Sharif Digital Repository

HAp and HAp/ZrO2 composite coatings were successfully electrodepesited on 316L stainless steel substrates in the solutions containing ZrO2 particles at different concentrations. The effects of ZrO2 content on characteristics of the coatings were investigated using X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM) and bonding strength test. Polarization and electrochemical impedance spectroscopy measurements were carried out in order to evaluate corrosion behavior of the coatings. In-vitro test in SBF and further SEM observations were performed to examine bioactivity of the coatings. HAp/ZrO2 composite coatings showed better... 

Electricity industry is ongoing towards reregulation worldwide. Some new market issues that experienced in other commodities markets are suggested to be exercised in electricity markets. Electricity and ancillary services pricing under different schemes are such issues. Pricing mechanism can be applied via several sequential markets. A day-ahead market associated with joint energy and ancillary services dispatch is used as a benchmark for contingency reserves option pricing. This paper proposed a new methodology aimed to derive the option pricing for contingency reserves as a major part of ancillary services in restructured power systems  

Deep learning has received much attention as of the most powerful approaches for multimodal representation learning in recent years. An ideal model for multimodal data can reason about missing modalities using the available ones, and usually provides more information when multiple modalities are being considered. All the previous deep models contain separate modality-specific networks and find a shared representation on top of those networks. Therefore, they only consider high level interactions between modalities to find a joint representation for them. In this paper, we propose a multimodal deep learning framework (MDLCW) that exploits the cross weights between representation of... 

This paper describes a solution-based technique for fabrication of varistor grade composite nanopowders. The method consists of coating major varistor dopants on the surface of the ZnO nanoparticles. As a result, a homogenous mixture of dopants and ZnO nanoparticles will be achieved. TEM results indicated that a composite layer of dopants with the average particle size of 9 nm on the surface of ZnO nanoparticles has been successfully prepared. Sintering of the coated powders was performed in temperatures as low as 850 °C and final specimens with average particle size of 900 nm and density of 98.5% were achieved. In comparison to conventional mixing, varistors prepared from coated nanopowders... 

Purpose: The aim of this study was to compare diffusion tensor imaging (DTI) isotropic map (p-map) with current radiographically (T 2/T 2 -FLAIR) methods based on abnormal hyper-signal size and location of glioblastoma tumor using a semi-automatic approach. Materials and methods: Twenty-five patients with biopsy-proved diagnosis of glioblastoma participated in this study. T 2, T 2 -FLAIR images and diffusion tensor imaging (DTI) were acquired 1 week before radiotherapy. Hyper-signal regions on T 2, T 2 -FLAIR and DTI p-map were segmented by means of semi-automated segmentation. Manual segmentation was used as ground truth. Dice Scores (DS) were calculated for validation of semiautomatic... 

Introduction: Cerebellar ataxia is a common symptom of multiple sclerosis (MS), particularly in progressive forms, where gait and balance problems are the most debilitating symptoms. Exercise training is a critical component of rehabilitation in managing equilibrium dysfunction, and stationary bicycling is a safe, feasible, and effective method to reduce the symptom. Clinical walking performance tests are typically used to assess gait in these patients. However, gait analysis technologies are more sensitive and accurate at detecting subtle and subclinical changes. The purpose of this study was to determine the changes in gait parameters in MS patients with ataxic gait after using a... 

Question answering (QA) systems have reached human-level accuracy; however, these systems are not robust enough and are vulnerable to adversarial examples. Recently, adversarial attacks have been widely investigated in text classification. However, there have been few research efforts on this topic in QA. In this article, we have modified the attack algorithms widely used in text classification to fit those algorithms for QA systems. We have evaluated the impact of various attack methods on QA systems at character, word, and sentence levels. Furthermore, we have developed a new framework, named RobustQA, as the first open-source toolkit for investigating textual adversarial attacks in QA...