cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
More on decomposing coverings by octants
Creators: name: Keszegh, Balázs
name: Pálvölgyi, Dömötör
Publisher: name: Journal of Computational Geometry
Year: 2015

description: $\newcommand{\R}{\mathbb{R}}$In this note we improve our upper bound given in [Keszegh and Pálvölgyi, 2012] by showing that every $9$-fold covering of a point set in $\R^3$ by finitely many translates of an octant decomposes into two coverings, and our lower bound by a construction for a $4$-fold covering that does not decompose into two coverings. The same bounds also hold for coverings of points in $\R^2$ by finitely many homothets or translates of a triangle. We also prove that certain dynamic interval coloring problems are equivalent to the above question.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
การพัฒนาชุดบอดี้สูทช่วยในการทรงท่าสําหรับเด็กสมองพิการชนิดอัมพาตครึ่งท่อนล่าง
Creators: name: พิธาลัย ผู้พัฒน์
Publisher: name: สถาบันวิจัยและพัฒนา มหาวิทยาลัยเทคโนโลยีราชมงคลธัญบุรี
Year: 2023
Subjects: children with cerebral palsy
bodysuit for body balance
textile product design
effectiveness of product

description: Journal of Applied Research on Science and Technology (JARST), 22, 1, 50-64
Sequential recombination algorithm for jet clustering and background subtraction
Creators: name: Tseng, Jeff
name: Evans, Hannah
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We investigate a new sequential recombination algorithm which effectively subtracts background as it reconstructs the jet. We examine the new algorithm's behavior in light of existing algorithms, and we find that in Monte Carlo comparisons, the new algorithm's robustness against collision backgrounds is comparable to that of other jet algorithms when the latter have been augmented by further background subtraction techniques.
description: 5 pages, 7 figures. Accepted version. Updated plots for adjusted algorithm (very small changes); shortened introduction
มูลค่าการกักเก็บคาร์บอนในพื้นที่เสื่อมโทรม จากการปลูกข้าวโพดโดยการฟื้นฟูด้วยระบบการปลูกไม้ 3 ชนิด เพื่อประโยชน์ 4 อย่าง จังหวัดน่าน
Creators: name: กฤษฎา ภาณุมนต์วาที
Publisher: name: สถาบันวิจัยและพัฒนา มหาวิทยาลัยเทคโนโลยีราชมงคลธัญบุรี
Year: 2023
Subjects: Carbon storage
Restoration
Carbon credit
Nan province

description: Journal of Applied Research on Science and Technology (JARST), 22, 1, 65-77
Roots of the Ehrhart polynomial of hypersimplices
Creators: name: Ohsugi, Hidefumi
name: Shibata, Kazuki
Publisher: name: arXiv
Year: 2013
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 52B20

description: The Ehrhart polynomial of the $d$-th hypersimplex $Δ(d,n)$ of order $n$ is studied. By computational experiments and a known result for $d=2$, we conjecture that the real part of every roots of the Ehrhart polynomial of $Δ(d,n)$ is negative and larger than $- \frac{n}{d}$ if $n \geq 2d$. In this paper, we show that the conjecture is true when $d=3$ and that every root $a$ of the Ehrhart polynomial of $Δ(d,n)$ satisfies $-\frac{n}{d} < {\rm Re} (a) < 1$ if $4 \leq d \ll n$.
description: 18 pages, 8 figures
Phase transitions of the q-state Potts model on multiply-laced Sierpinski gaskets
Creators: name: Tian, Liang
name: Ma, Hui
name: Guo, Wenan
name: Tang, Lei-Han
Publisher: name: arXiv
Year: 2013
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present an exact solution of the q-state Potts model on a class of generalized Sierpinski fractal lattices. The model is shown to possess an ordered phase at low temperatures and a continuous transition to the high temperature disordered phase at any q>=1. Multicriticality is observed in the presence of a symmetry-breaking field. Exact renormalization group analysis yields the phase diagram of the model and a complete set of critical exponents at various transitions.
description: 6 pages, 6 figures; figures corrected
The Lebesgue universal covering problem
Creators: name: Baez, John C.
name: Bagdasaryan, Karine
name: Gibbs, Philip
Publisher: name: Journal of Computational Geometry
Year: 2015

