A system and method for providing the ability for a network processor to select from multiple next hop options for a single forwarding entry and provide the ability to weight the probability of which next hop will be chosen.

1. Field of the Invention
This invention relates generally to network processor devices, routers, and the like and, more specifically, to a packet forwarding table and packet routing method which provides multiple next hop options for a single forwarding entry and the ability to weight the probability with which each next hop is to be chosen.
2. Discussion of the Prior Art
Traditional packet routing capability provided in network processor devices, routers, switches, and the like, typically utilize a network routing table having entries which provide a single next hop for each table entry. FIG. 1 depicts a typical network routing scenario 10. To route a packet from System C 13 to System 3 indicated as element 18 in FIG. 1, a traditional packet forwarding table would provide one path (e.g., via router R2) from router R5 to R1. In the example network routing scenario of FIG. 1, it would be desirable to have the ability to route through R3 as well, or possibly even through R4.
In general, in a network processor, the ability to provide multiple next hop options coupled with the ability to weight which router in the network handles the amount of or what type of packets is very desirable.
It is an object of the present invention to provide a network processor with a network routing table having entries that include one or more next hops in addition to cumulative probability data for each corresponding next hop.
It is another object of the present invention to provide a method of randomly generating next hop seed values associated with a packet to be forwarded in a network and determining which next hop is chosen based on cumulative probability data for each corresponding next hop and the randomly generated next hop seed values.
According to the invention, there is provided a system and method for forwarding packets in a network processor (NP) device comprising: providing entries in a packet forwarding table for mapping a destination address associated with a packet to be forwarded to multiple, weighted next hop options in a networking environment; computing a weighting parameter based on data associated with the packet to be forwarded; and, routing the packet via one of the multiple next hop option selected in accordance with the computed weighting parameter. Preferably, the computing step includes applying a hash function to data associated with the packet to be forwarded to generate a corresponding hash value associated with that packet. For instance, in the case of a networking environment that includes an IP network, the data associated with the packet may comprise an IP source address and IP destination address of the packet to be forwarded. Each of the mapped multiple next hop options for each table entry includes a corresponding threshold value. Thus, to determine which next hop is selected in a packet forwarding operation, a comparison is made between the computed hash value and each corresponding threshold value.
The features of providing the ability for a media-speed, bandwidth conserving network processor device to select from multiple next hop options in a packet forwarding operation and providing the ability to weight the probability of which next hop will be chosen is extremely advantageous.

System using weighted next hop option in routing table to include probability of routing a packet for providing equal cost multipath forwarding packets

International Business Machines Corporation


A thermoplastic composition comprises greater than or equal to about 60 wt. % polycarbonate; and about 10 wt. % to about 40 wt. % of a polyimide; wherein weight percents are based on a total weight of the thermoplastic composition.

Because of their lightweight, durability and strength, engineering thermoplastics can be used for the construction of many components of vehicular interiors, including train cars and aircraft. Components such as wall panels, overhead storage lockers, serving trays, seat backs, cabin partitions, and the like, can be conveniently and economically fabricated by, for example, extrusion, thermoforming, injection molding, and blow-molding techniques.
Interior components of train cars and aircraft are regularly subjected to impacts of varying intensities from equipment and luggage. It is very desirable that engineering thermoplastics used for fabricating such parts exhibit impact strength. It is also desirable for the interior components to be manufactured with the desired aesthetic appearance, such as gloss, texture, color effects, and the like. Additionally, interior components must meet the government and transportation industry safety standards for flammability, smoke, and toxicity.
Accordingly, there is a need in the art for a flame resistant thermoplastic composition having impact strength and good aesthetics.

Thermoplastic composition, articles thereof, and method of making the articles


Target word recognition includes: obtaining a candidate word set and corresponding characteristic computation data, the candidate word set comprising text data, and characteristic computation data being associated with the candidate word set; performing segmentation of the characteristic computation data to generate a plurality of text segments; combining the plurality of text segments to form a text data combination set; determining an intersection of the candidate word set and the text data combination set, the intersection comprising a plurality of text data combinations; determining a plurality of designated characteristic values for the plurality of text data combinations; based at least in part on the plurality of designated characteristic values and according to at least a criterion, recognizing among the plurality of text data combinations target words whose characteristic values fulfill the criterion.

Since the advent of Internet technology, information growth has been explosive. Information retrieval, information analysis, and machine translation are important technologies for making effective use of the information. Automated Chinese language word segmentation is a fundamental technique for the processing of Chinese language information. One difficulty that influences the effectiveness of automated word segmentation is the recognition of previously unlisted words. Unlisted words refer to words yet to be recorded in the word segmentation dictionary. Unlisted words can be divided into two types. One type is words that cannot be listed in dictionaries in their entirety, but for which it is possible to summarize patterns (such as personal names, institutional names, etc.); the other type is new words that should be listed in the dictionary, but have yet to be listed. Among these new words, some are target words that should be listed in the segmentation dictionary, while others are not words, that is to say, they are non-target words that should not be listed in the dictionary.
When recognizing newly appeared words, first a determination must be made as to whether these newly appeared words are words or not, specifically, whether the newly appeared words are target words or not. Currently there are three typical approaches for making the determination: a rule-based method, a statistics-based method, and a method that combines rules and statistics. The most popular statistics-based method is generally to collect statistics with regard to one or several characteristic values of words to be recognized based on large-scale text data, and, based on the statistical results, manually set a threshold value. When a word to be recognized exceeds the established threshold value, the word is determined to be a target word.
However, with the widespread use of the Internet and in an environment when the volume of text data that appears on the Internet is very large, there is already a lack of complete semantic sentence patterns just for the accumulation of certain keywords. For example, on e-commerce websites, and particularly on consumer-to-consumer or customer-to-customer (C2C) e-commerce websites, there can be a massive number of product headers. A large number of these keywords are newly appeared words; however, at this time, the statistical distributions for these newly appeared words tend to be non-linear. When recognition is performed, the results obtained by setting a single threshold value with regard to characteristic values and then determining whether or not the newly appeared words are target words according to the single threshold value are often inaccurate. Thus, the conventional statistics-based method of deciding whether or not words to be recognized are target words is often not well suited for target word recognition in current network applications.

Recognition of target words using designated characteristic values


An electrostatic dust precipitator (1) is constructed mainly to include a housing (11) in which an air path (10) communicating between an inlet (8) and an outlet (9), an airstream generating unit (14) that causes generation of an airstream in the air path (10), a discharging unit (2) and a discharge guide unit (3) that charge fine particulate (103) with a corona discharge (100), a charging unit (4) that causes the fine particulate (103) charged with the corona discharge (100) to repel in accordance with a coulomb force, an attracting unit (5) that allows the fine particulate (103) to be attracted in accordance with the coulomb force and that thereby collects the fine particulate (103), a voltage supply unit (15) that supplies a discharge voltage for generation of the corona discharge (100) and for repelling by the charging unit (4) in accordance with the coulomb force, and a drive controller unit (20) that causes rotational driving of discharge plates and attracting plates.

Conventionally, there are cases where, before emitting of so-called "industrial waste gases", such as exhaust gases of boilers in factories and smoke massively emanated from power generating plants, into the atmosphere, air purification processing is performed to remove various types of fine particulates contained in the industrial waste gases, such as mist and dust containing, for example, powders containing oil, moisture, and/or the like, which can pollutes the atmosphere. Direct emission of the industrial waste gases containing the fine particulate into the atmosphere significantly affects the global environment, so that there are cases where it is obligatory to perform collection thereof by standards of a nation or local governments. In addition, in municipal regions, air pollution resulting from, for example, automobile exhaust gases, is a serial issue, and thus even ordinary homes have and use an air cleaning apparatus. Further, in many sites, such as kitchens of restaurants, there are air cleaning apparatuses for cleaning air before emitted to the outside, for example, polluted air and smoke generated during cooking or the like.
As a dust collector that is used to collect fine particles contained in polluted air which causes air pollution and to carry out purification to clean air, there are known various types classified according to a dust collection principle. More specifically, in term of the collection principle, the apparatuses can be classified into types, such as filtration, gravitational, inertial, centrifugal, dust precipitation, and washing types. They are appropriately selected for practical use depending on, for example, the size and type of fine particulate to be collected, and/or the installation conditions of the apparatuses. In particular, of the types described above, the filtration type (using a bug filter or the like) and the dust precipitation type are excellent from the viewpoint of the dust collection capability, and thus they are widely used in various industrial fields.
The dust collection principle of electrostatic dust precipitators is such that electric charges are supplied to the fine particulate through corona discharges generated from discharge electrodes, and coulomb forces are used to electrostatically attract the charged fine particulate onto collector electrodes which are opposed electrodes, whereby the fine particulate is collected. As features, the electrostatic dust precipitator has significant advantages, such as: 1) the pressure loss is small; 2) a large amount of gases is can be processed; and 3) the collection efficiency is high. Therefore, electrostatic dust precipitators are used in such environments as factories and power generating plants which emit a large amount of polluted air.
Generally, a main construction of an electrostatic dust precipitator includes discharge electrodes each formed into a shape having a large surface curvature, such as a needle or wire material, for generating corona discharges for supplying electric charges to the fine particulate; collector electrodes, as opposed electrodes, each formed into a flat plate for collecting the charged fine particulate; a rectifier unit for rectifying the flow of gas streams in the electrostatic dust precipitator; a dust removal device (dry type) or a spray device (wet type) for separating deposited fine particulate from the collector electrodes; a hopper for collecting the separated fine particulate; and a power system and electric charge control device provided as appendages to cause corona discharges. The dust removal unit is used with a dry electrostatic dust precipitator and is used in such a manner that the collector electrodes are rapped by a hammer or the like to dislodge collected fine particulate therefrom, thereby to store the fine particulate into a collection unit, such as a hopper, provided in a lower portion. In the wet type, fine particulate collected onto the collector electrodes is washed and removed with injected cleaning solution, such as water. In a state where a large amount of the fine particulate is collected onto the collector electrodes, the coulomb force for attracting the charged fine particulate may be reduced, thereby reducing the collection efficiency. Therefore, in order to prevent the case where the dust collection cannot be performed in a stable state, the dry and wet types are used to remove the fine particulate from the collector electrodes.
In addition, in recent years, there has been deployed an apparatus of the type in which discharge electrodes and collector electrodes are housed in a cartridge so that the cartridge is replaceable. According to this type, when a large amount of the fine particulate has been deposited onto the collector electrodes to the extent of reducing the collection efficiency, the collection efficiency can be maintained constant by replacement of the cartridge. In many cases, used cartridges undergo removal of the fine particulate in, for example, dedicated facilities installed in a maker, to be reusable. Thereby, the maintenance operations of apparatuses are facilitated; and in addition, since removal facilities such as described above need not be provided, the apparatus can be downsized. Consequently, the manufacturing cost can be reduced.
However, as already described, in the case of dry and wet electrostatic dust precipitators, there is a tendency to be enlarged in size, so that installation places therefore have been often restricted to, for example, large factories and power generating plants. In the case of the cartridge type, in an environment where a large amount of polluted air is processed in a batch, whenever collection efficiency falls, the replacement of the cartridge has to be frequently done, whereby operator's labor burden, replacement costs, and the like increase, therefore potentially making the processing uneconomical. Further, there has been a demand for an electrostatic dust precipitator that has a compact shape installable in a kitchen of a restaurant or the like and that enables it to secure high collection efficiency. In view of the situations as described above, the present applicant invented an electrostatic dust precipitator having a novel configuration and already submitted a patent application therefore (Japanese Patent Application Laid-Open No. 2003-126729).
Accordingly, under these circumstances, an object of the present invention is to provide an electrostatic dust precipitator that is formed into a compact shape and hence installable even in a narrow place and that has low probability of reducing the collection capability of collecting the fine particulate and generation efficiency of corona discharges even during and after a long-time operation.


