An x-ray source assembly capable of producing x-rays suitable for use in medical, explosive detection, and other areas. The assembly includes a housing having a two-part socket member (which holds the assembly's x-ray tube therein) positioned therein. The two-part housing defines an opening through with the tube's x-rays are emitted.

X-ray source assemblies are known in the art, and have been widely recognized as being extremely valuable tools for use in a variety of applications, ranging from the medical field to, more recently, the detection of explosives. With respect to the medical field, for example, such assemblies are commonly used in areas such as diagnostic and therapeutic radiology. With respect to explosives detection, such assemblies have more recently been adapted for use within detection equipment produced by the Assignee of this invention for use in detecting explosives in luggage moving on airline luggage conveyors and the like. Examples of such equipment are defined in the foregoing co-pending patent applications.
Generally speaking, the operation of x-ray source assemblies such as those defined herein is similar. In general, x-rays, or x-ray radiation, are produced when electrons are produced, accelerated to high speeds, and then stopped abruptly. Typically, this procedure occurs within an x-ray tube which includes an evacuated envelope which is usually comprised of glass or a combination of metal and glass. A cathode structure is typically located within the envelope for producing the electrons when the tube is activated. An anode structure is located at a short spaced location (gap) from the cathode structure and designed for receiving electrons emitted by the cathode. A voltage potential is applied between the cathode and the anode which causes the electrons emitted from the cathode structure (also called a filament) to form a thin stream of beams which are accelerated to a very high velocity towards a surface (also called a target) on the anode structure. This anode target surface is comprised of a refractory metal having a high atomic number, so that when the electrons strike it, at least a portion of the resulting kinetic energy is converted to electromagnetic waves of very high frequency, these being the x-rays. The resulting x-rays emanate from the target surface, and are then collimated for penetration into an object, such as the aforementioned luggage moving along a conveyor. As mentioned, when used within explosive detection equipment, these x-rays pass through the luggage, are detected and then analyzed so as to determine the nature of the object or objects within the luggage.
Generally speaking, a relatively minor part of the input energy provided the x-ray assembly results in the production of x-rays. A majority of the kinetic energy resulting from the electron collisions at the target surface is converted into heat, which can reach extremely high temperatures. The heat is absorbed by the anode and is conducted not only to other portions of the anode assembly, but to the other x-ray tube components within the evacuated envelope and, also, to the other parts of the x-ray assembly holding the x-ray tube therein. Over time, this heat can damage the anode, the anode assembly, other tube components and/or other internal parts of the overall assembly, and can reduce the operating life of the x-ray tube and/or the performance and operating efficiency of the tube.
Several approaches have been used to help alleviate problems arising from the presence of these high operating temperatures. For example, in some x-ray devices, the x-ray target, or focal track, is positioned on an annular portion of a rotational anode disk. The anode is in turn mounted on a supporting shaft and rotor assembly that can then be rotated by a motor. During operation, the disk is rotated at high speeds, causing the focal track to continuously rotate into and out of the path of the electron beam such that the electron beam is in contact with any given point along the focal track for only short periods of time. This allows the remaining portion of the track to cool during the time that it takes to rotate back into the path of the electron beam, thereby reducing the amount of heat absorbed by the anode. Although anode rotation reduces the amount of heat present at the focal spot on the focal track, a large amount of heat is still transferred to the anode, the anode drive assembly, and other components within the assembly housing.
Another approach has been to place the housing that forms the evacuated envelope within a second outer metal (e.g., lead) housing which acts as a radiation shield to prevent radiation leakage and further serves as a container for a cooling medium, one well known such medium being oil (also referred to as dielectric oil due to its lack of electrical conductive properties). It is known in the art to use such oil and circulate it by a pump over the outer surface of the inner evacuated housing. As heat is emitted from the x-ray tube components (anode, anode drive assembly (if used), etc.), it is radiated to the outer surface of the evacuated housing, and then at least partially absorbed by the coolant fluid. The heated coolant fluid is then passed to some form of heat exchange device, such as a radiating surface, to allow much of the heat to be removed. The fluid is then re-circulated by the pump back through the outer housing and the process repeated. Oil may also serve as an electrical insulator and reduce the possibility of electrical arcing between the evacuated housing and the outer housing. It is thus essential that the oil be properly circulated within the x-ray assembly.
Some known x-ray sources have eliminated the use of an outer housing and oil as a coolant/dielectric medium. For example, some solutions utilize forced air to remove heat from the evacuated housing and its components. However, these approaches have not been entirely satisfactory for a variety of reasons. For example, known x-ray generating devices that utilize forced air as a cooling medium are adapted for high voltage x-ray applications; such applications typically utilize a 150 kV operating potential, or higher, between the anode and cathode. High operating voltages result in higher operating temperatures, and to ensure sufficient heat removal with air convection, these x-ray tubes typically are equipped with fins, or channels formed on the outer surface of the evacuated envelope so as to enhance heat removal. Understandably, this need for additional structure increases manufacturing complexity, and involves additional physical space requirements for the assembly.
Another concern related to x-ray assemblies and particularly those which operate at relatively high voltages (e.g., those above 150 kV) is the potential for unacceptable arcing between the anode and cathode structures. Such arcs can of course destroy the inner components of the x-ray tube and cause other damage to the overall system. X-Ray tubes have a high internal vacuum and, as a result, the metal internal parts may contaminate the vacuum when the tube is not in use. Normally, such contamination is recombined during the tube's normal operation. If this does not successfully occur, however, the contamination may cause what is referred to as "micro-arcing" or even a major arc. In most cases, micro arcs merely cause an anomaly in the tube's detected data and will self-cure as the tube continues to operate. A major arc, however, will further contaminate the vacuum each time it occurs. Running the tube for a given time period (depending on the extent of arcing damage) will degas the tube so that it can be returned to full service. If the damage is extensive, however, the tube will require replacement. In conventional tube designs, the power supply serves to detect arcs, as evidenced by excessive current flow.
Examples of various x-ray assemblies are described in the following documents.
In U.S. Pat. No. 3,473,028, there is described a relatively small radiographic examination apparatus which includes a housing having walls of a dielectric material, an electrically conductive liner secured to the interior surface of the housing walls and inflow and outflow means communicating with the interior chamber of the housing for permitting the free circulation of an insulating, dielectric medium to and from said chamber.
In U.S. Pat. No. 4,079,217, there is described an apparatus for improving the life of metallic bellows used in a hermetically sealed device having a movable element therein such as in vacuum relays and circuit breakers. The convolutions of the metal bellows are filled by a silicone dielectric gel for an axial length including several such convolutions adjacent the movable end of the bellows, thereby allegedly damping axial mechanical vibrations and preventing excessive stress build-up in the bellows portions adjacent the moveable end.
In U.S. Pat. No. 4,127,776, there is described a conventional x-ray tube and shield assembly for use in dental radiography. The conventional assembly has the x-ray tube affixed within an open-ended cylindrical shield such that the focal point of the tube is centered with respect to a small opening provided in the shield. Positioning of this tube-shield assembly within an x-ray generator is accomplished by trial and error means. The improvement includes an interiorly threaded tubular member extending outwardly from the shield and concentrically around the small opening of the shield. The threaded tubular member is received by a filter element which is disposed within an eye-port opening of an x-ray generator. Since a close dimensional clearance is provided between the tubular member and eye-port opening, the tubular member thus automatically self-centers the x-ray tube and shield within the x-ray generator when the filter element engages the tubular member.
In U.S. Pat. No. 4,355,410, there is described an enclosed, self-contained, air-cooled industrial x-ray machine having a housing which is also a gas-to-gas heat exchanger. The cylindrical metallic housing for the x-ray tube and power transformers is machined to provide a large plurality of narrow radial grooves with intervening narrow vanes on both the inside surface and the outside surface. The outside is covered with a thin-walled cylindrical jacket to provide a plurality of longitudinal passageways. An inside tubular sleeve provides support for the x-ray tube and is adapted to fit closely inside of the inner grooves to provide a plurality of longitudinal passageways on the inner surface. The housing is closed off and sealed with end plates and the interior is filled with a selected heat-transfer and insulating gas at a selected pressure. An internal fan provides circulation of the gas over the x-ray tube and back to the inner longitudinal passageways to the fan. An outside fan circulates room air through the outer longitudinal passageways.
In U.S. Pat. No. 4,841,557, there is described an x-radiator having heat-producing components therein which are enclosed in a housing filled with an insulating fluid surrounding the components. A circulating pump is in fluid communication with the interior of the housing and has respective ports through which the fluid is circulated through the pump between the ports for aiding in dissipating heat from the components. The pump may be integrated within the housing, or attached to an exterior of the housing, with only its ports being in communication with the housing interior. The pump may be a squirrel-cage induction motor with a fluid conveying element, such as a ship's propeller, forming a unit with the rotor and being arranged in a protective housing together with the stator.
In U.S. Pat. No. 4,884,292, there is described an x-ray tube generally comprising an evacuated tube envelope fabricated primarily of metal and having first and second end walls and a cylindrical sidewall, enclosing a rotating anode with its target surface facing the second end wall. A heat transfer sleeve extends from the first end wall past the anode to receive heat from the anode and transfer it to the end wall for dispersal. A heat transfer cross plate at the end of the sleeve further encloses the anode to receive and transfer heat. The tube envelope is mounted within a cylindrical tube housing with the first end wall in contact with a finned mounting plate for dissipating heat. The surface of the tube envelope remains sufficiently cool to apply a layer of lead, whereby the tube is compact. The anode and cathode electrical feeds are through the second end wall. The electrical feeds have angled terminations with lead thereon.
In U.S. Pat. No. 5,086,449, there is described an x-ray tube in which oil is circulated through a heat exchanger to reduce its temperature. More specifically, at least one hot coolant fluid receiving aperture is defined adjacent an end of a suction tube in an upper most portion of a horn portion surrounding a cathode termination assembly. Bubbles of gas in the fluid which could be ionized by electrical fields inside the x-ray tube housing causing x-ray tube current irregularities and corresponding x-ray tube output irregularities are drawn into the suction tube aperture. A de-bubbler removes bubbles from the cooled coolant fluid before it is returned into an anode horn portion of the x-ray tube. Alternatively, the bubbles may be re-absorbed, dissolved, or homogenized by the action of the heat exchanger and pump. The coolant fluid passes through a central portion of the x-ray tube absorbing heat and back to the cathode horn portion.
In U.S. Pat. No. 5,357,555, there is described a method for operating an x-ray installation having an x-ray radiator which comprises an x-ray tube located in a housing filled with an electrically insulating liquid. The electrically insulating liquid is thereby degasified at intervals in order to prevent gases arising as a consequence of the decomposition of the electrically insulating liquid caused by the generated x-ray radiation from deteriorating the high-voltage strength of the x-ray radiator.
In U.S. Pat. No. 5,802,140, there is described an x-ray generating apparatus which is provided with a unitary vacuum enclosure having a rotating anode target and a cathode assembly for generating x-rays transmitted through an x-ray window. The cathode assembly is placed within the vacuum enclosure through an opening in the top wall thereof, and comprises a disk which completely covers this opening. The unitary vacuum enclosure and the disk form a radiation shield. For increasing a thermal capacity of the unitary vacuum enclosure and installing the x-ray generating apparatus into a gantry, it further comprises a mounting block which may be coupled to or encompass the unitary vacuum enclosure. The x-ray window is placed within the mounting block. A window adaptor may be utilized for the X-ray window installation.
In U.S. Pat. No. 6,254,272, there are described methods and apparatus for allegedly extending the life of an x-ray tube which contains an "insert" for generating x-rays. The insert is housed in a housing wherein an insulating fluid circulates around the insert in the housing to provide thermal and electrical insulation. This patent includes methods and apparatus for removing water from insulating oil. One embodiment includes a processor containing a coalescing element for removing water as a vapor from the oil. Other embodiments include methods and devices for drying the interior of the housing. Another embodiment includes a kit containing a processor having a coalescing element for removing water from the insulating oil.
In U.S. Pat. No. 6,487,273, there is described a radiographic apparatus that utilizes a single integral housing for providing an evacuated envelope for an anode and cathode assembly. The integral housing allegedly provides sufficient radiation blocking and heat transfer characteristics such that an additional external housing is not required. The integral housing is air cooled, and thus does not utilize any coolant. In addition, the integral housing is insulated with a potting material, which electrically insulates the integral housing and its components, and also limits the amount of noise emitted from the housing during operation. In an alternative embodiment, enhanced thermal and electrically insulating properties are allegedly achieved through the use of a potting material disposed in selected areas of the tube interior. The potting material cooperates with optimized airflow through the tube assembly to effectively and continuously remove heat there-from.
In U.S. Pat. No. 6,494,618, there are described devices for improved radiation attenuation in devices which generate x-ray radiation. A high voltage receptacle is disclosed, the receptacle being adapted to accommodate a high voltage connector to supply power to an x-ray tube and being formed of a mixture of a dielectric material and an x-ray attenuating material, such as an x-ray attenuating metal compound. X-ray radiation impinging upon the high voltage receptacle that would otherwise pass through the unshielded receptacle is absorbed or scattered by the x-ray attenuating material without the need for additional x-ray shielding. Also disclosed is an x-ray housing assembly including an x-ray housing adapted to contain an x-ray tube, and a high voltage receptacle, wherein the high-voltage receptacle and optionally a portion of the x-ray housing is formed of a mixture of a dielectric material and an x-ray attenuating material.
In Printed Patent Application Number US2002/0020547 A1, there is described a high-voltage generator which is proportioned so as to realize a particularly low weight in combination with a high output power and is suitable notably for use in rotating x-ray systems such as computed tomography apparatus. To this end, the high-voltage generator is provided with a hybrid insulation which is formed as far as possible by high resistance foam and an insulating liquid. The foam is shaped and arranged in such a manner that there are formed channels through which the insulating liquid can flow in areas requiring a discharge of heat or an electric strength stronger than can be ensured by the high-resistance foam alone.
In Printed Patent Application Number US2002/0196905 A1, the useful life of x-ray tubes is allegedly extended by filtering metal particles and other decomposition products out of the coolant fluid by filter means permanently included in the closed loop cooling fluid circuit which also includes pump means and heat exchange means.
In Printed Patent Application Number US2005/0232395 A1, there is described a dielectric connector for use in high voltage devices, including x-ray tubes. The connector comprises a dielectric material and is pre-formed before attachment to the x-ray tube. Pre-formation of the connector creates a first cavity portion therein that conforms in shape to a corresponding segment of the tube surface. A second cavity portion is also defined for receiving a high voltage receptacle. Upon attachment to the tube, the first cavity portion receives the corresponding tube segment. The high voltage receptacle is received into the second cavity portion and electrically connects with a receptacle defined on the tube surface. The receptacle enables a high voltage signal passing through the electrode to connect with either the anode or cathode disposed within the tube. Pre-formation of the connector enables connector testing and repair to occur before it is attached to the tube, saving resources, time, and cost.
As understood from the following, the present invention represents an improvement to known x-ray source assemblies in which an x-ray tube is used and located within a housing. The present invention provides for enhanced cooling of the x-ray tube and other internal parts of the assembly while also assuring an effective means of electrically coupling the x-ray tube to the necessary electrical connections through which the x-ray tube is electrically powered. Still further, the invention provides for means for detecting for undesirable arcing between the anode and cathode structures of the x-ray tube to thereby inform the assembly operator of potential harm or destruction of the assembly. Additional features of the invention will be readily discernible from the following detailed description.
It is believed that an x-ray source assembly having such desirable features and others discernible from the following teachings will represent a significant advancement in the art.

