Michael A Covington

• University of Georgia

Straightforward linguistic measures may be indicators of reduced language production and lexical diversity among individuals with schizophrenia with negative symptoms and neurocognitive impairments. We compared 98 patients with schizophrenia to 101 unaffected controls on six language variables (e.g., number of relationships between objects, use of...

Automated tools do not yet exist to measure formal thought disorder, including derailment and tangentiality, both of which can be subjectively rated using the Scale for the Assessment of Positive Symptoms after a clinical research interview. CoVec, a new automated tool, measures the semantic similarity among words averaged in a five- and ten-word w...

Background Acoustic phonetics methods are useful in examining some symptoms of schizophrenia; we used such methods to understand the underpinnings of aprosody. We hypothesized that compared to controls and patients without clinically rated aprosody, patients with aprosody would exhibit reduced variability in: pitch, jaw/mouth opening and tongue hei...

Objective: Acoustic phonetic methods are useful in examining some symptoms of schizophrenia; we used such methods to understand the underpinnings of aprosody. We hypothesized that, compared to controls and patients without clinically rated aprosody, patients with aprosody would exhibit reduced variability in: pitch (F0), jaw/mouth opening and tong...

Although rating scales to assess formal thought disorder exist, there are no objective, high-reliability instruments that can quantify and track it. This proof-of-concept study shows that CoVec, a new automated tool, is able to differentiate between controls and patients with schizophrenia with derailment and tangentiality. According to ratings fro...

The asterism of Veronica’s Veil reported by Rheita in 1645 is argued to be real, though inconspicuous; not a star cluster; and not correlated with Johannes Zahn’s picture published in 1686 and widely redistributed. The asterism is most likely the rectangle bounded by ρ Leonis, β Sextantis, ο Leonis, and ι Hydrae, with some scattered interior stars...

Background: The negative symptoms of schizophrenia are very impairing to patients’ lives and functioning and are a focus of considerable empirical and clinical attention. Computerized acoustic analysis of patients’ speech is a sophisticated and promising approach for measuring two cardinal negative symptoms of schizophrenia: blunted affect, and alo...

This is the first cross-language study of the effect of schizophrenia on speech as measured by analyzing phonetic parameters with sound spectrography. We hypothesized that reduced variability in pitch and formants would be correlated with negative symptom severity in two samples of patients with schizophrenia, one from Italy, and one from the Unite...

Quantitative stylometry of ten translations of the same Bible passage into English, followed by Ward clustering, produces a dendrogram that reflects the well-known history and intent of the translations. We conclude that quantitative stylometry combined with clustering is a useful tool for reconstructing literary history.

Speech deficits, notably those involved in psychomotor retardation, blunted affect, alogia and poverty of content of speech, are pronounced in a wide range of serious mental illnesses (e.g., schizophrenia, unipolar depression, bipolar disorders). The present project evaluated the degree to which these deficits manifest as a function of cognitive re...

Socio-Cultural Analysis (SCA) has evolved rapidly over the past decade as conflicts in Afghanistan and Iraq have forced the DOD to reappraise the techniques used to collect information about the populations in conflict zones. As these two major conflicts wind down, the DOD must recognize that SCA must evolve again due the changing responsibilities...

Web pages generally contain a large amount of information that is not part of their main content, such as navigation panels, copyright and privacy notices, and advertisements. Such irrelevant information, known as Web page noise, can seriously affect the accuracy of search and other web mining applications; the act of remov-ing it is called "cleani...

Background: Aprosody, or flattened speech intonation, is a recognized negative symptom of schizophrenia, though it has rarely been studied from a linguistic/phonological perspective. To bring the latest advances in computational linguistics to the phenomenology of schizophrenia and related psychotic disorders, a clinical first-episode psychosis re...

Coding standards and good practices are fundamental to a disciplined approach to software projects irrespective of programing languages being employed. Prolog programing can benefit from such an approach, perhaps more than programing in other languages. Despite this, no widely accepted standards and practices seem to have emerged till now. The pres...

