Disclosed herein is a signal receiving apparatus including a profile inference section; a delay-spread computation section; a position determination section; a signal-by-function multiplication section; an interval extraction section; an interval-to-signal addition section; and a signal processing section.

1. Field of the Invention
In general, the present invention relates to a signal receiving apparatus, a signal receiving method adopted by the signal receiving apparatus and a program implementing the signal receiving method. In particular, the embodiments of the present invention relates to a signal receiving apparatus capable of easily carrying out an OFDM (Orthogonal Frequency Division Multiplexing) demodulation process making use of a window function without causing an ISI (Inter Symbol Interference) even in a multipath environment, relates to a signal receiving method adopted by the signal receiving apparatus and relates to a program implementing the signal receiving method.
2. Description of the Related Art
As a method for modulating a ground digital broadcast, there has been proposed an OFDM (Orthogonal Frequency Division Multiplexing) method for modulating a number of various orthogonal carrier waves by adoption a PSK (Phase Shift Keying) technique and/or a QAM (Quadrature Amplitude Modulation) technique (Japanese Patent Laid-Open No. 2005-303440).
The OFDM method is defined in that, since the entire transmission band is divided into a number of transmission sub-bands each allocated to a sub-carrier wave, the width of the transmission sub-band is small, giving rise to a low transmission speed even though the total transmission speed does not change from the speed according to the existing modulation method.
In addition, the OFDM method is also defined in that, since a number of sub-carrier waves are transmitted, the symbol speed is low. Thus, the multipath time length relative to the time length of one symbol can be reduced. As a result, the OFDM method also has a characteristic that a transmission according to the OFDM method is hardly affected by the multipath.
On top of that, the OFDM method is also defined in that, since data is assigned to a plurality of sub-carrier waves, a signal transmitting circuit can be constructed by making use of an IFFT (Inverse Fast Fourier Transform) processing circuit for carrying out an inverse Fourier transform operation at a modulation time whereas a signal receiving circuit can be constructed by making use of an FFT (Fast Fourier Transform) processing circuit for carrying out a Fourier transform operation at a demodulation time.
FIG. 1 is a diagram showing a sequence of OFDM symbols.
In accordance with the OFDM method, a signal is transmitted in units each referred to as an OFDM symbol.
As shown in the diagram of FIG. 1, one OFDM symbol includes an effective symbol and a guard interval referred to hereafter simply as a GI. The effective symbol is a signal segment on which an IFFT operation is carried out at a transmission time. On the other hand, the GI is a copy of the waveform of a later portion of the effective symbol. The GI is inserted into a position existing on the time axis as a position in the front of the effective symbol.
By inserting such a GI in accordance with the OFDM method, the OFDM method is capable of preventing an ISI (Inter Symbol Interference, which is an interference between symbols) from occurring in a multipath environment.
A plurality of such OFDM symbols are collected to form an OFDM-transmitted frame. For example, in accordance with ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) specifications, 204 OFDM symbols form an OFDM-transmitted frame. The ISDB-T specifications are specifications prescribing ground digital broadcasts transmitted in Japan.
In accordance with the OFDM method, by using an OSDM-transmitted frame unit as a reference, each of a data carrier wave, an SP (Spread Pilot) signal and a TMCC carrier wave is used as a sub-carrier wave as shown in a diagram of FIG. 2. The data carrier wave is a carrier wave for transmitting data. The SP signal is a signal used for inferring a transmission characteristic (or a frequency characteristic) on the OFDM receiver side. The TMCC carrier wave is a carrier wave for transmitting transmission parameters.
Placed at fixed intervals, the SP signals are each a complex vector having a known amplitude and a known phase. The data sub-carrier wave conveying data to be transmitted is placed between SP signals. An OFDM receiver receives an SP signal in a state distorted due to an effect of the characteristic of the transmission line. Since the state of the SP signal at a signal transmitting time is known, however, the characteristic of the transmission line can be inferred by comparing the state of the SP signal at a signal transmitting time with the state of the SP signal at a signal receiving time.
FIG. 3 is a block diagram showing a typical configuration of the existing OFDM receiver.
As shown in the block diagram of FIG. 3, the existing OFDM receiver employs an antenna 1, a frequency conversion circuit 2, a local oscillation circuit 3, an A/D (Analog/Digital) conversion circuit 4, a orthogonal-demodulation circuit 5, a local oscillation circuit 6, an FFT circuit 7, an SP-signal extraction circuit 8, a time-direction transmission-line characteristic inference circuit 9, a frequency-direction transmission-line characteristic inference circuit 10, a transmission-line compensation circuit 11, a carrier-frequency synchronization circuit 12, a window reproduction circuit 13 and a delay-profile inference circuit 14.
The frequency conversion circuit 2 is a section for multiplying an RF signal received from the antenna 1 by a carrier wave received from the local oscillation circuit 3 as a carrier wave with an oscillation frequency of (fc+fIF) in order to convert the RF signal into an IF signal having a center frequency fIF and for outputting the IF signal obtained as a result of the frequency conversion process to the A/D conversion circuit 4.
The A/D conversion circuit 4 is a section for carrying out an A/D conversion process of converting the analog IF signal received from the frequency conversion circuit 2 into a digital IF signal and outputting the digital IF signal obtained as a result of the A/D conversion process to the orthogonal-demodulation circuit 5.
The orthogonal-demodulation circuit 5 is a section for carrying out an orthogonal demodulation process making use of a carrier wave received from the local oscillation circuit 6 as a carrier wave having the frequency fIF in order to acquire a baseband OFDM signal from the digital IF signal supplied by the A/D conversion circuit 4. The baseband OFDM signal is the so-called time-domain OFDM signal not subjected yet to an FFT process. The orthogonal-demodulation circuit 5 outputs the time-domain OFDM signal obtained as a result of the orthogonal demodulation process to the carrier-frequency synchronization circuit 12, the FFT circuit 7 and the window reproduction circuit 13.
The FFT circuit 7 is a section for removing a GI from the time-domain OFDM signal on the basis of an FFT window position specified by the window reproduction circuit 13 in order to extract a signal in a range including an effective symbol associated included in the same OFDM symbol as the removed GI from the time-domain OFDM signal.
The FFT circuit 7 is also a section for carrying out an FFT process on the extracted signal as a demodulation process in order to generate a post-demodulation OFDM signal and outputting the generated post-demodulation OFDM signal to the SP-signal extraction circuit 8 and the transmission-line compensation circuit 11. The post-demodulation OFDM signal generated by the FFT circuit 7 is the so-called frequency-domain OFDM signal which is obtained as a result of the FFT process.
The start position of the FFT process carried out by the FFT circuit 7 is a position between positions A and B shown in the diagram of FIG. 1. The position A is a position on a boundary between two adjacent OFDM symbols whereas the position B is a position on a boundary between an effective symbol included in the later one of the two adjacent OFDM symbols and a GI included in the same later OFDM symbol as the effective symbol. The range of the FFT process is referred to as an FFT window. Referred to hereafter as an FFT window position cited above, the start position of the FFT window is specified by the window reproduction circuit 13.
The SP-signal extraction circuit 8 is a section for extracting an SP signal from the frequency-domain OFDM signal received from the FFT circuit 7 and removing modulation components from the extracted SP signal in order to infer a transmission-line characteristic prevailing at the position of an OFDM symbol associated with the SP signal as a transmission-line characteristic of a sub-carrier wave. The SP-signal extraction circuit 8 outputs a signal representing the transmission-line characteristic of the sub-carrier wave to the time-direction transmission-line characteristic inference circuit 9.
The time-direction transmission-line characteristic inference circuit 9 is a section for inferring transmission-line characteristics prevailing at positions of other OFDM symbols lined up in the time-axis direction (which is also referred to as an OFDM-symbol direction) in an area between the positions of specific OFDM symbols each associated with an SP signal as transmission-line characteristics of a sub-carrier wave on the basis of the transmission-line characteristics inferred by the SP-signal extraction circuit 8 as the transmission-line characteristics which prevail at the positions of the specific OFDM symbols as the transmission-line characteristics of the sub-carrier wave. In the diagram of FIG. 2, the vertical direction is the time-axis direction whereas the horizontal direction is a frequency direction.
Let us assume for example that the SP-signal extraction circuit 8 infers transmission-line characteristics prevailing at the positions of specific OFDM symbols associated with SP signals SP1 and SP2 shown in the diagram of FIG. 2 as transmission-line characteristics of a sub-carrier wave having a sub-carrier number of 0. In this case, the time-direction transmission-line characteristic inference circuit 9 infers transmission-line characteristics prevailing at the positions of other OFDM symbols in an area A1 sandwiched between the positions of the specific OFDM symbols as shown in the diagram of FIG. 2 as transmission-line characteristics of the sub-carrier wave by making use of transmission-line characteristics inferred by the SP-signal extraction circuit 8.
As shown in the diagram of FIG. 2, since a plurality of SP signals are inserted for every 3 sub-carrier waves, the time-direction transmission-line characteristic inference circuit 9 infers transmission-line characteristics prevailing at positions of other OFDM symbols lined up in the time-axis direction (which is also referred to as an OFDM-symbol direction) in an area between the positions of specific OFDM symbols each associated with one of the inserted SP signals as transmission-line characteristics of a sub-carrier wave. For every 3 sub-carrier waves, the time-direction transmission-line characteristic inference circuit 9 outputs a signal representing transmission-line characteristics inferred thereby as the transmission-line characteristics of the three sub-carrier waves to the frequency-direction transmission-line characteristic inference circuit 10 and the delay-profile inference circuit 14. The transmission-line characteristics represented by the signal output by the time-direction transmission-line characteristic inference circuit 9 include the transmission-line characteristics inferred by the SP-signal extraction circuit 8.
The frequency-direction transmission-line characteristic inference circuit 10 is a section for inferring transmission-line characteristics prevailing at positions of OFDM symbols lined up in the frequency direction (which is also referred to as a sub-carrier direction) as transmission-line characteristics of sub-carrier waves on the basis of transmission-line characteristics output by the time-direction transmission-line characteristic inference circuit 9.
For example, the frequency-direction transmission-line characteristic inference circuit 10 infers transmission-line characteristics prevailing at positions of an OFDM symbol included in an area A2 shown in the diagram of FIG. 2 as OFDM symbol #3 conveyed at the same time by sub-carrier waves having different sub-carrier numbers as shown in the diagram of FIG. 2 as transmission-line characteristics of the sub-carrier waves. However, the frequency-direction transmission-line characteristic inference circuit 10 infers merely transmission-line characteristics which have not been inferred yet by the SP-signal extraction circuit 8 and the time-direction transmission-line characteristic inference circuit 9. Thus, the frequency-direction transmission-line characteristic inference circuit 10 infers transmission-line characteristics by making use of transmission-line characteristics inferred by the SP-signal extraction circuit 8 and the time-direction transmission-line characteristic inference circuit 9.
As a result, the transmission-line characteristics prevailing at the positions of all OFDM symbols as transmission-line characteristics of sub-carrier waves are inferred. The frequency-direction transmission-line characteristic inference circuit 10 outputs a signal representing the inferred transmission-line characteristics to the transmission-line compensation circuit 11.
The transmission-line compensation circuit 11 is a section for removing distortion components, which are included in the frequency-domain OFDM signal received from the FFT circuit 7 as components attributed to distortions occurring along the transmission line, by making use of transmission-line characteristics represented by a signal output by the frequency-direction transmission-line characteristic inference circuit 10. The transmission-line compensation circuit 11 outputs a frequency-domain OFDM signal including no distortion components to circuits at a stage succeeding this OFDM receiver as an equalizer output signal.
The carrier-frequency synchronization circuit 12 is a section for controlling the local oscillation circuit 6 on the basis of the time-domain OFDM signal received from the orthogonal-demodulation circuit 5 in order to drive the local oscillation circuit 6 to output a carrier wave having an oscillation frequency fIF synchronized with the frequency of the IF signal generated by the frequency conversion circuit 2 to the orthogonal-demodulation circuit 5.
The window reproduction circuit 13 is a section for determining an FFT window position on the basis of the time-domain OFDM signal received from the orthogonal-demodulation circuit 5 and a delay-profile signal received from the delay-profile inference circuit 14 and outputting the determined FFT window position to the FFT circuit 7.
The delay-profile inference circuit 14 is a section for inferring a delay profile of the transmission line by finding a time response characteristic of the transmission line and outputting a signal representing the inferred delay profile to the window reproduction circuit 13.
