For performing a retry in a data storage device, a spin jitter value corresponding to a desired sector of a disc is determined. A read timing is adjusted according to the spin jitter value of the desired sector. A retry of a data read is performed for the desired sector with the adjusted read timing. Thus, the present invention accounts for eccentricity of the disc as indicated by the spin jitter value during retry of the data read operation.

1. Field of the Invention
The present invention relates generally to data storage devices such as HDDs (hard disc drives), and more particularly to retrying of a data read within a data storage device with adjustment of read timing depending on eccentricity of a disc.
2. Description of the Related Art
A hard disc drive (HDD) is a common data storage device within a computer system. The HDD reads/writes data from/to a disc using a magnetic head. For higher-capacity, higher-density, and smaller-size of the HDD, recording density is increased on the disc in both a rotational direction of the disc (i.e., BPI—bits per inch) and a radial direction of the disc (i.e., TPI—tracks per inch). With such higher density, a mechanism for more accurately controlling the magnetic head is needed.
In addition, with such higher recording density and decreased size of the HDD, characteristics of the HDD mechanisms and circuits change, resulting in error during a data read operation. When such an error occurs, a retry process is performed. Typically upon detection of an error during a data read operation, parameters associated with an off-track read or a data read operation are changed, and the data read operation is repeated with such changed parameters.
If the error recurs, the parameters are changed again, and the data read operation is again repeated with the further changed parameters. Such change of the parameters and data read operation with the changed parameters are repeated up to a predetermined maximum number of times.
If the HDD is subjected to external impact, disc slip occurs. Such disc slip results in disc eccentricity. When a data read operation is performed with such a disc slip, the retry process may be performed too many times because of the disc eccentricity from the disc slip, resulting in failure of the data read operation.

Data read retry with read timing adjustment for eccentrity of disc in data storage device


A novel pair of eyewear includes a frame, one or more optically active eyepieces, a first temple piece and a second temple piece. The first and second temple pieces each include an adjustment mechanism for adjusting the length and angle of the first and second temple pieces. In a particular embodiment, the first and second temple pieces each include a locking mechanism for fixing the length and angle of the first and second temple pieces with respect to the frame.

1. Field of the Invention
This invention relates generally to eyewear, and more particularly to eyewear having adjustable temple pieces. Even more particularly, this invention relates to eyewear in which both the length and the angle of the temple pieces are adjustable. Even more particularly, this invention relates to fixed-temple eyewear in which both the length and the angle of the temple pieces are adjustable.
2. Description of the Background Art
Some modern video presentations (e.g., 3-D movies) require special eyewear to be viewed properly, and the comfort of the eyewear is important for full enjoyment of the video presentation. In order to provide the correct visual experience, the eyewear must fit the wearer properly. In addition, poorly fitting eyewear can be a distraction to the wearer and, therefore, interfere with the wearer's enjoyment of the video presentation.
The problems associated with poorly fitting eyewear are even worse when the eyewear is of the fixed-temple type. In fixed-temple eyewear, each temple piece is fixed in position relative to the frame of the eyewear. In contrast, other types of eyewear include temple pieces that are pivotally connected to the frame by, for example, a hinge pin.
Theaters typically provide eyewear for patrons when showing 3-D movies. A range of sizes is required to provide every potential viewer with properly fitting eyewear. Of course, adult viewers are of a wide variety of sizes. In addition, some audiences include a mixture of adults and children. In that case, at a minimum, the theater must provide both adult and child sized glasses. Optimally, a wide variety of sizes would be provided to ensure the best fit for each viewer.
The need for a variety of different size glasses requires theaters to stock a greater quantity of glasses at a greater cost to the theater. In addition, providing glasses of various sizes also makes distribution before a video presentation more complicated. What is needed, therefore, is eyewear that can properly fit a wide range of different sized viewers, and that is comfortable and functional for all of the viewers, regardless of their size.
Adjustment mechanisms for eyewear are known in the art. For example, U.S. Pat. No. 3,874,775 issued to Lazarus and U.S. Pat. No. 4,848,891 issued to Lee, each discloses an eyeglass frame in which the wearer can easily adjust the pressure exerted on the head by the temple pieces. While both inventions provide an adjustment mechanism to provide some comfort to wearers of different sizes, the solutions are not completely satisfactory. Adjusting the pressure exerted by the temple pieces cannot provide a truly comfortable fit, if the lengths of the temple pieces are not properly sized for the wearer.
U.S. Pat. No. 5,426,473, issued to Riehm, discloses an eyeglass frame in which the temples are adjustable, by changing the point of pivotal attachment to the frame. Adjustments of the pivot points cause the temple pieces to move slightly forward and backward, and also to move slightly toward and away from each other. However, Riehm still does not fully address the problem of adjusting a single pair of eyewear to fit a variety of different sized wearers. Rather, the adjustment mechanism appears to provide only fine adjustment. In addition, the adjustment of the temple pieces in Riehm does not adjust the angle of the temple pieces.
U.S. Published Patent Application No. 2002/0047985 A1, by Hollins, discloses a frame in which both the temple angle and the length of the temple pieces are adjustable. However, the adjustment mechanisms are separate and require separate adjustment. Additionally, providing multiple adjustment mechanisms is generally more complicated and more costly to manufacture.
What is needed, therefore, is eyewear that can properly fit a wide range of different sized viewers, and that is comfortable and functional for all of the viewers, regardless of their size. What is also needed is eyewear that requires a minimal number of adjustment mechanisms. What is also needed is eyewear that has a minimal number of components and is less expensive to manufacture. What is also needed is eyewear that is easy to assemble. What is also needed is eyewear that is easily adjustable by an adult or child. What is also needed is eyewear that is easily adjustable without the use of tools. What is also needed is fixed-temple eyewear that provides some or all of the foregoing advantages.

Adjustable eyewear with fixed temple and method of manufacture

Dolby Laboratories Licensing Corporation


Apparatus and methods for manufacturing a folder which has front and back panels with a divider there between. The divider front and back panels and divider are taped together along a spine of the folder such that the panels and divider can be turned like the pages of a book. There may be one, two, or three or possibly even more dividers with all of the dividers being secured in place at the spine of the folder. The tape(s) may be pleated so that the panel-to-divider and/or divider-to-divider compartments can expand. This pleating technique can also be employed to give expansibility to the single compartment of a file folder which does have internal dividers.

File folders having a front panel and a back panel and a flexible tape hinge extending the length of the folder are used in very large numbers. Often, the hinge of the folder will be pleated so the folder can be expanded. Dividers are many times installed between the front and back panels of the folder so that the material filed in the folder can be separated into different compartments for the convenience of one using that material.
A machine for taping the front and back panels of a folder together to form a hinge is disclosed in U.S. Pat. No. 4,764,240 issued 16 Aug. 1988 to Simeone for APPARATUS AND METHOD FOR AUTOMATICALLY FORMING UNITARY BONDED BOARD STRUCTURES. However, there is to date no machinery which automates the process of taping the dividers between the front and back folder panels.


A test system tests a full system integrated circuit (IC) model that includes a device under test (DUT) IC model and a support IC model. A test manager information handling system (IHS) maps the full system IC model on a hardware accelerator simulator via an interface bus. The hardware accelerator simulator thus emulates the full system IC model. Of all possible fault injection points in the model, the test manager IHS selects a subset of those injection points for fault injection via a statistical sampling method in one embodiment. In response to commands from the test manager IHS, the simulator serially injects faults into the selected fault injection points. The test manager IHS stores results for respective fault injections at the selected injection points. If a machine checkstop or silent data corruption error occurs as a result of an injected fault, the DUT IC model may return to a stored checkpoint and resume operation from the stored checkpoint. The result information is useful in determining a soft error rate (SER) for the DUT IC.

An information handling system (IHS) may include a processor integrated circuit (IC) for processing, handling, communicating or otherwise manipulating information. Modern IHSs often include integrated circuits (ICs) that incorporate several components integrated together on a common semiconductor die. Some IHSs operate as test systems or test managers that evaluate the functionality and performance characteristics of IC designs during the development process of the IC design. A device under test (DUT) is another name for an IC design on which a test system conducts tests.
During operation, ICs may experience hard errors or soft errors. Hard errors are IC faults that persist over time. For example, an IC may experience a short circuit or an open circuit that does not go away with time. In contrast, a soft error is an error that may occur once and then not recur over time. For example, a cosmic ray or alpha particle may pass through a latch in the IC and cause the latch to change state or "flip". Noise in a circuit adjacent the IC may also cause a soft error.
Unfortunately, soft error rate (SER) is increasing in today's ICs due to higher device density in these ICs. Lower IC operating voltage also makes an IC more susceptible to soft errors, thus causing higher SER than in the past. Arrays within ICs, such as memory and caches, are susceptible to soft errors. Combinatorial logic within ICs is also susceptible to soft errors. A conventional way to deal with increasing SER in memory arrays is to employ error correction code (ECC) memory and scrubbing. However, increasing SER in the logic and data flow paths of ICs is a more complex problem. One approach is to employ redundancy in the logic to decrease or correct for SER. However, redundancy is a difficult and costly solution.
It is frequently hard to determine the SER of an IC or system of ICs. One way to perform an SER determination is to actually fabricate the IC or IC system. After fabrication of the IC system, specialized test apparatus may bombard the IC system with cosmic rays and alpha particles in a laboratory environment to create faults or errors. Test apparatus measures the SER of the IC system while bombardment continues. Unfortunately, this approach requires completion of the IC design and fabrication of the actual hardware of the IC system prior to testing. This approach undesirably limits the amount of controllability and observability of the IC design during experimentation.
Another way to determine SER effects is by fault injection into a software simulation or software model of a particular IC design. Unfortunately, this software simulation model approach may be very slow. The size of the software model is also typically limited such that the software model may include just a portion of the IC design rather than the entire IC design when the IC is very large.
It is desirable to provide a method and apparatus for causing soft errors in an IC design that addresses the problems above without actually fabricating the IC design in semiconductor form.

