3,571 research outputs found

    A Unifying Theory for Graph Transformation

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    The field of graph transformation studies the rule-based transformation of graphs. An important branch is the algebraic graph transformation tradition, in which approaches are defined and studied using the language of category theory. Most algebraic graph transformation approaches (such as DPO, SPO, SqPO, and AGREE) are opinionated about the local contexts that are allowed around matches for rules, and about how replacement in context should work exactly. The approaches also differ considerably in their underlying formal theories and their general expressiveness (e.g., not all frameworks allow duplication). This dissertation proposes an expressive algebraic graph transformation approach, called PBPO+, which is an adaptation of PBPO by Corradini et al. The central contribution is a proof that PBPO+ subsumes (under mild restrictions) DPO, SqPO, AGREE, and PBPO in the important categorical setting of quasitoposes. This result allows for a more unified study of graph transformation metatheory, methods, and tools. A concrete example of this is found in the second major contribution of this dissertation: a graph transformation termination method for PBPO+, based on decreasing interpretations, and defined for general categories. By applying the proposed encodings into PBPO+, this method can also be applied for DPO, SqPO, AGREE, and PBPO

    On the real world practice of Behaviour Driven Development

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    Surveys of industry practice over the last decade suggest that Behaviour Driven Development is a popular Agile practice. For example, 19% of respondents to the 14th State of Agile annual survey reported using BDD, placing it in the top 13 practices reported. As well as potential benefits, the adoption of BDD necessarily involves an additional cost of writing and maintaining Gherkin features and scenarios, and (if used for acceptance testing,) the associated step functions. Yet there is a lack of published literature exploring how BDD is used in practice and the challenges experienced by real world software development efforts. This gap is significant because without understanding current real world practice, it is hard to identify opportunities to address and mitigate challenges. In order to address this research gap concerning the challenges of using BDD, this thesis reports on a research project which explored: (a) the challenges of applying agile and undertaking requirements engineering in a real world context; (b) the challenges of applying BDD specifically and (c) the application of BDD in open-source projects to understand challenges in this different context. For this purpose, we progressively conducted two case studies, two series of interviews, four iterations of action research, and an empirical study. The first case study was conducted in an avionics company to discover the challenges of using an agile process in a large scale safety critical project environment. Since requirements management was found to be one of the biggest challenges during the case study, we decided to investigate BDD because of its reputation for requirements management. The second case study was conducted in the company with an aim to discover the challenges of using BDD in real life. The case study was complemented with an empirical study of the practice of BDD in open source projects, taking a study sample from the GitHub open source collaboration site. As a result of this Ph.D research, we were able to discover: (i) challenges of using an agile process in a large scale safety-critical organisation, (ii) current state of BDD in practice, (iii) technical limitations of Gherkin (i.e., the language for writing requirements in BDD), (iv) challenges of using BDD in a real project, (v) bad smells in the Gherkin specifications of open source projects on GitHub. We also presented a brief comparison between the theoretical description of BDD and BDD in practice. This research, therefore, presents the results of lessons learned from BDD in practice, and serves as a guide for software practitioners planning on using BDD in their projects

    UMSL Bulletin 2023-2024

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    The 2023-2024 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1088/thumbnail.jp

    Natural and Technological Hazards in Urban Areas

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    Natural hazard events and technological accidents are separate causes of environmental impacts. Natural hazards are physical phenomena active in geological times, whereas technological hazards result from actions or facilities created by humans. In our time, combined natural and man-made hazards have been induced. Overpopulation and urban development in areas prone to natural hazards increase the impact of natural disasters worldwide. Additionally, urban areas are frequently characterized by intense industrial activity and rapid, poorly planned growth that threatens the environment and degrades the quality of life. Therefore, proper urban planning is crucial to minimize fatalities and reduce the environmental and economic impacts that accompany both natural and technological hazardous events

