The present invention relates to an amino polymer, its main chain is attached via a —O— group to a structure represented by the following formula (I). The present invention also relates to a process for producing said amino polymer and to its use as fuel oil detergent. Compared with the prior art, the fuel oil detergent of the present invention has the advantages such as a lower manufacturing cost and an improved deposit formation inhibition performance.

Unsaturated olefins, aromatic hydrocarbons and small amounts of sulfur compounds in fuel oil easily react with oxygen to form colloids and eventually form carbon deposits, especially the generation of the deposits in engines may be accelerated at critical parts such as intake valves, nozzles, and combustion chambers, seriously affecting the engine's working performance, leading to engine startup difficulties, idling instability, poor driving, poor acceleration, serious power loss and other issues. In order to suppress the generation of such deposits in engines, many detergents have been developed in the art.
U.S. Pat. No. 5,112,364 discloses a process for the production of polyetheramines by polyoxybutylene ether amination of nonylphenol in the presence of nickel-containing catalysts, and said polyetheramines can be used as fuel oil detergents. However, said prior process has a defect that the cost of producing the polyetheramine is high, and the polyetheramine cannot be sufficient in terms of deposit generation inhibition performance when it is used as a fuel oil detergent.

Amine polymer and preparation method and use thereof

Abstract: In formula (I), groups and values are defined as described in the description.

RESEARCH INSTITUTE OF PETROLEUM PROCESSING, SINOPEC


The present invention relates to an extra light hydrocarbon liquid derived from highly paraffinic wax. This extra light hydrocarbon liquid is suitable for use as a lubricant additive diluent oil in oil soluble additive concentrates. This extra light hydrocarbon liquid derived from highly paraffinic wax has a viscosity of between about 1.0 and 3.5 cSt at 100° C. and a Noack volatility of less than 50 weight % and comprises greater than 3 weight % molecules with cycloparaffinic functionality and less than 0.30 weight percent aromatics. The extra light hydrocarbon liquid makes an excellent lubricant additive diluent oil because it has low volatility, low viscosity, good additive solubility, and excellent solubility in lubricant base oil stocks. The present invention also relates to finished lubricants comprising the oil soluble additive concentrates made with the extra light hydrocarbon liquid and finished lubricants comprising the oil soluble additive concentrates. The present invention further relates to processes for making these lubricant additive diluent oils, oil soluble additive concentrates, and finished lubricants.

Lubricant additives, especially automotive additives such as viscosity index improvers and detergent-inhibitor (DI) packages require lubricant additive diluent oils to make them useable. Accordingly, lubricant additive diluent oils are used to dissolve lubricant additives to provide oil soluble additive concentrates. These oil soluble additive concentrates make the additives easier to transport, handle, and ultimately blend into lubricant base oils to provide a finished lubricant. The oil soluble additive concentrates are not useable or suitable as finished lubricants on their own. Rather, the oil soluble additive concentrates are blended with lubricant base oil stocks to provide a finished lubricant. It is desired that the lubricant additive diluent oils readily solubilize the lubricant additive and provide an oil additive concentrate that is readily soluble in the lubricant base oil stocks. In addition, it is desired that the lubricant additive diluent oils not introduce any undesirable characteristics, including, for example, high volatility, high viscosity, and impurities such as heteroatoms, to the lubricant base oil stocks and thus, ultimately to the finished lubricant.
Different lubricant additive diluent oils require differing amounts of lubricant additive diluent oil to provide a suitable oil soluble additive concentrate. By way of example, oil soluble additive concentrates comprising gear oil additive packages may contain as little as 25% weight lubricant additive diluent oil. Oil soluble additive concentrates comprising DI packages typically contain about 50% weight lubricant additive diluent oil. Oil soluble additive concentrates comprising viscosity index improver typically contain about 90% weight or more lubricant additive diluent oil.
Currently, the lubricant additive diluent oils used with most DI packages and viscosity index improvers are highly aromatic base oils that fall into API Group I. API Group I base oils, with their high solvency and good availability, have been preferred as lubricant additive diluent oils. However, these Group I oils have only average to poor low temperature performance, and they are much more susceptible to oxidation than modern oils, which are more highly saturated. In addition, Group I base oils have lower viscosity indexes (VI) and higher volatility than other base oils. Moreover, Group I base oils have high sulfur concentrations. Lubricant additive diluent oils can comprise up to 5 to 10 weight percent of a finished lubricant. Accordingly, the properties of the lubricant additive diluent oils are important as undesirable properties in the lubricant additive diluent oils can negatively impact the properties of the finished lubricant. Although more desirable in terms of their properties for the finished lubricant, conventional API Group II, conventional Group III, and Group IV base oils are difficult to use as lubricant additive diluent oils due to their poor ability to solubilize additives. Therefore, these base oils are not practical as lubricant additive diluent oils.
When added to lubricant base oil stocks, typical oil soluble additive, concentrates comprising DI packages or viscosity index improvers, tend to thicken the finished lubricant formulation and impair its low-temperature performance. Low viscosity lubricant additive diluent oils, which have been used in the past in an attempt to avoid thickening the finished lubricant, have either had high volatility or poor additive solubility, making them unsuitable for most applications. When added to engine oils, the typical oil soluble additive concentrates tend to adversely impact the cold-cranking simulator (CCS) viscosity and Mini-Rotary Viscometer (MRV). When added to automatic transmission fluid and gear oils, the typical oil soluble additive concentrates tend to adversely impact the Brookfield Viscosity at low temperature.
Accordingly, lubricant additive diluent oils with low viscosity, low volatility, and low concentrations of impurities, such as sulfur-containing compounds, are desired. Typical lubricant base oils with low volatilities also have high viscosities rendering them unsuitable for most applications, and typical lubricant base oils with low viscosities also have low volatilities and poor additive solubility rendering them unsuitable for most applications.
Engine manufacturers worldwide are introducing chemical limits on engine oils and additives that they believe will provide the safe margins for operation that their exhaust aftertreatment hardware requires. These requirements will directly impact what is suitable for use as additives, lubricant base oils stocks, and lubricant additive diluent oils. Low sulfur and phosphorus limits on engine oils are being proposed. At a limit of about 0.3 weight % sulfur, zinc dithio-diphosphate antiwear additives need to be partially replaced with more costly additives, and reduced sulfur detergents and base oils are needed to provide formulation flexibility. As limits move toward 0.2 weight % sulfur, reduced or zero-sulfur lubricant base oils and diluent oils become essential to meet formulation targets. International Lubricants Standardization and Approval Committee (ILSAC) GF-4 passenger car engine oils, API PC-10 heavy duty engine oil, and other high quality finished lubricant specifications call for low sulfur formulations.
The ILSAC/Oil Committee adopted the new GF-4 specification for passenger car motor oils on Jan. 8, 2004, with a recommended start date for introducing GF-4 into the marketplace of Jul. 1, 2004. A new bench test requirement for engine oils meeting the GF-4 specification are maximum sulfur content by ASTM D 1552. As such, a 10 W oil may have a maximum of 0.7 weight % sulfur, while 0 W, and 5 W oils may have a maximum of 0.5 weight % sulfur. In addition, the oils meeting the GF-4 specification must have a Noack volatility by ASTM D 5800 of less than 15 weight % after one hour at 250° C., and a simulated distillation by ASTM D 6417 with a maximum of 10% at 371° C. API PC-10 is a proposed specification for heavy duty diesel engine oil and is expected to be approved in 2006 or 2007. It is expected that PC-10 oils will also have reduced limits for sulfur, similar to those amounts called for GF-4 passenger car motor oils.
Accordingly, lubricant additive diluent oils with low sulfur, excellent additive solubility, good elastomer compatibility, low volatility, low viscosity, high oxidation stability, good low temperature properties, and excellent solubility in the lubricant base oils are desired.

This patent is subject to a terminal disclaimer.

Processes for producing extra light hydrocarbon liquids


A method for hardening an extensible firmware framework and system in which the framework is implemented. In accordance with the method, a resource access policy that defines rules to allow or disallow access to designated system resources, such as memory and I/O, is defined. During execution of firmware-based event handlers, event handler code may seek to access a designated system resource. In response thereto, access to the system resource may be determined based on a security status of a firmware-based event handler in consideration of any applicable rules defined by the resource access policy. For example, a resource access policy may allow only secure event handlers to access selected portions of memory, while preventing non-secure event handlers from accessing the same. In this manner, errant and malicious event handlers are prevented from damaging critical resources.

1. Field of the Invention
The present invention concerns computer systems in general, and a scheme for hardening a System Management Mode (SMM) framework and other similar modes of processors in particular.
2. Background Information
Since the 386SL processor was introduced by the Intel Corporation, SMM has been available on IA32 processors as an operation mode hidden to operating systems that executes code loaded by BIOS or firmware. SMM is a special-purpose operating mode provided for handling system-wide functions like power management, system hardware control, or proprietary OEM-designed code. The mode is deemed "hidden" because the operating system (OS) and software applications cannot see it, or even access it.
IA32 processors are enabled to enter SMM via activation of an SMI (System Management Interrupt) signal. A similar signal called the PMI (Processor Management Interrupt) signal that is roughly analogous to the SMI signal is used for Itanium™-class processors. For simplicity, both SMI and PMI signals are sometimes referred to as xMI signals herein.
Most BIOS implementations that leverage the SMM capability of the foregoing Intel processors simply register a monolithic section of code that is created during the build of the BIOS to support a specific function or set of functions particular to systems that use the BIOS. This code comprises 16-bit assembly in IA32 and 64-bit assembly for Itanium processors. The monolithic code segments for these legacy implementations runs from beginning to completion in response to all xMI activations.
Recently, an extensible SMM framework has been introduced that enables the registration and execution of third-party SMM code, thus allowing SMM to perform operations that extend beyond those provided by the monolithic code solution. However, this presents a new problem. When a monolithic code segment is employed, its trustworthiness is inherent since it is BIOS provider. In other words, the SMM code can be trusted because if a BIOS vendor provided errant or malicious code, that vendor would soon be out of business. In contrast, the current extensible SMM framework, by itself, cannot protect against rogue or malicious code present in the third-party SMM code.


