This paper presents a new robust adaptive inverse control approach for a force-reflecting teleportation system with varying time delay. In this approach, using the Smith predictor idea, an impedance controller and an adaptive inverse controller are designed, respectively, for the master and slave robots such that the stability and performance of the closed-loop system are achieved in the presence of communication channels varying time delay. Also, based on robust control theory, two sufficient conditions for the stability of overall system are derived. The time domain desired specifications are contained in the design problem using the standard characteristic polynomials. Also, the proposed approach is compared with the sliding mode control. The simulation results show the proposed approach successfully compensates the position drift although time delay is randomly varying.

In this paper, inverse design to determine unknown heat source distribution in a radiant enclosure using an optimization method is investigated to produce desired emissive power and heat flux profiles on a diffuse-nongray design surface of a two-dimensional radiant enclosure. The medium of enclosure is emitting-absorbing, and the design surface emissivity is assumed to be varied with respect to wavelength. Regarding diffuse-nongray design surface, the variation of emissivity with respect to the wavelength is approximated by considering a set of nongray bands with constant emissivity and then the radiative transfer equation is solved by the discrete ordinates method for each band. The total heat flux on each surface element of the design surface is approximated by a summation over the contribution of nongray bands. The conjugate gradient method is used to minimize an objective function, expressed by the sum of square residuals between estimated and desired heat fluxes over the design surface. The sensitivity problem is approximated by differentiation of the radiative transfer equation with respect to the unknown variables. The performance of the present method is evaluated by comparing the results with those obtained by considering a diffuse-gray design surface. The results show that the heat source distribution is well recovered over the heat flux specified design surface in an appropriate range of accuracy.

In this research, the aerodynamic design of a centrifugal compressor is carried out using an inverse design method. At the first step of the aerodynamic design, the shape modification capability of compressor meridional plane is generated by linking up the Ball-Spine inverse design algorithm as a shape modification algorithm and quasi 3D analysis code as a flow solver. Then, the meridional plane is modified by improving the hub and shroud pressure distribution and applying it to the inverse design code. At the second part of this research, by developing a novel design method on the blade to blade plane, and incorporating it into the quasi 3D flow solver, the 3D profiles of impellers will be obtained in order to reach the higher blade loading. Finally, to check the outcome of design process, the current and the modified impellers are analyzed using the full 3D flow solver, CFX. The results are the representatives of about 5 percent enhancement in compressor total pressure ratio.

In this work, an inverse finite element formulation was modified for considering material anisotropy in obtaining blank shape and forming severity of deep drawn orthotropic parts. In this procedure, geometry of final part and thickness of initial blank sheet were known. After applying ideal forming formulations between material points of initial blank and final shape, an equation system was obtained in terms of unknown initial positions on the blank sheet. Initial positions of material points were obtained by solving this equation system. In this algorithm, the Hill's anisotropic plasticity and associated plastic flow rule were used. Strain distribution on the final part was obtained by comparing the initial blank and final part. The method was applied for the simulation of drawing an orthotropic blank to a rectangular cup. Accuracy of the presented method was evaluated by comparing the results with numerical forward method and experiment results.

The purpose of this study is to improve the aerodynamic performance of wind turbine blades, using the Ball-Spine inverse design method. The inverse design goal is to calculate a geometry corresponds to a given pressure distribution on its boundaries. By calculating the difference between the current and target pressure distributions, geometric boundaries are modified so that the pressure difference becomes negligible and the target geometry can be obtained. In this paper, The Ball-Spine inverse design algorithm as a shape modification algorithm is incorporated into CFX flow solver to optimize a wind turbine airfoil. First, the presented inverse design method is validated for a symmetric airfoil in viscous incompressible external flows. Then, the pressure distribution of the asymmetric airfoil of a horizontal wind turbine is modified in such a way that its loading coefficient increases. The lift coefficient and lift to drag ratio for the new modified airfoil get 5% and 3.8% larger than that of the original airfoil. The improved airfoil is substituted by the original airfoil, respectively. in the wind turbine. Finally, the aerodynamic performance of the new wind turbine is calculated by 3-D numerical simulation. The results show that the power factor of the new optimized wind turbine is about 3.2% larger than that of the original one.

