A method according to one embodiment may include discovering, at least in part, by an integrated circuit of at least one communication protocol via which at least one device external to the integrated circuit is capable of communicating. In this embodiment, the integrated circuit may be capable of communicating in accordance with a plurality of different communication protocols. The method according to this embodiment may also include selecting, at least in part, by the integrated circuit of the at least one communication protocol to use to communicate with the at least one device. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

In one conventional data storage arrangement, a computer node includes a host bus adapter (HBA). The HBA communicates with a data storage system via one or more communication links using a communication protocol associated with the one or more links. Typically, the HBA includes a plurality of integrated circuit chips to carry out communications between the HBA and the data storage system, and is capable of using only a single predetermined communication protocol to communicate with the data storage system. Thus, for example, in this conventional arrangement, if the data storage system is incapable of communicating with the HBA using this predetermined protocol, one or more external communication protocol converters, translators, and/or expanders may be coupled between the HBA and data storage system to permit communication between the HBA and data storage system.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly, and be defined only as set forth in the accompanying claims.

Integrated circuit capable of communicating using different communication protocols


An evaporative emission tester is used to evaluate the integrity of a vehicle's evaporative emission control system, including determining the system's purge capability. The emission tester performs a purge flow test to determine whether fuel vapor stored in the vehicle's evaporative canister and present in the fuel tank is being drawn into the engine for combustion at a minimum amount. The emission tester also performs a pressure test of the vehicle's evaporative canister purge system, which includes the fuel tank and lines. The emission tester can function as a stand-alone unit or as an integrated product with a host computer.

1. Field of the Invention
The present invention relates generally to a device and method for diagnosing an evaporative emission control system of an internal combustion engine.
2. Description of the Prior Art
The Environmental Protection Agency (EPA), in a cooperative effort with individual states, automobile manufacturers, manufacturers and contractors of test/diagnostic equipment, develops test procedures and related requirements for use in thoroughly diagnosing the emission systems of motor vehicles. The need for stricter emission system tests, as well as diagnostic instruments to implement such tests, is brought on by the promulgation of newly enacted environmental laws, both federal and state, relating to vehicle emissions. The test procedures and test equipment to be developed to perform the EPA tests reflect a desire by the EPA that sufficient safeguards be in place to prevent false failures, as well as a desire to see enough flexibility in the equipment specifications and quality control requirements to allow for innovative technical approaches to reduce overall costs. These tests are intended to identify a vehicle's true emissions as well as whether the vehicle needs emission repairs. If repairs are needed, the devices used for the tests can be used to ensure that the vehicles are repaired to be in conformance with the requirements.
Since 1971, fuel tanks on cars have been designed as part of a closed system in which vapors that evaporate from the gasoline in the tank are not released into the atmosphere. The system is called an evaporative emission control system and is sealed and under pressure, so that excess vapors are shunted to a charcoal canister known as the evaporative canister. Recent EPA rules require that vehicles pass a purge flow test of the evaporative canister as well as a test that monitors whether pressure in the system is maintained.
The evaporative system purge test is used to determine whether fuel vapor stored in the evaporative canister and present in the fuel tank are being properly drawn into the engine for combustion while the car is being driven. The evaporative emission system uses engine vacuum to draw fuel vapors in the fuel tank, and those temporarily stored in the evaporative canister and attached hoses, into the engine for combustion. The purge flow test determines whether this system is functioning properly by measuring the flow of vapors into a running engine. The pressure test, on the other hand, checks the system for leaks that would allow fuel vapors to escape into the atmosphere.
The purge flow test is generally conducted by driving the vehicle onto a dynamometer, activating vehicle restraints, positioning an exhaust collection device, and positioning an auxiliary engine cooling fan to simulate normal driving conditions. When the purge system is not working properly, the evaporative system can become plugged or perforated or disconnected, resulting in lack of flow to the intake manifold or leaking of hydrocarbons into the atmosphere. In addition to causing hydrocarbon emissions, failure of the purge flow system reduces fuel economy. During the purge flow test, purge flow is measured by simply inserting a flow sensor apparatus at one end of the hose that runs between the evaporative canister and the engine. At present time, EPA rules require that a vehicle have a minimum of 1 liter of flow during a 240-second test in order to pass. Most cars in proper working order will accumulate as much as 25 liters in a minute test cycle, and as much as 100-plus liters over a four-minute transient cycle. As soon as a vehicle exceeds 1 liter of flow, the purge test is complete.
The purge test requires a flow sensor apparatus that can measure the total flow observed over a given transient cycle. Additionally, hoses and universal fittings are required to hook up the flow sensor apparatus. Finally, a metering device is needed to control the test process, collect and record the data, and determine the pass/fail status.
The pressure test monitors for pressure leaks in the system. To check a system for leaks, the vapor lines to the fuel tank, and the fuel tank itself must be filled with nitrogen to a pressure of 14 inches of water (about 0.5 psi), in accordance with present EPA specifications. To pressurize these components, the inspector must locate the evaporative canister, remove the vapor line from the fuel tank near the canister, and hook up the pressure test equipment to the vapor line. After the system is filled, the pressure supply system is closed off, and the drop in pressure is observed. If the system pressure remains above eight inches of water after two minutes, the vehicle passes the test.
A source of nitrogen, a pressure gauge, a valve, and associated hoses and fittings are needed to perform the pressure test. In addition, a metering device is used to automatically meter the nitrogen, monitor the pressure, and collect and process the results. The EPA wants the pressure test performed in less than two minutes on most vehicles. Hence, algorithms must be developed to optimize the test so that a pass/fail decision can be made in less than two minutes.
A number of different devices have been developed to diagnose the purge flow and pressure systems of vehicles. Many of these devices are onboard evaporative emission control devices, permanently coupled to the engine's control module (ECM) to monitor system integrity.
One type of pressure test device is disclosed in U.S. Pat. No. 5,201,212 to Williams, relating to a line leak detector for detecting leaks in underground lines using pressurized nitrogen. A line supplies the pressurized nitrogen, at constant pressure, to the leak tester computation unit and instrument package that supplies the system under test through another line. Selected test system parameters are entered into the instrumentation package prior to running the test. The nitrogen pressure is applied and, during the test, the temperature of the tank and pressure is sampled and the leak rates are compensated for volumetric changes due to temperature.
Similarly, U.S. Pat. No. 5,086,403 to Slocum et al. discloses a microprocessor-based tester that measures the time rate of change of pressure to determine leaks. A leak detector is disclosed therein for a gasoline dispensing system and includes a central monitor and a test probe. The probe has a microprocessor and pressure transducer. The program of the microprocessor considers the pressure versus time signature of the pump system and can compensate for air in the lines and provide gross and precision tests for leaks.
U.S. Pat. No. 5,239,858 to Rogers et al. discloses a method and apparatus for automated testing of a vehicle fuel evaporation control system using an inert gas, such as helium. The system is tested by introducing the inert gas supplied from a cylinder through a pressure regulator and flow sensor apparatus to the fuel filler by use of a cap. The inert gas, helium, introduced to the fuel tank is vented through the system to the vehicle's evaporative canister where it is not absorbed, so it is vented out its perforated bottom and is sensed by a detector, confirming system integrity between the canister and the fuel tank. Starting the engine provides for the inert gas to be drawn from the canister into the engine. The absence of helium at the canister with the engine running would verify operation of the purge system. The helium drawn into the intake manifold would pass through the engine and catalytic converter, and appear in the tailpipe. The mass of helium exiting the tailpipe should equal the mass entering the system through a filler line. Any loss represents leakage in the system.
Conventional pressure testers, such as those described above, depend on constant flow pressurization techniques which are fundamentally inadequate for two reasons. First, a pressurizing scheme based on constant flow pressurization takes a prohibitively long time to perform. Second, the use of a constant flow pressurization technique does not lend itself to practical application in pressure testing of an evaporative emission control system. The high level pressurization requirements, as defined by EPA specifications, demand nitrogen pressurization to levels as high as 0.5 psi in a very short time frame.
Likewise, conventional purge testers operate to detect the proper functioning of a vehicle purge system as accomplished at various time intervals and at known rates of flow. To date, none of the modern-day purge testers are capable of measuring rates of fuel flow in the range of zero to 60 liters/minute as required by the EPA.
The EPA now requires that purge flow be detected for values as low as 1 liter over a four minute time cycle. This is equivalent to an average flow rate of 0.25 liters/minute. Conventional purge flow testers are incapable of measuring fuel vapor flow rate at such low levels.
Furthermore, there has never been a single, self-contained, portable, evaporative emission tester capable of performing both purge flow and pressure testing.


A general complex structure graph constructing method and the associated computer program is described. The generators and initiators selected by the user are used as the geometrical graphing basis. Using the transformation information of the generators and the operation information between the generators and the initiators, the geometrical transformation and duplication of the objects are performed according to the definitions of duplication objects and connecting objects. This implements the geometrical graphing of complex structures. It is characterized in that: the operations are performed in a visualized way, including graphing operations (e.g., generation of objects), parameter transmissions (e.g., shifted duplications), and data generation (e.g., generation of a geometrical graph). Since the operations are simple and can be implemented on all computer executable platforms and is suitable for artistic designs, graphing, and teaching.