Typically, the delay-profile inference circuit 14 carries out an IFFT process on transmission-line characteristics represented by a signal output by the time-direction transmission-line characteristic inference circuit 9 in order to infer the delay profile of the transmission line. Since the transmission-line characteristic represented by a signal output by the time-direction transmission-line characteristic inference circuit 9 is a frequency characteristic, a time response characteristic obtained as a result of the IFFT process carried out on the transmission-line characteristic is a delay profile.
FIG. 4 is a block diagram showing a typical configuration of the FFT circuit 7 employed in the existing OFDM receiver shown in the block diagram of FIG. 3.
As shown in the block diagram of FIG. 4, the FFT circuit 7 employs a GI removal circuit 7-1 and an FFT processing circuit 7-2.
The GI removal circuit 7-1 is a section for removing a GI included in a time-domain OFDM signal received from the orthogonal-demodulation circuit 5 on the basis of an FFT window position received from the window reproduction circuit 13. The GI removal circuit 7-1 outputs an effective symbol obtained as a result of the process to remove a GI included in a time-domain OFDM signal to the FFT processing circuit 7-2.
The FFT processing circuit 7-2 is a section for carrying an FFT process on an effective symbol received from the GI removal circuit 7-1 in order to transform a time-domain OFDM signal including the effective symbol into a frequency-domain OFDM signal. The FFT processing circuit 7-2 outputs the frequency-domain OFDM signal obtained as a result of the FFT process to the SP-signal extraction circuit 8 and the transmission-line compensation circuit 11.
The FFT window position which is the start of the FFT process mentioned above is explained by referring to diagrams of FIGS. 5 and 6 as follows.
FIG. 5 is a diagram showing a typical FFT window position in a 1-wave environment whereas FIG. 6 is a diagram showing a typical FFT window position in a multipath environment.
In the 1-wave environment, an OFDM signal consisting of merely a principal wave as shown in the diagram of FIG. 5 is received by the OFDM receiver. In this diagram, notation Tu denotes the length of an effective wave represented by the OFDM signal whereas notation Tg denotes the length of a GI included in the same OFDM signal as the effective wave.
The FFT window position is a position between positions C and D shown in the diagram of FIG. 5. The position C is a position on a boundary between two adjacent OFDM symbols whereas the position D is a position on a boundary between an effective symbol of the later one of the two adjacent OFDM symbols and a GI included in the same later OFDM symbol as the effective symbol. In the case of the typical 1-wave environment shown in the diagram of FIG. 5, the FFT window position is specified to be the position D. As described above, the GI removal circuit 7-1 removes a GI included in a time-domain OFDM signal received from the orthogonal-demodulation circuit 5 on the basis of an FFT window position received from the window reproduction circuit 13. A range starting from the FFT window position as a range consisting of N FFT points is used as an FFT window. Notation N also denotes the number of samples in the effective symbol.
In the multipath environment, on the other hand, an OFDM signal consisting of the principal wave and a delayed wave as shown in the diagram of FIG. 6 is received by the OFDM receiver. For the sake of the convenience of the explanation, a multipath environment of two waves, i.e., the principal wave and a delayed wave, is explained.
In the case of the typical multipath environment shown in the diagram of FIG. 6, the OFDM receiver receives a compound wave consisting of the principal wave, which serves as a direct wave, and a delayed wave. The delayed wave is a wave which is delayed from the principal wave by a delay time τ and has an attenuated amplitude. As shown in the diagram of FIG. 6, the width of a band representing the principal wave is made greater than the width of a band representing the delayed wave in order to indicate that the amplitude of the principal wave is greater than the amplitude of the delayed wave.
In the case of the typical multipath environment shown in the diagram of FIG. 6, in order to prevent an ISI (Inter-Symbol Interference) from occurring after a demodulation process, the FFT window position is set at a position between positions E and F shown in the diagram of FIG. 6. The position E is the start position of an OFDM symbol represented in the delayed wave. There is no interference in this OFDM symbol from an OFDM symbol immediately preceding this OFDM symbol. On the other hand, the position F is a position on a boundary between an effective symbol represented by the principal wave and a GI included in the same OFDM symbol as the effective symbol in the principal wave. Thus, in the case of a typical multipath environment, the range in which the FFT window position can be specified is narrow in comparison with the range in a 1-wave environment.
In the case of the typical multipath environment shown in the diagram of FIG. 6, the FFT window position is specified to be the position F which is a position on a boundary between an effective symbol represented by the principal wave and a GI included in the same OFDM symbol as the effective symbol in the principal wave.
An OFDM demodulation process making use of an FFT window is carried out as follows.
Muschallik C., 'Improving an OFDM reception using an adaptive Nyquist windowing', Consumer Electronics, IEEE Transactions, Volume 42, Issue 3, August 1996, Pages 259-269 discloses an OFDM demodulation process making use of a window function.
FIG. 7 is a block diagram showing a typical configuration of an FFT circuit 7 for carrying out an OFDM demodulation process making use of a window function.
As shown in the block diagram of FIG. 7, the FFT circuit 7 employs a window-function utilization circuit 7-11, a 0 addition circuit 7-12, a 2N-point FFT processing circuit 7-13 and an even-numbered carrier extraction circuit 7-14. In the same way of the FFT circuit 7 shown in the block diagram of FIG. 4, the FFT circuit 7 having a configuration like the one shown in the block diagram of FIG. 7 receives a time-domain OFDM signal from the orthogonal-demodulation circuit 5.
The window-function utilization circuit 7-11 is a section for setting a window function for a time-domain OFDM signal received from the orthogonal-demodulation circuit 5 on the basis of an FFT window position specified by the window reproduction circuit 13 and multiplying the time-domain OFDM signal by the window function in order to produce a weighted time-domain OFDM signal. The window-function utilization circuit 7-11 outputs the weighted time-domain OFDM signal obtained as a result of the operation to multiply the time-domain OFDM signal received from the orthogonal-demodulation circuit 5 by the window function to the 0 addition circuit 7-12. In the following description, the weighted time-domain OFDM signal is also referred to as a post-multiplication time-domain OFDM signal.
In order to allow an FFT process to be carried out on a time-domain OFDM signal having a format also including a GI, as shown in a diagram of FIG. 10C, the 0 addition circuit 7-12 adds 0 values, the number of which is determined in advance, to the tail of the weighted time-domain OFDM signal received from the window-function utilization circuit 7-11 and converts the weighted time-domain OFDM signal having 0s added thereto into a signal including 2N samples where notation N denotes the number of samples in an effective symbol. The 0 addition circuit 7-12 outputs the time-domain OFDM signal including the 2N samples to the 2N-point FFT processing circuit 7-13.
The 2N-point FFT processing circuit 7-13 is a section for carrying out a 2N-point FFT process on the 2N samples included in the time-domain OFDM signal having a GI in order to transform the time-domain OFDM signal including 2N samples into a frequency-domain OFDM signal. The 2N-point FFT processing circuit 7-13 outputs the frequency-domain OFDM signal obtained as a result of the FFT process to the even-numbered carrier extraction circuit 7-14.
The even-numbered carrier extraction circuit 7-14 is a section for extracting the signal of an even-numbered carrier wave from the frequency-domain OFDM signal supplied by the 2N-point FFT processing circuit 7-13 and outputting the extracted signal as a frequency-domain OFDM signal to the SP-signal extraction circuit 8 and the transmission-line compensation circuit 11.
FIG. 8 is a plurality of diagrams showing a time-domain OFDM signal and typical window functions.
To be more specific, FIG. 8A is a diagram showing a time-domain OFDM signal representing one OFDM symbol. FIG. 8B is a diagram showing a trapezoidal window function whereas FIG. 8C is a diagram showing a protruding window function. FIG. 8D is a diagram showing a raised cosine window function. In the diagrams of FIG. 8, the horizontal axis represents the lapse of time whereas the vertical axis represents the amplitude of time-domain OFDM signal and the values of the window functions. Each of the values of the window functions is used as a multiplier by which the amplitude of the time-domain OFDM signal is to be multiplied.
A time segment S1 in the diagrams of FIG. 8 is a time segment corresponding to the time segment of the GI whereas a time segment S2 is a time segment starting from the boundary between the GI and the effective symbol and ending at a position leading ahead of the end of the effective symbol by the length Tg of the GI. A time segment S3 is a time segment between the position leading ahead of the end of the effective symbol by the length Tg of the GI and the end of the effective symbol.
As shown in the diagrams of FIG. 8, each of the window functions has a fixed window width of (Tu+Tg) and a predetermined value varying in the range 0 to 1 as a function of time.
With the start position of each window function coinciding with the start position of an OFDM symbol, the trapezoidal window function shown in the diagram of FIG. 8B has a value rising from 0 to 1 along a straight line over the time segment S1 and the fixed value of 1 throughout the time segment S2. The trapezoidal window function has a value decreasing from 1 to 0 along a straight line over the time segment S3.
The protruding window function shown in the diagram of FIG. 8C has a fixed value of 0.5 throughout the time segment S1 and a fixed value of 1 throughout the time segment S2. The protruding window function has the fixed value of 0.5 throughout the time segment S3.
The raised cosine window function shown in the diagram of FIG. 8D has a value rising from 0 to 1 along a curved line over the time segment S1 and the fixed value of 1 throughout the time segment S2. The raised cosine window function has a value decreasing from 1 to 0 along a curved line over the time segment S3.
A window function is defined in that, if the time segment S3 of the window function itself overlaps the time segment S1 of the window function shifted by a distance corresponding to the length Tu of the effective symbol in the time lapsing direction along the time axis as shown in a diagram of FIG. 9, the sum of the values of the window function itself and the shifted window function in the overlapping time segments S1 and S3 each having the GI length Tg is equal to 1 throughout the overlapping time segments S1 and S3.
For example, a trapezoidal window function W′ shown in the diagram of FIG. 9 is a window function obtained as a result of shifting a trapezoidal window function W by a distance corresponding to the length Tu of the effective symbol in the time lapsing direction along the time axis. Times t1 and t2 are any arbitrary points of time in the overlapping time segment S3 of the trapezoidal window function W and the overlapping time segment S1 of the trapezoidal window function W′. At each of the times t1 and t2, the sum of the values of the trapezoidal window functions W and W′ is equal to 1.
FIG. 10 is a plurality of explanatory diagrams each referred to in description of an OFDM demodulation process carried out by making use of the trapezoidal window function shown in the diagram of FIG. 8.
To be more specific, FIG. 10A is a diagram showing a time-domain OFDM signal representing one OFDM symbol whereas FIG. 10B is a diagram showing the trapezoidal window function. FIG. 10C is a diagram showing a time-domain OFDM signal supplied to the 2N-point FFT processing circuit 7-13 employed in the FFT circuit shown in the block diagram of FIG. 7.
The window-function utilization circuit 7-11 sets the trapezoidal window function shown in the diagram of FIG. 10B. As shown in this diagram, a position G is the start position of the time segment S2 of the trapezoidal window function. As described earlier, the trapezoidal window function has a fixed value of 1 throughout the time segment S2. The window-function utilization circuit 7-11 sets a trapezoidal window function that has a start position G coinciding with an FFT window position, which is specified by the window reproduction circuit 13, on the time axis. Then, the window-function utilization circuit 7-11 multiplies the time-domain OFDM signal shown in the diagram of FIG. 10A by the trapezoidal window function shown in the diagram of FIG. 10B in order to produce a weighted time-domain OFDM signal shown in the diagram of FIG. 10C.
In an OFDM receiver carrying out an OFDM demodulation process by making use of a window function, the position on the boundary between the GI and the effective symbol is an optimum FFT window position. In the typical OFDM demodulation process explained by referring to the diagrams of FIG. 10, the window reproduction circuit 13 specifies the optimum position as an FFT window position.
As described above, in this typical OFDM demodulation process, the window-function utilization circuit 7-11 multiplies the time-domain OFDM signal shown in the diagram of FIG. 10A by the trapezoidal window function shown in the diagram of FIG. 10B in order to produce a weighted time-domain OFDM signal having the same trapezoidal shape as the trapezoidal window function as shown in the diagram of FIG. 10C and supplies the weighted time-domain OFDM signal to the 0 addition circuit 7-12.
The 0 addition circuit 7-12 adds 0 values, the number of which is determined in advance, to the tail of the weighted time-domain OFDM signal received from the window-function utilization circuit 7-11 and converts the weighted time-domain OFDM signal into a signal including 2N samples as shown in the diagram of FIG. 10C where notation N denotes the number of samples in the effective symbol. The 0 addition circuit 7-12 then outputs the time-domain OFDM signal including the 2N samples to the 2N-point FFT processing circuit 7-13. The 2N-point FFT processing circuit 7-13 carries out a 2N-point FFT process on the 2N samples included in the time-domain OFDM signal having a GI in order to transform the time-domain OFDM signal including the 2N samples into a frequency-domain OFDM signal.
By making use of a GI, which is a copy of a later portion of an effective symbol included in the same OFDM symbol as the GI, in a demodulation process as described above, it is possible to provide the OFDM receiver with a characteristic of resistance against noises.

