A ring oscillator has a multiplicity of inverters. An interconnect is connected between two of the inverters, and a storage capacitor to be measured, with its associated lead resistor, is coupled to the interconnect either via an interconnect or a transistor can selectively coupled and decouple the capacitor and the lead resistance. A measuring device is connected up to the ring oscillator and is used to determine a value for the oscillation frequency of the ring oscillator on the basis of which a value for the time constant of the storage capacitor can be determined.

The invention lies in the semiconductor technology and memory technology fields. More specifically, the invention relates to a circuit configuration and a method for determining a time constant of a storage capacitor of a memory cell of a semiconductor memory.
Semiconductor memories have memory cells each comprising, for example, a storage capacitor (or memory capacitor) and a selection transistor. The time duration for storing or for reading out an information item into the memory cell is determined, inter alia, by the time constant of the storage capacitor. The time constant thereby depends on the storage capacitance of the storage capacitor and the lead resistance of the storage capacitor. In this case, the storage capacitor may be regarded as a capacitor connected up to a resistor.
The time constant or the delay time during the signal transfer of a capacitor connected up to a resistor is referred to, by way of example, as RC time constant. Inter alia, RC time constants of a memory cell of a semiconductor memory, can be determined by means of the present invention. In order to determine for example the RC time constants of a memory cell which has a trench capacitor as storage capacitor of the memory cell, it is advantageous to configure the standard process for fabricating a DRAM as closely as possible to the fabrication process used in the product, so that the arrangement for determining the RC time constant, which arrangement is fabricated as a test structure, corresponds to a memory cell arranged in the product.
By way of example, if the RC time constant of a trench capacitor is to be determined, then the capacitance C is formed to the greatest possible extent by the capacitance of the trench capacitor. The resistance R comprises, inter alia, the resistance of the conductive trench filling of the trench capacitor and also the resistance of a buried contact formed in the trench and the resistance of a selection transistor which is connected to the trench capacitor and is switched into the on state.
In order to determine the delay time of a memory cell capacitor connected up to a resistor, it is known from the prior art, for example, that a trench capacitor which deviates greatly from the round form of a bored hole and assumes a slotted form in the substrate and thus has greatly modified geometrical forms compared with a trench capacitor used in the product in a memory cell can be used for determining a delay time. What is problematic here is that a structure which deviates very greatly from a storage capacitor used in the product is used for determining a delay time. Consequently, a product-relevant measurement of the RC time constant of the storage capacitor used in the product is not reliably possible with this structure.
It is accordingly an object of the invention to provide a circuit configuration and method for determining a time constant of a storage capacitor of a memory cell of a semiconductor memory, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is useful to determine the time constant of the storage capacitor.
With the foregoing and other objects in view there is provided, in accordance with the invention, a circuit configuration for determining a time constant of a storage capacitor of a memory cell of a semiconductor memory, comprising:
a ring oscillator, which has at least three series-connected inverters;
an interconnect, which has a first segment and a second segment and which connects up two inverters of the ring oscillator to one another;
a storage capacitor and a lead resistor, which has a first resistor terminal and a second resistor terminal, the first resistor terminal being connected to the storage capacitor and the second resistor terminal being connected to the interconnect between the first segment and the second segment;
a measuring device, which is connected up to the ring oscillator and which can be used to determine a value for the oscillation frequency of the ring oscillator, a device by which a value for the time constant of the storage capacitor can be determined on the basis of the value of the oscillation frequency.
The storage capacitor is connected via the lead resistor to the interconnect which is arranged between two inverters of the ring oscillator. This increases the total capacitance of the interconnect, as a result of which the oscillation frequency of the ring oscillator is reduced. The time constant of the storage capacitor and the lead resistor can be determined from the reduction of the oscillator frequency.
In accordance with an added feature of the invention, the measuring device comprises a frequency divider. A frequency divider has the advantage that it divides a possibly very high oscillation frequency of the ring oscillator down to a significantly lower frequency which, in a downstream circuit, on account of the lower frequency, can be determined in a simplified manner with a significantly lower outlay on apparatus.
In accordance with an additional feature of the invention, the circuit configuration further has
a second ring oscillator comprising at least three series-connected inverters to be arranged as reference resonant circuit, and
a mixer having a first mixer input, a second mixer input and a mixer output to be connected up to the ring oscillator and the second ring oscillator,
the first ring oscillator being connected to the first mixer input and the second ring oscillator being connected to the second mixer input and the mixer output being connected to the measuring device for the purpose of determining a value for the difference between a first frequency of the first ring oscillator and a second frequency of the second ring oscillator.
The mixer makes it possible to generate a signal which characterizes the difference between the frequency of the first ring oscillator and the second ring oscillator. This enables the direct determination of a differential frequency. The second ring oscillator is used as reference resonant circuit, so that it does not comprise, for example, the storage capacitors to be measured, the latter only being coupled to the interconnect in the case of the first ring oscillator.
A further refinement of the circuit configuration according to the invention provides for a transistor to be connected up in such a way that the lead resistor and the storage capacitor can be coupled to and decoupled from the interconnect by means of the transistor. The transistor enables the targeted connection of the storage capacitor to be measured, including the lead resistor. The conductivity and thus the electrical resistance of the controllable path of the transistor can be controlled via a gate terminal. If the controllable path is set such that it has a high resistance, then the storage capacitor is practically decoupled from the interconnect. By contrast, if the controllable path is set at very low impedance, then the storage capacitor is coupled to the interconnect and has an attenuating effect on the oscillation frequency of the ring oscillator.
In accordance with another feature of the invention, a multiplicity of storage capacitors of memory cells of a memory cell array of a semiconductor memory are connected up to the interconnect. This is advantageous since the storage capacitance of a storage capacitor of a semiconductor memory is usually made very small, so that the parallel coupling of a multiplicity of storage capacitors to the interconnect effects a frequency alteration of the oscillation frequency of the ring oscillator which is greater by a multiple. The frequency change of the ring oscillation which is enlarged by a multiple can be measured with lower measurement outlay, with reduced susceptibility to interference and increased precision.
A further advantageous refinement of the circuit configuration according to the invention provides for the circuit configuration to be arranged on a substrate, on which a word line for controlling the transistor and the interconnect are arranged, the word line running parallel to the interconnect at least in sections. By virtue of this routing of the interconnect to which the multiplicity of capacitors connected up to resistors is in each case connected, the time-delaying effect of the multiplicity of storage capacitors is combined with one another for influencing the oscillation frequency of a ring oscillator. By virtue of the special routing of the interconnect, a meandering structure is arranged on the substrate.
With the above and other objects in view there is also provided, in accordance with the invention, a method for determining a time constant of a storage capacitor of a memory cell of a semiconductor memory. The method has the following steps:
providing a circuit configuration which comprises a ring oscillator having at least three series-connected inverters,
which comprises an interconnect having a first segment and a second segment, the interconnect connecting up two inverters of the ring oscillator to one another,
which comprises a storage capacitor and a lead resistor, the lead resistor connecting the storage capacitor to the interconnect between the first segment and the second segment, and
which comprises a measuring device, which is connected up to the ring oscillator;
determining a value for the oscillation frequency of the ring oscillator by means of the measuring device, a value for the time constant of the storage capacitor being determined from the value for the oscillation frequency.
The method according to the invention makes it possible to determine the time constant of the storage capacitor.
A further, advantageous method step provides for
the lead resistor and the storage capacitor to be connected up to the interconnect by means of a transistor and to be able to be coupled to and decoupled from the interconnect by means of the transistor,
a first value for a first oscillation frequency of the ring oscillator being determined for the operation of the ring oscillator decoupled from the interconnect by means of the transistor, and
a second value for a second oscillation frequency of the ring oscillator being determined for the operation of the ring oscillator coupled to the interconnect by means of the transistor, and
the time constant of the storage capacitor to be determined on the basis of the first value and the second value.
A further refinement of the method according to the invention provides for
a second ring oscillator, which comprises at least three series-connected inverters to be provided as reference resonant circuit,
a mixer having a first mixer input and a second mixer input and a mixer output to be provided, the first ring oscillator being connected up to the first mixer input and the second ring oscillator being connected up to the second mixer input, and
the mixer to form a value for the difference between the first oscillation frequency of the first ring oscillation and the second oscillation frequency of the second ring oscillator and to communicate it to the measuring device, and
the time constant of the storage capacitor to be determined on the basis of the value for the difference between the frequencies.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a circuit configuration and a method for determining a time constant of a storage capacitor of a memory cell of a semiconductor memory, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Circuit configuration and method for determining a time constant of a storage capacitor of a memory cell in a semiconductor memory


In an embodiment, a novel, scene adaptive, robust shadow detection method has been disclosed. An adaptive division image analysis compares one or more images containing objects and shadows to a reference image that is void of the objects and shadows. Ratios are calculated comparing the frame with shadows and/or objects to the reference frame. Shadows are identified by identifying pixels that fall within a certain range of these ratios. In another embodiment, projection histograms are used to identify the penumbra region of shadows in the image.

