An improved graphical data structure and method for processing geometrical data stored in a two-dimensional area. The invention is especially suited to storing, deleting, and conducting queries of data related to two-dimensional objects, such as the elements of a VLSI chip layout. A two-dimensional area is provided for storing a plurality of two-dimensional objects. The area may be sub-divided into a horizontal plane and a vertical plane, wherein each plane may contain one or more surfaces. Each surface typically contains a plurality of stripes of equal horizontal dimension, and the stripes are each sub-divided into sub-stripes. An object whose minimum bounding box intersects a particular sub-stripe is represented in one of four bucket lists associated with that sub-stripe. In one example of a preferred embodiment, the bucket list is selected depending upon whether the portion of the object that intersects the sub-stripe is the object's lower-left corner, left edge, bottom edge, or another portion of the object. Each bucket list is made up of a bucket list head and a number of buckets. Routines are provided for inserting objects into the graphical data structure, deleting objects from the structure, and conducting regional queries of the structure.

1. Field of Invention
The present invention pertains broadly to a system for recording or storing the positions of a plurality of objects arranged in an essentially two-dimensional array or plat. The invention more especially pertains to an improved system for generating graphical displays of typically rectangular objects arranged on an essentially two-dimensional surface. The invention has particular application to a graphical system for storing, displaying and manipulating the positions of substantially two-dimensional objects such as the elements of integrated circuits, printed circuit boards, and the like.
2. Description of Related Art
One of the first steps in manufacturing a circuit such as an integrated circuit or printed circuit board involves positioning, or "laying out", the various elements of the circuit and their interconnections. Typically, these circuit elements include transistors, resistors, capacitors, wires, and the like.
Various computer-based systems, called "graphical data structures", have been used to lay out these types of circuits. These graphical data structures typically include routines capable of storing the circuit elements in computer memory, adding new elements, deleting or re-arranging existing elements, and conducting regional queries of elements. When the circuit elements have been finally laid out, information regarding their positioning is output from the computer memory and used to create one or more sheets or "tapes," which provide a blueprint-like representation of the circuit. Later, the tapes may be used in the process of etching, depositing, or otherwise constructing the integrated circuit on a silicon substrate, such processes being well known in the art of semiconductor manufacturing.
The function of graphical data structures is not limited to manipulating circuit elements; in fact, graphical data structures are generally useful in manipulating other two-dimensional shapes. The two-dimensional shapes stored in a graphical data structure are called "objects".
Graphical data structures come in a variety of forms. One known graphical data structure is the multi-dimensional binary tree, often called the "k-d tree". With k-d trees, the size of an object is considered to be the size of the smallest rectangle ("bounding rectangle") capable of containing the object. Objects are sorted according to the horizontal and vertical ("x-y") positions of the left, right, top, and bottom sides of their bounding rectangle.
FIG. 1A shows several objects to be stored in a k-d tree and FIG. 1B illustrates the structure of the k-d tree after the objects are stored therein. Generally, objects to be stored in a k-d tree are sorted according to the position of their edges. In successive sorting operations, the edges are sorted in an order such as the following: left edge, bottom edge, right edge, and top edge.
In the example of FIGS. 1A and 1B, seven objects are to be stored in the k-d tree. Sorting the objects of FIG. 1A according to their left edges places objects 51, 52, and 56 to the left of the left edge of object 53, and objects 54, 55, and 57 to the right of the left edge of object 53. Object 53 is chosen as a central reference point, or "node" of the rectangles, since half of the objects' left edges are to the left of the left edge of object 53 and half of the objects' left edges are to the right of the left edge of object 53.
After the objects are divided in this manner, they are sorted according to the position of their bottom edges. For instance, object 51 forms a node since the bottom edge of object 51 is between the bottom edges of objects 52 and 56. Similarly, object 54 forms a node since the bottom edge of object 54 is between the bottom edges of objects 57 and 55. If additional objects were present in the structure, the objects would be sorted by their right, and then their top edges. This process would be repeated until each node contains a single object.
By using this method, time is saved since a particular region can be queried without searching through all data in the k-d tree. In the above example, a query of the left region would yield objects 53, 51, 52, and 56.
Although k-d trees have been useful for some purposes, they suffer from a number of disadvantages. In the above example, the right region would become more densely populated than the left region if several objects having bounding rectangles with left-edge positions to the right of object 53 were inserted. In this condition, the k-d tree is "unbalanced", and queries of the k-d tree are inefficient. As a result, when the right region is queried, the query must search through more than half of all objects in the k-d tree. In the extreme case, when all objects in the left region are deleted, the k-d tree degenerates into a simple linked list (described below), and queries of the right region must search through all objects in the k-d tree.
An unbalanced k-d tree is inefficient since it requires excessive time to conduct queries. One approach that has been used to overcome balancing problems is periodically re-balancing the k-d tree. Re-balancing involves selecting a new node to re-define the left and right regions. Thus, after re-balancing, each region contains about half of the total number of objects, with the node dividing the two regions.
Although some of the problems with k-d trees are reduced by re-balancing, k-d trees are still limited since they require more computer memory than might be desired for some purposes. Some tolerate this limitation, since k-d trees can offer high query speed in some applications.
Another known graphical data structure is the "quad tree". This category includes a group of programs that have certain common characteristics. With quad trees, a horizontal line and a vertical line divide a two-dimensional area into four quadrants. Objects are categorized according to whether they lie entirely within one of the quadrants, intersect the vertical line, or intersect the horizontal line. For greater detail, each quadrant can be divided into sub-quadrants.
Like other graphical data structures of this type, the object of a query is to identify objects lying within a specified query region. One disadvantage of querying using quad trees is that the queries often yield duplicate results. Since it is possible for an object spanning the query region to intersect the horizontal and/or vertical lines, every query must search through all objects intersecting the vertical and/or horizontal lines.
One modification used to overcome this disadvantage has been to abandon the categories based on horizontal and vertical line intersection. Thus, an object is categorized solely upon the quadrant or sub-quadrant that the object lies in. However, if an object spans two or more quadrants, a query including those quadrants would encounter the object two or more times, i.e. once in each quadrant.
One solution to duplicate reporting in quad trees has been to maintain a software flag for each object. After the object has been reported during a query, a flag associated with that object is set. When an object's flag is set during a query, that object cannot be reported for the remainder of the query. As a result, objects are never reported more than once.
Although this solution has been helpful in some applications, it is limited in that it requires additional computer memory to operate. Furthermore, this solution is limited since it slows the query process by requiring additional operations, such as re-setting the flags. Generally, quad trees are not as memory-intensive as k-d trees. Nonetheless, quad trees require more memory than might be desired in some applications.
Another popular graphical data structure is the linked list. A typical linked list involves a list of data records, wherein each record contains an object and a pointer that points to the beginning of the next record. Although linked lists are useful for some purposes, they are not as efficient as k-d trees or quad trees. As a result, linked lists might be unsatisfactory for certain applications, since linked lists require additional time to conduct queries, additions, and deletions.
One common disadvantage of the k-d trees, quad trees, and linked lists is that they tend to be inefficient when the graphical data include objects having diverse ratios of vertical dimension to horizontal dimension ("aspect ratios"). Quad trees, k-d trees, and linked lists may be satisfactory in some applications involving small objects; however, k-d trees, quad trees, and linked lists perform poorly when applied to the graphical handling of objects of various sizes, e.g., small objects, long narrow objects, medium-sized objects, and very large objects. This type of application is representative of a typical VLSI (very large scale integrated) chip layout. Thus, k-d trees, quad trees, and linked lists perform poorly when the graphical data comprises a VLSI chip layout.

Intelligent and compact bucketing method for region queries in two-dimensional space


A rotary electrical machine comprises: a stator core; a rotor core arranged at the inner periphery of this stator core; a bracket connected with one end of the stator core; a first bearing arranged by means of the bracket; a frame and a housing connected with the other end of the stator core; a second bearing arranged by means of the housing; a ventilation fan provided between the rotor core and the first bearing, with vanes provided on the outside in the axial direction; a rotor shaft that is freely rotatably supported by the first bearing and second bearing; an inlet provided in the frame or the housing; and an outlet provided in the frame or the housing.

