A system and method for control of so-called KARAOKE equipment whereby the musical key of the pre-recorded accompaniment music may be altered automatically to substantially coincide with the analyzed or given vocal range of the singer, for example, soprano, tenor, mezzo-soprano, baritone, alto or bass, or with the preferred key to be sung entered by the singer, for example, E key, so as to eliminate the trial-and-error manual key adjustments during singing.

So-called KARAOKE systems are known, in which one or more singers sing a song while being accompanied by a pre-recorded music composition. Typical KARAOKE equipment contains a plurality of manual switches to enable the operator to set the echo/reverberation, key shifter, tone, and volume adjustments prior to or during playing the music composition. The operator or moderator, sometimes called a disc-jockey (D.J.), asks the singer what key he/she sings in and then activates the key switch believed to be the singer's vocal key range. The prior art KARAOKE equipment enables manual adjustment of the key (shifter).
Not infrequently, however, the amateur singer does not know his/her singing key or provides the operator with a wrong key. In addition, the key in which the pre-recorded musical piece was performed/recorded is typically unknown to the KARAOKE singer and the operator. Accordingly, the KARAOKE experience of such singers singing off-key with the music can be embarrassing and may result in diminished participation by other would-be KARAOKE singers.
Further, a singer's voice may not exactly coincide with one of the six conventional keys. The prior art KARAOKE equipment is limited to manual key adjustment by trial-and-error technique as the KARAOKE music is being played. Typically, a KARAOKE singer is subjected to several trial runs, which may be embarrassing, in an attempt to select the best suited key shift adjustment of the KARAOKE singer's voice. Such embarrassing trial runs may be avoided by use of the present invention.

Automatic musical key adjustment system for karaoke equipment


Described embodiments provide a method for calibrating a continuous-time filter having at least one adjustable parameter. A square-wave signal is filtered by a continuous-time filter having a cutoff frequency less than fs. The filtered signal is quantized at the rate fs. An N-point Fourier transform is performed of the quantized signal into N real output values and N imaginary output values. At least one of the real output values are accumulated to form a real output signal and at least one of the imaginary output values are accumulated to form an imaginary output signal. The real and imaginary output signals are summed to form an output signal, which is then squared. The squared output signal is compared to a comparison value. At least one parameter of the continuous-time filter is adjusted based upon the comparison. The steps are repeated until the squared output signal is approximately the comparison value.

1. Field of the Invention
The present invention relates to generally to continuous-time filters for signal processing, and, in particular, to a method and system for tuning precision continuous-time filters.
2. Description of the Related Art
Continuous-time filters are commonly used in communications systems, especially high frequency communication systems and magnetic storage read channels. One possible implementation of a high frequency continuous-time filter is a transconductance-capacitance ("Gm-C") filter. A Gm-C filter consists of a transconductance (Gm) element and a capacitor (C). In this example, the transconductance element is characterized by the equation Iout=Gm*Vin, where lout is the output current, Vin is the input voltage, and Gm is the transconductance or gain of the element. This output current lout is applied to capacitor C to produce an output voltage. The voltage across capacitor C varies in accordance with the current through the capacitor, and the current through capacitor C varies in accordance with the voltage applied to the transconductor, thus creating a frequency dependent filter.
One type of Gm-C filter is a Gm-C biquadratic ("Gm-C biquad") filter. A Gm-C biquad filter is a second-order recursive linear filter, meaning that its transfer function is the ratio of two quadratic functions and, thus, has two poles and two zeros. Higher-order recursive filters may be implemented using serially cascaded Gm-C biquad filters. Gm-C biquad filters are commonly used in tunable continuous-time band-pass filter applications. An example of such a Gm-C biquad filter can be found in the paper by Uwe Stehr & Frank Henkel, et al., A FULLY DIFFERENTIAL CMOS INTEGRATED 4TH ORDER RECONFIGURABLE GM-C LOWPASS FILTER FOR MOBILE COMMUNICATION, Proceedings of the 2003 10th IEEE International Conference on Electronics, Circuits and Systems, Vol. 1, pp. 144-147, (Dec. 14-17, 2003), which is incorporated herein by reference in its entirety.
The parameters of a Gm-C filter can vary with process, voltage and temperature ("PVT") conditions. For instance, the value of Gm is dependent upon operating temperature, process variations such as transistor doping levels, and production variations such as transistor channel width, transistor channel length, etc. Thus, in applications requiring high accuracy, the Gm-C filter must be tuned to take the PVT variations into account to maintain proper cutoff frequency and quality factor of the filter. Existing methods of maintaining accuracy across PVT variations include manual tuning methods, analog tuning loops, and phase/edge rate detection. However, these existing methods can be cumbersome and may not maintain high accuracy.

Method and system for tuning precision continuous-time filters


A sunless tanning composition having dihydroacetone and an amphoglycinate (amphoacetate) in an amount effective for sunless tanning is provided. Also provided is a method of sunless tanning having the step of topically applying to the skin an effective amount of a sunless tanning composition having dihydroacetone and an amphoglycinate.

1. Field of the Invention
The present invention relates to a sunless tanning composition and its use in sunless tanning products. More particularly, the present invention relates to a method of sunless tanning that employs the sunless tanning composition according to the present invention and provides fast development of uniform, more intense, long-lasting and natural looking tan with more predictable, i.e., customized, color characteristics.
2. Description of the Related Art
U.S. Pat. Nos. 5,645,822 and 5,750,092 to Schering-Plough and European Patent Application No. 0 547 864 A1 describe attempts to provide sunless tanning. However, these and other approaches described in the art have certain drawbacks.
Products that are currently used for sunless tanning of the skin are based on the reaction of an active chemical present in the product with the skin amino acids. Such chemicals are well known and include compounds having an aldehyde group, or compounds having a ketone group, such as, for example, Dihydroacetone.
As an example, DHA gives skin a brownish color by reacting with the amino acids present in the sebum and stratum corneum by a known mechanism, namely the Maillard reaction.
Further, distribution and nature of the amino acids is not uniform on the surface of the skin and because of that the intensity and shade of the color obtained may vary from one place to another on the treated skin thereby causing the skin to have an unnatural look.
Further still, the duration of time required for development of skin color may be too long, which can lead to a decrease in the concentration of DHA on the surface of skin due to sweating or as a result of contact with clothing thereby staining the clothing and resulting in an uneven color development on the skin.
Thus, it is very desirable to obtain a uniform and natural looking sunless tan over all skin surfaces that are treated with a sunless tanning composition that can develop faster and last longer than formulations known in the art.
Thus, there is a need in consumer products and cosmetic industry for formulations that can enhance the effectiveness of the active ingredient used in sunless tanning and deliver increased performance characteristics and eliminate the need for exposure to damaging rays of the sun for tanning.

Sunless tanning composition and method of sunless tanning


A catalyst for hydrazinolysis having high catalytic activity and long life concurrently with high thermal resistance is disclosed. The catalyst is composed of an alumina support having a substantially extended specific surface area and iridium being substantially supported thereon. The alumina support is prepared by the steps of adding aluminum alkoxide into hexyleneglycol (2-methyl-2, 4-pentanediol), heating at temperatures between 100.degree. and 200.degree. C. to form a sol, hydrolyzing the sol to a gel, and drying and calcining the gel.

1. Field of the Invention
The present invention relates generally to a method for preparing a hydrazinolysis catalyst. Specifically, the present invention relates to a method for preparing a hydrazinolysis catalyst wherein a specific surface area thereof is extended.
2. Description of the Background Art
Hydrazinolysis is a well known reaction in the art as indicated in the following reaction formula: EQU N.sub.2 H.sub.4 .fwdarw.N.sub.2 +2H.sub.2
Alternatively; EQU 3N.sub.2 H.sub.4 .fwdarw.4NH.sub.3 +N.sub.2 EQU 2NH.sub.3 .fwdarw.N.sub.2 +3H.sub.2.
The above mentioned reaction is catalyzed by hydrazinolysis catalysts which are conventionally composed of iridium (Ir) supported on an inorganic catalyst support. Generally, 30 to 40 wt % of Ir is substantially dispersed on an alumina support having a diameter of 25 to 30 mesh, formed by a conventional technique such as thermal decomposition. Hydrazine is decomposed as shown in the above reaction when contacting the surface of the Ir.
Generally, the thrust of a hydrazine thruster for combustion in a rocket engine, for example, can be obtained from the aforementioned decomposition reaction.
However, there are certain problems when using the above conventional catalyst. The specific surface area of the alumina support formed by the conventional technique limits the amount of Ir supported thereon. When large amount of Ir is supported on the surface, homogeneous dispersion of the Ir thereon cannot be assured, consequently, dispersion availability of Ir becomes lower corresponding to the amount of Ir which is supported. Thus, catalytic activity of the hydrazinolysis catalyst is reduced, that is, because of the characteristics of the alumina, the thermal resistance of the catalyst is relatively low, so that catalyst life is limited.

Method for preparing hydrazinolysis catalyst

Agency of Industrial Science and Technology


There is provided a honeycomb filter obtained by bonding, into one piece, a plurality of honeycomb segments comprising partition walls having filtering function, and a number of through-holes divided from each other by the partition walls and extending in an axial direction. Predetermined through-holes are plugged at one end face of the filter, and the remaining through-holes are plugged at the other end face of the filter. The honeycomb filter is characterized in that the honeycomb segment disposed in a peripheral portion of the honeycomb filter has a lower average bulk density than that of the honeycomb segment disposed in a central portion.