1. Field of Invention
The invention relates to a method for constructing a complex structure graph and related computer program, and more particularly, to a method for constructing a complex structure graph and related computer program that can be implemented on computer executable platforms to generate geometrical graphs using the transformation information of generators and the operation information between the generators and the initiator.
2. Related Art
Traditionally, the generation of a complex graph mostly relies on manual graphing or some professional graphing software, such as AutoCAD, Flash, PhotoShop, Illustrator, CorelDraw, and Visio. Even though manual graphing can overcome all sorts of complex structure graphing, it often requires a lot of time to accomplish. Also, the precision of manual graphing cannot achieve a certain standard. As to the professional graphing software, although all such programs provide some special graphing tools to rapidly and precisely make complex graphs, they are still limited by their intrinsic orientations in graphing. Therefore, one often has to select from these programs to get one that is suitable for his or her professional needs.
In fact, there are many special and complex patterns in the field of complex structure graphing. For example, the fractals are patterns formed with a huge amount of similar elements. If one wants to draw such kinds of graphs by hand, it is simply a waste of time and the precision is unsatisfactory. If one wants to use some professional graphing software to do the job, it is often limited by the tools provided by the program and the user has very limited freedom in graphing. Although there are other professional software that can build mathematical models, such as MatLab, Mathematica, and GSP, for people to construct the above-mentioned complex geometrical graphs, these professional programs require a lot of training and are not suitable for normal users.
Other applications such as Mathlet used in web page designs have only dedicated functions and their development standards are not completely settled yet. Therefore, they are even less popular.
In fact, to plot a complex structure graph based on the above-mentioned geometrical structure can be done by first analyzing the structure of the whole structure. One then selects a corresponding duplication rules according to the structure. Such complex structure graphs can then be generated by repeated duplications. Take the fractals as an example, some commonly seen complex structure graphs in nature, such as flowers, grass, trees, mountains, rocks, waves, stars, clouds, lightning, snowflakes, etc belong to this category. Their basic structures can be described using fractals. Basically, the fractals have the properties of self-similarity, symmetry, and self-affinity. If these ideas can be implemented by the invention, it is then an easy job to make any complex structure graph.
However, all the related programs on computer executable platforms have very little compatibility. Visually, it is still very difficult to precisely select geometrical objects in a complex structure using a pointing device (e.g., the mouse). Moreover, when there are too many objects to be selected, it is often hard to provide an efficient selection tool. Therefore, such a task becomes very time-consuming. The positioning and various operations (e.g., rotation, moving, zooming) for the geometrical objects cannot be easily done by purely manual operations.
To simplify the graphing with a complex structure and to increase the freedom in manipulations for a wider range of users, it is necessary to provide a better general structure that can be implemented on all computer executable platforms and other application programs. Therefore, the threshold of making complex structure graphs can be lowered.

Method and computer program for constructing complex structure graphic


A semiconductor device comprises an AlN layer, a GaN layer, and an AlGaN layer sequentially formed on a semiconductor substrate. A first opening extends through said GaN layer and said AlGaN layer and exposes part of an upper surface of the AlN layer. A second opening extends through the semiconductor substrate and exposes a part of a lower surface of the AlN layer, in a location facing the first opening. A upper electrode is exposed on an upper surface of the AlN layer in the first opening; and a lower electrode is disposed on a lower surface of the AlN layer in the second opening.

1. Field of the Invention
The present invention relates to a semiconductor device wherein the laminated structure of nitride semiconductors is formed, and more specifically, to a semiconductor device that can ensure sufficient capacitance and withstand voltage without enlarging a chip area.
2. Background Art
A nitride semiconductor is the generic term for gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InM), and mixed crystals composed of these nitrides. Generally, the nitride semiconductor is mechanically robust and chemically stable, and has high thermal conductivity and excellent heat dissipation properties. Therefore, a semiconductor element fabricated using a nitride semiconductor multilayer film structure, for example, an AlxGa1-xN/GaN high electron mobility transistor (HEMT) is considered to be applied to a high output high-frequency element. Therefore, a large number of trial products of AlGaN/GaN HEMTs have been reported.
A circuit using an AlGaN/GaN HEMT can be used as a monolithic microwave integrated circuit (MMIC) in the same way as other high-frequency transistors. For fabricating an MMIC, the structure and the fabricating method of passive elements, such as a resistor, an inductor, and a capacitor, other than transistors are important. In conventional metal insulator metal (MIM) capacitors, a silicon nitride (SiNx) film is deposited on an underlying metal layer by a chemical gas-phase growing method, and is used as an insulating film.
The breakdown electric field of the SiNx film is not more than about 6 MV/cm (for example, refer to N. Inoue, Ippei Kume, Jun Kawahara, Shinobu Saito, Naoya Furutake, Takeshi Toda, Koichiro Matsui, Takayuki Iwaki, Masayuki Furumiya, Toshiki Shinmura, Koichi Ohto, and Yoshihiro Hayashi, Jpn. J. Appl. Phys. 46, 1968 (2007)). Therefore, the breakdown voltage of an MIM capacitor using a normal SiNx film of a thickness of 150 nm is about 90 V, and is insufficient for withstanding voltage as a capacitor for the MMIC of an AlGaN/GaN HEMT. When the SiNx film is thickened in order to make the break down voltage higher, the capacitance is lowered in proportional to the film thickness; therefore, the area of the capacitor must be enlarged. If the sufficient capacitance and withstand voltage are to be ensured, a problem of enlarged chip area is caused.


An antenna structure includes a feed portion, a ground portion, a first radiating body, a second radiating body and a third radiating body. The first radiating body is connected to the feed portion and configured to obtain a first resonance frequency band. The second radiating body is connected to the feed portion. The third radiating body includes a first connection section connected the ground end, a second connection section, and a third connection section perpendicularly connected between the first connection section and the second connection section. The first connection section and the second connection section are positioned at two opposite sides of the second radiating body so that the third radiating body and the second radiating body cooperatively obtain a second resonance frequency band.

1. Technical Field
The disclosure generally relates antenna structures and particularly to an antenna structure having a wider bandwidth and a wireless communication device using the antenna structure.
2. Description of Related Art
To communicate in multi-band communication systems, a bandwidth of an antenna of a wireless communication device such as a mobile phone should be wide enough to cover frequency bands of the multi-band communication systems. In addition, because of the miniaturization of the wireless communication device, space occupied by the antenna is compressed and limited. Therefore, it is necessary to design the antenna to have the wider bandwidth within the compressed and limited space.
Therefore, there is room for improvement within the art.

Antenna structure and wireless communication device using the same


A moldable composite with high heat resistance and noise absorption properties utilizes nonwoven fabrics and a heat resistance additive. The composition that provides both superior acoustic performance and excellent flex modulus that may be utilized in automotive products and applications in interior and exterior structures. A blowing agent may be utilized to create micro porous cells in a polymer non-woven structure. The cells or voids make the material lighter and allow the material to have superior acoustic properties that are useful in automotive applications.

