This invention provides a thin metallic sheet structure having excellent sound damping characteristics which can lower the sound pressure level of a sound inherent to a thin metallic sheet structure when this structure is patted, and can quickly damp the sound by a simple structure. In a flat sheet-like or box-like structure comprising a thin metallic external sheet and beams for reinforcing the external sheet, a thin metallic sheet structure having excellent sound damping characteristics according to the present invention employs the construction wherein the reinforcing beams 2 are brought into contact with one of the surfaces of the thin metallic external sheet 1 through a sound damping sheet 3, and the coupling state between the sound damping sheet 3 and the thin metallic external plate 1 or the reinforcing beams 2 is a non-coupling state or a discrete coupling state on at least one of the surfaces of the sound damping sheet 3.

Outer steel structures using thin metallic sheets such as a steel sheet, for durable consumer goods such as automobiles, building materials, furniture, electrical appliances, etc, have been again examined in recent years because they are advantageous from the aspects of recycling properties, removal of detrimental substances in processing of the wastes, and ecology. When means for reducing the thickness of a metallic external sheet by supporting the external sheet by reinforcing beams so as to reduce the weight is employed, tapping the metallic external sheet is likely to spoil the commercial value of products since the metallic external sheet is generally as thin as about 1 mm. In other words, when such a thin metallic sheet is tapped or patted, a sound inherent to the metal (the sound is an offensive and low-grade noise because it is not heavy and low) occurs, and the value of the product itself might be spoiled by this noise. Particularly in the case of products for home use, tone quality and quietness of the tapping sound of the external plate, which is generated for some reason or other, is one of the important factors for providing a feeling of high quality to the product.
A sheet material produced by sandwiching a resin film between thin metallic sheets and called a "vibration-proofing steel sheet" has been used in the past as the metallic external sheet satisfying the object described above. When this material is used, sound damping characteristics can be remarkably improved, but the material is not free from the problems that the cost is high, machining performance such as bendability, drawability, etc, is inferior to a single sheet because it is a sandwiched metallic sheet, and sharp bending and drawing cannot be carried out.
Japanese Unexamined Patent Publication (Kokai) No. 62-27143 discloses a composite vibration-proofing steel sheet which can withstand bend-machining at a small bending radius by simultaneously heating and shaping a metallic sheet and a vibration-proofing material without using an adhesive, and Japanese Examined Utility Model Publication (Kokoku) No. 6-49743 describes a steel sheet for a floor produced by the steps of applying a polymer resin to a part of a bent steel sheet to obtain a thin steel sheet and bonding the thin steel sheets by a polymer resin so as to damp a sound.
These proposals are based on the premise that the thin steel sheets and a plastic material as the vibration-proofing material are finally bound together. When the structure requiring an adhesive is employed, the increase of the cost of the adhesive and the drying time render the disadvantages for the production, and deterioration of the adhesive might occur depending on temperature and the passage of time. In the case of electric home appliances, in particular, electrical components inside the casing exist under exothermic condition, and counter-measures for thermal degradation of the adhesive and for possible fire hazards become necessary.
Further, Japanese Unexamined Patent Publication (Kokai) No. 61-182820 discloses an invention wherein the ratio of thickness of three layered steel sheets is selected within a specific range and these steel sheets are locally fused so as to improve vibration-proofing performance by utilizing the friction between the metallic sheets. However, the use of the laminated steel sheets is not preferable for those products whose weight must be reduced, and various problems are yet left unsolved for applying this invention to products for which machinability and appearance are of importance.

Thin metallic sheet structure having sound damping characteristics


According to one embodiment, a content recording apparatus includes a management module configured to manage information on content that is transferred from a source apparatus and stored in a storage device, and the content the source apparatus has, a recording module configured to record the content transferred from the source apparatus to the storage device in the inactive state and to retain the content in the source apparatus, and a control module configured to issue a command to the source apparatus based on the information on the content managed by the management module if the user determines that the content is used, the command being intended to deactivate content the source apparatus has, and configured to activate the content stored in the storage device in response to deactivation of the content the source apparatus has.

1. Field
One embodiment of the invention relates to a video content recording apparatus which records copyright-protected video content transferred from a source apparatus, and a video content transfer method.
2. Description of the Related Art
Content currently available via digital terrestrial and digital DBS broadcasting is copyright-protected and may not be duplicated. In order to use the content on an apparatus different from the one on which it was recorded, the content must be moved in advance.
When moving copyright-protected content between apparatuses through a network or the like, a content moving method defined by various standards is typically used so that unauthorized copies cannot be made.
Initially, the destination apparatus issues a transfer request for the content to the source apparatus. In response, the source apparatus transfers the content to the destination apparatus. Here, the destination apparatus records the content but not in a usable state (referred to as the inactive state, the usable state in the source apparatus, on the other hand, being referred to as the active state). The processing so far will be referred to as transfer processing.
After the entire content has been transferred, the destination apparatus issues a deactivation request for the content to the source apparatus. In response, the source apparatus deletes the content and reports the deletion to the destination apparatus. The destination apparatus makes the content usable. The processing so far from the end of the transfer processing will be referred to as move confirmation processing.
This method eliminates the period where usable content coexists in both apparatuses, and can thus move the content while preventing the creation of unauthorized copies. The content moving method described above will be referred to as a transaction-based move.
Since it takes time to move content, it is inconvenient, entailing a long wait, to move content from scratch after a need arises to use the content.
Suppose, for example, that one wishes to move content from a DVD recorder or the like to a cellular phone when going out and to view the content with the cellular phone away from home. He/she then needs to wait for the transfer time if the content moving operation is performed from scratch before going out. For example, when an hour's content recorded at 25 Mbps is transmitted through a 100Base network with an effective rate of 50 Mbps, the transfer time to wait up to the end of the transfer is as much as approximately 30 minutes.
With copiable content, it is possible to copy all the content to the destination apparatus anyway instead of moving. The content then can be selected anytime to keep the needed for use and delete the unneeded. The content deleted from the destination apparatus will not be completely lost since the same content is still in the source apparatus.
Content that can only be moved, on the other hand, will be lost permanently from both the apparatuses if it is moved in advance and then deleted during selection, being determined not to be used this time. To avoid this, if the content is kept undeleted in the destination apparatus, the storage capacity will be wasted. Moving the content back to the original apparatus for this reason eventually takes time.
Jpn. Pat. Appln. Laid-Open Publication No. 2006-185473 discloses a technique for reducing the waiting time of move processing in a digital content recording and reproducing apparatus, by moving content under reproduction while maintaining a move condition even during reproduction.
The technique disclosed in Jpn. Pat. Appln. Laid-Open Publication No. 2006-185473 is not a fundamental solution, however, since the time from the occurrence of a need to the completion of a move is unchanged.

Video content recording apparatus and video content transfer method


A rack for the storage and display of compact disc cases includes a grid of horizontal and vertical bars to form a plurality of cells each sized to receive a compact disc case for display. A lip extending laterally from a vertical bar of each cell which defines a recess in the cells for receiving edge portions of compact disc cases. A spring is mounted to the grid within each of the cells for biasing the compact disc case placed therein against the lip.

Compact discs are circular, flat plastic discs on which information is recorded. The information can be interpreted by compact disc players as audio, video, or text. Compact discs are commonly used to distribute music, computer software, and research information. Compact discs sold to consumers are typically contained in a standardized type of storage case. These types of storage cases include cardboard envelopes, plastic jackets with pockets for receiving discs, and plastic boxes or cases. For example, computer software is typically provided in an envelope or jacket. On the other hand, in the fields of music, computer research materials, and computer games, compact disc recordings are often contained in plastic boxes (or cases) having a hinge along one side. Such cases are generally referred to as jewel box-style compact disc cases. The jewel box compact disc case opens along a hinge to reveal a compact disc held within a molded internal frame. The case may be characterized as a clam-shell case. The case has a front cover side, and an opposing back side that is parallel with the front cover side. The front side and the back side pivotally connect on the hinge side or "spine." Compact disc cases often contain an ornamental front display insert which is used to identify the performing artist, musical group, or research material which is recorded on the compact disc. The front display insert is secured within the disc case. The jewel box case also often includes a short descriptive title of the compact disc recording along its spine and front edge. For compact disc sets of two or more compact discs, the jewel box-type case typically includes "page" portions that are pivotally moveable about the spine.
There are various devices used for storing collections of compact discs. One device provides an envelope with pockets for receiving the discs. However, many people prefer to store the discs within the jewel box. Often the jewel boxes are placed side-by-side in a book case or storage rack. The jewel boxes are preferably oriented with the spine outward for use in selecting discs.
Often persons store jewel box cases in slotted-style, tower-type racks. The tower-type racks typically have narrow columns with slotted receptacles for receiving the jewel box cases. These compact disc towers dispose the compact disc cases either in a vertical side-by-side arrangement or in a horizontal top-to-bottom arrangement. The cases are preferably inserted so that the side text on the spine side may be visible. While such storage allows for efficient use of space, selection of a particular compact disc is often difficult. Because the text on the spine of compact disc cases is small, the titles are often difficult to read. A user also has to bend his head into a cocked position in order to read the vertical spines of the cases, or may have to stoop to read the horizontal spines of the cases. Furthermore, while the storage of discs in a tower or shelf is an efficient use of space, it prevents the viewing of the artistic cover which often adorns the front cover side of compact disc cases. Also, extraction of a compact disc case from towers or stacks requires grasping the lateral sides of the disc and pulling outwardly. This often is cumbersome due to the close spacing of the compact disc cases in the tower.
Storage racks have been developed which allow for the display of jewel-box compact disc front cover sides. Such racks allow for quick selection of a compact disc case by recognition of a cover design. Furthermore, such display racks serve an aesthetic purpose by providing wall ornamentation. However, such racks often require two hands to manipulate the compact disc case in and out of the rack. Also, some such display racks do not provide for the storage of multi-disc sets. Furthermore, such racks often utilize complex mechanisms or shelves to hold the disc cases on the rack, or require alteration of the compact disc cases themselves to allow for storage of a disc case within the rack. In one type of these shelf racks, if it is accidentally jarred, the jewel boxes fall from the rack.
Furthermore, some compact discs in the field of computer research materials and software are sold in jewel box style cases. Such computer research material discs are usually packaged with supporting literature in boxes many times the size of the compact discs contained therein. Storage of computer discs in such boxes is impractical given the limited space usually present adjacent to a computer drive for reading compact discs. Storage of computer discs in a compact disc storage tower is also impractical, since the jewel boxes containing such discs often lack sufficient identifying language along their spine to readily ascertain their contents. While such computer discs could be stored in a floppy-disc type holder, such storage requires a user to flip through a series of titles before accessing the needed disc.
Accordingly, there is a need in the art for a storage rack which provides secure retention of compact disc cases with display of front covers for aiding selection of discs while the storage rack facilitates access and removal of selected cases of discs.


