Interference in a high speed receive signal is effectively detected in a TDMA communications system wherein a plurality of time slots is provided within a TDMA frame. A comparator is arranged to receive a first signal indicative of receive signal strength and a reference level signal. The comparator compares the magnitudes of the two signals applied thereto and outputs a comparison result signal. A delay circuit is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame. A gate circuit, preceded by the comparator and the delay circuit, is supplied with the outputs of the comparator and the delay circuit. The gate circuit outputs a third signal which changes a logic level in the event that the strength of the first signal exceeds that of the reference level signal during the time slot which is not in use.

1. Field of the Invention
The present invention relates to an arrangement and method for detecting an interference in a receive signal in a TDMA (Time Division Multiple Access) communications system.
2. Description of the Prior Art
TDMA techniques, in addition to the current extensive use thereof in satellite communication arrangements, have recently assumed an important role in mobile communications systems.
While the present invention will be discussed in connection with a TDMA mobile communication system, it will be understood that it may also be applied to a TDMA satellite communications system without departing from the concept underlying the instant invention.
In a TDMA mobile communications system, plural mobile units located within a given service area are respectively allowed to communicate with a land site using allocated time slots of each consecutive TDMA frame. The time slot used by a given mobile unit has therefore the same period as the TDMA frame.
In the event that a land site detects a predetermined number of interferences in a receive signal(s) within a given time duration, it is necessary to change the data carrier frequency currently in use to another one to avoid communication degradation.
Before turning to the present invention it is deemed preferable to discuss a known arrangement for detecting the presence of interferences in a receive signal(s) in a TDMA mobile communications system.
FIG. 1 is a block diagram schematically showing a land site 6 which includes a known interference detecting arrangement. The portions of the land site 6, which are deemed irrelevant to the instant invention, are not shown for the sake of brevity.
In FIG. 1, a plurality of mobile units Ma-Mn are located within a service area which is covered by the land site 6. A receiver 10 which forms part of the land site 6 is supplied, via an antenna 12 and a duplexer 14, with a burst signal(s) transmitted from one or more of the mobile units Ma-Mn. The receiver 10 demodulates the incoming burst signal and subsequently outputs a corresponding base band signal S8. A transceiver control section 8 includes a transceiver controller 16, a sampling circuit 18 and a microcomputer 20. The base band signal S8 is applied to the transceiver controller 16 via a line L8. A transmitter 22 is interconnected between the transceiver controller 16 and the duplexer 14 as shown.
The sampling circuit 18 receives a signal S10 from the receiver 10. The signal S10 is generated at an IF (Intermediate Frequency) stage (not shown) of the receiver 10 and indicates electric field strength of each of the signals in the time slots of the TDMA frame. The sampling circuit 18 samples the signal S10 in synchronism with a clock CLK applied thereto from the transceiver controller 16. The clock CLK comprises a train of pulses each of which is generated in synchronism with time slots of a TDMA frame. The sampling circuit 18 applies, via a line L14, the output thereof (viz., sampled data) S12 to the microcomputer 20. The microcomputer 20 includes a ROM (not shown) for storing a program dedicated to detecting the interference in the receive signals.
In more specific terms, the land site controller (not shown) informs, via a line L16, the transceiver controller 16 of the overall use of the time slots of a TDMA frame. This information which indicates the current use of the time slots is also applied to the transmitter 22 as a signal S14 over the line L11. The transmitter 22 receives a base band signal from the transceiver controller 16 via the line L10 and implements time slot data transmission using the signal S14.
The microcomputer 20 receives the output signal S12 via the line L14 and also receives the information indicating the current use of the time slots via a line L12. This information applied to the microcomputer 20 via the line L12 corresponds to the signal S14. Following this, the microcomputer 20 checks to see, using the program stored in the ROM therewithin, whether or not the output signal S12 is detected within the time slot not in use. If this happens, interference in the data communication channel currently used is indicated. The microcomputer 20 advises the transceiver controller 16 of the presence of interference. Further, the land site controller is advised of the detection of interference from the transceiver controller 16, and changes the communication channel to another one if necessary. The manner in which the current carrier frequency is changed to a new one is not directly concerned with the present invention, and hence will not be discussed in detail for the sake of brevity.
With the recent trend in high speed data transmission in a TDMA communications system, the above-mentioned prior art has encountered the problem in that the detection of the interference is extremely difficult or nearly impossible through the use of software. The reason for this is that the speed with which the interference detection routines can be executed are limited and are often unable to follow the high speed incoming data.

Arrangement and method for detecting interference in TDMA communications system


A payment integrated loyalty system including a point of sale terminal comprising a card reader, a communication subsystem configured to wirelessly communicate with a payment instrument, and configured to communicate over a network with at least a first and second server. The payment integrated loyalty system includes a processor in communication with the communication subsystem and card reader, configured to receive, through the communication subsystem, a payment instrument identifier associated with the payment instrument, and obtain a fingerprint based on one-way encrypting the payment instrument identifier. The processor is further configured to receive, from the first server via the communication subsystem, a loyalty balance associated with the fingerprint and to complete the financial transaction based on an updated amount based on the loyalty balance.

Loyalty systems allow a customer to accrue loyalty for purchases or engagement with a retailer or service provider. These loyalty systems provide a way for a merchant to establish a one-to-one mutually advantageous relationship with a customer. In conventional systems, the customer makes a decision to join a merchant's loyalty program and is issued a loyalty card number that uniquely identifies the customer (or "member" once they have joined the loyalty program) in the context of that merchant. The loyalty card number is carried by the member on either a physical card or an electronic card. When making purchases at any of the merchant's locations the member identifies their participation in the loyalty program by submitting their loyalty card number to the merchant before or during a payment transaction. The merchant's loyalty systems software will then accumulate points or loyalty for that member and/or provide the member an opportunity to redeem points or loyalty if applicable. Some merchants may make use of members' mobile phones to enable loyalty features via an application or app, or electronic wallet (e-wallet) card.
However, these existing loyalty systems are based on the customer having to keep a separate loyalty card number or load a dedicated loyalty application on their mobile phone. As well, many of these existing loyalty systems are tied to a single merchant. This type of dedicated loyalty application is not integrated with a payment instrument such as a credit card.
Accordingly, it would be desirable to provide a payment integrated loyalty system. It would be desirable to provide a payment integrated loyalty system which can integrate a payment instrument with one or more loyalty programs.


This invention relates to wireless signal process, and discloses a method for interference process of an interference signal in an OFDM based wireless communication system, comprising: receiving an interference signal; performing time domain and frequency domain analyses on the interference signal to obtain interference characteristics of the interference signal; determining an interference category of the interference signal according to the interference characteristics of the interference signal; and performing interference process on the interference signal in view of the interference category of the interference signal. The method for interference signal process of this invention is effective to both homogeneous network interference and heterogeneous network interference, so that frequency spectrum sharing of homogeneous networks and existing heterogeneous networks can be realized.

1. Field of the Invention
The present invention relates to wireless signal process, and more specifically, to a method and device for interference process of an interference signal.
2. Description of the Related Art
Currently, wireless networks have gained wide applications, accompanied by interference between different wireless networks. In terms of mechanisms of forming interference, interference is commonly divided into homogeneous wireless network interference and heterogeneous wireless network interference. For example, interference between cells of GSM, CDMA and other cell mobile communication networks is homogeneous wireless network interference. Because the use of official licensed frequency bands, there is no heterogeneous interference coming from other wireless systems. Hence, it can be solved through static frequency spectrum planning with additional network optimization. However, as to interference in heterogeneous wireless networks, it shows significant diversity and complexity, for example, interference between various systems of wireless devices in some ISM frequency bands, or interference between new and obsolete devices in wireless network upgrading. Because it is hard to identify interference sources, formats, and characteristics, its interference process methods become relatively complicated.
Existing interference process solutions for heterogeneous wireless networks are not satisfying in terms of their implementation and effects. For example, multi-antenna techniques, by means of antenna orientations, can combine desired signal while suppressing an interference signal on the receiving side through suitable multi-antenna space weighting. However, such a solution needs multi-antenna equipments provided on receivers and involves complex signal process operations, having great difficulty in implementation and relatively higher cost, and thus, commonly adopted in military wireless communication systems. Besides, energy measurement solutions are widely used in networks, such as WiFi, WSN, etc, which are easier to implement, however, those solutions always adopt avoidance when interference is detected, as a result, they are unable to coexist with other systems, leading to lower frequency spectrum utilization, particularly, when there are larger amount of nodes, which may cause rapid degradation of total throughput.
Especially, in the use of scheduled wideband wireless communication systems having higher spectrum efficiency, such as WiMAX, LET systems, how to share frequency spectrum with existing heterogeneous wireless communication systems is still an unsolved problem. Furthermore, because heterogeneous wireless networks of different systems have entirely different formats and characteristics, it is difficult to find out a uniform and effective manner suitable to all kinds of interference.
Therefore, an interference process method which is effective to both homogeneous networks and heterogeneous networks is highly desirable.

