A method for painting a complex or compound curved three-dimensional surface of a portion of an article. The method comprises providing a paint film (24); providing sheet metal (26) having opposite major surfaces; laminating the paint film onto a major surface of the sheet metal to form a painted sheet metal laminate (22) comprising a first portion and a second portion; permanently deforming the first portion of the painted sheet metal laminate into a formed portion of the article having a complex or compound curved three-dimensional shape; applying an initial force for securing the second portion of the painted sheet metal laminate during an initial stage of said permanently deforming step; and applying a later force for securing the second portion of the painted sheet metal laminate during a later stage of said permanently deforming step. The later applied force is greater than the initially applied force.

Several paint replacement films, or dry paint films, are commercially available for replacing liquid painting in automotive applications. These paint films are typically die-cut and incorporated on the structure of the automobile as appliqués. Such paint films include those disclosed in U.S. Pat. No. 5,759,477, assigned to Green Tokai Co. Ltd., Method of Making Film Plastic Parts; U.S. Pat. No. 7,833,380 B2, assigned to Laminate Products, Inc., Decorative System Composite and Method; U.S. Pat. No. 7,853,454 B2, assigned to Laminate Products, Inc., Method of Producing a Paint Film Part; U.S. Pat. No. 6,090,336, assigned to Decoma International Inc., Method for Manufacturing an Injection Molded Article with Outer Film Secured Thereto; and Plastics Technology January 2004: Where the Action is: Decorating with Formable Films, by Lilli Manolis Sherman. All of these US patents are incorporated herein by reference in their entirety.
The research activities on polymer coated metals predominantly focus on corrosion protection or corrosive delamination. In view of the inherent mismatch in properties between the polymer films and the metal, far less attention is given to the industrial forming of coated metals by means such as, for example, deep-drawing. Published papers deal with the loss of adhesion and recovery of polymer coated steel and laminated steel sheets sandwiched with a polymer core; however, there is virtually no history for the use of paint film laminated sheet metal in automotive stamping processes to produce complex three dimensional parts.
The author of Plastics Technology January 2004: Where the Action is: Decorating with Formable Films, L. Sherman, describes the advancements in the area of in-mold decorating (IMD) with paint films. This reference focuses on the production of film laminated plastic parts. The article quotes the industry manger at GE Plastics: "Paint line is the biggest investment in an auto assembly plant; it occupies half the plant floor space; and it can generate over 1500 tons a year of VOC's" (volatile organic chemicals).
The authors (page 477) of Journal of Materials Processing Technology 46 (1994) 455: Recent trends in sheet metals and their formability in manufacturing automotive panels, describe the need for development of forming techniques to overcome wrinkling and the deterioration of the appearance of the finished parts, and to increase the formable range. But they do not provide any solutions for satisfying this need.
The authors of Journal of Materials Processing Technology 151 (2004) 133-140: Wrinkling behavior of laminated steel sheets, disclose laminates created from a polymer core and sheets of metal on both sides of the polymer. The authors describe the behavior differences, as compared to homogeneous steel sheets, due to the significant differences in material properties of the steel and polymer.
The authors of Journal of Engineering Materials and Technology October 2007, Vol. 129, page 530: The Influence of Temperature on the Forming Behavior of Metal/Polymer Laminates in Sheet Metal Forming, describe the forming behavior of metal-polymer laminates for which a polymer is sandwiched between layers of metal. Although the constructions offer benefits in terms of weight reduction and vibration damping, when compared to the results for homogeneous metals the constructions are inferior in terms of the tendency to wrinkle.
The authors of Journal of Materials Processing Technology 209 (2009) 297-302: On the prediction of delamination during deep-drawing of polymer coated metal sheet, highlight the value of forming polymer coated sheet metal: decrease the subsequent steps of coating, increase cost savings, and eliminate VOC emissions. They further describe that deep-drawing produces large plastic strain. This strain produces rough surfaces and loss of adhesion, which may further result in delamination. They do not provide any solutions to these problems.
U.S. Pat. No. 4,225,553, assigned to Toyo Seikan Kaisha, Limited, discloses a method of manufacturing low-rigid, wrinkle free articles. The laminate construction cannot be more than 200 microns in thickness and consists of a thermoplastic resin film, aluminum foil, and a heat-sealable resin film. Drawing of this laminate is performed through cold-drawing—without a heating step.
U.S. Pat. No. 5,093,208, assigned to CMB Food can plc, discloses a process for laminating a metal sheet with a non-crystalline polyester film. The construction is useful for drawing into cans.
U.S. Pat. No. 6,699,566 B2, assigned to Alcan Technology and Management Ltd., discloses a process for manufacturing shaped packaging. Cold drawing is used in the process. The claims limit the thickness of the metal layer to 8-150 microns and the thickness of the plastic layer to 12-120 microns.

Method of forming deep-drawn paint film laminated sheet metal and articles made therefrom


A magnetic recording medium has a substrate made of a nonmetal nonmagnetic material whose coefficient of linear expansion lies within a range from 0.000013/deg to 0.0001/deg. A magnetic layer is formed on the substrate as a thin polycrystalline film or a thin amorphous film. The magnetic layer has Co as a main component, which exhibits a negative magnetostrictive constant so that its coercive force rises in the direction of compressive strain. The magnetic layer is subjected to an in-plane compressive strain from the substrate due to a difference between the coefficient of thermal expansion of the substrate and the magnetic layer so that high coercivity is obtained in the magnetic layer.

The invention relates to a magnetic recording medium which is used in a magnetic memory apparatus such as rigid type magnetic disk apparatus, drum type memory apparatus, card type magnetic memory apparatus, or the like and, more particularly, to a magnetic recording medium having a high shock resistance and a high coercive force.
In recent years, in association with an increase in information amount, not only a large capacity is more and more being required in a magnetic memory apparatus but also the desire for miniaturization is increasing. In many cases, since the miniaturized magnetic memory apparatus is installed in a portable computer or the like, it is necessary to have a high shock resistance such that the magnetic memory apparatus is not broken by mechanical shock caused by dropping it or the like. To accomplish such a requirement, for example, according to JP-A-49-122707, there has been proposed a method or the like whereby in place of an Al alloy substrate plated with NiP, a nonmetal nonmagnetic substrate having a higher yield strength such as tempered glass, crystallized glass, ceramics, amorphous carbon, monocrystalline silicon, surface oxidized monocrystalline silicon, or the like is used as a substrate of the magnetic recording medium.


RFID reader systems, components, software and methods are provided for use premises that have RFID-tagged items. When a person comes onto an enclosure of the premises already carrying a personal tag, the incoming code of that personal tag is read. When later the person exits the enclosure, they could be transporting some of the items that have actionable codes. The actionable codes can be read, but the incoming code can be removed from them, before the actionable codes are acted upon, in Point-of-Sale or Electronic Article Surveillance systems.

Radio Frequency IDentification (RFID) systems typically include RFID tags and RFID readers. RFID readers are also known as RFID reader/writers or RFID interrogators. RFID systems can be used in many ways for locating and identifying objects to which the tags are attached. RFID systems are particularly useful in product-related and service-related industries for tracking large numbers of objects being processed, inventoried, or handled. In such cases, an RFID tag is usually attached to an individual item, or to its package.
In principle, RFID techniques entail using an RFID reader to interrogate one or more RFID tags. The reader transmitting a Radio Frequency (RF) wave performs the interrogation. The RF wave is typically electromagnetic, at least in the far field. The RF wave can also be magnetic in the near field.
A tag that senses the interrogating RF wave responds by transmitting back another RF wave. The tag generates the transmitted back RF wave either originally, or by reflecting back a portion of the interrogating RF wave in a process known as backscatter. Backscatter may take place in a number of ways.
The reflected-back RF wave may further encode data stored internally in the tag, such as a number. The response is demodulated and decoded by the reader, which thereby identifies, counts, or otherwise interacts with the associated item. The decoded data can denote a serial number, a price, a date, a destination, other attribute(s), any combination of attributes, and so on.
An RFID tag typically includes an antenna system, a radio section, a power management section, and frequently a logical section, a memory, or both. In earlier RFID tags, the power management section included an energy storage device, such as a battery. RFID tags with an energy storage device are known as active or semi-active tags. Advances in semiconductor technology have miniaturized the electronics so much that an RFID tag can be powered solely by the RF signal it receives. Such RFID tags do not include an energy storage device, and are called passive tags.
It has been suggested that UHF RFID technology be used for tracking items within premises. Such premises include warehouses, stores, and other places where goods are handled. In particular, as further explained with reference to FIG. 6 of this document, it has been suggested that items can be tagged with RFID tags, and there can be RFID readers to read these tags. Upon so reading, the RFID readers can monitor the position of the tags, and therefore of the items, within the premises, or as they exit the premises. Such would substantially improve the internal operations of the premises, reducing operational costs, and resulting in savings that can be passed on to eventual consumers of the goods.
A problem arises upon recognizing that RFID readers installed at premises will be able to also read, in addition to tags of the items, tags that are foreign to the RFID environment of the premises. Such foreign tags are tags that may be carried by persons that come onto the premises for legitimate reasons, and can also be called personal tags. Such personal tags may have different functions. In some of the functions, such foreign tags can be unrelated to the operation of the premises, and yet such RFID readers at the premises could still be able to read the personal codes of these personal tags. This can confuse RFID-based Point-Of-Sale (POS) systems and Electronic Article Surveillance (EAS) systems.

