Abstract: A bit rate-independent optical receiver ensures transparency with respect to changes of the transmission format and its associated bit rate in relation to an optical communications system. The optical receiver includes an opto-electric converter for converting an input optical signal into an electric signal, an amplifier circuit for amplifying the electrical signal, a bit rate-sensing circuit for generating a sensing signal with a voltage level determined on the basis of the bit rate of the electrical signal, a bit rate-recognition circuit for generating a recognition signal further amplified from the sensing signal, and a clock/data recovery circuit for reproducing a clock signal and data from the amplified electrical signal in accordance with a control signal.

Abstract: The provided forward error correction (FEC) apparatus for a transmission system includes a low pass filter (LPF) passing only a low frequency component of an input signal having a predetermined transmission rate; an AC power meter converting an energy value of an signal output from the LPF into a DC voltage value; a logarithm amplifier converting the exponentially varying DC voltage value from the AC power meter into a linear logarithmically varying DC voltage value; a digital signal processor (DSP) determining the transmission rate of the input signal according to a magnitude of the linear DC voltage value and outputting a control signal according to the transmission rate; a clock generator receiving the control signal and generating a clock signal according to the control signal; and a FEC module receiving the clock signal and performing FEC operation on the received signal. A method for FEC is also provided.

Abstract: An optical add-drop multiplexer is disclosed. The optical add-drop multiplexer includes a first loop for dropping a first polarized light signal having a corresponding wavelength from a multiplexed downstream optical signal and adding a second polarized light signal having a corresponding wavelength to a multiplexed upstream optical signal and a second loop for adding a first polarized light signal having a corresponding wavelength to the downstream optical signal input from the first loop. An upstream optical signal is output in which a second polarized light signal having a corresponding wavelength is dropped from towards the first loop and the multiplezer also includes a Bragg grating placed between the first and second loops for reflecting the first and second polarized light signals having the corresponding wavelengths respectively towards the first and second loops.

Abstract: A reciprocating compressor includes a case to which a suction pipe and a discharge pipe are respectively connected, having a closed space; a reciprocating motor disposed inside the case, for generating a reciprocating force; a compressing unit receiving the reciprocating force generated from the reciprocating motor, for compressing a fluid; and a separation plate for dividing the closed space of the case into a low pressure portion into which a fluid is sucked through the suction pipe and a high pressure portion from which a fluid compressed in the compressing unit is discharged. Accordingly, the reciprocating compressor cuts off vibration generated from the compressing unit and the reciprocating motor and thus reduce the vibration transmitted to the compressor case and other elements so that noise can be reduced, life spans of other elements can be lengthened, and reliability of the compressor can be improved.

Abstract: A duo-binary optical transmitter tolerant to a chromatic dispersion includes a pre-coder for generating a first 2-level signal from input binary data and generating a second signal having a waveform obtained by inverting the first signal, a Mach-Zehnder Modulator (MZM) for generating a Differential Phase Shift Keying (DPSK) modulated optical signal by modulating an input light according to the first signal and the second signal, and a Delay Interferometer (DI) for splitting the DPSK modulated optical signal into a first split signal and a second split signal, delaying the second split signal, and generating a duo-binary optical signal by interfering the first split signal with the second delayed split signal, wherein a time required for delaying the second split signal is set to 0.5˜0.8 bit.

Abstract: This invention provides an optical transmission with a demultiplexer for demultiplexing an input optical signal into optical signals of different channels and a multiplexer for multiplexing the optical signals outputted from the demultiplexer.

Abstract: A cross-connect device in an optical network which includes a demultiplexer for demultiplexing an input optical signal by channels; a plurality of arbitrary transmission optical receivers for converting the optical channel signals received from the demultiplexer to electrical signals and for recovering a clock signal and data according to a reference clock signal generated at the transmission rate of the electrical signals; a cross-connect switch for path-routing the electrical signals received from the arbitrary transmission optical receivers; a controller for controlling the path-routing of the cross-connect switch; a plurality of arbitrary transmission optical transmitters for converting the electrical signal received from each output port of the cross-connect switch to an optical signal; and, a multiplexer for multiplexing the optical signals received from the arbitrary transmission optical transmitters onto one stand of optical fiber.

Abstract: A suction valve assembly of a reciprocating compressor comprises: a valve supporting body inserted-fixed to a valve mounting portion formed at a piston and provided with at least one suction hole through which a fluid introduced into a suction passage of the piston is supplied to a compression chamber of a cylinder; and a suction valve mounted at the valve supporting body to be rotatable within a certain range, for opening and closing the suction hole formed at the valve supporting body. According to this, a damage of the suction valve due to fatigue is prevented thus to enhance a reliability of the compressor.

Abstract: A reciprocating compressor includes a closed container having a suction tube and a discharge tube, and a reference frame elastically supported and mounted in the closed container. A driving motor is mounted at one end of the reference frame for generating a linear reciprocating driving force. A front frame is coupled to the other end of the reference frame which has a cylinder insertion hole therein. A cylinder is inserted into the cylinder insertion hole, and a piston is inserted in the cylinder. A connection magnet holder penetrates the reference frame, and an engaging portion engages the connection magnet holder and the piston. A discharge valve assembly is coupled to cover a compression space formed inside the cylinder and discharging gas, and a spring surrounds and is spaced from the piston for elastically supporting a motion of the piston. The operation mechanism is stable without any driving imbalance.

