an offshore 5MW wind turbine’s pitch angle in above rated speed. The proposed pitch controller regulates the generator angular speed and consequently the generator power to its nominal value without any knowledge of the model. In order to find the parameters of the controller, a hybrid cost function is proposed, which consists of sum of absolute error signal and absolute rate of control signal in three different wind speeds. The wind speeds are chosen in the beginning, middle and at the end of the interval, thus, the optimized controller is able to show an acceptable performance in whole range of wind speeds, without any demand to nonlinear and complex controllers. To this end, the proposed cost function is minimized using three optimization algorithms: Differential Evolution (DE), Firefly algorithm and Particle Swarm Optimization (PSO). In order to evaluate the robustness of proposed FOPID, numerous wind profiles with different speeds and fluctuations are applied and the results are compared with the optimal integer order PID controller. The comparison demonstrates that the proposed FOPID has more effective performance and robustness than optimal integer order PID.
Mr Mojtaba Panahi, Dr Rouhollah shahnazi, Dr Karim Eslamloueyan, Dr Ali Asgary,
Volume 24, Issue 2 (summer 2024)
Abstract

Introduction:
In recent years, policy makers have increasingly recognized the significance of vulnerability to climate change. This urgent situation necessitates the implementation of immediate, extensive, and comprehensive measures. Extensive scientific consensus has demonstrated that human activities have contributed to significant climate warming trends. However, despite this evidence, there are individuals who remain skeptical and deny the existence of climate change. Consequently, addressing this skepticism and effectively tackling the climate crisis require fundamental changes in behavior and attitudes across various levels and domains of human life. Therefore, the primary objective of this article is to examine the behavioral factors involved in climate policy making, with a particular emphasis on the role of cognitive biases.
Methodology:
This research employed a semi-experimental method, drawing on the principles of behavioral economics. The study utilized a design that included both an experimental group and a control group, with pre-test and post-test assessments. The experimental group was exposed to different information frames, which were developed based on the principles of behavioral economics, while the control group did not receive any framing intervention.
Data for this study was collected through fieldwork and a questionnaire. The statistical population consisted of individuals who had access to WhatsApp, Telegram, and Instagram platforms during the experiment, which took place in the spring of 2023. The target sample size for this research was determined to be 600 participants, divided into six groups of 100 individuals each. The sample size was determined using Cochran's formula for limited populations. Additionally, a random sampling method was employed in this research.
Results and Discussion:
This article aims to establish a connection between climate policy and behavioral sciences by introducing the practical and cost-effective approach of nudge theory. Drawing on insights from behavioral economics, specifically through behavioral interventions that leverage biases such as loss aversion, hyperbolic discounting, and the framing effect, this study investigates how these interventions can encourage individuals to make choices that align with addressing climate change and environmental concerns. Moreover, existing research has demonstrated that integrating the framing effect with other cognitive biases can be an effective and low-cost policy tool for studying environmental behavior.
Using a semi-experimental methodology, this article examines the impact of information formatting, including profit and loss framing, hyperbolic discounting bias, as well as extensive and continuous information presentation, on individuals' general attitudes and understanding of climate change. The hypotheses of this research were derived from the literature of behavioral economics, cognitive science, and previous studies in the field of environmental issues. The findings of this research indicate that individuals exhibit a greater sensitivity to loss framing, supporting hypothesis H1. In other words, people are more responsive to potential losses than gains when making decisions. Additionally, the results demonstrate that individuals display a significantly higher willingness to participate when presented with present-loss and present-profit framing compared to future-loss and future-profit framing, aligning with hypothesis H2. This preference for the present over the future, known as present bias and hyperbolic discounting bias, has been extensively examined and validated in behavioral economics literature. Furthermore, the findings show that framing losses and emphasizing the present context contribute to a heightened perception of risk, consequently increasing individuals' willingness to take preventive measures under a loss framework.
Additionally, the provision of information in a broad and continuous manner also yielded a significant effect in influencing individuals' behavior, corroborating hypothesis H3.
Conclusion:
This study offers novel insights for policymaking and governance regarding public participation in mitigating the impacts of climate change. The findings indicate that the utilization of loss-present framing and continuous framing proves more effective in increasing the willingness of the general public to engage in climate change reduction efforts. Based on the research conducted in this article, climate change mitigation policies can be effectively promoted in public settings through the implementation of nudges that employ loss-present framing when delivering information.
Furthermore, the current reliance on economic incentives in most policies to encourage public participation is a noteworthy issue. However, this study proposes the use of non-economic incentives and demonstrates the positive impact of nudges on individuals' willingness to engage in projects aimed at reducing the effects of climate change

