A tapered roller bearing includes an inner ring having a large flange surface, and tapered rollers having roller large end surfaces. The large flange surface has an arithmetic mean roughness Ra of 0.1 μm≤Ra≤0.2 μm. The large flange surface further has a roughness curve skewness Rsk of −1.0≤Rsk≤−0.3, and a roughness curve kurtosis Rku of 3.0≤Rsk≤5.0. The tapered roller bearing is capable of realizing both stable rotation torque while the bearing is rotating at a low speed, and excellent resistance.

In a tapered roller bearing, the roller large end surfaces of the tapered rollers come into sliding contact with the large flange surface of the inner ring. In order to prevent seizure between the roller large end surfaces and the large flange surface due to their metal contact, the surface roughness of the large flange surface is adjusted such that a sufficient oil film is formed between the roller large end surfaces and the large flange surface.
When a tapered roller bearing is used in an automotive power transmission path, or in a device such as an industrial machine, a preload is applied to the tapered roller bearing for the purpose of improving the rigidity and rotation accuracy of the tapered roller bearing. In this case, it is necessary to determine an appropriate amount of the preload by measuring the rotation torque of the tapered roller hearing. The rotation torque is measured while rotating the tapered roller bearing at a low speed (normally 100 r/min or less), for the convenience of the step of mounting the tapered roller bearing to a device. While the tapered roller bearing is rotating at a low speed, the rotation torque of the tapered roller bearing is generated mainly by the sliding friction between the roller large end surfaces of the tapered rollers and the large flange surface of the inner ring, and is affected only to a very small degree by the rolling friction generated between the tapered rollers and the inner and outer rings. Therefore, in order to accurately measure the rotation torque of the tapered roller bearing, it is necessary to fully break in the tapered roller bearing at a low rotation speed, while applying a preload to the tapered roller bearing until the roller large end surfaces of the tapered rollers come into contact with the large flange surface of the inner ring (i.e., until the width dimension of the bearing is stabilized).
Japanese Unexamined Patent Application Publication No. 2000-170774 (especially paragraphs [0021] to [0023] of the specification) discloses a tapered roller bearing in which the surface roughness Ra of the large flange surface of the inner ring is set within the range of 0.05 to 0.20 μm so as to maintain appropriate lubrication condition between the large flange surface of the inner ring and the roller large end surfaces of the tapered rollers.
That is, if the surface roughness a of the large flange surface is less than 0.05 μm, when the tapered roller bearing is broken in, the lubrication condition between the large flange surface of the inner ring and the roller large end surfaces of the tapered rollers becomes mixed lubrication which is a mixed state of fluid lubrication and boundary lubrication. As a result thereof, the friction coefficient fluctuates to a large degree, and thus the measured rotation torque also fluctuates to a large degree, thereby making it difficult to accurately manage the preload, in contrast thereto, if the surface roughness Ra of the large flange surface is 0.05 μm or more, the lubrication condition between the large flange surface and the roller large end surfaces becomes boundary lubrication. As a result thereof, the friction coefficient is stabilized, thereby making it possible to accurately manage the preload. While the bearing is rotating at a normal speed exceeding 100 (r/min), a sufficient oil film is formed between the large flange surface and the roller large end surfaces, so that the lubrication condition between the large flange surface and the roller large end surfaces becomes fluid lubrication, and thus the friction coefficient is small. If the surface roughness Ra of the large flange surface is more than 0.20 μm, when the temperature of the bearing rises in the high-speed rotation range, and the viscosity of lubricating oil decreases, an oil film having a sufficient thickness is not formed between the large flange surface and the roller large end surfaces. This may generate seizure between the roller large end surfaces and the large flange surface.
Japanese Unexamined Patent Application Publication No. 2002-139055 (especially paragraph [0021] of the specification) discloses a tapered roller bearing in which the surface roughness Ra of each of the roller large end surfaces of the tapered rollers is set to be 0.1 μm or less, and the surface roughness Ra of the large flange surface of the inner ring is set to be 0.2 μm or less, thereby improving the stability of rotation torque when the bearing is broken in.
In each of the tapered roller bearings of JP 2000-170774 and JP 2002-139055, the surface roughness Ra of the large flange surface of the inner ring is set within the above predetermined range so as to stabilize rotation torque while the bearing is rotating at a low speed with a preload applied to the bearing. However, the above predetermined range covers the roughness level of superfinishing (e.g., Ra=0.08 or less), which may destabilize rotation torque.
If the surface roughness Ra of the large flange surface of the inner ring is larger than the roughness level of superfinishing, it is possible to stabilize rotation torque while the bearing is rotating at a low speed. However, the seizure resistance in this case is inferior compared to when the surface roughness Ra of the large flange surface covers the roughness level of superfinishing.
Thus, simply by setting the surface roughness Ra of the large flange surface, it is difficult to realize both stable rotation torque while the bearing is rotating at a low speed, and excellent seizure resistance between the large flange surface and the roller large end surfaces.
In view of the above background, it is an object of the present invention to provide a tapered roller bearing capable of realizing both stable rotation torque while the bearing is rotating at a low speed, and excellent seizure resistance between the large flange surface and the roller large end surfaces.


An evapotranspiration (ET) unit includes a first communication link, a processor and a second communication link. The first communication link receives actual ET data from a plurality of environmental sensors. The processor calculates changes to a set of watering schedules of a predetermined watering program of a separate irrigation controller based on the actual ET data. The changes can increase or decrease the frequency and/or length of ON times for selected stations. The second communication link transmits the changes to the irrigation controller.

In many parts of the world due to inadequate rainfall it is necessary at certain times during the year to artificially water turf and landscaping. An ideal irrigation system for turf and landscaping should utilize a minimum number of valves, supply lines and sprinklers. Preferably the valves should be turned ON and OFF by an inexpensive, yet reliable electronic irrigation controller that is easy to program and can carry out a wide variety of watering schedules. The goal is to uniformly distribute the optimum amount of water over a given area. The type, placement and flow rates for each of the sprinklers are pre-selected when an irrigation system is designed and/or installed.
Residential and commercial irrigation systems typically include one or more solenoid actuated valves that are turned ON and OFF by the electronic irrigation controller. The valves admit water to various subterranean branch lines usually made of PVC pipe that typically have several sprinklers connected to risers coupled to the branch lines at spaced intervals. Each combination of a solenoid valve and its associated sprinklers is referred to in the irrigation industry as a station or zone. A modern electronic irrigation controller typically includes a microprocessor that executes one or more watering programs. Typically the watering programs can be pre-programmed by the user via push button and/or rotary controls. The watering programs contain one or more watering schedules which consist of run and cycle times for each station. The controller usually has an LCD or other display to facilitate programming by the user. Often the controller will revert to a default watering program in the case of a power failure. The microprocessor actuates the solenoid valves via suitable drivers and switching devices. The valves are opened and closed by the microprocessor in accordance with the pre-programmed run and cycle times for each of the stations.
Homeowners, conservationists and water purveyors are increasingly interested in minimizing the amount of water used for irrigation, especially in areas like the Southwest where water is in short supply. Some municipalities have enacted restrictions on residential and commercial watering. While such restrictions do save water, they are often arbitrary and do not take into account the watering needs of different types of vegetation in different geographic locations. Techniques have been developed for tailoring watering schedules in an electronic irrigation controller to accommodate different kinds ofplants and atmospheric conditions based on evapotranspiration (ET) rate. This is a number that represents the amount of water lost by a plant via evaporation in the surrounding soil, as well as the amount of water lost by the plant through transpiration, i.e. loss of water through its leaves or foliage. See for example U.S. Pat. No. 5,097,861 granted Mar. 24, 1992 to Hopkins et al. and assigned to Hunter Industries, Inc. of San Marcos, Calif., which discloses a controller that utilizes stored historic ET data for each zip code, along with other stored data, to calculate watering schedules.
Irrigation controllers that have the internal capability of calculating their watering schedules based on ET rates are typically complicated to use and expensive to buy. Separate after-market ET units which "piggy back" onto a base controller with no internal ET capability have limited utility because they can only reduce the existing watering schedules in the base controller.

Evapotranspiration unit for re-programming an irrigation controller


A lighting device for dielectric barrier discharge lamp according to the embodiment of the present invention includes a pulse number judging circuit 16. The judging circuit 16 is supplied with a dimming control signal LCS designating a dimming ratio of a discharge lamp as an input signals and judges a number of the drive signal pulses per unit time corresponding to the dimming ratio from the dimming control signal LCS. The judging circuit 16 then outputs the result as the pulse number setting signal. The lighting device includes a drive signal generating signal 18, which is supplied with the pulse number setting signal and outputs the drive signal pulse of the prescribed number of pulse per unit time designated by the number of the pulse setting signal. The lighting device further includes an inverter circuit 10, which is supplied with the output of the drive signal generating circuit 18 and generates HF pulse for driving the dielectric barrier discharge type fluorescent lamp.

