An apparatus for shaping an edge of an aerofoil, the apparatus having first and second brushes and each brush having a plurality of bristles. A first motor rotates the first brush about a first axis and a second motor rotates the second brush about a second axis. The axes are arranged substantially parallel to the bristles of the respective brush. A support structure holds the first brush such that the first axis intersects a first surface of the edge of the aerofoil and holds the second brush such that the second axis intersects a second surface of the edge of the aerofoil. There are means to produce relative movement the first and second brushes and the aerofoil such that the first and second brushes move longitudinally along the edge of the aerofoil to shape the edge of the aerofoil.

Methods and apparatus for making and using tools, for example concrete cutting blades. The tool includes a first layer and second layer that are oppositely disposed. The first and second layers include working surfaces that support at least one working element when the working element is applied to a work piece. Additionally, an intermediate structure is included between the first and second layers. The intermediate structure can include a plurality of components extending in the area between the structural surfaces and the working surfaces.

A carboxylate detergent prepared by the process comprising (a) alkylating a hydroxyaromatic compound with at least one normal alpha olefin having from about 12 to about 30 carbon atoms per molecule that has been isomerized to obtain an isomerized alpha olefin having 15-98 wt % branching and a residual alpha olefin content of between from about 0.1 to about 30 wt %, thereby producing an alkylated hydroxyaromatic compound; (b) neutralizing the resulting alkylated hydroxyaromatic compound with an alkali metal base; (c) carbonating the alkali metal salt from step (b) with carbon dioxide; (d) acidifying the salt produced in step (c); and (e) overbasing the resulting alkylated hydroxyaromatic carboxylic acid.

The present invention provides transgenic soybean event MON87769, and cells, seeds, and plants comprising DNA diagnostic for the soybean event. The invention also provides compositions comprising nucleotide sequences that are diagnostic for said soybean event in a sample, methods for detecting the presence of said soybean event nucleotide sequences in a sample, probes and primers for use in detecting nucleotide sequences that are diagnostic for the presence of said soybean event in a sample, growing the seeds of such soybean event into soybean plants, and breeding to produce soybean plants comprising DNA diagnostic for the soybean event.

Provided is a magnetic disk comprising a lubricating layer formed of a lubricant. The lubricant constituting the lubricating layer has excellent properties, for example, excellent fluidity, surface energy, and CFT properties. By virtue of the excellent properties, the magnetic disk has a high level of reliability despite a low flying height of a magnetic head due to a recent rapid increase in recording density and a very severe environment resistance requirement due to diversification of applications. The magnetic disk comprises a substrate and at least a magnetic layer, a protective layer, and a lubricating layer provided in that order over the substrate. The lubricating layer is formed of a lubricant that is a mixture of a specific perfluoropolyether lubricant with a lubricant formed of a compound comprising perfluoropolyether groups having a perfluoropolyether main chain in the structure thereof and having a hydroxyl group at the end thereof, the perfluoropolyether groups being bonded to each other through a divalent linking group having at least two hydroxyl groups in the structure thereof.

The present invention provide a two-component anti-seizure agent for hot metal working process comprising the first aqueous solution and the second aqueous solution, wherein the first aqueous solution contains 10˜30 mass % of sodium silicate equivalent to anhydride to 100 mass % of total mass of the first aqueous solution, and the second aqueous solution contains at least one kind selected from a group consisting of: an organic acid and water-soluble amine salts thereof, an inorganic acid and water-soluble amine salts thereof, a water-soluble amine, a water-soluble alcohol, and a water-soluble metal chloride. When the two-component anti-seizure agent is applied onto disk-roll type guide shoes, it can be provided and maintained on the circumferential surface of the disk-roll type guide shoes without washed away by rolls' cooling water. Thereby, the anti-seizure agent does not adhere to rolls and the rolls and a pipe material do not cause slippage each other. Thus, it is capable to carry out piercing-rolling of the pipe material.

