A data processing system providing user interaction in multiple natural languages, including a processor for executing application programs and a memory for storing message files corresponding to the application program in at least one natural language and a link table for storing links between the application program and corresponding message files, wherein a link for an application program stores a natural language and a pointer to its message file, wherein the operating system for the processor establishes links when a message file is loaded into memory. The data processing system nests language information for nested application programs. A fall-back mechanism is used to provide a default language when a language desired by a user is not available or when nested languages are not available. The system may send and receive messages in multiple natural languages for multiple users using different application programs simultaneously in a manner transparent to the user and the application programmer with the assistance of the operating system involvement in establishing links, using default languages and nesting language information.

Most data processing and computer systems provide interaction with a user in only one natural language, such as English, French or German. Such natural languages are those used in speech by individuals and are distinct from computer programming languages. Due to the international context in which computers increasingly are being used, a need has arisen for data processing systems which interact with users in any of multiple natural languages, or "interaction languages".
In most data processing systems, interaction with a user involves sending and receiving messages between the user and the data processing system. To facilitate such message sending and receiving, a data processing system normally has standard instructions for sending output messages to the user and also has similar instructions for interpreting input messages received from the user. An application programmer uses these instructions in an application program in order to provide interaction between a user and the data processing system when the program is run, i.e., when the system is configured by the program and processes described by the program are executed by the configured system.
A well-known technique for sending and receiving messages involves placing output and input messages for an application program in a file or in a location separate from the application program. Such messages are referenced by the application program via codes or indices. This technique is known as "externalizing". The application program occasionally retains messages, i.e., which are not externalized, for use as default messages, for example. These messages are sometimes referred to as "hard-coded."
When an application program and corresponding externalized message file are employed in a system, a link is created, at run time, between the application program and the message file. This link specifies that the message file is to be used in conjunction with the application program to provide output and input messages for the program. In current systems, either a user or the application programmer has to explicitly specify the message file which is to be used with the application program. Hence, the link is not transparent to the programmer, and the application programmer as well as the user must know the names of available message files. In a system which supports multiple interaction languages, multiple message files are needed, thus complicating the burden on the programmer and the user.
A current multi-lingual system which adapts an "externalizing" approach, is the Native Language System (NLS). NLS is a system interface developed by X/OPEN which is a joint initiative by members of the business community to integrate evolving standards into a common, beneficial and continuing strategy. The system interface is a set of commands available for use in application programs to configure and manipulate a data processing system. Many implementations for supporting the NLS interface exist, but each implementation shares the functionality defined by X/OPEN in its Portability Guide, (1989), (note especially volume 2).
In NLS, each externalized message file for an application program containing output and input messages in an interaction language is identified by a string name known as a "catalog descriptor". With NLS an application programmer needs to know the catalog descriptor for a message file in order to load the message file into memory, and to retrieve messages from it. The catalog descriptor may be constructed from a default value, such as a system-wide default or a per-user default. In NLS, the user default value overrides the system default and may be used to override the default for an application program. No nesting capability is provided. If a message file in a desired language is not available for an application program, the user normally receives hard-coded messages of the application program. Because the application programmer uses the name of the message file in the application program, and also handles the opening and closing of message files, problems arise in the development of application programs.
A first problem with the NLS system is the required involvement of the application programmer in the management of message files. Periodically, message files for an application program are modified, or new message files are added for use by the application program. Such modifications and additions may require changes to application programs that reference the modified or additional message files. As a result, when such message files are provided to a customer, the application program must be updated as well, hence increasing both manufacturing costs to the application program supplier and material costs to the customer.
A second difficulty of the NLS system is that it requires an application programmer to develop a program for handling instances where a message file is not found during attempts to open the file or to retrieve a message from the file. Typically, such a program provides a hard-coded default message for use when a message or message file is not found. However, such default messages are provided solely at the discretion of the application programmer. As such, application programs produced by different application programmers may not have uniform default mechanisms. Thus, such application programs are not consistent in this respect.
Multi-lingual interaction in NLS is also not transparent to the user. For example, the user may be asked to select an interaction language. However, this capability is provided only at the discretion of the application programmer, and thus may not be consistent. This lack of a consistent mechanism for selecting an interaction language may be confusing both to the user and to the application programmer. Furthermore, a user often has to specify a desired interaction language more than once when using layered processes. Such inconsistent systems are inconvenient and annoying to use and maintain.
Finally, due in part to the lack of transparency and consistency, these systems fail to make use of the "nesting" capability of a system. That is, when an application program runs another application program (i.e., it makes a "nested" call), interaction language information is not "nested". A user also is not able to specify different languages for different program levels.
Application libraries are commonly used in large multi-user systems and contain common subroutines accessed by a number of application programs. Access to these application libraries often involves a kind of nested call. Without the provision of multi-lingual support for nested application programs or libraries, message handling for application libraries may be inconsistent or even unpredictable.
Accordingly, it is an object of the present invention to provide a data processing system and method capable of supporting user interaction in any of multiple natural languages in a manner that is transparent both to the user and to the application programmer.
It is another object of the present invention to provide a data processing system wherein the management of message files is transparent to the application programmer.
It is another object of the present invention to provide a data processing system that links a message file to an application program or library without user interaction.
It is still another object of the present invention to provide a data processing system which may support nested calls in different interaction languages.

Data processing system providing user interaction in multiple natural languages


The cooling of components (26) of a vehicle (10) carrying a turbine engine (12) and a fuel supply (24) for the engine (12) without the excessive consumption of bleed air is achieved in an apparatus which includes a fuel recirculating system (34), a first heat exchanger (60) for rejecting heat from selected components (26) of the vehicle (10) to fuel flowing through the fuel recirculating system (34), and a cooling device (32) including a second heat exchanger (100, 202) for rejecting heat from the fuel to the cooling device (32) as the fuel flows through the fuel recirculating system (34).

The thermal management of advanced aircraft is becoming increasingly more difficult because of the rising heat loads associated with advanced avionic systems and increased aircraft speeds and capabilities. This is especially true for advanced fighter aircraft that utilize radar systems which generate a relatively high heat load and which need to be cooled to approximately 30.degree. C. for reliability and life cycle cost considerations.
Conventionally, a combination of ram air cooling and the cooling capacity of the fuel flow to the main engines of the aircraft has been utilized to effect the thermal management of these heat loads. Under most operating conditions, the cooling capacity of the fuel delivered from the fuel tank to the combustors of the aircraft main engines is insufficient to absorb the total heat load of the aircraft. This results in an excess heat load that is absorbed by the ram air cooling. However, the ducting for the ram air cooling circuits takes up substantial aircraft volume, thereby decreasing the volume available for fuel and necessitating a larger/heavier aircraft to achieve a desired range for the aircraft. Additionally, there is a significant drag penalty associated with directing the ram air through the ram air scoop and ducting.
It is known to absorb the excess heat with an air cycle cooling system, rather than with ram air cooling. Examples of such systems are the Thermal and Energy Management Module (TEMM) (developed by a team of McDonnell Douglas, Pratt & Whitney, and Allied Signal) and the Integrated Power Package (IPP) (developed by Lockheed Martin). These systems integrate the functions of the environmental control system (ECS), the auxiliary power unit (APU), and the emergency power unit (EPU) into one rotating machine and associated valves and heat exchangers. The rotating machine is essentially a cooling turbine combined with a multi-mode gas turbine engine with a generator output for ground and emergency operation. To provide the cooling function for removing the excess heat load, bleed air from the compressor section of the main engine is used to drive the power turbine of the gas turbine engine which in turn drives the compressor of the gas turbine engine. The compressor provides a compressed air flow to a heat exchanger provided in the fan bypass duct of the main engine. The compressed air flow is cooled in the heat exchanger and then delivered to the cooling turbine which expands the air flow to provide a cold air flow for cooling the aircraft cabin and other components of the aircraft.
By integrating several formerly separate subsystems and eliminating the use of ram air cooling and its associated ducting, the TEMM and IPP systems allow for a lower weight, cost and volume package for an aircraft in comparison to conventional aircraft having non-integrated subsystems and significant ram air cooling. However, because the TEMM and the IPP systems divert a significant amount of bleed air from the compressor section of the main engine to drive the power turbine of the gas turbine engine, these systems consume much higher amounts of bleed air in comparison to conventional systems and can potentially have an adverse impact on conventional engines and the range of the aircraft. For example, the withdrawal of approximately 200 lbs. per minute of bleed air during a high altitude (approximately 50,000 feet) cruise at approximately mach=0.9 corresponds to approximately 900 horsepower of work from the main engine turbines. This requires higher fuel flows and turbine inlet temperatures in order to compensate for the lost air flow through the turbines because they must produce the 900 horsepower without the benefit of expanding the diverted bleed air flow through the turbine stages. This requirement for more fuel to accomplish any given mission undesirable increases the aircraft's takeoff gross weight.
It is also known to employ a vapor cycle cooling system to provide cooling for the radar avionics of the aircraft. This system is utilized on the F22 fighter aircraft wherein a polyalphaolefin coolant, commonly referred to as PAO coolant, flows from the radar avionics to an evaporator of a vapor cycle system where the coolant is cooled and then recirculated to the radar avionics. The compressor of the vapor cycle system is driven by an electric motor and the condenser of the vapor cycle system is cooled using the fuel flow to the engine. Additionally, a PAO/fuel heat exchanger is utilized to provide backup cooling for the radar avionics if the vapor cycle cooling system fails.
Another approach for providing cooling for an aircraft is disclosed in U.S. Pat. No. 5,414,992 to Glickstein. Glickstein discloses a cooling system wherein bleed air from the compressor of the main engine is expanded through a cooling turbine to provide cold air and shaft power for aircraft components. A heat exchanger cooled by fan air flow diverted from the fan section of the main engine is utilized to precool the bleed air prior to expanding the bleed air across the cooling turbine.

