Described herein is a device that includes at least one radio frequency transmitter; at least one radio frequency receiver; a copy block configurable to output a digital representation of a currently transmitted signal and a model having a representation of at least analog circuitry of the at least one radio frequency transmitter and analog circuitry of the at least one radio frequency receiver, as well as possibly one or more antennas. The model generates, in response to the digital representation of the currently transmitted signal, a self-interference compensation signal to compensate, in the digital domain, a signal that is received simultaneously with the currently transmitted signal. Also described are corresponding apparatus, methods, computer program instructions stored in a memory medium, and an integrated circuit embodiment.

Several abbreviations that are found in the ensuing text and/or in the drawing Figures are defined as follows:
BB base band
DFE digital front-end
FE front-end
HW hardware
IC integrated circuit
LUT look up table
MRC multiradio controller
RF radio frequency
RX receiver
SIC self-interference cancellation
TX transmitter
In practice any transmitted signal can couple into a receiver through signal path parasitics such as, but not limited to, imperfect isolation between antennas and/or the use of two or more signal branches. Depending on the coupling level the interfering TX signal can desensitize a simultaneously operating receiver, such as in full duplex system or in the case of inter-system operation (e.g., two separate radio transceivers that operate simultaneously within one device), and totally degrade or at least significantly impair the operation of the receiver. This problem is made worse by the current trend towards increased chipset integration levels, where more circuits and circuit sub-systems are integrated into one IC or a few closely adjacent ICs.
One potential technique to alleviate this problem is to use a portion of the transmitted signal in the analog domain, such as at the output of a TX power amplifier, in order to cancel the self-interference component in the received signal. This approach requires summing the distorted RX signal with the portion of the TX signal, which in turn requires coupling the TX signal to the summing function so as to have the proper phase and amplitude. However, since the coupled TX signal manipulation is performed at least partially in analog domain, the accuracy and power consumption are not optimal, and in practice can be difficult to implement.
Reference may be had, for example, to U.S. Pat. No. 6,996,164 B1, Self-Interference Removal Using Converted Compensation in a Relayed Communication System, Blount et al., which describes a receiver section of a relayed communication system. A method is described for removal of self-interference that includes modeling downconversion imperfections in an imperfectly downconverted signal from a receiver downconverter. The receiver downconverter is in the receiver section that receives both an intended signal and a self-generated signal from a local associated transmitter that forms a received relayed composite signal. The method compensates for the downconversion imperfections in the received relayed composite signal to produce a compensated composite signal, and cancels self-generated signal portions from the compensated composite signal to provide an output signal for demodulation. The receiver downconverter model imperfections include at least one of quadrature phase offset, quadrature d.c. imbalance, and quadrature amplitude imbalance.

Analog signal path modeling for self-interference cancellation


A probe for generating a signal indicative of a quantitative measurement of the size of a surface defect, comprising a magnetic field generator for inducing currents in the surface, and a perturbation current sensor arrangement positioned relative to the field to give an output providing the quantitative measure.

One known non-destructive technique for testing the presence of cracks is alternating current potential drop (ACPD) testing, In which an alternating current is induced in the surface of a material to be tested and the interaction of the current with a defect is detected by a sensor. One type of eddy current testing system is described in British Patent GB 2012965B (U.S. Pat. No. 4,266,185), in which a pair of spaced contacting electrodes are engaged with an electrically conductive surface, and an alternating current is passed through the surface between the electrodes. A further pair of spaced apart pick up electrodes are used to measure a potential difference between two points on the surface. When a crack lies between the two points, the potential difference is higher since the current flows down one side of the crack and up the other; in either case, the distance traversed by the current is greater than the shortest distance between the two points. The voltage drop between the two points therefore provides a measure of the crack dimensions, as well as an indication of the presence of a crack.
A different type of probe is disclosed in GB 2225115A and corresponding U.S. Pat. No. 5,019,777. This probe avoids electrical contact with the surface and is therefore more reliable, and usable in underwater environments. In this proposal, there is provided a probe head which comprises a number of different sensors. The probe head comprises a solenoid coil which is fed with an alternating current, and a number of sensor coils. The solenoid coil induces eddy currents in the surface of a material to be tested, when brought into close proximity thereto. The sensor coils fall into two types. A first type comprises a coil wound round an axis parallel to the solenoid coil; these are referred to as "absolute" or "lateral" coils. The eddy currents flowing in the surface of the material induce a current in the lateral coils. The system of excitation (solenoid) coil, surface to be measured and lateral coil thus act as, respectively, the primary winding, core and secondary winding of a transformer and the magnitude of the voltage induced across the ends of the lateral coil varies with the resistance of the surface, and hence with the physical dimensions of any crack present. The output of such a coil can therefore provide a quantitative indicator of the depth of the crack In the surface. It may also be employed to measure the "lift-off" or separation between the probe and the surface as a function of the measured signal phase. However, because it is aligned with the solenoid, there is generally some direct induction from the solenoid, which can lead to inaccuracies. Also, the large dimensions of the lateral coil make it insensitive to the exact position of the crack, and consequently it is unsuitable on its own for determining the crack location and exact crack length.
For this purpose, a second type of sensor is employed comprising an elongate coil provided approximately coplanar with the surface to be tested, and consequently having an axis normal thereto (and to the axis of the solenoid). This coil is referred to as a "current perturbation coil". The current perturbation coil runs substantially the whole length of the solenoid, with its long axis aligned therewith, and is consequently symmetrically mounted about the centre, lengthwise, of the solenoid. Because its axis is normal to that of the solenoid, there is no substantial crosstalk from the excitation field and so the output is usually zero.
As will be discussed in greater detail below, the currents flowing in the surface of the material under test induce a current and voltage signal in a coil lying (or having a component lying) in a plane parallel to the surface. In the symmetrically mounted current perturbation coil of U.S. Pat. No. 5,019,777, when a symmetrical surface (either including or not including a flaw or crack) lies underneath the whole length of the magnetic field generated by the probe, the net signal output from the current perturbation coil is zero. However, if an end of a crack or flaw (or a change of depth) is present within the magnetic field of the probe, the current perturbation coil produces an output signal. Thus, the current perturbation coil produces a signal when either end of a crack or flaw is encountered, but not otherwise.
As will be discussed below, we have shown that the currents induced in the surface of the material rotate about centres underlying the ends of the solenoid, in opposite senses. At the centre of the solenoid, where the two contra-rotating currents meet, the current density is higher than that under the ends of the solenoid and beyond. There is thus a current gradient, having a maximum under the centre of the solenoid falling off towards the ends. For a very long solenoid, the current density may be constant over some regions, but there will be a gradient towards each end.
If a crack is present in the surface beneath the solenoid, as discussed above the current will journey down one side of the crack and up the other, and the associated material resistance leads to a voltage drop across the sides of the crack. However, we have realised that since the magnetic field, and hence current, varies along the length of the solenoid, where the crack is aligned with the solenoid axis the voltage drop caused will vary along the length of the crack, rising to a maximum under the centre of the solenoid. This voltage variation along the crack leads to local perturbation currents.
The perturbation coil used in the prior art is arranged symmetrically about the centre of the solenoid, so that the rise in potential difference along the crack underlying one half of the coil is matched by the fall in potential difference along the crack underlying the other half of the coil so that the generated perturbation currents are symmetrical and no net voltage across the coil is thereby generated, except when one end of the crack passes under the sensing coil. When this occurs, the voltage rise in one part of the crack is no longer compensated by a corresponding voltage fall along the other, so that there Is a net potential difference along the part of the crack underlying the perturbation coil, and hence a net perturbation current and a voltage is consequently generated in the perturbation coil.
Thus, in use, as the probe is moved over a surface, when one end of a crack is reached a pulse output voltage is produced by the perturbation coil, marking the start of the crack. As the probe moves along the crack, a signal indicating the crack depth is derived from the lateral coil. When the other end of the crack is reached, a further pulse is generated by the perturbation coil. By logging the outputs of the two coils, the start and end points of the crack, and hence its length, together with its depth may be accurately measured.

Eddy current probe system and method for determining the midpoint and depth of a discontinuity


A system for dynamic stabilization of the spine includes a bone engaging fastener configured to be anchored in a vertebra and a deflectable element mounted on the fastener. The deflectable element or bumper is configured and arranged to contact a portion of an adjacent vertebra, such as the facet, during extension of the spine, while offering no resistance during flexion. In certain embodiments, a cable may be fastened to the bone engaging fastener and arranged to contact a portion of the adjacent vertebra, such as the spinous process, during flexion of the spine. In one surgical technique of the invention, a contralateral approach is used to introduce the bone engaging fastener through the deflectable element and into the vertebra.

