Abstract: A waveform analysis unit divides digital data of a video signal stored in a Y memory and a C memory into small blocks, and conducts average value separation and normalization on each of the small blocks. A 1/f fluctuation measuring unit first derives a self-correlation function for each of the normalized small blocks, folds back the self-correlation function to the negative side, and conducts correction processing for making an average self-correlation function over a predetermined section equal to 0. Subsequently, the 1/f fluctuation measuring unit conducts Fourier transform on the corrected self-correlation function, derives a power spectrum, and conducts straight line approximation of the power spectrum. The 1/f fluctuation measuring unit then derives a fluctuation value of the power spectrum from the approximate straight line.

Abstract: An optical wavelength division multiplexed signal amplifying repeater capable of doubling the number of wavelength division multiplexed signals that can be transmitted is disclosed. Optical signals of both 1.3 &mgr;m band and 1.55 &mgr;m band in the entered optical wavelength division multiplexed signals are amplified, while pumping lights capable of causing Raman amplification in the 1.3 &mgr;m band are coupled with the optical wavelength division multiplexed signals so as to cause the Raman amplification for the optical signals of the 1.3 &mgr;m band, such that a difference between the loss in the 1.3 &mgr;m band and the loss in the 1.55 &mgr;m band due to the optical fibers are compensated. An optical communication transmission line using such repeaters is also disclosed.

Abstract: An alarm propagation model of a transmission line is expressed by an equation. A fault portion on the transmission line is estimated by using the alarm propagation model. As a result, it is possible to estimate the fault portion by minimum observation time without lack of precision.

Abstract: A mobile communication system includes a first and second systems. Each of the first and second systems has a land station and at least one mobile terminal capable of communicating with the land station. The land station of the first system has a broadcasting channel transmission unit for transmitting status information via a broadcasting channel, and the mobile terminal of the second system has a broadcasting channel receiving unit for receiving information in the broadcasting channel to obtain a broadcasting channel receiving condition and the status information, a giving interference estimation unit for estimating giving interference level onto communication of the first system by the second system based upon the obtained broadcasting channel receiving condition and the obtained status information, and an output signal level control unit for controlling output signal level of the mobile terminal of the second system based upon the estimated giving interference level.

Abstract: A motion vector candidate selector selects candidate motion vectors for a MB to be coded based on the allowable calculation amount supplied from a controller. A predictive motion vector determinator determines an optimum predictive motion vector from among the candidate motion vectors. A statistical amount measuring unit determines the variance of motion vectors from among the motion vectors already determined. A search area determinator determines the size of the search area based on the allowable calculation amount. Also, a predictive motion vector periphery searcher determines the shape of the search area from the variance of the motion vectors, sets the size of the shape to the value determined by the search area determinator, and with the optimum predictive motion vector as an origin, searches the search area. An optimum motion vector is determined from among the motion vectors thus searched.

Abstract: A diffraction grating is disposed adjacent to a ridge waveguide formed on a substrate (cladding). Assumed that a light propagation direction at the waveguide is z, a direction of width of the waveguide is x, and ends of the diffraction grating of this embodiment is x=gmin when z=0 and x=gmax when z=L/2, the ends of the diffraction grating can be expressed as the following functions f(z). Namely, f(Z)=gmin+(gmax−gmin)×(2z/L)n when 0≦z≦L/2, and f(Z)=gmin+(gmax−gmin)×(2-2z/L)n when L/2≦z≦L, where n>1.

Abstract: A similar document retrieval method capable of realizing an improved retrieval performance. In this similar document retrieval method for retrieving similar documents of a reference document from a plurality of retrieval target documents, similarities of each one of the plurality of retrieval target documents with respect to the reference document are calculated by using each one of two or more similarity calculation methods separately, and the similar documents of the reference document are retrieved by carrying out a discrimination analysis with respect to each one of a plurality of similarities calculated by using each one of the two or more similarity calculation methods separately.

Abstract: An array antenna apparatus for use in spread spectrum communications is provided including a plurality of antenna elements aligned on a straight line. The array antenna apparatus is used in a receiving station for receiving spread-spectrum modulated radio signals having a wavelength of a predetermined carrier frequency transmitted from transmitting stations using a two-dimensional RAKE receiving method, and for performing spread spectrum communications in code division multiple access. The plurality of antenna elements are aligned such that an interval between antenna elements adjacent to each other among the plurality of antenna elements is set to a value which is larger than one half the wavelength of the carrier frequency and which is equal to or smaller than sixteen times the wavelength of the carrier frequency so as to generate grating lobes.

Abstract: A control signal superimposer for superimposing a control signal on a signal light, comprising a pumping light source for generating a pumping light with intensity fluctuation in accordance with the control signal; a Raman amplification medium pumped by the pumping light from the pumping light source for Raman-amplifying the signal light; a combiner for combining the pumping light output from the pumping light source and the signal light to be Raman-amplified and then supplying them to the Raman amplification medium; and an optical filter for extracting the signal light component from the output light of the Raman amplification medium and terminating the pumping light component.

