A diagnostic agent for glycometabolic function comprising a glucose derivative of the formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and each represents hydrogen or acyl having 2 to 8 carbon atoms, with the proviso that at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is acyl and R.sup.5 represents X or --NHCOR.sup.6 X wherein X is a radioisotope of halogen and R.sup.6 is arylene or alkylene having 1 to 3 carbon atoms.

1. Field of the Invention
The present invention relates to a diagnostic agent for glycometabolic function comprising a glucose derivative as an active ingredient. In particular, the present invention relates to a diagnostic agent which is useful for indicating the glycometabolic function in a tumor site in various tumor diseases.
2. Background Information
Of energy sources necessary for activity of humans, in particular, glucose is taken up from the blood into cells through the glucose transporter (hereinafter, referred to as GLUT), enters into the metabolic pathway after being converted to glucose-6-phosphate by the action of hexokinase and forms energy-rich phosphate compounds such as adenosine triphosphate (ATP), which are utilized as energy sources in living organisms. Particularly, glucose is the unique and important energy source in brain. It is accepted that the change of GLUT is minor and conversion to glucose-6-phosphate from glucose by hexokinase is the rate-determining step in the glycometabolism in brain tissue. Therefore, diagnosis of glucose metabolism in brain by positron emission tomography (PET) has been conducted using radioactive fluorodeoxyglucose which acts in a manner similar to that of glucose in passage through the blood-brain barrier and in metabolism towards 6-phosphate compounds by the action of hexokinase.
It has been known that, also in cells having abnormality such as tumor cells, necessary energies are provided by glucose and the blood glucose level has a great influence on the glycometabolism. Since, however, changes in both the membrane transport and phosphorylation are more complicated, qualitative diagnosis of the pathological state of tumor by radioactive fluorodeoxyglucose has been considered difficult in spite of the fact that there have been many articles showing positive correlation between growth rate of tumors which is an indicator of malignancy of tumor and hexokinase activity.
It has been well known that 2-F-18!fluorodeoxyglucose (hereinafter, referred to as FDG) acts in a manner similar to that of glucose in the glycometabolic pathway, and it enters into cells with the aid of GLUT and is phosphorylated by the action of hexokinase. It is expected, on the other hand, that 1,3,4,6-tetra-O-acetyl-2-F-18!fluorodeoxyglucose (hereinafter, referred to as AFDG), an acetylation product of FDG, is taken up into cells without the aid of GLUT, hydrolyzed by an esterase to form FDG, which is phosphorylated by hexokinase similarly to FDG taken up into cells with the aid of GLUT. The behavior of them can be schematically shown in FIG. 8. As the result of an extensive study about the metabolic behavior of AFDG and FDG in tumor cells, the present inventors have discovered that a change in hexokinase activity can be detected on the basis of the fact that AFDG is taken up into cells without the aid of GLUT, quickly hydrolyzed by an esterase to form FDG, which is phosphorylated by hexokinase irrespective of extracellular glucose concentration, and successfully completed the present invention.
Thus, the purpose of the present invention is to provide a diagnostic agent useful for diagnosis of glycometabolic function using the compound which is taken up into cells without the aid of GLUT, immediately acts as a substrate for hexokinase and is metabolized in a manner similar to that of glucose and is able to be an indicator for hexokinase activity in the metabolism, particularly to provide a diagnostic agent therefor which is useful for indicating the glycometabolic function in a tumor site in various tumor diseases.

Method of diagnosing pathological state of tumor cells using a diagnostic agent for glycometabolic function


An array of sensors provided on the outside of a tubular string for measuring a property within the tubular string. The array of sensors may include a plurality of connected sensors, wherein at least one of the plurality of connected sensors is at least partially encompassed in a shroud. A snorkel line may extend from the shroud, the snorkel line capable of coupling with a sensor port in a tubular of the tubular string. The snorkel line may establish fluid communication between one of the sensors at least partially encompassed in the shroud and a corresponding sensor port of a tubular in the tubular string.

Wellbore completion involves preparing a well for hydrocarbon production after drilling operations have been conducted. During this phase production tubing may be provided downhole for injecting various fluids or withdrawing hydrocarbon. Stimulation processes may have also been conducted including creating fractures in the formation. During these completion processes packers may be provided to isolate various zones along the length of the tubing and wellbore. These zones may isolate particular areas to facilitate production of hydrocarbon from the fractured portions of the formation.
During the completion phases, it is desirable to measure properties of the fluid, formation or tubing. Accordingly sensors may be provided downhole at various points of the tubing to collect data for processing.


In a method for extinguishing an arc in a gas discharge chamber in which power is supplied to a gas discharge chamber and in which both with a current flow in a first direction and with a current flow in a second inverse direction there is produced a gas discharge, when an arc is identified, the power supply to the gas discharge chamber is interrupted, and residual energy which is in a supply line to the gas discharge chamber and/or in the gas discharge chamber is supplied to an energy store.

Vacuum plasma generators are known in various power classes and with various output signal forms.
In vacuum glass coating, for example, medium frequency (MF) generators having an MF output signal with powers between 30 and 300 kW are used. The MF signal is mostly a sinusoidal signal with frequencies between 10 kHz and 200 kHz. The output voltages may be from several 100 V to over 1000 V. In order to ignite the plasma, the voltages are often very much higher than during normal operation.
In the plasma, brief and also longer-lasting flashovers may occur, so-called arcs, which are undesirable. An arc is generally identified by means of a collapse or decrease of the voltage and an increase of the current, in particular at the output of the generator or at another location in the generator. If such an arc is identified, it must be ensured that it is extinguished as quickly as possible or does not develop completely.
EP 1 720 195 A1 discloses an arc extinction arrangement in a gas discharging device which is operated with alternating current voltage, in particular MF alternating current voltage, having an arc extinguishing device and an arc identification device which controls it, the arc extinction device having at least one controllable resistor which is arranged in series connection in an electrical line which extends from an alternating current voltage source to an electrode of the gas discharging device. As a controllable resistor, a switch, in particular an IGBT, is provided. When an arc is identified, the switches are switched into a conductive state in such a manner that electrical energy is deliberately converted into heat therein. The depletion layer is greatly heated in the IGBT so that only a few arcs can consequently be processed without leading to destruction of the IGBT.

Arc extinction arrangement and method for extinguishing arcs


An extendible stylus includes a body and an extension telescopically engaged with the body. The stylus may be extended to an open position and collapsed to a closed position, where opposite ends of the stylus are farther apart in the open position. A first, internal detent mechanism of the stylus retains the stylus in the open position. A stop mechanism preferably holds the stylus in the closed position. A receptacle, such as a hole in a case of a portable computer, is engageable with the stylus such that a second, external detent mechanism is provided between the case and the stylus to retain the stylus in engagement with the case. The case is provided with a member which engages a groove positioned on one end of the stylus to form the second detent mechanism. When the stylus is being engaged with the case, a force to overcome the first detent mechanism is greater than a force to overcome the second detent mechanism so that the stylus can be engaged with the case before the stylus is moved to the closed position. When the stylus is being disengaged from the case, the force to overcome the first detent mechanism is less than the force to overcome the second detent mechanism, so that the stylus can be extended to its open position before it is removed from the case.

The present invention relates generally to styluses and receptacles therefor, and more particularly to an extendible stylus used for a pen-based computer system.
Computerized personal organizers are becoming increasingly popular. They perform such functions as keeping a calendar, an address book, a to-do list, etc. While these functions can be provided by conventional computer systems, they are more conveniently provided by personal organizers which are relatively inexpensive, small, lightweight, and portable.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a marriage of the power of a general purpose computer with the functionality and small size of a personal organizer. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is commonly housed in a generally rectangular enclosure, and has a dual-function display assembly providing a viewing screen along one of the planar sides of the enclosure. The dual-function display assembly serves as both an input device and an output device. When operating as an input device, the display assembly senses the position and/or pressure of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). When operating as an output device, the display assembly presents computer-generated images on the screen. Users can operate the computers as computerized notepads by moving the stylus across the surface of the screen. The CPU generates a corresponding image on the screen to create the illusion that the stylus is drawing (or "inking") the image directly upon the screen. With suitable recognition software, the "ink" can be identified as text and numeric information. An example of a pen-based computer is the Newton.TM. Personal Digital Assistant (PDA) made by Apple Computer, Inc. of Cupertino, Calif.
Pen-based computers and many other electrical apparatus are portable, and, as such, should be enclosed in durable, functional enclosures or housings. In addition, a pen-based computer includes a stylus for inputting strokes on the display of the computer. The stylus is either stored in a separate area or is attached to the pen-based computer using a variety of methods. The storage area for a stylus is often limited, however, due to the portable size of pen-based computers.
What is needed is a stylus for a portable computer or similar electrical apparatus which is functionally and conveniently retained by the enclosure of the computer, which can be stored compactly and yet is of sufficient size such that it is comfortable to use.


An electronic apparatus having a display is disclosed. The electronic apparatus includes a first main body having a first touch sensor; a second main body having a second touch sensor; a detecting unit that detects whether the second main body is in an open state or in a closed state; and a control unit that controls the first and second touch sensors. When the detecting unit has detected that the second main body is in the open state, the control unit enables the first touch sensor and disables the second touch sensor. When the detecting unit has detected that the second main body is in the closed state, the control unit enables the second touch sensor and disables the first touch sensor.

