The methodological soundness of requirements engineering papers: a conceptual framework and two case studies

This paper was triggered by concerns about the methodological soundness of many RE papers. We present a conceptual framework that distinguishes design papers from research papers, and show that in this framework, what is called a research paper in RE is often a design paper. We then present and motivate two lists of evaluation criteria, one for research papers and one for design papers. We apply both of these lists to two samples drawn from the set of all submissions to the RE’03 conference. Analysis of these two samples shows that most submissions of the RE’03 conference are design papers, not research papers, and that most design papers present a solution to a problem but neither validate this solution nor investigate the problems that can be solved by this solution. We conclude with a discussion of the soundness of our results and of the possible impact on RE research and practice.     

Development of a biomimetic miniature robotic crawler

The paper presents the development of segmented artificial crawlers endowed with passive hook-shaped frictional microstructures. The goal is to find design rules for fabricating biomimetic, adaptable and mobile machines mimicking segmented animals with hydrostatic skeleton, and intended to move effectively along unstructured substrates. The paper describes the mechanical model, the design and the fabrication of a SMA-actuated segmented microrobot, whose locomotion is inspired by the peristaltic motion of Annelids, and in particular of earthworms (Lumbricus Terrestris). Experimental locomotion performance are compared with theoretical performance predicted by a purposely developed friction model -taking into account design parameters such as number of segments, body mass, special friction enhancement appendixes—and with locomotion performance of real earthworms as presented in literature. Experiments indicate that the maximum speed of the crawler prototype is 2.5 mm/s, and that 3-segment crawlers have almost the same velocity as earthworms having the same weight (and about 330% their length), whereas 4-segment crawlers have the same velocity, expressed as body lengths/s, as earthworms with the same mass (and about 270% their length). Arianna Menciassi (MS, 1995; PhD, 1999) joined the CRIM Lab of the Scuola Superiore Sant’Anna (Pisa, Italy) as a Ph.D. student in Bioengineering with a research program on the micromanipulation of mechanical and biological micro-objects. The main results of the activity on micromanipulation were presented at the IEEE International Conference on Robotics & Automation (May 2001, Seoul) in a paper titled “Force Feedback-based Microinstrument for Measuring Tissue Properties and Pulse in Microsurgery”, which won the “ICRA2001 Best Manipulation Paper Award”. In the year 2000, she was offered a position of Assistant Professor in Biomedical Robotics at the Scuola Superiore Sant’Anna and in June 2006 she obtained a promotion to Associate Professor. Her main research interests are in the field of biomedical microrobotics, biomimetics, microfabrication technologies, micromechatronics and microsystem technologies. She is working on several European projects and international projects for the development of minimally invasive instrumentation for medical applications and for the exploitation of micro- and nano-technologies in the medical field. Samuele Gorini received his Laurea Degree in Mechanical Engineering (with honors) from the University of Pisa, Italy, in 2001. In 2005 he obtained the Ph.D. in Microsystem Engineering with a thesis on locomotion methods and systems for miniaturised endoscopic devices. Since 2000, he has been working at the CRIM Lab of the Scuola Superiore Sant’Anna in Pisa, Italy. His research interests are in the field of biomedical robotics with a special focus on actuation technologies. Starting from the year 2004 he has been president of Era Endoscopy S.r.l., a start-up company of Scuola Superiore Sant’Anna developing novel devices for endoscopy. Dino Accoto (MS 1998, PhD 2002) is Assistant Professor of Biomedical Engineering at Scuola Sant’Anna (Pisa, Italy). He received the Laurea degree in Mechanical Engineering from the University of Pisa (cum laude) in 1998, the diploma in Engineering from the Scuola Sant’Anna (cum laude) in 1999 and the PhD degree from the Scuola Sant’Anna in 2002. From October 2001 to September 2002 he has been visiting scholar at the RPL-Lab, Stanford University (Ca, USA). Since 2004 he cooperates with the Biomedical Robotics & EMC Lab at Campus Bio-Medico University in Rome. His main research field is the modelling and development of small electromechanical systems, with a special attention to multi-physics and multi-domain approaches. The research, often inspired by the analysis of natural mechanisms, has been mainly applied to hybridizing microtechnologies, including microfluidics, and robotics. He has co-authored more than 30 papers, appeared in international journals and conference proceedings. Paolo Dario received his Dr. Eng. Degree in Mechanical Engineering from the University of Pisa, Italy, in 1977. He is currently a Professor of Biomedical Robotics at the Scuola Superiore Sant’Anna in Pisa.. He also teaches courses at the School of Engineering of the University of Pisa and at the Campus Biomedico University in Rome. He has been Visiting Professor at Brown University, Providence, RI, USA, at the Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland, at Waseda University, Tokyo, Japan, at the College de France, Paris, and at the Ecole Normale Superieure de Cachan, France. He was the founder of the ARTS (Advanced Robotics Technologies and Systems) Laboratory and is currently the Co-ordinator of the CRIM (Center for the Research in Microengineering) Laboratory of the Scuola Superiore Sant’Anna, where he supervises a team of about 70 researchers and Ph.D. students. His main research interests are in the fields of medical robotics, bio-robotics, mechatronics and micro/nanoengineering, and specifically in sensors and actuators for the above applications, and in robotics for rehabilitation. He is the coordinator of many national and European projects, the editor of two books on the subject of robotics, and the author of more than 200 scientific papers (75 on ISI journals). He is Editor-in-Chief, Associate Editor and member of the Editorial Board of many international journals. Prof. Dario has served as President of the IEEE Robotics and Automation Society in the years 2002–2003. He has been the General Chair of the IEEE RAS-EMBS BioRob’06 Conference and he is the General Co-Chair of ICRA 2007 Conference. Prof. Dario is an IEEE Fellow, a Fellow of the European Society on Medical and Biological Engineering, and a recipient of many honors and awards, such as the Joseph Engelberger Award. He is also a member of the Board of the International Foundation of Robotics Research (IFRR).     

