An electrocoagulation printing method comprises the steps of (a) providing a positive electrolytically inert electrode having a continuous passivated surface moving at substantially constant speed along a predetermined path, the passivated surface defining a positive electrode active surface; (b) coating the positive electrode active surface with an olefinic substance and silica to form on the surface micro-droplets of olefinic substance containing the silica; (c) forming on the olefin and silica-coated positive electrode active surface a plurality of dots of colored, coagulated colloid representative of a desired image, by electrocoagulation of an electrolytically coagulable colloid present in an electrocoagulation printing ink comprising a liquid colloidal dispersion containing the electrolytically coagulable colloid, a dispersing medium, a soluble electrolyte and a coloring agent; and (d) bringing a substrate into contact with the olefin and silica-coated positive electrode active surface to cause transfer of the dots of colored, coagulated colloid from the surface onto the substrate and thereby imprint the substrate with the image. The use in step (b) of silica prevents abrasion and pitting of the positive electrode, without substantially affecting passivation. The use of silica also prevents the formation of undesirable background on the printed image in step (d).

The present invention pertains to improvements in the field of electrocoagulation printing. More particularly, the invention relates to a method of preventing anode abrasion during electrocoagulation printing.
In U.S. Pat. No. 4,895,629 of Jan. 23, 1990, applicant has described a high-speed electrocoagulation printing method and apparatus in which use is made of a positive electrode in the form of a revolving cylinder having a passivated surface onto which dots of colored, coagulated colloid representative of an image are produced. These dots of colored, coagulated colloid are thereafter contacted with a substrate such as paper to cause transfer of the colored, coagulated colloid onto the substrate and thereby imprint the substrate with the image. As explained in this patent, the positive electrode is coated with a dispersion containing an olefinic substance and a metal oxide prior to electrical energization of the negative electrodes in order to weaken the adherence of the dots of coagulated colloid to the positive electrode and also to prevent an uncontrolled corrosion of the positive electrode. In addition, gas generated as a result of electrolysis upon energizing the negative electrodes is consumed by reaction with the olefinic substance so that there is no gas accumulation between the negative and positive electrodes.
The electrocoagulation printing ink which is injected into the gap defined between the positive and negative electrodes consists essentially of a liquid colloidal dispersion containing an electrolytically coagulable colloid, a dispersing medium, a soluble electrolyte and a coloring agent. Where the coloring agent used is a pigment, a dispersing agent is added for uniformly dispersing the pigment into the ink. After coagulation of the colloid, any remaining non-coagulated colloid is removed from the surface of the positive electrode, for example, by scraping the surface with a soft rubber squeegee, so as to fully uncover the colored, coagulated colloid which is thereafter transferred onto the substrate. The surface of the positive electrode is thereafter cleaned by means of a plurality of rotating brushes and a cleaning liquid to remove any residual coagulated colloid adhered to the surface of the positive electrode.
When a polychromic image is desired, the negative and positive electrodes, the positive electrode coating device, ink injector, rubber squeegee and positive electrode cleaning device are arranged to define a printing unit and several printing units each using a coloring agent of different color are disposed in tandem relation to produce several differently colored images of coagulated colloid which are transferred at respective transfer stations onto the substrate in superimposed relation to provide the desired polychromic image. Alternatively, the printing units can be arranged around a single roller adapted to bring the substrate into contact with the dots of colored, coagulated colloid produced by each printing unit, and the substrate which is in the form of a continuous web is partially wrapped around the roller and passed through the respective transfer stations for being imprinted with the differently colored images in superimposed relation.
Applicant has observed that the metal oxide used in combination with the olefin substance for coating the positive electrode causes abrasion and pitting of the positive electrode so that it is necessary to regrind the surface of such an electrode after every forty hours of printing. This of course requires shutdown of the printing apparatus and removal of the electrode. Where a positive electrode made of stainless steel or aluminum is utilized, Fe.sup.3+ or Al.sup.3+ ions are released from the surface of the electrode as a result of the abrasion and pitting thereof. As explained in Applicant's copending U.S. application Ser. No. 08/376,245, filed on Jan. 23, 1995 these ions crosslink the colloid contained in the ink, resulting in a viscosity increase leading to an ultimate gelation of the ink.
Applicant has also observed that the metal oxide in combination with the olefinic substance retain on the surface of the positive electrode a film of ink which is transferred with the colored, coagulated colloid onto the substrate during contact with same. Thus, when black, cyan, magenta and yellow coloring agents are used to provide a polychromic image, the residual films containing these coloring agents upon being transferred onto the substrate in superimposed relation create on the printed image an undesirable colored background.

Method of preventing anode abrasion during electrocoagulation printing


A method of comparing a first representation of an identifier with a second representation of an identifier is provided. The method includes providing an expression of the first representation, such as a fingerprint, and considering the expression of the first representation against a probability distribution based on the variation in the expression between different example representations of the second representations, to provide a first consideration. The method also provided for considering the expression of the first representations against a probability distribution based on the variation in the expression between different population representations, to provide a second consideration. By using the first consideration and second consideration together it is possible to provide a measure of comparison between the first representation and the second representation.

