The method includes, receiving a content request message from a user terminal, comparing a batching window value and a timer value in session information when there is session information corresponding to received content, and transmitting a content response message including an address of a stored surrogate server to the user terminal when the timer value is less than the batching window value. In addition, the method includes, receiving a request message for requesting the same content from another user terminal, and transmitting the content response message including address information of the same surrogate server to another user terminal when the timer value is less than the batching window value. Therefore, since more channels can be assigned to one surrogate server, it is possible to decrease data transmission costs of the surrogate server.

1. Technical Field
The following description relates to content delivery technology, and more particularly, to a batching-based content routing method that can decrease content delivery costs and an apparatus for performing the batching-based content routing method.
2. Related Art
Recently, use of smart terminals has been increasing and demand for content provided through such smart terminals has been increasing. In providing such content, a content transmission rate is an important issue.
However, when a user device requests a content to a server that locates far from the user device, a content delivery time increases due to distance. Moreover, content delivery quality may be deteriorated according to, for example, server states (for example, overload) and network states (for example, traffic congestion).
Therefore, a content delivery network (CDN) is used to reduce a content delivery delay and a load of an origin server.
The CDN could be broadly divided into two types according to application scopes. A global CDN is appropriately among a number of internet service providers (ISPs), whereas a local CDN is appropriate for applying within a single ISP network.
The global CDN includes a origin server and surrogate servers. The local CDN includes a local server and surrogate servers. The origin server could correspond to the local server from their responsibility perspective and vice versa. The surrogate server may be located close to a user and hence immediately deliver content to the user. Despite such advantages, due to a limited disk capacity of the surrogate server, it is difficult to completely cache content (especially, videos) of the origin server.
In order to address such problems, the origin server (or the local server) stores all content whereas the surrogate server stores some part of the content (especially, a front part of the content, referred to as a prefix). The surrogate server delivers prefixes to clients who request the content via multicast, receives a suffix (a remaining content part other than the prefix) from the origin server (or the local server) via unicast, and then delivers the received suffix to the clients via multicast.
Here, the unicast is applied between two servers. That is, during a batching window period, the surrogate server batch-processes requests from a plurality of clients who want the same content, and requests suffix delivery from the origin server (or the local server) one time. In this way, since the surrogate server batch-processes content requests and delivers the suffix via multicast, it is possible to reduce delivery costs.
However, in this method, since client requests are batch-processed in units of single surrogate servers, reduction of content delivery costs would be a little bit limited. Especially, as the number of surrogate servers in the CDN increases, reduction of content delivery costs will not be changed significantly.

Batching-based content routing method and apparatus for performing batching-based content routing method

ELECTRONICS & TELECOMMUNICATIONS RESEARCH INSTITUTE


A device for expanding the number of stations controlled by an existing irrigation controller or the like, or which can be operated as a stand-alone irrigation controller. The device (10) includes a control processor (12) which sequentially activates one or more control lines (66) for a predetermined period of time, the time periods being independently set for each control line. The timing cycle of the device (10) can be initiated manually or from a station control line (60) of an existing master controller (50). Activation by a master controller occurs after the station control line to which the device is connected completes its timed cycle according to the master controller. One or more of the devices can be cascaded to provide unlimited expansion capability.

1. Field of the Invention
This invention pertains generally to irrigation controllers and more particularly to an apparatus for expanding the number of timed stations which can be controlled from a single master control unit.
2. Description of the Background Art
Conventional timer operated irrigation controllers are manufactured with a fixed number of stations, each of which sequentially operates an electric solenoid valve to permit the flow of water to an area to be irrigated. In the event that more stations are required, a conventional controller cannot be expanded and, therefore, must be replaced with a larger unit. And, where very large areas are to be irrigated, it is typically impractical to manufacture a controller with a sufficient number of stations to provide for complete coverage. Therefore, in those instances it is common to utilize multiple controllers or a master/slave system where the master controller operates one or more slave units, but does not directly operate any valves. One such example can be found in the U.S. Pat. No. 4,244,022 issued to Kendall on Jan. 6, 1981. While a system such as this can be expanded by adding more slave units, up to a fixed number, when that limit is reached, further expansion is not possible since the slave units themselves cannot be expanded.
Various devices heretofore developed have certain limited capabilities for expanding the number of stations which can be controlled from a single station control line. For example, U.S. Pat. No. 4,661,719 issued to Burchfiel et al. on Apr. 28, 1987 discloses an auxiliary switching circuit which can be used to restore control functions in the event of a broken control line. The device is coupled to the master controller side of the broken control line and, drawing its power from the control line, is activated by the master controller during the time period that the valve connected to the broken control line would have been operated. One or more valves can be operated by the device, which includes internal control and clocking circuitry. However, because the device is powered by the control line from the master controller, it can only operate for a total period of time which does not exceed the station operation time set in the master controller. In many instances, this is limited to one hour. Furthermore, because of this limitation, it is not possible to cascade additional units for unlimited expansion of the system. And, if the control line is again broken or the master controller loses power, the device will become non-operational.
Therefore, a need exists for a device which can provide for expansion of an existing irrigation controller and provide for virtually unlimited expansion of the existing system. There is further a need for a device which can provide for timed control of the irrigation system even when the master controller is non-operational. The present invention satisfies that need and overcomes the deficiencies found in the devices heretofore developed.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.


A computer system with a workflow server provides for automatic and prioritized assignment of work involving processing of medical information records, or "charts", to particular resources (personnel) in a hospital. In particular, as the system stores data regarding additional medical information records in a relational database, the workflow server identifies which such additional records constitute a new encounter for a particular patient. For each encounter, the system defines one or more visit cases, and may identify for each visit further subset cases for one or more of a number of application programs. Such application programs may include coding/abstracting of documents and assigning deficiencies in documents for completion. The system defines states corresponding to each application program. In response to requests from the application programs, the workflow server routes each defined case to a particular workqueue within the proper state, and then can assign each case to a particular resource (employee) within the proper workqueue. The criteria for the type and number of workqueues within each state, and the criteria for the assignment of resources within each workqueue, can be identified with whatever sophistication or prioritization that a hospital may desire.

Maintaining patient medical records, whether for an individual doctor or for the entire medical staff of a major hospital, presents many complications, which may be grouped broadly into three categories.
First, pertinent information for any one patient may come from an array of sources, including physical and medical history information provided by the patient, radiology reports, clinical and anatomical pathology reports, EKG readouts, physician orders, nursing notes, care plans, and insurance providers.
Second, upon discharge, a patient's medical record data is typically reviewed extensively. This includes reviews of the physician's attestation, of documentation of the treatment process, of all charts to ensure that they are complete, and of procedures and notes to be abstracted. If data is incomplete, payment organizations such as insurers may deny claims made by a health care provider.
Third, any number of parties require access to patient information, including hospitals, clinics, attorneys, regulatory agencies, courts, whoever pays the bills, and naturally the patients themselves. Keeping track of requests for access from these varied sources is quite burdensome.
Most medical record systems in use today are either paper-based or make use of computer systems only to a limited extent. Optical imaging systems have been used to scan printed documents into a computer system for storage, retrieval, viewing, and printing, but these systems do not provide the management functions needed to deal effectively with the myriad tasks described above. Health care providers are finding that existing systems and methods of managing medical records are not meeting demands placed upon them.
In particular, two administrative bottlenecks in the use of such systems are the coding/abstracting of medical records and the assigning of deficient medical records (e.g., missing data or signatures) to proper personnel for completion.
Existing systems typically store documents in a database on a file server to which a plurality of client workstations are attached. Standard database functions may be used in such systems to establish workflow assignments. But such a database-centered approach to workflow has disadvantages. Because databases are not specifically structured to accommodate the types of transactions required for workflow processing, using standard database functions to carry out such transactions would be inefficient, resulting in unacceptable system performance. This is especially so if sophisticated workflow processing functions are implemented, such as a prioritized assignment of work to particular personnel based on predetermined criteria to specify which employees will receive particular types of work.
A system that allows sophisticated workflow processing while maintaining acceptable system performance would be useful. In addition, in view of the present use of optical imaging technology for data input to the records system, it would be desirable to use such technology in a more automatic system.

Workflow server for medical records imaging and tracking system


A coextrusion die includes a plurality of annular cells stacked on top of each other. Each annular cell includes a plurality of openings aligned with openings in the adjacent cell, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be joined to form the annular cells through which plastic melt can be axially directed.