Interference process of interference signal

INTERNATIONAL BUSINESS MACHINES CORPORATION


The present invention discloses a semicrystalline polymer/graphene oxide composite film, comprising: a first semicrystalline-typed polymer, distributed in structural space of the composite film and having a porous structure; and graphene oxide, having a layered structure and distributed in the composite film wherein gas passage exist between adjacent layered structures, the first semicrystalline-typed polymer existing between part of adjacent layered structures forms into a second semicrystalline-typed polymer by further heat treatment after the first semicrystalline-typed polymer and graphene oxide are blended uniformly to be distributed in the composite film so as to fill and seal a portion of the porous structure to block gas from flowing to extend path length(s) of gas passage; wherein graphene oxide existing between the first semicrystalline-typed polymers induces formation of the second semicrystalline-typed polymer.

1. Field of the Invention
The present invention is generally related to a composite film and method thereof, and more particularly to a semicrystalline polymer/graphene oxide composite film and method thereof.
2. Description of the Prior Art
Accompanying with the advance of technologies, new mobile or portable information electronic products keep continuously emerging and a flat panel display thereon has to be applicable to the flexible display technology and flexible electronic devices in addition to being light, thin, compact, etc.
A barrier film is a barrier layer to block gas and moisture from flowing so as to keep gas and moisture on one side of the film. Therefore, such a barrier film can be applied in food wrapping, packaging, solar cells, flexible displays, etc. and plays an important role in electronic and packaging industries. Since organic and metallic substances usually used in electronic industries are sensitive to oxygen and moisture, passage of moisture and oxygen may cause metal in electronic components to oxidize so as to affect performance of a display and shorten lifetime of a display. Therefore, an electronic product should be properly packaged for suitable protection.
A flexible display becomes the current trend for a new era of display research where the substrate for a flexible display is a flexible plastic substrate instead of glass. However, there are many manufacturing problems to be conquered in order to provide a usable reliable flexible plastic substrate. Among these, a flexible plastic substrate having high transparency and high size stability is urgently needed. The size stability and limitation of operational temperature of a flexible plastic substrate is a big limiting factor. On the other hand, gas barrier processing for a flexible plastic substrate is one other key factor to determine the lifetime of a flexible display and to maintain display quality.
Besides, it is reported that polyvinyl alcohol being a water soluble polymer to be high hydrophilic, biocompatible, nontoxic, and capable of film forming (H. M. Kim, J. K. Lee, H. S. Lee, Transparent and high gas barrier films based on poly(vinyl alcohol)/graphene oxide composites, Thin Solid Films, In Press, Corrected Proof.). A polyvinyl alcohol film has the characteristics of high transparency (transmittance >90%) and being a good gas barrier. In addition, it is a dense film with high crystallinity and has good adhesiveness, oil and solvent resistance. Regarding its mechanical properties, a polyvinyl alcohol film has good toughness and large tensile strength (44.1˜63.7) to have good tear resistance among various plastic films so as to be extensively used in food packaging. However, the polyvinyl alcohol film fulfills the requirements as a gas barrier for food packaging but requires further improvement for electronic industries, such as functioning as a substrate of a flexible display.
Furthermore, oxygen transport and free volume in cold-crystallized and melt-crystallized poly(ethylene naphthalate) (PEN) is reported by Y. S. Hu, R. Y. F. Liu, L. Q. Zhang, M. Rogunova, etc. (Macromolecules 2002, 35, 7326-7337) where crystallization enhances gas barrier property of PEN even for small gas molecules. A Study of the Gas Barrier Properties of Highly Oriented Polyethylene is reported by P. S. HOLDEN, G. A. J. ORCHARD, I. M. WARD, etc. (Journal of Polymer Science: Polymer Physics Edition, Vol. 23,709-731 (1985)) where crystallization enhances gas barrier property of polyethylene film even for small gas molecules.
A graphene-made film has high gas barrier property as well but it lacks transparency and flexibility when its film thickness becomes thicker. Therefore, a graphene film cannot be standalone as a gas barrier and may be suitable to combine with other polymers such as polyvinyl alcohol to be used as a composite material to maintain gas barrier property together with transparency.
On the other hand, a gas barrier film with high transparency formed by blendng polyvinyl alcohol water soluble polymer with clay is reported but the gas barrier film becomes brittle to be unsuitable in flexible applications because there are a lot of clay needed to have the gas blockage effect. Besides, a composite film formed by mixing polymer with layered graphene oxide is not reported.
Therefore, it is urgently needed to have a good gas barrier film with high transparency suitable to be coated on a substrate for a flexible display.

Method for fabricating a semicrystalline polymer / graphene oxide composite film


A self lubricating, friction and wear reducing composite material useful over a wide temperature range of from cryogenic temperature up to about 900.degree. C. contains 60-80 wt. % of particulate Cr.sub.2 O.sub.3, dispersed in a metal binder of a metal alloy containing Cr and at least 50 wt. % of Ni, Cr or a mixture of Ni and Cr. It also contains 5-20 wt. % of a fluoride of at least one Group I, Group II, or rare earth metal and, optionally, 5-20 wt. % of a low temperature lubricant metal. Such as Ag, Au, Pt, Pd, Rh and Cu. This composite exhibits less oxidation instability and less abrasiveness than composites containing chromium carbide, is readily applied using plasma spray and can be ground and polished with a silicon carbide abrasive.

1. Field of the Invention
The invention relates to a self-lubricating solid composite comprising chromium oxide dispersed in a metal binder. More particularly the invention relates to a friction reducing and wear resistant solid lubricant composite comprising Cr.sub.2 O.sub.3 in a metal binder, along with metal fluoride and, optionally, a metal effective as a lubricant at low temperature, for use over a wide temperature spectrum from cryogenic (-185.degree. C.) temperature to about 900.degree. C.
2. Background of the Disclosure
There is an increasing need for durable solid lubricant materials which will operate over wide range of temperatures and at high speeds, for long periods of time. Such materials find increasing need in space satellites and vehicles, adiabatic diesel and advanced turbo machinery, process control valve stems, dry running stirling engine cylinders, high speed foil air bearings, rotating face valves, butterfly valve stems, and the like. Numerous advances in the art have been made over the last thirty years since early self-lubricating compositions, such as composites of silver, platinum, molybdenum disulfide, lead oxide and silicon dioxide were disclosed in U.S. Pat. No. 3,199,934. A significant advance was made by Sliney as a porous nickel-chromium alloy in which is dispersed, via infiltration, a metal fluoride eutectic and, optionally, a coating of the eutectic and silver on the outer bearing surface as disclosed in U.S. Pat. No. 3,419,363. However, the porous metal provided a greatly increased surface area and high temperature oxidation of these porous sintered metals posed significant problems at temperatures above about 700.degree. C. This lead to the development of another self-lubricating composite in which the metal component is a porous high temperature alloy body which is either infiltrated with both metal fluorides and glass or via plasma spray codeposition of the component powders, as disclosed in U.S. Pat. No. 4,214,905. The presence of the glass in the composite increased the oxidation resistance of the metal binder. The silver is electrodeposited on the metal. A still further improvement in the art was the development of a more wear resistant composite of nickel-cobalt bonded chromium carbide with metal fluoride and silver which is known as PS/PM200 and is disclosed in U.S. Pat. No. 4,728,448 and which has been extensively published in the literature. While this material has met with much success as a durable, long lasting, wear resistant self-lubricating composite useful over a wide temperature range, it is expensive and the chromium carbide component is so hard as to require costly diamond grinding achieve the desired dimensions prior to service. Further, at very high temperatures of 800.degree. C. or more in an oxidative environment such as air, the chromium carbide tends to oxidize. This degrades the friction and wear properties and causes slight dimensional swelling of the composite body. It would be a significant improvement to the art if a material were available with the strength, low friction and wear characteristics of the PS/PM200, without the drawbacks of very high temperature oxidative instability, high component cost and the need for expensive diamond grinding to polish the bearing surfaces and achieve the proper dimensions of the composite body.

Self-lubricating composite containing chromium oxide

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration


The invention provides texture mapping techniques that facilitate interactive painting of a three-dimensional virtual surface by a user in object space, without requiring global parameterization. The texture mapping techniques feature rendering texture for a given virtual object using a plurality of composite textures, each formed by blending collapsible texture layers. Texture coordinates in texture space are derived using information determined at the time of surface mesh generation. The invention features dynamic texture allocation and deallocation, allowing a user to interactively modify the shape of a painted, three-dimensional model. Finally, the invention features an architecture for combined graphical rendering and haptic rendering of a virtual object, allowing a user to experience force feedback during the painting of the object in object space.