Thermal and energy management method and apparatus for an aircraft


A method of measuring and calculating (preferably by a computer with output to a user) tGSH (total glutathione very particularly defined) with sample preparation and assay methods that have been confirmed to provide accurate and reliable tGSH and related diagnostic assays in blood or tissue from a patient.

Field of the Invention
Measurement of total Glutathione in blood and other body fluids and tissues must be accurate in order to have diagnostic significance or the ability to participate in drug metabolite screening.
Description of Related Art
Previously, glutathione deficiency was examined as a possible prognostic for survival in Acquired Immunodeficiency Syndrome (AIDS), as disclosed for example in U.S. Pat. No. 5,843,785. In that patent, general glutathione levels of whole blood and/or T-cells of HIV positive patients were determined (directly or indirectly) as an indication of the likely period of survival, as well as the need for agents for enhancing the glutathione levels. But the determination made was not accurate enough to make any kind of correlation with survival expectancy of HIV positive patients. Moreover, it was also mentioned "referring to glutathione levels, it will be understood that it is the value determined by an assay which can be used for comparisons, but does not provide an absolute value". Therefore since the glutathione determinations were not accurate and absolute, the stated hypothesis was not valid enough to corroborate probability of survival in HIV positive patients. The probability of survival expectancy of HIV positive patients does not depend on one particular biomolecule measurement such as glutathione, but on several other conditions associated with the etiology of the disease. The methods both (HPLC and FACS) used for the determination glutathione levels are not robust enough to address the problems associated with quantification like reduced glutathione oxidation, and conjugates formation.
Similarly, in Pastore, G. Federici, E. Bertini, F. Piemonte, "Analysis of glutathione: implication in redox and detoxification," Clinical Chim Acta 333 (2003) 19-39, blood concentrations of reduced glutathione (GSH) in various pathologic conditions, and the statistical significance of the purported validation one or more sub-species, are indicated as being diagnostically significant. Unfortunately, most if not all of the asserted data are not accurate, which presents a significant problem for physicians in assessing and treating patients. In many cases the imprecision of these GSH and GSSG numbers overlap as they are not compared with confidence intervals but with means which are not statistically different.
United States Published Patent Application No. US2011/0144205 A1 hypothesized that glutathione is a key biomarker for heart failure asymptomatic patients, stating that "inflammation and oxidative stress are key components of in the pathophysiology and progression of heart failure and are strongly associated with the disease severity." Chemically, oxidative stress is associated with increased production of oxidizing species or a significant decrease in the effectiveness of antioxidant defenses. Therefore, these antioxidant defenses can be not only glutathione but also can be vitamin E, vitamin C, enzymes like superoxide dismutase, metallothionein, etc. The method for quantification of glutathione mentioned is not accurate and precise enough to correct for glutathione oxidation and conjugate formations.
In "Methods for the Quantitation of Oxidized Glutathione," U.S. Pat. No. 6,235,495 B1, the method used for quantification of oxidized glutathione based on the assay developed by Tietze, which is based on spectrophotometric determination of the reaction of the Ellman's reagent with Glutathione disulfide. The observation is made by assessing the color at a particular absorbance. The invention mentioned in this patent is the use of 1-methyl-2-vinylpyridinium trifluromethanesulfonate (M2VP) to prevent the conversion of GSH to GSSG without interfering with glutathione reductase in the biological sample. However, this method is not accurate and precise enough to make since clinical and therapeutic decisions, it is based on the color change at particular absorbance and any other disulfide present in the biological sample can interfere with the process and can lead to false positive result.
The invention in the published U.S. Patent Application No. US2009/0029409 involves determination of oxidative stress biomarker, which can be varied by perturbation of glutathione levels in the blood. The oxidative stress biomarker candidate identified is ophthalmic acid, but the mechanism as to how glutathione is affected has not been established clearly. Although reduced glutathione is present in low concentrations and prone to oxidation in blood, it still can be quantified by using NEM in the sample preparation which minimizes the conversion of reduced glutathione to oxidized glutathione. The normal range of ophthalmic acid present in the blood has not been mentioned and whether its production is varied by any other biomolecule other glutathione has not been discussed.
Zhenying Yan and coinventors have described, in two US patents, 2005/US0287623 and 2011/US788186, a method for detecting reactive metabolites by isotope trapping with a mass spectrometer for the purpose of toxicological assessment. In both Yan patents, the European patent by Michael J. Avery (EP, 1,150,120, October 2001) has been provided as a prior art that involves incubating a test compound with a microsomal drug metabolizing enzyme system in the presence of a form of glutathione and then, detecting certain glutathione adducts formed therefrom using tandem mass spectrometry. Yan points out that Avery method will identify reactive metabolites as well as non-reactive components (including both unreactive metabolites and components of the reaction mixture) formed as a result of common response in mass spectrometry detection, thus resulting in false positives. In the 2005-Yan patent, a method of detecting reactive metabolites of a drug candidate whereby the drug candidate was mixed with a non-labeled trapping agent, an isotopically labeled trapping agent and an enzyme. Purportedly improving on the 2005-patent, Yan and Norman D Huebert, U.S. Pat. No. 7,884,186 B2, disclosed in the 2011 text that the 2005-patent detects only "soft" metabolites, but does not simultaneously detect both "hard" and "soft" reactive metabolites. In the 2011 Yan specification, the "soft" metabolite is described as any electrophilic metabolite which comprise at least one substituent group which readily reacts with soft electrophiles, such as the sulfhydryl group in cysteine and the —SH group on the compound of the formula. Disclosed examples of soft metabolites were given as quinones, quinone imines, immunoquinone, methids, epoxides, arene oxides and nitrenium ions. The same patent described a hard metabolite as an electrophilic metabolite which comprises at least one substitute group which readily reacts with the —(CH2)4—NH2 of the compound of the formula. The disclosed example of such substituent group was given as aldehydes. Additionally, the same patent claims that its isotope trapping technique was capable of eliminating false positives using mass spectrometric pattern recognition. There is no indisputable evidence in either of the Yan patents that would support the claims associated with the "elimination of false positives." Without standard reference materials, a mathematical basis and statistical support, such claims would not meet the criteria established for mission critical applications such as those established in the clinical, diagnostic and homeland security fields.
In the above exemplary prior art, the field attempts to identify various glutathione adducts and conjugates has therefore been fraught with fundamental problems. A need remains, therefore, for an accurate method of measuring and calculating tGSH and specific related compounds and conjugates in a patient's blood, fluid or tissue sample and the concomitant diagnostic method of interpreting the measurements and ratios for diagnostic and prognostic purposes. A need also remains for improved accuracy in situ toxicological drug screening of biologic drugs involving GSH, GSH species, GSH conjugates, and GSH metabolites.

Accurate measurement of glutathione for disease diagnosis and drug metabolite screening


Exemplary piston assemblies and methods of making the same are disclosed. An exemplary piston assembly may include a piston crown and a piston skirt that is received in a central opening of the crown. The piston crown may include a ring belt portion defining, at least in part, a cooling gallery. The crown and skirt may each further include corresponding mating surfaces that extend about a periphery of the crown and skirt. The skirt mating surface and crown mating surface may generally be secured to each other that the crown and the skirt cooperate to form a continuous upper combustion bowl surface. The skirt and crown may cooperate to define a radially outer gap about a periphery of the piston crown.

