Steerable satellite antenna assemblies for satellite-to-ground links typically require high gain, low mass, and high reliability. One approach for a steerable satellite antenna assembly is to use a fixed feed source so as to eliminate performance degradations otherwise associated with a moving feed source. Performance degradations for a moving feed source typically include losses due to mechanical rotary joints, RF cable connectors, flexible waveguides, and lengthy cables associated with rotary actuators.
Steerable satellite antenna assemblies also need to avoid the “keyhole effect,” which is a physical limitation due to the orientation of the antenna rotation axis caused by a limited motion range of the actuators. The keyhole effect causes the antenna to momentarily disrupt communications when reaching its physical limitation so as to allow for the actuators to reposition before resuming steering.
One approach for a steerable satellite antenna assembly with a fixed antenna feed is disclosed in U.S. Pat. No. 6,492,955 to Amyotte et al. The antenna assembly includes a subreflector secured to a frame rotatably mounted on a support structure via a first motor, and an antenna feed located at a first focus of the subreflector for illuminating the same. The antenna feed is fixed to the structure and has a feed axis pointing at the subreflector. A parabolic reflector having a focus in common with a second focus of the subreflector to transfer the signal between the same, and a planar reflector is secured to the frame, and has a beam axis. The planar reflector is rotatably mounted on the frame via a second motor to transfer the signal between the parabolic reflector and a target. The antenna assembly includes a controller connected to the motors to steer at the target anywhere within a full spherical angular range.
Another approach for a steerable satellite antenna assembly with a fixed antenna feed is disclosed in U.S. Pat. No. 5,198,827 to Seaton. The antenna assembly includes an antenna feed structure for emitting electromagnetic radiation, and a subreflector for redirecting the emitted radiation. A main antenna reflector projects radiation redirected by the subreflector as an antenna beam. A mechanical arrangement rotates the subreflector about the rotation point.
Even in view of the above steerable satellite antenna assemblies, there is still a need for such assemblies to have a more compact geometry. Continued growth and demand for bandwidth has led to new commercial satellite constellations. For example, the O3b satellite constellation is deployed in a medium earth orbit (MEO) and the OneWeb satellite constellation is to be deployed in a low earth orbit (LEO). A more compact antenna assembly reduces the size and weight of the satellites, as well as costs. In addition, MEO and LEO satellites typically operate at a wider beam scanning range as compared to a traditional geosynchronous orbit. Consequently, another desirable attribute is for the compact antenna assemblies to also operate over a wider scanning range.


This invention relates to pre-lined art board sheet member, and more particularly to an art sheet member which is pre-lined for the preparation of printed advertising media.
In the preparation of advertising material for printed advertising, plain, unlined art board is used by the advertising artist to prepare lay-outs, and after approval by the advertiser, the completed advertising illustration and text. The completed advertising material is then submitted to the color separator who prepares film of the different color separations, which in turn is presented to the printer. The printer then places the different colored film into chases or vacuum frames for preparation of the color plates for the printing press.
The original borders, center lines, and fold lines are laid out upon the art board for each separate advertising material by the advertising artist. After the printer receives the color films, he must extend the various border center lines and other lines upon the film for registration with his printing plates, in order for the artwork to properly register on the printed pages. A certain amount of time must be spent by the artist for each different advertising lay-out, just for placing the border and center lines upon the art board. Drawing and sketch lines are frequently changed upon the art board, requiring erasure and smudging.
Moreover, because the artist has to measure and draw the border, center lines and fold lines for each new advertising creation, errors are frequently made which continue into the completed advertising material. Such errors can be quite expensive causing complete re-printing of numerous pages of advertising material, re-assembly of the print chases and printing plates, and even re-preparing the lay-outs and completed advertising drawings. Such errors can create considerable amounts of wasted time and money, as well as missed deadlines.


Treats and chews are given to dogs for a variety of reasons. Chews are used to occupy the dog and help clean its teeth. Treats may have the same cleaning function, as well as provide some nutritional value.
Treats and chews can be made from a variety of materials. For example, the products can be made of processed, dried animal skin, such as rawhide (untanned cattle skin) or pigskin. The skin is processed by removing hair and cleaning it of fat and muscle. The skin is then manipulated into the desired shape, such as by folding or rolling, and then dried.
In the prior art, treats and chews can be made of materials other than hide. For example, the products can be made of plastic, rubber, etc.
Even when dogs chew on treats and chews, their breath may have an unpleasant odor and their teeth may not be cleaned. For example, on a rawhide chew, a dog has a hard time piercing the tough dried skin with its teeth. Thus, the teeth are not cleaned and the dog continues to have bad breath.


