A reciprocating piston compressor having a suction muffler and a pair of discharge mufflers to attenuate noise created by the primary pumping frequency in the primary pumping pulse. The suction muffler is disposed along a suction tube extending between the motor cap and the cylinder head of the compressor. The discharge mufflers are positioned in series within the compressor to receive discharge gases from the compression mechanism and are spaced one quarter of a wavelength from each other so as to sequentially diminish the problematic or noisy frequencies created during compressor operation. The motor/compressor assembly including the motor and compression mechanism is mounted to the interior surface of the compressor housing by spring mounts. These mounted are secured to the housing to define the position of the nodes and anti-nodes of the frequency created in the housing to reduce noise produced by natural frequencies during compressor operation.

The present invention relates to reciprocating piston fluid compression devices such as hermetic refrigerant compressors, particularly with regard to quieting same.
Fluid compression devices such as, for example, refrigerant compressors, receive a gas at a suction pressure and compress it to a relatively higher, discharge pressure. Depending on the type of compression device, the work exerted on the gas in compressing it is characterized by a series of intermittently exerted forces on the gas, the magnitude of these forces normally varying from zero to some maximum value. For example, in a cylinder of a reciprocating piston type compressor, this force ranges from zero at the piston's bottom dead center (BDC) position, to a maximum at or near the piston's top dead center (TDC) position, at which the pressure of the compressed gas is respectively at a minimum pressure (i.e., substantially suction pressure) and a maximum pressure (i.e., substantially discharge pressure). Some quantity of the gas is discharged from the cylinder as the piston assumes new positions as it advances from BDC to TDC, and thus the compressed gas flowing from the cylinder is not at a uniform pressure. Rather, the gas which flows from the cylinder, which is generally referred to as being at discharge pressure, actually has many different pressures.
Pulses of higher discharge pressure result in the compressed gas flowing from the cylinder, these pulses being in the portion of the flowing gas which leaves the cylinder as the piston approaches or reaches TDC. As the piston cycles in its cylinder, regular, equally distributed patterns of these pulses are created in the compressed gas which flows through a conduit, tube or line leading from the compression mechanism. The pulsating flow of compressed gas through this discharge line may be represented by sine waves of various frequencies and having amplitudes which may vary with changes in the quality of the refrigerant; these changes are effected by changes in refrigerant type, temperature or pressure. Pulsations at certain frequencies may be more noticeable, and thus more objectionable, than others.
Further, the nominal discharge pressure, i.e., the pressure at which the compressed gas is generally considered to be, will also vary with refrigerant quality. The frequency of these high pressure pulses in the compressed gas flowing through the discharge line, however, has a substantially constant frequency which directly correlates to the speed at which the gas is compressed in the cylinder, and the number of cylinders in operation. This frequency is referred to as the primary pumping frequency, and is generally the lowest frequency exhibited by the pressure pulsations in the compressed gas.
The amplitude of the pressure pulses at the primary pumping frequency tend to be the largest in the compressed gas flow. Because the primary pumping pulses are at low frequencies and large amplitudes, they are often the primary cause of objectionable noise or vibration characteristics in compressors or the refrigeration systems into which these compressors are incorporated. These systems normally also include at least two heat exchangers, a refrigerant expansion device, and associated refrigerant lines which link these components into a closed loop relationship. Pressure pulsations at other, higher frequencies have amplitudes which are relatively smaller, but certain of these pressure pulsations may also be objectionable. Further, some objectionable pressure pulsations may establish themselves in the conduits or lines which convey refrigerant substantially at suction pressure to the compression mechanism.
Substantial effort has been expended in attempting to quiet these pressure pulses in addressing noise or vibration concerns, and it is known to provide mufflers in the discharge or suction lines to help resolve these issues. These mufflers may be of the expansion chamber type, in which a first refrigerant line portion opens directly into a chamber, wherein the amplitude and/or frequency of at least one of the pulses may be altered, and from which the refrigerant exits through a second line portion. Further, it is known that the discharge chamber in the head of a reciprocating piston compressor can also serve as a type of expansion chamber muffler. An expansion chamber type muffler of any type is not entirely satisfactory, however, for it may cause a substantial pressure drop in the gas as it flows therethrough, resulting in compressor inefficiency. Further, such mufflers may not provide sufficient attenuation required by the application.
An alternative to an expansion chamber type of muffler is what is well known in the art as a Helmholtz resonator type of muffler wherein the wall of a portion of the discharge pressure line may be provided with a plurality of holes, that portion of the discharge line is sealably connected to a shell which defines a resonance chamber, the holes in the discharge line providing fluid communication between the interior of the discharge line and the resonance chamber. The size and/or quantity and/or axial spacing of these holes, and the volume of the resonance chamber, are variably sized to tune a Helmholtz resonator to a particular frequency, and the amplitude of pulses at that frequency are thereby attenuated. Compared to an expansion chamber type of muffler, a Helmholtz muffler provides the advantage of not causing so significant a pressure drop in the fluid flowing therethrough; thus compressor efficiency is not compromised to the same degree.
Although a Helmholtz resonator may be effective for attenuating the amplitude of fluid pulses having shorter wavelengths, in which case the resonator extends axially over at least a substantial portion of the pulse wavelength, prior Helmholtz resonator arrangements may not be effective for attenuating the amplitude of fluid pulses having longer wave lengths. As mentioned above, the primary pumping frequency tends to be rather low, the primary pumping pulses cyclically distributed over a rather long wavelength. By way of the example of a single-speed hermetic reciprocating piston type compressor, the motor thereof rotates at a speed which is directly correlated to the frequency of the alternating current (AC) electrical power which drives it. In the United States, AC power is provided at 60 cycles/second. The electrical current is directed through the windings of the motor stator, and electromagnetically imparts rotation to the rotor disposed inside the stator. The crankshaft of the compressor is rotatably fixed to the rotor and drives the reciprocating piston, which compresses the refrigerant. Thus the primary pumping frequency is at or near 60 cycles per second. The speed of sound in refrigerant gas at the discharge temperature and pressure of this example is 7200 inches per second. Thus, in accordance with the equation:c/f=λ  (1)where speed "c" is 7200 inches per second and frequency "f" is 60 cycles per second, for the above example wavelength "λ" of the primary pumping pulse is 120 inches. Notably, should the compressor be of the two cylinder variety, twice as many primary pumping pulses will be issued per revolution of the crankshaft; thus λ will then be 60 inches. It can be readily understood by those of ordinary skill in the art that simply providing a single Helmholtz resonator in the discharge line may be largely ineffective for attenuating the amplitude of a pulse which has such a long wavelength, for the point(s) of maximum pulse amplitude, which ought to be coincident with the resonator, may be too far separated. In order for a single Helmholtz resonator to quiet a pulse having such a long wavelength, the resonator would be far too long to facilitate easy packaging within the refrigerant system, let alone within the hermetic compressor housing.
What is needed is a noise attenuation system for a compression device which effectively addresses the noise and vibration issues associated with pressure pulses of relatively long wavelength, such as primary pumping pressure pulses, and which overcomes the above-mentioned limitations of previous muffler arrangements.
Typically, reciprocating piston compressors include a cylinder block having at least one cylinder bore in which is disposed a reciprocating piston. The piston is operatively coupled, normally through a connecting rod, to the eccentric portion of a rotating crankshaft. Rotation of the crankshaft, which may be operatively coupled to the rotor of an electric motor, induces reciprocation of the piston within the cylinder bore.
Covering an end of the cylinder bore, in abutting contact with the cylinder block directly or through a thin gasket member disposed therebetween, and in facing relation to the piston face, is a valve plate provided with suction and discharge ports which are both in fluid communication with the cylinder bore. Each of the suction and discharge ports are provided with a check valve through which gases are respectively drawn into and expelled from the cylinder bore by the reciprocating piston as the piston respectively retreats from or advances toward the valve plate.
The suction and discharge check valves are normally located adjacent and abut opposite planar sides of the valve plate and may, for example, be of a reed or leaf type which elastically deform under the influence of the gas pressure which acts thereon as the gas enters or leaves the cylinder bore through suction and discharge ports provided in the valve plate, and which are covered by the respective valves. The cylinder head is disposed on the side of the valve plate opposite that which faces the cylinder block, and in prior art compressors the head is in abutting contact with the valve plate, directly or perhaps through a thin gasket member disposed therebetween. Alternatively, the valve plate-interfacing surface of the head may be provided with a machined groove in which a seal is disposed, the seal compressed as the head is abutted to the interfacing valve plate surface.
The cylinder head is normally a die cast aluminum or cast iron component which at least partially defines separate suction and discharge chambers therein. Suction pressure gas is introduced into the head suction chamber through an inlet to the head; and the suction pressure gas is drawn by the retreating piston from the head suction chamber through the suction port of the valve plate, past the suction check valve, and into the cylinder bore, where the gas is compressed to substantially discharge pressure. The discharge check valve prevents gas in the discharge chamber from being drawn into the cylinder bore through the discharge port of the valve plate.
Discharge pressure gas in the cylinder bore is expelled through the discharge port of the valve plate, past the discharge check valve, and into the discharge chamber of the head, from which it is expelled through the outlet of the head. The suction check valve prevents gas in the cylinder bore from being expelled into the suction chamber of the head through the suction port of the valve plate. As noted above, the discharge chamber defined by the head of a reciprocating piston compressor may serve as a type of expansion chamber muffler. Enlarging the volume of this chamber by including such a spacer generally improves the head's ability to perform as an expansion type discharge muffler and better attenuate noise associated with pulses carried by the compressed gas.
Moreover, a problem experienced with some reciprocating compressors, particularly those in which the discharge gas is conveyed directly from the head discharge chamber through interconnected conduits to a heat exchanger, is that discharge pressure gas within the head discharge chamber does not readily exit the head, resulting in a pressure buildup in the head discharge chamber during compressor operation. Consequently, the cylinder bore may not be fully exhausted of discharge pressure gas at the end of the compression cycle because the buildup of gas within the head discharge chamber inhibits the accommodation therein of gas being exhausted thereinto from the cylinder. Because gas from the previous compression cycle has not been fully exhausted from the cylinder bore, less suction pressure gas can be drawn into the cylinder during the next compression cycle. Thus, the efficiency of the compressor is compromised. Moreover, the temperature of gas on the discharge side of the system, both within the head itself and the high side of the system, may become excessively high as more and more work is expended on the gas already at discharge pressure.
The previously preferred solution to this problem has been to enlarge the size of the head discharge chamber, thereby allowing gas which is exhausted from the cylinder bore to be more easily compressed into, and accommodated by, the head discharge chamber. As noted above, enlargement of this chamber usually also facilitates improvements in noise quality. One approach to enlarging the head's discharge chamber has been to retool the head. This solution carries with it attendant tooling costs which may not be insubstantial. Further, where a common head design is shared between different compressor models, a newly designed head which solves the problem for one model may not meet the needs (e.g., packaging requirements) of the other model(s), thereby requiring a plurality of head designs to be released and maintained in inventory.
Another approach to enlarging the head's discharge chamber is to provide a spacer between the valve plate and the existing head, which effectively enlarges the volume of the head discharge chamber (and the suction chamber as well). The spacer comprises a separate component which may be used in one compressor but not another, the two compressor models sharing a common head design. These spacers may be made of plastic or metal.
Previous plastic spacers have had coefficients of thermal expansion which differ substantially from those of the cylinder block and/or the head, and consequently may either shrink and thereby cause a leak across its sealing surfaces, or expand and be overly compressed between the valve plate and head, thereby placing considerable additional stress on the spacer, the head and bolts which extend through the spacer and attach the head and spacer to the cylinder block. If so stressed, the spacer may crack and consequently leak. Plastic spacers do, however, provide the benefits of being lightweight, and providing insulation against thermal conduction between the head and the cylinder block, thereby keeping the discharge gas somewhat cooler and thus reducing the capacity required of the heat exchanger which condenses the high pressure gas to a high pressure liquid. Plastic spacers are also made inexpensively by injection molding techniques.
Previous metal spacers, on the other hand, undesirably promote thermal conduction between the head and the cylinder block, weigh more, and usually are die cast and machined, resulting in a relatively more expensive part vis-a-vis a plastic spacer. A metal spacer, however, may have a coefficient of thermal expansion which avoids the above mentioned shrinkage and stress concerns attendant with plastic spacers. Further, prior plastic and metal spacers alike may require additional, separate gaskets to seal the opposite open spacer ends to the valve plate and head in order to provide a proper seal.
What is needed is an inexpensively produced head spacer for increasing the volume of the discharge chamber of the cylinder head, which provides seals between the head spacer and the valve plate, and between the head spacer and the cylinder head, without the need for additional seals.
Further, it is known to dispose an end cap over the end of the annular motor stator in a low-side hermetic compressor, the end cap covering both the stator end and the end of the motor rotor disposed inside the stator. It is also known to drawn suction pressure refrigerant gas from within the end cap through a suction tube extending therefrom which is in fluid communication with the inlet to a compression mechanism driven by the motor and disposed at the opposite end of the motor stator. Such a configuration is shown, for example, in U.S. Pat. No. 5,129,793 (Blass et al.) and U.S. Pat. No. 5,341,654 (Hewette et al.), and exemplified by the Model AV reciprocating compressors manufactured by the Tecumseh Products Company of Tecumseh, Michigan. It is also known to provide suction mufflers in this tube intermediate the stator end cap and the compression mechanism, as taught by Blass et al. '793 and Hewette et al. '654.
A problem with such suction tube arrangements is that their lengths are fixed and particular to stators of a given height. A unique suction tube design must be provided for each different stator height in compressor assemblies which might otherwise be similar, resulting in part complexities and associated inventorying costs and efforts, and additional jigs and fixtures to produce different suction tube assemblies to accommodate these various stators. It would be desirably to provide a single suction tube assembly, with or without a muffler provided therein, which extends between the stator end cap and the inlet to the compression mechanism and can accommodate stators of different heights. Further, it may also be desirable to fix the distance of the muffler from the inlet to the compression mechanism to aid in properly tuning or packaging the muffler, while still accommodating these different stators.
Further still, it is known to resiliently support the motor/compressor assembly, which includes the motor and compression mechanism, within the hermetic shell or housing on a plurality of mounts affixed to the interior of the housing. Typically, these mounts are equally distributed about the interior circumference of the housing or otherwise placed thereabout in a manner which is merely convenient to attachment of the mounts to the motor/compressor assembly.
It is further understood by those of ordinary skill in the art that the housing has natural resonant frequencies that may produce loud, pure, undesirable tones when the housing is vibrated at or near those frequencies. Typically, equally distributing the mounts about the inner circumference of the housing may, at the points of contact therebetween, establish nodes which coincide with at least one of these natural frequencies. Similarly, placement of the mounts merely to facilitate convenient mounting of the motor/compressor assembly may also place these points of contact at nodes of natural frequencies which produce loud tones. Thus, previous compressors do not beneficially place the motor/compressor mounts on the housing in a manner which addresses the noise associated with excitation of these natural frequencies. To do so would reduce or eliminate the housing's natural resonant frequencies, and reduce the noise produced thereby.