A camera changeable between an ordinary photographic mode and a flash photographic mode includes a light source identifying device for identifying the illumination light provided from a fluorescent lamp based on an output from a light measuring device. The light source identifying device is detects ripple components of the output from the light measuring device to provide a flash control signal if the detected ripple components are higher than a predetermined level. The camera is changed into a flash photographic mode in response to the presence of the flash control signal in spite of the brightness of the subject field.

The present invention relates to a camera equipped with an automatic white balance controller which can provide well color balanced images of a subject even under fluorescent light.
Numerous electronic cameras, such as electronic still cameras or video cameras, are generally equipped with automatic white balance controllers. Such a camera with a white balance controller can provide a recorded image with a natural tone of color. The automatic white balance controller, provided with an image sensor such as charge coupled devices (CCDs), detects a color temperature of incident light and corrects image signals of three primary colors according to the detected color temperature.
The color temperature detection ability of such an automatic white balance controller is lowered depending upon illuminance if, in particularly, it receives a small amount of light. This leads to an insufficient white balance control. For more efficiency, there is proposed a white balance controller such as disclosed in, for example, Japanese Unexamined Patent Publication No. 62-159,595, in which white balance is adjusted according to a predetermined or selected standard color temperature when illuminance is at a too low level.
However, it is hard to effect sufficiently the control of white balance according to the color temperature of actual incident light if illuminance is too low even in the above noted white balance controller. In particular, in the case of the using of an electronic still camera indoors under the illumination of a fluorescent lamp or lamps, illuminance is certainly always insufficient. The automatic white balance controller accordingly can not often perform white balance control sufficiently for the case of illumination by fluorescent lamps, which generally have a relatively deep tincture of blue and which is necessary to be controlled in white balance.

Camera automatically operable in a flash photographic mode for providing color-balanced images


A pit lid assembly is formed for a subsurface aircraft servicing pit and includes a lid frame formed with a flat, upper deck, a pit access opening surrounded by the deck, and a hinge pocket defined in the structure of the frame. The hinge pocket extends radially outwardly from the pit access opening and defines mutually opposing and mutually parallel pocket side walls. The pocket has a floor and an end wall slopes upwardly from the pocket floor at an obtuse angle relative to the surrounding flat deck of the frame. A pit lid is seated in the frame upon a bearing ledge formed about the periphery of the access opening. The pit lid has a hinge leaf projecting outwardly away from the access opening. Straight, narrow, linear bores are defined through the structure of both the hinge frame and the hinge leaf. These bores are in coaxial alignment with each other and reside in a horizontal plane located beneath the level of the flat, upper deck of the structure of the frame and above the level of a moisture barrier seal set into the underside of the pit lid. A hinge pin is inserted into the coaxially aligned bores in both the hinge frame and the hinge leaf. The structure of the hinge pin extends entirely through the hinge leaf and into the adjoining structure of the hinge frame. The pit lid may thereby be raised and lowered by rotation about the hinge pin, which is located beneath the surface of the surrounding deck of the frame.

