A method of making thin film transistors, capable of reducing the extent of channel overlap between a gate electrode and source/drain regions, thereby achieving an improvement in signal-to-noise ratio. The method uses a impurity ion doping process and a process for forming a silicide layer using a refractory metal, so as to form source and drain electrodes in a self-aligned manner, with respect to the gate electrode. In order to avoid a channel overlap from occurring between the gate electrode and the source and drain electrodes, a photoresist pattern is subjected to a baking, which photoresist pattern defines an insulating layer pattern serving as a channel passivation layer to determine the of a channel region and the widths of source and drain regions. By the baking, the photoresist pattern flows outwardly so that its width is approximately equal to the length of the gate electrode.

1. Field of the Invention
The present invention relates to a method of making thin film transistors, and more particularly to a method of making thin film transistors suitable in forming a high quality of thin film transistors-liquid crystal displays in a large area.
2. Description of the Prior Art
Currently, a thin film transistor-liquid crystal display (TFT-LCD) is known as one of the promising flat displays required for obtaining a larger displaying area, a higher pixel density and a better video quality. FIG. 1 shows an equivalent circuit for one pixel in such a TFT-LCD.
Supplying of voltage to each pixel electrode is carried out via a signal line by a corresponding thin film transistor which is switched by a gate voltage supplied via a gate bus line. Generally, a parasitic capacitance (Cgd) is inevitably present between a gate and a drain of the transistor. Accompanying a variation of the gate voltage Vg from a voltage level at ON-state to a voltage level at OFF-state, the parasitic capacitance Cgd causes a feed-through of the pixel electrode voltage, as shown in FIG. 1.
This feed-through voltage V can be expressed by the following formula 1: ##EQU1## where, Cic and Cst are other parasitic capacitances.
The feed-through voltage V acts to break the balance of the voltage applied to the liquid crystal, resulting in flickering of the LCD and a decrease in the reliability. For removing the feed-through voltage, the Cst should be sufficiently large, as compared with the Cgd. When the TFT-LCD has a larger size and a higher pixel density, the Cic increases and the charging time decreases. Accordingly, charging for the enlarged Cic should be in a shortened charging time. Also, the value of W/L (where, W is the channel width of TFT and L is the channel length of TFT) should be increased, which determines the value of ON current for TFT, where L is constant, W and Cgd increase. For effectively removing the feed-through voltage V, the Cst should be increased more. However, the resistance for a SC line can not be decreased to a small value. This is because of a limitation on pixel aperture rate. As a result, it is difficult to control the SC electrode voltage at a larger size of the display. To decrease the Cgd is the most efficient method for solving this problem. The generation of the Cgd results from an overlap between the gate electrode and the source/drain electrodes. However, this overlap is necessarily present in case of an inverted staggered type TFT and can not be reduced below 2 .mu.m due to an accuracy in mask alignment required for a large size of the display.
Referring to FIG. 2, there is illustrated a general inverted staggered type TFT which is characterized by an insulation layer and a semiconductor layer formed on a gate electrode. In such a construction, the overlap can be extremely reduced by self-aligning the source/drain electrodes with the gate electrode. However, known methods use a conventional lift-off process which has no utility for a TFT array.
For solving this problem, a new type of self-aligned TFT has been proposed by S. Nishida et al., Japan NEC corporation. Such a self-aligned TFT is manufactured by using a back substrate exposure process as well as an ion doping process and a chromium silicide formation technique. The self-aligned TFT has a sufficient utility for the manufacture of TFT-LCDs.
Now, a method of making the self-aligned TFT proposed by S. Nishida et al. will be described in conjunction with FIGS. 3a to 3e.
As shown in FIG. 3a, first, on an insulating transparent substrate 1 is formed a gate electrode 2. Over the entire exposed surface of the transparent substrate 1 and gate electrode 2 are deposited a first insulation layer 3, an amorphous silicon layer 4 as a semiconductor layer, and a second insulation layer 5, in this order. A photoresist 6 is subsequently coated over the second insulation layer 5. Thereafter, the photoresist 6 is subjected to a back substrate exposure which is carried out at the back side of the transparent substrate 1, so as to form a photoresist pattern 6a, as shown in FIG. 3b.
The second insulation layer 5 is subsequently subjected to a dry etch using the photoresist pattern 6a as a mask so that it is removed except for its portion disposed beneath the photoresist pattern 6a, so as to form a second insulation layer pattern 5a, as shown in FIG. 3c. Thereafter, the photoresist pattern 6a is removed.
Using the second insulation layer pattern 5a as a mask, high concentration N type (N.sup.+ type) impurity ions such as phosphorous are implanted to a predetermined depth in the amorphous silicon layer 4, with an energy of 30 Kev. Accordingly, the portions of amorphous silicon layer 4 implanted with N.sup.+ type impurity ions form N.sup.+ type conductive layers 7 and 7a which are disposed at opposite sides of the second insulation layer pattern 5a, respectively. At this time, the portion of amorphous silicon layer 4 disposed beneath the second insulation layer pattern 5a is not implanted with the N.sup.+ type impurity ions such as phosphorous.
Over the resultant entire exposed surface, thereafter, a refractory metal layer 8 having a high meting point is deposited using a sputtering process, to have a thickness of 100 nm, as shown in FIG. 3d. Chromium is generally used as the material of refractory metal layer 8. Upon depositing the refractory metal layer 8, the portions of N.sup.+ type conductive layers 7 and 7a being in contact with the refractory metal layer 8 are modified to form silicide layers 9 and 9a having a thickness of not more than about 5 nm. The silicide layers 9 and 9a have an etch selectivity different from that of the refractory metal layer 8. Upon the subsequent removal of the refractory metal layer 8, accordingly, it is possible to prevent the silicide layers 9 and 9a from being etched together with the refractory metal layer 8, resulting in achieving a stabilized processing.
The second insulation layer pattern 5a is used as a channel passivation layer, whereas the portion of amorphous silicon layer 4 disposed beneath the second insulation layer pattern 5a is used as a channel layer. On the other hand, the N.sup.+ type conductive layers 7 and 7a formed at opposite sides of the second insulation pattern 5a are used as source and drain regions, respectively. The silicide layers 9 and 9a formed on the N.sup.+ type conductive layers 7 and 7a are used as source and drain electrodes, respectively.
Thereafter, the refractory metal layer 8 is subjected to a patterning using an etchant, so as to leave refractory metal layer portions 10 and 10a at opposite side ends of silicide layers 9 and 9a disposed at opposite sides of the second insulation pattern 5a, respectively, as shown in FIG. 3e.
As apparent from the above description, the technique by S. Nishida et al. makes it possible for source and drain regions to be formed above the gate electrode 2 in a self-aligned manner, according to the back substrate exposure process.
As a result, a channel overlap portion between the gate electrode and the source/drain regions is reduced so that the generation of parasitic capacitance between the gate electrode and the source/drain regions is considerably reduced, as compared with the technique using the lift-off process. Furthermore, it is possible to improve the signal-to-noise ratio, in that the parasitic capacitance acts as noise. According to the technique by S. Nishida et al., the channel overlap can be reduced to 1 .mu.m.
For obtaining a high quality of TFT-LCDS, it is most important that the channel overlap portion formed between the gate electrode and the source/drain regions is as small as possible. However, the technique by S. Nishida et al. encounters several problems as will be described hereinafter.
As shown in FIG. 3b, the photoresist pattern 6a which is formed by the back substrate exposure carried out at the back side of the transparent substrate 1 should have a width approximately equal to the length of the gate electrode 2. This width of photoresist pattern 6a makes it possible to reduce the channel overlap as much as possible. However, the actual width of photoresist pattern 6a is basically narrower than the length of gate electrode 2, as shown in FIG. 3b, due to a diffraction of the light which is used in the exposure process. As a result, channel overlap occurs at portions of the gate electrode 2 extending inwardly from its opposite side edges, respectively. Of course, the reduced width may vary slightly depending on the exposure time and the developing time.
In particular, the diffraction angle of the light (for example, g-line) used for the exposure is varied depending on thicknesses of the amorphous silicon layer 4, the first insulation layer 3 and the second insulation layer 5 formed on the transparent substrate 1. As a result, the widths of the photoresist pattern 6a and the second insulation layer pattern 5a are also varied. Due to these factors, the technique by S. Nishida et al. has a limitation on the reduction of channel overlap. Moreover, since the second insulation pattern 5a determines the extent of channel overlap as well as the widths of source and drain regions, frequent variation in the width of the second insulation layer pattern 5a causes the mass production of TFTs to be wanting in consistency, thereby resulting in several difficulties.
As apparent from the above description, there is a limitation on the reduction of channel overlap, in case of using only the self-alignment technique as proposed by S. Nishida et al.. Consequently, it is impossible to improve the characteristic of TFT.


