Characterization of XML Functional Dependencies and their Interaction with DTDs

With the rise of XML as a standard model of data exchange, XML functional dependencies (XFDs) have become important to areas such as key analysis, document normalization, and data integrity. XFDs are more complicated than relational functional dependencies because the set of XFDs satisfied by an XML document depends not only on the document values, but also the tree structure and corresponding DTD. In particular, constraints imposed by DTDs may alter the implications from a base set of XFDs, and may even be inconsistent with a set of XFDs. In this paper we examine the interaction between XFDs and DTDs. We present a sound and complete axiomatization for XFDs, both alone and in the presence of certain classes of DTDs. We show that these DTD classes form an axiomatic hierarchy, with the axioms at each level a proper superset of the previous. Furthermore, we show that consistency checking with respect to a set of XFDs is feasible for these same classes

Consistency and Certain Answers in Relational to RDF Data Exchange with Shape Constraints

We investigate the data exchange from relational databases to RDF graphs inspired by R2RML with the addition of target shape schemas. We study the problems of consistency i.e., checking that every source instance admits a solution, and certain query answering i.e., finding answers present in every solution. We identify the class of constructive relational to RDF data exchange that uses IRI constructors and full tgds (with no existential variables) in its source to target dependencies. We show that the consistency problem is coNP-complete. We introduce the notion of universal simulation solution that allows to compute certain query answers to any class of queries that is robust under simulation. One such class are nested regular expressions (NREs) that are forward i.e., do not use the inverse operation. Using universal simulation solution renders tractable the computation of certain answers to forward NREs (data-complexity). Finally, we present a number of results that show that relaxing the restrictions of the proposed framework leads to an increase in complexity

Business rules based legacy system evolution towards service-oriented architecture.

Enterprises can be empowered to live up to the potential of becoming dynamic, agile and real-time. Service orientation is emerging from the amalgamation of a number of key business, technology and cultural developments. Three essential trends in particular are coming together to create a new revolutionary breed of enterprise, the service-oriented enterprise (SOE): (1) the continuous performance management of the enterprise; (2) the emergence of business process management; and (3) advances in the standards-based service-oriented infrastructures. This thesis focuses on this emerging three-layered architecture that builds on a service-oriented architecture framework, with a process layer that brings technology and business together, and a corporate performance layer that continually monitors and improves the performance indicators of global enterprises provides a novel framework for the business context in which to apply the important technical idea of service orientation and moves it from being an interesting tool for engineers to a vehicle for business managers to fundamentally improve their businesses

Labelling Dynamic XML Documents: A GroupBased Approach

Documents that comply with the XML standard are characterised by inherent ordering and their modelling usually takes the form of a tree. Nowadays, applications generate massive amounts of XML data, which requires accurate and efficient query-able XML database systems. XML querying depends on XML labelling in much the same way as relational databases rely on indexes. Document order and structural information are encoded by labelling schemes, thus facilitating their use by queries without having to access the original XML document. Dynamic XML data, data which changes, complicates the labelling scheme. As demonstrated by much research efforts, it is difficult to allocate unique labels to nodes in a dynamic XML tree so that all structural relationships between the nodes are encoded by the labels. Static XML documents are generally managed with labelling schemes that use simple labels. By contrast, dynamic labelling schemes have extra labelling costs and lower query performance to allow random updates irrespective of the document update frequency. Given that static and dynamic XML documents are often not clearly distinguished, a labelling scheme whose efficiency does not depend on updating frequency would be useful. The GroupBased labelling scheme proposed in this thesis is compatible with static as well as dynamic XML documents. In particular, this scheme has a high performance in processing dynamic XML data updates. What differentiates it from other dynamic labelling schemes is its uniform behaviour irrespective of whether the document is static or dynamic, ability to determine all structural relationships between nodes, and the improved query performance in both types of document. The advantages of the GroupBased scheme in comparison to earlier schemes are highlighted by the experiment results