This study developed an inverse design algorithm called Ball-Spine Algorithm (BSA) as a quasi-3D method and applied it to the meridional plane of a centrifugal pump impeller in an e ort to improve its performance. In this method, numerical analyses of viscous ow  field in the passage between two blades were coupled with BSA to modify the corresponding hub and shroud geometries. Here, full 3D Navier-Stokes equations were solved on a thin plane of ow instead of solving inviscid, quasi-3D ow equations on the meridional plane. To demonstrate the validity of the present work, the performance of a centrifugal pump was numerically investigated  first and then, it was compared with available experimental data. After defining a target pressure distribution on the hub and shroud surfaces of the ow passage, a new impeller geometry was then obtained in accordance with the modified pressure distribution. The results indicated a good rate of convergence and desirable stability of BSA in the design of rotating ow passages with incompressible, viscous flows. Overall, the proposed design method gave rise to the following major improvements: an increase in static pressure along the streamline, a 5% increase in the pump total head, and delay in the onset of ow cavitation inside the impeller.

A reflectarray optimized through a Generative Adversarial Network (GAN) is demonstrated. This design focuses on the impact of the top layer on the reflection phase and utilizes the correlation between phase distribution and the direction of the reflected beam. Six programmable subcells are optimized to accommodate two incident angle waves simultaneously. Silicon substrate is exploited making the design compatible with integrated circuits. The far-field analysis indicates that for incident angles of 19.471° and 41.81°, as well as their vicinity, the reflectarray effectively redirects the incoming waves to reflect towards near-normal direction to its surface. This suggests a near independence of the deflection angle from the incident angle within a specific angular range, making the proposed reflectarray a planar THz beam collimator. The proposed subcells achieve a reflection phase range of 342°. The return losses for the incident angles of 19.471° and 41.81° are 1.9 dB and 1.4 dB, respectively. For a finite reflectarray measuring 15λ×5λ, the pattern gain and fractional bandwidth are reported as 19.44 dB and 24.8% for the incident angle of 19.471°, and 19.17 dB and 29.9% for the incident angle of 41.81°. This denotes an excellent wideband behavior for the proposed single-layer pixelated reflectarray.

In the present work, an inverse analysis of combined radiation and laminar forced convection heat transfer in a two-dimensional channel with variable cross sections is performed. The conjugate gradient method is used to find the temperature distribution over the heater surface to satisfy the prescribed temperature and heat flux distributions over the design surface. The fluid is considered to be a gray participating medium with absorption, emission and isotropic scattering. The discrete ordinate method is used to solve the radiative transfer equation. The effect of radiation-conduction parameter is studied on the amount of heat transfer from the heater surface.

The shape of the artificial channel sections and their optimal design by artificial intelligence methods can have significant effects on lowering the costs of constructions. In this study, an artificial channel with inverse cycloid and its optimal design by bat algorithm was introduced for the first time. Two schemes of sections were proposed: inverse cycloid without horizontal bed and inverse cycloid with horizontal bed. For optimal designing of proposed section, two scenarios were defined: channel with fixed freeboard and channel with variable freeboard. In both scenarios, Manning equation was used as a constraint and Horton equation was used for considering equivalent roughness. Based on sensitivity analysis, optimal parameters of the proposed algorithm were determined. Bat algorithm has been implemented randomly for each section and for each scenario for fifteen times, and coefficient of variation and speed of convergence were estimated. To find out the accuracy of bat algorithm in the global optimum determination, a comparison between solutions of bat algorithm and lingo software was made. Eventually, results from optimal design of proposed sections were compared with trapezoidal channel, parabolic with horizontal bed channel, ellipsoid channel, and general ellipsoid channel. Results from random runs of bat algorithm indicated that coefficient of variation for defined sections and scenarios were about 0. 0002 to 0. 0013. Convergence curves showed that the algorithm was convergence for all sections and scenarios in 1000 repetition. Findings of bat algorithm and lingo software also demonstrated high accuracy of mentioned algorithm in determination of global optimum. Furthermore, using proposed sections, compared with other common sections, led to 34. 7 percent decrease in construction costs. Among sections and scenarios investigated here, the inverse cycloid under second scenario was found more economical, up to 17. 15 percent.

In this research an inverse design algorithm, called ball-spine algorithm (BSA) is developed on 90-degree bend duct between the radial and axial diffuser of centrifugal compressor with viscous swirling inflow to bend duct. The shape modification process integrates inverse design algorithm and quasi-3D analysis code. For this purpose, Ansys CFX software is used as flow solver and inverse design algorithm is written as code inside it. Shape modification is accomplished for viscous and inviscid flow to check the effect of viscosity on convergence rate. Also, the effect of swirl velocity in shape modification process is investigated by considering increased pressure as the target parameter. The algorithm reliability for swirling flow is verified by choosing different initial geometries. Finally, aerodynamic design of the bend duct with BSA is accomplished to reduce losses in 90-degree bend. Shape modification process is carried out by improving the current wall pressure distribution and applying it to the inverse design algorithm. Results show that convergence rate and stability of BSA are favorable for designing ducts with swirling viscous flow. So the pressure recovery coefficient of the 90-degree bend duct is increased 4%.