The AXML Artifact Model

International audienceTowards a data-centric workflow approach, we introduce an artifact model to capture data and workflow management activities in distributed settings. The model is built on Active XML, i.e., XML trees including Web service calls. We argue that the model captures the essential features of business artifacts as described informally in [1] or discussed in [2]. To illustrate, we briefly consider the monitoring of distributed systems and the verification of temporal properties for them

Verifying Recursive Active Documents with Positive Data Tree Rewriting

This paper proposes a data tree-rewriting framework for modeling evolving documents. The framework is close to Guarded Active XML, a platform used for handling XML repositories evolving through web services. We focus on automatic verification of properties of evolving documents that can contain data from an infinite domain. We establish the boundaries of decidability, and show that verification of a {\em positive} fragment that can handle recursive service calls is decidable. We also consider bounded model-checking in our data tree-rewriting framework and show that it is \nexptime-complete

Sequencing educational resources with Seqins

Existing adaptive educational hypermedia systems have been using learning resources sequencing approaches in order to enrich the learning experience. In this context, educational resources, either expository or evaluative, play a central role. However, there is a lack of tools that support sequencing essentially due to the fact that existing specifications are complex. This paper presents Seqins as a sequencing tool of digital educational resources. Seqins includes a simple and flexible sequencing model that will foster heterogeneous students to learn at different rhythms. The tool communicates through the IMS Learning Tools Interoperability specification with a plethora of e-learning systems such as learning management systems, repositories, authoring and automatic evaluation systems. In order to validate Seqins we integrate it in an e-learning Ensemble framework instance for the computer programming learning domain

In search of lost introns

Many fundamental questions concerning the emergence and subsequent evolution of eukaryotic exon-intron organization are still unsettled. Genome-scale comparative studies, which can shed light on crucial aspects of eukaryotic evolution, require adequate computational tools. We describe novel computational methods for studying spliceosomal intron evolution. Our goal is to give a reliable characterization of the dynamics of intron evolution. Our algorithmic innovations address the identification of orthologous introns, and the likelihood-based analysis of intron data. We discuss a compression method for the evaluation of the likelihood function, which is noteworthy for phylogenetic likelihood problems in general. We prove that after $O(nL)$ preprocessing time, subsequent evaluations take $O(nL/\log L)$ time almost surely in the Yule-Harding random model of $n$-taxon phylogenies, where $L$ is the input sequence length. We illustrate the practicality of our methods by compiling and analyzing a data set involving 18 eukaryotes, more than in any other study to date. The study yields the surprising result that ancestral eukaryotes were fairly intron-rich. For example, the bilaterian ancestor is estimated to have had more than 90% as many introns as vertebrates do now

Creating an android application for acquaintance with historical buildings and places

https://www.ester.ee/record=b544778

Automating the Generation of Heterogeneous Aviation Safety Cases

A safety case is a structured argument, supported by a body of evidence, which provides a convincing and valid justification that a system is acceptably safe for a given application in a given operating environment. This report describes the development of a fragment of a preliminary safety case for the Swift Unmanned Aircraft System. The construction of the safety case fragment consists of two parts: a manually constructed system-level case, and an automatically constructed lower-level case, generated from formal proof of safety-relevant correctness properties. We provide a detailed discussion of the safety considerations for the target system, emphasizing the heterogeneity of sources of safety-relevant information, and use a hazard analysis to derive safety requirements, including formal requirements. We evaluate the safety case using three classes of metrics for measuring degrees of coverage, automation, and understandability. We then present our preliminary conclusions and make suggestions for future work

Research in Business Process Management: A bibliometric analysis

It contains several growing subtopics such as process mining, process flexibility and process compliance. BPM is also highly relevant for numerous related fields, such as Business Intelligence, ERP systems or Knowledge Management. The growing number of publications and the variety of topics in BPM make it useful to apply bibliometric methods on this scientific field. With bibliometric methods, topical clusters, essential authors and the relationships between them can be discovered. In this work, the BibTechMon software from the Austrian Institute of Technology is utilized to perform the bibliometric analyses. As a novelty for the work with BibTechMon, data from Google Scholar is used as the basis of the analyses. The nature of Google Scholar data differs significantly from the data of other scientific databases. These differences lead to changes on how the bibliometric analyses can be performed. After these changes have been assessed, several bibliometric analyses in the BPM field and related fields are performed. As a result of these analyses, diverse topical clusters in BPM and its related fields could be discovered. Additionally, important authors for each cluster and for the BPM field as a whole were determined. In order to evaluate the results of the bibliometric analyses, I conducted an interview on BPM with Professor Reichert, who is an active researcher in the field. Subsequently, his statements are compared with the results of the bibliometric analyses and the match between the bibliometric analyses and his statements is assessed