1. Field of the Invention
The present invention relates to a heave duty hinge for an aircraft service pit lid assembly that is used to provide access to subsurface pits located beneath airport runways, docking areas, and other surfaces across which aircraft travel.
2. Description of the Prior Art
At airports and airfields throughout the world, aircraft ground support electricity, air conditioning, fuel, and other aircraft servicing necessities are provided from pits located beneath the surfaces across which the aircraft travel. These pits provide subsurface terminations for aircraft servicing facilities such as fuel lines, electrical power supply lines, air conditioning ducts, and other auxiliary services which are provided to aircraft that are on the ground. The use of subsurface pits serves to reduce the congestion of motorized vehicles and lines running across the aircraft servicing areas that would otherwise exist.
Aircraft servicing pits typically take the form of hollow, fiberglass enclosures that are buried in excavated holes dug beneath aircraft servicing areas. Fuel lines, electrical lines, air conditioning lines and other ground support auxiliary service lines are typically laid down during the construction of the airport or aircraft terminal in trenches that are ultimately filled in. These lines run from the terminal facility to the aircraft servicing pits and are accessible through aircraft servicing pit lid assemblies that are located at the upper entrances to the pits. The pit lid assemblies employ surrounding frames in which pit lids are mounted by hinges for upward rotation about horizontal axes of rotation.
In some conventional subsurface aircraft service pit lid assembly arrangements the hinges are located atop the frame and protrude upwardly above a flat deck forming the upper surface of the frame. While quite convenient and easy to construct, upwardly projecting hinge assemblies have significant disadvantages. The are highly susceptible to damage by snow plows and ground support vehicles traveling over the pit lit assemblies. Consequently, it is currently more common for pit lid hinge mechanisms to be located within the pit and below the flat, upper surface of the deck surrounding the pit opening.
While locating the pit lid hinge assembly within the pit itself avoids the problems associated with exposed pit lid hinge assemblies, conventional hinge arrangements of this type present other problems. Conventional pit lid hinge assemblies that are located within the confines of a pit are expensive and relatively complex in construction. They typically involve spring mechanisms and multiple lever arms that can become fouled or broken over time. Furthermore, the use of conventional subsurface hinge assemblies located within the confines of the pit itself presents an obstruction to access to the lines terminating within the pit. A portion of the access opening is necessarily blocked by such a hinge mechanism, thus making it more difficult for ground servicing personnel to enter or reach down into the pit. Also, these obstructions can cause injury to ground servicing personnel as then enter or leave the pit through the access opening.
The present invention involves a subsurface hinge assembly for an aircraft servicing pit that avoid the problems associated with both hinge assemblies the protrude from the upper surface of the lid frame and also hinge assemblies located within the pit itself. The hinge assembly for a pit lid according to the present invention provides a hinge pin located beneath the surface of the upper deck of the frame, but without occupying any space within the pit access opening itself. The pit lid hinge mechanism of the invention provides full clearance to personnel entering or reaching into the access opening within the frame. There is no spring mechanism obstructing entry into or egress from the pit enclosure, and there is no mechanism that occupies any space within the pit enclosure itself.
In one broad aspect the invention may be considered to be an aircraft pit lid assembly comprising a frame with a flat upper deck and defining a hinge pocket recessed beneath the deck, a lid having a flat upper surface with a hinge leaf projecting laterally outwardly from the lid, and a horizontally disposed hinge pin inserted transversely through the hinge leaf and which extends into upright pocket side walls in the recessed pocket in the frame. The horizontal hinge pin thereby form a horizontal axis of lid rotation relative to the frame that lies below the surface of the deck.
The frame is adapted for installation into a surface across which aircraft travel. The frame defines a frame access opening therethrough entirely within its structure. The access opening is surrounded by the flat, horizontal deck. A recessed bearing ledge beneath the deck encompasses the access opening. The hinge pocket that is recessed beneath the deck lies adjacent the access opening and has opposing, mutually upright pocket side walls extending downwardly from the deck. A hinge pocket floor is located between the upright pocket side walls and lies beneath the level of the deck. The pit lid itself has a flat upper surface and is formed of a size and shape that fits within the lateral confines of the deck to rest upon the bearing ledge.
The structure of the frame is bounded by a peripheral edge which extends a short distance vertically downwardly from the deck located therewithin. A straight, laterally extending bore is defined into the peripheral edge and into the structure of the frame parallel to and beneath the deck. The straight bore extends transversely across the hinge pocket so as to intersect the upright pocket side walls. A straight, transverse bore is also defined through the hinge leaf itself. The bores in the structure of the frame and through the hinge leaf are in coaxial alignment with each other. The hinge pin is thereby installed by insertion into the bore in the structure of the frame through a bore opening in the peripheral edge of the frame. The bore may extend entirely through the structure of the frame to thereby form a pair of bore openings at transversely separated locations on the peripheral edge of the frame. Alternatively, the bore may terminate within the structure of the frame and thereby form a single bore opening into the peripheral edge.
In most subsurface pit installations, the top opening of the pit is equipped with a pit liner that defines a flat, upper frame seating surface that extends about the periphery of the pit, and an upwardly projecting rim that forms the outer boundary of the seat for the pit lid frame. The frame of the pit lid assembly is lowered into position to rest upon the frame seat of the pit liner. The rim thereupon surrounds the peripheral edge of the structure of the frame and confines the pit lid frame therewithin. The rim resides in close proximity to the peripheral edge of the pit lid frame. Normally it resides in contact therewith throughout the entire circumference of the peripheral frame edge.
There is really no laterally acting force of any consequence that would tend to push the hinge pin longitudinally within the straight bore within the structure of the lid frame. Nevertheless, the upwardly projecting and surrounding rim of the pit liner effectively blocks the bore opening or openings in the peripheral edge of the frame, and thereby prevents the hinge pin from shifting in either direction along the longitudinal axis of lid rotation once the lid assembly has been seated in the pit liner.
It is important for the pit lid to have a moisture barrier seal at the access opening. In the absence of such a seal, the pit is likely to fill up with dirt and debris that would wash down into the pit access opening during rainy weather or with melting snow. To preserve the integrity of the seal it is highly desirable for the seal to make contact with the lid frame only at the last instance of closure, so that friction between the seal and the surrounding frame is reduced to a minimum.
This objective can be achieved with the pit lid assembly of the invention by forming the pit lid with a perimeter having a seal mounted thereon. The seal forms an enclosed loop that resides in a horizontal sealing plane that seals the pit access opening throughout its entire circumference when the pit lid rests upon the bearing ledge. The hinge pin and the horizontal bore into the structure of the pit frame in which the hinge pin is located, reside in a horizontal plane that is located between the sealing plane and the deck. By locating the hinge pin and the axis of hinge rotation between the sealing plane and the deck, the seal will leave contact with the frame with the first movement of lifting the lid from a closed position. There is therefore very little friction between the seal and the frame as the pit lid is opened and closed. Nevertheless, since the seal does establish contact with the frame at the final instant of closure, the necessary moisture sealing of the access opening is achieved.
Preferably the hinge pocket has an inclined end wall remote from the access opening. The hinge pocket end wall extends between the pocket side walls and is inclined at an obtuse angle, preferably about one hundred twenty degrees, relative to the deck of the pit lit assembly frame. The hinge leaf has a flat upper surface the meets the hinge pocket end wall in surface-to-surface contact when the pit lid is rotated upwardly about the axis of lid rotation to a maximum extent away from the access opening. This construction has several advantages.
The pit lid hinge leaf must have a thickness less than the thickness of the pit lid itself. By making the hinge leaf with a flat upper surface and by locating the hinge pin such that the flat upper surface of the hinge leaf meets the hinge pocket end wall in surface-to-surface contact throughout, a line of stress across the neck of the hinge leaf is avoided. Such a line of stress could result in a fracture of the hinge leaf with repeated use over time, breaking it at its junction with the pit lid. The transition between the hinge leaf and the pit lid is preferably curved so as to provide further strength and avoid a potential fracture line across the hinge leaf.
Another advantage of constructing the hinge leaf and the hinge pocket with flat surfaces that meet in face-to-face contact is that when the pit lid is opened, the flat upper surface of the hinge leaf approaches the hinge pocket end wall in such a manner as to squeeze out debris that may have collected in the hinge pocket between the inclined end wall and the hinge leaf. At airports there is a very significant amount of airport dirt formed of rubber, weeds, and jet fuel. This material accumulates in virtually any recessed surface at the airport, and tends to collect in crevices and cracks. Consequently, there is a considerable likelihood that airport dirt will collect in the hinge pocket at the hinge axis where the hinge leaf is connected by the hinge pin to the pit lid frame.
Preferably the surface of the hinge leaf is flat and meets the end wall surface of the hinge pocket in face-to-face contact throughout as the pit lid is opened to a maximum position at an obtuse angle relative to the plane of the deck of the frame. By constructing the hinge assembly so that the upper surface of the hinge leaf meets the end wall of the leaf pocket in a surface-to-surface contact, a self-cleaning hinge joint is created. That is, as the hinge leaf opens and the angle between the approaching upper surface of the hinge leaf on the stationary end wall of the hinge pocket grows smaller, the airport dirt is squeezed out of the diminishing space between the hinge leaf and the pocket end wall. Since many aircraft service pit lid assemblies remain closed and are not accessed for long periods of time, this self-cleaning feature is important, since it prevents the hinge joint from becoming jammed after a prolonged period of nonuse.
The hinge assembly of the invention is very advantageous because it does not occupy any space within the enclosure of the pit. Rather, the hinge mechanism is set into the structure of the frame at the hinge pocket defined therein.


An activated sludge sewage treatment process wherein sewage is received into a sewage treating basin in first zone into which activated sludge is mixed and retained for a period sufficient to form a non-bulking sludge and absorb biodegradable dissolved compounds into the activated sludge, and aerated and subjected to a quiescent condition to permit settling of the sludge in a zone characterized in that it has less than approximately twenty percent of the biochemical oxygen demand of the original sewage and where in the sludge is non-bulking, decanting treated sewage from the upper portion of the basin after allowing the sludge to settle, and cyclically repeating the process, anaerobically fermenting the influent sewage, and recycling anaerobically fermented partially treated sewage to the input of the influent sewage is disclosed.