The engine oil additive contains multiple 300 to 500 nm-long polygonal plate-shaped silver crystal particles. The engine oil contains a base oil and the engine oil additive. The method of adding the additive to an engine oil includes adding multiple 300 to 500-nm-long polygonal plate-shaped silver crystal particles as an additive to the engine oil.

Para-alkylated substituted diphenylamines are made by catalytically alkylating diphenylamine with a branched-chain alkene, such as propene, oligomer mixture in which the oligomer present in the greatest percentage has 15-24 carbon atoms. The alkylated diphenylamines are useful crankcase lubricant additives such as for reducing piston deposits and engine sludge.

The lubricating oil composition of the invention comprises a lubricating base oil with a kinematic viscosity at 100° C. of 1-20 mm2/s, and a viscosity index improver having a ratio M1/M2 of 0.20 or greater, between the total area of the peaks between chemical shifts of 36-38 ppm M1 and the total area of the peaks between chemical shifts of 64-66 ppm M2, with respect to the total area of all of the peaks, in the spectrum obtained by 13C-NMR. The lubricating oil composition of the invention has excellent effects, with a sufficiently high HTHS viscosity at 150° C., and a sufficiently low kinematic viscosity at 40° C., a sufficiently low kinematic viscosity at 100° C. and a sufficiently low HTHS viscosity at 100° C.

Polymeric compositions and methods for making and using the same are provided. The polymeric composition can include a first ethylene-based copolymer and a second ethylene-based copolymer. The first ethylene-based copolymer can have a weight percent of ethylene-derived units based on a weight of the polymeric composition (EA) ranging from about 35 wt % to about 52 wt % and a weight-average molecular weight (MwA) of less than or equal to 130,000. The second ethylene-based copolymer can have a weight percent of ethylene-derived units based on the weight of the polymeric composition (EB) ranging from about 65 wt % to about 85 wt % and a weight-average molecular weight (MwB) of less than 130,000.

Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.

Disclosed herein are silicone wax emulsions and methods of manufacturing the same. One method of manufacturing silicone wax emulsions as disclosed herein comprises charging alpha-olefins of C-18 or greater chain length to a heating and mixing vessel along with undecylenic acid and blocking the carboxylic acid of the undecylenic acid with a compound containing a trimethylsilyl group by adding the compound in sufficient quantity and heating as a melt until blocking is complete. While maintaining a melt temperature, a silicone polymer containing methyl hydrogen siloxy units is added, followed by a hydrosilation reaction catalyst to effect a hydrosilation reaction. This results in an acid functional silicone polymer. The acid functional silicone polymer is combined with an emulsifier, and the molten combination is added to a stirred solution of alkaline agent and water that has been heated to a temperature above the silicone wax melting point. This process produces silicone wax emulsions with excellent qualities.

The invention provides a lubricating composition containing (a) 0.001 wt % to 15 wt % of a polymer with radial or star architecture; (b) an overbased detergent; (c) a dispersant; and (d) an oil of lubricating viscosity. The invention further provides a method for lubricating a mechanical device with the lubricating composition.

Disclosed are rheology modifiers comprising compositionally disperse polymeric compositions and/or crystallinity disperse polymeric compositions that may be useful in modifying the rheological properties of lubrication fluids, and methods for making such compositions. The compositionally disperse polymeric composition are formed from at least two discrete compositions of ethylene copolymers. The crystallinity disperse polymeric composition are formed from ethylene copolymers having at least two discrete values of residual crystallinity.

