The fossil record is the only source of information on the long-term dynamics of species assembla... more The fossil record is the only source of information on the long-term dynamics of species assemblages. Here we assess the degree of ecological stability of the epifaunal pterioid bivalve assemblage (EPBA), which is part of the Middle Devonian Hamilton fauna of New York—the type example of the pattern of coordinated stasis, in which long intervals of faunal persistence are terminated by turnover events induced by environmental change. Previous studies have used changes in abundance structure within specific biofacies as evidence for a lack of ecological stability of the Hamilton fauna. By comparing data on relative abundance, body size, and predation, indexed as the frequency of unsuccessful shell-crushing attacks, of the EPBA, we show that abundance structure varied through time, but body-size structure and predation pressure remained relatively stable. We suggest that the energetic set-up of the Hamilton fauna's food web was able to accommodate changes in species attributes, such as fluctuating prey abundances. Ecological redundancy in prey resources, adaptive foraging of shell-crushing predators (arising from predator behavioral or adaptive switching in prey selection in response to changing prey abundances), and allometric scaling of predator-prey interactions are discussed as potential stabilizing factors contributing to the persistence of the Hamilton fauna's EPBA. Our study underscores the value and importance of multiple lines of evidence in tests of ecological stability in the fossil record.
An optimal filter is estimated to restore binary fax images. The filter is an approximation of th... more An optimal filter is estimated to restore binary fax images. The filter is an approximation of the binary conditional expectation which minimizes the expected absolute error between the degraded image and the ideal image. It is implemented as a morphological hit-or-miss filter. Estimation methodology employs a model-based simulation of the degradation due to the fax process.
The exact probability density for a windowed observation of a discrete 1D Boolean process having ... more The exact probability density for a windowed observation of a discrete 1D Boolean process having convex grains is found via recursive probability expressions. This observation density is used as the likelihood function for the process and numerically yields the maximum- likelihood estimator for the process intensity and the parameters governing the distribution of the grain lengths. Maximum-likelihood estimation is applied in the case of Poisson distributed lengths.
A one-dimensional discrete Boolean model is a random process on the discrete line where random-le... more A one-dimensional discrete Boolean model is a random process on the discrete line where random-length line segments are positioned according to the outcomes of a Bernoulli process. Points on the discrete line are either covered or left uncovered by a realization of the process. An observation of the process consists of runs of covered and not-covered points, called black and white runlengths, respectively. The black and white runlengths form an alternating sequence of independent random variables. We show how the Boolean model is completely determined by probability distributions of these random variables by giving explicit formulas linking the marking probability of the Bernoulli process and segment length distribution with the runlength distributions. The black runlength density is expressed recursively in terms of the marking probability and segment length distribution and white runlengths are shown to have a geometric probability law. Filtering for the Boolean model can also be done via runlengths. The optimal minimum mean absolute error filter for union noise is computed as the binary conditional expectation for windowed observations, expressible as a function observed black runlengths.
Parametric estimation is achieved for the discrete 2D Boolean model by applying maximum- likeliho... more Parametric estimation is achieved for the discrete 2D Boolean model by applying maximum- likelihood estimation on linear samples. Under certain conditions, a 2D Boolean model induces a 1D Boolean model so that the likelihood function of a 1D observation is expressed in terms of the parameters of the 2D inducing model, thereby enabling maximum-likelihood estimation to be performed on the 2D model using linear samples.