The present invention relates to a back light source for liquid crystal display device used for personal computers and car navigation systems, and particularly to a lighting device for dielectric barrier discharge lamp suited for the back light source.
Conventionally, cold cathode fluorescent lamps enclosed with mercury have been used for back light sources for liquid crystal display device. FIG. 1 shows a waveform for driving a lamp, i.e. a lamp voltage waveform and a current waveform of a cold cathode fluorescent lamp enclosed with mercury operated under a low dimming control ratio (1%). In case of the fluorescent lamp enclosed with mercury, the waveforms of the lamp voltage and the current are generated in a period W corresponding to the dimming control ratio of 1%, using signals of high level (H) period of dimming control signal LCS corresponding to the dimming control ratio of 1% as shown in FIG. 1. In case of the fluorescent lamps enclosed with mercury, even if initial waveform distortion or residual waveform existed a little in the vicinity of the period W, the lamp light did not show flickering. This is because mercury is lighter than xenon in weight and it can move freely inside the glass tube in wide range. As a result, if a lamp voltage having a little distorted waveform is supplied to a fluorescent lamp enclosed with mercury, a phenomenon of the flickering of the lamp hardly took place because ultraviolet ray emitted from mercury atom diffuses widely.
Because mercury has a very high conversion efficiency of light compared with rare gas such as xenon, there is an advantage that enclosing a minute amount of mercury in the glass tube is sufficient.
However, in recent years, a dielectric barrier discharge type cold cathode fluorescent lamp using rare gas with no mercury contained, which is a hazardous substance, has been developed. One example of the lighting device for lighting such rare gas fluorescent lamps is explained using FIG. 2 to FIG. 8.
FIG. 2 and FIG. 3 are a side view and a longitudinal sectional view respectively showing a construction of an external electrode type fluorescent lamp which is a type of dielectric barrier discharge lamp. The external electrode type fluorescent lamp 11 is provided with a glass tube 1, inside which a discharge medium containing at least xenon is enclosed, and on an inner wall of which a phosphor 2 is provided. On at least one end of the glass tube 1, an inner electrode 4 is sealed with a lead-in wire 3 being connected. Around an outer surface of the glass tube 1, an electrically conductive wire is wound spirally as an external electrode 5. The external electrode 5 is coated with a translucent heat shrinkage tube 6 and is fixed on the outer surface of the glass tube 1. The inner electrode 4 is connected with a power supply wire 8 through a lead-in wire 3, and the external electrode 5 is connected with a power supply wire 8′ through a fixing metal bar 7. The external electrode type fluorescent lamp 11 starts discharging, when it is supplied high frequency pulses alternating between positive and negative voltages, which is applied between the inner electrode 4 and the external electrode 5 from an HF power source device 9 through power supply wires 8, 8′. The HF power source device 9 is composed of inverters, for example. Thus the external electrode type fluorescent lamp 11 emits an ultraviolet ray from xenon. The ultraviolet ray is then converted into a visible light by phosphor 2 and is used as a light source.
FIG. 4 and FIG. 5 are block diagrams showing a circuit configuration of the HF power source device 9 for lighting the external electrode type fluorescent lamp 11. The HF power source device 9 includes an inverter circuit 10, which converts a DC voltage into an AC pulse signal. In the inverter circuit 10, the external electrode type fluorescent lamp 11 is connected with the secondary coil of the transformer T1. Capacitors C1 and C2 for providing center bias are connected with one end of the primary coil. The capacitors C1 and C2 are connected in series between a DC source Vcc and a ground (GND), and the connecting point of the capacitors C1 and C2 is connected with the end of the primary coil of the transformer T1. Semiconductor switching elements S1 AND S2 and circuit elements Z1, Z2 are connected in series also between the DC source Vcc and the GND. Another end of the primary coil of the transformer T1 is connected with the connecting point of circuit elements Z1 and Z2. The circuit elements Z1 and Z2 are composed of coils, diodes, and some other elements having resistance components such as resistors or group of elements formed by combining them.
The semiconductor switching elements S1 and S2 are supplied with driving signals P1 and P2 produced by a drive signal generating circuit 12 through dimming control circuit 13, thereby performing respectively the switching control by these driving signals. The drive signals P1 and P2 have phases different from each other by 180° and have an equal repetition cycle t. The dimming control circuit 13 is a gate circuit which controls the number of drive signals P1 and P2 passing through it in a time period T defined by the dimming control signal LCS. When drive signals P1 and P2 are supplied to semiconductor switching elements S1 and S2, the semiconductor switching element S1 is turned OFF and the semiconductor switching element S2 is turned ON. Then, positive lamp current IA flows along a pass shown by a dotted line in FIG. 4. In the next cycle of the drive signals P1 and P2, the semiconductor switch S1 is turned OFF and the semiconductor switch S2 is turned ON. Then, negative lamp current IB flows along a pass shown by a dotted line in FIG. 5.
That is, when the voltage at the primary coil of the lamp drive transformer T1 is changed in a manner as L→H→L→H→L→H . . . , in accordance with the ON period of the drive signal P1, and drive signal P2, positive and negative lamp current are supplied to the external electrode type fluorescent lamp 11 connected with the secondary coil of the transformer T1, thereby lighting the fluorescent lamp 11 as shown in the timing chart of FIG. 6 and FIG. 7. By repeating the operations, a square wave voltage is supplied to the lamp 11 continuously. As a result, positive and negative lamp currents are applied continuously to the external electrode type fluorescent lamp 11 using the rare gas, thereby achieving the lighting of the lamp with high luminance.
Here, generally, the lighting device is provided with a dimming control device which controls the luminance of the lamp according with the surrounding area. The luminance of a lamp adjusted by the dimming control device is indicated by a dimming control ratio. The dimming control ratio is indicated by an arbitrary luminance to the maximum luminance of the lamp in %.
The dimming control signal 14 shown in FIG. 4 and FIG. 5 is a so called pulse width modulation signal in which a pulse width is changed in according with the dimming control ratio. In control circuit 13, switches S3 and S4 are closed only in H (high) voltage period of the dimming control signal 14 and supplies drive signals P1 and P2 generated in the drive signal generating circuit 11 to the semiconductor switching elements S1 and S2. The switches S3 and S4 are opened in the L (low) voltage period and the drive signals P1 and P2 are not supplied to semiconductor switching elements S1 and S2. Here, the period of the high voltage (H) of the dimming control signal becomes maximum when the dimming control ratio is 100%, and it becomes narrow in accordance with the dimming control ratio. As a result, a different numbers of the drive pulses in a fixed period are provided as the drive pulse signals P1 and P2 from the control circuit 13 in accordance with the dimming control ratio.
Here, the conventional HF source device 9 is difficult to use in circumstance where a stable lamp operation is required, since the flickering is prominent when the barrier discharge lamp using a rare gas without containing mercury operated at a low dimming control ratio of 25% or lower. The present inventors investigated the cause of the flickering and finally found that distortions in the waveform or variation in repetition cycle of the drive signal P1 and P2 cause the phenomenon, which will be explained bellow.
FIGS. 6–8 are timing charts showing the waveforms of the lamp drive signal P1 and P2 in HF source device 9. In the figures, the timing chart shows the waveforms when the repetition frequency of the lamp drive signal P1 and P2 is 20 kHz respectively and the dimming control ratio is 2%. Here, the fact that the lamp drive frequency (=f) is 20 kHz means that the repetition cycle t of the drive signal P1 and P2 is 50 μs. Now, if an unit time is chosen as 10 ms (where the repetition cycle is 100 Hz), numbers of pulse per unit time is 200. Hereinafter, the unit time is called as the dimming control signal cycle or terminal T. That is, when the dimming control ratio is 100%, 200 pulses per 1 cycle T of the dimming control signal are repeatedly supplied to the lamp 12 at 100 Hz frequency as the drive pulse P1, P2. Therefore, when the dimming control ratio is 2.0%, 4 pulses per 1 cycle of the dimming control signal are supplied to lamp 12 at 100 Hz frequency. The drive signal P1 and P2 have phases different from each other by 180°. Thus the drive signal P1 is in H level when the drive signal P2 is in L level, and on the contrary the drive signal P1 is in L level when the drive signal P2 is in H level. However, in the waveform of the drive signal P2 shown in FIG. 6, a lack portion A-1 is generated in the first pulse waveform of the drive signal P2 in the first period T(1) of the dimming control signal. As a result, a lack portion A-2 is generated in the lamp current waveform IL1 shown in FIG. 6. Further, in the second period T(2) of the dimming control signal, a lacking portion B-1 at the last pulse waveform of the waveform of the drive signal P1 is generated, and a lacking portion B-2 is generated at the portion corresponding to the lamp current waveform IL1. Here, in this case, lacking portions A-3, B-3 are generated at the corresponding portion of the waveform of the primary coil voltage V1 of the lamp drive transformer T1.
In the timing chart of FIG. 7, it is shown that the waveforms of lamp drive signal P1 and P2 start earlier by a time period of (t+α) compared with the period t of 1 cycle of the lamp drive signal P1 and P2 in the second period of the light dimming control signal. Here, the variation α of the start timing in the second period surpasses a range of −½×t˜+½×t. As a result, both the waveforms of the voltage V1 in the primary coil of lamp drive transformer T1 and of the lamp current IL1 start earlier by the period of (t+α) in the second period of the dimming control signal.
FIG. 8 shows a timing chart, in which the phases of lamp drive signal P1 and P2 waveform themselves vary at each repetition cycle t and the variation exceeded the range of − 1/10×t˜+ 1/10×t. As a result, the primary coil voltage V1 of lamp drive transformer T1 and lamp current waveform IL1 vary at each repetition cycle t respectively, the variation exceeds the range of − 1/10×t˜+ 1/10×t.
It becomes clear that the semiconductor switching elements S1 and S2 are ON/OFF controlled by the drive signals P1 and P2 containing such waveform distortion or cycle variation of dimming control signal. As a result, the similar waveform distortion or the variation in each cycle arises in the drive voltage waveform V1 of the external electrode type fluorescent lamp 11 connected with the secondary coil of the transformer T1, thereby occurring the flickering in the luminance of lamp 11.
On the contrary, the flickering of the lamp did not occur because the light emitting principle differs from that of the external electrode type fluorescent using the rare gas and free from mercury, when the fluorescent lamp containing mercury in the discharge gases is operated by the conventional HF source device 9, even if the distortion such as lack in the lamp drive waveform or fluctuation in the cycle of dimming control signal existed in such a low dimming region as 25% or lower.
The present invention is made to solve the technical problems in the conventional lighting device mentioned above. Therefore, one of the objects of the present invention is to provide a lighting device for dielectric barrier discharge lamps, which enables a stable lamp operation without flickering in lamp luminance at a low dimming ratio, such as of 25% or lower.

