A shrink-fit chuck tool holder for cylindrical, particularly circular cylindrical, shank tools, including a fastening shank for establishing connection to a machine tool and a thermally expandable shrink section. The shrink section has an inside recess for accommodation of a tool shank and a pre-positioning section, which precedes the recess via a step and has an axial extension. The pre-positioning section is disposed eccentrically to the inside recess.

1. Field of the Invention
The present invention relates to a chucking device for fastening a tool in a machine tool, particularly in the form of a shrink-fit chuck tool holder for cylindrical, particularly circular cylindrical tools, and to a chucking device for tensioning tools by the shrink-fit chuck.
2. Discussion of the Background
In metal machining operations, today primarily machine tools with high levels of automation are used in production. The chucking and gripping systems, into which the insert tools are clamped and which in turn are held in corresponding holders of the machine tool, for example standardized cylinder shank holders or hollow taper shank (HSK) jaws, significantly influence the quality of workpieces as well as the efficiency of the production processes.
Compared to conventional chucking devices, such as three-jaw chucks or extension chucks, shrink-fit chuck tool holders have greater rigidity in terms of the tool/tool holder unit and achieve greater transmittable torque. As a result, surface improvements on the workpiece, greater manufacturing precision and a longer service life of the tool can be achieved and production processes with extremely high rotational speeds and feed rates can be implemented, for example the so-called high-speed cutting (HSC).
Conventional devices available on the market for chucking insert tools in shrink-fit chucks are provided with a heating unit, for example using hot air or with the help of an induction coil, by which a tool holder is expanded so that the tool (which is still cold) can be inserted in the shank of the tool holder. After cooling and the associated shrinkage of the tool holder, the tool is tightly clamped in place. This way, low pairing tolerances for the pairing of the tool and tool holder and an accordingly tight fit of the tool are achieved.
Clamping devices in this category, particularly shrink-fit chucks, and chucking fixtures, which are also referred to as shrink fixtures, are described, for example, in the documents DE 101 38 107 A1 and EP 830917 B1.
To ensure clean positioning of the cold tool on the shrink-fit chuck, the tool shank is typically provided with a chamfer. To facilitate the insertion process, the recess of the shrink-fit chuck provided for accommodating the tool shank according to EP 830917 B1 has an insertion section, which allows pre-positioning of the tool shank in the cold state of the tool holder.
In this known case, the configuration is selected such that the insertion section holds the tool until the temperature of the shrink section or of the shrink-fit chuck is sufficiently high and the inside recess has expanded so much in terms of width or diameter that it has reached, or even exceeds, the outside dimension of the shank. When the tool and hence the shrink-fit chuck are oriented vertically in the shrink fixture, the tool glides into the shrink-fit chuck under the effects of gravity.

Shrink-fit chuck with eccentric positioning


A computer-implemented method for processing data includes receiving an initial set of records including terms describing respective items in specified categories. Based on the initial set of records, respective term weights are calculated for at least some of the terms with respect to at least some of the categories. Each term weight indicates, for a given term and a given category, a likelihood that a record containing the given term belongs to the given category. Upon receiving a new record, not included in the initial set, respective assignment metrics are computed for two or more of the categories using the respective term weights of the particular terms in the new record with respect to the two or more of the categories. The new record is classified in one of the two or more of the categories responsively to the assignment metrics.

Companies and other organizations commonly maintain large quantities of data in different databases and in different formats (even within the same database). Data mastering—compiling diverse data into a single, unified database while eliminating duplication and errors—has become increasingly important in ensuring data quality and accessibility. A number of software-based tools are available for automated data mastering, such as Zoomix ONE, produced by Zoomix Data Mastering Ltd. (Jerusalem, Israel).
One of the challenges of data mastering is accurate matching and grouping of records. For example, enterprise databases frequently contain duplicated data records, in which the same entity (product, customer, etc.) is represented by multiple, non-identical records. These duplications, if uncorrected, can cause substantial wasted expense and adversely affect relations with customers and suppliers. Matching and grouping are also important in data cleansing (detection and correction of data errors) and categorization.

Methods and apparatus for automated matching and classification of data


A power converter has a phase leg with upper and lower switching devices coupled across a DC link. A junction between the devices is coupled to a load. A current sensor detects direction of current flow from the junction to the load. A gate driver activates the devices according to upper and lower gate signals in response to pulse-width modulation (PWM) to generate nominal gate signals from a variable duty cycle. When the positive current direction is detected then the upper gate signal has turn-on and turn-off times shifted by a predetermined offset with respect to the nominal signals, and dead-times are added to the lower gate signals. When the negative direction is detected then the lower gate signal has turn-on and turn-off times shifted by the predetermined offset with respect to the nominal signals, and dead-times are added to the upper gate signals.

The present invention relates in general to power converters including inverters for an electric drive system of an electrified vehicle, and, more specifically, to pre-compensating gate drive signals for controlling switching devices so that dead-time intervals can be inserted without introducing any significant distortion in the output of the converter.
Electric vehicles, such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs), use inverter-driven electric machines to provide traction torque and regenerative braking torque. A typical electric drive system includes a DC power source (such as a battery pack or a fuel cell) coupled by contactor switches to a variable voltage converter (VVC) to regulate a main bus voltage across a main DC linking capacitor. An inverter is connected between the main buses for the DC link and a traction motor in order to convert the DC power to an AC power that is coupled to the windings of the motor to propel the vehicle. A second inverter may also be connected between the main bus and a generator (if present) to provide another power flow path from a prime mover, typically an internal combustion engine, to the DC link.
The inverters include transistor switching devices (such as insulated gate bipolar transistors, or IGBTs) connected in a bridge configuration including a plurality of phase legs. A typical configuration includes a three-phase motor driven by an inverter with three phase legs. An electronic controller turns the switches on and off in order to invert a DC voltage from the bus to an AC voltage applied to the motor, or to rectify an AC voltage from the generator to a DC voltage on the bus. In each case, the inverters are controlled in response to various sensed conditions including the rotational position of the electric machine and the current flow in each of the phases.
The inverter for the motor may preferably pulse-width modulate the DC link voltage in order to deliver an approximation of a sinusoidal current output to drive the motor at a desired speed and torque. Pulse Width Modulation (PWM) control signals applied to the gates of the IGBTs turn them on and off as necessary so that the resulting current matches a desired current.
Because each phase leg of the inverter has a pair of upper and lower switching devices connected across the DC link, it is important that both devices not be conducting (i.e., turned-on) simultaneously. Otherwise, the resulting "shoot-through" of the phase leg could result in damage to the switching devices. A short time interval during which both the upper and lower switching devices of a phase leg are turned off, known as a dead-time, is typically used in connection with PWM control of inverters in order to prevent shoot-through. However, the insertion of a dead-time has resulted in distortion of the output waveform delivered to the load and the introduction of control delays.

Power converter with pre-compensation for dead-time insertion


An image forming apparatus includes an endless belt that is rotated, an image forming device configured to form an image on a recording medium which fed on the endless belt, a cleaning roller configured to be rotated and clean the endless belt, a pair of registration rollers configured to be rotated in a recording medium feeding direction and to feed a recording medium to the image forming device, and a motor configured to rotate in two directions. The image forming apparatus may further include first, second, and third gear mechanisms. The first and second gear mechanisms are configured to switch between transmission and non-transmission of a driving force to the cleaning roller according to rotational direction of the motor. The third gear mechanism is configured to switch between transmission and non-transmission of the driving force to the registration roller according to the rotational direction of the motor.

It has been proposed that various types of image forming apparatuses be provided with an image formation unit configured to form an image on a recording medium using a rotating endless belt. This type of image forming apparatus has been proposed to include a cleaning roller that is configured to rotate in a predetermined direction for cleaning the endless belt or registration rollers that are configured to rotate to feed the recording medium toward the image formation unit when the recording medium is inserted manually. If the image forming apparatus is provided with the cleaning roller, the endless belt soiled during image formation can be cleaned. If the image forming apparatus is provided with the registration rollers, the image formation can be performed on a sheet manually inserted by the user.
When the image forming apparatus is provided with the registration rollers and the cleaning roller, it is proposed that the registration rollers and the cleaning rollers be driven by the same motor, and a clutch, which is configured to switch between transmission and non-transmission of driving force, be disposed on a path connecting to the registration rollers.
A general clutch having a solenoid may be used to switch between the transmission and non-transmission of driving force to the registration rollers. In this case, power should be continuously applied to the solenoid of the clutch for a long time in order to drive the cleaning roller while stopping the registration rollers during, for example, auto registration adjustment for color matching. Thus, the clutch should include a large-sized solenoid that can endure long-duration power application.


A terminal block equipped with a cover includes a cover and a terminal block. The terminal block has pivot plates on two sides. Each pivot plate has a coupling trough. The cover has an axle on one side, to be wedged in the coupling trough, so that the cover may be hinged on one side of the terminal block. The cover may be turned to shield the terminal block. Wedging of the axle in the coupling trough also forms an anchoring effect to position the cover on a correct location relative to the terminal block, so that the cover can fully shield the terminal block, to provide desired covering and protection.