Systems and methods for performing neighbor discovery in a network (100) including a number of nodes are provided. A first node (110) in the network (100) generates a spread signal for alerting other nodes in the network (100) of the presence of the first node (110). The first node (110) broadcasts the signal and a second node (120) receives the signal and calculates an energy associated with the received signal. The second node (120) also determines whether the energy is greater than a threshold and identifies the first node (110) as a neighbor node when the energy is greater than the threshold.

1. Field of the Invention
The present invention relates generally to networks and, more particularly, to systems and methods for detecting the presence of nodes in wireless networks.
2. Description of Related Art
The use of ad hoc wireless networks has increased in recent years. An ad hoc wireless network typically includes several wireless, sometimes mobile, nodes. In such a network, all of the nodes may be equipped with wireless communications transceivers. Some of the nodes (e.g., routers) may be designed to perform network routing functions while other nodes may be merely sources or destinations for data traffic.
All of the nodes in the network may execute a set of algorithms and perform a set of networking protocols that enable the nodes to find each other and determine paths through the network for data traffic from source to destination(s). The algorithms/protocols also enable the nodes to detect and repair ruptures in the network as nodes move, as nodes fail, as battery power changes, as communications path characteristics change over time, and so forth.
Conventional ad hoc wireless networks employ "beacons" as a way in which network nodes can perform neighbor discovery (i.e., locate other nearby nodes). A beacon is a transmission that can be generated by one node and received by some or all of the nodes within a transmission range. In other words, the beacon is a broadcast, rather than a transmission to any particular node. In some networks, all of the nodes may beacon, while in other networks, only a subset of the nodes may beacon. Beacons serve to alert a given receiving node that there may be one or more other (i.e., transmitting) nodes in their proximity.
Beacons typically include an identification of the node that is transmitting the beacon, forward error correction information, and other information based on the type of wireless networking protocols being employed. In conventional practices, the intent of beaconing is to ensure that other network nodes have the highest feasible chance of receiving the beacons, so that the nodes in the ad hoc network can form neighbor relationships and transmit data through the network. As a result, beacons are typically sent at regular intervals at the highest power level possible and include a fairly large number of bits of information content.
This combination of factors, however, makes it extremely easy for an adversary to detect the beacons. The adversary may also perform direction finding on the beacon transmissions to detect the actual physical locations of the wireless network nodes. The adversary may then attempt to physically attack one or more of the nodes in the network based on information gained from detecting the beacons and determining the location of the node(s). In addition, by knowing the network layout, the adversary may be able to eavesdrop on radio transmissions in the network more easily. The adversary may then try to use this information to access confidential information from the network.
Therefore, a need exists for systems and methods that enable nodes to perform neighbor discovery with a low probability of detection.

Systems and methods for beaconing in wireless networks with low probability of detection


A system includes a laser source coupled to an optical waveguide which has a laser output portion, and a vaginal housing transparent to laser energy which is emitted by the laser source and which exits the laser output portion, wherein the optical waveguide is movable along a path inside the vaginal housing.

Vaginal relaxation is the loss of the optimum structural architecture of the vagina. This process is generally associated with natural aging and childbirth, whether vaginal or not. Multiple pregnancies increase the alteration of these structures. During the vaginal relaxation process, the vaginal muscles become relaxed with poor tone, strength, control and support. The internal and external vaginal diameters can greatly increase with significant stretching of vaginal walls.
Recently new modalities for treatment of aged vaginal walls have been introduced, based on skin resurfacing and skin tightening methods, both ablative and non-ablative. The goal of vaginal rejuvenation is to induce tightening and promote new collagen regeneration.
In ablative procedures, the upper layer of the skin is either fully removed (bulk removal) or partially removed (fractional treatment).
Lasers commonly used for ablative removal are CO2 laser (wavelength of 10.6 μm) or Er:YAG laser (erbium-doped yttrium aluminum garnet) (wavelength of 2.94 μm), both of which have strong water absorption. Other lasers have been proposed, such as Tm:YAG (wavelength of 2.0 μm), Ho:YAG (wavelength of 2.1 μm), and Er,Cr:YSGG (erbium, chromium-doped yttrium scandium gallium garnet) (wavelength of 2.78 or 2.79 μm).
Different methods have been proposed for non-ablative procedures. For example, ablative lasers (like CO2 or Er:YAG) are used in a long pulse mode below the ablation threshold, so as to cause thermal effects due to conduction of the heat to the tissue but without ablation of the tissue. Other lasers have been used with a non-ablative wavelength with low water or blood absorption so that the effect is purely thermal and non-ablative.
Laser energy is applied to the vaginal walls through an opening in a tube which is inserted in the vagina. The tube is rotated so that the laser energy exits the opening at intervals of 90° or other angular interval; the tube is then moved proximally back (about 1 cm) and the procedure is repeated until the length of the vagina is covered. The procedure can be done multiple times in the same session.
In all laser technologies, in order to be effective, the laser beam must be focused on the vagina wall. However, focusing is often impossible since the vaginal wall is not straight or smooth; rather it contains many wrinkles.
Other methods include heating by means of ultrasonic energy or RF energy (bipolar or monopolar) at different RF frequencies, between 0.5-40 MHz. However, in RF treatment, the RF electrodes must be in tight contact with the vagina wall so that RF impedance closely matches the tissue so that the RF energy is not reflected back. This is difficult to achieve and may cause discomfort to the patient. The procedure time is disadvantageously long in order to be effective.

Vaginal tightening and treatment of wrinkles


A transistor device including a semiconductor material layer, a gate layer, and an insulation layer between the gate layer and the semiconductor material layer is provided. The semiconductor material layer includes a first conductive portion, a second conductive portion, a channel portion between the first conductive portion and the second conductive portion, and a first protruding portion formed integrally. The channel portion has a first boundary adjacent to the first conductive portion, a second boundary adjacent to the second conductive portion, a third boundary, and a fourth boundary. The third boundary and the fourth boundary connect the terminals of the first boundary and the second boundary. The first protruding portion is protruded outwardly from the third boundary of the channel portion. The first gate boundary and the second gate boundary are overlapped with the first boundary and the second boundary of the channel portion.

With the development of the manufacturing techniques of electronic elements, the research and development of flexible electronic products are becoming more and more vigorous. The main issue that flexible electronic products such as flexible display panels need to overcome is that the electronic products are constantly bent during use such that elements in the electronic products may be readily damaged due to stress. In particular, electronic elements require a semiconductor material to achieve the performance of the product. The conductive properties (or semiconductor properties) of many semiconductor materials may be changed after stress is applied, such that the operating stability of the electronic elements readily becomes poor. For instance, by using a semiconductor material as the channel layer of the transistor element, the phenomenon of conduction voltage (or threshold voltage) offset or the phenomenon of leakage current may occur due to stress.

Transistor device having protruding portion from channel portion

Industrial Technology Research Institute


A system includes a solids pressurizing feeder and an outlet pipe coupled to an outlet channel of the solids pressurizing feeder. The outlet pipe includes a plurality of pipe segments telescopically coupled to one another such that a length of the outlet pipe is adjustable. The solids pressurizing feeder may be used to convey a mixture of solids and fluids.

The subject matter disclosed herein relates to conveying solids through an outlet pipe, and, more particularly, to conveying solids through an outlet pipe of a pump.
Various industrial processes include the conveying of solids in the presence of fluids, which may be gases or liquids. For example, a coal and biomass mixture may be conveyed through a solids pressurizing feeder in an integrated gasification combined cycle (IGCC) power plant. In systems such as these, the amount of force to convey the solids mixture through the system varies depending on the chemical compositions, moisture content, compressibility, and other variables of the solids mixture. Thus, system components that contribute to the overall force needed by the system to drive the solids mixture might often need to be changed or replaced when a different amount of overall force is needed by the system. Replacing these system components may be difficult, and it may be inefficient and costly to frequently replace such system components.