A speech synthesis system can record concatenation costs of most common acoustic unit sequential pairs to a concatenation cost database for speech synthesis by synthesizing speech from a text, identifying a most common acoustic unit sequential pair in the speech, assigning a concatenation cost to the most common acoustic sequential pair, and recording the concatenation cost of the most common acoustic sequential pair to a concatenation cost database.

1. The Field of the Invention
The invention relates to methods and apparatus for synthesizing speech.
2. Description of Related Art
Rule-based speech synthesis is used for various types of speech synthesis applications including Text-To-Speech (TTS) and voice response systems. Typical rule-based speech synthesis techniques involve concatenating pre-recorded phonemes to form new words and sentences.
Previous concatenative speech synthesis systems create synthesized speech by using single stored samples for each phoneme in order to synthesize a phonetic sequence. A phoneme, or phone, is a small unit of speech sound that serves to distinguish one utterance from another. For example, in the English language, the phoneme /r/ corresponds to the letter "R" while the phoneme /t/ corresponds to the letter "T". Synthesized speech created by this technique sounds unnatural and is usually characterized as "robotic" or "mechanical."
More recently, speech synthesis systems started using large inventories of acoustic units with many acoustic units representing variations of each phoneme. An acoustic unit is a particular instance, or realization, of a phoneme. Large numbers of acoustic units can all correspond to a single phoneme, each acoustic unit differing from one another in terms of pitch, duration, and stress as well as various other qualities. While such systems produce a more natural sounding voice quality, to do so they require a great deal of computational resources during operation. Accordingly, there is a need for new methods and apparatus to provide natural voice quality in synthetic speech while reducing the computational requirements.

Recording concatenation costs of most common acoustic unit sequential pairs to a concatenation cost database for speech synthesis


The present invention relates to a door lock device for a motor vehicle door, comprising: a door retaining bar mounted on the door or the body to be pivotable, and including one first side and a profiled section formed on the first side; a first braking element arranged respectively on the other part (door or body), which is applied by sections on the first side of the door retaining bar under the effect of a preload, and which, with the profiled section of the first side, defines retaining positions. The inventive door lock device, which enables the door to be selectively opened via defined retaining positions, in particular by a specific stop, is produced according to the present invention such that an actuating device is associated with the first braking element, and so that the actuating device enables the first braking element to be moved against the preload to be no longer in contact with the first side of the door retaining bar.

The invention relates to a door lock device.
Door lock devices are known from practice which comprise a pivotably mounted door retaining bar, with a profiled section being provided on at least one side of the door retaining bar, together with which a first braking body, which is mounted under prestress in relation to the door retaining bar, defines a retaining position, the first braking body usually being arranged in a depression of the profiled section of the door retaining bar in one of the retaining positions. A stop, in particular an end stop, can be produced by suitable configuration of the profiled section, for example by the profiled section of the door retaining bar being designed such that it rises steeply such that the first braking body cannot be guided over the steeply rising profiled section without a considerable effort. Difficulties arise in such a manner that, in the case of a door lock device, the door retaining bar of which has a stop formed by a steeply protruding profiled portion, the door cannot be opened as an operator chooses, in particular beyond the position defined by the stop formed.
DE 100 25 185 A1 describes a door lock device for a door of a motor vehicle, which comprises a door retaining bar, on the first side of which a profiled section is formed, the door retaining bar interacting with a first braking body which bears against the first side with the profiled section under a stress caused by a helical spring, the profiled section having depressions which define the retaining positions. It is disadvantageous that it is not possible to bypass individual retaining positions or a stop if the need arises, therefore the stop which, for example, defines a 90° open position of the door, not being bypassed, if an operator chooses, in such a manner that the door can be transferred from the 90° open position into a position with a greater opening angle, for example 180°.


The capacitive coupling between two adjacent bitlines of a NAND memory device may be exploited for boosting the voltage of bitlines that are not to be programmed in order to inhibit program operations on them. The even (odd) bitlines that include cells not to be programmed are biased with a first voltage for inhibiting them from being programmed while the even (odd) bitlines that include cells to be programmed are grounded. The adjacent odd (even) bitlines are biased at the supply voltage or at an auxiliary voltage for boosting the bias voltage of the even (odd) bitlines above the supply voltage. The bias voltage of the even (odd) bitlines that include cells not to be programmed is boosted because of the relevant parasitic coupling capacitances between adjacent bitlines.

A logic state is stored in a cell by programming its threshold voltage. In nonvolatile memory devices, this is done by transferring a certain electrical charge in a floating gate of the cell.
The storage capacity of memory devices can be multiplied by storing more than one bit of information in each single cell of the same physical structure as if it is intended to store a single information bit. This is in addition to increasing the integration density of arrays of cells individually addressable through wordlines and bitlines of the array.
Though based on the same physical mechanisms, the programming and reading of cells that store more than one bit (multi-level cells) are carried out with techniques that differ from those used for cells that store a single bit (two-level cells).
To read a two-level memory array cell, a certain voltage is applied to the control gate (wordline) of the cell. The value of a reading voltage is between the threshold voltage of an erased cell and the threshold voltage of a programmed cell such that when the cell is programmed, the reading voltage is lower than its threshold voltage. As a consequence, no current flows through the cell. In contrast, when the cell is erased, the reading voltage is higher than its threshold voltage, and thus a current flows through the cell.
In four-level cells, two bits of information may be stored by making the programming voltages of the different thresholds that may be set for one memory cell define four different intervals. Each interval is associated to a respective two-bit datum. A reading operation is carried out by comparing an electrical parameter, correlated with the current that flows through the cell, with four distinct reference intervals. The intervals are defined by the three different thresholds that may be programmed for each single cell. Each cell is associated with a respective two-bit datum, and thus determining the logic datum associated to the distinct interval of values (threshold voltage distributions) in which the measured electrical parameter falls. This approach for a multi-level operation of the cells is applicable to volatile memory cells, such as DRAMs, as well as to nonvolatile memory devices, such as EEPROMs and FLASH-EPROMs.
A basic circuit scheme of two memory array bitlines and a page buffer of a four-level memory of the FLASH type is depicted in FIG. 1. The page buffer manages the operations of reading the information stored in the memory cells of a selected memory page, or writing new information in the cells. The selection transistors MDSL and MSSL connect to the bitline or to ground, respectively, the series of memory cells.
The basic operations that usually are performed on the memory cells are a page read (an operation involving reading data from a selected memory page), a page program (writing data into a selected memory page), and an erase operation (the content of the memory cells is erased).
In four-level memory devices, a two-bits datum may be stored in each cell by programming the latter in any one of four different states. Each one is associated with a corresponding logic value of the two-bits datum. Usually, the programming state of a memory cell is defined by the threshold voltage value of the transistor structure that is included in the memory cell structure.
In a memory cell adapted to store two bits, the threshold voltage values of the memory cells may assume one of four different values or ranges of values. A typical choice is to associate the logic values of the stored bit pair to the four different states according to a binary sequence 11, 10, 01, and 00, as shown in FIG. 2, corresponding to increasing threshold voltage values, with the logic value 11 that is associated with the state of the lowest threshold voltage value (erased state). The others are associated in succession to states of increased threshold voltage values.
The cells of a memory page (wordline), both if they are intended to store one bit or two bits of information, are programmed in parallel by incrementing stepwise their threshold voltage. Typically, the PAGE BUFFER biases the bitline at the ground potential for programming the cells, or to a supply potential VDD for not programming the cells. The control voltage DSL of the selection transistor MDSL of the series (stack) to which the wordline to be programmed belongs is at the supply voltage VDD. This is while the control signal SSL (source selector) is at the ground potential while the source line (not depicted) is at the voltage VDD.
A typical timing diagram of the main signals during the execution of the sequence of steps for programming a bitline BLE is depicted in FIG. 4. All the bitlines are charged (FIG. 3), and the gate of the selection transistors DSL are brought at the supply potential VDD. The channels are biased at the voltage VDD-VTH, where VTH is the threshold of the selection transistors MDSL.
Then the control signal SELBLE is asserted while the signals DISCHE, DISCHO are switched to turn off the respective transistors, and the page buffer discharges only the bitlines that contain cells that should be programmed. This is while leaving at the supply voltage VDD all the cells that should not be programmed, as shown in FIG. 5. After this phase, all the wordlines are biased at an intermediate voltage, typically about 8 to 10V. Then the wordlines to be programmed are biased from this intermediate voltage to the programming voltage.
This step may take place in two ways. One way is for the gate of the cell to be programmed to be directly brought to the programming voltage. But in this case, the resistance and the capacitance of the row determines the charge time. Alternatively, the programming voltage is attained in a controlled fashion by imposing a voltage ramp with a desired slope, for example a slope of 1 V/μs.
Because of the very small pitch of the cells, the coupling capacitances between the wordline and the line DSL (but also among the wordlines themselves) is relatively large. If the gate of the selected cell is biased directly at the programming voltage, the voltage on the line DSL could increase, especially when the cell adjacent to the transistor MDSL is to be programmed above the voltage VDD.
Since the unselected bitlines are biased at the voltage VDD, increasing the gate voltage of the transistor MDSL could reduce the bias voltage of the relative channel. Because of the capacitive coupling between the wordline and the line DSL, the gate voltage of the transistor MDSL could surpass the supply voltage VDD by at least a threshold voltage and the selection switch MDSL, could be turned on. This would connect the channel, at a boosted voltage, to the respective bitline that is at the supply voltage. As a consequence, the cells that are on the same wordline of a cell to be programmed could be programmed even if they should not be programmed.
To address this problem, the bitline is biased at a voltage larger than VDD. The drawbacks of this approach is that there is an increment of silicon area consumption because of the need of integrating additional charge pump generators capable of supplying a current and a voltage sufficient for inhibiting the cells not to be programmed. Also, the time required for biasing all the bitlines is increased.

