There is disclosed a silver halide light-sensitive color photographic material having a high sensitivity and excellent granularity. The photographic material contains in at least one of the emulsion layers the core/shell type tabular silver halide grains comprising:. a. a numerical ratio of monodispersed grains to all grains of 70% or more; PA0 b. an average aspect value of not less than 1 and less than 5; and PA0 c. a portion having a silver iodide content of 15.3 mol % or more in the core.

Recently, there has been increasing demand for higher sensitivity and more improved image quality.
One of the key factors affecting the sensitivity of a silver halide light-sensitive material and the quality of an image is silver halide grains. Efforts have been made in the art to develop silver halide grains for higher sensitivity and image quality.
It is generally known that image quality can be improved by employing silver halide grains with smaller grain sizes. However, such smaller grain sizes inevitably lower the sensitivity of a light-sensitive material and therefore, it is difficult to balance the sensitivity with the image quality.
There have been studied the methods of improving both sensitivity and image quality by controlling a sensitivity/size ratio of the silver halide grains. The examples thereof are the use of tabular silver halide grains, which are disclosed in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) Nos. 111935/1983, 111936/1983, 111937/1983, 113927/1983 and 99433/1984. These tabular grains have a larger surface area than those of regular octahedral, tetradecahedral and dodecahedral silver halide grains each having the same volume. Such larger surface area permits the silver halide grains to adsorb a larger amount of a sensitizing dye on the surface thereof and therefore to have an improved sensitivity.
Japanese Patent O.P.I. Publication No. 92942/1988 discloses tabular silver halide grains having therein a core of high AgI; Japanese Patent O.P.I. Publication No. 163451 discloses tabular hexagonal grains; and Japanese Patent O.P.I. Publication No. 163451/1988 discloses tabular silver halide grains having an aspect ratio of not less than 5. These methods can improve sensitivity and graininess to some extent, however, are insufficient for balancing a sensitivity with an image quality.

Silver halide light sensitive color photographic material


Apparatus and methods for allocating shared memory utilizing linked lists are provided which are particularly useful in telecommunications applications such as ATM. A management RAM contained within a VLSI circuit is provided for controlling the flow of data into and out of a shared memory (data RAM), and stores information regarding a number of link lists and a free link list in the shared memory, and a block pointer to unused RAM locations. A head pointer, tail pointer, block counter and empty flag are stored for each data link list. The head and tail pointers each include a block pointer and a position counter. The block counter contains the number of blocks used in the particular queue. The empty flag indicates whether the queue is empty. The free link list includes a head pointer, a block counter, and an empty flag. Each memory page of the shared data RAM receiving the incoming data includes locations for storing data. The last location of the last page in a block of shared data RAM memory is preferably used to store a next-block pointer plus parity information. If there are no more blocks in the queue, that last location is set to all ones. An independent agent is utilized in the background to monitor the integrity of the link list structure. Using the methods and apparatus of the invention, four operations are defined for ATM cell management: cell write, cell read, queue clear, and link list monitoring.

1. Field of the Invention
The present invention relates to memory management. More particularly, the present invention relates to apparatus and methods of managing a plurality of data queues stored in linked lists in a shared common memory. The invention has particular application to the use of a very large scale integrated circuit (VLSI) for the buffering of telecommunications information such as ATM data, although it is not limited thereto.
2. State of the Art
In high speed communication networks, the management of buffer resources is one mechanism of increasing network performance. One group of methods of managing buffer resources is known as sharing, where a single RAM is simultaneously utilized as a buffer by a plurality of different channels. Various sharing methods are known (see Velamuri, R. et al., "A Multi-Queue Flexible Buffer Manager Architecture", IEEE Document No. 0-7803-0917-0/93) and each has inherent advantages coupled with inherent disadvantages in terms of blocking probability, utilization, throughput, and delay. What is common to all sharing methods, however, is that a mechanism is required to direct data into appropriate locations in the RAM in a desired order so that the data can be retrieved from the RAM appropriately. One such mechanism which is well known is the use of link lists which are used to manage multiple queues sharing a common memory buffer. Typically, a link list comprises bytes of data, where each byte has at least one pointer (forward and/or backward) attached to it, thereby identifying the location of the next byte of data in the queue. The link list typically includes extensive initialization and self-check procedures which are carried out by a microprocessor on a non-real-time basis. Thus, the use of standard prior art link list structures to manage multiplex queues sharing a common memory is not readily adaptable for VLSI implementation, and is likewise not particularly suited to the handling of very high speed telecommunications information where processing and handling are dictated by the data rate of the real-time telecommunications signal.

Method and apparatus for allocation and management of shared memory with data in memory stored as multiple linked lists


There is provided an ion deflector for use with a mass spectrometer for directing a flow of ions between two distinct axes of travel. The ion deflector includes an electric field inducer arranged so as to establish at least one electrostatic field capable of deflecting ions travelling substantially along a first intended path of travel so as to travel substantially along a second intended path of travel.

In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date part of common general knowledge, or known to be relevant to an attempt to solve any problem with which this specification is concerned.
Mass spectrometers are specialist devices used to measure or analyse the mass-to-charge ratio of charged particles for the determination of the elemental or molecular composition of a sample or molecule.
A number of different techniques are used for such measurement purposes. One form of mass spectrometry involves the use of an inductively coupled plasma (ICP) for generating a plasma. In this form, the plasma vaporises and ionizes the sample so that ions from the sample can be introduced to a mass spectrometer for measurement/analysis (spectrometric analysis).
As the mass spectrometer requires a vacuum in which to operate, the extraction and transfer of ions from the plasma involves a fraction of the ions formed by the plasma passing through an aperture of approximately 1 mm in size provided in a sampler, and then through an aperture of approximately 0.5 mm in size provided in a skimmer (typically referred to as sampler and skimmer cones respectively).
Guidance of the ion beam through a mass spectrometer apparatus is generally controlled via shaped electric fields provided by suitably positioned electrodes which operate at controlled voltages. Arrangements of this type are normally referred to as ion optics systems.
One example of an ion optics system is that described in U.S. Pat. No. 6,614,021 to Varian Australia. Pty Ltd. Although the arrangement described in US'021 is thought to operate adequately, there are thought to be limitations to its measurement sensitivity at some ion energy levels.


The present invention provides a bipolar compound represented by formula (I) and the derivatives thereof as a host material having excellent bipolar transporting properties for organic light-emitting diodes (OLEDs). The present invention also relates to a device including at least a layer of the bipolar compound and/or the derivatives thereof as a host material and a method of making the same.

Since the first report of phosphorescent organic light-emitting devices (PHOLEDs) by Forrest et al. in 1998, PHOLEDs have attracted much attention because they can achieve an internal quantum efficiency of 100%. Phosphorescent emitters typically have long lifetimes and diffusion lengths; however, concentration quenching and T1-T1 annihilation are normally major causes for the poor device performance when the emitter concentration is high. To solve these problems, PHOLEDs are always fabricated by doping the phosphorescent emitters into a suitable host material so as to reduce the emitter concentration. Therefore, the development of host materials is of extremely crucial for efficient electrophosphorescence.
An efficient host material should have a desirable bandgap for effective energy transfer to the guest, good carrier transporting properties for a balanced recombination of carriers in the emitting layer, energy-level matching with neighboring layers for effective charge injection, and decent thermal and morphological stabilities for extending the device's lifetime. Traditional host materials usually only have single carrier transporting property, like N,N′-dicarbazolyl-3,5-benzene (mCP) and 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ). They only have hole-transporting and electron-transporting properties, respectively. This unbalanced carrier transporting property of host materials have been shown to be detrimental to the turn-on voltage and stability of OLEDs. Thereby, recently bipolar host materials which can balance the carrier transports have aroused extensive interests.
Because bipolar molecule must contain both the p- and n-type groups, intramolecular donor-acceptor interaction will generally lower the triplet energy of the material. Therefore, recently reported bipolar hosts, like o-CzOXD and BUPH1, are mainly used in the green and red PHOLEDs. In contrast, bipolar hosts used in blue PHOLEDs are rarely reported. There are two possible regimes to obtain a bipolar blue host: either chemical groups which have extremely high triplet energies or a compound which the p-type group and n-type group are designed to be farther enough to decrease the intramolecular donor-acceptor interaction. However, the chemical groups with high triplet energies generally have small steric volumes. The bipolar compound might not have decent thermal and morphological stabilities.

Bipolar compound as a host material for organic light emitting diodes

NANO AND ADVANCED MATERIALS INSTITUTE LIMITED


The present invention relates to a volatile, residue free peroxide antimicrobial composition, which can be applied as a penetrating and durable, fine aerosol, that has superior strength with respect to decontaminating buildings infected with bacteria, fungi, virus or fungal or bacterial spores.

