An agent based system for activity monitoring on network – ABSAMN

Computer network as a force drags its customers to share more and more resources while on the other hand managing such network recourses is a challenging job for an IT professional and perhaps becoming difficult humanly. In this paper, we have proposed an agent based system for activity monitoring on network (ABSAMN) for the monitoring of resources over a network, suitable for network of networks; commonly known as CAN (campus area network). Multi-agent system is a system composed of several agents, collectively capable of achieving goals that are difficult to achieve by an individual agent or monolithic system. We propose the use of multi-agent system to ensure proper system operation by watching for inconsistencies in user activities, node level activity, internet monitoring, and system configuration. The system is fully autonomous and once initialized with the given rules and domain knowledge ABSAMN manages resources on its own with the help of mobile agents. We have evaluated this architecture on the university campus having seven labs equipped with 20–300 number of PCs in various labs. Results were very promising and support the implementation of the solution.     

Removal of toxic contaminants from water by sustainable green synthesised non‐toxic silver nanoparticles

The study describes the synthesis of silver nanoparticles using 21 different plant extracts having medicinal properties. Molecular ultraviolet‐visible spectroscopy shows that the λ _max of nanoparticles synthesised by different plant extracts varied and ranged between 400 and 468 nm. The ultraviolet results revealed that although synthesis of nanoparticles occurred by all plant extracts successfully, their size varies, this was further confirmed by differential light scattering. The synthesised nanoparticles were investigated for their antimicrobial properties. The most promising silver nanoparticles Ocimum sanctum and Artemisia annua assisted were further characterised using transmission electron microscopy and energy dispersive X‐ray spectroscopy (EDX). EDX data confirms that synthesised nanoparticles are highly pure. Further these two plant assisted nanoparticles were studied for chemocatalytic and adsorptive properties. The silver nanoparticles from Ocimum sanctum can catalyse the reduction of 4‐nitrophenol (63%) within 20 min in the presence of NaBH₄, whereas Artemisia annua assisted silver nanoparticles did not show significant chemocatalytic activity. Both the promising nanoparticles can efficiently adsorb textile dyes from aqueous solutions. These synthesised nanoparticles were also exploited to remove microbial and other contaminants from Yamuna River water. The nanoparticles show excellent antimicrobial properties and can be reused repeatedly.Inspec keywords: antibacterial activity, nanofabrication, silver, dyes, light scattering, visible spectra, microorganisms, X‐ray diffraction, transmission electron microscopy, X‐ray chemical analysis, catalysis, nanoparticles, ultraviolet spectra, adsorption, reduction (chemical)Other keywords: sustainable green synthesised nontoxic silver nanoparticles, silver nitrate, molecular ultraviolet–visible spectroscopy, plant assisted nanoparticles, plant extracts, Ocimum sanctum, Artemisia annua, E. coli, C. albicans, plasmon absorbance, differential light scattering, energy dispersive X‐ray spectroscopy, 4‐nitrophenol, chemocatalytic activity, Yamuna River water, antimicrobial properties, time 20.0 min, time 5.0 min to 240.0 hour, size 1.0 nm to 5.0 nm, size 5.0 nm to 20.0 nm, wavelength 400.0 nm to 468.0 nm, NaBH₄ , Ag     

NOx formation in post-flame gases from syngas/air combustion at atmospheric pressure

Species concentration measurements specifically those associated with nitrogen oxides (NO_x) can act as important validation targets for developing kinetic models to predict NO_x emissions under syngas combustion accurately. In the present study, premixed combustion of syngas/air mixtures, with equivalence ratio (Φ) from 0.5 to 1.0 and H₂/CO ratio from 0.25 to 1.0 was conducted in a McKenna burner operating at atmospheric pressure. Temperature and NO_x concentrations were measured in the post-combustion zone. For a given H₂/CO ratio, increasing the equivalence ratio from lean to stoichiometric resulted in an increase in NO and decrease in NO₂ concentration near the flame. Increasing the H₂/CO ratio led to a decrease in the temperature as well as the NO concentration near the flame. Based on the axial profiles above the burner, NO concentration increases right above the flame while NO₂ concentration decreases through NO₂-NO conversion reactions according to the path flux analysis. In addition, the present experiments were operated in the laminar region where multidimensional transport effects play significant roles. In order to account for the radial and axial diffusive and convective coupling to chemical kinetics in laminar flow, a multidimensional model was developed to simulate the post-combustion species and temperature distribution. The measurements were compared against both multidimensional computational fluid dynamics (CFD) simulations and one-dimensional burner-stabilized flame simulations. The multidimensional model predictions resulted in a better agreement with the measurements, clearly highlighting the effect of multidimensional transport.     

