A continuous speech recognition apparatus includes a hypothesis storage section for storing hypotheses, a hypothesis expansion discrimination section for determining whether or not a hypothesis may be expanded to a succeeding arc, a hypothesis expansion section for expanding a hypothesis and storing a result of the expansion into the hypothesis storage section, a tree structure dictionary storage section for storing a tree structure dictionary and a context preceding to the tree structure dictionary therein, a succeeding word speech part information storage section for storing information of whether or not speech parts are included in all of succeeding words present behind each of arcs in the tree structure dictionary, a speech part connection information storage section for storing connection information between the speech parts, a language model section for providing a language model score to a hypothesis, and an acoustic model section for providing an acoustic model score to a hypothesis.

1. Field of the Invention
The present invention relates to a continuous speech recognition apparatus and method, and more particularly to a continuous speech recognition apparatus and method which achieves augmentation in speed and accuracy of recognition.
2. Description of the Related Art
As an example of a conventional continuous speech recognition apparatus, reference is had to a paper by S. Ortmanns, xe2x80x9cLANGUAGE-MODEL LOOK-AHEAD FOR LARGE VOCABULARY SPEECH RECOGNITIONxe2x80x9d, ICSLP, 1996.
The conventional continuous speech recognition apparatus is shown in FIG. 6. Referring to FIG. 6, the conventional continuous speech recognition apparatus shown includes a hypothesis storage section 1, a hypothesis expansion section 3, a tree structure dictionary storage section 4, a language model section 7, and an acoustic model section 8.
In operation, the hypothesis storage section 1 stores hypotheses therein. The tree structure dictionary storage section 4 stores words, which make an object of recognition, as a tree structure dictionary (refer to FIG. 2). The acoustic model section 8 calculates an acoustic model score for each frame. The language model section 7 calculates a language model score.
The hypothesis expansion section 3 acquires, for each frame, a structure of arcs from the tree structure dictionary storage section 4 taking an acoustic model from the acoustic model section 8 and a language model score from the language model section 7 into consideration and expands a hypothesis present on an arc to a succeeding arc. Referring to FIG. 2, a tree structure dictionary is structured such that a word is reached by tracing arcs branching in a tree structure from a root to a leaf (terminal arc).
Speech which makes an object of recognition is divided into short-time frames of a predetermined period, and such expansion as described above (that is, expansion of a hypothesis on an arc of a tree structure dictionary to a succeeding arc) is repeated from the speech beginning frame to the speech terminating frame. Then, a word through which a hypothesis which exhibits the highest score has passed in the past (a terminal of the tree structure dictionary) is finally determined as a recognition result.
Here, a hypothesis has position information of an arc on a tree structure dictionary, a history until the position is reached, and a score.
In a continuous speech recognition system wherein a plurality of words are represented as one tree structure dictionary (refer to FIG. 2), what is a word with regard to which a hypothesis is being expanded at present cannot be specified except at the terminal arc.
Therefore, although an acoustic model score is calculated for each frame, a language model score can originally be determined only when a hypothesis reaches a terminal arc of a tree structure dictionary.
Therefore, in order to add a language model score as early as possible, a method employing look-ahead of a unigram language model score and look-ahead of a bigram language model score is disclosed in the document mentioned hereinabove.
According to the look-ahead of a unigram language model score, the highest one of unigram language model scores of words settled at terminal arcs in a tree structure dictionary is provided to a predecessor arc, and the unigram language model provided to the arc is temporarily added as a language model score of the hypothesis present on the arc, and then, when the hypothesis reaches the terminal arc of the tree structure dictionary and the word is settled, the unigram language model score which has been used till then is abandoned and then the settled bigram language model score is added.
On the other hand, according to the look-ahead of a bigram language model score, when a context is determined and a new tree structure dictionary is produced, bigram language model scores regarding all words of the context are calculated, and that one of the language model scores which has the highest score is provided to a predecessor arc, and then the bigram language score provided to the arc is added as a language model score of the hypothesis present on a certain arc.
The conventional speech recognition system has the following problems.
The first problem resides in that, when look-ahead of a bigram language model score is performed, a great memory capacity and a large amount of calculation are required.
The reason is that, where look-ahead of a bigram language model score is performed, when a context is produced and a tree structure dictionary is produced newly, it is required to repeat processing of producing not part of a tree structure dictionary but an entire tree structure dictionary, calculating all bigram language model scores with respect to the context and provide language model scores of all terminal arcs in the tree structure dictionary, with which words are settled, to a predecessor arc to propagate the language model scores to all predecessor arcs.
The second problem resides in that, when look-ahead of a unigram language model score is performed, wasteful calculation is performed.
The reason is that, when look-ahead of a unigram language model score is performed, some of arcs of a tree structure dictionary may expand only to a word whose connection to the context is not permitted linguistically and the hypothesis is expanded also to such arc, in which wasteful calculation is involved.
The third problem is such as follows. If strict look-ahead of a language model score of a bigram or more is not performed using a frame synchronous beam search (for the frame synchronous beam search, for example, Hermann Ney, xe2x80x9cData Driven Search Organization for Continuous Speech Recognitionxe2x80x9d, IEEE TRANSACTIONS ON SIGNAL PROCESSING, February, 1992 is referred to), that is, if connection possibility according to linguistic restrictions between a context and a word in a tree structure dictionary is not looked ahead, then the hypothesis is expanded also to an arc which is developed to a word whose connection to a context is not permitted linguistically as described above in connection with the second problem.
Then, if the score of the hypothesis is much higher than the others, then all hypotheses on an arc which is developed to a word whose connection to the context is permitted linguistically are excluded from the beam and thus eliminated.
As a result, in the succeeding frames, the word cannot be connected to a next word at all, and recognition processing for speech uttered later is disabled. In other words, recognition processing cannot be performed any more and a recognition result cannot be outputted.
It is an object of the present invention to provide a continuous speech recognition apparatus and method by which the recognition speed and the recognition accuracy in continuous speech recognition can be augmented.
In order to attain the object described above, according to an aspect of the present invention, there is provided a continuous speech recognition apparatus, comprising a hypothesis storage section for storing hypotheses therein, hypothesis expansion discrimination means for determining whether or not a hypothesis may be expanded to a succeeding arc, a tree structure dictionary storage section for storing a tree structure dictionary and a context preceding to the tree structure dictionary therein, a succeeding word speech part information storage section for storing information of whether or not speech parts are included in all of succeeding words present behind each of arcs in the tree structure dictionary, a speech part connection information storage section for storing connection information between the speech parts, means for providing a language model score to a hypothesis, means for providing an acoustic model score to a hypothesis, and hypothesis expansion means operable in response to an expansion instruction received from the hypothesis expansion discrimination means for acquiring a structure of an arc from the tree structure dictionary storage section and expanding a hypothesis present on the arc to a succeeding arc taking the acoustic model score and the language model score into consideration and then storing a result of the expansion into the hypothesis storage section.
According to another aspect of the present invention, there is provided a continuous speech recognition method for a continuous speech recognition apparatus which includes a hypothesis storage section for storing hypotheses therein, a tree structure dictionary storage section for storing a tree structure dictionary and a context preceding to the tree structure dictionary therein, a succeeding word speech part information storage section for storing information of whether or not speech parts are included in all of succeeding words present behind each of arcs in the tree structure dictionary, and a speech part connection information storage section for storing connection information between the speech parts, comprising the step of repeating a process for all of hypotheses present at a certain frame time, the process including the steps of acquiring a context of a tree structure dictionary to which a hypothesis belongs from the tree structure dictionary storage section, acquiring speech part connection information of the speech parts of the context from the speech part connection information storage section, acquiring arcs in the tree structure dictionary to which the hypothesis belongs from the hypothesis storage section, and repeating, for all succeeding arcs immediately succeeding the arcs, a process including the steps of acquiring, where an arc selected at present is represented as first arc and a succeeding arc immediately succeeding the first arc is represented as second arc, succeeding work speech part information of the second arc from the succeeding word speech part information storage section, discriminating from the acquired speech part connection information and the acquired succeeding word speech part information whether or not the hypothesis may be expanded from the first arc to the second arc and determining that the hypothesis must not be expanded to the second arc if a connectable speech part included in the speech part connection information is not detected behind the second arc, but determining otherwise that the hypothesis may be expanded to the second arc, expanding the hypothesis to the second arc. and discriminating whether or not the loop has been completed for all of the hypotheses and ending, when the loop has been completed for all of the hypotheses, the expanding processing of the hypotheses of the frame in a frame synchronous beam search.
With the continuous speech recognition apparatus and method, a hypothesis is prevented from being expanded to an arc to a word which cannot connect linguistically to a context. Consequently, the number of unnecessary hypotheses is minimized and the speed of continuous speech recognition is augmented as much. Further, occurrence of a situation that the score of a hypothesis to a word which cannot connect linguistically to a context is higher than those of the other hypotheses is prevented. Consequently, the recognition accuracy in continuous speech recognition is augmented.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference symbols.

Continuous speech recognition apparatus and method


Techniques for caller verification in Rich Communication Services (RCS) for text messaging are discussed herein. A communication client can be the communication client designated to receive incoming communications for the user equipment. The user equipment may use the communication client to send, to a network device, a Session Initiation Protocol (SIP) instance to set communication client. The SIP instance may include a primary designator and a Universally Unique Identifier (UUID) associated with the client. The network device may store the information for the user equipment including the UUID and capability set. A second user equipment may poll the network device for the communications capabilities of the first user equipment before establishing a connection.

