PAV and the ROC convex hull

Classifier calibration is the process of converting classifier scores into reliable probability estimates. Recently, a calibration technique based on isotonic regression has gained attention within machine learning as a flexible and effective way to calibrate classifiers. We show that, surprisingly, isotonic regression based calibration using the Pool Adjacent Violators algorithm is equivalent to the ROC convex hull method. Editor: Johannes Fürnkranz.     

Fluidized Bed Device for Plastic Granules Triboelectrification

The study of the triboelectrification process is the key factor to the successful industrial application of electrostatic separation in the field of plastics recycling. Therefore, the aim of the present work is to evaluate an original device for the laboratory study of this process. The original design of the fluidized bed type triboelectrification device has the following distinctive features: (i) transparent walls to observe the fluidization process and the particles moving in the triboelectrification module; (ii) air distributors with different mesh apertures correlated with granule size; (iii) quick replacement of the triboelectrification Plexiglas chamber with other metallic (aluminium, copper) or nonmetallic chambers (polyvinyl chloride—PVC, polyethylene—PE, and polyethylene terephthalate—PET); (iv) possibility of independent operation, for granule charge measurement or integrated operation, for the electrostatic separation experiments using a free-fall electrostatic separator. The results of charge measurement experiments pointed out the different triboelectric behaviour of two types of granules (polystyrene and low-density polyethylene) in contact with the walls of the device. The electrostatic separation experiments carried out on a binary mixture of mm-size polystyrene/polyethylene granules confirmed the effectiveness of the triboelectrification device.     

Simultaneous single-loop multimaterial and multijoint topology optimization

As the aerospace and automotive industries continue to strive for efficient lightweight structures, topology optimization (TO) has become an important tool in this design process. However, one ever-present criticism of TO, and especially of multimaterial (MM) optimization, is that neither method can produce structures that are practical to manufacture. Optimal joint design is one of the main requirements for manufacturability. This article proposes a new density-based methodology for performing simultaneous MMTO and multijoint TO. This algorithm can simultaneously determine the optimum selection and placement of structural materials, as well as the optimum selection and placement of joints at material interfaces. In order to achieve this, a new solid isotropic material with penalization-based interpolation scheme is proposed. A process for identifying dissimilar material interfaces based on spatial gradients is also discussed. The capabilities of the algorithm are demonstrated using four case studies. Through these case studies, the coupling between the optimal structural material design and the optimal joint design is investigated. Total joint cost is considered as both an objective and a constraint in the optimization problem statement. Using the biobjective problem statement, the tradeoff between total joint cost and structural compliance is explored. Finally, a method for enforcing tooling accessibility constraints in joint design is presented.     

Effect of precursor concentration on structural,morphological and opto-electric properties of ZnO thin films prepared by spray pyrolysis

Sprayed ZnO films were grown on glass substrate at 400 °C using zinc chloride as precursor with different molar concentrations varying from 0.05 to 0.2 M. X-ray diffraction patterns reveal that ZnO films are polycrystalline with hexagonal wurtzite structure with preferred orientation in (002) plane. Optical measurements show that transmittance reaches a maximum value of 95% in the visible region for ZnO films prepared from precursor with 0.05 M concentration. The films obtained from the precursor with 0.1 M concentration have the highest electrical conductivity and photocurrent values.     

Super-orthogonal space-time trellis codes with eight dimensional phase-shift keying signal constellations

We propose a new method of designing super-orthogonal space-time trellis codes (SOSTTCS) by labeling each state transition of the trellis diagram with an ordered pair of 2×2 orthogonal matrices instead of only a single 2×2 orthogonal matrix. An 8D instead of a 4D signal constellation is thus used for modulation and the delay elements of the trellis encoder are 4T instead of 2T, where T is the 2D symbol duration. Therefore, at the receiver, the sequence decoding using Viterbi algorithm requires two times less frequent updating of the branch metrics. We investigate by computer simulation the performance of the new sosttcs compared to sosttcs designed by the known method. The frame error rate (fer) and the bit error rate (ber) simulation results show that the performance of the new sosttcs is practically as good as that of the sosttcs of similar complexity designed along classical lines, with the advantage that the number of arithmetic and logic operations performed by the decoder per time unit is smaller, which is crucial in high data-rate applications.     

Template-grown NiFe/Cu/NiFe nanowires for spin transfer devices

We have developed a new reliable method combining template synthesis and nanolithography-based contacting technique to elaborate current perpendicular-to-plane giant magnetoresistance spin valve nanowires, which are very promising for the exploration of electrical spin transfer phenomena. The method allows the electrical connection of one single nanowire in a large assembly of wires embedded in anodic porous alumina supported on Si substrate with diameters and periodicities to be controllable to a large extent. Both magnetic excitations and switching phenomena driven by a spin-polarized current were clearly demonstrated in our electrodeposited NiFe/Cu/ NiFe trilayer nanowires. This novel approach promises to be of strong interest for subsequent fabrication of phase-locked arrays of spin transfer nano-oscillators with increased output power for microwave applications.     

