Abstract: A communication network of the present invention includes: a plurality of superordinate nodes 110 to 1m0 forming a cascade type topology; and a plurality of terminal nodes 111 to 11n, connected to at least one superordinate node from among said plurality of superordinate nodes and forming a star type topology with the superordinate node connected.

Abstract: The wireless communication device of the present invention is provided with a received data FIFO for temporarily storing received data, and a data reading section for reading received data from the received data FIFO. The data reading section, when received data to be read is stored in the received data FIFO, reads and outputs the stored received data. Meanwhile, when the received data to be read is not stored in the received data FIFO and a predetermined condition is fulfilled, the data reading section outputs dummy received data. Furthermore, when the received data to be read is not stored in the received data FIFO and the predetermined condition is not fulfilled, the data reading section outputs an error.

Abstract: A signal receiving device is provided which can prevent the imbalance occurring between in-phase and quadrature signals. A polarity of a local oscillator output signal to be outputted from a local oscillator 13 is switched by a polarity switching unit 14 in a time division way. Each of signals outputted from the polarity switching unit 14 is frequency divided by a frequency divider 16. The frequency-divided local oscillation signal is supplied to a mixer 34. Frequency conversion of a receiving signal is performed by the mixer 34 which receives the signal and local oscillation signal to demodulate received data.

Abstract: The transmission of packets, in which data signals or control signals are stored in the payload of a packet comprising a payload and a header having a sequence number area for storing sequence numbers, is controlled. Data signal sequence numbers, which are added to a data packet storing data signals in a payload, are generated from a first communication device, are stored into each of the sequence number areas of the data packet, and are sent to a second communication device from the first communication device in order to control the transmission of the data packet on the basis of the data signal sequence numbers.

Abstract: The present invention comprising: a first local oscillator for generating a first frequency; a second local oscillator for generating a second frequency; phase-difference setting means for setting a first phase difference between a transmission signal and an output of the aforementioned first local oscillator; phase-difference detection means for detecting a second phase difference which is the phase difference between a reception signal and an output of the aforementioned second local oscillator, and calculation means for calculating a distance to a communication counterpart from a third phase difference and a fourth phase difference which are notified by the communication counterpart, and from the aforementioned first phase difference and second phase difference, wherein the third phase difference is set to the second frequency by the communication counterpart, and the fourth phase difference is set to the first frequency by the communication counterpart.

Abstract: A signal receiving device is provided which can prevent the imbalance occurring between in-phase and quadrature signals. A polarity of a local oscillator output signal to be outputted from a local oscillator 13 is switched by a polarity switching unit 14 in a time division way. Each of signals outputted from the polarity switching unit 14 is frequency divided by a frequency divider 16. The frequency-divided local oscillation signal is supplied to a mixer 34. Frequency conversion of a receiving signal is performed by the mixer 34 which receives the signal and local oscillation signal to demodulate received data.

Abstract: Means for a thermally conductive and electrically insulating material containing an AlN crystal mainly comprising AlN, and a production method thereof. In production, a molten aluminum layer is formed on an AlN substrate with at least its surface comprising AlN in an atmosphere of a non-oxidizing gas, and the molten aluminum layer is then heated in an atmosphere of N2 gas to form an AlN crystal which mainly comprises an AlN layer. The means are also a thermally conductive and electrically insulating material having an AlN crystal and an Al gradient layer, and a production method thereof. In production, a heating step of forming a molten aluminum layer on the AlN layer and heating it in an atmosphere of N2 gas is repeated at least twice or more. At this time, the amount of the N2 gas dissolved in the molten aluminum layer is decreased as the heating step is repeated.

Abstract: Means for a thermally conductive and electrically insulating material 1 containing an AlN crystal 150 mainly comprising AlN, and a production method thereof. In production, a molten aluminum layer is formed on an AlN substrate 11 with at least its surface comprising AlN in an atmosphere of a non-oxidizing gas, and the molten aluminum layer is then heated in an atmosphere of N2 gas to form an AlN crystal 150 which mainly comprises an AlN layer 125. The means are also a thermally conductive and electrically insulating material having an AlN crystal and an Al gradient layer, and a production method thereof. In production, a heating step of forming a molten aluminum layer 15 on the AlN layer 125 and heating it in an atmosphere of N2 gas is repeated at least twice or more. At this time, the amount of the N2 gas dissolved in the molten aluminum layer is decreased as the heating step is repeated.

Abstract: The present invention comprising: a first local oscillator for generating a first frequency; a second local oscillator for generating a second frequency; phase-difference setting means for setting a first phase difference between a transmission signal and an output of the aforementioned first local oscillator; phase-difference detection means for detecting a second phase difference which is the phase difference between a reception signal and an output of the aforementioned second local oscillator, and calculation means for calculating a distance to a communication counterpart from a third phase difference and a fourth phase difference which are notified by the communication counterpart, and from the aforementioned first phase difference and second phase difference, wherein the third phase difference is set to the second frequency by the communication counterpart, and the fourth phase difference is set to the first frequency by the communication counterpart.

Abstract: Molten aluminum is heated in the range of 900° C. to 1300° C. under a nitrogen atmosphere using magnesium as an auxiliary agent to form aluminum nitride directly on the molten aluminum and bond the aluminum nitride to the aluminum so that an Al—AlN composite material is formed. Because aluminum nitride power needs not to be sintered at high temperature equal to or higher than 1900° C., the Al—AlN composite material can be formed at low temperature in the range of 900° C. to 1300° C. compared with the high temperature equal to or higher than 1900° C., and thereby the high-density aluminum nitride can be obtained.

