Abstract: An arbitrary signal is converted to IP packets, which are routed by an IP packet routing part to Optical path signal conversion parts. Optical path signals from the Optical path signal conversion parts are provided directly to an optical path route switching part of an IP packet transmission equipment. By the optical path route switching part, optical path signals, obtained by wavelength-demultiplexing of OTM signals from optical backbone transmission lines by OTM/optical path signal conversion parts, and optical path signals from the Optical path signal conversion parts are cross-connected to output routes according to their destinations.

Abstract: A nonlinear optical crystal allowing type 2 phase matching multiplexes a fixed wavelength light having an angular frequency &ohgr;D and a variable wavelength light having an angular frequency &ohgr;S, with the polarization directions thereof being perpendicular to each other, so as to produce a sum frequency light having an angular frequency &ohgr;D+&ohgr;S. When multiplexing the fixed wavelength light and the variable wavelength light through the nonlinear optical crystal, a controlling section controls the polarization direction of the fixed wavelength light so as to be parallel to a predetermined reference axis within a plane vertical to a phase matching direction of the nonlinear optical crystal. Even when the wavelength of inputted light is changed, the predetermined reference axis is a single axis which maintains parallelism with the crystal axis of the nonlinear optical crystal.

Abstract: A temperature meter for measuring temperature of a measurement target object to which a temperature sensor cannot be fixed directly is formed by a temperature sensor configured to measure an observed temperature in a vicinity of the measurement target object; a timer configured to measure a temperature observation time; and a calculation processor configured to calculate the temperature of the measurement target object according to the observed temperature and the temperature observation time by carrying out a prescribed calculation processing.

Abstract: In a hypertext made up of a plurality of linked documents, each document is composed of a document ID, an issuer ID, a property definition, and a signature attached to the document in its entirety. The property definition includes a property name 402, a value 403, a destination document ID 404, and a constraint definition part 405. By setting in the constraint definition part 405 a hash constraint 406 on the destination document 410, a schema ID constraint 407 defining the document type of the document 410, and a constraint 408 restricting the value of a particular property of the document 410, it is possible to make alterations in the contents of a signed document or attach a document and to prevent invalid alterations in the document contents or invalid attachment of a document.

Abstract: A semi-insulating InP substrate in which a Ru-doped semi-insulating semiconductor layer is formed on the surface is provided, wherein the Ru-doped semi-insulating semiconductor layer has a complete semi-insulating property. The semiconductor optical device is fabricated by forming the Ru-doped semi-insulating semiconductor layer on a Fe-doped semi-insulating InP substrate, and forming a semiconductor crystal layer to which a p-type impurity is doped.

Abstract: Signal channels are identified easily by uniquely correlating the port numbers of the optical time-division-demultiplexing unit with channel numbers. The extraction apparatus includes an optical time-division-demultiplexing unit that separates multiplexed signals into N channels and provides them to N separate ports, a channel extraction unit that is connected to N separate ports and extracts one channel number of the N channels, a channel switch that switches the N channels to the output ports of which port numbers uniquely match with the numbers of the N channels based on the relationship between the number of the one channel extracted and the output port number corresponding to the one channel number, and a data output unit that has N output ports and provides the signals of the switched N channels to the output ports of which port numbers match with the channel numbers.

Abstract: An adaptive array antenna transceiver apparatus provides: a local signal generator 24 that outputs a signal having a frequency that corresponds to the difference between the reception frequency and the transmitting frequency; a coupler 15 that separates and extracts a part of the signals from the output of the transmitters 13; a switch 21 that selects the signal output from any one of the transmitters 13; a frequency converter 22 that converts the frequency of the signal selected by the switch 21; and a switch 23 that inputs signals output by the frequency converter 22 and selectively outputs them to any one of the plurality of paths.

Abstract: A multistage Mach-Zehnder interferometer type optical circuit including any number of symmetrical Mach-Zehnder interferometers and any number of asymmetrical Mach-Zehnder interferometers connected in cascade. In the optical circuit, low coherence light is used first to obtain individual phase control conditions of the symmetrical Mach-Zehnder interferometers without being affected by the asymmetrical Mach-Zehnder interferometers. Second, phase control conditions of the individual asymmetrical Mach-Zehnder interferometers are obtained by controlling the symmetrical Mach-Zehnder interferometers based on the first phase control conditions.

Abstract: A locating system for determining a position of an object comprises a transmitting station that transmits a first ID signal containing a first identifier of this transmitting station; a receiving station that receives the first ID signal, measures the intensity of the first ID signal, and extracts the first identifier; a data management unit that stores and manages the intensity in association with the first identifier, the intensity and the identifier being supplied from the receiving station; and a positioning computer that estimates the position of the transmitting station using a first correcting formula defining a relation between the intensity and the distance, based on the data stored in the data management unit.

Abstract: A learning control information generation method in a web-based training system which uses the WWW for education is provided. The learning control information generation method includes the steps of specifying hypertext information which is processed first, requesting and obtaining the hypertext information, analyzing the hypertext information, and obtaining element information and link information, storing relations between the hypertext information, the element information and the link information by using list structure in a storage, detecting a relation which corresponds with a condition of a rule for generating learning control information necessary for the web-based training system from the stored relations, and executing an action of the rule and outputting the learning control information.

