A database system including a transaction database system processing device for executing a transaction database process and a decision support database system processing device for executing a decision support process. The database system further includes a transaction database storage device, provided with the transaction database device, for retaining a transaction database created and updated by the transaction database process, a first and second database storage device, each provided with the decision support database device, and each for retaining a first and a second decision database, respectively, for use in a decision support process, a delayed updating device, provided with the decision support database device, for receiving a log created based on the transaction database at each of a predetermined time interval, and for alternatively supplying both the log received at a current predetermined time interval and the log received immediately preceding the current predetermined time interval to the first database storage device and to the second database storage device at each predetermined time interval, and a retrieving device, provided with decision support database device, for executing a retrieving process for the second decision database stored in the second database storage device when the delayed updating device supplies both logs to the first database storage device and for executing a retrieving process for the first decision database stored in the first database storage device when the delayed updating device supplies both logs to the second database storage device.

1. Field of the Invention
This invention pertains to a database system capable of performing more than two [2] kinds of processes simultaneously, such as a hit-transaction database system process and a decision support database system process. More particularly, it pertains to a database system having area for a hit-transaction database system process separate from an area for a decision support database system process, as well as a function for delayed updations of the content in these areas and a function of executing retrieval jobs in the decision support database system.
2. Description of the Related Arts
A database has roughly two [2] kinds of processes. One is a hit-transaction database system process, such as an OLTP (online transaction processing), for simultaneously handling a large number of jobs having relatively lighter workloads with an emphasis on spontaneity. The other is a decision support database system process, e.g. a decision making support by statistically treating data collected by the hit-transaction database system process, having extremely heavy workloads.
If we seek an example in banking, the hit-transaction database system process includes a database access job for dispensing cash to a customer, and the decision support database system process includes a cash flow analysis of a particular financial product.
Conventionally, the hit-transaction database system process is working during a period for an OLTP, while the decision support database system process is ordinarily executed during nighttimes after an OLTP. This is because a decision support database system process may invoke an exclusive control that inhibits an execution of a bulk of the jobs of the hit-transaction database system process, which damages the spontaneity of the hit-transaction database system process.
As such, response time of retrieving data from the decision support database system process has been forgone more or less. Yet, a necessity for a more responsive strategic information system (SIS) have aroused a growing demand of a decision support database system process allowing more contemporary data to be extracted during a period for an OLTP.
When a hit-transaction database system process is working simultaneously with a decision support database system process, while their areas remain separate, a equivalence between the contents of their data areas is maintained as close as possible. A technique is used for this purpose whereby a database updation log generated in the hit-transaction database system process is applied to the data area of the decision support database system process after a predetermined interval.
The following description assumes that an area A refers to the data area of a hit-transaction database system process including a process A, and that an area B refers to the data area of a decision support database system process including a process B. Conventionally, a log obtained as an updated content of area A in the hit-transaction database system process is applied to area B for its delayed updation after a predetermined interval. Process B then uses data, which have updated area A and been copied to area B by its delayed updation.
FIG. 1 is a block diagram of a conventional database system, showing a flow in steps of maintaining a equivalence between data areas.
ST1: A log's secondary storage device temporarily saves a log content in area A pertaining to a database generated by process A. PA1 ST2: At every certain time interval, process B receives the log content read from the log's secondary storage device. PA1 ST3: A delayed updation updates area B. PA1 ST4: Data in area B undergoes process B.
FIG. 2 is a timing chart showing a sequence of delayed updations and retrieval jobs, in relation to logs, executed by the conventional database system shown in FIG. 1.
A method is to allocate to process B (the decision support database system process) the time difference between the time interval allowed for process A (in the hit-transaction database system process) and the time necessary for a delayed updation.
However, this method has such a problem that the less a time interval can be allocated to process A (the basic system process) for reducing the delay caused by a delayed updation the hit-transaction less a time is allocated to process B.
Besides, there is a problem that a response time of retrieving job in the managerial database system may be extended to a time that allowed for a delayed updation thereby increasing a response time in a whole system.

Database management system to alternately perform retrieval process and updating process


In a wireless transceiver station having M antennas, designate an antenna as a target reference antenna (TRA) and for each antenna m other than the TRA: define N distinct paths from antenna m to TRA through zero or more intermediate reference antennas, N is two or more, each distinct paths has a distinct associated set of one or more antenna pairs; for each antenna pair of the sets, estimate an effective forward and backward channel response by sending calibration pilots forth and back between the antenna pair and calculate a reciprocity coefficient for the antenna pair using the estimated channel responses; for each of the N distinct paths, calculate a reciprocity coefficient estimate using the reciprocity coefficients calculated for the set of antenna pairs associated with the path; and combine the N calculated reciprocity coefficient estimates to produce a final reciprocity coefficient estimate for antenna pair (m, target reference antenna).

The New Radio (NR) definition in 3GPP (3rd Generation Partnership Project) for mobile communication systems will encompass a variety of deployment scenarios envisioned for 5G (fifth generation) mobile communication systems. MIMO (multiple input, multiple output) communication systems can be used for 5G TDD (time division duplex) air interfaces. In particular, massive MIMO reciprocity-based TDD air interfaces allow for symbol-level switching and potential configurability that in turn allow for features to support various aspects of 5G air interfaces, for example, enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC) and Ultra-Reliable and Low Latency Communications (URLLC). Example embodiments for massive MIMO communication systems and related reciprocity-based TDD air interfaces are described within U.S. Published Patent Application 2015/0326286, entitled "MASSIVE MIMO ARCHITECTURE," U.S. Published Patent Application 2015/0326383, entitled "SYNCHRONIZATION OF LARGE ANTENNA COUNT SYSTEMS," and U.S. Published Patent Application 2015/0326291, entitled "SIGNALING AND FRAME STRUCTURE FOR MASSIVE MIMO CELLULAR TELECOMMUNICATION SYSTEMS," each of which is hereby incorporated by reference in its entirety.
Many-element antenna arrays, in the order of hundreds of elements per array, are a core component of 5G communications systems. The massive MIMO systems utilize time division duplex (TDD) to separate uplink and downlink. A key implementation requirement is to use knowledge about the wireless channel, obtained in the uplink, to precode signals for the downlink transmission. This technique is referred to as "reciprocity-based precoding." Precoding ensures that multiple mobile stations, with only a few antennas each, receive downlink signals without multi-user interference.
Typically, different radio components are used for uplink and downlink transmission at the base station. Their impact needs to be calibrated accurately (reciprocity calibration) such that uplink channel information can be used for downlink precoding. Inaccurate calibration results in multi-user interference in the downlink, which results in reduced data rates.
Calibration can be implemented internally within the base station array by measuring the channel between individual base station array antenna elements. These measurements need to be accurate. Antenna array calibration accuracy can be severely reduced if the link between a certain antenna element and a reference antenna element is attenuated, for instance, due to array geometry.

Wireless transceiver station with performs multi-path reciprocity calibration with multiple reference antennas


A light branching section applies a light pulse emitted in synchronism with a drive pulse (DP), to an optical fiber line path, and receives the light returning from the line path. An A/D converter performs equivalent sampling on the optical signal contained in the returning light, in synchronism with the sampling pulse (SP) of period T0. A measuring control circuit (MCC) generates DP a number (M) of times. The circuit generates N number of SPs every time it outputs DP. It outputs the SPs, at a time delayed by xcex94T that corresponds to 1/M of the period T0. A clock signal generation circuit outputs to the MCC a first clock signal of a period T1 and a second clock signal of a period T2 different by xcex94t from the period T1. The MCC imparts a delay xcex94T to the SPs, on the basis of the xcex94t.

