Abstract: System and methods for secured computer based assessment are described. In one embodiment, the method comprises receiving a question paper from an assessment conduction center, wherein the question paper contains dummy content having structure similar to an actual content of the question paper. A question paper metadata template containing metadata of the actual content that is generated based on the dummy content is created, and provided to the assessment conduction center for loading the actual content of the question paper in the question paper metadata template to generate an examination paper for distribution to one or more exam centers. A response of each of a plurality of aspirants corresponding to the examination paper is obtained from the one or more exam centers and said response is evaluated based on the metadata of the actual content, to generate a result for each of the plurality of aspirants.

Abstract: A method and apparatus for operating an optical rotating joint (2); comprising: providing redundancy for camera sensor signals to be passed through an optical rotating joint (2) by: (i) passing signals from a plurality of camera sensors (28, 30) via an optical changeover switching arrangement (70) to the optical rotating joint (2); and/or (ii) passing signals for a plurality of camera sensors (28, 30) toward the camera sensors (28, 30) from the optical rotating joint (2) via an optical changeover switching arrangement (70). The signals may be sensor control signals or sensor output signals to/from a plurality of sensors (26, 28, 30), for example camera sensors. The apparatus may further comprise one or more wavelength division multiplexers (68, 94) and/or wavelength division demultiplexers (66, 95).

Abstract: An optical rotating joint installation; comprising: a drive shaft for a rotating interface, the drive shaft comprising a hollow central bore; and an optical rotating joint located in the hollow central bore. The proportion of the cross-sectional area of the material retained in the annular section of the drive shaft is preferably greater than or equal to 50%, more preferably 60%, yet more preferably 75%. The diameter of the hollow central bore is preferably less than or equal to 20 mm, more preferably 16 mm. The optical rotating joint installation may be provided as a retro-fit to replace an existing solid drive shaft that does not have an optical rotating joint, for example by hollowing out the existing solid drive shaft or by replacing the existing solid drive shaft with a drive shaft with a hollow central bore.

Abstract: A method and apparatus for operating an optical rotating joint (2); comprising: routing optical signals through an optical rotating joint (2) by using a first optical circulator (64) on a first side of the optical rotating joint (2) to receive an optical signal and direct the optical signal onward to a first side of the optical rotating joint (2), and using a second optical circulator (93) on a second side of the optical rotating joint (2) to receive the optical signal from the second side of the optical rotating joint (2) and direct it onwards. The signals may be sensor control signals or sensor output signals to/from a plurality of sensors (26, 28, 30), for example camera sensors. The apparatus may further comprise one or more wavelength division multiplexers (68, 94) and/or wavelength division demultiplexers (66, 95).

Abstract: Methods and apparatus for finding a bias voltage (20) corresponding to a quadrature point of an optical modulator, the modulator comprising a biasable component which is configurable to be biased by application of the bias voltage (20) such that the modulator operates at quadrature, the method comprising: providing a target for the output power of the modulator which corresponds to quadrature; applying, to the biasable component, a bias voltage (20) having an initial value; thereafter, finding a value for the bias voltage (20) that biases the biasable component such that the output power of the modulator is within a pre-defined range of the target by, starting at the initial value, alternately increasing and decreasing (or decreasing and increasing) the bias voltage (20) with gradually increasing amplitude; and identifying the found value for the bias voltage (20) as a bias voltage corresponding to a quadrature point of the optical modulator.

Abstract: Methods and apparatus for controlling a bias voltage (20) supplied to an optical modulator that comprises a biasable component configurable to be biased by application of the bias voltage (20), the method comprising: providing a target for the modulator output power; applying, to the biasable component, a bias voltage (20) that biases the biasable component so that the output power is within a pre-defined range of the target; monitoring the output power and, if the output power of the modulator is determined to be outside the pre-defined range, varying the value of the bias voltage (20) to bring the output power back within the pre-defined range; and monitoring the optical input to the modulator and, if it has been disabled, maintaining the bias voltage (20) at its current level for a pre-determined length of time that is dependent upon how long the modulator has been operating at quadrature.

Abstract: Methods and apparatus for controlling a bias voltage supplied to an optical modulator, the modulator comprising a biasable component, the biasable component being configurable to be biased by application of the bias voltage (20) such that the modulator operates at quadrature, the method comprising: providing a target for the output power of the modulator, the target for the output power of the modulator being an output power corresponding to the modulator operating at quadrature; applying, to the biasable component, a bias voltage (20) having an initial value of 0V; and, thereafter, varying the bias voltage (20) until the value of the bias voltage (20) is the value that is closest to the initial value and that biases the biasable component so that the output power of the modulator is within a pre-defined range of the target output power.

Abstract: System and methods for secured computer based assessment are described. In one embodiment, the method comprises receiving a question paper from an assessment conduction center, wherein the question paper contains dummy content having structure similar to an actual content of the question paper. A question paper metadata template containing metadata of the actual content that is generated based on the dummy content is created, and provided to the assessment conduction center for loading the actual content of the question paper in the question paper metadata template to generate an examination paper for distribution to one or more exam centers. A response of each of a plurality of aspirants corresponding to the examination paper is obtained from the one or more exam centers and said response is evaluated based on the metadata of the actual content, to generate a result for each of the plurality of aspirants.

Abstract: A process for preparing a toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester resin having an acid value (AV) greater than 5 mg KOH/g, the process comprising: providing an aqueous dispersion of self-dispersed polyester resin particles and associating the polyester resin particles by means of a change in the pH of the dispersion.