1. Field of the Invention
The present invention relates to a rotary electrical machine.
2. Description of the Related Art
In a typical rail vehicle, a rotary electrical machine is mounted on a chassis suspended below the vehicle body and the vehicle is driven by transmission of the turning effort of this rotary electrical machine to the vehicle wheels through a coupling and gearwheel device.
A totally enclosed rotary electrical machine constituting an example of a prior art rotary electrical machine is described below with reference to the drawings. FIG. 1 is a cross-sectional view of such a prior art totally enclosed rotary electrical machine.
In this specification, the longitudinal direction of the rotor shaft is defined as the axial direction.
The arrows in the Figure indicate the direction of air flow.
In the prior art totally enclosed rotary electrical machine shown in FIG. 1, a stator core 4 is provided that is restrained by a core support 4a and core support 4b, between a frame 1 provided on the side opposite to the drive side and an outer peripheral bracket 2a provided on the drive side. An inner peripheral bracket 2b is provided at the inner periphery of the outer peripheral bracket 2a and a housing 3 is provided at the inner periphery of the frame 1. A rotor shaft 7 is freely rotatably supported by bearings 5, 6 that are respectively mounted on the inner peripheral bracket 2b and housing 3. A rotor core 8 is provided in the central section in the axial direction of this rotor shaft 7. A drive side end 7a of this rotor shaft 7 extends outside the machine. A coupling is mounted on this extension. A first ventilation fan 9a is mounted on the rotor shaft 7 on the inside of the bearing 6 and a second ventilation fan 9b is mounted on the opposite side to the drive side of the rotor shaft 7 and on the inside of the bearing 5. Inlets 1a and outlets 1b are provided on the side faces of the frame 1 on the opposite side to the drive side. Through-flow passages are provided in the inner peripheral bracket 2b, the outer peripheral bracket 2a, stator 4 and frame 1. The inlets of the first ventilation fan 9a on the drive side of the rotary electrical machine form external air inlets.
The bearing of the totally enclosed rotary electrical machine is constituted by forming a minute gap between the side of the fixed member and the side of the rotary member; the interior of the rotary electrical machine is thus cut off from the outside i.e. the electrical machine is totally enclosed. External air flowing in from the inlets due to the rotation of the first and second ventilation fans 9a and 9b flows through a through-flow passage (not shown) in which the inner peripheral bracket 2b, outer peripheral bracket 2a, stator 4 and frame 1 are provided and flows out through outlets (not shown) of the frame 1. Due to this passage of external air therethrough, heat evolved by the stator core 13 and rotor bar 14 that is transmitted to the core 12 (not shown) and the frame 1 from the wall of this ventilation passage is removed by being discharged to the external atmosphere. Also, inflow of external air from the inlets 1a is produced by the rotation of the second ventilation fan 9b, thereby cooling the air in the stator core 13 and rotary electrical machine transmitted to the ventilation fan 9b.
A prior art totally enclosed rotary electrical machine constructed in this way had the advantage that there was no possibility of contamination due to deposition of dust mixed with the external air on internal portions of complex structure, since external air cannot flow into the machine, and furthermore had the advantage that a filter to remove dust was unnecessary, since there was no possibility of dust from the external air being deposited, because the cooling effected by the external air took place by passage of the external air through a ventilation passage having a simple structure.
Such a technique is to be found in Laid-open Patent Publications in Japan such as for example Japanese Laid-open Patent Publication No. 2003-18795.
However, in this prior art rotary electrical machine, the temperature of the bearings and of the grease used to lubricate these becomes high, and this made it necessary to carry out maintenance of the bearings at short intervals.


The invention is a method and apparatus for quantitatively characterizing the pressure-induced nonreciprocity of a fiber-optic coil where the pressure-induced nonreciprocity is a property of a fiber-optic coil which pertains to the degree to which light beams, initially in phase, differ in phase as a result of traversing the fiber-optic coil in reverse directions while the fiber-optic coil is being subjected to a time-varying pressure. The method comprises the steps of applying time-varying pressure to the fiber-optic coil for a predetermined time period, measuring the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period, and obtaining a measure of the nonreciprocity of the fiber-optic coil utilizing the measured phase difference. If the time-varying pressure is specified by a first function of time, the measure of the nonreciprocity is the integral over the predetermined time period of the product of a second function of time and either (1) the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period or (2) the integral over time of the phase difference. The second function is chosen such that the measure of the nonrecipocity has a signal-to-noise ratio of at least one. Preferably, the second function is (1) an approximation of the time derivative of the first function if the product involves the phase difference or (2) an approximation of the first function if the product involves the integral of the phase difference. The invention also includes the apparatus for practicing the method.

This invention relates generally to nonreciprocity of fiber-optic coils used in fiber-optic gyros and more specifically to methods and apparatus for determining pressure-induced nonreciprocity.
It was shown by D. M. Shupe in 1980 (D. M. Shupe, Thermally Induced Nonreciprocity in the Fiber-Optic Interferometer, Applied Optics, Vol. 19, No. 5, 1 Mar. 1980, pp. 654-655) that thermally-induced nonreciprocity in fiber-optic ring interferometers can occur if there are time-dependent temperature gradients along the fiber. If corresponding wavefronts of the counter-rotating beams traverse the same region of the fiber at different times, nonreciprocity arises. Shupe showed that this thermally-induced nonreciprocity results in an angular error .theta..sub.ET for the fiber-optic gyro given by ##EQU1## where where
n.sub.c is the refractive index of the fiber core; PA1 N is the number of turns in the fiber--optic coil; PA1 A is the area of the fiber--optic coil; PA1 L is the length of the fiber; PA1 T(t,l) is the temperature of the fiber element at a distance l from the end of the fiber and t is time; and PA1 .alpha. is the coefficient of linear thermal expansion of the fiber core.
In the case of a multilayer fiber coil wound on a cylindrical form such that the difference between the outside and inside coil diameter is small when compared with its average diameter and assuming that the coil temperature varies linearly from its inner layer to its outer layer, ##EQU2## and .DELTA.T is the change in the temperature difference across the coil from the initialization time 0 of the gyro to some later time t.
Fiber-optic coils are screened prior to assembly into fiber-optic gyros on the basis of measured thermally-induced angular error. The measurement of thermally-induced angular error of a fiber-optic coil is accomplished by applying a temperature ramp to the coil. The temperature ramp process is time-consuming and expensive since stabilization of the temperature depends on rather large coil time constants and reduction of angle random walk noise requires significant integration time. The measurement of thermally-induced angular error typically requires about 24 hours.
There is a need for a screening process which can be accomplished in a time much shorter than 24 hours.

Method and apparatus for determining the pressure-induced nonreciprocity of a fiber-optic coil


A computerized system and method for viewing a set of voxel data on a display device attached to a computer is disclosed. In one embodiment of the invention, the computerized system has a number of different components. A retrieve data set component retrieves the set of voxel data, the set of voxel data having already been acquired in accordance with acquisition parameters of a protocol. A protocol selector component selects the protocol in accordance with the set of voxel data retrieved, the protocol including preset adjustments for the volume-rendering of the data. An image gallery component displays one or more images of the set of voxel data in accordance with the preset adjustments of the protocol. An examination viewer component permits the changing of the preset adjustments of the protocol as to a particular image selected. within the image gallery component. A report generator and viewer component generates a report based on snap shots of images taken within the examination viewer component. A print and post component prints the generated report to a printer operatively coupled to the computer, and/or posts the report as an HTML file to a web browser for retrieval over the Internet or an intranet.