Certain computer graphics applications graphically render the surface of a three-dimensional virtual object. The surface of a three-dimensional virtual object is generally represented as a mesh of polygonal surface elements, for example, triangles. Attributes, such as color intensity, are assigned to surface elements of the virtual object, which are then displayed to the user.
The resolution of the surface mesh is typically chosen according to the three-dimensional complexity of the object. For example, rendering a virtual object having a complex geometry may require a tight mesh of many small surface elements, whereas rendering a virtual object of simpler shape may be performed with a looser mesh of fewer, larger surface elements.
It is typically not possible to achieve sufficient realism by assigning color values to vertices of each surface element, particularly if the surface elements are large. This problem may be overcome by representing three-dimensional surface properties of the object using a texture in two-dimensional space. Texture mapping permits improved resolution of surface properties, such as color values, within each surface element, and allows certain operations to be performed on the three-dimensional object as if it were flat.
Mapping methods are used to relate points on the surface of a three-dimensional virtual object to corresponding points of a two-dimensional surface. For example, mapping methods can be used to relate points on the surface of a three-dimensional sphere, such as the Earth, to corresponding points of a two-dimensional map. Certain graphics applications perform texture mapping for a three-dimensional virtual object by establishing a global parameterization that links every surface element in the three-dimensional object space to an element in two-dimensional texture space. The mapping process may not be automatic and may require manual input from the user. A goal of these mapping schemes is to produce a coherent two-dimensional texture whose elements are arranged in such a way that the distortion of the object surface is acceptably low. For many complex virtual objects, this poses a problem that is either computationally difficult or intractable.
Furthermore, current graphics applications require a user to paint the surface of a virtual object in two-dimensional texture space before applying the texture on the virtual object in three-dimensional object space. This results in a less interactive, less intuitive experience for the user.
Moreover, current methods do not allow a user to modify the shape of the object after its surface has been painted without losing surface data from unmodified portions of the object. This is due, in part, to the need to re-mesh and re-parameterize the entire model following any modification of the underlying three-dimensional model.
A method of texture painting has recently been introduced to allow texture mapping without global parameterization. M. Foskey et al., "ArtNova: Touch-Enabled 3D Model Design," IEEE Virtual Reality 2002, pp. 119–126, (March 2002).
However, there remains a need for mapping methods that allow a user to modify the shape of an object after its surface has been painted, without losing the surface data from unmodified portions of the object. There also exists a need for a more efficient graphical rendering method that is able to support the rendering of complex virtual objects, while still allowing a user to interactively paint directly onto the object in object space. Furthermore, there is a need for a method of blending textures while maintaining the interactivity of painting, without creating graphical artifacts.

Apparatus and methods for texture mapping


A method of fabrication of an electrooptical device comprises depositing a colloid system of anisometric particles onto at least one electrode and/or onto at least one substrate and/or onto at least one layer of an isotropic or anisotropic material to form at least one layer of an electrooptical material, externally aligning the colloid system to form a preferred alignment of the colloid system particles, drying the colloid system, and forming at least one electrode and/or at least one layer of an isotropic or anisotropic material on at least a portion of the layer of the electrooptical material.

Electrooptical devices based on electrooptical materials such as lithium niobate (LiNbO3), KDP and KTP have been hereto described. See I. P. Kaminov et al., "Optical Fiber Telecommunications", Vol. IIIB, Ed. by Academic Press (1997).
There are known electrooptical devices such as light modulators based on a D-shaped optical fiber and using a lithium niobate crystal. See W. Johnstone et al., "Fiber Optic Modulators Using Active Multimode Waveguide Overlays", Electron. Lett., Vol. 27, No. 11, 894–896 (1991). D-shaped optical fiber, also called side-polished optical fiber, refers to an optical fiber having a D-shaped cross section. Light modulators of this type are usually produced on a plane-parallel plate of a quartz glass which is provided with a groove having a curvature typically from several dozens of centimeters to several meters. A single-mode or monomode optical fiber is glued into this groove. Then the plate side having the groove with the fiber glued therein is ground until this plane reaches the fiber core so that the fundamental mode (localized predominantly in the core) can penetrate through the reflective cladding to the polished surface. After this processing, the optical fiber section becomes D-shaped. See S. M. Tseng et al., "Side-Polished Fibers", Appl. Optics, Vol. 31, No. 18, 3438–3447 (1992). The polished surface of the D-shaped optical fiber is coated with a thin transparent electrode layer of indium tin oxide (ITO) composition. Then a thin lithium niobate crystal is glued onto this electrode and ground to reduce the thickness to 20–30 microns. Finally, the second electrode is applied above the lithium niobate crystal layer.
The light modulator operates as follows. An external voltage applied to the electrooptical lithium niobate crystal changes the refractive index of the material and modifies the condition of resonance between the fundamental mode of the optical fiber and the guided modes of the lithium niobate layer. The resonance condition is essentially the condition of phase synchronism, or equal propagation constants of the guided modes of the planar optical waveguide with a lithium niobate core and the fundamental mode of the D-shaped optical fiber. When the modes are in resonance, the light signal is effectively pumped from the optical fiber into the lithium niobate crystal and the output signal intensity at the fiber end is decreased. If the applied voltage is changed so as to alter the refractive index of the lithium niobate crystal and break the resonance, the light passes through the D-shaped optical fiber without loss in intensity. In the prior art, a significant level of the output signal modulation is achieved by applying a voltage of 150 V to a 35 micron-thick control layer between ITO electrodes.
One disadvantage of the light modulator described above is that the manufacturing process for thin lithium niobate layers is very complicated. Further, the interelectrode distance determined by the thickness of the lithium niobate crystal is relatively large.
Optical switches using the same principle of operation have been described employing a layer of material with variable refractive index on the surface of a D-shaped optical fiber and a liquid crystal layer. See S. M. Tseng et al., "Low-Voltage Optical Fiber Switch", Jpn. J. Appl. Optics, Part 2, Vol. 37, L42–L45 (1998). In the optical switches of this type, a voltage about 30 V is needed to break the resonance for an interelectrode distance of 13 microns. One disadvantage of this device is the relatively low operation speed determined by the slow response of the liquid crystal. The switching time is about 7 milliseconds and the liquid crystal cannot be reoriented by an ac voltage with a frequency of 100 Hz.
There are known electrooptical devices such as light modulators having charge carrier injectors. See E. R. Mustel et al., "Light Modulation and Scanning Methods", Nauka, Moscow (1970). The light modulator of this type employs a layer of an electrooptical material representing an n-type semiconductor film on a substrate. The light propagates along this film which serves as the optical waveguide. Deposited above this n-type film is a layer of a p-type semiconductor, which forms a p-n junction. The device also contains a pair of electrodes, one in ohmic contact with the n-type semiconductor film and the other with the p-type semiconductor film, to which a control (dc or ac) voltage is applied. When a control voltage is applied to the p-n junction in the forward direction, the charge carriers (holes) are injected into the optical waveguide (n-type semiconductor film). The injection of holes into the optical waveguide increases the optical absorption of the material, thus modulating the light.
One disadvantage of this type of light modulators is the current-induced heating of the p-n junction, which requires taking special measures to thermally stabilize the entire device. Another disadvantage is the limitation imposed on the modulation frequency by the mechanism of light modulation employed in this device. Indeed, the lifetime of the minority carriers injected through the p-n junction is limited, usually to about 10−6 seconds for the holes. For this reason, the light modulators guided by the minority carrier injection can operate only at frequencies up to 105–106 Hz. The electric current passed through the optical waveguide must be of sufficiently large density. This requirement poses limitations on the system dimensions. The greater the size of the device, the higher the current required to maintain the density on a level necessary for the device operation. A further disadvantage related to the electric current passage is the large energy consumption, which increases with the current value.
There are known electrooptical devices which contain a layer of a material whose optical properties change depending on the applied electric field strength. See WO 00/45202. One example of such material is ferroelectric ceramics. Ceramic materials possessing ferroelectric properties usually exhibit the phenomenon of birefringence. Thus, the ceramic layer is an electrooptical material and the applied electric field can control the device. Owing to a combination of the ferroelectric and electrooptical properties of the material, this system can be employed for controlling and modulating light signals in fiber optic communication systems, nonlinear optical devices, and electrooptical devices such as modulators, shutters, and frequency multipliers, etc.
The observed optical effects are related to orientation or reorientation of the domain polarization vector in an applied electric field. As a result, the optical axes of the ceramic grains are oriented or reoriented as well. The reorientation of domains in the electrooptical ceramic material under the action of an applied electric field is accompanied by the development of mechanical stresses perpendicular to the field direction.
One disadvantage of the ferroelectric ceramics is that they retain orientation of the domain polarization vector for an arbitrarily long time after switching off the film. Therefore, additional measures have to be taken in order to restore the initial state, such as applying control pulses with opposite polarity and half amplitude, mechanically deforming the ceramic substrate, and applying a high-frequency electric field of small amplitude. This property of the ferroelectric ceramics complicates the control system of the electrooptical devices.
Another disadvantage of the ferroelectric ceramics is the difficulty of ensuring a fast operation speed. Indeed, an increase in the light modulation rate at a given modulation efficiency requires increasing the control voltage amplitude. This fact and the delayed electrooptical response in such materials are related to the energy consumption for the formation and reorientation of the domain walls. For example, at electric pulse duration of about 2 μs, the pulse amplitude must be two times greater than the quasistatic control voltage; to reduce the pulse duration to 1 μs, the pulse amplitude must be three times greater, and so on.
Additional disadvantage is the fatigue inherent in the ferroelectric ceramic materials. Straining a ceramic material in the range corresponding to the spatial modulation of light (e.g., at the expense of partial repolarization) encounters difficulties related to the deformation character of the field-induced polarization. For this reason, repeated on-off cycles of an electric field, especially of large strength (above 5 kV/cm), lead to the accumulation of a residual deformation. This residual deformation decreases the optical contrast of modulated light, which is manifested by irreversible polarization of the electrooptical ferroelectric ceramic layer.
Another disadvantage of the above device is extremely strong temperature dependence of the characteristics of a ferroelectric layer. Temperature variations lead to changes in the optical properties of the control device. In order to exclude the temperature drift, it is necessary to provide the control device with a thermal stabilization system, which increases the energy consumption, complicates the device, and increases the cost of production.
A significant disadvantage of the device employing ferroelectric ceramics is the probability of phase distortions introduced into the data processed as a result of strong deformation of the ceramic plate and the inverse piezoelectric effect. The presence of defects and internal stresses leads to degradation of the properties of such materials which are extremely sensitive to manufacturing process parameters, making production of the devices a difficult task.
There are known electrooptical devices based on organic materials. See U.S. Pat. No. 5,172,385 to Forrest et al. and L. M. Blinov, "Electro- and Magneto-optics of Liquid Crystals", Nauka, Moscow (1978), pp. 115, 351, 352. The devices of this type contains two electrodes which are either both transparent if the system operates in the beam transmission mode, or transparent and reflecting, if the system operates in the beam reflection mode. An electrooptical material layer placed between the electrodes represents a liquid crystal, the thickness of which (interelectrode distance) is determined by sealing spacers. The electrodes are deposited onto glass substrates.
A large number of the chemical classes of organic molecules provides for a broad spectrum of materials which can be effectively used in fiber optics, integrated optics, and optical communications.
There are classes and groups of organic substances of various chemical natures, composed of the molecules or molecular chains such as phthalocyanines, polyacetylenes, aromatic hydrocarbons, conjugated polymeric systems, etc. that possess dielectric, semiconducting, and even metallic properties. A common feature of these molecules is the presence of superstructures. There are known organic films based on polymeric materials (U.S. Pat. Nos. 4,204,216; 4,663,001; 4,269,738; 5,104,580; 3,775,177; F.R. Patent No. 2,583,222), salts of linear polyaniline compounds (U.S. Pat. No. 4,025,704), phthalocyanine derivatives (U.S. Pat. Nos. 5,525,811; 6,051,702), organic dyes (U.S. Pat. No. 3,844,843), and porphyrins (U.S. Pat. Nos. 3,992,205; 3,935,031), which are widely used in modern electronic devices as the layers generating charge carriers in the course of photoelectron processes in photovoltaic devices (U.S. Pat. No. 4,164,431), solar cells (U.S. Pat. No. 3,844,843), and polarization devices (U.S. Pat. No. 5,172,385).
There are various known methods for the formation of organic films and creation of anisotropic film structures, for example Langmuir-Blodgett technique (U.S. Pat. No. 5,079,595), molecular beam epitaxy, etc. However, optical devices employing liquid-crystalline molecular compounds possess a number of disadvantages, in particular, require specially prepared substrates, alignment layers, or high-vacuum conditions for the obtaining of highly ordered and clean structures. Special and advanced technologies are employed and even these often cannot ensure the obtaining of films possessing a certain type of order and ensuring required optical anisotropy.
There are known electrooptical devices using an electrooptical material of a liquid crystal (host) matrix with dispersed organic dye (guest) molecules. See I. K. Vereshchagin et al., "Introduction to Optoelectronics", p. 173, Vysshaya Shkola, Moscow (1991), L. M. Blinov et al., "Electrooptical Effects in Liquid Crystal Materials", p. 182, Springer-Verlag, New York (1994). The control device operates on the guest-host interaction principle and is structurally analogous to that described above, comprising two electrodes which are either both transparent if the system operates in the beam transmission mode, or transparent and reflecting, if the system operates in the beam reflection mode. An electrooptical material layer placed between the electrodes represents a liquid crystal doped with dye molecules. The thickness of this layer (interelectrode distance) is determined by sealing spacers placed between the electrodes deposited onto glass substrates. The molecules of liquid crystal and dye are oriented in the same direction parallel to the alignment layers. In the absence of an applied voltage, a light polarized in the long axis of dye molecules is absorbed and no signal is transmitted through the optical device. This absorption in the dye is related to the fact that the electric field of the light polarized parallel to the long axis of the dye molecules drives electrons to oscillate between the ends of the molecule, thus consuming the beam energy. An external voltage applied to the electrodes creates an electric field in the liquid crystal. This field rotates the liquid crystal molecules and, hence, the dye molecules (due to the guest—host effect) so that the long axis of the dye molecules becomes perpendicular to the plane of polarization of the light beam. In this cease, electrons in the dye molecules are not forced to move by the electric field of the light beam. Therefore, the light is not absorbed in the liquid crystal layer and the beam is transmitted through the optical device without significant losses.
One disadvantage of the above optical device is the relatively low operation speed of, which is characterized by a switching time on the order of 0.1 second. This device operates poorly at reduced temperatures, under which conditions the operation speed further sharply reduces. The device has insufficient working life, which amounts to about 104 hours.