Endicott Interconnect Technologies, Inc.


A driving force transmission device includes a first rotating portion having a first facing portion, and a second rotating portion having a second facing portion. The second rotating portion has an operation range partially overlapping with that of the first facing portion. A cushioning member is provided between the first facing portion and the second facing portion. The cushioning member is deformed by being applied with a pressure. The first rotating portion and the second rotating portion transmit a driving force in a state where the cushioning member is deformed by application of the pressure.

The present invention relates to a driving force transmission device, a medium transport device, an image reading apparatus and an image forming apparatus.
A driving force transmission device is used in, for example, a drum-type photoengraving scanner. The driving force transmission device includes a toothed belt and a toothed pulley meshing with each other. Conventionally, vibration may occur at a starting position and a terminate position of meshing between the toothed belt and the toothed pulley. In order to absorb such vibration, there is proposed a toothed pulley including an inner ring portion, an outer ring portion, and vibration absorbers provided at a boundary portion between the inner ring portion and the outer ring portion (see, for example, Japanese Laid-open Patent Publication No. 62-274134).
In this regard, if the driving force transmission device is used in a scanner or the like, a change in load on the driving force transmission device may occur. In such a case, it is difficult to suppress a change in speed.

Driving force transmission device, medium transport device, image reading apparatus and image forming apparatus


Method and system for equivalence checking of a low power design are disclosed. The method includes receiving a register-transfer level (RTL) netlist representation of a circuit, receiving a power specification file for describing power requirements of the circuit, creating a low power gate netlist for representing a design implementation of the circuit using the RTL netlist and the power specification file, creating a reference low power RTL netlist for representing a design specification of the circuit using the RTL netlist and the power specification file, and performing equivalence checking between the low power gate netlist and the reference low power RTL netlist. The method further includes annotating low power information described in the power specification file into the reference low power RTL netlist, and creating low power logic in the reference low power RTL netlist.

