A sensor clip assembly for an optical blood monitoring system includes a circuit board with a microprocessor that is programmed with a ratiometric model to calculate hematocrit and/or oxygen saturation levels of a patient.

Patients with kidney failure or partial kidney failure typically undergo hemodialysis treatment in order to remove toxins and excess fluids from their blood. To do this, blood is taken from a patient through an intake needle or catheter that draws blood from a blood vessel located in a specifically accepted access location (for example, a shunt surgically placed in an arm, thigh, subclavian, etc.). The needle or catheter is connected to extracorporeal tubing that is fed to a peristaltic pump and then to a dialyzer which cleans the blood and removes excess water. The cleaned blood is then returned to the patient through additional extracorporeal tubing and another needle or catheter. Sometimes, a heparin drip is located in the hemodialysis loop to prevent the blood from coagulating particularly in the dialysis filter. By way of background, as the drawn blood passes through the dialyzer, it travels in straw-like tubes within the dialyzer that serve as semi-permeable passageways for the unclean blood. Fresh dialysate solution enters the dialyzer at its downstream end. The dialysate surrounds the straw-like tubes and flows through the dialyzer in the opposite direction of the blood flowing through the tubes. Fresh dialysate collects toxins passing through the straw-like tubes by diffusion and excess fluids in the blood by ultra filtration.
It is known in the art to use an optical blood monitoring system during hemodialysis, such as the CRIT-LINE® monitoring system which is sold by the assignee of this application. The CRIT-LINE® blood monitoring system uses optical techniques to non-invasively measure in real-time the hematocrit and oxygen saturation levels of blood flowing through a hemodialysis system. In the CRIT-LINE® system, a sterile, single-use blood chamber is attached in-line to the extracorporeal tubing normally on the arterial side of the dialyzer. The blood chamber provides a viewing point for optical sensors during the hemodialysis procedure. As described in more detail below under the heading Detailed Description of the Drawings, the blood chamber used in the current system comprises a molded body made of clear medical grade polycarbonate. The chamber body along with the tube set and dialyzer filter are replaced for each respective patient. The blood lines and blood chamber are replaced for each treatment though the personal filter for each patient is often cleaned and reused over several treatments. The blood chamber provides an internal blood flow cavity, a flat viewing region and two viewing lenses: one being integrally molded with the body of the polycarbonate blood chamber and the other being welded into place. The LED photo emitters and the photodetectors for the optical blood monitor are contained on a sensor clip assembly that is clipped into place on the blood chamber over the lenses. Multiple wavelengths of visible and infrared light are directed through the blood chamber and the patient's blood flowing therethrough, and the resulting intensity of each wavelength are detected. The preferred wavelengths to monitor hematocrit are: a) about 810 nm (e.g. 829 nm), which is substantially isobestic for red blood cells, and b) about 1300 nm, which is substantially isobestic for water. The preferred wavelengths to monitor oxygen saturation are: a) about 660 nm, and b) about 810 (e.g., 829 nm). The system includes a sensor clip assembly having an LED emitter for each wavelength (e.g. 660 nm, 810 nm, and 1300 nm) and also a silicon photodetector to detect the intensity of the 660 nm and 810 nm light and an indium gallium arsenide photodetector to detect the intensity of the 1300 nm light. Signals from the photodetectors representing the intensity of each wavelength (660 nm, 810 nm and 1300 nm) are transmitted from the sensor clip assembly to a stand-alone electronic controller.
A ratiometric technique implemented in the CRIT-LINE® controller, substantially as disclosed in U.S. Pat. No. 5,372,136 entitled "System and Method for Non-Invasive Hematocrit Monitoring", issued on Dec. 13, 1999 and assigned to the assignee of the present application, uses the information transmitted from the sensor clip assembly to calculate the patient's hematocrit and oxygen saturation levels in real-time. The hematocrit value, as is widely known in the art, is the percentage determined by dividing the volume of the red blood cells in a given whole blood sample by the overall volume of the blood sample. In a clinical setting, the actual percentage change in blood volume occurring during hemodialysis can be determined, in real-time, from the change in the measured hematocrit. Thus, an optical blood monitor, such as the CRIT-LINE® monitor, is able to non-invasively monitor not only the patient's hematocrit level but also the change in the patient's blood volume in real-time during a hemodialysis treatment session. The ability to monitor real-time change in blood volume facilitates safe, effective hemodialysis and the ability to manage body fluid retention.
The mathematical ratiometric model for determining the hematocrit value can be represented by the following equation:
                    HCT        =                  f                                [                                          ln                                                  (                                                            i                      810                                                              I                                              0                        -                        810                                                                              )                                                            ln                                                  (                                                            i                      1300                                                              I                                              0                        -                        1300                                                                              )                                                      ]                                              Eq        .                                                    (          1          )
where i810 is the infrared light intensity detected by a photodetector at 810 nm, i1300 is the infrared light intensity detected at 1300 nm and I0-810 and I0-1300 are constants representing the intensity incident on the blood accounting for losses through the blood chamber. The function ƒ[ ] is a mathematical function which has been determined based on experimental data to yield the hematocrit value. Preferably, the function ƒ[ ] in the above Eq. (1) is a relatively simply polynomial, e.g. a second polynomial. However, under some conditions, more complex fits such as a spline fit must be used.
The oxygen saturation level, or the oxygenated hemoglobin level, is determined using a ratiometric equation for red visible light at 660 nm and infrared light at 810 nm. The form of the preferred ratiometric model for determining oxygen saturation level is as follows:
                    SAT        =                  g                                [                                          ln                                                  (                                                            i                      660                                                              I                                              0                        -                        660                                                                              )                                                            ln                                                  (                                                            i                      810                                                              I                                              0                        -                        810                                                                              )                                                      ]                                              Eq        .                                                    (          2          )
where i660 is the light intensity of a photo receiver at 660 nm, i810 is the infrared intensity detected at 810 nm and I0-660 and I0-810 are constants representing the intensity incident on the blood accounting for losses through the blood chamber. The function g[ ] is a mathematical function determined based on experimental data to yield the oxygen saturation level, again preferably a second order polynomial, although it may be useful to use a pair of second order polynomials or spline fitting techniques depending on the hematocrit value.
In the prior art CRIT-LINE® system, the stand alone controller includes a display that provides real-time blood monitoring data for the patient undergoing hemodialysis. The controller contains a microprocessor that calculates the displayed data calculated by the ratiometric models discussed above. The stand alone electronic controller also controls the operation of the respective LED emitters and the detectors in order to multiplex the independent wavelength measurements. The stand-alone controller also contains signal processing and noise reduction hardware and software, as well as calibration software. Preferably, calibration is accomplished in the field by placing the sensor clip assembly onto a verification filter (made of layered plastic having known optical qualities) that is mounted to either the sensor cable or the casing of the controller. Calibration software within the controller verifies the calibration of the unit, or allows the user to field calibrate the unit to bring it back to factory calibration settings. In some instances, it may be necessary to return the unit to the factory for calibration.
Normally, as mentioned, the controller is provided as a stand alone unit. In some applications, however, it is desired to integrate the capabilities of the CRIT-LINE® into OEM hemodialysis equipment or the like. In these applications, one or more custom designed circuit boards containing the ratiometric models, the sensor control software, the signal processing hardware and software and the calibration software are placed in the OEM equipment to receive the signals from the sensor clip assembly.

Sensor clip assembly for an optical monitoring system


The present invention relates to a hand-held motorized device that is designed for sanding cylindrical objects. The invention comprises a left side and right side within which are a plurality of rollers, a motor, an on/off button, power supply, and sanding belt. A plurality of diameter knobs located on the exterior side of the housing enable a range of adjustment for various diameters. The sides can be disassembled to enable sanding belt replacement. The device has appealing uses comprising sanding down copper ends for soldering during plumbing installation.

A. Field of the Invention
The present invention relates to the field of belt sanders that are adapted for pipes, shafts, and cylindrical objects.
B. Prior Art
The Brandli et al. patent (U.S. Pat. No. 3,895,463) discloses an apparatus for buffing and polishing the entire outer surface of cylindrical tubing. However, this patent is not portable, and does not utilize a sanding belt that is draped over the exterior surface of a cylindrical object. This patent also uses pneumatic circuits and hydraulic motors to transmit power to the moving parts.
The Gardner patent (U.S. Pat. No. 5,038,525) discloses a pipe and polishing apparatus and method which comprises a cradle having an open section and a pair of pivotable doors covering the open sections and adapted to move between an open, pipe receiving position and a closed, pipe polishing position, the doors biased to remain in an open, pipe receiving position. This patent does not utilize a sanding belt that is draped over the exterior surface of a cylindrical object with a housing that contains an electrical motor, as opposed to a device that attaches to the chuck of a standard drill.
The Kadinger patent (U.S. Pat. No. 6,813,797) discloses an adjustable wire brush tool for cleaning either the inside or the outside end of a copper pipe. This device attaches to the chuck of a standard drill, and is not expandable to accommodate the various diameters of cylindrical objects.
The Zepp patent (U.S. Pat. No. 5,649,852) discloses a reciprocating and rotating sanding apparatus which has an expandable/adjustable sanding sleeve. However, this device requires connection to a drill press, and utilizes a rotary drum sanding device that does not drape over the exterior surface of a cylindrical object.
The Miner patent (U.S. Pat. No. 4,600,444) discloses a pipe exterior end cleaning device comprising a plurality of rotating brushes. However, this device is not portable nor does it drape a sanding belt over the exterior.
The Burrell patent (U.S. Pat. No. 4,869,026) discloses a belt sander which is powered by an electric motor and polishes metal or wood work pieces to a cylindrical or curved shape. However, this patent requires an exterior motor to provide the mechanical means to rotate the sanding belt.
The Helbig patent (U.S. Pat. No. 2,759,305) discloses a portable polishing and abrading machine that is not designed to drape a sanding belt over the exterior surface of a cylindrical object.
The Tomo et al. patent (U.S. Pat. No. Des. 229,616) illustrates a design for a portable polishing device that is not directed to sanding and does not drape a sanding belt over the exterior surface of a cylindrical object.


