Support Vector Machine State Estimation

The power system state estimator based on the support vector machine (SVM) and the weighted least squares (WLS) method is presented in the paper. The WLS provides state estimations necessary for creating SVM model which is then used for state estimation. The developed algorithm was tested on the IEEE systems, and the performance indicators were calculated in order to compare the accuracy of estimation and the measurement error filtering. The results indicate that the proposed hybrid model outperforms the classical WLS-based state estimation in terms of accuracy and improves measurement error filtering in comparison to the classical estimator.     

A continuation‐based task programming model for C++: design of the Causeway library

There is a big class of problems that requires writing programs in an asynchronous manner. Cloud computing, service‐oriented architectures, multi‐core and heterogeneous systems all require programs to be written with asynchronous components. The necessity of concurrency and asynchronous execution brings in the added complexity of the inversion of control into the system, either through message passing or through event processing. In this paper, we introduce explicit programming language support for asynchronous programming that completely hides inversion of control. The presented programming model defines a common abstraction of the different types of tasks, both synchronous and asynchronous. It defines common imperative control constructs equivalent to those of the host programming language, along with a few more advanced ones for transactional and parallel execution that can universally work for any task type. It allows the programmer to implement the logic of an asynchronous system in a natural way by writing simple, seemingly, synchronous imperative code. We will show that the programs written using this approach are easier to understand by programmers. They are also easier to design automated tests for, and for performing computer‐based static analysis of the program logic. The principles behind this approach were tested in a couple of real‐world systems with worldwide user base. Our experience shows that it makes the complex code with a lot of interdependencies between asynchronously executed tasks easy to write and reason about. Copyright © 2016 John Wiley & Sons, Ltd.     

Modelling effects of S3D visual discomfort in human emotional state using data mining techniques

Multimedia Tools and Applications - In recent years, the rapid development of diverse media has been evident in disparate fields such as consumer electronics, automotive infotainment and healthcare...     

Correlation of hardness and microstructure in unoriented lamellar polyethylene

The local deformation of the lamellar microstructure of isothermally melted crystallized unoriented polyethylene has been investigated using microindentation hardness (MH). The polymer can be visualized as a composite material consisting of hard and weak elements. The former, the lamellae, are considered to consist of mosaic blocks with liquid-like lattice distortions (paracrystallites). The latter are the interlamellar amorphous regions and the mosaic block lateral grain boundaries. The deformation mechanisms beneath the indenter are discussed in the light of current models of plastic deformation. MH is shown to depend on the packing density of the macromolecules in both phases and, as a result, it can be clearly correlated with the macroscopic density of the material. The unit cell expansion and lattice distortions increase in parallel as a consequence of increasing incorporation of chain defects within the lattice. This provokes a conspicuous decrease in the microhardness of the crystals. The increase in lattice distortions is consistent with the concurrent decrease of lamellar thickness and, hence, of the coherently diffracting lattice volume. These results unambiguously emphasize the physical significance of the mosaic block character of the lamellae in determining the micromechanical properties of the material. Finally it is shown that the strain boundary which defines the zone of crystal destruction under the indenter also depends on the average volume of the paracrystallites and on the volume fraction of crystalline material.     

FPGA-based module for SURF extraction

We present a complete hardware and software solution of an FPGA-based computer vision embedded module capable of carrying out SURF image features extraction algorithm. Aside from image analysis, the module embeds a Linux distribution that allows to run programs specifically tailored for particular applications. The module is based on a Virtex-5 FXT FPGA which features powerful configurable logic and an embedded PowerPC processor. We describe the module hardware as well as the custom FPGA image processing cores that implement the algorithm’s most computationally expensive process, the interest point detection. The module’s overall performance is evaluated and compared to CPU and GPU-based solutions. Results show that the embedded module achieves comparable distinctiveness to the SURF software implementation running in a standard CPU while being faster and consuming significantly less power and space. Thus, it allows to use the SURF algorithm in applications with power and spatial constraints, such as autonomous navigation of small mobile robots.     