video motion detection (VMD) is the backbone functionality for most Intelligent Video Surveillance (IVS) systems, and the robustness of the system is one of the primary performance criteria for an IVS system. For without a robust motion detection engine, the subsequent functionalities in an IVS system will not be accurate or reliable. One of the key factors in enhancing the robustness of dynamic video analysis is to provide an accurate and reliable means for shadow detection. For if left undetected, shadow pixels can cause problems such as object merging and object shape distortion, and may result in incorrect object tracking and classification.
Most of the shadow tracking algorithms known in the art are computationally intensive—some to the extent of equaling the computational requirements of the motion detection algorithm. Many of these known shadow detecting algorithms take into account a priori information, such as the geometry of the scene or of the moving objects, and the location of the light source. Algorithms that don't require any such a priori information exploit such things as spatial information (e.g., shadows in an image frame are attached to their respective object), transparency (i.e., a shadow always makes the region it covers darker; this involves the appearance of single pixels), and/or homogeneity (the ratio between pixels when illuminated and the same pixels under shadow is roughly linear).
One method of shadow detection known in the art computes an intensity ratio between the current image and the reference image for each pixel within the detected blobs. This method uses the characteristic that the photometric gain of a shadow with respect to the background image is less than unity and roughly constant over the whole shadow region, except at the edges (the penumbra region). In this method, a priori assumptions regarding certain shadow identification rules result in the detection only of shadows with quite a large area with respect to the object itself.
In another method of shadow detection known in the art, the shadow detection algorithm initially decomposes the difference between the background image and the current image into brightness and chromaticity components. Then, a preset threshold is applied on the separate components. This yields a pixel classification into background, shadow or foreground categories.
In another method known in the art, the method is applied to gray level images taken by a stationary camera. The method uses the property of a moving cast shadow that its illumination change (measured directly from two frames using a physics-based signal model of the appearance of a shadow) is smooth. The system prepares two distinct modules to detect penumbra and shadows separately. The first module uses a two-frame difference between subsequent frames as the input image. A linear luminance edge model is applied to detect likely shadow boundaries. Further, a Sobel operator is measured perpendicularly to the borders and the results are made to be thresholds using both a gradient outcome and an edge model. The second module computes the ratio between two subsequent images and thresholds on the local variance.
Another shadow detection approach known in the art is based on the similarity of background and shadow regions. A color segmentation method using a K means algorithm segments the pixels as a cast shadow, a self-shadow, or a dark object. This is followed by a connected component analysis to merge the similar regions. A gradient comparison between the background image and the shadow pixels gives a validation for removing the shadow.
Another shadow detection approach known in the art explores the HSV (Hue, Saturation, and intensity Values) color space. The hue, saturation & intensity values are checked individually in order to determine if the values lie between certain ranges. A shadow mask is thus formed having the values 1 or 0 based on the conditions satisfied. A difficulty with this method is in fixing the range values for H, S and V.
All of the aforementioned techniques of the prior art suffer from one or more shortcomings. Those techniques that are based on the homogeneity property of shadows assume that the ratio between pixels when illuminated and when subjected to a shadow is constant. In fact however, that ratio is highly dependent on illumination in the scene, and shadow correction therefore is not effective in these prior art systems where the ratio is assumed to be constant. Additionally, approaches that employ techniques like multi-gradient analysis to remove the penumbra region of a shadow that is left by image division analysis are computationally intensive. The art is therefore in need of an improved system and method to process shadow information in image data.


A desk chairmat includes a substantially planar member having an upper surface, a lower surface, and a peripheral edge; the planar member having at least one foot massage area in a selected part thereof; and a foot massage panel secured within the selected area, the foot massage insert having a base and a plurality of upwardly projecting foot massage nodules. The foot massage panel may also be in the form of a peel and stick pad that is adhesively secured to the upper surface of the desk chairmat.

Desk chairmats are well known in the art and typically include a substantially planar member of generally square, rectangular or other shape, with or without a lip extension portion adapted to be located in the well area of a desk. Typical chairmats for use on carpeted floors also include a plurality of spikes or cleats projecting from the lower surface of the chairmat that anchor the chairmat and prevent drifting.
Foot massage mats are also known in the art, typically including mats of rubber or plastic construction, with an array of protuberances covering substantially the entire upper surface of the mat. Examples may be found in U.S. Pat. Nos. 5,575,034; 5,158,073; and 4,329,981.
This invention advantageously combines a desk chairmat with a foot massage mat to permit persons sitting at a desk to massage the soles of the feet in, for example, an office or home office environment.
In one exemplary embodiment, the invention provides a desk chairmat that includes a planar member with four side edges and a lip extension projecting from the forward edge of the mat. The lip extension is formed with a recess, and a plurality of hard, therapeutic nodules or protuberances projecting upwardly from the base of the recess, such that the protuberances or nodules do not extend substantially above the upper surface of the remainder of the chairmat. The nodules or protuberances are preferably of part-spherical shape but may have other shapes as well.
The chairmat is preferably of unitary construction, and is preferably made of a transparent or semi-transparent PVC, polypropylene, polycarbonate, or other suitable material.
In another arrangement, one or more massage inserts may be glued or heat sealed within cavities or recesses provided in the chairmat.
Another arrangement within the scope of the invention includes stick-on massage mats that consumers can attach to existing chairmats in order to add the foot massage feature.
It should be understood that the shape of the chairmat is not limited to square or rectangular and may include round, oval or other shapes. Moreover, the foot massage area may be included in an extended lip portion of the chairmat, or in a selected area within an otherwise regular peripheral border or edge of a chairmat of any shape.
In another embodiment, the foot massage area is located in an integrally hinged forward lip portion that can be pivoted upwardly about the hinge to an angled position relative to the remainder of the mat. A heater and/or massage vibrator device may be placed behind the lip portion to support the latter in its angled position and to enhance the massage feature.
In still another embodiment, resilient support for the hinged lip portion is provided by an integral extension of the mat itself that may be folded under the lip portion.
Accordingly, in its broader aspects, the invention relates to a desk chairmat comprising a substantially planar member having an upper surface, a lower surface, and a peripheral edge; the planar member having at least one recess in a selected are thereof; and a foot massage insert secured within the recess, the foot massage insert having a base and a plurality of upwardly projecting foot massage nodules.
In another aspect, the present invention relates to a desk chairmat comprising a substantially planar member having an upper surface, a lower surface, and a peripheral edge; and at lest one stick-on foot massage pad adhered to a selected area of the upper surface, the foot massage pad comprising a thin base and a plurality of upwardly projecting nodules thereon.
In another aspect, the invention relates to a foot massage pad comprising a thin carrier layer or base having a thickness of about 0.010 to 0.075 in.; a lower surface coated with a self-stick adhesive and a peel-away paper layer applied over the adhesive; and an upper surface having a plurality of upwardly projecting foot massage nodules thereon.
In still another aspect, the invention relates to a desk chairmat comprising a substantially planar member having an upper surface, a lower surface and a peripheral edge defined by four side edges and a forward lip portion extending away from one of the four side edges, the upper surface of the forward lip portion formed with a plurality of upwardly extending foot massage nodules, and wherein the forward lip portion is connected to the one of the four side edges by an integral hinge enabling the forward lip portion to be pivoted upwardly, out of the plane of the planar member to an angled foot massage position.
Other objects and advantages of the invention will become apparent from the detailed description that follows in connection with the drawings as briefly described below.


A lamp assembly for use with a rapid start metal halide bulb, and including a lamp head housing and a power supply source. The lamp head housing includes a circuit board with power supply contact surfaces, a high voltage resistant socket, a reflector, and an on-off switch. The circuit board provides an ignition voltage, an ignition voltage spike, and a supply voltage to the rapid start metal halide bulb. The power supply contact surfaces connect power to the circuit board. The high voltage resistant socket holds the rapid start metal halide bulb and is electrically coupled with the circuit board. The reflector is arranged relative to the high voltage resistant socket, and reflects light emitted from the rapid start metal halide bulb. The on-off switch is electrically coupled with the circuit board. The power supply source provides an AC or DC power supply and is adapted to be either mechanically coupled with the lamp head housing such that its contacts contact the power supply contact surfaces of the lamp head housing or wire connected to the lamp head housing.

