The invention discloses an expandable copolymer resin used for manufacturing a lost foam casting model and a preparation method thereof, wherein the molecular weight of the expandable copolymer resin is 150000-300000, and the expandable copolymer resin comprises mixed monomers, deionized water, a cellulose ether dispersant, sodium salt, an initiator, a foaming agent and a molecular weight regulator; the mixed monomers comprise MMA and ST, wherein MMA accounts for 70-95% wt of the mixed monomers, and ST accounts for 5-30% wt of the mixed monomers. The model formed by the expandable copolymer resin has the advantage of reducing or eliminating carbon defects of castings when casting cast iron and cast steel.

Lost foam casting is a new casting process developed in the 1980s. The key technology of lost foam casting is to replace traditional wood model, wax model, or the like with foam plastic models, which renders the following advantages:
1. the size precision and the surface smoothness of the casting are higher than those of a sand casting;
2. less organic waste gas is discharged, and clean production is readily realized; and
3. the casting has a great degree of flexibility in structural design, and a structure to be assembled by machining a plurality of parts can be integrally cast by bonding after the die is manufactured in sections, so that the cost required by assembly and machining is greatly saved.
In order to achieve the above-mentioned advantages of a lost foam casting, the key point lies in the high quality of the modeling material. The traditionally used modeling material is expandable polystyrene, i.e., EPS.
Chinese Patent Publication No. CN1589185A, published on Mar. 2, 2005, discloses a lost foam casting method, which is characterized in that melt is injected into a sand model formed by embedding a synthetic resin foam model in modeling sand, and a casting product is cast while the model disappears by using the melt, gas generated by the disappearance of the model is discharged to the outside of the sand model by means of a discharge passage provided with a discharge gas inhibiting mechanism; the ventilation of the discharge passage is controlled according to the material and shape of the model, the type and temperature of the melt, and the synthetic resin foam is polystyrene, polymethyl methacrylate or a copolymer thereof.
However, the synthetic resin foam used in the prior art is polystyrene, polymethyl methacrylate or a copolymer thereof, and the main component of EPS is a benzene ring compound, which can be hardly thermally decomposed at a high temperature, but can be easily decomposed at the high temperature of casting molten iron to form a tar-like substance that adheres to the inner surface of the outer coating of the model. Consequently, a large amount of carbon slag is formed at a high temperature of 900° C. or above, which adheres to the surfaces of cast iron and steel, leading to the phenomenon of carbon defect in the casting, This further results in low qualified rate and poor quality of the finally obtained casting when casting cast iron and cast steel.

Expandable copolymer resin used for manufacturing lost foam casting model and preparation method thereof

HANGZHOU YUHANG YATAI CHEMICAL INDUSTRIES CO., LTD.


A single, double and extended precision shifter circuit for a hardware floating point divide circuit is disclosed. The divide circuit implements the divide function by receiving two floating point numbers (X and Y) from a main processor, generating the quotient of X/Y using radix 4 SRT nonrestoring division steps, and then delivering the quotient to the main processor. The divide circuit is comprised of a control circuit, a quotient prediction circuit, a partial remainder generator circuit and a quotient generator circuit. The precision shifter circuit operates during the nonrestoring division steps to steer the next negative and positive quotient values generated by the quotient prediction circuit into the proper place within respective negative and positive quotient registers of the quotient generation circuit. The steering is performed according to the precision specified for the divide operation.

1. Field of the Invention
This invention relates to the field of digital information processing systems. More particularly, this invention relates to microarchitecture hardware implementation in connection with certain mathematical algorithms for improving the computing capacity of such systems.
2. Art Background
A common method of improving speed of a computer system is to employ a math processor, separate from the main processor, for performing mathematical calculations. The combination main processor and math processor provides greatly increased speed of system operation, since math processors are optimized for performing mathematical calculations, and since the burden of performing specialized calculations is lifted from the main processor. Tasks typically delegated to a math processor include addition, subtraction, multiplication and division. To save critical space within the math processor, many component circuits of the math processor are designed to perform several functions. For example, it is quite common for the same component circuits to be used when performing multiplication, division and square root functions.
Each new generation of computer system design requires increasingly sophisticated computers to perform calculations faster than previous generations of computers and to perform the calculations with increasingly greater precision. Previous math processors used single digit, or 1 bit of quotient per clock (radix 2), nonrestoring division steps to generate the division function. However, this method is time-consuming since the number of division steps required increases approximately proportionally to the precision required for the division operation. The large number of steps required by single digit nonrestoring division, particularly for IEEE floating point extended precision, greatly slows the division function.
Furthermore, in slower divider circuits, or in divider circuits which do not have a wide data path width required by extended precision, when a lesser precision result is required than the maximum precision of the divider, it is common to permit the significant bits of the quotient to accumulate in a format such that the most significant bits (MSBs) of the quotient occupy the least significant bits (LSBs) which are output from the divider. A steering multiplexer (MUX) is then placed between the divider circuit and the result bus and is used to steer the significant bits to their proper position on the bus (i.e. so that the significant bits of the quotient occupy the most significant bits of the result bus regardless of the precision specified for the division operation). Generally, no shifting is required by the steering MUX for the maximum precision case, because a maximum result has the same number of significant bits as the width of the result bus.
However, in the worst case, (i.e. a single precision divide with an extended precision result bus), the significant bits of the resulting quotient would have to be shifted to a higher order by 40 bit positions and the least significant 40 bits filled with zeros. The use of a steering MUX following the divider circuit is not practical in a fast, extended precision processor for several reasons. First, the paths necessary to perform a 40 bit position shift for a single precision result, and a 12 bit position shift for an extended precision result, would occupy an unacceptably large amount of critical area upon the circuit board. Also, the length and number of the traces to perform the shifts would place a large capacitive load upon the final stage of the divider circuit.
Furthermore, if a steering MUX were used between the final stage of the divider circuit and the result bus, additional logic would be required there to implement the MUX. The increased logic would increase the load which the final stage must drive, thereby requiring that a larger driver be used in the final stage. A larger driver in the final stage would increase the area of the final stage, as well as its power consumption. Additionally, the increased amount of logic in the steering MUX would occupy additional precious board area and would introduce additional propagation delay. The latter is significant since the steering MUX would lie upon the critical path of the divider if it were coupled between the output of the final stage and the result bus.
As will be disclosed, the present invention provides a method and apparatus for improving the speed of the division function by implementing non critical path significant bit position correction steering logic thereby decreasing the time spent by the division circuitry to generate a quotient with a selected single, double or extended precision.

Shifter circuit for multiple precision division


An active device array substrate includes a substrate, a first pixel electrode, and a first raised pattern. The first pixel electrode is disposed on or above the substrate, and the first pixel electrode includes a first truck electrode, a second truck electrode, and a plurality of first branch electrodes. The first truck electrode and the second truck electrode intersect to form a first node at the intersection of the first truck electrode and the second truck electrode. The first branch electrodes are connected to the first truck electrode and the second truck electrode to form a plurality of first domains, wherein the first branch electrodes are asymmetrical with respect to the second truck electrode. The first raised pattern is disposed at least between the first node and the substrate to form a first raised structure at least at the first node.

1. Field of Technology
The present disclosure relates to an active device array substrate.
2. Description of Related Art
In multi-domain vertical alignment technology, liquid crystal molecules are aligned in various directions to reach multi-domain liquid crystal by the designs of pixel structures and electric field distributions, which further enhances the performance of wide viewing angle of optical devices. However, in some multi-domain vertical alignment mode displays, the nodes of liquid crystal molecules are difficult to fixed at the intersections of truck electrodes exactly, which causes the reorientation of the liquid crystal molecule unstable. The instability of the reorientation of liquid crystal affects the image quality seriously.


Methods and systems for measuring atmospheric water content, are provided. The method includes measuring a first air temperature and a first air pressure at a first location in a compressor, measuring a second air temperature and a second air pressure at a second location in the compressor, computing a ratio of specific heats from the first and second air temperatures and the first and second air pressures, and determining an atmospheric water content from the ratio of specific heats.