Internal combustion engine manufacturers are constantly seeking to increase power output and fuel efficiency of their products. One method of generally increasing efficiency and power is to reduce the oscillating mass of an engine, e.g., of the pistons, connecting rods, and other moving parts of the engine. Engine power may also be increased by raising the compression ratio of the engine. Raising the compression ratio of an engine also generally raises the pressure and temperature within the combustion chamber during operation.
Engines, and in particular the pistons of the engine, are therefore under increased stress as a result of these reductions in weight and increased pressures and temperatures associated with engine operation. Piston cooling is therefore increasingly important for withstanding the increased stress of such operational conditions over the life of the engine.
To reduce the operating temperatures of piston components, a cooling gallery may be provided about a perimeter of the piston. A coolant such as crankcase oil may be introduced to the cooling gallery, and may be distributed about the cooling gallery by the reciprocating motion of the piston, thereby reducing the operating temperature of the piston.
At the same time, the cooling galleries may increase overall complexity of the piston assembly. For example, cooling galleries may require additional component, such as cooling gallery covers, in order to encourage proper circulation of a coolant throughout the cooling gallery. A cooling gallery may rely on a cover plate fitted to the piston crown that generally traps coolant (e.g., oil) within the cooling gallery, thereby increasing the cooling effect of the gallery. The additional components also add complexity, however. Additionally, cooling galleries may be expensive and/or difficult to form in smaller piston applications such as in the case of lightweight or light duty pistons.
Accordingly, there is a need for a piston that minimizes overall piston weight and manufacturing complexity, while also allowing adequate cooling, such as by providing a cooling gallery.


The invention comprises a method and apparatus for assigning at least one virtual concatenation group member to a virtual concatenation group at a terminating node. Specifically, the method comprises receiving originating configuration information comprising at least one assignment parameter and at least one originating capability parameter, identifying terminating configuration information associated with the terminating node where the terminating configuration information comprises at least one terminating capability parameter, comparing the at least one originating capability parameter to the at least one terminating capability parameter, and assigning the at least one virtual concatenation group member to the virtual concatenation group on the terminating node using the at least one assignment parameter in response to a determination that the at least one originating capability parameter and the at least one terminating capability parameter are compatible.

In general, next-generation networks (e.g., synchronous optical network (SONET)/synchronous digital hierarchy (SDH) networks) comprise various combinations of technologies, such as virtual concatenation (VCAT), generic frame processing (GFP), and the like. In VCAT, service signals to be transported over a transport technology (e.g., SONET/SDH) are inversely multiplexed onto a set of individual transport signals. The individual transport signals are independently transported over the network to a far-end network element which recovers the service signal from the transport signals. In VCAT, a virtual concatenation group (VCG) comprises a set of transport signals used to transport a service signal, and a VCG member comprises an individual transport signal from the set of transport signals.
In general, network elements supporting VCAT capabilities comprise units operable for supporting 1-64 VCGs (where each VCG comprises 1-256 VCG members). Furthermore, such network elements typically support 8-32 such units, thereby enabling a network element to support in excess of 2000 VCGs. In existing network elements, assignment of VCG members to VCGs is performed manually (i.e., by manual configuration). Furthermore, the provisioning must be performed consistently at both the originating end and the terminating end of a VCG in order to transport a service signal (i.e., inconsistent VCG configurations result in at least a partial loss of capacity available for transport of the service signal).
Unfortunately, as the number of VCGs (and, therefore, the number of VCG members) supported by network elements continues to grow, problems associated with manual VCG member assignments (e.g., increased effort, increased error probabilities, and the like) are exacerbated. Furthermore, such VCG member assignment problems are reencountered during service modifications, thereby resulting in increased operational cost, decreased network reliability, and the like.

Method and apparatus for automatically assigning virtual concatenation group members to virtual concatenation groups


A system and method for enabling an efficient Zero Phase Restart (ZPR) of a device. The structure is based on deploying normalized timing gradient (NTG) blocks (501 and 502) in pairs, each circuit employing an orthogonal phase error transfer function characteristic (having one TG circuit sample orthogonally in relation to the other), for example, PR4 and EPR4 modes ideal sampling instances of a preamble. An NTG block (501 or 502) is selected based on having a native timing sampling instance with a phase error that is closest to zero. Since there is an equal chance that either of the circuits in a circuit pair will be selected, if the circuit implementing the current non-native architecture is selected, a separate signal is generated. This signal adds the equivalent of 180xc2x0 to the error value that is provided to the timing recovery circuit. For example, by iterating the process after the special case of a zero phase restart (ZPR) operation, the native sampling instance is xe2x80x9cforcedxe2x80x9d to be selected thereafter.