1. Field of Invention
The present invention relates to conductors for communication equipment. More particularly, The present invention relates to a terminal block equipped with a cover that includes a cover hinged on one side of the terminal block and anchored on a correct location to completely cover the terminal block.
2. Related Art
The terminal block is widely used in telecommunication systems to connect signal wires on one location to facilitate maintenance and management. U.S. Pat. No. 3,887,259 discloses such a connecting device, which has a rectangular terminal block made from an insulation material. The terminal block has a plurality of guiding plates on two longer sides that are spaced from one another to allow the signal wires to pass through. The signal wires may be divided according to different signal sources and classified according to their functions. The terminal block further has a plurality of terminals. Each terminal has a narrow slot to clip a signal wire, so that the signal wire and the terminal form an electric connection. The terminals may be connected in advance according to requirements. For instance, two or more terminals may be integrally formed by stamping, so that one end of the terminals is interconnected and the other end of the terminals runs through the bottom of the terminal block and extends outside the top surface of the terminal block. Or different terminals may be connected by jumpers. When there is a need to connect two signal wires, they may be coupled on the connected terminals to form electric connection. Moreover, connection of the signal wires may be expanded from two signal wires to multiple signal wires. For instance, to branch a signal source to a plurality of signal wires, multiple signal wires have to be interconnected, and the signal wires can pass through the same gap between two guiding plates for classification to facilitate identification during repairs and maintenance.
As the terminals are exposed on the top surface of the terminal block, they are easily hit by external articles and result in a shot circuit between the terminals, or result in disconnecting of the signal wires. Hence a cover has to be provided on the top surface of the terminal block to provide shielding and protection. The conventional cover adopts latch coupling, and has an edge or sidewall to engage outer sides of the guiding plates. For instance, U.S. Pat. No. 4,104,703 provides a terminal block cover, which is directly mounted onto a terminal block. It has snap tabs to latch on the top edge of the guiding plate. U.S. Pat. No. 4,898,550 discloses an extruded plastic hinge cover for terminal blocks that has a flexible strip coupled with a adjacent component and a cover. The adjacent component engages the guiding plates. The flexible strip functions like a hinge and the cover can be swiveled relative to the terminal block to cover the terminal block. U.S. Pat. No. 4,697,720 discloses a terminal block cover, which has a hinge mechanism that engages the terminal block's guiding plates, and an axle corresponding to the edge of the cover so that the cover can be swiveled relative to the terminal block.
However, U.S. Pat. Nos. 4,697,720, 4,104,703 and 4,898,550 previously discussed do not have an align mechanism in the longitudinal direction of the terminal block. Hence during installation of the cover on the terminal block, the relative position of the cover and the terminal block has to be adjusted and aligned accurately, to shield and protect all the terminals. A slight deviation could expose the terminals and result in being hit by external articles. As a result, a short circuit between the terminals or disconnecting of the signal wires still could happen.


A ring network of a multicast label switch path scheme includes a plurality of nodes connected to form a ring. Further, a signal input to a first one of the nodes is branched to be transmitted in first and second different directions to a second and a third one of the nodes through a first working path and a second working path, respectively, in the ring network, the second one and the third one of the nodes defining end points of the first working path and the second working path, respectively, from the first one of the nodes, and a first backup path is set from the second one of the nodes to the first one of the nodes in the first direction, and a second back up path is set from the third one of the nodes to the first one of the nodes in the second direction.

Recently, with the improvements of the Ethernet (registered trade mark) and IP technologies, use of IP in the network has been more and more popular. This trend has been popular among network providers, so that the replacement of an SDH (Synchronous Digital Hierarchy) transmission method by a packet transmission method has been started in order to improve the transmission efficiency to respond to an increasing demand of IP traffic of a carrier network and reduce a cost. A difference between the SDH transmission method and the packet transmission method is described below.
The SDH transmission method is a TDM (Time Division Multiplexing) based technology, which means time slots may be occupied (used) when there are no data to be transmitted. On the other hand, in the packet transmission method, when there are no data to be transmitted, another service may use the time slots; therefore the line (use) efficiency may be improved.
In a carrier network, from a viewpoint of operational management, even when a packet transmission method is used, it is required to conduct path management (i.e., static path setting). To fulfill this requirement, a method called an MPLS-TP (Multi Protocol Label Switching-Transport Profile) packet-based transport method has been developed.
FIG. 1 illustrates an example of a ring network employing the MPLS-TP scheme for conducting multicast communications. As illustrated in FIG. 1, nodes N1, N2, N3, N4, N5, N6, N7, and N8 are connected in a ring shape to form a ring network. In the ring network, an LSP#WA is set which is a working LSP (Label Switch Path) set along an "A" direction (clockwise direction) illustrated as a solid line between the node N1 and the node N5.
Also, an LSP#WB is set which is a working LSP (Label Switch Path) set along a "B" direction (counterclockwise direction) illustrated as a solid line between the node N1 and the node N7.
In this case, a signal added (inserted) at the node N1 is duplicated and branched into two. As a result, one of the branched signals is distributed (transmitted) from the node N1 to the nodes N2, N3, N4, and N5 in this order and dropped (extracted) at the nodes N2, N4, and N5. Similarly, the other of the branched signals is distributed from the node N1 to the nodes N8 and N7 in this order and dropped (extracted) at the nodes N8 and N7.
When a failure (typically, a loss of continuity) occurs in the ring network of FIG. 1, it is necessary to respond to the failure to make it possible to use the ring network (hereinafter may be referred to as "relieve" or "backup").
For example, to "relieve" the LSP#WA in the A direction (clockwise direction), an LSP#PB illustrated as the dotted line along the B direction (counterclockwise direction) is set. Also, to relieve the LSP#WB in the B direction (counterclockwise direction), an LSP#PA illustrated as the dotted line along the A direction (clockwise direction) is set.
Generally, by monitoring the reception of a CCM (Continuity Check Message) packet of an OAM (Operation Administration and Maintenance) packet which is a monitor/control packet of the working and backup (preliminary) LSP at nodes N5 and N7 at terminals points, a failure is relieved ("backuped") separately for each of the LSPs.
There has been known a technique in which in a ring-type network, in multicast communications, the entry information indicating the nodes relevant to the multicast communications is shared among the node transmitting data and the nodes receiving the data. Then, the transmitting node determines the transmission direction along which the multicast data are to be transmitted by referring the entry information and topology information, and, on the other hand, the receiving nodes discard (destroy) the multicast data when determining that there is no farther receiving node to received the multicast data beyond in the transmission direction (see, for example, International Publication Pamphlet No. WO2004/064335).
Further, there has been known a technique in which communications signals are transmitted from an ingress node to plural egress nodes along two or more paths on a network; a primary path through which a multicast communication signal is transmitted in advance along a communication link before a failure occurs in the network and a backup path through which the multicast communication signal is transmitted along a communication link are set; when a failure occurs a multicast communication signal is transmitted on the primary path and a copy of the multicast signal is transmitted on the backup path (see, for example, Japanese National Publication of International Patent Application No. 2010-515314).
Further, there has been known a technique in which a multi-point logical path is set in two systems (i.e., a working system and a backup system). The multi-point logical path is the path in which a frame transmitted from a transmission terminal node is not only transmitted to multicast frame receiving terminal nodes but also transmitted back to the transmission terminal node after transmitting along the ring so that the frame is terminated by the transmission terminal node as well. Then, a node detecting a failure transmits a forward failure report frame to the multicast (multi-point) logical path where the failure occurs, and the transmission terminal node receiving the forward failure report frame stops using the multicast (multi-point) logical path and transmits the frame by using a path that no forward failure report frame is received from yet (see, for example, Japanese Laid-open Patent Publication No. 2007-282153).
Further, there has been known a technique in which the transmission terminal node hierarchically divides the transmission frame into two, appends a header including plural addresses and the terminal No. of the terminal which becomes the end terminal, and separately transmits in both directions of the ring transmission path. By doing this, a multicast communication having higher confidentiality and band use efficiency in the ring transmission path is achieved (see, for example, Japanese Laid-open Patent Publication No. 2007-53484).

This patent is subject to a terminal disclaimer.

Network, network fault recovery method, and node device


Approaches for a magnetic write head having a stacked coil architecture. Embodiments utilize the better process control capability available with thin films' thicknesses, compared to the control capability of vertical gap-filling processes, which provides for better scalability to shorter yoke length magnetic write heads, which are faster at writing data bits than are magnetic write heads having a longer yoke length.