The present invention relates to a volatile, residue free peroxide antimicrobial composition, which can be applied as a penetrating and durable, fine aerosol, that has superior strength with respect to decontaminating buildings infected with bacteria, fungi, virus or fungal or bacterial spores.
The present invention is also directed to a process for decontaminating large man made structures and the air contained in these.
Disinfecting biologically contaminated large man-made structuresxe2x80x94as for example shopping malls, sports complexes, high rises, subway systems, factories, etc.xe2x80x94as well as the air contained in these structures is an extremely challenging undertaking and none of the presently available methods are satisfactory.
The most widely used method is fumigation with formaldehyde. Formaldehyde is a suspected carcinogenic and a potent allergen which, due to inevitable residues left after a treatment, severely limits its usefulness in structures inhabited by man.
Numerous attempts have been made to use oxidizing gases such as ozone or chlorine dioxide for decontaminating large buildings. However, the results have invariably been very disappointing. This is to some extent due to the inherent inability of gases to penetrate a porous structure within a reasonable time. In fine pores diffusion is the only way for a gas to spread, and this process is slow. Mainly, though, the failure of ozone and chlorine dioxide in building decontamination is due to the instability and extreme reactivity of these gases. They are very toxic to man and will also corrode virtually any oxidizeable material, (metals, wood, textiles, plants, plastics, etc.) Actually the major part of these gases will be consumed in unwanted oxidation reactions, that cause collateral damage, and for health and safety reasons is basically not possible to apply these gases at the levels required for efficient decontamination to take place.
From a health and environmental point of view disinfecting agents based on peroxides, such as hydrogen peroxide, peracetic acid and like, is much to be preferred. Their oxidizing strength, without being excessive, in principle is adequate for killing virtually all microbes. Unfortunately hydrogen peroxide or other peroxides are too unstable and hazardous to allow fumigating with their vapors.
High density, fine aerosols (aerosol droplet diameter less than 50 micron) of aqueous peracetic acid, hydrogen peroxide or combinations thereof, suitable for disinfecting are only sufficiently stable at 100% R.H., and the commercial fog-disinfecting methods using peroxides are only suitable for confined spaces where all materials and equipment are corrosion resistant or protected.
The objective of said invention is to provide an antimicrobial composition that can be applied at ambient conditions as a high density, durable fine aerosol having superior disinfecting strength with respect to microbes and spores thereof adhered to inanimate surfaces as well as with respect to airborne microbes and microbial spores, such an aerosol being imminently suitable for emergency decontamination of buildings and spaces infected with hazardous microbes or spores thereof.
As a result of extensive research, I have found that a mixture of hydrogen peroxide and tert-butyl hydroperoxide in propylene glycol or other water compatible glycols can be converted to a high density, durable fine aerosol, using conventional thermofogging equipment (see below), without appreciable loss of peroxide activity through thermal decomposition, and that such aerosols manifest unexpected high disinfecting strength with respect to microorganisms including fungal and bacterial spores without causing staining, corrosion or irritating odors. The use of a combination of hydrogen peroxide and tert-butyl hydroperoxide for bleaching of pulp has been described in U.S. Pat. No. 3,645,840. However, it is by no means obvious how the disclosures of U.S. Pat. No. 3,645,840 can be applied to an aerosol process for disinfecting buildings. U.S. Pat. No. 5,147,884 describes antimicrobial composition containing tert-butyl hydroperoxide and a monophenylglycol ether.
In the disinfecting method according to this invention the peroxide antimicrobial agent is converted into a fine aerosol using various types of xe2x80x9cthermofoggersxe2x80x9d, such as for example a pulsejet fogger or an electrical fogger with a flash heating system. Examples of pulsejet thermofoggers are xe2x80x9cPatriotxe2x80x9d and xe2x80x9cBlack Hawkxe2x80x9d manufactured by Curtis Dynafog Corporation, Ltd., Indianapolis, and an example of a suitable electrical thermofogger is xe2x80x9cFogmaxxe2x80x9d manufactured by CITC, Lynnwood, Wash. Normally the high temperature in thermofoggers will destroy any peroxide. However, as mentioned above, I have discovered combinations of peroxides and carriers that can resist the high temperatures encountered in thermofoggers, making this ideal aerosol technique available to generate fine, high density, durable aerosols of peroxides. The fine aerosol produced in this manner will spread much like a gas, which makes it ideal for decontamination of large structures as well as inaccessible areas of buildings. However, in contrast to a gaseous agent, once an aerosol according to this invention has settled on a surface, it behaves like a liquid, that is, the agent can be transported by capillary action deep into a porous material, which is impossible with ozone or chlorine dioxide. The peroxide disinfecting method according to this invention kills mold, bacteria and fungi as well as spores thereof. The same oxidation reaction also degrades it and neutralizes the odor compounds from mold, fungi and bacteria (MVOC).
Another advantage of the disinfecting method according to this invention is that airborne microbes are disinfected with the same efficiency as those adhered to surfaces. Furthermore airborne particulate matter is removed from treated air spaces through agglomeration with the aerosol droplets, leaving the treated air virtually free from microbes and their spores.
The present invention provides a safe and effective method of sanitizing surfaces and ambient air by removing, reducing or retarding the growth of pathogenic microorganisms and molds without the use of substances that are toxic to humans and without leaving any permanent residue.
As the peroxide used as component (A) of said invention, commercially available hydrogen peroxide aqueous solutions can be used favorably.
Next, the volatile, organic peroxide used as component (B), is commercially available t-butyl hydroperoxide.
The content of the hydrogen peroxide used as component (A) in the biocidal composition is generally 0.5-60 wt %, preferably 0.5-30 wt %, and more preferably 0.5-20 wt %. For practicality, 3-20 wt % is most favorable. The content of t-butyl hydroperoxide, which is component (B), is 0.5-60 wt %, preferably 0.5-30 wt %, and more preferably 0.5-10 wt %. For practicality, 3-10 wt % is most favorable.
If component (A) or (B) is lower than said range, the disinfecting action is low, when component (A) or (B) is greater than said range, the product becomes difficult to handle as a biocidal composition.
The solvent carrier (C) of the biocidal composition in said invention is important for thermal stability, for aerosol forming properties as well as for obtaining high disinfecting strength. After extensive research I have found that mixtures of water and a low volatile, water compatible glycol or glycol ether are preferable, and most preferable are mixtures of propylene glycol and water where the content of propylene glycol in water is 10-90 wt %.
The biocidal composition of the present invention is normally manufactured by dissolving hydrogen peroxide (A) and t-butyl hydroperoxide (B) in a mixture of water and propylene glycol (C). The content of propylene glycol (C) used in the biocidal composition in said invention is selected from a range of 5-99 wt %, preferably 50-95 wt %, and more preferably 60-90 wt %.
In the biocidal composition of the present invention, it is preferable to add a surfactant. As the surfactant, cationic surfactants such as aryl-alkyl or dialkyl dimethyl ammonium halides, nonionic surfactant such as polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, amine oxides, etc., and anionic surfactants such as soaps, alkyl sulfates, and alkylbenzenesulfonates, etc., can be utilized. It is preferable for the quantity of the surfactant added to be 0.1-10 wt % in the biocidal composition. By the addition of a surfactant, it is possible to assist in the penetration of the biocidal composition with respect to the bacterial bio-film, mold or spore coating and to enhance the biocidal effect.
The biocidal composition of the present invention is applied as a fine aerosol using thermofogging equipment described above, and it is possible to disinfect spores, bacterial bio-films or molds effectively by contacting with said fine aerosol.
By thermal fogging, the biocidal composition of this invention is dispersed in 10-20 micron particle sizes and the treated building is kept closed for a minimum of twenty-four (24) hours for treatment to occur.
No rinsing of treated surfaces is required after or prior to application of the disinfecting aerosol according to this invention.
Typical bacteria which can be disinfected with the composition of this invention include: staphylococcus aureus, staphylococcus pyogenes, streptococcus hemolyticus, streptococcus dysgalactiae, mycobacterium tuberculosis, salmonella typhosa, salmonella typhimurium, salmonella pullorum, hemophilus parasuis, clostridium perfringens, mycoplasma synoviae, mycoplasma hyopneumoniae, pasteurella multocida, klebsiella pneumoniae, staphylococcus epidermis, streptococcus agalactiae, streptococcus fecalis, listeria monocytogenis, mycobacterium tuberculosis, salmonella choleraesuis, salmonella enteritidis, pseudomonas aeruginosa, clostridium tetani, diplococcus pneumoniae, mycoplasma gallisepticum, escherichia coli, pasteurella hemolytica, alcaligenes faecalis, salmonella gallinarum, salmonella arizonae, salmonella schotimuelleri, staphylococcus hyicus, streptococcus pyogenes, haemophilus parasuis; and, bordetella bronchiseptica.
Fungus types, which may be disinfected by the composition of this invention, include: aspergillus fumigatus, aspergillus glacus, aspergillus nidulans, aspergillus flavus, aspergillus niger, fusarium solani; and penicillium variable.
Spore types, which may be disinfected by the composition of this invention, include: Bacillus anthracis, B., and (bacterial spores) and Stachybotrys, Aspergillus, Penicillium, Trichoderma and Alternaria spp. (fungal spores).
Viruses which are disinfected by this composition include: Adenoviridae (Egg Drop Syndrome), Herpetoviridae (Infectious Bovine), Rhinotracheitis (Aujeszky""s Disease), Feline Herpes, Iridoviridae (African Swine Fever), Parvoviridae, (Canine Parvovirus), Poxviridae Pseudo (Cowpox), Coronaviridae (Transmissible Gastro-Enteritis), Avian Infectious Bronchitis, Canine Coronavirus, Orthomyxoviridae (Avian Influenza), Paramyxoviridae (Newcastle Disease), Distemper, Picornaviridae (Swine Vesicular Disease), Foot and Mouth Disease, Reoviridae Gumboro (IBD), Retroviridae (Maedi and Visna), AIDS.