Modern telecommunication systems include heterogeneous mixtures of second, third, fourth, and fifth generation (2G, 3G, 4G, 5G) cellular wireless access technologies, which may be cross-compatible and may operate collectively to provide communication services. Global Systems for Mobile (GSM) is an example of 2G telecommunications technologies; Universal Mobile Telecommunications System (UMTS) is an example of 3G telecommunications technologies; Long Term Evolution (LTE), including LTE Advanced, and Evolved High-Speed Packet Access (HSPA+) are examples of 4G telecommunications technologies; and New Radio (NR) is an example of 5G telecommunication technologies.
To take advantage of the multigenerational mix of wireless communication technologies, user devices configured for telecommunications are capable of communicating, not only via various types of networks but also via various types of communication clients developed for the different networks. For instance, these user devices may be configured to use Rich Communication Services (RCS) as the communication protocol for messaging, over the previous Short Message Service (SMS) messages. However, while RCS provides a richer text-message system by allowing messaging via application programming interface (API)'s called Messaging as a Platform (MaaP), these API's do not require Subscriber Identity Module (SIM) based authentication to occur. Hence opportunities for spoofing text messages will be greater.

Caller verification in rich communication services (RCS)


In a large scale FIFO circuit comprising a shift register circuit, the shift register circuit is reduced in its occupation area size to reduce the entire size of the FIFO circuit. A necessary number N of addresses is divided by positive integers A, B, . . . , M (where Axc3x97Bxc3x97. . . , xc3x97Mxe2x89xa7N) to form a plurality of small scale shift register circuits in each of an A address generation circuit (1), B address generation circuit (2), . . . , and, an M address generation circuit (3). An external input CLK (i.e., clock) signal is supplied to only one of the small scale shift register circuits, i.e., only the A address generation circuit. Of the remaining small scale shift register circuits, one has its address output signal supplied to its successors as a clock input signal by cascading the remaining small scale register circuits in connection, so that a plurality of the A addresses, B addresses, . . . , and, the M addresses are generated, which are combined with each other, whereby addressing or address setting is performed.

1. Field of the Invention
The present invention relates to a large scale FIFO (i.e., large scale integration First In First Out) circuit in which a shift register circuit constructed of a plurality of flip-flop circuits performs address generation. More particularly, the present invention relates to a large scale FIFO circuit which is capable of reducing its entire size by reducing the occupation area size of the shift register circuit.
Further, the present invention relates to a large scale FIFO circuit capable of temporary storing data in a memory when the data is low in processing speed. The large scale FIFO circuit is also capable of outputting the thus processed data from the memory at high speed in order of completion of such processing of the data.
2. Description of the Related Art
As shown in FIG. 5, the large scale FIFO circuit of this type is used extensively in each of: a shift resister circuit 51-W which assigns memory locations of a memory 50 to input data Din being stored therein; and, a shift resister circuit 51-R which identifies the memory locations of the memory 50 from which output data Dout is sequentially retrieved.
Heretofore, as shown in FIG. 6, in this type of the large scale FIFO circuit, for example, with respect to addresses of 16 words, 16 pieces of the flip flop (hereinafter referred to as the F/F) circuits 100 to 115 are used to form a shift register circuit. These F/F circuits 100 to 115 are connected in series with each other, wherein an output signal of the last F/F circuit 115 is inputted to the first F/F circuit 100 to provide a loop arrangement in the F/F circuits 100 to 115. Further, the same clock (hereinafter referred to as the CLK) signal is applied to the CLK terminals of these F/F circuits 100 to 115. Each of addresses 0 to 15 corresponds to an output signal of each of the corresponding F/F circuits 100 to 115, and, therefore supplies such output signal therefrom.
Consequently, in a condition in which shift data stays in the address 0 at a time of occurrence of a first CLK signal, when a second CLK signal is inputted to tall the CLK terminals of the F/F circuits 100 to 115, the shift data is shifted to the address 1. When a third CLK signal is inputted to all the CLK terminals of the F/F circuits 100 to 115, the shift data further is shifted to the address 2. In this way, the shift data is successively shifted from one address to another address which is successive to such one address when the successive CLK signal is inputted to the CLK terminals of the F/F circuits 100 to 115.
In the conventional large scale FIFO circuit just described above, the number of stages of the F/F circuits which form the shift register circuit is large, so that the shift register circuit is large in occupation area size, which increases the entire size of the FIFO circuit, and, therefore presents a problem.
The reason why the entire size of the FIFO circuit increases is that the number of stages of the F/F circuits forming the shift register circuit is directly depending on the number of words, i.e., size of a memory to which the F/F circuits are directed. For example, in the case of small 32 words, a necessary number of stages of the F/F circuits is only 32. However, in the case of, for example, large 1000 words, a necessary number of stages of the F/F circuits becomes a very large number such as 1024. Due to this, the entire size of the FIFO circuit increases.
It is accordingly an object of the present invention to solve the above problem by providing a large scale FIFO circuit, the entire size of which FIFO circuit is reduced by reducing a shift register circuit in its occupation area size.
According to a first aspect of the present invention, there is provided a large scale FIFO circuit in which address generation is performed by a shift register circuit constructed of a plurality of flip flop circuits, the improvement wherein:
the shift register circuit is divided into a plurality of small scale shift register circuits each constructed of a plurality of the flip flop circuits; and
the address is defined by combination of outputs of the flip flop circuits which form each of the small scale shift register circuits.
According to a second aspect of the present invention, there is provided a large scale FIFO circuit in which address generation is performed by the shift register circuit constructed of a plurality of the flip flop circuits:
a plurality of small scale shift register circuits each constructed of a plurality of the flip flop circuits are formed;
an input clock signal is supplied to a first one of the small scale shift register circuits;
of the remaining ones of the small scale shift register circuits, one has its address output signal supplied to its successors as a clock input signal by cascading the remaining small scale register circuits in connection;
the number of addresses in the address generation is divided by a positive integer, which integer forms a first factor of the number of the addresses, to produce a plurality of second factors of the number of the addresses;
the number of the flip flop circuits in each of the small scale shift register circuits is equal to the number of each of the second factors of the number of the addresses;
an input clock signal is supplied to a first one of the small scale shift register circuits; and
of the remaining ones of the small scale shift register circuits, one has its address output signal supplied to its successor as a clock input signal by cascading the remaining small scale register circuits in connection.
Due to the above construction, it is possible that the large scale FIFO circuit is constructed of a plurality of thus divided small scale shift register circuits. This reduces the number of the flip flop circuits forming the shift register circuit. Since the shift register circuit is reduced in size, it is possible to reduce the entire size of the FIFO circuit.
A preferable mode for practicing the present invention has the following construction: namely
In a large scale FIFO circuit in which: address generation is performed by a shift register circuit constructed of a plurality of flip flop circuits; and, addresses in the address generation identify memory locations of a memory in each of a read and a write side of the memory, the memory having an address space for a plurality of words the number of which is N, the improvement wherein:
the N is divided into its factors A and B (i.e., N=A xc3x97B; where each of N, A and B is a positive integer);
with respect to each of the factors A and B, each of a plurality of small scale register circuits is formed;
an input clock signal is supplied to one of the small scale shift register circuits, which one corresponds to the factor A to supply an output signal to the other of the small scale shift register circuits as a clock signal therefor, the other corresponding to the factor B.
In this case, in each of the read and the write side, it is possible for the shift register circuit to reduce the number of N pieces of the conventional flip flop circuits up to (A+B) pieces.
Further, when each of the small scale shift register circuits is of the same circuit scale, it is possible for the large scale FIFO circuit to be a minimum size in construction.
The reason why it is possible to reduce the shift register circuits in their occupation area size and to reduce the entire size of the FIFO circuit is that: addressing or address setting is performed by combination of a plurality of addresses, which addresses are generated by sequentially cascading the small scale shift register circuits, wherein: the number of necessary addresses is divided to form a plurality of small scale shift register circuits; an external input clock signal is supplied to only one of the small scale shift register circuits; and, of the remaining ones of the small scale shift register circuits, one has its output signal supplied to its successor as a clock input signal by cascading these small scale shift register circuits.


A method of generating a message by providing on a communication channel an indication of a message identifier, the combination of communication channel and identifier uniquely indicating a message for any specific destination.

Telecommunication services are widely available around the world. A person can simply pick up a phone and dial a destination number at any location through the public switching telephone network (PSTN), wireless networks (Cell Phone) and the Internet.
Similarly messaging via networks of various other protocols is well known and these protocols act to transfer messages from place to place.
The telecommunication networks process calls to and from different subscriber telephones based on a unique telephone number or other ID, and the Internet routes calls based on the source and destination network identifier or IP address.
Another popular communication method is short message service. A person can use an SMS capable terminal or service to send an SMS/MMS to another persons' SMS/MMS capable terminal.
One of the services provided by many telecommunication networks is caller identification. It is designed to allow the caller to be identified prior to the call being answered. However, caller identification is currently limited to identification the landline or wireless telephone number and the name of the subscriber of a service.
The present invention relates to a method for disseminating of signals and delivering a message or response to a destination in an interactive environment. It may utilise standard telecommunication and network communication media with suitable standard telecommunication or network communication equipment. More particularly, it relates to methods for transmitting a message through the use of the communication facilities of a process, instead of the traditional approach of using the message facilities of a connection for the purpose of transmitting a message.
Therefore, in view of the foregoing, it would be advantageous to provide a method, system, and program for providing a fast, reliable method of communication that ensures a message reaches the destination as requested, automatically.
The present invention provides a solution to this and other problems which offers advantages over the prior art or which will at least provide the public with a useful choice.

