Adaptive Control for State Synchronization of Nonlinear Haptic Telerobotic Systems with Asymmetric Varying Time Delays

In this paper, we introduce a new adaptive controller design scheme for nonlinear telerobotic systems with varying time delays where the delays and their variation rates are unknown. The designed controller has the ability to synchronize the state behaviors of the local and the remote robots. In this paper, asymptotic stability in the presence of varying time delays is of interest. Using the proposed controller, asymptotic stability of the bilateral telerobotic system subject to any bounded yet unknown varying delay with a bounded yet unknown rate of change can be guaranteed. Besides the varying time delay, the proposed adaptive controller has the ability to adapt to the parameter variations in the local and the remote robots’ dynamics. It is shown that position and velocity errors between the local and the remote manipulators converge to the zero asymptotically, thus ensuring teleoperation transparency. Experimental and simulation results with a pair of PHANToM haptic devices and a pair of planar manipulators under varying time delays in the communication channel demonstrate the effectiveness of the proposed scheme.     

Strategic signalling and awards: Investigation into the first decade of AIS best publications awards

Professional organizations for academics such as the Academy of Management and Association for Information Systems (AIS) create best publications awards to honour and promote exemplary contributions that align with the core values and priorities of their distinct fields. Despite the strategic importance of awards, researchers rarely investigate meaningful patterns implicit in the contribution characteristics of award-winning articles. We conduct a reconstructive study of the 10-year history of the AIS Best Publications Awards by outlining a framework that reveals contribution characteristics, demographic patterns, and citation histories of the award-winning articles. Comparing the AIS results to a complete sample of MIS Quarterly paper-of-the-year articles (1993–2015) demonstrates consistent patterns implicit in IS articles that win best publications awards. We develop a model that explains both how these awards shape patterns and discusses what changes might be needed as the field confronts new realities. Our analyses reinforce the importance of taking strategic actions to support the continuous development of the field and advance literature on change and evolving trends in academic fields.     

Standalone noise and anomaly detection in wireless sensor networks: A novel time-series and adaptive Bayesian-network-based approach

Wireless sensor networks (WSNs) consist of small sensors with limited computational and communication capabilities. Reading data in WSN is not always reliable due to open environmental factors such as noise, weakly received signal strength, and intrusion attacks. The process of detecting highly noisy data is called anomaly or outlier detection. The challenging aspect of noise detection in WSN is related to the limited computational and communication capabilities of sensors. The purpose of this research is to design a local time-series-based data noise and anomaly detection approach for WSN. The proposed local outlier detection algorithm (LODA) is a decentralized noise detection algorithm that runs on each sensor node individually with three important features: reduction mechanism that eliminates the noneffective features, determination of the memory size of data histogram to accomplish the effective available memory, and classification for predicting noisy data. An adaptive Bayesian network is used as the classification algorithm for prediction and identification of outliers in each sensor node locally. Results of our approach are compared with four well-known algorithms using benchmark real-life datasets, which demonstrate that LODA can achieve higher (up to 89%) accuracy in the prediction of outliers in real sensory data.     

Pattern synthesize of a cylindrical conformal array antenna by PSO algorithm

Pattern synthesize of conformal array antennas is often a challenging problem. Various optimization algorithms such as genetic, particle swarm optimization (PSO), and invasive weed optimization have already been used for pattern synthesizing of conformal arrays. In this paper, a focused beam is synthesized for a quarter cylindrical conformal array antenna using the PSO algorithm with small computations. The desired pattern is a focused beam at θ = 90° and ? = 45° with 10° beamwidth in elevation and 15° beamwidth in azimuth with ?20 dB side‐lobe level. This method can be used in general for synthesizing arbitrary desired patterns and array geometries.     

A novel ACO–GA hybrid algorithm for feature selection in protein function prediction

Protein function prediction is an important problem in functional genomics. Typically, protein sequences are represented by feature vectors. A major problem of protein datasets that increase the complexity of classification models is their large number of features. Feature selection (FS) techniques are used to deal with this high dimensional space of features. In this paper, we propose a novel feature selection algorithm that combines genetic algorithms (GA) and ant colony optimization (ACO) for faster and better search capability. The hybrid algorithm makes use of advantages of both ACO and GA methods. Proposed algorithm is easily implemented and because of use of a simple classifier in that, its computational complexity is very low. The performance of proposed algorithm is compared to the performance of two prominent population-based algorithms, ACO and genetic algorithms. Experimentation is carried out using two challenging biological datasets, involving the hierarchical functional classification of GPCRs and enzymes. The criteria used for comparison are maximizing predictive accuracy, and finding the smallest subset of features. The results of experiments indicate the superiority of proposed algorithm.     

