Evaluating the Efficiency of CBAM-Resnet Using Malaysian Sign Language

The deaf-mutes population is constantly feeling helpless when others do not understand them and vice versa. To fill this gap, this study implements a CNN-based neural network, Convolutional Based Attention Module (CBAM), to recognise Malaysian Sign Language (MSL) in videos recognition. This study has created 2071 videos for 19 dynamic signs. Two different experiments were conducted for dynamic signs, using CBAM-3DResNet implementing ‘Within Blocks’ and ‘Before Classifier’ methods. Various metrics such as the accuracy, loss, precision, recall, F1-score, confusion matrix, and training time were recorded to evaluate the models’ efficiency. Results showed that CBAM-ResNet models had good performances in videos recognition tasks, with recognition rates of over 90% with little variations. CBAM-ResNet ‘Before Classifier’ is more efficient than ‘Within Blocks’ models of CBAM-ResNet. All experiment results indicated the CBAM-ResNet ‘Before Classifier’ efficiency in recognising Malaysian Sign Language and its worth of future research.     

Failure Analysis of HAZ Cracking in Low C–CrMoV Steel Weldment

This case study describes the failure analysis of steel nozzle in which cracking was observed after a circumferential welding process. The nozzle assembly was made from low C–CrMoV alloy steel that was subsequently single pass butt welded using gas tungsten arc welding. No cracks were found in visual inspection of the welds; however, X-ray radiography showed small discontinuous cracks on the surface in the area adjacent to weld bead, i.e. heat affected zone. The welding of nozzle parts made of same material was a routine process and this type of cracking did not occur in the past. Therefore, it became essential to determine the root cause of the failure. A detailed investigation including visual examination, non-destructive testing, optical microscopy, microhardness measurements and residual stress measurements were carried out to find out the primary cause of failure and to identify actions required to avoid its reoccurrence in future. Results of the investigation revealed that the principal cause of failure was the presence of coarse untempered martensite in the heat affected zone due to localized heating. The localized heating was caused by high welding heat input or low welding speed and resulted in the high transformation stresses. These transformation stresses combined with the thermal stresses and the constraint conditions to cause intergranular brittle fracture.     

Microstructural evolution during high-temperature oxidation of spark plasma sintered Ti2AlN ceramics

Microstructures of Ti₂AlN ceramics synthesized and simultaneously consolidated from starting mixtures of Ti/Al/TiN powders by spark plasma sintering (SPS) were characterized using X-ray diffraction, scanning electron microscopy, focused ion beam (FIB) and transmission electron microscopy (TEM). When sintered for 10 min at 1300 °C, nearly single-phase Ti₂AlN ceramics with elongated (∼22 × 6 × 6 μm) grains were obtained. After sintering for 10 min at 1200 °C and chemical etching, Ti₂AlN nanowhiskers (150-200 nm dia., 1-5 μm long) were exposed in pores coexisting with TiAl, TiN and Ti₂AlN grains. FIB-TEM studies revealed single-crystal Ti₂AlN nanowhiskers in a TiAl matrix with orientation relationship [1 1 −2 0]_H//[−1 0 1]_γ, (0 0 0 1)_H//(1 1 1)_γ, γ = TiAl, H = Ti₂AlN. The nanowhiskers are believed to form by diffusion of TiN into TiAl during SPS and to be exposed during the chemical etch. Microstructural development during high-temperature oxidation of dense Ti₂AlN ceramics for 1 h at <1200 °C involves gradual formation on the surface of layered microstructures containing anatase, rutile and α-Al₂O₃. After 1 h at >1200 °C, more complex layered microstructures containing Al₂TiO₅, rutile, α-Al₂O₃ and continuous voids layers form. After heating to 1100 °C for 1 h and cooling to room temperature, planar defects are observed in surface TiO₂ grains identified as stacking faults bounded by partial dislocations. After heating for 1 h at 1400 °C and cooling to room temperature, cracks propagate in TiO₂ grains. It is believed that planar defects and cracks arise from stress generation in the oxide scale. Thermal stresses formed on cooling may arise from thermal expansion mismatch of phases (TiO₂, Al₂O₃ and Al₂TiO₅) in the oxide scale, the high anisotropy of thermal expansion in Al₂TiO₅ and thermal expansion mismatch between the oxide scale and Ti₂AlN substrate. Growth stresses formed during the isothermal oxidation treatment may arise from the volume changes associated with oxidation reactions of Ti₂AlN. An oxidation mechanism for Ti₂AlN ceramics is proposed, which involves initial reaction with atmospheric oxygen to form oxide phases, demixing of the mixed oxide phases, void formation due to the Kirkendall effect and gaseous NO_x release. Oxidation of Ti₂AlN <1200 °C with 1 h hold times is limited, while above this temperature the oxide scale grows rapidly, and Ti₂AlN ceramics undergo heavy oxidation.     