description: In 1914 Lebesgue defined a 'universal covering' to be a convex subset of the plane that contains an isometric copy of any subset of diameter 1. His challenge of finding a universal covering with the least possible area has been addressed by various mathematicians: Pál, Sprague and Hansen have each created a smaller universal covering by removing regions from those known before. However, Hansen's last reduction was microsopic: he claimed to remove an area of $6 \cdot 10^{-18}$, but we show that he actually removed an area of just $8 \cdot 10^{-21}$. In the following, with the help of Greg Egan, we find a new, smaller universal covering with area less than $0.8441153$. This reduces the area of the previous best universal covering by $2.2 \cdot 10^{-5}$.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
title: BIRTH MOTHERS’ EXPERIENCES OF SUPPORT BEFORE, DURING, AND AFTER ADOPTIVE PLACEMENT
Creators: name: Watkins, Ciara
Publisher: name: University of Kentucky Libraries
Year: 2021
Subjects: subject: FOS: Other social sciences
valueUri: http://www.oecd.org/science/inno/38235147.pdf

description: The current study explores the perceptions and experiences of support in a sample of birth mothers who relinquished parental rights though open or closed private adoption (e.g., religiously, and non-religiously affiliated private adoption agencies, adoption attorneys). Participants (N = 51) were birth mothers who placed a child for adoption at birth or within several months and who relinquished parenting rights 8 months to 50 years ago, with (M = 15.39) years since placement. A thematic analysis uncovered six overarching themes throughout the relinquishment process. Further, prevalence of themes in certain phases (i.e., pre-placement, during placement, post-placement) were shared among all participants. Reliability was strong for all themes. These findings hold important implications for policy and supports related to birth mothers’ well-being and adjustment.
description: © 2021 Ciara Watkins
Subquadratic medial-axis approximation in $\mathbb{R}^3$
Creators: name: Scheffer, Christian
name: Vahrenhold, Jan
Publisher: name: Journal of Computational Geometry
Year: 2015

description: We present an algorithm that approximates the medial axis of a smooth manifold in $\mathbb{R}^3$ which is given by a sufficiently dense point sample. The resulting, non-discrete approximation is shown to converge to the medial axis as the sampling density approaches infinity. While all previous algorithms guaranteeing convergence have a running time quadratic in the size $n$ of the point sample, we achieve a running time of at most $\mathcal{O}(n\log^3 n)$. While there is no subquadratic upper bound on the output complexity of previous algorithms for non-discrete medial axis approximation, the output of our algorithm is guaranteed to be of linear size.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
Forcing subarrangements in complete arrangements of pseudocircles
Creators: name: Ortner, Ronald
Publisher: name: Journal of Computational Geometry
Year: 2015

description: In arrangements of pseudocircles (i.e., Jordan curves) the weight of a vertex (i.e., an intersection point) is the number of pseudocircles that contain the vertex in its interior. We show that in complete arrangements (in which each two pseudocircles intersect) $2n-1$ vertices of weight 0 force an $\alpha$-subarrangement, a certain arrangement of three pseudocircles. Similarly, $4n-5$ vertices of weight 0 force an $\alpha^4$-subarrangement (of four pseudocircles). These results on the one hand give improved bounds on the number of vertices of weight $k$ for complete, $\alpha$-free and complete, $\alpha^4$-free arrangements. On the other hand, interpreting $\alpha$- and $\alpha^4$-arrangements as complete graphs with three and four vertices, respectively, the bounds correspond to known results in extremal graph theory.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
Ptolemaic indexing
Creators: name: Hetland, Magnus Lie
Publisher: name: Journal of Computational Geometry
Year: 2015

description: This paper discusses a new family of bounds for use in similarity search, related to those used in metric indexing, but based on Ptolemy's inequality, rather than the metric axioms. Ptolemy's inequality holds for the well-known Euclidean distance, but is also shown here to hold for quadratic form metrics in general, with Mahalanobis distance as an important special case. The inequality is examined empirically on both synthetic and real-world data sets and is also found to hold approximately, with a very low degree of error, for important distances such as the angular pseudometric and several Lp norms. Indexing experiments are performed on several data sets, demonstrating a highly increased filtering power when using certain forms of Ptolemaic filtering, compared to existing, triangular methods. It is also shown that combining the Ptolemaic and triangular filtering can lead to better results than using either approach on its own.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
title: Embedding circular principles into plastic packaging regulation in Australia: challenges and solutions
Creators: name: Bousags, Annastasia Louisa
Publisher: name: University of Southern Queensland
Year: 2021
Subjects: classificationCode: 480405
subject: Law and society and socio-legal research
valueUri: https://www.abs.gov.au/statistics/classifications/australian-and-new-zealand-standard-research-classification-anzsrc/latest-release
classificationCode: 480203
subject: Environmental law
valueUri: https://www.abs.gov.au/statistics/classifications/australian-and-new-zealand-standard-research-classification-anzsrc/latest-release
classificationCode: 480406
subject: Law reform
valueUri: https://www.abs.gov.au/statistics/classifications/australian-and-new-zealand-standard-research-classification-anzsrc/latest-release