Because of the increasingly fast processing power of modem-day computers, users have in droves been turning to computers to assist them in the examination and analysis of images of real-world data. For example, within the medical community, radiologists and other professionals who once examined x-rays hung on a light screen use computers to examine images obtained via ultrasound, computed tomography (CT), magnetic resonance (MR), ultrasonography, positron emission tomography (PET) single photon emission computed tomography (SPECT), magnetic source imaging, and other imaging techniques. Countless other imaging techniques will no doubt arise as medical imaging technology evolves.
Each of the above-identified imaging procedures generates volume images, although each relies on a different technology to do so. Thus, CT requires an x-ray source to rapidly rotate around a patient to obtain hundreds of electronically stored pictures of the patient. Conversely, for example, MR requires that radio-frequency waves be emitted to cause hydrogen atoms in the body's water to move and release energy, which is then detected and translated into an image. Because each of these techniques penetrates the body of a patient to obtain data, and because the body is three-dimensional, this data represents a three-dimensional image, or volume. In particular, CT and MR both provide three-dimensional "slices" of the body, which can later be electronically reassembled.
Computer graphics images, such as medical images, have typically, however, been modeled through the use of techniques that are inherently two dimensional in nature to some degree. One such technique is surface-rendering. Surface-rendering has its foundations in geometry-based modeling. For example, surface-rendering of a three-dimensional volume begins with a three-dimensional form of line drawing, a wireframe model, that is comprised of a network of lines and vectors. Surface-rendering replaces this network of lines and vectors with a mesh of polygons.
In the past two decades, significant advances of surface-rendering techniques have led to surface-rendered images having a great deal of realism. The polygonal model can be elaborately shaded to simulate the play of light and shadow on the object to be imaged, endowing each polygon with known or imagined surface properties. This gives the viewer the sense that he or she is looking through a window and into a virtual world.
However, surface-rendering techniques do just and only that--they render surfaces. Therefore, even with an intricately rendered and incredibly realistic surface-rendered image, there is nothing beyond the surface. The model is a hollow shell lacking the solid continuity that exists in the real world. Looking inside the shell reveals nothing.
Real-world, three-dimensional data also resists accurate imaging in accordance with geometry-based modeling techniques in other ways. Conventional geometric graphics techniques start with a simplified, extracted model of the contents of the original three-dimensional data set. The techniques must extract boundaries or surfaces from the data, and decide how to represent them with geometrical primitives (points, lines and polygons)--a process which can introduce distortions. Conventional geometric graphics techniques, therefore, assume a priori that every object within a three-dimensional domain has an already known shape or a shape which can be accurately determined.
However, three-dimensional data may not have clear boundaries that are easily represented with geometrical primitives. Thus, the user viewing such a surface-rendered imaging of the data is not viewing the data itself inasmuch as the user is viewing an interpretation of the data. Furthermore, surface-rendering requires great effort and time if presented with a complex data set, and if a faithful rendering is sought, even if the rendering is accomplished by a powerful computer.
In response to the deficiencies of geometric-based techniques such as surface-rendering, researchers have turned to three-dimensional-based volume-rendering techniques as a more accurate way to render images based on real-world data. Volume-rendering takes a conceptually simpler approach to rendering than does surface-rendering. Rather than overlay surfaces on a complex model of three-dimensional data, volume-rendering assumes that three-dimensional objects are composed of basic volumetric building blocks.
These volumetric building blocks are commonly referred to as voxels. Whereas, by contrast, the well known pixel is a picture element--i.e., a tiny two-dimensional sample of a digital image have a particular location in the plane of a picture defined by two coordinates--a voxel is a sample that exists within a three-dimensional grid, positioned at coordinates x, y, and z. The voxel has a "voxel value," as that value is obtained from real-world scientific or medical instruments. The voxel value may be measured in any of a number of different units, such as housefields, which are well known to those of ordinary skill within the art. For a given voxel value, a transparency value, to indicate its relative opacity vis-a-vis other voxels, as well as a color value, to indicate its color, may also be assigned (for example, in a particular tabling including such mappings).
Using volume-rendering, any three-dimensional volume can be simply divided up into a set of three-dimensional samples, or voxels. Thus, a volume containing an object of interest is dividable into small cubes, each of which contain some piece of the original object. This continuous volume representation is transformable into discrete elements by assigning to each cube a voxel value that characterizes some quality of the object as contained in that cube.
The object is thus summarized by a set of point samples, such that each voxel is associated with a single digitized point in the data set. As compared to mapping boundaries in the case of geometric-based surface-rendering, reconstructing a volume using volume-rendering requires much less effort and is more intuitively and conceptually clear. The original object is reconstructed by the stacking of voxels together in order, so that they accurately represent the original volume.
Although more simple on a conceptual level, and more accurate in providing an image of the data, volume-rendering is nevertheless still complex. A key requisite of volume rendering is the use of the entire voxel data set to create an image. In one method of voxel rendering, called image ordering or ray casting, the volume is positioned behind the picture plane, and a ray is projected perpendicularly from each pixel in the picture plane through the volume behind the pixel. As each ray penetrates the volume, it accumulates the properties of the voxels it passes through and adds them to the corresponding pixel. The properties accumulate more quickly or more slowly depending on the transparency of the voxels.
In another method, called object-order (or compositing or splatting), the voxel values are also combined to produce image pixels for display on a computer screen. The image plane is positioned behind the volume, and each pixel is assigned an initial background value. A ray is projected perpendicularly from the image plane through the volume to the viewer. As the ray encounters each successive layer of voxels, the voxel values are blended into the background, forming the image according to each voxel's interpreted opacity. The image rendered in this method as well depends on the transparency of the voxels.
Due to such variables present in the volume-rendering process, such as transparency as has been described, volume-rendering does not by itself ensure that the resulting image of data is visually realistic or is the image desired by the end user. The volume-rendering must be conducted correctly to ensure that the image is generated accurately. Moreover, different uses of the resulting image are such that the volume-rendering be performed differently from one use to another. For example, the volume-rendering of cardia tissue requires different opacity presets than does the volume-rendering of bone mass.
Furthermore, even within respect to the same use, volume-rendering may be required to be performed differently depending on the application of that use. For example, one physician may be interested in the most dense cardia tissue of a data set, while another physician may be interested in the least dense cardia tissue of the data set. In either case, the volume-rendering is conducted differently to accentuate the desired features of the data. Typically, color is also added to emphasize the desired features.
Unfortunately, however, the end users who can most benefit from the advantages of volume-rendering are not typically volume-rendering computer graphics experts. With respect to images rendered from sets of medical data (such as patient studies), the end user who can most benefit from volume-rendering techniques are physicians, such as radiologists, and technicians. Volume-rendering enables such users to have access to medical images that may display indicia of disease and medical problems otherwise unavailable to these doctors and technicians.
A physician, however, cannot be expected to master the subtleties of volume-rendering as a computer graphics expert may be expected to. Thus, providing physicians with a volume-rendering tool is ineffective if that tool is not easy to use, and does not permit the physician to quickly conduct a volume-rendering of an image of medical data with the correct presets and in the correct manner. Only in this way is volume-rendering of any use to the physician. That is, only if a physician, or other non-expert end user, can easily and quickly conduct a volume-rendering can it be expected that the physician or other non-expert end user will generate a rendered image that is capable of assisting the physician in making a more informed analysis, such as a medical diagnosis.

Advanced diagnostic viewer employing automated protocol selection for volume-rendered imaging


This method of generating precoders is used in optimising transmission capacity between an eNodeB and UEs in a DL MU-MIMO communication system. The method includes the steps of computing correlation values between pairs of precoding matrices (PMs) of the reported precoding matrix indicators (PMIs) (step 40), selecting a PM pair having a minimum correlation value (step 42). If the minimum correlation value is less than a lower threshold Tmin, the method uses a PM corresponding to the received PMI (step 44). If the minimum correlation value is greater than Tmin and less than an upper threshold Tmax, the method includes the steps of computing correlation values of the reported PMI and Channel Matrices (CMs) from a fixed codebook of representative CMs (step 48), selecting a CM pair having a maximum correlation value (step 52), and computing precoders from the selected CM pair (step 54).

In a DL MU-MIMO system the eNodeB transmits data to different UEs on the same time-frequency resources from multiple transmit antennas. To minimise interference between UEs, the eNodeB creates transmission beams through precoding. At the receiving site, a UE uses post-coding (decoding) to take (decode) its data.
In the DL MU-MIMO system, also the eNodeB can transmit different data to one UE on the same time-frequency resources from multiple transmit antennas. The number of the data for one UE is defined as rank.
In communication systems, feedback about the status of the downlink channel between a transmitter and a receiver is employed in order to optimise transmission of data over the downlink channel. The receiver determines the downlink channel status information (CSI) from received pilot signals, and then communicates this CSI to the transmitter, or UE determines the downlink CSI from received pilot signals, and then communicates this CSI to eNodeB, for use in altering the rank, precoding matrices, coding rate and modulation scheme for downlink transmission used in subsequent data transmissions. In 3GPP TS36.213 (V10.5.0), the channel status information includes rank indication (RI), precoding matrix indicator (PMI), and channel quality indicator (CQI). PMI and RI are used for DL MIMO systems.

Generating precoders for use in optimising transmission capacity between an eNodeBb and UE in a DL MU-MIMO communications system


In accordance with an embodiment, a system for processing an incoming signal for audio application includes a parameter extraction module coupled for receiving an incoming signal having a first frequency that is configured to extract at least one parameter from the incoming signal. The system includes at least one oscillator and at least one processing engine processing that receives a clock signal from the at least one oscillator. In accordance with another embodiment, a method is provided that performs a first processing with the clock signal and generates an oscillator control signal for adjusting the frequency of the clock from the oscillator adaptively depending on parameters of the incoming signal extracted or analyzed in the first processing.

The present invention relates to audio signal processing, and more specifically to a method and system for adapting a clock frequency based on parameters of incoming signals for the audio applications.
Today's digital hearing aids are typically constrained in terms of how much current the audio processing engine(s) and transducers can consume due to small energy constrained batteries being used to power the hearing aids. It is the objective of the hearing aid designer to design the audio processing scheme embedded in the hearing aid in such a way that the overall current consumption is minimized. Lower current typically results in longer battery life, which is of benefit for the hearing aid end user. Longer battery life means that batteries will not have to be changed as often, which leads to cost savings and less inconvenience for the end-user.
Hearing aids typically have one or more programmable and/or configurable audio processing engines, in which the audio signal is processed digitally to provide signal enhancements for the hearing impaired user. These audio processing engines typically operate at a fixed clock frequency that is determined by the frequency of a main oscillator or a divided frequency of the main oscillator frequency. A fixed oscillator frequency being used for a processing engine implies that the engine will be running at a fixed frequency regardless of the amount of processing that the engine performs.
However, typically the amount of processing required depends on the nature of the parameters of the signal that the engine processes. In one scenario the nature of the parameters may require less cycles of processing within a set time period compared to what is made available by the main oscillator. Likewise, in another scenario the parameters of the signal may require more cycles of additional processing within a set time period compared to what is made available by the main oscillator.
In the first scenario the need for only a few cycles of processing compared to overall cycles available within a given time period implies that the frequency of clock cycles required is lower than the actual frequency of clock cycles provided by the main oscillator.
Similarly, in the second scenario the need for more clock cycles of processing compared to overall cycles available within a given time period implies that the frequency of clock cycles required is higher than the actual frequency of clock cycles provided by the main oscillator.
The fact that the clock frequency cannot be adjusted adaptively based on the nature of the signal parameters means that in the case where few cycles are required for processing compared to overall available cycles there will be unused cycles available for additional processing. Unused cycles implicitly mean that the clock frequency is too high for the actual processing required. In turn, too high a frequency implies that current from the battery is being consumed un-necessarily, which again leads to reduced battery life time.
Similarly, the fact that the clock frequency cannot be adjusted adaptively based on the nature of the signal parameters means that in the case where higher number of cycles are required compared to overall available cycles there will not be enough cycles available for additional processing. This implicitly means that the clock frequency is too low for the actual processing required.
There is a need for a system that allows for clock frequency adjustments in a digital hearing aid through adaptive change of the clock frequency to one or more processing engines.