This invention relates generally to methods and systems for measuring atmospheric conditions and more particularly, to methods and systems for collecting atmospheric weather data using an aircraft.
An important obstacle to improved forecasting is lack of data about water content in the troposphere. Water content of an air mass can change rapidly during storms, over moist soil, or over bodies of water such as oceans. An inability to track changes in water content in these and other areas contributes to inaccurate weather forecasts.
Existing methods for detecting and quantifying water vapor are inadequate because they can only be implemented on a local scale over land thereby leaving vast gaps in global meteorological continuity. The largest gaps occur over oceans where most atmospheric conditions originate. Although the existing atmospheric sensing systems listed below exhibit high resolution capabilities on a local scale, it is not practical to deploy such systems on a global scale because they are expensive to implement or maintain on a global scale and they lack adequate temporal and/or spatial resolution for realistic use on a global scale.
Currently, a primary source of water vapor measurements are ground-based humidity sensors and balloon-borne sensors called "radiosondes." Radiosonde data have high quality, but have relatively poor spatial and temporal resolution. The radiosonde, an expendable balloon-borne instrument package that relays temperature, humidity, and pressure data to a ground receiver by radio signals, is the traditional cornerstone of the worldwide operational weather analysis and prediction system through deployments twice daily at several hundred sites around the world. However, the twice daily radiosonde deployments are primarily over land and are sparsely distributed due to cost considerations. No above-ground measurements are available during intervals between launches or at locations far from radiosonde launch points. For these reasons, radiosonde data is too costly and localized to support high resolution global meteorology.
A limited number of commercial air carriers presently provide real-time wind, pressure, temperature, and humidity readings around the world as part of a system called Aeronautical Communications Addressing and Reporting System (ACARS). Although the ACARS system provides about 10,000 readings per day world wide at a cost about 100 times less than the recurring cost of radiosondes, the vast majority of ACARS readings are around airports and along common flight paths at established cruise flight levels which limits the spatial scope of this otherwise valuable data.
Earth-based Differential Absorption Lidar (DIAL) and Raman Lidar systems are used to provide wind and water vapor profiles in remote areas. However, such systems are not economic to install and maintain, they do not penetrate cloud cover, and the lasers used are highly energized and are therefore not eye-safe.
Water vapor radiometers are instruments that measure microwave energy emitted by the atmosphere to estimate zenithal integrated water vapor. Integrated water vapor is a measure of the depth of liquid water that would result if a column of water vapor were condensed into liquid water. Zenithal integrated water vapor (IWV), also known as Precipitable Water Vapor (PWV), is the integrated water vapor in a vertical column directly overhead an Earth-based measuring device. Earth-based upward-looking water vapor radiometers estimate PWV by measuring radiative brightness temperatures against the cold background of space. However, upward-looking water vapor radiometers must be "tuned" to local conditions using independently obtained PWV data, and although they generally exhibit good temporal resolution in relatively clear atmospheric conditions, they provide only localized PWV over land. Further, unless properly equipped, upward-looking radiometers are virtually useless in rain. Alternatively, satellite-based, downward-looking radiometers perform well over water and consistent temperature land masses by viewing microwave emissions from the atmosphere and underlying Earth's surface. Although downward-looking radiometers generally exhibit good spatial resolution they exhibit poor temporal resolution and perform poorly over most land masses. In either case, water vapor radiometers as a whole are not practical for global scale meteorology due to their cost, limited view, and performance characteristics.
Fourier Transform Infrared Radiometer (FTIR) systems can provide high resolution satellite-based and Earth-based temperature and water vapor profiles by using a recursive solution of the radiative transfer equation to provide a vertical profile from the ground up. Although this method can provide vertical resolution of several hundred meters to a kilometer in the lower troposphere, the system exhibits poor performance in the presence of cloud cover and infrared active gases such as tropospheric ozone.
Unmanned Air Vehicles (UAV's) provide high resolution data in regions inaccessible to other systems discussed above. However, unmanned aircraft are too costly for continuous global sensing, they lack adequate spatial and temporal resolution, and are typically only justified in specialized research applications.
Additional water content measurements are available from satellites and from a few specially-equipped airliners operated under a NASA program called Tropospheric Airborne Meteorological Data Reporting (TAMDAR). Satellite data are unreliable because it is difficult for satellites to correctly resolve the altitude profile of moisture, especially when clouds are present. TAMDAR uses humidity sensors mounted on the outside of small, regional airliners. These sensors continuously measure humidity and temperature as the aircraft ascend and descend through the troposphere. This provides better spatial and temporal resolution than radiosondes. Though this approach has been shown to be technically effective for improved weather forecasts in the northeastern US, the additional weight and drag and the need for FAA certification of each type of sensor package on each type of aircraft makes this solution costly, which has limited the expansion of existing systems to other regions.


A multiplexed neural core circuit according to one embodiment comprises, for an integer multiplexing factor T that is greater than zero, T sets of electronic neurons, T sets of electronic axons, where each set of the T sets of electronic axons corresponds to one of the T sets of electronic neurons, and a synaptic interconnection network comprising a plurality of electronic synapses that each interconnect a single electronic axon to a single electronic neuron, where the interconnection network interconnects each set of the T sets of electronic axons to its corresponding set of electronic neurons.

The present invention relates to neurosynaptic networks, and more specifically, this invention relates to time-division multiplexed neurosynaptic cores.
Core-based neurosynaptic systems are built of multiple neurosynaptic cores, where the neurosynaptic cores are configured and connected to form a neurosynaptic network. A single neurosynaptic chip contains a fixed number of neurosynaptic cores. For example, a single neurosynaptic chip may contain hundreds or thousands of cores. Chips of various sizes, i.e., number of cores, can be manufactured. To implement a neurosynaptic system, one or more chips are needed. Because manufacturing neurosynaptic chips is expensive, it is desirable to minimize the number of chips used by a given system.
In some environments, a large number of neurosynaptic cores may be programmed to perform the same function. Still yet, a given configuration of neurosynaptic cores may be tiled across a chip multiple times. In other words, a layout or connectivity between cores may be repeated across a chip or chips multiple times, such that a first group of cores is performing the same task(s) as a second group of cores.

Energy-efficient time-multiplexed neurosynaptic core for implementing neural networks spanning power- and area-efficiency

International Business Machines Corporation


A sheet film forming roll includes a center rotary shaft. Fixed end plates are disposed in two locations which are away from each other in an axial direction of the center rotary shaft, respectively. An external cylinder is made of a metal thin film. Two ends of the external cylinder are rotatably supported by the fixed end plates, respectively. Multiple rolling rubber rolls have ends which are rotatably supported by the respective fixed end plates. The rolling rubber rolls are in sliding contact with an outer peripheral surface of the center rotary shaft, and in sliding contact with an inner peripheral surface of the external cylinder. The rolling rubber rolls divide an annular space between the external cylinder and the center rotary shaft into multiple heating medium chambers arranged in a circumferential direction of the sheet film forming roll. A heating medium is configured to be filled in each of the multiple heating medium chambers. At least one heating medium chamber includes a heater which uses electricity as its heat source.

1. Field of the Invention
The present invention relates to a sheet film forming roll, a sheet film casting apparatus, a fine pattern transferring apparatus and a sheet film. The present invention relates particularly to a temperature-controllable sheet film forming roll whose roll surface temperature varies from one place to another in a circumferential direction of the roll.
2. Description of the Related Art
One of such temperature-controllable sheet film forming rolls each whose roll surface temperature varies from one place to another in the roll circumferential direction includes: a fixed internal cylinder; a rotatable external cylinder disposed concentric with the internal cylinder; an annular medium passage formed by an interstice between the outer peripheral surface of the internal cylinder and the inner peripheral surface of the external cylinder; multiple partitioning members extending in the axial direction of the internal cylinder, and thereby partitioning and dividing the annular medium passage into multiple smaller medium passages arranged in the circumferential direction; multiple slit-shaped medium inlet ports drilled in the thickness portion of the internal cylinder at positions different in the circumferential direction of the internal cylinder so as to communicate respectively with the smaller medium passages, the medium inlet ports extending in the axial direction of the internal cylinder; and multiple slit-shaped medium outlet ports drilled in the thickness portion of the internal cylinder at positions different in the circumferential direction of the internal cylinder so as to communicate respectively with the smaller medium passages, the medium outlet ports extending in the axial direction of the internal cylinder.
This technology is disclosed in Japanese Patent Application Laid-Open No. 2006-256159 (Patent Document 1).
The sheet film forming roll needs to be made with a thin structure which causes the external cylinder (external barrel) to have a smaller heat capacity for the purpose of making the roll surface temperature of the sheet film forming roll clearly vary among the temperature controlling zones partitioned in the roll circumferential direction while the sheet film forming roll is rolling.
In this respect, the conventional type of sheet film forming roll can be employed in sheet film casting or the like by sheet forming film methods with no large pressing force applied to the external cylinder, including a peening forming method and an air-chamber forming method. However, the conventional type of sheet film forming roll cannot be employed to cast a sheet film using touch rolls that press a resin against the roll surface while casting the resin. Since the external cylinder is made to have a thin structure with a smaller heat capacity, the pressing of the touch rolls deforms the external cylinder, and thus hinders the resin from receiving a sufficient pressing force. As a result, no sheet film is casted correctly.
Furthermore, the conventional type of sheet film forming roll makes it difficult to appropriately set the temperatures for the respective medium passages (heating medium chambers) whose temperatures should be different from one another, because the heating medium leaks from and to the medium passages.

Sheet film forming roll, sheet film casting apparatus, fine pattern transferring apparatus and sheet film


The present invention relates to an optical film including a light-transmitting substrate film such as a polyester-based substrate film and an antiglare layer, and more specifically, to an optical film capable of effectively suppressing the occurrence of interference fringes derived from the substrate film, realizing excellent antiglare properties, and having excellent scratch resistance, and excellent adhesion between the substrate film and the antiglare layer, and the like, and to an image display device including the same.

