A process for producing a powder of perovskite-type double oxide comprises the steps of reacting water-soluble lead oxide and aqueous solution of alkaline metal in a reaction vessel, and precipitating lead group hydroxide; then adding a solution of Nb group, precipitating Nb group hydroxide, and reacting hydrothermally in the reaction vessel. As a result, according to the present invention, the process of manufacture is capable of producing fine particles of pure perovskite phase, which particles are excellent in homogeneity and the degree of sintering.

1. Field of the Invention
The present invention generally relates to a process for producing a powder of perovskite-type double oxide generally represented by the formula ABO.sub.3, particularly to a process for producing the powder which has not only high perovskite ratio, but also homogeneous component and fine particles, moreover, which is excellent in degree of sintering.
2. Description of the Relevant Art
The perovskite-type double oxide has been extensively used for functional ceramics; such as, piezoelectrics, dielectrics, semiconductor, and material for a sensor or the like. Recently, it is actively promoted to improve the function and to add a function newly, wherein a raw powder is required as a homogeneous component, of fine particles and the property of being sintered at low temperature or the like.
Up to now, a solid phase synthesis and coprecipitation method have been used as a process for producing the powder of perovskite-type double oxide.
A summary of these methods is as follows.
(a) Solid phase synthesis
This method includes the steps of weighting compounds of each raw ingredient, mixing, and calcining. Although this method is generally used, high temperature reaction causes evaporation of the lead ingredient and heterogeneous component. And it is difficult to obtain fine particles.
In a reaction system including Nb, it is difficult to obtain a pure perovskite phase through the usual way, and the perovskite phase is contaminated with a pyrochlore phase. Since the pyrochlore phase causes it to lose degree of sintering, and make the electric property of sintered compact worse, several methods of decreasing pyrochlore phase is proved.
For example, a process for producing Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 is reported by S. L. Swartz, T. R. Shrout et al. (Mater. Res. Bull. 17,1245 (1982)). According to this production process, the pure perovskite phase is obtained by means of two steps of calcining, as follows;
MgO+Nb.sub.2 O.sub.5 .fwdarw.MgNb.sub.2 O.sub.6 (calcining temperature is about 1000.degree. C.)
1/3MgNb.sub.2 O.sub.6 +PbO.fwdarw.Pb(Mg.sub.1/3 N.sub.2/3)O.sub.3 (calcining temperature is about 900.degree. C.)
Although, in the usual single step of calcining, repetition of calcining and pulverizing achieves an increase in the ratio of perovskite phase, it is difficult to obtain pure perovskite phase by means of this process. In any event, this method has still had subjects in terms of particle size and homogeneity of compound.
(b) Coprecipitation method
This method includes the steps of preparing mixed solution of each ingredient, obtaining precipitate by means of reaction of said mixed solution and alkaline solution, drying of said precipitation and calcining.
In this process, it is also difficult to obtain pure perovskite phase. Even though the powder of pure perovskite phase is obtained, its degree of sintering is not good, because secondary particles form in the step of precipitating, drying and sintering.
As is mentioned above, the powder of lead group perovskite double oxide containing Nb obtained by means of said method is not pure perovskite phase and is not good in the degree of sintering. Therefore, it has been required to improve the method.

Process for producing a powder of perovskite-type double oxide


An image coding apparatus provides a run-length encoding unit RLE1 that subjects quantized coefficients which are obtained by quantizing frequency components of an image signal to a variable length coding process by using a run value Run that indicates the number of successive zero coefficients and a level value Lev that indicates a value of a non-zero coefficient following the zero coefficients. The run-length encoding unit RLE1 includes a reordering unit Lreodr for reordering level values Lev; a variable length coder LVLC for coding reordered level values ROLev by using a code table that is selected according to the value of a quantization parameter QP; a reordering unit Rreodr for reordering run values Run from high frequency component of the quantized coefficients to low frequency component; and a variable length coder RVLC for coding reordered run values RORun by using a code table that is selected according to the number of already-processed run values.