Abstract: An optical amplifying transmission system comprising a first optical amplifying transmission line including a first optical amplifier, a second optical amplifying transmission line including a second optical amplifier, a pumping light generator for generating pumping lights to be supplied to said first and second amplifiers, the powers of the pumping lights being variable, and first and second terminal stations which connect respectively to both ends of said first and second optical amplifying transmission lines.

Abstract: A feed line connecting circuit for selectively connecting first, second and third feed line connecting terminals under a predetermined current feeding condition comprises a first current detector connected between one of the first and second feed line connecting terminals and a central node for detecting a current over a predetermined value; a first switch connected between the one of the first and second feed line connecting terminals and the central node for connecting said one of the first and second feed line connecting terminals to the central node under an unpowered condition; a selective switch controlled by the first current detector, the selective switch having first and second contacts and a common contact connected to the third feed line connecting terminal, the common contact being connected to the first selective contact when the first current detector does not detect a current over the predetermined value, and to the second selective contact when the first current detector detects a current over

Abstract: The present invention provides a semiconductor memory capable of retaining information after removing a power supply and of storing information with an optical input. A memory cell is comprising an n-InP substrate, a first semiconductor (n-InGaAs) layer, a second semiconductor (i-InGaAs) layer, a third semiconductor (p-InGaAs) layer, a fourth semiconductor (i-InGaAs) layer and a fifth semiconductor (n-InGaAs) layer. The first to fifth semiconductor layers are stacked in this order on the n-InP substrate. A bias voltage is applied between the n-InP substrate and the fifth semiconductor layer to control a height of a TBD formed in the above multi-layer structure so that carriers may move and electrons can be stored in one of the second and fourth semiconductor layers.

Abstract: There is provided a transmission line switch-over control system capable of significantly improving the nonoperational situation such as circuit disconnection during call or call quality deterioration without conducting unnecessary switch-over of a circuit or a transmission line.A line quality input data handler 5 acquires at least one transmission line quality data out of a received level, a received C/N, and a bit error rate of a normal transmission line 3 and sends it to a forecaster 6. The forecaster 6 produces estimated data of situation of transmission line based on the input quality data of the transmission line. A switch-over controller 7 presumes possibility that the line quality will deteriorate within a predetermined time such as, for example, the mean call holding time. If the presumed possibility of deterioration is larger than a predetermined decision threshold, the switch-over controller effects control so as to switch over the normal transmission line 3 to a back-up transmission line 4.

Abstract: An apparatus for combining signals includes RAKE receivers 10, 20, noise-power measuring apparatuses 30, 40, and a branch combiner 50. The RAKE receivers 10, 20 are the same in number as the antenna branches, and each RAKE receiver combines received signals by using a weight based on an amplitude of each received signal. Each of the noise-power measuring apparatus 30, 40 measures a sum of an interference power and a background-noise power in an output signal from each RAKE receiver. The branch combiner 50 multiplies the output signal from each RAKE receiver by an inverse of the sum measured by the noise-power measuring apparatus, and then adds up the value obtained by each multiplication.

Abstract: In an optical fiber transmission line between two terminal stations, an input side wavelength converter for up-shifting a wavelength of a signal light is inserted at a front part of each of the optical amplifiers and an output side wavelength converter for down-shifting a wavelength of a signal light is inserted at a rear step of the optical amplifiers. Signal lights transmit in a wavelength band shorter or longer than the zero dispersion wavelength of the transmission optical fiber on said transmission optical fibers. The input side wavelength converter converts the wavelength of the signal lights from the transmission optical fibers within the amplifying bandwidth of the optical amplifiers and the output side wavelength converter returns the wavelength of the signal lights optically amplified by the optical amplifiers.

Abstract: An optical processor comprising, a semiconductor saturable absorber; a current source for injecting a current to the semiconductor saturable absorber; a signal light introducer for introducing a signal light to the saturable absorber; a control light introducer for introducing a control light having a wavelength not longer than the wavelength of the signal light into the semiconductor saturable absorber; an assist light introducer for introducing an assist light having a wavelength longer than the wavelength of the signal light into the semiconductor saturable absorber; and a signal light extractor for extracting the signal light after treatment by the semiconductor saturable absorber.

Abstract: A 1.3 .mu.m-band optical amplifier includes an optical amplifying fiber doped with Yb ion for emitting light in 1.02 .mu.m band by pumping of the 0.98 .mu.m band light and Pr ion for amplifying signal light by pumping of the 1.02 .mu.m band light. Both ends of the optical amplifying fiber are connected to optical fiber gratings for selectively reflecting 1.02 .mu.m band light via matching connecting members and tapered core optical fibers. The optical fiber gratings form a 1.02 .mu.m-band resonator. A Wavelength Division Multiplexing (WDM) optical coupler multiplexes the signal light and pumping light from an pumping laser and supplies the thus-multiplexed light to the optical fiber grating. The pumping laser comprises a laser device which causes laser oscillation at 0.98 .mu.m. A 1.5 .mu.m-band optical amplifier having a similar configuration is also disclosed.