The present invention relates to an optical time domain reflectometer (hereinafter referred to as an OTDR) and, in particular, to an OTDR for inputting a light pulse into an optical fiber line path and finding an intensity variation of returned light from the optical fiber line path with respect to a time in which the OTDR adopts a technique for achieving an enhanced distance accuracy.
In the case where the test of a communication system using an optical fiber line path is carried out, use is made of an OTDR 10 having a structure as shown in FIG. 7.
That is, this OTDR 10 is so configured as to input a light pulse from a light pulse generation section 12 through a directional couper 11 to an optical fiber line path 1 as a to-be-tested object connected to a connection terminal 10a, receive the light which is returned back from the optical fiber line path 1 at a light receiving unit 13 via-the directional coupler 11, and, while sampling the receiving signal by an analog/digital (A/D) converter 14 with a predetermined frequency, convert it to a digital value.
And this OTDR 10 finds a digital value which is outputted from the A/D converter 14 until a predetermined time elapses from the inputting of the light pulse, as data representing the transmission characteristic of the optical fiber line path 1.
It is to be noted that, in FIG. 7, a measurement control circuit 15 outputs a drive pulse Pd to the light pulse generation section 12 to allow a light pulse to exit in synchronism with the drive pulse Pd while, on the other hand, the control circuit 15 outputs a sampling pulse PS of a predetermined period to the A/D converter 14 a predetermined number of times to allow the sampling of a receiving signal.
In the OTDR 10 thus configured, a resolution as to the time determines a resolution as to the distance of the characteristic of the optical fiber line path 1.
In order to make measurement with a high distance resolution it is necessary to make the period of the sampling pulse Ps of the A/D converter 14 smaller.
However, there is a limitation to the sampling speed of the A/D converter 14 and, in order to maintain the accuracy of the data higher, a problem arises from the fact that it is not preferable to increase the sampling speed up to its limit.
In order to solve this problem, the conventional OTDR 10 does the following.
First, in order to find the characteristic of one optical fiber line path 1 a drive pulse Pd of a predetermined width is outputted an M number of times (it is assumed that M=5) as shown in FIG. 8A.
And, as shown in FIGS. 8B-F, respective N numbers of sampling pulses Ps (1), Ps (2), . . . , Ps (5) are outputted to the A/D converter 14 while delaying their output start timing by a predetermined time xcex94T (1/M of a period T of the sampling pulse Ps) with respect to the output timing of the drive pulse Pd at each number of times.
The system of obtaining a series of data by shifting the sampling start timing by xe2x80x9c1/an integral numberxe2x80x9d of the period of the sampling pulse with respect to the analog signal repeatedly inputted with the same waveform is generally called as an interleave sampling.
By performing such sampling based on this interleave sampling it is possible to obtain data equivalent to the case when a signal received from the incidence of the light pulse into the optical fiber line path 1 until the passage of an Nxc2x7Txe2x88x92xcex94T time is Mxc2x7N times continuously sampled with a period xcex94T shorter than a period T of the sampling pulse PS, as shown in FIG. 8G.
That is, the sampling speed of the A/D converter 14 can be made equivalent to that multiplied M times.
In order to relatively delay the output start timing of the sampling pulse Ps by a predetermined time xcex94T in this way, the conventional OTDR 10 includes the measurement control circuit 15 configured as shown in FIGS. 9 and 10.
In the structure as shown in FIG. 9, a clock signal generation circuit 16 generates a clock signal CKr of a predetermined period T as a reference.
This clock signal CKr is input to a drive pulse generation circuit 17 and to a plurality of delay elements 18 (1), 18 (2), . . . , 18 (M).
The drive pulse generation circuit 17 is so configured that, upon receipt of a start signal for designating a measurement start, it outputs a drive pulse Pd of a predetermined time width, an M number of times, in synchronization with the clock signal CKr with a period longer than N times the period T of the clock signal CKr.
The delay elements 18 (1), 18 (2), . . . , 18 (M) output the inputted clock signals CKr to the select circuit 19 while being delayed by 0, xcex94T, 2xcex94T/, . . . , (Mxe2x88x921) xcex94T.
The select circuit 19 selectively provides, as a sampling pulse Ps, an output out of these outputs of the delay elements 18 (1), 18 (2), . . . , 18 (M) which is designated from a switching circuit 20.
The switching circuit 20 sets the select circuit 19 in a non-select state until receiving a start signal and, upon receipt of the start signal, causes the select circuit 19 to select an output of the delay circuit 18 (1).
When, by doing so, an N number of sampling pulses Ps are outputted from the select circuit 19, the switching circuit 20 again sets the select circuit 19 in a non-select state.
And the switching circuit 20 causes the output of the delay element 18 (2) to be selected by the select circuit 19 upon receipt of the next drive pulse as an output pulse.
By doing so, when a predetermined N number of sampling pulses Ps are outputted from the select circuit 19, the switching circuit 20 again sets the select circuit 19 in a non-select state.
In the same way as set out above, the switching circuit 20 causes the select circuit 19 to select the outputs of the delay elements 18 (3), . . . , 18 (M).
When the output of the last delay element 18(M) is selected by the select circuit 19 and the predetermined number N of sampling pulses Ps are outputted, then the switching circuit 20 causes the select circuit 19 to be set to the non-select state, thus waiting for the inputting of the next start signal.
By the select operation by the switching circuit 20 of the delay elements 18 (1), 18 (2), . . . , 18 (M) it is possible to provide respective N numbers of sampling pulses Ps (1), Ps (2), . . . , Ps (M), as shown in FIGS. 8A to G, to the A/D converter 14 while delaying the output start timing by a predetermined time xcex94T with respect to the output timing of the drive pulse Pd at each number of times.
In an arrangement shown in FIG. 10, a clock signal CKr outputted from a clock signal generation circuit 16 is divided by a frequency divider 21 into, for example, four frequency division parts which are inputted as a frequency divided signal CKd to an integrating circuit 22.
The integrating circuit 22 integrates the frequency divided signal CKd and outputs a ramp function signal V (=xcex1t) for example, with a voltage V increasing from 0 volt in proportion (proportional constant xcex1) to a time t with its high level time point as a reference.
The ramp function signal V, together with a reference voltage Vr from a reference voltage generator 23, is inputted to a comparator 24 where comparison is made between the ramp function signal V and the reference voltage Vr.
At a timing that the ramp function signal V coincides with the reference voltage Vr and the output of the comparator 24 is inverted, a drive pulse generation circuit 17 outputs a drive pulse Pd of a predetermined width while, on the other hand, a sampling pulse generation circuit 25 starts to output an N number of sampling pulses Ps in synchronization with the clock signal CKr.
Until receiving a start signal, the switching circuit 26 sets the reference voltage Vr which is outputted from the reference voltage generator 23 to a voltage higher than a maximal value of the ramp function signal V outputted from the integrating circuit 22 to prevent the output of the comparator 24 from being set in a non-inverting state.
Upon receipt of the start signal, the switching circuit 26 sets the reference voltage Vr to, for example, xcex1xc2x72T during the low level period of the frequency divided signal CKd and, when a 2T time is passed after the frequency divided signal CKd rises to a high level, the output of the comparator 24 is inverted to allow a drive pulse Pd to be outputted and an N number of sampling pulses Ps (1) to start being outputted with its initial pulse put in synchronization with the drive pulse Pd.
It is to be noted that, when the frequency divided signal CKd becomes a low level while the N number of sampling pulses Ps are outputted, the switching circuit 26 sets the reference voltage Vr to a voltage higher than a maximal value of the ramp function signal V and, by doing so, prevents the output of the comparator 24 from being set to a non-inverted state.
During the low level period of the frequency divided signal CKd following the outputting of this first N number of sampling pulses Ps, the switching circuit 26 sets the reference voltage Vr to xcex1 (2Txe2x88x92xcex94T) and, upon the elapsing of a (2Txe2x88x92xcex94T) time after the frequency divided signal CKd rises to a high level, inverts the output of the comparator 24 to allow the drive pulse Pd to be outputted and the outputting of an N number of sampling pulses Ps (2) to be started while being delayed by xcex94T from the output timing of the drive pulse Pd.
In the same way as set out above, the switching circuit 26 switches the reference voltage Vr to xcex1(2Txe2x88x922xcex94T), xcex1 (2Txe2x88x923xcex94T), xcex1 (2Txe2x88x924xcex94T), . . . , xcex1 (T+xcex94T) to allow the outputting of the N number of sampling pulses Ps to be started while being delayed by 2xcex94T, 3xcex94T, 4xcex94T, . . . , (Txe2x88x92xcex94T) from the output timing of the drive pulse Pd and, by doing so, as shown in FIGS. 8A to G, respective N numbers of sampling pulses Ps (1), Ps (2), . . . , Ps (M) are outputted to the A/D converter 14 while delaying their output start timings by xcex94T with respect to the output timing of the drive pulse Pd at each number of times.
However, the time accuracy of such ordinary delay element as used in the arrangement shown in FIG. 9 is very low and it currently has an accuracy limit of several nanoseconds and, in order to obtain more time resolution, it is necessary to use a cable""s delay function.
Incidentally, the delay element using the cable is structurally difficult to manufacture as a smaller unit.
Further, the system using the switching of such delay elements as set out above requires a greater number of elements as the time resolution is enhanced, so that a resultant apparatus becomes bulkier.
In the structure as shown in FIG. 10 in which the clock signal (frequency divided signal) is integrated by the integrating circuit 22 and its output voltage is compared by the comparator 24 with the reference voltage Vr, the accuracy of the delay time is lowered due to the nonlinearity of the integrating circuit 22, thus presenting a problem.
It is accordingly the object of the present invention to solve the above-mentioned problems and to provide an OTDR which can be constructed as a compact unit with high accuracy.
According to one embodiment of the present invention, there is provided an OTDR comprising:
a light pulse generation section (12) for receiving a drive pulse and generating a light pulse in synchronization with the drive pulse;
light branching means (11) for causing the light pulse which exits from the light pulse generation section to be incident into an optical fiber line path (1) as an object of testing, and for taking out returned light from the optical fiber line path;
a light receiving unit (13) for receiving the returned light taken out by the light branching means and converting it to a light receiving signal;
an A/D converter (14) for receiving a sampling pulse of a period T0 and, while subjecting the light receiving signal to equivalent sampling in synchronization with the sampling pulse, converting it to digital data;
a measurement control circuit (31) for generating the drive pulse a plurality of (M) times and outputting it to the light pulse generation section and for generating respective N numbers of sampling pulses relative to an output timing of the drive pulse at each number of times and outputting the sampling pulses to the A/D converter while delaying the respective N generation start timings by xcex94T corresponding to 1/M of the period T0;
clock signal generating means (32) for outputting, to the measurement control circuit, a first clock signal of a period T1 and a second clock signal having a period difference xcex94t equal to a time corresponding to a minimal resolution required of the OTDR relative to the period T1; and
data processing means (48) for obtaining a series of data representing an intensity variation relative to a time elapse of the returned light on the basis of the digital data outputted from the A/D converter, wherein
the measurement control circuit provides a delay of the time xcex94T of the sampling pulse on the basis of a period difference xcex94t of the first clock signal and second clock signal from the clock signal generating means.

Compact optical time domain reflectometer having enhanced accuracy


Lubricating oils useful as gear oils, circulating oils, compressor oils and in other applications characterized by and excellent balance of anti-wear and anti-rust characteristics are based on high quality base stocks including a major portion of a hydrocarbon base fluid such as a PAO with a secondary base stock component which is preferably a long chain alkylated aromatic, such as an alkylnaphthalene. A synergistic combination of additives comprising an adduct of a substituted triazole such as benzotriazole or a substituted benzotriazole, e.g. tolyltriazole (TTZ) with an amine phosphate and a trihydrocarbyl phosphate such as cresyl diphenylphosphate (CDP), confers the desired balance of anti-wear and anti-rust properties. In addition, the present oils typically include an anti-oxidant component and a rust inhibitor together with other optional additive components.

