Abstract: When a transmission-line driver circuit that transmits a signal to a transmission line is supplied with a power-supply voltage from a power-supply circuit, the value of the power-supply voltage is controlled based upon the amplitude of a signal output from the transmission-line driver circuit. For example, the maximum value of a signal input to the transmission-line driver circuit in time units delimited at fixed time periods is detected, the target value of power-supply voltage supplied to the transmission-line driver circuit is decided based upon the maximum value, and the power-supply circuit is controlled in such a manner that the target value of power-supply voltage and actual value of power-supply voltage will agree.

Abstract: A digital subscriber line communicating system and a transceiver therein are disclosed. The system or the transceiver comprises: a unit for calculating a bitmap which defines the number of transmissible bits for each carrier signal in each of periodical noise durations and a rate converter for converting a constant rate of an input transmitting data into a rate determined by the bitmap, and for adding, in a predetermined number of the periodical noise durations, dummy bits to the data having the converted rate. The bitmap calculating unit includes: a line quality measuring unit for measuring the quality of the communication line in each of the periodical noise durations, a transmission bit number converter for calculating the number of transmissible bits to be allocated to each carrier to form the bitmap, and a bitmap optimizing unit for minimizing the dummy bits by decreasing the number of the transmissible bits allocated to each carrier signal of the symbols.

Abstract: A digital subscriber line communicating system and a transceiver therein are disclosed. The system or the transceiver comprises: a unit for calculating a bitmap which defines the number of transmissible bits for each carrier signal in each of periodical noise durations and a rate converter for converting a constant rate of an input transmitting data into a rate determined by the bitmap, and for adding, in a predetermined number of the periodical noise durations, dummy bits to the data having the converted rate. The bitmap calculating unit includes: a line quality measuring unit for measuring the quality of the communication line in each of the periodical noise durations, a transmission bit number converter for calculating the number of transmissible bits to be allocated to each carrier to form the bitmap, and a bitmap optimizing unit for minimizing the dummy bits by decreasing the number of the transmissible bits allocated to each carrier signal of the symbols.

Abstract: In a catalyst for exhaust gas purification which comprises (a) a NOx absorbent material which absorbs NOx in an exhaust gas in an environment of excess oxygen whose exhaust gas oxygen concentration level is high, whereas, when the exhaust gas oxygen concentration level becomes lower in a given temperature range, the NOx absorbent material releases the absorbed NOx and (b) a precious metal, the exhaust gas purification catalyst further comprises an oxygen storage material which releases a larger amount of oxygen in the given temperature range in comparison with other temperature ranges. As a result of such arrangement, the NOx absorption efficiency of the NOx absorbent material in an environment of excess oxygen of high exhaust gas oxygen concentration level, i.e., the lean NOx purification rate thereof, can be improved.

Abstract: A subscriber communication machine is provided with an off-synchronous detector detecting off-synchronization of communication with an office communication machine, a correlation processor correlatively processing received data received over a communication line and held data having been transmitted from the office communication machine when the off-synchronization is detected by the off-synchronous detector, and a resychronous controller specifying a synchronous timing by the correlation process in the correlation processor to establish resynchronization in the communication with the office communication machine. When subscriber communication machine cannot keep synchronization with a transmission cycle in a predetermined transmission system such as TCM or the like in steady communication, it is possible to promptly resume the communication without necessity for initializing all over again.

Abstract: The present invention provides a catalyst for purifying an exhaust gas having excellent heat resistance and a small level of deterioration of the purifying ability of the exhaust gas even if the catalyst is exposed to a high temperature atmosphere for a long time. The catalyst for purifying an exhaust gas comprises a catalytic metal for oxidizing HC and CO and reducing NOx for purification, and a mixed oxide containing Ce, Zr and Sr.

Abstract: In a training method in a time domain equalizer provided in a digital data transmission system for updating tap coefficients in the time domain equalizer so that an error between the tap coefficients and channel target characteristic becomes zero, the training method includes steps of: obtaining a first sum of the tap coefficients of the channel target characteristic before a rectangular window is provided to the tap coefficients, and storing the first sum in a memory; obtaining a second sum of the tap coefficients of the channel target characteristic after the rectangular window was provided to the tap coefficients; subtracting the second sum from the first sum, and dividing a resultant value of subtraction by the numbers of the tap coefficients existing within the rectangular window; and obtaining each of tap coefficients of the channel target characteristic by adding a divided value to each tap coefficient existing within the rectangular window.