Annular dies are used to form laminated products from thermoplastic melts (hereinafter "melt"). Conventional annular dies consist of a monolithic structure containing a core mandrel that may contain a spiral groove and axially stacked annular cylinders that concentrically surround the mandrel. Gaps between the mandrel and the innermost cylinder as well as gaps between the innermost cylinder and the next cylinder radially adjacent to it form passages for melt flow. Thus, an increase in the number of melt passages in a conventional die requires an increase in the radial thickness of the die structure. Melt can be supplied to the die both axially and radially through multiple entry openings. Each melt stream then flows axially through the die along the passages, and eventually joins into layers where these passages join within the die, and then finally the melt exits the die at the die lip and is blown into film. The spiral groove that can be provided on the outer surface of the mandrel can assist in controlling both the direction and rate of melt flow.
Several problems have been encountered with the conventional annular die design including deterioration of plastic melt, difficulties in controlling and adjusting temperature of the melt, and inability to maintain uniform film thickness. For example, melt residues may remain in the passages formed by the gaps between the mandrel and the cylinders as well as those between cylinders. These residues may contaminate fresh melt flow and thus deteriorate the quality of films made from the die containing such residues. In addition, removing such residues is extremely labor intensive, particularly because of the small size of the passages and the difficulty of taking the die apart. Thus, melt that stagnates in the die passages shortens the useful life of the die. Furthermore, conventional extruder design dictates that each melt delivered to a die have a separate extruder, thus multiple extruders take up vast amounts of space and clutter work areas.
In addition, it is difficult to produce a laminate product containing film layers made of different materials because the varied temperature requirements of different materials are difficult to meet. Multiple streams of melts are used to produce a laminate product, and each stream may require a different temperature depending on the properties of the melt material in the stream. For example, one melt may have a higher melting point or different thermal properties than another melt flowing within the die. Since the annular cylinders are concentrically arranged in the conventional die, it is difficult to control the temperature of the different melts axially flowing along the cylinders, because temperature is controlled by applying heat in a radial direction from the outer periphery of the die. Since the number of concentric cylinders surrounding the core is increased to form multi-layered films, the peripheral heating system makes it difficult to apply the proper heat to plastic melt that is flowing along the inner cylinders of the die.
Furthermore, the axial height resulting from the monolithic die design may produce inconsistent film thickness. Producing a laminate with an increased number of laminate layers using a conventional die not only requires more concentric cylinders that increases radial thickness but also increased axial height to join the melt passages within the die. Inconsistencies in the thickness of extruded film may result because increased axial height makes the die susceptible to thermal expansion, leading to inclining of the die.
U.S. Pat. No. 5,076,776 issued to Yamada et al. discloses an annular coextrusion die for a lamination product. The die consists of stacked annular plate-like rings with one opening in the center of the ring. Each plate-like ring has a number of manifolds cut into it that spiral inward. In operation, melt flows through an entry flow area adjacent to the center opening in each plate-like ring. A gap exists between the manifolds, and the melt overflows this gap to the next manifold. The center opening of the plate-like rings form a gap with the core mandrel creating an axial melt passage. The melt is thereby directed from the melt opening on the radial periphery of the plate-like ring through the manifolds, across the entry flow area into the melt passage and out through the die lip.
The die disclosed in Yamada et al. still requires labor-intensive die manufacture to produce the spiral manifolds of various thickness. In addition, the manifolds that are cut into plate-like rings require that these rings have a tangible thickness, which contributes to the overall axial height of the die. Furthermore, the melt residue problem associated with the conventional annular die remains an issue with this die design.


The invention provides a multi-piece solid golf ball having a core, an outermost layer cover with a surface on which are formed a plurality of dimples, and one or more intermediate layer between the core and the cover. At least one intermediate layer and the outermost layer cover are each formed primarily of an ionomer-containing thermoplastic resin. The resin of which the outermost layer cover is formed contains up to 20 wt % of a ternary copolymer ionomer and has formulated therein from 0.1 to 5.0 parts by weight of short organic fibers per 100 parts by weight of the resin. The golf ball of the invention has a fully satisfactory flight performance and a good feel on impact. Moreover, it has an excellent durability to cracking on repeated impact and also an excellent scuff resistance.

The present invention relates to a multi-piece solid golf ball composed of a core over which have been formed two or more covers. More specifically, the invention relates to a multi-layer golf ball which enables the distance to be increased due to the ball rebound and a spin rate-lowering effect while retaining a good feel on impact, and which achieves an improved scuff resistance on approach shots.
There exists a desire recently for durability to repeated impact and for resistance to the formation of burrs (scuff resistance) on the surface of the ball arising from repeated impact with various types of clubs. Improvements in durability to cracking on impact and scuff resistance are of critical importance to the golfer as factors in the ability to use a ball for a long time.
At the same time, golf balls which travel farther when played and have a soft feel on impact are very appealing to the player. Ball developers have in the past proposed a variety of balls with this in mind. Numerous disclosures have been made in the art that provide an improved flight performance and an improved control on approach shots by giving the ball a solid, multi-piece construction having two or more cover layers and by optimizing the hardnesses of the respective layers and the core deflection.
Most such multi-piece solid golf balls include as a major component an ionomer resin-based outermost layer cover, but leave something to be desired in terms of their durability to repeated impact and their scuff resistance.
Various attempts have been made to further enhance the durability to cracking and the flight performance. Examples include the art disclosed in JP-A 2006-87925, JP-A 2006-87924, JP-A 2005-296655 and JP-A 2005-296654.
However, because the durability to cracking and flight performance of these prior-art golf balls is not yet sufficient, there remains room for further improvement.


A method is provided for securely delivering identity data units over a communications network to a client device. The method includes receiving a selection from a customer identifying a final zipped package to be unpacked. The final zipped package is unpacked to obtain a common package and a digital signature file signed by an entity generating identity data requested by the customer. The digital signature in the digital signature file is verified and the common package is unpacked to obtain a plurality of outer packages and an encrypted symmetric key. The symmetric key is decrypted with a private key associated with the customer and each of the outer packages is decrypted with the symmetric key to obtain a plurality of identity data units.

Digital information has become extremely important in all aspects of commerce, education, government, entertainment and management. In many of these applications, the ability to ensure the privacy, integrity and authenticity of the information is critical. As a result, several digital security mechanisms have been developed to improve security.
One commonly used approach to digital security involves a certificate authority (CA) to issue a certificate to a certificate holder. The holder can then provide the certificate to a third party as an attestation by the CA that the holder who is named in the certificate is in fact the person, entity, machine, email address user, etc., that is set forth in the certificate. And that a public key in the certificate is, in fact, the holder's public key. People, devices, processes or other entities dealing with the certificate holder can rely upon the certificate in accordance with the CA's certification practice statement.
A certificate is typically created by the CA digitally signing, with its own private key, identifying information submitted to the CA along with the public key of the holder who seeks the certificate. A certificate usually has a limited period of validity, and can be revoked earlier in the event of compromise of the corresponding private key of the certificate holder, or other revocable event.
One standardized approach to today's digital security is referred to as the Public Key Infrastructure (PKI). PKI provides for use of digital certificates to authenticate the identity of a certificate holder, or to authenticate other information. Typically, a PKI certificate includes a collection of information to which a digital signature is attached. A CA that a community of certificate users trusts attaches its digital signature and issues the certificates to various users and/or devices within a system.
In the current market, companies and individuals who simply need PKI identity data may rely on a third party PKI service provider to provide PKI identity data and related services. In most cases, the PKI service provider needs to transfer PKI identity data over the network to its customers. Since identity data is being transferred over the network, the PKI service provider must present its customers means to ensure non-repudiation and correctness of the identity data. Accordingly, it would be desirable to ensure the privacy, authenticity and integrity of the identity data not only in the final environment but also at every intermediate stage of the delivery process.

Layered protection and validation of identity data delivered online via multiple intermediate clients


A vehicular brake control apparatus detects risky occasions and locations that may be risky by using, for example, an infrastructure information input device or a navigation device, and, for such locations and the like, performs the pre-charge so that braking force will be promptly generated. Therefore, the pre-charge can be precisely performed under necessary circumstances, irrespectively of the driver's accelerator operation. Hence, when the driver depresses the brake pedal at such a location or the like, braking force will be promptly generated. Thus, accidents and the like can be prevented.

In a conventional brake control apparatus, an ineffective stroke in a brake caliper, for example, a gap between a brake pad and a disc rotor, can be eliminated beforehand by applying pressurizing force to the brake pad (e.g., Japanese Patent Application Laid Open No. HEI 10-157585).
In this brake control apparatus, a wheel cylinder (hereinafter, referred to as "W/C") provided separately for each tire wheel is pre-charged with a pressure (W/C pressure) in accordance with the releasing speed of the accelerator pedal so as to substantially eliminate the ineffective stroke in the brake caliper prior to engagement of the brake. Therefore, when a brake engaging mode is entered, braking force is promptly generated.
However, since the pre-charge of W/C pressure is performed in accordance with the releasing speed of the accelerator pedal, the aforementioned conventional brake control apparatus has the following drawbacks. That is, if a need for brake engagement suddenly arises, for example, in a case where the accelerator pedal is slowly being released or a case where the accelerator pedal has been in an undepressed state, the ineffective stroke in the brake caliper cannot be eliminated beforehand, and therefore the prompt generation of braking force cannot be achieved.
Furthermore, since the conventional brake control apparatus performs the pre-charge of W/C pressure on the basis of the releasing speed of the accelerator pedal alone, the pre-charge is executed irrespectively of surrounding environments, that is, may be executed even when the pre-charge is not needed. Therefore, uncomfortable brake feeling may be caused to a driver.

Vehicular brake control apparatus and vehicular brake control method


An apparatus for cutting a plug from the end of a cigar comprises a housing having a hollow body portion with opposite first and second ends. The first end of the hollow body portion has a cutting edge for cutting a portion of a cigar wrapper at the end of a cigar prior to smoking. A spring-biased plunger is movable within the hollow body portion first end along a longitudinal axis thereof toward and away from the cutting edge. An elongated piercing member is attached to, and movable with, the plunger. A handle is accessible from the exterior of the housing for moving the plunger within the hollow body portion first end. The cutting edge is adaptable to cut a portion of a cigar wrapper at the end of a cigar to create a plug of the cut portion of the cigar, which plug remains at least in part within the hollow body portion first end, and the handle is operable to move the plunger toward the cutting edge to eject the plug from the housing.