Gear oils and industrial oils are required to meet certain exacting performance specifications. They must exhibit long term stability, implying good resistance to oxidation over a wide range of temperatures coupled with other performance properties including good anti-wear performance. Depending upon the specific application, other performance characteristics may be required. For example, in high temperature circulating oils, high temperature stability must be the main requirement while minimum anti-rust performance is necessary since little water is present at high temperatures. However, in other applications, anti-rust performance becomes important, for example, in wet applications such as use in paper-making machinery.
The properties of oils may be differentiated on the basis of whether they are bulk properties which are not affected significantly by contact with the surface of other materials, for example, the components of a machine or surface-related properties which affect and are affected by the surfaces with which the oil is in contact Oxidation resistance, for instance, belongs largely in the fromer category although the rate at which an oil undergoes oxidation in use is affected by the character of the metal surfaces in contact with the oil. Extreme pressure resistance may also be included in this category. Other properties such as anti-corrosion, anti-rust, anti-wear are directly dependent on the nature of the surfaces--usually metal--with which the oil is in contact during use. The properties which are surface dependent impart another consideration into the formulation of a finished lubricant since the additives which are used to improve the properties of the lubricant base stock and provide the desired balance of properties may be in competition for available sites on the metal surface. For this reason, it is often difficult to obtain a good balance between the performance properties which are surface dependent. One instance of this is with anti-wear and anti-rust properties: it is difficult to produce an oil which possesses both properties in good measure at the same time.
Different types of base stocks have different performance characteristics. Ester base stocks, for example, the neopentyl polyol esters such as the pentaerythritol esters of monobasic carboxylic acids, have excellent high performance properties as indicated by their common use in gas turbine lubricants. They also provide excellent anti-wear characteristics when conventional anti-wear additives are present and they do not have any adverse effect on the performance of rust inhibitors. On the other hand, esters have relatively poor hydrolytic stability, undergoing hydrolysis readily in the presence of water at even moderate temperatures. They are, therefore, less well suited for use in wet applications such as paper-making machinery.
Hydrolytic stability can be improved by the use of hydrocarbon base stocks. The use of alkyl aromatics in combination with the other hydrocarbon base stocks such as hydrogenated polyalphaolefin (PAO) synthetic hydrocarbons and the improved hydrolytic stability of these combinations is described, for example, in U.S. Pat. No. 5,602,086, corresponding to EP 496 486. Traditional formulations containing PAO's, however, present other performance problems. Although the hydrolytic stability of hydrocarbon base stocks including PAOs is superior to that of the esters, it is frequently difficult to obtain a good balance of the surface-related properties such as anti-wear and anti-rust because, as noted above, these surface-related properties are dependent upon the extent to which the additives present in the base stock compete for sites on the metal surfaces which they are intended to protect and high quality hydrocarbon base stocks such as PAOs do not favorably interact with the additives used for this purpose. It is therefore continuing problem to produce a good combination of surface-related properties including anti-wear performance and anti-rust performance in synthetic oils based on hydrocarbon base stocks such as PAO's.


A computer system for language modeling may collect training data from one or more information sources, generate a spoken corpus containing text of transcribed speech, and generate a typed corpus containing typed text. The computer system may derive feature vectors from the spoken corpus, analyze the typed corpus to determine feature vectors representing items of typed text, and generate an unspeakable corpus by filtering the typed corpus to remove each item of typed text represented by a feature vector that is within a similarity threshold of a feature vector derived from the spoken corpus. The computer system may derive feature vectors from the unspeakable corpus and train a classifier to perform discriminative data selection for language modeling based on the feature vectors derived from the spoken corpus and the feature vectors derived from the unspeakable corpus.

Speech recognition systems match sounds with word sequences by utilizing a language model to recognize words and phrases from audio input. For example, a language model can be used for assigning probabilities to word sequences and estimating the relative likelihood of possible matching phrases. Training a language model for use in a speech recognition system typically requires large quantities of text so that many possible word sequences are observed in the training data. Transcribed speech is commonly used as training data but is costly to produce and limits the amount of available training data.

This patent is subject to a terminal disclaimer.

Language modeling based on spoken and unspeakable corpuses


An inkjet head, includes: a pressure chamber communicating with an ink flow channel; a diaphragm linked to the pressure chamber; a piezoelectric element linked to the diaphragm; a nozzle communicating with the pressure chamber; and a vibrating mechanism placed in the ink flow channel and vibrates a supplied ink. Further provided is an inkjet device, including: the above inkjet head; a holding unit that holds a coating object; a moving mechanism that causes relative movement between the inkjet head and the holding unit; and a control unit that controls the inkjet head, the holding unit, and the moving mechanism.

In recent years, an inkjet method that makes it possible to discharge a liquid at high speed has been utilized in order to supply a drug solution or a reagent, or in order to carry out three-dimensional-shape patterning using cells, in the fields of medicine, drug discovery, and biotechnology.
In the publication of Japanese Patent No. 5,540,304, one single nozzle is used to discharge a solution including cells. However, patterning based on one single nozzle has a problem of poor productivity. In recent years, it has been desired to discharge solutions by use of multiple nozzles, in order to improve productivity.
Furthermore, a solution including particles such as cells easily causes sedimentation of the particles. If sedimentation of particles occurs, and the particles remain at the same location for a long time, the particles adhere to one another, thus forming into large grains, or the solution including particles becomes inhomogeneous.
Therefore, the publication of Japanese Patent No. 5,371,678 has proposed a circulation method in which a solution including particles is circulated to suppress sedimentation of the particles.
In particular, in cases where a solution including particles such as cells is discharged by using an inkjet head, it is required that a solution that comes into a state in which the cells are homogenously dispersed is prepared while sedimentation of particles is suppressed, and that the solution is discharged to homogenize the density of the solution. Furthermore, in case where a solution including cells is discharged from multiple nozzles, it is also required that cell densities are evened among multiple nozzles.

Panasonic Intellectual Property Management Co., Ltd.


Methods are described for the processing of biological samples for direct use in nucleic acid amplification without extracting or isolating the nucleic acids from the sample. In preferred embodiments, the processed sample provides the nucleic acid template in PCR-based assays.

Nucleic acids are used frequently in the clinical setting in, for example, the identification of genetic mutations and in the diagnosis of bacterial and/or viral infections. In general, such methods have used nucleic acids isolated or extracted from biological samples.
The most commonly used method for isolating DNA from a biological sample (e.g., blood) involves lysing the cells contained in the sample with a combination of a proteolytic enzyme and a detergent followed by extracting the mixture with an organic solvent, e.g., phenol and chloroform, so that the DNA enters the aqueous phase and the protein enters the organic phase. The DNA in the aqueous phase is then concentrated by alcohol precipitation and resuspended in a suitable volume for analysis. Such methods are, however, time-consuming and require the use toxic reagents.
Methods of stabilizing DNA in body fluids are known (e.g., U.S. Patent Application Publication No. 2003-104251).

Sample processing for nucleic acid amplification

Quest Diagnostics Investments Incorporated


An electrical contact (10) includes a central retention portion (16) adapted for insertion in a printed circuit board hole (38). The retention portion (16) includes first and second beam members (22, 24) and first and second collar sections (18, 20) which are rolled into a substantially cylindrical shape about an axis parallel to the longitudinal axis of the beam members. The length of the beam members is at least as great as the thickness of the printed circuit board (40). The unstressed diameter of the substantially cylindrical retention portion is greater than the diameter of the circuit board hole (38). The retention portion (16) is formed with gaps (42, 44) so that it can be compressed for insertion into the hole (38). Since the spacing between the collar sections (18, 20) is at least as great as the thickness of the circuit board (40), the collar sections are on opposite sides of the circuit board outside the hole when the retention portion is inserted in the hole. Accordingly, the collar sections (18, 20) are free to expand so that the beam members (22, 24) engage the interior wall of the hole (38) to provide mechanical and electrical connections thereto without requiring the use of a soldering process.

This invention relates to electrical contacts and, more particularly, to such a contact which is adapted for insertion and retention in a printed circuit board hole without the requirement of a soldering process. In addition, the present invention is related to such a contact arranged so that an array of stacked printed circuit boards may be electrically interconnected.
When an electrical connector assembly is mounted to a printed circuit board, it is necessary to provide electrical interconnections between the electrical contacts within the connector assembly and wiring traces on and within the printed circuit board. It is conventional to provide an array of plated through holes in the printed circuit board which accept respective contacts therein. The plating in each hole is suitably electrically connected to an appropriate wiring trace. It is further conventional that a soldering process be utilized to electrically and mechanically join the contacts to the walls of the respective holes. It would be desirable to be able to eliminate the soldering process.
It is therefore a primary object of the present invention to provide an electrical contact which may be electrically and mechanically connected to the wall of a circuit board plated through hole without the necessity for soldering the contact in the hole.
There are numerous applications where it is desired to stack printed circuit boards and provide electrical interconnections therebetween. It is therefore a further object of this invention to provide an electrical contact of the type described which is arranged so that it may be electrically interconnected with a similar contact at either of its ends in a stacked array of printed circuit boards.


A chroma-decoder 1 has two SRCs 17 and 21. The first SRC 17 performs down-conversion, changing the sampling rate of a composite video signal sampled with a system clock signal Cs to the sampling rate (14.3 MHz) of an NTSC signal. The signal generated by the SRC 17 is output in synchronism with the system clock signal Cs. The signal is then divided into a luminance signal Y and a color-difference signal C, which are subjected to chroma decoding. The second SRC 21 performs down-conversion, changing the sampling rate of the luminance signal and color-difference signal of the NTSC signal to the sampling rate (13.5 MHz) of an ITU-R601 standard.