System and method for conveying solids through an outlet pipe


A portable apparatus is capable of switching between a plurality of smart cards and associated circuits to provide a user various independent electronic wallet functions via a single portable apparatus, thereby increasing utilization flexibility and convenience. The portable apparatus includes at least a first smart card and a second smart cart, a near-field communication (NFC) unit, and a control circuit. The first smart card and the second smart card respectively include a first interface and a second interface. The NFC unit is coupled to the first smart card and the second smart card via the first interface and the second interface, respectively. The NFC unit is capable of performing NFC with external apparatuses. The control circuit controls the NFC unit to communicate with either the first smart card or the second smart card using control signals.

In recent years, various electronic payment and electronic transaction functions using a mobile phone with an electronic wallet function has become more and more popular. A common application is where the mobile phone serves as a contactless smart card from which value of an electronic wallet is added or deducted provided that the mobile phone is placed within a radio sensing range of a reader supporting the electronic wallet function, e.g., the radio sensing range is within a radius of around 10 centimeters. FIG. 1 is a block diagram of a mobile phone 10 having the foregoing electronic wallet function in the prior art. The mobile phone 10 communicates with an external near-field communication (NFC) reader 16 via the NFC technique. The mobile phone 10 comprises a subscriber identity module (SIM) card 11, a security chip 12, an NFC chip 13, an antenna 14, and a control circuit 15. When the mobile phone 10 is within a sensing range of the NFC reader 16, the NFC chip 13 writes via the antenna 14 information (e.g., value-added/value-deducted information) from the NFC reader 16 to the security chip 12, or responds data (e.g., available balance) stored in the security chip 12 to the NFC reader 16.
However, following problems may occur when the mobile phone 10 is applied to perform the electronic wallet function. A first problem may occur when a user replaces a mobile phone, the data (e.g., available balance) originally stored in the security chip 12 cannot be accessed and transmitted to a new mobile phone. A second problem may occur, since the NFC chip 13 is only powered by a battery (not shown) of the mobile pone 10, the battery needs to have remaining power when the mobile phone 10 performs electronic payment. Therefore, a situation may occur where after a user enters a railway station, he cannot leave the railway station since the battery becomes empty due to frequent utilization of the mobile phone 10 (e.g., answering a phone call). The foregoing problems may incur significant inconveniences of the user.
To solve the foregoing problems, a Single Wire Protocol (SWP) for accessing an SIM card by a mobile phone via the NFC technique is developed. As shown in FIG. 2, a mobile phone 20 comprises an SIM card 21 conforming to the SWP, an NFC chip 23 conforming to the SWP, an antenna 24, and a control circuit 25. When a battery of the mobile phone 20 becomes empty, the NFC chip 23 can generate power supply by electromagnetic waves transmitted from an NFC reader to maintain operation. Data originally stored in a security chip is stored into the SIM card 21 and is applied to different mobile phones. However, since most electronic wallet function providers, e.g., bank systems, public transport system, and the like, independently operates, the electronic wallet functions cannot be integrated to a single SIM card released by a telecommunication company thereby creating limitations of the service range of an electronic wallet function supported by the SIM card 21.

Portable apparatus for supporting electronic wallet


Power generation stabilization control systems and methods include monitoring a frequency of the power grid. In response to detecting a frequency event occurring in the power grid, the method includes activating a control scheme in order to meet one or more grid requirements of the power grid. The control scheme includes increasing a power output of the wind turbine to, at least, a pre-event measured grid power. Further, the control scheme includes calculating a power correction factor for a power set point as a function of, at least, the frequency event. Moreover, the control scheme includes adjusting the power set point via the power correction factor such that the power output follows a predetermined trajectory. In addition, the control scheme includes controlling, via a turbine controller, the wind turbine based on the adjusted power set point for as long as the control scheme is activated.

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor including one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
Wind turbine generators and wind farms are typically designed to deliver constant active and reactive power to the utility grid with the delivered power being independent of system frequency. This is accomplished by decoupling the rotor inertia and speed from the grid using fast acting power electronics and controls. Due to increases in wind-farm size and penetration, some utilities are now requiring that wind-farm and wind-turbine controls provide enhanced capabilities such as frequency stabilization.
Conventional synchronous generators naturally respond to frequency disturbances due to the grid coupled rotating inertia and governor controls of such generators. Some utility operators require that wind turbines respond in a similar way to frequency disturbances. Specifically, a short duration power increase (for example, five or ten percent of rated power) may be needed when frequency dips below a certain threshold.
It is a well-known characteristic of utility systems that the grid frequency tends to decrease when the load exceeds the generation and to increase when the generation exceeds the load. Such decreases or increases may occur in a monotonic manner, an oscillating manner, or combinations thereof when the grid is subjected to a sudden change in the balance between generation and load. It is a consideration in the design of such a system that any method to achieve compensation of such decreases or increases should be one that does not cause unacceptable coupling between grid oscillatory modes and the wind turbine mechanical oscillatory modes.
Modern wind farms include the capability to curtail output power below the level available based on wind conditions. Utility grid operators sometimes require curtailment if the available grid power is not needed by the utility. Continuous curtailment may also be required by utility operators to provide an operating range for the wind farm to increase power output when frequency decreases.
Thus, as grid requirements continue to change, wind turbine power systems are continuously in need of being able to meet such requirements. Accordingly, the present disclosure is directed to systems and methods for controlling a wind turbine connected to a power grid that activates a predefined control scheme in response to a frequency drop in the power grid in order to the grid requirements thereof.


A system, article, and method of feature matching for multiple images.

Camera arrays, which may be provided on tablets or smartphones for example, may be provided to capture multiple images of the same scene except from different angles. These images can then be used to generate a 3D space or depth map, and accurately locate objects from the scene and into the 3D space. This is performed so that objects in the scene, or distances between objects in the scene (or from the camera to the object) can be measured, for computer vision, artificial intelligence, object recognition, and otherwise whenever it is desirable to know the size, position, or identity of an object.
Feature matching (or feature point matching) is used to match the features of an object (such as a corner or an edge of an object) from one image to another image captured by a camera array. Feature point matching is widely used in camera calibration to set the proper position or orientation for each camera in the array or on the device with the array, and thereafter, to set an accurate final point location on an object by using the same corresponding feature point from multiple images. Basically, for a feature point from a reference camera image, a matching algorithm finds the corresponding feature point in the other camera images regardless of changes in light, scale, and other transformations. Many of the conventional methods for matching feature points are often too slow or inaccurate especially for mobile devices.

Method and system of feature matching for multiple images


The disclosed embodiments relate to a communication device for use in a node of a system having a plurality of nodes. Each of the plurality of nodes may include network interface controllers (“NICs”) and each of the NICs may have an atomic operation logic device therewith. The atomic operation logic may receive from a requester a packet that contains a request to perform an atomic operation. Then the atomic operation logic may determine that the atomic operation is being requested from the information within the packet. The atomic operation logic may also respond to the requester to indicate whether the atomic operation has been performed.

This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In the field of computer systems, it may be desirable for information to be transferred from a system memory associated with one computer system to a system memory associated with another computer system. The information may be transferred more efficiently by using methods such as remote direct memory access ("RDMA") or direct data placement ("DDP"). In systems that employ RDMA or DDP, it may be desirable to perform atomic operations to conserve system resources and ensure that data integrity is maintained.
If a system central processing unit ("CPU") is used to perform atomic operations, resources of that CPU are consumed and the CPU is able to do less overall work. As a result, the system may perform at degraded levels.

Hewlett-Packard Development Company, L.P.


A method of operating a sound generation mechanism includes determining a temperature of the sound generation mechanism, identifying a resonant frequency of the sound generation mechanism associated with the determined temperature, and communicating an excitation frequency to the sound generation mechanism. The excitation frequency is selected in response to the resonant frequency associated with the determined temperature. The sound generation mechanism is operated to produce one or more sounds.