Electrooptical devices, electrooptical thin crystal films and methods making same


A projectile, particularly a practice round, has a projectile body that includes a hollow ogive that bursts upon striking the target into which marking material is inserted. The marking material is released when the projectile strikes the target and the ogive bursts. The marking material is covered by a protective cap that breaks when the projectile bursts on the target.

The invention relates to a projectile, particularly to a practice round, with a projectile body including a hollow ogive (cup-shaped head) that bursts upon striking the target. This ogive contains dye, particularly a colored powder, whereby the marking material is released to mark the strike point when the projectile strikes the target and when the ogive bursts.
In a practice round, e.g., a practice projectile or a practice bomb that itself does not include live explosive, it is important to mark the strike point on the target so that optimal practice results may be obtained.
For this, the projectile includes at its tip an ogive into which the marking material, e.g., a reddish dye powder, is inserted. The ogive is made of a material such as plastic that bursts when it strikes the target, releasing the dye powder. The dye is scattered for a certain radius around the strike point, and is also scattered by the wind, thus showing the strike point clearly.
Projectiles of the type discussed here are, for example, mid-caliber projectiles (40 mm) that are belt-fed and that are fired from a rapid-fire cannon in series.
When handling such projectiles, the ogive of a projectile in the belt occasionally breaks open when it strikes an object, at least partially releasing the marking material and contaminating other projectiles. When this occurs the affected projectiles in the belt must be replaced. It is even worse if, for example, the projectile is improperly aligned in the rapid-fire cannon. In such case, the ogive of the projectile may be broken within the chamber, leading to contamination of the weapon, which must subsequently be cleaned, resulting in lost time. Also, such a misalignment of a live round fired from that weapon may lead to a loading jam.


A flow measuring apparatus of an embodiment is provided that comprises a cylinder and a piston movable in the cylinder between first and second positions. The piston divides the cylinder's interior area into first and second portions. A biasing member urges the piston toward the first position. A first fluid passageway allows fluid to bypass the piston, and a second fluid passageway is in fluid communication with the first fluid passageway and with the first portion of the cylinder. The second fluid passageway provides fluid to the first portion of the cylinder to move the piston toward the second position. A flow diverter is movable between a first flow position that allows fluid to pass through the first fluid passageway to the outlet and a second flow position that causes fluid to flow into the second flow passageway and into the first portion of the chamber. A retention mechanism is moveable to move the flow diverter to the closed position and is moveable to allow the flow diverter to move to the open position when the piston reaches the second position.

Meter provers are positive displacement devices that launch pistons in barrels, timing their travel time to deduce the flow rate. Piston travel is typically monitored in only one direction to calibrate or check accuracy of a flow meter. Provers tend to have elaborate hardware to minimize the flow rate measurement errors and are typically intended to calibrate meters used in flow lines greater than four inches in diameter. For smaller lines, the piston meter prover concept has been used to make positive displacement flow meters by providing mechanisms that allow the piston to reciprocate continuously. Reciprocation is facilitated by mechanical linkages that divert valve mechanisms or by electrically operated three or four way diverting valves to achieve piston reciprocation. Often in high pressure hydraulic systems it is desirable to measure flow rates below five gallons per day. For various reasons, a continuous flow measurement may not be required, but a reliable, accurate means tolerant to debris is desirable.

Flow measuring apparatus including a piston movable in the flow barrel


A III-Nitride field-effect transistor, specifically a HEMT, comprises a channel layer, a barrier layer on the channel layer, an etch stop layer on the cap layer, a dielectric layer on the etch stop layer, a gate recess that extends to the barrier layer, and a gate contact in the gate recess. The etch stop layer may reduce damage associated with forming the recessed gate by not exposing the barrier layer to dry etching. The etch stop layer in the recess is removed and the remaining etch stop layer serves as a passivation layer.

