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The non-convex tax-aware portfolio optimization problem is traditionally approximated as a convex problem, which compromises the quality of the solution and converges to a local-minima instead of global minima. In this paper, we proposed a non-deterministic meta-heuristic algorithm called Non-linear Activated Beetle Antennae Search (NABAS). NABAS explores the search space at the given gradient estimate measure until it is smaller than a threshold known as “Activation Threshold”, which increases its convergence rate and avoids local minima. To test the validity of NABAS, we formulated an optimization-based tax-aware portfolio problem. The objective is to maximize the profit and minimize the risk and tax liabilities and fulfill other constraints. We collected stock data of 20 companies from the NASDAQ stock market and performed a simulation using MATLAB. A comprehensive comparison is made with BAS, PSO, and GA algorithms. The results also showed that a better-optimized portfolio is achieved with a non-convex problem than a convex problem. © 2022 Elsevier Ltd

This paper discusses the use of thick-film screen-printing process in realization of micro-electro-mechanical systems (MEMS). Two types of screen-printed thick-film MEMS are taken in consideration: screen-printed silicon and screen-printed ceramic MEMS. Silicon MEMS dominate MEMS market and screen-printed silicon MEMS are mostly based on piezoelectric thick films such as lead zirconate titanate (PZT). Key issues that screen-printed silicon MEMS face are compatibility of materials and processes used in their realization. Screen-printed ceramic MEMS are MEMS with free-standing micromechanical structures on top surface of the ceramic substrate and L TCC based ceramic MEMS. Challenges for screen-printed ceramic MEMS are related to compatibility of thick - film compositions, screen printing and micromachining processes used for realization of these fragile microstructures.

High temperature treatment is the key process in formation of thick resistive films. When these complex structures are in question, materials selection, screen-printing process and high temperature treatment are directly responsible for resistor performances. High temperature treatment regulates the space distribution of conducting and glass phase in the resistor. Strict control of conveyor furnace operation, optimum firing profile, adequate peak temperature and dwelling time spent at the peak temperature determine microstructure of the film. Conduction mechanisms present in the film are directly related to resistor performances. In this paper standard resources for tracking micro and macrostructural changes, resistance and noise index measurements, are used in investigation of effects of thermal processing on properties of thick resistive films.

Following the results of cite{Med}, regarding the Aluthge transform of polynomial matrices, the symbolic computation of the Duggal transform of a polynomial matrix $A$ is developed in this paper, using the polar decomposition and the singular value decomposition of $A$. Thereat, the polynomial singular value decomposition method is utilized, which is an iterative algorithm with numerical characteristics. The introduced algorithm is proven and illustrated in numerical examples. We also represent symbolically the Duggal transform of rank-one matrices using cross products of vectors and show that the Duggal transform of such matrices can be given explicitly by a closed formula and is equal to its Aluthge transform.

Temperature sensors are being widely used in various aspects of our lives. One of the most important areas of their application is environmental monitoring. In air velocity measurements resistive temperature detectors are often used. For this reason, as an initial step in development of novel thermo-anemometer that will allow 3D wind speed measurements, a series of Pt resistive film sensors that combine custom made thin-film material and thick-film technology was realized. In this paper these sensors will be presented from design and manufacturing stage to evaluation of sensor performances.

High voltage pulse trimming is the most suitable resistance adjustment method for contemporary thick-film applications that impose stricter requirements on thick-film resistors. In this paper the influence of trimming by energy of high voltage pulses on two thick-film resistor quality indicators that are based on noise index measurements is being examined. Since standard characterization of trimmed thick resistive films is based on the resistance drift with little respect to the nature of observed changes, this paper aims to discuss in more detail how values of both quality indicators, that formally incorporate both transport and low-frequency noise characteristics of the resistor, change with high voltage pulse trimming and whether they can enable evaluation of resistor behavior before and after performed trimming process.