The following abbreviations as used throughout the following specification and in the claims have the meanings stated therefor.
BOD Biochemical Oxygen Demand.* PA0 COD Chemical Oxygen Demand.* PA0 COD.sub.C Colloidal chemical oxygen demand.* PA0 COD.sub.T Total chemical oxygen demand.* PA0 COD.sub.S Soluble chemical oxygen demand.* PA0 DO Dissolved Oxygen content.* PA0 MLSS Mixed Liquor Suspended Solids.* PA0 NH.sub.3 -N Ammonia Nitrogen.* PA0 NO.sub.3 -N Nitrate Nitrogen.* PA0 OUR Oxygen Uptake Rate, mg/gm VSS. PA0 PO.sub.4S Soluble Phosphate.* PA0 PO.sub.4T Total Phosphate.* PA0 HRT Hydraulic Retention Time, the residence time of a given batch or lot of sewage in a particular zone or system, expressed in minutes and hours. PA0 SS Settled Sludge.* PA0 SSV Sludge Settled Volume. PA0 TKN Total nitrogen as determined by the Kjeldahl method.* PA0 VSS Volatile Suspended Solids.* FNT * Concentrations expressed in milligrams per liter, mg/L, unless otherwise stated.
In treating wastewaters containing ammonia, it is known that certain aerobic autotrophic microorganisms can oxidize ammonia to nitrite and that nitrite can be further microbially oxidized to nitrate. This reaction sequence, viz., oxidation of ammonia to nitrate, is known in the art as nitrification and the responsible microorganisms are: Nitrosomonas and Nitrobacter. More specifically, Nitrosomonas are known to oxidize ammonia to nitrite in aqueous systems in which (1) dissolved oxygen levels are in excess of approximately 0.5 mg/l (as disclosed in H. E. Wild et al., "Factors Affecting Nitrification Kinetics," J. Wat. Pollut. Cont. Fed., 43, 1845-1854 (1971)) and (2) free ammonia in solution is held below about 10 to 150 mg/l (as disclosed in Anthonisen et al., "Inhibition of Nitrification by Ammonia and Nitrous Acid," J. Wat. Pollut. Cont. Fed., 43, 835-852 (1976)). Nitrosomonas microorganisms are ubiquitous in the environment, and seed for the development of a Nitrosomonas population in a sludge is therefore available from a wide variety of sources. Both Nitrosomonas growth rates and their ammonia-nitrogen oxidation reaction rates are a function of solution temperature, pH and dissolved oxygen levels. For example, a reaction rate of about 2.4 mg nitrogen oxidation per mg of microorganism per day at a temperature of 20.degree. C., a pH of 7.0 and a dissolved oxygen level of between 1 and 2 ppm has been reported. (See G. M. Wong-Chong, "Kinetics of Microbial Nitrification as Applied to the Treatment of Animal Wastes," Ph.D. Thesis, Cornell University, 1974.)
Further, Nitrobacter are known to oxidize nitrite to nitrate in aqueous systems where the dissolved oxygen level is in excess of approximately 0.5 mg/l (see H. E. Wild et al., supra) and free ammonia in solution is held below about 0.1 to 10 mg/l and free nitrous acid in solution is held below about 0.2 to 2.8 mg/l (see Anthonisen et al., supra). Nitrobacter microorganisms are ubiquitous in the environment also and seed for development of a Nitrobacter population in a sludge is therefore available from a wide variety of sources. Both Nitrobacter growth rates and their nitrite reaction rates are a function of solution temperature, pH and dissolved oxygen levels. For example, a reaction rate of about 7.0 mg nitrogen oxidation per mg of microorganism per day at a temperature of 20.degree. C., a pH of 7.0, and a dissolved oxygen level of between 1 and 2 ppm has been reported (see Wong-Chong, supra).
Complete elimination of ammonia entails the oxidation to nitrite and/or nitrate followed by reduction of the nitrite and/or nitrate to nitrogen gas. This latter reduction of the nitrite and/or nitrate to nitrogen gas is generally known in the art as denitrification and the reaction of reduction of nitrite and/or nitrate to free nitrogen is mediated by facultative heterotrophic microorganisms generally of the genera of Pseudomonas, Achromobacter, Bacillus and Micrococcus. These microorganisms are capable of oxidizing organic matter by utilizing oxygen and, in the absence of oxygen, they can use nitrite and/or nitrate, if present. Facultative heterotrophic microorganisms are further ubiquitous in the environment, and seed for development of populations in a sludge is therefore available from a variety of sources. Facultative heterotrophic microorganism growth rates and denitrification reaction rates and a function of solution temperature, pH and ratio of dissolved oxygen to nitrite/nitrate oxygen availability. For example, a denitrification reaction rate of about 0.6 mg nitrogen oxidation per mg of microorganism per day with methanol as an organic at a temperature of 20.degree. C. and a pH of 8 to 9 in the absence of dissolved oxygen has been reported (see R. P. Michael, "Optimization of Biological Denitrification Reactors in Treating High Strength Nitrate Wastewater," M. S. Thesis, University of Vermont, May 1973).
Frequent references are also made in the literature to unexplained nitrogen losses from basically aerobic sludges (e.g., as disclosed in K. Wuhrmann, "Effect of Oxygen Tension on Biochemical Reactions in Sewage Purification Plants" in "Advances in Biological Waste Treatment," W. W. Eckenfelds, Jr. and B. J. McCabe, Eds., Pergamon Press (1963); Barth et al., "Nitrogen Removal by Municipal Wastewater Treatment Plants," J. Wat. Pollut. Cont. Fed., 38, 7 (1966); and D. C. Climenhage, "Nitrogen Removal for Municipal Wastewater," Project No. 72-5-15, Ontario Ministry of the Environment (1975)). It has been speculated that these losses are due either to spurious amounts of "anaerobic" denitrification which occur in random localized "dead spots" in the sludge where dissolved oxygen levels have fallen to zero or to "aerobic" denitrification. In fact, in 1977, the inventor of the invention described and claimed herein speculated that "aerobic" denitrification does occur and is favored by high microbial sludge concentrations, low dissolved oxygen levels of about 1 ppm and a solution pH of 7.0 (see G. M. Wong-Chong et al., "Advanced Biological Oxidation of Coke Plant Wastewaters for the Removal of Nitrogen Compounds," Carnegie-Mellon Inst. of Research Report to the American Iron and Steel Institute, (Apr. 1977)). As a theoretical explanation, Wong-Chong, supra, postulated a porous microorganism particle model with oxygen gradients such that some portion of the core of the basically aerobic particle is anoxic. Others have speculated similarly regarding the existence of "aerobic" denitrification. (See, for example, L. B. Wood et al., "Some Observations on the Biochemistry and Inhibition of Nitrification," Water Research, 5, 543-551 (1981); I. Murray et al., "Interrelationships between Nitrogen Balance, pH and Dissolved Oxygen in an Oxidation Ditch Treating Farm Animal Waste, Water Research, 9, 25-30 (1975); and J. P. Voets, et al., "Removal of Nitrogen from Highly Nitrogenous Wastewaters," J. Wat. Pollut. Cont. Fed., 47, 394-398 (1975)).
The above biologically mediated processes of nitrification and denitrification, and conversion of ammonia to free nitrogen using Nitrosomonas, Nitrobacter and facultative microorganisms are well known. However, there is a large economic incentive for improvements in conventional approaches to treating wastewater containing high levels of ammonia and other contaminants. Research and development to upgrade the performance of biological treatment systems to handle high ammonia strength liquors has been extremely limited and has been basically considered unsuccessful.
With the exception of the speculations discussed above on how "aerobic" denitrification could possibly occur, all of the other prior art basically discredits the serious possibility of controllably achieving simultaneous nitrification and denitrification from a single sludge. In fact, the prior art has basically set forth that nitrification/denitrification conditions are thermodynamically antagonistic and as such, nitrification should be separated from denitrification (see Bishop et al., "Single-stage Nitrification-Denitrification," J. Wat. Pollut. Cont. Fed., 48, 521-531 (1976)).
Numerous possible permutations and combinations, which can be logically considered of multi-reaction step nitrification/denitrification systems, have been postulated in the literature. These, however, have been largely for application to the processing of low ammonia strength municipal sewage waste (see Bishop et al., supra; Climenhage, supra, Barth et al., "Chemical-Biological Control of Nitrogen and Phosphorus in Wastewater Effluent," J. Wat. Pollut. Cont. Fed., 40, 2040-2054 (1968); and J. L. Barnard, "Biological Nutrient Removal Without the Addition of Chemicals," Water Research, 9, 485-490 (1975)). Only two literature references are known (see Barker et al., "Biological Removal of Carbon and Nitrogen Compounds from Coke Plant Wastes," EPA Report EPA R2-73-167 (Apr. 1973); and P. D. Kostenbader et al., "Biological Oxidation of Coke Plant Weak Ammonia Liquor," J. Wat. Pollut. Cont. Fed., 41, 199-207 91969)) in which high strength ammonia containing wastewater was treated and of these only Barker et al., supra, attempted to achieve nitrification and denitrification. All other attempts to achieve nitrification or a combination of nitrification and denitrification, including that of the inventor herein prior to this invention, have been performed on weak-ammonia coke plant wastewater, i.e., wastewater from a coke plant from which a significant fraction of the ammonia has been stripped. High nitrification efficiencies for ammonia-stripped coke wastewater in a one-stage biological reactor with extended solids residence times has been reported (see A. Bhattacharyya et al., "Solids Retention Time--A Controlling Factor in the Successful Biological Nitrification of Coke Plant Waste," Proc. 12th Mid-Atlantic Industrial Waste Conference, Bucknell University, Lewisburg, Pa. (July 1980)).
Further, variable success with a two-stage nitrification-denitrification reactor system on ammonia-stripped coke wastewater has also been reported (T. R. Bridle et al., "Biological Treatment of Coke Plant Wastewaters for Control of Nitrogen and Trace Organics," Presentation at 53rd Annual Water Pollution Control Federation Conference, Las Vegas (Sept. 1980)). Moderate success in nitrifying ammonia-stripped coke wastewater has also been reported by the inventor of the invention described and claimed herein (see Wong-Chong et al., supra). Variable success has also been reported on a two-stage nitrification-denitrification reactor system on ammonia-stripped coke wastewater (see S. G. Nutt et al., "Two Stage Biological Fluidized Bed Treatment of Coke Plant Wastewater for Nitrogen Control," Presentation at the 54th Annual Water Pollution Control Federation Conference, Detroit (Oct. 1981)).
After experimental attempts to biologically treat coke wastewaters containing high ammonia concentrations directly, Kostenbader et al., supra, in experimental work to establish at what ammonia concentrations performance of microorganisms on wastewaters containing cyanide, thiocyanate and COD was affected, concluded that ammonia concentrations in excess of about 2,000 mg/l seriously inhibited the overall performance of biological sludge. In an extremely complex three-stage reaction system (two aerobic stages in series followed by an anaerobic stage), Barker et al., supra, treated high strength coke plant wastewaters for 352 days. Unfortunately, this program led to unsuccessful results. Typical feed ammonia strengths achieved during these experiments were less than 300 mg/l of ammonia (corresponding to about 12-fold dilution of the raw ammonia-containing feed wastewater to be treated) with substantially less that complete nitrification and denitrification. Highest feed ammonia strengths achieved were about 1200 mg/l ammonia (corresponding to a 3-fold dilution with respect to the raw wastewater feed). Treatment at these levels was sustained only for a single two-week period in the entire test program. Highest nitrification and denitrification rates achieved during this relatively high ammonia strength test period were only between 10% and 50%. In view of the results obtained, the project was abandoned.
Good sludge settleability is basic to the proper operation of all activated sludge systems. Activated sludge batch reactor technology can achieve high nitrogen removal through a predominantly co-current nitrification-denitrification reaction environment (Goronszy, M. C., "Single vessel intermittently operated activated sludge for nitrification-denitrification," 51st Wat. Pollut. Cont. Fed. Conf., Anaheim, U.S.A. (1978); Goronszy, M. C., "Intermittent operation of the extended aeration process for small systems," J. Wat. Pollut. Cont. Fed., 51,274 (1979); Goronszy, M. C. and Irvine, R. O., "Nitrification-denitrification in intermittently aerated activated sludge systems and batch systems, Proc. USEPA International Seminar on Control of Nutrients in Municipal Wastewater Effluents, 3, 74-117, San Diego, U.S.A. (1980). In so doing, the biomass is exposed to repeated sequences of varying high and low substrate tension (carbon and oxygen) on both macro and micro scales which affect the metabolic reaction pathways. A high biomass substrate storage capacity, through enzymatic transfer mechanisms, is necessary for the control of many species of microorganisms that can contribute to sludge bulking as well as for effective biological phosphorus removal.
Experiments conducted on biomass grown under substrate gradient loading conditions demonstrated experimentally identical soluble substrate uptake (as BOD) and associated specific oxygen utilization response under equivalent aerobic and anoxic-anaerobic floc-loadings (Goronszy, M. C., Barnes, D. and Irvine, R. L., "Intermittent biological waste treatment systems--process considerations," Water, AlChE Symp. Ser., 44, 129-136, (1980). Floc-loading and soluble substrate removal for various wastewaters relative to biological selectivity and sludge bulking control has been correlated (Goronszy, M. C. and Eckenfelder, W. W., "Floc-loading biosorption criteria for the treatment of carbohydrate wastewaters," Proc. 41st Annual Indust. Waste Conf., Purdue University, Indiana, U.S.A. (1986)).
Up to 95% nitrogen removal performance has been demonstrated in full scale cyclically operated batch facilities using cycles of 3 to 8 hours incorporating up to 50% of the cycle as a feed, non-mix, non-react sequence. The relative air-off fraction and subsequent mixing and aeration sequencing was shown to impact upon sludge settlement. It was also shown that anoxic mixing sequences, where soluble substrate concentration and an associated biomass oxygen utilization rate were low, caused a rapid development of sludge bulking conditions. Cyclically operated activated sludge systems generate satisfactory sludge settlement characteristics when operated for carbon removal and nitrification and denitrification.
Biological phosphorus removal is achieved through the selective growth of phosphate accumulating bacteria through the proper allocation of readily degradable soluble substrate to properly sequenced (temporal or spatial) anaerobic-aerobic reaction conditions. This mechanism is also common to sludge-bulking control requirements where residual soluble substrate availability is a major determining factor to filamentous growth. The major difference between that aerobic removal of soluble substrate results in filamentous sludge bulking control, while anaerobic removal of soluble substrate results in biological phosphorus removal while also providing a mechanism for sludge bulking control. To maintain an efficient balance for the two functions, it is necessary to provide substrate storage capacity to meet maximum intended phosphorus removal. These parameters have a variable inter-relationship due to out-of-phase diurnal variations in soluble organic and nutrient input parameters (FIG. 1).
Introduction of nitrate to the anaerobic zone also impacts upon availability of soluble substrate for storage to the amount of about 5 mg COD/mg NO.sub.3 -N whereby the subsequent aerobic uptake of soluble phosphorus is retarded by the amount of soluble substrate lost for the enzymatic transfer storage reaction. The presence of nitrate also causes an uptake of phosphate concurrently with carbon storage. Other forms of "oxygen" recharge to the anaerobic zone (e.g. H.sub.2 S) should also be avoided. Anaerobic release of phosphate by substrates that are not carbonaceous is deleterious as the release is not accompanied by an equivalent storage which is necessary for the aerobic uptake sequence. Phosphate uptake has been reported with nitrate in solution (Comeau, V. Rabinowitz, B. Hall, K. J. and Oldham, W. K., "Phosphate release and uptake in enhanced biological phosphorus removal from wastewater," J. Wat. Pollut. Cont. Fed., 59, 707-715 (1987). Operation with denitrifying bio-phosphorus storing bacteria means that co-current phosphate uptake and denitrification can take place in an aerobic zone or sequence.
Biological phosphorus removal has been obtained in fill-and-draw activated sludge operation with sequenced operation to provide the aerobic-anoxic-anaerobic reaction conditions (Ketchum, L. H., Irvine, R. L., Breyfogle, R. E. and Manning, J. F., "A comparison of biological and chemical phosphorus removal in continuous and sequencing batch reactors," J. Wat. Pollut. Cont. Fed., 59, 13-18 (1987). Total operating cycle times of 8.6 hours demonstrated typical phosphorus removal of 3.9 mg/L (4.3 mg/L reduced to 0.4 mg/L) and ammonia removal of 10 mg/L (25 mg/L reduced to 15 mg/L). Considerable phosphorus removal scatter was reported with high observations averaging 1.8.+-.0.75 mg/L above a mean of 0.63 mg/L. Manning, J. F. and Irvine, R. L., "The biological removal of phosphorus in a sequencing batch reactor," J. Wat. Pollut. Cont. Fed., 57, 87-94 (1985) showed the causation of sludge bulking in a batch reactor operated for enhanced biological phosphorus removal could be related to the duration of the anaerobic sequence.
Van Niekerk, A. M., Jenkins, D. and Richard, M. G., "The competitive growth of Zoogleal ramigera and type O2IN in activated sludge and pure culture--A model for low F/M bulking," J. Wat. Pollut. Cont. Fed., 59, 262-273 (1987), demonstrated that the actual soluble substrate concentration available to a mixed culture, rather than an average concentration over 24 hours determined the dominance of floc-former growth in that culture. Specifically Van Nickerk showed that the fate of soluble degradable organics (soluble COD) in wastewater was deterministic to the predominance of type O2IN in an activated sludge. Shao, T. J., "The mechanism and design of anoxic selectors for the control of low F/M filamentous bulking," Ph.D dissertation, University of California, Berkeley, U.S.A. (1986) has similarly shown in the impact of soluble COD availability on biological selectivity. The presence of soluble COD and its effect on sludge volume index is graphically demonstrated in FIG. 2. Wanner, J., Ottova, V. and Grau, P., "Effect of an anaerobic zone on settleability of activated sludge," Proc. IAWPR Cont., Rome, Italy 155-164 (1987) showed that the growth of Type O2IN, Sphaerotilus natans and Thiothrix can be effectively suppressed in systems with anaerobic initial reaction zones provided most of the available substrate is removed under anaerobic conditions. They also showed the selection pressure for these organisms was based on differences in metabolism between filamentous and non-filamentous microorganisms implying that there is no need for a substrate gradient in the anaerobic zones although phosphorus climination can be enhanced by providing a compartmentalized anaerobic zone. The need for an anaerobic substrate gradient for the control of Thiothrix filamentous bulking was also demonstrated.
Following the early work of Chudoba et al., (1973) Goronszy (1977) incorporated a biological selector zone into full-scale continuous inflow sequencing batch activated sludge systems using a transverse partial baffle wall at the inlet end of the reaction basin which formed two zones in continuous fluid communication. While effective filamentous sludge bulking control was demonstrated in over 40 facilities (both industrial and municipal) sludge bulking conditions have been shown to occur in a number of municipal systems (Goronszy, M. C., "Nitrogen removal and sludge bulking control in cyclically operated activated sludge systems," Ohio Wat. Pollut. Cont. Assoc. Conf., Akron, U.S.A. (1987).