Materials such as silicon (Si) and gallium arsenide (GaAs) have found wide application in semiconductor devices for lower power and (in the case of Si) lower frequency applications. These, more familiar, semiconductor materials may not be well suited for higher power and/or high frequency applications, however, because of their relatively small bandgaps (e.g., 1.12 eV for Si and 1.42 for GaAs at room temperature) and/or relatively small breakdown voltages.
In light of the difficulties presented by Si and GaAs, interest in high power, high temperature and/or high frequency applications and devices has turned to wide bandgap semiconductor materials such as silicon carbide (2.996 eV for alpha SiC at room temperature) and the Group III nitrides (e.g., 3.36 eV for GaN at room temperature). These materials, typically, have higher electric field breakdown strengths and higher electron saturation velocities as compared to gallium arsenide and silicon.
An example of a device developed for high frequency applications is the metal-semiconductor field effect transistor (MESFET). A MESFET is formed on a high-resistivity or semi-insulating substrate by placing an epitaxial layer of conductive p or n-doped material on the substrate. Source, gate, and drain contacts are then made to the epitaxial layer, and when a potential (voltage) is applied to the gate, it creates a depletion region that pinches off the channel between the source and drain thereby turning the device off.
Another device of particular interest for high power and/or high frequency applications is the High Electron Mobility Transistor (HEMT), which, in certain cases, is also known as a modulation doped field effect transistor (MODFET). These devices may offer operational advantages under a number of circumstances because a two-dimensional electron gas (2DEG) is formed at the heterojunction of two semiconductor materials with different bandgap energies, and where the smaller bandgap material has a higher electron affinity. The 2DEG is an accumulation layer in the undoped ("unintentionally doped"), smaller bandgap material and can contain a very high sheet electron concentration in excess of, for example, 1013 carriers/cm2. Additionally, electrons that originate in the wider-bandgap semiconductor transfer to the 2DEG, allowing a high electron mobility due to reduced ionized impurity scattering.
This combination of high carrier concentration and high carrier mobility can give the HEMT a very large transconductance and may provide a strong performance advantage over MESFETs for high-frequency applications.
High electron mobility transistors fabricated in the gallium nitride/aluminum gallium nitride (GaN/AlGaN) material system can generate large amounts of RF power because of the combination of material characteristics that includes the aforementioned high breakdown fields, their wide bandgaps, large conduction band offset, and/or high saturated electron drift velocity. A major portion of the electrons in the 2DEG is attributed to polarization in the AlGaN.
HEMTs in the GaN/AlGaN system have already been demonstrated. U.S. Pat. Nos. 5,192,987 and 5,296,395 describe AlGaN/GaN HEMT structures and methods of manufacture. U.S. Pat. No. 6,316,793, to Sheppard et al., which is commonly assigned and is incorporated herein by reference, describes a HEMT device having a semi-insulating silicon carbide substrate, an aluminum nitride buffer layer on the substrate, an insulating gallium nitride layer on the buffer layer, an aluminum gallium nitride barrier layer on the gallium nitride layer, and a passivation layer on the aluminum gallium nitride active structure.
One step in the fabrication of some nitride-based transistors is the formation of a gate contact in a recess. A thick cap structure of the transistor may be desirable in achieving high current capability and low dispersion. However, a gate recess through the cap layer may be desirable to achieve high breakdown voltage, low RF dispersion and/or high transconductance with concomitant high-frequency performance. On the other hand, an etching process used to form a recessed gate structure may damage the underlying barrier layer(s). Damage to the barrier layer may result in the formation of a high density of surface states or traps that adversely affect device operation. United States Patent Publication No. 2005/0170574 A1, published Aug. 4, 2005, and entitled "NITRIDE-BASED TRANSISTORS WITH A PROTECTIVE LAYER AND A LOW-DAMAGE RECESS AND METHODS OF FABRICATION THEREOF", the disclosure of which is incorporated herein as if set forth fully herein, describes techniques to provide a low-damage recess through SiN passivation and resulting devices. U.S. patent application Ser. No. 10/897,726, filed Jul. 23, 2004 and entitled "METHODS OF FABRICATING NITRIDE-BASED TRANSISTORS WITH A CAP LAYER AND A RECESSED GATE", the disclosure of which is incorporated herein as if set forth fully herein, describes techniques to provide a low-damage recess through the annealing of the recessed gate prior to formation of the gate contact and resulting devices.

Methods of fabricating nitride-based transistors with an ETCH stop layer


An LED lamp adapted for use as a bicycle light includes a lamp/switch module and a power supply/control module. The control includes a microcontroller that performs both light operating functions and battery charging control functions. A low battery warning is provided as a non-repeating, short sequence of flashes of the lamp.

Typical battery-powered bicycle headlamps have utilized incandescent lamps, although, with the introduction of high-intensity light emitting diodes (LEDs) efforts have been made to utilize LEDs in bicycle headlamps. A problem with bicycle headlamps, including LED headlamps, is that the beam intensity gradually diminishes as the battery drains. The beam intensity can gradually diminish to a very low level before the user is consciously aware that a dangerous condition has arisen.
In the case of an LED headlamp, it is desirable to provide for selectable power levels in order to conserve power and prolong battery life. Selection of power levels is preferably accomplished electronically by operating an LED, or a bank of LEDs, by current pulses, and varying the duty cycle of the pulses. Control of the LED or LED bank, therefore requires an electronic control circuit.
Lithium ion (Li-ion) power supplies are a reliable energy source for bicycle lights because they are reliable, they are rechargeable, they have a high power to weight ratio, and they have a long life, if operated properly. Control of the charging and operation of a Li-ion power supply is also preferably accomplished by means of an electronic control circuit that prevents excessive discharge, prevents overcharging, and, in the case of a Li-ion battery, maintains the cell voltages in balance.


A terminal structure includes a portion of a flexible printed circuit board and a plurality of metal terminals each consisting of a slender, elongate metal plate. The circuit board has a plurality of electrically conductive patterns provided on a resin film, a prescribed portion of the board having a connector insertion portion of a width substantially the same as that of an insertion hole of a connector. The plurality of metal terminals are placed in parallel on the flexible printed circuit board in such a manner that distal ends thereof are situated adjacent a distal end of the connector insertion portion, and each metal terminal is fixedly bonded to a respective one of the electrically conductive patterns provided on the flexible printed circuit board. The width of the connector insertion portion of the flexible printed circuit board to which the metal terminals have been attached is such that the connector insertion portion will not extend beyond the outer sides of the two outermost metal terminals on the longitudinal side edges of the connector insertion portion.

1. Field of the Invention
This invention relates to the terminal structure of a flexible printed circuit board, wherein the terminal is ideal for connection to a miniaturized connector.
2. Description of the Prior Art
Electronic parts of a wide variety have recently been reduced in size and thickness, and this has been accompanied by the widespread use of flexible printed circuit boards designed to make effective utilization of available space. A flexible printed circuit board of this kind is obtained by forming electrically conductive patterns on a flexible insulating film.
In order to connect a flexible printed circuit board to the connector of an electronic part, a portion of one edge of a flexible printed circuit board 81 that is provided with electrically conductive patterns 82 is directly inserted into a connector, as illustrated in FIG. 9.
Since the flexible printed circuit board 81 consists of a thin film and exhibits flexibility, it has little strength. Therefore, in a case where the flexible printed circuit board 81 is directly inserted into a connector 90 (FIG. 10), a rigid resin base 86 for reinforcement is bonded to the underside of the flexible printed circuit board 81, as shown in FIG. 9.
The recent progress that has been made in miniaturizing devices has been accompanied by miniaturization of the connectors used to connect the flexible printed circuit board 81. In order to accommodate such miniaturized connectors, it is necessary to reduce the spacing between the electrically conductive patterns 82 shown in FIG. 9. With such an expedient, however, certain problems arise, which will now be described.
(1) In order to manufacture the flexible printed circuit board 81, the electrically conductive patterns 82 are formed on a large resin film by etching or screen printing, after which the resin film is subjected to cutting. As a result, a spacing .sup.l 1 of the electrically conductive patterns 82 can be rendered constant with good accuracy, as shown in FIG. 9, however, owing to a mechanical error which develops when the resin film is cut, a deviation is produced in spaces .sup.l 3, .sup.l 3 between both side edges of the flexible printed circuit board 81 and the outermost electrically conductive patterns 82 (that is, .sup.l 3.noteq..sup.l 3 is the result of the aforementioned mechanical error). When this deviation occurs in the spaces .sup.l 3, .sup.l 3 the electrically conductive patterns 82 cannot be accurately connected to the respective connection terminals inside the connector even if the flexible printed circuit board 81 is accurately inserted into the insertion hole of the connector. The more the spacing of the electrically conductive patterns 82 is narrowed, the more prominent this problem becomes. In certain cases, an electrically conductive pattern 82 which Is not intended to be connected may come into contact with a connection terminal inside the connector, thereby producing a short circuit.
(2) In order to smoothen the insertion of the flexible printed circuit board 81, a prescribed amount of play in the width direction is provided between the flexible printed circuit board 81 and the inner wall of the insertion hole of the connector. Consequently, when the flexible printed circuit board 81 is inserted into an insertion hole 91 of a connector 90, as illustrated in FIG. 10(a), there are cases where the flexible printed circuit board 81 fits into the insertion hole 91 askew at small angle .theta.. If the spacing .sup.l 1 (see FIG. 9) between the electrically conductive patterns 82 is small in such case, there is the danger that an electrically conductive pattern 82 which Is not intended to be connected may come into contact with a connection terminal inside the connector 90, thereby producing a short circuit.
(3) When the flexible printed circuit board is inserted into the insertion hole 91 of the connector 90, there are cases where the insertion of the flexible printed circuit board 81 into the insertion hole 91 stops midway, as shown in FIG. 10(b). In other words, since there is no indication on the flexible printed circuit board 81 by which the amount of insertion can be determined, it may be misconceived that the two are perfectly connected when in fact they are not, in which case the two would remain in an imperfectly connected state.

Terminal structure of flexible printed circuit board


An access control system includes an access control device, a wireless communication device, and a central controller. The central controller issues authorization codes to the wireless communication device. The wireless communication device is used by an authorized party to enable or activate a protected function secured by an access control device. To enable or activate the protected function, the authorized party uses the wireless communication device to transmit an access request to the access control device, which responds by transmitting an authentication challenge to the wireless communication device. The wireless communication device must transmit a valid authentication response based on the authentication challenge and a valid authorization code stored in its memory. If a valid authentication response is received, the access control device enables or activates the protected function.