In recent years, we have greeted the age of multimedia in which audio, video and other data are integrally handled, and conventional information media (i.e., means for transmitting information to persons), such as newspapers, magazines, televisions, radios, and telephones have been adopted as subjects of multimedia. Generally, "multimedia" means to represent not only characters but also diagrams, speeches and especially images simultaneously in relation with each other. In order to handle the conventional information media as the subjects of multimedia, it is essential to transform the information into digital format.
When the quantity of data processed by each information medium described above is estimated as the quantity of digital data, in the case of characters, the data quantity for each character is 1˜2 bytes. However, in the case of speech, the data quantity is 64 kbits per second (quality for telecommunication) and, in the case of moving pictures, it is more than 100 Mbits per second (quality for current television broadcasting). So, as for the information media described above, it is not practical to handle such massive data as it is in the digital format. For example, visual telephones have already been put to practical use by ISDN (Integrated Services Digital Network) having a transmission rate of 64 kbps˜1.5 Mbps, but it is impossible to transmit an output image of a television camera having a large quantity of data as it is by the ISDN.
So, data compression technologies are demanded. For example in the case of visual telephones, the moving picture compression technologies standardized as H.261 and H.263 by ITU-T (International Telecommunication Union-Telecommunication Sector) are employed. Further, according to the data compression technology based on MPEG-1, it is possible to record image data, together with audio data, in an ordinary music CD (compact disk).
Here, MPEG (Moving Picture Experts Group) is an international standard associated with digital compression for image signals of moving pictures. In MPEG-1, an image signal of a moving picture is compressed to 1.5 Mbps, i.e., data of a television signal is compressed to about 1/100. Since the transmission rate to which MPEG-1 is directed is mainly restricted to about 1.5 Mbps, MPEG-2 is standardized to meet the demands for higher image quality. In MPEG-2, an image signal of a moving picture is compressed to 2˜15 Mbps.
Under the existing circumstances, standardization of MPEG-4 having a higher compression rate has been realized by the working group for the standardization of MPEG-1 and MPEG-2 (ISO/IEC JTC1/SC29/WG11). MPEG-4 not only enables coding at a low bit rate with high efficiency but also realizes introduction of a strong error resistant technology that can reduce a subjective deterioration of image quality even when a transmission line error occurs. Further, ITU-T is developing standardization of H.26L as an image coding method of the next generation, and the latest coding method at this point of time is a method called "Test Model 8" (TML8).
FIG. 30 is a block diagram illustrating a conventional image coding apparatus.
This image coding apparatus 201a has a blocking unit Blk for blocking an inputted image signal Vin into unit areas (blocks) each comprising a predetermined number of pixels and outputting a blocked image signal BlkS, and a frequency transformation unit Trans for subjecting the output BlkS to frequency transformation to output frequency components TransS corresponding to respective blocks. Here, the block is an area of a predetermined size in a picture (image space), which is a unit for a coding process of an image signal, and it is composed of a predetermined number of pixels. Here, the image signal Vin corresponds to a moving image that is composed of plural pictures.
The image coding apparatus 201a further includes a quantization unit Q for quantizing the outputs (frequency components) TransS from the frequency transformation unit and outputting quantized components (quantization coefficients) QS corresponding to respective blocks, and a coding unit RLE0a for subjecting the outputs (quantized components) Qs from the quantization unit to a variable length coding process.
Next, its operation will be described.
When an image signal Vin is inputted to the image coding apparatus 201a, the blocking unit Blk divides the inputted image signal Vin into image signals corresponding to block units, to generate an image signal (blocked image signal) BlkS corresponding to each block. The frequency transformation unit Trans transforms the blocked image signal BlkS into frequency components TransS according to DCT (Discrete Cosine Transformation) or Wavelet transformation. The quantization unit Q quantizes the frequency components TransS in a predetermined quantization step on the basis of a quantization parameter QP to output quantized components QS, as well as outputs the quantization parameter QP. Then, the coding unit RLE0a subjects the quantized components QS to a variable length coding process, and outputs a coded steam Str0a.
FIG. 31 is a block diagram for explaining the coding unit RLE0a that constitutes the image coding apparatus 201a.
This coding unit RLE0a has a zigzag scanner Scan for transforming the outputs (quantized components) QS of the quantization unit Q in a two-dimensional array into quantized component Coef in a one-dimensional array (i.e., predetermined order), and a variable length coder VLC for subjecting the quantized components Coef outputted from the zigzag scanner Scan to a variable length coding process.
When the quantized components QS outputted from the quantization unit Q are inputted to the coding unit RLE0a, the zigzag scanner Scan transforms the quantized components QS in a two-dimensional array from the quantization unit Q into quantized components Coef in a one-dimensional array (predetermined order), and outputs the quantized components.
FIG. 43 is a diagram for specifically explaining the process for transforming the quantized components QS by the zigzag scanner Scan.
As shown in FIG. 43, the quantized components QS outputted from the quantization unit Q have a two-dimensional array, i.e., an array in which the quantized components QS are arranged in the form of a matrix on a two-dimensional frequency region Fr according to the height of the horizontal frequency component and the height of the vertical frequency component.
The zigzag scanner Scan carries out a process for scanning the quantized components QS in the two-dimensional array in a zigzag manner as shown by arrows Y1 to Y7, to transform the components into quantized components Coef in a one-dimensional array. That is, in this scan process, a predetermined order along the scanning course is set with respect to the plural quantized components QS in the two-dimensional array.
Then, the variable length coder VLC assigns codes to the quantized components Coef which are outputted from the zigzag scanner Scan, with using a code table that shows a correlation between numerical values indicating the sizes of the quantized components and codes (code words), to transform the quantized components into a coded stream Str0a corresponding to each block.
FIG. 32 is a block diagram for explaining an image decoding apparatus 202a corresponding to the image coding apparatus 201a as shown in FIG. 30.
This image decoding apparatus 202a decodes the coded stream Str0a which is outputted from the conventional image coding apparatus 201a as shown in FIG. 30.
The image decoding apparatus 202a has a decoding unit RLD0a for decoding the coded stream Str0a which is outputted from the image coding apparatus 201a, and an inverse quantization unit IQ for subjecting outputs (decoded quantization components) DQS from the decoding unit RLD0a to an inverse quantization process.
The image decoding apparatus 202a further includes an inverse frequency transformation unit ITrans for subjecting outputs (decoded frequency components) ITransS from the inverse quantization unit IQ to an inverse frequency transformation process, and a deblocking unit Deblk for generating a decoded image signal Vout corresponding to each picture on the basis of outputs (decoded blocked image signals) DBlkS from the inverse frequency transformation unit ITrans.
Next, its operation will be described.
When the coded stream Str0a is inputted from the image coding apparatus 201a to the image decoding apparatus 202a, the decoding unit RLD0a decodes the coded stream Str0a and outputs decoded quantized components DQS. The operation of the decoding unit RLD0a is the inverse of the operation of the coding unit RLE0a.
The inverse quantization unit IQ carries out the inverse of the operation of the quantization unit Q, i.e., an operation of inversely quantizing the decoded quantized components DQS with referring to the quantization parameter QP, and outputs decoded frequency components ITransS. The inverse frequency transformation unit ITrans carries out the inverse of the operation of the frequency transformation unit Trans, i.e., an operation of subjecting the decoded frequency components ITransS to inverse DCT or inverse wavelet transformation, to reconstitute decoded image signals DBlkS corresponding to respective blocks. Then, the deblocking unit DeBlk integrates the decoded image signals DBlkS of the respective blocks to output a decoded image signal Vout corresponding to each picture (frame).
FIG. 33 is a block diagram for explaining the decoding unit RLD0a that constitutes the image decoding apparatus 202a.
The decoding unit RLD0a has a variable length decoder VLD for subjecting the coded stream Str0a to a variable length decoding process to decode the quantized component Coef corresponding to each code included in the coded stream Str0a, and an inverse zigzag scanner IScan for reconstituting quantized components DQS in a two-dimensional array from the decoded quantized components Coef in a one-dimensional array, which are outputted from the variable length decoder VLD.
In this decoding unit RLD0a, the variable length decoder VLD decodes the coded stream Str0a according to the inverse operation to the variable length coder VLC, and outputs quantized components Coef corresponding to codes (code words). Then, the inverse zigzag scanner IScan carries out the inverse operation to the zigzag scanner Scan, to reconstitute decoded quantized components DQS in a two-dimensional array from the quantized components Coef in a one-dimensional array, which are outputted from the variable length decoder VLD, and outputs the decoded quantized components DQS to the inverse quantization unit IQ.
Japanese Published Patent Application No. Hei.6-311534 discloses a method in which an image signal is divided into a luminance signal and a color-difference signal to subject the obtained signals to a variable length coding process.
The plural quantized components corresponding to respective blocks, to which the predetermined order has been set, are data including a high redundancy, i.e., data in which plural coefficients whose values are zero (zero coefficients) continue after a coefficient whose value is not zero (non-zero coefficient). To encode such quantized components, a method in which quantized components are encoded with its redundant information being deleted, for example, a run-length encoding method in which quantized components are encoded by using a run value that indicates the number of successive zero coefficients and a level value that indicates a value of a non-zero coefficient following the zero coefficients has been conventionally employed.
Hereinafter, a conventional image coding apparatus using the run-length encoding method will be described.
FIG. 34 is a block diagram illustrating a conventional image coding apparatus that carries out the run-length encoding.
This image coding apparatus 201b includes, in place of the coding unit RLE0a of the image coding apparatus 201a shown in FIG. 30, a run-length encoding unit RLE0b for subjecting outputs (quantized components) QS from the quantization unit Q to run-length encoding and outputting a coded stream Str0b. Other components are the same as those of the image coding apparatus 201a.
The operation of the image coding apparatus 201b is different from that of the image coding apparatus 201a only in the operation of the coding unit RLE0b.
FIG. 35 is a block diagram illustrating a specific construction of the coding unit RLE0b in the image coding apparatus 201b.
This run-length encoding unit RLE0b has, like the coding unit RLE0a, a zigzag scanner Scan for transforming outputs (quantized components) QS in a two-dimensional array from the quantization unit Q into quantized components Coef in a one-dimensional (i.e., a predetermined order).
Then, this run-length encoding unit RLE0b further includes a run calculator RunCal for calculating the number of successive quantized components whose values are zero (zero coefficients) Coef and outputting a run value Run indicating the number of successive zero coefficients, and a level calculator LevCal for calculating a value of a quantized component whose value is not zero (non-zero coefficient), following the zero coefficients, and outputting a level value Lev indicating the value of the non-zero coefficient.
The run-length encoding unit RLE0b further includes a variable length coder LevVLC for subjecting the level value Lev that is outputted from the level calculator LevCal to a variable length coding process and outputting a code string (level value code string) LStr, a variable length coder RunVLC for subjecting the run value Run that is outputted from the run calculator RunCal to a variable length coding process and outputting a code string (run value code string) RStr, and a multiplexer MUX for multiplexing the level value code string LStr and the run value code string RStr for each block and outputting a multiplexed coded stream Str0b.
Next, its operation will be described.
The zigzag scanner Scan transforms the quantized components QS in a two-dimensional array, which are outputted from the quantization unit Q, into quantized components Coef in a one-dimensional array (predetermined order), and outputs the quantized components Coef. The transformation process for the quantized components Qs by the zigzag scanner Scan is carried out in the same manner as that in the coding unit RLE0a of the image coding apparatus 201a.
The run calculator RunCal calculates the number of successive zero coefficients on the basis of the quantized components Coef which are outputted from the zigzag scanner Scan, and outputs a run value Run indicating the calculated number. The level calculator LevCal calculates a value of a non-zero coefficient that follows the successive zero coefficients, on the basis of the quantized components Coef outputted from the zigzag scanner Scan, and outputs a level value Lev indicating this value.
Here, the run calculator RunCal generates a special value EOB (End of Block) when detecting the highest frequency component (the last non-zero coefficient) in the target block to be processed, to inform that subsequent higher frequency components have all zero value.
Further, the variable length coder RunVLC subjects the run value Run which is outputted from the run calculator RunCal to a variable length coding process for assigning a code (code word) to the run value according to a code table or arithmetic operation, and outputs a code string RStr. The variable length coder LevVLC subjects the level value Lev which is outputted from the level calculator LevCal to a variable length coding process for assigning a code (code word) to the level value according to a code table or arithmetic operation, and outputs a code string LStr.
The multiplexer MUX multiplexes the code string LStr and the code string RStr for each block, and outputs a multiplexed coded stream Str0b.
Here, the process for multiplexing the code string LStr and the code string RStr is carried out for each block, for example, in such manner that the code string RStr corresponding to all run values for a target block is followed by the code string LStr corresponding to all level values for the target block, or the code string LStr corresponding to all level values for a target block is followed by the code string RStr corresponding to all run values for the target block.
The image coding apparatus as described above for encoding plural quantized coefficients in a predetermined order, by using the run value Run indicating the number of quantized components whose values are zero (zero coefficients) Coef, and the level value Lev indicating a value of a quantized component whose value is not zero (non-zero coefficient) Coef, following the zero coefficients, can encode the plural quantized coefficients at a higher coding efficiency, while removing its redundant information.
FIG. 36 is a block diagram for explaining an image decoding apparatus 202b corresponding to the image coding apparatus 201b as shown in FIG. 34.
This image decoding apparatus 202b decodes the coded stream Str0 that is outputted from the conventional image coding apparatus 201b as shown in FIG. 34.
The image decoding apparatus 202b has, in place of the decoding unit RLD0a of the image decoding apparatus 202a shown in FIG. 32, a run-length decoding unit RLD0b for subjecting the coded stream Str0b that is outputted from the image coding apparatus 201b to a run-length decoding process. Other components are identical to those of the image decoding apparatus 202a.
The operation of the image decoding apparatus 202b is different from the image decoding apparatus 202a only in the operation of the decoding unit RLD0b.
FIG. 37 is a block diagram illustrating a specific construction of the run-length decoding unit RLD0b in the image decoding apparatus 202b.
This run-length decoding unit RLD0b has a demultiplexer DMUX for demultiplexing the multiplexed coded stream Str0b that is outputted from the image coding apparatus 201b to obtain the code string LStr corresponding to the level values and the code string RStr corresponding to the run values, a variable length decoder LevVLD for subjecting the code string LStr to a variable length decoding process to reconstitute the level values Lev, a variable length decoder RunVLC for subjecting the code string RStr to a variable length decoding process to reconstitute the run values Run, and an inverse zigzag scanner IScan for reconstituting decoded quantized components DQS in a two-dimensional array from decoded quantized components in a one-dimensional array, which are represented by the level values Lev and the run values Run.
Next, its operation will be described.
In the image decoding apparatus 202b, the run-length decoding unit RLD0b carries out the inverse operation to the run-length encoding unit RLE0b. That is, the run-length decoding unit RLD0b demultiplexes the multiplexed coded stream Str0b to obtain the code string Lstr corresponding to the level values and the code string RStr corresponding to the run values.