The present invention relates to spinal implants and stabilization systems. More particularly, the invention concerns a dynamic stabilization system that is disposed in between adjacent vertebrae.
In the past, the principal protocol for the treatment of the spine has been rigid fixation combined with fusion of the affected vertebral body or intervertebral disc. Arthrodesis, as this approach is known, has been achieved with a variety of rigid fixation elements, such as spinal rods or plates that are rigidly fixed to a vertebra using bone screws, bone bolts and spinal hooks. However, spinal fusion has been recognized to have limitations in the treatment of disc degeneration, especially in the earlier stages of the degeneration where it may be unnecessary to eliminate motion of the spinal motion segments.
Clinical studies suggest that cells of the intervertebral disc respond favorably to reduced (but not eliminated) mechanical loading through deposition of extracellular matrix proteins (collagen, proteoglycan, fibronectin, etc.) into the disc space. In some cases, a degenerated disc may simply involve a mechanically overloaded and hypermobile segment that can be repaired by reversing the mechanically damaging load environment. For instance, clinical experiences with dynamic stabilization systems suggest that the disc becomes increasingly hydrated over time, as judged by MRI scanning.
Spinal instability is a recognized effect of degenerative disc disease. In contrast to arthrodesis, arthroplasty is a protocol that contemplates restoring segmental spinal motion while treating the degenerative condition. Arthroplasty has been successfully used in the treatment of degenerative conditions of the hip and knee. In recent years, efforts have been made to implement arthroplasty in the spine, and most particularly in the intervertebral space. Intradiscal arthroplasty is now clinically available in the form of articulating prosthetic discs and polymeric disc nucleus replacements. With the availability of viable intradiscal arthroplasty devices, interest has grown in providing some means for dynamic spinal stabilization—i.e., stabilization that still permits some degree of mobility between spinal segments.
Drawing from the approaches developed for intradiscal arthroplasty, efforts have made to develop an extradiscal arthroplasty. These systems offer the advantage of "soft stabilization" that limit, rather than eliminate, spinal segment motion. Current theories suggest that preventing movement of the spinal segments may not be a significant factor in clinical success of spinal stabilization systems. Instead, these theories focus on creating a normal loading pattern for the spine as a primary vehicle for successful spinal instrumentation. Thus, the goals for dynamic stabilization has been to restrict movement of the spine to a zone or range where normal or near normal loading of the spinal segments can occur. At the same time, dynamic stabilization techniques have sought to prevent the spine from adopting a position or orientation where abnormal loading of the spine can occur. An acceptable outcome of dynamic stabilization is to make the instrumented spinal level more flexible than rigid (which would occur with fusion), but less flexible than normal.
One approach to achieve these goals for dynamic stabilization utilizes the spinous process. Thus, in one system, flexible "ligament" are engaged around the spinous process of adjacent vertebrae. Another form of flexible "ligament" is attached to the spinous process by way of small screws. In yet another approach, a polymeric spacer is held in place between the adjacent spinous processes. One system utilizes a coil spring that spans several vertebrae and that is anchored to the lamina of the end vertebrae. In one version, a rod extends through part of the coil spring to control rotation.
A similar construct employs a bearing cushion fixed between the spinous processes of adjacent vertebrae, as depicted in FIG. 1. This cushion 1 includes a U-shaped member having opposite brackets 2 for engagement to the spinous processes SP and separated by a flexible central portion 3. In certain embodiments, a cushion element 4 is disposed between the brackets 2 to limit the movement of the brackets, and therefore the adjacent vertebrae, towards each other. Details of this bearing cushion can be discerned from U.S. Pat. No. 5,645,599, the disclosure of which is incorporated by reference herein. As with the ligament-type systems, this bearing cushion resists movement of the adjacent vertebrae in flexion as well as extension. The addition of the cushion element increases the resistance in extension.
In another approach, resistance to flexion is eliminated, with the damping effect experienced only during extension. In this system, an insert 5 is held to the spinous process of a vertebra by a band or cable 7 encircling the spinous process. The insert 5 includes lips or wings 6 that contact each other when the anterior aspect of the vertebrae move together in extension. Details of this system are found in U.S. Pat. No. 5,011,484, the disclosure of which is incorporated herein by reference.
Some dynamic stabilization systems have relied upon fixation to the pedicle of the vertebrae. In these types of systems, a pedicle screw is threaded into the pedicle of adjacent vertebrae. A member spans between the heads of the pedicle screws to limit the movement of the spinal segments. In one device, known as the Graf Ligament, a non-elastic band is wrapped around pedicle screw anchors. The non-elastic bands lock the spinal segment into lordosis, while permitting minimal rotation movements of the spine.
Another system utilizing pedicle screws, provided by Zimmer, Inc. as the Dynesys System, incorporates a polymeric cylinder between the bone anchors. The Dynesys System permits, but limits, relative motion between adjacent vertebrae. An apparatus known as the FASS System essentially integrates features from the Graf and Dynesys systems.
The DSS System employs still another approach by including a spring element connected to pedicle screws. The spring element is contained within a polyurethane tube to prevent tissue ingrowth. Finally, some systems utilize a rigid member, such as a spinal plate, spanning between vertebrae. The flexible stabilization feature is incorporated into the interface between the pedicle screw and the rigid member, such as through a flexible washer or a spherical screw-plate interface.
There remains a need for a dynamic stabilization system that efficiently permits dynamic movement of the spinal motion segments while restricting the range of this movement.

Dynamic stabilization system for the spine


A ball-and-socket joint has a race with bearing balls interposed between the head and the socket of the joint. The race is secured to the head. In use as a prosthetic hip joint, the formation of metallic debris is reduced or completely eliminated thus eliminating or at least reducing the occurrence of the need for corrective surgery. The hip joint is of an unconstrained type which often enables correction of an accidental dislocation of the joint without surgery.

1. Field of the Invention
The invention relates to ball-and-socket joints and in particular to prosthetic joints to be used as implanted hip joints.
2. Description of the Prior Art
Many kinds of prosthetic ball-and-socket bearings for artificial joint to be implanted in human body are known in the art. Most of the presently used joints of this type use a frictional engagement between the ball portion or head of the joint and the socket. Examples of such known joints include those described in U.S. Pat. No. 4,380,090 issued Apr. 19, 1983 (Ramos) where an artificial hip joint has a bearing insert registrable with the first cavity, and a second cavity, having an annular bearing. U.S. Pat. No. 4,801,301 issued Jan. 31, 1989 discloses a prosthetic ball-and-socket joint having a bearing member surrounding a portion of the ball portion or head and rotatable within a spherical cavity. U.S. Pat. No. 5,507,818 issued Apr. 16, 1996 (McLaughlin) discloses a multipolar endoprosthesis including multiple wedge shaped, cylindrical components for adapting the position of the head of the joint. The joint disclosed in U.S. Pat. No. 5,549,697 issued Aug. 27, 1996 (Caldarise) shows a dampening mechanism absorbing some of the loading forces communicated to the acetabular cavity. U.S. Pat. No. 5,549,704 issued Aug. 27, 1996 to Sutter is concerned with a cap forming the ball portion of the joint and its attachment to a bone without a binder.
As mentioned above, the known joints use a frictional engagement, metal-to-metal or metal-to-plastic, between the head and the socket of the joint. Failure of a conventional total hip prosthesis is most often caused by aseptic loosening of either the femoral or acetabular components. Osteolysis (loss of bone) contributes significantly to loosening. When a total hip is loose, the patient's ambulation is dramatically reduced secondary to pain. The patient must undergo revision surgery. Conventional total hip arthroplasty comprises a metal femoral head articulating with a plastic acetabular liner. Wear particles from the ultra high molecular weight polyethylene (UHMWPE) have been implicated in causing osteolysis, loosening and premature failure of total hip joints. As a result, a renewed interest exists in "metal on metal" articulations that do not contain plastic. "Metal on metal" designs have been around since the early seventies, but it is not until recently that there has been renewed scientific interest. With traditional "metal on metal" designs, a metal ball portion articulates with a spherical metal liner. This is a crude "bearing" surface that does in fact produce metallic debris. Metallic debris also contributes to inflammatory tissue responses, probable loosening and thus premature failure and the need for revision surgery.
The above disadvantages have been recognized and mentioned in U.S. Pat. No. 5,556,434 issued Sep. 17, 1996 (Epstein) wherein the three-axis movement emulating the action of a natural hip joint is provided by a universal assembly mounted on a series of roller bearings in a horizontal swivel. While this solution may reduce the formation of undesired debris, it is very complex in structure and requires special bearings having the desired strength while providing a small enough size for accommodation of the entire mechanism within the prosthetic joint structure. Even more important, the joint is inevitably of a constrained type. In other words, the dislocation of the prosthetic joint upon an accident which would merely dislocate the joint cannot occur. As a result, complicated fractures often occur at the femoral or acetabular end, or both, of the implanted joint. These require complex surgical corrections. A mere dislocation of the joint would be much more desirable.
Another known hip joint utilizing a set of bearing balls is described in U.S. Pat. No. 5,092,898 to Bekki et al. In a first group of embodiments, a complex artificial joint head portion is shown having an inner head and an outer head and a rolling ball insert therebetween. The outer surface of the outer head is polished to a mirror for engaging the acetabular roof. These embodiments, when in use, combine a limited angle movement between the inner and outer heads effected by the rolling balls. However, on more substantial angles of movement, a frictional displacement between the outer head and acetabular roof is required. In a second group of embodiments, Bekki et al show a restrained joint where the head of the joint is held in the socket by a retainer ring or assembly which is fixedly secured to the socket, i.e. to the roof of the acetabulum. Thus, any accident which might normally result in a mere dislodgement of the joint would at least destroy the retainer ring and most likely at least a part of the acetabulum, not to mention the release of the race with the rolling balls.