Signal receiving apparatus, signal receiving method and program


The present invention is a cross-connect protection method that protects a cross-connect in a system where a plurality of network management terminals monitor a plurality of network elements constituting a network and the cross-connect at each of the network elements is controlled. An arbitrary one of the network management terminals instructs locking and unlocking of a cross-connect set in an arbitrary one of the network elements. The arbitrary network element controls the instructed locking and unlocking of the set cross-connect. Hence, when conducting a test, after locking a cross-connect set in an actual operation, a cross-connect of a testing network element is set/canceled for the test. Accordingly, it is possible to avoid erroneous cutting off of a signal used in the actual operation.

Conventionally, a terminal (hereinafter referred to as a "network management terminal") of a network management system (NMS) is connected to a network constituted by a plurality of network elements (NE), so as to control and manage cross-connects.
FIG. 1 is a system block diagram for explaining the NMS. In FIG. 1, a plurality of network elements 10a through 10e, such as switching equipments and network elements, are connected to constitute a network 12 such as a telecommunication network. Each of the network elements 10a through 10e is connected to a data communication network 14 such as a telecommunication management network (TMN). Network management terminals 16a through 16c and a maintenance terminal (workstation) 18 which is used as a kind of the network management terminal are connected to the data communication network 14.
FIG. 2 is a system block diagram of an example of a network including the NMS. In FIG. 2, the network has a structure such that high-speed network elements 20a through 20d having a transmission rate of 2.5 Gbps, for example, are connected in a ring by optical fiber transmission channels 21a through 21d. In addition, a medium-speed optical network element 20f having a transmission rate of 600 Mbps is connected to the network element 20b via an optical fiber transmission channel 21e, and a low-speed optical network element 20g having a transmission rate of 150 Mbps is connected to the network element 20c via an optical fiber transmission channel 21f. The transmission rate of 2.5 Gbps has a capacity to pass sixteen VC4 (Virtual Container 4) signals at 140 Mbps according to the ITU-T recommendations. The transmission rate of 600 Mbps can pass four VC4 signals, and the transmission rate of 150 Mbps can pass one VC4 signal. Accordingly, each of the network elements 20a through 20d sets a cross-connect so as to form a path for the VC4 signal.
For example, the network element 20a is provided in Osaka, and the network element 20c is provided in Tokyo. A maintenance terminal 22 and a network management terminal (NMS#1) 24 are connected to the network element 20a in Osaka. A network management terminal (NMS#2) 26 is connected to the network element 20c in Tokyo. Further, a network management terminal (NMS#3) 28 is connected to the network management terminal 26. In this case, the network management terminal 28 performs an operation by referring to a database of the network management terminal 26. In addition, as shown in FIG. 30, for example, in a network where the network elements 20a through 20d are connected in a ring, network elements 20g through 20j are connected in a ring, and the network elements 20c and 20g are connected, when network management apparatuses 24 and 25 are connected to the network elements 20b and 20i, respectively, and a network management terminal 27 is connected to the network management terminals 24 and 25, the network management terminal 27 centrally manages information (alarm information and cross-connect information) of the network management terminals 24 and 25, and issues an instruction to the network management terminals 24 and 25 so as to transmit commands.
In FIG. 2, the maintenance terminal 22 can be connected to a network element the maintenance terminal 22 intends to perform maintenance, and can set a cross-connect only with respect to this network element. On the other hand, the network management terminals 24, 26 and 28 can form a path from an arbitrary point in a network to another arbitrary point in the network via a plurality of network elements which are not limited to the network elements connected to the network management terminals 24, 26 and 28. For example, the network management terminals 24, 26 and 28 can form a path for the VC4 signal via the four network elements 20f, 20b, 20c and 20g. In this case, the network management terminals 24, 26 and 28 set cross-connects at each of the network elements 20f, 20b, 20c and 20g.
Conventionally, it is possible to set/cancel a cross-connect of an arbitrary network element from any network management terminal or maintenance terminal, as long as an NE user ID which is input to the network management terminal or maintenance terminal when operating a network element is equal to or higher than a predetermined security level, and at the same time, an NMS user ID has an authority to operate a cross-connect function.
For this reason, in a case where tests such as an operation check and a communication error check of a network element are conducted in parallel with an actual operation, there is a problem in that a signal used in the actual operation is erroneously cut off when a cross-connect of a testing network element is set/canceled from an arbitrary network management terminal.