A system for pattern recognition and pattern summarization in multi-band satellite images

A new system (C.T.R.F.’s LSGENSYS—Linguistic Summary Generation System) that has been developed for pattern recognition and summarization of patterns in multiband (RGB) satellite images is described in this paper. The system design is described in some detail. The system has been tested successfully with SPOT MS and LANDSAT images. It extracts, analyzes, and summarizes patterns such as land, island, water body, river, fire, and urban settlements from these images. The results are presented by allowing the system to automatically classify and interpret these images. Some elements of supervised classification are also introduced, and a comparison is made between the results in each case. The text was submitted by the author in English. Hema Nair. Date of Birth: November 21, 1965. Education: Hema Nair received her Bachelors Degree in Electrical Engineering from Government Engineering College, University of Calicut, Kerala, India, in 1986. She received her Masters Degree in Electrical Engineering from National University of Singapore in 1993. Ms. Nair received her Masters Degree in Computer Science from Clark Atlanta University, Atlanta, United States, in 1996. Membership: A member of IEEE (USA) and ACM (USA) since 1997. A member of the Institution of Engineers (India) since 1988. Awards: 1. Ms. Nair’s Masters Degree research in the United States was funded by a US Army Grant. 2. One of Ms. Nair’s publications was cited with the Abstract in NASA’s Scientific and Technical Information Program Reports of 2006. Work Experience: 1. Ms. Nair was employed as Senior Technical Associate II at AT and T, New Jersey, United States, between 1996 and 2000. Her work included research and leading AT&T Projects as Project Leader. 2. She also served as Faculty in Apple Information Technology, Ltd, Bangalore, India, between 1987 and 1990. 3. Ms. Nair worked on contract as a lecturer in Multimedia University, Malaysia, between 2001 and 2005. 4. Since 2005, she has been working as a Researcher at C.T.R.F., a research and education foundation in India. Research Interests: Ms. Nair’s research interests include Image Analysis, Pattern Recognition, Databases, Artificial Intelligence, and Data Mining. Publications: Ms. Nair has published several papers internationally. These include 7 International Conference Papers and 4 International Journals. Reviewer for LASTED International Conference 2004.     