Disinfecting and sporocidal composition and process for decontaminating buildings


A cyclone dust collecting apparatus comprises a deformable contaminants counterflow prevention member mounted to within 10 to 12 mm of the inner surface of the cyclone dust collecting apparatus. The deformable contaminants counterflow prevention member is soft enough to be elastically transformed to allow large contaminants to be drawn past it and drop into a dust collecting apparatus yet resilient enough so that it returns to its original shape after a large contaminant is passed.

Generally, a cyclone dust separating apparatus, also known as a cyclone dust collecting apparatus, draws in contaminant-laden air from a surface by negative air pressure generated by a vacuum source in a vacuum cleaner body. As air flows through a cyclone dust collecting apparatus, the air generates a rotating or cyclonic air stream or vortex in the cyclone dust separating apparatus that causes suspended dirt particles to be centrifugally separated from the air.
FIG. 1 is a schematic view of cyclone dust collecting apparatus for a vacuum cleaner. Reference numerals 1, 2 denote a cyclone dust collecting apparatus and a cleaner body, respectively. Reference numerals 10, 20 and 30 denote a cyclone body, a contaminants-collecting receptacle and a grill, respectively.
As shown in FIG. 1, the cyclone body 10 comprises an air intake port, also referred to herein as an inflow port 11 and an air outlet or exhaust port, referred to herein as an air outflow port 12. The air inflow port 11 is connected with an air path or duct 3 that is fluidly communicated with an inlet of a suction brush (not shown) of the cleaner body 2 when the cyclone dust collecting apparatus 1 is mounted to the cleaner body 2. The air outflow port 12 is connected with an air discharging port (not shown) at an upside of the cyclone body 10. The air outflow port 12 is connected with an air discharging path fluidly communicated with a motor-driven vacuum source in a motor chamber 5 in the cleaner body 2.
Dust and contaminant-laden air flowing into a vacuum cleaner via the suction brush streams into the cyclone body 10 through the air inflow path 3 and the air inflow port 11 of the cleaner body 2, tangentially to the cyclone body wall. Because the air flows in tangentially, a rotating stream, which is also known as a cyclone or vortex, is generated in the cyclone body 10. Dust and contaminants are separated from the rotating stream by a centrifugal force, cleaned air is discharged to the outside through the air outflow port 12, and an air discharge path 4 and the motor driving chamber 5 of the cleaner body 2.
The contaminant collection receptacle 20 is detachably engaged with a bottom portion of the cyclone body 10 and collects dust and contaminants centrifugally separated from air by a rotating stream in the cyclone body 10.
A grill 30 is mounted at an entrance of the air outflow port 12 in the cyclone body 10 to prevent the separated dust and contaminants from counterflow to the cleaner body 10 through the air outlet port 12. The grill 30 comprises a grill body 31, a plurality of paths 32 arranged around the outer circumference of the grill body 31 to fluidly communicate with the air outflow port 12 and a counterflow prevention port 33, a function of which is to prevent collected contaminants from counterflowing and escaping the cyclone dust collecting apparatus 10.
The efficiency of a cyclone dust collecting apparatus depends in part on the distance d between the counterflow prevention part 33 and the cyclone body 10. That is, if an end of the counterflow prevention part 33 is arranged to be close to an inner circumference of the cyclone dust collecting apparatus, filtering effectiveness can be improved because it can prevent contaminants collected in the contaminants collection receptacle 20 from counterflow. However, large contaminants are sometimes trapped or caught such that they may obstruct generation of rotating stream or block the air discharge path.
On the other hand, if the counterflow prevention part 33 is arranged too far from the inner circumference of the cyclone body 10, large contaminants can be easily collected in the contaminants collection receptacle 20, however, large contaminants collected in the contaminants collection receptacle 20 may be affected by the rotating stream in the cyclone body 10 such that they counterflow from a bottom surface of the contaminants collection receptacle 20 and are trapped or caught by the grill 30, and as a result, dirt collection of the cyclone dust collecting apparatus 1 may decrease.

Cyclone dust collecting apparatus having contaminants counterflow prevention member


A differential circuit is provided, which makes it possible to realize an ideal linear behavior with respect to an input signal. This circuit includes a voltage-current converter, a current-voltage converter, and a triple-tail cell. The voltage-current converter converts an initial input voltage to generate first and second differential output currents. The current-voltage converter converts the first and second output currents to generate first and second output voltages. The triple-tail cell has first, second, and third transistors driven by a common constant current. The first and second transistors form a differential pair. The first and second output voltages are differentially applied across input ends of the differential pair. The third transistor serves as a bypass transistor for the common constant current. An input end of the third transistor is applied with a bias voltage. An output current of the differential circuit is derived from output ends of the differential pair. This circuit is preferably used for a multiplier.

1. Field of the Invention
The present invention relates to a differential circuit and a multiplier and more particularly, to a differential circuit having an ideal linear behavior with respect to an input signal, and a multiplier using the differential circuit, which is preferably formed on a semiconductor integrated circuit (IC).
2. Description of the Prior Art
A conventional differential circuit using a logarithmic converter is shown in IEEE Journal of Solid-State Circuits, Vol. SC-3, No.4, December 1968, pp 365-373, entitled "A Precise Four-Quadrant Multiplier with Subnanosecond Response", which was written by Barrie Gilbert.
The logarithmic conversion of the converter is realized on the basis of the following fact.
Supposing that the base-width modulation (i.e., the Early voltage) is ignored, the collector current I.sub.C and the base-to-emitter voltage V.sub.BE typically has the following relationship (1). ##EQU1##
In the equation (1), I.sub.s is the saturation current of the transistor, and V.sub.T is the thermal voltage defined as EQU V.sub.T kT/q (2)
where k is the Boltzmann's constant, T is absolute temperature in degrees Kelvin, and q is the charge of an electron.
It is seen from the equation (1) that the logarithmic conversion is able to be realized by the use of the above relationship (1).
The multiplier disclosed in the above article is shown in FIG. 1, which corresponds to the circuit of FIG. 8 in the article. In FIG. 1, the reference numeral 61 indicates the well-known Gilbert multiplier cell, the reference numeral 62 indicates a logarithmic converter as an input circuit for the multiplier cell 61, the reference numeral 65 indicates emitter-degeneration resistors, and the reference numeral 85 indicates load resistors of the multiplier cell 61.
The logarithmic conversion of the input circuit 62 is performed by the use of the equation (1). Specifically, two bipolar transistors 71 and 72 constitute an emitter-coupled pair, and two diode-connected bipolar transistors 73 and 74 serve as loads for the respective transistors 71 and 72. A differential input voltage X is applied across bases of the transistors 71 and 72. Two output voltages of the input circuit 62 are derived from the collectors of the transistors 71 and 72.
the collector current and the base-to-emitter voltage have the above relationship (1) and therefore, the two output voltages are equal to the logarithmically converted voltages of the input voltage X, respectively. These two output voltages are applied across bases of bipolar transistors 77,80 and 78,79 of the multiplier cell 61.
An input voltage Y is differentially applied across bass of bipolar transistors 75 and 76.
The multiplication result X.multidot.Y of the input voltages X and Y is differentially derived through the load resistors 85.
On the other hand, the combination of the Gilbert multiplier cell and a predistortion circuit was created by B. Gilbert, which has been termed the "Gilbert multiplier" and includes two "Gilbert gain cells". A differential circuit serving as the Gilbert gain cell is shown in FIG. 2.
As shown in FIG. 2, bipolar transistors Q101 and Q102 whose emitters are coupled together through an emitter resistor (resistance :R) form a differential pair of an input circuit. Two diode-connected bipolar transistors Q103 and Q104 constitute loads of the differential pair of the transistors Q101 and Q102. The transistors Q101 and Q102 are driven by constant currents I.sub.0, respectively.
Bipolar transistors Q105 and Q106 whose emitters are coupled together form a differential pair of the Gilbert gain cell. The transistors Q105 and Q106 are driven by a common constant current I.sub.1.
An input voltage V.sub.i is applied across bases of the transistors Q101 and Q102. Collector currents of the transistors Q101 and Q102 vary according to the change of the input voltage V.sub.i. The change of the collector currents are derived through the load transistors Q103 and Q104 to thereby generate a logarithmically-compressed output voltage V.sub.o between the collectors of the transistors Q101 and Q102.
The logarithmically-compressed output voltage V.sub.o ' is then applied across bases of the transistors Q105 and Q106. The differential pair of the transistors Q105 and Q106 amplifies voltage V.sub.o to generate a differential output current .DELTA.I.sub.C between collectors of the transistors Q105 and Q106.
As described above, in the Gilbert gain cell, the diode-connected transistors Q103 and Q104 serving as the loads for the transistors Q101 and Q102 constitute a predistortion circuit for the transistors Q105 and Q106.
In the differential circuit of FIG. 2, when a current flowing through the emitter resistor of the transistors Q101 and Q102 and base-to-emitter voltages thereof are defined as i, V.sub.BE1 and V.sub.BE2, respectively, the following equation (3) is established. EQU V.sub.t =V.sub.BE1 -V.sub.BE2 +Ri (3)
Here, supposing that (Ri>>V.sub.BE1 -V.sub.BE2) is established, the following equation (4) is obtained. ##EQU2##
The current if lows through the load transistors Q103 and Q104 as a differential current. The inter-terminal voltage V.sub.o of the diode-connected transistors Q103 and Q104 is equal to a voltage obtained by logarithmically compressing the input voltage V.sub.i. The output voltage C.sub.o of the differential pair of the transistors Q101 and Q102 is then exponentially expanded and amplified by the differential pair of the transistors Q105 and Q106, thereby generating the differential output current .DELTA.UI.sub.C. The differential output current .DELTA.I.sub.C caries proportionally to the current i and the input voltage V.sub.i.
With the conventional differential circuit of FIG. 2, since an approximation is performed by the use of the equation (4), a problem that the differential output current .DELTA.I.sub.C does not vary completely proportional to the differential input voltage V.sub.i occurs. In other words, the conventional differential circuit of FIG. 2 has a problem that it does not perform a completely (or, ideal) linear behavior with respect to the differential input voltage V.sub.i.


