An apparatus includes a substrate, a magnetically soft underlayer on the substrate, and a plurality of generally cubic FePt nanoparticles on the magnetically soft underlayer, wherein the nanoparticles have a magnetization in a direction substantially normal to a surface of the magnetically soft underlayer. The FePt nanoparticles can have magnetically easy axes perpendicular to the surface of the soft underlayer.

Synthesis and self-assembly of FePt nanoparticles have been of great interest to the data storage industry as a possible means for making nanoparticle-based magnetic media which can enable recording densities beyond 1 Tbit/in2. The magnetic bits, which record data in conventional thin film magnetic media, are comprised of many grains. In order to achieve high recording densities with bits having well-defined shapes and boundaries, it is necessary to reduce the so-called transition jitter, which is the dominant noise source in today's media. This is usually accomplished by decreasing the size of the grains such that they remain significantly smaller than the bit size. If the grains become too small, however, thermal fluctuations may cause individual grains to switch randomly, thereby destroying the bit information over time. To avoid that problem, hard magnetic materials systems such as L10 phases or high anisotropy rare-earth transition metal systems are being developed, allowing small grains to remain thermally stable. FePt is the most prominent L10 candidate material for this approach. See for example D. Weller and A. Moser, IEEE Transactions on Magnetics, Vol. 35, pp. 4423-4439 (1999). A big limitation of these materials is that typical synthesis methods produce a face centered cubic (fcc), low magnetocrystalline phase and not the desired high anisotropy L10 phase. Thus the films must be subjected to post synthesis annealing to induce a phase transformation from fcc to L10.
Self-assembled arrays of FePt L10 nanoparticles can, in principle, reduce transition jitter by having uniformly sized magnetic grains separated by a well-defined matrix. Jitter is the noise in the magnetic signal from the media that arises from the poorly defined boundary of the magnetic bit formed by randomly shaped and randomly sized magnetic grains. Thus the ideal magnetic media would be formed of nanoparticles that are of uniform, small size, are packed into arrays with the highest possible density, and have uniform, e.g., perpendicular magnetic orientation.
Chemical syntheses have been developed that produce nearly spherical FePt nanoparticles that are highly monodispersed with uniform diameters of 3-4 nm. Various methods of chemical synthesis of FePt nanoparticles are known. These syntheses produce spherical nanoparticles coated with films of oleic acid and oleylamine surfactants that are ˜2 nm thick. One of the disadvantages of these small spherical nanoparticles is that they have low magnetic moment per unit area requiring very sensitive read heads to detect the recorded bits. A typical parameter used to describe the average signal from the media is the Mrt. Here Mr is the remanent magnetization and t is the thickness of the media. FIGS. 7 and 8 show calculations for the Mrt for spherical particles self-assembled on square and hexagonal lattices and cubes self-assembled on a square lattice. Taken into consideration is a region of 'nonmagnetic' material surrounding the particles with a thickness of 'a', which may represent surfactant, oxides, other nonmagnetic metals and/or space. The Mrt for all these structures are shown to be ˜kMrr3/R2 where Mr is the remanent magnetization and r and R are geometrically described in the figure. Notice that the constant k depends on the shape of the particles and the lattice in which they are placed. Here k=1.05 for spheres on a square lattice, k=1.21 for spheres on a hexagonal lattice, and k=2 for cubes on a square lattice. Clearly self-assembled spherical particles give relatively lower Mrt as compared to cubic particles with similar dimensions.
A more critical problem with spherical particles is the fact that the magnetic axes of the particles are difficult to align once deposited on a surface. Others have reported the fabrication of oriented FePt nanoparticles with high coercivity but these nanoparticles were fabricated by electron beam evaporation and grown epitaxially on MgO(001) and NaCl(001) surfaces. Increasing the packing fraction and obtaining alignment of the magnetic axis are both crucial for utilization of chemically synthesized FePt nanoparticles in high density recording media.
Synthesis of cubic nanoparticles has been reported in the literature for various metals and alloys, including monodispersed silver nanocubes with edge length of 55 nm, cubic PbTe nanoparticles, and cubic PbSe nanoparticles for use as quantum dots. The formation of core shell cubic FePt/Fe3O4 nanoparticles has been reported, but showed no net orientation or long range self-assembly of these nanoparticles when deposited on substrates. Chemical synthesis of cubic FePt nanoparticles was reported by H. Zeng et al. [J. Am. Chem. Soc. 126, 11458 (2004)].
Self-assembled magnetic nanoparticle arrays are described in U.S. Pat. No. 7,041,394 B2, the disclosure of which is hereby incorporated by reference.
It would be desirable to have a magnetic storage media that includes nanoparticles having uniformly oriented magnetic axes and long range self-assembly.

Method of producing self-assembled cubic FePt nanoparticles and apparatus using same


A method for block selection on a image of a table, the table including rows and columns defined by visible and non-visible grid lines and containing table cells, includes identifying super-cells that include one or more table cells, wherein super-cells are identified according to traced white areas surrounding table cells and bounded by visible grid lines, determining whether vertical and horizontal grid lines bounding each table cell are visible or non-visible, and determining whether vertical and horizontal grid lines bounding each super-cell are visible or non-visible.

1. Field of the Invention
The present invention relates to page segmentation systems for classifying regions of a document image. More particularly, the present invention relates to a block selection system for identifying and defining features within table images.
2. Incorporation by Reference
Commonly-assigned U.S. application Ser. No. 07/873,012, now U.S. Pat. No. 5,680,479, entitled "Method and Apparatus For Character Recognition", Ser. No. 08/171,720, now U.S. Pat. No. 5,583,072, entitled "Method and Apparatus For Selecting Text And/Or Non-Text Blocks In A Stored Document", Ser. No. 08/338,781, entitled "Page Analysis System" now U.S. Pat. No. 5,987,171, Ser. No. 08/514,252, entitled "Feature Extraction System", now U.S. Pat. No. 5,848,186, and Ser. No. 08/664,675, entitled "System For Extracting Attached Text", are herein incorporated as if set forth in full.
3. Description of the Related Art
Conventional page segmentation systems are applied to document images in order to identify data types contained within specific regions of the document images. This information can be used to extract data within a specific region and to determine a type of processing to be applied to the extracted data.
For a document containing a table image, a region of text, or table cell, located within the table image can be converted to ASCII characters using optical character recognition (OCR) processing and stored in an ASCII file along with information corresponding to the location of the table cell. However, conventional systems cannot accurately determine a row and column address corresponding to the table cell. Accordingly, the recognized ASCII characters cannot be reliably input to a spreadsheet based on row and column address data.
In addition, the data produced by conventional systems is often insufficient to adequately recreate the internal features of a bit-mapped table image. For example, the data does not reflect vertical and horizontal grid lines within an analyzed table image. As defined herein, vertical and horizontal grid lines define each row and column within a table, and can be either visible or non-visible. Therefore, although a conventional system can be used to create an ASCII version of a bitmapped table, the ASCII version does not include data representative of table grid lines. Accordingly, the stored data cannot be used to accurately recreate a bit-mapped version of grid lines within the table. Moreover, in a case that it is desired to edit text within a table cell, it is difficult to determine, based on information provided by conventional systems whether the edited text will intersect with a grid line and thereby violate row/column boundaries.
Consequently, what is needed is a system for accurately identifying and representing internal features of a bit-mapped table image, such as rows, columns, and table grid lines.


Prior to the production of microlenses (29) by the reactive ion etch technique, a pattern of notches (25) is formed in a second surface of a substrate (11) opposite a first surface on which the microlenses (29) are to be formed. Reactive ion etching of the first surface to produce the microlenses is sufficiently deep to reach the pattern of notches, thereby to separate the substrate. The array of notches may define, for example, an array of first areas (26) on the second surface, each area being surrounded by a notch. Photoresist elements (28) are then each located on an area of the first surface corresponding to a first area of the second surface, so that the separation separates the substrate into a plurality of segments (26) each containing only one of the microlenses (29). The notches can be made such that each of the segments (26) is cylindrical so that each of the microlenses formed from the substrate has a circular outer periphery.

The copending application of A. Y. Feldblum et al., Ser. No. 08/024,035, filed Mar. 1, 1993, now U.S. Pat. No. 5,286,338, Feb. 15, 1994 and the patent of Derkits, U.S. Pat. No. 5,079,130, granted Jan. 7, 1992, both hereby incorporated herein by reference, describe a method for making microlens arrays comprising the steps of forming an array of photoresist elements on a silica substrate, melting the elements to cause them to have curved or dome-shaped surfaces, and thereafter solidifying the elements. The photoresist elements and the substrate are then subjected to reactive ion etching, that is, etching by a reactive gas in which the reaction is enhanced by applied radio frequency power. The photoresist elements cause differential etching of the substrate such that, after all of the photoresist has been etched away, the dome shapes of the original photoresist elements are replicated in the silica substrate.
The application points out that the technique is useful for making arrays of microlenses which can be used as a unit, or from which individual or discrete lenses can be selected for use. If discrete lenses are to be made, the array must be cut by any of a variety of methods to separate the individual lenses. Mechanical sawing of the array may be impractical because it may produce microcracks in the lenses that could interfere with their function. Also, it is sometimes desirable, for optimizing optical characteristics, to produce individual microlenses each having a circular outer periphery, and making the required circular cuts can be difficult. The Feldblum et al. technique for making microlenses would be much more practical for making discrete microlenses if methods for separating an array into individual elements, especially circular elements, could be simplified.


