Abstract: A method and system of placing cells of an IC design using partition preconditioning. In one embodiment, cells of an integrated circuit design are grouped to model curvature of an objective function. The grouping produce a plurality of cell clusters. The model formed may be a binary tree. The curvature of the objective function for each of the cell clusters is estimated. Interactions between said cell clusters are described as a relation. A set of preconditioning values which achieves a separation of variables of the relation is determined. The preconditioning may be applied to a conjugate gradient placement process to advantageously decrease the number of iterations required to produce an optimized placement of the cells.

Abstract: A reactor chamber forms part of an exhaust system of an internal combustion engine. Within the chamber are electrodes between which there is disposed a bed of active material through which, in use, the exhaust gases pass. In the presence of an electrical discharge, driven by an electrical voltage applied across the electrodes, the active material has a catalytic action in the reduction of nitrogenous oxides in the exhaust and also acts to remove hydrocarbons from the exhaust gases.

Abstract: A reactor (1) comprises a pair of electrodes (4, 13) spaced apart to provide a path therebetween for gas flow. A permeable mass of silicon carbide 816) is provided in the space between the electrodes (4, 13) for trapping carbonaceous material in the gas flowing through the space. The silicon carbide (16) is arranged to have an electrical resistivity which is sufficiently high to permit formation, when an appropriate electrical potential is applied across the electrodes (4, 13), of a plasma in the gas within the interstices of the silicon carbide through which the gas permeates.

Abstract: An embodiment includes an optical source, an optical receiver, and an interconnecting optical fiber. A data sequence is received and encoded or formatted as an IP packet using an encoding format capable of returning a signal representing the IP packet to a predetermined value at the beginning of each bit period of the IP packet at a physical layer of the network. The encoded IP packet is then transmitted directly over an optical layer of the network without adapting the IP packet to another encoding format or using an adaptation layer in the network (e.g., at a data link layer or higher). The optical receiver receives the IP packet and then a clock signal is extracted without the overhead and costs associated with additional adaptation or encoding of the IP packet.

Abstract: An integrated OTDR/OSC mechanism for monitoring an optical transport system without disrupting the normal service. The invention combines two essential network components in an integrated mechanism. These components are the mandatory OSC function as part of any DWDM network, and the in-skin, in-service attributes of the OTDR engine. One pair of control wavelengths is sufficient to perform both OSC and OTDR functionalities. In this way, a distributed control function, OTDR procedures, and fiber monitoring is achieved, while trace acquisition from anywhere in the network becomes possible.

Abstract: An industrially realistic process for upgrading of titaniferous materials is disclosed. The process comprises the following steps: (i) a pretreatment which has the effect of rendering silica amenable to leaching under the particular conditions of a subsequent leach, and (ii) an aqueous leach in the presence of an acid, the conditions of which are chosen such that silica which enters solution is not hydrolysed or precipitated as a silicate. The pretreatment step (i) may comprise alkaline leaching, roasting or smelting. The leaching step (ii) may be conducted at low solids densities.

Abstract: A process for upgrading of titaniferous material containing silica, including pretreating the titaniferous material by alkaline leaching to precipitate the silica as an aluminosilicate which is amenable to further leaching. Subsequently, the pretreated titaniferous material is leached under acid conditions, causing the silica to enter solution under conditions such that the silica is not hydrolysed or precipitated as a silicate.

Abstract: The application discloses a process for upgrading a titaniferous material by removal of impurities contained in the material especially radionuclides. The process involves heating the titaniferous material to a temperature of less than 1300° C. to form a solid titaniferous phase and a liquid oxide or glassy phase in the presence of a material that promotes the formations of such phases, cooling the product at a rate that maintains the glassy phase in an amorphous state and leaching the solidified material with an acid or an alkali to remove the impurities. Materials that promote the formation of the desired phases include compounds of alkali metals and boron. Examples include borax, caustic soda, soda ash and silica.

Abstract: An embodiment includes a polarization beam splitter and a feedback unit, preferably having an autocorrelator, a processing unit and a polarization controller. Polarized splitter separates the lower-speed tributary signals out of the higher-speed optical signal based upon a polarization relationship (e.g., orthogonal) between the tributary signals. The feedback unit, typically an autocorrelator and a polarization adjustment device, adjusts the higher-speed signal's state of polarization based upon an autocorrelation value of one of the lower-speed tributary signals. The autocorrelation value of one of the lower-speed tributary signals is provided to the polarization adjustment device, which typically includes a processing unit and a polarization controller. The polarization adjustment device adjusts the higher-speed signal's polarization state based upon the autocorrelation extinction ratio value.

Abstract: The application discloses a process for upgrading a titaniferous material by removal of impurities contained in the material especially radionuclides. The process involves heating the titaniferous material to a temperature of less than 1300° C. to form a solid titaniferous phase and a liquid oxide or glassy phase in the presence of a material that promotes the formations of such phases, cooling the product at a rate that maintains the glassy phase in an amorphous state and leaching the solidified material with an acid or an alkali to remove the impurities. Materials that promote the formation of the desired phases include compounds of alkali metals and boron. Examples include borax, caustic soda, soda ash and silica.