Genes encoding herpes simplex virus type 2 (HSV-2) proteins were cloned into eukaryotic expression vectors to express the encoded proteins in mammalian muscle cells in vivo. Animals were immunized by injection of these DNA constructs, termed polynucleotide vaccines or PNV, into their muscles. In a DNA titration, it was found that a single immunization of ≧0.5 μg of (one) PNV, gave >90% seroconversion by ten weeks post immunization. Immune antisera neutralized both HSV-2 and HSV-1 in cell culture. When animals were challenged with HSV-2, significant (p<0.001) protection from lethal infection was achieved following PNV vaccination. DNA constructs may be full-length, truncated and/or mutated forms and may be delivered along or in combination in order to optimize immunization and protection from HSV infection.

A major obstacle to the development of vaccines against viruses, particularly those with multiple serotypes or a high rate of mutation, against which elicitation of neutralizing and protective immune responses is desirable, is the diversity of the viral external proteins among different viral isolates or strains. Since cytotoxic T-lymphocytes (CTLs) in both mice and humans are capable of recognizing epitopes derived from conserved internal viral proteins [J. W. Yewdell et al., Proc. Natl. Acad. Sci. (USA) 82, 1785 (1985); A. R. M. Townsend, et al., Cell 44, 959 (1986); A. J. McMichael et al., J. Gen. Virol. 67, 719 (1986); J. Bastin et al., J. Exp. Med. 165, 1508 (1987); A. R. M. Townsend and H. Bodmer, Annu. Rev. Immunol. 7, 601 (1989)], and are thought to be important in the immune response against viruses [Y.-L. Lin and B. A. Askonas, J. Exp. Med. 154, 225 (1981); I. Gardner et al., Eur. J. Immunol. 4, 68 (1974); K. L. Yap and G. L. Ada, Nature 273, 238 (1978); A. J. McMichael et al., New Engl. J. Med. 309, 13 (1983); P. M. Taylor and B. A. Askonas, Immunol. 58, 417 (1986)], efforts have been directed towards the development of CTL vaccines capable of providing heterologous protection against different viral strains.
It is known that CTLs kill virally-infected cells when their T cell receptors recognize viral peptides associated with MHC class I and or class II molecules. These peptides can be derived from endogenously synthesized viral proteins, regardless of the protein's location or function within the virus. By recognition of epitopes from conserved viral proteins, CTLs may provide heterologous protection.
Many infectious disease causing agents can, by themselves, elicit protective antibodies which can bind to and kill, render harmless, or cause to be killed or rendered harmless, the disease causing agent and its byproducts. Recuperation from these diseases usually results in long-lasting immunity by virtue of protective antibodies generated against the highly antigenic components of the infectious agent.
Protective antibodies are part of the natural defense mechanism of humans and many other animals, and are found in the blood as well as in other tissues and bodily fluids. It is the primary function of most vaccines to elicit protective antibodies against infectious agents and/or their byproducts, without causing disease.
Most efforts to generate CTL responses have either used replicating vectors to produce the protein antigen within the cell [J. R. Bennink et al., ibid. 311, 578 (1984); J. R. Bennink and J. W. Yewdell, Curr. Top. Microbiol. Immunol. 163, 153 (1990); C. K. Stover et al., Nature 351, 456 (1991); A. Aldovini and R. A. Young, Nature 351, 479 (1991); R. Schafer et al., J. Immunol. 149, 53 (1992); C. S. Hahn et al., Proc. Natl. Acad. Sci. (USA) 89, 2679 (1992)], or they have focused upon the introduction of peptides into the cytosol [F. R. Carbone and M. J. Bevan, J. Exp. Med. 169, 603 (1989); K. Deres et al., Nature 342, 561 (1989); H. Takahashi et al., ibid. 344, 873 (1990); D. S. Collins et al., J. Immunol. 148, 3336 (1992); M. J. Newman et al., ibid. 148, 2357 (1992)]. Both of these approaches have limitations that may reduce their utility as vaccines. Retroviral vectors have restrictions on the size and structure of polypeptides that can be expressed as fusion proteins while maintaining the ability of the recombinant virus to replicate [A. D. Miller, Curr. Top. Microbiol. Immunol. 158, 1 (1992)], and the effectiveness of vectors such as vaccinia for subsequent immunizations may be compromised by immune responses against vaccinia [E. L. Cooney et al., Lancet 337, 567 (1991)]. Also, viral vectors and modified pathogens have inherent risks that may hinder their use in humans [R. R. Redfield et al., New Engl. J. Med. 316, 673 (1987); L. Mascola et al., Arch. Intern. Med. 149, 1569 (1989)]. Furthermore, the selection of peptide epitopes to be presented is dependent upon the structure of an individual's MHC antigens and, therefore, peptide vaccines may have limited effectiveness due to the diversity of MHC haplotypes in outbred populations.
Benvenisty, N., and Reshef, L. [PNAS 83, 9551-9555, (1986)] showed that CaCl2 precipitated DNA introduced into mice intraperitoneally (i.p.), intravenously (i.v.) or intramuscularly (i.m.) could be expressed. The intramuscular (i.m.) injection of DNA expression vectors in mice has been demonstrated to result in the uptake of DNA by the muscle cells and expression of the protein encoded by the DNA [J. A. Wolff et al., Science 247, 1465 (1990); G. Ascadi et al., Nature 352, 815 (1991)]. The plasmids were shown to be maintained episomally and did not replicate. Subsequently, persistent expression has been observed after i.m. injection in skeletal muscle of rats, fish and primates, and cardiac muscle of rats [H. Lin et al., Circulation 82, 2217 (1990); R. N. Kitsis et al., Proc. Natl. Acad. Sci. (USA) 88, 4138 (1991); E. Hansen et al., FEBS Lett. 290, 73 (1991); S. Jiao et al., Hum. Gene Therapy 3, 21 (1992); J. A. Wolff et al., Human Mol. Genet. 1,363 (1992)]. The technique of using nucleic acids as therapeutic agents was reported in WO90/11092 (Oct. 4, 1990), in which naked polynucleotides were used to vaccinate vertebrates.
Recently, the coordinate roles of B7 and the major histocompatibility complex (MHC) presentation of epitopes on the surface of antigen presenting cells in activating CTLs for the elimination of tumors was reviewed [Edgington, Biotechnology 11, 1117-1119, 1993]. Once the MHC molecule on the surface of an antigen presenting cell (APC) presents an epitope to a T-cell receptor (TCR), B7 expressed on the surface of the same APC acts as a second signal by binding to CTLA-4 or CD28. The result is rapid division of CD4+ helper T-cells which signal CD8+ T-cells to proliferate and kill the APC.
It is not necessary for the success of the method that immunization be intramuscular. Thus, Tang et al., [Nature, 356, 152-154 (1992)] disclosed that introduction of gold microprojectiles coated with DNA encoding bovine growth hormone (BGH) into the skin of mice resulted in production of anti-BGH antibodies in the mice. Furth et al., [Analytical Biochemistry, 205, 365-368, (1992)] showed that a jet injector could be used to transfect skin, muscle, fat, and mammary tissues of living animals. Various methods for introducing nucleic acids was recently reviewed [Friedman, T., Science, 244, 1275-1281 (1989)]. See also Robinson et al., [Abstracts of Papers Presented at the 1992 meeting on Modern Approaches to New Vaccines, Including Prevention of AIDS, Cold Spring Harbor, p92], where the im, ip, and iv administration of avian influenza DNA into chickens was alleged to have provided protection against lethal challenge. Intravenous injection of a DNA: cationic liposome complex in mice was shown by Zhu et al., [Science 261, 209-211 (Jul. 9, 1993); see also WO93/24640, Dec. 9, 1993] to result in systemic expression of a cloned transgene. Recently, Ulmer et al., [Science 259, 1745-1749, (1993)] reported on the heterologous protection against influenza virus infection by injection of DNA encoding influenza virus proteins.
Wang et al., [P.N.A.S. USA 90, 4156-4160 (May, 1993)] reported on elicitation of immune responses in mice against HIV by intramuscular inoculation with a cloned, genomic (unspliced) HIV gene. However, the level of immune responses achieved was very low, and the system utilized portions of the mouse mammary tumor virus (MMTV) long terminal repeat (LTR) promoter and portions of the simian virus 40 (SV40) promoter and terminator. SV40 is known to transform cells, possibly through integration into host cellular DNA. Thus, the system described by Wang et al., is wholly inappropriate for administration to humans, which is one of the objects of the instant invention.
WO 93/17706 describes a method for vaccinating an animal against a virus, wherein carrier particles were coated with a gene construct and the coated particles are accelerated into cells of an animal.
Recent efforts to develop subunit vaccines for herpes simplex virus (HSV) have focused on novel expression and presentation of viral antigens; especially the viral glycoproteins. [for review see Burke, R. L., 1993, Sem. In Virol., 4, pp.187-197] Recombinant HSV glycoproteins expressed by a variety of systems including yeast (Kino., Y. C. et al., 1989, Vaccine, 7, pp.155-160), insect cells (Ghiasi, H. et al., 1991, Arch.Virol., 121, pp.163-178), and mammalian cells (Burke, R. L., 1991, Rev.Infect.Dis., 13 S906-S911; Lasky, L. A., 1990, J.Med.Virol., 31, pp.59-61) have been shown to elicit protective immunity in animal models. Clinical trials of a recombinant HSV-2 glycoprotein D (gD) produced in Chinese hamster ovary cells have shown that the vaccine induces an antibody response in naive individuals and stimulates the pre-existing response in both HSV-1 and HSV-2 seropositive individuals. (Straus, S. E. et al., 1993, J.Infect.Dis., 167, pp.1045-1052)
An alternate approach to subunit vaccination has been the use of live virus vectors for delivery of HSV antigens. Vaccinia-HSV recombinants expressing gD (Aurelian, L. et al., 1991, Rev.Infect.Dis., 13, S924-S930; Rooney, J. F. et al., 1991, Rev.Infect.Dis., 13, S898-S903; Wachsman, M. et al., 1992, Vaccine, 10, pp.447-454) gB (Rooney, J. F. et al., supra), gL and gH (Browne, H. et al., 1993, J.Gen.Virol., 74, pp.2813-2817) have successfully protected animals from HSV challenge. Vaccination by infection with recombinant adenovirus expressing HSV gB elicits a protective immune response in mice. (Ghiasi, H., supra; McDermott, M. R., 1989, Virology, 169, pp.244-247) It is well documented that anti-gD antibodies can protect against HSV infection whether elicited by immunization with native protein (Long, D. et al., 1984, Infect.Immun., 43, pp.761-764) recombinantly expressed protein (Burke, R. L., supra; Stanberry, L. R. et al., 1987, J.Infect.Dis., 155, pp.914-920; Straus, S.E., supra) peptides derived from gD (Eisenberg, R. J. et al., 1985, J.Virol., 56, pp.1014-1027) or transferred passively (Dix, R. D. et al., 1981, Infect.Immun., 34, pp.192-199; Ritchie, M. H. et al., 1993, Investigative Ophthalmology and Visual Sciences, 34, pp.2460-2468).
Studies by Wolff et al. (supra) originally demonstrated that intramuscular injection of plasmid DNA encoding a reporter gene results in the expression of that gene in myocytes, at and near the sight of injection. Recent reports demonstrated the successful immunization of mice against influenza by the injection of plasmids encoding influenza A hemagglutinin (Montgomery, D. L. et al., 1993, Cell Biol., 12, pp.777-783), or nucleoprotein (Montgomery, D. L. et al., supra; Ulmer, J. B. et al., 1993, Science, 259, pp.1745-1749). The first use of DNA immunization for a herpes virus has been reported (Cox et al., 1993, J.Virol., 67, pp.5664-5667). Injection of a plasmid encoding bovine herpesvirus 1 (BHV-1) glycoprotein g IV gave rise to anti-g IV antibodies in mice and calves. Upon intranasal challenge with BHV-1, immunized calves showed reduced symptoms and shed substantially less virus than controls. The ability of HSV glycoprotein D to elicit a protective immune response in mice (Long, D. et al., supra) and guinea pigs (Stanberry, L. R. et al., supra; Stanberry, L. R. et al., 1989, Antiviral.Res., 11, pp.203-214) is well documented.