A variety of situations call for the comparison of markers, including biometric markers. Such situations include a fingerprint, palm print or other such marking, whose source is known, being compared with a fingerprint, palm print or other such marking, whose source is unknown. Improvements in this process to increase speed and/or reliability of operation are desirable.
In the context of forensic science in particular, the consideration of the unknown source fingerprint may require the consideration of a partial print or print produced in less than ideal conditions. The pressure applied when making the mark, substrate and subsequent recovery process can all impact upon the amount and clarity of information available.
Process Overview
The overall process of the comparison is represented schematically in FIG. 1.
After the recovery of the fingerprint and its representation, which may be achieved in one or more of the conventional manners, a representation of the fingerprint is captured. This may be achieved by the consideration of a photograph or other representation of a fingerprint which has been recovered.
In the next stage, the representation is enhanced. The representation is processed to represent it as a purely black and white representation. Thus any colour or shading is removed. This makes subsequent steps easier to operate. The preferred approach is to use Gabor filters for this purpose, but other possibilities exist.
Following on from this part of the stage, the enhanced representation is converted into a format more readily processed. This skeletonisation includes a number of steps. The basic skeletonisation is readily achieved, for instance using a function within the Matlab software (available from The MathWorks Inc). A section of the basic skeleton achieved in this way is illustrated in FIG. 2a. The problem with this basic skeleton is that the ridges 20 often feature relatively short side ridges 22, "hairs", which complicate the pattern and are not a true representation of the fingerprint. Breaks 24 and other features may also be present which are not a true representation of the fingerprint. To counter these issues, the basic skeleton is subjected to a cleaning step and healing step as part of the skeletonisation. The operation of these steps are described in more detail below and gives a clean healed representation, FIG. 2b.
Once the enhanced representation of the recovered fingerprint has been processed to give a clean and healed representation, the data from it to be compared with the other print can be considered. To do this involves first the extraction of representation data which accurately reflects the configuration of the fingerprint present, but which is suitable for use in the comparison process. The extraction of representation data stage is explained in more detail below, but basically involves the use of one of a number of possible techniques.
The first of the possible techniques, see FIG. 3, involves defining the position of features 30 (such as ridge ends 32 or bifurcation points 34), forming an array of triangles 36 with the features 30 defining the apex of those triangles 36 and using this and other representation data in the comparison stage.
In a second technique, developed by the applicant, the positions of features are defined and the positions of a group of these are considered to define a center. The center defines one apex of the triangles, with adjoining features defining the other apexes.
To facilitate the comparison stage, the representation data extracted is formatted before it is used in the comparison stage. This basically involves presenting the information characteristic of the triangles, quadrilaterals or other polygons being considered when the data is extracted in a format mathematically coded for use in the comparison stage. Further details of the format are described below.
Now that the fingerprint has been expressed as representation data, it can be compared with the other fingerprint(s). The comparison stage is based on different representation data being compared to that previously suggested. Additionally, in making the comparison, the technique goes further than indicating that the known and unknown source prints came from the same source or that they did not. Instead, an expression of the likelihood that they came from the same source is generated. In the preferred forms, one or both of the two different models (a data driven approach and a model driven approach) both described in more detail below are used.
Having provided an overview of the entire process, the stages and steps in them will now be discussed in more detail.
Cleaning and Healing Steps of the Skeletonisation Stage
Some existing attempts at interpreting the basic skeleton to give an improved version have been made.
In the situation illustrated in FIG. 4, the basic skeleton suggests that a ridge island 40 is present, as well as a short ridge 41 which as a result gives a bifurcation point 43 and ridge end 44.
The existing interpretation considers the length of the ridge island 40. If the length is equal to or greater than a predetermined length value then it is deemed a true ridge island and is left. If the length is less than the predetermined length then the ridge island is discarded. In a similar manner, the length from the bifurcation point 43 to the ridge end 44 is considered. Again if it is equal to or greater than the predetermined length it is kept as a ridge with its attendant features. If it is shorter than the predetermined length it is discarded. This approach is slow in terms of its processing as the length in all cases is measured by starting at the feature and then advancing pixel by pixel until the end is reached. The speed is a major issue as there are a lot of such features need to be considered within a print.
The new approach now described has amongst its aims to provide a reliable, faster means for handling such a situation. Instead of advancing pixel by pixel, the new approach illustrated in FIG. 5 considers the print in a series of sections or neighborhoods. Thus a neighborhood definition, box 50, is applied to part of the print. Features within that neighborhood 50 are then quickly established by considering any pixel which is only connected to one other. This points to features 51 and 52 which represent ridge ends within the neighborhood 50. The start point for the data set forming a feature is then determined relative to the neighborhood 50. In the case of feature 51 this is the bifurcation feature 53. In the case of feature 52 this is the neighborhood boundary crossing 54. Thus feature 51 is part of data set A extending between feature 53 and feature 51. Feature 52 is a part of separate data set, data set B, extending between crossing 54 and feature 52. All data sets formed by a feature at both ends, with both features being within the neighborhood 50 are discarded as being too short to be true features. All data sets formed by a feature at one end and a crossing at the other are kept as far as the cleaning of that neighborhood is concerned. Thus feature 51 and its attendant data set are discarded (including the bifurcation feature 53) and feature 52 is kept by this cleaning for this neighborhood 50.
When further neighborhoods are considered, it may of course be that the feature 52 is itself part of a data set with the features both within that neighborhood, where upon it too will be discarded. If, however, it is the end of a ridge of significant length then for all neighborhoods considered its data set will start with the feature and end with a crossing and so be kept.
This approach can be used to address all ridge ends and attendant bifurcation features within the print to be cleaned.
As well as addressing "extra" data by cleaning, the present invention also addresses the type of situation illustrated in FIG. 6 where the basic skeleton shows a first ridge end 60 and a second 61, generally opposing one another, but with a gap 62 between them. Is this a single ridge which needs healing by adding data to join the two ends together? Or is this truly two ridge ends?
Not only is it desirable to address this type of situation, but it also must be done in a way which does not detract from the accuracy of the subsequent process, and in particular the generation of the representative data which follows. This is particularly important in the case where the "direction" is a part of the representative data generated, as proposed for the embodiment of the invention detailed below.
To ensure that the "direction" information is not impaired it must be accurately determined and maintained. The pixel by pixel approach of the type used above for cleaning, suggests taking a feature and then moved pixel by pixel away from it for a given length. A projected line between the feature and the pixel the right length away then gives the angle. Again the pixel by pixel approach is labourious and time consuming.
The approach of the present invention is illustrated in FIG. 7 and is again based on the neighborhood approach. A neighborhood 70 is defined relative to a part of the print. In this case, the part of the print includes a ridge end 71 and bifurcation 72. Also present are points where the ridges cross the boundaries of the neighborhood, crossings 73, 74, 75, 76. Again the crossings and features define a series of data sets. In this case, ridge end 71 and crossing 73 define data set W; bifurcation 72 and crossing 74 define data set X; bifurcation 72 and crossing 75 define data set Y; and bifurcation 72 and crossing 76 define data set Z.
The direction of data set W is defined by a line drawn between ridge end 71 and crossing 73. A similar determination can be made for the direction of the other data sets.
Once the directions for data sets have been obtained, the type of situation shown in FIG. 6 is addressed by considering the direction of the ridge ending in first ridge end 60 and the direction of the ridge ending in second ridge end 61. If the two directions are the same, within the bounds of a limited range, and the separation is small (for instance, the gap falls with the neighborhood) then the gap is healed and the two ridge ends 60, 61 disappear as features as far as further consideration is required. If the separation is too large and/or if the directions do not match, then no healing occurs and the ridge ends 60, 61 are accepted as genuine.
The approach taken in the present invention allows faster processing of the cleaning and healing stage, in a manner which is accurate and is not to the detriment of subsequent stages and steps.
Extraction of Representation Data
Preferably after the above mentioned processing, the necessary data from it to be compared with the other print can be extracted in a way which accurately reflects the configuration of the fingerprint present, but which is suitable for use in the comparison process.
It is possible to fix coordinate axes to the representation and define the features/directions taken relative to that. However, this leads to problems when considering the impact of rotation and a high degree of interrelationship being present between data
Instead of this approach, with reference to FIG. 8, one approach of the present invention will now be explained. Within the illustration, a first bifurcation feature 80, second 81 and ridge end 83 are present. These form nodes which are then joined to one another so that a triangle is formed. Extrapolation of this process to a larger number of minutia features gives a large number of triangles. A print can typically be represented by 50 to 70 such triangles. The Delaunay triangulation approach is preferred.
Whilst this one approach is suitable for use in the new mathematical coding of the information extracted set out below, the use of Delaunay triangulation does not extract the data in the most robust way.
In the alternative approach, developed by the applicant, an entirely new approach is taken. Referring to FIG. 9 a series of features 120a through 1201 are identified within a representation 122. A number of approaches can be used to identify the features to include in a series. Firstly, it is possible to identify all features in the representation and join features together to form triangles (for instance, using Delauney triangulation). Having done so, one of the triangles is selected and this provides the first three features of the series. One of the adjoining triangles to the first triangle is then selected at random and this provides a further feature for the series. Another triangle adjoining the pair is then selected randomly and so on until the desired number of features are in the series. In a second approach, a feature is selected (for instance, at random) and all features within a given radius of the first feature are included in the series. The radius is gradually increased until the series includes the desired number of features.
Having established the series of features, the position of each of these features is considered and used to define a centre 124. Preferably, and as illustrated in this embodiment this is done by considering the X and Y position of each of the features and obtaining a mean for each. The mean X position and mean Y position define the centre 124 for that group of features 120a through 1201. Other approaches to the determination of the centre are perfectly useable. Instead of defining triangles with features at each apex, the new approach uses the centre 124 as one of the apexes for each of the triangles. The other two apexes for first triangle 126 are formed by features 120a and 120b. The next triangle 128 is formed by centre 124, feature 120b and 120c. Other triangles are formed in a similar way, preferably moving around the centre 124 in sequence. The set of triangles formed in this approach is unique, simple and easy to describe data set. The approach is more robust than the Delaunay triangulation described previously, particularly in relation to distortion. Furthermore, the improvement is achieved without massively increasing the amount of data that needs to be stored and/or the computing power needed to process it. For comparison purposes, FIG. 10 illustrates the Delaunay triangulation approach applied to the same set of features.
Either the first, Delaunay triangulation, based approach or the second, radial triangulation, approach extract data which is suitable for formatting according to the preferred approach of the present process.
Format of Representative Data
Having considered the print in one of the above mentioned ways to extract the representative data, the data must be suitably mathematically coded to allow the comparison process and here a different approach is taken to that considered before. The approach presents the extracted data in vector form, and so allows easy comparison between expressions of different representations.
Particularly with reference to the first approach, for a given triangle, a number of pieces of information are taken and used to form a feature vector. The information is: the type of the minutia feature each node represents (three pieces of information in total); the relative direction of the minutia features (three pieces of information in total); and the distances between the nodes (three pieces of information in total). Thus the feature vector is formed of nine pieces of information. The type of minutia can be either ridge end or bifurcation. The direction, a number between 0 and 2π radians, is calculated relative to the orientation, a number between 0 and π radians, of the opposing segment of the triangle as reference and so the parameters of the triangle are independent from the image.
In particular the feature vector may be expressed as:FV=[GP,Reg,{T1,A1,D1,2,T2,A2,D2,3,T3,A3,D3,1}]where
GP is the general pattern of the fingerprint;
Reg is the region of the fingerprint the triangle is in;
T1 is the type of minutia 1;
A1 is the direction of the minutia at location 1 relative to the direction of the opposing side of the triangle;
D1,2 is the length of the triangle side between minutia 1 and minutia 2;
T2 is the type of minutia 2;
A2 is the direction of the minutia at location 2 relative to the direction of the opposing side of the triangle;
D2,3 is the length of the triangle side between minutia 2 and minutia 3;
T3 is the type of minutia 3;
