Elena García

Empirical findings on team size and productivity in software development

The size of software project teams has been considered to be a driver of project productivity. Although there is a large literature on this, new publicly available software repositories allow us to empirically perform further research. In this paper we analyse the relationships between productivity, team size and other project variables using the International Software Benchmarking Standards Group (ISBSG) repository. To do so, we apply statistical approaches to a preprocessed subset of the ISBSG repository to facilitate the study. The results show some expected correlations between productivity, effort and time as well as corroborating some other beliefs concerning team size and productivity. In addition, this study concludes that in order to apply statistical or data mining techniques to these type of repositories extensive preprocessing of the data needs to be performed due to ambiguities, wrongly recorded values, missing values, unbalanced datasets, etc. Such preprocessing is a difficult and error prone activity that would need further guidance and information that is not always provided in the repository.

Complete metadata records in learning object repositories: some evidence and requirements

Completeness of e-learning objects metadata records becomes a key requirement for learning object repositories, since these repositories are called to play a central role in automated approaches to e-learning. Nonetheless, metadata creation is a time-consuming and laborious process. These two factors may eventually result in incomplete and poorly structured metadata. In this paper, the completeness of learning object metadata of samples obtained from the MERLOT and CAREO repositories is analysed from that viewpoint, using the IEEE LOM standard as a reference framework. The paper concludes with a proposal for the specification of completeness levels as compliancy requirements for learning-related services or processes.

Defining Software Process Model Constraints with Rules Using OWL and SWRL

The Software & Systems Process Engineering meta-model (SPEM) allows the modelling of software processes using OMG (Object Management Group) standards such as the MOF (Meta-Object Facility) and UML (Unified Modelling Language) making it possible to represent software processes using tools compliant with UML. Process definition encompasses both the static and dynamic structure of roles, tasks and work products together with imposed constraints on those elements. However, the latter requires support for constraint enforcement that is not always directly available in SPEM. Such constraint-checking behaviour could be used to detect possible mismatches between process definitions and the actual processes being carried out in the course of a project. This paper approaches the modelling of such constraints using the SWRL (Semantic Web Rule Language), which is a W3C recommendation. To do so, we need to first represent generic processes modelled with SPEM using an underlying ontology based on the OWL (Ontology Web Language) representation together with data derived from actual projects.

Estimation of the parameters of cardiac function and of blood volume by arterial thermodilution in an infant animal model.

Background:  Experimental studies in adults and in animals have reported that estimation of the intracardiac volumes by arterial thermodilution is a more reliable method of blood volume estimation than pressure measurement. The objective of this study has been to analyze the values of cardiac function and blood volume in an infant animal model using the arterial thermodilution technique.

Using links to describe imprecise relationships in educational contents

Hypermedia links describe purposeful relationships between contents, and in consequence, their semantic intention can be modelled by the notion of link type. Ontologies can be used to extend that notion of link type, eventually resulting in shared conceptualisations useful in achieving consistent linking practices. In addition, the relationship embodied by the link is in many cases inherently imprecise, which has been overlooked in existing systems. In this work, we describe how ontologies of link types with support for expressing imprecision can be used to enhance educational web contents. The computational semantics of the ontology, combined with fuzziness to specify graded relations between pairs of link sources and targets for specific users or groups, enable the implementation of extended adaptive behaviours that may entail inferences and approximate reasoning. An implementation, based on an SCORM-compliant runtime environment, of such kind of extended links is also described, demonstrating their capabilities in the definition of learning-oriented adaptations.

Correlation between cardiac output measured by the femoral arterial thermodilution technique pulmonary arterial and that measured by contour pulse analysis in a paediatric animal model

Objective. To evaluate the correlation between two methods for the determination of cardiac output: the femoral arterial thermodilution technique (FATD) and the arterial pulse contour analysis (PCCO) using the PiCCO catheter. Methods. We performed a prospective animal study using 51 immature Maryland pigs weighing 9 to 16 kg. A 4- or 5-Fr arterial PiCCO catheter was introduced into the femoral artery. In each animal, we made measurements of cardiac output at 30-minute intervals by femoral arterial thermodilution for a total of 209 measurements. We registered the previous PCCO and compared with the mean of two measures of FATD cardiac output. Results. Mean FATD was 1.73 ± 0.60 L/min and mean PCCO was 1.78 ± 0.70 L/min (no significant difference). The mean difference (bias) of differences (limits of agreement) was 0.04. The correlation founded between the two methods was 0.786 (95% confidence interval, 0.71–0.83). Conclusions. Femoral arterial thermodilution cardiac output measurements correlates well with pulse contour analysis cardiac output in this paediatric animal model.

On integrating learning object metadata inside the OpenCyc knowledge base

The integration of learning objects with semantic Web technologies requires the representation of learning object metadata in ontological databases. In this paper, some of the issues regarding the expression of learning object specifications as part of the OpenCyc terminological knowledge base are discussed, illustrating some of the advanced behaviors that are enabled by such integration.

On fuzziness in relationship value segmentation: applications to personalized e-commerce

Relationship marketing strategies focus on the construction and maintenance of tailored relationship with customers. Consequently, electronic commerce systems following the relationship approach may benefit from Web personalization techniques in tailoring the interaction with its users according to an evolving customer model. In this context, relationship-value market segmentation becomes a central customer modeling activity. But value segmentation categories are inherently vague due to the use of imprecise linguistic categories, combined with a degree of uncertainty about customer behavior, and the difficulty inherent to estimating intangible variables. In this paper, a fuzzy approach to value segmentation is described, allowing more flexible customer segments. Fuzzy models of value estimations are represented by fuzzy triangular numbers, and two segmentation approaches, directed and discovery-oriented are briefly described. The usefulness of the approach is then illustrated through concrete personalization techniques based on those fuzzy categories.

Designing Ontology-Based Interactive Information Retrieval Interfaces

The instant invention relates to a method of converting the solid organic fraction of solid waste into a powdered fuel which comprises heating said solid organic fraction in the presence of an organic acid for a time and at a temperature sufficient to embrittle said solid organic fraction, comminuting said embrittled solid organic fraction to a powder which is less than a predetermined particle size, and recovering said powder. The solid organic fraction may be separated from the solid waste prior to treatment by the process of this invention or alternatively the solid waste can be treated by the method of this invention and the embrittled organic fraction separated therefrom. The organic acid may be added to the solid organic fraction as an aqueous solution, a gas, or solid, preferably as an aqueous solution of oxalic acid. The embrittling process takes place at a temperature of at least 125 DEG C., preferably from 150 DEG C. to 250 DEG C. and said embrittled solid organic fraction is preferably comminuted to a predetermined article size of less than 10 mesh.

Fuzziness in adaptive hypermedia models

Diverse forms of imperfect information arise in the context of adaptive hypermedia systems, and especially in personalized Web applications, where the user population is fairly diverse. Several adaptive hypermedia systems have been developed that deal explicitly with some form of uncertainty or imprecision, but hypermedia models largely ignore these aspects. In this paper, an extension of the static part of a hypermedia model is described, to address some forms of extended information. Specifically, fuzzy set theory is used to extend some of the model elements, including user categories and links, resulting in more realistic information definitions and also in novel concepts, like fuzzy links, that are generalizations of well-known adaptive techniques. An extension of the UML notation is also described, to visually represent imprecision when modeling an adaptive system.