1. Technical Field
The present invention relates to computer and digital data compression, and more specifically to preventing rounding errors that can accumulate in MPEG-2 type decompression.
2. Description of the Prior Art
Digitized images require a large amount of storage space to store and a large amount of bandwidth to transmit. A single, relatively modest-sized image, having 480 by 640 pixels and a full-color resolution of twenty-four bits per pixel (three 8-bit bytes per pixel), occupies nearly a megabyte of data. At a resolution of 1024 by 768 pixels, a 24-bit color screen requires 2.3 megabytes of memory to represent. A 24-bit color picture of an 8.5 inch by 11 inch page, at 300 dots per inch, requires as much as twenty-five megabytes to represent.
Video images are even more data-intensive, since it is generally accepted that for high-quality consumer applications, images must occur at a rate of at least thirty frames per second. Current proposals for high-definition television (HDTV) call for as many as 1920 by 1035 or more pixels per frame, which translates to a data transmission rate of about 1.5 billion bits per second. This bandwidth requirement can be reduced somewhat if one uses 2:1 interleaving and 4:1 decimation for the xe2x80x9cUxe2x80x9d and xe2x80x9cVxe2x80x9d chrominance components, but 0.373 billion bits per second are still required.
Traditional lossless techniques for compressing digital image and video information, such as Huffman encoding, run length encoding and the Lempel-Ziv-Welch algorithm, are far from adequate to meet this demand. For this reason, compression techniques which can involve some loss of information have been devised, including discrete cosine transform techniques, adaptive discrete cosine transform techniques, and wavelet transform techniques. Wavelet techniques are discussed in DeVore, Jawerth and Lucier, Image Compression Through Wavelet Transform Coding, IEEE Transactions on Information Theory, Vol. 38, No. 2, pp. 719-746 (1992); and in Antonini, Barlaud, Mathieu and Daubechies, Image Coding Using Wavelet Transform, IEEE Transactions on Image Processing, Vol. 1, No. 2, pp. 205-220 (1992).
The Joint Photographic Experts Group (JPEG) has promulgated a standard for still image compression, known as the JPEG standard, which involves a discrete cosine transform-based algorithm. The JPEG standard is described in a number of publications, including the following incorporated by reference herein: Wallace, The JPEG Still Picture Compression Standard, IEEE Transactions on Consumer Electronics, Vol. 38, No. 1, pp. xviii-xxxiv (1992); Purcell, The C-Cube CL550 JPEG Image Compression Processor, C-Cube Microsystems, Inc. (1992); and C-Cube Microsystems, JPEG Algorithm Overview (1992).
An encoder using the JPEG algorithm has four steps: linear transformation, quantization, run-length encoding (RLE), and Huffman coding. The decoder reverses these steps to reconstitute the image. For the linear transformation step, the image is divided up into 8*8 pixel blocks and a Discrete Cosine Transform is applied in both spatial dimensions for each block. The purpose of dividing the image into blocks is to overcome a deficiency of the discrete cosine transform algorithm, which is that the discrete cosine transform is seriously non-local. The imager is divided into blocks in order to overcome this non-locality by confining it to small regions, and doing separate transforms for each block. However, this compromise has a disadvantage of producing a tiled appearance (blockiness) upon high compression.
The quantization step is essential to reduce the amount of information to be transmitted, though it does cause loss of image information. Each transform component is quantized using a value selected from its position in each 8*8 block. This step has the convenient side effect of reducing the abundant small values to zero or other small numbers, which can require much less information to specify.
The run-length encoding step codes runs of same values, such as zeros, in items identifying the number of times to repeat a value, and the value to repeat. A single item like xe2x80x9ceight zerosxe2x80x9d requires less space torepresent than a string of eight zeros, for example. This step is justified by the abundance of zeros that usually result from the quantization step.
Huffman coding translates each symbol from the run-length encoding step into a variable-length bit string that is chosen depending on how frequently the symbol occurs. That is, frequent symbols are coded with shorter codes than infrequent symbols. The coding can be done either from a preset table or one composed specifically for the image to minimize the total number of bits needed.
Similarly to JPEG, the Motion Pictures Experts Group (MPEG) has promulgated two standards for coding image sequences. The standards are known as MPEG-1 and MPEG-2. The MPEG algorithms exploit the common fact of relatively small variations from frame to frame. In the MPEG standards, a full image is compressed and transmitted only once for every twelve frames. The JPEG standard is typically used to compress these xe2x80x9creferencexe2x80x9d or xe2x80x9cintraxe2x80x9d frames. For the intermediate frames, a predicted frame is calculated and only the difference between the actual frame and the, predicted frame is compressed and transmitted. Any of several algorithms can be used to calculate a predicted frame, and the algorithm is chosen on a block-by-block basis depending on which predictor algorithm works best for the particular block. Motion detection can be used in some of the predictor algorithms. MPEG 1 is described in detail in International Standards Organization (ISO) CD 11172.
Accordingly, for compression of video sequences the MPEG technique is one which treats the compression of reference frames substantially independently from the compression of intermediate frames between reference frames. The present invention relates primarily to the compression of still images and reference frames for video information, although aspects of the invention can be used to accomplish video compression even without treating reference frames and intermediate frames independently.
The above techniques for compressing digitized images represent only a few of the techniques that have been devised. However, none of the known techniques yet achieve compression ratios sufficient to support the huge still and video data storage and transmission requirements expected in the near future. The techniques also raise additional problems, apart from pure compression ratio issues. In particular, for real time, high-quality video image decompression, the decompression algorithm must be simple enough to be able to produce thirty frames of decompressed images per second. The speed requirement for compression is often not as extreme as for decompression, since for many purposes, images can be compressed in advance. Even then, however, compression time must be reasonable to achieve commercial objectives. In addition, many applications require real time compression as well as decompression, such as real time transmission of live events. Known image compression and decompression techniques which achieve high compression ratios, often do so only at the expense of requiring extensive computations either on compression or decompression, or both.
The MPEG-2 video compression standard is defined in ISO/IEC 13818-2 xe2x80x9cInformation technologyxe2x80x94Generic coding of moving pictures and associated audio information: Videoxe2x80x9d. MPEG-2 uses motion compensation on fixed sized rectangular blocks of pixel elements (xe2x80x9cmacroblocksxe2x80x9d) to use temporal locality for improved compression efficiency. The location of these xe2x80x9cmacroblocksxe2x80x9d in the reference pictures is given on half pixel boundaries, and so requires an interpolation of pixel elements. Such interpolation is specified in the MPEG-2 standard, as follows:
The xe2x80x9c//xe2x80x9d operator at the ends of cases B, C, and D is defined in the MPEG-2 specification as: xe2x80x9cInteger division with rounding to the nearest integer. Half-integer values are rounded away from zero unless otherwise specified [ . . . ]xe2x80x9d. Therefore, when a two or a four are the right hand operand and the left hand operand is greater or equal zero, the operator xe2x80x9c//xe2x80x9d can be replaced according to: x//2=(x+1) greater than  greater than 1; x//4=(x+2) greater than  greater than 2, where xe2x80x9c greater than  greater than xe2x80x9d denotes a binary right shift of the left hand operator by the right hand operator designated number of bits.
Since xe2x80x9cavg(p00, p01):=(p00, p01)//2=(p00, p01+1) greater than  greater than 1xe2x80x9d is a simple operation to implement on a microprocessor, many commercial microprocessors include this operation as a built-in instruction. For example, xe2x80x9cpavgusbxe2x80x9d is included in Intel processors with the SSE extension, and AMD processors with the 3DNow! extensions. Such instruction is very useful in computing cases B and C, above.
The built-in xe2x80x9cpavgusbxe2x80x9d instruction is very tempting for use in implementing case-D, e.g., by executing it twice, as in xe2x80x9cavg(avg(p00, p01), avg(p10, p11))xe2x80x9d. This is also an interesting alternative for a pure hardware implementation, because the circuit to implement the first step of averaging can also be used a second time to do the second step. But to do so, will generate objectionable visual artifacts.
The usual sub-routine to implement case-D requires the execution of twenty-seven instructions, as is listed in the left column of Table I. But if xe2x80x9cpavgusbxe2x80x9d is used, the sub-routine can be reduced to five instructions, as is listed in the right column of Table I. So the temptation to use the quicker solution for case-D is very great.
One problem with the shortcut solution is that it causes, artifacts because rounding is handled different, than the MPEG standard dictates. So to have artifact-free implementations, the short-cut solution is prohibited.
The rounding error for a specific combination of four pixels can be calculated as:
err(p00, p01, p10, p11)=((((p00+p01+1) greater than  greater than 1)+((p10+p11+1) greater than  greater than 1)+1) greater than  greater than 1)xe2x88x92((p00, p01+p10+p11+2) greater than  greater than 2)
The overall error is only affected by the two least significant bits of each coefficient, so the total average error can be calculated as:   avgerr  =                                          xe2x80x83                                                        xe2x80x83                                      i              =              0                        3                                                        xe2x80x83                                                                        xe2x80x83                                                                            xe2x80x83                                                  j                  =                  0                                3                                                                xe2x80x83                                                                  xe2x80x83                                                                            xe2x80x83                                                  k                  =                  0                                3                                                                xe2x80x83                                                                  xe2x80x83                                                                            xe2x80x83                                                  l                  =                  0                                3                                                                err                                            (                                  i                  ,                  j                  ,                  k                  ,                  l                                )                                                                4        ?        4        ?        4        ?        4              =                  3        8            .
The rounding error is less than one least-significant-bit for first-generation compensation, and is not a problem. But the MPEG-2 standard allows for multi-generation compensation. The consequence of this is a predicted picture can be used as a reference picture for successive pictures. When a predicted picture is used as a reference picture, rounding errors can add up to more than one least significant bit, and the accumulated rounding errors can be large enough over several compensation generations to create objectionable visual artifacts.
Such visual artifacts or optical effects are called xe2x80x9cpumpingxe2x80x9d, and are perceived by the eye as image brightening over a series of predicted pictures that jump back to normal brightness at the next intra-picture. In particular, sequences that have an unusually high number of predicted pictures between intra codes pictures can experience serious pumping. For example, field structure encoded sequences or material that lack xe2x80x9cbi-directionalxe2x80x9d predicted pictures will suffer from pumping.
The invention comprises a method wherein two-step motion prediction errors for MPEG-2 interpolation case-D are corrected. An improved MPEG-2 decoder includes a logic gate, multiplexer, and adder. When both the horizontal (h0) and vertical (h1) motion vector components require a half pixel interpolation (case-D), the multiplexer forwards the constant minus three to the adder, otherwise a constant zero is used. Such adder modifies the D C coefficient input to the inverse discrete cosine transformer to include a correction term for the predicted pixels calculated by a two-step predictor. A correction value of xe2x88x920.375 is evenly distributed over all sixty-four resulting spatial coefficients during the inverse discrete cosine transform. This results statistically in a slightly brighter set of correction terms. Such offsets a slightly darker prediction that are formed by the two-step predictor. The output frames are statistically correct images.


1. Field
At least one example embodiment relates to a backlight unit, a display device including the backlight unit, and/or a method of manufacturing the backlight unit.
2. Description of the Related Art
In general, a three-dimensional (3D) image is configured based on stereo view principles using two eyes of a person. A 3D image display may be a stereoscopic display and an autostereoscopic display. The autostereoscopic display acquires a 3D image by separating an image into a left image and a right image without using glasses, and uses, for example, a parallax barrier method and/or a lenticular method.
Here, in the case of the parallax barrier method and/or the lenticular method, once a design is completed, the design may not be readily modified, optical efficiency may be low, and a crosstalk between a left image and a right image may be relatively high. In addition, some autostereoscopic displays employing the parallax barrier method and/or the lenticular method do not readily achieve a two-dimensional (2D) display. Alternatively, even if an autostereoscopic display employing the parallax barrier method and/or the lenticular method is capable of achieving the 2D display, the quality of a 2D image may be degraded.


This invention relates to a magnetic recording and optical reproducing apparatus in which a magneto-optical effect is utilized so as to reproduce information magnetically recorded on a recording medium by applying a recording magnetic field from a magnetic head.
It has been confirmed that an information bit length as short as 0.1 .mu.m in terms of a linear bit density can be recorded on a recording medium according to a recording method in which a recording magnetic field generated from a magnetic head is used to magnetically record information on the recording medium, as described in, for example, IEEE TRANSACTIONS ON MAGNETICS, VOL. MAG-23, No. 5, SEPTEMBER 1987, page 2070."
On the other hand, a method utilizing a magneto-optical effect for the high-sensitivity reproduction of information magnetically recorded on a recording medium is described in, for example, JP-A-55-153142.