1. Field of the Invention
The present invention relates to a video signal that performs so-called "chroma-decoding," thereby to convert composite video signals to digital component signals. More particularly, the invention relates to a video signal processing apparatus that can be used in various broadcasting systems such as NTSC system, PAL system, SECAM system and the like.
2. Description of the Related Art
To output a video signal after receipt of a composite video signal broadcast, the composite video signal is chroma-decoded. More precisely, the composite video signal is decomposed into a luminance signal (Y) and color-difference signals (Cb, Cr). The luminance signal and the color-difference signals constitute a component video signal. The chroma decoding is followed by matrix conversion that converts the component video signal to an RGB signal. The RGB signal is subjected to MPEG encoding. In recent years, a digital circuit performs so-called digital chroma decoding, in which composite video signals are processed, generating component video signals of a digital format.
TV broadcasting systems are broadly classified into three categories. The first category is NTSC system that is employed in Japan, North America, etc. The second is PAL system that is used in Europe, except France, and in South America. The third is SECAM system that is employed in France, Russia, etc.
A digital chroma-decoder of multi type that can be used in various broadcasting systems may be manufactured. In order to manufacture such a digital chroma-decoder, sampling blocks that sample signals of different frequencies, respectively, must be mounted on the substrate. This is because the carrier-wave frequency and modulation scheme of color-difference signals differ from one TV broadcasting system to another. In addition, the digital chroma-decoder of multi type needs to have at least four types of system blocks since the sampling frequency is 13.5 MHz, as defined by the ITU-R601 standard, to generate digital component signals.
If a plurality of system clocks are mounted on one substrate or one semiconductor chip, however, the system clocks interfere with one another, generating interference signals. The interference signals enter, for example, the analog input of the A/D converter, inevitably resulting in beat-like noise on the screen. Hence, system clocks should not be mounted on the substrate or semiconductor chip. In view of this, it is very difficult to manufacture a multi-type, digital choroma-decoder on one substrate or one semiconductor chip.

Video processing apparatus for converting composite video signals to digital component video signals


A liquid detergent system wherein the active content is a combination of an anionic surfactant and a nonionic surfactant in the form of ethoxylated partial glycerol esters of a higher, detergent grade fatty acid and optionally containing a foam stabilizing agent. These systems are particularly useful for formulating shampoos and light duty liquid household cleaning compositions having low eye and skin irritation properties.

1. Field of the Invention
This invention relates to liquid detergent compositions.
2. Description of the Prior Art
To date, most shampoos and light duty household detergent products have been based on the combination of an anionic surfactant and a surface active agent serving as a foam promoter or stabilizer. Exemplary of the anionics for these applications include sodium lauryl sulfate (SLS), sodium lauryl ether sulfate (SLES) and linear alkyl benzene sulfonate (LAS). Generally, the foam promoter is a tertiary amine oxide or an alkanolamide, either of the so-called superamide or of the Kritchevsky type.
All of the aforementioned surface active agents and particularly the anionics are severe eye irritants and are capable of causing mild to moderate skin irritation to some sensitized persons. Lately, there has been a trend toward substantially ameliorating the irritant effects of such compositions by using the anionic in conjunction with an amphoteric type surfactant and combining these compounds with a nonionic surfactant in the form of an ethoxylate of a partial polyol ester of a higher fatty acid.
The state of the art products of this type, such as the so-called baby shampoo formulations, range in the category of "mildly irritating" in accordance with the Draize eye irritation test. While it would be desirable to provide even blander systems in this respect than are now available, the overriding desiratum, however, is that of obtaining like systems which affords the formulator acceptable latitude in regulating viscosity characteristics of the final products. Most detergent compositions of the type herein concerned are marketed as water solutions containing from about 10 to 30 percent active content. About the only means for regulating viscosity at the indicated range of solids content for the prior art systems necessitates the inclusion of common salt. But this expediency is self-defeating inasmuch as the added salt significantly increases the eye irritation properties of the product.

Light duty non-irritating detergent compositions


A semiconductor laser producing visible light includes a first conductivity type semiconductor substrate, a first conductivity type AlGaInP cladding layer containing a first dopant impurity and disposed on the substrate, a semiconductor first spacer layer disposed on the cladding layer, an undoped InGaP active layer disposed on the first spacer layer wherein the first spacer layer inhibits intrusion of the first dopant impurity into the active layer, a semiconductor second spacer layer disposed on the active layer, a second conductivity type AlGaInP light guide layer containing a second dopant impurity and disposed on the active layer wherein the second spacer layer inhibits intrusion of the second dopant impurity into the active layer, a second conductivity type semiconductor current concentration and collection structure disposed on the light guide layer, and first and second electrodes disposed on the substrate and the current concentration and collection structure, respectively.

FIG. 2 is a cross-sectional view showing the structure of a prior art semiconductor laser producing visible light, i.e., light visible to the naked eye. The laser includes an n-type gallium arsenide (GaAs) substrate 1 on which numerous layers are successively disposed. An n-type aluminum gallium indium phosphide (AlGaInP) cladding layer 2 is disposed on the substrate 1, an undoped indium gallium phosphide (InGaP) active layer 4 is disposed on the cladding layer 2, a p-type AlGaInP light guide layer 5 is disposed on the active layer 4, and a p-type InGaP etch stopping layer 6 is disposed on the light guide layer 5. Those layers 2, 4, 5, and 6 are all successively grown on the substrate 1 by conventional techniques, for example, by metal organic chemical vapor deposition (MOCVD). A current blocking layer 12 and mesa structure 13 are disposed on the etch stopping layer 6 to concentrate the current flow in the central portion of the active layer 4 and to form a loss guide structure for transverse oscillation mode stabilization.
To form the mesa structure and current blocking layer, initially a p-type AlGaInP cladding layer 7, a p-type InGaP transition layer 8, and a p-type GaAs contacting layer 9a are successively grown on the etch stopping layer 6. Thereafter, an etching mask is formed on part of the contacting layer 9a and the mesa 13 is formed by etching the unmasked portions of layers 7, 8, and 9a. An etchant that etches AlGaInP far more rapidly than InGaP is employed. Thus, when the etch stopping layer 6 is exposed, the rate of etching declines rapidly and damage to the underlying light guide layer 5 that would occur if the etch stopping layer 6 were absent is avoided.
The current blocking layer 12 of n-type GaAs is grown on the etch stopping layer 6 at both sides of the mesa 13. By using MOCVD or another selective growth process with the etching mask still in place on the remaining contacting layer 9a, the current blocking layer 12 does not grow on top of the mesa 13. Finally, a second p-type contacting layer 9b is grown on the top of the mesa 13 and on the current blocking layer 12 after the etching mask is removed. Electrodes 10 and 11 are formed on the substrate 1 and the second contacting layer 9b, respectively, to complete the semiconductor laser. Either before or after the electrodes are formed, the structure is cleaved to form the opposed facets of the laser.
The prior art laser structure is described above without specification of the relative concentrations of the various elements in the ternary and quaternary alloys. The undoped active layer 4 in a semiconductor laser producing visible light typically is usually approximately Ga.sub.0.5 In.sub.0.5 P. The light guide layer 5 and the cladding layers 2 and 7 are usually approximately Al.sub.0.28 Ga.sub.0.23 In.sub.0.49 P. Likewise, in the structure of FIG. 2, the transition layer 8 is intended to have an energy band gap intermediate those of the layers 7 and 9a to reduce the voltage drop that occurs when the GaAs contacting layer directly contacts the AlGaInP cladding layer. In this laser structure, transverse mode oscillation is stabilized by a loss guide structure. Light produced in the active layer 4 that reaches the current blocking layer 12 is absorbed because of the smaller energy band gap of GaAs. Within the mesa 13, the light is not absorbed because of the larger energy band gap of the AlGaInP cladding layer 7. The loss guide structure concentrates light at the mesa 13, stabilizing the oscillation mode of the laser.
The conductivity types of the layers of the laser of FIG. 2 are determined during growth by including appropriate dopant impurities in the growing layers. For example, the dopant impurity that typically provides p-type conductivity in the light guide layer 5 and the cladding layer 7 is zinc (Zn). The dopant impurity used to produce n-type conductivity in the cladding layer 2 is typically selenium (Se) or silicon (Si). When Zn is employed as a p-type dopant impurity in AlGaInP, e.g., in the light guide layer 5 and the cladding layer 7, it has been observed to have a relatively low degree of electrical activity. In other words, a relatively small proportion, for example, only forty percent, of the incorporated Zn atoms are ionized and act as acceptors. The remainder of the Zn does not affect the electrical properties of the laser. To compensate for that low degree of ionization, a relatively large amount of Zn is incorporated into the growing layers. The diffusion coefficient of Zn in AlGaInP is larger than that in GaInP. As a result of a relatively high concentration of Zn and the relative diffusion coefficients of Zn in the cladding and active layers, unusual dopant impurity concentrations can occur in the laser structure. Those dopant impurity concentration abnormalities are accentuated by a known interaction between Zn and Se.
The unusual dopant impurity concentrations that can occur in the laser structure of FIG. 2 are illustrated in FIG. 3. There, the relative concentrations of Zn and Se in the cladding layer 2, the active layer 4, and the light guide layer 5 are plotted as a function of position. The expected concentration of Zn in the layer 4, absent the high concentration of Zn in the light guide layer 5 and the different diffusion constants of the layers 2 and 7, is illustrated by a broken line. Because of the difference in diffusion coefficients of Zn in the active layer 4 and the light guide layer 5, an abnormally large concentration of Zn can occur near the interface of the active layer 4 and the light guide layer 5, as shown in FIG. 3. The increased Zn concentration and the elevated temperatures employed in growing the various layers of the laser structure cause the Zn to diffuse into the active layer 4 that is desirably neither n-type nor p-type. The abnormally high Zn concentration at the interface effectively provides a high concentration diffusion source, accelerating the intrusion of Zn into the active layer 4. The Zn diffusion can occur during growth of the layers of the semiconductor laser, during other high temperature process steps in the fabrication of the laser, or during operation at elevated temperatures. When the concentration of Zn in the active layer 4 increases, undesired charge carrier recombination occurs in that layer, reducing the light output of the semiconductor laser. To compensate for the reduced light output, the current flowing through the laser may be increased, increasing the operating temperature of the laser, accelerating further Zn diffusion and premature failure, i.e., shortened lifetime, of the laser.