1. Field of the Invention
The present invention relates to an apparatus for piercing and cutting a plug from the end of a cigar.
2. Description of Related Art
Devices for piercing and cutting the ends of cigars have been known in the prior art. Such devices are used to pierce the cigar wrapper at the closed end of the cigar and remove a portion thereof to provide an opening for smoke to enter the mouth of the cigar smoker. Examples of cigar piercing and cutting are found in U.S. Pat. Nos. 5,525,763, 4,711,254, 2,832,354, 1,734,620, 703,162, 308,906 and 282,764. While these devices have been generally useful, they have not been able to simply and efficiently deal with the removal of the plug created by a tubular cutter. For example, the '763 patent requires one to eject the plug cut from the cigar using two hands, one grasping the end of the device and the other pushing the collar to eject the plug. Others, such as the '620 patent have a mechanism which is overly complex. Also, both of these devices cannot simultaneously pierce and cut a plug from the cigar end. There has been a long-felt need to provide a device which overcomes these problems.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a device for piercing and cutting a cigar which simply and efficiently deals with the problem of removal of the plug created by cutting the cigar end.
It is another object of the present invention to provide a device for piercing and cutting a cigar which may be used with one hand.
A further object of the invention is to provide a device for piercing and cutting a cigar which has a relatively simple structure for manufacturing and cost efficiencies.
It is yet another object of the present invention to provide a device for piercing and cutting a cigar which may both cut the plug and pierce the cigar at the same time.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.


To provide a video signal processing apparatus capable of generating video signals that enable displaying and recording of a high-quality picture. A video signal processing apparatus according to an embodiment of the present invention includes a decoder decoding an input TS to generate a video signal having a field frequency fv of 60 Hz or a video signal having a field frequency fv of 59.94 Hz, and a converter converting the respective video signals into NTSC video signals having a color subcarrier the phase of which is inverted for each frame.