Due to consumers' increasing expectation of longer battery life and higher performance for their mobile devices, power management has become one of the most critical design issues. However, as integrated circuits move into nanometer-scale processes, devices created using 90-nanometer and smaller process technologies can consume as much power when they are not in use as when they are being used because of increased leakage current when the devices are in the idle state. Minimizing leakage current and optimizing dynamic power consumption can lead to longer battery life and lower packaging and cooling costs. While advanced low power design methodologies, such as static and dynamic voltage/frequency scaling, power gating, and state retention, offer additional power savings, they also increase the complexity of design verification.
The complexity of design verification is exacerbated by the fact that the majority of the low power logic is introduced into the gate netlist during synthesis and physical implementation. However, a full-chip exhaustive gate-level simulation is not a practical or scalable methodology for verifying the functionalities of today's complex designs. In recent years, verification methodology utilizing formal (mathematical) proofs has gained wide popularity due to their ability to verify complex designs exhaustively. Equivalence checking (EC) is one such formal verification method which allows checking the logical equivalence of two designs at the same or different-levels of abstraction. For instance, EC can check whether an implemented full-chip gate netlist is equivalent to the reference full-chip RTL design.
FIG. 1A illustrates a conventional method for conducting equivalence checking. As shown in FIG. 1A, the method compares a design specification represented by an RTL netlist 102 to a design implementation represented by a gate netlist 106. The gate netlist 106 is created from the RTL netlist 102 by using a synthesis tool 104. In general, an EC methodology utilizes formal verification techniques such as Binary Decision Diagrams (BDDs) and Satisfiability (SAT) Solvers that operate on the Boolean gate level netlist to establish the equivalence between the RTL netlist 102 and the gate netlist 106 of a design. One drawback of this conventional methodology is that no low power logic is included in the RTL netlist and the gate netlist, and thus the EC does not verify any low power logic that may be used in the ultimate design.
FIG. 1B illustrates another conventional method for conducting equivalence checking. This method modifies the conventional method described in FIG. 1A by incorporating synthesis-tool specific low power commands 103 in the generation of the gate netlist. Thus the synthesis tool 104 uses both the RTL netlist and the synthesis-specific low power commands to generate a low power gate netlist 108. Then, the EC is conducted between the design specification represented by the RTL netlist 102 and the design implementation represented by the low power gate netlist 108. There are at least two drawbacks associated with this approach. First, the low power logic in the gate netlist cannot be verified since there is no low power logic in the original RTL netlist. Second, performing EC between RTL netlist and low power gate netlist without disabling the low power logic in gate netlist may yield incorrect verification results. The reason is that the low power logic inserted in the gate netlist by the synthesis-specific commands, such as isolation cell logic, state retention cell logic etc., is shared with the normal operation logic, and can alter the functionality of the design in the normal operating modes. In order to perform EC of normal operating mode (between RTL netlist and low power gate netlist), certain constraints need to be manually added to the low power gate netlist. These constraints tie certain signals in the design (pins or nets) to logic 0 or logic 1 value, thereby allowing disabling the low power logic. The process of applying such hard-coded (0 or 1) constraints to the gate netlist is very tedious and prone to human errors. Furthermore, applying multiple pin or net constraints on the low power gate netlist may cause certain valid functional modes to be excluded from the formal verification process, thereby resulting in incomplete verification.
Therefore, there is a need to address the issues associated with the conventional equivalence checking methodologies for a low power design.


The magnetoresistive effect element comprises a pinned magnetic layer 16 having a multilayered synthetic antiferromagnet (SAF) structure, a nonmagnetic spacer layer 18 formed on the pinned magnetic layer 16, a free magnetic layer 20 formed on the nonmagnetic spacer layer 18 and formed of a single ferromagnetic layer, a nonmagnetic spacer layer 22 formed on the free magnetic layer 20, and a pinned magnetic layer 24 of a multilayered SAF structure formed on the nonmagnetic spacer layer 22, wherein a magnetization direction of the ferromagnetic layer 16c of the pinned magnetic layer 16, which is nearest the free magnetic layer 20, and a magnetization direction of the ferromagnetic layer 24a of the pinned magnetic layer 24, which is nearest the free magnetic layer 20, are opposite to each other.

The present invention relates to a magnetoresistive effect element and a magnetic memory device, more specifically, a magnetoresistive effect element using spin transfer torque switching (spin transfer magnetization switching) mechanism, and a magnetic memory device using the magnetoresistive effect element.
Recently, as a rewritable non-volatile memory, a magnetic random access memory (hereinafter called an MRAM) including magnetoresistive effect elements arranged in a matrix is noted. The MRAM memorizes information by using combinations of magnetization directions of two magnetic layers and reads memorized information by detecting resistance changes (i.e., current changes or voltage changes) between when magnetization directions of the magnetic layers are parallel with each other and when magnetization directions of the magnetic layers are anti-parallel with each other.
As the magnetoresistive effect element forming the MRAM, a giant magnetoresistive (hereinafter called a GMR) element and a tunneling magnetoresistive (hereinafter called a TMR) element are being proposed. Among them, the TMR element which can have large resistance changes is noted as a magnetoresistive effect element to be used in the MRAM.
The TMR element includes two ferromagnetic layers laid one on another with a tunnel insulating film formed therebetween and utilizes the phenomena that the tunnel current flowing between the magnetic layers via the tunnel insulating film changes depending on relationships of magnetization directions of the two ferromagnetic layers. That is, the TMR element has low element resistance when the magnetization directions of the two ferromagnetic layers are parallel with each other and has high element resistance when the magnetization directions are anti-parallel with each other. These two states are related to data "0" and data "1" to thereby use the TMR element as a memory device.
The MRAM using the TMR element includes two signal lines (e.g., a bit line and a write word line) normally crossing each other, which are provided respectively above and below the TMR element (see, e.g., Japanese published unexamined patent application No. Hei 11-317071 (1999) (Patent Reference 1)). In reading data from the TMR element, a change of the element resistance is read to judge whether the data memorized in the TMR element is "0" or "1". On the other hand, generally in writing data into the TMR element, current is flowed in the signal lines, and a synthetic magnetic field of magnetic fields generated by the signal lines is applied to the TMR element, whereby the magnetization direction of one magnetic layer (free magnetic layer) is changed corresponding to the applied magnetic field (current magnetic field write method).
However, in the current magnetic field write method, the demagnetizing field of the free magnetic layer is increased as the size of the TMR element is reduced so as to satisfy larger capacities exceeding, e.g., gigabits (Gbits), and the magnetization reversing magnetic field Hc of the free magnetic layer is accordingly increased. Accordingly, when the write current is small, defective write takes place. Thus, as the integration increases, the write current is increased, and electric power consumption is increased. Kohjiro Yagami et al., "Research Trend in Spin Transfer Magnetization Switching", Journal of the Magnetics Society of Japan, Vol. 28, No. 9, 2004, pp. 937-948 (Non-Patent Reference 1) anticipates that when the memory cell size is reduced to about 100 nm so as to satisfy large capacities exceeding gigabits, the conventional current magnetic filed write method drastically increases the write current, and actually the write will be difficult.
The MRAM with selective transistors connected to must include write word lines in addition to the bit lines and the word lines, which complicates the device structure and the fabrication process.
In such background, recently as the magnetoresistive effect element forming a large-capacity MRAM, the spin transfer torque switching (STS) element is noted (refer to, e.g., Non-Patent Reference 1). The spin transfer torque switching element is a magnetoresistive effect element including an insulation layer or a non-magnetic conductor layer between two ferromagnetic layers, as do the GMR element and TMR element.
In the spin transfer torque switching element, when current is flowed from the free magnetic layer to the pinned magnetic layer perpendicularly to the film surface, spin-polarized conduction electrons flow from the pinned magnetic layer to the free magnetic layer to make the exchange interaction with the electrons of the free magnetic layer. Resultantly, torques are generated between the electrons, and when the torques are sufficiently large, the magnetic moment of the free magnetic layer is switched from anti-parallel to parallel. On the other hand, when the current is applied oppositely, the conduction electrons flow from the free magnetic layer to the pinned magnetic layer. Parts of the conduction electrons are reflected against the interface between the nonmagnetic layer (insulation layer or nonmagnetic conduction layer) and the pinned magnetic layer, and the spins are switched. The conduction electrons reflected against the interface flow from the nonmagnetic layer again into the free magnetic layer and make the exchange interaction with the electrons of the free magnetic layer. Resultantly, torques are generated between the electrons, and when the torques are sufficiently large, the magnetic moment of the free magnetic layer is switched from parallel to anti-parallel. This switch from parallel to anti-parallel has poor spin transfer efficiency in comparison with the switch from anti-parallel to parallel and requires large current for the switch of the magnetization. As described above, the spin transfer torque switching element induces the magnetization switch of the free magnetic layer by the current control (application direction and application current value) alone to thereby rewrite the memory state.
The spin transfer torque switching element, which has the switching current decreased due to the volume decreasing effect even with the decrease of the element size and the resultant magnetization reversing magnetic field Hc, is much more advantageous to the elements of the current magnetic field write method in the capacity increase and electric power consumption decrease. The spin transfer torque switching element requires no write word lines, which permits the device structure and the fabrication process to be simplified. That is, the MRAM using the spin transfer torque switching elements can use the same device structure as DRAM, which permits the fabrication process to be simplified and the fabrication cost to be accordingly decreased.
However, to realize an MRAM of a large capacity exceeding gigabits, various problems, as of decreasing the write current, etc., are present. Non-Patent Reference 1 describes a cell area of ˜(0.1 μm)2, a RA (element resistance R×cell area A) of ˜tens Ωμm2, resistance change percentage above 30%, a write current (magnetization reversing current) Ic below 0.1 mA, etc. tentatively calculated as the target values for realizing such large-capacity MRAM.
A 0.1 mA write current Ic is equivalent to 1×106 A/cm2 in the critical current density Jc. However, the critical current density Jc so far reported on the research level is 0.5×107˜107 A/cm2 (refer to Non-Patent References 1 and G. D. Fuchs, "Spin-transfer effects in nanoscale magnetic tunnel junctions", Applied Physics Letters, Vol. 85, No. 7, 2004, pp. 1205-1207 (Non-Patent Reference 2)). Accordingly, to realize a large-capacity MRAM, first, it is necessary to further decrease the write current.
As described above, in the conventional spin transfer torque switching element, the switch from parallel to anti-parallel depending on conduction electrons reflected against the interface between the ferromagnetic layer and the nonmagnetic layer is inefficient in comparison with the switch from anti-parallel to parallel and requires larger current. Accordingly, the resistance-current hysteresis characteristic of the spin transfer torque switching element has poor symmetry.
In the conventional spin transfer torque switching element, the free magnetic layer and the pinned magnetic layer are magnetically coupled due to leaking magnetic field from the pinned magnetic layer, and the resistance-current hysteresis characteristic has shifted.
In the large-capacity MRAM, to make the memory operation stable, high output changes are required. To this end, the spin transfer torque switching element is required to have large resistance change percentage.
The related arts are also disclosed in, e.g., Japanese published unexamined patent application No. 2004-158766 (Patent Reference 2) and Japanese published unexamined patent application No. 2002-359412 (Patent Reference 3).