Semiconductor laser producing visible light


Permeation enhancement compositions are disclosed. Said compositions include from 30 to 70 parts by weight ethanol, from 0.1 to 10 parts by weight azone, from 30 to 80 parts by weight water and optionally from 10 to 30 parts by weight propylene glycol, which compositions provide increased percutaneous absorption of a pharmacologically active agent disposed therewith.

Percutaneous or transdermal delivery of pharmacologically active agents has become feasible in recent years largely due to vehicles therefor which allow increased permeation of said agents into the body surface to which applied. Certain advantages are attendant to percutaneous drug delivery such as avoidance of the varied absorption and metabolism which can be encountered by oral therapy, avoidance of first pass hepatic metabolism, improved patient compliance as a result of a simplified therapeutic regimen and the like. In many cases, drugs which would appear to be ideal candidates for percutaneous delivery are found to have such low permeability that they cannot be delivered at therapeutically effective rates. In attempts to obviate this problem, various materials and compositions have been suggested as permeation enhancers to effect the transdermal delivery of the pharmacologically active agent. Among these are the following: dimethyl sulfoxide (U.S. Pat. No. 3,551,554); various 1-substituted azacycloalkan-2-ones including 1-dodecylazacycloheptan-2-one referred to hereinafter as azone (U.S. Pat. Nos. 4,562,075, 4,405,616, 4,326,893 and 3,989,816); sugar esters in combination with sulfoxide or phosphine oxide (U.S. Pat. Nos. 4,130,667, 4,130,643, 4,046,886, 3,952,099 and 3,896,238); lower alkyl amides (U.S. Pat. No. 3,472,931); certain aliphatic sulfoxides (U.S. Pat. No. 3,903,256); a composition containing glycerol monooleate, ethanol and isopropyl myristate (U.S. Pat. No. 4,335,115); a binary mixture of 1-dodecylazacycloheptan-2-one and a compound selected from a diol or a second N-substituted azacycloalkyl-2-one (U.S. Pat. No. 4,557,934); and polyethylene glycol monolaurate (U.S. Pat. No. 4,568,343). None of these references disclose or suggest the permeation enhancement compositions claimed herein for increasing the percutaneous absorption of pharmacologically active agents.

Transdermal flux-enhancing pharmaceutical compositions comprising azone, ethanol and water


This invention aims to provide a method for transport and/or storage of live baits adapted to alleviate a lose occurring in the course of transport and/or storage and to maintain a freshness of the live baits for a long period. The method according to the invention comprises making artificial muddy sand used to transport and/or store live baits. The method comprises the steps of: immersing paper products in artificial seawater to fibrillate the paper products; preparing a mixture of plants cellulose fiber of the paper product fibrillated in the artificial seawater and muddy sand of the live baits' native seashore; and forming granular artificial muddy sand containing an amount of seawater from the mixture.

1. Field of the Invention
This relates to a method for transport and/or storage, a process for preparing artificial muddy sand used for transport and/or storage of live baits for fishing and a contain for live baits.
2. Description of the Related Art
Recently, availability of various live baits for fishing such as Perinereis aibuhitensis Grube have largely depended on import from foreign countries, but a loss of live baits occurring in the course of transport from their habitats to destinations has been noticeable and their surviving rate is said to be as low as in order of 60%. It is important for the live baits to be stored (and/or transported) without deterioration of their freshness. While a method of breeding the live baits in seawater to avoid such deterioration of freshness has been attempted, such method has not been effective to solve the problem. For example, exchange of seawater is troublesome and a period of survival is at most one week. In addition, none of appropriate and simplified methods has been proposed for preparing artificial muddy sand which will be effectively used to transport and/or store the live baits. There has been still another problem such that the live baits creep out from container during transport and/or storage or at a site of fishing, since the live baits have behavior of restoring their vigorous activities at the normal temperature.

Method for transport and/or storage of live baits, process for preparing artificial muddy sand used for transport and/or storage of live baits and container for live baits


Featured are methods for magnetic resonance imaging of a volume, such a volume having susceptibility-generating objects or interfaces having susceptibility mismatches therein. Such a method includes selectively visualizing one of susceptibility-generating objects or interfaces having susceptibility mismatches as hyperintense signals, where such visualizing includes controlling variable imaging parameters so as to control a geometric extent of a signal enhancing effect, m more particular aspects of the present invention, such selectively visualizing includes attenuating or essentially suppressing signals from fat and/or water, namely on-resonant water protons, so as to thereby enhance a signal(s) associated with magnetic susceptibility gradient(s). Also featured are MRI systems, apparatuses and/or applications programs for execution on a computer system controlling the MRI data acquisition process embodying such methods.

