Hybrid intelligent strategy for multifactor influenced electrical energy consumption forecasting

ABSTRACT

This paper proposes a novel hybrid strategy based on intelligent approaches to forecast electricity consumptions. The proposed forecasting strategy includes three main steps: (a) the evaluation of a correlation coefficient for socio-economic indicators on electric energy consumptions, (b) the classification of historical and socio-economic indicators using the proposed feature selection method, (c) the development of a new combined method using Adaptive Neuro-Fuzzy Inference System and Whale Optimization Algorithm to predict electrical energy consumptions. The simulation results have been tested and validated by real data sets achieved within 1992 and 2010 in two pilot cases in a developing country (Iran) and a developed one (Italy). The research findings pinpointed the greater accuracy and stability of the new developed method for electrical energy consumption forecasting compared to existing single and hybrid benchmark models.     

Model-order reduction using variational balanced truncation with spectral shaping

This paper presents a spectrally weighted balanced truncation (SBT) technique for tightly coupled integrated circuit interconnects, when the interconnect circuit parameters change as a result of statistical variations in the manufacturing process. The salient features of this algorithm are the inclusion of the parameter variation in the RLCK interconnect, the guaranteed passivity of the reduced transfer function, and the availability of provable spectrally weighted error bounds for the reduced-order system. This paper shows that the variational balanced truncation technique produces reduced systems that accurately follow the time- and frequency-domain responses of the original system when variations in the circuit parameters are taken into consideration. Experimental results show that the new variational SBT attains, in average, 30% more accuracy than the variational Krylov-subspace-based model-order reduction techniques.     

Synthesis of silica-supported ZnO pigments for thermal control coatings and analysis of their reflection model

A spacecraft in orbit undergoes extreme temperature cycling, space radiations, and other extreme conditions that can potentially raise the temperature of spacecraft to harmful levels. Hardware and sensitive detectors utilized in spacecrafts require that temperatures be maintained within specified ranges. Thermal control coatings (TCCs) help to maintain the thermal equilibrium of the spacecraft at a level acceptable for vital components. This is done by employing the diffused reflection of all effective ultraviolet (UV), visible (VIS), and near-IR (NIR) wavelengths of solar radiation and emitting the infrared (IR) energy. The most commonly used TCCs have utilized potassium silicate as the binder and ZnO as the pigment (Z-93), but absorption of UV light by ZnO pigment affects the ideal scheme of these TCCs. In the present study, silica-supported zinc oxide particles with different ZnO contents were synthesized as pigments for white thermal control coatings and the optimized one was selected based on the experimental determination of the optical properties of the prepared coatings. The results revealed that the optimized TCCs containing pigment with the zinc to silicon ratio of 1.91 had better reflection and emission properties in comparison with Z-93, due to the improvement in the refractive index and the dispersion quality of pigment. Then, the scattering properties (S) of the synthesized pigments and ZnO in TCC were investigated based on the reflectance data, according to the Kubelka–Munk analysis. The general trend in scattering coefficients for each formulation showed the same shape, such that with the increase in S values, the zinc to silicon ratio of pigments was raised too. Also, this trend revealed that scattering was more efficient at longer rather than shorter wavelengths. For Z-93, this trend was completely opposite. Also, S values for Z-93 in the wavelength range of 200–400 nm were around zero, while for the prepared coatings, this was not the case. Finally, the statistical nonlinear regression method was utilized to prepare a model for reflectance as a function of the zinc to silicon ratio of pigments and the wavelength of light.     

Numerical Simulation of Non-cooperative and Cooperative Equilibrium Solutions for a Stochastic Government Debt Stabilization Game

Computational Economics - In this article, we consider the impact uncertainty has on policies and realization of targets aimed at the stabilization of government debt. The problem is motivated by...     

