Capacitive micromachined ultrasonic transducers (CMUTs) having a pre-charged floating electrode are provided. Such CMUTs can operate without an applied DC electrical bias. Charge can be provided to the floating electrode after or during fabrication in various ways, such as injection by an applied voltage, and injection by ion implantation.

Capacitive micromachined ultrasonic transducers have been extensively investigated for many years in connection with various applications. In operation, a CMUT is typically biased using a DC electrical voltage that determines the operating point of the device. CMUT signals in operation are typically AC electrical or acoustic signals. For example, an applied AC electrical signal leads to emission of acoustic radiation from the CMUT (e.g., acoustic transmission), and an AC acoustic signal incident on a CMUT leads to generation of an AC electrical signal on the CMUT (e.g., acoustic reception).
In some cases, the use of a DC electrical bias in combination with AC signals on a CMUT can cause undesirable complications. Accordingly, it would be an advance in the art to reduce or eliminate the need for an applied DC bias in CMUT operation.

Pre-charged CMUTs for zero-external-bias operation

The Board of Trustees of the Leland Stanford Junior University


A method for testing an CMOS ternary content addressable memory (TCAM) device includes a match line test to identify stuck match lines, a pull down test to identify weak pull downs (from the match line to ground), and a row-by-row match test. During the row-by-row match test a failed cell can be repaired or the row associated with the failed cell can be disabled. A failed cell or its associated row can also be repaired or disabled, respectively, after the test. Additionally, individual CAM cells which are identified as being defective can be further tested to identify which component of the CAM cell failed.