Method of programming cells of a NAND memory device


Improved techniques for communicating between a portable electronic device and an accessory (or auxiliary) device are disclosed. The accessory device can augment or supplement the functionality or capabilities of the portable electronic device. For example, in one embodiment, the accessory device can provide wireless communication capabilities to the portable electronic device. In one embodiment, the portable electronic device pertains to a portable media player and thus provide media data for storage, playback or transmission. In one embodiment, the accessory device is attachable to the portable electronic device.

1. Field of the Invention
The present invention relates to electrical devices and, more particularly, to electrical devices, such as media players, that communicate with external devices.
2. Description of the Related Art
A media player stores media assets, such as audio tracks, that can be played or displayed on the media player. One example of a portable media player is the iPod® media player, which is available from Apple Computer, Inc. of Cupertino, Calif. Often a media player acquires its media assets from a host computer that serves to enable a user to manage media assets. The host computer can execute a media management application to acquire and manage media assets. One example of a media management application is iTunes® produced by Apple Computer, Inc.
Portable media players, such as MP3 players, are able to play music for users often via earphones or a headset. A portable media player typically includes one or more connectors or ports that can be used to interface to the portable media player. For example, the connector or port can enable the portable media player to couple to a host computer, be inserted into a docking system, or receive an accessory device. Typically, portable media players are dedicated to playing media. However, there exist today various different types of accessory devices that can be coupled to portable media players. For example, a remote control can be connected to the connector or port to allow the user to remotely control the portable media player. As another example, an automobile can include a connector and the portable media player can be inserted onto the connector such that an automobile media system can interact with the portable media player. As still another example, a microphone accessory device can be connected to a portable media player to enable voice recording. Yet still another example is a FM radio controller accessory that includes a FM tuner and a controller. Still yet another example is a camera connector that connects to a portable media player as well as a camera (via USB) and serves to facilitate transfer of images from the camera to the portable media player.
Currently, portable media players can interact with attached accessories in limited ways. However, as accessories become more complex and/or more integrated with operation of portable media players, more sophisticated interaction with accessories is required. Thus, there is a need for improved techniques to enable portable media players to communicate with accessory devices in accordance with a controlled protocol.

Communication protocol for use with portable electronic devices


A method and system suitable for recording/reproducing audio-visual data on or from a hard disk or other storage media that can be accessed in random. Two streams, stream #1 and stream #2, are set. Then, 2000 sectors are set to the stream #1 and a specified number of sectors to the stream #2. By specifying this stream number (stream #1 or #2) and the audio-visual (AV) logical block address of the stream, the AV stream data recorded on the hard disk can be accessed. Each AV stream begins with zero and ends at the maximum AV stream LBA.

1. Technical Field
The present invention relates to recording/reproducing methods for hard disk drives, and more particularly to techniques for recording and reproducing audio-visual data (hereinafter referred to as AV data).
2. Description of the Related Art
A typical storage medium to record AV data such as TV programs is magnetic tape, and video tape recorders (hereinafter referred to as VTRs) for recording AV data on this magnetic tape are widely used. VTRs are used not only for recording TV programs but also for reproducing video tape recorded movies and other programs (they are sometimes referred to as simply programs, including TV programs).
In the VTR described above, there are the following problems and demands. First, in the case where a plurality of programs have been recorded on a single video tape, fast forward or reverse winding of the tape for queueing-up of a program to be reproduced is time-consuming. This is because magnetic tape is a storage medium unsuitable for random access. Also, for example, there is a demand that while recording a TV program, viewers desire to view the recorded program from an arbitrary point, or that while recording a certain TV program, viewers desire to view another program previously recorded. Although this demand suggests the appearance of video recorders having a simultaneous recording/reproducing function, conventional VTRs are not equipped with such a function. With respect to the above problem, employing a hard disk drive, which is excellent in random access, in recording and reproducing AV data has been proposed and in some cases has been put to practical use.
AT attachment interfaces standardized by ATA standards have been designed with the primary object of handling data for computers. For this computer data, data perfection is the most important element and devices are required to maintain data as perfectly as possible.
On the other hand, application data for AV (AV data) is not required to be as perfect as computer data, but has a characteristic that a certain amount of data must be handled continuously within a predetermined time. That is, AV application data systems have no great problem even if each individual data includes an imperfect portion, but has a problem if a video stops, such that continuity in data is lost. Since AV application data is usually a group (or lump) of data arrayed continuously on a time axis, it is called a stream. Therefore, in this specification, such a data group is likewise called a stream and data included in the stream is called stream data.
In the case where AV data having such characteristics are recorded and reproduced by employing conventional hard disk drives, the conventional hard disk drives cannot satisfy a user""s operability requirements because such drives have been designed for reading out or writing data suitable for computers.
Accordingly, it is an object of the present invention to provide a data recording/reproducing unit, a data recording/reproducing method, and a hard disk controller suitable for recording/reproducing AV data on or from a hard disk or other storage media that can be accessed randomly.
The present invention is characterized in that it enhances user friendliness in handing AV data, by defining regions, on which a stream, i.e., a lump of data continuous in a time-series manner is recorded, on a hard disk and accessing that data lump in the unit of the recording region. That is, the data recording/reproducing unit of the present invention comprises: a randomly accessible hard disk on which a lump of data continuous in a time-series manner is recorded; recording-region setting means for defining a plurality of recording regions for the data lump with respect to the hard disk and allocating sectors to each of the recording regions, the sectors being given consecutive numbers; and a controller for controlling recording/reproduction of the data lump with respect to the hard disk by specifying the recording region and the sectors.
Accordingly, the data recording/reproducing unit of the present invention, recording or reproduction of data, for example, TV programs, can be executed, by specifying the aforementioned recording regions and sectors. Also, in the data recording/reproducing unit of the present invention, a plurality of recording areas are defined. For example, in the case of two recording regions, the process of recording a video on one recording region and the process of reproducing another video from another recording region can be performed in parallel.
In the data recording/reproducing unit of the present invention, the recording/reproduction of data is performed in the order of the numbers of the sectors, given the consecutive numbers. More specifically, when recording data, the data is written in the order of the sector having a smaller number, and in reproducing data, the data is read out in the order of the sector having a smaller number.
Here, in conventional hard disks, the sectors are given logical consecutive numbers beginning with zero, i.e., logical block addresses (LBAs), respectively. However, the recording regions and sectors of the present invention are provided separately from conventional LBAs. Note that in the present invention, the consecutive numbers given to the sectors are called stream LBAs.
In accordance with the present invention, there is provided a data recording method comprising the steps of: developing a data stream on a data storage medium accessible in random, the data stream being a unit in which a group of data continuous along a time axis is recorded; allocating to the data stream a plurality of sectors given consecutive numbers; and specifying the number of the sector at which writing of the data is started, and then writing the data to the sectors in the order of the consecutive numbers. In this data recording method, a single stream may be developed on the storage medium, however, there is a need to develop a plurality of data streams in order to execute simultaneous recording-reproduction described previously. In addition, if a plurality of data streams are present, different groups of data can be recorded in the same time period on one data stream and another data stream of the plurality of data streams, respectively. In recording/reproducing AV data, there is a need to transfer 1.5 M bytes of data for each 0.5 seconds. If we assume the data transfer capability of the interface of a hard disk drive is 3 M byte/s, it becomes possible to record different groups of data in the same time period, by alternately performing the process of writing one group of data to one data stream at a rate of 1.5 M bytes/sec and the process of writing the other group of data to another data stream at a rate of 1.5 M bytes/sec.
In accordance with the present invention, there is provided a data recording method comprising the steps of: developing a plurality of data streams accessible at random, the data streams being units in which a group of data continuous along a time axis is recorded; giving a number to each of the plurality of data streams developed on the data storage medium on a data storage medium; allocating to each data stream a plurality of sectors given consecutive numbers; and writing the data group to the sectors in the order of the consecutive numbers, and if another group of data is present continuously after the writing of the data group reaches the sector of the last number of the consecutive numbers, writing the other data group in sequence from its sector given the first number of the consecutive numbers. In the case where recording is performed up to the last data stream LBA when AV stream data is not completed, i.e., when a TV program is being recorded, this data recording method records the TV program continuously from the first data stream LBA. In this specification, this recording is called seamless recording.
In accordance with the present invention, there is also provided, in a method of reading out data from a storage medium on which a plurality of data streams have been recorded in data stream units, each data stream being a group of data continuous along a time axis, a data reproducing method, comprising the steps of: specifying a data stream on which data to be reproduced has been recorded; specifying a start position in the specified data stream at which the data is read out; and starting reading of the data from the specified position. In this data reproducing method, the data stream is divided into micro-units having a predetermined capacity, and each micro-unit is given consecutive numbers. Specification of the start position at which the data is reproduced can be performed by specifying the number. The number given to the micro-unit refers to the data stream LBA.
In accordance with the present invention, there is also provided a method of reading out data from a storage medium on which a plurality of data streams have been recorded in data stream units, each data stream being a group of data continuous along a time axis, the method comprising the steps of: specifying a data stream on which data to be reproduced has been recorded; specifying a start position in the specified data stream at which the data is read out; and starting reading of the data from the specified position, and after the reading of the data has reached the end point of the data stream, reading out data in sequence from the start point of the data stream. In the case where reproduction is performed up to the last data stream LBA during reproduction of a recorded TV program, this data reproducing method performs reproduction continuously from the first data stream LBA. In this specification, this reproduction is called seamless reproduction.
While recording of data and reproduction of data have been described separately, the present invention includes the process of recording data and the process of reproducing data in parallel. That is, in accordance with the present invention, there is provided a data recording/reproducing method comprising: a writing process having (a) a step of developing a plurality of data streams on a data storage medium accessible in random, the data streams being units in which a group of data continuous along a time axis is recorded, (b) a step of allocating to each data stream a plurality of sectors given consecutive numbers, and (c) a step of writing data to the sectors in the order of the consecutive numbers; and a reading process having (a) a step of specifying the data stream on which data to be reproduced has been recorded, (b) a step of specifying a start position in the specified data stream at which data is read out, and (c) a step of starting reading of data from the specified position; wherein the writing process and the reading process are executed in parallel.
The present invention is also executed as the data recording-reproducing method, as described above. However, the invention may be carried out as a controller for hard disk drives. Therefore, in accordance with the present invention, there is provided a hard disk controller for controlling reading and writing of data with respect to a hard disk drive, the hard disk controller comprising: recording-region setting means for defining a plurality of recording regions, on which a lump of data is recorded, with respect to a hard disk and allocating to each recording region a plurality of sectors given consecutive numbers; and data specification means for specifying data which is to be read out from or written to the hard disk, by specifying the recording region and the sectors.
Furthermore, the present invention may also be executed as a method of recording/reproducing a group of audio-visual data. Therefore, there is provided a method comprising the steps of: developing a plurality of data streams on a data storage medium accessible in random, the data streams being units in which the audio-visual data group is recorded; dividing each of a plurality recording regions into predetermined recording units; and performing recording/reproduction of the audio-visual data group for each recording region.

