A transparent photochromic glass displaying a pink hue in the darkened state which, in bodies of 2 mm cross section, will exhibit the following optical properties:. (a) a clear (undarkened) luminous transmittance greater than 82%; PA0 (b) a darkened luminous transmittance after 15 minutes' exposure to actinic radiation at 25.degree. C. between about 20-32%; PA0 (c) a darkened luminous transmittance after 15 minutes' exposure to actinic radiation at 40.degree. C. between about 35-55%; PA0 (d) a rate of fading such that the luminous transmittance after 5 minutes' removal from actinic radiation at 25.degree. C. will be at least 30 percentage units higher and will exhibit a luminous transmittance greater than 50%; PA0 (e) a x trichromatic coordinate between 0.3500 and 0.3700; and PA0 (f) a y trichromatic coordinate between 0.3250 and 0.3450;. said glass consisting essentially, expressed in terms of weight percent on the oxide basis, of. ______________________________________ SiO.sub.2 52-58 ZrO.sub.2 1.5-2.8 K.sub.2 O 4-8 B.sub.2 O.sub.3 16-21 Li.sub.2 O 2-3.5 CaO 2-3.5 Al.sub.2 O.sub.3 6-9 Na.sub.2 O 0-2.5 TiO.sub.2 1.2-2.5 ______________________________________. with photochromic elements consisting essentially, as analyzed in weight percent, of ______________________________________ Ag 0.15-0.25 Cl 0.25-0.40 Br 0.06-0.13 CuO 0.003-0.007 ______________________________________. and containing at least 2 ppm, but less than 10 ppm, Au and up to 0.9% Er.sub.2 O.sub.3.

Transparent photochromic glasses or phototropic glasses, as they have been variously termed, have been marketed commercially for about 25 years. Such glasses darken (change color) when exposed to actinic radiation, commonly ultraviolet radiation, and fade back to their original color, i.e., they return to their original optical transmission, when withdrawn from the actinic radiation. The basic disclosure of such glasses is found in U.S. Pat. No. 3,208,860 (Armistead et al.), which patent is directed generally to silicate base glass compositions wherein crystals of silver chloride and/or silver bromide and/or silver iodide confer the photochromic behavior to the glass. The preferred base glasses had compositions within the alkali metal aluminoborosilicate field.
A multitude of patents have been granted subsequently, those patents being drawn to expressly-delineated areas of silicate glass compositions which exhibited exceptional or unusual photochromic properties and/or other remarkable physical and/or chemical behavior. And, in general, the glass compositions encompassed within those patents have also been based in the alkali metal aluminoborosilicate system with silver chloride and/or silver bromide crystals providing the desired photochromism.
The most common application of photochromic glasses has been as ophthalmic lenses and non-prescription sunglasses. The most widely-marketed photochromic glasses for ophthalmic lenses have been produced by Corning Incorporated, Corning, New York, under the trademarks PHOTOGRAY EXTRA and PHOTOBROWN EXTRA. The glass fabricated into ophthalmic lenses marketed under the trademark PHOTOGRAY EXTRA is essentially colorless in the original or fully faded state, and darkens to a gray coloration when subjected to actinic (ultraviolet) radiation. That glass is included within U.S. Pat. No. 4,190,451 (Hares et al.). The glass formed into ophthalmic lenses marketed under the trademark PHOTOBROWN EXTRA is likewise essentially colorless in the original or fully faded state, but darkens to a warm brown coloration when exposed to actinic (ultraviolet) radiation. That glass composition is encompassed within U.S. Pat. No. 4,251,278 (Hares).
The wearer of photochromic eyeglasses not only wishes to have the glass demonstrate good photochromic properties, i.e., the glass quickly darkens to transmissions below about 40% at room temperature, preferably below 30%, and fades quickly, i.e., the glass fades at least 25 percentage points, preferably at least 30 percentage points, after a five minute withdrawal from the actinic radiation at room temperature, but also wishes to have the glass be cosmetically appealing. This concern with cosmetic appearance is especially prevalent in the sunglass market where all colors and shades of colors can be found.
Various means have been proposed for imparting color to photochromic glasses. For example, U.S. Pat. No. 4,240,836 (Borrelli et al.) discloses modifying the surface of silver halide-containing glass articles by heat treating such glass articles under critically-defined conditions. The heat treatment causes the reduction of silver ions to metallic silver in contact with silver halide microcrystals in a region very near the surface of the glass, with the observed color being determined by the geometric form and arrangement of metallic silver on those microcrystals. Such glass articles can exhibit orange, red, purple, or blue surface coloration in the undarkened state.
Various well-recognized glass colorants have been added to the base photochromic glass composition to impart permanent coloration thereto. For example, U.S. Pat. No. 4,018,965 (Kerko et al.) describes the addition of colorants such as the rare earth metal oxides Er.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Ho.sub.2 O.sub.3 and/or the transition metal oxides CoO, NiO, and Cr.sub.2 O.sub.3 to produce a variety of permanent tints in the glass.
As was noted above, U.S. Pat. No. 4,251,278 discloses the production of photochromic glasses which are essentially colorless in the undarkened state, but which demonstrate a warm brown coloration when exposed to actinic radiation. Those glasses contained crystals of silver chloride and/or silver bromide and/or silver iodide to impart photochromism to the glass. The warm brown color was developed in the glass due to the presence of 1-10 parts per million (ppm) of Pd and/or Au. The patent also describes transparent photochromic glasses exhibiting a brown coloration in the undarkened state and a deeper warm brown coloration in the darkened state. Those glasses also contained crystals of silver chloride and/or silver bromide and/or silver iodide to produce photochromism therein, but included more than 10 ppm Pd and/or Au. Finally, the patent further discloses transparent, silver halide-containing photochromic glasses containing 1-50 ppm Pd plus up to 1% total of 0-0.5% CoO, 0-1% NiO, and 0-1% Cr.sub.2 O.sub.3 and/or up to 5% total of at least one rare earth metal oxide selected from the group of Er.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Ho.sub.2 O.sub.3, and Nd.sub.2 O.sub.3, wherein the glass exhibits a particular tint in the undarkened state, that tint being dependent upon the colorant selected, but which tint is complemented with a warm brown hue in the darkened state. As an example, the patent cites the use of Er.sub.2 O.sub.3, but without specifying the amount included, to impart a permanent pink color to the glass in the undarkened state which, upon the inclusion of Pd and/or Au in amounts greater than 10 ppm, will demonstrate a brown coloration with a warmer tint being complemented with the pink from the Er.sub.2 O.sub.3.
U.S. Pat. No. 4,746,633 (Mazeau et al.) describes transparent photochromic glasses that in a thickness of 2 mm can darken to a comfort range, i.e., an optical transmission of about 35-60%, when exposed to actinic radiation at room temperature, and which will fade back to a transmission greater than 70% after five minutes' withdrawal from the actinic radiation. The base glasses therefor consisted essentially, expressed in terms of weight percent on the oxide basis, of
______________________________________ SiO.sub.2 46-60 MgO 0-3.5 B.sub.2 O.sub.3 16-28 CaO 0-6 Al.sub.2 O.sub.3 4-11 SrO 0-6 ZrO.sub.2 2-6 BaO 0-6 Al.sub.2 O.sub.3 + ZrO.sub.2 6-13 MgO + CaO + SrO + BaO 0-7 Li.sub.2 O 2-5 P.sub.2 O.sub.5 0-5 Na.sub.2 O 0-4 TiO.sub.2 0-3. K.sub.2 O 2.5-9 ______________________________________
The "photochromic elements", i.e., Ag, Br, Cl, and CuO, consisted essentially, as analyzed in weight percent, of
______________________________________ Ag 0.13-0.18 Cl 0.16-0.34 Br 0.08-0.14 CuO 0.001-0.004 ______________________________________
The patent notes that additions of up to about 1% total of classic glass colorants such as CeO, Er.sub.2 O.sub.3, MnO, and NiO can be incorporated to tint the glass, and up to about 1% SnO or up to 4 ppm Pd can be added to provide a brown coloration in the darkened state.
Surveys and focus group studies have indicated a substantial market for transparent photochromic glasses that, in thicknesses of 2 mm, would darken to a dark range upon exposure to actinic radiation at room temperature, that would fade rapidly when removed from the actinic radiation, and that would exhibit a pink coloration of a definite hue in the darkened state. Thus, those studies showed a consumer desire for glasses which, in the darkened state, would exhibit a color as defined by the trichromatic coordinates determined through the trichromatic colorimetric system of the C.I.E. of 1931 utilizing Illuminant C as the light source between the ranges of
x>0.3500 and <0.3700 and PA1 y>0.3250 and <3450.