A novel molybdenum dithiocarbamate composition is produced by preparing a di-tridecylamine (DTDA) intermediate from a butylene feedstock comprising greater than 50% 2-butylene, and preparing a molybdenum dithiocarbamate composition from the DTDA intermediate. The resulting molybdenum dithiocarbamate composition are according to formula (1), wherein R1 to R4 are C11-C14 isoalkyl groups, and X represents oxygen and/or sulfur atoms, and R1 to R4 comprise, on average, greater than 98% C13:

Provided is a method for preparing a grease composition, which comprises mixing an amine in a lubricating bas oil and an isocyanate in a lubricating base oil under high pressure and high flow rate impingement. In one embodiment, the mixing and reaction occurs in a reaction injection molding device. The resulting grease composition is an extremely low noise grease, being virtually clear of any urea thickener particles.

A method for screening a lubricating oil composition having at least one base oil of lubricating viscosity and at least one lubricating oil additive is provided, the method comprising the steps of (a) inputting into a computational device an amount of each of the at least one lubricating oil additive, based on the total weight of the lubricating oil composition and, optionally, a value of at least one property associated with each of the at least one base oil of lubricating viscosity; (b) computing a prediction of at least one lubricating oil composition property-determining test result for the lubricating oil composition; (c) computing a cost for the lubricating oil composition; and (d) outputting the results. Also provided are systems and computer program devices for screening lubricating oil compositions.

The present invention is directed to a method for improving one or more of the control of deposit formation and friction in an engine lubricated using a lubricating oil comprising a base oil and additives by employing as the additive the necessary combination of a borated hydroxyl saturated hydrocarbyl ester amide-amine mixture, zinc dialkyl dithiophosphate, and metal salicylate detergent, the deposit formation and friction being improved as compared to a lubricating oil containing the borated hydroxyl saturated hydrocarbyl ester amide-amine mixture, zinc dialkyl dithiophosphate and a detergent other than metal salicylate, such as metal phosphate and/or metal sulfonate.

Lubrication additives of the current invention require formation of emulsions in base lubricants, created with an aqueous salt solution plus a single-phase compound such that partitioning within the resulting emulsion provides thermodynamically targeted compounds for boundary layer organization thus establishing anti-friction and/or anti-wear. The single-phase compound is termed “boundary layer organizer”, abbreviated BLO. These emulsion-contained compounds energetically favor association with tribologic surfaces in accord with the Second Law of Thermodynamics, and will organize boundary layers on those surfaces in ways specific to the chemistry of the salt and BLO additives. In this way friction modifications may be provided by BLOs targeted to boundary layers via emulsions within lubricating fluids, wherein those lubricating fluids may be water-based or oil-based.

[Task] In a sliding member comprising a substrate and a coating layer provided thereon, the coating layer has a sliding surface and is formed of a resin-based coating and particles of a solid lubricant dispersed therein. The orientation ratio of (001) plane of the solid lubricant is enhanced.[Means for Solution]The coating layer of a sliding layer has an average thickness of 3 μm or less. The particles of the solid lubricant have 2 μm or more of an average particle diameter as measured by the laser diffraction method. The solid lubricant dispersed has 90% or more of relative C-axis intensity ratio.

An oil-soluble lubricating oil additive composition comprising (a) at least 3.5 wt-% of at least one friction modifier selected from the group consisting of fatty acids, fatty acid amides, fatty acid esters, and alkane diols which have a melting point of greater than 30° C.; (b) at least 10 wt-% actives dispersant; and (c) a sufficient amount of surfactant to make said additive composition haze-, sediment-, and skin-free, provided that said additive composition contains at least 150 mm surfactant per kg of said lubricating oil additive composition.

A water-soluble metalworking oil agent is provided by blending the following components A, B, C and D: (A) at least one of a condensed fatty acid obtained by dehydration-condensing a ricinoleic acid, and a condensed fatty acid obtained by dehydration-condensing a monovalent carboxylic acid with an alcoholic hydroxyl group of a condensed fatty acid obtained by dehydration-condensing a ricinoleic acid;(B) an ester compound provided by a dehydration condensate of a monovalent or multivalent alcohol and a monovalent carboxylic acid;(C) an amine compound; and(D) water. A blend ratio of the component A is 10 mass % or more of a total amount of the oil agent and a blend ratio of the component B is 5 mass % or more of the total amount of the oil agent.