Magnetic resonance imaging (MRI) is a noninvasive imaging modality capable of distinguishing a wide variety of objects based on their intrinsic composition and also is an imaging technique that is capable of providing one-, two- or three-dimensional imaging of the object. A conventional MRI system typically includes a main or primary magnet that provides the main static magnetic field Bo, magnetic field gradient coils and radio frequency (RF) coils, which are used for spatial encoding, exciting and detecting the nuclei for imaging. Typically, the main magnet is designed to provide a homogeneous magnetic field in an internal region within the main magnet, for example, in the air space of a large central bore of a solenoid or in the air gap between the magnetic pole plates of a C-type magnet. The patient or object to be imaged is positioned in the homogeneous field region located in such air space. The gradient field and the RF coils are typically located external to the patient or object to be imaged and inside the geometry of the main or primary magnet(s) surrounding the air space. There is shown in U.S. Pat. Nos. 4,689,563; 4,968,937 and 5,990,681, the teachings of which are incorporated herein by reference, some exemplary MRI systems.
In MRI, the uniform magnetic field Bo generated by the main magnet is applied to an imaged object by convention along the Z-axis of a Cartesian coordinate system, the origin of which is within the imaged object. The uniform magnetic field Bo being applied has the effect of aligning the magnetization arising from the nuclei of the atoms comprising the imaged object, along the Z-axis, such nuclei possess a nuclear magnetization due to their having an odd number of protons or neutrons. In response to RF magnetic field pulses of the proper frequency, with field direction orientated within the XY plane, the nuclei resonate at their Larmor frequencies, ω=γBo where γ is called the gyromagnetic ratio. In a typical planar imaging sequence, the RF signal centered about the desired Larmor frequency is applied to the imaged object at the same time a magnetic field gradient Gz is being applied along the Z-axis. This gradient field Gz causes only the nuclei in a slice of limited thickness through the object perpendicular to the Z-axis, to satisfy the resonant condition and thus be excited into resonance.
After excitation of the nuclei in the slice, magnetic field gradients are applied along the X- and Y-axes respectively. The gradient Gx along the X-axis causes the nuclei to precess at different frequencies depending on their position along the X-axis, that is, Gx spatially encodes the precessing nuclei by frequency. Thus, this gradient is often referred to as a frequency encoding or read-out gradient. The Y-axis gradient Gy is incremented through a series of values and encodes the Y position into the rate of change of the phase of the precessing nuclei as a function of gradient amplitude, a process typically referred to as phase encoding.
The quality of the image produced by the MRI techniques is dependent, in part, upon the strength of the magnetic resonance (MR) signal received from the precessing nuclei. For this reason an independent RF coil is often placed in close proximity to the region of interest of the imaged object, more particularly on the surface of the imaged object, in order to improve the strength of the received signal. Such RF coils are sometimes referred to as local coils or surface coils.
There is described in U.S. Pat. No. 4,825,162 a surface coil(s) for use in MRI/NMRI imaging and methods related thereto. In the preferred embodiment of that invention, each surface coil is connected to the input of an associated one of a like plurality of low-input-impedance preamplifiers, which minimizes the interaction between any surface coil and any other surface coils not immediately adjacent thereto. These surface coils can have square, circular and the like geometries. This yields an array of a plurality of closely spaced surface coils, each positioned so as to have substantially no interaction with all adjacent surface coils. A different MR response signal is received at each different one of the surface coils from an associated portion of the sample enclosed within the imaging volume defined by the array. Each different MR response signal is used to construct a different one of plurality of different images from each surface coil. These images are then combined, on a point-by-point basis to produce a single composite MR image of a total sample portion comprised of the MR response signals from the entire array of surface coils.
Common MRI strategies use the relative density of water protons in a sample and the relaxation properties of energy exchange between the local spins with the lattice and with each other to achieve contrast between tissues. The spin-lattice interaction is described by the T1 relaxation time, and the spin-spin interaction is described by the T2 relaxation time. Furthermore, static field inhomogeneities directly affect T2 relaxivity as the local field variations introduce rapid intravoxel dephasing. These inhomogeneities can arise from a variety of sources, but significant mismatches in tissue magnetic susceptibility coefficients between adjacent tissues or objects are an important source. As a result, transverse signal decay occurs much faster and the modified relaxation time is referred to as T2*. Thus, MRI pulse sequences are conventionally designed to extract tissue contrast by exploiting intrinsic differences in the proton density, T1, T2, and T2*.
In general, MRI relies heavily on a homogeneous static field for accurate imaging. Additionally, the object or objects being imaged commonly exhibit a diamagnetic behavior, which means that their magnetic susceptibility values (χ) are both small and negative. In contrast, non-diamagnetic objects may have χ values that are small and positive (paramagnetic) or large and positive (ferromagnetic). Objects that create magnetic field susceptibility typically lead to signal voids in MRI that extend well beyond the area encompassed by these objects (i.e., "bloom artifact"). Moreover, there are many potential sources of signal voids (e.g., absence of signal-generating substance, motion artifacts, magnetic field inhomogeneity, etc.) that have similar hypointense signal intensity in images.
The creation of the signal void is related to the magnetic susceptibility gradients (MSGs) created by the non-diamagnetic object. In turn, MSGs are dependent on many factors, including the magnetic susceptibility value of the non-diamagnetic objects, the environment in which the non-diamagnetic object is placed, the type of pulse sequence used, and the individual imaging parameters associated with the pulse sequence. Therefore, the specificity for localization of susceptibility-generating objects is suboptimal.
Since non-diamagnetic objects affect T1 and T2 relaxation properties, imaging strategies have been adopted either to minimize or maximize the T2* effects of these agents depending on whether the goal is to minimize or maximize the sensitivity to the object, respectively. One method is to acquire T1 and/or T2 maps, which is a time-intensive process, lacks sensitivity, and is difficult to acquire on moving structures.
Other common methods for detecting susceptibility-inducing objects are T2*-weighted images using spin echo (SE) [Hahn, E. L. Spin Echoes. Phys Rev 1950; 80 (4): 580-594], fast spin echo (FSE) [Henning, J., Nauerth, A. and H. Friedburg. RARE imaging: a fast imaging method for clinical MR. Magn Reson Med 1986; 3: 823-833], or gradient echo (GRE) [van der Meulen, P., Groen, J. P. and J. J. Cuppen. Very fast MR imaging by field echoes and small angle excitation. Magn Reson Imaging 1985; 3 (3): 297-299] imaging. T2*-weighted imaging is quite sensitive to MSGs but often creates large signal voids that extend far beyond the source object. Thus, the relationship between the non-diamagnetic object volume and the volume of the hypointensity may not be linear. Furthermore, the negative contrast associated with non-diamagnetic objects can be difficult to discriminate from other potential sources of signal voids (i.e., the absence of tissue, motion artifacts, calcifications, hemorrhage, etc.).
Techniques have been recently proposed to create positive contrast from the susceptibility artifacts created by such non-diamagnetic objects as superparamagnetic iron oxide nanoparticles [Cunningham, C. H., Arai, T., Yang. P., M., McConnell, M. V., Pauly, S. M., and S. M. Conolly. (2004). Positive contrast magnetic imaging of cells labeled with magnetic nanoparticles. Magn Reson Med 2005; 53 (5):999-1005 (2005); Coristine, A. S., Foster, P. J., Deoni, S. C., Heyn, C. and B. K. Rutt (2004). Positive contrast labeling of SPIO loaded cells in cell samples and spinal cord injury. Proc Intl Soc Magn Reson Med 11: 163; and Mani, V., Briley-Saebo, K. C., Itskovich, V. V., Samber, D. D. and Z. A. Fayad. Gradient echo acquisition for superparamagnetic particles with positive contrast (GRASP): sequence characterization in membrane and glass superparamagnetic iron oxide phantoms at 1.5 T and 3 T. Magn Reson Med 2006; 55 (1):126-135.] and paramagnetic ring-tipped catheters [Seppenwoolde, J. H., Viergever, M. A. and Bakker, C. J. Passive tracking exploiting local signal conservation: the white marker phenomenon. Magn Reson Med 2003; 50 (4): 784-790]. The technique proposed by Cunningham et al uses spectrally-selective radio frequency pulses to image a spectral band assumed to be associated with the MSGs. The techniques described in Coristine et al., Seppenwoolde et al., and Mani et al. use a "white marker" method where signal enhancement is created using gradient imbalances such that only a set of spectral frequencies associated with the MSGs is refocused. Both of these methods produce a positive signal, rather than signal voids, however, this is achieved at the cost of a large signal loss. Furthermore, the technique by Cunningham et al. is sensitive to the tuning of the passband and may further attenuate signal from the MSGs. The techniques used by Seppenwoolde et al., Mani et al., and Coristine et al. also require careful consideration of imaging parameters.
Also, interventional MRI is playing an increasingly important role for guiding endovascular procedures. MR-compatible devices for these procedures are often designed to be non-magnetic or to be made from magnetic resonance (MR) invisible using materials, such as nitinol. Thus, localization of the device becomes difficult. To make MR-compatible devices MR-visible, either passive markers are incorporated [Bakker, C. J., Hoogeveen, R. M., Weber, J., van Vaals, J. J., Viergever, M. A. and W. P. Mali. Visualization of dedicated catheters using fast scanning techniques with potential for MR-guided vascular interventions. Magn Reson Med 1996; 36 (6): 816-820; Bakker, C. J., Hoogeveen, R. M., Hurtak, W. F., van Vaals, J. J., Viergever, M. A. and W. P. Mali. MR-guided endovascular interventions: susceptibility-based catheter and near-real-time imaging technique. Radiology 1997; 202 (1): 273-276; Bakker, C. J., Bos, C. and H. J. Weinmann. Passive tracking of catheters and guidewires by contrast-enhanced fluoroscopy. Magn Reson Med 2001; 45 (1): 17-23; Wacker, F. K., Reither, K., Branding, G., Wendt, M. and K. J. Wolf. Magnetic resonance-guided vascular catheterization: feasibility using a passive tracking technique at 0.2 Tesla in a pig model. J Magn Reson Imaging 1999; 10 (5): 841-844], or active coil tracking systems are incorporated [Atalar, E., Bottomley, P. A., Ocali, O., Correia, L. C., Kelemen, M. D., Lima, J. A. and E. A. Zerhouni. High resolution intravascular MRI and MRS by using a catheter receiver coil. Magn Reson Med 1996; 36 (4): 596-605; Dumoulin, C. L., Souza, S. P. and R. D. Darrow. Real-time monitoring of invasive devices using magnetic resonance. Magn Reson Med 1993; 29 (3): 411-415; Erhart, P., Ladd, M. E., Steiner, P., Heske, N., Dumoulin, C. L. and J. F. Debatin. Tissue-independent MR tracking of invasive devices with an internal signal source. Magn Reson Med 1998; 39 (2): 279-284; Ladd, M. E., Zimmermann, G. G., McKinnon, G. C., von Schulthess, G. K., Dumoulin, C. L., Darrow, R. D., Hofmann, E. and J. F. Debatin. Visualization of vascular guidewires using MR tracking. J Magn Reson Imaging 1998; 8 (1): 251-253; Wendt, M., Busch, M., Wetzler, R., Zhang, Q., Melzer, A., Wacker, F., Duerk, J. L. and J. S. Lewin. Shifted rotated keyhole imaging and active tip-tracking for interventional procedure guidance. J Magn Reson Imaging 1998; 8 (1): 258-261] are incorporated. Such incorporation with the device, however, has the negative impact of increasing the device diameter and device complexity.
In addition, chemical analysis of iron from liver needle biopsy specimens is currently the most accepted method of diagnosis of iron storage diseases such as hemochromatosis and thalassemia. However, hepatic iron concentration (HIC) measurements by needle biopsy have several problems including: sampling errors owing to the large variation in HIC from site to site within the liver and the uncomfortable nature of the procedure for patients which limits testing frequency. MRI methods have been used to non-invasively assess iron overload in the liver and heart [Anderson, L. J., Holden, S., Davis, B., Prescott, E. Charrier, C. C., Bunce, N. H., Firmin, D. N., Wonke, B., Porter, J., Walker, J. M. and D. J. Pennell. Cardiovascular T2-star (T2*) magnetic resonance for the early diagnosis of myocardial iron overload. Eur Heart J 2001; 22: 2171-2179; Clark, P. R. and T. G. St. Pierre. Quantitative 1/T2 mapping of hepatic iron overload: a single spin echo imaging methodology. Magn Reson Imaging 2000; 18: 431-438; Jensen, P. D., Jensen, F. T., Christensen, T., Eiskjaer, H., Baandrup, U. and J. L. Nielsen. Evaluation of myocardial iron by magnetic resonance imaging during iron chelation therapy with deferrioxamine: indication of close relation between myocardial iron content and chelatable iron pool. Blood 2003; 101: 4632-4639; Mavrogeni, S. I. Gotsis, E. D., Markussis, V., Tsekos, N., Politis, C., Vretou, E. and D. Kermastinos. T2 relaxation time study of iron overload in β-thalassemia. MAGMA 1998; 6 (1): 7-12; Westwood, M., Anderson, L. J., Firmin, D. J., Gatehouse, P. D., Charrier, C. C. Wonke, B. and D. J. Pennell. A single breath-hold multiecho T2* cardiovascular magnetic resonance technique for diagnosis of myocardial iron overload. J Magn Reson Imaging 2003; 18: 33-39], thereby overcoming sampling errors and allowing more frequent testing. There is still a need, however, for non-invasive measurement techniques that are more sensitive for iron measurement.
A non-invasive MRI technique commonly referred to as BOLD MRI [Ogawa, S., Lee, T. M., Kay, A. R. and D. W. Tank. Brain magnetic resonance imaging with contrast dependent on blood oxygenation. Proc Natl Acad Sci USA 1990; 87 (24): 9868-9872] has been used to assess blood oxygenation, where differences in blood oxygenation are used to modulate signal intensity. Briefly, hemoglobin is the iron-containing respiratory protein of red blood cells that transports oxygen as oxyhemoglobin from the lungs to the tissues. Following delivery of oxygen to the tissues, the oxyhemoglobin becomes deoxyhemoglobin with a resulting change in the magnetic properties of the blood. Deoxyhemoglobin is paramagnetic and thus produces intravascular bulk magnetic field gradients in and around the surrounding tissue. BOLD MRI uses a subtraction technique with T2*-weighted imaging to study blood flow and oxygen utilization. Because of the small signal change generated by the BOLD effect, however, BOLD MRI is typically performed on high-field scanners (3 T or greater). Thus, there continues to be a need to assess blood oxygenation using MRI scanners at lower field strengths (e.g., 1.5 T).
The references discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.
It thus would be desirable to provide a methodology for acquisition of MRI image data where susceptibility-generating objects, including preferably other sources of static field inhomogeneities, as hyperintense signals with the geometric extent of the signal-enhancing effect being controlled by imaging parameters that can be varied as well as MRI systems, MRI apparatuses and software applications programs embodying such methods. It would be particularly desirable to provide such systems, methods and applications programs that would embody a positive contrast method that uses selective suppression methods to attenuate some signals and enhancing signals associated with magnetic susceptibility gradients. It would be particularly desirable to provide such systems, methods and applications programs that would attenuate signals from fat and from water, more specifically on-resonant water. It would be particularly desirable to provide such systems, methods and applications programs that would attenuate signals such as those for fat and/or on-resonant water protons and enhance signals associated with magnetic susceptibility gradients, thereby improving contrast-to-noise ratio and specificity of MSGs in comparison to prior art methods, systems and/or applications programs.