Honeycomb filters are in use in, for example, a filter for capturing fine particles present in exhaust gas emitted from an internal combustion engine, a boiler or the like, particularly, particulate matter in exhaust gas emitted from diesel engine.
The honeycomb filter used for such a purpose generally has, as shown in FIGS. 10(a) and 10(b), a structure having a large number of through-holes (3) extending in an X axis direction divided from each other by partition walls (2), and through-holes (3) are alternately plugged at each end face so that each end face looks checkerboard pattern. In such a honeycomb filter, a subject fluid flows in the through-holes (3) not plugged at inflow end face (42), that is, plugged at outflow end face (44), passes through the porous partition walls (2), and is discharged via the adjacent through-holes (3), that is, the through-holes (3) plugged at the inflow end face (42) and not plugged at outflow end face (44). In this case, the partition walls (2) act as a filter. For example, soot discharged from a diesel engine is captured by the partition walls and deposited on the partition walls. In the honeycomb filters used in such a condition, there was such a problem that the sharp temperature change of exhaust gas and the local heating made non-uniform the temperature distribution inside the honeycomb structure and caused cracks in a honeycomb filter. When the honeycomb filter is used particularly as a filter for capturing particulate matter in exhaust gas emitted from a diesel engine (this filter is hereinafter referred to as DPF), it is necessary to burn the carbon particles deposited on the filter to remove the particles and regenerate the filter and, in that case, there was such a problem that high temperatures were inevitably developed locally in the filter to deteriorate regeneration efficiency due to non-uniformity of regeneration temperature as well as to cause cracks due to large thermal stress. Further, non-uniform temperature distribution during regeneration made it difficult for the whole portion of the filter to have at an optimum temperature and also made it difficult to have high regeneration efficiency.
Hence, there have been proposed processes for producing a honeycomb filter by bonding a plurality of individual segments using an adhesive. In, for example, U.S. Pat. No. 4335783 is disclosed a process for producing a honeycomb structure, which comprises bonding a large number of honeycomb parts using a discontinuous adhesive. Also in JP-B-61-51240 is proposed a thermal shock resistant rotary regenerative heat exchanger which is formed by extrusion molding matrix segments of honeycomb structure made of a ceramic material; firing them; making smooth, by processing, the outer peripheral portion of the fired segment to form a bonding surface; coating the bonding surface with a ceramic adhesive which turns, after firing, to have substantially the same chemical composition as the matrix segment and a difference in thermal expansion coefficient of 0.1% or less at 800 degree C.; loading the required number of segments; and firing the coated segments. Also in the SAE paper 860008 of 1986 is disclosed a ceramic honeycomb structure obtained by bonding cordierite honeycomb segments with a cordierite cement. Further, in JP-A-8-28246, a ceramic honeycomb structure is disclosed in which a certain number of honeycomb ceramic members are bonded by an elastic seal material including at least a three-dimensionally crossing inorganic fiber, an inorganic binder, an organic binder, and inorganic particles. It was also tried to produce a honeycomb filter using, for example, a silicon carbide based material of high thermal conductivity and high heat resistance, in order to prevent it from localized high temperature to prevent breakage due to thermal stress.
By using segment and/or a highly heat-resistant material such as silicon carbide based material, the damage caused by thermal stress could be prevented to some extent. However, the temperature difference between the outer peripheral portion and center of honeycomb filter could not be eliminated, and improvement in regeneration efficiency by uniform regeneration was insufficient. Further, local heating appeared during regeneration, in some cases.


A multimode detection system for detecting one or more samples is provided. The detection system comprises an electromagnetic radiation source, a reference arm, and a sample arm comprising a sensing substrate having a plurality of sample fields, wherein the sample fields are configured to receive the one or more samples. The system further comprises a phase difference generator configured to introduce pathlength differences in the reference arm, sample arm, or both, a spatial light modulator operatively coupled to the reference arm, sample arm, or both, wherein the spatial light modulator is configured to modulate incident radiation, resultant radiation, or both in the reference arm, sample arm, or both, and an imaging spectrometer configured to discriminate between two or more spatially separated sample en two or more spatially separated sample fields.

The invention relates to detection and imaging, and more particularly to systems and methods for detection and imaging of one or more samples.
In bio-sensing applications, such as drug discovery and proteomics research, a detection process starts with screening a vast number (a few thousands) of candidates in the form of ligand-receptor or protein-protein interactions that need to be rapidly examined. The screening of the candidates is generally carried out by detection systems that are suitable for high throughput operations, or by configuring a detection system such that it is suitable for high throughput operations. Subsequent to the screening step which is performed at a moderate resolution, a different detection system or detection configuration may be used for a low throughput and high resolution detection. The low throughput and high resolution detection may be used to perform detailed and relatively more reliable detection. Among other changes, reconfiguration of the detection systems may comprise changing one or more components of the system, such as a sensor chip on which the samples are disposed, a fluidic chip that supplies samples to the sensor chip, an optical arrangement of the system, or a detector. Reconfiguration of the system from the low to high resolution may provide enhanced analysis results, however, the reconfiguration of the system results in expensive and time consuming analysis. For example, in some instances switching the resolution may require switching between two or more detection systems. Switching between the two or more detection systems may be time consuming and expensive. In other instances, switching the resolution may require reconfiguration within the detection system. The reconfiguration of the system may be labor intensive, time consuming and expensive.
Therefore, it is desirable to have time efficient and cost effective systems and methods for analysis of one or more samples, where the systems may be configured to operate at high throughput and low throughput modes, and where the systems may be configured to efficiently switch between the high and low resolution modes.

Multimode systems and methods for detecting a sample


Kidney-shaped push up insert including first lobe and second lobe is provided. Notch is formed in top side between first lobe and second lobe. Insert has depression formed adjacent top side extending towards notch. Second main surface opposes first main surface. Second main surface is substantially smooth arcuate-shaped surface. First lobe has narrower width between top side and bottom side than second lobe, and second lobe is thicker between first main surface and second main surface than first lobe. Ratio of maximum thickness between first main surface and second main surface to maximum length between opposing ends of first lobe and second lobe is less than about 9 and/or ratio of depth of notch from a straight line connecting first lobe and second lobe along top side of insert to width of insert from top side to bottom side at depth of notch is less than about 4.

Pads are typically inserted into the cups of a bra to fill out the bra. An example of a plastic pad is shown in FIG. 1, illustrating an approximately semi-circular-shaped pad 10. FIG. 2 illustrates another example of a pad 20 having cloth exterior encasing a foam pad. The cloth/foam pad is thin, about ½ inch thick at its maximum thickness. The outer cloth exterior of the foam pad 20 is secured by stitching 22 around the periphery 24 of the pad 20.
The prior art foam pads do not push up breasts and do not create cleavage and volume. The prior art plastic and foam pads do not wrap around breasts and are not contoured to the breast to create a natural shape. The prior art pads do not anatomically fit the breasts to provide natural-looking, enhanced cleavage. Thus, it would be desirable to provide a soft insert that is anatomically designed to conform to the breasts to provide a better fit, more lift, greater cleavage, and increased volume.


A water circulation system for a swimming pool includes a venturi skimmer; a pump with a suction side and a discharge side; a suction drain; a pool return line; and at least one pool inlet fluidically connected to the pool return line. A pump inlet on the pump suction side has an inlet selector to fluidically connect the pump to the venturi skimmer, the suction drain, or a combination of the venturi skimmer and the suction drain. In addition, pump outlet on the pump discharge side has an outlet selector to fluidically connect the pump to the venturi skimmer, the pool return line, or a combination of the venturi skimmer and the pool return line. The pump is a multispeed pump or a variable speed pump. Also provided is a method of circulating water for a swimming pool generally comprising this circulation system.

1. Field of the Invention
The following invention is directed toward circulation systems for swimming pools.
2. Discussion of the Related Art
For the past 40 odd years the standard pool circulation system on swimming pools has not advanced significantly for standard pools that do not have a built in cleaning system. There have been advancements in pumps, filters, chlorinators etc, but little has been done to improve pool circulation in terms of establishing effective circulation of water within the pool for more effective cleaning and improving the energy efficiency of the system.
The standard pool circulation system has a pump that draws water from a suction skimmer (usually located in the deep end wall of the pool), pushes the water through a filter, and then the water is returned to the pool via a number of wall directional eyeball fittings (usually located in the shallow end wall of the pool). These eyeball fittings can be oriented in various directions in an attempt to get the water moving within the pool.
FIG. 1 provides a general schematic of a standard pool circulation system. This system comprises a standard suction skimmer, a main drain, a standard pool pump system, a pool filter and a return line. The standard pool circulation system usually results in satisfactory circulation of the surface water as well as a majority of the shallow end water. However, dead spots or dead zones are common in the deeper parts of the pool due to the circulation system being ineffective at establishing the circulation of water in these deeper regions.
FIG. 2 provides a general schematic of a typical in-floor plumbing system of a standard pool circulation system. The typical in-floor plumbing system uses two pumps. Two pumps are required to reduce the overall pressure load on the system, and in particular on the filter. One of the pumps recirculates water from the main drains, via a filter and eyeball returns. A second pump is required to recirculate water from the skimming device. Because two pumps are used with independent loops, the pressure applied across the filter is far less than with the single pump system. This can result in the filter having a longer operational life. When one pump is used, it needs to be sized such that it can draw and redistribute water from the skimmer and main drains simultaneously. In this case, the pump needs to be comparatively large. In contrast, with a two pump system, each pump is smaller and can be operated independently of the other pump. However, to maintain a satisfactory level of cleaning in the pool system, it is necessary to operate the pump system recirculating the water from the main drains, and the pump system recirculating water from the skimmer at the same time. By way of comparison, a typical two pump system will require a first pump of approximately 1 horsepower drawing from the main drain, and a second pump of approximately 1.5 to 2 horsepower drawing from the skimmer unit. The total combined power requirement of such a two pump system is approximately 2.5 to 3 horsepower. In contrast, a comparable one pump system would require a pump with a power requirement of approximately 2 to 2.5 horsepower. Generally, one pump systems have a power requirement that is around 0.5 horsepower less than a two pump system. Thus a dual pump system is generally less efficient than the single pump system above, and can be more expensive in terms of capital costs and ongoing maintenance costs.
There is ongoing demand to further increase the efficiency of pool recirculation systems by both lower the operating costs and improving the circulation of water within the pool.
Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art.