The present invention relates to a method of driveline device by supplying to the driveline device a lubricating composition containing an oil of lubricating viscosity and an antiwear package, wherein the antiwear package includes: (a) derivatives of a carboxylic acid (typically a hydroxycarboxylic acid); and (b) a phosphorus compound. The invention further provides lubricating compositions containing an oil of lubricating viscosity and an antiwear package, wherein the antiwear package includes (a) derivatives of a carboxylic acid (typically a hydroxycarboxylic acid); and (b) an amine or metal salt of a phosphorus compound that is either (i) a hydroxy-substituted di-ester of (thio)phosphoric acid, or (ii) a phosphorylated hydroxy-substituted di- or tri-ester of (thio)phosphoric acid.

Provided are a lubricant composition capable of reducing friction between sliding parts at least one of which contains an aluminum-based material in a lubrication section, and a method for lubricating an aluminum-based member with the composition. The lubricant composition is for use in a lubrication section having sliding parts at least one of which contains an aluminum-based material, and contains a lubricant base oil and at least one of a phosphorus-containing carboxylic compound and a metal salt thereof (component (A)) at 0.001 to 1 mass % of the composition in terms of phosphorus. The composition may suitably be used as lubricant such as drive train lubricant for automatic or manual transmissions, grease, wet brake oil, hydraulic actuation oil, turbine oil, compressor oil, bearing oil, refrigerant oil, and the like used in apparatus having the sliding parts.

A carriage is moved in a direction including a Y axis component in order to move a turning process tool that is attached to a tool spindle along a horizontal line that is perpendicular to a Z axis, and thus, a turning process is carried out on a workpiece which is attached to a workpiece spindle.

Method for a memory including a first, second, third and fourth cells include applying a read, program, or erase voltage, the first and second cells coupled to a first top interconnect, the third and fourth cells coupled to a second top interconnect, the first and third cells coupled to a first bottom interconnect, the second and fourth cells are to a second bottom interconnect, each cell includes a switching material overlying a non-linear element (NLE), the resistive switching material is associated with a first conductive threshold voltage, the NLE is associated with a lower, second conductive threshold voltage, comprising applying the read voltage between the first top and the first bottom electrode to switch the NLE of the first cell to conductive, while the NLEs of the second, third, and the fourth cells remain non-conductive, and detecting a read current across the first cell in response to the read voltage.

A combination trimming/flame treatment end effector adapted for mounting to the end of a robotic arm. A trimming blade extends from a main body portion of the end effector for performing a trimming operation. The trimming blade may be mounted in an exchangeable cartridge to facilitate blade changing. Also extending from the main body portion is a flame treatment element for performing a flame treatment operation. The flame treatment element generally comprises a torch or burner. Because both the trimming blade and the flame treatment element are part of the same end effector, the robot simply manipulates the end effector such that the desired one of the trimming blade or the flame treatment element is properly positioned for use. As such, a tooling change can be avoided. While not restricted thereto, it is contemplated that an end effector of the present invention may be used to process vehicle bumper fascias.

The invention relates to a machine tool (1), comprising a plurality of fixed tool spindles (3) and such that can optionally be displaced from a retracted idle position to an extended working position and can be positioned at different positions in a frame-like rack (2), and a workpiece carrier (4) with at least one workpiece holder (5), with the workpiece (4) carrier being movable at least in several axes in a translational manner and preferably also in a rotational manner. In order to provide advantageous constructional conditions it is proposed that at least one of the tool spindles (3) is associated with a tool magazine (7) plus tool changer (8).