In an image display device such as an organic light emitting diode (OELD) or a liquid crystal display (LCD), it is required to prevent a decrease in contrast due to a reflection of external light or a reflection of an image, and a deterioration of the visibility. For this purpose, in order to reduce a reflection of an image and a reflection of light by using scattering of light or optical interference, an optical laminated film such as an antireflection film is formed on the surface of the image display device.
For example, in a liquid crystal display or the like, an optical laminated film including an antiglare layer has been generally formed. Such an antiglare layer mainly includes a binder and fine particles contained in the binder, and these fine particles are usually formed so that a part thereof protrudes on the surface of the binder. That is, the antiglare layer allows the fine particles protruding on the surface of the binder to control light scattering/light reflection, thereby suppressing deterioration of the visibility of the image display device.
However, in the case of previously known antiglare layers and optical films, the gloss value of the surface is often high and it is difficult to suppress the reflection of external light. Consequently, it is impossible to sufficiently suppress a decrease in the contrast of the image display device or the like. In addition, in the previous antiglare layers and optical films, as the crosslinking density of the binder and the like are not sufficient, scratch resistance of the surface is often insufficient.
On the other hand, the previously known optical films generally have a shape in which an antiglare layer is formed on a light-transmitting substrate film. As such a light-transmitting substrate film, a cellulose ester-based film typified by triacetyl cellulose (TAC) is most widely used. Such a cellulose ester-based film has advantages in that transparency and optical isotropy are excellent, the in-plane retardation is hardly represented, and thus interference fringes are not generated and the display quality of the display device is not adversely affected.
However, the cellulose ester-based film not only is a material which is disadvantageous in terms of cost, but also has disadvantages that it has a high moisture permeability and poor water resistance. Due to such high moisture permeability and poor water resistance, a considerable amount of water permeation occurs continuously during use, and floating phenomenon may occur, thereby causing light leakage.
Due to the disadvantages of these cellulose ester-based films, attempts have been recently made to replace and apply polyester-based films such as polyethylene terephthalate-based films as a substrate film of the optical film for protecting a polarizer. Such a polyester-based film is inexpensive and has excellent water resistance, and thus there is almost no possibility of causing light leakage phenomenon, it has excellent mechanical properties.
However, such a polyester-based film has a disadvantage in that it contains an aromatic ring having a high refractive index in the structure, and it exhibits an anisotropy due to a difference in elongation in the MD/TD direction or the like in the process of the film formation. As a result, when the above polyester-based film is applied as a substrate film of an optical film, interference fringes due to transmission/reflection of light are occurred, and the visibility of the display device is deteriorated.
In addition, the antiglare layer formed on the light-transmitting substrate film usually includes a (meth)acrylate-based binder, and when the above polyester-based film is applied as a substrate film of an optical film, adhesion between the substrate film and the antiglare layer is often not sufficient.

Optical film and image display device including same


The rotor drive of an aluminum refining system is operated under constant current, rather than at constant rotor speed. As a result, smooth, stable refining operations are conveniently achieved in commercial practice.

1. Field of the Invention
This invention relates to the refining of aluminum. More particularly, it relates to the control of the rotor speed of an aluminum refining system.
2. Description of the Prior Art
Molten aluminum, as derived from most common sources, such as primary metal, scrap and re-melt ingot, usually must be refined, or purified, before being cast into ingots, sheets or bars. This can be accomplished by bubbling an inert sparging gas, e.g., nitrogen or argon, through the aluminum present in molten form in a refining vessel. In some instances, chlorine is also employed. In such refining operations, dissolved hydrogen, non-metallic particles and alkaline and alkaline-earth metals are removed from the molten aluminum. For maximum effectiveness and economical gas usage, the sparging gas is dispersed in the body of molten aluminum in the form of fine bubbles. Such dispersion is advantageously accomplished by the use of a spinning nozzle for the injection of the sparging gas into the molten aluminum.
The refining rate of such a spinning nozzle system can be increased by increasing the flow rate of the sparging gas or gases employed. It is usually necessary, in addition, to increase the nozzle rotating speed to continue the desired formation of small gas bubbles and the dispersing of said bubbles throughout the molten aluminum in the refining zone of the system. Such increase in gas flow and nozzle rotating speed is usually accomplished by increased turbulence on the surface of the molten aluminum. The maximum refining rate for a given refining system is limited by the maximum surface turbulence that can be tolerated in said system.
One very effective manner of using small bubbles and dispersing them in a body of molten aluminum is by the use of a spinning nozzle positioned within said body of molten aluminum in the SNIF.TM. systems of Praxair, Inc. as shown in the Pelton patent, U.S. Pat. No. 4,784,374. In the usual operation of such a system, the spinning nozzle rotor is driven at a constant speed. This is accomplished by driving the rotor with an electric motor controlled by a variable speed electric drive. This allows the rotor speed to be set out at an appropriate value for a particular operation being carried out in the refining system. The rotor speed may be set at different values depending on such variations as process gas flow and system size. Once the speed is set at its optimum value, however, it will remain constant during the refining operation. Short time variations in liquid flow into the rotor will result in variations in load on the rotor and on the motor that drives it. These variations are reflected in variations in motor current as a result of the normal functioning of the control unit used to maintain constant speed. However, average motor current varies smoothly and continuously with the set speed as shown in FIG. 1 of the drawings.
In a high refining capacity system, there is a discontinuity in the speed vs. current relationship as shown in FIG. 2 of the drawings. If the sparging gas flow is commenced and then the drive motor is turned on with the speed set at 450 rpm, the average current will be shown at point A. As the speed is increased by adjusting the speed control dial on the motor drive unit, the average current will increase slowly and continuously as shown by the lower line in FIG. 2, through points E and F until point B at 550 rpm is reached. A further increase in speed setting to 575 rpm will cause the current to increase rapidly to point C on the upper line of FIG. 2. If the speed setting is now decreased, the current will decrease slowly and continuously along values shown on the upper line until point D is reached at 500 rpm. If the speed is lowered to 475 rpm, the current rapidly drops to point E on the lower line.
When operating at any speed-current relations shown on the bottom line of FIG. 2, the bubble pattern obtained in the refining vessel is as shown in FIG. 3. Thus, the bubbles go rapidly upward and produce a rough surface around the spinning nozzle. This is undesirable, both from a refining rate standpoint and with respect to surface roughness.
When operating at any speed-current relation shown on the upper line of FIG. 2, the bubble pattern is as shown in FIG. 4. In this case, the bubbles flow in an outward and somewhat downward direction in the refining vessel, resulting in much better bubble distribution within the refining vessel. This produces a smoother molten metal surface and a higher refining rate compared with operation at point B on the lower line of FIG. 2. However, the surface is not as desirably smooth as it can be. The smoothest surface is obtained by reducing the rotor speed until point D is reached.
After having determined where optimal point D is by the foregoing procedure, it is possible to reach said point D by another route. This is to start rotation at the point D valve, with no gas flow, or with relatively low gas flow, and then to turn on full gas flow after a few seconds of said operation.
By whatever route point D is reached, it has not been possible to operate at this optimal point for very long with speed control in conventional aluminum refining practices. There will occasionally be swings in molten aluminum flow pattern in the refining chamber. As a result, the drive motor current will be found to drop suddenly to point F on the lower line of FIG. 2, with its undesirable bubble pattern. In this circumstance, the desirable operating point D may be re-established only by going through one of the two routes described above.
In practical commercial operations in which the refining system is operated with conventional speed control alone, it is necessary to operate at a higher speed and current than at point D, as, for instance, at point C on FIG. 2. This will provide stable and repeatable operation with the desired bubble pattern, but the surface of the molten aluminum will be much rougher than at the desired point D.
There is a need in the art, therefore, for improvement in the operation of systems for the refining of molten aluminum. Specifically, there is a need for improved means for controlling the rotor speed so as to reach and maintain the optimal point of speed-current during continued refining operations.
It is an object of the invention, therefore, to provide an improved rotor speed control for an aluminum refining system.
It is another object to provide a rotor speed control enabling optimal conditions to be achieved and maintained during refining operations.
With these and other objects in mind, the invention is hereinafter described in detail, the novel features thereof being particularly pointed out in the appended claims.

Rotor speed control for an aluminum refining system


A wireless sensor network for musical instruments is provided that will allow a musician to communicate natural performance gestures (orientation, pressure, tilt, etc) to a computer. User interfaces and computing modules are also provided that enable a user to utilize the data communicated by the wireless sensor network to supplement and/or augment the artistic expression.

Throughout history, musical instruments have followed a process of co-evolution with developing technology to become what we know them as today. From the beginnings with sticks and bone, to cat-gut strings, to brass, to the piano-forte, and then to electronic synthesizers, musical instruments reflect the major technological breakthroughs of each time period.
As music technology continues to rapidly advance, the question of how acoustic instruments and traditional performance practice can be interfaced to current technological advancements must be continually re-evaluated and explored.
In the present age, the pervasiveness of computers, including mobile applications, is affecting music and other media technology. Having become invisibly interwoven into the fabric of our daily routine, developments in interactive computing have only begun to marginally affect conventional music instrument design and performance practice.
Attaching sensors to acoustic instruments to allow them to interact with sound using computers began with the hyperinstruments project at MIT. The hyperinstrument project was started in 1986 with the goal of designing expanded musical instruments, using technology to give extra power and finesse to virtuosic performers. The hyperinstruments were designed to augment guitars and keyboards, percussion and strings, and even conducting. A famous hyperinstrument application is the hypercello played by Yo-Yo Ma in the early 1990s. The hypercello allows the cellist to control an extensive array of sounds through performance nuance. The hypercello was an acoustic cello and a computer controlling synthesized sounds that accompanied the playing of the acoustic cello. Wrist measurements, bow pressure and position sensors, and left hand fingering position indicators enable the computer to measure, evaluate, and respond to a variety of aspects of the cellist's performance. The computer then controlled aspects of the sound of the cellist's performance. The sound of the performance was able to be affected by, in some cases, triggering and modifying the synthesized sounds that accompanied the acoustic cello.
Current trends in the Performance Arts, academic Computer Music conferences at national and international levels, and the gaming industry reveal a need for musicians to communicate gestural performance data of their musical instrument to a computer or other processing system. However, current literature in the field posits that the existing MIDI protocol, which utilizes the pitch-velocity-duration paradigm, has proven to be insufficient in representing the sensitive nuances that occur during live music performance.

Modular wireless sensor network for musical instruments and user interfaces for use therewith

University of Florida Research Foundation, Incorporated


Some microprocessors check branch prediction information in a branch history table and/or a branch target buffer. To check for branch prediction information, a microprocessor can identify which instructions are control flow instructions and which instructions are non control flow instructions. To reduce power consumption in the branch history table and/or branch target buffer, the branch history table and/or branch target buffer can check for branch prediction information corresponding to the control flow instructions and not the non control flow instructions.