A fading rate of a mobile terminal unit is estimated by a fading rate estimation unit and an optimum step constant is decided by a step constant determiner depending on the estimated fading rate. This step constant is fed back to a feedback data calculator, so that a reception level can be converged to an ideal level even under a fading environment and the like.

1. Field of the Invention
The present invention relates to a radio apparatus and a gain control method, and more particularly to a radio apparatus carrying out Automatic Gain Control (abbreviated as AGC hereinafter) for a signal from a mobile terminal unit in a mobile communication system, and a gain control method for adjusting a gain convergence rate of AGC in the radio apparatus.
2. Description of the Background Art
In a mobile communication system (for example, Personal Handyphone System, abbreviated as PHS hereinafter) which has been rapidly developed in recent years, an approach to extract a signal from a desired mobile terminal unit through adaptive array processing in a radio receiving system at a base station is proposed in communication between the base station and the mobile terminal unit.
The adaptive array processing is processing to remove an interference component and correctly extract a signal from a desired mobile terminal unit by calculating a weight vector consisting of a reception coefficient (weight) for each antenna at a base station based on a received signal from a mobile terminal unit, for adaptive control.
The adaptive array processing requires a plurality of spatially distributed antennas, that is, an array antenna. In an array antenna, for example, formed of two antennas, an array output signal Y(t) is expressed as follows:
Y(t)=W1X1(t)+W2X2(t)
where X1(t), X2(t) each represents a received signal at each antenna, and W1, W2 each represents a weight at each antenna.
The received signal at each antenna is expressed as follows:
X1(t)=H11S1(t)+H12S2(t)+n1(t)
X2(t)=H21S1(t)+H22S2(T)+n2(t)
where S1(t) represents a signal from a desired mobile terminal unit and S2(t) represents a signal from an interference-causing mobile terminal unit.
Here, H11 represents a propagation path property from the desired mobile terminal unit to antenna 1, and H12 represents a propagation path property from the interference-causing mobile terminal unit to antenna 1. H21 represents a propagation path property from the desired mobile terminal unit to antenna 2, and H22 represents a propagation path property from the interference-causing mobile terminal unit to antenna 2. In addition, n1(t) represents noise at a receiving system of antenna 1, and n2(t) represents noise at the system of antenna 2. The array output in this case is expressed as follows:                               Y                                (            t            )                          =                  xe2x80x83                                                            (                              W1H11                +                W2H21                            )                                                  S1                                            (                t                )                                              +                                                  xe2x80x83                                                            (                              W1H21                +                W2H22                            )                                                  S2                                            (                t                )                                              +                                                  xe2x80x83                                              W1n1                                      (              t              )                                +                                    W2n2                                            (                t                )                                      .
Here, it is assumed that the weight that satisfies the following equation can be calculated:
(W1H11+W2H21)=1
(W1H21+W2H22)=0.
Accordingly, the array output signal can be expressed as follows:
Y(t)=S1(t)+n(t)
where n(t)=W1n1(t)+W2n2(t).
Thus, the interference component can be removed and the signal can be received from the desired mobile terminal unit by calculating the appropriate weight through the adaptive array processing.
FIG. 11 is a functional block diagram functionally illustrating a radio apparatus that is provided for each antenna at a conventional base station carrying out the adaptive array processing using such a plurality of antennas and carries out AGC for a signal from a mobile terminal unit. FIG. 12 is a flow chart illustrating a gain control method for adjusting a gain convergence rate of AGC in such a radio apparatus.
First referring to FIG. 11, a signal received from an antenna 1 is amplified by an AGC amplifier 2, converted into an IQ signal formed of an In-phase component (I component) and Quadrature component (Q component) by a quadrature detector 3, and thereafter stored into memory 4.
IQ signal once stored in memory 4 is provided to a demodulation circuit 5. Demodulation circuit 5 also receives IQ signal from another antenna (not shown), performs the adaptive array processing as described above and demodulation processing and extracts the signal from each mobile terminal unit.
A reception level detection unit 6 obtains the reception level of the signal from IQ signal stored in memory 4. An amplitude value of IQ signal is calculated, for example, for eight symbols from 60th symbol of the received signal for each frame. The maximum amplitude value for these eight symbols is considered as the reception level for that frame.
A feedback data calculator 7 calculates feedback data that decides an amplitude ratio of AGC amplifier 2 in the next frame by the reception level obtained by reception level detection unit 6 and a step constant stored in memory 9. Here, when the reception level obtained by reception level detection unit 6 is represented by P_max, a prescribed ideal value is represented by P_ideal, and the step constant is represented by Step, the amount of change xcex94FB from feedback data at the time of receiving the previous frame to feedback data at the time of receiving the next frame can be calculated by the following equation:
xcex94FB=(P_maxxe2x88x92Pxe2x80x94ideal)/2Step.
When the value of the feedback data at the time of receiving the previous frame is represented by FB, feedback data FBxe2x80x2 at the time of receiving the next frame can be expressed as follows:
FBxe2x80x2=FBxe2x88x92xcex94FB.
The feedback data calculated by feedback data calculator 7 is once stored in memory 8. The stored feedback data is read in the next frame and provided to a gain control input of AGC amplifier 2 to be reflected in AGC at the time of receiving the next frame.
Referring to FIG. 12, the gain control method for adjusting the gain convergence rate of AGC in the radio apparatus shown in FIG. 11 will now be described. It is noted that the following process is implemented by a Digital Signal Processor (DSP) of the radio apparatus in a software manner.
At step S1, the signal from the mobile terminal unit is subjected to quadrature detection. Here, an RXIF signal that is an intermediate frequency signal received from the mobile terminal unit is converted to an RXIQ signal subjected to quadrature detection.
At step S2, such a symbol is set in that the reception level of the signal received from the mobile terminal unit starts to be detected. An example is herein shown where the reception level is detected from 60th symbol of the received signal.
At step S3, it is determined whether the present symbol is in a symbol period in which the reception level of the signal from the mobile terminal unit is detected. For example, when the reception level is detected in the 8-symbol period from the 60th symbol to the 67th symbol, if the symbol in which amplitude will be calculated from now on precedes the 68th symbol, a process of calculating the amplitude in that symbol will follow, and if not, a process of calculating the feedback data will follow.
At step S4, the amplitude in that symbol is calculated. The value of squared I component of IQ signal is added to the value of squared Q component of IQ signal. Here, in order to simplify the process, the square roots of the resulting sum is not obtained.
At step S5, it is determined whether or not amplitude A calculated at step S4 is greater than the maximum amplitude A_max stored until now.
At step S6, if it is determined that A is greater than A_max at step S5, A_max is replaced by A.
At step S7, the symbol in which the amplitude is calculated is shifted by one in ascending order.
At step S8, the amount of change of the feedback data is calculated from the maximum amplitude value of the amplitudes from the 60th symbol to 67th symbol and from a fixed step constant stored in the memory.
At step S9, the feedback data in the next frame is calculated and the calculated feedback data is reflected in AGC at the time of receiving the next frame.
In the adaptive array processing, weights are calculated such that the power of interference component is small when the signals received from a plurality of antennas are multiplied by respective weights to be synthesized. Specifically, the operation of multiplying the weight means that the amplitude and phase of the signal received from each antenna are adjusted appropriately. Therefore, if the amplitude and phase information of the received signal suffers an error due to waveform distortion and the like, the adaptive array processing cannot fully function.
On the other hand, as to the input/output characteristics of general amplifiers, output at a certain level causes saturation, thereby creating a non-linear region. Therefore, in a case where the feedback data is calculated based on the fixed step constant as described above, for example, if the reception level of the signal from the mobile terminal unit is largely fluctuated by the effects of a distance between the base station and the mobile terminal unit, any possible obstacle, fading, and the like, the amplifier (AGC amplifier 2) at the base station enters into this non-linear region, leading to distortion of the received waveform, thereby resulting in that the adaptive array processing cannot fully function.
It is therefore an object of the present invention to provide a radio apparatus and a gain control method allowing for an adaptive array processing without a non-linear operation of an amplifier even under an environment in which a reception level of a signal from a mobile terminal unit largely fluctuates due to the effects of a distance between a base station and the mobile terminal unit, any obstacle, fading, and the like.
In accordance with the present invention, a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes: a gain control feedback circuit performing AGC on the signal depending on a level of the signal; a fading rate estimation unit estimating a fading rate of the mobile terminal unit; and a step constant determiner determining an optimum step constant which decides a gain of the gain control feedback circuit depending on the fading rate estimated by the fading rate estimation unit. The gain control feedback circuit includes a feedback data calculator calculating feedback data which defines a gain of the gain control feedback circuit based on the signal level and the optimum step constant as determined by the step constant determiner.