1. Field of the Invention
The present invention relates to a composition for forming an antireflection film (an antireflection film-forming composition) suitable for microfabrication using a lithography process, in which a resist responding to various radiations such as a chemically amplified resist is used, a laminate with an antireflection film formed from the antireflection film-forming composition on a resist film, and a method for forming a resist pattern using the antireflection film-forming composition.
2. Description of Background Art
In the field of microfabrication represented by fabrication of integrated circuit devices, the processing size has become more and more minute in order to achieve higher integration in a lithographic process. In recent years, development of a lithographic process enabling stable microfabrication with a line width of 0.5 μm or less has been actively proceeding.
However, it is difficult to form such a fine pattern with high accuracy using a conventional method which utilizes visible rays (wavelength: 800-400 nm) or near ultraviolet rays (wavelength: 400-300 nm). To deal with this problem, a lithographic process using radiation with a shorter wavelength (wavelength: 300 nm or less) which can achieve a wider depth of focus and is effective for ensuring design rules with minimum dimensions has been proposed.
As a lithographic process using radiation with such a short wavelength, processes using deep ultraviolet rays such as a KrF excimer laser (wavelength: 248 nm) or an ArF excimer laser (wavelength: 193 nm), X-rays such as synchrotron radiation, and charged particle rays such as electron beams have been proposed. A chemically-amplified resist has attracted attention as a resist exhibiting high resolution for such short wavelength radiation. At present, development and improvement of the chemically amplified resist are important technical issues of the lithographic process.
The chemically-amplified resist contains a compound (a photoacid generator) which generates an acid upon irradiation (hereinafter called “exposure”). Chemical changes in the resist film (changes in polarity, breakage of a chemical bond, cross-linking reaction, etc.) caused by the catalytic action of an acid change solubility of the exposed area in a developer. A pattern is formed utilizing this phenomenon.
A number of compositions for chemically-amplified resists, for example, a combination of a resin containing an alkali-soluble resin, in which the groups exhibiting affinity with an alkali are protected by a t-butyl ester group or t-butoxy carbonyl group, with an acid generator (for example, Japanese Patent Publication No. 59-45439), a combination of a resin containing an alkali-soluble resin, in which the groups exhibiting affinity with an alkali are protected by a silyl group, with an acid generator (for example, Japanese Patent Publication No. 60-52845), a combination of an acetal group-containing resin with an acid generator (for example, Japanese Patent Publication No. 2-25850), a combination of an alkali-soluble resin, a dissolution controller, and an acid generator, a combination of a novolac resin, a crosslinking agent, and an acid generator; and the like have been proposed.
These chemically-amplified resists, however, have a problem with storage stability, because the compositions are easily affected by moisture, oxygen, basic substances, and the like which are present in the atmosphere of the lithographic process. SPIE, Vol. 1466, “Advance in Resist Technology and Processing”, p. 2 (1991), for example, reports that a very small amount of dimethylaniline in the atmosphere deactivates acids existing near the surface of a resist film among the acids produced in the resist film by exposure, and forms a scarcely soluble layer on the surface of the film, which layer remains in the form of an eave-like projection on the surface of a resist pattern after development. Not only such a scarcely soluble layer decreases sensitivity and resolution of the resist, but also the eave-like projections formed in the resist pattern adversely affect the etching accuracy. The size of the eave-like projections tends to increase along with an increase of the time for which the resist is allowed to stand between each of the steps of exposure, post exposure baking, and development. This phenomenon is known as post exposure time delay (hereinafter referred to as “PED”), which unduly decreases the allowance of time in the lithographic process.
As a method for solving the problem of PED, a method of laminating an overcoat on the chemically-amplified resist film to block the film surface from the atmosphere has been proposed. For example, WO 92/05474 describes a method of laminating an overcoat of polyacrylic acid, polyvinyl butyral, polyvinyl alcohol, polystyrene sulfonic acid, or the like on the chemically-amplified resist film to inhibit invasion of basic materials into the resist film, thereby preventing a decrease of sensitivity and resolution of the resist. However, among such overcoats, polyacrylic acid, polyvinyl butyral, and polyvinyl alcohol cannot necessarily effectively prevent formation of the aforementioned scarcely-soluble layer, although they have a barrier effect. Polystyrene sulfonate, which has too strong acidity, has a drawback of initiating a chemical reaction due to the catalytic action of the acid in the chemically-amplified resist irrespective of exposure to light. Another problem of the overcoat, which is commonly applied to a resist film as an aqueous solution, is uneven coating due to insufficient wetting properties of the aqueous solution with the resist film.
On the other hand, since radiation commonly used in the lithographic process is light with a single wavelength, incidence radiation interferes with light reflected by the boundary surfaces on the top and bottom of the resist film. As a result, a phenomenon called “a standing-wave effect” or “a multiplex interference effect”, which is a phenomenon in which an effectual dose of radiation to which a resist film is exposed fluctuates due to mutual interference of radiations in the film according to fluctuation of the resist film thickness, irrespective of a constant actual dose of radiation, occurs and adversely affects formation of resist patterns. If the coating thickness varies due to slight difference of a resist composition, viscosity, resist film conditions, and the like, or the coating thickness fluctuates due to steps in the substrates (recessed parts are thicker than projected parts), such a film thickness difference changes the effectual dose of radiation to which a resist film is exposed, resulting in fluctuation of pattern dimensions and a decrease in accuracy of the resist pattern dimensions.
To overcome this problem caused by the standing-wave effect, a method of forming an antireflection film on the resist film to inhibit reflection on the coating surface and reduce multiplex interference in the film has been proposed. For example, a method of reducing the standing-wave effect by laminating layers of polysiloxane, poly(ethyl vinyl ether), polyvinyl alcohol, or the like as an antireflection film on a resist film is described in J. Electrochem. Soc., Vol. 137, No. 12, p. 3,900 (1990). In this instance, the reflex inhibition effect on the surface of the resist film mainly depends on the refractive index and film thickness of the antireflection film. The refractive index of an ideal antireflection film is the square root of n (n is the refractive index of the resist), and the thickness of an ideal antireflection film is an anisoploid of λ/4 m (wherein λ is the wavelength of radiation and m is the refractive index of the antireflection film).
However, the antireflection film made from polysiloxane, poly(ethyl vinyl ether), or polyvinyl alcohol has a basic problem of being incapable of sufficiently inhibiting the standing-wave effect due to the small difference of the refractive index with that of a resist film. In addition, the antireflection film made from polysiloxane which is insoluble in water or a developer must have a separate step of removing the antireflection film before development using an antireflection film removing agent. The solubility in water or a developer of poly(ethyl vinyl ether) or polyvinyl alcohol is not necessarily sufficient. The antireflection film made from these polymers may leave residues on the resist film which impair resist performance such as resolution, developability, pattern profile, and the like. An additional problem of the overcoat which is applied to a resist film as an aqueous solution such as poly(ethyl vinyl ether) or polyvinyl alcohol is uneven coating due to insufficient wetting properties of the aqueous solution with the resist film.
In order to solve the problems in conventional antireflection films mentioned above, the inventor of the present invention has proposed (a) a copolymer of an acrylamide compound such as 2-acrylamide-2-methylpropane sulfonic acid in which the amide group has a sulfonic acid group bonded to the nitrogen atom via an organic group, and a fluoroalkyl acrylate compound such as 2,2,3,3,3-pentafluoropropyl acrylate and (b) a basic material blocking antireflection film containing a fluoroalkylsulfonic acid having an fluoroalkyl group with 5-15 carbon atoms and/or a fluoroalkylcarboxylic acid having an fluoroalkyl group with 5-15 carbon atoms, and a resist pattern forming method using the antireflection film (see Japanese Patent Application Laid-open No. 7-234514). This antireflection film can reduce the effect of a basic substance in the atmosphere and the standing-wave effect. However, the composition used for forming the antireflection film has a problem in coatability onto a resist film, which results in production of micro-bubbles in the order of micrometers in the formed coating.
An object of the present invention is to provide an antireflection film-forming composition having excellent coatability, capable of significantly inhibiting production of fine micro-bubbles and capable of forming an antireflection film with a sufficiently decreased standing-wave effect, and having excellent solubility in water and alkaline developers, a laminate with an antireflection film formed from the antireflection film-forming composition on a resist film, and a method for forming a resist pattern using the composition for forming a basic material blocking antireflection film.


A. Field of the Invention
The present invention relates to a new and improved game apparatus for setting up elongated objects, such as dominos, in predetermined configurations.
B. Description of the Prior Art
Both children and adults enjoy setting up objects such as dominos in predetermined configurations and then through a chain reaction, causing the dominos to fall over sequentially and while falling over, to initiate an entertaining series of events. Not only are dominos set up in this manner for pleasure at home, but there are also contests and groups of people that get together to set up large chains of dominos over a large area and in many different configurations. Apparatus for use in conjunction with such play is described in U.S. Pat. Nos. 3,283,439, 3,283,440, 3,315,404, 3,621,601, 4,047,322 and 4,248,433.
One problem, however, is that often times an individual does not have the ability or the patience to place the dominos in very long, unusual and entertaining configurations. Often the tedium involved in setting up the dominos, an operation which is extremely delicate and often requires repeated efforts to set up an array without accidentally initiating a chain reaction, may exceed the potential enjoyment. Moreover, it would be desirable to have mechanical means for starting and signaling the finish of the chain reaction of falling dominos. It is also desirable to have several different devices in the path of the falling dominos to create different actions and then to continue the chain reaction of the falling dominos onto another chain of dominos. Such items are lacking in the prior art.


Electronically controlled machine tools and computer aided manufacturing software together may be utilized to create and/or form a manufactured component. This process often may include forming one or more features, such as holes, threaded holes, and/or slots, in a workpiece to transform the workpiece into at least a portion of the manufactured component.
Historically, programming an electronically controlled machine tool to form the feature has been a labor-intensive process in which the computer aided manufacturing software is utilized to describe each feature that is to be formed in the workpiece in detail. This process often becomes highly repetitive, especially when a plurality of similar features is to be formed in the workpiece.
In addition, newly designed cutting tool formations are continually being developed for more efficient processes for the formation of certain features. Current computer aided manufacturing software algorithms are not always capable of producing the most efficient or applicable tool path motion for a given cutting tool. The current computer aided manufacturing software algorithms also may cause significant and/or uneven wear of a cutting tool that is utilized to form the feature and/or may require that one or more manual machining operations be performed to ensure the integrity of the feature. As an example, machining a threaded hole with an electronically controlled machine tool may include drilling a hole into the workpiece and subsequently threading the hole to define the threaded hole. The machining process may utilize a combination cutting tool consisting of a drill, a thread mill, and a chamfer in one application. This combination tool is required to extend from an entrance of the hole into the hole to define the minor diameter of the threads within the hole and to chamfer the top of the hole at a specific surface feed rate. The combination tool then forms the threads of the threaded hole at a different surface feed rate. In such a machining operation, an endmost drilling portion of the tool removes a majority of the material, with a remainder of the combination tool, which includes a threading portion and a chamfering portion, removing less of the material. Thus, endmost thread milling cutters of the combination tool generally wear at an accelerated rate relative to a remainder of the combination tool. This may require that the combination tool be sharpened and/or replaced frequently and/or may require that the threaded hole be manually chased with a tap subsequent to formation of the threaded hole by the electronically controlled machine tool. Current tool path algorithms within computer aided manufacturing software do not have the capability to utilize such a combination tool in an optimal fashion and limit user control. Thus, there exists a need for associative templates, which may be defined by user inputs, for machining operations and/or for systems and/or methods that include and/or utilize the associative templates and thus may not limit the user to existing computer aided software algorithms and/or may decrease and/or eliminate repetitive tool motions when forming the feature.


