Abstract: One embodiment of the invention provides a method and apparatus for performing service adaptation in respect of a mobile computing device. The method includes providing a service adaptation specification as a set of rules, where each rule comprises a rule body containing one or more premises and a rule head containing one or more conclusions that hold if said one or more premises are true. The rules are defined as classes in an ontology. The premises represent adaptation context and the conclusions represent service adaptation decisions. The method further comprises running the rules on a Description Logics reasoner in conjunction with adaptation context relating to the mobile computing device for a requested service to produce one or more service adaptation decisions. The method further comprises adapting the requested service provided to the mobile computing device in accordance with the service adaptation decisions from the description logics reasoner.

Abstract: One embodiment of the invention provides a method and apparatus for use by a device in a pervasive computing environment. The method includes receiving at the device multiple XML sources describing devices and/or services currently available to said device within the pervasive computing environment. The device then transforms the received multiple XML sources into a single ontology. In one embodiment, the multiple XML sources are first transformed into two or more ontologies, which are then merged into a final single ontology for use by the device.

Abstract: A device for dielectrophoretic manipulation of suspended particulate matter comprises an analysis electrode and a separate cover electrode wherein the analysis electrode comprises an electrically conductive layer of material provided on a substrate support and apertures are defined through the electrically conductive layer. The device can be used for detection, analysis, fractionation, concentration or separation of particulate matter.

Abstract: A method of producing a thin film comprising uniformly dispersed carbon nanotubes, the method comprising the steps of: adapting a molecular semiconductor to make it soluble; adapting the molecular semiconductor to facilitate the formation of a high degree of molecular order and frontier orbital overlap between adjacent molecules; adapting carbon nanotubes to make them soluble; combining the soluble carbon nanotubes and the soluble molecular semiconductor in a solvent to form a solution; producing the thin film from the solution.

Abstract: A system for transmitting input data over a speech channel of a network comprising: a modulator arranged to produce a modulated waveform signal transforming the data for transmission over the network; a channel compensation filter arranged to filter the modulated waveform signal after it has been transmitted over the speech channel to compensate for the response of the speech channel; and a demodulator arranged to retrieve the data from the filtered waveform signal.

Abstract: An electronic or optoelectronic device fabricated from a crystalline material in which a parameter of a bandgap characteristic of said crystalline material has been modified locally by introducing distortions on an atomic scale in the lattice structure of said crystalline material and the electronic and/or optoelectronic parameters of said device are dependent on the modification of said bandgap is exemplified by a radiation emissive optoelectronic semiconductor device which comprises a junction (10) formed from a p-type layer (11) and an n-type layer (12), both formed from indirect bandgap semiconductor material. The p-type layer (11) contains a array of dislocation loops which create a strain field to confine spatially and promote radiative recombination of the charge carriers.

Abstract: An electronic or optoelectronic device fabricated from a crystalline material in which a parameter of a bandgap characteristic of said crystalline material has been modified locally by introducing distortions on an atomic scale in the lattice structure of said crystalline material and the electronic and/or optoelectronic parameters of said device are dependent on the modification of said bandgap is exemplified by a radiation emissive optoelectronic semiconductor device which comprises a junction (10) formed from a p-type layer (11) and an n-type layer (12), both formed from indirect bandgap semiconductor material. The p-type layer (11) contains an array of dislocation loops which create a strain field to confine spatially and promote radiative recombination of the charge carriers.

Abstract: A mobile station positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.

Abstract: An optical coupler comprises an input waveguide, an intermediate waveguide, an output waveguide, a first grating situated between the input and intermediate waveguides, and a second grating situated between the intermediate and output waveguides such that, in use, light propagating in the input waveguide is coupled into the intermediate waveguide with the assistance of the first grating, and thence is coupled into the output waveguide with the assistance of the second grating. The coupler is a directional coupler, in particular a dual grating-assisted directional coupler, and may be used to couple light between an optical fibre and an integrated semiconductor device, or between dissimilar waveguides.

Abstract: A multifilar helix antenna includes helical antenna filaments, each filament having a square waveform pattern along its length, resulting in reduced axial length. A multifilar helix antenna according to the invention includes helical antenna filaments, each filament incorporating a microstrip spur-line band stop filter enabling multi-band operation.