An electronic apparatus typically includes a first main body and a second main body to be movable with respect to the first main body. The first main body commonly includes a display unit, etc., and a second main body commonly includes a keyboard, etc.
In some of the above-mentioned electronic apparatuses, a display unit provided in the first main body may have a touch sensor. In that case, when the second main body overlaps with the first main body, there is a possibility that the display unit provided in the first main body may be hidden and unable to be operated.
The present disclosure provides an electronic apparatus having a display unit provided in a first main body to be operated as a touch panel when a second main body overlaps with the first main body.

Portable information apparatus having a display


A new Air Responsive Illuminated Pacifier for providing a pacifier having a light source which is activated when an child sucks on the pacifier. The inventive device includes an airtight nipple portion, a handle portion attached to the nipple portion, and a light source and a pressure actuated switch positioned within the handle portion, wherein the switch activates the light source when a child sucks on the nipple portion. A single activation of the light source causes the light source to remain lit for a predetermined time (e.g., 15 seconds). When activated, the light source emits light into a hollow interior cavity of the handle portion. The handle portion is made of a translucent or luminescent material. When the handle portion is made of a luminescent material, the handle portion continues to glow for a substantial time after extinguishment of the light source, thereby enabling a child or parent to easily locate the pacifier in the dark.

1. Field of the Invention
The present invention relates to illuminated pacifiers and more particularly pertains to a new Air Responsive Illuminated Pacifier for providing a pacifier having a light source which is activated when an child sucks on the pacifier.
2. Description of the Prior Art
The use of illuminated pacifiers is known in the prior art. More specifically, illuminated pacifiers heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art illuminated pacifiers include U.S. Pat. No. 4,716,902; U.S. Pat. No. 4,688,571; U.S. Pat. No. D335,929; U.S. Pat. No. 5,007,924; U.S. Pat. No. 4,228,484; and U.S. Pat. No. D245,790.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new Air Responsive Illuminated Pacifier. The inventive device includes an airtight nipple portion, a handle portion attached to the nipple portion, and a light source and a pressure actuated switch positioned within the handle portion, wherein the switch activates the light source when a child sucks on the nipple portion.
In these respects, the Air Responsive Illuminated Pacifier according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a pacifier having a light source which is activated when an child sucks on the pacifier.


Disclosed are a method and a device for dynamically changing the display of a picture according to the degree of tilt of a mobile terminal without any separate key input. The degree of tilt refers to the angle at which the mobile terminal is tilted with respect to a reference plane, and the degree of tilt is calculated using a geomagnetic sensor.

1. Field of the Invention
The present invention relates to a mobile terminal capable of changing the display of a picture according to the degree of tilt thereof using a geomagnetic sensor, and more particularly to a method and device for controlling the display of a picture according to the degree of tilt of a mobile terminal using a geomagnetic sensor.
2. Description of the Related Art
With the increasing use of mobile terminals including personal communication system (PCS) and personal digital assistant (PDA) phones, various functions and services have become available for these devices. Mobile terminals have gone beyond merely being telephones and now integrate a variety of additional functions.
Additional functions included in mobile terminals have brought users greater convenience and efficiency. In relation to those functions, mobile terminals display operational states and various information on their display units. Also, mobile terminals can display fun character images in a standby mode or game images during implementation of a mobile game. Recently, mobile terminals with a swivel display unit can be turned, thus providing a wider display (horizontal mode) and have become popular. When needed, users can swivel the display unit to view an image or data on a wider screen.
However, conventional mobile terminals with a swivel display unit can only display an image in a direction turned according to the direction of the rotation of the display unit. In other words, conventional mobile terminals merely change the display direction of an image or a motion picture according to the direction of the rotation of the display unit, without physically changing the display at the overall tilt angle of the display unit.

Method and device for controlling display according to tilt of mobile terminal using geomagnetic sensor


A head mounted display in which ambient light is used to illuminate a display to at or near the brightness of the scene being viewed when both reach the user's eyes. A small supplemental light source may further be used to increase the range of operation of the display when ambient light levels are insufficient to make the display screen viewable.

This invention relates generally to normalization of head-mounted display brightness to ambient light level brightness. More specifically, the invention describes a method and apparatus for using ambient light to backlight a display panel in a head-mounted display unit.
Head-mounted displays utilize projection techniques or other methods to place information or symbols in or very near the user's field of vision for fast reference or targeting.
Generally, the head-mounted display system is utilized when the user is attempting to monitor both the information on the display, and simultaneously remain vigilant about his environment.
The ambient light levels of the scene viewed by the user may vary as much as 2000 to 1 in brightness. Consequently, for the user to be able to effectively view the image on the display and the scene at the same time, the brightness level of the scene and the image on the display when they reach the eye must be similar, or the user's eyes will not register both. Thus display brightness must be constantly adjusted to compensate for changes in ambient brightness.
Adjustment for the backlight in the past may have been manual, and thus under the user's control, or may have been done by a microcontroller or similar device in conjunction with a light sensor. The disadvantage of the former is that the user must have used some of his/her concentration to adjust the light level of the display image which may in some cases be extremely inconvenient. An electronically controlled backlight does not disturb the user, but requires some form of control algorithm, which has proven to be a difficult control problem.
Use of a backlight for the display has other difficulties. It adds weight to the display regardless of how it is controlled; heating of the user's head is a problem, as is power usage. In many cases, in fact, it has not been possible to mount a light on the head-mounting to compensate for the large range of ambient light changes, without unacceptable power usage and/or excessive weight and heat dissipation on the helmet.
Movement of components and lighting sources off from the head-mounting and transmitting light to the head-mounting via fiber optic cables is another option, but typically this solution restricts movement of the users head and the cables are subject to breaks and misconnections.

Ambient light display illumination for a head-mounted display


A wire electrode for machining a piece by electro-erosion includes a metallic core and a cladding having an alloy of manganese and zinc obtained by simultaneous electrolytic deposition at a thickness between 1 and 40 micrometers. The cladding permits a substantial increase of the machining, particularly rough machining, performance, a considerable deformability of the wire, a high resistance to traction and stability of the cladding over time.

The present invention relates to an electrode in the form of a wire or a rod for machining a piece by electro-erosion, comprising a metallic core and a cladding constituted by at least one other metal.
Such an electrode is described in the document JP 1-78724. It comprises a brass core and a cladding of pure manganese of a thickness of about 1 xcexcm. This electrode permits obtaining precise finishing machining. During rough machining, the cladding is adapted to be completely eliminated from the surface of the wire and thus does not lead to improvement of the machining. When it is sought to obtain greater thicknesses of the manganese layer, the latter gives to the wire too great a rigidity and hardness, which gives rise to problems during production of the wire and prevents good drawing of the wire. Moreover, given that the manganese deposited by electrolysis is in a metastable phase, its surface condition degrades and its adherence to the core decreases with time.
The present invention has for its object to overcome these drawbacks, and the invention is characterized to this end by the fact that the cladding is constituted by at least one deposit of an alloy comprising manganese and at least one second metal selected from the group of metals comprising Zn, Co, Cu, Ag, Fe, Mo, Ni, Se, Sn, W, the deposit having a proportion of manganese comprised between 5 and 85% by weight and a thickness greater than 1 micrometer.
The second metal, in particular zinc, permits obtaining a wire whose external layer is much more easily deformable. There can thus be produced drawn wires whose external layer is several tens of micrometers in thickness. This layer is thus not eliminated during rough machining, but will permit a considerable increase of the rough machining quality. The wire obtained permits stabilizing the layer thus formed, which is accordingly no longer subject to degradation by the manganese with time. The invention also permits increasing the tensile strength of the covered wire because of the presence of manganese in the alloy. The electrode wires thus obtained can be stretched more greatly during machining and accordingly permit obtaining a better geometry on the cut piece and retard rupture of the wire while machining.
According to a preferred embodiment, the deposit is constituted by a binary alloy of manganese and zinc, the proportion of manganese being comprised between 5 and 85%, preferably between 10 and 60% and more preferably between 15 and 40% by weight.
This cladding alloy permits the particularly favorable characteristics of machining performance, deformability, resistance to traction and stability with time.
Preferably, the core has a concentric structure with the copper center and a peripheral layer of brass supporting said deposit.
These characteristics permit very high machining speeds.
The invention also relates to a process for the production of an electro-erosion electrode and is characterized to this end by the fact that a wire or rod forming said core is treated in an electrolytic bath arranged to produce a simultaneous deposition of manganese and at least one second metal selected from the group comprising Zn, Co, Cu, Ag, Fe, Mo, Ni, Se, Sn, W. This process by electrolytic co-deposition permits rapid and precise production at a moderate cost.
Preferably, the electrolytic bath is arranged so as to produce simultaneous deposition of manganese and zinc having a manganese proportion comprised between 5 and 85% by weight, the duration of treatment being determined so as to attain a layer by electrolytic deposit thicker than 1 micrometer.
Preferably, said electrolytic bath is an aqueous solution having the following composition:
monohydrated manganese sulfate in a concentration between 20 and 120 g/l, preferably 30 g/l;
hepta-hydrated zinc sulfate in a concentration between 50 and 80 g/l, preferably 65 g/l;
bi-hydrated sodium citrate in a concentration between 60 and 300 g/l, preferably 170 g/l.
With these characteristics there is obtained a very regular and stable cladding, whilst maintaining a moderate price.
Other advantages will become apparent from the characteristics set forth in the dependent claims and from the description of the invention given hereafter in greater detail with the help of drawings which show schematically and by way of example one embodiment.