The present invention relates to a method for estimating phase error, for example, of a timing recovery loop. More specifically, a preferred embodiment relates to efficiently selecting the starting phase for a timing recovery process in a sampled data detection system, such as a PRML or EPRML channel in a magnetic recording system.
Digital mass data storage devices such as a disk drive record digital sequences onto media and retrieve them from an analog signal, unfortunately corrupted by noise from various sources. It is desired to achieve the highest recording density per unit area while attaining an acceptable probability of error between the signal recorded and that retrieved. To achieve this goal, a disk drive""s read channel uses equalization and coding prior to processing in a digital signal processor. One solution is to use run-length limited (RLL) codes with a RLL encoder and decoder.
Digital mass data storage devices use RLL codes, when applied to data only, to improve signal-to-noise ratio (SNR) or to implement frequent updates to the timing recovery and automatic gain control loops, or both. The RLL codes use two parameters, d and k, controlling the minimum and maximum number of symbol intervals between transitions in the input signal, respectively. For a given d, the RLL code dictates at least xe2x80x9cd+1xe2x80x9d, and at most xe2x80x9ck+1xe2x80x9d, symbol intervals between transitions. Conventionally used codes are those with (d, k) constraints of (1, 7) and (2,7), generally used with peak detection methods.
These asynchronous methods detect single pulses. The xe2x80x9ckxe2x80x9d constraint insures that a non-zero channel output is produced with some minimum frequency to maintain robust operation of timing recovery and AGC loops. The xe2x80x9cdxe2x80x9d constraint insures acceptable SNR with peak detection.
Conventional methods for estimating the initial phase error for ZPR have been applied to determine xe2x80x9czero-crossingsxe2x80x9d of analog, i.e., continuous, time signals. Of course, this is inappropriate for handling discrete, or digital, pulses.
Some conventional disk drives, for example, use continuous time peak detection designs to recover digital data written as a series of magnetic transitions on a recording surface of a rotating magnetic disk. A voltage controlled oscillator (VCO) uses an xe2x80x9cEnablexe2x80x9d command for controlled starting and stopping of the oscillator. When the xe2x80x9cEnablexe2x80x9d command is asserted, the VCO begins oscillating in a known state. The rising edges of the clock""s transition occur at a fixed delay interval after xe2x80x9cEnablexe2x80x9d is asserted.
In turn, xe2x80x9czero phase restartxe2x80x9d (ZPR), also sometimes referred to as zero phase start, senses a logic transition of a read gate control signal (xe2x80x9cRd Gatexe2x80x9d) from inactive to active, and disables the VCO. Upon arrival of a subsequent xe2x80x9ctransition edgexe2x80x9d at the ZPR logic, xe2x80x9cEnablexe2x80x9d is reasserted and the timing control circuit VCO is restarted. A timing delay block compensates for the delays associated with detection and restart, which results in the next transition edge and the first clock output coinciding at the input to the phase-frequency detector. Starting phase error,  is brought near zero while PLL acquisition time is reduced.
One effect that limits the recording density in mass data storage systems is intersymbol interference (ISI). ISI is endemic to the band-limited nature of the head/media combination and results in overlapping responses. That is, at a given time, the output signal contains the response due to the input signal and the responses from some previously recorded symbols. This overlap increases as recording density or disk rotation speed is increased, yielding overlap patterns that are generally very difficult to decode.
To reduce the complexity required to decode, the readback signal in the read channel is first equalized to a prescribed partial response (PR) signal. PR signals permit a controlled overlap of responses in the output signal. A priori knowledge of the xe2x80x9ccontrolled overlapxe2x80x9d significantly reduces the complexity of the required detector, compared to that required for an unequalized signal.
One commonly-used PR target signal in digital magnetic recording systems is characterized by the transfer function P(D)=1xe2x88x92D2, where D is the transform of the unit symbol delay operation. This PR signal is commonly referred to as a xe2x80x9cClass IV PRxe2x80x9d or xe2x80x9cPR4.xe2x80x9d The noise-free output response at a suitably prescribed sampling instant for PR4 is given by
Y(nT)=a(nT)xe2x88x92a[(nxe2x88x922)T]xe2x80x83xe2x80x83(1)
where:                               n          =                      xe2x80x83                              2                ,        3        ,        …                                                      a                                      (              nT              )                                =                      xe2x80x83                                          the                                      xe2x80x83                                    input                                      xe2x80x83                                    symbol                                      xe2x80x83                                    at                                      xe2x80x83                                    time                                      xe2x80x83                                    instant                                      xe2x80x83                                    nT                          ,                  normally                                xe2x80x83                              picked                                                  xe2x80x83                                              from                                      xe2x80x83                                    a                                      xe2x80x83                                    binary                                      xe2x80x83                                    alphabet                    ,                                    {                              0                ,                1                            }                                                  xe2x80x83                                    or                                      xe2x80x83                                                                  {                                  1                  ,                                      -                    1                                                  }                            .
That is, the output sample at time instant, nT, involves the overlap of two input symbols, a(nT) and a[(nxe2x88x922)T].
The equalized signal is then detected using a sequence detector such as a Viterbi Detector (based on the Viterbi Algorithm). This combination of PR4 and Viterbi detection is commonly referred to as xe2x80x9cPRMLxe2x80x9d for xe2x80x9cpartial response maximum-likelihood.xe2x80x9d
To increase storage density and throughput rate, sampling techniques, such as the above Partial Response (PR) signaling and Maximum Likelihood (ML) sequence detection are used.
The choice of the PR target signal is dictated by the linear density of the recording (as well as additional functions that may be required of the system). A single system may require two different PR target signals, e.g., PR4 and EPR4. Many PR targets exist for magnetic recording and are now commonly referred to as the xe2x80x9cExtended Class IVxe2x80x9d family of PR signals. The Extended Class IV family of PR signals is defined by the polynomials P(D))=(1xe2x88x92D)(1+D)n, where n is a positive integer. Note that n=1 yields the standard PR4 signal; while n=2 yields EPR4; and n=3 yields E2 PR4, etc.
Correct operation of any PRML system depends on sampling the readback signal synchronously. Even small time shifts from the correct sampling instant act to distort the sample values. To maintain proper timing of the read data, a timing recovery circuit, often a PLL, is used to adjust the phase of a VCO based on the phase error,  determined by a digital phase error detector receiving input from an analog-to-digital converter (ADC).
During acquisition, the phase error,  is defined as being zero when the rising edge of the clock signal is aligned with the ideal sampling instances of the input signal. A non-zero phase error,  causes the error detector to send a signal to a loop filter that outputs a signal proportional to the phase error. This signal shifts the instantaneous frequency of the VCO in order to subsequently match the phase of the input signal.
A PRML read channel uses ML detectors to xe2x80x9creadxe2x80x9d data based on sampled sequences of an analog waveform read from a disk, rather than by analyzing a single peak as in conventional peak detection. These samples are obtained by using an ADC that samples and quantizes the read waveform at predetermined sampling intervals. The intervals are controlled by a clock synchronizing the ADC and the incoming signal. The clock also must be phase aligned to the incoming signal.
To achieve proper timing and phase synchronization, a conventional PRML read channel uses a timing control circuit to acquire and lock frequency and phase synchronization. The timing control circuit uses a PLL circuit to generate a phase-coherent clock so that data samples may be taken at predetermined locations along the input signal. It is necessary to first lock the PLL circuit to a reference so that the required sampling frequency can be acquired and tracked.
A phase detector processes the signal samples to calculate a phase error,  between the actual and desired signals. A compensation to this phase error is used to adjust the sampling frequency that is typically the output of a VCO, with the compensation for the phase error value as the control input. The output of the VCO controls the sampling period of an ADC. Conventionally, long acquisition times are addressed by applying a relatively large initial correction to the VCO, thus enabling a quick phase match. Subsequent phase locking can then proceed more rapidly, while avoiding the reverse-slope null.
The amount of correction is determined by sampling phase difference at start of fast acquisition. The instantaneous phase and frequency of the signal are determined by digital processing as opposed to comparing signal transition edges using peak detection. A timing recovery circuit processes the samples to estimate phase,  and frequency, {circumflex over (f)}, errors. In one application, using part digital and part analog processing, these estimates are forwarded to a timing control DAC (not shown) and converted into analog error estimates for timing recovery circuit processing.
The time it takes a timing recovery circuit to recover a synchronous data clock signal impacts both the speed of acquisition and the amount of required disk space. In conventional disk drives, when the xe2x80x9cREADxe2x80x9d mode is entered, the PLL acquires the initial data clock frequency, f, and phase, xcfx86, from a known preamble waveform, most often a sinusoid, that precedes the input signal.
By minimizing PLL acquisition time, performance and capacity are improved. Early conventional PLLs had long acquisition times, and failed to lock within a desired maximum time. This problem is identified in a paper by Floyd M. Gardner entitled xe2x80x9cHangup in Phase-Lock Loopsxe2x80x9d, EEE Transactions on Communications, Vol. COM-25, No. 10, October 1977. Gardner observes that acquisition may start around a xe2x80x9creverse-slope nullxe2x80x9d, i.e., a metastable point where the initial phase difference is halfway between two stable phase-locked operating points. In this instance, acquisition may take additional cycles. Further, the presence of non-negligible noise can exacerbate this.
There are other methods for acquiring and tracking a sampling frequency. Timing recovery methods for synchronous data receivers have been investigated by K. H. Mueller and M. Mxc3xcller, xe2x80x9cTiming recovery in digital synchronous data receivers,xe2x80x9d EEEE Trans. Commun., Vol. COM-24, pp. 516-530, May 1976, incorporated herein by reference. Specifically, for PRML it has been proposed by F. Dolivo, W. Schott, and G. Ungerboeck, xe2x80x9cFast timing recovery for partial response signaling systems,xe2x80x9d Int. Conf. Commun. ""89, ICC""89, Boston, Mass., June 1989 (incorporated herein by reference) to update the timing phase at time instant nT using the timing gradient defined as:
(error)=xe2x88x92ynxc3x97xnxe2x88x921+ynxe2x88x921xc3x97xnxe2x80x83xe2x80x83(2)
where:                               y          n                =                  the                                xe2x80x83                              sampled                                xe2x80x83                              value                                xe2x80x83                              at                                xe2x80x83                              n                                                  x          n                =                  the                                xe2x80x83                              ideal                                xe2x80x83                              sample                                xe2x80x83                              value                                xe2x80x83                              that                                xe2x80x83                              is                                xe2x80x83                              closest                                xe2x80x83                              to                                xe2x80x83                                                        y              n                        .
In a PRML channel, xn is restricted to the values +1, 0, or xe2x88x921. Once  is obtained, a PLL circuit is used to recover the sampling clock. The PLL operation is divided into two stages, acquisition and tracking.
Conventionally, a sinusoid is written onto the disk, usually at the start of each track. It is known as the preamble. Following the preamble on the disk is the user data that is sampled in tracking mode. The preamble is read during the acquisition mode and data are read during the tracking mode. Since the sampling clock should be at the ideal sampling frequency and phase after acquisition, the PLL""s bandwidth is lowered in the tracking mode to reduce timing jitter.
These designs use a timing gradient (TG) calculated using actual signal samples and estimated signal samples obtained from symbol-by-symbol decisions. See xe2x80x9cTiming Recovery in Digital Synchronous Receiversxe2x80x9d by K. H. Mueller and M. Mxc3xcller, supra.
One inherent drawback of these designs is that during acquisition the sampling point may occur at the point halfway between the desired sampling times. Consequently, the method for correcting the phase may reverse its direction of adjustment several times in the vicinity of this metastable equilibrium point for an extended period of time. Although this xe2x80x9chang-upxe2x80x9d effect does not frequently occur, the length of the acquisition preamble must be sufficiently long so that the system may still synchronize given this situation. A long preamble, however, reduces the total amount of storage space available for user data.