A vitrified superabrasive grain grinding stone includes superabrasive grains including a CBN abrasive grain as a main abrasive grain and a diamond abrasive grain as an auxiliary abrasive grain bonded together by use of a vitrified bond. The auxiliary abrasive grain has an average grain diameter equal to ½ to 1/10 of that of the main abrasive grain, and the auxiliary abrasive grain has a toughness value of 0.4 to 1 when that of the main abrasive grain is given as 1.

A vitrified superabrasive grain grinding stone, because of bonding of superabrasive grains by melting down an inorganic vitrified bond at calcination temperature in the order of, for example, 500 to 1000° C., can have a high abrasive grain holding power, namely, a high adhesive power between the superabrasive grains and the vitrified bond, as compared with the case of using an organic resin bond. For example, in the case of CBN abrasive grain, it is considered that, since B element, and K or Na element, etc., within a catalyst, added during a synthesis process thereof, are present on a surface thereof, these elements react with the vitrified bond and their chemical bonding power heightens the abrasive grain holding power.
Conventionally, out of steel-made work materials, a shaft component such as a camshaft and a crankshaft as a main component of an automobile engine is subjected to a high-precision grinding process for enhancement of performance of the engine but there have been problems of processing deformation, lowered hardness, and residual stress caused to the shaft component as the work material by a grinding heat generated at the time of grinding. As to a general countermeasure to eliminate the occurrence of these problems, proposals are made such as (a) using a clean-cutting grinding stone, (b) reducing an amount of cutting at grinding time, using a porous grinding stone, (c) lessening processing conditions by using a soft grinding stone of a low binding degree, (d) cooling by a sufficient supply of a coolant to a grinding point, and (e) using a grind stone with the CBN abrasive grain and a diamond abrasive grain mixed at various ratios. Such grinding stones are those described, for example, in Patent Document 1, Patent Document 2, and Patent Document 3.


A network service access system and method for intelligent networks uses a network element called a mediation point between network service switching points (SSP) and third party service provider service control points (SCP). The mediation point acts as a gateway to the AIN network for the service provider SCPs. The mediation point at the boundary of the intelligent network has ports for connection to service providers SCPs and a list of SSPs within the intelligent network to which each respective service provider is allowed access.

The Intelligent Network (IN) architecture has been evolved through the efforts of groups, in particular Bellcore, European Telecommunications Standards Institute (ETSI), International Telecommunications Union (ITU-T), and American National Standards institute (ANSI). These groups have issued respective documentation defining general architecture for IN. This evolution is being driven by the increasing demand for rapid and responsive deployment of services on the telecommunications network.
Increasing competition and changing regulations are providing both a challenge and an opportunity to the telecommunications industry. While some interconnections between network providers have existed for a decade or more, and open Network Architecture (ONA) rules and capabilities have been and continue to evolve, new technologies are increasing the sophistication of these interconnections and hence both their value and their power.
In 1992, the Federal Communications Commission (FCC) mandated the Information Industry Liaison Committee (IILC) to begin work on defining the requirements for network unbundling such that other Service Providers could obtain intelligent access to local subscribers through the LEC network. In addition, in 1993, the FCC issued a Notice of Proposed Rulemaking (NPRM) on Common carriers Docket 91-346, to gather industry views on the requirements for regulations regarding the opening of LEC networks at the SCE, SMS, SCP and SSP levels,
To date, service provider access has been technologically difficult to achieve as services have been based on proprietary switches. With intelligent networks (IN), there is an opportunity to provide an open/standard interface whereby service logic in a service control point (SCP) is separated from the switches, (called service switching points (SSPS) in IN).
Initially, the Local Exchange Carriers (LECs) did not intend to use advanced intelligent network (AIN), as defined by Bellcore, to allow competition for services business, but soon recognized this as a new business opportunity. The FCC is aware that there are technology issues that have to be resolved, especially how to protect the integrity/reliability/security of the public switch networks if the intelligent networks are unbundled.

Mediated access to an intelligent network


A rotary electric machine includes a stator, a rotor, a plurality of coils and a plurality of spacers. The stator has a stator body and a plurality of stator poles. Each stator pole has a pair of oppositely facing side surfaces. The rotor is positioned within the stator and has a plurality of rotor poles. One coil is disposed about each stator pole. The spacers are disposed between one coil and at least one of an inner circumferential surface of the stator body and the side surfaces of the stator body to define a fluid flow opening between the coil and the stator.

Work machines may be powered by electrical propulsion systems. The electrical propulsion systems sometimes include electric drive traction systems that provide driving forces to traction devices of the work machines. In some electric drive traction systems, switched reluctance motors are used to provide the driving force.
Switched reluctance motors may have various motor topologies (e.g., the number of stator poles, the number of coils, and the number of rotor poles). In addition, a switched reluctance motor may be configured with a plurality of phases (e.g., 2 phases, 3 phases, 4 phases, or more). A switched reluctance motor may have a plurality of stator poles, each with a winding of electrically conductive wires or coil positioned therearound. The number of wires and the configuration of the coil is one factor that affects the efficiency of the operation of the switched reluctance motor.
The operation of a switched reluctance motor may generate a significant amount of heat within the motor. Cooling of the switched reluctance motors may be performed in many manners. In some instances, convection cooling systems are provided to draw heat from the switched reluctance motors. Improvements in cooling of switched reluctance motors is desirable to increase power generation, efficiency and lifespan.
U.S. Pat. No. 9,621,011 discloses a switched reluctance motor having a stator with a plurality of stator poles having windings thereon and a rotor rotatable relative to the stator. A stator sleeve is located about the stator core and includes a convection reservoir extending along and in a thermally conductive confronting relationship with at least a portion of the windings. A delivery reservoir is provided with a plurality of transfer ports fluidly coupling the convection reservoir with the delivery reservoir.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.

Cooling system for a rotary electric machine


An image sensor includes a semiconductor substrate having a first surface and a second surface, a pixel element isolation film extending through an interior of the semiconductor substrate and defining a plurality of active pixels in the semiconductor substrate, and a dummy element isolation film extending through the interior of the semiconductor substrate and extending along at least one side of the active pixels in a plan view and defining a plurality of dummy pixels in the semiconductor substrate. The pixel element isolation film may have a first end that is substantially coplanar with the first surface and has a first width in a first direction parallel to the first surface, and the dummy element isolation film has a first end that is substantially coplanar with the first surface and has a second width that is greater than the first width of the pixel element isolation film.

The inventive concepts relate to image sensors, and more particularly, to image sensors that include a photodiode.
An image sensor is a device configured to convert an optical image signal into an electric signal. An image sensor may include a pixel region configured to receive incident light and convert the received light into an electric signal, and the image sensor may further include a plurality of photodiode regions and a pad region configured to provide an electrical connection to the pixel region. As the degree of integration of the image sensor increases, the size of each photodiode region of the plurality of photodiode regions decreases and process difficulty increases.


Systems and methods for accurately and securely assembling, storing, and leveraging travel data are provided. A method may include detecting a travel event of a user. The method may include recording the travel event in a travel map that is stored in a database. The travel map may be a temporal- and spatial-based record of one or more travel events of the user. The travel map may be stored as a blockchain ledger. The method may include tokenizing sensitive information associated with the user in the database, and calculating a hazard vector. The method may include updating, based at least in part on the hazard vector, a status index associated with the user, and providing the user and a system administrator access to the travel map and the status index. Access may be provided via an online portal configured to be viewed via an application running on a mobile device.

Traveling may expose a traveler to hazards. Being exposed to the hazards may present a danger to the traveler. Being exposed to the hazards may present a danger to other parties aside from the traveler. The traveler and the other parties may be unaware of the exposure. The traveler and the other parties may be unaware of the danger presented by the exposure.
Travel data may include travelling patterns associated with travelers. Travel data, however, is often inaccurate and not comprehensive. For example, a traveler may travel on one itinerary using one passport and a second itinerary using a second passport. Travel data based on one passport will be incomplete. As another example, an itinerary may indicate that a traveler traveled from a first country to a second country. However, the traveler may, in fact, have originated his or her travel in a third country. Travel data, therefore, may lack important information.
It would be desirable, therefore, to provide computer-based systems and methods for accurately and efficiently assembling and storing travel data. It would be further desirable to leverage the travel data and provide a distributed, digital early warning network that increases the safety and security of travelers as well as those exposed to travelers.

This patent is subject to a terminal disclaimer.

Digital passport with verified data provenance


A biomedical signal instrumentation amplifier is especially suitable for a circuit processing biomedical signals. In a voltage instrumentation amplifier, a biomedical signal level conversion circuit is added to change an input level, reduce signal distortion and noise, and achieve the performance of low voltage, unisource, low noise, high CMRR, and high PSRR.