A hard-disk drive (HDD) is a non-volatile storage device that is housed in a protective enclosure and stores digitally encoded data on one or more circular disks having magnetic surfaces (a disk may also be referred to as a platter). When an HDD is in operation, each magnetic-recording disk is rapidly rotated by a spindle system. Data is read from and written to a magnetic-recording disk using a read/write head which is positioned over a specific location of a disk by an actuator.
A read/write head uses a magnetic field to read data from and write data to the surface of a magnetic-recording disk. As a magnetic dipole field decreases rapidly with distance from a magnetic pole, the distance between a read/write head, which is housed in a slider, and the surface of a magnetic-recording disk must be tightly controlled. An actuator relies in part on a suspension's force on the slider and on the aerodynamic characteristics of the slider air bearing surface (ABS) to provide the proper distance between the read/write head and the surface of the magnetic-recording disk (the "flying height") while the magnetic-recording disk rotates. A slider therefore is said to "fly" over the surface of the magnetic-recording disk.
FIG. 2 is a cross-sectional side view of a conventional write head. Write heads make use of the electricity flowing through a coil 202 in the write head 200, which produces a magnetic field. One type of coil design is referred to as a helical coil because it wraps around the write poles, i.e., main pole 204, in a helical shape. Such a write head includes a helical write coil having upper coil portions 202a, 202b, 202c that pass above the write pole and lower coil portions 202d, 202e, 202f that pass below the write pole. The upper and lower coil portions are connected with one another by connection studs. Electrical pulses are sent to the write head, with different patterns of positive and negative currents. The current in the coil of the write head induces a magnetic field across the gap between the head and the magnetic disk, which in turn magnetizes a small area on the recording medium.
A perpendicular magnetic recording (PMR) system records data as magnetizations oriented perpendicular to the plane of the magnetic-recording disk. The magnetic disk has a magnetically soft underlayer covered by a thin magnetically hard recording layer. The perpendicular write head has a write pole (main pole 204) with a very small cross section at the pole tip 208a, tapered down from the cross section along the length of the yoke 208b, a lower return pole 206, and an upper return pole 218 having a much larger cross section along the length. Also shown in FIG. 2 is a wrap-around shield 209, for assisting in focusing the magnetic field emitting from pole tip 208a, and a back gap 203. A strong, highly concentrated magnetic field emits from the write pole in a direction perpendicular to the magnetic disk surface, magnetizing the magnetically hard top layer. The resulting magnetic flux then travels through the soft underlayer, returning to the return pole where it is sufficiently spread out and weak that it will not erase the signal recorded by the write pole when it passes back through the magnetically hard top layer on its way back to the return pole.
Advanced PMR writers demand high data rate write heads, especially for advanced server products. For high data rate performance, a shorter yoke length write head is faster in writing data bits, for the same total write current. Thus, the shorter the yoke length, and the higher the total current going through the coil turns, the faster the write head. However, in conventional write heads, yoke length reduction is challenging in part because manufacturing conventional coil structures involves filling in insulating material into the gaps 210a, 210b and 210c, 210d between coil turns 202a, 202b, 202c and 202d, 202e, 202f, respectively. As the yoke length decreases, the height-to-width aspect ratio of such gaps typically increases, making the insulator fill process all the more problematic.

Magnetic write head having a stacked coil architecture for high data rate performance


An exemplary embodiment providing one or more improvements includes an endoscope connector for connecting any given one of a plurality of working assemblies to an imaging assembly.

Endoscopes have continued to evolve since their inception in the 1800's because of their utility and versatility. Medical endoscopes can be used for performing medical procedures which can include viewing and manipulating tissues in body cavities. While relatively large endoscope probes can be used in existing body channels for some types of procedures, other relatively small endoscope probes can be used to perform intricate surgery through relatively small incisions. Because of these relatively small incisions, patient recovery time and surgical complications can be significantly reduced when compared to similar procedures using non-endoscopic techniques.
A conventional endoscope can have a probe with a distal end for insertion through an incision into a body cavity. The probe can be rigid or flexible and can include one or more channels that extend from the distal end to a proximal end. The probe can include an imaging fiber bundle that is used in conjunction with a viewing apparatus for viewing objects in a field of view in the body cavity. The probe can also include one or more illumination fibers arranged to transfer light from an illumination source to illuminate the field of view, and can include a working channel for guiding tools through the probe into the body cavity for performing surgical techniques.
A challenge in medical endoscopes is economical manufacturing and utilization. A typical medical endoscope can cost thousands of dollars. Historically, surgical endoscopes have been relatively expensive and have been sterilized and reused to avoid the cost of having to replace the instrument after every procedure. Sterilization and reuse can be economical and safe for endoscopes having relatively large probes. On the other hand, Applicants submit that effective and economical sterilization techniques have not been realized for a clinical setting for endoscopes having smaller channels that are on the order of 1 mm or less. Because of this, some smaller endoscopes are disposed of following surgery which can increase the cost of the procedure.
Applicants recognize that endoscopy costs can be significantly decreased if the working assembly of the endoscope can be removed from the imaging assembly. The working assembly can be disposable and can have as short an imaging fiber as practical, which can help decrease unit cost for the disposable working assembly. In order to achieve this however, it can be necessary to have a connector which connects the disposable, single-use working assembly to the imaging assembly through which images may be transferred. While methods of connection exist, they are typically bulky and do not lend themselves to quick connection, such as by snapping into place, nor are they small and light. Applicants recognize that useful connector embodiments include features such as, for example: a small size in order to allow it, along with the working assembly of the endoscope, to be easily held and manipulated by the practitioner; and extremely tight positional accuracy after thousands of connections. None of these useful embodiments are believed to be available with conventional endoscope devices.
The present invention provides a highly advantageous system and method that are submitted to resolve the foregoing problems and concerns while providing still further advantages, as described hereinafter.

Endoscope connector method and apparatus


A method and apparatus for real-time filtering of a position error signal in a servo system of a disk drive. Pre-calculated periodic components of the position error signal (PES) are used as future values in a real-time filter, preferably a real-time recursive median filter. This minimizes the amount of time-lag between obtaining the raw PES measurement from the disk surface and the providing the corresponding filtered PES output. This reduced time-lag minimizes the effect on the phase margin (PM) and results in improved servo stability. The invention can be used not only in servo systems in disk drives, but also in servo systems of other mechanical moving storage devices and in servo systems of rotating mechanical machinery in general, where the signal to be filtered may be a position error, velocity error, acceleration error, and the like.

1. Field of the Invention
The invention relates generally to a method and apparatus for real-time filtering of position error signals (PES) in disk drive servo systems that minimizes the time delay shift between the raw position error signal and the filtered output.
2. Description of the Prior Art
Computers often include mechanical moving storage devices, e.g., disk or tape drive units, having media on which data can be written and from which data can be read for later use. Disk drive units that incorporate stacked, commonly rotated, rigid magnetic disks are used for storage of data in magnetic form on the disk surfaces. Data is recorded in concentric, radially spaced data information tracks arrayed on the surfaces on the disks. Transducer heads driven in a path toward and away from the drive axis write data to the disks and read data from the disks.
All disk drive units must have a method to position each transducer head over the proper radial location to write a track and again, to position it very close to the same location to read the track. With the higher level performance disk drive units, e.g., those that use a voice coil type of actuator, a feedback mechanism must be provided to locate and stably hold the head on a given track. Typically, track accessing and track following are provided utilizing a magnetically prewritten pattern on the disk surfaces in the disk drive unit. A dedicated servo system employs only one surface of one of the disks in the disk drive on which is pre-written all the magnetic servo patterns used for position error information required by the tracking and track accessing servo. A sector servo system, in contrast, uses small portions (typically, 10-15%) of each of the data surfaces for magnetically prewritten servo patterns. These servo patterns are written on the disk surfaces within evenspaced radial servo sectors that are interlaced with data sectors. The radial servo sectors provide tracking and track access information for all concentric data tracks written on the particular disk surface. A hybrid servo system uses both dedicated servo and sector servo to obtain the advantages of each type of servo system.
Precise tracking and fast accessing of the transducing heads to any track are crucial to high performance disk drives. These requirements call for a closed loop servo system that has high degree of servo stability. A high degree of servo stability means that the radial motions of the transducing heads are smooth and not jerky, so that the transducing heads do not waver back and forth. In a similar situation, an automobile with worn shock absorbers will waver up and down when the wheels hit a bump on the road surface making steering difficult, while an automobile with very stiff shock absorbers will transmit the shock of the bump to the driver making the drive harsh. An automobile with a high degree of servo stability, on the other hand, strikes a balance between the two extremes. One measure of servo stability is the phase margin (PM). The PM may be defined as a measure of the additional phase lag or time delay that can be tolerated in the servo loop before instability results. Servo instability in a disk drive is a catastrophic event. It will cause the transducing heads to waver radially back and forth with increasing amplitudes on the disk surface until the disk drive eventually self-destructs.
The servo system controlling the tracking and accessing of the transducing heads in disk drives uses a position error signal (PES) obtained by decoding prerecorded magnetic servo patterns on the disk surfaces. Noise in the decoded PES is a common problem in disk drives as disclosed in U.S. Pat. No. 4,412,165, issued to Case et al. One noise reduction method using common averaging provided by an analog linear filter is discussed in U.S. Pat. No. 4,380,034, issued to Krake. U.S. Pat. No. 4,982,297, issued to Tsujisawa, uses a real-time linear recursive digital filtering method for compensating for erroneous detection of PES. Real-time digital recursive filters, such as that used on the Tsujisawa patent, derive the next output from a linear, weighted sum of previously stored filter input values and output values.
Another technique for removing noise from the PES is simply to "ignore" PES samples that seem to be erroneous. Rather than utilizing a real-time linear filter that repetitively averages the last M position error signal (PES) samples, a real-time M-point median filtering method may be used. Here, the value M is typically a small odd integer. A real-time M-point median filter is a nonlinear filter that will pick the middle value from the last M samples. For example, the middle or median value of the last three PES samples could be extracted using a real-time 3point median filter. A median filter is a nonlinear filter that will pick the middle value from an odd number of samples. The use of a real-time median filter in connection with the position error signal (PES) in disk drives has been disclosed in T. Makansi, "Median Filtering of Position Error Signals in a Data Recording Disk File," IBM Technical Disclosure Bulletin, Vol. 29, No. 12, May 1987, pp. 5239-5240. However, the Makansi disclosure only teaches finding the median of three or more sampled values of past PES measurement values. Any real-time filter used in a closed loop servo system, no matter whether linear (such as those disclosed in the Krake and Tsujisawa patents discussed in the previous paragraph) or nonlinear (such as that disclosed in the Makansi patent), that uses only past PES measurement values as inputs in the filtering operation adversely decreases the phase margin (PM). This occurs because an additional time lag is added to the servo system, and the servo tracking system is therefore subject to reduced stability.
Other methods for improving the tracking capability of servo systems in the presence of PES noise, e.g., caused by disk runout and the like, include the use of feedforward techniques in the disk drive servo. The basis for such feedforward techniques is that a variable portion of the dynamic PES can be anticipated. Thus, near term future behavior of the PES can be predicted with some accuracy. The PES is considered to consist of two components, the repeatable or periodic PES and the non-repeatable or non-periodic PES, being synchronous or non-synchronous with the disk rotation, respectively. The PES samples for a given track on each disk surface are averaged per sector over several revolutions of the disk pack. The resultant averaged PES samples, often referred to as the repeatable PES, are used by the servo system to anticipate synchronous motions of the head. The non-repeatable PES is obtained by subtracting the "raw" PES from the repeatable PES. U.S. Pat. No. 4,412,165 issued to Case et al.; U.S. Pat. No. 4,536,809 issued to Sidman; U.S. Pat. No. 4,594,622 issued to Wallis; and U.S. Pat. No. 4,616,276 issued to Workman, teach various algorithmic methods of deriving feedforward signals in connection with disk drives.
The problem with all of the prior art discussed above is that it does not provide an effective PES noise reduction method that has minimal impact on the required servo tracking stability. All noise filtering methods that use only past samples of the PES will adversely reduce the phase margin, and thereby reduce servo stability and cause poor tracking.