Electrode for machining a piece by electro-erosion and its process for production


A spin transfer torque magnetic junction includes a magnetic reference layer structure with magnetic anisotropy perpendicular to a substrate plane. A laminated magnetic free layer comprises at least three sublayers (e.g. sub-layers of 6 to 30 Angstroms of CoFeB, CoPt, FePt, or CoPd) having magnetic anisotropy perpendicular to the substrate plane. Each such sublayer is separated from an adjacent one by a tantalum dusting layer. An insulative barrier layer (e.g. MgO) is disposed between the laminated free layer and the magnetic reference layer structure. The spin transfer torque magnetic junction includes conductive base and top electrodes, and a current polarizing structure that has magnetic anisotropy parallel to the substrate plane. In certain embodiments, the current polarizing structure may also include a non-magnetic spacer layer (e.g. MgO, copper, etc).

Information storage devices are manufactured in high volume and widely used to store and/or retrieve data in computers and other consumer electronics devices. Information storage devices may be classified as volatile or non-volatile, depending upon whether their memory content is maintained when the information storage device is not powered. Examples of non-volatile information storage devices include magnetic hard disk drives and magnetic random access memory (MRAM) devices, either of which may utilize a magnetoresistive tunnel junction (MTJ) as part of information storage or retrieval operations. Specifically, whereas volatile random access memory (RAM) devices typically store data as electric charge, MRAM devices may store data in MTJs that maintain memory content even when the memory device is not powered.
Generally, each MTJ includes a reference layer that has a magnetic orientation that is pinned or fixed, and a free layer having a magnetic orientation that can be changed by an external magnetic field (e.g. from an adjacent disk or generated by a programming current). The MTJ is in a low resistance state when the free layer magnetic orientation is parallel to that of the reference layer, and in a high resistance state when the free layer magnetic orientation is anti-parallel to that of the reference layer. If the external magnetic field and/or programming current required to switch a desired MTJ between high and low resistance states (with acceptable switching speed) is too great, or if the MTJs are arranged too closely together, then one or more adjacent MTJs may undesirably be affected or inadvertently switched.
There have been many patented variations and improvements to MTJs in recent years, some of which help mitigate the foregoing problem to allow for more reliable operation when the MTJs are arranged in close proximity to each other. For example, a spin transfer torque magnetic random access memory (STT-MRAIVI) has been investigated, in which each MTJ is switched (i.e. "programmed") by an application of spin polarized current through the MTJ. The STT-MRAIVI promises significant advantages over magnetic-field-switched MRAIVI, which has been recently commercialized. For example, STT-MRAIVI can be scaled to a smaller size while maintaining the programmability of individual MTJs (without inadvertently and undesirably affecting the programming of adjacent MTJs). Moreover, STT-MRAIVI can be programmed with lesser programming currents, which reduces power consumption and associated requirements for heat dissipation.
However, one of the challenges for implementing STT-MRAIVI is minimizing the programming current required to quickly switch the magnetic orientation of the free layer in the MTJ, while maintaining high thermal stability of the recorded data. Reduced programming current may enable the use of smaller memory cell transistors, which can substantially reduce the overall size of the incorporating memory device. A reduced programming current requirement also corresponds to reduced voltages across the MTJs during writing and sensing, which may decrease the probability of tunneling barrier degradation and breakdown, and thereby improve the endurance and reliability of the incorporating memory device.
Hence, there is an ongoing need in the art for an improved MTJ that can quickly and reliably switch with acceptable thermal stability using a reduced programming current, and that is suitable for high volume manufacture and widespread durable use in reduced-scale data storage devices.

Spin transfer torque tunneling magnetoresistive device having a laminated free layer with perpendicular magnetic anisotropy


The present invention provides a unique method of making a barrier rib structure for a plasma display panel. Instead of employing the traditional screen printing method of making barrier ribs, the present invention employs a section of low temperature cofired ceramic dielectric. The unique method includes the steps of providing a fusible dielectric composition in an organic binder, applying the composition on a glass sheet, applying a photoresist composition, placing a mask over the coated plate to provide a pattern of openings in the photoresist corresponding to the pattern of the picture subcells, using a laser to remove the portions of the coating not covered by the photoresist to form the color subcells and heating the resulting assembly to a sintering temperature to fuse the dielectric composition to form the barrier rib structure and to fuse the barrier rib structure to the glass plate.

Among the large, flat, full color, high-definition television screens or panels currently available, the gas-plasma-type panel has achieved considerable success. These display panels may be hung on a wall, much like a framed picture or the like, and provide excellent display quality, as well as a wide viewing angle. Screens as large as 55" diagonal size have been produced with a thickness of around 1/4 in. While these panels are quite light and thin, they can produce sharp pictures in rooms with only ordinary illumination.
The construction of these plasma display panels is rather complex, particularly in view of the large number of pixels that must be used to achieve the high-definition desired. The panels utilize a pair of parallel dielectric glass plates including a front plate and a rear plate. The plates are separated by a barrier rib structure that serves to define with the two glass plates, a plurality of pixels each of which generally includes 4 individual color subcells arranged in a square pattern. In a typical design, the 4 subcells include a blue subcell, a red subcell and 2 green subcells. Each subcell contains a color phosphor that is activated by an excited volume of gas plasma contained in the subcell. The gas plasma is excited by means of a voltage pulse generated by a control circuit.
The control circuit includes a plurality of electrodes including parallel conductive anode strips that are printed or formed by a thick film technique on the interior surface of the rear glass plate. Correspondingly, a plurality of parallel conductive cathode strips are printed or formed by a thick film technique on the interior surface of the front plate and oriented perpendicular to the anode strips on the rear plate.
A white backing layer is formed on the interior surface of the rear plate to provide a white backing for the phosphors. The individual phosphors for each cell are printed or formed by various other techniques on the white backing layer in a pattern that corresponds to the pattern of the color subcells.
The front plate also has a plurality of color filters in the form of film segments applied to the outer surface of the panel in a pattern corresponding to the arrangement of the color subcells. For example, a red filter segment is positioned over a subcell with a red phosphor, a blue filter segment is positioned over a subcell with a blue phosphor and a green filter segment is positioned over a subcell having a green phosphor. The remaining portions of the outer surface of the front plate have a black film layer applied thereto to form a black matrix that surrounds and encloses the filter segments.
The conventional technique for forming the barrier rib structure so as to partition the color subcells, has been to perform a number of screen prints having the desired barrier rib pattern thereon defined by a layer of fusible dielectric material such as a dielectric thick film material. The thickness of these individual prints may be for example, about 0.02 mm. The height of the color subcells may be for example, between 0.1 mm and 0.2 mm so that 5 or 10 or more individual screen prints would be required to produce the desired barrier rib height.
These multiple screen prints are placed or printed on the interior surface of one of the glass plates (preferably the rear plate) and aligned with one another as well as with the respective front glass plate. The assembly is then fired to fuse the screen patterns to one another and to the interior surfaces of the glass plates.
The accurate alignment of the successive prints and the line definition required over the relatively large area of the surface of the glass plates, are critical to the proper functioning of the plasma display panel. Because the alignment of each print is so critical, the process is quite cumbersome and also vulnerable to error.
The process of the present invention, however, reduces the difficulties indicated above and affords other features and advantages heretofore not obtainable.


A nozzle of a laser processing head for laser cutting and laser welding includes a laser beam outlet for directing a laser beam towards a processing location of a workpiece to be processed, a first gas supply channel for supplying a cutting gas towards the processing location of a workpiece to be processed when the laser processing head is used for laser cutting, and a second gas supply channel for supplying a welding gas towards the processing location of a workpiece to be processed; when the laser processing head is used for laser welding.

In a laser processing system, a laser processing head forms the end of a beam guidance from the laser to the processing location and focuses the laser beam onto the processing location. Laser processing heads contain supplies for working and/or inert gases, and sensors for distance control from the workpiece. The gases are discharged through a nozzle in the laser processing head towards the processing location on the workpiece. Often a laser cutting gas pressure of up to 20 bar is required for laser cutting to discharge the slag from the kerf.
For a laser power of up to approximately 5 kW, a pressure chamber exists in the cutting head through which the laser beam passes and which is sealed by a focusing lens. The cutting of different sheet thicknesses and materials requires different nozzle cross-sections and bores in the nozzle, as disclosed, for example, in German patent No. DE 3037981.
As an alternative to cutting heads with lens optics, cutting heads with mirror optics also have been used. To generate pressure, so-called annular gap nozzles are thereby generally used, which have a separate pressure chamber and which are disclosed, for example in European Patent Applications Nos. EP 0741627 A1 and EP 0989921 A1.
Mirror optics are used almost exclusively for laser welding due to the greater power and smaller gas pressures that are used with mirror optics. Moreover, mirror optics are less sensitive to soiling than lens optics, because laser welding tends to produce more soiling than laser cutting, and because mirror optics can be cooled directly.
Generally when the laser power is low, the gas is supplied concentrically to the processing location, and when the laser power is higher, it is supplied from the side.
Laser processing heads often must be slim due to the three-dimensional tasks they perform and to minimize the disturbing (abutting) contour of the head.
To render the machines more flexible, a universally usable processing head is desired that requires as little manual adjustment as possible, i.e., the following adjustments are eliminated: changing of the processing head when switching between laser cutting and laser welding; changing the nozzle to adjust for different materials and material thicknesses; and adjustment of the separation between workpiece and processing head to the respective processing task. These changes are conventionally realized in most cases through mechanical adjustment, pivoting and tilting mechanisms, through beam setting points or through changing stations, where the processing head or the nozzle are replaced as describe, for example, in European Patent No. EP 0411535.


