Noise analysis of double gate composite InAs based HEMTs for high frequency applications

Microsystem Technologies - The quantitative analysis of microwave noise available in the double gate (DG) high electron transistors of mobility (HEMT) is reported in this paper. For this analysis,...     

Effect of test method and crack size on the fracture toughness of a chain-silicate glass-ceramic

The fracture toughness of a canasite glass-ceramic with a highly acicular, interlocked grain structure was measured by a number of different methods. The values at room temperature obtained by the chevron-notch, short-bar and notched-beam methods ranged from 4 to 5 M Pa m^–1/2, well above literature values for other glass-ceramics. Similar values of toughness were obtained by the fracture of bars with indentation cracks introduced with loads ranging from 1.96 to 400 N, but only for crack sizes >200 m, with lower values for cracks of smaller size. The toughness values obtained by the direct measurement of the size of the indentation cracks were appreciably lower than the values obtained by all other methods over the total range of indentation loads and corresponding crack size. SEM fractography showed that the surface within the indentation cracks was appreciably smoother than the surrounding fracture surface. The high values of fracture toughness were attributed to the combined mechanisms of crack-deflection and microcrack-toughening due to the stress-enhanced creation of microcracks caused by the residual stresses which arise from the thermal expansion anisotropy of the canasite monoclonic crystal structure. The strong negative temperature dependence of the fracture toughness suggests that at room temperature microcrack toughening represents the primary contributing mechanism to the fracture toughness. The combined effects of crack-deflection and microcrack-toughening can lead to the development of glass-ceramics with greatly improved resistance to crack propagation.     

Faceless identification based on temporal strips

This paper first presents a novel approach for modelling facial features, Local Directional Texture (LDT), which exploits the unique directional information in image textures for the problem of face recognition. A variant of LDT with privacy-preserving temporal strips (TS) is then considered to achieve faceless recognition with a higher degree of privacy while maintaining high accuracy. The TS uses two strips of pixel blocks from the temporal planes, XT and YT, for face recognition. By removing the reliance on spatial context (i.e., XY plane) for this task, the proposed method withholds facial appearance information from public view, where only one-dimensional temporal information that varies across time are extracted for recognition. Thus, privacy is assured, yet without impeding the facial recognition task which is vital for many security applications such as street surveillance and perimeter access control. To validate the reliability of the proposed method, experiments were carried out using the Honda/UCSD, CK+, CAS(ME)² and CASME II databases. The proposed method achieved a recognition rate of 98.26% in the standard video-based face recognition database, Honda/UCSD. It also offers a 81.92% reduction in the dimension length required for storing the extracted features, in contrast to the conventional LBP-TOP.

     

Hash-Indexing Block-Based Deduplication Algorithm for Reducing Storage in the Cloud

Cloud storage is essential for managing user data to store and retrieve from the distributed data centre. The storage service is distributed as pay a service for accessing the size to collect the data. Due to the massive amount of data stored in the data centre containing similar information and file structures remaining in multi-copy, duplication leads to increase storage space. The potential deduplication system doesn’t make efficient data reduction because of inaccuracy in finding similar data analysis. It creates a complex nature to increase the storage consumption under cost. To resolve this problem, this paper proposes an efficient storage reduction called Hash-Indexing Block-based Deduplication (HIBD) based on Segmented Bind Linkage (SBL) Methods for reducing storage in a cloud environment. Initially, preprocessing is done using the sparse augmentation technique. Further, the preprocessed files are segmented into blocks to make Hash-Index. The block of the contents is compared with other files through Semantic Content Source Deduplication (SCSD), which identifies the similar content presence between the file. Based on the content presence count, the Distance Vector Weightage Correlation (DVWC) estimates the document similarity weight, and related files are grouped into a cluster. Finally, the segmented bind linkage compares the document to find duplicate content in the cluster using similarity weight based on the coefficient match case. This implementation helps identify the data redundancy efficiently and reduces the service cost in distributed cloud storage.     

Commodified science and social wellbeing

This paper explores the increasing trend towards the commodification of public research and development (R&D) and the impact of this on social wellbeing. In many developed countries, the changes introduced by governments to funding mechanisms for universities and public research institutions has led to a fundamental shift in the focus of public R&D. The focus has shifted from creating useful public, codifiable knowledge to creating a knowledge commodity driven by commercial imperatives. Although there may be an economic argument to be made for the virtues of such change, we argue here that the potential costs to social wellbeing have been largely, and dangerously, ignored.