Embodiments of the disclosure relate to a notification devices and, more particularly, to a method for optimizing the sound pressure level of a piezoelectric horn of a notification device by adjusting its drive frequency in response to changes in temperature.
Typical building fire alarm systems include a number of fire detectors positioned throughout a building. Signals from those detectors are monitored by a system controller, which, upon sensing an alarm condition, initiates operation of one or more notification devices to provide an audio or visual alarm indication to persons within the building. Speakers or horns used in notification devices are typically required to be relatively compact, but capable of producing sound with a suitable intensity within the hearing range of the human ear. The sound output level and current draw are key performance metrics for such a sound generation device.
A piezo sounder is a high intensity sound source usable in a notification device. The piezo sounder is both cost effective and power efficient. However, piezo sounders may experience an adverse loss in sound level as the temperature of the notification appliance departs from a nominal temperature of about 25° C. More specifically, the resonance and drive frequencies associated with operation of a piezo sounder are designed to match at the nominal temperature. However, these frequencies tend to drift apart as the temperature deviates, both increases and decreases, relative to the nominal value. The greater the mismatch between the resonance and drive frequencies, the greater the loss in sound pressure level generated by the piezo sounder.

Temperature compensation for piezo sounder


Upon detection of a trapped passenger in an elevator car, a resident monitoring device initiates communication between the car and a telephone in the building and between the car and a remote monitoring center. Upon detection of the first responsive telephonic communication from either the remote monitoring center or the telephone in the building, voice communication is established therebetween. Upon detection of a second responsive telephonic communication from the second location to respond, voice communication is established between the car and the second location as well so that simultaneous communication may be conducted between the car, the remote monitoring center, and the telephone in the building. A building telephone has a keypad which can be used to select another car for voice communication with a trapped passenger by pressing a selected key. A telephone ring voltage source is provided for alerting building personnel of a trapped passenger. A dual-tone, multi-frequency decoder is provided for determining which keypad button is depressed.

There are failure modes of elevator systems that result in passengers of elevators being trapped inside the elevator car. During this trapped passenger state, we have used remote monitoring to provide relief by means of two-way conversation between the elevator passengers and an attendant of the elevator system, e.g., via a dial up modem. A resident building monitor device makes a determination that there is a trapped passenger and dials a preconfigured telephone number to report the condition. A personal computer in a central monitoring center, which answers the call from the resident device, displays the trapped passenger alarm, building name and address plus the master identification and elevator number. The PC then prompts the operator to "pick-up" the handset. Immediately upon picking up the telephone, the operator will be talking to the trapped passenger. There is presently no facility to provide the operator with simultaneous knowledge as to any other cars which have trapped passengers in the same group of (up to eight) elevators in the building. When the operator hangs up the handset from the first voice contact, if there is a second trapped passenger pending, the PC will then display the second trapped passenger alarm and prompt pickup of the handset. This scenario will continue depending on how many trapped passenger conditions exist. All of the alarms and concomitant voice contacts will be accomplished in a single phone call. The resident device is in control of which elevator the operator converses with, based on the order the alarms are received.
In our system, the monitoring center attendant contacts a serviceman and provides assurances to the passenger while waiting for the arrival of the serviceman. This provides more comfort to the passenger than other systems in which communication is merely provided with the building superintendent. However, when the serviceman arrives he is unable to easily inform the passenger or the remote attendant of his arrival. In other systems, such as shown in Japanese Kokai 2-188384, communication is provided between the trapped passenger and either the remote attendant or the local building manager's office.


A method, apparatus and a system for human body tracking processing, where an apparatus for video collection processing in the system has a built-in intelligent chip, and before uploading video data to a cloud server, the intelligent chip performs a pre-processing on the video data, retains a key image frame and performs a human body detection and a tracking processing on the key image frame by using human body detection tracking algorithm to acquire a first human body detection tracking result. Afterwards, the intelligent chip sends the first human body detection tracking result to the cloud server, so that the cloud server performs a human body re-identification algorithm processing and/or three-dimensional reconstruction algorithm processing on the first human body detection tracking result to acquire a second human body detection tracking result.

Human body tracking technology refers to a technology that tracks a human body in videos in real time and acquires a position of the human body at each moment. Human body tracking is a classic research direction in the field of computer vision, and is applied in many scenes such as video surveillance and behave analyzing.
In the current scene of video surveillance, the human body tracking system includes multiple cameras and a cloud server, where the cloud server tracks the target human body in single camera respectively by using methods such as filtering and convolutional neural network; redetect the tracking failure target in the tracking process through human body detection, and corrects the tracking target in each frame image; and re-identifies and verifies the target human bodies in multiple cameras through body identification, thereby implementing human body tracking with multiple cameras.
Most of the human body tracking systems on the current market do not consider positional relationships between these multiple cameras, and it easily generates large errors during content fusion of multiple cameras, causing problems such as target human body identification errors and positioning deviations. At the same time, since ordinary surveillance cameras do not have computing ability, and the video data taken by all these cameras needs to be uploaded into the cloud server for processing, which has higher requirements on network bandwidth, server resources and so on, and is not conducive to rapid expansion, such as increasing the number of the surveillance cameras and supporting larger scenes.

Method, apparatus and system for human body tracking processing

BAIDU ONLINE NETWORK TECHNOLOGY (BEIJING) CO., LTD.


A pharmacy medication verification system is particularly useful for verifying medications to be dispensed to hospital patients while minimizing or eliminating verification by a pharmacist. Typically, a technician or robot picks the medications from storage bins in accordance with a medical prescription or stocking order and uses various sensors to ensure that the correct medication was picked and enters a medication container. The system typically provides correct and incorrect medication indicators as well as correct and incorrect entry indicators. Error reports may be generated when appropriate to communicate any relevant errors to the pharmacist, who can then verify that the correct medications are in the container. In one aspect, the containers are in the form of patient drawers which fit within a cart for delivery to hospital rooms. A containment device may be used to secure the drawer of other container during the verification process.

1. Technical Field
The present disclosure relates generally to a system and method for controlling the dispensing of pharmaceutical and other medically related items. More particularly, the disclosure relates to a system which is particularly useful for verifying the accuracy of medicines and other items which are to be delivered from a hospital pharmacy to patients in the hospital.
2. Background Information
The dispensing of the proper medications to patients within a hospital is a very important aspect of heath care delivery. For several decades, rolling carts have been used to transport medications from a hospital's pharmacy to hospital patients. These carts have multiple drawers each assigned to an individual patient so that a given patient's medications are disposed in a single drawer within one of the carts. As a practical matter, there are two sets of drawers one of which is generally kept at a nurses station in the hospital and the other of which is generally kept within the pharmacy to be refilled in preparation for dispensing the next day's medications. In short, a technician picks or pulls the pertinent medications for given patients in accordance with a patient-specific list of medications and places them in the patient drawers of the pharmacy carts, which are taken to the nurses station where the drawers of the pharmacy cart are exchanged with those of the nurses cart in preparation for subsequent delivery to hospital patients. The carts thus allow for prescriptions to be filled at the centralized location represented by the pharmacy and transported to decentralized locations such as nurses' stations and patient rooms. A pharmacist verifies that the medications within each drawer are the proper medications.
Dispensing cabinets are also commonly used in the medication delivery system, including automated dispensing cabinets (commonly known as ADCs) which are configured to help control the proper dispensing and tracking of medications. Dispensing cabinets are typically positioned at or near a nurses station and may, like the carts noted above, be configured for transport between the centralized pharmacy and decentralized nurses station for stocking and dispensing, respectively. Such dispensing cabinets have various configurations, but typically include a number of drawers each of which are divided into or contain numerous compartments each of which serves to hold a specific medication in bulk. These compartments may or may not be removable from the drawer. Some of these compartments are configured as open top containers while others include lids which may be opened and closed. One example of such a compartment having a lid is disclosed in U.S. Application Publication 2006/0226167 of Broadfield et al., wherein the lidded compartment is commonly referred to as a "cubie". The number of such compartments within a drawer may easily be 20, 30, 40 or more. These compartments are stocked or re-stocked respectively in accordance with an initial stocking order or re-stocking order which is typically created by a pharmacist or a company which manufactures or sells the dispensing cabinet. As with the patient drawers discussed above, a pharmacist will verify that the proper medications are used to fill these compartments during the stocking or re-stocking process. Although this process of verifying that the proper medications reach a patient's drawer or the compartments of a dispensing cabinet is important, it is also very time consuming.
While there have been a variety of improvements in the verification systems for these medications, there is still a need in the art to provide a more reliable verification system.