Photochromic glasses which darken to a pink hue


The present invention relates to a capacitive touch panel and a method for manufacturing the same, in which the material having lower resistance than that of ITO is filled in the intaglio formed on the resin layer, which is patterned to form the embedded sensing electrode and the sensing electrodes and the wiring electrodes are formed at the same time by using the same resistance material; in which the capacitive touch panel includes a first sensing layer formed with a plurality of first direction sensing electrodes, which are patterned and a plurality of first wiring electrodes; and a second sensing layer formed with a plurality of second direction sensing electrodes, which are patterned and a plurality of second wiring electrodes; in which the first sensing layer and the second sensing layer are bonded in the mutual vertical direction.

A touch screen device means an input unit for performing the whole control of an electronic device; comprising controlling a display screen by sensing a touch point of user on the display screen and then using the information about the sensible touch point as input information.
The touch screen device uses a touch screen, such as a resistive touch screen, a capacitive touch screen, an ultrasonic touch screen, an optical (infrared) sensor touch screen, an electron inducing touch screen, and the like. They have different characteristics, such as signal amplification, a resolution, the level of difficulty of plan and process technology, and the like, according to each way. Therefore, the touch screen device has to reflect and select enough to be able to emphasize each way's advantage.
For specifically selecting a way, durability, an economic feasibility, and the like should be considered in addition to an optical property, a technical property, and an input property. Two representative ways from among these are the resistive way and the capacitive way. From among these, the capacitive touch screen that is applied to Mobile, MP2 device, Note Book, and the like, generally uses ITO (Indume Tin Oxide) transparency electrode.
FIG. 1a is a cross-sectional view of a touch panel including ITO material according to the prior art; FIG. 1b and FIG. 1c are processes for manufacturing a touch panel including ITO material according to the prior art, which are flow charts of a photo etching process and a screen printing process, respectively.
Referring to FIG. 1a, the touch screen using the capacitive way according to the prior art has poor touch sensitivity because sensing and motion sensors are formed by patterning ITO transparency electrode, so that it is not suitable for making a large area. In addition, an optical transmittance is not good and also visibility is bad due to the pattern of sensor electrode.
Referring to FIGS. 1b and 1c, the touch panel according to the prior art is manufactured by the photo etching process for forming a wiring and a pattern of ITO transparency electrode or a screen-printing process for forming a pattern of silver electrode.
In the case of the photo etching process, the process is complex and the cost of manufacturing is high due to a photolithography process. In the case of the screen-printing process, the process is difficult to accurately control so that it is difficult to maintain an accurate align tolerance between ITO and outer electrode part; a line width is difficult to finely implement so that there are many dead spaces; a crack may be generated on the ITO micro line width part due to the high-temperature drying; and the cost of ITO material is high so that the cost for manufacturing the touch screen and touch pad including ITO material is high.

Capacitive touch panel including embedded sensing electrodes


A motherboard is capable of accepting various types of fans from same or different manufacturers and is capable identifying the type of fan to which it is connected. In one embodiment, the motherboard is capable of decoding bar code data originating from a fan of the type which, rather than including circuitry for generating a single index pulse, includes an integral optical sensor and bar code pair for generating the bar code data, the motherboard being further capable of and identifying the fan based on the bar code data. Fan identification has a variety of uses including, for example, adjusting motherboard parameters to properly operate the fan based on the type of fan presently coupled to the motherboard. Additionally, fan speed may be calculated from pulses which are intended to identify the fan.

This invention pertains to circuit boards which provide enhanced features, and, more particularly, to a motherboard which provides a platform from which detection of fan type and control therefor is made possible.
Generally, computer system motherboards provide at platform on which a computer system can be built, and soldered thereto include various Large Scale Integration (LSI) chips and sockets for Very Large Scale Integration (LSI) chips such as a processor mounted thereon. The computer system, in turn, typically includes a storage device such as a hard disk, a battery device, and input/output devices. Each of these is known to generate heat as each operates in a computer. For some electrical components, such as a processor, a temperature range is often indicated by specifications which set a temperature range indicative of satisfactory and/or optimum performance (hereinafter, as used herein, this temperature and range may also be referred to as "rated temperature"), and often one or more cooling fans are typically provided in conjunction with electrical components in a computer system to keep the temperature in the system within the rated temperature.
A computer system motherboard may include multiple processor sockets, for attachment of multiple processors at the time a computer system is manufactured, or electrical components that each need to be cooled by a different cooling fan. The speed of each of these cooling fans may be controlled by a program embedded in the system Basic Input/Output System (BIOS) code. Typically, the speed of each of these fans is controlled by a pulse width modulated signal at an input terminal of the more modern fans, and by pulsing a supply voltage to the fan in older fans. The pulse supplied to the older fans may vary based on the width, amplitude and frequency of the pulse. These characteristics (PWM input, and power supply pulse width, amplitude and frequency) may all be used to control the speed of the cooling fan.
Cooling fans may be manufactured from different manufacturers and may include different designs that each has specific PWM characteristics or, in the case of older fans, supply voltage characteristic requirements for optimum performance.

Motherboard having advanced fan control features


Embodiments disclosed herein include a system that is capable of processing test data across multiple sessions of a video game. In some cases, the tests are performed over multiple video games that share a game engine. The generated test data may be analyzed as the test is being performed and key performance indicators may be extracted from the test data reducing the test data by at least an order of magnitude. Further, the extracted key performance indicators are used to automatically conduct further testing, such as regression testing, based on an analysis of the key performance indicators with respect to trend data generated from prior tests of the video game or of a shared game engine used by multiple video games.

Many video games are complex software applications that utilize a significant percentage of a computer system's resources. Each year the complexity of many of the latest video games pushes the boundaries of the latest computing systems. Modern video games comprise millions of lines of code. Testing the code of such large applications can be a time consuming and challenging process. Further, because video games are often programmed by teams of developers, changes made by one developer or team of developers working on one portion of the video game may impact code developed by another developer or team of developers working on another portion of the video game. Thus, code must often be tested and retested repeatedly as changes are made to the code by different teams.
Some video games are developed using a framework of reusable software components, which is sometimes termed a "game engine." Using the game engine to develop the video game can help reduce development time and resources required to create a video game because existing software components can be reused in the creation of the video game. However, learning to efficiently use the game engine can be challenging for new developers. Further, different types of video games may use the game engine in different ways. Thus, what may be the most efficient way to utilize the game engine for one type of video game may not be the most efficient way to use the game engine for another type of video game. Moreover, the game engine itself may evolve over time. Thus, a developer may need to learn new ways to optimize use of the game engine when developing a video game that uses a newer version of the game engine. For at least the above reasons, the incorporation of the game engine can add complexity to testing of a video game.