The present invention relates to lamps (stationary or portable) such as hand-held, land vehicle, boat, aircraft, etc., which can be supplied with power from a variety of power sources such as a power grid (i.e., an AC power supply), a renewable energy source, or a disposable energy source, for example, and which can use rapid start metal halide bulbs.
Presently, most portable lamps use conventional glow wire bulbs which are powered by disposable or rechargeable battery cells. Unfortunately, such conventional glow wire bulbs have a low power-to-light conversion efficiency (hereinafter "conversion efficiency"), i.e., electrical energy is converted more to heat than to visible light. Although the bulb's conversion efficiency can be increased by increasing the temperature of the glow wire of the bulb, such a temperature increase rapidly reduces the service life of the bulb. The service life/conversion efficiency relationship can be improved by filling the light bulb with heavy inert gases such as Krypton or Xenon. The light power of such conventional bulbs is typically between 0.7 and 5 watts.
Light bulbs filled with halogen-hydrogen (hereinafter "halogen light bulbs") are advantageous in that they can operate at higher temperatures without suffering an unacceptably low service life. This is due, at least in part, to a "recycling" of the high temperature glow-wire material. Specifically, tungsten from the glow wire deposited on the glass surface of the light bulb migrates back to the glow wire.
Two types of halogen light bulbs are presently available; namely, a longlife halogen light bulb and a high power halogen light bulb. The service life of the longlife halogen light bulbs is on the order of 2000 hours. During operation, the glow wire attains a temperature of approximately 2900.degree.-3000.degree. K. The average light conversion efficiency is 15-20 lumen per watt. The service life of high power halogen light bulbs is about 50 hours. During operation, the glow wire attains a temperature of about 3000.degree.-3300.degree. K. The average light conversion efficiency is 20-30 lumen per watt.
Unfortunately, halogen light bulbs have a number of problems which greatly limit their use in portable or hand held lamps. Specifically, halogen lamps are extremely sensitive to changing power supply voltages. For example, a voltage increase of 5% results in a 14% increase in light output, a 6% increase in conversion efficiency, but a 50% decrease in service life. Further, since resistivity of the tungsten filament decreases with temperature, if a fully charged battery is connected to a cold glow wire, the glow wire may burn off due to the high current. Moreover, at the end of the battery discharge period, the light output and the conversion efficiency are greatly reduced and the "color temperature" is degraded. Lastly, at the end of the service life of a halogen light bulb, unless an internal fuse is employed, a damaging arc can occur.
Halogen is commonly used in light bulbs having a power rating over 2.5 watts. Hand held lamps for professional use are usually equipped with halogen light bulbs rated at between 5 and 35 watts. The 35 watt limit is dictated by the heat loss (of about 28 watts) which must be removed without burning a user. Professional hand held lamps for underwater use (e.g., a diver lamp) can be equipped with bulbs up to 100 watts since the water can remove the extra heat generated. However, for example, a 100 watt lamp requires a heavy (almost 8 pounds) NiCad (Nickel Cadmium) battery for a one hour supply of light. In each of the above examples of halogen lamps, the light output is limited based on the total power rating of the lamp and the conversion efficiency of the lamp.
Metal halide light bulbs have a much higher conversion efficiency than other conventional bulbs, i.e., on the order of 70 to 90 lumen per watt. These light bulbs emit light by ionizing gases. Metal halide light bulbs are high pressure mercury vapor light bulbs filled with heavy metal halogens to improve the "color temperature" of the emitted light. Metal halide light bulbs are typically rated from 35 to 1000 watts. Unfortunately, metal halide light bulbs need from one to three minutes, from the time they are switched on, to reach their full output. Moreover, metal halide light bulbs are difficult to restart under "hot conditions" (i.e., when they have been operating) such as after a short interruption of the power supply.
The development of special metal halide light bulbs has been funded by the European Community/European Union. These special metal halide light bulbs can restart under hot conditions and which quickly attain full light output from the time they are switched on. For example, the bulbs ECE-D1, ECE-D2 or ECE-D2-S (also covered by the German Industrial Standard DIN 72601) have these characteristics. Specifically, these special metal halide light bulbs attain 15% of total output in about 0.5 seconds and full output in about 2 seconds. Their light conversion efficiency is about 85 lumen per watt. Special metal halide light bulbs with 35 to 50 watt power ratings are currently available. Unfortunately, the special metal halide lamps require special control and ignition conditions. Specifically, a voltage of 300 to 550 volts and a fast pulse of about 23 KV-30 KV are needed to ignite these lamps. Further, an operating voltage of about 65 V-120 V is needed. Currently available electronic control and ignition systems are complex and consequently, very expensive.
In the past, the operation of metal halide bulbs was electronically controlled with current control circuitry. With current control circuitry, a choke (i.e., an inductor or winding), located between a step-up converter and a switch network, supplies a rectangular AC current in conjunction with a lamp switch network. Transistors are switched in a phased mode, i.e., first on, second off. The inductive properties of the ignition transformer do not interfere with the current control circuitry. Unfortunately, the current control circuitry is very bulky, includes a high number of components, and is expensive.
In view of the above drawbacks of the prior art, a lamp (such as a portable, hand-held lamp, for example) having a high conversion efficiency, a reasonable service life, and a high light output (in lumen) is needed. The lamp must be able to reach full output in a short amount of time and must reliably restart under "hot conditions." To be commercially viable, the control and ignition systems of the lamp must be relatively inexpensive. Lastly, the lamp should be able to operate with a variety of power sources, such as a battery, a car or boat power supply, or an AC or DC power supply.

Portable lamp for use with rapid start metal halide bulbs


An apparatus is disclosed for evaluating thermal and electrical characteristics of a sample. An intensity modulated pump beam is focused onto the surface of a sample at one spot. A non-modulated probe beam is focused onto the sample at a second spot, spaced laterally and vertically from the first spot. The distance between the two spots is at least two microns. The modulated power of the reflected probe beam that is in phase with the pump beam modulation frequency is monitored to provide information about the characteristics of the sample. The apparatus is particularly useful in evaluating the integrity of metal lines and vias in a semiconductor sample.

There has been considerable interest in developing high resolution, non-destructive, non-contact techniques for evaluating samples. The need is particularly acute in the semiconductor industry where feature sizes are often in the micron and submicron range.
The assignee herein has developed one such device which is marketed under the trademark Thermaprobe Imager. The operation of this device is described in the following United States Patents which are hereby incorporated by reference: U.S. Pat. Nos. 4,521,118; 4,522,510; 4,636,088; 4,579,463; 4,854,710; 4,952,063 and 5,042,952.
All of the devices described in the above cited patents include a means for periodically exciting the sample at a highly localized spot on the sample surface. In the commercial embodiment of the device, this means is defined by an intensity modulated pump beam from an argon laser which is focused to a spot size of about one micron on the sample surface. The pump beam functions to periodically heat the sample which, in turn, generates thermal waves that propagate from the irradiated spot. In a semiconductor sample, the pump beam also functions to create an electron-hole plasma which propagates in a manner analogous to a thermal wave. Both the thermal and plasma waves interact with boundaries and barriers which scatter and reflect the waves. Features at or beneath the sample surface can be studied by monitoring the variations they induce in these waves.
As described in the cited patents, the thermal or plasma waves can be detected using a non-modulated probe beam of radiation. The probe beam is focused within the area on the sample surface which has been periodically excited. In one approach, the periodic angular displacements of the reflected probe beam, which are a result of the periodic angular changes in the surface of the sample, are monitored. In an alternate approach better suited to semiconductor samples, the periodic changes in the power of the reflected probe beam, which are a result of the changes in the optical reflectivity of the sample, are monitored. A third approach would include the use of an interferometer configuration for monitoring the periodic changes in the height of the sample surface within the periodically heated region. In each of these approaches, a phase sensitive detection system is used to monitor changes which are synchronous with the modulation frequency of the pump beam.
As described in the above cited patents, when the optical reflectivity of the sample is to be monitored, it is desirable to arrange the pump and probe beams to be coincident on the sample. This configuration helps to maximize the modulated power signal. In contrast, when the angular deflection of the beam is to be monitored, the pump and probe beams are separated a short distance, on the order of one to two microns. This separation functions to maximize the deflection signal.
FIG. 1 is a graph illustrating the signal strength which is available as a function of the distance from the center of the periodically heated spot C. As can be seen from curve 10, the modulated optical reflectivity signal is at maximum at the center of the heated spot and drops off rapidly as the distance from the heated spot increases. This sensitivity pattern would be the same for an interferometric detection system used to monitor periodic changes in the height of the sample due to the periodic heating. Curve 12 illustrates the signal available when measuring the angular deviations of the reflected probe beam. This signal is essentially zero at the center of the heated spot, increases and then once again decreases as the distance from the center of the spot C increases.
The scale of FIG. 1 is dependent on factors such as the thermal conductivity, specific heat and density of the sample as well as the modulation frequency of the pump beam. For a typical semiconductor sample and a modulation frequency on the order of 1 Mhz, the maximum signal strength represented in curves 10 and 12 will be attenuated by approximately 90% at a distance of 2 microns from the center of the periodically excited spot C. Even though the periodically excited region extends beyond two microns, it did not previously appear reasonable to operate with the probe beam separated from the pump beam a distance of more than two microns since the signal strength in that region is so highly attenuated. As will be discussed below, for certain samples, separating the pump and probe beams a distance of two microns or more has some unexpected benefits.

Apparatus for evaluating thermal and electrical characteristics in a sample


A self-contained elevator structure including a pair of vertical, laterally spaced, parallel standards mounting a carrier or carrying cage for vertical travel therealong. Movement of the cage is effected by a multiple-sheave system actuated by a hydraulic piston and cylinder unit in turn controlled by three selectively operated switches, respectively at the top and bottom of the elevator structure, and on the traveling cage itself. The cage switch is capable of activation only when the cage gates or retaining bars are closed. The structure is positionable parallel to and closely adjacent a drilling rig platform with the control system for the vertically traveling cage enabling a stopping of the cage, and access to the rig platform, at any point along the vertical travel of the cage. Safety features include physically actuatable brakes provided on the cage, the use of switches which require constant pressure for actuation, and safety cables and braces between the rig and the standards.

