In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive power dispatch method in a wind-integrated power system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive power generation and active power loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive power resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

This paper describes a new method for the evaluation of non-utility generation impacts on preventive-corrective control of power systems. The proposed method relies on a mixed integer nonlinear optimization and is capable of recognizing the effectiveness of demand side preventive-corrective actions. A number of cases are presented to illustrate the consequences of introducing demand side actions. In particular, it is shown that using the proposed method can significantly reduce total security cost. This algorithm provides a basis for negotiations between the power system operators providers of demand side preventive-corrective actions.  

Introduction: Correction of deep overbite and achieving a long-term stability are still major concerns for many orthodontists. There are three main ways for solving this problem: Bypass arch technique introduced by Ricketts, Segmented arch technique introduced by Burstone and using TADs. The aim of this study was to evaluate and compare the effects of Ricketts and Burstone techniques during correction of deep overbites.Materials and Methods: In this clinical trial, 18 female patients with Cl I and II occlusion and more than 4 mm of overbite were selected. The subjects were divided into two groups (n=9). The deep overbite in group A was treated with Ricketts technique and Burstone technique was used for correction of overbite in group B. Fifteen jaws were included in each group. Lateral cephalograms before and after intrusion were used to evaluate the results. Data were statistically analyzed with Student’s t-test and SPSS 18 (a=0.05).Results: There was a statistically significant difference in the means of true intrusion and extrusion between groups A and B (p value=0.014 and p value=0.47, respectively). However, overbite reduction was not significantly different between the two groups (p value=0.704). In addition, the differences in mean false intrusion (p value=0.02), changes in the axial inclination of posterior teeth (p value=0.047) and the angle between axial inclination of upper and lower anterior teeth (p value=0.002) were statistically significant between the two groups.Conclusion: Under the limitation of the present study, the results confirmed the superiority of Burstone technique in intruding incisors with less undesirable lateral movements.

In this paper, a new method for extending and relaxing the noise-coupling (NC) technique is proposed to enhance the noise-shaping order without adding the number of integrators. The noise-shaping order of the introduced ∑∆ modulator whit applying a second-order noise-coupling technique is enhanced and its performance with optimizing the noise transfer function (NTF) zeros is improved. Also, by removing the analog adder at feedforward path and transferring it to a new feedback branch before the last integrator and adding second-order NC path can be decreased the input voltage swing to the quantizer. Thus, by improving the modulator resolution, power consumption can be reduced. Mathematical analyses and behavioural simulation results confirm the effectiveness of the new NC method. To examine its performance, a 2nd-order single loop ΣΔ modulator was designed. The new noise-coupling method is used to achieve the three-order noise shaping to increase the resolution with low complexity and low-power. The results show an outstanding improvement in signal-to-noise and distortion ratio (SNDR) compared to the conventional structure.

In order to extend our understanding of neoclassical school of thought this paper focuses on the utility doctrine of StaneIy Jevons. More specifically, in an effort to investigate the underlying axioms of this doctrine, our paper concentrates on ethical, philosophical and methodological aspects of "the mechanics of utility and self-interest". The paper argues that Jevons combines the "utility" doctrine of Jeremy Bentham with the economic man of Adam Smith to develop his doctrine. This research discusses how Smiths philosophy of ethics enabled Jevons to solve the inconsistency of the utility theory of Bentham when applied to economics. It is argued that this inconsistency mainly arises ITom the conflict between private and social interests. In order to bypass the criticism arising ITom this conflict, Jevons used Smiths theory to propose that the social benefit can be achieved when a selfish individual peruses his own interest. Moreover, the paper studies the economic method advocated by Jevons and shows how the ratification of this method is the least satisfactory part of his doctrine. The paper concludes that using mathematics, as a major tool in Jevonss doctrine is a natural byproduct of maximization principle and utilitarian approach. Finally, it suggests that one should take into consideration the limitations of Jevonss doctrine before using it as an analytical tool in economics.