1. Field of the Invention
The techniques described herein generally relate to microprocessors, and in particular to reducing power consumption for branch prediction.
2. Discussion of Related Art
Microprocessors are electronic devices that can perform a variety of computing operations in response to instructions that implement a computer program. A common technique for implementing computer programs is to send multiple instructions to the execution unit of the microprocessor in a predetermined sequence, and these instructions are then executed in sequential order. In some circumstances, program execution jumps out of order to execute an instruction which is not the next instruction in the sequence. One example of an instruction that causes the execution to jump out of sequence is a branch instruction. When a branch instruction is executed, the microprocessor can jump to the target instruction identified by the branch instruction, and the microprocessor executes the target instruction next, rather than the next sequential instruction.
By way of illustration, FIG. 1 shows one example of a program execution sequence in which five sequential instructions 1-5 are executed in a sequential manner, with instruction 1 being executed first, instruction 2 being executed second, etc. In this example, instruction 5 is a branch instruction that specifies instruction 2 as its target instruction. Upon executing branch instruction 5, the microprocessor jumps out of the sequential order of instructions to execute instruction 2 next in the order of program execution, rather than the next sequential instruction 6.
Microprocessors often process instructions using several stages, which can include an instruction fetch stage in which the instructions are fetched from an instruction cache, an instruction decode stage in which the fetched instructions are decoded, and an instruction execution stage in which the instruction is executed. To improve the speed at which multiple instructions are processed through the various stages, some microprocessors use a technique known as pipelining. Pipelining is analogous to an assembly line, in the sense that multiple stages of the pipeline concurrently perform different parts of the process on several different instructions. In one example of a pipelining technique, the first instruction 1 is processed by the first stage of the pipeline in a first computing cycle. In the second cycle, the first instruction 1 goes on to the second stage of the pipeline and the second instruction 2 begins the first stage of the pipeline. In the third cycle, the first instruction 1 proceeds to the third stage of the pipeline, the second instruction 2 proceeds to the second stage of the pipeline, and the third instruction 3 begins the first stage of the pipeline, etc. Pipelining can enable multiple instructions to be executed more quickly than would be the case if only one instruction were processed at a time by the microprocessor. For example, pipelining techniques may allow the processing of a different instruction to be completed in each cycle.
Branch instructions can reduce the efficiency of pipelining techniques. When a branch instruction is executed, the microprocessor may attempt to jump out of the sequential order to execute a target instruction that is not already in the pipeline. To jump to the target instruction, the microprocessor may discard the instructions that are already in the pipeline and re-start the pipeline beginning at the target instruction. As a consequence, a delay can occur while the target instruction is fetched and processed by the initial stages of the pipeline, causing an overall reduction in the speed at which instructions are processed through the pipeline.
Branch prediction is a technique that has been used to improve the speed of pipelined microprocessors that execute branch instructions. Branch prediction can increase the speed of pipelined microprocessors by enabling the microprocessor to fetch the instruction that is likely to be executed after a branch instruction, prior to executing the branch instruction. Branch prediction may involve predicting whether or not a conditional branch is taken, and/or predicting the branch target, which is the target instruction of the branch instruction. For example, when the microprocessor determines that a conditional branch is likely to be taken, the predicted target instruction may be fetched into the pipeline in advance of executing the branch instruction to prepare the pipeline for the branch operation.
A branch history table is a branch prediction unit that can store historical information about whether previous branches were taken, and this historical information can be used to predict whether future branches will be taken. A branch target buffer is a branch prediction unit that can predict the target of a branch instruction. Some microprocessors use both a branch history table and a branch target buffer to perform branch prediction.

Reducing branch checking for non control flow instructions

STMicroelectronics (Beijing) R&D Co., Ltd.


A device for preventing a vehicle from speeding, which device comprises a switching device, a speedometer present in the vehicle, which is connected to said switching device and which measures the speed of the vehicle, as well as a transmitter connected thereto, wherein the switching device is so arranged that the transmitter will only transmit a signal mainly if and as long as the speed measured by the speedometer is higher than a predetermined limiting value.

The invention relates to a device for preventing a vehicle from speeding.
Speeding checks are currently being carried out to an increasing extent, at least in the Netherlands, and as a consequence an increasing number of increasingly heavy fines are being imposed. Consequently there is a need among car owners and drivers for a device by means of which the risk of receiving such fines can be reduced in an efficient and simple manner.

Device and method for preventing speeding


A thermal print head in a thermal printer for printing a digital image, the digital image being composed of lines of multi-bit pixels, the print head having a plurality of thermal resistors, adapted to be simultaneously addressed in parallel by a corresponding plurality of shift register elements, the print head being pulsed a plurality of times to print one line of the image. The print head is driven by providing a table of additive complement values, one additive complement value for each of the possible values of a multi-bit pixel, successively adding each of the complement values to each of the pixel values in a line to create a succession of sums, each sum having an overflow bit, and applying the overflow bits to the shift register elements to drive the print head.

In a thermal printer for displaying a digital image, a thermal print head having a plurality of heaters is activated to transfer dye from a dye carrier medium to an image receiver such as paper. To achieve a continuous tone, the heaters in the thermal print head are modulated to transfer desired amounts of dye for each pixel in the image. The digital image is typically stored as a number of lines of multi-bit pixels, where the value of each pixel represents the gradation value of the pixel. The task of modulating the print head involves converting the lines of multi-bit pixel values into a number of lines of single bit serial data which are sent to a shift register in the print head as shown in FIG. 3.
A typical serial print head as illustrated in FIG. 3 has a number of heating resistors 50 arranged in a linear array. The head also has a solid state serial input shift register 52. The print head shown (as an example) has 512 resistors, and a single serial shift register that has 512 elements. Each shift register element acts as a digital switch, a 0 bit in the element will not close the switch, a 1 bit will. When the digital switch is closed, current flows from the DC head voltage supply to the DC head ground when a printing pulse is applied. A resistor that is energized will heat up, and cause thermal dye to be deposited on the print.
To energize the print head, a stream of 512 modulation bits must be clocked into the shift register 52. One bit must be put into each shift register element regardless whether that resistor will be turned on or not. Every time the print head is to be energized, a stream of 512 modulation bits must be clocked into the shift register.
Known modulation methods include "Modulation by Comparison" and "Decrement Until Zero", which will be described below.
Modulation by Comparison
One known method of producing serial modulation bits involves repeatedly comparing a pixel to an incrementally changing threshold value. This method has for example been discussed in U.S. Pat. No. 5,321,427 issued Jun. 14, 1994 to Agar et al. The result of that comparison is used to produce an "on" or "off" modulation bit, normally represented by a one or a zero, respectively. In the example shown in Table I below, a 3-bit pixel with a gradation value of 5 is successively compared to the threshold values of 1 through 7, to produce 7 modulation bits (note that a 3-bit pixel can have any one of 23=8 values between 0 and 7). If the pixel value is greater than or equal to the threshold, then the modulation bit is a "1", otherwise the modulation bit is a "0". The multi-bit pixel value of 5 produces five "1" bits and two "0" bits in this example.
TABLE IModulation By ComparisonPixel Value5555555Threshold Value1234567Modulation Bit1111100Decrement Until Zero
Another method of producing a stream of serial modulation bits from multi-bit pixel values is to successively test each pixel value in a line to determine if it is non-zero. If a pixel's value is non-zero, its value is decremented by one and a "1" modulation bit is produced. The process is then repeated with the decremented pixel values. When a decremented pixel value reaches zero, it is no longer decremented, and the modulation bit produced is a "0". As shown in Table II below, a pixel value of 5 is first determined to be non-zero, it is then decremented to 4, and a "1" modulation bit is produced. This is repeated 4 more times, until the pixel value has been decremented to 0. For the last 2 bits in the example, the pixel value is already 0, so "0" modulation bits are produced, and the pixel value is no longer decremented. The multi-bit pixel value of 5 produces five "1" bits, and two "0" bits.
TABLE IIModulation by Decrement Until ZeroPixel Value (5)5432100Modulation Bit1111100
Low cost digital signal processors (DSP's) are widely available for controlling consumer equipment. DSP's are easily custom programmable to perform operations such as print head modulation. Unfortunately, the Decrement until Zero and Comparison modulation methods both involve conditional operations which are very inefficient when implemented in software, thereby hindering their use with DSP's. A compare operation must always be followed by a conditional operation based on the result of the comparison. A conditional operation typically requires multiple processor cycles to execute, which is inefficient and wastes processor cycles.
There is a need therefore for an improved modulation method for thermal printers that can be more efficiently implemented in software for use in a programmable DSP.

Thermal print head modulation using additive complements


An exemplary packet processing apparatus where a large number of comparisons can be made concurrently in bit-parallel fashion by partitioning the comparison functionality to two optoelectronic integrated circuits, and interconnecting the two circuits using free space optics. Illustratively, different embodiments are used to perform one-to-many or many-to-one comparisons by developing multiple copies of one value for concurrent comparison with many possible values. The invention is more generally applicable to other comparison applications where one-to-many or many-to-one comparisons are made.

