1,600 research outputs found

    Fully-Dynamic and Kinetic Conflict-Free Coloring of Intervals with Respect to Points

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    We introduce the fully-dynamic conflict-free coloring problem for a set S of intervals in R^1 with respect to points, where the goal is to maintain a conflict-free coloring for S under insertions and deletions. A coloring is conflict-free if for each point p contained in some interval, p is contained in an interval whose color is not shared with any other interval containing p. We investigate trade-offs between the number of colors used and the number of intervals that are recolored upon insertion or deletion of an interval. Our results include: - a lower bound on the number of recolorings as a function of the number of colors, which implies that with O(1) recolorings per update the worst-case number of colors is Omega(log n/log log n), and that any strategy using O(1/epsilon) colors needs Omega(epsilon n^epsilon) recolorings; - a coloring strategy that uses O(log n) colors at the cost of O(log n) recolorings, and another strategy that uses O(1/epsilon) colors at the cost of O(n^epsilon/epsilon) recolorings; - stronger upper and lower bounds for special cases. We also consider the kinetic setting where the intervals move continuously (but there are no insertions or deletions); here we show how to maintain a coloring with only four colors at the cost of three recolorings per event and show this is tight

    Dynamic range and frequency assignment problems

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    Dynamic Conflict-Free Colorings in the Plane

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    We study dynamic conflict-free colorings in the plane, where the goal is to maintain a conflict-free coloring (CF-coloring for short) under insertions and deletions. - First we consider CF-colorings of a set S of unit squares with respect to points. Our method maintains a CF-coloring that uses O(log n) colors at any time, where n is the current number of squares in S, at the cost of only O(log n) recolorings per insertion or deletion We generalize the method to rectangles whose sides have lengths in the range [1, c], where c is a fixed constant. Here the number of used colors becomes O(log^2 n). The method also extends to arbitrary rectangles whose coordinates come from a fixed universe of size N, yielding O(log^2 N log^2 n) colors. The number of recolorings for both methods stays in O(log n). - We then present a general framework to maintain a CF-coloring under insertions for sets of objects that admit a unimax coloring with a small number of colors in the static case. As an application we show how to maintain a CF-coloring with O(log^3 n) colors for disks (or other objects with linear union complexity) with respect to points at the cost of O(log n) recolorings per insertion. We extend the framework to the fully-dynamic case when the static unimax coloring admits weak deletions. As an application we show how to maintain a CF-coloring with O(sqrt(n) log^2 n) colors for points with respect to rectangles, at the cost of O(log n) recolorings per insertion and O(1) recolorings per deletion. These are the first results on fully-dynamic CF-colorings in the plane, and the first results for semi-dynamic CF-colorings for non-congruent objects

    Conflict-Free Coloring of Points and Simple Regions in the Plane

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    We study conflict-free colorings, where the underlying set systems arise in geometry. Our main result is a general framework for conflict-free coloring of regions with low union complexity. A coloring of regions is conflict-free if for any covered point in the plane, there exists a region that covers it with a unique color (i.e., no other region covering this point has the same color). For example, we show that we can conflict-free color any family of n pseudo-discs with O(log n) color

    Analyzing Harmonic Polarities: A Tonal Narrative Approach

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    This dissertation aims to develop an approach to analyzing common-practice repertoire based on the dynamic interplay of centripetal and centrifugal forces. It aims at interpreting various kinds of chromaticism and modulation in terms of the interaction of forces moving away from the tonic or principal key (centrifugal) and those returning to it (centripetal). Centripetal forces also correspond to the force of cadential substantiation of keys, not only the principal key, which I call temporal-centripetal force; temporal-centrifugal forces correspond to the phenomena of tonal instability, of motion through multiple regions. The dynamic interplay and counterbalancing of these forces is a core concern of the dissertation. In chapter 1 I build upon Arnold Schoenberg\u27s visionary metaphor for modulation as a struggle and a competition between the tonic and its regions, imagined as a sovereign ruler and his subjects. The tendencies of the regions generate centrifugal forces; the ruling tonic\u27s desire to subjugate them correspond to centripetal forces. What I call temporal-centripetal forces correspond to the possibility for temporary centripetal forces to be generated by a region, which becomes the ruler of its own realm. The crucial application to analyzing harmonic motion is that centripetal and centrifugal forces are dynamically interdependent; each requires the other in order to stimulate a living tonal narrative. In order to measure centrifugal forces, the tonal narrative approach draws on Gottfried Weber and Schoenberg\u27s maps of tonal space and Weber\u27s elucidation of degrees of relatedness between keys, which are explored in chapter 2. Centrifugal forces divide into sharp and flat sides or types, which correspond to very general character and coloristic shades: sharp-centrifugal forces associate with brightening and greater activity and flat-centrifugal forces with darkening and sometimes passivity. In chapter 3, I explore how the harmonic motion of entire movements can be divided into distinctive functions that define their overall shape, such as intensifications (accumulations of dissonance or centrifugal force or both), culminations, counterbalancing of sharp- and flat-CF forces, and the attainment a complete tour of keys or regions in the tonal spectrum. This chapter also offers a hierarchy of key-area substantiation, determining the structural significance of regions appearing in tonal narratives. Chapter 4 interprets sonata form in terms of centripetal and centrifugal forces unfolding in broad stages, which often correspond with formal parts but sometimes cross their boundaries. It examines the expansion of centrifugal trajectories in piano sonata development sections by Mozart and Beethoven; the culmination of this expansion is the complete traversal of the enharmonic circle in the Waldstein sonata (first movement). I analyze this development section in terms of the number of fundamental steps travelled from the subordinate key to the point of furthest remove. Chapter 5 develops a hermeneutic reading of Schubert\u27s sonata D. 894/i; centrifugal and centripetal forces are matched to pastoral/epic expressive modes identified in this movement by Robert Hatten. This work also features an immense modulatory trajectory around the enharmonic circle, corresponding to an epic narrative journey into the tonal underworld. A remarkable aspect of the development section is the transient recurrences of passages returning to the pastoral mode and centripetal forces; these provide a welcome contrast and respite from the inexorable flatward trajectory. The conclusion of the dissertation briefly offers some applications of analyzing harmonic polarities to piano performance, drawing particularly on aspects of touch and technique discussed by Boris Berman