Method and apparatus for real-time filtering of a position error signal for a disk drive servo system

International Business Machines Corporation


The present invention provides an apparatus and method for describing (603) objects (1604) to be shared over a network (1502) by a plurality of network-connected terminals (1501, 1504, 1506) by means of ASCII instructions (201, 202, 206) and for the compiling (103, 104) thereof within an instructions set (208) executable by said network-connected terminals. Each of said network-connected terminals (1501, 1504, 1506) is equipped with visual display means, processing means, storage means and memory means, wherein said memory means is configured to store (1603) said executable instructions set (208) and said processing means is configured by said executable instruction set (208) to manage the duplication of said described objects (1604).

1. Field of the Invention
The present invention relates to a method of describing data to be shared by a plurality of network-connected terminals over a network, within a set of program instructions.
2. Description of the Related Art
Methods to describe data or objects within program instructions executable by terminals equipped with processing means are well known. The development of higher-level programming languages (HLPLs) such as C or C++, has lead to an increased efficiency of processor usage for any given application programmed with this type of language, and also resulted in productivity improvements in terms of application development indeed, an additional benefit of said HLPS, also known as object-oriented programming, is the ability for programmers to develop reusable software components, or portions of a set of programming instructions.
With electronic communication in leisure or business activities becoming increasingly important, most programs utilised within the scope of those activities are today required to share objects over networks, such as local area networks or the Internet. In this context, object-oriented programming traditionally resorts to message-based networking solutions, wherein programmers implement program instructions pertinent to the passing of packets of data between network sockets according to various internet protocols. The implementation of the object sharing portion of instructions within a set of program instructions is traditionally fairly expensive as much development time is spent writing said networking instructions in order for those to accurately manage the sharing of existing classes of objects, which are usually implemented at first within said program instructions set for local processing.
The implementation of networking instructions requires extensive further testing of the functionality of the overall program over networks prior to commercial release in addition to the initial testing of the program instructions for programming faults, which is traditionally executed locally. Said expenses are further compounded by the number of independent types of user terminal, or 'platforms', a program developer wishes to publish its program instructions for, as said platforms traditionally require specifically-adapted instantiations of the same instructions set and thus artificially increase the development time and resources required to generate the executable instructions set.
The present invention provides a higher-level programming language (HLPL) easily comprehensible by those skilled in the art, which describes objects to be shared by network-connected terminals at the onset of the writing of a set of program instructions, wherein network instructions are embedded within the object classes and thus do not require additional network-specific instructions to be implemented within the main program instructions set. This solution facilitates testing of the overall program over networks throughout the development of the project instead of said testing being carried out at the end. The platform independent characteristic of the HLPL according to the invention further reduces the financial overhead generated by a multiple-platform commercial release, as the objects to be shared need be described according to said HLPL only once.


The present disclosure discloses an antenna device, which comprises an array antenna and a power divider. The array antenna comprises a plurality of antenna units, and each of the antenna units comprises a conductive sheet engraved with a groove topology pattern, conductive feeding points and a feeder line. The power divider is adapted to divide a baseband signal into a plurality of weighted signals and then transmit the weighted signals to the antenna units arranged in an array via the conductive feeding points respectively. By arraying the antenna units and using the beam forming method, the directionality of the antenna can be designed as needed through phase superposition between the antenna units; and then, a reflective metal plate is provided on the back side of the antenna so that a back lobe of the antenna is compressed. In this way, the miniaturized antenna array can obtain a high directionality.

With advancement of the semiconductor manufacturing processes, requirements on the integration level of modern electronic systems become increasingly higher, and correspondingly, miniaturization of components has become a problem of great concern in the whole industry. However, unlike integrated circuit (IC) chips that advance following the Moore's Law, radio frequency (RF) modules which are known as another kind of important components in the electronic systems are very difficult to be miniaturized. An RF module mainly includes a mixer, a power amplifier, a filter, an RF signal transmission component, a matching network and an antenna as key components thereof. The antenna acts as a transmitting unit and a receiving unit for RF signals, and the operation performances thereof have a direct influence on the operation performance of the overall electronic system. However, some important indicators of the antenna such as the size, the bandwidth and the gain are restricted by the basic physical principles (e.g., the gain limit under the limitation of a fixed size, and the bandwidth limit). The limits of these indicators make miniaturization of the antenna much more difficult than miniaturization of other components; and furthermore, due to complexity of analysis of the electromagnetic field of the RF component, even approximately reaching these limits represents a great technical challenge.
Meanwhile, as the modern electronic systems become more and more complex, the multi-mode services become increasingly important in wireless communication systems, wireless accessing systems, satellite communication systems, wireless data network systems and the like. The demands for multi-mode services further increase the complexity of the design of miniaturized multi-mode antennae. In addition to the technical challenge presented by miniaturization, multi-mode impedance matching of the antennae has also become a technical bottleneck for the antenna technologies. On the other hand, the rapid development of multiple input and multiple output (MIMO) systems in fields of wireless communications and wireless data services further heightens the requirement on miniaturization of antennae and, meanwhile, requires availability of a desirable isolation degree, desirable radiation performances and desirable interference immunity. However, the communication antennae of conventional terminals are designed primarily on the basis of the electric monopole or dipole radiating principles, an example of which is the most common planar inverted F antenna (PIFA). For a conventional antenna, the radiating operation frequency thereof is positively correlated with the size of the antenna directly, and the bandwidth is positively correlated with the area of the antenna, so the antenna usually has to be designed to have a physical length of a half wavelength. Besides, in some more complex electronic systems, the antenna needs to operate in a multi-mode condition, and this requires use of an additional impedance matching network design at the upstream of the infeed antenna. However, the additional impedance matching network adds to the complexity in design of the feeder line of the electronic systems and increases the area of the RF system and, meanwhile, the impedance matching network also leads to a considerable energy loss. This makes it difficult to satisfy the requirement of a low power consumption in the design of the electronic systems. Especially, for indoor directional antenna designs, the antenna gain cannot well satisfy the user's needs, and the directionality is not so good.

High-Tech Industrial Estate, Nanshan District, Shenzhen, Guangdong

KUANG-CHI INSTITUTE OF ADVANCED TECHNOLOGY


A process transmitter includes a transmitter housing and a liquid detector coupled to the transmitter housing. The liquid detector includes a temperature sensor configured to generate signals indicative of a presence of liquid within the transmitter housing. The process transmitter also includes a controller coupled to the liquid detector configured to receive the generated signals, determine the presence of liquid within the transmitter housing based on the received signals, and generate an output indicative of the determined presence of liquid within the transmitter housing.