A sound reproduction device such as a radio receiver or a cellular phone includes an antenna, a control unit and a speaker. The control unit determines whether a radio wave receiving condition is satisfactory. The receiving condition is represented by field strength of the radio wave or a degradation of a sound signal in the radio wave. If the receiving condition is not satisfactory, the control unit adds an acoustic effect to the sound signal thereby to notify listeners of degradation of receiving condition. The acoustic effect may be a changing of sound image localization, a changing of a frequency characteristic and a changing of a reverberation characteristic. The acoustic effect is stopped for a specified period after the acoustic effect is added, even when the receiving condition is not satisfactory.

In a conventional sound reproduction device, which receives sound signals transmitted via analog radio communication, noise level increases in the reproduced sounds as radio wave propagation condition worsens. Listeners therefore may recognize degree of degradation of the radio wave propagation condition. The recent digital communication technology, software demodulation technology, etc. improves quality of reproduced sounds. As a result, sounds are reproduced without noises if the radio wave propagation path is in a condition acceptable to reproduce sounds. Sounds sometimes break up if the radio wave propagation path is not in the acceptable condition. In the case that the sound reproduction device is a mobile type like a cellular phone, the radio wave propagation condition is likely to worsen if the device is moved into a weak electric field area. Therefore, it is desired to notify users of degrading propagation condition so that quality of the sound reproduction is not degraded.
In cellular phones, as disclosed in JP-A-3-192129, alarm sounds are added to the sounds when the radio wave propagation condition degrades in the middle of communication. Alternatively, as disclosed in JP-A-8-139663 and JP-A-11-122197, pseudo noises varying with the level of degradation of the propagation condition are added to the sounds.
In sound reproduction devices like a radio receivers that reproduce voice sounds or music sounds, the alarm sounds or pseudo noises will lower the reproducibility of sounds and artistic quality of music.


A memory system comprising a semiconductor memory for storing digital data, said memory being connectable to a control device in order to receive an address signal and to make data selected through the output-available address signal. The system is characterised in that it comprises a generating circuit for activating a wait signal to be forwarded to the control device during reading operations in such a way as to indicate the non-availability of the data to be read. The generating circuit is such to deactivate the wait signal, in such a way as to indicate the availability of the data to be read, following a waiting time interval correlated with an effective access time for said memory.

Non volatile memories, such as for example, flash memories, are associated with appropriate control devices which manage the various possible operations to be performed on the memory itself such as, writing, cancellation, or reading. Possible examples of such control devices are: microprocessors, microcontrollers and DSPs (Digital Signal Processors).
With particular reference to reading operations, the data-transfer speed between the memory in which the data are stored and the control device thereof, is frequently of fundamental importance. The transfer speed, associated with the memory access time, is a parameter which assumes an ever greater importance with increasing memory dimensions.
The known art has proposed different methodologies which seek to increase the transfer speed with respect to that which is observed in the case of random access.
One of these methodologies is the page mode technique which, as is known, provides asynchronous access, i.e. not directly associated with the memory system timing signal. According to this technique, access to the memory for the reading of a word causes the reading of a pre-fixed number of words which constitute a memory page. The first word read is made available following a first pre-fixed time interval (for example, equal to 120 ns), whilst the reading of another word belonging to the same page is completed following a second time interval, shorter than the first, for example, equal to 25 ns. Indeed, this second reading is a selection from within the same page to which there has already been access. If the subsequent word to be read does not belong to the same page, it will be accessed, following the first time interval, on a new page.
Another access technique is that which is denominated as burst mode which, contrary to the former, is a synchronous type, i.e. the timings of the input and output signals are related to a clock signal generated by the system and provided to the memory. Such technology envisages that the access occurs through the transfer of a sequence of words. In order to gain access to the first word it is necessary to wait for M latency cycles in order to allow the memory to execute the reading of N words. The subsequent data appears as output, subsequent to the first word, regulated by the clock signal.
Both page mode technique and the burst mode technique have a drawback associated with the rigidity of the access methodologies. Such rigidity, which is more significant for the second technique, results in the need to use memory control devices which are based on the peculiar characteristics of each of those methods and which in certain cases must envisage the management of additional signals, otherwise not strictly necessary. Furthermore, the known modalities of access do not allow the full exploitation of the possibilities offered by the memories available today.