The need for higher performance materials in the automotive industry has increased more than ever in past decades Improved technology has produced cars that not only drive faster and more economical but also have more electronic options such as in multimedia devices. Once where an auxiliary-in port was rare in an automobile, today they are fully connected with USB and Bluetooth ports and the like that integrate media players and cell phones directly into factory sound systems. With this increase demand on automobile sound systems, a requirement for better acoustics in the automobile has been seen in recent years.
Acoustic impedance is an important physical property in substances that determine the substances ability to absorb sound. Specific Acoustic Impedance is the ratio between the sound pressure and the particle velocity produced by a sound wave moving through the substance. When sound waves pass through any physical substance, pressure of the sound waves causes the particles of the substance to move. Specific Acoustic Impedance is also directly related to the resistance of airflow. Specific Acoustic Impedance is measured in RAYLS. The higher number of RAYLS, the lower the velocity of sound transmission through a medium. A fabric is considered to have better acoustic sound absorption with a higher RAYLS number.
Having external noises removed from the automobile cabin is an issue that automobiles of the past did not need to contend with, however, with advancements in digital media and sound systems for cell phones, music and the like, the importance of filtering out external sounds from the driver's cabin is more important than ever before.
In the past, wind noise was a significant cause of noise in automobiles. When automobiles were not aerodynamically shaped as they are now, various objects like chrome molding surrounding the windshield glass created turbulence resulting in wind noise. Wind turbulence around door mounted minors was also a notorious noise maker. However, today's streamlined designs have significantly reduced such turbulence along with its accompanying noise. However, even with the aerodynamic design, today's cars still have air rushing past the vehicle creating noise heard through the doors.
Today noise created by the road traveled is one of the largest contributors to noisy automobile interiors. Road noise typically originates from tires running over road surfaces and may take on two forms of noise called acoustic noise and conductive noise.
Acoustic noise is transmitted from the surface of the road through the air and into the driver's cabin. This noise may be treated by adding acoustical material to surround the driver's cabin and doors. However such materials lack the structural properties and strength as well as the light weight needed for automotive applications.
Conductive road noise is caused by vibrations conducted from the road surface through the automobile's tires and suspension into the driver's cabin. Even with advancements in tire technology to achieve quieter tires noise is still produced by the road and enters into the driver's cabin. With today's common use of run flat tires or low profile tires, these noises are compounded due to the significant amount of less rubber on the tires of today's automobiles. Thus there still remains a need for a material that is structural sound for automotive applications lightweight and produced the acoustic effect necessary to eliminate noise in the driver's cabin for today's electronics and sound systems.
In addition, due to the higher performance automobiles, generation of heat from the engine has become an ever increasing problem. Within the Automotive Industry over the past 50 years, there have been increased requirements for improved flame resistance. After many car fires, the industry adopted standard MVSS 302 from the National Highway Traffic Safety administration. Even with the evolution of all-electric vehicles, there is a need for improved fire resistant and low-smoke fabrics. This test is a horizontal burn test that tests among other things the flammability of the interior of the automobile and engine compart. The test involves taking a sample 14″×4″ and placing the sample on a metal frame. A flame via a Bunsen burner or other device is applied under the front edge of the 4″ width. The flame is placed under the fabric and the fabric is allowed to burn for 15 seconds.
Originally this flame test required that fabric burn less than 101.6 mm/minute (4 inches/minute). The presence of any noxious gases is also observed during the test. Over the years, many automobile manufacturers have made the flame test results more restrictive. Some automotive manufacturers have reduced the burn rate to 2 inches per minute and down to 1 inch per minute. The requirements for some applications, for example such as engine compartment areas, have required that the sample be SE (self-extinguishing) with a zero burn rate and in some cases with the strictest requirement which is DNI (did not ignite).
Recently, several Automotive Manufacturers have focused on another flame test developed by Underwriters Laboratories, a flame test UL-94, which is a vertical flame test. This flame test requires a 5″×½″ fabric sample held vertically. A flame is placed under the fabric sample for two-10 second intervals.
The results of the flame test UL-94 are report as:                HB: slow burning on a horizontal specimen; burning rate <76 mm/min for thickness <3 mm or burning stops before 100 mm        V-2 burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed.        V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.        V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.        5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole.        5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole.
The automotive industry, among other industries, have found it very difficult if not impossible to find fibrous nonwoven fabrics that can meet both the above acoustic and flame resistance requirements. Fabrics are needed in the automotive industry for good acoustical qualities and these fabrics must be located near the engine or exhaust system so flame resistance properties are essential. There is also a need for fabrics with low-smoke properties. Further, there is a need for fabrics that are moldable with standard thermoplastic molding equipment, yet still have excellent thermal stability after molding. There still remains in the art a need for a moldable nonwoven fabric with enhanced flame resistance and excellent thermal stability.
Single layer nonwovens have tried to increase RAYLS by using more fine fibers to create a denser medium to reduce air flow, and hence reduce sound transmission. However this technique has not been achieved at a practical cost or weight.
At the same time, the Automobile Manufacturers have found a need for an Underbody Shield to be moldable, durable and fit under the vehicle to prevent road and wind noise from penetrating upward into the passenger compartment. Further, it has been shown that these composites are weighing close to 2,000 gsm (grams per square meter) to achieve the noise reduction levels desired. This amount of weight is too much for an automobile part due to stability of the vehicle, drag and energy efficiency concerns.
In addition, due to the high heat exposure from engine parts, a need exists for a product that does not exhibit failure during heat aging up to 150° C.; has resistance to water, oil, and engine fluids, has low flame spread and low smoke, and is recyclable back into itself. Further, these moldable products must have excellent abrasion resistance against sand & gravel.
Further environmental factors for automotive products include the exposure to moisture. Any materials coated with heat resistant coatings or coatings that increase acoustic impedance are easily worn away by the harsh environmental conditions of the undercarriage and wheel wells of the automobile. Rain, snow, ice and salt as well as other particles are common environmental conditions that affect an automobile's undercarriage and wheel wells as well as other portions of the automobile. Any coatings or non-structural material used that contain heat resistant or acoustical properties are easily worn away in such environments.
Thus there still exists a need for an acoustic absorber that is thermo-formable or otherwise moldable, light weight, resistant to water penetration and other environmental factors, flame resistance, and has a high RAYLS number.


In one embodiment, a method is provided that may include determining, at least in part, by a device comprised, at least in part, in storage, whether to request that the storage perform, at least in part, at least one operation. The at least one operation may involve, at least in part, at least one object stored in the storage. The determining may be based, at least in part, upon metadata associated with the at least one object. The metadata may be stored in the storage, and may indicate an earliest permitted deletion time for the at least one object and/or a latest permitted access time for the at least one object. Of course, many modifications, variations, and alternatives are possible without departing from this embodiment.

In one conventional data storage system, an array of mass storage devices is coupled to a host. The array stores a plurality of files. Depending upon the particular files' contents, a subset of the files may be subject to a data retention policy promulgated by governmental and/or other authority. For example, such a retention policy may mandate that a file containing a certain type of information must be retained for at least a predetermined minimum period of time, but cannot be retained longer than a predetermined maximum period of time.
In this conventional data storage system, in order to comply with the mandated retention policy, the host executes program processes that determine which of the files should be retained and/or deleted in accordance with the policy. As a result of execution of these processes, the host periodically requests deletion of files stored in the array, and the host prevents user-initiated file deletion requests from being issued to the array, in order to permit files to be deleted and prevented from being deleted, respectively, in accordance with the policy. Unfortunately, the execution of these processes by the host may consume an undesirably large amount of host processing bandwidth. Additionally, if the host fails to execute these processes, one or more files may be retained or deleted in violation of the policy.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments of the claimed subject matter, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly.

Method and apparatus for managing access to stored objects based on retention policy


A vehicle utility rack with a foldable frame and floor. The frame includes a back support and two arms attached to the back support with hinges. Each arm includes a top part and a bottom part forming a track therebetween. When the arms are extended, they allow the floor to extend from a stored position to a working position. The floor includes an end support attached to the exterior end. The end support functions as a wall when the floor is in the working position. When the floor is in the stored position, the arms are locked to the back support. This allows the vehicle utility rack to remain closed, even when the vehicle is in motion.

The present invention relates to utility racks for vehicles. More particularly, the present invention provides a foldable utility rack that is capable of being attached to a hitch mount of a vehicle.
Many people find the need to add extra space to their vehicles to transport large objects or a large quantity of objects. This can be done by adding various types of racks or often by tying things to the roof of a vehicle. In some cases, an extra cargo device can be added to a vehicle's hitch connector. These cargo devices can enable individuals to store coolers, beach items, hunting items, or any other desired items.
Unfortunately, traditional cargo racks are bulky and typically not foldable. These large items also add length to a vehicle and can make them hard to maneuver. However, traditional cargo racks are large and heavy and may not be easy to remove. Therefore, many choose to leave them attached even if they are not in use. This can cause painful results when they are banged into by an individual. In addition, storing traditional cargo racks is often cumbersome, as they occupy a large volume.
Consequently, there is a need for an improvement in the art of vehicle utility racks. The present invention substantially diverges in design elements from the known art, while at the same time solving a problem many individuals face. The present invention provides a vehicle utility rack that easily enables a user to store any desired cargo therein, wherein the vehicle utility rack is collapsible and easy to store, remove, and drive with when empty. In this regard the present invention substantially fulfills the need for a simple, easy to use vehicle utility rack that is also maneuverable between stored and deployed positions.


A steel article has a composition, by weight percent, including from 0.20 to 0.45 carbon, from 0.4 to 1.5 manganese, from 0.5 to 2.0 silicon, from 0.01 to 2.0 chromium, from 0.15 to 1.2 molybdenum, from 0.01 to 0.40 vanadium, from 0.01 to 0.25 titanium, from 0.005 to 0.05 aluminum, from 0.0001 to 0.010 boron, less than 0.002 oxygen, from 0.005 to about 0.017 nitrogen, and the balance essentially iron. The steel article is free of any detrimental aluminum nitride and has, after quenching and tempering, a fully martensitic microstructure and a controlled distribution of spaced apart micrometer size titanium nitride cuboids and nanometer size background carbonitride precipitates.

Ground engaging tools, such as, for example, bucket teeth, ripper tips and track shoes, used in construction machines operating in soil and rock, are subject to harsh two body wear. It is necessary for such ground engaging tools to exhibit a combination of high hardness throughout the tool in order for the tool to resist wear, high fracture toughness in order to prevent tool breakage, and sufficient temper resistance in order to prevent loss of hardness during operation at elevated temperatures.
Several steel compositions have been proposed for applications requiring the desirable combination of hardenability, toughness and temper resistance properties. The heretofore disclosed compositions include a relatively high amount of chromium, i.e., above 3% of chromium by weight. For example, a steel composition mainly intended for use as an excavating tool edge material for construction machines is described in U.S. Pat. No. 3,973,951 issued Aug. 10, 1976 to K. Satsumabayashi et al. This steel has a chromium content in the range of 3.0% to 6.0% by weight. Similarly, a wear resisting steel developed for use as a ripper tip material and having chromium in the range of 3.0% to 5.0% by weight is described in Japanese Patent 54-42812 issued Dec. 17, 1979 to Kabushiki Kaisha Komatsu Seisakusho. Another steel intended for use in mining buckets and other mineral processing operations, and having a composition including chromium in the range of 3.0% to 4.5% by weight is described in U.S. Pat. No. 4,170,479 issued Oct. 9, 1979 to G. Thomas et al.
Other heretofore known steels intended for use in applications requiring a combination of high hardenability and toughness require significant amounts of nickel. Examples of these compositions are disclosed in U.S. Pat. No. 2,791,500 issued May 7, 1957 to F. Foley et al, U.S. Pat. No. 3,165,402 issued Jan. 12, 1965 to W. Finkl et al, U.S. Pat. No. 3,379,582 issued Apr. 23, 1968 to H. Dickenson and, more recently, U.S. Pat. No. 4,765,849 issued Aug. 23, 1988 to W. Roberts, which discloses a steel composition having substantially high amounts of aluminum in the range of 0.4% to 1.0% by weight.
U.S. Pat. No. 5,131,965 issued Jul. 21, 1992 to J. McVicker and assigned to the same company as this instant invention, discloses a steel having high hardenability and toughness. However, McVicker uses higher chromium to attain high hardenability and temper resistance.
U.S. Pat. No. 5,595,614 issued Jan. 21, 1997 to J. McVicker and assigned to the same company as this instant invention, discloses a steel having high hardenability and toughness. However, McVicker uses coherent nitride, carbonitride, and carbide particles to attain fracture toughness.
It has been desirable to have a deep hardening steel having a martensitic microstructure having a predetermined and controlled spacing of .mu. size titanium nitride cuboids to obtain high fracture toughness. It has also been desirable to have a deep hardening steel that has a microstructure having a predetermined and controlled fine scale distribution of incoherent fine scale (10-400 nanometer size) carbonitrides to improve fracture toughness.
The present invention is directed to overcome one or more of the problems as set forth above.