Reciprocating piston compressor having improved noise attenuation


A method for producing ozone which comprises electrolyzing water using a fluororesin-type ion-exchange membrane as a solid electrolyte thereby to generate an ozone-containing gas, and cooling the gas thereby to remove a fluorine-containing substance present in the gas generated.

High-purity pure water (so-called ultrapure water) from which impurities have been removed to a high degree and which are used in semiconductor production, biotechnology, and other applications has reached a level of extremely high purity as a result of recent advances in ion exchange resin treatments or distillation techniques. At present, the electrical resistivity of high-purity pure water is close to 18 M.OMEGA./cm, i.e., a state in which almost no free ions are present in the water. However, even pure water having such a high degree of purity contains the dead cells of microorganisms, such as bacteria, and nonionic substances. These remaining impurities in the water are impossible to remove by an ion exchange method or distillation method, and contaminants such as these are an obstacle to further improving water purity. The amount of impurities which ultrapure water can contain is gradually becoming more restrictive, and present-day ultrapure water must contain less than 10 contaminant particles per milliliter (ml) with a size of 0.07 .mu.m or larger.
On the other hand, ozone is attracting attention as a powerful and clean oxidizing agent. The use of ozone, particularly for water treatment, is increasing since treatment with ozone is advantageous. For example, no residual substances are left in the treated water unlike conventionally employed chlorine-containing oxidizing agents. The lack of a residual substances is because the product of ozone decomposition is oxygen, and the decomposition rate of ozone is so high that ozone itself does not remain in the treated water. Hence, there are no problems of secondary pollution.
To improve the purity of ultrapure water, ozone treatment is performed preferably in combination with an ion exchange method or a distillation method. In conducting ozone treatment of water for producing ultrapure water having an improved purity, contamination of the water due to the ozone gas itself supplied for the treatment should be avoided.
For evolving gases containing ozone which is a useful oxidizing agent as described above, an electrical discharge method and an electrolytic method have been primarily employed conventionally. However, the electrolytic method is used typically because of its advantages of product purity and operational efficiency.
The electrolytic method, when carried out using a fluororesin-type ion-exchange membrane as a solid electrolyte, is capable of producing an ozone-containing gas having a far higher purity and ozone concentration as compared with the electrical discharge method. However, it was recently found that a slight amount of fluorine-containing substances is present in the ozone-containing gas generated by such an electrolytic method. This phenomenon had not been observed until recently and, hence, no method for removing such contaminants is presently known.


A system for delivery and refilling a dispenser of potable liquids provides a delivery container with rigid sidewalls and refill liquid containers with flexible sidewalls. Complimentary fitments on the dispenser and refill containers permit leak free docking under ascetic conditions when transferring liquid from the refill container into the liquid dispenser. The refill containers are easy to lift and handle, are used one time only and are then recycled. When empty the delivery container is nestable with others.