Memory system comprising a semiconductor memory


A debugging method for a Universal Serial Bus (USB) device includes: receiving input information of a terminal through a Human Interface Device (HID) device; when report ID of the input information is a serial port ID, transmitting the input information to a buffer of a virtual serial port Teletype (TTY) device; and extracting the input information of the terminal from the buffer of the virtual serial port TTY device, executing a shell command on the input information, and returning execution result to the terminal through an original path. The method uses a USB interface to implement a HID device, thereby realizing drive-free execution. In addition, use of the endpoint of the HID device can save endpoints needed for additional debugging and driving.

Due to the plug-and-play feature of USB itself, more and more peripheral accessories have been made into with USB interfaces, and the USB ports of hosts such as personal computers (PCs), tablets are used to energize, identify and operate the accessories.
What follows is the need for debugging USB devices. The traditional debugging methods are as follows:
1) leading out serial cables on the USB devices, and using console mechanism of the LINUX (A set of free-use and free-spread UNIX-like operating system, which is a multi-user, multi-tasking, multi-threading and multi-CPU operating system based on POSIX and UNIX. It can run major UNIX tool software, applications and network protocols) to debug the devices; and
2) using Android Debug Bridge (ADB) debugging method of ANDROID (a LINUX-based free and open-source operating system).
The disadvantages of method 1) are:
hardware external serial cable is required. During the sales phase of the devices, the serial cable will be removed, and the device cannot be debugged at this time; and
hackers can obtain important information about the device by viewing the print information through an external serial port, and may even crack the password mechanism of the serial port to obtain system debugging permission.
The disadvantages of method 2) are:
it is needed to install ADB driver on the hosts such as PCs to use the ADB function normally, and the configuration is a little more cumbersome; and
the ADB function requires two additional bulk endpoints in order to implement the ADB GADGET function, which requires more endpoint resources of the USB devices.
During the sales phase of the devices, it is not expected that the device will enumerate one more ADB device, which is not conducive to the use of the user, and also has security risks.

Debugging method for USB device and USB device

YEALINK (XIAMEN) NETWORK TECHNOLOGY CO., LTD.


A device, method and system for calculating, estimating, or monitoring the blood pressure of a subject. A first signal representing heart activity of a subject may be received. A plurality of second signals representing time-varying information on at least one pulse wave of the subject may be received from a plurality of body locations of the subject. A first feature of the first signal may be identified. For each of the plurality of second signals, a second feature may be identified. A pulse transit time based on a difference of the first feature and at least one of the second features may be computed. A blood pressure of the subject may be calculated according to a model based on the computed pulse transit time. The model may include a compensation term relating to the plurality of second signals or the second features thereof.

A traditional blood pressure measurement system, also called sphygmomanometers, employs Korotkoff sounds or an oscillometric method to determine blood pressure based on the relationship of the external pressure and magnitude of arterial volume pulsations. Such a traditional blood pressure measurement system involves an inflatable cuff to restrict blood flow. Various cuff-based methods work discontinuously with an interval of some minutes or longer between consecutive measurements. Currently, ambulatory blood pressure measurement and home blood pressure measurement are recommended by professional societies for hypertension management and cardiovascular risk prediction. However, such intermittent blood pressure measurements cannot capture the dynamic state of cardiovascular system throughout a day or even longer time period. Continuous and non-invasive blood pressure monitoring may allow the investigation of transient changes in blood pressure and thus may give insights into mechanisms of blood pressure control. There is a need for a system and method to monitor blood pressure continuously in a non-invasive and cuffless way with certain accuracy.

System and method for physiological parameter monitoring


A fiber optic data transmission system and method are provided comprising a laser diode, an attenuating and focusing lens, and an optical fiber. The method of operating the system attenuates laser diode radiation outputted during operation. The system operates by application of the input driving current to the laser diode in a manner which increases the laser diode extinction ratio. The increased laser diode power output associated with operation at a higher extinction ratio is attenuated by the lens to a safe operating level. Increasing the laser diode extinction ratio significantly increases the system's signal-to-noise ratio and thereby reduces the bit error rate associated with the data transmitted over the optical fiber, while the attenuation of the laser diode output radiation allows operation within prescribed safety limits.

Fiber optic data transmission systems or links are used in certain telecommunications networks to transmit data over optical fibers between digital electronic devices. A fiber optic link offers many advantages over conventional electrical cable transmission of data, including faster transmission rates, increased information carrying capability, longer link distance, and lower cost. Typically these data transmission systems comprise a fiber optic transmitter such as a solid state light-emitting device, and an optical fiber for carrying the digital output of the fiber optic transmitter.
Solid state light-emitting devices commonly used in fiber optic data transmission systems include light-emitting diodes (LEDs) and laser diodes. An LED is a relatively low-power optical source which operates at a lower data transmission rate than does a laser diode due to a spectral output which is not suitable for high speed data transmission. For applications which require high-speed data transmission or which cover long distances, a laser diode is preferred as the optical transmitter. Typically, the full output of the laser diode is applied directly or through a focusing lens to the optical fiber.
The use of a laser diode in combination with an optical fiber, however, introduces a couple of problems. First, a portion of the laser diode output is reflected from the laser diode-optical fiber connection back toward the laser. This back reflection affects the operation of the laser by interfering with, and thus altering, the frequency and amplitude of the laser output oscillations. Second, the increased power associated with using a laser diode as an optical source introduces a concern for the safe operation of the data transmission system. These concerns include potential exposure of the laser output to the eye, particularly if the optical fiber is detachable from the transmitter, and operation of the system within prescribed power output specifications.
Methods are known to minimize laser diode back reflection caused by the laser diode output. A known manner of minimizing back reflection of laser output oscillations in a laser diode-optical fiber transmission system includes inserting an element intermediate the laser diode and the transmission fiber. Examples of such systems are shown in U.S. Pat. Nos. 4,372,644 to Unger and 4,807,954 to Oyamada, et al. Unger discloses a polarizing element intermediate the laser diode and the optical fiber to convert the linearly polarized wave at the laser output to a circularly polarized wave at the optical fiber input. In effect, the polarizing element acts as an isolator for suppressing back reflection of any light for which the polarization state is preserved upon reflection. Oyamada shows a lens element between the laser diode and the optical fiber to reduce the backward coupling efficiency of back reflected light, thereby substantially preventing reflection of the light beam from the fiber back to the laser. Neither Unger nor Oyamada, however, address power output considerations, as neither device shows means to significantly attenuate the output power of the laser diode. Moreover, neither Unger nor Oyamada suggest that an increased laser diode signal-to-noise ratio can be achieved by increasing the drive current supplied to the laser diode.
It is an object, then, of the present invention to provide a fiber optic data transmission system comprising a laser diode transmitter and an optical fiber, having an increased signal-to-noise ratio achieved by operating the laser diode at a higher drive current to increase its extinction ratio.
It is another object of the present invention to provide a laser diode transmitter for use in a fiber optic data transmission system, the optical power radiating from which is within prescribed safety limits.

Fiber optic transmitter modification for improved extinction ratio

International Business Machines Corporation


A method for using machine learning to solve problems having either a “positive” result (the event occurred) or a “negative” result (the event did not occur), in which the probability of a positive result is very low and the consequences of the positive result are significant. Training data is obtained and a subset of that data is distilled for application to a machine learning system. The training data includes some records corresponding to the positive result, some nearest neighbors from the records corresponding to the negative result, and some other records corresponding to the negative result. The machine learning system uses a co-evolution approach to obtain a rule set for predicting results after a number of cycles. The machine system uses a fitness function derived for use with the type of problem, such as a fitness function based on the sensitivity and positive predictive value of the rules. The rules are validated using the entire set of training data.