Write transactions are conducted by transmitting a first write address from a source device over a first bus on a first clock cycle and transmitting a first data word corresponding to the first write address from the source device over a second bus commencing on a later clock cycle. In order to execute write transactions in this manner, a memory unit is modified to contain a pending write buffer and a memory array. During a write transaction, the address and corresponding data is first stored in the pending write buffer and the data is later transferred into the memory array upon subsequent write transactions. During a read transaction, the read address is compared to the address stored in the pending write buffer. If the read address matches the address stored in the pending write buffer, the corresponding data stored in the pending write buffer is transmitted in response to the read request. If there is no match, corresponding data from the memory array is transmitted.

1. Field of the Invention
This invention relates generally to digital data processing systems and more specifically, to a method and apparatus for increasing the speed of memory transactions within a computer system.
2. Background Information
As the computer revolution has progressed, the quest of computer hardware developers has been to develop computer systems exhibiting more processing power and faster performance. In order to increase the speed of computer systems, developers place great emphasis in efficiently using the available clock cycles of the central processing unit (processor) to execute the necessary instructions.
A digital data processing system typically consists of a processor and a memory unit. The memory unit stores data in addressable storage locations, and transfers the appropriate data to and from the processor on a data bus upon request by the processor. The processor issues a read request to the memory unit by transmitting an address over the address bus at one clock cycle. The memory unit receives the address, and commences to transmit the corresponding data to the processor on the next clock cycle. FIG. 1A shows a clock diagram for a read transaction.
A write transaction between the processor and the memory unit is carried out differently. The processor issues a write request by transmitting the address and data on the same clock cycle over the address bus and data bus, respectively. FIG. 1B shows a prior art timing diagram for write transactions.
A sequence of mixed reads and writes cannot run at full speed because each type of transaction makes use of the data bus at different times. For example, in order to issue a write request immediately following a read request, the processor must wait until it receives the read data requested from the memory unit. During this process, at least one available clock cycle is wasted, thus decreasing the overall system performance. In order to issue a read request immediately following a write request, the processor must wait until the write transaction is completed at the memory unit. During this process, one available clock cycle is wasted, again slowing the overall system. Therefore, it would be desirable to have a computer system which makes more efficient use of available clock cycles whenever there is a mixture of read and write transactions.

Pipelining to improve the interface of memory devices


A surgical vision system for imaging heat capacity and cooling rate of tissue has an infrared source configured to provide infrared light to tissue, the infrared light sufficient to heat tissue, and an infrared camera configured to provide images of tissue at infrared wavelengths. The system also has an image processing system configured to determine, from the infrared images of tissue, a cooling or heating rate at pixels of the images of tissue at infrared wavelengths and to display images derived from the cooling rate at the pixels.

Laparoscopic surgery has become common for minimally-invasive procedures. Laparoscopic surgery involves making a small number of small incisions, inserting surgical tools and a laparoscopic vision device having a light source and imaging apparatus through these openings to a surgical site, and then performing surgery within a body cavity. The body cavity is often enlarged by administering gas, such as carbon dioxide, to give the surgeon a larger, more exposed field of view. The surgical tools are typically manipulated directly by the surgeon or indirectly through a robotic-coupled apparatus that articulates based on how a surgeon manipulates a set of "joysticks". Laparoscopic surgery (both manual and robot-assisted) is particularly common for abdominal and pelvic procedures, including cholecystectomy and radical prostatectomy.
Similarly, endoscopic surgery has also become common for minimally-invasive surgical procedures in body cavities that communicate outside the body through a body opening. Endoscopic surgery involves threading an endoscope through the opening to a surgical site. The endoscope is a flexible device equipped with a light source and imaging apparatus, and typically having a lumen through which a gas, such as carbon dioxide, can be admitted to inflate the cavity to enable improved vision and through which a surgical tool may be threaded. Typically, an endoscope has manipulation or steering wires running from its head to a handle attached to its base so that the endoscope tip may be twisted or straightened by moving knobs on the handle. This allows threading of the endoscope through the body opening to the surgical site. Once the endoscope is threaded to the surgical site, surgical tools are threaded through the lumen of the endoscope and manipulated to perform the desired surgical procedure. The surgeon uses images obtained by the imaging apparatus of the endoscope to verify correct placement of the surgical tools, and to guide the surgery. Endoscopic surgery is often used for polypectomy in the colon, as well as transurethral prostatectomy and transurethral removal of bladder tumors (TURBT). Endoscopes are also often used for biopsies, including biopsies of the lung, colon, esophagus, and stomach. Endoscopes may be used for many other procedures than those listed here.
In typical laparoscopic and endoscopic procedures, a surgeon views the surgical site using the light source and optical imaging apparatus, and performs surgery under direction of images acquired by the imaging apparatus. The imaging apparatus used for the majority of endoscopic and laparoscopic procedures provides the surgeon with two-dimensional images of the surgical site. Recent robot-assisted systems have provided surgeon with a three-dimensional view of the surgical site through stereovision imaging devices. Since surgery is typically directed in accordance with optical images, it is desirable to have good contrast in the images between lesions or tissue needing removal and normal tissue of the subject that the surgeon intends to leave intact. While some tissues, like the gall bladder, have sharp color contrast relative to other nearby tissues, such as normal liver tissue, many other lesions and tumors have little color contrast relative to nearby tissues. Additionally, tissue surfaces are often difficult to visualize in images due to blood and other substances coating the surface.
In addition to contrast between normal and lesion tissue, it can be desirable to resolve differing types of normal tissues so that anatomy can be confirmed, or critical structures, such as nerves and blood vessels, can be left undamaged during the procedure.

This patent is subject to a terminal disclaimer.


A method for fabricating a semiconductor device includes forming first contacts to a heater for programming, and forming second contacts to a phase-change material layer for resistance readout. The phase-change material layer is formed in proximity to the heater, and the first contacts are electrically isolated from the second contacts to provide separate programming and resistance readout control.

The present invention generally relates to semiconductor devices, and more particularly to memory devices and methods of forming the same.
A memory cell is a component of a computer memory device that includes an electronic circuit that stores one or more bits of digital information. The memory can be a volatile memory or a non-volatile memory. A volatile memory requires power to maintain its state, while a non-volatile memory maintains its state even if the device is powered off. One example of non-volatile memory is phase-change memory (PCM). PCM can exploit semiconducting properties of phase-change materials, such as, e.g., chalcogenide glass, that include amorphous and crystalline phases. Information can be stored by setting the phase change material into one of the two phases: the amorphous phase (high resistance) or the crystalline (low resistance) phase. The switching between the two phases can be achieved by applying a current pulse. Information can be read by measuring a resistance of the PCM cell. PCM technology can be used for, e.g., electronic synapse devices, memristors for neuromorphic or analog computing, and high-density/high-speed non-volatile memory applications.

Memory device having separate programming and resistance readout control

International Business Machines Corporation


Some elevator buckets 1, 11, 21, 31, 41 have aperture orifices 2, 3, 4, 12, 22; 42, 43, 44, 52. Traditionally, these aperture orifices are formed by drilling a solid bucket wall but by provided aperture features 12′, 13′, 52′ in a moulded bucket with some already moulded aperture orifices then some markers or pre-cursors for aperture orifices are provided and provision of elevator buckets is more efficient with aperture orifices.