This patent is subject to a terminal disclaimer.


Techniques for a database management system to estimate a time needed to refresh a materialized view. This is a followed by an approach that uses estimated refresh duration to determine an optimized schedule for refreshing the materialized view. The approach combines the refresh duration estimate with a query rewrite pattern prediction for the materialized view and a quiet period prediction for the materialized view to determine the optimized refresh schedule for the materialized view.

In database management systems, materialized views are a powerful mechanism for optimizing the processing of queries. A query may be defined as a logical expression over database data and the data relationships set forth in the database, and results in the identification of a subset of the database data. For example, the execution of a request for information from a database management system (DBMS) is typically issued by a client computer system as one or more Structured Query Language (SQL) queries or the like for retrieving particular data from database objects at a server computer system. A database object is any defined object in the database that is used to store or reference data. Examples of database objects include tables, indexes, views, and materialized views.
A materialized view is a database object that contains the results of a query. Instantiation of a materialized view is typically accomplished by executing the query against database objects and storing the result set of the query execution in another database object. The database object(s) referred to in the query from which the result set is derived are sometimes referred to as the "base" database object(s) of the materialized view and those database object(s) are sometimes said to be "referenced in" the materialized view by way of the query. The query that is executed against the base data object(s) to instantiate a materialized view is sometimes referred to herein as the "instantiation" query of the materialized view.
Consider, as a simple example, the following SQL query that provides an aggregation of the dollar amount sold every month:
SELECT t.calendar_month_desc,                SUM(s.amount_sold) AS dollars
FROM sales s,                times t
WHERE s.time_id=time_id
GROUP BY t.calendar_month_desc;
If the above query is used to instantiate a materialized view, then the sales, products, and times tables are the "base" database objects of the materialized view and those tables are "referenced in" the materialized view by way of the instantiation query.
When a database system receives a user query that asks for data from one or more base database objects of a materialized view, the database system may determine if the user query can be rewritten to be executed against the materialized view and thereby provide an answer to the user query more quickly. Returning the above example, consider, as a simple example, the following user query that asks for the sum of the amount sold for each calendar month:
SELECT t.calendar_month_desc,                SUM(s.amount_sold)
FROM sales s,                times t
WHERE s.time_id=time_id
GROUP BY t.calendar_month_desc;
Without a materialized view and query rewrite functionality, the database system may need to perform computationally expensive operations in order to answer a user query that the database system would not need to perform if a materialized view and query rewrite functionality were available. In the current example user query, without the previous example materialized view and query rewrite functionality, the database system may need to access the "sales" database object directly and compute the sum of the amount sold to answer the user query. This might involve reading many million records from the "sales" database object which increases the query response time due to computer storage media (e.g., disk) access. The join in the user query also increases the query response time as the join needs to be computed on potentially many million rows.
In contrast, with the previous example materialized view and query rewrite functionality, the database system can rewrite the example user query to the following rewritten query to be executed against the materialized view:
SELECT calendar_month, dollars
FROM cal_month_sales_mv;
Here, "cal_month_sales_mv" is the given name of the previous example materialized view and "calendar month" and "dollars" are the given names of fields of the materialized view. Since the materialized view contains the results of the previous example instantiation query, the materialized view may contain only a few dozen records. Further, the rewritten query does not contain a join. Consequently, the database system can answer the previous example user query essentially instantaneously by executing the rewritten query against the materialized view and returning the result of the rewritten query as an answer to the user query. Clearly, materialized views are a powerful mechanism for optimizing the processing of queries.
A difference between a view and a materialized view is that a materialized view is typically instantiated once for many accesses while a view is typically instantiated for each access. Typically, this means that materialized view requires more computer storage media space to store the materialized view when the materialized view is not being accessed, but at the same time allows rewritten queries against the materialized view to be processed faster because the materialized view does not need to be instantiated for each rewritten query execution.
Since materialized views are not instantiated for each rewritten query execution, a materialized view can become "stale" with respect the base database object(s) referenced in the materialized view. In particular, changes to the base database objects referenced in a materialized view that occur after the materialized view is instantiated can place the materialized view in a stale state because the result set of the materialized view does not reflect the after-instantiation updates to the base database objects. In the case of a RDBMS, changes to the base database object(s) can occur, for example, as the result of data manipulation language (DML) statement executions against the base database object(s). Such DML statements may include SQL LOAD, INSERT, UPDATE, DELETE, or other SQL DML statements that change or modify database data in the base database objects. When a materialized view becomes stale, the instantiation query of the materialized view can be re-executed against the base database objects to re-instantiate the materialized view. In other words, the materialized view can be "refreshed".
When a materialized view is not stale, a database system may be able to rewrite user queries and execute the rewritten queries against the materialized view. However, if a materialized view becomes stale, then the database system may not be able to rewrite user queries that cannot tolerate the stale data contained in the materialized view. In this case, the database system cannot leverage the efficiencies provided by the materialized view to answer the user queries. Consequently, it can be important to efficient processing of user queries that materialized views are not stale, or at least not stale for extended periods of time.
One naïve strategy is to refresh a materialized view whenever there is a change to a base database object of the materialized view. However, this strategy does not scale well for large database systems with large amounts of data and frequent updates to base database objects. Such a strategy, if employed, might result in the database system continuously refreshing materialized views and constantly starving user queries of computing resources needed to execute the user queries.
Modern database systems are expected to be highly available for user queries. To support high availability, organizational policy may require that certain database maintenance operations be performed only during certain times or certain hours of the day. For example, policy may require that maintenance view refreshes occur during a designated maintenance window which may be, for example, one to two hours in the early morning hours of the day. Further, to prevent maintenance operations from affecting user queries, the maintenance operations may be allocated a capped amount of processing and storage resources to use during the maintenance window to accomplish the maintenance operations so as to prevent the maintenance operations from effectively monopolizing the available computing resources during the maintenance window. Refreshing a materialized view can take a significant amount of time especially when the base database object(s) contain large amounts of data. For example, refreshing a materialized view in a large data warehouse database can take many minutes (e.g., 30 minutes). With all these constraints on maintenance operations, if the database system has many stale materialized views that need to be refreshed during the maintenance window, it may not be possible to refresh all stale materialized views during the maintenance window.
The techniques disclosed herein address this and other issues.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.

Estimating materialized view refresh duration


A magnetic recording medium comprising a substrate and, formed thereon, a magnetic layer comprised of magnetic particles bonded to each other with a thermosetting binder can be improved with respect to the durability by forming a number of fine pores in the magnetic layer and impregnating the fine pores with a lubricant. Particularly, when the fine pores have a diameter of 0.2 .mu.m or less and a rate of the fine pore in area of 3 to 30%, the durability can be improved while maintaining the noise during the recording and reproduction of information on a low level. In preparing the magnetic recording medium having such fine pores, it is preferred that an easily thermal-decomposable additive, such as polyalkylene oxide, be added to a magnetic layer forming paint. A magnetic recording medium having further improved characteristics can be produced by interposing an undercoating layer having a number of fine pores between the magnetic layer and the substrate, allowing the fine pores in the undercoating layer to communicate with the fine pores in the magnetic layer and impregnating the fine pores with a lubricant. In this case, in forming the fine pores, it is preferable to add an easily thermal-decomposable additive to a paint or extract a thermoplastic resin from a layer containing the thermoplastic resin with a solvent.