Method and apparatus for testing a full system integrated circuit design by statistical fault injection using hardware-based simulation

International Business Machines Corporation


An electrical tool including: a cutter bit assembly, a driving mechanism for providing a power to the cutter bit assembly, and a flexible transmission mechanism, which is connected at one end thereof to the driving mechanism and connected at the other end thereof to the cutter bit assembly; the flexible transmission mechanism is twistable and bendable, and is configured to transmit the power provided by the driving mechanism to the cutter bit assembly.

In the electrical tool of the related art, a cutter bit or a cutter head is connected to a body of the electrical tool. Since the body of the electrical tool is bulky, a relative large space is required when the electrical tool is used. However, the electrical tool of the related art cannot be used inside small spaces such as an equipment and a pipe, which limits utility range of the electrical tools.

FUZHOU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD.


A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.

This invention is in the field of minority carrier semiconductor devices. The invention relates in particular to methods for improving the operating stability of light emitting semiconductor devices by the intentional introduction of impurities and the devices created using these methods.
Degradation of semiconductor minority carrier devices typically involves an increase in the non-radiative recombination efficiency of the device during the device's operation. The causes of this degradation depend on the type of device, its structure, materials, and operating conditions.
A known double heterostructure light emitting diode ("LED") is shown in FIG. 1. LED 10 is comprised of an optically transparent GaP window/current spreading/contact layer 12, high bandgap AlInP upper confining/injection layer 14, a lower bandgap (Al.sub.X Ga.sub.1-X).sub.0.5 In.sub.0.5 P active layer 16, high bandgap AlInP lower confining/injection layer 18, and conductive substrate 20, which may be formed from GaAs or GaP. P-type contact 21 and n-type contact 23 complete the LED. Light extraction occurs through both the top surface and sides of the LED. The layers are generally doped so that the p-n junction is located near or within the active layer, and ohmic contacts 21 and 23 are made to the p-type and n-type regions of the device. The structure may be grown by any of a variety of methods including metal-organic chemical vapor deposition("MOCVD"), vapor phase epitaxy("VPE"), liquid phase epitaxy("LEP"), molecular beam epitaxy("MBE"), and others.
FIG. 2 is an energy band diagram of the LED shown in FIG. 1. When forward biased, efficient injection of the minority carriers into active layer 16 is achieved by careful placement of the p-n junction. The minority carriers are confined within the active layer of the LED by high bandgap confining layers 14 and 18. The recombination process consists of both radiative recombination which produces the desired light emission and non-radiative recombination, which does not produce light. Non-radiative recombination may result from crystal imperfections within the LED as well as other causes. Light is extracted from the LED through the LED's various transparent layers and surfaces and is focussed into a usable pattern by various reflectors and lenses(not shown).
The LED illustrated in FIG. 1 is only one example of a minority carrier device. A variety of other minority carrier devices, including bipolar transistors, photodetectors, and solar cells operate on similar physical principles. Semiconductor lasers often have a double heterostructure and similarly experience the competition between radiative and non-radiative recombination. The performance and stability of all these devices depends upon maintaining a long carrier recombination lifetime throughout the operating life of the device.
For the LED of FIG. 1, the output power is directly proportional to the internal quantum efficiency and can be expressed as: EQU .eta..sub.external .varies..eta..sub.internal .varies.1+(.tau..sub.r /.tau..sub.nr)!.sup.-1,
where .eta..sub.internal is the internal quantum efficiency, .eta..sub.external is the external quantum efficiency, .tau..sub.r is the radiative recombination lifetime, and .tau..sub.nr is the non-radiative recombination lifetime. .tau..sub.nr is inversely related to the number of non-radiative recombination centers in the active region. The relationship .eta..sub.external and the concentration of non-radiative recombination centers is illustrated by the graph shown in FIG. 3, which shows the external quantum efficiency .eta..sub.external decreasing as the concentration of non-radiative recombination centers increases. A variety of crystal defects can act as non-radiative recombination centers, including substitutional or interstitial impurities such as Cr, Cu, Au, Fe, O and even such shallow dopants as Si, S, Se, native point defects such as self-interstitials and vacancies, impurity or dopant related complexes and precipitates, surface and interface states, and dislocations and other extended defects. These defects can arise during the growth process due to incorporation of residual impurities or epitaxial defect formation.
A minority carrier device can degrade during operation for several reasons. In an LED, the carrier injection efficiency or light extraction efficiency can change depending on the particular device structure and the operating conditions. The most common cause of decreased device efficiency is an increase in the non-radiative recombination efficiency caused by the formation of defects in the active region during stress. This process results in the gradual degradation of device characteristics over time, as illustrated by the graph shown in FIG. 4. The graph shows that .eta..sub.external, the external quantum efficiency, decreases as the period of time the device is under stress increases.
A variety of physical processes contribute to the increase in non-radiative recombination centers in the active region during LED operation. Recombination enhanced or photo-enhanced defect reactions within the active region or at nearby edges or interfaces can contribute to the increase. Other processes include the diffusion or propagation of impurities, native point defects, dopants, and dislocations (also known as dark line defects) into the active layer from other regions of the device. These defects and residual or unintentional impurities have always been considered as detrimental to device performance and great efforts have been expended trying to minimize the concentration of these defects and impurities.

Minority carrier semiconductor devices with improved stability


A system for verifying the quality of a pressing operation of a press-fit part onto a receiving portion of a receiving assembly. The system is applicable to the installation of a bearing cup onto a shaft, or a valve seat into a cylinder head. A probe measures a predetermined dimension of the press-fit part to establish a first measurement value. In the case of a valve seat installed a receiving pocket of a cylinder head, a measuring probe is inserted into the receiving pocket of the cylinder head to measure its depth. The depth is recorded as a second measurement value. The valve seat is then pressed into the pocket, and the residual depth is measured to determine the distance between the outermost surface of the pressed in valve seat and the outer surface of the receiving pocket. A computation compares the depth of the pocket against the thickness of the valve seat to determine a difference which is then compared to the residual depth. During pressing, the hydraulic pressing force is maintained while an impulse force, similar to a hammer blow, is applied to the valve seats to ensure proper seating. The use of a hammer blow obviates the need for excessive hydraulic forces which may damage cylinder head castings. Also, the hydraulic pressing force is monitored over a predetermined distance of insertion of the press-fit part to determine the quality of the interference fit between the press-fit part and the receiving portion of the receiving assembly.