The traditional system for providing drinking water in offices, factories and homes includes a cabinet like drinking water dispenser for holding in the inverted position a five gallon glass or plastic bottle. Water flows from the open neck of the inverted bottle into a well portion of the dispenser from which, upon demand, the water flows by gravity through a conduit to a faucet actuated by the user seeking drinking water. Typically, one or more five gallon bottles are placed by the delivery person adjacent to the dispenser cabinet so that as one bottle is depleted it may be dismounted from the dispenser and a full bottle weighing about 45 lbs. may be mounted with a lift from the floor, and inverted into the dispenser cabinet. It is well known that a substantial effort is required to lift 45 lbs. from the floor to a position about 31/2 ft. there above and to invert the bottle. Persons of modest strength have difficulty completing the task of raising and inverting the fill bottle of drinking water but nevertheless, it must be accomplished periodically. The labor to deliver the containers to the place of use is considerable. The investment in transport equipment to carry the refill containers is substantial.
Generally, the filled bottle of drinking water is closed by a removable cap which is stripped away from the neck of the bottle usually by the person reloading the water dispenser. While lifting, it is convenient but unsanitary for that person to place his/her hand on the bottle neck after the cap is removed. This has been an occasion of the drinking water becoming contaminated from germs from the hands. Presently, there is no way to safeguard handling the water refill bottle in a germ free condition so as to protect the drinking water from contamination. Further, when the empty bottle is removed from the dispenser well for a period of time, air borne materials could settle into the well and afford yet another point of contamination of the drinking water.
The traditional system for providing drinking water with respect to a dispenser cabinet requires that the water bottles be transported from the water bottle filling plant to the customer. Then the bottles are returned to the plant in the empty state. The two way transport in handling of rigid bottle accounts for a substantial amount of the cost and capital in a commercial drinking water delivery system. It would be highly desirable if the drinking water could be delivered and the container therefore retrieved in a compact state and sent on for recycling. The same conditions hold for other human consumable liquids and even syrups and condensed liquids such as coffees or teas, milk and the like.
In the prior art the usefulness of a pouch for holding a resupply of chemical additives, viscous soaps, industrial metal cutting lubricants or the like was recognized. The U.S. Pat. No. 4,322,019 to Smith discloses a pouch containing a viscous liquid soap for refilling liquid soap dispensers. There is no particular need in that or other applications for maintaining these liquids in an aseptic condition being that those liquids are not intended for human ingestion. The principal concern then was to maintain control over the liquid against leakage during the refill operation. Providing a seal over the neck of a water bottle wherein the seal is pierced during installation into a water cooler is shown in the Wagner U.S. Pat. No. 1,142,210. Avoidance of undesirable skin contact with a liquid contained within a pouch or sachet is disclosed in U.S. Pat. No. 3,288,178 to Johnson wherein an attachment is provided to the bottle to be filled, the attachment serving to penetrate the pouch so that the corrosive liquid may drain without human contact into the associated bottle. None of the prior pouch systems showing membrane puncture or adapter structure therefore were intended and designed to be used in an aseptic drinking water delivery system.


A method of controlling a comparator includes during a first time period, enabling an auto-zero loop to provide an initial offset calibration of a differential preamplifier that includes differential memory capacitors; and during a second time period after the first window, enabling a self-calibrating circuit to provide an offset calibration of the differential preamplifier, and minimizing an output offset of a dynamic latch. Wherein the dynamic latch is configured to latch an output of the differential preamplifier at a sampling frequency, the auto-zero loop including an auxiliary amplifier configured to inject a correction signal into the differential preamplifier based on a voltage across the differential memory capacitors, and the self-calibrating circuit including a charge pump configured to adjust the voltage across the differential memory capacitors based on an output of the dynamic latch.

Analog voltage or current comparators are widely used building blocks in electronic circuits that have an input stage, which is optimized for low-offset operation. For example, the comparator is the basic analog-to-digital interface element for wireless and very-large-scale integration (VLSI) systems, analog/mixed ICs and analog-to-digital converters (ADC's).
A comparator can be a device, which compares a signal voltage (VIN) on one input with a reference voltage (ground) on its other input that generates a digital output being logic 1 or 0 when one of the signal levels is greater than the other. The comparator's external pins include a differential pair having a non-inverting input (+), an inverting input (−), and the comparator generally also includes an output pin.

Two step high speed auto-zero and self-calibration comparator


Under the present invention, prerequisites are first determined on a server for one or more OSGi bundles that are to be loaded on a client device. Once determined, the prerequisites are communicated to the client device. Upon receipt, the client device will determine whether it has/meets the prerequisites. If not, any prerequisites that the client device does not have represent resource limitations that are communicated back to the server in a response. The server will then recursively resolve the prerequisites by identifying a final set (e.g., one or more) of OSGi bundles that fulfill the prerequisites within the resource limitations of the client device. Once all prerequisites are resolved, the final set OSGi bundles can be loaded on the client device.

1. Field of the Invention
In general, the present invention relates to a method, system and program product for resolving prerequisites for client devices in an Open Service Gateway Initiative (OSGi) framework. Specifically, the present invention allows OSGi bundle prerequisites to be resolved while making efficient use of low bandwidth and/or high costs connections.
2. Related Art
As computer networking has become more advanced, a standard known as the Open Service Gateway Initiative (OSGi) has been developed. The OSGi is an industry plan to provide a standard way to deliver managed services to devices and local networks. With such a standard, home users could, for example, change the setting on their thermostat from a remote location (e.g., the workplace). In general, the OSGi provides a good framework for developing application components. Under the OSGi, a basic component is known as an OSGi bundle. An OSGi application can be made up of combinations/suites of bundles that might share common functionality. To this extent, the OSGi allows developers to define the dependencies between the bundles such as the packages and services required by the bundles. In a typical implementation, an OSGi architecture will include, among other components, a server and one or more client devices. Each client device will have an OSGi environment within which OSGi applications are deployed. Using a management program on the server, the functions of the OSGi applications can be controlled.
Unfortunately, as convenient as the OSGi framework can be, it currently fails to provide an efficient way to resolve prerequisites for OSGi bundles that are to be loaded on a client device. Specifically, a particular OSGi bundle might require that the client device have certain services, packages or computer resources (e.g., threads, RAM, etc.) to be properly run. If the client device fails to have the necessary prerequisites, the resource shortages should be addressed, or the OSGi bundle should not be loaded. The previous attempts at providing prerequisite resolution involved information flow solely from the client device to the server. Specifically, the client device would identify the OSGi bundles it had loaded thereon (e.g., by names and versions) to the server. The server would then use that information to look up the prerequisites in a repository or the like, and attempt to build a complete picture of the client device. Several disadvantages are posed with such an embodiment. First, since a single client device could have numerous OSGi bundles, communicating information about each one to the server is a large waste of bandwidth. Moreover, having the server receive the information and determine the prerequisites requires the server to be "all knowing" about the client device. This would disable the support of multiple management domains on a single client device. It would also break the process as soon as software appears on the client device that is not in the server's repository.
In view of the foregoing, there exists a need for a method, system and program product for resolving prerequisites for client devices in an OSGi framework. Specifically, a need exists whereby prerequisite resolution can occur while making efficient use of low bandwidth and/or high cost connections between the server and a client device.

Resolving prerequisites for a client device in an open service gateway initiative (OSGI) framework

INTERNATIONAL BUSINESS MACHINES CORPORATION


A base station comprises a plurality of antennas. Each of the antennas is separated by a known distance. A first spread spectrum signal is transmitted having a first code. Using the plurality of antennas, a second spread spectrum signal is received having a second code. The second spread spectrum signal is time synchronized with the first spread spectrum signal. A distance determination is made based on in part a timing difference between the second code of the received second spread spectrum signal and the first code of the base station's transmitted first spread spectrum signal. A phase difference of a carrier signal of the second spread spectrum signal as received by each of the plurality of antennas is compared. An angle of the received second spread spectrum signal is determined using the known distance between the antennas and the phase difference. A location of a source of the second spread spectrum signal is determined using the determined angle and the distance determination.

Wireless systems capable of locating a subscriber are presently known in the art. One wireless technique uses the global positioning system (GPS). In GPS, the communication handset receives data transmitted continuously from the 24 NAVSTAR satellites. Each satellite transmits data indicating the satellite's identity, the location of the satellite and the time the message was sent. The handset compares the time each signal was received with the time it was sent to determine the distance to each satellite. Using the determined distances between the satellites and the handset along with the location of each satellite, the handset can triangulate its location and provide the information to a communication base station. However, the incorporation of a GPS within a subscriber unit increases its cost.
Another subscriber location technique is disclosed in U.S. Pat. No. 5,732,354. A mobile telephone using time division multiple access (TDMA) as the air interface is located within a plurality of base stations. The mobile telephone measures the received signal strength from each of the base stations and transmits each strength to each respective base station. At a mobile switching center, the received signal strengths from the base stations are compared and processed. The result yields the distance between the mobile telephone and each base station. From these distances, the location of the mobile telephone is calculated.
Wireless communication systems using spread spectrum modulation techniques are increasing in popularity. In code division multiple access (CDMA) systems, data is transmitted using a wide bandwidth (spread spectrum) by modulating the data with a pseudo random chip code sequence. The advantage gained is that CDMA systems are more resistant to signal distortion and interfering frequencies in the transmission path than communication systems using the more common time division multiple access (TDMA) or frequency division multiple access (FDMA) techniques.
There exists a need for an accurate mobile subscriber unit location system that uses data already available in an existing CDMA communication system.

