Development of new encryption system using Brownian motion based diffusion

Multimedia Tools and Applications - A new cryptographic model is proposed incorporating intertwining logistic map based confusion process and two dimensional Brownian Motion based diffusion...     

A multilevel hybrid anomaly detection scheme for industrial wireless sensor networks

Real-time sensing plays an important role in ensuring the reliability of industrial wireless sensor networks (IWSNs). Sensor nodes in IWSNs have inherent limitations that give rise to different anomalies in the network. These anomalies can lead to disastrous and harmful situations or even serious system failures. This article presents a formulation to the design of an anomaly detection scheme for detecting the anomalous node along with the type of anomaly. The proposed scheme is divided into two major parts. First, spatiotemporal correlation within a cluster is obtained for the normal and anomalous behavior of sensor nodes. Second, the multilevel hybrid classifier is used by combining the sequential minimal optimization support vector machine (SMO-SVM) as a binary classifier with optimally pruned extreme learning machine (OP-ELM) as a multiclass classifier for detection of an anomalous node and type of anomalies, respectively. Mahalanobis distance-based lightweight K-Medoid clustering is used to build a new set of training datasets that represents the original training dataset, by significantly reducing the training time of a multilevel hybrid classifier. Results are analyzed using standard WSN datasets. The proposed model shows high accuracy, i.e., 94.79% and detection rate, i.e., 94.6% with a reduced false positive rate as compared to existing hybrid methods.     

Iodine‐Mediated Copper‐Catalyzed Efficient α‐C(sp2)‐Thiomethylation of α‐Oxoketene Dithioacetals with Dimethyl Sulfoxide in One Pot

The direct α‐Csp² H functionalization and thiomethylation of α‐oxoketene dithioacetals (DTAs) has been accomplished with dimethyl sulfoxide (DMSO) in the presence of iodine and a copper(I) salt for the first time. A prerequisite is the in situ iodination of the α‐Csp² atom of dithioacetals that could offer other reaction channels. The operationally simple one‐pot protocol includes region‐defined consecutive iodination and sulfenylation of the challenging α‐Csp² H bond of dithioacetals employing cheap and readily available reagents. DMSO here plays a dual role as thiomethyl source and solvent.

     

Characteristic study,its identification and self-tuned approach to control hydro-power plants

The water time constant and mechanical time constant greatly influences the power and speed oscillations of hydro-turbine-generator unit. This paper discusses the turbine power transients in response to different nature and changes in the gate position. The work presented here analyses the characteristics of hydraulic system with an emphasis on changes in the above time constants. The simulation study is based on mathematical first-, second-, third- and fourth-order transfer function models. The study is further extended to identify discrete time-domain models and their characteristic representation without noise and with noise content of 10 & 20 dB signal-to-noise ratio (SNR). The use of self-tuned control approach in minimising the speed deviation under plant parameter changes and disturbances is also discussed.     

On the structuring of systems with fuzzy relations

Interpretive structural modeling for binary relations and fuzzy structural modeling for fuzzy relations restrict the relation defined on the system being modeled to be either transitive or fuzzy semitransitive. Also, no cycles are allowed in the formal sense. In this paper, we present a new generalized fuzzy structural modeling (GFSM) methodology which does not impose any such restriction on the relation defined on the system while allowing the inclusion of cycles of any order. Algorithms are presented for deriving a minimum-edge connection matrix, automatic detection of hierarchies and cycle condensation. Examples are presented to demonstrate the working of the GFSM algorithms.     

Physically Based Sound Synthesis for Large-Scale Virtual Environments

By offering a natural, intuitive interface with the virtual world, auditory display can enhance a user's experience in a multimodal virtual environment and further improve the user's sense of presence. However, compared to graphical display, sound synthesis has not been well investigated because of the extremely high computational cost for simulating realistic sounds. The state of the art for sound production in virtual environments is to use recorded sound clips that events in the virtual environment trigger, similar to how recorded animation sequences in the earlier days generated all the character motion in the virtual world. In this article, we describe several techniques for accelerating sound simulation, thereby enabling realistic, physically based sound synthesis for large-scale virtual environments     

Removal of textile basic dye from aqueous solutions using sawdust as bio‐adsorbent

The ability of low cost bio‐adsorbent sawdust to remove basic dye (methylene blue) from aqueous solution is investigated using it in two different forms: in raw form and in chemically treated (with sulphuric acid) form. The effect of contact time, dye concentration, adsorbent dose and the kinetics of adsorption were studied in batch experiments. At neutral pH and 4?gm/l of chemically activated and raw sawdust adsorbents, removal of 98.12% and 97.18% of methylene blue dye (at 100?mg/l concentration) from the aqueous solution, was the best result obtained during study. An average percentage removal difference of less than 5%, between two adsorbents was achieved under different conditions in the experiments. The data fit well in Freundlich isotherm.     

Practical aspects of polymerization of D,L-Lactide initiated with tetraphenyltin

Melt polymerization conditions for D ,L -Lactide initiated with tetraphenyltin were studied with regard to polymer molecular weight. The combined effect of time and temperature on polymer molecular weight and degree of conversion of D ,L -Lactide is described. Polymerization at constant initiator concentrations resulted in a narrow scattering of reproducible molecular weight values. The presence of air/moisture and other impurities during the melt polymerization most likely have a deterimental effect on molecular weight. After a short induction period the rather slow polymerization of D ,L -Lactide resulted in a maximal molecular weight followed by an almost constant value of molecular weight. © 1995 John Wiley & Sons, Inc.     

An Efficient Tetrabutylammonium Fluoride (TBAF)‐Catalyzed Three‐Component Synthesis of 3‐Substituted Indole Derivatives under Solvent‐Free Conditions

An expedient and efficient one‐pot three‐component synthesis of 3‐substituted indoles has been developed by the reaction of indoles, active methylene compounds and aldehydes using a catalytic amount of tetrabutylammonium fluoride under solvent‐free conditions.