14238197
Data Semantics Revisited
The problem of data semantics is establishing and maintaining the correspondence between a data source and its intended subject matter. We review the long history of the problem in Databases, and contrast it with recent research on the Semantic Web. We then propose two new directions for research on the problem and sketch some open research questions.
15304659
Minimal Disclosure in Hierarchical Hippocratic Databases with Delegation
Hippocratic Databases have been proposed as a mechanism to guarantee the respect of privacy principles in data management. We argue that three major principles are missing from the proposed mechanism: hierarchies of purposes, delegation of tasks and authorizations (i.e. outsourcing), and the minimal disclosure of private information. 
 
In this paper, we propose a flexible framework for the negotiation of personal information among customers and (possibly virtual) enterprises based on user preferences when enterprises may adopt different processes to provide the same service. We use a goal-oriented approach to analyze the purposes of a Hippocratic system and derive a purpose and delegation hierarchy. Based on this hierarchy, effective algorithms are given to determine the minimum set of authorizations needed for a service. In this way, the minimal authorization table of a global business process can be automatically constructed from the collection of privacy policy tables associated with the collaborating enterprises. By using effective on-line algorithms, the derivation of such minimal information can also be done on-the-fly by the customer wishing to use the services of a virtual organization.
10751686
Experimenting with Linguistic Tools for Conceptual Modelling: Quality of the Models and Critical Features
This paper presents the results of three experiments designed to assess the extent to which a Natural-Language Processing (NLP) tool improves the quality of conceptual models, specifically object-oriented ones. Our main experimental hypothesis is that the quality of a domain class model is higher if its development is supported by a NLP system. The tool used for the experiment – named NL-OOPS – extracts classes and associations from a knowledge base realized by a deep semantic analysis of a sample text. In our experiments, we had groups working with and without the tool, and then compared and evaluated the final class models they produced. The results of the experiments give insights on the state of the art of NL-based Computer Aided Software Engineering (CASE) tools and allow identifying important guidelines to improve their performance, highlighting which of the linguistic tasks are more critical to effectively support conceptual modelling.
6610874
Detecting Conflicts of Interest
System vulnerabilities are often caused by the presence of conflicts within the organization where the system-to-be would eventually operate. In particular, conflicts of interest are very harmful since actors can exploit their positions/roles relative to the system for gaining personal advantage. Capturing and resolving such conflicts is a necessary condition for developing secure information systems. In this paper, we show how conflicts of interest can be formally detected during requirements analysis. This allows system designers to investigate the causes for which conflicts may occur in an organization. Thereby, they can better understand the organizational structure and so provide appropriate countermeasures to resolve or at least mitigate them
3088453
Reverse engineering goal models from legacy code
A reverse engineering process aims at reconstructing high-level abstractions from source code. This paper presents a novel reverse engineering methodology for recovering stakeholder goal models from both structured and unstructured legacy code. The methodology consists of the following major steps: 1) Refactoring source code by extracting methods based on comments; 2) Converting the refactored code into an abstract structured program through statechart refactoring and hammock graph construction; 3) Extracting a goal model from the structured program's abstract syntax tree; 4) Identifying nonfunctional requirements and derive soft goals based on the traceability between the code and the goal model. To illustrate this requirements recovery process, we refactor stakeholder goal models from two legacy software code bases: an unstructured Web-based email in PHP (SquirrelMail) and a structured email client system in Java (Columba).
3393049
Data Sharing in the Hyperion Peer Database System
This demo presents Hyperion, a prototype system that supports data sharing for a network of independent Peer Relational Database Management Systems (PDBMSs). The nodes of such a network are assumed to be autonomous PDBMSs that form acquaintances at run-time, and manage mapping tables to define value correspondences among different databases. They also use distributed Event-Condition-Action (ECA) rules to enable and coordinate data sharing. Peers perform local querying and update processing, and also propagate queries and updates to their acquainted peers. The demo illustrates the following key functionalities of Hyperion: (1) the use of (data level) mapping tables to infer new metadata as peers dynamically join the network, (2) the ability to answer queries using data in acquaintances, and (3) the ability to coordinate peers through update propagation.
35113903
Using semantic networks for data base management
This paper presents a semantic model of data bases. The model assumes the availability of a semantic network storing knowledge about a data base and a set of attributes for the data base. The use of the semantic net in generating a relational schema for the data base, in defining a set of semantic operators and in maintaining the data base consistent is then demonstrated.
14110385
Applying Tropos Methodology to a real case study: Complexity and Criticality Analysis
Currently in Requirements Engineering the attention is being focused more and more on the understanding of a problem by studying the existing organizational setting in which the system will operate. In this paper we present the application of the Tropos early requirements analysis to a real case study, the Ice Co. We introduce a new type of analysis for actor diagrams based on two different parameters, complexity and criticality, and we show the results we obtained during the case study.
393516
Filling the Gap between Requirements Engineering and Public Key/Trust Management Infrastructures
The last years have seen a major interest in designing and deploying trust management and public key infrastructures. Yet, it is still far from clear how one can pass from the organization and system requirements to the actual credentials and attribution of permissions in the PKI infrastructure. Our goal in this paper is filling this gap. We propose a formal framework for modeling and analyzing security and trust requirements, that extends the Tropos methodology for early requirements modeling. The key intuition that underlies our work is the identification of distinct roles for actors that manipulate resources, accomplish goals or execute tasks, and actors that own or permit usage of resources or goals. The paper also presents a simple case study and a PKI/trust management implementation.
1423082
Data Management for Peer-to-Peer Computing : A Vision
We motivate special database problems introduced by peer-to-peer computing and propose the Local Relational Model (LRM) to solve some of them. As well, we summarize a formalization of LRM, present an architecture for a prototype implementation, and discuss open research questions.
596050
Building knowledge base management systems

Abstract.Advanced applications in fields such as CAD, software engineering, real-time process control, corporate repositories and digital libraries require the construction, efficient access and management of large, shared knowledge bases. Such knowledge bases cannot be built using existing tools such as expert system shells, because these do not scale up, nor can they be built in terms of existing database technology, because such technology does not support the rich representational structure and inference mechanisms required for knowledge-based systems. This paper proposes a generic architecture for a knowledge base management system intended for such applications. The architecture assumes an object-oriented knowledge representation language with an assertional sublanguage used to express constraints and rules. It also provides for general-purpose deductive inference and special-purpose temporal reasoning. Results reported in the paper address several knowledge base management issues. For storage management, a new method is proposed for generating a logical schema for a given knowledge base. Query processing algorithms are offered for semantic and physical query optimization, along with an enhanced cost model for query cost estimation. On concurrency control, the paper describes a novel concurrency control policy which takes advantage of knowledge base structure and is shown to outperform two-phase locking for highly structured knowledge bases and update-intensive transactions. Finally, algorithms for compilation and efficient processing of constraints and rules during knowledge base operations are described. The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data. Based on these results, we conclude that knowledge base management systems which can accommodate large knowledge bases are feasible.