Cross-connect protection method, network management terminal, and network element


A refrigerator includes a main body, a storage space defined within the main body, a door configured to open and close at least a portion of the storage space, a dispenser provided in the door and defining a space in which water is dispensed, a water nozzle extending downward into the space, where the water nozzle is movably mounted at the dispenser and configured to dispense water, a manipulation detection device provided at the dispenser, the manipulation detection device being configured to detect movement of the water nozzle, and a control unit configured to open and close a water supply valve connected to the water nozzle according to a detection signal generated by the manipulation detection device.

In general, refrigerators are home appliances for storing foods at a low temperature in a storage space that is covered by a door. For this, refrigerators cool the inside of the storage space by using cool air generated by being heat-exchanged with a refrigerant circulated into a refrigeration cycle to store foods in an optimum state.
In recent years, refrigerators having various convenience equipment have been brought to the market. A dispenser for dispensing water or ice from the outside in a state where a refrigerator is closed is one representative example of such convenience equipment.
In general, such dispenser is provided in a front surface of a refrigerator door to dispense water or ice by manipulating a lever. For this, the dispenser can include a water nozzle for dispensing water. The lever can be disposed under the water nozzle. Thus, the lever can be manipulated to dispense water.


The invention is a collapsible structure comprising a plurality of panel elements, each having a coilable frame element and flexible material attached to the frame element. The panel elements are joined to define an enclosure having a roof portion and a bottom perimeter. The bottom perimeter rests on a supporting surface. The structure has at least one roof support rod having a first end and a second end. The first end of the at least one roof support rod is attached to a first location on the bottom perimeter, and the second end of the at least one roof support rod is attached to a second location on the bottom perimeter. The at least one roof support rod is in supporting contact with the roof portion of the enclosure.

Portable enclosures, such as tents, have been used as blinds and shelters since the beginning of recorded time. The structure and appearance of such enclosures is as varied as human culture.
More recently, portable, lightweight, durable, and affordable enclosures have become a desirable accessory for many outdoor recreational activities, including camping and hunting. The widespread availability of modern lightweight structures and fabrics has resulted in the proliferation of literally hundreds of new designs for portable enclosures. Among the many popular current styles for tents and hunting blinds are the so-called "collapsible" structures that utilize a spring-like framework that can be easily collapsed and folded for transportation and storage. Such popular designs are typified in, for example, our current and co-pending application Ser. No. 10/025,279.
These types of enclosures are inexpensive, lightweight, and convenient to use. However, one drawback in structures of this type is found in the lack of support available for the roof or upper portion of the enclosure. Early designs used the tension created by the pull of the side panels against the top fabric, but the tension applied to the top fabric was limited. Over time, the fabric of the enclosure stretches, and the framework elements lose their resiliency. Eventually, the roof or top portion of the enclosure sags and deforms, restricting head room inside the enclosure and allowing the collection of water and debris on the roof area. In addition, the relaxation of fabric throughout the structure causes an overall loss of rigidity throughout the structure over time.
It is desirable, therefore, to improve the structural integrity of existing collapsible structures by inclusion of lightweight and resilient frame elements that can be easily transported, inserted in the structure of the enclosure and removed with a minimum of difficulty, and that can be easily adapted to cause the roof or upper portion of the enclosure to conform to a particular profile, thereby elevating or extending a portion of the enclosure upward.

Collapsible structure with top supporting elements


An information processing apparatus connectable to an external device, having a first driver storage unit to store a first driver to control a connected external device in a general-purpose manner, a determination unit to determine whether or not a second driver, to control the connected external device in a device-specific manner exists in the external device, an acquisition unit to, if the determination unit determines that the second driver exits, obtain the second driver from the connected external device, and a second driver storage unit to store the obtained second driver.

In an information processing apparatus connectable to an external device such as a digital still camera, e.g., a printer or printer-based multifunction product with a digital still camera connection function, the types of connectable external devices connectable to the information processing apparatus are limited.
In such case where connectable combinations between the external devices and the information processing apparatus are limited, a user as an operator must obtain an external device such as a digital still camera and an information processing apparatus such as a printer or a printer-based multifunction product with a digital still camera connection function, corresponding to each other, at the same time.
Further, in a case where an external device such as a digital still camera with a new function is obtained, if the information processing apparatus such as a printer with a digital still camera connection function is old in comparison with the external device, the new function of the digital still camera cannot be fully performed, otherwise, in order to fully use the new function, it is necessary to prepare a new information processing apparatus such as a printer corresponding to the new function.
On the other hand, vendor-specific information on the peripheral device side can be transmitted to a PC without generating a vendor-specific PC driver by embedding the vendor-specific information (e.g., a media ID of a memory card) in general standard information and transmitting the vendor-specific information to the PC. However, the amount of transmittable information is limited, and further, vendor-specific operation control cannot be performed.
In this manner, conventionally, there is a limitation on the types of external device having a function which can be fully performed when the device is connected to an information processing apparatus, and the information processing apparatus and the external device cannot be effectively utilized.

Information processing apparatus, its control method and control program


An amplifying system with increased linearity is disclosed. The amplifying system includes a first gain stage with a first gain characteristic, a second gain stage with a second gain characteristic, and bias circuitry configured to substantially maintain alignment of distortion inflection points between the first gain characteristic and the second gain characteristic during operation. The bias circuitry is configured to further maintain alignment of the distortion inflection points between the first gain characteristic and the second gain characteristic over design corners by providing substantially constant headroom between quiescent bias voltage and turnoff of the first gain stage and the second gain stage. In some embodiments the first gain characteristic is expansive and the second gain characteristic is compressive. In other embodiments the first gain characteristic is compressive and the second gain characteristic is expansive. In some embodiments the first gain stage is configured to provide RF degeneration control of gain.

Traditionally biased amplifier stages have gain curves with inflection points that vary over design corners such as process, temperature, and supply voltage. Therefore, traditionally biased amplifier stages are not well suited for linearization through expansion and compression cancellation, since traditionally biased amplifier stages do not track each other. As a result, there is a large distortion cancellation error over design corners. Thus, there remains a need for amplifying systems to realize gain curves with constant distortion inflection points over the design corners.
Moreover, traditional constant small signal gain biased amplifiers usually come with a large variation of distortion characteristics. Thus, traditional constant small signal gain biased amplifiers are not well suited to use in complementary distortion cancellation schemes that are considered for improving linearization. Constant distortion biased amplifiers come with stable distortion characteristics that can be used in expansion-compression cancellation schemes, but they have large small signal gain changes over design corners such as process, temperature, and supply voltage. Thus, a need remains for techniques to stabilize the gain in constant distortion biased stages.


A strapping machine configured for and method for actuating the belt drive mechanism of a strapping machine during a loss of band carrying out the following steps: (1) polling the detector as to a proper shooting of the strapping band in the shooting direction up until the end of the shooting trajectory, and (2) for an improper shooting of the strapping band, activating the shooting and retrieval unit to retrieve the strapping band with a definite retrieval speed for a defined retrieval time so that the strapping band emerges from the shooting and retrieval unit opposite the shooting direction, and (3) actuating the drive of the back-tensioning unit so that the back-tensioning unit transports the strapping band back into the shooting and retrieval unit in the shooting direction.