The invention herein is concerned with self-contained elevator constructions which are intended to find particular utility as means for providing access, particularly for personnel, to the platform of a drilling rig.
The use of elevators in this particular environment is known, note for example U.S. Pat. No. 3,592,294 to Allen. However, the known elevator systems have been found to be less than completely satisfactory for a variety of reasons. For example, in the above-noted patent, the elevator assembly is positioned at an inclined angle to the rig platform, thus requiring the use of substantial ground area adjacent the rig and necessitating the provision of means for adjusting the carrying cage so as to maintain a horizontal orientation thereof. In addition, the projection of the elevator assembly forms an obstruction into the surrounding work area. Another readily noted disadvantage is the inability of the patented elevator to provide access to intermediate points along the rig platform between the ground and deck levels.
Known examples of general purpose vertical elevator systems, in some instances incorporating hydraulic actuators in association with cables or chains, are set forth in the following U.S. Pat. Nos.:
220,040 Swartz; PA1 300,132 Rice; PA1 2,770,324 Peterson; PA1 3,003,584 Wiegand et al, PA1 3,207,263 Cull; PA1 3,360,078 Hopfeld; PA1 3,344,890 Loef; PA1 3,934,681 Herrell.
Such known elevator assemblies would find little utility in the particular environment of the invention due particularly to the construction and contemplated manner of operation as expressed in the various patents.


The present invention relates to a wrist support that is designed to maintain a typist's hand, wrist, and forearm in a neutral or aligned position. The wrist support includes a base member having an upper curved surface that partially conforms to the typist's wrist. The base member is preferably fastened to the user's wrist with a flexible strap having a plurality of hook and loop pile patches. An arm extends forward and upward from a front edge of the base member and has a support member at a distal end thereof. The support member is positioned under the user's palm to lightly support the user's hand without unduly restricting movement of the user's fingers. The support member preferably has an upper curved surface that is large enough to comfortably support the user's palm, but small enough so that the user may pivot his or her fingers up or down, backwards and forwards.

1. Field of the Invention
The present invention relates generally to wrist braces and, more particularly, to a wrist support for a typist that supports the typist's palm while allowing upward and forward movement of the typist's hand and unrestricted movement of the typist's fingers.
2. Description of Related Art
Computer users and ten-key operators must type in data for extended periods of time and, therefore, have become more and more concerned with comfort. There are literally hundreds of products available on the market to help increase the comfort of the extended typist. For example, there are various keyboard support devices which allow the keyboard to be variably located at any desired height. There are also devices which allow the user to support his or her wrists on cushioned pads and at variable heights relative to the keyboard. There are even comprehensive carefully designed work stations that include chairs and work surfaces designed to maintain the user's forearm and wrist at the proper height and orientation relative to the keyboard. The alignment of a user's hand, wrist, and forearm is commonly called the "neutral wrist position." The general purpose of all of the foregoing devices is to help the user maintain the neutral wrist position and thereby reduce discomfort normally associated with extended typing or keying.
While the foregoing devices are helpful, they are typically quite expensive. Moreover, the just described devices are not portable and essentially limited to use with an ordinary keyboard permanently located at a single work station. With the advent of the portable computer, a need has developed for a portable typist's wrist support. Moreover, there is a need for a wrist support that is effective for a ten-key typist.
There are innumerable wrist braces on the market for various medical and sports related concerns. However, most of the known wrist braces immobilize the wearer's fingers, wrist or both. There continues to be a need for a wrist support which will support a typist's palm in an appropriate position, but still allow the typist to extend his or her wrist forward and to move his or her fingers independent of the palm support.


A method for transmitting sensed data in a wireless sensor network including multiple sensors and a database, the method includes: automatically dividing the multiple sensors into sensor groups, each of the sensor groups including at least one sensor; determining a lead sensor in each of the sensor groups; encrypting the sensed data to generate encrypted data in ones of the multiple sensors excluding the determined lead sensors; and transmitting the encrypted data.

Wireless sensor networks (WSNs) are gaining worldwide popularity due to their broad applications in different environments, including office, home, and hostile areas. Such WSNs may present a meaningful and efficient solution to challenging problems, such as building safety monitoring, vehicle tracking, wildlife tracking, and environmental surveillance. Advances in micro electromechanical system technology (MEMS), combined with radio frequency (RF) circuits and low cost, low power digital signal processors (DSPs), improve feasibility of these sensor networks.
A WSN may consist of multiple sensors that sense data of interest and transmit the sensed data, directly or indirectly, to a remote database for further processing. The sensors in the WSN are usually power constrained and have limited computational and communication power. Therefore it may be desirable to maximize lifetime of the sensors under this constraint. The lifetime of the sensors depends on effective energy saving strategies such as sensor scheduling and in-network information processing to reduce the amount of sensed data transmitted to a remote database.
One exemplary in-network information processing technique is data aggregation, which has been utilized as a paradigm for wireless routing in sensor networks. Since sensors are usually energy constrained, it may be inefficient and power consuming for all of the sensors to transmit sensed data directly to a remote database for processing. Data sensed by neighboring sensors is often highly correlated and hence redundant. In addition, the amount of the sensed data in a WSN of large size is usually very large for a remote database to process. Data aggregation is a technique that can aggregate data at neighboring sensors or intermediate sensors, which may reduce the amount of the sensed data transmitted to the remote database. As a result, data aggregation can save energy and improve bandwidth utilization for the WSN.
FIG. 1 illustrates a conventional clustered WSN 100. With reference to FIG. 1, the WSN 100 includes non-overlapping clusters 102-1, 102-2, . . . , 102-N (N is the total number of clusters in the WSN 100) with a fixed aggregator or cluster head 104-1, 104-2, . . . , 104-N in each cluster. Each sensor 106-1, 106-2, . . . , 106-M (M is the total number of sensors in the WSN 100) senses certain parameters, such as temperature, pressure, or humidity, of an environment, and encrypts sensed data. Each sensor 106-1, 106-2, . . . , 106-M then transmits its encrypted data to the one of the fixed aggregators 104-1, 104-2, . . . , 104-N in its own cluster. Each fixed aggregator 104-1, 104-2, . . . , 104-N may receive and decrypt the encrypted data received from different sensors in its own cluster and aggregate the decrypted data. Each fixed aggregator 104-1, 104-2, . . . , 104-N may then encrypt the aggregated data and wirelessly transmit the encrypted and aggregated data to a remote database 108 for further processing.
While data aggregation can help improve bandwidth utilization and conserve energy resources by reducing data redundancy, fixed aggregators are usually needed to perform data aggregation. When fixed aggregators perform aggregation of encrypted data received from different sensors in their own cluster, the fixed aggregators may need to decrypt the encrypted data before data aggregation. As a result, security issues may exist in WSNs including such fixed aggregators. Such security issues include data secrecy and data privacy. In terms of data secrecy, sensed data should be protected from attacks, such as known-ciphertext attacks, known-plaintext attacks, and relay attacks, during data transmission. In terms of privacy, sensed data should remain secret to the fixed aggregators. For example, each fixed aggregator 104-1, 104-2, . . . , 104-N should not know the contents of the sensed data received from any of the sensors 106-1, 106-2, . . . , 106-M in its own cluster.
In addition, sensors and aggregators in a conventional clustered WSN like the WSN 100 are usually in fixed positions once the conventional clustered WSN is deployed. New sensors or aggregators may not be added to, and existing sensors or aggregators may not be removed from, the conventional clustered WSN.

Method and system for secure data aggregation in wireless sensor networks

Industrial Technology Research Institute


Method for manufacturing an optical information recording medium includes: preparing a substrate material where a first guide groove has been formed on a first side of the substrate material; forming a second guide groove by applying an energy-curable resin material between a second side of the substrate material opposite to the first side and a stamper and subsequently curing the energy-curable resin material to form a substrate; providing at least one recording layer and a cover layer on a first side of the substrate where the first guide groove has been formed, while holding the substrate with the stamper left unremoved from the substrate to protect the second guide groove; and exposing the second guide groove by removing the stamper and providing at least one recording layer and a cover layer on a second side of the substrate where the second guide groove has been formed.

Conventionally, in an optical information recording medium including recording layers provided on both sides of a substrate, a guide groove for tracking may be provided on each side of the substrate so as to perform excellent tracking during the recording and reading information. See, for example, JP 2004-220634 A and JP H04-372741 A.

Method for manufacturing optical information recording medium


The present invention provides a hydrogenated block copolymer containing, in the molecule thereof, a polymer block (C) having a conjugated diene compound as a main component, a polymer block (B) having a conjugated diene compound as a main component, and a polymer block (S) having a vinyl aromatic compound as a main component.

Polypropylene resin compositions are generally excellent in chemical resistance and mechanical properties and are therefore used in a wide range including packaging materials, machine parts, automobile parts, and the like. Because of environmental necessity, the development of non-halogenated transparent polymer materials has been underway recently. Particularly, in the fields of tubes, sheets, and films, polypropylene resins are used, and there has arisen a demand for, for example, softening the polypropylene resins or rendering the polypropylene resins transparent, according to applications.
Patent Literature 1 discloses a hydrogenated diene copolymer prepared by highly hydrogenating a block copolymer having pre-hydrogenated polymer blocks A, B, and C, wherein the block A has 80% by mass or more of a vinyl aromatic compound, the block B has 70% by mass or more of a conjugated diene compound wherein a vinyl bond content of the conjugated diene compound is higher than 70% by mass, and the block C is polybutadiene having a vinyl bond content of 30% by mass or less. The literature also describes that a molding prepared by blending such a block copolymer thus hydrogenated with a thermoplastic resin such as propylene and molding the blend is excellent in heat resistance, workability, transparency, rigidity, and molding appearance.