    LIPIcs, Volume 251, ITCS 2023, Complete Volume

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    LIPIcs, Volume 251, ITCS 2023, Complete Volum

    Advances and Applications of DSmT for Information Fusion. Collected Works, Volume 5

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    This fifth volume on Advances and Applications of DSmT for Information Fusion collects theoretical and applied contributions of researchers working in different fields of applications and in mathematics, and is available in open-access. The collected contributions of this volume have either been published or presented after disseminating the fourth volume in 2015 in international conferences, seminars, workshops and journals, or they are new. The contributions of each part of this volume are chronologically ordered. First Part of this book presents some theoretical advances on DSmT, dealing mainly with modified Proportional Conflict Redistribution Rules (PCR) of combination with degree of intersection, coarsening techniques, interval calculus for PCR thanks to set inversion via interval analysis (SIVIA), rough set classifiers, canonical decomposition of dichotomous belief functions, fast PCR fusion, fast inter-criteria analysis with PCR, and improved PCR5 and PCR6 rules preserving the (quasi-)neutrality of (quasi-)vacuous belief assignment in the fusion of sources of evidence with their Matlab codes. Because more applications of DSmT have emerged in the past years since the apparition of the fourth book of DSmT in 2015, the second part of this volume is about selected applications of DSmT mainly in building change detection, object recognition, quality of data association in tracking, perception in robotics, risk assessment for torrent protection and multi-criteria decision-making, multi-modal image fusion, coarsening techniques, recommender system, levee characterization and assessment, human heading perception, trust assessment, robotics, biometrics, failure detection, GPS systems, inter-criteria analysis, group decision, human activity recognition, storm prediction, data association for autonomous vehicles, identification of maritime vessels, fusion of support vector machines (SVM), Silx-Furtif RUST code library for information fusion including PCR rules, and network for ship classification. Finally, the third part presents interesting contributions related to belief functions in general published or presented along the years since 2015. These contributions are related with decision-making under uncertainty, belief approximations, probability transformations, new distances between belief functions, non-classical multi-criteria decision-making problems with belief functions, generalization of Bayes theorem, image processing, data association, entropy and cross-entropy measures, fuzzy evidence numbers, negator of belief mass, human activity recognition, information fusion for breast cancer therapy, imbalanced data classification, and hybrid techniques mixing deep learning with belief functions as well

    Data Management in Distributed Systems

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    A aplicação e a adesão de arquiteturas distribuídas por parte das maiores empresas do mundo demonstram que estas são das mais utilizadas e que apresentam maiores benefícios numa larga escala. O facto de um sistema complexo conseguir ser dividido em vários pequenos serviços fáceis de manter e suportar beneficia essa mesma divisão de responsabilidades pelas variadas equipas das grandes empresas. No entanto, tendo em consideração esta grande adesão e apesar de todos os benefícios visíveis, a aplicação deste tipo de arquiteturas não é de todo perfeita. A utilização de um sistema distribuído deve ser bem pensada, desenhada e elaborada de forma que apareçam o menor número possível de problemas. Um dos possíveis problemas resultantes de um fraco desenho e pensamento de solução consiste na má gestão e consistência dos dados e informação no sistema e nos seus serviços. Na tentativa de melhorar o processo de desenho de uma solução, foi desenvolvido um estudo dos possíveis padrões de boas práticas e as melhores abordagens, bem como as situações adequadas a serem aplicadas. Assim, desenvolveu-se um guião que pormenoriza os passos a seguir assim como as dificuldades e questões a ter em conta. Para além disso, realizou-se uma análise bibliográfica do tema, tendo em atenção o que já tinha sido descrito na área e os conceitos mais importantes que faltavam ser mencionados. O guião foi elaborado com o intuito de ser aplicado, futuramente, em ambientes empresariais ou organizacionais, tendo sido também aplicado num caso de estudo com o objetivo de verificar se as boas práticas a serem seguidas resultam num sistema compacto e consistente sem falhas relativas à gestão de dados.The application and adoption of distributed architectures by the largest companies in the world demonstrate that these are the most used and that they present greater benefits on a large scale. The fact that a complex system can be divided into several small services that are easy to maintain and support benefits that same division of responsibilities by the various teams of large companies. However, considering this large number of people and despite all the visible benefits, the application of this type of architecture is not entirely perfect. The use of a distributed system must be well thought out, designed, and elaborated in such a way that the smallest possible number of problems appear. One of the possible problems resulting from poor design and solution thinking is poor management and consistency of data and information in the system and its services. To improve the process of designing a solution, a study of possible standards of good practice and the best approaches was developed, as well as the appropriate situations to be applied. Thus, a guide was developed that details the steps to be followed, as well as the difficulties and issues to be considered. In addition, a bibliographical analysis of the theme was carried out, considering what had already been described in the area and the most important concepts that remained to be mentioned. The guide was prepared with the intention of being applied, in the future, in business or organizational environments, having also been applied in a case study with the objective of verifying if the good practices to be followed result in a compact and consistent system without failures related to management. of data