1. Field of the Invention
This invention relates to the use of machine learning to predict outcomes and to the validation of such predictions.
2. Description of the Related Art
Machine learning techniques are used to build a model or rule set to predict a result based on the values of a number of features. The machine learning involves use of a data set that typically includes, for each record, a value for each of a set of features, and a result. From this data set, a model or rule set for predicting the result is developed.
These machine learning techniques generally build on statistical underpinnings. Statistical approaches test a proposed model against a set of data. Machine learning techniques search through a space of possible models, to find the best model to fit a given set of data.
Many existing machine learning systems use one type of machine learning strategy to solve a variety of types of problems. At least one system exists that uses a combination of machine learning strategies to derive a prediction method for solving a problem. As described in International Patent application number W097/44741, entitled "System and Method for Combining Multiple Learning Agents to Produce a Prediction Method," published Nov. 27, 1997, and claiming priority from U.S. Ser. No. 60/018,191, filed May 23, 1996, an article entitled "Coevolution Learning: Synergistic Evolution of Learning Agents and Problem Representations, Proceedings of 1996 Multistrategy Learning Conference," by Lawrence Hunter, pp. 85-94, Menlo Park, Calif.: AAAI Press, 1996 and an article entitled "Classification using Cultural Co-evolution and Genetic Programming Genetic Programming: Proc. of the First Annual Conference," by Myriam Z, Abramson and Lawrence Hunter, pp. 249-254, The MIT Press, 1996 multiple learning strategies can be used to improve the ability of any one of those learning strategies to solve the problem of interest. A system incorporating some of these teachings is available as CoEv from the Public Health Service of the National Institutes of Health (NIH). The foregoing patent application and articles are incorporated herein by reference.
In a "co-evolution" system such as described above, an initial set of learning agents or learners is created, possibly using more than one machine learning strategy or method. Examples of machine learning methods include the use of genetic algorithms, neural networks, and decision trees. Each of the learning agents is then trained on a set of training data, which provides values from a set of features, and provides predictions for a rule for solving the problem. The predictions are then evaluated against a fitness function using RELIEF, which may be based on the overall accuracy of the results and/or the time required to obtain those results.
A set of results is obtained and the feature combinations used by the learning agents are extracted. The data is then transformed to reflect these combinations, thereby creating new features that are combinations of the pre-existing features.
In addition, a new generation of learning agents is created. Parameter values from the learning agents are copied and varied for the new generation, using (for example) a genetic algorithm approach.
Then, the process is repeated, with the new learning agents and representations of features, until sufficiently satisfactory results are obtained, or a set number of cycles or a set amount of time has been completed.
This system can provide improved results over systems using a single machine learning method. However, it still has significant limitations when attempting to apply it to real-world problems. For example, a fitness function based on overall accuracy is not suitable for all problems. Moreover, the method and the results are not easily used with many problems.


Questions are received for a conference call. The questions are submitted electronically, such as by email or Instant Messaging (IM). The questions can be submitted before and/or during the conference call. The questions are clustered into one or more similar categories. The clustered questions are sent to participants of a conference. For example, the questions can be sent to a presenter of the conference call as an agenda to follow for a question and answer section of the conference call. Likewise, the questions may also be sent to the conference participants as an agenda of the question and answer section of the conference call. The presenter can discuss the questions with the conference participants based on the categorization of the submitted questions.

Electronic conferencing systems have become pervasive within most enterprises. The types of conferences that are conducted can range from a simple voice conference to a large conference within a corporation. The current solutions for simple voice conferences are typically very efficient.
However, for large conference calls, the logistics for organizing the conference call are not always efficient. For example, a CEO of a large corporation may have a regular meeting where the CEO provides a status to all members of the corporation. In many cases, the members of the large corporation are geographically dispersed at various locations. For these types of conference calls, the conference attendees may submit questions prior to the conference call or during the conference call. The method of submitting the questions can vary. For example, questions may be submitted via email, Instant Messaging, and/or vocally. Keeping track of the questions can be a difficult task because of the volume of questions and because of the variety of sources of the questions.


The present invention is directed to fracturing fluids having temperature-sensitive viscosities. The fracturing fluids may include a mixture of a hydrophobically associative polymer (HAP) and a surfactant in an aqueous medium, wherein the surfactant imparts a critical solution temperature (CST) to the fluid. The fluid is more viscous at temperatures lower than the CST as compared to temperatures above the CST.

Fracturing, or hydraulic fracturing, involves the injection of specialized fluids into geologic formations to create fractures. These fractures, in combination with flow paths drilled by wellbores, allow hydrocarbons, such as oil or natural gas, to flow from the deep recesses of the geologic formations to the ground surface. The injected specialized fluids are called fracturing fluids, which carry proppant into the fractures.
For many years, fracturing fluid technology centered on a wide range of polymers such as guar, hydroxypropyl guar (HPG) and hydroxyethylcellulose (HEC). Cross-linked polymer gels, such as those based on guar crosslinked with borate or polymers crosslinked with metal ions, were also used to attain a sufficient fluid viscosity and thermal stability in high temperature reservoirs. Since high viscosities are needed to carry the required amount of proppant, high concentrations of polymer are used. At higher polymer concentrations, several problems can occur, the most serious being unwanted residual damage to the formation face and proppant pack, plugging off possible permeable pore throats due to unbroken gels. Even with the use of advanced breaker systems, large amounts of residuals can be left behind.
Recently polymer-free viscoelastic surfactants (VES) were used for aqueous drilling and treating fluids. These VES materials are advantageous over the use of polymer gelling agents, since they are low molecular weight surfactants, in that they are less damaging to the formation, leave no filter cake on the formation face, leave very little coating on the proppant, and don't create microgels or "fish-eyes". VES-gelled fluids are an improvement over polymer-gelled fluids from the perspective of being easier to clean up the residual gel materials after the fluid viscosity is broken and the fluid flowed back.
Viscoelastic surfactant molecules, when present at a sufficient concentration, can aggregate into overlapping worm- or rod-like micelles, which confer the necessary viscosity to the fluid to carry the proppant during fracturing. At very high shear rates, e.g., above 170 s−1, the viscosity can decrease, allowing the fluid to be pumped down the wellbore. Viscoelastic surfactant fluids are disclosed, notably, in the patents published under the numbers U.S. Pat. No. 4,615,825, U.S. Pat. No. 4,725,372, U.S. Pat. No. 4,735,731, CA-1298697, U.S. Pat. No. 5,551,516, U.S. Pat. No. 5,964,295, U.S. Pat. No. 5,979,555 and U.S. Pat. No. 6,232,274, which are all fully incorporated by reference. One well-known polymer-free aqueous fracturing fluid comprising a viscoelastic surfactant, which has been commercialized by the company group Schlumberger under the trade designation CLEARFRAC, is a mixture of the quaternary ammonium salt N-erucyl-N,N-bis(2-hydroxyethyl)-N-methyl ammonium chloride with isopropanol in a brine comprised of, for example, 3 weight percent ammonium chloride and 4 weight percent potassium chloride.
On one hand, the leak-off rate of VES fracturing fluids is normally high, so they are mainly used with hydrocarbon bearing formations wherein the permeability of the formation rocks is low. In addition, On the other hand the costs incurred by the use of high-concentration VES systems in aqueous wellbore service fluids, especially fracturing fluids, are pretty high. In particular, many VES fluid systems exhibit long viscosity recovery times after experiencing prolonged high shear. Slow recovery negatively impacts drag reduction and proppant transport capability, which consequently lead to undesirably high treating pressures and risks of near wellbore screen-outs. Many additives are developed to improve the performance but with increased cost.
Polymers and surfactants are often used together in industrial formulations to take advantage of their characteristically different properties. One class of polymers which interact particularly strongly with surfactants is the class of hydrophobically modified water-soluble polymers. See U.S. Pat. No. 4,432,881 to Evani, which is fully incorporated by reference. Since contact between the hydrophobic groups and water is unfavorable, these polymers have a strong tendency to self-associate and/or to associate with surfactants. Progressive addition of surfactants which form spherical micelles typically gives rise to an increase in the viscosity of the solution, followed by a decrease in the viscosity at higher surfactant concentrations. The enhancement in viscosity is typically attributed to the formation of mixed micelles between the polymer alkyl chains and the surfactant molecules, reinforcing polymer intermolecular cross-links. The micelles solubilize alkyl groups belonging to more than one polymer chain, and the system becomes cross-linked.
High concentrations of polymer are typically used to adequately carry an appropriate amount of proppant. At higher polymer concentrations, the fracturing fluid can have a gel-like characteristic, which can result in proppant packing and the plugging of permeable pore throats. These adverse consequences have resulted in the development and use of polymer-free viscoelastic surfactants (VESs), which have been mixed with hydrophobically modified polymers to form systems used for aqueous drilling and fracturing applications. The interaction between hydrophobically modified polymers and surfactant micelles forms a hydrocarbon-responsive fluid that breaks down upon contact with hydrocarbons. The VESs often require expensive additives to overcome VES systems that exhibit long viscosity recovery times, shearing issues, and undesirable and expensive high pressure treatment requirements.
Unfortunately, the use of fluids with hydrophobically-modified polymers in the prior art presents a significant practical limitation. Hydrophobically-modified polymers can have a slow hydration rate, making the onsite preparation of fluids containing them difficult and slow to prepare, especially at the injection well bore.
Accordingly, there is a need for fracturing fluids that are readily hydratable, have viscosity properties that enable efficient and inexpensive pumping and proppant transport down boreholes, and that reduce or avoid damage to subterranean formations harboring reservoir hydrocarbon fluids.

