Abstract: A crude drug ingredient having bactericidal activity incorporated into a curable composition comprising a (meth)acrylate type monomer, a polymerization initiator and if necessary a filler to formulate the ingredient into the drug having sustained release property. The curable composition containing the crude drug ingredient is applied to a defective part of a tooth or an artificial gum for preventing dental diseases such as carious tooth, pyorrhea alveolaris, and the like.

Abstract: A crude drug ingredient having bactericidal activity incorporated into a curable composition comprising a (meth)acrylate type monomer, a polymerization initiator and if necessary a filler to formulate the ingredient into the drug having sustained release property. The curable composition containing the crude drug ingredient is applied to a defective part of a tooth or an artificial gum for preventing dental diseases such as carious tooth, pyorrhea alveolaris, and the like.

Abstract: In a method and apparatus for double-talk detection in an echo canceller that uses an adaptive digital filter to estimate, from a received signal and a transmitted signal to which an echo signal of the received signal is added, the characteristics of an echo path and generate a simulated echo signal, and subtracts this echo replica from the transmitted signal in order to transmit a residual signal from which the echo signal has been removed, and which during the course of this operation detects the double-talk state according to a double-talk detection threshold and inhibits the estimation of adaptive digital filter; adaptive estimation and the double-talk detection threshold are controlled in accordance with the state of system e.g., whether it is in the single-talk state, whether the echo signal is active or idle, whether there are fluctuations in the echo path, or whether howling is taking place.

Abstract: An adaptive digital filter which is used, for instance, for a prediction filter in an ADPCM modulator and an ADPCM demodulator, for providing stable operation and minimum phase shift response. The filter (FIG. 4, FIG. 5) has three parallel branches (A,B,C), two (A,B) of them have a plurality of series connected non-recursive filter elements (A.sub.1 -A.sub.n, B.sub.1 -B.sub.n) each of which has degree not larger than three relating to an operator (Z.sup.-1), and third branch (C) is merely a conductive line. Tap coefficients (c.sub.1, c.sub.2, . . ., d.sub.1, d.sub.2, . . . ) of non-recursive filter elements change according to solutions of the transfer of the filter. A numerator and/or a denominator of the transfer function of the present filter is a Chebychev polynominal relating to an operator (Z.sup.-1), and has a zero point and/or a pole. The solutions (w.sub.i, v.sub.i) of a numerator and a denominator locate alternately on a unit circle (FIG. 6) on a Z.sup.-1 plane.

Abstract: An adaptive digital filter which is used, for instance, for a prediction filter in an ADPCM modulator and an ADPCM demodulator, for providing stable operation and minimum phase shift response has been found. The filter (FIG. 4, FIG. 5) has three parallel branches (A,B,C), two (A,B) of them have a plurality of series connected non-recursive filter elements (A.sub.1 -A.sub.n, B.sub.1 -B.sub.n) each of which has degree not larger than three relating to an operator (Z.sup.-1), and third branch (C) is merely a conductive line. Tap coefficients (c.sub.1, c.sub.2, . . . , d.sub.1, d.sub.2, . . . ) of non-recursive filter elements change according to solutions of the transfer function of the filter. A numerator and/or a denominator of the transfer function of the present filter is a Chebychev polynominal relating to an operator (Z.sup.-1), and has a zero point and/or a pole. The solutions (w.sub.i, v.sub.i) of a numerator and a denominator locate alternately on a unit circle (FIG. 6) on a Z.sup.-1 plane.

Abstract: A circulator comprises a cylindrical conductor housing, a disc shaped magnetic component mounted in said housing, three V-shaped inner conductors having two linear arms provided on the surface of said magnetic component, said inner conductors conjoining substantially at the center of said surface maintaining a 120-degree angle to each other, the open end of said V-shaped inner conductor being connected to the housing, and the other end of said V-shaped inner conductor being connected to an external strip line.

Abstract: An epoxy resin composition comprising[A] a novel copolymer produced by polymerizing a polymerizable material selected from the group consisting of(a) substituted or unsubstituted dicyclopentadiene;(b) a cationically polymerizable unsaturated hydrocarbon-containing fraction obtained by distilling a cracking or reforming product of a petroleum and having a boiling point in the range of -20.degree. C. to 280.degree. C.;(c) a cationically polymerizable vinyl aromatic hydrocarbon having 8 to 10 carbon atoms;(d) a mixture of two or three of ingredients (a), (b) and (c); and(e) a mixture of any one of ingredients (a) to (d) with a cationically polymerizable unsaturated aliphatic hydrocarbon having 4 to 10 carbon atoms in the presence of a cationic polymerization catalyst with a high-boiling product having a boiling point of at least about 150.degree. C. and an oxygen content of at least 0.

Abstract: A method for preparing a novel polymer which comprises polymerizing a polymerizable material selected from the group consisting of(a) substituted or unsubstituted dicyclopentadiene;(b) a cationically polymerizable unsaturated hydrocarbon-containing fraction obtained by distilling a cracking or reforming product of a petroleum and having a boiling point in the range of -20.degree. C. to 280.degree. C.;(c) a cationically polymerizable vinyl aromatic hydrocarbon having 8 to 10 carbon atoms;(d) a mixture of two or three of ingredients (a), (b) and (c); and(e) a mixture of any one of ingredients (a) to (d)with a cationically polymerizable unsaturated aliphatic hydrocarbon having 4 to 10 carbon atoms in the presence of a cationic polymerization catalyst; wherein a high-boiling product having a boiling point of at least about 150.degree. C. and an oxygen content of at least 0.