Geometrical isomerization of polyunsaturated fatty acids in physically refined rapeseed oil during plant‐scale deodorization

The effect of the operating temperature (between 220 and 270 °C) on the formation of trans isomers of linoleic and linolenic acids in physically refined rapeseed oil during deodorization in a plant‐scale semicontinuous tray‐type deodorizer (capacity 10 t/h) was investigated. The industrial procedures of physical refining consisted of a two‐step bleaching and deodorization process. The degree of isomerization of linoleic acid ranged from 0.33 to 4.77% and that of linolenic acid from 4.43 to 45.22% between 220 and 270 °C, respectively. A relation between the logarithm of the degree of isomerization and the deodorization temperature can be approximated by statistically highly significant linear functions for both linoleic and linolenic acids. Oleic acid was resistant to the heat‐induced geometrical isomerization. The values found for the ratio between the degrees of isomerization of linolenic and linoleic acids, slightly decreasing with increasing temperature, were equal to 13.6 and 12.9 at 230 and 240 °C, respectively. Two trans isomers of linoleic acid, exclusively with one double bond isomerized into trans configuration, and four trans isomers of linolenic acid, mostly with one double bond isomerized into trans configuration, were determined in deodorized rapeseed oils. Linolenic acid was observed to be the main source responsible for the formation of nearly all trans fatty acids in physically refined rapeseed oil. At 235 °C, a deodorization temperature considered as a reasonable technological compromise, the content of trans fatty acids in plant‐scale physically refined rapeseed oil was less than 1% of total fatty acids, which would be acceptable for further application.     

Thermal analysis of high‐performance mortar containing burnt clay shale as a partial portland cement replacement in the temperature range up to 1000 °C

Clay shale is a specific type of material that contains a large amount of kaolinite. Burnt clay shale belongs to a large group of pozzolans, and its pozzolanic properties are activated after burning at temperatures similar to those when kaolinite is transformed into metakaolin. In this study, fine powder of burnt clay shale was used for the design of a high‐performance mortar as a partial replacement for portland cement up to 60 wt.%. The prepared specimens were subjected to a thermal analysis by using differential scanning calorimetry, thermogravimetry, and thermodilatometry. The investigation was performed in the temperature range 25–1000 °C. The basic physical and mechanical properties were studied as well. It was demonstrated that it is possible to design and produce a high‐performance mortar containing fine burnt clay shale powder and that an appropriate amount of this replacement is up to 20 wt.%. Copyright © 2016 John Wiley & Sons, Ltd.     

Hydrogen storage in Laves phases: First principles study of electronic structure and formation energies in HfV2 hydrides

We present first principles calculations of the electronic structure, enthalpies of formation and electric field gradients in C15 HfV₂H_x (x = 1, 2, 3, 4). In C15 Laves phases, hydrogen can occupy three possible interstitial positions: 96g, 32e, and 8b. To determine which one of these interstitials is the most favorable for storing hydrogen, enthalpies of formation were calculated for every site, with different concentrations of hydrogen. In order to investigate the change in electronic structure before and after hydrogenation, we calculated the electric field gradients induced by hydrogen on the vanadium, and compared them with the existing nuclear magnetic resonance measurements. This comparison enabled us to study the distribution of hydrogen atoms in the crystal lattice, as well as the occupation of possible interstitials.     

Heat distribution in thermally modified timber

The heat distribution during thermal modification of beech (Fagus sylvatica L.) and spruce (Picea abies L. Karst) wood with dimensions of 80 × 80 × 200 mm³ has been investigated. Heat distribution was continuously measured by thermocouples in longitudinal and transverse directions. Significant temperature gradients occur in the initial phase of the process as well as during the modification phase (set temperature 200 °C for 3 h), where ongoing chemical reactions in wood were taking place. Thus, the temperature in the investigated positions increased to 240 °C (beech) and 215 °C (spruce). The mentioned properties should be taken into account when optimizing the heat treatment process (quality control, energy savings, etc.).