An essential semiconductor device is semiconductor memory, such as a random access memory (RAM) device. A RAM allows a memory circuit to execute both read and write operations on its memory cells. Typical examples of RAM devices include dynamic random access memory (DRAM) and static random access memory (SRAM).
Another form of memory is the content addressable memory (CAM) device. A CAM is a memory device that accelerates any application requiring fast searches of a database, list, or pattern, such as in database machines, image or voice recognition, or computer and communication networks. CAMs provide benefits over other memory search algorithms by simultaneously comparing the desired information (i.e., data in the comparand register) against the entire list of pre-stored entries. As a result of their unique searching algorithm, CAM devices are frequently employed in network equipment, particularly routers and switches, computer systems and other devices that require rapid content searching.
In order to perform a memory search in the above-identified manner, CAMs are organized differently than other memory devices (e.g., DRAM). For example, data is stored in a RAM in a particular location, called an address. During a memory access, the user supplies an address and writes into or reads the data at the specified address.
In a CAM, however, data is stored in locations in a somewhat random fashion. The locations can be selected by an address bus, or the data can be written into the first empty memory location. These data written into the memory location are called as "rules". Every memory location includes one or more status bits which maintain state information regarding the memory location. For example, each memory location may include a valid bit whose state indicate whether the memory location stores valid information, or whether the memory location does not contain valid information (and is therefore available for writing).
In a ternary CAM every bit of data has a Data and Mask bit. Data for a bit is the data that has to be compared for that bit, this data is however qualified by a mask bit which is used as a control bit for each of the data bit to enable or disable it from comparison. When the bit is masked it is called don't care bit. Following table shows a one possible data and mask scheme
NameDataMaskNo Mask01"0"No Mask11"1"Mask "0"00Mask "1"10Once information is stored in a memory location, it is found by comparing every bit in a memory location with corresponding bits in a comparand register. When the content stored in the CAM memory location does not match the data in the comparand register, a local match detection circuit returns a no match indication. When the content stored in the CAM memory location matches the data in the comparand register, the local match detection circuit returns a match indication. If one or more local match detect circuits return a match indication, the CAM device returns a "match" indication. Otherwise, the CAM device returns a "no-match" indication. In addition, the CAM may return the identification of the address location in which desired data is stored or identification of one of such addresses if more than one address contained matching data. Thus, with a CAM, the user supplies the data and gets back an address if there is a match found in memory. In a ternary CAM when data with mask are stored at various locations and searches are done with a data then for a given data, there is a possibility of multiple rules getting matched for a given key. In a Ternary CAM the process of resolving multiple matches to generate a single match output is called priority resolution. There are many schemes of priority resolution two of the ones are highest order priority or lowest order priority. Highest Priority resolution is where the largest address matched is given out and the lowest order priority is where the smallest address match is given out.
FIG. 1 is a circuit diagram illustrating a conventional SRAM based ternary CAM cell 100. The CAM cell 100 includes a data storage portion 110, which is comprised of an access transistor D0 and a pair of inverters D1a, D1b, arranged in as shown in FIG. 1. The gate of the access transistor D0 is coupled to a word line WL, and one source/drain terminal of the access transistor D0 is coupled to a bit line BL. Thus, a voltage level indicative of a logical value that is placed on the bit line BL is gated across the access transistor D0 when the word line WL is high. This sets the voltage at node D to the voltage equal to the logical value. The two inverter structure D1a, D1b subsequently maintains the logical value at node D and a complement of the logical value at node D#.
A match section 120 of the CAM cell 100 is comprised of transistors M1, M1#, M2, M2# and M3, which controllably couple the match line ML to ground in certain situations. In the CAM cell 100, a "no-match" condition is detected if the match line ML remains at a precharge potential, which a "match" condition is detected if the match line ML is pulled to ground during the match operation. Typically, the detection of the state of the match line ML is performed by a sense amplifier (not illustrated).
Transistor M3 has one source/drain terminal coupled to the mach line ML and another source/drain terminal coupled to a four-transistor circuit formed by transistors M1, M1#, M2, and M2#. The gate of transistor M3 is coupled to a register M, which stores a mask value. The register M and transistor M3 are present when CAM cell 100 is a ternary CAM (TCAM) cell. TCAM cells permit the search expression to include "don't care" bits, while binary CAMs enforce a match/no-match evaluation of every bit. If CAM cell 100 were a binary CAM, transistor M3 and register M would not be present and the source/drain terminals of transistor M2 and M2# illustrated as being coupled to a source/drain terminal of transistor M3 would instead be coupled directly to the match line ML.
Transistors M1, M1#, M2, and M2# form a comparison circuit. The gates of transistors M2, M2# are respectively coupled to search data lines SD and SD#. The search data is placed on the line SD while the complement of the search data is placed on the line SD#. Similarly, the logical value stored at node D is coupled to the gate of transistor M1 while the complement of that logical value stored at node D#is coupled to the gate of transistor M1#. In this manner, the comparison structure will pull the match line ML voltage from its precharged level to ground if and only if the search data on line SD matches the data stored at node D or the complement of the search data on line SD# matches the complement of the data stored at node D, assuming that transistor M3 is conducting. If transistor M3 is not conducting, the match line ML potential will remain at its pre-charged level.
When a memory device is manufactured, it must be tested. Although testing is time consuming and costly, testing is required to identify errors in the device. If errors are not identified, the use of the memory device can corrupt data. In addition to error detection, an ideal test should also be able to inform the tester as to which portion of a CAM cell is defective. If many defects are isolated to a same problem area, the data can form the basis of improving the device fabrication process. Accordingly, there is a need for a method to efficiently test CAM cells in a CAM device and to identify which component of a defective CAM cell failed.


An engine system is provided. The engine system includes an ambient air pressure sensor configured to generate a signal indicative of a pressure of ambient air. The engine system also includes an operational parameter sensor configured to generate a signal indicative of one or more operational parameters associated with the engine. The engine system further includes a controller communicably coupled to the ambient air pressure sensor and the operational parameter sensor. The controller is configured to receive the signal indicative of the pressure of ambient air and the signal indicative of the one or more operational parameters associated with the engine. The controller estimates the temperature of at least one of a valve, a piston, a liner, a cylinder head, and a pre-chamber of the engine as a function of the received signals and parameters associated with fuel delivery in a single fuel cycle of the engine.