Message dissemination system for nominating a trigger event to a specific destination based on communication channel and message identifiers


There is proposed a technique for determining an estimate of interference power, in the receiver of a communication system utilizing adaptive antenna techniques. The technique uses information transmitted in the antenna signals and in the beam signals to determine the estimate of the interference power.

In wide-band code division multiple access (W-CDMA) systems, precise power control is one of the basic requirements for high system capacity. Transmit powers in the down-link should be kept as low as possible in order to minimise interference, but high enough to ensure the required quality of service. Furthermore, in the downlink, it is desirable to provide a marginal amount of additional power to mobile stations at the cell edge, as they suffer from increased other-cell interference.
Even though a relatively slow power control algorithm is able to compensate for large-scale attenuation, distance attenuation and shadow fading, a fast power control algorithm is needed for multi-path fading for slowly moving mobiles.
In the forward link, i.e. the down-link, of a wide-band code division multiple access (WCDMA) system, the inner-loop power control adjusts the base-station transmit power in order to keep the received down-link signal-to-interference ratio (SIR) at a given target level (at the mobile station). The SIR target is defined according to the quality requirements. For reliable SIR estimation, narrowband estimation (after de-spreading) has to be employed. This is important especially in the down-link direction of the W-CDMA system because of the usage of orthogonal channelization codes. Tight delay requirements of the power control demand that the SIR estimation has to be obtained on a slot-by-slot basis.
The SIR estimation is divided into: a) signal power estimation; and b) interference power estimation.
In the forward link of a wide-band code division multiple access (WCDMA) system, a primary common pilot channel (P-CPICH) is broadcast over the entire cell or a sector. The P-CPICH is broadcast also in the case of a multi-beam arrangement (multiple beams per sector) and in the user specific beamforming. Therefore there always exists one such channel per sector regardless of the applied transmission scheme.
In the case of single antenna transmission, the interference power estimation is currently performed based on the primary common pilot channel. However, when utilising adaptive antenna techniques the dedicated channels are usually transmitted through a narrow beam, which means that the P-CPICH and down-link physical channels (DL-DPCH) experience different channel characteristics in transmission to the mobile station antenna. Due to that the fading of DL-DPCH can be almost uncorrelated compared to that of P-CPICH. The correlation depends on the angular spread of the radio channel (seen from the base transceiver station).
In current known systems, the down-link dedicated physical control channel (DL-DPCCH) is used for power interference estimation for the DL-DPCH (beam signal) in adaptive antenna systems because of the fact that the P-CPICH (antenna signal) does not usually experience the same channel characteristics on transmission to a mobile station antenna.
It is an aim of the present invention to provide an improved technique for estimating interference power in the receiver of an adaptive antenna system.

This patent is subject to a terminal disclaimer.

Interference power estimation for adaptive antenna system


Video processing system having a blocking system which prevents viewing or recording of programs which exceed ratings, spending, and/or view time limits set by a supervisor who has entered a password accepted by the control system, an override system for entering instructions to temporarily override ratings, spending, and/or view time limits, and/or to permit specific programs to be viewed, and a conflict resolution system for resolving conflicts between or among multiple instructions. Related apparatus and processor are also disclosed.

This invention relates to systems for blocking viewing or recording of television programs which exceed a ratings, spending, or viewing time limit, or other viewing limit set by a supervisor.
Video signal processing systems such as television tuners contained in television sets, video cassette recorders, or cable boxes which are suitable for coupling to a display device such as a picture tube and which contain circuitry and software designed to prevent viewing of programs containing ratings information below a level set by a supervisor or exceeding spending limits in pay-per-view systems, are very well known. The programmed processor allows a supervisor with a password, usually a parent, to set a limit over or outside of which supervised persons, such as young children, cannot view broadcasts.
A device or system that provides such control permits a supervisor to prevent certain programs and/or scenes from being viewed and heard based on the content of the program/scenes, the subscription cost, or total viewing time for a period such as a day. For example, a parent might specify that programs and/or scenes including violent subject matter should be excluded. A supervisor can also specify a rating limit, such as PG-13, and programs and scenes exceeding that limit (e.g., R and X rated programs) could not be viewed or heard. The supervisor can also limit the use of pay-per-view or can set a pay-per-view spending limit The supervisor can also enter a daily maximum view time. The ratings, spending and view time can be chosen in a profile, which may also include the name of the user, or an identification such as "children." In some situations, one or more profiles can be defined, for example a second profile for "parents," and a third for "babysitter." Each profile may have a different ratings limit, pay-per-view spending limit, and view time limit, and can only be accessed by the person specified in the profile, i.e., the children can not apply the parent profile since it is protected by a password.
By decoding program content information included in an auxiliary information component of a program signal (e.g., Extended Data Services (XDS) data in an NTSC television signal in the United States or PSIP data in an ATSC television signal), a television receiver containing a "stripper" (or decoder) can "slice" or extract information (e.g., from the vertical blanking interval (VBI) of an NTSC television signal in the United States) to determine the content and rating of television programs and scenes and can compare the content and rating to the limits set by the supervisor. Other data such as spending data or time limits may be received in other ways, for example using the system clock to calculate elapsed active view time.
When the ratings information or other information for a program exceeds a limit set by the supervisor, the processor is designed to blank the screen and mute the audio portion of the broadcast. For television receivers which also have multi-image display capability, the receiver would provide supervisor control for both main and auxiliary pictures when both are displayed. In addition, the receiver may display a message indicating the reason for the interrupted reception and the expected duration of the interruption (e.g., SCENE EXCEEDS CONTENT LIMIT).
In situations where the supervisor wishes to temporarily change the ratings limit, time limit, or spending limit, or to permit viewing of a particular television broadcast, the supervisor must reset the ratings limit, and then remember to restore the original limit. Due to the inconvenience of having to reset the original limit, we have conceived of a system for temporarily overriding the normal limits, as disclosed in a copending patent application entitled RATINGS CONTROL SYSTEM WITH TEMPORARY OVERRIDE CAPABILITY, Ser. No. 09/475,448 filed on even date herewith, hereafter referred to as "Override Invention." Our aforementioned Override Invention provides a video signal processing system such as a television receiver, cable box, or VCR tuner for producing an output signal suitable for coupling to a display device to produce a displayed image, which blocks viewing of programs which are received with embedded ratings information, spending information, and/or view time which is outside a range selected by a supervisor, and permits the supervisor to enter a temporarily revised range or permit specific programs to be viewed; the system then automatically restores the normal limits at the end of the temporary override.
While the Override Invention provides several ways for a supervisor to override the normal viewing limitations, for example by a modified ratings limit for a defined temporary period; an override for a single broadcast program; an override for a specific time period on a regular basis; an override to allow spending to exceed the normal limit for a particular day; and an override to allow the supervised person to view television for a different time limit, it is herein recognized that choosing more than one override option may present conflicts for the system. The present invention addresses that problem.

Ratings control system with temporary override capability and conflict resolution feature


A diacetal of a polyhydric alcohol is provided having at least one carbamoyl substituent bonded to an oxy group of the alcohol. The compound is useful as a nucleating agent in polymer resins and as a gelling agent.

This invention relates to carbamoyl derivatives of diacetals of polyhydric alcohols and aromatic aldehydes, which are useful as nucleating agents for polymer resins and as gelling and thickening agents for organic liquids.
The use of nucleating agents to reduce the haze in articles manufactured from crystalline polyolefin resins is well known in the art. Representative acetals of sorbitol and xylitol, which have been employed as clarifying agents, include the following U.S. patents: Hamada, et al., U.S. Pat. No. 4,016,118, dibenzylidene sorbitols; Kawai, et al., U.S. Pat. No. 4,314,039, di(alkylbenzylidene) sorbitols; Mahaffey, Jr., U.S. Pat. No. 4,371,645, di-acetals of sorbitol having at least one chlorine or bromine substituent; Kobayashi, et al., U.S. Pat. No. 4,954,291, distribution of diacetals of sorbitol and xylitol made from a mixture of dimethyl or trimethyl substituted benzaldehyde and unsubstituted benzaldehyde; and Rekers, U.S. Pat. No. 5,049,605, bis(3,4-dialkylbenzylidene) sorbitols including substituents forming a carbocyclic ring.
Methods for manufacturing the acetals may be found in Murai, et al. U.S. Pat. No. 3,721,682 and New Japan Chemical EP 0 497 976.
Although the exact mechanism is not well understood, it is generally believed that the nucleating agent must solubilize and reform into a very fine network within the polyolefin resin. This crystalline network provides nucleation sites, which reduces the size of the spherulites formed in the resin as it cools. Small spherulites do not scatter visible light as effectively as large spherulites, so the nucleated polyolefin resin has improved clarity.
The acetals may be incorporated into a thermoplastic resin as a nucleating agent by blending the acetals and powdered resin together, and then extruding the mixture. One concern that arises during processing is that the acetals can sublimate and redeposit causing "plate out". Consequently, it is often desirable to employ acetals with a relatively low volatility.
As the melting point of the nucleating agent increases, however, it generally becomes necessary to extrude the resin/acetal mixture at higher temperatures. One method of using lower processing temperatures is disclosed in Mannion, U.S. Pat. No. 5,198,484; the acetals are milled to ultrafine particle size, and dissolved in the resin at below their melt temperature. Nevertheless, milling the acetals requires additional processing steps and capital investments in equipment. Further, the solubility of the acetal in the resin may become a factor at operating temperatures below the nucleating agent's melt temperature. Additional considerations in regard to the performance of the acetals as nucleating agents in polymer resins include the cost and availability of the aromatic aldehydes, organoleptics and efficacy.
An alternative clarifying agent for polyolefin resin is disclosed in New Japan Chemical JP 6-256590 (1994). A polyurea containing polymethylene segments of 2 to 12 carbons was found to be an effective crystal clarifying agent at concentrations of 0.01% to 0.05%.