Automated cross-session video game testing


A computer-implemented method includes determining, at a set-top box device, positioning data associated with a location of the set-top box device. The computer-implemented method includes determining whether the set-top box device is authorized to receive media content at the location. The computer-implemented method also includes receiving the media content via a wireless transmission from a residential gateway when the set-top box device is authorized to receive the media content at the location.

Emerging wireless transmission technologies may enable a residential gateway to wirelessly transmit media content, such as video content, to a set-top box device. By doing so, the set-top box device may receive media content without the set-top box device being coupled to the residential gateway via a cable. However, when a residential gateway is used to wirelessly transmit media content to a set-top box device, an unauthorized set-top box device that is within a broadcast range of the residential gateway may receive the wirelessly transmitted media content.

System and method to determine an authorization of a wireless set-top box device to receive media content


Disclosed is a nickel layer formed on a substrate by sputtering, in which nickel layer a percent ratio of an X-ray diffraction peak intensity of the (200) plane of the nickel layer to that of the (111) plane of the nickel layer is not less than 10%. This nickel layer has a reduced stress, and therefore, lessens a bending of a substrate. The nickel layer is formed by a process for sputtering nickel on a substrate, comprising supplying an argon gas into a vacuum chamber, adjusting a pressure of the argon gas in the vacuum chamber to a predetermined value, ionizing the argon gas, bombarding a target containing nickel with the ionized argon gas, to sputter nickel atoms, and depositing the sputtered nickel atoms onto the substrate, wherein the predetermined pressure of the argon gas is not lower than 12 mTorr.

1. Field of the Invention
The present invention relates to a nickel layer deposited by sputtering and having a reduced stress, and a process for depositing such a sputtered nickel layer.
2. Description of the Related Art
A consecutive sputtering of titanium, nickel and gold layers onto a semiconductor substrate or wafer to form a laminated metal electrode, in which an argon pressure used during the sputtering is usually 2 to 10 mTorr, is known. This pressure range is adopted because, at a higher argon pressure, the electric resistivity of the deposited layer is high and the load on a vacuum pump becomes higher as the argon pressure is increased.
Nevertheless, in the conventional sputtering, a high stress occurs in particularly the deposited nickel layer, thereby bending the semiconductor wafer and reducing the adhesive strength of the deposited layers. Particularly, the bending of a wafer is a severe problem in an automatic manufacturing line, and wafers having a bend larger than 350 .mu.m cannot be transferred in the automatic manufacturing line and thus must be manually transferred.


A system for determining estimated navigation signal error information. Several error models are used by the evaluation unit, and, as a function of at least one defined selection standard, one of the several error models is selected. In determining the estimated navigation signal error information, the selected error model is applied to the received navigation signals, and the determined error information is transmitted to the radio navigation system and/or to user terminals.

This application claims the priority of German Patent Application DE 102 45967.3, filed Sep. 30, 2002, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to the problem of determining estimated navigation signal error information, in which case several receiver units receive navigation signals of at least one navigation signal transmission unit and at least one evaluation unit evaluates the received navigation signals. The navigation signal error information is finally transmitted directly or indirectly to user terminals of a radio navigation system so that the user terminals are informed on the basis of the error information, for example, of the precision of measurements which were carried out on the basis of received navigation signals. A radio navigation system can be implemented, for example, by means of terrestrial navigation signal transmission units or by means of navigation satellites or other aerodynamic vehicles as navigation signal transmission units.
From the state of the art, such measures are already basically known, as indicated, for example, in U.S. Patent Document U.S. Pat. No. 6,114,992. In order to determine navigation signal error information, according to the measures from the state of the art, one specific error model is used in each case which is applied to received navigation signals. This will be briefly explained using the example of satellite navigation systems. Concerning the corresponding state of the art, reference is made, for example, to the above mentioned U.S. Patent Document U.S. Pat. No. 6,114,992 as well as to S. P. Pullen et al., "Global Orientation of GPS Augmentation Architectures Using Genetic Algorithms", ION GPS-95, Palm Springs, Calif., September 1995, which can be retrieved in the Internet under:
http://einstein.stanford.edu/gps/PDF/global_optimize_spp95.pdf and to W. Werner, "Towards Global Integrity", International Symposium on Kinematic Systems, in Geodesy, Geomatics and Navigation, KIS 2001, Jun. 5–8, 2001, Banff, Canada, which can be retrieved in the Internet under:
http://www.ifen.com/publications/KIS2001_Paper.pdf
Position errors of the satellite position as well as clock errors of the satellite clocks may occur in the case of satellite navigation systems. In the prior art, the maximal projection of the position error and clock error of the individual signals in the application range of the navigation system so far have either been modeled as a scalar linear function of the longitude and latitude; as a scalar linear function of the North and East value in a plane reference system, in which the signal source is situated precisely in a normal manner over the origin of the reference system; as a maximal projection of the four-dimensional position error and clock error; or as a maximal of a three dimensional error with the first two components representing the error in the North or East direction and the third component representing the clock or altitude error. Thus, this third component assumes either a spatial or a time-related character which is defined once for the algorithm for determining the navigation signal error information. The scalar estimation has the disadvantage that it does not work for large coverage areas. The four-dimensional estimation has the disadvantage that clearly more observations are required than for the three-dimensional estimation. The three-dimensional estimations suggested so far have the disadvantage that the defining of the type of the third component has to take place a priori but the optimal character of the third component changes with the time and the user position. The estimation as a scalar linear function of the North and East value has the disadvantage that it frequently supplies a poorer error description than the two three-dimensional processes.
It is an object of the present invention to provide possibilities for determining estimated error information for navigation signals of at least one navigation signal transmission unit, which can be implemented with a very brief observation time and with as few receiver units as possible.
A first object of the present invention is a process of determining estimated navigation signal error information, in which case several receiver units receive navigation signals of at least one navigation signal transmission unit and at least one evaluation unit evaluates the received navigation signals. Furthermore, in the case of this process, a—direct or indirect—transmission of navigation signal error information takes place to user terminals of a radio navigation system. An indirect transmission may take place, for example, in that navigation signal error information is first transmitted to other devices —inside or outside the radio navigation system.
The process according to the invention is characterized in that the evaluation unit uses several error models with one of the models being selected as a function of at least one defined selection standard. The selected error model for determining the estimated navigation signal error information is applied to the received navigation signals and the determined error information is transmitted to the radio navigation system and/or to user terminals.
If the error information is first transmitted to the radio navigation system and not directly to the user terminals, suitable agents of the radio navigation system can take over the transmission of the error information to the user terminals in a manner known per se.
The invention has the advantage that, instead of a rigid selection of an error model, a flexible or even a dynamic selection of error models takes place. The selection of the error model can take place either at certain points in time or periodically, and therefore, in a time-event-controlled manner. However, it can also take place in a manner which is controlled by certain actual events or signalings.
The selection according to the invention of the error models ensures that the most suitable error model is selected, and that, in addition to the error estimation of the navigation signals, preferably also the corresponding error of the respective error estimation can be estimated and taken into account. Furthermore, as a result of the selection of the suitable error model, a sufficient precision of the process can be achieved also by means of a lower number of receiver units and, on the other hand, an error model can be selected which guarantees as few errors as possible for a range of an reception area for navigation signals which is as large as possible.
In particular, the process can be designed such that the error models have a first number of error components which all error models have in common, and have a second number of individual error components which are individually defined for each error model. Thus, the error models preferably do not differ in all error components but only in some components which can be alternatively selected, whereas other error components remain the same. Examples of such error components are the initially mentioned errors in the North or East direction and the clock or altitude error.
This process can also be further developed so that the individual error components occur as linear combinations of defined basic error components. Thus, in addition to the previously customary, initially mentioned pure error components, mixed error components may also be provided which result from basic error components. Such basic error components may be the previously customary, initially mentioned pure error components. Thus, for example, a mixed spatial/time-related error component can be formed from the previously customary, initially mentioned pure error components. It can therefore be provided that the basic error components comprise at least one spatial error component and at least one time-related error component. As a result, the variation possibility of the process and thus finally the accuracy can be further optimized.
In principle, any suitable standard can be used as the defined selection standard, which permits a determination of the error model in the desired manner.
For example, the variance of the estimated navigation signal error information on a reference grid in a defined reception area can be used as a defined selection standard. However, the sum of the amounts or of the squares of the estimated navigation signal error information at the locations of the receiver units can also be used as the defined selection standard. In another alternative, the maximum of the amounts or of the squares of the estimated navigation signal error information at the locations of the receiver units is used as the defined selection standard. However, the integral with respect to the amount or the squares of the estimated navigation signal information in the defined reception area can also be used as the defined selection standard. Finally, as an alternative, the maximum of the amounts or of the squares of the estimated navigation signal error information in the defined reception area can also be used as the defined standard.
The aforementioned selection standards represent some examples of suitable selection standards. However, this listing is not final, so that other selection standards may also be chosen within the scope of the present invention.
In order to achieve another degree of freedom when optimizing the error information, it may be provided that the estimated navigation signal error information is weighted in a local and/or time-related manner. Thus, it can, for example, be provided that the estimated navigation signal error information is weighted as a function of the density of the user terminals in the reception area. The weighting can also take place as a function of other factors.
Another object of the present invention is an evaluation unit for evaluating navigation signals of a radio navigation system. According to the invention, the evaluation unit includes an error model memory for storing error models for received navigation signals of the radio navigation system; a processing unit constructed for the selection of an error model as a function of a defined selection standard and for the application of the selected error model to received navigation signals; and a device for transmitting navigation signal error information to the radio navigation system and/or to user terminals.
The corresponding advantages of the invention occur analogously to the above-described advantages of the process according to the invention.
As indicated above, radio navigation systems can be constructed in different ways with the evaluation units being adapted correspondingly. Thus, for example, the evaluation unit can be constructed as an evaluation unit of at least one satellite navigation system. Furthermore, the evaluation unit can be constructed such that it is adapted for the implementation of individual or several of the above-mentioned process steps.
Another object of the present invention is a computer program for determining estimated navigation signal error information of a radio navigation system. The computer program is constructed for an interaction with devices of an above-mentioned evaluation unit. The computer program further being constructed for controlling the reading of several error models out of an error model memory; for selecting one of the several error models as a function of at least one defined selection standard; for determining the estimated navigation signal error information while applying the selected error model to the received navigation signals; and for controlling the transmission of determined error information to the radio navigation system and/or to user terminals.
Another object of the present invention is a computer program product containing a machine-readable program carrier on which an above-mentioned computer program is stored in the form of electronically readable control signals. The control signals may be stored in any suitable form with the corresponding electronic reading taken place by electric, magnetic, electromagnetic, electro-optical or other electronic methods. Examples of such program carriers are magnetic tapes, floppy disks, hard disks, CD-ROMs or semiconductor devices.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Process and apparatus for creation of estimated navigation signal error information