A survey: Ant Colony Optimization based recent research and implementation on several engineering domain

Ant Colony Optimization (ACO) is a Swarm Intelligence technique which inspired from the foraging behaviour of real ant colonies. The ants deposit pheromone on the ground in order to mark the route for identification of their routes from the nest to food that should be followed by other members of the colony. This ACO exploits an optimization mechanism for solving discrete optimization problems in various engineering domain. From the early nineties, when the first Ant Colony Optimization algorithm was proposed, ACO attracted the attention of increasing numbers of researchers and many successful applications are now available. Moreover, a substantial corpus of theoretical results is becoming available that provides useful guidelines to researchers and practitioners in further applications of ACO. This paper review varies recent research and implementation of ACO, and proposed a modified ACO model which is applied for network routing problem and compared with existing traditional routing algorithms.     

Structural and luminescence enhancement properties of Eu3＋/Ag nanocrystallites doped SiO2-TiO2 matrices

We reported here the structural and optical characterisation of silver nanocrystallites/Eu3+ :SiO2-TiO2 matrices synthesised through sol-gel route. Structural characterisations were done by using energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM) and transmission electron microscopy (TEM) measurements and optical characterisations were performed by absorption and emission spectroscopy. The TEM and XRD measurements confirmed the presence of nanocrystals. A broad absorption band was observed due to surface plasmon resonance of silver nanocrystals. The effect of silver nanocrystals on the emission spectrum of Eu3+ doped SiO2-TiO2 matrices was discussed. An attempt was made to explain this fluorescence enhancement by invoking phenomena such as energy transfer, asymmetry ratio, surface plasmon, surface roughness, crystallinity and grain boundary. Our analysis, based on the experimental results, suggested that all the phenomena except crystallinity and grain boundary had favourable effects on fluorescence enhancement. We also estimated the relevant parameters associated with the phenomena that affected the fluorescence emission from the Eu3+ ions in the matrix. It was seen that the theoretical estimate of fluorescence enhancement agreed well with the experimental estimate.     

Glycolipids improve lutein bioavailability and accumulation in eyes in mice

Intestinal carotenoid absorption is greatly affected by dietary factors. In this study, it was hypothesized that lipids with varying functional groups may influence differentially lutein bioavailability. Hence, the influence of glyco‐, phospho‐, neutral, crude (mixture of lipids) lipids, or mixed micelles (control) on the percent lutein micellarization in vitro and its postprandial plasma, liver, and eye response in mice were investigated. Results show that the percent micellarization of lutein with crude lipids and glycolipids were higher (91.4 and 45.7%) than control, while no significant difference was found between phospho‐ and neutral lipids. The mean plasma response of lutein was higher for crude‐ (6 times), glyco‐ (3 times), phospho‐ (2.7 times), and neutral (2 times) lipid than control (12.4 ± 1.18 nmol/mL 8 h^?1) group. Lutein levels (pmol/g) in liver were higher in crude (7.4 ± 1) and phospho‐ (3.6 ± 0.8) lipid groups while in eyes it was higher in glyco‐ (54.0) and neutral (21.2) lipid groups than control. The influential effect of glyco‐ and phospholipids may be due to smaller micellar size (glyco‐upto 3.43 µm, phospho‐ upto 5.78 µm) than the neutral lipids (upto 66 µm). Ingestion of lutein with glycolipid or phospholipids may improve lutein bioavailability. Practical applications: The findings of the present study will be useful in nutritional and biomedical applications for feeding lutein with specific lipid combinations to achieve enhanced lutein absorption. Specifically, feeding diet/emulsion with lutein and glyco‐ and phospholipid combination may reduce the risk of macular degeneration, owing to the influential effect of these lipids on intestinal absorption of lutein.     

Enhanced α-Mn2O3 nanorods synthesized by one-pot hydrothermal route for supercapacitors

Journal of Materials Science: Materials in Electronics - Pseudo-capacitors are the emerging energy storage devices which forms a bridge between batteries and conventional capacitors. In the present...     

Soft Computing Techniques for the Prediction and Analysis of Compressive Strength of Alkali-Activated Alumino-Silicate Based Strain-Hardening Geopolymer Composites

Silicon - A futuristic class of concrete that has ductile nature with zeroed cement and eco-friendly materials is popularly known as Engineered Geopolymer Composites (EGC). Research on...