For a given configuration, an Internal Combustion Engine (ICE) operating at a higher altitude tends to reach higher temperatures as compared to the engine operating at a lower altitude when producing a same amount of power. This may cause overheating of engine components, such as, for example valves, pistons, and other in-cylinder components associated with the engine. Overheating may in turn lead to premature failure of the valve. In order to prevent overheating, the engine is derated by reducing a fuel supply to the engine. Typical calibration strategies consider constraints such as exhaust gas temperature, peak cylinder pressure, turbocharger speed, compressor outlet temperature, and smoke opacity. Such strategies fail to consider a temperature of the valve, a piston, a liner, a cylinder head, and a pre-chamber, which in some situations may be a limiting factor in the system.
Some prior attempts to account for the valve temperature limitations include correlating it with the exhaust gas temperature. Such an approach is typically inaccurate, since the valve temperatures are more aligned with peak cylinder temperatures during a cycle than the exhaust gas temperature. Other derate strategies may involve advancing injection timing for the sake of reducing the exhaust gas temperature. This may lead to a more substantial pre-burned spike, relatively higher exhaust gas temperatures and in turn cause an increase in the temperature of the valve.
U.S. Pat. No. 5,483,941 discloses a method for use with a vehicle including a multi-cylinder internal combustion engine having exhaust valves. The method controls the temperature of the exhaust valves during fuel cutoff modes of engine operation utilizing a bit pattern representation of the engine cylinders. The method includes cutting off the fuel delivered to the cylinders in an indexed cylinder firing pattern to vary which cylinders receive fuel so as to maintain acceptable exhaust valve temperature levels. The method may also include operating the engine with a lean air/fuel ratio so as to maintain acceptable catalytic converter temperature levels.

System and method for estimating and controlling temperature of engine component


In one embodiment, the present invention is directed to a method for processing boundary information of a graphical object. The method may comprise: receiving a graphical image that comprises the graphical object, wherein the graphical object is defined by at least the boundary information; determining a plurality of vertices from the boundary information; and creating an approximated boundary utilizing at least the plurality of vertices, the graphical image, and a predetermined function that is operable to detect a contour between a pair of vertices by analyzing the graphical image.

Shape coding is utilized by a number of multimedia applications to enable various image processing techniques. For example, shape coding is utilized by digital photograph editor applications. After a shape is coded or defined, the digital photograph editor applications permit a user to modify only the graphical information inside the encoded shape. For example, the graphical information inside the shape may be "cut-and-pasted" onto a new background.
Various data structures and algorithms have been employed to encode shapes. For example, region-based approaches have been developed. Region-based schemes encode an object by a support map which is a binary image with ones representing the object region and zeros representing the background region. In this manner, the shape coding is converted to a binary image coding problem. Exemplary region-based algorithms include the algorithms developed by Joint Binary Images Group (JBIG), JBIG2, and Moving Picture Experts Group-4 (MPEG-4).
Boundary-based algorithms are also frequently utilized. For example, a user may manually select each pixel of a boundary of an object in a graphical image. The coordinates of each selected pixel may be stored to define the boundary. Moreover, various schemes have been utilized to approximate the boundary defined by stored coordinates such as chain coding, polygon approximation, high-order curve fitting (splines) approximation, and combined polygon-spline approximation. The approximation algorithms reduce the amount of data required to represent the boundary to varying degrees.
However, known shape encoding algorithms are independent of the algorithm utilized to present the underlying graphical image (e.g., bit map, video image, and/or the like). Accordingly, known shape encoding algorithms require an appreciable amount of data in addition to the underlying graphical image.

Systems and methods for processing boundary information of a graphical object

Hewlett-Packard Development Company, L.P.


Systems and methods are provided for indicating recommended settings for data acquisition in a medical scanner. A scan protocol including a first parameter is identified. A first subset of values is determined for the first parameter as a function of the scan protocol. A first plurality of values is displayed for the first parameter with the first subset of values highlighted. A first selection is received of a first selected value for the first parameter. Image data is generated using the first selection.

The present embodiments relate to providing guidance for performing medical imaging tasks. Different medical imaging systems use different settings and parameters for acquisition and reconstruction of images. For a computed tomography (CT) example, to reach a task and user-specific image quality, a user has to select optimized parameters for CT acquisition and corresponding reconstruction choices. Currently, there is limited guidance as to which parameter settings are good or reasonable.
A similar situation occurs when protocols and reconstruction settings are transferred from one scanner to another scanner. In a medical environment, as various imaging systems are different (for example, different manufacturer, models, software versions), an exact match of parameter settings is often not possible. Users may have to discover optimal parameter settings on their own from lists of parameters. The discovery process may not be reasonable from a safety perspective or for producing a subjectively good, desirable image quality. Instead of providing just lists of options for the different parameters, some guidance is needed for improved image quality, consistency, and workflow optimization.

