A system for inspecting the reliability of an image. The system may include a processor in communication with a client device; and a storage medium. The storage medium may store instructions that, when executed, configure the processor to perform operations including: obtaining a plurality of images; categorizing the images into a plurality of image classes; calculating a plurality of probability outcomes; determining whether highest predicted probabilities of the images are less than a first threshold and whether an entropy of a predicted density of the probability outcomes exceeds a second threshold; indicating whether the image is associated with the image classes; ranking, the image amongst the plurality of images; filtering, a plurality of low reliability images according to a third threshold; providing, a likelihood of whether a user scanned a vehicle object associated with the image; and identifying a percentage of user scan failures.

Vehicle detection algorithms using computer-implemented image analysis are used in accordance with different approaches. For example, in some approaches, image sensors capture a plurality of image frames as part of a video sequence, and a system may analyze the captured image frames to provide vehicle detection. One or more classifiers may then be applied and a confidence score may be calculated in order to identify a vehicle in a captured vehicle image.
In other approaches, vehicles may be identified in accordance with horizontal and vertical edge detection, and vehicle categorization schemes may be presented to distinguish between types of vehicle (e.g. cars, SUVs, hybrids, and trucks) based on dimensional ratios. In some approaches, existing vehicle detection algorithms may focus exclusively on identifying a vehicle class and a non-vehicle class based on a variation of vehicle attributes, characteristics, or templates within training modules.
In other approaches, highly accurate vehicle identification based on only vehicle characteristics is possible with techniques based on machine-learning algorithms such as convolutional neural networks. These algorithms capture characteristics from images of known vehicles and then identify an unknown vehicle in an image by correlating image characteristics. Although these techniques may be computer-intensive, they can improve identification accuracy and facilitate the automation of a vehicle image identification system.
While the proliferation of automated vehicle detection algorithms based on image analysis has improved vehicle recognition, there remains a need for removing captured vehicle images that are mislabeled or inaccurate. Indeed, the accuracy and performance of many vehicle detection algorithms may be limited based upon mislabeled or inaccurate images in a training image set. For example, some captured images may include vehicle advertisements, toys, or related vehicle indicia that do not accurately constitute an actual vehicle, thereby limiting a vehicle detection algorithm's ability to accurately and precisely detect vehicles in other images. Thus, an improved method for finding mislabeled images, ranking the reliability of a captured image (that is, the likelihood of an image being inaccurate), and purging outlier images is required.
Moreover, identification of vehicles using handheld devices is also desirable to exploit handheld device capabilities and develop new applications. However, identification of vehicles using image analysis in handheld devices has multiple technical challenges. First, the machine-learning methods that provide enough precision for image analysis are computer-intensive and may be difficult to perform in a handheld device. These methods normally require the analysis of a plethora of well-curated training images before an identification process may be performed. Second, portable image identification of images needs to be performed quickly to be user-friendly. Particularly for augmented reality applications, in which users are expecting an immediate response, it is imperative to have efficient computing identification methods and communication systems that facilitate image recognition. Third, images or video feeds taken with a mobile device may not be uniform and may have different qualities and/or formats. Because image analysis using machine-learning methods is heavily dependent on the content relevance of a captured target image, the accuracy rate of these methods on images taken with mobile devices may be confounded by the content relevance of these captured images. Fourth, handheld devices have limited display screen space. Applications that require both image acquisition and display of information in a single screen, such as augmented reality applications, require specific graphical user interfaces so the user can comfortably see and manipulate the information.
The disclosed machine-learning artificial intelligence system and analytical inspection methods address one or more of the problems set forth above and/or other problems in the prior art.

Artificial intelligence system for inspecting image reliability


Given the complexity of architectural spaces and the need to calculate spherical irradiances, it is difficult to determine how much ultraviolet radiation is necessary to adequately kill airborne pathogens. An interior environment with luminaires is modeled. Spherical irradiance meters are positioned in the model and the direct and indirect spherical irradiance is calculated for each sensor. From this, an irradiance field is interpolated for a volume of interest, and using known fluence response values for killing pathogens, a reduction in the pathogens is predicted. Based on the predicted reduction, spaces are built accordingly, and ultraviolet luminaires are installed and controlled.

Ultraviolet radiation has been used to disinfect the air in hospitals and other healthcare facilities for over eighty years. Aerosols that are generated by infected patients coughing, sneezing, or even talking may contain bacteria or viruses responsible for such diseases as tuberculosis, measles, chickenpox, smallpox, SARS, MERS, Ebola, and COVID-19.
In a typical application in FIG. 1 (adapted from Kowalski 2009), ultraviolet-emitting lamps 10 with appropriate shielding are mounted on the wall above the line of sight of the room occupants (usually referred to as the "upper room") and their radiation 12 directed horizontally to irradiate the aerosol particles. The irradiation zone is above a height of 2.1-2.5 m (7-8 feet) and the amount of irradiation is 0.005-0.01 W/m2. The lower room irradiance levels are <0.002 W/m2 for UV-C and <0.001 W/m2 for broadband UV. The ultraviolet radiation is absorbed by proteins, DNA, and RNA within the pathogen cells, which in turn damages their nucleic acids, causing cell death in bacteria and inactivation in viruses. Critically, the disinfected air must be regularly exchanged with outside air and circulated throughout the lower occupied room space using ceiling fans or forced-air ventilation to benefit the room occupants.
The susceptibility of bacteria and viruses to ultraviolet radiation varies by species and by the radiation wavelength. For bacteria and viruses containing DNA, the wavelength dependence is determined by the spectral absorbance of DNA. As shown in FIG. 2 (adapted from Table 2 of CIE 155:2003, Ultraviolet Air Disinfection), the range of effective wavelengths is approximately 200 nm to 310 nm, otherwise identified as within the range of ultraviolet-C (UV-C) radiation (100 nm to 280 nm) and ultraviolet-B (UV-B) radiation (280 nm to 315 nm). UV-B radiation is carcinogenic and relatively ineffective as a disinfection agent, and so UV-C radiation is most commonly employed for the purpose.
There are three common methods for determining the susceptibility of pathogens to UV-C radiation in the laboratory: 1) irradiation of pathogen colonies on a culture plate or Petri dish; 2) irradiation of pathogens suspended in water; and 3) irradiation of aerosolized particles. Once this has been determined for a pathogen species of interest, an ultraviolet germicidal irradiation (UVGI) system can be designed for an enclosed space, such as for example a hospital room or ward.
As can be seen from FIG. 2, the peak susceptibility of pathogens to UV-C occurs at about 270 nm. Low-pressure mercury-vapour lamps—basically linear fluorescent lamps with fused quartz rather than soda-lime glass tubes and without phosphor coatings—emit monochromatic UV-C radiation at 254 nm. At this wavelength, the susceptibility is about 85% of that of the peak susceptibility at 270 nm, but the lamps are still effective germicidal agents.
A disadvantage of 254 nm radiation is that it poses a photobiological risk to occupants in the "lower room." Care must be taken to ensure that the exposure to UV-C irradiance over time (referred to as the UV-C "dose") does not exceed the Threshold Limit Values (TLVs) established by the American Conference of Governmental Industrial Hygienists. Excess exposure can result in photokeratitis ("snow blindness"), photoconjunctivitis ("pink eye"), and erythema ("sunburn").
As noted for example by Kowalski, W. 2009 Ultraviolet Germicidal Irradiation Handbook. Heidelberg, Germany: Springer in Section 9.6, Performance, "the effectiveness of upper room air disinfection depends on ultraviolet power, fixture location, local reflective surfaces, degree of air mixing between the stratum and lower room volume, microbial susceptibility, and relative humidity."
In relation to the above, Kowalski (2009) references Rudnick, S. N., and M. W. First. 2007. "Fundamental Factors Affecting Upper-Room Ultraviolet Germicidal Irradiation—Part II. Predicting Effectiveness," J. Occupational and Environmental Hygiene 4:352-362, wherein "ultraviolet power" is defined as the ultraviolet radiant flux (measured in watts) incident on a plane placed near an ultraviolet fixture (or "luminaire").
Rudnick and First (2007) further note that reflections of UV-C radiation from surfaces in the upper room can be important, and present an approximation based on Sumpner's Principle (e.g., Cuttle, C. 1991. "Sumpner's Principle: A Discussion," Lighting Research and Technology 23(2):99-106). As will be obvious to one skilled in the art of illumination engineering, this is an extreme simplification that is appropriate for modeling empty rectangular rooms only (e.g., FIG. 1).
As will be further evident to one skilled in the art of illumination engineering, the design and analysis of UVGI systems is no different from that of architectural lighting design and analysis using visible light. If the radiant intensity distribution of the UV-C luminaire has been measured in an optical test laboratory and the UV-C reflectances of the room surfaces are known or can be estimated, the principles of architectural lighting design and analysis can be used to predict the distribution of UV-C radiation anywhere within an enclosed space.
The problem, however, is that architectural lighting design and analysis is concerned with the illuminance of physical and virtual surfaces. The design and analysis of UVGI systems, by comparison, is concerned with the "spherical irradiance" (also referred to as the "radiant fluence rate") at arbitrary positions within the volume of air in the upper room.
The CIE International Lighting Vocabulary defines spherical irradiance as:Ee,o=∫4πLedΩ  (1)with dΩ being the solid angle of each elementary beam of radiation passing through the given point, and Le is its radiance at that point. It further defines "radiant fluence" He,o as the time integral of the spherical irradiance Ee,o at a given point over a given duration:He,o=∫ΔtEe,odt  (2)
Conceptually, radiant fluence (also referred to as "dose" in medical literature) is the quotient of the radiant energy of all radiation incident upon the outer surface of an infinitesimally small sphere centered at the given point by the area of the diametrical cross-section of the sphere. With typical diameters of 0.5 to 5.0 micrometers, aerosolized viruses and bacteria may be considered as elementary spheres for the purposes of optical radiation design and analysis.
Rudnick and First (2007) note that the radiant fluence rate: " . . . is difficult and time consuming to measure because the fluence rate in the irradiated zone can vary considerably in both vertical and horizontal directions. Therefore, a large number of measurements must be made, particularly near the fixture where the fluence rate changes considerably over relatively short distances. In addition, the measurement must include the UV energy arriving from all directions; thus, a flat detector should not be used close to a UV source or if the room contains multiple UV sources."
The "flat" detector referred to by Rudnick and First (2007) is a conventional ultraviolet radiometer with a sensor that measures the irradiance of a plane, such as the Model 8.0-RP UVC meter with Remote Probe manufactured by Solarmeter (Glenside, Pa.). In terms of architectural lighting design and analysis, it is equivalent to an illuminance meter (FIG. 3).
Kowalski (2009) recommended in Section 9.7, Testing that, "When multiple fixtures exist in a room and face each other on opposite walls, the question may arise as to how to handle the measurements. It is appropriate in such cases to take two measurements facing opposite and add them directly, provided that there are no additional fixtures contributing to the local irradiance field. The result of this approach will approximate the same result obtained through the use of spherical sensors, such as are used in spherical actinometry." For ultraviolet measurements, these "spherical sensors" are typically comprised of centimeter-diameter quartz spheres that are filled with a chemical such as ferrioxalate, persulfate or iodide/iodate; their transmittance after exposure is linearly proportional to the UV-C fluence.
The measurement procedures recommended by Rudnick and First (2007) and Kowalski (2009) measure a rough approximation of the spherical irradiance when multiple luminaires are present, but they do not take reflection of ultraviolet radiation from room surfaces into consideration. More accurate measurements can be made using an AMOUR (Advanced Multi-purpose USB Radiometer) with a "scalar irradiance" (a synonym for spherical irradiance) collector and a narrowband ultraviolet filter as manufactured by Biospherical Instruments (San Diego, Calif.). However, such an instrument has a "blind spot" of approximately 80 degrees where the spherical Teflon™ collector is mounted on its connector shaft.
These measurement procedures are, however, relevant to testing and commissioning an as-built UVGI system only; they do not assist in the design and analysis of the system prior to construction.
The design and analysis procedures for empty rectangular rooms described for example in Kowalski (2009) are usually sufficient for hospital rooms and wards. However, recent research has determined that far-ultraviolet (far-UV) radiation (specifically 222 nm radiation emitted by krypton-chlorine excimer lamps) likely does not pose the photobiological risks of 254 nm radiation generated by low-pressure mercury-vapour lamps (e.g., Buonanno, M., et al. 2020. "Far-UVC Light (222 nm) Efficiently and Safely Inactivates Airborne Human Coronaviruses," Scientific Reports 10:10285). Referring to FIG. 2, and extrapolating, the germicidal efficacy of 222 nm radiation is 3.8 times less than that of 254 nm radiation. Nevertheless, it may be practical to directly irradiate the occupied lower room as well as the upper room. This opens up the possibility of disinfecting the air in public gathering spaces, including hotel and bank lobbies, restaurant dining areas and kitchens, airport lounges, movie theatres and playhouses, and more. These spaces may include both new building construction and building retrofits.
In order to maximize the efficacy of the far-UV disinfection, it is necessary to model the air flow through the gathering space. The reduction in viral load of the aerosols is determined by the total UV-C fluence over a given period of time. There must therefore be a balance between the fluence rate and the air flow rate to ensure that the air has been sufficiently disinfected.
Air flow modeling can be accomplished using computational fluid dynamics (CFD), typically based on the finite volume method. This requires being able to predict the radiant fluence rate within each small volume of the air flow model.
Given a complex architectural space with multiple ultraviolet luminaires whose radiant intensity distributions are known and a plurality of architectural surfaces whose reflectances within the spectral region of interest are known, there is therefore a need for a system and method of predicting the spherical irradiance at a multiplicity of points in free space within the virtual environment.