Ball-and-socket joint, particularly a prosthetic hip joint


A flexible magnetic fastening apparatus with enhanced strength and reduced noise during use is provided. The magnetic fastening apparatus includes an upper fastener detachably coupled to a lower fastener. Each fastener in the upper and lower fasteners has a fabric layer that encapsulates a magnetic member. The magnetic member in each fastener has a positive magnetic pole at the bottom surface of the fabric layer and a negative magnetic pole at the top surface of the fabric layer. The negative magnetic pole of the magnetic member in the lower fastener attracts the positive magnetic pole of the magnetic member in the upper fastener, thereby coupling the bottom surface of the upper fastener to the top surface of the lower fastener.

The embodiments herein relate generally to fasteners. More specifically, embodiments of the invention are directed to a flexible magnetic fastening apparatus.
In today's world, there are many different types of fasteners used in clothing, bags, and backpacks to name a few. Snaps, buttons, zippers, and hook and loop fasteners have become the norm. Fashion will always have a place for many of these fasteners due to their appeal in the industry. Hook and loop fasteners have become a staple in many of today's products due to their lightweight nature and cost.
However, these fasteners have several limitations. In particular, hook and loop fasteners can wear out over time and are noisy when pulled apart from each other. In hunting and military applications, hook and loop fasteners have become a staple in clothing and gear such as cases and bags. In these applications, silence is crucial. In hunting, it could mean the difference between landing a trophy animal or not. In the military, it could be a matter of life or death. Other existing fasteners such as snaps, buttons, zippers and other fastening components similarly are limited due to their noise during use. Further, several of these fasteners are not efficiently operated such as in the case of zippers because the user has to align rows of teeth together to operate the slider. Other fasteners such as buttons are not durable because they frequently fall off the clothing, apparel or bag used.
As such, there is a need in the industry for a flexible magnetic fastening apparatus that addresses the limitations of the prior art, which provides a fastener with enhanced strength that reduces the amount of noise generated during use. There is a further need for the flexible magnetic fastening apparatus to engage and disengage with enhanced efficiency.


A socket and a printed circuit board for testing a semiconductor device packaged by a chip scaled package (CSP) method, and a semiconductor device testing method are provided. In order to test the semiconductor device packaged by a CSP method, the upper wall of the testing socket has a socket aperture formed to expose the pads of the semiconductor device to be tested to the outside of the testing socket. The testing socket may be mounted under the printed circuit board. The printed circuit board has a board aperture formed over the socket aperture. The pads of a semiconductor device are directly probed through both the socket aperture and the board aperture, so that the waveforms of a semiconductor device can be measured.

1. Field of the Invention
The present invention relates to semiconductor devices, and more particularly, to a socket and a printed circuit board for semiconductor devices, and a method of testing semiconductor devices.
2. Description of the Related Art
Recent semiconductor devices operate at a high frequency band of several hundreds of MHz. In this high frequency band, the influence of the parasitic components of a semiconductor device package upon the operation of semiconductor devices increases. The parasitic components are resistance, inductance, and capacitance. To reduce these parasitic components, a chip scaled package (CSP) has been introduced The CSP is smaller than conventional plastic packages, so that the influence of the parasitic components of the CSP upon the operation of a semiconductor device is reduced.
A conventional CSP will now be described referring to FIGS. 1 and 2. FIG. 1 is a top plan view of a semiconductor device packaged by a conventional chip scaled package (CSP) method, and FIG. 2 is a cross-sectional view of the semiconductor device of FIG. 1 taken along line 2-2xe2x80x2.
A semiconductor device 11 is covered by a chip surface protective film 22 formed of polyamide or the like. In such a semiconductor device 11 packaged by a CSP method, balls 13 are connected to pads 15 via beam leads 17. The pads 15 are disposed in an area 19 that runs along the center of the semiconductor device 11, and the device is also covered by a tape 28 or the like.
Generally, the semiconductor device 11 packaged by the CSP method is mounted on a test socket to be tested. FIG. 3 is a top plan view of a conventional test socket, and FIGS. 4 and 5 are cross-sectional views of the test socket of FIG. 3 taken along lines 4-4xe2x80x2 and 5-5xe2x80x2, respectively.
Referring to FIGS. 3, 4 and 5, a conventional test socket 30 includes outer sidewalls 31 for fixing a semiconductor device 44 to be tested, an upper wall 45 and a lower supporting member 47. Also, the conventional test socket 30 includes ball contact springs 32, formed through the upper wall 45, which individually contact balls 43 connected to pads 53 via beam leads (not shown).
However, the semiconductor device 44 packaged by a CSP method has the balls 13 and the beam leads 17 formed thereon, as shown in FIGS. 1 and 2. Thus, even when a certain portion of the package is uncovered, the chip surface of the semiconductor device 44 cannot be directly accessed because of the balls 13 and the beam leads 17. Therefore, in contrast with general plastic packages, it is impossible to directly measure signal waveforms from the chip surface of a semiconductor device at a frequency where the semiconductor device operates.
To solve the above problem, it is an object of the present invention to provide a test socket capable of directly detecting waveforms from the chip surface of a semiconductor device packaged by a chip scaled package (CSP) method.
It is another object of the present invention to provide a printed circuit board (PCB) at which a test socket capable of directly detecting waveforms from the chip surface of a semiconductor device packaged by a CSP method is installed.
It is still another object of the present invention to provide a method of testing a semiconductor device capable of directly detecting waveforms from the chip surface of a semiconductor device packaged by a CSP method.
Accordingly, to achieve the first object, the present invention provides a socket for testing a semiconductor device, the socket including outer sidewalls, an upper wall and a lower support member for fixing the semiconductor device. The socket also includes ball contact springs, formed through the upper wall, which contact corresponding balls connected to the corresponding pads of a semiconductor device to be tested, and a socket aperture formed through the upper wall to expose the pads of the semiconductor device to the outside of the testing socket.
To achieve the second object, the present invention provides a printed circuit board at which a socket for testing a semiconductor device packaged by a CSP method is installed. The printed circuit board includes a board aperture formed over the socket aperture of the testing socket to expose the pads of a semiconductor device. Preferably, the upper wall of the testing socket is attached to the bottom of the printed circuit board. More preferably, the size and location of the socket aperture of the test socket are similar to those of the board aperture of the printed circuit board to expose the pads of a semiconductor device.
To achieve the third object, the present invention provides a method of testing a semiconductor device packaged by a CSP method, by which waveforms can be directly detected from the surface of a semiconductor device chip. The method includes: forming a socket aperture in a testing socket on which a semiconductor device to be tested is mounted; mounting the semiconductor device on the testing socket so that the pads of the semiconductor device are exposed through the socket aperture; forming a board aperture in a printed circuit board; attaching the testing socket to the bottom of the printed circuit board so that the socket aperture faces upward and is aligned vertically with the board aperture, whereby the pads of the semiconductor device are exposed through the socket aperture and the board aperture when the testing socket has been installed at the printed circuit board; and testing the semiconductor device through the board aperture and the socket aperture.
In the above-described devices and method of testing a semiconductor device, according to the present invention, the waveforms on the chip surface of a semiconductor device packaged by a CSP method can be directly detected.

Socket and printed circuit board for semiconductor device, and method of testing semiconductor device


Method and arrangement for providing and controlling a gas turbine (1) at least one turbine (11, 20, 20′), at least one compressor (2, 5) driven by the turbine and a combustion chamber (16) arranged between the compressor and the turbine in the airflow path. The gas turbine includes devices (8) for direct measurement of the air mass flow at a position upstream of the combustion chamber in the airflow path, with the aim of regulating the quantity of fuel that is delivered to the combustion chamber (16) on the basis of the measured air mass flow.