Carbamoyl substituted acetals and compositions containing the same


An improved method for building a plug in a horizontal wellbore using a fluid pill pumped into the wellbore at the end of a fracturing treatment. The fluid pill includes a high concentration of an ultra lightweight proppant, such as a neutrally buoyant proppant or an ultra lightweight proppant mixture. The fluid pill is pumped down the wellbore until it almost reaches fractures within a zone of interest. The pumping is then ceased or reduced, allowing the fractures to partially close. The ultra lightweight proppant remains suspended within the fluid pill while stationary. The pumping is then resumed at a very slow rate or as a short pump burst, thus causing the proppant in the fluid pill to bridge off until a bridge plug is formed.

1. Field of the Invention
The present invention, in general, relates to an improved method for building a proppant plug in a horizontal wellbore at a zone of interest and, more specifically, to utilizing a fluid pill containing a high concentration of ultra lightweight proppant in order to form a proppant plug in a horizontal wellbore.
2. Description of the Related Art
New hydrocarbon reserves are increasingly being discovered in lower quality reservoirs, particularly in North America. These lower quality reservoirs require some form of "stimulation" to increase the production of hydrocarbons from wells in these fields. Fracture stimulating a well to increase the production of hydrocarbons is common practice in the oil and gas industry. Many of these reservoirs require multiple fractures to reach economic production levels and provide effective drainage. After the casing in a zone of interest has been perforated and stimulated, it must be hydraulically isolated before any new zone of interest can be exploited. A zone is often isolated by the insertion and setting of a mechanical plug, hereinafter referred to as a bridge plug, below the zone of interest.
The purpose of the bridge plug is simply to hydraulically isolate that portion of the well from a lower portion (or the rest) of the well. The isolation of the lower zone ensures high pressure fracturing fluid pumped into the well is directed to the zone of interest. The high pressure fracturing fluid is used to fracture the formation at the open perforations in the casing. The high pressure of the fracturing fluid initiates and then propagates a fracture through the formation.
In a vertical well, a bridge plug is typically run into the wellbore using a wireline, but the use of wireline to run a bridge plug in horizontal wellbores is limited to formations that are not overly sensitive to water or excess over-displacement of fluids into the fracture. This is because in order to get the bridge plug into the horizontal wellbore, the bridge plug is connected to wireline and pumped into a horizontal wellbore. The pumping of the bridge plug into the wellbore displaces the wellbore treatment fluids into the formation, which may have an adverse affect on the hydrocarbon production of the well depending on the rock formation as well as its time sensitivity to the fracture fluid. Alternatively, coiled tubing may be used to push and set the bridge plug into horizontal wellbore to isolate a zone of interest. The use of coiled tubing to run a bridge plug is time consuming and expensive because the coiled tubing needs to be removed from the wellbore between each fracturing process in order to rig up the next bridge plug that will be run for the subsequent treatment.
In an effort to reduce time and costs, another method has been developed to isolate a zone within a horizontal wellbore. This method is to build a sand plug in the wellbore at the perforation zone such that the plug hydraulically isolates the zone from the lower portion of the wellbore. To build a sand plug, the end of the fracturing fluid includes a pill of fluid containing an elevated amount of sand or proppant in comparison to the amount of sand or proppant present in the fracturing fluid. The fluid pill is pumped into the well under the fracturing pump rate. The formation at the zone of interest should have already been fractured as the fluid pill approaches the zone of interest because the fluid pill is located at the tail end of the fracturing fluid.
The pumping, and thus displacement of the fracturing fluid, is stopped as the fluid pill reaches the perforation tunnels at the zone of interest. The fluid pill with a high concentration of sand remains stationary within the wellbore with the hope that the sand or proppant remains suspended in the fluid pill. The displacement of the fracturing fluid is stopped for a period of time to allow the fractures within the formation to partially close. Once partially closed, the displacement of the fluid pill is resumed, normally at a low rate in comparison to the pump rate during the fracturing process.
The fluid pill is pumped at a low rate moving the fluid pill into the perforation tunnels and into the fractures. Typically, the pump rate is set low enough to prevent the fractures from reopening. The pumping of the fluid in the wellbore causes the fluid of the fluid pill to enter the fractures, but the high concentration of sand or proppant suspended within the fluid pill screens out against the fractures because the fractures are partially closed. Subsequently, the suspended sand in the fluid pill begins to bridge off against the fractures. As the process continues, the sand continues to pack off against the perforation tunnels and eventually the sand packs off against itself creating a sand plug in the wellbore. The slow rate of pumping is continued until the pressure within the wellbore rises indicating that a proper sand plug has been built within the wellbore.
Building a sand plug within a horizontal wellbore is a difficult process because any gravitational settling of sand or proppant in the wellbore will leave a fluid channel at the top of the hole and subsequent pumping will simply allow sand free displacement fluid to pass down the 'channel" and into the fracture without allowing a sand plug to form. The fluid pill needs to remain stationary long enough to allow the fractures in the formation to at least partially close and so the fracturing fluid must suspend the sand or proppant for at least this period of time. If the sand does not remain suspended and settle out, it is likely that a proper sand plug will not be achieved. This is because, as the sand settles, clear fluid or fluid without suspended sand becomes located at the top of the horizontal wellbore. As pumping is resumed, the fluid of the fluid pill will simply stream over the sand bed rather than carrying the sand into the perforation tunnel because of the gap at the top of the horizontal bore.
Failing to build a sand/proppant plug will inevitably require a remedial operation involving a pump down wireline plug or a coiled tubing run.
Thus, it is critical that the sand remains suspended in the fluid pill while the fluid pill is stationary and/or being propagated adjacent the perforations. However, the sand and/or methods utilized in prior art isolation techniques have difficulty maintaining sand suspension, which leads to costly and time consuming workovers and cleaning jobs.
In light of the foregoing, it would be desirable to use an ultra lightweight proppant or neutrally buoyant proppant to build a sand plug within a wellbore. It would also be beneficial to provide a method of building a sand or proppant plug in a wellbore wherein a proppant may be used that remains suspended in a various fracturing fluids. It would also be desirable to provide a method of varying the density of proppant used in a fluid pill to build a sand plug within a wellbore as this allow a greater range of fracturing fluids that may be used in the fracturing process. It would also be desirable to provide a method of using a fluid pill containing a proppant that promotes screening out at the perforations such as using a proppant having a larger diameter than the proppant used in the fracturing process.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the issues set forth above.

Method of isolating open perforations in horizontal wellbores using an ultra lightweight proppant


A diaphragm pump comprising a pumping chamber (10) is operated by a continuous flow of pressure gas to a driving chamber (12) separated from the pumping chamber by a flexible diaphragm (8 or 52). Deflection of the diaphragm by the gas pressure drives liquid out of the pumping chamber. The driving chamber has a normally closed outlet valve (30 or 54) connected to the diaphragm through a flexible or lost-motion connection (34, 36 or 56) so that the valve is opened after a certain deflection of the diaphragm. The driving chamber pressure is thereby released and allows the diaphragm to return, drawing further liquid into the pumping chamber. The return movement of the diaphragm also allows the valve to reclose and the cycle is repeated while the supply of pressure gas to the driving chamber is maintained.

This invention relates to diaphragm pumps operated by gas pressure, particularly but not necessarily exclusively for medical services.
U.S. Pat. No. 4,319,570 discloses a fluid-pressure operated diaphragm pump to be used as an aspirator or tracheal suction pump. It has a pumping chamber in part defined by a flexible diaphragm, the flexure of which creates a suction in a drainage line. In a further chamber separated from the pumping chamber by a secondary sealing diaphragm is a valve mechanism comprising inlet and outlet valve members which are opened and closed in opposition to each other as the diaphragm reciprocates, the opening of the outlet valve being triggered by the flexure of the diaphragm to a position of maximum pumping chamber volume and the opening of the inlet valve being triggered by a return spring that is operative when the diaphragm flexes to a position of minimum pumping chamber volume. The valve mechanisms required in this pump are relatively complex. They therefore carry an increased risk of malfunction in addition to being relatively expensive to produce. Cost is particularly important if the valve is to be disposable, as is often required for surgical apparatus.
Another pressure-fluid operated diaphragm pump is disclosed in U.S. Pat. No. 4,662,829 in which pumping and driving chambers are separated by a flexible diaphragm and the driving chamber is connected continuously to a pressure air source. The flexible diaphragm is stretched over an exhaust port of the driving chamber during the contraction of the pumping chamber, by virtue of the pressure differential between the pumping chamber and the exhaust line, until the continuing flexure of the diaphragm under the driving fluid pressure forces the port open. At that stage, the pressure in the driving chamber is released via the exhaust port, the diaphragm collapses onto that port, and the cycle begins again.
Although this pump has a relatively simple mechanism as compared with the previously described example, it has inherent disadvantages. In particular, in order for the diaphragm to maintain a seal with the driving chamber exhaust, a portion of its area must be held stationary during the pumping stroke despite the fact that the deflection of the diaphragm that is lost thereby reduces the pumping rate. It is possible to compensate for this to a limited extent by employing more flexible diaphragm materials but the risk of overstressing and rupture of the diaphragm is then increased, and such measures cannot make up for the limitation of the pumping rate for any given size of pump due to the fact that part of the diaphragm is not participating in the pumping stroke.


