Recent Advances in Skin-Inspired Sensors Enabled by Nanotechnology

The highly optimized performance of nature??s creations and biological assemblies has inspired the development of their bio-inspired artificial counterparts that can potentially outperform conventional systems. In particular, the skin of humans, animals, and insects exhibits unique functionalities and properties and has subsequently led to active research in developing skin-inspired sensors. This paper presents a summary of selected work related to skin-inspired tactile, distributed strain, and artificial hair cell flow sensors, with a particular focus on technologies enabled by recent advancements in the nanotechnology domain. The purpose is not to present a comprehensive review on this broad subject matter but rather to use selected work to outline the diversity of current research activities.     

New Recommender Framework: Combining Semantic Similarity Fusion and Bicluster Collaborative Filtering

Collaborative filtering (CF) systems help address information overload, by using the preferences of users in a community to make personal recommendations for other users. The widespread use of these systems has exposed some well‐known limitations, such as sparsity, scalability, and cold‐start, which can lead to poor recommendations. During the last years, a great number of works have focused on the improvement of CF, but they do not solve all its problems efficiently. In this article, we present a new approach that applies semantic similarity fusion as well as biclustering to alleviate the aforementioned problems. The experimental results verify the effectiveness and efficiency of our approach over the benchmark CF methods.     

Semantic tagging and linking of software engineering social content

Social online communities and platforms play a significant role in the activities of software developers either as an integral part of the main activities or through complimentary knowledge and information sharing. As such techniques become more prevalent resulting in a wealth of shared information, the need to effectively organize and sift through the information becomes more important. Top-down approaches such as formal hierarchical directories have shown to lack scalability to be applicable to these circumstanes. Light-weight bottom-up techniques such as community tagging have shown promise for better organizing the available content. However, in more focused communities of practice, such as software engineering and development, community tagging can face some challenges such as tag explosion, locality of tags and interpretation differences, to name a few. To address these challenges, we propose a semantic tagging approach that benefits from the information available in Wikipedia to semantically ground the tagging process and provide a methodical approach for tagging social software engineering content. We have shown that our approach is able to provide high quality tags for social software engineering content that can be used not only for organizing such content but also for making meaningful and relevant content recommendation to the users both within a local community and also across multiple social online communities. We have empirically validated our approach through four main research questions. The results of our observations show that the proposed approach is quite effective in organizing social software engineering content and making relevant, helpful and novel content recommendations to software developers and users of social software engineering communities.     

Synthesis and characterization of polyethylene glycols conjugated to polybutylcyanoacrylate nanoparticles

This study aimed to evaluate the cytotoxicity effects of various polyethylene glycols (PEGs), and construction and characterization of polybutylcyanoacrylate (PBCA) nanoparticles. Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on rat glioma C6 cell line, and PBCA nanoparticles were prepared by emulsion polymerization method. Also, the nanoparticles were characterized by dynamic light scattering and scanning electron microscopy. The findings showed that PEGs were approximately safe and cytotoxicity was inversely proportional with their molecular weights. In addition, the size of nanoparticles were increased with reducing molecular weights of PEGs. PEGs with negligible cytotoxicity and stabilizing functionality were demonstrated in this study.     

Generalized projective synchronization of uncertain chaotic systems with external disturbance

This paper proposes the generalized projective synchronization (GPS) of uncertain chaotic systems with external disturbance via Gaussian radial basis adaptive sliding mode control (GRBASMC). A sliding surface is adopted to ensure the stability of the error dynamics in sliding mode control. In the neural sliding mode controller, a Gaussian radial basis function is utilized to online estimate the system dynamic function. The adaptation law of the control system is derived in the sense of Lyapunov function, thus the system can be guaranteed to be asymptotically stable.The proposed method allows us to arbitrarily adjust the desired scaling by controlling the slave system. It is not necessary to calculate the Lyapunov exponents and the eigen values of the Jacobian matrix, which makes it simple and convenient. Also, it is a systematic procedure for GPS of chaotic systems and it can be applied to a variety of chaotic systems no matter whether it contains external excitation or not. Note that it needs only one controller to realize GPS no matter how much dimensions the chaotic system contains and the controller is easy to be implemented.The proposed method is applied to three chaotic systems: Genesio system, Lur’e like system and Duffing system.     

The persistence and removal of enteric pathogens in constructed wetlands

Sedimentation is thought to be one of the mechanisms of microbial reduction from wetlands used for wastewater treatment. This study compared the occurrence and survival of enteric indicator microorganisms and pathogens in the water column and sediments of two constructed surface flow wetlands in Arizona. On a volume/wet weight basis the concentration of fecal coliforms and coliphage in the water column and sediment was similar. However, on a volume/dry weight basis the numbers were one to two orders of magnitude higher in the sediment. Giardia cyst and Cryptosporidium oocyst concentrations were one to three orders of magnitude greater in the sediment compared to the water column. The die-off rates of all the bacteria and coliphage were greater in the water column than the sediment. The die-off rates of fecal coliforms in the water and sediment were 0.256log(10)day(-1) and 0.151log(10)day(-1), respectively. The die-off rates of Salmonella typhimurium in the water and sediment were 0.345log(10)day(-1) and 0.312log(10)day(-1), respectively. The die-off rates of naturally occurring coliphage in water column and sediment were 0.397log(10)day(-1) and 0.107log(10)day(-1), respectively, and the die-off rates of and PRD-1 in water and sediment were 0.198log(10)day(-1) and 0.054log(10)day(-1), respectively. In contrast Giardia die-off in the sediment was greater compared to the water column. The die-off rates of Giardia in water and sediment were 0.029log(10)day(-1) and 0.37log(10)day(-1), respectively. Coliphage survived the longest of any group of organisms in the sediment and the least in the water column. In contrast Giardia survived best in the water column and least in the sediment.     

Ultrasonic-assisted synthesis of ZnO/NiO nanocomposites and kinetic study of their photocatalytic activity

In the present study, a facile ultrasonic-assisted method was developed for the synthesis of ZnO/NiO nanocomposites. The X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy techniques was applied for characterization of structure, purity, morphology and optical properties of the resultant samples. The photocatalytic performance of the synthesized ZnO/NiO nanocomposites was evaluated by monitoring the photodegradation of Rhodamine B (RhB) under UV light irradiation. Moreover, the influence of various parameters, such as molar percentage of NiO to ZnO, initial RhB concentration, pH of solution and photocatalyst weight was studied. The results show that the photocatalytic activity of the ZnO/NiO nanocomposite was higher than that of pure ZnO and NiO.     

A generalised optimal linear quadratic tracker with universal applications. Part 2: discrete-time systems

Contrastive to Part 1, Part 2 presents a generalised optimal linear quadratic digital tracker (LQDT) with universal applications for the discrete-time (DT) systems. This includes (1) a generalised optimal LQDT design for the system with the pre-specified trajectories of the output and the control input and additionally with both the input-to-output direct-feedthrough term and known/estimated system disturbances or extra input/output signals; (2) a new optimal filter-shaped proportional plus integral state-feedback LQDT design for non-square non-minimum phase DT systems to achieve a minimum-phase-like tracking performance; (3) a new approach for computing the control zeros of the given non-square DT systems; and (4) a one-learning-epoch input-constrained iterative learning LQDT design for the repetitive DT systems.