Highlighting best-matching choices of acquisition and reconstruction parameters


Methods and apparatuses for controlling systems of cryogenic centrifugal compressors. A predetermined curve in the form of a first parameter as a function of a second parameter is selected. The first parameter represents the rotational speed of a compressor, and the second parameter represents the mass for rate of that compressor. The speed of rotation of a downstream compressor is regulated according to the value of the suction pressure of an upstream compressor and a variable set pressure. The variable set pressure is regulated according to both actual value of the first parameter for a downstream compressor, and the theoretical value of this parameter. The theoretical value is determined from a predetermine curve using the value of the second parameter.

The invention applies for example to the cooling of superconducting components of particle accelerators.
The pressures discussed here are absolute pressures.
The cooling of the superconducting components of particle accelerators requires the use of a fluid in equilibrium at low temperature and at low pressure, particularly helium, of which the vaporization provides the necessary heat transfers.
The refrigeration installations used in these applications comprise liquefaction units which, using helium gas at atmospheric pressure and ambient temperature, are able to supply liquid helium in equilibrium with its gas phase at temperatures of about 2K and at pressures of about 30 mbar.
The power dissipated by the superconducting components vaporizes helium, which must be recompressed in order to be recycled to the liquefaction unit, of which the inlet pressure is set at a value in the range of atmospheric pressure. The role of the compression line is to control its own inlet pressure and hence the liquid helium temperature.
At present, only compression lines with centrifugal compressors in series are suitable for compressing, at the desired compression ratio, a sufficient flow rate for obtaining medium or high refrigeration capacities. The centrifugal compressors are accordingly dimensioned to provide the desired compression ratio for the nominal mass flow rate of helium gas vaporized by the superconducting components operating at full capacity.
During startup, waiting periods, or the operation of the superconducting components at reduced capacity, the cooling requirements decrease, and this is accompanied by a commensurate reduction of the mass flow rate of helium gas vaporized and introduced into the compression line. This decrease in the mass flow rate is liable to cause stalling of the compressors, which must provide a constant compression ratio.
In the case of compressors operating at ambient temperature, the above problem is solved simply by adjusting the flow rate of each compressor. For this purpose, each compression stage is provided with a recycle line, which can be used to increase the mass flow rate of each compressor, and thereby to prevent its stalling.
However, this solution cannot be applied to cryogenic compressors mounted in series, because the solution whereby gas is recycled between each compression stage in order to adjust the operating point of each compressor would require intermediate coolings, would prove to be extremely complicated to implement, and would remove cooling capacity from the refrigerator.
Such cryogenic compressors are also subject to specific contingencies, which must be taken into account for their control.
Thus, given that this concerns a cryogenic system, the temperature of each of the compression stages is variable.
Furthermore, given that the flow treated by the compressors is sent to a refrigerator, the latter imposes a flow rate limitation, corresponding to the flow rate which it can accept.
Moreover, the control process is not time-dependent. In fact, the flow rate of gas to be treated results from the evaporation of a portion of liquid, for which the pressure is decreased, this flow rate being obtained by appropriately varying the suction pressure of the first compression stage.
Such a variation is linked to the various parameters of the liquid, on which the pumping is carried out, that is, in particular, the quantity, superheat state, or the residual power dissipated in this liquid.

Method and installation for controlling at least one cryogenic centrifugal compressor compression line

L'Air Liquide, Société Anonyme à  Directoire et Conseil de Surveilance pour l'Étude et l 'Exploitation des Procédés Georges Claude


A wireless cryptographic fill system includes a fill device and a host portion. The fill device is configured to store one or more cryptographic keys and related data in memory therein. The host portion is coupled to a host processor, such as a secure radio configured to perform secure operations utilizing the cryptographic key. The fill device and the host portion are configured to communicate wirelessly with each other. Wireless communications may be accomplished optically, magnetically, inductively, capacitively, via radio frequency, or via bar codes. In one embodiment, the fill device is stylus-shaped, and is inserted into (or positioned proximate) the host portion to achieve wireless communications. In another embodiment, the cryptographic fill device is card shaped, and is inserted (or swiped) into a slot on the host portion to achieve wireless communications.