The Architecture Represented Computationally (ARC) project analyzes documents that describe Gothic cathedrals. It researches how these descriptions can be translated from a natural language into a formal logical model - a representation that a computer can handle. Handling representations of architecture is not straightforward and requires expertis...

This paper introduces a work in progress on a new research topic for artificial intelligence. It presents the first stages of research that investigates the capacities of AI to understand the architectural rules that define historic architecture: specifically those of Gothic cathedrals. Gothic architecture has its own logic. It follows rules that a...

The ARC project (for Architecture Represented Computationally) is an attempt to reproduce in computer form the architectural historian's mental model of the Gothic cathedral. This model includes the background information necessary to understand a natural language architectural description. Our first task is to formalize the description of Gothic c...

Unconventional discourse in schizophrenia has been speculated to be attributable to the mixing up of symbols and signs. We illustrate how a series of scientific images, cartoons, and prose are used by a patient to weave disparate-and objectively unrelated-concepts. The resulting prose is incoherent science.

Home-raised African Grey parrots (Psittacus erithacus erithacus) exhibit strong social bonding with their human companions. We examined how 1 parrot's vocal production (speech and nonword sounds) changed with social context with respect to descriptive measures of the vocalizations and their thematic content. We videotaped the parrot in 4 social con...

Type–token ratio (TTR), or vocabulary size divided by text length (V/N), is a time-honoured but unsatisfactory measure of lexical diversity. The problem is that the TTR of a text sample is affected by its length. We present an algorithm for rapidly computing TTR through a moving window that is independent of text length, and we demonstrate that thi...

Coding standards and good practices are fundamental to a disciplined approach to software projects, whatever programming languages they employ. Prolog programming can benefit from such an approach, perhaps more than programming in other languages. Despite this, no widely accepted standards and practices seem to have emerged up to now. The present p...

Idea density, or number of propositions divided by number of words, is a well-known psycholinguistic measurement which can now be estimated reliably by software. Preliminary tests indicate that idea density distinguishes between documents about the same subject written for specialist and nonspecialist audiences, and that it does not correlate with...

In this chapter, we have presented our SA wheelchair prototype which consists of a stationary ranging module, a motorized vision module, and a tactile feedback module. The goal of our SA wheelchair project is to provide perceptual and navigational capabilities to wheelchairbound users with severe vision impairment. Our SA wheelchair is particularly...

The Computerized Propositional Idea Density Rater (CPIDR, pronounced "spider") is a computer program that determines the propositional idea density (P-density) of an English text automatically on the basis of part-of-speech tags. The key idea is that propositions correspond roughly to verbs, adjectives, adverbs, prepositions, and conjunctions. Afte...

This paper presents the design of a novel tactile display, the Vibrotactile Glove, which provides a wheelchair user who has severe visual impairment with vibration (vibrotactile) signals to operate a powered wheelchair. The vibrotactile signals are conducted to the user's skin through a 3-by-3 array of vibrating elements (also known as vibrotactor)...

As the BS in Computer Systems Engineering degree is being implemented at UGA, we are evaluating the use of Body Sensor Networks developed at The Imperial College London as a laboratory platform for the experimentation components in Bio-Instrumentation, Embedded Systems and Wireless Sensor Networks courses. The system will be evaluated for computati...

Speech disturbances are well-known symptoms contributing to the diagnosis of schizophrenia. Subanesthetic doses of the N-methyl-D-aspartate (NMDA) antagonist ketamine have been reported to produce positive and negative symptoms and cognitive impairments consistent with those seen in schizophrenia. Insofar as this is true, it constitutes evidence th...