1. Field of the Invention
This invention relates generally to systems for verifying quality control, and more particularly, to a system that ensures that a part or assembly is pressed to depth within a predetermined tolerance and measurement accuracy, and that determines the quality of the interference fit.
2. Description of the Related Art
In current pressing applications it is difficult or impossible to determine whether a pressed-in part has been pressed to a fully seated condition when the operation is complete. Current systems endeavor to ensure that a pressed-in part is fully seated by monitoring the press force and continuing the operation until a predetermined amount of force is applied. This predetermined amount of force is assumed to insure that the pressed part is driven to a full seating position, and that the force applied is representative of the quality of the interference fit. These assumptions, however, are not always correct. The force required to overcome the interference fit in the pressing operation oftentimes exceeds the preset force limit of this known approach. Sometimes, a particle of dirt or metal will become lodged behind the part that is being pressed, causing a false reading on the press force. Thus, the application of the full measure of the predetermined force will not always result in complete inward displacement and seating of the part desired to be pressed into place.
A second current method of verifying press quality is to measure the depth of press at the press ram head. Unfortunately due to part and casting variations this simple single-measurement system is inadequate, as it will not identify the quality of a precision pressing operation.
In the case of a valve seat in an engine head, or a bearing cup in an assembly, the normal working forces, vibration, and heat of the product will finally seat the incorrectly assembled part during the engine or component""s normal working life. This form of seating action, however, will generally cause changes in the running clearances of the assembly that are critical to the product""s over all life or performance.
In addition to the foregoing, valve seats in particular are subjected to tremendous amounts of heat from exhaust gasses. Oftentimes, the temperature of the exhaust gas approaches the melting point of some metals. It is essential that proper seating of the valve seat within the receiving pocket be effected to promote transference of the heat to the cylinder head casting, which contains the cooling water jackets.
There is a need, therefore, for a quality monitoring system that overcomes the foregoing problems.
It is, therefore, an object of this invention to provide a system for pressing-in a press-fit part, such as a valve seat or bearing cup, into a receiving pocket in a receiving assembly, such as a cylinder head, that achieves seating of the part to a predetermined depth reliably.
It is another object of this invention to provide a system for pressing-in a press-fit part to achieve seating within predetermined tolerances without applying excessive continuous insertion force.
It is also an object of this invention to provide a self-aligning press fit ram.
It is a further object of this invention to provide a system for pressing-in a press-fit part to achieve verified seating within predetermined tolerances.
It is additionally an object of this invention to provide a system for pressing-in a press-fit part, such as a valve seat or bearing cup, into a receiving pocket in a receiving assembly, such as a cylinder head, that achieves seating of the part to a predetermined depth reliably, notwithstanding variations in dimensions of the press-fit part.
It is yet a further object of this invention to provide a system for pressing-in a press-fit part, such as a valve seat or bearing cup, into a receiving pocket in a receiving assembly, such as a cylinder head, that achieves seating of the part to a predetermined depth reliably, notwithstanding variations in depth of the receiving pocket.
It is also another object of this invention to provide a system for pressing-in a press-fit part into a receiving pocket in a receiving assembly wherein the insertion force is monitored.
The invention will be shown in one embodiment to be applied to pressing valve seats for an engine head. Bearing cups or any other precision pressing operation could use the same technology.
The foregoing and other objects are achieved by this invention which provides, in accordance with a first method aspect thereof, a method of verifying the quality of a pressing operation of a press-fit part onto a receiving portion of a receiving assembly. The method includes the steps of:
first measuring a predetermined dimension of the press-fit part to establish a first measurement value;
directing a first measuring probe to the receiving portion of the receiving assembly onto which the press-fit part is to be pressed;
second measuring the receiving portion of the receiving assembly onto which the press-fit part is to be pressed, to establish a second measurement value;
urging the press-fit part onto the receiving portion of the receiving assembly;
third measuring a portion of the receiving portion of the receiving assembly that extends beyond a predetermined surface of the press-fit part to establish a third measurement value;
first comparing the third measurement value against the difference between the first and second measurement values to form a first comparison value; and
second comparing the first comparison value against a predetermined comparison value to determine the quality of the pressing operation.
In one embodiment of this method aspect of the invention, the receiving portion of the receiving assembly onto which the press-fit part is to be pressed is a pocket of the receiving assembly. The pocket has a depth that is defined by the distance between outer and inner surfaces thereof Moreover, the step of directing a first measuring probe to a receiving portion of the receiving assembly onto which the press-fit part is to be pressed includes the step of causing the first measuring probe to travel toward and communicate with the inner surface. In a further embodiment, there is further provided the step of second directing a second measuring probe to the outer surface of the pocket of the receiving assembly. The step of second measuring incorporates the step of differential measuring a difference in the respective distances traveled by the first and second measuring probes during the respective steps of first and second directing. Such differential measuring provides an indication of the depth of the pocket of the receiving assembly. In other embodiments, however, where a press-fit part is installed on a shaft, the receiving portion of the shaft is measured in either case, the step of differential measuring incorporates the step of monitoring an electrical signal characteristic provided by a linear variable differential transformer (LVDT), or other measuring device, such as a laser.
In a further embodiment of this first method aspect of the invention, the step of urging the press-fit part into the pocket of the receiving assembly incorporates the further step of translating a ram element in communication with the press-fit part toward the pocket of the receiving assembly. Also, the step of translating a press ram element includes the further step of permitting an angular displacement of the press-fit part with respect to the pocket of the receiving assembly. In this manner, a plane of the press-fit part is made substantially parallel to a plane of the predetermined inner surface of the pocket of the receiving assembly.
In a still further embodiment of this first method aspect of the invention, the step of urging the press-fit part into the pocket of the receiving assembly includes the further step of measuring an insertion force of the press-fit part into the pocket of the receiving assembly to establish an insertion force value over a predetermined insertion distance. This monitoring of force over distance produces an advantageous indication of the quality of the interference fit between the press-fit part and the receiving portion of the receiving assembly. This is enhanced by the step of comparing the insertion force value against a predetermined insertion force value to determine whether the press-fit part is appropriately dimensioned for insertion into the pocket of the receiving assembly.
In a preferred embodiment, the step of urging the press-fit part into the pocket of the receiving assembly includes the further step of measuring an insertion force of the press-fit part into the receiving portion of the receiving assembly to establish an insertion force value over a predetermined insertion distance. The insertion force value is compared against a predetermined insertion force value to determine whether the press-fit part is appropriately dimensioned for insertion into the pocket of the receiving assembly.
In one embodiment, the insertion force is sampled first and second times to produce corresponding first and second insertion force values. These values are correlated to respectively associated installation distances at which the first and second insertion force values were measured. Then a comparison value is produced by comparing the first and second insertion force values. The comparison value, which will have a range of values, is associated with at least one predetermined installation condition. Preferably, a plurality of predetermined installation conditions associated with respective magnitude ranges of the comparison value resulting from said step of comparing. The following are examples:
If the initial and subsequent insertion forces both are below normal, then the press-fit part is too small for the receiving pocket (or too large for the receiving spindle); or
If the initial and subsequent insertion forces both are greater than normal, then either the press-fit part is too large for the receiving pocket (or too small for the receiving spindle); or
If the initial insertion force is normal or greater and the subsequent insertion force is low, then the receiving portion of the receiving assembly is irregularly dimensioned; or
If the initial insertion force is normal and increases significantly, as though the end of the installation travel has been reached, but the installation distance is shorter than a predetermined installation distance, then debris has built up behind the press-fit part, the debris being the result of inadequate pre-installation cleaning or material having been scraped off of the receiving assembly due to the press-fit part being off-center as it is urged onto the receiving assembly.
In a still further embodiment, there is provided the step of continuously sampling the insertion force and the distance over which the insertion force is applied, to form an installation force versus installation distance correlation curve. The correlation curve can provide significant additional information about the quality of the installation of the press-fit part, as well as defects in the machining or preparation of the receiving assembly, which can be reported back to the production line to effect a correction. Such correction can be implemented in-process.
In a still further embodiment, there is provided the further step of applying a supplemental insertion force having a substantially predetermined energy and a short duration. The step of applying a supplemental insertion force includes the further step of accelerating a substantially predetermined mass to impact the press-fit part in the direction of the step of urging. This is performed during the step of urging the press-fit part into the pocket of the receiving assembly. Of course, this step is not limited in its application to the installation of a press-fit part into a pocket, but may be used during installation of a press-fit part onto a shaft.
In still another embodiment of this first method aspect of the invention, after performing the step of second measuring a depth of the pocket of the receiving assembly, and prior to performing the step of urging the press-fit part into the pocket of the receiving assembly, there are provided the steps of:
withdrawing the first measuring probe from the pocket of the receiving assembly; and
installing the press-fit part on a temporary support arrangement.
The press-fit part, in a specific illustrative embodiment of the invention, has an annular configuration. Additionally, the temporary support arrangement includes a finger element about which is installed the press-fit part.
In accordance with a first apparatus aspect of the invention, an arrangement is provided for pressing a press-fit part into a receiving portion of a receiving assembly. In accordance with the invention, a first measuring arrangement measures a predetermined dimension of the press-fit part. A second measuring arrangement measures the receiving portion of the receiving assembly. The press-fit part is urged by a press drive onto the receiving portion of the receiving assembly. Additionally, an impulse drive applies an impetus of short duration to the press-fit part.
In one embodiment of this apparatus aspect of the invention, the receiving portion of the receiving assembly onto which the press-fit part is to be pressed is a pocket of the receiving assembly. There is further provided a holding arrangement for holding the press-fit part in position to be urged into the pocket of the receiving assembly by the press drive. Of course, in some embodiments of the invention, the press-fit part is to be pressed is to be installed on a shaft, as would be the case with a bearing.
There is additionally provided a force measuring arrangement for measuring an insertion force applied to the press-fit part by the press drive. As previously noted, the insertion force can be monitored over a distance of installation of the press-fit part, thereby providing an indication of the quality of the interference fit between the press-fit part and the receiving portion of the receiving assembly.
In a further embodiment of the invention, the second measuring arrangement includes a first probe for communicating with an inner surface of the pocket of the receiving assembly. Additionally, a second probe communicates with an outer surface of the pocket of the receiving assembly. Then, a differential measurement arrangement produces a first electrical measurement signal responsive to a difference in the displacements of the first and second probes. Thus, the depth of the pocket of the receiving assembly is measured.
In a still further embodiment of the invention, there is provided bearing arrangement interposed between the first and second probes. The bearing arrangement includes, in certain embodiments, an interference fit ball or roller bearing arrangement interposed between the first and second probes.
The first probe is arranged, in some embodiments, to communicate with the inner surface of the pocket of the receiving assembly at a plurality of locations thereon. The second probe is arranged to communicate with the outer surface of the pocket of the receiving assembly at a plurality of locations thereon.
An angular displacement arrangement is coupled, in certain embodiments, to the first probe. In this manner, the first probe is angularly displaceable with respect to an axis of translation thereof directed toward the pocket of the receiving assembly and substantially self-aligning with respect thereto. The first and second probes are arranged in certain embodiments of the invention to be axially parallel with respect to each other.
In yet another embodiment of the invention, the press drive is provided with an angular displacement drive that communicates with the press-fit part and renders same to be angularly displaceable with respect to an axis of translation thereof directed toward the pocket of the receiving assembly and substantially self-aligning with respect thereto. The angular displacement of the press drive is responsive to a radius that originates at a distal seating plane of the press-fit part.
In accordance with a further method aspect of the invention, there is provided a method of verifying the quality of a pressing operation of a press-fit part into a pocket of a receiving assembly. The method includes the steps of:
first measuring a predetermined dimension of the press-fit part to establish a first measurement value;
first directing a first measuring probe into the pocket of the receiving assembly;
second directing a second measuring probe onto an outer surface of the receiving assembly;
second measuring a depth of the pocket of the receiving assembly to establish a second measurement value by determining a differential between the steps of first and second directing;
installing the press-fit part on a temporary holding arrangement;
urging the press-fit part into the pocket of the receiving assembly;
third measuring a depth of the pocket to a predetermined surface of the press-fit part to establish a third measurement value;
first comparing the third measurement value against the difference between the first and second measurement values to form a first comparison value; and
second comparing the first comparison value against a predetermined comparison value to determine the quality of the pressing operation.
In one embodiment of this further method aspect of the invention, the step of urging the press-fit part into the pocket of the receiving assembly includes the further steps of
translating a ram element in communication with the press-fit part toward the pocket of the receiving assembly; and
permitting an angular displacement of the ram whereby the press-fit part is self-aligning with respect to the pocket of the receiving assembly.
During performance of the step of urging there is provided the further step of measuring an insertion force of the press-fit part into the pocket of the receiving assembly to establish an insertion force value.
In a further embodiment, there is provided the further step of applying a supplemental insertion force having a substantially predetermined energy and a short duration. This application of a supplemental insertion force incorporates the further step of accelerating a substantially predetermined mass to impact the press-fit part in the direction of the step of urging. Most of the energy supplied to the press-fit part by the impulse of short duration is absorbed by the displacement of the press-fit part in the direction of urging.
In accordance with a further method aspect of the invention, there is provided a method of verifying the quality of a pressing operation of a press-fit part onto a receiving portion of a receiving assembly. The method includes the steps of:
urging the press-fit part by the application of an installation force for a determinable installation distance onto the receiving portion of the receiving assembly;
first measuring a first magnitude of the installation force applied to the press-fit part during said step of urging;
second measuring a first installation distance at which said step of first measuring is performed, the first installation distance being shorter than the determinable installation distance; and
correlating the first force with the first installation distance.
In one embodiment of this further method aspect of the invention, there are provided the steps of:
third measuring a second magnitude of the installation force applied to the press-fit part during said step of urging;
fourth measuring a second installation distance at which said step of third measuring is performed, the second installation distance being shorter than the determinable installation distance;
correlating the second force with the second installation distance; and
comparing the first and second installation forces.
A plurality of installation conditions are associated with respective comparison values that result from the step of comparing. As previously noted, and by way of example, the presence of a non-uniform receiving portion condition is determined in response to a comparison value that corresponds to differences between the first and second installation forces.
In a further embodiment, there are further provided the steps of:
fifth measuring a final installation force applied to the press-fit part during the step of urging, the final installation force being greater than the second magnitude of the installation force; and
sixth measuring a final installation distance, the final installation distance being determined in response to the installation force increasing in magnitude to the magnitude of the final installation force without corresponding progress of the press-fit part onto the receiving assembly.
Of course, the final installation distance is compared to the determinable installation distance to determine whether the press-fit part has been inserted to the necessary extent. A fault condition is issued if the final installation distance IS shorter than the determinable installation distance.
In a highly advantageous embodiment of the invention, there is further provided the step of continuously sampling the installation force and the distance, to form an installation force versus installation distance correlation curve.
As previously noted, the press-fit part is subjected to a supplemental insertion force having a substantially predetermined energy and a short duration. The supplemental insertion force incorporates the further step of accelerating a substantially predetermined mass to impact the press-fit part in the direction of the step of urging. Most of the energy supplied to the press-fit part by the impulse of short duration is absorbed by the displacement of the press-fit part in the direction of urging.
In accordance with a further embodiment of this method aspect the invention, there are further provided the steps of:
first measuring a predetermined dimension of the press-fit part to establish a press-fit part measurement value;
second measuring the receiving portion of the receiving assembly onto which the press-fit part is to be pressed, to establish a receiving portion distance measurement value;
third measuring a portion of the receiving portion of the receiving assembly that extends beyond a predetermined surface of the press-fit part to establish a residual distance measurement value; and
first comparing the residual distance measurement value against a determined difference value corresponding to the difference between the press-fit part and the receiving portion measurement values.