LEM-DEM coupling for slope stability analysis

Slope stability analysis is a keen area of interest to researchers of geotechnical engineering and geological hazards. To date, the most popular approach applied in slope engineering design is the limit equilibrium method (LEM). However, for this method, some assumptions are required when obtaining the sliding force and the resistance force on the slide face. The discrete element method (DEM) presents an advantage in the calculation of the interaction forces between adjacent blocks without assumptions. This paper introduces a new slope stability analysis based on coupling of both approaches, herein referred to as LEM-DEM. The main LEM-DEM procedure is to transform the slice model of a slope in LEM into the DEM model and obtain the sliding force and the resistance force to calculate the factor of stability (Fos). The sensitivity analysis of the parameters in DEM, such as normal and shear stiffness, was conducted to illustrate that LEM-DEM suggests higher contact stiffness. A comparison between the Fos values in DEM and LEM-DEM was also conducted to indicate the rationality and advantages of LEM-DEM, especially for a gentle slope with a changing shear force direction in the slice model where the interslice forces in LEM are unreasonable. Furthermore, this study carried out a 3D landslide stability analysis extension, along with the results, for the proposed method.     

Forming-free bipolar resistive switching in nonstoichiometric ceria films

The mechanism of forming-free bipolar resistive switching in a Zr/CeO _x /Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrO _y layer at the Zr/CeO _x interface. X-ray diffraction studies of CeO _x films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeO _x film and in the nonstoichiometric ZrO _y interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).     

Electrochemical properties of titanium arsenate membrane

Membrane potential is a measurable and reliable parameter to characterize the charge property of membrane. Membrane potentials have been measured across polystyrene based titanium arsenate membrane separating various 1:1 electrolytes at different concentrations. Membrane potential data have been used to calculate transference number of ions, mobility, distribution coefficient, charge effectiveness, permselectivity and also to derive the thermodynamically fixed charge density which is an important characteristic governing the membrane phenomena by utilizing the generally accepted theories for the salt concentration dependence of uni-univalent potentials, proposed by Teorell-Meyer-Sievers and Kobatake method and these are compared in order to obtain a relationship for the theoretical data of uni-univalent potentials. The good agreement between the theoretical and the experimental data of uni-univalent potentials proves the applicability of the relationship derived to the membrane system. Kobatake's equation was used under two limiting conditions, namely in the concentration range and in the dilute range. The two limiting forms of Kobatake's equation gave identical values of θ for the membrane taken in this investigation. Membrane is negatively charged (cation selective) and the selectivity increases with dilution. The structure of the membrane was observed with the aid of a scanning electron microscope. The order of fixed charge density for electrolytes used is found to be KCl > NaCl > LiCl.     

Automated diagnosis system for age‐related macular degeneration using hybrid features set from fundus images

Impairment to macula can cause loss of central vision. There are various macular disorders that can affect macular region and if not treated at an early stage can cause irreversible central vision loss. Age‐related macular degeneration (AMD) disorder is one of the most threading macular disorder. Bright lesion, drusens presence in macular region is known as the hallmark of AMD disorder. This bright lesion differentiation from other bright lesion like exudates is important for accurate diagnosis of AMD. Focus of this article is automated diagnosis of affected macular region by applying a hybrid features set containing textural, color, and structural/shape features for more accurate detection of AMD at an early stage using fundus images. These features also help to distinguish drusens from exudates. The proposed algorithm at first stage, detect macular region from input fundus image and then perform features extraction based on textural pattern, edge, and structural properties of macular region to classify abnormal macula from normal macula. For classification, we have used support vector machine (SVM), K‐nearest neighbor and neural networks but SVM classifier achieves high accuracy. The proposed algorithm is tested on publicly available STARE and locally available AFIO datasets. Attained sensitivity, specificity, and accuracy of our proposed system are 97.5%, 95% and 95.45%, respectively, when applied on STARE dataset. When we have applied our proposed system on AFIO dataset, we have attained sensitivity, specificity, and accuracy of 93.3%, 92% and 92.34%, respectively.     