Magnetoresistive effect element and magnetic memory device


A bus bridge circuit having a memory port integrated therewith for upstream memory access independent of the activity on the primary bus connected to the bridge circuit. In a preferred embodiment, the present invention adds a memory port to a PCI bridge circuit usable for upstream data transfers to an attached cache memory subsystem. The memory port of the present invention is preferably 64 bits wide to permit high speed data access to the shared cache memory subsystem. An alternative embodiment of the present invention implements a 128 bit wide data path to an attached high speed cached memory subsystem. The memory port of the present invention utilizes FIFO devices to isolate the memory port transactions from the secondary bus transactions. This FIFO design of the memory port allows bursting of high speed transfers to the shared memory, independent of activity on the primary bus, while minimizing the performance impact on the secondary bus.

1. Field of the Invention
The invention relates to the field of bus bridge integrated circuits and in particular to a bus bridge circuit design which includes an integrated memory port for simultaneous memory access and bus data exchange.
2. Related Patents
This patent is related to commonly assigned, co-pending, United States patent application (08/673,654) entitled SCALABLE HIERARCHICAL MEMORY STRUCTURE FOR HIGH DATA BANDWIDTH RAID APPLICATIONS filed Jun. 20, 1996 which is hereby incorporated by reference. This patent is also related to commonly assigned, co-pending, U.S. Pat. No. 5,634,033, filed Dec. 16, 1994 by Stewart et al., entitled (as amended) DISK ARRAY STORAGE SYSTEM ARCHITECTURE FOR PARITY OPERATIONS SIMULTANEOUS WITH OTHER DATA OPERATIONS, which is hereby incorporated by reference.
3. Discussion of Related Art
Bridge circuits are known to connect a first electronic bus to a second electronic bus. The bridge circuit serves to adapt the signals of the two busses to enable data exchange between the two bus signal standards. Frequently, bridge circuits are used to convert between different signaling standards defined for the first and second busses. Another common application of bus bridge circuits, as discussed in related application (95-09619020-128), hereby incorporated by reference, is to connect multiple, often hierarchical busses to common devices or memory subsystems.
In RAID storage subsystem control applications, for example, a Peripheral Computer Interconnect (PCI) bus is used to connect various peripheral I/O devices through a bridge circuit to a centralized PCI bus for the overall control of all I/O devices in the subsystems as well as the cache memory subsystem.
It is common in the prior art that a bridge circuit is used to connect the various devices in the RAID subsystem both for purposes of I/O control and data exchange and for direct access to the cache memory subsystem. In such a centralized, hierarchical bus structure, the bus connected to the bridge circuit in common with other connections of other bridge circuits is referred to herein as the primary side or primary bus. The bus connected to the bridge circuit on the opposite side of the bridge relative to the primary side is referred to herein as the secondary side or secondary bus. Data flowing through the bridge circuit from the primary side to the secondary side is referred to herein as downstream data or downstream flow. Data flowing through the bridge circuit from the secondary side to the primary side is referred to herein as upstream data or upstream flow.
It is a problem in such bridge circuit designs that if the secondary bus requires a transaction be passed through the bridge circuit to access a shared resource on the primary bus, and the primary bus is unavailable due to other access unrelated to the shared resource, the request of the secondary bus is delayed until the primary bus is again available. For example, if a storage device connected to one of several secondary (PCI) busses is desirous of exchanging data with a centralized high speed cache memory subsystem connected to the primary bus, then the data exchange may be delayed if other data transfers are occupying the primary (PCI) bus, despite the potential availability of the centralized high speed cache memory subsystem.
Typical hierarchical PCI bus systems within RAID subsystem controller designs exhibit the problems inherent in the prior art. When a secondary PCI bus requires access to the shared cache memory subsystem via the primary PCI bus, the cache memory access will be delayed while the primary PCI bus is in use for normal system control functions by the main processor of the RAID controller. Such delays in performing data exchange requests can negatively impact the overall performance of the RAID storage subsystem in processing I/O requests.
It is evident from the above discussion that a need exists for an improved bus bridge circuit design which reduces the potential for such delays in processing of I/O requests.

Inter-bus bridge circuit with integrated memory port


Disclosed are a method and an apparatus for reconstructing three-dimensional (3D) clothing using captured image information on clothing, which capture image information on clothing put on a mannequin, generate a temporary model using the captured image information, and generate a final clothing model using the temporary model.

1. Field of the Invention
Embodiments of the present invention relate to an apparatus and method of reconstructing a three-dimensional (3D) clothing model, and more particularly, to an apparatus and method of reconstructing a 3D clothing model which reconstruct an appearance of a 3D model of real clothing and transform into an appropriate form for a simulation using image information on the real clothing.
2. Description of the Related Art
Recent advancement and spread of sensors to measure depth information on images facilitate reconstruction of various shapes of objects into three-dimensional (3D) forms. Here, the objects reconstructed into the 3D forms are provided to users via visualization or simulation through devices and are applicable to various fields.
As a representative application, there is a user-oriented clothing service which provides users with a clothing experience service using virtual 3D clothing. The user-oriented clothing service, which uses virtual 3D clothing, provides various services of enabling a user to try on clothes on-line or customizing clothes.
Here, the user-oriented clothing service provides a cloth simulation controlling movements of virtual 3D clothing corresponding to user movements. The cloth simulation enables a user to see wearing clothing without directly trying on the clothing, and thus mistakes by the user in purchasing clothes may be minimized.
However, the user-oriented clothing service has no method for continuously providing virtual 3D clothes for user experience. In detail, the user-oriented clothing service uses a method of creating clothes using computer graphics authoring tools, such as Autodesk Maya, and a method of making virtual clothing by constructing a virtual 3D model using patterns of real clothing. Here, the method using the authoring tools is a classical method used for making costumes of game or movie characters and involves difficulty in digitalizing real clothing. Also, the method of making the virtual clothing, as in making real clothing, generates virtual patterns based on the patterns, integrates the virtual patterns to produce a 3D model and attaches the 3D model to a virtual character, thereby producing virtual clothing.
Here, clothing with pleats, for example, a female dress, involves a draping process to maintain a smooth shape, which is tricky to automate because a fashion sense is required. Moreover, virtual clothing production has different working environments from real clothing production, making it difficult for a designer to do the job.
Another problem of the method using the pattern occurs when there is no pattern, for example, since clothing is made before a system is applied or clothing is imported. When there is no pattern, pattern data is extracted by scanning clothing put on a mannequin using a 3D scanner so as to obtain a pattern, and digital clothing is made using the extracted pattern. This method, however, needs manual processes by experts for a long time and thus is inappropriate for making clothes.
Manual processes include separating a clothing area from shape data of a 3D mesh configuration of the 3D scanned clothing and lowering complexity of a mesh, removing a hole generated in scanning, generating texture information on the clothing in a form, or the like. To extract a pattern from shape data, a pattern extracting process by an expert through a graphic user interface (GUI) is necessary. To apply the generated form to a virtual clothing experience, parameter setting considering properties of the clothing, such as stretchiness and weightiness of the clothing, and combined parts with an avatar need to be defined. That is, time and a labor-intensive process are necessary to convert current real clothing into clothing for digital experience through 3D scanning.
Accordingly, there is presented a method of automating a digitizing process of real clothing for a virtual clothing fitting service for manufacturers having data on clothing, such as patterns, and distributors having no clothing data, thereby facilitating making digital clothing of the real clothing for experience without expert knowledge.