An electrical connector is adapted for mounting on a printed circuit board. The connector includes a dielectric housing having at least one row of terminal-receiving passages. A plurality of terminals are received in the passages and include tail portions in a row for connection to appropriate circuit traces on the printed circuit board. The tail portions of some of the terminals in the row are adapted for insertion into holes in the circuit board. The tail portions of other of the terminals in the row are adapted for surface mounting on the circuit board. Tail portions of some of the terminals extend through holes in the tail aligner while enlarged cutout areas in the tail aligner accommodate the surface mount tail portions of the others of the terminals.

Generally, a typical electrical connector includes some form of dielectric or insulative housing which mounts a plurality of conductive terminals. It is well known to provide electrical connectors mounted to a printed circuit board, with contact terminals therein electrically coupled to respective electrical circuit traces on the board. The terminals typically have solder tails projecting from the connector and inserted into holes in the board, or the terminals may have leg portions generally parallel to the board for surface mounting in electrical engagement with circuit pads on the board. In either instance, the terminals are coupled to the circuit traces on the board most commonly by solder connections, either between the solder tails and plated through-holes in the board or between the surface mounted leg portions and the circuit pads on the board surface.
Circuit board mounted electrical connectors of the character described above typically have the terminals mounted in the connector housing such that the solder tails or the surface mounted leg portions are arranged in rows for solder connection to rows of plated through-holes in the board or rows of circuit pads on the board surface. In high density or fine pitch connectors, a single row of terminals in a housing may have solder tails arranged in two separate staggered rows. Unfortunately, staggering solder tails can lead to problems in high speed applications due to the fact that adjacent terminals have different electrical path lengths. Such different electrical path lengths may result in undesirable signal skew in some applications.
Surface mounted terminals generally provide better electrical performance than the through-hole terminals because the surface mount pads to which the surface mounted terminals are soldered have less capacitance than the through holes to which the through hole terminals are soldered. The capacitance of the through holes can create impedance problems detrimental to the integrity of high-performance signals. Additionally, surface mount pads can be laid out "on pitch" or closer together than through holes thus negating the need to stagger solder tail portions. Consequently, adjacent terminals with surface mount tail portions can have equal electrical path lengths which is also beneficial in high speed applications. Therefore, high performance or high speed terminals are often best configured with surface mounted leg portions.
On the other hand, surface mounted leg portions have a greater tendency to strip off of the circuit pads on the board surface when the terminals are subjected to undesirable shearing forces. Through-hole solder tails provide considerably more mechanical strength at the interconnection interfaces between the terminals and the through holes of the board.
It has been known to provide an electrical connector with a row of terminals with through-hole solder tails as well as a row of terminals with surface mounted leg portions. However, such hybrid row configurations place considerable limits on the circuit design variables of the electrical connector. The present invention is directed to solving the problems or dilemma described above by providing an electrical connector with a unique, versatile terminal arrangement.