The invention relates to a method and apparatus for applying liquids to plants. While the apparatus according to the present invention may be utilized to apply a wide variety of chemicals to plants, the apparatus and method are particularly suited for the application of liquid contact herbicides, such as ROUNDUP manufactured by Monsanto Company, to weeds.
Weed control in growing crops is a continuing problem in agriculture, and a great deal of research has been done in that area and there have been many prior art proposals and procedures for the chemical treatment of weeds. Often times one particular structure is utilized for spraying herbicides in the crop rows between plants, and then another structure is utilized for contacting weeds taller than the crop plants.
Conventional overhead herbicide applicators include recirculating sprayers and rope wick applicators. Both structures can be successful if properly utilized, however recirculating sprayers are quite complex with a tendency to clog, and conventional rope wick applicators can apply less than the desired amount of herbicide to plants unless operating parameters are entirely appropriate. Further, neither system is readily adaptable to between row usage.
According to the method and apparatus of the present invention, a rotating roller is utilized as a primary herbicide-applying component. While the utilization of rotating rollers per se has previously been proposed, such proposed structures conventionally have dripped herbicide onto rollers directly in contact with the ground and have been adapted to be rolled over the ground. Such structures therefore have limited utility for the application of herbicide to weeds adjacent crop rows. According to the present invention, a rotating liquid applicator roller is readily utilizable for applying herbicide simply and effectively to weeds between crop rows and to weeds growing above crop rows with equal efficiency. The apparatus according to the invention is readily adapted for mounting to a tractor tool bar, or to be pushed by hand.
According to the method of the present invention, a liquid applicator roller is mounted for rotation about a generally horizontal axis and in operative communication with a reservoir of liquid herbicide. The method includes the steps of: Mounting the applicator roller above the ground and in a position for the peripheral surface thereof to be brought into contact with plants. Effecting movement of the applicator roller in a direction generally perpendicular to the axis of rotation of the roller. And, effecting powered rotation of the applicator roller so that it rotates into contact with plants and continuously transfers liquid from the surface thereof onto the plants, the surface being continuously replenished with liquid from the reservoir. Preferably rotation of the roller is effected in a direction of rotation so that it rotates into plants with which it comes into contact, providing a thorough wiping effect of herbicide onto the plants. The method may be practiced by moving the roller just above ground level between rows of crops, while positively preventing the roller from contacting crops in the rows on either side thereof; or by moving the roller above the tops of the crop plants to contact any plants extending upwardly above the tops of the crop plants.
The apparatus according to the invention includes a liquid applicator roller and a liquid reservoir and means for transferring liquid from the reservoir to the applicator roller surface. The applicator roller preferably comprises a tube of hard plastic having the ends thereof capped with spindles extending outwardly therefrom to define the axis of rotation of the roller. A housing mounts the roller for rotation about a given axis while covering the roller at the top and sides but being open at the bottom to allow the peripheral surface of the roller to rotate out of the housing. The housing also mounts the liquid transferring means. Means are provided for mounting the housing and the roller applicator above the ground, with the axis of rotation of the applicator roller generally horizontal. Preferably a drive wheel is provided, and means are provided for mounting the drive wheel to the housing so that it is rotatable about an axis parallel to the axis of rotation of the applicator roller, with surface means formed on the applicator roller and drive wheel effecting rotation of the applicator roller in response to the rotation of the drive wheel. Preferably the direction of rotation of the applicator roller is opposite to the direction of rotation of the drive wheel.
When the drive wheel is utilized, it is mounted to one side of the housing while the other side of the housing is either mounted to the tractor tool bar or to a pair of ground engaging wheels. Horizontally spaced and elongated plates mounted to the housing adapt the housing for mounting either to a tool bar or to ground engaging wheels. Where a drive wheel is not utilized, the applicator roller may be powered by a motor mounted on a tractor.
A liquid pool is defined within the housing substantially the entire width thereof, corresponding to the applicator roller length. The level of liquid in the pool is substantially even with the axis of rotation of the applicator roller. Transfer of liquid from the pool to the roller may be effected utilizing a sponge, or a pair of transfer rollers. Where the apparatus is utilized between crop rows, preferably a wiper is provided mounted to the housing to wipe any liquid off the roller periphery after plant contact and before a given portion of the roller rotates back into the housing through the housing open bottom. A more remote liquid reservoir may be provided, with a conduit leading from the liquid reservoir to the pool and with a level-responsive valve located in association with the conduit.
It is the primary object of the present invention to provide a method and apparatus for simply, efficiently, and effectively applying a liquid to plants, and particularly for applying a liquid herbicide. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.


Businesses that offer services to large numbers of people often have access to large amounts of sensitive information. For example, many businesses perform thousands or millions of credit card transactions each year. Credit card information is just one example of sensitive information that many companies handle as part of providing a service. Often times, large amounts of data must be stored and accessed quickly as part of providing services involving sensitive information.
Currently existing methods for storing and accessing large amounts of sensitive information have disadvantages. Typically, when the information includes millions of records, the information is stored by a unique number, for example by consecutively numbered records This allows for easy storage, but accessing the information at a later date can be time consuming when there are large numbers of records, for example in the millions.
It is important for businesses to be able to quickly store and access any record of a large amount of records including sensitive information such as credit card information.


This invention relates to electric networks, and more particularly it relates to a phase sequence network or filter, responsive to selected symmetrical components of current in a polyphase alternating current electric power circuit.
The theory of symmetrical components is well understood by those skilled in the art of electric power transmission and distribution. In accordance with this theory, the phase currents or voltages in any unbalanced three-phase alternating-current electric circuit can be resolved into three sets of symmetrical, balanced current or voltages vectors known respectively as positive sequence, negative sequence and zero sequences components. The negative and zero sequence components of circuit current and voltage are not present under balanced circuit conditions. A more detailed discussion of the theory of symmetrical components can be found in the textbook, Symmetrical Components, by Wagner and Evans, published by McGraw-Hill in 1933.
It has been known that certain circuits, called sequence networks or filters, can be connected to an electric power system to provide an output signal that is proportional to the magnitude of the negative sequence components of current. These sequence networks or filters are particularly useful in the protective relaying art as they will sense the presence of negative sequence components of current which flow when the power system becomes unbalanced due to abnormal of fault conditions. It has also been known in the protective relaying art that it is desirable to have a sequence network that has a "mixed" response, that is, the output is a function of both the positive sequence components of current and the negative sequence components of current. One of the disadvantages of the prior art sequence networks that have a mixed response is that when the circuit values are adjusted to change the circuit response to the positive sequence components, the circuit's response to the negative sequence components also changes. I have found it desirable to have a sequence network in which the positive sequence response can be selectively varied without affecting the amplitude or phase of the circuit's response to the negative sequence components.
The output of the sequence sensitive circuit is a sine wave which generally must be further processed to derive a d-c control signal. Since the processing of the sine wave signal usually involves some filtering which delays the detection of the fault condition, it is desirable to keep the filter as small as possible.
It is, therefore, one object of this invention to provide a sequence network, responsive to both the positive sequence components and negative sequence components of a three phase alternating current power system, in which the response to the positive sequence components can be selectively varied without affecting the response to the negative sequence components.
It is another object of this invention to provide a mixed sequence responsive circuit in which the positive sequence response is 180.degree. out of phase with the negative sequence response.
Another object of this invention is to reduce the filtering required to derive a control signal from the sine wave output of a sequence sensitive circuit.


The sport of towing a rider on a water planing device behind a boat is well known. The types of devices may generally be divided into the categories of water skis and water planes or aquaplanes. In the categories of water skis the advantages of control and versatility are available. However, water skiing requires a development of sufficient strength to hold onto a tow rope while maintaining the skis in a parallel relationship and standing erect while doing both. This makes waterskiing a difficult and often frustrating sport for the beginner, requiring the simultaneous development of arm strength, leg strength and balance.
Water planes are generally a single flat, wide board on which the rider stands. In some versions, for example the water sports vehicle disclosed in U.S. Pat. No. 3,581,328 of Smith, the problem of direct force on the rider from the tow rope is alleviated by connecting the tow rope to the front of the vehicle and having a handle extending from the front for the rider to hold for stability without requiring a great deal of upper body strength. Typically, however the water planing devices fail to provide as much control as is available with water skis, requiring considerable skill to negotiate turns while remaining erect.
Several devices have been disclosed which are hybrids between the two aforementioned categories including the aquaplane of U.S. Pat. No. 2,841,805 issued to Roudebush and the U-shaped water ski described in U.S. Pat. No. 3,585,664 of Thompson. These devices primarily take parallel skis and join them by a rigid or semirigid crossbar at their front, thereby maintaining the skis in a permanent parallel relationship. Similar to water skis, these hybrid devices require a relatively high minimum speed to prevent the rider from sinking, further requiring a substantial amount of resistance to be overcome, thus considerable leg strength and balance, in order to initiate planing. Further, because of the fixed location of the tow rope attachment at the front of the device, the only possible means to adjust for different riders is variation of the length of the rope extension from the front of the device to the handles onto which the rider holds. No adjustment is provided for either the rider's weight or skill level, or for allowing the device to plane at different speeds.
It would be desirable to provide a water ski board for towing behind a boat or the like which may be used by beginners or accomplished skiers, by providing the stability needed by beginners as well as adjustability for speed and skill level for increasing the challenge and controllability for advanced skiers. It is to such a device that the present invention is directed.