A polycarbonate dimethacrylate which is the condensation product of 2 parts of hydroxyalkylmethacrylate of the formula ##STR1## in which A is C.sub.1 -C.sub.6 alkylene, and 1 part of a bis(chloroformate) of the formula ##STR2## in which R is C.sub.2 -C.sub.5 alkylene having at least two carbon atoms in its principal chain and n is an integer from 1 to 4, is usable, admixed with a secondary monomer suitable for dental applications, such as BIS-GMA; PUDMA or the like, as an adhesive system for dental restorative materials. Particularly useful is the novel condensation product of 2-hydroxyethylmethacrylate and triethylene glycol bis(chloroformate).

In recent years, materials used for dental restorations have comprised principally methacrylate polymers. Typical of these polymeric substances are the acrylic resinous materials disclosed in U.S. Pat. No. 3,066,112, No. 3,179,623, No. 3,194,784, No. 3,751,399 and No. 3,926,906. Especially noteworthy is the compound which is the condensation product of bisphenol A and glycidyl methacrylate, 2,2'-bis [4-(3-methacryloxy-2-hydroxy propoxy)-phenyl]-propane (hereinafter abbreviated to "BIS-GMA"). Other methacrylate polymers, such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate, are also in general use as diluents. Polyurethanedimethacrylate is also used as a principal polymer in dental restorative materials of this type. Since BIS-GMA is highly viscous at room temperature, it is generally diluted with a monomer having a lower viscosity such as the aforementioned alkylene glycols or other compatible materials, including trimethylol propyl trimethacrylate, 1,6-hexanediol dimethacrylate, 1,3-butanediol dimethacrylate, and the like.
When these acrylic resinous materials were first developed, they were used unfilled for dental restorative purposes. However, because acrylic materials exhibit high coefficients of thermal expansion relative to the coefficient of thermal expansion for the tooth structure, these unfilled substances soon proved to be less than satisfactory. The disparity in thermal expansion, coupled with high shrinkage upon polymerization, resulted in poor marginal adaptability and ultimately led to secondary decay. Furthermore, the wear and abrasion characteristics and the overall physical, mechanical and optical properties of these unfilled acrylic resinous materials were quite poor. Thus, from the outset, composite dental restorative materials containing these methacrylate resins and fillers were developed. The fillers are generally inorganic filler materials based on silica, silicate glass, or quartz.
Over the years, there have been a number of refinements in the resin matrix component, in the filler component, and in the other additives--notably antioxidants, ultraviolet absorbers, polymerization initiators, polymerization accelerators, etc.--in dental restorative materials. There are now available materials which exhibit high diametral tensile strength, excellent optical properties and polishability, and low water absorption while, at the same time, complying with all of the requirements specified in ADA Specification No. 27 for direct filling resins. Particularly suitable restorative materials are the new compositions having improved inorganic filler materials such as those disclosed in my U.S. Pat. No. 4,547,531, disclosing self-curing 2-component compositions, and U.S. Pat. No. 4,544,359, disclosing visible light curable compositions.
All of these dental restorative materials are required to adhere permanently to the tooth structure. Generally, the tooth surface is treated with an acid such as 30-50 wt. % orthophosphoric acid, which etches the enamel tooth surface and exposes enamel rods in honeycomb prismatic structure thereon, whereby adhesion of the cured polymeric material is improved via micromechanical interlocking. In addition to this process of etching, the prior art teaches the use of various additives and improved monomeric mixtures which are designed to provide improved adhesion.
Although the acid etching technique by itself or coupled with modification of the resinous material to increase adhesive capability has been beneficial in effecting the bonding of dental restorative materials to tooth enamel, there has heretofore been no completely satisfactory process for adhering such restorative materials to dentin. Acid etching is not suitable for bonding dental restorative materials to dentin because the tubular structure of dentin provides passageways to the tooth pulp. The acid can cause great inflammation and pain to the patient and ultimately lead to pulpal necrosis. Furthermore, the high percentage of organic (protein) material in the dentin results in a lower degree of adhesion as compared with enamel.
There has recently been proposed a method for improving adhesion of dental composite materials to dentin surfaces which involves the successive application of (a) an acidic salt such as ferric oxalate or ferric citrate, (b) the adduct of N-(p-tolyl)-glycine and glycidyl methacrylate, the addition reaction product of N-phenylglycine and glycidyl methacrylate or N-phenylglycine itself, and (c) the addition reaction product of pyromellitic acid dianhydride and 2-hydroxyethylmethacrylate, the addition reaction product of 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 2-hydroxyethylmethacrylate, or 4-methacryloxyethyltrimellitic anhydride. This multi-step process has, however, not proved satisfactory.
In addition to much desired improvements in dentin bonding systems, it is also desirable to attain improved bonding to other dental surfaces, such as enamel, alloy-substrates and, particularly porcelain.
Despite recent advances in the development of filled dental restorative materials which have led to composites having higher resistance to abrasion, better handling characteristics, and more satisfactory visual appearance, there remains considerable room for improvement in these areas. Specifically desired are improved filled compositions for use as crown and bridge materials, denture-base materials, luting agents or cements and orthodontic appliance materials and sealants.
Accordingly, it is one primary object of this invention to provide improved dental adhesive materials for bonding to dentin, enamel, metallic alloys and porcelain.
It is another primary object of this invention to provide improved filled compositions for use as luting agents, denture-base materials, orthodontic materials and sealants, crown and bridge materials and other dental restorative materials.
It is a further object of this invention to provide a method for bonding a dental restorative material to a properly prepared tooth surface including dentin, enamel metallic alloys and porcelain.
Other objects include the provision of a dentin bonding system which employs a non-irritating pretreatment to yield a proper surface for application of the dental adhesive.
Still another object is to provide improved a dental adhesive which is particularly suitable for bonding to a properly prepared dentin surface. Other objects of this invention will become apparent from the following specification.


An interrupt control apparatus comprising an interrupt vector register for holding address information corresponding to interrupt resources of a first type which are managed by an operating system and interrupt resources of a second type which are not managed by the operating system. Regarding an interrupt generated by an interrupt resource of the first type, the interrupt control apparatus in the present invention launches a common interrupt entry function which is subject to a scheduling process common to the interrupt resources of the first type, based on the address information of the interrupt vector register. At the same time, with regard to an interrupt generated by an interrupt resource of the second type, the interrupt control apparatus in the present invention launches an extended interrupt entry function which is not subject to the aforementioned scheduling process, based on the address information held in the interrupt vector register.

