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Usability is currently a key feature for developing quality systems. A system that satisfies all the functional requirements can be strongly rejected by end-users if it presents usability problems. End-users demand intuitive interfaces and an easy interaction in order to simplify their work. The first step in developing usable systems is to determine whether a system is or is not usable. To do this, there are several proposals for measuring the system usability. Most of these proposals are focused on the final system and require a large amount of resources to perform the evaluation (end-users, video cameras, questionnaires, etc.). Usability problems that are detected once the system has been developed involve a lot of reworking by the analyst since these changes can affect the analysis, design, and implementation phases. This paper proposes a method to minimize the resources needed for the evaluation and reworking of usability problems. We propose an early usability evaluation that is based on conceptual models. The analyst can measure the usability of attributes that depend on conceptual primitives. This evaluation can be automated taking as input the conceptual models that represent the system abstractly.

Extraction-Transformation-Loading (ETL) tools are pieces of software responsible for the extraction of data from several sources, their cleaning, customization and insertion into Data Warehouses (DWs). Complexity, usability and maintainability are the primary problems concerning ETL processes. To deal with these problems, in this paper we provide a dynamic approach for designing, modeling and realizing ETL processes. We propose a new architecture based on Unified Views Model (UVM) for ETL processes, in which Unified view layer is added between source data level and DWs level. The unified views model serves as the means to conform the structure and semantics of the source data to the ones of the data warehouses, and help designers understand and analyze the meaning, relationships and lineage of information. In order to guarantee the transparency access and the usability, two mapping methods are adopted between Unified view level and source data level as well as between DWs level and Unified view level. Based on this architecture, the method of constructing UVM and ETL operations among three levels is given. Then, we describe how to build the conceptual modeling for ETL processes based on UVM by using an extension of the Unified Modeling Language (UML). Finally, we present an ETL tool based on UVM (UVETL) with the goal of facilitating the design, modeling and realization of ETL processes, and give a case study to exemplify the benefits of our proposal.

Research Information Systems (RIS) play a critical role in the sharing of scientific information and provide researchers, professionals and decision makers with the required data for their activities. Existing RIS standards have proposed data models to represent the main entities for storage and exchange. These account for the needs of multiple stakeholders through a high flexibility based on a formal syntax and declared semantics, but for techno-historical reasons they assume the completeness of information within system boundaries. The distributed nature of research information across systems calls for a mechanism to link the local entities from the closed world of concrete RISs with other possibly underspecified entities exposed through other means, as for example, the Linked Open Data Web. By transformation of a relational model into an open graph model, differences between the two system paradigms are revealed. The main principles and techniques for exposing CERIF-driven relational data as linked data will be provided as a first step demonstrating effective RISs interconnection through the linked open data (LOD) Web.

In this paper, we identify some of the fundamental issues that must be addressed in designing a desktop Experiment Management System (EMS). We develop an abstraction of the set of activities performed by scientists throughout the course of an experimental study, and based on that abstraction we propose an EMS architecture that can support all such activities. The proposed EMS architecture is centered around the extensive use of conceptual schemas, which express the structure of information in experimental studies. Schemas are called to play new roles that are not usually found in traditional database systems. We provide a detailed exposition of these new roles and describe certain characteristics that the data model of the EMS must have in order for schemas expressed in it to successfully play these roles. Finally, we present the specifics of our own effort to develop an EMS, focusing on the main features of the data model of the system, which we have developed based on the needs of experiment management.

This paper identifies, explores and provides an approach to handling temporal information in object databases. It specifically involves the design and development of the Temporal Three Dimensional Information Space model that integrates time with objects. The model is based on a small number of simple temporal object constructs and provides a user with the basic primitives for temporal object definition, manipulation and retrieval. This research presents a step towards defining the concepts and techniques for incorporating time in object databases, and provides concrete experimental framework for demonstration thereof. Target Application environments include management and geographic information systems, database visualization and robotics.

Reference models for data analysis with data warehouses may consist of multidimensional reference models and analysis graphs. Multidimensional reference models are best-practice domain-specific data models for online analytical processing. Analysis graphs are reference models of analysis processes for event-driven data analysis. Small and medium-sized enterprises (SMEs) as well as large multinational companies may benefit from the use of reference models for data analysis. The availability of multidimensional reference models lowers the obstacles that inhibit SMEs from using business intelligence (BI) technology. Multinational companies may define multidimensional reference models for increased compliance among subsidiaries and departments. Furthermore, the definition of analysis graphs facilitates the handling of business events for both SMEs and large companies. Modelers may customize the chosen reference models, tailoring the models to the specific needs of the individual company or local subsidiary. Customizations may consist of additions, omissions, and modifications with respect to the reference model. In this paper, we propose a metamodel and customization approach for multidimensional reference models and analysis graphs. We specifically address the explicit modeling of key performance indicators as well as the definition of analysis situations and analysis graphs.

The focus of this paper is on the modeling of application and business process in Cooperative Information Systems. Such processes use several resources and services to achieve a common, global system goal. We integrate the proposed concepts into the framework of a formal object-oriented specification language (TROLL). The goals of our approach are to provide additional modeling support for business and application processes, to explain these processes in the underlying framework and to couple tightly the modeling of global processes and the modeling of structural aspects of the system.