description: The Circular Economy is an alternative economic model, focused on resource efficiency and regenerative systems, which aims to systematically alter society's patterns of natural resource use and waste generation in pursuit of sustainable production and consumption practices. Centered on generating material 'loops' through the recirculation of waste into further production cycles, the circular economy is dependent on the continuous re-use of materials from products that have been designed and manufactured for re-use, reparability, upgradability and recyclability. Given the weight afforded to product design within the literature, specifically the need for manufacturers to produce circular compatible products for the generation of material loops, this thesis proposes that a lack of appropriate regulatory interventions focused on start-of-life design of products, is a current legal barrier that hinders the transition toward a circular economy in Australia. To investigate possible mechanisms to overcome this barrier, this thesis utilizes a case study focused on plastic packaging, to establish a best practice approach to regulating manufacturers for improved circular plastic packaging. To demonstrate use, and application of the best practice approach, these principles will be then be employed to identify and review existing regulation that applies to manufacturers of plastic packaging in Australia. Application of these principles in this review, will establish not only an understanding of the ways in which manufactures are currently being regulated in Australia, but will also highlight potential regulatory gaps that may require attention in this area. Guided by the outcome of this review, this thesis will conclude by proposing a number of reform recommendations intended to improve these instruments in line with the proposed best practice approach in pursuit of a circular economy for plastic packaging in Australia.
AdS black holes, the bulk-boundary dictionary, and smearing functions
Creators: name: Leichenauer, Stefan
name: Rosenhaus, Vladimir
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In Lorentzian AdS/CFT there exists a mapping between local bulk operators and nonlocal CFT operators. In global AdS this mapping can be found through use of bulk equations of motion and allows the nonlocal CFT operator to be expressed as a local operator smeared over a range of positions and times. We argue that such a construction is not possible if there are bulk normal modes with exponentially small near boundary imprint. We show that the AdS-Schwarzschild background is such a case, with the horizon introducing modes with angular momentum much larger than frequency, causing them to be trapped by the centrifugal barrier. More generally, we argue that any barrier in the radial effective potential which prevents null geodesics from reaching the boundary will lead to modes with vanishingly small near boundary imprint, thereby obstructing the existence of a smearing function. While one may have thought the bulk-boundary dictionary for low curvature regions, such as the exterior of a black hole, should be as in empty AdS, our results demonstrate otherwise.
description: 25 pages, published version
"Van Mary" Finds Strength In Her Struggles
Creators: name: Anderson, Carys
Publisher: name: ORANGE Magazine
Year: 2019
Subjects: ORANGE - Pop Culture
Van Mary
musician
singer
music

description: She always wanted to be in a band, but things - family problems, toxic relationships, fear itself - kept getting in the way. Now, Emily Whetstone explores all of these things through Van Mary.
HOLA: a High-Order Lie Advection of Discrete Differential Forms With Applications in Fluid Dynamics
Creators: name: McKenzie, Alexander George
Publisher: name: California Institute of Technology
Year: 2007
Subjects: Vorticity advection
WENO
Lie derivative
Discrete differential forms
Computer Science

description: The Lie derivative, and Exterior Calculus in general, is ubiquitous in the elegant geometric interpretation of many dynamical systems. We extend recent trends towards a Discrete Exterior Calculus by introducing a discrete framework for the Lie derivative defined on differential forms, including a WENO based numerical scheme for its implementation. The usefulness of this operator is demonstrated through the advection of scalar and vector valued fields (arbitrary discrete k-forms) in a desirable intrinsic and metric independent fashion. Examples include Lie advection of fluid flow vorticity, and we conclude with a significant discussion on the conservative Lie advection of fluid mass density for robust free surface flows in computer graphics.
Parameter Estimation in Two-type Continuous-state Branching Processes with Immigration
Creators: name: Xu, Wei
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We study the estimation of two-type continuous-state branching processes with immigration (CBI-processes). The ergodicity of the processes is proved. We also establish the strong consistency and central limit theorems of the conditional least squares estimators and the weighted conditional least squares estimators of the drift and diffusion coefficients based on low frequency observations.
description: 13 pages
Random hyperplane search trees in high dimensions
Creators: name: Devroye, Luc
name: King, James
Publisher: name: Journal of Computational Geometry
Year: 2015