A strapping machine is known, for example, from DE 196 02 579 A1. Besides the familiar parts that are present in such machines, such as machine frame, work bench, and band guide frame for leading the strapping band around the object being strapped as a loose loop, it has a band drive unit placed underneath the work bench. This comprises a combined shooting and retrieval unit for shooting the strapping band into the band guide frame and retrieving the strapping band from the band guide frame until the strapping band bears against the object being strapped. Moreover, a back-tensioning mechanism is often present for tightening the strapping band about the object, being dependent on the stack height.
The shooting and retrieval unit has at least one pair of rollers, between the gap of which the strapping band is led through by one of the rollers in the shooting and retrieval direction. The back-tensioning unit has another pair of rollers, between the gap of which the strapping band is likewise fed and can be clamped around the item being strapped in the machine by at least one of the rollers in the retrieval direction.
Finally, guide channel sections are provided to guide the strapping band through the band drive mechanism, which lead the strapping band brought up from a supply roll or a temporary storage device to the back-tensioning mechanism, between the latter and the shooting and retrieval unit, and from the latter in the direction of the band frame on the work bench. The guide channel sections are formed by cheeks which guide the strapping band on either of its flat sides, being configured as webs or side surfaces of larger prismatic bodies.
A typical problem in the operation of such a strapping machine sometimes occurs due to a faulty handling of the strapping band. Thus, for example, the leading end of the band cannot reach the welding head due to obstacles in the band guide frame and therefore the detector situated here, for example, in the form of an end switch, is not activated to detect the leading end of the band at the end of its shooting trajectory in the band guide frame. The control system of the strapping machine recognizes this and it then arranges for a retrieval of the strapping band, usually until it emerges backward from the pair of drive rollers of the band drive mechanism opposite the shooting direction.
This fault situation is normally monitored by a sensing mechanism, which detects the condition when the strapping band emerges from the shooting and retrieval unit opposite the shooting direction.
To remedy the fault in the strapping machines known thus far it was necessary to open the band drive mechanism and manually thread the strapping band into the shooting and retrieval unit, so that the shooting process can start over again. This leads to a substantial down time for the strapping machine, which is basically undesirable and in an extreme case can lead to a shutdown of the entire production line when the strapping machine is integrated as part of a continuous production process for print products, for example.
In EP 1 489 005 A2 a corresponding method is indicated for actuating a band drive mechanism that can eliminate the described fault situation without manual intervention in substantially less time. According to this, the back-tensioning mechanism can be reversed in its drive direction so that when a fault is detected—that is, a band loss in the shooting and retrieval unit—the strapping band is transported back almost automatically to the shooting and retrieval unit.
A drawback with this control method is the fact that the fault situation and the driving of the band must be detected by means of a suitable sensor, e.g., an incremental encoder on the pressing roller of the shooting and retrieval unit. This signal is then further processed in the control program and incorporated into the control sequence. This requires additional expense for control technology and apparatus.
This drawback is even more glaring for the strapping machine of DE 603 18 160 T2, which is different in its design makeup of shooting, retrieval and back-tensioning unit. Here, the band length that was shot out and retrieved in the fault situation is detected and the band is pulled back with two different band speeds to the starting position before being threaded once again.

This patent is subject to a terminal disclaimer.

Method for actuating the band driving device of a strapping machine and corresponding strapping machine


A life raft canister is launched from a below deck doorway. A launcher is activated and pneumatically opens a below deck door, exposing the doorway. The same inflation tank inflates an elongated bladder that forces the life boat canister out of the doorway. The canister drops to the sea where the life boat is deployed from the canister. The life raft auto-inflates. As a result, a life raft is deployed from below-deck.

1. Field of the Invention
The invention relates to ships. More particularly, the invention relates to a ship-board life raft handling apparatus. Most particularly, the invention relates to an apparatus for launching a life raft from below-deck.
2. Discussion of the Related Art
U.S. naval vessels carry life boats or life rafts for the emergency evacuation of the crew. Life boats and life rafts are stored on deck and lowered to the sea by means of davits. Because a life raft is uninflated for storage, it takes up less space than a life boat and is often the preferred evacuation vessel. A life raft is stored on deck in the uninflated and folded state in a life raft canister and then inflated immediately before use. A canister allows the life raft to be dropped from deck into the sea which eliminates the need for davits. The life raft is deployed from the canister when the sea painter connected to the inflation system is pulled, actuating inflation valves. Included in the canister is inflation means such as an inflation gas cylinder attached to the folded life raft. The life boat canister is periodically opened and inspected for integrity of the life raft and for gas pressure in the inflation gas cylinder.
U.S. naval vessels typically carry life rafts in preference to life boats. Smaller vessels carry 6 to 15 person life rafts. Standard Navy life rafts are the 25-person Mark 7 (Mk-7) and the 50-person Mark 8 (Mk-8). These life rafts are made of polyurethane coated nylon fabric and are stored with a gas inflation cylinder in a life boat canister. The canister is a hard fiber glass shell. The Mark 7 raft takes 550 cubic inches of gas to inflate from an inflation cylinder at a minimum test pressure of 4500 psi (pounds per square inch). The Mark 8 raft takes 1636 cubic inches of gas to inflate from two inflation cylinders at a minimum test pressure of 3500 psi (pounds per square inch). The inflation cylinders have a 15 year service life and contain carbon dioxide, nitrogen or air. For human safety, air is the preferred gas. Air also demonstrates less contraction than carbon dioxide in arctic temperatures.
Life raft canisters are stored on a ship deck to facilitate rapid deployment overboard in an emergency. It is statistically unlikely that a ship will sink during its useful life, and require evacuation to save lives. For safety awareness, the crew is periodically drilled to maintain their skills in handling a life raft. Likewise, the life raft canister is periodically opened and inspected to assure that the raft is in good working order and the inflation gas cylinder is up to standard operating pressure.
Life raft drills are carried out to reduce the inherent danger and inefficiency inherent in a real evacuation. Accordingly, a naval ship carries an excess of life raft capacity over the nominal crew size to accommodate damaged equipment and deviations in distribution and timing during evacuation. Life raft canisters are given priority in taking up deck space. Other essential equipment claims remaining deck space. As a result there is a conflict for the use of deck space between carrying on a ship's sailing and military functions and storage of emergency equipment.

The United States of America as represented by the Secretary of the Navy


A code is communicated between the billing server and subscription server. The billing server receives a code request text message from the user device. The billing server identifies a carrier server from the code request text message. The billing server receives an authorization text message from the user device in response to an authorization request text message and charges an account of the carrier server that has been identified. If the charge has been successful, then the billing server transmits a code redemption text message to the user device including the code and a link to a redemption page of a website of a subscription server. The subscription server processes redemption to a code and transmits an account set up page to the user device.

1). Field of the Invention
This invention relates to a method and system of processing a sale of a subscription.
2). Discussion of Related Art
Magazine publishers normally rely on traditional payment methods to establish or renew subscriptions for their publications. A user may for example purchase a magazine off the shelf in a store. A postcard is often located within the magazine. The user can enter their delivery address on the postcard and send the postcard to the publisher together with a check for payment. After a period of time, typically twelve months, the user is sent a renewal notification, which the user then returns to the publisher with another check.
Users may also register for subscription on a publisher website. The publisher website will collect delivery address information from the user and receive payment by credit card.
The establishment of an account may be a barrier for most users. Frequently, a user will not purchase a magazine or will not go online on a publisher website because of the amount of effort that is involved in terms of time and the number of fields that have to be filled out. Even after the user has purchased the magazine or they have gone online, the initial effort of entering delivery address information may be too much for some users and they may terminate the process of establishing an account, which results in them not being converted into subscription customers.
A consumer who shops for goods or services online may often be given the option to use a selection of payment sources during checkout, such as payment by credit card, debit card, payment from an account held by an institution, or to charge for a purchase on their phone bill. When the consumer selects to charge to their phone bill, a merchant server instructs a billing server which is aligned with a carrier server to carry out the charge. The billing server usually communicates with a consumer mobile phone to confirm the charge before placing the charge on the phone bill at the carrier server.
Consumers also purchase subscriptions online, typically for services such as music or movies, and then make repeat payments on a monthly or other billing cycle. These subscriptions are usually charged directly to a credit card account held by a financial institution. Repeated communications with the consumer to confirm each renewal charge is not required in such a situation. However, if such a charge is submitted by a merchant server to a carrier server, the carrier server typically has a requirement to confirm the charge with the consumer mobile phone. A billing cycle may go by wherein the consumer has neglected to confirm the charge, in which case the subscription would be lost to the merchant.


A method for manufacturing labels and for applying each of the labels to an end wall of a cigarette packet. The method includes separating the labels from a continuous web moving in a horizontal direction with the width of the web parallel to a vertical plane. Only one side of the web is provided with printed areas for a succession of the labels, and severance cuts are provided in the web to form the labels between the areas. Separation of the labels occurs at the cuts. After the labels are separated, they are continuously transported by a suction conveyor belt moving in a vertical plane substantially parallel to the vertical plane of the web. The labels are held separated from each other by negative pressure from the belt which acts on the printed side. Glue is applied to the print-free side of the labels on the belt by a phased and non-contact application of at least on row of successive glue spots extending along the longitudinal dimension of the label. Then the labels are applied to the packets.

The invention relates to a method and device for manufacturing (printed) band labels, especially revenue stamps, and for applying same to packets, preferably on an end wall of a cigarette packet, by gluing.
The application of band labels (revenue stamps), i.e. of generally rectangular long blanks of paper or the like, to packets is a special problem in the manufacture of cigarette packages. Each of these packets is provided during manufacture with a revenue stamp, which normally extends in the region of an end wall of the cigarette packet transversely across same, making a U-shaped fold. The label (revenue stamp) is attached to the packet by gluing. Manufacture, gluing and conveying of the labels are a particular problem on high-capacity packaging machines.

Method for manufacturing labels and applying them to packets


A respiratory interface device including a fluid coupling device having a main body and an exhalation plate having a plurality of vent holes, the exhalation plate being separate from and coupled to the main body. The present invention further relates to a fluid coupling device including an exhaust portion having a plurality of vent holes having a tapered shape. A set of the vent holes has an incident angle that radiates and originates from a common point. The present invention also relates to an exhalation mechanism including a plurality of vent holes defined by a continuous straight inner wall extending from an interior surface to an exterior surface wherein an exterior circumference of the vent hole is offset with respect to an interior circumference.