Then, the variable length decoder LevVLD decodes the code string LStr corresponding to the level values by the inverse operation to the variable length coder LevVLC, and outputs the level values Lev. The variable length decoder RunVLD decodes the code string RStr corresponding to the run values by the inverse operation to the variable length coder RunVLC, and outputs the run values Run.
The inverse zigzag scanner IScan reconstitutes decoded quantized components DQS in a two-dimensional array from the quantized components in a one-dimensional array, which are represented by the level values Lev and the run values Run, by the inverse operation to the zigzag scanner Scan, and outputs the decoded quantized components to the inverse quantization unit IQ. However, this inverse zigzag scanner IScan (see FIG. 37) is different from the inverse zigzag scanner IScan as shown in FIG. 33 in that the level value Lev and the run value Run are inputted thereto. Thus, the inverse zigzag scanner IScan shown in FIG. 37 has a function of converting a coefficient that is represented by the level value Lev and the run value Run into a quantized components Coef.
According to the image decoding apparatus that carries out a decoding process for decoding plural quantized coefficients in a predetermined order, by using the run value Run indicating the number of quantized components whose values are zero (zero coefficients) Coef and the level value Lev indicating a value of a quantized component whose value is not zero (non-zero coefficient) Coef, following the zero coefficients, coded data which is obtained by coding plural quantized components according to run-length encoding with removing its redundant information at a higher coding efficiency is decoded satisfactorily.
Hereinafter, another example of the conventional image coding apparatus using the run-length encoding method will be described.
FIG. 38 is a block diagram illustrating another example of the image coding apparatus that employs the conventional run-length encoding unit. Almost all of the conventional image coding apparatuses which are compliant with standards such as MPEG, or H.261 and H.263 (ITU), or a draft H26L standard (TML8) that is now being planned have a construction as shown in FIG. 38.
This image coding apparatus 201c performs coding of quantized coefficients using the run value and the level value, like the image coding apparatus 201b shown in FIG. 34, while this image coding apparatus 201c does not perform a variable length coding process for the run value and the level value separately like the image coding apparatus 201b, but performs a variable length coding process for a pair of the run value and the level value (run-level pair).
To be more specific, the image coding apparatus 201c has, like the image coding apparatus 201b, a blocking unit Blk to which an image signal Vin is inputted, a frequency transformation unit Trans for subjecting an output BlkS from the blocking unit to frequency transformation, and a quantization unit Q for quantizing outputs (frequency components) TransS from the transformation unit. The image coding apparatus 201c further includes a run-length encoding unit RLE0c for subjecting outputs (quantized components) QS from the quantization unit to a run-length encoding process for transforming a run-level pair comprising a run value and a level value into a variable length code.
Next, its operation will be described.
The blocking unit Blk divides the image signal Vin into image signals corresponding to block units to generate pixel value components (blocked image signals) BlkS. The frequency transformation unit Trans transforms the pixel value components BlkS into frequency components TransS according to DCT (Discrete Cosine Transformation) or Wavelet transformation. The quantization unit Q quantizes the frequency components TransS on the basis of a quantization parameter QP to output quantized components QS, as well as outputs the quantization parameter Q. The run-length encoding unit RLE0c subjects the quantized components QS to run-length encoding, and outputs a coded stream Str0c.
Here, the block is an area of a predetermined size in the picture (image space), which is a unit in a coding process for an image signal, and composed of a predetermined number of pixels. The run-length encoding is a process for transforming a pair comprising a run value that indicates the number of successive quantized components whose values are zero (zero coefficients) and a level value that indicates a value of a quantized component whose value is not zero (non-zero coefficient), following the zero coefficients, into a variable length code, in other words, a process for assigning one variable length code (code word) to a pair of a run value and a level value (run-level pair).
Next, the run-length encoding unit RLE0c will be specifically described.
FIG. 39 is a block diagram illustrating a conventional run-length encoding unit RLE0c.
This run-length encoding unit RLE0c has, like the run-length encoding unit RLE0b as shown in FIG. 35, a zigzag scanner Scan for transforming the outputs (quantized components) QS in a two-dimensional array from the quantization unit Q, into quantized components Coef in a one-dimensional array (i.e., a predetermined order); a run calculator RunCal for calculating the number of successive quantized components whose values are zero (zero coefficients) Coef and outputting a run value Run; and a level calculator LevCal for calculating a value of a quantized component whose value is not zero (non-zero coefficient) Coef, following the zero coefficients, and outputting a level value Lev.
The run-length encoding unit RLE0c further includes a run-level encoder RunLevEnc for obtaining a code number Code corresponding to a pair of the level value Lev and the run value Run according to a code table or arithmetic operation on the basis of the outputs from the run calculator RunCal and the level calculator LevCal; and a variable length coder VLC for assigning a code word to the code number Code to generate a coded stream Str0c corresponding to the image signal Vin.
Next, its operation will be described.
In the run-length encoding unit RLE0c, like in the run-length encoding unit RLE0b, the zigzag scanner Scan transforms quantized components QS in a two-dimensional array, which are outputted from the quantization unit Q, into quantized components Coef in a one-dimensional array (predetermined order), and outputs the obtained quantized components.
FIG. 43 is a diagram for specifically explaining a process for transforming the quantized components QS by the zigzag scanner Scan.
The quantized components QS outputted from the quantization unit Q have a two-dimensional array as shown in FIG. 43, i.e., an array in which the quantized components QS arranged in the form of matrix on a two-dimensional frequency region Fr according to the size of the horizontal frequency component and the size of the vertical frequency component.
The zigzag scanner Scan carries out the process for scanning the quantized components QS in the two-dimensional array in a zigzag manner, as shown by arrows Y1 to Y7, to transform the quantized components QS into quantized components Coef in a one-dimensional array. That is, this scanning process sets a predetermined order along the scanning course, with respect to the plural quantized components QS in the two-dimensional array.
The run calculator RunCal calculates the number of successive zero coefficients on the basis of the quantized components Coef outputted from the zigzag scanner Scan, and outputs a run value Run indicating the calculated number. The level calculator LevCal calculates a value of a non-zero coefficient following the successive zero coefficients, on the basis of the quantized components Coef outputted from the zigzag scanner Scan, and outputs a level value indicating the calculated value. Here, the run calculator RunCal outputs a specific value EOB (End of Block) when detecting the highest frequency component (the last non-zero coefficient) in a target block to be processed, to inform that subsequent higher frequency components have all zero value.
Further, the run-level encoder RunLevEnc obtains a code number Code corresponding to a pair of the level value Lev and the run value Run on the basis of the outputs from the run calculator RunCal and the level calculator LevCal, according to a code table or arithmetic operation. The variable length coder VLC encodes the code number Code that is obtained by the converter RunLevEnc, i.e., assigns a code word (bit string) to the code number to generate a coded stream Str0.
FIG. 42 shows an example of a code table that is employed by the run-length encoding unit RLE0c. The code table (first coding table) T1 shown in FIG. 42 shows a code table corresponding to DC components of a color-difference signal that is compliant with a draft H.26L standard (TML8) that is now being planned.
This code table T is composed of a regularly generable part including code numbers corresponding to pairs of level values and run values which can be calculated according to an arithmetic operation using level values and run values (regularly build VLC), and an irregular part including code numbers corresponding to pairs of level values and run values which cannot be calculated by the arithmetic operation (table look up VLC). Further, a bit string (not shown) is assigned to each code number Code as a code word in a one-to-one relationship. A shorter code word is assigned to a code number Code having a smaller value.
Next, a conventional decoding apparatus corresponding to the image coding apparatus 201c will be described.
FIG. 40 is a block diagram illustrating an image decoding apparatus 202c that employs a conventional run-length decoding unit RLD0.
This image decoding apparatus 202c decodes the coded stream Str0c that is outputted from the conventional image coding apparatus 201c shown in FIG. 39.
The image decoding apparatus 202c decodes quantized coefficients using the run value and the level value, as the image decoding apparatus 202b in FIG. 36, while this image decoding apparatus 202c does not carry out variable length decoding of the run value and the level value separately like the image decoding apparatus 202b, but carries out variable length decoding of a pair comprising the run value and the level value (run-level pair)
To be more specific, the image decoding apparatus 202c has a run-length decoding unit RLD0c that subjects the coded stream Str0c outputted from the image coding apparatus 201c to a run-length decoding process using a run-level pair comprising a run value and a level value. The image decoding apparatus 202c further has, as the image decoding apparatus 202b, an inverse quantization unit IQ for subjecting outputs (decoded quantized components) DQS from the run-length decoding unit RLDc to an inverse quantization process; a inverse frequency transformation unit ITrans for subjecting outputs (decoded frequency components) ITransS from the inverse quantization unit IQ to an inverse frequency transformation process; and a deblocking unit DeBlk for generating a decoded image signal Vout corresponding to each picture on the basis of outputs (decoded pixel value components) DBlkS from the inverse frequency transformation unit ITrans.
Next, its operation will be described.
In the image decoding apparatus 202c, the run-length-decoding unit RLD0c carries out the inverse of the operation of the run-length encoding unit RLE0c. To be more specific, the run-length decoding unit RLD0c subjects the coded stream Str0c to a run-length decoding process to output decoded quantized components DQS. The inverse quantization unit IQ carries out the inverse operation to the quantization unit Q, i.e., an operation of inversely quantizing the decoded quantized components DQS with referring to a quantization parameter QP to output decoded frequency components ITransS. The inverse frequency transformation unit ITrans carries out the inverse operation to the frequency transformation unit Trans, i.e., an operation of subjecting the decoded frequency components ITransS to inverse DCT or inverse Wavelet transformation, to reconstitute a decoded pixel value signal (decoded blocked image signal) DBlkS corresponding to each block. The deblocking unit DeBlk integrates the image pixel value components for the respective blocks, and outputs a decoded image signal Vout corresponding to each picture (frame).
Next, the run-length decoding unit RLD0c will be specifically described.
FIG. 41 is a block diagram for explaining a specific construction of the run-length decoding unit RLD0c.
This run-length decoding unit RLD0c has a variable length decoder VLD for subjecting the coded stream Str0c to a variable length decoding process to obtain a code number Code corresponding to each code (code word) included in the coded stream Str0c; a run-level detector RunLevDec for detecting a pair of a level value Lev and a run value Run, corresponding to the code number Code; and an inverse zigzag scanner IScan for reconstituting decoded quantized components DQS in a two-dimensional array from decoded quantized components in a one-dimensional array, which are represented by the level values Lev and the run values Run, on the basis of the pairs of the level values Lev and the run values Run.
Next, its operation will be described.
In this run-length decoding unit RLD0c, the variable length decoder VLD decodes the coded stream Str0c, and outputs a code number Code corresponding to a code word (bit string) according to the inverse operation to the variable length coder VLC. The run-level detector RunLevDec refers to a code table or performs an arithmetic operation to output a pair of a level value Lev and a run value Run, corresponding to the code number Code, according to the inverse operation to the run-level encoder RunLevEnc. The inverse zigzag scanner IScan reconstitutes decoded quantized components DQS in a two-dimensional array from quantized components in a one-dimensional array which are represented by the pairs of the level values Lev and the run values Run according to the inverse operation to the zigzag scanner Scan, and outputs the decoded quantized components DQS to the inverse quantization unit IQ.
Japanese Published Patent Application No. Hei.6-237184 discloses a run-length encoding method in which plural coefficients in a predetermined order are coded using a run value Run that indicates the number of quantized components whose values are zero (zero coefficients) Coef, and a level value Lev that indicates a value of a quantized component whose value is not zero (non-zero coefficient) Coef, following the zero coefficients.
Japanese Patent No. 3144456 (corresponding to Japanese Published Patent Application No. Hei.8-79088) discloses a method by which a variable length coding table (VLC table) is changed according to the value of a differential motion vector value when the differential motion vector value is coded using a variable length coding table in a method for predictively coding digital video data.
Further, an arithmetical coding is known as another method by which the pixel values are variable-length coded, in which variable length coding is performed according to an arithmetic operation by using probability in which the pixel value may take a predetermined value. According to the arithmetical coding, a code is derived from the probability, so that a probability table in which probabilities corresponding to individual situations are described corresponds to the VLC table. Here, "All about MPEG-4" (first edition, first print, published Sep. 30, 1998, written and edited by Miki Sukeichi, pp. 69–73, Kogyo Chosakai Publishing Co., Ltd.) describes a method by which pixel values of pixels corresponding to a coding target are subjected to arithmetic coding by changing a probability table on the basis of a prediction method (context) for a coding target pixel which are predicted from pixel values of the surrounding pixels.
The above-mentioned coding unit RLE0a of the conventional image coding apparatus 201a performs variable length coding for plural quantized coefficients which are obtained by quantizing frequency components of image data, for each predetermined processing unit (block). This coding unit employs a predetermined code table that indicates correspondences between numerical value information showing the size of each quantized coefficient and a code (code word). In the variable length coding process by the coding unit, redundant information included in the quantized coefficient (data to be processed) cannot be removed sufficiently and, thus, the compression rate may be further improved.
Also in the run-length encoding unit that carries out variable length coding of plural quantized coefficients using a run value that indicates the number of quantized components whose values are zero (zero coefficients) Coef, and a level value that indicates a value of a quantized component whose value is not zero (non-zero coefficient) Coef, following the zero coefficients, like the coding units RLE0b or RLE0c in the conventional image coding apparatus 201b or 201c, redundant information included in the quantized coefficients in the variable length coding process is not sufficiently removed.
Further, the decoding unit RLD0a of the conventional image decoding apparatus 202a or the run-length decoding unit RLD0b or RLD0c of the conventional image decoding apparatus 202b or 202c corresponds to a coding unit which cannot sufficiently remove redundant information included in the quantized coefficients in the variable length coding process for the quantized coefficients.
Further, as for the method by which a variable length coding table (VLC table) is changed according to the value of a differential motion vector value when the differential motion vector value is coded using a variable length coding table in a method for predictively coding digital video data, an effective change of the coding table in a variable length coding process for data having such characteristics that plural zero coefficients successively follow, like the quantized coefficients which are obtained by quantizing frequency components of an image signal has not been known.
The present invention is made to solve the above-mentioned problems, and this invention has for its object to provide a variable length coding method and a variable length decoding method, which can remove redundant information included in target data (quantized coefficients) for a variable length coding process, more effectively according to characteristics of the quantized coefficients and states of a coding process for the quantized components, thereby further increasing a compression rate of an image signal or the like.