Abstract: Associated with an optical transport system, a packet oriented supervisory network provides differentiated classes of service (CoS) for a plurality of WDM layer applications on diverse nodes such that as soon as a higher priority application or packet arrives, the lower priority application is affected in favor of the higher one. One or more optical control channels (OSC) are used as the physical medium for implementing the packet oriented supervisory network of the invention. This new functionality of the optical control channel (OSC) enables multiple services by allowing each application to use up to 100% of the OSC bandwidth, if no other application is using it.

Abstract: A multiplexer demultiplexer for conversion of optical data between a serial bit stream having a bit rate in excess of that of conventional photodetection devices and multiple bit streams at a bit rate that may be serviced using conventional photodetection devices. A wavelength conversion element uses four-wave mixing to produce from a single high rate data stream multiple intermodulation products that together represent the input serial data stream in wavelength division multiplexed (WDM) form. A related device multiplexes multiple WDM data streams provided at conventional bit rates to a serial bit stream having a bit rate in excess of that of conventional photodetection devices.

Abstract: An iterative process is used to set the phase prechirp of a WDM optical transport system to a system's optimal level that maximizes the signal quality. A signal degradation factor takes into account linear and non-linear effects along the optical path and is used as a receive end feedback signal to control the phase prechirp level at the transmitter site. By using the FEC corrected errors rate as the feedback signal, optimization of signal quality is performed even when the system is running error free. By using an adaptive phase prechirp transmitter, signal degradation compensation can be also performed on a per wavelength basis to compensate for the residual dispersion slope and to allow optimization of individual channels independently of the net link dispersion value.

Abstract: An embodiment includes an optical source, an optical receiver, and an interconnecting optical fiber. A data sequence is received and encoded or formatted as an IP packet using an encoding format capable of returning a signal representing the IP packet to a predetermined value at the beginning of each bit period of the IP packet at a physical layer of the network. The encoded IP packet is then transmitted directly over an optical layer of the network without adapting the IP packet to another encoding format or using an adaptation layer in the network (e.g., at a data link layer or higher). The optical receiver receives the IP packet and then a clock signal is extracted without the overhead and costs associated with additional adaptation or encoding of the IP packet.

Abstract: An embodiment includes a gating device, a feedback device and a control device. Soliton pulses are received by the gating device, which detects and monitors a dispersive-wave between adjacent soliton pulses using a timing circuit. The timing circuit typically provides a gating signal offset in phase from the soliton pulses in order to trigger the gating device. Triggering the gating device allows the dispersive-wave to be accessed and monitored between adjacent soliton pulses. The feedback device, typically using detectors and processing circuitry, measures the energy of the soliton pulses and the energy of dispersive wave. The feedback determines a ratio of the energy levels as an indication of soliton-pulse transmission performance. The indication is provided to the control device as a feedback signal so that the control device can appropriately adjust characteristics of the soliton pulses and improve or optimize transmission performance.

Abstract: In a WDM transmission system carrying amplitude modulated traffic in which significant cross-phase modulation occurs, each of the individual channels is pre-chirped at the transmitter with replicas, or low-pass filtered replicas of the amplitude modulation applied to each of the other channels. Prechirping of each individual channel with a replica of the amplitude modulation applied to that channel may be added in order additionally to provide compensation for self-phase modulation.

Abstract: A method of determining an indicator for the presence of an image is disclosed in which the image is comprised of a two dimensional array of pixels. The method finds particular use in the prevention of fraudulent copying of images, such as bank notes using colour laser copiers and printers. The method firstly imposes a grid of cells over a portion of the image. Then a representative value for each of the cells is determined. Next, a measure of the difference between the representative values of adjacent cells of the grid is determined over the whole of the grid. The first three steps are then repeated for substantially all possible positions of the grid of cells to determine a grid position having an overall maximum positional difference. Finally, the grid position and the representative value for each of said cells is used as a representation of the image. The representation can thus comprise a template used in an image detection system.

Abstract: An image detection system is disclosed for the detection of an image in an input pixel stream. An image is input as a input pixel stream and accumulated and converted into cells which are formed into cell data portions from regions of a corresponding image of the input pixel stream. A template storage ROM stores at least one template that comprises a multiplicity of cell data entries derived form an desired image to be detected. A comparator matrix is connected to the cell converter and the template ROM for comparing the cell data portions with a multiplicity of cell data entries to derive a template detection signal when a predetermined number of the cell data portions match with the multiplicity of said cell data entries. The system finds particular use in the prevention of fraudulent copying of images, such as bank notes using colour laser copiers and printers.

Abstract: An optical interferometer incorporating a signal strength modulated optical phase delay, such as a Kerr effect element in one of its arms is employed to improve the cross-talk isolation/extinction ratio of an optical switch, amplitude modulator, or amplitude modulated optical transmitter. The Kerr element is constructed so that its intensity dependent optical path length is such as to provide destructive interference at the interferometer output when the light input to the interferometer is low, and constructive interference when the input is high. The place of the Kerr effect element can alternatively be taken by an electro-optic modulator driven with an electrical version of the data modulation appearing on the optical signal.

Abstract: The present invention provides a method and apparatus for error diffusing a series of images, each of said images being made up of component pixels. The method comprises, for each of said pixels determining a current error diffused value for said pixel; adding an error margin to each current error diffused value to produce a marginalised error diffused value, said marginalised error diffused value being a translation of said current error diffused value in a direction towards that of a previous output value for said pixel; utilising said marginalised error diffused value to determine a closest possible output value to said marginalised error diffused value; and error diffusing the difference between said closest possible output value and said error diffused value to adjacent pixels.