A3 is the direction of the minutia at location 3 relative to the direction of the opposing side of the triangle;
D3,1 is the length of the triangle side between minutia 3 and minutia 1.
To avoid the same feature vector representing two symmetrical triangles, the features are recorded for all the triangles in the same order (either clockwise or anticlockwise). A rule of starting with the furthest feature to the left is used, but other such rules could be applied.
As each triangle considered is independent of the others and is also independent of the print image this addresses the problem of rotational issues in the comparison.
Advantageously the second data extraction approach described above is also suited to be mathematically coded using the vector format and so allow comparison with data extracted from other representations. The pieces of information used to form the feature vector in this case are: the general pattern of the fingerprint; the type of minutia; the direction of the minutia relative to the image; the radius of the minutia from the centre or centroid; the length of the polygon side between a minutia and the minutia next to it; the surface area of the triangle defined by the minutia, the minutia next to it and the centroid.
In particular the vector may be expressed as:FV=[GP,{T1,A1,R1,L1,2,S1}, . . . ,{Tk,Ak,Rk,Lk,k+1,Sk}, . . . ,{TN,AN,RN,LN,1,SN}]where
GP is the general pattern of the fingerprint;
Tk is the type of minutia i;
Ak is the direction of minutia k relative to the image;
Lk,k+1 is the length of the polygon side between minutia k and minutia k+1;
Sk is the surface area of the triangle defined by minutia k, k+1 and the centroid; and
Rk is the radius between the centroid and the minutia k
When compared with the expression of the vector set out above in the context of the approach taken for the first data extraction approach, it should be noted that region of the fingerprint is no longer considered. The set of features can extend across region boundaries and so it is potentially not appropriate to consider one region in the vector. The region could still be considered, however, and the expression set out below is a suitable one in that context, with the region designated Reg and the other symbols having the meanings outlined above. Note a separate region is possible for each minutia.FV=[GP,{T1,A1,R1,Reg1,L1,2,S1}, . . . ,{Tk,Ak,Rk,Regk,Lk,k+1,Sk}, . . . ,{TN,AN,RN,RegN,LN,1,SN}]
Using the types of format described above, it is possible to present the data extracted from the representations in a format particularly useful to the comparison stage.
Comparison Approaches
A number of different approaches to the comparison between a feature vector of the above mentioned type which represent the print from an unknown source with the a feature vector which represent the print from the known source are possible. A match/not match result may simply be stated. However, substantial benefits exist in making the comparison in such a way that a measure of the strength of a match can be stated.
Likelihood Ratio Approach
One general type of approach that can be taken, which allows the comparison to be expressed in terms of a measure of the strength of the match is through the use of a likelihood ratio.
The likelihood ratio is the quotient of two probabilities, one being that of two feature vectors conditioned on their being from the same source, the other two feature vectors being conditioned on their being from different sources. Feature vectors obtained according to the first data extraction approach and/or second extraction approach described above can be compared in this way, the differences being in the data represented in the feature vectors rather than in the comparison stage itself.
In each case, therefore, the approach can be derived from the expression:
  LR  =            Pr                    (                              fv            s                    ,                                    fv              m                        ❘            Hp                          )                    Pr                    (                              fv            s                    ,                                    fv              m                        ❘            Hd                          )
Where the feature vector fv contains the information extracted from the representation and formatted. The addition of the subscript s to this abbreviation denotes that a feature vector comes from the suspect, and the addition of the subscript m denotes that a feature vector originates from the crime. The symbol fvs then denotes a feature vector from the known source or suspect, and fvm denoted the feature vector originated from an unknown source from the crime scene. For modelling purposes it is useful to classify a feature vector into discrete quantities (which may include general pattern, region, type, and other data) and continuous quantities (which may include the distances between minutiae, relative directions and other data).
The preferred forms for the quotient in the context of the first approach and second approach are discussed in more detail below in the context of their use in the data driven approach to the comparison stage.
Within the general concept of a likelihood ratio approach, a number of ways of implementing such an approach exist. One such approach which allows the comparison to be expressed in terms of a measure of the strength of the match is through the use of a data driven approach.
Data Driven Approach
In general terms, the data driven approach involves the consideration of a quotient defined by a numerator which considers the variation in the data which is extracted from different representations of the same fingerprint and by a denominator which considers the variation in the data which is extracted from representations of different fingerprints. The output of the quotient is a likelihood ratio.
In order to quantify the likelihood ratio, the feature vector for the first representation, the crime scene, and the feature vector for the second representation, the suspect are obtained, as described above. The difference between the two vectors is effectively the distance between the two vectors. Once the distance has been obtained it is compared with two different probability distributions obtained from two different databases.
In the first instance, the probability distribution for these distances is estimated from a database of prints taken from the same finger. A large number of pairings of prints are taken from the database and the distance between them is obtained. This involves a similar approach to that described above. Each of the prints has data extracted from it and that data is formatted as a feature vector. The differences between the two feature vectors give the distance between that pairing. Repeating this process for a large number of pairings gives a range of distances with different frequencies of occurrence. A probability distribution reflecting the variation between prints of the same figure is thus obtained.
Ideally, the database would be obtained from a number of prints taken from the same finger of the suspect. However, the approach can still be applied where the prints are taken from the same finger, but that finger is someone's other than the suspect. This database needs to reflect how a print (more particularly the resulting triangles and their respective feature vectors) from the same finger changes with pressure and substrate. This database is formed from a significant number of sets of information, each set being a large number of prints taken from the same finger under the full range of conditions encountered in practice. The database is populated by the identification, by an operator, of corresponding triangles in several applications of the same finger. Alternatively, a smaller set of prints can be processed as described above, distortion functions can then be calculated. The prefer method is thin plate splines, but other methods exist. The distortion function can then be applied to other prints to simulate further sets of data.
In the second instance, the probability distribution for these distances is estimated from a database of prints taken from different fingers. Again a large number of pairings of prints are taken from the database and the distance between them obtained. The extraction of data, formatting as a feature vector, calculation of the distance using the two feature vectors and determination of the distribution is performed in the same way, but uses the different database.
This different database needs to reflect how a print (more particularly the resulting triangles and their respective feature vectors) from a number of different fingers varies between fingers and, potentially, with various pressures and substrates involved. Again, the database is populated by the identification, by an operator, of triangles in the various representations obtained from the different fingers of different persons.
Having established the manner in which the databases and probability distributions are obtained, the comparison of a crime scene print against a suspect print is considered further.
The numerator may thus be thought of as considering a first representation obtained from a crime scene or an item linked to a crime, against a second representation from a suspect through an approach involving:                taking and/or generating a number of example representations of the second representation;        considering the example representations as a number of triangles;        considering the value of the feature vector for a given triangle in respect of each of the example representations;        obtaining the feature vector value of the first representation;        forming a probability distribution of the frequency of the cross-differences of different feature vector values for a given triangle between example representations;
comparing the difference of the feature vector value of the first representation and the feature vector value of the second representation with the probability distribution.
The denominator may thus be thought of as considering the second representation obtained from a suspect against a series of representations taken from a population through an approach involving:                taking or generating a number of example representations of representations taken from a population;        considering the example representations as a number of triangles;        considering the values of the feature vectors in respect of each of the example representations;        forming a probability distribution of the frequency of differences between the feature vector of the first representation and the different feature vector values from the example representations;        obtaining the feature vector value of the second representation;        comparing the difference between the feature vector value of the first representation and the feature vector value of the second representation with the probability distribution.
Applying the data driven approach, and in the context of the first data extraction approach (Delaunay triangulation), and after some algebraic operations, a probability for the numerator of the likelihood ratio is computed using the following formula:—Num=Σ{Pr(d(fvs,c,fvm,c)|fvs,d,fvm,d,Hp): for all fvs,d and fvm,d such that fvs,d=fvm,d}where
fv means feature vector, c means continuous, d means discrete, m means mark and s means suspect and therefore:
fvm,c: continuous data of the feature vector from the mark
fvm,d: discrete data of the feature vector from the mark
fvs,c: discrete data of the feature vector from the suspect
fvs,d: discrete data of the feature vector from the suspect
d(fvs,c, fvm,c) is the distance measured between the continuous data of the two feature vectors from the mark and the suspect
Hp is the prosecution hypothesis, that is the two feature vectors originate from the same source.
Notice that, conditioning on Hp, suggests fvs,c and fvm,c become measurements extracted from the same finger of the same person. The subscript in the summation symbol means that the probabilities in the right-hand-side of equation are added up for all the cases where the values of the discrete quantities of the features vectors coincide. In some occasions some or all of the discrete variables are present in the fingermark. For these cases the index of the summation is replaced by values of the quantities that are not present. The summation symbol is removed when all discrete quantities are present in the fingermark.
The expression d(fvs,c, fvm,c) denotes a distance between the continuous quantities of the feature vectors for the prints. The continuous quantities in a feature vector are the length of the triangle sides and minutia direction relative to the opposite side of the triangle. There are a number of distance measures that can be used but the distance measure describe below is preferred. This distance measure is computed by first subtracting term by term. The result is a vector containing nine quantities. This is then normalised to ensure that the length and angle are given equal weighting. By taking the sum of the squares of the distances from all the feature vectors considered in this way a single value is obtained.
In such a case, and after some algebraic operations, a probability for the denominator of the likelihood ratio is computed using the following formula,Den=Σ{Pr(d(fvs,c,fvm,c)|fvs,d,fvm,d,Hd)Pr(fvm,d|Hd): for all fvs,d and fvm,d such that fvs,d=fvm,d}where
fv means feature vector, c means continuous, d means discrete, m means mark and s means suspect. and therefore:
fvm,c: continuous data of the feature vector from the mark
fvm,d: discrete data of the feature vector from the mark
fvs,c: discrete data of the feature vector from the suspect
fvs,d: discrete data of the feature vector from the suspect
d(fvs,c, fvm,c) is the distance measured between the continuous data of the two feature vectors from the mark and the suspect
Hd is the defence hypothesis, that is the two feature vectors originate from different sources.
Several distance measures exist but the one described above is preferred. The subscript in the summation symbol means that the probabilities in the right-hand-side of this equation are added up for all the cases where the values of the discrete quantities of the features vectors coincide. In some occasions some or all of the discrete variables are present in the fingermark. For these cases the index of the summation is replaced by values of the quantities that are not present. The summation symbol is removed when all discrete quantities are present in the fingermark.
Conditioning on Hd, that is "the prints originated from different sources", the features vectors come from different fingers of different people. The probability distribution for distances d(fvs,c, fvm,c) can be estimated from a reference database of fingerprints. This database needs to reflect how much variability there is in respect of all prints (again more particularly the resulting triangles and their feature vectors) between different sources. This database can readily be formed by taking existing records of different source fingerprints and analysing them in the above mentioned way.
The second factor Pr(fvm,d|Hd) is a probability distribution of discrete variables including general pattern. A probability distribution for general pattern was computed based on frequencies compiled by the FBI for the National Crime Information Center in 1993. These data can be found on http://home.att.net/˜dermatoglyphics/mfre/. A probability distribution for the remaining discrete variables can be estimated from a reference database using a number of methods. A probability tree is preferred because it can more efficiently code the asymmetry of this distribution, for example, the number of regions depends on the general pattern.
Again applying the data driven approach, and in the context of the second data extraction approach (radial triangulation), a probability for the numerator of the likelihood ratio is computed using the following formula:Num=Pr(d(fvsfvm)|Hp)where
d(fvsfvm) is the distance measured between discrete and continuous data of the two feature vectors from the mark and suspect;
Hp is the prosecution hypothesis, that is the two vectors originate from the same source.
The probability for the numerator is computed using the following formula:Den=Pr(d(fvsfvm)|Hd)where
