摘要:
In order to compensate for chromatic dispersion caused by optical fiber transmission in a communication system with coherent detection using optical signals, specific frequency band signals are used to enable estimation of a chromatic dispersion value. The chromatic dispersion value calculating apparatus is provided with: a signal distributing circuit which distributes, into a plurality of signal sequences, an electrical digital signal converted from received optical signals of an optical signal transmitted by an optical signal transmitting apparatus, in which a known signal with concentrated frequency components of a plurality of specific frequencies is appended to a signal generated from a transmission data sequence; a plurality of frequency band pass filter circuits, each of which separating only each of a plurality of specific frequency components in which the known signal is included from each of the signal sequences distributed by the signal distributing circuit, and passing each of the specific frequency components therethrough; a plurality of power calculating circuits which are provided so as to correspond respectively to the plurality of frequency band pass filter circuits and which calculate power values of signals output from the corresponding frequency band pass filter circuits; a delay time calculating circuit which detects times at which power has the maximum value or times at which the power exceeds a predetermined threshold value, respectively from signal sequences of the power values output from the plurality of power calculating circuits, and which compares the detected times; and a chromatic dispersion value calculating circuit which calculates a chromatic dispersion value based on a comparison result of the times by the delay time calculating circuit.
摘要:
A butt welding apparatus and a butt welding method where end faces of at least one plate member to be welded are butted to each other to form a butt portion, and butt welding can be performed on respective plate members which have various thickness sizes on both side portions of the butt portion with electric resistance heat by a pair of electrode members which are common to the respective plate members. At least one electrode member (1) is provided on an outer face thereof with a convex portion (1A) which gradually retreats from one plate member (31) of two plate members (31, 32) as it extends from an intermediate portion, in a thickness direction, of the one electrode member (1) along the one plate member (31). Butt welding of the two plate members (31, 32) is performed by the position of the butting portion (71) of these plate members (31, 32) being offset from the intermediate portions, in the thickness directions, of the electrode members (1, 2) to the convex portion (1A) by an amount (L1) corresponding to a difference in thickness between the plate members (31, 32).
摘要:
A method and an apparatus for machining a mold material to produce a mold. By casting based on a cast mold model (15), a mold material (20) is produced in a form having a work margin. Thereafter, a shape of the mold material (20) is measured by a measuring device (16), and measurement data and an envelope model (M2) generated based on the measurement data are stored in a storage unit (12A) of a computer (12). Thereafter, a mold model (M1) based on mold design data and an envelope model (M2) are displayed on a display unit (12C), and the envelope model (M2) is linearly moved in direction of three axes X, Y and Z orthogonal to one another respectively and rotated around the three axes to bring a product forming plane (M2B) of the envelope model (M2) into close proximity of a product forming plane (M1B) of the mold model (M1). Thereby, a state in which a work amount of a product forming plane (20B) of the mold material (20) is reduced is found, and a reference plane (20A) and a product forming plane (20B) of the mold material 20 are cut by a mold working machine (18) controlled by the computer (12).
摘要:
A wire harness is made up of a plurality of partial harnesses. Each of the partial harnesses is arranged such that opposite end portions of a plurality of electric wires having terminals at ends thereof are retained in advance in U-shapes with predetermined intervals provided so as to correspond to a plurality of connectors into which the terminals are inserted, by a plurality of wire clamps juxtaposed at equal pitches on a wire clamping bar. The terminals at the ends of the plurality of electric wires in each of the partial harnesses are inserted into terminal accommodating chambers of predetermined connectors selected from the plurality of connectors, thereby aggregating the partial harnesses into a combined unit.
摘要:
Disclosed are a butt welding apparatus, a butt welding method, and a product manufactured by the butt welding method. Two electrode rollers (3, 4) are disposed on both the front and back sides of a thick sheet member (1) and on both the front and back sides of a thin sheet member (2) whose end surfaces (1A, 2A) are butted. The electrode rollers (3, 4) are applied with power, melt the butt portion (6) of the sheet members (1, 2) with electric resistance heat, and joint the butt portion. Further, the electrode rollers (3, 4) have a length bridging across the sheet members (1, 2) and are composed of first portions (3A, 4A) arranged as small diameter portions on the side of the thick sheet member (1) and second portions (3B, 4B) arranged as large diameter portions on the side of the thin sheet member (2). The first portions (3A, 4A) come into contact with the thick sheet member (1) and presses it before the second portions (3B, 4B) come into contact with the thin sheet member (2). Thus, the end surface (1A) of the thick sheet member (1) swells and deforms toward the thin sheet member (2) and reliably comes into contact with the end surface (2A) of the thin sheet member (2). As a result, power is applied between the end surfaces (1A, 2A) even if the end surfaces (1A, 2A) are not finished by polishing and the like.
