Ebook: Databases and Information Systems VI

The Ninth International Baltic Conference on Databases and Information Systems (Baltic DB&IS'2010) took place on July 5–7 in Riga. This conference is continuing a series of successful biennial Baltic conferences on databases and information systems, which have been held in Trakai (1994), Tallin (1996, 2002, 2008), Riga (1998, 2004), and Vilnius (2000, 2006).

During this period, Baltic DB&IS conferences has become real international forums of high scientific criteria for academics and practitioners in the field of databases and advanced information systems (IS) as well as in related areas, such as semantic technologies, ontologies, advanced software engineering (SE) technologies for IS development, and IS and security.

Baltic DB&IS'2010 was organized by the Institute of Mathematics and Computer Science, University of Latvia, and the Faculty of Computing, University of Latvia, in co-operation with the Faculty of Computer Science and Information Technology, Riga Technical University.

The Programme Committee of Baltic DB&IS'2010 consisted of 35 members from 14 countries. 59 papers from 12 countries were submitted for the conference including 13 papers from 5 countries for Doctoral Consortium. Each conference paper was reviewed by three referees, as a rule, from different countries. As a result, 28 papers were accepted and presented at the conference. 27 revised and extended best papers are included in this volume.

The papers present original results concerning integration and security of IS, semantic technologies for IS, domain specific languages and tools for IS, SE with models and ontologies, model based data storages, and business IS.

We express our warmest thanks to all authors who contributed to the conference. Our special thanks to the invited speakers Prof. Hele-Mai Haav, Prof. Jürgen Ebert and Prof. Michal Smialek for sharing their knowledge in advanced systems development methods. We are grateful to members of the Programme Committee and the additional referees for a careful reviewing of submissions.

We would also like to thank all the organizing team and our sponsors, who have made this conference and publishing of this book possible. Our sincere gratitude to Conference Secretary Elina Kalnina for her immense technical work.

Last, but not least, we thank all participants who really made the conference.

October, 2010

Juris Borzovs, Conference Chair

Janis Barzdins, Programme Co-Chair

Marite Kirikova, Programme Co-Chair

Personalization is very important feature of any Location Base Service (LBS) as it improves its usability. The paper focuses a problem of development of personalized LBSs. In the paper, a novel approach based on ontology engineering is proposed to provide an intelligent (semantics-based) solution to personalization problem of LBS. The approach uses geospatial ontologies, ontology-based user profiling and multilingual output for personalization of services. The provided ontology-driven development framework for personalized LBS is evaluated by implementing the personalized reverse geo-coding service use case.

Model-based approaches in the UML/MOF technological space and ontology-based approaches in the OWL technological space both support conceptual modeling using different kinds of representation and analysis technologies. Both spaces provide services for accessing and manipulating models and ontologies, respectively.

This paper compares both spaces using to a mapping of models and ontologies based on a common model-theoretic semantics. Based on this mapping, different services for bridging the respective technological spaces are defined and discussed. Three different bridging strategies, namely Adaptation, transformation, and integration, are distinguished.

Rapid development of evolving software systems is highly associated with the ability to react quickly to changing user requirements. This paper presents a coherent set of technologies for simplifying the path from evolving requirements to code. The most important novel element on this path is a language defined at the level of requirements (understandable for non-IT experts) that is equipped with operational semantics. This means that it is possible to translate specifications written in this language, automatically into executable code. The language also allows for easy detection of changes in requirements. This detection can be propagated down to the code structure and appropriate code parts (these that are not automatically generated) indicated for rework. It will be demonstrated that the presented approach is effective and suitable for a wide range of problem domains as opposed to domain-specific approaches. This will be shown through a case study for a typical business software system, performed with a novel tool suite.

A promising approach, Object Management Group's (OMG) Model Driven Architecture (MDA), shifts the focus of software development from writing code to building models. It gives no guidelines on software implementation in terms of activities, phases, roles and responsibilities. Authors of this paper are offering an approach for enacting software development process with the help of process models. They are formalized with the help of Software Process Engineering Metamodel (SPEM), therefore the approach is called SPEM4MDA. The essence of approach is to use existing non-MDA process model formalized in SPEM notation, and with a help of another OMG initiative – Query/View/Transformation (QVT) – transforming it to MDA compliant process model.