Superior neuroprotective effects of cerebrolysin in heat stroke following chronic intoxication of Cu or Ag engineered nanoparticles. A comparative study with other neuroprotective agents using biochemical and morphological approaches in the rat

The possibility that cerebrolysin, a mixture of several active fragments of neurotrophic factors and peptides induces neuroprotection following nanoparticles induced exacerbation of brain damage in heat stroke was examined in a rat model. For this purpose, the therapeutic efficacy of Cerebrolysin (2.5 or 5 ml/kg) recommended for stroke treatment was used in comparison with other drugs in standard doses recommended for such therapy in clinical situations e.g., levetiracetam (44 mg/kg), pregabalin (200 mg/kg), topiramate (40 mg/kg,i.p.) and valproate (400 mg/kg). Rats subjected to 4 h heat stress in a biological oxygen demand (BOD) incubator at 38 degrees C (Rel Humid 45-47%; Wind vel 22.4 to 25.6 cm/sec) developed profound behavioral symptoms of heat stroke e.g., hyperthermia, profuse salivation, prostration and gastric ulcerations in the stomach. These rats also exhibited marked brain pathology at this time. Thus, breakdown of the blood-brain barrier (BBB) to proteins associated with brain edema formation could be seen in these heat stressed rats as compared to control groups. The edematous brain areas showed profound neuronal damage and/or distortion in large areas of the neuropil. These pathological symptoms were further exacerbated in Cu or Ag nanoparticles treated group (50-60 nm particle size, 50 mg/kg, i.p./day for 7 days) after identical heat stress on the 8th day. Pretreatment with cerebrolysin (2.5 ml/kg, i.v.) daily for 3 days in normal rats before heat stress significantly reduced the behavioral stress symptoms and the breakdown of the BBB function, edema formation and neuronal injuries. However, the magnitude and intensity of these neuroprotective effects were much less intense in all other drug treated rats after similar heat stress. On the other hand, almost double dose of cerebrolysin (5 ml/kg) was needed to achieve comparable neuroprotection in nanoparticles treated animals after heat stress. Whereas, double dose of all other compounds was much less effective in inducing neuroprotection in nanoparticles treated heat-exposed animals. These observations are the first to show that cerebrolysin exerts the most superior neuroprotective effects in heat stress as compared to other neuroprotective agents on brain pathology in normal and in nanoparticles treated group. Furthermore, cerebrolysin in double dose was the most effective in inducing neuroprotection in nanoparticles treated heat exposed rats on brain pathology as compared to double doses of other drugs. Taken together, our results show that cerebrolysin has the most superior neuroprotective effects on brain pathology in heat stroke in both normal and nanoparticles treated rats as compared to other contemporary neuroprotective agents, not reported earlier.     

System of nano-silver inkjet printed memory cards and PC card reader and programmer

This work describes the development of inkjet printed, low-cost memory cards, and complementary pair of memory card reader and card reader/programmer for PCs. This constitutes a complete system that can be used for various applications. The memory cards are manufactured by inkjet printing nano-silver ink on photo paper substrate. The printed memory structures have an initial high resistance that can later be programmed to specific values representing data on the cards, the so called Write Once Read Many (WORM) memories. The memory card reader measures the resistance values of the memory cells and reads it back to the computer by USB connection. Using multiple resistance levels that represent different states it is possible to have a larger number of selectable combinations with fewer physical bits compared to binary coding. This somewhat counters one of the limitations of resistive memory technology that basically each cell needs one physical contact. The number of possible states is related to the resolution of the reader and the stability of the WORM memory.     

Symbolic Mapping of Loop Programs onto Processor Arrays

In this paper, we present a solution to the problem of joint tiling and scheduling a given loop nest with uniform data dependencies symbolically. This challenge arises when the size and number of available processors for parallel loop execution is not known at compile time. But still, in order to avoid any overhead of dynamic (run-time) recompilation, a schedule of loop iterations shall be computed and optimized statically. In this paper, it will be shown that it is possible to derive parameterized latency-optimal schedules statically by proposing a two step approach: First, the iteration space of a loop program is tiled symbolically into orthotopes of parametrized extensions. Subsequently, the resulting tiled program is also scheduled symbolically, resulting in a set of latency-optimal parameterized schedule candidates. At run time, once the size of the processor array becomes known, simple comparisons of latency-determining expressions finally steer which of these schedules will be dynamically selected and the corresponding program configuration executed on the resulting processor array so to avoid any further run-time optimization or expensive recompilation. Our theory of symbolic loop parallelization is applied to a number of loop programs from the domains of signal processing and linear algebra. Finally, as a proof of concept, we demonstrate our proposed methodology for a massively parallel processor array architecture called tightly coupled processor array (TCPA) on which applications may dynamically claim regions of processors in the context of invasive computing.     

Roasted Sunflower Kernel Paste (Tahini) Stability: Storage Conditions and Particle Size Influence

Sunflower tahini faces quality problems due to the tendency of oil to exudate, causing accelerated rancidity and low marketability. In this study, the colloidal and oxidative stability of different trimodal particle size distributions of sunflower tahini (cumulative volume percentages of small, middle and large class populations of 9.61–16.67, 43.03–55.03 and 47.36–28.3) was evaluated during storage at three different temperatures. Decreasing sample particle size decreased the sunflower tahini colloidal stability. The coarsest prototype, being the most stable tahini in terms of oil separation, was included in the oxidative stability storage test together with a commercial tahini. The peroxide values of the studied sunflower tahini samples increased significantly (p < 0.05) with storage time, irrespective of storage temperature, while the p‐anisidine values showed an irregular pattern. Considering 30‐meq O₂/kg as a PV limit, the commercial tahini showed good oxidative stability as it was under this when stored 3 months at 4 °C, 2 months at room temperature and 1 month at 40 °C. The coarsest tahini sample was under the limit when stored 2 months at 4 °C, 1 month at room temperature and 2 weeks at 40 °C. Particle size was shown to be an essential parameter for controlling sunflower tahini's overall stability.