With an optical disc device for reproducing information from discs having a recording density different from one another, by means of laser light beams each having a wavelength different from one another, a provision is put in place to prevent data stored on a CD-R disc from being damaged by irradiating a short wavelength laser beam. A method for identifying discs disclosed by the present invention is to find out whether or not a disc in question is CD-R and the like by irradiating long wavelength laser light on the disc while the rotation of the disc is suspended, and otherwise to find out whether or not a disc is DVD and the like by irradiating short wavelength laser light on the disc. Shifting a focusing lens in the light irradiating axis direction of laser light by means of an actuator generates a focus error signal and an all light amount sum signal, the amplitudes of which enable the identification of discs.

The present invention relates to a method for identifying discs used in an optical disc device for recording/reproducing information on a variety of optical discs, each of which has a recording density different from one another, by irradiating laser beams of different wavelengths.
There has been existing an optical disc device whereby information is reproduced from such optical discs as CD, CD-R, CD-RW and the like by using a long wavelength (780 nm) laser beam and also information is allowed to be reproduced from optical discs such as DVD-5 and DVD-9, each of which has a recording density higher than the ones of the foregoing optical discs, by using a short wavelength (650 nm) laser beam.
However, there is a danger that the recording film of an organic pigment base as used with such optical discs as CD-R and the like may be destroyed when a laser beam with a short wavelength of 650 nm is employed. for reproduction of information from the optical discs. It is necessary to take a sufficient countermeasure to prevent the destruction of the recording film from occurring in order to cope with the foregoing problem and a highly accurate method for identifying discs is needed to deal with the above issue.
With an optical disc unit comprising: a first light source radiating a light beam with a first wavelength for reproducing information from a first optical disc; a second light source radiating a light beam with a wavelength shorter than the first wavelength for reproducing information from a second optical disc having a higher recording density than the recording density of the first optical disc; a convergent device operable to have the light beam of the first wavelength and the light beam of the second wavelength converge on the optical disc, respectively; and a light receiving device operable to receive reflective light from the first optical disc and reflective light from the second optical disc, the present invention provides a method for identifying discs comprising: irradiating the light beam of the first wavelength on the optical disc while the rotation of the optical disc being suspended; recognizing the existence of the first optical disc according to a signal received from the light receiving device when the focus lens of the convergent device is moved in the light irradiating axis direction to the optical disc; irradiating the light beam of the second wavelength on the optical disc while the rotation of the optical disc still being suspended when no existence of the first optical disc is recognized; and recognizing the existence of the second optical disc according to a signal received from the light receiving device when the focusing lens of the convergent device is moved in the light irradiating axis direction to the optical disc.
Thus, the destruction of the previously recorded information caused by irradiating a short wavelength (650 nm) laser beam on a CD-R disc that belongs to the first optical disc can be prevented from taking place.
Further, applying some modification to the foregoing method, when no existence of the first optical disc is recognized upon irradiating the light beam of the first wavelength, a signal received from the light receiving device is memorized and, in succession, the light beam of the second wavelength is irradiated, thereby having the existence of the second disc recognized by a signal received from the light receiving device and then having the foregoing signal memorized. By comparing the values of these two memorized signals, a reconfirmation of countermeasures against a malfunction becomes possible.
The foregoing method allows the CD-R disc belonging to the first optical disc to be identified again even when wrong identification has been made upon irradiating the light beam of the first wavelength, thereby achieving a further enhancement in reliability.

Matsushita Electric Industrial Co., Ltd.