Gray-scale textures can be viewed as random surfaces in gray-scale space. One method of construct... more Gray-scale textures can be viewed as random surfaces in gray-scale space. One method of constructing such surfaces is the Boolean random function model wherein a surface is formed by taking the maximum of shifted random functions. This model is a generalization of the Boolean random set model in which a binary image is formed by the union of randomly positioned shapes. The Boolean random set model is composed of two independent random processes: a random shape process and a point process governing the placement of grains. The union of the randomly shifted grains forms a binary texture of overlapping objects. For the Boolean random function model, the random set or grain is replaced by a random function taking values among the admissible gray values. The maximum over all the randomly shifted functions produces a model of a rough surface that is appropriate for some classes of textures. The Boolean random function model is analyzed by viewing its behavior on intersecting lines. Under mild conditions in the discrete setting, 1D Boolean random set models are induced on intersecting lines. The discrete 1D model has been completely characterized in previous work. This analysis is used to derive a maximum- likelihood estimation for the Boolean random function.
The Boolean model is a random set process in which random shapes are positioned according to the ... more The Boolean model is a random set process in which random shapes are positioned according to the outcomes of an independent point process. In the discrete case, the point process is Bernoulli. To do estimation on the two-dimensional discrete Boolean model, we sample the germ-grain model at widely spaced points. An observation using this procedure consists of jointly distributed horizontal and vertical runlengths. An approximate likelihood of each cross observation is computed. Since the observations are taken at widely spaced points, they are considered independent and are multiplied to form a likelihood function for the entire sampled process. Estimation for the two-dimensional process is done by maximizing the grand likelihood over the parameter space. Simulations on random-rectangle Boolean models show significant decrease in variance over the method using horizontal and vertical linear samples. Maximum-likelihood estimation can also be used to fit models to real textures.
The Boolean random set model is a tractable random set model used in image analysis, geostatistic... more The Boolean random set model is a tractable random set model used in image analysis, geostatistics, and queueing systems, among others. It can be formulated in the continuous and discrete settings, each of which offers certain advantages with regard to modeling and estimation. The continuous model enjoys more elegant theory but often results in intractable formulas. The discrete model, especially in the 1D directional case, provides flexible models, tractable estimators, and optimal filters.
Region-based coding is applied to images composed of disjoint texture regions, where in each regi... more Region-based coding is applied to images composed of disjoint texture regions, where in each region the image is generated by a discrete random Boolean model. The image is segmented into regions by applying pixelwise granulometric classification and the region boundaries are chain encoded. Maximum-likelihood estimation based upon induced 1D Boolean models is used to estimate the parameters of the governing processes in each region. The regions are coded by these parameters. Decoding is accomplished by generating in each region a realization of the appropriate random set.
Journal of The American Society for Information Science and Technology, 1991
Three meanings of information are distinguished: Information-as-process; information-as-know... more Three meanings of information are distinguished: Information-as-process; information-as-knowledge; and information-as-thing, the attributive use of in-formation to denote things regarded as informative. The nature and characteristics of information-as- ...
Image evaluation tasks are often conducted using paired comparisons or ranking. To elicit interva... more Image evaluation tasks are often conducted using paired comparisons or ranking. To elicit interval scales, both methods rely on Thurstone's Law of Comparative Judgment in which objects closer in psychological space are more often confused in preference comparisons by a putative discriminal random process. It is often debated whether paired comparisons and ranking yield the same interval scales. An experiment was conducted to assess scale production using paired comparisons and ranking. For this experiment a Pioneer Plasma Display and Apple Cinema Display were used for stimulus presentation. Observers performed rank order and paired comparisons tasks on both displays. For each of five scenes, six images were created by manipulating attributes such as lightness, chroma, and hue using six different settings. The intention was to simulate the variability from a set of digital cameras or scanners. Nineteen subjects, (5 females, 14 males) ranging from 19-51 years of age participated in this experiment. Using a paired comparison model and a ranking model, scales were estimated for each display and image combination yielding ten scale pairs, ostensibly measuring the same psychological scale. The Bradley-Terry model was used for the paired comparisons data and the Bradley-Terry-Mallows model was used for the ranking data. Each model was fit using maximum likelihood estimation and assessed using likelihood ratio tests. Approximate 95% confidence intervals were also constructed using likelihood ratios. Model fits for paired comparisons were satisfactory for all scales except those from two image/display pairs; the ranking model fit uniformly well on all data sets. Arguing from overlapping confidence intervals, we conclude that paired comparisons and ranking produce no conflicting decisions regarding ultimate ordering of treatment preferences, but paired comparisons yield greater precision at the expense of lack-of-fit.