1. Field of the Invention
The present invention relates to a biomedical signal instrumentation amplifier and particularly to a voltage instrumentation amplifier provided with a biomedical signal level conversion circuit.
2. Description of Related Art
As technology changes with each passing day, a medical instrument is developed without exception. Because the technology of a very large scale integration (VLSI) and the concept of a System-on-a-Chip (SOC) are increasingly known, the valuable, large-scaled medical instrument is gradually being reduced and made more flexible so that it may be not only portable but also cheap and practical, thereby being widely used.
However, since late 1950's, the design and research of a biomedical signal detection system has been gradually regarded, and a biomedical signal instrument amplifier is even essential in the detection system. The biomedical signal is quite weak and different from a general electric signal, so the required biomedical signal instrumentation amplifier is different from a general amplifier.
The bandwidth of biomedical signal is part of low frequency; for example, the frequency of an electrocardiogram (ECG) signal ranges from 0.05 Hz to 100 Hz, that of an electroencephalogram (EEG) signal ranges from 0.5 Hz to 100 Hz, and that of an electro-oculogram (EOG) signal ranges from dc to 100 Hz.
The amplitude of biomedical signal is also quite weak, and where human beings stay is full of various noises that exist in the required bandwidth of biomedical signal. The noises must be filtered by a filter to reduce the impact on the biomedical signal.
When the biomedical signal from a human body is measured, a quite large common-mode voltage follows and thus in order to measure the biomedical signal that is not distorted, a biomedical signal instrumentation amplifier of an extremely high common mode rejection ratio (CMRR) is usually required to obtain the quite weak biomedical signal from a very high AC source noise.
The biomedical signal is very easily subject to the interference of an external signal and that of a physiology signal from a person under test, so it is more difficult to measure the signal, in which internal interference comprises noises of MOS and problems of wire layout in a circuit, and external interference comprises electromagnetic waves caused by AC source and noises caused by instable power. The physiology signal as interference comprises the EOG signal, myoelectric signal, the ECG signal and the like, and thus it is important to design the instrumentation amplifier of high CMRR to restrain the common mode noises and precisely amplify the minute biomedical signal.
Generally, the instrumentation amplifier may be on the whole divided into:    (1) a voltage-based instrumentation amplifier, and    (2) a current-based instrumentation amplifier.
Most technical literatures describe the design of voltage-based instrumentation amplifier. As shown in FIG. 1, the hardware is structured with 3 voltage-based operation amplifiers and 7 resistors as passive elements. A drawback is that the high CMRR is limited to the match capability of the resistors and the resistors must occupy a large area for precise values and their match capability at the time of wire layout.
Contrarily, a standard current-based instrumentation amplifier is formed with a current conveyor, of which the matching capability is not comparatively a problem but is accomplished requiring only a small number of resistors; the required passive elements are fewer for easy control of gain. Although the common mode rejection is higher than that of a conventional voltage-based instrumentation amplifier, the number of resistors and the size of each resistor relatively impacts on thermal noise; however, the entire circuit is huge. Thus, in order to effectively solve new problems derived from power consumption, circuit performance, and noises, a new structure must be provided to find an optimal circuit.
In the design of an instrument system, an amplifier is required to block a large interference noise signal that is a signal (common-mode signal) shared by two lead wires, and amplify a weak differential signal, in which the amplifier is generally called instrumentation amplifier.
As shown in FIG. 2, a conventional instrumentation amplifier is formed with a plurality of passive elements.
For achievement of the high-performance CMRR and power supply rejection ratio (PSRR), in addition to the requirements of low output impedance and high voltage gain and the requirement of perfect impedance matching of passive elements in the circuit, the conventional voltage-based instrumentation amplifier must satisfy the area requirement for the accuracy, so this invention is to provide the new structure to reduce the passive elements and the noises and meanwhile enhance the performance of circuit.
Consequently, because of the technical defects of described above, the applicant keeps on carving unflaggingly through wholehearted experience and research to develop the present invention, which can effectively improve the defects described above.

Biomedical signal instrumentation amplifier


To provide a semiconductor memory which can drive a word line faster than a conventional art, and reduce a layout area when a chip is formed as a semiconductor integrated circuit, thereby miniaturizing the chip. In the present invention, a word driver for driving the word line is constituted by a one-stage row decoder and a one-stage word driver group, and a load on a word line select signal is reduced, thereby driving the word line at high speeds.

The present invention relates to a semiconductor memory having fast access to a built-in memory cell and particularly concerns a dynamic random access memory.
Conventionally, in a semiconductor memory having fast access to a built-in memory cell, particularly in a dynamic random access memory (hereinafter, abbreviated as DRAM), a voltage VPP is usually used as a voltage of a word line. The voltage VPP is higher than a voltage for driving a bit line or a voltage for driving a control circuit.
Such a conventional semiconductor memory will be described.
FIG. 18 is a circuit diagram showing a conventional semiconductor memory. In FIG. 18, reference numeral 1 denotes a memory array, reference numeral 2 denotes a word driver, reference numeral 3 denotes a level shifter constituting the word driver 2, reference numeral 4 denotes a first-stage driver where a high voltage VPP is supplied, reference numeral 5 denotes second-stage drivers which receive a high voltage VPP and are driven by the first-stage driver 4, reference numeral 6 denotes word lines, reference numeral 7 denotes a memory cell, reference numeral 8 denotes a sense amplifier, reference numeral 9 denotes a sense amplifier driver, reference numeral A1 denotes a first address signal, and reference numeral A2 denotes a second address signal.
The level shifter 3 level-converts the first address signal Al, the output is inputted to the first-stage driver 4, and word-line select signals WD and /WD, which are the outputs of the first-stage driver 4, are inputted to the second-stage drivers 5. The second-stage drivers 5 are driven by the second address signal A2 and the outputs are connected to the word lines 6. Further, the word line 6 is connected to the memory cell 7. The memory cell 7 is connected to the sense amplifier 8 via a bit line, and the sense amplifier 8 is connected to the sense amplifier driver 9.
In response to the output of the level shifter 3 driven by the first address signal Al, the first-stage driver 4 outputs the word line select signals WD and /WD, and the second-stage drivers 5 receiving the word-line select signals WD and /WD drives the word lines 6.
Such a conventional semiconductor memory is configured such that the word lines 6 are driven by a two-stage configuration including the first-stage driver 4 and the second-stage drivers 5. Moreover, a number of two-stage drivers 5 are connected to the word line select signals WD and /WD outputted from the first-stage driver 4, and P-channel transistors 10 and 11 connected to the word-line select signal WD are large in size. Consequently, the load of the first-stage driver 4 is large and requires a long time to drive the word lines 6.
Additionally, between the word line 6 and a power source VPP supplied to the word line 6, two stages of the P-channel transistor 12 and the P-channel transistor 11 are connected in series, and the impedance rises. Therefore, it takes a longer time to drive the word lines 6.
The present invention is achieved to solve the above conventional problem. The object of the present invention is to provide a semiconductor memory by which a word line can be driven faster than the conventional art and a layout area can be reduced so as to miniaturize a chip in case where the chip is formed as a semiconductor integrated circuit.
The semiconductor memory of the present invention, in which a memory array comprising a plurality of bit line pairs driven by a signal based on data, a plurality of word lines driven by a signal based on an address, and memory cells placed on the intersections thereof is supplied with a signal based on the data and address, the plurality of bit line pairs and the plurality of word lines are driven so that the data is written into the memory cells via the plurality of bit line pairs, the semiconductor memory comprising: a plurality of level shifters for producing a first select signal, which. vary in voltage level between a first source voltage and a ground in response to a first address signal, and are activated at a ground level to select the word lines; a plurality of word drivers for driving a selected one of the word lines in response to the first select signal; each of said word drivers comprising: a first transistor of a first conductivity type inserted between an associated word line and a power line for supplying the first source voltage; and a second transistor of a second conductivity type inserted between the associated word line and the ground. The first select signal is inputted to a gate of the first transistor via a switch controlled by a second address signal different from the first address signal, and to a gate of the second transistor.
Further, the semiconductor memory of the present invention is configured that the level shifter further produces a second select signal which a polarity opposite to the first select signal, a voltage level of the second select signal varying between the first source voltage and the ground, wherein each of the word drivers further comprises: a third transistor of the first conductivity type having source connected to the source line, a drain connected to a gate of the first transistor, and a gate connected to said associated word line; a fourth transistor of the first conductivity type having a source connected to the source line, a drain connected to the gate of the first transistor, and a gate receiving the second select signal; and a fifth transistor of the second conductivity type having a source connected to the ground, a drain connected to the associated word line, and a gate receiving a third address signal with a polarity opposite to the second address signal. The switch comprises: a sixth transistor of the second conductivity type having a source receiving the first select signal, a gate receiving the second address signal, and a drain connected to the gate of the first transistor.
According to the above configurations, when driving the word line, it is possible to reduce impedance between the word line and the first power source, thereby driving the word line at high speeds.
Moreover, the semiconductor memory of the present invention is characterized in that the third transistor of the first conductivity type has a gate width one tenth of or less than that of the first transistor of the first conductivity type.
Additionally, the semiconductor memory of the present invention is characterized in that the fourth transistor of the first conductivity type has a gate width one tenth of or less than that of the first transistor of the first conductivity type.
According to the above configurations, it is possible to switch the word drivers at high speeds, thereby driving the word line at high speeds.
Also, the semiconductor memory of the present invention is characterized by arranging the plurality of word drivers such that the word lines selected and driven by the same level shifter from the plurality of level shifters are not adjacent to each other.
According to the above configuration, the sixth transistor of the second conductivity type can be formed to be of a small size, reducing a layout area of the word drivers.
Moreover, the semiconductor memory of the present invention is characterized by supplying the first power source exclusively from the outside of the chip.
According to the above configuration, it is possible to eliminate the need for mounting an exclusive booster circuit, thereby reducing a chip area.
Furthermore, the semiconductor memory of the present invention is characterized in that the first power source is supplied by boosting a second power source with a booster circuit provided in the chip, the second power source supplying a voltage lower than that of the first power source to another circuits such as a control circuit.
Additionally, the semiconductor memory of the present invention is characterized in that the first power source is the same as a power source supplied to an I/O pad.
According to the above configurations, the number of exclusive power sources can be reduced.
As described above, the word driver for driving the word line is comprised of a one-stage row decoder and one-stage word driver group, and a load decreases on the word line select signal. Hence, the word line can be driven at high speeds.
For this reason, it is possible to drive the word line faster than the conventional art, and reduce a layout area when a chip is formed as a semiconductor integrated circuit, thereby to miniaturize the chip.