Abstract: A process for preparing a toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester resin having an acid value greater than 5 mg KOH/g, the process comprising: providing an aqueous dispersion of polyester resin particles stabilized by an ionic surfactant and then associating the polyester resin particles.

Abstract: A bias controller and a method for controlling the bias of an electro-optic modulator are provided. In the method, for a received indication of modulator temperature, steps are provided for accessing a look-up table to determine a corresponding value of bias voltage, for a required bias point, to apply to the modulator. If no such value is stored, additional steps are provided to generate a pilot tone for input to the modulator and to recognize, from the signal content of a modulated optical signal output by the modulator, operation of the modulator at the required bias point, adjusting the value of bias voltage being applied to the modulator as required. When operation at the required bias point is recognized, the respective value of bias voltage for that modulator temperature is stored in the look-up table. The same method is provided to configure a bias controller in respect of a given modulator, if necessary ab initio.

Abstract: A bias controller for an optical modulator. The modulator includes a bias electrode that is operable when appropriately biased by an applied bias voltage to configure the modulator to operate at quadrature, and the bias controller includes: a generating arrangement for generating power signals indicative of the optical output power of the modulator; and a processor operably connected to the generating arrangement and said bias electrode and arranged to receive said power signals from said generating arrangement and to control the bias voltage applied to said bias electrode.

Abstract: A base station is provided for communicating data to a mobile terminal unit by means of at least one antenna unit, wherein the at least one antenna unit is linked to the base station by means of at least one optical fiber and the at least one antenna unit is operable to communicate wirelessly with the mobile terminal unit. The base station comprises an optical transmitter for transmitting modulated data signals to the at least one antenna unit for wireless transmission, an optical receiver for receiving modulated data signals forwarded by the at least one antenna unit and a demodulator for demodulating received modulated data signals.

Abstract: An optical routing network provides function-specific routing, in the optical domain, of radio frequency (RF) signals between inputs to the network and function-specific outputs from the network. RF signals input to the network may comprise signals received by elements of a multi-function array antenna for routing to function-specific receiving equipment or signals from function-specific transmitting equipment for routing to selected elements of the antenna for transmission. The optical routing path through the optical routing network is chosen by selecting one or more predetermined optical carrier wavelengths in the optical routing network, each carrier wavelength being associated with a particular function of the antenna.

Abstract: The invention provides a process for the manufacture of a toner which comprises the steps of: a) providing a latex dispersion containing primary resin particles and surfactant; b) providing a colorant dispersion containing primary colorant particles and surfactant; c) optionally providing a wax dispersion containing primary wax particles and surfactant; d) providing at least one carboxy functional compound of Formula (1), which may be in acid, salt and/or complex form: wherein R is a carbocyclic or heterocyclic radical which may be optionally substituted and Z1 is a bond or linker group and wherein the amount of carboxy functional compound of Formula (1) provided is greater than 3% by weight, the amount of carboxy functional compound being calculated according to the following equation: amount ? ? of ? ? carboxy ? ? functional ? ? ? compound ? ? ( % ? ? weight ) = 100 × weight ? ? ? of ? ? carboxy ? ? functional ? ? compound ( weight

Abstract: The invention provides a process for the manufacture of a toner which comprises the steps of: a) providing a latex dispersion containing primary resin particles and surfactant; b) providing a colorant dispersion containing primary colorant particles and surfactant; c) optionally providing a wax dispersion containing primary wax particles and surfactant; d) providing at least one carboxy functional compound of Formula (1), which may be in acid, salt and/or complex form: wherein R is a carbocyclic or heterocyclic radical which may be optionally substituted and Z1 is a bond or linker group, on condition that the amount of carboxy functional compound of Formula (1) provided in acid and/or salt form is at least 1.

Abstract: A bias controller and a method for controlling the bias of an electro-optic modulator are provided. In the method, for a received indication of modulator temperature, steps are provided for accessing a look-up table to determine a corresponding value of bias voltage, for a required bias point, to apply to the modulator. If no such value is stored, additional steps are provided to generate a pilot tone for input to the modulator and to recognize, from the signal content of a modulated optical signal output by the modulator, operation of the modulator at the required bias point, adjusting the value of bias voltage being applied to the modulator as required. When operation at the required bias point is recognized, the respective value of bias voltage for that modulator temperature is stored in the look-up table. The same method is provided to configure a bias controller in respect of a given modulator, if necessary ab initio.

Abstract: A process for the manufacture of a toner comprising toner particles which comprise at least resin and colorant, the process comprising the steps of: providing a mixed dispersion of at least primary resin particles, primary colorant particles and a carboxy functional compound of Formula (1) and/or a salt thereof and/or a complex thereof in a liquid medium, wherein R is a carbocyclic or heterocyclic group and Z1 is a bond or a linker group, the at least primary resin particles and primary colorant particles being stabilised by two or more surfactants in the liquid medium, the surfactants comprising at least a first ionic surfactant and a second ionic surfactant of the same polarity as the first ionic surfactant, wherein the first and second ionic surfactants have different linear chain lengths; and causing the primary particles to associate.

Abstract: A process for preparing a toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester resin having an acid value (AV) greater than 5 mg KOH/g, the process comprising: providing an aqueous dispersion of self-dispersed polyester resin particles and associating the polyester resin particles by means of a change in the pH of the dispersion.

Abstract: A process for preparing a toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester resin having an acid value greater than 5 mg KOH/g, the process comprising: providing an aqueous dispersion of polyester resin particles stabilised by an ionic surfactant and then associating the polyester resin particles.