This article presents a method for extracting a conceptual schema from a relational database. The method is based on an analysis of data manipulation statements in the code of an application using a relational DBMS. Attributes representing references between tables in the relational schema and possible keys are determined by an analysis of join conditions in queries and view definitions. Knowledge about which attributes link tables is used to investigate the database extension in a selective manner. When the keys cannot be unambiguously determined, possible solutions are generated by the system under guidance of the user. The approach makes it possible to efficiently construct a conceptual schema from only rudimentary information.

In information bases following semantic and object-oriented data models, logical names are used for the external identification of objects. Yet the naming schemes employed are not "natural" enough and several problems often arise: logical names can be ambiguous, excessively long, unrelated to or unable to follow the changes of the environment of the named object. In natural language, similar problems are resolved by the context within which words are used. An approach to introducing a notion of context in an information base is to provide structuring mechanisms for decomposing it into possibly overlapping parts. This paper focuses on developing a context mechanism for an information base and, in particular, exploiting this mechanism for naming purposes. Rules are developed for generating meaningful names for objects by taking their context into account. This context-based naming enhances name readability, resolves name ambiguities, saves a lot of redundant name substrings, and it localizes and thus facilitates consistency checking, query processing and update operations. In modeling, it supports systematic naming of objects, and thus enhances cooperation between the designers and the end-users in the sense that the contents of the information base are more understandable by both of them.

The World Wide Web serves as a leading vehicle for information dissemination by offering information services, such as product information, group interactions, or sales transactions. Three major factors affect the performance and reliability of information services for the Web, namely the distribution of information which has resulted from the globalization of information systems, the heterogeneity of information sources, and the sources' instability caused by autonomous evolution. This paper focuses on integrating existing information sources, available via the Web, in the delivery of information services. The primary objective of the paper is to provide mechanisms for structuring and maintaining domain models for Web applications. These mechanisms are based on conceptual modeling techniques, where concepts are being defined and refined within a metadata repository through the use of instantiation, specialization and attribution. Also, active databases techniques are exploited to provide robust mechanisms for maintaining a consistent domain model in a rapidly evolving environment, such as the Web. Therefore, the main contribution of the paper lies in the provision of an architecture for semi-automatic generation and maintenance of user-oriented, semantic-based domain models that describe distributed heterogeneous information sources.

Systems of technological networks (so-called Critical Infrastructures) might undergo strong perturbations leading to the reduction of their functionalities (crisis scenarios). Under perturbed conditions, infrastructures deliver their specific services in a range from a partial reduction up to a complete loss. Systems of complex technological networks (electrical, telecommunications, roads and railways, oil, gas and water pipelines etc.) are known to display large interdependences (a fault on one system spreads over the others); for this reason, it is relevant to devise simulators and decision support systems able to capture the complexity of such a "system of systems". The paper presents parts of the outcomes of a larger scientific project aiming at realizing a Decision Support System to predict the occurrence of undesired events and their consequences. In particular, we present a conceptual modeling approach consisting of a declarative language and a software implementation for the description and simulation of elements of Crisis Scenarios. The software application is conceived for risk managers, i.e. operators with a deep knowledge of critical infrastructure scenarios, but not necessarily with high-level IT or mathematical skill.

Ontology represents a data source at a higher level of abstraction. Extracting metadata from an autonomous data source and transforming it into source ontology is a tedious and error prone task because the metadata are either incomplete or not available. The essential metadata of a source can be extracted from its data. Our proposed methodology extracts the essential metadata from the data through reverse engineering. In addition, it comprises a set of transformation rules that transform extracted metadata into ontology. The transformation system R2O has been implemented. The evaluation of the proposed transformation is based on two factors, namely (a) correct identification and transformation of metadata and (b) preservation of information capacity. The research has been evaluated through experimental results and mathematical proof. The evaluation shows that the transformation is total and injective, and it preserves information capacity.

Conceptual modeling is a crucial software development activity for both Software Engineering and Knowledge Engineering. Each discipline, however, has developed its own techniques for conceptual modeling, and there is no agreement about a common set of techniques that can be used in both disciplines. This chapter will describe such techniques, paying special attention to the more recent and innovative ones, as well as to the concepts shared by the techniques used in the two disciplines.

The chapter will, therefore, outline the field of conceptual modeling within these two disciplines. Although the situation in the field is satisfactory, as can be inferred from the review conducted, there is still a lot of work to be done. Indeed, a series of shortcomings besetting the different techniques will be identified and an alternative perspective will be described, which points to a way of quieting such objections.

In order to meet the special requirements of future applications like multimedia information systems, we propose an object-relationship model(ORM) as a modeling tool for the formal specification and multimedia composition in time and space with respect to object-relationships. In particular, the proposed model is extensible to be easily enhanced for multimedia application needs. Also, we propose an object-relationship diagram(ORD) for graphically describing a multimedia database modeled by ORM. This diagram overcomes the shortcomings of the ER diagram. Furthermore, the diagram can be easily converted to a logical multimedia schema which is based on an object-oriented model.