Closed‐form solution to finite‐horizon suboptimal control of nonlinear systems

Finite‐horizon optimal control of input‐affine nonlinear systems with fixed final time is considered in this study. It is first shown that the associated Hamilton–Jacobi–Bellman partial differential equation to the problem is reducible to a state‐dependent differential Riccati equation after some approximations. With a truncation in the control equation, a near optimal solution to the problem is obtained, and the global onvergence properties of the closed‐loop system are analyzed. Afterwards, an approximate method, called Finite‐horizon State‐Dependent Riccati Equation (Finite‐SDRE), is suggested for solving the differential Riccati equation, which renders the origin a locally exponentially stable point. The proposed method provides online feedback solution for controlling different initial conditions. Finally, through some examples, the performance of the resulting controller in finite‐horizon control is analyzed. Copyright © 2014 John Wiley & Sons, Ltd.     

Design of a dual‐polarized omnidirectional antenna for broadband applications

A broadband dual‐polarized omnidirectional antenna is presented. The proposed antenna consists of two parts, an asymmetric biconical antenna and a cylindrical multilayer polarizer. To have an almost perfect omnidirectional radiation pattern in the horizontal plane and the main radiating beam position at around , in the elevation plane, the asymmetric biconical antenna is used. Moreover, to provide dual polarization performance over the 2–18 GHz operational bandwidth, a multilayer polarizer is designed and optimized. Numerous simulations via Ansoft HFSS and CST microwave Studio CAD tools have been made to optimize the radiation pattern, gain, polarization, and the reflection coefficient of the antenna. Simulation results show that the radiation characteristics of the proposed antenna are extremely sensitive to the configuration and dimensional parameters of the multilayer polarizer. The designed antenna was fabricated with high mechanical accuracy and measured. Satisfactory agreement of computer simulations and experimental results was obtained. The main feature that distinguishes this antenna from the previous designs is the ability to provide the omnidirectional radiation pattern with small ripples, dual polarizations performance, and the wide bandwidth simultaneously. Based on these characteristics, the proposed antenna can be useful for broadband communication applications. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:591–600, 2015.     

A computational method for solving two‐dimensional nonlinear variable‐order fractional optimal control problems

In this paper, a new class of two‐dimensional nonlinear variable‐order fractional optimal control problems (V‐OFOCPs) is introduced where the variable‐order fractional derivative is defined in the Caputo type. The general procedure for solving theses systems is expanding the state variable and the control variable based on the Legendre cardinal functions in the matrix form. Hence, we derive their operational matrix of derivative (OMD) and operational matrix of variable‐order fractional derivative (OMV‐OFD). More significantly, some properties of these basis functions are proved to be exploited in our approach. Using these achieved results, we simply expand the matrix form of the nonlinear performance index in terms of the Legendre cardinal functions and subsequently convert it to an algebraic equation. We emphasize that it is a valuable advantage of applying cardinal functions in approximation theory. Then, we implement the OMD and the OMV‐OFD of the Legendre cardinal functions to transform the variable‐order fractional dynamical system to a system of algebraic equations. Next, the method of constrained extremum is applied to adjoin the constraint equations including the given dynamical system and the initial‐boundary conditions to the performance index by a set of undetermined Lagrange multipliers. Finally, the necessary conditions of the optimality are derived as a system of nonlinear algebraic equations including the unknown coefficients of the state variable, the control variable and the Lagrange multipliers. The applicability and efficiency of the proposed approach are investigated through the various types of test problems.     

Design of a Modified Wilkinson Power Divider with Size Reduction and Harmonics Suppression using Triangle-Shaped Resonators

Wireless Personal Communications - Over the past few years, Internet of Things security has attracted the attention of many researchers due to its challenging and constrained nature. Particularly...     

Plasmonic Color Filters as Dual‐State Nanopixels for High‐Density Microimage Encoding

Plasmonic color filtering has provided a range of new techniques for “printing” images at resolutions beyond the diffraction‐limit, significantly improving upon what can be achieved using traditional, dye‐based filtering methods. Here, a new approach to high‐density data encoding is demonstrated using full color, dual‐state plasmonic nanopixels, doubling the amount of information that can be stored in a unit‐area. This technique is used to encode two data sets into a single set of pixels for the first time, generating vivid, near‐full sRGB (standard Red Green Blue color space)color images and codes with polarization‐switchable information states. Using a standard optical microscope, the smallest “unit” that can be read relates to 2 × 2 nanopixels (370 nm × 370 nm). As a result, dual‐state nanopixels may prove significant for long‐term, high‐resolution optical image encoding, and counterfeit‐prevention measures.