(1) Field of the Invention
The present invention relates to an interrupt control apparatus for controlling interrupts generated from interrupt resources, as a part of an OS (Operating System) for controlling a computer system.
(2) Description of the Related Art
Generally, the interrupt control in a computer system processes interrupts from each of the interrupt resources by unified management in the OS.
FIG. 1 is a diagram showing the relation of the transition from the kernel space to the user process space of the OS when an interrupt is generated, in the existing computer system. As shown in the diagram, an interrupt transitions to a user process within a process space 601, from an interrupt processing unit for receiving interrupts and after schedule processing by the scheduler, in a kernel space 602.
FIG. 2 is a diagram showing the structure of the interrupt control apparatus in the existing computer system. The diagram includes peripheral devices as interrupt resources generating interrupts, an interrupt controller, a CPU, an OS, and an application process, shown in a hierarchical manner. FIG. 3 is an operation explanatory diagram showing the process flow in FIG. 2 by focusing on the register structure of each component element. The operations in FIG. 2 shall be explained more specifically, using FIG. 3.
An interrupt controller (INTC) 502 detects the generation of an interrupt from a variety of peripheral devices (I/O apparatus) 501a, 501b, and the like, and sets a flag of a cause number within the cause number register 502a, corresponding to the interrupt cause concerned. If such interrupt cause is not masked by software settings, the interrupt controller 502 notifies a CPU 503 of the interrupt generation.
The CPU 503 possesses interrupt vector registers 503a complying with interrupt levels. After receiving the interrupt notification from the interrupt controller 502, the CPU 503 reads an interrupt vector from the interrupt vector register to which the interrupt cause is assigned, and executes an interrupt entry function 505 managed by the OS. By executing such entry function 505, determination of the interrupt cause, transition to a user interrupt handler, and so on is carried out. At that time, a scheduler 506 carries out schedule adjustment among other interrupts and other processes. After schedule adjustment, the scheduler 506 launches the interrupt handler 507a, 507b, or the like corresponding to the interrupt cause, and the process corresponding to the interrupt request is carried out (or the corresponding process is called).
It is common in the existing interrupt control apparatus to carry out the series of interrupt control through the operation mentioned above.
Incidentally, the usual OS does not assume the case in which only specific interrupt resources are considered as being outside the management of the OS, and a particular mechanism is required for such. As a particular mechanism for such purpose, an implementation method using a plurality of OSs and an OS-independent interrupt management program is disclosed in official publication of Japanese Laid-Open Patent Application No. 2001-216172 (hereinafter referred to as Reference 1).
Reference 1 discloses a method for interrupt control using a method in which the interrupt resources managed by one of OSs is taken by the OS-independent interrupt management program and distributed to the other OSs, and a method in which the launch timing of respective interrupt handlers is determined according to the execution status of the OSs. According to this method for interrupt control, a generated external interrupt is processed once through the interrupt management program, and it is possible to distribute the interrupt processing among the plurality of OSs and carry out such interrupt processing in the distribution destination OS. Furthermore, even in the case where the interrupt processing is multiplexed among the plurality of OSs, exclusive control is possible by managing the interrupt status through the interrupt management program.
However, according to the existing interrupt control apparatus, in the case where only a particular interrupt resource is considered as being outside the management of the OS, the problem exists in which responsiveness, from the generation of the interrupt to the execution of the corresponding application, in other words, real-timeliness, cannot be guaranteed.
Specifically, the problems mentioned below exist in the case where specific interrupt resources for an OS are separated and managed independently by another program.
(1) In Reference 1, interrupt status management becomes a necessity for the interrupt management program as the interrupt management program reconciles the multiplexing among the OSs carrying out interrupt processing. For example, in Reference 1, the scheduler 506 would be equivalent to an interrupt management program which carries out more complicated schedule adjustments. In processing through a new implementation of such interrupt management program, a degree of real-timeliness is lost with the additional requirement of managing the interrupt status, in addition to the interrupt entry function implemented in the existing OS.
(2) Regardless of Reference 1, conventionally, there is no mechanism that positions an interrupt handler function of a user, corresponding to a particular interrupt cause, in a user process space instead of the address space (kernel space) of the OS, and carries out the transition to such positioned interrupt handler function without inhibiting interrupt responsiveness. In the process of transition from the kernel space 602 to the process space 601 shown in FIG. 1, the responsiveness of the scheduler is dependent on the performance of the OS. In a multi-purpose OS, there is no guarantee for the time taken up to the transition to the application, after an interrupt is generated. In other words, the absence of a guarantee for real-timeliness becomes an issue.
(3) The structure in Reference 1 is one which requires at least two or more OSs, as the interrupt resources for the CPU are divided for management by a plurality of OSs, and the case where interrupt resources are divided between one OS and the application program running on such OS is not assumed.
In consideration of the aforementioned issues, the present invention has as an objective, to provide in a multi-purpose OS, an interrupt control apparatus for interrupts from interrupt resources, which guarantees real-timeliness, a control method as well as a program thereof. In particular, the present invention has as an objective to provide an interrupt control apparatus for guaranteeing and realizing on a multi-purpose OS, real-timeliness commonly required in built-in devices, a control method as well as a program thereof.

Apparatus and method for interrupt control

Matsushita Electric Industrial Co., Ltd.


An input mechanism for a portable electronic device includes a rotational manipulation mechanism, such as a cap or shaft. The input mechanism also includes a sensor having first capacitive elements coupled to the manipulation mechanism, second capacitive elements, and a dielectric positioned between the first and second capacitive elements. Movement of the manipulation mechanism alters the positions of the first and second capacitive elements with respect to each other and is determinable based on capacitance changes resulting therefrom. In some implementations, the second capacitive elements may be part of an inner ring or partial ring nested at least partially within an outer ring or partial ring.

Electronic devices include a variety of different input and/or output devices for receiving input from and/or providing output to users. Examples of input and/or output devices include keyboards, touch screens, displays, joysticks, microphones, speakers, watch crowns, trackpads, track balls, and so on.
Some input devices include a moveable member and one or more sensors or other components that detect the movement of the moveable member. For example, keyboards may include a number of keycaps that can be pressed to activate one or more switches. Activating a switch may provide input to the electronic device.

Capacitive gap sensor ring for an input device


A mounting apparatus for aiding in mounting a plurality of long expansion cards in electrical devices includes a rack, and a fixing member. Each of the expansion cards defines an aperture in one end thereof. The rack includes a supporting shelf, a beam, and a fixing plate. The fixing member is slidably attached to the fixing plate of the rack and includes a plurality of hooks extending therefrom. The hooks movably engage in apertures to secure the expansion cards.

1. Field of the Invention
The present invention relates to mounting apparatuses for mounting a plurality of expansion cards in an electronic device, and particularly to an auxiliary mounting apparatus which can aid to securely mount a plurality of expansion cards with long dimensions in an electronic device.
2. Background of the Invention
In order to upgrade the operating capabilities of a personal computer, a plurality of expansion cards is operatively installed in the computer enclosure. Typical types of expansion cards include network cards, sound cards, graphics accelerator cards, multi-media cards and etc.
U.S. Pat. No. 4,745,524 discloses a mounting mechanism for mounting a plurality of expansion cards in a computer chassis. The mounting mechanism includes a pressing element, and a screw to secure a separate cover piece of a corresponding expansion card. However, the mounting mechanism only secures one end of the expansion cards to the computer chassis. If the expansion cards are long, such a mounting mechanism may not stably secure the expansion cards in the computer chassis.
What is needed is to provide a mounting apparatus which can aid to securely mount long expansion cards in electrical devices.

Auxiliary mounting apparatus for expansion cards

Bao-an District, Shenzhen, Guangdong Province

Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd.


A method for evaluating the spatial resolution of a volumetric medical imaging system comprises imaging an image phantom including a sphere surrounded by a uniform medium. The image phantom is imaged and the resulting volumetric data set is used to generate an edge response function in three dimensions. Differentiating the edge response function produces a plane spread function. The method simultaneously measures the spatial resolution in all directions, providing a bulk measurement resolution. Alternatively, the edge response function may be assembled in a manner so as to independently measure the axial and trans-axial resolution of the volumetric imaging system.

The evolution of mathematical concepts in tomographic reconstruction and technological advances in instrumentation, and computing in the late 1960s led to the development of x-ray computed tomography (CT). Single-slice, first generation CT scanners became available commercially in the early 1970s for clinical applications for diagnostic imaging of the head. These first generation CT scanners consisted of a pencil beam geometry and a single detector utilizing a translate and rotate acquisition geometry which required several minutes to produce a single cross-sectional image slice (tomogram) through the skull. The publication entitled "Computerized transverse axial scanning (tomography)" authored by Hounsfield, British Journal of Radiology, 1973 December; 46 (552): 1016-22 discloses such a first generation CT scanner.
The impact of CT scanning technology was significant and led to the rapid development of new systems which employed larger x-ray beams and more detectors in order to decrease scan time and increase the area of scan coverage. By the early 1980s, clinical CT scanners could acquire transverse (trans-axial), single cross-sectional images through any part of the human anatomy in a matter of seconds. By the early 1990s, clinical CT scanners combined bed patient motion in the axial direction with gantry rotation speeds in the order of one (1) second per revolution to generate so-called helical data sets. These CT scanners routinely generated stacks of two dimensional (2-D) image slices representing the three dimensional (3-D) volume of the anatomy being scanned. The discrete elements forming the 3-D volume are commonly referred to as voxels. The availability of advanced computing and visualization equipment allowed physicians and scientists to arbitrarily view image slice data through the scanned 3-D volume of tissue.
By the late 1990s, CT scanners were developed with multiple rows of detectors and larger x-ray beam coverage (extending several slices axially), which further decreased the scanning time for imaging large volumes of anatomy. In 2004, CT scanners generating sixty-four (64) slices per gantry rotation became commercially available. In 2005, CT scanners became available that acquire 3-D data sets with the so-called cone-beam geometry (divergent x-ray beam fully extending across the trans-axial direction and covering many slices axially) in a matter of seconds. The 3-D voxel data set generated by these CT scanners is typically reformatted and viewed using a number of display techniques, i.e. multi-planar reformatting, maximum/minimum intensity projection, and volume rendering.
In addition to CT scanning, other volume imaging modalities such as for example, magnetic resonance, ultrasound, and nuclear/PET imaging, have been developed that generate 3-D data sets.
Quantifying the spatial resolution, resolving power, or detail detectability of an imaging system has always been of significant interest and utility, particularly in medical imaging systems. Standard methods of assessing resolution include line-pair or spoked phantoms (test objects) which contain high contrast structures with varying spatial frequencies. These phantoms are 2-D in nature and typically, imaging system performance is evaluated through the visual inspection of phantom image data where the highest spatial frequency for which structures can be discriminated (resolved) indicates the limiting spatial resolution. Line-pair phantoms assess resolution in one dimension only and may be rotated and re-imaged to assess resolution in the axial and trans-axial directions.
In 1976, a method by which a continuous set of spatial frequencies could be examined simultaneously, to examine CT scanner spatial resolution performance was proposed and is described in the publication entitled "The line spread function and modulation transfer function of a computed tomographic scanner" authored by Judy, Medical Physics, 1976, July-August; 3(4): 233-6. The disclosed method involves imaging a high contrast slanted edge trans-axially. The image slice data provides the edge response function (ERF), which in turn provides the response of the CT scanner to a step function. Differentiating the ERF generates a point spread function (PSF) and thus, the response of the CT scanner to an impulse (delta) function. Since the impulse function contains all frequencies, this means that the response of the CT scanner to all spatial frequencies may be assessed, in one dimension, simultaneously, by imaging the slanted edge.
The 'slanting' of the edge in a 2-D image allows for over-sampling, thereby overcoming the limitations of discrete sampling inherent to digital data sets. The edge may be rotated in the scanning field of the CT scanner to measure the resolution in the 'left-right' and 'anterior-posterior' directions of trans-axial images. The edge may be rotated again to measure axial resolution.
Assessment of resolution in a CT scanner for quality control purposes has typically been done using a bar pattern phantom with a series of stacked plates aligned with the axis of the CT scanner. While quantitative modulated transfer function (MTF) measures of bar pattern data have been reported, most quantitative measures have been made with wires, thin plates, or the surface of a block. In all cases, the phantoms are aligned with the axis of the CT scanner and the data from a transverse slice is analyzed using traditional methods for assessing the MTF from a point spread function (PSF), line spread function (LSF), or edge spread function (ESF). For these methods, the two-dimensional image data is analyzed using traditional radiographic methods that relate the PSF, LSF, and ESF to the MTF.
The importance of resolution measurements is driven by the interdependent relationship between image quality (noise), resolution, and dose. A novel method for quantifying spatial resolution in a volume micro-CT scanner is described in the publication entitled "Resolving Power of 3D Microtomography Systems" authored by Seifert and Flynn, Medical Imaging 2002, Proceedings of SPIE Vol. 4682 (2002):407-413). The method involves imaging a sphere of uniform material composition immersed in a homogeneous media. The sphere represents a '3-D edge'. The sphere and surrounding media are imaged, and the voxel intensity for each voxel, in the resulting volume data set, is plotted as a function of distance from the center of the sphere. This plot represents the ERF in all directions and is referred to as the surface spread function (SSF). The surface spread function is differentiated to produce the equivalent of the PSF, which is subsequently Fourier transformed to produce the modulated transfer function (MTF) for the micro-CT scanner.
For modem multislice CT (MSCT) scanners, which routinely produce three dimensional volumetric data sets with nearly isotropic resolution, methods that can assess the MTF as a function of direction in three dimensions (3D) are needed.
It is therefore an object of the present invention to provide a novel method of evaluating the resolution of a volumetric imaging system and image phantom used during resolution evaluation.