Industrial process control systems are used to monitor and control industrial processes used to produce or transfer fluids or the like. In such systems, it is typically important to measure "process variables" such as temperatures, pressures, flow rates, etc. Process control transmitters are used to measure such process variables and transmit information related to the measured process variable back to a central location such as a central control room.
For example, one type of process variable transmitter is a pressure transmitter which measures process fluid pressure and provides an output related to the measured pressure. This output may be a pressure, a flow rate, a level of a process fluid, or other process variable that can be derived from the measured pressure.
In operation, process control transmitters may be mounted to a variety of processes within different environments. In one example, process control transmitters may be field mountable which, in turn, can subject the process control transmitters to high humidity, rain, flooding, etc. In turn, this can damage electrical components of the process control transmitters. For example, improper installation of a process control transmitter can result in loose covers and/or leaky conduits and cable glands which can introduce environmental moisture into a housing of the process control transmitter. Introduction of moisture often leads to an output error and, over time, can even lead to a failure of the transmitter.
To detect a presence of moisture within the housing/terminal block of the process control transmitters, current attempts often necessitate a user first removing the transmitter from a control loop and manually running a multi-step diagnostic operation on the transmitter. However, this is often reactive indicating an error only after a transmitter output has experienced an output shift. Additionally, other examples often include using electrical conductivity (resistive or capacitive) to detect a presence of moisture. However, these methods are often unreliable and sensitive to contamination, leakage currents and false alarms. For example, once contaminated, various sensors can become extremely sensitive to humidity causing the sensors to falsely detect water when no water is present.

Process transmitter with thermal fluid detection for decreasing damage to the process transmitter components


A method for facilitating cellular communication for and among a plurality of native cellular handsets in a hybrid cellular communication network that has a cellular exchange subsystem and a private mobile-services switching center. In this embodiment, the cellular exchange subsystem is coupled to a public cellular , and the native cellular handsets represent handsets that subscribe to the hybrid cellular communication network. The hybrid cellular communication network further facilitates cellular communication between a nonnative cellular handset and the public cellular network, with the nonnative cellular handset being a cellular handset that does not subscribe to the hybrid cellular communication network. In this embodiment, the method includes the steps of receiving access request data, using a cellular exchange subsystem, and ascertaining whether the access request data originates from one of the plurality of native cellular handsets or from the nonnative cellular handset. If the access request data originates from the one of the plurality of native cellular handsets, the method then passes data relating to the access request to the private mobile-services switching center for completing a first call path from the one of the plurality of native cellular handsets. On the other hand, if the access request data originates from the nonnative cellular handset, the method passes data relating to the access request data to the public cellular network for completing a second call path between the nonnative cellular handset and the public cellular network.

This is a continuation-in-part of commonly assigned co-pending U.S. patent Ser. No. 08/435,709, entitled "Cellular Private Branch Exchange," filed May 4, 1995, now U.S. Pat. No. 5,734,699.
The following co-pending U.S. patent applications are incorporated herein by reference for all purposes:
"Cellular Private Branch Exchange," filed May 4, 1995, U.S. Pat. No. 5,734,699.
"Cellular Communication Network Having Intelligent Switching Nodes," filed May 4, 1995, U.S. Ser. No. 08/435,838, now U.S. Pat. No. 5,577,029.
"Configuration-Independent Methods And Apparatus For Software Communication In A Cellular Network," filed on even date, U.S. Ser. No. 08/730,652, Attorney's Docket No. WAVEP005 and the earlier filed provisional application entitled "Configuration-Independent Methods And Apparatus For Software Communication In A Cellular Network" filed Nov. 10, 1995 Application No. 60/006,455 by inventors Priscilla Marilyn Lu and Timothy Richard White from which that application claims priority under 35 U.S.C. 119(e).
"Spread Spectrum Communication Network Signal Processor," filed on May 4, 1995, Ser. No. 08/434,554, now U.S. Pat. No. 5,682,403.
"Cellular Base Station With Intelligent Call Routing," filed on May 4, 1995, Ser. No. 08/434,598, now U.S. Pat. No. 5,734,979.
"Spread Spectrum Communication Network With Adaptive Frequency Agility," filed on May 4, 1995, Ser. No. 08/434,597, now U.S. Pat. No. 5,781,582.
For ease of reference, a glossary of terms and abbreviations is provided herewith as Appendix A.
The present invention relates generally to cellular communications networks. More particularly, a private cellular exchange network that has the ability to optionally act as a base station subsystem in an even larger network to permit nonnative handsets to use the local network's resources is described.
Presently, there are a variety of wired and wireless private branch exchanges (PBX's) that are commercially available. By way of example, FIG. 1 diagrammatically illustrates a conventional wireless private branch exchange system (wPBX) 100. As seen therein, the wPBX 100 is coupled to one or more external lines 102, which typically couple the wPBX to a public network. The wPBX 100 is arranged to control a plurality of base units 108 and is coupled to the base units by fixed wiring 104. It should be appreciated that the wPBX may control any number of base units, although for simplicity of illustration, only one such base units is explicitly shown. Each base unit 108 includes an antenna 110 to facilitate cordless communication between the base unit and one or more associated cordless handsets 112. In the typical wireless PBX system, each base unit 108 controls a pair of cordless handsets.
Although the described wPBX system offers the advantages associated with cordless handsets, there are several significant limitations. To begin with, in wireless PBX systems, the telephone number is associated with a given frequency, which is in turn associated with a fixed port on the PBX. Therefore, from the point of view of the PBX, the cordless handset is "fixed" to a PBX port just as in normal wired PBX's. Because of this, even when the wPBX is interconnected in a wPBX network, a cordless handset cannot be taken to another location controlled by another wPBX unit and still able to make and receive calls associated with its assigned phone number without having to undergo administrative moves and changes, e.g. reprogramming the wPBX itself. Consequently, the range of each cordless handset is limited by the range of the base unit with which it is specifically associated.
Further, neither the cordless handsets nor the prior art wireless PBX's have any roaming or hand-off capabilities. To illustrate, consider the situation when cordless handset 112 travels (i.e. roams) out of the range of base unit 108 during use into an area controlled by another wireless PBX. In such an event, the communications data stream is nevertheless cut off. Thus, from the perspective of wPBX 100 or the public network to which link 102 is coupled, the fact that cordless handsets 112 and 114 communicate with base 108 in a cordless manner is irrelevant. Since there are no roaming and no hand-off capabilities between base units or wPBXs, the manner in which cordless handsets 112 are coupled to base unit 108 does not provide the user with any additional advantages besides the fact that cordless handsets 112 and 114 may be made cordless inside the range defined by the transceiver within base unit 108.
Another disadvantage of typical wireless PBX systems involves their use of low-power and proprietary transceivers, which significantly limit the range over which a cordless handset can be taken from its associated base unit. By way of example, the radius of operation of the cordless handsets is typically limited to around 200 meters. Further, when calls are made among cordless handsets of the same wPBX, the call paths are typically switched, or cross-connected, at the wPBX level. In other words, the actual switching is centralized at the wPBX even if cordless handsets of the same base unit desire to communicate among themselves, e.g., between cordless handsets 112 and 114. This is because the switching function can not be delegated from wPBX unit 100 down to subsystems below it in the hierarchy, e.g., to base 108. When calls are always switched at the highest level of the hierarchy, call paths to and from the cordless handsets are oftentimes unnecessarily back hauled all the way to the highest level, i.e., the wPBX, although it may be more efficient to cross connect closer to the cordless handsets, i.e. at a base unit at a lower level of the hierarchy.
Another disadvantage of the prior art wireless PBX's relates to its inablility to authenticate calling and destination handsets to ascertain whether the handsets currently in communication with the system is in fact the intended ones. This is because any prior wireless handset that happens to be on the same frequency and utilizes the same protocol as the base unit can intercept a given call. Because of this limitation, there is no way in the prior art wPBX to define and discriminate among the particular handsets that are authorized to use the resources of the wireless system to make and receive calls from those that merely have the technical ability, but not authorized, to use those resources. For the purpose of the present disclosure, the former is regarded as native handsets and the latter nonnative ones.
It should be appreciated that in some applications, it would be desirable to provide a system which discriminates between native and nonnative handsets and permits nonnative handsets that enter an area controlled by a private exchange system to utilize the resources of that private exchange system to seamlessly connect to a public network.

Hybrid cellular communication apparatus and method

Interwave Communications International, Ltd.


After a polycrystalline silicon film (5) is formed on a semiconductor substrate via an insulating film for a gate insulating film (step S1), an organic antireflection film (21) is formed on the polycrystalline silicon film (5) (step S2), and a resist pattern (22) is formed on the antireflection film (21) (step S3). Then, a passivation film (23) is deposited on the antireflection film (21) so as to cover the resist pattern (22) by plasma using fluorocarbon gas while a bias voltage is being applied to the semiconductor substrate (step S4). Then, the passivation film (23) and the antireflection film (21) are etched by plasma using gas containing oxygen gas (step S5). Thereafter, the polycrystalline silicon film (5) is etched using the resist pattern (22) with reduced line edge roughness as an etching mask to form a gate electrode (step S6).