The term broadband covers a host of new products, technologies, services, and networks. One way to define broadband networks is to categorize them as those networks that support services requiring bit rates well above one megabits per second. Business and residential subscribers will be connected to broadband networks via a common access, operating at 150 megabits per second or above, that can handle a range of different broadband service types. ATM (asynchronous transfer mode) has been chosen as the communication principle on which broadband networks will be based. A future broadband ISDN (integrated services digital network) will offer the flexibility needed to handle diverse services ranging from basic telephone service to high speed data transfer, videotelephony, and high quality television distribution. The key to this flexibility is ATM which carries digital information in special cells. This allows the network to be used efficiently by applications and services with widely differing bandwidth requirements and call characteristics.
ATM cells have a five-byte header and a 48-byte payload. The header includes the routing information for the packet. It is important to compare this routing information to many possible values very rapidly. For example, if the bit rate is 155 megabits per second, an eight-byte header corresponds to approximately 0.25 microseconds. It is desirable to make the routing decision in this very short time period. What is needed is an apparatus capable of making very fast comparisons.

Comparison apparatus with freespace optical interconnections between optoelectronic integrated circuits


A process suitable for operation at a mine site for recovering a hydrocarbon from a hydrocarbon bearing sand comprising the steps of mixing a chemical additive with a chemical composition and with a hydrocarbon bearing sand containing hydrocarbon and residual solids including clay, at a temperature to form a slurry. The chemical composition comprises an aqueous phase and a minor amount of a chemical agent selected from the group consisting of at least one ethoxylated alkylphenol compound, at least one ethoxylated dialkylphenol compound, MIBC, SC-177, Petronate HL, Calcium Lignosulfonate, NaOH and mixtures thereof. The slurry is conditioned and aerated to produce essentially sludge-free tailings and a mixture of hydrocarbon, aqueous phase and residual solids including clay. The process further comprises the step of separating in a short-residence time apparatus the mixture of the hydrocarbon, the aqueous phase and the residual solids including clay from the essentially sludge-free tailings.