Method of evaluating the resolution of a volumetric imaging system and image phantom used during the resolution evaluation


A fastening tool having plural power source ports that, when contemporaneously activated, deliver compressed air to a fastener driving assembly to drive a fastener into a workpiece.

1. Field of the Invention
The present invention relates, in general, to the field of fastening tools. In particular, the present invention relates to fastening tools having plural sources of power channeled through plural handles, and more particularly to a fastening tool for industrial applications such as the manufacture of pallets, used in the shipping and handling of commercial of goods.
Pallets are constructed by assembling wood boards in the form of a frame having at least one, and normally two, supporting surfaces or platforms which are spaced by beams or runners which extend perpendicular to the supporting surfaces in spaced relation. In the manufacture of wooden pallets, the boards which form the supporting surfaces at both the top and bottom of the pallet are spaced at desired intervals along such surface and fastened to the beams or runners to form a rigid frame assembly. In addition to wood, pallets can be made from plastic, metal, and paper. Fastening tools are used to join boards together to form a pallet.
2. Description of the Related Art
Pneumatic fastening tool development has been directed toward designing fastening tools that are for use with one hand. Therefore, a movement in the pneumatic fastening tool field is to design new tools that are smaller and lighter in weight, yet still maintain the driving power of traditional and older pneumatic fastening tools. The design of lightweight pneumatic fastening tools for single-handed fastening is in response to tool users' need to position, with their free hand, workpieces to be fastened together.
In industrial environments, however, such as the pallet fabrication and repair industry, the user does not need to use their free hand to position workpieces to be fastened together, because workpieces are arranged through automation. As a result, the free hand is idle and at risk of injury or being involved in a workplace accident, as the free hand is not required for use in the industrial fabrication operation. Adding a second handle that provides a control mechanism for operation of the tool requires both hands to be on the tool, thereby reducing the risk of injury in an industrial workplace accident.
A second handle has been used on existing large or heavy hand-held pneumatic fastening tools so that both hands of the user can be used to balance the tool and position the tool more easily. However, as a second handle is not required for actual operation, these existing tools can be operated with a single hand. A second handle for balancing the tool that is not required for operating the tool, is generally referred to as a "dead" handle. Dead handles do not require that both hands be on the tool for operation of the tool.
Taiwan Patent Application No. 1352652, which is herein incorporated by reference in its entirety, discloses a tool 1000 having a first handle 1002 and a second 1004 that controls air supply into the fastening tool for operation of the tool. Such an active second handle 1004 is generally referred to as a "live" handle. The second handle 1004, as shown in FIG. 1, is a live handle located in the air supply path of the tool and includes a manually operated pneumatic valve controlled by a lever 1006 that renders the tool non-operational unless the second handle 1004 is grasped and the lever 1006 is pulled to activate the valve. The valve opens to supply compressed air into the tool. FIG. 2 is a functional schematic of the tool operation with the second handle 1004. The schematic shows how the tool activation is dependent upon both of the users' hands controlling two separate valves in addition to engaging the work contact element with the workpiece to operate the tool 1000. The two separate valves are a first handle trigger valve 1008 and a second handle trigger valve 1010.
One of the challenges of having an auxiliary handle is providing a sufficient supply of compressed air to the tool for operation with varying air system environments and fastening rates. The live handle must be designed so that the force to activate the valve is within a range that is not fatiguing to the user. Also, the live handle body must be ergonomically designed to reduce grasp fatigue. The above design considerations result in an upper limit to the air flow rate through the auxiliary handle which can lead to functional problems when a higher air flow rate is required.
The functional schematic of FIG. 2 shows the external connections between elements of the fastener assembly shown in FIG. 1. When the live handle is released, the volume of compressed air in the tool reservoir 1012 is completely exhausted. As a result, the tool 1000 has a higher air consumption necessitating a higher capacity air compressor.

Fastening tool with dual pneumatic handles


A fluid flow regulator of a fluid delivery system that can adjust a flow rate of a liquid drug dispensed from a liquid drug container to a user is provided. The fluid flow regulator can be coupled to an end of the liquid drug container. The fluid flow regulator can include a compliance plate and a flow channel selector plate having a fluid flow channel. The flow channel selector plate can be rotated relative to the compliance plate and the liquid drug container to expose a selected portion of the fluid flow channel to openings in the compliance plate that are in fluid communication with the liquid drug stored in the liquid drug container. The selected portion of the fluid flow channel can correspond to a corresponding flow resistance of the liquid drug through the fluid flow channel, thereby regulating the flow of the liquid drug to the user.

Many conventional drug delivery systems are designed to be wearable and to deliver a drug slowly to the patient over time. Some conventional wearable drug delivery systems use spring arrangements to force a plunger to move within a liquid drug cartridge, expelling liquid drug from the cartridge into a needle that provides the drug to a patient. One issue with such spring-powered devices is that the force applied to the plunger generally decays as the spring expands. This spring force decay can cause variations in the flow rate at which the liquid drug is expelled from the liquid drug container, resulting in uneven delivery of drug to the user.
A need therefore exists for a drug delivery device that has improved flow control characteristics.

Fluid flow regulation arrangements for drug delivery devices


A satellite-based, world-wide cellular messaging system (5) transmits paging messages to pagers (2) via multiple beams. A pager (2) monitors multiple beams, recording the schedules for each beam, and by combining the schedules for multiple beams, ultimately determines which frames in the message groups to monitor for messages. Pager (2), which conserves battery resources by entering into a sleep mode, synchronizes quickly to its message block when it awakes.