Slicing concurrent Java programs using Indus and Kaveri

Program slicing is a program analysis and transformation technique that has been successfully used in a wide range of applications including program comprehension, debugging, maintenance, testing, and verification. However, there are only few fully featured implementations of program slicing that are available for industrial applications or academic research. In particular, very little tool support exists for slicing programs written in modern object-oriented languages such as Java, C#, or C++. In this paper, we present Indus—a robust framework for analyzing and slicing concurrent Java programs, and Kaveri—a feature-rich Eclipse-based GUI front end for Indus slicing. For Indus, we describe the underlying tool architecture, analysis components, and program dependence capabilities required for slicing. In addition, we present a collection of advanced features useful for effective slicing of Java programs including calling-context sensitive slicing, scoped slicing, control slicing, and chopping. For Kaveri, we discuss the design goals and basic capabilities of the graphical facilities integrated into a Java development environment to present the slicing information. This paper is an extended version of a tool demonstration paper presented at the International Conference on Fundamental Aspects of Software Engineering (FASE 2005). Thus, the paper highlights tool capabilities and engineering issues and refers the reader to other papers for technical details. This work was supported in part by the US Army Research Office (DAAD190110564), by DARPA/IXO’s PCES program (AFRL Contract F33615-00-C-3044), by NSF (CCR-0306607) by Lockheed Martin, and and by Intel Corporation.     

An evaluation study of a digital library of ideas: Workflow Model and classroom use

The Department of Design Manufacturing and Engineering Management at the University of Strathclyde, Glasgow, UK, has been developing a digital library to support design engineering student learning through the Digital Libraries for Global Distributed Innovative Design Education and Teamwork project (, December, 2007). Previous related studies have observed and analysed how students search for, store, structure and share design engineering information (Grierson et al. in paper presented at the Network Learning Conference, pp. 572–579, 2004; Nicol et al. in Open Learning 20(1):31–49, 2005) and these studies have identified the need for the design and development of a digital library with two system components, which best suit the design process: (i) an informal shared workspace; the ‘LauLima’ Learning Environment and (ii) a repository of more formal searchable and browsable design information; the ‘LauLima’ Digital Library (McGill et al. in Br. J. Educ. Technol. 36(4):629–642, 2005). This paper focuses on the Workflow Model developed to populate the digital library and presents findings from early use of the digital library by students and staff.     

False Requirements Express Real Needs

Requirements Engineering for airing readers’ views on requirements engineering research and practice. Contributions that describe results, experiences, biases and research agendas in requirements engineering are particularly welcome. ‘Viewpoints’ is an opportunity for presenting technical correspondence or subjective arguments. So, whether you are a student, teacher, researcher or practitioner, get on your soapbox today and let us know what’s on your mind . . . Please submit contributions electronically to Viewpoints Editor, Bashar Nuseibeh (ban@doc.ic.ac.uk). Contributions less than 2000 words in length are preferred.     

Linking business and requirements engineering: is solution planning a missing activity in software product companies?

A strong link between strategy and product development is important, since companies need to select requirements for forthcoming releases. However, in practice, connecting requirements engineering (RE) and business planning is far from trivial. This paper describes the lessons learned from four software product companies that have recognized the need for more business-oriented long-term planning. The study was conducted using the action research approach. We identified five practices that seem to strengthen the link between business decisions and RE. These are (1) explicating the planning levels and time horizons; (2) separating the planning of products’ business goals from R&D resource allocation; (3) planning open-endedly with a pre-defined rhythm; (4) emphasizing whole-product thinking; and (5) making solution planning visible. To support whole-product thinking and solution planning, we suggest that companies create solution concepts. The purpose of the solution concept is to provide a big picture of the solution and guide RE activities.     

Industry needs and research directions in requirements engineering for embedded systems

The industry has a strong demand for sophisticated requirements engineering (RE) methods in order to manage the high complexity of requirements specifications for software-intensive embedded systems and ensure a high requirements quality. RE methods and techniques proposed by research are only slowly adopted by the industry. An important step to improve the adoption of novel RE approaches is to gain a detailed understanding of the needs, expectations, and constraints that RE approaches must satisfy. We have conducted an industrial study to gain an in-depth understanding of practitioners’ needs concerning RE research and method development. The study involved qualitative interviews as well as quantitative data collection by means of questionnaires. We report on the main results of our study related to five aspects of RE approaches: the use of requirements models, the support for high system complexity, quality assurance for requirements, the transition between RE and architecture design, and the interrelation of RE and safety engineering. Based on the results of the study, we draw conclusions for future RE research.     