Matsushita Electric Industrial Co., Ltd.


A data distribution control apparatus controls data distribution in which distribution data having the same content are distributed to multiple wireless terminals. The data distribution control apparatus is provided with a terminal identifying unit which identifies the multiple wireless terminals to which the distribution data are distributed and a base station designating unit which designates a set of base stations selected so that one or more base stations can be connected to all of the multiple wireless terminals as the set of base stations which transmit the distribution data to the wireless terminals. The base station designating unit includes, in the set, a base station which can be connected to the multiple wireless terminals, prior to a base station which can be connected to only one wireless terminal.

Conventionally, in order to improve the communication area of wireless terminals indoors and reduce the load of macrocells, a small-sized base station called a "femtocell base station" has been introduced. Further, as a service for distributing distribution data having the same content to multiple wireless terminals, the MBMS (multimedia broadcasting services) is known. In the MBMS, a data distribution scheme called a MBSFSN (MBMS single frequency network) can be utilized, in which adjacent multiple base stations distribute data using the same frequency. According to this scheme, a frequency resource is shared among multiple base stations, therefore the efficiency of utilization of the frequency resource is improved.

Data distribution control device, data distribution system, and method of controlling data distribution


A cross-link for tracks of snow groomers, the cross-link comprising a section bar, which has an elongated shape, extends in a first direction, is limited by an outer surface and comprises a portion for fixing to at least one belt of a track of a snow groomer, and it is provided with an inner cavity, which extends through the section bar in the first direction, and is open at the side in the first direction; wherein the inner cavity is filled, at least in part, with a filling material comprising metal foam, and in certain embodiments, the inner cavity is completely filled with the filling material.

In the sector of preparing ski slopes, the manufacturing of a snow groomer is known comprising a support frame; a driver's cabin mounted centrally onto the support frame; and two tracks mounted on opposite sides of the support frame.
Each track comprises a train of wheels mounted rotatably to the support frame; a plurality of belts wound in a circle about the wheels; and a plurality of cross-links fixed to the belts transversely to an advancing direction of the track and configured to enable the grip of the track on the blanket of snow on the ski slope.
Each cross-link comprises a section bar, which is normally made of steel, aluminium or aluminium alloy, it has a contoured shape, and is limited by a substantially triangular-shaped outer surface.
The outer surface comprises a substantially flat fixing portion arranged in contact with a number of belts depending on the length of the cross-link, and two lateral sides protruding from the fixing portion and mutually converging.
The cross-link also has an inner cavity, which extends through the section bar transversely to the advancing direction of the track, and it is open laterally at the free ends thereof or transversely to one side of the cross-link.
Generally, the cross-link is fixed to the relative belts by a fixing device comprising an inner plate inserted in the inner cavity and an outer plate arranged in contact with the belts on the opposite side of the section bar.
The assembly defined by the outer plate, by the belts, by the cross-link, and by the inner plate is blocked perpendicularly to the belts by a plurality of fastening screws mounted through the outer plate, the belts, and the cross-link and screwed in the inner plate.
The snow groomer is further equipped with a plurality of operating units, such as, for example, a cutter for working the blanket of snow on the ski slopes, a blade for moving piles of snow along the ski slopes, and/or a hoist assembly for guaranteeing the stability of the snow groomer on relatively steep slopes and preventing the sliding of the snow groomer in the event of a loss of grip with the blanket of snow.
Certain known cross-links for tracks of snow groomers of the type described have some drawbacks mainly deriving from the fact that such cross-links have a relatively high number of components and are, consequently, relatively complex and costly. Furthermore, it has been proven that in normal use of snow groomers, water, also in the form of ice or snow, enters the inner cavity of the cross-link.


A regulated cascode current source has a current source circuit. A level shifter circuit is coupled to the current source circuit. The level shifter circuit has a circuit for independently controlling a voltage on a cascode node.

In many applications, the op-amp DC gain requirement is higher than what is achievable with simple single stage single stage topologies. Techniques to enhance the op-amp DC gain without going into multiple stage architecture are especially welcome in high speed circuits, where the high current levels make the transistor large.
A very widely-used method is shown in FIG. 1. In FIG. 1, the gate of the cascode transistor M2 is connected to the output of the feedback stage Al. This has two effects: 1) the resistance at the node NC is lowered by the loop gain Al and bandwidth increased, and 2) the total output conductance of the current source is lowered by the same amount. A calculation using equivalent MOSFET circuits yields a total output conductance:gout=(gds1gds2)/A1 gm2Thus, the regulation lowered the output conductance by the gain of the regulation amplifier Al and, when the current source is utilized in an operational transconductance amplifier (OTA) the DC gain is increased by the same amount.
Referring now to FIGS. 2A-2C, three different implementations of the regulation amplifier are shown. While all three regulation amplifiers work, they each have certain drawbacks. In FIG. 2A the regulation amplifier is a simple design but sets the voltage on the cascode node NC unnecessarily high. The circuit in FIG. 2B utilizes a level shifter. To set the voltage on the cascode node NC above Vdsat1, Vdsat4 needs to be higher than Vdsat1+Vdsat3. The large value of Vdsat4 degrades gm4, so as to the loop gain and bandwidth. The other implementation in FIG. 2C is a common gate amplifier. The low input impedance largely reduces the loop gain and output impedance, and makes it inferior to the circuit in FIG. 2A, although it allows the biasing of the cascade node NC to a lower voltage.
Therefore, it would be desirable to provide a regulation amplifier that overcomes the above problems. The regulation amplifier would use a wide-band wide-swing CMOS gain enhancement technique.

Wide-band wide-swing CMOS gain enhancement technique and method therefor


The present invention relates to multiple antenna wireless access points that multiplex signals by spatial division. In particular, it relates to grouping clients of the access point for spatial division multiplexing. Particular aspects of the present invention are described in the claims, specification and drawings.

The present invention relates to multiple antenna wireless access points that multiplex signals by spatial division. In particular, it relates to grouping clients of the access point for spatial division multiplexing.
Wireless LAN (WLAN) access points are a popular product category. As the number of clients that desire service from an access point increases, one strategy for increasing the number of clients served is spatial division multiplexing (SDMA). Spatial diversity involves the use of multiple antennas sufficiently well-separated at the receiver and/or the transmitter that the individual transmission paths experience effectively independent fading. Juha Heiskala and John Terry, OFDM Wireless LANs: A theoretical and Practical Guide 2002 p. 131. Some theoretical investigation has been directed to the effectiveness of spatial multiplexing, such as Helmut Bölcskei et al., "On the Capacity of OFDM-Based Spatial Multiplexing Systems", IEEE Transactions on Comm., Vol. 50, No. 2 February 2002; Helmut Bölcskei et al., "Space-Frequency Coded MIMO-OFDM with Variable Multiplexing-Diversity Tradeoff", IEEE 2003; and Arogyaswami J. Paulraj and Boon Chong Ng, "Space-Time Modems for Wireless Personal Communications", IEEE Personal Communications• February 1998. A survey of smart antenna literature has been prepared by Seshaiah Ponnekanti, "An Overview Of Smart Antenna Technology For Heterogeneous Networks", IEEE Communications Surveys, Vol. 2 no. 4, http://www.comsoc.org/pubs/surveys Fourth Quarter 1999, pp. 14 et seq.
Work on use of multiple antennas to improve wireless communications has included studies of selecting antenna subsets, utilizing a partial MIMO instead of a full MIMO. Dhananjay A. Gore and Arogyaswami J. Paulraj, "MIMO Antenna Subset Selection With Space-Time Coding", IEEE Transactions On Signal Processing, Vol. 50, No. 10, October 2002; and A. Gorokhov, D. Gore and A. Paulraj, "Performance Bounds for Antenna Selection in MIMO Systems", IEEE 2003. Use of a subset, instead of the whole set of available antennas, sacrifices antenna diversity for reduced computation and signal translation.
In general, an access point that processes signals from "m" antennas can simultaneously service m−1 clients by spatial division of signals. Theoretically, solving a linear system of differences among reception of signals at m antennas can resolve m−1 sources. The problem is more difficult than just resolving the m−1 sources, because an additional number of interference sources or interferers need to be rejected and noise needs to be filtered out.
Given the opportunity to extend the functionality of radio wireless access points by using multiple antennas and spatial division multiplexing, an opportunity arises for methods and devices that improve the performance of SDMA had a modest cost.

SDMA system using MU-SIMO for the uplink and MU-MISO for the downlink


Disclosed is a process for esterifying and/or transesterifying a polymer having a polyethylenic backbone and pendant acid and/or ester moieties comprising contacting a melt of the polymer with a transesterifying compound so that the polymer undergoes esterification and/or transesterification but not alcoholysis. The esterified or transesterified polymer also has pendant ester moieties which differ in kind and/or number from the unreacted polymer. In one embodiment, the process also comprises adding an amount of a transition metal salt that is effective to promote oxygen scavenging. Also in a further embodiment, the process comprises irradiating the transesterified polymer with actinic radiation to reduce the induction period before oxygen scavenging commences. Also disclosed are compositions comprising a component which comprises an ethylenic or polyethylenic backbone and a pendant or terminal moiety comprising a benzylic, allylic, or ether-containing radical. The invention also embodies new polyethylenic oxygen scavenging compositions comprising a transition-metal salt and the above component. Methods of making the compositions, and methods and compositions using the ethylenic or polyethylenic compositions, are disclosed.