Part I. Basics: 1. The DSLR revolution; 2. Main technical issues; 3. Basic camera operation; 4. Four simple projects; 5. Coupling cameras to telescopes; Part II. Cameras, Lenses, and Telescopes: 6. More about focal reducers; 7. Lenses for piggybacking; 8. Focusing; 9. Tracking the stars; 10. Power and camera control in the field; 11. Sensors and se...

Few astronomical topics are as confusing as star names. How did we get ourselves into this mess?

Patients with schizophrenia often display unusual language impairments. This is a wide ranging critical review of the literature on language in schizophrenia since the 19th century. We survey schizophrenic language level by level, from phonetics through phonology, morphology, syntax, semantics, and pragmatics. There are at least two kinds of impair...

This paper presents an algorithm for finding probably correct alignments on the basis of phonetic similarity. The algorithm consists of an evaluation metric and a guided search procedure. The search algorithm can be extended to implement special handling of metathesis, assimilation, or other phenomena that require looking ahead in the string, and c...

The author tests some astrocameras.

An essential step in comparative reconstruction is to align corresponding phonological segments in the words being compared. To do this, one must search among huge numbers of potential alignments to find those that give a good phonetic fit. This is a hard computational problem, and it becomes exponentially more difficult when more than two strings...

This paper presents a tokenizer for English text, including numerals, that is implemented in Prolog using DCG rules. It is thus a top-down recursivedescent parser rather than a finite-state automaton. The lower e#ciency of this parsing algorithm does not seriously degrade performance, and it makes the tokenizer much easier to modify for unusual kin...

Many telescopes still use 50 or 60Hz AC motors controlled by variable-frequency AC power sources. This paper describes a programmed microcontroller that can be used as the oscillating element in such drive controllers, providing efficient two-phase drive, smooth frequency changes, and precise sidereal and lunar rates.

This paper presents several variations on a fundamental algorithm for parsing natural language into dependency trees. Unlike phrase-structure (constituency) parsers, this algorithm operates one word at a time, attaching each word as soon as it can be attached. There is good evidence that the parsing process used by the human mind has these properti...

this paper is to present, in concise form, some basic information about the New Testament compiled for my own use. This paper is intended to be usable by readers who do not know Greek as well as those who are studying, or have studied, New Testament Greek. I would appreciate feedback from anyone with suggestions or corrections. 1.1 Author's qualifi...

The elevator control program of Dyck and Caines (1995) can be implemented more concisely in d-Prolog, a defeasible logic programming system developed by Nute (1992, 1996, 1997). To demonstrate this, the program is recast, first into ordinary Prolog and then into d-Prolog. In defeasible logic, more specific rules take precedence over more general on...

Properly used, Prolog is as fast as any language with com- parable power. This paper presents guidelines for using Prolog effi- ciently. Some of these guidelines rely on implementation- dependent features such as indexing and tail recursion optimization; others are matters of pure algorithmic complexity.

This paper documents GULP 3.1, a simple extension to Prolog that facilitates implementation of unification--based grammars (UBGs) by adding a notation for feature structures. For example, a:b..c:d denotes a feature structure in which a has the value b, c has the value d, and the values of all other features are unspecified. A modified Prolog interp...

Introduction 2. Variable word order: the problem 3. Dependency grammar (DG) 4. Unification-based dependency grammar 5. The parsing algorithm 6. The implementation 7. Evaluation of the IBM 3090 environment 8. Remaining issues 9. Conclusions 1 Introduction This paper presents a new approach to the recognition of sentence structure by computer in huma...

Introduction An alignment is a way of pairing up elements of two strings, optionally skipping some elements but preserving the order. For example, a b c a b c a b c --- --- --- --- --- --- --- x y z x y z x y z are three of the many alignments of abc with xyz. For brevity we will write them as ( abc xyz ), ( abc- -xyz ), and ( abcx -yz ) respective...

Defeasible logic is a system of reasoning in which rules have exceptions, and when rules conflict, the one that applies most specifically to the situation wins out. This paper reports a successful application of defeasible logic to the implementation of an embedded control system. The system was programmed in d-Prolog (a defeasible extension of Pro...