Preferably, the fading rate estimation unit calculates a reception response vector of the signal from the mobile terminal unit and estimates a fading rate from a correlation value of the reception response vectors between frames.
More preferably, the step constant determiner decides an optimum step constant at the fading rate estimated by the fading rate estimation unit based on an association table of preliminarily obtained fading rates and step constants.
More preferably, the feedback data calculator calculates feedback data in a next frame by obtaining a value of difference between a value of the signal level and an ideal value, dividing the value of difference by a prescribed constant a number of times corresponding to the step constant, followed by multiplication by a prescribed coefficient, thereby calculating an amount of change in feedback data, and adding the amount of change to feedback data at the time of receiving a previous frame.
In accordance with another aspect of the present invention, a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes: a gain control feedback circuit performing AGC on the signal depending on a level of the signal; a received signal strength detection unit detecting a received signal strength of the signal from the mobile terminal unit, at an antenna end of the radio apparatus; a feedback data conversion unit carrying out conversion from the received signal strength detected by the received signal strength detection unit to optimum feedback data which decides a gain of the gain control feedback circuit based on an association table of preliminarily obtained received signal strengths and feedback data; and a feedback data switch unit selecting the optimum feedback data converted by the feedback data conversion unit as an initial value of feedback data of the gain control feedback circuit.
In accordance with a further aspect of the present invention, a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes a gain control feedback circuit performing AGC on the signal depending on a level of the signal. The gain control feedback circuit includes a first gain control circuit supplying first feedback data allowing the level of the signal to converge to an ideal value slowly, and a second gain control circuit supplying second feedback data allowing the level of the signal to converge to an ideal value fast. The radio apparatus further includes a received signal strength detection unit detecting a received signal strength of the signal from the mobile terminal unit, at an antenna end of the radio apparatus, and a feedback data switch unit selecting the first feedback data or the second feedback data depending on a detection result from the received signal strength detection unit.
Preferably, the feedback data switch unit makes a switch from the first feedback data to the second feedback data when fluctuation of the received signal strength detected by the received signal strength detection unit decreases to a prescribed threshold or below or increases to a prescribed threshold or above.
In accordance with yet another aspect of the present invention, a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes a gain control feedback circuit performing AGC on the signal depending on a level of the signal. The gain control feedback circuit includes a first gain control circuit supplying first feedback data allowing the level of the signal to converge to an ideal value slowly, and a second gain control circuit supplying second feedback data allowing the level of the signal to converge to an ideal value fast. The radio apparatus further includes a new terminal detector detecting whether a signal is received from a new mobile terminal unit, and a feedback data switch unit selecting the first feedback data or the second feedback data depending on a detection result from the new terminal detector.
Preferably, the new terminal detector includes a demodulation circuit demodulating a specific signal from a new mobile terminal unit and an error determiner determining whether an error exists in the signal demodulated by the demodulation circuit and if no error exists, determining that a signal is received from a new mobile terminal unit.
More preferably, the error determiner determines that a signal has been received from a new mobile terminal unit if a unique word error does not exist in the signal demodulated in the demodulation circuit.
More preferably, the error determiner determines that a signal has been received from a new mobile terminal unit if the number of bit errors in a preamble portion is equal to or smaller than a prescribed threshold in the signal demodulated in the demodulation circuit.
More preferably, the gain control feedback circuit includes a reception level detection unit detecting the level of the signal. The reception level detection unit calculates an amplitude value for each IQ signal during a prescribed period of a received signal and regards a maximum amplitude value among the amplitude values as a reception level of the received signal.
More preferably, the gain control feedback circuit includes a reception level detection unit detecting the level of the signal. The reception level detection unit calculates an amplitude value for each IF signal during a prescribed period of a received signal and regards a maximum amplitude value among the amplitude values as a reception level of the received signal.
In accordance with another aspect of the present invention, a gain control method in a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes the steps of: performing AGC on the signal depending on a level of the signal; estimating a fading rate of the mobile terminal unit; and determining an optimum step constant which decides a gain of AGC, depending on the estimated fading rate. The step of carrying out AGC includes the step of calculating feedback data which defines a gain of AGC, based on the signal level and the optimum step constant as determined.
Preferably, the step of estimating a fading rate includes the step of calculating a reception response vector of the signal from the mobile terminal unit and estimating a fading rate from a correlation value of the reception response vectors between frames.
More preferably, the step of determining an optimum step constant includes the step of deciding an optimum step constant at the estimated fading rate based on an association table of preliminary obtained fading rates and step constants.
More preferably, the step of calculating feedback data includes the step of calculating feedback data in a next frame by obtaining a value of difference between a value of the signal level and an ideal value, dividing the value of difference by a prescribed constant a number of times corresponding to the step constant, followed by multiplication by a prescribed coefficient, thereby calculating an amount of change of feedback data, and adding the amount of change to feedback data at the time of receiving a previous frame.
In accordance with a further aspect of the present invention, a gain control method in a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes the steps of: performing AGC on the signal depending on a level of the signal; detecting a received signal strength of the signal from the mobile terminal unit at an antenna end of the radio apparatus; carrying out conversion from the detected, received signal strength to optimum feedback data which decides a gain of AGC based on an association table of preliminarily obtained received signal strengths and feedback data; and selecting the converted optimum feedback data as an initial value of feedback data.
In accordance with yet another aspect of the present invention, a gain control method in a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes the step of performing AGC on the signal depending on a level of the signal. The step of performing AGC includes a first step of supplying first feedback data allowing the level of the signal to converge to an ideal value slowly, and a second step of supplying second feedback data allowing the level of the signal to converge to an ideal value fast. The method further includes the steps of detecting a received signal strength of the signal from the mobile terminal unit, at an antenna end of the radio apparatus, and selecting the first feedback data or the second feedback data depending on a detection result.
Preferably, the step of selecting feedback data includes the step of making a switch from the first feedback data to the second feedback data when fluctuation of the detected, received signal strength decreases to a prescribed threshold or below or increases to a prescribed threshold or above.
In accordance with a still further aspect of the present invention, a gain control method in a radio apparatus carrying out AGC for a signal from a mobile terminal unit includes the step of performing AGC on the signal depending on a level of the signal. The step of performing AGC includes a first step of supplying first feedback data allowing the level of the signal to converge to an ideal value slowly, and a second step of supplying second feedback data allowing the level of the signal to converge to an ideal value fast. The method further includes the steps of detecting whether a signal is received from a new mobile terminal unit, and selecting the first feedback data or the second feedback data depending on a detection result.
Preferably, the step of detecting a new mobile terminal unit includes the steps of demodulating a specific signal from a new mobile terminal unit, and determining whether an error exists in the demodulated signal and if no error exists, determining that a signal is received from a new mobile terminal unit.
More preferably, the step of determining whether an error exists includes the step of determining that a signal has been received from a new mobile terminal unit when a unique word error does not exist in the demodulated signal.
More preferably, the step of determining whether an error exists includes the step of determining that a signal has been received from a new mobile terminal unit if the number of bit errors in a preamble portion is equal to or smaller than a prescribed threshold in the demodulated signal.
More preferably, the step of performing AGC includes the step of detecting a level of the signal. The step of detecting a level of the signal includes the step of calculating an amplitude value for each IQ signal during a prescribed period of a received signal and regarding a maximum amplitude value among the amplitude values as a reception level of the received signal.
More preferably, the step of performing AGC includes the step of detecting a level of the signal. The step of detecting a level of the signal includes the step of calculating an amplitude value for each IF signal during a prescribed period of a received signal and regarding a maximum amplitude value among the amplitude values as a reception level of the received signal.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Radio apparatus carrying out automatic gain control and gain control method


