Patent application number | Description | Published |
20090074425 | OPTICAL TRANSMITTER AND CONTROL METHOD THEREOF - An optical transmitter which modulates the phases and intensities of double pulses and then transmits them, includes a branching section which branches each of the input double pulses to first and second paths, a first optical modulator placed in the first path, second and third optical modulators placed in series in the second path, and a combining section which combines the double pulses having traveled through the first path with the double pulses having traveled through the second path to output double pulses. A control section controls such that each of the first and second optical modulators performs any one of relative intensity modulation and relative phase modulation on the double pulses passing through, and the third optical modulator performs relative phase modulation on the double pulses passing through. | 03-19-2009 |
20090236501 | PHOTON DETECTION METHOD AND CIRCUIT HAVING PHASE ADJUSTER - A photon detection circuit in which photon detection is performed by applying gate pulses to a light-receiving element at predetermined periods, includes: a gate-period waveform averaging section that generates averaged waveform data by averaging sampled waveform data output from the light-receiving element in the individual predetermined periods; a phase shifting section that shifts at least one of the phases of the averaged waveform data and sampled waveform data so that a phase difference between the averaged waveform data and sampled waveform date disappears; and a discrimination section that discriminates a photon detection based on the phase-adjusted sampled waveform data relative to the phase-adjusted averaged waveform data. | 09-24-2009 |
20090262942 | Method and system for managing shared random numbers in secret communication network - A method for managing shared random numbers in a secret communication network including at least one center node and a plurality of remote nodes connected to the center node, includes: sharing random number sequences between the center node and respective ones of the plurality of remote nodes; when performing random numbers sharing between a first remote node storing a first random number sequence shared with the center node and a second remote node storing a second random number sequence shared with the center node, distributing a part of the second random number sequence from the center node to the first remote node; and sharing the part of the second random number sequence between the first remote node and the second remote node. | 10-22-2009 |
20090316910 | METHOD AND DEVICE FOR MANAGING CRYPTOGRAPHIC KEYS IN SECRET COMMUNICATIONS NETWORK - A cryptographic key management method and device are provided by which cryptographic keys of multiple nodes can be managed easily and stably. A system includes at least one first node and a plurality of second nodes connected to the first node, and the first node individually generates and consumes a cryptographic key with each of the second nodes connected to the first node itself. A cryptographic key management device in such a system has a monitor that monitors the stored key amounts of cryptographic keys of the individual second nodes, stored at the first node, and a key management control section that performs key generation control on the first node, based on the stored key amounts. | 12-24-2009 |
20100195831 | QUANTUM KEY DISTRIBUTION SYSTEM, OPTICAL TRANSMITTER, OPTICAL MODULATION CONTROL CIRCUIT, AND OPTICAL MODULATION CONTROL METHOD - In a quantum cryptographic transmitter ( | 08-05-2010 |
20110167299 | COMMUNICATION SYSTEM AND METHOD FOR CONTROLLING THE SAME - For an error rate QBER, threshold values are preset, including a threshold value Q | 07-07-2011 |
20110243331 | SHARED RANDOM NUMBERS MANAGEMENT METHOD AND MANAGEMENT SYSTEM IN SECRET COMMUNICATION NETWORK - In a secret communication network including a center node and multiple remote nodes, the center node is provided with a virtual remote node which functions as a remote node similar to each of the remote nodes. Random numbers shared between the center node and each remote node are managed based on random number sequences used in cipher communication between the virtual remote node and one of the remote nodes. | 10-06-2011 |
Patent application number | Description | Published |
20090211548 | VARIABLE VALVE DEVICE FOR ENGINE - A variable valve device, which is capable of automatically canceling a deviation in the relationship between the rotation angle of a control shaft and the lift degree generated because of the disassembling and assembling of an engine, includes a target lift degree calculator that calculates a target lift degree, a motor driver that drives a brushless DC motor that rotates the control shaft until the lift degree reaches the target lift degree, and an automatic deviation canceller that automatically cancels the deviation. More specifically, the magnetic pole pulse pattern of the motor before the engine starts is obtained and it is determined whether the pattern match magnetic pole pulse pattern stored before the engine stops. If they do not match, an idle lift degree is set, the idle lift degree is changed so that the engine speed is within the tolerance range of an idle engine speed, the rotation angle for the idle portion is subtracted from the obtained angle of the control shaft and a reference angle is updated by the difference. | 08-27-2009 |
20130191009 | MOTORCYCLE - A motorcycle includes a CPU (Central Processing Unit) of an ECU (Electronic Control Unit) that drives a fuel heating device when a fuel heating condition is satisfied and the result of a fuel heating prohibition determination process indicates that heating is permitted. On the other hand, the CPU does not drive the fuel heating device when the fuel heating condition is not satisfied or when the result of the fuel heating prohibition determination process indicates that heating is prohibited. In the fuel heating prohibition determination process, the CPU determines a tilted state of the motorcycle, and prohibits or permits heating of fuel in a fuel pipe by the fuel heating device based on a detection result of the tilted state. | 07-25-2013 |