Variable length coding method and variable length decoding method

Matsushita Electric Industrial Co., Ltd.


An exercise treadmill is disclosed. The treadmill can be constructed with no obstructing front rails, with one or more side rails, and/or with a structural flat or ramped surface at the front allowing the user to exercise with unconstrained motion. The treadmill can further include one or more accommodations to help the user stay safe, remain longitudinally centered, and/or adjust speed with controls built into the treadmill, or automatically based on body position relative to sensors built into the side rails. The treadmill belt may be motor driven, or be user driven and dynamically moderated by resistance. The treadmill configuration can be utilized to provide a virtualized exercise experience for the user.

Treadmills are generally built with three main constraints: (1) A frontal rail generally including speed/incline controls; (2) a lack of side rails that extend meaningfully along the longitudinal axis of the treadmill; and (3) consistent belt speed set by the user—which may vary as the user shifts controls or an interval program occasionally (every 1+ minutes, perhaps) alters the speed. The aspects of the front rail and the need to use its controls cause the vast majority of runners to position themselves very close to the front rail to manage the controls, view the media console, and to ensure a sense of safety that they won't fall too far back to the center or rear of the treadmill where there are no supportive rails on one or both sides. The aspect of consistent belt speed also causes runners to drift as they constantly vary their pace, unconsciously favoring acceleration, to maintain a sense of security near the front of the treadmill. Positioned at the front rail, runners compromise form, efficiency and satisfaction. The frontal positioning of the control component and display including speed and distance ran/walked also becomes a visual focal point and distance counting distraction that's fundamentally different from an outdoor running experience.
Differences between over ground and treadmill running are easily observed once they are realized. This can be observed at any health club even with a small sample of runners. First, the observer will note that runners position their body very close to the front rail of the treadmill. From there, running differences can be observed vs. more natural outdoor running. Rather than letting shoulders and arms relax and move freely—with arms at about a 90 degree angle and hands practically brushing by the "pockets"—runners at the front rail of a treadmill cock their shoulders and position arms high and at a tight angle, like a boxer. Meanwhile, the media console is often between waist and chest high, far below the area that's anywhere from a point fifteen yards (e.g., fourteen meters) on the road ahead or the horizon line that runners should focus on for proper form. As a result of the constraints of current treadmill formats, runner's hip motion, footfall and stride must also be adversely affected by the lack of proper motion in his/her torso and upper body. Various research proves that out, having measured shorter strides and differences in ground reaction forces, for example.
Altogether, these factors resulting from the format of current treadmills challenge comfort, compromise form, and increase a likelihood of injury in a sport that already suffers from a high injury rate.
Various treadmills have been proposed and made which provide alternative softer treadmill surfaces to make them more comfortable. While these options may drive buying behavior, one must realize that the predominant running surface, the one for which running shoes are designed, is pavement. Meanwhile, treadmill manufacturers continue to do more to emphasize the front component, by adding media systems with entertainment and more programming options.
In other non-fitness treadmill categories, specialty treadmills include those designed for a treadmill desk application. These treadmills are generally shorter than running treadmills and have different motor types built for walking speeds up to about four miles per hour (MPH) or approximately 6.5 kilometers per hour. The TreadDesk™ product is one such example which also does not include any side-rails. Another approach indicates the aspects for desk mounting and safety in a treadmill walking scenario.
In the medical area, the GE CASE Exercise Testing System includes a treadmill that is designed to be used in conjunction with physiological monitors and a live operator who uses a remote monitor to monitor the patient and increase belt speed in order to push the patient to an 85% threshold or higher for a period of time sufficient for a stress test.