Biological nutrient removal with sludge bulking control in a batch activated sludge system


The present invention provides a tool assembly unit for coupling a tool and a tool holder including a measuring device which determines the position of the tool with respect to the tool holder, an alignment device coupled to the measuring device which receives the tool holder, a moveable rod slideably disposed on the alignment device and coupled to the tool which moves the tool with respect to the tool holder to a desired position as measured by the measuring device. The tool may be affixed to the tool holder by heat shrinking.

The present invention relates generally to heat shrink tools and more particularly to a device for accurate assembly of a tool to a tool holder by the heat shrink method.
Connecting a tool to a tool holder by the heat shrink method is a well-known process. An example of the general process is described in U.S. Pat. No. 5,311,654 issued to Harold D. Cook on May 17, 1994. The heat shrink process is typically used with a tool holder having a bore for receipt of a tool having a shank. The tool holder is heated to expand the tool holder bore. The shank of the tool is then inserted into the bore. As the tool holder cools, the bore shrinks around the shank holding the shank within the tool holder.
The heat shrink method is an effective method for connecting a tool to a tool holder. However, in most applications, the tool must be precisely mounted within the tool holder or the tool holder cannot be used. It should be appreciated that these tools are typically used in operations that require very precise alignment and positioning. Slight variations in the alignment between tool and tool holder results in the production of defective parts. One of the major disadvantages of known methods for connecting a tool to a tool holder using the heat shrink method is the need to measure each tool and tool holder and the inaccuracy that can result from these repetitive measuring operations. Human error is a significant factor. A worker must measure the tool length and the tool holder length and then adjust the position of the tool to get the appropriate overall length. To reduce human error somewhat, another method employs a pre-qualified measuring rod to determine the appropriate depth of the tool within the tool holder. When this rod wears, the positioning is wrong and resultant tools and tool holders cannot be used. Furthermore, the heat shrink process must be done quickly to avoid down time when changing tools. If the heat shrink method is slow, tool changes will be slow resulting in the overall slowing of the entire operation in which the tool and tool holder are being used.
Accordingly, it would be advantageous to provide a tool assembly unit for rapidly and precisely connecting a tool to a tool holder.
It is an object of the present invention to provide a tool assembly unit for coupling a tool and a tool holder. The unit includes a measuring device adapted to determine the position of the tool with respect to the tool holder, an alignment device coupled to the measuring device and being adapted to receive the tool holder, a moveable rod slideably disposed on the alignment device and coupled to the tool, with the rod being adapted to move the tool with respect to the tool holder to a desired position as measured by the measuring device.
It is another object of the present invention to provide a tool assembly unit for coupling a tool and a tool holder by heat shrinking. The unit includes a measuring device adapted to determine the position of the tool with respect to the tool holder, an alignment device coupled to the measuring device and being adapted to receive the tool holder, a heating device slideably mounted on the alignment device and defining a bore for sliding a tool therethrough with the heating device adapted to be removably mounted on the tool holder for heating the tool holder, a moveable rod slideably disposed on the alignment device and being adapted to be coupled to the tool, with the rod being further adapted to move the tool with respect to the tool holder to a desired position as measured by the measuring device.
It is still another object of the present invention to provide a method for coupling a tool with a tool holder using a tool assembly unit including a measuring device coupled to an alignment device and a moveable rod slideably disposed on the alignment device. The method includes the steps of mounting the tool holder on the alignment device, coupling the moveable rod to the tool, measuring an actual relative position between the tool and tool holder, moving the tool within the tool holder until the actual relative position of the tool relative to the tool holder is equal to a desired position, and removing the tool holder and the tool from the alignment device.
It is still another object of the present invention to provide a method for coupling a tool with a tool holder by heat shrinking using a tool assembly unit including a measuring device coupled to an alignment device having a heating device slideably mounted thereon and a moveable rod slideably disposed on the alignment device. The method includes the steps of mounting the tool holder on the alignment device, heating the tool holder, coupling the moveable rod to the tool, measuring an actual relative position between the tool and the tool holder, moving the tool within the tool holder until the actual position of the tool relative to the tool holder is equal to a desired position, shrinking the tool holder around the tool, and removing the tool holder and the tool from the alignment device.
The subject invention provides many advantages over conventional tool assembly units by providing a tool assembly unit that rapidly and precisely couples a tool and a tool holder. One of the major advantages is reducing or eliminating the need to measure each tool and tool holder, thereby significantly reducing the inaccuracy that can result from these repetitive measuring operations due to human error. Another advantage is that rod wear does not result in improper positioning of the tool relative to the tool holder, thereby reducing cost by reducing the number of resultant tool assembly units that cannot be used. Furthermore, the tool assembly unit of the present invention permits the heat shrink process to be done quickly to avoid down time when changing tools, thus reducing tool change time and encouraging an efficient assembly operation.


