A computationally scalable fast intra coding scheme for HEVC video encoder

Multimedia Tools and Applications - The High Efficiency Video Coding (HEVC) adopts 35 intra prediction modes to provide a more precise intra prediction. As a result, HEVC intra coding is much more...     

Decision‐tree‐based methods for differential diagnosis of β‐thalassemia trait from iron deficiency anemia

Several discrimination indices have been proposed to distinct between β‐thalassemia trait (βTT) and iron deficiency anemia (IDA). This study is the first application of tree‐based methods for differential diagnosis of βTT from IDA. One hundred forty‐four patients with hypochromic microcytic anemia aged 18–40 years old from Ayat Hospital of Tehran were recruited. Classification and Regression tree, CHi‐squared Automatic Interaction Detector (CHAID), Exhaustive CHi‐squared Automatic Interaction Detector (E‐CHAID), Quick, Unbiased, Efficient Statistical Tree (QUEST), Classification Rule with Unbiased Interaction Selection and Estimation (CRUISE), and Generalized, Unbiased, Interaction Detection and Estimation (GUIDE) have been used to discriminate the diagnosis. Mean corpuscular volume (MCV) was found as the main predictor in discrimination. All the mentioned tree‐based methods showed acceptable sensitivity, specificity, accuracy, Youden's index, false positive and negative rate, positive and negative predictive values and AUC in differential diagnosis of βTT from IDA. However, Classification Rule with Unbiased Interaction Selection and Estimation revealed more precise classification with an area under the curve value of 0.99. Decision‐tree‐based methods can be used to develop sensitive and accurate diagnostic methods for differentiating βTT from IDA.     

Generating test as a web service (TaaWS) through a method-based attribute grammar

International Journal on Software Tools for Technology Transfer - Service-Oriented Architecture (SOA) is a technology for designing software systems. By using this architecture, new challenges...     

Applying reinforcement learning for web pages ranking algorithms

Ranking web pages for presenting the most relevant web pages to user's queries is one of the main issues in any search engine. In this paper, two new ranking algorithms are offered, using Reinforcement Learning (RL) concepts. RL is a powerful technique of modern artificial intelligence that tunes agent's parameters, interactively. In the first step, with formulation of ranking as an RL problem, a new connectivity-based ranking algorithm, called RL_Rank, is proposed. In RL_Rank, agent is considered as a surfer who travels between web pages by clicking randomly on a link in the current page. Each web page is considered as a state and value function of state is used to determine the score of that state (page). Reward is corresponded to number of out links from the current page. Rank scores in RL_Rank are computed in a recursive way. Convergence of these scores is proved. In the next step, we introduce a new hybrid approach using combination of BM25 as a content-based algorithm and RL_Rank. Both proposed algorithms are evaluated by well known benchmark datasets and analyzed according to concerning criteria. Experimental results show using RL concepts leads significant improvements in raking algorithms.     

Integration of distributed energy resources into low voltage grid: A market-based multiperiod optimization model

This paper develops a multiperiod optimization model for an interconnected micro grid with hierarchical control that participates in wholesale energy market to maximize its benefit (i.e. revenues-costs). In addition to the operational constraints of distributed energy resources (DER) including both inter-temporal and non-inter-temporal types, the adequacy and steady-state security constraints of micro grid and its power losses are incorporated in the optimization model. In the presented model, DER are integrated into low voltage grid considering both technical and economical aspects. This integration as a micro grid can participate in wholesale energy market as an entity with dual role including producer and consumer based on the direction of exchanged power. The developed model is evaluated by testing on a micro grid considering different cases and the results are analyzed.     

Electrospun core-shell nanofibers based on polyethylene oxide reinforced by multiwalled carbon nanotube and silicon dioxide nanofillers: A novel and effective solvent-free electrolyte for lithium ion batteries