1. Field of the Invention
The present invention relates to a clutch assembly, and more particularly to a frictional clutch assembly that can transmit power in a unidirectional manner.
2. Description of Related Art
With reference to FIG. 6, a conventional unidirectional transmitting assembly (10) in accordance with the prior art comprises a driving axle (11), a transmitting sleeve (13), multiple rollers (12) and an output axle (14). The transmitting sleeve (13) is received in the driving axle (11) and has multiple cutouts (15) defined in the outer surface of the sleeve (13). Each cutout (15) has a wide segment and a narrow segment and receives one of the rollers (12). The output axle (14) is mounted in and engages with the transmitting sleeve (13) to rotate with the transmitting sleeve (13).
When the driving axle (11) rotates along a direction corresponding to the narrow segments of the cutouts (15), clockwise as shown by the black arrow, the rollers (12) will be pushed to the narrow segments of the cutouts (15) by means of the friction between the driving axle (11) and the rollers (12). Consequently, the rollers (12) will be securely engaged between the driving axle (11) and the transmitting sleeve (13), such that the transmitting sleeve (13) will rotate with the driving axle (11) and the output axle (14) will be driven to rotate.
When the driving axle (11) rotates in an opposite direction that corresponds to the wide segments of the cutouts (15), counterclockwise as shown by the white arrow, the rollers (12) will move to the wide segments of the cutouts (15). Then, the rollers (12) will freely rotate in the cutouts (15), and the transmitting sleeve (13) and the output axle (14) will not rotate and will keep stationary. Accordingly, the input power will be transmitted in a unidirectional manner.
However, the conventional unidirectional transmitting assembly (10) does not have a function of a clutch, so it is necessary to add an additional clutch device for a machine with a conventional unidirectional transmitting assembly and this renders the machine expensive.
To overcome the shortcoming, the present invention tends to provide a frictional clutch assembly to mitigate or obviate the aforementioned problems.


Aqueous is a clear, colorless fluid that fills the anterior and posterior chambers of the eye. The aqueous is formed by the ciliary body in the eye and is a carrier of nutrients for the lens. In addition, the aqueous provides a continuous stream into which surrounding tissues can discharge the waste products of metabolism.
The aqueous produced in the ciliary processes circulates from the posterior chamber to the anterior chamber of the eye through the pupil and is absorbed through the trabecular meshwork, a plurality of criss-crossing collagen cords covered by endothelium. Once through the trabecular meshwork, the aqueous passes through Schlemm's canal and into venous circulation. The rate of aqueous outflow through the trabecular meshwork in a normal eye is typically 2.1 .mu.L/min. Intraocular pressure in the eye is maintained by the formation and drainage of the aqueous. All the tissues within the corneoscleral coat covering the eyeball are subject to this pressure, which is higher than pressure exerted on tissues at other locations in the body.
Glaucoma is a progressive disease of the eye characterized by a gradual increase of intraocular pressure. This increase in pressure is most commonly caused by stenosis or blockage of the aqueous outflow channel, resulting in excessive buildup of aqueous fluid in the eyeball. Other causes include increase in venous pressure outside the eye which is reflected back through the aqueous drainage channels and increased production of aqueous. In a "normal" eye, intraocular pressure ranges from 4 to 12 mm mercury. In an eye with glaucoma, this pressure can rise to as much as 50 mm mercury. This increase in intraocular pressure produces gradual and permanent loss of vision in the afflicted eye.
Existing corrective methods for the treatment of glaucoma include drugs, surgery, and implants. Miotic drugs lower intraocular pressure by facilitating aqueous outflow. Beta blockers, epinephrine products, and carbonic anhydrase inhibitors which inhibit production of the aqueous, are also commonly used in pharmacological glaucoma treatment. Steroids have been used in long-term glaucoma treatment as well. However, pharmacological treatment is prohibitively expensive to a large majority of glaucoma patients. In addition, many people afflicted with the disease live in remote or undeveloped areas where the drugs are not readily accessible. The drugs used in the treatment, in particular the steroids, often have undesirable side effects and many of the long-term effects resulting from prolonged use are not yet known.
Surgical procedures have been developed in an effort to treat victims of glaucoma. An iridectomy, removal of a portion of the iris, is often used in angle-closure glaucoma wherein there is an occlusion of the trabecular meshwork by iris contact. Removal of a piece of the iris then gives the aqueous free passage from the posterior to the anterior chambers in the eye. A trabeculotomy, opening the inner wall of Schlemm's canal, is often performed in cases of open-angle glaucoma so as to increase the outflow of the aqueous, thereby decreasing intraocular pressure. While often successful, these surgical techniques possess inherent risks associated with invasive surgery on an already afflicted eye. Furthermore, the tissue of the eye can grow back to the preoperative condition, thereby necessitating the need for further treatment.
Ocular implants are often used in long-term glaucoma treatment without the disadvantages of drugs and invasive surgery. One such implant is disclosed in U.S. Pat. No. 4,457,757 entitled "Device for Draining Aqueous Humor" and commercially available as the Molteno.TM. Seton Implant. The implant comprises a drainage tube connected to one or more ridged plate reservoirs. The reservoir plates are designed to conform to the curvature of the eye. A reservoir plate is placed under Tenon's capsule and sutured to the sclera. The drainage tube is implanted into the anterior chamber through a scleral flap. A second plate can be implanted under the superior rectus muscle and sutured to the sclera. At this point, the body will form a tissue around these plates. Increased pressure causes the tissues above the plates to lift and form a bleb into which aqueous fluid from the anterior chamber drains via the drainage tube. Once inside the bleb, the aqueous seeps into intercellular spaces and is removed by surrounding capillaries or lymphatics. This type of implant is disadvantageous as the plates are formed of a rigid plastic which makes insertion beneath the eye tissue difficult and time-consuming. Furthermore, the rigid material poses a risk of irritation and/or damage to adjacent vasculature and tissue.
U.K. Patent Application 2,160,778 entitled "Aqueous humor drainage device" discloses a similar type of implant device comprising a drainage tube and a drainage body. The tube is fixed to and opens directly onto a surface of the body. The device is sutured to the sclera of the eye and the tube positioned within the anterior chamber so as to provide outflow for the aqueous contained therein. The device further includes a pressure gradient limiting valve formed as a slit in the tube, however, this type of valve does not allow patent, i.e., open or two-way, flow through the drainage tube, thereby preventing retrograde aqueous flow into the anterior chamber.
Glaucoma implants require formation of scar tissue and a drainage bleb around the implant to control the outflow of the aqueous. In some cases, due to extreme intraocular pressure, the drainage bleb that forms is excessive in size, and may cause impaired vision due to unexpected complications. If the drainage bleb is too large, the eye may protrude from its orbit, or eye socket, and cause distortions in the patient's vision. This is especially problematic in patients with small orbits. In addition, the drainage bleb may press upon the internal tissues of the eye which will result in impaired vision due to increased retinal pressure. In these cases, the potential side effects may negate the advantages of the surgery.


The present invention, in some embodiments thereof, relates to methods and compositions for treating angiogenesis-related diseases such as cancer, and methods of selection thereof.
The neuropilin-1 (np1) and the neuropilin-2 (np2) receptors were originally characterized as functional receptors for axon guidance factors belonging to the class-3 semaphorin (sema3) family. It was subsequently realized that the neuropilins are expressed by endothelial cells and by many types of cancer cells. It was also found that the neuropilins function in addition as receptors for several angiogenic factors belonging to the VEGF family and as receptors for the angiogenesis/metastasis inducing growth factor hepatocyte growth factor/scatter factor (HGF/SF), and that they function as potent enhancers of their pro-angiogenic activity.
Most of the sema3s, with the exception of sema3E which binds to PlexD1, bind to one of the two neuropilin receptors or to both. Neuropilins form spontaneous complexes with several members of the plexin receptor family. In these complexes the sema3s bind to neuropilins while the plexins function as the signal transducing elements. The four type-A plexins (plexins-A1 to plexin-A4) as well as plexin-D1 form complexes with neuropilins and participate in neuropilin mediated signal transduction.
Semaphorins sema3B and sema3F were also characterized as tumor suppressors whose loss contributes to the development of lung cancer [Tomizawa, Y., 2001, Proc. Natl. Acad. Sci. U.S.A 98:13954-13959; Xiang, R., 2002. Cancer Res. 62:2637-2643].
The identification of neuropilins in endothelial cells suggested that class-3 semaphorins may be able to regulate angiogenesis. Indeed, the class-3 semaphorin sema3F, a np2 agonist, functions as a repellant of endothelial cells, induces apoptosis of endothelial cells upon prolonged stimulation [Bielenberg, D. R., et al., 2004, J. Clin. Invest 114:1260-1271; Guttmann-Raviv, N., et al., 2007, J. Biol. Chem. 282:26294-26305] and inhibits angiogenesis and tumor progression in-vivo [Bielenberg, D. R., et al., 2004, J. Clin. Invest 114:1260-1271; Kessler, O., et al 2004. Cancer Res. 64:1008-1015. The np1 agonist sema3A was also shown to inhibit in-vitro and in-vivo angiogenesis [Miao, H. Q., 1999. J. Cell Biol. 146:233-242. Bates, D., 2003, Dev. Biol. 255:77-98; Acevedo, L. M., 2008. Blood. 111:2674-2680]. Sema3E was also characterized as a repulsive agent that inhibits the invasion of PlexD1 expressing blood vessels into somites during embryonic development [Gu C. et al., 2005, Science 307:265-268].
In contrast, existing data suggests that sema3C functions as a pro-tumorigenic and pro-angiogenic agent [Herman J G, et al, Int. J. Oncol. 2007; 30:1231-1238; Banu N, FASEB J. 2006; 20:2150-2152].
The fact that neuropilins and plexins such as PlexD1 are also expressed by many types of tumor cells indicates that semaphorins may also affect the behavior of tumor cells directly. Indeed, sema3s such as sema3F and sema3B have been observed to inhibit the adhesion, migration or the proliferation of tumor cells expressing appropriate semaphorin receptors [Tomizawa, Y., 2001, Proc. Natl. Acad. Sci. U.S. A 98:13954-13959; Xiang, R., 2002. Cancer Res. 62:2637-2643; Bielenberg, D. R., et al., 2004, J. Clin. Invest 114:1260-1271; Nasarre, 2006, Neoplasia. 7:180-189]. In contrast, however, the cleavage product of Sema3E, was shown to be an inducer of tumor invasiveness and tumor metastasis [Christensen, C, 2005, Cancer Res. 65, 6167-6177].