A passenger conveyor assembly including a roller assembly having an axle member, a bearing member mounted to the axle member, and a roller member rotatably mounted to the bearing member. A seal assembly is mounted to the roller assembly. The seal assembly includes a rotating member mounted for rotation with the roller member and a stationary member fixedly mounted relative to axel member. The rotating member and stationary member cooperate to substantially prevent foreign objects from accumulating at one of the bearing member and the axle member.

Exemplary embodiments pertain to the art of bearing assemblies and, more particularly, to a seal assembly for a bearing assembly.
Bearings are used in a wide range of application to reduce frictional effects that may occur between two components moving one relative to another. For example, escalators employ a number of bearings to reduce friction that may be generated between rollers and rails as escalator steps travel between floors. Escalators have been used for years to transport people from one level to another in numerous applications. Conventionally, escalators include a plurality of steps that are moved along rails that extend from a first end positioned at a first level or floor and a second end positioned at a second level or floor. The steps include rollers that travel along the rails. The steps are configured to nest one against the other at each of the first and second ends to provide a smooth transition to the first and second floors. Typically, escalators are employed in office buildings, shopping centers, museums, as well as numerous other indoor installations. Escalators are also employed in outdoor locations such as at train stations, metro/subway stations, stadiums and the like. Outdoor installations expose the rollers and associated roller assemblies to foreign objects such as water, dust, other debris and the like. As such, the rollers are provided with seals that are configures to damage to bearings, shafts and the like from foreign objects.


A method of treating waste product containing flexible polyurethane resin includes adding a decomposing agent to the waste product to start a decomposition reaction; and terminating the decomposition reaction at a stage in which a diamine concentration derived from an isocyanate raw material of the flexible polyurethane resin is 2 wt % or lower to obtain a pasty intermediate product.

1. Field of the Invention
The present invention relates to a method of treating waste product containing flexible polyurethane resin, more specifically to a method of treating waste product processed by a volume reduction process using a chemical decomposition method and a reheating process for reproduction.
2. Description of the Related Art
Flexible polyurethane resin has been widely used as cushion material for vehicle seats, furniture, mattresses etc. However, recycling thereof is difficult because the resin is thermosetting and has a 3-dimensional network structure which cannot be remolded. Thus, used flexible polyurethane resin has been disposed of as landfill or incinerated after shredding without being recycled.
In waste processing of a used automobile, for example, after useful parts and the like are collected by a dismantler, scrapped cars are shredded, and, after removing metals such as iron for recycling, the remaining shredder residues of a vehicle seat are disposed of as landfill. However, the flexible polyurethane resin contained in the shredder residues, especially flexible polyurethane foam is bulky and contains bubbles that have a low density in the volume. Thus, there is a demand for reduction in the volume sort of the shredder residue by some method because the transportation cost is high even if the residue is disposed of as landfill, or if heat and resources are recovered by other methods.
Such a situation is not limited to the vehicle seat residues. Waste processing of cushion material which uses flexible polyurethane resins for sofas, chairs, mattresses etc, are in a similar situation, and thus there is a demand for a volume reduction method which is effective in reducing the transportation costs.
In addition to such a volume reduction, there is a demand for recycling of polyurethane resin in a waste product in order to effectively utilize resources in the future. On the other hand, studies have long been conducted on methods for chemically decomposing and liquefying polyurethane resins. For example, those methods include a method of decomposing a rigid polyurethane foam by an amine compound such as alkanol amine and then separating and recovering a decomposed product to reproduce it as a polyurethane foam, a method of decomposing a polyurethane foam with polyol and aminoethanol as decomposing agents and reproducing it as an adhesive agent, a ketone/aldehyde decomposition method, an isocyanate decomposition method, a thermal decomposition method, a hydrolysis method, a heating-up method in the latter process etc.
However, in the case where applying the aforementioned decomposition methods to the decomposition of the flexible polyurethane resin, the finally obtained decomposed product is separated into two phases, i.e., a solid body in a lower layer and a liquid polyol in an upper layer, irrespective of the kinds of decomposition methods used. The decomposed product thus separated into two phases has a reduced volume compared with a flexible polyurethane resin before decomposition, however, handling thereof is difficult, and carrying-in, carrying-out and transportation are complicated. Consequently, it is impossible to provide a sufficient reduction in transportation costs through a reduction in volume.

Image file arrangement for use with an improved image quality assurance system


In an electron-emitting device having a pair of electroconductors arranged on a substrate at an interval, a top of one electroconductor is higher than that of the other electroconductor and a groove extending from the interval region toward a position under a region where the one electroconductor is come into contact with the substrate is formed on the substrate. Deterioration of the electron-emitting device due to collision of charged particles is suppressed by the asymmetrical electron-emitting region, electron-emitting efficiency is improved, and a long life is realized.

1. Field of the Invention
The invention relates to a surface conduction electron-emitting device, an electron source using such an electron-emitting device, an image display apparatus, and their manufacturing method.
2. Related Background Art
Hitherto, there has been known an electron-emitting device in which a pair of electroconductors is arranged on a substrate surface at an interval, the substrate surface between the pair of electroconductors has a groove portion, and by applying a predetermined voltage across the electroconductors, an electron is emitted from the electroconductor portion (refer to Japanese Patent Application Laid-Open No. 2000-231872).
FIGS. 9A and 9B show a construction of the electron-emitting device disclosed in Japanese Patent Application Laid-Open No. 2000-231872. In the diagrams, reference numeral 101 denotes a substrate; 102 and 103 device electrodes; 104 an electroconductive thin film; 105 a carbon film; 106 a groove portion; and 107 an electron-emitting region. FIG. 9A is a schematic plan view of such a device. FIG. 9B is a schematic cross sectional view taken along the line 9B-9B′ in FIG. 9A.
As a manufacturing method of the electron-emitting device of FIGS. 9A and 9B, the device electrodes 102 and 103 are formed on the substrate 101, the continuous electroconductive thin film 104 is formed so as to connect the device electrodes 102 and 103, thereafter, a gap is formed by applying a forming voltage across the device electrodes 102 and 103 (forming step), and the carbon films 105 containing carbon and/or a carbon compound as a main component are further deposited on the electroconductive thin films 104 of the both electrode sides (activating step). At this time, in the substrate 101 under the gap formed in the electroconductive thin film 104, the groove portion 106 in which a material of the substrate is altered by the heat of the activation is formed.

Electron-emitting device, electron source, image display apparatus, and their manufacturing method


The present invention relates to a manufacturing method of a printing circuit board. The manufacturing method mainly includes: forming one or more cylindrical micro-radiators by cutting a high conductive and electrical insulating substrate according to predetermined size; manufacturing one or more mounting holes in copper clad plates and prepregs; embedding the cylindrical micro-radiators into the mounting holes. The present invention combines the micro-radiator with high thermal conductivity and traditional stiffness printing circuit board. The printing circuit board with micro-radiators has the advantages of high thermal conductivity and stable heat transfer, and also has the advantages of routing flexibility and reliable electrical connections.

Printing circuit boards (PCBs) are one of important elements in electronics industry. PCBs are used as mechanical support elements for the electronic components, and realize electrical connection among the electronic components. In addition, graphics and numbers of the components can be printed on the PCBs, it is convenient for furnishing, checking or maintaining the components. The PCBs are used in almost every electronic device, such as electronic watch, calculator, computer, communication electronics device, military weapon systems.
Traditional PCBs are plated through hole structure, insulation material among layers is FR4 material, the thermal conductivity of the insulation material is 0.4 W/mk. In recent years, the thermal conductivity of the insulation material is 1.3-2.2 W/mk. When plenty of integrated circuits (especially high power LED) are installed on the printing circuit board, the thermal conductivity of the printing circuit board come up to tens or hundreds of W/mk. Obviously, it is far beyond the thermal conductivity of the insulation material of the prior art.
Therefore, there are some shortcomings in the prior art.

Manufacturing method of printing circuit board with micro-radiators


A variety of test structures may be fabricated with aluminum runners and overlying dielectrics. The dielectrics are removed and bumps are observed upon the aluminum runners. Unevenness in the bump distribution is a predictor of long term reliability problems. A test structure may be utilized to design integrated mass production fabrication processes.