Apparatus and method of reconstructing 3D clothing model

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


An oscillator circuit (100, 200, 300, 10, 11) comprising a resonator (105) connected serially with a series to series feedback amplifier (110, 92), in which the series to series amplifier comprises a feedback network (210, 91) which has an impedance value which is below a certain first predefined limit and a phase value which increases with the operational frequency of the oscillator circuit with a rate which is above a second predefined limit. In one embodiment, the impedance value of the feedback network (210, 91) also varies with the operational frequency of the oscillator circuit, but is always below said first predefined value within the operational frequency of the oscillator circuit.

A local oscillator, LO, for use as a signal source is an important building block in many communications systems and radar systems. In an LO, a low phase noise is often needed in order to achieve a high performance of the overall system in which the LO is comprised.
Examples of oscillator technologies that are often used in LOs are Radio Frequency Integrated Circuits (RFIC) oscillators, and Monolithic Microwave integrated Circuits (MMIC) oscillators. For both RFIC and MMIC oscillators, their phase noise performance is limited mainly by the quality factor Q of an on-chip resonator which is comprised in the oscillator. The resonator will often comprise a varactor or a fixed capacitor, as well as an inductor.
Attempts have been made to address the issue of phase noise in LOs. These attempts have mainly concentrated on improving the Q-factor of the resonator's inductor. However, at higher frequencies, for example at frequencies above 20 GHz, these attempts have not been as successful as would have been desired.
Document EP 1 926 207 A1 discloses an oscillator circuit which comprises a fine tuning network, a coarse tuning network and a dynamically tuned dual coupled resonator network.


A solar cell comprising a plurality of photovoltaic elements electrically serially connected with each other on a common conductive substrate, each of said photovoltaic elements comprising a first insulating layer, a first electrode layer, a semiconductor layer, and a second electrode layer laminated in this order on the common conductive substrate, and each pair of the adjacent photovoltaic elements being electrically serially connected by electrically connecting the first electrode layer of one adjacent photovoltaic element to the second electrode layer of the other adjacent photovoltaic element, characterized in that a second insulating layer is disposed between said first insulating layer and the end portion of said first electrode layer and a second insulating is disposed between the region of said first electrode layer serving to perform said serial electrical connection and said first insulating layer.

In recent years, heating of the earth because of the so-called greenhouse effect due to an increase of atmospheric CO.sub.2 has been predicted. Thus, there is an increased demand for a means of power generation capable of providing clean energy without causing CO.sub.2 buildup. Nuclear power generation has been considered to be advantageous in view of not causing CO.sub.2 buildup. However, possible problems concerning leakage of injurious radioactive materials from the nuclear power generation system, treatment of radioactive wastes, and the like have not yet been completely eliminated. Thus, nuclear power generation cannot yet be a sufficiently safe power source of supplying clean energy. In this respect, public attention has been recently focused on power generation by solar cells as it is safe and supplies clean energy without those problems as above mentioned. As for solar cells, there are great expectations since they are safe and easily handled.
As for solar cells, a number of proposals have already been made. Among the proposed solar cells, amorphous silicon or copper indium selenide solar cells have been spotlighted and various studies have been made thereon since they can be easily designed to be of a large area and they can be provided at a relatively reduced production cost.
In general, it is required for solar cells to excel in weather resistance, shock resistance, and flexibility. In order to meet these requirements, a metal (conductive) substrate is often used as their substrate.
In order to obtain a desired electromotive force from a solar cell, generally a plurality of photovoltaic elements respectively comprising a photovoltaic layer are disposed on a conductive substrate made of stainless steel, etc. and connected to photovoltaic elements by means of wiring.
FIG. 4 is a schematic diagram of a known solar cell module comprising a plurality of photovoltaic elements serially connected with each other by means of wiring materials. In FIG. 4, reference numeral 400 indicates a conductive substrate, reference numeral 401 a lower electrode, reference numeral 402 a semiconductor layer (photovoltaic layer), reference numeral 403 an upper electrode, reference numeral 404 a collecting electrode, and reference numeral 405 a wiring material for electrically connecting adjacent photovoltaic elements.
Japanese patent publications Sho. 58-21827 and Sho. 58-54513 propose a method of integrating a plurality of solar cell elements on a common insulating substrate by means of masked evaporation or the like. As a modification of said method, there is known a method in which an insulating layer is applied onto the surface of a conductive substrate, metal electrode patterns are successively formed by means of masked evaporation or the like, and the metal electrode of one photovoltaic element is connected to the transparent electrode of the adjacent photovoltaic element (subcell) disposed on the same substrate. FIG. 5 is a schematic diagram of a known solar cell module comprising a plurality of photovoltaic elements integrated on a common substrate by means of masked evaporation. FIG. 5(a) is a plan view of said solar cell module, and FIG. 5(b) is a schematic cross-section view taken along the line 505-506 of the solar cell module shown in FIG. 5(a). In FIG. 5, reference numeral 500 indicates a conductive substrate, reference numeral 501 an insulating layer, reference number 502 a lower electrode, reference number 503 a semiconductor layer (photovoltaic layer), and reference numeral 504 a transparent electrode as an upper electrode.
As for the method of connecting a plurality of photovoltaic elements by means of serial wiring, there are problems in that the connecting step is time consuming and the product obtained thereby becomes unavoidably costly.
Likewise, as for the method of serially connecting a plurality of photovoltaic elements on a common substrate by means of the masked evaporation, there are problems in that it is difficult to precisely align the required masks, particularly in the case of producing large area modules. In addition to this, a variety of masks are required in order to comply with a desired power capacity and/or a desired shape; and as a result, the product obtained thereby becomes unavoidably costly.
As above described, there is known a solar cell module formed by integrating a plurality of photovoltaic elements respectively disposed on an insulating substrate. There has been proposed a method of performing integration of the photovoltaic elements in this case by use of a laser beam.
However, in the case where the laser beam processing is employed in order to integrate a plurality of photovoltaic elements respectively provided with a common conductive substrate such as a metal, a laser beam is irradiated on a conductive electrode (for example, a metal electrode) formed on the insulating layer disposed on the conductive substrate to thereby pattern said conductive electrode. In this case, portions of the conductive substrate which are situated under portions of the metal electrode to be removed through patterning are often fused to cause short-circuits between the metal electrode and the conductive substrate. In addition, because of this, it becomes difficult to connect a plurality of photovoltaic elements (subcells) through serial connection on a common conductive substrate.
Similarly, in the case of electrically connecting the upper electrode to the lower electrode by means of a laser beam, short-circuits are often caused between the conductive substrate, the upper electrode, and the lower electrode.
Thus, there are a number of problems required to be solved in the case of employing laser beam processing for the production of a solar cell using a conductive substrate.
In order to avoid occurrence of the foregoing short-circuits with respect to the conductive substrate in the laser beam processing, there is a method in which the insulating layer is so thickened as to prevent the laser beam from impinging the conductive substrate. However, it is extremely difficult to form a thick film on a large area surface of flexible substrate in a uniform and flat state without causing film peeling. And it is not advisable to apply a thick film comprising a rigid inorganic material on the entirety of said surface in view of the flexibility required for a solar cell. Further in addition, in the case where the entirety of said surface is coated by such thick film, there is also a problem that cracks are apt to occur and when those cracks occur, short-circuits are unavoidably caused between the metal electrode and the conductive substrate.
In view of the above, there has not been up to now decisive means by which the foregoing problems in the prior art can be effectively solved.


A clock multiplier includes a phase-locked loop (PLL), a bias generator, a counter, a selection circuit, a flip-flop, a phase comparator, a delay controller and a variable delay circuit. The variable delay circuit, which is biased by a delay cell bias signal, delays a reference signal by a first delay time and by a second time that is longer than the first delay time, and generates a first feedback signal corresponding to the first delay time, and a second feedback signal corresponding to the second delay time. Therefore, a clock multiplier may reduce the size of a delay cell and may be designed to be insensitive to changes in environmental conditions, such as a process, a voltage, a temperature, and so on.