This invention relates generally to elevator buckets and more particularly to methods of making and elevator buckets used in conveyor systems for bulk materials such as grains, gravel and the like.
Conveyor systems are widely used to move loose bulk materials about docks, silo facilities, quarries and other industrial plants. The conveyor is a belt or chain upon which elevator buckets are located at spaced positions so that the bulk materials can be lifted that is to say elevated to a height for loading or otherwise. It will be appreciated the nature of bulk materials means that the buckets must be robust and hardwearing but also relatively cost effective. Thus, elevator buckets tend to be made of robust metals such as steel or aluminum or moulded with tough plastics materials in standard forms and sizes.
There can be circumstances where a more specifically designed elevator bucket for a particular situation would be desirable. For example, the bulk materials will be dumped into and will be dumped/drop evacuated from the bucket and such sudden loading or un-loading may create issues with trapped air in the bottom of the elevator bucket. Trapped air may marginally reduce the amount of material picked upon by the bucket and this could have significant effects upon the overall performance of a conveyor system running at high rates. Similarly with sudden dumping of the bulk material there may be a slight transient vacuum suction at the bottom of the elevator which may mean that the conveyor system needs to be operated at a marginally slower rate. However, possibly the biggest issue with wet materials is that there may be pooled water which adds to moved weight so energy needs and costs but also possibly aggravates the above problems. A solution is to provide elongate aperture in the bottom of the elevator bucket but not all elevator buckets need elongate aperture and so rather than originally forming buckets with elongate aperture these elongate aperture are formed by drilling whilst other hole formation techniques are not suitable due to the robust materials and thicknesses of bucket walls.


A method of operating a communication system comprises receiving a plurality of traffic, processing each traffic of the plurality of traffic to determine if a delay of the traffic exceeds a delay limit, discarding the traffic if the delay exceeds the delay limit, retaining the traffic if the delay does not exceed the delay limit, incrementing a late counter from a base amount of the late counter when the delay exceeds the delay limit, incrementing a retained counter from a base amount of the retained counter when the delay does not exceed the delay limit, returning the late counter to the base amount of the late counter when the delay does not exceed the delay limit and when the delay of a previous traffic exceeded the delay limit, clearing the retained counter to the base amount of the retained counter when the delay exceeds the delay limit and when the previous traffic did not exceed the delay limit, increasing the delay limit when the late counter exceeds a late limit, and decreasing the delay limit when the retained counter exceeds a retained limit.

1. Field of the Invention
The invention is related to the field of communications, and in particular, to systems that dynamically adjust backhaul delay parameters.
2. Description of the Prior Art
Communication service providers, such as wireless telecommunication carriers, common carriers, cable multi-service operators, or the like, typically strive to provide high quality communication services. Factors from the quality of a handset used on a wireless call to congestion levels experienced on a network could negatively impact the quality or performance of a particular communication.
In many cases, establishing and perfecting the timing of various network operations plays a large role in determining the overall quality of a communication. In one particularly problematic area, determining and setting appropriate levels of allowed backhaul delay has become increasingly difficult as instances of diverse backhaul have become more common.
Typically, backhaul traffic is transmitted, transported, or carried in discrete part, such as packets, frames, or timeslots, depending upon the type of the backhaul. Regardless of the form of the discrete traffic, when received at a receiving end, such as a device or a central communication node, each portion of traffic has a delay relative to when the traffic left or was sent by the transmitting end of a link. Traffic delay is a well known concept in the art.
In many situations, traffic delay impacts the performance or quality of a communication. In a video example, too much traffic delay could cause jitter or other undesirable characteristics at the receiving and viewing end of the video. Likewise, too much traffic delay could cause interruptions in voice calls. In the case of mobile telephony, roaming functions, such as hand-offs between base stations, could be impacted. Other consequences of delay are well known.
In an effort to lessen the consequences of traffic delay, many communication systems simply discard traffic having a delay that exceeds an acceptable delay parameter or window. Typically, it is desirable to set the delay window as small as possible. However, a delay window that is too small will result in too much discarded traffic. While a large delay window results in little discarded traffic, slow traffic can lead to other system or network degradations. Thus, network engineers are constantly challenged with setting delay windows to appropriate levels.


An optical camera three-dimensional coordinate measuring system for use with objects to be measured is described. The system may include a compact, easily moveable, and rotatable, target of known dimensions comprising a spherical surface to be placed in contact with the object to be measured at different points along the object to be measured thereby eliminating the necessity of using a larger extended probe contact tip extending from the target to the object to be measured. At least one or more light emitting source may be located in a known position in the target such as the center of the spherical surface for example. At least two cameras located at different and known coordinate locations for receiving light from the light emitting source from different optical perspectives may be included. The position in three dimensional coordinates of the object to be measured is computed from the images taken by the cameras.

There is a class of portable devices that accurately measure three-dimensional coordinates to a range of several tens of meters. Such devices are ordinarily referred to as portable large-scale coordinate-measuring machines (CMMs). One type of portable CMM is the laser tracker. It sends a laser beam to a retroreflector target, which may be a spherically mounted retroreflector (SMR) comprising a cube-corner retroreflector centered within a sphere that is moved over the surface of interest. Alternatively the target may be a retroprobe, which comprises a cube-corner retroreflector positioned near a mirror to form a virtual image of a probe tip (U.S. Pat. No. 5,530,549).
A second category of portable CMM is the camera and multiple-light probe (U.S. Pat. No. 5,440,392). This device comprises a probe, which contains a probe tip and at least three point sources of light, together with one or more cameras that view the point sources of light. The image pattern on the camera is used to determine the position of the probe tip in space.
A third category of portable CMM is the laser tracker with a separate but nearby camera. (U.S. Pat. No. 5,973,788). This device comprises the laser tracker, a camera mounted near the laser tracker, and a probe. The probe comprises a probe tip, at least three point sources of light, and a retroreflector. A laser beam from the laser tracker measures the three-dimensional coordinates of the retroreflector. At the same time, the camera measures the three-dimensional coordinates of the light sources on the probe. The information from these measurements allows the coordinates of the probe-tip in space to be determined. A related idea (U.S. Pat. No. 5,973,788) is to embed the camera into a laser tracker that also contains an absolute distance meter.
Four attributes are desirable in a portable CMM: (1) low price, (2) high accuracy, (3) rapid data collection, and (4) ease-of-use. Today the least expensive of these devices costs nearly $100,000. Some devices collect data too slowly to be used to efficiency determine the coordinates of three-dimensional contours. Other devices have relatively poor accuracy. There is a need today for a new type of instrument that is fast, accurate, and much less expensive than current portable CMMs.
Some advantages of the present three-dimensional coordinate measuring device compared to prior art are discussed herein, however this is not intended to be a limiting or exhaustive listing of advantages. There are several companies that make camera-based metrology systems. One of the highest accuracy Metronor systems uses two cameras, which can be placed on a factory floor for example. In this respect, the Metronor system is like the present device. However, the Metronor system is based on a probe with a tip that is not illuminated. The find the location of this tip, the Metronor system must be capable of accurately determining the pitch, roll, and yaw angles of the probe from the camera images of multiple LEDs located on the probe. To make possible the required accuracy, Metronor makes their probes large enough to cover a relatively large fraction of the field of view of the cameras. Such large probes are cumbersome to manage. Furthermore, the probes need to be stiff and fixed in length over temperature, which means using expensive composite materials.
In most cases a different kind of probe such as the embodiments described below which are not currently used by any camera-based system, would be more useful, convenient, and cost effective than an extended probe such as Metronor's. The simplest such device—the sphere with a light source placed at its center—takes advantage of the fact that the distance from the center to the edge of a sphere is a constant. Thus, the sphere body acts like a spacer of known dimensions between the object to be measured and the light source. Also, the sphere can be turned in any direction. Because of this fact, the spherically mounted light source can be used to measure the contour of almost any object. In some cases, a handle will be also convenient. A similar idea from symmetry leads to the fiducial target, which will typically be put into a pre-established tooling hole. In this case, the light source is located on the rotational axis of symmetry of the target. By measuring the target, it is therefore possible to determine the three-dimensional coordinate of the hole on the tool.
One thing that all of the targets—sphere, probe-mount, fiducial, wide-angle, or retroprobe target—have in common is that all emit light over a wide angle from a single point in space. All of the prior art camera-based probes use multiple points of light. Thus, it has not been obvious to those skilled in the art that such useful and accurate probes could be devised based on a single point-of-light. Proof of this fact is that people have been making camera-based metrology systems for years and that no one has yet implemented such as system, which arguably can be made less expensively and with equal or higher accuracy.

Three-dimensional coordinate measuring device


A panel camera, and an optical touch screen and a display apparatus employing the panel camera. The panel camera includes a lens panel comprising a plurality of narrow-angle lenses arranged in a two-dimensional (2D) array and a light-detection panel comprising a plurality of light detectors which are arranged in a 2D array to respectively correspond to the plurality of narrow-angle lenses to receive lights passing through the plurality of narrow-angle lenses from outside and obtain a remote image.