1. Field of the Invention
The present invention relates to a video signal processing apparatus and method, in particular, a video signal processing apparatus and method for converting plural input video signals to other video signals to output the converted signals.
2. Description of Related Art
In the past 50 years, an analog television broadcasting service has been provided in the USA via land broadcasts, cable, or other such media based on an NTSC (National Television Standards Committee) system.
A video signal based on the NTSC system is described. FIG. 7 shows a waveform of the video signal based on the NTSC system. This video signal includes a video signal component where a luminance signal (Y signal) and a chrominance signal (C signal) are multiplexed, a burst signal used as a reference for the chrominance signal, and a horizontal synchronizing signal for horizontal scanning, and is called a composite signal.
Further, this video signal has a frequency characteristic as shown in FIG. 8. The video signal is within a frequency band from 0 to fmax (maximum frequency), and a luminance signal falls within such a frequency band. The chrominance signal is modulated with a color subcarrier SC of a color subcarrier frequency fsc, and its frequency is within a frequency band spread from the color subcarrier frequency fsc by a predetermined value. This color subcarrier frequency fsc is also a frequency of the burst signal of FIG. 7. Considering the NTSC video signal, for example, fmax≅4.2 M Hz, and color subcarrier frequency fsc=3.579545 MHz.
A television receiver conforming to the NTSC system receives such a video signal, separates the video signal into a luminance signal and a chrominance signal (Y/C separation), and demodulates the chrominance signal (chroma demodulation) to display moving pictures. In general, the Y/C separating ability of the television receiver has a limit, so the separated Y signal components and C signal components involve crosstalk. In particular, the Y signal represents the luminance level, while the C signal is a signal demodulated with the color subcarrier SC (burst signal), the C signal causing crosstalk with the Y signal appears to be consecutive dot-like interfering wave (dot interference) in the human eyes. To that end, in the NTSC system, the following devises are made for the purpose of reducing the interference due to the crosstalk.
FIGS. 9A and 9B show a relation between a scanning line and a color subcarrier in an NTSC video signal. In the NTSC system, interlacing scanning is adopted to scan a frame as a single image which is divided into two fields. For example, first scanning displays even-numbered lines, and second scanning displays odd-numbered lines. One frame has 525 scanning lines, so one field has 262.5 scanning lines.
FIG. 9A is a field perspective view and sectional view showing a phase shift of a color subcarrier in each field based on the NTSC system, and the fields are arranged in order of display time. In FIG. 9A, 5 fields (M+0-4), that is, 2.5 frames are arranged in turn. In FIG. 9A, to focus the description on the phase shift of the color subcarrier SC, only the color subcarrier SC repeatedly appears. In practice, however, the waveform of FIG. 7 repeatedly appears depending on a color or luminance. As shown in FIG. 7, in the NTSC system, the phase of the color subcarrier SC is inverted every scanning in each field, and also inverted every frame. The phase inversion of the color subcarrier SC is described using various frequencies. Frequencies that are specified on the basis of standard NTSC system are represented by the following expressions (1) to (4).Standard field frequency fv=60 Hz/1.001=59.94 Hz  (1)Standard frame frequency fv/2=30 Hz/1.001=29.97 Hz  (2)Standard line frequency fH=262.5 fv=15.734 kHz  (3)Standard color subcarrier frequency fsc=227.5 fH=3.579545 MHz  (4)
The above expression (4) represents that the color subcarrier SC in one line has the frequency of 227 cycles+0.5 cycles (half-wavelength). That is, the color subcarrier SC of a target line is 0.5-cycle shifted from the color subcarrier SC of a subsequent line at the same position. Hence, the carriers of adjacent lines are 180° out of phase with each other. Such inter-line phase inversion is called "line interleaving".
Further, the standard color subcarrier frequency fsc and the field frequency fv have a relation of the following expression (5).fsc=2×227.5×262.5 fv=119437.5 fv  (5)
The above expression (5) shows that a color subcarrier SC in one frame has a frequency of 119437 cycles+0.5 cycles (half-wavelength). That is, the color subcarrier SC shifts its phase by 0.5 cycles every frame, so the color subcarriers SC of adjacent frames are completely in opposite phase. Such inter-frame phase inversion is called "frame interleaving".
A field sectional view of FIG. 9A shows a phase shift of the color subcarrier SC at the far right of each field in the field perspective view of FIG. 9A. In FIG. 9A, encircled numbers indicate a phase shift from a phase of the color subcarrier SC in the field "M+0" on line "N+1" at the far left; this phase is used as a reference. Here, "0.00" denotes "in phase", i.e., no phase shift, and "0.50" denotes "in opposite phase", i.e., a phase shift of 0.5 cycles. As mentioned above, the color subcarrier SC inverts its phase between lines in a field and between frames.
FIG. 9B shows a screen display image as viewed from the observer's eye in the sectional view of FIG. 9A. If the color subcarriers SC of adjacent lines or frames are in phase without the line- or frame-interleaving, crosstalk components resulting from the Y/C separation look like a stripe pattern or fixed pattern on the screen, so an observer has a difficulty in viewing an image. However, as shown in FIG. 9B, owing to the phase shift of FIG. 9A, level differences (peaks and troughs) of the color subcarrier SC appear leveled. Hence, as shown in FIG. 9B, a screen display image in a given color is obtained.
Referring next to FIGS. 10A to 10C, the display image is described in more detail. FIG. 10A shows display images of the respective fields (M+0-3) of FIG. 9A. FIG. 10B shows display images of two frames each obtained by combining two of the fields of FIG. 10A. FIG. 10C shows a display image obtained by superimposing the two frames of FIG. 10B. For ease of explanation, the peaks and troughs of the color subcarrier SC are represented in black and in white, respectively.
As shown in FIG. 10A, the color subcarriers SC of adjacent lines in each field are in opposite phase due to line interleaving, so the white and black portions appear in different patterns between adjacent lines, and each white portion and each black portion of adjacent lines overlap together; neither the white portions nor the black portions overlap each other. That is, as shown in FIG. 10B, a checkered pattern is obtained.
As shown in FIG. 10B, in one frame obtained by superimposing two fields, a line of the next field is fitted in between the lines of the target field, and the white portions and the black portions alternately appear every two lines to form a checkered pattern. Further, owing to frame interleaving, each white portion and each black portion of adjacent frames overlap together; neither the white portions nor the black portions overlap each other.
By superimposing the two frames, as shown in FIG. 10C, the white portions and the black portions completely overlap to obtain a display screen in a given color with an averaged brightness. That is, if an observer checks on the television screen the color subcarrier SC that inverts its phase between frames, these color subcarrier SC components would be perceived as flicker components of 15 Hz. Owing to the human eyes' space charge effect, the light and dark portions appear to cancel out in the eyes of the observer and thus, the luminance difference is hardly perceived.
As mentioned above, the NTSC system adopts the color subcarrier frequency fsc such as is line- or frame-interleaved to minimize an influence of various interferences.
Meanwhile, in the USA, an ATSC (Advanced Television Systems Committee)-compliant digital television broadcasting service has started from November, 1998 as the next-generation television broadcasting system in parallel with the NTSC-compliant broadcasting service. This ATSC system features "high definition/wide screen", "high-quality sound", "low noise", "compatibility with various media", and other such characteristics of a digital broadcasting system. Table 1 shows a result of comparing the ATSC system and the NTSC system as below.
TABLE 1Field frequency of transmissionDefinition ofside materialFieldresolutionDetails of definition(i: interlacing p: progressive)frequencyBroadcasting(imageverticalhorizontalAspect59.94p/59.94i/29.97p/23.976p/forsystemquality)(line)(pixel)ratio60p60i30p24poperationATSCHDTV size1080 1920 16:9—◯◯◯Both of(digital)(high7201280 16:9◯—◯◯59.94 Hzdefinitionand 60 Hzimage quality)SDTV size48070416:9◯◯◯◯(standard 4:3◯◯◯◯image quality)640 4:3◯◯◯◯NTSCSDTV size480640 4:3—◯——Only(analog)(standardequivalentequivalent59.94 Hzimage quality)(analog)◯: existing system
As shown in Table 1, in the ATSC system, 18 display systems from an SDTV (Standard Definition TV: standard quality) to the new system, HDTV (High Definition TV: high quality) are set for the moving pictures in varying combinations of a resolution (1920×1080, 1280×720, 704×480, and 640×480), an aspect ratio (16:9, and 4:3), and a field frequency fv (24 Hz, 30 Hz, and 60Hz). In the NTSC system, only one image quality, standard image quality, is defined.
The HDTV size and the SDTV size of the ATSC system are used for different applications based on the policy of a broadcasting station, a recoding size (resolution) of picture contents, and a theme of a TV program. For example, the HDTV size is used for contents requiring a high image quality such as movies, while the SDTV size is used for conventional NTSC-based broadcasting or used for concurrently delivering plural contents on account of requiring only a small data amount. Further, the size of the conventional NTSC system and the HDTV size of the ATSC system are different image sizes and thus incompatible.
Here, the field frequency fv means the unit representing how many fields (picture materials) are transmitted (displayed) per second. In the ATSC system, as shown in Table 1, there are two types as the field frequency fv, that is, NTSC-compatible 59.94 Hz series (23.976 Hz, 19.97 Hz, and 59.94 Hz) and 60 Hz series (24 Hz, 30 Hz, and 60.00 Hz). Nowadays, the US television broadcasting services are based on the two types of field frequencies.
Now, a description is given of why the ATSC system defines two field frequencies fv of 59.94 Hz series and 60 Hz series. The 59.94 Hz series is defined in conformity with the conventional standard NTSC system, and this frequency is intended for compatibility with the NTSC system. With this series, existing NTSC-compliant contents/devices (accumulated asset) can be used as they are, and it is easy to exchange contents between the NTSC system and the ATSC system. During a period of transition of the broadcasting system from the NTSC system to the ATSC system, devices of the two systems would be used, so this is extremely efficient. The reason the field frequency fv is not set to just 60.00 Hz but to a little smaller value, 59.94 Hz is that at the start of NTSC color broadcasting, the frequency fv of the color subcarrier SC is delayed from the frequency of a sound signal at a ratio of 1000/1001 in order to prevent the interference between the sound signal and the color subcarrier SC.
The 60 Hz series is 1.001 times (1,000 ppm) higher than the field frequency fv of the standard NTSC system, and is suitable for global distribution of broadcasting materials albeit sacrificing the compatibility with the standard NTSC system. The PAL system as an analog system adopted in Europe uses the field frequency fv of 50 Hz. As compared with a complicated field frequency fv ratio between NTSC system and PAL system (=59.94 Hz:50 Hz=1200:1001), the field frequency fv ratio between the ATSC system using the frequency of 60 Hz and the PAL system is as simple as 60 Hz:50 Hz=6:5. This facilitates the Europe-North America rate conversion. Further, it is said that the ATSC system using the frequency of 60 Hz is based on the fact the MUSE-compliant HDTV that has been developed in Japan prior to the ATSC system uses the frequency fv of 60 Hz, and its contents and devices can be easily applied. The ARIB system conforming to Japanese digital broadcasting standards is intended for the compatibility with the standard NTSC system, and standardizes the frequencies at 59.94 Hz series.
In this way, the ATSC broadcasting contents is distributed by selecting the HDTV size or SDTV size in accordance with its application and also setting the field frequency fv to 59.94 Hz or 60 Hz. For example, in the case where the content is distributed from the broadcasting station with the HDTV size, i.e., high resolution, a video signal decoded on the receiver side is accordingly based on the HDTV size. As mentioned above, the picture of the HDTV size is incompatible with the SDTV size of the conventional NTSC system. That is, unless the size is converted, it is impossible to input this video signal into a conventional NTSC television to view the picture or input a recording device (VCR/DVD recorder/HD recorder) to record the picture. Several years have elapsed from the start of the ATSC broadcasting service, and prices of an HDTV-ready TV monitor or HDTV recording device are coming down. Nevertheless, such devices are expensive, so the replacement of the device places great economical burden on a user. Therefore, in present developmental stages, it is desirable to enable the distribution of the ATSC broadcasting service to the user with little economical burden in consideration of the user's economical burden.
To that end, a video signal processing apparatus (set-top box) for converting the ATSC video signal received from the broadcasting station into the NTSC video signal has been widely used. As such a conventional video signal processing apparatus, there is known an apparatus disclosed in Japanese Unexamined Patent Publication No. 2004-208100.
FIG. 11 shows the configuration of a conventional video signal processing apparatus 900. The conventional video signal processing apparatus 900 converts an ATSC video signal input through an antenna 961 or a cable 962 into an NTSC video signal, and supplies the converted signal to an NTSC-compliant television receiver 970 or an NTSC-compliant recorder 980.
The conventional video signal processing apparatus 900 includes, as shown in FIG. 11, an ATSC decoder 910 for decoding an input transport stream (TS) into the ATSC video signal, a picture size converter 920 for converting an HDTV size into an SDTV size, an fv converter 930 for converting the 60 Hz-series field frequency fv to the 59.94 Hz-series field frequency fv, an NTSC encoder 940 for encoding the video signal of SDTV size into the NTSC video signal, and an fsc oscillator 950.
For example, if the input ATSC video signal has the field frequency of 60 Hz series, the picture size converter 920 converts the HDTV-size picture into an SDTV-size one, and the fv converter 930 converts the field frequency into 59.94 Hz. After that, the NTSC encoder 940 converts the video signal into the NTSC video signal based on the color subcarrier frequency fsc from the fsc oscillator 950.
If the input ATSC video signal has the field frequency of 59.94 Hz series, the picture size converter 920 converts the HDTV-size picture into an SDTV-size one, and the NTSC encoder 940 converts the ATSC video signal into the NTSC video signal based on the color subcarrier frequency fsc from the fsc oscillator 950 not through the fv converter 930.
However, the above conventional video signal processing apparatus 900 involves various drawbacks resulting from the provision of the fv converter 930. For example, the fv converter 930 stores the received image (field) into the fv converting buffer memory 931 and then converts the image into a desired field frequency fv to output the converted image, so a large memory capacity is required, which is uneconomical.
Further, the conversion ratio for the field frequency fv is as complicated as 60 Hz:59.94 Hz=1001:1000. This conversion based on the field frequency fv ratio means that one picture is removed from 1001 moving pictures to obtain 1000 moving pictures (referred to as "skipping"). The "skipping" takes place every 16.68 second, which value is calculated by converting 1001 to seconds (1001/60=16.68). As a result of "skipping", the continuity of moving images is lost every 16.68 seconds, resulting in unnatural images with a deteriorated quality. The resulting image quality is not an intended quality, so there is a fear about the collision with the portrait rights.

Video signal processing apparatus and video signal processing method


A message is wirelessly broadcast to wireless terminals by error correction coding the message to produce an error correction coded message block, dividing the error correction coded message block into frames and error correction coding the frames to produce error correction coded frames. The error correction coding frames are wirelessly broadcast to the wireless terminals. At the wireless terminals, the frames are received and the frames are error correction decoded to produce error correction decoded frames. The error correction decoded frames are combined into a message block, and the message block is error correction decoded to produce the message. By error correction coding the entire message in addition to error correction coding the frames of the message, long messages may be reliably broadcast and received, notwithstanding fading and other problems in the transmission. Accordingly, a broadcast channel that is designed for short message usage also may be used to reliably transmit long messages. The invention may, for example, be applicable to a TDMA system that includes a Digital Control CHannel (DCCH) having a short message Service Broadcast Control CHannel (S-BCCH) logical channel. The error correction coded frames are placed in the S-BCCH logical channel. The S-BCCH logical channel is then wirelessly broadcast to the radiotelephones in a plurality of TDMA time slots.