1. Field of the Invention
The present invention relates to a semiconductor memory capable of executing a read test for stored contents comparatively easily, and more particularly to a nonvolatile semiconductor memory such as an electrically writable/erasable flash memory.
2. Description of the Background Art
In general, the production cost of a memory implies the total of the cost required for a wafer process, an assembly and a test. The cost of the test depends on how many chips can be tested per unit time by means of one tester. In order to reduce the test cost to produce a more inexpensive memory, accordingly, it is required that the prolongation of a test time caused by an increase in a storage capacity of the memory should be minimized even if the storage capacity of the memory is increased twofold to fourfold with an increase in the capacity.
In order to shorten a test time of the memory, the following should be implemented:
(1) a reduction in an operation time required for write, read or the like;
(2) development of a test pattern having a higher defect detecting capability; and
(3) development of a test mode capable of carrying out write/read at a higher speed.
Referring to (1), an increase in a speed of production has been required. Therefore, the test time tends to be shortened comparatively easily without a special contrivance through an enhancement in transistor performance by microfabrication and a reduction in a load capacity.
Referring to (2), there are various test patterns having high defect detecting capabilities. Typically, a checker board pattern can be taken as an example.
FIG. 95 is a diagram illustrating an example of the checker board pattern. FIG. 95 shows a checker board pattern having one bit/cell (binary-value).
As shown in FIG. 95, a checker board pattern CHK2 is a test pattern having a repetitive cycle of 2 bits in which adjacent bits always have a relationship of xe2x80x9c0xe2x80x9d and xe2x80x9c1xe2x80x9d. The checker board pattern CHK2 can detect open (disconnection) and a short circuit of a word line, open and a short circuit of a bit line, and a defective short circuit of floating gates in a nonvolatile semiconductor memory represented by a flash memory.
FIG. 96 is a diagram illustrating a checker board pattern CHK4 having 2 bits/cell (quaternary-value). As shown in FIG. 96, 2-bit patterns CHK4-A to CHK4-D are repeated every 4-bit repetitive cycle in order to correspond to the quaternary-value (2 bits/cell) to be multiple-valued storage through application of the checker board pattern CHK2 shown in FIG. 95.
FIG. 97 is a diagram illustrating a checker board pattern CHK8 having 3 bits/cell (octal-value). As shown in FIG. 97, a 3-bit pattern is repeated every 8-bit repetitive cycle in order to correspond to the octal-value (3 bits/cell) to be multiple-valued storage.
In the checker board pattern CHK4 and the checker board pattern CHK8, it is possible to detect a defective mode of the checker board pattern CHK2, and furthermore, to detect that all multiple-valued data can be written and read or not in the same word line and the same bit line.
Referring to (3), there have been various methods. In general, if a test mode is incorporated into a chip, a chip area tends to be increased due to an incorporated circuit. Consequently, a cost required for a wafer process is increased. Accordingly, in the case in which the test mode is to be incorporated into the chip, it is necessary to note that the total production cost should be minimized.
Next, the trend of a product of a flash memory and that of development will be described.
As an alternative to an EPROM (electrically writable nonvolatile semiconductor memory), a flash memory has spread for code storage. In recent years, a flash memory for mass data storage has spread more increasingly than the flash memory for code storage. In the case in which the flash memory for data storage carries out writing and reading randomly, it operates at a lower speed than that of the flash memory for code storage. However, in the case in which the flash memory for data storage carries out writing and reading sequentially, it can operate at a higher speed than that of the flash memory for code storage. The flash memory for data storage has had a larger capacity to exceed a DRAM through microfabrication of a processing pattern and a multiple-valued technique for storing multibit data in one memory cell.
Next, a test time for the flash memory will be described.
The flash memory for code storage has such a structure that a reading operation can be carried out at a much higher speed than a writing operation. Therefore, a time required for a read test can be almost ignored with respect to the whole test time. However, the flash memory for data storage carries out the writing operation at a higher speed and has a larger capacity than the flash memory for code storage. Therefore, the time required for the read test cannot be disregarded with respect to the whole test time.
For example, a 256 Mbit flash memory has a 16 Ksector structure in which a 2 Kbyte write/read unit (hereinafter referred to as a xe2x80x9csectorxe2x80x9d) is present for 16K. Approximately 50 xcexcs is required for a reading head every sector (hereinafter referred to as a xe2x80x9c1st accessxe2x80x9d) and 50 ns is required for subsequent data transfer every byte.
Accordingly, approximately 2.5 s ((50 xcexcs+50 nsxc3x972 Kbyte)xc2x716 Ksector) is required for carrying out a read test in the whole area of the 256 Mbit flash memory.
In a probing check stage of a wafer state, furthermore, it is hard to carry out a read test with a 2nd access 50 ns of a product specification due to a resistance and a capacitance of a probe needle and a resistance and a capacitance of a probe card, and a test time is further increased.
In general, the flash memory has an automatic writing/erasing function. The automatic writing function implies a function of repeating a write pulse applying operation and an operation (hereinafter referred to as a xe2x80x9cverify operationxe2x80x9d) for deciding whether desirable data are written (or erased) to (or from) an object memory cell for writing in accordance with a logic circuit (hereinafter referred to as a xe2x80x9ccontrol circuitxe2x80x9d) provided in an EEPROM, ending the repetition of the write pulse applying operation and the verify operation when it is decided that all the object memory cells store the desirable data and outputting a signal for giving, to the outside of the EEPROM, a notice that the writing operation (or the erasing operation) has been completed.
In order to decide whether xe2x80x9cthe contents stored in all the object memory cells are the desirable dataxe2x80x9d, an all latch deciding circuit (hereinafter referred to as an xe2x80x9cALL deciding circuitxe2x80x9d) is provided. The ALL deciding circuit serves to decide that all sense latches in a sense latch group provided for storing the result of read of the memory cell are xe2x80x9c1xe2x80x9d or xe2x80x9c0xe2x80x9d.
FIG. 98 is a block diagram schematically showing a conventional ALL deciding circuit and a periphery thereof. In this specification, it is assumed that the case in which xe2x80x9c1xe2x80x9d is written to the memory cell is set to xe2x80x9cwritexe2x80x9d and the case in which xe2x80x9c0xe2x80x9d is written to the memory cell is set to xe2x80x9cerasexe2x80x9d. Referring to FIG. 98, description will be given in which a left memory cell group 31 is referred to as an L mat 31 and a right memory cell group 32 is referred to as an R mat 32.
As shown in FIG. 98, a sense latch group 33 is provided between the L mat 31 and the R mat 32. The sense latch group 33 transmits and receives data in a sector unit to and from the L mat 31 or the R mat 32. The latch data of the sense latch group 33 are output to an ALL deciding circuit 34.
The ALL deciding circuit 34 receives control signals LorR, 0or1 and ENABLE from an external control CPU 35 and outputs a decision result ALL34 to the control CPU 35. xe2x80x9c0xe2x80x9d/xe2x80x9c1xe2x80x9d of the LorR designates reading from the L mat 31/R mat 32, xe2x80x9c0xe2x80x9d/xe2x80x9c1xe2x80x9d of the 0or1 designates write verify/erase verify, and xe2x80x9c0xe2x80x9d/xe2x80x9c1xe2x80x9d of the ENABLE designates inactivity/activity of the ALL deciding circuit 34.
FIGS. 99 to 102 are diagrams illustrating an operation principle of a conventional ALL deciding circuit, in which the ALL deciding circuit has a function of deciding that all sense latches are xe2x80x9c0xe2x80x9d.
As shown in FIGS. 99 to 102, the sense latch group 33 is provided between the L mat 31 and the R mat 32, and nodes N11 and N12 of each latch L33 of the sense latch group 33 are connected to the L mat 31 and the R mat 32 in one memory cell unit, respectively. The node N11 and the node N12 in the latch L33 are constituted to have a logical inverting relationship. A data latch group 36 is provided on the opposite side of the sense latch group 33 with the L mat 31 interposed therebetween, and a data latch group 37 is provided on the opposite side of the sense latch group 33 with the R mat 32 interposed therebetween.
First of all, the ENABLE is set to xe2x80x9c1xe2x80x9d for initialization and the ALL deciding circuit 34 is thus brought into an active state.
As shown in FIG. 99, when the write verify for the L mat 31 is to be carried out, LorR=xe2x80x9c0xe2x80x9d (L) and 0or1=xe2x80x9c1xe2x80x9d are set so that data read from the L mat 31 are latched onto each latch L33 of the sense latch group 33. If xe2x80x9c1xe2x80x9d is normally written to the L mat 31, the nodes N11 of all the latches L33 of the sense latch group 33 are set to xe2x80x9c1xe2x80x9d and the nodes N12 are set to xe2x80x9c0xe2x80x9d.
Accordingly, it is possible to execute the L mat write verify by deciding the state of the nodes N12 of all the latches L33 in the sense latch group 33 (whether all of them are xe2x80x9c0xe2x80x9d) through the ALL deciding circuit (R side sense latch decision).
As shown in FIG. 100, similarly, when the erase verify for the L mat 31 is to be carried out, LorR=xe2x80x9c0xe2x80x9d and 0or1=xe2x80x9c0xe2x80x9d are set. If xe2x80x9c0xe2x80x9d is normally written to the L mat 31, the nodes N11 of all the latches L33 in the sense latch group 33 are set to xe2x80x9c0xe2x80x9d and the nodes N12 are set to xe2x80x9c1xe2x80x9d.
Accordingly, it is possible to execute the L mat erase verify by deciding the state of the nodes N11 of all the latches L33 in the sense latch group 33 through the ALL deciding circuit (L side sense latch decision).
As shown in FIG. 101, when the write verify for the R mat 32 is to be carried out, LorR=xe2x80x9c1xe2x80x9d (R) and 0or1=xe2x80x9c1xe2x80x9d are set so that data read from the R mat 32 are latched onto each latch L33 of the sense latch group 33. If xe2x80x9c1xe2x80x9d is normally written to the R mat 32, the nodes N12 of all the latches L33 of the sense latch group 33 are set to xe2x80x9c1xe2x80x9d and the nodes N11 are set to xe2x80x9c0xe2x80x9d.
Accordingly, it is possible to execute the R mat write verify by deciding the state of the nodes N11 of all the latches L33 in the sense latch group 33 through the ALL deciding circuit (L side sense latch decision).
As shown in FIG. 102, similarly, when the erase verify for the R mat 32 is to be carried out, LorR=xe2x80x9c1xe2x80x9d and 0or1=xe2x80x9c0xe2x80x9d are set. If xe2x80x9c0xe2x80x9d is normally written to the R mat 32, the nodes N12 of all the latches 33 in the sense latch group 33 are set to xe2x80x9c0xe2x80x9d and the nodes N11 are set to xe2x80x9c1xe2x80x9d.
Accordingly, it is possible to execute the R mat erase verify by deciding the state of the nodes N12 of all the latches L33 in the sense latch group 33 through the ALL deciding circuit (R side sense latch decision).
The ALL deciding circuit carries out the R or L side sense latch decision based on a logical expression of {(LorR) X OR (0or1)}. It is sufficient that the R side sense latch decision is carried out with xe2x80x9c1xe2x80x9d and the L side sense latch decision is carried out with xe2x80x9c0xe2x80x9d.
Based on the result of the decision of the ALL deciding circuit for deciding whether all the memory cells in the sector are xe2x80x9c0xe2x80x9d, thus, it is possible to execute the write verify and erase verify operations without outputting read data for each bit from data input/output pins.
In this case, a time of approximately 150 xcexcs (50 xcexcs+50 nsxc2x72 Kbyte) required for normal reading per sector can be shortened to 50 xcexcs+xcex1 (xcex1 less than 1 xcexcs). Therefore, the read test time can be shortened to approximately one-third.
In this case, however, it is premised that all the write data in the sectors are identical. For this reason, there has been a problem in that the write data cannot be used for test reading through the checker board pattern CHK2, CHK4, CHK8 or the like which has a high defect detecting capability.
A first aspect of the present invention is directed to a semiconductor memory comprising a plurality of memory cells, each of which can store N-valued (Nxe2x89xa72) information, a data reading device for reading a predetermined number of read data from a predetermined number of memory cells out of said plurality of memory cells during a reading operation for a test, and a deciding device for classifying the predetermined number of read data into K (Kxe2x89xa72) groups and outputting a decision result based on whether all the read data in the respective K groups are identical during the reading operation for a test.
A second aspect of the present invention is directed to the semiconductor memory according to the first aspect of the present invention, wherein the K includes N, the memory cells include memory cells arranged in a matrix defined by first and second directions, the predetermined number of memory cells include memory cells provided in the same position in the second direction and provided in series in the first direction, and the deciding device classifies the predetermined number of read data such that the predetermined number of memory cells are classified into the same groups at N intervals in the second direction.
A third aspect of the present invention is directed to the semiconductor memory according to the second aspect of the present invention, wherein the N-value includes a 2m-value (mxe2x89xa71).
A fourth aspect of the present invention is directed to the semiconductor memory according to any of the first to third aspects of the present invention, the deciding device includes a sense storing device for sensing and storing the predetermined number of read data, and a decision result output device for deciding whether all the read data in the respective K groups are identical based on stored contents of the sense storing device and for outputting a result of the decision.
A fifth aspect of the present invention is directed to the semiconductor memory according to any of the first to fourth aspects of the present invention, wherein the N-value includes a multiple-value to be ternary or more, the reading operation for a test includes first to Lth (Lxe2x89xa72) partial reading operations for a test which have different reading conditions and the read data include first to Lth 1-bit read data, the data reading device reads the predetermined number of first to Lth 1-bit read data during execution of the first to Lth partial reading operations for a test, the result of decision includes first to Lth partial decision results, and the deciding device outputs an ith (i=1 to L) partial decision result based on whether all ith 1-bit read data in the respective K groups are identical during an ith partial reading operation for a test.
A sixth aspect of the present invention is directed to a semiconductor memory comprising a plurality of memory cells, each of which can store N-valued (Nxe2x89xa72) information, a data reading device for reading a predetermined number of read data from a predetermined number of memory cells out of said plurality of memory cells during a reading operation for a test, an expectation storing device for storing a predetermined number of expectation data, and a deciding device for outputting a result of decision based on a result of comparison of the predetermined number of read data with the predetermined number of expectation data during the reading operation for a test.
A seventh aspect of the present invention is directed to the semiconductor memory according to the sixth aspect of the present invention, the deciding device includes a sense storing device for sensing and storing the predetermined number of read data, and a decision result output device for outputting the result of decision based on a result of comparison of stored contents of the sense storing device with stored contents of the expectation storing device.
An eighth aspect of the present invention is directed to the semiconductor memory according to the seventh aspect of the present invention, wherein the N-value includes a multiple-value to be ternary or more, the reading operation for a test includes first to Lth (Lxe2x89xa72) partial reading operations for a test which have different reading conditions, the read data include first to Lth 1-bit read data and the expectation data include first to Lth 1-bit expectation data, the data reading device reads the predetermined number of first to Lth 1-bit read data every execution of the first to Lth partial reading operations for a test respectively, the result of decision includes first to Lth partial decision results, the deciding device outputs an ith (i=1 to L) partial decision result based on a result of comparison of the predetermined number of ith 1-bit read data with the predetermined number of ith 1-bit expectation data during the ith partial reading operation for a test, and the predetermined number of second to Lth 1-bit expectation data are obtained by changing the predetermined number of first to (Lxe2x88x921)th 1-bit expectation data based on the stored contents of the expectation storing device and the sense storing device, respectively.
A ninth aspect of the present invention is directed to the semiconductor memory according to any of the sixth to eighth aspects of the present invention, wherein the expectation storing device includes a data storing device for temporarily storing data when transmitting and receiving data between the memory cells and an outside.
As described above, according to the first aspect of the present invention, a comparatively complicated test pattern having the same value set to the K groups is written to the memory cells and the reading operation for a test is then executed to obtain the result of decision. Consequently, the read test for the memory cells can be carried out at a high speed.
Moreover, it is sufficient that the deciding device has the function of deciding whether all the read data in the respective K groups are identical. Therefore, the circuit area of the semiconductor memory is rarely increased due to the provision of the deciding device therein.
According to the second aspect of the present invention, a predetermined number of memory cells are classified into the same group at the N intervals in the second direction. Therefore, it is possible to carry out the read test in which the checker board pattern having the N-value is set to be a test pattern.
According to the third aspect of the present invention, it is possible to carry out a read test in which a checker board pattern having a repetitive cycle of m bits is set to be the test pattern.
According to the fourth aspect of the present invention, a predetermined number of read data are sensed and stored in the sense storing device. Consequently, it is possible to obtain a result of decision with high precision.
According to the fifth aspect of the present invention, the result of decision comprising the first to Lth partial decision results is obtained. Consequently, it is possible to carry out the read test in a multiple-valued storage state for the memory cell without hindrance.
According to the sixth aspect of the present invention, a predetermined number of expectation data are stored from the outside into the expectation storing device. Consequently, it is possible to carry out a read test based on an optional test pattern. Moreover, in the case in which the predetermined number of expectation data are utilized in common between the predetermined number of data read plural times, it is preferable that the predetermined number of expectation data should be stored in the expectation storing device at a first time. Therefore, a time required for storing the predetermined number of expectation data in the expectation storing device can be omitted during the reading operation of the predetermined number of read data at and after a second time. Correspondingly, the read test can be carried out at a high speed.
Moreover, it is preferable that the deciding device should have the function of outputting the result of decision based on the result of comparison of the predetermined number of read data with the predetermined number of expectation data. Therefore, the circuit area of the semiconductor memory is rarely increased due to the deciding device constituted therein.
According to the seventh aspect of the present invention, the predetermined number of read data are sensed and stored in the sense storing device. Consequently, it is possible to obtain a result of decision with high precision.
According to the eighth aspect of the present invention, the result of decision comprising the first to Lth partial decision results is obtained. Consequently, it is possible to carry out the read test in a multiple-valued storage state for the memory cell without hindrance. In this case, the predetermined number of second to Lth 1-bit expectation data are obtained by changing the predetermined number of first to (Lxe2x88x921)th 1-bit expectation data based on the contents stored in the expectation storing device and the sense storing device, respectively. Therefore, it is sufficient that only the predetermined number of first 1-bit expectation data should be stored in the expectation storing device.
According to the ninth aspect of the present invention, the expectation storing device does not need to be added specially for expectation data storage.
An object of the present invention is to provide a semiconductor memory capable of executing a read test at a high speed based on a comparatively complicated test pattern without increasing a circuit area. These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.