1. Field
Apparatuses consistent with exemplary embodiments relate to panel cameras, and optical touch screens and display apparatuses employing the panel camera.
2. Description of the Related Art
A touch screen, which is a User Interface (UI), is installed on a front surface of a display of an electronic device such as a computer, a notebook, a Portable Media Player (PMP), etc., to input a particular command or data to the electronic device by sensing a touch point which a finger or a pointing device touches.
With the increasing demand for user convenience, the demand for such a touch screen is also increasing and the application range of the touch screen is expanding to broadcasting, education, medical imaging, pictures, music, moving pictures, virtual reality games, and e-commerce such as Business-to-Business (B2B) commerce or Business-to-Consumer (B2C) commerce.
In the touch screen, touch sensing through touches, such as in capacitive type sensing or resistive type sensing, has been widely used. For more convenient UIs, there is a need for proximity touch sensing for sensing motion of a finger in a non-contact manner and recognition of a user's action from a remote distance.

Panel camera, and optical touch screen and display apparatus employing the panel camera


A voice Telephone Network Applications Platform (NAP) is enhanced to manage facsimile messages, as well as voice messages, by the addition of facsimile functionality to the platform actuatable by high-level facsimile commands from applications supported on the platform. The commands include sending and receiving facsimile messages. A PC facsimile processor (FP), interfacing between the platform and the telephone network, stores facsimile messages received from the network and facsimile messages for transmission to the network on hard disk. A facsimile command from an application is expanded into NAP commands for controlling the platform and FP commands for controlling the facsimile processor so as to perform the facsimile functionality associated with the facsimile command. A recovery process utilizing a Recovery Token prevents facsimile messages from becoming lost between receipt at the FP and storage in the platform.

1. Field of the Invention
The invention relates to providing facsimile (fax) services over the telephone network via application software for such services and involves a telephone network digital computer platform for supporting such application software.
2. Description of the Prior Art
The facsimile machine has become ubiquitous in present day communication for transmission of documents. Facsimile transmission over the Public Switched Telecommunications Network (PSTN) annually generates billions of dollars in toll revenues. A variety of facsimile related services and enhanced services are currently available, such as Call Answer, Fax Store and Forward, Fax Mailbox, and the like. Generally, such services are provided by dedicated systems specifically designed for the service and for the hardware environment in which the system will be deployed. Such systems tend to lack flexibility, in that desired changes in functionality often require extensive, and hence expensive, modifications to the application software. Additionally, application software for providing such services are not portable in that a change in hardware environment usually requires substantial application software re-writing. Although such systems are usually computer based, such systems can only perform the functions for which they were designed and, thus, cannot also be utilized to perform general purpose data processing. Also, such systems generally do not have access to data bases stored on general purpose computers. Additionally, if it is desired to provide a wide variety of services, utilization of a large number of dedicated systems tends to be prohibitively expensive.
Since the divestiture, the Bell Operating Companies (BOCs) and Independent Telephone Companies (Telcos) have been seeking ways to increase the return on their primary asset; viz, the installed network. One source of increased revenue would be to offer new facsimile related services that integrate into, or interface with the existing network, resulting in greater utilization thereof. It is generally difficult for BOCs and Telcos to provide new services because network switches are designed to switch calls, not support data base or special service related functionality. Each Central Office (CO) utilizes a predetermined set of functions provided by the switch manufacturer. Only the manufacturer could add new services to the switching system which usually involves substantial lead times, such as two years or more. Additionally, the switch manufacturers have been particularly slow in responding to the needs of the BOCs and Telcos for enhanced service provisioning. A major limiting factor to providing new facsimile related services is a dependence on the telephone switch provider for implementing the capabilities required by these new services.
In addition to the above disadvantages, it is believed that currently available facsimile service systems do not have the capability of sending and receiving facsimile transmissions over a currently established voice connection. Present day systems are believed to terminate a voice connection and then re-dial a fax machine for the facsimile transmission. It is furthermore believed that present day systems do not have the capability of common storage of voice and fax images in the same data base. Separate facilities are believed to be required. It is furthermore believed that present day facsimile systems effect fax transmissions in an inefficient interactive mode utilizing flow control such as transmitting one Rage at a time.
Although the system of said U.S. Pat. No. 5,138,004 overcomes the disadvantages described above with respect to voice communication, the advantages realized by the platform of said U.S. Pat. No. 5,133,004 for voice has not, prior to the present invention, been achieved for fax.

Telephone network application platform for supporting facsimile applications


The time required for the program verify and erase verify operations can be shortened. The change of threshold values of memory cells can be suppressed even if the write and erase operations are executed repetitively. After the program and erase operations, whether the operations were properly executed can be judged simultaneously for all bit lines basing upon a change, after the pre-charge, of the potential at each bit line, without changing the column address. In the data rewrite oepration, the rewrite operation is not effected for a memory cell with the data once properly written, by changing the data in the data register.

1. Field of the Invention
The present invention relates to a non-volatile semiconductor memory device using a flash EEPROM, and a memory system using such a memory device.
2. Description of the Related Art
Magnetic disks have been used widely as storage means for computer systems. A magnetic disk has the following disadvantages. Namely, it is weak against an impact force because of its highly precise drive mechanism, less portable because of its weight, difficult to drive with a battery because of large power consumption, unable to access at high speed, and so on.
In order to overcome such disadvantages, semiconductor memory devices using an EEPROM have been developed recently. Generally, a semiconductor memory device has the following advantages over a magnetic disk. Namely, it is strong against an impact force because it has no highly precise drive mechanism, more portable because of its light weight, easy to drive with a battery because of small power consumption, able to access at high speed, and so on.
As an example of EEPROM, there is known a NAND cell type EEPROM capable of providing a high integration density. Such an EEPROM has the following structure. Namely, a plurality of memory cells are disposed, for example, in a column direction. The source and drain of adjacent memory cells are sequentially connected in series. With such a connection, a unit cell group (NAND cell) is constituted by a plurality of memory cells connected in series. Such a unit cell group is connected to each bit line.
A memory cell generally has a MOSFET structure with laminated charge accumulation layer and control gate. Memory cells are integrated as an array within a p-type well formed in a p-type or n-type substrate. The drain side of a NAND cell is connected via a select gate to a bit line. The source side of a NAND cell is connected via a select gate to a source line (reference potential wiring). The control gate of each memory cell is connected to a word line arranged in a row direction.
The write operation of a NAND type EEPROM is performed in the following manner. The threshold value or threshold voltage of all memory cells within a NAND cell is set to a negative value by the preceding erase operation. Data is sequentially written starting from the memory cell remotest from the bit line. A high voltage Vpp (about 20 V) is applied to the control gate of the selected memory cell. An intermediate potential VM (about 10 V) is applied to the control gates and select gates of the other memory cells on the bit line side. A potential of 0 V or intermediate potential is applied to the bit line, depending upon the level of write data. When a potential of 0 V is applied to the bit line, this potential is transmitted to the drain of the selected memory cell, so that electrons are injected from the drain to the floating gate. As a result, the threshold value of the selected memory cell is shifted to the positive side. This state is called, for example, a "0" state. If an intermediate potential is applied to the bit line, electron injection does not occur. As a result, the threshold value of the selected memory will not change. Namely, the threshold value takes a negative value. This state is called a "1" state.
In the erase operation, data in all memory cells within the NAND cell are erased at the same time. Namely, 0 V is applied to all control gates and select gates to make the bit lines and source lines in a floating state, and a high voltage 20 V is applied to the p-type well and n-type substrate. As a result, electrons in floating gates of all memory cells are removed therefrom to the p-type well, shifting the threshold values of memory cells toward the negative side.
The data read operation is performed in the following manner. Namely, 0 V is applied to the control gate of the selected memory cell, and a power supply voltage Vcc (=5 V) is applied to the control gates and select gates of non-selected memory cells. In this state, it is checked whether current flows through the selected memory cell. If current flows, it means that data "1" was stored, whereas if no current flows, it means that data "0" was stored.
As apparent from the description of the above operations, in a NAND cell type EEPROM, non-selected memory cells operate as transfer gates during the data read/write operation. For this reason, there is a limit of a threshold voltage of a memory cell written with data. For example, the proper range of the threshold value of a memory cell written with "0" should be from 0. 5 V to 3.5 V. This range is required to be narrower when considering a change of the threshold value with time after data write, variation of characteristic parameters of memory cells, and variation of power supply voltages.
However, it is difficult for a conventional data write method to make the range of the threshold value of a memory cell written with data 0 enter such an allowable range, because the conventional data write method writes data by using the same condition for all memory cells while using a fixed write potential and write time for all memory cells. More specifically, the characteristic of each memory cell changes with variation of manufacturing processes, sometimes resulting in a memory cell easy to be written and at other times resulting in a memory cell difficult to be written. Considering such a write characteristic difference, there has been proposed a data write method which controls the data write time for verifying the written data, in order to set the threshold value of each memory cell within a desired range.
With this method, however, data in a memory cell is required to be outputted from the memory device in order to check whether data has been written properly, posing a problem of a longer total write time.
For an erase verify operation, there is known a technique as disclosed in Japanese Patent Laid-Open Publication No. 3-259499, whereby outputs of a plurality of sense amplifiers are supplied to an AND gate, and the logical operation result is used in generating a collective erase verify signal. However, this circuit configuration can be used only for the NOR type erase verify operation, and it cannot be applied to the write verify operation. The reason for this is that the values of write data take "1" and "0" and the logical operation of the sense amplifier outputs cannot be used for a collective verify operation. For this reason, it becomes necessary for a data write operation to repetitively execute the write operation and verify read operation and sequentially output data of each memory cell, hindering the high speed data write operation.

