Abstract: A hollow poppet valve has an internal cavity which extends from within its valve head into a valve stem portion and is partly filled with a coolant. A manufacturing method includes forming a coolant rod by cutting clayish coolant to a coolant rod of a predetermined length from the coolant material extruded from an extruder; a coolant-rod insertion step in which a coolant rod is inserted into a cavity formed in an intermediate valve product through its opening; and a step of sealing the opening of the hole. In the coolant-rod insertion step, coolant-rods are inserted into the cavity separately in multiple times. Since each coolant rod is short, it is little deformed or bent, so that it has little interference with the inner periphery of the cavity, which permits use of a thick rod and increase the amount of the coolant in the cavity.

Abstract: A composite rolling mill roll according to the present invention includes: a steel roll shaft; and an outer layer provided around the roll shaft, in which the outer layer includes a sintered body including a base metal which is an iron alloy, a fibrous inclusion which consists of a ceramic and has an average diameter of 1 to 30 ?m and an average aspect ratio of 10 to 500, and a particulate inclusion which consists of a ceramic and has an average diameter of powder 1 to 100 ?m, an amount of the fibrous inclusion is 5 to 40 volume % relative to the volume of the sintered body, and an amount of the particulate inclusion is 5 to 30 volume % relative to the volume of the sintered body.

Abstract: A method of manufacturing a hollow poppet valve capable of storing a large amount of a coolant in an internal cavity (S) of the valve, which cavity extends from within its valve head (14) into a valve stem portion (12) and is filled with a coolant (19) together with an inert gas. The method comprises steps of: (i) forming a coolant rod (19a) of a predetermined length from a linear clayish coolant (19) to extruded from an extruder (20); (ii) inserting a coolant-rod into a cavity formed in an intermediate valve product (11) through its opening; and (iii) sealing the opening of the hole (S). In the step (ii), a coolant-rod may be divided into a shorter and thicker multiple pieces (19a, 19b) for divisional insertion into the cavity (S) in multiple times, so that they have little interference with the inner periphery of the cavity (S).

Abstract: While a first device controller is executing an interference quantity measuring process under control of a general controller, a wireless communication device is always brought into a state that it transmits a radio wave (dummy frame) by control of a second device controller. The first device controller executes channel selecting process for selecting one of the plurality of candidates of a communication channel A as the communication channel A based on the plurality of interference quantities (corresponding to the plurality of candidates of the communication channel A) obtained at the time of the execution of the interference quantity measuring process.

Abstract: A wireless access point device that is connected to one or more wireless client terminals and communicates with each of the wireless client terminals by using one of a plurality of bandwidths, and includes a transmission managing unit that individually determines a transmission rate with respect to each of the connected wireless client terminals; and a used bandwidth determining unit that calculates an approximation of a system communication capacity on the basis of the transmission rate and the number of the connected wireless client terminals and determines a bandwidth to be used by subjecting the approximation to determination based on a threshold.

Abstract: A composite rolling mill roll according to the present invention includes: a steel roll shaft; and an outer layer provided around the roll shaft, in which the outer layer includes a sintered body including a base metal which is an iron alloy, a fibrous inclusion which consists of a ceramic and has an average diameter of 1 to 30 ?m and an average aspect ratio of 10 to 500, and a particulate inclusion which consists of a ceramic and has an average diameter of powder 1 to 100 ?m, an amount of the fibrous inclusion is 5 to 40 volume % relative to the volume of the sintered body, and an amount of the particulate inclusion is 5 to 30 volume % relative to the volume of the sintered body.

Abstract: When an error correction decoding unit 26 of a data reception device 2 fails in error correction decoding of a codeword, an MIMO processing unit 15 of a data transmission device 1 deforms transmitted codewords according to a predetermined rule, and transmits the codewords, and the error correction decoding unit 26 of the data reception device 2 reproduces data by using the deformed codewords. As a result, not only the noise but the interference wave components can be reduced, and the success rates of the demodulation and error correction decoding can be improved greatly.

Abstract: A method selects antennas in an OFDMA wireless network including a base station and a mobile station. The mobile station measures a channel state of a downlink in a downlink subframe using different subsets of available antennas, and selects a subset of receive antennas for downlink reception based on the channel states between the base station and the different subsets of antennas at the mobile station. The base station measures the channel state in an uplink using an uplink subframe received in the base station from the mobile station, and selects a subset of transmit antennas for mobile station's uplink transmission based on the channel states between the base station and different subset of antennas at the mobile station.

Abstract: A conventional optical disk apparatus detects the amount of shift of an objective lens with a tracking error signal and an RF signal, and controls, when an optical pickup is moved, the shift amount for performing high-speed seek and high-speed access. The problem here is that this apparatus cannot be applied to an optical disk having an area where no RF signal is recorded, and requires higher costs. In view of this, an optical disk apparatus of the present invention has a shift signal detecting portion that detects a shift signal based on a push-pull signal generated during generation of a tracking error signal based on the reflected light resulting from a beam reflected from an optical disk, and a shift amount control portion that drives, when an optical pickup is moved, an objective lens actuator based on the shift signal detected by the shift signal detecting portion.