An error diffusion halftoning system and a method of managing halftoning errors utilize a quantization technique to reduce the required size of a primary error buffer that is needed to diffuse the halftoning errors. By implementing the quantization technique, the primary error buffer can be reduced from an 8-bits-per-bin error buffer to a 2-bits-per-bin error buffer for 256 grayscale. The reduction in bin size decreases the cost of the primary error buffer and, consequently, the cost of an error diffusion halftoning (EDH) device of the system that generates halftone values from grayscale values of a digital image. The quantization technique is executed on cumulated half-toning errors, derived from apportioned halftoning errors associated with previously processed pixels. In addition, the system and method utilize an error diffusion procedure to diffuse quantization errors that are produced from the execution of the quantization technique. In one embodiment, entire quantization errors are sequentially transmitted to a supplemental error diffuser, so that each quantization error can be introduced to the grayscale value of the next pixel to be processed. In another embodiment, the quantization errors are apportioned using predefined multiplicative parameters and eventually diffused to two or more unprocessed pixels that are adjacent to the pixel currently being processed.

The invention relates generally to halftoning techniques and more particularly to an error diffusion halftoning technique.
Digital images provide a convenient format for transmission, modification, and/or reproduction of images. When an image is captured digitally, grayscale information for each pixel of an image is extracted. Typically, 256 grayscale levels are utilized to extract the grayscale information. However, the majority of printers that are currently in use are binary with respect to their printing methods. That is, the printers operate to reproduce the original image either by depositing or by refraining to deposit a small amount of ink or toner for each pixel of the captured image. The binary nature of these printers allows only two levels of grayscale to be printed for each pixel. Thus, digitally captured images having more than two levels of grayscale cannot be reproduced by the binary printers, unless a special printing technique, such as halftoning, is utilized.
A halftoning technique is a process for printing different shades of grayscale by varying the density of xe2x80x9cdarkxe2x80x9d pixels that have been deposited with ink or toner. A lower density of dark pixels equates to a lighter shade of grayscale, while a higher density of dark pixels equates to a darker shade of grayscale. Since the density of dark pixels can vary in numerous degrees, the number of grayscales that can be produced using the halftoning technique is far greater than two levels. As long as the pixels are sufficiently small, the individual dark pixels will not be apparent to a viewer. Instead, the viewer will see smooth areas having different shades of grayscale, which are directly related to the density of dark pixels.
A common type of halftoning technique is known as xe2x80x9can error diffusion halftoning technique.xe2x80x9d In error diffusion halftoning, a halftoning error associated with a generated halftone signal for each pixel of a digital image is distributed among neighboring pixels in order to determine which pixel should be deposited with ink or toner. The halftone signal is derived by comparing a given value, which is a combined value of a grayscale value of a pixel and a cumulative error from previously processed pixels, with a predefined threshold value. The difference between the given value and the halftone value is the halftoning error. By distributing the halftoning errors, the density of dark pixels will be determined by the grayscale values from a number of surrounding pixels. Consequently, regions of the digital image having lighter shades of grayscale will yield lower densities of dark pixels, while regions having darker shades of grayscale will yield higher densities of dark pixels. In this fashion, digital images having more than two shades of grayscale can be printed using a binary printer.
In FIG. 1, a conventional system 10 that executes error diffusion halftoning is shown. The system includes an input device 12, an error diffusion halftoning (EDH) device 14, and a binary output device 16. The input device provides a digital image that is to be printed by the binary output device. The input device may be a scanner that can capture the digital image from a photograph, a digital camera that can capture the digital image from an actual scene, or a storage device that can receive the digital image from an external source. The error diffusion device includes a summing unit 18, a thresholding module 20, a subtraction unit 22, an error diffuser 24, and an error buffer module 26.
In operation, the system 10 processes the digital image by sequentially operating on the image pixels of the digital image in a raster scan order, which is a left-to-right, top-to-bottom sequence. For each pixel of the image, a grayscale value gi,j of that pixel is transmitted from the input device 12 to the summing unit 18 of the EDH device 14, where gi,j xcex5[0,255] for 256 grayscale. The values i and j identify the row and column, respectively, of the current pixel being processed. The summing unit 18 combines the grayscale value gi,j with a final error ei,j and outputs a summed value si,j. The final error ei,j is derived from halftoning errors associated with the previous pixels that were processed by the EDH device. The summed value si,j is then transmitted to the thresholding module 20 and the subtraction unit 22. The thresholding module compares the summed value si,j to a threshold value, e.g., 127 for 256 grayscale. The comparison produces an output halftone value hi,j, which is one of two values, e.g., 0 or 255. If the summed value si,j is less than the threshold value, the output halftone value hi,j equates to a first value, e.g., 0, that directs the output device 16 to refrain from depositing ink or toner. However, if the summed value si,j is equal to or greater than the threshold value, the output halftone value hi,j equates to a second value, e.g., 255, that directs the output device to deposit the ink or toner.
The output halftone value hi,j is also transmitted to the subtraction unit 22 to derive a halftoning error that results from converting the summed value si,j into one of two halftone values. The subtraction unit subtracts the halftone value hi,j from the summed value si,j. The result of this operation is a halftoning error ni,j, which is transmitted to the error diffuser 24. The error diffuser then divides the halftoning error ni,j using a known distribution process, such as the Floyd-Steinberg error diffusing process. The divided halftoning errors are transmitted to the error buffer module 26. The error buffer module processes the divided halftoning errors, such that each divided halftoning error can be diffused into a neighboring pixel of the current pixel. These divided halftoning errors are combined with other divided halftoning errors from previously processed pixels to form final errors that are to be diffused into subsequently processed pixels. The final errors are temporarily stored in an error buffer (not shown) within the error buffer module. The error buffer has a capacity to store the final errors for an entire row of image pixels. For 256 grayscale, each bin of the primary error buffer is an 8-bit bin. When the grayscale value gi,j+1 of the next pixel is processed, a final error ei,j+1 stored in the bin of the error buffer associated with that pixel is transmitted to the summing unit 18. This final error is combined with the grayscale value gi,j+1 and the above-described process is repeated. In this fashion, the halftoning errors from the pixels of the digital image are distributed to reproduce the digital image as a halftone image using the binary output device 16.
Although conventional error diffusion halftoning systems, such as the system 10, operate well for their intended purpose, what is needed is a cost-efficient error diffusion system and a method of managing errors in such a system.
An error diffusion halftoning system and a method of managing halftoning errors utilize a quantization technique to reduce the required size of a primary error buffer that is needed to diffuse the halftoning errors. By implementing the quantization technique, the primary error buffer can be reduced from an 8-bits-per-bin error buffer to a 2-bits-per-bin error buffer for 256 grayscale. The reduction in bin size decreases the cost of the primary error buffer and, consequently, the cost of an error diffusion halftoning (EDH) device of the system that generates halftone signals from grayscale values of a digital image.
The error diffusion halftoning system includes an input device, the EDH device, and a binary output device. The input device may be a digital scanner, a digital camera, or a storage device that can acquire digital images. The binary output device may be a conventional inkjet or laser printer. The EDH device is operatively connected to the input device and the binary output device to process grayscale pixel values of a given digital image from the input device, generating halftone signals, and to transmit the generated halftone signals to the binary output device. The halftone signals are used by the binary output device to decide whether to deposit or to refrain from depositing ink or toner in order to print a halftone image in accordance with the given digital image. In addition, the EDH device operates to manage the halftoning errors that are produced from the generation of the halftone signals.
The EDH device includes a summing unit, a thresholding module, a subtraction unit, an error diffuser, and a quantization-error diffusion (QED) module. The summing unit is positioned to receive a grayscale value from the input device and a corresponding final error from the QED module for each pixel being processed by the EDH device. The final error contains halftoning errors and quantization errors from previously processed grayscale values. The halftoning errors are the resulting products of a thresholding operation executed by the thresholding module, while the quantization errors are the resulting products of a quantization operation executed by the QED module. The summing unit combines the received grayscale value and the received final error to produce a summed value, which is transmitted to the thresholding module and the subtraction unit.
After the summed value is received by the thresholding module, the summed value is thresholded by the thresholding module using a predefined threshold value to generate a halftone signal. The halftone signal is then transmitted to the binary output device to control the depositing operation of the output device. The halftone signal is also transmitted to the subtraction unit, where the summed value from the summing unit is subtracted by the halftone signal to derive a halftoning error. The halftoning error is used by the error diffuser to distribute portions of the halftoning error to different components of the QED module, so that the portions of the halftoning error can be diffused to unprocessed pixels that are adjacent to the current pixel being processed. In the preferred embodiment, the error diffuser is configured to generate four apportioned halftoning errors from the halftoning error using a Floyd-Steinberg scheme. That is, the halftoning error is multiplied using parameters a, b, c and d, where a={fraction (3/16)}, b={fraction (5/16)}, c={fraction (1/16)} and d={fraction (7/16)}. However, the error diffuser may be configured to generate the four apportioned halftoning errors using a different set of parameters. In an alternative embodiment, the error diffuser may be configured to generate any number of apportioned halftoning errors using a corresponding number of predefined parameters.
The QED module operates to manage the apportioned halftoning errors for each pixel of the digital image being processed. The apportioned halftoning errors from different pixels are combined by the QED module and added to selected pixels when these pixels are processed by the EDH device.
The QED module includes the primary error buffer, an intermediate error buffer, a supplemental error buffer, a quantization unit, a de-quantization unit, and three weighting units. The primary error buffer includes a number of bins. Each bin of the primary error buffer has a capacity to store 2-bit information. The number of bins included in the primary error buffer is not critical to the invention. However, the primary error buffer contains a sufficient number of bins to store error information for an entire pixel row of a typical digital image that is to be processed by the system. The intermediate error buffer is a 3-bin buffer that can temporarily store three apportioned halftoning errors from the error diffuser. Similarly, the supplemental error buffer is a single bin buffer that can temporarily store the remaining apportioned halftoning error from the error diffuser. Notice that the number of bins in the intermediate and supplemental error buffers is the number of error terms to which the error is diffused. These numbers are equal to four in the present case, but may be greater or less. The intermediate and supplemental error buffers are of size 8 or more bits per bin. The intermediate error buffer is configured such that when the next pixel is processed, values stored in the bins are shifted to the left. The stored value in the far left bin of the intermediate error buffer, however, is transmitted to the quantization unit of the QED module. This configuration allows apportioned halftoning errors from different pixels to be combined and stored within the bins of the intermediate error buffer.
The quantization unit is configured to convert the stored value in the left bin of the supplemental error buffer into a quantized value using a predefined quantization table. The operation of the quantization unit produces a quantization error, which is diffused in a manner similar to the diffusion of the halftoning error. In one embodiment, the quantization error is apportioned by the three weighting units using predefined multiplicative parameters to produce three apportioned quantization errors. One of the apportioned quantization errors is transmitted to the supplemental error buffer, while the two remaining apportioned quantization errors are transmitted to the middle and right bins of the intermediate error buffer. In another embodiment, the entire quantization error is combined with an apportioned halftoning error and transmitted to the supplemental error buffer, so that the quantization error can be introduced to the grayscale value of a pixel that is to be processed next.
The de-quantization unit of the QED module is coupled to the primary error buffer. When a grayscale value of a pixel is received by the EDH device, a quantized value that corresponds to that pixel is extracted from a bin of the primary error buffer. The quantized value is then expanded by the de-quantization unit using a predefined de-quantization table. The de-quantized value is combined with a stored value in the supplemental error buffer, resulting in a final error. The final error is then added to the grayscale value of the pixel being processed to derive a summed value that will be used to generate the halftone signal. In this manner, the halftoning errors and the quantization errors of previously processed pixels are diffused to grayscale values of subsequently processed pixels.

