872 research outputs found

    Mining Butterflies in Streaming Graphs

    Get PDF
    This thesis introduces two main-memory systems sGrapp and sGradd for performing the fundamental analytic tasks of biclique counting and concept drift detection over a streaming graph. A data-driven heuristic is used to architect the systems. To this end, initially, the growth patterns of bipartite streaming graphs are mined and the emergence principles of streaming motifs are discovered. Next, the discovered principles are (a) explained by a graph generator called sGrow; and (b) utilized to establish the requirements for efficient, effective, explainable, and interpretable management and processing of streams. sGrow is used to benchmark stream analytics, particularly in the case of concept drift detection. sGrow displays robust realization of streaming growth patterns independent of initial conditions, scale and temporal characteristics, and model configurations. Extensive evaluations confirm the simultaneous effectiveness and efficiency of sGrapp and sGradd. sGrapp achieves mean absolute percentage error up to 0.05/0.14 for the cumulative butterfly count in streaming graphs with uniform/non-uniform temporal distribution and a processing throughput of 1.5 million data records per second. The throughput and estimation error of sGrapp are 160x higher and 0.02x lower than baselines. sGradd demonstrates an improving performance over time, achieves zero false detection rates when there is not any drift and when drift is already detected, and detects sequential drifts in zero to a few seconds after their occurrence regardless of drift intervals

    IMAGINING, GUIDING, PLAYING INTIMACY: - A Theory of Character Intimacy Games -

    Get PDF
    Within the landscape of Japanese media production, and video game production in particular, there is a niche comprising video games centered around establishing, developing, and fulfilling imagined intimate relationships with anime-manga characters. Such niche, although very significant in production volume and lifespan, is left unexplored or underexplored. When it is not, it is subsumed within the scope of wider anime-manga media. This obscures the nature of such video games, alternatively identified with descriptors including but not limited to ā€˜visual novelā€™, ā€˜dating simulatorā€™ and ā€˜adult computer gameā€™. As games centered around developing intimacy with characters, they present specific ensembles of narrative content, aesthetics and software mechanics. These ensembles are aimed at eliciting in users what are, by all intents and purposes, parasocial phenomena towards the gameā€™s characters. In other words, these software products encourage players to develop affective and bodily responses towards characters. They are set in a way that is coherent with shared, circulating scripts for sexual and intimate interaction to guide player imaginative action. This study defines games such as the above as ā€˜character intimacy gamesā€™, video game software where traversal is contingent on players knowingly establishing, developing, and fulfilling intimate bonds with fictional characters. To do so, however, player must recognize themselves as playing that type of game, and to be looking to develop that kind of response towards the gameā€™s characters. Character Intimacy Games are contingent upon player developing affective and bodily responses, and thus presume that players are, at the very least, non-hostile towards their development. This study approaches Japanese character intimacy games as its corpus, and operates at the intersection of studies of communication, AMO studies and games studies. The study articulates a research approach based on the double need of approaching single works of significance amidst a general scarcity of scholarly background on the subject. It juxtaposes data-driven approaches derived from fan-curated databases ā€“ The Visual Novel Database and Erogescape -Erogē Hyōron KÅ«kan ā€“ with a purpose-created ludo-hermeneutic process. By deploying an observation of character intimacy games through fan-curated data and building ludo-hermeneutics on the resulting ontology, this study argues that character intimacy games are video games where traversal is contingent on players knowingly establishing, developing, and fulfilling intimate bonds with fictional characters and recognizing themselves as doing so. To produce such conditions, the assemblage of software mechanics and narrative content in such games facilitates intimacy between player and characters. This is, ultimately, conductive to the emergence of parasocial phenomena. Parasocial phenomena, in turn, are deployed as an integral assumption regarding player activity within the gameā€™s wider assemblage of narrative content and software mechanics

    Quantifying the structural stability of simplicial homology

    Full text link
    The homology groups of a simplicial complex reveal fundamental properties of the topology of the data or the system and the notion of topological stability naturally poses an important yet not fully investigated question. In the current work, we study the stability in terms of the smallest perturbation sufficient to change the dimensionality of the corresponding homology group. Such definition requires an appropriate weighting and normalizing procedure for the boundary operators acting on the Hodge algebra's homology groups. Using the resulting boundary operators, we then formulate the question of structural stability as a spectral matrix nearness problem for the corresponding higher-order graph Laplacian. We develop a bilevel optimization procedure suitable for the formulated matrix nearness problem and illustrate the method's performance on a variety of synthetic quasi-triangulation datasets and transportation networks.Comment: 25 pages, 9 figure