The present invention relates to a gas turbine. The invention further relates to a method for controlling a gas turbine. The gas turbine includes at least one turbine, at least one compressor driven by the turbine and a combustion chamber arranged between the compressor and the turbine in the airflow path. The gas turbine is designed for compressing the gas in the compressor, heating the compressed gas in the combustion chamber and expansion of the heated gas in the turbine.
Gas turbines are used, for example, as engines for vehicles and aircraft, as prime movers for ships and for generating electricity in power stations. The present invention is primarily directed towards applications in which transient processes occur; that is to say, for dynamic applications. In such transient processes the load of the gas turbine varies relatively rapidly. One example of an application in which such transient processes are frequently performed is where the gas turbine is used to propel a vehicle or a vessel. These applications require acceleration and retardation on the part of the gas turbine. Still further, more stringent requirements for the low output of exhaust gas emissions call for precise control of the fuel supply even during transients.
In stationary operation the fuel supply is typically controlled by a feedback regulator reacting to the speed, pressure or temperature of the gas turbine. These quantities, however, are not stable in the case of rapid transients.
Traditionally, an air mass flow is calculated on the basis of other measurable quantities, such as gas generator speed or compressor pressure and the quantity of fuel delivered to the combustion chamber during transients is metered on the basis of the calculated air mass flow.
In many applications, and especially in the case of transient processes, great accuracy and speed are required. Such transients are furthermore usually associated with peak emissions since known solutions do not provide sufficiently rapid feedback control. It would therefore be desirable to achieve reduced exhaust emissions in the case of transients.

Gas turbine and a method for controlling a gas turbine


Disclosed is a novel polymeric compound poly(benzoic acid) which is a linear polymer consisting of the 1,4-phenylene linkages, each phenylene group having a carboxyl group. Poly(benzoic acid) can be prepared by hydrolyzing a poly(alkyl benzoate) in the presence of an acid or alkali. The thus obtained poly(benzoic acid) can be converted into a poly(p-phenylene) by the decarbonation reaction thereof in an organic solvent such as quinoline in the presence of metallic copper dust or a copper (II) compound such as copper (II) oxide and copper (II) carbonate hydroxide.

The present invention relates to a poly(benzoic acid), which is a novel compound not known in the prior art nor described in any literatures, a method for the preparation of a poly(benzoic acid) and a method for the preparation of a poly(p-phenylene) having electroconductivity, oxidation-reduction characteristic and excellent heat resistance and suitable as a polymeric electroconductive material and material of a heat-resistant polymer from the poly(benzoic acid).
Poly(p-phenylene) is a known polymeric material having good electroconductivity and excellent heat resistance. Despite these unique properties as an organic polymer, the industrial application field of poly(p-phenylene) is still not so wide because of the difficult problems that poly(p-phenylene) is an insoluble and infusible polymer so that no conventional method is applicable to the molding work of the polymer and that the molecular weight thereof cannot be high enough with a relatively irregular molecular structure not to give a reproducible quality.
A method for the preparation of a poly(p-phenylene) is disclosed in Journal of the American Chemical Society, volume 85, pages 454-458 (1963), according to which benzene is subjected to oxidative polymerization in the presence of aluminum chloride and copper (II) chloride. An alternative method is proposed in Synthetic Metals, volume 44, pages 107-110 (1992), in which benzene is electrolytically polymerized in fuming sulfuric acid to give a poly(p-phenylene). These methods, however, are practically defective since, in the former method, the poly(p-phenylene) is obtained in the form of a powder which is not susceptible to molding and, in the latter method, the polymer obtained has only a quit low degree of polymerization with consequently poor electric and mechanical properties although the polymer is obtained in the form of a film deposited on the surface of the electrode.
Besides, a method is proposed in Macromolecules, volume 21, pages 294-304 (1988), in which a poly(p-phenylene) is obtained in the form of a film through an intermediate having moldability. The polymer obtained by this method, however, does not consist of the 1,4-phenylene units alone but contains about 15% of the 1,2-phenylene units so that the electric properties thereof are not as desired.

Poly(benxoic acid), method for the preparation thereof and method for the preparation of poly(p-phenylene) from poly(benzoic acid)

Japan as represented by Director General of Agency of Industrial Science and Technology


An ATV drive shaft which can be produced at low costs is provided. In a drive shaft installed in an uneven terrain traversing, mounted type vehicle and adapted to transmit drive power to wheels through constant velocity joints J1 and J2 on the inboard and outboard sides, a double offset type constant velocity joint J2 is used on the inboard side and an undercut free type constant velocity joint J1 is used on the outboard side, and the track clearances of the constant velocity joints J1 and J2 are in the range of 20 μm-200 μm.

1. Field of the Invention
The present invention relates to an ATV (All Terrain Vehicle: an uneven terrain traversing, mounted type vehicle, also called four-wheeled buggy car) drive shaft and to an undercut free type constant velocity joint disposed on the outboard side of a drive shaft for a vehicle having no power steering.
2. Detailed Description of the Prior Art
As is known in the art, in automobiles having no power steering and various vehicles similar thereto, constant velocity joints capable of transmitting rotational power at constant velocity even when there is an angular or axial displacement between two shafts have been installed in a power transmission path for transmission of drive power from the engine to wheels. As an example of a vehicle having such power transmission path, a so-called ATV which is an uneven terrain traversing, four-wheeled or three-wheeled, mounted type vehicle, equipped with balloon tires and designed to freely traverse wastelands, sandy beaches and the like has come to be widely known.
The power transmission device for these various vehicles will be explained with said ATV used as a representative example. As conceptually shown in FIG. 6, the power from an engine 21 is outputted from the output shafts on the front and rear sides via a speed change mechanism in the interior and is inputted to differential gears 24 and 25 on the front and rear sides via power transmission means 22 and 23, such as chains or propeller shafts. And, the engine power inputted to the differential gears 24 and 25 is reduced in speed by the mechanism of the differential gears 24 and 25 and is converted to a rotational power orthogonal thereto, whereupon it is transmitted to the wheels 28 and 29 through left and right drive shafts 26 and 27. In the example shown in the same figure, constant velocity joints are used for joints A between the drive shaft 26 on the front side and the differential gear 24 and for joints B in the wheels 28. In addition, there are cases where constant velocity joints are used for joints C between the drive shaft 27 on the rear side and the differential gear 25 and for joints D in the wheels 29. Further, when propeller shafts are used as the power transmission means 22 and 23, there are cases where constant velocity joints are used for joints E and F between the propeller shafts and the output shafts of the engine (speed change mechanism) 21 and joints G and H in the differential gears 24 and 25.
FIG. 7 shows the drive shaft 26 on the front side. In order to allow the drive shaft 26 to make angular displacement and axial displacement following the movement of the wheel 28 during cornering, traversing uneven terrains or the like movement, a slide type constant velocity joint (a constant velocity joint allowing angular displacement and axial displacement between two shafts) 30 and a fixed type constant velocity joint (a constant velocity joint allowing angular displacement between two shafts) 31 are used in pair for joining the drive shaft 26. In the example shown in the same figure, one end (the inboard side) of the drive shaft 26 is joined to the differential gear 24 (at the joint A) through the slide type constant velocity joint (a double offset type constant velocity joint, hereinafter referred to as "DOJ") 30, while the other end (the outboard side) of the drive shaft 26 is joined to the wheel 28 (at the joint B) through a fixed type constant velocity joint (Rzeppa type constant velocity joint: ball fixed joint, hereinafter referred to as "BJ") 31.
Heretofore, as said DOJ and BJ for vehicles such as ATVs, those for passenger cars have been frequently converted to be used as such. And, in vehicles small in size and narrow in width, such as ATVs, it is suitable to use a drive shaft which is light-weight and compact and which has satisfactory operability. To meet such demand, Japanese Patent Laid-Open 2001-97063 which follows, for example, discloses the use of a double offset type constant velocity joint (DOJ) on the inboard side and an undercut free type constant velocity joint (hereinafter referred to as "UJ") on the outboard side, in a drive shaft for transmitting drive power to wheels through constant velocity joints on the inboard and outboard sides.
The UJ disposed on the outboard side of this drive shaft, basically, as shown in FIG. 8, comprises an outer joint member 12 with a spherical inner peripheral surface 12a formed with a plurality of track grooves 13, an inner joint member 14 with a spherical outer peripheral surface 14a formed with a plurality of track grooves 15, a plurality of torque transmitting balls 16 disposed in ball tracks formed by the opposed track grooves 13 and 15 of both joint members 12 and 14, and a cage 18 interposed between both joint members 12 and 14 and formed with a plurality of pockets 17 holding the torque transmitting balls 16.
And, it is stated in said Document that the track offset angle of the UJ is set at 5°-7° and that the cage offset amount of the UJ is set at 0, and that with a conventional UJ, the cage offset angle has been set at not less than 1°. That is, in this UJ, as shown in FIG. 8, the centers Oaa and Obb of track grooves 13 and 15 of the outer and inner joint members 12 and 14 are offset by an equal distance Laa to axially opposite sides with the joint center O used as a reference. A track offset angle φaa (an offset angle at the track grooves 13 and 15) consisting of ∠0aaQO (or ∠ObbQO) is set at 5°-7°. In this case, since the cage offset amount is 0, the Lcc in the figure is 0. Further, in the conventional UJs, the centers Occ and Odd of the inner and outer spherical surfaces 18a and 18b of the cage 18, respectively, are offset by an equal distance to the axially opposite sides with the joint center O used as a reference. A cage offset angle φcc (the offset angle of each of the spherical surfaces 18a and 18b of the cage 18) consisting of ∠OddQO (or ∠OccQO) is set at not less than 1°. In addition, in the following description, the sum of the track offset angle and the cage offset angle φcc will be referred to as the total offset angle (φaa shown in FIG. 8). Therefore, the track offset amount in FIG. 8 is an amount (Laa−Lcc) obtained by subtracting the cage offset amount Lcc from the total offset amount Laa.
Further, in a conventional UJ, in order to improve the function of a cage 18 to guide torque transmitting balls 16 and from the standpoint of attaching importance to the securement of constant velocity nature of the joint, the axial clearance δ between a pocket 17 of the cage 18 and the torque transmitting ball 16, that is, the value δ obtained by subtracting the diameter of the torque transmitting ball 16 from the axial width of the pocket 17 is set so that δ<0 (negative clearance) to give an interference between the pocket 17 and the torque transmitting ball 16, which has been common practice. In this case, when the axial clearance δ is small (excessively negative), the torque transmitting balls 16 can hardly roll on the ball tracks and in the pockets 17, a fact which is disadvantageous from the standpoint of rotational resistance when this type of joint transmits torque while taking a working angle; thus, adversely affecting steerability. In contrast, when the axial clearance δ is made large (positive clearance is made excessively large), the rollability of the torque transmitting balls 16 is enhanced to reduce the rotational resistance, but the guiding function of the cage 18 for the torque transmitting balls 16 is impaired to break constant velocity nature of this type of joint, leading to abnormal sound and a feeling of being caught during steering, and hence to a deterioration in steering feeling. In addition, Japanese Patent Laid-Open Nos. 2000-266071 and 2002-5186 specify the axial pocket clearance δ of a constant velocity joint installed in general automobiles including passenger cars, not a constant velocity joint installed in vehicles having no power steering represented by ATVs which are the subject of the invention.
Since car body weight restrictions for ATVs are severe, further weight reduction and size compaction are required of drive shafts therefor. Further, ATVs are small in size, narrow in width and high in height, so that constant velocity joint installed in the drive shaft has its normal working angle reaching as much as about twice that in passenger cars. For this reason, with passenger car specifications, there may be the danger of the operating stability of the constant velocity joint being impaired depending on usage conditions and the like. Further, with ATV constant velocity joints, about ½ of the durability (life) of passenger cars and the like is sufficient as considered from balance between market performance and the term of guarantee. Therefore, as considered on the basis of passenger car specifications as they are, there is a feeling of excessive quality. As to the rpm used, about half for passenger car specifications is sufficient as considered from balance with vehicle speed, and the same may be said. On the other hand, the same degree of strength including twist strength as that for passenger car specifications is required.