Base station using an antenna array for location determination


A lithium secondary battery including a negative electrode having has been inserted an active material at least one member selected from the group of metallic lithium, lithium alloys and materials which are capable of electrochemically occluding and releasing lithium ions; a positive electrode having an active material consisting of at least one compound which is capable of electrochemically occluding and releasing lithium ions; and an organic electrolyte. The solvent for the organic electrolyte is composed mainly of a mixture solvent prepared by mixing an organic solvent indicated by Formula I, 4-trifluoromethyl-1,3-dioxolane-2-one, and one or two selected from the group of organic solvents indicated by Formula II, 1-trifluoroethylmethyl carbonate, and an organic solvent indicated by Formula III, di-1-trifluorethyl carbonate, as mentioned below. As a result of using the solvent which contains the above-mentioned mixture solvent as a main component for the electrolyte, a lithium secondary battery with improved high-rate discharge characteristics, cycle characteristics and safety characteristics is obtained. ##STR1##

Field of the Invention
This invention relates to a lithium secondary battery
Description of the Related Art
With recent rapid progress in the field of electronic industries, electronic devices have been made higher in performance, smaller in size and portable. As such, the development of these devices has generated considerable demand for secondary batteries with high energy density which can be used for these electronic devices.
As a secondary battery to be used for these electronic devices, lead acid batteries, Ni-Cd (nickel-cadmium) batteries or Ni-MH (nickel-hydrogen) batteries have been conventionally used. In addition to them, lithium secondary batteries which use metallic lithium or carbon material capable of electro-chemically occluding and releasing lithium ions as an active material of a negative electrode, and oxide materials containing lithium capable of electro-chemically occluding and releasing lithium ions as an active material of a positive electrode, have been put into practice and widely used.
Lithium secondary batteries of this kind have, as compared with other conventional batteries, high discharge voltage and high energy density per unit volume or unit weight. Therefore it is said that they are the most promising secondary batteries today.
Presently, as an electrolyte used in this kind of lithium secondary batteries, there has been used a lithium salt such as LiPF.sub.6, etc. dissolved in a non-aqueous mixture solvent wherein the main component is a mixture solvent of an organic solvent such as propylene carbonate, etc. , which has dielectric constant, and an organic solvent such as methyl ethyl carbonate, etc., which has low viscosity. (see Tokkai-Hei 6-13109)
However, this kind of lithium secondary battery has such a problem that the organic solvents in the electrolyte is decomposed during charging, and the battery capacity is decreased by repetition of charge-discharged cycles. Therefore, the improvement in the length of battery life has been desired.
Also, since these conventional electrolytes are combustible, the lithium secondary battery using this kind of electrolyte has such dangers as firing or explosion when it is mishandled, as compared with such batteries using the aqueous electrolyte such as lead acid, Ni-Cd battery or Ni-MH battery.


An aircraft having a high lift system, including a control computer, high lift bodies on each wing, a drive coupled to these, an activation device connected to the drive via an analog connection, an input device, and sensors detecting a state of the high lift bodies connected via analog lines to the activation device. The input device connects via a digital connection to the activation device for transmitting commands for adjusting the high lift bodies. The activation device is installed in the payload area of the fuselage and in an area extending from a location spaced from the front of the wingbox by a distance of one third of the fuselage length extending from there to the aircraft's tip, as far as a location spaced from the rear of the wingbox by a distance of one third of the fuselage length extending from there to the aircraft's tail end.

From the general prior art it is known to activate and monitor drive mechanisms of adjustable lift bodies or flaps such as, e.g., landing flaps or slats of high lift systems of modern civil as well as military transport planes through central digital computers. These are located, together with other computers such as the flight control computers or maintenance computers, in the board calculator cabinets in a so-called avionics bay positioned in the vicinity of the aircraft's cockpit. In consequence, particularly the safety-sensitive aircraft computers are accommodated inside one room while being air-conditioned and supplied with electric power in a uniform manner. The accommodation of the named computers in one and the same avionics bay or in a single accommodation space presents the advantage of uniform atmospheric conditions—which create the technical preconditions for observing the failure rate of these computers, for instance—having to be established for the single accommodation space only.
Accordingly, all of the components of the high lift system external of the avionics bay are connected via analog signal connections to the activation computer thereof. Thus, e.g., the drive motors of the high lift systems provided for adjusting the landing flaps or leading edge flaps (slats), the operating lever (slat/flap levers), as well as the sensors for component and system monitoring are functionally connected via analog signal connections to the activation computer for activation the landing flaps and locking brakes. In this way it is ensured that the functional demands to the high lift system and particularly to the activation computer thereof are met, for the activation and monitoring signals are transmitted immediately and thus at a minimal time delay between the input device of the high lift system such as the operating lever, for example, and the activation computer of the high lift system as well as between the activation computer and the drive motors or the drive device of the high lift system. The described use of analog signal transmission lines particularly results in advantages with regard to the realization of a safety concept, for hereby the delay time or dead time between the occurrence of a fault and its recognition and corresponding functional reactions in the activation device, such as triggering the locking and safety brakes is minimized, and in the event of a fault the reconfiguration of the high lift system may therefore be carried out within a comparatively short time period.


The present invention relates to the prevention of coronary artery spasm in mammals by the administration of an effective amount of an antiestrogen compound to block estrogen receptors for the reduction or prevention of the formation of an estrogen--estrogen receptor complex so that estrogen response elements in the DNA of the smooth muscle of the coronary arteries is not activated by the complex. The method of the invention is used to reduce the risk of spasm induced cardiac problems such as sudden infant death syndrome. The antiestrogen is selected from the group consisting of progestins and nonsteroidal antiestrogen compounds.

Sudden Infant Death Syndrome (SIDS) is a medical term that describes the sudden death of an infant which remains unexplained after all known and possible causes have been carefully ruled out through autopsy, death scene investigation, and review of the medical history. Nearly 90% of the deaths occur in the first six months of life.
There has been much study into the causes of Sudden infant Death Syndrome (SIDS)in recent years. Incidences of this tragic syndrome have received wide publicity and many studies of SIDS have been conducted. Pediatricians and others studying the syndrome have emphasized the placement of the infant in its crib in an attempt to prevent the onset of SIDS. Many hypotheses have been formulated and presented as to the cause of the syndrome, including such causes as choking and asphyxiation from lack of oxygen. Accordingly, conventional wisdom now is to place an infant on its back to decease the incidence of SIDS which has met with limited success. Even so, SIDS continues to occur among infants for no apparent reason and, to date there is no consensus as to the cause of SIDS.
There are other unexplained incidences of nocturnal death in young adults as well as in infants which exhibit characteristics similar to SIDS. For example, in Asia sudden unexpected death during sleep has been reported among young Asian and Oceanian males around the age of 25. This syndrome, which is named Sudden Unexpected Nocturnal Death syndrome (SUNDS) is also known as Pokkuri Disease in Japan and Bangungut in the Philippines. SUNDS rarely occurs in menstruating females and SUNDS among Caucasians is rare as compared to Asian and Oceanian populations but does occur occasionally. See for example, R. Myerburg Sudden Death. The Heart, McGraw, Hill, New York, 1978, page 732.Sudden unexplained death among older Japanese males around age 40, during sleep is also sufficiently common as to have been named "Karoshi" (dying from exhaustion).

Method for the prevention of coronary artery spasm


An object of the present invention is to provide an optical system for an infrared ray which can provide a bright image, and can be applied to fixed focal length lenses among wide-angle to medium-telephoto. To achieve the object, the optical system for an infrared ray is constituted by a first lens having negative refractive power and a second lens having positive refractive power, these are arranged sequentially from an object side, wherein both the first lens and the second lens are made of an infrared transmitting material that transmits a light beam in an infrared wavelength range of 3 micron-meters or more to 14 micron-meters or less, and at least one of the lenses is made of an infrared transmitting material excluding germanium.

Technical Field
The present invention relates to an optical system for an infrared ray used in an infrared wavelength range.
Background Art
Conventionally, optical systems for an infrared ray are used for analysis of heat distribution of an object in medical and industrial fields in addition to surveillance and personal authentication. In recent years, applications of optical systems with an infrared ray have spreading into onboard cameras, and are also spreading into various applications not only surveillance, travel record and driving support but also detection of pedestrians and obstacles at night. With increasing in the applications of the optical systems for an infrared ray, a fixed focal length lens having a small F-number which can provide a bright image has been demanded rather than a zoom lens with a variable focal length.
The optical system for an infrared ray is generally constituted by a combined plurality of lenses made of infrared transmitting materials including germanium having a high refractive index for an infrared ray. For example, Patent Document 1 discloses a wide-angle optical system for an infrared ray constituted by a first lens composed of a meniscus lens whose convex surface faces an object side, and a second lens and a third lens composed of positive meniscus lenses whose convex surfaces face the object side these are arranged sequentially from the object side. Patent Document 2 discloses a bright optical system for an infrared ray constituted by a first lens composed of a positive meniscus lens whose convex surface faces an object side, and a second lens composed of a positive meniscus lens whose convex surface faces an imaging side these are arranged sequentially from the object side and has a small F-number.