Hydrogenated block copolymer, polypropylene resin composition, and molding


Printable elastomer materials that are conductive or insulating and that may be printed in three dimensions (3D) for use in applications, including for example fabrication of actuators such as dielectric elastomer actuators (DEAs).

Dielectric elastomer actuators (DEAs) are configured to transform electric energy directly into mechanical work. DEAs have the potential to replace other types of actuators including, for example, pneumatic actuators, electromagnetic actuators, and piezo actuators.
Certain types of dielectric elastomer actuators (DEAs) are polymeric capacitors capable of converting voltage inputs into mechanical actuation, as well as pressure stimulus into detectable electrical signal. As shown in FIG. 1A, a DEA 20 may essentially act as an electromechanical transducer that consists of a highly stretchable dielectric layer 25. The stretchable dielectric layer 25 is located between two compliant electrodes 27, 29. As shown in FIG. 1B, when an electric field is applied across the compliant electrodes 27, 29—one anode electrode and one cathode electrode—they become oppositely charged and attracted to one another, which induces a mechanical strain. Specifically, the DEA 20 expands in area and contracts in thickness as shown in FIG. 1B.
Research with respect to DEAs has been primarily focused on improving the architecture of the DEAs and enhancing material properties. For example, enhancing material properties of the stretchable conductor and dielectric material may result in greater elongations, application of greater forces, improved electrical/optical properties, and reliable operation. DEA research has resulted in many improvements including transparent and stretchable audio speakers, heel-strike dielectric energy generators (DEGs) that produce approximately 2 Watts (W) per shoe, wave energy generators that produced a peak power of 1.5 W and average of 0.25 W in low wave conditions, strain sensors that are also actuators, and even that act as digital logic and soft diodes for energy generators.
Although efforts have been made to produce DEAs with improved electrical and optical properties, strength, and improved reliability, known DEAs are typically limited to two dimensional (2D) devices and are often assembled manually. The inability to fabricate truly three dimensional (3D) DEAs without great difficulty limits DEA technology.
Thus, there is a need for 3D printable elastomer materials that are conductive or insulating which may be used to fabricate actuators. The invention satisfies this need.


A method of controlling voltage balancing of a modular multi-level converter is provided. The method includes receiving state information on each of n sub modules in an arm module, grouping the n sub modules into m sub module groups, receiving first state information on each of sub modules in a first one of the m sub module groups, among the state information on each of the n sum modules, receiving second state information on each of sub modules not included in the first sub module group, among state information on each of the n sum modules previously stored in a memory, controlling switching of a sub module by using the first state information and the second state information, and updating the memory with the first state information.

The present disclosure relates to a modular multi-level converter, and more particularly, to a method of controlling voltage balancing.
Since high voltage direct current (HVDC) transmission has advantages as compared with high voltage alternating current transmission (HVAC) in that it is possible to perform long-distance transmission and an asynchronous grid connection, use a submarine cable, and perform power control, its applications are steadily increasing.
In an HVDC transmission system, at a transmission side converts and transmits AC power into DC power, and a reception side converts the DC power into the AC power to supply the AC power to a consumer.
Thus, the HVDC transmission system essentially includes a converter in order to convert the AC power into the DC power or convert the DC power into the AC power.
Such a converter includes six arms D1 to D6 as shown in FIG. 1. AC power is converted into DC power by the switching control of respective arms D1 to D6.
Each of arms D1 to D5 includes a switch. However, there is a limit in a voltage that a single switch may stand.
Thus, a modular multi-level converter has been recently proposed in which each of arms D1 to D6 includes a plurality sub modules and which may thus stand a high voltage by the selective switching control of each sub module.
Each sub module includes two insulating gate bipolar transistor (IGBT) and a capacitor.
The number of sub modules that each of arms D1 to D6 includes may be determined according to the processing capacity of the modular multi-level converter and may be up to several hundreds. However, it is not easy to perform selective switching control on the sub module.
In particular, the voltage value of the capacitor in the sub module is not fixed due to an operation condition but varies. In addition, in the case where a large number of sub modules are manufactured by different manufacturers, the specification of the capacitor of each sub module may be different from each other. Thus, the capacitance of the capacitor of each sub module may be different from each other and due to such a difference in the capacitance of the capacitor, the capacitance voltage of the capacitor of each sub module may vary. The capacitor value is a voltage charged in the capacitor.
Since the charging time of the voltage charged in the capacitance is different from each other when the capacity of the capacitance of each sub module is different from each other, the switching frequency of a sub module that has low capacitance sharply increases, and the switching frequency of a sub module that has high capacitance sharply decreases. If the switching frequency of each sub module sharply increases or decreases in this way, there is a drawback in that the life of the IGBT in the sub module shortens.
Since it makes the life of the sub module short, there is an urgent need for a technology that constantly maintains the capacitor voltage of the sub module.

Modular multi-level converter and method of controlling voltage balancing of modular multi-level converter


An adjustable rugged antenna coupler assembly for primary use in portable radios. Connector means in combination with a pair of gasket means, signal carrying means and encasement means combine to provide an improved adjustable antenna coupler assembly. The connector means is mated with complementary threadings in the radio casing thereby providing an antenna coupler readily adjustable such that the antenna is always pointed in a desired direction, such as skyward.

The present invention relates generally to antenna mountings and more particularly to an environmentally rugged a infinitely adjustable structure for mounting a mobile antenna capable of withstanding stringent environmental applications.
Prior to the present invention a variety of structures have been devised for mounting antennas to portable radios. Representative of such structures are apparatuses having a ratchet or detent bushing attached using ring clamps or a press fit assembly, or a fixed mounted whip antenna structure. Such structures have provided satisfactory solutions to various design challenges, but suffer failure and system degradation due to mechanical wear associated with adjusting of the antenna. Additionally, sand, dust or other contaminants may enter the apparatus thereby causing premature failure or difficult operational use. Water damage, a particular type of contaminant, can be especially troublesome with prior art techniques failing to adequately address such concerns in high humidity or immersed conditions.
Another significant shortcoming of numerous prior art structures concerns coupling the signal from the antenna to the associated device. Slide connections and directly coupled coaxial cables have typically been used, but generally result in intermittent failure and an overall shortened life of the structure.
Accordingly, a need exists for an improved antenna extender apparatus capable of prolonged use in an application requiring an adjustable antenna that is environmentally rugged.


A tablet holder includes a generally square base having a protuberance formed in each side of the base, each protuberance extending radially outwardly with respect to a center of the base. Each protuberance is recessed relative to the base, creating a channel having a bottom wall and upstanding sidewalls. A detent plate is mounted in each channel and has a range of travel relative to the bottom wall. A raising and lowering assembly raises and lowers the detent plate. Guide rails are formed in each channel and a holder is slideably mounted to the guide rails. Each holder has a slotted bottom plate, guide rail housings for slideably receiving the guide rails, on opposite sides of the slot, and an upstanding end wall adapted to abuttingly engage a tablet. Each holder is slideably adjustable or locked against sliding when the detent plate is elevated or lowered, respectively.

1. Field of the Invention
This invention relates, generally, to tablet holders. More particularly, it relates to a tablet holder having tool-free adjustment means that enables the secure holding of tablets of varying sizes in both landscape and portrait orientations.
2. Description of the Prior Art
The known stands that could be adapted to hold a tablet are one-size-fits all stands, i.e., they are not adjustable and therefore cannot grip tablets of differing sizes.
Some tablet protective covers are foldable to support the tablet at various angles. The number of angles is limited.
Tripods, both full size and tabletop-size, are equipped with a screw that enables a camera or a camcorder to be mounted thereon. Tripod mounting is advantageous because the device mounted thereto can be held in an infinite number of orientations. However, there are no known tablet holders that can be mounted on a tripod.
Thus there is a need for an adjustable tablet holder that holds tablets of widely differing sizes at any desired angle and which frees both hands of the user.
There is also a need for a light-in-weight, mechanically robust tablet holder that can be adjusted without tools to hold tablets of differing sizes.
There is also a need for a tablet than can be mounted on a tripod.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the needed tablet holder could be provided.


A terminal device and a method for removing dust in a sound outlet hole of a loudspeaker are provided. The method includes the following: measuring a natural frequency of the loudspeaker, generating an audio file for removing dust according to the natural frequency, and prestoring the audio file for removing dust, wherein a vibration amplitude of a vibration diaphragm of the loudspeaker is at a maximum when the vibration diaphragm is driven to vibrates by an exciting current having the natural frequency; reading the prestored audio file for removing dust; and controlling the loudspeaker to play the audio file for removing dust, to generate air flow in the sound outlet hole, wherein when the loudspeaker plays the audio file for removing dust, a wind speed of the air flow through the sound outlet hole is at a maximum.