The present invention relates generally to security systems to provide security for a protected function and, more particularly, to a security system that uses a challenge/response protocol to provide security for the protected functions.
Traditional locks employ a key or combination to limit access to property. Presumably, only persons with right to access the property will possess the key or combination needed to operate the lock. This traditional approach is still widely used. More recently, traditional key and combination locks have been replaced by electronic locking systems actuated by plastic cards with magnetic strips. This type of electronic lock is commonly used in hotels. In this type of system, a door handle and electromechanical locking mechanism are integrated with a magnetic card reader within a strong metal enclosure. The magnetic card reader reads the inserted card, checks for a key code, and actuates the locking mechanism to unlock the door if the correct key code is supplied.
It is also known in the past to use some sort of identification, such as a PIN code, fingerprint, or iris scan, to enable a locking mechanism to unlock a door. One such device is disclosed in U.S. Pat. No. 6,038,666 to Hsu et al. This patent discloses a wireless method of operating a door lock using fingerprint data. The door lock must first be loaded with fingerprint data of an authorized user and the user's public cipher key. A mobile device carried by the authorized user is also loaded with the same fingerprint data and communicates wirelessly with the door lock. The name of the user is transmitted unencrypted to the door lock. The door lock generates a random public/private cipher key pair and sends the public key to the user's device. The user's device doubly encrypts the fingerprint data using the user device's private key and the door lock's public key in unspecified order, and transmits the result to the door. The door decrypts the received fingerprint data and compares it with the stored fingerprint data, unlocking the door if the fingerprint data matches.


The present invention relates to a method of making a ready-to-press agglomerated powder mixture by wet milling a powder mixture containing binder and spray drying said slurry to an agglomerated powder useful for making cutting tools for metal machining, tools for rock drilling and wear parts. If the binder is a baroplastic polymer having a pressure induced transformation from hard to soft well developed agglomerates with good flow properties and good plasticity are obtained. The hard property of the binder is used at normal pressures, during handling of the spray-dried powder and in the green body, whereas the softer properties are used at higher pressures during the pressing of the material when the pressure exceeds from about 10 to about 50 MPa.

The present invention relates to a method of making agglomerated cemented carbide, cermet or ceramic powder mixtures useful for making cutting tools for metal machining, tools for rock drilling and wear parts.
Cemented carbide or cermet alloys are made of hard constituents from about 5 to about 20 vol-% metal binder phase essentially based on Co and/or Ni. In cemented carbides, the hard constituent is generally carbides whereas in cermets they are nitrides and/or carbonitrides and possibly carbides.
Cemented carbide or cermet bodies are made by powder metallurgical methods of wet milling a powder mixture containing powders forming the hard constituents and binder phase as well as binders and other additives often of a proprietary nature, drying the milled mixture to a ready-to-press powder with good flow properties, pressing the powder in press tools or extruding to bodies of desired shape and finally sintering.
The milling operation produces a slurry which is suitable for subsequent drying. The drying can be performed by spray drying or freeze granulation followed by freeze drying. As a result of the drying process spherical agglomerates of about 0.1 mm diameter are obtained held together by the binder, generally Poly Ethylene Glycol, PEG. This PEG binder is present during pressing but is ultimately removed during sintering.
It is important that the agglomerates have good flow properties to allow an even filling of the press tool and to allow redistribution thereof in the initial phase of the compaction. This is generally obtained by choosing hard agglomerates. Such agglomerates are obtained by using PEG with a high molecular weight. This often leads to porosity problems in the final sintered body. At a certain point in the compaction operation, soft agglomerates are desired in order to secure an even and homogeneous density in the pressed body. This can be obtained by using a PEG with low molecular weight. This gives a pressed body with low porosity but with a less than even density distribution due to the inferior flow properties. When high molecular weight and low molecular weight PEG polymers are blended, a compromise can be achieved, but it is not optimal neither regarding the flow properties nor the density variations in the green body. Optimal would be a binder that has hard properties during the handling of the granules, the filling of the mold and in the green body, but soft properties during the pressing of the material.
Baroplastic is a novel class of materials which is a block copolymer composition capable of being processed by the application of pressure. It is a core-shell polymer of particles with a core of a polymer with soft properties, and a shell of a polymer with hard properties with the size of the particles in the range of from about 50 to about 200 nm. During normal pressure, the core and the shell polymers are not miscible, and hence they stay separate, as core and shell. However, the miscibility of the polymers increases with increasing pressure, and at high pressures the polymers are mixed and get properties in-between the soft core and the hard shell. The increased miscibility at high pressures is reversible, and on lowering the pressure the polymers form a core-shell structure again.
In "Low-temperature processing of "baroplastics" by pressure-induced flow" by J. A. Gonzalez-Leon, M. H. Acar, S.-W. Ryu, A.-V. G. Ruzette and A. Mayes, Nature vol. 426, 424-428, 2003, a process for manufacturing baroplastic polymers are disclosed. The baroplastic polymers obtained low-temperature formability at ambient temperature and could be remolded without degradation.
In "Core-shell polymer nanoparticles for baroplastic processing" by J. A. Gonzalez-Leon, S.-W. Ryu,S. A. Hewlett, S. H. Ibrahim and A. Mayes, Macromolecules, vol 38, 8036-8044, 2005, the properties of baroplastic polymers are further investigated. Especially, the impact of composition, particle size and structure on the mechanical behavior were investigated.
U.S. Pat. No. 6,632,883, herein incorporated by reference in its entirety, discloses block copolymer compositions capable of being processed by the application of pressure. A method for predicting phase diagrams of polymer blends and block copolymers are also disclosed.

Method of making cemented carbide or cermet agglomerated powder mixtures


A spin orbit torque memory device having a vertical transistor structure. The spin orbit torque memory device includes a magnetic memory element such as a magnetic tunnel junction formed on a spin orbit torque layer. The vertical transistor structure selectively provides an electrical current to the spin orbit torque layer to switch a memory state of the magnetic memory element. The vertical transistor structure accommodates the relatively high electrical current needed to provide spin orbit torque switching while also consuming a small amount of wafer real estate. The vertical transistor structure can include a semiconductor pillar structure surrounded by a gate dielectric layer and a gate structure such that the gate dielectric layer separates the gate structure from the semiconductor pillar.

Random access memory (RAM) is a ubiquitous component of modern digital circuit architectures. RAM can be a standalone device, or can be integrated in a device that uses the RAM, such as a microprocessor, microcontroller, application specific integrated circuit (ASIC), system-on-chip (SoC), and other like devices. RAM can be volatile or non-volatile. Volatile RAM loses its stored information whenever power is removed. Non-volatile RAM can maintain its memory contents even when power is removed.
Magnetoresistive Random Access Memory (MRAM) is a non-volatile memory technology having response (read and write) times comparable to volatile memory. Data stored in MRAM does not degrade over time and, compared to other RAM technologies, MRAM uses very little power. In contrast with conventional RAM technologies, which store data as electric charges or current flows, MRAM uses magnetic storage elements. Thus, MRAM has several desirable characteristics that make it a candidate for a universal memory, such as high speed, high density (i.e., small bitcell size), low power consumption, and very little logic state degradation over time.
Despite the characteristics described above, conventional MRAM devices are not perfect. A conventional memory element (e.g., a magnetic tunnel junction (MTJ)) in a spin-transfer-torque MRAM (e.g., a STT-MRAM) is a two-terminal device having shared read and write paths. The shared read and write paths create problems for read speed and write reliability. For writing, the barrier layer in the MTJ should be sufficiently thin (and have relatively low enough resistance) to flow a current necessary for switching. However, a thin barrier layer is more susceptible to dielectric breakdown due to repeated write operations. Also, a state of an MTJ can be flipped unintentionally by a read current. This is called a "read disturbance." As MTJ technology scales down in physical size, switching current tends to decrease. However, high-speed read operations typically require more read current. Therefore, high-speed MRAM, and particularly deeply-scaled MTJ devices, may suffer from a read disturbance. Accordingly, it is challenging to meet reliability requirements for both write endurance (due to strain on a tunnel barrier in the MTJ) and read reliability.
Spin orbit torque based MRAM devices show switching speeds down to about 200 ps, making them usable for L1/L2 cache applications. Another key aspect of these devices is that they do not suffer endurance issues since read and write current paths are separated. The read currents are, in general, an order of magnitude lower than write currents in two terminal MRAM devices. By eliminating the large write switching current SOT memory removes a large stress on the MgO barrier layer, thereby improving reliability and endurance.
Such devices, however, have a data density drawback. First, they are three terminal device and therefore require three transistors. Second, the writing current density through the spin orbit torque material for these structures can be as high as 1-2×108 A/cm2. This may require switching currents on the order of few hundred micro amps (e.g. about 100-400 micro amp) for generic spin orbit torque layers. This increases the transistor size significantly hence making it very costly. Reducing the cross section of the spin orbit torque layer and the size of the transistor has paramount importance to finding suitable applications.

High density spin orbit torque magnetic random access memory

Integrated Silicon Solution, (Cayman) Inc.


A method for converting OFF (object file format) from three-dimensional polygon data into a quad edge data structure which includes a step to determine if an input triangle of object file format is a whole new triangle, a step to find two edges and perform splice operation if the input triangle is a whole new triangle in the determination step, a step to find a quad edge from vertex link of quad edge data structure if the input triangle is not a whole new triangle in the determination step, and a step to find a candidate edge for a splice operation by comparing the link generated in the preprocessing stage and the vertex link of quad edge data structure and performing the splice operation on the candidate edge and the new quad edge.