Policy development and access to wireless technologies for people with disabilities: results of policy Delphi research

This paper discusses the relationship between policy research and policy change, and it provides examples of the policy research outcomes informed by the Rehabilitation Engineering Research Center on Mobile Wireless Technologies for People with Disabilities’ (Wireless RERC) policy research process. In 2005 and 2006, the center conducted empirical research, using the policy Delphi polling methodology, to probe key stakeholders’ opinions on the most significant issues surrounding the adoption and use of wireless communication and information technologies by people with disabilities. Drawing on the results of three rounds of polling, the Wireless RERC developed a set of policy options, and “fine-tuned” them using participating stakeholders from the disability community, wireless industry, and policymakers.     

Modeling semantics in composite Web service requests by utility elicitation

When meeting the challenges in automatic and semi-automatic Web service composition, capturing the user’s service demand and preferences is as important as knowing what the services can do. This paper discusses the idea of semantic service requests for composite services, and presents a multi-attribute utility theory (MAUT) based model of composite service requests. Service requests are modeled as user preferences and constraints. Two preference structures, additive independence and generalized additive independence, are utilized in calculating the expected utilities of service composition outcomes. The model is also based on an iterative and incremental scheme meant to better capture requirements in accordance with service consumers’ needs. OWL-S markup vocabularies and associated inference mechanism are used as a means to bring semantics to service requests. Ontology conceptualizations and language constructs are added to OWL-S as uniform representations of possible aspects of the requests. This model of semantics in service requests enables unambiguous understanding of the service needs and more precise generation of the desired compositions. An application scenario is presented to illustrate how the proposed model can be applied in the real business world. Qianhui Althea Liang received her Ph.D from the Department of Electrical and Computer Engineering, University of Florida in 2004. While pursuing her Ph.D, she was a member of Database Systems Research and Development Center at the University of Florida. She received both her bachelor’s and master’s from the Department of Computer Science and Engineering, Zhejiang University, China. She joined the School of Information Systems at Singapore Management University, Singapore, as an assistant professor in 2005. Her major research interests are service composition, dynamic service discovery, multimedia Web services, and applied artificial intelligence. Jen-Yao Chung received the M.S. and Ph.D degrees in computer science from the University of Illinois at Urbana-Champaign. Currently, he is the senior manager for Engineering and Technology Services Innovation, where he was responsible for identifying and creating emergent solutions. He was Chief Technology Officer for IBM Global Electronics Industry. Before that, he was program director for IBM Institute for Advanced Commerce Technology office. He is the co-founder of IEEE technical committee on e-Commerce (TCEC). He has served as general chair and program chair for many international conferences, most recently he served as the steering committee chair for the IEEE International Conference on e-Commerce Technology (CEC06) and general chair for the IEEE International Conference on e-Business Engineering (ICEBE06). He has authored or coauthored over 150 technical papers in published journals or conference proceedings. He is a senior member of the IEEE and a member of ACM. Miller is founding Dean of the School of Information Systems (SIS) at Singapore Management University, and also serves as Practice Professor of Information Systems. Since 2003, he has led efforts to launch and establish the undergraduate, graduate and professional programs of the SIS. Immediately prior to joining SMU, Dr. Miller served as Chief Architect Executive for the Business Consulting Services unit of IBM Global Services in Asia Pacific. He held prior industry appointments with Fujitsu Network Systems, and with RWD Technologies. Dr. Miller started his professional career as an Assistant Professor at Carnegie Mellon University, conducting research and teaching related to Computer-Integrated Manufacturing and Robotics applications and impacts. He has a Bachelors of Engineering Degree in Systems Engineering (Magna Cum Laude) from the University of Pennsylvania and a Masters of Science in Statistics and a Ph.D in Engineering and Public Policy from Carnegie Mellon University.     