Hardness, strength, and fracture toughness steel


A sample stage is moved so that an alignment mark on a wafer successively move on positions symmetric to the positional origin of the electron beam, and waveformes of signals obtained by scanning the alignment mark at the symmetric positions with electron beam are added each other so as to be symmetry and decrease the alignment-mark position detecting error.

The present invention relates to an electron beam lithography method, particularly to an electron beam lithography method capable of accurately detecting alignment marks while moving a wafer.
In a general electron beam lithography apparatus, a semiconductor wafer is set in a cassette (jig) mounted on a wafer stage to lithograph a chip pattern on the wafer.
The position of the pattern is relatively determined on the basis of alignment marks on the wafer.
An electron beam is deflected in accordance with a lithograph pattern. Therefore, when the position (coordinate values) of an alignment mark is deviated from a design value, it is necessary to correct the deflection signal of the electron beam by the deviation.
The position of an alignment mark is measured by controlling the wafer stage and setting the alignment mark on a wafer to a positional origin of the electron beam (which means the position of the electron beam in the case when the electron beam is not deflected by a deflector).
The alignment mark on the wafer is constructed with a wafer mark 11 which aligns the wafer 206 and a chip mark 12 which aligns chip patterns 13. The positional origin of the electron beam is usually measured by detecting the wafer mark which is moved by moving the wafer stage. Therefore, if the positions of the wafer mark 11 and the chip mark 12 are designed correctly without any positional design error, the positional origin of the electron beam measured by detecting the chip mark is measured correctly too.
But, when the wafer is deformed, the wafer mark is not set correctly on the positional origin of the electron beam measured by detecting the chip mark.
Moreover, positions of alignment marks are conventionally detected by applying the electron beam to the alignment marks and detecting electrons reflected from the marks by means of two reflected electron detectors set at positions symmetrical with respect to the electron beam origin. Therefore, if alignment marks are detected on a position which is apart from the positional origin of the electron beam or the reflected electron detectors are not disposed at positions symmetrical with respect to the origin, waveforms outputted by the reflected electron detectors become asymmetrical and thereby, errors occur in detecting positions of marks.
Japanese Patent Laid-open No. 57-211733(1982) discloses that alignment marks are scanned twice in two different directions and obtained mark detection signals are arithmetically averaged to decrease the errors due to the asymmetrical waveforms.
It is also performed to improve S/N of detection signals by scanning marks several times and arithmetically averaging obtained scanning signals to decrease the influence of random noises.
However, the above method has a problem that it takes much time and the apparatus throughput decreases because a plurality of marks on a wafer are successively measured by repeating the movement and stop of a stage (step-and-repeat system).
Therefore, Japanese Patent Laid-open No. 58200536(1983) discloses the so-called continuous stage moving system for detecting positions of marks while continuously moving a stage.
However, the continuous stage moving system has a problem that measurement errors increase due to asymmetry of detection signal waveforms because each mark position cannot be detected just under the positional origin of the electron beam though the mark detection time can be decreased.
Japanese Patent Laid-open No. 62-29136(1987) discloses a method for setting a function to estimate the skewness of detection signal waveforms and thereby correcting the asymmetry in accordance with scanning position.
Actually, however, asymmetry is not completely corrected because the skewness of mark detection signals cannot accurately be estimated.


A barrier system is provided for fencing in or closing off a designated area. The barrier system includes a body including a longitudinal element extendable from the body to form a barrier between a first surface and a second surface. At least one coupling member is selectively connectable with the body between a first connection configuration such that the body is coupleable to the first surface or the second surface via the at least one coupling member and a second connection configuration such that the body is directly attachable to the first surface or the second surface. Systems and methods are disclosed.

Barriers and/or fencing systems are used to block off a designated area and/or to delineate a pathway in various settings including, for example, airport security, shopping check-out lines, theme park lines, etc. Barriers can also be used to demarcate a perimeter of a crime scene, a scene of an accident or a job site and/or also include visual indicia to passersby.
Barrier systems often include a retractable rope that extends between posts or stanchions forming a barrier therebetween. These barrier systems occupy a substantial amount of space and lack versatility in their application. Additional deficiencies of current barrier systems include an inability to form provisional and/or permanent barriers between both metal and non-metal surfaces while maintaining separate components of the barrier system as one integral unit. This disclosure describes improvements over these prior art technologies.


A sliding mechanism includes a sheet position limiting member having a sheet position limiting surface, the sheet position limiting member being configured to slide in a direction perpendicular to the plane of the sheet position limiting surface; and a guide member configured to guide the sliding of the sheet position limiting member.

1. Field of the Invention
The present invention generally relates to sliding mechanisms, sheet guides, sheet loading devices, and image forming apparatuses.
More specifically, the present invention relates to a sliding mechanism configured to slide a member having a standard surface in a direction perpendicular to the standard surface, and a sheet guide, a sheet loading device, and an image forming apparatus using the sliding mechanism.
2. Description of the Related Art
In a conventional art image forming apparatus, it is necessary for a sheet feeding mechanism to correspond to various sizes of sheet cassettes, depending on the user's need. For this purpose, a side fence for adjusting to the sheet width of a sheet size is required. It is required that the side fence be movable. In most cases, the side fence is adjusted to the sheet width by a manual operation of the user.
Japanese Laid-Open Patent Application Publication No. 2006-248744 describes a sheet material storage vessel, a side register adjusting device and an image forming device that are conventional art examples with respect to a sheet feeding mechanism of an image forming apparatus having a movable type side fence.
With respect to an operational force necessary for moving the side fence, if sliding resistance in the moving direction is too weak, deviation of a printed image may occur due to instability at the time of the sheet conveyance. On the other hand, if the sliding resistance in the moving direction is too strong, the user cannot move the side fence. Accordingly, it is necessary to make the side fence have a proper sliding resistance.
However, in the sheet feeding mechanism of the conventional art image forming apparatus including the invention described in the Japanese Laid-Open Patent Application Publication No. 2006-248744, it is not considered to properly set the sliding resistance of the side fence.
Because of this, the side fence may be shifted at the time of the sheet conveyance so that the deviation of the printed image may occur or it may be difficult for the user to move the side fence.

Sliding mechanism, sheet guide, sheet loading device, and image forming apparatus


A light therapy device (1) comprises: at least one light source (2); a control device (10) for controlling the operation of the light source; a boundary memory (11) containing boundary information defining boundaries for the distance (D) and relative angle (f) of a user's head with respect to the light source; monitoring means (30) for monitoring the actual distance and actual relative angle of the user's head and generating an output signal indicating the measured distance and angle. The control device has an input coupled to the memory for receiving the boundary information, and has an input coupled to the monitoring means for receiving the output signal from the monitoring means. The control device compares the output signal from the monitoring means with the boundary information, and issues a warning signal when the actual position and/or orientation of the user's head and/or eyes is/are outside said boundaries.

Light therapy of this type is for instance used for the treatment of affective disorders or circadian rhythm sleep disorders. Timed bright light therapy is the recommended treatment for Circadian Rhythm Sleep Disorders, especially for Shift Work Disorder and Delayed Sleep Phase Disorder; in this respect, reference can be made to the article "Practice Parameters for the Clinical Evaluation and Treatment of Circadian Rhythm Sleep Disorders" from the American Academy of Sleep Medicine in Sleep, Vol. 30, No. 11, 2007. Such therapy involves exposing patients at properly determined times to white light intensities of typically 2500-10,000 lux for periods ranging from 30 minutes to 2 hours. The most commonly used devices are small light boxes that have to be put on a table in front of the user. More recent light therapy devices make use of only the blue part of the light spectrum, because the shifting effect of the human circadian pacemaker system is most sensitive to blue light.
WO-2010/076708 discloses a device that comprises a head-mounted device in the shape of a mask: in such a case, the relative orientation and distance between the device and the user's eyes are always fixed.


When time-division multiplexed digital data signals are to be demodulated, symbols in a time slot and symbols in the next time slot are stored in memory. The digital data signal in each time slot includes a training sequence. Channel estimators extract channel information regarding stored signals from the signals themselves as well as from the training sequences in succeeding time slots and output the channel information to a channel information generator which combines the channel information from the channel estimators into channel information regarding the signal in the time slot. A demodulator receives the combined channel information and the stored signals and demodulates the signal in the time slot.