Predicting spherical irradiance for volume disinfection


An image display device includes a display device driving circuit having a scanning signal driving section for outputting display scanning signals according to display data with respect to respective scanning signal lines for displaying an image which is in accordance with the display data with respect to pixels which are disposed in a matrix, and the display device driving circuit includes a control section for controlling the output of the display scanning signals from the scanning signal line driving section to the respective scanning signal lines based on a transition instruction signal for making a transition of output of the display scanning signals to the respective scanning signal lines from successive output to simultaneous output so that the display scanning signals are simultaneously outputted to the plurality of scanning signal lines.

With the advancement of communication infrastructure in portable electronic devices, particularly, in portable phones, more information (image information such as characters, graphics, illustrations, and photographs) are communicated at higher speed. In order to display these information, there is demand for a liquid crystal display section which makes up a display section of portable electronic devices to have a higher display quality with higher resolutions.
To increase resolutions in the liquid crystal display area means increase in number of dots, i.e., pixels, which results in increase in power consumption of the portable electronic devices. Meanwhile, a total power consumption of portable electronic devices needs to be low in order to extend the life of batteries making up a power source.
In order to meet this demand, there have been proposals to reduce power consumption by way of displaying only a required portion of the liquid crystal display section as an image display area.
Conventionally, partial display driving of a TFT (Thin Film Transistor) liquid crystal panel, which is an active-matrix liquid crystal display section, was performed in such a way that a non-image area and an image display area were driven at the same timing. Further, in the case of a simple-matrix liquid crystal panel, Japanese Unexamined Patent Publication No. 184434/1999 (Tokukaihei 11-184434) (published date: Jul. 9, 1999) discloses applying a white signal voltage in the non-image area by applying means prior to a transition into a partial display state. This publication partially recites partial display in a scanning direction of the active-matrix type.
However, in the foregoing publication, the applied voltage gradually changes, i.e., decreases in the pixels in the non-image area to which the white signal voltage was applied, and therefore it was required to apply another white signal voltage to maintain white display. That is, the foregoing publication discloses applying a voltage, equivalent to the voltage applied to the counter electrodes, once to the non-image area, and no subsequent application of the voltage is made to the non-image area (non-display portion). However, since the applied charge diminishes over time in the active-matrix liquid crystal panels, this method is not applicable to the active-matrix liquid crystal panels and it is required to apply a voltage for a certain period also in the non-image area. Thus, the foregoing publication failed to achieve lower power consumption, due to the application of a new white signal voltage.
Further, in the conventional method, in order to maintain the applied voltage, it was required in the active-matrix liquid crystal display panel having counter electrodes, when performing partial display in the scanning line direction, to apply a white signal voltage of the opposite polarity also to a non-display portion where the partial display in the scanning line direction is performed, so as to avoid such drawbacks as image persistence of the liquid crystal.
Conventionally, the non-display portion was scanned by the count-up of the shift register of the gate driver per one horizontal period in the same manner as the display portion. In this case, the output of video signals from the source driver needs to be created, apparently, for the number of outputs of the entire scanning lines, and the power consumption of the liquid crystal panel for the partial display becomes equivalent to that of entire display, thus failing to achieve lower power consumption.
Note that, Japanese Examined Patent Publication No. 2585463/1996 (published date: Jun. 11, 1992) discloses realizing display without change in time axis, when the number of scanning lines in the display area is larger than that of the effective scanning lines of the input video signals, by simultaneously scanning a plurality of scanning lines, other than the scanning lines of the effective display portion, in a retrace period within one frame period.
However, in the method as disclosed in the foregoing publication No. 2585463/1996, for example, when the effective display portion is positioned on the bottom of the display area (display screen), all areas are scanned normally and it fails to solve the foregoing problems. Further, while this publication teaches simultaneously scanning a plurality of scanning lines, other than the scanning lines in the effective display area, its purpose is to simplify the circuits when the number of horizontal lines in a vertical period (the number of horizontal counts in a vertical period) is smaller than the number of scanning lines of the display device, and it is not for realizing lower power consumption, and, in fact, the publication is silent as to operation for realizing lower power consumption. Thus, lower power consumption is not achieved. Further, the publication does not take into consideration the case where the number of horizontal lines in a vertical period (the number of horizontal counts in a vertical period) is larger than the number of scanning lines in the display device. Further, the foregoing publication is totally silent as to preventing flicker on the screen.

Display device driving circuit, driving method of display device, and image display device


A dynamic stabilization, motion preservation spinal implant system includes a deflection rod system implant. The system is modular so that various constructs and configurations can be created and customized to a patient.

The most dynamic segment of orthopedic and neurosurgical medical practice over the past decade has been spinal devices designed to fuse the spine to treat a broad range of degenerative spinal disorders. Back pain is a significant clinical problem and the annual costs to treat it, both surgical and medical, is estimated to be over $2 billion. Motion preserving devices to treat back and extremity pain have, however, created a treatment alternative to or in combination with fusion for degenerative disk disease.

This patent is subject to a terminal disclaimer.

Spine implant with a dual deflection rod system including a deflection limiting sheild associated with a bone screw and method


Charge is trapped into a charge trapping region of one of two reference cells so as to achieve a state equivalent to memory cell characteristics having a smallest amount of current. Charge is trapped into a charge trapping region of the other reference cell so as to achieve a state equivalent to memory cell characteristics having a largest amount of current. Currents output from these reference cells are averaged by a current averaging circuit, and the resultant average current is output as a reference current R_REF 1.