1. Field of the Invention
The present invention relates to respiratory interface devices for transporting a gas to and/or from an airway of a user, and, in particular, to a respiratory interface device, such as a mask, that includes a fluid coupling device having various improved exhaust venting mechanisms.
2. Description of the Related Art
A variety of respiratory masks are known which contact the areas of the nose and/or mouth of a human user. The uses for such masks include high altitude breathing (aviation applications), swimming, mining, fire fighting, and various medical diagnostic and therapeutic applications.
In many such applications, a gas is provided at a positive pressure within the mask for consumption by the user. The gas is typically supplied to the user through an air inlet, such as an opening, provided in the mask. In addition, in order to facilitate the delivery of the gas to the mask, a fluid coupling device, such as a swivel conduit, is normally coupled to the air inlet opening of the mask. Specifically, one end of the fluid coupling device is coupled to the inlet of the mask and another end of the fluid coupling device is coupled, perhaps through one or more additional conduits, to an external gas source, such as a blower of a ventilator or other suitable device.
Respiratory masks also often include a mechanism for purging carbon dioxide generated by the user from the mask to the atmosphere. In one known respiratory mask assembly, the venting mechanism is provided in the fluid coupling device (e.g., an elbow device) connected to the air inlet of the mask in the form of a number of vent holes provided directly in the fluid coupling device when it is manufactured, such as by a molding or an assembly process.
As will be appreciated, the particular manufacturing process that is employed places limits on how the vent holes can be formed. For example, in a molding process used to form an elbow device, the shape and particular configuration of the vent holes is limited by the mold. Specifically, due to one or more undercuts, typically included in the mold used to make the elbow device, it may be difficult and impractical to form vent holes in the elbow device which taper from a large diameter on the interior of the elbow device to a smaller diameter on the exterior of the elbow device.
The present inventors recognized that there is room for improvement in the area of masks and similar respiratory interface devices, and, in particular, in the area of achieving a good venting mechanism for exhausting gases such as carbon dioxide generated by the user from the mask to the atmosphere.


An electro-optical device includes a plurality of scanning lines that extends in a row direction, a plurality of data lines that extends in a column direction, a plurality of pixels which are provided at intersections of the scanning lines and the data lines and whose gray-scale levels are designated by data signals supplied through the data lines, a common electrode that is provided so as to be opposite to pixel electrodes, a shift register that outputs sampling signals to sequentially select a plurality of blocks each composed of a plurality of the data lines, in a period where the scanning lines are selected, a sampling circuit that samples the data signals to the plurality of data lines belonging to the block selected by the sampling signal, respectively, a data signal supply circuit that changes the potential of the data signal into a higher level and a lower level than a predetermined potential in every predetermined period and then alternately outputs the potentials, and a correction circuit that superimposes, on the data signals, correction signals for correcting potential errors that are generated in the data lines belonging to each of the blocks, corresponding to the potentials of the data lines.

1. Technical Field
The present invention relates to a technique for preventing the deterioration of display quality appearing in a column direction.
2. Related Art
In recent years, projectors in which, first, a small image is formed by an electro-optical panel using, for example, liquid crystal and then the small image is enlarged by an optical system to be projected onto a screen have come into widespread use. The projector does not have a function of forming an image, but is supplied with image data (or image signals) from a host device, such as a personal computer or television tuner. The image data designates the gray-scale levels (brightness) of pixels, and is supplied by vertically and horizontally scanning the pixels arranged in a matrix. Therefore, it is preferable to drive the electro-optical panel used for the projector in this manner. Thus, generally, the electro-optical panel used for the projector is driven in a so-called dot-sequential method in which scanning lines are sequentially selected, data lines are sequentially selected one by one in a period in which one scanning line is selected (one horizontal scanning period), the image data is converted into image signals suitable for driving the liquid crystal, and then the converted signals are supplied to the selected data line.
Meanwhile, in recent years, there has been proposed a technique of improving the resolution of a display image. A high-resolution display image can be achieved by increasing the number of scanning lines and the number of data lines. However, in this case, the larger the number of scanning lines is, the shorter one horizontal scanning period becomes. In addition, in the dot-sequential method, the larger the number of data lines is, the shorter the period where the data lines are selected is. Therefore, in the dot-sequential method, it is difficult to secure a sufficient time to supply the image signals to the data lines as the resolution of displayed images improves, which results in insufficient writing of the image signals onto the pixels.
Therefore, in order to solve the problem of insufficient writing, there has been suggested a phase-expansion driving method (see Japanese Unexamined Patent Application Publication No. 2000-112437). In the phase-expansion driving method, blocks each composed of a predetermined number of data lines, for example, six data lines, are simultaneously selected in one horizontal scanning period, and image signals to be supplied to pixels corresponding to the selected scanning line and the selected data lines are expanded in the time axis direction and are then supplied to the six selected data lines, respectively. In the phase-expansion driving method, it is possible to secure a time when the image signals are supplied to the data lines that is six times longer than that in the dot-sequential method. Thus, the phase-expansion driving method is suitable for improving the resolution of a displayed image.
However, when the size of a panel increases, manufacturing costs thereof also increase. Therefore, it is preferable to increase the number of scanning lines and the number of data lines per unit length in order to improve the resolution. In particular, when the number of data lines per unit length increases, an arrangement pitch between the data lines is narrowed, which causes capacitive coupling to easily occur between the data lines. As a result, a voltage variation of a data line has an effect on adjacent data lines, which leads to the deterioration of the display quality.

Electro-optical device, signal processing circuit thereof, signal processing method thereof and electronic apparatus


When a stem switch (8) is pulled out, a switch signal forming unit 9 outputs a signal (RS) indicating that effect, a control unit (13) receives the signal (RS) and starts clocking by a timer (13a). The control unit (13) receives a signal (HS) output from an electricity-generation detecting unit (12) within the clocking period, detects the electricity generating operation of an electricity generating unit (10), and outputs a signal (CS) indicating that effect. A narrow pulse forming unit (7) forms a narrow pulse having a width of such a degree that the motor (5) is not driven based on the signal (CS), and outputs the narrow pulse to a motor driving circuit (4). The motor driving circuit (4) flows a fine current through a coil (4a) which drives the motor (5) based on the narrow pulse. An external device detects a variation of the narrow pulse, thereby confirming whether electricity is generated.

In electronic devices of recent years, there is a tendency of lighter weighted, thinner thickness, shorter length and smaller size, but there is a problem on securing a high output and a small power source. To solve the problem, attempt has been made to lower the power consumption and to elongate the lifetime of a secondary battery of each of various devices that constitute the electronic device.
The best example of the electronic device of lighter weighted, thinner thickness, shorter length and smaller size is a portable electronic watch. The portable electronic watch has smaller power consumption and smaller size as compared with a mobile phone which has remarkably been developed in recent years. Therefore, even when a primary battery such as a button type lithium battery is used as an embedded power source, changing frequency is once in several years, which is sufficiently practical. However, for users, it is troublesome to change battery even once in several years, and it requires costs. Even when a secondary battery is used as the embedded battery, it is troublesome to charge the battery. Especially with the electronic watch, it is necessary to reset the time after the battery is changed, and therefore it is not preferable to repeatedly inflict such operation on users.
Thereupon, an electronic watch in which an electricity generating device that generates electricity to be stored in the secondary battery is embedded together with the secondary battery, has been commercialized. A solar cell which converts optical energy to electricity, a thermionic element which converts energy due to a temperature difference between body heat and outside air temperature into electricity, a rotating weight which converts kinetic energy into electricity, or the like is used as the electricity generating device.
Not only a digital display type electronic watch using a liquid crystal but also an analogue display type electronic watch using hands in many cases includes an IC chip which generates a reference clock or controls a motor which rotates the hands. The electricity generated by the electricity generating device is consumed as driving voltage of the IC chip or the motor through the secondary battery.
Therefore, in the electronic watch having the electricity generating device, it is important that the electricity generating device is excellent in order to keep the stable watch operation, and the operation is carefully confirmed during producing procedure also.
Especially, the electronic watch is small in size, and therefore the operation of the electricity generating device alone is usually checked first in pre-step in which constituent parts of the electronic watch are incorporated. Subsequently, the electricity generating device which was confirmed as a fair quality is incorporated into the electronic watch and the operation of the electronic watch is confirmed.
However, electricity to some extent is stored in the secondary battery which is incorporated together with the electricity generating device. Therefore, an electronic watch which is operated using the electricity stored in the secondary battery sometimes shows normal watch operation immediately after the incorporation, even when the electricity generating device is damaged during incorporation. The damage of the electricity generating device mentioned here includes damage of the electricity generating device itself caused by generation of static electricity during the incorporation, and also includes such when electric wiring between the electricity generating device and the secondary battery is disconnected and the electricity generating operation of the electricity generating device can not be confirmed visually.
In an electronic watch which was shipped as being a normal watch for the above reason, the stored electricity of the secondary battery runs out after a while, and the watch operation is stopped.
Thus, after the electronic watch was assembled, i.e., in a product form immediately before shipment, an electricity generating device capable of confirming the operation has been required.
It is an object of the present invention to provide an electronic watch capable of easily confirming the operation of a built-in electricity generating device in a product form.