Data recording/reproducing unit, data recording method, data reproducing method, data recording/reproducing method, hard disk controller, and AV-data recording/reproducing method

International Business Machines Corporation


A tray denesting apparatus is provided comprising a receptacle for holding at least one nested stack of packing trays. A conveyer belt is further provided for receiving each of the packing trays upon release from the receptacle. The denesting apparatus has at least one set of soft flexible suction cups disposed below the conveyer belt and which are disposed on a bellows assembly which is moveable between a first position and a second position so that at least one of the soft flexible suction cups may adhere to a first one of the packing trays, and successive packing trays. The tray denester further may include an automatic adjustment apparatus to correspond with selected size parameters of the trays being utilized. As a result, an individual tray may be removed from the receptacle, deposited on the conveyer belt and the conveyer belt then advancing the selected tray to the required area of use.

1. Field of the Invention
The present invention relates to tray dispensing devices. More particularly it relates to a tray dispensing device for molded trays of a variety of sizes which retains a stack of nested trays and dispenses individual trays from the nested stack.
2. Description of the Related Art
Trays for dispensing food items are widely known. Automatic tray dispensers for use in the packaging of such food items may be found in U.S. Pat. No. 5,788,116, Adjustable Tray Dispenser. Similarly, the following ten United States patent describe denesting devices which utilizes suction at some point in the apparatus: U.S. Pat. Nos. 6,623,236; 6,159,322; 5,704,194; 5,700,004; 5,133,169; 5,064,093; 5,013,213; 4,991,741; 4,350,466; and 4,260,311. However, a problem has remained in the tray denesting field for accurately separating one tray from a stack of trays, for preventing jamming of such denesting apparatus and for denesting trays having irregularly shaped surfaces thereon. In addition, although adjustable tray denesting apparatus have been provided in the past, no known apparatus includes automatic adjustment of the hopper for a specified number of different size trays.
It has also been known in the art to use suction devices from removing a single item from a stack of items. However, such devices have had the single item removed from the top o the stack. It was unknown to remove a single item, such as a tray, from the bottom of a stack using suction.

Variable-sized molded product tray denesting apparatus


A patient positioning apparatus (30, 330) is provided for use with a patient-support device (20, 320). The patient positioning apparatus (30, 330) is used to pull a sheet (32, 332) on the patient-support device (20, 320) while a patient is lying on the sheet (32, 332) to position the patient in a desired location on the patient-support device (20, 320).

The present invention relates to an apparatus for orienting a patient on a patient-support device, such as a hospital bed. More particularly, the present disclosure relates to an apparatus for pulling a patient toward a head end of a patient support device.
Some patient-support devices, such as hospital beds, stretchers, surgical tables, and the like, have mechanisms for articulating, raising, lowering, and/or tilting a patient-support portion of the device relative to a base of the device. When a head section of the patient-support portion of the device is raised to move the patient from a supine position to a sitting position, it is not uncommon for the patient to slide down the head section and move toward a foot end of the device. Thus, the patient may be shifted too far toward the foot end of the patient-support device when the head section is lowered back down to return the patient to the supine position. Some prior art devices, such as those shown in U.S. Pat. Nos. 5,608,929 and 5,280,657 and those shown in U.S. patent application Publications Nos. 2002/0083521 A1 and 2002/083522 A1, include mechanisms for pulling a patient toward the head end of a hospital bed.


An emitter switched thyristor with buried dielectric layer includes a contiguous P-N-P-N series of semiconductor regions between an anode contact and cathode contact. These regions correspond to an anode region of second conductivity type, a first base region of first conductivity type, a second base region of second conductivity type on the first base region, and a floating emitter region contacting the second base region and forming a P-N junction therewith. In addition, a field effect transistor is also provided between the cathode contact and the floating emitter for controlling turn-on and turn-off. An insulating region is also provided between the cathode region and the second base region and prevents the formation of a parasitic thyristor between the cathode contact and the anode contact. The insulating region preferably includes a buried dielectric layer selected from the group consisting of SiO.sub.2, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3 and MgAl.sub.2 O.sub.4. The insulating region is preferably formed using SIMOX processing techniques.

