Abstract: The present invention provides a technology of effectively avoiding tracing on a terminal performed with an identification number being a target and DoS attack without making any significant changes to a communication system. In the wireless communication system of the present invention, under a control of a control communication processing portion 113 of an access point, a hash function arithmetic operation processing portion 112 generates a third identification number to be updated using a current identification number, hash key and random number for any wireless communication terminal, a control communication processing portion 113 sends an update instruction signal containing the random number to the wireless communication terminal and updates the current identification number stored in the identification number storage portion 121 to a second identification number.

Abstract: In a random error signal generator, an M-sequence generation circuit outputs, in parallel, pieces of bit data stored in each register, a first generation circuit sequentially outputs first reference values C which are changed by a predetermined value in response to clocks, a second generation circuit outputs a second reference value D which is shifted from the first reference value C by a range value E which is determined depending on an error rate p. A comparison and determination unit outputs random error signals to be error bits when a numeric value A of the bit data output exists between the first and second reference values C, D. The random error signal has the error rate p, the number of times of error occurrences follows Poisson distribution, and a distribution of adjacent error occurrence intervals follows a geometric distribution.

Abstract: When an apparatus located at an edge of a network transmits a report message in a multicast procedure transmitted from a mobile terminal to a gateway switch, the apparatus snoops the report message and transmits an entry update request frame for causing an entry forming a transfer route for multicast to be learned in a direction of the gateway switch. The gateway switch transfers the received report message to a port to which an IP multicast router is connected after the transfer router for multicast is formed.

Abstract: An identification-information extracting unit extracts first identification information of a location registration area of a wireless communication system. A storage unit stores correspondence information concerning a relationship between the first identification information and second identification information of a location registration area managed by a communication network system. A location-registration requesting unit transmits location-registration request information for requesting a location registering device to perform a new location registration when the second identification information is updated by a movement of a mobile terminal.

Abstract: A degree of conformity of error distribution of a digital signal to the Poisson distribution is quantitatively determined. The digital signal including error data, which is randomly generated at a predetermined error rate, is divided into data number of measurement units, wherein the data number is determined on the basis of the error rate. A sample number of the measurement units are acquired from the measurement units, and the number of errors contained in each measurement unit is measured as a measurement value. Further, the number of times of occurrence of each measurement value is calculated, a Poisson distribution function is calculated, and a degree of a bond between the Poisson distribution and the distribution of the number of times of occurrence is determined by using the chi-square goodness-of-fit test method.

Abstract: An identification-information extracting unit extracts first identification information of a location registration area of a wireless communication system. A storage unit stores correspondence information concerning a relationship between the first identification information and second identification information of a location registration area managed by a communication network system. A location-registration requesting unit transmits location-registration request information for requesting a location registering device to perform a new location registration when the second identification information is updated by a movement of a mobile terminal.

Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.

Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.

Abstract: A layer 2 switch network system includes a terminal, an edge switch, and a Radius server that notifies the edge switch of a temporary MAC address allocated to the terminal. The edge switch stores therein swap data for associating the temporary MAC address with a real MAC address. When receiving a MAC frame from the terminal, the edge switch replaces the real MAC address of a source set in the MAC frame with the temporary MAC address of the source. When transmitting a MAC frame to the terminal, the edge switch replaces the temporary MAC address of a destination set in the MAC frame with the real MAC address of the destination.

Abstract: An M-sequence generator includes EXCLUSIVE-OR gates feeding back pieces of bit data from m number of series registers to the registers in response to a clock. A period of a cyclic group {(?1k), (?2k), (?3k), . . . } falls within a maximum period (2m-1), the group being produced as an element (?k) obtained by raising a root ? of a polynomial to a specified power value k (k?2), which have the terms in polynomials of a Galois field GF(2m). In a multiplying unit including the gates, pieces of bit data is fed into one end of the multiplying unit in response to the clock while the element (?k) is fed into the other end. The multiplying unit performs Galois field multiplication between each piece of bit data and the element (?k), the gate supplies the multiplication result as feedback bit data to the respective registers.