This invention relates to methods and systems for radio communications, and more particularly to methods and systems for wirelessly broadcasting messages to wireless terminals such as radiotelephones.
Commercial radio communications are widely used for voice and/or data communications. Pagers and cellular phones, in particular, have become relatively common. These two different types of communication devices, and supporting systems, have evolved from different fundamental purposes. In particular, pagers traditionally provide one-way, limited information to one or more end users and cellular phones traditionally provide two-way voice communication service.
As time and technology progress, the traditional functional dividing lines between these two different types of radio communication devices have become blurred. Pagers have acquired some of the functionality that was traditionally provided by cellular phones and vice-versa. For example, two-way pagers have been developed which permit the pager user to transmit messages to the paging system, which messages can then be forwarded to other parties. Similarly, cellular phones have acquired the capability to transmit and receive short (e.g., on the order of 160 alphanumeric character) text messages which can be output on the display of a cellular phone.
This evolution in radio communication devices has led to the development and marketing of a host of new information services. For example, paging systems have been implemented which provide for the broadcast of information services, e.g., stock quote information services, to a large number of subscribers that have pagers with displays. These pagers periodically receive information over an air interface associated with a large number of stocks or other financial instruments such as options, futures. etc., and display the current prices of these instruments so that a user can track a portfolio""s performance.
Users of cellular phones may have interest in the provision of a similar service which would provide information service support in a cellular network. However, cellular systems, unlike paging systems, have conventionally been designed around the paradigms of (1) limited bandwidth due to a restriction on the spectrum allocated by various governing bodies such as the FCC for cellular applications and (2) the notion that most of the limited bandwidth should be reserved for point-to-point connections such as voice connection between the cellular phones and the system, with only a relatively small fraction being reserved for broadcast (point-to-multipoint) transmissions from the system to the cellular phones operating in the system. Due to this latter feature of cellular systems in particular, system designers generally are very careful regarding the amount of information transmitted on the available broadcast channels and the frequency with which this information is repeated. Thus, the provision of broadcast information services to cellular radio communication systems may not readily be accomplished by the most straightforward approach of broadcasting whatever information is desired for all subscribers to display on their cellular phones.
For example, in a Time Division Multiple Access (TDMA) cellular radiotelephone system, each radio frequency is divided into a series of time slots, each of which contains a burst of information from a data source, e.g., a digitally encoded portion of a voice conversation. By time multiplexing bursts associated with different sources, more than one channel can be supported on each radio frequency. The time slots are grouped into successive TDMA frames having a predetermined duration. The number of time slots in each TDMA frame is related to the number of different users that can simultaneously share the radio channel. If each slot in a T DMA frame is assigned to a different user, the duration of a TDMA frame is the minimum amount of time between successive time slots assigned to the same user.
The successive time slots assigned to the same user, which are usually not consecutive time slots on the radio carrier, constitute the user""s Digital Traffic Channel (DTC). As mentioned above, this is typically a point-to-point resource. In fact, TDMA systems generally reserve the majority of the available radio channels for use as DTCs to ensure a large traffic capacity. However, as described in more detail below, Digital Control CHannels (DCCHs) are also provided for communicating control signals and overhead information, including a mechanism for connecting to the radio communication system and being assigned a DTC.
Similar types of resource allocations are found in other types of cellular systems. For example, in Code Division Multiple Access (CDMA) systems, channelization is performed by spreading data associated with a particular connection using a unique spreading code. This code, as opposed to or in conjunction with frequency and time differentiators, provides the receiver with a mechanism for extracting its intended data, by correlating the received composite signal with the code assigned to its traffic channel. Like TDMA systems, CDMA systems can also provide for broadcast control channels or other overhead signaling channels by allocating known codes thereto. However, like TDMA systems, CDMA systems also tend to reserve more resources, such as codes and power, for dedicated traffic channels than for broadcast information channels. Accordingly, it would be desirable to provide methods and systems which are able to provide broadcast information services within the constraints of existing cellular radio communication systems. In particular, it would be desirable to design broadcast information methods and systems that can accommodate an end user""s desire for a relatively large quantity of data that may need to be updated relatively frequently, while reducing and preferably minimizing the usage of scarce broadcast channel resources.
GSM systems presently can offer broadcast services. ANSI 136 has defined a broadcast channel that provides enhanced flexibility with respect to bandwidth allocation, sub-channelization, content description and change notification. However, broadcast services may not be extensively used in the future for the ANSI 136 or ANSI 95 technologies.
Packet data communication, a point-to-point form of communication, may provide access to the same services. Packet data communication, using for example GPRS as will be the supported in both GSM and ANSI 136, are being elaborated in the standards setting groups and resources are being assigned to the development of such products by vendors. Thus, the user may use a packet data service to access an Internet-based stock quote service in which the user""s portfolio is downloaded to a wireless terminal upon request by the user. Using a broadcast service, all the securities, possibly limited to a subset of all available securities in interest of bandwidth limitation, are sent on a broadcast channel. The wireless terminal continually or as a result of a user request reads the entire set of securities on the broadcast channel and further manipulation of the data. For example, extraction of the data for presentation as defined by the specific user""s portfolio may take place in the mobile station or in a companion lap-top computer.
Wireless packet data systems are now being developed and being made available. This is amplified by the ITU initiated development of xe2x80x9c3:e generationxe2x80x9d wireless systems. A focus of this activity is to provide a packet data services as efficiently as possible with bit-rates of 144 kbit/s, 384 kbit/s and 2 Mbit/s depending on the environment. To provide wireless packet data, the operators may only need to obtain the necessary equipment and then the user can access the Internet or a corporate mail system. However, the operator may then only provide a wireless bit-pipe but no content. The content provider may be the same companies that provides content in the wireline environment. A current trend in the Internet is for these companies to try to establish themselves as Internet xe2x80x9cportalsxe2x80x9d for as many users as possible. The portals, or entry points to the world wide web, generate revenue by providing advertisements on their sites.
It may be difficult for wireless operators to extend beyond providing connectivity to the existing and ever increasing Internet-based content provider. There are several reasons for the possible inability of the wireless operators to provide connectivity but not provide very much content. The development of broadcast services may require the operators to assign resources for the definition and specification of the services. For the example of the stock quote service, an additional step of translating the format and content from the data source into the format of the broadcast channel may be necessary. Charging mechanisms and associated content access control may need to be developed in order to generate revenue for the operators. A method for access control of broadcast services is disclosed in application Ser. No. 09/132,232, to the present inventor, filed Aug. 11, 1998, and assigned to the assignee of the present application, the disclosure of which is hereby incorporated herein by reference in its entirety.
However, providing a broadcast channel with stock quotes, sport results, weather reports etc. could provide an increased revenue stream for the wireless operator. Furthermore, a broadcast channel need not use up-link communication. The required bandwidth can be independent of the number of users and user request of the information whereas for the packet data scenario the bandwidth used generally is proportional to these two variables. Thus, for services that are widely subscribed to, a broadcast service may be more spectrum efficient then having all users make individual accesses to get information such as their stock portfolios.
If there are very few users subscribing to a service a packet data solution may be more efficient. Applications can be built which use a combination of broadcast and point-to-point service that can allow better control of bandwidth usage than only using one of the type of channels. For example, application Ser. No. 09/114,350, to the present inventor, filed Jul. 13, 1998, and assigned to the assignee of the present application, discloses a xe2x80x9cheadline newsxe2x80x9d service which is broadcast and the content is hyperlinked to more detailed information located in a service server. When the user selects an item or topic, the mobile station generates a point-to-point communication to the service server which may be a world wide web site or the detailed content may be downloaded to the mobile station. Thus, broadcast services may allow the operators to receive revenue for value added services and may be more efficiently, provided than packet data services.
It is therefore an object of the present invention to provide improved methods and systems for wirelessly broadcasting messages to wireless terminals.
It is another object of the present invention to provide systems and methods for wirelessly broadcasting messages to a plurality of radiotelephones in a cellular system.
It is still another object of the present invention to provide systems and methods that can allow relatively long messages to be broadcast over wireless communication systems having relatively short message service capability.
These and other objects are provided, according to the present invention, by systems and methods that wirelessly broadcast a message to a plurality of wireless terminals by error correction coding the message to produce an error correction coded message block, dividing the error correction coded message block into a plurality of frames and error correction coding the frames to produce a plurality of error correction coded frames. The plurality of error correction coding frames are wirelessly broadcast to the plurality of wireless terminals. At the wireless terminals, the plurality of frames are received and the frames are error correction decoded to produce a plurality of error correction decoded frames. The plurality of error correction decoded frames are combined into a message block, and the message block is error correction decoded to produce the message.
It has been found, according to the present invention, that by error correction coding the entire message in addition to error correction coding the frames of the message, long messages may be reliably broadcast and received, notwithstanding fading and other problems in the transmission. Accordingly, a broadcast channel that is designed for short message usage also may be used to reliably transmit long messages.
In a preferred embodiment of the present invention, the frames are also error detection coded in addition to error correction coded. Preferably, the message is error correction coded using block coding, and the frames are convolutionally coded.
In order to provide systems and methods that are compatible with existing short message service systems and methods, an indication is provided that the error correction coded message block is error corrected. The indication may be provided within the error correction coded message block, or outside the error correction coded message block. Preferably, an indication of at least one of the type of error correction coding and the amount of error correction coding in the error coded message block is provided. Moreover, the message is preferably wirelessly broadcast for multiple cycles, and an indication is also preferably provided of the number of cycles of retransmission and an identification of the current cycle number.
The invention may, for example, be applicable to a TDMA system that includes a Digital Control CHannel (DCCH) having a short message Service Broadcast Control CHannel (S-BCCH) logical channel. The message is error correction coded to produce an error correction coded message block and the error correction coded message block is divided into a plurality of frames. The frames are error correction coded to produce a plurality of error correction coded frames. The plurality of error correction coded frames are then placed in the S-BCCH logical channel. The S-BCCH logical channel is then wirelessly broadcast to the plurality of radiotelephones in a plurality of TDMA time slots.
At the TDMA wireless terminals, the plurality of TDMA frames including the DCCH are wirelessly received. At least a portion of the S-BCCH in the DCCH is error correction decoded to produce a plurality of error correction decoded frames. The plurality of error correction decoded frames are combined into a message block, and the message block is error correction decoded to produce the message.
As described above, an indication is preferably provided that the message is error correction coded. The indication may be provided within the S-BCCH or outside the S-BCCH. Preferably, the DCCH includes a Message Type (MT) field and the indication is provided implicitly in the MT field. Alternatively, the indication may be provided explicitly in another field. In another alternative, the message includes a Fast-BCCH (F-BCCH) and an Extended-BCCH (E-BCCH). The indication is provided in the F-BCCH or the E-BCCH, that at least one message in the S-BCCH is error correction coded.
In a TDMA system, the error correction coding of the message is preferably performed by block coding, and the error correction coding of the frames is preferably provided by convolutional coding. The frames may be convolutionally coded at less than rate {fraction (1/2)} convolutional coding, due to the added coding that is provided in the message block. At the TDMA wireless terminal, error correction decoding at least a portion of the S-BCCH in the DCCH is performed in response to receiving an indication that at least a portion of the S-BCCH is error correction coded. As described above, the indication may be provided within or outside the S-BCCH. Accordingly, robust broadcast of relatively long messages may be provided in wireless communications systems having relatively short message service capability.