New polymer compositions having properties that are particularly tailored for specific applications are required in response to more sophisticated purchasers of polymers. It is extremely costly and/or difficult to make these compositions directly by synthesis or via solution esterification or transesterification, but manufacturing them in mixing equipment such as an extruder has provided an economical and viable means to supply increasingly-complex polymers to specialized markets requiring them.
In one embodiment, this invention provides specialty polymers whose compositions have a polyethylenic backbone and pendant benzyl ester moieties. In another embodiment, this invention provides compositions having a polyethylenic backbone and pendant hydrocarbyl ester moieties that contain at least one allylic hydrogen. In a further embodiment, this invention provides compositions having a polyethylenic backbone and pendant hydrocarbyl moieties, especially hydrocarbyl ester moieties, wherein the hyrocarbyl group contains a heteroatom such as oxygen. In a preferred embodiment, this invention provides compositions having a polyethylenic backbone and pendant ether ester moieties, especially cyclic ether ester moieties. In certain preferred embodiments, the compositions of this invention have the following structures: ##STR1## where n is an integer from 2 to approximately 30,000; any X is individually chosen from the group consisting of hydrogen and methyl radical; and where any Y is individually chosen from the group consisting of hydrogen, alkyl radicals containing from 1 to 18 carbon atoms, alkoxy radicals having from 1 to 16 carbon atoms, alkyl ether radicals having from 2 to 18 carbon atoms, alkenyl and alkynyl radicals containing from 2 to 18 carbon atoms, alkenoxy and alkynoxy radicals having from 2 to 16 carbon atoms, alkenyl and alkynyl ether radicals having from 3 to 18 carbon atoms, amine radicals having from 1 to 16 carbon atoms, acid and metal salt of acid radicals, anhydride radicals having from 4 to 24 carbon atoms, ester and amide radicals of acids having from 1 to 16 carbon atoms, aryl radicals and substituted aryl radicals having 6 to 24 carbon atoms, aryl ether radicals and substituted aryl ether radicals having from 6 to 24 carbon atoms, and the radicals of Formula II and Formula III ##STR2## where any A is individually a heteroatom-containing radical (especially a carboxy or amido), and where any B is individually chosen from the group consisting of alkyl ether radicals having from 2 to 18 carbon atoms, alkenyl and alkynyl radicals containing from 2 to 18 carbon atoms, alkenoxy and alkynoxy radicals having from 2 to 16 carbon atoms, alkenyl and alkynyl ether radicals having from 3 to 18 carbon atoms, substituted aryl radicals having 6 to 24 carbon atoms, aryl ether radicals and substituted aryl ether radicals having from 6 to 24 carbon atoms, and the radicals of Formula IV and Formula V: ##STR3## where any R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 is individually chosen from the group consisting of hydrogen, alkyl radicals containing from 1 to 18 carbon atoms, alkoxy radicals having from 1 to 16 carbon atoms, amine radicals having from 1 to 6 carbon atoms, ester and amide radicals of acids having from 1 to 16 carbon atoms, aryl radicals and substituted aryl radicals having 6 to 24 carbon atoms, aryl ether radicals and substituted aryl ether radicals having from 6 to 24 carbon atoms, and the radicals of Formula II and Formula III; with the proviso that at least about 1 mole % of the composition comprises the radicals of Formula II and Formula III.
These specialty polymers are useful as packaging films and are also useful components for making oxygen-scavenging compositions.
This invention also provides new oxygen-scavenging compositions. It is well known that regulating the exposure of oxygen-sensitive products to oxygen maintains and enhances the quality and "shelf-life" of the product. For instance, by limiting the exposure of oxygen sensitive food products to oxygen in a packaging system, the quality or freshness of food is maintained, and the food doesn't spoil as rapidly. In addition, oxygen-scavenging packaging also keeps the product in inventory longer, thereby reducing costs incurred from waste and having to restock inventory. In the food packaging industry, several means for regulating oxygen exposure have already been developed. These means include modified atmosphere packaging (MAP) and oxygen barrier film packaging.
One method currently being used is through "active packaging", whereby the package containing the food product has been modified in some manner to regulate the food's exposure to oxygen. One form of active packaging uses oxygen-scavenging sachets which contain a composition which scavenges the oxygen through oxidation reactions. One type of sachet contains iron-based compositions which oxidize to their ferric states. Another type of sachet contains unsaturated fatty acid salts on a particulate adsorbent. See U.S. Pat. No. 4,908,151. Yet another sachet contains metal/polyamide complex. See U.S. Pat. No. 5,194,478.
However, one disadvantage of sachets is the need for additional packaging operations to add the sachet to each package. A further disadvantage arising from the iron-based sachets is that certain atmospheric conditions (e.g., high humidity, low CO.sub.2 level) in the package are sometimes required in order for scavenging to occur at an adequate rate. Further, the sachets can present a danger to consumers if accidentally ingested.
Another means for regulating exposure of a packaged product to oxygen involves incorporating an oxygen scavenger into the packaging structure itself. A more uniform scavenging effect throughout the package is achieved by incorporating the scavenging material in the package instead of adding a separate scavenger structure (e.g., a sachet) to the package. This may be especially important where there is restricted air flow inside the package. In addition, incorporating the oxygen scavenger into the package structure provides a means of intercepting and scavenging oxygen as it permeates the walls of the package (herein referred to as an "active oxygen barrier"), thereby maintaining the lowest possible oxygen level in the package.
One attempt to prepare an oxygen-scavenging wall involves the incorporation of inorganic powders and/or salts. See U.S. Pat. Nos. 5,153,038, 5,116,660, 5,143,769, and 5,089,323. However, incorporation of these powders and/or salts causes degradation of the wall's transparency and mechanical properties such as tear strength. In addition, these compounds can lead to processing difficulties, especially when fabricating thin films. The oxidation products, which can be absorbed by food in the container, typically would not have FDA approval for human consumption.
EP 0 519 616 discloses an oxygen-scavenging composition comprising a blend of a first polymeric component comprising a polyolefin, the first polymeric component having been grafted with an unsaturated carboxylic anhydride or an unsaturated carboxylic acid, or combinations thereof, or with an epoxide; a second polymeric component having OH, SH, or NHR.sup.2 groups where R.sup.2 is H, C.sub.1 -C.sub.3 alky, substituted C.sub.1 -C.sub.3 alkyl; and a metal salt capable of catalyzing the reaction between oxygen and the second polymeric component, the polyolefin being present in an amount sufficient so that the blend is non phase-separated. A blend of polymers is utilized to obtain oxygen scavenging, and the second polymeric component is preferably a polyamide or a copolyamide such as the copolymer of m-xylylene-diamine and adipic acid (MXD6).
The oxygen scavenging systems disclosed in U.S. Pat. Nos. 5,021,515, 5,194,478, and 5,159,005, European Publication EP 0 380 319 as well as PCT Publication Nos. 90/00504 and 90/00578 illustrate attempts to produce an oxygen-scavenging wall. These patent applications disclose incorporating a metal catalyst-polyamide oxygen scavenging system into the package wall. Through catalyzed oxidation of the polyamide, the package wall regulates the amount of oxygen which reaches the interior volume of the package (active oxygen barrier) and has been reported to have oxygen scavenging rate capabilities up to about 5 cubic centimeters (cc) oxygen per square meter per day at ambient conditions. However, this system suffers from significant disadvantages.
One particularly limiting disadvantage of polyamide/catalyst materials can be a low oxygen scavenging rate. U.S. Pat. No. 5,021,515, Example 7, illustrates that adding these materials to a high-barrier package containing air produces a package which is not generally suitable for creating an internal oxygen level of less than 0.1% (starting with air) within a period of four weeks or less at room temperature, as is typically required for headspace oxygen scavenging applications.
There are also disadvantages to having the oxygen-scavenging groups in the backbone or network structure in this type of polyamide polymer. The basic polymer structure degrades rapidly and is quickly weakened upon reaction with oxygen. This can adversely affect physical properties such as tensile or impact strength of the polymer. The degradation of the backbone or network of the polymer can increase the permeability of the polymer to those materials sought to be excluded, such as oxygen.
Moreover, polyamides such as MXD6 are typically incompatible with thermoplastic polymers used in flexible packaging walls, such as ethylene-vinyl acetate copolymers and low density polyethylene. Even further, when many polyamides are used by themselves to make a flexible package wall, they may result in inappropriately stiff structures. Many polyamides also incur processing difficulties and higher costs when compared with the costs of thermoplastic polymers typically used to make flexible packaging. Even further, they are sometimes difficult to heat seal. Thus, all of these are factors to consider when selecting materials for packages, especially flexible packages and when selecting systems for reducing oxygen exposure of packaged products.
Another approach to scavenging oxygen is disclosed in EP 0 507 207, which discloses an oxygen-scavenging composition comprising an ethylenically unsaturated hydrocarbon and a transition metal catalyst. This patent states that ethylenically unsaturated compounds such as squalene, dehydrated castor oil, and 1,2-polybutadiene are useful oxygen scavenging compositions, and ethylenically saturated compounds such as polyethylene and ethylene copolymers are used as diluents. Compositions utilizing squalene, castor oil, or other such unsaturated hydrocarbon typically have an oily texture, which is undesirable for applications such as wrapping meat for sale in retail grocery stores. Further, polymer chains which are ethylenically unsaturated would be expected to either cross-link to become brittle or to degrade upon scavenging oxygen, weakening the polymer due to polymer backbone breakage.