The development of semiconductor switching technology for high power applications in motor drive circuits, appliance controls and lighting ballasts, for example, began with the bipolar junction transistor. As the technology matured, bipolar devices became capable of handling large current densities in the range of 40-50 A/cm.sup.2, with blocking voltages of 600 V.
Despite the attractive power ratings achieved by bipolar transistors, there exist several fundamental drawbacks to the suitability of bipolar transistors for all high power applications. First of all, bipolar transistors are current controlled devices. For example, a large control current into the base, typically one fifth to one tenth of the collector current, is required to maintain the device in an operating mode. Even larger base currents, however, are required for high speed forced turn-off. These characteristics make the base drive circuitry complex and expensive. The bipolar transistor is also vulnerable to breakdown if a high current and high voltage are simultaneously applied to the device, as commonly required in inductive power circuit applications, for example. Furthermore, it is difficult to parallel connect these devices since current diversion to a single device occurs at high temperatures, making emitter ballasting schemes necessary.
The power MOSFET was developed to address this base drive problem. In a power MOSFET, a gate electrode bias is applied for turn-on and turn-off control. Turn-on occurs when a conductive channel is formed between the MOSFET's source and drain regions under appropriate bias. The gate electrode is separated from the device's active area by an intervening insulator, typically silicon dioxide. Because the gate is insulated from the active area, little if any gate current is required in either the on-state or off-state. The gate current is also kept small during switching because the gate forms a capacitor with the device's active area. Thus, only charging and discharging current ("displacement current") is required. The high input impedance of the gate, caused by the insulator, is a primary feature of the power MOSFET. Moreover, because of the minimal current demands on the gate, the gate drive circuitry and devices can be easily implemented on a single chip. As compared to bipolar technology, the simple gate control provides for a large reduction in cost and a significant improvement in reliability.
These benefits are offset, however, by the high on-resistance of the MOSFET's active region, which arises from the absence of minority carrier injection. As a result, the device's operating forward current density is limited to relatively low values, typically in the range of 10 A/cm.sup.2, for a 600 V device, as compared to 40-50 A/cm.sup.2 for the bipolar transistor.
On the basis of these features of power bipolar transistors and MOSFET devices, hybrid devices embodying a combination of bipolar current conduction with MOS-controlled current flow were developed and found to provide significant advantages over single technologies such as bipolar or MOSFET alone. Thus, in the insulated gate transistor (IGT), disclosed in an article by inventor B. J. Baliga, and M. S. Adler, R. P. Love, P. V. Gray and N. Zommer, entitled "The Insulated Gate Transistor: A New Three terminal MOS Controlled Bipolar Power Device," IEEE Trans. Electron Devices, ED-31, pp. 821-828 (1984), on-state losses were shown to be greatly reduced when compared to power MOSFETs. This was caused by the conductivity modulation of the IGT's drift region during the on-state. Moreover, very high conduction current densities in the range of 200-300 A/cm.sup.2 can also be achieved. Accordingly, an IGT can be expected to have a conduction current density approximately 20 times that of a power MOSFET and five (5) times that of an equivalently sized bipolar transistor. Typical turn-off times for the IGT can be expected to be in the range of 10-50 .mu.s. A cross-sectional representation of a typical insulated gate transistor is shown in FIG. 1.
Although gate-controlled transistors, such as the IGT, represent an improvement over using bipolar or MOSFET devices alone, even lower conduction losses can be expected by using a thyristor. This is because thyristors offer a higher degree of conductivity modulation and a lower forward voltage drop when turned on. Consequently, the investigation of thyristors is of great interest so long as adequate methods for providing forced gate turn-off can also be developed. As will be understood by one skilled in the art, a thyristor in its simplest form comprises a four-layer P1-N1-P2-N2 device with three P-N junctions in series: J1, J2, and J3, respectively. The four layers correspond to the anode (P1), the first base region (N1), the second base or P-base region (P2) and the cathode (N2), respectively. In the forward blocking state, the anode is biased positive with respect to the cathode and junctions J1 and J3 are forward biased and J2 is reversed-biased and most of the forward voltage drop occurs across the central junction J2. In the forward conducting state, all three junctions are forward biased and the voltage drop across the device is very low and approximately equal to the voltage drop across a single forward biased P-N junction.
An inherent limitation to the use of thyristors for high current applications is sustained latch-up, however, arising from the coupled P1-N1-P2 and N1-P2-N2 bipolar transistors which make up the four layers of the thyristor. This is because sustained thyristor latch-up can result in catastrophic device failure if the latched-up current is not otherwise sufficiently controlled by external circuitry or by reversing the anode potential. Sustained latch-up can occur, for example, when the summation of the current gains for the thyristor's regeneratively coupled P1-N1-P2 and wide base P1-N2-P2 transistors exceeds unity. An alternative to providing external circuitry or reversing the anode potential to obtain turn-off, however, is to use a MOS-gate for controlling turn-on and turn-off.
Several methods for obtaining MOS-gate control over thyristor action, including latch-up, exist. For example, in the MOS-controlled thyristor (MCT), turn-off is provided by shorting the emitter-base junction of the N-P-N transistor to thereby produce a reduction in gain. This form of control ideally raises the holding current of the thyristor to a level above the operating current level. Accordingly, an MCT structure has been reported which utilizes a P-channel MOSFET integrated into the cathode region of a thyristor for turn-off control, and an N-channel MOSFET integrated into the P-base region for turn-on control, as shown in FIG. 2. This device and its complementary counterpart are described in an article by V. A. K. Temple, entitled "The MOS Controlled Thyristor," published in IEDM Technology Digest, Abstract 10.7, pp. 282-285, (1984). However, the maximum controllable current density, which is a direct measure of a device's ability to turn-off, is limited by the MOSFET inversion-layer channel resistance and other resistances in the base region. Because of the lower mobility for holes in silicon, MCT's built from n-type high-voltage drift layers exhibit poor current turn-off characteristics.
Other examples of MOS-gated thyristors include the depletion-mode thyristor (DMT), shown in FIG. 3, which overcame many of the drawbacks associated with the MCT. In the DMT, a depletion-mode MOSFET is placed in series with the base of the P-N-P transistor. Accordingly, once the thyristor is turned-on, current flow can be shut off by application of a negative gate bias. This eliminates the base drive by pinching off the base current to the P-N-P transistor and shuts off the device.
Recently, a base resistance controlled thyristor (BRT) was described in U.S. Pat. No. 5,099,300, to inventor B. J. Baliga, and an article entitled "A New MOS-Gated Power Thyristor Structure with Turn-Off Achieved by Controlling the Base Resistance," by M. Nandakumar, inventor B. J. Baliga, M. Shekar, and S. Tandon and A. Reisman, IEEE Electron Device Letters, Vol. 12, No. 5, pp. 227-229, May, 1991, both of which are hereby incorporated herein by reference. The BRT operates by modulating the lateral P-base resistance of the thyristor using MOS gate control. Operational BRTs with 600-volt forward blocking capability, such as the one shown in FIG. 4, have been developed. FIG. 4 is a reproduction of FIG. 1 from the aforesaid Nandakumar, et al. article. The BRT can be turned-off by application of a negative bias to a P-channel enhancement-mode MOSFET to thereby reduce the resistance of the P-base by shunting majority charge carriers to the cathode. As will be understood by one skilled in the art, the reduction in P-base resistance results in an increase in the device's holding current to above the operational current level and shuts-off the device.
In another device, described in an article entitled "The MOS-Gated Emitter Switched Thyristor," by inventor B. J. Baliga, published in IEEE Electron Device Letters, Vol. 11, No. 2, pp. 75-77, February, 1990, turn-on is achieved by forcing the thyristor current to flow through an N-channel enhancement-mode MOSFET and floating N.sup.+ emitter integrated within the P-base region. This article is hereby incorporated herein by reference. A cross-sectional representation of this structure and equivalent circuit is shown in FIGS. 5A and 5B, which are reproductions of FIG. 1 from the aforesaid Baliga article. As will be understood by one skilled in the art, the length of the floating N.sup.+ emitter region, which determines the value of large resistance R shown in FIG. 5B, controls the holding and triggering current for the device. Turn-off of the emitter switched device (EST) is accomplished by reducing the gate voltage on the MOSFET to below the threshold voltage. This cuts off the floating N.sup.+ region from the cathode and ideally shuts-off the device.
Unfortunately, the integration of the MOSFET into the P-base region causes a parasitic thyristor to be formed, as shown in FIG. 5A, wherein the N.sup.+ source region of the N-channel MOSFET also comprises the N.sup.+ emitter of the vertical parasitic thyristor between the anode and cathode. If this thyristor turns-on, the EST can no longer be turned off by reducing the MOSFET gate voltage to zero. Turn-on of the parasitic thyristor is initiated by the onset of electron injection from the N.sup.+ emitter region of the parasitic thyristor when forward biased, and is dictated by the resistance of the P-base under the N.sup.+ emitter region. The likelihood that parasitic latch-up will occur can be reduced if the P-base resistance (small R) is lowered by making the length of the N.sup.+ emitter region small and by using a P.sup.+ diffusion to reduce the sheet resistance of the P-base. By keeping the resistance under the N.sup.+ emitter of the parasitic thyristor as small as possible, the likelihood that the P.sup.+ /N.sup.+ junction will become forward biased when the thyristor is turned-on is reduced. The likelihood of injection of electrons from the N.sup.+ emitter can also be reduced by shorting the P.sup.+ diffusion to the cathode, as shown. Notwithstanding these techniques to prevent latch-up, however, a multicell EST switching device rated for 1 amp has been shown to be susceptible to parasitic latch-up failure at about 2.5 amps for a gate voltage of 10 volts for a 600 volt device. This low latch-up level limits the suitability of using emitter switched devices for higher current applications.
Other attempts to limit the likelihood of sustained parasitic latch-up have been made. For example, in a related copending application entitled Emitter Switched Thyristor with Base Resistance Control, Ser. No. 07/897,456, filed Jun. 10, 1992, by M. S. Shekar, M. Nandakumar and inventor B. J. Baliga, the probability of sustained parasitic thyristor action preventing turn-off was reduced by incorporating a current diverting means adjacent the parasitic thyristor to thereby reduce the effective resistance of the second base region during turn-off and further inhibit latch-up by preventing the forward biasing of the P.sup.+ /N.sup.+ junction beneath the cathode.
Notwithstanding these attempts to limit the susceptibility to sustained parasitic thyristor latch-up, the presence of an adjacent parasitic thyristor between the anode and cathode poses a risk that under certain operating conditions, parasitic latch-up will occur.

Emitter switched thyristor with buried dielectric layer

North Carolina State University at Raleigh


A portable protective structure includes a framework made of corner connectors and various poles, such as vertical supports, horizontal supports and roof supports. Certain of the support poles may be made of telescopic tubes of circular cross-section joined together by spring locks in the inner tube projecting into arcuate slots in the outer tube. Pairs of poles, such as horizontal poles, may be connected to a corner connector by the use of a resilient cord extending through the connector with a spring clip on each end of the cord inserted into the horizontal pole. The roof may include a peak having four sets of extending walls into which each roof pole or eave may be connected with the opposite end of each roof pole inserted into a corner connector.

Various types of portable protective structures are known which generally include a framework made of vertical support poles mounted on the ground and secured at their upper ends to horizontal support poles. Roof poles are generally secured to the corners or intersections of the vertical and horizontal poles. The framework and particularly the roof is covered with a suitable cover material, such as canvas. Where the structure is used as a tent the cover would also extend generally to the ground.


Apparatus for mixing cementing material and mineral aggregate includes a container having a first chamber and a second chamber each having a top and a bottom. Cementing material is in the first chamber. Mineral aggregate is in the second chamber. An auger is attached to the bottom of the first and second chambers to receive and dispense cementing material from the first chamber and mineral aggregate from the second chamber. The mineral aggregate is dispensed at a rate different from that of the cementing material. The container includes extendable legs and is carried on a lift at the rear of a vehicle. The lift is raised to permit the container legs to be extended. After the legs are extended, the lift is lowered and the vehicle is driven away, leaving the container free-standing on its legs.