Method and system for parameter based adaptation of clock speeds to listening devices and audio applications

SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC


The present invention discloses a circuit for generating a wait signal in a semiconductor device. Even if an address input enable signal is synchronized with a clock and continuously or irregularly inputted, the circuit for generating the wait signal in the semiconductor device generates the wait signal suitable for a latency counter by using the finally-inputted address input enable signal. In addition, the circuit for generating the wait signal in the semiconductor device generates the wait signals having various pulse widths to be suitable for various latency counters, and enables the object wait signal earlier than data input or output by one clock, or simultaneously with data input or output.

1. Field of the Invention
The present invention relates to a circuit for generating a wait signal in a semiconductor device, and more particularly to, a circuit for generating a wait signal which can generate the wait signal in every data input or output state of a synchronous pseudo SRAM.
2. Discussion of Related Art
FIG. 1 is a waveform diagram showing a data input or output operation of a general semiconductor device.
Referring to FIG. 1, when a chip select signal /CS is logic low and a clock CLK rises, if an address input enable signal /ADV is logic low, an external address ADD and a write enable signal /WE are inputted. FIG. 1 is a timing diagram when a latency counter is 4. The latency counter defines a clock number for data input or output after an external address is inputted. In FIG. 1, an external address A0 is inputted and a data D0 is written in the fourth clock, and an external address A1 is inputted and a data Q0 is read in the fourth clock.
When a first address input enable signal /ADV is logic low, the address A0 and the write enable signal /WE are inputted, to perform the write operation. Here, a wait signal WAIT is enabled earlier than input time points of data D0, D1, D2 and D3 by one clock. In addition, when the clock CLK rises and the address input enable signal /ADV is logic high, a burst mode is internally executed. The burst mode is maintained by using an address inputted when the address input enable signal /ADV is logic low as a seed address. In the burst mode, the address is internally increased by one by using the seed address as a start address, thereby continuously performing the read or write operation.
When a second address input enable signal /ADV is low, the address A1 and a write enable bar signal become logic high, to perform the read operation. Here, the wait signal WAIT is enabled earlier than output time points of read data Q0, Q1, Q2 and Q3 by one clock.
In general, the wait signal WAIT maintains a high impedance level when the chip select signal /CS is logic high (standby state), is logic low when the chip select signal /CS is logic low, and is high when the clock CLK is inputted and the data is inputted or outputted.
In the conventional arts, a circuit for always generating a wait signal WAIT after three clocks from input of a low address input enable signal /ADV has been employed. However, when the clock CLK rises, if the low address input enable signal /ADV is continuously inputted, the wait signal WAIT maintains logic high after three clocks. That is, when the wait signal WAIT is enabled after three clocks from input of the address input enable signal /ADV, malfunction occurs during the operation.

Circuit for generating wait signal in semiconductor device


A method and apparatus for forming a centered bore within an intramedullary canal of a femur in preparation for the implantation of a prosthetic device. The apparatus comprises a substantially T-shaped device formed from a handle and an elongated rigid rod. The rod includes outwardly projecting fins at its distal end adapted to engage the interior wall of the cortex of the femur, thus centering the bore. The method includes preparing the femur for implantation by exposing the femoral neck and then inserting the rod into the intramedullary canal until the fins engage the cortex. If a device has a pair of fins disposed on the rod at 180.degree. relative to one another, the device is withdrawn, rotated ninety degrees, and reinserted into the intramedullary canal, again allowing the fins to engage the cortex. Once the bore is formed, it is used to guide compacting devices which shape and size a cavity within the femur to receive the prosthesis. Inasmuch as the bore is centered within the intramedullary canal, the prosthesis also is centered when it is attached to the femur.

1. Field of the Invention
The present invention relates to the implantation of prosthesis devices, and, more particularly, to the preparation of the femur for the implantation of a prosthetic hip replacement device therein by the formation of a centered bore in the intramedullary canal of the femur.
2. Related Art
Bone diseases and injuries to joints often make it necessary or desirable to replace a natural joint with an artificial prosthesis. One such replacement involves the fixation of a stem of a prosthetic hip joint within the femur. The femur contains an intramedullary canal filled with cancellous bone within which the stem of the prosthesis can be implanted. With such implantation, it is desirable to fix the stem to the femur centrally within the intramedullary canal.
In preparing the femur to accept the prosthetic device, the femoral head is removed to expose the intramedullary canal. A bore is formed in the canal and the femoral stem of the prosthesis is inserted into the canal and fixed to the femur by an interference fit, or by cement fixation.
When the prosthesis is joined with the femur, it is ideally centered within the intramedullary canal so that there is no undue pressure on the cortical bone which might cause pain to the recipient of the prosthesis and even result in bone penetration. The centering of the femoral stem of a prosthesis has been addressed. For example, Techmedia, a company located in Camarillo, Calif. has proposed using a small plastic centering device attached to the tip of the femoral stem. However, the attachment of such a device to a femoral stem creates several associated problems. For example, such plastic attachments increase the overall cost of the prosthesis. Additionally, the attachment of a plastic centering device to a metal femoral stem often causes some weakening of the stem, thus increasing the chance of deterioration of the fixation of the prosthesis to the femur and the likelihood that the prosthesis will need replacement.

Method and apparatus for forming a centered bore for the femoral stem of hip prosthesis


Provided is a slow-release tablet including cilostazol as a pharmacologically active component, which is efficacious in suppressing aggregation of blood platelets and promoting vascular relaxation by inhibiting phosphodiesterase types. The slow-release cilostazol tablet has an extended elution time so that the slow-release cilostazol tablet can be taken once daily for convenience of drug use, and minimizes the manifestation of headache which is one side effect caused when women, the elderly and children take conventional cilostazol preparations so that the convenience of drug use can be improved. Also, the slow-release cilostazol tablet exhibits a stable elution pattern with no variation in elution rate according to changes in pH in the stomach and intestines, as well as an effect of delaying the release of a drug, using a mixture of hydroxypropyl methylcellulose and a carbomer as a release-controlling polymer.

As a quinolinone-based compound, cilostazol (6-[4-(cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4-dihydro-2(1H)-quinolinone: Chemical formula 1) has an efficacy in controlling aggregation of blood platelets and promoting vascular relaxation by inhibiting phosphodiesterase types. Also, cilostazol is known to be useful in preventing diseases such as arteriosclerosis by suppressing the growth of vascular smooth muscle cells that have migrated to vascular endothelial cells.

Cilostazol functions to suppress the primary aggregation of blood platelets caused by ADP, epinephrine and the like in blood platelets isolated from a mouse, a rat, a rabbit, a dog and a human and dissociate a blood platelet aggregate. Also, cilostazol functions to suppress the aggregation of blood platelets induced by ADP and collagen when administered orally to a beagle, and also suppress the aggregation of blood platelets induced by ADP, collagen, arachidonic acid and epinephrine in blood platelets isolated from a patient with a chronic arterial occlusive disease (Buerger's disease, arteriosclerosis obliterans, diabetic peripheral angiopathy, etc.) when administered orally to the patient. The effect of cilostazol to suppress the blood platelet aggregation is manifested immediately after administration of the cilostazol, and maintained by repeated administration of the cilostazol. When the administration of the cilostazol is suspended, suppressed aggregation of the blood platelets returns to its original level with a decrease in its concentration in blood plasma without a rebound phenomenon (rise in aggregation).
The action mechanism of cilostazol is as follows. Cilostazol functions to suppress the release of serotonin from rabbit blood platelets, but has no effect on migration of serotonin and adenosine into the blood platelets. Also, the cilostazol functions to suppress the aggregation of blood platelets caused by thromboxane A2 (TXA2) without affecting an arachidonic acid metabolism in the blood platelets. This indicates that the cilostazol functions to inhibit cAMP-PDE (cyclic AMP phosphodiesterase) activity in blood platelets and vascular smooth muscles, thereby exhibiting an anti-blood platelet action and a vascular dilatation action.
Conventional cilostazol preparations have a disadvantage in that they have poor patient compliance when administered twice daily. Also, immediate-release cilostazol preparations have a disadvantage in that the drug is rapidly and irregularly released when administered orally. Thus, it is known that these cilostazol preparations cause side effects such as headache, heavy headedness and tachycardia with a sudden increase in cilostazol concentration in blood (see Am J Cardiol 2001; 87(suppl): 28D-33D and US 2002/0058066 A1). Since the cilostazol is poorly water-soluble and also has a reduced absorption rate in the lower small intestine, a conventional release-controlling preparation using the cilostazol has a disadvantage in that its bioavailability may be deteriorated as a whole. Also, WO 2000/57881 discloses a method of improving an absorption rate of cilostazol in the lower small intestine using a preparation in which cilostazol in a fine powder form is dispersed and/or dissolved together with a dispersing agent and/or a solubilizing agent.
Conventional cilostazol tablets cause side effects such as headache, tachycardia and heavy headedness due to a high elution rate immediately after their administration. Therefore, there is the high necessity for cilostazol prepared into a slow-release tablet, and there is a need to develop a slow-release cilostazol tablet which simply delays the release of a drug and also exhibits a stable elution rate when taken once daily.