Recursive decomposition of fundamental events in the directional, one-dimensional, discrete, stat... more Recursive decomposition of fundamental events in the directional, one-dimensional, discrete, stationary Boolean model has resulted in analytic representation of the event probabilities and the recursive representation of clump-length and gap-length densities. This paper applies the methodology to find analytic expressions for distributions of a number of random variables, including the number of grains covering a point. It extends the methodology, including clump- and gap-length analysis, to more general coverage processes where marking probabilities and grain-length distributions are point-dependent, and to the case where there can be multiple grains commencing at a marked point.Die rekursive Zerlegung von Fundamentalereignissen im gerichteten, eindimensionalen, diskreten, stationären Booleschen Model ergab eine analytische Darstellung der Dichten der Klumpenängen und der Lückenlängen. Die vorliegende Arbeit wendet diese Methodologie an, um analytische Ausdrücke für die Verteilungen einer Anzahl von Zufallsvariablen zu finden, darunter die Anzahl der körner, die einen Punkt bedecken. Sie erweitert die Methodologie unter Einbeziehung der Analyse der Klumpen- und Lückenlängen auf allgemeinere Überdeckungsprozesse, bei denen die Markierungswahrscheinlichkeiten und die Konlängenverteilungen punktabhängig sind, und auf den Fall, bei dem mehrere Körner an einem markierten Punkt beginnen können.La décomposition récursive d'évènements fondamentaux dans le modèle booléen stationnaire, discret, mono-dimensionnel, et directionnel a fourni la représentation analytique des probabilités d'évènements et la représentation récursive des densités de longueurs de groupes et d'intervalles. Nous appliquons dans cet article cette méthodologie à la recherche d'expressions analytiques pour les distributions d'un certain nombre de variables aléatoires, telles que le nombre de grains couvrant un point. Ceci constitue une extension de la méthodologie, incluant l'analyse des longueurs de groupes et d'intervalles, à des processus de recouvrement plus généraux dans lesquels les probabilités de marquage et les distributions de longueur de grain sont dépendantes du point, et au cas où il peut y avoir des grains multiples commençant à un point marqué.
We present a document understanding system in which the arrangement of lines of text and block se... more We present a document understanding system in which the arrangement of lines of text and block separators within a document are modeled by stochastic context free grammars. A grammar corresponds to a document genre; our system may be adapted to a new genre simply by replacing the input grammar. The system incorporates an optical character recognition system that outputs characters, their positions and font sizes. These features are combined to form a document representation of lines of text and separators. Lines of text are labeled as tokens using regular expression matching. The maximum likelihood parse of this stream of tokens and separators yields a functional labeling of the document lines. We describe business card and business letter applications.
... Eamonn Keogh University of California - Riverside, USA ... BACKGROUND The use of data compres... more ... Eamonn Keogh University of California - Riverside, USA ... BACKGROUND The use of data compression to classify sequences is also closely related to the Minimum Description Length (MDL) and Minimum Message Length (MML) prin-ciples (Grünwald, 2007), (Wallace, 2005). ...
For three years, Project ADAPT has investigated methods that must be developed to support economi... more For three years, Project ADAPT has investigated methods that must be developed to support economical conversion of information into electronic information systems-not just symbol recognition but document recognition. ADAPT system software provides a prototype methodology for hands-off conversion of document images to a tagged, structured document database. ADAPT also includes pilot efforts to increase optical character recognition (OCR) accuracy and to increase automated structure analysis capabilities of systems-document format recognition. Digitization of high-quality microfilm material may be the most practical way to load many documents into a conversion system, considering materials handling problems.