A thermoelectric module includes a case, a insulating base plate for a exoergic side, a insulating base plate for endoergic side, a first soldering layer which joins the insulating base plate for the exoergic side to the case via a first soldering material, and a second soldering layer which joins P-type and N-type semiconductor tips to the insulating base plate for an exoenergic side and a insulating base plate for an endoergic side, using second soldering material. The melting point temperature of the first soldering material for the first soldering layer is higher than the melting point temperature of the second material for the second soldering layer.

The present application is based on Japanese patent application 2000-300017 filed on Sep. 29, 2000, which is hereby incorporated herein by reference, in its entirety.
1. Field of the Invention
The present invention relates to a thermoelectric module which may be an optical communication semiconductor laser diode module, a semiconductor amplifier module, an external electro-absorption modulator, a reception module, etc.
2. Discussion of the Background
The environmental setting of a thermoelectric semiconductor laser diode module, in other words the external ambiance of the laser diode module, can approach a temperature of 60xc2x0 to 70xc2x0 C. due to the generation ofjoule heat in the various electric parts. In a laser diode used as a light source in high speed optical fiber communication, when the ambient temperature changes, the optical characteristics also change, so that the wavelength of the laser diode changes. Therefore, a tip-carrier equipped with a laser diode is isolated thematically from the module case. In order to thermally isolate the laser diode and keep its temperature constant, a thermoelectric module having a controlled temperature is used in general.
The thermoelectric module with controlled temperature is made by joining the insulating body enclosing the electrodes and the semiconductor tips. When heating or cooling by using the thermoelectric module, the construction is joined to another member via further soldering material, such as shown in Japanese laid open publication patent tokkai-hei 10-62659.
For example, in the case of using the thermoelectric module for cooling, the soldering material used for joining the thermoelectric module to the physical object to be cooled or the construction body for exoergio (a heat sink or a box case etc.), has a lower melting point temperature (solidus, liquidus) than the soldering material joined the tips between the two insulations. The reason is to prevent deformation and destruction of the thermoelectric module when joining. Selection of soldering material is decided while making an allowance of a safety ratio in regard to the generation of over-shoot of the temperature of the heat process.
Furthermore, in the case where high heat resistance is required, as disclosed in pages 24 to 25 of xe2x80x9cThermoelectric Transfer System Technical General Handbookxe2x80x9d published by Realize Company, published Jun. 30, 1995, in general 95Sn5Sb solder is used because when the semiconductor tips are joined the heat resistance of the semiconductor adds to the heat resistance of soldering material.
However, as above-mentioned, the joining of the encasing body and the construction for heat release uses a soldering material having a lower melting point temperature (solidus, liquidus) than the soldering material joining the semiconductor tips. Therefore, when high heat resistance is required, there is the problem that the heat resistance and the reliability of the joint of the insulating body and the construction for heat release deteriorates.
Furthermore, in regard to using 95Sn5Sb solder for joining tips, when we select soldering material for joining the insulating body for exoergic side (heat release side) to the semiconductor tips and we select solder material having a high heat resistance with a lower melting point than 95Sn5Sb solder, there is the problem that most soldering material includes Pb having an adverse environmental effect.
It is an object of the present invention to solve the above-mentioned disadvantages.
According to one feature of the present invention, a thermoelectric module comprises a case, P-type and N-type semiconductor tips having an exoergic side and an endoergic side, said P-type and N-type semiconductor tips being positioned in said case, an insulating base plate for the exoergic side positioned in said case, an insulating base plate for the endoergic side positioned in said case, a first soldering layer which joins the insulating base plate for the exoergic side to said case via first soldering material, and second soldering layers which respectively join the P-type and N-type semiconductor tips to the insulating base plate for the exoergic side and the insulating base plate for the endoergic side using a second soldering material, wherein a melting point temperature of first soldering material for the first soldering layer is higher than a melting point temperature of the second material for the second soldering layers.
Therefore, the thermoelectric module according to the present invention can have high heat resistance for the soldering material at the exoergic side, even though solder such as 95Sn5Sb solder is used.
According to another feature of the present invention, a process for producing a thermoelectric module including P-type and N-type semiconductor tips having an exoergic side and an endoergic side, comprises a first step of joining a case to an insulating base plate via a first soldering layer of a first soldering material, a second step of joining an insulating base plate for the endoergic side to the P-type and N-type semiconductor tips via a second soldering layer of a second soldering material, and third step of joining an insulating base plate for the exoergic side to the P-type and N-type semiconductor tips via a second soldering layer of the second soldering material, wherein a melting point temperature of first soldering material for the first soldering layer is higher than the melting point temperature of second material for the second soldering layers.
Therefore, the thermoelectric module can be prevented from deformation and destruction.
Furthermore, according to the present invention, the semiconductor tips do not produce heat when joining the insulating base plate for the exoergic side, so that we can use soldering material which needs heat more than 300xc2x0 C., that could not be used heretofore in relation with heat resistance of the tips at soldering. Furthermore, we need not use solder material comprising Pb.

Thermoelectric module and process for producing thermoelectric module


The present invention discloses a semiconductor device, comprising: a substrate, an insulating isolation layer formed on the substrate, a first active region layer and a second active region layer formed in the insulating isolation layer, characterized in that the carrier mobility of the first active region layer and/or second active region layer is higher than that of the substrate. In accordance with the semiconductor device and the manufacturing method thereof in the present invention, an active region formed of a material different from that of the substrate is used, the carrier mobility in the channel region is enhanced, thereby the device response speed is substantially improved and the device performance is enhanced greatly. Furthermore, unlike the existing STI manufacturing process, for the present invention, an STI is formed first, and then filling is performed to form an active region, thus avoiding the problem of generation of holes in STI, and improving the device reliability.

With the continuous reduction in size of a semiconductor device, enhancing the carrier mobility of channel becomes a very important technique. In the design of a stress layer of a substrate, different materials have different characteristics such as lattice constant, dielectric constant, forbidden gap, particularly carrier mobility, etc., as shown in Table 1 below.
TABLE 1LatticeDielectricForbidden Mobility (cm2/V-s)Materialconstant (nm)constantgap(eV)electronholeSi0.543111.81.121600430Ge0.5675160.6639001900GaAs0.565312.41.429200400InAs0.605814.80.3640000500InSb0.64817.70.1777000850
It can be seen from Table 1 that among the above possible materials for substrate, Ge has the highest hole mobility and a relatively higher electron mobility, thus can make the performance of the PMOS taking it as the channel region best and the performance of the NMOS good. Using Ge as the substrate of a semiconductor device will greatly enhance the carrier mobility, thus enabling manufacture of a higher-speed large scale integrated circuit (LSIC). Similarly, using InSb as the channel of NMOS can maximum the performance of the NMOS, meanwhile the performance of PMOS of InSb is also good.
Further, it can also be seen from Table 1 that materials Ge and GaAs have a similar lattice constant as that of the material Si, thus they can be easily integrated on a Si substrate commonly used in the semiconductor technology, such that a semiconductor device with better performance can be manufactured by the technology without making great improvements thereto, thereby improving the performance while reducing the cost at the same time. However, certain disparity exists between the lattice constant of InAs and InSb and that of the material Si, a transition layer or a buffer layer, which may be made of GaAs and GaN etc. with a lattice constant similar to that of Si shall be added when materials of InAs and InSb are used.
In the design of a semiconductor device and an integrated circuit thereof, generally a shallow trench isolation (STI) is used to manufacture the insulating isolation among a plurality of devices in the substrate. The known method for manufacturing a STI comprises first etching a trench in the substrate, then depositing an insulating film made of e.g., an oxide in the formed trench by a process such as chemical vapor deposition (CVD). With reduction in the device size, the aspect ratio of corresponding STI becomes larger continuously and the step coverage of the oxide insulating film becomes poorer, that is, the oxide insulating film on top of the narrower trench may join earlier while the trench below is not completely filled, thus holes or gaps may exist in the STI, resulting in that the insulating property of the device deteriorates and reliability thereof becomes worse.
Overall, the existing semiconductor device with Si channel surrounded by STI has poor performance and reliability, the carrier mobility in the channel region shall be further improved and holes in STI shall be removed to improve the electrical performance and reliability of the semiconductor device.

Semiconductor device and method of manufacturing the same


An organic light-emitting diode includes: a substrate; a first electrode; a second electrode; an emission layer between the first electrode and the second electrode; and a hole blocking layer between the emission layer and the second electrode. The hole blocking layer includes a first layer including a first material and a second material, and a second layer formed on the first layer and including the first material. The first material includes a hole blocking material having a highest occupied molecular orbital (HOMO) energy level in the range of about 5.5 to about 6.9 eV, and the second material includes a green or red phosphorescent host material.

1. Technical Field
The present invention relates to an organic light-emitting diode including a multi-layered electron transport layer and a flat display device including the same.
2. Description of Related Art
Organic light-emitting diodes (OLEDs) are self-emitting devices, and have advantages such as a wide viewing angle, good contrast, quick response times, high brightness, and good driving voltage characteristics. Also OLEDs can provide multicolored images.
In general, an OLED has a structure including a substrate, and an anode, a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and a cathode are sequentially stacked on the substrate. In this regard, the HTL, the EML, and the ETL are organic layers formed of organic compounds. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the EML via the HTL, and electrons injected from the cathode move to the EML via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from the excited state to the ground state, light is emitted.
When the EML of the OLED includes a phosphorescent dopant, a hole blocking layer (HBL) may be formed on the EML to prevent triplet excitons or holes from being diffused into the ETL. The HBL is formed of a hole blocking material, and prevents holes from being diffused into the ETL, thereby enhancing the efficiency of the OLED. However, the driving voltage and lifetime of the OLED may be reduced.

Organic light-emitting diode and flat display device including the same


A system and method for stereoscopically imaging a patient at multiple locations in a radiation treatment system with a variable imaging geometry to enable the delivery of radiation treatments from multiple ranges of treatment angles without obstructing the imaging system or the radiation treatment.