Methods and systems for multi-protocol transmissions in shared spectrum are disclosed where an OFDM transmitter is configured to generate transmissions associated with one OFDM technology or protocol using subcarriers of another OFDM technology. Generally, multi-protocol transmissions as described herein may be performed sequentially (e.g. in a time division multiplexing fashion) or concurrently (e.g. during the same or an overlapping time interval). For concurrent transmissions, an OFDM transmitter may be configured to map or assign the different OFDM signals to different subsets of the available OFDM subcarriers such that the data contained therein can be transmitted at the same or during an overlapping time interval. In one application, an LTE transmitter is configured to use different subsets of the LTE subcarriers for concurrent LTE and 802.11 transmissions that can respectively be decoded by LTE and 802.11 receivers.

Orthogonal frequency-division multiplexing (OFDM) has become a key encoding method used by many communications technologies ranging from wireline to wireless technologies. In fact, OFDM use is pervasive, being employed by many technologies including, but not limited to, wired communications, such as Digital Subscriber Loop (DSL), Asymmetric DSL (ADSL) and Very-high-bit-rate DSL (VDSL) broadband access technology over Plain Old Telephone Service (POTS) copper wiring, Digital Video Broadcasting (DVB), Power Line Communications (PLC), ITU-T G.hn for home wiring LANs, telephone modems, DOCSIS—Data Over Cable System Interface Specification for broadband delivery, MoCA—Multimedia Over Coax Alliance home networking, and wireless communications including IEEE 802.11 (e.g. Wi-Fi), HIPERLAN, Digital TV, Personal Area Networks (PAN), and Ultra Wideband Networks (UWB).
OFDM and its multiple access variant OFDMA continue to find increasing applications, for example in 3rd Generation Partnership Project (3GPP)-based wireless networks such as Long Term Evolution (LTE) and Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) networks, but also in IEEE-based networks such as Mobile Broadband Wireless Access (MBWA, also referred to as IEEE 802.20). Next Generation mobile networks are planning to use OFDM as the platform for this new and exciting product evolution, and even the Wireless Gigabit Alliance (WiGig) plans to use OFDM in the 60 GHz frequency band to enable conference room cell sizes to achieve 100 Gigabits per second (Gbps) data rates.
Although these technologies are all based on OFDM, they have significant differences in their technology implementations. OFDM is a digital modulation technique that uses frequency division multiplexing to create multiple orthogonal sub-carriers to carry parallel data streams. Sub-carriers are modulated using conventional modulation schemes such as Binary Phase Shift Keying (BPSK) or Quadrature Amplitude Modulation (QAM) with defined symbol rates enabling multiple parallel data streams to be carried.
The detailed implementations for these various technologies are all quite different, largely driven by channel limitations or restrictions, and desired operational features. For example, 802.11a Wi-Fi employs short 3.2 microsecond (μs) symbols (with 0.4 or 0.8 μs for the cyclic prefix), and 52 carriers spaced at 312.5 kHz to create a high speed data channel capable of withstanding the low dispersion experienced in short reach indoor channels which Wi-Fi Access Points (APs) typically address, while LTE typically employs longer 66.7 μs symbols (or 71.4 μs with the cyclic prefix) with 15 kHz spaced subcarriers to address significant inter-symbol interference issues typical of long reach outdoor cellular channels.
Thus, implementations may differ by symbol time and sub-carrier spacing, but also by many other physical layer parameters including the number of sub-carriers, channel spacing, Fast Fourier Transform (FFT) size, number and operation of pilot tones, convolutional codes employed, Forward Error Correction (FEC) design, sub-carrier modulation schemes, time-interleaving, equalizer operation, and Multiple-Input Multiple-Output (MIMO) operation to name a few. Moreover, with the Medium Access Control (MAC) layer defining how the OFDM based physical medium is used by higher layer applications, OFDM designs are inherently complex and specific to a particular OFDM technology. As a result, the implementation of interworking functions with other OFDM based technologies has proven to be very difficult.
Nevertheless, with the explosion of wireless technologies in unlicensed spectrum such as the Unlicensed National Information Interchange (U-NII) bands managed by the Federal Communications Commission (FCC) in the United States, there is a desire to see upcoming technologies such as LTE work together to share this spectrum fairly with incumbents such as 802.11 (e.g. Wi-Fi) the dominant technology, and provide a positive end user experience. 3GPP and some to come 5G licensed networks will shortly begin trials to offer services in unlicensed bands. License Assisted Access for Long Term Evolution (LAA-LTE or LAA), as the first example, has recently demonstrated cabled operation at Mobile World Congress in March of 2015 using the 5 GHz band. Product rollouts are planned in 2016 and 2017. However, concerns over interoperability of these different technologies have been raised, driven by expectations of wide scale deployment of LTE radios into the unlicensed bands.
Since the FCC first made available spectrum in the 5 GHz band for U-NII operation in 1997, an etiquette protocol for medium access was developed for Wi-Fi systems which can be generalized into three rules:                1. Listen Before Talk (LBT)—Do not use the channel if Radio Frequency (RF) energy above a threshold (e.g. −62 dBm) is detected,        2. Carrier Sense—Do not use the channel if a Wi-Fi preamble (or related pilot tones) is detected, and        3. Virtual Carrier Sense—Do not use the channel while a channel busy timer (e.g. the Network Allocation Vector (NAV)) is counting down to zero.
In Wi-Fi systems, the Clear Channel Assessment (CCA) function employs these simple etiquette rules to ensure that many Wi-Fi devices can share the same unlicensed channel fairly, and avoid transmission collisions which may have deleterious effects to both the interferer and interferee.
With the introduction of new 3GPP-based cellular technologies such as LTE and soon to be 5G into the unlicensed bands, an expanded etiquette will be required. Wi-Fi, as the main incumbent technology, has a defined etiquette. However, Wi-Fi does not address the complexities and requirements of 3GPP systems. Although they both use OFDM and both support a number of common features at the physical layer, 3GPP and Wi-Fi are fundamentally different.
One of the most fundamental differences is synchronization. Wi-Fi operates asynchronously by applying the etiquette rules and sending/receiving packets when the medium is free. In contrast, 3GPP operates synchronously and employs advanced scheduling algorithms to maximize channel utilization, and therefore is not burdened with etiquette rules. As a result, 3GPP is able to carry higher traffic loads efficiently i.e. in a way that maximizes the use of the valuable frequency channel resources.
Because of this and other notable differences in OFDM implementation, 3GPP-based technologies are not currently designed to support a sharing etiquette, such as that which Wi-Fi supports.
Different possible solutions have been proposed so far claiming to have the potential for improving fair sharing. One such proposal includes implementing a power-based LBT detect threshold. With this proposal, the LTE radio would monitor energy on the channel and consider it free if the received signal strength indication (e.g. RSSI) is lower than that threshold. However, this proposal does not address the variability of cell sizes due to unlicensed band interference. Also, in some implementations, the threshold is fairly large (−62 dBm) and limits the cell size. Depending on the channel conditions, there is no guarantee that the LTE radio will detect a transmitted signal above the threshold and this ultimately may result in a higher collision count and lower throughput.
Other proposals contemplate using a Wi-Fi receiver in the LTE radio to monitor and detect Wi-Fi pilot tones and/or transport LTE data using Wi-Fi packets. However, these proposals would involve significant hardware and software development and would not be backward compatible to existing LTE radios currently deployed. Moreover, the proposals combine transceivers which are fundamentally different to try and create a coordinated design. In doing so, it mixes the performance and regulatory aspects of two separate and independent radio transceivers, making the solution extremely complex to design, verify, and have certified since all of the key design parameters such as power control, AGC, power spectral density, PAR reduction techniques, and PA linearization techniques such as digital pre-distortion are now operating on two separate PHY devices.
Accordingly, to address some or all of the drawbacks noted above, there is a need for improved methods and systems to facilitate co-existence in shared spectrum.

Method and system for multi-protocol transmissions


A carriage for an electronic typewriter using a 2-row daisy wheel includes a slant bracket pivotally connected to a rail disposed on a main frame, a vibrator movable upward and downward to the main frame, a take-up wheel and a supply wheel around which the correction tape is wound, a print ribbon cartridge coupled to an upper surface of the vibrator, a hammering device utilizing a hammer lever, a print wheel elevation and rotation device, a print ribbon carrying device driven by commonly using a drive motor and a cam gear, a correction tape up/down and carrying device and a sensing device detecting the carrying condition of the print ribbon and correction tape by sensing a rotation of the cam gear, thereby a simple construction and a reduction in cost can be achieved.