Lighting device for a dielectric barrier discharge lamp


A semiconductor integrated circuit having a field effect transistor formed on a compound semiconductor is disclosed, that comprises a first power supply, a second power supply for supplying a voltage lower than a voltage that the first power supplies, and at least one virtual power supply that is not connected to the outside and that has a voltage between the voltage of the first power supply and the voltage of the second power supply, wherein the number of the virtual power supplies is designated to a value larger than the quotient of which the voltage between the first power supply and the second power supply is divided by the forward turn-on voltage of a gate electrode of the field effect transistor. In the case that a signal received from a circuit with a low voltage is connected to a circuit between any power supply, the signal is received by a directly coupled logic circuit with a depletion type field effect transistor as a drive circuit. The threshold voltage of the depletion type field effect transistor is -.DELTA.V or higher where .DELTA.V is the voltage between each power supply.

1. Field of the Invention
The present invention relates to a logic circuit, particularly to a stack structure FETs logic circuit composed of field effect transistors that operates preferably at a voltage of 1 V or more and in ultra-high speed operation.
2. Description of the Related Art
The speed of electrons in a GaAs semiconductor is faster than that in a Si semiconductor by several times. Further, since a semi-insulating substrate can be easily manufactured, the parasitic capacitance of the circuit to be integrated can be reduced. With GaAs semiconductor devices, logic operations can be performed at a high speed. Thus, GaAs semiconductor devices have been intensively researched and developed in many laboratories in the world.
Among various basic circuit models of GaAs semiconductor devices, it is said that a direct coupled FET logic (hereinafter referred to as DCFL circuit) with an enhancement type field effect transistor (hereinafter referred to as FET) is simple structure and suitable for integration. In addition, the DCFL circuit does not require a high power supply voltage. With the DCFL circuit as a basic circuit, a gate array with an integration of 100 K gates has been commercially available.
As shown in FIG. 7, in the GaAs DCFL circuit, a drain electrode of a depletion type FET 51 used as a load is connected to a power supply terminal 100. A gate electrode and a source electrode of the depletion type FET 51 are connected to an output terminal 12. A drain electrode of an enhancement type FET 52 is connected to the output terminal 12. A gate electrode of the enhancement type FET 52 is connected to an input terminal 11. A source electrode of the enhancement type FET 52 is connected to a power supply terminal 101. The FETs 51 and 52 as inverters are followed by FETs 53 and 54 as inverters. Output signals of the FETs 53 and 54 are supplied from an output terminal 17.
When a voltage that is satisfactorily higher than the voltage of the source electrode of the FET 52 is supplied to the input terminal 11, a current flows in the enhancement type FET 52. Thus, the voltage at the output terminal 12 decreases. On the other hand, when a low voltage is supplied to the input terminal 11, no current flows in the enhancement type FET 52. Thus, the voltage at the output terminal 12 is maintained at a high voltage. Further, when the voltage at the output terminal 12 is a low voltage, the voltage at the output terminal 17 is a high level. In addition, when the voltage at the output terminal 12 is a high voltage, the voltage at the output terminal 17 is a low level.
Since the DCFL circuit shown in FIG. 7 is used along with an Si bipolar ECL (Emitter Coupled FET Logic) circuit, as a power supply voltage between the power supply terminal 100 and the power supply terminal 101, a negative power supply at -5.2 V, -4.5 V, -3.3 V, or -2.0 V is used.
On the other hand, the DCFL circuit composed of a compound semiconductor can operate at a high speed with a power supply voltage that is much lower than the above-described power supply voltage. In addition, when the DCFL circuit is operated at a power supply voltage that is higher than a gate forward turn-on voltage, a current flows from a gate Schottky electrode of the FET 54 of the next stage. This current does not contribute to driving the load, but a loss power of the circuit.
As a simplest and most effective means for decreasing the power consumption of the DCFL circuit, the power supply voltage is decreased. By setting the power supply voltage to the level lower than the Schottky barrier height of the FET, the current loss can be reduced. However, in this case, since a dedicated power supply for the GaAs DCFL circuit should be newly disposed in the system, this means is not practical.
As related art references that solve such a problem of the DCFL circuit and allow the power consumption to be reduced, for example Japanese Patent Laid-Open Publication Nos. 3-19422 and 6-104734 have been disclosed. In these related art references, logic circuits of which DCFL circuits are disposed in a plurality of stacking stages have been proposed.
In the conventional vertical stacking DCFL circuit shown in FIG. 5, a virtual voltage (virtual power supply terminal) 110 that is not connected to the outside is disposed between a power supply terminal 100 and a power supply terminal 101. The power supply terminal 100 is connected to the outside of the circuit. The voltage at the power supply terminal 100 is higher than the voltage at the power supply terminal 101. By operating a DCFL circuit between the power supply terminal 100 and the virtual power supply portion 110 or a DCFL circuit between the virtual power supply portion 110 and the power supply terminal 101, a current loss is re-used. Thus, the power consumption is reduced. As the DCFL circuit, FETs 53 and 54 as inverter circuits are used as a load of the output terminal 12. FETs 55 and 56 are used as a load of a level-shifting circuit.
In the circuit shown in FIG. 5, when a signal of a logic circuit that operates between the power supply terminal 100 and the virtual voltage portion 110 (this logic circuit is referred to as high voltage logic portion) is input to a logic circuit that operates between the virtual voltage portion 110 and the power supply terminal 101 (this logic circuit is referred to as low voltage logic portion), a level shifting circuit 21 shown in FIG. 5 is required.
Referring to FIG. 5, the level shifting circuit 21 is composed of for example an enhancement type FET 64, a diode 71, and a depletion type FET 65. In this circuit, the voltage of the input signal is lowered for the forward turn-on voltage of the diode 71.
In addition, to stabilize the virtual voltage portion 110, each of the voltage between the power supply terminal 100 and the virtual voltage portion 110 and the voltage between the virtual voltage portion 110 and the power supply terminal 101 is set to a higher voltage than the gate Schottky forward turn-on voltage of the FET. Thus, when a signal is connected from the high voltage logic portion to the low voltage logic portion, at least one diode is required. Consequently, the level shifting circuit 21 should be structured so that it operates between the power supply terminal 100 and the power supply terminal 101.
Since a current always flows in the level shifting circuit under a high voltage condition, the power consumption is large. Consequently, as the number of connections from the high voltage logic portion to the low voltage logic portion increases, the power consumption increases.
This applied to signal connections from the low voltage logic portion to the high voltage logic portion. As shown in FIG. 6, a level shifting circuit 22 composed of an enhancement type FET 64, a diode 71, and a depletion type FET 65 is required. In FIG. 6, FETs 58 and 67 as inverters are used for a level-shifted load. FETs 53 and 54 as inverters are used for a load of an output terminal 12.
The level shifting circuit 22 is structured by connecting at least one diode between a load DFET circuit and a drive FET so as to prevent the output voltage of the DCFL circuit from increasing to the voltage between the power supply terminal 100 and the power supply terminal 101. The output voltage swing of the output terminal 58 is decreased for the forward turn-on voltage of the diode 71.
However, since this circuit requires a high voltage, as the number of signal connections between the high voltage logic portion and the low voltage logic portion increases, the power consumption cannot be decreased.


A tobacco container having a plastic insert body and a method of attaching the insert body are disclosed. Some embodiments disclose an insert body that is configured to accommodate dimensional variations in the tobacco container. Some embodiments disclose an insert body that is configured to decrease weight in the tobacco container.

The present application relates to containers, and more particularly to three-piece tobacco containers that include plastic insert sleeves.
Some three-piece tobacco containers include plastic insert sleeves. U.S. Pat. Nos. 8,117,807 and 7,878,324 disclose three-piece pocket size container for holding a consumer product such as a smokeless tobacco. In both disclosures the perimeter band adjoins the container base and the container cover. The disclosures illustrate various projections disposed around the perimeter band that lock the perimeter band to the cover and base.
United States Patent Application Number 2009/0014343 discloses a three-piece pocket size hybrid container for holding smokeless tobacco. The disclosure shows the inner ring coupled to the outer base housing.


The memory device comprises a cache memory indexed by the cache index and group information of the virtual address. The physical address translated from the virtual address contains primary and secondary group information. If the tag of the cache entry addressed according to the above standard by indexing of the cache memory corresponds to the physical address, indexing is carried out again using the second group information associated with the physical address (and using the cache index of the virtual address). If the tag of the cache entry thus addressed still does not correspond to the physical address, a cache miss is signaled.