1. Field of the Invention
This invention relates to an attenuator circuit for electrically varying the amount of attenuation of an input signal.
2. Related Art
In general, an attenuator circuit used for a transmitter on the side of the head end (or antenna site) in a two-way community antenna television (CATV) or for a small signal transmitting module such as a communication unit is a .pi. type resistance attenuator which, as shown in FIG. 4(a), is made up of resistors R1, R2 and R3, or a circuit as shown in FIG. 4(b) in which a signal detector circuit 3 detects the output signal of an amplifier 2, and an automatic gain control (AGC) amplifier 1 controls the output gain according to the detection output of the signal detector circuit 3.
In the case of the circuit shown in FIG. 4(a), the amount of attenuation is fixed. Hence, the circuit suffers from a problem that the amount of attenuation cannot be changed as desired.
In the case of the circuit shown in FIG. 4(b), the amount of attenuation can be changed. However, the circuit is still disadvantageous in that it is high in manufacturing cost because it needs the signal detector circuit made up of a number of circuit elements.
Accordingly, an object of this invention is to eliminate the above-described difficulties accompanying a conventional attenuator circuit. More specifically, an object of the invention is to provide an attenuator circuit which is able to vary the amount of attenuation, and which is low in manufacturing cost.
FIG. 7 shows another example of the attenuator circuit of this type, which is made up of a plurality of .pi. type resistance circuits each comprising resistors R1, R2 and R3, and transistor-transistor logic (TTL) drive circuits for controlling the resistance circuits, respectively. For instance, when it is required to attenuate a signal as much as 30 dB in steps of 1 dB, the attenuator circuit should be so designed that the attenuation is made in five steps, 1 dB, 2 dB, 4 dB, 8 dB and 15 dB, as shown in FIG. 7. The attenuator circuit is high in manufacturing cost.