1. Field of the Invention
The present invention relates to clock multipliers, and more particularly to clock multipliers using a filter bias of a phase-locked loop to reduce the size of a delay cell, and methods of multiplying a clock.
2. Description of the Related Art
The present invention relates generally to clock multipliers, and more specifically to clock multipliers that may be useful in a design of a low-power voltage circuit.
A clock multiplier multiplies a frequency of an input clock to generate an output clock having a frequency higher than that of an input clock, and then provides the output clock of the clock multiplier to one or more inner circuits of a semiconductor device.
One example embodiment of a clock multiplier using digital complementary metal-oxide semiconductor (CMOS) standard cells is proposed by Michel Combes et, al. in the paper, "A portable clock multiplier generator using digital CMOS standard cells," IEEE Journal of Solid-State Circuits, Vol. 31, No. 7, July 1996.
From an aspect of very large-scale integration (VLSI) designs, as operating frequencies in semiconductor devices have been increasing, it has become an important issue to design a clock generator that is insensitive to changes in environmental conditions.

Clock multipliers using filter bias of a phase-locked loop and methods of multiplying a clock


A method for compiling thermographic data including obtaining data indicative of a monotonically changing characteristic of a specimen, sequencing the data or a surrogate of the data into a plurality of groups, categorizing, within each group, the frequency distribution of an attribute of the data or an attribute of said surrogate data, and compiling, from one or more groups, a collection of two or more of the frequency distributions.

Active thermography is used to nondestructively evaluate samples for sub-surface defects. It is effective for uncovering internal bond discontinuities, delaminations, voids, inclusions, and other structural defects that are not detectable by visual inspection of the sample. Generally, active thermography involves heating or cooling the sample to create a difference between the sample temperature and the ambient temperature and then observing the infrared thermal signature that emanates from the sample as its temperature returns to ambient temperature. An infrared camera is used because it is capable of detecting any anomalies in the cooling behavior, which would be caused by sub-surface defects blocking the diffusion of heat from the sample surface to the sample's interior. More particularly, these defects cause the surface immediately above the defect to cool at a different rate that the surrounding defect-free areas.
As the sample cools, the infrared camera monitors and records an image time sequence indicating the surface temperature, thereby creating a record of the changes in the surface temperature over time. It is the current practice to use a human operator to view the record of these changes and to look for "hot spots" in the image record. In many instances, this analysis is purely visual (i.e. the human inspector views a display of the image output on a monitor and identifies regions that appear "hot" compared to surrounding areas. More sophisticated methods attempt to use numerical processing of the data by generating contrast curves relative to a reference specimen of known quality and composition (a so-called "gold standard"). This reference specimen, which is known to be defect free, is typically placed in the field of view of the imaging camera. In other instances, the "gold standard" is not a reference specimen at all, but rather it is an image that has been derived from a physical model. However, in general, the time history of the cooling of the sample is not viewed as a whole (i.e. a contiguous sequence), but rather as a collection of individual frames acquired from the infrared camera. These methods work adequately for large, or near surface, defects. However, as manufacturing processes and safety standards requirements place higher demands regarding smaller/more subtle defect detection, these traditional methods become less effective because the small signal levels associated with subtle defects are lost in the noise, drift, and instability that is inherent to infrared cameras. Also, visual defect identification methods tend to be subjective, and they do not readily and easily lend themselves to the automatic defect detection process. Further, it is not possible to measure the depth of the defects simply by viewing the infrared images.
There have been attempts to determine the depth of a defect via processing and analysis of the data from the infrared camera and also to automate the defect detection process. In some cases, the data from the infrared camera is transferred to a computer for processing and analysis to detect variations in the cooling behavior or to perform mathematical operations on the data to determine the depth of the sub-surface defect or other defect properties. These types of calculations, however, often require expensive low noise, high-speed digital infrared cameras. Further, the cumbersome nature of having a computer attached to the camera for conducting calculations makes the combination impractical for applications outside of a laboratory, such as field inspections.
Also, infrared data sequences of thermal decay typically used in non-destructive testing tend to be difficult to manipulate mathematically due to their low signal-to-noise ratios and large dynamic range and also require a great deal of computer processing power, memory and storage space.
One attempt at automating the defect detection process involves analyzing the contrast between each pixel in the image and a reference to generate a curve representing the amount of contrast between each pixel and the reference. The reference can be established any number of ways including using a reference pixel (from the sample image), a pixel group (from the sample image). If a pixel, or a pixel group is used, a reference point or reference area of the sample must be defined. The reference can be a defect-free area of the sample, or the mean of the entire field of view of the camera (when viewing the sample). The temperature-time history of this reference pixel or pixel group is subtracted from the time history of each pixel in the image to generate a contrast vs. time plot. Any significant temperature difference between any given pixel and the reference indicates the presence of a defect which will exhibit itself as a peak in the contrast vs. time plot. The contrast vs. time plot can be measured with respect to the time at which the peak occurs, the time at which a maximum ascending slope occurs, and/or a moment of the curve for each pixel. Other options, such as generating and displaying the contrast vs. time plot with a reference plot and checking the point at which the two plots separate, have also been applied.
Such contrast-based methods tend to have significant shortcomings, however. In addition to the data storage, memory and processing problems noted above due to the large size of the infrared image data files, contrast-based methods require the identification of a defect-free region on the sample as a reference point. This requirement is often not realistic for some samples if, for example, the size of the defect is larger than the infrared camera's field of view. In such a case, there is no defect-free area available that can act as a reference for a given region. Further, if the entire sample exhibits a defect (e.g., a large delamination running underneath the entire surface of the sample), there is no contrast between any region of the sample because the whole sample is equally or nearly equally defective.
Contrast-based methods that rely on the mean of the entire field of view as a reference have also been used, but this method assumes that the defect area in the field is small enough so that it will not appreciably influence the mean. If a defect (or group of defects) occupies a large portion of the field of view, the contrast method is ineffective because a significant portion of the mean value result is composed of data derived from defective sample points which acts to reduce any appreciable difference between the defect area and the mean when the contrast value is calculated.
Regardless of the specific reference value used in detecting defects, the results obtained using contrast-based methods depend strongly on the choice of reference region on the sample. More particularly, the results obtained in contrast-based methods can be altered by simply changing the location of the reference region.
Further, in evaluating the results from both the contrast-based methods and the data obtained directly from the infrared camera, identifying the time at which a maximum peak slope occurs (indicating the presence of a defect) is often difficult because the signals are often inherently noisy, thus the contrast based method must be capable of discriminating between pixels associated with defects and pixels associated with noise. Although the peak slope (of the temperature vs. time relationship) is a useful indicator of defect depth, the peak slope inherently must occur earlier than the peak contrast and may be obscured by the heating event, or by lingering heat from the equipment after flash heating the sample. The peak slope may also be obscured if the instantaneous temperature of the sample exceeds the camera's peak temperature detection capabilities, causing an initial, highly nonlinear response from the camera due to camera saturation.
A common approach to improving the signal-to-noise content of thermographic data is to replace the amplitude of each pixel with the mean or median value of that pixel and its surrounding nearest neighboring pixels as defined by an N×N matrix, where N is a selected integer. This approach, however, sacrifices spatial resolution to lessen temporal noise. Another approach for reducing temporal noise is to average data over a selected number of consecutive frames, but this approach sacrifices temporal precision. As a result, known techniques for reducing temporal and spatial noise necessarily degrade temporal and/or spatial resolution and precision.
Another technique which may be used in attempt to filter noise from thermographic data is to simply fit the raw temperature-time history of each data point of the sample, with a polynomial or a set of orthogonal functions. However, when one understands the underlying physical process of thermal imaging as well as the nuances of using all but the most expensive thermal imaging cameras, these approaches prove unsuccessful for several reasons:
A. Thermographic data (when generated using a pulse of energy to heat the sample), presents an extremely large dynamic range thereby making it extremely difficult to accurately fit both the data occurring early in the sampling process (large amplitude) and later in the sampling process (small amplitude). Specifically, the very steep, early post-excitation behavior of the temperature-time history of a point requires a high order polynomial or other similar expansion to accurately model the data. However, such high order terms introduce undesirable errors (such as oscillations) in the polynomial fit later in the time-temperature sequence when in fact the data is not oscillatory but rather stable.
B. The early, high amplitude response of the sample's thermal signature, is often outside, or near the calibration limit of the infrared camera. As a result, the signal generated during this portion of the imaging exercise is often highly non-linear.
C. The early, high amplitude, data points dominate the fit and worsen the fit for later occurring data points.
The difference between the thermal response of an intact point (i.e. a defect free portion of a sample) and the thermal response of a sub-surface defects is often very small (e.g. on the order of the temperal noise) and accordingly very difficult to identify.
Thermographic Fingerprinting
In many manufacturing applications, determining whether a component is within specifications is critical. In many such applications, the particular details of the defect are not critical and a simple "pass/no pass" test is sufficient. A defective component may fail to be "in spec" not because of a discreet defect, but rather because of distributed defects caused by process variables or problems due to tooling or material composition. In the vast majority of manufacturing applications, it is highly desirous to automate inspections from both a cost standpoint and an accuracy standpoint. Many quality assurance schemes accomplish the "pass/no pass" test by comparing a production specimen to that of a defect free specimen, also known as a "gold standard" specimen.
When using "gold standard" testing in the context of thermal imaging, a defect free specimen is created or chosen having internal features, which meet all manufacturing specifications (such as depth and size of apertures or bonds and joints of known acceptable quality, etc.). Once a "gold standard" specimen is selected, its thermal emission pattern is captured and stored. Thereafter the thermal data from the "gold standard" is compared to the thermal emission data associated with the production specimen. If the thermal emission patterns of the two specimens deviate from one another more than a predetermined amount, the production specimen is deemed defective. This comparison between the "gold standard" and the production specimen can be conducted by a human operator, or it can be carried out automatically using various software routines that compare the thermal emission data from the two specimens. Although the advantages associated with automated inspection are obvious, there are various challenges posed by automated inspection of thermal images. For example, most software algorithms used to compare the thermal image of the "gold standard" against the thermal image of a production specimen require pixel-to-pixel registration between the two data groups created from the thermal emission data of the two specimens. Thus, these software routines will render inaccurate results if the orientation (rotation or translation) of the production image differs from that of the "gold standard" image. Additionally, many known software algorithms employ temperature based schemes which makes them highly sensitive to the camera angle of the thermal imaging camera and the amount of heat energy used to thermally stimulate the samples.
At this time there are essentially two approaches used in employing pulsed thermography in non-destructive testing applications. The first approach is to construct thermographic images wherein each image represents particular time frame in the cooling sequence. These time frames are analyzed in an attempt to identify points or regions where anomalous local contrast exists. The images are typically constructed from image data that has undergone of one or more preprocessing operations. Although this approach is effective in some applications, it has several notable drawbacks. Three of which are as follows:                1. You can only examine discrete "slices" in each image and, by definition, a single "slice" does not describe the state of the entire sample.        2. The success of the method is based on the presence of localized defects that fall within the field of view of the imaging apparatus. Accordingly, this approach does not lend itself to discriminate between a sample that is "all good" or "all bad" even though it is often highly desirable to be able to discriminate in this way.        3. Comparison of two samples can only be accomplished by image-to-image comparison of each image "slice" in the corresponding data sequence of each sample. This approach is not only cumbersome but lends itself to inaccuracies (if the images contain temperature or temperature contrast data). These inaccuracies arise primarily because it is very difficult to establish repeatable temperatures from shot-to-shot (inasmuch as temperature is highly dependent on ambient conditions, heat energy input, energy distribution and other factors).
The second pulsed thermography approach is one where a sample is imaged and the imaged data is analyzed on a pixel-by-pixel basis in order to measure some physical quantity (such as sample wall thickness, defect depth, thermal diffusivity, or the like). This approach reduces the sequence of images into a single image representing thickness, depth, diffusivity or the like, a based on a time characteristic measured in each pixel's time history. Although this type of information is very useful in terms of physical dimensions or determining whether or not there are defects in the sample, it is entirely possible that a sample could be defect-free and yet still be sufficiently deficient to warrant rejection. For example, a specimen could be compositionally different (e.g. a mixture in the fabrication process was incorrect), or it could contain an excessive amount of porosity (pores that are too small to be resolved thermally, but that effect the density of the sample). Such samples could be easily "passed" using a pixel-by-pixel analysis approach.
Unlike the two above-referenced approaches, the approach disclosed herein allows visualization of the entire time sequence of the entire sample. Even if no "defect" or dimensional change occurs, subtle changes in the sample (or sample composition) will cause corresponding changes in the shape of the "fingerprint" image. The changes that occur may be too subtle to be detected by prior art methods but, using "fingerprint" the method of the present invention, they are made apparent when directly correlated against a gold standard "fingerprint."

