A Bluetooth Routing Protocol Using Evolving Fuzzy Neural Networks

In this paper, a routing protocol which utilizes the characteristics of Bluetooth technology is proposed for Bluetooth-based mobile ad hoc networks. The routing tables are maintained in the master devices and the routing zone radius for each table is adjusted dynamically by using evolving fuzzy neural networks. Observing there exists some useless routing packets which are helpless to build the routing path and increase the network loads in the existing ad hoc routing protocols, we selectively use multiple unicasts or one broadcast when the destination device is out of the routing zone radius coverage of the routing table. The simulation results show that the dynamic adjustment of the routing table size in each master device results in much less reply time of routing request, fewer request packets and useless packets compared with two representative protocols, Zone Routing Protocol and Dynamic Source Routing.     

Germanium Nanoclusters in Germanosilicate Glass Heat-Treated in Hydrogen

The formation of Ge nanoclusters in bulk and thin-film germanosilicate glass samples prepared by vapor deposition techniques and then heat-treated in molecular hydrogen at 800°C was studied by Raman scattering and optical spectroscopy. The results demonstrate that the formation of Ge nanoclusters is accompanied by a substantial increase in the concentration of oxygen-deficient germanium centers and the formation of OH groups. A mechanism of nanocluster formation is proposed. The effects of different process parameters on nanocluster growth in the course of preform fabrication and fiber drawing are examined.     

Analysis of Wave Motions in One Crystallographic Plane of a Cubically Anisotropic Medium

Based on the system of the equations of motion of an elastic medium with tetragonal anisotropy, a comparative analysis of the curves of inverse velocities and the elastic-wave fronts in one crystallographic plane of a cubically anisotropic body has been made with the use of sections of the surfaces of inverse velocities and wave surfaces.     

Wear Resistance of Coatings from Self‐Fluxing Alloys after Laser Doping under Dry Friction Conditions

The wear resistance of Ni–Cr–B–Si–C coatings after laser treatment with a doping covering under dry friction conditions has been investigated. The microstructure of coatings after fusion by a gas burner and a laser beam and the roughness and waviness parameters of the friction surfaces before and after wear have been investigated.     

On certain classes of exact solutions of Einstein equations for rotating fields in conventional and nonconventional form

Using the symmetry reduction approach we have herein examined, under continuous groups of transformations, the invariance of Einstein exterior equations for stationary axisymmetric and rotating case, in conventional and nonconventional forms, that is a coupled system of nonlinear partial differential equations of second order. More specifically, the said technique yields the invariant transformation that reduces the given system of partial differential equations to a system of nonlinear ordinary differential equations (nlodes) which, in the case of conventional form, is reduced to a single nlode of second order. The first integral of the resulting nlode has been obtained via invariant-variational principle and Noether’s theorem and involves an integration constant. Depending upon the choice of the arbitrary constant two different forms of the exact solutions are indicated. The generalized forms of Weyl and Schwarzschild solutions for the case of no spin have also been deduced as particular cases. Investigation of nonconventional form of Einstein exterior equations has not only led to the recovery of solutions obtained through conventional form but it also yields physically important asymptotically flat solutions. In a particular case, a single third order nlode has been derived which evidently opens up the possibility of finding many further interesting solutions of the exterior field equations.     

Data in Voice — In-Band Short Messaging Service (SMS) für den analogen Flugfunk

6. Zusammenfassung  In diesem Artikel wurde die Data in Voice-Technologie vorgestellt. DiV ist eine Methode, die es erlaubt, kurze Daten-Messages gemeinsam mit der Sprache im analogen Flugfunkkanal zu übertragen. Man ist bei FREQUENTIS überzeugt, dass man mit dieser Methode viele Nachteile des vorhandenen analogen Flugfunks beseitigen und dadurch die Flugsicherheit wesentlich erh?hen k?nnte.     

Mathematical modeling of high-frequency electromagnetic heating of the bottom-hole area of horizontal oil wells

The results of theoretical investigations of the possibility of using intense high-frequency electromagnetic radiation in fields of high-viscosity oils with the aim of intensifying their production have been given. Expressions of the distribution of the electromagnetic field strength and the field of heat sources occurring in an oil bed under the action of high-frequency electromagnetic radiation transferred to the bed through a horizontal well have been obtained. A two-dimensional mathematical model of the process of production of oil through horizontal wells with simultaneous high-frequency electromagnetic action has been developed. The efficiency and profitableness of the method from the viewpoint of the energy balance have been evaluated.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 77, No. 6, pp. 105–111, November–December, 2004.     

POWER OPTIMIZATION OF FINITE STATE MACHINE BASED ON GENETIC ALGORITHM

Using state assignment to minimize power dissipation and area for finite state machines is computationally hard.Most of published results show that the reduction of switching activity often trades with area penalty.In this paper,a new approach is proposed.Experimental results show a significant reduction of switching activity without area penalty compared with previous publications.     

Irradiation of large area Mylar membrane and characterization of nuclear track filter

Ion irradiation of Si⁸⁺ ion beam of 100 MeV was scattered by a gold foil on a Mylar membrane of 25 Μm thickness in the form of film roll (width, 12.5 cm and length, 400 cm) at the Nuclear Science Centre, New Delhi. The characterization of etched nuclear tracks was carried out by gas permeation measurements. The samples cut from the film roll of required size for permeability measurements were etched in a controlled manner in a constant temperature bath of 6N NaOH solution. The opening of the conical etched tracks was characterized by hydrogen gas permeation.     

Surface electronic states in metal-porous silicon-silicon structures

The character of electronic states in porous silicon (PS)-Si, Pd-PS interfaces, and/or PS bulk at the formation of the metal-PS-silicon heterostructure was studied. The energy parameters were estimated using the deep-level transient spectroscopy and capacitance-voltage characteristics at the accounting of the voltage drop distribution along the structure. The analytical expression for voltage drop distribution along dielectric layer, porous layer and space charge region in silicon was obtained by solving the equation for continuity of the electrostatic induction vector. The electronic states studied were shown to manifest the quasi-continuous sub-band in the energy gap if the porous layer was 30-nm thick. Their density increased, as the energy position was being transformed to a deeper energy level of E_v+0.81 eV at the PS layer growing to 90 nm wide.