Packaging of microelectromechanical systems (MEMS) strongly affects the device performances. It is the core technology for the advancement of MEMS and is recognized as the next manufacturers challenge for the forthcoming years due to the growing market and stricter requirements. There is a vast diversity of applications and the most of MEMS packaging challenges are application dependent. It is the objective of this paper to review and discuss the most common MEMS packaging challenges. For that reason, five case studies on MEMS pressure sensors, MEMS accelerometers, RF MEMS, MOEMS and BioMEMS are presented for an in-depth illustration.

The measurement of MEMS materials mechanical properties is crucial for the design and evaluation of MEMS devices. It is essential both from the aspect of MEMS device performances, as well as from the reliability aspect. This paper provides a brief overview of commonly used test methods for MEMS materials along with measured material data for MEMS structural materials.

Lead zirconate titanate (PbZrTiO 3 ) and barium titanate (BaTiO 3 ) samples were fabricated using ceramic powder injection molding method (CIM). Piezoelectric CIM samples were characterized and it is shown that obtained properties are satisfactory and comparable to those found in literature. This shows that it is feasibile to synthesise piezoelectric ceramics with good dielectric and piezoelectric properties using CIM method.

Ceramic injection molding was used in production of Mn-Zn ferrite specimens with structural integrity, densities similar to conventionally produced material and satisfactory magnetic properties when compared to magnetic properties of conventionally produced Mn-Zn ferrites. Injection molded material exhibited high green-state strength allowing the production of complex and delicate shapes.

In order to determine possible causes of resistance and noise index changes in thick-film resistors during high- voltage pulse stressing, deterministic model was used. Irreversible micro- and macro-structural changes observed during high- voltage pulse stressing of thick film resistors based on 1, 10 and 100 kOmega/sq compositions were analyzed and performed analysis resulted in determination of primary technological, geometrical and physical parameters responsible for observed changes.

In this paper statistical approach to analysis of mechanically and electrically strained TFRs will be presented using parameters from deterministic model. Noise performances of stained resistors will be explained using redistribution of numbers of contacts and MIM cells as well as adequate contributions of noise due to metallic conduction and noise due to fluctuations in MIM cells to total noise of strained resistor.

In this paper the results from a study of multiple high-voltage pulse stressing effects on resistance and low-frequency noise of thick-film resistors based on resistor composition with sheet resistance of 10kOmega/sq are presented. For the experimental purposes a series of thick-film test resistors with identical geometries were realized and exhibited to two types of tests: multiple series of 10 pulses with amplitude from the 0.5-4.0kV range and multiple series of 10 pulses with 3kV amplitude. Obtained experimental results were analyzed and correlation between resistance and low-frequency noise changes with resistor degradation due to multiple high-voltage pulse stressing is observed. It is shown that low-frequency noise parameters are more sensitive to this kind of resistor stressing than resistance

In this paper the results from a study of simultaneous mechanical and electrical straining effects on performances of conventional thick-film resistors based on resistor composition with sheet resistance of 1kOmega/sq are presented. For experimental purposes a series of thick-film test resistors with different geometries were realized and subjected to simultaneous electrical and mechanical straining using 1.2/50mus pulses in combination with mechanical substrate deflection of 300mum. Obtained experimental results were analyzed and correlation between resistance, noise index and gauge factor changes with resistor degradation due to simultaneous impact of these two types of straining were observed

In this paper a 3D planar random resistor network model as a thick-film resistor model based on percolation theory combined with deterministic model is presented. Thick-film resistors are described as random resistor networks where parameters from deterministic model introduce micro structural characteristics. The percolation site model with double percolation introduces macrostructural characteristics of thick-film resistors into newly developed combined model. The model is illustrated by a computer simulation of thick-film resistor degradation caused by high-voltage pulse stressing. Obtained results are compared with experimental results for thick-film resistors with 10 kOmega/sq and 100 kOmega/sq sheet resistances

A relationship between structural characteristics and noise properties of thick resistive films using noise reduced mobility is presented, proving that noise index measurements can be used as an indicator in thick-film quality and reliability diagnostics. In addition, this analysis can serve as a basis for development of a new diagnostic method for thick resistive films based on noise index measurements.