1. Field of the Invention:
The present invention relates to a method of and an apparatus for successively transmitting digital data signals using the time-division multiplex access (TDMA) technique and automatically equalizing and demodulating the received digital data signals into output signals based on channel information extracted from the received digital data signals.
2. Description of the Related Art:
As shown in FIG. 1 of the accompanying drawings, data transmission in a TDMA system involves the successive transmission of N-channel data signals in a frame format 32 that are allocated respectively to N time slots 30, 31, each composed of N symbols. The first symbol Np of the frame in each of the time slots 30, 31 comprises a training sequence.
In order to eliminate intersymbol interference caused during data transmission as well as to cope with time-dependent variations in channel characteristics, data receivers in such a TDMA system extract channel information using the training sequences in the received time slots for initializing equalizers and demodulate the received data signal in each of the time slots.
As communication channels are designed for faster, multiplexed communications, short-term variations in the channels become more problematic. There have been proposed various systems capable of quickly following or compensating for burst variations which cannot be ignored in received time slots.
One of the proposed systems is shown in FIG. 2 of the accompanying drawings. The system includes an input terminal 70, an output terminal 71, a channel estimator 72, and a demodulator 73. The channel estimator 72 estimates channel information using a received signal from the input terminal 70 and a decision result from the demodulator 73 to compensate for channel variations (see, for example, K. Okanoue, Improvements on Tracking Performances of Adaptive Viterbi MLSE Receiver, trans. of 1991 Spring National Conference, Institute of Electronics, Information and Communication Engineers, Tokyo, SB-4-4, pp. 2-624, 625, March 1991).
Another proposed system, which is shown in FIG. 3 of the accompanying drawings, has an input terminal 80, an output terminal 81, a channel estimator 82, and a demodulator 83. The channel estimator 82 establishes an equalizer using only received signals from the input terminal 80 and not a priori channel information to compensate for channel variations (see, for example, A. Ushirokawa et al., Viterbi Equalization on Time-varying Channel, 2nd Makuhari Int. Conf. on High Tech., Chiba, A-2-2, pp. 101-104, January 1991).
FIGS. 4 and 5 of the accompanying drawings show still another proposed system. As shown in FIG. 4, the system employs a signal format including at least two training sequences 91, 92 in one time slot 90 and interpolates a plurality of results estimated from the training sequence signals into channel information. An equalizer is established using the channel information thus created to compensate for channel variations. As shown in FIG. 5, the system includes a memory 1002 for storing a signal received in one time slot 90 from an input terminal 1000. Channel estimators 1003, 1004 are supplied with respective training sequence signals 91, 92 from the memory 1002, and estimate channel information at the times the respective training sequence signals 91, 92 are received. The system also has a channel information generator 1005 for combining the estimated channel information from the channel estimators 1003, 1004 into channel information over all the times in the time slot 90. The channel information generator 1005 outputs the produced channel information to a demodulator 1006. The demodulator 1006 demodulates the signal in the time slot 90 stored in the memory 1002, based on the channel information supplied from the channel information generator 1005. The demodulated signal is sent to an output terminal 1001. For more details, see, for example, S. Sampei, Complexity Reduction of RSL-Decision Feedback Equalizer using Interpolation, trans. of 1991 Spring National Conference, Institute of Electronics, Information and Communication Engineers, Tokyo, B-386, pp. 2-386, 1991.
Unfortunately, the above proposed systems suffer the following drawbacks:
The system shown in FIG. 2 controls the demodulator 73 using the decision result from the demodulator 73. If the decision result contains an error, the system will fail to compensate for channel variations, and the error will be transmitted, greatly degrading the characteristics of the received signal. The system shown in FIG. 3 does not produce such an error and is capable of effectively compensating for channel variations. However, because its algorithm for establishing an equalizer to compensate for channel variations is complex, the system is relatively large in scale. The system shown in FIGS. 4 and 5 is not large in scale and has a high capability to compensate for channel variations. However, it requires a plurality of training sequences in one time slot, resulting in a reduction in transmission efficiency. As the speed of channel variations increases, the system fails to compensate for the channel variations with sufficient accuracy based only on estimated values from the conventional training sequences and requires more training sequences, which in turn further reduces transmission efficiency.

Reception of TDMA digital data signal with compensation for channel variations


A method of fabricating a patterned magnetic recording medium, comprises steps of: (a) providing a layer stack including an uppermost non-magnetic interlayer; (b) forming a resist layer on the interlayer; (c) forming a first pattern comprising a first group of recesses extending through the resist layer and exposing a first group of spaced apart surface portions of the interlayer; (d) filling the first group of recesses with a layer of a hard mask material; (e) selectively removing the resist layer to form a second pattern comprising a second group of recesses extending through the hard mask layer and exposing a second group of spaced apart surface portions of the interlayer; and (f) filling the second group of recesses with a layer of a magnetically hard material forming a magnetic recording layer.