System for generating thermographic images using thermographic signal reconstruction


An absorption chiller includes a heating medium supply pipe configured to supply a heating medium from a heating medium pipe to a cooling water pipe; a cooling water discharge pipe configured to discharge a cooling water from the cooling water pipe to the heating medium pipe; a control valve provided on the heating medium supply pipe and the cooling water discharge pipe, respectively; and a controller configured to cause the control valve to be opened and to cause the heating medium in the heating medium pipe to be introduced into the cooling water pipe, when a temperature detected by a cooling water temperature detector is equal to or lower than a predetermined temperature, in a wet lay-up state including a state in which a cooling water inlet shut-off valve and a cooling water outlet shut-off valve are closed and the cooling water pipe is filled with the cooling water.

Commonly, in an absorption chiller, dry lay-up in which cooling water is removed is performed to prevent damage to a device due to freezing of cooling water that is not used when the operation is stopped in winter. However, when sufficient drying cannot be performed in the dry lay-up, a large amount of time may be required for the repair work due to generation of metal rust caused by corrosion in a pipe and a water chamber.
Thus, wet lay-up, in which an in-device cooling water system is in a state of being filled with water, has been implemented (see, for example, JPH5118691A). However, in an absorption chiller disclosed in JPH05118691A, it is necessary to prevent damage to a device due to freezing in an environment in which freezing may occur, based on a state in which the wet lay-up is performed. Therefore, in the absorption chiller disclosed in JPH05118691A, when a decrease in the temperature of cooling water is detected, the heating operation is performed and the cooling water is circulated.
In the absorption chiller described in JPH05118691A, the heating operation may be performed. However, when the absorption chiller has no heating function or when there are circumstances that heating operation is not desired, freezing cannot be prevented by the heating operation.


A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

In the general field of acoustic sensor systems and in particular in the field of acoustic hydrophone systems employed in underwater surveillance systems, one known problem is that of transferring the electrical signals produced by the various sensors to a centralized processing system that exploits these signals in a combined way. However, if the system in question comprises a high number of sensors, the number of electrical signals to be transferred is also high.
For this reason, it is known to multiplex these signals in optical form and route them on a single optical fiber or at least on a small number of fibers.
In practice, if the acoustic sensors employed are electro-acoustic transducers, the implementation of a multiplexed transmission through an optical fiber generally consists in associating, with each sensor, an electro-optical transducer capable of producing a light wave of nominal wavelength λ0 modulated by the electrical detection signal produced by the acoustic sensor.
Each electro-optical transducer thus produces a modulated light wave capable of occupying a given optical bandwidth, i.e. a wavelength range, about the nominal wavelength λ0.
Below, the various multiplexed light waves are transmitted by summing, in a suitable optical fiber, all of the produced light signals while, however, taking care that each electro-optical transducer produces a nominal light wave λ0 different from the other transducers and that the wavelength range occupied by the signal that can be produced by one transducer does not overlap with the wavelength range occupied by the signal that can be produced by another transducer.
However, when the number of sensors forming the system in question is truly high, it is sometimes difficult to multiplex all of the produced optical signals into a single optical fiber. For this reason, the value of the margins separating the nominal wavelengths of the electro-optical transducers from one another must be minimized. The number of signals that can be transmitted by a given optical fiber is thus optimized.
However, to do this, it is especially important for the nominal wavelength λ0 of the modulated light wave produced by each of the transducers connected to the optical fiber to be kept as stable as possible and to depend as little as possible on temperature conditions.
The French patent application published under the reference FR 3045817 describes, in this regard, an example of an electro-optical transducer intended to convert the electrical signal produced by an electroacoustic sensor, a hydrophone in fact, into a light signal obtained by modulating the wavelength of a fiber laser, comprising a laser cavity consisting of a fiber-optic element forming a Bragg grating.
FIG. 5 of the present description illustrates the general structure of such a transducer, the structural details and operation of which are not recalled in the present description.
The general operating principle of such an electro-optical transducer is that the wavelength of the produced laser wave is modulated by making the length of the fiber-optic element 12 forming the cavity of the laser emission source vary, said fiber-optic element being kept taut (mechanical pre-tension) by securing elements 13 and 14 when it is at rest at a given ambient temperature θ.
The variation in length of the fiber-optic element 12 is itself obtained by means of a piezoelectric actuator 18 arranged so as to act on the mechanical tension applied to the fiber-optic element 12 depending on the electrical voltage that is applied thereto, which electrical voltage in this case comes from the electro-acoustic sensor with which the actuator is associated.
The variation in the mechanical tension applied to the fiber causes in a known manner a variation in its length L and thus a variation in the wavelength of the light wave produced.
In the illustration in FIG. 5, the piezoelectric actuator 18 consists of four bars made of piezoelectric material that are placed around the fiber-optic element 12, each bar being fastened via one end to one of the securing elements 13 or 14 and via its other end to a holding element 16 placed in a central position. All thereof are placed in a casing consisting of a cylindrical body 51 closed by two end elements 52, the holding element 16 being securely fastened to the cylindrical body 51.
As may be seen in FIG. 5, the main advantages of such a transducer are the simplicity of its structure, its compactness and its ease of implementation. Specifically, by changing length under the action of an electrical voltage, the piezoelectric actuator 18 acts directly on the mechanical tension applied to the segment of optical fiber 12.
Moreover, advantageously, because the light wave is generated by means of a fiber laser, this type of transducer may easily be connected in series in a fiber-optic link conveying, in multiplexed form, the light wave signals produced by a plurality of sensors.
In contrast, this type of transducer has the drawback of being sensitive to variations in ambient temperature. Specifically, under the effect of variations in temperature, an optical fiber sees its refractive index and, to a lesser extent, its length, vary.
Thus, when ambient temperature varies, the wavelength of the fiber laser varies under the combined effect of the variation in refractive index n of the segment of fiber 12 from which it is formed and in the length of the same segment. These variations themselves cause a variation in the nominal wavelength λ0, this having the disadvantageous effect of needlessly broadening the wavelength range capable of being occupied by the signal produced by a transducer.
Therefore, in the prior art, although advantageous in terms of ease of implementation, the use of electro-optical transducers comprising a laser source consisting of a fiber laser, for example a transducer of the type described in the aforementioned patent application, has the effect of limiting the number of transducers that can be connected in series to a given optical fiber without running the risk of degradation of the transmitted signals as a result of variations in temperature.
In such a context, if it is desired to optimize the number of electro-optical transducers of this type able to be multiplexed in series through a given optical fiber, it is necessary to find a solution allowing the effects of the variations in ambient temperature on the wavelength of the light wave produced by such a transducer to be limited or even compensated for completely.