The present invention is generally related to secure communications systems, and more specifically related to loading cryptographic keys into equipment containing cryptographic functionality such as secure radio equipment.
As communication systems become more sophisticated with complex communication services and capabilities, it is important to keep information secure. Trends in the communication marketplace have clearly defined the need for security for both commercial and military markets. One way to keep information secure is to encrypt information prior to transmission and decrypt received information. Typically, a common cryptographic key (common to both the transmitter and the receiver) is used to encrypt and decrypt the information. However, in many systems, such as military systems, the key is kept separate from the receiver/transmitter until it is needed to ensure security in the event that the receiver/transmitter is subject to unauthorized access. In these systems, the cryptographic key is loaded (filled) into the receiver/transmitter via a fill device. When the receiver/transmitter is turned off, the cryptographic key may be erased, depending on the design of the system.
Current fill devices suffer many disadvantages. Typical fill devices are bulky, conspicuous, and not particularly suited for tactical, covert environments. The size of a typical fill device can range from approximately the size of several packs of cigarettes to the size of a laptop computer (or even larger). Fill devices for military use are known in the art. Examples include the KYK-13, AN/CYZ-10, KYX-15, and KOI-18. FIG. 1 is an illustration of the AN/CYZ-10 (prior art), also known as the Data Transfer Device.
Large, bulky fill devices are difficult for personnel to carry. This is a particular disadvantage in situations such as military operations requiring personnel to carry fill devices on maneuvers. Also, in situations in which military personnel are trying to remain inconspicuous, such as going through commercial airports during covert operations, large, bulky fill devices are easily spotted by airport security personnel, and may lead to questions being asked that could jeopardize the mission.
Current fill devices require that the fill device be mechanically connected to the transmitter/receiver via an electrical connector, such as bayonet lock connectors and threaded connectors. In the field, or during an operation in which little time is available, connecting and disconnecting the fill device to the transmitter/receiver can take too long, also possibly jeopardizing the mission. Also, these types of connectors are subject to weather conditions which may cause corrosion and interference with the operation of the connector (e.g., dirt in the threads). Furthermore, due to the covert nature of many military operations, the cables connecting the fill device with the transmitter/receiver must be shielded to prevent unauthorized disclosure of the information being transferred, e.g., the encryption key. Shielded cables and connectors tend to be heavy, bulky, stiff, and difficult to quickly connect and disconnect. Current fill devices also are not hermetically sealed due to the mechanical requirements for switches, batteries, connectors, etc. This lack of seal compromises the reliability of the internal electronics in harsh environments.
An improved cryptographic fill system is desired.
In one embodiment, a cryptographic fill system in accordance with the present invention includes a fill device configured to store one or more cryptographic keys, a host portion configured to be coupled to a host processor, and wireless communications means for providing communications between the fill device and the host portion.
In another embodiment, wherein the cryptographic fill system includes a fill device and a host portion, and the host portion is configured to be coupled to the host processor, a method for wirelessly providing a cryptographic key from a cryptographic fill device to a host processor includes positioning the fill device proximate the host portion, activating at least one of the fill device and the host portion for starting wireless communications between the fill device and the host portion, and wirelessly providing the cryptographic key to the host processor.

Wireless cryptographic fill system and method


A leaf blower to be worn by a user. The leaf blower including a frame having a back plate defining a back plate plane and a blower system coupled to the frame. The blower system includes a motor having drive shaft, the drive shaft defining an axis, and the axis forms an angle with respect to the back plate plane between about 5 degrees and about 35 degrees.

The present invention relates to a leaf blower and, more particularly, to a backpack leaf blower.
A leaf blower is a gardening tool that propels air out of a nozzle to move yard debris, such as leaves, twigs, and the like. Typically, these devices include a power source, such as an internal combustion or electric motor, driving a blower that in turn exhausts air under pressure. In most leaf blower designs, the air exhausted from the blower must travel through some type of elbow or bend before it can be directed through the output, reducing efficiency of the device. Furthermore, existing leaf blower designs generally position the motor (usually the heaviest part of the leaf blower) far away from the user's back, increasing the strain on the user and making the device uncomfortable to wear.

Techtronic Outdoor Products Technology Limited