A further concern is the non-linear characteristic of the timing gradient circuit when tracking random user data. Because the method for calculating the timing gradient is based on approximating the slope of the pulses, the gain of the timing gradient circuit varies when tracking random user data due to inconsistent pulse slopes. This variation in gain results in less than optimum timing recovery.
Another approach uses a single xe2x80x9cTG circuitxe2x80x9d to gather a rough estimate of the ideal sampling instances. This yields ZPR samples that may be metastable. Further, if these samples are averaged to reduce noise contributions, and, if xe2x80x9changupxe2x80x9d is to be avoided, a hysteresis effect must be introduced in order to reduce the probability of reversals in the once chosen direction of timing and phase adjustment. Having this additional function, i.e., the introduction of hysteresis, to address further complicates the solution and also reduces performance by increasing latency.
A method for avoiding the xe2x80x9chang-upxe2x80x9d effect in order to reduce the preamble length has been perfected. With this method, a sliding threshold, based on past estimated values around X(n), introduces a hysteresis effect that makes reversals in timing phase adjustments very unlikely. However, the estimated sample values around X(n) are reconstructed from the signal sample values, Y(n), and are therefore subject to error. Errors in the estimated sample values further increase the necessary length of the acquisition preamble. In order to minimize the initial phase error between the sampling clock and the preamble, ZPR has been used with conventional timing control circuits.
Upon obtaining an initial input-signal-to-clock phase difference, the VCO is stopped in order to adjust for any phase difference. The ZPR method applies a controlled phase delay within the timing control circuit, permitting a xe2x80x9crestartxe2x80x9d of the read channel in phase alignment with the incoming signal. A ZPR circuit for timing acquisition in a PRML recording channel is described in Dolivo et al., xe2x80x9cFast Timing Recovery for Partial-Response Signaling Systemsxe2x80x9d, Proc. of ICC ""89 (IEEE), Jun. 11-14, 1989.
In conventional designs, a PLL circuit controls the timing recovery in PRML recordings. A phase detector processes the signal samples to generate a phase error,  between the actual and desired frequency. Compensation for this phase error is used to adjust the sampling frequency, e.g., the output of a VCO, the phase error compensation being the input. The output of the VCO controls the sampling instances of an ADC. It is necessary to first lock the PLL to a reference frequency so that the required sampling frequency can be acquired. Phase lock occurs when a preamble appears under the readback head of the disk drive. A longer acquisition time requires a longer preamble, thus, reducing space available for user data. One technique for locking the PLL to a reference frequency injects into the ADC a sinusoid of one fourth the nominal sampling frequency.
The PLL must be switched synchronously between the clock signal and the input signal so that additional phase corrections are not needed. Also, the PLL must not be referenced to the clock after the VCO is re-started. Should this occur, disruptive phase corrections from the clock interfere with phase locking.
Conventional ZPR designs are susceptible to noise on both the clocking and the input signal. Noise on the input signal contributes to inaccurate phase measurement, leading to inaccurate phase correction that may increase actual acquisition time. One type of noise is termed xe2x80x9cpulse pairingxe2x80x9d noise. Pulse pairing causes adjacent pulses to have alternating, i.e., early and late, phase errors. Conventional ZPR designs do not detect pulse pairing since they rely on a single initial measurement.
Other designs include a pulse position detector to detect the phase difference between data pulses and clock pulses, and an averaging circuit to determine the average amount of phase difference over several pulses. This average value is then used to stop the VCO to correct for this average phase error. Preferably, averaging takes place over an even number of pulses, thereby diminishing the effect of pulse pairing noise.
Implementations of EPRML channels have been documented by R. Wood, xe2x80x9cTurbo-PRML: A Compromise EPRML Detector,xe2x80x9d IEEE Trans. on Magnetics, vol. 29, no. 6, pp. 4018-4020, November 1993, herein incorporated by reference, and E. Eleftheriou and W. Hirt, xe2x80x9cImproving Performance of PRML/EPRML through Noise Prediction,xe2x80x9d INTERMAG 96, Seattle, Wash., April 1996, also herein incorporated by reference. These implementations universally require a signal processing block after the conventional PR4 Viterbi detector in order to optimize EPRML performance without modifying the timing recovery circuit.
Correct gain control is important because decisions about data, samples and timing all assume that system amplification is correct. For example, for PR4, the +1 and xe2x88x921 levels and for EPR4, the +2, +1, xe2x88x921 and xe2x88x922 levels, should be known a priori. Therefore, conventional mass data storage devices use a variable gain amplifier (VGA) to maintain a constant sampled signal amplitude. Controlling a VGA to maintain a constant amplitude is also known as automatic gain control (AGC). Implementing AGC during analog acquisition, the VGA sends the amplified sine wave to an equalizer, e.g., a digital FIR filter, to output an equalized signal. A feedback loop controls VGA operation during analog acquisition. Implementing AGC during digital tracking, the equalized signal is digitized in an ADC and forwarded to a detector where it is fed back to the VGA to adjust gain.
AGC functions for PRML read channels have been proposed that update the VGA gain by using the gradient derived from the following relationships:
en=ynxe2x88x92xnxe2x80x83xe2x80x83(4)
gain(en)=enxc3x97xnxe2x80x83xe2x80x83(5)
where:                                           y            n                    =                      the                                      xe2x80x83                                    sampled                                      xe2x80x83                                    value                                      xe2x80x83                                    at                                      xe2x80x83                                    n                          ,                                          x          n                =                  the                                xe2x80x83                              ideal                                xe2x80x83                              sample                                xe2x80x83                              value                                xe2x80x83                              that                                xe2x80x83                              is                                xe2x80x83                              closest                                xe2x80x83                              to                                xe2x80x83                                          y            n                                                            e          n                =                  the                                xe2x80x83                              decision                                xe2x80x83                                          error            .
Note that xn is either +1, xe2x88x921 or 0, for PR4.
Once the gain error is obtained, the AGC loop adjusts the gain of the VGA. The operation of the AGC is divided into two stages, acquisition and tracking.
During acquisition, a sinusoid with a period equal to 4T is used to provide the signal amplitude reference. Either continuous-time or discrete-time methods can be used to implement the acquisition mode. See R. Cideciyan, F. Dolivo, R. Hermann, W. Hirt and W. Schott, xe2x80x9cA PRML System for Digital Magnetic Recording,xe2x80x9d IEEE Journal on Selected Areas in Communications, Vol. 10, No.1, pp. 38-56, January 1992 and R. Yamasaki, T-W. Pan, M. Palmer and D. Browning, xe2x80x9cA 72 Mb/s PRML Disk-Drive Channel Chip with an Analog Sampled-Data Signal Processor,xe2x80x9d Proc. of IEEE ISSCC, San Francisco, 1994, pp. 278-279 incorporated herein by reference.
In the continuous-time implementation, a peak detector is used to derive the amplitude error. After acquisition, assuming that the gain of the VGA is appropriate, the bandwidth of the AGC is reduced for the tracking mode, thus reducing noise sensitivity.
EPR4 relaxes the need for equalization as compared with PR4 (for higher channel densities). Having a lower high frequency SNR than PR4enables EPR4 operation at higher linear densities. However, this comes at a price of added complexity, in turn, leading to longer processing times and lower throughput rates.
A further consideration is the non-linear characteristic of the timing gradient circuit when tracking random user data. Because the method for calculating the timing gradient is based on approximating the slope of the pulses, the gain of the timing gradient circuit varies when tracking random user data because of changing pulse slopes. This variation in gain induces sub-optimum timing recovery.
Therefore, what is needed is to provide a method and system for optimizing the restart associated with a timing recovery process. Further, the system should be capable of optimizing the starting phase for timing acquisition in multiple operating modes and should be transparent to a user.
A preferred embodiment of the present invention uses an architecture having one or more pairs of timing gradient (TG) circuits with center of zero-crossing operating points of each circuit of a pair located at opposing sampling instances, i.e., orthogonal to each other. For example, the center timing instances for a Partial Response Class 4 (PR4) detector are at       π    4    ,            3            π        4    ,            5            π        4    ,            7            π        4
along the ideal sinusoidal waveform provided as a preamble, while the timing instances for EPR4 are at   0  ,      π    2    ,  π  ,            3            π        2    ,      and              xe2x80x83            2              π      .
Further, neither circuit of the pair is required to exhibit a hysteresis property, thus reducing latency and processing complexity.
Before the initiation of a ZPR operation, each circuit of the installed pair(s) of timing gradient (TG) circuits is normalized if the two TG slopes of each pair are not the same and to allow for use of the power of two modulo arithmetics. This insures the same values for transfer characteristics. The circuits are then activated to calculate phase errors within each of their respective timing sampling instances. At the moment of ZPR activation, the one circuit of each pair of circuits that is closest to zero (i.e., gives the better quality of the phase error estimate) phase error is selected via a comparator circuit. (If more than one pair of TG circuits is used, then that circuit of all of the included circuits with the lowest error value is selected.). Since the initial phase error distribution is uniform, either of the pair (or any of the circuits of multiple pairs) has an equal chance of being chosen. In the case where a non-native TG is closer to the desired timing sampling instances, a separate signal is generated indicating that a phase shift (e.g., the equivalent of 180xc2x0 for one pair of TG circuits) should be added to the resultant phase error values. This equivalent of 180xc2x0 addition could be cyclically added either in the phase detector (internally) or in the timing circuit (externally). After initial ZPR operation, the resultant phase error should approach zero, thus xe2x80x9cforcingxe2x80x9d selection of the native TG thereafter. Note that FIG. 8a provides angular measurements of a sinusoid (preamble) and FIGS. 8b and 8c provide angular measurements of a bit.
An additional benefit of using at least one pair of TG circuits is that the resulting phase error transfer curve now has at least two extremely accurate operational points that are also signal amplitude independent. This results in any maximum incurred error being at least half what it would have been using only a single TG circuit.
Some of the salient advantages of the present invention are that it:
imposes no requirement for memory (e.g., a register) at each stage.
reduces latency.
reduces net overhead.
is ideally suited to use in those systems calling for dual operating schemes employing two different decoding architectures
performs calculations in acquisition stage when there is more time available and then flips the result to the tracking stage.
does not require hysteresis effects be introduced.
accurately estimates total phase shift while incurring a minimum hardware burden.
reduces error propagation.
uses less complicated computational architecture.
includes at least two accurate points for operation on the error transfer curve.
can be made extremely accurate by simply adding circuits to operate, as needed, in pairs.
Thus, it is a general advantage of the present invention to improve the timing recovery method in synchronous partial response magnetic recording systems.
Further, an advantage of the present invention is to provide a ZPR optimization system that determines an optimal starting phase for a timing control circuit oscillator, thereby minimizing clock recovery time.
A more specific advantage of the present invention is to provide a ZPR that uses a minimum amount of hardware and subsequent silicon area on a chip.
A further advantage of the present invention is that it provides a ZPR optimization system and control algorithm that determines the optimal restart phase for an oscillator clocking signal provided to an ADC for sampling an incoming analog signal.
A further advantage of phase optimization is minimization of the frequency transient, since frequency may be derived by integration of the phase error,  Accordingly, smaller phase errors,  result in lower frequency errors and shortened acquisition of the preamble.
In sum, the invention can achieve better noise performance by finding an average phase difference rather than an instantaneous one.
A preferred method used for the starting phase selection in a timing recovery process involves receiving a xe2x80x9cknownxe2x80x9d (to an accurate degree) frequency sampled signal at two similar TG circuits. The received sampled signal is sent in parallel to each TG circuit and a comparator, e.g., minimum of absolute value, compares the error values produced from each TG circuit. An adjusted starting phase is selected, based on a signal representing the lesser absolute value of the two error values. The timing recovery circuit is coasting during this period until the user wants to use it. The timing gradient closest to zero is then either latched or averaged over a few cycles until ZPR is initiated.