Designers, manufacturers, and users of electronic computers and computing systems require reliable and efficient equipment for storage and retrieval of information in digital form. Conventional storage systems, such as magnetic disk drives, are typically utilized for this purpose and are well known in the art. However, the amount of information that is digitally stored continually increases, and designers and manufacturers of magnetic recording media work to increase the storage capacity of magnetic disks.
In conventional magnetic disk data/information storage, the data/information is stored in a continuous magnetic thin film overlying a substantially rigid, non-magnetic disk. Each bit of data/information is stored by magnetizing a small area of the thin magnetic film using a magnetic transducer (write head) that provides a sufficiently strong magnetic field to effect a selected alignment of the small area (magnetic grain) of the film. The magnetic moment, area, and location of the small area comprise a bit of binary information which must be precisely defined in order to allow a magnetic read head to retrieve the stored data/information.
Conventional thin-film type magnetic media, wherein a fine-grained polycrystalline magnetic alloy layer serves as the active recording layer, are generally classified as "longitudinal" or "perpendicular", depending upon the orientation of the residual magnetization of the grains of the magnetic material.
Perpendicular recording media have been found to be superior to longitudinal media in achieving higher bit densities without experiencing the thermal stability limit associated with the latter (described in more detail below). In perpendicular magnetic recording media, residual magnetization is formed in a direction ("easy axis") perpendicular to the surface of the magnetic medium, typically a layer of a magnetic material on a suitable substrate. Very high to ultra-high linear recording densities are obtainable by utilizing a "single-pole" magnetic transducer or "head" with such perpendicular magnetic media.
Efficient, high bit density recording utilizing a perpendicular magnetic medium typically requires interposition of a relatively thick (as compared with the magnetic recording layer), magnetically "soft" underlayer ("SUL"), i.e., a magnetic layer having a relatively low coercivity typically not greater than about 1 kOe, such as of a NiFe alloy (Permalloy), between a non-magnetic substrate, e.g., of glass, aluminum (Al) or an Al-based alloy, and a magnetically "hard" recording layer having relatively high coercivity, typically about 3-8 kOe, e.g., of a cobalt-based alloy (e.g., a Co—Cr alloy such as CoCrPtB) having perpendicular anisotropy. The magnetically soft underlayer serves to guide magnetic flux emanating from the head through the magnetically hard perpendicular recording layer.
A conventionally structured perpendicular recording system 10 with a perpendicularly oriented magnetic medium 1 and a magnetic transducer head 9 is schematically illustrated in cross-section in FIG. 1, wherein reference numeral 2 indicates a non-magnetic substrate, reference numeral 3 indicates an optional adhesion layer, reference numeral 4 indicates a relatively thick magnetically soft underlayer (SUL), reference numeral 5 indicates an "intermediate" layer stack 5 which may include at least one non-magnetic interlayer 5B of a hcp material adjacent the magnetically hard perpendicular recording layer 6 and an optional seed layer 5A adjacent the magnetically soft underlayer (SUL) 4, and reference numeral 6 indicates at least one relatively thin magnetically hard perpendicular recording layer with its magnetic easy axis perpendicular to the film plane.
The relatively thin interlayer 5, comprised of one or more layers of non-magnetic materials, e.g., interlayer 5B and seed layer 5A, serves to (1) prevent magnetic interaction between the magnetically soft underlayer (SUL) 4 and the at least one magnetically hard recording layer 6; and (2) promote desired microstructural and magnetic properties of the at least one magnetically hard recording layer 6.
Still referring to FIG. 1, reference numerals 9M and 9A, respectively, indicate the main (writing) and auxiliary poles of the magnetic transducer head 9. As shown by the arrows in the figure indicating the path of the magnetic flux φ, flux φ emanates from the main writing pole 9M of magnetic transducer head 9, enters and passes through the at least one vertically oriented, magnetically hard recording layer 6 in the region below main pole 9M, enters and travels within soft magnetic underlayer (SUL) 4 for a distance, and then exits therefrom and passes through the at least one perpendicular hard magnetic recording layer 6 in the region below auxiliary pole 9A of transducer head 9. The relative direction of movement of perpendicular magnetic medium 21 past transducer head 9 is indicated by the arrow in the figure.
Completing the layer stack of medium 1 is a protective overcoat layer 7, such as of a diamond-like carbon (DLC), formed over magnetically hard layer 6, and a lubricant topcoat layer 8, such as of a perfluoropolyether (PFPE) material, formed over the protective overcoat layer.
Substrate 2, in hard disk applications, is disk-shaped and comprised of a non-magnetic metal or alloy, e.g., Al or an Al-based alloy, such as Al—Mg having a Ni—P plating layer on the deposition surface thereof, or alternatively, substrate 2 is comprised of a suitable glass, ceramic, glass-ceramic, polymeric material, or a composite or laminate of these materials. Optional adhesion layer 3, if present on substrate surface 2, may comprise a less than about 200 Å thick layer of a metal or a metal alloy material such as Ti, a Ti-based alloy, Ta, a Ta-based alloy, Cr, or a Cr-based alloy. The relatively thick soft magnetic underlayer 4 may be comprised of an about 50 to about 300 nm thick layer of a soft magnetic material such as Ni, Co, Fe, an Fe-containing alloy such as NiFe (Permalloy), FeN, FeSiAl, FeSiAlN, FeTaC, a Co-containing alloy such as CoZr, CoZrCr, CoZrNb, or a Co—Fe-containing alloy such as CoFeZrNb, CoFeZrTa, CoFe, FeCoB, FeCoCrB, and FeCoC. Relatively thin intermediate layer stack 5 may comprise an about 50 to about 300 Å thick layer or layers of non-magnetic material(s). For example, intermediate layer stack 5 includes at least one non-magnetic interlayer 5B of a hcp material, such as Ru, TiCr, Ru/CoCr37Pt6, RuCr/CoCrPt, etc., adjacent the magnetically hard perpendicular recording layer 6. When present, seed layer 5A adjacent the magnetically soft underlayer (SUL) 4 may comprise a less than about 100 Å thick layer of an fcc material, such as an alloy of Cu, Ag, Pt, or Au, or a material such as Ta, TaW, CrTa, Ti, TiN, TiW, or TiCr. The at least one magnetically hard perpendicular recording layer 6 preferably comprises a high coercivity magnetic alloy with a hexagonal close-packed (hcp) <0001> basal plane crystal structure with uniaxial crystalline anisotropy and magnetic easy axis (c-axis) oriented perpendicular to the surface of the magnetic layer or film. Such magnetically hard perpendicular recording layers typically comprise an about 6 to about 25 nm thick layer(s) of Co-based alloy(s) including one or more elements selected from the group consisting of Cr, Fe, Ta, Ni, Mo, Pt, W, Cr, Ru, Ti, Si, O, V, Nb, Ge, B, and Pd.
Conventional, continuous magnetic film storage media such as described above incur several drawbacks and disadvantages which adversely affect realization of high areal density data/information storage, as follows:
(1) the boundaries between adjacent pairs of bits tend to be ragged in continuous magnetic films, resulting in noise generation during reading; and
(2) the requirement for increased areal recording density has necessitated a corresponding decrease in recording bit size or area. Consequently, recording bit sizes of continuous film media have become extremely minute, e.g., on the order of nanometers (nm). In order to obtain a sufficient output signal from such minute bits, the saturation magnetization (Ms) and thickness of the film must be as large as possible. However, the magnetization quantity of such minute bits is extremely small, resulting in a loss of stored information due to magnetization reversal by "thermal fluctuation", also known as the "superparamagnetic effect".
Regarding item (2) above, it is further noted that for longitudinal type continuous magnetic media, wherein the magnetic easy axis is oriented parallel to the film plane (i.e., surface), magnetization reversal by the superparamagnetic effect may occur even with relatively large magnetic particles or grains, thereby limiting future increases in areal recording density to levels necessitated by current and projected computer-related applications. On the other hand, for perpendicular type continuous magnetic media, wherein the magnetic easy axis is oriented perpendicular to the film plane (i.e., surface), growth of the magnetic particles or grains in the film thickness direction increases the volume of magnetization of the particles or grains while maintaining a small cross-sectional area (as measured in the film plane). As a consequence, onset of the superparamagnetic effect can be suppressed for very small particles or grains of minute width. However, further decrease in grain width in perpendicular media necessitated by increasing requirements for areal recording density will inevitably result in onset of the superparamagnetic effect even for such type media.
The superparamagnetic effect is a major limiting factor in increasing the areal recording density of continuous film magnetic recording media. Superparamagnetism results from thermal excitations which perturb the magnetization of grains in a ferromagnetic material, resulting in unstable magnetization. As the grain size of magnetic media is reduced to achieve higher areal recording density, the superparamagnetic instabilities become more problematic. The superparamagnetic effect is most evident when the grain volume V is sufficiently small such that the inequality KμV/kBT>40 cannot be maintained, where Kμ is the magnetic crystalline anisotropy energy density of the material, kB is Boltzmann's constant, and T is the absolute temperature. When this inequality is not satisfied, thermal energy demagnetizes the individual magnetic grains and the stored data bits are no longer stable. Consequently, as the magnetic grain size is decreased in order to increase the areal recording density, a threshold is reached for a given Kμ and temperature T such that stable data storage is no longer possible.
So-called "patterned" or "bit patterned" magnetic media ("BPM") have been proposed as a means for overcoming the above-described problem of conventional continuous magnetic media associated with magnetization reversal via the superparamagnetic effect, e.g., as disclosed in U.S. Pat. No. 5,956,216, the entire disclosure of which is incorporated herein by reference. The term "bit patterned media" ("BPM") generally refers to magnetic data/information storage and retrieval media wherein a plurality of discrete, independent regions of magnetic material which form discrete, independent magnetic elements that function as recording bits are formed on a non-magnetic substrate. Since the regions of ferromagnetic material comprising the magnetic bits or elements are independent of each other, mutual interference between neighboring bits can be minimized. As a consequence, bit patterned magnetic media are advantageous vis-a-vis continuous magnetic media in reducing recording losses and noise arising from neighboring magnetic bits. In addition, patterning of the magnetic layer advantageously increases resistance to domain wall movement, i.e., enhances domain wall pinning, resulting in improved magnetic performance characteristics.
Generally, each magnetic bit or element has the same size and shape, and is composed of the same magnetic material as the other elements. The elements are arranged in a regular pattern over the substrate surface, with each element having a small size and desired magnetic anisotropy, so that, in the absence of an externally applied magnetic field, the magnetic moments of each discrete magnetic element will be aligned along the same magnetic easy axis. The magnetic moment of each discrete magnetic element therefore has only two states: the same in magnitude but aligned in opposite directions. Each discrete magnetic element forms a single magnetic domain or bit and the size, area, and location of each domain is determined during the fabrication process.
During writing operation of patterned media, the direction of the magnetic moment of the single magnetic domain element or bit is flipped along the easy axis, and during reading operation, the direction of the magnetic moment of the single magnetic domain element or bit is sensed. While the direction of the magnetic easy axis of each of the magnetic domains, elements, or bits can be parallel or perpendicular to the surface of the domain, element, or bit, corresponding to conventional continuous longitudinal and perpendicular media, respectively, bit patterned media comprised of domains, elements, or bits with perpendicularly oriented magnetic easy axis are advantageous in achieving higher areal recording densities for the reasons given above.
Bit patterned media in disk form offer a number of advantages relative to conventional disk media. In principle, the writing process is greatly simplified, resulting in much lower noise and lower error rate, thereby allowing much higher areal recording density. In bit patterned media, the writing process does not define the location, shape, and magnetization value of a bit, but merely flips the magnetization orientation of a patterned single domain magnetic structure. Also in principle, writing of data can be essentially perfect, even when the transducer head deviates slightly from the intended bit location and partially overlaps neighboring bits, as long as only the magnetization direction of the intended bit is flipped. By contrast, in conventional magnetic disk media, the writing process must define the location, shape, and magnetization of a bit. Therefore, with such conventional disk media, if the transducer head deviates from the intended location, the head will write to part of the intended bit and to part of the neighboring bits. Another advantage of bit patterned media is that crosstalk between neighboring bits is reduced relative to conventional media, whereby areal recording density is increased. Each individual magnetic element, domain, or bit of a patterned medium can be tracked individually, and reading is less jittery than in conventional disks.
Bit patterned magnetic recording media have been fabricated by a variety of processing techniques, including etching processing such as reactive ion etching, sputter etching, ion milling, and ion irradiation to form a pattern comprising magnetic and non-magnetic surface areas in a layer of magnetic material on a media substrate. Several of the these processing techniques have relied upon selective removal of portions of the layer of magnetic material to form the pattern of magnetic and non-magnetic surface areas; whereas others of the processing techniques have relied upon partial removal of selected areas of the media substrate on which the magnetic layer is formed, thereby resulting in different transducer head/media surface spacings having an effect similar to formation of a pattern of magnetic and non-magnetic surface areas in the layer of magnetic material. However, a drawback associated with each of these techniques is formation of topographical patterns in the surface of the media, engendering media performance concerns such as transducer head flyability and corrosion, e.g., due to uneven lubricant thickness and adhesion. A particular drawback associated with a "subtractive" process, i.e., wherein a continuous magnetic recording layer is initially deposited on a substrate and then patterned via ion milling or sputter etching, is the difficulty in accurately performing the milling or etching steps because of redeposition of the removed material(s).
As for formation of patterned magnetic media via ion irradiation, a drawback associated therewith is the requirement for use of a high dose of ion irradiation for sufficient suppression of the magnetic properties of the magnetic layer at the selectively irradiated surface areas. Such high dose ion irradiation typically requires an extended processing interval and removal of the ion-irradiated resist materials (utilized for defining the pattern of ion-irradiated surface areas) is difficult.
In view of the foregoing, there exists a need for improved processing methodology and techniques which substantially eliminate the above-described disadvantages, drawbacks, and difficulties associated with the above-described methodologies and techniques for fabricating patterned magnetic media. More specifically, there exists a need for improved processing methodology and techniques for cost-effectively fabricating servo-patterned media, track-patterned (i.e., discrete track) media, and bit-patterned (i.e., discrete bit) media, particularly as utilized in hard disk data/information storage and retrieval systems.
The present invention addresses and solves the above-described problems associated with the above-described methodologies and techniques for fabricating patterned magnetic media, while maintaining full compatibility with all aspects of cost-effective, automated manufacturing processing for pattern formation in magnetic media. Further, the methodology afforded by the present invention enjoys diverse utility in the manufacture of all manner of devices and products requiring pattern formation in a layer of magnetic material.