This invention relates to a magnetic recording medium and a method for producing the same. More particularly, the present invention is concerned with a magnetic recording medium suitable particularly for use in applications, such as magnetic disk devices, which is excellent in wear resistance as well as in durability and reliability, and a method for producing the same.
The magnetic recording medium for use in magnetic devices etc. generally comprises a substrate which may be of various types and a magnetic layer formed thereon. The surface of the magnetic recording medium often suffers a high-rate abrasion by a magnetic head or the like during recording and reproduction of information. The lowering in the performance of the magnetic recording medium due to the above-mentioned abrasion is now a serious problem.
Therefore, it is a common practice in the art to apply a lubricant to the surface of a magnetic layer for the purpose of protecting the magnetic layer from damages due to the abrasion with a magnetic head, etc. A preferable example of such a lubricant known in the art includes a fluorinated oil, such as perfluoropolyether, as disclosed in U.S. Pat. No. 3,778,308. A currently important task is to provide a method for suitably utilizing this type of substance having a lubricity as a lubricant for a magnetic recording medium.
When the above-mentioned lubricant is applied to a magnetic recording medium, such as a magnetic disk, the greater the amount of the lubricant, the more improved the durability of the magnetic recording medium. However, excessive application of the lubricant to the surface of the magnetic layer causes an increase in the adhesion force between the head and the surface of the magnetic recording medium when the magnetic disk device is stopped, which raises problems that the head or the surface of the magnetic recording medium is damaged when the device is restarted or, in an extreme case, the device cannot be driven at all. As mentioned above, the adhesion force between the head and the medium is affected by the amount of the lubricant which is present on the surface of the medium. Hitherto, various proposals have been made with respect to a method for properly controlling the amount of the lubricant applied onto the surface of the magnetic layer which comprises rendering the magnetic layer porous and impregnating the porous layer with a lubricant.
Examples of such proposals include a magnetic disk comprising a porous magnetic layer composed of magnetic particles, a thermosetting resin of epoxyphenol resin system and non-magnetic, inorganic particles, which layer was impregnated with a lubricant (see Japanese Patent Laid-Open No. 104202/1978) and a method of preparing a porous magnetic layer which comprises adding an organic additive, such as liquid paraffin, to a magnetic paint and thermally decomposing and evaporating the additive when a coating film formed is cured (see Japanese Patent Laid-Open Nos. 3435/1981 and 10419/1985).
Further, in recent years, a proposal has been made on a high-density magnetic recording medium comprising a thermoplastic resin suitable for use in floppy disks etc., wherein an undercoating layer containing a lubricant is provided (see Japanese Patent Laid-Open No. 73235/1986).
Among the above-mentioned prior art, the method which comprises rendering a magnetic layer porous and impregnating the porous layer with a lubricant is free from a problem with respect to the lack of the lubricant, because in the conventional magnetic recording medium having a low recording density and a thick magnetic layer, it is possible to impregnate the magnetic layer with a sufficient amount of a lubricant. However, with respect to a magnetic recording medium having a high recording density for which there is an ever-increasing demand on a decrease in the thickness of the magnetic layer, it is necessary to increase the porosity of the magnetic layer in order to impregnate a thin magnetic layer with a sufficient amount of a lubricant. This leads to a problem with respect to the durability of the magnetic recording medium, such as a remarkable lowering in the wear resistance of the magnetic layer.
On the other hand, the above-mentioned prior art method which comprises adding non-magnetic particles to a magnetic coating film raises problems such as an increase in the noise output due to the additive. Moreover, the above-mentioned prior art method which comprises making a porous structure through thermal decomposition of an organic additive is disadvantageous in that a failure to choose a proper additive having a desirable compatibility with the binder of the paint leads to the formation of large pores in the coating film, thus causing noises and errors.
Furthermore, among the above-mentioned prior art methods, the method in which a lubricant is incorporated in an undercoating layer provides a structure suited for a high-density magnetic recording medium having a thin magnetic layer. However, in this method, the positions of the fine pores of the undercoating layer do not always coincide with those of the magnetic layer and, therefore, the fine pores of the undercoating layer do not get through to the surface of the magnetic layer, which makes it impossible to impregnate the undercoating layer with a sufficient amount of a lubricant. Particularly, with respect to a magnetic disk comprising a magnetic layer composed of a thermosetting resin suited for a rigid disk, it is very difficult to impregnate the undercoating layer with a lubricant, because the thermosetting resin of the magnetic layer is very closely hardened.

Magnetic recording medium and method for producing the same


A flywheel power source device for converting electric energy into kinetic energy and for storing the kinetic energy by rotating a flywheel of which rotary shaft is rotatably supported by a bearing mounted in a casing at high speed, wherein the kinetic energy is reconverted into electric energy when necessary; the flywheel power source device is provided with a rotational fulcrum at a bottom of the rotary shaft and a center of gravity of the flywheel being positioned on a line of action of a resultant force of magnetic attractive forces acting on the flywheel.

1. Field of the Invention
The present invention relates to a flywheel power source device which stores kinetic energy by rotating a flywheel at high speed and reconverts the stored kinetic energy of the flywheel to electric energy when necessary.
2. Description of the Related Art
The present applicant has applied a flywheel power source device A which eliminates work of precise leveling when it is installed and is highly resistant to lateral swing (Japanese Patent Application Unexamined Publication No. HEI 7(1995)-322533). This flywheel power source device A (hereinafter referred to as a conventional device A) will be described with reference to FIG. 2.
A flywheel B has a main body part C shaped like an inverted cup and a rotary shaft D provided at the center of the main body part C, the bottom end of the rotary shaft D being rotatably fitted in a pivot bearing F provided on a casing E and the central top of the flywheel B being rotatably fitted on a bearing H provided on the casing E. The bearing H has a structure in which a circular recessed part J of the flywheel B is fitted on a short shaft I of the casing E side, wherein there is a small gap between the short shaft I (to be exact, a ball bearing Ix) and the circular recessed part J.
The flywheel B is provided with a rotor M having an iron core K which is mounted on the inner peripheral surface of the main body part C and is sandwiched by end rings L, L. On the other hand, a stator P is mounted on a bottom wall N of the casing E in such a way that it is opposed to the rotor M of the flywheel B. The stator P includes a fixed base part Q projected from the bottom wall N, an iron core R mounted around the base part Q, and a coil S.
In the conventional device A described above, if voltage is applied to the coil S of the stator P by an external power source, a rotational force is generated by magnetic action caused on the same principle as that of an electric motor to rotate the flywheel B. By rotating the flywheel B at high speed, electric energy is converted to kinetic energy and is stored as the kinetic energy. In this respect, while the flywheel B is being rotated, it is rotated like a top on one point of the pivot bearing F and the circular recessed part J is not in contact with the short shaft I, which significantly reduces the mechanical loss of the flywheel B. Next, when power supply to the coil S is stopped owing to power failure or the like, the kinetic energy of the flywheel B is reconverted to the electric energy on the same principle as a generator and the electric energy is supplied to the external load.
That is to say, in the above-mentioned conventional device A, the rotational fulcrum at the bottom end of the rotary shaft D is aligned with the center of gravity G of the flywheel B, so as to prevent the precession of the flywheel B. (The precession means that the upper end of the rotary shaft D swings along arcs around the rotational center at the bottom end of the rotary shaft D on the principle of a top.) In this regard, if the flywheel B starts the precession, the circular recessed part J is brought into contact with the ball bearing Ix of the short shaft I to increase the mechanical loss, which aggravates efficiency, shortens its life and makes noises while being operated. As the result, the performance of the flywheel power source device is substantially reduced.
The above-mentioned conventional device A is stable in a state in which the flywheel B rotates at high speed and does not start the precession even if it is placed on a slant position or it is swung laterally, and hence solves almost all the problems caused by the precession of the flywheel B. However, it has been found that under special conditions, that is, when the flywheel B in a stop state is started by large voltage, the flywheel B starts the precession and the rotary shaft D is held inclined (the circular recessed part J is held in contact with the ball bearing Ix of the short shaft I) and cannot be returned to the original state. Yet, even in the conventional device A, if the number of revolutions of the flywheel B is gradually increased by applying reduced voltage thereto, the above-mentioned problems do not arise.
In order to find the cause of the problem described above, the conventional device A has been analyzed and it has been found that, as shown in FIG. 2, there was a deviation Z between the center line X of the iron core K of the rotor M on the flywheel B side or the center line Y of the iron core R of the stator P on the casing E side (the center line Y and the center line X usually overlap one another.) and the rotational fulcrum at the bottom end of the rotary shaft D. The deviation Z generates force for inclining the flywheel B around the rotational fulcrum under the special conditions described above.
That is, when the flywheel B is rotated, magnetic attractive forces are applied to the iron cores K, R and it is considered that the resultant force of the magnetic attractive forces is applied to the center lines X, Y of the iron cores K, R. If there is a deviation Z between the center lines X, Y of the iron cores K, R and the rotational fulcrum of the flywheel B, as described above, moment in the direction inclining the flywheel B around the rotational fulcrum acts on the flywheel B in proportion to the magnitude of the magnetic attractive force and the magnitude of the deviation Z. Since the magnetic attractive forces of the iron cores K, R increase in proportion to voltage, when the flywheel B is started by large voltage, the effect of the moment acting on the flywheel B increases. As the result, the flywheel B is being rotated as it is inclined.