A method for manufacturing an assembly including a stack of at least two primary parts, the primary parts being joined together around their periphery with the exception of a place forming a passage so as to define between the two of them a cavity, and the primary parts having, facing the cavity, at least one face that is covered, in a pattern, with a stop-off product containing a binder that can be thermally degraded, and a sealed reservoir having an open end, the end being joined in a sealed manner to the passage in the stack so as to allow communication between the internal space of the reservoir and the cavity, the reservoir being placed under a partial vacuum, this being produced so as to be non-deformable at the temperature and at the pressure at which the diffusion bonding of the said stack takes place.

It will be recalled that the diffusion bonding technique consists in bringing two surfaces of a given material into contact with each other at high temperature and under a certain pressure for a certain time. The two surfaces then bond together by atomic diffusion, this having the advantage of forming a bonded structure equivalent to the base structure of the material.
Of course, the quality of the bond depends on the operating parameters: temperature, pressure and time, but also parameters associated with the components to be joined together, generally in the form of plates: metallurgical structure and surface finish (cleanness, roughness). Consequently, it is paramount to eliminate any source of contamination of the surfaces to be joined together before they are heated to the temperature for the diffusion bonding step.
This surface cleaning operation is conventionally carried out by creating a vacuum in the cavity formed by the two surfaces to be bonded together. However, in the case of diffusion bonding associated with superplastic forming, a stop-off product is used to prevent diffusion bonding in those regions of the facing surfaces that will be subsequently be inflated in order to obtain a hollow mechanical part.
This type of product is composed of a binder, generally an organic binder, and a powder of a diffusion barrier material, such as a refractory material like a ceramic (for example yttrium oxide or alumina or boron nitride), or graphite.
After application of the stop-off product in a defined pattern corresponding to those areas of the surfaces that are not to be joined together by diffusion bonding, the binder is degraded so as to conserve only the powder of the stop-off product, which is formed from particles that exhibit anti-adhesion properties, preventing the atoms of the materials of the plates to be bonded from diffusing.
During this degradation of the binder by raising the temperature to generally between 200 and 400° C., residues, particularly gas residues, form, which may contaminate, to various degrees depending on their chemical composition, the surfaces to be bonded.
Thus, it will be understood that is essential also to remove the degradation residues of the stop-off product.
It should be noted that the mechanical strength of the stop-off product is greatly reduced after this degradation, so that it is necessary to avoid manipulating and/or moving the parts to be bonded or to create disturbances within the cavity that could cause the particles of the stop-off powder to be disseminated in those regions of the surfaces to be bonded that have to be joined by diffusion bonding.
Conventionally, these degradation residues are reduced by creating a partial vacuum in the cavity formed by the two surfaces to be bonded.
It has also been proposed to circulate an inert gas, such as argon, in this cavity and then to create a partial vacuum in this cavity for the actual diffusion bonding step (FR 2 754 478).
This solution is relatively difficult to implement since it is necessary to install a system of pipes and fittings for circulation of the inert gas and for the subsequent vacuum created, this system also constituting a source of possible leaks and making the diffusion bonding operation more complex to implement. Furthermore, this solution allows only a single part to be treated at a time and the creation of a vacuum lengthens the manufacturing time.
In addition, it should be noted that when the binders volatilize the mechanical behaviour of the stop-off product greatly deteriorates in such a way that the flow of inert gas circulating in the cavity may result in local dissemination of the stop-off particles on the surfaces to be bonded.
Finally, it should be noted that despite the creation of a partial vacuum in the cavity at the end of degradation, the risk of retaining inert gas, trapped in certain regions of the cavity, is not zero, it being possible for such residual gas pockets to locally prevent diffusion bonding.
Moreover, U.S. Pat. No. 5,484,977 and U.S. Pat. No. 5,273,202 have proposed the elimination of the residues from the degradation of the binder for the stop-off products by the fact that the assembly is placed in a chamber under a dynamic partial vacuum, that is to say with continuous suction in order to extract the gases coming from the degradation of the binder.
Here again, it is difficult to treat several parts at the same time because of the volumes to be put under a partial vacuum, the treatment time is long, and it is necessary to install a large vacuum chamber. This makes the process expensive to implement.

Assembly for the manufacture of a hollow mechanical part by diffusion bonding and superplastic forming, use of such an assembly and process for manufacturing such a mechanical part


Calculating of signal-to-interference ratio (SIR) of a mobile device in a wireless communication system. A communication signal transmitted by the mobile device is non-coherently processed. Interference power of the communication signal is estimated and then scaled, and the scaled estimated interference power is subtracted from the processed communication signal to thereby estimate signal power. The SIR is calculated by dividing the estimated signal power by the estimated interference power.

Many wireless communication systems require the knowledge of the receiver signal-to-noise (and interference) ratio (SIR). SIR estimates are typically used in closed-loop power control, handoff, adaptive coding and modulation, MAP decoding for Turbo codes, etc.
Numerous methods exist for measuring the interference power associated with a received signal. One approach uses the total received power (which is typically received signal strength indication (RSSI)) at the automatic gain control (AGC) output of the wireless communications device.
Another approach uses re-modulation of a de-spread signal using either perfect knowledge of the transmitted sequence or tentative decisions in order to subtract signal components and measure non-orthogonal interference.
Still other approaches use estimations in which partial derivatives are set to zero to arrive at a maximum likelihood (ML) estimation, or estimates of the signal-to-noise variance are calculated, second and fourth order moments of the received signal are used to solve for S (signal power) and I (interference power), or a signal-to-noise variance ratio is determined using a moments method combined with usage of delayed received symbols.

Signal-to-interference ratio estimation for CDMA


Disclosed is a process for the preparation of an amine by contacting in a reaction zone a water-soluble aldehyde, water, ammonia and hydrogen in the presence of a supported ruthenium catalyst at elevated temperature and pressure. The process is particularly useful for the preparation of 3-(aminomethyl)tetrahydrofuran by contacting an aqueous solution of 3-formyltetrahydrofuran with ammonia and hydrogen at elevated temperature and pressure in the presence of a supported ruthenium catalyst. The use of a supported ruthenium catalyst has been found to avoid the problem of catalyst leaching encountered when a nickel catalyst is used.

The preparation of amines by the reductive amination of aldehydes using nickel-based catalysts is well known as shown, for example, by Freifelder, Morris, Practical catalytic Hydrogenation, John Wiley & Sons, Inc. 1971, pages 333-345, and has been utilized to manufacture a variety of amines such as 2,2-dimethyl-3-aminopropanol from hydroxypivaldehyde. Japanese Patent Publication JP 91-10848 A discloses the reductive amination of FTHF with aqueous ammonia using nickel, palladium, and platinum catalysts. Although this patent document claims better selectivity for the aqueous system, the best selectivity achieved by the use of palladium or platinum catalysts was 77.4% with 5% palladium on carbon at 30.degree. C. a higher selectivity of 99.5% was reported for Raney nickel at 60.degree. C. All of the examples were batch autoclave experiments and no problems with product isolation or catalyst instability resulting from the use of Raney nickel were mentioned.
U.S. Pat. Nos. 4,963,672 and 5,068,398 describe the reductive amination of 5-formylvalerates in liquid ammonia using a supported ruthenium catalyst. These patents teach that the disclosed processes are carried out at relatively high total pressures of 40 to 100 bar (580 to 1450 pounds per square inch-psi). The examples contained in the patents employed total pressures of 98 to 99 bar. U.S. Pat. No. 5,068,398 discloses a comparative example that demonstrates leaching of nickel from a supported nickel catalyst. U.S. Pat. No. 5,166,443 describes a two-step process wherein certain 2,2-disubstituted-4-cyanobutanal compounds are converted to their corresponding diamines. The first step involves treating the cyanobutanal with ammonia in the presence of an acidic heterogeneous catalyst. The resulting material then is fed to a hydrogenation zone which preferably uses a ruthenium catalyst. Again, the pressures are relatively high at 50 to 500 bar (725-7250 psi), preferably 100 to 350 bar and most preferably from 150 to 300 bar. In the examples of U.S. Pat. No. 5,166,443, the hydrogenation zone is operated at a pressure of 200 or 250 bar.
Initial attempts to prepare 3-(aminomethyl)tetrahydrofuran (AMTHF) by contacting an aqueous solution of 3-formyltetrahydrofuran (FTHF) with ammonia and hydrogen in the presence of conventional Raney nickel or supported nickel catalysts did not give satisfactory results due to significant leaching of nickel into the product. In addition to losing catalyst, product isolation and purification becomes more difficult due to precipitation of nickel salts upon removal of the excess ammonia and water. During removal of the ammonia and water by distillation, pale green salts precipitate and must be removed by distillation, filtration, or both.
The FTHF from which AMTHF may be prepared preferably is used in the form of an aqueous solution. As is disclosed by W. A. Beavers in U.S. patent application Ser. No. 944,653 filed Oct. 6, 1997, FTHF may be prepared by hydroformylation of 2,5-dihydrofuran in the presence of a rhodium-phosphine catalyst and an organic, water-immiscible, hydroformylation solvent. Recovery of FTHF by distillation in the presence of the hydroformylation solvent results in the formation of hemiacetal oligomers and an overall significant yield loss. Thus, the FTHF product preferably is recovered by first extracting the hydroformylation product solution with water to produce an aqueous solution of FTHF. The use of this aqueous solution of FTHF in chemical processes wherein the FTHF is converted to other compounds such as AMTHF is a particularly efficient means for producing such other compounds.