Process for fabricating patterned magnetic recording media


A diesel exhaust conditioning system removes harmful gaseous and particulate pollutants from the exhaust of a diesel engine, and also lowers the temperature of the emitted exhaust and of the shroud surrounding the pollution control components of the device. The system includes at least one combination catalytic converter and particulate filter, structured to operate at a sufficiently high temperature as to convert potentially harmful gaseous pollutants to innocuous substances, and which also collects and oxidizes carbon and hydrocarbon particles in the diesel exhaust to convert them to innocuous substances as well. The catalytic converter(s) is contained in an insulated canister for containing the heat generated by the catalytic reactions, with the insulation also serving to lower the outside temperature of the canister. A shroud is placed around the canister and other components, with an axial fan blowing ambient air between the canister and shroud to reduce the exterior temperature of the shroud to an acceptable level. The ambient air is mixed with the exhaust at the downstream end of the system, to lower the temperature of the exhaust gases to an acceptable level. The system is particularly well suited for use with diesel engines used in enclosed environments, such as the underground mining industry, but may be structured for use with diesel engines operating in other environments as well. A seamless, explosion proof shroud may also be used in environments where potential explosion hazards may exist, such as potentially explosive gases and dust in an underground mining environment.

1. Field of the Invention
The present invention relates generally to emissions control systems for internal combustion engines, and more specifically to an exhaust conditioning system for diesel engines. The present system provides for the reduction of oxides of nitrogen, carbon monoxide, and unburned hydrocarbons, as well as the reduction of carbon particulates in the diesel exhaust, using one or more combination catalytic converters and particulate filters. A shroud surrounds the catalytic converter-filter and other components, to insulate the system and reduce external temperatures.
2. Description of the Related Art
Exhaust emissions from internal combustion engines are recognized to be a very serious environmental hazard, and accordingly, numerous ever more stringent laws and regulations require ever cleaner and purer exhaust emissions from such engines. Regulations directed to the diesel or compression ignition engine have generally not been quite so strict as those directed to spark ignition engines, due to the smaller number of diesel engines in operation and also due to the difficulty in reducing or eliminating the carbon particulates normally emitted by such engines.
Nevertheless, the reduction of exhaust emission products from diesel engines is important, particularly for such engines which are used in confined areas, such as generators in enclosed areas, diesel powered machinery used in the underground mining industry, etc. Obviously, it is critical that exhaust emissions be minimized to the greatest degree possible, particularly in the underground mining environment, where breathable air is absolutely critical and toxic gases such as carbon monoxide cannot be tolerated to any degree whatsoever.
Due to these factors, and the difficulty in reducing exhaust emissions from diesel engines to the required degree, many, if not most, jurisdictions either prohibit or greatly restrict the use of diesel powered machinery in underground mining operations. Those that permit such diesel machinery to be used in underground mining, require extremely strict emissions control for such engines. The Pennsylvania Article II-A Diesel Powered Equipment regulations, for example, require that carbon monoxide emissions be reduced to no more than 100 parts per million (ppm), that carbon particulates be reduced by 95% or more from their otherwise unrestricted output, and that exhaust gas temperatures be reduced to no more than 150 degrees Celsius (302 degrees Fahrenheit). These regulations have heretofore generally been considered to be mutually exclusive, as the reduction of emissions by means of a catalytic converter results in considerable heat output from the converter due to the catalytic reaction which serves to clean the emissions. Moreover, the particulate matter is another problem altogether.
Various means have been attempted to resolve this problem, with the solution generally being to cool the reaction in some manner to reduce the temperatures, while trapping the particulates in a separate filter element or the like and cleaning or disposing of the filter periodically. Water has been used as a filtering element, but the resulting sludge creates a maintenance headache and disposal problem, and water per se does little or nothing to reduce other emissions.
Accordingly, a need will be seen for a means of reducing the exhaust emissions of a diesel engine, particularly an engine in an enclosed environment such as an underground mine, and simultaneously reducing the carbon particulate output and temperature of the exhaust. The emissions and particulate reductions are preferably accomplished by means of a single system, rather than requiring separate catalytic converters and filters, although multiple catalytic converter units for treating different types of exhaust pollutants might be used, if so desired. Moreover, the temperature of the converter(s) and filter(s) combination should be maintained at a sufficiently high level so as to operate efficiently, with the system still producing a relatively cool exhaust at or below the above noted Pennsylvania requirements. A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is presented immediately below.
U.S. Pat. No. 3,645,093 issued on Feb. 29, 1972 to William L. Thomas describes an Air Pollution Control System For Internal Combustion Engines, comprising a combustion chamber into which unburned or partially burned hydrocarbons and/or exhaust products are passed. An air pump forces additional oxygen into the chamber for further combustion of the exhaust products, with an ignition source also being provided. A separate coolant pump is used to circulate a liquid coolant around the outside of the combustion chamber shell. No catalytic converter is disclosed by Thomas. The air pump does not provide any cooling for the system, as does the axial fan of the present exhaust system. Rather, the Thomas air pump creates additional heat by providing further oxidation of exhaust output, thus requiring Thomas to provide cooling for the system using some other means, i.e., liquid.
U.S. Pat. No. 3,820,327 issued on Jun. 28, 1974 to Claude Henault describes a Temperature Regulator For A Catalytic Converter, in which air warmed by passing through an engine coolant radiator, or ambient air, is selectively passed through a shroud around a catalytic converter in order to control the temperature of the converter. While some form of temperature regulation of a catalytic converter used in the present invention could be incorporated, the airflow provided by the cooling fan of the present system is not for cooling the converter-filter, but rather for cooling the outside of the converter canister and surrounding shroud in order to reduce the temperature of the shroud to a point no higher than 150 degrees Celsius.
U.S. Pat. No. 3,967,929 issued on Jul. 6, 1976 to Tsuyoshi Tamazawa et al. describes an Exhaust Gas Purifying System incorporating an air pump for delivering additional air into the exhaust manifold for further oxidation of unburned hydrocarbons and the like, but further incorporating a selector valve for routing the air through a catalytic converter downstream from the exhaust manifold. The theory of operation is that the excess air may be routed through the catalytic converter for cooling the converter if it gets too hot. However, the excess air would serve to oxidize unburned hydrocarbons in the converter, thus further increasing the heat output of the converter. The air delivery system of the present invention circulates around the outside of the converter and filter, between the converter canister and surrounding shroud, to cool the exterior of the shroud below a predetermined level.
U.S. Pat. No. 4,264,344 issued on Apr. 28, 1981 to Otto A. Ludecke et al. describes a Diesel Engine Exhaust Particulate Trap comprising two concentric filter elements, unlike the axially disposed elements of the present system. At least the outer element of the Ludecke et al. device is formed of material such as pleated paper, which is totally unsuitable for use with the heat developed by the catalytic converter-filter element of the present invention. The present invention serves to remove carbon particulates by heating the catalytic converter-filter element(s) sufficiently highly by means of its reactions with carbon monoxide and other exhaust pollutants, to break down and oxidize such carbon particles as they pass through the converter-filter.
U.S. Pat. No. 4,744,217 issued on May 17, 1988 to Dieter Goerlich et al. describes a Particle Separator Arrangement In An Exhaust Pipe Of A Diesel Engine. The device includes a particle trap with further means for providing hot gases into the separator to burn out the carbon particles trapped therein, from time to time. The present invention does not include a separate particulate trap, but rather makes use of the combination filter and catalytic converter(s) used in the system to trap such particulates. The converter-filter(s) operate at a sufficiently high temperature to oxidize any unburned carbon particulates entering the converter, and thereby continuously and automatically clean the converter of particulates once the converter warms to normal operating temperature. The fan means used with the present invention does not cool the converter core, but rather directs cooling airflow around the outside of the converter-filter canister and between the canister and shroud to cool the exterior of the device to no more than a predetermined maximum temperature.
U.S. Pat. No. 5,105,619 issued on Apr. 21, 1992 to Minoru Arai describes a Regeneration System For Particulate Trap, wherein the heating means for the trap is an electric resistance heater. The present system utilizes the existing catalytic converter(s) both to trap particulates as well as to oxidize those trapped particulates by means of the heat generated in the catalytic converter(s). Arai does not disclose a catalytic converter, nor any air ducting around the exterior of the trap, as is provided for cooling the exterior housing of the present system.
U.S. Pat. No. 5,243,819 issued on Sep. 14, 1993 to Siegfried Woerner et al. describes an Exhaust Gas Cleaning Device For Diesel Engines, similar to the particulate separators or traps disclosed by Goerlich et al. and Arai and discussed above. Woerner et al. use a supplementary burner to heat the trap, rather than providing a combination catalytic converter-filter and using the heat of the catalytic reaction to burn off the particulates, as is done in the present invention. Moreover, Woerner et al. provide for the routing of the supplemental burner gases around the outside of the trap, in order to heat the relatively cooler outer portions of the trap. The present invention provides insulation around the catalytic converter canister, which serves (1) to maintain the heat of the converter for more efficient reaction, and (2) to reduce the convected heat to below a predetermined maximum level.
U.S. Pat. No. 5,272,874 issued on Dec. 28, 1993 to Norbert Paas describes an Exhaust Treatment System for mine certified diesel engines, for reducing exhaust emissions, particulates, and cooling the exhaust, as required by regulations. However, Paas goes about the solution to the problem in an entirely different manner than that of the present invention, using a considerably more complex apparatus which requires intermittent cleaning and replacement of certain elements. Paas provides a plurality of relatively small catalytic converters at each exhaust manifold tube, which small converters are inefficient and difficult to heat to the desired temperature for optimum operation, particularly in view of the water cooled exhaust manifold tubes immediately upstream of each of the converters. The present invention preferably utilizes a single combination catalytic converter and filter, or alternatively a series of two or more, rather than a plurality of such converters in parallel, as does Paas. Also, while Paas states that his catalytic converters serve to eliminate some of the particulate matter from the exhaust, he must rely upon a particulate filter downstream of the catalytic converters in order to remove the balance of particulate material, whereas the present system uses the catalytic converters to remove essentially all of the particulate material required to be removed from the exhaust by regulation. No additional filters or other elements are required in the present invention. Paas then circulates the engine exhaust through a heat exchanger in order to cool it sufficiently to pass through a relatively inexpensive disposable filter. However, the carbon buildup within the relatively cool heat exchanger must be handled in some manner. Paas responds to this problem by injecting water into the system from time to time, which flashes to steam to blow the carbon residue from the heat exchanger. While the Paas system does allow a relatively inexpensive, disposable exhaust particulate filter to be used, the apparatus providing for such an inexpensive filter is relatively complex and costly, unlike the present system. Where Paas uses water to cool his exhaust system, the present system is cooled with air, with the cooling medium never entering the exhaust system until the exhaust has been completely processed, at the extreme output end of the system.
U.S. Pat. No. 5,403,557 issued on Apr. 4, 1995 to Harold L. Harris describes an Emission Control Apparatus For Diesel Engine, including a particulate trap and noise reduction device combined in a single unit. The particulate trap is upstream of a separate catalytic converter, to remove substantially all of the particulates from the exhaust gases before they reach the converter, unlike the present invention which utilizes the combination converter and filter to remove particulates in addition to other undesirable exhaust gases. While Harris also provides some sound muffling means with his apparatus, he is silent regarding any means of reducing the exterior temperature of the device. The present system includes external temperature reduction means, comprising a fan for air flow between the insulated catalytic converter canister and a surrounding shroud.
U.S. Pat. No. 5,431,706 issued on Jul. 11, 1995 to Norbert Paas describes a Disposable Particulate Filter generally comprising a pair of concentric, toroidally shaped filter elements. Exhaust passes between the two elements, with filtered exhaust passing either outwardly around the outermost element, or centrally outward from the center of the inner element. Paas notes that experiments wherein the semi-permanent catalytic converter element has been used to trap and oxidize the particulate material from a diesel exhaust have not been successful when such engines are used in light duty cycles (column 1, lines 62-68), but fails to consider insulating the converter to retain heat and to reduce the temperature of the outer shell, as is done in the present invention.
Finally, U.S. Pat. No. 5,488,826 issued on Feb. 6, 1996 to Norbert Paas describes a Heat Isolated Catalytic Converter. This patent is a continuation in part of Paas' earlier issued U.S. Pat. No. 5,272,874, and incorporates a similar catalytic converter structure, with separate converters housed in each exhaust manifold tube from each exhaust port of the engine. However, the continuation patent provides for a pair of annular insulation gaps or spaces concentric with each converter, to reduce heat transfer to the exhaust manifold tubes. It would appear that Paas recognized the shortcomings of the catalytic converter structure of his earlier issued '874 patent, with the relatively small converters in direct contact with the liquid cooled exhaust manifold tubes and resulting inability of the converters to attain sufficient temperature for suitable operation and for achieving the stated purpose of oxidizing some of the particulate matter of the diesel exhaust. However, the plural, relatively small converters of the Paas '826 patent are still considerably more difficult to heat to an optimum operating temperature than the present single converter and filter combination, or plural converters and filters in series, of the present invention, and the liquid cooling provided by Paas further lowers the temperature of adjacent structures to a degree considerably less than that desired or permitted by regulation.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.