A process for producing heterocyclic compounds which are useful as pesticides, drugs, fungicidal materials or intermediates thereof. TosMIC is reacted with an aldehyde or an imino compound: 1) in a solvent mixture of an aprotic solvent with a protic solvent in the presence of a base, 2) in the presence of a phase-transfer catalyst and an inorganic base, or 3) in the presence of an inorganic base. Thus, a desired product can be efficiently obtained using a solution without isolating TosMIC which is irritating and unstable, has a low decomposition point and shows explosivity.

A method of using an aldehyde and p-tolylsulfonylmethylisocyanide (hereinafter abbreviated as TosMIC) is generally known as a particularly useful process among those for synthesizing 5-substituted oxazole compounds. Generally, the process involves reacting an aldehyde with TosMIC in methanol in the presence of potassium carbonate. In addition, another known method involves the reaction in dimethoxyethane and methanol in the presence of an ion exchange resin (Ambersep 9000H-) (Tetrahedron Letters, 1972, 2369; Lect Heterocycl. Chem., 1980, (5), SI 11–122; Tetrahedron Letters, 1999, 5637–5638, and others).
Methods for synthesizing 5-substituted imidazoles with TosMIC are also known. Generally, an imino compound is reacted with TosMIC in an alcohol-type solvent in the presence of potassium carbonate (Tetrahedron Letters, 1976, 143–146; J. Org. Chem., Vol. 42 (7), 1997, 1153–1159; Tetrahedron Letters, 2000, 5453–5456; and Tetrahedron, 53 (6), 2125–2136, 1997).
In all of the said processes, TosMIC is handled as crystals. Because of this, complicated isolation procedures including concentration, crystallization, separation of solvents, and drying are required, depending on the conditions, when the compound is produced industrially. Besides, a decrease in TosMIC production yield is unavoidable due to loss of product in filtrates. Furthermore, TosMIC is irritating, unstable and explosive with a low decomposition point. Its isolation should be avoided for safety reasons.
As described above, it is preferable not to isolate TosMIC when safety is taken into account. To handle TosMIC without isolating it, it is inevitable to use the reaction solution itself or a solution of another extract solvent after TosMIC is synthesized and post-treatments are done. It has been essential to develop safer processes for producing 5-substituted oxazoles and 5-substituted imidazoles with TosMIC in a solution without isolating it.

Process for producing 5-substituted oxazole compounds and 5-substituted imidazole compounds


Capsinoids of formula (3) may be conveniently prepared in a high yield, in a short time, without using a dehydrating agent by esterification of a fatty acid of formula (1) with a hydroxymethylphenol of formula (2) using an enzyme without a solvent or in a low-polar solvent. Addition of a fatty acid represented by formula (4) is effective for stabilizing the ester compound of formula (3).

1. Field of the Invention
The present invention relates to method of producing a capsinoid compound by dehydrating condensation. The present invention also relates to a method for stabilizing a capsinoid compound. The present invention further relates to stabilized capsinoid compositions.
2. Discussion of the Background
Capsaicin ((E)-N-(4-hydroxy-3-methoxybenzyl)-8-methyl-6-nonenamide), the pungent ingredient of Capsicum annuum L., has physiological activities such as the suppression of obesity, promotion of energy metabolism, and the like. Due to its extremely strong pungent taste, however, capsaicin can be used only in a limited amount, and cannot be used as a food additive, a pharmaceutical product, and the like.
In recent years, Yazawa et al. have developed and reported a non-pungent cultivar of Capsicum annuum L., CH-19 Sweet, by fixing a non-pungent fruit over the years, which was selected from the fruits of a highly pungent cultivar CH-19, a native of Thailand (see, e.g., Yazawa, S.; Suetome, N.; Okamoto, K.; Namiki, T. J. Japan Soc. Hort. Sci., 1989, 58, 601-607).
CH-19 Sweet contains a large amount of capsinoids, which are free of a pungent taste. These capsinoids include capsiate, dihydrocapsiate, and nordihydrocapsiate, in the order of content, the first being the highest, which have the following structures.

These capsinoids have the same physiological activities as capsaicin and are free of a pungent taste. Accordingly, they may be usable as food additives or pharmaceutical products. However, production of capsinoids with high purity in a large amount from natural sources is limited, and a novel synthetic method for conveniently producing such capsinoids in a large amount has been desired.
To form an ester bond of a capsinoid, it is a general practice to condense vanillyl alcohol and a fatty acid derivative.
Vanillyl alcohol has two reaction sites of a primary hydroxyl group and a phenolic hydroxyl group. Since conventional esterification methods, such as a method of condensing vanillyl alcohol and an acid chloride of fatty acid in the presence of a base (see, e.g., Kobata, K.; Todo, T.; Yazawa, S.; Iwai, K.; Watanabe, T. J. Agric. Food Chem., 1998, 46, 1695-1697), permit reaction of the acid chloride with both the primary hydroxyl group and the phenolic hydroxyl group, the yield of the object capsinoid becomes lower.
For synthesis of capsinoids by a conventional esterification method, therefore, the phenolic hydroxyl group of vanillyl alcohol may be selectively protected. However, this requires protection and deprotection before and after esterification, thus unpreferably increasing the number of steps necessary for the production. Furthermore, such capsinoids are associated with a problem that they are unstable and easily decomposed during deprotection.
As a method for selectively reacting the primary hydroxyl group alone, the Mitsunobu reaction (see, e.g., Appendino, G.; Minassi, A.; Daddario, N.; Bianchi, F.; Tron, G. C. Organic Letters, 2002, 4, 3839-3841) and a method involving the use of LiClO4 (see, e.g., Bandgar, B. P.; Kamble, V. T.; Sadavarte, V. S.; Uppalla, L. S. Synlett, 2002, 735-738) can be mentioned. The former is defective in that triphenylphosphine oxide and reduced diethyl azodicarboxylate occur as co-products after the reaction, which makes purification difficult, and the latter did not permit reproduction of the yield described in the publication, though the experiment was faithfully repeated by the present inventors. Accordingly, neither of them are suitable for industrial practice.
In the meantime, the primary hydroxyl group alone can be selectively reacted by an esterification method using an enzyme. This method is considered to be suitable for industrial practice from the aspects of easily available reagents and convenient steps. Specific examples of the method using an enzyme include a method of condensation of vanillyl alcohol and a fatty acid using an immobilized enzyme Novozym 435 (manufactured by Novozymes), which is one kind of lipase, in an acetone solvent (see, e.g., JP-A-2000-312598). However, since the reaction using the enzyme is an equilibrium reaction with water produced during esterification, the reaction takes a long time and the yield is as low as about 60%. To increase the yield, one of the starting materials may be used in a large excess to shift the equilibrium toward the esterification. However, this approach necessitates a step of separating the starting material remaining after the reaction from the resultant product, making the step complicated. When molecular sieves are added as a dehydrating agent, the yield increases, but only up to about 80%, and the dehydrating agent needs to be removed by filtration. For reuse of the enzyme, the enzyme and the dehydrating agent need to be separated from the cake after the reaction.
Furthermore, capsinoids are unstable and are known to be decomposed by mere dissolution in an organic solvent (see, e.g., Sutoh, K.; Kobata, K.; Watanabe, T. J. Agric. Food Chem., 2001, 49, 4026-4030). Therefore, techniques for stable separation and preservation of the capsinoid after industrial production of the capsinoid, become necessary.

Production method of capsinoid by dehydrating condensation, stabilizing method of capsinoid, and capsinoid composition

Abstract: wherein each symbol is as defined in the specification.


A snubber circuit with two switches which are switched together. The two switches form a pair of active networks with complementary diode locations, and a capacitor is connected to provide a path for transient current through both diodes. The two switches are preferably switched simultaneously to minimize conduction losses. When Switches S1 and S2 are turned off, the voltage through across capacitor Cs is nearly zero. Turning off S1 and S2 causes current flowing through S1 and S2 to be diverted through D1, Cs, and D2. Therefore, the voltage across S1 and S2 is a very low value and consequently, the turn-off losses are low. Alternatively, at the time when S1 and S2 are turned on, the peak current through S1 and S2 is equal to the boost inductor current. Therefore switching losses are minimized and the converter can operate at higher frequencies.