In a terminal device, for example, a mobile phone or a tablet computer, a sound unit of a loudspeaker is usually disposed inside the terminal device and generates sound to outside from the terminal device via a sound channel A dust cloth usually covers a position of a sound outlet hole to prevent sound quality from being affected by dust in the environment from entering an interior of the terminal device via the sound channel. However, when the dust cloth is used, the dust is easily deposited on the dust cloth, so that the area of the sound outlet hole of the sound channel is decreased. Accordingly, volume of the loudspeaker is small, and even noise occurs.
In the prior art, a user needs to clean the dust cloth at the position of the sound outlet hole manually. In special circumstances, it is necessary to take the terminal device to a service station, where the dust on the dust cloth may be removed manually only when the terminal device is disassembled. As a result, it is not convenient to remove the dust in the sound outlet hole of the loudspeaker.

This patent is subject to a terminal disclaimer.

Method for removing dust in sound outlet hole of loudspeaker, and terminal device

GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.


Disclosed is a method of making 3-hydroxy-2,4,5-trifluorobenzoic acid. A aqueous solution is prepared of an alkali metal base and a tetrafluorophthalimide. The solution is heated to produce a mixture of a salt of a 4-hydroxy-3,5,6-trifluorophthalamic acid and a salt of a 3-hydroxy-2,4,5-trifluorobenzamide. The solution is neutralized with acid to form a precipitate of the 4-hydroxy-3,5,6-trifluorophthalamic acid and the 3-hydroxy-2,4,5-trifluorobenzamide. The precipitate is reacted with a mineral acid to produce 3-hydroxy-2,4,5-trifluorobenzoic acid.

This invention relates to a method of making 3-hydroxy-2,4,5-trifluorobenzoic acid (HTBA) from an N-alkyl or N-aryl tetrafluorophthalimide. Specifically, a tetrafluorophthalimide is reacted with a base to produce a mixture of the salts of a 4-hydroxy-3,5,6-trifluoro N-substituted phthalamic acid (HTPA) and a 3-hydroxy-2,4,5-trifluoro N-substituted benzamide (HTB), the base is neutralized to form the HTPA and HTB, and the precipitate is acidified, which forms the HTBA.
U.S. Pat. No. 4,831,190, herein incorporated by reference, discloses a process for making HTBA by reacting tetrafluorophthalic acid with a base to form 4-hydroxy-3,5,6-trifluorophthalic acid, which is then decarboxylated. While that process is not known to be unsatisfactory, the starting material, tetrafluorophthalic acid, is considered to be too expensive for many applications.

Method of making 3-hydroxy-2,4,5-trifluorobenzoic acid


A control unit for controlling a modem used in a receiver demodulates a received signal by use of an adaptive equalizer, and a recovery circuit includes a timing recovery function and a carrier recovery function. States regarding operations in the adaptive equalizer and the recovery circuit are updated based on the received signal. The modem includes a determination unit for determining whether or not the modem is operating unusually based on a signal processed in the modem, a buffer for storing state data at a predetermined timing when the determination unit determines that the modem is not operating unusually, and a controller for controlling the adaptive equalizer and the recovery circuit so that the adaptive equalizer and the recovery circuit operate based on the state data which has been stored in the buffer when the determination unit determines that the modem is operating unusually.

The present invention generally relates to a control unit for controlling a modem, more particularly to a modem which is used for a mobile communication system such as facsimiles used in vehicles, and has an equalizing function, a timing recovery function and a carrier recovery function.
In general, a modem in a receiver demodulates a received signal, which has been modulated in accordance with a PSK (Phase Shift Keying), a DPSK (Differential Phase Shift Keying) or the like, so as to reproduce transmitted data. In a case where the modem demodulates the received signal, a transmission characteristic which affects the transmitted signal in a transmission path, a frequency offset which is the difference between a frequency of a carrier in a transmitter side and a frequency of a carrier in a receiver side, and a carrier phase jitter are respectively corrected. Then a synchronous signal is extracted from the received signal, and thus the transmitted data is reproduced from the received signal in synchronism with the synchronous signal.
The transmission characteristic is corrected by an adaptive equalizer provided in the modem. Coefficients in the adaptive equalizer are updated periodically at a predetermined symbol rate so that a characteristic of the adaptive equalizer cancels the transmission characteristic. The frequency offset and the carrier phase jitter are respectively corrected by a carrier recovery section in the modem. The carrier recovery section rotates a received signal point on a signal constellation by an amount of phase shift which is presumed to correct the frequency offset and carrier phase jitter. The synchronous signal is extracted from the received signal by a timing recovery section in the modem. In a case where the transmitted data is modulated in accordance with PSK, the timing recovery section carries out, for example, the following process so that the synchronous signal is extracted. A bandpass signal (received signal) is multiplied by the carrier and passes through a wave shaping filter so that a complex baseband signal is obtained. Then the complex baseband signal is squared. A synchronous frequency component is extracted from a signal obtained by the above square calculation by a bandpass filter, so that the synchronous signal is obtained. In general, while the received signal is being processed in a case where the synchronous signal is reproduced from the received signal, various coefficients, such as coefficients in the adaptive equalizer, are obtained. Timing information for obtaining a synchronous timing can be extracted from the received signal based on the above various coefficients, and then a sampling period in an analog to digital converter which converts the received signal into digital data can be controlled based on the timing information, so that the transmitted data is reproduced in synchronism with the timing information.
Recently, a modem provided in a mobile communication system, such as a facsimile used in a vehicle, has been examined. The mobile communication system has radio transmission paths. When disturbances are supplied via the radio transmission paths to the modem, functions in the modem can deteriorate. For example, sudden disturbances, such as a short break in the transmitted signal, an amplitude and phase hit and the like, can be generated. Due to these sudden disturbances, the modem has the following trouble. That is, the coefficients in the adaptive equalizer are controlled so as to be diverged, so that the adaptive equalizer malfunctions. In addition, an amount of phase shift which is a presumption error of an amount of phase rotation is increased, and/or the synchronous signal cannot be detected due to timing errors. In these cases, the modem malfunctions, for example, it hangs up.
A high density digital magnetic recording system, such as a DAT (Digital Audio Tape Recorder), also has a problem in that the system malfunctions due to these disturbances. In the high density digital magnetic recording system, when a frequency characteristic of an input signal greatly varies due to scratches, dust and the like, a transmission characteristic of a wave shaping equalizer in the digital magnetic recording system varies. Thus, until the transmission characteristic of the wave shaping equalizer returns to normal, a signal having a distorted wave shape is output from the wave shaping equalizer. As a result, an error rate in a reproduced signal increases. To eliminate the above problems in the digital magnetic recording system, an art disclosed in Japanese Patent Laid Open Publication No. 1-279617 has been proposed.
That is, this art relates to an automatic equalizer in which a signal used in a process for a digital recording of a PCM signal is shaped so that the distortion of the signal is decreased. This automatic equalizer includes a wave shaping equalizing circuit having a transversal type filter, a level detector which detects the level of the input signal, a setting circuit which sets coefficients in the transversal filter based on an input and an output of the wave shaping equalizing circuit, and a control circuit which controls operations in the setting circuit based on the output of the level detector. When the level detector detects that the level of the input signal has become less than a normal level, the control circuit supplies information that the level of the input signal has decreased to the setting circuit. Then the setting circuit stops updating the coefficients in the transversal type filter, so that the coefficients are maintained at predetermined values. Due to the above control operation performed in the automatic equalizer, the characteristic of the automatic equalizer can be prevented from greatly decreasing.
In addition, when the setting circuit is provided with a memory which stores a history of the coefficients in the transversal type filter, the coefficients which are maintained based on the operation of the level detector can be selected from the history stored in the memory. Hence, the coefficients can also be prevented from being set at unusual values based on delay of the detecting operation in the level detector.
However, the prior art related to the digital magnetic recording system can not be applied to the modem in the mobile communication system. That is, since the phase of the carrier in the received signal of the facsimile or the like also varies, the modem cannot be controlled by only the level detector.

Control unit for controlling modem used in receiver


The invention relates to DNA molecules which code for deacetylases or proteins having the biological activity of a deacetylase and also transgenic plant cells which were transformed using the DNA molecules according to the invention. These molecules can be used for the production of plants having specifically destroyable parts, i.e. male- or female-sterile plants, by means of the specific expression of a deacetylase gene.