Simplex data communication systems, also known as one-way or passive systems, are employed in connection with paging. Generally speaking, one or more transmitters broadcast data communications. The communications include data which identify specific pagers. A population of pagers continually receive the broadcast communications. When one of the population of pagers identifies a communication directed to it, it alerts a subscriber to the incoming communication and often displays a numeric or alpha-numeric message carried by the communication. Due to the simplex nature of such systems, the system does not know when a pager fails to receive a communication directed to it. On the other hand, these simplex systems have many desirable features. Due to the absence of a transmitter and signal transmission capabilities in the pager, a small, low-power, light-weight, readily portable, and inexpensive unit results.
Conventional paging systems, such as terrestrial based systems, are capable of providing coverage only near commercially viable areas. This concentrated and local coverage restricts reliable delivery of messages outside of these areas.
Satellite communication systems provide a reliable propagation path for non-metropolitan users of paging services. Satellites receive transmitted information and convey it back to pagers on Earth. Transmission of paging information from geosynchronous orbit requires substantial power and a broadbeam transmission which inherently has limited capacity as spectrum is not generally partitioned and reused.
Lower Earth orbiting constellations may partition and reuse communication spectrum as is done with terrestrial cellular duplex communications. Channelized or cellular satellite communication systems may project a plurality of beams upon the Earth. Since propagation boundaries and partitions are not conspicuous, an orbiting satellite may expose a pager to the propagation of multiple cells or beams.
For reliable reception of transmitted messages, a pager would be required to monitor multiple beams from a satellite in order to provide a reasonable assurance that any paged data transmitted to a pager was properly received. Each needless monitoring of an empty paging beam consumes power available to a pager and shortens the life-expectancy of a pager's batteries.
Therefore, there is a substantial need for an improved messaging unit capable of extending the operational life of a pager power source.
There is also a substantial need for encoding and presenting information to a pager for use in evaluating which beams to monitor for an increased probability of paging data.

Paging system employing delivery schedule combining and method of operation thereof


The present invention relates to the field of information security. Disclosed is an intelligent card secure communication method, capable of preventing the communication data from being monitored or intercepted. The method of the present invention provides a card with a definitely secure communication mechanism, initiates a session for the two communication parties to authenticate each other, and to check the identification legitimacy of the other party and the integrity of communication data, and provides a security constraint for subsequent communication, thus improving communication security.

With rapid development of communication technology, information network is widely applied, and crimes of computer and network come up constantly. People protect the data of information network by using identity identification and encryption technology and smart card products are widely used as identify tools for user identity identification. Secure and effective using of smart card can implement encryption and decryption process in real time for data transferred in the network, so as to guarantee that the user can enjoy service provided by the information network with security, speediness and convenience.
For the security related to the information security communication field, technology of the present is not perfect and cannot avoid problem of communication data being monitored or intercepted.

Intelligent card secure communication method


Disclosed is a safety device for a power brush of a vacuum cleaner which has a simple structure and can automatically cut off an electric source supplied to the driving motor of the power brush. A cylindrical air duct is vertically provided on the brush. The air duct is attached to the body of the cleaner. A negative pressure generated by a sucking force generated by the rotation of the driving motor in the body of the cleaner acts on the air duct. An air valve moves inward by the negative pressure in the air duct. At a first end of a rod, the air valve is mounted and at a second end facing the first end, a spring for applying a rotating force to move the air valve to an external direction, is provided. The rod is movably supported by a moving shaft provided near the outer periphery of the air duct. A switch is provided at the second end side of the rod having the spring. The switch is off to cut off the electric source applied to the driving motor of the power brush to prevent the rotation of a rotating roller when the air valve moves to the external direction by the action of the spring. Accordingly, when a user does not use the vacuum cleaner, various safety accidents induced by the rotating force of the power brush can be prevented.

1. Field of the Invention
The present invention relates to a safety device for a brush of a vacuum cleaner and more particularly, to a safety device for a brush of a vacuum cleaner, which can prevent a safety accident induced by the power brush of the vacuum cleaner
2. Description of the Prior Art
A vacuum cleaner is a device for absorbing external dust or other foreign substances through a strong sucking force generated by the driving of a motor provided in the body of the vacuum cleaner. The sucked dust or the foreign substances are captured by a dust collecting envelope installed in a dust collecting compartment and cleaned air is exhausted out through a driving compartment.
Generally, vacuum cleaners are classified into canister-type vacuum cleaners and upright-type vacuum cleaners. A canister-type vacuum cleaner includes a body mounted on wheels and a hose assembly for sucking dust or other foreign substances into the body. A suction generating device such as a suction fan, a motor for driving the suction generating device, and a disposable dust container for filtering dust or other foreign substances from air sucked by the vacuum cleaner, are positioned in the body.
An upright-type vacuum cleaner has a constitution which is similar to that of the canister-type vacuum cleaner. However, the upright-type vacuum cleaner differs in that it vacuums a surface directly beneath its body, so a hose assembly is not required.
These days, the canister-type vacuum cleaner is more frequently used than the upright-type vacuum cleaner.
FIG. 1 illustrates a canister-type vacuum cleaner 100. Vacuum cleaner 100 includes a floor cleaning unit 110, a canister unit 120 and a hose assembly 130 extended between floor cleaning unit 110 and canister unit 120.
Floor cleaning unit 110 includes a main brush (not shown) or a suction nozzle (not shown), and the like. Floor cleaning unit 110 is detachably connected to hose assembly 130. Hose assembly 130 comprises a rigid wand 132 and a flexible hose 134. Hose assembly 130 is pneumatically connected to a dust collecting compartment (not shown) of canister unit 120 through a suction hose connector 136.
Canister unit 120 mainly includes a hood 122, a cover 124 and a body 126. Hood 122 encloses the dust collecting compartment and is pivotally installed onto body 126 so that the dust collecting compartment can be opened and closed. Hood 122 is provided with an inlet opening 127 formed through hood 122 for receiving hose assembly 130. Hood 122 also is provided with a transparent window 128 for notifying the user of the dust collecting state. Cover 124 encloses a motor compartment (not shown) where an electric motor and a suction fan driven by the electric motor are positioned.
In the vacuum cleaner having the above-mentioned constitution, a strong sucking force is generated by the rotation of the motor installed at the driving compartment in the body during the use of the vacuum cleaner. The dust sucked into the floor cleaning unit (brush head) by the sucking force is collected in the dust envelope detachably installed in the dust collecting compartment and the filtered air is exhausted out through the driving compartment.
Recently, a power brush which is provided with a motor in a cleaning unit and rotates a brush roller, is developed and applied to the vacuum cleaner for increasing the sucking efficiency of the vacuum cleaner on the dust. In the power brush, when an electric source is applied and the power is on state, the driving motor continues its driving and the brush roller always rotates. Only when an electric switch is off, the electric source supplied to the driving motor is cut off and the driving of the motor is stopped.
FIG. 2 is a schematic perspective view for showing the power brush for the conventional vacuum cleaner. As illustrated in FIG. 2, the power brush is provided with a rotating roller 205 which rotates by the rotation of motor 240 and a moving roller 218 positioned at the front portion of the brush in a brush body 201. Rotating roller 205 rotates by motor 240 during the cleaning using the vacuum cleaner to increase the dust sucking efficiency of the vacuum cleaner. In the power brush, the cleaning efficiency can be increased through the rotation of rotating roller 205 during the cleaning. However, the rotation of rotating roller 205 when the user does not cleaning, is unnecessary. Moreover, this rotation becomes a factor of safety accidents. Accordingly, the rotation of rotating roller 205 should be stopped when the vacuum cleaner is not used.
Therefore, in the vacuum cleaner having the power brush, a safety device for the power brush of the vacuum cleaner, which stops the rotation of rotating roller 205 when the vacuum cleaner is not contemporarily used to prevent safety accidents, has been reported. FIG. 3 is a schematic perspective view for showing a safety device for the power brush of the conventional vacuum cleaner.
A safety device 250 illustrated in FIG. 3 includes a pressing member 212 which is provided at one front side of brush body 201. Pressing member 212 is rotatably supported at one front side of brush body 201, by rotating shafts 213a and 213b which are formed at both rear sides of pressing member 212. At the first front side of pressing member 212, a pair of front protrusive portions 212b protruded downward by constant angle with an angle of inclination, are provided. And at the upper portion of the second side facing the first side where front protrusive portions 212b are formed, a cam 212a is formed. At the front end portion of front protrusive portions 212b, joining holes 214 are formed. Into joining holes 214, a rotating shaft 219 of moving roller 218 is inserted.
An elastic piece 217 of a switch 220 is brought into contact with the upper surface of cam 212a. At the front upper portion of pressing member 212, a protrusive boss 215 is formed. At protrusive boss 215, a compressive spring 216 is inserted to provide an electric source to brush body 201 and to impart a rotating force to pressing member 212 to the direction A.
Moving roller 218 provided at front protrusive portion 212b of pressing member 212 facilitates the movement of brush body 201.
When the user uses the vacuum cleaner, moving roller 218 contacts the bottom and pressing member 212 rotates to the reverse direction of the arrow A from the initial state. Accordingly, spring 216 is compressed and cam 212a rotates simultaneously to press elastic piece 217. Then, the applying state of the electric current is kept and the electric current is supplied to the motor.
Next, when the user lifts brush body 201, moving roller 218 is separated from the bottom. At this time, pressing member 212 is pressed downward by spring 216 and rotates to the direction of arrow A. Then, cam 212a rotates and elastic piece 217 of switch 220 moves downward along the contacting surface of cam 212a to transform into an off state. Accordingly, the electric current supplied to the driving motor of the power brush is cut off.
In the safety device for the power brush of the conventional vacuum cleaner, the brush should be turned over when assembling the moving roller and the switch. Therefore, the assembling process is very difficult and complicated. And the manufacturing cost is increased.

Safety device for a brush of a vacuum cleaner


A document management system is adapted to operate with a process management system for recording and viewing metadata of a document. The document metadata is used to record resources referenced while the content of the document is developed. The resources are recorded in the document metadata to identify relationships between the resources and the content of the document. The document content includes links that reference the document metadata stored on a remote server. The resources recorded in the document metadata and the content of the document are simultaneously displayed on a user interface of the document management system to provide context for understanding document history. By storing document metadata and document content separately, the metadata of the document remains consistent even when multiple copies of the document are distributed over a network.