Slow-release cilostazol tablet having an improved elution rate and minimal side effects


An improved resilient pour spout for paint cans and similar containers that seals off the groove into which the lid of the container mates while preventing the liquid contents from flowing down the surface of the container. When not in use, the spout is stored on the sealed container in an inverted position so as not to take up additional space on the storage shelf. In this position, the trough of the spout will be tight against the container while its exposed outer surface provides a surface for retailers to display advertising. The spout also acts as a base for a second container that may be stacked concentrically above, thereby safely and neatly interconnecting the two containers. The pour spout has the option to be molded in a set so as to provide a carrier for the bulk shipment of several containers thereby reducing the cost of packaging.

The present invention relates generally to assist in pouring a liquid, such as paint, from a can. More specifically, the present invention relates to an integral pour spout mounted flush with the can so as to provide a means to facilitate vertical storage and shipping as well as a surface to display graphics.
It is well known that the standard paint container consists of a one-gallon can with a metal press-on lid. This lid has a formed flange that fits into a circular groove around the circumference of the container thereby sealing the paint within. After removal of the lid, paint may be poured out of the can or a brush may be dipped into the paint whereby removing the paint directly from the can. In both instances, paint is inadvertently transferred into the circular groove that accepts the lid. This paint must be adequately removed from the groove prior to engaging the formed flange of the lid. If this is not done, the paint will likely harden around the flange of the lid making it difficult to remove when re-opening. In addition, while pouring paint from a can, the paint is susceptible to dripping down the exterior surface of the can. It is known that a lip to assist in pouring paint can be attached around the circumference of the container to prevent paint from being transferred into the groove. For example, U.S. Pat. No. 3,894,650 to Crump, U.S. Pat. No. 4,240,568 to Pool, U.S. Pat. No. 5,012,960 to Arnold, U.S. Pat. No. 5,641,089 to Palank, and U.S. Pat. No. 6,253,951 to Pruckler disclose an annular ring that attaches to the open rim of a can. While these devises will prevent the liquid contents from entering the groove around the top of the container they will not prevent the liquid contents from dripping down the exterior surface of the can.
As an alternative to protecting only the rim of the can, several other patents disclose a means of attaching a spout to one side of the rim. For example, U.S. Pat. No. 1,952,288 to Saxon, U.S. Pat. No. 2,767,891 to Beadles and U.S. Pat. No. 5,195,662 to Neff disclose a means of attaching a U-shaped trough to the open rim of the can. While these devises will assist in pouring the liquid from the container, they suffer the disadvantage of leaving the remaining rim and groove of the can unprotected and susceptible to paint transfer.
Several patents have combined the benefits of protecting the groove while providing a spout to assist in pouring the liquid from the container. For example U.S. Pat. No. 4,203,537 to McAlister, U.S. Pat. No. 4,907,714 to Gatz and U.S. Pat. No. 5,234,133 to Kensey disclose an annular rim for protecting the groove that combines a pour spout. In all cases, the prior art suffers the disadvantage of a spout that has to be removed from the top of the can and stored separately from the can itself when not in use. This takes up additional storage space and could result in misplacement of the spout if not stored in close proximity to the can.
Several patents have attempted to address the issue of storage. For example U.S. Pat. No. 2,720,346 to Compton discloses a method to store a spout on the exterior of a container in the inverted position by utilizing pressure adhesive tabs. U.S. Pat. No. 3,221,955 to Banaszak utilizes an integral clip that is adapted to be snapped onto the outer edge of the container so the attachment may be stored with the container in a hanging position. U.S. Pat. No. 3,239,113 to Knize engages the entire rim of the container and acts as a new attachment base for the press-on lid. Finally, U.S. Pat. No. 3,469,735 to Burt discloses a means to store a protector of the container rim in the inverted position by engaging with the metal press-on lid. These patents demonstrate a need for a spout that is stored directly on the can to reduce the possibility of the spout being lost or misplaced. However, in each case the attachment takes up additional storage space on the container and has the disadvantage of not being able to accommodate the storage of additional containers.
Paint containers are typically stacked in the retail store, one on top of the other. The containers do not interlock so this structure becomes unstable and creates a safety concern if more than a couple of cans are stacked together. It is very difficult and time consuming for stock personnel to stack the containers concentrically on top of one another so it is seldom done. The visual image of paint containers precariously stacked one on top of the other, is one of disorder creating an unkempt appearance. It has been demonstrated by U.S. Pat. No. 3,173,574 to Goldsmith, U.S. Pat. No. 3,913,785 to Pattershall and U.S. Pat. No. 3,980,213 to Ramsay that by attaching a properly formed cover or lid to the opening of a container it is possible to stack additional containers in a stable position above. Thus there is a further need for an integral spout that allows a means of alignment of the paint containers so that they may be stacked concentrically on top of one another while structurally interlocking.
Paint containers are shipped for retail distribution in bundles. For single gallon containers a bundle generally consists of four cans packaged in a box or in a cardboard tray. The boxes and trays can then be palletized for bulk shipments. The cardboard that makes up the boxes and trays is expensive. In addition, the boxes take up a lot of space when discarded and result in material waste. It is well known that cylindrical containers can be combined together such as in a six-pack of beverage cans. Such a multi-packaging device is disclosed in Pat. No. 4,462,494 to Cunningham. Thus there is an additional need for an inexpensive method of packaging the paint containers that will also eliminate the volume of cardboard waste that currently exists.
Another device used by painters is a stirring stick used for mixing paint. These include hand held mixing paddles as well as devices that are inserted into electric hand drills. Such drill operated devises are disclosed in U.S. Pat. No. 3,733,645 to Seiler and U.S. Pat. No. 4,083,653 to Stiffler. Thus there is a further additional need to provide such a mixing device integral with the spout attachment.
The paint container and lid are very generic in construction. One paint manufacturer may use a container that is indistinguishable from another paint manufacturer. The only distinguishing element on the container is the label, which typically encircles the entire can from top to bottom. This label leaves little or no room on the container for the retailer to display a trademark, logo and the like. In addition, once the paint leaves the retail store, the identity of where the paint was purchased has been lost. Thus there is a need for integral graphics which can be applied to the container without altering the manufacturer's label so as to display the retailer's trademark, logo and the like.

Integral pour spout for paint cans and similar containers


A system and computer implementable method for updating content on servers coupled to a network. The method includes updating an origin server with a version of files used to provide content, retrieving data that indicates an action to be performed on one or more cache servers in conjunction with updating the origin server, and performing the action to update entries in the one or more cache servers. Each entry in each cache server is associated with a subset of the content on the origin server and may include an expiration field and/or a time to live field. An example of a subset of content to which a cache entry may be associated is a Web page. Cache servers are not required to poll origin servers to determine whether new content is available. Cache servers may be pre-populated using push or pull techniques.

Often, source files for Web content servers are coded by multiple programmers on remotely located (stage) source servers. It is not unusual for one programmer(s) to code "HTML" files on one source server while another programmer(s) creates executable and/or image files on another source server. Once a programmer debugs a newly created/edited update file, it is eventually distributed to each content server and placed in a corresponding file directory. Historically, the distribution of the current version of a set of "updated" or new files from remotely located source servers through the Internet to content servers has proven to be a difficult task for several reasons. One reason is that the file directory structure and hardware configuration can vary between individual Web content servers. In this case, the distribution of a set of files for each Web content server must be separately organized according to each server's file directory structure and hardware capabilities. Another reason is that the actual size of the set of files may be so large that their distribution is relatively slow on a network with limited bandwidth capabilities. Another reason relates to how cache servers caching the content should be updated.

Method and system for automatically updating the version of a set of files stored on content servers


A tape measure (10) including an electronic keypad (20) and display (24) for recording and viewing measurements is disclosed. The keypad includes up (44) and down (46) buttons, save (48) and recall (50) buttons, a set button (46) and a clear/on button (40). The up and down buttons are used to selectively increment and decrement numeric values representing units of measurements, which are displayed on the display. Measurements are entered and displayed in feet, inches, and sixteenths of an inch in the English system, or in metric units. After manually measuring a distance using a coiled measuring tape, a user presses the up and down buttons to specify the distance measured, then presses the save button to store the measurements. The recall button is used to recall previously stored measurements.

Carpenters frequently take measurements with a tape measure, recording the measurements with a pencil on scraps of paper, lumber, or any convenient surface. Recorded measurements may be misplaced, covered up, illegible, or left in an inconvenient location. Carpenters may have difficulty recording the measurements. For example, the pencil may break or be lost, or the carpenter may be wearing heavy gloves that make writing difficult.
It is desirable to have a self-contained measurement recording device that is an integral part of the tape measure and does not require a separate recording instrument, such as a pencil. It is also desirable that the recording device be easy to use, preferably with one hand, even when the carpenter is wearing heavy gloves.

Tape measure with manual entry electronic measurement recording feature


A magnetic stand for a tablet device is disclosed. The magnetic stand is configured to rigidly hold a portion of the tablet device in place and to shield the magnetic field from adversely affecting nearby devices susceptible to strong magnetic fields. The shielding portion of the magnetic stand allows for significant increases in magnetic field strength when compared to similarly configured, unshielded products.

1. Field of the Described Embodiments
The described embodiments relate generally to an apparatus for supporting a tablet device. In particular an apparatus for magnetically attaching a tablet device to a supporting structure is disclosed.
2. Related Art
Tablet devices are used in an increasingly wide range of applications. In many of these applications a way for conveniently mounting the device is required. A number of manufacturers have tried to produce such a device; however since most tablets have no built in mounting mechanism, mounting devices tend to be somewhat cumbersome and generally do not allow for easy removal.
Therefore, what is desired is a way for securely attaching a tablet device to a stand where it can be removed and replaced with ease.

