Alexander Chatzigeorgiou

Bio: Alexander Chatzigeorgiou is an academic researcher from University of Macedonia. The author has contributed to research in topics: Technical debt & Software. The author has an hindex of 30, co-authored 180 publications receiving 3743 citations. Previous affiliations of Alexander Chatzigeorgiou include University of Groningen & Aristotle University of Thessaloniki.

Design Pattern Detection Using Similarity Scoring

Abstract: The identification of design patterns as part of the reengineering process can convey important information to the designer. However, existing pattern detection methodologies generally have problems in dealing with one or more of the following issues: identification of modified pattern versions, search space explosion for large systems and extensibility to novel patterns. In this paper, a design pattern detection methodology is proposed that is based on similarity scoring between graph vertices. Due to the nature of the underlying graph algorithm, this approach has the ability to also recognize patterns that are modified from their standard representation. Moreover, the approach exploits the fact that patterns reside in one or more inheritance hierarchies, reducing the size of the graphs to which the algorithm is applied. Finally, the algorithm does not rely on any pattern-specific heuristic, facilitating the extension to novel design structures. Evaluation on three open-source projects demonstrated the accuracy and the efficiency of the proposed method

Identification of Move Method Refactoring Opportunities

Abstract: Placement of attributes/methods within classes in an object-oriented system is usually guided by conceptual criteria and aided by appropriate metrics. Moving state and behavior between classes can help reduce coupling and increase cohesion, but it is nontrivial to identify where such refactorings should be applied. In this paper, we propose a methodology for the identification of Move Method refactoring opportunities that constitute a way for solving many common feature envy bad smells. An algorithm that employs the notion of distance between system entities (attributes/methods) and classes extracts a list of behavior-preserving refactorings based on the examination of a set of preconditions. In practice, a software system may exhibit such problems in many different places. Therefore, our approach measures the effect of all refactoring suggestions based on a novel entity placement metric that quantifies how well entities have been placed in system classes. The proposed methodology can be regarded as a semi-automatic approach since the designer will eventually decide whether a suggested refactoring should be applied or not based on conceptual or other design quality criteria. The evaluation of the proposed approach has been performed considering qualitative, metric, conceptual, and efficiency aspects of the suggested refactorings in a number of open-source projects.

JDeodorant: Identification and Removal of Type-Checking Bad Smells

Abstract: In this demonstration, we present an Eclipse plug-in that automatically identifies type-checking bad smells in Java source code, and resolves them by applying the "replace conditional with polymorphism" or "replace type code with state/strategy " refactorings. To the best of our knowledge there is a lack of tools that identify type-checking bad smells. Moreover, none of the state-of-the-art IDEs support the refactorings that resolve such kind of bad smells.

The financial aspect of managing technical debt

Abstract: ContextTechnical debt is a software engineering metaphor, referring to the eventual financial consequences of trade-offs between shrinking product time to market and poorly specifying, or implementing a software product, throughout all development phases. Based on its inter-disciplinary nature, i.e. software engineering and economics, research on managing technical debt should be balanced between software engineering and economic theories. ObjectiveThe aim of this study is to analyze research efforts on technical debt, by focusing on their financial aspect. Specifically, the analysis is carried out with respect to: (a) how financial aspects are defined in the context of technical debt and (b) how they relate to the underlying software engineering concepts. MethodIn order to achieve the abovementioned goals, we employed a standard method for SLRs and applied it on studies retrieved from seven general-scope digital libraries. In total we selected 69 studies relevant to the financial aspect of technical debt. ResultsThe most common financial terms that are used in technical debt research are principal and interest, whereas the financial approaches that have been more frequently applied for managing technical debt are real options, portfolio management, cost/benefit analysis and value-based analysis. However, the application of such approaches lacks consistency, i.e., the same approach is differently applied in different studies, and in some cases lacks a clear mapping between financial and software engineering concepts. ConclusionThe results are expected to prove beneficial for the communication between technical managers and project managers, in the sense that they will provide a common vocabulary, and will help in setting up quality-related goals, during software development. To achieve this we introduce: (a) a glossary of terms and (b) a classification scheme for financial approaches used for managing technical debt. Based on these, we have been able to underline interesting implications for researchers and practitioners.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

The C programming language

Abstract: This ebook is the first authorized digital version of Kernighan and Ritchie's 1988 classic, The C Programming Language (2nd Ed.). One of the best-selling programming books published in the last fifty years, "K&R" has been called everything from the "bible" to "a landmark in computer science" and it has influenced generations of programmers. Available now for all leading ebook platforms, this concise and beautifully written text is a "must-have" reference for every serious programmers digital library. As modestly described by the authors in the Preface to the First Edition, this "is not an introductory programming manual; it assumes some familiarity with basic programming concepts like variables, assignment statements, loops, and functions. Nonetheless, a novice programmer should be able to read along and pick up the language, although access to a more knowledgeable colleague will help."