Electrical connector for printed circuit boards


Provided are methods for encoding and decoding low-density parity-check (LDPC) codes and a method for forming an LDPC parity check matrix. The method for forming the LDPC parity check matrix, includes the steps of: preparing a plurality of parity check matrixes; and selecting a parity check matrix having maximum performance from the prepared parity check matrixes, wherein the parity check matrix has a degree distribution G(x) that meets an equation,

1. Field of the Invention
The present invention relates to methods for coding and decoding low-density parity-check (LDPC) codes and a method for forming an LDPC parity check matrix, more particularly, to methods for coding and decoding LDPC codes and a method for forming an LDPC parity check matrix using a parity check matrix, which has a degree distribution conforming to a power-law function.
2. Discussion of Related Art
An LDPC code introduced first by Gallager in 1962 is a linear block code in which most of elements of a parity check matrix are zero. Related contents are described in "R. G. Gallager, Low-Density Parity-Check code," IRE Trans. Inform. Theory, vol. IT-8, pp. 21-28, January 1962. However, the code was forgotten for a long time because it was difficult to implement a decoder with technologies at that time, and then has been rediscovered by Mackay, et al. Related contents are described in "D. J. C. MacKay, Good error correcting codes based on very sparse matrices," IEEE Trans. Inform. Theory, vol. 45, pp. 399-431, March 1999. Iterative decoding using sum-product (summation and multiplication) algorithms allows such an LDPC code to hold excellent error recovery performance. In particular, it has been shown (ascertained) that if the LDPC code is configured to be not uniform, namely, an irregular LDPC code, it results in excellent performance over a turbo code. Related contents are described in "T. J. Richardson, M. A. Shokrollashi, and R. L. Urbanke, Design of capacity approaching irregular low-density parity-check codes," IEEE Trans. Inform. Theory, vol. 47, no. 2, pp. 619-637, February 2001. The performance of the LDPC code is generally determined by a configuration of the parity check matrix.
The encoding of the LDPC code can be achieved by an equation of c=aG. In the equation, c means an encoded code vector, a is an information vector, and G corresponds to a parity generation matrix. The parity generation matrix G and the parity check matrix H satisfy an equation, cHT=aGHT=O, for all codewords c or all information vectors a. In the equation, O means a zero vector. In FIG. 1, denoted are examples of the information vector a, the parity generation matrix G, the code vector c, the parity check matrix H, and the zero vector O.
The decoding of the LDPC codes may use a bipartite graph depicted in FIG. 2. The bipartite graph in FIG. 2 corresponds to the parity check matrix shown in FIG. 1. The bipartite graph is composed of check nodes 110 and variable nodes 120, and the variable nodes 120 are composed of information nodes 122 and parity nodes 124. The number of the check nodes 110 is equal to the number of rows in the parity check matrix, and the number of the variable node 120 is equal to the number of columns in the parity check matrix, namely, a length of the code vector. Lines that connect between the check node 110 and the variable node 120 are called edges 130. The edges insertions follow the positions of 1 s of the parity matrix. For example, since there are 1 s at the first, fourth, sixth and seventh columns of the first row in the parity check matrix H of FIG. 1, the first check node of FIG. 2 is connected to the first, fourth, sixth and seventh variable nodes by the edges. Decoding of the LDPC codes is done by an iterative belief propagation via the edge nodes between the check nodes 110 and the variable nodes 120. Related contents are described in "D. J. C MacKay, Good error correcting codes based on very sparse matrices," IEEE Trans. Inform. Theory, vol. 45. pp. 399-431, March 1999.
Design of a good connection structure of a bipartite graph, on which the LDPC code is based, is of prime importance in constructing the LDPC codes. This is because the connection structure between nodes in the graph directly determines the performance of the LDPC code. An LDPC code may be represented by a bipartite graph consisting of variable nodes and check nodes, as described above. The number of edges connected to the node is called the degree of the node. It is known that the performance of codes formulated on the graph is determined by the degree distribution of the graph on the assumption that the graph is a random graph having a tree structure and does not have a cycle therein. Given the degree distribution of the graph, the performance of the graph can be calculated by the density evolution method developed by Richardson, et al. Related contents are described in "T. J. Richardson, R. L. Urbanke, IEEE Trans. Inform. Theory 47, 599, 2001" and "T. J. Richardson, M. A. Shokrollahi, R. L. Urbanke, IEEE Trans. Inform. Theory 47, 619, 2001."
A conventional method for designing the connection structure of the graph, namely, constructing a parity check matrix used for the LDPC codes includes the degree optimization though numerical calculation. On the other hand, codes that provide mathematic expressions for the degree distribution include Tornado code developed by Luby, et al., a right-regular sequence of Shokrollahi, and the like. However, such formation of the LDPC codes according to the prior art requires massive numerical computation and finding an optimal solution is not a feasible task, as is similar to a typical global optimization problem.

Methods for coding and decoding LDPC codes, and method for forming LDPC parity check matrix

Abstract: G                    (        x        )              =                                                      ∑                              k                =                2                                                                    d                i                            -              1                                                      a            k                                          x            k                          +                                            ∑                              k                =                                  d                  i                                                                    d              max                                          C                                                                          k                          -              γ                                                      x            k                                                                        or                                                                          G                                      (              x              )                                          =                                                              ∑                          k              =              2                                            d            max                                                        C                                      (                              k                +                α                            )                                            -            γ                                            x          k                      ,where, ak is a parameter that corresponds to the probability that nodes of the graph have a degree k, C is a parameter that is determined by a normalization condition, G(1)=1, and α, γ are parameters that is optimized through numerical calculations. This may significantly decrease a time to discover an optimal code by using a power-law distribution with less parameters in designing the LDPC codes, as compared with numerical optimization in a global parameter space.

Electronics and Telecommunications Research Institute


A method for suppressing activation of pancreatic stellate cells of a subject includes administering a composition comprising a therapeutically effective amount of Eruberin A. A method of preventing, alleviating or treating pancreatic tumors or pancreatic tumors related diseases includes administering a composition comprising a therapeutically effective amount of Eruberin A. The Eruberin A may be extracted from Pronephrium penangianum.

According to a number of recent studies, such as Patel M, Fine D R. Fibrogenesis in the pancreas after acinar cell injury. Scand J. Surg. 2005; 94(2):108-111 and Erkan M, Adler G, Apte M V, Bachem M G, Buchholz M, Detlefsen S, Esposito I, Friess H, Gress T M, Habisch H J, Hwang R F, Jaster R, Kleeff J, Kloppel G, Kordes C, Logsdon C D, Masamune A, Michalski C W, Oh J, Phillips P A, Pinzani M, Reiser-Erkan C, Tsukamoto H, Wilson J. Stella TUM: current consensus and discussion on pancreatic stellate cell research. Gut. 2012 February; 61(2): 172-178, it is known that pancreatic stellate cells (PSCs) play a critical role in the development of pancreatic fibrosis which is often accompanied with chronic pancreatitis (CP) and desmoplastic reaction of pancreatic cancer. Typically, PSCs localized at the periacinar region of the exocrine pancreas are quiescent under normal condition. As reported in Apte M V, Haber P S, Applegate T L, Norton I D, McCaughan G W, Korsten M A, Pirola R C, Wilson J S. Periacinar stellate shaped cells in rat pancreas: identification, isolation, and culture. Gut. 1998 July; 43(1):128-33, upon injury or inflammation, these PSCs tend to lose their fat-droplets and transform into myofibroblast-like phenotype which can be identified with the presence of α-smooth muscle actin (α-SMA or Acta2). Also reported in Apte M V, Wilson J S. Mechanisms of pancreatic fibrosis. Dig Dis. 2004; 22(3):273-9. and Yoo B M, Yeo M, Oh T Y, Choi J H, Kim W W, Kim J H, Cho S W, Kim S J, Hahm K B. Amelioration of pancreatic fibrosis in mice with defective TGF-beta signaling. Pancreas. 2005 April; 30(3):e71-9, the formation of these fibrotic stress filaments actually elicits the cascade of tissue repairing mechanisms in response to pro-fibrotic and/or pro-inflammatory mediators such as transforming growth factor-beta (TGF-β), tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) being generated upon tissue injury. As identified by van Laethem J L, Robberecht P, Resibois A, Deviere J. Transforming growth factor beta promotes development of fibrosis after repeated courses of acute pancreatitis in mice. Gastroenterology. 1996 February; 110(2):576-82, once the PSCs are activated, they produce massive extracellular matrix (ECM) proteins, namely fibronectin 1 (Fn1) and type I collagen (Col I-α1), for the purpose of tissue repairing as well as regeneration. In fact, properties of stellate cells in the pancreas are similar to those present in other organs such as liver, kidney and lung. Not merely limiting to the pancreas, the production and deposition of ECM in an imbalanced fashion in an organ causes scarring of the parenchyma that is replaced by connective tissues. This indeed leads to permanent morphological damages of the organ. Progressive fibrosis possibly results in anatomical anomalies, organ failure or cancer. Therefore, the abolishment of the overwhelmed tissue repairing mechanism is crucial to the treatment of fibrosis and the associated impairments of the organ. In the case of pancreatic fibrosis, the activation of PSCs plays a central tread in the synthesis, deposition, formulation and remodeling of the various ECM proteins and fibrogenic mediators. It is also known, as reported in Tang D, Wang D, Yuan Z, Xue X, Zhang Y, An Y, Chen J, Tu M, Lu Z, Wei J, Jiang K, Miao Y. Persistent activation of pancreatic stellate cells creates a microenvironment favorable for the malignant behavior of pancreatic ductal adenocarcinoma. Int J Cancer. 2013 Mar. 1; 132(5):993-1003 that by maintaining high levels of ECM proteins and other pro-inflammatory and/or pro-fibrotic factors, PSCs create desmoplasia and a hypoxic microenvironment that promotes the initiation, development, evasion of immune surveillance, invasion, metastasis and resistance to chemoradiation of pancreatic ductal adenocarcinoma (PDAC). PDAC is one of the most common malignant tumors with poor prognosis due to extremely high malignancy, low rate of eligibility for surgical resection and chemoradiation resistance. Increasing evidence indicates that the interaction between activated PSCs and PDAC cells plays an important role in the development of PDAC. Therefore, targeting the interaction between PSCs and PDAC cells, and/or by suppressing the activation of PSCs, may represent novel therapeutic approaches to advanced PDAC, especially therapies that target PSCs of the pancreatic tumor microenvironment.
TGF-β has been reported by previous in-vitro and in-vivo studies such as Hu Q, Noor M, Wong Y E, Hylands P J, Simmonds M S, Xu Q, Jiang D, Hendry B M, Xu Q. In vitro anti-fibrotic activities of herbal compounds and herbs. Nephrol Dial Transplant. 2009 October; 24(10):3033-41 and Schneider E, Schmid-Kotsas A, Zhao J, Weidenbach H, Schmid R M, Menke A, Adler G, Waltenberger J, Grünert A, Bachem M G. Identification of mediators stimulating proliferation and matrix synthesis of rat pancreatic stellate cells. Am J Physiol Cell Physiol. 2001 August; 281(2):C532-43, that it is as being one of the potent inducers to the activation of PSCs. In cultured LTC-14 cells, which is an immortalized rat PSC line established by Sparmann G et al as described in Sparmann, G, Hohenadl, C., Tornoe, J., Jaster, R., Fitzner, B., Koczan, D., Thiesen, H. J., Glass, A., Winder D., Liebe, S., and Emmrich, J. Generation and characterization of immortalized rat pancreatic stellate cells. Am J Physiol Gastrointest Liver Physiol. 2004:287, G211-219, the mRNA and protein levels of the fibrotic filament α-SMA and the production of ECM proteins namely Fn1 and Col I-α1 were remarkably elevated in response to the exogenous addition of recombinant TGF-β (5 ng/mL) in the culturing microenvironment.

