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In this work, the exponential weighted square-of-error functions are exploited for controller design. It is reported that the exponential weight in square-of-error objective function is related to the maximum sensitivity of the process. Therefore, it is possible to control the maximum sensitivity of the process without measuring the frequency response. Moreover, the existing integral-square-error- and integral-time-square-error-based proportional-integral-derivative (PID) tuning rule is modified with the proposed exponential weighted square-of-error functions that allow the user to further tune the maximum sensitivity of the process. The proposed theory is corroborated with the help of a gain optimisation example by the traditional minimisation approach and a PID controller design example by the proposed tuning rule (for the stable/unstable process) and stochastic optimisation approach. [ABSTRACT FROM AUTHOR]

In this paper, a novel vision-based nighttime vehicle detection approach is presented, combining state machines and downhill simplex optimization. In the proposed approach, vehicle detection is modeled as a sequential state transition problem; that is, vehicle arrival, moving, and departure at a chosen detection area. More specifically, the number of bright pixels and their differences, in a chosen area of interest, are calculated and fed into the proposed state machine to detect vehicles. After a vehicle is detected, the location of the headlights is determined using the downhill simplex method. In the proposed optimization process, various headlights were evaluated for possible headlight positions on the detected vehicles; allowing for an optimal headlight position to be located. Simulation results were provided to show the robustness of the proposed approach for nighttime vehicle and headlight detection. [ABSTRACT FROM AUTHOR]

An electromagnetic inversion method is presented to reconstruct the constitutive parameters of an inhomogeneous bianisotropic slab. The measured co- and cross-reflection and transmission coefficients are used to extract the electromagnetic parameters profiles of the inhomogeneous bianisotropic media from the proposed method, using truncated Fourier series expansion and Gravitational Search Algorithm (GSA). GSA is used to improve the speed and accuracy of the optimisation process because of the complexity of inhomogeneous bianisotropic media, highly non-linearity of optimisation problem, and extremely large search space. Finally, the accuracy and robustness of the proposed reconstruction method are validated using some typical examples. [ABSTRACT FROM AUTHOR]

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The present study performs portfolio analysis using a multi-index model in the diagonal form. In a mean-variance framework, an alternative solution to a portfolio optimization problem is derived, providing analytical and computational improvements. This leads to a proof of a crucial functional property of cutoff rates of security performance in the solution, thus providing formal justification for a nonranking procedure of optimal portfolio selection. The robustness of the above functional property, and hence the nonranklng procedure, is demonstrated numerically when the underlying normality assumption of security returns is replaced by a more general assumption of stable Paretian distributions. [ABSTRACT FROM AUTHOR]

In the presence of steering vector (SV) mismatch, a novel iterative variable loading robust adaptive beamforming approach is presented in a new perspective. The proposed method searches for the desired array SV iteratively based on the relationship between the optimal weight vector and the assumed SV of standard Capon beamformer, which avoids any Lagrange multiplier methodology or the convex optimisation methods in each iteration. Simulation results demonstrate the superior performance of the proposed method. [ABSTRACT FROM AUTHOR]

Although the majority of the existing robust adaptive beamformers focus on how to choose an identical loading factor for all eigenvalues, relatively few investigations on variable loading (VL) have been conducted. A low-complexity VL beamformer is proposed in which the beamformer weight vector is deliberately prevented from converging to the noise components. Then inspired by the traditional identical loading method, the loading factor can be set in an ad hoc manner. Numerical results demonstrate the superior performance of the proposed beamformer relative to other existing approaches such as 'identical diagonal loading' and 'robust Capon' beamformers. [ABSTRACT FROM AUTHOR]

The non-unitary joint block diagonalisation (JBD) of a set of given matrices in non-square mixing situation is addressed. To eliminate the degenerate solutions, the JBD problem is reformulated as a multicriteria optimisation model. The resulting algorithm is numerically robust for non-square mixing matrix estimation. Moreover, it outperforms the existing JBD algorithms in terms of convergence rate and stability, which has been verified by simulation results. [ABSTRACT FROM AUTHOR]