A continuously operating double band press for the production of material webs, a shape compensating plate and a discontinuously operating single or multiple-platen press for the production of materials in portions is disclosed. Shape compensating plates are arranged in the press frame of the double band press or at the pressing plates of the platen press. The shape compensating plate comprises two plates of metal which are parallel arranged. An elastic bellows serving as a lateral seal is fastened at its edge to extend annularly. The chamber formed by the plates and the elastic bellows is filled with a fluid medium.

Double band presses may be used for the continuous production of endless web-shaped work materials, particularly for the production of decorative laminated materials, copper-lined electrolaminates, thermoplastic webs, chipboards, fiberboards and the like. These double band presses may comprise two continuous circumferentially extending press bands between which the material web is cured under pressure and possibly heated while being transported in the feed direction. Pressure plates in the press frame of the double band press produce the area pressure transmitted from the pressure plates to the inner sides of the press bands and from the press bands to the work material web.
Two different working principles for transmitting the pressure from the pressure plate to the inner side of the press band involve the isobaric and isochoric machines. In isobaric machines (see, e.g. DE-PS 27 22 197), annularly self-contained sliding-surface or packing or floating seals are arranged along an edge of the pressure plate and placed against the press band so that the press band slides during the operation of the double band press. Pressure chambers are thereby formed which are defined, in the vertical direction, by the pressure plate and by the inner side of the press band and, in the horizontal direction, by the floating seals. A fluid pressure medium, e.g. oil or compressed air, is introduced into these pressure plates.
In isochoric machines, the pressure is mechanically transmitted via rolls, from the pressure plate to the inner side of the press band. A stationary roll bed arranged in the pressure plate is known from DE-OS 31 23 291. The roll bed comprises rolls which are offset relative to one another and supported by shafts in bearing strips which are fastened in the pressure plate.
DE-OS 33 04 754 discloses a double band press which combines the isobaric and isochoric principles. A roll bed is arranged in a pressure cushion which is sealed at the sides by floating seals. This press can be operated in a purely isochoric manner in that only the roll bed is placed against the press band without introducing a fluid pressure medium under pressure into the pressure cushion. A purely isobaric operation is also possible in that the roll bed is not placed against the press band and only a fluid pressure medium maintains the pressure in the pressure cushion. In the combined isobaric/isochoric type of operation, the roll bed is placed against the press band and a fluid pressure medium is introduced into the pressure cushion. In this double band press, an additional pressure chamber is used for exerting a pressure on the roll bed. This pressure chamber is arranged at the side of the pressure plate remote of the press band and is defined in the vertical direction by the pressure plate and by a closure located in the press frame and in the horizontal direction by lateral seals which are constructed identically to the floating seals for the pressure cushion. The pressure plate and the roll bed located in the pressure plate are placed against the press band by introducing a fluid pressure medium into this pressure chamber.
Unfortunately, however, when such double band presses are operated in the combined isobaric/isochoric operation, a leakage of fluid pressure medium can occur at the lateral seals of the pressure chamber at the side of the pressure plate remote of the press band, particularly at higher pressures. Furthermore, the press frame and material to be pressed can be soiled and often requires treatment when pressing at increased temperature. The pressure plate is heated to the required temperature for this purpose.
Sealing materials for lateral seals comprise plastic or elastomers which can resist temperatures up to only about 270.degree. C. The lateral seals of this pressure chamber are therefore destroyed at higher temperatures, leading ultimately to a failure of the pressure chamber to apply pressure and to a time-consuming and costly repair of the double band press. Such double band presses are consequently not suitable for use at higher temperatures.
To overcome these and other drawbacks of previously known presses, it is an object of the invention to develop an isochoric or combined isochoric/isobaric double band press to operate reliably at increased temperatures.
Another object of the invention is to provide a press in which no leakage of pressure medium can occur in the shape compensating plate due to a hermetic lateral edge seal.
A further object of the invention is to provide a press in which soiling of the press and material to be pressed is reliably prevented.
Another object of the invention is to provide a double band press with a shape compensating plate in which there is much less waste of the material to be pressed than in previous double band presses.
Yet another object of the invention is to provide a double band press in which the shape compensating plate contains no plastic, so that the double band press can also be used for high temperatures.
Still another object of the invention is to provide a double band press which compensates for bending in the pressing region of the press, particularly bending of the press frame by a shape compensating plate so that a product with improved dimensional stability is produced on the double band press.
A still further object of the invention is to provide a press having a good thermal fluid pressure medium in a shape compensating plate, using, for example, metallic fluids which demonstrates good thermal conductivity so that an unimpeded transfer of heat is ensured between the press bands and a heat exchanging plate in a plane-parallel manner in the press frame.
Yet another object of the invention is to provide a double band press in which material of different widths to be processed by using a shape compensating plate divided into a plurality of individual strip-shaped shape compensating plates arranged adjacent to one another.
Additionally, it is an object of the invention to provide a double band press comprising a shape compensating plate which can be used not only in continuously operating double band presses, but also in discontinuously operating single or multiple-platen presses.

Continuously operating double band press with a shape compensating plate structure including a deformation-limiting supporting plate


A method and system is disclosed for passing a transmit/receive control signal and a power signal through a coax cable from a base transceiver station to a tower top device in a time division duplex communication system. After generating the transmit/receive control signal and a radio frequency signal for communications, the transmit/receive control signal modulates a separate timing control operating on a separate control frequency. It is then multiplexed on at least one coax cable along with the radio frequency signal and DC power. At the tower top device, the modulated transmit/receive control signal is converted back to a DC level for providing a time division duplex control reference.

The present invention relates generally to a wireless communication system design, and more particularly to a multiplexing system for time division duplex (TDD) wireless systems that uses a coax cable for simplifying assembly of remote towers in TDD systems.
A TDD system is designed to transmit and receive on the same frequency in different time slots, the mechanism of which is well known by those skilled in the art. Various literatures have described in theory and applicable detail the TDD systems that are deployed in the telecommunications industry today (e.g., Roger Freeman, "Radio System Design for Telecommunications", Wiley-Interscience, 2nd Edition, April 1997). TDD systems alternated between transmit or receive on the same frequency while FDD systems simultaneously transmit and receive on different frequencies.
A basic remote tower in TDD systems typically includes tower top device such as transmit and receive amplifiers and a ground device such as a transceiver. An amplifier that is placed far and away from a transceiver of the TDD system is typically called a remote amplifier. For a remote amplifier operating in TDD mode, both DC power and a transmit/receive controlsignal to indicate transmit or receive state must be fed from the transceiver to the amplifier. In transmit state, the transmit remote amplifier must be active and the receive remote amplifier must be inactive. In receive state, the receive remote amplifier must be active and the transmit remote amplifier must be inactive. This transmit/receive control signal signal, in the form of a DC level, is typically sent from the transceiver to the amplifier via a dedicated cable. However, a dedicated cable is expensive to implement and equally costly to maintain.
Alternatively, various designs allow the transmit/receive control signal to be passed wirelessly from the transceiver to the amplifier. However, if not implemented properly, aerial interference may interfere with the wireless link so much so that a high error rate, and a correspondingly costly corrective mechanism, is inevitable.
Alternatively, the DC level of the transmit/receive control signal is known to be injected directly into the RF cable that runs the length between the transceiver and the amplifier. This is accomplished by using a bias tee, which is a signal conditioning element that allows DC and RF signals to be applied to a single communication device. However, this design is problematic because the DC level change is difficult to separate from DC power injected onto the same cable. Changes in the power requirement of the remote amplifier that can cause the DC level at the remote amplifier to shift independent of the transmit/receive control signal.
For the reasons above, it is desirable to design a more reliable system that can be used for sending the transmit/receive controlsignal from the base transceiver station to the tower top amplifier.

Multiplexing system for time division duplex communication systems


A light-emitting device having an anode and a cathode is disclosed herein. An embodiment of the light-emitting device comprises a first lead connected to the anode of the light-emitting device and a second lead connected to the cathode of the light-emitting device. The first lead has a first bend, wherein the direction of the first bend indicates that the first lead is connected to the anode. The second lead has a second bend, wherein the direction of the second bend indicates that the second lead is connected to the cathode.

Many light-emitting devices have a light-emitting diode or similar device located therein that serves as a light source. A light-emitting diode requires a forward current to pass through it in order to emit light. Therefore, when a light-emitting device is connected to a circuit or the like, the polarity must be correct; otherwise, no light will be emitted.
Many light-emitting devices have markings to indicate cathode and anode in order to connect them correctly. However, as light-emitting devices get smaller, it is difficult to see these markings, which can lead to incorrectly connected light-emitting devices.

Avago Technologies ECBU IP (Singapore) Pte. Ltd.