Reading codes of RFID tags incoming at premises and removing them later as they exit


Task assignments are identified. A dataset that includes one or more electronic messages is received. Then, one or more pending tasks in the dataset are identified, and each of a plurality of people who are mentioned in the dataset is also identified. Then, for each of the pending tasks, one or more of the identified people are identified as potentially being people who are assigned to complete the pending task, and the pending task is associated with these identified one or more of the identified people. For each of the pending tasks, one or more of the identified people are also identified as potentially being people for whom the pending task is to be completed, and the pending task is also associated with these identified one or more of the identified people.

The Internet is a global data communications system that serves billions of people across the globe and provides them access to a vast array of online information resources and services including those provided by the World Wide Web and intranet-based enterprises. Thanks to the ubiquity of the Internet and the wide variety of network-enabled end-user computing devices that exist today, people today spend a large and ever-increasing amount of time online. People today also heavily rely on electronic messages to communicate with each other in both a professional and a personal context. In other words, people today frequently have conversations by sending and receiving electronic messages over a data communication network.
Successful communication between people is paramount to their well-being and success. For example, successful communication between the members of an organization and its clients is paramount to the well-being and success of the organization as well as its members and clients. In the course of such communication tasks are often assigned to people. Failure to appropriately complete the assigned tasks in a timely fashion can negatively impact the well-being of the people who were assigned to complete the tasks as well as the people for whom the tasks are being completed. In the case where these people are members of an organization, failure to complete the assigned tasks may also negatively impact the well-being of the organization and its clients. This also applies to people's personal lives and their communication with family and friends.


A spectroscopic microscope according to the present embodiment includes a light source that generates laser light that enters a sample, a multi-slit part having a plurality of slits through which signal light branched by the edge filter passes, the slits being arranged in the slit width direction, and a spectrometer that disperses the signal light having passed through the slits in the dispersion direction intersecting the slit length direction and detects the signal light with a two-dimensional array photodetector.

As an observation method of the fine structure of an object to be observed, Raman spectroscopic microscopes are known. Raman spectroscopic microscopes are widely used in many fields, such as materials engineering, medical diagnosis, and drug discovery, since they can acquire spatial distribution while measuring the frequency of a molecule or crystal lattice vibration.
Non Patent Literature 1 discloses a Raman microscope including a spectrometer for measuring a Raman spectrum. In the Raman microscope disclosed in Non Patent Literature 1, a micro lens array that generates a beam array is arranged in the optical path of laser light. A sample is illuminated with an 8×8 beam array generated by the micro lens array. Then, the Raman scattering light enters an 8×8 fiber bundle.
The fiber bundle is arranged to be 1×64 at an entrance slit of the spectrometer. That is, 64 fibers are arranged in a line at the emission end of the fiber bundle. Then, the Raman scattering light emitted from the fiber bundle is spatially dispersed by wavelength by the spectrometer and detected by a CCD camera. Thus, two-dimensional spatial information and one-dimensional spectrum information are converted into two-dimensional array information on the light-receiving surface of the CCD camera and detected. The spectrum of the Raman scattering light generated at multiple points of the sample can be simultaneously measured.

Spectroscopic microscope and spectroscopic observation method


A process of determining whether a patient with a disease or disorder will be responsive to a drug, used to treat the disease or disorder, including obtaining a test spectrum produced by a mass spectrometer from a serum produced from the patient. The test spectrum may be processed to determine a relation to a group of class labeled spectra produced from respective serum from other patients having the or similar clinical stage same disease or disorder and known to have responded or not responded to the drug. Based on the relation of the test spectrum to the group of class labeled spectra, a determination may be made as to whether the patient will be responsive to the drug.

The inventors of the instant invention have found a novel method of determining if a patient will respond to a treatment by testing the patient's biomarkers by mass spectroscopy. As an example of one embodiment of this invention, the inventors have applied their technique to a cancer, Non-Small-Cell Lung Cancer (NSCLC).
Non-Small-Cell Lung Cancer is a leading cause of death from cancer in both men and women in the United States. There are at least four (4) distinct types of NSCLC, including adenocarcinoma, squamous cell, large cell, and bronchoaldeolar carcinoma. Squamous cell (epidermoid) carcinoma of the lung is a microscopic type of cancer most frequently related to smoking. Adenocarcinoma of the lung accounts for over 50% of all lung cancer cases in the U.S. This cancer is more common in women and is still the most frequent type seen in non-smokers. Large cell carcinoma, especially those with neuroendocrine features, is commonly associated with spread of tumors to the brain. When NSCLC enters the blood stream, it can spread to distant sites such as the liver, bones, brain, and other places in the lung.
Treatment of NSCLC has been relatively poor over the years. Chemotherapy, the mainstay treatment of advanced cancers, is only marginally effective, with the exception of localized cancers. While surgery is the most potentially curative therapeutic option for NSCLC, it is not always possible depending on the stage of the cancer.
Recent approaches for developing anti-cancer drugs to treat the NSCLC patient focus on reducing or eliminating the ability for cancer cells to grow and divide. These anti-cancer drugs are used to disrupt the signals to the cells to tell them whether to grow or die. Normally, cell growth is tightly controlled by the signals that the cells receive. In cancer, however, this signaling goes wrong and the cells continue to grow and divide in an uncontrollable fashion, thereby forming a tumor. One of these signaling pathways begins when a chemical in the body, called epidermal growth factor, binds to a receptor that is find on the surface of many cells in the body. The receptor, known as the epidermal growth factor receptor (EGFR) sends signals to the cells, through the activation of an enzyme called tyrosine kinase (TK) that is found within the cells. The signals are use to notify cells to grow and divide.
Two anti-cancer drugs that were developed and prescribed to the NSCLC patients are called gefitinib (trade name "Iressa") and erlotinib (trade name "Tarceva"). These anti-cancer drugs target the EGFR pathway and have shown promise in being effective toward treating NSCLC cancer. Iressa inhibits the enzyme tyrosine kinase that is present in lung cancer cells, as well as other cancers in normal tissues, and that appears to be important to the growth of cancer cells. Iressa has been used as a single agent of the treatment of NSCLC that has progressed after, or failed to respond to, two other types of chemotherapies.
However, response rates have only been between 10% and 20% in Caucasian populations, and have led the Federal Drug Administration (FDA) in 1995 to withdraw support for the application of Iressa as a second-line treatment. Surprisingly, the response rate in Asia has been considerably higher and Iressa is stilled used. Traceva is still approved and routinely given to patients, but still has response rate concerns. While it appears that Iressa and Traceva have the ability to be effective in some patients, they may not be generic drugs effective in treating all patients. There may be many factors involved in a patient's ability to respond to these drugs that are currently unknown. However, if a determination of factors that could be used to predict the effectiveness of a NSCLC patient to respond to these anti-cancer drugs, the FDA could allow these anti-cancer drugs to be prescribed to those patients having conditions that indicate that they would be responsive to these drugs. Doctors could then prescribe these drugs to those patients predicted to respond to the anti-cancer drugs with the knowledge that their patients would be responsive to the treatments.

Method and system for determining whether a drug will be effective on a patient with a disease


A laser arrangement for generating a twice frequency-converted laser radiation is disclosed, comprising the following: an active medium which by radiation of pump light generates a first laser radiation with a first frequency; a first laser resonator inside of which the first laser radiation circulates while resonating; a first non-linear crystal which is arranged inside of the first laser resonator and is provided and established to convert the first laser radiation into a second laser radiation with a second frequency that is higher than the first frequency; a second laser resonator inside of which the second laser radiation circulates while resonating; a second non-linear crystal which is arranged inside of the second laser resonator and is provided and established to convert the second laser radiation into a third laser radiation with a third frequency that is higher than the second frequency, wherein the first laser resonator and the second laser resonator are arranged relative to each other such that they have a joint optical section through which both the first laser radiation, circulating in the first laser resonator, and the second laser radiation, circulating in the second laser resonator, radiate. The first laser resonator and the active medium are designed and arranged such that the first laser radiation consists of precisely two adjacent longitudinal modes with two frequencies, wherein the first frequency of the first laser radiation is a sum frequency of these two frequencies, and in that the second laser resonator has an optical path length which allows for a resonance of merely a single longitudinal mode of the second laser radiation.

The present invention relates in an aspect to a laser arrangement for generating a twice frequency-converted laser radiation.
Such a laser arrangement is particularly suitable for generating a single-frequency, low-noise laser light with a wavelength in the UV range.
Numerous lasers with a frequency conversion inside of a resonator are known from prior art, which are employed to generate laser light with a wavelength in the UV range. The frequency conversion inside of a resonator here serves to increase the frequency of the initially generated laser light in order to generate, proceeding from longer-wave laser light, short-wave laser light with a wavelength in the UV range.
From DE 103 39 210 A1 a laser arrangement is known, in which altogether three laser resonators, arranged one after the other, are provided in order to obtain twice frequency-converted laser light. The first laser resonator serves for generating a fundamental wave, the second laser resonator for generating the second harmonic (first overtone) and the third laser resonator for generating the fourth harmonic (third overtone). The individual resonators must be coupled with a complex optics in order to enable an efficient transition of the laser light to be converted from one resonator to the next resonator.
From U.S. Pat. No. 5,621,744 A a laser arrangement is known, having a first frequency conversion stage inside of a resonator and an external second frequency conversion stage. The external second frequency conversion stage is here designed as a circular laser resonator. In such an arrangement, also, a comparatively complex optics is necessary in order to ensure a correct coupling of the laser radiation into the second frequency conversion stage.
From DE 42 28 862 A1 a laser arrangement is known, in which two laser resonators are coupled with each other and in which the laser light circulating in the two resonators partially radiates through a joint section of both resonators. The drawback of this arrangement is the use of a so-called multimode laser, which emits multi-frequency laser light, has a small coherence length and, moreover, has undesirable amplitude noise in the generated laser light.
From DE 101 18 793 A1 a laser arrangement is known, in which two non-linear crystals are arranged in a joint resonator in order to in this manner attain a two-fold frequency conversion of the laser light radiated into it. By refraining from the use of a further laser resonator, this arrangement can be designed in an optically less complex manner. However, the drawback is that the efficiency of the arrangement is low if only one frequency circulates in the laser resonator while resonating. If in the arrangement all the generated frequencies are made resonant, then undesirable amplitude noise can likewise occur in the emitted laser radiation.