The present invention relates to a method for converting OFF (object file format) from three-dimensional polygon data into quad edge data structure.
Generally, typical shapes of data in computer graphics are three-dimensional polygons or triangles.
Three-dimensional polygons and triangles are displayed on a computer screen through a rendering process, which requires an efficient algorithm.
Three-dimensional polygon data are generated, modified, or added in application areas such as rendering, virtual reality, and animation.
To perform such operations efficiently, various data structures have been proposed, and quad edge data structure is one of them.
Quad edge data structure is an edge-based data structure and is able to describe graph and dual graph at the same time. In addition, quad edge data structure employs a splice operator, which is a topological operator.
Even though quad edge is a sufficient data structure for its purposes, an efficient method converting conventional data structure into quad edge data structure has not been discovered.
A method for converting OFF (object file format) of three-dimensional polygon data into a quad edge data structure is provided.
The method in accordance with an embodiment of the present invention includes the following steps. A first step is to determine if an input triangle in object file format is a whole new triangle. An additional step is to find two edges and perform a splice operation if the input triangle is a whole new triangle in the determination step. The two edges are connected with a vertex. A step is to find a quad edge from a vertex link of the quad edge data structure if the input triangle is not a whole new triangle in the determination step. The vertex link has a counterclockwise sequence. A further step is to find a candidate edge for a splice operation by comparing the link generated in the preprocessing stage and the vertex link of the quad edge data structure and performing the splice operation on the candidate edge and a new quad edge.
The method implemented in a computer system in accordance with an embodiment of the present invention includes the following steps. A first step is to determine if an input triangle of object file format is a whole new triangle. An additional step is to find two edges and perform a splice operation if the input triangle is a whole new triangle in the determination step. The two edges are connected with a vertex. A further step is to find a quad edge from a vertex link of the quad edge data structure if the input triangle is not a whole new triangle in the determination step. The vertex link has a counterclockwise sequence. Another additional step is to find a candidate edge for a splice operation by comparing the link generated in the preprocessing stage and the vertex link of the quad edge data structure and performing the splice operation on the candidate edge and a new quad edge.

Method for converting three-dimensional polygon data into quad edge data structure

Electronics and Telecommunications Research Institute

Chungsol APT 514-603 Songkang-Dong, Yusung-Gu

Hanmaul APT 200-4 Songkang-Dong, Yusung-Gu

Hanaro APT 101-905 Wolpyung 3-Dong, Seo-Gu

Hanbit APT 126-1005 Auen-Dong, Yusung-Gu

Hanaro APT 109-806 Wolpyung 3-Dong, Seo-Gu

Chungku-Narae APT 107-203 Junmin-Dong, Yusung-Gu


A multilayer wiring board includes a first dielectric layer, a high-frequency signal line formed on a first surface of the first dielectric layer, a ground layer formed on a second surface of the first dielectric layer, and a second dielectric layer covering part of the ground layer. The high-frequency signal line is electrically connectable to a center conductor of a coaxial structure. The second dielectric layer is spaced from an edge of the first dielectric layer to which the coaxial structure is to be connected, so that a ground exposure portion of the ground layer is exposed on the edge of the first dielectric layer. The ground layer is electrically connectable directly to an outer conductor of the coaxial structure at the ground exposure portion.

1. Field of the Invention
The present invention relates to a multilayer wiring board used for a high-frequency signal interface or the like, and more particularly to a multilayer wiring board to which a coaxial structure such as a connector is connected.
2. Description of the Related Art
In recent years, demands for reduction in device scale have increasingly grown in applications for various communication devices used in wireless or optical communication systems. Size reduction is also necessarily required for circuit boards for communication devices and high-frequency device modules. Therefore, the dimension of high-frequency connectors used as internal or external interfaces of communication devices is desired to be reduced. As one of connectors that meet such market demands, a small-sized connector such as a push-on SMP connector or a push-on SMPM connector has been put into practice. Furthermore, such a small-sized connector has heretofore been mounted directly on a circuit board. See, e.g., JP-A 2004-363593.
When a small-sized connector is mounted directly on a circuit board, a center conductor of the small-sized connector is brought into close contact with a high-frequency signal line of the circuit board. An outer conductor of the small-sized connector is brought into close contact with a ground electrode of the circuit board, which is formed on the same plane as the high-frequency signal line. When a ground layer is formed on a rear face of a circuit board as in the case of a microstrip line, a ground electrode formed on a front face of the circuit board is electrically connected to the ground layer formed on the rear face of the circuit board via through holes. In this manner, connection of high-frequency signals is established between the small-sized connector and the circuit board.
Meanwhile, what is called a multilayer wiring board is used in order to enhance the functionality of communication devices within a limited space. A multilayer wiring board is formed of a multilayered substrate, and a control signal line is also incorporated in the same substrate while the transmission characteristics of high-frequency signals are maintained. FIGS. 1A and 1B show a conventional example of a multilayer wiring board. As shown in FIGS. 1A and 1B, a multilayer wiring board 200 has a dielectric layer 500, a high-frequency signal line 400 formed on a surface of the dielectric layer 500 for transmitting high-frequency signals, and a ground layer 600. Additionally, the multilayer wiring board 200 has a control signal layer 900 for forming a control signal circuit that controls devices mounted on the multilayer wiring board 200. Thus, in view of size reduction and space saving of a communication device, it is important to effectively combine the multilayer wiring board 200 with a small-sized connector for a high-frequency device module.
In a high-frequency region, the characteristic impedance is likely to be discontinuous at a connection portion between a small-sized connector and a multilayer wiring board. Particularly, in a case where high-speed data signals over 10 Gb/s are transmitted, the signal band is so wide as to arise a serious problem of quality degradation of signal waveforms that is caused by discontinuous characteristic impedance. For example, in the conventional device illustrated in FIG. 5 of JP-A 2004-363593, the amount of signal reflection increases at a discontinuous point of the characteristic impedance, thus deteriorating the flatness of the transmission-frequency characteristics. As a result, the waveform quality of high-speed data signals is degraded.
Furthermore, in the case of the multilayer wiring board illustrated in FIGS. 1A and 1B, when a small-sized connector 100 is mounted onto the multilayer wiring board 200, a center conductor 300 of the small-sized connector 100 is connected to the high-frequency signal line 400 formed on the surface of the dielectric layer 500. Projecting portions 1000A of an outer conductor 1000 of the small-sized connector 100, which serves as a ground, are connected to ground electrodes 1200 formed on the surface of the dielectric layer 500. In order to exert a function of the high-frequency signal line 400, the ground electrodes 1200 on the dielectric layer 500, which also has the high-frequency signal line 400 formed thereon, are electrically connected to the ground layer 600 via a plurality of through holes 130.
However, each of those through holes 130 has a thickness corresponding to the thickness of the dielectric layer 500 and thus has a finite inductance. Therefore, provision of many through holes cannot sufficiently reduce a ground inductance at a connection portion between the coaxial structure (connector) and the circuit board. Accordingly, impedance discontinuity thus caused results in deterioration of frequency characteristics in transmission of high-frequency signals. Furthermore, for wide-band and high-frequency signals, such as high-speed data signals, variations in location and dimension of the through holes 130 being formed exert additional influences, make it difficult to obtain good frequency characteristics.


Special reproduction data from a special reproduction data generating circuit is applied to a special reproduction data arranging circuit. A frame-change flag that changes for unit of frame and a positional sequence signal that is initialized by the frame-change flag and is incremented in unit of special data of a special reproduction data position are supplied to the special reproduction data arranging circuit. The special reproduction data arranging circuit arranges dummy data instead of the next frame data on the subsequent special reproduction data positions when a frame is changed so that a positional sequence signal is not initialized more than twice in one repetitive recording area. Thus, it becomes possible to rearrange data using a positional sequence signal in the reproduction.

