12976067
Reasoning about Discontinuities in the Event Calculus
This paper describes a logic-based formalism which combines techniques for reasoning about actions with standard mathematical techniques for modelling dynamic systems using the diierential calculus. The formalism inherits a robust solution to the frame problem which can handle con-currency, non-determinism, domain constraints and narrative. It also incorporates a mechanism for reasoning about the boundary conditions associated with systems of diier-ential equations deened over various intervals. This mechanism overcomes a number of drawbacks of previous systems .
10794263
E-RES: A System for Reasoning about Actions, Events and Observations
E-RES is a system that implements the Language E , a logic for reasoning about narratives of action occurrences and observations. E ’s semantics is modeltheoretic, but this implementation is based on a sound and complete reformulation of E in terms of argumentation, and uses general computational techniques of argumentation frameworks. The system derives sceptical non-monotonic consequences of a given reformulated theory which exactly correspond to consequences entailed by E ’s model-theory. The computation relies on a complimentary ability of the system to derive credulous non-monotonic consequences together with a set of supporting assumptions which is sufficient for the (credulous) conclusion to hold. E-RES allows theories to contain general action laws, statements about action occurrences, observations and statements of ramifications (or universal laws). It is able to derive consequences both forward and backward in time. This paper gives a short overview of the theoretical basis of E-RES and illustrates its use on a variety of examples. Currently, E-RES is being extended so that the system can be used for planning.
23103290
The Event Calculus in Classical Logic - Alternative Axiomatisations
15552348
Some Alternative Formulations of the Event Calculus
The Event Calculus is a narrative based formalism for reasoning about actions and change originally proposed in logic programming form by Kowalski and Sergot. In this paper we summarise how variants of the Event Calculus may be expressed as classical logic axiomatisations, and how under certain circumstances these theories may be reformulated as "action description language" domain descriptions using the Language ?. This enables the classical logic Event Calculus to inherit various provably correct automated reasoning procedures recently developed for ?.
10913688
A Case Study in Reasoning about Actions and Continuous Change
This paper shows how the Situation Calculus can be extended to deal both with `narratives' and with domains containing real-valued parameters, whose actual values may vary continuously between the occurrences of actions. In particular, a domain is represented where action occurrences may be `triggered' at instants in time when certain parameters reach particular values. Its formalisation requires the integration of several types of default reasoning. Hence Baker's circumscriptive solution to the frame problem is extended to re ect the assumptions that by default a given action does not occur at a given time point, that by default a given set of parameter values does not trigger a given action, and that by default a given action occurrence does not result in a discontinuity for a given parameter. Regarding the minimisation of discontinuities, the example illustrates how circumstances can arise where, at a particular time point, discontinuities in some parameters can be `traded' for discontinuities in others. It is argued that, in general, in such cases extra domain-speci c information will be necessary in order to eliminate anomalous models of
14511628
Interactive Simultaneous Editing of Multiple Text Regions
Simultaneous editing is a new method for automating repetitive text editing. After describing a set of regions to edit (the records), the user can edit any one record and see equivalent edits applied simultaneously to all other records. The essence of simultaneous editing is generalizing the user’s selection in one record to equivalent selections in the other records. We describe a generalization method that is fast (suitable for interactive use), domain-specific (capable of using high-level knowledge such as Java and HTML syntax), and under user control (generalizations can be corrected or overridden). Simultaneous editing is useful for source code editing, HTML editing, and scripting, as well as many other applications.
1267904
Detecting Acromegaly: Screening for Disease with a Morphable Model
Acromegaly is a rare disorder which affects about 50 of every million people. The disease typically causes swelling of the hands, feet, and face, and eventually permanent changes to areas such as the jaw, brow ridge, and cheek bones. The disease is often missed by physicians and progresses beyond where it might if it were identified and treated earlier. We consider a semi-automated approach to detecting acromegaly, using a novel combination of support vector machines (SVMs) and a morphable model. Our training set consists of 24 frontal photographs of acromegalic patients and 25 of disease-free subjects. We modelled each subject's face in an analysis-by-synthesis loop using the three-dimensional morphable face model of Blanz and Vetter. The model parameters capture many features of the 3D shape of the subject's head from just a single photograph, and are used directly for classification. We report encouraging results of a classifier built from the training set of real human subjects.
5731309
Synchronizing clipboards of multiple computers
This paper describes a new technique for transferring data between computers, the synchronized clipboard. Multiple computers can share a synchronized clipboard for all clipboard operations, so that data copied to the clipboard from one computer, using the standard Copy command, can be pasted directly on another computer using the standard Paste command. Synchronized clipboards are well-suited for a single user moving data among several computers in close proximity. We describe an implementation of synchronized clipboards that works across a wide range of existing systems, including 3Com PalmPilots, Microsoft Windows PCs, Unix workstations, and other Java-capable platforms. Our implementation adds no noticeable overhead to local copy and paste operations.
5333493
A Heuristic Approach to the Multiple Diagnoses Problem
A new heuristic model for the diagnosis of multiple related disorders in a patient case is presented. The model constructs differential diagnoses of single and related disorders, based on a medical knowledge base containing disease descriptions and linkages among diseases in the knowledge base.
6575212
Lightweight Structured Text Processing
Text is a popular storage and distribution format for information, partly due to generic text-processing tools like Unix grep and sort. Unfortunately, existing generic tools make assumptions about text format (e.g., each line is a record) that limit their applicability. Custom-built tools are one alternative, but they require substantial time investment and programming expertise. We describe a new approach, lightweight structured text processing, which overcomes these difficulties by enabling users to define text structure interactively and manipulate the structure with generic tools. Our prototype system, LAPIS, is a web browser that can highlight, filter, and sort text regions described by the user. LAPIS has several advantages over other systems: (1) the ability to define custom structure with a simple, intuitive pattern language; (2) interactive specification, showing pattern matches in context and letting users choose the most convenient combination of manual selection and pattern matching; and (3) external parsers for standard text formats. The pattern language in LAPIS, text constraints, describes text structure in high-level terms, with region relationships like before, after, in, and contains. We describe an implementation of text constraints using a novel, compact representation of region sets as collections of rectangles, or region intervals. We also illustrate some examples of applying LAPIS to web pages, text files, and source code.