Patents by Inventor Kam Chan
Kam Chan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7874519Abstract: Methods and apparatus for a spacecraft (1) orbiting about a celestial body such as the Earth to reacquire operational three-axis orientation with respect to that body.Type: GrantFiled: February 22, 2007Date of Patent: January 25, 2011Assignee: Space Systems/Loral, Inc.Inventors: Bruce Brumfield, Xenophon H. Price, George E. White, Philip C. Hirschberg, Kam Chan
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Publication number: 20070228218Abstract: Methods and apparatus for a spacecraft (1) orbiting about a celestial body such as the Earth to reacquire operational three-axis orientation with respect to that body.Type: ApplicationFiled: February 22, 2007Publication date: October 4, 2007Inventors: Bruce Brumfield, Xenophon Price, George White, Philip Hirschberg, Kam Chan
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Patent number: 7277384Abstract: A program and a method for a gateway are provided to deny incoming calls to prevent overload. The program provides a maximum CPU utilization threshold CPUT, which is set by the user. When a new incoming call is presented to the packet telephony gateway, the program checks a present CPU utilization CPUP. If the present CPU utilization CPUP is greater than the threshold, the call is refused. This insures that sound quality of the calls currently being handled is maintained, and that existing calls are never dropped.Type: GrantFiled: April 6, 2000Date of Patent: October 2, 2007Assignee: Cisco Technology, Inc.Inventors: Kam Chan, Mathew Lodge, Shoou Jiah Yiu
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Publication number: 20070065155Abstract: A system and a method for quantum key distribution between a transmitter and a receiver over wavelength division multiplexing (WDM) link are disclosed. The method includes providing one or more quantum channels and one or more conventional channels over the WDM link; assigning a different wavelength to each of the one or more quantum channels and each of the one or more conventional channels; transmitting single photon signals on each of the one or more quantum channels; and transmitting data on each of the one or more conventional channels. The data comprises either conventional data or trigger signals for synchronizing the transmission of the single photon signals on the quantum channels. All channels have wavelengths around 1550 nm. The WDM link can be a 3-channel WDM link comprising two quantum channels for transmitting single photon signals and one conventional channel for transmitting conventional data or triggering signals.Type: ApplicationFiled: September 19, 2005Publication date: March 22, 2007Applicant: The Chinese University of Hong KongInventors: Yuhui Luo, Kam Chan
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Publication number: 20070065154Abstract: A system and a method for quantum key distribution over a multi-user wavelength division multiplexing (WDM) network are disclosed. The system comprises a tunable or multi-wavelength transmitter; a plurality of receivers, each assigned a receiving-wavelength; and a multi-user WDM network linking the transmitter to the receivers. The transmitter can select a receiver among the receivers to be communicated therewith and transmit quantum signals to the selected receiver over the WDM network. The quantum signals are at a wavelength equal to a receiving-wavelength of the receiver. Therefore the WDM network allows quantum signals to be communicated between the transmitter and the receivers by wavelength routing.Type: ApplicationFiled: September 19, 2005Publication date: March 22, 2007Applicant: The Chinese University of Hong KongInventors: Yuhui Luo, Kam Chan
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Publication number: 20060288062Abstract: Disclosed is an all-fiber optical quantum random number generator, an optical coupler having an input port and two output ports; a single photon source connected to the input port, emitting a single photon which is transmitted from the input port to the output ports; a single photon detector connected to each of the two output ports, detecting the photon coming out from either of the output ports; and means for generating random numbers according to the detection result of the single photon detector. The generator of the invention can generate truly random numbers.Type: ApplicationFiled: June 16, 2006Publication date: December 21, 2006Applicant: The Chinese University of Hong KongInventors: Yuhui Luo, Kam Chan
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Publication number: 20060261197Abstract: An electric spice mill comprising a power unit coupled to the motor of the mill, the power unit comprising: (i) first and second electric circuits; (ii) a switch in electrical contact with said first and said second electric circuits; and (iii) an actuator movable between first and second positions, wherein, in the first position, the actuator prevents current flow in the first electric circuit and, in the second position, the actuator allows a first current to flow in the first electric circuit and the switch is responsive to the first current in the first electric circuit to allow a second current to flow in the second electric circuit such that the grinding unit of the mill is driven by the motor.Type: ApplicationFiled: May 18, 2005Publication date: November 23, 2006Applicant: Trudeau Corporation 1889 Inc.Inventors: Kit Chan, Kam Chan, George Bigelow