    FPT Constant-Approximations for Capacitated Clustering to Minimize the Sum of Cluster Radii

    Get PDF
    Clustering with capacity constraints is a fundamental problem that attracted significant attention throughout the years. In this paper, we give the first FPT constant-factor approximation algorithm for the problem of clustering points in a general metric into kk clusters to minimize the sum of cluster radii, subject to non-uniform hard capacity constraints. In particular, we give a (15+Ļµ)(15+\epsilon)-approximation algorithm that runs in 20(k2logā”k)ā‹…n32^{0(k^2\log k)}\cdot n^3 time. When capacities are uniform, we obtain the following improved approximation bounds: A (4 + Ļµ\epsilon)-approximation with running time 2O(klogā”(k/Ļµ))n32^{O(k\log(k/\epsilon))}n^3, which significantly improves over the FPT 28-approximation of Inamdar and Varadarajan [ESA 2020]; a (2 + Ļµ\epsilon)-approximation with running time 2O(k/Ļµ2ā‹…logā”(k/Ļµ))dn32^{O(k/\epsilon^2 \cdot\log(k/\epsilon))}dn^3 and a (1+Ļµ)(1+\epsilon)-approximation with running time 2O(kdlogā”((k/Ļµ)))n32^{O(kd\log ((k/\epsilon)))}n^{3} in the Euclidean space; and a (1 + Ļµ\epsilon)-approximation in the Euclidean space with running time 2O(k/Ļµ2ā‹…logā”(k/Ļµ))dn32^{O(k/\epsilon^2 \cdot\log(k/\epsilon))}dn^3 if we are allowed to violate the capacities by (1 + Ļµ\epsilon)-factor. We complement this result by showing that there is no (1 + Ļµ\epsilon)-approximation algorithm running in time f(k)ā‹…nO(1)f(k)\cdot n^{O(1)}, if any capacity violation is not allowed.Comment: Full version of a paper accepted to SoCG 202

    Each book its own Babel:Conceptual unity and disunity in early modern natural philosophy

    Get PDF
    Natural philosophy changed quickly during the early modern period (1600-1800). Aristotelian philosophy was combated by Cartesian mechanicism, which was soon itself ousted by the Newtonian school. The development of new ideas within a scientific discipline is partially an issue of doing empirical research, in order to exclude positions and progress the field. However, it is also an issue of developing new concepts and a fitting language, in order to be able to express all these new positions being investigated. This second development however also implies that the differences between thinkers might grow too large - the languages in which they express their philosophy can become too different for them to have a meaningful discussion. In this dissertation I investigate, using algorithms that extract the meaning of words from texts, a few hundred texts from these three different school. I do this in order to see how they differ from each other conceptually, how the meaning of words can travel through lines of influence from author to author and how guarding the boundaries of a school and guarding the language they use, relate

    Bridging the Gaps: Connecting Research Streams in Organizational Network Research

    Get PDF
    Apart from an introduction and conclusion, the present dissertation consists of four chapters in the form of three research papers and one essay. Each of these chapters revolves around organizational networks and attempts to bring research streams together that deal with the same ā€“ or similar ā€“ phenomena, yet are largely disjunct. In that sense, each chapter is attempting to bridge gaps. The first of these chapters investigates partner selection in business ecosystems and brings together the ecosystem and network literature. Second is an essay which introduces four new effects to a popular method for analyzing network dynamics, bringing together management science and mathematics. Third is a research paper analyzing the interdependence between corporate strategic actions and board interlock networks, bringing together the antecedents and outcomes of the latter. And finally, the fourth of these chapters brings together director- and firm-level research on board interlock networks by estimating the formation of such a network when introducing both levels into a stochastic model. The dissertation advances our understanding of organizational networks and the methods we can use to learn about them