ATV drive shaft and constant velocity joint


A Hunting Bow Hanging apparatus attachable to a tree or post comprising an "L"-shaped bracket with a lag bolt permanently attached extending from one end of the "L"-shaped bracket and screwable secured to a tree. A square aluminum outer tube is attached to the other end of the "L"-shaped bracket and has holes drilled down its length to allow for adjustment of a square aluminum inner tube insertable therein which has holes drilled that correspond to the holes of the outer tube. A locking bolt and/or pin is insertable through the holes of the outer and inner tubes to allow for length adjustment and securing of the inner tube. A hunting bow mounting bracket is provided at the end of the inner extension tube for connecting the bow or any other article to the apparatus.

In order to successfully hunt, a bow hunter must sit extremely still for long periods of time waiting for prey to walk within range. Any movement of the bow hunter will startle the prey and spoil the hunt. Normally, when prey is within range the hunter must ready him or her self by retrieving the bow and getting into position. The present invention allows a hunter's bow to hang directly in front or to a side at all times in a ready position thereby reducing the movement of a hunter. The device is length adjustable so that the bow can be placed in a location that helps illuminate movement when the hunter must ready for the bow. The present device limits movement of the hunter as much as possible thereby resulting in a more successful hunting.
Numerous prior patents have been obtained for securing hunting bows, cameras, and steps as follows:
Kearful, U.S. Pat. No. 5,669,592 which discloses a camera support for supporting a camera which is threadably secured to a tree or post. This device is extremely useful for camera however it is unapplicable for use as a bow hanging apparatus as the present invention.
Oglesby, U.S. Pat. No. 5,482,241 which discloses an archery bow support attachable to a tree or post. This invention is extremely useful however the hanger support for the Oglesby device does not allow the hanging bow to be easily moved in direction if necessary.
Mahn, et al, U.S. Pat. No. 5,144,107 discloses an apparatus for supporting archery equipment. This device is useful for its stated purposes however it is not easily adapted for hanging numerous types of bows as the present invention and does not provide an inexpensive and easy to use device as the present invention.
Stinson, U.S. Pat. No. 5,076,522 discloses a detachable mount of arrow quivers. This device is useful for mounting arrow quivers however it is inapplicable for use as a bow hanging device as the present invention.
Melcher, U.S. Pat. No. 3,380,697 discloses portable steps for climbing trees or poles with a pivotal lag bolt attachment. This device is useful for attaching portable steps to a tree or post and utilizing a similar attachment means as the present invention. The Melcher device is not adjustable in length as the present invention and does not include a bow hanging attachment mechanism as the present invention which overcomes the problems that a bow hunter experiences when attempting to retrieve his/her weapon when an animal is near. The invention minimizes the movement of the hunter by providing a hanging means for a hunter's bow so that the hunter's bow is in a ready position thereby reducing the amount of movement the hunter must go through to ready the weapon.


An exercise machine for exercising the lower body, the upper body, or both simultaneously. The mechanism consists of a crank, a rocker, a connector link, and a stationary fourth link so arranged as to cause a portion of the connector link to travel about a closed curve resembling an ellipse, a tear drop shape, or any variation thereof. A flywheel and/or force resisting means may be added to provide inertial characteristics and drag resistance to the operator.

The prior art is replete with many categories of exercise machines designed to exercise all major muscle groups of the human body. The most popular machines provide motion similar to activities such as bicycling, skiing, walking or stepping. The popularity of these machines is due to the effective low impact form of exercise enabled, as well convenience and time saving advantages.
In reference to machines such as stationary bicycles and steppers which involve the lower body, and cause the operators feet to move under resistance along constrained arcuate paths, evolving bicycle and stepper machine designs continue to incorporate foot motion paths of arcuate forms which are circular by definition. With bicycle machines, the circular path is caused by the simple relationship of the distance between the foot pedal and the pedal crank shaft. This constancy of motion is artificial to the human body, and is not considered by the inventor to be optimum during exclusive use for long term muscular development and conditioning. Bicycle machines do however offer a continuous motion which is preferable in order to ensure machine usage.
In reference to stepper machines, the arcuate path that the foot platforms travel about is a simple function of the distance between the foot platform and the pivot point of the platform support member. The stop and go motion of conventional steppers, in conjunction with the somewhat linear foot path, is considered by the inventor to be less ergonomic than the four bar stepper design of the present invention.
If one studies the motion paths of human feet during an activity such as walking or running, it will readily be observed that they travel along paths more accurately described as teardrop shaped. Whereas in the case of hill or stair climbing, the motion of ones feet closely resembles an ellipse or oval. The present invention provides a means to satisfactorily produce either motion, teardrop or elliptical, and does so in an efficient and economical way.


A headwear apparatus for use in swimming is provided that has a generally hemispherically shaped swim cap portion with a forward section and a rearward section. The forward section has a forward terminal edge which is coupled to a goggle portion along the forward terminal edge. The goggle portion includes a left lens and a right lens that each have a front surface and an outer perimeter surface extending rearwardly from the front surface. The outer perimeter surface has an upper portion that is coupled to the forward terminal edge of the swim cap portion. The swim cap portion has a thickness defined by a top surface and a bottom surface, and the top surface of the forward section is in a planar relationship with the front surface of the lenses at the forward terminal edge. The swim cap portion has a rearwardly extending strap formed integrally with the cap portion.