As a method for forming a gate electrode of a MISFET in a semiconductor device, there is a dry etching method using a resist pattern as an etching mask. The dry etching method is a technique for making process gas introduced in a vacuum case become plasma utilizing high-frequency power applied externally to cause reactive radical or ion produced in the plasma to react on a wafer at high precision, thereby selectively processing a silicon film which is a film to be processed on mask material or a gate insulating film as typified by resist.
Japanese Patent Application Laid-Open Publication No. 2002-289592 (Patent Document 1) describes a technique where a constitution for etching and removing a antireflection film of an opening portion of resist using etching gas containing halogen substitution of carbon hydride as component is adopted, so that when the antireflection film is etched, carbon component in the halogen substitution of carbon hydride is formed as carbonaceous deposit on sidewalls of the opening portion of the resist which is subjected to reduced ion irradiation and sidewalls of an opening portion which is formed according to the etching of the antireflection film, and the deposit serves as a sidewall passivation film, so that lateral spreading of the opening portion of the resist and the opening portion of the antireflection film due to etching is suppressed, thereby enabling anisotropic etching of the antireflection film.
Japanese Patent Application Laid-Open Publication No. 2000-164571 (Patent Document 2) describes a technique regarding a contact hole forming method including a step of forming an insulating film (an interlayer insulating film) on a conductive layer (a semiconductor substrate), a step of forming a resist film on the insulating film, a step of performing exposure and development of the resist film for providing an opening in the resist film, a step of performing a first etching utilizing the resist film as a mask to remove at least a portion of the insulating film while depositing reaction product of etching gas on the resist film surface, and a step of performing a second etching different in etching condition from the first etching to open a contact hole reaching the conductive layer.
Japanese Patent Application Laid-Open Publication No. 10-4084 (Patent Document 3) describes a technique for achieving etching excellent in anisotropy by, after forming a resist film on a metal film on a substrate in a first step, patterning the resist film by lithography technique to form a resist pattern, and after forming a passivation film on a surface of the resist pattern by plasma process using gas of fluorocarbon based in a second step, etching the metal film using the resist pattern on which the passivation film has been formed as an etching mask in a third step.
Japanese Patent Application Laid-Open Publication No. 11-195641 describes a technique of alternately performing an etching step using SF6 gas and a deposition step using C4F8 plural times to form a deep groove in silicon by high-rate etching using silicon oxide as a mask.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2002-289592
Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2000-164571
Patent Document 3: Japanese Patent Application Laid-Open Publication No. 10-4084
Patent Document 4: Japanese Patent Application Laid-Open Publication No. 11-195641

Method for smoothing a resist pattern prior to etching a layer using the resist pattern


A “dual” personal key/token is disclosed. The “dual” personal key is useful for installing drivers and other command interfaces which allow the personal key to be coupled to and used with a host computer. In a first embodiment, the personal key operates as a USB hub, and reports two devices, a storage device and a personal key, to the host computer. In a second embodiment presents a single device, and different portions of the personal key are activated as required.

1. Field of the Invention
The present invention relates to computer peripherals, and in particular to a personal key storing installation software.
2. Description of the Related Art
In the last decade, the use of personal computers in both the home and in the office have become widespread. These computers provide a high level of functionality to many people at a moderate price, substantially surpassing the performance of the large mainframe computers of only a few decades ago. The trend is further evidenced by the increasing popularity of laptop and notebook computers, which provide high-performance computing power on a mobile basis.
The widespread availability of personal computers has had a profound impact on interpersonal communications as well. Only a decade ago, telephones or fax machines offered virtually the only media for rapid business communications. Today, a growing number of businesses and individuals communicate via electronic mail (e-mail). Personal computers have also been instrumental in the emergence of the Internet and its growing use as a medium of commerce.
While certainly beneficial, the growing use of computers in personal communications, commerce, and business has also given rise to a number of unique challenges.
First, the growing use of computers has resulted in extensive unauthorized use and copying of computer software. costing software developers substantial revenue. Although unauthorized copying or use of software is a violation of the law, the widespread availability of pirated software and enforcement difficulties have limited the effectiveness of this means of preventing software piracy.
Software developers and computer designers alike have sought technical solutions to attack the problem of software piracy. One solution uses an external device known as a hardware key, or "dongle" coupled to an input/output (I/O) port of the host computer.
While the use of such hardware keys is an effective way to reduce software piracy, to date, their use has been substantially limited to high value software products. Hardware keys have not been widely applied to popular software packages, in part, because the hardware keys are too expensive, and in part, because there is a reluctance on the part of the application program user to bother with a hardware key whenever use of the protected program is desired. Also, in many cases, the hardware keys are designed for use with only one application. Hence, where the use of multiple applications on the same computer is desired, multiple hardware keys must be operated at the same time.
While it reflects a tremendous advance over telephones and facsimile machines, e-mail also has its problems. One of these problems involves security. Telephone lines are relatively secure and a legally sanctioned way to engage in the private transmission of information, however, e-mails are generally sent over the Internet with no security whatsoever. Persons transmitting electronic messages must be assured that their messages are not opened or disclosed to unauthorized persons. Further, the addressee of the electronic message should be certain of the identity of the sender and that the message was not tampered with at some point during transmission.
Although the packet-switching nature of Internet communications helps to minimize the risk of intercepted communications, it would not be difficult for a determined interloper to obtain access to an unprotected e-mail message.
Many methods have been developed to secure the integrity of electronic messages during transmission. Simple encryption is the most common method of securing data. Both secret key encryption such as DES (Data Encryption Standard) and public key encryption methods that use both a public and a private key are implemented. Public and private key encryption methods allow users to send Internet and e-mail messages without concern that the message will be read by unauthorized persons or that its contents will be tampered with. However, key cryptographic methods do not protect the receiver of the message, because they do not allow the recipient to authenticate the validity of the public key or to validate the identity of the sender of the electronic message.
The use of digital certificates presents one solution to this problem. A digital certificate is a signed document attesting to the identity and public key of the person signing the message. Digital certificates allow the recipient to validate the authenticity of a public key. However, the typical user may use e-mail to communicate with hundreds of persons, and may use any one of several computers to do so. Hence, a means for managing a number of digital certificates across several computer platforms is needed.
Internet commerce raises other challenges. Users seeking to purchase goods or services using the Internet must be assured that their credit card numbers and the like are safe from compromise. At the same time, vendors must be assured that services and goods are delivered only to those who have paid for them. In many cases, these goals are accomplished with the use of passwords. However, as Internet commerce becomes more commonplace, customers are finding themselves in a position where they must either decide to use a small number of passwords for all transactions, or face the daunting task of remembering multiple passwords. Using a small number of passwords for all transactions inherently compromises security, since the disclosure of any of the passwords may lead to a disclosure of the others. Even the use of a large number of passwords can lead to compromised security. Because customers commonly forget their password, many Internet vendors provide an option whereby the user can be reminded of their password by providing other personal information such as their birthplace, mother's maiden name, and/or social security number. This feature, while often necessary to promote Internet commerce, severely compromises the password by relying on "secret" information that is in fact, publicly available.
Even in cases where the user is willing and able to keep track of a large number of passwords, the password security technique is often compromised by the fact that the user is inclined to select a password that is relatively easy to remember. It is indeed rare that a user selects a truly random password. What is needed is a means for generating and managing random passwords that can be stored and recalled for use on a wide variety of computer platforms.
Internet communications have also seen the increased use of "cookies." Cookies comprise data and programs that keep track of a user's patterns and preferences that can be downloaded from the Internet server for storage on the user's computer. Typically, cookies contain a range of addresses. When the browser encounters those addresses again, the cookies associated with the addresses are provided to the Internet server. For example, if a user's password were stored as a cookie, the use of the cookie would allow the user to request services or goods without requiring that the user enter the password again when accessing that service for the second and subsequent time.
However beneficial, cookies can also have their dark side. Many users object to storage of cookies on their computer's hard drive. In response to these concerns, Internet browser software allows the user to select an option so that they are notified before cookies are stored or used. The trouble with this solution is that this usually results in an excessive number of messages prompting the user to accept cookies. A better solution than this all-or-nothing approach would be to allow the storage and/or use of cookies, but to isolate and control that storage and use to comply with user-specified criteria.
Tokens having a Universal Serial Bus (USB) interface can help solve the foregoing problems, but one difficulty in such tokens is that system drivers, application program interfaces (APIs) and other software elements must typically be installed in the host computer terminal before the token can interface with the computer terminal. This can severely limit the token's usefulness by substantially reducing the number of computers that the token can interface with.
One method of solving this problem is to make the installation software available on the Internet where it can be downloaded and installed on remote computers. This, however, requires that the computer terminal have access to the Internet. Further, since the installation programs can be large, a cable or digital subscriber line (DSL) link is required, or the downloading of the program can take an excessive length of time. Another method of solving this problem is to simply carry the installation software in the form provided (typically a CD-ROM) and load it on the computer terminal before using the token. The problem with this is that CD-ROMs are not convenient to carry. This can substantially limit the token's usefulness. What is needed is a system that allows token installation software to be quickly and easily loaded on remote computer terminals so that the token can be utilized.