1. Field of the Invention
The invention refers to a cache memory with a virtually or physically indexed and physically tagged cache memory.
2. Description of Related Art
Modern processors require cache memories to bridge the gap between fast processors and slow main memories.
In direct mapped caches (see FIGS. 6 and 7), a map function is used for computing a cache index from the physical or virtual address a, thus selecting a line of the cache. Subsequently, a is compared with the address of the storage area currently associated with this cache line (the tag of the cache entry). Equality produces a hit (and the cache line is used instead of the main memory), otherwise we get a miss.
In most cases (a mod cache size)/line size is used as a map function. In this case, the complete virtual address need not be stored in the cache, but a/cache size is sufficient.
Direct mapped caches are simpler, but lead to higher miss rates than n-way set-associative caches do. These caches consist in principle of n direct mapped cache blocks which are accordingly smaller. Additionally, it is ensured that each main memory element is contained in at most one block. Since the map function indexes n cache lines each time, a maximum of n elements with map-equivalent addresses can be contained in the cache. This n-fold associativity reduces the probability of clashes and increases the hit rate correspondingly.
Physically and virtually indexed caches are well-known. In the case of the physically indexed cache (FIG. 6), the virtual address delivered by the processor is first translated into a physical address by the translation lookaside buffer (TLB). Subsequently, the cache is addressed using the physical address.
In the case of the virtually indexed cache (FIG. 7), the cache is addressed directly using the virtual address. A translation into the corresponding physical address is done only upon cache miss. The advantage of a virtually indexed cache is higher speed since the translation step to be done by the TLB is not necessary. Its disadvantages appear in the case of synonyms (aliasing) and/or multiprocessor systems.
Though a physically indexed cache does not show these disadvantages, it requires a complete address translation step (virtual.fwdarw.physical) from the TLB prior to initiating a cache access.
The cache type favored nowadays is virtually indexed and real physically) tagged. It is as fast as a virtually indexed and virtually tagged cache, but avoids most disadvantages of the latter, in particular problems with multiprocessor systems, synonyms, sharing and coherence.
A virtually indexed and physically tagged cache enables parallel execution of TLB and cache access (see FIG. 8). The instruction pipeline of the processor is therefore shorter so that the latency of an instruction is usually reduced by one cycle and the processor's performance is increased correspondingly.
The mechanism remains simple if all address bits (i) required for cache indexing are in the area of the address offsets (address within a page). Since this address part is not modified by translating the virtual address into the physical address, the cache can be addressed (indexed) even before the TLB translation step. Only at the end of a cache access and simultaneous TLB translation step, is it checked whether the physical address associated with the cache entry (the tag) matches the physical address delivered by the TLB. For this purpose, only the high-order bits of the address which are adjacent to the index part (i) need to be compared since the cache entry indexed by (i) can only be associated with addresses having index bits of value (i). Accordingly, only the high-order bits have to be stored in the cache as tag (physical address).
An n-way set-associative cache of this type can have a maximum size of n.times.2.sup.P, where 2.sup.P is the page size. Larger caches require larger pages or higher associativity.
However, a more interesting technique is page coloring. This is a method of creating pages in the physical memory in such a way that the low-order address bits of virtual and physical page addresses are identical (see FIG. 9). Virtual page number (vpn) and cache index (i) overlap in this case. In FIG. 9, the overlapping part is represented as a black box. The corresponding part of the virtual address is called virtual color c, that of the physical address is called physical color c'. Upon color-preserving allocation, i.e., if virtual color and physical color are identical, the above mentioned size limitation n.times.2.sup.P no longer holds.
If, as shown in FIG. 10, virtual and physical color are also compared, the color bits can be omitted when storing the tag (physical address) and only the high-order bits of the physical page number (r') have to be compared with the tag.
Of course, a cache should also work in the case of an allocation which is not perfectly well-colored. If the first cache access leads therefore to a miss and if the physical color c' delivered by the TLB is different from the virtual color c, a color-corrected cache access would have to be tried (see FIG. 11). Pages colored incorrectly can therefore be used, for accessing data in such a page, however, always an additional step upon cache access would be required (see FIG. 12).
It is to be noted that badly-colored allocations cannot be avoided under certain conditions, e.g. if two virtual pages of different colors have to be mapped to the same physical page. This involves repeated color corrections, which is time-consuming and delays the cache access.
It is the object of the invention to build a cache that is virtually and/or physically indexed and physically tagged, and, even in case of badly-colored allocated pages, allows for a fast cache access and/or reduces the risk of clashes.

Cache memory indexing using virtual, primary and secondary color indexes

International Business Machines Corporation


The embodiments of the present invention provide a series of thiamine compounds having a hydrocarbon group

Alzheimer's disease (AD, commonly known as senile dementia) is a progressive neurodegenerative disease with the main clinical manifestations of cognitive and behavioral disorders; as the most common form of elderly senile dementia, AD is mainly characterized by cognitive impairment and rapid decline in memory function. Pathologically it is characterized by intracerebral β-amyloid (Aβ) deposits contributing to senile plaques, intracellular neurofibrillary tangles due to hyperphosphorylation of tau protein, impaired glucose metabolism, and neuronal/synaptic loss. Due to the long course of illness and poor self-care ability of patients, it brings serious mental stress and economic burden to the family and society. While there are no drugs capable of preventing or delaying the progression of the disease worldwide at present, and currently available drugs for treating AD only help with symptoms, and are able only to improve cognitive symptoms temporarily, and no treatment can stop or even slow the deterioration of the disease.
Studies have shown that by inhibiting the activity of glycogensynthasekinase-3 (GSK-3), benfotiamine may decrease beta-amyloid (Aβ) deposition and tau protein phosphorylation in the brain, and reduce pathological damage of alzheimer's disease. Thus, the synthetic methods and crystal forms of benfotiamine and use thereof in the treatment of Alzheimer's disease have been studied and reported successively. However, no relevant research on other phosphorthiamine compounds has been reported yet.

Thiamine compound, preparation method and pharmaceutical composition thereof

Abstract: or a substituted hydrocarbon group attached at (I), wherein the compounds have an inhibitory effect on Aβ40 and/or Aβ42.

SHANGHAI RAISING PHARMACEUTICAL CO., LTD.


A transfer tray or tube assembly 2 is formed by an upper thermoformed sheet 4 that is bonded to a lower thermoformed sheet 6. Each sheet includes protrusions that form interior walls 10 and exterior walls 12 that in turn define channels 8 in which a number of components, such as electrical connectors, can be loaded, unloaded, stored and transferred or shipped. The thermoformed sheets 4 and 6 are bonding along adjoining dual wall sections that form the interior and exterior walls 10 and 12. Discrete bonds 34 are formed at upper and lower levels along flat abutting surfaces at the tops and bottoms of staggered trapezoidal segments 18 and 20 on the top and bottom sheets. These spaced apart discrete bonds 34 reduce warping and bowing due to stressed induced by RF bonds or welds. Interior walls 10 are joined by continuous bonds 36 that are confined to the intersection of a male ridge 42 on one member with a recessed female section 38 on the other member. Ribs 40 defining the recessed female section 38 isolated stresses induced by the bond so that the sidewalls of the channels 8 are not distorted. Multiple discrete bonds, spaced apart and on different levels, and dual walls each reduce distortion of the trays 2 and of the channels or tracks.

1. Field of the Invention
This invention is related to the storage and transfer of components, such as electrical connectors, in transfer tubes, trays or containers and to the use of these containers with automated fabrication and assembly equipment.
2. Description of the Prior Art
Thermoformed tubes, trays or containers are commonly use to store and ship components and devices of different types including the storage and shipping of a large number of relatively small items in channels in a single tube, multi-tube assembly or tray. For example electrical components, such as electrical connectors, are commonly shipped in this manner. These types of containers provide a cost effective package that adequately protects these components or connectors during normal handling.
Most prior art tubes and trays of this type are disposable containers that are manufactured for the lowest possible cost. However, these containers are increasingly used as in-process packages in which various components are loaded and unloaded a number of times. For example, components packaged in these containers or trays may require several different manufacturing steps, such as molding and terminal insertion, that take place on different manufacturing lines and often at different manufacturing facilities. Testing and inspecting and other manufacturing steps must also be performed on the components. Finally the components must be shipped to a customer who in turn will assemble the components in a final or intermediate assembly. For example, it is common practice to use thermoformed tube assemblies of this type to feed electrical connectors to a manufacturing station in which the connectors are soldered to a printed circuit board.
A cost effective way of transporting or transferring these components or connectors between various manufacturing operations and to the customer is to use the same multi-tube assembly or tray and to repeatedly load and unload components and subcomponents in the same trays. If possible the tube assemblies or trays should then be re-used after the components have been unloaded for a final time. It is common for customers to ship empty containers back to the manufacture where the containers are repeatedly re-used as many times as possible.
For high volume assembly operations loading and unloading is typically performed by automatic equipment, such as robotic or pick and place equipment. Therefore the tubes or trays must be inherently robust and dimensionally stable. If the tubes or trays are susceptible to damage during use, proper alignment for loading or unloading becomes increasingly problematic. Furthermore if the single tubes or channels in multi-tube assemblies become distorted, the components may hang up in the channels resulting in incomplete loading and unloading.
Although robust construction is one consideration that is important to maintaining dimensional stability for re-usable in-process tube assemblies, fabrication considerations are also important. For example, the common way in which such tubes are fabricated is to bond two thermoformed members together. An RF welding process can be used to produce heat for bonding the thermoformed members. Although this produces a strong bond, the addition of heat also introduces stresses into the thermoformed plastic. One of the two sheets is heated more than the other during bonding, and the differential expansion induces stresses in the final product. These stresses can soon result in warping, bowing or other dimensional irregularities. The larger the tube assembly, and therefore the larger the number of components that can be stored, then the more these stresses will add up or accumulate to cause dimensional distortion that can affect the performance and reliability of these thermoformed packages
U.S. Pat. No. 5,012,925 shows one package that is formed by a thermoformed top that is permanently bonded to an extruded member to form a multi-tube assembly. Similar prior art configurations in which thermoformed top and bottom members are permanently bonded are also used for in-process packaging. These prior art thermoformed packages, however, are derived from designs where the primary purpose was a disposable rather than a re-usable package. Therefore these prior art packages lack dimensional stability because of the stresses induced in bonding and the robustness that is needed for high volume in process use. Therefore excessive manufacturing problems are caused when the components are not properly loaded or unloaded. These problems will require intervention by the operator and often result in either discarding of components in partially filled packages or in manufacturing problems in final assembly. For example if an electrical connector is not properly fed from a tube to automatic assembly equipment, the connector may not be properly inserted into the final assembly, such as a printed circuit board. In either case increased manufacturing costs or reliability problems can ensue.