Phase detector architecture for phase error estimating and zero phase restarting


A method of manufacturing a semiconductor device. The method includes the application of a gas containing HF vapor and H.sub.2 O or alcohol vapor to a substrate. An excitation energy is applied to a flow of gas containing hydrogen to generate a plasma. Gas containing nitrogen fluoride is added to the gas containing hydrogen at a first position which is downstream from the place where the plasma is generated and at which the concentration of high energy particles in the gas containing hydrogen is negligible. The HF treated substrate is exposed to the gas containing nitrogen fluoride at a second position which is further downstream than the first position where the nitrogen fluoride is added.

a) Field of the Invention
The present invention relates to a semiconductor device manufacturing technique particularly suitable for removing a native oxide film from the surface of a silicon substrate. In this specification, the term "native oxide film" is used to mean imperfect oxide films other than thermal oxidation films.
b) Description of the Related Art
The surfaces of many semiconductors and metals are easily oxidized in air and native oxide films are formed thereon. A native oxide film formed on the surface of a Si substrate has a thickness of about 2 nm (measured by ellipsometry) and is called an imperfect silicon oxide film.
A silicon oxide film is an insulating material. If a silicon oxide film remains on the surface of a Si substrate, the contact resistance of an electrode connected to a conductive region on the Si substrate is increased.
A native oxide film on a Si substrate surface is a silicon oxide film having an imperfect crystallinity and having a film quality inferior to a thermally oxidized Si film. As the size of a MOSFET is scaled down, the gate oxide film often becomes as thin as 10 nm or less. For example, in a case where gate oxide film of 5 nm thickness is to be formed, if a poor quality native oxide film of 2 nm thickness is left on the surface of a Si substrate, a resultant gate oxide film will have degraded film characteristics.
A wet process using diluted hydrofluoric acid is known as a process of removing a native oxide film on a Si substrate (G. S. Higashi et al., Appl. Phys. Lett., 56, p. 656, 1990). A native oxide film on the surface of a Si substrate immersed in a diluted hydrofluoric acid solution dissolves to expose a bare Si surface, and hydrogen atoms terminate the dangling bonds at the Si substrate surface.
Although native oxide film removal using diluted hydrofluoric acid forms a stable Si substrate surface on the (1 1 1) plane, it forms a surface with a lower stability on the (1 0 0) plane. This wet process using diluted hydrofluoric acid presents some difficulties in proceeding directly to the next dry process because of a danger that the Si substrate surface may be again oxidized while the substrate is transported to the dry process system.
As another process of removing a native oxide film on a Si substrate, a dry process using hydrogen plasma is known (A. Kishimoto et al., Jpn. J. Appl. Phys., 29, p. 2273, 1990). This dry process of removing a native oxide film on a Si substrate can essentially and easily be followed by the next dry process. However, there is a danger that the Si substrate surface may be damaged because the Si substrate exposed in a plasma is impacted by collisions with high energy particles such as ions and electrons.
As still another process of removing a native oxide film on a Si substrate, a dry process using hydrogen atoms (radicals) is known (T. Takahagi et al., J. Appl. Phys., 68, p.2187, 1990). Although this dry process using hydrogen atoms (radicals) presents no danger of damage to the Si substrate surface, the process speed is low, and according to this paper, it takes time or the order of an hour to remove a native oxide film on a Si substrate surface.
As described above, it is not always easy to efficiently remove a native oxide film on a semiconductor substrate surface at any desired time during semiconductor device manufacturing processes.


A combination circuit formed of a functional portion circuit coupled to a latch or flip-flop circuit portion which is fabricated as a single gate on an integrated circuit semiconductor chip. The functional circuit portion can be a multiplexer, or other logic functions such as AND, NAND, OR, NOR, XOR, etc. A special buffer circuit is provided which generates a latch enable signal for the latch or a clock signal for the flip-flop in the combination circuit. The latch enable signal or the clock signal for the combination circuit has to override the high level values of the normal second level ECL signals while their low level values can be the same as those of normal second level ECL signals. This combination circuit has the advantage of higher speed, lower power consumption, and reduced component counts which is favorable for integrated circuits.

1. Field of the Invention
This invention relates generally to semiconductor circuits and more particularly, it relates to merging of a multiplexer circuit or other logic function circuits to a latch circuit or a flip-flop circuit which is formed as a single gate on an integrated circuit semiconductor chip for high speed operation.
2. Description of the Prior Art
In general, there are many circuit applications in which a multiplexer circuit or other logic function circuits such as AND, NAND, XOR, OR, NOR, etc., are required to be followed by a latch or flip-flop circuit. For example, the data input selected by a multiplexer circuit from different circuits are usually stored in a latch or flip-flop circuit. Typically, this is implemented by the use of two separate and distinct gate circuits. The two gates of the multiplexer circuit and latch circuit of the prior art as shown in FIG. 1(a) and 1(b) are then connected in cascade. These prior art circuits have the disadvantages of increased power consumption and increased number of circuit components and a lower operating speed due to the propagation time delay in using two separate gates.
It would thus be desirable to provide a combination multiplexer circuit or other logic function circuit and a latch or flip-flop circuit which are formed as a single gate on an integrated circuit semiconductor chip, thereby increasing the efficiency and speed of operation.

Merging of logic function circuits to ECL latch or flip-flop circuit


A solid-state imaging device includes a plurality of unit pixels. Each unit pixel has a photodiode, a reading transistor, a floating diffusion, a capacitance adding transistor, and a reset transistor. The reading transistor reads signal electric charges from the photodiode. The floating diffusion accumulates the signal electric charges read from the reading transistor. The capacitance adding transistor selectively adds capacitance to the floating diffusion. The reset transistor resets an electric potential of the floating diffusion.