Laser arrangement for generating a twice frequency converted laser radiation


Signal processing apparatus comprises a control read only memory storing:. (i) two or more sets of signal processing parameter data to control signal processing operations of the apparatus; and PA1 (ii) configuration data specifying one of the sets of signal processing parameter data stored in the control read only memory; PA1 a control read/write memory capable of storing: PA1 (i) at least one set of signal processing parameter data; and PA1 (ii) configuration data capable of specifying a set of signal processing parameter data stored in the control read only memory or a set of signal processing parameter data stored in the control read/write memory;. and control logic, responsive to an input selection signal specifying whether the configuration data in the control read only memory or the configuration data in the read/write memory should be selected for use, for controlling the signal processing apparatus to perform signal processing operations in accordance with the signal processing parameter data specified by the selected configuration data.

1. Field of the Invention
This invention relates to controlling signal processing.
2. Description of the Prior Art
It is common for signal processing apparatus to be operable in a number of signal processing modes. An example of such an apparatus is a video down-converter which can receive an input video signal in, say, an 1125 line or a 1250 line high definition video format and generate an output video signal in, say, a 525 or a 625 line conventional definition format. The various possible modes of operation, in addition to the simple choice of line format, might include a selection between a horizontal line cropping mode and a horizontal spatial compression mode to cope with the different aspect ratios of the input and output signals, and a selection between a full screen and a "letterbox" mode for the output video signal.
Accordingly, an apparatus of this type can have many different modes of operation, possibly with a normal or default mode applying if no other mode is positively selected.
In the case of a signal processing apparatus of the type described above, it is then necessary to ensure that the appropriate signal processing coefficients (e.g. filter coefficients and various other signal processing parameters) are passed to signal processing devices within the apparatus.

Multiple mode controlling signal processing apparatus


A toll call service center of the present invention is accessible by subscribers to a toll call service. One or more of the subscribers of the service have their own set of identifiers uniquely associated with a plurality of called stations desired to be accessed by the subscriber. The center comprises a voice command system having a storage for storing representations of the identifiers at storage locations uniquely identified with the subscriber. The command system also includes an announcing circuit and a processor operative under the control of a program stored therein. The processor is responsive to reception of an incoming call from a subscriber for controlling the announcing circuit to request the subscriber to speak an identifier associated with one of the plurality of called stations. A voice recognizer is responsive to receipt of the identifier for determining whether the identifier is valid. If the identifier is recognized as belonging to the subscriber, the processor controls an outdialer to dial the telephone number of the called station associated with the identifier.

Telephone "calling" cards are well-known in the prior art. Such cards typically include a memory comprising a magnetic tape or other storage media affixed to the card. Data in this storage media typically identifies the card number and the account to which the card has been assigned, and it may also comprise an authorized user's personal identification number or "PIN." To effect a toll call, the card is inserted into a cardreader (or the bearer is prompted to enter the card data via the telephone keypad) and relevant information is read from the card for subsequent billing.
Some cards include a data processing capability in the form of a microprocessor and an associated control program. Such "smart" cards have been used in prior art voice command systems wherein it is important to limit access to certain services to only authorized users. For example, U.S. Pat. No. 4,827,518 to Feustel et al describes a speaker verification and voice command system wherein speech templates are stored in the card. To verify the user's identity, a comparison is made between a plurality of reference speech templates stored in the card and a test template formed from a word or words spoken by the user at a transaction terminal. A similar system is described in U.S Pat. No. 3,896,266 to Waterbury.
Such prior art systems are effective but are significantly complex and somewhat expensive. They require the use of specialized hardware to generate and store the coded information on the cards, as well as the use of precise verification algorithms to discriminate the voice of an authorized user from all unauthorized users. Moreover, prior art voice verification schemes do not always work effectively over the telephone network. Generally, this is because the telephone network is a challenging environment that degrades the quality of speech through the introduction of various types of noise and band-limitations. Such economic and technological limitations have in large part prevented voice command calling systems from being commercialized.
There is thus a need for methods and systems that overcome these and other problems associated with the prior art.


A zoom lens includes sequentially from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a negative refractive power. The zoom lens varies the interval between the lens groups to perform zooming; shifts the second lens group in a direction substantially orthogonal to the optical axis to correct image blur occurring with optical system vibrations; and satisfies given conditions, enabling a compact size and a high zoom ratio to be achieved while improving imaging performance.

1. Field of the Invention
The present invention is related to a compact zoom lens that achieves wide angles, has a high zoom ratio, and is suitable for digital imaging apparatuses such as digital still cameras and digital video cameras.
2. Description of the Related Art
Reductions in the size of digital imaging apparatuses such as digital still cameras, broadcast cameras, and surveillance cameras have advanced. Accordingly, zoom lenses that are compact and, have a high zoom ratio and high imaging performance are demanded as imaging optical systems for use on such digital imaging apparatuses.
To address such demands, several zoom lenses are known that sequentially include from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power that is followed by 1 or more lens groups (see, for example, Japanese Patent Application Laid-Open Publication Nos. 2011-33868, 2012-98699, and 2009-282398).
The zoom lens recited in Japanese Patent Application Laid-Open Publication No. 2011-33868 has a zoom ratio on the order of 9 to 41.2, and an angle of view at the wide angle edge on the order of 68.4 to 79.6 degrees. The zoom lens recited in Japanese Patent Application Laid-Open Publication No. 2012-98699 has a zoom ratio on the order of 33.5 to 44.25, and an angle of view at the wide angle edge on the order of 74 to 84 degrees. The zoom lens recited in Japanese Patent Application Laid-Open Publication No. 2009-282398 has a zoom ratio on the order of 9.7 to 19.4, and an angle of view at the wide angle edge on the order of 74 to 84 degrees.
Although the zoom lenses disclosed in Japanese Patent Application Laid-Open Publication Nos. 2011-33868 and 2012-98699 have a sufficiently large angle of view at the wide angle edge and a sufficiently large zoom ratio, the maximum image height at the wide angle edge cannot be said to be sufficiently large and high imaging performance cannot be achieved. If the image height at the wide angle edge is increased, the diameter of the optical system has to be increased. However, if the diameter of the optical system is increased, the overall length of the optical system accordingly increases. In either case, a compact size for the optical system cannot be maintained, making use on a compact imaging apparatus difficult.
Further, the zoom lens disclosed in Japanese Patent Application Laid-Open Publication No. 2009-282398 corrects image blur by moving the third lens group in a direction orthogonal to the optical axis. Nonetheless, in the zoom lens, the anti-shake coefficient (amount that image shifts/amount that anti-shake group is shifted) of the third lens group at the telephoto edge decreases and therefore, the distance that the third lens group is moved to prevent blurring at the telephoto edge increases. As a result, the imaging performance when blur is corrected deteriorates. Further, a large area for the third lens group to move has to be established, inviting increases in the size of the optical system. In addition, the mechanism for driving the third lens group also has to be of a larger size.
Since the zoom ratio of the zoom lens disclosed in Japanese Patent Application Laid-Open Publication No. 2009-282398 is on the order of 9.7 to 19.4, compared to that of the zoom lenses disclosed in Japanese Patent Application Laid-Open Publication Nos. 2011-33868 and 2012-98699, the zoom ratio is insufficient. However, if the zoom ratio is increased, the distance that the lens group for zooming moves increases and the overall length of the optical system increases, which hinders attempts to reduce the size of the optical system.


A sequence in which two or more of the data units enter the network node, via a specific one of the multiple ports, is recorded. And, the two or more of the data units are transmitted from the network node according to the recorded sequence. The method and system achieve the recording of sequence via the following. In response to an insertion of one of the two or more data units into a specific one of the multiple processor subsystems, the specific one of the multiple processor subsystems is associated with a specific one of the multiple ports by which the one of the two or more data units entered the network node, and any other of the multiple processor subsystems that are currently processing on any other of the two or more data units that entered the network node through the specific one of the multiple ports is noted. Thereafter, any request to transmit by the specific one of the multiple processors is honored if it is determined that the data unit with the requesting processor is next according to the recorded sequence. The data unit is determined to be next in sequence if all of the multiple processors, that were processing on other data units which entered through the specific one of the multiple ports, have completed processing.