A system for loading/unloading sheets is disclosed, some of which also being of metal, and handling method thereof, serving a laser cutting center. The system includes a pair of rails (1, 2), supported at a preset height above a feeding tray (T) of the cutting center, whereon at least one Cartesian robotized hand is movably mounted, capable of moving along horizontal axes X and Y as well as along a vertical axis Z, mutually orthogonal, and including at least two bridge cranes (3, 4) sliding along the rails (1, 2) each of which supports at least one pair of robotized hands (5-8), and the robotized hands (5-8) have an electromagnetic pick-up head which may be coupled with a suction-cup device (103). Feeding tray (T) consists of bars whereon small tesserae (204) of ceramic material are fitted.

There is provided a component mounting apparatus, which includes: a nozzle which sucks a component; a nozzle supporting member, on which the nozzle is installed, which moves in a vertical direction with respect to an upper surface of a substrate on which the component sucked at the nozzle is mounted; an optical system which captures an image of a leading edge portion of the nozzle where the component is sucked in a component mounting operation, from a side direction, such that an optical axis of the optical system is inclined at a predetermined angle with respect to a sucking surface of the nozzle; and an analyzer which analyzes the image of the leading edge portion to determine whether a sucking state of the component sucked by the nozzle is normal or abnormal.

Device for managing the electrodes for electrical discharge machining EDM machine tools comprises at least one magazine (1) that has a series of individual housings (33) designed to accept and hold exchangeable elements (5) consisting of electrodes (6, 22) mounted on an electrode holder (11a, 11b), and a changer device (2) equipped with a gripper (2) intended to move the exchangeable elements (5) from the individual housings (33) towards the machine and vice versa. A first adapter piece (21) is associated with each of the exchangeable elements (5). This adapter piece (21) surrounds the electrode holder (11a, 11b) and is gripped around its periphery by the gripper (9) of the changer (2) so as to guarantee that the exchangeable element (5) is held precisely. The device further comprises a second adapter piece (32) associated with each of the individual housings (33) of the magazine (1) that are likely to be used.

A welding tip replacement apparatus is used for a welding torch that includes a tubular tip connection body, a tubular retaining member fitted over the tip connection body, and a tubular welding tip fitted within the tip connection body, the welding torch being configured such that displacing the retaining member toward the proximal end of the tip connection body along the axis of the tip connection body causes the welding tip axially fastened to the tip connection body to be released. The apparatus includes a first grasping mechanism grasping the retaining member, a second grasping mechanism grasping the welding tip protruding from the retaining member in a direction away from the distal end of the tip connection body, a first driving mechanism driving the first grasping mechanism axially, and a second driving mechanism driving the second grasping mechanism axially.

A combination component handling and connecting device connectable to a multi-axis robot for use in moving and connecting components and subassemblies includes a housing and an actuator fixedly connected to the housing. The actuator includes an actuating link movable from a first position to a second position. Connected to the actuating link is an end effector for concurrent movement with the actuating link. The component handling and connecting device includes a clamp having a first jaw and a second jaw. The second jaw is connected to the actuating link for selectively moving the second jaw toward the first jaw operative to engage a component.

A section member drilling or milling machine comprises a machine bed for supporting a workpiece to be drilled, the machine bed including guides for controllably sliding thereon a support comprising precision vertical guides thereon a platform is engaged, the platform comprising parallel horizontal guides slidably supporting a carriage, in turn supporting a cantilever arm, including a driving motor for controllably driving a drilling and milling tool along parallel guides of the cantilever arm.

A network component comprising at least one processor coupled to a memory and configured to exchange security information using a plurality of attributes in a management entity (ME) in an optical network unit (ONU) via an ONU management control interface (OMCI) channel, wherein the attributes provide security features for the ONU and an optical line terminal (OLT). Also included is an apparatus comprising an ONU configured to couple to an OLT and comprising an OMCI ME, wherein the OMCI ME comprises a plurality of attributes that support a plurality of security features for transmissions between the ONU and the OLT, and wherein the attributes are communicated via an OMCI channel between the ONU and the OLT and provide the security features for the ONU and the OLT.