A mobile terminal which includes a terminal body; a display mounted to the terminal body; a window disposed to cover the display and including central and edge regions wherein the central region is formed of a transmissive material and configured to align with the display, and the edge region is formed of an opaque material and configured to surround the central region. The mobile terminal further includes a first touch sensor disposed to span at least the central region and configured to detect a touch input to the central region; and a second touch sensor disposed to span at least part of the edge region and configured to detect a touch input to the at least part of the edge region, wherein the second touch sensor is configured to have a higher touch sensitivity than the first in order to detect a touch input to the opaque edge region.

1. Field of the Invention
The present invention relates to a mobile terminal, and particularly, to a mobile terminal having a touch sensor.
2. Background of the Invention
A mobile terminal is a device that can be carried around and has one or more functions such as to perform voice and video call communications, inputting and outputting information, storing data, and the like.
As functions of the terminal become more diversified, the terminal can support more complicated functions such as capturing images or video, reproducing music or video files, playing games and receiving broadcast signals. By comprehensively and collectively implementing such functions, the mobile terminal may be embodied in the form of a multimedia player or a device.
Various attempts have been made to implement complicated functions in such a multimedia device by means of hardware or software. For instance, input by touch is being provided, in order to implement a convenient user interface (UI) with a simpler appearance.
In a case where an opaque edge region of a window, e.g., a touch key, is touched, touch sensitivity on the edge region is lower than that on a central region corresponding to a display. The reason is because the edge region has undergone a printing process for an opaque characteristic, or a light-shielding tape has been applied to the edge region, etc.
In the case of touching the edge region using a user's hand, the touch can be recognized because the hand has high electrostatic capacity. However, in case of touching the edge region using a stylus pen having low electrostatic capacity, the touch input may not be recognized.
In order to solve such problems, sensitivity of a touch sensor may be increased. However, in this case, touch sensitivity on the window corresponding to the central region becomes too high. This may cause a hovering phenomenon where touch input is detected before the window is touched.


A fixture for securing a pin grid array (PGA) and grounding all circuits or pins in the PGA for electrolytic plating provides a series of parallel wires that are inserted between every other gap between the PGA pin rows. The cross section of each wire is constructed to provide a first cross sectional width at one location that is less than or equal to the PGA gap width for insertion into the PGA gap and a second cross sectional width, at an angle to the first cross sectional width, that is greater than the gap width. With this arrangement, the wire can be inserted in the gap with the first cross sectional width traversing the gap and then rotated to bring the wider, second cross sectional width into spreading engagement with the pins for a reliable mechanical and conductive contact.

A typical multi-layered substrate assembly, which is also referred to as a Pin Grid Array (PGA), has a multitude of individual circuits within it. In order to plate the exposed pins and solder pads by electrodeposition, it is necessary to electrically short each pin or circuit to the cathode. A number of techniques are currently used to accomplish this purpose.
In one method, known as tie-bar plating, a branch is designed into each circuit and leads to an edge of the substrate. A plating fixture can be constructed to short the circuits through a grounding contact with one or more edges of the substrate. This approach requires an array of parallel conductors leading to the edge of the substrate from each of the circuits in the assembly. For high speed integrated circuit devices, these parallel conductors form antennas that can cause noise within the substrate assembly during operation. This method is therefore not useful for high speed devices.
In certain PGA's, such as multiple chip modules, some circuits are connected to each other in a pad-to-pad connection and do not utilize a pin. Accordingly, some pins are not electrically connected to the substrate edges. These floating pins are not grounded and therefore do not get plated in a substrate-based tie-bar plating process.
In other methods, such as through-pin plating, a fixture makes contact with the ends of the pins. In PGA's in which every circuit terminates at at least one pin, every circuit element is thus shorted to a common point. The grounding element for contacting each of the pins, however, covers the pin side of the substrate assembly and restricts the flow of the plating bath. The result is that the plate thickness is typically thicker around the edges of the substrate than in the center. These contacting elements are also generally expensive and difficult to construct.
In interstitial pin arrays, each row of pins is staggered relative to each other so that each pin of a row is transversely aligned with a space in each of the adjacent rows of pins. Interstitial pin arrays generally provide more circuits, and the plating difficulties noted above are further extenuated.

Method and apparatus for fixturing substrate assemblies for electrolytic plating

International Business Machines Corporation


An acetabular reamer includes a base, a first set of semi-circular blades attached to the base, and a second set of semi-circular blades also contacting the base, and crossing and intersecting with the first set of blades at right angles thereto. The base preferably includes a circular plate having a hexagonal drive hole in the center thereof and a plurality of slots in the periphery thereof for anchoring the blades. Each semi-circular blade includes a first end having a projection thereon, a second end opposite from said first end and also having a projection thereon, a first edge having serrated cutting teeth thereon, a second edge opposite from said first edge, and a first and second side surface. The cutting edge of the first set of blades includes a plurality of outwardly facing slots which mate with and engage a second set of inwardly facing slots in the second edge of said second blades. When the first and second set of blades are assembled in this fashion the cutting edges of both sets of blades lie in the same spherical plane. The projections can include snap-in projections that automatically lock in position or projections that can be twisted and locked into position. Alternatively, the base can comprise a pair of upper and lower plates with apertures in the upper plate such that when the blade projections mate with the apertures, riveting of the lower plate with respect to the upper plate locks the projections and their related blades into position on the base. When the reamer is assembled it has a hemispherical shape suitable for reaming the acetabulum of the hip so that the acetabular portion of a hip implant properly fits into the acetabulum.

1. Field of the Invention
The invention relates to a multi-blade acetabular reamer and a method for constructing the same.
2. Description of Related Art
The prior art patent literature describes a few reamers and cutters for removing bone and tissue from joints that may be relevant to the state of the art. For example, U.S. Pat. No. 4,621,637 entitled "SURGICAL DEVICE FOR REMOVING BONE AND TISSUE FROM JOINT MEMBERS" teaches a slotted, surgical device including a hemispheric housing that supports one or more cutting blades for bone and/or tissue cutting. Two and three blade embodiments are described. In both cases, the blades abut centrally of the device and interlock with the base at discrete points.
French Patent 1,031,888 describes a plurality of cutting blades which are radially disposed, equiangularly spaced atop a supporting plate and locked to the plate by fasteners. The resulting tool is used for cutting the acetabular portion of a hip prior to joint replacement.
Similarly, French Patent 1,041,311 describes a bone cavity forming tool which employs multiple blades in a hemispheric array.
Soviet Union Patent 1225-543-A entitled "BONE CUTTING TOOL FOR SURGERY" describes a cutter comprising multiple arcuate cutting elements extending from a central rod outwardly in an umbrella fashion.
French Patent 2,233,972 entitled "ARTIFICIAL HIP JOINT FITTING EQUIPMENT" describes another multi-blade, round headed milling cutter for acetabular application.
U.S. Pat. No. 5,222,959 entitled "REMOVAL OF TISSUE" describes a soft tissue cutter having an oval, rather than hemispheric, shape.
U.S. Pat. No. 5,192,291 entitled "ROTATIONALLY EXPANDABLE ATHERECTOMY CUTTER ASSEMBLY" describes another soft tissue cutter in which the blades define a cylindrical, not hemispheric, structure.
U.S. Pat. No. 5,100,267 entitled "DISPOSABLE ACETABULAR REAMER CUP" describes a hemispheric, cup-shaped hip reamer. With regard to this structure, note also U.S. Pat. Nos. 5,116,165 and 5,376,092.
The following U.S. Patents describe prior art bone reamers of possible interest, using multi-blade configurations, but for non-hip applications: 3,554,192; 5,122,134, 5,180,384 and 5,318,576.
Lastly, U.S. Pat. No. 3,633,583 entitled "ORTHOPEDIC SINGLE-BLADE BONE CUTTER" is of general relevance only.
While a few joint reamers are known in the prior art, they tend to be expensive, or hard to construct, or both. There clearly appears to be a need for a safe, easy to assemble, inexpensive and effective reamer especially for the acetabulum of the hip. Insofar as understood, none of the prior art known to the inventor, whether taken individually or in combination, hints, teaches or suggests the novel acetabular reamer disclosed herein.