1. Field of the Invention
The present invention relates generally to a document management system, and more particularly, to a document management system for recording, tracking and viewing documents referenced while developing the content of documents in for example a process management system.
2. Description of Related Art
Process management systems, which include workflow management systems, have become a widely deployed form of technology for supporting collaborative work. An important characteristic of process management systems is their ability to increase productivity by automating the flow of business processes. Productivity is increased by efficiently structuring process descriptions (i.e., routing paths). of documents from person to person or group to group so that information is provided to the right person at the right time. More specifically, the function of process management systems is to provide specific sets of information, such as documents, to a series of persons, groups, or other entities such as computers, in a given sequence so that the various persons, groups, or other entities can, for instance, approve, modify, or otherwise process the information according to a predefined process description or work process.
An example of a workflow management system is InConcert(trademark) (which is sold by InConcert Inc.). InConcert(trademark) allows organizations to model, execute, monitor, and dynamically control business processes that involve multiple human participants and multiple software systems. More specifically, InConcert(trademark) captures information about each process: its owner, task sequence, necessary documents, applications, and the names of users responsible for task execution. Also, InConcert(trademark) automatically prompts and tracks all tasks in the workflow process, actively locating the specific documents and software tools required for each step of a project and delivering them at the right time to those who need them. By automatically tracking all tasks and processes, InConcert(trademark) provides complete and timely status on those activities.
Process descriptions (i.e., process definitions) are used in process management systems to describe the flow of work and organizational responsibility in the performance of organizational processes (i.e., a process management system""s representation of the work process). That is, process descriptions are used to coordinate activities of different persons, groups, or other entities that are distributed in time and space so that they operate together more efficiently. Completing each task in the process description may require both knowledge and document intensive activities that are dependent on earlier completed tasks.
An implicit assumption behind the division of a process into a number of different tasks is that the accomplishment of these tasks is independent as long as the correct sequence is maintained. Assuming that the tasks defining a process description can be performed independently of each other leads to a decontextualization of activity. That is, decontextualization of activity causes individuals"" to lose their ability to manage the overall progress of work rather than the specifics of each individual task. In addition, decontextualization of activity leads to homogenization of the process execution (i.e., an assumption that the process is performed in just the same way every time). To solve these problems, tasks in the process description require that informed judgments be made about work carried out elsewhere in the process description. In other words, the work product (i.e., task documents) created by someone carrying out a task must be intelligible to those carrying out other tasks in the process description.
One means to make the work product intelligible is to record and reveal information about the activities surrounding the creation of the work product; that is, any ancillary documents used, materials consumed, people consulted, etc., in the course of carrying out the task. These elements contribute to the history of the working process, and so can help to make clear the actual activity involved in carrying out a task. Understanding the context in which a document is developed and used requires access to information about previous documentrelated activities. Accordingly, the history of a working process description provides those operating in a collaborative setting with the ability to view a document in the context that individuals formed about previous activities on the document.
Accordingly, it would be advantageous to provide a workflow system in which process description can be used as an index into the history of the creation of a task document. It would be further advantageous to provide a document management system that permits a user who is working on a particular task to view work product activity of other tasks from the vantage point of another point in the process description. Advantageously, such a workflow system presents completed work product of a particular task in an intelligible form to others either executing or reviewing completed tasks in the process description.
In accordance with the invention, there is provided a method and apparatus therefor, for using process descriptions within a process management system, such as workflow, to structure and retrieve information about the ways in which documents were created, modified and used in the context of particular activities within the process. The process management system creates, modifies and uses the process descriptions to both manage ongoing tasks as well as historical information concerning pending tasks defining the process description. Advantageously, users of the process management system are provided with means for understanding the context in which the past tasks in the process description were carried out, thereby providing insight into the current task. In effect, each completed task is associated with a perspective that relates task activity to the current task being performed.
In accordance with one aspect of the invention, a document management system provides means for recording and viewing activity of document use in for example the process management system. The document management system includes a user interface for receiving commands from an operator of the document management system. Also forming part of the document management system is a first memory, a second memory, and a processor. The first memory records content of a document developed at said user interface. The second memory records metadata of the document, which specifies resources referenced while the content of document is developed. The processor accesses the metadata of the document to identify relationships between the resources specified in the metadata and the content of the document. The resources identified in the metadata of the document provide context for understanding the document""s history. In effect, the metadata of the document, which includes information relating to the creation, modification and use of other documents or objects of interest, provides a history tracking mechanism for the document.
In accordance with another aspect of the invention, the document management system distributes document content so that the metadata associated with that content is not re-instantiated with each copy distributed over, for example, a network. By distributing document content with a global reference to the metadata of the document, the document is given a global existence. Advantageously, by passing metadata of a document using a global reference, the document""s metadata can be processed independent of a document""s format. Furthermore, passing metadata of a document using a global reference advantageously enables the creator of the document content to retain control over the metadata of the document, thereby minimizing volatility of document metadata.

Document management system for recording and viewing the history of document use


A differential amplifier circuit includes a differential input circuit which receives first and second input signals. The differential input circuit amplifies a potential difference between the input signals and outputs first and second voltage signals at first and second output terminals representing the amplified potential difference. A first output transistor is connected between a high potential power supply and a third output terminal of the differential input circuit. The first output transistor pulls up the potential at the third output terminal. A second output transistor is connected between the third output terminal and a low potential power supply for pulling down the potential at the third output terminal. A gate voltage controller is connected to the first and second output terminals and receives the first and second voltage signals and controls voltages applied to each of the gate terminals of the first and second output transistors to control the currents flowing to them.