Typical integrated circuits contain an array of transistors which are covered by layers of dielectric through which conductive lines run. Illustratively, these conductive lines may be made from aluminum with conductive underlayers and conductive overlayers of other materials. Typical fabrication processes involve the blanket deposition of aluminum layers, i.e. by sputtering. (As just mentioned, other conductive layers may be deposited prior to the aluminum layer and subsequent to the aluminum layer.) The aluminum layer, together with any underlayers and overlayers, is patterned by lithographic methods known to those of skill in the art to create conductive lines.
Each integrated circuit manufacturer has one or more processes or recipes for the formation of metal runners, such as aluminum, with its associated underlayers and overlayers. Each recipe may include sputtering times, metal composition, temperatures, thicknesses, etc.
Those concerned with the development of integrated circuits have, however, noticed that apparently satisfactorily manufactured integrated circuits may often fail in subsequent use. A variety of phenomena are associated with these failures. One well documented failure mechanism is termed "stress migration voiding". Stress migration voiding affects the long term reliability of the integrated circuits. Another factor affecting long term reliability is extrusion of the aluminum runner material. Since the aluminum runner undergoes more compression at the bottom of the runner then at the top, a stress gradient exists and the runner may be extruded near its bottom. Another problem which affects long term reliability is decohesion of the aluminum. Aluminum does not always adhere well to underlying dielectrics such as silicon dioxide. Sometimes underlayers such as titanium or titanium nitride do not assist in adhesion of the aluminum because the titanium oxidizes, thereby destroying its adhesive properties. (Some integrated circuits utilize aluminum fuses which do not have underlayers--decohesion is a particularly worrisome problem for these circuits.)
Long term reliability issues are particularly worrisome to integrated circuit manufacturing process designers because, of course, these reliability failures do not occur until the already-manufactured devices are in field use. Thus, a manufacturing engineer may be confronted with the unhappy prospect of being forced to modify his production process after hundreds or thousands of integrated circuits have been manufactured because those circuits in field use have exhibited long term reliability problems.
Thus, there exists a need to predict where a metal conductor, such as an aluminum runner will fail after leaving the factory; to predict when the runner might fail; and then, to determine how, if at all, the manufacturing processes might be modified to prevent such a failure in the future.
Those concerned with fabrication of other types of perhaps macroscopic metallized structures are confronted with similar problems.


A method is provided for security key renewal performed in a key management device of a communication system. The communication system includes two or more communication devices communicating data packets by using a first security key for transmission and reception. The method includes transmitting, to the two or more communication devices, a second security key for transmission and reception of the data packets; transmitting, to the two or more communication devices, an activation message for activating use of the second security key for reception of the data packets; transmitting, to the two or more communication devices, an activation message for activating use of the second security key for transmission of the data packets; transmitting, to the two or more communication devices; a deactivation message for deactivating use of the first security key for transmission of the data packets; and transmitting, to the two or more communication devices, a deactivation message for deactivating use of the first security key for reception of the data packets.

Real-time communication systems rely on a well-functioning communication channel between two communicating devices that are part of the communication system. The communication channel is typically imposed with strict requirements in different regards, for example in view of determinism, latency, jitter and loss of data packets. Another aspect is security of the communication and an applied security layer may slightly delay the communication, but should not interrupt the communication channel or cause loss of data packets. Keys used for securing the communication channel, e.g. for authentication and encryption of data packets, typically need to be renewed on a regular basis in order to keep the security on a required level. In many communication systems the same key is used for a group of devices and a dedicated key server distributes the keys and enables the use of the keys in the devices.
A difficulty during a key renewal process is that all devices of the communication system using the same key should renew their keys simultaneously in order not to risk data packets to be invalidated in the receiving device due to use of expired keys. This problem is particularly pronounced in communication systems involving a large number of devices and even further so when the distance between the devices is large. For example, in communication between substations of an electric power transmission system the communicating devices may be distributed widely apart and may use different key servers or key groups. In such communication system it may not be sufficient to renew the key simultaneously, since there may be data packets travelling in the system which have not yet reached their destination, and could be invalidated upon arrival by being encrypted with an old key and received with a renewed key.

Methods and devices for security key renewal in a communication system


An in situ process is provided for isolating semiconductor devices according to a LOCOS process. The invention contemplates performing field oxide growth, nitride layer removal, sacrificial oxide growth and removal, and gate oxide growth all within a single chamber without removing the wafers from the chamber during processing. The invention is believed to result in increased yields and process throughput by reducing the exposure of the wafers to outer-chamber contaminants, thermal stress, and transportation damage, as well as reducing inter-chamber transportation time. The invention also contemplates an in situ processing chamber adapted for performing field oxide growth, nitride layer removal, sacrificial oxide growth and removal, and gate oxide growth as part of a LOCOS isolation process. The in situ processing chamber is adapted for thermal oxidation and etching processes to implement the LOCOS isolation structure. A conventional oxidation furnace may be adapted to provide the in situ processing chamber by adapting the oxidation furnace to accept etchant gasses. Other conventional chambers or a specialized chamber may also be adapted according to the present invention for the in situ LOCOS process.

1. Field of the Invention
This invention relates to semiconductor fabrication and more particularly to an improved process of isolating active regions within a semiconductor substrate. The improved isolation process involves growing a field oxide, removing a nitride layer, growing and subsequently removing a Kooi oxide, and forming a gate oxide all within a single chamber without opening the chamber to an atmospheric ambient.
2. Description of the Relevant Art
The fabrication of an integrated circuit involves placing numerous devices in a single semiconductor substrate. Select devices are interconnected by a conductor which extends over a dielectric which separates or "isolates" those devices. Implementing an electrical path across a monolithic integrated circuit thereby involves selectively connecting isolated devices. When fabricating integrated circuits it must therefore be possible to isolate devices built into the substrate from one another. From this perspective, isolation technology is one of the critical aspects of fabricating a functional integrated circuit.
Metal oxide semiconductor (MOS) transistors (i.e., devices) are typically formed in isolated active device regions of a frontside surface of a semiconductor substrate. These active device regions are separated by field regions. Electrically insulating layers of silicon dioxide (i.e., oxide) are usually formed over the field regions (i.e., field oxide), and the MOS transistors are electrically coupled by conductive trace elements called interconnects. An interconnect which overlies field oxide between device active areas may inappropriately function as a gate electrode of a parasitic MOS transistor formed between diffused regions of two adjacent MOS devices. Certain measures must be taken to ensure that any possible operating voltage present between the interconnect and the underlying silicon substrate is not sufficient to invert the substrate surface beneath the interconnect. If the substrate beneath field oxide is allowed to invert, a conductive channel will form between the diffused regions of the parasitic MOS transistor. Current flow through parasitic MOS transistors will either cause more power to be dissipated than expected or, in the extreme, cause the circuit to malfunction.
To avoid parasitic conditions, it becomes necessary to raise the turn-on threshold of any parasitic MOS transistors formed in the field regions. One way to raise the turn-on threshold of parasitic MOS transistors is to increase the thickness of the field oxide. Alternatively, or in addition to increasing field oxide thickness, field region doping levels can be increased.
A popular isolation technology used for an MOS integrated circuit involves the process of locally oxidizing silicon. Local oxidation of silicon, or LOCOS, involves oxidizing field regions between devices. The oxide grown in field regions are termed field oxide, wherein field oxide is grown during the initial stages of integrated circuit fabrication, typically before source and drain implants are placed in device areas or active areas. By growing a thick field oxide in isolation (or field) regions pre-implanted with a channel-stop dopant, LOCOS processing serves to prevent the establishment of parasitic channels in the field regions.
While LOCOS has remained a popular isolation technology, it involves many process steps that are conventionally performed in separate processing chambers. The semiconductor wafers are first placed in a thermal oxidation furnace where a pad oxide is grown. The wafers are then removed from the thermal oxidation furnace and transported to a chemical vapor deposition (CVD) chamber where a silicon nitride (Si.sub.x N.sub.y) layer is deposited over the pad oxide. A layer of photoresist is then deposited over the nitride layer. Deposition of photoresist may also involve a separate chamber. The photoresist is then patterned to define active regions and field regions. Patterning of the photoresist is accomplished by exposing selected areas of the photoresist to ultraviolet light. The exposed areas polymerize and become resistant to etching. The wafers are then transferred to a dry etch chamber where the non-polymerized areas are removed. The wafers may then be transferred to a wet etch chamber for removal of the pad oxide over the field regions. The wafers may then be transferred to an implantation chamber where a channel-stop implant is performed. Next the wafers may be transferred back to an etching chamber for stripping of the remaining photoresist. Then the wafers are moved to a thermal wet or dry oxidation chamber where the field oxide is grown. After the field oxide is grown, the wafers are transported to an etch chamber to remove the nitride layer.
During growth of the field oxide, a thin layer of silicon nitride may have formed at the pad oxide/silicon interface near the active region borders, as a result of the reaction between the oxidizing agent and the silicon nitride. The formation of nitride at the edge of the field oxide at the oxide/silicon juncture is called the "Kooi effect". The unwanted nitride or "Kooi ribbon" causes localized thinning of any subsequently grown gate oxide. Thus, to remove the Kooi nitride, the wafers may be moved to an oxidation chamber to grow the pad oxide further in the active regions to consume the Kooi ribbon. Then, the wafers may be moved to a wet etch chamber where the grown oxide is removed. Thus, the grown oxide is termed a "sacrificial oxide". The wafers may then be moved to a dry oxidation chamber to grow the gate oxide. A defect-free, high quality gate oxide without contamination is essential for proper device operation. Finally, the semiconductor devices may be created by depositing and patterning a polysilicon gate over the gate oxide and then doping the source and drain regions.
The LOCOS process described above is a complex process involving many different processing steps. Wafers frequently must be transported between processing chambers. This frequent moving of the wafers inflicts several problems into the process. Repeated moving of the wafers may impose a risk of damaging the wafers. Also, repeated thermal cycling when wafers are moved from warm or thermal processes may result in stress damage to device structures. Furthermore, each time the wafers are removed from a processing chamber, they may be exposed to contaminants that may result in lowering yield. Finally, transportation of wafers between chambers is time consuming and lowers process throughput and efficiency. These effects increase the overall cost of fabrication.
A need therefore exists in producing a process which can advantageously perform LOCOS isolation with a reduction in the aforedescribed detrimental effects of the conventional LOCOS process. Thus, it is desirable to have a process that may impose less risk of damaging the wafers. It is further desirable to have a process that may lessen thermal stress when wafers are removed from processing chambers. Also, it is desirable to lessen the exposure to contaminants outside processing chambers. Moreover, it is desirable to increase the throughput and efficiency of the LOCOS process, thereby lowering overall production cost.