Methods and systems for coding of broadcast messages


A method and apparatus for determining and removing the error in the SPS measurement of the Global Positioning System due to ionospheric delay. The disclosed technique utilizes semi-codeless technique to provide high accuracy GPS measurements. The delay of the P code is varied and the signals are cross correlated until a maximum value is reached. When the cross correlation of the L1 and L2 signals is at a peak value, the relative delay between the L1 and L2 signals is proportional to the ionospheric delay. The derived ionospheric delay may be accounted for in measurement analysis of the L1 signal to provide for a high precision position solution. The semi-codeless correlator also provides the L1-L2 carrier phase measurement for wide-lane applications.

The Global Positioning System is a space-based radio navigation system operated by the US Air Force for the United States Government. GPS was originally developed as a military force enhancement system and continues to play this role. However, GPS has also demonstrated a significant potential to benefit the civilian community in an increasingly large variety of applications. In an effort to make the service available to the greatest number of users without adversely effecting national security interests two GPS services are provided. The Precise Positioning Service (PPS) is available primarily to the military of the United States and its allies for users properly equipped with PPS receivers. The Standard Positioning Service (SPS) is designed to provide a less accurate positioning capability than PPS for civil and all other users throughout the world.
In high precision GPS applications, it is desirable to be able to account for delay of the GPS signals caused by the ionosphere. For example, in an avionics environment utilizing GPS signals to determine the relative positions and velocities of aircraft, reduction of the error in the GPS signal increases the accuracy of the aircraft tracking data, thereby providing increased safety and reduced likelihood of collision. Thus, elimination of error in the GPS signal caused by the ionosphere to improve the accuracy of the GPS signal is highly desirable.
For each satellite in the global positioning system (GPS), the total signal comprises two transmission signals, the L1 signal having a carrier frequency of 1.57542 GHz, and the L2 signal having a carrier frequency of 1.2276 GHz. Both the L1 and the L2 signals are biphase modulated by several digital signals. The high precision code (P) is one modulating signal which has a code rate of 10.23 MHz. Another signal is an optional encoding encrypting code (E) which is utilized by the Department of Defense (DOD) to encrypt and deny unauthorized access to the L2 GPS signal. The E code has been reported to have a bandwidth of approximately 500 kHz in the open literature.
The United States Government defines the GPS Standard Positioning Service (SPS) as a position and timing service provided on the GPS L1 frequency. The GPS L1 frequency, transmitted by all GPS satellites, contains a coarse acquisition (C/A) code and a navigation data message. The GPS L1 frequency also contains a precision (P) code that is reserved for military use and is not part of the SPS. The P code can be altered without notice and will not normally be available to users who do not have valid crypto keys. GPS satellites also transmit a second ranging signal known as L2. This signal is not part of the SPS, although many civil receivers have incorporated technologies into their design that enables them to use L2 to support two-frequency corrections. SPS performance standards are not predicated upon use of L2.
The GPS Block II/IIA satellite constellation nominally comprises 24 operational satellites. Each satellite generates a navigation message based upon data periodically uploaded from a control segment which it then adds to a 1.023 MHz Pseudo Random Noise (PRN) Coarse/Acquisition (C/A) code sequence. The satellite modulates the resulting code sequence onto a 1575.42 MHz L-band carrier to create a spread spectrum ranging signal which it then broadcasts to the user community. This broadcast is referred to as the SPS ranging signal. Each C/A code is unique and provides the mechanism to identify each satellite in the constellation. The GPS satellite also transmits a second ranging signal known as L2 that supports PPS user two-frequency corrections. L2, like L1, is a spread spectrum signal and is transmitted at 1227.6 MHz.
The SPS signal, or SPS ranging signal, is an electromagnetic signal originating from an operational satellite. The SPS ranging signal consists of a Pseudo Random Noise (PRN) Coarse/Acquisition (C/A) code, a timing reference and sufficient data to support the position solution generation process.
The SPS ranging signal measurement is the difference between the ranging signal time of reception (as defined by the receiver's clock) and the time of transmission contained within the satellite's navigation data (as defined by the satellite's clock) multiplied by the speed of light. The SPS ranging signal measurement is also known as the pseudo range. The estimated geometric range is the difference between the estimated locations of a GPS satellite and an SPS receiver.
Navigation data is data provided to the SPS receiver via each satellite's ranging signal, containing the ranging signal time of transmission, the transmitting satellite's orbital elements, an almanac containing the abbreviated orbital element information to support satellite selection, ranging measurement correction information, and status flags. The position solution is the use of ranging signal measurements and navigation data from at least four satellites to solve for three position coordinates and a time offset.
Dilution of Precision (DOP) describes the magnifying effects on GPS position error induced by mapping GPS ranging errors into positions through the Position Solution. The DOP may be represented in any user local coordinate desired. Examples are HDOP for local horizontal, VDOP for local vertical, PDOP for all three coordinates, and TDOP for time. The Position Solution is the use of ranging signal measurements and navigation data from at least four satellites to solve for three position coordinates and a time offset.
The GPS signal consists of two synchronous transmissions on carrier frequencies of 1.57542 GHz and 1.2276 GHz, known as Link 1 (L1) and Link 2 (L2), respectively. Both the L1 and the L2 signals are biphase modulated by digital symbols with amplitudes of .+-.1. The digital signal sequences consist of a 10.23 Mbps high precision ranging code (P code - unclassified), a 1.023 Mbps clear/acquisition ranging code (C/A code), a 50 bps navigation information signal, and a classified encryption code (E code) overlaid on the P code. The E code forms a signal known as the Y code (Y=P.sym.E). The Y code provides GPS with anti-spoofing (A/S) capability and can be enabled or disabled by the GPS master control. Only authorized receivers have access to the Y code. Current operational policy by the DOD is to keep the Y code active at all times.
The L1 signal contains in-phase and quadrature components. The in-phase modulation is E.sym.P.sym.D and the quadrature modulation is generated by C/A.sym.D. The signal broadcast from the satellite is represented as: ##EQU1## where i denotes the i.sup.th satellite in the GPS constellation and P is the signal power.
The L1 1.023 Mbps C/A code repeats every 1 ms and provides a single frequency, low accuracy navigation signal for the Standard Position Service (SPS). Commercial users have access to the C/A and P codes. The C/A code is used by receivers to derive a hand-over word acquisition of the P code. Each P code has a repetition period of one week.
The L2 signal is modulated by either the P (or Y) code or C/A as directed by the GPS master control segment. Normal operation is selected to be P code modulation with the A/S feature enabled on L1 and L2 (Y code). The low rate navigation data may or may not be transmitted on L2 as selected by ground command. If the data message is transmitted and A/S is enabled, the L2 signal transmitted by the i.sup.th satellite is represented as: ##EQU2##
The low data rate navigation signal consists of orbital parameters and clock correction information plus other information. The DOD has implemented a feature known as selective availability (S/A) that degrades the accuracy of the navigation solution for unauthorized receivers. Authorized receivers can completely remove the effects of S/A.
The unauthorized user will not have access to the encrypted P code and cannot access the algorithm to remove the S/A degradation. The effects of S/A can be mitigated by differential GPS (DGPS) measurements and broadcast of the pseudo-range differential corrections provided the update rate is sufficiently high.
A class of algorithms known as codeless techniques can be used to measure the ionospheric delay. These algorithms are known as codeless because they do not require the knowledge or generation of the encrypted ranging codes. The codeless measurement is made by performing a cross correlation of the L1 and L2 signals. A correlation peak is detected when the ionospheric delay is equal to the delay of the L1 signal path. This technique works only because the modulation and encryption codes on both frequencies are identical and synchronous.
However, the primary disadvantage of this technique is the large SNR penalty incurred when the cross correlation must be done in the full bandwidth of the P code. The GPS signals are received well below the thermal noise. Correlating the L1 and L2 signals in the full P code bandwidth requires integration times on the order of several minutes to achieve acceptable pre-detection signal to noise ratios under weak signal conditions.
Additional disadvantage may be encountered in the use of codeless algorithms. Although ionospheric dynamics typically have time constants on the order of tens of minutes, measurements of the ionospheric delays of satellites with low elevation angles may be difficult or impossible to achieve with a high degree of accuracy. This is due to two reasons. First, the satellite signal power is very low when viewed at the horizon. Second, the signals typically experience higher dynamics at low elevation angles due to satellite and receiver geometry changes and longer ionospheric propagation path lengths. The longer integration times required under these conditions may distort dynamic information in the signal that users require for accurate and continuous correction for ionospheric delays.
It is known that the L1 and L2 signals are synchronous with respect to each other, including corresponding E codes. Since the signals are synchronous, the signals may be cross correlated with one another by utilization of a semi-codeless technique, controlling the relative delay of the signals with respect to each other and measuring the resulting correlation value. This cross correlation is performed in the reduced bandwidth of the E code. The relative delay is proportional to the ionospheric delay when the cross correlation has reached a maximum value.