Abstract: In a random error signal generator, an M-sequence generation circuit outputs, in parallel, pieces of bit data stored in each register, a first generation circuit sequentially outputs first reference values C which are changed by a predetermined value in response to clocks, a second generation circuit outputs a second reference value D which is shifted from the first reference value C by a range value E which is determined depending on an error rate p. A comparison and determination unit outputs random error signals to be error bits when a numeric value A of the bit data output exists between the first and second reference values C, D. The random error signal has the error rate p, the number of times of error occurrences follows Poisson distribution, and a distribution of adjacent error occurrence intervals follows a geometric distribution.

Abstract: A degree of conformity of error distribution of a digital signal to the Poisson distribution is quantitatively determined. The digital signal including error data, which is randomly generated at a predetermined error rate, is divided into data number of measurement units, wherein the data number is determined on the basis of the error rate. A sample number of the measurement units are acquired from the measurement units, and the number of errors contained in each measurement unit is measured as a measurement value. Further, the number of times of occurrence of each measurement value is calculated, a Poisson distribution function is calculated, and a degree of a bond between the Poisson distribution and the distribution of the number of times of occurrence is determined by using the chi-square goodness-of-fit test method.

Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.

Abstract: An identification-information extracting unit extracts first identification information of a location registration area of a wireless communication system. A storage unit stores correspondence information concerning a relationship between the first identification information and second identification information of a location registration area managed by a communication network system. A location-registration requesting unit transmits location-registration request information for requesting a location registering device to perform a new location registration when the second identification information is updated by a movement of a mobile terminal.

Abstract: The present invention provides a technology of effectively avoiding tracing on a terminal performed with an identification number being a target and DoS attack without making any significant changes to a communication system. In the wireless communication system of the present invention, under a control of a control communication processing portion 113 of an access point, a hash function arithmetic operation processing portion 112 generates a third identification number to be updated using a current identification number, hash key and random number for any wireless communication terminal, a control communication processing portion 113 sends an update instruction signal containing the random number to the wireless communication terminal and updates the current identification number stored in the identification number storage portion 121 to a second identification number.

Abstract: According to some embodiments, systems for improved blower fans are provided. In some embodiments, systems may include a casing comprising an inlet to accept a fluid and an outlet to evacuate the fluid. The systems may further comprise an impeller disposed within the casing, comprising a hub and one or more impeller blades coupled to the hub. In some embodiments, the inlet of the casing may be shaped to reduce the amount of fluid that evacuates the casing via the inlet due to pressure within the casing.

Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.

Abstract: When an apparatus located at an edge of a network transmits a report message in a multicast procedure transmitted from a mobile terminal to a gateway switch, the apparatus snoops the report message and transmits an entry update request frame for causing an entry forming a transfer route for multicast to be learned in a direction of the gateway switch. The gateway switch transfers the received report message to a port to which an IP multicast router is connected after the transfer router for multicast is formed.

Abstract: A permanent magnet type motor comprising a rotor main body rotatably supported with respect to a stationary member, a rotor which is provided on an outer periphery face of the rotor main body and which is arranged such that S poles and N poles of a plurality of permanent magnets are provided alternately, a stator composed of a stator core arranged at the outer periphery side or inner periphery side of the rotor, the stator core having winding storage sections, and stator windings stored in the winding storage sections, a sensor fixed to the stationary member so as to be proximal to the permanent magnets, the sensor detecting a position of the permanent magnets, a detection target member having a detector for detecting a magnetic resistance change portion formed on the rotor main body, and a rotational position detecting magnetic sensor arranged at the stationary member.

Abstract: A decentralized key management scheme that implements key management of a tree structure comprised of only group members without using a key management server is proposed, and communication method and system that can contribute to secure group communications is provided. Each member constituting a group updates tree structure data of the entire group when a new member joins, respectively 70, and selects a captain in each subtree 71. Rather than the key management server, the captain generates a new key and shares it with other captains or the joining member 72, and distributes the new key to the members of the subtree 73, thereby enabling all the group members to update to the new key. A captain is also selected when a member leaves, and sharing and distribution of a new key by the captain is performed.