Hd is the defence hypothesis, that is the two vectors originate from different sources.
In each case, similar approaches to those detailed above can be used to generate the relevant probability distributions.
In the second approach, it is possible to measure the distance between feature vectors in the above described manner of the first data extraction approach in respect of each orientation of the polygon in the mark and suspect representations. However, the large number of minutia which may now be being considered in a feature vector (for instance 12) would mean that there are very many rotations (for instance 12 rotations) of the feature vector which must be considered, compared with the more practical three of the first approach. The use of a greater number of minutia is desirable as this increases the discriminating power of the process. Investigations to date suggest that by the time 12 minutia are being considered, there is little or no overlap between the within finger distribution and between finger distributions illustrated in FIG. 11.
In a modification, therefore, a feature vector is first considered against another feature vector in terms of only part of the information it contains. In particular, the information apart from the minutia direction can be compared. In the comparison, the data set included in one of the vectors is fixed in orientation and the data set included in the other vector with which it is being compared is rotated. If the data set relates to three minutia then three rotations would be considered, if it related to twelve then twelve rotations would be used. The extent of the fit at each position is considered and the best fit rotation obtained. This leads to the association of minutiae pairs across both feature vectors.
In respect of the best fit rotation, in each case, the process then goes on to compare the remaining data in each set, the minutia direction. To achieve this, the minutiae directions are made independent of the orientation of the print on the image. The approach taken on direction is described with reference to FIG. 13a through 13c. In FIG. 13a, a mark set of minutia 200 and a suspect set of minutia 202 are being considered against one another. Each set is formed of four minutia, 204a, 204b, 204c, 204d and 206a, 206b, 206c, 206d respectively. The allocation of the minutia reference numerals reflects the suggested best match between the two sets arising from the consideration of the minutia type, length of the polygon sides between minutia, surface of the polygon defined by the minutia and centroid. Each of the minutia has an associated direction 208a, 208b, 208c, 208d and 210a, 210b, 210c, 210d respectively. For the mark set 200 and the suspect set 202, a circle 212, 214 of radius one is taken. To the mark circle 212 is added a radius 216 for each of the minutia directions, see FIG. 13b. To the suspect circle 214 is added a radius 218 from each of the minutia directions, FIG. 13b. Rotation of one of the circles relative to the other allows the orientation of the minutia to be brought into agreement, according to the set of the pairs of minutiae that were determined before, FIG. 13c, and allows the extent of the match in terms of the minutiae directions for each pair of minutiae to be considered. In the illustrated case there is extensive agreement between the two circles and hence between the two marks in respect of the data being considered.
In effect, the match between the polygons is being considered in terms of the minutia type, distance between minutia, radius between the minutia and the centroid, surface area of the triangle defined between the minutia and the centroid and minutia direction. All of these considerations serve to compliment one another in the comparison process. One or more may be omitted, however, and a practical comparison be carried out.
The comparison provides a distance which can be considered against the two distributions in the manner previously described with reference to FIGS. 11 and 12 below. Various means can be used for computing the distance, including algorithms (such as Euclidean, Pearson, Manhattan etc) or using neural networks.
Assessing a Comparison Using the Data Driven Approaches
Having extracted the data, formatted it in feature vector form and compared two feature vectors to obtain the distance between them, that distance is compared with the two probability distributions obtained from the two databases to give the assessment of match between the first and second representation.
In FIG. 11, the distribution for prints from the same finger is shown, S, and shows good correspondence between examples apart from in cases of extreme distortion or lack of clarity. Almost the entire distribution is close to the vertical axis. Also shown is the distribution for prints from the fingers of different individuals, D. This shows a significant spread from a low number of extremely different cases, to an average of very different and with a number of little different cases. The distribution is spread widely across the horizontal axis.
In FIG. 12, these distributions are considered against a distance I obtained from the comparison of an unknown source (for instance, crime scene) and known source (for instance, suspect) fingerprint in the manner described above. At this distance, I, the values (Q and R respectively) of the distributions S and D can be taken, dotted lines. The likelihood ratio of a match between the two prints is then Q/R. In the illustrated case, distance I is small and so there is a strong probability of a match. If distance I were great then the value of Q would fall dramatically and the likelihood ratio would fall dramatically as a result. The later approach to the distance measure issue is advantageous as it achieves the result in a single iteration, provides a continuous output and does not require the determination of thresholds.
The databases used to define the two probability distributions preferably reflect the number of minutia being considered in the process. Thus different databases are used where three minutia are being considered, than where twelve minutia are being considered. The manner in which the databases are generated and applied are generally speaking the same, variations in the way the distances are calculated are possible without changing the operation of the database set up and use. Equally, it is possible to form the various databases from a common set of data, but with that data being considered using a different number of minutia to form the database specific to that number of minutia.
The databases may be generated in advance in respect of the numbers of minutia expected to be considered in practice, for instance 3 to 12, with the relevant databases being used for the number of minutia being considered in a particular case, for instance 6. Pre-generation of the databases avoids any delays whilst the databases are generated. However, it is also possible to have to hand the basic data which can be used to generate the databases and generate the database required in a specific case in response to the number of minutia which need to be considered. Thus, a mark may be best considered using six minutia and the desire to consider this mark would lead to the database being generated for six minutia from the basic database of fingerprint representations by considering that using six minutia. The data set size which needs to be stored would be reduced as a result.
In certain circumstances it is also possible to generate the probability distributions in advance. This can occur, for instance, where the within finger variation is being considered and that is considered on the basis of a single (or several) finger(s) not from the suspect. In the case of the model based approach, discussed below, it is possible to generate and store both probability distributions in advance.
Significant benefit from this overall approach arise due to: incorporating distortion and clarity in the numerator of the likelihood ratio; introducing the distance measure between the quantities in the feature vector; the use of probability distribution distances between features vectors from the same source and its estimation from a dedicated sets of data of replicates of the same finger; the use of probability distribution for the distances between print of different sources and its estimation from a reference database containing prints from different sources.
The description presented here exemplifies the use of this methodology, but the methodology is readily adapted for use in other forms. For instance, the Delauney triangulation form could be extended to cover more than three minutiae.
Model Based Approach
Within the general concept of a likelihood ratio approach, another approach which allows the comparison to be expressed in terms of a measure of the strength of the match is through the use of a model based approach.
In such an approach, and after some algebraic operations a probability for the numerator of the likelihood ratio is computed using the following formula,Num=Σ{Pr(fvm,c|fvs,c,fvs,d,fvm,d,Hp): for all fvs,d and fvm,d such that fvs,d=fvm,d}where
fv means feature vector, c means continuous, d means discrete, m means mark and s means suspect. and therefore:
fvm,c: continuous data of the feature vector from the mark
fvm,d: discrete data of the feature vector from the mark
fvs,c: discrete data of the feature vector from the suspect
fvs,d: discrete data of the feature vector from the suspect
d(fvs,c, fvm,c) is the distance measured between the continuous data of the two feature vectors from the mark and the suspect
Hp is the prosecution hypothesis, that is the two feature vectors originate from the same source;
As noted before, the continuous quantities, when conditioning on fvs,c and fvm,c become measurement of the same finger and person. The subscript in the summation symbol means that the probabilities in the right-hand-side of the equation are added up for all the cases where the values of the discrete quantities of the features vectors coincide. In some occasions some or all of the discrete variables are present in the fingermark. For these cases the index of the summation is replaced by values of the quantities that are not present. The summation symbol is removed when all discrete quantities are present in the fingermark.
The probability distribution for fvs,c is computed using a Bayesian network estimated from a database of prints taken from the same finger as described above. Many algorithms exists for estimating the graph and conditional probabilities in a Bayesian networks, but the preferred algorithms are the NPC algorithm for estimating acyclic directed graph, see Steck H., Hofmann, R., and Tresp, V. (1999). Concept for the PRONEL Learning Algorithm, Siemens A G, Munich and/or the EM-algorithm, S. L. Lauritzen (1995). The EM algorithm for graphical association models with missing data. Computational Statistics & Data Analysis, 19:191-201. for estimating the conditional probability distributions. The contents of both documents, particularly in relation to the algorithms they describe are incorporated herein by reference.
Further explanation of the use of Bayesian networks follows below.
The manner in which the first representation is considered against the second representation, through the use of a probability distribution, is as described above, save for the probability distribution being computed using the Bayesian network approach rather than a series of example representations of the second representation.
Using this approach and after some algebraic operations a probability for the denominator of the likelihood ratio is computed using the following formula,Den=Σ{Pr(fvm,c|fvm,d,Hd)Pr(fvm,d|Hd): for all fvs,d and fvm,d such that fvs,d=fvm,d}where
fv means feature vector, c means continuous, d means discrete, m means mark and s means suspect. and therefore:
fvm,c: continuous data of the feature vector from the mark
fvm,d: discrete data of the feature vector from the mark
fvs,c: discrete data of the feature vector from the suspect
fvs,d: discrete data of the feature vector from the suspect
d(fvs,c, fvm,c) is the distance measured between the continuous data of the two feature vectors from the mark and the suspect
Hd is the defence hypothesis, that is the two feature vectors originate from different sources.
The subscript in the summation symbol means that the probabilities in the right-hand-side of equation are added up for all the cases where the values of the discrete quantities of the features vectors coincide. In some occasions some or all of the discrete variables are present in the fingermark. For these cases the index of the summation is replaced by values of the quantities that are not present. The summation symbol is removed when all discrete quantities are present in the fingermark.
The probability distribution in the first factor of the right hand side of equation above is computed with a Bayesian network estimated from a database of feature vectors extracted from different sources. There are many methods for estimating Bayesian networks as noted above, but the preferred methods are the NPC-algorithm of Steck et al., 1999 for estimating an acyclic directed graph and/or the EM-algorithm of Lauritzen, 1995 for the conditional probability distributions. There is a Bayesian network for each combination of values of the discrete variables. The second factor Pr(fvm,d|Hd) is estimated in the same manner as described for the data-driven approach above.
Again the approach to considering the second representation against the population representations is as detailed above, save for the probability distribution being computed using the Bayesian network approach.
Assessing a Comparison Using the Model Based Approach
Given a feature vector from know source fvs and from an unknown source fvm, the numerator is given by the equation and is calculated with a Bayesian network dedicated for modelling distortion. The second factor in the denominator is calculated in the same manner as with the data-driven approach. The first factor is computed using Bayesian networks. A Bayesian network is selected for the combination of values of fm,d which is then use for computing a probability Pr(fvm,c|fvm,d,Hd). This process is repeated for all values in the index of the summation. The likelihood ratio is then obtained by computing the quotient of the numerator over the denominator.
Significant benefit from this approach arise due to: using Bayesian networks for computing the numerators and denominator of the likelihood ratio; estimating Bayesian networks for the numerator from dedicated databases containing replicates of the same finger and under several distortion conditions; estimating Bayesian networks for the denominator from dedicated databases containing prints from different fingers and people.
The description above is an example of using Bayesian networks for calculating the likelihood ratio, but the invention is not limited to it. Another example is estimating one Bayesian network per general pattern. This invention can also be used for more than three minutiae by defining suitable feature vectors.
As mentioned above, in order to estimate the numerator and denominator in the above likelihood ratio consideration, it is possible to use a Bayesian network representation to specify a probability distribution. For brevity of explaination the concept of a Bayesian network is presented through an example. A Bayesian network is an acyclic directed graph together with conditional probabilities associated to the nodes of the graph. Each node in the graph represents a quantity and the arrows represent dependencies between the quantities. FIG. 14 displays an acyclic graph of a Bayesian network representation for the quantities X, Y and Z. This graph contains the information that the joint distribution of X, Y an d Z is given by the equationp(x,y,z)=p(x)p(y|x)p(z|y) for all x,y,z and so the joint distribution is completely specified within the graph and the conditional probability distributions {p(x): for all x}, {p(y/x) for all x and y} and {p(z/y) for all z and y}. A detailed presentation on Bayesian networks can be found in a number of books, such as Cowell, R. G., Dawid A. P., Lauritzen S. L. and Spiegelhalter D. J. (1999) "Probabilistic networks and expert systems".