Token for storing installation software and drivers


An image delivery device is, for example, implemented which is capable of better preventing delays even when real-timeness is required. The image delivery device includes operation information acquisition means, image information acquisition means, allocation information generation means, compression means, and transmission means. The operation information acquisition means acquires operation information. The image information acquisition means acquires image information generated on the basis of the operation information. The allocation information generation means generates allocation information representing allocation of numbers of bits during compression of the image information on the basis of the operation information. The compression means compresses the image information on the basis of the allocation information. The transmission means transmits the compressed image information.

Streamed cloud games are known. In the technology, a game program is executed on the cloud side, and image information generated as a result of execution of the game program is compressed and delivered to terminals by streaming.
Here, among known image information compression techniques are scalable video coding and HEVC. The former permits reduction of transfer size. However, this technique incurs a large delay during encoding and decoding, making this technique unfit for games that require real-timeness. The latter prepares streams with a plurality of resolutions in advance and switches between the streams before delivery, making it difficult to apply the technique to games that require real-timeness.

Image delivery device, image delivery program, and image delivery method


A mower can include a control system that is configured to detect when the mower is turning or will be turned and can adaptively support one or more mower decks during the turn to transfer weight from the mower decks to the mower's tires. This transfer of weight will increase the traction of the mower's tires while also minimizing the yawing force caused by the mower decks thereby preventing the mower from slipping during the turn.

Golf courses, sod farms, and other establishments with expansive grassy areas typically employ large commercial mowers to cut grass. A typical commercial mower may include multiple "mower decks" that house the cutting blades. Unlike a common residential mower, the mower deck of commercial mowers typically houses multiple (e.g., 2-4) cutting blades. These large commercial mowers oftentimes include multiple mower decks that are arranged in a side-by-side fashion to allow the mower to cut a large width of grass with each pass.


A process is disclosed for producing a buried stripe semiconductor laser using dry etching. According to the present invention, a heterostructure is formed by a first epitaxy, during which, on a substrate is deposited a confinement layer having a first doping type, an active layer and a protection layer. The protection layer and the active layer are etched by a reactive ion beam etching method using a gaseous mixture of argon, methane and hydrogen and this takes place down to the confinement layer, so as to form a stripe from the active layer. The stripe is buried by a second epitaxy in a semiconductor layer having a second type of doping which is the opposite of the first. Particular utility is found in the area of optical telecommunications, although other utilities are contemplated.

1. Field of the Invention
The present invention relates to a process for producing a buried stripe semiconductor laser, in which:
a heterostructure is formed by a first epitaxy during which successive deposition takes place on a substrate of a first confinement layer having a first doping type, an active layer and a protection layer,
the protection layer and the active layer are etched up to the first confinement layer, so as to form a stripe from the active layer and
the stripe is buried by a second epitaxy known as "repeat epitaxy" in a semiconductor layer having a second doping type opposite to the first and forming a second confinement layer.
The present invention also relates to a laser obtained by the process according to the invention.
The invention more particularly applies to the field of optical telecommunications and in particular to the production of double heterostructure semiconductor lasers for links by monomodal optical fibres.
2. Brief Description of Prior Art
Various buried stripe laser structures are already known and reference is e.g. made to:
embedded buried heterostructure (EMBH) with blocking junctions,
the flat surface buried heterostructure (FBH),
the semi-insulating planar buried heterostructure (SI-PBH) with semi-insulating layers and
the buried ridge stripe (BRS) structure with homojunctions or heterojunctions.
The growth processes and the static and dynamic characteristics of said laser structures vary very significantly.
However, the BRS structure would appear to be very promising to the extent that it only requires two successive epitaxy cycles and is suitable for all epitaxy methods such as metalorganic chemical vapour deposition (MOCVD) and molecular beam epitaxy (MBE).
Various known BRS structures are described in documents (1) to (4), which are given at the end of the description and to which reference should be made.
It is also known that Thomson CSF and C.N.E.T. (Centre National d'Etudes des Telecommunications) are at present studying BRS structure lasers emitting at 1.3 and 1.5 micrometer. An example of such BRS structure lasers is diagrammatically shown in FIG. 1.
The known structure shown in FIG. 1 is obtained with the aid of two epitaxy cycles.
In a first epitaxy cycle on a n.sup.+ doped InP substrate 2 is formed a first n doped InP confinement layer 4 and then an undoped InGaAsP active layer 6, followed by a p doped InP protection layer having a limited thickness. This is followed by the etching of a stripe over a width of e.g. 2 micrometers up to the first confinement layer 4 and using a bromine-based chemical solution.
A second epitaxy cycle makes it possible to grow again on the stripe a second p doped InP confinement layer 8, followed by a p.sup.+ doped InGaAs contact layer 10.
The localization of the electric current on the mesa resulting from the etching is then obtained by the implantation of protons in the contact layer 10 and in the second confinement layer 8, which produces high resistivity regions 12 and 14 on either side of the active stripe formed. Finally, on the contact layer 10 is deposited a platinum layer 16 and then a gold layer 18.
The production process of the BRS structure described with reference to FIG. 1, although interesting in certain respects (particularly for the ease with which it can be carried out and its compatibility with all growth processes, particularly in the vapour phase) still suffers from disadvantages.
Thus, as the etching of the stripe takes place chemically in solution, problems inherent in this procedure arise during the production of the structure, particularly on large surface epitaxied semiconductor plates.
A first problem is the lateral etching of the stripe or underetching, which is characteristic of all isotropic etching operations. In view of the limited width of the mask used for the etching (2 micrometer), this phenomenon leads to a limitation of the etching depth in the material to a few hundred nanometers so as not to excessively reduce the final width of the stripe (which is typically 1.4 micrometer).
A second problem is the lack of uniformity of the etching, particularly over large surfaces where, as has been experimentally shown, chemical etching in solution initially starts on the edges of the submerged sample and spreads towards the centre thereof, thus bringing about a significant stripe depth and width variation between the sample edge and centre.
A third problem results from the fact that chemical etching in solution is known to be highly dependent on several external parameters (particularly the temperature, agitation and brightness), so that the structure obtained is difficult to reproduce.
The present invention aims at obviating the above disadvantages.

Process for producing a buried stripe semiconductor laser using dry etching for forming said stripe and laser obtained by this process

France Telecom Etablissment Autonome de Droit Public


A nonvolatile logic gate device is configured to include a resistive network of a memory structure in which at least three nonvolatile resistive elements are connected, a reference resistive network as a reference resistance providing a tolerance of the memory structure to a resistance value of the resistive network of the memory structure, a writing part operable to selectively write or rewrite a value of each of the nonvolatile resistive elements in the resistive network into a maximum or a minimum corresponding to a logical value to be read when data are stored into the resistive network, and a logic circuit structure operable to use, as a logical value of the memory structure, a value obtained by comparison between the resistance value of the resistive network and the resistance value of the reference resistive network.