Abstract: A radio communication system comprises a parent node transmitting a beacon signal as one-to-many communication at every constant period, and a child node receiving the beacon signal, the parent node and the child node operating in synchronization with each other by using the beacon signal. The child node transmits a schedule notification signal for providing notification of presence/absence of a schedule of data transmission to the parent node, within a predetermined time period between the beacon signals. The parent node transitions into a sleep state until a time of transmitting the next beacon signal, when the parent node cannot detect the schedule notification signal in the predetermined time period.

Abstract: The present invention provides compensation for distortions in a multi-stage amplifier having a gain expansion characteristic. The present invention also provides an approach for using an amplification stage biased in a state close to B-class, which exhibits high power with added efficiency at low output, in order to have a gain expansion characteristic in all stages of a multi-stage amplifier. The amplifier of the present invention has a gain expansion characteristic which presents an increase in gain in response to an increase in input power or output power in a certain range of the input power or the output power.

Abstract: In a heat exchanger, a core portion includes a plurality of plate fins each shaped like a flat plate and a plurality of tubes in which a fluid flows and each of which is inserted into each of the plate fins to be mechanically bonded thereto. Further, an end portion in a longitudinal direction of each of the tubes is bonded to a header plate which constructs a part of a header tank. The manufacturing method for this heat exchanger includes inserting the tube into the plate fins; expanding the tube to attach the plate fins; connect the tube into the header plate; and vibrate the tube with respect to the plate while applying a load to the tube in the direction of the header plate.

Abstract: A communication network of the present invention includes: a plurality of superordinate nodes 110 to 1m0 forming a cascade type topology; and a plurality of terminal nodes 111 to 11n, connected to at least one superordinate node from among said plurality of superordinate nodes and forming a star type topology with the superordinate node connected.

Abstract: In an ultrasonic joining method for joining a flange portion of a first member to a portion of a second member, a first horn and a second horn are arranged on the flange portion on a side opposite to the second member, and the first horn is vibrated in a condition that the second horn is biased against the first horn and the first horn and the second horn are pressed against the flange portion such that the flange portion is vibrated while being pressed against the portion of the second member. Because the first horn is vibrated in a condition that the first horn and the second horn are pressed against each other at press-contact portions thereof, vibration of the first horn is transferred to the second horn through the press-contact portions.

Abstract: In an ultrasonic joining method for joining a flange portion of a first member to a portion of a second member, a first horn and a second horn are arranged on the flange portion on a side opposite to the second member, and the first horn is vibrated in a condition that the second horn is biased against the first horn and the first horn and the second horn are pressed against the flange portion such that the flange portion is vibrated while being pressed against the portion of the second member. Because the first horn is vibrated in a condition that the first horn and the second horn are pressed against each other at press-contact portions thereof, vibration of the first horn is transferred to the second horn through the press-contact portions.

Abstract: An ultrasonic welding method and an ultrasonic welding device are provided to join a first member having a substantial pipe shape and a second member at a joining surface by pressure-applying and vibration-exciting. In an arranging process, each of a first horn member and a second horn member is slantways arranged in such a manner that a part of a pressure-applying surface thereof which is nearer to a division surface thereof becomes nearer to the joining surface, according to deformation in a joining process. Thus, in the joining process, the pressure-applying surfaces are disposed substantially parallel to the joining surface due to a pressure-applying reaction force, so that the first horn member and the second horn member can be pressed against each other at the division surfaces thereof.

Abstract: An Al—AlN composite material, a heat exchanger and a related manufacturing method are disclosed. The Al—AlN composite material aluminum is manufactured by melting aluminum to allow a layer of melted aluminum to flow in an area over one surface of an AlN plate under an inactive gas atmosphere after which the layer of melted aluminum is solidified to form an Al plate bonded to the AlN plate. The heat exchanger includes the Al—AlN composite material forming at least part of a cooling medium flow passage with the AlN plate held in thermal contact with a heating body. The manufacturing method comprises melting aluminum to allow a layer of melted aluminum to flow in an area over one surface of an AlN plate under inactive gas atmosphere, and solidifying the layer of melted aluminum to form the Al plate bonded to the AlN plate.

Abstract: When a weld area of weld surface between a flange portion 3a of a pipe 3 and a flange portion 4a of a pipe connection member 4 is S and total energy consumed on the weld surface is Et, ultrasonic welding is carried out to produce said ultrasonic weld assembly in such a manner that an energy density E defined as the quotient obtained by dividing the total energy Et by the weld area S satisfies the relation 26.69e?0.3708P<E<240.9e?0.1445P with a surface pressure P on the weld surfaces of the flange portion 3a and the flange portion 4a. Preferably, ultrasonic welding is carried out in such a manner that the energy density E satisfies the relation 133.45e?0.3708P<E<240.9e?0.1445P.

Abstract: Means for a thermally conductive and electrically insulating material 1 containing an AlN crystal 150 mainly comprising AlN, and a production method thereof. In production, a molten aluminum layer is formed on an AlN substrate 11 with at least its surface comprising AlN in an atmosphere of a non-oxidizing gas, and the molten aluminum layer is then heated in an atmosphere of N2 gas to form an AlN crystal 150 which mainly comprises an AlN layer 125. The means are also a thermally conductive and electrically insulating material having an AlN crystal and an Al gradient layer, and a production method thereof. In production, a heating step of forming a molten aluminum layer 15 on the AlN layer 125 and heating it in an atmosphere of N2 gas is repeated at least twice or more. At this time, the amount of the N2 gas dissolved in the molten aluminum layer is decreased as the heating step is repeated.