1. Field of the Invention
The present invention relates to a non-volatile semiconductor memory device, and more particularly, to a non-volatile semiconductor memory device of storing a plurality of pieces of information using different charge trapping regions in a charge trapping layer, in which a memory cell is composed of a MOS transistor having a charge trapping layer in a gate dielectric layer.
2. Description of the Related Art
Non-volatile semiconductor memory devices have been widely applied to information systems and communications systems because of their capability of holding memory information even when power source is switched off. Among them, a flash EEPROM (EEPROM: Electrically Erasable Programmable ROM, hereinafter referred to as a flash memory) performs an erase operation with respect to the whole chip or on a block-by-block basis, thereby reducing the size of each memory cell and achieving low cost. Therefore, there is a rapidly increasing demand for the flash memory.
Examples of a memory cell applicable to the flash memory include a memory cell with a double-layer polysilicon structure which is composed of a floating gate and a control gate, a memory cell composed of a MOS transistor having a charge trapping layer in a gate dielectric layer (hereinafter referred to as a MONOS memory cell), and the like. Among them, the MONOS memory cell is characterized in that one memory cell has two different regions each storing information, thereby making it possible to achieve low cost and large capacity, and that miniaturization is easily achieved. Therefore, those having the MONOS memory cell have become a mainstream flash memory (see, for example, U.S. Pat. No. 6,011,725).
In the flash memory having the MONOS memory cell, information is read from one of the two regions by, for example, comparing a magnitude of a read reference current output from a reference cell having the same structure as that of the memory cell with a magnitude of a memory cell current output from the one region of the memory cell.
When a program operation has been performed with respect to the memory cell, the memory cell has current characteristics such that a threshold value is shifted while holding current characteristics similar to current characteristics of the memory cell in an erased state. Therefore, by setting the read reference current output from the reference cell to have characteristics such that a threshold value is shifted while holding current characteristics equivalent to those of the memory cell current, an optimal reference can be created.
In this read operation, if the read reference current is set to be a mean current between a current of the memory cell in an information-erased state and a current of the memory cell in an information-programmed state, a difference between the reference current and the memory cell current in the erased state and a difference between the reference current and the memory cell current in the programmed state are equal to each other. Therefore, a margin between a program operation and a read operation can be maximized.
However, the MONOS memory cell has a specific effect that the memory cell current characteristics of one of the regions is affected by a state of the other region (hereinafter referred to as a second bit effect) (see, for example, U.S. Pat. No. 6,643,170).
For example, when, after information is set into one of the regions, information is programmed into the other region, the memory cell current characteristics of the one region vary. Therefore, in the case where the reference current is set as described above, the difference between the reference current and the memory cell current in the erased state and the difference between the reference current and the memory cell current in the programmed state are different from each other. The second bit effect is not dependent of a physical position of the charge trapping region in the memory cell, and is such that a state of a bit previously set is affected by a state of a bit written later.
As described above, in conventional non-volatile semiconductor memory devices having the MONOS memory cell, the memory cell current characteristics vary due to the second bit effect, so that the difference between the reference current and the current in each memory state is reduced, resulting in a small operation margin when information is read. Particularly, when a plurality of memory states are achieved by changing the amount of trapped charge to store multi-bit information, the reduction of the operation margin due to the influence of the second bit effect is significant.
Also, in the case of the MONOS memory cell, a predetermined range of voltage is applied to the memory cell, and therefore, in order to avoid the influence of the second bit effect, the reference current might be optimized in the vicinity of a middle of the applied voltage range, depending on the variation due to the second bit effect. In this case, however, the read margin is decreased in a lower limit portion and an upper limit portion of the voltage range.
Therefore, in conventional non-volatile semiconductor memory devices having the MONOS memory cell, it is difficult to achieve multi-bit memory. Even in a binary MONOS memory cell, if an operation margin is small, it is difficult to achieve a low-voltage operation.

Matsushita Electric Industrial Co., Ltd.


A medical device for use with a fluid transfer device includes a hub having an open proximal end with a frusto-conically-shaped cavity therein, a distal end and a passageway therethrough. The cavity is part of the passageway. A release element in the passageway of the hub is positioned to block fluid-tight engagement of the frusto-conically-shaped tip with the cavity of the hub. Structure is provided to release at least part of the release element, upon application of a proximally directed force on the hub, to allow the abrupt fluid-tight engagement of the tip and the cavity in the hub.

A hypodermic syringe consists of a cylindrical barrel, most commonly made of thermoplastic material or glass, with a distal end adapted to be connected to a hypodermic needle assembly or other medical device and a proximal end adapted to receive a stopper and plunger rod assembly. The stopper provides fluid-tight seal between itself and the syringe barrel so that movement of the stopper up and down the barrel will cause liquid, blood or other fluids to be drawn into or forced out of the syringe barrel through the distal end. The stopper is moved along the syringe barrel by applying axial force on a rigid plunger rod which is connected to the stopper and is sufficiently long to be accessible outside of the barrel. The stopper and the plunger rod can be integrally formed of one material such as thermoplastic.
Hypodermic needle assemblies, typically including a cannula and a hub, are often removably attached to syringes for performing a variety of tasks such as the delivery of medication into patients and into devices, and for withdrawing fluid samples from patients and from fluid sources. Usually, the hub of the hypodermic needle assembly has tapered interior surface adapted to engage the tapered tip of the syringe barrel so that the two components are joined in a frictional interference fit. The tapered syringe tip and the complementarily tapered receptacle in the hub are referred to as standard luer fittings. A wide variety of other medical devices such as stopcocks and tubing sets have standard luer fittings which allow them to be engaged to a syringe tip.
It is important that the frictional fit between the syringe tip and the needle hub or other medical device is strong enough to prevent accidental disengagement caused by the fluid pressures within the syringe and/or other factors such as forces applied to the needle hub when actuating safety needle shields connected to the hub. If the syringe tip becomes disengaged from the needle assembly, medication, blood or other fluids will be lost, and there is also potential for contamination.
The prior art teaches many structures for improving the connection between medical devices having tapered luer fittings such as needle assemblies and syringes. These structures include complementary engaging structure on both the needle hub and syringe barrel tip such as projections and recesses providing for a snap-fit arrangement. Manually releasable locking structures have been provided to increase the connection between the needle hub and barrel tip while allowing reasonable forces for disconnection of these components. Also, enhancements to the luer tip of the syringe barrel such as coatings, sandblasting and mechanical collars have provided for improved connection between a needle hub and a syringe barrel tip. Many of the structures taught by the prior art do not contemplate the subsequent removal of the needle assembly from the syringe barrel. Others require extensively modified needle hubs and barrel tips. Structures having a tapered luer fitting such as a needle assembly and syringe barrel are adequate for normal use when the needle assembly is properly installed on the syringe tip. Difficulties can arise if the user does not use enough force to frictionally engage the luer tapered surfaces which can result in inadvertent disconnection of the needle assembly.
Although the prior art teaches various devices and structures for improving the strength of the connection between a syringe barrel and the hub of a needle assembly or other fluid handling device, there is still a need for a simple, straight-forward, reliable needle hub or other fluid-handling device having structure which improves the strength of the connection with the syringe tip or other device having a standard tapered luer tip by requiring a minimum force of engagement.

Controlled release structure for attaching medical devices


According to the present invention, during performing an MRA sequence comprising a plurality (N) of pulse sequence units each of which gives blood flow a different phase rotation, one sequence unit is repeated a given number (L) of times in every cardiac cycle gated by ECG or pulse wave signals of the object under examination. A measurement of N cardiac cycles, as one round, is repeated to collect data completely filling a k-space for each sequence unit. In this repetition, the order of phase encoding magnetic fields is controlled so that data in the low frequency region of k-space are acquired at the cardiac phase corresponding to the diastolic phase of one cardiac cycle and data in the high frequency region are acquired at the cardiac phase corresponding to the systolic phase. The MRA of the present invention is not likely to be affected by the changes in blood flow caused by heart beats and does not prolong the time for measurement.