A user-friendly tool for image analysis

A new graphical tool (Multimedia University’s RSIMANA—Remote-Sensing Image Analyzer) developed for image analysis is described in this paper. MATLAB and ENVI are some of the commercially available tools in the market that aid in image processing and analysis. But their current versions are of limited assistance in image analysis; for example, MATLAB can extract the area of irregular objects and patterns in images, but not their length. ENVI is more focused on image processing than on image analysis functions. Other commercially available tools are also prohibitively expensive. This indicates the need to develop a userfriendly graphical tool that meets research objectives in the educational environment. The text was submitted by the author in English. Hema Nair. Born 1965. Educational qualifications: B.Tech. (Electrical Engineering) from Government Engineering College affiliated to University of Calicut, Kerala State, India, 1986; MSc (Electrical Engineering) from National University of Singapore, 1993; MSc (Computer Science) from Clark Atlanta University, USA, 1996. Previous employment: Researcher and Project Leader in AT & T, New Jersey, USA, for about 5 years. Also worked in Bangalore, India, before that in Apple Information Technology Ltd. as Teaching Faculty. Current employment: lecturer, Faculty of Engineering and Technology, Multimedia University, Malaysia. Current research: the final stages of her PhD in Computer Science at Multimedia University. Scientific interests are image analysis, pattern recognition, databases, AI, data mining. Member of IEEE (USA) since 1997, Professional Member of ACM (USA) since 1997, Member of Institution of Engineers (India) since 1986. Reviewer for IASTED International Conference 2004. Current PhD project entitled “Pattern Extraction and Concept Clustering in Linguistic Terms from Mined Images” is funded by an Intensive Research in Priority Area (IRPA) grant from Government of Malaysia. Research for MSc in Computer Science from USA was funded by a research grant from the US Army. Author of three International Conference papers accepted in Portugal, Belgium, and India.     

A methodology for the selection of requirements engineering techniques

The complexity of software projects as well as the multidisciplinary nature of requirements engineering (RE) requires developers to carefully select RE techniques and practices during software development. Nevertheless, the selection of RE techniques is usually based on personal preference or existing company practice rather than on characteristics of the project at hand. Furthermore, there is a lack of guidance on which techniques are suitable for a certain project context. So far, only a limited amount of research has been done regarding the selection of RE techniques based on the attributes of the project under development. The few approaches that currently exist for the selection of RE techniques provide only little guidance for the actual selection process. We believe that the evaluation of RE techniques in the context of an application domain and a specific project is of great importance. This paper describes a Methodology for Requirements Engineering Techniques Selection (MRETS) as an approach that helps requirements engineers select suitable RE techniques for the project at hand. The MRETS has three aspects: Firstly, it aids requirements engineers in establishing a link between the attributes of the project and the attributes of RE techniques. Secondly, based on the evaluation schema proposed in our research, MRETS provides an opportunity to analyze RE techniques in detail using clustering. Thirdly, the objective function used in our approach provides an effective decision support mechanism for the selection of RE techniques. This paper makes contributions to RE techniques analysis, the application of RE techniques in practice, RE research, and software engineering in general. The application of the proposed methodology to an industrial project provides preliminary information on the effectiveness of MRETS for the selection of RE techniques.     

Direct and indirect gradient control for static optimisation

1 Introduction Chemical process plants are always controlled in dif- ferent layers. For example, several local control layers are designed to maintain local controlled variables at the desired operating point whilst a plantwide optimi- sation layer is responsible for adjusting the setpoint to the local layers according to di?erent situations (dis- turbances). Traditionally, these two layers are designed separately for di?erent (economic and dynamic) objec- tives although they need working toge…     

Mining changing regions from access-constrained snapshots: a cluster-embedded decision tree approach

Change detection on spatial data is important in many applications, such as environmental monitoring. Given a set of snapshots of spatial objects at various temporal instants, a user may want to derive the changing regions between any two snapshots. Most of the existing methods have to use at least one of the original data sets to detect changing regions. However, in some important applications, due to data access constraints such as privacy concerns and limited data online availability, original data may not be available for change analysis. In this paper, we tackle the problem by proposing a simple yet effective model-based approach. In the model construction phase, data snapshots are summarized using the novel cluster-embedded decision trees as concise models. Once the models are built, the original data snapshots will not be accessed anymore. In the change detection phase, to mine changing regions between any two instants, we compare the two corresponding cluster-embedded decision trees. Our systematic experimental results on both real and synthetic data sets show that our approach can detect changes accurately and effectively. Irene Pekerskaya’s and Jian Pei’s research is supported partly by National Sciences and Engineering Research Council of Canada and National Science Foundation of the US, and a President’s Research Grant and an Endowed Research Fellowship Award at Simon Fraser University. Ke Wang’s research is supported partly by Natural Sciences and Engineering Research Council of Canada. All opinions, findings, conclusions and recommendations in this paper are those of the authors and do not necessarily reflect the views of the funding agencies.     