This paper addresses the pattern matching problem for model transformation languages. Despite being an NP-complete problem, the pattern matching can be solved efficiently in typical areas of application. Prediction of actual cardinalities of model elements is the key to sufficient efficiency. The existing approaches aquire the actual cardinalities using complex run-time model analysis or using analysis of metamodel where the required information is poorly supplied. In the paper we show how the deeper understanding of domain which is targeted by model transformation language can dramatically reduce the complexity of pattern matching implementation. We propose a simple pattern matching algorithm for model transformation MOLA which is efficient for tasks related to the model driven software development. Additionaly a metamodel annotation mechanism is proposed. It refines the existing means of metamodelling by adding new classes of cardinalites. They make more efficient the pattern matching algorithms which do not use the complex run-time analysis.

The Transformation-Driven Architecture, TDA, is an approach for creating systems and tools. Can the UNDO/REDO functionality be easily (implicitly) introduced to the tools built upon TDA? The paper explains that this can be done at the level of TDA kernel in a universal way. We present the basic UNDO/REDO functionality as well as some its extensions.

Several metamodels are often introduced when looking at the same fragment of the real world from different points of view. This process involves multiplying data to be instances of those metamodels thus enforcing the redundancy and complicating the maintenance. In this paper, a mechanism for defining (read only) views on arbitrary metamodels is presented. Having the mechanism, a user is allowed to work with the view metamodel and its instances by the means of a model transformation language while at the same time only instances of the base metamodel are kept physically in the memory. Thus, the proposed view definition mechanism does not introduce a redundancy of data. Also, the basic ideas of compiling model transformation programs from the view metamodel to the base metamodel are outlined here.

Models in general and class diagrams as defined by the UML in particular play an important role throughout all steps of modern software development. However, the UML contains several modeling concepts which are not defined precisely and hence are used either rarely or in varying ways and with different semantics. In this article, an extension of n-ary associations as one of those concepts is presented including their refinement by specialization, subsetting and redefinition. DHHTGraphs are introduced as one realization of this extension treating associations and links as first-class objects. In particular, a metamodel and a possible implementation realizing association end refinement by association specialization are presented.

Metamodeling and Ontological modeling are two popular modeling approaches with their own technical tools, supporters and opponents. As a result of symbiosis of the two mentioned methodologies new metamodel is created and implemented in multilevel in-memory data repository. Repository implementation details are shown and several test- and use cases are analyzed.

We present a RDB2OWL mapping specification language that is aimed at presenting RDB-to-RDF/OWL mappings possibly involving advanced correspondences between the database and ontology in a human comprehensible way. The RDB2OWL mappings can be regarded as documentation of the database-to-ontology relation. The RDB2OWL language reuses the OWL ontology structure as a backbone for mapping specification by placing the database link information into the annotations for ontology classes and properties. It features reuse of database table key information, user defined and table functions, as well as multiclass conceptualization that is essential for keeping the mapping compact in case of creating a conceptual partitioning of large database tables. We report also on initial implementation experience for a subset of RDB2OWL constructs.

This paper presents a statistical phrase-based machine translation system which is enriched with semantic data coming from a spatial ontology. Paper presents the spatial ontology, how it is integrated in statistical machine translation system using factored models and how it is being evaluated using both automatic and human evaluation. Spatial information is added as a factor in both translation and language models. SOLIM spatial ontology language is used to implement ontology and to infer necessary knowledge for training statistical machine translation system. The machine translation system is based on Moses toolkit.

Practitioners view on modeling with domain specific languages is presented in this paper. It is shown, that unlike general-purpose modeling languages, domain specific languages provide means for concise representation of semantics of the particular business domain, enabling development of consistent and expressive business process models. Resulting models can be used not only as specifications for information systems, but also for generation of implementation artifacts, creating documentation, testing and for other purposes. Thus one of the most principal goals of model driven architecture – the development of model-based information system – is achieved.