Evaluation of <Emphasis Type="Italic">h</Emphasis>-index,its variants and extensions based on publication age &amp; citation intensity in civil engineering

The scientific community has proposed diversified set of parameters to rank researchers, including publications, citations, h-index, different variants and extensions of h-index. However, there is a debate in the scientific Community which index ranks authors in a better way. Current state-of-the-art depicts that these indices are evaluated on imaginary case scenarios and small datasets. Furthermore, these indices are evaluated on different datasets, making it difficult to grasp the contribution and importance of each index over the others. To analyze the individual behavior of each index, these indices should comprehensively be evaluated on some extensive data set. This study emphasizes on the scrutiny of h-index, some of its variants and extensions to rank authors. These indices are evaluated using a comprehensive data set of Civil Engineering field. For the evaluation of results obtained from these indices, first correlation was calculated among indices. There exists weak correlation between various indices, which demonstrates that the author’s rankings acquired from these indices are not identical. Secondly, occurrences of awardees are checked in all ranked lists. The prestigious award winners of four Civil Engineering societies are considered as a benchmark. In top 10% of ranked list, maximum 47% of the awardees were brought by Wu-index. Overall, none of the index succeeded in bringing 100% awardees to the top rankings. Highest number of awardees on top of all ranked lists are found to be from ACI (American Concrete Institute), which shows ACI might be dependent on these indices for its criterion to honor awards.     

The impact of raindrop drift in a three-dimensional wind field on a radar–gauge rainfall comparison

There are many causes for the discrepancies between weather radar and rain gauges, and among these, displacement of raindrops due to wind drift – which is especially a problem with high-spatial resolution weather radar – is largely ignored in the published literature. This is mainly due to the lack of high-resolution three-dimensional wind fields and feasible treatment of the raindrop size distribution (DSD). In this study, a new systematic approach is proposed to explore the radar–gauge relationship under the wind influence. The mass-weighted mean diameter of raindrops is derived for each radar grid from the DSD data. The reanalysis project ERA-40 data of the European Centre for Medium-range Weather Forecasts (ECMWF) are used to drive the numerical weather research and forecasting (WRF) model to generate high-resolution hourly three-dimensional wind fields. Trajectories and displacements of raindrops are then computed using a three-dimensional motion equation from the given radar beam height to the ground surface. Based on the radar rainfall surface interpolated by the bicubic spline method, the correlation of the radar–gauge pairs is used to validate the results. A case study with 20 storm events in the Brue catchment in South West England is chosen to evaluate the proposed scheme. It has been found that when wind drift is taken into account, the correlation coefficient in hourly gauge–radar comparisons can be enhanced by up to 30% and the average correlation coefficient for an event can be improved by 10%. However, there are still some situations in which the scheme fails to work, indicating the complexity and uncertainties in tackling this challenging problem. Further studies are needed to explore why those cases cause problems to the scheme and how it could be improved to cope with them.     

Improving cascading menu selections with adaptive activation areas

Cascading menus are the most commonly used hierarchical menus in graphical user interfaces (GUIs). These menus, however, tend to have elongated paths with corner steering, which can result in navigation difficulties. To resolve the corner steering problem, most current cascading menus implement an explicit time delay between the cursor entering or leaving a parent menu item and posting/unposting the associated menu. In this paper, we present adaptive activation-area menus (AAMUs), a technique to improve cascading menu performance by providing a localized triangular activation area between the menu and the child submenu. This triangular activation area aims to overcome the corner steering problem by permitting quick diagonal navigation without imposing a time delay.We describe four experiments designed to refine and validate the AAMU technique. Our first experiment shows that AAMUs improve item selection performance in comparison to traditional menus and a number of competing techniques, including gesture-based menus and enlarged activation-area menus (EMUs). Our second and third experiments reveal, however, that in a searching task, where the user has to look through multiple submenus to find the target, the basic AAMU design suffers from a “cursor trapping” problem, where the user has to move the cursor out of the activation area prior to exploring another submenu. An evaluation of an improved AAMU design shows that it is as fast as or faster than traditional menus and EMUs for both selection and searching tasks.