description: Given a set S of n ≥ d points in general position in Rd, a random hyperplane split is obtained by sampling d points uniformly at random without replacement from S and splitting based on their affine hull. A random hyperplane search tree is a binary space partition tree obtained by recursive application of random hyperplane splits. We investigate the structural distributions of such random trees with a particular focus on the growth with d. A blessing of dimensionality arises—as d increases, random hyperplane splits more closely resemble perfectly balanced splits; in turn, random hyperplane search trees more closely resemble perfectly balanced binary search trees. We prove that, for any fixed dimension d, a random hyperplane search tree storing n points has height at most (1 + O(1/sqrt(d))) log2 n and average element depth at most (1 + O(1/d)) log2 n with high probability as n → ∞. Further, we show that these bounds are asymptotically optimal with respect to d.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
Black Romance Revived: ‘The Photograph’ Reminds Us That Representation Matters
Creators: name: Akinnibosun, Gloria
Publisher: name: ORANGE Magazine
Year: 2020
Subjects: ORANGE - Pop Culture
movie
review
romance
Black
representation

description: Love and intimacy are without a doubt intrinsic to the overall human experience. Everyone craves love whether seldom or often, and most of the time, people often bare an ever-longing desire to see their wishful romances mirrored in cinematic dramas.
title: A Pilot Study Using Graded Yellow Mealworm (Tenebrio molitor) Meal in Formulated Diets for Growth Performance of Black Sea Bass (Centropristis striata)
Creators: name: Redman, Dylan H.
name: Nelson, David A.
name: Roy, John
name: Goldberg, Ronald 1952-
name: Scott, Thomas M.
name: Rust, Michael B.
name: Mercaldo-Allen, Renee
Publisher: name: United States. National Marine Fisheries Service. Northeast Fisheries Science Center (U.S.)
Year: 2019

description: NOAA technical memorandum NMFS NE ; 253
title: Common Bottlenose Dolphin (Tursiops truncatus) Gillnet Bycatch Estimates along the US mid-Atlantic Coast, 2007-2015
Creators: name: Lyssikatos, Marjorie C.
name: Garrison, Lance Preston 1970-
Publisher: name: United States. National Marine Fisheries Service. Northeast Fisheries Science Center (U.S.)
Year: 2018

description: Northeast Fisheries Science Center reference document ; 18-07
Vortex lattices in three-component Bose-Einstein condensates under rotation: simulating colorful vortex lattices in a color superconductor
Creators: name: Cipriani, Mattia
name: Nitta, Muneto
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study vortex lattices in three-component BECs under rotation, where three kinds of fractional vortices winding one of three components are present. Unlike the cases of two-component BECs where the phases of square and triangular lattices are present depending on the intercomponent coupling constant and the rotation speed, we find triangular ordered "colorful" vortex lattices where three kind of fractional vortices are placed in order without defects, in all parameter region where the inter-component coupling g' is less than the intra-component coupling g. When g > g' on the other hand, we find the phase separation; In a region where one component is present, the other two components must vanish, where we find ghost vortices in these two components whose positions are separated. In the boundary g = g', the accidental U(3) symmetry is present, in which case two vortices in different components are close to each other in some regions.
description: 8 pages, 5 figures
Algorithms for ball hulls and ball intersections in normed planes
Creators: name: Martín, Pedro
name: Martini, Horst
Publisher: name: Journal of Computational Geometry
Year: 2015

description: Extending results of Hershberger and Suri for the Euclidean plane, we show that ball hulls and ball intersections of sets of $n$ points in normed planes can be constructed in $O(n \log n)$ time. In addition, we confirm that the 2-center problem with constrained circles for arbitrary normed planes can be solved in $O(n^2)$ time. Some ideas about the geometric structure of the ball hull in a normed plane are also presented.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
Sweet Pandemic Distractions: Baking Magic with “The Great British Bake Off”
Creators: name: Pratt, Mackenzie
Publisher: name: ORANGE Magazine
Year: 2020
Subjects: ORANGE - Pop Culture
The Great British Bake Off
baking
pandemic
COVID-19