Radiosurgery and radiotherapy are radiation treatment systems that use external radiation beams to treat pathological anatomies (e.g., tumors, lesions, vascular malformations, nerve disorders, etc.) by delivering a prescribed dose of radiation (e.g., X-rays or gamma rays) to the pathological anatomy while minimizing radiation exposure to surrounding tissue and critical anatomical structures (e.g., the spinal chord). Both radiosurgery and radiotherapy are designed to necrotize pathological anatomy while sparing healthy tissue and the critical structures. Radiotherapy is characterized by a low radiation dose per treatment and many treatments (e.g., 30 to 45 days of treatment). Radiosurgery is characterized by a relatively high radiation dose in one, or at most a few, treatments. In both radiotherapy and radiosurgery, the radiation dose is delivered to the site of the pathological anatomy from multiple angles. As the angle of each radiation beam is different, each beam intersects a target region occupied by the pathological anatomy, but passes through different areas of healthy tissue on its way to and from the target region. As a result, the cumulative radiation dose in the target region is high and the average radiation dose to healthy tissue and critical structures is low.
Frame-based radiotherapy and radiosurgery treatment systems employ a rigid, invasive stereotactic frame to immobilize a patient during pre-treatment imaging for diagnosis and treatment-planning (e.g., using a CT scan or other 3-D imaging modality, such as MRI or PET), and also during subsequent radiation treatments. These systems are limited to intracranial treatments because the rigid frame must be attached to bony structures that have a fixed spatial relationship with target region, and the skull and brain are the only anatomical features that satisfy that criterion.
In one type of frame-based radiosurgery system, a distributed radiation source (e.g., a cobalt 60 gamma ray source) is used to produce an approximately hemispherical distribution of simultaneous radiation beams though holes in a beam-forming assembly. The axes of the radiation beams are angled to intersect at a single point (treatment isocenter) and the beams together form an approximately spherical locus of high intensity radiation. The distributed radiation source requires heavy shielding, and as a result the equipment is heavy and immobile. Therefore, the system is limited to a single treatment isocenter.
In another type of frame-based radiotherapy system, known as intensity modulated radiation therapy (IMRT), the radiation treatment source is an x-ray beam device (e.g., a linear accelerator) mounted in a gantry structure that rotates around the patient in a fixed plane of rotation. IMRT refers to the ability to shape the cross-sectional intensity of the radiation beam as it is moved around the patient, using multi-leaf collimators (to block portions of the beam) or compensator blocks (to attenuate portions of the beam). The axis of each beam intersects the center of rotation (the treatment isocenter) to deliver a dose distribution to the target region. Because the center of rotation of the gantry does not move, this type of system is also limited to a single treatment isocenter.
Image-guided radiotherapy and radiosurgery systems (together, image-guided radiation treatment (IGRT) systems) eliminate the need for invasive frame fixation by tracking changes in patient position between the pre-treatment imaging phase and the treatment delivery phase (in-treatment phase). This correction is accomplished by acquiring real-time stereoscopic X-ray images during the treatment delivery phase and registering them with reference images, known as digitally reconstructed radiograms (DRRs), rendered from a pre-treatment CAT scan. A DRR is a synthetic X-ray produced by combining data from CAT scan slices and computing a two-dimensional (2-D) projection through the slices that approximates the geometry of the real-time imaging system.
Gantry-based IGRT systems add an imaging x-ray source and a detector to the treatment system, located in the rotational plane of the LINAC (offset from the LINAC, e.g., by 90 degrees), and which rotate with the LINAC. The imaging x-ray beam passes through the same isocenter as the treatment beam, so the imaging isocenter coincides with the treatment isocenter, and both isocenters are fixed in space.
FIG. 1 illustrates the configuration of an image-guided, robotic-based radiation treatment system 100, such as the CyberKnife® Radiosurgery System manufactured by Accuray, Inc. of California. In this system, the trajectories of the treatment x-ray beams are independent of the location of the imaging x-ray beams. In FIG. 1, the radiation treatment source is a LINAC 101 mounted on the end of a robotic arm 102 having multiple (e.g., 5 or more) degrees of freedom in order to position the LINAC 101 to irradiate a pathological anatomy (target region or volume) with beams delivered from many angles, in many planes, in an operating volume around the patient. Treatment may involve beam paths with a single isocenter, multiple isocenters, or with a non-isocentric approach (i.e., the beams need only intersect with the pathological target volume and do not necessarily converge on a single point, or isocenter, within the target).
In FIG. 1, the imaging system includes X-ray sources 103A and 103B and X-ray detectors (imagers) 104A and 104B. Typically, the two x-ray sources 103A and 103B are mounted in fixed positions on the ceiling of an operating room and are aligned to project imaging x-ray beams from two different angular positions (e.g., separated by 90 degrees) to intersect at a machine isocenter 105 (where the patient will be located during treatment on a treatment couch 106) and to illuminate imaging surfaces (e.g., amorphous silicon detectors) of respective detectors 104A and 104B after passing through the patient. FIG. 2 illustrates the geometry of radiation treatment system 100. Typically, the x-ray detectors 104A and 104B are mounted on the floor 109 of the operating room at ninety degrees relative to each other and perpendicular to the axes 107A and 107B of their respective imaging x-ray beams. This orthogonal, stereoscopic imaging geometry is capable of great precision, reducing registration errors to sub-millimeter levels. However, there are some inherent limitations associated with this imaging geometry when installed in a typical operating room, which may have a ceiling no more than nine or ten feet high.
As illustrated in FIG. 2, the LINAC 101 is highly maneuverable and relatively compact, but it still requires a minimum amount of separation between the patient 108 and the ceiling 110 of the operating room to deliver treatments from above the patient. There are also certain positions that the LINAC may be unable to occupy, either because the LINAC may block one of the imaging x-ray beams or because one of the x-ray detectors may block the radiation treatment beam. Furthermore, because the patient must be located at least some minimum distance from the ceiling to enable access from above, there may be insufficient room below the patient to deliver treatment from below, even if treatment from under the patient would be more beneficial (e.g., treating the spinal area while the patient is laying face up). Therefore, the location of the imaging center of the imaging system may need to be chosen as a compromise between treatment access and imaging access.

Imaging geometry for image-guided radiosurgery


A system and method of cracking hydrocarbon feedstocks is provided that allows for significant flexibility in terms of the desired product yield. An integrated process includes introducing the feedstock and hydrogen into a first hydrocracking reaction zone containing a first hydrocracking catalyst to produce a first zone effluent. The first zone effluent and optionally additional hydrogen are passed to a second hydrocracking reaction zone containing a second hydrocracking catalyst to produce a second zone effluent. The second zone effluent is conveyed to a fractionating zone to at least a low boiling fraction and a high boiling fraction, and optionally one or more intermediate fractions. The bottoms fraction is passed to a fluidized catalytic cracking reaction and separation zone, from which olefins and gasoline are recovered. At least a portion of remaining cycle oil is passed from the fluidized catalytic cracking reaction and separation zone to the first and/or second hydrocracking reaction zone.

1. Field of the Invention
The present invention relates to integrated cracking systems and processes that combine hydrocracking and fluidized catalytic cracking operations, in particular for enhanced flexibility in the production of light olefinic and middle distillate products.
2. Description of Related Art
Hydrocracking processes are used commercially in a large number of petroleum refineries. They are used to process a variety of feeds boiling in the range of 370° C. to 520° C. in conventional hydrocracking units and boiling at 520° C. and above in the residue hydrocracking units. In general, hydrocracking processes split the molecules of the feed into smaller, i.e., lighter, molecules having higher average volatility and economic value. Additionally, hydrocracking processes typically improve the quality of the hydrocarbon feedstock by increasing the hydrogen to carbon ratio and by removing organosulfur and organonitrogen compounds. The significant economic benefit derived from hydrocracking operations has resulted in substantial development of process improvements and more active catalysts.
Mild hydrocracking or single stage once-through hydrocracking occurs at operating conditions that are more severe than hydrotreating processes, and less severe than conventional full pressure hydrocracking processes. This hydrocracking process is more cost effective, but typically results in lower product yields and quality. The mild hydrocracking process produces less mid-distillate products of a relatively lower quality as compared to conventional hydrocracking. Single or multiple catalysts systems can be used depending upon the feedstock processed and product specifications. Single stage hydrocracking is the simplest of the various configurations, and is typically designed to maximize mid-distillate yield over a single or dual catalyst systems. Dual catalyst systems can be deployed as a stacked-bed configuration or in multiple reactors.
In a series-flow configuration the entire hydrotreated/hydrocracked product stream from the first reactor, including light gases (e.g., C1-C4, H2S, NH3) and all remaining hydrocarbons, are sent to the second reactor. In two-stage configurations the feedstock is refined by passing it over a hydrotreating catalyst bed in the first reactor. The effluents are passed to a fractionator column to separate the light gases, naphtha and diesel products boiling in the temperature range of 36° C. to 370° C. The hydrocarbons boiling above 370° C. are then passed to the second reactor for additional cracking.
In fluidized catalytic cracking (FCC) processes, petroleum derived hydrocarbons are catalytically cracked with an acidic catalyst maintained in a fluidized state, which is regenerated on a continuous basis. The main product from such processes has generally been gasoline. Other products are also produced in smaller quantities via FCC processes such as liquid petroleum gas and cracked gas oil. Coke deposited on the catalyst is burned off at high temperatures and in the presence of air prior to recycling regenerated catalyst back to the reaction zone.
In recent years there has been a tendency to produce, in addition to gasoline, light olefins by FCC operations, which are valuable raw materials for various chemical processes. These operations have significant economic advantages, particularly with respect to oil refineries that are highly integrated with petrochemical production facilities.
There are different methods to produce light olefins by FCC operations. Certain FCC operations are based on a short contact time of the feedstock with the catalyst, e.g., as disclosed in U.S. Pat. Nos. 4,419,221, 3,074,878, and 5,462,652, which are incorporated by reference herein. However, the short contact time between feedstock and catalyst typically results in relatively low feed conversion.
Other FCC operations are based on using pentasil-type zeolite, for instance, as disclosed in U.S. Pat. No. 5,326,465, which is incorporated by reference herein. However, the use of a pentasil-type zeolite catalyst will only enhance the yield of light fraction hydrocarbons by excessive cracking of the gasoline fraction, which is also a high value product.
Additional FCC processes are based on carrying out the cracking reactions at high temperature, such as that disclosed in U.S. Pat. No. 4,980,053, which is incorporated by reference herein. However, this method can result in relatively high levels of dry gases production.
Further FCC operations are based on cracking the feed oil at high temperature and short contact time and using a catalyst mixture of specific base cracking catalyst and an additive containing a shape-selective zeolite, as disclosed in U.S. Pat. No. 6,656,346, which is incorporated by reference herein. Processes based on this method are also known as High Severity Fluidized Catalytic Cracking (HS-FCC). Features of this process include a downflow reactor, high reaction temperature, short contact time, and high catalyst to oil ratio.
Downflow reactors permit higher catalyst to oil ratio, since lifting of solid catalyst particles by vaporized feed is not required, and this is particularly suitable for HS-FCC. In addition, HS-FCC processes are operated under considerably higher reaction temperatures (550° C. to 650° C.) as compared to conventional FCC processes. Under these reaction temperatures, two competing cracking reactions occur, thermal cracking and catalytic cracking. Thermal cracking contributes to the formation of lighter products, such as dry gas and coke, whereas catalytic cracking increases propylene and butylene yield. The short residence time in the downflow reactor is also favorable to minimize thermal cracking. Undesirable secondary reactions such as hydrogen-transfer reactions, which consume olefins, are suppressed. The desired short residence time is attained by mixing and dispersing catalyst particles and feed at the reactor inlet followed by immediate separation at the reactor outlet. In order to compensate for the decrease in conversion due to the short contact time, the HS-FCC process is operated at relatively high catalysts to oil ratio.
While individual and discrete hydrocracking and FCC processes are well developed and suitable for their intended purposes, there nonetheless remains a need for increased flexibility, efficiency and high-value product yield in refinery operations.