1. Field of the Invention
This invention relates to a system for transporting, dispensing, and mixing cementing material and mineral aggregate.
More particularly, the invention relates to apparatus which can simultaneously dispense cementing material and mineral aggregate at varying rates and which can mix the cementing material and mineral aggregate in varying proportions.
In another respect, the invention pertains to a system for transporting unmixed cementing material and mineral aggregate to a remote site.
2. Description of the Related Art Including Information Disclosed Under 37 C.F.R. Sections 1.97 and 1.00
Containers for dispensing totally mixed, ready-to-use mortar products and other cementing materials at a construction site are well known. For example, U.S. Pat. No. 4,956,821 to Fenelon discloses a silo from which a dry premixed mortar blend is dispensed. The silo described in the Fenelon patent has disadvantages. First, the Fenelon silo is made to be transported by a fork lift. Driving or transporting a fork lift to a construction site simply to erect the Fenelon silo often is undesirable because it increases personnel and other overhead costs. Second, once the Fenelon silo is on site, a forklift or crane is be utilized to charge the silo with 3000 pound bags of premixed mortar blend. This means that both the 3000 bags and the fork lift or crane must be transported to the construction site to charge the silo, again incurring additional labor and other overhead costs. Third, the Fenelon silo requires dry premixed mortar blend. Bags of premixed mortar are substantially more expensive than the bulk cement and sand utilized in preparing the dry mortar blend.
Accordingly, it would be highly desirable to provide a system which would deliver and dispense mixes of mortar and other cementing material at a construction site without requiring that a forklift, crane, and additional personnel be dedicated to assembling and filling a dispensing container. It also would be desirable to provide a system which would dispense mixes of mortar and other cementing materials without requiring the use of dry premixed blends of mortar or other cementing materials.
Therefore, it is a principal object of the invention to provide an improved system for dispensing blends of mortar and other cementing materials.
A further object of the invention is to provide apparatus which can, without requiring a crane or forklift to erect the apparatus at a construction site, be utilized to dispense blends of mortar and other cementing materials.
Another object of the invention is to provide apparatus which does not require the use of bags of dry premixed blends of cementing materials in order to dispense such cementing materials at a construction site.
Still a further object of the invention is to provide apparatus which can be utilized at a construction site to dispense different blends of cementing materials and mineral aggregate.

System for mixing cementing material and mineral aggregate


A system and method for automatic identification and recording of vehicles passing a road user charging point or location. A system and method for powering an on-board-unit (OBU) that can be mounted in a vehicle by including an energy harvester capable of providing at least a part of the energy required to operate the on-board-unit.

The disclosure is related to vehicle identification in general and particularly to systems and methods for automatic identification and recording of vehicles passing a road user charging point or location. More particularly the disclosure is related to an on-board-unit (OBU) that can be mounted in a vehicle and provides a novel solution to the powering of such on-board-units.
Systems for road user charging have been in operation on many locations around the world. Due to increasing congestion of roads and highways and the associated environmental influences, there is an increased focus all over the world on trying to implement regulations that may reduce the amount of vehicle traffic. Levying road user charges is an option, and automated systems for easy and effective payment of road user charges are commercially available today and are also under continuous development.
One way of identifying a car that is passing a road charging point is by equipping the cars with on-board-units (OBUs), each OBU being uniquely associated with a car in which the OBU is mounted and capable of signaling its presence to an appropriate reader unit (RU) which is coupled to associated roadside equipment (RSE) for further preparation and processing of the communication signals.
In a system provided by the Norwegian company Q-Free ASA any car carrying a Q-Free badge will be automatically identified when passing a road charging point equipped with corresponding Q-Free reader unit (RU) and roadside equipment. The Q-Free system ensures correct payment, for example by debiting a prepaid customer account, each time a vehicle passes a road charging point. The badge/OBU includes a transponder that is capable of receiving a transmitted signal from the reader unit coupled to the roadside equipment and for providing a response signal from the transponder to the RU. The response uniquely identifies the vehicle. Early generations of the Q-Free system used passive transponders that could operate without electric batteries locally in the OBUs.
Present systems for road user charging (RUC) may use transponders based on Dedicated Short Range Communication (DSRC) operating at signal frequencies in the 5.8 MHz band. They may be adapted to satisfy the recommendations of the CEN/TC 278 standardization work. Such transponders are mounted in the vehicles and they are generally referred to as on-board-units or OBUs in this description.
Active on-board-units are typically powered by an electrical battery, for example in the form of a lithium primary cell (3.6 V, 350-900 mAh). In normal operation such a battery provides for a minimum lifetime of five years for the badge. The lifetime may however be limited strongly by the number of passages under a reading unit, as well as by the number of undesirable wake-up processes due to radio signals in the surroundings, for example radar antennae, WLAN-equipment etc.
Present active OBU's are faced with numerous limitations. For example, even though the energy supply units may operate for quite some time, they typically have to be replaced after some time.
Their lifetime is also limited due to a limited energy supply, necessitating frequent changes of batteries or even replacement of the OBUs themselves. Moreover, the lifetime depends also on external influences, such as how often the OBU's become activated by signals other than the radio beacon at a road user charging point (undesirable wake-up processes).
Thus there is a continuous effort to provide OBUs that operate in more power efficient manners, and to provide batteries with improved energy storage capacity while not increasing the weight and size of the OBUs.
On this background, there is a recognized need for OBUs with increased lifetime, to avoid unnecessary replacement of the batteries of the OBU's or the complete OBU itself.

On-board-unit for use in vehicle identification


A fiber-reinforced composite composed of a B.sub.a O--Al.sub.2 O.sub.3 --2SiO.sub.2 (BAS) glass ceramic matrix is reinforced with CVD silicon carbide continuous fibers. A slurry of BAS glass powders is prepared and celsian seeds are added during ball melting. The slurry is cast into tapes which are cut to the proper size.. Continuous CVD-SiC fibers are formed into mats of the desired size. The matrix tapes and the fiber mats are alternately stacked in the proper orientation. This tape-mat stack is warm pressed to produce a "green" composite.. The "green" composite is then heated to an elevated temperature to burn out organic constituents. The remaining interim material is then hot pressed to form a silicon carbide fiber-reinforced celsian (BAS) glass-ceramic matrix composite which may be machined to size.

U.S. Pat. No. 3,985,532 to Grossman is directed to spontaneously formed celsian glass-ceramics. U.S. Pat. No. 4,589,900 to Brennan et al is concerned with a high strength thermally stable magnesium alumino silicate glass-ceramic matrix SiC fiber composite. This patent describes a means of producing (BaO--MgO).Al.sub.2 O.sub.3.SiO.sub.2 composite materials where a tape is formed on a drum, then cut into tapes which are used in a later process to build assemblies of different fiber orientations.
U.S. Pat. No. 4,755,489 to Chyung et al is concerned with reinforced calcium aluminosilicate glass-ceramics. U.S. Pat. No. 4,973,564 which likewise issued to Chyung et al is directed to bonding frits for ceramic composites.

Method of producing a ceramic fiber-reinforced glass-ceramic matrix composite

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


The disclosure relates to systems, methods and devices to provide race-condition true random number generator (TRNG) for soft intellectual property (IP) in field-programmable gate arrays (FPGAs). In an exemplary embodiment, a pair of long adder chains are raced against one another to complete a full cycle. Due to variances in the silicon, different chains will win each race at different times and thereby produce entropy. A calibration circuit can be used to set up the adder chains in an appropriate initial state to maximize the entropy produced. This structure has been found to be robust to layout changes, and the use of two such adder-chain-pairs reduces interference from other structures. Among others, the soft IP makes adding a robust TRNG to an FPGA much easier without concerns for how the structures are laid out or what other IP is nearby in the layout. The disclosed embodiments reduces the effort to add a TRNG to an FPGA design and improves the robustness of the TRNG making the design FIPS certifiable.

Despite years of active research, designing a robust digital random number generator on FPGA remains a challenge. Although ring oscillator is commonly deployed as entropy source on FPGA, ring-oscillator-based designs are generally vulnerable to frequency injection attack. Also, when multiple ring oscillators are used there is a tendency for the multiple ring oscillators to lock to each other.
True Random Number Generators (TRNGs) are susceptible to layout in silicon devices. Placement of Ring Oscillators (ROs) and other true random sources often have very different behaviors depending on the structures around them. Such behaviors create a problem when designers create Soft-IP libraries. A technical challenge has focused on how to make and/or place the TRNG in a way that permit production of acceptable random outputs. Additionally, there are national standards (commonly FIPS 140-2 and NIST SP 800-90A) that require specific structures and demand specific measurement and guarantees of random output. These challenges plague the conventional RNG designs.

System, method and apparatus for race-condition true random number generator


An oligonucleotide is intended to be used as a promoter non-template strand in the transcription of a sequence of a nucleotide target in the presence of a phage RNA polymerase. The phage RNA polymerase has specific natural promoters containing a consensus sequence from at least position -17 to position -1. The oligonucleotide contains a core sequence flanked at at least one of its ends by a nucleotide sequence capable of hybridization with a sequence of the target. The core sequence contains a sequence of 6 to 9 consecutive nucleotides from the region -12 to -4 of the non-template strand of the specific promoter, or a sufficiently homologous sequence to enable the functionality of the RNA polymerase to be retained. One flanking sequence is complementary to a first region of the target, and a second flanking sequence, when present, is complementary to a second region of the target, the first and second regions being separated on the target by a sequence having a number of nucleotides equal to the number of nucleotides in the core sequence. The number of nucleotides in the flanking region, or the sum of the number of nucleotides in the flanking regions, is at least sufficiently high for the nucleotide to be able to hybridize with the target at the temperature of use of the RNA polymerase. Such an oligonucleotide enables transcription to be initiated at a site of the target which is not normally a transcription start site for the RNA polymerase.