Re-usable tray for electrical components


A hydromechanical torque sensor having several plenum chambers can be utilized to transmit torque between the driving and driven parts in the power train of a motor vehicle as well as to make necessary adjustments in a hydraulically adjustable transmission. To this end, the plenum chambers of the torque sensor can be connected to or sealed from each other. The torque sensor and the transmission can receive fluid from discrete sources or from a single source by way of suitable valves.

The invention relates to power trains, particularly for use in motor vehicles for transmission of torque between a prime mover (such as an internal combustion engine) and one or more wheels. More particularly, the invention relates to improvements in power trains of the type wherein the means for transmitting at least a portion of torque from the rotary output element of a prime mover to a rotary driven element (such as the output shaft of an infinitely variable transmission) comprises a torque monitoring device or sensor with a normally annular plenum chamber for oil or another suitable hydraulic fluid. Still more particularly, the invention relates to improvements in power trains wherein the torque monitoring device or torque sensor comprises at least two elements forming part of a valve and being movable relative to each other to determine that pressure which is indicative of the torque being transmittable by the torque sensor. The valve communicates with the at least one plenum chamber and the torque sensor is preferably combined or combinable with an infinitely variable transmission of the type wherein an endless flexible element is trained over a pair of adjustable pulleys or sheaves.
Torque monitoring devices or sensors of the above outlined character are disclosed, for example, in German patent No. 28 28 347 as well as in published German patent applications Nos. 40 36 683, 42 34 294, 42 01 692 and 35 38 884. The torque sensors which are disclosed in these prior Publications are designed to establish a clamping engagement between component parts of a torque transmitting apparatus in dependency upon the load or in dependency upon the transmitted torque. As a rule, such torque sensors are designed to ensure a frictional engagement between component parts which are urged against or toward each other by a force depending at least upon the transmitted loads or upon the transmitted torque, namely in such a way that the force acting to urge the component parts into frictional engagement with one another at least approximates the force which is necessary for the transmission of torque. The application of an excessive force for urging the component parts against each other results in excessive wear whereas the application of an insufficient force entails a slip and hence again excessive wear between the parts which are maintained in frictional engagement with one another.
A conventional torque monitoring device or sensor constitutes, or can be said to constitute, a valve whose operation is dependent at least upon the magnitude of transmitted torque. Those portions of the torque sensor which are located downstream of the plenum chamber are constructed and assembled to constitute the aforementioned valve and the plenum chamber receives pressurized hydraulic fluid from a suitable pump. The valve acts as a flow restrictor or throttle which seals the path for the flow of fluid from the plenum chamber so that the pressure of fluid in the plenum chamber increases in response to abrupt rises (peaks) of transmitted torque. This entails a corresponding rise of fluid pressure in the plenum chamber as well as in the cylinder chamber or chambers of one or more cylinder and piston units which are provided to adjust the inifinitely variable transmission including a pair of adjustable sheaves and an endless flexible element which is trained over and serves to transmit torque between the adjustable sheaves. A rise of pressure in the cylinder chamber or chambers brings about a corresponding increase of the clamping force between the endless flexible element and the sheave or sheaves of the transmission. In other words, the frictional engagement between the sheave or sheaves on the one hand and the flexible element on the other hand increases in response to an increase of the transmitted torque and/or in response to the development of an abrupt rise or surge of transmitted torque.
In order to adjust the flow restrictor, heretofore known torque sensors comprise discs which are provided with confronting cam faces or ramps bearing upon rolling elements which are or which can be disposed between them with a force generated by the source of pressurized hydraulic fluid. If the transmitted torque develops peaks, especially peaks which develop in the torque being transmitted from the prime mover, the discs are caused to move axially and away from each other whereby an axially movable portion reduces the effective cross-sectional area of the outlet for the flow of hydraulic fluid from the plenum chamber at a rate which is proportional to the magnitude of the peaks of transmitted torque. In addition, the discs which are provided with the aforesaid cam faces or ramps serve as a means for mechanically transmitting at least a portion of the driving torque to adjust (such as reduce) the effective cross-sectional area of the outlet from the plenum chamber as a function of the magnitude of transmitted torque and to thus properly adjust the frictional clamping force between the adjustable sheaves and the endless flexible element of the infinitely variable transmission. The flexible element can constitute a belt or a chain; at this time, it is often preferred to employ a chain. As a rule, the flow restrictor permits the flow of hydraulic fluid therethrough except under certain circumstances of use of a prior torque sensor, such as in response to the development of highly pronounced peaks of transmitted torque. It follows that the pump or another suitable source of pressurized fluid must be capable of supplying the pressure which ensures a sufficiently pronounced engagement of the ramps or cam faces on the cam discs of the torqe sensor to transmit the required torque and which is needed to ensure that the fluid leaving the plenum chamber is maintained at a requisite pressure; the latter constitutes a permanent loss in pumping capacity.
It is also known to construct a torque sensor for use in the power train of a motor vehicle in such a way that the sensor can furnish a torque- and/or load-dependent pressure as well as a pressure which is a function of the ratio of the infinitely variable transmission. This necessitates a reducion of the clamping force upon the rolling elements between the faces or ramps of the clutch discs or analogous valving elements of a previously known torque sensor as well as between the endless flexible element and the adjustable sheaves of the infinitely variable transmission, especially when the power train is set up to operate within the partial-load range. Such design of the torque sensor renders it possible to reduce to a minimum losses developing as a result of frictional clamping engagement between he flexible element and the sheaves of the transmission. Thus, and when the infinitely variable transmission is set to operate in such a way that the looped portion of the flexible element which is trained over the torque transmitting (driving) sheave is located at a minimum radial distance from the rotational axis of this sheave, i.e., when the ratio of the transmission is reduced to a minimum value, the pressure supplied by the torque sensor is or can be greater than under those circumstances when the aforementioned looped portion of the flexible element is located at maximum radial distance from the axis of the driving sheave; at such time, the ratio of the infinitely variable transmission is maintained at a maximum value. It is assumed that the magnitude of the torque under the just outlined circumstances (namely when a looped portion of the flexible element is located at a minimal or at a maximal radial distance from the driving sheave) is constant.
The incorporation of heretofore known proposals to select the pressure of hydraulic fluid by the torque sensor as a function of a plurality variable parameters including a parameter constituting the ratio of the infinitely variable transmission is very expensive and contributes to the bulk of such power trains. The reason is that the reliance upon a second parameter, particularly the ratio of the transmission, is effective or reliable only if the machining tolerances are reduced to a minimum which is the primary cause of increased cost. Moreover, it is necessary to resort to a relatively large (or extremely large) number of additional conduits, bores and/or other passages as well as to additional valves which are or which can be quite complex and expensive and occupy a substantial amount of space. Reference may be had, for example, the the aforementioned published German patent application No. 42 01 692.
The disclosure in the patent application titled: "Power Train", Ser. No. 08/572,538, filed Dec. 14, 1995, inventor: Oswald Friedmann is hereby incorporated herein by this reference; and the disclosure in the patent application titled: "Power Train with Infinitely Variable Ratio Transmission", Ser. No. 08/772,536, filed Dec. 14, 1995, inventors: Oswald Friedmann, Urban Panther and Ivo Agner, is also hereby incorporated herein by this reference.


A modified surge protector is provided including a housing having a pair of male contacts for being inserted into a power receptacle to receive power therefrom. Associated therewith is a pair of female contacts for releasably receiving a plug of an appliance to supply power thereto. Also included is a power switch connected between the male contacts and the female contacts for allowing the flow of power therebetween only during the receipt of an activation signal. A power variation sensor is connected to the male contacts for detecting a variation in power received therefrom. A delay is included for generating a delay of a predetermined amount of time, wherein the activation signal ceases during the delay of the predetermined amount of time.

1. Field of the Invention
The present invention relates to surge protectors and more particularly pertains to a new modified surge protector for providing a resetable surge protector with an automatic delayed reset upon the loss of power from an associated power receptacle.
2. Description of the Prior Art
The use of surge protectors is known in the prior art. More specifically, surge protectors heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art surge protectors and the like include U.S. Pat. No. 5,153,806; U.S. Pat. No. 4,794,485; U.S. Pat. No. 4,947,281; U.S. Pat. No. 3,124,738; U.S. Pat. Des. No. 325,370; and U.S. Pat. No. 3,246,296 which are each incorporated herein by reference.
In these respects, the modified surge protector according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a resetable surge protector with an automatic delayed reset upon the loss of power from an associated receptacle.


The present invention provides a locking mechanism in a mobile terminal and a method of manufacturing the same. The locking mechanism comprises a slider, latch, button, and spring. The slider and latch include openings and may translate between a locked position and an unlocked position. The latch may include a protrusion that limits the translation of the slider and the latch when in the locked position. The button is located within the opening of the slider and the opening of the latch, and the spring member is fixed adjacent the latch. In an instance in which an external force is applied to the button, the external force deforms the spring member such that contact between a vertical edge of the protrusion and the spring is precluded allowing translation of the slider and the latch between the locked position and the unlocked position.