The Secretary of State for the Home Department


A call-details recording device including: a detecting unit detecting a connection or disconnection of a call; a recording unit recording, when the detecting unit detects the call connection, details of the call by storing the voice data of the call-details in a storage device; and a reproduction enabling unit storing, when the detecting unit detects the call disconnection, the voice data recorded by the recording unit in a reproducible format in an accessible area of the storage device, wherein the detecting unit further detects execution of an interrupting operation of interrupting the conversation, and the reproduction enabling unit stores, when the detecting unit detects the interrupting operation, the voice data recorded by the recording unit to a point of time when executing the interrupting operation from a point of time when connecting the call in the reproducible format in the accessible area.

There have hitherto been a network conference system (refer to Patent document 1) which accumulates conference data about a network conference and regenerates the conference data at a variable speed and also an electronic conference system (refer to Patent document 2) enabling users participating afterward to catch up with a discussion proceeding in real time by providing past messages to these participants in a way that narrows down or compresses time intervals of the past messages and thus reproduces the messages.
Moreover, an AV (Audio Visual) system (refer to Patent document 3) exists, which enables a viewer to retrieve an interrupted position and continuously view the program when moving away from a TV in the middle of viewing the program and returning thereto.
Furthermore, there is an operator support system (refer to Patent document 4) which records a call (conversation) of an operator and attaches a tag associated with details of the call to a record of the call.    [Patent document 1] Japanese Patent Laid-Open Publication No. 2005-244522    [Patent document 2] Japanese Patent Laid-Open Publication No. H11-205314    [Patent document 3] Japanese Patent Laid-Open Publication No. 2006-135532    [Patent document 4] International Publication Pamphlet WO 2004/023772

Call-details recording device and call-details recording method


A semiconductor structure with mixed n-type and p-type non-planar transistors includes a residual overlapping mask bump on one or more of the dummy gates. A dielectric layer is created over the structure having a top surface above the residual bump, for example, using a blanket deposition and chemical-mechanical underpolish (i.e., stopping before exposing the gate cap). The residual bump is then transformed into a same material as the dielectric, either in its entirety and then removing the combined dielectric, or by removing the dielectric first and partly removing the residual bump, the remainder of which is then transformed and the dielectric removed. In either case, the structure is planarized for further processing.

1. Technical Field
The present invention generally relates to non-planar semiconductor device fabrication. More particularly, the present invention relates to reducing or eliminating non-uniform gate height in mixed n-type and p-type non-planar semiconductor device fabrication.
2. Background Information
As semiconductor device size continues to shrink, issues with the fabrication process arise and solutions are explored. For example, raised semiconductor structures (e.g., "fins") allowed size to continue to be reduced versus planar structures. As another example, the use of dummy gates early in the fabrication of FinFETs, replaced later in the process with metal gates, along with the use of epitaxial semiconductor structures on the fins for the active regions, has further allowed for size reduction. However, in practice, when mixed non-planar n-type and p-type devices are co-fabricated on the same substrate, and a replacement metal gate process employed, masks used to protect each type device while operating on the other can sometimes overlap, creating a "bump" at the "boundary" of the masks. The bump can lead to problems with replacing the gate, as well as non-uniform gate height.
Therefore, a need exists for a way to reduce or eliminate non-uniform gate height due to an overlapping mask bump in mixed-type non-planar semiconductor device fabrication.