The fossil record is the only source of information on the long-term dynamics of species assembla... more The fossil record is the only source of information on the long-term dynamics of species assemblages. Here we assess the degree of ecological stability of the epifaunal pterioid bivalve assemblage (EPBA), which is part of the Middle Devonian Hamilton fauna of New York—the type example of the pattern of coordinated stasis, in which long intervals of faunal persistence are terminated by turnover events induced by environmental change. Previous studies have used changes in abundance structure within specific biofacies as evidence for a lack of ecological stability of the Hamilton fauna. By comparing data on relative abundance, body size, and predation, indexed as the frequency of unsuccessful shell-crushing attacks, of the EPBA, we show that abundance structure varied through time, but body-size structure and predation pressure remained relatively stable. We suggest that the energetic set-up of the Hamilton fauna's food web was able to accommodate changes in species attributes, such as fluctuating prey abundances. Ecological redundancy in prey resources, adaptive foraging of shell-crushing predators (arising from predator behavioral or adaptive switching in prey selection in response to changing prey abundances), and allometric scaling of predator-prey interactions are discussed as potential stabilizing factors contributing to the persistence of the Hamilton fauna's EPBA. Our study underscores the value and importance of multiple lines of evidence in tests of ecological stability in the fossil record.
An optimal filter is estimated to restore binary fax images. The filter is an approximation of th... more An optimal filter is estimated to restore binary fax images. The filter is an approximation of the binary conditional expectation which minimizes the expected absolute error between the degraded image and the ideal image. It is implemented as a morphological hit-or-miss filter. Estimation methodology employs a model-based simulation of the degradation due to the fax process.
The exact probability density for a windowed observation of a discrete 1D Boolean process having ... more The exact probability density for a windowed observation of a discrete 1D Boolean process having convex grains is found via recursive probability expressions. This observation density is used as the likelihood function for the process and numerically yields the maximum- likelihood estimator for the process intensity and the parameters governing the distribution of the grain lengths. Maximum-likelihood estimation is applied in the case of Poisson distributed lengths.
A one-dimensional discrete Boolean model is a random process on the discrete line where random-le... more A one-dimensional discrete Boolean model is a random process on the discrete line where random-length line segments are positioned according to the outcomes of a Bernoulli process. Points on the discrete line are either covered or left uncovered by a realization of the process. An observation of the process consists of runs of covered and not-covered points, called black and white runlengths, respectively. The black and white runlengths form an alternating sequence of independent random variables. We show how the Boolean model is completely determined by probability distributions of these random variables by giving explicit formulas linking the marking probability of the Bernoulli process and segment length distribution with the runlength distributions. The black runlength density is expressed recursively in terms of the marking probability and segment length distribution and white runlengths are shown to have a geometric probability law. Filtering for the Boolean model can also be done via runlengths. The optimal minimum mean absolute error filter for union noise is computed as the binary conditional expectation for windowed observations, expressible as a function observed black runlengths.
Parametric estimation is achieved for the discrete 2D Boolean model by applying maximum- likeliho... more Parametric estimation is achieved for the discrete 2D Boolean model by applying maximum- likelihood estimation on linear samples. Under certain conditions, a 2D Boolean model induces a 1D Boolean model so that the likelihood function of a 1D observation is expressed in terms of the parameters of the 2D inducing model, thereby enabling maximum-likelihood estimation to be performed on the 2D model using linear samples.
Gray-scale textures can be viewed as random surfaces in gray-scale space. One method of construct... more Gray-scale textures can be viewed as random surfaces in gray-scale space. One method of constructing such surfaces is the Boolean random function model wherein a surface is formed by taking the maximum of shifted random functions. This model is a generalization of the Boolean random set model in which a binary image is formed by the union of randomly positioned shapes. The Boolean random set model is composed of two independent random processes: a random shape process and a point process governing the placement of grains. The union of the randomly shifted grains forms a binary texture of overlapping objects. For the Boolean random function model, the random set or grain is replaced by a random function taking values among the admissible gray values. The maximum over all the randomly shifted functions produces a model of a rough surface that is appropriate for some classes of textures. The Boolean random function model is analyzed by viewing its behavior on intersecting lines. Under mild conditions in the discrete setting, 1D Boolean random set models are induced on intersecting lines. The discrete 1D model has been completely characterized in previous work. This analysis is used to derive a maximum- likelihood estimation for the Boolean random function.