1. Field of the Invention
The present invention relates to a magnetic resonance imaging (abbreviated as "MRI" hereinafter) apparatus for obtaining tomograms of desired sections of an object to be examined by utilizing nuclear magnetic resonance (abbreviated as "NMR" hereinafter). In particular, it relates to a method for magnetic resonance angiography (referred to as "MRA" hereinafter), which is not likely to be affected by variation in blood flow rate caused by cardiac beat when imaging blood flow in a vascular system, and an apparatus therefor.
2. Related Art
In the MRI, a radio frequency magnetic field is applied to an object to be examined to excite atomic nucleus spins of atoms constituting living tissues of the object, and NMR signals elicited by the spins are acquired to form an image from the spatial distribution of the spins or spectra. When applying the radio frequency magnetic field, gradient magnetic fields are simultaneously applied to impart locational information. The atomic nucleus spins measured in MRI are usually atomic nucleus spins of hydrogen atoms. While the spins of atoms constituting tissues are static, the spins of atoms present in blood flows move. Based on this fact, various blood flow imaging techniques (MRA) using an MRI apparatus have been developed.
Most of such MRA techniques fall in three categories, i.e., the time-of-flight (TOF) method which utilizes the effect of blood inflow into slice planes, the phase-sensitive (PS) method utilizing subtraction of data acquired in the presence and absence of phase diffusion and the phase-contrast (PC) method utilizing subtraction of data acquired in two different conditions where the polarity of phase diffusion caused by blood flow is opposite.
The latter two utilize the fact that moving spins such as in blood flow experience phase modulation relative to their flow rate when the gradient magnetic fields are applied. In the PS method, blood flow imaging is performed by carrying out two kinds of sequences, one for applying gradient magnetic fields so that the phase of moving spins does not coincide with the phase of stationary spins at the timing of signal acquisition (dephase sequence) and another for applying gradient magnetic fields so that the phase of moving spins coincides with the phase of static spins at the timing of signal acquisition (rephase sequence), and using the difference between the data obtained by these sequences. The PC method utilizes a sequence for applying gradient magnetic fields with different polarities (called flow encode gradient magnetic fields) in the direction of blood flow to collect data and uses the difference between the acquired data. In this method, by generating six sequences, data for three axes can be obtained. A technique for obtaining data for three axes by generating four sequences has also been suggested for this method.
It is well-known that the blood flow rate of the vascular system, in particular, the arterial system, changes with the cardiac cycle. This variation in blood flow rate may cause variation in the intensity of the blood flow signal in the MRA measurement. In the PC method and the PS method in particular, the phase of moving spins changes with variation in the blood flow rate, and this leads to changes in the intensity of the differential signals. However, in the conventional methods, the signal acquisition is performed irrespective of the cardiac cycle. Therefore, depending on the cardiac phase when the echo signals are collected and the order of filling the components of the measurement space (space where data are arranged, also called k-space) with acquired data, contrast of the image obtained may change and artifacts may be produced.
Specifically, the phase of the spins is locational information obtained by applying the gradient magnetic fields. It may vary depending on the location in real space (in proportion to the distance from the magnetic field center) and should be inherently constant for each phase encode step. However, the spins of atoms constituting blood flow experience a rotation cyclically varying with the beating of the heart, and the locational information imparted to the blood flow signals therefore varies every encode step. As a result, blood flow signals cannot be formed into an image of one position but appear as artifacts drifting along the phase direction. This problem becomes pronounced particularly in the PC method and the PS method, because the flow encode pulse or dephase pulse for imparting a phase rotation in proportion to the flow rate to the constant flow is applied.
It is known that electrocardiography (ECG) gated measurement is effective for preventing the change of signal strength or artifacts caused by the heart beat. FIG. 10 shows a sequence for the PS method utilizing the ECG-gated measurement. In this sequence, a rephase sequence is repeated within one cardiac cycle and a dephase sequence is repeated within the next cardiac cycle to acquire one set of data for one phase encode step within two cardiac cycles. In this ECG-gated measurement, data for one image are always collected at a fixed cardiac phase and the k-space is filled with data of the same cardiac phase. Accordingly, in the measurement by the sequence shown in FIG. 10, image for each cardiac phase (L images for the first cardiac phase to the Lth cardiac phase) can be obtained and the images are free from nonuniformity of image contrast and artifacts.
However, in this method, measurement for one phase encode step is performed over two cardiac cycles. Therefore, in order to perform J number of encode steps necessary for constituting one image, it is necessary to repeat a sequence over cardiac cycles in a number of twice the number of the phase encode steps (2J). Therefore, supposing that one cardiac cycle is about 1 second and J is 256, one measurement takes about 8.5 minutes (=256.times.2/60). In the PC method, in addition, because one set of data for one phase encoding are obtained by a combination of four or six different sequences, the measurement time is further prolonged. Therefore, it may be practically impossible to utilize the ECG-gated measurement for three-dimensional imaging and hence its application may be limited to two-dimensional imaging.
Accordingly, the object of the present invention is to provide a method for MRA, which can provide stable images while obviating prolonged measurement time.

Method and apparatus for producing magnetic resonance angiogram


An internal combustion engine including a camshaft journalled in a bearing for rotational movement therein. The camshaft includes a main oil passageway extending axially therethrough and is in flow communication with the oil sump. The camshaft further includes an auxiliary passageway extending from the main passageway to a sidewall outer surface of the camshaft. A first lubricating passageway is formed within the crankcase and extends from the camshaft bearing to the cylinder head, and a second lubricating passageway is formed within the cylinder head and extends from the first passageway to the upper portion of the valve rocker mechanism of the engine. As the camshaft rotates upon engine operation, the auxiliary passageway in the camshaft is in periodic flow communication with the first passageway to provide a pulsed flow of oil to the first passageway. The oil then flows through the second passageway and lubricates the valve rocker mechanism. A return oil passageway extends from the lower portion of the rocker box through the cylinder head and crankcase into the interior of the crankcase, wherein the oil falls back into the sump.

The present invention relates generally to lubrication systems for engines, and more particularly, to a lubrication system for the upper valve mechanism of an overhead valve engine.
Horizontal crankshaft engines generally include breather induced upper valve mechanism lubrication systems, wherein the breather is located on top of the rocker box, and where an oil mist is induced to flow upwardly by the breather from the crankcase through both push rod tubes to the rocker box chamber to lubricate the valve actuating mechanism in the rocker box. Oil which condenses in the rocker box is then drained back downwardly along the side walls of the push rod tubes to the crankcase.
In vertical crankshaft engines, the above-described breather induced lubrication system does not perform satisfactorily due to several problems. First of all, when the engine is oriented in the head down attitude, oil will not drain from the rocker box to the oil sump, thus causing oil to build up in the rocker box. As enough oil builds up, the breather will pump oil from the rocker box to the exterior of the engine. However, this is unsatisfactory because of oil spillage on and around the engine and the loss of lubricating oil which can result in engine failure due to lack of lubrication.
It has been proposed to use a scavenging pump to remove the liquid oil from the rocker box and thereby prevent the build up of liquid oil therein. However, the provision of such a pump adds to the cost of the engine which is unsatisfactory.
More recently, a lubrication system has been developed, wherein the breather is remote from the rocker box, and the system utilizes crankcase breather induction of oil mist in a counter flow through two separate push rod tubes with the feeder push rod tube directly connected to the engine crankcase and the return push rod tube connected to the engine breather box which vents through a breather mechanism to the atmosphere. This lubrication system causes oil mist from the crankcase to flow up one push rod tube, circulate within the cylinder head rocker box to lubricate the valve mechanism, and then be induced by the crankcase breather into the breather box where a liquid oil is separated from the vapors. The liquid oil drains back into the crankcase, and the vapors are vented to the atmosphere through the remote breather mechanism. Such a system is shown in U.S. Pat. No. 4,601,267.
Another recently developed lubrication system provides lubrication to the upper valve mechanism without requiring the use of breather induction. This system employs a centrifugal oil slinger in the crankcase, which slings oil through a push rod cavity that is in communication with the crankcase at one end and in communication with the rocker box at the other end. The rocker arms in the rocker box are disposed one above the other, each oriented for rocking in a substantially horizontal plane. A dam is provided for restraining oil slung into the rocker box at a level such that the lower rocker arm is partially submerged in a pool of liquid oil. The turbulence of the lower rocker arm and valve spring generates enough turbulence in the accumulated pool to cause splash lubrication onto the upper rocker arm and its associated valve assembly. Such a lubrication system is shown in U.S. Pat. No. 4,881,496.

Pulsed pressure lubrication system for an overhead valve engine


A method and system for wireless data transmission between at least three stations use multiple frequency bands for simultaneous channel communications. The method includes transmitting a Request To Send (RTS) packet from a first station to an intermediate second station over a first frequency band. Two Clear To Send (CTS) packets, which CTS packets include transmission timing information, are then transmitted from the second station simultaneously both to the first station and to a third station. The CTS packet sent to the first station is transmitted over the first frequency band and the CTS packet sent to the third station is transmitted over a second frequency band. A data packet from the first station is then transmitted to the second station. The third station suspends, based on the transmission timing information included in the CTS packets, any unicast transmission to the second station during the transmission of the data packet from the first station to the second station.

