1,826 research outputs found
A Distributed Solution to the PTE Problem
Proceeding of: AAAI Spring Symposium on Predictive Toxicology, AAAI Press, Stanford, March 1999A wide panoply of machine learning methods is available for application to the Predictive Toxicology Evaluation (PTE) problem. The authors have built four monolithic classification systems based on Tilde, Progol, C4.5 and naive bayesian classification. These systems have been trained using the PTE dataset, and their accuracy has been tested using the unseen PTE1 data set as test set. A Multi Agent Decision System (MADES) has been built using the aforementioned monolithic systems to build classification agents. The MADES was trained and tested with the same data sets used with the monolithic systems. Results show that the accuracy of the MADES improves the accuracies obtained by the monolithic systems. We believe that in most real world domains the combination of several approaches is stronger than the individuals. Introduction The Predictive Toxicology Evaluation (PTE) Challenge (Srinivasan et al. 1997) was devised by the Oxford University Computing Laboratory to test the suitability ...Publicad
System-of-Systems Complexity
The global availability of communication services makes it possible to
interconnect independently developed systems, called constituent systems, to
provide new synergistic services and more efficient economic processes. The
characteristics of these new Systems-of-Systems are qualitatively different
from the classic monolithic systems. In the first part of this presentation we
elaborate on these differences, particularly with respect to the autonomy of
the constituent systems, to dependability, continuous evolution, and emergence.
In the second part we look at a SoS from the point of view of cognitive
complexity. Cognitive complexity is seen as a relation between a model of an
SoS and the observer. In order to understand the behavior of a large SoS we
have to generate models of adequate simplicity, i.e, of a cognitive complexity
that can be handled by the limited capabilities of the human mind. We will
discuss the importance of properly specifying and placing the relied-upon
message interfaces between the constituent systems that form an open SoS and
discuss simplification strategies that help to reduce the cognitive complexity.Comment: In Proceedings AiSoS 2013, arXiv:1311.319
From Monolithic Systems to Microservices: An Assessment Framework
Context. Re-architecting monolithic systems with Microservices-based
architecture is a common trend. Various companies are migrating to
Microservices for different reasons. However, making such an important decision
like re-architecting an entire system must be based on real facts and not only
on gut feelings. Objective. The goal of this work is to propose an
evidence-based decision support framework for companies that need to migrate to
Microservices, based on the analysis of a set of characteristics and metrics
they should collect before re-architecting their monolithic system. Method. We
designed this study with a mixed-methods approach combining a Systematic
Mapping Study with a survey done in the form of interviews with professionals
to derive the assessment framework based on Grounded Theory. Results. We
identified a set consisting of information and metrics that companies can use
to decide whether to migrate to Microservices or not. The proposed assessment
framework, based on the aforementioned metrics, could be useful for companies
if they need to migrate to Microservices and do not want to run the risk of
failing to consider some important information
ILS Assessment: A Background Document
This document is intended as a first step in evaluating the current environment with respect to Integrated Library Systems (ILS). To date ILSs have been proprietary monolithic systems encompassing the major operations of the library: circulation, acquisitions, cataloguing and a public catalogue or OPAC
Runtime Enforcement for Component-Based Systems
Runtime enforcement is an increasingly popular and effective dynamic
validation technique aiming to ensure the correct runtime behavior (w.r.t. a
formal specification) of systems using a so-called enforcement monitor. In this
paper we introduce runtime enforcement of specifications on component-based
systems (CBS) modeled in the BIP (Behavior, Interaction and Priority)
framework. BIP is a powerful and expressive component-based framework for
formal construction of heterogeneous systems. However, because of BIP
expressiveness, it remains difficult to enforce at design-time complex
behavioral properties.
First we propose a theoretical runtime enforcement framework for CBS where we
delineate a hierarchy of sets of enforceable properties (i.e., properties that
can be enforced) according to the number of observational steps a system is
allowed to deviate from the property (i.e., the notion of k-step
enforceability). To ensure the observational equivalence between the correct
executions of the initial system and the monitored system, we show that i) only
stutter-invariant properties should be enforced on CBS with our monitors, ii)
safety properties are 1-step enforceable. Given an abstract enforcement monitor
(as a finite-state machine) for some 1-step enforceable specification, we
formally instrument (at relevant locations) a given BIP system to integrate the
monitor. At runtime, the monitor observes and automatically avoids any error in
the behavior of the system w.r.t. the specification. Our approach is fully
implemented in an available tool that we used to i) avoid deadlock occurrences
on a dining philosophers benchmark, and ii) ensure the correct placement of
robots on a map.Comment: arXiv admin note: text overlap with arXiv:1109.5505 by other author
Extensible Technology-Agnostic Runtime Verification
With numerous specialised technologies available to industry, it has become
increasingly frequent for computer systems to be composed of heterogeneous
components built over, and using, different technologies and languages. While
this enables developers to use the appropriate technologies for specific
contexts, it becomes more challenging to ensure the correctness of the overall
system. In this paper we propose a framework to enable extensible technology
agnostic runtime verification and we present an extension of polyLarva, a
runtime-verification tool able to handle the monitoring of
heterogeneous-component systems. The approach is then applied to a case study
of a component-based artefact using different technologies, namely C and Java.Comment: In Proceedings FESCA 2013, arXiv:1302.478
Learning Design and Service Oriented Architectures:a mutual dependency?
This paper looks at how the concept of reusability has gained currency in e-learning. Initial attention was focused on reuse of content, but recently attention has focused on reusable software tools and reusable activity structures. The former has led to the proposal of service-oriented architectures, and the latter has seen the development of the Learning Design specification. The authors suggest that there is a mutual dependency between the success of these two approaches, as complex Learning Designs require the ability to call on a range of tools, while remaining technology neutral.
The paper describes a project at the UK Open University, SLeD, which sought to develop a Learning Design player that would utilise the service-oriented approach. This acted both as a means of exploring some of the issues implicit within both approaches and also provided a practical tool. The SLeD system was successfully implemented in a different university, Liverpool Hope, demonstrating some of the principles of re-use
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