Digital processing of images has been studied in recent years. Various systems for recording digital image data with magnetic recording/reproducing apparatus (referred to as a VCR, hereafter) have been also studied. In general, when video signals are digitized, the amount of information becomes enormous and the transmission or recording, etc. of information without compression is difficult from the aspects of communication speed and expenses, etc.
Because of the above, image compression technology is indispensable in the transmission or recording of digital video signals and various drafts of standards have been examined in recent years. The MPEG (Moving Picture Experts Group) system has been standardized for moving pictures. In this MPEG system, video signals are encoded using a combination of DTC (Discrete Cosine Transform) conversion, inter-frame predictive encoding, run-length encoding and entropy encoding. That is, in the MPEG system, video signals are not only compressed in one frame by DCT (the intra-frame compression), but also inter-frame compression for reduction of redundancy in the time axis direction using the inter-frame correlation is adopted. Inter-frame compression further reduces bit rate by encoding a difference between two successive frames utilizing the nature of general moving pictures that they resemble closely in the preceding and succeeding frames. In particular, motion compensated inter-frame predictive encoding for reducing predictive error by obtaining an inter-frame error by predicting the motion of a picture is effective.
A helical scanning type VCR reads information recorded on a magnetic tape by tracing the recording tracks formed on the magnetic tape by the rotary drum heads. In normal reproduction, the head tracing agrees with the recording tracks and no special problem is produced. However, in high speed reproduction, the head traces the recording tracks while crossing them. Accordingly, in high speed reproduction only information recorded on such portions wherein each head agrees with the recording track azimuth. Even in this case, in an analog recording where positions on a picture correspond to the recorded positions on a recording medium, it is possible to reproduce one frame.
However, if the amount of encoded intra-frame compression frames and inter-frames compression frames differ and image data compressed according to the MPEG system is recorded on a recording medium, the vertical position of the image data on the picture does not correspond to the vertical recording position on a recording medium and it is not necessarily possible to reproduce one frame from reproduced data in the high speed reproduction. Furthermore, since the inter-frame compressed data cannot be decoded from a single individual frame, reproduction may become impossible if the same frames are unable to be decoded in the high-speed reproduction.
So, in the specification of the Japanese Patent Application (TOKU-GAN-HEI) No. 6-065298 previously filed by the applicant of this patent application, a method for intermittently recording data for high-speed reproduction at track positions (hereinafter referred to as a special reproduction data position) through which the heads run across them in high-speed reproduction is proposed. During reproduction, high-speed special reproduction images are obtained by accurately tracing the data positions whereon the high speed special reproduction data are recorded. For instance, to enable four-times speed mode reproduction, important data are to be recorded on special reproduction data positions from where a sufficient envelope level is obtained in the four-times speed mode reproduction.
In the proposal described above, three kinds of signals of frequency f0, f1, f2 (hereinafter referred to as pilot signals f0, f1, f2) are used as pilot signals for tracking and the pilot signals f1, f0, f2, f0, f1, f0, f2, f0, . . . are recorded on each track by superposing them in that order. During reproduction, levels of the pilot signals f1, f2, f3 contained in reproduced signals are compared and so controlled that the compared levels match with each other, that is, to agree the track phase with the tracks on which the pilot signal f0 is superposed. In this case, it is possible to match the track phase with the track of the pilot signal f0 every four tracks if the shifting direction of track phase is considered.
It is possible to match the track phase with a track of the pilot signal f0 even in, high-speed mode reproduction Therefore, the trace line of the head in high-speed mode reproduction is decided according to the tracks of the pilot signal f0. By recording high-speed mode reproduction data on the thus decided trace line, high-speed mode reproduction is enabled.
In high-speed mode reproduction, the heads of the same azimuth will trace across two times of given special reproduction speed number of tracks. Accordingly, it is better to record data next to that data recorded on the specified special reproduction data position in the same positions on following tracks after the two times of the specific reproduction speed number of tracks. Further, the heads trace the same azimuth tracks by every four tracks. Therefore, making sure to reproduce data even when the trace is carried out at any portion on the two times of special speed number of tracks (hereinafter referred to as a repetitive recording area), it is necessary to repetitively record the same data on four tracks in the repetitive recording area.
FIG. 8 is an explanatory diagram for explaining the recording on the special reproduction data position.
In FIG. 8, assuming that tracks run in the vertical direction, the special reproduction data positions on each track are given by square symbols. The arrows in FIG. 8 show the trace lines by the same azimuth head in the four-times speed mode reproduction. As described above, the same data is recorded on the same position in each track of every four tracks in the repetitive recording area and as the trace lines cross the four tracks in the four-times speed mode reproduction, four pieces of data can be recorded on the special reproduction data positions in one repetitive recording area. That is, in FIG. 8 the special reproduction data position is provided to every track so that data can be reproduced from four special reproduction data positions on four tracks by one trace. For instance, as shown in FIG. 8, frames 0 through 3 are recorded in the repetitive recording area A0 and data 4 through 7 are recorded in the repetitive recording area A1.
In the repetitive recording area A1, data 5, 6 and 7 are reproduced along the trace line T1, while data 4 is reproduced along the trace line T2. When rearranging the reproduced data in order of data 5, 6, 7 and 4, the original data 4, 5, 6 and 7 can be restored. For facilitating this rearrangement, a positional sequence signal is added to each data. Figures at the sides of the square symbols in FIG. 8 show the positional sequence signals.
That is, frame data with the positional sequence signals 0, 5, 6 and 7 are sequentially reproduced along the trace line T1. While, frame data with the positional sequence signals 4, 9, 10 and 11 are sequentially reproduced along the trace line T2. FIG. 9 shows the positional sequence signals of reproduction data that are sequentially reproduced for each trace. As shown in FIG. 9(a), the positional sequences of the reproduction data by the traces around the repetitive recording area A1 have the order of . . . 1, 2, 3, 0, 5, 6, 7, 4, 9, 10, 11, 8, 12 . . . . When this reproduction data train is rearranged in order of the positional sequence signals, the reproduction data in the original data sequence can be obtained as shown in FIG. 9 (b).
Further, considering the reverse reproduction, a frame-change flag showing the frame change is also recorded. That is, in the reverse reproduction it is necessary to reproduce data in a frame in the positive sequence while reproduce them in unit of frame in the reverse sequence. Therefore, a frame-change flag is used to restore reproduction data in unit of frame. FIG. 9(b) shows that the frame-change flags are at the same level and there is no frame change.
Further, considering that data around the frame ends are recorded on mid-tracks or end-tracks in the repetitive recording area, the positional sequence signal is initialized at the timing of the frame change given by the frame-change flag.
By the way, in the MPEG system, etc. a relatively large data storage is normally needed for recording data for one frame and a plurality of repetitive recording areas are needed for recording one frame. However, in the progressive refresh system disclosed in the literature "Grand Alliance HDTV System Specification" submitted to the ACATS Technical Subgroup; 2, 22, 1994, pictures are updated in unit of slice of the MPEG data. Therefore, when this system is adopted, the amount of data in one frame of the special reproduction data becomes relatively small and the frame changes may be frequent.
However, there was a problem in this case that the data rearrangement could not be made properly. FIG. 10 is a diagram for explaining this problem.
In FIG. 10 it is also assumed that the tracks run in the vertical direction and the special reproduction data portion on each track is given by the squares. Further, the special reproduction data positions shown by the thick square symbol indicates that data at the top of frame (the frame starting point data) are recorded and numerals in the squares show the frame numbers. Further, figures at the sides of the squares show the positional sequence signals. In FIG. 10, the 0-th through the fourth frame data are recorded in repetitive recording areas A0 to A2.
As shown in FIG. 10, three special reproduction data positions except the special reproduction data positions at the lowest end of the repetitive recording area A0 and the lowest end of the repetitive recording area A1 are traced along the trace line T1. Further, three special reproduction data positions except the special reproduction data position at the lowest end of the repetitive recording area A1 and the lowest end of the repetitive recording area A2 are traced along the trace line T2. The frame starting point data given by the thick square symbol is set to 0 since the positional sequence signal was initialized.
FIG. 11 (a) shows the reproduction data train obtained from the trains. The positional sequence signals of the reproduction data to be reproduced sequentially along the trace line T1 are 1, 0, 1, 2, respectively. The positional sequence signals of the reproduction data to be sequentially reproduced along the trace line T2 are 0, 1, 0, 1, respectively. FIG. 11(b) shows the frame numbers of these reproduction data. As shown in FIG. 11 (c), the positional sequence signal of the first reproduction data along trace line T1 is 1, this data is arranged before the reproduction data of the upper three special reproduction data positions on the repetitive recording area A0 and the reproduction data of the 0-th frame is properly arranged.
However, other positional sequence signals are arranged in the properly sequence as shown in FIG. 11 (a), and the reproduction data can not be rearranged. That is, the reproduction data of the first frame reproduced along trace line T2 is arranged between the last reproduction data of the second frame and the reproduction data of the third frame. Similarly, the third reproduction data by trace line T2 is the fourth frame data, but since the positional sequence signal is 0, it is arranged before the first data (the positional sequence signal in 0) of the third frame that is first reproduced by the next trace (not shown).
Thus, in a conventional method for rearranging special reproduction data using frame-change flags and positional sequence signals that are initialized at the changing point of frame-change flags, there was such a problem that data may not be rearranged properly if the amount of data of special reproduction data for one frame is small.

Magnetic recording/reproducing apparatus and data arranging method for use in the apparatus


Provided is a composite material suitable for forming a part for continuous casting capable of producing cast materials of excellent surface quality for a long period of time and with which a molten metal is inhibited from flowing into a gap between a nozzle and a moving mold.

Continuous casting has been known in which a molten metal melted in a melting furnace is supplied to a moving mold constituted by rolls, belts, etc., from a tundish, and cooled and solidified by being brought into contact with the moving mold so as to continuously produce cast materials. Molten metal is supplied to the moving mold via a nozzle. Examples of this nozzle for casting include those described in Patent Literatures 1 and 2. In Patent Literature 1, a nozzle having a tip having a three-layer structure that includes a high-heat-conductivity layer, a low-heat-conductivity-layer, and a high-strength elastic layer is disclosed which reduces variation in the temperature of the molten metal in the width direction of the material during casting. Patent Literature 2 discloses a nozzle suitable for use in continuous casting of pure magnesium or magnesium alloys. This nozzle includes a main body composed of an oxide material in order to prevent reaction between the nozzle-forming material and the molten metal of magnesium which is an active metal, and a coating layer composed of a low-oxygen material and disposed on a surface of the main body that contacts the molten metal.

Composite material, part for continuous casting, continuous casting nozzle, continuous casting method, cast material, and magnesium alloy cast coil material

Abstract: A composite material (nozzle 1) includes a porous body 2 having a large number of pores and a filler incorporated in at least part of a portion that comes into contact with the molten metal, the portion being part of a surface portion of the porous body. The filler incorporated in the porous body 2 is at least one selected from a nitride, a carbide, and carbon.