1. Technical Field:
The present invention is related to a method and system to be utilized in data communications. In particular, the present invention is related to a method and system to be utilized in data communications involving at least one data communications network. Yet still more particularly, the present invention is related to a method and system, to be utilized in data communications involving at least one data communications network having at least one multiprocessor network node.
2. Description of the Related Art:
Data communications is the transfer of data from one or more data sources to one or more data sinks that is accomplished (a) via one or more data links between the one or more sources and one or more sinks, and (b) according to a protocol. Weik, Communications Standard Dictionary 203 (3 ed. 1996). A data link is the means of connecting facilities or equipment at one location to facilities or equipment at another location for the purpose of receiving the data. Weik, Communications Standard Dictionary 206 (3 ed. 1996). A protocol, in communications, computer, data processing, and control systems, is a set of formal conventions that govern the format and control the interactions between two communicating functional elements in order to achieve efficient and understandable communications. Weik, Communications Standard Dictionary 770 (3 ed. 1996).
A data communications network is the interconnection of three or more communicating entities (e.g., data sources and/or sinks) over one or more data links. Weik, Communications Standard Dictionary 618 (3 ed. 1996). The branch of science and technology that is devoted to the study and analyses of the configurations and properties of networks makes use of what are known as network topologies. Weik, Communications Standard Dictionary 622 (3 ed. 1996). A network topology is typically a graphical representation of the specific logical arrangement, from a communications standpoint, of elements in a network, irrespective of such network elements' actual physical connection. In the art and science of network topology, different networks are distinguished by their different network topologies.
In network topology, each communicating entity in a network is depicted as a graphical point, or node. These nodes are abstract representations of locations in an actual physical network at which one or more data transmission lines are interconnected. Weik, Communications Standard Dictionary 622 (3 ed. 1996).
There are multitudinous known network topologies (e.g. mesh, star, fully connected, etc., and hybrids of such known network topologies). One such well-known network topology is the star network topology, which can be utilized to illustrate a problem that exists generally in the field of data communications involving networks having nodes.
A star network topology is a radial (starlike) configuration of communications network nodes such that (a) each endpoint node is connected via a single branch directly to the central node that serves as a central distribution node, and (b) each endpoint node can communicate with any other node only via the central node and two branches. The central node serves as a distribution node to all the endpoint nodes, including the originating node, or to selected endpoint nodes, depending upon whether the central node is an active or passive node. Weik, Communications Standard Dictionary 625 (3 ed. 1996).
FIG. 1 illustrates a star network topology. Shown is central node 100. Connected to central node 100 are endpoint nodes 102-116. These endpoints, or end stations, are connected to central node 100 via data links 122-136, respectively. The topology of the network makes clear that all communications between endpoints must transit central node 100.
In operation, central node 100 receives packetized data (in its most generic sense packetized data typically consists of a message field, a source field indicating the source node of the packetized data, and a destination field indicating the destination node (or data sink) of the packetized data) from endpoint nodes 102-116 over their respective data links. Upon reception of such packetized data, central node 100 reads the destination field, determines which data link the packetized data must be sent over to reach the destination indicated in the destination field, and then subsequently sends the packetized data over the appropriate data link. Central node 100 must do the foregoing (receive the packetized data, read the destination field, and then transmit the packetized data over the appropriate link) for each unit of packetized data received.
It is common for several end stations to desire to communicate with other end stations virtually simultaneously. In such situations, central node 100 is called upon to read the destination fields of several different units of packetized data, and forward the packetized data unit to the appropriate destination endpoint node, all at essentially the same time.
In old-style nodes performing the function of central node 100, this function was achieved by buffering (placing in temporary storage) one or more of the packetized data units, and then processing the stored data units one at a time. Another way to state this is that the packetized data units arriving virtually simultaneously were enqueued (made to wait in line) and would only be processed (i.e., destination field read and the packets forwarded to the appropriate destination) after the packetized data units ahead of them in the queue had been processed.
This need for enqueuing arose from the fact that in old-style nodes there was only one processor (or "thinker"), and that processor could only process one packetized data unit at a time. Thus, if more than one packetized data unit appeared at central node 100 virtually simultaneously, many of such packetized data units would have to "wait their turn" until the processor was able to process them.
As network data traffic increased, it was found that such enqueuing began to result in unreasonable communication delays (i.e., the wait in line, or in the "queue," became too long for the communications needs of particular endpoint nodes to be satisfied). This excessive delay problem was alleviated by placing multiple processors in central node 100.
Placing multiple processors (or "thinkers") in central node 100, essentially gave central node 100 the ability to simultaneously process as many packetized data units as there were processors. For example, if endpoint nodes 102, 104, and 106 transmitted packetized data destined for endpoint nodes 108, 110, and 112, respectively, to central node 100 virtually simultaneously, in the old-style nodes the packetized data arriving first at central node 100 would have been read and forwarded, while the two later arrivals would have been enqueued and made to wait their turn until the single central node 100 processor was ready for them.
In the new-style nodes, if central node 100 has at least three processors, and those processors are not engaged in processing other data, the three packetized data units will be handed over to the individual processors for processing almost immediately upon reception. That is, the multiple processors in central node 100 have alleviated the wait associated with the enqueuing. Subsequent to the multiple processors within central node 100 determining where the packetized data is to go (i.e., reading the destination information), the packetized data is transmitted over the appropriate data link associated with the destination station.
While the new-style nodes incorporating multiple processors have greatly improved communications efficiency, they have also inadvertently given rise to an attendant problem. That problem is the inability to ensure that the sequence of packetized data units entering the central node on one specific data link will be preserved upon those same packetized data units exiting the central node on another specific data link (notice that old-style nodes preserved such sequence merely as a byproduct of the enqueuing). This problem can be illustrated with reference again to FIG. 1.
This problem can be illustrated with reference again to FIG. 1. Assume the endpoint node 104 transmits four packetized data units in sequence to be delivered to endpoint node 116. Assume also that central node 100 has at least four processors. Further assume that no other stations are transmitting while endpoint 104 is transmitting.
Upon receipt of the four packetized data units through the port (entry and exit points of nodes associated with specific data links are generally referred to as "ports") of central node 100 associated with data link 124, central node 100 essentially contemporaneously delivers them to individual processors in the sequence the packetized data units were received. Now, assuming that the clock speed (a factor which influences the speed in which data can be processed by a processor) of the processor in which the third packetized data unit received is faster than those of the other three processors. As a consequence of this, assume that the processor holding the third received packetized data unit completes its processing first. Consequently, the third in received packetized data unit will be the first to be transmitted through the port of central node 100 associated with data link 136, and thus the third in sequence data packet transmitted by endpoint node 104 is the first received by destination endpoint node 116. Thus, the sequence of the packetized data units has been destroyed.
Such destruction of sequencing is a byproduct of multiple processor nodes. There are many applications, well known in the art, where such loss of sequence is unacceptable (e.g., real-time video conferencing, or real-time remote patient monitoring). However, as was noted above, since multiple processor nodes have very real benefits it is desirable to continue using them, albeit in a way that does not destroy sequencing of packetized data units.
It is apparent from the foregoing that a need exists for a method and system, which can be used with multiprocessor network nodes, and which will ensure that the sequence in which data units enter one or more specific ports of a multiple processor node is preserved when those same data units subsequently exit from the multiprocessor node. It would be further advantageous is the method and system could be implemented in new network nodes as well as retrofitted to existing network nodes.

Maintaining frame sequence in a multiprocessor network device

International Business Machines Corporation


Data storage methods and apparatus are disclosed that utilize a swept-carrier optical approach with an inhomogeneously broadened absorber material having multiple special storage cells. Data are encoded on a data pulse by appropriately modulating the data pulse. Data storage in a storage cell is effected by exposing the cell to the data pulse and a reference pulse cotemporal with the data pulse. Both the data and reference pulses are frequency-chirped across the inhomogeneously broadened bandwidth of the absorber material, the data pulse being chirped at a frequency that is offset relative to the reference pulse. Data retrieval from the storage cell is performed by exposing the cell to a read pulse which causes the cell to produce a signal pulse comprising the encoded data. The read pulse can have a temporal profile that produces a signal pulse shaped either similarly to the data pulse or as a mirror image of the data pulse.