An easel and pad pack and method including first and second generally rectangular, planar panels constructed of a unitary, folded paperboard to provide relatively stiff surfaces and having two pairs of opposite sides, tape closing the first and second panels temporarily on two opposite sides to provide an openable holder, the first and second panels being integral on the other two sides, an easel pad removably confined within said panels the first panel being equipped with a generally L-shaped cut defining a stand and arranged for pivotal movement out of the plane of the first panel to provide support for the holder, the first panel also being equipped with a generally C-shaped cut adjacent the L-shaped cut and defining brace means for stabilizing said stand means in non-planar relation to said first panel and an opening in said first panel for hand insertion to carry the pack.

This invention relates to an easel and pad pack and method of using the same and, more particularly, to a device wherein an easel pad is first confined for travel in a holder and later, at the time of use, the holder can be reconfigured to provide a stand-up easel with the pad draped thereover.
The idea of making an easel type stand for tablets or calendars is quite old--see, for example, U.S. Pat. No. 433,635. Over the years, the idea of providing a mount for a display, i.e., an easel, has been the subject of considerable work--see, for example, U.S. Pat. Nos. 3,226,863; 3,370,368 and 4,143,847. None, however, provide the unique combination of advantages provided by the instant invention.
According to the instant invention, first and second four sided planar panels, which are constructed of paperboard, are closed at least temporarily on all four sides to provide an openable pack containing an easel pad. One of the panels is equipped with a generally L-shaped cut which can be pivoted out of the plane of the panel to provide a stand, and further, opening means are provided on one of the panels for hand insertion to carry the pack.
Other objects and advantages of the invention may be seen in the details of construction and operation as set forth in the ensuing specification.


Complex metal oxides are formed by calcining in molecular oxygen such as air at least one bimetallic complex of the formula A[BY] wherein A and B are metals and Y is a ligand associated with B. The bimetallic complexes are precipitated from aqueous solution by a transposition reaction of AX and M[BY] wherein X is a disassociable anion and M is a cationic species. The bimetallic complexes are useful in forming pure complex metal oxide fibers by a process of either dispersing the complex metal oxide or bimetallic precursors in a spinning composition of fluid organic polymer or by imbibing a polymeric fiber with species AX and precipitating out the bimetallic complex by treating the imbibed fiber with a compound containing the BY complex. The process is also useful in forming superconductive complex metal oxides. The use of the bimetallic complex as precursors for the complex metal oxides provide improved mixing of the metal elements on an atomic scale and thus require less severe mixing and annealing conditions to form the oxide.

There are a vast number of complex metal oxides which contain two or more metal cations. The complex metal oxides are present as a homogeneous phase having a generally well defined crystalline structure wherein the metal atoms and oxygen atoms are organized into a compact network according to the requirements of the neutralization of the charges of the metal cations and oxygen anions. The complex metal oxides occur in numerous basic crystalline structural types, the names of which are often derived from the principle compound shown to have that type of crystal structure. For example, spinels which have the structure of the mineral spinel, MgAl.sub.2 O.sub.4, have the general formula AB.sub.2 O.sub.4, and perovskites which have the structure of the mineral perovskite, CaTiO.sub.3, have the general formula ABO.sub.3, wherein A and B are metals and where A and B occupy sites in the crystal lattice. Often, a portion of either or both the A and B sites are replaced with other metal cations.
The complex metal oxides are of growing importance to industry. Spinels and perovskites, for example, are often piezoelectric and ferromagnetic materials and as well are known to have important magnetic, optical and electrical properties. Very recently, it has been discovered that certain complex metal oxides are superconducting at anomalously high critical temperatures (T.sub.c). The crystal structure of one group of these newly discovered superconductive complex metal oxides is believed to be one similar to the crystal structure of K.sub.2 NiF.sub.4 and has a general complex metal oxide formula of A.sub.2 BO.sub.4 wherein A is lanthanum and a small portion of lanthanum sites are replaced with Ba or Sr. B is copper. The crystal structure is a layered one containing a CuO.sub.6 octahedral coordination at the corners like that of a perovskite separated by La,SrO layers. Another complex metal oxide with the formula YBa.sub.2 Cu.sub.3 O.sub.7 also contains perovskite structure and has been found to be superconducting at unusually high temperatures. The high T.sub.c which has been found in these metal oxide superconductors holds much promise that such superconductive materials will be in common use.
Complex metal oxides are generally prepared by coprecipitating the metal salts or by weighing the metal oxides which form the complex metal oxide product to provide the necessary stoichiometric amounts of each metal and repeatedly procedure has yielded the desired complex metal oxide, the method is time consuming, inasmuch as sufficient grinding is necessary to provide a homogeneous mixture of the respective metal cations on an atomic scale. Further, it is often difficult to obtain complex metal oxides in which the respective metals are present in the proper weight ratio to provide the desired crystalline structure such as a spinel, perovskite, etc. To prepare complex metal oxides from a mixture of separate metal salts or oxides, the amount of the respective metal salts or oxides, as well as the mixing and calcining conditions all have to be considered to obtain the desired structure. Typically, crystals of the complex metal oxides obtained by the prior art techniques contain several metallic phases, including one or more metal oxide phases of each respective metal, the desired homogeneous complex metal oxide phase, and other complex metal oxide phases. Not surprisingly, the presence of non-homogeneous metal oxide phases has been reported in the preparation of the superconducting complex metal oxides. For example, it has been reported that preparations using the traditional method of coprecipitation have not proved satisfactory for the superconducting YBa.sub.2 Cu.sub.3 O.sub.7 composition. The presence of a non-superconducting phase, the result of inhomogeneous stoichiometry, is a recurring problem in methods that rely on mechanical mixing and, apparently, even the coprecipitation procedure that generally gives good dispersion can result in impure material Accordingly, a method that disperses the metals on an atomic scale in the desired stoichiometry is needed to overcome this problem.
A technique for forming perovskites, in particular, the preparation of rare earth ferrites and analogous cohalt compounds has been reported by Bell Telephone Laboratories, Gallagher, P. K., Materials Res. Bull., 3, 1968, pp. 225-32, in which rare earth ferrocyanide or cobalticyanide compounds, e.g., LaFe(CN).sub.6 XH.sub.2 O were precipitated from aqueous solution. For example, lanthanum chloride was dissolved in water and precipitating agents such as ammonium ferrocyanide and potassium cobalticyanide were added Upon calcination of the precipitate in air at 1,000.degree. C., pure perovskites of LaFeO.sub.3 and LaCoO.sub.3 were formed with no evidence of La.sub.2 O.sub.3, Fe.sub.2 O.sub.3 or nonperovskite mixed metallic compounds The advantages of the technique are the nearly perfect control of the rare earth to transition metal ratio at unity, complete homogeneity of the metallic compounds, good purity and ease of preparation because the normally required repetitive grindings and heating are eliminated, and finally a means of control over the particle size of the desired material by means of the choice of conditions for calcination.
An analogous system has been reported for forming BaTiO.sub.3. The method involves reacting barium chloride with potassium titanyl oxylate in which calcination of the precipitated barium titanyl oxylate results in the barium titinate (BaTiO.sub.3), Journal of the American Ceramic Society, Vol. 46, No. 8, Aug. 21, 1963, p. 359, and Journal of Research of the National Bureau of Standards, Vol. 56, No. 5, May 1956, p. 289. None of these articles address the formation of complex metal oxides other than perovskites in which the metals are present in a 1:1 ratio.
In recent years the formation and use of inorganic fibers, in particular, metal oxide fibers, have received increasing attention. Such interest may be traced at least in part to new demands of industry for fibers capable of withstanding elevated temperatures without deleterious effects. The growing aerospace industry, for example, provides many applications for light and strong heat resistant fibrous materials.
The formation of inorganic metal-containing fibers has required elaborate and time-consuming procedures inasmuch as such compounds possess high melting points which render melt-spinning either impossible or extremely difficult. Accordingly, procedures for forming inorganic fibers usually involve the addition of metal or metallic compounds to polymeric spinning solutions or to already spun polymeric fibers and subsequent thermal conversion to metal carbides, metal nitrides, metal oxides, etc. wherein the polymeric material is either used as a carbon source for forming carbides or is simply used as a carrier for the metallic components and consumed during thermal treatment.
In the formation of metal oxide fibers, the metals are often present in the form of inorganic or organic salts which are added to the spinning polymer solution or such salts are imbibed in preformed polymeric fibers. Upon calcination in air, the metal salts are converted to the respective metal oxides. Examples of such procedures are disclosed in U.S. Pat. Nos. 3,846,527; 4,010,233, 4,485,085 and 4,541,973. The two latter patents are directed to the formation of ferrimagnetic spinel fibers. U.S. Pat. No. 4,541,973 adds the powdered spinel into a spinning solution. In the methods described in the other mentioned patents, the metals are added as metal salts containing the metal species in the cationic form. Even in the formation of complex metal oxide fibers, the respective metal compounds are added separately to the spinning solution or imbibed into the preformed fibers in the form of various metallic salts in which each metal is a cationic species. Exact control over the proper weighing of the various metal salts are thus needed to form the desired metal oxide product. As stated above, it is often difficult to provide the stoichiometric amount of each metal when added in the form of metal salts so as to yield the desired mixed metallic oxide. It is difficult as well to provide the proper mixing of the metal salts and calcining conditions, thus, oxide phases other than the desired homogeneous complex metal oxide phase are usually formed.
In view of the growing applications for complex metal oxides it would be worthwhile to provide complex metal oxide fibers and adapt such fibers for a wide range of prospective applications involving optics, electronics, as well as piezoelectric, magnetic, and superconductive applications. However, there remains a need for a new and improved process for the production of complex metal oxide fibers where the composition of the complex metal oxide can be more readily controlled to yield the proper ratio of the metal cations and form increasingly purer homogeneous complex metal oxide phases.
Accordingly, it is an object of this invention to provide an improved process for the production of complex metal oxide fibers.
It is another object of this invention to provide a process for the production of complex metal oxide fibers of improved purity.
Still another object is to provide a process for the production of complex metal oxide compositions of improved purity.
Yet another object is to provide an improved process for producing superconductive complex metal oxide compositions.
Other objects and advantages of the present invention shall become apparent from the accompanying description of the invention and appended claims.