Temperature sensitive viscoelastic well-treatment fluids


A charging member includes a conductive base material and a conductive outermost layer provided on the conductive base material, wherein the conductive outermost layer has a ten-point average surface roughness Rz of 2 μm to 20 μm and contains a resin and particles in which particles having a particle diameter of 5.0 μm or more and a circularity of 0.8 or less are 30% by number or less with respect to the total number of particles having a particle diameter of 5.0 μm or more and particles having a particle diameter of less than 5.0 μm and a circularity of 0.8 or less are from 20% by number to 80% by number with respect to the total number of particles having a particle diameter of less than 5.0 μm.

1. Technical Field
The present invention relates to a charging member, a process cartridge, and an image forming apparatus.
2. Related Art
In an image forming apparatus which uses an electrophotographic method, first, charging is performed by using a charging device on a surface of an image holding member which is configured of a photoconductive photoreceptor made of an inorganic or organic material, a latent image is formed, and then, the latent image is developed by a charged toner, and a visualized toner image is formed. In addition, a target image is formed by transferring the toner image to a recording medium, such as a recording sheet, via an intermediate transfer member or directly, and fixing the transferred image to the recording medium.

Charging member, process cartridge, and image forming apparatus


A system for inerting a casting vessel, such as a traversable ladle or torpedo vessel, used for transporting molten metal, the vessel being positioned below the molten metal outlet opening at a transfer station, and the vessel cavity being flushed with an inert gas both prior to the molten metal inletting and during the inflow of the molten metal in such a manner as to avoid contact between the molten metal surface and the vessel and the atomospheric oxygen. A blowpipe is arranged in the vicinity of the molten metal outlet opening but does not intersect the molten metal stream, is located outside the free space profile of the vessel at least during the approach and return of the vessel, and terminates a distance from the vessel inlet opening and produces at its terminal end an inert gas stream which enters the cavity of the vessel adjacent the molten metal stream at an acute angle.

This invention relates to a system for inerting a casting vessel, such as a traversable ladle or torpedo vessel, used for transporting molten metal, the vessel being used when tapping a blast furnace. With the vessel positioned below the molten metal outlet opening at a transfer station, the vessel cavity is flushed with an inert gas both above the cavity inlet and during inflow of the molten metal into the vessel, in such a manner that contact between the molten metal surface in the vessel and the atmosphere is effectively prevented.
A related system of this type is disclosed in German Patent No. 39 03 444 in which inert gas is forced into the interior of the casting vessel through a flexible feed line in the vicinity of the vessel while positioned below the molten metal outlet opening at a transfer station. A disengageable coupling is attached to the casting vessel, and a stationary pipe is connected to that coupling on the outer surface of the vessel having a through opening in the wall thereof. Such openings are arranged to lie above the maximum molten metal level in the vessel and below the inlet opening of the casting vessel at its upper edge.
The drawback of such arrangement is that all casting vessels used for transporting molten metal in a metallurgical operation must be provided with an inlet opening or openings in the vessel wall thereof, such that special consideration must be taken with a realization that such openings must penetrate both the outer metal jacket and the conventional refractory lining of the casting vessel And, such openings are unusually made after the vessel finishing operation which is time consuming and uneconomical.
And, when a casting vessel is relined due to wear such openings which again need be made involve additional time-consuming treating operations.
Despite the care taken in the provision of such openings it is difficult to assure that the molten metal or slag will not flow into such openings and plug them despite the specified distance between the molten liquid level and the open end of the vessel. The plugging occurs while filling the vessel with molten metal and only leads to expensive maintenance work.
Moreover, the prior art system requires the coupling and uncoupling of the flexible inert gas feed line to or from the stationary pipe on the vessel which demands additional operations and care, normally carried out manually, can involve a complex operation especially when the casting vessel is Positioned below a casting platform since pressurization of the feed line with inert gas is controlled normally on or below the casting platform. Improper coupling and uncoupling and improper inert gas feed control can lead to serious damage to the entire system and to the undesired outflow of inert gas.
The aforementioned drawbacks result in added costs due to increased investment and maintenance, and results in added safety risks.

System for inerting a casting vessel used for transporting molten metal


A method for purification of an amino acid which comprises contacting an amino acid solution containing impurities with an ion exchange resin to selectively adsorb the amino acid onto the resin, eluting and recovering the adsorbed amino acid whereby the resin is contacted with the amino acid solution in countercurrent continuous multiple steps during adsorption and an eluent is contacted with the adsorbed resin in countercurrent continuous multiple steps during elution.

1. Field of the Invention:
The present invention relates to a method for purification of an amino acid using ion exchange resin, whereby the amino acid is contacted with the resin in countercurrent continuous multiple steps to greatly reduce the required amount of resin and the amount of water necessary for washing the resin.
2. Discussion of the Background:
Ion exchange resins have been widely used in purification and collection of highly pure amino acids from crude amino acid solutions industrially prepared by fermentation, synthesis and extraction. Serious problems involved in the use of ion exchange resin are that they require large amounts of resin and use large amounts of water. That is, where an amino acid is purified, it has been heretofore conventional to apply fixed bed operations using ion exchange resin. This technique comprises an adsorption step in which a fermentation broth of an amino acid having a pH adjusted to a specific value is contacted with a salt type, strongly acidic cation exchange resin layer, such as an ammonia type, etc. to adsorb the amino acid onto the resin layer. This step is followed by an elution step in which the amino acid is eluted with an eluent such as ammonia water, and the ion exchange resin is regenerated to a salt type.
When fermentation broth is passed through a conventional resin tower in the adsorption step, washing water is passed through after the fermentation broth in order to permit the fermentation broth to completely pass through the resin layer. In the elution step, washing water is passed after the fermentation broth in order to permit an eluent to completely pass through the resin layer. Furthermore, suspended substances in the fermentation broth are deposited in the resin tower during the adsorption step so that large amounts of washing water flowing in the reverse direction are needed to remove the deposit after completion of adsorption. This is not the only reason that water needs increase. The amount of water discharged during elution is large and facilities for treatment of the waste water become huge.
The amount of washing water increases as the amount of resin used increases. It is thus expected that by reducing the amount of resin used, the amount of washing water can be reduced and hence, facilities required for resin operations can be down-sized. Based on this expectation, various methods for reducing the amount of washing water used have been investigated (Japanese Patent Application Laid-open Nos. 50-127879, 52-11173 and 62-65690) but a considerable amount of washing water is still required.

Method for purification of an amino acid using ion exchange resin


A vehicle user can request emergency or roadside assistance from a response center by activating a button in the vehicle. The global positioning system is used to continuously store the vehicle location. A cellular telephone network is used to contact a response center and transfer a data string via modem containing information to assist the response center in acting on the request. Prior to attempting dialing of the cellular transceiver, a command or set of commands places the cellular transceiver into an unrestricted operating mode to provide the greatest probability of completing a call from the vehicle to the response center and from the response center to the vehicle.

The present invention relates in general to a communication system that provides an automated and simplified interface between a vehicle and an emergency response center using cellular telephone communications, and more specifically to selecting cellular phone operating modes that maximize the ability to successfully complete a call from the vehicle to the response center or from the response center to the vehicle.
The use of transportation vehicles such as automobiles on roads and highways inevitably involves some number of breakdowns or collisions, or situations involving health difficulties of a driver or a passenger in which roadside vehicle service, such as a tow truck, or emergency assistance, such as police, ambulance, or fire, are needed. A means of summoning help is desirable in such situations and the availability of radio communications has been very beneficial in that regard. Cellular telephones are often installed or carried in vehicles by their owners for this reason.
The response time to a request for help should be minimized to meet any potential need for critical services. Accurate information must be provided to the emergency service provider to permit effective and timely response. However, many cellular phone callers to emergency services are unable to provide their location accurately in a timely manner. In addition to position information, a service provider benefits from having information on vehicle identification, cellular phone number of the telephone in the vehicle, the cellular system identification from which a call originated, and speed and heading of a vehicle.
Automatic position locating systems such as a global positioning system (GPS) receiver have been utilized in conjunction with a cellular telephone unit to provide position information over a cellular link. Copending U.S. applications Ser. No. 08/419,349 and Ser. No. 08/419,350, each entitled "Vehicular Emergency Message System", describe a communication system which has high reliability and ease of use based on an automated interface between the vehicle and the response center.
An individual cellular telephone installed in a vehicle may be set-up by the owner in such a way that only some specific cellular communications are permitted while other possible communications are inhibited. These restricted operating modes can arise from a desire to avoid using certain cellular service providers (i.e., carriers) or geographic areas or from a desire to restrict the numbers which can be called from the individual phone as determined by the owner. However, these restricted operating modes or service levels of the cellular telephone can interfere with the ability of an emergency message system to contact a response center or with the ability of the response center to place a return call to the cellular telephone.

Vehicular emergency message system with call restriction defeating