Abstract: An information signal detection device and an information signal detection method are disclosed with which it is possible to transmit information by means of a DTMF signal using a channel that is prone to distortion, such as a high-efficiency channel. The information signal detection device comprises a filter bank component and a logic component. The filter bank component receives via a channel an information signal in which are superposed sine waves of two different frequencies selected from a specific number of frequencies sent by the sender, and generates binary information patterns showing in binary information whether the signal components of the various frequencies of this information signal are present. The logic component recognizes the end of the signal region when the binary information pattern generated in the binary information pattern generation step is containing no binary information showing that a signal component is present continuously for a specific period of time.

Abstract: A speech signal coding apparatus inputs a pitch period generated by coding a speech signal, and outputs information on a range for said pitch period, together with the pitch period. A speech signal decoding apparatus inputs the pitch period and the above information on the range, and determines whether or not the pitch period is within the range. When the pitch period is determined to be within the range, the speech signal decoding apparatus outputs the above pitch period. When the pitch period is determined not to be within the range, the speech signal decoding apparatus outputs as a pitch period a predetermined value within the range.

Abstract: A speech coding system is provided where input speech is coded by finding via an evaluation computation a code vector giving a minimum error between reproduced signals obtained by linear prediction analysis filter processing, simulating speech path characteristics, on code vectors successively read out from a noise codebook storing a plurality of noise trains as code vectors and an input speech signal and by using a code specifying the code vector. In the speech coding system, the noise codebook includes a delta vector codebook which stores an initial vector and a plurality of delta vectors having difference vectors between adjoining code vectors. In addition, provision is made in the computing unit for the evaluation computation of a cyclic adding unit for cumulatively adding the delta vectors to virtually reproduce the code vectors.

Abstract: A CELP type speech coding system is provided with an arithmetic processing unit which transforms a perceptual weighted input speech signal vector AX to a vector .sup.t AAX, a sparse adaptive codebook which stores a plurality of pitch prediction residual vectors P sparsed by a sparse unit, and a multiplying unit which multiplies the successively read out vectors P and the output .sup.t AAX from the arithmetic processing unit. In addition, the CELP type speech coding system includes a filter operation unit which performs a filter operation on the vectors P, and an evaluation unit which finds the optimum vector P based on the output from the filter operation unit, so as to enable reduction of the amount of arithmetic operations.

Abstract: Disclosed is a voice coding/decoding system having a transmitting part for transmitting a coded signal of an input voice signal at a bit rate lower than a predetermined transmission bit rate and a receiving part for receiving and decoding the coded signal transmitted from the transmission part. To enable the coding and transmitting of an input voice signal in an optimum state without passing through a buffer memory and without having a negative influence on the coder, the transmitting part provides coders for coding the input voice signal and groups of entropy coders. The inputs of the entropy coders in each group are connected to the output of one of the plurality of coders. The transmitting part further provides an evaluation part for evaluating the characteristics of the outputs of the coders and the entropy coders.

Abstract: An apparatus for controlling the intensity and on/off status of an incandescent light bulb as a function of the proximity of an object to a sensing plate. The frequency of a signal is varied from a nominal value when the presence of the object is sensed. A pulse is generated having a duration proportional to the time over which the signal if varied from its nominal frequency. The duration of the generated pulse, in relation to a pulse of predetermined width, is used to control a gated oscillator. The output of the gated oscillator is counted. The count obtained is used to control the operation of a TRIAC, which in turn connects power to the incandescent bulb.

Abstract: Fiber reinforced cement is continuously prepared by forming a conveyor by connecting a plurality of suction boxes each having a perforated plate, contacting the perforated plates of the suction boxes with a filter cloth and moving the suction boxes with the filter cloth at a synchronous speed, feeding a cementitious slurry and a fiber on the filter cloth, removing excess water by suction from the cementitious slurry through a suction trough connected to a suction device, and releasing the suction on the suction boxes to separate the filter cloth from the perforated plates of the suction boxes.

Abstract: An apparatus for continuous liquid-solid separation has suction boxes which respectively have a suction hole on a rear surface and a perforated surface at a front surface and said suction boxes being connected in series to form a conveyor and said suction holes being connected to a suction trough so as to give the sucking condition of the suction boxes in the zone of the suction trough wherein a filter cloth is contacted with the perforated surfaces of the suction boxes and is held by side plates which can be closed and opened at both sides of the suction boxes and the filter cloth and the suction boxes are moved at the synchronized velocity under suction.

Abstract: A process for preparing glass fiber-reinforced cement sheets by dewatering a slurry wherein at least one member selected from asbestos, cotton, flax, hemp, wool, or silk fibers is added to the aqueous cement-glass fiber slurry. The sheets so produced have increased bending strengths and improved peeling resistance.