System and memory-buffer management method for reducing random access memory requirements in error diffusion halftone applications

Hewlett-Packard Development Company, L.P.


A method, an apparatus, and a device for detecting an electronic mail (E-mail) attack. The device receives a data flow, obtains an E-mail traffic parameter of each statistic period within a predetermined number of statistic periods, where within each statistic period, the E-mail traffic parameter of each of the statistic periods is determined according to a protocol type of the received data flow, and determines that an E-mail attack is detected when the E-mail traffic parameter of each statistic period within the predetermined number of statistic periods matches a first threshold.

An E-mail attack, also called an "E-mail Bomb," is a means to attack an electronic mail (E-mail) mail box (E-mail box for short hereinafter) by continuously sending an E-mail spam to a target E-mail box within a short time so that a capacity of the target E-mail box reaches an upper limit, thereby leaving no extra space for accommodating a new E-mail. Moreover, when an E-mail attack occurs, transmission of an E-mail spam in a network consumes a great many network resources. This may lead to network congestion, causing many other E-mail boxes to fail to receive and send E-mails normally, and at the same time imposing a burden on an E-mail server.
When an E-mail attack occurs, exceptions usually appear in E-mail traffic received by the E-mail server. In general, an E-mail server receives an E-mail through a specific port (for example, a port 25), so when it is detected whether an E-mail attack occurs, statistics are usually collected on traffic for the specific port of the E-mail server, and when the E-mail traffic within a certain time exceeds a preset traffic threshold, it is deemed that an E-mail attack occurs and the traffic of the specific port of the E-mail server will be limited.
However, when this manner of detecting an E-mail attack is used, the specific port of the E-mail server also receives other data in addition to receiving E-mails. Therefore, when statistics are collected on the traffic of the specific port of the E-mail server, the traffic on which statistics are collected may include traffic of other data, for example, command data, in addition to the E-mail traffic. Consequently, a detection result of the E-mail attack is inaccurate, so it is impossible to correctly limit and handle the E-mail attack.

This patent is subject to a terminal disclaimer.

Method, apparatus, and device for detecting e-mail attack


A high beam and a low beam is disclosed, the headlight including: a first light source unit; a second light source unit; a first light output unit; a second light output unit; and a controller configured to adjust a light quantity irradiated from the light source in response to a low beam mode or a high beam mode, and to control a beam output of the first light output unit and the second light output unit by allowing the first optical unit to be arranged selectively on a light path between the light source unit and the second optical unit.

Field
The teachings in accordance with the exemplary embodiments of this present disclosure generally relate to headlights having one light source module for a high beam and a low beam, and more particularly to headlights having one light source module for a high beam and a low beam configured to selectively operate a high beam or a low beam by changing a beam having a characteristic of linearly polarized light irradiated from a single light source unit to a circularly polarized light or to an elliptically polarized light, and outputting the beam to one path or two paths in response to a low beam mode or a high beam mode.
Background
A headlight of a vehicle called a head lamp is an illumination light having an essential function of lighting a front path in a night operation, and requires a brightness level capable of ascertaining a traffic obstacle located at a 100 meter ahead of a vehicle in a night operation, albeit there being a difference in terms of performance standard stipulated by each country.
In general, the headlight that lights in order to obtain a front view in a night travel of a vehicle is operated in a high beam (high beam mode) and a low beam (low beam mode), and when the vehicle is operated at a high speed, the vehicle selects a high beam to allow a beam irradiated from the headlight to be directed upwards, whereby a driver can recognize a far-out distance. When the vehicle is operated at a low speed, a low beam is selected to allow the beam irradiated from the headlight to direct downwards to prevent a driver view of an on-coming vehicle or a front vehicle from being obstructed.
To this end, left/right headlights of most vehicles currently consist of two-lighting type headlights with high beam and low beam lights, and commonly use dual filament bulbs, each bulb having a pair of high beam filament bulbs and a pair of low beam filament bulbs. Headlights on medium or higher class vehicles use four-lighting type headlights separately mounted with low beam light bulbs and high beam light bulbs.
The beams emitted from the low beam bulbs and high beam bulbs are reflected by a reflector mirror to be emitted to a front side of a vehicle and illuminate the front side of the vehicle by being adequately distributed.
However, the two-lighting type bulbs suffer from disadvantages in that lighting time is delayed due to repeated change of current between low beam bulbs and high beam bulbs to shorten the life of filaments, whereby a relevant lamp is not lighted when one of the filaments corresponding to the low beam bulbs or the high beam bulbs becomes out of order.
In order to solve the disadvantages thus mentioned, although a laser diode recently researched as one of light sources for headlights has an advantage of sending a beam of high brightness to a farther distance thanks to a smaller light emitting area, the laser diode suffers from various restrictions including a low JT (Junction Temperature, about 100° C.) as a vehicular part that requires reliability of high temperature.
It is therefore essential to constitute respective laser diode modules as many as the number of required light quantities in order to generate required light quantities for low beam bulbs and high beam bulbs respectively. Furthermore, the number of required modules must be minimized in order to save the cost, and to this end, the power applied to the laser diode must be maximally used, which however disadvantageously shortens the life due to increased JT of the laser diode. It is problematic that an inner temperature of a headlight is generally about 100° C., give or take.

Headlights having one light source module for a high beam and a low beam


The physical server includes a hypervisor for managing an association between the virtual server and the I/O device allocated to the virtual server. The I/O switch includes: a setting register for retaining a request to inhibit a transaction from being issued from the I/O device to the virtual server; a Tx inhibition control module for performing an inhibition of the transaction from the I/O device to the virtual server, and guaranteeing a completion of a transaction from the I/O device issued before the inhibition; a virtualization assist module for converting an address of the virtual server into an address within a memory of the physical server; and a switch management module for managing a configuration of the I/O switch.