    Flexible Object Manipulation

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    Flexible objects are a challenge to manipulate. Their motions are hard to predict, and the high number of degrees of freedom makes sensing, control, and planning difficult. Additionally, they have more complex friction and contact issues than rigid bodies, and they may stretch and compress. In this thesis, I explore two major types of flexible materials: cloth and string. For rigid bodies, one of the most basic problems in manipulation is the development of immobilizing grasps. The same problem exists for flexible objects. I have shown that a simple polygonal piece of cloth can be fully immobilized by grasping all convex vertices and no more than one third of the concave vertices. I also explored simple manipulation methods that make use of gravity to reduce the number of fingers necessary for grasping. I have built a system for folding a T-shirt using a 4 DOF arm and a fixed-length iron bar which simulates two fingers. The main goal with string manipulation has been to tie knots without the use of any sensing. I have developed single-piece fixtures capable of tying knots in fishing line, solder, and wire, along with a more complex track-based system for autonomously tying a knot in steel wire. I have also developed a series of different fixtures that use compressed air to tie knots in string. Additionally, I have designed four-piece fixtures, which demonstrate a way to fully enclose a knot during the insertion process, while guaranteeing that extraction will always succeed

    LIPIcs, Volume 258, SoCG 2023, Complete Volume

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    LIPIcs, Volume 258, SoCG 2023, Complete Volum

    Light Alloys and High-Temperature Alloys

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    Light alloys and high-temperature alloys are widely used as key engineering materials in both the civil and military industries due to their excellent comprehensive properties and performance. Over recent decades, huge amounts of theoretical and/or experimental efforts have been devoted to this field and great achievements have been made. In this book, entitled "Light Alloys and High-Temperature Alloys", there are 14 research papers contributed by 85 authors at 27 universities/institutes/companies from 9 countries, including China, the USA, the UK, Germany, Spain, Australia, Ukraine, Poland, and Romania. The topics cover different types of light alloys, including Al-, Mg-, and Ti-based ones (also Ti-based metal matrix composites), and high-temperature alloys, including Ni-, Fe-, Nb-, and Ta-based ones. Two new types of alloys, i.e., complex concentrated alloys (CCAs) and phase change materials, are also included. Moreover, in this book, a variety of multi-scale theoretical methods, ranging from first-principles calculations, first-principles molecular dynamic simulations, and Calculation of Phase Diagram (CALPHAD) modeling to crystal plasticity finite element simulations coupled with knowledge graph, as well as experimental techniques, e.g., casting, powder metallurgy, additive manufacturing, etc. are discussed. Consequently, the diverse topics and state-of-the-art theoretical/experimental techniques will attract broad interest from materials researchers worldwide

    Knowledge visualizations: a tool to achieve optimized operational decision making and data integration

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    The overabundance of data created by modern information systems (IS) has led to a breakdown in cognitive decision-making. Without authoritative source data, commanders’ decision-making processes are hindered as they attempt to paint an accurate shared operational picture (SOP). Further impeding the decision-making process is the lack of proper interface interaction to provide a visualization that aids in the extraction of the most relevant and accurate data. Utilizing the DSS to present visualizations based on OLAP cube integrated data allow decision-makers to rapidly glean information and build their situation awareness (SA). This yields a competitive advantage to the organization while in garrison or in combat. Additionally, OLAP cube data integration enables analysis to be performed on an organization’s data-flows. This analysis is used to identify the critical path of data throughout the organization. Linking a decision-maker to the authoritative data along this critical path eliminates the many decision layers in a hierarchal command structure that can introduce latency or error into the decision-making process. Furthermore, the organization has an integrated SOP from which to rapidly build SA, and make effective and efficient decisions.http://archive.org/details/knowledgevisuali1094545877Outstanding ThesisOutstanding ThesisMajor, United States Marine CorpsCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

    Acta Cybernetica : Volume 25. Number 3.

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