description: Baking can be a bright spot in your day. Creating something sweet for yourself or your friends can spread happiness and spark your creativity. And there’s nothing better than a new season of “The Great British Bake Off” to ‘preheat’ that baking mood.
Deep learning-enhanced chemiluminescence vertical flow assay for high-sensitivity cardiac troponin I testing
Creators: name: Han, Gyeo-Re
name: Goncharov, Artem
name: Eryilmaz, Merve
name: Ye, Shun
name: Joung, Hyou-Arm
name: Ghosh, Rajesh
name: Ngo, Emily
name: Tomoeda, Aoi
name: Lee, Yena
name: Ngo, Kevin
name: Melton, Elizabeth
name: Garner, Omai B.
name: Di Carlo, Dino
name: Ozcan, Aydogan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Medical Physics (physics.med-ph)
subject: Applied Physics (physics.app-ph)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: Democratizing biomarker testing at the point-of-care requires innovations that match laboratory-grade sensitivity and precision in an accessible format. Here, we demonstrate high-sensitivity detection of cardiac troponin I (cTnI) through innovations in chemiluminescence-based sensing, imaging, and deep learning-driven analysis. This chemiluminescence vertical flow assay (CL-VFA) enables rapid, low-cost, and precise quantification of cTnI, a key cardiac protein for assessing heart muscle damage and myocardial infarction. The CL-VFA integrates a user-friendly chemiluminescent paper-based sensor, a polymerized enzyme-based conjugate, a portable high-performance CL reader, and a neural network-based cTnI concentration inference algorithm. The CL-VFA measures cTnI over a broad dynamic range covering six orders of magnitude and operates with 50 uL of serum per test, delivering results in 25 min. This system achieves a detection limit of 0.16 pg/mL with an average coefficient of variation under 15%, surpassing traditional benchtop analyzers in sensitivity by an order of magnitude. In blinded validation, the computational CL-VFA accurately measured cTnI concentrations in patient samples, demonstrating a robust correlation against a clinical-grade FDA-cleared analyzer. These results highlight the potential of CL-VFA as a robust diagnostic tool for accessible, rapid cardiac biomarker testing that meets the needs of diverse healthcare settings, from emergency care to underserved regions.
description: 24 Pages, 4 Figures
Trajectory grouping structure
Creators: name: Buchin, Kevin
name: Buchin, Maike
name: Kreveld, Marc Van
name: Speckmann, Bettina
name: Staals, Frank
Publisher: name: Journal of Computational Geometry
Year: 2015

description: The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial, algorithmic, and experimental results.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
More on the N=2 superconformal systems of type $D_p(G)$
Creators: name: Cecotti, Sergio
name: Del Zotto, Michele
name: Giacomelli, Simone
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A large family of 4d N=2 SCFT's was introduced in arXiv:1210.2886. Its elements $D_p(G)$ are labelled by a positive integer p\in N and a simply-laced Lie group G; their flavor symmetry is at least G. In the present paper we study their physics in detail. We also analyze the properties of the theories obtained by gauging the diagonal symmetry of a collection of $D_{p_i}(G)$ models. In all cases the computation of the physical quantities reduces to simple Lie-theoretical questions. To make the analysis more functorial, we replace the notion of the BPS-quiver of the N=2 QFT by the more intrinsic concept of its META-quiver. In particular: 1) We compute the SCFT central charges a, c, k, and flavor group F for all $D_p(G)$ models. 2) We identify the subclass of $D_p(G)$ theories which correspond to previously known SCFT's (linear SU and SO-USp quiver theories, Argyres-Douglas models, superconformal gaugings of Minahan-Nemeshanski E_r models, etc.), as well as to non-trivial IR fixed points of known theories. The $D_p(E_r)$ SCFT's with $p\geq 3$ cannot be constructed by any traditional method. 3) We investigate the finite BPS chambers of some of the models. 4) As a by product, we prove three conjectures by Xie and Zhao, and provide new checks of the Argyres-Seiberg duality.
description: 73 pages, 8 figures, 4 tables; argument clarified and one example added; additional references
Induced matchings and the algebraic stability of persistence barcodes
Creators: name: Bauer, Ulrich
name: Lesnick, Michael
Publisher: name: Journal of Computational Geometry
Year: 2015