Method for magnetic resonance imaging using inversion recovery with on-resonant water suppression including MRI systems and software embodying same


In a semiconductor substrate having a surface including a first surface region at a first level, a second surface region at a second level lower than the first level, and a step side region linking the first surface region and the second surface region together, a channel region has a triple structure. Thus, a high electric field is formed in a corner portion between the step side region and the second surface region and in the vicinity thereof. A high electric field is also formed in the first surface region. As a result, the efficiency, with which electrons are injected into a floating gate, is considerably increased.

The present invention relates to a nonvolatile semiconductor memory device and a method for fabricating the same, and also relates to a semiconductor integrated circuit device.
In memories for portable units and memory-incorporated logic VLSI's, the technologies for nonvolatile memories have become increasingly important because it is demanded to reduce the costs per bit and to enhance electrical rewrite functions. For such purposes, various structures and fabrication processes have been suggested.
Hereinafter, conventional nonvolatile memories will be described while giving the outlines of such structures and processes.
FIG. 23 shows the cross section of a nonvolatile semiconductor memory device having a so-called "split-gate type" structure. Such a device was suggested by G. Samchisa et al. in IEEE J. Solid-State Circuits, pp. 676, 1987.
In the device shown in FIG. 23, a tunnel oxide film 102, a floating gate 103 and a capacitive insulating film 104 are formed on the upper surface of a semiconductor substrate 101. A control gate 105 is further formed so as to cover the floating gate 103. Also, in the semiconductor substrate 101, a source region 106, which have been doped with an impurity at a high concentration, is formed in a region partially overlapping with the control gate 105, and a drain region 107, which have been doped with an impurity at a high concentration, is formed in a region partially overlapping with the floating gate 103.
The device shown in FIG. 23 has a so-called "split-gate structure" in which the control gate 105 and the floating gate 102 are disposed via the capacitive insulating film over a channel region between the source region 106 and the drain region 107. The floating gate 103 functions as a node in which information is stored and the charged states thereof are made to correspond to "0" and "1" of the information. By utilizing the fact that the threshold voltage as viewed from the control gate 105 is varied in accordance with the amount of charge accumulated in the floating gate 103, the reading of data is performed.
The writing of data utilizes a strong lateral high electric field, which is generated in a boundary between a "drain potential expansion region" in a region immediately under the floating gate 103 and an "inversion channel region" in a region immediately under the control gate 105. By utilizing the phenomenon that channel hot electrons, which have obtained high energy as a result of the acceleration caused by the lateral high electric field, are injected into the oxide film so as to reach the floating gate 102, a relatively high electron injection efficiency is achieved. Such an electron injection is called a "source-side injection".
The erasure of data is performed by taking out the electrons in the floating gate 103 into the drain region 107 by the use of a Fowler-Nordheim (FN) tunneling phenomenon. In order to utilize the FN tunneling phenomenon, a high electric field of about 10.5 MV/cm to about 11 MV/cm is required to be formed in the oxide film 102. Since the tunnel oxide film 102 of the device of the above-cited document is as thick as 20 nm, a high voltage of about 21 V is applied to the drain region 107 when data is erased.
Since the structure shown in FIG. 23 uses the drain region 107 in both cases of writing and erasing data, the compatibility between the operating speed and the reliability is insufficient.
In order to make the operating speed and the reliability compatible, a device shown in FIG. 24 has been proposed. This device was disclosed by S. Kianian et al. in IEEE Symposium VLSI Technology 1994, Digest of Technical Papers, pp. 71.
In the device shown in FIG. 24, a gate oxide film 204, a floating gate 203 and a control gate 205 partially overlapping with the floating gate 203 are formed over a semiconductor substrate 201. In the semiconductor substrate 201, an extremely thick source region 206, which have been doped with an impurity at a high concentration, is formed in a region partially overlapping with the floating gate 203, and a drain region 207, which have been doped with an impurity at a high concentration, is formed in a region partially overlapping with the control gate 205. And the control gate 205 and the floating gate 203 are disposed via a tunnel oxide film 202 over a channel region between the source region 206 and the drain region 207.
The writing of data utilizes a strong lateral high electric field which is generated in a boundary between an "expansion region" of a high potential in the channel region (the "expansion region" has been generated by applying a voltage as high as 11 V to the source region 206) and an "inversion channel region" in a region immediately under the control gate 205. A phenomenon that channel hot electrons, which have obtained high energy by the lateral high electric field, are injected into the oxide film so as to reach the floating gate 203 is utilized. This data write operation is performed by exchanging the voltages to be applied to the source region 206 and the drain region 207 with each other. However, in the other respects, this operation is performed in the same way as the data write operation performed by the device shown in FIG. 23. In the device shown in FIG. 24, the injection efficiency is further increased by the thick source region 206 which is capacitively coupled to the floating gate 203.
The erasure of data is performed by taking out the to electrons in the floating gate 203 into the control gate 205 by applying a voltage of about 14 V to the control gate 205 and by utilizing the FN tunneling phenomenon, thereby trying to improve the erasure characteristics. In the device shown in FIG. 24, the effective channel length is decreased by the thick source region 206 which is employed for increasing the capacitance coupling with the floating gate 203. Thus, this device is not appropriate for further reducing the size of a memory cell.
FIG. 25 shows the cross section of a nonvolatile semiconductor memory device which is designed to shorten a write time or to reduce a write voltage by increasing a write efficiency. This device is disclosed by Nakao, et al. in Japanese Laid-Open Publication No. 7-115142.
The device shown in FIG. 25 uses a semiconductor substrate 301 with a step 302 formed on the surface thereof. The surface of the semiconductor substrate 301 is divided by this step 302 into a surface at a relatively high level (first surface region) and a surface at a relatively low level (second surface region). A tunnel oxide film 303, a floating gate 304, a capacitive insulating film 305 and a control gate 306 are stacked in this order over the step 302. In the surface of the semiconductor substrate 301, a high-concentration source region 307 and a high-concentration drain region 308, both of which have been doped with an impurity at a high concentration, are formed. A thin high-concentration impurity layer (having a thickness of 0.1 .mu.m or less) 309 extends from the high-concentration drain region 308 along the sides of the step 302 to reach the first surface region. Since the thin high-concentration impurity layer 309 functions as a drain region, the region between the high-concentration source region 307 and the high-concentration impurity layer 309 becomes a channel region. The floating gate 103 is formed so as to overlap the channel region and to cover the high-concentration impurity layer 309.
In such a structure, since the floating gate 304 is located in the directions of the velocity vectors of channel hot electrons, the channel hot electron injection efficiency is presumably increased.
Next, a method for fabricating the nonvolatile semiconductor memory device shown in FIG. 25 will be described with reference to FIGS. 26A to 26E.
First, as shown in FIG. 26A, an oxide film 311 is formed as a mask for forming a step in the semiconductor substrate 301 made of p-type silicon. Thereafter, a part of the oxide film in the region where the step is to be formed is etched by a commonly used patterning technique. Then, the semiconductor substrate 301 is etched by using the oxide film 311 as a mask, thereby forming a step in the surface of the semiconductor substrate 301. Subsequently, As ions are implanted into the whole of the step side region and the second surface region at a relatively high dose of 1.0.times.10.sup.15 cm.sup.-2 and with an acceleration energy of 20 keV. This ion implantation is performed by a large-angle-tilt ion implantation technique in which the implantation angle is set at 30 degrees. As a result, as shown in FIG. 26B, the thin high-concentration impurity layer 309 is formed in the whole of the step side region and the second surface region. It is described in the above-cited document that the high-concentration impurity layer 309 thermally diffuses during the fabrication process and it is also described therein that the resulting thickness thereof after the fabrication process is completed becomes 0.05 .mu.m. Next, as shown in FIG. 26C, the oxide film 311 is removed and then the surface of the semiconductor substrate 301 is thermally oxidized, thereby forming the tunnel oxide film 303 as a first insulating layer so that the film has a thickness of 10 nm. Furthermore, CVD poly-silicon having a thickness of 200 nm is deposited thereon, thereby forming the floating gate 304. A second insulating film (thickness: 20 nm) 305 functioning as a capacitive insulating film is formed on the floating gate 304 by thermally oxidizing the surface of the floating gate 304. Thereafter, a CVD poly-silicon film having a thickness of 200 nm is deposited thereon, thereby forming the control gate 306.
The floating gate 304, the capacitive insulating film 305 and the control gate 306 are patterned as shown in FIG. 26D. And then, as shown in FIG. 26E, As ions are implanted into the semiconductor substrate 1 at a dose of 3.0.times.10.sup.15 cm.sup.-2 and with an acceleration energy of 50 keV, thereby forming the high-concentration source region 307 and the high-concentration drain region 308.
In the nonvolatile semiconductor memory device shown in FIG. 25, since the floating gate 304 is formed in the directions of the velocity vectors of channel hot electrons, the channel hot electron injection efficiency is allegedly increased. For such a purpose, a thin drain layer having a symmetric impurity concentration is formed as a high-concentration impurity layer so as to uniformly cover the step by implanting As ions by a large-angle-tilt ion implantation in which the implantation angle is set at 30 degrees, the acceleration energy is set at as low as 20 keV and the dose is set at 1.0.times.10.sup.15 cm.sup.-2. The resulting impurity concentration thereof reaches 1.00.times.10.sup.20 cm.sup.-3.
Since the devices shown in FIGS. 23 and 25 utilize the FN tunneling phenomenon for erasing data, abrupt band bending and a high electric field are generated at the edge of the drain region in the vicinity of the surface thereof, and the holes, which have been generated by the band-to-band tunneling current, are injected into the oxide film. As a result, a variation is caused in erasure characteristics and a retention margin and a write disturb margin are degraded. Particularly when data is erased from a large block, it takes a time 100 times or more as long as the time required for one-bit erasure. Thus, in a memory cell having a weak resistance, the retention margin is seriously degraded. In addition, even when the drain voltage is restricted to about 1.5 V for reading, it is still impossible to suppress the degradation of the read disturb margin.
In the device shown in FIG. 25, since the high-concentration drain layer reaches the surface of the upper part of the step, the electron injection efficiency cannot be increased and the variation in erasure characteristics and the degradation of the write disturb margin and the read disturb margin cannot be suppressed. The reasons thereof are as follows. At the edge of the high-concentration drain layer, a drain potential, which has been applied to the drain region in a corner portion in the upper part of the step, can be retained. However, the horizontal electric field intensity dramatically decreases in the high-concentration drain layer and the energy of hot electrons decreases in the interface with the semiconductor substrate in the step side region. Though some distance differential is generated by the non-equilibrium transportation between the position of the peak of electric field and the position of an average energy peak of electrons, the differential is approximately on the order of a mean free path. In a silicon crystal, the differential is about 10 nm. As the difference between the thickness of the thin drain layer and this value increases, the energy of electrons in the silicon interface in the step side region exponentially decreases so that the electron injection efficiency is decreased. That is to say, this structure requires an extremely thin drain layer. Furthermore, in the high-concentration drain layer, the hot electrons come into contact with the electrons in a thermal equilibrium state, thereby scattering the electrons, making the directions of the electron velocity vectors less aligned with the direction of the electric field and resulting in a decrease of the electron injection efficiency. Thus, for example, if the impurity concentration within the drain layer is symmetrically decreased so as to suppress the scattering of electrons within the drain layer, then the drain potential drops in the extremely thin drain layer formed along the side and the bottom of the step, the drain potential also drops in the corner portion in the upper part of the step and the horizontal electric field intensity decreases between the drain layer and the channel. As a result, the electron injection efficiency also decreases in the step side region.
Moreover, this structure cannot erase data by taking out electrons from the floating gate into the drain layer by utilizing the Fowler-Nordheim (FN) tunneling phenomenon. Since the high-concentration drain layer is in contact with the channel region, it is necessary, for example, to apply an electric field weakening diffusion layer surrounding the high-concentration drain region, in order to suppress the generation of the band-to-band tunneling current during erasure. However, in such a case, the electron injection efficiency is extremely decreased during writing, and such a structure cannot be fabricated at a very small size because of a short channel effect.
Furthermore, even when the drain voltage is restricted to about 1.5 V during reading, the read disturb margin is still degraded by the thin high-concentration drain layer.
An objective of the present invention is providing a nonvolatile semiconductor memory device which can remarkably increase an electron injection efficiency, thereby enabling a high-speed write operation and a low-power-consumption operation.
Another objective of the present invention is providing a nonvolatile semiconductor memory device suitable for very large-scale integration.
Still another objective of the present invention is providing a nonvolatile semiconductor memory device which can erase data by taking out electrons from a floating gate into a control gate or a drain region.
Still another objective of the present invention is providing a nonvolatile semiconductor memory device which can improve the erasure characteristics by suppressing the injection of holes into an oxide film when data is erased.
Still another objective of the present invention is providing a nonvolatile semiconductor memory device which can suppress the degradation of a read disturb margin and which can increase a high-speed read ability.
Yet another objectives of the present invention are providing a method for fabricating the nonvolatile semiconductor memory device and providing a semiconductor integrated circuit device including such a nonvolatile semiconductor memory device.