Non-volatile semiconductor memory device and memory system using the same


Methods and apparatus for assigning bandwidth to a network based on two or more different service levels. In an exemplary embodiment, video on-demand (VOD) session requests within a service group of an HFC cable network are assigned bandwidth such that maximum opportunity is given to grant HD VOD request among SD VOD requests, while meeting the goal of minimizing service disruption by spreading the sessions over multiple QAM channels, and limiting the maximum number of active VOD sessions of any kind.

1. Field of Invention
The present invention relates generally to the field of network bandwidth allocation, and specifically in one aspect to maximizing the utilization of available bandwidth on the network to support video services with various bit-rates (such as on-demand video) over a content-based network such as a cable television network.
2. Description of Related Technology
Providing "on-demand" (OD) services, such as e.g., video on-demand or VOD, is well known in the prior art. In a typical configuration, the VOD service makes available to its users a selection of multiple video programs that they can choose from and watch over a network connection with minimum setup delay. At a high level, a VOD system consists of one or more VOD servers that pass and/or store the relevant content; one or more network connections that are used for program selection and program delivery; and customer premises equipment (CPE) to receive, decode and present the video on a display unit. The content is typically distributed to the CPE over a Hybrid Fiber Coaxial (HFC) network.
Depending on the type of content made available and rate structure for viewing, a particular VOD service could be called "subscription video-on-demand (SVOD)" that gives customers on-demand access to the content for a flat monthly fee, "free video-on-demand (FVOD)" that gives customers free on-demand access to some content, "movies on-demand" where VOD content consists of movies only, and so forth. Many of these services, although referred to by names different than VOD, still share many of the same basic attributes including storage, network and decoder technologies.
Just as different varieties of VOD service offerings have evolved over time, several different network architectures have also evolved for deploying these services. These architectures range from fully centralized (e.g., VOD servers at a central location) to fully distributed (e.g., multiple copies of content distributed on VOD servers very close to customer premises), as well as various other network architectures there between. Since most cable television networks today consist of optical fiber towards the "core" of the network which are connected to coaxial cable networks towards the "edge", VOD transmission network architectures also consist of a mixture of optical fiber and coaxial cable portions.
The CPE for VOD often consists of a digital cable set-top box (DSTB) that provides the functions of receiving cable signals by tuning to the appropriate RF channel, processing the received signal and outputting VOD signals for viewing on a display unit. Such a digital set-top box also typically hosts a VOD application that enables user interaction for navigation and selection of VOD menu.
While the architectural details of how video is transported in the core HFC network can be different for each VOD deployment, each generally will have a transition point where the video signals are modulated, upconverted to the appropriate RF channel and sent over the coaxial segment(s) of the network. Depending on the topology of the individual cable plant, this could be performed at a node, hub or a headend. The coaxial cable portion of the network is variously referred to as the "access network" or "edge network" or "last mile network."
In U.S. cable systems for example, downstream RF channels used for transmission of television programs are 6 MHz wide, and occupy a 6 MHz spectral slot between 54 MHz and 860 MHz. Deployments of VOD services have to share this spectrum with already established analog and digital cable television services. For this reason, the exact RF channel used for VOD service may differ from plant to plant. However, within a given cable plant, all homes that are electrically connected to the same cable feed running through a neighborhood will receive the same downstream signal. For the purpose of managing VOD services, these homes are grouped into logical groups typically called Service Groups. Homes belonging to the same Service Group receive their VOD service on the same set of RF channels.
VOD service is typically offered over a given number (e.g., 4) of RF channels from the available spectrum in cable. Thus, a VOD Service Group consists of homes receiving VOD signals over the same 4 RF channels. Reasons for this grouping include (i) that it lends itself to a desirable "symmetry of two" design of products (e.g. Scientific Atlanta's MQAM), and (ii) a simple mapping from incoming Asynchronous Serial Interface (ASI) payload rate of 213 Mbps to four QAM payload rates.
In most cable networks, VOD programs are transmitted using MPEG (e.g., MPEG-2) audio/video compression. Since cable signals are transmitted using Quadrature Amplitude Modulation (QAM) scheme, available payload bitrate for typical modulation rates (QAM-256) used on HFC systems is roughly 38 Mbps. In many VOD deployments, a typical rate of 3.75 Mbps is used to send one video program at resolution and quality equivalent to NTSC broadcast signals. In digital television terminology, this is called Standard Definition (SD) television resolution. Therefore, use of MPEG-2 and QAM modulation enables carriage of 10 SD sessions on one RF channel (10×3.75=37.5 Mbps<38 Mbps). Since a typical Service Group consists of 4 RF channels, 40 simultaneous SD VOD sessions can be accommodated within a Service Group. These numbers work out very well for many deployment scenarios, such as the following example. A typical "service area" neighborhood served by a coaxial cable drop from the cable network consists of 2000 homes, of which about two-thirds are cable subscribers, of which about one-third are digital cable subscribers, of which about 10% peak simultaneous use is expected. Hence, the bandwidth required to meet VOD requirements is 2000×(⅔)×(⅓)×0.1=approximately 40 peak VOD sessions—the exact number supported by a 4 QAM service group.
From the discussion above, the need for a function called Service Resource Manager (SRM) is evident. When a new VOD session request is made, the SRM receives that request, allocates bandwidth on a downstream QAM channel, and sends the information back to the CPE that made the request so that it can tune to the right RF channel and the VOD program therein. Since the SRM controls mapping of incoming VOD session requests to QAM channels within the Service Group, it is an appropriate place for a Cable Operator to enforce RF channel usage policy. In general, SRM should maximize availability of bandwidth to VOD sessions (by efficiently recycling bandwidth from expired sessions) and by ensuring some level of redundancy in case of equipment failure (e.g. a QAM modulator goes down).
More and more US households are beginning to purchase High Definition (HD) televisions (HDTV). By one estimate, by the end of 2004, over 12 million US households will have HDTV displays. To keep up with the trend, MSOs have begun offering HD television programs to cable customers and have recently started looking into deploying HD VOD services.
Entertainment-quality transmission of HD signals requires about four times as much bandwidth as SD. For an exemplary MPEG-2 Main Profile—High Level (MP@HL) video compression, each HD program requires around 15 Mbps bitrate. Although revenues from HD VOD service may not be four times the revenue from SD VOD service, the ability to offer HD VOD service is often critical to cable operators' strategy to be a leader in digital television service offerings.
Use of MPEG HD compression technology for initial deployment of HD VOD services is a logical choice, as HD VOD shares the same MPEG-2 transport layer technology. This approach allows reuse of most of the infrastructure deployed for SD VOD services. By using MPEG multiplexing techniques, SD and HD video streams can be simultaneously carried over the fiber side of the VOD network and multiplexed onto the same QAM channel in a service group. Since roughly 37.5 Mbps bandwidth is available on one QAM-256 carrier, cable operators can mix and match HD and SD VOD sessions using 3.75 Mbps per SD and 15 Mbps per HD VOD stream. For example, on a single QAM carrier, maximum 2 HD VOD sessions can be offered adding up to an aggregate 30 Mbps, with the other 7.5 Mbps being used by 2 SD sessions.
It should be recognized that under prevailing network and CPE design practices, the bandwidth required by a video stream cannot be spread over two QAM carriers. For example, when a new HD VOD session request is granted, all 15 Mbps of bandwidth must be made available on a single QAM carrier.
The role of the aforementioned SRM becomes even more important when managing a Service Group for simultaneous HD and SD VOD sessions. It has the additional task to map VOD sessions to QAM carriers such that it can ensure sufficient bandwidth block for HD VOD session on a QAM carrier in that Service Group. The method used for this mapping should at the same time be able to maximize the amount of bandwidth used without leaving bandwidth stranded on a QAM carrier. Since HD VOD takes much more bandwidth that SD video, during the introduction phase, a cable operator may wish to limit maximum number of sessions of either kind (SD or HD) allowed within a Service Group. Clearly, this number should be easily changeable (upward or downward) if business economics or other considerations demand it.
The foregoing discussion makes no assumptions regarding specific implementation details of the SRM. It will be recognized that the SRM function can be implemented at the edge or core of the network, in a VOD server, or elsewhere. Depending on where this function is implemented, it is variously referred to as NSG (Network Services Gateway) and SRM (Service Resource Manager).
For example, in a Scientific Atlanta network, the VOD server acts as the session resource manager and asks the Digital Network Control System (DNCS) for specific resources. The DNCS responds with a negative or positive response to the request and the VOD server implements the appropriate logic based on the response.
The need for a function that assigns from an available pool of resources to an incoming resource requests is known in the prior art. Various methods have been proposed to perform this function.
For example, U.S. Pat. No. 6,434,141 to Oz, et al. issued Aug. 13, 2002 and entitled "Communication management system and method" discloses a broadband multimedia system including a communication bus, a router, connected to the communication bus and further between a plurality of media sources and a plurality of network transmitters, a session manager, connected to communication bus, where the session manager provides routing instructions to the router, for directing data received from the media sources to the network transmitters for transmitting over a broadband network. No disclosure regarding assignment of bandwidth to VOD session requests is provided.
U.S. Pat. No. 6,201,901 to Imajima, et al. issued Apr. 3, 2001 and entitled "Video data distributing device by video on demand" discloses a requested title recognizing mechanism recognizes the title of a video requested by the subscriber. A VOD service state monitoring mechanism determines whether or not the broadcast of the video is to be provided in the FVOD or the NVOD service, and if there is any available channel for the broadcast. If the broadcast has not been switched from the FVOD service to the NVOD service, then a busy state monitoring mechanism checks the number of the current simultaneous subscribers for the video. If the number is equal to or larger than a threshold, then the busy state monitoring mechanism instructs an NVOD service providing mechanism to broadcast the requested video in the NVOD service. If the number is smaller than the threshold, then the busy state monitoring mechanism instructs an FVOD service providing mechanism to broadcast the requested video in the FVOD service. The patent does not, however, disclose any details regarding RF channel selection from available channels, or assignment of channels to the VOD request.
U.S. Pat. No. 6,169,728 to Perreault, et al. issued Jan. 2, 2001 and entitled "Apparatus and method for spectrum management in a multipoint communication system" discloses an apparatus and method for spectrum management in a multipoint communication system that controls upstream channel usage for secondary stations transmitting information to a primary station and downstream channel usage for secondary stations receiving information from a primary station. The apparatus includes a processor arrangement having a master controller and a plurality of processors, with the processor arrangement connected to a channel interface. The apparatus and method controls channel load balancing, channel congestion, and channel assignment in a multipoint communication system, and controls upstream channels independently from downstream channels. Factors and parameters utilized in such channel control and allocation include error parameters, channel noise parameters, transmit and receive loading factors, and congestion parameters. The patent also discloses implementation of "Least-Loaded" algorithm to assign bandwidth for next session request to the Least-Loaded carrier.