The Boolean model is a random set process in which random shapes are positioned according to the ... more The Boolean model is a random set process in which random shapes are positioned according to the outcomes of an independent point process. In the discrete case, the point process is Bernoulli. To do estimation on the two-dimensional discrete Boolean model, we sample the germ-grain model at widely spaced points. An observation using this procedure consists of jointly distributed horizontal and vertical runlengths. An approximate likelihood of each cross observation is computed. Since the observations are taken at widely spaced points, they are considered independent and are multiplied to form a likelihood function for the entire sampled process. Estimation for the two-dimensional process is done by maximizing the grand likelihood over the parameter space. Simulations on random-rectangle Boolean models show significant decrease in variance over the method using horizontal and vertical linear samples. Maximum-likelihood estimation can also be used to fit models to real textures.
The Boolean random set model is a tractable random set model used in image analysis, geostatistic... more The Boolean random set model is a tractable random set model used in image analysis, geostatistics, and queueing systems, among others. It can be formulated in the continuous and discrete settings, each of which offers certain advantages with regard to modeling and estimation. The continuous model enjoys more elegant theory but often results in intractable formulas. The discrete model, especially in the 1D directional case, provides flexible models, tractable estimators, and optimal filters.
Region-based coding is applied to images composed of disjoint texture regions, where in each regi... more Region-based coding is applied to images composed of disjoint texture regions, where in each region the image is generated by a discrete random Boolean model. The image is segmented into regions by applying pixelwise granulometric classification and the region boundaries are chain encoded. Maximum-likelihood estimation based upon induced 1D Boolean models is used to estimate the parameters of the governing processes in each region. The regions are coded by these parameters. Decoding is accomplished by generating in each region a realization of the appropriate random set.
Journal of The American Society for Information Science and Technology, 1991
Three meanings of information are distinguished: Information-as-process; information-as-know... more Three meanings of information are distinguished: Information-as-process; information-as-knowledge; and information-as-thing, the attributive use of in-formation to denote things regarded as informative. The nature and characteristics of information-as- ...
Image evaluation tasks are often conducted using paired comparisons or ranking. To elicit interva... more Image evaluation tasks are often conducted using paired comparisons or ranking. To elicit interval scales, both methods rely on Thurstone's Law of Comparative Judgment in which objects closer in psychological space are more often confused in preference comparisons by a putative discriminal random process. It is often debated whether paired comparisons and ranking yield the same interval scales. An experiment was conducted to assess scale production using paired comparisons and ranking. For this experiment a Pioneer Plasma Display and Apple Cinema Display were used for stimulus presentation. Observers performed rank order and paired comparisons tasks on both displays. For each of five scenes, six images were created by manipulating attributes such as lightness, chroma, and hue using six different settings. The intention was to simulate the variability from a set of digital cameras or scanners. Nineteen subjects, (5 females, 14 males) ranging from 19-51 years of age participated in this experiment. Using a paired comparison model and a ranking model, scales were estimated for each display and image combination yielding ten scale pairs, ostensibly measuring the same psychological scale. The Bradley-Terry model was used for the paired comparisons data and the Bradley-Terry-Mallows model was used for the ranking data. Each model was fit using maximum likelihood estimation and assessed using likelihood ratio tests. Approximate 95% confidence intervals were also constructed using likelihood ratios. Model fits for paired comparisons were satisfactory for all scales except those from two image/display pairs; the ranking model fit uniformly well on all data sets. Arguing from overlapping confidence intervals, we conclude that paired comparisons and ranking produce no conflicting decisions regarding ultimate ordering of treatment preferences, but paired comparisons yield greater precision at the expense of lack-of-fit.