1. Field of the Invention
The present invention relates generally to medium access control in wireless networks, and in particular to simultaneous half-duplex channel communications.
2. Description of Prior Art
Wireless Local Area Network (WLAN) protocols such as those based on the IEEE 802.11 standards are designed to recreate the high Quality of Service (QoS) that is typically supplied in wired networks that use standard LAN protocols such as Ethernet. High QoS includes uninterrupted network connections, high throughput and reliable delivery of data. However maintaining such high QoS in a WLAN is more difficult than in a wired network. The range and speed of wireless communications is often limited by, for example, interference and power limitations. Maintaining a high QoS in a WLAN therefore requires vigilant attention to error detection and correction and also requires careful monitoring of the conditions of the wireless link.
Despite their limitations, WLANs are frequently preferred over wired LANs, primarily because the user terminals of a WLAN are portable. Such portability makes possible Wireless Vehicle Area Networks (WVANs) and many Wireless Personal Area Networks (WPANs). However WLANs are also popular for other reasons. For example, with WLANs it is easy to use "ad hoc" networks that can be quickly assembled and torn down, and WLANs also may be more economical when compared with the high cost of infrastructure wiring.
The IEEE 802.11 standards concern the operation of a network's Media Access Control (MAC) layer. The MAC layer resides just above a network's Physical (PHY) layer and is responsible for controlling access to the wireless channel. The MAC receives MAC Service Data Units (MSDUs) from the higher layers. MSDU's may be fragmented into smaller MAC Protocol Data Units (MPDUs), which are then transported between network stations across the wireless medium. Network stations are devices connected to the network that may be mobile, portable, or stationary. MPDUs are transmitted between network stations using a carrier sense multiple access with collision avoidance (CSMA/CA) protocol. Collision detection such as that used in the Ethernet protocol cannot be used in wireless transmissions, because when a wireless station is transmitting it cannot hear other stations on the network as its own signal will interfere with any received signal. If all stations, be it subscribers or APs, have equal priority and timing access to the channel via CSMA/CA, then the IEEE 802.11 standards refer to the above method of channel access as the Distributed Coordination Function (DCF).
The 802.11 standards also describe a second channel access method for networks. This method, referred to as the Point Coordination Function (PCF), requires an AP to be present, and it uses polling to provide access to the wireless medium. The AP constructs a polling list that determines the order in which the stations within the network will be polled.
In an IEEE 802.11 network, stations are collected into a Basic Service Set (BSS). A BSS may comprise an ad hoc network where all stations in the network can communicate directly with all other stations. Alternatively a BSS may include an AP in which case it is called an infrastructure BSS. In an infrastructure BSS, all stations communicate exclusively through the AP. The AP is often connected to a wired LAN and therefore can significantly increase the range and resources available to a BSS.
Extensions to the existing IEEE 802.11 protocol include the IEEE 802.11(e) QoS extensions. These are based on both the CSMA/CA channel access method and on the polling method. In an infrastructure BSS that is providing QoS, a QoS AP (QAP) must schedule all data downlinks to all stations in the BSS and all data uplinks from the stations to the QAP. To avoid delay and jitter, all uplinks and downlinks must be scheduled efficiently. Optimizing such scheduling using a scheduling algorithm is often a complex process that requires consideration of numerous variables such as the specific QoS requirements of individual stations, fading disruptions, processing time, variable queuing time, and the load of individual stations (i.e., the amount of data queued at a station waiting to be uplinked to the QAP).
Additional variables need to be considered when scheduling multicast data traffic. In a multicast environment, only one member of a many-to-many multicast group is able to operate as a data traffic source at any given time. Often such multicast groups involve half-duplex group voice communications requiring "push-to-talk-release-to-listen" switches. For example, emergency response teams such as police and firefighters may use half-duplex voice over IP (VoIP) communications equipment to multicast a dispatch call to all team members and then to receive a response from a single team member. These multicast communications work on top of Transmission Control Protocol/Internet Protocol (TCP/IP) based networks, and use multicast routers to transmit IP packets to multiple destinations.
In a half-duplex group voice communication network, at any given time, generally only one member of the group can be an active transmitter. Further, the active group member who has the authority to transmit must often change rapidly from one member to another. Identifying the active group member who has the authority to transmit, as part of a multicast scheduling process, is generally done by polling. Such polling includes the Request to Send/Clear to Send (RTS/CTS) procedures that are described in the 802.11 standard. However, the RTS/CTS procedures define a four-way handshake that results in higher overhead, because two extra packets are required to be transmitted for each payload. Further, such overhead is multiplied when intermediate stations must act as relay points, such as in many WVANs. Other solutions for transmission scheduling include Time-Division Multiplexing (TDM)/reservation techniques that are complex, and which are generally undesirable as they do not form part of the 802.11 standard. There is therefore a need for an improved method and system for minimizing polling overhead by reducing the required number of RTS/CTS packets.

Medium access control for simultaneous channel communications


An oral appliance and kit therefor is disclosed. The oral appliance may include generally U-shaped upper and lower body members and a pair of adjustment plates or spacers for removably connecting the upper body member with the lower body member. The generally U-shaped upper and lower body members are adapted to be positioned over at least a portion of first and second arches of teeth, respectively, with the spacers having a system of pins or pegs for adjustably repositioning the upper body member with respect to the lower body member. The upper and lower body members are further configured to provide a lingual-less open space between the upper and lower body members to accommodate a tongue in a relaxed state. The disclosed oral appliance, system and kit therefor is configured for use in correcting the misalignment of a user's jaw.

Field of the Invention
The present invention generally relates to an oral appliance for corrective use, and more particularly to an oral appliance and kit therefor which includes generally U-shaped upper and lower body members and a pair of adjustment plates or spacers for removably connecting the upper body member with the lower body member. The generally U-shaped upper and lower body members are adapted to be positioned over at least a portion of a first or upper and a second or lower arches of teeth, respectively, with the spacers having a system of pins or pegs for adjustably repositioning the upper body member with respect to the lower body member. The upper and lower body members are further configured to provide a lingual-less open space between the upper and lower body members to accommodate a tongue in a relaxed state The disclosed oral appliance, system and kit therefor is configured for use in correcting the relative misalignment of a user's jaw and improving the alignment of the users jaw and tongue and related anatomical structures for improving a patient or users airway, breathing, and physiological performance.
Snoring, sleep apnea, bruxism, TMD, TMJ, and the like may cause general discomfort, pain and compromised breathing and cause a poor night's sleep. Such ailments may also contribute to poor overall health. Sufferers of these conditions may sleep with tensed jaw muscles, which may in turn cause teeth, either upper or lower teeth to sit forward or rearward so that the jaws push the tongue base toward the rear of the oral cavity. The tongue based rearward movement may obstruct the oral and nasal airways.
Description of the Related Art
A person suffering from snoring, sleep apnea, bruxism, TMD, TMJ, and the like, teeth-grinding, or frequent awakenings and restless sleep generally clenches and grinds his/her teeth while sleeping. Such a person may experience a variety of unpleasant symptoms including, for example, headaches, stiff neck, receding gums, misshapen and misaligned teeth, worn teeth, sleeplessness, tempromandibular disease (TMD) and/or an irritated sleeping partner, to name a few.
A mouth guard or oral appliance is a protective or treatment device for the mouth that covers, in part, the teeth and gums to prevent and reduce injury to the teeth, arches, lips and gums. A mouthguard is most often used to prevent injury in contact sports, as a treatment for sleep apnea, bruxism, TMD, TMJ; and the like, or as part of certain dental procedures, such as tooth bleaching. Depending on application, it may also be called a mouth protector, mouth piece, gumshield, gumguard, nightguard, occlusal splint, bite splint, or bite plane.
Devices that sought to correct these conditions are known in the art. A person wears such a mouth guard device over his/her teeth while sleeping, or at other times. Forces generated due to the clenching and grinding of the teeth are then distributed to the guard rather than directly to the opposing teeth. Although such devices are typically worn over the top teeth, they also include devices worn over the bottom teeth or over both the top and bottom teeth. Generally, however, acquiring one of these oral guard devices requires multiple trips to the dentist over a period of a few weeks, at extremely high cost, and without flexibility between trips (e.g., inflexibility to a particular process). First, a person must visit his/her dentist so that a custom mold of his/her top teeth can be created. Next, the custom mold is sent to a laboratory where is used to create a custom-fit guard. The custom-fit tooth guard is typically made of a hard plastic and may or may not include embedded wires or prongs to ensure a snug fit. Upon completion, the custom-fit tooth guard is sent to the dentist. Subsequently, during a second visit, the custom-fit guard is fitted over the person's top teeth to determine if adjustments are needed. If adjustments are needed, the dentist, using a sanding means or chiseling means suitable for use with the hard plastic material, fine-tunes the exterior surface and/or the interior surface of custom-fit oral guard.
However, in addition to requiring multiple trips to the dentist, custom-fit oral guards may be considered costly by some and therefore unavailable to those of limited financial means. In addition, these guards typically need periodic replacement because as the plastic ages, the guards no longer fit or become uncomfortable to wear. In other cases, the person's teeth may shift or change due to age, an accident, braces or other factors. Such a shift or change may necessitate that their existing custom-fit night guard be redesigned and replaced, thereby requiring more time be spent at the dentist and adding further expense. Further, in addition to being somewhat messy, traditional custom-fit night guards encourage the proliferation and build-up of plaque and dental carries due to saliva build-up in their interior region while being worn.
Accordingly, this invention now recognizes that there is a need for an adjustable oral appliance that is convenient and that can provide correction of a retruded, retracted user's jaw in order to support a relaxed jaw, and an increased tongue space, and airway improvement in the mouth for reduced snoring, improved breathing during sleep or other activities.

Apparatus and kit for an oral appliance and method for using same


A method for remotely controlling a big rig comprises a tractor unit and one or more trailers coupled to the tractor unit, wherein the tractor unit comprises a drive train which can be electronically actuated by the control of the tractor unit and by way of which the tractor unit can be driven automatically. The control of the tractor unit have a wireless communication link to a touchscreen device so that automatic driving of the big rig can be remotely controlled by way of the touchscreen device during which at least one articulation angle between a longitudinal axis of the tractor unit and a longitudinal axis of the trailer is continuously regulated.

The invention relates to a method for controlling the driving of a big rig comprising a tractor unit and one or more trailers coupled to the tractor unit. The invention likewise relates to a touchscreen device and to a drive control system for a big rig.
A variety of methods exist to assist a driver with maneuvering a vehicle, in particular a motor vehicle, having no trailer. Some methods broaden the field of vision of the driver by way of park distance control systems, cameras or the like. In other methods, individual driving tasks are taken over from the driver during maneuvering, in particular when parking the vehicle in parking spaces. If the driver and the vehicle also share the longitudinal and transverse guidance of the vehicle in a parking steering system, the entire task of driving is taken over from the driver during autonomous parking. The driver is then only responsible for activating and deactivating the parking process.
Methods are also known already for assisting the driver with the maneuvering of a big rig comprising a tractor unit and a trailer.
DE 10 2005 045 196 A1 relates to a device for assisting the driver of a tractor unit during back-up maneuvers of a big rig composed of a tractor unit and a trailer coupled to the tractor unit. The device comprises the following components: a camera, which can be mounted in the rear area of the trailer and by way of which an image of a surroundings area of the trailer located in the reverse driving direction can be captured; a steering angle sensor, by way of which a wheel steering angle of steerable wheels of the tractor unit can be detected; and/or an articulation angle sensor, by way of which an articulation angle between the longitudinal axes of the traders and of the vehicle can be detected; and a simulation computer, in which a trajectory of at least one reference point of the trailer can be calculated from the wheel steering angle and/or the articulation angle; and a display device, by way of which the camera image can be represented; wherein the trajectory of the reference point of the trailer calculated by way of the simulation computer can be superimposed on the camera image.
In GB 2 398 048 A the surroundings of a big rig are detected by way of a camera which indicates to the driver, on a touchscreen device, what kind of steering is required to reach a selected target position.
Moreover, DE 103 22 828 A1 relates to a control system for a big rig comprising a tractor unit and a trailer, wherein the tractor unit is equipped with an electronically actuatable drive train.
Known methods for assisting the driver in the maneuvering of a big rig generally focus only on one of the two challenges that exist when backing up a trailer, these being either the limited view or the complex transverse dynamics. In addition, the majority of existing methods have the drawback that the trailer must be equipped with an additional sensor system (such as cameras or the like), which results in increased manufacturing costs.