Tar sands, which are also known as oil and bituminous sands, are siliceous materials which are primarily silica (e.g., sand grains) having closely associated therewith an oil film. Tar sands generally comprise from about 5 to 21 percent by weight of an oil film; from about 70 to about 90 percent by weight of mineral solids; and from about 1 to about 10 percent by weight of an aqueous phase (i.e., water). The oil is very viscous, having an API gravity of about 1 to about 10 degrees API gravity, and typically comprises from about 1.0 to about 10.0 percent by weight inorganic elements (e.g., sulfur) and from about 30.0 to about 50.0 percent by weight cyclic hydrocarbons such as aromatics. The term "solids" is used herein to describe material of inorganic origin such as sand, clay and the like, as distinguished from materials of organic origin such as coke. The major portion, by weight, of the mineral solids in tar sands is quartz sand having a particle size greater than about 40 microns and less than about 2000 microns. The remaining mineral solid material found in tar sands has a particle size of less than about 40 microns and has been generally referred to as "fines". Fines comprise clay and silt including some very small particles of sand. Clay is a hydrated aluminum silicate with a generalized formula Al.sub.2 O.sub.3 SiO.sub.2.xH.sub.2 O. More specifically, it has properties of fine, irregularly shaped crystals and depending on the iron oxide content, it has a specific gravity of from about 2.3 to about 2.7. Types of clay are kaolinite, montmorrillonite, illite, bentonite, attapulgite, and halloysite. The fines content will vary from about 5 percent to about 35 percent by weight of the total mineral solid content of tar sands. It is to be understood and is not uncommon for the ingredients of tar sands to vary from the stated proportions and concentrations.
Canada has the potential to be self-sufficient in petroleum and could be in a very enviable position. To attain self sufficiency with her energy requirements increasing and conventional petroleum reserves decreasing annually, development of energy sources, such as the oil or tar sands, becomes essential. Major impediments to current development of conventional oil sands plants are the large capital investment requirement estimated to range from $35,000 to $45,000 per daily barrel of plant capacity and the concomitant operating costs associated with mining, extraction and upgrading of bitumen to saleable synthetic crude or transportation fuels. Equally important in the production of synthetic crude oil from oil sand by conventional first generation extraction technology is the large quantity of waste water and sludge produced which are likely to be unacceptable in future plants. For example, in the first 10 years of operation at a well known facility, the volume of waste water containment which stores process affected water, waste, process chemicals and sludge grew to about 215.times.10.sup.6 m.sup.3 and covers an area of 22 km.sup.2. (see "Development of the Tailings Pond at Syncrude's Oil Sands Plant; 1978-1987, " M. D. MacKinnon, AOSTRA Journal of Research, 5 (1989) pg. 109.) Future liabilities related to environmental issues and specifically waste water containment may also adversely affect future participation by industry.
The largest and most important deposits of tar sands are the Athabasca tar sands, found along the banks of the Athabasca River in the Province of Alberta, Canada. Total recoverable reserves from the Athabasca tar sands, after extraction and processing, have been estimated at more than about 300 billion barrels. Athabasca tar sands comprise sand grains which are each sheathed in a thin layer of aqueous phase (i.e. water). Bitumen is trapped in the void space between the water-wet grains. The composition of Athabasca tar sands may typically comprise from about 5 to about 15 percent by weight bitumen, from about 1.0 to about 10.0 percent by weight water, and from about 80.0 to about 90.0 percent by weight of solids (as defined above). While the present invention will be described with reference to Athabasca tar sands as a feed stock, it is to be understood that the spirit and scope of the present invention includes any hydrocarbon bearing sand as feed stock.
Presently known commercial arrangements include the existing Syncrude and Suncor operations in Alberta, Canada. Both operations employ dry mining of tar sands, which broadly comprises transportation of this material to extraction plants located distally, separation of a large sand fraction from the tar sands, and slurry transportation of the reject sand-clay-silt stream to a distal tailings pond. The Syncrude and Suncor operations broadly involve mining and tar sands transportation, followed by primary separation which incorporates tumblers, thickeners and flotation vessels. The tailings are slurried back to an ever-increasing pond due to the physical and chemical characteristics of the sands and sludge.
Athabasca tar sands are presently and more specifically processed using a method which is commonly referred to as the "hot water" method. In accordance with the "hot water" process for primary extraction of bitumen from tar sands, tar sand is mixed in a conditioning drum or tumbler with hot water and steam. Sodium hydroxide or other reagents are added as required to maintain and control the pH in the range of from about 8.0 to about 8.5. While in the tumbler, the tar sands disintegrates and liberates bitumen, and simultaneously, liberated bitumen is aerated. By "disintegrate" is meant that the bitumen particles and particulate sand are dispersed or separated from each other in a preliminary manner or fashion. Stated alternatively, during slurrying bitumen films are ruptured and a preliminary separation of the sand grains and bitumen droplets takes place. Simultaneously, air bubbles are entrained in the slurry. The tumbler produces a pulp or slurry comprising from about 5.0 to about 15.0 percent by weight bitumen, from about 15.0 to about 30.0 percent by weight water, and from about 60.0 to about 80.0 percent solids (as defined above), at a temperature of 180.degree.-195.degree. F.
The produced conditioned pulp or slurry leaves the tumbler and is then diluted with additional hot water to further disperse the sand and bitumen. This dilution operation is usually carried out at a screen positioned at the outlet from the tumbler. The diluted or flooded slurry typically has a composition comprising 2 to 10 wt. percent bitumen, 40 to 50 wt. percent water, and 45 to 55 wt. percent solids ( as defined above).
The diluted or flooded slurry is subsequently introduced into a separator cell in proximity to its longitudinal point. The separator cell is typically a cylindrical vessel having a conical bottom. The contents of the separator cell are commonly maintained at about 75.degree. to 85.degree. C. In the separator cell the bitumen particles, which have been attached to air bubbles, tend to rise to the surface of the water body and form a coherent mass known as an oily primary froth which for further treatment is recovered in a launder running around the rim of the cell. The major portion of the solids, particularly the coarse sand particles, tend to sink to the bottom of the cell and are withdrawn or drawn off as tailings.
A middlings stream comprising water, fine solids (e.g., clay) and some oil or bitumen, is continuously withdrawn from the separator cell at a point intermediate to the upper and lower ends of the separator cell. This middling stream typically comprises from about 1 to about 4 percent by weight bitumen, from about 10 to about 20 percent by weight mineral solids, and from about 75 to about 90 percent by weigjht aqueous phase or water. This middling stream is treated in a sub-aerated flotation cell to recover the contained bitumen in the form of secondary froth. The secondary froth is badly contaminated with mineral solids and water and may typically comprise 12 to 20 percent by weight solids, 50 to 60 percent by weight aqueous phase (or water) and 25 to 37 percent by weight bitumen. Once the bitumen has been extracted from the tar sand in this fashion, the primary and secondary froths are combined, diluted with a specific gravity-altering diluent (such as naphtha or any other suitable agent) and treated in a centrifuge circuit to separate the solids or residual minerals and water from the bitumen. The specific gravity-altering diluent (i.e., naphtha) may be distilled for further processing. The following patents broadly teach or suggest an apparatus and/or method for removing bitumen from tar sands, with some of the following patents more specifically teaching the caustic "hot water" process: U.S. Pat. No. 3,068,167 to White; U.S. Pat. No. 3,297,568 to McMahon; U.S. Pat. No. 3,392,105 to Poettmann et al; U.S. Pat. No. 3,696,923 to Miller; U.S. Pat. No. 3,864,251 to Cymbalisty; U.S. Pat. No. 3,869,384 to Schutte; U.S. Pat. No. 4,018,664 to Bain et al; U.S. Pat. No. 4,229,281 to Alquist et al; U.S. Pat. No. 4,340,487 to Lynn; U.S. Pat. No. 4,368,111 to Siefkin et al; U.S. Pat. No. 4,392,941 to Roth et al; U.S. Pat. No. 4,514,305 to Filby; U.S. Pat. No. 4,891,131 to Sadeghi et al; U.S. Pat. No. 4,913,805 to Chin; U.S. Pat. No. 4,946,597 to Sury; U.S. Pat. No. 4,968,412 to Guymon; U.S. Pat. No. 5,009,773 to Schramm et al; U.S. Pat. No. 5,019,245 to Ignasiak et al; U.S. Pat. No. 4,036,732 to Irani et al; U.S. Pat. No. 4,071,434 to Gifford; U.S. Pat. No. 4,110,194 to Peterson et al; U.S. Pat. No. 4,347,118 to Funk et al; U.S. Pat. No. 4,383,914 to Kizior; U.S. Pat. No. 4,399,039 to Yong; U.S. Pat. No. 4,424,112 to Rendall; U.S. Pat. No. 4,676,889 to Hsieh et al; U.S. Pat. No. 4,702,487 to Stoian et al; U.S. Pat. No. 4,719,008 to Sparks et al; U.S. Pat. No. 4,776,949 to Leung et al; and U.S. Pat. No. 4,929,341 to Thirumalachar et al. All of these U.S. Patents will be fully incorporated herein by reference thereto as if fully repeated verbatim immediately hereafter.
Conventional extraction processes result in a significant quantity of organic and inorganic sludges remaining with the reject tailings. This strongly bound (toluene insoluble) organic matter modifies the hydrophilic character of certain oil sand solids resulting in serious problems in processing oil or tar sands in conventional hot water extraction processes. ("Properties of Fines Size Fractions in Relation to the Distribution of Humic-Inorganic Matter Complexes in Athabasca Oil Sands," L. S. Kotlyar and B. D. Sparks, AOSTRA Journal of Research, 4 (1988) pg. 277.) These compounds also complicate the operation of the tailings pond by remaining in suspension as "globules." It has been reported that one half of the silt and clay and almost all the bitumen remains in suspension and flows to the center of the pond to form a sludge containing up to 85 to 90% process water.
Speight and Moschopedis presented results of studies addressing clays remaining in pond water in the form of a colloidal dispersion which adversely affects the volume of water available from the pond for recycle. Variation of pH causes a change in the charge on the surfaces of clay particles, thus effecting flocculation. (see "Factors Affecting Bitumen Recovery by the Hot Water Process, " J. G. Speight and S. E. Moschopedis, Alberta Research Council, 1978.) They further conclude that the disposal of tailings from the hot water extraction process represents one of the major problems facing commercial development. While surface active materials present in the bitumen appear to have a beneficial effect on bitumen recovery, their ability to act as clay dispersants has an adverse effect on the settling of the clays in the tailings pond. (see "Surface and Interfacial Phenomena Related to the Hot Water Processing of Athabasca Oil Sands," J. G. Special and S. E. Moschopedis, Alberta Research Council, Information Series 86, 1980.)
Bowman and Co-workers (J. Leja and C. W. Bowman, "Application of Thermodynamics to the Athabasca Tar Sands", Can. J. Chem. Eng., A6 (1968) pg. 479) established that the surface active agents in the process are primarily water soluble salts of naphthionic acids having carboxylic functional groups. Furthermore, they observed that the surfactants interact with mineral surfaces and play a role in solids flotation.
Sanford and Co-workers concluded that the role of sodium hydroxide in the hot water extraction process is primarily that of a generator of natural surfactants which in some way aid oil separation and/or flotation. A further finding and of equal importance was the relation between the fines level and the caustic needed for oil recovery. Furthermore, very lean grades of oil sands may not be able to supply enough surfactant, adversely affecting bitumen recovery. (L. L. Schramm, R. G. Smith, J. A. Stone AOSTRA Journal of Research, Vol. 1, 1984; page 10)
Schramm and Smith conducted extensive testing to determine the adverse affects that aging of tar sands had on bitumen recovery. They concluded that the aging mechanism is traced to changes in natural surfactant concentrations generated during processing. In essence they found that the aging effect can be traced to reactions that effectively reduce the concentration of natural carboxylate surfactant produced in the hot water separation process. ("Some Observations on the Aging Phenomenon in the Hot Water Processing of Athabasca Oil Sands, Part 2, The Mechanism of Aging," L. L. Schramm and R. G. Smith, AOSTRA Journal of Research, Vol. 3 (1987) pg. 215.)
Kotlyar, Sparks and Kodama concluded that serious problems which occur during bitumen extraction by the hot water process could be due to the fact that the hydrophilic (water loving) character of some of the solids is modified by the presence of tightly bound organic (humic) matter. This material cannot be removed by extraction with good solvents commonly used for bitumen such as toluene or dichloromethane. Most of the humic matter in oil sands is known to be associated with fines i.e., that fraction of oil sands solids with a particle size below 38 microns. (see "Isolation and Characterization of Organic-Rich Solids Present in Athabasca Tailings Pond Sludge", L. S. Kotlyar, B. D. Sparks and H. Kodaman, AOSTRA Journal of Research, Vol. 6 (1990) pg. 41.)
M. D. MacKinnon addresses the development of the tailings pond at the Syncrude plant between 1978 and 1987. He indicates that about 70% of the plant water requirements are reclaimed from the free water zone and that 1 m.sup.3 of water per ton of oil sand is recycled from the pond. An additional requirement of 0.3 m.sup.3 per ton of oil sand is withdrawn from the Athabasca River. Extensive information on the physical and chemical properties of the pond is presented. (M. D. MacKinnon, AOSTRA Journal of Research, Vol. 5 (1989) pg. 109-131.) Other organizations have also investigated alternative technologies for the surface minable resource with a view to reducing the cost of recovering bitumen from oil sands as well as minimizing some of the problems noted.
As specifically stated in U.S. Pat. No. 4,392,941 to Roth et al, the tailings that are collected from recovering bitumen from tar sands, generally will contain solids as well as dissolved chemicals. The tailings are usually collected in a retention pond where additional separation occurs. As is well known, retention ponds involve large space requirements and the construction of expensive enclosure dikes. The tailings can also be considered as processing waste water containing solids which are discharged from the extraction process. The tailings comprise waste water, both the natural occurring water and added water, bitumen and mineral. As stated in U.S. Pat. No. 4,018,664 to Bain et al, because this waste water contains oil emulsions, finely dispersed clay with poor settling characteristics and other contaminants, water pollution considerations prohibit discarding the effluent into rivers, lakes or other natural bodies of water. The disposal of the waste water streams has therefore presented a problem. A portion of the water in the waste water stream can be recycled back into the hot water extraction process as an economic measure to conserve both heat and water. However, experience has shown that the dispersed silt and clay content of the recycled water can reduce primary froth yield by increasing the viscosity of the middlings layer and retarding the upward velocity of oil droplets. When this occurs, the smaller oil droplets, and those that are more heavily laden with mineral matter stay suspended in the water of the separation cell and are removed from the cell with the middlings layer.
The mineral particle size distribution is particularly significant to operation of the hot water process and to sludge accumulation. The terms "sand", "silt" and "clay" are used in this specification as particle size designations. Sand is siliceous material which will not pass through a 325 mesh screen. Silt will pass through a 325 mesh screen but is generally smaller than 45 microns and larger than two microns and can contain siliceous material. Clay is smaller than 2 microns and also can contain siliceous material. The word "fines" as used herein refers to a combination of silt and clay.
As previously indicated and as specifically stated in U.S. Pat. No. 4,392,941 to Roth et al, conditioning tar sands for the recovery of bitumen consists of heating the tar sand/water mixture to process temperature (180.degree.-200.degree. F.), physical mixing of the pulp to uniform composition and consistency, and the consumption (by chemical reaction) of the caustic (i.e., NaOH) or other added reagents. Under these conditions as Roth et al points out in U.S. Pat. No. 4,392,941, bitumen is stripped from the individual sand grains and mixed into pulp in the form of discrete droplets of a particle size on the same order as that of the sand grains. During conditioning, a large fraction of the clay particles becomes well dispersed and mixed throughout the pulp. The conditioning process which prepares bitumen for efficient recovery during the following process steps also prepares the clays to be the most difficult component to deal with in the tailings disposal operation.
As further previously indicated and as specifically stated by Roth et al in U.S. Pat. No. 4,392,941, the other process step, termed "separation", is actually the bitumen recovery step because the separation has already occurred during conditioning. The conditioned tar sand pulp is screened to remove rocks and unconditionable lumps of tar sands and clay. The reject material, termed "screen oversize", is discarded. The screened pulp is further diluted or flooded with water to promote the following two settling processes: globules of bitumen, essentially mineral-free, float upward to form a coherent mass of froth on the surface of the separation units; and, at the same time, mineral particles, particularly the sand size material, settle down and are removed from the bottom of the separation unit as sand tailings. These two settling processes take place through a medium called the middlings. The middlings consists primarily of water, bitumen particles and suspended fines which includes silt and clay.
Roth et al in U.S. Pat. No. 4,392,941 has stated that the particular sizes and densities of the sand and of the bitumen particles are relatively fixed. The parameter which influences the settling processes most is the viscosity of the middlings. Characteristically, as the suspended material content rises above a certain threshold, which varies according to the composition of the suspended fines, viscosity rapidly achieves high values with the effect that the settling processes essentially stop. Little or no bitumen is recovered and all streams exiting the unit have about the same composition as the feed. As the feed suspended fines content increases, more water must be used in the process to maintain middlings viscosity within the operable range.
The third step of the hot water process is scavenging. The feed suspended fine content sets the process water requirement through the need to control middlings viscosity which, as noted before and as indicated by Roth et al in U.S. Pat. No. 4,392,941, is governed by the clay/water ratio. It is usually necessary to withdraw a stream of middlings to maintain the separation unit material balance, and this stream of middlings can be scavenged for recovery of incremental amounts of bitumen. Air flotation is an effective scavenging method for this middlings stream.
As is well known in the art, final extraction or froth clean-up is usually accomplished by centrifugation. Froth from primary extraction is diluted with naphtha, and the diluted froth is then subjected to a two stage centrifugation. This process yields an oil product of essentially pure, but diluted, bitumen. Water and mineral and any unrecovered bitumen removed from the froth constitutes an additional tailing stream which must be disposed.
Tailings are a throwaway material generated or obtained in the course of extracting the valuable material (i.e. bitumen) from the non-valuable material (e.g. sand, sludge, etc.) And in tar sands processing, tailings consist of the whole tar sand plus net additions of process water less only the recovered bitumen product. Roth et al in U.S. Pat. No. 4,392,941 has subdivided tar sand tailings into the following three categories: (1) screen oversize; (2) sand tailings--the fraction that settles rapidly, and (3) middlings--the fraction that settles slowly. Screen oversize is typically collected and handled as a separate stream.
Tailings disposal is the operation required to place the tailings in a final resting place. As previously indicated, because the tailings contain bitumen or oil emulsions which may be defined as finely dispersed clay with poor settling characteristics and other contaminants, water pollution considerations prohibit discarding the tailings into rivers, lakes or other natural bodies. As previously mentioned, currently the tailings are stored in retention ponds (also referred to as evaporation ponds) which involve large space requirements and the construction of expensive enclosure dikes. As further previously mentioned, a portion of the water in the tailings can be recycled back into the water extraction process as an economic measure to conserve water. Roth et al in U.S. Pat. No. 4,392,941 has indicated that the following are two main operating modes for tailings disposal: (1) dike building--hydraulic conveying of tailings followed by mechanical compaction of the sand tailings fraction; and (2) overboarding--hydraulic transport with no mechanical compaction.
For dike building at a well known commercial location, tailings are conveyed hydraulically to the disposal area and discharged onto the top of a sand dike which is constructed to serve as an impoundment for a pool of liquid contained inside. On the dike, sand settles rapidly and a slurry of water, silt, clay and minor amount of bitumen, as well as any chemical used during processing flows into the pond interior. The settled sand is mechanically compacted to build the dike to a higher level. The slurry which drains into the pond interior commences stratification in settling over a time scale of months to years. As a result of this long term settling, Roth et al in U.S. Pat. No. 4,392,941 has stated that three layers form. The top layer, e.g. 5-10 feet of the pool, is a layer of relatively clear water containing minor amounts of solid, e.g. up to 5 wt. percent and any dissolved chemicals. This layer of pond water can be recycled to the water extraction process without interfering with extraction of bitumen from tar sands. As previously indicated, recycling pond water serves to reduce the overall volume increase of water stored in retention pond. Below this clear top water layer is a discontinuity in solid contents. Over a few feet, solids content increases to about 10-15 wt. percent and thereafter, solids contents increase regularly toward the pond bottom. In the deeper parts of the pond, solid contents of over 50 wt. percent have been measured. This second layer is commonly called the sludge layer. In general the sludge layer can be characterized as having more than 10 wt. percent solids (which may also be defined as mineral plus bitumen). More particularly as Roth et al has stated in U.S. Pat. No. 4,392,941, the sludge can be characterized as having 20 wt. percent to 50 wt. percent solids or mineral matter comprising substantially clay and silt. Also the sludge can be characterized as having about 0.5 to about 25 wt. percent bitumen. The solids contents of the sludge layer increase regularly from top to bottom by a factor of about 4-5. Portions of the solids are clays. The clays, dispersed by the processing, apparently have partially reflocculated into a fragile gel network. Through this gel, particles of larger-than-clay sizes are slowly settling. Generally this sludge layer cannot be recycled to the separation step because no additional bitumen is extracted. More specifically, sludge is not suitable for recycling to the hot water extraction process for the reason that its addition into the separation cell or the scavenger cell at the normal inlet means would raise the mineral content of the middlings of the cell to the extent that recovery of bitumen would be substantially reduced. Generally, the settling which does take place in the pond provides a body of water in which the concentration of mineral matter increases substantially from the surface of the pond to the bottom thereof. A third layer formed of sand also exists.
Roth et al has defined in U.S. Pat. No. 4,392,941 "overboarding" as the operation in which tailings are discharged over the top of the sand dike directly into the liquid pool. A rapid and slow settling process occurs but this distinction is not as acute as in the previously mentioned dike building and no mechanical compaction is carried out. The sand portion of the tailings settles rapidly to form a gently sloping beach, extending from the discharge point toward the pond interior. As the sand settles, a slurry drains into the pool and commences long-term settling. Thus water in ponds prepared by both dike building and overboarding can be included in the general definition of sludge in the present description.
As stated in U.S. Pat. No. 4,018,664 to Bain et al, experience has shown that, as the pond forms, the various components in the effluent discharge settle in the pond at varying rates. As an example, when the waste water containing sand, silt, clay and bitumen is discharged to the pond, the free bitumen normally immediately floats to the surface of the pond and the sand immediately settles to the bottom of the pond. However, after the surface bitumen cools and releases the entrapped air which originally caused it to float, it too will begin to settle toward the bottom of the pond. The silt and clay in the discharge settle in the pond at a substantially low rate as compared to the sand.
Bain et al has characterized a pond in U.S. Pat. No. 4,018,664 as follows: it can be pictured as a large body of water containing dispersed solids which are slowly settling toward the bottom of the pond. The mineral matter in the pond is in a constant but slow state of settling. Normally, the pond is constantly increasing in size because of the continuous addition of waste water and therefore the character of the pond is continually changing.
In processing tar sands to recover bitumen therefrom, the tar sands are excavated, extracted to remove the bitumen, whereafter the sand and other minerals are returned to the excavated area. As noted above, waste waters associated with the extraction step must be stored in a retention pond which is normally placed in one of the excavated areas. It is important that the excavated area be filled only with minerals and not with water since obviously the water is excess and therefore requires more storage volume than is available. If a retention pond associated with the hot water extraction of bitumen from tar sands is not treated to remove water layers which cannot normally be reused, such as sludge, the problem of a shortage of storage space is ever present.
Bain et al has further characterized a pond in U.S. Pat. No. 4,018,664 as follows: a waste water retention pond associated with hot water process for extracting bitumen from 140,000 to 150,000 tons of tar sands per day and having a surface area of about 1,000 acres and an average depth of 40 feet can be characterized somewhat as follows:
(a) From the surface of the pond to a depth of about 15 feet the mineral concentration which is primarily clay is found to be about 0.5 to 5.0 weight percent. This pond water can normally be recycled to a hot water extraction process without interfering with the extraction of bitumen from tar sands.
(b) The layer of water in the pond between 15 and 25 feet from the surface contains between 5.0 and 20 percent mineral matter. This water, if recycled to the separation cell feed with fresh tar sands, would increase the mineral content of the middlings portion of the cell to the point that little bitumen would be recovered.
(c) Finally, the section of the pond between 25 feet and the bottom of the pond contains 20 to 50 percent mineral matter and is normally referred to as sludge.
What is needed and what has been discovered by us is a process for the recovery of hydrocarbon or bitumen from tar sands. More specifically, what is needed and what has been invented by us is a process for the recovery of hydrocarbon or bitumen from tar sands and the rejection of recovered sand from the tar sands, all at the mining site. The recovered hydrocarbon or bitumen may be upgraded by sending the same to an upgrading unit.