Performing a semiconductor fabrication sequence within a common chamber and without opening the chamber beginning with forming a field dielectric and concluding with a gate dielectric


A pipette member to be attachable to a container capable of accommodating a tissue and a liquid, is used for isolating cells from the tissue by stirring, and includes: a cylinder member which includes a first opening that is to be accommodated in the container, and a second opening that is to be connected to a cell isolation apparatus, and in which a passage for communicating the first opening with the second opening is defined; and a filter member which is disposed inside the cylinder member, and which separates the passage into a first part that includes the first opening, and a second part that includes the second opening.

The present invention relates to a cell isolation instrument which can be used in the case where a pathological analysis is performed.
After a pathological specimen is prepared, a pathological analysis on a tissue slice is performed by a cytotechnologist or a pathologist. When cells are to be isolated from a tissue, the mincing process with using a blade is required. In order to obtain cell suspension containing isolated cells, moreover, a suspension which is obtained after the mincing process must be filtered through a filter. In order to obtain a cell suspension which is to be used in a pathological analysis, as described above, two steps of operation are required.
A skilled technique is required for preparing a specimen or performing a diagnosis by a cytotechnologist or a pathologist, and there is a possibility that a difference may be produced in the diagnosis result depending on the difference in technique. In the period from extraction of a tissue to diagnosis, procedures such as tissue fixation, section preparation, and staining are necessary, and a cytotechnologist or the like is restrained for a predetermined time period. Therefore, procedures which are to be performed before diagnosis are requested to be automatized.
Japanese Patent No. 4156847 discloses a device for mincing a tissue required for culturing cells. The device includes a cylinder member in which a metal mesh is disposed in each of upper and lower openings. A tissue piece is placed on the metal mesh, and a centrifugal separation process is performed on the cylinder member, whereby the tissue is minced.
According to the technique disclosed in Japanese Patent No. 4156847, the mincing process can be automatically performed, but procedures such as section preparation and staining cannot be automatized. Moreover, it is not considered that a cell suspension containing isolated cells is automatically recovered.

Pipette member and cell isolation instrument


A hand-held power tool may include a housing, a power unit disposed within the housing and configured to operate at least in part in response to actuation of a trigger, a working assembly powered responsive to operation of the power unit, and an activation lever having an integrated lockout member. The activation lever may selectively engage a first fuel enrichment mode associated with startup of the power unit in a first range of ambient temperatures and a second fuel enrichment mode associated with startup of the power unit in a second range of ambient temperatures based on a position of the activation lever. Selective engagement of the first fuel enrichment mode or the second fuel enrichment mode may be enabled responsive to actuation of at least the lockout member and positioning of the activation lever.

Chainsaws are commonly used in both commercial and private settings to cut timber or perform other rigorous cutting operations. Because chainsaws are typically employed in outdoor environments, and the work they are employed to perform often inherently generates debris, chainsaws are typically relatively robust hand held machines. They can be powered by gasoline engines or electric motors (e.g., via batteries or wired connections) to turn a chain around a bar at relatively high speeds. The chain includes cutting teeth that engage lumber or another medium in order to cut the medium as the teeth are passed over a surface of the medium at high speed.
Given that the chainsaw is expected to operate outdoors, it can be further expected that the chainsaw is likely to operate in different ambient temperatures. Since many chainsaws that are powered by gasoline engines employ some form of carburetor that may employ a fuel enrichment system, it can be appreciated that starting may be difficult if the weather is very cold. Moreover, it may further be appreciated that manipulation of the fuel enrichment system might be thought of as a way to improve the ability to start the chainsaw.


The hedgehog pathway in cerebellar cancer cells was modulated with siRNA specifically targeted to the shh and gli-I genes. Silencing of the two genes in a medullablastoma cell line transfected with the siRNAs caused significant reduction of mRNA specific for the targeted shh and gli-I genes and a loss of protein expression. The disclosed methods and compositions may be useful for treatment of a range of primitive neuroectodermal tumors (PNET) by shutting down or modulating the expression of gene products associated with the hedgehog pathway.

Pediatric brain tumors are the third most frequent malignancy of children, and brain tumors are the leading cause of death in children with cancer. Medulloblastoma is the most common pediatric tumor of the cerebellum. These tumors can seed along the neuraxis and metastasize to extraneural tissue. During brain development, embryonic neuroepithelial cells migrate outwards and laterally to form the external granular layer of the cerebellum. Primitive neuroectodermal tumors (PNET), like medulloblastomas and basal cell carcinomas (BCC) of the skin, have been associated with two inherited cancer syndromes: Gorlin's and Turcot's. Gorlin's Syndrome, also called nevoid basal cell carcinoma syndrome (NBCCS), is an autosomal-dominant disease characterized by a range of tumor types such as BCC, medulloblastoma, ovarian fibroma, meningioma, fibrosarcoma, rhabdomyosarcoma and cardiac fibroma. Three percent of patients with Gorlin's develop medulloblastoma and Turcot patients are 92-fold more likely to develop medulloblastoma than the general population.
There is accumulating evidence that medulloblastomas result from the molecular dysregulation of the hedgehog (Hh) pathway, in particular sonic hedgehog (SHh), smoothen (Smo), patched (Ptch) and the transcription factor family, Gli1-3. The hh family of genes and their control in mammalian embryonic development is certainly pivotal. SHh plays a number of significant roles in embryonic development including the development of the cerebellum. SHh is produced by Purkinje cells and by granule neuron progenitor cells and is a mitogenic factor for granule neurons as well as a differentiation factor for Bergmann glial cells. In fact, cerebellum hyperproliferation appears to be the result of increased levels of SHh and its prolonged expression. Indeed, SHh has been shown to be associated with medulloblastomas from studies involving transgenic mice that over express SHh and in a transgenic human tissue model.
It is also known that mutations in ptch are responsible for Gorlin's Syndrome. In these individuals, one copy of the ptch gene is mutated, resulting in many of the heterozygous cases of medulloblastoma. Between 12 and 40% of non-inherited BCC arise from inactivation of both alleles of ptch. Ptch mutations, along with several other members of the Hh signaling pathway, also have been directly implicated in the development of medulloblastomas.
Cubis interruptus (Ci) is the terminal component of the Hh pathway, mediating transcriptional activation of hh target genes in response to Hh. Binding sites for Ci have been identified upstream to the promoters of both wg and ptch. There is a high degree of sequence homology between ci and the vertebrate Gli family of transcription factors. In vertebrates there are three homologs of the ci gene: gli1, gli2 and gli3, each having its own distinct pattern of expression. The Gli proteins are large transcription factors that bind DNA in a sequence specific manner via the last three fingers of their five zinc-finger domain. Gli1 is the most potent activator. Gli2 & 3 are thought to have dual functions both as a modified full-length activator and as a truncated processed repressor. Gli1 is constitutively activated in BCC, NBCCS and medulloblastoma.
Since its discovery in plants, post-transcriptional gene silencing has become an important tool in molecular biology. It was shown early on that gene silencing was mediated through a diffusable trans-acting product and later that this trans-acting factor was double-stranded RNA (dsRNA). Both antisense and sense RNA were able to shut down expression of a target gene. Gene silencing studies have shown that dsRNA are more effective at suppressing target genes than anti-sense or sense-strands alone. Only a few molecules of dsRNA are required to attain complete gene silencing. This dsRNA effect has been termed RNA interference (RNAi). RNAi can also be induced by transfecting cells with plasmids that express siRNAs. Furthermore, plasmids containing a sequence encoding a hairpin-forming, 45-50mer double-stranded RNA molecule termed small hairpin RNA (shRNA) under the control of an RNA Polymerase III (Pol 111) promoter when transfected into mammalian cells, have been shown to be more stably expressed, more efficient at reducing the levels of both exogenous and endogenous gene products and provide longer term reduction in target gene than siRNAs alone.
Many researchers are now using RNAi as a tool to ascertain the function of genes because it allows one to create 'loss-of-function' phenotypes quickly and easily. RNAi may also hold promise as a gene-specific therapeutic for the treatment of infectious diseases and cancer.


In one aspect, a method for controlling an internal combustion engine using valve lift switchover is provided. Within the scope of this method, a switchover intake manifold model for the switchover-relevant pressure range for valve lift switchover is applied in addition to the use of a basic intake manifold model. This ensures a valve lift switchover with approximately constant torque of the internal combustion engine.