U.S. Pat. Nos. 4,717,759, 4,994,539, and 4,736,007, which are incorporated by reference in their entirety, disclose ethylene copolymers which comprise 85.0 to 99.995 mol % of an ethylene unit, 0.005 to 5 mol % of a comonomer unit represented by Formula (VI) ##STR4## wherein Ar is ##STR5## R.sub.1 is a hydrogen atom or a methyl group, each of R.sub.2 and R.sub.3 is a hydrogen atom, a chlorine atom or a straight-chain or a side-chain alkyl group having 1 to 4 carbon atoms, and 0 to 10 mol % of an ethylenic unsaturated monomer unit, the ethylene copolymer having a density of 0.860 to 0.970 g/cm.sup.3 and a melt index of 0.05 to 100 g/10 minutes. The patent states that copolymers may be produced using either a Ziegler catalyst or through polymerization catalyzed by free radicals. These polymers are limited to having less than 5 mol % of the comonomer unit and are useful for electrical insulation. Although these polymers may be used to make oxygen-scavenging compositions, these polymers do not themselves scavenge oxygen.
What has been needed is an oxygen-scavenging polymer composition that is easily processed, especially into thin film, and that does not suffer rapid polymer backbone oxidation as the composition scavenges oxygen. This invention supplies compositions overcoming these problems.
The oxygen-scavenging compositions of this invention comprise a transition-metal salt and a compound having an ethylenic or polyethylenic backbone and having pendant or terminal moieties which contain a carbon atom that can form a free radical that is resonance-stabilized by an adjacent group. Thus, a carbon atom having a hydrogen atom adjacent to a phenyl radical, an ethylenically-unsaturated carbon atom, or a heteroatom such as oxygen can form a free radical that is resonance-stabilized by the adjacent double bond, phenyl ring, or oxygen, respectively.
In one embodiment, the invention provides a composition comprising a transition-metal salt and a component having the structure of Formula (I) above. The invention also provides new compositions comprising a transition-metal salt and a polymer which comprises a polyethylenic backbone and a pendant moiety comprising a benzyl radical having at least one hydrogen atom on the methylene group of the benzyl radical, and/or an allylic radical and/or an ether radical that individually contain at least one hydrogen atom alpha to these radicals.
In another embodiment, the invention provides a composition comprising a transition-metal salt and a polymer, where said polymer comprises 1) a polyethylenic backbone, and 2) pendant moieties which have at least one radical selected from the group consisting of a) benzyl ester radicals, b) N-benzyl-amide radicals, c) N-benzylimide radicals, d) benzyl-thio radicals, e) benzyl ketone radicals, f) benzyl-ether radicals, g) aryl radicals and substituted aryl radicals having 6 to 30 carbon atoms, h) aryl ether radicals and substituted aryl ether radicals having from 6 to 30 carbon atoms, and i) benzyl radicals which have the phenyl radical of said benzyl radical chemically bonded to at least one member selected from the group consisting of imide radicals which are N-substituted with said benzyl radicals, benzyl-ketone radicals, alkyl radicals containing from 1 to 18 carbon atoms, alkoxy radicals having from 1 to 16 carbon atoms, amine radicals having from 1 to 6 carbon atoms, ester and amide radicals of acids, said ester and amide radicals having from 1 to 16 carbon atoms, aryl radicals and substituted aryl radicals having 6 to 24 carbon atoms, and aryl ether radicals and substituted aryl ether radicals having from 6 to 24 carbon atoms.
In another embodiment, the invention provides a composition comprising a transition-metal salt and an ethylenic or polyethylenic backbone having a pendant or terminal benzyl radical, wherein the composition, upon reaction with molecular oxygen, produces benzoic acid or a benzoic acid substituted with at least one radical selected from the group consisting of alkyl radicals containing from 1 to 18 carbon atoms, alkoxy radicals having from 1 to 16 carbon atoms, amine radicals having from 1 to 6 carbon atoms, ester and amide radicals of acids having from 1 to 16 carbon atoms, aryl radicals and substituted aryl radicals having 6 to 24 carbon atoms, and aryl ether radicals and substituted aryl ether radicals having from 6 to 24 carbon atoms.
The invention also provides a composition comprising an ethylenic or polyethylenic backbone and moieties which contain a radical having an allylic hydrogen and which are pendant or terminal to the ethylenic or polyethylenic backbone. The radical containing allylic hydrogen may be cyclic, linear, or branched, and may be unsubstituted or substituted with alkyl, aryl, or heteroatom-containing radicals, for example.
The invention also provides a composition comprising an ethylenic or polyethylenic backbone and hydrocarbyl moieties which contain at least one hydrogen alpha to an ether radical and which are pendant or terminal to the ethylenic or polyethylenic backbone. The moiety containing ether may be cyclic, linear, or branched, and may be unsubstituted or substituted with alkyl, aryl, or other radicals containing a heteroatom, for example.
Among other factors, the present invention is based on our finding that compositions as described herein are highly effective oxygen scavengers in terms of rate of oxygen scavenging and/or oxygen scavenging capacity, particularly where the compositions contain a heteroatom-containing radical such as a carboxy or amido group directly bonded to a benzyl radical, an allylic radical, or an ether radical. In many instances, these compositions have excellent physical and processing properties which permit their incorporation into a wide range of packaging applications. We have found that, typically, films of these compositions are easily made using conventional techniques. The compositions are usually compatible with many common thermoplastic materials used in packaging, particularly polyethylene and copolymers of ethylene and alkyl acrylates or methacrylates.
Furthermore, many of the compositions of the present invention have been found to have surprisingly reduced induction periods in scavenging oxygen upon exposure to ultraviolet (UV) radiation without the need for added photo-initiators.
This invention also provides a process for making polymers, some of which are useful in making oxygen scavenging compositions. Transesterification of a polymer can produce a number of different polymers. For example, M. Lambla et al., 27 Polymer Sci. and Eng'g, No. 16 (mid-Sept. 1987) 1221-28, discuss the transesterification of ethylene vinyl acetate copolymer with an alcohol in an extruder and in the presence of a tin catalyst to form ethylene vinyl alcohol copolymer, which has a polyethylenic backbone and pendant alcohol moieties. Also, D. Seebach et al., Synthesis (Feb. 1982) 138-41, discuss transesterification of an ester with an alcohol in solution using a titanium catalyst. The reactions require from 3 to 120 hours.
U.S. Pat. No. 4,767,820 to M. Keogh discloses compositions useful as extrudates about wires and cables which comprise hydrolyzable pendant silane moieties and tetramethyl titanate dispersed in a normally solid alkylene-alkyl acrylate copolymer matrix. Transalkylation of the silane and alkyl acrylate moieties results in a cross-linked product.
Not all transesterification reactions are useful. U.S. Pat. No. 5,023,284 to M. Cheung et al. notes that transesterification occurs during melt-blending of two polyesters due to the presence of residual titanium catalyst and causes embrittlement and other deleterious effects.
What has been missing in the prior art is an economical process for controlling the esterification and/or transesterification of a polymer having a polyethylenic backbone and pendant acid and/or ester moieties to produce a polymer having a polyethylenic backbone and pendant ester moieties that differ in number and/or type from the unreacted polymer. In one embodiment, this invention provides an economical process for esterifying or transesterifying a polymer comprising forming a melt of a polymer having a polyethylenic backbone and pendant acid or ester moieties, and contacting the melt in suitable mixing equipment (for example, an extruder) under esterification or transesterification conditions with a compound capable of esterifying or transesterifying the acid or ester moieties, where the polymer undergoes esterification and/or transesterification but not alcoholysis, and the polymer after esterification and/or transesterification has a polyethylenic backbone and pendant ester moieties.
The process may further comprise adding an amount of transition metal salt into a melt of selected esterified or transesterified polymers made in the above process in an amount effective to promote oxygen scavenging by the esterified or transesterified polymer. In one preferred embodiment, an ethylene alkyl acrylate copolymer is transesterified in an extruder to form an ethylene hydrocarbyl acrylate copolymer. In another preferred embodiment of the process, a cobalt salt is added to the transesterified polymer to make an effective oxygen scavenger. In a third preferred embodiment, the processed polymer is exposed to actinic radiation.
Among other factors, it has been discovered that a melt of a polymer having pendant acid and/or ester moieties can be esterified and/or transesterified with a compound capable of esterifying or transesterifying the acid and/or ester moieties by blending the melt and the compound in suitable polymer mixing equipment under esterification and/or transesterification conditions, thereby producing a polymer having pendant ester moieties which differ in number and/or type from the unreacted polymer. This process provides fast reaction times and accurate control over the extent of esterification and/or transesterification, thereby providing an economical means to produce polymers having properties tailored to specific applications. The process also provides a means to make highly-effective oxygen scavenging compositions.
This invention also provides compositions that can be made by the process of esterifying or transesterifying a melt of a polymer having an ethylenic or polyethylenic backbone. The above-mentioned advantages and others are further described below.