description: $\DeclareMathOperator{\ker}{ker}\DeclareMathOperator{\coker}{coker}$We define a simple, explicit map sending a morphism $f\colon M\to N$ of pointwise finite dimensional persistence modules to a matching between the barcodes of $M$ and $N$. Our main result is that, in a precise sense, the quality of this matching is tightly controlled by the lengths of the longest intervals in the barcodes of $\ker f$ and $\coker f$. As an immediate corollary, we obtain a new proof of the algebraic stability theorem for persistence barcodes, a fundamental result in the theory of persistent homology. In contrast to previous proofs, ours shows explicitly how a $\delta$-interleaving morphism between two persistence modules induces a $\delta$-matching between the barcodes of the two modules. Our main result also specializes to a structure theorem for submodules and quotients of persistence modules, and yields a novel “single-morphism” characterization of the interleaving relation on persistence modules.
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
Phase transitions of magnetic AdS4 black holes with scalar hair
Creators: name: Hristov, Kiril
name: Toldo, Chiara
name: Vandoren, Stefan
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We determine the thermodynamic properties of a class of spherically symmetric and static black holes in AdS4 with magnetic charges and scalar hair. These black holes are solutions in 4d N=2 gauged supergravity that can arise from eleven-dimensional supergravity compactified on S^7. At zero temperature, they preserve supersymmetry and hence are stable. At non-zero temperatures, we explore in detail the canonical ensemble and stability of solutions and find a first order phase transition between small and large hairy black holes. The transition emerges as a liquid-gas phase transition in the dual three-dimensional field theory on R x S^2 with magnetic flux through S^2.
description: 5 pages, v2: misprints corrected and references added, published version
Guest Editors' Foreword
Creators: name: Cheng, Siu-Wing
name: Devillers, Olivier
Publisher: name: Journal of Computational Geometry
Year: 2015

description: The Annual Symposium on Computational Geometry has a special issue in the Journal of Computational Geometry for the first time.
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
Insights into the Properties of Type Ibn/Icn Supernovae and Their Progenitor Channels through X-ray Emission
Creators: name: Inoue, Yusuke
name: Maeda, Keiichi
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Type Ibn/Icn supernovae (SNe Ibn/Icn), which are characterized by narrow helium or carbon lines originated in hydrogen-poor dense circumstellar medium (CSM), provide new insights into the final evolution of massive stars. While SNe Ibn/Icn are expected to emit strong X-rays through the strong SN-CSM interaction, the X-ray emission modeling effort has been limited so far. In the present study, we provide broad-band X-ray light curve (LC) predictions for SNe Ibn/Icn. We find that the soft X-ray LC provides information about the CSM compositions, while the hard X-ray LC is a robust measure of the CSM density, the explosion energy, and the ejecta mass. In addition, considering the evolution of the ionization state in the unshocked CSM, a bright soft X-ray is expected in the first few days since the explosion, which encourages rapid X-ray follow-up observations as a tool to study the nature of SNe Ibn/Icn. Applying our model to the soft X-ray LCs of SNe Ibn 2006jc and 2022ablq, we derive that the CSM potentially contains a larger fraction of carbon and oxygen for SN 2006jc than 2022ablq, highlighting the power of the soft X-ray modeling to address the nature of the CSM. We also discuss detectability and observational strategy, with which the currently operating telescopes such as NuSTAR and Swift can offer an irreplaceable opportunity to explore the nature of these enigmatic rapid transients and their still-unclarified progenitor channel(s).
description: 18 pages, 17 figures, accepted to ApJ
The Comeback of Robert Pattinson
Creators: name: Cardenas, Cat
Publisher: name: ORANGE Magazine
Year: 2020
Subjects: ORANGE - Pop Culture
Robert Pattison
actor

description: “Twilight”’s 2008 release was met with swooning audiences captivated by the portrayal of the brooding, but sparkly and ripped vampire, Edward Cullen. The role instantly catalyzed Robert Pattinson’s rise to global celebrity crush status for almost half a decade.
The maximum number of faces of the Minkowski sum of three convex polytopes
Creators: name: Karavelas, Menelaos
name: Konaxis, Christos
name: Tzanaki, Eleni
Publisher: name: Journal of Computational Geometry
Year: 2015