Characterization of Carnobacterium maltaromaticum LMA 28 for its positive technological role in soft cheese making

Carnobacterium maltaromaticum is a lactic acid bacterium isolated from soft cheese. The objective of this work was to study its potential positive impact when used in cheese technology. Phenotypic and genotypic characterization of six strains of C. maltaromaticum showed that they belong to different phylogenetic groups. Although these strains lacked the ability to coagulate milk quickly, they were acidotolerant. They did not affect the coagulation capacity of starter lactic acid bacteria, Lactococcus lactis and Streptococcus thermophilus, used in dairy industry. The impact of C. maltaromaticum LMA 28 on bacterial flora of cheese revealed a significant decrease of Psychrobacter sp. concentration, which might be responsible for cheese aging phenomena. An experimental plan was carried out to unravel the mechanism of inhibition of Psychrobacter sp. and Listeria monocytogenes and possible interaction between various factors (cell concentration, NaCl, pH and incubation time). Cellular concentration of C. maltaromaticum LMA 28 was found to be the main factor involved in the inhibition of Psychrobacter sp. and L. monocytogenes.     

Progressive mean control chart is not a special case of an exponentially weighted moving average control chart

The progressive mean (PM) statistic is based on a simple idea of accumulating information of each subgroup by calculating the average progressively. Its weighting structure is based on a subgroup number that changes arithmetically, which makes the PM chart unique and efficient compared with the existing classical memory control charts. In a recent article (see reference 1), it was claimed that the PM chart is a special case of the exponentially weighted moving average (EMWA) chart. In this article, it is shown that even though the PM statistic can be written in the form of an EWMA statistic, the variance of the PM statistic is different from that of the EWMA statistic. Consequently, the limits of the PM chart are different from that of the EWMA chart. Therefore, it is found that the PM chart is not a special case of the EWMA chart; hence, the claim in reference 1 is incorrect. Furthermore, it is pointed out in this paper that no adaptive property in the weighting parameter of the PM statistic exists, further contradicting the claim in reference 1.     

Robust LCMV Beamformer for Direction of Arrival Mismatch Without Beam Broadening

Wireless Personal Communications - In this work, we propose a new and efficient algorithm to mitigate the signal look direction error problem in adaptive beamforming without broadening the main...     

A new ElGamal-like cryptosystem based on matrices over groupring

In this paper, we have developed a new ElGamal-like public key cryptosystem based on the matrices over a groupring. The underlying hard problem for this cryptosystem is the conjugacy search problem. That is, we have replaced the exponentiation of elements by conjugacy. This makes the key generation step more efficient. We also talk about different security aspects against known attacks. The proposed scheme is found to be secure against known plaintext attack when encryption uses a different random key for every new plaintext.

     

Visible-light-active silver- , vanadium-codoped TiO<Subscript>2</Subscript> with improved photocatalytic activity

Optimized doped TiO₂ is necessary for efficient visible light harvesting and widening the applications spectrum of TiO₂-based materials. Titanium dioxide doped with silver and/or vanadium has been synthesized by one-pot hydrothermal method without post-calcination. Codoping induced visible light absorption while maintaining the photoactive anatase phase along with good crystallinity. Synthesized products are in nanometer range and possess high specific surface area. Having nearly spherical morphology, the particles are distributed and the particle size estimated from TEM observation is in accordance with the XRD results. Spectroscopic investigations reveal that the doped atoms successfully entered the TiO₂ lattice modifying the band structure. The narrowed band gap allows visible light photons for absorption, and the codoped samples displayed enhanced visible light absorption among the synthesized samples. Photodegradation performance evaluated under visible light irradiations showed that silver- , vanadium-codoped TiO₂ have the best visible light photocatalytic activity attributed to stable configuration, high visible light absorption, coupling between silver and vanadium and their optimal doping concentration.     

A novel chaotic image encryption technique based on multiple discrete dynamical maps

The propagation of information over insecure communication system is one of the most important aspect of digitally advance era. The electronic information is travels in form of binary bits. The secrecy of these digital contents is one of the most important issue of existing world. In this article, we have utilized multiple chaotic iterative maps in order to propose a novel image encryption technique. The suggested encryption added confusion as well as diffusion in offered scheme which is one of the most fundamental aspect of encryption technique. We have tested our anticipated scheme against different performances analysis and compared it with already existing results. The designed scheme is capable of providing an excellent privacy to digital images.