摘要:
A vehicle door which can be used as a tailgate or a side door of a vehicle and a manufacturing method of this vehicle door is provided. A tailgate (1) which is a vehicle door is formed of an outer panel (2) on an outer side of a vehicle, an inner panel (3) on an inner side of the vehicle, and a module plate (4) to which door parts such as a wiper motor (18) are attached, and a lining (6). The inner panel (3) is in a frame shape with only a marginal portion (10) of the whole periphery left and with an opening (11) formed therein, which results in reduction in the weight of the tailgate (1). The module plate (4) which also serves as a reinforcing member is composed of a first extending portion (13) extending in a right and left direction and a second extending portion (14) extending downward from the first extending portion (13) to be in a substantially T-shape, which also results in reduction in the weight of the module plate (4), and connection of the module plate (4) to the outer panel (2) and the inner panel (3) reinforces the tailgate (1).
摘要:
An optical modulation device including: bias power supplies that output a signal having a bias voltage corresponding to the null point of an optical modulation unit to the optical modulation unit; and synchronous detection circuits that determine whether an intensity of a QAM signal at a drift non-occurrence time where no drift occurs in the bias voltage becomes larger or smaller than the intensity of the QAM signal at a drift occurrence time where a drift occurs in the bias voltage, adjust the bias voltage to maximize the intensity of the QAM signal when determining that the intensity of the QAM signal at the drift non-occurrence time becomes larger than the intensity of the QAM signal at the drift occurrence time, and adjust the bias voltage to minimize the intensity of the QAM signal when determining that the intensity of the QAM signal at the drift non-occurrence time becomes smaller than the intensity of the QAM signal at the drift occurrence time.
摘要:
A parameter of an adaptive filter is optimized so that inter-symbol interference having an amount corresponding to an inserted fixed filter remains. A digital signal processing apparatus which is included in an optical signal receiver and processes a digital signal converted from an optical signal is provided with: a linear adaptive filter which applies a dynamically controllable linear transfer function to the digital signal; a maximum likelihood sequence decoder which applies a transfer function of a transmission-path model to a plurality of signal sequence candidates to generate a plurality of reference signals, and decodes a reception signal using maximum likelihood sequence estimation which evaluates the differences between an output signal of the linear adaptive filter and the reference signals to estimate the most likely transmission time sequence; a signal regenerator which generates a signal corresponding to decoded data from the maximum likelihood sequence decoder; a feedback distortion adding filter which adds distortion that is equivalent to the transmission-path model used in the maximum likelihood sequence decoder to an output signal of the signal regenerator; and an adaptive equalization filter control block which updates a tap coefficient of the linear adaptive filter in accordance with an LMS algorithm using the difference between a target signal that is an output signal of the feedback distortion adding filter and the digital signal as an error signal.
摘要:
Provided is a frequency offset estimation apparatus that appropriately estimates and compensates for a frequency offset of a received signal when estimating the frequency offset which is the difference between a carrier frequency of the received signal and the frequency of an output signal of a local oscillator. The frequency offset estimation apparatus converts the received signal sampled in advance with a predetermined sampling frequency into a frequency spectrum having N frequency components, limits a frequency band of negative frequency components from 1 to N/2 of the frequency spectrum and a frequency band of positive frequency components from N/2+1 to N of the frequency spectrum, calculates the sum of the squares of the positive frequency components of the frequency spectrum that have been subjected to frequency band limitation and the sum of the squares of the negative frequency components of the frequency spectrum that have been subjected to frequency band limitation to calculate power of the positive frequency components and power of the negative frequency components, and cyclically shifts all frequency components of the frequency spectrum in a frequency domain until the absolute value of a power difference between the power of the positive frequency components and the power of the negative frequency components is less than or equal to a predetermined threshold value, and estimates the frequency offset based on a shift amount until the absolute value is less than or equal to the threshold value.
摘要:
An optical digital transmission system of the present invention newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required.