This application is related to power conversion snubber circuits.
Switching power supplies gained popularity in the early 1970s, coinciding with the introduction of the bipolar power transistor. Since that time, many evolutionary changes have occurred to make the switching power supply meet the needs of many diverse applications. The boundaries to these application areas are determined primarily by the amount of stress the power switches (power transistors or MOSFETS) must endure and still provide reliable performance.
Background: DC--DC Converters and Single-Phase Fed AC-DC Converters
Power conversion, such as DC--DC and AC-DC was typically performed by hard-switched, pulse width modulated ("PWM") circuits such as the "boost" power converter shown in FIG. 1. It consists of an input ac source V1, an boost inductor L1, a boost switch S1, a boost diode D1, an output filter capacitor Co, and a load Ro. By varying the switching signal from the PWM controller, the duty cycle of S1 is varied and the output power is thus controlled. This is known as PWM control.
In the conventional boost power converter, when the switch S1 is open, current flows through the inductor L1 and the diode D1. The current flowing through inductor L1 and diode D1 will charge the capacitor C1. When the switch S1 is closed, current from the input voltage V1 will flow through L1 and S1 to the input voltage source. Assuming that there are no losses in the inductor L1 and negligible current drawn by the load, equating the volt-seconds across the inductor L1 to zero, and ignoring the turn-on voltage of D1, the maximum output voltage Vout can be determined from the following relationship: EQU Vout=V1/(1-D);
where D is the duty cycle of the switch.
Thus, assuming that a fixed-frequency switching signal is provided to the controllable switch S1, the higher the duty cycle of the switching signal, the higher the output voltage supplied across the output load Ro.
The above operation of the boost converter is discussed under the constraints that the power switch closely approximates that of ideal switches, i.e. that the transitions from open-to-closed and closed-to-open occur instantaneously. Unfortunately, this assumption is not particularly accurate, and consequently the finite turn-on time and finite turn-off time of the switching element causes switching losses of approximately P.apprxeq.I.sub.switch V.sub.switch.
A further problem is that, when the switch S1 turns off, the rate of rise of voltage dV/dt across S1 creates substantial unwanted radio-frequency interference ("RFI") and electromagnetic interference ("EMI") noise, which significantly limits the power conversion frequency and efficiency, particularly in the multi-kW power range.
In order to increase the power densities of the converters, the operating frequency needs to be as high as possible for any given power level. The biggest problems with conventional hard-switching PWM converters at multi-kilowatt power levels are attributable to diode stored charge, diode reverse recovery, and device switching losses. Therefore, conventional PWM converters operated at higher switching frequencies cause increased switching losses.
Background: Diode Reverse Recovery
Diode reverse recovery in the conventional hard switching boost power factor converter presents a significant limitation because it generates substantial EMI and limits the power conversion frequency and efficiency in multi-kilowatt power range. More specifically, in the conventional hard-switching boost converter of FIG. 1, when switch S1 is closed, the current through S1 increases to the level of the current through the inductor L1. At this point, the current through the diode D1 decreases until the diode D1 no longer conducts. At this time, any charge stored on the diode D1 is removed via switch S1. As the charge is being removed from the diode D1, the current through S1 continues to rise, often to a value of more than twice the inductor current level. The combination of high peak current (dI/dt) and high peak voltage (dV/dt) creates significant unwanted RFI/EMI noise, and considerably stresses the switch S1.
Background: "Soft-Switching" Reactive Snubber Circuits
In response to the problems associated with hard switching PWM power converters described above, designers have proposed the use of reactive snubber networks to "trap" energy that would normally be dissipated during switching transitions, and thereby permitting "soft-switching" of the controllable switch. Soft-switching occurs when little or no voltage appears across the switch and/or when little or no current is flowing through the switch, thereby reducing the switching stresses. Two types of such soft-switching converters are zero current switching ("ZCS") converters (in which turn-on and turn-off of switch occurs with no current in the controllable switch), and zero voltage switching ("ZVS") converters (in which turn-on and turn-off of the switch occurs with no voltage across it).
ZVS is accomplished by employing a purely capacitive snubber having an anti-parallel diode. The capacitor starts at an initial voltage, which places zero volts across the power switch at turn-off, and its voltage cannot be changed instantaneously. With ZVS circuits, turn-on occurs only when the anti-parallel diode is conducting, and turn-off losses decrease with increasing capacitance. Unfortunately, to cause conduction of the anti-parallel diode before turning-on the switch, additional circuitry is required to discharge the capacitor, or an external resistor is required to dissipate the energy stored in the capacitor during turn-on of switching cycle. Therefore, although the controllable switch can operate at elevated frequencies due to ZVS, the power losses are merely shifted from the switch to the dissipating resistor. Furthermore, if a snubber circuit is not properly designed, turn-on and turn-off of the switch itself can cause large current spikes.
On the other hand, ZCS is accomplished generally by employing a purely inductive snubber. The current through the inductor starts at an initial zero condition and lacks the ability to change instantaneously.
To solve the power dissipation problem, designers have developed "loss-less" soft-switching power converters in which the snubber networks are reset by means of inherent circuit operation. These loss-less soft-switching power converters "re-circulate" the energy stored by the reactive snubbers to accomplish loss-less operation. Unfortunately, this way of eliminating spikes requires extra power handling components which add size, weight, and cost to the power conversion system. Moreover, they often severely reduce overall system efficiency since the RMS input current is high.
Resonant Switching Converters
Other known loss-less power converters include resonant and quasi-resonant) switching converters. These converters incorporate reactive elements (capacitors and inductors) in conjunction with the switching device. In the purest sense of the word, resonance implies a continuous function whose waveform is a continuous sinusoidal signal. However, most so-called "resonant" converters are actually quasi-resonant converters--the resonant elements being operated for only one-half of a resonant sine wave at a time. The power switch in a quasi-resonant converter connects the input voltage source to the tank circuit, and is turned on and off in the same step fashion as a PWM switching power supply. The output voltage of these circuits is controlled by varying the operating frequency of the controllable switches. The conduction period (or "on" period) is dictated by the ringing frequency of the tank circuit. The power switch turns off after completion of one-half of a resonant period. A major advantage is that current during turn-on and turn-off is zero, therefore eliminating any switching losses. These circuits advantageously have low semiconductor switching losses and operate with sinusoidal waveforms. Unfortunately, resonant power converters exhibit increased component count, increased switching currents (peak and RMS), and require wide operating frequency variations to maintain a constant output voltage. Thus, resonant switching converters are relatively expensive, require complex switching control circuitry, and eliminate switching losses at the expense of conduction losses.
Modified Boost Power Converter
An example of a known ZVS resonant boost power converter is shown in FIG. 2. Further discussion regarding this circuit may be found in "Analysis and Design of a zero voltage transition power factor correction circuit," IEEE 1994 APEC, pp. 591-597, and is herein incorporated by reference. This is a modification of the hard-switching boost converter of FIG. 1. Specifically, a capacitor C2 is arranged across the switch S1. To achieve ZVS of S1, the auxiliary switch S2 is turned-on before turning-on S1. Then the current in the inductor L2 increases until it reaches the level of the current in L1. Simultaneously, the capacitor C2 and the inductor L2 create a resonance thereby reducing the voltage across the switch S1 to zero before S1 is turned-on. The diode D1 is turned off without the problem of a high reverse recovery current passing through the switch S1. The capacitor C2 minimizes the voltage across the switch S1 to a very low value during turn-off. Diode D4 blocks any current through diode D1 from entering the switching path of switch S2.
Unfortunately, the ZVS boost converter turn-off losses of the switch S2 are significant because the inductor L2 and S2 are carrying the load current before S2 is turned-off. Therefore, (1) the energy stored in the parasitic capacitance of the switch S2 dissipates in S2 during turn-on, (2) the switch S2 experiences substantial turnoff losses because it carries the full inductor current, (3) the inductor L2 must be designed to limit any reverse recovery current spike from the diode D1 during turn-on of S2, and (4) the tailing effect of IGBTs (Insulated Gate Bipolar Transistors) during turn-off causes difficulties when using IGBTs in power converters in a 1-5 kW power range.
Another example of a ZVS quasi-resonant boost power converter is shown in FIG. 3. During the turn-off of the switch S1, the inductor L2 and capacitor C2 cause a resonance, thereby making the voltage across the switch S1 nearly zero. Moreover, the switch S1 is closed when its anti-parallel diode D2 is conducting. Thus, the current is zero during turn-on of the switch S1. However, the current through S1 is sinusoidal. Thus, the peak and RMS currents are increased. Consequently, the quasi-resonant power converter eliminates switching losses at the expense of conduction losses. Furthermore, a wide range of operating switching frequencies is required to maintain a constant output voltage.
Summary of Conventional Prior-Art Circuits
Although these known loss-less boost power converters have better characteristics than the hard-switching converters, certain disadvantages still remain. Specifically, the known ZVS boost power converter second switch is not loss-less, as explained earlier. On the other hand, although a resonant switching power converter may eliminate switching losses, it increases conduction losses. Moreover, the output voltage in the resonant switching converters is controlled by frequency modulation. Therefore, this circuit requires additional circuitry to carry out such frequency modulation.
Accordingly, an improved switching power converter is needed for 1-5 kW output power levels. The improved active network should be capable of operating at higher switching frequencies to increase power density (watts per cubic inch). The improved snubber network should eliminate reverse recovery current spikes in the switching power converter. It should also limit peak device voltage and current stresses, limit peak capacitor voltages, limit RMS currents, have low sensitivity to second order effects, have low EMI, and be capable of using widely available control integrated circuits. Lastly, the improved active snubber network should be adaptable for use in various switching power converter circuits such as boost, buck, forward and flyback power converters.
Soft-Switched Built-In Active Snubber Circuit
This application discloses a zero-voltage soft-switched power converter using an active snubber circuit. The innovative soft-switching power converter has relatively low conduction losses compared to resonant topologies. This is accomplished by modifying conventional switching power converters and providing an improved active snubber network. The low losses are due to the capability of switching a pair of active-element networks simultaneously. Moreover, only one inductor is required with the pair of active networks.
This active snubber circuit improves efficiency, power density, and transient performance, reduces switching losses and EMI, and also operates at a fixed switching frequency. The proposed network also reduces and/or eliminates the large currents and reverse recovery current spikes normally seen in conventional switching power converters. This circuit may be used in various switching power topologies such as boost, flyback and forward power converters.