Cracking system and process integrating hydrocracking and fluidized catalytic cracking


In a method for stretching plastic involving a stretching device incorporated into a stretch wrap machine for producing stretched plastic for wrapping a load, means are provided for stretching a sheet of stretchable plastic material at an angle across one or more stretching devices. The method comprises stretching the plastic over a plurality of generatrices in substantially parallel arrangement, moving the generatrices in an eccentric path about a central axis, and moving the generatrices in the axial directions, in staggered coordination. The movement of the generatrices imparts a biaxial stretch pattern upon the plastic and produces a neck down pattern.

1. Field of Invention
The present invention relates to automated methods and apparatus for producing biaxially stretched plastic material and more particularly to automated wrapping processes.
2. Description of Prior Art
Plastic is commonly used to form protective wraps. For example, objects being stored, shipped or distributed may require protection from handling, the environment, etc. Also, multiple unit products may require a wrap to secure them into a single, more manageable load.
There are primarily two kinds of plastic wraps. "Heat shrink" wraps are formed by wrapping a load and then subjecting the wrap to an elevated temperature. This causes the plastic to contract and bind the load. The drawbacks of heat-shrink wraps are well known. The heated plastic becomes rigid, and if the load settles, the wrap fails to exert a compressive force.
The second kind of plastic wrap is a "stretch wrap." This involves wrapping an object in stretched plastic so that as the plastic contracts, it binds the load. Because the stretched plastic is not rigid, it continues to exert a compressive force even if the load settles.
However, stretch wrap was not without its compromises. In contrast to heat shrink wrap, which contracts along its length and width, or biaxially, stretch wrap contracts only in the direction it is previously stretched. Because simultaneously stretching in biaxial directions has proven to be a formitable mechanical engineering problem, stretch wrap, and the devices and methods for producing it, generally stretch only along the length of the material.
There are primarily two kinds of commercially available plastic stretch wrapping machines: rotary machines and pass-through machines. Rotary machines rotate either a load or a dispenser to wind plastic material around the load. Pass-through machines move the load into a suspended, "U"-shaped curtain of plastic material and seal the ends of the pocket behind the load. The plastic material may be stretchable material, mesh, netting or the equivalent.
These machines generally use techniques for stretching the plastic that fall into two categories. The first category is known as "braking systems." In rotary machines, these systems generally involve withdrawing a material of stretchable plastic from a roll so as to wrap a rotating load. As the load rotates, and the plastic material wraps around it, a brake is applied to the roll, causing the plastic to stretch. Other braking systems revolve the roll around the load to achieve similar results.
Pass-through machines incorporate a braking system by pushing the load into a taut plastic curtain suspended between two rolls of plastic. By braking the unwinding of one or two rolls while moving the object through the curtain, the plastic is stretched around the front and sides of the load. Sealing devices close behind the load to form a complete wrap.
Braking systems stretch the material as it winds around the load. The stretching produces a reduction in the width of the material, which is known as "neck-down." These systems suffer a number of drawbacks. Uneven stretching caused by corners, edges and protrusions tend to cause the plastic to rupture. To compensate, the amount of stretch is typically reduced, thereby resulting in a looser wrap. Further, because the stretching is substantially along the length of the material, the wrap does not exert a compression force along the width of the material.
To alleviate some of these problems, a second category of systems was developed: pre-stretch systems. This type of system is described, for example, in French Patent No. 2,281,275. This system has proven to be a generally acceptable system for producing plastic wrap which will exert a force along the length of the material. Because the force necessary to stretch the plastic is greater than the force necessary to oppose its subsequent contraction, pre-stretching the material reduces the rupturing problems caused by protrusions, edges, etc.
Roller pre-stretch systems operate by passing plastic material along a series of rollers which are rotated so that the downstream rollers rotate faster than the upstream rollers. The extent to which the plastic is stretched between the series of rollers depends upon the difference in rotational speeds of the rollers. may rotate at equal speeds but the downstream roller has a greater circumference than the upstream roller. The stretched plastic is then used to form a wrap in either the rotary or pass-through manner Some roller pre-stretch machines also wrap the load faster than the pre-stretched plastic is dispensed, so as to further stretch the material as it is being applied to the load. In systems which combine prestretch and braking systems, the material neck-down occurs in two places; between the rollers themselves and between the rollers and the load.
Pass-through pre-stretch systems, unlike braking systems which force the object into the material curtain, operate by extending the pair of rollers through a taut plastic curtain. The movement of these rollers forms a "U-shaped" pocket of pre-stretched plastic material into which the object is moved. Sealing devices join the material ends behind the object.
A common feature of the above described machines and systems is unidirectional stretching, i.e., stretching the material along its length. While pre-stretching does reduce rupturing problems and provides more attractive, tighter packages as discussed above, the contraction in such wraps is along the axis of stretch. Because, consumers requiring biaxial contraction in a plastic wrap must currently accept the limitations of heat shrink plastic, it would be advantageous to provide a convenient method and apparatus for producing a plastic sheet that is stretched in two directions: its length and its width. Such biaxially stretched plastic would contract more uniformly around wrapped objects and particularly irregularly shaped objects. Further, uniform neck-down has no areas of extra "give" to compensate for protrusions, corners and edges. Thus, in addition to the above considerations, it would also be advantageous to have non-uniform neck-down.
Accordingly, it is an object of the present invention to provide an apparatus for producing biaxially stretched plastic material and an method for using that apparatus.
It is another object of the present invention to produce a wrap formed of biaxially stretched plastic material.
It is yet another object of the present invention to provide a biaxially stretched plastic material that does not have a uniform neck-down, which provides areas of extra "give."
Other objects of this invention will be apparent to those skilled in the art from the problems which this invention solves.

Method of wrapping a load with stretchable plastic material


The present invention relates to a method for producing multitone image data from data representative of an original image and, in particular, for producing multitone image data with a set of N output darkness levels U greater than 2 from original darkness values V.sub.o representative of an original image.

1. Field of the Invention
This invention relates to a method for producing multitone image data from data representative of an original image and, in particular, for producing multitone image data with a set of N output darkness levels U greater than 2 from original darkness values V.sub.o representative of an original image. An alternative approach is described in a commonly assigned application to Michael Speciner, Ser. No. 07/810,462, now allowed.
2. Description of Related Art
Any photograph, painting, etc., consisting of a broad range of tones or gradation of tones is known as a continuous tone image or picture. In paintings, changing the pigment concentration or the amount of deposit of the printing media on a substrate modulates the color values throughout an entire picture. In photography, the different tones are created by varying amounts of silver, which appears black, in image areas.
In most forms of printing, tones cannot be reproduced by varying concentrations or amounts of ink. Many printing processes can print only a solid density of a color in an image area, while no ink prints in a non image area. In order to reproduce the varying tones of a continuous tone original image, a halftone process can be used to convert the original image into a pattern of very small and clearly defined dots. More specifically, the original image can be scanned with a light beam using an image scanner to obtain an electronic signal containing image information in the form of intensity levels or optical density variations corresponding to elemental picture areas, known as pixels, of the original picture. Then a thresholding technique can be used to generate data or an output that can cause a dot to be printed in a pixel of the halftone reproduction if the intensity level or optical density variation of the corresponding pixel in the original image exceeds a predetermined value. The output can be stored in a memory or used directly to drive a recorder, such as an exposing device, a printer or a computer display.
In halftoning processes, each dot in the reproduced image has the same tonal value or optical density. Various tones in the original are represented in the halftone image by a large number of evenly spaced dots which can have different sizes. Larger dots produce darker tones. Smaller dots or fewer dots make lighter tones. Halftones have the appearance of continuous tone images because of the limited resolving power of the human eye. When viewed at a normal reading distance, the individual dots blend into and appear like a "continuous" tone.
A rather different halftoning technique is based on the idea that there is an error associated with each halftone pixel which is the difference between its darkness value (which can only be reproduced by a printed dot or the absence of a printed dot) and the darkness value of the corresponding continuous tone original image pixel. If this error is distributed to neighboring pixels before the halftone thresholding is performed for them, the sum of the errors in a region can be minimized, thus faithfully reproducing the average darkness value in the region. The Floyd-Steinberg algorithm produces good halftone images using this technique. For further information on the Floyd-Steinberg algorithm, see "An Adaptive Algorithm for Spatial Grey Scale," by R. W. Floyd and L. Steinberg in SID 75 Digest, Society for Information Display, 1975, pages 36-37.
In the reproduction of color images, the original multicolored image is typically scanned through separate sets of colored filters to produce four separate image signals, corresponding to three primary colors and, possibly, black. The chosen primary colors for color printing are typically cyan, magenta and yellow. The chosen primary colors for a color computer display are typically red, green and blue. The separate signals are processed as described above. In other words, a color separation signal representative of a pattern of very small and clearly defined dots is generated for each of the colors where the dots in each of the patterns has the same tonal value or optical density throughout that pattern. Then the patterns for each color must be combined.
For instance, an exposing device may produce black and white film transparencies, corresponding to each of the cyan, magenta, yellow and black color separation signals, known as color separation transparencies or color separations for short. The color separations are used to make printing plates. The printing plates are mounted on a printing press to print, in registration, four overlapping single colored images to reconstruct the multicolored original.
The electronic output signals may also be used to directly drive a color printer or a computer display to produce a reconstructed multicolored image without ever producing actual color separations or printing plates.
It is desirable to provide a method for producing a multitone image using a set of at least 3 output darkness values (or levels) for at least one output color from data representative of an original image.