The present invention relates to a modified promoter for RNA polymerase and to its applications. More especially, it relates to the use of a promoter for phage RNA polymerases, this promoter being modified relative to the promoters present in nature or which have already been described. It has been discovered that it is possible to reduce the size of the promoter sequence and to integrate mispairings between the two strands of the promoter. The modified promoters obtained according to the invention make it possible, in particular, to effect the transcription of a nucleotide target from a site which is not normally a transcription start site for the RNA polymerase used. By means of the invention, it becomes possible to transcribe in vitro a wide diversity of sequences which are not transcribed by phage RNA polymerases when the wild-type promoters (that is to say the natural promoters) of the said RNA polymerases are used. The use of these modified promoters makes it possible, furthermore, to obtain different efficiencies of initiation of transcription for the differential transcription of several sequences within a same reaction medium.
RNA (ribonucleic acid) is known to be the transcription product of a molecule of DNA (deoxyribonucleic acid) synthesized under the action of an enzyme, DNA-dependent RNA polymerase.
It is advantageous in several respects to be able to obtain several RNA sequences from a DNA sequence. Different applications of the obtaining of specific RNA sequences have already been described, such as, for example, the synthesis of RNA probes or of oligoribonucleotides (see, in particular, Milligan, J. F., Groebe, D. R., Witherell, G. W. and Uhlenbeck, O. C. (1987) Nucleic Acids Res. 25, 8783-8798), or the expression of genes (see, in particular, Steen, R. et al. (1986) EMBO J. 5, 1099-1103 and Fuerst, T. R. et al. (1987) Molecular and Cellular Probes 7, 2538-2544 and Patent Applications WO 91/05,866 and EP 0,178,863), or alternatively gene amplification as described by Kievits, T. et al. (Journal of Virological Methods 35, 273-286 (1991)) and Kwoh, D. Y. et al. (Proc. Natl. Acad. Sci. USA 86, 1173-1177 (1989)) or in Patent Applications WO 88/10,315 and WO 91/02,818.
One of the distinctive features of DNA-dependent RNA polymerases is that of initiating RNA synthesis according to a DNA template from a particular start site as a result of the recognition of a nucleic acid sequence, termed promoter, which makes it possible to define the precise localization and the strand on which initiation is to be effected. Contrary to DNA-dependent DNA polymerases, polymerization by DNA-dependent RNA polymerases is not initiated from a 3'-OH end, and their natural substrate is an intact DNA double strand.
A few generic terms which will be employed are defined below.
Oligonucleotide or polynucleotide is understood to mean nucleotide sequences containing the natural bases (A, C, G, T, U) and/or one or more modified bases such as inosine, 5-methyldeoxycytidine, deoxyuridine, 5-(dimethylamino)deoxyuridine, 2,6-diaminopurine, 5-bromodeoxyuridine or all modified bases permitting hybridization, especially those modified by all suitable chemical modifications enabling the hybridization yield to be increased. Examples of such modifications are, in particular, the introduction between at least two nucleotides of a group chosen from diphosphate, alkyl-and/or arylphosphonate and/or phosphorothioate esters, or the replacement of at least one sugar (ribose or deoxyribose) by a polyamide; see, for example, Nielsen, P. E. et al., Science, 254, 1497-1500 (1991). The term "nucleotide" or "base" denotes not only a natural deoxyribonucleotide or ribonucleotide, but any nucleotide modified as has just been mentioned.
Promoter is understood to mean any nucleic acid sequence capable of being recognized by an RNA polymerase to initiate transcription, that is to say the synthesis of an RNA. This RNA polymerase can be either DNA-dependent or RNA-dependent.
Natural promoter is understood to mean the promoter sequences present in the genome, coding for the RNA polymerase for which this promoter is specific. Promoter sequence is understood to mean the sequence of an oligonucleotide which participates in the composition of one of the strands of the promoter.
Transcription is understood to mean the neosynthesis of several RNA strands complementary to the sequence (or target) which is under the control of the promoter, the promoter permitting initiation of this reaction. This sequence is in general adjacent to the 5' end of the template strand of the promoter. The RNA strands synthesized are termed transcripts.
Differential transcription is understood to mean a transcription giving different numbers of transcripts from different templates.
Mutation is understood to mean any change in sequence relative to the natural sequence. The mutation can affect both complementary bases positioned on each strand of a nucleic acid duplex, or affect only one of them. If the mutation affects only one of the two complementary bases, it gives rise to the appearance of what is called a mispairing.
Mispairing is understood to mean the introduction within a nucleic acid double strand of pairs of bases other than A:T, C:G or A:U.
Non-pairing is understood to mean the presence of nucleotides which are not paired with a base of the complementary nucleic acid strand, by virtue of their nature or by virtue of their position in the sequence. If several bases of the same strand are unpaired, they can form bonds with one another which can cause the appearance of secondary structures termed "loops" or "stem-loops".
Deletion is understood to mean the removal of some nucleotides from a sequence. A deletion can affect only one base, or several adjacent bases. If several non-adjacent bases are affected, this will be referred to as multiple deletions. On a double-stranded nucleic acid, a deletion generally affects, together, both complementary bases positioned on each nucleic acid strand. However, a deletion can also take place only on one or several bases of only one strand, and cause non-pairings.
Consensus sequence is understood to mean a theoretical nucleotide sequence in which the nucleotide at each site is the one which appears most commonly at this site in the different natural forms of the genetic element in question (for example the promoter). The term "consensus" also denotes any actual sequence very closely similar to the theoretical consensus sequence.
It will be recalled that transcription takes place by synthesis, in the 5'.fwdarw.3' direction, of an antiparallel RNA complementary to the nucleotide strand transcribed (termed "template strand" or "antisense strand"). The DNA strand which is complementary to the transcribed strand is termed "non-template strand" or "sense strand". By convention, the nucleotide from which transcription starts is designated +1 (or simply 1). On the template strand, the successive nucleotides located beside the 3' end (upstream region) are, starting from +1, numbered -1, -2, and the like. A downstream region relative to a given nucleotide (or to a given sequence) is located towards the 5' end of the template strand, and hence towards the 3' end of the RNA strand synthesized. Starting from +1, nucleotides downstream correspond successively to positions +2, +3, and the like.
Compared to bacterial, eukaryotic or mitochondrial RNA polymerases, phage RNA polymerases are very simple enzymes. Among these, the best known are the RNA polymerases of bacteriophages T7, T3 and SP6. Bacteriophage T7 RNA polymerase has been cloned (see, in particular, U.S. Pat. No. 4,952,496). These enzymes are very homologous with one another, and are composed of a single subunit of 98 to 100 kDa. Two other phage polymerases share these homologies: that of Klebsiella phage K11 and that of phage BA14; see Diaz et al., J. Mol. Biol. 229: 805-811 (1993).
The natural promoters specific for the RNA polymerases of phages T7, T3 and SP6 are well known. Sequencing of the whole bacteriophage T7 genome in 1983 by Dunn et al. (J. Mol. Biol. 166, 477-535 (1983)) enabled the existence of 17 promoters to be defined on this DNA, these being shown in Table 1 below (non-template strand).
TABLE 1 __________________________________________________________________________ Promoters for T7 RNA polymerase Promoter Nucleotide __________________________________________________________________________ -101 Conserved sequence TAATACGACTCACTATAGGGAGA (SEQ ID NO:10) Replication promoter -20 -101 . .. .phi.OL TTGTCTTTAT TAATACAACTCACTATAAGGAGA GA (SEQ ID NO:11) Class II promoters -20 -101 . .. .phi.1-1A AACGCCAAAT CAATACGACTCACTATAGAGGGA CA (SEQ ID NO:12) .phi.1-1B TTCTTCCGGT TAATACGACTCACTATAGGAGGA CC (SEQ ID NO:13) .phi.1-3 GGACTGGAAG TAATACGACTCAGTATAGGGACA AT (SEQ ID NO:14) .phi.1-5 AGTTAACTGG TAATACGACTCACTAAAGGAGGT AC (SEQ ID NO:15) .phi.1-6 TGGTCACGCT TAATACGACTCACTAAAGGAGAC AC (SEQ ID NO:16) .phi.2-5 AGCACCGAAG TAATACGACTCACTATTAGGGAA GA (SEQ ID NO:17) .phi.3-8 CGTGGATAAT TAATTGAACTCACTATTAGGGAA GA (SEQ ID NO:18) .phi.4c CCGACTGAGA CAATCCGACTCACTAAAGAGAGA GA (SEQ ID NO:19) .phi.4-3 AGTCCCATTC TAATACGACTCACTAAAGGAGAG AC (SEQ ID NO:20) .phi.4-7 TTCATGAATA CTATTCGACTCACTATAGGAGAT AT (SEQ ID NO:21) Class III promoters -20 -101 . .. .phi.6-5 GTCCCTAAAT TAATACGACTCACTATAGGGAGA TA (SEQ ID NO:22) .phi.9 GCCGGGAATT TAATACGACTCACTATAGGGAGA CC (SEQ ID NO:23) .phi.10 ACTTCGAAAT TAATACGACTCACTATAGGGAGA CC (SEQ ID NO:24) .phi.13 GGCTCGAAAT TAATACGACTCACTATAGGGAGA AC (SEQ ID NO:25) .phi.17 GCGTACCAAA TAATACGACTCACTATAGGGAGA GG (SEQ ID NO:26) Replication promoter -20 -101 . .. .phi.OR CACGATAAAT TAATACGACTCACTATAGGGAGA GG (SEQ ID NO:27) __________________________________________________________________________
As is apparent from the above table, twenty-three adjacent nucleotides located between positions -17 and +6 relative to the transcription start site (position 1) are highly conserved. These nucleotides are even identical in the 5 class III promoters, which are the most efficient in vivo and in vitro. Among the 11 different promoters, the majority diverge in respect of the nucleotides lying between positions +3 and +6. Among the nucleotides lying between positions -16 and -1, nine are completely conserved, and four others are conserved in 16 promoters. These findings suggest that these 13 nucleotides are important factors in the definition of a promoter. These conclusions have been confirmed by demonstrating the efficacy of a promoter after cleavage of the DNA upstream of position -21 (Osterman, H. L. et al. (1981) Biochemistry 20, 4884-4892) and -17 (Martin, C. T. et al. (1987) Biochemistry 26, 2690-2696). In contrast, these same publications show that a cleavage upstream of -10 or -12 abolishes this efficacy.
Phage T3 RNA polymerase is almost as well known as T7 RNA polymerase. These two enzymes have a very similar structure (80% identity) (McGraw, N. J. et al. (1985) Nucleic Acids Res. 13, 6753-6766), but possess, however, an almost absolute template specificity. The sequences of 11 promoters specific for T3 RNA polymerase have been determined and are presented in Table 2 below (non-template strand).
TABLE 2 __________________________________________________________________________ Promoters for T3 RNA polymerase Promoter Nucleotide __________________________________________________________________________ -20 -101 .. Conserved sequence TATTAACCCTCACTAAAGGGAGA (SEQ ID NO:28) -20 -101 .. GTC TATTTACCCTCACTAAAGGGAAT AAGG (SEQ ID NO:29) TAG CATTAACCCTCACTAACGGGAGA CTAC (SEQ ID NO:30) TAC AGTTAACCCTGACTAACGGGAGA GTTA (SEQ ID NO:31) AAG TAATAACCCTCACTAACAGGAGA ATCC (SEQ ID NO:32) GGG CATTAACCCTCACTAACAGGAGA CACA (SEQ ID NO:33) GCC TAATTACCCTCACTAAAGGGAAC AACC (SEQ ID NO:34) TAC AATTAACCCTCACTAAAGGGAAG AGGG (SEQ ID NO:35) TCT AATTAACCCTCACTAAAGGGAGA GACC (SEQ ID NO:36) ACC TAATTACCCTCACTAAAGGGAGA CCTC (SEQ ID NO:37) GTG AATTAACCCTCACTAAAGGGAGA CACT (SEQ ID NO:38) TTG CATTAACCCTCACTAAAGGGAGA GAGG (SEQ ID NO:39) __________________________________________________________________________
At the present time, 4 different sequences of promoters for phage SP6 RNA polymerase have been demonstrated by Brown, J. E., et al. (Nucleic Acids Res. 14, 3521-3526) (1986)). Phage SP6 RNA polymerase also displays many similarities with phage T7 RNA polymerase. These sequences are presented in Table 3 below (non-template strand).
TABLE 3 __________________________________________________________________________ Promoters for SP6 RNA polymerase Promoter Nucleotide __________________________________________________________________________ -101 .. Conserved sequence ATTTAGGTGACACTATAGAAGGG (SEQ ID NO:40) -20 -101 . .. pSF64 ACACATACG ATTTAGGTGACACTATAGAATAC AA (SEQ ID NO:41) pJEB1 TAATTGCCT ATTTAGGTGACACTATAGAAGGG AG (SEQ ID NO:42) pJEB4 GGACTTGGT AATTAGGGGACACTATAGAAGGA GG (SEQ ID NO:43) pJEB6 GTGTCTCTT ATTTAGGGGACACTATAGAAGAG AG (SEQ ID NO:44) __________________________________________________________________________
As is the case for T7 RNA polymerase, the sequences of the promoters for T3 RNA polymerase and for SP6 RNA polymerase are very similar, in particular between positions -17 and +6. Comparison of the sequences of these three promoters (FIG. 1) shows the existence of a common sequence from position -7 to -3; see in this connection, in particular: Brown, J. E. et al., Nucleic Acid Res., 14, 3521-3526 (1986) and Bailey et al., Proc. Natl. Acad. Sci. USA 80: 2814-2818 (1983).
Hence it is possible to consider that the various phage RNA polymerases studied above belong to a family of RNA polymerases which recognize promoters possessing a consensus sequence from position -17 to position +6, and in particular from -17 to -1.
To obtain the RNA corresponding to a given DNA sequence through the action of an RNA polymerase, it is necessary to place this sequence under the control of the promoter of this RNA polymerase. This is the so-called step of installation of a promoter, immediately upstream of the sequence to be transcribed. This installation in the present state of the art requires the use of laborious methods.
The most traditional method of installation of a promoter is the cloning of the sequence to be transcribed into a vector containing a promoter for a phage RNA polymerase upstream of a cloning site. Several vectors of this type are on the market, such as, for example, pT3/T7-LUC (Clontech Laboratories Inc.), or Lambda ZAP II, Uni-ZAP XR, Lambda DASH II, Lambda FIX II, pWE 15 and SuperCos cosmid (Stratagene Cloning System), or pT7-0, pT71 or pT7-2 (United States Biochemical) or alternatively pT7/T3a-18 or pT7/T3a-19 (GIBCO BRL), or are described in publications, such as the pET vectors (Rosenberg, A. H. et al., Gene 56, 125-135 (1987)). After the DNA fragment to be cloned has been obtained and inserted into the vector, and the vector has been amplified, transcription may be effected. This method enables any sequence to be transcribed. However, it is very laborious, and not every kind of end can be obtained on the RNA in this way, since the localization of this end is imposed by the enzyme restriction site used for the cloning.
Some known methods for the in vitro synthesis of oligoribonucleotides require the synthesis by chemical means of two complementary oligodeoxynucleotides comprising a promoter for a phage RNA polymerase. It has been demonstrated (Milligan et al., paper cited) that a partially single-stranded template which is double-stranded only on the promoter sequence, from position +1 to -14, is as active in transcription as a double-stranded template. Thus, the method requires the synthesis of a 15-mer nucleotide comprising the sequence of the non-template strand of a phage promoter from position -14 to +1, and of a second oligonucleotide containing at its 3' end the sequence complementary to the first oligonucleotide, and on its 5' region the sequence complementary to the oligoribonucleotide which it is desired to synthesize. Since chemical synthesis does not enable oligonucleotides of good quality to be obtained if their size is larger than 70 bases, this technique is not applicable for oligoribonucleotides of more than 55 bases if the promoter sequences already described are used. Furthermore, the method requires exact knowledge of the RNA sequence which it is desired to synthesize.
Another method of installation of a promoter on a sequence, by ligation, is possible (Leary, S. et al., Gene 106, 93-96 (1991)) if this sequence possesses a well-defined 3' end. It comprises the hybridization with this 3' end of an oligonucleotide carrying the sequence of the non-template strand of the promoter, followed by the sequence complementary to the 3' end of the target sequence, over a sufficient length to permit hybridization. A second oligonucleotide is involved, the sequence of which is complementary to the promoter region of the first oligonucleotide, and which carries a phosphate group at the 5' end. Hybridization of these two oligonucleotides and the target brings the 5'-phosphate end of the oligonucleotide carrying the sequence of the template strand of the promoter into contact with the 3'-OH end of the target. Through the action of a ligase, a phosphodiester link between these two ends is established, permitting the formation of a complex in which the target is under the control of the promoter.
The appearance of the "polymerase chain reaction" (PCR) technique has made possible the creation of new, more efficacious methods for installing a promoter. The transcription template is synthesized by PCR. The upstream primer supplies the promoter for the phage RNA polymerase and defines the 5' end of the transcription product (or transcript), while the downstream primer defines the 3' end of the amplified DNA and of the transcript. This technique enables an RNA of any size and with any 3' end to be obtained.
The installation of a phage promoter by means of a reaction modelled on the cycle of retroviruses is possible from an RNA (Kwoh, D. Y. et al., P.N.A.S. USA, 86, 1173-1177 (1989)). An upstream primer carrying the sequence of the promoter is used to synthesize the DNA complementary to the RNA by means of a reverse transcriptase. The RNA of the RNA:DNA duplex thereby formed is digested with RNaseH. The single-stranded DNA thus liberated hybridizes with the second primer which, by means of the reverse transcriptase, enables the second complementary DNA strand to be synthesized. However, this first step does not enable the 3' end of the RNA to be defined. It is the second synthesis, with the same enzymes and by the same method, of a second generation of template for the phage RNA, from the first transcripts obtained, which enables a 3' end to be obtained which is strictly defined by the second primer used.