This invention relates to an information processing system in which a server computer is connected with an I/O device through a PCI switch, in particular, a technique for virtualizing a server computer and migrating the virtualized server to another physical computer.
In recent years, against a backdrop of an increase in operation management costs due to an increase in the number of servers constituting an IT system and a performance boost for a physical server (physical computer) owing to a CPU multi-core and the like, attention is being given to a technique of server integration for reducing the number of physical servers by using a server virtualization technique for logically dividing one physical server into virtual servers to be operated.
There are several implementation methods for the above-mentioned server virtualization technique, among which a virtualization method using a hypervisor is known as being characterized in that overhead involved in virtualization is small (see, for example, 'Virtage' for 'BladeSymphony,' a Server Virtualization Feature which Improves Server Management Efficiency". July, 2007). The server virtualization method disclosed therein includes a hypervisor implemented as firmware for the physical server, and a virtualization assist function implemented as hardware. The hypervisor controls each of virtual servers (virtual computers) on the physical server, and the virtualization assist function converts an address for memory access made by the I/O device. In the server virtualization method disclosed in 'Virtage' for 'BladeSymphony,' a Server Virtualization Feature which Improves Server Management Efficiency", the hypervisor allocates an I/O device directly to the virtual server, and hence, the physical server and the virtual server can use the same OS environment. In addition, the hardware-based virtualization assist function performs an address conversion processing for the I/O device, and hence overhead on the address conversion processing involved in an I/O processing can be reduced, thereby improving I/O throughput.
On the other hand, a further performance boost for the physical server owing to the CPU multi-core and the like requires I/O throughput correspondent to performance of the physical server. Promising as a technique for improving the I/O throughput correspondent to the performance of the physical server is a PCI switch that can connect a plurality of I/O devices with respect to a plurality of physical servers.
Further, progress is being made toward standardization of an I/O virtualization technique for providing flexibility to an association between the virtual server and the I/O device by combining the above-mentioned server virtualization technique with the PCI switch (SR/MR-IoV (see Michael Krause, et al. "I/O Virtualization and Sharing". November, 2006)).
Against such a backdrop, an information processing system in which the server virtualization technique is combined with the PCI switch is regarded as becoming mainstream in the future.
Incidentally, a live migration is one of functions that enhance flexibility and availability of a computer system to which the server virtualization technique is applied (see Christopher Clerk, et al. "Live Migration of Virtual Machines". May, 2005, NSDI (Networked Systems Design and Implementation)'05).
The live migration is a function for migrating a running virtual server to another physical server. The live migration makes it possible to change a layout of running virtual servers depending on loads on the physical server and save a running virtual server from the physical server that needs maintenance. As a result, it is possible to enhance the flexibility and the availability of the system.
In a case where the live migration is realized in the above-mentioned information processing system in which the server virtualization technique is combined with the PCI switch, it is necessary to retain and take over three states of the running virtual server. The three states are an (a) CPU running state, a (b) memory content, and a (c) I/O device state. The (a) CPU running state can be retained when the hypervisor stops an operation of the virtual server.
However, a general hypervisor cannot stop memory access such as DMA made by the I/O device allocated to the virtual server or a processing for a transaction originated from an external I/O device, and therefore cannot retain the (b) memory content or the (c) I/O device state. Accordingly, in a case where the live migration is realized in the above-mentioned server virtualization technique, it is necessary to eliminate an influence of the running I/O device and retain the (b) memory content and the (c) I/O device state.
There exist several techniques for retaining those states.
Examples thereof include a method disclosed in US 2007/0186025 for a system having physical servers and I/O devices connected with each other through the PCI switch and managed by a PCI manager, in which in order to realize a migration of a virtual I/O device, a processing of a transaction from the I/O device during the migration is stopped.
In US 2007/0186025, the I/O device has a migration bit in its configuration space, and references the migration bit to judge whether or not a migration of the virtual I/O device is being performed.
If the migration is being performed, the I/O device stops its own processing, and inhibits an issuance of a transaction originated from the I/O device and bound for a memory. In addition, if the migration is being performed, the PCI manager saves the transaction within the PCI switch, which is originated from the I/O device and bound for the memory, to a specific storage area, and after the migration is completed, the transaction saved to the storage area is restored.
This prevents the transaction originated from the I/O device and being processed during the migration from rewriting the memory content, and prevents the I/O device state from being changed.
Meanwhile, U.S. Pat. No. 6,496,847 discloses a method in which a virtual server is provided with a device emulator obtained by a host OS emulating an I/O device, and a guest OS on the virtual server uses the device emulator to indirectly access the I/O device.
The host OS recognizes whether or not a migration is being performed, and if the migration is being performed, a processing of the device emulator is stopped to thereby allow the memory content and the I/O device state of the virtual server being migrated to be retained.

Method for switching I/O path in a computer system having an I/O switch


A cathode ray tube including (a) a panel having a fluorescent film on an inner surface thereof for three primary colors emission, (b) an electron gun for emitting electron beams to the fluorescent film, (c) a deflecting yoke located between the panel and the electron gun, and including first and second coils for generating horizontally and vertically deflected magnet fields, (d) at least one first compensator (34) composed of magnetic substance having high magnetic permeability and low hysteresis characteristic for compensating for a profile of magnetic flux density in the horizontally deflected magnetic field, and (e) at least one second compensator (35) composed of magnetic substance having hysteresis characteristic for keeping magnetization when a polarity of the horizontally deflected magnetic field is inverted. The first compensator compensates for misconvergence generated between a central electron beam and two electron beams between which the central electron beam is situated, and the second compensator compensates for misconvergence generated between the two electron beams. Thus, misconvergence is readily compensated for, ensuring qualified images on a screen.

1. Field of the Invention
The invention relates to a color cathode ray tube including an in-line type electron gun, and in particular, a color cathode ray tube which is capable of readily compensating for misconvergence.
2. Description of the Related Art
First, a structure of a conventional color cathode ray tube is explained below with reference to FIG. 1. The illustrated color cathode ray tube includes a bulb 1 comprised of a panel 1b, a neck portion 1c, and a funnel 1a, which has a truncated-conical cross-section and connects the panel 1b and the neck portion with each other.
A fluorescent filter film 2 is applied to an inner surface of the panel 1b. The flourescent film 2 includes flourescent materials for emission of three primary colors, which are separated from one another with photo-absorbing material sandwiched between them.
An in-line type electron gun 3 is installed in the neck portion 1c for emitting three electron beams to the flourescent film 2 to cause emission of three primary colors.
A deflecting yoke 4 is secured to the bulb 1 over the funnel portion 1a and the neck portion 1c. The deflecting yoke 4 is comprised of a bobbin 5 having a truncated-conical cross-section, a first coil 6 wound around the bobbin 5 for horizontally deflecting a magnetic field, a second coil 7 wound around the bobbin 5 for vertically deflecting a magnetic field, and a ferrite core 8 applied on an outer surface of the bobbin 5.
Though not illustrated, the color cathode ray tube further includes an inner shield in the funnel portion 1a, a shadow mask facing the flourescent film in the funnel portion 1a, and an aid such as a purity magnet in the neck portion 1c.
During operation, the electron gun 3 horizontally emits and accelerates three parallel electron beams, and deflects two other electron beams, between which a central electron beam is situated in such a manner that those two electron beams converge to the central electron beam.
Sawtooth current is supplied to each of the first and second coils 6 and 7, generating horizontally and vertically deflected magnetic fields.
The three electron beams emitted from the electron gun 3 enter the deflected magnetic fields, and are deflected to a degree proportional to the intensity of the magnetic fields. These three deflected electron beams are converged onto the flourescent film 2 to emit lights. As a result, colored images appear on the panel 1b.
In order to produce colored images having no color-misregistration, the three electron beams must be correctly directed to associated color regions in the fluorescent film 2.
However, it is quite difficult to make the deflected magnetic fields completely symmetrical in the bulb 1 because of a dispersion in the shape in the windings of the first and second coils 6 and 7, a dispersion in location of the first and second coils 6 and 7 when secured to the bobbin 5, a dispersion in the axis of the electron gun in the neck portion 1c, and/or a gap between axes of the deflecting yoke 4 and the electron gun 3. Accordingly, it is impossible to focus the three electron beams onto the fluorescent film 2, and the resulting misconvergence among the electron beams in turn results in misregistration of color on the fluorescent film 2.
This color misregistration considerably degrades the quality of images in a computer display. In order to prevent images from being degraded, the deflecting yoke 4 is set around the bulb 1 in a conventional cathode ray tube. A test pattern is displayed on the fluorescent film 2, and deflected magnetic fields generated by the deflecting yoke 4 are compensated for, so that the test pattern is displayed in a desired shape and in a desired color, and the generated images have no color misregistration.
Many attempts have been made to compensate for deflected magnetic fields. For instance, Japanese Unexamined Patent Publication No. 55-157846 suggests the deflecting yoke illustrated in FIG. 2. In the illustrated deflecting yoke, four magnetic pieces 9 are secured onto an outer surface of a bobbin 5. The magnetic pieces 9 are composed of iron alloy containing nickel as a principle ingredient (commercially available in the tradename of "PERMALLOY") and are equally spaced around the circumference of the bobbin 5. The magnetic pieces 9 improve coma-aberration on a screen, and compensate for color misregistration horizontally and vertically in three primary colors, red (R), blue (B), and green (G), as illustrated in FIG. 3.
Japanese Unexamined Patent Publication No. 8-115686 suggests a deflecting yoke for misconvergence. In the suggested deflecting yoke, illustrated in FIG. 4 , magnetic pieces 10 composed of magnetic material having high magnetic permeability, such as silicon steel and "PERMALLOY," are attached to an outer surface of the bobbin 5 in such a manner that the magnetic pieces are movable around the circumference of the bobbin 5.
Japanese Unexamined Patent Publication No. 9-45261 suggests a deflecting yoke as illustrated in FIG. 5. The illustrated yoke is formed with four slide rails 12 diagonally positioned reletive to the bobbin 5 at a rear end of the yoke. A magnetic piece 11 is supported along the slide rail 12. The magnetic pieces 11 are composed of silicon steel containing 3% silicon, or magnetic materials such as ferrite and amorphous providing the same effects as those of silicon steel. A part of the magnetic flux leaking out of the deflecting yoke is cut off by appropriately adjusting the magnetic pieces 11. As a result, a profile of magnetic flux density in the bulb 1 is adjusted, improving deformation of images.
As explained above, the conventional deflecting yokes can improve image deformation and/or color-misregistration that result from misconvergence.
If, as illustrated in FIG. 6A, a horizontally deflected magnetic field is asymmetrically distributed in the bulb 1 due to a dispersion in the shape in the windings of the first and second coils 6 and 7, a dispersion in location of the first and second coils 6 and 7 when secured to the bobbin 5, a gap between axes of the electron gun 3 and neck portion 1c, and/or a gap between axes of the deflecting yoke 4 and the electron gun 3, then a magnetic flux density in a horizontal direction also becomes asymmetrical, as illustrated in FIG. 6B with a solid line X1. Forces exerting on the electron beams R, G, and B also become asymmetric as a result.
Hence, an electron beam located at a distance S from the center at the right side receives a force from a magnetic field, a force which differs in magnitude from a force received by another electron beam located at the same distance from the center at the left side, and misconvergence is generated on the fluorescent film 2 between a central electron beam G and the other two electron beams 13B and 13R, as illustrated in FIG. 2C. In order to eliminate this misconvergence, it is necessary to adjust a profile of deflected magnetic flux in such a manner that a green bright line 13G, which is a reference line, is made closer to a bright blue line 13B or a red bright line 13R located inside or outside the green bright line 13G.
A horizontally deflected magnetic field is partially leaked outside the deflecting yoke 4. Therefore, if a magnetic piece having high magnetic permeability is positioned as a compensator in a leaked magnetic field at a rear of the deflecting yoke 4, the leaked magnetic flux is partially cut off, compensating for a profile of the magnetic flux in the bulb 1.
By moving the magnetic piece as a compensator, a profile of the magnetic flux density is differentially varied horizontally around the center when viewed from the panel 1b. As a result, the electron beams located at the distance S from the center receive the same magnitude force, which ensures elimination of misconvergence.
If a horizontally deflected magnetic flux is distributed asymmetrically out of a curve of the second order, as illustrated in FIG. 7A, misconvergence is generated between two electron beams sandwiching a central electron beam therebetween, as illustrated in FIG. 7B.
As illustrated in FIG. 7B, the blue and red electron beams, which sandwich a central electron beam, project two rectangles on the screen. A side of a rectangle overlaps a side of another rectangle, and the two rectangles cooperate with each other to put the red and blue bright lines 13R and 13B in optimal condition. However, vertical bright lines 13R and 13B located at a center of the screen are out of position.
In such a condition, even if a magnetic piece having high permeability is put in a leaked magnetic field and moved therein to vary a profile of a magnetic flux density in a bulb, it would be impossible to adjust a profile of magnetic flux density to be horizontally symmetric on a screen. If bright lines located at the center of the screen are overlapped, bright lines 13R and 13B, located at opposite sides, are offset with each other. As a result, any such adjustment ends up with the bright lines located at the opposite sides being incorrectly balanced.
In light of these problems, miconvergence can only be completely eliminated by means of other compensators (not illustrated) secured to the bulb, which brings about more problems with complicated adjustments and an increase in the number of compensation steps.