The article discusses the solution of common business process design-time problems using YAWL. The approach proposed by the authors is based on the creation of business process in the YAWL environment in order to simulate the process model which could resolve some of the design-time problems as well as provide hints to correct initial process. Simulation is based on transformation to colored Petri net – the net is then simulated to identify problems such as possible infinite loops, bottlenecks, process waits and others. The article also describes technique to acquire the primitive description of process from the YAWL workflow. The primitive description is represented as oriented graph and is used to transform the YAWL workflow to another hierarchic language, in this case BPEL.

For the purposes of tool development, computer languages are usually described using context-free grammars with annotations such as semantic actions or pretty-printing instructions. These specifications are processed by generators which automatically build software, e.g., parsers, pretty-printers and editing support.

In many cases the annotations make grammars unreadable, and when generating code for several tools supporting the same language, one usually needs to duplicate the grammar in order to provide different annotations for different generators.

We present an approach to describing languages which improves readability of grammars and reduces the duplication. To achieve this we use Aspect-Oriented Programming principles. This approach has been implemented in an open-source tool named GRAMMATIC. We show how it can be used to generate pretty-printers and syntax highlighters.

Project management is a complex process regulated by project management methodologies, standards and other requirements. Different project management information systems are used to support this process. To ensure that the project management information system delivers expected results, it should be configured according requirements of the chosen methodology. In this configuration process XML is used for standardize definition and description of project management requirements. This paper describes structure and application of the aforementioned XML schema, which is referred as XML schema for Configuration of Project Management information systems (XCPM). XCPM is based on a comprehensive project management concept model. Each entity from the concept model can be described using the XCPM schema. The paper also surveys approaches for project management information system configuration. Configuration of the change control process in the project management information system is described to illustrate application of the XCPM.

Selection of appropriate web services is an important step in development of composite applications. Quality of Service (QoS) data characterizing nonfunctional properties of candidate web services are usually used in web service selection. However, functional characteristics, which are difficult to measure, are equally important. Quantitative evaluation of functional characteristics is possible in the case of development of composite decision-making applications. This paper elaborates a web service selection method, which accounts for both functional and nonfunctional characteristics of candidate web services. The functional characteristics are evaluated according to decision-making results yielded by the composite application. A linear programming model is used as the web service selection method and the cost of developing and operating the composite application is used as a selection metric. Application of the proposed web service selection method is demonstrated by developing a composite application for a vehicle routing problem, where web services are required to provide spatial data necessary for the decision-making algorithm. Experimental results show that accounting for functional characteristics substantially affects web service selection results.

The paper describes principles, architecture and design of a general solution for business process management systems integration with complex event processing (CEP) engines. As CEP query standards are still in early development we define a general abstract CEP Query Model and corresponding distributed infrastructure: CEP Network to abstract from specific CEP engines. We propose integration between BPEL Engines and CEP Network using intermediary bidirectional CEP Service. Key part of the solution is to represent CEP Network queries as WSRF resources. Events from CEP Network are received using WS-Notification. This approach allows using standard BPEL and does not require any changes or extensions in BPEL Engine and designing tool. We compare the proposed approach with some existing alternatives. We present a prototype which implements key components of the proposed solution and provides integration between an open source CEP Engine Esper and BPEL Apache ODE engine.

The question of value is being increasingly discussed in various disciplines in recent years. Value-Based Management and Value-Based Software Engineering (VBSE) have emerged as promising attempts for employing the value concept in generating information systems which satisfy the needs of all stakeholders. We analyzed several package software implementation projects for assessing applicability of value based approach and found that seldom sufficient value for stakeholders has been produced. VBSE might have helped to achieve better results, although the theory itself is not fully matured yet. We found that stressing the role of agency in value analysis by utilizing the life metaphor can significantly enhance the explanatory power of the theory. This facilitates understanding of many advanced qualities of systems and development of theoretical framework for transforming the enterprise together with its information system. Our analysis will be concluded with suggestions for conducting projects similar to those analyzed in this article