Mobile terminal devices (e.g., mobile phone, tablet, Personal Digital Assistant (PDA), and remote controller) are more and more into people's work and life to provide much more conveniences for people's work and life. At present, most of the mobile terminals need a battery to power them.
Generally, Industry Mobile Terminal's battery is hard to remove, especially to those need water proof by sealing O-ring, if the battery is too easy to remove, it will easy fail in a drop test.
However, in industrial application, usually the battery may need to be replaced frequently in the field, so we need to design a battery cover locking mechanism which is easy to unlock but could survive the drop test.

Locking mechanism of a mobile terminal battery cover


A coated implantable medical device 10 includes a structure 12 adapted for introduction into the vascular system, esophagus, trachea, colon, biliary tract, or urinary tract; at least one coating layer 16 posited on one surface of the structure; and at least one layer 18 of a bioactive material posited on at least a portion of the coating layer 16, wherein the coating layer 16 provides for the controlled release of the bioactive material from the coating layer. In addition, at least one porous layer 20 can be posited over the bioactive material layer 18, wherein the porous layer includes a polymer and provides for the controlled release of the bioactive material therethrough. Preferably, the structure 12 is a coronary stent. The porous layer 20 includes a polymer applied preferably by vapor or plasma deposition and provides for a controlled release of the bioactive material. It is particularly preferred that the polymer is a polyamide, parylene or a parylene derivative, which is deposited without solvents, heat or catalysts, and merely by condensation of a monomer vapor.

It has become common to treat a variety of medical conditions by introducing an implantable medical device partly or completely into the esophagus, trachea, colon, biliary tract, urinary tract, vascular system or other location within a human or veterinary patient. For example, many treatments of the vascular system entail the introduction of a device such as a stent, a catheter, a balloon, a wire guide, a cannula, or the like. However, when such a device is introduced into and manipulated through the vascular system, the blood vessel walls can be disturbed or injured. Clot formation or thrombosis often results at the injured site, causing stenosis or occlusion of the blood vessel. Moreover, if the medical device is left within the patient for an extended period of time, thrombus often forms on the device itself, again causing stenosis or occlusion. As a result, the patient is placed at risk of a variety of complications, including heart attack, pulmonary embolism, and stroke. Thus, the use of such a medical device can entail the risk of precisely the problems that its use was intended to ameliorate.
Another way in which blood vessels undergo stenosis is through disease. Probably the most common disease causing stenosis of blood vessels is atherosclerosis. Atherosclerosis is a condition which commonly affects the coronary arteries, the aorta, the iliofemoral arteries and the carotid arteries. Atherosclerotic plaques of lipids, fibroblasts, and fibrin proliferate and cause obstruction of an artery or arteries. As the obstruction increases, a critical level of stenosis is reached, to the point where the flow of blood past the obstruction is insufficient to meet the metabolic needs of the tissue distal to (downstream of) the obstruction. The result is ischemia.
Many medical devices and therapeutic methods are known for the treatment of atherosclerotic disease. One particularly useful therapy for certain atherosclerotic lesions is percutaneous transluminal angioplasty (PTA). During PTA, a balloon-tipped catheter is inserted in a patient's artery, the balloon being deflated. The tip of the catheter is advanced to the site of the atherosclerotic plaque to be dilated. The balloon is placed within or across the stenotic segment of the artery, and then inflated. Inflation of the balloon "cracks" the atherosclerotic plaque and expands the vessel, thereby relieving the stenosis, at least in part.
While PTA presently enjoys wide use, it suffers from two major problems. First, the blood vessel may suffer acute occlusion immediately after or within the initial hours after the dilation procedure. Such occlusion is referred to as "abrupt closure." Abrupt closure occurs in perhaps five percent or so of the cases in which PTA is employed, and can result in myocardial infarction and death if blood flow is not restored promptly. The primary mechanisms of abrupt closures are believed to be elastic recoil, arterial dissection and/or thrombosis. It has been postulated that the delivery of an appropriate agent (such as an antithrombic) directly into the arterial wall at the time of angioplasty could reduce the incidence of thrombotic acute closure, but the results of attempts to do so have been mixed.
A second major problem encountered in PTA is the re-narrowing of an artery after an initially successful angioplasty. This re-narrowing is referred to as "restenosis" and typically occurs within the first six months after angioplasty. Restenosis is believed to arise through the proliferation and migration of cellular components from the arterial wall, as well as through geometric changes in the arterial wall referred to as "remodeling." It has similarly been postulated that the delivery of appropriate agents directly into the arterial wall could interrupt the cellular and/or remodeling events leading to restenosis. However, like the attempts to prevent thrombotic acute closure, the results of attempts to prevent restenosis in this manner have been mixed.
Non-atherosclerotic vascular stenosis may also be treated by PTA. For example, Takayasu arteritis or neurofibromatosis may cause stenosis by fibrotic thickening of the arterial wall. Restenosis of these lesions occurs at a high rate following angioplasty, however, due to the fibrotic nature of the diseases. Medical therapies to treat or obviate them have been similarly disappointing.
A device such as an intravascular stent can be a useful adjunct to PTA, particularly in the case of either acute or threatened closure after angioplasty. The stent is placed in the dilated segment of the artery to mechanically prevent abrupt closure and restenosis. Unfortunately, even when the implantation of the stent is accompanied by aggressive and precise antiplatelet and anticoagulation therapy (typically by systemic administration), the incidence of thrombotic vessel closure or other thrombotic complication remains significant, and the prevention of restenosis is not as successful as desired. Furthermore, an undesirable side effect of the systemic antiplatelet and anticoagulation therapy is an increased incidence of bleeding complications, most often at the percutaneous entry site.
Other conditions and diseases are treatable with stents, catheters, cannulae and other devices inserted into the esophagus, trachea, colon, biliary tract, urinary tract and other locations in the body, or with orthopedic devices, implants, or replacements. It would be desirable to develop devices and methods for reliably delivering suitable agents, drugs or bioactive materials directly into a body portion during or following a medical procedure, so as to treat or prevent such conditions and diseases, for example, to prevent abrupt closure and/or restenosis of a body portion such as a passage, lumen or blood vessel. As a particular example, it would be desirable to have devices and methods which can deliver an antithrombic or other medication to the region of a blood vessel which has been treated by PTA, or by another interventional technique such as atherectomy, laser ablation, or the like. It would also be desirable that such devices would deliver their agents over both the short term (that is, the initial hours and days after treatment) and the long term (the weeks and months after treatment). It would also be desirable to provide precise control over the delivery rate for the agents, drugs or bioactive materials, and to limit systemic exposure to them. This would be particularly advantageous in therapies involving the delivery of a chemotherapeutic agent to a particular organ or site through an intravenous catheter (which itself has the advantage of reducing the amount of agent needed for successful treatment), by preventing stenosis both along the catheter and at the catheter tip. A wide variety of other therapies could be similarly improved. Of course, it would also be desirable to avoid degradation of the agent, drug or bioactive material during its incorporation on or into any such device.


Paper mill sludge is reclaimed and useful products produced therefrom. A predetermined amount of paper mill sludge is continuously discharged from a storage reservoir onto a mixer/conveyor to create a first reactant stream. A predetermined amount of calcium oxide is input into the first reactant stream from a calcium oxide reservoir. The calcium oxide and paper mill sludge are mixed as they travel along the mixer/conveyor to form a first intermediate mixture. After a time period sufficient to allow for the reaction of the calcium oxide and paper mill sludge, a predetermined amount of diatomite is added to the reactant stream from a diatomite storage reservoir. The first reactant stream, now comprising the first intermediate mixture of paper mill sludge and calcium oxide combined with diatomite, forms a useful, environmentally safe product.