This patent is subject to a terminal disclaimer.


A disposable face shield with a shield with a plurality of cuts is described. A foam member is connected to the shield to provide added comfort. The foam member may contain a plurality of openings extending through the member. The openings allow for increased air movement around the shield. The cuts in the shield may be above the foam member to create tabs which may be bent to at least partially cover the openings that extend through the foam member. Additionally, a pair of parallel cuts may be made on either side of the shield, the cuts adjustably engaging an elastic strap. This configuration allows the elastic strap to be comfortably adjusted to conform to a number of different sized heads.

1. Field of the Invention
The present invention relates in general to the field of face shields. More particularly, the present invention relates to a disposable face shield with a shield with a plurality of cuts, a foam member, and an adjustable elastic band.
2. Discussion of the Related Art
Face shields are used in a variety of industries to prevent splatter of liquids or materials against a user's face. For instance, these types of shields are commonly used in medical and dental applications during procedures or surgeries to prevent splatter of a patient's blood or other bodily fluids in the operator's face. During an operation, a face shield that is soiled, dirtied, or contaminated needs to be quickly disposed of and replaced with a clean face shield. Therefore, it is most convenient to have disposable face shields made of inexpensive materials that can quickly be replaced. Most face shields are made of a flexible material such that they can easily conform to a variety of different users' heads regardless of the size or shape. Because the plastic does not comfortably rest on a user's head, face shields typically have a cushion or barrier that is located between the shield and the user's forehead. Even more importantly, the cushion or barrier provides an offset such that the shield does not abut a user's nose. The offset also provides the necessary space for a user's eyeglasses.
Face shields can be mounted to a user's head by a number of different mechanisms, for instance, by frames similar to those used for glasses, or other hooks or loops. Alternatively, straps or strings can be used to secure the shield to the user's head. Many shields feature elastic straps as they allow for stretchability to conform to different shaped heads. Elastic straps may be attached directly to the shield by glue or other fasteners, which prevents adjustability. However, a face shield with an adjustable mounting mechanism is appealing as it makes it easier for a wide variety of individuals to comfortably wear the same style of face shield. As such, it is desirable to have a shield with an elastic strap that is easily adjusted so that the shield is securely attached to a variety of different users' heads.
Another prevalent issue with face shields is that they easily fog due to the user's breathing. Obviously, this is a problem when a user needs a clear view during a medical procedure. Some shields have provided vent holes or openings along the top of the shield, for instance, along the cushion or barrier between the shield and the user's forehead. Such configurations allow for greater air movement between the shield and the user's face. Still, there is risk that splatter could enter these holes. Therefore, it is desirable to have a face shield, with vent holes that prevent fogging of the shield while minimizing the risk of splash contamination into the holes from above.


A pressure sensitive adhesive composition includes (A) 0.1% to 5% an anchorage additive and (B) 95% to 99.9% of a silicone pressure sensitive adhesive composition. This pressure sensitive adhesive composition can be cured to form a pressure sensitive adhesive. When cured on a backing substrate, the resulting adhesive article is useful for protecting electronic devices during fabrication, shipping, and use.

Protective films and carrier tapes are two major applications in the electronics fabrication industry for silicone pressure sensitive adhesives. Usually the thickness of pressure sensitive adhesives (PSAs) in protective films and carrier tapes is relatively thinner than traditional tape applications. Commercially available PSAs for these applications are predominantly solvent based.
Non-uniform adhesive coverage on substrates may suffer from the drawback of having too high adhesion for protective films in which the PSAs may cause damage to protected substrates when the protective film removed. Moreover, the uneven adhesive surface may suffer from the drawback of having unstable adhesion for carrier tapes during processing protection, in which may cause surface damage or quality issues in surface protection and/or process masking when the carrier tape is removed.

Anchorage additive and methods for its preparation and use


A field-effect transistor includes: a carrier supply layer supplying carriers; a Schottky contact layer forming a Schottky barrier; and an intermediate layer formed between the carrier supply layer and the Schottky contact layer. Here, the intermediate layer has an electron affinity which is higher than an electron affinity of the carrier supply layer but lower than an electron affinity of the Schottky contact layer.

(1) Field of the Invention
The present invention relates to a field-effect transistor (FET), especially to an FET for use in a high-frequency communication device.
(2) Related Art
Conventionally, a Metal-Insulator-Semiconductor Field-Effect Transistor (MISFET), which is an insulated-gate FET, has been utilized in an electronic device such as a silicon semiconductor integrated circuit device.
When compared with a silicon (Si) Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) of the same size, an FET formed using gallium arsenide (GaAs) or a combination of GaAs and aluminum gallium arsenide (AlxGa1-xAs) provides higher-speed performance, and is more suitable for a microwave amplifier and a high-speed logic IC. This is because group III–V compound semiconductors such as GaAs, InP and GaN have a higher (approximately five- to six-fold) electron mobility than Si. An FET formed using a semiconductor with such a high electron mobility achieves excellent high-frequency characteristics.
However, a MOSFET or MISFET formed using a group III–V compound semiconductor such as GaAs has a problem regarding interface states. To be specific, interface states are formed at an interface between an insulating film and a compound semiconductor. Because such interface states lower mutual conductance (gm), the MOSFET or MISFET can not achieve good performance.
For this reason, a Metal Semiconductor Field-Effect Transistor (MESFET) or a High Electron Mobility Transistor (HEMT) formed using a compound semiconductor such as GaAs is used for a constituent of an electronic device such as a high-frequency amplifier and an ultrahigh-speed integrated circuit device. For example, a MESFET is used as an amplifying element in a mobile communication device such as a mobile telephone, and a HEMT is used as an amplifying element in a receiving antenna for satellite broadcasting.
In particular, a HEMT provides high-speed performance and low noise figure, since two-dimensional electron gas (2DEG) which is produced in a channel layer made of high-purity InGaAs and has a high electron mobility is used as carriers. To be specific, a layer in which electrons are generated (carrier supply layer) and a layer in which electrons move (the channel layer) are separated from each other. Therefore, electrons can move stably at high speed from a source to a drain without colliding with impurities, thereby reducing noise figure.
Here, to increase a surface charge density of the 2DEG accumulated in the channel layer, an energy barrier formed at an interface between the channel layer and the carrier supply layer needs to be made as high as possible.
In the HEMT, a Schottky contact layer and an ohmic contact layer are formed, in the stated order, on the carrier supply layer during a wafer epitaxial growth. The ohmic contact layer is partially removed, so as to partially expose the Schottky contact layer. A gate electrode is provided on the exposed surface of the Schottky contact layer. Furthermore, a source electrode and a drain electrode are formed on the ohmic contact layer so as to oppose each other with the gate electrode therebetween.
As described above, the Schottky contact layer, on which the gate electrode is formed, is sandwiched between the carrier supply layer and the ohmic contact layer. Here, a high Schottky barrier is formed between the gate electrode and the Schottky contact layer. A height ΦB of the Schottky barrier is defined as a difference between an electron affinity φs of the Schottky contact layer and an electron affinity φm of a metal forming the gate electrode, as indicated by the following formula (1):ΦB=φm−φs  (1)
If the Schottky barrier ΦB is sufficiently high, electrons in the carrier supply layer and the 2DEG accumulated in the channel layer are difficult to overcome or pass through the Schottky barrier ΦB to flow into the gate electrode. This can reduce leakage currents caused when a reverse bias is applied, and improve resistance to dielectric breakdown.
The Schottky contact layer forms a path of electric currents flowing between the source electrode and the drain electrode. In detail, electrons need to go through the Schottky contact layer in order to reach the channel layer from the source electrode, and in order to reach the drain electrode through the channel layer. Therefore, while forming a high Schottky barrier (high resistance) with respect to the gate electrode as stated above, the Schottky contact layer is required to provide a lowest possible resistance with respect to the source electrode and the drain electrode. To meet these contradictory needs, the ohmic contact layer is formed between the Schottky contact layer and the source and drain electrodes. As a result, an ohmic contact, which has a low resistance, is formed between each of the source and drain electrodes and the ohmic contact layer. Hence, a resistance between the source and drain electrodes is reduced.
Furthermore, the Schottky contact layer is conventionally made of the same material as the carrier supply layer, which is AlGaAs. Therefore, the Schottky barrier ΦB is relatively high in the HEMT including the Schottky contact layer made of AlGaAs. This results in reduction in leakage currents caused when the gate electrode is reverse-biased.
However, the HEMT including the Schottky contact layer made of AlGaAs has a problem of frequency dispersion of drain currents. In other words, a maximum drain current density decreases when a high-frequency signal is applied. Frequency dispersion of drain conductance causes a degree of amplification of a circuit to vary in accordance with an operating frequency. This makes it impossible to amplify a pulse appropriately.
A possible reason for such frequency dispersion of drain currents is that AlGaAs has a high interface state density. AlGaAs forms many interface states, that is to say, electron trap levels, at an interface between different layers. Electrons are trapped by the electron trap levels at the interface. Each of the electron trap levels releases trapped electrons into a conduction band after a lifetime of the electron trap level. Here, the lifetime of the interface states formed by AlGaAs is relatively long. If an FET with such many electron trap levels having a long lifetime operates at a frequency corresponding to the lifetime, the electron trap levels significantly affects frequency performance of the FET.
For example, some electron trap levels of a GaAs substrate have a long lifetime of several milliseconds. If an operating frequency of several KHz is set as a criteria, there is a large difference in performance of the FET between when operating at frequencies lower and higher than the criteria. This causes frequency dispersion of drain conductance.
The problem of the frequency dispersion can be solved by a technique disclosed in Japanese patent application H15-032038. This technique uses InGaP for a Schottky contact layer, instead of AlGaAs.
FIG. 5 illustrates a cross-section of an FET 50 disclosed in the patent document. As shown in FIG. 5, the FET 50 is formed by providing an AlGaAs buffer layer 61, an n-AlGaAs barrier layer 62, an undoped InGaAs channel layer 63, an n-AlGaAs carrier supply layer 64, an undoped InGaP Schottky contact layer 65, and an ohmic contact layer 66 which has an opening so that part of the Schottky contact layer 65 is exposed, in the stated order, on a GaAs semiconductor substrate 60.
Furthermore, a gate electrode 67 is formed so as to be in contact with the Schottky contact layer 65, and a source electrode 68 and a drain electrode 69 are each formed so as to be in contact with the ohmic contact layer 66.
The Schottky contact layer 65 is made of InGaP, which has a lower interface state density than AlGaAs. Therefore, the number of interface states formed at an interface between the Schottky contact layer 65 and the gate electrode 67 can be reduced. This can reduce frequency dispersion of drain currents.
However, the conventional FET 50 has the following drawback. A discontinuity in energy of a conduction band (hereinafter referred to as a band discontinuity) occurs at an interface between the AlGaAs carrier supply layer 64 and the InGaP Schottky contact layer 65. This band discontinuity blocks electrons passing through the interface between the carrier supply layer 64 and the Schottky contact layer 65. Therefore, a source resistance Rs of the FET 50 increases, and mutual conductance (gm), which is one of the properties of the FET 50, accordingly decreases. As a result, the FET 50 can not obtain a sufficient current drive power.
It is known that the amount of a band discontinuity at an interface between different layers is generally determined by materials of the layers, and that, if the layers are each made of mixed crystal, a composition of each of the layers determines the amount of the band discontinuity. Here, the mutual conductance (gm) is calculated by the following formula (2):gm=gmi/(1+Rs×gmi)  (2)
In the formula (2), gm, gmi, and Rs respectively denote mutual conductance, intrinsic mutual conductance, and a source resistance. If the carrier supply layer 64 is made of Al0.25Ga0.75As, as an example, a band discontinuity of approximately 0.3 eV occurs at the interface between the AlGaAs carrier supply layer 64 and the InGaP Schottky contact layer 65, as shown in FIG. 6.
In FIG. 6, an energy level of a conduction band is plotted on the vertical axis, and the layers composing the FET 50 are plotted on the horizontal axis in the order of the lamination on the substrate 60.