Many Latin inflectional endings share material constituting less than a whole morpheme. Conventional linguistic analysis must either ignore the shared material (treating it as historical relics) or make it into morphemes through abstract morphophonemics, poorly motivated in Latin. The shared material contributes to economy of representation when th...

Dependency grammar is usually interpreted as equivalent to a strict form of X--bar theory that forbids the stacking of nodes of the same bar level (e.g., N immediately dominating N with the same head). But adequate accounts of one--anaphora and of the semantics of multiple modifiers require such stacking and accordingly argue against dependency gra...

this paper. 1 since the inherited endings of the three cases were, in general, distinct, and the resulting Latin ablative endings came from any of the three original cases, depending on inflectional class. First-, second-, and third-declension -a(d) -o(d) -(d) generalize an inherited ablative pattern, as do the -bus plurals, but fifth-declension -e...

Speech act theory (the study of how utterances function as statements, questions, commands, etc.) is increasingly applicable to software design. KQML, a knowledge interchange language developed with ARPA funding, is based on speech act theory. It differs in significant ways from human speech and conventional EDI, and it can be improved in a number...

Speech act theory (the study of how utterances function as statements, questions, commands, etc.) is increasingly applicable to software design. KQML, a knowledge interchange language developed with ARPA funding, is based on speech act theory. It differs in significant ways from human speech and conventional EDI, and it can be improved in a number...

This paper surveys practical issues in the design of a formal language for business communication (FLBC) in which transactions are put together by combining meaningful elements, much as a programming language encodes algorithms. Such a language is preferable to existing codes such as ANSI X12 and UN EDIFACT because of its much greater versatility....

This paper examines the encoding of speech acts in KQML at length and in ANSI X12 briefly. KQML is a speech-act-based language developed with ARPA funding, and X12 is the American standard for electronic data interchange (EDI) message formats. I conclude that although speech act theory is highly relevant to electronic communication, the needs of co...

This paper presents a representation for natural language plurals in knowledge base queries, implementing collective, distributive, cumulative, and multiply distributive senses of the plural by means of higher predicates. The underlying semantics is based on Franconi's theory of collections. The collective reading of a plural applies the predicate...

The paper examines the encoding of speech acts in KQML at length and in ANSI X12 briefly. KQML is a speech act based language developed with ARPA funding, and X12 is the American standard for electronic data interchange (EDI) message formats. The author concludes that although speech act theory is highly relevant to electronic communication, the ne...

: Properly used, Prolog is as fast as any language with comparable power. This paper presents guidelines for using Prolog efficiently. Some of these guidelines rely on implementation-dependent features such as indexing and tail recursion optimization; others are matters of pure algorithmic complexity. Many people think Prolog is inefficient. This i...

The author tests some astrocameras.

The paper surveys practical issues in the design of a formal language for business communication (FLBC) in which transactions are put together by combining meaningful elements, much as a programming language encodes algorithms. Such a language is preferable to existing codes such as ANSI X.12 and UN EDIFACT because of its much greater versatility....

As the set of people using computers becomes larger and less cohesive, it is becoming important to educate users about their ethical responsibilities. Design of an effective campus computer ethics policy requires awareness of numerous cultural, technical and legal issues. Especially important are the cultural splits between power users and utilitar...

This article introduces a print filter called LaserJet 4M printer run on UNIX system. Performance of this UNIX print filter includes the capability to distinguish PostScript, HP, and ASCII code; supplies a Ctrl-D to properly terminate every PostScript job; bails out gradually if a user tries to print an unprintable binary file; displays the user's...

The dependency{based free{word{order parsing algorithm of Cov-ington (1987, 1990, 1992) can be extended to handle partly or com-pletely xed word order, while preserving its psychologically realistic preference for near attachment. By adding predictivity, this algorithm can be adapted to parse left{branching and right{branching structures in less st...