Referring to FIG. 1, a conventional comparator circuit 10 formed by MOS transistors is shown. In the comparator circuit 10 shown, when an input signal Vin1 is at a higher level than an input signal Vin2, a drain current passing through a transistor Tr3 decreases to reduce the potential at a node N1 (or a gate of a transistor Tr7) substantially to the ground GND level. As a consequence, the transistor Tr7 is turned off, delivering an output signal Vout of an H level at an output terminal To.
On the other hand, when the input signal Vin1 is at a lower level than the input signal Vin2, the drain current passing through the transistor Tr3 increases to raise the potential at the node N1 (or the gate of the transistor Tr7). Consequently, the transistor Tr7 is turned on, passing the drain current of the transistor Tr7 through a resistor R and delivering the output signal Vout of an L level, which is substantially equal to the ground GND level, to the output terminal To.
In this manner, the comparator circuit 10 operates to deliver an output of either H level or L level in accordance with a result of comparison between the both signals Vin1, Vin2.
An op amp circuit is formed by feeding back the output signal Vout as the input signal Vin2. In this instance, the op amp circuit operates to bring the voltage levels of both signals Vin1, Vin2 substantially into coincidence with each other.
More specifically, P-channel MOS transistors Tr1 and Tr2 each have a source connected to a power supply Vcc (high potential bus) and a gate connected to the drain of the transistor Tr1. The gates of both of the transistors Tr1 and Tr2 are connected together. A current source 1 is connected to the drain of the transistor Tr1. The transistors Tr1 and Tr2 form a current mirror circuit. The transistor Tr2 operates as a constant current source, which passes a drain current equal to the current flow through the current source 1.
The drain of the transistor Tr2 is connected to sources of each of the P-channel MOS transistors Tr3 and Tr4. The transistor Tr3 has a drain connected to the drain of an N-channel MOS transistor Tr5. A source of the transistor Tr5 is connected to the ground GND (or low potential bus). A junction between the transistor Tr3 and the transistor Tr5 defines the node N1.
The transistor Tr4 has a drain connected to the drain of an N-channel MOS transistor Tr6 and to the gates of the transistors Tr5 and Tr6. The transistor Tr6 has a source connected to the ground GND. The gates of both of the transistors Tr5 and Tr6 are connected together.
The input signals Vin1, Vin2 are input to the gates of the transistors Tr3 and Tr4, respectively. The transistors Tr3 to Tr6 form a differential input circuit which is activated by the constant current supplied from the transistor Tr2.
An N-channel MOS transistor Tr7 has a gate connected to the node N1, a drain connected to the power supply Vcc through a resistor R, and a source connected to the ground GND. An output terminal To which delivers the output signal Vout is connected to the drain of the transistor Tr7.
Referring now to FIG. 2, a second conventional comparator circuit 20 is shown. In the comparator circuit 20, the resistor R of the comparator circuit 10 is replaced by a P-channel MOS transistor Tr8 having a gate connected to the gates of the transistors Tr1 and Tr2.
The transistor Tr8 operates as a constant current source which supplies an idling current to the output terminal To. The idling current from the transistor Tr8 is chosen to be sufficiently small as compared with a maximum drain current from the transistor Tr7.
In the comparator circuit 20, when the drain current from the transistor Tr7 is greater than the idling current from the transistor Tr8, as attributable to a rise in the potential at the node N1, the output signal Vout is established at its L level.
On the other hand, when the drain current from the transistor Tr7 is less than the idling current from the transistor Tr8, as attributable to a reduction in the potential at the node N1, the output signal Vout is established at its H level.
The comparator circuit 20 may also be operated as an op amp circuit by feeding the output signal Vout back as the input signal Vin2.
Referring to FIG. 3, a third conventional comparator circuit 30 is shown. In the comparator circuit 30 shown, the resistor R of the comparator circuit 10 is replaced by a P-channel MOS transistor Tr9, the gate potential of which is controlled by P-channel MOS transistors Tr10 and Tr11. The transistors Tr7 and Tr9 are chosen such that they exhibit substantially equal load driving capabilities.
The transistor Tr10 has a source connected to the power supply Vcc, a gate connected to the gates of the transistors Tr1 and Tr2 and a drain connected to the gate of the transistor Tr9 and to the source of the transistor Tr11. A constant drain current passes through the transistor Tr10. The transistor Tr11 has a gate connected to the node N1 and a drain connected to the ground GND. A drain current from the transistor Tr10 is chosen to be sufficiently smaller than a maximum drain current of the transistor Tr11.
In the comparator circuit 30, when the transistor Tr7 is turned on as attributable to a rise in the potential at the node N1, the source potential of the transistor Tr11 or the gate potential of the transistor Tr9 rises, causing the transistor Tr9 to be turned off, establishing the output signal Vout at its L level.
On the other hand, when the transistor Tr7 is turned off due to a fall in the potential at the node N1, the source potential of the transistor Tr11 or the gate potential of the transistor Tr9 is reduced, causing the transistor Tr9 to be turned on, establishing the output signal Vout at its H level. In this manner, the transistors Tr7 and Tr9 operate in a push-pull mode in accordance with a change in the potential at the node N1.
The comparator circuit 10 in FIG. 1 (according to the first prior art) has a difficulty obtaining a maximum utilization of the current driving capability of the transistor Tr7. Referring to FIG. 1 again, when the transistor Tr7 is turned off, the source (or discharge) current Iso delivered to a load from the output terminal To is given as follows: EQU Iso=(Vcc-Vout)/R
and the source current varies with a change in the output signal Vout.
The source current Iso is reduced when the resistor R has a relatively high resistance. When a load connected to the output terminal To is excessive, a rise of the output signal Vout from its L to its H level may be retarded.
By contrast, the source current Iso may be increased by reducing the resistance of the resistor R. However, when a sink current Isi is drawn into the transistor Tr7 from the output terminal To as the transistor Tr7 is turned on, the source current Iso may retard the flow of the sink current Isi, thus retarding the falling edge of the output signal Vout. Since the current flow from the power supply Vcc through the resistor R and transistor Tr7 to the ground GND increases, the current dissipation of the comparator circuit 10 increases.
The drain current of an MOS transistor generally increases as the potential difference between the gate potential Vg and the source potential Vs increases. Denoting the gate-source voltage of the transistor Tr3 by Vgs (Tr3) and its source-drain voltage by Vds (Tr3), the potential at the node N1 or the gate potential Vg (Tr7) of the transistor Tr7 is given as follows: EQU Vg(Tr7)=Vin1+Vgs(Tr3)-Vds(Tr3)
When the level of the input signal Vin1 falls, the potential at the node N1 rises. However, the potential at the node N1 cannot rise close to the level of the power supply Vcc as a result of a suppressing effect of the input signal Vin1. This means that it is difficult to achieve a gate potential for the transistor Tr7 which allows its full movement from the supply voltage Vcc to the ground GND level. Similarly, a gate potential for the transistor Tr7 which allows its full movement also cannot be obtained in the second and the third prior circuits 20, 30. Accordingly, the current driving capability of the transistor Tr7 cannot be used to its full extent when the output signal Vout of the L level is delivered, such that the falling rate of the output signal Vout cannot be fully accelerated.
By contrast, in the second circuit 20, it is possible to establish a constant source current Iso which is supplied from the output terminal To to the load by the drain current from the transistor Tr8 when the transistor Tr7 is turned off to deliver the output signal Vout of the H level.
However, when enough source current Iso is secured, the source current Iso retards the flow of the sink current Isi as the transistor Tr7 is turned on to draw the sink current Isi from the output terminal To, such that the falling rate of the output signal Vout is retarded while simultaneously increasing the current dissipation.
In the third circuit 30, a change in the potential at the node N1 is reflected in the gate potential of the transistor Tr9. When the sink current Isi into the transistor Tr7 increases due to a rise in the potential at the node N1, the gate potential of the transistor Tr7 rises, thus limiting the source current Iso. On the other hand, when the sink current Isi into the transistor Tr7 decreases due to a fall in the potential at the node N1, the gate potential of the transistor Tr9 falls to increase the source current Iso. Accordingly, the source current Iso of the transistor Tr9 is controlled in accordance with the load.
The potential difference between the gate of the transistor Tr7 and the gate of the transistor Tr9 corresponds to the gate-source voltage of the transistor Tr11. When the potential at the node N1 is around Vcc/2, the transistors Tr7 and Tr9 are both turned on. Accordingly, an increased current flow from the power supply Vcc through the transistors Tr9 and Tr7 simultaneously to the ground GND, presenting a problem of an increased current dissipation. Since the gate-source voltage of the transistor Tr11 varies due to variations from transistor to transistor during their manufacturing process or a change in the ambient temperatures of the transistors, it is not a simple matter to construct a circuit which accurately maintains the magnitude of the current flow.


A method is disclosed for adapting, in a self-training procedure, an equalizer based on distributed-arithmetic design. In such an equalizer, in each modulation interval addresses are derived from stored received signal samples x.sub.n.sup.q to choose some of the values stored in a look-up table. The chosen table values are combined by shift-and-add operations to obtain an equalizer output value y.sub.n. According to the novel adaptation scheme, only one of the chosen look-up table values is selected per modulation interval, for updating it in a particular fashion to reduce the error detected. The disclosed scheme ensures uniform selection of the stored look-up table values for updating. Only one additional shift-and-add operation is required per modulation interval to achieve satisfactory adaptation of the equalizer. No training sequence is required to be transmitted, and the scheme converges in all situations.

The present invention is concerned with adaptive equalization of channels for data transmission or storage, and in particular with a method of adapting a distributed-arithmetic equalizer by updating a look-up table containing values that determine the equalizer characteristics, and further with look-up table updating means in an adaptive distributed-arithmetic equalizer apparatus for channel equalization in a partial-response communication or storage system.
A self-training adaptive equalization scheme is known from the following publication: Y. Sato, "A Method of Self-Recovering Equalization for Multi-Level Amplitude Modulation Systems", IEEE Trans. Comm., Vol. COM-23, pp. 679-682, June 1975. In the scheme disclosed, updating of the equalizer coefficients requires N multiplications as well as the computation of a particular function g.sub.k ; the latter requires, in the case of Partial-Response Class-IV (PRIV) signaling, an inversion of the PRIV channel and generation of a two-level PRIV signal. Furthermore, in the steady state the described linear adaptive equalizer undergoes enhanced tap noise with respect to a decision-directed adaptive equalizer.
A new filter design was disclosed in an article by A. Peled et al. "A New Hardware Realization of Digital Filters", IEEE Trans. Acoustics, Speech, Signal Processing, Vol. ASSP-22, pp. 456-462, December 1974. The new technique has become known as "distributed-arithmetic" filter design. However, the publication does not disclose any application of the filter as an adaptive equalizer.
An adaptive equalizer using a distributed-arithmetic architecture was described in the following publication: C. F. N. Cowan et al., "A Digital Adaptive Filter Using a Memory-Accumulator Architecture: Theory and Realization", IEEE Trans. Acoustics, Speech, Signal Processing, Vol. ASSP-31, pp. 541-549, June 1983. The look-up table value updating scheme disclosed in this article is based on a least mean-square algorithm, and no attempt is made to use the distributed-arithmetic equalizer in a self-training mode. For training the equalizer, transmission and recognition of a training sequence would normally be required.
It would be desirable to have an equalization method and apparatus avoiding the disadvantages of known equalization devices and procedures. Therefore it is an object of the invention to provide an equalization scheme using a distributed-arithmetic technique, which is self-training on the received data signal and therefore needs no training sequence.
It is another object to devise a self-training adaptive equalization scheme with low tap noise in the steady state.
It is a further object to provide a self-training adaptive equalization scheme which allows a reduction in hardware complexity for the equalizer apparatus.

Method for self-training adaptive equalization

International Business Machines Corporation


An error correction code generator uses an additional static random access memory (SRAM) or a multi-symbol encoder to improve the encoding efficiency. During the encoding operation, the number of the data access of the dynamic random access memory (DRAM) with the row address switching can be reduced considerably via using the additional SRAM or multi-symbol encoder. Hence, the efficiency of the data access of the DRAM is improved and the encoding time of the error correction code generator is reduced.