The principle of valve lift switchover in internal combustion engines is known in the prior art. Thus, for example, systems such as Porsche's Vario Cam Plus have already been in series production for some years (see also "Handbuch Verbrennungsmotor" ("Combustion engine manual"), editor: van Basshuysen/Schäfer, published by Vierweg Verlag, 1st edition, April 2002). A continuing problem with this technology continues to be the valve lift switchover process as such. Switching from a small to a large valve lift in particular creates difficulties in respect of the torque neutrality of the internal combustion engine. Absence of torque neutrality of the internal combustion engine expresses itself in a noticeable bucking of the motor vehicle during the switchover from one valve lift to the other. The reason for the lack of torque neutrality lies in scarcely avoidable inaccuracies in the absorption coefficient or volumetric efficiency model (intake manifold model) of the internal combustion engine.
Said models, which run in the engine management system and are supplied therein with the corresponding operating data of the internal combustion engine, calculate the air mass supplied to the combustion process as a function of the operating point. From this, the fuel quantity that is to be injected is calculated with adherence to a specific air/fuel ratio and taking into account the predefined lambda value. Said fuel quantity in turn determines the expected torque of the respective combustion cycle of the internal combustion engine.
A separate model is stored in the engine management system for each valve lift configuration. The model data is stored in characteristic maps which are formed from what are referred to as sampling points. The quality criterion for the switchover is that the actual engine torque in both configurations—i.e. directly before and after the valve lift switchover—is the same as far as possible. However, even small errors in the model calculation lead to differences in torque and consequently to inaccuracies in the valve lift switchover.
A further problem at this juncture is that the combustion-related behavior of the internal combustion engine usually changes as a result of the valve lift switchover. This is mainly to be expected with channel injectors due to the changed flow cross-section at the valve. A further problem arises if, in the course of the valve lift switchover, a change in combustion behavior takes place, for example when a spark-ignition combustion process transitions to a controlled self-ignition.
In principle the models running in the engine management system can be executed with any desired degree of precision. However, the problem here is that the complexity of the models increases rapidly if all the parameters influencing a quantity to be mapped are to be recorded with a particular precision. Even modern engine management systems quickly reach their limits at this point. In this case the memory storage capacity and computing capacity of the engine management system are rapidly exhausted, with the result that ultimately compromises and sacrifices have to be made with regard to precision.

Method for controlling an internal combustion engine using valve lift switchover


A process for reducing the fluorosurfactant content of a stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion by passing dispersion through a first fixed bed of anion exchange resin to reduce fluorosurfactant content. The first fixed bed has a working zone which moves though the column as the ion exchange resin is saturated. The process includes monitoring a property of the dispersion as the dispersion exits the fixed bed to determine break though of the working zone indicating saturation of the fixed bed. The property being monitored is selected from the group consisting of pH and conductivity.

Fluorosurfactants are typically used as a polymerization aid in the dispersion polymerization of fluoropolymers, the fluorosurfactants functioning as a non-telogenic dispersing agent. For example, an early description of this use of fluorosurfactants is found in U.S. Pat. No. 2,559,752 (Berry). Because of environmental concerns and because fluorosurfactants are expensive, processes have been developed for their recovery from waste water and from aqueous fluoropolymer dispersions.
One method for removal of fluorosurfactants from fluoropolymer dispersions is disclosed in U.S. Pat. No. 4,369,266 (Kuhls et al.) and includes the addition of a stabilizing surfactant followed by concentration by ultrafiltration. This patent teaches that a high proportion of the fluorosurfactant can be removed via the aqueous permeate. It is also known to remove fluorosurfactant by adsorption onto an ion exchange resin as taught in U.S. Pat. No. 3,882,153 (Seki et al) and U.S. Pat. No. 4,282,162 (Kuhls). Kuhls teaches recovery of fluorinated emulsifiers dissolved in the aqueous phase after coagulation of the polymer from the dispersion or in aqueous polymer dispersions to be concentrated. US 2003/0125421 A1 (Bladel et al.) also teaches removal of fluorine-containing emulsifiers from fluoropolymer dispersion by contacting with an anion exchanger.
Known processes using anion exchange resins for the removal of fluorosurfactant from fluoropolymer dispersions employ either strongly basic anion exchange resins or weakly basic anion exchange resins. Although weakly basic resins are useful because they can be regenerated more easily, strongly basis resins are preferred when it is desired to reduce fluorosurfactant to very low levels and for high utilization of the resin. Strongly basic ion exchange resins also have the advantage of less sensitivity to the pH of the media.
For practical commercial manufacture of fluoropolymer dispersion with low fluorosurfactant content, it is known to pass fluoropolymer dispersion through a fixed bed, such as a column of the anion exchange resin. However there is need to produce a uniform dispersion product, i.e., dispersion with a standard low level of reduced surfactant. Fluorosurfactant concentration analysis is routinely performed offline and takes around eight hours to complete the determination. Such a time lapse is not a practical way of determining whether acceptable product is being produced. Unacceptable product having a high fluorosurfactant content may result when a fixed bed is saturated such that the ion exchange sites are no longer adequately absorbing sufficient fluorosurfactant and thereby producing a dispersion with high, unacceptable fluorosurfactant content.
In a fixed bed such as a column, there is a working zone (mass transfer zone) that moves progressively through the column in the direction of flow of the dispersion such that the fluorosurfactant is absorbed onto the ion exchange resin in this working zone. Specifically, fluoropolymer dispersion enters the working zone having an initial fluorosurfactant content and exits the zone with reduced fluorosurfactant content. The fluoropolymer dispersion with reduced fluorosurfactant content passes through the remainder of the unsaturated column and exits the column. The working zone moves progressively through the column until the column is fully saturated. The point at which the column is fully saturated such that working zone has moved entirely though the column and there is no longer adequate absorption by the ion exchange resin is called breakthrough.
What is desired is a process for reducing the fluorosurfactant content of a stabilized fluoropolymer dispersion to detect working zone breakthrough at the end of a column, i.e., column saturation.

Monitoring column breakthrough in a process for removing fluorosurfactant from aqueous fluoropolymer dispersions


When data are thermo-magnetically recorded to a perpendicular magnetized film of a recording medium, it is possible to prevent unnecessary magnetic domains from being formed and unerasable magnetic domains from being produced. The medium 11 is rotated by a motor 12. When being passed through a recording field generated by a magnet 14, the medium 11 is irradiated with a recording beam generated by an optical head 13, so that data can be recorded to a perpendicular magnetized film of the medium 11 as bubble magnetic domains. Further, when the medium 11 passes through a correcting magnetic field generated by a magnet 15 disposed away from the position at which data are recorded, unnecessary and/or unerasable domains can be eliminated.

The present invention relates to a method and apparatus for thermo-magnetically recording information data by applying thermal energy of convergent rays (e.g. a laser beam) to a magnetic layer within a magnetic field and/or reproducing the recorded information data on the basis of magneto-optical effect (referred to as magneto-optical recording/reproducing, thereinafter).
Recently, magneto-optical recording technique adopting a perpendicular magnetized film as a recording medium has been widely researched as one of optical rewritable recording methods and has been already put into practical use. In this method, information data are recorded thermo-magnetically. In more detail, an energy beam such as a constant or pulse-modulated laser beam is focused onto a memory layer within a modulated or static magnetic field to heat the memory area, so that switched magnetic domains can be formed in the memory layer according to information data, in dependence upon the magnetic interaction between the memory layer and the external field, to record information data.
In the prior-art recording technique, however, there exists a problem in that switched magnetic domain are erroneously formed or recorded magnetic domains are distorted in shape due to non-uniformity of the recording medium or focusing error, with the result that recording noise is inevitably generated and therefore the reproduced signal quality is deteriorated. Further, in the case of direct overwriting which needs no erasing operation separate from the recording operation, even though former domains are supposedly erased simultaneously with the recording of new domains over the former domains, in practice, vestiges of some of the former domains still remain as they have not been perfectly erased during the recording of the new domains.

Magneto-optical method and apparatus for recording/reproducing data


Disclosed herein is a compression apparatus useful in treating pain, inflammation, or other conditions of a joint and joint area through use of compression and optionally temperature control. The compression apparatus is configured for physical and functional flexibility in that the apparatus is flexible and can be worn over or under clothing. The compression apparatus is generally suited for support of an ankle joint, a knee joint, a wrist joint, shoulder joint, elbow joint or hip joint depending on size, shape and securement configurations. In one embodiment, the compression apparatus comprises at least one flexible compression member and at least one securement means configured for adjustably providing compression to the joint area of a wearer. In certain embodiments, an apparatus of the present disclosure may comprise temperature-control means, decorative features, devices for visual display of treatment information such as elevation and temperature, as well as other information useful in treatment.

For injuries to joints, especially synovial joints, rest, ice or heat are typically an integral part of recovery. In a busy lifestyle it is difficult to stay stationary often enough and long enough to thoroughly ice or heat an injured joint area as prescribed. In many cases, patients are limited to ice or heat treatments when they have an opportunity to remain stationary. Time spent waiting for a period of relative immobility represents one or more missed opportunities for a person suffering from a joint injury to administer ice or heat or rest the joint. The shortening of ice and heat rehabilitation sessions can also significantly lengthen a patient's recovery time. Thus, there is a need in the art for a solution that allows a patient suffering from a joint injury the opportunity to ice or heat the injured joint even while on the move.

Compression apparatus for synovial joints and methods of use thereof