A radio frequency module includes: a module board including first and second principal surfaces; first and second power amplifiers on the first principal surface; external-connection terminals on the second principal surface; and first and second via conductors connecting the first and second principal surfaces. The first and second via conductors are spaced apart in the module board, one end of the first via conductor is connected to a first ground electrode of the first power amplifier, the other end of the first via conductor is connected to a first external-connection terminal, one end of the second via conductor is connected to a second ground electrode of the second power amplifier, the other end of the second via conductor is connected to a second external-connection terminal, and the first and second via conductors each penetrate through the module board in a direction normal to the first and second principal surfaces.

In mobile communication devices such as a mobile phone, the number of circuit elements included in radio frequency front-end circuits increases, particularly with developments in multiband technologies.
WO2012/33885 discloses a radio frequency module (electronic component module) in which electronic components included in a radio frequency front-end circuit are mounted on both surfaces of the circuit board. The electronic components mounted on the circuit board are covered with a sealing resin layer, and connection terminals (pad electrodes) for connection with a motherboard are disposed on a surface of the sealing resin layer.

This patent is subject to a terminal disclaimer.

Radio frequency module and communication device


A fabric is cut, sewn, and furnished with Velcro or other hook and loop fastener portions to become a cover to be removably positioned about a drive mechanism of a bicycle to protect this drive mechanism from the accumulation of dirt. A back elevational side of this fabric cover has spaced circular cuts with access cuts to these spaced circular cuts, thereby forming an access flap. These cuts accommodate the fitting of this back elevational side about both the rear axle and the pedal axle, and alongside the drive chain and the sprocket of a bicycle. After the fitting of this back elevational side about a rear axle and a pedal axle, Velcro fastener portions are used to keep the access cuts closed together when this cover is in use. A front side, which is continuous throughout, is thereafter secured to the back elevational side, where not previously initially sewn together to make this cover, by using components of Velcro fasteners. Preferably a Velcro strap is used to keep a rear bicycle wheel from rotating, as this Velcro strap of this cover is passed around a spoke of a bicycle wheel.

There has always been a need to try to keep the drive mechanisms of bicycles clean to prevent unnecessary wear otherwise caused by dirt that accumulates in these drive mechanisms. In 1894 Walter Biddles in his U.S. Pat. No. 531,254 illustrated and described his gear case which was essentially all metal and permanently mounted on a bicycle frame to cover the bicycle drive mechanisms. Then in 1897 William C. Humphrey in his U.S. Pat. No. 594,694 disclosed his dress and mud guard which also was essentially all metal and permanently mounted on a bicycle frame to the bicycle drive mechanism.
In 1976 Messrs. Weed and Mougel, in their U.S. Pat. No. 3,968,913, illustrated and described their protective fabric cover for an automobile mounted bicycle carrier. Their fabric cover completely covered the entire bicycle. Openings provided in the flexible fabric material of the cover cleared portions of the automobile bicycle carrier and also strap portions used to secure the bicycle to this carrier. This fabric cover had a top opening to receive the bicycle. A top flap secured subsequently by a Velcro fastener completed the protection of the entire bicycle from the ambient environment.
Later, in 1983, Joseph G. Profeta in his U.S. Pat. No. 4,378,883, disclosed his bicycle carrying case made of vacuum formed plastic resin material, originally available in sheets. Two complete formed sides were hinged together to completely cover a bicycle. Fasteners were used to keep the cover sides together. Openings were provided to receive hangers either mounted on vehicles or on dwellings, and to receive a person's hands, or shoulder straps. The interior of this complete case was padded. Another embodiment was made as a unitary overall member having an integral hinge between the sides.
These past permanent covers, for covering only the drive mechanism of bicycles, and the full covers of bicycles are recognized as serving their respective purposes very well. There remains a need, however, for a low cost, easily made, easily installed, easily removed, and readily cleaned, fabric cover to place over the drive mechanism of bicycles, when they are being transported on a vehicle or stored while awaiting the next bicycle trip, to keep the drive mechanism clean.

Fabric protective cover for a drive mechanism of a bicycle


Variable phase bit sampling implementations are disclosed which minimize requirements for downstream digital processing resynchronization in systems that incorporate adjustable bit phase sampling that utilize variable delay elements which can interrupt the clocking stream signal. A sampling device includes a sampling circuit operative to provide an output signal in response to a data signal, where the sampling circuit includes a data input and a clock input. A variable delay circuit provides an adjustable trigger signal to the clock input in response to a first delay control signal. A fixed delay circuit delays the output signal by a predetermined amount of time in response to at least one delay control signal. By implementing the sampling device, a system clock signal may be connected directly to a downstream digital processing circuit, thereby allowing any potentially corrupted clock stream from the variable delay element to be connected only to the data sampling device and to utilize a fixed delay section that can be programmatically inserted between the output of the sampling device and the input to the downstream digital processing device.

1. Field of the Invention
The present invention generally relates to systems that require variable phase bit sampling of data streams and, more particularly, to performance measuring of data bit streams where multiple variable phase sampling devices are required to simultaneously sample the same bit cell at possibly different phases and where synchronization successfully at one phase offset within the bit cell is used at other phase offsets within the bit cell.
2. Description of the Related Art
In recent years, data rates in communications systems have continued to grow at a fast pace and continues to push the physical limits of communications components. Such advances push the need for new performance measuring equipment that can quickly and effectively grade the capabilities of communications systems. Many of these large advances have made older methods obsolete in favor of newer, faster approaches; however, these new approaches require optimized solutions for older, less-considered problems in order to achieve required larger-system performance. Being able to make sampling phase changes without glitching downstream processing is one such problem.
Devices and technologies from SyntheSys Research, Inc. and others require many fast, short measurements of sampled bit data at various phase offsets within a data bit period window. Changing phase offset of bit sampling within a bit period is typically done by using a variable delay mechanism. This element of variable delay for very high performance measuring devices is configured in the clocking path to the sampling device. Variable delays are often placed in the clocking path rather than the data path because of data dependency found in variable delay technology that would distort the data waveform under test. By placing a single-frequency clock signal through the variable delay component, precise and clean delay is achieved. Variable delay technologies that interrupt the clocking signal passing through the variable delay element when delay setting changes are made, will output incomplete or partial clock signals which cause receiving devices that depend on defined bit clock windows or exactly the correct number of clock edges to errantly go into bad states.
Conventional devices that measure performance of data streams utilizing variable delay technology that disrupt the clocking stream are not impacted by the overhead added by the need to resynchronize when delay settings were changed because these devices were limited to making longer-term average bit error rate measurements. Measurements that took many seconds to perform could easily hide resynchronization processes that took a second. However, new measurement methods require that individual measurement periods last many times less than one second, which means that overhead for resynchronization could dominate the time of the measurement if resynchronization was always necessary after each sampling phase change.
There are several commercially available testing systems that characterize and validate the performance of a data signal from a device or communications subsystems using bit error rate measurement methods. These include bit error rate measuring instruments from Agilent Technologies, Anritsu, Advantest and SHF. In each of these systems, non-overlapping techniques are used to create various methods for changing the phase at which bit cells are sampled and performing bit error rate and other measurement techniques. However, these methods require either variable phase setting mechanisms that do not interrupt clocking signals or processing resynchronization at a penalizing rate. It is key to be able to create short and fast measurement intervals utilizing variable phase setting mechanisms that do disrupt clocks as they are cost effective, they implement large delay ranges at very high frequencies and support superior delay resolutions.
Furthermore, no known art exists for mechanisms that allow independently adjusting different phase offsets for two or more tightly synchronized sampling devices such that downstream digital processing elements could simultaneously use the sampling device results while being assured that synchronization had been maintained between the multiple channels during any sampling phase change.
Additionally, no known art exists for mechanisms that allow synchronization taken at one phase offset within the bit cell to be maintained and used after the sampling phase was changed to another phase offset within the bit cell by a variable delay mechanism that would interrupt the clocking signal.
What is needed is a device and method that allows for clocking interruptions that typically occur when making flexible setting of sampling clock phase in high-performance systems to not cause clocking interruptions in downstream processing of post bit-sampled data. Such an invention will enable that synchronization of this post bit-sampled data is not lost from one setting to the next or from one sampling device to the next as in parallel sampling architectures.

Variable phase bit sampling with minimized synchronization loss


Methods and related nodes are disclosed that can enable the control of the impact of SRS switching on carrier aggregation activation delays. In some aspects, the method comprises determining a need to perform a carrier aggregation (CA) activation procedure, determining a need to perform a sounding reference signal (SRS) switching procedure, extending a delay associated with the CA activation procedure in order to allow the UE to perform the SRS switching procedure, and performing the CA activation procedure within the extended delay.

