摘要:
Systems and methods of securely communicating from a sender device to a receiver device on a communication channel are disclosed. One disclosed method is for securely communicating from a sender device to a receiver device on a main channel when an eavesdropper device is listening on an eavesdropper channel. The main channel has an signal-to-noise ratio SNRM, and the eavesdropper channel has a signal-to-noise ratio SNRE. The method comprises encoding a message at a physical layer with a secure error correcting code (SECC) to produce an encoded message, and transmitting the encoded message on the main channel. The SECC has a set of defined characteristics such that when the eavesdropper device is more than a predetermined distance Z from the sender, at least a predefined fraction of the message is unreliable, where the predefined fraction of unreliable bits renders the eavesdropper unable to reliable decode messages on the main channel.
摘要:
A top access leveler assembly for leveling a table by use of a pedestal guide barrel, a leveling adjustment screw, and an adjustment driver. The leveling adjustment screw has a lower end with a foot pad and an upper end that can be rotated by the use of an adjustment driver. The adjustment driver is positioned within a cavity of the pedestal guide barrel and is further operated by a knob guide barrel that employs the use of alignment channels to allow the knob guide barrel to be twisted into a position where a spring biases the knob upward to allow ease of rotation. Once the knob is raised, the leveling adjustment screw is accessed from the top wherein the alignment channels allow rotation of the adjustment driver in either a clockwise or counterclockwise direction for use in extending the foot pad beneath the base of the table. The alignment guides further allow for the depressing of the guide barrel into the cavity and with a slight rotation places the guide barrel in a recessed position when not in use. The knob guide barrel includes a knob having an upper surface that is designed to be flush with an upper surface of the pedestal base when not in use and extends above the upper surface of the pedestal base to allow ease of rotation.
摘要:
Systems and methods for selecting a puncturing pattern for a low density parity check (LDPC) code are disclosed. One such method comprises: selecting a puncture pattern distribution for the LDPC code; calculating a security threshold and a reliability threshold for the LDPC, the LDPC having the selected puncture pattern distribution and also described by a degree distribution; storing the selected puncture pattern distribution responsive to a security gap for the LDPC being a lowest value encountered in any prior iterations; selecting another puncture pattern distribution for the LDPC code; and repeating the calculating, the storing, and the selecting another puncture pattern distribution steps.
摘要:
An item that might be lost is provided with a badge featuring an array of glass beads. In seeking to retrieve such a lost item, an atmospheric-penetrating beam of laser is directed into the search area, and the signals from a reflectometer are monitored. The item having the badge of the array of glass beads is more easily retrievable when lost or mislaid than an item without such badge.
摘要:
The invention is a magnetic knife sheath that permits easy transport and protection of knives in a relatively small sheath. The sheath has two magnetically charged faces that attract each other, protecting and holding the knife blade securely between them.
摘要:
The invention relates to the beneficiation of both natural and artificial titaniferous ores, specifically ilmenites by adding to the ores a fluoride, preferably a normally insoluble fluoride in an amount such that the percentage of fluorine ion relative to the titania values lies between 13% and 50%, adding to the mixture hydrochloric acid, the fluorine ions acting as an activating agent. After dissolution, the titanium is precipitated out, as a mixture of titanium dioxide, titanium oxy hydroxy fluoride and titanium oxy fluoride, the iron values largely remaining in solution.