In recent years, an increase of electric power consumption caused by leakage currents of transistors has been problematic as a degree of integration of semiconductors increases. An arrangement in which a memory element and a logic element have been separated from each other results in data transfer delay and increased electric power consumption of wires for data transfer, both of which have also been problematic.
As one of methods for solving those problems, Patent Literature 1 has proposed an integrated circuit using a nonvolatile logic gate in which a memory element and a logic element have been integrated with each other. This integrated circuit is characterized in that data are not eliminated even if a power source is turned off because data are stored by a plurality of nonvolatile resistive elements. Therefore, the integrated circuit can dispense with a power source for holding data during an inoperative period. Accordingly, electric power consumption by a leakage current during an inoperative period can be reduced. Additionally, since the memory element and the logic element are arranged close to each other, the integrated circuit is expected to be operated with less wiring delay and less electric power consumption.
FIG. 1 shows an example of an arrangement of a nonvolatile logic gate that can be used for the aforementioned integrated circuit. The illustrated nonvolatile logic gate includes an NMOS logic circuit, nonvolatile resistive elements R1 and R2 and a through current control circuit for storing complementary data as resistance values, a sense circuit, and a writing part used for writing or rewriting data of the nonvolatile resistive elements. Furthermore, the sense circuit includes PMOS transistors P1 and P2 for latching output data and two PMOS transistors P3 and P4 for precharge. The sense circuit is connected to the NMOS logic circuit. Each of the illustrated nonvolatile resistive elements R1 and R2 has a first end connected to the NMOS logic circuit and a second end connected to the through current control circuit.
Next, specific connections of the components of the nonvolatile logic gate shown in FIG. 1 will be described. A gate of the PMOS transistor P1 is connected to a drain of the PMOS transistor P2, a drain of the PMOS transistor P4, and the NMOS logic circuit, and is also connected to a data output terminal for outputting an output signal /Dout. Meanwhile, a gate of the PMOS transistor P2 is connected to a drain of the PMOS transistor P1, a drain of the PMOS transistor P3, and the NMOS logic circuit, and is also connected to a data output terminal for outputting an output signal Dout. Gates of the PMOS transistors P3 and P4 are supplied with a clock signal CLK. Each of sources of the PMOS transistors P1, P2, P3, and P4 is connected to a power source voltage Vdd.
For example, a magnetic tunnel junction (MTJ) element using magnetoresistance effects may be used for the nonvolatile resistive elements R1 and R2 shown in FIG. 1. Here, an MTJ element has a ferromagnetic layer (free layer) variable in a direction of magnetization, a ferromagnetic layer (fixed layer) fixed in a direction of magnetization, and an insulator layer formed between the free layer and the fixed layer. When a current is supplied in a direction perpendicular to the film surface of such an MTJ element, the resistance value of the MTJ element varies depending upon the magnetization directions of the free layer and the fixed layer. The resistance value of the MTJ element decreases when the magnetization of the free layer and the magnetization of the fixed layer are parallel to each other, whereas the resistance value of the MTJ element increases when the magnetization of the free layer and the magnetization of the fixed layer are opposite to each other.
The MTJ element uses those characteristics to store data corresponding to the magnitude of the resistance value, i.e., the direction of the free layer. For example, a low-resistance state is made to correspond to data "0" while a high-resistance state is made to correspond to data "1". The nonvolatile logic gate uses data of this MTJ element for a logical operation.
Methods of writing data into an MTJ element include a magnetic field writing method of controlling a magnetization direction of a free layer by the use of a current magnetic field and a spin torque writing method of controlling a magnetization direction of a free layer by the use of a spin torque effect.
The nonvolatile logic gate shown in FIG. 1 performs a logical operation by the use of data stored in the nonvolatile resistive elements R1 and R2. Specifically, the nonvolatile logic gate performs a calculation between data stored in the nonvolatile resistive elements R1 and R2 and an input data Din externally inputted into the NMOS logic circuit, and outputs complementary outputs Dout and /Dout. A designer can determine what operation is performed by the nonvolatile logic gate, and can properly design the NMOS logic circuit for that purpose.
Now a configuration of the through current control circuit connected to the nonvolatile resistive elements R1 and R2 will be described with reference to FIGS. 2(a) and 2(b). The through current control circuit shown in FIG. 2(a) has an NMOS transistor N1. A drain of the NMOS transistor N1 is connected to an end of each of the nonvolatile resistive elements R1 and R2. A source of the NMOS transistor N1 is grounded, and a gate of the NMOS transistor N1 is supplied with a clock signal CLK.
Meanwhile, the through current control circuit shown in FIG. 2(b) has two NMOS transistors N1 and N2 and a capacitor C1 having a first end being grounded and a second end connected to a common junction of the NMOS transistors N1 and N2. Furthermore, a drain of the NMOS transistor N1 is connected to an end of each of the nonvolatile resistive elements R1 and R2, and a source of the NMOS transistor N1 is connected to a drain of the NMOS transistor N2 and the end of the capacitor C1. A gate of the NMOS transistor N1 is supplied with a clock signal CLK. A source of the NMOS transistor N2 is grounded, and a gate of the NMOS transistor N2 is supplied with an inversed clock signal /CLK.
The through current control circuits shown in FIGS. 2(a) and 2(b) differ from each other in existence or in non-existence of a through current flowing during a logical operation. In the case of the through current control circuit shown in FIG. 2(a), a current steadily flows through the nonvolatile resistive elements R1 and R2 and the NMOS transistor N1 when the clock signal CLK is at a high level. On the other hand, in the case of the through current control circuit shown in FIG. 2(b), a current flows through the nonvolatile resistive elements R1 and R2 and the NMOS transistor N1 only during the charging of the capacitor C1 when the clock signal CLK is at a high level. Therefore, less steady current flows in the circuit shown in FIG. 2(b) than in the circuit shown in FIG. 2(a). Accordingly, the through current control circuit shown in FIG. 2(b) can reduce electric power consumption during an operation.
FIG. 2(c) shows an example of an NMOS logic circuit forming a nonvolatile logic gate. This exemplary circuit illustrates an NMOS logic circuit (SUM circuit) for performing an addition or a sum operation. The illustrated NMOS logic circuit has eight NMOS transistors N3, N4, N5, N6, N7, N8, N9, and N10. Complementary input signals A and /A and C and /C are inputted as data input signals Din into gates of the NMOS transistors N3 to N10. A current path is formed in each of the NMOS logic circuits depending upon the corresponding input signal. An end of the nonvolatile resistive element R1 in the illustrated circuit configuration is electrically connected to the NMOS logic circuit on a side of outputting a data output Dout. An end of the nonvolatile resistive element R2 is electrically connected to the NMOS logic circuit on a side of outputting a data output /Dout. A difference of current values flowing through those two current paths is used to determine output voltages as data outputs Dout and /Dout, i.e., logical operation results (output results).
A nonvolatile logic gate formed by a combination of the components illustrated in FIGS. 1, 2(b), and 2(c) operates in the following manner. The illustrated nonvolatile logic gate has a precharge period and an evaluation period. Such an operation of the nonvolatile logic gate is a particular operation that differs from an operation of a general static CMOS circuit.
First, there is defined a precharge period during which a clock signal CLK is at a low level. During the precharge period, the NMOS transistor N1 of the through current control circuit (FIG. 2(b)) is turned off, and the PMOS transistors P3 and P4 of the sense circuit (FIG. 1) precharge the outputs Dout and /Dout into a power source voltage Vdd. Furthermore, at that timing, the NMOS transistor N2 (FIG. 2(b)) of the through current control circuit discharges charges accumulated in the capacitor C1.
Meanwhile, there is defined an evaluation period during which the clock signal CLK is at a high level. During the evaluation period, the NMOS transistor N1 of the through current control circuit (FIG. 2(b)) is turned on, the NMOS transistor N2 is turned off, and the precharge PMOS transistors P3 and P4 of the sense circuit (FIG. 1) is turned off.
The charges accumulated in capacitors (not shown) during the precharge flow into the capacitor C1 of the through current control circuit via the two current paths formed within the NMOS logic circuit and the nonvolatile resistive elements R1 and R2, which have stored the complementary resistance values. The currents flow through the nonvolatile resistive elements R1 and R2 depend upon the resistance values of the nonvolatile resistive elements R1 and R2. Therefore, a potential difference is produced between Dout and /Dout, which are complementary outputs. The potential difference is amplified by the PMOS transistors P1 and P2, and then complementary data output Dout and /Dout are outputted. It should be noted that, in this nonvolatile logic gate, the input signals A, /A, C, and /C should be unchanged during the evaluation period, during which the clock signal CLK is at a high level. In this manner, the nonvolatile logic gate has an operation function and a latch function.


The exhaust of a vehicle paint spray booth is fed through an adsorption medium, such as activated carbon, to remove volatile organic compounds by adsorption. When the adsorbent becomes saturated, it is purged by electric heaters, and the desorbed volatile organic compounds are directed to the fuel processor of a stationary fuel cell. The volatile organic compounds are broken down into oxides of carbon and hydrogen gas in the fuel processor, the hydrogen is fed to the fuel cell, and the oxides of carbon are vented to the atmosphere with excess air. The fuel cell combines the hydrogen with oxygen from air, and releases air, water vapor and electrical power.

A vehicle paint spray booth exhausts air laden with volatile organic compounds. These compounds must be removed from the exhaust air stream to comply with applicable environment regulations. Existing abatement systems typically burn the exhaust to break down the volatile organic compounds into, among other products, oxides of nitrogen, which must-then themselves be abated. In addition, there is a substantial cost associated with energy consumption. It is an object of the present invention to provide a system and method for abating or removing volatile organic compounds from an air stream, such as the exhaust from a vehicle paint spray booth, that require reduced energy consumption, and that produce hydrogen as a product that can be fed to a fuel cell to produce electrical power. Another object of the invention is to provide an electrical power system and method that include a stationary fuel cell which delivers power derived from volatile organic compounds removed from an air stream.
A system for removing volatile organic compounds from an air stream in accordance with a presently preferred embodiment of the invention includes an adsorption system operable in a first mode of operation for adsorbing volatile organic compounds from the air stream, and in a second mode of operation for heating the adsorbent to release the volatile organic compounds adsorbed during the first mode of operation. A fuel processor receives the volatile organic compounds released during the second mode of operation to convert the volatile organic compounds into hydrogen and oxides of carbon. In the preferred embodiment of the invention, the hydrogen is fed to a fuel cell for producing electrical power. The adsorption system in accordance with the preferred embodiment of the invention includes a plurality of adsorbents and associated heaters disposed in associated chambers, and valves for routing the incoming air stream through at least one of the chambers while at the same time operating the heaters associated with at least one of the other chambers to release the volatile organic compounds previously adsorbed. In this way, the system is continuously operable to produce hydrogen fed to the fuel cell.

Volatile organic compound abatement through a fuel cell