Competitive swimming was included in the first modern Olympic Games in 1896 and has since continued as a competitive sport. Today competitive swimming events include not only the traditional races held in swimming pools, but also races in open water, such as the swimming legs of triathlons. In almost all modem competitive swimming events, the swimmer will wear conventional swimming goggles, such as those shown in FIG. 1 designated by numeral 110. Goggles are used to increase the swimmer's vision under water and to shield the swimmer's eyes from contaminants such as salt in the ocean, or chlorine in a swimming pool. The prior art goggles currently in use have a pair of lenses 112 which are coupled together by a nose bridge 114. The outer perimeter of the lenses is typically surrounded by a foam rubber padding ring which acts as a sealing material. This foam padding ring is placed against the eye-socket area of the swimmer. Extending rearwardly from the outside edges of the lenses is an elastic strap 116 which is placed around the swimmer's head to exert a force on the foam padding rings so that water is prevented from flowing into the spaces between the lenses and the swimmer's eyes.
The swimming goggles currently in use, however, suffer from several disadvantages. First, the swimming goggles leak when in use. This leakage allows water and contaminants to enter the spaces between the lenses and the swimmer's eyes. At some point during the competition, the swimmer may experience discomfort or impaired vision due to the water which has entered these spaces. Enough water may leak into these spaces to cause the swimmer to empty the goggles and reseal the lenses against the swimmer's face. This is disadvantageous in a competition because time is spent away from advancing towards the finish line.
Different materials have been employed for the padding rings of conventional goggles in an attempt to form a better seal between the lenses and the swimmer's face. These materials have improved the performance somewhat, but leakage problems remain. It has been found that the major point of leakage is along the upper margins of the padding rings. As best seen in FIG. 1, the prior art goggle lenses protrude outwardly from the swimmer's face. As the swimmer propels himself forwardly through the water, the protruding section of the lenses causes a turbulent flow of water around the lenses. This turbulence can exert forces on the goggles sufficient to cause the upper portions of the goggle lenses to rotate away from the swimmer's face. If the lenses so rotate, the seal between the padding rings and the swimmer's face will be at least partially broken, thus allowing water to leak into the areas between the lenses and the swimmer's face
Another method of discouraging leakage is to increase the force applied to the lenses with the elastic strap, in an attempt to overcome the forces caused by the turbulence discussed above. The force necessary to do so can result in discomfort to the swimmer as the goggles are forced inwardly against the eye and eye socket. Thus, developments in padding ring materials and elastic strap designs have not completely solved the problem of leakage.
Another disadvantage of prior art goggles is the increased drag caused by the protruding lenses of the goggles as the swimmer propels himself through the water. In competitive swimming events, every effort is made to reduce the drag caused by the swimmer and his equipment. Reduced drag results in improved hydrodynamics and can result in lower times to complete the event. Therefore, the protruding goggle lenses not only cause potential leakage problems, but also cause the swimmer to experience increased resistance as he travels through the water.
Also worn by the competitive swimmer is a swimming cap represented in FIG. 1 by the numeral 118. Conventional swimming caps are worn over the head of the swimmer and are used to increase the hydrodynamics of the swimmer by containing the swimmer's hair, thus reducing the drag caused by the swimmer's head and hair. Swimming caps are also used by swimmers in open water to alert others to the swimmer's presence. The swimming caps are brightly colored for use in this fashion. Currently, a swimming cap is needed in addition to the swimming goggles. This necessitates first putting the swimming cap on, and then putting the swimming goggles on. This also necessitates having to keep track of two pieces of swimming headwear.
Therefore, a piece of swimming headwear is needed that will reliably prevent leakage around the lenses of swimming goggles. Further, a piece of swimming headwear is needed that will improve the hydrodynamics of the swimmer in the water by reducing the drag caused by the headwear. Finally, a piece of swimming headwear is needed that combines the typical swimming goggles and the swimming cap into a single unit.


A display substrate is provided. The display substrate includes an alignment film and a plurality of rows of pixel units arranged in a first direction. Each row of pixel units includes a plurality of pixel units arranged in a second direction. The second direction intersects with the first direction, and the angle between a rubbing direction of the alignment film and the first direction is an acute angle. By setting the angle between the rubbing direction of the alignment film of the display substrate and the first direction to be an acute angle, the contrast of a specific orientation of the display device can be changed.

A liquid crystal display has become a widely used display device due to multiple advantages. The liquid crystal display mainly includes a liquid crystal display panel and a backlight module. The liquid crystal display panel generally includes a display substrate, a color filter substrate and a liquid crystal layer. The liquid crystal layer is sandwiched between the display substrate and the color filter substrate which are oppositely disposed.

Display substrate and manufacturing method thereof, and display device

HEFEI XINSHENG OPTOELECTRONICS TECHNOLOGY CO., LTD


A method of handwriting recognition is provided that combines the efficiency of a point oriented system and the shape information of a segment oriented system in an HMM based handwriting recognition system. The partial segmentation hypotheses obtained using the point oriented features in a conventional Viterbi search are augmented with scores based on segmental shape measurements made on the hypothesized segments. In addition, a method for segmentation of a handwriting sample is accomplished by incorporating a feature to distinguish between continuous and not continuous strokes and influencing the indicated hypothesis score by adding a penalty to the contraindicated hypothesis score.

In a typical Hidden Markov Model (HMM) based recognition system, an input pattern such as a handwritten word, is represented as a time-ordered sequence of observations, usually in the form of feature vectors. Observation probabilities derived from these feature vectors are presented to a network of HMM states. Various methods can then be applied to find either the optimal state sequence or the most likely model for the given observation sequence, thus providing the recognition result.
Stochastic pattern recognizers, such as Hidden Markov Model (HMM) based recognizers are typically point oriented in that the observations are often localized in nature. For example, observations for sampled on-line handwriting might include point positions, interpoint vector orientation such as stroke tangents and curvature. All of these features can, in principle, be measured by looking at one, two, or three handwriting data points, although in practice, the smoothing filters used to reduce noise, require additional local data points to support each measurement. For each new sample data point, taken in chronological sequence, the HMM hypotheses scores are discretely integrated and propagated through the HMM network.
Alternatively, stochastic pattern recognizers can be segment oriented. A segmental feature is a measurement of some characteristic of a contiguous collection of sample points as for example by a sliding window measurement, or as further described below by applying segmental features selected through point based features. In this design, a script is first segmented into letters or subcharacter primitives according to defined boundary conditions such as pen-ups and cusps, as further described below. After the segmentation step a single observation feature vector is computed for each segment.
Point oriented methods avoid actually generating all possible segmentations by simultaneous scoring of all hypotheses and immediate pruning of poorly scored partial hypotheses. Consequently, all possible segmentations and identifications of the input pattern are considered in an efficient manner. However, since point oriented methods only utilize local observation measurements, the system does not consider the shape of the sample, which can only be observed from larger scale measurements.
One method for obtaining shape information in a point oriented system is to extract features from a window of fixed or variable size around each sample point. This method, however, does not adapt to the varying characteristics of pattern shapes, sizes, and segmentation boundaries.
Systems using segment oriented methods obtain greater accuracy by integrating observations over larger regions, but operate less efficiently than point oriented methods. Unlike point oriented systems where each point is analyzed independently, many alternate segments in a segment oriented system can be modelled for a given set of sample points. To generate all segmentations and compute all possible hypothesis scores is an intractable task, thus, impractical.

Interleaved segmental method for handwriting recognition


A ball joint assembly includes a housing (12) defining a socket chamber (18) and having an opening (32); a composite ball joint bearing (20) disposed within the socket chamber; a ball stud (24) supported by the composite ball joint bearing and having a shank portion (30) which projects through the opening of the housing; and a seal assembly (40) adapted to seal the opening between the ball stud and the socket chamber. The composite ball joint bearing is formed from a first plastic material (20A) and a second magnetostrictive alloy material (20B) which is adapted to change its shape when in the presence of a magnetic field to thereby change the rotational and oscillation properties of the ball joint assembly.

This invention relates in general to a ball joint assembly for use in a vehicle suspension system and in particular to an improved composite ball joint bearing for use with such a ball joint assembly.
A ball joint assembly provides an articulated connection between two relatively movable parts. A ball joint assembly is commonly used in motor vehicle steering systems and in motor vehicle suspension systems. Typically, a ball joint assembly for a motor vehicle suspension system includes a ball stud with a spherical ball end and a housing or socket member with a spherical socket. A ball joint bearing member disposed in the housing receives the ball end and supports the ball end for pivotal and rotational movement.

Composite ball joint bearing for a ball joint assembly


A support assembly for supporting a part of a machine, the support assembly comprising at least one support member for supporting a part of the machine on a base, the support member being slidably mounted on a mounting member on the base to be displaceable with respect to the mounting member between a retracted position and an extended position, a jacking leg extending from a lower end of the mounting member to be displaceable between a retracted position and an extended position, a ram acting between the jacking leg and the support member, said ram being operable to move the jacking leg between its retracted and extended positions and to move the support member between its retracted and extended positions to adjust the position of said part of the machine relative to the base.

It is known to provide mobile self-propelled crushing and screening machines for processing materials, such as aggregates, in a quarry or for recycling demolition waste.
Such machines typically comprise a chassis having one or more material processing devices mounted thereon for screening, separating, crushing and/or washing one or more types of aggregate material, for example rocks, stones, gravel, sand and/or soil, or any other material that is quarried, mined or excavated.
Typically, the processing machine is mobile and comprises one or more wheels and/or tracks mounted on the chassis. The machine is usually self-propelled incorporating a drive unit, such as an engine, for driving the wheels and/or tracks.
Typically a feed hopper is provided for receiving material to be processed, the hopper being mounted above a loading end of a feed conveyor, the feed conveyor having a discharge end for delivering the material to the one or more material processing devices.
It is desirable to locate the feed hopper at a relatively low level to reduce the need to raise material to be loaded into the feed hopper onto the feed conveyor. The discharge end of the feed conveyor is required to be located at a higher level so that the material can be fed under the action of gravity to said one or more processing devices, such as a crushing device or screening device. Therefore the feed conveyor is typically upwardly inclined. However, if the angle of inclination of the feed conveyor is too steep, the feed conveyor may be unable to deliver heavier material to the one or more processing devices as the material may simply roll down the conveyor. Therefore it is desirable to permit adjustment of the angle of inclination of the feed conveyor to suit the material being processed.