Method for controlling the driving of a big rig and drive control system


An optical imaging system generates an image of an object plane and includes a lens system which, in turn, includes a main objective and a reduction optical unit ahead of the main objective. The lens system is aligned along an optical axis and the reduction optical unit includes a first lens with a positive refractive power and a second lens with a negative refractive power. An object-side first main plane and an image-side second main plane are defined by the lens system. The optical imaging system defines an observation beam path which is guided through the lens system so that, in the first main plane and in the second main plane, the observation beam path is at a distance (B) from the optical axis. The first lens is of a first material having a first Abbe number and the second lens is of a second material having a second Abbe number, wherein the first Abbe number is greater than the second Abbe number.

U.S. Pat. Nos. 6,788,455 and 6,967,774 have disclosed a microscope for wide angle observation for ophthalmic surgery which, by way of selectively addable optical units, allows an image of the fundus to be generated. The microscope includes a lens system, which includes a main objective and lenses disposed ahead of the main objective.
A disadvantage of this microscope is that the imaging quality in the wide angle observation is not ideal. As a result of the small distance between the main objective and the object to be observed, very short focal lengths result for a wide angle optical unit that can be added to the beam path. The wide angle optical unit can be adapted to the microscope by means of a further reduction optical unit which can be introduced into the beam path; however, this is linked to the disadvantage of a reduced imaging quality.
In addition to the optical disadvantages, the optical imaging systems in accordance with U.S. Pat. Nos. 6,788,455 and 6,967,774 have a relatively long installation length. In order not to unnecessarily hinder the user, for example a surgeon, in his work with the optical imaging system on the object, for example a patient eye, a reduction optical unit should only have a short installation length and additionally be disposed as closely as possible to the main objective.


A delay-lock loop includes several delay lines, all but the first of which is composed of at least one variable delay unit that provides a fixed delay and a variable delay. The first delay line is composed of a plurality of fixed delay units, but no variable delay units. The remaining delay lines are each composed of different numbers of variable delay units to provide respective clock signals having different phases, but they do not include any of the fixed delay units. The first and a last delay line receive an input clock signal. Each of the remaining delay lines are coupled to an output of one of the fixed delay units depending on the number of variable delay units in the delay line so that the resulting clock signals have all been delayed the same number of fixed delay periods.

Periodic digital signals are commonly used in a variety of electronic devices. Probably the most common type of periodic digital signals are clock signals that are typically used to establish the timing of a digital signal or the timing at which an operation is performed on a digital signal. For example, data signals are typically coupled to and from memory devices, such as synchronous dynamic random access memory ("SDRAM") devices, in synchronism with a clock or data strobe signal. More specifically, read data signals are typically coupled from a memory device in synchronism with a read data strobe signal. The read data strobe signal typically has the same phase as the read data signals, and it is normally generated by the same memory device that is outputting the read data signals. Write data signals are typically latched into a memory device in synchronism with a write data strobe signal. The write data strobe signal should have a phase that is the quadrature of the write data signals so that a transition of the write data strobe signal occurs during a "data eye" occurring at the center of the period in which the write data signals are valid. The write strobe signal is typically generated by the memory controller from an internal clock signal that is derived from the system clock signal, and it is coupled to the memory device into which the data are being written. Unfortunately, the phase of the system clock signal is normally substantially the same as the phase of the write data signals. Therefore, it is necessary for the memory controller to generate the write data strobe signal as a quadrature signal having a phase that is 90-degrees relative to the phase of the internal clock signal. In other cases, a quadrature clock signal used for latching write data is generated in the memory device to which the data are being written. The quadrature clock signal is typically generated in the memory device from an internal clock signal that is also derived from the system clock signal.
Various techniques can be used and have been used by memory controllers and memory devices to generate a quadrature clock signal or write data strobe signal. If the frequency of the internal clock signal is fixed, a quadrature write strobe signal can be generated by a timing circuit that simply generates a transition of the write strobe signal a fixed time after a corresponding transition of the internal clock signal. However, synchronous memory devices are typically designed and sold to be operated over a wide range of clock frequencies. Therefore, it is generally not practical to use a fixed timing circuit to generate a write data strobe signal from the internal clock signal. Instead, a circuit that can adapt itself to an internal clock signal having a range of frequencies must be used.
Multi-phase clock signals are also required for applications other than for use as a write data strobe signal. For example, a "frequency doubler" circuit, which generates an output clock signal having twice the frequency of an input clock signal, can be implemented using an appropriate logic circuit that receives the input clock signal and quadrature versions of the input clock signal.
One conventional circuit that can generate multi-phase clock signals from an internal clock signal having a variable frequency is a delay-lock loop, such as the delay-lock loop 10 shown in FIG. 1. The delay-lock loop includes a tapped delay line 14 having four variable delay units ("VDUs") 16, 18, 20, 22 coupled in series with each other. Each of the VDUs 16–22 has an input, an output, and a control input "C". Each of the VDUs 16–22 couples a digital signal from its input I to its output with a delay corresponding to a delay control signal applied to its control input C. The input of the initial VDU 16 receives an internal clock signal iCLK. The outputs of all but the last VDU 22 is coupled to the input of the subsequent VDU 16–20. The output of each VDU 16–22 also forms a respective tap of the delay line 14 to provide four clock signals, CLK1–CLK4. As explained in greater detail below, the voltage-control provided by each of the VDUs 16–22 is composed of two components; a variable delay tv having a magnitude set by the control signal C and a fixed intrinsic delay ti, which is the minimum delay by which a signal can be coupled through the VDU. The delay D of each of the VDUs 16–22 is thus defined by the formula:D=DI+DV.The total delay DT of the delay line 14, i.e., the delay of the CLK4 signal relative to the iCLK signal, is thus given by the formula:DT=4DI+4DV.
The CLK4 signal generated at the output of the final VDU 22 is also applied to one of two inputs to a phase detector ("PD") 26. The other input of the phase detector 26 receives the same iCLK signal that is applied to the input of the VDU 16. In operation, the phase detector 26 generates an error signal "E" at its output that is indicative of the lead or lag phase error of the CLK4 signal relative to the iCLK signal. The error signal E is applied to a VDU control unit 28, which generates a control signal that is applied to the control terminal C of the VDUs 16–22. The control signal adjusts the delay of the VDUs 16–22 to minimize the error signal and hence the phase error between the iCLK signal and the CLK4 signal. Therefore, the delays of the VDUs 16–22 are automatically adjusted until the phase of the iCLK signal is substantially equal to the phase of the CLK4 signal.
The operation of the delay-lock loop 10 will further be explained with reference to FIG. 2. The iCLK signal shown in the upper waveform is coupled through the first VDU 16 to produce the CLK1 signal shown in the second waveform of FIG. 2. The transition of the iCLK signal that produces the corresponding transition of the CLK1 signal are circled and linked to each other by a line in FIG. 2. Similarly, the indicated transition of the CLK1 signal is coupled through the VDU 18 to produce the indicated transition of the CLK2 signal, the indicated transition of the CLK2 signal is coupled through the VDU 20 to produce the indicated transition of the CLK3 signal, and the indicated transition of the CLK3 signal is coupled through the final VDU 22 to produce the indicated transition of the CLK4 signal. As previously explained, the delays of the VDUs 16–22 are automatically adjusted so that the iCLK signal has substantially the same phase at the CLK4 signal, which can be seen by comparing the iCLK signal shown in the top waveform of FIG. 2 to the CLK4 signal shown in the bottom waveform. All of the VDUs 16–22 are substantially identical to each other and they receive the same control signal so that they each provide the same delay. As can be observed from FIG. 2, since there are four VDUs 16–22 that together delay the iCLK signal by 360 degrees, each of the VDUs 16–22 delay the digital signal applied to its input by 90 degrees. The CLK1 signal thus has a phase of 90 degrees relative to the iCLK signal, the CLK2 signal thus has a phase of 180 degrees relative to the iCLK signal, the CLK3 signal has a phase of 270 degrees relative to the iCLK signal, and the CLK4 signal has the same phase as the iCLK signal.
The delay-lock loop 10 shown in FIG. 1 performs well over a wide range of frequencies in many instances. However, as will be explained with reference to FIGS. 3A and 3B, its high frequency range is limited by the intrinsic delay DI of each of the VDUs 16–22. With reference to FIG. 3A, as previously explained, each transition of the CLK4 signal is delayed from the corresponding edge of the iCLK signal by a total delay DT that is equal to the sum of the voltage-controlled delay VT and the intrinsic delay IT. Each of these delays VT and VI are shown in FIG. 3A. The period P of the iCLK signal is equal to the total delay, i.e., 4DV+4DI, and the frequency of the iCLK signal is the reciprocal of its period P, i.e., 1/(4DV+4DI). For example, if 4DV is equal to 4 ns and 4DI is equal to 1 ns, the frequency of the iCLK signal is 200 MHz, i.e., 1/(5*10−9).
The delay lock loop 10 can continue to lock the CLK4 signal to the iCLK signal increases by simply reducing the magnitude of the voltage-controlled delay 4DV to reduce the total delay DT. However, as shown in FIG. 3B, as the frequency of the iCLK signal continues to increase, the voltage-controlled delay DV is eventually reduced to zero. At this point, the total delay DT can no longer be reduced because the intrinsic delay DI is fixed. The maximum frequency of the iCLK signal to which the CLK4 signal can be locked to using the delay-lock loop 10 is thus the reciprocal of 4DI. Using the above example in which the total intrinsic delay 4DI is 1 ns, the maximum frequency of the iCLK signal is 1 GHz.
The fixed intrinsic delay of delay lines used in conventional delay-lock loops can therefore severely limit the frequency range over which d loops can be used. There is therefore a need for a delay-lock loop having a frequency range that is not limited by the intrinsic delay of conventional delay lines.