The present invention relates to a carriage for an electronic typewriter, and more particularly to a carriage for an electronic typewriter using a 2-row daisy wheel.
In a typewriter using a 2-row daisy wheel (hereinafter, referred to as a print wheel), there are provided a print wheel elevation mechanism which moves a print wheel upwardly and downwardly in order to type a letter element arranged at the upper and lower rows, a rotating mechanism which rotates the selected letter element to a typing position at the upper or lower position, a hammering mechanism which hits the selected letter element so as to be typed, an initial position determining means which retains the print wheel in a reference position (initial typing position), a print ribbon carrying mechanism which carries a print ribbon as much as a share for one letter, and a correction tape carrying mechanism which carries a correction tape for erasing a mistyped word, and such mechanisms are mounted on a carriage which is movable on a pair of rails fixed in parallel with a platen.
A conventional electronic typewriter is constructed in such manner that an up/down lever is operably connected to a crank shaft of an up/down motor and the up/down lever is connected to a universal shaft of a print wheel drive motor so that a print wheel can be moved upwardly and downwardly upon the drive of the up/down motor and the print wheel can be rotated by the driving force of the print wheel drive motor.
In such a conventional typewriter, there has been some disadvantages in that since a universal joint has to be used in order to transmit the driving force of the print wheel drive motor, the construction of the carriage becomes complicated and at the same time the components may be easily broken by the excessive torque applied thereto Furthermore, the use of the up/down motor resulted in a complicated structure of the carriage, thus giving rise to a cost increase, and there is also a need for a additional structure for retaining an initial typing position because of not being provided the function therefor. Furthermore, in a conventional electronic typewriter, there has also been a disadvantage in that since a hammer of a hammer solenoid is to hit directly a spoke of a print wheel to type, an expensive solenoid only for use in the hammer is required.
Furthermore, in a conventional electronic typewriter, there has been another disadvantage in that a print ribbon mechanism adopts a separate drive motor, so that it is not used in common with a correction tape up/down and carrying mechanism, thereby the whole construction becomes complicated.
Furthermore, in a conventional electronic typewriter, there has been other disadvantages in that since there is not provided an adjusting mechanism for retaining a print wheel in a precise operating position, it is difficult to adjust the operating position of the print wheel when needed.

Carriage device for an electronic typewriter using a two-row daisy wheel


An exemplary method comprises maintaining product data in a computer-readable data store, the product data including a data entry comprising a question and an answer about a product, setting a lifetime date for the data entry, publishing the question and the answer about the product for access by at least one user, and, in response to the lifetime date being reached, automatically hiding the question and the answer about the product from access by the at least one user and designating the data entry for a lifetime review. In certain embodiments, the method further comprises providing, for display, data representative of a graphical user interface configured to facilitate the lifetime review of the data entry by a user, receiving data representative of a renewal of the data entry, and updating the lifetime date for the data entry based on the data representative of the renewal of the data entry.

Enterprises, such as large business organizations, are commonly faced with challenges related to maintaining and managing information associated with products developed and provided by the enterprises. Such challenges may prove to be especially difficult when significant amounts of product data are being managed, when the people associated with the products have different needs and/or are located at geographically diverse locations, when different people are responsible for different data, when different people are allowed to update data, and/or when products change over time.
Data management tools have been developed to address such challenges related to managing electronic product data. However, existing data management tools have limitations. For example, certain conventional data management tools do not adequately manage aging product data and/or do not provide certain information about the product data. As another example, certain conventional product data management tools are aimed at providing information to external customers of an enterprise and do not provide adequate internal support to product teams within the enterprise.

Product data management and workflow systems and methods


An electronic device includes a camera to capture an image, and a processor to input an image acquired by photographing a detergent container into a trained model to acquire detergent information corresponding to the detergent container, and to guide an amount of detergent dispensed based on washing information corresponding to the detergent information. The trained model is a neural network trained using images of a plurality of detergent containers.

The present disclosure relates to an electronic device capable of recognizing detergent information only by photographing a detergent container using an artificial intelligence technology and of guiding an amount of detergent dispensed based on the recognized detergent information.
Artificial Intelligence, which is one field in a computer science and an information technology to study and research a manner allowing a computer to perform thinking, learning, or self-developing, refers to allow the computer to emulate the intelligent behavior of a human being.
In addition, the artificial intelligence is not present in itself, but is directly/indirectly significantly associated with other fields of the computer science. Especially, recently, artificial intelligence elements have introduced into several fields of the information technology, and have been actively attempted to be utilized in solving problems in relevant fields.
Meanwhile, technologies have been actively studied and researched to perceive and learn the surrounding situation using Artificial Intelligence, to provide information desired by the user in a desired form, or to perform a desired operation or function.
Meanwhile, a detergent is used in a washing machine, and it is important to exactly calculate an amount of detergent dispensed to prevent the detergent from being wasted by preventing the detergent from being dispensed in excessively large amount and to sufficiently cleanly wash laundry by preventing the detergent from being dispensed in excessively smaller amount. In addition, Korean Unexamined Patent Publication No. 10-2005-0000095 discloses guiding a proper amount of detergent.
Meanwhile, the detergents have various characteristics depending on manufacturers, goods, product types (low/highly concentrated or general washing machine/drum washing machine). Accordingly, a proper amount of detergent may be varied depending on the type of the detergent. In Korean Unexamined Patent Publication No. 10-2005-0000095, the proper amount of detergent is guided depending on the level of water which is supplied, but proper countermeasures are failed when a different type of detergent is used.
Meanwhile, as disclosed in Korean Unexamined Patent Publication No. 10-2005-0000095, an individual character is recognized from an image captured by a camera, individual characters are combined with each other to constitute a word, and the meaning of the word is detected.
However, according to the above manner, a manner of forming a word through the recognition of the individual character and the combination of the individual characters is not exact.
In particular, the characters shown on the detergent container may be pictured or significantly variously arranged. In addition, the detergent container may be curved or crooked. Further, the angle or distance for photographing the detergent container or the lighting in photographing the detergent container may be varied. Therefore, character recognition may not be utilized in detecting the type of the detergent by photographing the detergent container.


Methods, systems, and apparatus, including computer programs encoded on computer storage media, for query synonym expansion. One method includes receiving a query including a first compound term, and in response to receiving the query, performing the following operations before search results responsive to the query are identified: generating one or more splits of the first compound term, wherein each split divides the compound term into two or more subterms, assigning a score to each subterm of each split, determining an overall score for each split from the scores for the subterms of the split, selecting one or more of the one or more splits according to the overall score for each split, and augmenting the query with the subterms of each selected split.

This application relates generally to the field of information retrieval, and more specifically to the problem of retrieving answers to search queries and to assisting users in revising search queries.
The World Wide Web (web) contains a vast amount of freely available information. However, locating a relevant item of information on the web can be a challenging task. Note that this problem continues to increase as the amount of information available on the web continues to grow.
Search engines can often help users to locate and retrieve a document of interest on the web. However, users often fail to select effective query terms during the searching process. For example, a user may enter the query [web hosting+fort Wayne] when the city of Fort Wayne is usually referred to as Ft. Wayne. Or, a user may enter [free loops for flash movie] when most relevant pages use the term "music," rather than "loops" and the term "animation" rather than "movie." Thus, documents that satisfy a user's informational needs may use different terms than the specific query terms chosen by the user to express a concept of interest. Note that this problem becomes more of an issue as the number of terms in a query increases. For queries longer than three or four words, there is a strong likelihood that at least one of the terms is not the best term to describe the user's informational need.
Hence, there is a need to modify and/or expand user queries to include synonyms for query terms, so that retrieved documents will better meet the user's informational needs.
Unfortunately, solving this problem has proven to be a difficult task. A simple approach is to use pre-constructed synonym information, for example from a thesaurus or a structured lexical database. However, thesaurus based systems have various problems. For example, they are often expensive to construct, and are generally restricted to one language.
A more significant issue is that the applicability of a synonym to a given phrase often strongly depends on the context in which the phrase is used. For example, the term "music" is not usually a good synonym for the term "loops," but it is a good synonym in the context of the example above. However, the context in the example above is sufficiently uncommon that the term "music" is not listed as a synonym for the term "loop" in standard thesauruses. Note that many other examples of contextually dependent non-traditional synonyms can be identified. Hence, even if conventional synonyms can be identified for a term, it may be difficult to identify specific synonyms to use in the context of a specific query.
Other conventional approaches cluster "related words." Such approaches suffer from the drawback that related words are not necessarily synonyms. For example, the words "sail" and "wind" would likely be clustered (because they co-occur in numerous documents); however they are not synonymous. Hence, substituting one for the other is likely to lead to undesirable search results.
Accordingly, what is needed is a method and an apparatus that identifies potential synonyms, and also identifies contexts in which they are applicable.

This patent is subject to a terminal disclaimer.


A thin film transistor (TFT) array substrate includes a TFT including an active layer, a gate electrode, source and drain electrodes, a first insulating layer between the active layer and the gate electrode, and a second insulating layer and a third insulating layer between the gate electrode and the source and drain electrodes, the first insulating layer and the second insulating layer extending in the TFT, a pixel electrode including a transparent conductive oxide material, the pixel electrode being on the first insulating layer and the second insulating layer and being connected to the source or drain electrodes via an opening in the third insulating layer, a capacitor including a first electrode on a same layer as the gate electrode and a second electrode on a same layer as the pixel electrode; and a fourth insulating layer covering the source and drain electrodes and exposing the pixel electrode via an opening.

1. Field
Embodiments relate to a thin film transistor (TFT) array substrate, an organic light-emitting display device including the TFT array substrate, and a method of manufacturing the thin film transistor (TFT) array substrate.
2. Description of the Related Art
A flat display device such as an organic light-emitting display device, a liquid crystal display (LCD) device, or the like includes a thin film transistor (TFT), a capacitor, and wiring for connecting the TFT and the capacitor.
Regarding a substrate used in the manufacture of the flat display device, the TFT, the capacitor, and the wiring are formed as minute patterns on the substrate, and in order to form the minute patterns on the substrate, a photolithography process of transferring a pattern by using a mask may be used.
In the photolithography process, photoresist is uniformly coated on a substrate on which a pattern is to be formed, the photoresist is exposed by using an exposing apparatus such as a stepper, and (in a case of positive photoresist) the sensitized photoresist is developed. After the photoresist is developed, the pattern on the substrate is etched by using remaining photoresist, and after the pattern is formed, unnecessary photoresist is removed.

Thin film transistor array substrate, organic light-emitting display device including the same and method of manufacturing the thin film transistor array substrate


A method for accessing triple play services provided through a server over a network to a portable device, the method comprising: receiving a signal from a user defining respective preference levels for the triple play services; determining a location for the portable device; determining which of the triple play services are available at the location; composing a list of available services at the location, the available services in the list being ordered in accordance with the respective preference levels; and, displaying the list on a display screen of the portable device, whereby the user may access the available services by selecting from the list.