The simplest optical data system stores and recalls data by means of either absorption or reflection of a light beam interacting with atoms or molecules comprising a data storage material. A series of data bits can be stored in and read from the storage material by directing a beam of light to spatial storage cells on the material. A "spatial storage cell" is a spatially distinct region of the storage material capable of storing at least one bit of data. An example of a spatial storage cell is a region having a defined area on the surface of the material and extending depthwise, within the length and width boundaries of the cell, into the thickness dimension of the material. A typical unit of data storage material has many millions, if not billions, of storage cells. Each cell can be individually and separately "addressed" for data storage or retrieval by using a laser beam.
The ultimate optical memory device would be one in which a bit of data could be stored in virtually every atom or molecule of the storage material. Such an optical memory would have a storage capacity of about 10.sup.22 bits per cm.sup.3. However, as discussed further below, this ultimate goal is unattainable by current technology.
One promising class of optical memories consists of so-called "frequency-selective optical data storage" (FSDS) memories. A volatile FSDS memory is disclosed in Szabo, U.S. Pat. No. 3,896,420 (Jul. 22, 1975). A relatively non-volatile FSDS memory is disclosed in Castro et al., U.S. Pat. No. 4,101,976 (Jul. 18, 1978).
In general, the spatial dimensions of individual storage cells in optical memories cannot be smaller than .zeta., the wavelength of light employed to add data to and read data from the memory. Since the wavelengths of lasers typically used for writing data into and reading data from optical memories are about 10.sup.-4 cm, the maximal usable number of spatial storage cells in the memory is about 10.sup.12 per cm.sup.3.
FSDS memories are advantageous in that they allow atoms or molecules within a spatial storage cell to be addressed both spatially and spectrally. Since such a memory has the three usual spatial dimensions plus one frequency "dimension," it is often referred to as a "four-dimensional" memory.
FSDS methods utilize data-storage materials in which the storage cells exhibit an "inhomogeneously broadened" absorption profile, as shown in FIG. 1. An inhomogeneously broadened spectral profile having width .DELTA..nu..sub.i in FIG. 1 is a composite of a number of homogeneous spectral lines (e.g., .DELTA..nu..sub.h.sbsb.A, .DELTA..nu..sub.h.sbsb.B, and .DELTA..nu..sub.h.sbsb.C in FIG. 1) each exhibiting a slightly different resonant frequency. Although such data-storage materials typically comprise a substantially uniform assemblage of constituent atoms or molecules, the inhomogeneously broadened spectral profiles of these materials are wider, often much wider, than the absorption profiles of the constituent atoms or molecules. This is because the microenvironment surrounding each individual atom or molecule in the material is different for each atom or molecule which, in turn, imparts a variation in the absorption profile of each atom or molecule. Such microenvironments include small variations in the local electric field surrounding each atom or molecule relative to neighboring atoms or molecules and, in the case of crystalline materials, various imperfections in the crystalline matrix of the material. Thus, each constituent atom or molecule of a storage cell displays a spectrally narrow (i.e, "homogeneous") resonance each having a width of .DELTA..nu..sub.h. The resonances of the individual atoms or molecules in the cell are collectively spread over the inhomogeneously broadened frequency range (having a width of .DELTA..nu..sub.i). Of course, since each storage cell consists of billions of atoms or molecules, it is virtually certain that any given .DELTA..nu..sub.h will be exhibited by more than one atom or molecule in the cell.
In FSDS, if a spatial storage cell of a material having an inhomogeneously broadened spectral profile (i.e., of a material termed an "inhomogeneously broadened absorber" or "IBA") is illuminated by a source of electromagnetic radiation having a specific incident frequency, the entire cell does not undergo a photo-induced change in optical properties. Rather, only those particular atoms or molecules in the cell having a .DELTA..nu..sub.h value at a resonant frequency corresponding to the particular incident frequency undergo such a photo-induced change. This results in formation of a "notch" or "hole" in the inhomogeneously broadened spectrum at the particular resonant frequency (.nu..sub.incid in FIG. 1). Such a frequency-selective saturation phenomenon is termed "hole burning" in the art. Since a number of holes can be burned into the inhomogeneously broadened spectral profile of each storage cell, it follows that, in FSDS memories, one can "write" more than one data bit in each storage cell.
The smallest currently usable spatial storage cell has surface dimensions of about 10.sup.-4 cm on a side. (Individual atoms are about 10.sup.-8 cm across.) Assuming that such a cell has a depth of 10.sup.-4 cm, about 10.sup.12 atoms would be present in the cell. In some storage materials, up to .DELTA..nu..sub.i /.DELTA..nu..sub.h .apprxeq.10.sup.7 frequency subdivisions are possible in each spatial storage cell. Thus, by addressing atoms in the cell both spatially and spectrally, it is possible to individually address groups of atoms containing only about 10.sup.5 atoms each (wherein each group exhibits a different .DELTA..nu..sub.h). To address the same number of atoms with spatial addressing alone, the storage cell would have to be less than 10.sup.-6 cm across, which is too small to be addressable by current technology. With combined spatial and spectral addressing, it is possible to attain data storage densities of 10.sup.18 bits per cm.sup.3 of memory volume, which is 10.sup.7 times denser than what is obtainable with current magnetic memories that offer a surface bit density of about 10.sup.15 bits/cm.sup.2.
Two general types of FSDS memories are known in the art, both of which can (at least in principle) achieve the same ultimate data storage density. The first type is termed "directly addressed" FSDS (also known in the art as "frequency-domain" FSDS) and the second type is termed "temporally addressed" FSDS (also known in the art as "time-domain" FSDS), both of which are briefly described below.
Both FSDS approaches are limited by certain fundamental relationships. For example, in either approach, a monochromatic light source such as a laser is used for data writing and reading. Digital data to be stored ("written") in the memory can be in the form of digital pulses ("ones" and "zeros") superimposed on the substantially monochromatic frequency of the laser. Such pulses are typically created by passing the laser beam through a controllable shutter. If the shutter is open for a time .tau., the resulting pulse passing through the shutter has a duration .DELTA..tau..sub.pulse =.tau.. However, even though the laser beam upstream of the shutter is monochromatic, the pulse passing through the shutter will experience a frequency spread having a width .DELTA..nu..sub.pulse about the laser's monochromatic light frequency .nu..sub.L. Thus, .DELTA..nu..sub.pulse =1/.DELTA..tau..sub.pulse. The longer the pulse, the narrower (i.e., more monochromatic) the frequency spectrum of the pulse. This relationship, termed the Fourier bandwidth theorem, significantly impacts how much data can be written into an optical memory that is spectrally addressed. With memories employing spectral channels of a specific frequency width, a minimum time is required to access a single spectral channel; the narrower the spectral channel, the longer the access time required.
In "directly addressed" FSDS such as disclosed in Burland, U.S. Pat. No. 4,158,890 (Jun. 19, 1979), and in Szabo, U.S. Pat. No. 3,896,420 (Jul. 25, 1975), highly monochromatic lasers are utilized for data storage and retrieval. A "data-write" laser is spatially positioned to address the various spatial storage cells on a storage material and frequency-swept to address individual spectrally distinguishable subgroups of atoms or molecules within each spatial storage cell. (Each such spectrally distinguishable subgroup is termed a "spectral channel"). Within a spectral channel, an "on" bit is represented by a write-induced change in the absorptivity of the active atoms or molecules in the channel.
The ultimate narrowness of the spectral channels is determined by the homogeneous absorption bandwidth .DELTA..nu..sub.h of the corresponding storage material. The homogeneous absorption bandwidth .DELTA..nu..sub.h is an expression of the range of light frequencies (about an atom- or molecule-specific median frequency) within which an atom or molecule in the spectral channel will strongly interact with an incident light beam. If spectral channels are spaced at less than .DELTA..nu..sub.h, writing data to one spectral cell will affect data stored in spectrally adjacent cells. Therefore, maximal storage density is achieved when the spectral channel width is equal to .DELTA..nu..sub.h.
The drawbacks associated with directly-addressed FSDS arise from a need to rapidly tune the read and write lasers to specific frequencies. This is because the data bits are written (and read) sequentially directly into (and from) frequency-domain spectral channels. Also, a spectral channel of width .DELTA..nu..sub.h cannot be individually accessed in a time shorter than about .DELTA..nu..sub.h.sup.-1. Therefore, the data input/output rate of directly addressed FSDS memories is rather slow, limited to about .DELTA..nu..sub.h bits per second. (The maximum speed at which holes can be burned is determined by the relationship .DELTA.t.sub.h.DELTA..nu..sub.h .apprxeq.1, where .DELTA..nu..sub.h is the single-channel access time and .DELTA..nu..sub.h is the spectral width of the channel.) For example, in a storage material having 10.sup.7 spectral channels, the minimal spectral channel width is equal to .DELTA..nu..sub.h =10.sup.3 Hz. With such a channel width, the maximum data transfer rate is only 1 Kilobit/sec. Since a cm.sup.3 of such a material could contain 10.sup.18 bits of information, it would take millions of years to write or read such a memory at 1 Kilobit per second.
Therefore, it is impossible using directly addressed FSDS to simultaneously optimize storage density and memory speed. I.e., if the storage capacity of the absorbing material in the memory is increased by making each spectral channel narrow, one unavoidably increases the time needed to create and retrieve information from that spectral channel.
"Temporally addressed" FSDS is also termed "time-domain" FSDS or "stimulated echo FSDS" in the art. Mossberg, U.S. Pat. No. 4,459,682 (Jul. 10, 1984); Carlson et al., Phys. Rev. A 30:1572 (1984); Bai et al., Opt. Lett. 11:724 (1986); Mossberg, Optics Lett. 7:77-79 (1982). In temporally addressed FSDS, the maximum permissible rate at which storage cells are accessed is also dependent upon the material comprising the data storage medium. During data "writing," each spatial storage cell is exposed to a writing laser beam for a time that can be as long as .DELTA..nu..sub.h.sup.-1. However, unlike directly addressed FSDS, each spectral channel within a spatial storage cell can be simultaneously addressed. I.e., .DELTA..nu..sub.i /.DELTA..nu..sub.h bits (one for each available spectral channel) can be simultaneously encoded and stored in the cell. The storage of all these bits in the cell occurs in parallel during a time interval equal to that required to store a single bit in a cell using directly addressed FSDS.
In temporally addressed FSDS, two types of pulses are involved in a "writing" sequence (the storage of a bit stream in a spatial storage cell). One of said pulses is termed the "reference pulse" (also termed "preparation pulse," "write pulse," or "fixing pulse" in the art). The reference pulse can be temporally short compared to the bandwidth of the bit stream to be stored. The second pulse, termed the "data pulse" (also termed the "object pulse" or "writing pulse" in the art) consists of the actual stream of data bits to be stored in the cell.
The data pulse is produced by passing a laser beam through a high-speed laser shutter so as to digitally encode a train of binary bits onto the laser beam. The frequency content of such a data pulse is complex and unique to the particular data stream encoded therein. Since a temporally encoded laser pulse carries a unique frequency-spectrum signature, storage of such a spectrum in a cell constitutes a storage of all the temporally encoded data. By illuminating a single spatial storage cell using a temporally encoded data pulse, many of the spectral channels in the cell are simultaneously addressed.
The reference pulse is necessary for recording the data in the cell. If the cell is exposed only to the data pulse, then only the power spectrum of the data pulse is recorded, which is an insufficient basis for later recall (reading) of the data from the cell in a temporally faithful manner.
The reference pulse can either precede the data pulse or follow the data pulse. The temporal order of these pulses is a determinant of whether the data in the data pulse can be recalled from the cell as a faithful copy of the data pulse or as a time-reversed copy of the data pulse. See, Mossberg, U.S. Pat. No. 4,459,682; Carlson et al., Phys. Rev. 30:1572-1574 (1984). In either event, the reference and data pulses sequentially enter the cell.
Thus, in temporally addressed FSDS, it is the Fourier spectrum of the bit stream in the data pulse that is recorded in the spectral channels of the addressed cell. Because the write and data pulses constructively and destructively interfere with each other in exciting the active atoms or molecules comprising the cell, the time separations and phase relationships between these laser pulses are, in effect, holographically impressed on the absorbing atoms or molecules. This results in storage of information in the form of modulations in the hyperfine energy sublevels of the absorbing atoms or molecules as a function of absorption frequency. That is, the Fourier spectrum is represented through frequency-dependent changes in the absorption profile of the atoms or molecules comprising the cell. The spectral distribution of the atoms or molecules in the cell, after being exposed to the preparation and object pulses, is proportional to the Fourier transform of the object pulse.
Temporally addressed data in a storage cell are recalled or "read" by stimulating the storage cell to emit a coherent optical signal ("signal pulse") having the same duration and temporal envelope as the stored bit stream. Data reading is usually initiated by a single laser pulse, called the "read" pulse, which can be identical to the reference pulse. In effect, the read pulse causes the previously stored data to be holographically reexpressed. The signal pulse, then, is a result of constructive and destructive interactions of energy discharged from the previously stimulated atoms or molecules of the cell. The signal pulse can also be envisioned as an "echo" of the data pulse, wherein the signal pulse has the same temporal envelope as the data pulse. I.e., the temporal profile of the signal pulse is proportional to the Fourier transform of the spectral distribution of the excited population of atoms or molecules.
The signal pulse is a coherently emitted signal (which makes it highly directional). If the pulses involved in the writing sequence are colinear, the signal pulse will have directional properties essentially identical to the data pulse. In general, the wavevector of the signal pulse is related to the wavevectors of the pulses involved in the write sequence according to: EQU k.sub.s =k.sub.d +k.sub.r -k.sub.w
where k.sub.w, k.sub.d, k.sub.r, and k.sub.s are the wavevectors of the write (reference), data, read, and signal pulses, respectively.
As discussed above, in the directly addressed FSDS method, data input and output rates are limited by the spectral channel width, and by the fact that each spectral channel within each spatial storage cell must be serially addressed. With temporally addressed FSDS, the ability to address all spectral channels of a spatial storage cell in parallel provides a substantial speed advantage of .DELTA..nu..sub.i /.DELTA..nu..sub.h over directly addressed FSDS. However, the total duration of the write sequence (write and data pulses) for each channel must be shorter than the homogeneous dephasing time of the storage material. Data input and output must occur at a rate of .DELTA..nu..sub.i bits per second in order to utilize the full storage potential of the storage material. In cases where .DELTA..nu..sub.i exceeds obtainable rates of data input and output, only .DELTA..nu..sub.m /.DELTA..nu..sub.h bits (where .DELTA..nu..sub.m is the maximum achievable rate of data input and output; i.e., the maximum achievable data modulation rate) can be stored using temporal addressing FSDS. This can also pose a substantial rate limitation because full inhomogeneous absorption bandwidths often exceed currently achievable modulation rates.
Therefore, there is a need for optical memories that allow one to achieve complete spectral utilization of the storage material while employing variable rates of data input and output.