Matsushita Electric Industrial Co., Ltd.


A process for producing synthetic hydrocarbons that reacts carbon dioxide, obtained from seawater of air, and hydrogen obtained from water, with a catalyst in a chemical process such as reverse water gas shift combined with Fischer Tropsch synthesis. The hydrogen is produced by nuclear reactor electricity, nuclear waste heat conversion, ocean thermal energy conversion, or any other source that is fossil fuel-free, such as wind or wave energy. The process can be either land based or sea based.

1. Field of the Invention
The present invention relates to hydrocarbon production and, more specifically, to a process to make synthetic liquid hydrocarbons from carbon dioxide, obtained from seawater or air, and hydrogen from water without the use of fossil fuels in any step of the process. Description of the Related Art
2. Description of Prior Art
The United States Navy uses over a billion gallons of liquid hydrocarbon fuel each year. The fuel is procured from petroleum refineries and suppliers around the world and is transported to its final location of use. This can involve fuel shipments over thousands of miles and many weeks of transport. Moreover, implementing fuel cells on ships requires a hydrogen carrier such as liquid hydrocarbon fuels that are extremely low in sulfur content since this contaminant will poison the fuel cell fuel reformer.
Although the idea for developing synthetic liquid hydrocarbon fuels has been discussed for at least the last 30 years, there has not been an apparent need to produce them because of the availability, ease of processing, and high-energy conversion efficiency of fossil fuels. However, the fossil fuel market is changing. One reason for this change is the ongoing political instability in oil producing regions. Another reason is the increasing worldwide energy demand.
There are several disadvantages to using fossil fuels. First, fossil fuels are a limited resource that cannot be regenerated. Additionally, hydrocarbon fuels made from fossil fuels may contain highly undesirable sulfur, nitrogen, and aromatic compounds. When these fuels are burned, sulfur, nitrogen, and particulates are released into the air, which leads to the formation of acid rain and smog.
There are several well-established processes for direct hydrogenation of gases such as CO or CO2 to produce hydrocarbon fuels. One of the most successful was developed in Germany in the 1920s by Franz Fischer and Hans Tropsch. In 1938, early German plants produced 591,000 metric tons per year, approximately 5×106 barrels per year or approximately 2×108 gallons/year, of oil and gasoline using the Fischer-Tropsch process, which reacts carbon monoxide and hydrogen with a catalyst to produce liquid hydrocarbons and water. The problem with these methods is that they use fossil fuels to produce the CO, CO2, and H2 used.
Additionally, well-known methods have been developed to produce methanol from carbon dioxide and hydrogen. One successful process is the Lurgi process. Methanol can also be used as a feedstock to produce traditional automotive gasoline. The problem with these methods is that the flash point of methanol is 11° C. and the flash point of gasoline is well below 0° C. Therefore, these methods cannot be used at sea, since the International Maritime Organization and the U.S. Navy require a minimum 60° C. flash point for all bulk flammable liquids on ships.

Process and System for producing synthetic liquid hydrocarbon fuels

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


An optical coupling structure includes a common substrate carrying a pair of parallel ridges as a first engagement structure, a first sub-carrier mounted on the common substrate, the first sub-carrier carrying a second engagement structure including a plurality of groove pairs such that one of the groove pairs engage with the ridges forming the first engagement structure, and a second sub-carrier mounted on the common substrate. The second sub-carrier carrys a third engagement structure including a plurality of groove pairs such that one of the groove pairs engage with the ridges. The groove pairs are selected such that an optical component held by the first sub-carrier aligns optically to an optical component held by the second sub-carrier.

The present invention relates to an optical coupling structure for optically coupling a plurality of optical components and a fabrication process of such an optical coupling structure. More particularly the present invention relates to an optical coupling structure carrying a plurality of optical components on a plurality of flat sub-mounts with an exact optical alignment between the optical components, which plurality of flat sub-mounts in turn being mounted on a flat substrate in an exact optical alignment.
In optical-fiber telecommunication networks or optical information processing systems, various optical apparatuses are constructed by assembling various optical components. For example, an optical source used in an optical fiber network includes a laser diode and a lens provided in an optical alignment with an optical fiber for injecting an optical beam produced by the laser diode into the optical fiber. On the other hand, there are optical systems for use in laser beam printers or optical disk drives, in which a laser diode is optically coupled to a lens or other optical components. Thus, there exists a persisting demand for a simple fabrication process of such optical apparatuses.
Generally, there are two known types of optical coupling structures for achieving a desired optical coupling of optical components on a flat slab member, which will be referred to hereinafter as a "substrate."

Optical coupling structure and a fabrication process thereof


A television receiver includes circuitry that quickly derives a channel map for a DTV receiver. The apparatus includes tuner that is controlled by a processor in the television receiver to periodically test each channel frequency to determine the strength of the signal at that frequency. If the signal strength exceeds a threshold value, the channel map is updated to indicate that a channel exists at that frequency. The processor monitors the signal recovered by the tuner during normal television viewing for valid program information. If the processor does not detect valid program information for a channel in the program map, the threshold value used by the processor to build the channel map is raised. If the processor detects valid program information then information on the estimated noise level in the received DTV signal is used to update the threshold value. In one embodiment of the invention, the television receiver includes both a main tuner and an auxiliary tuner. The auxiliary tuner is controlled to periodically scan the television channel frequencies to update the channel map, even when the main tuner is being used by a viewer who is watching television.