Synthesis,characterization, thermal and optical properties of soluble polyimides derived from an unsymmetrical diamine

A new unsymmetrical diamine monomer, 2,4‐diaminophenyl [4′‐(2′′,6′′‐diphenyl‐4′′‐pyridyl)phenyl]ether, was successfully synthesized by nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with 4‐(2′,6′‐diphenyl‐4′‐pyridyl) phenol. The diamine monomer was characterized by FTIR, ¹H and ¹³C NMR, and elemental analysis techniques and used for the preparation of novel polyimides (PIs) by reaction with commercially available tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs with inherent viscosities ranged from 0.43 to 0.48 dL/g were readily soluble in many organic solvents and afforded tough and flexible films by solution casting. These polymers exhibited T_gs between 237 and 294°C, and 10% weight loss temperatures in excess of 500°C with up to 56% char yield at 600°C in air. Their maximum fluorescence emission in dilute (0.2 g/dL) NMP solution appeared at 450 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Controlled Growth of Conductive AlN Thin Films by Plasma-Assisted Reactive Evaporation

Metallurgical and Materials Transactions A - In this work, the growth of conductive AlN thin films by plasma-assisted reactive evaporation at different filament-to-substrate distances was presented...     

Inhibitory effect of magnetic iron‐oxide nanoparticles on the pattern of expression of lanosterol 14α ‐demethylase (ERG11) in fluconazole‐resistant colonising isolate of Candida albicans

Fluconazole‐resistant Candida albicans is a big scary reality. The authors assessed the antifungal effects of magnetic iron‐oxide nanoparticles on fluconazole‐resistant colonising isolate of C. albicans and determined the expression of ERG11 gene, protein sequence similarity and ergosterol content. C. albicans isolates were characterised and fluconazole resistance is recognised using World Health Organization''s WHONET software. Susceptibility testing of magnetic iron‐oxide nanoparticles against fluconazole‐resistant colonising isolate of C. albicans was performed according to Clinical and Laboratory Standards Institute guidelines. The expression patterns of ERG11 and protein sequence similarity were investigated. Ergosterol quantification has been used to gauge the antifungal activity of magnetic iron‐oxide nanoparticles. The findings indicated that 93% of C. albicans isolates were resistant to fluconazole. Magnetic iron‐oxide nanoparticles were presented activity against fluconazole‐resistant colonising isolate of C. albicans with minimum inhibitory concentration at 250–500 µg/ml. The expression level of ERG11 gene was downregulated in fluconazole‐resistant colonising isolate of C. albicans. The results revealed no differences in fluconazole‐resistant colonising isolate of C. albicans by comparison with ERG11 reference sequences. Moreover, significant reduction was noted in ergosterol content. The findings shed a novel light on the application of magnetic iron‐oxide nanoparticles in fighting against resistant C. albicans.Inspec keywords: microorganisms, biochemistry, molecular biophysics, antibacterial activity, iron compounds, proteins, cellular biophysics, nanoparticles, drugs, geneticsOther keywords: albicans isolates, magnetic iron‐oxide nanoparticles, fluconazole‐resistant colonising isolate, fluconazole resistance, ERG11, candida albicans, protein sequence similarity, ergosterol content, WHONET, ergosterol quantification, susceptibility testing, antifungal activity, gene expression     

Impact of Freezing Process on Salt Diffusivity of Seafood: Application to Salmon (Salmo salar) Using Conventional and Pressure Shift Freezing

The depression of the melting temperature of ice under pressure permits to obtain a rapid freezing of foods. The expected benefit lies in reduced water diffusion from the intra- toward the extracellular media, resulting in a reduced drip loss during thawing. Beside, the modification of the cellular structure induced by ice formation may affect the mass diffusivity of the flesh. In the present study, salmon was used as a model food. Slabs of salmon (1-cm thick) were frozen using blast air and pressure shift freezing at 200 MPa. The impact of the freezing process on the mass diffusivity of salt was evaluated using an aqueous solution (NaCl, 3% w/w). Results indicate that the effective mass diffusivity was slightly increased in comparison to non-frozen flesh when a rapid freezing process was used. This may be attributed to a change in the permeability of cell membranes caused by freezing and high pressure.     

Modeling and performance of a forced flow solar collector/regenerator using liquid desiccant

A forced flow solar collector/regenerator is one of the effective ways of regenerating the weak liquid solution in an open cycle liquid desiccant air conditioner using solar energy. In this system, the weak solution flows over the absorber plate of a tilted collector/regenerator as a thin liquid film. The forced air stream, which flows parallel or counter to the solution film, removes the moisture which is evaporated from the liquid solution due to absorption of solar energy. The absorber plate of the collector/regenerator is blackened and glazed to enhance the solar energy absorption and protect it from the environment. To evaluate the thermal performance of the solar collector/regenerator, a computer model has been developed using calcium chloride as the desiccant. A parametric analysis of the system has been performed to calculate the rate of evaporation of water from the solution as a function of the system variables and the climatic conditions.