    Bridging Micro- and Macro- Evolution In Tropical Fishes

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    In marine environments, barriers to dispersal can be challenging to identify because they are often cryptic. Unlike terrestrial environments, where a mountain chain that is visible can physically separate two populations of animals, vast masses of water in the ocean make it challenging to pinpoint these barriers. Therefore, the impact of these barriers on the formation of new species in the ocean is still not well understood. While most marine populations have long been considered to be well connected via long-distance dispersal, molecular ecology studies are increasingly unveiling inconspicuous barriers that promote population divergence and ultimately speciation. The advent of genomic techniques that allow the generation of data for thousands of genes has provided an unprecedented opportunity to uncover marine barriers that were previously invisible using more rudimentary tools. This, in turn, has opened new avenues for understanding of how barriers to dispersal affect population connectivity in the marine environment. The overarching goal of my dissertation is to use genome-wide data to look for genetic patterns that correspond to such barriers, and to test for their effect at short-, intermediate- and long-term evolutionary scales, going through a continuum from micro- to macro-evolution, in a time span from thousands to millions of years. At the short-scale, I examined two controversial cases of species delimitation. Species delimitation is a major question in biology and is essential for adequate management of organismal diversity. The first challenging case involves the red snappers in the Western Atlantic. Red snappers have been traditionally recognized as two separate species based on morphology: Lutjanus campechanus (northern red snapper) and L. purpureus (southern red snapper). However, recent genetic studies using few molecular markers failed to delineate these nominal species, lumping the northern and southern populations into a single species (L. campechanus). To evaluate if the populations of these fish represent one or two species, my project applied ca. 40,000 genome-wide markers of 178 individuals collected throughout the range of the two species and population and species delimitation analyses. Overall, my results supported the isolation and differentiation of these species, a result that confirmed the morphology-based delimitation scenario, highlighting the benefits of using genome-wide data in complex cases of species delimitation (Chapter I, published in Proc. Roy. Soc. B in 2019). The second study case involves a species complex of silverside fishes (Chirostoma humboltianum group: Atherinidae) in the Central Mexico plateau. The humboltianum group represents a taxonomically-controversial species complex where previous morphological and molecular studies based on a few genes produced conflicting species delineation scenarios. I applied an integrative approach that considered multiple lines of evidence to investigate the species numbers and boundaries comprising this contentious group. I used ca. 33,000 molecular markers for 77 individuals representing the nine nominal species in the group, spanning their distribution range in the central Mexico plateau, in combination with morphologic and ecologic information. My findings are inconsistent with the morphospecies and ecological delimitation scenarios, identifying three to four species. This study provides an atypical example in which genome-wide analyses delineate fewer species than previously recognized on the basis of morphological data alone. It also highlights the influence of geologic history as a main driver of speciation in the group (Chapter II, published in BMC Eco. Evol. B in 2022). At the intermediate- scale, I evaluated the influence of historical (e.g., geophysical events) and contemporary barriers (e.g., habitat gaps) hindering genetic flow among populations by studying the spatio-temporal phylogenetic concordance of co-distributed lineages. For this study, I investigated the comparative phylogeography of labrisomid blennies in the genus Malacoctenus. I generated data for ca. 28K genome-wide markers that were sequenced from over 500 individuals collected from 38 locations, representing 