Abstract: A method of and apparatus for determining the spatial distribution of polarisation properties of an optical fiber (1). Pulses (7) of light are transmitted along the optical fiber (1) and the polarisation state of light backscattered from portions e and elements R of the optical fiber (1) detected. A spatial distribution of linear retardance ?, orientation of linear retardance axes q and circular retardance axes can be accurately determined. This has application in the analysis of Polarisation Mode Dispension (PMD) in telecommunications as well as, inter alia, strain, stress, temperature and electric current and voltage measurement using optical fibers.

Abstract: A device for dielectrophoretic manipulation of suspended particulate matter comprises a plurality of interleaved layers of electrically conductive and non-conductive material wherein at least one channel is defined through a plurality of the interleaved layers of electrically conductive material.

Abstract: A thermionic cathode (100) comprises an individual carbon nanotube (102) attached between two electrodes (104, 106). The electrodes (104, 106) each comprise a post (110, 112) and a carbon fibre (114, 116). A gap (118) narrower than the length of the nanotube (102) is provided between the two carbon fibres and the carbon nanotube (102) bridges the gap. This provides an extremely efficient thermionic cathode (100).

Abstract: An optical coupler comprises an input waveguide, an intermediate waveguide, an output waveguide, a first grating situated between the input and intermediate waveguides, and a second grating situated between the intermediate and output waveguides such that, in use, light propagating in the input waveguide is coupled into the intermediate waveguide with the assistance of the first grating, and thence is coupled into the output waveguide with the assistance of the second grating. The coupler is a directional coupler, in particular a dual grating-assisted directional coupler, and may be used to couple light between an optical fibre and an integrated semiconductor device, or between dissimilar waveguides.

Abstract: A multifilar antenna (200) comprises n spaced antenna filaments, where n is on integer greater than 1; a matching circuit (210) for matching the characteristic impedance of the antenna to that of a transmitting and/or receiving apparatus; a weighting circuit (240) for applying respective gain and phase adjustments to signals passed to or from the n filaments; switch means (310) associated with each filament for selectively altering the electrical length and/or interconnections of the filaments; means for detecting electrical properties of the multifilar antenna with respect to the frequency, polarisation and/or direction of propagation of a signal to be received or transmitted by the multifilar antenna and/or impedance matching of the antenna; and control means (230), responsive to the detective means, for controlling the operation of the matching circuit (210), the weighting circuit (240) and the switch means (310) to adjust the properties of the multifilar antenna (200) to suit better a current signal to be

Abstract: In a collimator assembly for an X-ray imaging system comprising adjustable X-ray attenuating collimator vanes that define the area of a patient to be exposed to an X-ray beam, the collimator vanes (1, 2, 3, 4) are automatically driven under the control of an image processing apparatus to attenuate the X-ray beam to form exposure fields (5) of chosen shape.

Abstract: A method for estimating cell coverage in a mobile telecommunications network. The method includes the steps of receiving signal quality and position information from the users of the network and using the information to calculate a coverage map. Update information is also received to update the coverage map. The estimated cell coverage can be used in radio resource allocation methods.

Abstract: A wireless communication system includes a distributed antenna arrangement having a plurality of antenna elements arranged in groups and at least one mobile station including a RAKE reciever for combining received signals produced by the antenna elements. The antenna elements producing the strongest antenna signals are assigned to different groups and the antenna signal produced by the different groups of antenna elements are subjected to preset relative delays enabling the antenna signals to be coherently combined.

Abstract: A multifilar helix antenna comprises a plurality of helical antenna filaments each having a square waveform pattern along its length, giving reduced axial length. Also described is a multifilar helix antenna comprising a plurality of helical antenna filaments each incorporating a microstrip spur-line band stop filter for enabling multi-band operation.

Abstract: A multifilar antenna comprises n spaced antenna filaments, where n is an integer greater than 1; a matching circuit for matching the characteristic impedance of the antenna to that of a transmitting and/or receiving apparatus; a weighting circuit for applying gain and phase adjustments to signals passed to or from the n filaments; switch means associated with at least some of the filaments for selectively altering the electrical length and/or interconnections for the filaments; means for detecting electrical properties of the multifilar antenna with respect to the frequency, polarization and/or direction of propagation of a signal to be received or transmitted by the multifilar antenna and/or impedance matching of the antenna; and control means, responsive to the detecting means, for controlling the operation of the matching circuit, the weighting circuit and the switch means to adjust the properties of the multifilar antenna to suit better a current signal to be received or transmitted.