Models and Modelling between Digital and Humanities: A Multidisciplinary Perspective

This Supplement of Historical Social Research stems from the contributions on the topic of modelling presented at the workshop “Thinking in Practice”, held at Wahn Manor House in Cologne on January 19-20, 2017. With Digital Humanities as starting point, practical examples of model building from different disciplines are considered, with the aim of contributing to the dialogue on modelling from several perspectives. Combined with theoretical considerations, this collection illustrates how the process of modelling is one of coming to know, in which the purpose of each modelling activity and the form in which models are expressed has to be taken into consideration in tandem. The modelling processes presented in this volume belong to specific traditions of scholarly and practical thinking as well as to specific contexts of production and use of models. The claim that supported the project workshop was indeed that establishing connections between different traditions of and approaches toward modelling is vital, whether these connections are complementary or intersectional. The workshop proceedings address an underpinning goal of the research project itself, namely that of examining the nature of the epistemological questions in the different traditions and how they relate to the nature of the modelled objects and the models being created. This collection is an attempt to move beyond simple representational views on modelling in order to understand modelling processes as scholarly and cultural phenomena as such

Leveraging Formulae and Text for Improved Math Retrieval

Large collections containing millions of math formulas are available online. Retrieving math expressions from these collections is challenging. Users can use formula, formula+text, or math questions to express their math information needs. The structural complexity of formulas requires specialized processing. Despite the existence of math search systems and online community question-answering websites for math, little is known about mathematical information needs. This research first explores the characteristics of math searches using a general search engine. The findings show how math searches are different from general searches. Then, test collections for math-aware search are introduced. The ARQMath test collections have two main tasks: 1) finding answers for math questions and 2) contextual formula search. In each test collection (ARQMath-1 to -3) the same collection is used, Math Stack Exchange posts from 2010 to 2018, introducing different topics for each task. Compared to the previous test collections, ARQMath has a much larger number of diverse topics, and improved evaluation protocol. Another key role of this research is to leverage text and math information for improved math information retrieval. Three formula search models that only use the formula, with no context are introduced. The first model is an n-gram embedding model using both symbol layout tree and operator tree representations. The second model uses tree-edit distance to re-rank the results from the first model. Finally, a learning-to-rank model that leverages full-tree, sub-tree, and vector similarity scores is introduced. To use context, Math Abstract Meaning Representation (MathAMR) is introduced, which generalizes AMR trees to include math formula operations and arguments. This MathAMR is then used for contextualized formula search using a fine-tuned Sentence-BERT model. The experiments show tree-edit distance ranking achieves the current state-of-the-art results on contextual formula search task, and the MathAMR model can be beneficial for re-ranking. This research also addresses the answer retrieval task, introducing a two-step retrieval model in which similar questions are first found and then answers previously given to those similar questions are ranked. The proposed model, fine-tunes two Sentence-BERT models, one for finding similar questions and another one for ranking the answers. For Sentence-BERT model, raw text as well as MathAMR are used

The exploration of a category theory-based virtual Geometrical product specification system for design and manufacturing