An improved pump-head structure, which has a valve annulus mounted on the inlet to the lower end of a liquid accumulator of the pump-head structure to prevent leakage of a liquid from the liquid accumulator. A plunger valve is connected to the valve annulus via a spring piece, which exerts a downward force on the plunger valve and thus maintains the inlet of the lower end of the liquid accumulator forcedly and tightly closed under normal conditions by the downward action of the plunger valve.

Generally, a liquid pumping head has widely been used for dispensing a liquid or a cream out of a container (such as a bottle or a can, etc.). The conventional pumping head as shown in FIG. 1 comprises a container cap "A" fixed onto a container for liquid; when the nozzle head "B" is pushed down and released, the piston "C" will pump the liquid in the container up. As soon as the piston "C" is pushed down, the spring "D" will be pressed downward to produce a dynamic force. As soon as the nozzel head "B" is released, the spring "D" will push the piston "C" upward to pump a liquid in the container up and into the liquid accumulator "F" through a delivery tube E; when the nozzle head "B" is pushed down again, the liquid pressure in the liquid accumulator "F" will cause the ball valve "G" to close the inlet of the accumulator, and to force the liquid to flow upward and out of the nozzle head "B".
Generally, the aforesaid ball valve "G" is made of plastics, or metal, or other plastic materials to provide a check function; since most of the liquids are viscous products (such as creams, shampoos or detergents), such liquids tends to form a coating layer on the ball valve "G" upon flowing through the valve when this occurs, after the ball valve "G" is fallen upon the inlet of the liquid accumulator "F", the inlet would not be closed completely as a result of an insufficient pressure of the ball valve "G"; in that case, the liquid in the liquid accumulator "F", if not being exhausted, would leak into the container. After a period of time, the nozzle head "B" would have more less difficulty to pump out the liquid, unless the nozzle head is compressed several times, and that would cause an inconvenience to a user.

Container mounted pump with improved check valve structure


A power converter configured to be mounted on an electrically driven vehicle comprises a control board that controls a power module including a semiconductor device, a connector provided on the control board so as to be connected to an external controller, a strong electric component arranged so as to overlap the control board, and a housing that houses the control board and the strong electric component. A bottom portion of the housing is formed to swell in a convex-shaped manner, a part of the strong electric component is housed in an area of the housing that swells in the convex-shaped manner, and the strong electric component is formed so that a projection area thereof to the overlappingly arranged control board is smaller than a surface area of the control board. The connector is arranged in an area of the control board broader than a projection plane of the overlappingly arranged strong electric component to the control board.

In the prior art, there was proposed a power converter configured to be mounted on an electrically driven vehicle such as an electric vehicle or a hybrid vehicle, by which excellent vehicle mount workability is obtained even when a large capacity smoothing electrolytic capacitor is provided (refer to JP 11-136960 A). This power converter comprises a power module as a three-phase inverter circuit consisting of a semiconductor device, a control board for controlling the power module, and an input current smoothing capacitor. A plurality of cylindrical electrolytic capacitors connected in parallel with each other are housed in a metal capacitor casing having a flat can shape while they are arranged side by side along a line in an extending direction of the control board. The metal capacitor casing is arranged to cover the control board. A connector for external connection of the control board is arranged on the control board covered by the capacitor.

Power converter mounted on electrically driven vehicle


To place material accumulations, which is unavoidable upon blow-molding a bottle, in a separable two-part blow mold form away from a bottom fold line (2) of the bottle, in which the bottom portion of the bottle is formed with a generally inverted V-shaped depression (3) and the apex of the V defines the bottom fold line, the separating seam (9) in the bottom portion is placed at an angle (.alpha.) with respect to the bottom fold line (2), a central region of the bottom separating seam intersecting, at least approximately, the bottle axis (17). The mold form has a body separating plane (12) and an end portion separating plane (16, 23, 25) in which the end portion separating plane is angled by the angle (.alpha.) with respect to the body separating plane. Upon blow-molding, the bottom seam (9) and the bottom fold line (2) will be non-congruent, and material accumulation (11) upon blow-molding the bottle will occur at locations remote from the bottom fold line (2), thus not interfering with folding the bottle along the bottle fold lines (2, 15). This method is suitable for bottles of integral shape, as well as bottles having an integral molded-in handle.

U.S. Pat. No. 5,080,260, by the inventor hereof, the disclosure of which is hereby incorporated by reference, discloses a bottle made of thin-walled plastic produced by blow-molding process. A bottom part is preformed with an inwardly extending, in cross section essentially V-shaped folded part which defines an elongated inner bottom fold line. The inner bottom fold line merges smoothly with body fold lines extending longitudinally of the bottle. The inner bottom fold line and the longitudinal fold line are in a single plane. The cross section of the bottle may be circular, rectangular, or hexagonal and is unitary with the pouring spout which extends, preferably with a reduced diameter, from the top portion of the bottle. Upon folding the bottle along the seam lines, and expelling all air from the inside, the bottle can be compressed and, upon tightly closing the spout, reduced to small size.
Upon blow-molding such a bottle, a seam will form at the junction of two mold parts. This, unavoidably, results in some thickening of the material. To prevent congruence of the fold with the wall thickness, it has been proposed, as described in the aforementioned patent, to place the separating plane of the blow mold form halves transversely to the longitudinal plane of the bottle. This results in excellent foldability of the bottle.
It has been found that shifting the separating plane of the blow mold in bottles in which a handle is formed inherently and as part of the bottle does not make it possible to place the seam line transversely to the bottom fold, since it would no longer be possible to remove the blow-molded bottle from the blow mold form and, further, the two halves of the blow-mold form would not be mirror-symmetrical. Otherwise, expensive multiple-part special forms, with sliders and the like, would have to be used, which makes manufacture of such a bottle expensive.
If the same folding principle as that described in the earlier U.S. Pat. No. 5,080,260 is carried out in bottles in which the entire separating plane of the bottle halves or, rather, of the mold halves, are placed in a longitudinal plane of the bottle which coincides with a central plane, also including the bottom fold line, the separating thickening of the bottle becomes congruent with the bottom fold line. This is undesirable, since it interferes with folding. In the manufacture of bottles of this type, a hot extruded tube of plastic material is gripped by two form halves, and compressed in the region of the pinch edges of the mold halves. At the ends of the respective pinch seams, then, material from the plastic tube will accumulate. This material has roughly crescent-moon shape. The thickening of the material in the region of the bottom of the bottle can be a multiple, and it has been found typically up to six times the normal wall thickness. This accumulation of material, practically unavoidable in blow-molding, interferes with folding of the bottom of the bottle along its longitudinal plane; in extreme cases, and excessive accumulation of material, may make folding the bottle impossible. The accumulation of material upon blow-molding the bottle is located inwardly, at least in part, within the inverted V-shaped bottom of the bottle. Thus, the thickening of the material does not enhance the support of the bottle, for example on a support surface such as a shelf or table, and does not contribute to stabilizing the weight of the bottle.

Foldable plastic bottle, blow mold form to make the bottle, and method of making the bottle


A process for adjusting a circulating fluidized bed, wherein a part of the carrier gas is recovered, mixed with a propellant and returned to the fluidized bed as a carrier gas.