The number of television programs that a viewer may receive at any given time has increased geometrically in the last few years. Conventional analog television systems such as those conforming to the National Television Standards Committee (NTSC) and Phase Alternate Line (PAL) standards transmit one program per 6 MHz or 8 MHz channel. Recently, digital television signal processing techniques have been developed that allow multiple programs to be transmitted in each 6 MHz channel. Furthermore, there are now many sources of television signals In addition to the conventional terrestrially broadcast signals, a viewer may receive television signals, for example, via wired cable systems, several different types of satellite systems, so-called wireless cable systems and, in the near future, via a global information network, such as the Internet.
Conventional cable television systems are capable of delivering 140 six MHz channels and some systems are capable of delivering over 200 channels via a coaxial cable. Presently, new technology is being investigated to increase the number of programs that can be delivered to the home. This is being done via two technologically strategic moves. The first is to increase the allocated bandwidth to 1 GHz (which provides for 150 six MHz channels). The second is to use video compression to configure a channel to carry up to 10 minor channels in one 6 MHz wide major channel. Channels that include a plurality of minor channels are also known as multiprogram channels. Typical numbers that are used in the industry estimate that about 500 programs can be delivered to the home over a single coaxial cable. Fiber optic cable provides many times the bandwidth of a coaxial cable and promise to be able to provide several thousand programs. In the same way, increased bandwidth for satellite systems may allow a viewer to receive upwards of 1,000 six MHz channels, each channel containing up to ten minor channels.
The digital coding that allows a single television channel to contain more than one minor channel also makes the channels more difficult to decode. While an analog television receiver may be able to tune to a new channel and recover a television signal in a matter of milliseconds, a DTV receiver needs more time. This is because a typical digital television signal is first encoded according to the standard adopted by the Moving Picture Experts Group (MPEG) to provide a digital bit-stream. The digital bit stream is then used to modulate a radio frequency (RF) carrier using quadrature amplitude modulation (QAM) or trellis coded vestigial side-band (VSB) modulation techniques. In order to receive a program transmitted on a DTV channel, therefore, a receiver must tune the receiver to the channel frequency, phase-lock the tuner to the DTV signal, demodulate the signal and then decode the demodulated signal. For a typical DTV signal, this process may take four to ten seconds for each major channel.
Television receivers manufactured in the last few years typically include a tuning memory that stores tuning information for active channels which may be received by the television receiver. This information is commonly referred to as a channel map. The tuning memory may store, for example, a list of channels for which valid RF television signals are present and tuning information that may be used to set the television tuner to quickly recover the RF carrier. This list is used to step sequentially through channels when a viewer is watching television. As a viewer presses the channel up key on the remote control, a microprocessor in the television receiver accesses the channel map and provides information for the next channel in the list to the tuner.
In a typical analog television receiver, the channel map is derived using a set-up function accessed via the control menu of the receiver. The set-up function sequentially scans the tuner from the lowest channel frequency to the highest channel frequency, attempting to tune each channel as it is encountered. Only channels that provide valid television signals are added to the channel map.
While this system works well for analog television receivers, it may not be appropriate for DTV receivers. First, as described above, it takes considerably more time for a digital television decoder to determine if a valid signal exists at a channel frequency. Second, the existence of valid programming at the various channel frequencies may change more often in a DTV environment, such as a satellite broadcast, than in a traditional terrestrial broadcast environment, for example, due to changing weather conditions or sun-spot events. These events may affect the strength of the received satellite signal and make some of the channels temporarily unavailable. Thus, for a DTV receiver if conventional methods are used to generate a channel map, not only will it take more time but it will need to be done more often.

Method and apparatus for deriving a channel map for a digital television receiver


Disclosed is a process for preparing polymers and copolymer blocks of conjugated dienes with varying amounts of branching comprising the use of a microstructure control agent and a microstructure control agent deactivant. The polymerization can be started with or without a microstructure control agent. At some point in the polymerization prior to the completion of the addition of the conjugated diene to the polymer, the microstructure control agent can be deactivated, either partially or completely, resulting in a polymer or copolymer block having a region of less branching adjacent to a region of more branching. Preferred microstructure control agent deactivants are metal alkyls such as triethyl aluminum.

1. Field of the Invention
The present invention relates to conjugated diene polymers and conjugated diene copolymer blocks, and a process for preparing them. The present invention particularly relates to butadiene and styrenic block copolymers and a process for preparing them.
2. Background of the Art
The preparation of conjugated diene polymers, particularly in the form of block copolymers based upon more than one monomer, is well known. In a synthetic process, an initiator compound is used to start the polymerization of one monomer. The reaction is allowed to proceed until all of the monomer is consumed resulting in a living homopolymer. To this living homopolymer is added a second monomer that is chemically different from the first. The living end of the first polymer serves as the site for continued polymerization, thereby incorporating the second monomer as a distinct block into the linear polymer. The block polymer so grown is living until terminated.
Butadiene and styrene are often used to prepare such polymers. The most common of these are styrene and butadiene diblock copolymers and triblock copolymers having a butadiene based midblock with styrene endblocks. In some instances, coupling agents can also be used to couple still living polymers to prepare higher molecular weight polymers. In the production of the most common triblock copolymers, after the butadiene midblock is prepared, additional styrene is then added to the molecule to form a styrene endblock. These polymers are often referred to as SBS copolymers. Such polymers are often sold with retained unsaturation, but hydrogenated forms wherein some or all of the unsaturation has been eliminated are also available.
Microstructure control of conjugated diene polymers or conjugated diene copolymer blocks within block copolymers can be important because a controlled degree of branching in the polymer can be desirable. In the case of butadiene, if the polybutadiene or polybutadiene block is all straight chain, such as in 1,4-polybutadiene, then when the polymer is hydrogenated it will have a polyethylene-like structure and have the corresponding crystallinity associated with such a structure. If the polybutadiene or polybutadiene block is branched, such as in 1,2-polybutadiene, the crystallinity will be lessened or eliminated, which can introduce thermoplastic and elastomeric properties into the polymer.
Microstructure control may be used to prepare a block copolymer based upon only a single monomer. The blocks in such a copolymer differ only in the nature of the addition of the monomer species. This type of block copolymer has been prepared from diene monomers using anionic polymerization techniques. If the diene monomer is butadiene, the first block might be prepared without the addition of a microstructure control agent which would afford a segment which is predominately the result of 1,4-addition of butadiene. A microstructure control agent could be added to the living polymer at that point and additional butadiene added. Polymerization of a second block of butadiene would ensue which would be higher in 1,2-addition of butadiene. The 1,2-addition of butadiene is often referred to as vinyl addition as the product introduces a vinyl group pendant to the polymer backbone. A two-block copolymer prepared in this way would have blocks derived from butadiene that differ only in vinyl content.
The glass transition temperature (Tg) of conjugated diene polymers is also affected by microstructure control. The more 1,4-polybutadiene structure present, the lower the resulting Tg of the butadiene segments and the lower the service temperature of the polymer. Microstructure can also affect melt compatibility with polyolefins such as polypropylene and polyethylene.
Particularly for SBS thermoplastics, it is desirable that the microstructure of the block copolymer includes at least some degree of branching or vinyl content in the polybutadiene midblocks. The resulting block copolymers can then have the desired thermoplastic and elastomeric properties, such as lower glass transition temperature, usually designated using the symbol Tg, and hardness. This is known in the art and it is disclosed in references such as U.S. Pat. No. 5,795,944 to Graafland, et al. Therein, it is disclosed to use a microstructure control agent in two or more doses to closely control the vinyl content of a polymer, in some cases even varying the vinyl content within different regions within the midblock. Block copolymers having specific microstructures can also be prepared by coupling as is shown in EP 0 387 947 B1 to Van der Huizen, et al.
It would be desirable in the art of preparing conjugated diene polymers and conjugated diene copolymer blocks to prepare the polymers or copolymer blocks with both higher and lower amounts of branching as compared to conventional microstructure control technology.

Conjugated diene polymers and copolymer blocks and process for preparing same


A gravel packing apparatus (310) has an outer tubular (312) having a plurality of openings (314) therethrough and a sand control screen assembly (318) disposed within the outer tubular (312). The sand control screen assembly (318) prevents the flow of particulate material of a predetermined size therethrough but allows the flow of production fluids therethrough. Sensors (354–360) are operably coupled to the outer tubular (312), the sand control screen assembly (318) or both. An instrument line (348) disposed between the outer tubular (312) and the sand control screen assembly (318) is operably associated with the sensors (354–360) such that power, signals and data may be transmitted between the sensors (354–360) and the surface or other downhole systems.

Without limiting the scope of the present invention, its background is described with reference to the production of hydrocarbons through a wellbore traversing an unconsolidated or loosely consolidated formation, as an example.
It is well known in the subterranean well drilling and completion art that particulate materials such as sand may be produced during the production of hydrocarbons from a well traversing an unconsolidated or loosely consolidated subterranean formation. Numerous problems may occur as a result of the production of such particulate. For example, the particulate causes abrasive wear to components within the well, such as the tubing, pumps and valves. In addition, the particulate may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate matter is produced to the surface, it must be removed from the hydrocarbon fluids by processing equipment at the surface.
One method for preventing the production of such particulate material to the surface is gravel packing the well adjacent the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a particulate material known as gravel is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
The liquid carrier either flows into the formation or returns to the surface by flowing through the sand control screen or both. In either case, the gravel is deposited around the sand control screen to form a gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of particulate materials from the formation.
It has been found, however, that a complete gravel pack of the desired production interval is difficult to achieve particularly in long or inclined/horizontal production intervals. These incomplete packs are commonly a result of the liquid carrier entering a permeable portion of the production interval causing the gravel to form a sand bridge in the annulus. Thereafter, the sand bridge prevents the slurry from flowing to the remainder of the annulus which, in turn, prevents the placement of sufficient gravel in the remainder of the annulus.
Therefore, a need has arisen for an apparatus and method for gravel packing a production interval traversed by a wellbore that is capable of monitoring the gravel packing operation. More specifically, a need has arisen for such an apparatus that is capable of providing real time data on the effectiveness of the gravel placement operation. In addition, a need has arisen for such an apparatus that is capable of discovering voids during the placement of the gravel thereby allowing the operator to correct this undesirable situation.

Gravel packing apparatus having an integrated sensor and method for use of same