1. Field of the Invention
The present invention relates to a solid-state imaging device, and more specifically relates to a circuit configuration of a unit pixel. The imaging device of the present invention is used, for example, to a CMOS image sensor.
2. Description of the Related Art
A plurality of unit pixels is arranged in an imaging area of the CMOS image sensor. Each unit pixel includes a photodiode, a floating diffusion, a reading transistor, an amplification transistor, a reset transistor, and a selection transistor. The photodiode photoelectrically converts incident light. The reading transistor performs reading of accumulated electric charges from the floating diffusion. The amplification transistor amplifies the signal of the floating diffusion to output the amplified signal to a vertical signal line. The reset transistor resets a gate electric potential (an electric potential of a floating diffusion). The selection transistor selects the unit pixels to control an operation of the amplification transistor.
In general, it is well known for the CMOS sensor that a thermal noise and 1/f noise are conspicuous. These noises are called a dark state random noise. To improve the dark state random noise, it is effective to raise a signal level of the floating diffusion in a preliminary step of an occurrence of the random noise. The voltage amplitude out(v) of the floating diffusion is given by an equation of out(v)=(e/CFD)×input(q). Here, "e" is an electric charge amount, CFD is capacitance of the floating diffusion, and input(q) is the number of signal electric charges. To enlarge the voltage amplitude of the floating diffusion and reduce the dark state random noises, it is effective to reduce the CFD of the capacitance of the floating diffusion. A conversion gain Gain of the unit pixel is given by an expression of Gain=Out(v)/input(q).
FIG. 1 shows a figure illustrating a reset operation and a reading operation in a case in which a signal electric charge amount accumulated in the photodiode PD is relatively small in a generic COMS sensor. That is, by turning on the reset transistor RST to perform a reset operation, the electric potential of the floating diffusion FD immediately after the reset operation is set to the same electric potential level as that of a drain. Next, when turning on the reading transistor RD, since a signal electric charge amount accumulated in the photodiode PD is relatively small, it is possible to transfer the signal electric charges to the floating diffusion FD even if the capacitance CFD of the floating diffusion FD is designed in a small size.
FIG. 2 shows a view illustrating a reset operation and a reading operation in a case in which the signal electric charge amount accumulated in the photodiode FD is relatively large in a generic CMOS sensor. That is, turning on the rest transistor RST to perform the reset operation allows the electric potential of the floating diffusion immediately after the reset operation to be set to the same electric potential level as that of the drain. When turning on the reading transistor RD at the next time, since the signal electric charges accumulated in the photodiode PD becomes an over amount, it is impossible to transfer all of the signal electric charges to the floating diffusion FD. A remnant Lag of the signal electric charges generates in the photodiode PD.
A technique adding gate capacitance to the floating diffusion in the unit pixel, which makes the capacitance of the floating diffusion variable, is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2000-165754. However, in this technique, even when tuning off the gate capacitance added for high sensitivity, parasite capacitance between the gate and the floating diffusion cannot be perfectly made zero. Thereby, in comparison with a case where the floating diffusion capacitance is not made variable, the floating diffusion capacitance increases, and the conversion gain decreases. As a result, a dark state random noise characteristic is deteriorated.
Meanwhile, a technique which increases the signal electric charge treatment amount by adding capacitance to a photodiode through a MOS transistor in a unit pixel is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2002-77737. However, in this technique, the reading transistor is not existed, and the photodiode and the newly added capacitance are connected to a gate of an amplification transistor. Thereby, a conversion gain is lowered. As a result, dark state random noise characteristics are deteriorated.
A technique increases a signal electric charge amount by adding capacitance to the photodiode through a MOS transistor is disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2006-245522. However, in this technique, in comparison with the conventional unit pixel, since it is needed to add circuit elements of total four of two transistors and two capacitors, shrink of the pixel size is made difficult.
As described above, in the conventional solid-state imaging device, the dark state random noise and the signal electric charge treatment amount are in a tradeoff (inconsistent) relationship, it is difficult to increase the signal electric charge treatment amount while maintaining the low noise in the dark, the improvement in this problem is desired.

Solid-state imaging device including a photodiode configured to photoelectrically convert incident light


Biometric sensing is performed by generating an input digital image of a human attribute; and correlating domains of lightness and darkness in the input digital image to domains of lightness and darkness in a reference digital image.

Biometric devices record fingerprints, faces, voices, irises, retinas, signatures and other physical attributes. The recorded attributes may be compared to reference data for authentication or identification purposes.
Biometric authentication involves comparing a recorded attribute to the reference data of a person who has already been identified. That person may have been identified by a smart card, a password, or some other piece of information. If the recorded attribute matches the reference data, the identify of the person is verified.
The uses for biometric authentication are quite varied. Biometric authentication devices may be used to verify attendance in the work place, control physical access to restricted areas, and verify the identities of parties to transactions.
Biometric authentication addresses the ever-increasing need for security on government and corporate networks, the Internet and public facilities. Biometric authentication offers advantages over conventional security measures such as passwords. Unlike passwords, biometric attributes are not easy to forget, and they are very difficult to duplicate.
Biometric identification involves comparing a recorded attribute to reference data for different people. If the recorded attribute matches the reference data of one of the people, a positive identification is made. Biometric identification devices can be used to pick out faces in crowds, control access to restricted areas, etc.
Many commercial biometric devices for performing face, iris, retinal and fingerprint scans are large, complicated and expensive.
A small compact, inexpensive, lightweight device would be highly desirable.

Hewlett-Packard Development Company, LP.


A portable inhalator device including a length of flexible tubing; a frictional engaging area on the outer surface of a first end of the tubing; and a second engaging area on the inner surface of the second end of the tubing, for releasably gripping the first end of the tubing and sealingly engaging therewith to form a closed loop.

Inhalators are used to introduce into the nasal passages a substance which is a fluid or may be borne by a fluid, e.g. powder. Typically such devices have a special fixture at one end to cooperate with the human nostril and another fixture at the other end to hold the substance to be inhaled, the inhalant. Alternatively, there may be provided at the nostril engaging end a space to hold the inhalant. Such apparatus tends to be large, cumbersome, and not very attractive or convenient to carry about or to use. In addition, very often the entire charge or dose of inhalant is not delivered. Some would be trapped where the flushing air could not reach to flush the powder. Further the delivery to the nostril is often a narrow stream which does not distribute the inhalant well.


The present invention discloses a method for culturing microorganisms having a methanol metabolic pathway in which an expression unit is introduced that comprises a target gene linked downstream from a promoter that can be induced by methanol; wherein, during the culturing period, and including the period during which methanol is continuously or periodically added, the rate of addition is adjusted to a rate equal to or less than the maximum methanol consumption rate of said microorganisms.

1. Field of Invention
The present invention relates to a method for culturing microorganisms having a methanol metabolic pathway into which has been introduced an expression unit in which a target gene is linked downstream to a promoter able to be induced by methanol, said method enabling the target gene product to be produced efficiently.
2. Related Art
The production of polypeptides and other gene products using microorganisms as hosts has basically become possible due to the advances made in recombinant DNA technology. Polypeptide production is performed by introducing an expression unit in which the gene for a target polypeptide is linked downstream to a suitable promoter. Microorganisms such as E. coli, yeasts and animal cells are typically used as a host.
Gene expression systems using E. coli as the host are the most commonly used systems, and these systems typically provide a high productivity. However, since there are many cases in which the expressed polypeptide forms insoluble inclusion bodies resulting in an insoluble form, the possibility of using this system is largely dependent on the properties of the target polypeptide.
On the other hand, gene expression systems that use animal cells as a host are useful for the purpose of confirming an activity of a gene product and so forth since in many cases the expressed polypeptide retains activity. However, the amount of target polypeptide is typically low, and considerable efforts are required for purification in this case. In addition, since animal cells reproduce slowly and the media used are expensive, culturing requires both considerable time and cost. Moreover, it is also difficult to increase the scale of culturing. Consequently, animal cells are not desirable as a host for industrially obtaining a target polypeptide in large volume.
Yeast cells are eucaryotic cells having endoplasmic reticulum, Golgi apparatus and other cellular components similar to animals cells. They are also known to be able to form and express polypeptides having particularly tertiary structures in polypeptides derived from eucaryotic cells. In addition, they reproduce faster than animal cells and can easily be cultured in large volume. Genetic analyses have been conducted most extensively on Saccharomyces cerevisiae, and it is widely used at the laboratory level as a host for gene expression.
However, since it is difficult to grow Saccharomyces cerevisiae to a high cell density and yield per culture medium is not high, it is not sufficient for industrial production of the target polypeptide. In order to solve this problem, methylotrophic yeasts such as Pichia pastoris, Hansenula polymorpha and Candida boidinii are used.
For example, Gellissen et al. succeeded in producing 1.4 g of glucoamylase at a cell density of 100 to 130 g dry cell weight per liter of culture medium using a formic dehydrogenase promoter for which expression is induced by methanol and Hansenula polymorpha as host (Gellissen et al. BIO/TECHNOLOGY, 9, 291-295, 1991). In addition, Barr et al. succeeded in producing 4 g of human serum albumin per liter of culture medium using an alcohol oxidase promoter for which expression is induced by methanol and Pichia pastoris as host (Barr et al. Pharm. Eng., 12(2), 48-51, 1992).
However, the problems described below are still possible even in the case of methods using methylotrophic yeasts. In the case of a yeast having a methanol metabolic pathway in a heterogeneous gene expression system using a yeast represented by the above-mentioned three species of methylotrophic yeasts and a promoter able to be induced by methanol, the methanol in the culture medium rapidly decreases when the yeast is cultured in a medium containing methanol. In this type of culturing, methanol must be supplied as a carbon source in order to simultaneously maintain transcription from the promoter and cell growth.
However, if the methanol concentration in the culture medium is suddenly increased during supply of methanol, the yeast may be killed. In addition, measurement of the methanol concentration in a culture of yeast having a methanol metabolic pathway is generally performed by applying the supernatant to gas chromatography and so forth. In this method, however, in addition to requiring special equipment, since a considerable amount of time is required until methanol concentration can be determined, it has the disadvantage of preventing a rapid judgment from being made regarding the need for replenishment of methanol.
As an example for a method for maintaining methanol concentration in a culture medium for expression of a target gene, a method is used that reduces the methanol consumption rate using a yeast in which the enzyme alcohol oxidase is missing from its metabolic pathway. This method involves growing yeast using glycerol and so forth as a carbon source, and then inducing transcription from a promoter by adding a fixed amount of methanol to the culture medium to express the target gene. Due to the low rate of methanol consumption, it is easy to maintain methanol concentration. Although it is possible to obtain a stable culture, this method has the disadvantage of requiring a long culturing time since culturing is performed separately for a cell growth period and a target gene expression period.
A method is disclosed in WO 95/21928 wherein the methanol concentration in a culture medium is controlled to a constant level in order to express a target gene by culturing a methylotrophic yeast, in which methanol metabolism has been slowed by partially altering enzymes of metabolic pathway, without increasing the number of cells. This method involves measuring a methanol concentration in the air inside the culture tank in a state in which a methanol concentration in the air inside the culture tank reflects the methanol concentration in the culture medium, and then determining the methanol addition rate from those results to control the methanol concentration in the culture medium.
The methanol concentration in a culture medium of methylotrophic yeast deficient for alcohol oxidase gene can be controlled to a constant level by applying this method. However, in order to predict the methanol concentration in the culture medium from the methanol concentration in the air inside the culture tank, it is necessary that both be at equilibrium. In order to achieve this equilibrium, culture conditions including aeration rate, pressure and temperature must be maintained constant, and the methanol concentration in the culture medium must not change suddenly. Due to these restrictions, the above-mentioned method for controlling methanol concentration could only be applied to culturing in the gene expression induction phase after the cells had been grown in advance using a yeast that does not have a methanol metabolic pathway.
On the other hand, in a heterogeneous gene expression system using a promoter capable of being induced with methanol and a microorganism having a methanol metabolic pathway as a host, it is not necessary to isolate the microorganism growth phase and the induction phase for gene expression if the rate of methanol addition and the concentration of methanol in the culture medium are suitably controlled. Consequently, culturing time is shortened which results in the target protein being able to be obtained in a short time. Thus, in the culturing of microorganisms having a methanol metabolic pathway, there is a need to establish a method for maintaining a suitable rate of methanol addition or methanol concentration that satisfies both the production of the target gene product and microorganism growth.