Mrs Nahid Gohartash, Dr Rouhollah shahnazi, Dr Ahmad Sadraei Javaheri, Dr Mahboubeh Jafari, Dr Parviz Rostamzadeh,
Volume 24, Issue 4 (Winter 2024)
Abstract

Aim and Introduction
Making changes in the tax system is one of the basic and important needs for increasing government tax revenues. To achieve this, the tax system must move in a direction that increases the tax base. One of the most important solutions can be reducing tax exemptions and deductions. Since tax deduction plays an important role in determining tax revenues, ignoring its effect in tax studies can lead to misleading results. To address this research gap, this study uses a three-part dynamic general equilibrium model to estimate the Laffer Curve and investigate the effects of tax deductions on the curve and taxable income.
Findings
The analysis focuses on the household, business, and government sectors, highlighting the significance of tax deductions within each.
Findings from this research show that, in the absence of tax deductions, the optimal tax rate for maximizing tax revenue in terms of labor income is below 45%, while for capital income, it is below 40%. In contrast, when tax deductions are present, tax rates exceeding 50% and 55% maximize tax revenue for labor and capital income, respectively. Furthermore, the elasticity of taxable income for both labor and capital remains relatively constant across scenarios, with a slightly higher value observed when deductions are considered. Regarding capital income, the elasticity consistently exceeds 1 due to the presence of varied capital deductions. In both cases, the elasticity exhibits a downward slope, gradually decreasing as the tax rate increases and approaching a value of 1. In contrast, the ETI associated with labor income remains below 37%, regardless of the presence or absence of deductions.
Furthermore, under tax revenue elasticity, the rate of reaction to the tax rate for the labor force is almost uniform in low tax rates and has a downward trend with the increase of the tax rate in all three cases (considering and not considering deductions). But in the case of reductions in the labor force, the amount of reaction is higher than the other two cases. While the elasticity of tax income from capital gains due to capital depreciation deductions is always greater than 1 and is downward in all three cases and gradually decreases with the increase of the tax rate and approaches 1.
Methodology
In the current research, to understand the effects of tax exemptions and deductions in the economic system, an attempt has been made to analyze the effects of tax deductions on the government tax revenues and the elasticity of taxable income and tax elasticity, in a simple three-part dynamic general equilibrium model including households, firms and government, three special cases regarding the absence of tax deductions and social security premiums should be investigated. To evaluate and estimate the model, first the calibrated parameters in previous studies were collected and then the results were obtained through MATLAB software.
Discussion and Conclusion
One of the important results of this research is the changes in the government tax income and the reaction of individuals in the form of taxable income, caused by the consideration and non-consideration of deductions and tax exemptions on the household and corporate sectors.
As it can be seen, tax revenues in the scenario of removing tax deductions are more than the other two scenarios, i.e. considering deductions, on the other hand, the elasticity of taxable income in the presence of tax deductions show a greater reaction than in the case of not considering tax deductions.
Iran has been experiencing consecutive budget deficits over different periods. As a result of reduced oil revenues much greater attention has been drawn to a more efficient and effective taxing system. So, a substitution in the government revenue system can potentially deminish the over-dependence of the Iranian economy on oil revenues, which can lead to far reduced deficits both in the long and short term.
In terms of deductions and exemptions as a factor affecting tax revenues, it can display a more realistic picture of an economy and take into account the existing economic realities. Therefore, the tax system should act in such a way that it moves in the direction of expanding the tax base. One of the solutions for this is realized through elimination of tax exemptions and deductions. It seems that such policies can prevent tax evasion, collecting more tax, and ultimately increase the motivation for work and activity and cause economic growth and prosperity


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