Soft-switched built-in active snubber circuit


A data transmission system may have a sending apparatus that sends streaming data, and a receiving apparatus that receives the streaming data and transmits a request of switch of the streaming data to the sending apparatus, in which the sending apparatus may switch the streaming data in response to the received request. The receiving apparatus may include a receiving section, a storage section that stores the streaming data temporarily and transfers it, an operation-detecting section that detects whether a user operates the request, and a control section that controls a transfer rate of the streaming data stored in the storage section to fast-forward the streaming data when the operation-detecting section detects that the user's operation. The sending apparatus may include an information-adding section that adds to the streaming data additional information on the user's operation when receiving a notice of user's operation, and a sending section that sends the additional-information-added streaming data.

1. Field of the Invention
The invention relates to a data transmission system, a receiving apparatus, and a receiving method as well as a sending apparatus and a sending method. More specifically, it relates to a data-streaming system and the like.
2. Description of Related Art
Recently, many services in which image data, audio data or the like has been transmitted with a streaming scheme have been provided. A terminal that receives streaming data with the streaming scheme generally has a buffer which stores the streaming data temporarily, in order to improve instability in transmission and reception of data in a network and reproduce the streaming data smoothly.
FIG. 1 shows a configuration of a data-streaming system 1 as related art. In the data-streaming system 1 as related art, a server 11 that sends streaming data such as image data and audio data sends the streaming data to a client 13 through a network 12 in response to any requests by the client 13.
It is to be noted that the server 11 installs, for example, a television tuner therein and can receive any image and audio signals from an exterior device such as a digital versatile disk (DVD) player. Based on a control signal received from an outside, the server 11 also can switch between image and audio signals received from the television tuner and image and audio signals received from the DVD player or change the channel of the television tuner. Moreover, it is possible to control, through the server 11, operations of an exterior device such as a DVD player.
The client 13 includes a receiving section 21, buffers 22 and 24, a decoder 23, a reproduction section 26, and an output section 27, as shown in FIG. 2.
The receiving section 21 receives the streaming data from the server 11 through the network 12 and de-modulates the streaming data. The buffer 22 receives and stores the streaming data.
The buffer 22 also supplies the stored streaming data to the decoder 23 at a time when the decoder 23 performs decode processing. The decoder 23 receives the streaming data from the buffer 22 and decodes the image data and the audio data, separately, to supply the decoded image data and audio data to the buffer 24 where they are stored.
The buffer 24 supplies the stored streaming data to the reproduction section 26. The reproduction section 26 reproduces the streaming data received from the buffer 24 and supplies the reproduced stream data to the output section 27.
The output section 27 is constituted of a display for displaying an image, a speaker for sounding an audio and/or the like and outputs an image based on the streaming data and/or an audio corresponding to the image.
If a communication state is stable in the network 12, the client 13 can keep a sufficient communication rate to receive the streaming data so that the buffer 24 can store a sufficient amount of data like a hatched region of the streaming data in the buffer 24 as shown in FIG. 3. If a communication state then becomes instable in the network 12, the client 13 reduces the communication rate to receive the streaming data so that the buffer 24 stores a reduced amount of data like a hatched region of the streaming data in the buffer 24 as shown in FIG. 4.
Although the amount of data of the streaming data stored in the buffer 24 is reduced, the reproduction section 26 reproduces the streaming data stored in the buffer 24, which is received from a reproducing-speed-controlling section, not shown, so that reproducing operation does not stop even when the amount of data of the streaming data stored in the buffer 24 is reduced, thereby enabling the streaming data to be smoothly reproduced. Namely, the streaming data is once stored in the buffer 24 and the reproduction section 26 reproduces the streaming data after a fixed period of time has been elapsed.
It is to be noted that, in FIGS. 3 and 4, in order to simplify the description, only the buffer 24 and the reproduction section 26 are illustrated among the sections constituting the client 13 shown in FIG. 2, and the buffer 22 is omitted. Further, in FIGS. 3 and 4, triangle marks marked under the buffer 24 indicate an amount of data stored in the buffer. The indicated amount of data in the buffer is increased in accordance with positions from left end to right end in each of the figures.
As described above, however, the reproduction section 26 reproduces the streaming data stored in the buffer 24 after a fixed period of time has been elapsed so that if a user performs a fixed operation to instruct change of channels of the television tuner or the like, it is difficult to reproduce the streaming data after the user's operation, which corresponds to the operation, unless the streaming data before the operation, which is stored in the buffer 24, has been completely reproduced.
Thus, the user may view and hear the streaming data after his or her operation merely after he or she views and hears the streaming data before the operation, which is stored in the buffer 24, for a fixed period of time, namely, after the streaming data before the operation has been completely reproduced.
FIG. 5 illustrates items of streaming data stored in the buffer 24 on user's operation.
In FIG. 5, time is elapsed on a time direction from an upper side toward a lower side. States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a top in FIG. 5, are referred to as "State 1"; States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a second top in FIG. 5, are referred to as "State 2"; States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a middle in FIG. 5, are referred to as "State 3"; States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a second bottom in FIG. 5, are referred to as "State 4"; and States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a bottom in FIG. 5, are referred to as "State 5".
In other words, in FIG. 5, states in the server 11, the network 12, the buffer 24, and the reproduction section 26 are respectively transferred from the state 1 to the state 5 through the states 2, 3, 4 as time is elapsed.
It is to be noted that in FIG. 5, as in the cases of FIGS. 3 and 4, in order to simplify the illustration, only the buffer 24 and the reproduction section 26 are illustrated among the sections constituting the client 13 shown in FIG. 2. Further, in FIG. 5, squares in white indicate the streaming data before a user performs any operations while squares in black indicate the streaming data after a user has performed any operations.
At State 1 shown in FIG. 5, the server 11 switches the streaming data to be sent, from the streaming data before the operation to the streaming data after the operation, based on a notice of changing the channels received from the client 13 if a user performs a fixed operation such as channel changing. In the moment, the client 13 has yet received no streaming data after the operation from the server 11 so that the buffer 24 stores the streaming data before the operation and the reproduction section 26 reproduces the streaming data before the operation.
The buffer 24 is constituted of a first-in first-out (FIFO) memory. When the client 13 receives the streaming data after the operation from the server 11 through the network 12, the buffer 24 reads items of the data in a stored order thereof, as indicated at States 2 through 4. Accordingly, the buffer 24 reads items of the streaming data before the operation in order. In this moment, since items of the data read out of the buffer 24 are all the streaming data before the operation, the reproduction section 26 reproduces the streaming data before the operation.
The buffer 24 reads the streaming data after the operation when any streaming data after the operation becomes the oldest one among items of the streaming data stored in the buffer 24, and the reproduction section 26 then reproduces it as indicated at State 5.
Moreover, there is a method of reproducing the streaming data after the operation without any delay by deleting contents in the buffer 24 that stores the streaming data before the operation, namely, by flushing them, on a point of time when a user performs any operation.
FIG. 6 illustrates the flush operation in the buffer 24 on a point of time when a user performs any operation. It is to be noted that in FIG. 6, in order to simplify the illustration, only the buffer 24 and the reproduction section 26 are illustrated among the sections constituting the client 13.
In FIG. 6, as a case of FIG. 5, states in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a top in FIG. 6, are referred to as "State 1"; States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a middle in FIG. 6, are referred to as "State 2"; and States in the server 11, the network 12, the buffer 24, and the reproduction section 26, which are shown at a bottom in FIG. 5, are referred to as "State 3". In other words, in FIG. 6, states in the server 11, the network 12, the buffer 24, and the reproduction section 26 are respectively transferred from the state 1 to the state 3 through the state 2 as time is elapsed.
In FIG. 6, the server 11 switches the streaming data to be sent, from the streaming data before the operation to the streaming data after the operation, in response to the notice of changing the channels from the client 13, as shown in the State 1, if a user performs a fixed operation such as channel changing. In this moment, the buffer 24 of the client 13 is flushed and then the reproduction section 26 can reproduce the streaming data before the operation.
When the client 13 then receives the streaming data after the operation from the server 11 through the network 12, the buffer 24 has been flushed so that the buffer 24 can store the streaming data after the operation as the oldest stored streaming data as shown in State 2. The reproduction section 26 then reads the streaming data after the operation out of the flushed buffer 24 directly as shown in State 3 and reproduces it.
Thus, in the client 13 as related art in which the buffer 24 is flushed as shown in FIG. 6, the buffer 24 flushes the stored streaming data before the operation and then stores the streaming data after the operation so that the reproduction section 26 can reproduce the streaming data after the operation.
Japanese Patent Application Publication No. 2004-356695has disclosed a data distribution system in which if a user manipulates a remote controller, a threshold value of overflowing is changed to its threshold value for operation that is less than an ordinary threshold value; and if it is determined that an amount of streaming data in the buffer exceeds the threshold value for operation, a period of time up to displaying contents on an display device can be shortened by controlling any reproduction processing to be made rapid.

Data transmission system, receiving apparatus, and receiving method as well as sending apparatus and sending method


A method for starting an application program in a Linux container and a corresponding Linux system are provided, where the method includes: creating, by a container start process, a container according to a command entered by a user, creating a first application start process, and putting the first application start process into the container for execution; obtaining, by the first application start process, according to the command entered by the user, the number N of application programs to be started, and creating N−1 second application start processes, where N is a positive integer not less than 2; and starting, in the container, by the first application start process and the N−1 second application start processes, the N application programs to be started. By using technical solutions of the present invention, when the container is created, a plurality of application programs can be started simultaneously.