Swept-carrier frequency selective optical memory and method

State of Oregon acting by and through the State Board of Higher Education on behalf of the University of Oregon


A process for treating effluent streams in a renewable transportation fuel production process is described. One or more of the sour water stream and an acid gas stream are treated directly in thermal oxidation section. The process allows the elimination or size reduction of a sour water stripper unit, waste water treatment plant, and sulfur recovery unit.

As the demand for diesel and jet boiling range fuel increases worldwide, there is increasing interest in feedstock sources other than petroleum crude oil. One such source is what has been termed "renewable" and "biological" feedstocks. These renewable biological feedstocks include, but are not limited to, plant oils such as corn, jatropha, camelina, rapeseed, canola, and soybean oil, algal oils, and animal fats such as tallow and fish oils. The common feature of these sources is that they are composed of glycerides and Free Fatty Acids (FFAs). Both of these classes of compounds contain normal aliphatic carbon chains having from about 8 to about 24 carbon atoms. The aliphatic carbon chains in the glycerides or FFAs can be fully saturated or mono, di- or poly-unsaturated. The sidechains of the glycerides and the FFAs in biological oils and fats can be converted into diesel or jet fuel using many different processes, such as hydrodeoxygenation and hydroisomerization processes.
Fuel processed from renewable biological sources is desirable for a variety of reasons. Foremost, the use of renewable biological-sourced fuels reduces the demand for the extraction and use of fossil fuels. This is especially true for transportation fuels such as diesel and jet fuel. In addition to the ecological benefits of using biological-sourced fuel, there exists a market demand for such fuel. For fuel purchasers, the use of biological-sourced fuel can be promoted in public relations. Also, certain governmental policies may require or reward use of biological-sourced fuels.
Current renewable transportation fuel production processes produce a variety of effluent streams that must be treated and disposed of.
It would be desirable to reduce the complexity of the process while providing proper treatment of the effluent streams, especially those related to acid gas and sour water. It would also be desirable to reduce the cost of the chemicals used in treating the effluent streams. It would also be desirable to reduce the amount of equipment in the complex.

Renewable transportation fuel process with thermal oxidation system


A device for recycling developer fixer into a photo processing machine. The device includes containers for containing chemicals coming out of overflow outlets of the photo processing machine. The chemicals flow into the container, and a portion thereof are recycled and returned together with fresh chemicals to the processing machine. A portion of the used chemicals are discharged to a drain. The recycled chemicals can either be pumped into an automixer where the fresh chemicals are added or directly into the inlet line to the photo processor tank where fresh chemicals are simultaneously also input. Alternately, the overflow can be directed to the automixer first and either returned directly therefrom, or optionally, by way of a separate container, to the photo processing machine.

This invention relates to photo processing machines, and in particular to apparatus for automating the recycling of developer and fixer chemicals in such machines.
In my co-pending application Ser. No. 07/617,522 filed Nov. 23, 1990 I described a system for recycling photographic developer. I have now discovered that similar principles can be utilized in connection with photographic fixers, as well. I have also discovered further ways to provide for recycling of both developers and fixers in small photo finishing equipment.
To date, it has been difficult and expensive to reuse and recycle fixers and developers. There are those who believe that it is merely necessary to cut back the replenisher rate for each film. For instance, if the normal rate is 100 cc, the recycling could be accomplished by reducing it to 50 cc. The problem with that approach, however, is that it does not account for the buildup of certain salts that can act to inhibit the photographic fixing process. The only way to avoid such a buildup is to redilute the used fixer with new fixer while continually removing a portion of the used chemicals.
The only method for doing so to date has been practiced only in large photo finishing plants and large hospitals, both of which have central mixing facilities. In those cases an operator could isolate several hundred gallons of used fixer and reintroduce that fixer into several hundred more gallons of new fixer. This process is expensive even for such large companies because of the labor-intensive nature of the work, and is simply unavailable for smaller companies.

Chemical recycler for photo processing machine


A process for producing a catalyst for olefin cracking, the process comprising the steps of providing an MFI-type crystalline silicate catalyst, heating the catalyst in steam to remove aluminum from the crystalline silicate framework and extracting aluminum from the catalyst by contacting the catalyst with a complexing agent for aluminum to remove from pores of the framework aluminum deposited therein during the steaming step thereby to increase the silicon/aluminum atomic ratio of the catalyst; and calcining the catalyst at elevated temperature.

The present invention relates to a process for producing a catalyst for the catalytic cracking of olefins, in particular a cracking process which is selective towards light olefins in the effluent. In particular by using such a catalyst, olefinic feedstock from refineries or petrochemical plants can be converted selectively so as to redistribute the olefin content of the feedstock in the resultant effluent.

Production of catalysts for olefin conversion


A process for preparing a lap seam for roofing comprising applying a butyl rubber-containing primer with a mesh pad to the EPDM membrane surfaces to be joined. The primer is applied with a long-handled applicator to permit the roofer to stand during priming. Thereafter a splice tape is positioned between the primed surfaces to form a seam structure and pressure is applied to the structure thus provided to form an adhesively-held lap seam characterized by being watertight and having superior peel strength when compared to other methods of making seam tapes.