Process for producing a superconductive complex metal oxide


A technique and associated circuitry are provided for measuring a buffered write head voltage, and measurement of thin-film write head DC head voltage in a disk-drive, along with a procedure for calibrating/optimizing the write current amplitude based on the measurement of the buffered write head voltage. A write driver includes a terminating resistor, coupled to the write element of a transducer head in a disk drive, wherein controlling the write current of the write driver includes the steps of measuring the resistance RW of the terminating resistor; measuring the resistance RC of the write element; and generating the write current amplitude based on the resistances RC and RW.

The present invention relates generally to read/write transducer heads, and in particular to measuring thin-film write head DC head voltage in a disk drive.
In recording of data on magnetic media with transducer heads, such as in disk drive data storage systems, the magnetic recording performance is sensitive to write current amplitude in the head. As data rates and recording densities are pushed to the limits of technology it becomes crucial to overall cost and performance to extend the performance of the overall recording system.
As shown by example in FIG. 1A, in disk drives with magneto-resistive (MR) heads each transducer head 10 includes a thin-film writer element (write coil) 12 connected to a writer driver 14 in a preamplifier (Preamp) 16 via an interconnect 18, and a read element (MR Read Sensor) 20 connected to a read amplifier 22 in the preamplifier 16, via the interconnect (transmission line) 18.
The write driver 14 employs a low-impedance output stage followed by a series termination resistance to drive the write current IWC out to the write element 12. The series termination resistance is used to terminate the transmission line 18 from the write driver 14 out to the thin-film write element 12. The write current amplitude IWC in the transducer head generated by the write driver 14 is one of the critical parameters for magnetic recording. A consequence of using the low-impedance output buffer in the write driver 14 is that the amplitude (magnitude) of the write current is sensitive to the DC resistance of the thin-film write element 12 as well as the interconnects 18, and the absolute value of the termination resistance. In order to more accurately predict the magnitude of the write field output from the head 10, it is necessary to optimize (calibrate) the output voltage of the low-impedance write driver 14, and hence the write current IWC.
Further, if the amplitude of the write current is not well controlled across a population of transducer heads 10, preamplifiers 16 and interconnects 18, then the overall system performance versus cost is subject to the limits imposed by the worst case (lowest) write current. The lowest write current of a population of transducer heads 10 results from the combination of the highest resistance of each of the following components: the thin-film writer 12, the interconnect 18 and the termination resistance of the voltage-mode (matched-impedance) write driver 14. In conventional disk drives, over-driving the remaining population of heads 10 can result is a number of problems with the write process such as poorly defined write field as a result of over-driven heads, excess power consumption within the preamplifier 16, and increased write-to-read coupling.
There is a need, therefore, for a method and apparatus for calibrating the write current in a transducer head. There is also a need for a method of calibrating output voltage of low-impedance write drivers to generate the desired write current. There is also a need for a method of overcoming the uncertainty in write current amplitude that results from the use of conventional voltage-mode or matched-impedance write driver architecture.
The present invention satisfies these needs by providing method and apparatus to optimize (calibrate) the low-impedance write driver voltage, and hence the write current. The present invention allows measurement of a thin-film write head DC head voltage within a disk-drive, and calibration of the write current based on the measured voltage.
In one embodiment, the present invention provides a technique and associated circuitry for measuring the buffered write head voltage (e.g., measurement of thin-film write head DC head voltage) along with a procedure for controlling (calibrating) the write current amplitude generated by the write driver based on the measurement of the buffered write head voltage. The write driver includes a terminating resistor, coupled to the write element of a transducer head in a disk drive, wherein controlling the write current of the write driver includes the steps of: measuring the resistance RW of the terminating resistor; measuring the resistance RC of the write element; and generating the write current amplitude based on the resistances RC and RW.
In one example, the write driver further includes a voltage source and a switch for electrically connecting the voltage source in series with the terminating resistor RW and the write element, such that the steps of measuring RW and RC further include the steps of: with the voltage source disconnected, connecting a current source (IWB) across the parallel combination of the terminating resistor and the write element, and measuring a resulting first voltage across the parallel combination of the resistances RC and RW; with the current source disconnected, connecting the voltage source (VW) in series with the terminating resistor and the write element, and measuring a second voltage across the series combination of the resistances RC and RW; and determining the values of RC and RW based on said two measured first and second voltages. Generating the write current further includes the steps of adjusting the voltage VW of the voltage source to generate a desired write current IWC based on the resistances RC and RW, such that: IWC=VW/(RC+RW).
Conventionally, the write current amplitude is subjected to an unknown variation due to process tolerances in the head and preamplifier. These variances can degrade the write process by an unknown disturbance function. The present invention overcomes the uncertainty in setting the write current amplitude that results from the use of a voltage-mode or matched-impedance write driver architecture, by providing a method and practical circuits for calibrating the write current amplitude against a current source (IWB), wherein the current source (IWB) is based on a precise reference current (REF) independent of the DC resistance of the thin-film write head. As such, according to the present invention, the write current amplitude can be accurately controlled without sensitivity to the DC resistance of the head plus interconnect resistance (RC) or the output impedance of the write driver (RW).

Method and apparatus for controlling write current in writer drivers