Sounding Reference Signals
Sounding reference signals (SRS) are known signals that are transmitted by user equipments (UEs) to allow, for instance, the base station (e.g., eNB) to estimate different uplink channel properties. These estimates may be used for uplink scheduling and link adaptation but also for downlink multiple antenna transmission, especially in case of TDD where the uplink and downlink use the same frequencies. The SRS are shown in FIG. 1 and generally have a time duration of a single OFDM symbol.
SRS can be transmitted in the last symbol of a 1 ms uplink subframe, and for the case with TDD, the SRS can also be transmitted in the special slot UpPTS. The length of UpPTS can be configured to be one or two symbols. In FIG. 2, an example is given for TDD with 3 downlink (DL) subframes and 2 uplink (UL) subframe. Generally, within a 10 ms radio frame, up to eight symbols may be set aside for sounding reference signals (SRS).
The configuration of SRS symbols, such as SRS bandwidth, SRS frequency domain position, SRS hopping pattern, and SRS subframe configuration are set semi-statically as a part of RRC information element.
There are two types of SRS transmission in LTE UL: 1) periodic SRS transmissions, and 2) aperiodic SRS transmissions. Periodic SRS is transmitted at regular time instances as configured by means of RRC signaling. Aperiodic SRS is a one-shot transmission that is triggered by signaling in PDCCH.
There are two different configurations related to SRS:                Cell specific SRS configuration; and        UE specific configuration.
The cell specific configuration indicates what subframes may be used for SRS transmissions within the cell as illustrated in FIG. 2. The UE specific configuration indicates to the UE a pattern of subframes (among the subframes reserved for SRS transmission within the cell) and frequency domain resources to be used for SRS transmission of that specific UE. It also includes other parameters that the UE can use when transmitting the signal, such as frequency domain comb and cyclic shift.
This means that sounding reference signals from different UEs can be multiplexed in the time domain, by using UE-specific configurations such that the SRS of two UEs are transmitted in different subframes. Furthermore, within the same symbol, sounding reference signals can be multiplexed in the frequency domain. The set of subcarriers can be divided into two sets of subcarriers, or combs, with the even and odd subcarriers respectively in each such set. Additionally, UEs may have different bandwidths to get additional FDM (The comb enables frequency domain multiplexing, or FDM, of signals with different bandwidths and also overlapping). Additionally, code division multiplexing can be used. In such cases, different users can use exactly the same time and frequency domain resources by using different shifts of a basic base sequence.
SRS Carrier Based Switching
In LTE networks, there are many kinds of downlink heavy traffic, which typically leads to a larger number of aggregated downlink component carriers (CC) than the number of (aggregated) uplink CCs. For the existing UE categories, the typical carrier aggregation (CA) capable UEs only support one or two uplink CCs while up to 5 CCs can be aggregated in downlink.
Some of the TDD carriers with DL transmission for the UE will have no UL transmission including SRS, and channel reciprocity cannot be used for these carriers. Such situations may become more severe with CA enhancement of up to 32 CCs where a large portion of CCs are TDD. Allowing fast carrier switching to and between TDD UL carriers may be a solution to allow SRS transmission on these TDD carriers.
SRS based carrier switching is aiming to support SRS switching to and between TDD component carrier(s), where the component carriers available for SRS transmission correspond to the component carriers available for carrier aggregation of PDSCH, while the UE has fewer component carriers available for carrier aggregation of PUSCH.
SRS based carrier switching simply means that during certain time resources the UE does not transmit any signal on one carrier (e.g. F1) while it transmits SRS on another carrier (e.g. F2). For example, F1 and F2 can be PCell and SCell respectively, or both of them can be SCells.
CA-Related Interruptions in LTE
The current CA-related interruption requirements are specified in 36.133, 3GPP TS 36.133, V13.3.0, e.g., as below.
======<<<<<<TS 36.133>>>>>======
220.127.116.11 Interruptions at SCell Activation/Deactivation for Intra-Band CA
When an intra-band SCell is activated or deactivated as defined in [2] the UE is allowed an interruption of up to 5 subframes on PCell during the activation/deactivation delay defined in Section 7.7. This interruption is for both uplink and downlink of PCell.
184.108.40.206 Interruptions at SCell Activation/Deactivation for Inter-Band CA
When an inter-band SCell is activated or deactivated as defined in [2] the UE that requires interruption is allowed an interruption of up to 1 subframe on PCell during the activation/deactivation delay defined in Section 7.7. This interruption is for both uplink and downlink of PCell.
======<<<<<<TS 36.133>>>>>======
Similar interruptions may occur also due to SRS switching.
Multi-Carrier Serving Cell Setup or Release Procedure in LTE
A multi-carrier serving cell setup herein refers to a procedure which enables the network node to at least temporarily setup or release a secondary serving cell at the UE for multi-carrier operation, e.g., the use of an SCell in CA capable UE, PSCell in dual connectivity (DC), etc. Herein the serving cell setup or release procedure or command can perform any one or more of:                Configuration of SCell(s), also referred to as SCell addition;        De-configuration of SCell(s), also referred to as SCell release;        Activation of SCell(s);        Deactivation of SCell(s);        Configuration of PSCell in DC, also referred to as PSCell addition;        De-configuration of PSCell in DC, also referred to as PSCell release.
On the one hand, the configuration procedure (e.g. configuration of SCell, addition of PSCell, etc.) is used by the serving radio network node (e.g., eNB) to configure a multicarrier UE capable with one or more serving cells (SCells, PSCell, etc.). On the other hand, the de-configuration procedure is used by the serving radio network node (e.g., eNB) to de-configure or remove one or more already configured serving cells. The configuration or de-configuration procedure is also used to change the current multi-carrier configuration, e.g., for increasing or decreasing the number of SCells or for swapping the existing SCells with new ones.
The serving radio network node can activate one or more deactivated serving cells or deactivate one or more activated serving cells on the corresponding configured secondary carriers. The PCell is always activated. Therefore, SCell can be activated or deactivated.
SCell Activation Delay
In 3GPP TS 36.133, v14.1.0, SCell activation delay refers to the delay within which the UE shall be able to activate a deactivated SCell in E-UTRA carrier aggregation. According to this requirement, upon receiving SCell activation command in subframe n, the UE shall be capable to transmit valid CSI report and apply actions related to the activation command for the SCell being activated no later than in subframe n+24 for a known cell. And, for an unknown cell, upon receiving the SCell activation command in subframe n, the UE shall be capable to transmit valid CSI report and apply actions related to the activation command for the SCell being activated no later than in subframe n+34 provided the SCell can be successfully detected on the first attempt. Furthermore, while activating an SCell if any other SCell is activated, deactivated, configured or deconfigured by the UE then the UE shall meet the SCell activation delay requirements (Tactivate_total) according to the expression:
      T          activate                                      _                                      total        =            T              activate                                                  _                                                  basic              +          5      ×                        ∑                      i            =            1                                N            -            1                                                                              K          i
where:
Tactivate_total is the total time to activate a SCell and is expressed in subframes;
Tactivate_basic is the SCell activation delay without another cell activation/deactivation, etc.;
Ki (0≤Ki≤[3]) is the number of times the other ith SCell is activated, deactivated, configured or deconfigured while the SCell is being activated; and
N (2≤N≤4) is the maximum number of SCells supported by the UE.
The valid CSI is based on the UE measurement and corresponds to any CQI value specified in 3GPP TS 36.213, with the exception of CQI index=0 (out of range).
Furthermore, the PCell interruption shall not occur before subframe n+5 and not occur after subframe n+9 when PCell belongs to E-UTRA FDD. And the PCell interruption shall not occur before subframe n+5 and not occur after subframe n+11 when PCell belongs to E-UTRA TDD.
During SCell activation, the UE will typically perform the following actions:                decode the MAC CE containing the activation command and send back ACK (e.g. 4 ms in LTE);        perform all the internal steps needed to activate the SCell (these depend on implementation), one of which is to turn on the RF chain that will be processing the CC;        adjust the AGC (this step will depend on whether the cell is known or not, when the cell was last measured, etc.);        acquire the exact timing of the cell (this step also depends on whether the cell is known or unknown);        process an instance of radio signals based on which it should compute the CQI and report the CQI to the eNB (e.g., 4 ms in LTE).
PSCell Addition Delay
PSCell activation delay refers to the delay within which the UE shall be able to configure a PSCell in E-UTRA dual connectivity. According to 3GPP TS 36.133, upon receiving PSCell addition in subframe n, the UE shall be capable to transmit PRACH preamble towards PSCell no later than in subframe n+Tconfig_Pscell, where:Tconfig_PSCell=20 ms+Tactivation_time+50 ms+TPCell_DU+TPSCell_DU
Tactivation_time is the PSCell activation delay. If the PSCell is known, then Tactivation_time is 20 ms. If the PSCell is unknown, then Tactivation_time is 30 ms provided the PSCell can be successfully detected on the first attempt.
TPCell_DU is the delay uncertainty due to PCell PRACH preamble transmission. TPCell_DU is up to 20 ms if PSCell activation is interrupted by a PCell PRACH preamble transmission, otherwise it is 0.
TPSCell_DU is the delay uncertainty in acquiring the first available PRACH occasion in the PSCell. TPSCell_DU is up to 30 ms.

Controlling the impact of SRS switching on carrier aggregation activation-related delays