Abstract: An electro-optic sampling apparatus is provided to enable measurement on potentials of signals on the conductor of coaxial cable with high precision and with ease. Herein, an electric input connector inputs a measured electric signal, which is introduced to a conductive path such as a microstrip line. An electro-optic material (e.g., Bi12SiO20) that provides electro-optic effect such as Pockel's effect is fixed to a bare portion of the conductive path and is varied in birefringence ratio in response to strength of electric field caused by the conductive path through which the measured electric signal transmits. The conductive path is then terminated by a terminal device. Now, a laser beam is radiated toward the electro-optic material, wherein it is varied in polarization in response to variations of the birefringence ratio. Then, the laser beam is reflected by a dielectric mirror and is separated into two beams by a polarization beam splitter.

Abstract: This invention provides an optical amplifier and a control method for holding the gain profile constant using an optical amplifier equipped with an amplification medium where common rare-earth ions have been doped.

Abstract: In a method for permuting and dividing 16 pieces of k-bit data held in 4k-bit long registers T0, T1, T2 and T3, k being an integer, the data of each register Ti is ANDed with a desired one of mask data (00ffff00), (ff0000ff), (0000ffff) and (ffff0000), and such ANDs are ORed to obtain desired permuted data.

Abstract: An optical amplifier is implemented which can reduce its size and cost by using a smaller number of components. Signal light coupled by an optical combiner with pump light fed from a pumping light source is incident on an EDF (erbium-doped fiber) to be pumped and amplified by the pump light, is emitted from the EDF to be incident on a second optical circulator and output from its second port, passes through an optical component to be fed back to the second optical circulator and launched into the EDF from the second optical circulator, passes through the EDF again in the direction opposite to the first passing direction followed by passing through the optical combiner, and is output from the third port of a first optical circulator.

Abstract: The fingerprint recognition apparatus of this invention has a plurality of pixel units. Each pixel unit has a fingerprint sensor circuit including a sensor element for converting a three-dimensional pattern of a skin surface of a finger coming into contact with the element into an electrical signal, and a sensor circuit for processing the electrical signal converted by the sensor element and outputting predetermined data. Each pixel unit also has a fingerprint memory in which user's registered fingerprint data and a recognition circuit for collating the fingerprint data detected by the fingerprint sensor circuit with the registered fingerprint data. A control circuit controls the pixel units and totalizes recognition results.

Abstract: An unscheduled terminal unit is prevented from being connected to conference communication or a scheduled terminal unit is prevented from being not connected to the conference communication, and security of the conference communication is improved, and also, a conference server for interconnecting many terminal units is connected to a private branch exchange and reservation tables for using the conference server are provided in order to surely charge users for conference communication service. When an incoming call for requesting connection of the conference communication comes to the private branch exchange, the validation is identified by whether the incoming call has been registered in the reservation tables or not, and the connection is rejected for the invalid incoming call.

Abstract: A transistor structure is implemented which can achieve high current gain by causing electrons injected from an emitter to reach a collector. An InGaN graded layer, which is interposed between a p-type InGaN layer and an n-type GaN layer, includes an In composition that varies from 0% to 10%. A bandgap of the thin film structure is gradually reduced from the substrate side to the surface side. An AlN buffer layer is grown on an SiC substrate by 100 nm thick, followed by growing a Si-doped GaN layer used for forming an ohmic electrode. A Si-doped GaN layer (n-type GaN layer) is grown thereon, followed by growing an InGaN layer whose In composition is varied, and by growing, an Mg-doped InGaN (p-type GaN layer), thereby fabricating a heterojunction diode.

Abstract: A wavelength converter has a phase modulated periodically modulated structure, where a nonlinear optical coefficient is periodically modulated at a fundamental period &Lgr;0 and the phase of the modulation varies nearly continuously, and the phase variation of the modulation unit structure is repeated at a period &Lgr;ph (>&Lgr;0). A conversion efficiency is made maximum when a phase mismatch amount &Dgr;&bgr; equals 2&pgr;/&Lgr;0±2&pgr;i/&Lgr;ph (i=0, 1, . . . , n, where n is a positive integer), 2&pgr;/&Lgr;0±2&pgr;(2i+1)/&Lgr;ph (i=0, 1, . . . , n), or 2&pgr;/&Lgr;0+2&pgr;i/&Lgr;f (i=m, m+1, . . . .

Abstract: An input signal is time-frequency transformed, then the frequency-domain coefficients are divided into coefficient segments of about 100 Hz width to generate a sequence of coefficient segments, and the sequence of coefficient segments is split into subbands each consisting of plural coefficient segments. A threshold value is determined based on the intensity of each coefficient segment in each subband. The intensity of each coefficient segment is compared with the threshold value, and the coefficient segments are classified into low- and high-intensity groups. The coefficient segments are quantized for each group, or they are flattened respectively and then quantized through recombination.

Abstract: A scheme for identifying input gray-scale image data (F) having noise tolerance and distortion tolerance. The data (F) is composed of a set of gray levels representative of points that form an image.