Use of a flavanol glycoside for suppressing activation of stellate cells


A neural network type data processing system in which an optical input is received and a normalized optical output is generated. A plurality of light receiving regions of a photovoltaic material generate signals which are fed into amplifiers and summed. The gain of the amplifiers represent the synaptic weights. The output the summed amplified signals is then sent to a portion of a liquid crystal light valve where that portion of the liquid crystal light valve is used to produce a normalized light output.

1. Field of the Invention
The present invention relates to a data processing system which is modeled on the function of neural cells in the brain of an organism, called a "neural network type" system.
2. Discussion of the Prior Art
A data processing system of the so-called "neural network type" has a large number of data lines. Consequently, it can form a few neurons because of the restriction of the number of pins, when realized by hardware. It may also be processed by software so as to avoid such restriction, but the processing speed is not fast enough. It was impossible to apply the data processing system of the neural network type to consumers because it necessitated a high speed and large capacity computer.

Neural network using liquid crystal for threshold and amplifiers for weights


A nuclear medicine imaging apparatus according to an embodiment includes a gradation width storage, an estimating unit, and an image generating unit. The gradation width storage is configured to store the gradation width of an image determined by the temporal resolution of a detector. The estimating unit is configured to estimate the spatial position of a positron on the basis of the spatial position of a set of detectors and a set of detection times. The image generating unit is configured to allocate pixel value to pixels corresponding to the gradation width around the estimated spatial position such that a spatial resolution corresponding to the temporal resolution is reflected on a line linking the set of detectors, thereby generating an image.

In recent years, as a nuclear medicine imaging apparatus, a positron emission computed tomography apparatus (hereinafter, referred to as a PET apparatus) has been known. The PET apparatus generates, for example, the functional image of body tissues. Specifically, in the imaging operation of the PET apparatus, first, a medicine including positron emitting nuclides is given to the subject. Then, the positron emitting nuclides that are selectively introduced into the body tissues of the subject emit positrons and the emitted positrons are coupled to electrons and are then extinguished. In this case, the positron emits a pair of gamma rays substantially in the opposite direction. The PET apparatus detects the gamma rays using detectors that are arrange in a ring shape around the subject and generates a coincidence list from the detection result. Then, the PET apparatus performs reconstruction using a back projection process on the basis of the generated coincidence list, thereby generating a PET image.
In recent years, a PET apparatus having a time of flight (TOF) function has appeared. A PET apparatus that does not have the TOF function performs reconstruction on the assumption that the positrons are present with equal probability on a line of response (LOR) linking a set of detectors that detect a pair of gamma rays. In contrast, the PET apparatus having the TOF function calculates the spatial position of the positron on the LOR using the difference between the detection times when the set of detectors detect the gamma rays. The PET apparatus having the TOF function adds the calculated spatial position and performs reconstruction using the back projection process, thereby generating a PET image.
However, in the related art, it takes a long time to reconstruct an image using the back projection process. As a result, it takes a long time to generate a PET image. For example, in the related art, it takes a few minutes to generate the PET image after the image operation is performed by the PET apparatus. Therefore, it is necessary to reduce the time required to generate the PET image.

Nuclear medicine imaging apparatus and radiation therapy apparatus


A tip shroud rail for a tip shroud of at least one turbine rotor blade, the tip shroud rail comprising a base integrally attached to the tip shroud, a top distally positioned from the base, an upstream surface, and a downstream surface, wherein the tip shroud rail has a height, h, as measured from the base to the top, and a width, w, as measured from the upstream surface to the downstream surface, wherein the width, w, of the tip shroud rail, as measured at the top, is greater than the width, w, of the tip shroud rail, as measured at one-half the height, h/2, of the tip shroud rail.

A gas turbine is a power plant, which produces an enormous amount of power for its size and weight. Due to their efficiency in power production, gas turbines have found increasing service in the past 40 years in the power industry, both among utilities and merchant plants, as well as in oil exploration and production, oil refining, and petrochemical industries.
In the utility industry, the past decade has seen unprecedented consumption of electricity that in many areas of the world frequently exceeds electricity supplies, leading to the possibility of power outages. In certain areas of the world, such electricity deficits have risen to crisis levels. Consequently, there is increasing pressure on utilities and independent power producers to become more efficient in producing power to increase their capacity to meet the growing demand for electricity.
In the case where gas turbine engines are used to produce power, modernizing existing fleets of gas turbines is emerging as an economically attractive solution. To that end, prior modernization efforts include, but are not limited to, improving metallurgical characteristics of gas turbine engine materials, improving combustion characteristics during operation of gas turbines, improving cooling characteristics within gas turbine engines, and improving airflow characteristics during operation of gas turbine engines.
In the area of improving airflow characteristics, parasitic loss of valuable high-temperature high-pressure combustion gases expanding through the turbine section of gas turbine engines is of paramount concern. Such parasitic loss is especially pronounced through clearance gaps located between turbine rotor blades and the outer casing of the turbine section, resulting in substantial reduction in gas turbine efficiency. Consequently, several modernization efforts have focused on reducing such parasitic loss through these clearance gaps.
For example, turbine rotor blades often have shrouds that form a band around the perimeter of a row of turbine rotor blades attached to a rotating disk (turbine wheel). These shrouded turbine rotor blades effectively reduce gas leakage around the tips of the blades and reduce blade vibration. Consequently, the use of shrouds on turbine rotor blades increases the efficiency of the gas turbine unit by improving airflow characteristics. However, in time, centrifugal forces, high temperatures and gas pressure differentials across the top and bottom of the shroud tend to "curl" and deflect the shrouds, resulting in excessive blade deformations (e.g. "creep"; i.e. elongation of the blade), increased parasitic loss, and may ultimately lead to catastrophic failure of the entire gas turbine unit.
To reduce the significance of blade deflection, it is common practice to scallop the turbine rotor blade shrouds, i.e., remove unsupported portions of the shroud. However, scalloping increases the parasitic loss of the combustion gases around the turbine rotor blades. Another common practice is to incorporate tip shroud rails in the turbine rotor blade shrouds that stiffen the shroud and form a labyrinth with matching rails of stationary shrouds attached to an outer casing of the turbine section. However, tip shroud rails currently incorporated on the turbine blade shroud have a trapezoidal profile, tapering in width as measured from the base of the rail to the top of the rail. Such a profile allows for ease of casting, but is the least effective in stiffening the shroud and in retarding parasitic loss of expanding combustion gases through the clearance gaps.
Another effort to reduce parasitic loss is the use of a honeycomb rub strip mounted to the stationary shroud, which, in turn, is supported by an outer casing. Honeycomb rub strips operate as labyrinth seals, which reduces the amount of parasitic loss of the expanding combustion gas, thereby increasing the efficiency of the gas turbine. However, the use of honeycomb rub strips requires the use of hardened cutter teeth attached to the tip shroud rails to cut a path through the honeycomb rub strip. These cutter teeth often damage the honeycomb rub strip and significant portions of the tip shroud rail grind down during operation of the gas turbine, resulting in partial or complete loss of the rails. Consequently, parasitic loss of expanding combustion gases between clearance gaps dramatically increases and the turbine rotor blades suffer accelerated deflection, resulting in substantial power loss and ultimately catastrophic failure of the gas turbine unit.
Although these efforts are advances in the art, there is still a need to increase gas turbine efficiency without compromising the long term mechanical reliability of the gas turbine. It has been found that generating a vortex or air dam at the leading edge of the tip shroud rails advantageously reduces parasitic air loss by restricting the flow of the combustion gases through the clearance gaps and redirecting the flow of the combustion gases to the airfoils of the turbine rotor blades, eliminating the need to use honeycomb rub strips to reduce parasitic air loss.
It has also been found that employing tip shroud rails that taper in width as measured from the top of the tip shroud rail to the base of the tip shroud rail dramatically reduces parasitic loss of expanding combustion gases between clearance gaps over existing tip shroud rails that taper in width as measured from the base of the tip shroud rail to the top of the tip shroud rail.
It has also been found that employing tip shroud rails that have a concave upstream surface dramatically reduces parasitic loss of expanding combustion gases between clearance gaps over conventional tip shroud rails.
It has also been found that employing tip shroud rails that have a convex upstream surface dramatically reduces parasitic loss of expanding combustion gases between clearance gaps over conventional tip shroud rails.