    CAUSAL ORIGINS OF THE ā€˜RELIGIOUS MOVEMENT OF THE MIDDLE AGES': CLUNY, TIRON, AND THE NEW ORDERS, 910-1156

    Get PDF
    Around the turn of the twelfth century, Western Europe underwent a profound ideological transformation. With the flourishing of new religious orders, heresies and sects, a new spirit captured the Latin West which glorified the asceticism of the early Church beyond all previous bounds and elevated the life of the poor itinerant preacher as its salvationary ideal. This Herbert Grundmann would call ā€˜the single religious movement of the Middle Agesā€™. Yet, for all its apparent import and power, history has thus far been unable to illuminate the fundamental causes of how this new ideology might have been generated, focussing instead on how new ideas may have been ā€˜transmittedā€™ into the Latin West from the near East. The aim of this thesis, therefore, is to remedy this gap in our knowledge by uncovering instead the epistemically ā€˜generativeā€™ causal mechanisms of just such a ā€˜religious movement of the Middle Agesā€™, by advancing two interconnected hypotheses: that ā€˜ideasā€™ may be assembled by the a posteriori experience and observation of pre-mental ā€˜patterns of lifeā€™, and that the principal force responsible for the novel monastic ā€˜patterns of lifeā€™ in this period was a newly aggressive and expansionary Benedictine monasticism best typified by Cluny. In other words, that the origins of the new orders in ā€˜Franceā€™, and the ideology they espoused, is to be found in the systemic pressure applied by the growing influence of Cluny on the structure of the Church

    MCMC methods: graph samplers, invariance tests and epidemic models

    Get PDF
    Markov Chain Monte Carlo (MCMC) techniques are used ubiquitously for simulation-based inference. This thesis provides novel contributions to MCMC methods and their application to graph sampling and epidemic modeling. The first topic considered is that of sampling graphs conditional on a set of prescribed statistics, which is a difficult problem arising naturally in many fields: sociology (Holland and Leinhardt, 1981), psychology (Connor and Simberloff, 1979), categorical data analysis (Agresti, 1992) and finance (Squartini et al., 2018, Gandy and Veraart, 2019) being examples. Bespoke MCMC samplers are proposed for this setting. The second major topic addressed is that of modeling the dynamics of infectious diseases, where MCMC is leveraged as the general inference engine. The first part of this thesis addresses important problems such as the uniform sampling of graphs with given degree sequences, and weighted graphs with given strength sequences. These distributions are frequently used for exact tests on social networks and two-way contingency tables. Another application is quantifying the statistical significance of patterns observed in real networks. This is crucial for understanding whether such patterns indicate the presence of interesting network phenomena, or whether they simply result from less interesting processes, such as nodal-heterogeneity. The MCMC samplers developed in the course of this research are complex, and there is great scope for conceptual, analytic, and implementation errors. This motivates a chapter that develops novel tests for detecting errors in MCMC implementations. The tests introduced are unique in being exact, which allows us to keep the false rejection probability arbitrarily low. Rather than develop bespoke samplers, as in the first part of the thesis, the second part leverages a standard MCMC framework Stan (Stan Development Team, 2018) as the workhorse for fitting state-of-the-art epidemic models. We present a general framework for semi-mechanistic Bayesian modeling of infectious diseases using renewal processes. The term semi-mechanistic relates to statistical estimation within some constrained mechanism. This research was motivated by the ongoing SARS-COV-2 pandemic, and variants of the model have been used in specific analyses of Covid-19. We present epidemia, an R package allowing researchers to leverage the epidemic models. A key goal of this work is to demonstrate that MCMC, and in particular, Stanā€™s No-U-Turn (Hoffman and Gelman, 2014) sampler, can be routinely employed to fit a large-class of epidemic models. A second goal is to make the models accessible to the general research community, through epidemia.Open Acces

    Translanguaging for Equal Opportunities : Speaking Romani at School

    Get PDF
    This multi-authored monograph, located in the intersection of translanguaging research and Romani studies, offers a state-of-the-art analysis of the ways in which translanguaging supports bilingual Roma studentsā€™ learning in monolingual school systems. Complete with a video repository of translanguaging classroom moments, this comprehensive study is based on long-term participatory ethnographic research and a pedagogical implementation project undertaken in Hungary and Slovakia by a group of primary teachers, bilingual Roma participants, and researchers. Co-written by academic and non-academic participants, the book is an essential reading for researchers, pre- and in-service teachers of Romani-speaking students, and experts working with collaborators (learners, informants, activists) whose home languages are excluded from mainstream education and school curricula
    • ā€¦
    corecore