Provided are a semiconductor integrated circuit including a unit which detects soft defects in a pull-up circuit of a static memory cell, and a soft defect detection method and a testing method thereof. The semiconductor integrated circuit includes a static memory cell, a bit line connected to a first node of the static memory cell and a complementary bit line connected to a second node of the static memory cell, and an equalization circuit connected to the bit line and the complementary bit line to equalize the bit line and the complementary bit line in response to a test signal during a test mode. The semiconductor integrated circuit and the soft defect detection method can rapidly detect soft defects in the pull-up circuit of the static memory cell without a retention test. Furthermore, the testing method can rapidly detect soft defects in the pull-up circuit of the static memory cell, allowing the test time to be drastically reduced.

1. Field of the Invention
The present invention relates to a semiconductor integrated circuit, and more particularly, to a semiconductor integrated circuit comprising a unit which detects soft defects in a static memory cell, a method of detecting soft defects, and a method of testing the semiconductor integrated circuit for soft defects.
2. Description of the Related Art
Many complementary metal oxide semiconductor (CMOS) static random access memorids (SRAMs) utilize four transistors per memory cell. However, due to some advantages, a six transistor cell approach is gaining in popularity. These advantages include higher operational stability, higher alpha-particle immunity, and a simpler process.
A primary disadvantage of the six transistor memory cell CMOS SRAM is that open circuit failures in a pull-up circuit of the memory cell can appear as soft defects. Because such faults do not result in a hard failure, testing and failure analysis have proven to be particularly difficult. A method of testing a CMOS SRAM device for soft defects in a pull-up circuit is disclosed in U.S. Pat. No. 5,361,232.
FIG. 1 is a schematic diagram of a modeling circuit of a conventional six 30 transistor static memory cell. FIG. 2 is a schematic diagram of a semiconductor integrated circuit including a plurality of static memory cells shown in FIG. 1.
Referring to FIG. 1, in the six transistor static memory cell, resistors R1, R2 and R3 are located between a power voltage VDD and pull-up transistors MP1 and MP2, and resistors R4 and R5 are located between the pull-up transistors MP1 and MP2 and internal nodes D and DB. Resistors R8, R9 and R10 are located between a ground voltage VSS and pull-down transistors MN3 and MN4, and resistors R6 and R7 are located between the pull-down transistors MN3 and MN4 and the internal nodes D and DB. Typically, the pull-up transistors MP1 and MP2 act as load transistors and the pull-down transistors MN3 and MN4 act as drive transistors.
Referring to the circuit diagram of FIG. 2, during a read operation, when a precharge signal PCH is initially at a logic "L", PMOS transistors 211, 213, and 215 within a precharge circuit 21 are turned on and a bit line BIT and a complementary bit line BITB are precharged to a power voltage VDD.
Next, when the precharge signal PCH is at a logic "H" and accordingly, the PMOS transistors 211, 213, 215 within the precharge circuit 21 are turned off and one of word lines WL1 through WLn is activated to a logic "H", one of memory cells M1 through Mn is selected and data D and complementary data DB stored in the selected memory cell are output to the bit line BIT and the complementary bit line BITB, respectively.
After a suitable time delay, a sense enable signal SAEN is activated to a logic "H", and a sensor amplifier 23 senses and amplifies a voltage difference between the bit line BIT and the complementary bit line BITB and outputs the result as output data.
If soft defects exist in the pull-up circuits of the memory cell, that is, if leakage current continuously flows to a node having data "1", for example, the node DB, or if the resistances of the resistors R1 through R5 increase for some reason and thus a sufficient amount of current is not applied to the node DB having data "1", the node DB gradually discharges. That is to say, the voltage level of the node DB gradually decreases. As a result, when the voltage of the node DB exceeds a logic threshold voltage of an inverter within the memory cell, data stored in the memory cell are toggled.
For the purpose of screening memory cells having such soft defects, a retention test is typically run. However, the time taken to discharge the node DB is so long that the retention test time needs to be of very long duration in order to detect the defects.

Semiconductor integrated circuit and method for detecting soft defects in static memory cell


An object of the present invention is to provide a novel pyrroloquinoline quinone disodium crystal having excellent dispersibility in solvents and excellent permeability through skin, and a method for producing the pyrroloquinoline quinone disodium crystal with high efficiency. According to the present invention, provided are a novel pyrroloquinoline quinone disodium crystal which is produced by drying a crystal produced under specified conditions through a drying means such as lyophilization, ambient drying and vacuum drying, and a method for producing the pyrroloquinoline quinone disodium crystal.

Pyrroloquinoline quinone (hereinafter sometimes referred to as "PQQ") has been proposed as a possible new vitamin (see, for example, Non-patent document 1). Moreover, PQQ is present not only in bacteria but also in eukaryotic molds and yeasts and plays an important role as a coenzyme. Also, PQQ has been found to have many physiological activities such as cell growth-promoting activity, anti-cataract activity, hepatic disease-preventing and therapeutic activity, wound healing activity, anti-allergic activity, reverse transcriptase-inhibiting activity, glyoxalase I-inhibiting activity and anticancer activity, and the like. PQQ has thus attracted much attention as a useful material in the fields of pharmaceuticals, foods, and cosmetics. In the field of pharmaceuticals, PQQ is expected to be applied as therapeutics for cardiac diseases (Patent Document 1), dermatoses (Patent Document 2), and neurodegenerative diseases (Patent Document 3), for example. PQQ is also expected to be applied as a substance that has an anti-aging effect in the field of foods and that has a skin-beautifying effect in the field of cosmetics.
PQQ can be produced by methodologies such as organic chemical syntheses and fermentation processes and is often provided in the form of an alkali metal salt crystal, in particular a disodium salt crystal (hereinafter sometimes referred to as "disodium crystal"). The PQQ disodium crystal is in the crystalline pentahydrate form, and single crystal analysis has revealed the structure of the disodium crystal (Non Patent Document 1). In addition to the method described in Non Patent Document 1, reported methods for producing the PQQ disodium crystal include pH adjustment of a solution of PQQ disodium to crystallize PQQ disodium (Patent Document 4) and precipitation using an aqueous organic solvent to precipitate the PQQ disodium crystal from the aqueous solution (Patent Document 5). Any of these methods, however, produces a solid having a low degree of crystallinity or uses an inedible solvent. In addition, the crystal produced does not always have a high preservability.
When applied to pharmaceuticals and cosmetics, PQQ is desired to have a high degree of crystallinity, contain few impurities, have a stable solubility or a high dispersibility in a solvent, and have a high degree of preservability. When applied to foods and pharmaceuticals, PQQ is also desired to be harmless to the human body. When applied to skin pharmaceuticals and cosmetics, PQQ is further desired to have a high degree of permeability through the skin.