Nonvolatile semiconductor memory device and method for fabricating the same, and semiconductor integrated circuit device

Matsushita Electric Industrial Co., Ltd.

Halo LSI Design and Device Technologies, Inc.


A method for providing high cooling effectiveness over the entire length of a cooling path (20) by injecting supplemental coolant into the path (20) at one or more selected downstream locations (32,44). Optimal selection of the injection location (32,44) and the ratio of injected flow to main flow will provide a cooling design with superior temperature uniformity and reduced coolant consumption relative to non-supplemented cooling path designs.

Modern combustion turbine engines are being designed to operate at increasingly high combustion gas temperatures in order to improve the efficiency of the engines. Combustion temperatures of over 1,000 degrees C. necessitate the use of new superalloy materials, thermal barrier coatings, and improved component cooling techniques. It is known in the art to utilize a portion of the compressed air generated by the compressor as cooling air for convective cooling of selected portions of the turbine. However, the use of compressed air for this purpose decreases the efficiency of the engine, and therefore, designs that minimize the amount of such cooling air are desired. A typical prior art turbine may have a cooling path formed therein for the passage of cooling air from the compressor. However, as the air flows through the cooling path and removes heat energy from the component, the temperature of the cooling fluid rises. As a result, the effectiveness of the cooling air is higher at the inlet end of the cooling path and lower at the outlet end. This temperature gradient can generate additional stress loading within the component. To provide adequate cooling at the outlet end of the cooling flow path it is necessary to provide a flow rate through the flow path which is higher than necessary for the inlet end. As a result, an excessive quantity of cooling fluid is used and the component may be excessively cooled at the inlet end.
U.S. Pat. No. 5,100,291 issued on Mar. 31, 1992 to Glover discloses a cooling technique that addresses this problem. Glover describes a manifold for providing cooling air to a plurality of radial locations in a turbine, and for providing an immediate exit path for the spent cooling air away from the component being cooled. This approach distributes the cooling capacity more evenly throughout the component, but it requires the installation of additional hardware in the turbine to function as the inlet and exit flow paths.
U.S. Pat. No. 5,472,316 issued on Dec. 5, 1995, to Taslim et al discloses the use of turbulator ribs disposed on at least one side wall of a cooling path in order to promote heat transfer efficiency at selected locations along the flow path. The improvement of heat transfer efficiency results from both the turbulence effect and from the acceleration of the cooling fluid flow rate caused by the reduction in the cross sectional area of the flow path. The use of such turbulators will change the rate of temperature rise of a cooling fluid along a cooling flow path. It does not, however, solve the problem of an unacceptable increase in the temperature of the cooling fluid at the outlet end of the cooling path, nor the resulting excess cooling at the inlet end when the flow rate of the cooling fluid is increased to counteract this temperature rise.
Accordingly, it is an object of this invention to provide a method of cooling a portion of a combustion turbine engine that minimizes the amount of cooling air required and that avoids excessive levels of cooling at the inlet end of a cooling path. It is a further object of this invention to provide a method of cooling a portion of a combustion turbine engine that results in a minimum peak level of stress in the component.


Methods and systems are described for permitting a user to specify the criteria for determining the success or failure of the transmission of an instant message. A computer system first identifies the user specified criteria. When the server computer system receives an instant message, the computer system determines whether the user specified criteria have been met. If the criteria are met, the computer system returns a successful acknowledgement message to the user. Since the user sets the criteria by which success will be determined, the meaning of a successful acknowledgement message will be clear to the user.

1. The Field of the Invention
The present invention relates to the field of electronic communication. In particular, the present invention relates to methods and systems for selecting criteria for a successful acknowledgement message criteria in instant messaging.
2. The Prior State of the Art
Computer networking, and in particular the evolution of the Internet, has transformed the way people communicate and share information. One important technology used in conjunction with computer networks is called "electronic mail" or "e-mail." E-mail allows a sending individual to compose a text message on his/her computer system and then transmit that text message over the computer network to a destination computer system, typically a server computer system, associated with a receiving individual. Once the receiving individual establishes a connection with his/her server computer system, the receiving individual can then retrieve the electronic mail message.
An advantage of electronic mail is that individuals can communicate over very large distances in significantly less time than it would take to physically mail a letter to that location. In addition, modern electronic mail systems allow for the inclusion of "attachments" which may essentially be any file type including text files and even executable files. Thus, entire files can be conveniently transported from one location to another. Once received, the electronic mail text message and any associated attachments are in electronic form and therefore may be easily manipulated by a healthy variety of widely available software packages.
Although electronic mail transmissions typically take less time than physically mailing a letter from one location to another, it can still be a matter of minutes, hours, or even days to transmit an electronic message. In some circumstances, it may be desirable to transmit messages even faster. One technology that enables much faster electronic communication is called "instant messaging."
As the name implies, "instant messaging" permits a sending individual to quickly transmit an electronic message to a receiving individual in a matter of seconds and often within a second. Thus, two individuals can essentially communicate electronically in real time. Instant messaging requires that each individual in the electronic conversation be "logged in." In this description and in the claims, "logged in" means that they either have a dedicated connection to the network such as the Internet used to transmit the instant message, or they are connected to a computer system (typically an instant messaging server) that has a dedicated connection to the network.
When transmitting an instant message, it is often desirable to know whether or not the instant message was successfully delivered. For this reason, acknowledgement messages are often returned back to the instant message sender indicating the success or failure of the instant message transmission.
An acknowledgement message that indicates the successful delivery of an instant message will be referred to in this description and in the claims as a "successful" acknowledgement message. There are several circumstances in which a "successful"acknowledgement message may be returned back to the instant message sender. This ambiguity may leave the sender of the instant message somewhat confused as to the meaning of a "successful" acknowledgement message.
Therefore, what are desired are systems and methods for acknowledging delivery of an instant message in which the meaning of a "successful" acknowledgement message is more clearly defined and understandable to the sender of the instant message.

Methods and systems for selecting criteria for a successful acknowledgement message in instant messaging