Bacterial symbionts of termite gut flagellates: cospeciation and nitrogen fixation in the gut of dry-wood termites

The subject of this thesis is the symbiosis between flagellates and bacteria in the gut of dry-wood termites (Kalotermitidae). In a series of studies, the evolution of devescovinid flagellates and their bacterial symbionts was elucidated, and the physiological basis of the symbiosis was investigated, with a focus on nitrogen fixation. Devescovinid flagellates are the dominant flagellates in the gut of Kalotermitidae. Species-pure suspensions of devescovinid flagellates (Devescovina and Metadevescovina species) from a wide range of termite species in the family Kalotermitidae were isolated with micropipettes. Ribosomal RNA gene sequences of the host flagellates and their bacterial symbionts were obtained using a full-cycle-rRNA approach. Phylogenetic analysis showed that Devescovina spp. present in many species of Kalotermitidae form a monophyletic group. They were consistently associated with a distinct lineage of ectosymbionts, which form a monophyletic group among the Bacteroidales. The well-supported congruence of their phylogenies documented strict cospeciation of flagellates and their ectosymbionts, which were temporarily classified as “Candidatus Armantifilum devescovinae”. Nevertheless, the complete incongruence between the phylogenies of devescovinid flagellates and Kalotermitidae (COII genes) demonstrated horizontal transfer of flagellates among several species of Kalotermitidae. The presence of filamentous “A. devescovinae” on the surface of Devescovina spp. was corroborated with scanning electron microscopy and fluorescent in situ hybridization. However, several Metadevescovina species, which form a sister group of Devescovina spp., did not possess Bacteroidales ectosymbionts. Moreover, a combination of molecular analysis and electron microscopy led to a correction of the previously overestimated diversity of Metadevescovina species in the gut of termite Incisitermes marginipennis. In contrast to the Bacteroidales ectosymbionts, the endosymbionts of Devescovina spp., which belong to the so-called “Endomicrobia” (TG-1 phylum) and consistently colonized the cytoplasm of all flagellates of this group, were clearly polyphyletic. This suggested that they were acquired independently by each host species. The same seems to be true for the Bacteroidales ectosymbionts of the Oxymonas flagellates present in several Kalotermitidae. These ectosymbionts form several distantly related novel lineages in the phylogenetic tree, underscoring the notion that evolutionary histories of flagellate–bacteria symbioses in the termite gut are complex. Kalotermitidae are known to fix large amounts of atmospheric nitrogen, and acetylene reduction assay showed the presence of nitrogenase activity in the gut of these termites. Community fingerprinting of the nitrogenase genes (homologs of nifH) by T-RFLP analysis revealed that a gene encoding an alternative nitrogenase (anfH) of unknown origin was most highly expressed homolog in mRNA-based profiles. Cloning of the nifH homologs from capillary-picked suspensions of Devescovina arta and Snyderella tabogae gave strong evidence that the “A. devescovinae” are the putative carriers of the anfH gene and therefore responsible for most of the nitrogen-fixing activity in the guts of Neotermes castaneus and Cryptotermes longicollis. Despite a high diversity of nifH homologs in gut homogenates, the only other homologs that were expressed belonged to Treponema, Bacteroidales (nifH), and the proteo-cyano group. The gene expression profiles were specific for the termites. The anfH genes were not expressed in termite species that accumulated large amounts of hydrogen (35–45 kPa, microsensor measurements), suggesting a repression of gene expression by high hydrogen partial pressure

Complexité de l'algorithme de l'opacité dans les systèmes Workflows centrés sur les documents

International audienceA property (of an object) is opaque to an observer when he or she cannot deduce the property from its set of observations. If each observer is attached to a given set of properties (the so-called secrets), then the system is said to be opaque if each secret is opaque to the corresponding observer. We study in this paper, the complexity of opacity algorithm in data-centric workflows systems. We show that the complexity of this algorithm is EXPTIME-complete. Using the reduction problem, whe show that we can reduce the complexity of opacity problem to wellknow problem, the intersection of nonemptyness problem of Tree automata in polynomial time.Une propriété d'un objet est dit opaque pour un observateur si celui-ci ne peut déduire que la propriété est satisfaite sur la base de l'observation qu'il a de cet objet. Supposons qu'un certain de nombre de propriétés (appelées secrets) soient attachées à chaque intervenant d'un système, nous dirons alors que le systéme lui-même est opaque si chaque secret d'un observateur lui est opaque: il ne peut percer aucun des secrets qui lui ont été attachés. Dans ce papier, on se propose d'étudier la complexité du problème de l'opacité des artefacts d'un système à flots de tâches(système workflow). Nous présentons une formalisation optimale du prob-lème de l'opacité dans ces systèmes workflows. Nous étudions ensuite la complexité de l'algorithme de l'opacité pour ces systèmes