Pyrroloquinoline quinone disodium salt crystal and method for producing the same


A detector and detection method for identifying unknown chemical solutions following chemical spills includes a specific gravity detector including a detector column having an inlet end operable to collect a sample of a solution, wherein the detector column is formed of an optically transparent material to allow visual observation of the sample in the detector column. At least a first plurality of specific gravity floats including a first specific gravity float is located and moveable within the detector column, wherein the first specific gravity float has a density to float in liquids having a specific gravity of greater than a first density level. At least a second specific gravity float is located and moveable within the detector column, wherein the second specific gravity float has a density to float in liquids having a specific gravity greater than the first density level. A sample of an unknown solution from a site of a chemical spill is introduced into the detector column. A float response of the first plurality of specific gravity floats is observed and based on the observation a presence or absence of at least one chemical solution in the unknown solution is identified.

Although chemical spills are somewhat common in semiconductor manufacturing, they are, for the most part, identifiable and safe to mitigate with proper personal protective equipment [PPE]. It is those times, when the chemical is non-detectable, that can be hazardous. The hazards resulting from a spill depend on variables that include the spilled material's chemical and physical properties, location, and quantity.
Some chemicals are difficult to detect even from a list of commonly available detectors, particularly those which are colorless, have low vapor pressure, and have a near neutral pH. Hydrogen fluoride (HF) readily dissolves in water to form colorless, extremely corrosive hydrofluoric acid solutions. HF solutions are visibly indistinguishable from water. However, HF solutions can be detected with a variety of detectors. In semiconductor manufacturing, HF solutions are commonly used for oxide etching, including solutions such as so called buffered HF (BHF). BHF is a neutral solution and generally comprises 40-45% Ammonium Fluoride; 0.49% Hydrofluoric Acid, with the remaining balance being water. BHF is thus an example of a chemical solution that is non-detectable outside a laboratory setting, even from a list of commonly available field detectors, since BHF is colorless, has a low vapor pressure, and has a neutral pH.
HF solutions are extremely hazardous. Such solutions can cause severe injury to any tissue with which it comes in contact (chemical burn). Exposure by contact with skin, or by inhalation or ingestion, can lead to severe toxic systemic effects (Acute Fluoride Intoxication) and potentially death. Death can occur from severe electrolytic imbalance (hypocalcemia and hypomagnesaemia) that leads to cardiac arrhythmia (fibrillation), which, in turn, can lead to cardiorespiratory arrest and multiple organ failure (kidney and liver).
HF is also easily absorbed by tissue, penetrating and then rapidly dissociating into Hydrogen and Fluoride. HF is highly corrosive and will destroy tissue, but the fluoride ion will also migrate through, and continue to damage bone. The disassociated fluoride ion will continue reacting to create fluorinated salts, which can cause serious toxic systemic effects. Washing the exposed tissue with water does not neutralize or stop the reaction, which limits the benefits of water washing (decontamination). HF-specific first aid treatments bind the fluoride to calcium, and rapidly starting such treatments is critical to stopping further tissue and bone damage. What is needed is a low cost, portable detector adapted for identifying the presence of certain target chemical solutions from unknown solutions, such as BHF solutions.

Portable solution detector for identifying chemical solutions including from chemical spills


A method and system is described for more optimally managing the usage of a wideband space-time multipath channel. The wideband space-time multipath channel is decomposed into a plurality of orthogonal sub-channels, where the orthogonal sub-channels having the best signaling characteristics are used for transmitting one or more signal streams. For purposes of decomposing the wideband space-time multipath channel into a plurality of orthogonal sub-channels, channel estimates are determined for each signal propagation path. A closed-form singular value decomposition of the channel corresponding to each receive antenna before coherent combining is utilized to obtain an orthogonal decomposition of the overall effective space-time channel after coherent combining. By using the overall effective space-time channel after coherent combining rather than before coherent combining, the complexity and correspondingly the resources required for obtaining the orthogonal sub-channels is significantly reduced. The method and system further provide for transmit power to be allocated between the selected sub-channels in order to minimize the effective bit-error rate for a fixed average throughput or to maximize average throughput for a fixed minimum effective bit-error rate.

1. Field of the Invention
The present invention relates to communication of one or more data signal streams over a wideband space-time multipath channel, and more particularly to the decomposition and selection for use of one or more sub-channels within the multipath channel.
2. Description of Related Art
The use of wireless communications has grown significantly over the past several years. With it the need to make better utilization of the available spectrum, which is allocated for use in wireless communications, has similarly grown.
In order to support multiple private two-way communications, the available spectrum is generally divided into a plurality of minimally and/or non-interfering sub-channels which are then dynamically allocated between users on a per request basis. Several techniques have been used to improve the utilization of the available spectrum, including improvements in frequency division, signal modulation, and spatial division.
Improvements in frequency division techniques have enabled a greater number of subchannels to be defined in the allotted spectrum by allowing the available frequency to be divided into narrower distinct slices or frequency bands. Improvements in signal modulation techniques including signal compression, time division multiplexing and spread spectrum techniques, such as code division multiple access, have enabled enhancements in both signal quality and channel capacity. Improvements in spatial division techniques which have traditionally included creating localized transmission areas, or cells, and other techniques for geographically restricting signal transmissions, have enabled frequency to be reused in geographically distinct and non-adjacent areas.
More recently spatial division techniques have begun to take advantage of inherent constructive and destructive interfering signal patterns between similar signals originating from or received by multiple spaced apart antennas to more narrowly define a signal region between which a signal is being transmitted or received. In this way signal patterns can be defined in such a way so as to focus a signal transmission within a select portion of a given geographical area by maximizing the strength of the signal directed toward an intended recipient, while minimizing the strength of the signal directed toward non-intended recipients for which the signal might create unwanted interference.
In addition to inherent constructive and destructive interfering signal patterns between signals originating from or received by multiple spaced apart transmitting and receiving antennas, constructive and destructive interfering signal patterns are also created by signals which travel between a transmitter and receiver via multiple signal paths. Multiple signal paths can result from signals which reflect off of one or more structures located between a particular transmitter and receiver as the signal radiates outward. In many instances the reflection of a signal can cause that portion of a signal's energy to be deflected in a manner so as to never be received by the receiver. In other instances a portion of the signal's energy could reflect off of one or more interfering surfaces and be redirected back towards the receiver. Regardless, various portions of a signal often reach their destination via one of a couple of different signal paths. A signal reaching its destination along different paths will often result in the different components of the signal arriving at a different angle and/or arriving at a different time.
In the past, the reception of the same signal at different times was generally destructive in nature and seen as another source of noise known as inter-symbol interference Inter-symbol interference resulting from reception of the same signal at different times due to signal propagation along different paths, generally created a limit on the rate at which data symbols could be transmitted. However more recent techniques have recognized that this inter-symbol interference if accounted for could also be used to enhance signal transmissions, once the transmission characteristics between the two points are known. One such technique includes the use of space-time beamformer technology.
However one of the complications associated with implementing a spatially distinct transmission which constructively combines the multipath signaling characteristics is the amount of computational resources required to compute the transmission requirements and reception requirements for establishing such a geographically discriminating communication connection. The amount of computational resources required for maintaining a spatially distinct transmission is further complicated by the fact that in many wireless communication applications, the transmitter and the receiver are in motion with respect to one another, and/or the objects against which the signal is being reflected are moving with respect to the transmitter and/or the receiver. Consequently, the transmission requirements and reception requirements may need to be recalculated or updated to take into account the continuously changing environment within which the desired communications are taking place, thereby making even greater demands upon the computational resources available for maintaining the quality of communications.
It would therefore be desirable to provide a method for managing the usage of a space-time channel and a channel state processing unit, which reduces the computational resources required for maintaining a spatially distinct transmission including those which make use of space-time beamformer technology.
These and other objects, features, and advantages of this invention are evident from the following description of a preferred embodiment of the present invention, with reference to the accompanying drawings.

