Model Checking to Improve Precision of Design Pattern Instances Identification in OO Systems

In the last two decades some methods and tools have been proposed to identify the Design Pattern (DP) instances implemented in an existing Object Oriented (OO) software system. This allows to know which OO components are involved in each DP instance. Such a knowledge is useful to better understand the system thus reducing the effort to modify and evolve it. The results obtained by the existing methods and tools can suffer a lack of completeness or precision due to the presence of false positive/negative. Model Checking (MC) algorithms can be used to improve the precision of DP's instances detected by a tool by automatically refining the results it produces. In this paper a MC based technique is defined and applied to the results of an existing DPs mining tool, called Design Pattern Finder (DPF), to improve the precision by verifying automatically the DPs instances it detects. To verify and assess the feasibility and the effectiveness of the proposed technique, we carried out a case study where it was applied on some open source OO systems. The results showed that the proposed technique allowed to improve the precision of the DPs instances detected by the DPF tool

Analysing Wiki Quality using Probabilistic Model Checking

Abstract-Wikis delineate a new work tool in enterprises and they are spreading everywhere. Indeed, they are often used as internal documentation for various in-house systems and applications as well as powerful tools for collaboration and knowledge sharing. As occurs with software, the fundamental growth of a wiki may lead to its degradation. The quality of wikis, especially in enterprise contexts, should not play a trivial role. Software quality is a very discussed topic, but there are not many studies regarding the quality of wikis. We propose a probabilistic model to represent wikis and to investigate their quality. Due to the similarity with the World Wide Web it is natural to consider the popular Google PageRank (with minor modifications) to calculate probabilities between pages. Each wiki category, a set of wiki pages, is modelled using the PRISM language in order to verify specific properties in PCTL*. Experiments conducted on a adequate number of (enterprise) wikis assess the validity of our methodology

Requirements specification using concrete scenarios

The precision of formal specifications allows us to prove program correctness. Even if formal methods are not used throughout the software project, formalisation improves our understanding of the problem. Formal specifications are amenable to automated analysis and consistency checking. However using them is challenging. Customers do not understand formal notations. Specifiers have difficulty tackling large problems. Once systems are built, formal specifications quickly become outdated during software maintenance. A method of developing formal specifications using concrete scenarios is proposed to tackle the disadvantages just mentioned. A concrete scenario describes system behaviour with successive steps. The pre- and post-states of scenario steps are expressed with actual data rather than variables. Concrete scenarios are expressed in a natural language or formal notation. They increase customer involvement in the creation of formal specifications. Scenarios may be ranked by priorities allowing specifiers to focus on a small part of the system. Formal specifications are constructed incrementally. New requirements are also captured in concrete scenarios which guide the modification of formal specifications. On one hand, concrete scenarios assist the creation and maintenance of formal specifications. On the other hand, they facilitate program correctness proofs without using conventional formal specifications. This is achieved by adding implementation details to customer scenarios. The resulting developer scenarios, encapsulating decisions of data structures and algorithms, are generalised to operation schemas. With the implementation details, the schemas written in formal notations are programs rather than specifications.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Michael C. Astour: A Biographical Essay