Process for recovery of hydrocarbons and rejection of sand


A CPU can selectively execute a normal processing mode and a debugging mode on the basis of a control signal sent from a control unit. A first memory cell array is accessed in the normal processing mode, and a second memory cell array is accessed in the debugging mode. A sense amplifier and a bit line are shared by the first and second memory cell arrays. Consequently, it is possible to relieve an increase in the area of the semiconductor chip caused by existence of the two memory cell arrays. That is, an area of a semiconductor chip is reduced. A spare memory cell array may be provided for compensating for a defective cell of the first memory cell array. A refresh circuit may be provided for refreshing the first and second memory cell arrays.

1. Field of the Invention
The present invention relates to a microprocessor which can be incorporated in an ICE (in-circuit emulator) for use, and more particularly to improvement to reduce a size of the device having a memory for normal operation and a memory for debugging provided therein.
2. Description of the Background Art
It is said that an enhancement in efficiency of development of software is an important problem in a system using a microprocessor. For this purpose, a technique for performing debugging by using an ICE has been known well. In the conventional ICE, a memory for debugging (a so-called "trace memory") and a ROM for a monitor program (a program for executing a trace and the like) are provided on an outside of a microprocessor, and these circuits are mounted on a circuit board of the ICE. For this reason, there has been a problem that mounting cost of the ICE is high.
In order to improve this problem, it has been proposed that the memory for debugging is built in the microprocessor. FIG. 14 is a block diagram showing an example. As shown in FIG. 14, a microprocessor 150 is connected to a host system 161 and a control unit 162 so that an ICE 160 can be formed. The microprocessor 150 is built as an integrated circuit in a single semiconductor chip.
The microprocessor 150 comprises a CPU (central processing unit) 151. The CPU 151 operates on the basis of a control signal sent from the control unit 162 through a control signal line 165. A data signal is received and sent through a data signal line 154, a buffer 153 and a data signal line 164 between the CPU 151 and the control unit 162. The control unit 162 exchanges a control signal together with the host system 161 through a signal line 163.
The microprocessor 150 further comprises a memory 152 for debugging. The memory 152 is formed as a SRAM, and is addressed by an address signal sent from the CPU 151 through a signal line 155.
In the conventional microprocessor 150, however, a trace memory is formed by the SRAM. For this reason, there has been a problem that an occupied area of the memory of the microprocessor 150 on the semiconductor chip is great and cost of the semiconductor chip is high.