Abstract: An engine control device, which is adapted for an engine provided with an NOx-absorbing material arranged in an exhaust passage for absorbing NOx in an oxygen-rich atmosphere, and releasing NOx and absorbing sulfur content when the oxygen concentration drops, includes a discriminator for judging whether the amount of sulfur absorbed by the NOx-absorbing material has reached a prescribed quantity, and a reductant concentration controller which increases the temperature of the NOx-absorbing material by decreasing a quantity related to EGR ratio for desulfurizing the NOx-absorbing material based on the result of judgment made by the discriminator. When the quantity related to the EGR ratio is decreased, the temperature of exhaust gas increases. Consequently, the temperature of the NOx-absorbing material increases and the sulfur in the NOx-absorbing material is freed and released.

Abstract: An analog/digital integrated subscriber circuit includes a power supply part supplying power with respect to a subscriber line, and a signal processing part carrying out a signal processing. The power supply part is provided with a D.C./D.C. converter which controls an ON-time of a switching by detecting an output voltage and an output current supplied to the subscriber line. The D.C./D.C. converter includes a switching mechanism for switching a power supply characteristic of the power supply part to a constant current characteristic up to a maximum output voltage when supplying the power with respect to a digital subscriber line and to a constant voltage characteristic having a voltage lower than the maximum output voltage when supplying the power with respect to an analog subscriber line.

Abstract: A digital adaptive equalizer equalizes received signals through digital filtering operations by changing filtering coefficients. It comprises a coefficient calculating unit for calculating the filtering coefficients by using one kind of parameters, such as distance, as an input to a function corresponding to the filtering coefficients and a filtering operation executing unit for executing digital filtering operations based on the filtering coefficients. A variable lag filter for adjusting the phase delay of received received signals is provided. A coefficient converting unit calculates a part or all of tap coefficients of the filter using at least one piece of timing control information.

Abstract: An initial gain of an automatic equalizer is fixed to a predetermined value. Then, the most appropriate gain of the automatic equalizer is determined when a training signal is received by the automatic equalizer. An echo replica signal produced by an echo canceler is multiplied by the value obtained by dividing the most appropriate gain by the initial gain. Thus, the echo replica signal is corrected to cancel the echo signal included in the output of the automatic equalizer. The sampling rate of the A/D converter used in the transmitter and receiver is shifted by a predetermined value from the transmission line rate at an initial training stage. Thereafter, the sampling rate of the A/D converter is determined to be near that of the transmission line.

Abstract: An ISDN interface circuit is provided which is coupled to a terminal device via a transmission line and a reception line, the transmission line being formed of a pair of first and second wires, and the reception line being formed of a pair of third and fourth wires. The ISDN interface circuit includes a first resistor and a second resistor connected in series at a first node and between the first and second wires of the transmission line, and a third resistor and a fourth resistor connected in series at a second node and between the third and fourth wires of the reception line. The ISDN interface circuit also includes a D.C. power source connected to one of the first node, at which the first resistor and the second resistor are mutually connected in series and the second node, at which the third resistor and the fourth resistor are mutually connected in series. One of the first node and the second node, other than the above-mentioned one of the first node and the second node connected to the D.C.

Abstract: A tri-level digital-analog converter includes a first analog signal generating circuit for generating a first analog signal which corresponds to a "+1" level of a digital input signal, a second analog signal generating circuit for generating a second analog signal which corresponds to a "-1" level of the digital input signal, a third analog signal generating circuit for generating a third analog signal which corresponds to a "0" level of the digital input signal, and a selector coupled to the first, second and third analog signal generating circuits for selectively outputting one of the first, second and third analog signals in response to the digital input signal as an output analog signal. This tri-level digital-analog converter is suited for use in an oversampling analog-digital converter.

Abstract: Disclosed is a digital adaptive filter and a method of cancelling an echo component generated by a partial return of a transmission signal to a receiving side. The digital adaptive filter comprises: a main memory unit for storing a first echo replica which can be stored or read by using the parallel signal from a main tap unit as an address signal, at least one submemory unit for storing a second echo replica which can be stored or read by using the parallel signal from said subtap unit as an address signal, and an adding circuit for adding the first echo replica and the second echo replica. The second echo replica stored in the at least one submemory unit has a greater precision than the precision of the first echo replica stored in the main memory unit, and thus the accumulated error due to memory division can be reduced.