1. Field of the Invention
The present invention is related to an error correction code generator, and more particularly, to an error correction code generator that uses an additional static random access memory (SRAM) or a multi-symbol encoder to improve the encoding efficiency thereof.
2. Description of Related Art
Traditionally, in a process for generating error correction codes, such as in the encoding process executed before recoding data on a digital versatile disc (DVD), the source data are usually pre-stored in a dynamic random access memory (DRAM). In the conventional DRAM, the stored data are usually addressed by the row and column addresses, and the DRAM is divided into multiple memory blocks according to the row and column addresses.
When the error correction code generator accesses the data stored in the DRAM, a row address and a column address are sent to the DRAM to indicate which data to be accessed. However, in order to make the data access more efficient, the conventional DRAM generally has a page-mode access function. In other words, if the data to be accessed have the same row address, i.e. they have the same memory page, the error correction code generator only needs to send the row; address when accessing the first data. The following data can be accessed just by sending the column addresses.
Furthermore, the DRAM only charges the memory blocks with the same row address when activating those memory blocks. Hence, every time the error correction code generator tries to access data with a different row address, it not only needs to send a row address but also to wait for a predetermined charge time. Thus, if the number of the row address switching of the data to be accessed increases, the access efficiency of the DRAM will decrease considerably.
In a conventional process for generating error correction codes, such as a process for generating parity of outer codes (PO codes) of Reed-Solomon product code (RSPC), accessing data blocks with different row addresses is often necessary. As a result, it needs to switch the new row address and wait for the predetermined charge time to access the data in different row addresses and the efficiency for generating the error correction codes is limited. Hence, the conventional process for generating error correction codes will consume a lot of time.
Please refer to FIG. 1, which is a conventional data structure for the Reed-Solomon product code. The conventional data structure includes three blocks, which are composed of multiple sub-blocks. Each of the sub-blocks represents a symbol of the operation of the error correction code and includes a byte of data. The sub-blocks are respectively marked as {Bi, j, i=0-207, j=0-181}.
The block at i=0-191 and j=0-171 is the scrambled source data; the block at i=192-207 and j=0-171 is the PO codes of Reed-Solomon product code; and the block at i=0-207 and j=172-181 is the parity of inner codes (PI codes) of Reed-Solomon product code.
The PO codes are the vertical parity codes of the source data. For example, the PO code of the PO column with i=0, B0-191, 0, is B192-207, 0. The PI codes are the horizontal parity codes of the source data. For example, the PI code of the PI row with j=0, B0, 0-171, is B0, 172-181.
Please refer to FIG. 2, which is a schematic diagram for illustrating the arrangement of the scrambled source data in the DRAM. Before encoding, the conventional error correction code generator generates a sequence of scramble bytes in advance to scramble the source data received from the host. Then, it stores the scrambled source data into the DRAM. Finally, the error correction code generator encodes the scrambled source data according to the Reed-Solomon product code.
By comparing FIG. 1 with FIG. 2, the stored DRAM addresses of the scrambled source data are shown. It is noted that the storage unit of the DRAM is "word", which is equal to two bytes in this case. The order of storing the scrambled source data is (B0,0, B0,1, . . . B0,171, B1,0, . . . ).
According to the order of storing the scrambled source data, the row addresses of the source data for generating the PO codes of Reed-Solomon product code are frequently switched. Hence, in the process for generating the PO codes, the efficiency of conventional error correction code generator is low (the following description is directed to this question).
Please refer to FIG. 3, which is a block diagram of a conventional error correction code generator. The conventional error correction code generator 30 includes a first memory (DRAM) 31, a multiplexer 32 and an encoder 33. In the process of encoding, the host sends source data to the error correction code generator 30. Then, the error correction code generator 30 scrambles the source data and stores the scrambled source data into the first memory 31.
Then, the error correction code generator 30 accesses the scrambled source data stored in the first memory 31 column by column for generating the PO codes. However, as shown in FIG. 2, the storage unit of first memory 31 is "word". Hence, two bytes of the data are read from first memory each time, and the multiplexer 32 selects the required byte of these two bytes and passes it to the encoder 33 for encoding.
Please refer to FIG. 2 again. According to the encoding structure and method described above, the operation of the vertical encoding should be executed 172 times to complete the total process for generating the PO codes. However, in order to execute the operation of the vertical encoding, e.g. encoding the data in B0-191,0 to generate the corresponding PO code in B192-207, the data accessing operation with row address switching should be performed 135 times and the data accessing operation without row address crossing should be performed 57 times.
Therefore, to complete the whole process for generating the PO codes, it totally performs 172×135=23220 times of the data access with row address switching and 172×57=9804 times of the data access without row address switching. Since the data access with row address switching is more time-consuming and this encoding method needs to access data mostly with row address switching, this encoding structure is inefficient and consumes a lot of time.
Accordingly, as discussed above, the prior art still has some drawbacks that could be improved. The present invention aims to resolve the drawbacks in the prior art.


A latch assembly for use a tire carrier has a wheel plate and a lock bracket and an aperture and a flexible member disposed in the aperture and connected to a wheel plate. The latch assembly has a lock housing, a guide adjacent and a lock arm. The lock arm has one end, another end, a cam surface and a lower cam surface. The one end is pivotally connected to the guide. The lower cam surface extends past the bottom of the lock housing. The weight of the housing acts on a stop member attached to the flexible member, to form a force to urge the lock arms to an unlocked position. When another end is moved toward the lock bracket, the cam surface engages the lock bracket to pivot the lock arm to a locked position so that when the flexible member breaks, the lock arm engages the lock bracket.

Vehicles with inflatable tires such as passenger cars, light and heavy duty trucks, tractor trailers, buses, commercial delivery vehicles, among other motorized forms of transportation and trailers pulled by such vehicles are conventionally equipped with spare tires. Some spare tires are stored under the vehicle using a tire carrier which includes a tire winch for raising and lowering the spare tire between a raised or stored position and a lowered or accessed position. The winch typically raises and lowers the spare tire using a flexible member such as a cable or cord, which is wound and unwound on a spool or reel. A secondary latch is often provided to secure the spare tire in the stored position. If the flexible member or winch fails while the spare tire is in the stored position, the secondary latch ensures that the spare tire remains in the stored position.
For example, U.S. Pat. No. 5,188,341, the disclosure of which is expressly incorporated herein in its entirety, discloses a secondary latch for a tire carrier. The secondary latch includes a latch member, which is pivotally mounted to swing a pair of arcuate fingers between a locked position and an unlocked position. The lock member is biased to the locked position by gravity. The lock member is selectively pivoted to the unlocked position by a lever, which is activated by a cranking member when engaging the winch.
In U.S. Pat. No. 6,079,932 a safety latch assembly is disclosed, which includes a pair of pivoted and spring loaded opposed latched to engage the shoulder portion of a support member. One latch has a cam or teeth to cause pivotable movement of the other latch. An actuator is required to pivotally move one latch on a pivot pin against the force of a spring to unlatch the shoulder. The pivotal movement of the one latch caused by the actuator moves the bottom end of the one latch outwardly and away from the shoulder and moves the top ends of the one latch inwardly in a latch housing. This movement of the one latch pushes the cam surfaces together to pivotally move the other latch against the force of its associated spring to unlatch the shoulder and release the safety latch.
Another example is shown in U.S. Pat. No. 6,267,546 issued to Dura Global Technologies, Inc, the disclosure of which is expressly incorporated herein in its entirety. The secondary latch assembly includes a sliding latch member supported by a horizontal support surface and an actuator adapted to selectively move the latch member along a linear path between a locking position and an unlocking position. The latch member is adapted to permit passage of the shank portion but not the head portion past the latch member when the latch member is in the locking position and to permit passage of both the shank portion and the head portion past the latch member when the latch member is in the unlocking position. The actuator includes an arm pivotable between the locking position and the unlocking position and having one end extending through an opening formed in the latch member such that pivotal movement of the arm linearly moves the latch member. The actuator further includes a spring member biasing the arm to the locking position. Various alternative embodiments are also disclosed wherein the actuator arm is connected to the latch member with a pin-and-slot connection and wherein the latch member has resilient fingers.
While these secondary latches may effectively retain the spare tire in the stored position under some conditions. They have numerous shortcomings. For example, these mechanisms are fairly complex require a relatively large number of parts, and are subject to corrosion from road salt. Accordingly, there is a need in the art for a secondary latch, which has reduced a number of total parts, is less prone to salt corrosion, and has reduced assembly complexity.
The present invention provides a latch mechanism for a vehicle, which overcomes some of the above-noted problems of the related art. According to the present invention, a latch assembly is adapted for use with a vehicle tire carrier. The tire carrier has a flexible member, a tire and a lock bracket. The lock bracket has a portion forming an aperture. Additionally, a hook mechanism is disposed in the aperture for latching the tire to the lock bracket when the flexible member breaks.
The advantage of the present invention is that the latch device is simple, more reliable and requires fewer parts. From the foregoing disclosure and the following more detailed description of the preferred embodiment, it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of latching mechanisms. Particularly significant in this regard is the potential the invention affords for providing a lightweight, high quality, feature-rich, low cost assembly. Additional features and advantages of the preferred embodiment, will be better understood in view of the detailed description provided below.
It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of a latching mechanism as disclosed herein, including, for example, specific shapes of the lock member or actuator arm will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. All references to direction and position, unless otherwise indicated, refer to the orientation of the tire carrier illustrated in the drawings. In general, up or upward refers to an upward direction in the plane of the paper and down or downward refers to a downward direction in the plane of the paper.

This patent is subject to a terminal disclaimer.