U.S. Pat. No. 6,092,178 to Jindal, et al issued Jul. 18, 2000 and entitled "System for responding to a resource request" discloses a method wherein a trigger is provided in association with a network naming service, such as DNS (Domain Name Service) that handles client requests for an application. The trigger comprises a set of executable instructions referenced by a resource record associated with an identifier of the application. In response to a client request concerning the application, the resource record is retrieved and the instructions are executed. In one implementation of a trigger, a DNS server provides load balancing among a plurality of servers within a network name space (e.g., domain or sub-domain) offering an application program (or replicated service) that is known by a virtual server name. A policy is selected for choosing a preferred server from the plurality of servers according to a specified status or operational characteristic of the application instances, such as the Least-Loaded instance of the application or the instance with the fastest response time. The policy is encapsulated within multiple levels of objects or modules distributed among the plurality of servers and the DNS server. The objects collect and assemble the servers' status and operational characteristics. The information collected by the objects is analyzed to select the server that best satisfies the selected policy. A client request for the application is received by the DNS server, which retrieves a resource record corresponding to the virtual server name. Within the record is the name of a trigger. The trigger is executed to select, or retrieve an identity of, a server to which the client request is to be directed.
U.S. Pat. No. 6,687,735 to Logston, et al. issued Feb. 3, 2004 and entitled "Method and apparatus for balancing distributed applications" discloses a method and apparatus for balancing distributed applications within a client/server network, such as a cable television network. In one aspect, a method of balancing the load of distributed application client portions (DACPs) across various server portions (DASPs) and server machines is disclosed. Statistics are maintained by one or more software processes with respect to the available resources of the servers and their loading; new process threads and/or distributed application server portions are allocated across the servers to maintain optimal system performance as client device loading increases or changes. In another aspect of the invention, an object-oriented distributed application software architecture employing both vertical and horizontal partitions and "mutable" (i.e., transportable) objects is disclosed. The mutable objects may reside on either the server or client portions of the distributed application while maintaining at least one network partition. A runtime environment adapted for the operation of the foregoing object-oriented distributed application, including a message protocol useful for interprocess communication, is also disclosed. Methods for downloading the DACP from the servers, and scaling the DACP at download based on client device configuration, are further disclosed.
The SeaChange MediaCluster Server device manufactured by SeaChange International Corporation comprises a group of fault-resilient VOD servers connected over a network, in effect acting as one server. See, e.g., U.S. Pat. No. 5,862,312 to Mann, et al. issued Jan. 19, 1999 and entitled "Loosely coupled mass storage computer cluster" and its progeny. This patent discloses a method and apparatus redundantly store data, in particular video data objects, in a distributed computer system having at least three processor systems, each processor system being connected in point to point two way channel interconnection with each other processor system. The data is stored in a redundant fashion both at the computer system level as well as the processor system level. Accordingly, the failure of a single processor does not adversely affect the integrity of the data. The computer system can also overlay a switching system connected in a ring fashion for providing a fault tolerance to the failure of a single connected processor system at the switch level.
The SeaChange apparatus further includes a session resource manager (SRM), and associated connection manager (CM) and streaming service (SS). The CM ostensibly allocates bandwidth, selecting the best network delivery path over which to stream data to the requesting entity. The SS "optimizes" bandwidth and provides some level of fail-over behavior, such that software component failure will not necessarily cause loss or tear-down of the underlying sessions. No functionality relating to the selective evaluation of allocation of bandwidth based on different service levels (e.g., SD or HD) is provided within this apparatus, however.
Description and Limitations of Least- and Most-Loaded Algorithms
Consider now the case of SD only VOD requests as shown in FIG. 1. The Service Group is assumed to have 4 QAM channels available. The first column 102 titled QAM1 corresponds to the first QAM carrier allocated to the VOD service. The column is divided into 10 rows, each representing 3.75 Mbps bandwidth available within the total capacity of the carrier. The corresponding aggregate bandwidth used up when each block is assigned to a VOD session is shown in the rightmost column 110 titled "QAM Bandwidth Mbps." From bottom to top, as the number of blocks assigned to VOD sessions increases, the total bandwidth used increases in steps of 3.75 Mbps from 3.75 Mbps (first session) to 37.5 (10th session). Similar bitrate blocks for three other QAM carriers belonging to the same service group are shown in the columns 104, 106 and 108 (QAM2, QAM3 and QAM4 respectively). The number in each box in FIG. 1 comprises a session index corresponding to a VOD session that is currently active.
In case of the Least-Loaded algorithm, every next VOD session request is granted bandwidth on the QAM that has the least bandwidth being used by VOD services (i.e. most free bandwidth available) with the search starting in a fixed sequence. For example, in FIG. 1, the following sequence is assumed for bandwidth search QAM1→QAM2→QAM3→QAM4. As shown in FIG. 1, first VOD request is assigned to QAM1, second request addressed to QAM2, third request is assigned to QAM3, fourth request is assigned to QAM4 and the 5th request is assigned by coming back to QAM1 and so on. Therefore, QAM session index number goes up from the bottom row left to right to top row, left to right in each row.
FIG. 2 is shows how the prior art Least-Loaded algorithm approach can leave HD VOD bandwidth stranded. In this example, a number (e.g., 28) consecutive SD VOD session requests are received, followed by a second number (e.g., 3) of HD VOD requests. The first twenty-eight SD VOD requests are allocated evenly on the four QAMs 202, 204, 206, 208 as shown in FIG. 2. The frequency slots remaining after the 28th session are assigned the remaining bandwidth 210. This illustrates that the total bandwidth available in this service groups is 45 Mbps (12 slots of 3.75 Mbps each). However, since the bandwidth available in each QAM is only 11.25 Mbps, which is below HD_BANDWIDTH, and since a HD VOD session cannot be allocated bandwidth split over multiple QAMs, the SRM will not be able to grant bandwidth to an incoming HD VOD request. The 45 Mbps available is therefore left "stranded" for the purpose of granting HD VOD sessions. This highlights the limitation of the Least-Loaded algorithm in that it lacks a systematic method of bandwidth allocation to ensure high availability of bandwidth in the Service Group to enable HD VOD sessions. A bandwidth allocation algorithm that can maximize usage of bandwidth usage should be able to make the remaining 45 Mbps bandwidth to three HD VOD sessions (at 15 Mbps per session.)
In the case where HD VOD session requests occur earlier, the Least-Loaded algorithm will eventually leave bandwidth stranded for HD VOD sessions. This is shown in the example of FIG. 3, the first two sessions 310, 312 are allocated bandwidth on QAM1 302 and QAM2 304, respectively. The next twenty-two sessions are SD, and are allocated bandwidth using Least-Loaded algorithm. The available bandwidth resources are now distributed as follows—7.5 Mbps each on QAM1 302 and QAM2 304, 11.25 Mbps on QAM3 306, and 11.25 Mbps on QAM4 308. It can be seen again that although total available bandwidth can support 3 HD VOD sessions, due to splitting the bandwidth among different QAMs, not even a single HD VOD session can be granted bandwidth at this time.
With reference to FIG. 4, the use of Most-Loaded algorithm is now explained. The leftmost column is QAM1 402, corresponding to the first QAM carrier belonging to the VOD Service Group. This column represents the total bandwidth available on this particular QAM carrier and divided into 10 rows, each representing 3.75 Mbps bandwidth available within the QAM carrier. The corresponding aggregate bandwidth used up when each block is assigned to a VOD session is shown in the right-hand column 410. From bottom to top, as the number of blocks assigned to VOD sessions increases, the total bandwidth used increases in steps of 3.75 Mbps from 3.75 Mbps (first session) to 37.5 (10th session). Similar bit-rate blocks for the three other QAM carriers 404, 406, 408 belonging to the same service group are shown (QAM2, QAM3 and QAM4, respectively).
When granting bandwidth using Most-Loaded algorithm, every next VOD session request is granted bandwidth on the QAM that has the least bandwidth available (but enough to accommodate the VOD session). In other words, the bandwidth is granted on the Most-Loaded QAM. FIG. 4 shows the case when the entire bandwidth available to the service group is filled by SD VOD sessions. The 1st session is granted bandwidth on QAM1 402. For the 2nd-10th session requests, since QAM1 402 is Most-Loaded, they are granted bandwidth on QAM1. The 11th session request is granted bandwidth on the next available QAM as QAM1 is fully occupied. Therefore, FIG. 4 shows the session index increasing from 1 to 40 from bottom-left slot, from bottom to top and then to the next QAM (QAM2 404, QAM3 406, and QAM4 408, respectively).
While prior art Most-Loaded algorithm does not exhibit the stranded bandwidth deficiency of the Least-Loaded algorithm previously described, it does have a salient drawback; specifically in the case of a QAM failure. Since the Most-Loaded algorithm unevenly loads up a QAM, a service outage can spread over multiple customers. Furthermore, when HD and SD VOD services are co-mingled, this assignment cannot effectively spread HD VOD sessions over multiple QAMs, thereby detracting from the failure performance that could be achieved if such spreading were utilized. This inadequacy is highlighted in FIGS. 5 and 6.
In FIG. 5, the VOD session request scenario of FIG. 1 above is again considered, yet this time by allocating session requests using the Most-Loaded algorithm. As shown, first twenty-eight SD VOD requests are stacked up by completely filling up QAM1 502, QAM2 504 and part of QAM3 506. The remaining bandwidth is available for two SD VOD sessions 530 on QAM3 506. As shown in FIG. 5, QAM4 508 has enough remaining bandwidth to grant to two HD VOD streams. However, both of these HD VOD streams (if granted) will occupy the same QAM channel, thereby increasing the risk of VOD session outage if that QAM fails.
In FIG. 6, the VOD session request scenario of FIG. 2 is again considered. Per the Most-Loaded algorithm, the first two HD VOD requests 640, 642 are assigned to QAM1 602. Similarly, session requests 25 and 28 are assigned to QAM4 608. It is evident from the session assignments that while QAM1 602 and QAM4 608 are double-loaded with two HD VOD sessions each, none is carried by QAM2 604 and QAM3 606.
While the prior art referenced above has generally identified the "SRM" function and the use of Least- and Most-Loaded algorithms for allocation, it fails to provide any apparatus or method that minimizes or mitigates the stranding of bandwidth in a QAM channel for an HD VOD session when both HD and SD session requests are present, or addresses the other disabilities highlighted above including increased risk of VOD session outage. Furthermore, the prior art SRMs and algorithms do not allow selective implementation of one or more business policies with the network, or even within a single service group.
Hence, there is a need for improved apparatus and methods that both increase the likelihood of having the capacity to provide HD bandwidth within a Service Group to an HD VOD session request, and minimize the chances of stranding bandwidth. Ideally, such apparatus and methods would be adapted to optimize load balancing across QAM channels, as well as maximize HD session support. Such apparatus and methods would further be configured to spread HD VOD sessions across different QAM channels so as to minimize impact of QAM failures on VOD sessions. Mechanisms to manage the maximum allowed number of HD and sessions within a VOD Service Group, and implement business rules and guarantee service levels for both SD and HD sessions, would also be provided.