Provided are azeotrope-like compositions consisting essentially of 1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane and uses thereof, including use in refrigerant compositions, refrigeration systems, blowing agent compositions, and aerosol propellants.

Field of the Invention
The present invention provides azeotrope-like compositions of 1,1,1,2-tetrafluoropropene (HFO-1234yf) and 1,1,1,2-tetrafluoroethane (HFC-134a), and uses thereof, including use in refrigerant compositions, refrigeration systems, blowing agent compositions, and aerosol propellants.
Description of the Related Art
Fluorocarbon based fluids have found widespread use in industry in a number of applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, and gaseous dielectrics. Because of the suspected environmental problems associated with the use of some of these fluids, including the relatively high global warming potentials associated therewith, it is desirable to use fluids having low or even zero ozone depletion potential, such as hydrofluorocarbons ("HFCs"), and low global warming potential. Thus, the use of fluids that do not contain chlorofluorocarbons ("CFCs") or hydrochlorofluorocarbons ("HCFCs") is desirable. The use of alkenes is also desirable due to there short atmospheric lifetime which results in a relatively low global warming potential. Additionally, the use of single component fluids or azeotropic mixtures, which do not fractionate on boiling and evaporation, is desirable. However, the identification of new, environmentally-safe, non-fractionating mixtures is complicated due to the fact that azeotrope formation is not readily predictable. The industry is continually seeking new fluorocarbon based mixtures that offer alternatives, and are considered environmentally safer substitutes for CFCs and HCFCs. Of particular interest are mixtures containing hydrofluorocarbons, hydrofluorolefins ("HFOs") and other fluorinated compounds, which have a zero ozone depletion potentials and low global warming potential. Such mixtures are the subject of this invention.
The present invention provides compositions that help to satisfy the continuing need for alternatives to CFCs and HCFCs. According to certain embodiments, the present invention provides azeotrope-like compositions comprising of 1,1,1,2-tetrafluoropropene (HFO-1234yf) and 1,1,1,2-tetrafluoroethane (HFC-134a). The preferred compositions of the invention tend to exhibit relatively low global warming potentials ("GWPs"). Accordingly, such compositions can be used to great advantage in a number of applications, including as replacements for CFCs, HCFCs, and HFCs (such as HFC-134a) in refrigerant, aerosol, blowing agents, and other applications. This azeotrope-like composition can be used as a replacement in systems already utilizing HFC-134a where a significant reduction in GWP is desired. Additionally, it has been surprisingly found that azeotrope-like compositions of HFO-1234yf and HFC-134a can be formed. Accordingly, the present invention provides methods of producing an azeotrope-like composition comprising combining HFO-1234yf and HFC-134a in amounts effective to produce an azeotrope-like composition. In addition, it has been found that the azeotrope-like compositions of the present invention exhibit properties that make that make them advantageous for use as, or in, refrigerant, aerosol, and blowing agent compositions. Accordingly, in yet other embodiments, the present invention provides refrigerant compositions comprising an azeotrope-like composition of HFO-1234yf and HFC-134a.

Azeotrope-like compositions of 1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane


The present invention provides a method of forming a Self-aligned contact with fewer process steps. The invention includes a three step insitu process of (1) a first descum step, (2) a dry etch step and (3) second descum step followed by (4) an isotropic etch step. The process comprises coating, exposing, and developing, and baking a photoresist layer over an insulating layer. In an important process stage, three steps are performed: (1) an insitu first descum step, (2) a dry etch step and (3) a second descum step. The dry etch step forms a first self-aligned contact opening. Next, the first contact opening is isotropically etched forming a smoother second contact opening 44. The photoresist layer 30 is then removed. Lastly, a metal layer 60 is deposited in said second self aligned contact opening 44. The invention reduces cycle time and eliminates several process steps while maintaining high yields. The smoother second contact opening 44 provides better metal adhesion.

1) Field of the Invention
This invention relates generally to the fabrication of contact openings for a semiconductor device and more particularly to a method of etching and descuming to form a contact opening in an insulating layer for a self-aligned contact in a semiconductor device.
2) Description of the Prior Art
In the manufacture of semiconductor devices, it is normally necessary to make contact to device regions on the substrate surface through an overlying dielectric layer. This is accomplished by first forming an opening or via (contact via) in the dielectric layer over the region to be contacted, and next filling the contact via with a conductive material. The opening is often formed by using a plasma etch. After the etch, photoresist is removed by ashing using a plasma. Etching using a plasma is an indispensable technique in etching a micropattern of an integrated circuit.
In addition to filling the vias with a conductive material, it is necessary to electrically connect certain device regions with others, as well as to provide for electrical connection to external leads. Theses requirements are met by forming a wiring layer over the surface of the substrate. The wiring layers are formed by depositing a conductive material on top of the dielectric layer in which the vias have been formed. The conductive layer is then masked and etched to leave continuous lines of conductive material necessary to match the appropriate connections to the device regions of the substrate. These lines are known as interconnects.
As device geometries have shrunk to submicron levels and devices have become more densely packed on the substrate surface, the aspect ratio (ratio of height to width) of the contact opening to the device regions has greatly increased. The sharp angled surface has caused problems with metal adhesion to the insulating layer.
Moreover, conventional contact opening processes are complicated, require many process steps and do not adequately remove polymer and photoresist residue from the contact openings. This reduces yields and increases contact resistance.
Many solutions have been tried without satisfactory success to reduce the process complexity and eliminate the polymer/precipitation problem. U.S. Pat. No. 5,397,432 (Konno et al.) shows a method and apparatus for plasma etching Al metal and ashing. The ashing operation has H.sub.2 O added. The asher is connected to the RIE etcher. U.S. Pat. No. 5,468,686 (Kawamoto) shows a method of cleaning a chamber of a dry etching system. U.S. Pat. No. 5,284,547 (Watanabe) teaches a plasma-process system with a batch scheme-ashing and etching are performed. However, there is still a need for an improved descum process that reduces cycle time and eliminates process steps.

Insitu contact descum for self-aligned contact process

Taiwan Semiconductor Manufacturing Company, Ltd.


A dual frequency transducer array includes one or more low frequency transducer arrays and a high frequency transducer array. Unfocused ultrasound such as plane waves are transmitted by the one or more low frequency transducer arrays in a number of different directions into an imaging region of the high frequency transducer array. High frequency echo signals produced by excited contrast agent in the imaging region are received by the high frequency transducer array to produce a contrast agent image. In another embodiment, the high frequency transducer produces unfocused ultrasound to excite the contrast agent in the imaging region and the low frequency transducer(s) receives low frequency echo signals from the excited contrast agent. A tissue image is created from echo signals received by the high or low frequency transducer. Echo data from the tissue image and the contrast agent image are combined to produce a combined tissue/contrast agent image.

