COSMA - multi-participant NL interaction for appointment scheduling

We discuss the use of NL systems in the domain of appointment scheduling. Appointment scheduling is a problem faced daily by many people and organizations, and typically solved using communication in natural language. In general, cooperative interaction between several participants is required whose calendar data are distributed rather than centralized. In this distributed multi-agent environment, the use of NL systems makes it possible for machines and humans to cooperate in solving scheduling problems. We describe the COSMA (Cooperative Schedule Managament Agent) system, a secretarial assistant for appointment scheduling. A central part of COSMA is the reusable NL core system DISCO, which serves, in this application, as an NL interface between an appointment planning system and the human user. COSMA is fully implemented in Common Lisp and runs on Unix Workstations. Our experience with COSMA shows that it is a plausible and useful application for NL systems. However, the appointment planner was not designed for NL communication and thus makes strong assumptions about sequencing of domain actions and about the error-freeness of the communication. We suggest that further improvements of the overall COSMA functionality, especially with regard to flexibility and robustness, be based on a modified architecture

Abductive speech act recognition, corporate agents and the COSMA system

This chapter presents an overview of the DISCO project\u27s solutions to several problems in natural language pragmatics. Its central focus is on relating utterances to intentions through speech act recognition. Subproblems include the incorporation of linguistic cues into the speech act recognition process, precise and efficient multiagent belief attribution models (Corporate Agents), and speech act representation and processing using Corporate Agents. These ideas are being tested within the COSMA appointment scheduling system, one application of the DISCO natural language interface. Abductive speech act processing in this environment is not far from realizing its potential for fully bidirectional implementation

A derivation of a microscopic entropy and time irreversibility from the discreteness of time

All of the basic microsopic physical laws are time reversible. In contrast, the second law of thermodynamics, which is a macroscopic physical representation of the world, is able to describe irreversible processes in an isolated system through the change of entropy S larger than 0. It is the attempt of the present manuscript to bridge the microscopic physical world with its macrosocpic one with an alternative approach than the statistical mechanics theory of Gibbs and Boltzmann. It is proposed that time is discrete with constant step size. Its consequence is the presence of time irreversibility at the microscopic level if the present force is of complex nature (i.e. not const). In order to compare this discrete time irreversible mechamics (for simplicity a classical, single particle in a one dimensional space is selected) with its classical Newton analog, time reversibility is reintroduced by scaling the time steps for any given time step n by the variable sn leading to the Nose-Hoover Lagrangian. The corresponding Nose-Hoover Hamiltonian comprises a term Ndf *kB*T*ln(sn) (with kB the Boltzmann constant, T the temperature, and Ndf the number of degrees of freedom) which is defined as the microscopic entropy Sn at time point n multiplied by T. Upon ensemble averaging this microscopic entropy Sn in equilibrium for a system which does not have fast changing forces approximates its macroscopic counterpart known from thermodynamics. The presented derivation with the resulting analogy between the ensemble averaged microscopic entropy and its thermodynamic analog suggests that the original description of the entropy by Boltzmann and Gibbs is just an ensemble averaging of the time scaling variable sn which is in equilibrium close to 1, but that the entropy term itself has its root not in statistical mechanics but rather in the discreteness of time

An emperical model for heterogeneous translucent objects

We introduce an empirical model for multiple scattering in heterogeneous translucent objects for which classical approximations such as the dipole approximation to the di usion equation are no longer valid. Motivated by the exponential fall-o of scattered intensity with distance, di use subsurface scattering is represented as a sum of exponentials per surface point plus a modulation texture. Modeling quality can be improved by using an anisotropic model where exponential parameters are determined per surface location and scattering direction. We validate the scattering model for a set of planar object samples which were recorded under controlled conditions and quantify the modeling error. Furthermore, several translucent objects with complex geometry are captured and compared to the real object under similar illumination conditions

Implementation of a Database System with Boolean Algebra Constraints

This thesis describes an implementation of a constraint database system with constraints over a Boolean Algebra of sets. The system allows within the input database as well as the queries equality, subset-equality and monotone inequality constraints between Boolean Algebra terms built up using the operators of union, intersection and complement. Hence the new system extends the earlier DISCO system, which only allowed equality and subset-equality constraints between Boolean algebra variables and constants. The new system allows Datalog with Boolean Algebra constraints as the query lan- guage. The implementation includes an extension of Naive and Semi-Naive evaluation methods for Datalog programs and algebraic optimization techniques for relational algebra formulas. The thesis also includes three example applications of the new system in the area of family tree genealogy, genome map assembly, and two-player game analysis. In each of these three cases the optimization provides a significant improvement in the running time of the queries. Advisor: Peter Z. Reves

Primer: Support Technologies for Human Rights Lawyers

Paper, pens and manila folders. A phone. Microsoft Word (with track changes) and email. Perhaps a spreadsheet for tracking billable time, and shared folders on a server to store documents... this is probably how you work if you're a human rights lawyer. While we don't hear much about technology use outside of this common scenario we do hear about common challenges: being overwhelmed with cases that can last years, working in multiple languages across different jurisdictions with different processes, enduring pressure and surveillance from the states and corporations who you litigate against. We also know you're short of resource and access to technical expertise. This document looks at the place that technologies may have in helping you meeting these challenges. In this primer, we'll look at three classes of technologies which may be helpful: ? Case and practice management tools, for managing the day-to-day flow of information around a case, such as the exchange of documents, task management and dates. ? E-Discovery tools for digitising, organising and reviewing collections of documents, data or other material that could be evidence in a case. ? Investigation and case building tools, for organising and analysing the facts of a case or group of cases, providing visual overviews on maps, network charts and timelines

Scaling Heterogeneous Databases and the Design of Disco

Access to large numbers of data sources introduces new problems for users of heterogeneous distributed databases. End users and application programmers must deal with unavailable data sources. Database administrators must deal with incorporating new sources into the model. Database implementors must deal with the translation of queries between query languages and schemas. The Distributed Information Search COmponent (Disco) 1 addresses these problems. Query processing semantics are developed to process queries over data sources which do not return answers. Data modeling techniques manage connections to data sources. The component interface to data sources flexibly handles different query languages and translates queries. This paper describes (a) the distributed mediator architecture ofDisco, (b) its query processing semantics, (c) the data model and its modeling of data source connections, and (d) the interface to underlying data sources. 1

Geography of African development : an alternative curriculum

The Geography of African Development module is part of a year-long Third Year level geography course on Africa that has been offered at Rhodes University since 2002. The course is an exception to the dominant trend, both locally and internationally, which has witnessed a major decline in the teaching of regional geography and area studies. This paper examines how adopting a constructivist approach to the module's curriculum enabled learners to develop geographical skills at the same time as Africanising the curriculum