1. Technical Field
This invention relates generally to an apparatus and process for reclaiming paper mill sludge and to useful products derived therefrom, and, more specifically, to a safe, energy efficient, fully integrated system for recycling paper mill sludge to obtain a wide variety of ecologically safe products.
2. Background
It is well known that waste cellulosic fiber and paper mill sludge, which are produced in large quantities in most industrial nations of the world today due to the large usage of paper, constitute one of our most serious environmental problems. Paper mill sludge has substantially little usage as a material that can be employed in other industrial applications. Because of its non-utility, the paper mill sludge is merely discarded, along with other waste cellulosic fiber. This creates a tremendous disposal problem as paper mill sludge contains many environmental contaminants.
In U.S. Pat. No. 5,505,774 this inventor disclosed a continuous flow process for treating paper mill sludge utilizing calcium oxide and silica. In this process calcium oxide and silica were simultaneously and continuously discharged along with a paper mill sludge slurry into a primary blender, where the components were blended.
This inventor also has utilized calcium oxide and silica in methods of treating waste cellulosic fibrous material to obtain useful products such as animal waste absorbent materials, soil supplements and floor dry materials.
In U.S. Pat. No. 5,372,314 a method of manufacturing animal bedding material is disclosed. In this process waste cellulosic fibrous material is finely shredded after which any metal component is removed. The shredded fibrous material is then mixed with calcium oxide and water until a temperature of about 120-140.degree. F. is achieved. This mixture is then neutralized with silica diatomite plankton or non-swelling clay to obtain a final mixture. The end product is especially useful as cat litter.
The process of U.S. Pat. No. 5,456,737, a continuation-in-part of the '314 patent, involves shredding and demetalling waste cellulosic fibrous material and then thoroughly mixing the fibrous material with an agricultural wetting agent and a milk of lime. Similar to the '314 process, this mixture is then neutralized with silica diatomite plankton or non-swelling clay to obtain a final mixture.
U.S. Pat. No. 5,510,310, also a continuation-in-part of the '314 patent, relates to a method for manufacturing a floor dry material from shredded and demetalled fibrous material. The fibrous material is mixed with a biodegradable surfactant, calcium oxide and water, after which a citric based solvent degreaser and silica diatomite plankton or non-swelling clay are added.
U.S. Pat. Nos. 5,372,314; 5,456,737; 5,505,774 and 5,510,310 are incorporated herein by reference.
While the above referenced methods of reclaiming or recycling paper mill sludge and waste cellulosic fibrous material provide safe and useful end products, there exists a need for an integrated process from which a single source of paper mill sludge can be utilized in an economical, safe (explosion resistant) continuous flow procedure to output environmentally acceptable products for different end-use applications. This need has not been fulfilled by others who have utilized paper mill sludge or waste cellulosic fibrous materials to form agglomerated cellulosic particles.
In particular, U.S. Pat. No. 4,799,961 to Friberg discloses the use of pulped paper or waste material from paper mills as part of a process for forming cementitious fiber impregnated construction compositions. But the Friberg process has certain limitations that make its commercial application of questionable feasibility.
U.S. Pat. No. 4,621,011 discloses a cellulosic particle manufactured by agglomerating a fibrous cellulosic feed material in the presence of water, compacting the surface of the agglomerated particles, and drying the particles.
U.S. Pat. No. 5,019,564 provides an agricultural granule for carrying and releasing an incorporated biocidal or nutritional agricultural chemical. The granule is formed by the agitative agglomeration of a plant fiber slurry, such as primary de-inked paper sludge.
U.S. Pat. Nos. 4,621,011, 4,799,961 and 5,019,564 are incorporated herein by reference. None of these patents, however, provides an integrated process for reclaiming paper mill sludge and none addresses the treatment of paper mill sludge or waste cellulosic materials to ensure that the resulting end product is substantially free of environmentally deleterious materials.
Thus, the object of the present invention is to provide such an integrated system for reclaiming paper mill sludge and waste cellulosic fibrous material such that a variety of useful, environmentally safe products can be manufactured in a continuous flow procedure.
It is a further object of the present invention that the continuous flow procedure be safe to operate and explosion resistant.

Apparatus and integrated process for reclaiming paper mill sludge and producing useful products therefrom


A load drive control apparatus comprises a drive control circuit and a mode switchover circuit. The drive control circuit, which operates under a driving power, for driving/controlling a load on a control signal. The drive/control of the load includes an overheat protection control with a hysteresis characteristic carried out on a temperature of a component of the drive control circuit and/or the load. The overheat protection control involves a drive-limiting operation to stop a drive of the load. The mode switchover circuit switches over the drive control circuit between a normal mode and a stand-by mode responsively to the control signal. The stand-by mode is less in driving power consumption than the normal mode. The stop of the drive of the load is maintained during the drive-limiting operation whatever the control signal indicates, as long as the temperature is higher than a lower limit of the hysteresis characteristic.

1. The Field of the Invention
The present invention relates to an apparatus for driving and controlling a load that operates on an electric power source, and in particular, to the apparatus that has the capability of not only reducing electric power consumed by the load but also protecting an overheat occurring in the load and/or the apparatus.
2. Related Art
An apparatus for driving and controlling a load (hereafter, referred to as a "load drive control apparatus") has been used widely by various types of equipment. Such an apparatus is applied to, for example, a blower motor and a cooling fan motor, which are incorporated in an air conditioner mounted on an automobile. Both of the blower motor and cooling fan motor are loads to be driven and controlled by the load drive control apparatus.
In such a system, it is required that electric power unnecessarily consumed by the motors during their non-operating periods of time is suppressed as less as possible. To try to satisfy such a request, there is proposed a technique disclosed by a U.S. Pat. No. 6,232,758 B1. This publication teaches a load drive control apparatus that is able to switch its operations between a normal operation mode and a stand-by operation mode, without using a large-size relay and applying an on/off signal to an ignition switch.
In this load drive control apparatus, if foreign materials creep into the rotation unit of for example a blower motor, the motor's torque is sometimes forced to increase or the motor is sometimes locked. If such a situation happens in fact, current flows, in most cases, excessively through switching elements composing part of the load drive control apparatus and/or the blower motor, which results in a sharp increase in the temperature at those switching elements and/or the blower motor. Thus, it is preferable to have overheat protection/control means of limiting the motor drive on the basis of temperature detected by a temperature sensor placed at, for example, a position nearer to the switching elements.
FIGS. 1A and 1B show changes in the temperature detected from a configuration, in which both of the foregoing load drive control apparatus and the overheat protection/control means are simply combined with each other, which is in an overload operation. FIG. 1A shows changes in the temperature in cases where a transition to an overheat-protecting operation was followed by an automatic stop of a blower switch but a user kept ignoring the on-state of the blower switch. Meanwhile, FIG. 1B shows changes in the temperature in cases where, in such a case, a user who noticed the stop of the blower fan doubtfully turned off the blower switch and then turned it on again.
In FIGS. 1A and 1B, a drive command signal is a signal to command the rotation of a blower and is given by an ECU of an air conditioner when the blower switch is on. A drive signal is made into an on/off signal for the switching elements when a drive control signal performs both of the control of the number of rotations based on a drive command signal and the overheat protection control. The foregoing load drive control apparatus makes a transition from its normal operation mode to its stand-by operation mode when the blower switch was manipulated into its off-state to stop the issue of the drive command signal. In response to this transition, supplying power to the drive control circuit that is in charge of driving the switching elements is stopped as well.
In the case of FIG. 1A, since the blower switch is kept to its on-state, the normal mode continues, thus the power being supplied to the drive control circuit without rest. Hence, the drive control circuit is capable of continuously executing an overheat protection control, in which the detected temperature is subjected control that allows changes within a temperature width regulated by both a predetermined protective temperature T1 and a predetermined release temperature T2. Because there is thermal resistance between the switching sensors and the temperature sensor, a chip temperature within each switching element (that is, a junction temperature) becomes higher than a detected temperature by the temperature sensor. However, the switching elements, which were turned off once, is again subjected to its on-operation when the detected temperature reduces down to the release temperature T2, whereby the chip temperature is limited to temperature less than its guarantee temperature.
On the other hand, in the state shown in FIG. 1B, the blower switch is manually turned off at a certain timing during the overheat protection control, resulting in that the power to the drive control circuit is once shut down. Hence the drive control circuit is reset, which loses the information indicative of states of the overheat protection control carried out before the shutdown. It is therefore possible for the drive control circuit to turn on the switching elements, if the temperature detected when the re-supply of the power is started is below the protective temperature T1. However, the blower switch is manually turned on and off in sequence after the detected temperature reached the protective temperature T1, there will be caused a fear that the chip temperature is beyond a guarantee temperature of the chips (refer to a range shown by a reference "A" in FIG. 1B). The reason is that, conjointly with an overload state (for instance, a motor locked state) bringing about a sharp increase in current, the drive control circuit is obliged to turn on the switching elements that should originally be turned off due to a high detected temperature.
In order to prevent such an unwanted overheating situation, there can be provided some countermeasures, including 1) a decrease in the protective temperature T1, 2) to embed a temperature sensor within the switching elements to measure a chip temperature with precision, and 3) to dispose, into the drive control circuit, non-volatile means for maintaining information indicative of controlled states. However, the means according to 1) is disadvantageous in that unfavorable conditions, such as higher surrounding temperature, will lead to frequent stops of the blower fan under the overheat protecting operation even in the normal use, thus spoiling user's amenity. Further, means according to 2) and 3) are difficult to employ, because a greater increase in the production cost of the system is inevitable.

Load drive control apparatus with performances of power-consumption reduction and overheat protection


An apparatus for retaining and pulling line through a raceway includes a line clamp and an attachment portion. The line clamp has a wedge fitted into a channel that is adapted to retain the line between the wedge and the channel. Further, the attachment portion is attached to the wedge and connects the line clamp to an end of a fish tape.

The subject invention generally and in various embodiments relates to devices and methods for clamping one or more lines or wires.
Electricians and/or technicians are often required to install a run of one or more lines or wires (e.g., electrical or communication wire) through lengths of raceways. Raceways may include conduits, ducts and other enclosed channels. A fish tape is commonly sent through the raceway for installing the run of lines or wires. Often, a first line or wire is folded about a tab at an end of the fish tape and taped to itself on the other side where it is doubled over. Then, if necessary, additional lines or wires are taped flush along the first line or wire. The fish tape is then pulled back out of the raceway with the lines or wires attached, with the intent to install the line or wire with the fish tape being removed. This places a tremendous amount of tension on the first line or wire where additional lines or wire are attached. Often the raceway will have angled bends (e.g., 90 degree bends, etc.) and may already have runs of line or wire inside the raceway. With this tension of the first line or wire carrying the additional lines or wires and the possible obstacles, the first line or wire may often pull away from the tab of the fish tape. Further, it is sometimes a challenge to circumvent the obstacles and deviations in the raceway without having lines or wires pull away from the first line or wire due to the lack of strength in the flush securing of the additional lines or wires to the first line or wire.
In addition, a wire clamp is often used for retaining sections of drop wire being installed. The clamp is capable of attaching to a section of a length of drop wire and then attaching to a structure. A wedge wire clamp may be employed having a wire bail for connecting to the structure. In this manner, the portion of drop wire behind the clamped portion is relieved from the tension created from the hanging portion of drop wire on the opposite side of the clamp. The wire clamp often is used to retain a few wires temporarily while preventing damage to the installed wire.

