Abstract: A logic module for embodying a wide combination of logic and sequential logic in response to a user's demand is divided into a combination circuit part and a sequential circuit part. The combination circuit part is divided into a first stage including a first and a second two-input multiplexers and a second stage. The respective input terminals of the first and second multiplexers are connected to output terminals of two-input AND gates and a first and second input terminals of the two-input AND gates are data and inverted data to select the desired data state. The respective first and second multiplexers have select control input terminals which are connected to an output of an exclusive OR gate having two inputs.

Abstract: This invention relates to an apparatus for retiming digital data transmitted at a high speed even though the phase of a binary data bit is not related to the phase of the static offset of a retiming clock pulse, the apparatus comprising: local clock pulse generation means 11 for generating and outputting local clock pulse FT; delayed clock pulse parallel generation means 12 for outputting, in parallel, n delayed clock pulses delayed sequentially by one cycle of local clock pulse FT; input data transition detection means 13 for outputting pulse DT each time the rising and falling carrier waves intersect in input data D; sequential logic parallel phase detection means 14 for providing clock pulse selection data by outputting sequential logic phases of the upper location of the pulse generated during input data transition and transition location of n delayed clock pulses; retiming clock pulse selection means 15 for outputting a retiming clock pulse according to the clock pulse selection data of the input delayed

Abstract: The invention is a method for controlling an echo canceller circuit including a data storage for storing a program for processing digital signals to cancel an echo in PCM encoded voice data, a plurality of digital signal processors each having a reset terminal and which are downloaded with the program which is executed by the plurality of digital signal processor to carry out removal of the echo in the PCM encoded voice data, and a one chip controller for performing control functions of the echo canceller.

Abstract: An all-optical signal processing apparatus of a non-linear fiber loop mirror type comprises a very high-speed all-optical switch that can be used as a reverse multiplexed switch in a high-speed time division optical communication. The apparatus includes a non-linear loop mirror for switching signal light by adjusting light using the non-linear effect of an optical fiber and the characteristics of a sagnac interferometer as the fundamental configuration. The all-optical switch is constructed so that another adjustment light having an appropriate time delay with respect to an existing adjusting light is additionally introduced in order to compensate for the limitation on the switching bandwidth imposed by the walk-off between adjusting and signal lights in a conventional non-linear optical fiber loop mirror. This compensates for the cross-talk of the noise signals due to DC components generated in the conventional apparatus.

Abstract: The present invention relates to a method of manufacturing microstructure by the anisotropic etching and bonding of substrates so as to manufacture mechanically functioning micro-structures in various forms by uniting the same or different substrate bonding technique and selective anisotropic etching technique. This invention manufactures a pyramidal optical divider or an optical divider with a pyramidal structure located on a quadrilateral pillar by bonding one substrate on a substrate different in the direction of crystallization and anisotropically etching them thereafter. This invention manufactures variously shaped nozzles by bonding those substrates crystallized in a different direction and anisotropically etching them so that substrates bonded by one photograph transferring process may form different etching holes.

Abstract: A locking apparatus for an optical frequency multiplex system, including a local oscillating unit for applying low frequency signals to individual light sources and thereby making center frequencies of the light sources dither, photocouplers for grouping dithering optical signals outputted from the light sources into a single signal, a resonator for aligning the signals coupled by the photocouplers with optical frequency slots, respectively, a photodetector for converting a reflection optical signal from the photocouplers into a current signal, and an optical frequency stabilizing controller for controlling the light sources on the basis of an error signal detected by the photodetector, whereby the error signal is extracted using the reflection output rather than the transmitting output of the resonator, thereby being capable of enhancing the extinction ratio and maximizing the number of multiplexing light sources.

Abstract: An apparatus for and a method of duplex operation and management for an SMX-1 system, capable of minimizing a failure of the system and ensuring the consistency of data between the contents of database and the data being currently operated by two operation management subsystem modules (OMMs) operated in a fashion that when a failure occurs in one of the OMMs, the other OMM executes the function to be executed by the one OMM. The OMMs are connected to the target system by a highway interface unit and connected to a remote signalling network operations system (SIGNOS) by an X.25 network using a modem, one of the OMMs being in service to execute a management of network resources and a management of states of signalling networks, while the other OMM being standby.

Abstract: A production method for ion-implanted MESFET having self-aligned LDD structure and T-type gate, that the reverse mesa portion is formed at a predetermined part of the channel region which the source and drain regions are formed at both side by using caps layer, the ion is injected between the source and drain regions and the channel region as the small energy and low concentration by using the reverse mesa as the mask, the source and drain regions of the low concentration is formed so that drain part has more broadly than source part, and the gate electrode and the source and drain regions of the low concentration are not contacted at the formed groove which is removed the surface of the reverse mesa portion or the reverse mesa portion.

Abstract: Disclosed is an optical switch device for totally reflecting an incident light therein in accordance with a change in refractive index occurring owing to current application, which is manufactured by the steps of: sequentially forming an optical waveguide layer, an n-InP clad layer and an n-InGaAs cap layer on a main surface of an n-InP substrate using an epitaxial growing; selectively etching the n-InGaAs cap layer to form an opening tapered downward; diffusing an impurity into the n-InP clad layer through the opening and into the n-InGaAs cap layer to a predetermined depth from a surface thereof so as to form a first impurity diffused region in the n-InP clad layer under the opening and to form a second impurity diffused region along the surface of the n-InGaAs cap layer; etching the layers on the optical waveguide layer using a mask to form a ridge-shaped waveguide; and forming electrodes on the n-InGaAs cap layer and an exposed surface of the n-InP clad layer and on a surface which is opposite to the main

Abstract: A wafer installing cassette for semiconductor manufacturing apparatus is disclosed, in which various sizes of wafer can be installed within a certain range. In the present invention, the wafer installing cassette includes two or more shelves each having a plurality of annular steps, and a shelf securing means for supporting the shelves, so that a plurality of wafers of different sizes can be loaded.

