Clinical Processes - The Killer Application for Constraint-Based Process Interactions?

For more than a decade, the interest in aligning information systems in a process-oriented way has been increasing. To enable operational support for business processes, the latter are usually specified in an imperative way. The resulting process models, however, tend to be too rigid to meet the flexibility demands of the actors involved. Declarative process modeling languages, in turn, provide a promising alternative in scenarios in which a high level of flexibility is demanded. In the scientific literature, declarative languages have been used for modeling rather simple processes or synthetic examples. However, to the best of our knowledge, they have not been used to model complex, real-world scenarios that comprise constraints going beyond control-flow. In this paper, we propose the use of a declarative language for modeling a sophisticated healthcare process scenario from the real world. The scenario is subject to complex temporal constraints and entails the need for coordinating the constraint-based interactions among the processes related to a patient treatment process. As demonstrated in this work, the selected real process scenario can be suitably modeled through a declarative approach.Ministerio de Economía y Competitividad TIN2016-76956-C3-2-RMinisterio de Economía y Competitividad TIN2015-71938-RED

Improving Prolog Programs: Refactoring for Prolog

Refactoring is an established technique from the OO-community to restructure code: it aims at improving software readability, maintainability and extensibility. Although refactoring is not tied to the OO-paradigm in particular, its ideas have not been applied to Logic Programming until now. This paper applies the ideas of refactoring to Prolog programs. A catalogue is presented listing refactorings classified according to scope. Some of the refactorings have been adapted from the OO-paradigm, while others have been specifically designed for Prolog. Also the discrepancy between intended and operational semantics in Prolog is addressed by some of the refactorings. In addition, ViPReSS, a semi-automatic refactoring browser, is discussed and the experience with applying \vipress to a large Prolog legacy system is reported. Our main conclusion is that refactoring is not only a viable technique in Prolog but also a rather desirable one.Comment: To appear in ICLP 200

SPEST - A TOOL FOR SPECIFICATION-BASED TESTING

This thesis presents a tool for SPEcification based teSTing (SPEST). SPEST is designed to use well known practices for automated black-box testing to reduce the burden of testing on developers. The tool uses a simple formal specification language to generate highly-readable unit tests that embody best practices for thorough software testing. Because the specification language used to generate the assertions about the code can be compiled, it can also be used to ensure that documentation describing the code is maintained during development and refactoring. The utility and effectiveness of SPEST were validated through several exper- iments conducted with students in undergraduate software engineering classes. The first experiment compared the understandability and efficiency of SPEST generated tests against student written tests based on the Java Modeling Lan- guage (JML)[25] specifications. JML is a widely used language for behavior program specification. A second experiment evaluated readability through a sur- vey comparing SPEST generated tests against tests written by well established software developers. The results from the experiments showed that SPEST’s specification language is at least understandable as JML, SPEST’s specification language is more readable than JML, and strongly suggest that SPEST is capable of reducing the effort required to produce effective tests

Fundamentalists Clashing over the Book: A Study of Order-Driven Stock Markets

Agent-based models of market dynamics must strike a compromise between the structural assumptions that represent the trading mechanism and the behavioral assumptions that describe the rules by which traders take their decisions. We present a structurally detailed model of an order- driven stock market and show that a minimal set of behavioral assumptions suffices to generate a leptokurtic distribution of short- term log-returns. This result backs up the conjecture that the emergence of some statistical properties of financial time series is due to the microstructure of stock markets.price dynamics, statistical properties of returns, behavioral and structural assumptions, agent-based simulations