Microprocessor having a CPU and at least two memory cell arrays on the same semiconductor chip, including a shared sense amplifier


A method and system is provided to control and check run-time process dependencies. When a process manager receives a request to start a new process, the process manager accesses a configuration file to check if the new process depends on any other processes to be running and what versions of these prerequisite processes are required. If an exact version is specified in the configuration file, the prerequisite process version must match the exact version specified to be compatible with the new process. If a range of acceptable versions is specified in the configuration file, the prerequisite process version must fall within the range of acceptable versions to be compatible with the new process. If a minimum acceptable version is specified in the configuration file, then the prerequisite process version must be greater than or equal to the minimum acceptable version specified. If a maximum acceptable version is specified in the configuration file, then the prerequisite process version must be less than or equal to the maximum acceptable version specified. If the prerequisite processes are not running or the versions of the running prerequisite processes are not compatible with the new process, then the new process is not started. If the new process does not depend on any processes or all the prerequisite are running with compatible versions, then the new process may be started.

The architecture of high-performance Internet routers has advanced in the last several years to provide increased performance in routing ever-greater volumes of network traffic. It is not uncommon for a router to support numerous protocols as well as several applications for configuration and maintenance of the router tables, protocols, and network policies. These advances have increased the complexity of the router such that the management of applications and protocols running on the router is critical for reliable network performance.
In existing router management technology, the logic to support the applications, protocols, and associated management interfaces is centrally managed in a single master program. This can result in a single point of failure, meaning that even if there is a problem with only one protocol or application or interface, the entire program could crash, bringing the router down with it. In addition, if the master program needs to be updated, for example to accommodate a new protocol, then the master program must be brought down in order to perform the updates, thereby temporarily taking the router out of service.
In an effort to overcome some of the limitations in existing router management technology, management of applications, protocols, and associated management interfaces may be decentralized. However, this means that there will be several processes running simultaneously on both the active Router Protocol (RP) and line cards. These multiple processes may or may not be dependent on other processes which run on the same processor. Furthermore, those processes that are dependent on other processes may only be compatible with certain versions of those other processes. Since the processes share the limited resources of the processor, it is important to insure that the dependent processes are started only when the other processes on which they depend are already running and compatible to avoid taking up valuable resources unnecessarily.

Method and apparatus for controlling process dependencies


A motion control system has an enclosed assembly that encloses moving parts. A controller controls a motion of the moving parts and has an inhibit input that inhibits the motion. A sensor provides sensor outputs that depend on an assembly temperature and an assembly humidity in the enclosed assembly. A circuit provides a condensing condition output as a function of the sensor outputs. The condensing condition output couples to the inhibit input to inhibit the motion as a function of the sensor outputs.

When hard disc drives are used in laptop, desktop and server applications, the hard disc drive is enclosed in a computer housing. The thermal mass of the housing tends to buffer or slow down a rate of temperature drop in the disc drive when the surrounding environment cools. With these slower temperature drops, there is usually enough time for humidity in the disc drive to slowly vent into the surrounding environment through a filter so that condensation inside the disc drive is avoided. However, as smaller disc drives are increasingly used in portable devices such as MP3 music players and personal digital assistants (PDAs) which have low thermal mass, there are more rapid temperature drops in the disc drive and condensation inside the disc drive can occur. In particular, a disc drive may be carried from a warm humid indoor environment to a cold outdoor environment and condensation will form in the disc drive as the disc rapidly cools.
When condensation forms inside the disc drive, it can adversely affect disc write operations because moisture on the magnetic disc surface is known to adversely affect disc lubrication and head-media spacing. The condensation can cause head crashes. Condensation on the disc also causes an effective change in the coercivity of the media and will generally create bad writes and media defects.
The problem with condensation is particularly difficult in hard disc drives and other enclosed assemblies which are completely sealed except for a filter which keeps contaminating particles out of the enclosed assembly but permits pressure equalization. There is little exchange of air between an interior space of the disc drive and its surrounding environment, except during temperature changes. Changes in environment temperature can draw humid air into the disc drive, and then it is difficult to remove the humidity.
A method and apparatus are needed to prevent damage to moving parts in an enclosed assembly when moisture condensing conditions are present inside the enclosed assembly. Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.

Condensation compensation in a motion control system


The technology disclosed relates to identification of future activity options. In particular, it relates to identifying future activity options that are similar to a selected future activity, similar to past activities, that meet descriptive language criteria, that form compatible sequences of activities, or that form compatible multi-day sequences of activities. The technology disclosed also relates to rapid and convenient sorting through activity options.

The technology disclosed relates to identification of future activity options. In particular, it relates to identifying future activity options that are similar to a selected future activity, similar to past activities, that meet descriptive language criteria, that form compatible sequences of activities, or that form compatible multi-day sequences of activities. The technology disclosed also relates to rapid and convenient sorting through activity options.
There are abundant sources of information for purchasing plane tickets, booking tables and reading reviews. Some of the sources allow more or less localized searches. Many of the interfaces are cumbersome and require considerable study.
An opportunity arises to develop better interfaces for planning future activities. Better, more easily operated, more resilient and transparent consumer experiences and systems may result.

Dynamic sorting and inference using gesture based machine learning


A measurement agent for measuring a distance from the agent to a tag may include a transmitter and receiver for transmitting and receiving radio wave signals. The agent is arranged for changing the agent transmitter from a particular state wherein the agent transmitter transmits a particular radio wave interrogation signal towards a further state determined by the agent wherein the agent transmitter transmits a further radio wave interrogation signal when a signal behavior of a received radio wave response signal changes. Further, the measurement agent includes a counter for determining a time period between transmittance of a first radio wave interrogation signal and receipt of a radio wave response signal having a predetermined signal behavior. The agent also includes a processor for computing a distance between the agent and the tag, based on the determined time period and a multiple number of radio wave interrogation signals.

In known contactless distance measurement devices, the measurement principle is based on a relative strength of received radio wave signals. When the distance between the measuring agent and the object increases, however, also the measurement inaccuracy increases. Further, complex timing synchronisation schedules are applied to enable multiple measurement agents to perform a measurement. In addition, relatively complex and expensive electronic components are used for a practical implementation of the known measurement principle.
It may be desirable to provide a measurement agent, wherein at least one of the disadvantages identified above is reduced. In particular, the invention aims at obtaining a measurement agent wherein the measurement inaccuracy is less dependent on the distance between the agent and the tag.

Measurement agent, a tag, a method for measuring, a method for serving measuring and a computer program product

NEDERLANDSE ORGANISATIE VOOR TOEGEPAST-NATUURWETENSCHAPPELIJK ONDERZOEK TNO


Some exemplary embodiments of a III-nitride switching device with an emulated diode have been disclosed. One exemplary embodiment comprises a GaN switching device fabricated on a substrate comprising a high threshold GaN transistor coupled across a low threshold GaN transistor, wherein a gate and a source of the low threshold GaN transistor are shorted with an interconnect metal to function as a parallel diode in a reverse mode. The high threshold GaN transistor is configured to provide noise immunity for the GaN switching device when in a forward mode. The high threshold GaN transistor and the low threshold GaN transistor are typically fabricated on the same substrate, and with significantly different thresholds. As a result, the superior switching characteristics of III-nitride devices may be leveraged while retaining the functionality and the monolithic structure of the inherent body diode in traditional silicon FETs.

1. Field of the Invention
The present invention relates generally to transistors and switching circuits. More particularly, the present invention relates to III-nitride transistors and switching circuits.
2. Background Art
Silicon based transistors such as silicon metal-oxide-semiconductor field-effect transistors or MOSFETs may include the advantageous property of a body diode or an "intrinsic diode" due to their inherent silicon PN junctions. This "intrinsic diode" provides advantages such as inherent over-voltage (or under-voltage) protection for power conversion circuits without requiring a separate diode; thus reducing costs, improving efficiency, and simplifying circuit design.
On the other hand, III-nitride transistors such as gallium nitride high electron mobility transistors or GaN HEMTs are often preferable over traditional silicon based transistors for switching, and especially high voltage switching, applications. By providing higher breakdown voltage, higher temperature operation, reduced specific on-resistance, and other desirable traits, III-nitride transistors are especially suited for high power and high frequency switching applications such as efficient DC-DC power conversion circuits.
Unfortunately, since the "intrinsic diode" is only the result of a silicon FET structure, III-nitride transistors require a separate diode to provide the same benefits as the "intrinsic diode" in silicon transistors. However, integrating a monolithic diode in a GaN HEMT process is difficult and complex. Moreover, for high performance switching applications, the need for Schottky-like diode performance with low forward voltage drop and zero reverse recovery characteristics further complicates monolithic integration into a single device. Thus, while high performance III-nitride switching transistors are readily available, adoption is not yet as widespread in power conversion applications due to the lack of suitable methods to integrate a high performance diode with Schottky-like characteristics.
Thus, a solution is needed to provide III-nitride transistors such as GaN HEMTs with high performance Schottky-like diode functionality that is practical and not prohibitively complex or costly.