In order to ensure quality of products and to facilitate global outsourcing, almost all the so-called “world-class” manufacturing companies nowadays are applying various tools and methods to maintain the consistency of a product’s characteristics throughout its manufacturing life cycle. Among these, for ensuring the consistency of the geometric characteristics, a tolerancing language − the Geometrical Product Specification (GPS) has been widely adopted to precisely transform the functional requirements from customers into manufactured workpieces expressed as tolerance notes in technical drawings. Although commonly acknowledged by industrial users as one of the most successful efforts in integrating existing manufacturing life-cycle standards, current GPS implementations and software packages suffer from several drawbacks in their practical use, possibly the most significant, the difficulties in inferring the data for the “best” solutions. The problem stemmed from the foundation of data structures and knowledge-based system design. This indicates that there need to be a “new” software system to facilitate GPS applications. The presented thesis introduced an innovative knowledge-based system − the VirtualGPS − that provides an integrated GPS knowledge platform based on a stable and efficient database structure with knowledge generation and accessing facilities. The system focuses on solving the intrinsic product design and production problems by acting as a virtual domain expert through translating GPS standards and rules into the forms of computerized expert advices and warnings. Furthermore, this system can be used as a training tool for young and new engineers to understand the huge amount of GPS standards in a relative “quicker” manner. The thesis started with a detailed discussion of the proposed categorical modelling mechanism, which has been devised based on the Category Theory. It provided a unified mechanism for knowledge acquisition and representation, knowledge-based system design, and database schema modelling. As a core part for assessing this knowledge-based system, the implementation of the categorical Database Management System (DBMS) is also presented in this thesis. The focus then moved on to demonstrate the design and implementation of the proposed VirtualGPS system. The tests and evaluations of this system were illustrated in Chapter 6. Finally, the thesis summarized the contributions to knowledge in Chapter 7. After thoroughly reviewing the project, the conclusions reached construe that the III entire VirtualGPS system was designed and implemented to conform to Category Theory and object-oriented programming rules. The initial tests and performance analyses show that the system facilitates the geometric product manufacturing operations and benefits the manufacturers and engineers alike from function designs, to a manufacturing and verification

On the Mechanics of Flow-Induced Vibration of Soft Corals and Particle Interception

RÉSUMÉ Les coraux mous sont des espèces marines flexibles se déformant à l’effet des écoulements d’eau. Au passage d’une vague, alors que le tronc principal vacille, un mouvement particulier est observé: les branches se mettent à vibrer rapidement, avec de petits déplacements, et transversalement à la direction de l’écoulement. Dans ce mémoire, nous expliquons l’origine de ces vibrations et cherchons leur impact sur les coraux mous. Le critère de Glauert-den Hartog étant invalidé pour une section de branche de corail idéalisée, et les fluctuations de l’écoulement d’eau de mer ayant une fréquence de pic assez petite, nous avançons que les vibrations induites par vortex (VIV) sont la cause la plus plausible du mouvement rapide des branches. Par ailleurs, le fait que les coraux mous soient des espèces se nourrissant en filtrant l’eau de ses particules comestibles, nous faisons l’hypothèse que ces vibrations peuvent influencer leur taux d’alimentation. À l’aide d’un code maison d’éléments finis d’interaction fluide-structure, en plus de scripts codés en Python, nous avons simulé les trajectoires de particules sphériques autour d’un cylindre circulaire, puis calculé le taux de capture. Nous avons trouvé que, lors de la synchronisation de fréquence, les cylindres vibrants capturent jusqu’à 40% plus de particules que ceux fixés. Ainsi, les VIV augmenteraient probablement le taux d’alimentation des coraux mous et leur offriraient une meilleure nutrition.----------ABSTRACT Soft corals are flexible marine species that deform when exposed to a flow of water. Under the action of a wave surge, while the stem sways back and forth at the low frequency of the wave, a yet unreported motion takes place: the branches vibrate at high frequency, with small amplitude, and transverse to the water flow. The goal of this thesis is twofold: to explain the origin of these vibrations, and to find their impact on soft corals. Because the Glauert-den Hartog criterion is unfulfilled for an idealised coral branch, and since the peak frequencies of the seawater disturbance are too small, we consider vortex-induced vibrations (VIV) the only remaining probable cause of the observed rapid branch motion. Given that soft corals are sessile passive filter feeders that catch particles brought by currents, we hypothesise that these vibrations may affect their feeding rate. Using an in-house monolithic fluid-structure interaction (FSI) finite element solver along with a Python code, we simulated trajectories of spherical particles around a circular cylinder and calculated the capture rate. We found that vibrating cylinders capture up to 40% more particles than fixed ones at lock-in. Thence, VIV plausibly increase the rate of food capture and offer soft corals better nutrition