Channel aware optimal space-time signaling for wireless communication over wideband multipath channels


A communication method for collective operations is provided which eliminates the need for a three layered structure. Instead, the method of the present invention employs a control structure which is specifically designed to keep track of the progress of the collective communication operations and the facilities for the handling of asynchronous message passing. The method of the present invention thus eliminates the need for an intermediary, point-to-point communication layer that is required to follow message matching semantics for sending messages, receiving messages and for awaiting message arrivals. Application layer tasks and user defined programs running in the communication layer share access to the control structure as a mechanism for synchronizing and scheduling the progress of the collective communication operation.

In order to provide useful background information to better frame the environment in which the present invention is employed, consideration is given to what is most likely viewed as the paradigm application in which collective operations are performed. Accordingly, attention is directed to the calculation of the largest one of a large set of numbers. The set of numbers is divided up and they are parceled out to a number of independent data processing units each one of which is capable of determining a maximum value for the set of numbers that it has been given (either directly or by the passage of a boundary address for a subset of the whole set of numbers). Clearly, this is the type of operation that can be parceled out again to another set of data processing nodes. The net result is that operations of this sort, referred to as collective operations, are ones that parceled out with data moving down a structured tree of processing elements and with resulting data being passed back up the tree. In the basic example illustrated herein, each node in the tree computes a maximum value for the set that it has been assigned and returns that result to the node from which it received the data, further up the tree (a tree root at top picture being assumed so as to make sense of the use of the word "up"). That node then picks a maximum value from the set of data returned to it and, in turn, passes that result further up the tree. Such is the basic nature and function of so-called collective operations. While this example illustrates the general principles and justifications for the use of collective operations, it should be noted that, in general, the data that is passed up and down the branches of a tree structure is often of a significant size and is not limited to a single number. It is often numeric, however, and often has a specific structure. The present invention is directed to structures and processes which underlie collective operations.
Collective communication operations play a very important role in high performance computing. In collective communication, data are redistributed cooperatively among a group of processes. Sometimes the redistribution is accompanied by various types of computation on the data and it is the results of the computation that are redistributed. The de facto message passing programming model standard, namely the Message Passing Interface (MPI) defines a set of collective communication interfaces, including MPI_BARRIER, MPI_BCAST, MPI_REDUCE, MPI_ALLREDUCE, MPI_ALLGATHER, MPI_ALLTOALL etc. These are application level interfaces and are more generally referred to as APIs. In MPI, collective communications are carried out on communicators which define the participating processes and a unique communication context.
Functionally, each collective communication is equivalent to a sequence of point-to-point communications, for which MPI defines MPI_SEND, MPI_RECEIVE and MPI_WAIT interfaces (and variants). MPI collective communication operations are implemented with a layered approach, that is, the collective communication routines handle semantic requirements and translate the collective communication function call into a sequence of SEND/RECV/WAIT operations according to the algorithms used. The point-to-point communication protocol layer guarantees reliable communication. A communication protocol stack often consists of several layers, each provides certain functionality and service to a higher layer. The MPI point-to-point layer itself is sometimes built on other point-to-point communication layers, some of which are not of the two sided communication model. One such example is the IBM Parallel Environment/MPI and IBM LAPI (a Low-level Application Program Interface set of definitions and functions). The MPI point-to-point communication layer in IBM PE/MPI is called Message Passing Client Interface (MPCI), which is built on top of point-to-point active message functionalities provided by the IBM Low-level Application Programming Interface (LAPI). LAPI consists of interfaces for the source side of the data making transfer requests and handler interfaces for upper layer functionality to be carried out by LAPI on its behalf. There are three types of handlers in LAPI, including send side completion handler, receive side header handler and receive side completion handler. The collective communication operations in IBM PE/MPI interfaces with MPCI, which in turn interfaces with IBM LAPI.
Despite its advantages, the layered approach has performance issues, one of which is the locking overhead in a threaded environment. A lock is required for each layer to protect its internal data structure. Multiple lock/unlock costs are paid when control goes through multiple layers. In the above example, to complete a collective communication operation, the MPI layer of IBM PE/MPI may make multiple calls to the MPCI layer, each one resulting in a LAPI function call and each requiring the following sequence:                MPI processing;        releasing the MPI lock;        acquiring MPCI lock;        MPCI processing;        releasing MPCI lock;        acquiring LAPI lock;        LAPI processing;        releasing LAPI lock;        reacquiring MPCI lock;        MPCI processing;        releasing MPCI lock; and        requiring MPI lock;
Another issue is that the interfaces provided by a two-sided, point-to-point communication lower layer (for example, MPCI) are generic and may not be convenient to serve certain special requirements of a particular upper layer. The MPCI protocol complies to the MPI point-to-point communication semantic which sometimes complicates things more than necessary. One of these cases is transferring a large message involved in collective communication operations. To send a large message in standard mode, MPCI implements the rendezvous protocol in which the sender sends a "message envelop" to the receiver and waits for the receiver's signal on sending the data. This can add substantial overhead and increase implementation complexity. In collective communication, the message envelope is not required to be delivered to the receiver for message matching purpose when "send" is posted before the receive. Message matching semantics enforced by the two sided point-to-point communication interface is not necessary for collective communication operation. Another example is the implementation of MPI_Reduce. MPI_Reduce combines inputs from all participating processes, using a combine operation specified through the interface, and returns the results in a receive buffer of one process (called the root of the reduce operation). The task that performs the reduce operation needs to receive some inputs from other tasks. With the point-to-point send/receive protocol, temporary buffers are allocated and extra copies are used to store those inputs at the MPI layer before carrying on the reduce operation. A third example is a small message MPI_Bcast where the message available at one process (referred to as the root) is transferred to all of the other participating processes. Implementation of MPI_Bcast is often based on tree algorithms in which the message is sent from the root of the tree to internal nodes of the tree and then forwarded along the branches. With the point-to-point send/receive protocol, a node can only receive the message after all nodes along the branches from the root to the node made the bcast call. Delay at any internal node in calling beast delays the completion of the beast at the downstream nodes along the branch.
In the process shown in FIG. 1, this is shown using the layered implementation of MPI_Barrier as an example. The algorithm for BARRIER requires log N round of communications by each process (logarithms are assumed to be base 2). During round j, process i sends a 0 byte message to process ((i+2j) mod N) and receives a 0 byte message from process ((i+N−2j) mod N). A message consists of an envelope and a payload of user data. Messages without user data payloads are referred to as "0 byte messages." These may also be referred to as "control messages" or "zero payload messages." The "send" in a new round cannot start until the receiver of the previous round completes. At MPI level, the algorithm is implemented by a loop of nonblocking mpci_recv and blocking mpci_send calls followed by mpci_wait to make sure the mpci_recv completes. MPCI calls LAPI_Xfer to send messages and loops on calling LAPI_Msgpoll for message completion. MPCI registers the generic header handler, the completion handler and the send completion handler for message matching and other two-sided point-to-point communication semantics.

Reducing layering overhead in collective communication operations

International Business Machines Corporation