Compositions having ethylenic backbone and benzylic, allylic, or ether-containing side-chains, oxygen scavenging compositions containing same, and process for making these compositions by esterification or transesterification of a polymer melt


A curb assembly is provided for mounting on a sloped, standing seam metallic roof, in order to provide support for a roof fixture, such as an exhaust fan or skylight. The curb assembly includes a box-like structure mounted atop the roof in surrounding relationship to a roof opening. The curb assembly further includes an underlying, below-roof frame assembly. Specialized upper and lower end connection structure serves to securely mount the curb assembly to the metal roof.

1. Field of the Invention
The present invention is broadly concerned with improved, prefabricated curb assemblies designed to be mounted on standing seam roofs (which are traditionally formed of metal). More particularly, the invention pertains to the curb assemblies and overall roof constructions with curb assemblies mounted thereon. The curb assemblies are specially designed for rapid and easy field installation, while providing a rigid, water-tight, peripherally sealed construction.
2. Description of the Prior Art
Roof curb assemblies have been in use for many years for the purpose of mounting roof fixtures, such as exhaust fans, skylights, or air conditioning components. Generally speaking, these curb assemblies include upstanding box walls, which are secured to the underlying roof and in surrounding relationship to an opening formed in the roof and associated with the mounted fixture. In some instances, roof curb assemblies are of modular design and are constructed on site, see, e.g., U.S. Pat. No. 7,065,928. In other instances, prefabricated roof curb assemblies have been provided, which require no field assembly.
In many industrial applications, standing seam sloped metal roofs are deemed optimum. These roofs are made up of a series of elongated, side-by-side, interconnected panels and present a higher end and a lower end for water drainage. In the construction of these roofs, the panels are first placed in adjacency with the elongated side marginal standing seam components in close proximity. Thereupon, a seaming device is used to form laps or other types of joints by appropriate joining of the seam components. These joints can take a number of forms, e.g., simple overlaps, single or double locks, tees, snap locks, battens, or trapezoidal laps, see, e.g., http://www.nrca.net/roofing/Metal-roof-systems-for-steep-slope-applications-901.
Curb assemblies for standing seam metal roofs must be specially configured in order to accommodate the standing seams, because in many instances, the necessary roof openings have a lateral dimension which crosses one or more of the seams. Moreover, the curb assemblies must be easily installed in the field and designed eliminate or minimize leakage around the assemblies.


Systems and methods are described for measuring flow properties of a high gas-cut multiphase mixture flowing in a conduit, such as a wet-gas produced from a hydrocarbon well. In aspects of the present invention, one or more receivers are used to receive Doppler shifted signals resulting from an interaction between a propagating dominant microwave mode developed in the conduit and the high gas-cut multiphase mixture flowing in the conduit. Analysis of the Doppler shift in the received signals may provide for determining the velocity of the gas and/or the liquid phase of the high gas-cut multiphase mixture. In other aspects, analysis of the phase difference of Doppler signals received at the plurality of receivers provides for a determination of the content of the wet-gas, such as the water holdup.

In the hydrocarbon industry, it is common for a multiphase mixture comprising a gas phase and a liquid phase to be produced from a wellbore and/or to be transported through pipelines during or after production. In general, the gas phase may comprise gaseous hydrocarbons and the liquid phase may comprise oil and water. Furthermore, it is often important in the hydrocarbon industry to measure the flow properties of the components of the multiphase mixtures, including making measurements regarding the amount of the gaseous hydrocarbons in the multiphase mixture, the amount of the liquid hydrocarbons and/or water in the multiphase mixture and/or to measure the velocity of the gaseous hydrocarbons, liquid hydrocarbons and/or water in the multiphase mixture so that flow rates for the phases or components of the phases may be determined.
With the growing importance of natural gas, there exists a need in the hydrocarbon industry for an accurate determination of gas and liquid (oil and water) flow rates for wet-gas flows. Wet gas flows may be considered to comprise multiphase mixtures with a gas-volume-fraction ("GVF") or gas-cut greater than 90% or more particularly a GVF beyond 95%. Often a wet gas flow, as is often encountered in gas condensate systems, may comprise an extremely high amount of gas, i.e., the wet gas flow may have a gas cut that is 90% or may be greater than 99%. Generally, making accurate measurements of a wet-gas flow using a single-phase gas flowmeter may be difficult. Moreover, existing commercial multiphase flowmeters may deliver good performance at gas-cuts below around 95%, but may not perform well for higher gas-cut percentages. As such, to increase the gas-cut range of the multiphase flowmeter beyond 95%, some multiphase flowmeters use complicated procedures such as partial gas separation and/or flow diversion devices.


A system and method for concurrent investigations of static data stored in one or more secondary storage devices of one or more target machines in a data communications network. The network includes an examining machine, a secure server, and various target machines. The examining machine transmits to the target machines a search request including a search key. The examining machine also streams to each target machine metadata information and file extents of the files to be searched. The target machines concurrently search the indicated file extents for the search key. The target machines then stream the search results to the examining machine.

U.S. Pat. No. 6,792,545, assigned to the Assignee of the present application, discloses a system and method for performing secure investigations of networked devices over a computer network. Part of such investigation entails the searching of one or more secondary storage devices for specific patterns or data. According to one prior art mechanism, an examining machine downloads the data to be searched from the networked devices and searches the data for specific patterns locally at the examining machine. Clearly, such a mechanism wastes bandwidth and resources of the examining machine.
Accordingly, what is desired is a system and method in a computer investigations system for efficiently searching secondary storage devices for specific data patterns during an online investigation of those devices.

System and method for searching for static data in a computer investigation system


The present invention provides a data recovery method in a system with storage of default values and prior configuration values, including executing initialization of the system; loading the default values; detecting a status of a first flag to generate a first detection result; and, determining whether a boot-up sequence is complete according to the first detection result.

Conventionally, non-volatile memory (NVM) 100, such as flash memory, of a system is provided with four blocks (hereinafter referred to as first block 110, second block 120, third block 130 and fourth block 140, respectively), which are used respectively to store a default value 110a, a current configuration value 120a, a prior configuration value 130a, and a default-recovery value for 140a.
Referring to FIG. 1A, during an initialization sequence, the default value 110a in the first block 110 of the non-volatile memory 100 is loaded into volatile memory 200, such as DDR (double data rate) memory by a memory control unit.
Referring to FIG. 1B, the configuration value executed during a previous shutdown and recorded in the third block 130 (hereinafter referred to as the prior configuration value 130a) is then loaded into the volatile memory 200, and the default value 110a is modified according to the prior configuration value 130a. Thereby, the system can rapidly access the volatile memory 200.
Referring to FIG. 1C, during an operation of the system, the currently executing configuration value (hereinafter referred to as the current configuration value 120a) is stored into the second block 120 of the non-volatile memory 100 by means of mapping the current configuration value 120a into the second block 120 of the non-volatile memory 100 to reserve the data being executed. Referring to FIG. 1D, the configuration value executed during shutdown is stored in the third block 130 of the non-volatile memory 100 as the prior configuration value 130a. Thus, in the next boot-up sequence, the same configuration values can be executed by loading the prior configuration value 130a.
Referring to FIG. 1E, when a default-value recovery is executed, the system will read the default-recovery value 140a stored in the fourth block 140 of the non-volatile memory 100, and write it into the volatile memory 200.
The conventional system data management structure needs two spaces to store the default value for initialization and the default value for recovery. However, conservation of memory and storage space has become a very important issue.


At least two input signals, each characterizing a radio signal having a radio frequency (RF), are received. The input signals are converted into at least three output signals. The output signals have a unique combination of corresponding magnitudes for each RF phase difference between the input signals. A set of magnitudes corresponding to the output signals is measured using a mobile measuring device. An RF phase angle value is determined based the measured set of magnitudes. The RF phase angle value is converted into an angle value indicative of the direction of arrival of the radio signal.

One known method to build a radio signal direction-finding system includes creating a single antenna with a narrow beamwidth. When the signal received by the antenna is relatively strong, then the radio source is known to be in the direction the antenna's beam is pointed to. A narrow beam is necessary to obtain the source's direction with good angular resolution. It is noted that an antenna's beamwidth is inversely related to its size. An antenna with a sufficiently narrow beam tends to be inconveniently large.
Another known method of determining the direction of arrival of a radio signal is a sequential lobing technique. In the sequential lobing technique, an antenna system is deployed which has two beams (also known as lobes) pointing in two different but nearby directions. This technique typically involves activation of the two beams alternately and sequentially on sequential radio transmissions or radar pulses. The signal strengths from the two beams can be compared to each other. In the sequential lobing technique, the source of the radio signal is deduced to be in the direction of the stronger beam and the ratio of the strengths indicates the degree the radio signal is directed toward the stronger beam. The sequential lobing technique does not require especially narrow beam widths and thus the antenna(s) can be relatively small.
However, transmitter instability, changing multipath and other variations can cause the received signal strength to change from the activation of one beam to the other for reasons unrelated to direction of arrival. A radio signal direction-finding system based on the sequential lobing technique may misinterpret these changes as the direction of arrival indication.

Direction of arrival determination for a radio signal


A dispersion compensator (10) that compensates dispersion occurring in an optical pulse includes a spatial filter (100) from which a pulsed light having a single peak is emitted as an autocorrelation light when a light having a strong correlation with an optical pulse to be dispersion-compensated is introduced into the spatial filter, and from which a scattered light is emitted as a cross-correlation light when a light having a weak correlation with an optical pulse to be dispersion-compensated is introduced into the spatial filter, wherein the dispersion compensator compensates dispersion occurring in the optical pulse having the strong correlation with the optical pulse to be dispersion-compensated, with the autocorrelation light treated as a dispersion-compensated optical pulse.

In recent years, with the advent of the advanced information society, optical communication networks in which optical fibers are used for transmission lines have been gradually developed. In the optical communication networks, using short optical pulses that can be superimposed enables a large volume of data to be transmitted at high speed. Further, the shorter a temporal length of an optical pulse becomes, the more it becomes possible to transmit the large volume of data at high speed.
It is to be noted that velocities of lights slightly differ from one another in a medium such as an optical fiber, depending on wavelengths, and wavelength dispersion, to be precise, group velocity dispersion occurs. That is to say, the shorter a temporal length of an optical pulse becomes, the more easily dispersion occurs in a wavelength, thereby restricting a transmission rate and a transmission distance to impede high-speed communication.
For this reason, in the optical communication networks where data are transmitted by controlling lights in a femtosecond time domain (10−15 to 10−12 seconds), a dispersion compensator is imperative for compensating dispersion such as spread of or variation in a pulse width.
With this, for instance, dispersion compensators each using a chirped fiber grating (e.g., refer to Patent Reference 1) have been proposed.
Patent Reference 1: Japanese Unexamined Patent Application Publication No. 2000-137197

Dispersion compensator, and dispersion compensating method