Method and apparatus for network bandwidth allocation


An electrically powered hydraulic system for a working machine includes: an electric motor to power a working hydraulic pump. A flow of hydraulic fluid generated by the hydraulic pump is controlled by the operation rotational speed of the electric motor. An electronic control unit is configured to: when an operator input device is in a first operating range, maintain the electric motor at a constant rotational speed, and control a variation in flow of hydraulic fluid to the hydraulic function with an electronically controlled control valve, and when the operator input device is in a second operating range, control a variation in flow of hydraulic fluid by varying the electric motor rotational speed and by controlling the control valve, according to displacement of the operator input device.

An operator of a working machine such as a wheel loader may control the operation of hydraulic functions by displacing e.g. a joystick. The degree of displacement may be related to the operation speed of the hydraulic function. In order to provide different operation speeds, the hydraulic pressure provided by the hydraulics of the wheel loader is typically varied. For instance, a higher pressure may enable a higher operation speed.
EP2677180 describes an example hydraulic drive system for a working machine. The hydraulic drive system described in EP2677180 may perform normal operation and precision operation. The precision operation is performed at a smaller manipulation stroke than the normal operation. The hydraulic drive system disclosed by EP2677180 is provided with a variable displacement hydraulic pump to provide pressurized oil to a working element.
However, working machines such as wheel loaders generally generate relatively high intensities of noise during operation. The noise may be caused by the engines providing propulsion of the wheel loader but also by electric machines controlling the hydraulics system of the wheel loader. The hydraulic system may for example be arranged to control hydraulic functions such as movements of a boom or bucket attached to the wheel loader, a steering hydraulics, or other auxiliary functions.
The noise levels may cause an unsuitable working environment for the crew at the same site as the working machine as well as for the operator of the working machine.
Accordingly, there is a need for less noisy control of hydraulic functions for working machines.

Electrically powered hydraulic system and a method for controlling an electrically powered hydraulic system


A parameter indicative of the status of fluid flow is remotely monitored in a vessel, a natural graft, or a synthetic graft. One or more transducers are provided either in a wall of a synthetic graft or adjacent to a vessel or natural graft to monitor the parameter. A conformal array transducer or a tilted element is used to monitor fluid flow or velocity through the graft or vessel based on the effect of the fluid on ultrasonic waves produced by the transducers. The conformal array transducer comprises a plurality of elements that curve around the graft or vessel and are excited with an input signal provided by an implantable electronics circuit, producing ultrasonic waves that propagate into the fluid flowing within the graft or vessel. Transit time or Doppler measurements are made using an appropriate number of these transducer to determine either fluid flow or velocity. Various implantable electronic circuits are provided that enable a selected transducer to be driven and to receive an ultrasonic signal or a pressure signal indicative of the status of fluid flow monitored by the transducer. The implanted electronic circuit is connected to an implanted radio frequency (RF) coil. An external coil that is connected to a power supply and monitoring console is coupled to the implanted RF coil to convey power and receive data signals from the transducer that are indicative of the parameter being monitored.

