The Project Scheduling Problem with Non-Deterministic Activities Duration: A Literature Review

Purpose: The goal of this article is to provide an extensive literature review of the models and solution procedures proposed by many researchers interested on the Project Scheduling Problem with nondeterministic activities duration. Design/methodology/approach: This paper presents an exhaustive literature review, identifying the existing models where the activities duration were taken as uncertain or random parameters. In order to get published articles since 1996, was employed the Scopus database. The articles were selected on the basis of reviews of abstracts, methodologies, and conclusions. The results were classified according to following characteristics: year of publication, mathematical representation of the activities duration, solution techniques applied, and type of problem solved. Findings: Genetic Algorithms (GA) was pointed out as the main solution technique employed by researchers, and the Resource-Constrained Project Scheduling Problem (RCPSP) as the most studied type of problem. On the other hand, the application of new solution techniques, and the possibility of incorporating traditional methods into new PSP variants was presented as research trends. Originality/value: This literature review contents not only a descriptive analysis of the published articles but also a statistical information section in order to examine the state of the research activity carried out in relation to the Project Scheduling Problem with non-deterministic activities duration.Peer Reviewe

A great disappearing act: the electronic analogue computer

One historian of technology has called the analogue computer 'one of the great disappearing acts of the Twentieth Century'. This paper will look briefly at the origins, development and decline of the electronic analogue computer .

Digital Ecosystems: Ecosystem-Oriented Architectures

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems, where the optimisation works at two levels: a first optimisation, migration of agents which are distributed in a decentralised peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. The Digital Ecosystem was then measured experimentally through simulations, with measures originating from theoretical ecology, evaluating its likeness to biological ecosystems. This included its responsiveness to requests for applications from the user base, as a measure of the ecological succession (ecosystem maturity). Overall, we have advanced the understanding of Digital Ecosystems, creating Ecosystem-Oriented Architectures where the word ecosystem is more than just a metaphor.Comment: 39 pages, 26 figures, journa

Anti-gout potential of selected Malaysian local fruits

This study aimed to investigate the in vitro xanthine oxidase (XO) inhibitory activity and phytochemical content of guava, water rose apple, Malay gooseberry, pineapple and ambarella. The xanthine oxidase inhibitory activity was measured spectrophotometrically at 295 nm. The phytochemical analysis tested were total phenolic, total flavonoid and total anthocyanin contents of each methanolic extract of the fruits. The highest amount of phenolic was found in ambarella (0.245 mg GAE/g) while guava had the highest amount of flavonoid (0.472 mg RE/g). Meanwhile, water rose apple had the highest anthocyanin content (5.001 mg c-3-gE/g). For the XO inhibitory activity, water rose apple displayed the lowest IC50 value (26.86 μg/mL), showing better anti-gout activity as compared to that of other fruit samples. Positive correlation between total phenolic content and XO inhibitory activity was also observed in this study. Further study on the isolation of bioactive compounds from the fruit samples that act as XO inhibitor is greatly needed in the future

Nastran's Application in Agricultural Engineering

Finite element analysis has been recognized as a valuable solution method by agricultural engineers. NASTRAN has been obtained by the Agricultural Engineering Department at the University of Georgia. The NASTRAN Thermal Analyzer has been used in the teaching program for an undergraduate course in heat transfer and will be used for a new graduate course in finite element analysis. The NASTRAN Thermal Analyzer has also been applied to several research problems in the Agricultural Engineering Department

Sample-path solutions for simulation optimization problems and stochastic variational inequalities

inequality;simulation;optimization