Abstract: Disclosed is an opto-electrical cross connect device of high density including a shelf having a plurality of guide rails at its inner portions; a switch motherboard disposed on the rear surface of the shelf; an electric crosspoint switch positioned on the front surface of the switch motherboard; a plurality of switch connectors positioned on the front surface of the switch motherboard; an optical transceiver board mounted in the guide rail of the shelf; and, a transceiver connector disposed at the rear end of the optical transceiver board for connecting to the switch connector of the switch motherboard.

Abstract: Disclosed is a reciprocating compressor comprising a piston having a suction path connected to a compression space in the cylinder. A suction valve is mounted at an end surface of the piston for opening and closing the suction path and a discharging valve assembly is mounted at a discharge side of the cylinder for controlling gas discharge by opening and closing the compression space. An adhesion preventing unit is formed at the end surface of the piston or at a contact portion of the piston and the suction valve for minimizing adhesion between the piston and the suction valve due to oil by reducing a contact area between the piston and the suction valve.

Abstract: A reciprocating compressor includes a piston which reciprocates in a cylinder; a suction valve mounted at an end surface of the piston; a discharging valve assembly that compresses and discharges gas taken into a compression space; and a suction valve fixing member engaged to a frontal surface of the piston to movably receive the suction valve.

Abstract: A reciprocating compressor, including a piston which performs a reciprocating movement by receiving a driving force of a reciprocating motor, a cylinder in which a piston is inserted to form compression spaces therein together with the piston, and an inclined discharging surface is formed at the end surface and a valve assembly including a discharging cover which is combined with a side of the cylinder, a discharging valve which is installed at an end of the cylinder to adjust gas discharge in the compression spaces and a valve spring for elastically supporting the discharging valve.

Abstract: The present invention relates to an optical-communication system having a plurality of nodes connected by an optical-transmission line there-between, in which each of the nodes automatically recognizes the data rate of an input signal and includes a redundant channel to communicate with an adjacent node when there is a disconnection from one adjacent node.

Abstract: Disclosed are an apparatus and a method for shortening a processing time at each node in an optical network. A transmission optical cross-connect (OXC) determines a transmission rate corresponding to the transmission speed of the signal to be transmitted. An optical receiver and an optical transmitter are stabilized by means of the transmission rate. In addition, a transmission OXC transmits the transmission rate to an OXC aligned between the transmission OXC and the receiving OXC, thereby stabilizing the OXC. Each of the OXCs detects the transmission speed of the optical signal to be received so that a time required for converting the transmission speed is reduced.

Abstract: An apparatus and method for forward error correction (FEC) on a variable code length are provided.

Abstract: A bit rate-independent optical receiver ensures transparency with respect to changes of the transmission format and its associated bit rate in relation to an optical communications system. The optical receiver includes an opto-electric converter for converting an input optical signal into an electric signal, an amplifier circuit for amplifying the electrical signal, a bit rate-sensing circuit for generating a sensing signal with a voltage level determined on the basis of the bit rate of the electrical signal, a bit rate-recognition circuit for generating a recognition signal further amplified from the sensing signal, and a clock/data recovery circuit for reproducing a clock signal and data from the amplified electrical signal in accordance with a control signal.

Abstract: A reciprocating compressor includes: a closed container having a suction tube and a discharge tube; a reference frame elastically supported and mounted in the closed container; a driving motor mounted at one side of the reference frame and generating a linear reciprocating driving force; a front frame coupled to the other side of the reference frame and having a cylinder insertion hole therein; a cylinder inserted into the cylinder insertion hole formed at a central portion of the front frame; a piston inserted in the cylinder to suck, compress and discharge a refrigerant gas; a connection type magnet holder positioned penetrating the reference frame; an engaging portion engaging the connection type magnet holder and the piston; a discharge valve assembly coupled to cover a compression space formed inside the cylinder and discharging gas; a spring position at both sides of the piston and elastically supporting a motion of the piston; and a suction valve coupled at an end portion of the piston and switching a

Abstract: A circuit for monitoring the stability of light signals in an optical communications system employing WDM and having a wavelength stabilization circuit, includes: a plurality of channel transmitters each having a laser diode for generating a light signal at a particular frequency under the control of a laser diode driver; a WDM device for multiplexing the wavelengths by wavelength division; a Fabry-Perot filter having resonant frequencies continuously arranged with given free spectral ranges according to the central frequencies specified for the channels to resonate an output of the WDM device; a photodetector for converting the output light signals of the Fabry-Perot filter into corresponding electrical signals, and a quadrature phase shifter for shifting the phase of the lot output signal of the photodetector by 90°.

Abstract: This invention provides an optical transmission with a demultiplexer for demultiplexing an input optical signal into optical signals of different channels and a multiplexer for multiplexing the optical signals outputted from the demultiplexer.