Abstract: A traffic output suppression apparatus and a method for preventing congestion in an asynchronous transfer mode network.

Abstract: A simultaneous optical compression and decompression apparatus having a simple symmetrical arrangement including a plurality of optical splitting/combining units capable of achieving simultaneous splitting and combining of optical signals in opposite directions, a plurality of optical delay units each arranged between adjacent ones of the optical splitting/combining units and adapted to delay the time taken for an optical signal to pass therethrough in each of opposite directions by a predetermined time, so as to reproduce the optical signal in accordance with a predetermined rule.

Abstract: A method for controlling an overload of a main processor by assigning to the main processor of a distributed switching system with a hierarchy structure a function of informing associated lower-level processors of an occurrence of the overload, an increase in call suppression, a decrease in call suppression and a release of the overload upon controlling the overload, and assigning to the lower-level processors a function of automatically calculating the number of calls to be processed in response to a demand of the main processor, and controlling traffic affecting the main processor on the basis of the result of the calculation, so as to maintain a stable service condition for the overload control interval.

Abstract: A method of controlling a television broadcasting call in an ATM switching system in which a television broadcasting service as one of B-ISDN services can be provided through an ATM switching network. The provision of the television broadcasting call in the ATM switching system is not performed by previously connecting all information transmission paths between a broadcasting source and a viewer (subscriber) but by connecting information transmission paths of the nearest switching modules between the broadcasting source and the viewer according to a requirement of the viewer under the condition that a semi-permanent connection is made between the broadcasting source and the ATM switching system. Therefore, the processing capability of the ATM switching system can be enhanced. The present invention can basically realize various B-ISDN services in the future.

Abstract: An optical controlled resonant tunneling oscillator utilizing an oscillation variation characteristic of a resonant tunneling oscillator in accordance with a negative differential resistance, a series resistance and a static capacitance varied with an intensity of light when the light is incident on a resonant tunneling device having a double barrier quantum well structure and a method for fabricating the same are disclosed. The oscillator can modulate the frequency 2 or 3 levels in response to an intensity of an incident light as compared with the method of a conventioal photoelectric system that modulates the frequency in response to ON/OFF of an electric signal, thereby simplifying the system. The oscillator controls the resonant tunneling at the high speed by light, thereby enabling processing a signal of tens to hundreds GHz.

Abstract: An apparatus for adjusting the channel width of a multi-channel fiber amplifier light source, including an erbium-doped optical fiber amplifier constructed to generate a spontaneously emitted, amplified noise beam under a condition that no optical signal is applied thereto, the amplifier being used as a light source for wavelength division multiplexing, namely, a fiber amplifier light source. By the angle-turned Fabry-Perot etalon filter and the fiber-optic beam expander, the channel width can be easily controlled without affecting the free spectral range and the power of output light.

Abstract: A transmit block up-converter is provided for processing a multiplexed signal including a transmit IF signal, a reference frequency signal, a switching signal, a level signal and a constant-current signal, which is provided through one transmitting line from an indoor unit in the very small aperture terminal remote station for satellite communication. The transmit block up-converter includes a demultiplexer for demultiplexing the multiplexed signal; a frequency up-converter for frequency up-converting the transmit IF signal from the demultiplexer in response to the reference frequency signal, switching signal and level signal; an amplifier for amplifying the output signal from the demultiplexer; and an impedance matching circuit for impedance matching and amplifying an IF signal received from an external unit, and for outputting the impedance matched and amplified signal through one receiving line.

Abstract: The present invention is a vertical resonant surface-emitting laser, and more particularly, a method for making a micro-laser that can be emitted to the upper surface of resonance structures by forming electrodes on the side surface of the resonance structures. By forming the electrodes injecting the current to the active layer on the side surface of resonators, the electrodes may be formed more easily on the fine micro-laser. Moreover, the current is more efficiently injected to the inside the active layer due to the side electrode surrounding an upper glass layer and emitter, and the laser may be operated even with a smaller start current, and serial resistance of the resonators may be reduced.

Abstract: A large capacity connectionless communication system and a method of large capacity connectionless communication, capable of achieving an application to both a public network and a private network by centralizing connectionless data in asynchronous transfer mode network and carrying out a routing of the centralized connectionless data by use of a separate connectionless cell switching unit having a rapid connection setup function and a function for maintaining the set-up connection.

Abstract: A frame phase aligner for a transfer system includes selection circuitry for selecting one of a plurality of input signal groups, which include data, a clock signal, an inverse clock signal and a frame synchronous signal, received from outside of the frame phase aligner. A selection signal generator provides the selection circuitry with a selection signal according to write data input from outside of the frame phase aligner, so that the selection circuitry selects one of the plurality of input signal groups according to the selection signal indicative of the setup environment of the transfer system. A control signal generator generates control clock signals and a retiming control signal in order to demultiplex selected data of the input signal group selected. A demultiplexer demultiplexes data selected to form parallel data, retimes the parallel data, and controls the phase of the parallel data according to the control retiming signal and the control clock signals output from the control signal generator.