A machine tool is provided with a base, a tool rest and a boring bar magazine. The tool rest is mounted on the base and retains a boring bar. The tool rest is moved in a first direction in parallel with an axis of the main spindle and in a second direction perpendicular to the first direction. The magazine is located opposite to a headstock and stocks the boring bars and swivels and indexes the boring bar. The tool rest is moved whereby the boring bars are changed by other ones between the tool rest and the magazine. Thus, the tool rest is moved in at least two directions so that the boring bars are changed between the tool rest and the magazine.

1. Field of the Invention
The present invention relates to a machine tool, having a boring bar magazine which may incorporate boring bars, which may perform turning with the boring bar.
2. Description of the Related Art
Boring bars are categorized in terms of types into regular boring bar, of which a length is 4 to 5 times longer than a diameter, and long boring bar having a length longer than the length of the regular boring bar. A technology relating to a machine tool in which a boring bar is mounted on a tool rest to turn a workpiece is disclosed in Japanese Patent Application Laid-Open No. 2003-80408 and Japanese Patent Application Laid-Open No. 64-2839.
The machine tool disclosed in the Japanese Patent Application Laid-Open No. 2003-80408 is structured that the tool rest may be moved in any directions of axes X, Y and Z. Also, in this machine tool, two devices for transferring the boring bar, in which boring bars are laid on their tables respectively, are juxtaposed in the Y-axis direction.
However, the devices for transferring the boring bar are not moved in the Y-axis direction. For this reason, the tool rest has to be moved also in the Y-axis direction in addition to the X-axis and Z-axis directions. As a result, there is a problem that the machine tool as a whole is complicated because of the necessity of means for moving the tool rest in the Y-axis direction.
Also, because the devices for transferring the boring bar are juxtaposed in the Y-axis direction, there is also a problem that it is impossible to increase the number of the boring bars which may be incorporated therein.
Japanese Patent Application Laid-Open No. 64-2839 discloses a lathe having a tool stocking device (boring bar magazine) which may stock a plurality of tools (boring bars). This tool stocking device is adapted to stock the plurality of tools and to make a swivel motion and is mounted on a headstock.
However, a heat generating source such as a motor is located in the headstock. For this reason, there is a fear that the heat generated in the headstock would propagate to the tool stocking device so that the tools stocked in the tool stocking device might be thermally deformed. On the other hand, when the tool stocking device is operated during machining with the lathe, there is also a fear that a vibration of the tool stocking device would propagate to the headstock so that an adverse affect such as degradation in machining accuracy would occur.
Further, because the tool stocking device is located on the headstock, a motor, a pulley, a partitioning plate and the like of the headstock would obstruct. As a result, an operator could not perform the operating work or the maintenance work by extending his or her hands from a front side of the lathe. The load imposed to the operator is high.
In another known machine tool, a clamping and unclamping mechanism is used for clamping a tool holder of a boring bar to the tool rest. In this conventional clamping and unclamping mechanism, a clamping part having a predetermined shape such as a T-shape is interposed, and the clamping part is drawn by a piston or the like. Thus, the tool holder is indirectly drawn and clamped through the clamping part.
However, according to this prior art, because the clamping part is needed, a dimension from a center of the tool rest to a centerline of the tool holder is elongated. As a result, when a workpiece is turned by the boring bar, a moment due to a force applied to a machining position is increased. Accordingly, there is a problem that a large stress is applied to the position adjacent to the clamping and unclamping mechanism. Also, there is a tendency that the rigidity of the tool rest and the tool holder as a whole would be reduced.


The present invention relates to a method for estimating the motion of a get relative to an observer station and a system for performing the method. The method includes the steps of: generating data representative of the motion of the target relative to the observer station during first, second, and subsequent measurement legs; processing the data to yield smoothed estimate of the bearing, bearing rate, and bearing acceleration of the target during each measurement leg; and processing the smoothed estimates of the bearing, bearing rate, and bearing acceleration of the target to provide an estimate of the position of the target relative to the observer station and the velocity of the target. The system for performing the method includes a data preprocessing subsystem for generating the smoothed estimate of the bearing rate, bearing and bearing acceleration, a passive localization and target motion analysis subsystem, and a trajectory modelling subsystem having a first module for creating a model of the observer station motion and a second module for creating a model of the motion of the target.

(1) Field of the Invention
The present invention relates to a method for estimating the motion of a target relative to another object such as a marine vessel and to a system for performing the method.
(2) Description of the Prior Art
A variety of techniques and methods for target motion analysis (TMA) and tracking are known in the art. The purpose of many of techniques and methods is to arrive at an estimation of the bearing and range, as well as the course and the speed, of the target being tracked. One of the principal goals associated with these techniques and methods is to provide accurate and timely estimates of the target's motion.
U.S. Pat. No. 5,216,815 to Bessacini illustrates a method for determining range from a moving vessel to an approaching object using only two bearing measurements. In this method, a first bearing measurement to the approaching object is obtained at a first point in time using the vessel's conventional bearing sensor. The vessel and the approaching object are then postulated to be on an intercept course based on the first vessel's velocity vector and first bearing measurement. At a second point in time, the vessel commences a maneuver to a known second velocity vector different from the first velocity vector. Then, at a third point in time, a second bearing measurement to the approaching object is obtained using the vessel's bearing sensor. At the same third point in time, a virtual bearing to the approaching object is provided as if the vessel and the approaching object were on the postulated intercept course. A time difference is computed between the second and third points in time and standard trigonometric methods are applied to determine the range to the approaching object.
U.S. Pat. No. 5,317,543 to Grosch illustrates a method and a sensor for determining the distance of sound generating targets from acoustic signals which are subjected to a Fourier transformation. In order to determine the target distance, it is postulated that the acoustic signals received by an acoustic sensor at two successive points in time are from a target at distances r.sub.1 and r.sub.2, respectively, from the acoustic sensor. After the Fourier transformation, an evaluation of the phase difference in the sound spectrum yields the difference between the distances of the target from the sensor at the two points in time, from which difference the target distance is then calculated according to a spherical wave model.
U.S. Pat. No. 5,471,433 to Hammel et al. illustrates a trajectory estimation system for estimating a trajectory of a target in response to a series of data items which are generated in response to the motion of the target. The trajectory estimation system includes a data segmentation means and a trajectory selection means. The data segmentation means process the series of data items in accordance with a regression/multiple hypothesis methodology to generate a plurality of segments, each having associated data items which have similar features. The trajectory selection means for processing the segments in accordance with a multiple-model hypothesis methodology to generate a corresponding statistically supportable candidate trajectory motion estimate of target motion thereby to provide indicia of an overall trajectory of the target.
U.S. Pat. No. 5,471,434 to Davis et al. illustrates a system for facilitating the tracking of a target vehicle in connection with successively received acoustic sensor signal data items. A fast Fourier transform operation is performed in connection with each successive acoustic sensor signal data item to generate a phase and amplitude beam map reflecting spectral signal energy in the received acoustic sensor signal data item. If the beam map for an acoustic sensor signal data item indicates that the item represents a signal having a signal-to-noise ratio above a first predetermined threshold value, a beam map generated for a previous acoustic sensor signal data item is used to generate a bounded beam map, a determination is made as to whether the bounded beam map represents a signal having a second predetermined signal-to-noise ratio. In response to a positive determination for the latter signal-to-noise determination, both the beam maps are used to generate tracking information for the target vehicle.
U.S. Pat. No. 5,432,753 to Maranda illustrates a system for target detection and localization with an algorithm for performing TMA using data from a passive sonar array and which works directly with beam spectra to estimate the target track. The system determines when the coordinate trajectory of a hypothesized target aligns with the coordinate trajectory of an actual target and operates by forming long-term integrated spectral values from short-term values of frequency and angle coordinate values. The hypothesized target track that yields the maximum long-term integrated spectral value is used as the estimate of the true target track. A track generator is used to generate hypothesized target tracks for a search grid in the form of vectors that are clocked downward in a chain of latches. The latches are connected through computational elements, which are supplied with non-acoustic data, and RAMs to a summation pipeline, the RAMs being supplied with data from an array's sonar processor. The computational elements compute and provide angle and frequency addresses to the RAMs, whose outputs are applied to adders in the summation pipeline. Each RAM holds data for a single two-dimensional FRAZ spectrum. The summation pipeline supplies a completed sum of short-term spectral values at its output to provide the required long-term integrated spectral values.
Yet another method for determining range is known as Ekelund ranging. This is a widely used method of target localization. One of the deficiencies of present Ekelund methods is that they fail to fully exploit all available target data and provide only single epoch range estimates with no mechanism for refinement.
Under actual operating conditions, the measurement process for Ekelund ranging computations consists of discrete time series of target bearings corrupted by errors and taken while the observer vessel travels along a trajectory comprised of constant-velocity segments ("legs") interspersed with maneuvers. Here, a maneuver is defined as a non-zero change in the course and/or speed of the observer platform. At least two measurement legs of data are required for the estimation process to become observable (feasible). The measurement time series is subdivided into distinct sequences, each corresponding to a particular leg of the observer vessel. These sequences are then processed to provide smoothed estimates of target bearing, bearing rate, and bearing acceleration, which are time indexed to the midpoint of the appropriate leg. Finally, this data is made available for TMA computations.
Current Ekelund ranging procedures are designed to use only two measurement legs for range estimation and totally neglect bearing acceleration data. As additional measurement legs become available, a drop-add scheme is employed so that only the two most recent legs are utilized in the computation of new time updated estimates. The existing procedures do not allow for estimate refinement via utilization of data from discarded measurement legs and/or bearing acceleration, even though both sources usually contain valuable information about the new target range. In essence, the concept of reducing estimation error by expansion of the data measurement set is not exploited. The foregoing deficiencies typically degrade the performance of conventional Ekelund ranging procedures and results in sub-optimal estimation.