The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

A system and method are disclosed for transporting deterministic traffic in a gigabit passive optical network. A system that incorporates teachings of the present disclosure may include, for example, an Optical Line Termination (OLT) for exchanging data traffic in a Gigabit Passive Optical Network (GPON) having a controller programmed to generate a timeslot schedule for transport of a desired bandwidth of constant bit rate (CBR) data traffic by selecting one or more timeslots from periodic frame clusters operating according to a GPON Transmission Convergence (GTC) protocol. Additional embodiments are disclosed.

A method and apparatus for controlling update of digital pre-distortion (DPD) coefficient is provided. The apparatus is applicable to a digital power control system, wherein the apparatus comprises: an update controlling unit configured to determine a group of fully-trained DPD coefficients among a plurality of DPD coefficients; and a DPD coefficient generating unit configured to update adaptively the group of fully-trained DPD coefficients according to the result of judgment of the update controlling unit. The DPD coefficients are allowed to be updated after being judged as being able to be fully trained according to power distribution information of DPD input signals, or according to address distribution information of an LUT, or according to average power of output of an HPA; otherwise, they may not be updated, thereby efficiently preventing DPD abnormality resulted from unfull training of coefficients in being updated.

Exemplary systems and methods for testing communication media and devices are disclosed herein. An exemplary system may include a transmitting media support and a receiving media support, each including a plurality of communication media. The system may further include a movement support configured to selectively translate the receiving media support relative to the transmitting media support between a transmission position and a free position. In the transmission position, a receiving media may be engaged with the transmitting media to receive an initiated signal from the transmitting media. In the free position, a first end face of the receiving media may be spaced apart from a second end face of the transmitting media, thereby preventing contact between the first and second end faces. The movement support may be further configured to align the at least one of the receiving media with the transmitting media.

The disclosure discloses an apparatus and method for rerouting multiple traffics. The apparatus includes a path computation unit and a traffic path incorporation unit, the path computation unit forwards a received uniform route computation notification message including multiple pieces of failed traffic connection information to the traffic path incorporation unit, and also forwards a route inquiry request transmitted from the head node of the fault traffic to the traffic path incorporation unit; the traffic path incorporation unit analyzes and detects the failed traffic connection information according to traffic incorporating and route inquiry statistic algorithm, and uniformly obtains and records the recovery route information from the path computation unit; when receiving the route inquiry request forwarded by the path computation unit, the traffic path incorporation unit is further configured to search the record according to the route inquiry request, and return the found corresponding recovery route information to the head node which requests the recovery through the path computation unit. The disclosure uses a incorporating and uniform route inquiry method, the resource loss of the path computation unit is reduced, and the efficiency of link restoration is improved.

An optical transceiver has a communications mode and an optical time domain reflectometer (OTDR) mode. The transceiver comprises a transmitter channel and a receiver channel operable, in the communications mode, to respectively transmit and receive communications signals through respective external optical fibers. The transceiver also comprises a guide arrangement for guiding, in the OTDR mode, a reflected OTDR signal along a path from the transmitter channel into the receiver channel. A method of obtaining test data for an optical fiber in an optical data communications subsystem is also disclosed.

Embodiments of the present disclosure provide methods for allocating bandwidth to a plurality of traffic containers of a passive optical network. The method comprises receiving upstream data from a plurality of traffic containers of the passive optical network and passing the upstream data to a traffic manager. The method further comprises dynamically changing the allocated bandwidth based at least in part on the amount of the upstream data stored in one or more queues of the traffic manager.

The invention provides optical interconnects of data-processing cores of multicore chips by means of digital planar holographic microchips. The method comprises delivering “N” laser lights to “N” data-processing cores on the host chip, coding the obtained optical signals by modulating them with the core-generated data, and then delivering the modulated and coded optical signals to a holographic microchip formed on the same substrate of the host chip as the data-processing cores, splitting the modulated and coded optical signals into (N−1)N modulated optical copy signals, delivering the copy signals to all data-processing cores except the one that generates the copy signals, and decoding the data obtained from the output signals delivered to the processing cores by the receivers. The method is efficient in that it allows replacing electrical interconnects between the cores with optical interconnects and can be matched to current semiconductor production technology.