Music composition by interaction between human and computer

This paper aims at constructing a music composition system that composes music by the interaction between human and a computer. Even users without special musical knowledge can compose 16-bar musical works with one melody part and some backing parts using this system. The interactive Genetic Algorithm is introduced to music composition so that users’ feeling toward music is reflected in the composed music. One chromosome corresponds to 4-bar musical work information. Users participate in music composition by evaluating composed works after GA operators such as crossover, mutation, virus infection are applied to chromosomes based on the evaluation results. From the experimental results, it is found that the users’ evaluation values become high over the progress of generations. That is, the system can compose 16-bar musical works reflecting users’ feeling. Muneyuki Unehara: He received his M.S. in Engineering in 2002 from Institute of Science and Engineering, University of Tsukuba. Currently, he is a Ph.D. candidate of Graduate School of Systems and Information Engineering, University of Tsukuba. His research interests include the construction of intelligent systems by considering soft computing techniques and human interface. Takehisa Onisawa, Ph.D.: He received Dr.Eng. in Systems Science in 1986 from Tokyo Institute of Technology. Currently, he is a Professor in the Graduate School of Systems and Information Engineering, University of Tsukuba. His research interests include applications of soft computing techniques to human centered systems thinking. He is a member of IEEE and IFSA.     

PnP: sequential, external memory, and parallel iceberg cube computation

We present “Pipe ’n Prune” (PnP), a new hybrid method for iceberg-cube query computation. The novelty of our method is that it achieves a tight integration of top-down piping for data aggregation with bottom-up a priori data pruning. A particular strength of PnP is that it is efficient for all of the following scenarios: (1) Sequential iceberg-cube queries, (2) External memory iceberg-cube queries, and (3) Parallel iceberg-cube queries on shared-nothing PC clusters with multiple disks. We performed an extensive performance analysis of PnP for the above scenarios with the following main results: In the first scenario PnP performs very well for both dense and sparse data sets, providing an interesting alternative to BUC and Star-Cubing. In the second scenario PnP shows a surprisingly efficient handling of disk I/O, with an external memory running time that is less than twice the running time for full in-memory computation of the same iceberg-cube query. In the third scenario PnP scales very well, providing near linear speedup for a larger number of processors and thereby solving the scalability problem observed for the parallel iceberg-cubes proposed by Ng et al. Research partially supported by the Natural Sciences and Engineering Research Council of Canada. A preliminary version of this work appeared in the International Conference on Data Engineering (ICDE’05).     