Dependency grammar is usually interpreted as equivalent to a strict form of X--bar theory that forbids the stacking of nodes of the same bar level (e.g., N immediately dominating N with the same head). But adequate accounts of one--anaphora and of the semantics of multiple modifiers require such stacking and accordingly argue against dependency gra...

The Prolog inference engine can be extended to solve for unknowns in arithmetic equations such as XGamma1=1/X or X=cos(X), whether or not the equations have analytic solutions. This is done by standard numerical methods, but two features of Prolog make the implementation easy: the ability to treat expressions as data and the ability of the program...

ABSTRACT: A simple extension to Prolog facilitates implementation of unification-based grammars (UBGs) by adding a new notational device, the feature structure, whose behavior emulates graph unification. For example, a:b..c:d denotes a feature structure in which a has the value b, c has the value d, and the values of all other features are unspecif...

The interdisciplinary Master of Science program in Artificial Intelligence at the University of Georgia is intended to prepare students for careers as developers of artificial intelligence applications or for further graduate work in artificial intelligence or related areas. The program includes foundational courses in computer science, linguistics...

The 18 papers in this book are selected from the 45 presented at the International Workshop on Parsing Technologies (IWPT-89) sponsored by Carnegie-Mellon University. Papers dealing with Tomita's own parsing algorithm are published in a separate book Tomita, Generalized LR Parsing, Kluwer, 1991).

This tutorial presents twelve guidelines for making Prolog programs efficient. Topics covered include procedural versus declarative programming, internal representation of data, first-argument indexing, cuts, and ways to avoid consing.

This paper presents a simple technique for building a list of the Syntax errors during parsing of a natural language sentences. The technique depends only on merging of feature structures and is independent of the parsing algorithm used. It can identify multiple errors in a single sentence and identify the specific words involved in an error. A Sam...

With this extraordinary handbook, you, too, can frame the stars and have them hanging on your livingroom walls. Astrophotography for the Amateur provides a complete guide to taking pictures of stars, galaxies, the Moon, the Sun, comets, meteors and eclipses, using equipment and materials readily available to the hobbyist. Based on suggestions from...

An abstract is not available.

Computers have the ability to do numerical calculations, but logic programming gives them problem-solving methods as well. As the author shows, this makes it easier to program computers to make decisions about practical problems. He discusses issues of computational power, the use of logic programming to build expert systems which provide advice ab...

This paper presents a novel method of antialiasing on the IBM VGA and similar displays that allow the programmer to use any 16 colors chosen from a large repertoire. The four bits of the color code are treated as subpixels, doubling the effective resolution in both dimensions without requiring additional video memory. The 16 colors are defined as a...

This paper documents a computer program that constructs discourse representation structures (DRSes) from ordinary English input. A source listing of the program is included. This program is a much ex- tended version of the one developed by Johnson and Klein (1986) and was built to serve as a basis for other research. It is implemented in Prolog usi...

1,Introduction/Abstract This is a preliminary report on a set of techniques for translating the dis-

The Advanced Computational Methods Center (ACMC), established at the University of Georgia (UGA) in 1984, supports several research projects in artificial intelligence. The primary goal of AI research at ACMC is the design and installation of a logic-programming environment with advanced natural language processing and knowledge-acquisition capabil...

In an earlier paper (Covington 1984) I proposed that looping in Prolog should be prevented by blocking all derivations in which the current goal matches a higher goal. This is too strong a constraint; it causes exhaustive searches to be incomplete. A better approach is to block all derivations in which the current goal matches a higher goal and is...

Modifications to Prolog are proposed that make it possible to express transitive and symmetrical relations and biconditionals. This is done by blocking recursion under circumstances that would lead to infinite loops.

At the SIGPLAN '83 conference, a panel discussion was held to discuss what the important programming language issues might be in the 1980's. This paper is an edited transcript of the discussion.I want to thank John White, General Chairman for the conference, ...