Uniform gate height for mixed-type non-planar semiconductor devices


An active over-voltage clamp system includes at least one over-voltage detector that is responsive to an input voltage and provides a first current. The system also includes a replica over-voltage circuit that provides a second current, and circuitry subtracting the second current from the first current to produce a difference current. The system further includes a differential clamp activated in response to the difference current. The differential clamp prevents the input voltage from increasing beyond a target voltage.

In wireless data networking, there is a trend toward data converters with higher operating speeds. One design challenge in creating higher speed data converters is to create amplifiers that can rapidly charge, discharge, and amplify signals onto large capacitors. The charging, discharging, and amplifying generally consumes a significant portion of the power in data converters that include such amplifiers.
Parasitic capacitances of the components of amplifiers tend to be a limiting factor in the speed of these amplifiers. Parasitic capacitance effectively puts a limit on the speed of amplifying voltages and getting the voltages to settle accurately. Parasitic capacitance also puts a limit on the clock rates of data converters. Nevertheless, wireless data networking standards continue to look for broadband data and require high sample rates in data converters.
Many designers tend to choose higher voltage amplifiers in order to increase Signal to Noise Ratios (SNRs), since increased SNRs can often facilitate higher speed data processing. Thus, one traditional approach for designing data converters is to simply burn more power in an amplifier by making the amplifier use a higher supply voltage. However, higher voltage transistors (e.g., thick-oxide devices), used to make higher voltage amplifiers, tend to have larger parasitic capacitance than do lower voltage transistors (e.g., thin-oxide devices). The SNR gained from increasing power usage is offset by reduced speed due to increased parasitic capacitance.
Another traditional design approach is to use folded cascode amplifiers. Folded cascode amplifiers provide greater speed and smaller parasitic capacitance than unfolded cascodes, but they also tend to use at least twice as much current. A third traditional approach is to accept the limitations and go with lower-speed data converters.


Methods and systems that facilitate generating and presenting a crossword puzzle. Methods include obtaining, from a content source, a plurality of data items. Using the plurality of data items, a dictionary of clue-word pairs are generated. A crossword layout is generated using a random crossword layout generator. The generated crossword layout is input to a model that outputs a likelihood that the input crossword layout results in a valid crossword. If the likelihood that the crossword layout results in a valid crossword puzzle satisfies a first threshold, a plurality of words in a set of clue-word pairs from among the plurality of clue-word pairs is inserted into the crossword layout. If the plurality of words inserted into the crossword layout results in a valid crossword puzzle, the crossword puzzle is provided to a user on a user device using the set of clue-word pairs.

This specification relates to methods and systems that relates to generating and providing crossword puzzles.
A crossword puzzle is a game in which a user answers a set of clues and fills in these answers (which may be one or more words) into a square or rectangular grid layout generally made up of white and non-white (e.g., black, blue, etc.) boxes.


An electronic display includes a display panel. The display panel includes a pixel array and receives a supply voltage. The display panel also includes a panel driver configured to generate a gate line voltage. The panel driver also supplies the gate line voltage to the display panel based on a comparison between the gate line voltage and the supply voltage.

The present disclosure relates generally to controlling the operating parameters of an electronic device display.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Electronic displays, such as liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays, are commonly used in electronic devices such as televisions, computers, and phones. LCDs portray images by modulating the amount of light that passes through a liquid crystal layer within pixels of varying color. OLED displays portray images by modulating light produced by pixels of varying color. A display driver for LCDs and OLED produces images on the display by adjusting the image signal supplied to each pixel across the display.
Display drivers and panel drivers may be both utilized in conjunction with the electronic displays discussed above to change the image signals supplied to the pixels based on input supplied to the display driver and/or the panel drivers. When the display is powered up, contention between these drivers may occur. This contention may lead to overall reliability issues for the display, the driver circuits, and or the power unit of the display and/or a device housing the display. Accordingly, it may be desirable to reduce any potential power up contentions between a panel driver and display driver of a given display.

Reduction of contention between driver circuitry


This invention relates to a compact and portable detection apparatus for ro-aromatic based chemical compounds, such as nitrotoluenes, dinitrotoluenes, and trinitrotoluene (TNT). The apparatus is based upon the use of fiber optics using filtered light. The preferred process of the invention relies upon a reflective chemical sensor and optical and electronic components to monitor a decrease in fluorescence when the nitro-aromatic molecules in aqueous solution combine and react with a fluorescent polycyclic aromatic compound.

The need for detecting nitro-aromatic based chemical compounds, such as nitrotoluene, dinitrotoluene and trinitrotoluene (TNT), is to avoid spread of contamination in ground water that has leached these chemicals in areas where TNT has been disposed of or inadvertently lost.
U.S. Pat. No. 4,108,604 issued to Hiller on Aug. 22, 1968, discloses in a first embodiment, a method for analyzing water for TNT comprising the steps of allowing water to flow over a resin that contains quaternary ammonium groups and is coated with a flourescent dye, and then observing a change in fluorescence of the fluorescent dye. There is no indication of the level of concentration that can be detected by this method and no apparatus is disclosed.
U.S. Pat. No. 5,157,261 filed May 28, 1991 having some common inventors with the instant invention discloses an apparatus for detecting TNT in air. That patent (U.S. Pat. No. 5,157,261) has a common assignee, the United States Department of Energy. The above mentioned application uses a significantly different sensing device. It has a chemically treated fiber optic distal tip for sensing TNT molecules in air which is drawn into the sensor by a vacuum pump.
The present apparatus provides a simple, portable device that detects TNT in water utilizing a simple method and giving accurate results in the parts-per-billion range in a matter of minutes.

Device for aqueous detection of nitro-aromatic compounds

The United States of America as represented by the Department of Energy


A gas driven apparatus for accelerating particles coated with a genetic material into a target comprises a reservoir for releasably retaining a gas at a sufficiently high pressure to detach the particles from the surface of a sample cartridge and to carry the particles through the apparatus toward the target. When leaving the apparatus, the particles entrained in the gas stream pass through a substantially conical exit nozzle which causes the pattern of distribution of the particles to greatly expand. Methods for using the apparatus and for preparing the sample cartridges are also described.

In the past decade, particle-mediated acceleration of material, particularly genetic material, into living cells and tissues has emerged as an important tool of plant and animal biotechnology. Transient expression and germ line integration of introduced DNA has been demonstrated in microorganisms, plants, and animals.
As the fundamentals of the technology have been worked out, attention has increasingly shifted toward development of devices that offer the operator the ability to perform a series of particle-mediated gene transfers sequentially in rapid succession. Such a device would be particularly advantageous for use in mass immunization of humans or domesticated animals with genetic vaccines.
One limitation of existing particle-mediated gene transfer devices is the form in which the sample is provided. In all such devices, the sample is deposited upon the surface of small, dense particles of a material such as gold or platinum. The coated-particles are themselves then coated onto either a rigid surface, such as a metal plate, or onto a carrier sheet made of a fragile material such as mylar. The coated sheet is then accelerated toward a target. This approach has several advantages as well as some disadvantages. The advantages have to do with the fact that the planar sheet generates a very uniform spread of accelerated particles. One disadvantage is that, each particle-coated plate or carrier sheet is prepared individually and may be used only once, making particle acceleration a time-consuming and inefficient process, particularly when many repetitive gene transfers are envisioned. Each coated carrier sheet is relatively large and must be handled with care, to avoid damage or contamination. It is also sometimes difficult to distinguish the useful coated side of a carrier sheet from the uncoated side. Improper positioning of the carrier sheet can reduce throughput and can result in wasted samples.
The distribution or spread of the pattern of carrier particles may be more critical for some applications, i.e. when germ line events are desired, than for other applications, especially when only transient expression of the introduced genes is needed. When an infrequent germline transformation event is desired, it is necessary to uniformly accelerate particles toward a large area of cells or tissues. To date therefore, it has been considered desirable to distribute the coated-particles as a monolayer on a relatively large surface before accelerating them toward a target to maximize the number of cells receiving particles under precisely uniform conditions, and to thereby increase the likelihood that one cell will undergo a germline transformation. In contrast, when accelerating particles into cells to induce transient gene expression in somatic tissues such as skin, there is a less compelling need to make precisely uniform the acceleration of the particles, since adequate expression can take place even with low numbers of cells actually penetrated by particles. Therefore, particle delivery techniques that to date have been undesirable now become desirable.
To overcome these and other limitations, what is desired is a high throughput gene delivery apparatus that can accept a plurality of samples for rapid and sequential delivery into target tissues. What is also desired is a sample storage and delivery platform that is more durable, and easier to prepare, store, and handle than existing platforms.


A detachable crawler (1, 20) capable of increasing the durability thereof on a rubber belt part (4) body side, wherein each of a metal core (6) and a track shoe (21) of a detachable pad (5) is formed so that tightening force in a specific range (approx. 4.90 to 78.5 MPa per unit area) can be applied to a rubber elastic body (4a) including a tensile reinforcing layer (2) sandwiched between a core bar (3) in the rubber belt part (4) and the metal core (6) or steel track shoe (21) of the detachable paid (5).