As will be appreciated by those skilled in the art, most modern ultrasound imaging systems work by creating acoustic ultrasound signals (i.e. pressure waves) from a number of individual transducer elements that are formed in a sheet of piezoelectric material. By applying a voltage pulse across an element, the element is physically deformed thereby generating a corresponding ultrasound signal. The signal travels into a region of interest where a portion of the signal is reflected back to the transducer as an acoustic echo signal. When an echo signal impinges upon a transducer element, the element is vibrated, causing a corresponding voltage to be created that is detected as an electronic signal. Electronic signals from multiple transducer elements are combined and analyzed to determine characteristics of the combined signal such as its amplitude, frequency, phase shift, power and the like. The characteristics are quantified and converted into pixel data that are used to create an image.
In some environments, it is desirable to increase the contrast of the tissue being imaged. This is particularly true when obtaining images of blood vessels and blood flow. To increase the contrast, intravascular contrast agents are often administered in the blood vessels. Such contrast agents generally comprise lipid or protein encapsulated microbubbles that travel through the circulatory system and have an acoustic impedance that is approximately four orders of magnitude less than the surrounding tissue. This large acoustic impedance mismatch allows the microbubbles to been seen clearly in an ultrasound image.
In some systems, contrast agents are insonified and imaged in the same frequency band. For example, low frequency ultrasound (e.g. 1-5 MHz) is directed into the subject and corresponding echo signals in the same frequency band are detected and used to produce a tissue image. One problem with this method is that because the transmitted and received ultrasound signals are in the same frequency band, it is often difficult to distinguish between soft tissue backscatter and backscatter from the contrast agent in the blood vessels, unless a significant amount of contrast agent is supplied to make the signal from the blood vessels stronger than the signal from the tissue. To overcome this problem, it is also known that the insonification of the contrast agent and the detection of the ultrasound echoes from the contrast agent can be performed in different frequency bands. Because the contrast agent has a non-linear response to applied ultrasound, it is possible to insonify the contrast agent in one frequency band and analyze harmonics or subharmonics of the excitation frequency to image the contrast agent. Harmonic imaging where ultrasound excitation signals are applied in a relatively low frequency range (e.g. 1-5 MHz) and the generated echo signals are analyzed with the same transducer to extract the harmonic component of the signal is a known technique to enhance the microbubble contrast signal relative to the tissue signal.
For many applications, the frame rates at which harmonic images can be produced by traditional line-based imaging are insufficient to allow quickly moving tissue structures to be adequately captured by an ultrasound imaging system. Plane wave imaging is a technique whereby unfocused ultrasound is transmitted into the body over a large portion of a region of interest at once and the corresponding echo signals are simultaneously received at multiple transducer elements. The received echo signals are beamformed to produce images of the region of interest at high frame rates. Image quality can be improved while still maintaining fairly high frame rates by steering the plane waves in several directions and combining the echo data using a spatio-temporal beamformer to produce a composite image of the tissue.

Dual frequency plane wave ultrasound imaging system


An ultrasonic probe includes a plurality of piezoelectric elements arrayed on acoustic absorption backing material with predetermined spaces, a plurality of acoustic matching members formed on the piezoelectric elements and arrayed with gaps smaller than array gaps of the piezoelectric elements, polymer resin with which only the gaps between the piezoelectric elements are filled and having hardness lower than material of the piezoelectric elements, and an acoustic lens formed on the plurality of acoustic matching members.

The present invention relates to an ultrasonic probe used in the field of an ultrasonic apparatus for extracting an image of the inner part of an object to be examined by means of ultrasonic beams and particularly to the technique for obtaining a satisfactory ultrasonic image.
An ultrasonic diagnostic apparatus employs an ultrasonic probe to transmit ultrasonic beams to the inner part of an object to be examined and receive an echo signal from the inner part of the object. As the ultrasonic probe, there are one having an array transducer composed of a large number of elongate rod-like elements and another having a single disk-shaped element transducer. The former is largely used in a so-called electronic scanning type ultrasonic apparatus and the latter is chiefly used in a mechanical scanning type ultrasonic apparatus.
In the electronic scanning type ultrasonic apparatus, a plurality of elongate rod-like elements are constituted as one group and the respective elements in the group are given predetermined delay times, respectively, so that each element is driven with the predetermined delay time given thereto. Thus, the probe transmits an ultrasonic beam focused at a predetermined depth in a predetermined direction within the object to be examined. Further, upon reception of the echo signal, the respective elements are also given delay times varying with time to thereby receive an ultrasonic beam from a predetermined direction. The ultrasonic beam for transmission and reception is moved in the azimuth direction of the elements to scan the inner part of the object, so that ultrasonic image data are obtained.
In order to obtain a satisfactory ultrasonic image by the scanning, it is necessary to form the narrow ultrasonic beam which has the excellent directivity over the whole scanning range of the beam. For this purpose, it is important that the acoustic crosstalk between adjacent elements is small.
The basic structure of the ultrasonic probe generally includes an acoustic absorption backing material, a piezoelectric element, an acoustic matching layer and an acoustic lens which are laminated in order. In order to reduce the acoustic crosstalk between the adjacent elements, that is, in order to improve isolation between the adjacent elements, the element is cut together with the acoustic matching layer deeply to the degree that gaps are formed in the acoustic absorption backing material, so that the cut elements are separated from each other. The gaps are filled with polymer resin in order to prevent the elements from being damaged when external force is exerted to the elements. In other words, the conventional ultrasonic probe is manufactured by way of the process in which the piezoelectric element and the acoustic matching layer are first fixed on the acoustic absorption backing material and are then cut by a dicing saw to form an array of the piezoelectric elements. Accordingly, in the ultrasonic probe using the conventional manufacturing method, it is a matter of course that the width of the array of the piezoelectric elements is equal to that of the acoustic matching layer.
Accordingly, in the conventional probe, area for transmission and reception of the element is identical with that of the acoustic matching layer. Further, in the prior art, gaps between the piezoelectric elements are also filled with polymer resin, while the filling of polymer resin is made after cutting the acoustic matching layer and the piezoelectric material with electrodes simultaneously, in order to prevent damage of the piezoelectric elements when external force exceeding forecasted force in the diagnosis is exerted to the elements and accordingly both of gaps between the piezoelectric elements and between the acoustic matching layer elements are filled with the polymer resin.
Recently, the array of the piezoelectric elements of the ultrasonic probe tend to be made small and densified to form the high density structure in order to increase the lateral resolution of an image. Therefore, the width of the array element is as narrow as about 0.2 mm. On the other hand, since the thickness of the piezoelectric element is determined by a frequency or a wavelength .lambda. (actually .lambda./2) of ultrasonic beams, the thickness of the piezoelectric element of the probe is, for example, about 0.44 mm for a frequency of ultrasonic beams of 3.5 MHz and about 0.6 mm for a frequency of 2.5 MHz. Accordingly, as the frequency of ultrasonic beams is low, a ratio of the thickness and the width of the piezoelectric element is large. When the piezoelectric elements are made small for the high density structure, the following problems occur.
More particularly, since miniaturization of the piezoelectric elements for attainment of the high density structure is to narrow the width of the element, it is meant that energy of ultrasonic beams transmitted by a single piezoelectric element and energy of ultrasonic beams received by the single piezoelectric element are reduced as compared with the prior art. That is, the sensitivity of the piezoelectric element is reduced. When the reduction of the sensitivity is to be compensated by a receiving circuit, noise is introduced by an amplifier of a signal and a complicated circuit for preventing the introduction of noise is required.
Further, when the piezoelectric elements having the width of 0.2 mm as described above are formed, the width of the gaps between the piezoelectric elements is as narrow as about 0.075 mm. It is extremely difficult as compared with the prior art to form the gaps having such a width by means of a dicing saw while the acoustic matching layer and the piezoelectric material are adhered to each other as in the prior art. Since the depth of the gaps must be made deeper as the frequency of ultrasonic beams is lower, the difficulty to form the gaps is increased.
Furthermore, since the width of the elements is very narrow and the strength thereof is reduced due to the high density structure of the piezoelectric elements, gaps between the elements are filled with polymer resin to increase the strength, while there is a problem that acoustic crosstalk is produced between adjacent piezoelectric elements through the polymer resin when the elements are driven. In addition, since the width of the gaps relative to the width of the piezoelectric elements is increased, a problem concerning the grating lobe also remains.
On the other hand, attainment of the broad bandwidth is also treated as a problem heretofore apart from the high density structure of the piezoelectric elements, while any methods for solving this problem are not found at the present time and presentation of some solving methods thereof is desired.
It is an object of the present invention to solve the above problems by providing an ultrasonic probe capable of obtaining a satisfactory ultrasonic image.

Ultrasonic probe and manufacturing method thereof


A device may receive a hash table that includes lists of protocol detectors, wherein the hash table is generated based on historical process data identifying potential process variables associated with an industrial control system. The device may receive a packet identifying potential process variables associated with the industrial control system, and may extract, from the packet, packet data identifying a source address, a destination address, a port, and a transport protocol. The device may compare the packet data with data in the hash table to identify a set of lists of protocol detectors, and may process the packet data, with the set of lists of protocol detectors, to determine a matching protocol, no matching protocol, or a potential matching protocol for the packet. The device may perform one or more actions based on determining the matching protocol, no matching protocol, or the potential matching protocol for the packet.

An industrial control system may include several types of control systems and associated instrumentation used for industrial process control. The industrial control system can range from a few modular panel-mounted controllers to large interconnected and interactive distributed control systems with thousands of field connections. The industrial control system receives data from remote sensors measuring industrial process variables, compares the sensor data with set points, and derives command functions used to control an industrial process through control elements (e.g., control valves, circuits, power sources, and/or the like).

Systems and methods for identifying unknown protocols associated with industrial control systems