A method of comparing voice samples to reduce false alarms by receiving a first voice sample, generating a model of the first voice sample, reordering the first voice sample, generating a model of the reordered first voice sample; receiving a second voice sample; generating a model of the second voice sample; reordering the second voice sample, generating a model of the reordered second voice sample, comparing at least one pairings of the models, and determining if the first voice sample matches the second voice sample if the model comparisons are within a user-definable threshold.

Voice comparisons are used in speaker identification, recognition, authentication, and verification. False alarms occur in these methods when two voice samples that are different are compared and determined to be identical. False alarms reduce the performance of automated voice comparison methods. There is a need for a voice comparison method that reduces false alarms. The present invention is such a method.
U.S. Pat. No. 4,241,329, entitled "CONTINUOUS SPEECH RECOGNITION METHOD FOR IMPROVING FALSE ALARM RATES," discloses a method of recognizing keywords in continuous speech with improved false alarm rates by characterizing each keyword to be recognized by a template, selecting a sequence of patterns from a signal, comparing the pattern to the templates, determining which template matches the pattern, and applying a prosodic test to determine if the determination is a false alarm or not. The present invention does not characterize keywords with templates, compare patterns to templates, or apply a prosodic test to determine false alarms as does U.S. Pat. No. 4,241,329. U.S. Pat. No. 4,241,329 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. Nos. 6,076,055 and 6,931,375 and U.S. Pat. Appl. No. 20050143996, each entitled "SPEAKER VERIFICATION METHOD," each disclose a method of verifying that a speaker is who the speaker claims to be by generating a code book, acquiring a number of training utterances from each of a number of speakers, receiving a number of test utterances, comparing the test utterances to the training utterances to form a number of decisions, weighting each decision, and combining the weighted decisions to form a verification decision. The present invention does not generate a code book, acquire a number of training utterances from each of a number of speakers, weight decisions, or combine weighted decisions to form a verification decision as does U.S. Pat. Nos. 6,076,055 and 6,931,375 and U.S. Pat. Appl. No. 20050143996. U.S. Pat. Nos. 6,076,055 and 6,931,375 and U.S. Pat. Appl. No. 20050143996 are hereby incorporated by reference into the specification of the present invention.

Method of comparing voice signals that reduces false alarms

The U.S. Goverment as Represented By The Director, National Security Agency


The present document relates to audio signal processing, in particular to an apparatus and a corresponding method for improving the audio signal of an FM stereo radio receiver. In particular, the present document relates to a method and system for reducing the noise of a received FM stereo radio signal. An apparatus (2) configured to reduce noise of a received multi-channel FM radio signal is described, wherein the received multi-channel FM radio signal is representable as a received mid signal and a received side signal. The apparatus (2) comprises a parameter determination unit (77) configured to determine one or more parameters indicative of a correlation and/or decorrelation between the received mid signal and the received side signal; and a noise reduction unit (79) configured to generate a noise-reduced side signal from the received mid signal and not from the received side signal using the one or more parameters.

In an analog FM (frequency modulation) stereo radio system, the left channel (L) and right channel (R) of the audio signal are conveyed in a mid-side (M/S) representation, i.e. as mid channel (M) and side channel (S). The mid channel M corresponds to a sum signal of L and R, e.g. M=(L+R)/2, and the side channel S corresponds to a difference signal of L and R, e.g. S=(L−R)/2. For transmission, the side channel S is modulated onto a 38 kHz suppressed carrier and added to the baseband mid signal M to form a backwards-compatible stereo multiplex signal. This multiplex baseband signal is then used to modulate the HF (high frequency) carrier of the FM transmitter, typically operating in the range between 87.5 to 108 MHz.
When reception quality decreases (i.e. the signal-to-noise ratio over the radio channel decreases), the S channel typically suffers more during transmission than the M channel. In many FM receiver implementations, the S channel is muted when the reception conditions gets too noisy. This means that the receiver falls back from stereo to mono in case of a poor HF radio signal (typically referred to as a mono dropout).
Even in case the mid signal M is of acceptable quality, the side signal S may be noisy and thus can severely degrade the overall audio quality when being mixed in the left and right channels of the output signal (which are derived e.g. according to L=M+S and R=M−S). When a side signal S has only poor to intermediate quality, there are two options: either the receiver chooses accepting the noise associated with the side signal S and outputs a real stereo signal comprising a noisy left and right signal, or the receiver drops the side signal S and falls back to mono.
Parametric Stereo (PS) coding is a technique from the field of very low bitrate audio coding. PS allows encoding a 2-channel stereo audio signal as a mono downmix signal in combination with additional PS side information, i.e. the PS parameters. The mono downmix signal is obtained as a combination of both channels of the stereo signal. The PS parameters enable the PS decoder to reconstruct a stereo signal from the mono downmix signal and the PS side information. Typically, the PS parameters are time- and frequency-variant, and the PS processing in the PS decoder is typically carried out in a hybrid filterbank domain incorporating a plurality of Quadrature Mirror Filter (QMF) banks.
It has been proposed in WO2011/029570, PCT/EP2011/064077 and PCT/EP2011/064084 to use PS encoding of a received FM stereo signal in order to reduce the noise comprised within the received FM stereo signal. The general principle of the Parametric Stereo (PS) based FM stereo radio noise reduction technology is to use parametric stereo parameters derived from the received FM stereo signal, in order to reduce the noise comprised in the received left and right signals. The disclosure of the above mentioned patent documents is incorporated by reference.

Prediction-based FM stereo radio noise reduction