Support assembly for supporting part of a machine


A method for tracking information in a network environment is provided that includes receiving a packet included within a request that is associated with an end user and communicating the packet to a selected one of a plurality of gateways. An object may be built that correlates an internet protocol (IP) address associated with the end user to the selected gateway such that the object may be used to direct subsequently received packets associated with the end user to the selected gateway. Subsequently received packets may be directed based on end-user IP address information included in the subsequently received packets.

Data networking architectures have grown increasingly complex. In addition, the increase in clients or end users wishing to communicate in a data networking environment has caused many networking configurations and systems to respond by adding elements to accommodate the increase in networking traffic. Communication tunnels may be used in order to establish or to gain access to a network, whereby an end user or an object is tracked through a central location and provides a communication platform for the end user for that communication session.
As the subscriber base of end users increases, proper routing and efficient management of communication sessions and data flows becomes even more critical. Several components are generally implicated in loadbalancing scenarios and, in certain instances, many of these components are delegated a disproportionate number of duties. This overburdening may decrease throughput and inhibit the flow of network traffic, causing congestion or bottlenecks in the system. Additionally, the overwhelming burden on a single element in the communications flow may decrease bandwidth capabilities, as the overtaxed component is forced to work its way through each of its tasks and duties before being able to accommodate additional communications tunnels or end users. Strains on a central location not only slow network traffic, but such a reliance on a single central node may create severe problems in situations where the central node fails or is otherwise unable to perform all of its assigned duties.

System and method for tracking end users in a loadbalancing environment


A method of fabrication of one or more ultra-miniature piezoresistive pressure sensors on silicon wafers is provided. The diaphragm of the piezoresistive pressure sensors is formed by fusion bonding. The piezoresistive pressure sensors can be formed by silicon deposition, photolithography and etching processes.

It is well know that monitoring physiological parameters in situ and in vivo within a blood vessel of a human subject being diagnosed or treated during a medical procedure can provide medical professionals critical information as to the status and condition of the human subject. One particular important and beneficial physiological parameter is the blood pressure within the coronary vessel. Study has shown that the blood pressure in situ and in viva within the coronary vessel can be applied to calculate Fractional Flow Reserve (FFR) which represents the potential decrease in coronary flow distal to the coronary stenosis. More than a decade long clinic study has shown that FFR can provide a quantitative assessment of the functional severity of a coronary artery stenosis identified during coronary angiography and cardiac catheterization, hence, helping the physician to make a quantitative decision on which kind of further treatment is required.
Due to the small diameter of the coronary vessel, which can be as small as less than 1 mm in diameter, it is crucial to have a very small diagnosis device to measure the blood pressure in situ so the blood pressure is not distorted by the diagnosis device itself. In such case, an ultra small pressure sensor is mounted at the distal end of an ultra small delivering device such as a guide wire to form a sensor guide wire assembly. By advancing the distal end of the sensor guide wire assembly to the desired location within the coronary vessel, the ultra miniature pressure sensor mounted at the distal end of the guide wire can perform the measurement of the blood pressure of the coronary vessel in situ and in viva. The Outside Diameter (OD) of the sensor guide wire assembly is typically 0.35 mm. Hence an ultra small sensor is required so the sensor can be mounted at the distal end of the sensor guide wire assembly.
Therefore it is apparent that there is a need to manufacture miniature pressure sensors which can be mounted at the distal end of delivering devices such as guide wires. In order to mount the pressure sensor on a guide wire whose typical Outside Diameter (OD) is about 0.35 mm, the size of the sensor needs to be smaller than 0.3 mm in width and 0.1 mm in height. To fabricate pressure sensors with this small dimension presents a challenge for mass production.

Micromachined ultra-miniature piezoresistive pressure sensor and method of fabrication of the same


A motor-driven sewing machine and method of making the same that includes a needle movable between advanced and retracted positions through a sewing station, a mechanism for controllably advancing the peripheral portion of a work piece past the sewing point and a mechanism for causing the sewing machine to apply stitches to the work piece border as the work piece automatically moves through the sewing station. The sewing machine is provided with a specifically configured feed dog and a presser foot which controllably moves the work piece along a work piece fence surface so that precisely configured stitches are expeditiously formed along the border of the work piece.

1. Field of the Invention
The present invention relates generally to motor driven sewing machines. More particularly, the invention concerns an improved automatic stitching apparatus for automatically sewing the peripheral borders of work pieces of widely varying shapes.
2. Discussion of the Prior Art
Sewing machines are, of course, old in the art and have been designed to accomplish a wide variety of tasks such as utility stitching, decorative stitching, including applique, embroidery, merrow stitching and the like. Some prior art sewing machines are of relative simple construction for light sewing while others are more complex, heavy duty machines for commercial applications.
Regardless of the complexity of the particular machine, most prior art machines operate on basically the same principle and most include similar components such as a throat plate, a presser foot and feed dogs for moving the work piece relative to the needle and throat plate. Usually, stitches made by a conventional prior art sewing machine are formed by two threads which are interlocked. In the prior art vibrating shuttle type machine the upper thread is carried by the needle, while the under thread is unreeled from a bobbin. The descending needle penetrates the fabric and carries the thread along. When the needle rises again, the thread forms a loop on the underside of the fabric. The shuttle, which contains the bobbin of under thread passes through this loop and pulls the under thread along behind it. The shuttle thread is thus enclosed in the loop of the needle thread. The fabric is then moved forward usually by one or more feed dogs. During this forward movement, the needle remains stationary and the shuttle returns to its initial position. This causes the slack loop to be pulled tight so that the two threads interlock in the middle of the fabric. When the forward movement of the fabric stops, the operation is repeated. This method produces a so called lock stitch, which forms a strong but rather rigid seam.
The prior art chain-stitch type sewing machine on the other hand, produces seams having greater resilience. This type of prior art machine typically works with only one thread, which is linked at the underside of the fabric by means of a looper. A variant of this stitch is the overcast stitch which enwraps the edge of the material.
In the more modern domestic type motor driven sewing machines the so called rotary hook is frequently employed. In this type of machine the needle descends through the fabric, and the point of the hook advances to meet the needle. The return movement forms the loop, and the point of the hook enters it. The hook enlarges the loop, the front of which is held in a recess in the bobbin case, while the hook pulls away the other side of the upper thread loop over the bobbin case. The loop slips off the point of the hook while the thread take-up lever pulls the excess thread up again. During the unwinding of the thread, the side of the loop that was held in the recess is released and the loop is pulled tight.
In the typical prior art machine, rotary motion is transmitted through a top shaft to a crank drive for the thread take-up lever. In addition, the bottom shaft is driven by belts or gears from the top shaft. An eccentric cam mounted on the top shaft actuates eccentric rods and thus drives the feed mechanism or feed dogs which are positioned under a base plate and which functions to move the fabric forward. The stitch is made longer or shorter by varying the eccentric stroke and thus varying the amount of rotation that the feed motion shaft undergoes at each stroke.
Exemplary of one form of modern sewing machine is the device described in U.S. Pat. No. 4,250,824 issued to Meier et al. The method described in the Meier et al patent consists of a method for forming an overcast seam using a zigzag sewing machine with a needle bar carrying a needle with needle thread movable into first and second overstitch positions. The machine includes a looper with looper thread and a material feeder for feeding material in a feed direction. The method of the Meier et al disclosure comprises forming a first loop of needle and looper thread with the needle bar in its first overstitch position, moving the needle bar with needle thread into the second overstitch position leaving a loosened thread length between the first and second needle loop, forming a second loop of needle and looper thread with the needle in its second overstitch position forming at least one straight stitch with the needle bar in its second overstitch position in the feed direction of the material, pulling the loosened thread length between the first and second loops into the first overstitch position to form an overstitch loop into which the needle moves to from a subsequent loop, and releasing the overstitch loop.
U.S. Pat. No. 5,517,933 issued to Maraba, Jr. discloses a mechanism and method for forming a facing seam at a relatively high rate that will insure that the cover thread is properly interwoven between each stitch of two parallel rows of stitches. The facing seam is formed by two needles and cooperating loopers for forming two parallel rows of stitches that are joined by a cover thread that lies on the upper surface of the work piece. The cover thread is controlled by a conventional spreader and a cover thread assist member. The cover thread assist member is formed from a lightweight hardened wire that is fixed to a mid portion of the conventional spreader.
Somewhat more pertinent to the present invention is U.S. patent issued to Pirrello No. 3,675,602. This invention disclosed in this patent which is entitled, Automatic Emblem Sewing Machine relates to an improved sewing apparatus for automatically applying finishing stitches to the borders of successively feed work pieces such as cloth emblems. The Pirrello apparatus includes a sewing machine with an automatic needle positioner, a vacuum pickup mechanism for transferring an emblem from a stack of emblems to the sewing station, and an emblem guide mechanism including a servomotor-driven feed wheel laterally spaced from the sewing machine feed dog and controlled by an emblem edge sensor positioned rearwardly of the needle position. A stitch chain cutter actuated by the sewing machine trails the edge sensor and a stitch chain sensor trails the knife. A network controls the sequence of operations to raise the feed wheel and machine foot piece, transfer an emblem from the stack to the sewing station, to lower the wheel and foot piece, to start the sewing machine and to advance the emblem.
As will be better understood from the description which follows, the method of the present invention basically concerns the accomplishment of relatively simple but elegant modification, to a conventional type of commercially available sewing machine to enable the machine to automatically move the work piece, such as a cloth or plastic emblem, relative to the needle along a strategically positioned guide or fence in a manner to rapidly and precisely form virtually perfect finishing stitches along the border of the work piece. Although the finishing operation can be crudely accomplished using the unmodified machine, the operation is extremely time consuming and requires a high degree of operator skill which contributes greatly to the cost of the finished product.