This invention relates to a method of adjusting a circulating fluidized bed and to the use of the method.
Methods of adjusting a circulating fluidized bed are known. In E. Henglein, Lexikon Chemische Technik, VCH Verlagsgesellschaft, 1988, pages 676 to 678, fluidized-bed processes are described, including the mode of function of a circulating fluidized bed. It is emphasized that the carrier gas is supplied to the reactor from the bottom. From E. Henglein, Lexikon Chemische Technik, VCH Verlagsgesellschaft, 1988, page 267, it is known that continuously mixing two gases can advantageously be effected by means of an injector mixer.
The DE-OS 39 08 972 describes an apparatus for producing pulverized silicon nitride. The production is effected in a fluidized bed, where nitrogen is used as carrier gas for forming the fluidized bed.
There is furthermore known the procedure, where as carrier gas there is used at least one partial stream of the pure gas discharged from the cyclone of the circulating fluidized bed. In general, the pure gas is discharged from the cyclone by means of a rotary-piston blower and again supplied to the reactor from the bottom. In general, the gases produced in the reactor contain a major amount of acid components, chiefly HCl and SO2. At the process temperatures, however, these acid components relatively quickly lead to a corrosive damage of the plant components, in particular of the rotary-piston blower used. In addition, the pure gases must be cooled to below the dew point, before they are passed through the rotary-piston blower. The spray of the gases at dew point contains major amounts of salts at the saturation limit, which during the compaction in the rotary-piston blower are precipitated, adhere to and block the rotary-piston blower after a relatively short operating period.
It is therefore the object underlying the invention to create a method of adjusting a circulating fluidized bed, where corrosive damages of the plant components and damages due to the precipitation of salts are largely avoided.
The object underlying the invention is solved by a method of adjusting a circulating fluidized bed, where as partial amount of the carrier gas there is used at least one partial stream of the pure gas discharged from the cyclone on at least one point of the circulating fluidized bed, and prior to its introduction into the circulating fluidized bed the pure gas used as partial amount of the carrier gas is mixed in an injector mixer with 10 to 90 wt-% propellant, based on the amount of the partial stream of the pure gas discharged from the cyclone, and the mixture is supplied as carrier gas to the circulating fluidized bed. The propellant used includes for instance N2, air or steam.
The term xe2x80x9ccirculating fluidized bedxe2x80x9d refers to a fluidized bed with strong movement of solids, high expansion, internal back-mixing, and a high concentration of solids at the reactor outlet with a partial recirculation of the solid. It substantially consists of a vertically arranged reactor, a subsequently provided cyclone and of a return line for recirculating solids discharged from the cyclone into the reactor.
The term xe2x80x9cinjector mixerxe2x80x9d refers to the generally known injectors. In these injectors, the one partner of the mixture is centrally introduced at high speed into a mixing line, while the second gas stream enters the line via a remaining annular gap. Due to the high flow rates and the difference in velocity at the point of entrance, there is a great turbulence in the mixing line, so that a continuous mixing of the two gases can occur.
The supply of the mixture is effected on at least one point of the circulating fluidized bed. The mixture can for instance be supplied to the reactor of the circulating fluidized bed from the bottom. It is, however, also possible to supply the mixture at a point of the return line for the solids between cyclone and reactor.
It was advantageously found out that by means of the inventive mixing of the pure gas with the nitrogen corrosive damages in the plant components and damages due to a precipitation of salts can largely be avoided. A further advantage consists in that the provision of a rotary-piston blower can completely be omitted. The pure gas used as carrier gas can be passed through the injector mixer without previous cooling and again be supplied to the reactor, so that as compared to the use of a rotary-piston blower the cooling system for the pure gas, the cooling energy and heating costs are saved. The preliminary pressure of the propellant, which generally is about 2 to 50 bar, preferably 3 to 25 bar, and the pressure in the reactor, are advantageously sufficient for transporting the partial amount of the pure gas to be used as carrier gas via the injector mixer to the reactor.
A preferred aspect of the invention consists in that the solids to be discharged from the cyclone are at least partly passed through a U-shaped return line and are again supplied to the reactor, and the mixture is at least partly introduced into the lower portion of the U-shaped return line. The U-shaped return line may constructively be designed as siphon. The introduction of at least a partial amount of the mixture into the lower portion of the U-shaped return line leads to the advantageous formation of a further fluidized bed in the lower portion of the U-shaped return line. With this procedure it is possible to use other gases, for instance nitrogen, as carrier gas for the formation of the fluidized bed in the reactor. It is, however, very well possible to introduce part of the mixture into the lower portion of the U-shaped return line, and to supply the second part of the mixture to the reactor from the bottom as carrier gas. When the mixture is at least partly introduced into the lower portion of the U-shaped return line, it is advantageously possible to prevent corrosive damages in the plant components and damages due to a precipitation of salts, where here as well the provision of a rotary-piston blower can be omitted. A further advantage of this procedure consists in that by introducing at least a partial amount of the mixture into the lower portion of the U-shaped return line a pressure compensation between the reactor and the cyclone can be realized relatively easily. At the same time, the transport of the solids between the cyclone and the reactor in the return line is advantageously facilitated.
In accordance with a further aspect of the invention it is provided that 3 to 10% of the mixture are introduced into the lower portion of the U-shaped return line. The remaining part of the mixture is advantageously supplied to the reactor from the bottom as carrier gas. In this way, the respective formation of the fluidized bed in the reactor or in the return line is optimized, where at the same time damages and damages due to salt deposits in the plant components can be avoided.
Subject-matter of the invention finally is the use of the method for producing Fe2O3 or Fe3O4. It is generally known to produce Fe2O3 (red pigment) or Fe3O4 (black pigment) in the circulating fluidized bed. The production of Fe2O3 is effected in an oxidizing atmosphere. The production of Fe3O4 is effected in a neutral or weakly reducing atmosphere. However, the raw pigments used have a relatively large content of chlorine and sulfur, which in the reactor of the circulating fluidized bed is converted into HCl and SO2. When a partial stream of the pure gas discharged from the cyclone is used as carrier gas for the formation of the fluidized bed, the pure gas containing HCl and SO2 leads to corrosive damages of the plant components. Due to this fact, the use of a rotary-piston blower, for instance for transporting the pure gas from the cyclone again into the reactor, is only briefly possible, as the rotary-piston blower is no longer operable even after relatively short operating periods due to salt deposits and the corrosive damages caused by the acid components and the relatively high process temperatures. The corrosive gas allows an operation of the rotary-piston blower only with an extremely high effort (cooling, scrubbing of noxious gas, condensation and spray removal of the pure gas prior to entrance into the rotary-piston blower, use of expensive materials). The production of Fe2O3 or Fe3O4 can, however, advantageously be realized by using the method.

Method of adjusting a circulating fluidized bed and use of the method


A slide actuated holding clamp for holding a connector block stationary while a push test is performed on a conductor secured to the connector. The clamp comprises a body portion having a bore extending longitudinally therethrough and a portion forming a channel. A locking member is pivotally disposed within the channel and includes a locking finger portion and a lower shoulder portion. An actuating member is slidably disposed within the channel and includes a pin member extending transversely therethrough which causes the locking member to move pivotally such that the locking finger portion is moved outwardly of the channel when the actuating member is moved in a first direction. When the actuating member is moved in a longitudinally opposite second direction, the pin member abuttingly engages the lower shoulder portion, thereby causing the locking member to move pivotally such that the locking finger portion is retracted to a position within the channel. A small, conventional air cylinder is coupled to the actuating member via a linkage rod and a clevis to urge the actuating member slidably in the first and second directions in response to the application of air pressure thereto. The clamp will hold a connector stationary while large push forces are exerted on conductors coupled to the connector with only a very small force applied by the air cylinder. The design of the clamp does not require the air cylinder to exert a counter force in proportion to the push force being exerted on the connector.

1. Technical Field
This invention is related to clamping mechanisms, and more particularly to a slide actuated holding clamp for holding a connector of a vehicle wiring harness securely stationary while a push test is performed on a conductor secured to the connector.
2. Discussion
Clamping mechanisms are used in a wide variety of applications. One application in particular where such devices are helpful is in enabling off line harness testing to be performed on electrical connectors such as those used on a vehicle wiring harness. To help ensure that electrical terminals are going to remain coupled to their associated connectors and will not become disengaged from their connectors due to tension exerted along various lengths of the wiring harness, such as during the assembly of a vehicle, or from vibration, jarring, etc., "push tests" are frequently conducted on connector assemblies. Push tests involve applying a force to the end of a terminal of a conductor while the terminal is secured to its associated connector. Typically, a test force of about five pounds is applied to the terminal of the electrical conductor while the terminal is releasably secured to an associated connector.
In order to hold the connector stationary during a test the connector is typically fitted into a mounting block or a test module which consists of a pocket with some form of holding device coming over a rear end portion of the connector. Since many connectors have multiple terminals connected thereto, and often as many as fifty or more terminals to a single connector, when a five pound test force is applied to each terminal the total force exerted on the connector may range up to or over 250 pounds.
Previously designed holding devices typically used an air cylinder having a diameter which was required to be in proportion to the push force being applied to the connector. Accordingly, for connectors with many terminals a relatively large cylinder was required to supply an adequate holding force to securely hold the connector stationary in response to large push forces being exerted on the connector. Since there is generally very limited space in which to locate the air cylinder, the amount of holding force that could be applied to a connector, and thus the number of terminals that may be checked during a single push test, was limited to the construction of the mechanism and the diameter of the air cylinder which could be implemented into the mounting block or test module holding the connector under test.
Accordingly, it is a principal object of the present invention to provide a slide actuated holding clamp apparatus that is very compact and which is well adapted to fit many different test applications involving electrical connectors.
It is a further object of the present invention to provide a slide actuated holding clamp apparatus which is operable to securely hold a connector under test, where the connector has a relatively large plurality of terminals connected thereto, upon each of which is exerted a test push force of about five pounds, and which will hold the connector securely stationary with a minimum amount of force being exerted by active (i.e., moving) components of the clamp.
It is yet another object of the present invention to provide a slide actuated holding clamp apparatus which is relatively compact, inexpensive to manufacture, and adapted for use with a wide variety of electrical connectors.
It is still another object of the present invention to provide a slide actuated holding clamp apparatus which may be pneumatically controlled via a suitable external fluid pressure supply device such as an air compressor.


A test system and method of performing a run-time measurement for calibration of a device used for time-of-flight measurement are disclosed. The method comprises: providing a measurement device, a device under test and a directive component having three ports; connecting the directive component to a transmission port of the measurement device and a reception port of the measurement device; generating a signal by a signal generator; forwarding the signal to the directive component; receiving at least a response by a signal receiver; and determining a loop time indicative of the run-time between the directive component and the device under test as well as a time of internal processing of the device under test, wherein the loop time is independent of a signal processing time of a signal path between the measurement device and the directive component.

Ultra wide band (UWB) devices are known in the state of the art that are used for so-called ranging by time-of-flight measurements. The respective time-of-flight measurement is performed by means of two or more devices wherein the respective distance is measured by means of a message ping-pong between the respective devices while calculating the time, the packets needed to travel over the air.
The simplest method is called single sided two way ranging (SS-TWR). However, this method is inaccurate due to an allowed clock error up to 20 ppm. Therefore, the so-called double sided two way ranging (DS-TWR) is typically used in practice.
For this method however, it is necessary to calibrate the respective devices used for the time-of-flight measurement appropriately. Particularly, an error of a participating ultra wide band device shall correspond to approximately some 10 ps, ensuring the required clock error in the entire measurement system for time-of-flight measurement. In this regard, it is to be noted that 100 ps correspond to a distance of 3 cm.
The techniques known so far for calibrating the devices used for time-of-flight measurements are quite complex and, therefore, time consuming and expensive.
Accordingly, there is need for a simple and cost-efficient manner to calibrate a device used for time-of-flight measurement.

Method and test system for performing a run-time measurement