Modified promoter for RNA polymerase, its preparation and its applications


Methods, systems, and apparatus, including computer program products, for distributed security system authorization. Client device authentication instructions are executed on a client device to determine if authentication data accessible by the client device authentication instructions are stored at the client device. If the authentication data are stored at the client device, the client device authentication instructions generate authenticated user data and store the authenticated user data at the client device. If the authentication data are not stored at the client device, the client device authentication instructions generate a login environment that allows a user of the client device to input login data. The login data are provided to a verification process that in response to verification provide the authentication data to the client device.

This disclosure relates to security provisioning.
The prevalence and accessibility of computer networks requires security measures to protect valuable information. An enterprise that implements the security system can require a user to be authenticated and authorized before using the network.
One way of tracking an authentication status of a client device is to use cookies. Cookies allow a state to be maintained in a client browser, but are limited to domains for which the cookie is defined. Additionally, cookies for a specific browser are stored in a browser specific location for the browser. Thus, if a client device has more than one browser, the authenticated state in one browser is not conveyed to the other browsers.
Additionally, to provide the cookies through the HTTP mechanism, it is necessary to create authorization cookies for every new domain that is visited by the user, and to create an initial authentication cookie. Propagation of the initial authentication cookie and the domain authorization cookies for each domain may involve a number of HTTP redirects. It is desirable to minimize the number of redirects.

User authentication and authorization in distributed security system