Multi-phase clock signal generator and method having inherently unlimited frequency capability


It is an object of the present invention to provide a crystallized glass which has various properties required for employing the substrate for information recording medium of the next generation, and also has significantly low specific gravity; and a crystallized glass substrate for information recording medium. A crystallized glass containing, as a crystal phase, one or more selected from RAl2O4 and R2TiO4 (wherein R is one or more selected from Mg and Fe), the crystallized glass comprising the components of SiO2 of 50% to 70%, Al2O3 of 10% to 26%, TiO2 of 1 to 15%, MgO of 2.5% to 25%, FeO of 0% to 8%, and ZnO of 0% to less than 2%, expressed in terms of mass percentage on an oxide basis, wherein the value of (Al2O3+MgO)/SiO2 is 0.30 or more and 0.65 or less, and a specific gravity is less than 2.63.

1. Field of the Invention
The present invention relates to a crystallized glass which has significantly low specific gravity and high mechanical strength, and also has significantly smooth surface roughness after polishing. The present invention also relates to a crystallized glass substrate for information recording medium, which has physical properties required for substrate for information recording medium of the next generation.
The term "information recording medium" in the present invention means a magnetic recording medium which can be used in hard disks for various electronic devices.
2. Related Art
In recent years, large data files such as movie and audio files have been used in personal computers and various electronic devices, and thus information recording devices with larger capacity have been required. As a result, there has been a demand for higher recording density of information recording media year by year.
To contribute to satisfying this demand, a perpendicular magnetic recording system has been employed and mass production thereof has been advanced.
In the perpendicular magnetic recording system, heat resistance, surface smoothness, and mechanical strength of substrates are required to a level higher than that of conventional substrates. Young's modulus, flexural strength, and fracture toughness have become especially important evaluation points in mechanical strength, and an improvement in these properties is a problem to be solved.
It is also more important nowadays that specific gravity of a base material should be lowered so as to alleviate load placed on spindle motors or to prevent disks from being damaged when dropped.
Examples of the material used in substrates for information recording media include Al alloy, glass, and crystallized glass. Glass and crystallized glass are superior to Al alloys in view of higher Vickers hardness, Young's modulus, higher surface smoothness, and the like, and thus have often been employed in applications where dynamic use is envisaged.
Crystallized glass is also called glass ceramics and is a material obtained by heating glass to thereby precipitate crystals inside the glass, and is distinguished from amorphous solid. In the case of those produced by using glass as a starting material, those converted completely into crystals may be used as crystallized glass. Crystallized glass can be imparted with physical properties, which cannot be obtained by glass, by virtue of crystals dispersed inside the crystallized glass. Crystallized glass can impart characteristic values regarding mechanical strength such as Young's modulus or fracture toughness, etching resistance to an acidic or alkaline chemical solution, thermal properties such as thermal expansion coefficient, increase and disappearance (improvement in heat resistance) of glass transition temperature and the like, that cannot be realized by glass.
Similarly, crystallized glass can be imparted with physical properties which are different from those of ceramics obtained by sintering powders. Crystallized glass is produced by using glass as a starting material and precipitating crystals inside the glass, and is therefore free from vacancies as compared with ceramics, thus enabling formation of a dense structure.
While crystallized glass in current use is imparted with higher mechanical strength by virtue of crystals precipitated in a glass phase, the crystallized glass exhibits a difference in processing between precipitated crystals and glass phases or a difference in etching rate. Therefore, the crystallized glass currently being employed do not sufficiently satisfy requirements of surface roughness of Ra<2 {acute over (Å)}, which is required of next generation substrates.
Furthermore, since the glass is brittle, defects such as breakage of substrates originating at microcracks on a surface of substrates are likely to occur.
Particularly, with the substrates for information recording medium used for the next generation of hard disks, resistance to crack propagation originating from microcracks on the surface of substrates, i.e., fracture toughness, has become an especially important evaluation point since the rotational speed of magnetic disks tends to be higher along with higher recording density. Therefore, the substrates for information recording medium are required to have higher fracture toughness.
However, the glass substrates currently being employed do not easily satisfy such requirements. Thus it is necessary to subject the substrate to a secondary strengthening treatment, for example, long-term chemical strengthening step so as to improve fracture toughness.
In the production of a glass substrate or a crystallized glass substrate, a direct press process is employed to directly press molten glass for the purpose of producing a disk-shaped substrate at lower cost.
In a glass melting process, an arsenic or antimony component has hitherto been used as a clarifying agent so as to remove bubbles from the molten glass when melting the glass. However, use of the arsenic or antimony component has recently been restricted since these components may exert an adverse influence on human bodies and the environment.
Therefore, use of a substitute component of the arsenic or antimony component as a clarifying agent has been studied. However, there arises a problem that, when the other clarifying agent is used, reboil generates in glass due to impact during direct pressing, and bubbles remain inside the substrate after pressing.
Thus, in order to solve these problems, the present inventors have developed a novel crystallized glass substrate for information recording medium and a patent application has been filed previously (Japanese Patent Application No. 2010-051242). Although this crystallized glass substrate for information recording medium is excellent in mechanical strength and surface smoothness after polishing, a lower specific gravity is required for a substrate for information recording medium of the next generation.
Patent Document 1 discloses a substrate for information recording medium, composed of crystallized glass including a gahnite crystal phase. The substrate has high fracture toughness, but surface roughness after polishing does not satisfy the level required for the substrate for information recording medium of the next generation.
It is also impossible for the substrate for information recording medium to satisfy the production cost required by the market due to lower polishing rate because of excessively high surface hardness, and lower productivity because of requiring longer time for the polishing process.
It is also very difficult for the crystallized glass to control degree of crystallinity and grain size of precipitated crystal since crystals are likely to precipitate rapidly when the raw glass is crystallized through a heat treatment.
Patent Document 2 discloses a glass ceramic containing a spinel type compound as a crystal phase. However, the melting temperature of the glass in Examples thereof is in a high temperature range from 1,500° C. to 1,650° C., and also the highest crystallizing temperature is in a range from 950° C. to 1,000° C., therefore, resulting in poor mass productivity. In addition, surface roughness Ra of the resulting glass ceramic is 5.3 {acute over (Å)}, and thus fail to satisfy the desired surface properties.
[Patent Document 1]Japanese Unexamined Patent Application, Publication No. H07-300340
[Patent Document 2]Japanese Unexamined Patent Application, Publication No. H09-77531

Crystallized glass and crystallized glass substrate for information recording medium


A high-speed carry-lookahead binary adder is disclosed. The binary adder includes multiple rows of carry-lookahead circuits, a half-sum module, and a sum/carry module. A first carry-lookahead circuit row includes multiple four-bit group generate circuits and multiple four-bit group propagate circuits. Each of the four-bit group generate circuits produces a generate signal for a corresponding bit location. Each of the four-bit group propagate circuits produces a propagate signal for a corresponding bit location. The half-sum module is utilized to generate a half-sum signal. By utilizing the half-sum signal, the generate signals, and the propagate signals, the sum/carry module generates sum signals and a carry signal.