Method and apparatus for eliminating ionospheric delay error in global positioning system signals


A windshield wiper blade connector may be used in connecting a windshield wiper blade to pin-type and hookslot wiper arms. The connector includes a side wall that defines a hole sized to receive a pin of a pin-type wiper arm. A movable beam is positioned relative to the hole in the side wall so that the beam engages the pin of the pin-type wiper arm when the pin is received in the hole to secure the connector to the pin-type wiper arm. A tab extends from the movable beam and is positioned so that the tab engages a slot of a hookslot wiper arm when the hookslot wiper arm is attached to the connector to secure the connector to the hookslot wiper arm.

The invention relates to a windshield wiper blade connector.
In general, the primary types of wiper arms for automotive windshield wipers are pin-type arms and hookslot arms. A wiper blade assembly may be connected to a pin-type arm by inserting a pin of the pin-type arm through a hole in a connector of the wiper blade assembly. A wiper blade assembly may be connected to a hookslot arm by sliding a hook of the hookslot arm over a connector of the wiper blade assembly until a tab of the connector locks within a slot of the hookslot arm. Manufacturers of windshield wiper blades typically produce a standard blade assembly and provide an assortment of connectors for use in adapting the standard blade assembly to different wiper arm configurations.


A system and method for automatic coding of medical claims, so as to minimize or eliminate possible human error and oversight that is common with prior art solutions.

Medical services are often rendered by personnel that are dispatched to a location of patient, rather than initially at a hospital, in an emergency response system. Such services are typically rendered by Emergency Medical Technicians (EMTs), who are the backbone of the emergency response system. Their skills and abilities are essential to a positive medical outcome. Fire department career personnel and nearly all volunteer fire personnel are trained to at least the EMT level.
Every EMT is trained to provide basic life support (BLS). The BLS system is comprised of EMTs who have completed more than 300 hours of both classroom and practical education in trauma care, cardiac and stroke care, CPR, advanced first aid, child birth and basic medication administration. In certain cases, an advanced level of emergency care is required. ALS is an acronym for advanced life support. The ALS system is comprised of paramedics who have received more than 3,000 hours of training in aggressive cardiac life support, pediatric life support, severe trauma and more than 200 other life-threatening emergency medical conditions.
Medical services that are rendered to a patient outside of a hospital, such as ALS or BLS, are typically covered at least in part by an insurance plan. An insurer, whether it is a government entity or private entity, will pay at least some of the costs of these medical services. Some challenges with payments by an insurer include the documentation required and the proper designation or classification of medical services. Insurers require precise documentation of the rendering of medical services in order to adequately cover their agreed-upon costs per the insurance plan. In an environment other than a hospital, such document is very difficult to obtain, let alone be precise.
While computer-implemented documentation systems have been introduced to automate the enormous task of processing medical claims, such systems still rely on human input, and are still subject to human error and oversight.

Medical claims auto coding system and method


The disclosure relates to an optical method for temperature sensing utilizing a temperature sensing material. In an embodiment the gas stream, liquid, or solid has a temperature greater than about 500° C. The temperature sensing material is comprised of metallic nanoparticles dispersed in a dielectric matrix. The metallic nanoparticles have an electronic conductivity greater than approximately 10−1 S/cm at the temperature of the temperature sensing material. The dielectric matrix has an electronic conductivity at least two orders of magnitude less than the dispersed metallic nanoparticles at the temperature of the temperature sensing material. In some embodiments, the chemical composition of a gas stream or liquid is simultaneously monitored by optical signal shifts through multiple or broadband wavelength interrogation approaches. In some embodiments, the dielectric matrix provides additional functionality due to a temperature dependent band-edge, an optimized chemical sensing response, or an optimized refractive index of the temperature sensing material for integration with optical waveguides.