In telecommunications, the term "triple play service" or "triple play" refers to the provision of three services, namely, high-speed Internet, television (i.e., video-on-demand or regular broadcasts), and telephone service, over a single broadband connection by a service provider ("SP"). Triple play service is offered by cable television operators as well as by telecommunication operators. For a telephone local exchange carrier ("LEC"), triple play service is delivered using a combination of optical fiber and digital subscriber line ("DSL") technologies to their residential customer subscriber base. This configuration uses fiber communications to reach distant locations and uses DSL over an existing plain old telephone serve ("POTS") twisted pair cable as last mile access to the subscriber's home. Cable television operators use a similar architecture called hybrid fibre coaxial ("HFC") to provide subscriber homes with broadband, but use the available coaxial cable rather than a twisted pair for the last mile transmission standard. Subscriber homes can be in a residential environment, multi-dwelling units, or even in business offices.
Using DSL over twisted pair, television content is delivered using Internet Protocol ("IP") television ("IPTV") where the content is streamed to the subscriber in a MPEG-2 ("Moving Pictures Expert Group"-2) transport format. With IPTV, digital television service is delivered to subscribing consumers using IP over a broadband connection. On an HFC network, television may be a mixture of analog and digital television signals. A set-top-box ("STB") is used at the subscriber's home to allow the subscriber to control viewing and order new video services such as movies on demand. Internet service is delivered via asynchronous transfer mode ("ATM") or data over cable service interface specification ("DOCSIS"), typically provided as a 10BASE-T (i.e., 10 Mbit/s baseband over twisted pair) Ethernet port to the subscriber. Voice can be delivered using a traditional POTS interface as part of the legacy telephone network or can be delivered using voice over IP ("VoIP"). In a HFC network, voice is delivered using VoIP.
Some service providers ("SPs") also provide Ethernet-to-the-home and fiber-to-the-home networks which support triple play service and bypass the disadvantages of adapting broadband transmission to legacy networks. This is particularly common in green field developments where capital expenditures are reduced by deploying one network to deliver all services.
Triple play has led to the term "quadruple play" where wireless communications is introduced as another media to deliver video, Internet, and voice content. Advances in both code division multiple access ("CDMA") and global system for mobile communications ("GSM") standards, utilizing third generation ("3G"), fourth generation ("4G"), or universal mobile telecommunications service ("UMTS") mobile telephone technologies, allow service operators to provide quadruple play services. The grouping together of services (such as triple or quadruple play) is referred to as "multi-play".
It has been said that the main challenges in offering triple play relate to backend processes and subscriber support. With respect to technical challenges, voice, video and high speed data all have different characteristics and place different burdens on the network that provides access to these services. For example, voice services are greatly affected by jitter, whereas packet loss or packet reordering has a greater affect on video and data services. Using a shared network resource such as cable or DSL requires that the network equipment used employs quality of service mechanisms.
With respect to subscriber support, subscribers are beginning to demand access to their triple play services through whatever device they may be using at a particular location. The services that a subscriber may wish to access at a first location may be differ from the services that the subscriber may wish to access at a second location. In particular, the services available at the first location may differ from those available at the second location. For example, a television equipped with a set-top box may be available at the first location while a cellular telephone may be the only available device at the second location.
With respect to customized user interfaces in general, United States Patent Application Publication No. 2004/0098360 by Witwer, et al., ("Witwer") provides a user-created life portal for viewing and accessing content on the Internet. The platform, referred to as a life portal, is configured by the user to display only content that is of interest to the user, thereby reflecting the personality and life of the user. The content displayed in a life portal is scraped from web sites and is not limited to sites licensed or maintained by the life portal service provider. The content is displayed as a view or a magazine. Views and magazines (content) are stored in life pages. A view is content that is contained in a portlet and is retrieved from a single web site. A magazine is a collection of content, such as article headlines and links, on a particular topic from one or more web sites. All content in a life portal is specifically tailored to meet the targeted interests and preferences of the user and is designed to exclude content not of direct interest to the user. Thus, while systems such as that provided by Witwer may provide interface content that is based on user interests and preferences, they do not provide an adequate user interface for accessing triple play services that may be location and/or technology dependent.
A need therefore exists for an improved user interface for accessing triple play services. Accordingly, a solution that addresses, at least in part, the above and other shortcomings is desired.

Portable contextual menu for triple play service


An electromagnetic and radiation shielding system includes an enclosure shaped to define a room interior which is accessible through a single passageway, and a door assembly for selectively enclosing the passageway. The door assembly includes a frame mounted within the passageway in conductive contact with a metal skin incorporated into the enclosure, a door with a conductive rear face which is adapted to selectively enclose the passageway, and a seal for selectively establishing continuous, peripheral contact between the frame and the rear face of the door when the door is disposed in its closed position. In this manner, the door assembly cooperates with the enclosure to form an electromagnetic barrier around the room interior in all directions. Additionally, both the enclosure and the door are constructed with a layer of radiation-shielding material to form a radiation barrier around the room interior in all directions.

In the healthcare industry, various types of medical devices are designed to emit high-energy electromagnetic radiation in order to diagnose and/or treat patients. For example, diagnostic imaging tools, such as magnetic resonance imaging (MRI) scanners, computed tomography (CT) scanners and X-ray machines, use electromagnetic radiation (e.g., radio waves, X-rays, and the like) to generate images of the human body for diagnostic purposes. Additionally, radiation therapy equipment, such as linear accelerators (LINACs), use high-energy electromagnetic radiation (e.g., X-rays, gamma rays, and the like) to shrink and/or destroy cancerous cells without impinging healthy cells.
Healthcare facilities are typically provided with shielded rooms, or enclosures, which are specifically designed to house such equipment. In this capacity, shielded rooms form a barrier which prevents the penetration of certain types of electromagnetic energy therethrough.
As an example, a radiation shielding enclosure, also known in the art simply as a radiation bunker, is a room which is uniquely designed to prevent the escape of radiation produced by radiation therapy equipment contained therein. In a radiation bunker, a radiation shielding material, such as concrete, lead, steel or a combination thereof, is incorporated into each of the walls, ceiling and flooring of the room so as to fully enclose the room interior. In this manner, the radiation shielding material prevents the escape of any potentially-harmful radiation produced by the radiation therapy equipment into the ambient environment. An illustrative radiation bunker is shown in U.S. Patent Application No. 2018/0258659 to R. L. LeBlanc et al., the disclosure of which is incorporated herein by reference.
As another example, an electromagnetic shielded enclosure, also commonly referred to in the art as a radio frequency (RF) shielded enclosure or electromagnetic interference (EMI) shielded enclosure, is a room which is specifically designed to attenuate RF energy. Typically, in an RF shielded enclosure, an electrically conductive skin (e.g., a metal sheet, meshing, or screen) is incorporated into each of the walls, ceiling and flooring of the room so as to fully enclose the room interior. In this manner, the conductive skin forms a cage-like barrier which blocks the transmission of any electromagnetic energy that may potentially create RF interference with equipment located inside and/or outside the room.
In all forms of shielded enclosures, the passageway, or doorway, serves as the primary means of disruption to the energy shielding barrier. Accordingly, the particular means for enclosing the passageway is of critical importance in ensuring adequate shielding properties.
In radiation bunkers, an enlarged, slab-like door constructed of a suitable radiation shielding material, such as concrete and/or steel, is commonly utilized to selectively enclose the passageway in an overlapping fashion. As such, a fully-enclosed radiation barrier surrounds the room interior in all directions and thereby prevents emission of radiation into the outside environment.
In RF shielded enclosures, an electrically-conductive door is commonly utilized to selectively enclose the passageway. Additionally, a resilient conductive seal is established between the remainder of the shielded room and the peripheral edge of the conductive door. In this manner, a fully-enclosed RF barrier surrounds the room interior in all directions and thereby blocks the transmission of RF energy therethrough. An example of a conductive seal disposed about the periphery of a metal door in order to create an EMI shielded room is shown in U.S. Pat. No. 6,992,246 to C. Christou, the disclosure of which is incorporated herein by reference.
Increasingly, shielded rooms are required to provide both radiation and RF shielding capabilities. In fact, hybrid diagnostic and treatment equipment, such as a hybrid MRI scanner and linear accelerator, or MR-Linac, have grown into prominence in the field. Through a single medical procedure, hybrid equipment of this type is able to engage in diagnostic imaging to identify the presence of any cancerous cells and, in turn, focus high-energy radiation onto any identified cells with great precision as part of a cancer treatment plan.
Commonly, shielded rooms with both EMI and radiation shielding capabilities are designed as two separate enclosures, with one typically nested inside the other. For instance, an EMI shielded enclosure, with a first door assembly, typically defines the immediate periphery of the room interior. A radiation bunker, with its own separate door assembly, is then constructed around the EMI shielded enclosure to additionally provide the room with radiation shielding capabilities.
The construction of a single EMI and radiation shielded room with two independent door assemblies has been found to introduce a number of notable shortcomings.
As a first shortcoming, an EMI and radiation shielded room of the type as described above is operationally inefficient. More specifically, the time required to open and close two independent doors reduces the rate that patients and staff can routinely enter into and exit the room. As a result, patient throughput is significantly compromised.
As a second shortcoming, an EMI and radiation shielded room of the type as described above is relatively complex in construction. Notably, the inclusion of two independently operating doors substantially increases overall manufacturing and installation costs.
As a third shortcoming, an EMI and radiation shielded room of the type as described above is spatially inefficient due to the inclusion of two separate nested enclosures. As a result, shielded rooms of this type typically require either a greater physical footprint or a reduction in the size of the room interior.

Electromagnetic and radiation shielding system