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Publication number: 20050067977Abstract: A new fluorescent lamp comprises a lamp tube and an electronic ballast, it is characterized in that it is provided with an outer tube, there are respectively an outer plug at both ends of the outer tube, in which inserts a socket for the lamp tube. The electronic ballast is between the outer plug and the socket for the lamp tube at one end, said lamp tube is disposed between two sockets for the lamp tube.Type: ApplicationFiled: July 28, 2003Publication date: March 31, 2005Inventors: Kam Chan, Wai Ng
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Patent number: 6142422Abstract: A method for inertially aligning a spacecraft along an axis, comprising the steps of using quaternion feedback control to reorient the spacecraft, and during the step of reorienting, using rate integrating gyroscopes in a pulse rebalance loop. The method operates to orient the spacecraft along an inertial direction of interest by the steps of operating a sensor to provide an initial fix on the inertial direction of interest; repetitively determining a difference between a commanded quaternion and a quaternion estimated based on sensed angular rates; and selectively applying torques to the spacecraft so as to drive the difference towards zero such that a spacecraft vector is aligned with the inertia direction of interest, thereby orienting the spacecraft. One mode of operation maintains the spacecraft fixed in orientation, while another mode of operation rotates the spacecraft about the direction of interest by using a bias-rate blind quaternion propagation technique.Type: GrantFiled: June 21, 1999Date of Patent: November 7, 2000Assignee: Space Systems/Loral, Inc.Inventors: Jeffery D Stoen, Kam Chan
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Patent number: 6083517Abstract: An antibacterial cleaning composition comprising about 0.05 to about 1 wt. % of a cationic polymer having a charge density of 0.0025 or higher, about 0.2 to about 10 wt. % of an alkylpolyglucoside having a formula: R--O(-G).sub.n wherein R is an alkyl group having from about 8 to about 22 carbon atoms, G is a saccharide residue having 5 or 6 carbon atoms and n is a number from 1-10, about 0.2 to about 5% of a zwitterionic surfactant and about 0.2 to about 5 wt. % of a biquanide compound, the composition having a pH of 7.5 or greater.Type: GrantFiled: September 26, 1997Date of Patent: July 4, 2000Assignee: Lever Brothers Company, division of Conopco, Inc.Inventors: Kavssery Ananthapadmanabhan, Kam Chan, Dale Grinstead, Carol Vincent
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Patent number: 6068217Abstract: A method for inertially aligning a spacecraft along an axis, comprising the steps of using quaternion feedback control to reorient the spacecraft, and during the step of reorienting, using rate integrating gyroscopes in a pulse rebalance loop. The method operates to orient the spacecraft along an inertial direction of interest by the steps of operating a sensor to provide an initial fix on the inertial direction of interest; repetitively determining a difference between a commanded quaternion and a quaternion estimated based on sensed angular rates; and selectively applying torques to the spacecraft so as to drive the difference towards zero such that a spacecraft vector is aligned with the inertia direction of interest, thereby orienting the spacecraft. One mode of operation maintains the spacecraft fixed in orientation, while another mode of operation rotates the spacecraft about the direction of interest by using a bias-rate blind quaternion propagation technique.Type: GrantFiled: September 22, 1997Date of Patent: May 30, 2000Assignee: Space Systems/Loral, Inc.Inventors: Jeffery D Stoen, Kam Chan
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Patent number: 6000661Abstract: A feedback motion compensation (FMC) component for use in a spacecraft having a payload. The FMC component includes a controller having sensor data inputs and an open loop dynamics model that is driven by actuator commands to produce a high accuracy attitude estimate suitable for payload motion compensation.Type: GrantFiled: September 22, 1997Date of Patent: December 14, 1999Assignee: Space Systems/Loral, Inc.Inventors: Xen Price, Kam Chan, Jeffery Stoen
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Patent number: 5996942Abstract: A method in accordance with this invention for maintaining a spacecraft in a desired orbital configuration, comprises the steps of: (a) recording a history of yaw momentum stored in momentum wheels; (b) estimating an average inertial torque and momentum over a previous time interval (such as one day); (c) determining a desired change in inertial torques using PID control law; (d) commanding a change in satellite trim tab and solar array position from a desired change in solar torque; and (e) slewing the trim tab and solar array a desired amount.Type: GrantFiled: September 22, 1997Date of Patent: December 7, 1999Assignee: Space Systems/Loral, Inc.Inventors: Xen Price, Kam Chan
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Patent number: D422729Type: GrantFiled: July 28, 1999Date of Patent: April 11, 2000Assignee: Bright Wing Industrial LimitedInventors: Kam Chan Chiu, Chi Ming Wong