The enhancement of EM fields in the vicinity of metallic nanoparticles and metallic nanostructures can be explained by the phenomenon of localized surface plasmon resonance. The shape and magnitude of associated features measured in the transmission or reflection spectra from these metallic structures depend on the enhanced scattering and absorption of light at specific wavelengths. The details of the extinction cross-section enhancement over a finite wavelength range is affected by several different factors that include the characteristic optical constants and geometry of the nanostructures illuminated by incident light as well as the optical constant of the surrounding matrix phase.
The origin of plasmon resonances are collective oscillations of the conduction band electrons, and they result from the presence of interfaces for nanoparticles and films of a select group of materials which include the noble metals Ag, Cu, and Au as well as the so-called transparent conducting metal oxides that include Sn-doped In2O3 (ITO), Al-doped ZnO (AZO), and Nb-doped TiO2 (NTO). Localized surface plasmons are excited when light is incident on metallic nanoparticles which typically have dimensions smaller than the wavelength of the incident light. At certain characteristic wavelengths, one or more resonant modes are excited in the nanoparticles, leading to a significant enhancement in absorbed and scattered light and a strong increase in the electromagnetic fields in the vicinity of the particles. Localized surface plasmons can be detected as resonance peaks in the absorption and scattering spectra of the metallic nanoparticles. Nanostructures made up of noble metals, such as gold, silver, and copper, and the more recently discovered conducting metal oxides such as ITO, AZO, and NTO are well known to exhibit localized surface plasmon resonance (LSPR) phenomena.
The collective oscillation of the free electrons is also sensitive to changes in the size and shape of the particle. For example, gold nanoparticles embedded in a transparent matrix phase with a real dielectric constant similar to that of SiO2 (ε˜2.25) and average diameters in the range of approximately 5-10 nm, strongly absorb at visible wavelengths with a maximum absorbance near 520 nm. In this particular case, the energy required to excite the surface plasmon lies in the visible region of the spectrum but the surface plasmon resonance energy can also be tuned to occur at wavelengths ranging from ultraviolet to near-infrared. With increases in the Au particle size, a shift in the peak of the optical absorption to longer wavelengths is observed due to the excitation of higher-order resonant modes. The relative magnitude of the scattering cross-section also increases as compared to the absorption cross-section resulting in particles that strongly scatter light rather than absorb it for particle sizes approaching 100 nm. The plasmon resonance band is also sensitive to particle shape. For example, an elliptical or rod-shaped particle can exhibit two characteristic plasmon resonance bands at distinct wavelengths depending upon the orientation of the particle with respect to the polarization state of incident electromagnetic radiation. In addition to being size- and shape-dependent, the plasmon resonance band is sensitive to changes in the dielectric properties of the surrounding medium. For transparent matrix media with large dielectric constants, the energy required to collectively excite the electrons is decreased thereby shifting the peak in the extinction cross-section to lower energies and longer wavelengths.
The strong dependence of the optical extinction peak on a number of material dependent parameters provides the nanoparticles with an inherent sensing ability. For visible light, generally only changes in refractive index occurring at distances within about 200 nm of the particle surface result in changes to the optical properties of the nanoparticles. The plasmon resonance behavior of nanoparticles are particularly sensitive to adsorption directly on the particle surface and hence biological sensing based on analyte absorption by nanoparticles and subsequent modifications of the absorbance maximum is currently an area of significant effort.
Changes in the absorbance maxima generated by the localized surface plasmon resonance effect have also been utilized extensively for gas sensing applications in the low and intermediate temperature ranges. A select few researchers in the field have also applied Au incorporated films to optical gas sensing at higher temperatures. Current technical literature suggests that the gas sensing response of technically useful noble metal/metal oxide composite films depend significantly upon the selection of a matrix phase that can play an active role in the gas sensing process. Two potential ways that such an active role can be played include (1) a change in the free carrier density of the matrix phase followed by an electronic charge transfer from the matrix to the nanoparticle and (2) a change in the effective dielectric constant of the matrix phase. Both of these effects would result in a modification to the extinction peak of noble metal nanoparticles associated with the localized surface plasmon resonance effect that could be detected through optical based monitoring techniques. However, direct interactions between the metallic nanoparticles and chemical constituents of the ambient gas atmosphere may also be important under certain testing conditions. For example, direct adsorption of chemical species on Au nanoparticles resulting in electronic charge transfer may impart significant modifications to the extinction peak of Au-nanoparticles in the case of Au-nanoparticle incorporated inert oxides such as SiO2 and Al2O3 where interactions between the matrix and the ambient atmosphere are significantly reduced as compared to catalytically active and reducible oxides such as TiO2, YSZ, and ZnO. Such direct interactions are expected to be particularly important in the case of conducting metal oxide nanoparticle incorporated films as relatively large changes in free carrier density of the conducting metallic oxides in response to changes in the chemical composition of ambient gas atmospheres at elevated temperatures have been observed.
For high temperature (T>˜500° C.) optical gas sensing, Au nanoparticles have been embedded in catalytically active, reducible, and oxygen ion conducting matrices such as TiO2 or yttria-stabilized zirconium (YSZ). Dielectric matrix phases with a relatively wide bandgap and low oxygen ion and electronic conductivity commonly referred to in the literature as "inert" such as SiO2, Al2O3, and Si3N4 are expected to exhibit improved temperature and chemical stability. Recent work has therefore also employed Au nanoparticles embedded in an inert oxide matrix such as SiO2 and Al2O3 for gas sensing at temperatures as high as approximately 900° C. For lower temperatures, gold nanoparticles have been embedded in matrices of even more highly reducible oxides such as NiO, WO3, or CuO. See e.g., Sirinakis et al., "Development and Characterization of Au-YSZ Surface Plasmon Resonance Based Sensing Materials: High Temperature Detection of CO," J. Phys. Chem. B 110 (2006); and see Ohodnicki et al., "Plasmonic Nanocomposite Thin Film Enabled Fiber Optic Sensors for Simultaneous Gas and Temperature Sensing at Extreme Temperatures", Nanoscale 5 (19) (2013); and see Ando et al., "Optical CO sensitivity of Au-CuO composite film by use of the plasmon absorption change," Sensors and Actuators B 96 (2003); and see U.S. Pat. No. 7,864,322 B2 to Carpenter et al.; and see U.S. Pat. No. 8,411,275 B1 to Ohodnicki et al.
In addition to noble metals that are commonly known to exhibit a surface plasmon resonance, oxides with a relatively high electronic conductivity have also been demonstrated to exhibit pronounced surface plasmon resonances. These material systems have also been demonstrated to display enhanced high temperature optical gas sensing responses as compared to corresponding oxide systems with a relatively low electronic conductivity and free carrier concentration. See e.g. Ohodnicki et al., "Plasmonic transparent conducting metal oxide nanoparticles and nanoparticle films for optical sensing applications", Thin Solid Films 539 (2013); also see U.S. Pat. No. 8,638,440 to Ohodnicki et al. Optical sensors based upon this class of materials may show improved stability under high temperature and/or chemically aggressive harsh environment conditions in some cases due to a relatively high melting point as compared to the noble metals Ag and Au and a potential for improved corrosion resistance under certain conditions.
The temperature of a gas stream is another parameter that is important to measure in addition to the chemical composition and many different types of temperature sensors have been demonstrated and are used in practice for such applications. For example, thermocouples and resistive temperature detectors are traditional temperature sensing devices that are widely employed in which temperature can be monitored by an electrical signal that consists of a current or voltage. In many cases, it would be advantageous to monitor temperature through optical means without the need for electrical wires or signals at the location where the temperature is being monitored. For example, the use of electrical wires and signals presents a potential safety hazard in the case of flammable gas atmospheres. As another example, application of electrical based sensors in extreme high temperature environments greater than approximately 500° C. can require expensive insulation, electrical wiring, and interconnections which are also a common source of sensor failure under high temperature conditions. To overcome the disadvantages and limitations of such traditional temperature sensing approaches, a number of optical based temperature sensor methodologies have been developed. Methodologies that are compatible with optical waveguide based sensing platforms such as optical fibers for remote and distributed sensing capability are particularly advantageous. One approach to optical temperature sensing that has been explored by prior investigators consists of the development of sensors that enable monitoring of the optical transmittance or reflectance of metallic or dielectric materials. For example, an optical temperature sensor based upon measuring the temperature dependent reflected signal from an end-coated and cleaved optical fiber of a monolithic film of a dielectric material such as TiO2 with a temperature dependent refractive index has been reported. Optical temperature sensors based upon a temperature dependent band-gap of a dielectric material such as ZnO have also been reported. See e.g., M. Naci Inci et al., "A fibre-optic thermometric sensor based on the thermo-optic effect of titanium dioxide coatings", Optics & Laser Technology 29 (3) (1997); and see e.g. S. Chenghua et al., "Optical temperature sensor based on ZnO thin film's temperature dependent optical properties", Rev. Sci. Instrum. 82 (2011). Temperature sensors that are based upon monitoring the optical reflectance of continuous thin films of a metal such as Au or Ag which are well known to display a surface plasmon resonance have also been proposed and are advantageous due to a relatively high theoretical sensitivity of optical transmittance or reflectance to temperature. See e.g. S. Ozdemir et al., "Temperature Effects on Surface Plasmon Resonance: Design Considerations for an Optical Temperature Sensor", Journal of Lightwave Technology 21 (3) (2003); and see e.g. A. Sharma et al., "Theoretical model of a fiber optic remote sensor based on surface plasmon resonance for temperature detection", Optical Fiber Technology 12 (2006). Such approaches can be effective for monitoring of temperature under certain conditions, but it would be advantageous to provide an alternative optical-based methodology that employs temperature sensing materials which exhibit improved temperature stability, chemical stability, and/or additional functionality as compared to continuous films of a dielectric material such as ZnO or TiO2 or continuous films of a metal displaying a surface plasmon resonance such as Ag or Au. It would be further advantageous if the optical methodology were relevant for monitoring of temperature over a broad range of temperatures spanning from cryogenic to extreme, high temperature conditions greater than approximately 500° C. by monitoring the optical properties of the nanocomposite.
Such advantages can be provided by metal nanoparticle incorporated dielectric nanocomposite materials of the type extensively investigated for elevated temperature chemical sensing applications such as Au/TiO2, Au/YSZ, and Au/SiO2. An optical temperature sensor employing a subset of such materials systems has been discussed theoretically by previous authors, but in that case the temperature sensing mechanism involved a particle size that varied with temperature due to coarsening. Such temperature dependent particle coarsening would impart a time-dependent optical signal at fixed temperature and an irreversible temperature response with increasing temperature that would prevent a useful and reversible temperature sensing response. See e.g. S. K. Srivistava et al., "Simulation of a localized surface plasmon resonance based fiber optic temperature sensor", Journal of the Optical Society of America 27 (7) (2010). It would instead be advantageous to employ metal nanoparticle incorporated sensor materials for which the particle size does not vary significantly under the testing conditions employed. Stabilization of the particle size can be achieved, for example, through dielectric matrix selection (thickness, composition, etc.) and high temperature pre-treatments of the nanocomposite temperature sensor material. See e.g. Ohodnicki et al., "Plasmonic Nanocomposite Thin Film Enabled Fiber Optic Sensors for Simultaneous Gas and Temperature Sensing at Extreme Temperatures", Nanoscale 5 (19) (2013); also see Ohodnicki et al., "Plasmon Resonance at Extreme Temperatures in Sputtered Au Nanoparticle Incorporated TiO2 Films", Proceedings of SPIE Optics and Photonics 8456 (2012); also see Buric et al., "Theoretical and experimental investigation of evanescent wave absorption sensors for extreme temperature applications", Proceedings of SPIE Optics and Photonics 8816 (2013); also see Buric et al., "Optical fiber evanescent absorption sensors for high-temperature gas sensing in advanced coal-fired power plants", Proceedings of SPIE Optics and Photonics 8463 (2012).
It would be further advantageous if an optical interrogation methodology allowed for multiple parameters to be monitored simultaneously through multiple wavelength interrogation in these and related materials by exploiting the detailed wavelength dependence of optical properties of a nanocomposite material. For example, it would be advantageous if such an optical interrogation methodology would allow for simultaneous monitoring of the temperature and chemical composition of a gas stream or a liquid phase.
Under most conditions, nanoparticles of metals such as Pd, Pt, Rh, Ru, Os, and Ir do not display a pronounced absorption or scattering localized surface plasmon resonance. As such, nanocomposite films consisting of nanoparticles of these metals dispersed in a dielectric matrix phase have not been extensively investigated for optical sensing applications. However, many of these metals exhibit relatively high melting points as compared to the noble metals Au and Ag for which localized surface plasmon resonances are well known to occur. It would therefore be advantageous to develop materials with useful high temperature optical sensing responses based upon this class of materials, particularly for applications in the most demanding temperature ranges where typical noble metals such as Ag and Au may undergo melting
Disclosed here is a method for temperature sensing utilizing optical signal shifts that are associated with temperature dependent optical properties of a metal nanoparticle incorporated nanocomposite material. The temperature sensing material is comprised of a plurality of metallic nanoparticles dispersed in a dielectric matrix. The method disclosed offers significant advantage over materials typically utilized for temperature sensing, including enhanced thermal and chemical stability of the dielectric matrices due to embedded metallic nanoparticles, increased chemical and size stability of metallic nanoparticles embedded in a dielectric matrix, and the capability for simultaneous monitoring of temperature and chemical composition of a gas stream or a liquid through multiple wavelength interrogation, among other advantages. In addition, several candidates for dielectric matrix materials (e.g. SiO2, Al2O3, MgF2 doped SiO2, mixed SiO2/Al2O3) exhibit relatively low values of refractive indices for fully densified films ranging from less than ˜1.5 to greater than ˜1.7. This property is advantageous as it enables integration of nanocomposite films directly with optical fiber based sensors as a gas sensitive cladding layer in an evanescent wave absorption spectroscopy based sensing configuration, while maintaining the conditions necessary for waveguiding in the low refractive index core material. These and other objects, aspects, and advantages of the present disclosure will become better understood with reference to the accompanying description and claims.

Nanocomposite thin films for optical temperature sensing