Iron crawlers, rubber crawlers and connecting link rubber crawlers have long been used as endless track travel devices for driving construction machines.
A conventional iron crawler is so constructed that steel track shoes are fitted to an endless connecting link pivotally connecting a pair of track links with pins (by welding or a bolt/nut mechanism). In this case, since mechanical connecting force between the track links is large, the iron crawler excels in durability. Besides, when a track shoe is abraded, it is exchangeable. However, the iron crawler has such trouble as a large creaky noise due to the track links, and driver's fatigue due to scanty cushion performance. Besides, if the iron crawler drives on pavements in urban areas, the road surface is damaged.
A conventional rubber crawler is so constructed that metal core bars and steel cords serving as a tensile reinforcing layer are embedded in a rubber elastic body. In this case, there is little noise, cushion performance is good, and the road surface is not damaged. Besides, since the rubber crawler is comparative lightweight, it can drive speedily. However, when the rubber crawler drives on sharp rocks or engineering wastes, cuts sometimes happen in the rubber part. When cuts get to any steel cords of the rubber crawler, the steel cords break due to cutting or corrosion. Therefore, the rubber crawler is unserviceable whether the rubber part is still available or not. Besides, when a tread lug rubber part is abraded by friction with the road surface, the whole rubber crawler must be integrally exchanged.
Recently, there has been a connecting link rubber crawler that makes good use of each merit of the conventional iron crawler and rubber crawler and makes up for each fault thereof. The conventional connecting link rubber crawler is so constructed that rubber pads (divided type or continuous type) are fitted to an endless connecting link pivotally connecting a pair of track links with pins (by welding or a bolt/nut mechanism). Here, a rubber pad is so made that a rubber elastic body is molded and fixed to a metal core. The connecting link rubber crawler has some merit as shown below. That is, since the mechanical connecting force between the track links is large, the connecting link rubber crawler excels in durability. When the tread lug rubber part of the rubber pad is abraded, only the rubber pad need be exchanged. Besides, the road surface is not damaged. However, since the connecting link rubber crawler uses connecting links composed of track links, the noise is large. Accordingly, since night engineering works are increased in urban areas recently, there is still an important noise problem in the connecting link rubber crawler.
Moreover, a detachable rubber crawler is disclosed in Japanese Patent Provisional Publication No. 133876 of 1992. The detachable rubber crawler is provided with tread lug rubber parts to be exchanged when they are abraded or lacking, or when their lug shape is changed in accordance with soil properties. The detachable rubber crawler, as shown in FIG. 19 and FIG. 20, comprises lug rubber parts 22 of one to two or more independent joint articles (which are detachable rubber pads) and a rubber belt part 26. The rubber belt part 26 is arranged on a crawler anti-tread (driving wheel) side with a tensile reinforcing layer 24 and core bars 25 embedded in a rubber elastic body 23. A lug rubber part 22 is provided with a steel metal core 27 and two or more steel pipes 29 each having a hole through which a bolt 28 for fastening the rubber belt part 26 welded to the metal core 27 is passed. A core bar 25 embedded in the rubber belt part 26 is provided with two or more holes with a fixed depth necessary for the steel pipes 29 and holes necessary for the bolts 28 on the same axis therewith. Here, in drawings, 30 is a nut, and 31 is a washer.
In the above-mentioned detachable rubber crawler, when the lug rubber parts are abraded or missing, they can be exchanged. Besides, since the detachable rubber crawler uses not connecting links but rather a rubber belt part, the noise problem can be quieted.
However, as for the rubber belt part, when a large driving force is added to the rubber crawler, a large shear force acts between the core bar and the steel cords, as in the conventional rubber crawler. When the large shear force acts repeatedly, the bonded portion between the core bar and the steel cords gradually causes a fatigue failure. Therefore, since the rubber belt part is damaged over time, the detachable rubber crawler can not completely make good use of the advantage of the exchangeable lug rubber part.


Systems, methods, and computer-readable media provide mechanisms to determine the availability of one or more order items within a supply chain environment. In one embodiment, the method may comprise defining a profile to be associated with an availability check, wherein the availability check consists of a filter process, a sort process, a prepare process, a check process, and an update process, electronically building one or more processing packages for the one or more order items based on the defined profile, and executing the availability check using the profile and one or more processing packages.

I. Field of the Invention
The present invention generally relates to data processing systems and methods. More particularly, the invention relates to computerized systems and methods for automated parallelization of back-order processing in a supply chain environment.
II. Background Information
In a supply chain management (SCM) environment, a planning and optimization module may be used to plan and execute supply chain processes. The confirmation of quantities may be done through an available to promise (ATP) check. Along with a "first come-first served" principle of an ATP check, a user may have the possibility to redistribute confirmed quantities according to priorities and to override the results of the ATP check. The ATP check, also known as an availability check, ensures that a company can provide the requested product at the requested time in the quantity requested by the customer.
Back-order processing (BOP) is typically a function provided within ATP functionality that can check the availability of one or more products using a list of selected orders. By way of example, BOP planning may fulfill a basic request to SCM that consists of changing confirmed quantities. BOP can also be used for redistributing an available quantity of items.
Currently, technological solutions are available to help check if product quantities are available within a supply chain environment. However, existing BOP applications suffer from several drawbacks. For example, one main problem is that frequently high numbers of order lines have to be processed and, as a result, very long processing or run times are observed.
Accordingly, there is a need for improved systems and methods for automatically and more efficiently processing BOP checks, such as BOP checks in a supply chain environment.

Systems and methods for automated parallelization of back-order processing


Damper apparatus for air ports of a chemical recovery furnace is mounted on a removable windbox faceplate. Damper blades extend from a cantilevered arm pivoted at the forward side of the faceplate, with the damper blades being otherwise unsupported, i.e., they are not confined to travel in tracks within the windbox. Rather, a counterweight urges the damper blades against the air port opening whereby the whole mechanism is free for removal as a unit with the faceplate. Cooperatively operable air port cleaning apparatus is also mounted on the faceplate.

The present invention relates to furnaces and particularly to apparatus comprising a removable damper for an air port of a chemical recovery furnace.
Wood pulp for paper making is usually manufactured according to the sulfate process wherein wood chips are treated with a cooking liquor including sodium sulfide and sodium hydroxide. The wood chips and the cooking liquor, called "white liquor", are cooked in a digester under predetermined heat and temperature conditions. After cooking, the used liquor, termed "black liquor", containing spent cooking chemicals and soluble residue from the cook, is washed out of the pulp and treated in a recovery unit where the cooking chemicals are reclaimed. Without reclamation and reuse of the cooking chemicals, the cost of the paper making process would be prohibitive.
In the recovery process, the black liquor is first concentrated by evaporation to a water solution containing about sixty-five percent solids, which solution is then sprayed into the firebox of a black liquor recovery boiler, a type of chemical reduction furnace. The chemical reduction furnace is a reactor wherein the processes of evaporation, gasification, pyrolysis, oxidation and reduction all occur interdependently during recovery of the cooking chemicals. The organic materials in the black liquor, lignin and other wood extracts, maintain combustion in the firebox, and the heat produced melts the spent cooking chemicals. A molten smelt flows out of the furnace through a smelt spout to a collection tank. Concurrently, combustion heat is employed to generate steam in a wall of boiler tubes for use as process steam and for generating electricity.
The combustion process requires the introduction of large volumes of air into the firebox, air comprising about eighty percent of the material entering the furnace. The air is forced into the firebox from windboxes or ducts disposed at several levels in surrounding relation to the firebox, through a plurality of air ports in the walls of the furnace. While variations are possible, the principal air ports are usually primary, secondary and tertiary air ports.
The primary air ports are always the smallest as well as the most numerous and are disposed on the four walls of the firebox near the bottom of the furnace and close to the char bed. The air supplied to the primary air ports is usually at a comparatively low pressure, providing a portion of the air for char bed combustion. This air is used to control the shape and position of the perimeter of the char bed. Secondary air ports, which are generally larger and fewer in number than the primary air ports, are usually disposed around the walls of the firebox higher than the primary air ports and below the level of the liquor spray nozzles. Air supplied through the secondary air ports is at a higher pressure than the primary air and is used to control the position of the top of the char bed as well as promote burning of combustible gasses rising from the char bed. Typically sixty-five to eighty percent of the total combustion air to the recovery boiler is introduced below the level of the liquor spray nozzles. The tertiary air ports are located above the liquor spray nozzles and are generally longer and fewer in number than the secondary air ports. Air supplied through the tertiary air ports is ordinarily at a still higher pressure to promote combustion and final mixing of gasses rising through the firebox.
The black liquor sprayed into the firebox, having a consistency similar to that of warm sixty weight oil, swirls, burns and falls toward the bottom of the firebox as combustion products comprising char material and smelt. The smelt and char material contact the outer walls of the firebox and, cooled by the inflowing air, form excrescent deposits around the edges of the air ports, particularly along the edges of the openings where the excrescent material builds up under influence of air rushing through the air port. Such build-ups of char material can block air flow through the ports and must be removed.
The volume and distribution of combustion air supplied to the furnace is, however, varied depending on many factors including the load of the furnace and properties of the liquor being reduced. The distribution and volume of air entering the furnace are desirably adjusted by regulating means such as dampers provided in supply ducts to the windboxes, at various locations in the windboxes, and at individual air ports for maintaining the desired air supply in all parts of the furnace. Of these three locations, the provision of regulated dampers at the air ports is most deisrable. Providing dampers at individual air ports enables the independent adjustment of mass air flow and air pressure. This independence is key because mass flow is primarily determined by smelt bed conditions, furnace geometry and air-fuel mixing needs and is nearly independent of load. The mass air flow can be controlled by controlling the relative size of the port by adjusting the damper position, while air pressure can be adjusted at a supply fan and by means of dampers within supply ducts. As the damper is closed, the aspect ratio for the air port, which is ordinarily elongated, can be made to approach equal width and height dimensions for more closely simulating a round jet of air. Such a jet is advantageous at the primary air port level as well as at secondary and tertiary air port levels because it is most energy efficient which optimizes combustion control. A more efficient jet also provides better control of the smelt bed and maintains a cleaner windbox inasmuch as cleanliness of the primary windbox is primarily affected by the proximity of the smelt bed and smelt intrusion into the windbox cavity. Maintaining a higher air pressure also helps sweep the bottom of the windbox and pushes the smelt away. Ability to control the air jet from the individual air ports and operating at higher windbox pressures further enables the operator to correct for disturbances in the char bed and otherwise correct the combustion process.
An advantageous damper construction is of the sliding or guillotine type which facilitates the control of the air port aspect ratio in the manner above mentioned whereby a comparatively high pressure jet of air can be produced. Conventional guillotine dampers operate with a pivot point located inside the windbox and slide in a track proximate the air port, the operating mechanism for the damper being contained within the windbox. The air port area is subject to smelt intrusion, thermal expansion, and warping, as well as long periods without use, causing the damper mechanisms to become frozen in a particular position particularly at the primary air port level. Removal or servicing of the damper can be difficult or impossible without closing down the furnace.

