Volume 66 (2015): Issue 4 (July 2015)

The paper presents a new functional test generation method for processors testing based on genetic algorithms and evolutionary strategies. The tests are generated over an instruction set architecture and a processor description. Such functional tests belong to the software-oriented testing. Quality of the tests is evaluated by code coverage of the processor description using simulation. The presented test generation method uses VHDL models of processors and the professional simulator ModelSim. The rules, parameters and fitness functions were defined for various genetic algorithms used in automatic test generation. Functionality and effectiveness were evaluated using the RISC type processor DP32.

In the development of the voice conversion and personification of the text-to-speech (TTS) systems, it is very necessary to have feedback information about the users’ opinion on the resulting synthetic speech quality. Therefore, the main aim of the experiments described in this paper was to find out whether the classifier based on Gaussian mixture models (GMM) could be applied for evaluation of different storytelling voices created by transformation of the sentences generated by the Czech and Slovak TTS system. We suppose that it is possible to combine this GMM-based statistical evaluation with the classical one in the form of listening tests or it can replace them. The results obtained in this way were in good correlation with the results of the conventional listening test, so they confirm practical usability of the developed GMM classifier. With the help of the performed analysis, the optimal setting of the initial parameters and the structure of the input feature set for recognition of the storytelling voices was finally determined.

This work presents fuzzy backstepping control techniques applied to the load simulator for good tracking performance in presence of extra torque, and nonlinear friction effects. Assuming that the parameters of the system are uncertain and bounded, Algebraic parameters adaptation algorithm is used to adopt the unknown parameters. The effect of transient fuzzy estimation error on parameters adaptation algorithm is analyzed and the fuzzy estimation error is further compensated using saturation function based adaptive control law working in parallel with the actual system to improve the transient performance of closed loop system. The saturation function based adaptive control term is large in the transient time and settles to an optimal lower value in the steady state for which the closed loop system remains stable. The simulation results verify the validity of the proposed control method applied to the complex aerodynamics passive load simulator.

This paper deals with the design and implementation of linear quadratic controller (LQR) for modeling of Ball on Spool. The paper presents the entire process, starting from mathematical model through control design towards application of controller with the use of given hardware platform. Proposed solution by means of REX Control System provides a high level of user comfort regarding implementation of control loop, diagnostics and automatically generated visualization based on HTML5. It represents an ideal example of a complex nonlinear mechatronic system with a lot of possibilities to apply other types of controllers.

Quality and performance of a detection system are the crucial parameters in all nuclear physics experiments. This system serves as a source of all signals and noises to be processed. Better performance, higher amplification and lower noises occurrence simplify subsequent signal analysis. In the field of Mössbauer spectroscopy, the spectrum quality and Mössbauer effect are crucial parameters which are affected especially by the quality of the detection system. These parameters were evaluated for different types of a detection setup. Finally an improvement of the spectrum quality by 15% and Mössbauer effect by 7% has been achieved for the natural iron reference absorber measurement in comparison with previous version of the detection system.

The paper reports on a non-destructive method of reliability prediction for semiconductor lasers diodes GaSb based VCSE (vertical cavity surface emitting). Transport and noise characteristic of forward biased were measured in order to evaluate the new MBE (molecular beam epitaxy) technology. The results demonstrate that the lasers prepared by new MBE technology have higher quality than the samples prepared by using the classic MBE technology.

The properties of magnetic fluids depend on the nanoparticle diameter, their concentration and the carrier liquid. The structural changes in magnetic fluids with different nanoparticle diameter based on transformer oils TECHNOL and MOGUL under the effect of a magnetic field and temperature were studied by acoustic spectroscopy. At a linear and jump changes of the magnetic field at various temperatures a continuous change was observed of acoustic attenuation caused by aggregation of the magnetic nanoparticles to structures. From the anisotropy of acoustic attenuation and using the Taketomi theory the basic parameters of the structures are calculated and the impact of nanoparticle diameters on the size of structures is confirmed.

A new type of transfer logic gates with both electrical and/or optical inputs and electrical outputs are proposed, which can be prepared by thin film technology. The possible realization of different logic functions and non-volatile memory logic arrays are demonstrated. The possible application fields are briefly discussed.

To solve off-grid problem in compressed sensing, a new reconstruction algorithm for complex sinusoids is proposed. The compressed sensing reconstruction problem is transformed into a joint optimized problem. Based on coordinate descent approach and linear estimator, a new iteration algorithm is proposed. The results of experiments verify the effectiveness of the proposed method.