In a Linux system, a container can provide lightweight virtualization to isolate processes from resources. The container can effectively group resources managed by a single operating system into isolated groups, so as to better balance conflicting resource usage requirements among the isolated groups. Compared with other virtualization solutions, this solution requires neither instruction-level simulation nor just-in-time compilation. The container can locally execute an instruction in a core central processing unit (CPU) without any special interpretation mechanism, thereby avoiding complexity of paravirtualization and system call replacement.
A method for creating and entering a container is provided, and therefore an application program runs on a Linux operating system as an independent machine while sharing many underlying resources. The container provides isolation and also reduces overheads by sharing resources. Therefore, the overheads of the container are much less than that of real virtualization.
Referring to FIG. 1, a Linux container (LXC) starts an application program according to a command, such as lxc-start . . . [command], entered by a user, and the procedure is as follows:
A container start process creates a new container, and exists as a daemon of the container at the same time.
The container start process creates an application start process, and puts the application start process into the container for execution; and then the application start process initializes the container according to a command line parameter entered by a user.
The application start process starts, according to a command entered by the user by using a command line, an application program in the container, where a process of the application program is an initial (init) process in the container.
When another application program needs to be put into the container for execution, the application program needs to be started outside the container first, and a list of process identities (PIDs) of the application program is obtained; and then a PID of a current process is written into a control file to migrate a process execution environment to the container, so that the application program is executed in the container with a granularity of a process.
After a container destroying command is called, a container daemon exists as a container destroying process. The container daemon obtains a group identity (ID) of a process group in the container by using socket communication, and sends a SIGKILL signal to the process group in the container by using a kill( ) system call to terminate the process group in the container. After the container daemon detects termination of the init process in the container, the container daemon exits, and the container is destroyed.
In the foregoing existing method for starting an application program in a Linux container, only one application program can be started when a container is created, and if an additional application program needs to be started in the container, the application program needs to be started outside the container first, and then a process of the application program is put into the container for execution. Therefore, the operation is complex, and an execution environment of the application program is changed during operation. Furthermore, if the application program that needs to be started additionally is a multi-process application, PIDs of all processes of the application program need to be obtained, and a PID of the current application process is manually written into a control file for multiple times, which requires a system administrator using the container to be quite familiar with the application program so as to complete the foregoing operation that is complex and has a high probability of error. In addition, when some processes of the application program are inside the container while some processes are outside the container, a fault in the application program may be caused due to isolation of the container.

Method and system for starting application program in Linux container


A method and system for improved optimal mapping of LUT based FPGA's. The invention comprises performing a topological sort on the network to be mapped, whereby the network is represented in form of a Directed Acyclic Graph. The system locates feasible reconvergent paths existing from transitive fan-ins of each node using a Reconvergent Path Locator for replicating fan-outs of the nodes in the DAG, and therefore optimizing the number of LUT's and the time consumed in the mapping process.

1. Technical Field of the Invention
The present invention refers to an improved optimal mapping of LUT based FPGA. In particular the invention relates to a system that optimizes the design area in FPGA by exploring reconvergent paths in conjunction with Fan out replication in LUT mapping.
2. Description of Related Art
A programmable logic array device has a plurality of logic elements and an interconnect structure for conveying signals between logic elements. In LUT (Look Up Table) based FPGA's (Field Programmable Gate Arrays), mapping is done prior to the placement and routing of the design in FPGA. The objective of LUT mapping is to reduce the area/depth of the mapped solution.
In LUT based FPGA's, optimal mapping of gates into LUT's is done while ensuring that the number of transitive fan-ins to sink is always less than or equal to the number of LUT inputs. FIG. 1 illustrates the mapping process as a part of the FPGA development flow. 1.1 in the figure indicates the Gate Level Netlist as an input to the Optimizer Block that outputs Optimized Gate Level Netlist 1.2. The optimized netlist is then Mapped into LUT as shown in the 1.3 that is followed by Packing LUT's in to Programmable Logic Blocks (PLB's) 1.4. Then the design is simulated for Placement and Routing 1.5, 1.6. The bit stream is generated as in the Configuration Bits of the Design block 1.7. The bit stream is then downloaded in the FPGA to configure the FPGA as shown in the block 1.8. FIG. 2 illustrates a prior art Mapping process in LUT based FPGA's. 2.1 is Directed Acyclic Graph (DAG) that represents the mapping data as nodes, wherein the nodes in the DAG simulate the LUT's in the FPGA. 2.1 also illustrates initialization of the inputs to the LUT's (k) and the initialization of the fan-out factor. Block 2.2 illustrates performing a topological sort on the DAG. Block 2.3 illustrates the Computation of the Dependency variable for each node in the graph, whereby the dependency is computed keeping in view that the nodes are analyzed for their respective inputs and outputs. Block 2.4 performs check on the Dependency Variable till it is greater than the variable k. Block 2.5 shows the computation of the Priority Variable (Fc) for all the children of the node under consideration, and performing the same function for all other nodes in the Directed Acyclic Graph. Priority Variable (Fc) is a function of the following:                Contribution Variable (Zc), where c in the suffix denotes the children of the node.        Number of fan-outs (Oc) for the children of the node under consideration.        Fan-out Factor (FF) variable.
Block 2.6 sorts the list of the children of the node under consideration in the descending order of their priority values followed by block 2.7 that assigns LUT's to the children of the node under consideration until the dependency variable is less than k plus one.
Block 2.8 assigns a LUT to each output of a given node that have been left unassigned.
The computations for the Contribution Variable, Dependency variable, and the Priority Function is as shown below:                Let a given design be represented by a directed acyclic graph (DAG) G(V, E) where each vertex v in V represents a Boolean function and each directed edge (v, u) represents a connection between the output of v and the input of u.        Let VI denotes the set of nodes for which LUT is assigned.        That is, VI={vεV: a LUT is assigned to v}.        Contribution Zv:        For each PI v, Zv=1,        For each vεVI, Zv=1,        For all the other vertices vεV, Zv=Zu1+Zu2+ . . . +Z1         where u1, u2, . . . , u1 are all the children of v.        Dependency dv:        a) For each PI v, dv=1        b) For all other vertices vεV, dv=Zu1+Zu2+ . . +Z1 where u1, u2, . . . , u1 are all the children of v.        Priority Function Fv:Fv=F(Zv, Ov, FF)=Zv+FF*Ov        Where Ov is the number fan outs of v and FF is a suitable fan out factor.
The prior art Level Map method does not take into account of reconvergent paths and fan-out replication effectively, therefore it is essential to provide a system for optimizing design area in FPGA by exploring reconvergent paths in conjunction with fan-out replication in LUT mapping.


A safety apparatus for a bed comprised of two safety panels and a cover. Each safety panel comprises a horizontal stabilizer and vertically-extending panel of a synthetic polymeric material with a density of from about 1 to about 10 pounds per cubic foot. The width of the stabilizer is less than about 20 per cent of the width of the mattress. Disposing the horizontal stabilizer underneath a mattress secures said the vertically-extending panel in a substantially-vertical orientation along a side of said bed. Another embodiment comprises the foregoing side panel safety apparatus in combination with a safety rail of said bed, further comprising said safety rail; wherein said horizontal stabilizer blocks a person in said bed from moving a part of said person's body into contact with said safety rail such that said body part becomes entrapped from said contact. Another embodiment comprises movable vertical sections.