A section of the vascular system in a patient's body that is diseased or defective can be surgically excised and replaced with a graft. A graft may comprise a portion of another vessel extracted from a different location in the patient's body or may be fabricated from an artificial, biocompatible material, such as GORTEX.TM. graft material, that will not be rejected by the patient's body. Although arterial grafts are often surgically implanted within the thorax of a patient, they may also be employed in other portions of the body. For example, an arteriovenous access graft or shunt is a specific type of graft employed to interconnect an artery and a vein and is typically disposed just below the skin in a patient's arm so that it is readily accessible for use in hemodialysis, i.e., to couple a patient suffering from renal failure to a dialysis machine.
Once a graft is surgically implanted, it is difficult to monitor its condition within a patient's body. Grafts often fail after a period of time due to the build up of blocking deposits, thromboses, or tissue growth within the internal lumen of the graft or at its junctions with the vessel in which it is inserted. It is estimated that the majority of arteriovenous access grafts used for hemodialysis will fail within about one year following their installation. In many cases, steps may be taken to restore full fluid flow through a graft that is becoming restricted--but only if the preventive measures are taken before the problem proceeds too far to be corrected without replacing the graft. Since it is generally not possible to determine the condition of flow through a graft without invasive surgery to inspect it, the procedure commonly adopted in the case of access grafts is to simply replace the graft each year, as a form of preventive maintenance. Clearly, it would be preferable to monitor the condition of a graft without resorting to invasive surgical procedures, so that the useful life of the graft can be extended and so that problems that may arise due to the failure of a graft can be avoided.
The best indicators of the condition of a graft are the velocity and volume of blood flowing through it. Fluid pressure at the distal and proximal ends of a graft (relative to the direction of blood flow) are a further indication of a graft's condition. As the lumen through a graft gradually becomes occluded with fatty buildup or other deposits, the pressure differential across the graft will increase, the velocity of blood in the lumen will decrease, and the flow of blood through the lumen will decrease. Each of these parameters thus serves as an indication of the condition of the graft and its viability to support necessary blood flow.
Ideally, it would be desirable to employ a graft--either natural or artificial--that includes means for monitoring the condition of fluid flow through the graft. The monitoring might occur continually or only periodically, upon demand. The means used for monitoring the condition of a graft should enable a physician to evaluate the parameters noted above at a remote location outside the patient's body, without resorting to an invasive procedure. Further, the monitoring means should at least periodically be supplied power from an external source, since it is unlikely that a battery could provide the power required by sensors and circuitry on the graft for an extended period of time.
Various techniques are known in the prior art for monitoring flow and velocity of a fluid inside a blood vessel, but in each case, the devices employed for this purpose are intended for relatively short-term use immediately following surgery and are not acceptable for the extended period for monitoring fluid flow, as noted above. For example, one type of volume flow measurement system described in U.S. Pat. No. 4,227,407 uses two piezoelectric ultrasonic transducers that are alternately activated to produce ultrasonic waves. The ultrasonic waves pass into a vein or artery and are modified by the flow of blood in the vessel interposed between the two transducers. When one transducer is actively transmitting an ultrasonic wave, the other transducer serves as a receiver of the wave. The two transducers are oriented at an acute angle relative to the longitudinal axis of the blood vessel, so that the ultrasonic sound wave propagating through the blood vessel has a component in the direction (or opposite to the direction) of blood flow through the vessel. In an alternative embodiment disclosed in this patent, the transducers are located on the same side of the blood vessel, spaced apart along its longitudinal axis, and a reflective plate is disposed on the opposite side of the vessel, intermediate the positions of the two transducers. An ultrasonic wave transmitted from either transducer passes through the blood vessel, is reflected from the reflective plate, and is received by the other transducer. The difference in the transit times for the sound waves transmitted from the two transducers (in both embodiments) is indicative of the flow through the blood vessel. If transducers used only extend over a small portion of the diameter of the vessel, the difference in transit time would be indicative of the velocity of blood flowing in the blood vessel. However, since the transducers shown in this prior art reference are sufficiently large so that the diameter of the blood vessel is fully encompassed by the sound waves the transducers emit, the transit time is indicative of the flow of blood flowing through the vessel, i.e., volumetric flow. The flow is thus determined without any consideration of the internal cross-sectional area of the blood vessel. While this prior art apparatus is useful for monitoring blood flow (or velocity) through a blood vessel that is surgically exposed, the transducers are too large to be implanted within a patient's body and are unsuitable to remain attached to or be incorporated into a graft to monitor the fluid flow status of the graft. Also, to provide a good acoustic path between the transducers and the adjacent surface of the vessel, it may well be necessary to apply the transducers against the surface of the vessel with sufficient force to distort the wall of the vessel into the notch in the apparatus that is formed adjacent the sloping face of each transducer. Such distortion of the vessel may adversely affect the accuracy of the measurements and is undesirable over an extended period of time.
Another prior art approach for determining the velocity and/or flow of blood in a vessel employs Doppler sensing using either a pulsed or continuous wave ultrasonic signal that is emitted at a defined angle relative to the longitudinal axis of the blood vessel. If only a single transducer is used, the angle must be accurately known, and any error in the angle must be corrected. However, if a transmitting transducer is disposed on one side of the blood vessel and a receiving transducer is disposed on the opposite side of the blood vessel, angled so that the ultrasonic beam reflected from the blood flowing through the vessel is directed to the receiving transducer, an angle correction is not required.
Examples of apparatus for Doppler monitoring of blood flow are disclosed in U.S. Pat. Nos. 5,289,821 and 5,588,436. In the first of these two patents, an ultrasonic transducer wire assembly is secured to a strip of biologically inert or absorbable material, which is wrapped around and in contact with a blood vessel to form a cuff, preferably disposed downstream from an anastomosis of the vessel, such as may be performed during microvascular surgery. The wire from the transducer exits the patient's body through a slit and is coupled to ultrasonic processing means that determine the velocity of blood flowing through the vessel by the Doppler processing of an ultrasonic wave that is transmitted by the transducer and received as a reflection from the blood in the vessel. After monitoring the velocity of blood flow for about three to seven days to determine if any thromboses has formed that would impede blood flow, the wire and transducer can be pulled from the strip and removed from the body through a small incision, leaving the strip behind. This device is not usable for an extended period of time (much beyond seven days), since the slit in the skin where the wires penetrate represents a pathway for infection. Further, the patent teaches that the invention is primarily intended for use on blood vessels close to the skin surface, such as those resulting from microvascular surgery on a patient's hand and thus would be unusable for monitoring the fluid flow through grafts deep within a patient's body.
In the second patent listed above, a Doppler scheme for determining blood velocity in a vessel is disclosed, wherein an elongate sheath is provided with a transducer head at its distal end. Two wires extend longitudinally through the sheath to a transducer that is mounted preferably at an angle of about 45.degree. relative to the longitudinal axis of the sheath. A biocompatible material such as epoxy encases both the transducer and the distal ends of the wires. This molded housing for the transducer has a concave surface that fixes the transducer relative to the blood vessel and provides a close fit to the surface of the blood vessel to provide a path for ultrasonic sound waves produced by the transducer to enter the blood vessel and for reflected waves to be detected by the transducer. A mesh band is wrapped around the transducer, and its ends are sutured together to hold the concave surface of the material in contact with the outer surface of the blood vessel. The band is made of VICRYL.TM. mesh or other absorbable/inert material. A thread having ends that run inside and along the longitudinal axis of the sheath secure the band to the distal end of the sheath. The proximal end of the sheath is preferably left extending through the patient's skin after the device is installed to monitor blood velocity through a vessel in contact with the concave surface of the material at the distal end of the probe. After the measurements are concluded (purportedly, after a maximum of up to 21 days), the thread is cut and pulled from its engagement with the band, so that the transducer, wires, and sheath can be withdrawn, leaving the band in place--possibly to be absorbed, depending on the material from which the band is fabricated.
Each of the Doppler devices discussed above is used to monitor the velocity of blood through a vessel, and to the extent that the cross-sectional area of the vessel is assumed or known, the devices enable flow to be estimated. However, neither prior art Doppler device is intended to monitor flow or velocity of blood for more than a few days. In addition, the elongate sheath used with the latter device is relatively bulky and not suitable for installation where available space around the vessel or graft is limited. Both devices put the patient at risk of infection, because at least the wires coupled to the transducer must extend from inside the patient's body through the skin, to an external monitoring system.
Another prior art technique for monitoring flow with a Doppler system that is more compact than the devices discussed above is based on a surface acoustic wave (SAW) transducer that couples a "leaky wave" into the wall of a blood vessel. The SAW transducer includes pairs of interdigital electrodes fabricated on a piezoelectric substrate that is relatively small, e.g., about 1.6 mm by 2.2 mm. This transducer is described in a paper entitled "Miniature Doppler Probe Using a Unidirectional SAW Transducer" by T. Matsunaka and S. Yamashita. To produce a unidirectional interdigital SAW transducer, the drive signal applied to half of the electrodes is phase shifted by 90.degree. relative to that applied to the other electrodes. The ultrasonic waves produced by the device propagate primarily in only one direction at an angle, .theta., thereby enabling the direction of fluid flow in a blood vessel to be determined. The wave that would normally be transmitted in the opposite direction at an angle, -.theta., is instead canceled by the interference between the interdigital electrodes driven with signals that are phase shifted relative to each other. This prior art reference states that the signal produced by a prototype SAW transducer had a maximum amplitude at a radiation angle of about 54.5.degree., with a beam width of about 2.5 times the actual electrode width (one mm) and suggests that the beam width might be reduced by modifying the electrode layout to achieve a "focusing effect."
Several advantages of the interdigital electrode SAW transducer design relative to the other devices available to measure flow and velocity of blood through a graft are apparent. The interdigital SAW transducer is substantially smaller in size than the prior art devices and requires less energy to produce ultrasonic waves. Further, the beam width is substantially wider than the physical size of the electrodes so that the apparatus can be made relatively small compared to the size of the beam that it produces. In addition, unlike the single transducer apparatus shown in the prior art first discussed above, which produce both forward and rearwardly directed waves that are affected by the velocity of blood in either direction but cannot determine the direction of flow, the unidirectional SAW transducer is able to monitor fluid velocity and determine the direction of the fluid flow.
The prior art does not disclose an interdigital transducer that monitors transit time. Instead, each of the interdigital transducers of the prior art SAW transducer discussed above produces a leaky SAW wave and employs the Doppler effect to determine the velocity of blood in a vessel. For monitoring velocity and flow through a graft, it would be preferable to employ a transducer that is compact, like an interdigital SAW transducer, but one that also has the ability to measure transit time and thus flow, generally independent of any considerations of velocity profile or cross-sectional area of the graft. This transducer should be implantable, preferably built into or secured to the graft when the graft is installed in a patient's body, supplied with electrical power from a source outside the patient's body, without using wires that penetrate the dermal layer, and should also permit monitoring of the flow, velocity, and pressure of a fluid without use of wires that pass through the skin. Currently, no compact prior art device is available that can remotely monitor flow and velocity parameters of an implanted graft for long periods (e.g., for months or even years) of time. Further, none of the prior art devices is designed to be wholly implanted, remotely monitored, and provided with power from a remote source outside the patient's body.

Ultrasonic sensors for monitoring the condition of a vascular graft