Modeling and analysis of an FC/UC hybrid vehicular power system using a wavelet-fuzzy logic based load sharing and control algorithm

Fuel cell (FC) systems are potentially promising candidates as alternative energy sources for use in vehicular applications. The natural advantages of hybrid power sources may be effectively utilized to improve the efficiency and dynamic response of a vehicular system. Fuel cell (FC) and ultra-capacitor (UC) based hybrid power systems appear to be very promising for satisfying high energy and high power requirements for vehicular applications. In this paper, a FC/UC hybrid vehicular power system using a wavelet based load sharing and fuzzy logic based control algorithm is proposed. While wavelet transforms are suitable for analyzing and evaluating the dynamic load demand profile of a hybrid electric vehicle (HEV), the use of fuzzy logic controller is appropriate for the hybrid system control. The mathematical and electrical models of the hybrid vehicular system are developed in detail and simulated using MATLAB^®, Simulink^® and SimPowerSystems^® environments.     

Energy management of an FC/UC hybrid vehicular power system using a combined neural network-wavelet transform based strategy

An energy management strategy (EMS) is one of the most important issues for the efficiency and performance of a hybrid vehicular system. This paper deals with a neural network and wavelet transform based EMS proposed for a fuel cell/ultra-capacitor hybrid vehicular system. The proposed method combines the capability of wavelet transform to treat transient signals with the ability of auto-associative neural network supervisory mode control. The main originality of the paper is related with the application of neural network instead of another intelligent control method, fuzzy logic, which is presented in the recent publication of the authors, and the combination of neural network-wavelet transform approaches. Then, the effectiveness comparison of both methods considering one of the most important points in a vehicular system, fuel consumption (or hydrogen consumption), is realized. The mathematical and electrical models of the hybrid vehicular system are developed in detail and simulated using MATLAB^®, Simulink^® and SimPowerSystems^® environments.     

Catalytic oxidation of phenol in aqueous solutions

The objective of this work is to investigate catalyst systems for the oxidation of phenol in water in a batch autoclave. The main experimental variables are the type and the composition of the catalyst, the catalyst loading, temperature, oxygen partial pressure, initial phenol concentration and the stirrer speed. Commercial catalysts were used. Experimental work was conducted in two different laboratories. In one laboratory, the catalysts tested were 35% CuO+65% ZnO; 5–15% CuO+85–95% Al₂O₃; 26% CuO+74% Cu Chromite. In the other laboratory, the catalysts tested included 35% CuO+65% ZnO; 5–10% Ba₂CO₃+<5% C+30–40% CuO+60–70% ZnO; and 8–15% Al₂O₃+1–5% C+35–45% CuO+40–50% ZnO. With some of these catalysts depending on the operating conditions, complete phenol conversion could be obtained within 90 min. Under certain experimental conditions, the reaction underwent an induction period after which there was a transition to a much higher activity regime. The induction period may be due to an autocatalytic reaction system or to a very slow rate of formation of hydroquinone and catechol which then readily oxidize to o- and p-benzoquinone. An increase in the temperature and the oxygen partial pressure decreased the induction period, which increased as the catalyst to phenol ratio increased. 26% CuO+74% Cu Chromite and 8–15% Al₂O₃+1–5% C+35–45% CuO+40–50% ZnO were found to be the most active catalysts.     

Spherical Coding Algorithm for Wavelet Image Compression

In recent literature, there exist many high-performance wavelet coders that use different spatially adaptive coding techniques in order to exploit the spatial energy compaction property of the wavelet transform. Two crucial issues in adaptive methods are the level of flexibility and the coding efficiency achieved while modeling different image regions and allocating bitrate within the wavelet subbands. In this paper, we introduce the ldquospherical coder,rdquo which provides a new adaptive framework for handling these issues in a simple and effective manner. The coder uses local energy as a direct measure to differentiate between parts of the wavelet subband and to decide how to allocate the available bitrate. As local energy becomes available at finer resolutions, i.e., in smaller size windows, the coder automatically updates its decisions about how to spend the bitrate. We use a hierarchical set of variables to specify and code the local energy up to the highest resolution, i.e., the energy of individual wavelet coefficients. The overall scheme is nonredundant, meaning that the subband information is conveyed using this equivalent set of variables without the need for any side parameters. Despite its simplicity, the algorithm produces PSNR results that are competitive with the state-of-art coders in literature.     

Analysis and Design of Low-Cost Bit-Serial Architectures for Motion Estimation in H.264/AVC

Variable block-size motion estimation (VBSME) process occupies a major part of computation of an H.264 encoder, which is usually accelerated by bit-parallel hardware architectures with large I/O bit width to meet real-time constrains. However, such kind of architectures increase the area overhead and pin count, and therefore will not be suitable for area-constrained electronic consumer designs such as small portable multimedia devices. This paper addresses this problem by proposing two area efficient least significant bit (LSB) bit-serial architectures with small pin numbers. Both designs take advantage of data reusing technique in different ways for sum of absolute differences (SAD) computation and reading reference pixels, leading to a considerable reduction of memory bandwidth. The first architecture propagates the partial SAD and sum results and broadcasts the reference pixel rows whereas the second design reuse the SAD of small blocks and has a reconfigurable reference buffer leading to a better memory bandwidth when using hardware parallelism. The proposed designs benefit from several optimization techniques including an efficient serial absolute difference architecture, word length reduction by parallelism, bit truncation, mode filtering, and macroblock (MB) level subsampling, which significantly enhance their performances in terms of silicon area, throughput, latency, and power consumption. The first and second designs can support full search VBSME of 720?×?480 video with 30 frames per second (fps), two reference frames, and [?16, 15] search range at a clock frequency of 414 MHz with 29.28 k and 31.5 k gates, respectively.     

A generic framework for optimizing performance metrics by tuning parameters of clustering protocols in WSNs

Wireless Networks - Wireless sensor network (WSN) is a key technology trend in emerging internet of things paradigms which are commonly used for application areas such as smart-cities, smart-grids,...     

In-situ Single Chamber Arc Sputtering Process for Ycd0.3Ba2Cu3O7-δ Superconducting Thin Films

Superconducting YCd _0.3 Ba ₂ Cu ₃ O _7- thin films have been deposited in-situ onto single crystal MgO substrates using a DC arc-sputtering process. The depositions were carried out in a single chamber deposition system equipped with two target holders. The films deposited at the optimum condition exhibited strong (00l) orientation with a high peak intensity. The best electrical properties were achieved to be 90K for T _c , 81K for T _zero and the transport critical current density J _c =675 A/ cm ² at 77K and 2.3×10 ³ A/cm ² at 4.2K for the sample deposited at the optimum conditions.     

Optimization to optimization (OtoO): optimize monarchy butterfly method with stochastics multi-parameter divergence method for benchmark functions and load frequency control

Engineering with Computers - In this paper, the dynamical modeling and behavior analysis of the inverse boundary Stefan problem which promising the understanding of modeling brain tumor treatment,...     

A warning on how to implement anonymous credential protocols into the information card framework

Unlinkability is a privacy feature supported by those multi-party security protocols allowing anonymous users’ credential exchanges among different organizations. Proper signature schemes, based on discrete logarithms, must be used in order to guarantee the above requirements as well as selective disclosure of information. In this paper, we highlight that whenever a concrete architecture based on the above protocols is implemented, some aspects concerning how to manage the association between bases of discrete logarithms and attributes used in attribute certificates should be carefully considered, in order to guarantee that unlinkability really holds. We show that the problem is concrete by testing that the state-of-the-art implementation suffers from the above problem. A general solution is also proposed.