A method of controlling consumer devices using an infrared dongle coupled to a mobile device includes receiving power for the infrared dongle from the mobile device. The infrared dongle includes an infrared transmitter coupled to a microcontroller. One or more instructions are received in the microcontroller from the mobile device. The received one or more instructions are generated from codes stored in a memory of the mobile device. In response to the receiving, one or more infrared signals are transmitted via the infrared transmitter to at least one of the consumer devices.

A transmitter and a receiver for an optical telecommunication system of the WDM type are disclosed. In one aspect, the transmitter uses a chromato-temporal encoder which, with each block of symbols to be transmitted, associates a code matrix, where each element of the matrix corresponds to a wavelength and a use of the channel. The transmitter includes multiple modulators, where each modulator modulates a laser beam at a wavelength during a use of the channel by an element corresponding to the code matrix. The beams modulated in this manner are multiplexed in an optical fiber. Another embodiment using both a wavelength and a polarization encoding is also proposed.

One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.

A fiber optic data transmission system includes an optical fiber and a data transmitter having a first laser having a first wavelength, a first phase modulator for phase modulating light from the first laser as a function of a first data input stream so as to create a first phase-modulated output data stream, a second laser having a second wavelength different from the first wavelength, and a second phase modulator for phase modulating light from the second laser as a function of a second data input stream so as to create a second phase-modulated output data stream. The transmitter also includes a combiner combining the first and second output data streams into a phase-modulated optical signal for transmission over the optical fiber.

Methods and apparatus related to the detection of low-rate visible light communication (VLC) signals and the recovery of information communicated by the VLC signals are described. Various methods and apparatus are well suited for embodiments in which a device, e.g., a smartphone, including a camera which uses a rolling shutter. The rolling shutter facilitates the collection of different time snapshots of a received low rate time varying VLC signal with different pixel rows in the image sensor of a frame corresponding to different time snapshots. In some embodiments, demodulation is used to recover and identify a single tone being communicated in a frame from among a plurality of possible alternative tones that may be communicated, each different tone corresponding to a different set of information bits.

A pre-emphasis control method includes calculating an average value of transmission characteristics based on transmission characteristics of a plurality of light beams received by a receiver, and determining that, among signals of the plurality of light beams, a wavelength with a deviation from the average value is a wavelength at which control is to be performed, determining that the wavelength at which control is to be performed and a wavelength adjacent thereto are a group of wavelengths at which control is to be performed, obtaining an average of transmission characteristics of the group of wavelengths at which control is to be performed, and based on a difference between averaged transmission characteristics and respective transmission characteristics of the group of wavelengths at which control is to be performed, changing a light intensity output from each transmitter that transmits a group of wavelengths at which control is to be performed.

Provided is a polarization separation device which converges filter coefficients used in polarization separating process more quickly. The polarization separation device according to the present invention comprises: a first filter means 11 which applies filtering process on each of first and second input signals, which are detected from an received optical signal, with elements of a characteristic matrix representing the inverse characteristics of an optical transmission path as filter coefficients, and uses each of the filtered signals to output a first output signal; a second filter means 12 which applies filtering process on each of the first and second input signals with the other elements of the characteristic matrix as filter coefficients, and uses each of the filtered signals to output a second output signal; a filter coefficient update means 13 which updates the first filter coefficients using a relation between the elements of the characteristic matrix so as to further reduce both error signals of the first and second output signals; and a filter coefficient update means 14 which updates the second filter coefficients using the relation between the elements of the characteristic matrix so as to further reduce both error signals to the first and second output signals.