The use of roofing systems capable of successfully maintaining their integrity, particularly their ability to prevent the entry of water resulting from their exposure to rain, snow, or other causes is a fundamental requirement for any successful building structure, particularly roofing in connection with flat or low-slope roofs installed on commercial, institutional, and industrial buildings.
In the past, a variety of roofing systems have been used in connection with such buildings including, for example, metal panel roofing. Such roofing usually consists of metal panels overlapped at their ends and secured to the roofing decks of building structures with nails, screws, clips or other fasteners. However, while metal panels are relatively durable, the panels are subject to significant thermally induced contractions and expansions due to ambient temperature variations, a characteristic that often leads to the cracking of such roofing, especially along the roof seams and fastener locations, with leakage occurring as a result thereof.
Another type of roofing commonly employed for such buildings is the so-called built-up roofing system. The latter type of roofing depends upon the application of asphaltic compounds to secure felt or other membranes over suitable insulation attached over metal roof decking. While such systems are often used, they can be relatively expensive to provide, and again thermal contraction and expansion of the roofing system can result in cracking of the roof covering along its seams and fastener locations, resulting in roof leakage.
The latter type of roofing also undesirably increases the weight of the roofing surface, which can add unwanted stress to buildings on which such roofing is installed. Additionally, the use of hot asphalt is sometimes prohibited by local building codes. Finally, built-up roofing systems typically eventually require retrofit roofing installations and these can be difficult to provide in view of the fact that they sometimes necessitate the provision of intermediate foundation layers, such added layers creating further roofing support problems. In fact, not uncommonly, these retrofit installations can result in the shifting of the roofing deck itself, movement which causes still more cracks and further leakage.
In order to overcome the foregoing and other problems associated with such roofs, resort has increasingly been had to the use of roofing membranes formed from ethylene/propylene/non-conjugated diene rubber, EPDM, membranes. In this regard, EPDM membranes have proven to be admirably suited for roofing systems since they have a long life, substantial flexibility and retain their resiliency at very low temperatures. They are also distinguished by their ability to withstand the high temperatures frequently encountered in roofing environments without unduly stretching or softening, and by their possession of a high order of resistance to ultraviolet light. EPDM elastomers are usually blended with fillers, coloring agents, extenders, crosslinking agents and antioxidants to form compounded rubbers that are then calendered or extruded into sheets or membranes, typically about 7 to 40 feet wide, and 100 or more feet long.
In many roofing installation situations in which such membrane sheets are employed, however, it becomes necessary to overlap (i.e., adjacently position) a number of the sheets in watertight splices to obtain the required complete roof-top coverage. In one such splicing system, the procedure involves thoroughly cleaning the surface of the membranes to be joined in an overlapped seam. Such cleaning is required in order to remove the talc or mica dusting used by manufacturers to keep the membrane surfaces from sticking together in the rolls in which they are marketed. Cleaning is typically done by a roofer on hands and knees who vigorously scrubs the surface to be joined with a rag wetted with hexane, naphtha, gasoline or some other similar material. Thereafter, a membrane adhesive, commonly consisting of a 25-30 percent by weight solution of rubber in a suitable solvent is brushed over the surfaces to be adhered. Following drying of the contained solvent, the surfaces are joined and pressed together to form the desired seam. In some instances, a "primer" consisting of a dilute solution of rubber in a suitable solvent is applied to the surfaces to be joined prior to application of the membrane adhesive in order to improve the final seam adhesion. Thereafter, lap-edge caulking is often added to the overlapped edges of the seam in order to protect the finished seam.
While the system described is conceptually simple, in practice it suffers from being both labor and material-intensive, and it also results in relatively low seam peel strengths. Furthermore, for environmental and health reasons it is undesirable, and increasingly unlawful in specific air quality management districts, to use a system that employs so much volatile organic compound (VOC) in the form of required components.
Partially to reduce the amount of VOC's, as well as to improve seam strengths, an alternative system has relied upon so-called seam tapes to obtain the necessary adhesion. Seam tapes, as the name implies, are tacky strips of adhesives commonly formed from butyl or other rubbers, which are compounded to include rubber tackifiers and other agents required to impart adhesive qualities.
The seaming process entails the initial cleaning of the surfaces to be joined with a liquid organic cleaner-impregnated rag to remove anti-stick dusting powders. Following such cleaning, a dilute seam primer containing from about 5 to 9 percent by weight of rubber in a solvent therefor is applied to the membrane seam overlap surfaces. Following drying, tape is applied over the primed surfaces and pressure is applied to the seam to secure the necessary joinder.
While the use of seam tape eliminates the VOC's which would otherwise be present as a consequence of the solvents in seam adhesives, the need to clean the surfaces with liquid organics and the relatively large amount of solvents present in the very dilute primer make the escape of large amounts of VOC's to the atmosphere unavoidable. In addition, the need to perform both a cleaning process as well as a priming operation necessarily results in relatively high installation costs as a result of the additional labor and material required.
An additional shortcoming to the state of the art in the roof seaming industry is that a roofer performs virtually all operations in a kneeling position. It is an advantage to develop equipment which changes the process to allow the roofer to be relieved from this tiresome and potentially harmful posture.
In view of the foregoing it is therefore a first aspect of this invention to provide a process for installing membrane roofing seams which eliminates any need to perform a separate cleaning step.
A second aspect of this invention is to provide a process for installing seams in membrane roofing systems using seam tapes that utilize primers containing lower amounts of volatile organic compound materials.
A further aspect of this invention is to provide roofing seam primers whose application to the roofing membranes obviates the need to initially clean the surfaces to be joined.
An additional aspect of this invention is to provide roofing primers whose application to roofing membranes also serves to clean the areas of membranes to be joined.
Another aspect of this invention is to reduce the amount of volatile organic compound materials that are available to enter the atmosphere.
Yet a further aspect of this invention is to provide roofing seam primers and a method for their application that increases the peel strength of the membrane roofing seams prepared therewith.
Still another aspect of this invention is to provide a method for installing seams in membrane roofing systems which reduces installation costs as well as the amount of fill material needed for low areas, step-offs, etc., to provide a smooth surface for receiving seam tape.
In another embodiment, an additional aspect of the invention is to provide a membrane pre-adhered to a seam tape having a release backing for use with the process of the present invention in roofing installations.
In yet another embodiment, an additional aspect of the invention is to provide a method of seaming a roof utilizing an applicator having an elongated, upright, swivel handle attached to a bearing surface which holds a scrub pad such that the primary step may be performed in a standing position or not.

Roofing seam installation process and products for the production of a seamed roof


Improved systems, apparatus, and methods for detecting positions of moving stages and accurately compensating position error during operation (in “real time”) are provided. For some embodiments, rather than rely on two dimensional position measurements, measurements in at least three dimensions may be taken allowing compensation for pitch and roll and, therefore, more accurate position measurements. Further, by including a measurement of a beam column, compensation for movement of the beam may be performed.

In charged particle beam (CPB) systems, specimens or "workpieces" are retained on movable stages for positioning relative to the beam. Charged particle beam systems are used in a plurality of industrial fields, including, but not limited to, testing systems, imaging systems like scanning electron microscopes (SEMs), inspection systems for semiconductor devices, and exposure systems for pattern writing via lithography.
There is a high demand for structuring, testing and inspecting specimens within the micrometer and nanometer scale. Micrometer and nanometer scale process control, inspection or structuring is often done with charged particle beams, e.g. electron beams. Charged particle beams offer superior spatial resolution compared to, e.g. photon beams, due to their short wavelengths. However, there are also light optical systems with a stage that supports a specimen and the stage being movable to position the specimen with a precision of 50 nm or better.
Generally, as the precision of measurement, testing, or patterning systems increases there is a demand for high precision and fast positioning of specimen in those system. The stage holding the specimen is typically independently movable in x-direction and y-direction. In conventional systems, positioning data of the stage is measured in two perpendicular axes (e.g., X and Y axes). The electron beam of the e-beam inspection tool is deflected by a vector opposite to that of the measured error in position.
Unfortunately, prior art systems typically assume a negligible effect of pitch and roll and assume a fixed primary beam with respect to the plane of interest. However, in practice, the effects of pitch and roll may be significant and result in significant positional errors. Further various sources may also cause movement of the primary beam, which may also result in significant positional error.
Accordingly, what is needed is improved systems for detecting positions of moving stages and accurately compensating position error during operation (in "real time").

Real-time compensation of mechanical position error in pattern generation or imaging applications


Apparatus for determining in-blow % carbon content and/or the First Turn Down Carbon of a BOF heat includes a light sensor housed within a temperature regulated case having a sighting window including air wipe means to shield the light sensor from steelmaking dust and fume. The apparatus also includes a means to generate a signal that corresponds to the amount of oxygen blown into the BOF during a heat, and a programmable logic controller. The logic controller is programmed to continuously process oxygen blown signals from the signal generating means, and light intensity signals received from the light sensor. The program calculates continuous in-blow % carbon content of the heat based upon the difference in light intensity from a point of maximum light intensity emitted from the BOF vessel in relation to the amount of oxygen blown into the BOF vessel during the same period of time.