Temperature-compensating device and electro optic transponder implementing such a device


An input dataset comprising a plurality of input items is transformed into a smaller output dataset comprising a plurality of corresponding output items. For each input item, a corresponding output item is created, wherein each input item contains some content that is not present in the corresponding output item. Creating an output item can comprise right shifting the bits of the input item by a shifting value, and performing an exclusive or operation on the input item and the results of the right shifting. The content contained in each input item that is not present in the corresponding output item is encoded in the storage address of the corresponding output item, such that the content of each input item is contained in a combination of the corresponding output item and its storage address. The output dataset comprises multiple levels.

The storage of datasets can become very space intensive. Some datasets can comprise large numbers of items of uniform size. The size of such a dataset increases linearly as the number of items increases. For example, a set of malicious code signatures stored by an anti-malware system typically comprises an ever increasing number of anti-malware signatures of a fixed width (e.g., 32 bits). As such a dataset becomes larger, the download and use time for the dataset is affected, and the memory footprint and storage requirements increase.
It would be desirable to address these issues beyond the solutions provided by conventional compression technologies.

Storing data items with content encoded in storage addresses


Systems, methods, and apparatuses are described for authenticating a user device and/or user application. A user device may receive, based on a first authentication request, a plurality of messages sent over a plurality of channels of communication (e.g., a message to a URL address associated with the user device and a binary Short Message Service (SMS) message). Based on information from the messages, the user device may transmit a second authentication request.

Network operators or service providers may provide voicemail services. Because subscriber identity module (SIM) credentials are generally required by the network operators or service providers to provide access to their network, network operators or service providers are able to use these SIM-based credentials to perform a network-based authentication. However, since SIM credentials are generally not shared across multiple network operators or service providers, virtual network operators or service providers may not have access to SIM credentials.

Methods, systems, and apparatuses for multi-factor message authentication


The present invention provides an immunogenic compound comprising the formula: ##STR1## wherein X is selected from the group consisting of methyl and hydrogen; wherein R.sub.1 is a suitable functional group of the lysergic ring;. wherein R.sub.2 is an immunogenic protein; and. wherein Y is a bridge to link R.sub.1 to R.sub.2.. The present invention also provides purified polyclonal and monoclonal antibodies specifically reactive with the immunogenic compound and reactive with the lysergic ring of ergopeptine and clavine alkaloids. The present invention further provides an antibody which is an anti-idiotype of the monoclonal antibody. Also provided are methods of prevention and treatment of fescue toxicosis utilizing the immunogenic compounds and antibodies of the present invention.

1. Field Of The Invention
This invention relates to vaccines useful to prevent and treat fescue toxicosis in herbivores. More particularly, this invention provides immunogenic compounds, a hybridoma cell line which produces monoclonal antibodies and an anti-idiotype vaccine to prevent and treat fescue toxicosis.
2. Background Art
Fescue toxicosis is a condition of livestock associated with grazing tall fescue (Festuca arundinacea Schreb) infected with its fungal endophyte Acremonium coenophialum Morgan-Jones and Gams. Inasmuch as tall fescue is widely adapted and utilized (Bums and Chamblee, 1979) and incidence of endophyte infection within pastures is high (Hill and Stringer, 1985; Shelby and Dalrynple, 1987), fescue toxicosis is a widespread problem and represents a major economic loss to the livestock industry in the United States.
Tall fescue plantings occupy over 35 million acres in the United States and Canada wherein over 90% of this acreage is infected with Acremonium coenophialum (Bacon et al., 1988). Extreme expense and environmental concerns make it impractical, if not impossible to approach the problem of fescue toxicosis by replanting affected acreage with endophyte-free cultivars. Moreover, the endophyte and plant appear to exist in a symbiotic relationship, suggesting potential problems with the long term survival of endophyte-free cultivars.
Signs of fescue toxicosis include lethargy, reduced weight gain, increased respiration, gangrenous lesions on the extremities, and roughened hair coats. Physiologically, affected livestock have reduced serum cholesterol and alkaline phosphatase (Bond et al., 1984; Stuedemann et al., 1985; Lipham et al., 1989), decreased visceral and peripheral blood flow (Garner et al., 1978), increased D2 receptor affinity in the corpus striatum (Mizinga, 1991), and reduced prolactin secretion (Lipham et al., 1989). Therefore the pathophysiology of fescue toxicosis includes effects on basal metabolism, cardiovascular, central nervous, and endocrine systems.
The toxic compounds of Acremonium coenophialum infected fescue have yet to be conclusively identified (Putnam et al., 1991). Four classes of alkaloids produced by the endophyte/tall fescue association (loline, peramine, clavine, and ergopeptine) are potentially toxic to grazing livestock. The endophyte, a clavicepitaceous organism, produces ergopeptine alkaloids. Eyropeptine alkaloids are lysergic acid derivatives including agroclavine, elymoclavine, ergovaline, ergosine, and ergocornine (Siegel et al., 1991). In addition, plant derived loline alkaloids are produced in response to the fungal endophyte which are presumed to have a regulatory role in limiting endophyte habitat within the plant. These loline alkaloids are also suspected of being involved with the toxicosis syndrome (Bush et al., 1979). The loline alkaloids include the pyrrolizidine bases N-formyl loline, N-acetyl loline, and loline alkaloids (pyrrolizidine alkaloids).
Many attempts have been made to identify the alkaloid components of endophyte infected tall fescue which produce fescue toxicosis without a definitive answer. Although the unsaturated pyrrolizidine alkaloids have hepatotoxic activity (Mattocks, 1971), intraluminal infusion of saturated pyrrolizidine alkaloids found in tall fescue produced no symptoms of fescue toxicosis (Yates, 1973). However, in combination with acetylcholine, saturated pyrollizidine alkaloids are endowed with smooth muscle contracting capabilities which could result in gangrenous conditions (Bruce et al., 1971).
University of Kentucky researchers reported pyrrolizidine alkaloids as the major toxin associated with fescue toxicosis and demonstrated that thiamine treatment partially alleviated symptoms associated with the disease (Doughtery et al., 1991) (See also U.S. Pat. No. 4,755,519).
However, another group has previously shown that dorsal pedal veins contracted in vitro when exposed to various concentrations of purified lysergic acid derivatives but a mixture of pyrrolizidine alkaloids failed to produce contractile responses (Solomons et al., 1989).
Circumstantial evidence exists that the ergopeptine alkaloids are responsible for fescue toxicosis (Testereci et al., 1991). It has been shown that serum prolactin is frequently decreased in cattle grazing endophyte-infected tall fescue (Thompson et al., 1987) and ergot alkaloids are potent inhibitors of prolactin secretion (Goldstein et al., 1980). In addition, administration of metoclopramide, a type D2 receptor antagonist, increased serum prolactin and weight gains, and changed hair coats from classical fescue toxicosis appearances of long, rough and bronzed to black and shiny in Angus steers (Lipham et al., 1989). Metoclopramide, however, has minor cross reactivity with other receptors which does not exclude effects other than type D2 activity. Likewise, in vitro research evaluating the vasoconstrictive effects of alkaloids assumes that ingestion of tall fescue results in their presence in serum (Solomons et al., 1989).
Therefore, as can be appreciated by a review of the literature, the cause of fescue toxicosis remains unresolved. In addition, despite great economic losses, no economically feasible method to prevent or treat fescue toxicosis exists.
The present invention satisfies this long felt need to protect livestock from fescue toxicosis by providing antibodies and compounds for immunization against fescue toxicosis as well as a method of therapy for affected animals.

Vaccines and methods for preventing and treating fescue toxicosis in herbivores

The United States of America as represented by the Secretary of Agriculture

The University of Georgia Research Foundation, Inc.