BellSouth Intellectual Property Corporation


Disclosed are a catalyst complex and a method of manufacturing the same. The catalyst complex may be manufactured by uniformly depositing metal catalyst particles on pretreated support particles through an atomic layer deposition process using a fluidized-bed reactor, which may be then uniformly dispersed throughout the ionomer solution. As such, manufacturing costs may be reduced due to the use of a small amount of metal catalyst particles and the durability of an electrolyte membrane and OCV may increase. Further disclosed are a method of manufacturing the catalyst complex, an electrolyte membrane including the catalyst complex, and a method of manufacturing the electrolyte membrane.

In polymer electrolyte membrane fuel cells, a polymer electrolyte membrane plays a role in transporting oxidized protons from the anode to the cathode and preventing hydrogen from coming into contact with oxygen. Furthermore, the polymer electrolyte membrane acts as an electrical insulator between the anode and the cathode.
If the polymer membrane does not completely block gas, OCV (Open Circuit Voltage) decreases and the durability of the electrolyte membrane is deteriorated. Hydrogen passed through the polymer membrane from the anode reacts with oxygen to thus generate water (H2O), hydrogen peroxide (H2O), etc. or is discharged without reaction.
During these reactions, OCV decreases by forming a mixed potential with the reduction reaction of oxygen, which is the original reaction of the cathode. Moreover, hydrogen passed through the electrolyte membrane reacts with oxygen to thus form hydrogen peroxide or oxygen radicals, and such hydrogen peroxide or radicals attack the polymer of the electrolyte membrane, thereby degrading the membrane and consequently generating pinholes. The pinholes thus generated cause gas permeability to further increase, such that the rate of generation of hydrogen peroxide and radicals is further accelerated and the rate of degradation of the electrolyte membrane ultimately increases.

Catalyst complex for fuel cell, method of manufacturing the catalyst complex, electrolyte membrane including the catalyst complex and method of manufacturing the electrolyte membrane


A beverage making apparatus including a housing containing a water system. The water system includes a heated water reservoir and a pour-in basin for receiving water. The pour-in basin is connected to a water pump which pumps water from the basin to the heated water reservoir. Water from the heated water reservoir is moved to a spray head for dispensing to a beverage brewing substance retained in either at least one of a pod format or a cartridge format. A pair of conductance probes are contained in the fill basin to indicate the status of water in the fill basin. The brewer is designed for use with multiple beverage making substance holders so that multiple beverage substance formats can be used with the brewer.

Beverage making apparatus has been produced which include a reservoir for holding a portion of heated water. The reservoir includes an inlet into the reservoir and an outlet from the reservoir and a heating element in association with the reservoir. Water is supplied to the reservoir, heated, and then moved to a spray head for dispensing over a beverage making substance. Heated water dispensed over the beverage making substance infuses the substance and produces a beverage.
The exemplification set out herein illustrates embodiments of the disclosure that are not to be construed as limiting the scope of the disclosure in any manner. Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying at least the best mode of carrying out the disclosure as presently perceived.


An information technology (IT) infrastructure may be monitored, and the data thus collected may be used to infer problems and predict future conditions. In one embodiment, the present invention may include receiving a plurality of component metrics, each component metric related to a corresponding component of an (IT) infrastructure of an enterprise, each component being associated with one or more gross-level rules, and generating an indicator set by comparing each received component metric to relevant historical values of the component metric. In one embodiment, the present invention may also include determining that a gross-level rule is out of compliance, comparing the indicator set to one or more historical indicator sets to determine whether the indicator set resembles any of the one or more historical indicator sets, and performing an appropriate action based on the result of the comparison.

1. Field of the Invention
The present invention applies to the field of monitoring and maintaining an enterprise's information technology infrastructure and, in particular, to predicting performance irregularities in an enterprise's information technology infrastructure, and inferring possible problems causing the irregularities.
2. Description of the Related Art
Modern businesses rely on information technology (IT) to assist in carrying out business tasks. An enterprise's IT infrastructure needs to consistently perform to specification to ensure the success of the business. The IT infrastructure may be used for an enterprise's communication, database management, inventory tracking, shipment records, website management, business-to-business (B2B) ecommerce, business-to-consumer (B2C) ecommerce, accounting, billing, order tracking, customer support tracking, document management, and a possibly infinite number of other tasks. The IT infrastructure is made up of numerous components such as servers, hubs, switches, computers, the links connecting these devices, the software applications running these devices, and so on. Each of these components generally has numerous subcomponents such as a central processing unit (CPU), bus, memory, and similar high-level electrical components. The proper functioning of the IT infrastructure in large part depends on the proper functioning of these components and subcomponents.
Recognizing the importance of proper functioning, various monitoring tools have been developed to measure the performance of components and subcomponents. For example, a monitor may alter states depending on whether a computer is online or offline. If the monitor indicates the computer is offline, technicians may need to take action to put it back online, or switch to a backup computer. For relatively simple and small-scale IT infrastructures such monitoring may be adequate. However, some enterprises have IT infrastructures so large and complex that merely having information about individual components or subcomponents may not be very helpful.
For example, in a large-scale IT infrastructure that may include many servers, having a particular combination of sever failures may not cause a problem. However, if a server failure combination does cause a problem so that the enterprise's website stops functioning properly, it may not be quickly determined which server or servers of the failed servers are the critical servers causing the problem. The IT technicians receive no assistance from prior art monitors in how to prioritize technical involvement or in identifying what specific combination of components or subcomponents may be the cause of the particular problem. Furthermore, prior art monitors are incapable of predicting when problems or out-of-compliance conditions, i.e. performance irregularities may occur. Thus, IT technicians must wait until the IT infrastructure fails to function according to specification, and then they must find the cause of the failure without assistance from the monitors, other than the raw data they provide.

Predictive monitoring and problem identification in an information technology (IT) infrastructure


A rotating control device includes a bowl housing with an inner aperture to receive a seal and bearing assembly. A plurality of hydraulically-actuated fail-last-position latching assemblies are disposed about an outer surface of the bowl housing to controllably extend a plurality of piston-driven dogs radially into a groove of the seal and bearing assembly. The seal and bearing assembly includes a housing, a mandrel disposed within an inner aperture of the housing, a first interference-fit sealing element attached to a bottom distal end of the mandrel, a plurality of tapered-thrust bearings indirectly mounted to the housing, a preload spacer disposed between top and bottom tapered-thrust bearings, a plurality of jam nuts to adjust a preload of the tapered-thrust bearings and a lower seal carrier attached to the seal and bearing housing comprising a plurality of dynamic sealing elements that contact the mandrel.

In conventional drilling operations, a wellhead disposed over a wellbore includes an annular blowout preventer that is fluidly connected to a rotating control device that, with other pressure control equipment, are used to manage wellbore pressure. The drill string extends through an interior passageway of the rotating control device and the annular blowout preventer and extends into the wellbore, which may extend several thousands of feet below the Earth's surface.
In applications where wellbore pressure is managed, including, for example, managed pressure drilling, pressurized mud cap drilling, underbalanced drilling, extended reach wells, and other drilling operations, the annulus surrounding the drill string is sealed by the rotating control device and the wellbore pressure is managed through manipulation of a surface-backpressure choke manifold disposed on the rig floor. Specifically, wellbore pressure is managed by controlling the choke aperture of the surface-backpressure choke manifold fed by one or more fluid flow lines that divert returning fluids to the surface. Each choke valve of the surface-backpressure choke manifold is capable of a fully opened state where flow is unimpeded, a fully closed state where flow is stopped, and intermediate states where the valve is partially opened, thereby restricting flow and applying surface backpressure commensurate with the flow restriction. If the driller wishes to increase annular pressure, the choke aperture may be closed to the extent necessary to increase the annular pressure the desired amount. Similarly, if the driller wishes to reduce annular pressure, the choke aperture may be opened to the extent necessary to decrease the annular pressure the desired amount. In this way, wellbore pressure may be managed by controlling the surface backpressure from the platform of the drilling rig.


A modified large margin perceptron learning algorithm (LMPLA) uses asymmetric margin variables for relevant training documents (i.e., referred to as “positive examples”) and non-relevant training documents (i.e., referred to as “negative examples”) to accommodate biased training sets. In addition, positive examples are initialized to force at least one update to the initial weighting vector. A noise parameter is also introduced to force convergence of the algorithm.

Document categorization is the problem of ranking documents with respect to their relevancy to a given category. For example, email documents may be ranked with respect to their relevancy to a particular category in order to provide a user with a list of relevant emails sorted from the most relevant to the least relevant. Furthermore, the emails documents having a ranking score that exceeds a given threshold may be labeled as "relevant" to a given category. Therefore, the email documents categorized as "relevant" to the category may be automatically moved or copied to a specified folder without intervention by the user. In one approach, the available categories are derived from a training set of documents with predefined relevance tags.
The Large Margin Perceptron Learning Algorithm (LMPLA) is one such approach, which has been known since at least 1973. See R. Duda and P. Hart, "Pattern Classification and Scene Analysis", Wiley, 1973. An LMPLA is a simple algorithm for learning the parameterization of a linear classifier. That is, an LMPLA determines the weighting parameters for a linear classifier function ƒ(x)=Σiwixi that computes the relevancy of the document. The weighting parameters are determined from a training set of documents having known relevancies.
Despite its simplicity, the LMPLA is faster and less resource intensive than many more sophisticated text classifiers in use today. However, prior LMPLAs do not perform well for significantly unbalanced datasets (i.e., where the number of relevant documents is orders of magnitude larger than the number of non-relevant documents or vice versa), which is common in many real world applications. In addition, prior LMPLAs do not converge for all training sets.

Large margin perceptrons for document categorization