Insertion of conductive fillers into solvent-free polymer electrolytes enhances electrochemical behavior of the electrolyte membranes leading to higher ionic conductivity, lower capacity fading, and so on. Although, the presence of the conductive fillers in the polymer matrixes increases the risk of electrical shorting, herein, polyethylene oxide (PEO)-based core-shell nanofibers were prepared via a simple electrospinning method. In the core-shell electrospun fibers, ethylene carbonate (EC) and lithium perchlorate (LiClO₄) were used as a plasticizer and as a lithium salt, respectively. The core component was enwrapped by the PEO/EC/LiClO₄ shell part incorporated with SiO₂ nanoparticles. Various properties of the fabricated membranes were evaluated by changing the ratio of multiwall carbon nanotubes (MWCNTs) in the core part of the nanofibers. The morphology and core-shell structure of the electrospun fibers were studied by FESEM and TEM images. According to FTIR and XRD results, addition of the EC plasticizer and the fillers into the as-spun fibers increased the fraction of free ions and the amorphous regions. From electrochemical impedance spectroscopy studies, the ionic conductivity enhanced by insertion of the plasticizer molecules and the filler particles into the core-shell structures. The highest ionic conductivities of 0.09 and 0.21 mS.cm⁻¹ were obtained for the free-filler and the filler-loaded nanofibrous membranes, respectively. The prepared mats obeyed the Arrhenius behavior ( R²~1 ). Dielectric studies confirmed the obtained data from the ionic conductivities. Furthermore, the capacity residual was enhanced from 69% to 85% by incorporation of the MWCNTs filler into the core component of the electrospun nanofibers. The presented results may facilitate development of versatile nanofibrous membranes embedded with the conductive fillers as solvent-free electrolytes applicable in lithium-ion batteries.     

Experimental study of rotary magnetic field-assisted dry EDM with ultrasonic vibration of workpiece

Dry electrical discharge machining (EDM) is a green machining method which replaces the gas instead of liquid as dielectric medium. Due to the environmentally friendly nature of this method, recently, researchers focused on characterization of this process. In this work, effects of rotary magnetic field and also ultrasonic vibration of workpiece were studied on dry EDM process performance. Conducted experiments were divided in two main stages. At first stage, preliminary experiments were carried out to determine the best tool design in material and geometry points of view by considering the material removal rate (MRR). Also, effect of magnetic field was studied in the first stage. Results of the first stage of experiments indicated that the brass tool with two eccentric holes has the highest MRR rather than the other existing tool. In the second stage of experiments, parametric study on dry EDM process were implemented by using a brass tool with two eccentric holes and by applying rotary magnetic field for all experiments of the second stage. Influences of parameters such as pulse current, pulse on-time, pulse off-time, tool rotational speed, air injection inlet pressure, and especially power of ultrasonic table were studied on MRR, surface roughness (SR), electrode wear rate (EWR), and overcut (OC). Results showed that magnetic field has positive effects on MRR and SR. Also, by application of ultrasonic vibration achieving to superior MRR is feasible. At the end of the work, mathematical models were developed to correlate a relationship between process inputs and main outputs.     

Absolute measurements of radiation damage in nanometer-thick films

The problem of absolute measurements of radiation damage in films of nanometer thicknesses is addressed. Thin films of DNA (～2-160 nm) are deposited onto glass substrates and irradiated with varying doses of 1.5-keV X-rays under dry N(2) at atmospheric pressure and room temperature. For each different thickness, the damage is assessed by measuring the loss of the supercoiled configuration as a function of incident photon fluence. From the exposure curves, the G-values are deduced, assuming that X-ray photons interacting with DNA deposit all of their energy in the film. The results show that the G-value (i.e. damage per unit of deposited energy) increases with film thickness and reaches a plateau at 30±5 nm. This thickness dependence provides a correction factor to estimate the actual G-value for films with thicknesses <30 nm thickness. Thus, the absolute values of the damage can be compared with that of films of any thickness under different experimental conditions.     

The effects of solvent and initiator on anionic ring opening polymerization of ϵ‐caprolactone: synthesis and characterization

Anionic ring opening polymerization of ?‐caprolactone was studied by using different amounts of two potassium activated initiators containing ethylene glycol (EG) and polyhedral oligomeric silsesquioxane (POSS) diol, in tetrahydrofuran and toluene as solvents. The synthesized hydroxyl terminated macromers and linear poly(?‐caprolactone) (PCL) were characterized by proton and carbon nuclear magnetic resonance and gel permeation chromatography (GPC) techniques. Results showed an increase in molecular weight as the monomer/initiator molar ratio increased from 100 to 151 and 202, while the molecular weight distribution (MWD) showed a minimum by monomer concentration increase. Moreover, POSS‐diol‐initiated PCLs showed a higher MWD than the polymers initiated with the EG initiator. This was attributed to the formation of a vesicular structure of POSS diols which was confirmed by optical microscopy. By deconvolution of GPC peaks, the best conditions to synthesize PCL with the narrowest MWD were selected. Finally, the effects of some other parameters were studied in more detail.