Recursive decomposition of fundamental events in the directional, one-dimensional, discrete, stat... more Recursive decomposition of fundamental events in the directional, one-dimensional, discrete, stationary Boolean model has resulted in analytic representation of the event probabilities and the recursive representation of clump-length and gap-length densities. This paper applies the methodology to find analytic expressions for distributions of a number of random variables, including the number of grains covering a point. It extends the methodology, including clump- and gap-length analysis, to more general coverage processes where marking probabilities and grain-length distributions are point-dependent, and to the case where there can be multiple grains commencing at a marked point.Die rekursive Zerlegung von Fundamentalereignissen im gerichteten, eindimensionalen, diskreten, stationären Booleschen Model ergab eine analytische Darstellung der Dichten der Klumpenängen und der Lückenlängen. Die vorliegende Arbeit wendet diese Methodologie an, um analytische Ausdrücke für die Verteilungen einer Anzahl von Zufallsvariablen zu finden, darunter die Anzahl der körner, die einen Punkt bedecken. Sie erweitert die Methodologie unter Einbeziehung der Analyse der Klumpen- und Lückenlängen auf allgemeinere Überdeckungsprozesse, bei denen die Markierungswahrscheinlichkeiten und die Konlängenverteilungen punktabhängig sind, und auf den Fall, bei dem mehrere Körner an einem markierten Punkt beginnen können.La décomposition récursive d'évènements fondamentaux dans le modèle booléen stationnaire, discret, mono-dimensionnel, et directionnel a fourni la représentation analytique des probabilités d'évènements et la représentation récursive des densités de longueurs de groupes et d'intervalles. Nous appliquons dans cet article cette méthodologie à la recherche d'expressions analytiques pour les distributions d'un certain nombre de variables aléatoires, telles que le nombre de grains couvrant un point. Ceci constitue une extension de la méthodologie, incluant l'analyse des longueurs de groupes et d'intervalles, à des processus de recouvrement plus généraux dans lesquels les probabilités de marquage et les distributions de longueur de grain sont dépendantes du point, et au cas où il peut y avoir des grains multiples commençant à un point marqué.
We present a document understanding system in which the arrangement of lines of text and block se... more We present a document understanding system in which the arrangement of lines of text and block separators within a document are modeled by stochastic context free grammars. A grammar corresponds to a document genre; our system may be adapted to a new genre simply by replacing the input grammar. The system incorporates an optical character recognition system that outputs characters, their positions and font sizes. These features are combined to form a document representation of lines of text and separators. Lines of text are labeled as tokens using regular expression matching. The maximum likelihood parse of this stream of tokens and separators yields a functional labeling of the document lines. We describe business card and business letter applications.
... Eamonn Keogh University of California - Riverside, USA ... BACKGROUND The use of data compres... more ... Eamonn Keogh University of California - Riverside, USA ... BACKGROUND The use of data compression to classify sequences is also closely related to the Minimum Description Length (MDL) and Minimum Message Length (MML) prin-ciples (Grünwald, 2007), (Wallace, 2005). ...
For three years, Project ADAPT has investigated methods that must be developed to support economi... more For three years, Project ADAPT has investigated methods that must be developed to support economical conversion of information into electronic information systems-not just symbol recognition but document recognition. ADAPT system software provides a prototype methodology for hands-off conversion of document images to a tagged, structured document database. ADAPT also includes pilot efforts to increase optical character recognition (OCR) accuracy and to increase automated structure analysis capabilities of systems-document format recognition. Digitization of high-quality microfilm material may be the most practical way to load many documents into a conversion system, considering materials handling problems.
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Papers by John Handley