1. Technical Field
The present invention relates to an apparatus for data processing in general, and in particular to a binary adder. Still more particularly, the present invention relates to a high-speed carry-lookahead binary adder.
2. Description of the Prior Art
Binary adders having a carry-lookahead are well known in the art. This type of binary adder is able to add two multiple-bit binary numbers while simultaneously computing a carry signal for each bit.
In order to compute the sum of two multiple-bit binary numbers A and B, a generate signal and a propagate signal are initially produced at each bit location. The equation for a generate signal G(i) is: G(i)=A(i)B(i), and the equation for a propagate signal P(i) is: P(i)=A(i)B(i)+A(i)B(i) or A(i)xB(i), where i denotes a bit location within the binary numbers and bit 0 is the most significant bit. These generate signals and propagate signals are then utilized to produce a carry signal for each bit. The generalized equation for a carry signal C(i) is: C(i)=G(i)+P(i) G(i+1)+P(i) P(i+1) G(i+2)+P(i) P(i+1) P(i+2) G(i+3)+. . . , etc.
Due to practical limitations such as fan-in, most carry-lookahead binary adders utilize several rows (or levels) of carry-lookahead circuits to produce carry signals while producing generate signals and propagate signals at each row. A row is commonly referred to a group or groups of circuits, the results of which are required by a subsequent row of circuits for further processing. For example, in a typical 64-bit carry-lookahead adder, groups of generate signals (G) and propagate signals (P) must first be produced in the first row for each bit. Then, a 4-bit group generate signal (G4) and a 4-bit group propagate signal (P4) are then produced at the second level for each group of four bits. The equation for a 4-bit group generate signal (G4) is: G4(i)=G(i)+P(i) G(i+1)+P(i) P(i+1) G(i+2)+P(i) P(i+1) P(i+2) G(i+3); and the equation for a 4-bit group propagate signal (P4) is: P4(i)=P(i) P(i+1) P(i+2) P(i+3).
Subsequently, a 16-bit group generate signal (G16) and a 16-bit group propagate signal (P16) are produced at the third level for each group of four 4-bit group generate signals (G4). The equation for a 16-bit group generate signal (G16) is: G16(i)=G4(i)+P4(i) G4(i+4)+P4(i) P4(i+4) G4(i+8)+P4(i) P4(i+4) P4(i+8) G4(i+12); and the equation for a 16-bit group propagate signal (P16) is: P16(i)=P4(i) P4(i+4) P4(i+8) P4(i+12).
The carry signal equations are then given as follows:
C(56)=G4(56)+P4(56) G4(60); PA0 C(52)=G4(52)+P4(52) G4(56)+P4(52) P4(56) G4(60); PA0 C(48)=G16(48)=G4(48)+P4(48) G4(52)+P4(48) P4(52) G4(56)+P4(48) P4(52) P4(56) G4(60); PA0 C(32)=G16(32)+P16(32) G16(48); PA0 C(16)=G16(16)+P16(16) G16(32)+P16(16) P16(32) G16(48); and PA0 C(0)=C.sub.OUT =G16(0)+P16(0) G16(16)+P(0) P16(16) G16(32)+P(0) P16(16) P16(32) G16(48).
As shown, a four-transistor stack is required within each carry-lookahead circuit to generate the last term of the carry equation, P.sub.i P.sub.i+1 P.sub.i+2 G.sub.i+3, and a three-transistor stack is required to generate the next-to-last term of the carry equation, P.sub.i P.sub.i+1 G.sub.i+2. Stacking transistors in this manner increases the delay and decreases the overall performance of the binary adder. Consequently, it would be desirable to provide an improved method for a binary adder to generate group propagate signals and group generate signals with minimal transistor-stacking such that the speed of the binary adder will be increased.

International Business Machines Corporation


A coupling disk comprises a control pawl mounted swivably about a swivel axis for swiveling from a resting position into a engagement position in which the coupling disk is coupled to a functional part of the belt retractor. The control pawl has a mount which is configured yielding transversely to the swivel axis. The control disk comprises an abutment on which the control pawl is supported when the mount yields.

Conventional coupling disks for a belt retractor comprise a control pawl which is swivably mounted for swiveling from a resting position into a engagement position in which the coupling disk is coupled to a functional part of the belt retractor.
A coupling disk of this type is part of a latching mechanism with which the belt reel of the belt retractor, on which the belt webbing is coiled, can be blocked by vehicle-sensitive or belt webbing-sensitive means against rotation in the uncoiling direction. The latching mechanism of such a belt retractor is known, this being the reason why it is only briefly mentioned in the following.
The coupling disk of the latching mechanism is connected non-rotatably to the belt reel. When the latching mechanism is activated in a vehicle-sensitive manner, i.e. by exceeding a predetermined acceleration or deceleration of the vehicle, or in a belt webbing sensitive manner, i.e. by exceeding a predetermined rotational acceleration of the belt reel due to tensile forces acting in the belt webbing, the control pawl is swiveled from its resting position into the engagement position so that the belt reel is coupled non-rotatably to a control lever or a similar functional part which on rotation of the belt reel in the uncoiling direction activates a load-bearing blocking pawl and thus causes blocking of the belt reel. The belt reel is then blocked in the uncoiling direction.
When the control pawl is in its engagement position, it transmits the forces necessary for blocking the belt reel, from the belt reel via the coupling disk to the functional part of the belt retractor. To prevent these forces from having to be regularly handled by the control pawl mount, requiring the mount to be correspondingly dimensioned, a stop is formed on the coupling disk which supports the control pawl in the engagement position such that the mount is relieved of loading to a major extent. If, however, the control pawl engages the functional part of the belt retractor assigned thereto before it is fully swiveled into its engagement position, more particularly in clashing of its tip and a tooth tip of the functional part, the stop on the coupling disk remains useless, and the entirety of the force transmitted by the control pawl comes to effect on the mount. This is why in the case of conventional coupling disks the mount for the control pawl needs to be over-dimensioned as compared to the usual operating loads so that the mount also stands up to the loads which are transmitted when the control pawl is not supported by the assigned raised face on the coupling disk. This results in high friction and high weight.


A base drawer which has been modified to allow non-permanent attachment of an extender to increase the vertical dimension of the drawer. Additional extenders can be stacked one on top of the other, in order to increase the vertical dimension of the drawer to any height desired. In one embodiment, the base drawer has three receptacles along the top edge of its two side walls, and each extender has three matching locking prongs along the lower edge of its two side walls as well as three receptacles along the upper edge of each side wall which allow extenders to be stacked one on top of the other. When one or more extenders are attached to a base drawer (i.e., receptacles and prongs are interlocked), the receptacles and prongs on each side of the resulting stackable drawer assembly are in line.

This invention relates to a drawer for a medication dispensing cart; such as, the medication dispensing cart claimed in U.S. patent application Ser. No. 07/662,750 which is incorporated by reference herein. Because of their open construction and use of a guide rail system, carts like these are able to house drawers of various vertical dimensions. Such versatility is especially important in the medication dispensing industry because there are numerous medication dispensing systems on the market which necessarily require storage drawers of varying heights.
Medication dispensing carts, like those disclosed in the previous reference, are used extensively in extended care facilities (i.e., nursing homes) and in general and acute hospitals. These carts are typically pushed from one patient's room to another and contain such things as patient medication and equipment for checking a patient's vital signs. Because different institutions, and in fact different wings within the same institution, can have different patient requirements and administrative needs, there is a demand for various configurations of such dispensing carts. In response to this demand, a wide variety of such dispensing carts have been introduced into the market. Such facilities typically provide health care to a diverse patient population with a wide variety of medical needs. Such a patient population necessitates maintaining the availability of a wide spectrum of medication and equipment in order to provide for day-to-day patient requirements.
In response to this spectrum of medical needs, the industry has in the past and continues today to provide customers with the flexibility to choose, for any given cart configuration, drawers with different vertical dimensions. Thus, each dispensing cart can be tailored to each individual customer's requirements.
Until the present invention, all such drawers had permanent vertical dimensions which required each manufacturer to be able to produce a wide variety of such drawers, with the manufacturer, or distributor, necessarily having to keep an inventory of each variety (i.e., various vertical dimensions) or else risk not having a requested drawer on hand. In addition, if a customer wished to change the vertical dimension of any drawer they were using, each such drawer would have to be replaced. Because they typically do not stock such replacement drawers, customers would be forced to wait until the new drawer was shipped and received before their needs could be satisfied.


A system and method for increasing the number of entities that can be serviced by a file server. The file server includes a plurality of server session sockets (SSSs), and means for assigning an entity identification number and one of the plurality of SSSs to a request from one of the number of entities, wherein each SSS can support a plurality of entities.

In the computing industry, it is quite common to transfer data and commands between a plurality of data processing devices, such as computers, printers, displays, terminals, and other network resources. Interconnection of computers and other peripheral devices principally developed in the early 1970's with the advent of computer networking systems which permitted the distribution of access to computing resources beyond the immediate proximity of a mainframe computer.
Recently, "local area networks" (LANs) have been developed which allow transfer of data between a localized set of computing and peripheral devices, typically in the same geographical area such as one building or a plurality of buildings closely situated together. Examples of such LANs may be found in U.S. Pat. Nos. 4,063,220, 4,661,902, and 4,689,786.
In the APPLETALK (R) (a trademark of Apple Computer, Inc.) network system, each "node" or computer, printer, peripheral, and other network resources share resources with a file server. The file server includes three main APPLETALK protocols called the APPLETALK Filing Protocol (AFP), APPLETALK Session Protocol (ASP), and the operating system of the file server includes the APPLETALK Transaction Protocol (ATP). The AFP is a protocol dealing with issues that are file system related. The AFP uses the ASP to receive file system requests from network entities and to send responses back to the entities. The request and responses may be partitioned into smaller data packets and the ASP uses the ATP to send and receive these data packets over the network.
The ASP is a protocol for maintaining network sessions between the file server and the network entities. A session is opened once an entity establishes communication with the server. The ASP keeps information about the entity in a session object
In the APPLETALK network system, each entity is assigned a unique 8-bit identifier which allowed the entity to filter out transmissions directed to other entities. Since the 8 bit identifier, or entity ID, was 8 bits in length, the number of entities or computers and peripherals and other network resources in the LAN was limited to 256 (this number is less the values where all the bits are set and all of the bits are clear, which are reserved). This limits the utility of such LANs, since an expansion beyond the 256 node limit required the connection of additional hardware to the system, such as another file server, for example. This results in an increase of the complexity of the local area network, as well as an increase in its cost.
U.S. Pat. No. 5,150,464, entitled "Local Area Network Device Start Up Process" and U.S. Pat. No. 5,150,464, entitled "Network Device Location" are both directed to systems for extending the number of entities a network can support. Even though these systems operate effectively for their intended purpose, they are both directed to extending the use of a network by adding routers and allowing the network to be connected to other network systems. What is needed therefore is a system and method in which more users can be served at one time by one file server on such a network. The system must be easily implemented in an existing network system. In addition, the system should easily support use by the networks. The present invention addresses such a need.

Method and system for providing an additional identifier for sessions in a file server