Method for culturing microorganisms having a methanol metabolic pathway


A power transmission device is used to distribute torque from a power source to an external device and an auxiliary device. The power transmission device is comprised of a first bearing and a second bearing both secured to a stationary member, a first sprocket rotatably supported by the first bearing, a second sprocket capable of being drivingly coupled with the auxiliary device, a chain coupling the first sprocket with the second sprocket, a rotary shaft rotatably supported by the second bearing, which is drivingly coupled with the power source and drivingly engageable with the external device to transmit a first part of the torque to the external device, and a joint drivingly linking the rotary shaft with the first sprocket to transmit a second part of the torque to the first sprocket.

1. Field of the Invention
The present invention relates to a power transmission device which is capable of distributing torque in part to an external device such as a gearbox and in part to an auxiliary device such as an oil pump.
2. Description of the Related Art
In an automobile, torque generated by an engine or an electric motor is transmitted to wheels via a power transmission. In certain cases, the automobile is equipped with an auxiliary device such as an oil pump and then sometimes uses a chain drive to distribute the torque in part to the auxiliary device to power the auxiliary device. Japanese Patent Unexamined Application Laid-open No. 2001-27316 discloses a related art.


Methods and devices described herein facilitate improved access of locations within the body by providing a variety of dissection modes on a single access device.

Methods and devices for access devices to allow improved manipulation of organs and/or instruments within the body by creating working spaces within the body and adjacent to a target site. The methods and devices can be used in various parts of the body. One particular application includes the use of the access devices and methods to advanced devices to a surface of the heart to create atrial lesion patterns one or more atrial surfaces of the heart.
Scope based surgical tools (e.g., elongated cannula/tubular devices that allow viewing of internal body tissues) provide surgeons with an ability to view a surgical site through a lens/fiber optic/camera of the scope and also provide an ability to access the surgical site through a working channel of the tool. In some cases, a scope permits the surgeon to access internal body tissue by passing the scope through a small diameter opening, port, or trocar placed in a surface of the body.
In many surgical procedures, the surgeon must also dissect tissue to gain access to the intended target site. For example, U.S. Pat. No. 5,205,816 (the entirety of which is incorporated by reference) teaches a simple blunt dissector having a cannulated single lumen device with a mandrel inserted into the device for carrying a simple textured cloth that provides a textured surface. However, such basic devices are used in addition to the scopes that are used for such minimally invasive procedures. The additional blunt dissector requires an additional entry port or must he exchanged with other tools that are advanced, through the entry site. In addition, a physician must manipulate a scope as well as the blunt dissection device.
Increasingly, scopes are being adapted to assist in the dissection of tissue to eliminate the need for an additional dissection device. Clearly, doing so reduces the number of devices that a physician must manipulate in the surgical area as well as the number of devices that are advanced through the body opening/port/incision. Many conventional devices rely upon balloon-type structures for dissection of tissue via expansion of the balloon or close-ended obturator-type structures that dissect via dilation via insertion of the closed end.
For example, U.S. Pat. No. 6,989,018 to Fogarty et al. (the entirety of which is incorporated by reference herein) discloses a balloon dissection apparatus having an elongate balloon that performs the tissue dissection. However, because this dissection relies upon somewhat uncontrollable expansion of the balloon (as the internal balloon pressure increases., the physician typically has less control over the amount of tissue dissection as compared to using a non-expanding, structure to physically dissect tissue.
While obturator type devices avoid the problems with somewhat unpredictable dissection via balloon expansion, such devices are still not optimal. For example, U.S. Pat. Nos. 6,592,604; 6,752,756; and 7,001,404 (the entirety of each patent incorporated by reference herein) describe tissue dissection devices having with closed ends (where such ends act as obturators). The closed ends are generally translucent to allow for visualization therethrough. Yet, dissection of tissue occurs via dilation of the tissue using the closed end. U.S. Pat. No. 7,300,448 (the entirety of which is incorporated by reference herein) discloses a combination balloon dissector having an obturator associated with the balloon dissector assembly.
In any event, the balloon dissection or dissection via obturator dilation as described above do not provide the physician with the ability to tease or loosen adjoining tissue for a more controlled dissection of tissue.
Another drawback with conventional devices is their failure to accommodate removal of debris that is generated by the tissue dissection process. Such debris interferes with visualization through the scope. For example, during tissue dissection the resultant blood often smears the visualization scope. Alternatively, tissue debris (e.g., fatty deposits, etc.) present at the surgical site adheres to the visualization element. Even bodily fluids and the inherent body temperature can combine to produce condensation over the visualization scope. Often, a separate irrigation source must flush the distal end of the scope to maintain proper visualization. For example, U.S. Pat. No. 6,176,825 (incorporated by reference herein) discloses a cannula based irrigation system having a separate moveable irrigation member within the device.
Without the ability to irrigate the scope, a physician will be forced to repeatedly remove the scope from the surgical site and body for Cleaning. Removal and cleaning of the scope increases the length and therefore the risk associated with the surgical procedure. Moreover, apart from the debris, in the obturator-type devices described above, the closed transparent end of the device often causes a distorted view of the working area.
Atrial fibrillation surgery is one example of a surgical procedure that relies upon dissection of tissue to access the target tissue site. To access the fibrillation surgery site, a physician typically dissects through tissue under direct visualization using an endoscope. Preferably, once the physician reaches the target site, the physician will establish a working Channel or access path to the target site for the advancement of various surgical devices.
Accordingly, there remains a need for improved access devices that are configured to aid a physician during dissection of various tissues to access a target tissue site by providing the ability to gently dissect as well as establish space required to perform the intended procedure. The improved methods and devices described herein offer improved access to tissue regions within the body, especially those organs in the thoracic cavity. However, the devices and methods have applicability to any region in the body apart from the thoracic cavity.
For convenience, the following disclosure makes reference an endoscope as the scope based device. However, the inventive devices and methods described herein specifically include the use of any number of scope based devices generally similar to an endoscope; for example, any type of rigid or flexible tube with a light delivery system and a visualization source that transmits an image to the viewer, and (optionally) a working channel or lumen that permits delivery of an additional device through the scope.

Dissecting cannula and methods of use thereof