A constant current driver circuit is operable to provide power to a light source. The driver circuit utilizes a microcontroller based oscillator to drive a current source tank circuit. The microcontroller based oscillator is controlled by a differential error feedback signal. The differential error feedback signal is produced by a proportional integral control loop. The proportional integral control loop is used to eliminate steady state error of the driver circuit. Dynamic frequency or duty cycle control of the current source tank circuit by the microcontroller is based on the integrated error signal between a reference current signal and a sensed output current of the current source tank circuit.

The present invention relates generally to constant current driver circuits. More particularly, this invention pertains to improving current control stability in constant current driver circuits.
Referring to FIG. 1, a conventional constant current source controller 104 (micro-controller uC) typically needs two signals to maintain a predetermined current level, a current sensing signal (I_sense) and a reference current signal (I_ref_input). A current source tank 102 of the constant current source circuit 100 may be frequency controlled, duty cycle controlled, or other type of current source tank with a control input that is used to adjust the output current of the current source tank 102. A current sensing resistor R_I_sense is in series with a load R_load (e.g., a light source). It is desirable to minimize the resistance value of the current sensing resistor R_I_sense to minimize power consumption by the current sensing resistor R_I_sense. For a wide range of controlled operating output current, the voltage across the current sensing resistor R_I_sense will also be very wide. For example, for an output current range from 1.4 A to 10 mA, the current sensing signal (i.e., voltage) across the current sensing resistor R_I_sense will vary from 0.14V to 0.001V if the resistance of the current sensing resistor R_I_sense is chosen to be 0.1 ohm, a relatively low resistance value to minimize power consumption. Because this voltage signal is relatively small, a current sensing amplifier such as operational amplifier (OPAMP) U1 is used to amplify the signal. A first resistor R1 and a second resistor R2 determine the gain ratio of the OPAMP U1. The gain between the voltage across the current sensing resistor (i.e., I_sense_in) and the current sensing signal I_sense received at the controller 104 is defined in Equation 1.
                              I          sense                =                                                            R                                                                                1                            +                              R                                                                                2                                                    R                                                                                2                                ·                      I                          sense                                                                                _                                                                                in                                                          EQUATION                                                  1
The controller 104 compares the reference current signal (I_ref_input) and current sensing signal I_sense (i.e., current feedback signal) and maintains the output current level set by reference current signal I_ref_input. The control target is given in Equation 2.
                              I                      ref                                                                          _                                                                          input                          =                              I            sense                    =                                                                      R                                                                                1                                +                                  R                                                                                2                                                            R                                                                                2                                      ·                          I                              sense                                                                                _                                                                                in                                                                        EQUATION                                                  2
The relationship between the reference current signal I_ref_input and the voltage across the current sensing resistor R_I_sense (i.e., I_sense_in) is shown in Equation 3.
                                          I                          ref                                                                                _                                                                                input                                            I                          sense                                                                                _                                                                                in                                      =                                            R                                                                                1                        +                          R                                                                                2                                            R                                                                          2                                              EQUATION                                                  3
The controller (microcontroller) 104 uses the difference between I_ref_input and I_sense to adjust the control frequency or duty ratio of a control signal CTRL provided to the current source tank 102 so that the reference current signal I_ref_input matches the current sensing signal I_sense. The frequency control method for adjusting the output current of the current source tank 102 can be simplified as shown in Equation 4.Δf=Kf*(I—ref_input−I_sense)  EQUATION 4
In Equation 4, Δf is the change in the frequency of the control signal CTRL, and Kf is the gain of the frequency change rate. The control loop is thus a proportional control loop, and the steady state error cannot be zero. This non-zero steady state error can cause control and output instability. Further, analog to digital conversion error for the reference current signal I_ref_input and the current sensing signal I_sense can also cause output instability, particularly when the reference current signal I_ref_input and the current sensing signal I_sense are small (i.e., dimmed operation or a relatively low power mode).

Constant current control for an LED driver circuit using a microcontroller-based oscillator controlled by a differential error feedback signal from a proportional and integration control loop


A method and apparatus for multiplexing reference signals in a predetermined number of Code Division Multiplexing (CDM) groups to balance power across Orthogonal Frequency Division Multiplexing (OFDM) symbols are disclosed. In a wireless communication system, orthogonal sequences used for spreading the reference signals are allocated such that the order of orthogonal sequences allocated to a subcarrier of one CDM group has a predetermined offset with respect to the order of orthogonal sequences allocated to a subcarrier of another CDM group, adjacent to the subcarrier of the one CDM group.

Field of the Invention
The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting Reference Signals (RSs) for data demodulation and a method and apparatus for receiving RSs for data demodulation.
Discussion of the Related Art
Multiple Input Multiple Output (MIMO) has recently attracted interest to maximize the performance and communication capacity of a wireless communication system. Compared to conventional use of a single Transmission (Tx) antenna and a single Reception (Rx) antenna, MIMO adopts a plurality of Tx antennas and a plurality of Rx antennas to thereby increase the transmission and reception efficiency of data. A MIMO system is called a multiple antenna system. MIMO is an application of putting data segments received from a plurality of antennas into a whole message, without depending on a single antenna path to receive the whole message. Consequently, MIMO can increase data transmission rate within a given area or extend system coverage at a given data transmission rate.
MIMO schemes are classified into transmit diversity, spatial multiplexing, and beamforming. Transmit diversity increases transmission reliability by transmitting the same data through multiple Tx antennas. In spatial multiplexing, multiple Tx antennas simultaneously transmit different data and thus high-speed data can be transmitted without increasing a system bandwidth. Beamforming is used to increase the Signal-to-Interference plus Noise Ratio (SINR) of a signal by weighting multiple antennas according to channel states. Weights may be expressed as a weight vector or a weight matrix, called a precoding vector or a precoding matrix.
Spatial multiplexing is further divided into spatial multiplexing for a single user (or Single User MIMO (SU-MIMO)) and spatial multiplexing for multiple users (or Multi-User MIMO (MU-MIMO)).
A Base Station (BS) may transmit a plurality of layers for one or more users. For this purpose, the BS multiplexes the layers into a predetermined time/frequency area and transmits the multiplexed layers to one or more User Equipments (UEs). In general, maximum transmission power available for downlink transmission of the BS is determined by the supported frequency bandwidth, data throughput, and power efficiency of the BS. Because the total transmission power available to the BS is limited to a predetermined value, the BS needs to efficiently allocate transmission power to each subcarrier in an Orthogonal Frequency Division Multiplexing (OFDM) symbol interval.
To demodulate data allocated to a predetermined time/frequency area, a UE estimates the configuration of physical antennas used for the data transmission and channel quality using an RS received from the BS, that is, the UE performs channel estimation using the received RS. Channel estimation and an RS will be described in brief. To detect a synchronization signal, a receiver should have information about a radio channel (e.g. the attenuation, phase shift, time delay, etc. of the radio channel). Channel estimation is the process of estimating the magnitude and reference phase of a carrier. A wireless channel environment is characterized by irregular variations of channel state over time, called fading. The amplitude and phase of the fading channel are estimated through channel estimation. That is, channel estimation refers to estimating the frequency response of a radio interface or radio channel. For channel estimation, a reference value is estimated using some RSs of a BS by a two-dimensional channel estimator. An RS is defined as a symbol with high power without carrying actual data in order to help carrier phase synchronization and BS information acquisition. A transmitter and a receiver can perform channel estimation using such RSs. The receiver can recover data received from the transmitter based on the result of RS-based channel estimation.

This patent is subject to a terminal disclaimer.

Method and base station for transmitting reference signals, and method and user equipment for receiving reference signals