Michael Astour\u27s scholarly productivity was prodigious and was recognized and respected by the international community of historians of the ancient Near East. His accomplishments would have been impressive in anyone, but were especially so given the tumultuous and tragic events of his personal life, which were part and parcel of the tragic and tumultuous century in which he lived. The Festschrift that grew out of a celebratory conference in his honor begins with a paraphrase of an ancient Sumerian proverb: “A scribe who does not know Sumerian, what kind of a scribe is he?” It reads, “Scholars of Mediterranean, Biblical and Near Eastern Studies who do not know the work of Michael Astour, what kind of scholars are they?”[1] Obviously, that’s a rhetorical and somewhat hyperbolic question, and I lack the knowledge to pass judgment with any confidence on his work. Ignorance is easily impressed. Nevertheless, the story of Michael Astour’s life deserves to be told, if only by someone who is definitely not a scholar of the ancient Near East, but who knew him as a colleague. Many of his friends and colleagues urged him over the years to write a memoir, something he adamantly refused to do. This may have been due in part to the pain that such an effort would have caused him, although he argued that others had told similar stories better than he could. But, finally, he may have regarded such an undertaking simply as an unwelcome distraction from the scholarship that he loved and that he pursued almost to his dying day.[2] This essay is based largely on Astour’s voluminous correspondence spanning a half- century. He meticulously saved letters he received, as well as copies of those he sent. His papers fill dozens of boxes in SIUE’s archives. Many of his letters are multi-paged and are uniformly thoughtful and frequently witty. They stand in stark contrast to the brief and often superficial electronic communications that pass for inter-personal correspondence today which is, in most cases and, perhaps appropriately, transitory. They exemplify a category of historical source material that, sadly, is no longer being generated. [1] Gordon Young, Mark Chavalas, Richard Averbeck, eds., Crossing Boundaries and Linking Horizons: Studies in Honor of Michael C. Astour on His 80th Birthday [Bethesda, MD., 1997], xi. [2] Astour to Chavalas, March 2, 1992, Box 25

The archive of place : environment and the contested past of a North American plateau

Thesis (Ph. D.)--Massachusetts Institute of Technology. Program in Science, Technology and Society, 2004.Includes bibliographical references (p. 310-337).This is a study of the role that the interpretation of material evidence plays in historical consciousness and social memory. It consists of three case studies from the Chilcotin Plateau in the west-central part of present-day British Columbia. In each, a conflict in the mid-1990s over the nature of the past and its relevance for the present allowed underlying stories to emerge. As different groups struggled to control the fate of the region and its resources, they invoked very different understandings of its past, understandings based in part on the material traces that they found there. Taken together, the case studies illustrate the fact that there is an extensive division of interpretive labor when it comes to the material evidence of the past. Like other kinds of labor, this interpretation takes part in a political economy. Studies of material evidence are done to further the interests of individuals or groups, are valued and exchanged with one another, and are important in the delineation of property rights, the enforcement of laws and the justification of ideologies. What emerges is not an authoritative or univocal environmental history of a place, but rather a contest to find a past which will be usable in the present and future. The constant interpretation of material evidence allows people to situate themselves with respect to place, time and other people.by William J. Turkel.Ph.D

The fault lines of violent conflict in Tajikistan

This thesis examines the outbreak, spread, and eventual subsidence of violence in Tajikistan during the first phase of the Tajik Civil War (1992-1997). The violent conflict in southern Tajikistan lasted roughly from spring 1992 until the war's official end in June 1997 with the signing of a broad peace agreement and power-sharing arrangement. As noted above, I will concentrate my analysis on the first phase of conflict that finished at the end of 1992. During this early period the vast majority of fatalities occurred - including both civilians and armed combatants. The myriad social and political divisions of this era necessitate an in-depth historical and social analysis of ethnicity, religion, social organisation, migration, state-building, politics and economics in Tajikistan (especially during the Soviet era). All of these factors - to varying degrees - affected the loyalties and actions of individuals and groups during the pre-war era though the outbreak of conflict. The 'security dilemma' and 'credible commitment problem' will be demonstrated to be effective tools for analysing the logic behind the outbreak and continuation of conflict in Tajikistan. The analysis of the distinct regional and, in some cases ethnic, characteristics of the opposing armed groups will show how the 'mobilising structures' were limited, or even captured, by the pre-existing networks and politically and economically relevant regional and ethnic identities in Tajikistan. The process whereby national-level political competition was intimately attached to local conflicts - resulting in the rapid spread of violence in rural areas - will be clearly illustrated using the concept of 'alliance', a process whereby seemingly unrelated local agendas quickly attach to broader cleavages at the national level. And finally, explaining why indiscriminate violence was used against civilian populations and why it was eventually abandoned as a tactic, an adaption of the theory of 'indiscriminate violence' will be used as an analytical tool. The resulting analysis, combined with a complete narrative of 1992, fills a gap in the literature on the Tajik Civil War as other accounts focus primarily on the variables that resulted in the outbreak of conflict or on the peace process and post-conflict era. -- provided by Candidate