The concept of a chemically inducible, reversible male sterility in plants by anther-specific expression of an N-acetylphosphinothricin (N-acetyl-PPT)-specific deacetylase is described in European Patent Application EP 531 716. The deacetylase genes from Streptomyces viridochromogenes [N-acetyl-L-phosphinothricylalanylalanine (N-acetyl-PTT) deacetylase, dea] and argE from Escherichia coli (N-acetyl-L-ornithine deacetylase) used here encode proteins having specificity for N-acetyl-L-PPT. For both genes, it was possible in the case of tapetum-specific expression in plants to show the occurrence of male-sterile flowers after treatment of individual buds with N-acetyl-L-PPT. For successful use of this system, in particular in the treatment of whole plants with N-acetyl-PPT under practically relevant conditions, it is advantageous to be able to employ deacetylases having high substrate affinity. Therefore further deacetylases having high affinity for N-acetyl-PPT were sought.
The application described here is thus based on the object of making available DNA molecules which code for deacetylases. Using these deacetylases, it is possible to produce plants having plant parts which can be destroyed specifically. The production of male- or female-sterile plants is of particular interest. The object is achieved by the provision of the embodiments described in the patent claims.
The invention relates to DNA molecules which code for deacetylases or proteins with the biological activity of a deacetylase. The enzymatic properties of these proteins are described in the examples. The invention also relates to DNA molecules which encode a biologically active subfragment or a derivative. The molecules according to the invention also include fragments, derivatives or allelic variants. Fragments are understood as meaning parts which still have the biological activity of a deacetylase.
The invention additionally relates to transgenic plant cells which have been transformed using the DNA molecules according to the invention. The transgenic plant cells can be prepared according to known techniques and are regenerated to give whole plants.
The invention relates to DNA molecules encoding a protein having the biological activity of an N-acetyl-PPT deacetylase.
The invention relates in particular to DNA molecules encoding a protein having the biological activity of an N-acetyl-PPT deacetylase selected from the group consisting of
a) DNA molecules which code for a protein having the amino acid sequence indicated under SEQ ID NO: 2 and fragments and/or derivatives thereof;
b) DNA molecules which code for a nucleotide sequence indicated under SEQ ID NO: 1 or sequences which deviate from this sequence within the bounds of code degeneracy;
c) DNA molecules which code for a protein having the amino acid sequence indicated under SEQ ID NO: 4 or fragments and/or derivatives thereof and
d) DNA molecules which code for a nucleotide sequence indicated under SEQ ID NO: 3 or sequences which deviate from this sequence within the bounds of code degeneracy.
The invention additionally relates to the microorganisms Stenotrophomonas sp. (DSM 9734) and Comamonas acidovorans (DSM 11070) identified and deposited according to the method described in this application.
The invention relates in particular to plant cells or plants which contain the DNA molecules according to the invention.
Of particular interest are processes for the production of plants with specifically destroyable parts by means of specific expression of a deacetylase gene and processes for the production of male- or female-sterile plants by means of specific expression of a deacetylase gene.
The present application thus also relates to:
(1) the specific concentration of microorganisms having high N-acetyl-PPT deacetylase activity
(2) the isolation of corresponding deacetylase genes
(3) the purification and characterization of the proteins having high N-acetyl-PPT deacetylase activity encoded by these genes
(4) the expression of the deacetylase genes in plants.
The present application additionally relates to:
the DNA molecules which code for enzymes having high N-acetyl-PPT deacetylase activity
the proteins which are encoded by these genes
the expression of these deacetylase genes in plants.
From soil samples, bacteria can be concentrated in mineral medium with chitin as the sole carbon source which are able to cleave N-acetyl-PPT with high effectiveness. In this manner, 2 bacterial strains were isolated as pure cultures: Stenotrophomonas sp. (DSM deposit No. DSM 9734) and Comamonas acidovorans (DSM deposit No. 11070).
For the conditions necessary in industrial production, however, it is substantially more advantageous to be able to employ a purified enzyme.
The present application comprises novel L-N-acetyl-PPT specific deacetylases, a novel and effective process for the purification and characterization of this enzyme from a concentration culture of soil microorganisms, and the use of this deacetylase.
The invention thus further relates to:
1. A deacetylase having
a molecular weight of 20,000 to 100,000 Daltons
a pH optimum of 6.5-10.0
a substrate specificity to L-N-acetyl-phosphinothricin.
2. A process for the preparation of a deacetylase, which comprises culturing a microorganism which does not form spores in a medium comprising crab chitin, and isolating the deacetylase from these microorganisms.
3. The use of the deacetylase characterized under 1. for the production of male-sterile plants and for the stereoselective preparation of L-phosphinothricin.
The invention relates in particular to an enzyme which has a temperature optimum which lies between 30xc2x0 C. and 50xc2x0 C.
The process according to the invention for the preparation of the deacetyl-ases is preferably carried out using microorganisms selected from the group which consists of the microorganisms described in the application.
Crab chitin can be obtained as described by Shimahara, Kenzo and Takiguchi, Yasuyuki (Methods in Enzymology, Vol 161, pages 417-423, 1988) or is commercially available from Sigma.
To purify the deacetylase, the microorganism is cultured in a nutrient medium optimal for its growth. The microorganism is cultured aerobically, for example submerse with shaking or stirring in shaker flasks or fermenters, if appropriate with introduction of air or oxygen. The fermentation can be carried out in a temperature range from approximately 20 to 40xc2x0 C., preferably at approximately 25 to 37xc2x0 C., in particular at 30 to 37xc2x0 C. Culture takes place in a pH range between 5 and 8.5, preferably between 5.5 and 8.0.
Under these conditions, the microorganisms in general show a noticeable accumulation of the enzyme after 1 to 3 days. The synthesis of the deacetylase begins with the log phase. The production of the enzyme can be monitored with the aid of activity tests by HPLC analysis or photometrically. The nutrient solution used for the production of the transaminase contains 0.2 to 5%, preferably 0.5 to 2%, of crab chitin and inorganic salts.
Inorganic salts which the nutrient medium can contain are, for example, chlorides, carbonates, sulfates or phosphates of the alkali metal or alkaline earth metals, iron, zinc and manganese, but also ammonium salts and nitrates.
According to the invention, effective amounts of the deacetylase can be employed in free or immobilized form for the deacetylation, preferably it is employed in plants which express dea genes.
For fixation, the known processes are suitable, such as the processes described in German Offenlegungsschriften 32 37 341 and 32 43 591.
The enzyme can be isolated and purified by classical methods by means of decomposition by ultrasound and French press, ammonium sulfate precipitation, ion exchangers, affinity chromatography and gel permeation.
The enzyme preparation can have a molecular weight of 20,000 to 100,000 Daltons, preferably 30,000 to 80,000, in particular 40,000 to 70,000 Daltons. The pH optimum of the enzyme product lies in the pH range 6.0 to 10.0, in particular 7.0 to 8.0. The temperature optimum of the enzyme lies between 30 and 50xc2x0 C., in particular between 35 and 45xc2x0 C.
The genes coding for the deacetylases were cloned in E. coli. In the case of the deac1 gene from Stenotrophomonas sp., a phagemid expression bank from genomic DNA in E. coli was screened for N-acetyl-PPT-specific deacetylase activity. The deac2 gene from Comamonas acidovorans was cloned with a genomic bank by complementation of an E. colixe2x80x94argE mutant.
The amino acid sequences derived from the DNA sequences of the two genes are similar to one another and additionally have homology to hippurate hydrolases, as are known from protein databanks.
The high substrate affinity of the deac1 protein for N-acetyl-L-PPT (Km=670 xcexcM) makes itself noticeable in the transgenic plants by a high sensitivity of the tissue to this substance. Thus in constitutive expression of the deac gene plants can be obtained whose leaves still react sensitively to concentrations of up to 0.4 mg/ml of N-acetyl-D,L-PPT(=0.2 mg/ml of L-enantiomer). In the case of tapetum-specific expression, the induction of male-sterile flowers was achieved by treatment of the buds with 2 mg/ml of N-acetyl-D,L-PPT(=1 mg/ml of L-enantiomer). The results described relate to greenhouse plants. On the basis of the low substance concentrations, if required, under open air conditions a higher dose of around 5-10-fold is possible without problems.

Genes coding for amino acid deacetylases with specificity for N-acetyl-L-phosphinothricin, their isolation and use


A cuffed tracheal tube has a suction lumen extending along the tube and opening through a suction aperture immediately adjacent the upper, proximal end of the cuff. The inflatable cuff is attached to the external surface of the tube by collars. The proximal collar is everted within the inflatable portion of the cuff so that it does not extend beyond the inflatable portion and so that the maximum amount of secretions can be removed through the suction aperture.

This invention relates to medico-surgical tubes and assemblies.
The invention is more particularly concerned with cuffed medico-surgical tubes, such as, for example, cuffed tracheal tubes in which an inflatable cuff seals the tube with a patient's trachea.
Such cuffed tubes can present a problem in that secretions produced above the cuff in the trachea, or other body channel in which the tube is located, will be prevented from flowing along the channel and will thereby collect above the cuff, providing a site for the accumulation of bacteria and infection.
Various proposals have been made previously for removing such secretions by providing a suction aperture above the cuff. In Heyden U.S. Pat. No. 4,607,635 there is described a tracheal tube having a channel which opens at various locations along its length and through which a suction catheter can be inserted to remove secretions at any desired location above the cuff. In Chester U.S. Pat. No. 4,305,392 there is described a tracheal tube with a bulbous chamber above the cuff in which secretions are collected for removal through a suction lumen extending through the wall of the tube. The problem with both of these tubes is that it is not possible to remove secretions that collect immediately above the cuff. This is because the cuff is ccnventionally attached to the wall of the tube by means of short collars at opposite ends of the cuff, which are adhered to the tube and extend above and below the cuff. The length of the collar above the cuff defines the closest distance by which the suction aperture can be spaced from the cuff, because any attempt to form a suction aperture through the collar would weaken the join of the cuff to the tube and possibly lead to leakage from the cuff. In Porter U.S. 4,840,173 there is suggested a way in which secretions close to the cuff could be removed, by providing a suction tube which projects over the proximal collar of the cuff. This, however, would have the disadvantage of being relatively complex and expensive to make and provides an undesirable projection from the side of the tube which could irritate the delicate surface of the trachea. There is also the risk that the end of the suction tube may damage the cuff or become blocked by the cuff. This risk can be reduced by making the upper end of the cuff more rigid, but this is a further complication in the construction of the tube.