23 (out of 25) species of Malacoctenus. With this dataset, I assessed the effect of recognized historical (e.g., the rising of the Isthmus of Panama) and contemporary barriers (e.g., sandy gaps) in the Tropical Eastern Pacific (TEP) and the Tropical Atlantic (TA) biogeographic realms. These blennies represent an ideal system to test the effect of such barriers as they are strongly associated with rocky habitats and coral reefs. Therefore, subtle habitat disruptions may lead to genetic isolation. At the micro-evolutionary scale, the observed population structure patterns identified the Sinaloan and Central American breaks as the major breaks in the TEP; and the Bahamas and Eastern Caribbean breaks as key barriers disrupting connectivity in the TA. All in all, the effect of these breaks varies across species, suggesting that species-specific traits (e.g., habitat preference), also greatly influence their dispersal capabilities. My study identified five instances where marine barriers promoted the diversification of independent evolutionary lineages that could potentially represent species complexes. Some of them supported by evidence of population differentiation from previous morphological analyses as well as by my geometric morphometric analyses. Major environmental variables driving population differentiation in the TEP are depth, temperature, chlorophyll altogether with spatial components, while in the TA suspended particle matter also influences diversification. At the long-term scale, my results suggest that depth is a primary driver of speciation in the TEP, leading to niche divergence between tide pool- and reef-associated clades. In contrast, in the TA, patterns of environmental association appeared more intricate, where depth, temperature, chlorophyll and physical features significantly contributing to speciation in this region. Finally, our time-calibrated analyses at macroevolutionary scales elucidated an Eastern Atlantic origin of the clade followed by an east-to-west dispersal. Although the historical break attributed to the rise of the Isthmus of Panama had a substantial influence on the evolutionary history of the genus, our analyses demonstrate that it did not triggered synchronous cladogenetic events. In summary, by using a combination of population genomics, comparative phylogeography, phylogenomics, seascape genomics, and geometric morphometric approaches, this study highlights major contemporary and historical barriers hindering population connectivity in the TEP and TA biogeographic regions, enhancing our understanding of the forces and processes generating new species in marine systems (Chapter III, to be submitted for publication). All in all, my thesis highlights that the use of genome-wide data provides unprecedented resolution to unveil patterns of genetic structure, commonly unraveling cryptic diversity, and the opportunity to address species delimitation problems. By uncovering the spatio-temporal genetic patterns of fishes along the evolutionary continuum, my dissertation provides novel insights into the evolutionary and biogeographic history of marine and freshwater Neotropical fishes. Overall, my dissertation not only helps to understand the evolutionary history of the species under study, but more generally, elucidate factors driving evolutionary process in the marine realm, ranging from population-level scales, to speciation, to higher level relationships among groups

    Topology of Cut Complexes of Graphs

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    We define the kk-cut complex of a graph GG with vertex set V(G)V(G) to be the simplicial complex whose facets are the complements of sets of size kk in V(G)V(G) inducing disconnected subgraphs of GG. This generalizes the Alexander dual of a graph complex studied by Fr\"oberg (1990), and Eagon and Reiner (1998). We describe the effect of various graph operations on the cut complex, and study its shellability, homotopy type and homology for various families of graphs, including trees, cycles, complete multipartite graphs, and the prism Kn×K2K_n \times K_2, using techniques from algebraic topology, discrete Morse theory and equivariant poset topology.Comment: 36 pages, 10 figures, 1 table, Extended Abstract accepted for FPSAC2023 (Davis
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