Color cathode ray tube with first and second magnetic compensators


A surface cleaning apparatus and method is disclosed for disbonding, removal and collection of undesired matter from product surfaces, particularly in controlled process environments. The apparatus includes a negatively chargeable staging surface for receipt thereat of a product having a surface or surfaces to be cleaned, a gas stream nozzle having an electron generation source, usually a negative ion source, adjacent to its outlet, and a positive electrostatic field generator having a collector surface spaced from the staging surface. The electrostatic field generator may optionally include pulse generating circuitry for generating pulsations of selected frequency within the positive electrostatic field. Controls are provided for selectively controlling negative charge at the staging surface, ion output, field strength and, when provided, field pulsation frequency.

Devices for ionizing air or air streams for electrostatic dust separation and/or dust collection at a charged collector have been heretofore suggested and/or utilized (see, for example, U.S. Pat. Nos. 2,650,672 and 4,811,159, and German Patent Nos. DE 3201835 A1 and DE 3528590 A1). Surface cleaning devices have also been heretofore suggested and/or utilized which provide for ionization adjacent to a surface to be cleaned, with blowers directed at the surface to dislodge particles, vacuums for suctioning away the dislodged particles being provided adjacent to the surface. Some such devices have included a charged attraction member associated with the vacuum (see U.S. Pat. Nos. 4,835,808, 4,198,061 and 4,751,759).
Such heretofore known devices have not, however, adequately addressed the problem of disbonding particles, including microorganisms, electrostatically held to a product surface, nor have such devices been configured for adaptability for use with a variety of products the surface or surfaces of which are to be cleaned. Further improvement in such devices which addresses the problem of electrostatic bonding, which provides adaptable to a variety of uses, and which avoids undue complexity, for example by elimination of vacuums and the like, could thus still be utilized.


The invention describes a foil of polymeric material comprising a plurality of patch portions and a grid portion arranged between said patches. Each patch portion is connected to the grid portion by means of one or more connecting elements. Each patch portion is separated from the grid portion in the X-Y plane by means of a release portion, said release portion having a tensile strength in the X-Y plane which is lower than the tensile strength of both said patch portions and said grid portion, such that—upon exertion of a tensile force between said patch portions and said grid portion—said foil ruptures preferentially at said release portion. The invention relates to a method for the production of cell-capture chips using said foil, and a cell capture chip produced by said method.

The integration of sensor chips in carrier plates, also referred to as microtitre plates, is of particular concern of the present invention. Embodiments of the chip may provide a so-called lab-on-a-chip device, which integrates laboratory functions onto a single chip. An assembly of such chips, which may comprise an array of a plurality of chips on a single carrier, is applicable in a method for determining and/or monitoring electrophysiological properties of ion channels in ion channel-containing structures, typically lipid membrane-containing structures such as cells, by establishing an electrophysiological measuring configuration in which a cell membrane forms a high resistive seal around a measuring electrode, making it possible to determine and monitor a current flow through the cell membrane. The chip is for example useful in a method for analysing the electrophysiological properties of a cell membrane comprising a glycocalyx. The chip may be used in or form part of an apparatus for studying electrical events in cell membranes, such as an apparatus for carrying out patch clamp techniques utilised to study ion transfer channels in biological membranes. In particular, with chips to be used in patch clamp techniques, good adhesion of the cell to the chip is required, so that a high-resistance seal can be obtained between the chip and the cell membrane (a "gigaseal").
A particular goal in this field has been cheap, disposable chips fabricated of polymeric material, instead of glass or silicon. However, the mechanical properties of polymeric materials are different to those of such materials, and polymeric materials are often not particularly suited to the manufacturing processes used for glass or silicon materials. In addition, polymeric material with a sufficiently high surface smoothness for establishing giga-seals has proven hard to obtain.
WO 03/093494 discloses a biochip for patch clamp detection. U.S. Pat. No. 6,899,800 describes a polymeric electrode for obtaining a gigaohm seal. WO02/059597 discloses a tight electrical seal between a cell and a surface. A mechanically compressible insulating layer is present on the carrier, which compensates for any debris trapped between the cell and the surface.
Manufacturing of chips has required time-consuming and expensive manufacturing techniques (due to the requirements of quality, cleanliness and small-scale for such devices). The present invention aims to overcome problems associated with known processes. In particular, the invention provides improved method for manufacturing of chips comprising polymeric material. In the present invention, macro-dimensional techniques and devices are used to manipulate nano-dimensional articles.

Integrated polymer foil, patch-clamp array and membrane valves


A plant support structure including a base support, an elongate staff member, a trunk attachment arrangement for releasably and flexibly connecting the projecting of said staff member to the trunk of the plant, and a mounting block for mounting the staff member on the base support so that the longitudinal axis of the angles inwardly over the base support for attachment to the plant above its center of mass to stabilize the plant.

This invention relates generally to plant supporting structures and more particularly to stands for supporting and displaying plants such as Christmas trees.
Stands for supporting and displaying Christmas trees have been available for many years. Examples of such prior art Christmas tree stands are illustrated in:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 4,569,151 Hoffbeck February 11, 1986 4,381,621 Eby May 3, 1983 4,307,540 Reisner December 29, 1981 3,119,585 Austenson January 28, 1964 2,904,292 Cloutheir September 15, 1959 2,502,040 Franklin March 28, 1950 2,617,617 Krastel et al. November 11, 1952 2,455,404 Brown et al. December 7, 1948 1,463,734 Ullrich July 31, 1923 ______________________________________
One type of tree stand, examples of which are disclosed in U.S. Pat. Nos. 2,455,404; 2,502,040 and 2,617,617 engage the tree trunk relatively close to the butt of the tree which is substantially below the center of mass of the tree. Moreover, the support area of the base on which the tree is carried is relatively small as compared to the diameter of the foliage of the tree. Such an arrangement is inherently unstable resulting the tree being easily tipped over. This condition may be further aggravated by the trunk having grown crooked or by foliage that is not distributed evenly about the trunk. Also, the branches adjacent the lower end of the tree usually had to be removed to provide the necessary clear area of the trunk to be engaged by the tree stand.
Other types of stands have extended the point of attachment of the stand to the up the tree trunk by extending one or more support members up from the base immediately adjacent the tree trunk. Such stands are shown in U.S. Pat. Nos. 1,463,734 and 3,119,585. The location of the support members made it difficult to find locations adjacent the tree trunk through the branches for the support members to pass without adversely affecting the overall shape of the tree.
Another type of stand, such as those shown in U.S. Pat. Nos. 2,904,292; 4,307,540 and 4,381,621, uses a support member which is displaced horizontally from the trunk of the tree and attached to the tree trunk through a horizontal member. Under the influence of the tree weight acting on the tree, the tree may tend to rotate about the vertical member toward a less stable condition. Also, where the trunk attaching means is attached rigidly about the trunk the ability of the tree to reach a point of free body equilibrium of the forces acting through its center of mass is prevented.