Removable damper for chemical recovery furnace


Disclosed is a signal processing circuit which outputs a digital word corresponding to a current source controlled by a physical response. The signal processing circuit includes an analog integrated circuit for generating an analog signal in response to a time varying reference signal and a signal corresponding to the current source controlled by the physical response, a reference signal generator for generating a reference signal, a comparator for comparing the analog signal with the reference signal, an output circuit for generating the digital word indicating a time interval defined by a start signal and an end signal indicating a transition of an output of the comparator, and a controller inactivating the comparator in response to the end signal.

Charge Coupled Device (CCD) imaging arrays have made possible high quality imagers now used in consumer camcorder equipment, scanners for FAX machines, and video cameras for a wide range of applications including video-conferencing, and portable equipment for professional TV broadcasting.
With the advent of multimedia communications, there arises a need for low cost solid state image sensors to complement computers and communication devices and thus realize practical video telephones and the like. An image input device is central to any teleconferencing and multimedia application. Recently, CMOS image sensors have been recognized as a viable candidate for the image input device. CMOS image sensors also have utility in other fields such as robotics, machine vision, security surveillance, automotive applications and personal ID systems through fingerprint/retina scan. A distinct advantage of CMOS image sensors (or imagers) is that signal processing circuits can be readily integrated on the same chip as the image, thus enabling design of smart, single-chip image acquisition systems. CMOS imagers can be manufactured at lower cost than that of conventional charge coupled devices (CCDs) using conventional, preinstalled CMOS fabrication lines without any process modification.
Since portable electronic equipment operates using batteries, it is preferable to design such equipment to provide low-power consumption. The use of a low-power image device enables portable electronic equipment to consume less power.
As is well known, light is analog data that varies continuously. For discrete signal processing, analog data is converted into digital data. CMOS image devices (or imagers) incorporate a device that detects the light as an analog signal and converts a detected analog signal into digital data. For this, CMOS image devices typically incorporate an analog-to-digital converter. In this respect, one approach to realize a low-power image device is to reduce power consumption of analog-to-digital converters incorporated in the image device. Accordingly, there is a need for an analog-to-digital converter capable of reducing power consumption, which can be used for a CMOS image device.

Low-power CMOS image device with analog-to-digital converter circuit


A signal encoding apparatus encodes one-bit signals of a plurality of n channels in a delta-sigma manner. The apparatus includes a phase modulator for phase-modulating the one-bit signals as original signals to add data of inverted phases to the one-bit signals. Information data related to the one-bit signals are added to the phase-modulated one-bit signal by rearranging the data of inverted phases based on a plurality of m channel units of the n channels, where n≧m≧2 and by exclusive ORing the information data and the phase-modulated one-bit signal data.

The data format of high speed one-bit audio signals which are modulated in the ΔΣ manner has an extremely high sampling frequency of 64 times 44.1 kHz and a short data word length of one bit, as compared with that of the conventional digital audio signals which has a sampling frequency of 44.1 kHz and a data word length of 16 bits. Thus, by employing the high speed one-bit audio signals, a broad transmittable frequency band can be obtained. Even though the data word of the high speed one-bit audio signals modulated in the ΔΣ manner is one-bit, by employing the signals, a high dynamic range can be secured in the audio band which is low against the over sampling frequency of 64 times the sampling frequency. These characteristics can be applied to data recording and data transmission maintaining high tone quality.
The ΔΣ modulation itself is not a new technique, and conventionally the ΔΣ modulating circuit is often used in an A/D converter, since the circuit can suitably be configured in the form of an IC, and A/D conversion with high accuracy can be performed without difficulty.
The ΔΣ-modulated signals or signals which are modulated in the ΔΣ manner can be restored to original analog signals by causing the ΔΣ-modulated signals to pass through an analog low-pass filter of simple configuration.
In transmitting the one-bit ΔΣ-modulated audio signals, there arise radiation noises due to a transmission line or a transmission circuit, and the generated radiation noises break into an analog audio unit and has a bad effect thereon. In order to solve the problem, the applicant of the present invention proposed a phase modulating method in "Signal Transmitting Apparatus and Method" disclosed in Japanese Laying-Open Patent H-9-186728, in which transmission signals and signals of inverted phases or signals whose phases are opposite to those of the transmission signals are alternately transmitted at a double transmission rate. In employing the phase modulating method, analog audio signals which are sufficiently low against the transmission rate are canceled by those of inverted phases, and the analog audio signals are sufficiently suppressed to low level.
When transmitting the one-bit ΔΣ-modulated audio signals, a transmitting method is desired which can transmit music signals as original signals as well as information data such as data character.
When transmitting the music signals and information data added thereto, the transmission rate is desired to be integer multiple of that of the music signals due to the facility of the processing. Thus, data to be transmitted becomes at least double in amount, and finally a quadruple transmission rate is undesirably required since signals of inverted phases are added thereto.

Digital signal encoding apparatus and method, digital signal decoding apparatus and method, and digital signal transmission system


The invention provides new processes for preparing polyglutamic acid-therapeutic agent conjugates for clinical development and pharmaceutical use, and polyglutamic acid-therapeutic agent conjugates prepared by these processes.

The antitumor agent paclitaxel shows increased efficacy and decreased toxicity when administered to tumor-bearing hosts as a polyglutamic acid conjugate compared with the unconjugated form of the drug (U.S. Pat. No. 5,977,163; Li et al., Cancer Res., 58:2404, 1998). The polyglutamic acid-paclitaxel conjugate shows increased water solubility, a slower clearance from the body, and an increased accumulation in the tumor. Conjugates of polyglutamic acid and various other therapeutic agents are expected to provide clinically useful alternatives to the presently available formulations.
For research purposes, the polyglutamic acid-therapeutic agent conjugates can be produced by the method disclosed in Li et al., ibid. In that method, the conjugate is prepared as a sodium salt, dialyzed to remove low molecular weight contaminants and excess salt and then lyophilized. The method is not well-suited for large-scale manufacture of quantities of conjugates for clinical development and use, however. In particular, the use of dialysis to remove impurities is time-consuming and lowers final product yield. In addition, although many pharmaceuticals have more favorable properties when prepared as salts (e.g., improved solubility, storage, and handling), this is not true of the polyglutamate-therapeutic agent conjugates of the present invention. The salt forms of the conjugates are electrostatic solids, not free flowing powders. They are more difficult to package, more susceptible to dust contamination and more likely to contaminate the workplace with cytotoxic agents than are free flowing powders. Therefore, there is a need for an improved process of manufacture of polyglutamic acid-therapeutic agent conjugates that can be used to produce gram to hundreds of gram quantities of these conjugates in high yields and in a manner that provides for improved materials handling and packaging.

Manufacture of polyglutamate-therapeutic agent conjugates