This invention is directed to a method and apparatus for controlling or determining the carbon content of a heat in a BOF vessel, and more particularly, to a method for determining the in-blow carbon content and the First Turn Down Carbon (FTDC), in low carbon steel BOF heats containing 0.06% or less carbon.
Users of flat rolled steel product demand low carbon grade steel because of its good formability properties. For example, in the automotive industry, such low carbon steel permits auto manufacturers to stamp and form complex automobile shapes without encountering steel spring-back after the foraging operations. This makes it necessary for steelmakers to accurately manage and control the carbon content of their BOF heats to produce a product having the proper metallurgical requirements.
In the BOF steehnaking  steelmaking process carbon saturated liquid iron is poured into the vessel along with various amounts of steel scrap. tligh  and high velocity oxygen is blown into the BOF vessel at the surface of the molten steel bath where it reacts with the carbon to form CO and CO2. This reaction removes excess carbon in the steel bath and produces a finished product having the desired carbon content.
There are many BOF process control methods available to preset day steelmakers. These controls range from sophisticated predictive models that are managed through the use of computers in combination with sensor instruments such as gas analyzers, thermocouples, load cells, etc.
In the past, various attempts have been made to control the carbon content in a vessel using flame drop measurements. One such past attempt is shown in U.S. Pat. No. 3,652,262 granted to Denis. This patent discloses using a sensor to detect infrared radiation emitted from a BOF vessel. The signal from the infrared sensor is processed to generate a curve representing a function of radiation intensity against time. In his patent, Denis compared his radiation curve with a decarburization curve generated by using readings taken from a first gas pickup used to measure the concentration of CO2 and CO in the off-gas of a BOF vessel, and from a second gas pickup used to measure the total gas output. He then compared the two curves and concluded that his time/radiation curve was useful in providing an instantaneous carbon reading during BOF steelmaking operations. However, if the two different graphs are compared, it can be seen that wide variations in predicted carbon levels occur between the off-gas curve and the radiation curve. Therefore, although Denis has provided some improvement in providing an instantaneous reading of carbon content during a heat, his patent shows a wide margin of error in his predicted carbon levels based upon his flame drop readings.
Additionally, in a study found in chapter fifteen entitled xe2x80x9cBOF Controlxe2x80x9d, of an Iron and Steel Society publication xe2x80x9cBOF STEELMAKINGxe2x80x9d dated 1977, J. H. Cox, et al. teach that flame intensity is a function of the carbon in the bath. However, the authors also teach that carbon predictions, based upon flame intensity measurements, are not satisfactory for the more stringent present day needs.
Such beliefs have become widespread throughout the steelmaking industry. They have led steelmakers to use control strategies based on statistical, predictive-adaptive control models, or highly sophisticated control systems based on a continuous or periodic measurement of variables such as carbon, temperature, etc. (J. H. Cox, et al. xe2x80x9cBOF STEELMAKINGxe2x80x9d). One such measurement process is based upon mass/temperature calculations to determine the carbon content of a BOF heat. It is well known that such mass/temperature calculations contain a margin of error, and they often lead to either overblowing or underblowing the BOF heats.
In instances where a heat is overblown various undesirable chemical reactions take place within the vessel. For example, in an overblown heat, the oxygen consumes an excessive amount of carbon and a steel product having an undesirable low carbon level is produced. The excess oxygen also reacts with the molten iron to form iron oxides. This reduces the iron yield of a heat. Overblowing a heat will also overheat the steelmaking vessel, cause premature wear on its protective refractory lining, and reduce the service life of the vessel.
In those instances where a heat is underblown, the heat may have to be reblown to further reduce the carbon level. This increases production time and cost, and causes excess refractory wear. The excess refractory wear is due to the iron oxides that are formed in the slag during the reblow. Iron oxides in the slag make the slag more corrosive to the refractory lining.
Another problem encountered with BOF control systems is dealing with the hostile environment adjacent the hot BOF vessel. The radiant heat emitted from a BOF vessel during the steelmaking process overheats sensitive electronic equipment located near the vessel and causes system failures. Dust and fume released from the vessel also settles on equipment located throughout the steelmaking shop, including the various sensor devices used to control the steelmaking process. The dust and fume causes control equipment sensors to become fouled and dirty, and results in poor readings and inaccurate metallurgical analysis.
It is therefore an object of this invention to provide a method for determining the carbon content of a BOF heat.
It is still a further object of this invention to accurately control or determine the carbon content of a BOF heat within a margin of error of about 0.004% C.
It is still a further object of this invention to accurately control or determine the carbon content of a BOF heat by measuring a difference in visible light intensity emitted from the BOF vessel in relation to the amount of oxygen blown into the vessel.
It is still a further object of this invention to provide apparatus for controlling and/or determining carbon content of a BOF heat, the apparatus being resistant to high temperatures encountered in the steelmaking process.
And finally, it is still a further object of this invention to provide apparatus, for controlling and/or determining the carbon content of a BOF heat, that includes a self cleaning means to prevent an accumulation of fume or dust on its sensor devices.
We have discovered that the foregoing objects can be attained by measuring a drop in visible light intensity emitted from a BOF vessel with a light sensor housed within a temperature regulated case having a sighting window including air wipe means to shield the light sensor from steelmaking dust and fume. The drop in visible light intensity is measured from a point of maximum light intensity emitted from the BOF vessel in relation to the amount of oxygen blown into the BOF vessel from such point of maximum light intensity, to the end of the oxygen blow. The light intensity and oxygen readings are used to compute continuous, real time in-blow % carbon levels until an aim carbon content is reached for the heat.

Method and apparatus to determine and control the carbon content of steel in a BOF vessel


Aspects of the description provide for an analog-to-digital converter (ADC) operable to convert an analog input signal to an output signal at an output of the ADC. In some examples, the ADC includes multiple sub-ADCs coupled in parallel, each of the multiple sub-ADCs coupled to the output of the ADC and operable to receive the analog input signal. The ADC is configured to operate the sub-ADCs in a consecutive operation loop including a transition phase in which the ADC operates each of the sub-ADCs sequentially for a first number of sequences, an estimation phase in which the ADC operates each of the sub-ADCs sequentially for a second number of sequences following the first number of sequences, and a randomization phase in which the ADC operates subsets of the sub-ADCs for a third number of sequences following the second number of sequences.

Analog-to-digital converters (ADCs) with high sampling rates are becoming more prevalent, such as in multi-Gigabit communication systems (e.g. wireless infrastructure systems), radar systems, etc. Such systems may operate in frequency bands of about 1-4 gigahertz, or greater. One approach for implementing a high sampling rate ADC is to use a time-interleaved architecture with multiple sub-ADCs coupled in parallel, where each of the sub-ADCs may have a sampling rate less than the sampling rate of the full time-interleaved architecture.

Analog-to-digital convertor pseudo periodic IL estimation


Disclosed is a method and associated apparatus for compensating for kTC noise in individual pixels of an MOS imaging array. The kTC noise at issue forms when a pixel is disconnected from a reset voltage by turning off an MOS transistor which controls access to the pixel photodiode. Compensation is accomplished by first exposing the photodiode to the reset voltage and then disconnecting the well region from V.sub.dd to cause it to float. By allowing the well to float, the kTC charge subsequently introduced (at the conclusion of the reset process) redistributes so that most of it accumulates on the capacitor between the well and the substrate. Later, the well is reclamped to V.sub.dd, and the noise contribution stored in the well-substrate capacitor is canceled. A disclosed apparatus includes an array of pixels, each having a separate well. In addition, access of the well to a source of power (V.sub.dd) must be switchable. Therefore, a transistor is included at each pixel's connection to a V.sub.dd.

The present invention relates to pixel arrays for MOS cameras. More particularly, the present invention relates to techniques and associated apparatus for compensating for thermal noise variably introduced to individual pixels during resetting of a pixel array.
CMOS image sensors are now becoming competitive with charge coupled device ("CCD") array image sensors. Potential applications include digital cameras, night time driving displays for automobiles, and computer peripherals for document capture and visual communications.
Since the 1970s, CCD arrays have dominated the electronic image sensor market. They have outperformed CMOS array sensors in most important criteria including quantum efficiency, optical fill factor (the fraction of a pixel used for detection), charge transfer efficiency, readout rate, readout noise, and dynamic range. However, the steady improvement in CMOS technology (including increasingly small device size) has moved CMOS image sensors into a competitive posture. Further, in comparison to CCD technology, CMOS technology provides lower power consumption, increased functionality, and potentially lower cost. Researchers now envision single chip CMOS cameras having (a) integrated timing and control electronics, (b) a sensor array, (c) signal processing electronics, (d) an analog to digital converter, and (e) interface electronics. See Fossum, "CMOS Image Sensors: Electronic Camera On A Chip,"1995 IEDM Technical Digest, Wash. DC, Dec. 10-13, 1995, pp. 17-25 which is incorporated herein by reference for all purposes.
CCD arrays are limited in that all image data is read by shifting analog charge packets from the CCD array interior to the periphery in a pixel-by-pixel manner. The pixels of the CCD array are not randomly addressable. In addition, due to voltage, capacitance, and process constraints, CCD arrays are not well suited to integration at the level possible in CMOS integrated circuits. Hence, any supplemental processing circuitry required for CCD sensors (e.g., memory for storing information related to the sensor) must generally be provided on separate chips. This, of course, increases the system's cost.
Despite the advances of CMOS image sensor technology, certain remaining problems prevent their widespread acceptance. One such problem is the noise introduced in CMOS pixels, particularly "passive pixels"; active pixels contain an on-pixel amplifier while passive pixels do not. Read noise on a passive pixel is typically of the order of 250 electrons r.m.s., in comparison to 20 electrons on commercial CCD pixels.
The genesis of noise introduced on passive pixels can be understood as follows. In CMOS arrays, each pixel must be reset after the image is "read" . Generally, this reset step requires that each pixel have an associated transistor switched on to allow a reset voltage to reach the photodiode of the associated pixel. When the associated transistor is turned off, the voltage of the photodiode should be equal to the reset voltage. However, thermal noise in the transistor channel introduce some variability in the quantity of charge injected in each pixel after each reset. Because thermal noise is truly random, voltage variations on individual pixels occurring once will not necessarily occur with the same variation a second time. Therefore, it is impossible to sample the noise at an initial time, store information regarding that noise, and use the stored information for a correction.
Often in the following description, the thermal noise at the root of the above problem will be referred to as "kTC noise" . This is to indicate that the noise magnitude is related to k, the boltzmann constant, T, the temperature in Kelvin, and C, the capacitance in the current path. Technically, the magnitude of the noise is proportional to the square root of the product of the Boltzmann constant, the temperature in Kelvin, and the capacitance in the pixel's current path. The local temperature variations in each pixel give rise to this random noise.
What is needed is an improved MOS image sensor that can compensate for kTC noise.

Noise compensation circuit for image sensors