Early Estimation of Users’ Perception of Software Quality

This paper presents a methodology for estimating users’ opinion of the quality of a software product. Users’ opinion changes with time as they progressively become more acquainted with the software product. In this paper, we study the dynamics of users’ opinion and offer a method for assessing users’ final perception, based on measurements in the early stages of product release. The paper also presents methods for collecting users’ opinion and from the derived data, shows how their initial belief state for the quality of the product is formed. It adapts aspects of Belief Revision theory in order to present a way of estimating users’ opinion, subsequently formed after their opinion revisions. This estimation is achieved by using the initial measurements and without having to conduct surveys frequently. It reports the correlation that users tend to infer among quality characteristics and represents this correlation through a determination of a set of constraints between the scores of each quality characteristic. Finally, this paper presents a fast and automated way of forming users’ new belief state for the quality of a product after examining their opinion revisions. Dimitris Stavrinoudis received his degree in Computer Engineering from Patras University and is a Ph.D. student of Computer Engineering and Informatics Department. He worked as a senior computer engineer and researcher at the R.A. Computer Technology Institute. He has participated in research and development projects in the areas of software engineering, databases and educational technologies. Currently, he works at the Hellenic Open University. His research interests include software quality, software metrics and measurements. Michalis Xenos received his degree and Ph.D. in Computer Engineering from Patras University. He is a Lecturer in the Informatics Department of the School of Sciences and Technology of the Hellenic Open University. He also works as a researcher in the Computer Technology Institute of Patras and has participated in over 15 research and development projects in the areas of software engineering and IT development management. His research interests include, inter alia, Software Engineering and Educational Technologies. He is the author of 6 books in Greek and over 30 papers in international journals and conferences. Pavlos Peppas received his B.Eng. in Computer Engineering from Patras University (1988), and his Ph.D. in Computer Science from Sydney University (1994). He joined Macquarie University, Sydney, as a lecturer in September 1993, and was promoted to a senior lecturer in October 1998. In January 2000, he took up an appointment at Intrasoft, Athens, where he worked as a senior specialist in the Data Warehousing department. He joint Athens Information Technology in February 2003 as a senior researcher, and since November 2003 he is an associate professor at the Dept of Business Administration at the University of Patras. He also holds an adjunct associate professorship at the School of Computer Science and Engineering at the University of New South Wales. His research interests lie primarily within the area of Artificial Intelligence, and more specifically in logic-based approaches to Knowledge Representation and Reasoning with application in robotics, software engineering, organizational knowledge management, and the semantic web. Dimitris Christodoulakis received his degree in Mathematics from the University of Athens and his Ph.D. in Informatics from the University of Bonn. He was a researcher at the National Informatics Centre of Germany. He is a Professor and Vice President of Computer Engineering and Informatics Department of Patras University. Scientific Coordinator in many research and development projects in the followings sections: Knowledge and Data Base Systems, Very large volume information storage, Hypertext, Natural Language Technology for Modern Greek. Author and co-author in many articles published in international conferences. Editor in proceedings of conventions. Responsible for proofing tools development for Microsoft Corp. He is Vice Director in the Research Academic Computer Technology Institute (RACTI).     

Special section on testing and security of Web systems

This special section is devoted to a selection of papers that have been originally published in the Proceedings of the International Workshop on Web Quality, Verification and Validation (WQVV) held in Como, Italy, in July 2007. The workshop was part of the Seventh International Conference on Web Engineering (ICWE 2007). These papers investigate different issues of two fundamental “aspects” of quality and dependability of modern Web systems: testing and security. The main contribution of this special section consists in trying to bring the gap between research and “industrial” practice in Web systems. The use of new technologies, tools and methodologies is increasing in the Web and it makes the systems more and more interactive and responsive than in the past. Therefore, limits and problems related to specific aspects of systems quality and dependability are investigated, and new approaches and ideas are proposed to overcome such limitations.     

Coordination of purchasing and bidding activities across posted offer and auction markets

In both consumer purchasing and industrial procurement, combinatorial interdependencies among the items to be purchased are commonplace. E-commerce compounds the problem by providing more opportunities for switching suppliers at low costs, but also potentially eases the problem by enabling automated market decision-making systems, commonly referred to as trading agents, to make purchasing decisions in an integrated manner across markets. We are investigating a new approach to deal with the combinatorial interdependency challenges for online markets. This approach relies on existing commercial online market institutions such as posted-offer markets and various online auctions that sell single items. It uses trading agents to coordinate a buyer’s purchasing and bidding activities across multiple online markets simultaneously to achieve the best overall procurement effectiveness. This paper presents two sets of models related to this approach. The first set of models formalizes optimal purchasing decisions across posted-offer markets with fixed transaction costs. The second set of models is concerned with the coordination of bidding activities across multiple online auctions.Research reported in this paper was partially supported by a Proposition 301 Electronic Commerce Grant, University of Arizona Eller College of Management. The first author is also affiliated with The Key Lab of Complex Systems and Intelligence Science, Chinese Academy of Sciences (CAS), Beijing, and was supported in part by a grant for open research projects (ORP-0303) from CAS. Earlier versions of this paper have appeared in the Proceedings of the Hawai’i International Conference on System Sciences (HICSS-37) and the Proceedings of the 13th Annual Workshop on Information Technology and Systems (WITS ’03).