The following discussion, of the background to the invention is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge (in any country) as at the priority date of any of the claims.
The banana plant is a large perennial herb with leaf-petiole sheaths that form generally cylindrical, trunk-like pseudostems. Each pseudostem grows from a bud on the true stem (corm), which is an underground rhizome, and can grow to heights normally in the range of 3 to 8 meters over a 9 to 18 month period. When mature, the pseudostem will comprise a soft but dense centre (a ‘core’) surrounded by an outer layer (a ‘sheath’) that is tougher but is less dense, the outer layer typically being formed by the overlapping leaf-petiole sheaths.
Commercially planted banana plants typically only have 1 to 2 year life-spans, as banana plants only flower (and produce bananas) once, following which the leaves, leaf stalks and pseudostem start to die. This usually requires their removal in some manner, such as by simply being cut down, allowing regrowth of a new pseudostem from the rhizome and the commencement of a new reproductive phase.
With annual production in 2002 of about 68 million tonnes of bananas (more than two thirds coming from within India, Brazil, China, Ecuador and the Philippines), it has been recognised that banana pseudostems represent a potentially valuable renewable resource, one which has been traditionally under-utilised and historically economically ignored by banana growers. With this in mind, there have been numerous attempts to use the pseudostems for the production of paper, due to the beneficial properties and qualities of the fibre in the pseudostems.
However, in a paper titled “Banana Stem Fibre for Papermaking” by S. K. Singhai, J. K. Garg and B. Biswas for the Indian Pulp and Paper Journal, August-September 1975, 30(2), pp 13 to 15, the situation at that time was summarised as “The pulping and papermaking qualities of banana (M. sapientum and M. paradisica) stem fibre have been examined. From the available information given in this paper, it is to be considered that neither technically nor economically the use of banana stem fibre is a feasible proposition.” Thus, at least in the mid 70's, no sensible approach had yet been developed to the use of these materials for paper production.
Since then, it has continued to be recognised that banana pseudostem fibres should have suitable properties for paper production. In a paper titled “Plantain (M. Paradisiaca L) Pseudostem; A Fibre Source For Tropical Countries” by Nicholas A Darkwa of the Forestry Research Institute of Ghana, published in Book 2, TAPPI Proceedings, 1998 for the 1998 Pulping Conference in Montreal Quebec, it was concluded that “ . . . tropical countries that are deficient in long-fibred material for their pulp and paper production can utilise the pseudostems of plantain and banana for such purposes.”
Indeed, several attempts have been made to use banana plant refuse (predominantly pseudostems, but including leaves, leaf stalks, immature inflorescence and unused bananas) in existing or modified paper pulping processes—see U.S. Pat. No. 5,958,182 for a short summary of some such processes.
However, such refuse commonly has an extremely high water and natural latex content, and includes numerous resinous and gummy substances that are difficult to handle and process. In order to produce workable fibres having desirable characteristics for paper-making, it has proven necessary to extract these fluids and, in particular, wash out the latex and other natural resinous substances. This has proven to be technically difficult, and has generally made the pulping of banana refuse for the production of paper uneconomic, particularly for bulk paper supplies and for anything other than boutique or artistic papers. It has also generally presented the manufacturers with significant chemical waste disposal issues.
In Australia, while it has been reported that a good quality paper can be made in low volume by combining banana fibre with that of the betel nut husk (Areca catechu L.), Australian investigators have still concluded that the yield of banana fibre is too low for extraction to be economical. It has been reported that only 1 to 4 oz (28-113 g) of suitable fibre can be obtained from 40 to 80 lbs (18-36 kg) of green pseudostems from the pulping process. Thus, 132 tonnes of green pseudostems would yield only 1 tonne of paper. The conclusion was that the pseudostem would have much greater value as organic matter chopped and left in the field to fertilise subsequent crops.
The present invention seeks to provide a method that makes possible the use of banana plants in the family Musaceae for the production of sheets useful in the production of raw paper for subsequent conversion to paper products, ideally in a manner that is both technically simple and reasonably economic, so as to permit relatively high volume paper production therefrom.


Nitric oxide (referred to herein as “NO”) has many uses, including as a medicinal agent. For example, NO has been shown to inhibit smooth muscle proliferation, thrombus formation, platelet aggregation, and smooth muscle contraction. NO can also be used as a bacteriocidal or bacteriostatic agent to sterilize the surfaces of, for example, medical devices. However, the half-life for NO release of most of the known compounds which release NO is less than twelve hours. Thus, most known NO-releasing compounds are too unstable to be useful commercially. The full commercial potential of NO is unlikely to be realized until more stable NO-releasing compounds are developed.


The present invention relates to a method for making a powder of aluminum nitride.
For manufacturing an aluminum nitride powder, there are many methods well known to those skilled in the art. For example, Japanese Laid-open Patent Publication No. 53-68700, published in 1978, discloses the manufacture by causing an aluminum compound to react with ammonia or the like to produce an aluminum-nitrogen compound which is in turn heat-treated. Japanese Laid-open Patent Publication No. 54-126697, published in 1979, discloses the addition of an aluminum nitride powder to a powdery mixture of alumina and carbon and the subsequent heat-treatment of the resultant mixture in an N.sub.2 atmosphere. Japanese Laid-open Patent Publication No. 57-22106, published in 1982, discloses heating an aluminum foil and a carbon paper to 600.degree. C. or higher in a non-oxidizing atmosphere, contacting them with an oxygen containing gas, and finally treating them in an atmosphere containing a mixture of oxygen and nitrogen.
However, since all of the prior art methods are of a batch production system utilizing a gas-solid reaction, not only is the productivity low, but also the method is complicated. In the case of the method wherein the aluminum nitride powder is mixed, not only is the running cost high, but also since the powder is used as one of the raw material, the raw material tends to scatter, posing a problem in that the working environment is contaminated.


There is an acute need for new pesticides. For example, insects and mites are developing resistance to the insecticides and acaricides in current use. At least 400 species of arthropods are resistant to one or more insecticides. The development of resistance to some of the older insecticides, such as DDT, the carbamates, and the organophosphates, is well known. But resistance has even developed to some of the newer pyrethroid insecticides and acaricides. Therefore, a need exists for new insecticides and acaricides, and particularly for compounds that have new or atypical modes of action.


Process control refers to the control of the operational parameters of a system by monitoring one or more of its characteristics over time. It is used to insure that the quality and efficiency of the system remain within desired parameters over the course of time. While process control is typically employed in the manufacturing sector for process, repetitive and discrete manufactures, it also has wide application in service industries, such as environmental control.
Process control equipment typically utilizes control/sensing devices that are physically integrated into the systems being controlled. For example, a thermostat is typically used in environmental control to insure that building temperatures remain within specified parameters. Likewise, flow control sensors and automated valves are typically used in process manufacturing to insure proper fluid flow volumes.
Though in early process control systems, control/sensing devices were typically stand-alone units, modern process control systems provide central workstations for monitoring and controlling the control/sensing devices. Particularly robust systems are the I/A Series™ industrial automation systems designed, manufactured and marketed by the assignee hereof, The Foxboro Company, of Foxboro, Mass., USA. In these systems, multiple control/sensing devices are coupled by way of buses to control stations which, in turn, are coupled by way of a local area network (LAN) to one or more operator workstations.
The I/A Series systems are built around the client/server model. Client applications software executing on the workstations exchange information with the control/sensing devices via a server, referred to as the “object manager,” executing in distributed fashion in the control stations. Upon request by a client application, the server creates, locates, accesses and updates data structures (“objects”) storing information on the status of at least selected control/sensing devices. For example, a client application that displays temperatures sensed by a thermocouple requests that the server create an object storing a temperature reading from the thermocouple and that the server notify the client each time the temperature changes.
Although modern process control systems, such as the I/A Series systems, have proven quite successful, to date they have provided only limited remote access capabilities. Thus, while numerous operator workstations may reside within the factory or facility in which the control/sensing devices are disposed, it has traditionally proven difficult to access and control those devices outside those areas.
Remote access and control of processes is desirable for a number of purposes. A plant manager who is “on the road,” for example, may wish to monitor the plant processes while travelling. By way of further example, the manufacturer of process control equipment may require remote access to a plant's control/sensing devices in order to provide technical support.
An object of this invention is to provide improved methods and apparatus for process control.
Another object of the invention is to provide such methods and apparatus as permit monitoring and control of remote processes.
Still another object of the invention is to provide such methods and apparatus as can be readily adapted to existing automated process control systems.
Yet still another object of the invention is to provide such methods and apparatus as can be implemented without undue expense and without undue consumption of resources.