Medico-surgical tube with sealing cuff and a suction lumen at the top of the cuff

Smiths Industries Public Limited Company


An apparatus and method are provided for detecting cylinder misfires in an internal combustion engine of a motor vehicle by digitally filtering out noise-related signals to improve the signal to noise ratio. Crankshaft rotation is sensed and crankshaft velocities are measured for each cylinder. Changes in angular velocity are determined and correspond to each of a plurality of cylinder firing events. A window of consecutive changes in angular velocity are used with a digital filter. The digital filter contains filter coefficients which are determined from a frequency analysis for a given engine by distinguishing between actual misfire events and noise related event frequencies. From the analysis a cut off frequency between actual misfires and noise is determined which is then used to determine the filter coefficients. The digital filter generates a filter output for the current cylinder firing event and the filter output is preferably multiplied by a gain to provide a compensated filter output. The compensated filter output is compared to a threshold value and a misfire event is determined for the selected cylinder based on the comparison. A high pass filter may be employed to filter out low frequency noise-related signals such as those associated with a power train bobble. Similarly, a low pass filter can be used to filter out high frequency noise signals such as those associated with crankshaft torsional vibrations. Both high and low pass filters could be employed in the alternative by using a high pass filter at low engine speeds and a low pass at high engine speeds.

1. Technical Field
The present invention relates generally to internal combustion engines and, more particularly, to a misfire detection apparatus and method with digital filtering to reduce noise-related effects and improve signal to noise ratio for detecting misfire of individual cylinders in an internal combustion engine.
2. Discussion
Pollution control legislation has required motor vehicle manufacturers to reduce exhaust emissions of carbon monoxide, hydrocarbons, and oxides of nitrogen from motor vehicles. To comply with the legislative requirements, most motor vehicle manufacturers generally use catalytic converters on production vehicles to control such exhaust emissions. A catalytic converter typically includes a catalyst and operates at a very high temperature in order to burn unwanted byproducts of combustion so as to reduce hydrocarbons, carbon monoxide and nitrous oxide. However, increased amounts of unburned byproducts that often remain after the occurrence of an engine misfire can lead to damage of the catalytic converter.
More recently, regulatory agencies have proposed that passenger, light-duty and medium-duty motor vehicles with feedback fuel control systems be equipped with a malfunction indicator function that will inform the motor vehicle operator of any malfunction of an emission-related component that interfaces with an on-board computer of the motor vehicle. It is also proposed or required that an on-board diagnostic system identify the likely area of malfunction. Proposals or requirements have set forth catalyst, misfire, evaporative purge system, secondary air system, air conditioning system refrigerant, fuel system, oxygen sensor, exhaust gas recirculation, and comprehensive component monitoring requirements.
As previously mentioned, misfire of internal combustion engines can cause damage to the catalyst of a catalytic converter. With respect to misfire, the identification of the specific cylinder experiencing misfire may be required. Some regulations provide that the motor vehicle manufacturer specify a percentage of misfires out of the total number of firing events necessary for determining malfunction for: (1) the percent misfire evaluated in a fixed number of revolution increments for each engine speed and load condition which would result in catalyst damage; (2) the percent misfire evaluated in a certain number of revolution increments which would cause a durability demonstration motor vehicle to fail a Federal Test Procedure (FTP) by more than 150% of the applicable standard if the degree of misfire were present from the beginning of the test; and (3) the degree of misfire evaluated in a certain number of revolution increments which would cause a durability demonstration motor vehicle to fail an inspection and maintenance (IM) program tailpipe exhaust emission test.
Current and proposed future regulations are also requiring that motor vehicle manufacturers be able to provide information detailing the occurrence of misfires such as identifying which cylinders are responsible for one or more misfires. The misfire information need be collected and stored in memory so that the stored information may be downloaded at a service center and used to determine the cause of misfires in the vehicle. One misfire detection and identification approach is disclosed in issued U.S. Pat. No. 5,361,629 issued Nov. 8, 1994 and titled "Single Sensor Misfire Detection Apparatus and Method for an Internal Combustion Engine". The above-cited patent is hereby incorporated by reference. The misfire detection approach in the above-cited patent senses rotation of a crankshaft and calculates a crankshaft velocity based on the sensed rotation. The calculated crankshaft velocity changes or a compensated velocity change is compared to a predetermined crankshaft velocity range to determine if misfire occurred.
More recent misfire detection approaches are disclosed in pending U.S. patent application Ser. No. 08/468,117, filed Jun. 6, 1995, entitled "Engine Misfire Detection with Compensation for Normal Acceleration of Crankshaft", U.S. patent application Ser. No. 08/469,040, filed Jun. 6, 1995, entitled "Engine Misfire Detection with Rough Road Inhibit", and U.S. patent application Ser. No. 08/468,113, filed Jun. 6, 1995, entitled "Engine Misfire Detection with Cascade Filter Configuration". The aforementioned applications are commonly assigned to the assignee of the present application and are hereby incorporated by reference. The above referenced approaches generally teach misfire detection which includes sorting a plurality of changes in angular velocity over a predetermined series of cylinder firings and averaging the two middle-most angular velocity changes to provide an average change in velocity value. A deviation is determined between the change in angular velocity for a selected cylinder and the average change in velocity value. Misfires are detected as a function of a comparison of the deviation with a threshold value.
A number of conventional approaches are generally susceptible to detecting a false misfire which is really a disturbance caused by a previous misfire. This is often referred to as a misfire induced power train bobble. Additionally, some misfire detection approaches can be tricked into falsely identifying noise, which can be generated by crankshaft torsional vibrations, as a misfire. For example, high engine speed can cause large torsional vibrations that would signal a false misfire detection. Excessive amounts of noise can cause difficulties in detecting occurrences of actual misfires.
In particular, the above-incorporated U.S. application Ser. No. 08/469,040 entitled "Engine Misfire Detection with Rough Road Inhibit" inhibits misfire detection upon detecting noise related events such as a rough road condition. Using this inhibit technique results in a period of time over which misfire detection is deactivated. The inhibit time periods can become quite extensive, at certain operating conditions, especially at low engine speeds and high manifold pressures. While such an approach may be effective to avoiding false misfire detection, it may be preferable to realize continuous misfire detection without the occurrence of inhibit time periods. Accordingly, it is desirable to provide for a misfire detection apparatus and method which would allow for continuous misfire detection, despite the presence of noise-related events.
It is therefore one object of the present invention to provide for a misfire detection apparatus and method of continuously detecting cylinder misfires in an internal combustion engine which effectively reduces or eliminates noise-related events.
It is another object of the present invention to provide for a misfire detection apparatus and method which removes noise signals and achieves enhanced signal to noise ratio to better distinguish actual misfires from noise-related events.
It is a further object of the present invention to provide for a misfire detection apparatus and method which distinguishes misfire induced power train bobble effects from actual misfires.
It is yet another object of the present invention to provide a misfire detection apparatus and method which distinguishes high frequency noise events such as crankshaft torsional vibrations from actual misfires.

Engine misfire detection with digital filtering


An example method is provided in according with one implementation of the present disclosure. The method includes receiving location-locked data (LLD), receiving at least location information related to a permitted region, and deterministically generating at least one location-specific encryption key (LSK) based at least on the location information related to the permitted region. The method further includes encrypting the LLD such that the encrypted LLD can be decrypted using one of the at least on LSK.

Electronic devices equipped with a diverse set of functions continue to play an increased role in people's life. These devices can communicate with each other, reach the Internet, print or display different content, perform various tasks, or access data services through networks. Various devices such as personal computers, printers, all in one computing devices, Internet-enabled tablets, laptops, televisions, and gaming consoles have become essential personal accessories, connecting users to friends, work, and entertainment.

HEWLETT PACKARD ENTERPRISE DEVELOPMENT LP


A process is provided for ultrasonically welding a rigid thermoplastic, such as acrylic, and a flexible thermoplastic, such a polyvinyl chloride (PVC) doped with plasticizers. The rigid piece includes an energy director where the joint is to be located. The energy director includes first and second ridges running the length of the joint and a groove running between the first and second ridges. The energy director is placed against one side of the flexible piece, and an ultrasonic horn against the other side opposite the energy director. The two pieces are then welded together using standard ultrasonic technology. The shape of the energy director promotes the melting and flow of both pieces as they are being welded together.

Ultrasonic welding has long been used to join together two thermoplastic pieces. Prior to the present invention, it had been thought that materials having different properties, such as a rigid piece and a flexible piece, were generally not suitable for being ultrasonically welded together. It had also been thought that it was difficult to ultrasonically weld plasticized polyvinyl chloride with good results, especially to another type of material.
Energy directors have been used to improve ultrasonic welding. These prior art energy directors typically have a single peak, which is sometimes roughened for particular applications.

Process and energy director for ultrasonic welding and joint produced thereby