Patients in hospitals or long-term care facilities often reside in beds disposed between safety rails. Although the use of these safety rails provides some degree of protection against the risk of the patient falling off the bed, these safety rails present their own safety concerns. In some situations, patients prefer to lower the bed rails to increase comfort, disengaging the safety feature and its protective effects.
Patients, especially elderly or "developmentally disabled" patients, frequently self-inflict injuries by trapping their heads, buttocks, legs, feet, hands, arms, torso, or other body parts between the safety rails and the mattress. Degrees and severity of entrapment can vary from patient to patient depending on height, weight, cognitive function, level of ambulatory ability, and other factors. Injuries sustained also vary according to the type and length of entrapment. Bruising, sprains and breaks would result from minor events. More serious injuries, including death, can also occur in cases of prolonged events involving choking or suffocating entrapments. These safety concerns have given rise to a multiplicity of lawsuits against hospitals and long-term care facilities. For example, the Long Island, N.Y. Developmental Disabilities Service Office has been sued at least twice for injuries and or deaths resulting from a patient's entrapment with a safety rail assembly.
The management of one care facility located in Schenectady, N.Y. has discontinued the use of safety rail assemblies in some cases, and now has those patients sleeping on mattresses that have been placed upon the floor. As is apparent, this alternative arrangement is not optimal and presents its own set of problems.
U.S. Pat. No. 6,721,974 (Safety Equipment for Beds) elaborates on some of the problems and approaches to solving these problems: "Attempts to prevent such injury have included many variants of inflatable or padded supports capable of fitting to, or replacing, the sides of the bed or cot so as to better absorb the impact of the body against the hard structure. An example of this type of support is known from GB2326088A which discloses inflatable tubes, or compartments, which can be fitted to a bed to prevent a person from falling out of bed or from coming into contact with the solid structure of the bed. The tubes are releasably fined to the bed structure by means of ties."
"However, in solving one problem, this type of solution could introduce an additional difficulty: the bed occupant becoming stuck in the gap described by the interface of the inflatable side support and the mattress. An alternative approach disclosed in GB868320 goes some way to solving this problem of preventing the occupant from becoming stuck in the aforementioned gap, by attaching the mattress to the "safety fence" in such a manner as to eliminate the gap. However, the low sides of this safety fence are designed solely to prevent the occupant from falling out of the bed and not from sustaining injury as a result of contact with nearby solid structure during the course of a fit or other such uncontrolled body movement. Furthermore, U.S. Pat. No. 5,421,046 discloses "bumper pads" for fitting to a child's cot with traditional solid surrounds." The entire disclosure of each of these United States patents is incorporated by reference into this specification.
U.S. Pat. No. 4,672,698 (Bed Rail Cushion System) also elaborates on some approaches to solving these problems: "Removable padding arrangements for beds are known as illustrated, for example, by U.S. Pat. Nos. 421,656; 3,742,530; 4,215,446 and West German patent 614,367. These siderail padding arrangements are of two general types, the first being where the padding arrangement and the siderail for the bed are an integral arrangement and must be affixed to or removed from the bed together. A second type relates to padding arrangements to cover the existing siderails on hospital type beds with these being a relatively thin flexible padding arrangement which folds over and snaps to the bed siderail. The integral type padding arrangements are inconvenient and not adaptable to a wide variety of currently manufactured beds while the latter variety provide at best inadequate padding and typically allow the patient a gap or space between the bed mattress and the padded rail into which an arm, elbow or ankle may easily slip providing an opportunity for patient injury. It would be highly desirable to have a padding arrangement for a hospital type bed which was readily attached or removed and which completely filled any gap between the mattress and the pad while affording the patient maximum padding protection." The entire disclosure of each of these United States patents is incorporated by reference into this specification.
U.S. Pat. No. 4,672,698 (Bed Rail Cushion System) also elaborates on patents with devices and methods that attempt to solve these problems:" The U.S. Pat. No. 6,067,679 discloses a prop to hold a patient on his/her side while in a hospital bed in which a standard-sized hospital pillow is stowed in a rolled condition within a launderable sleeve. The sleeve has a flap that is tucked beneath the patient's side which allows limited patient rolling movement against the prop which contributes to patient comfort. The flap also keeps the prop close to the patient so that drastic movements which could cause injury do not occur. The U.S. Pat. No. 5,815,863 discloses a lateral slumber support wedge for supporting a user, such as a pregnant woman, in a lateral slumber support, while lying down on either the left side or the right side. The wedge provides compressible, but firm support for the spine and pelvic region of the user. The wedge has a triangular cross section, and an interior body made of foam, which can provide support, but which conforms to the spinal and pelvic regions of the user. The wedge also includes a fabric cover which is permanently sewn to a bed sheet dividing the sheet in half so it can be used by the user lying on either the left or right side. The U.S. Pat. No. 3,938,205 discloses a body positioner that is formed from a block of polyurethane foam having resilient characteristics capable of deformation and of permitting the passage of air. The positioner has an unsymmetrical pentagonal cross-section and a length substantially greater than its width so that the positioner can be rotated to provide for a variety of adjustable continuous positioning support surfaces." The entire disclosure of each of these United States patents is incorporated by reference into this specification.
U.S. Pat. No. 4,672,698 discloses a rigid bed rail cushion system that pads designed to provide a gap-free junction between the padded rails and the bed mattress. The entire disclosure of this United States patent is incorporated by reference into this specification. The disadvantages of these structures has been described above.
U.S. Pat. No. 6,721,974 discloses safety equipment for beds that comprise an inflatable wall structure secured to the sheeting to form a barrier against falling out of bed and a cushion against injury against the bed rails. The entire disclosure of this United States patent is incorporated by reference into this specification. While this device addresses some of the problems in the prior art, it has not proven completely satisfactory.
For example, the device described in U.S. Pat. No. 6,721,974 requires customized sheeting or certain ties and/or tabs to secure the device while in use. This may be inconvenient or cause additional cost to the user. In addition disclosed are four inflatable walls which are tied (or otherwise secured together) at their respective corners. Thus, in order to facilitate access to the bed or patient within the bed, or to facilitate patient entry or exit to and from the bed, it would be required that at least one side be untied or disengaged.
Additionally, the base of the device is substantially the same size as the mattress placed over or in it while in use. Thus, the manufacturer must make a multiplicity of sizes to accommodate various mattress sizes. Additionally, should a mattress be slightly deformed or manufactured imperfectly, a risk of a gap between the mattress and the wall of the device is created, defeating the very purpose of using the device to prevent gaps and decrease the possibility of entrapment.
Another disadvantage is that some polymeric materials used to manufacture inflatable devices support the growth of bacteria or produce latex-type allergic reactions in some patients.
The present invention, comprised substantially of foam, offers a latex-free, bacteria growth free alternative for the user. Comprised of foam material, it is not subject to failure such as puncture or deflation.
The present invention offers many conveniences to the user. First, it does not require special sheets, ties, or tabs. Standard sheets may be used with the present invention. Secondly, the use of side panels allows the user to incorporate a single panel, or a combination of panels, such that it is not necessary for all sides of the bed to be affixed with safety side panels if such was not desirable or convenient. Thirdly, since the stabilizer of the safety side panel slides under the mattress until it abuts tightly against it, a gap-free fitting to any size mattress may be accomplished without the necessity of multiple sizes or versions, an economic advanatage to manufacturers and distributers.
Fourthly, the cutout section in the safety side panel facilitates patient access without the necessity of the delay or extra steps of disengaging the device. Additionally, without the delay of the inflation steps, the present invention is also time saving to the user during the set-up process. Lastly, the present invention offers a fire retardant cover, meeting safety standards for instutional or infant use.
Similarly, the present invention offers advantages over the crib railing guard disclosed in U.S. Pat. No. 5,926,873 by incorporating a stabilizer whose width is substantially less than the width of the mattress and is not affixed to the crib railing. Thus, the safety side panel is self-supporting, not requiring the side rails for support or to be disengaged to facilitate access.
Thus, an economical and practical solution to these problems and hazards will provide benefits to both the patients and their caregivers.


A system and method for interjecting ambient background sounds into a set of headphones is provided. The system monitors an ambient sound environment and compares the ambient sound environment to a preset set of sound characteristics (e.g., frequency signatures, amplitudes and durations) in order to detect important or critical background sounds (e.g., alarm, horn, directed vocal communications, crying baby, doorbell, telephone, etc.). When a critical background sound is detected, the system interjects either a notification signal or a portion of the ambient background into the audio stream, thus alerting a user of a potentially important sound or event occurring within their immediate vicinity.

On a daily basis people are subjected to a variety of noises of varying amplitude, these sources of noise affecting a person's quality of life in a number of ways ranging from simple annoyance to noise induced fatigue and even hearing loss. Common sources of noise include those related to travel, e.g., subway trains, motorcycles, aircraft engine and wind noise, etc., and those related to one's occupation, e.g., factory equipment, chain saws, pneumatic drills, lawn mowers, hedgers, etc.
To help alleviate background noise while providing a source of entertainment, many people listen to music or other audio programming via a set of headphones. Unfortunately, the use of headphones may also lead to problematic, even dangerous situations if the user is unable to hear the various auditory cues and warnings commonly relied upon in day to day living (e.g., warning announcements, sirens, alarms, car horns, barking dogs, etc.). Accordingly, what is needed is a system that provides its users with the benefits associated with headphones without their inherent drawbacks and limitations. The present invention provides such a system.

Intelligent ambient sound monitoring system


An antenna includes a coupling device having first and second coupling plates, e.g. rectangular plates, connected at opposite ends of a conducting bar that acts as a stripline signal feed. A radio-frequency (RF) source may be connected to the conducting bar via a signal feed network. Multiple instances of the device may be arranged vertically in an antenna array assembly to operate together such that the radiation pattern of the antenna assembly is generally directed horizontally. The array may operate to provide a relatively flat azimuthal gain up to 180° across the UHF or VHF bands.

This section introduces aspects that may be helpful to facilitating a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art. Any techniques or schemes described herein as existing or possible are presented as background for the present invention, but no admission is made thereby that these techniques and schemes were heretofore commercialized, or known to others besides the inventors.
Conventional cavity-backed slot antennas are typically regarded as narrow bandwidth antennas in the UHF TV frequency band. Often, only 20 or fewer channels (≤120 MHz) can be covered at any one time. Even then, individual slot tuning is usually necessary to reach acceptable return loss and radiation pattern performance. Such performance constraints are undesirable and typically increase costs of transmission installation and/or repurposing for other frequencies/channels.
FIGS. 1A and 1B illustrate two types of conventional cavity-backed slot antennas. In a cavity-backed slot antenna, the slot is typically fed using only a single coupling element in the center of the slot, sometimes referred to as a probe antenna or an exciter. FIG. 1A illustrates an example of a cavity-backed slot antenna that uses a "T-bar" 110 to excite a cavity-backed slot 120. (For brevity, a cavity-backed slot may be referred to in various contexts herein simply as a "slot" with equivalent meaning.) FIG. 1B illustrates an example of a cavity-backed slot antenna for which a single center coupling element 130 feeds the cavity-backed slot 120. Both of these conventional designs typically exhibit drawbacks, e.g. a narrow operating bandwidth.
Some conventional antennas are advertised to be able to perform across the UHF television broadcast band, e.g. from 470 MHz to 700 MHz, but such capability is typically limited by the requirement to select in advance an operating channel to which the antenna is tuned and acceptable performance can be expected. Outside the selected operating channel, the antenna may exhibit an unacceptably high VSWR (voltage standing-wave ratio). Hence, if an antenna user were to select a different UHF channel, the antenna would either need to be re-tuned (if possible) or possibly even likely replaced. Furthermore, if the antenna were intended to serve several channels in the UHF-band, this is not easily achievable and will therefore likely result in very limited performance.