Abstract: When an error correction decoding unit 26 of a data reception device 2 fails in error correction decoding of a codeword, an MIMO processing unit 15 of a data transmission device 1 deforms transmitted codewords according to a predetermined rule, and transmits the codewords, and the error correction decoding unit 26 of the data reception device 2 reproduces data by using the deformed codewords. As a result, not only the noise but the interference wave components can be reduced, and the success rates of the demodulation and error correction decoding can be improved greatly.

Abstract: An order-ensemble searching unit classifies a distribution of reception signals at each bit position of a modulation symbol, and searches an order ensemble of a parity check matrix that minimizes an SNR threshold value. A code generating unit generates a parity check matrix and a generation matrix, based on the order ensemble obtained as a search result.

Abstract: A radio base station allocates, when performing a real-time Internet-protocol data communication, up-link radio resources, based on basic information of transmission data, so that the transmission data is transmitted in synchronization with a codec cycle of a mobile communication terminal in a concentrated manner, and notifies a result of allocating the up-link radio resources to the mobile communication terminal as an up-transmission schedule. A mobile communication terminal controls transmission of a radio frame based on the up-transmission schedule.

Abstract: A method and system enables and improves performance of hybrid automatic repeat request (HARQ) operations on channels between stations of an orthogonal frequency division multiple access (OFDMA) wireless communication network. There, the number of parallel HARQ channels is increased adaptively, and one connection identifier is used to unambiguously identify a set of MAC protocol data units (MPDUs) communicated over parallel HARQ channels. A sequence number is used to avoid out-of-order MPDU delivery when MPDUs are transmitted over parallel HARQ channels. The MPDUs can be concatenated or encapsulated. The maximum number of the parallel HARQ channels can be increased to 256, and can be negotiated when a station enters or re-enters the network.

Abstract: Within a communication system in which an ARQ control is exercised, in a transmission-side communication apparatus 11, a transmission scheduling unit 113 determines a transmission amount to be transmitted to a reception-side communication apparatus 21; an erasure correction encoding unit 112 performs an erasure correction encoding process on an information packet group that is made up of a plurality of packets to be transmitted so as to generate one or more erasure correction coded packets that fit the transmission amount instructed by the transmission scheduling unit 113 and specifies the one or more erasure correction coded packets as a unit of delivery confirmation; and a modulating unit 115 transmits a transmission data signal that has been generated by performing a predetermined modulation process on each of the erasure correction coded packets.

Abstract: In a communication apparatus, a grouping unit determines an adaptability based on a reception quality notified by a mobile station located in a cell, and groups mobile stations or connections by each of adaptabilities; an adaptability-based frame-occupancy-rate determining unit determines a data-mapping amount (an available capacity) by each of the adaptabilities depending on an amount of interference; and a frame mapping unit controls the mobile stations or the connections grouped by each of the adaptabilities to be mapped to a wireless frame by each frame based on the determined data-mapping amount.

Abstract: A method selects antennas in an OFDMA wireless network including a base station and a mobile station. The mobile station measures a channel state of a downlink in a downlink subframe using different subsets of available antennas, and selects a subset of receive antennas for downlink reception based on the channel states between the base station and the different subsets of antennas at the mobile station. The base station measures the channel state in an uplink using an uplink subframe received in the base station from the mobile station, and selects a subset of transmit antennas for mobile station's uplink transmission based on the channel states between the base station and different subset of antennas at the mobile station.

Abstract: A method and system enables and improves performance of hybrid automatic repeat request (HARQ) operations on channels between stations of an orthogonal frequency division multiple access (OFDMA) wireless communication network. There, the number of parallel HARQ channels is increased adaptively, and one connection identifier is used to unambiguously identify a set of MAC protocol data units (MPDUs) communicated over parallel HARQ channels. A sequence number is used to avoid out-of-order MPDU delivery when MPDUs are transmitted over parallel HARQ channels. The MPDUs can be concatenated or encapsulated. The maximum number of the parallel HARQ channels can be increased to 256, and can be negotiated when a station enters or re-enters the network.

Abstract: An order-ensemble searching unit classifies a distribution of reception signals at each bit position of a modulation symbol, and searches an order ensemble of a parity check matrix that minimizes an SNR threshold value. A code generating unit generates a parity check matrix and a generation matrix, based on the order ensemble obtained as a search result.

Abstract: A radio base station allocates, when performing a real-time Internet-protocol data communication, up-link radio resources, based on basic information of transmission data, so that the transmission data is transmitted in synchronization with a codec cycle of a mobile communication terminal in a concentrated manner, and notifies a result of allocating the up-link radio resources to the mobile communication terminal as an up-transmission schedule. A mobile communication terminal controls transmission of a radio frame based on the up-transmission schedule.

Abstract: A conventional optical disk apparatus detects the amount of shift of an objective lens with a tracking error signal and an RF signal, and controls, when an optical pickup is moved, the shift amount for performing high-speed seek and high-speed access. The problem here is that this apparatus cannot be applied to an optical disk having an area where no RF signal is recorded, and requires higher costs. In view of this, an optical disk apparatus of the present invention has a shift signal detecting portion that detects a shift signal based on a push-pull signal generated during generation of a tracking error signal based on the reflected light resulting from a beam reflected from an optical disk, and a shift amount control portion that drives, when an optical pickup is moved, an objective lens actuator based on the shift signal detected by the shift signal detecting portion.