Recursive method for target motion analysis

The United States Of America as represented by the Secretary of the Navy


This invention relates to a method of and system for facilitating detection of a particular predetermined gas in a scene under observation. The gas in the scene is typically associated with a gas leak in equipment. To this end, the system comprises an infrared camera arrangement; a strobing illuminator device having a strobing frequency matched to a frame rate of the camera; and a processing arrangement. The processing arrangement is configured to store a prior frame obtained via the infrared camera arrangement; and compare a current frame with the stored prior frame and generate an output signal in response to said comparison. The system also comprises a display device configured to display an output image based at least on the output signal generated by the processing arrangement so as to facilitate detection of the particular predetermined gas, in use.

In various industries, undesirable gas leaks from equipment, for example, equipment in power distribution systems, are undesirable for various reasons, for example, safety, environmental, operational requirements, and the like. In view of environmental reasons, environmental legislation in countries worldwide impose stricter stances on spillages and pollution of hazardous and greenhouse gases. It is thus desirable to be able to detect a gas leak and pinpoint exactly the location of the gas leaks so that suitable repair protocols are deployed to address the leak. For example, in the case of SF6 that is used in electrical installation, a loss of gas not only causes environmental harm but also may lead to malfunctioning of the installation. A problem in detecting leaks is encountered when gas leaks (e.g., colourless gas) are against ambient backgrounds as they are imperceptible to the human eye. These leaks often go unnoticed with undesirable outcomes.
One way of detecting such gas leaks quickly, particularly at long stand-off distances, in varying ambient backgrounds, for example, in such as electrical, chemical, and petrochemical industries, is an Optical Gas Imaging (OGI) technique. The OGI technique makes use of a gas detection camera operating at a selected wavelength so as to visualise any gas leaks. In this way, gas leaks may be easily detected and the necessary steps be taken to repair equipment associated with such leaks.
Some gas detection cameras currently in the market have means of detecting gas leaks by way of so called 'passive' gas detection technology. This technology employed a cooled detector and a cooled bandpass filter in order for the camera to detect said leaks.
Other cameras such as those of the type descried in U.S. Pat. No. 5,001,345 use infrared laser-illuminated imaging for the visualization of gas plumes. In this prior art document, a laser that is constantly ON is employed to supply photons to an item (e.g., a pipe) under test being supplied with a preheated test gas such as SF6. Images from narrow and wideband filters are then compared in order to detect gas leaks.
Some cameras such as those of the type described in US2015/0369730 make use of active illumination and passive gas detection technologies so as to be able to visualize and detect gas leaks. However, the Applicant has noted difficulty in detecting gas leaks in these systems when the background radiated photons and the photon traveling through the gas cloud is very similar. Moreover, these so-called conventional active/passive systems are very slow from a processing perspective and require that the camera be kept very still as movement thereof will impact on accuracy of the detection.
In this regard, it is thus an object of the present invention to address these need/s and/or to be able to better detect gas leaks and/or detect gas leaks in a different manner.


Cryptographic methods and apparatus for payment and related transaction systems are disclosed that allow some kinds of tracing under some conditions and make substantially infeasible other kinds of tracing under other conditions. Examples include: allowing tracing if and only if agreed sets of trustees cooperate; tracing from a payment to the payer by cooperation of a set of trustees; tracing from a payment to the payer without revealing to trustees which payer is being traced or which payment; identifying all payments by a payer provided appropriate trustees cooperate; and identifying all payments by a payer under investigation without trustees learning which payer and/or which payments;. Other examples include: limiting resolution to groups of payers in tracing for statistical purposes; allowing limited different markings of payment instruments while preventing payers from learning which marking they receive; providing for recovery of lost money without compromise of unrelated transactions; allowing participants the ability to retain, not forward, and even destroy some tracing information without financial harm; providing the option of artificial increase in the computational cost of at least some tracing; and providing the option of blurry linking of payments to payers.

1. Field of the Invention
This invention relates to transaction systems, and more specifically to cryptographic protocols and other techniques for ensuring security and privacy.
2. Description of Prior Art
Reference is hereby made to the following U.S. patents by the present applicant that are included herein by reference: U.S. Pat. No. 4,759,063 "Blind signature systems"; U.S. Pat. No. 4,759,064 "Unanticipated blind signature systems"; U.S. Pat. No. 4,947,430 "Card computer moderated systems"; U.S. Pat. No. 4,949,380 "Returned-value blind signature systems"; U.S. Pat. No. 4,987,593 "One-show blind signature systems"; and U.S. Pat. No. 5,131,039 "Optionally moderated transaction systems."
Payment systems today structurally provide either substantially unlimited traceability of payments or substantial untraceability. Bank notes and checks are paper-based examples of each extreme. Most digital systems proposed to date are similarly polarized into substantially traceable and substantially untraceable.
A variety of perceived requirements are believed to suggest a need for systems that have some provisions for traceability. Examples include: blacklisting known abusers of a system; investigations related to violation of law;marking of bearer instruments given to suspected criminals; statistical analysis of aggregated consumer behavior; recovery of money in case of unanticipated loss of information; and maintenance and provision by participants in payments of comprehensive records.
On the other hand, a variety of perceived requirements are believed to suggest a need for some corresponding limitations on traceability. Examples include: preventing use of blacklisting mechanism for unauthorized blacklisting or tracing; controlling how many investigations are made and maintaining confidentiality of who is being investigated; preventing marking of money withdrawn from occurring more than to a limited extent; ensuring that statistical studies cannot determine individually identifiable data; preventing use of a recovery mechanism by parties other than the party whose data is being recovered; and allowing recipients and intermediaries in payments some control over clandestine or otherwise improper use of tracing information.


A wireless packet communication system conforming to the IEEE 802.11 standard includes a plurality of access points (APs) most of which have wired connections only for power and an ISDN telephone line. The APs communicate at 8.5 Ghz with a regional point-of-presence that is one end of a VPN through the internet to a national office. The registered users' data and control of the system including the IP assignment and SIP proxy and the control of the 802.11 communication reside in the national office. By retaining for a short period the SIP connection, IP address and key encryption information after a user has disassociated from an AP, the user can quickly reauthenticate and reassociate using the same SIP connection, IP address, and encryption key at a different AP. Voice data and computer data can both be processed through an AP by the addition on another 802.11 frame encoder/decoder.

Voice over IP (VoIP) systems are being used to, among other things, replace conventional PBX's in offices. Wireless fidelity (Wi-Fi) systems, which transmit IP data, are being deployed in office buildings and on campuses to obviate the need for a wired LAN connection for computers and other equipment that is networked, and to provide wireless telephone service (wireless VoIP) as an alternative to conventional cellular systems such as TDMA, CDMA, GSM, and 3G. At present the conventional cellular systems' coverage area is much greater than the total area covered by wireless VoIP systems for several reasons, a main reason being the relative newness of the wireless VoIP system. However, there are other problems deploying wireless VoIP systems such as battery capacity and tolerance to RF disturbances. On the other hand, Wi-Fi systems, because they transmit IP data directly between the individual computer or similar equipment (the client) and an access point (AP) provide significantly higher data rates than conventional cellular systems available today or will be available in the near future.
Mobile wireless VoIP telephones require more intensive data processing than conventional cellular telephones and therefore require more battery power and consequently more frequent battery charging or larger capacity (and heavier) batteries than conventional cellular telephones. A method to reduce the battery drain is to reduce the RE transmission signal level from the telephone. This results in smaller areas of coverage for each access point (AP)/base station than for each base station in a conventional cellular system, and consequently more base stations are required than conventional cellular base stations for a particular area. Therefore, the cost of purchasing and installing each base station is more of a critical factor in wireless VoIP systems.
While the conventional cellular systems were initially designed for roaming from one cell to another without a disturbance in the voice communication, the Wi-Fi system was initially designed for electronic equipment which can tolerate gaps in the data flow to the equipment. The most common protocol for wireless IP communication is the IEEE 802.11 standard. This standard requires termination of a first connection between a user and an AP before connection to the new AP, then reauthentication usually including encryption coordination and establishment of a new connection. This process produces gaps in the voice transmission which are noticeable to a Wi-Fi telephone user.
Therefore, it can be appreciated that a Wi-Fi system for mobile users over a wide area such as a metropolitan area that is relatively inexpensive to build, and that provides virtually uninterrupted voice transmission when a mobile telephone user is changing connections from one AP to another is highly desirable.
It is an object of the present invention to provide an AP configuration that is relatively inexpensive to build and install.
It is a further object of the invention to provide a Wi-Fi system that does not create disturbances for mobile telephone user.
It is a still further object of the invention to provide a Wi-Fi system that can be used for both voice and computer data without degrading the voice communications and that is not significantly more expensive than a voice only system.

Wireless packet communications system and method