description: We derive tight expressions for the maximum number of $k$-faces, $0\le{}k\le{}d-1$, of the Minkowski sum, $P_1+P_2+P_3$, of three $d$-dimensional convex polytopes $P_1$, $P_2$ and $P_3$ in $\mathbb{R}^d$, as a function of the number of vertices of the polytopes, for any $d\ge{}2$. Expressing the Minkowski sum as a section of the Cayley polytope $\mathcal{C}$ of its summands, counting the $k$-faces of $P_1+P_2+P_3$ reduces to counting the $(k+2)$-faces of $\mathcal{C}$ that contain vertices from each of the three polytopes. In two dimensions our expressions reduce to known results, while in three dimensions, the tightness of our bounds follows by exploiting known tight bounds for the number of faces of $r$ $d$-polytopes in $\mathbb{R}^d$, where $r\ge d$. For $d\ge{}4$, the maximum values are attained when $P_1$, $P_2$ and $P_3$ are $d$-polytopes, whose vertex sets are chosen appropriately from three distinct $d$-dimensional moment-like curves.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
Sampling with removal in LP-type problems
Creators: name: Gärtner, Bernd
Publisher: name: Journal of Computational Geometry
Year: 2015

description: Random sampling is an important tool in optimization subject to finitely or infinitely many constraints. Here we are interested in obtaining solutions of low cost that violate only few constraints. Under convexity or similar favorable conditions, and assuming fixed dimension, one can indeed derive combinatorial bounds on the expected number (or probability mass) of constraints violated by the optimal solution subject to a (small) random sample of constraints. The cost of the sample solution, however, cannot be bounded combinatorially. Suppose that after picking the sample, we remove $k$ constraints from it in such a way that the best improvement of objective function is achieved. Can we still guarantee (good) bounds on the number or mass of violated constraints? This question was asked and partially answered in the framework of chance-constrained optimization. Here we study the question in the completely combinatorial setting LP-type problems, which allows a unified treatment of many different optimization problems. Given a nondegenerate LP-type problem of combinatorial dimension $\delta$, we consider sampling with subsequent removal of the $k$ constraints that lead to the best improvement of objective function. We show that this induces an LP-type problem of combinatorial dimension $O(\delta^{k+1})$, and that this bound is tight in the worst case. It follows that through this kind of removal, the expected number of violated constraints blows up by a factor of at most $O(\delta^{k})$; for relevant sample sizes, however, a matching lower bound for the blowup factor is not implied. At the same time, our results show that further improvements require new tools that go beyond combinatorial dimension.
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
SPRec: Self-Play to Debias LLM-based Recommendation
Creators: name: Gao, Chongming
name: Chen, Ruijun
name: Yuan, Shuai
name: Huang, Kexin
name: Yu, Yuanqing
name: He, Xiangnan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Large language models (LLMs) have attracted significant attention in recommendation systems. Current work primarily applies supervised fine-tuning (SFT) to adapt the model for recommendation tasks. However, SFT on positive examples only limits the model's ability to align with user preference. To address this, researchers recently introduced Direct Preference Optimization (DPO), which explicitly aligns LLMs with user preferences using offline preference ranking data. However, we found that DPO inherently biases the model towards a few items, exacerbating the filter bubble issue and ultimately degrading user experience.
 In this paper, we propose SPRec, a novel self-play framework designed to mitigate over-recommendation and improve fairness without requiring additional data or manual intervention. In each self-play iteration, the model undergoes an SFT step followed by a DPO step, treating offline interaction data as positive samples and the predicted outputs from the previous iteration as negative samples. This effectively re-weights the DPO loss function using the model's logits, adaptively suppressing biased items. Extensive experiments on multiple real-world datasets demonstrate SPRec's effectiveness in enhancing recommendation accuracy and fairness. The implementation is available via https://github.com/RegionCh/SPRec
description: Accepted by WWW 2025
On a conjecture of Lovász on circle-representations of simple 4-regular planar graphs
Creators: name: Bekos, Michael A
name: Raftopoulou, Chrysanthi N
Publisher: name: Journal of Computational Geometry
Year: 2015

description: Lovász conjectured that every connected 4-regular planar graph $G$ admits a realization as a system of circles, i.e., it can be drawn on the plane utilizing a set of circles, such that the vertices of $G$ correspond to the intersection and touching points of the circles and the edges of $G$ are the arc segments among pairs of intersection and touching points of the circles. In this paper, we settle this conjecture. In particular, (a) we first provide tight upper and lower bounds on the number of circles needed in a realization of any simple 4-regular planar graph, (b) we affirmatively answer Lovász's conjecture, if $G$ is 3-connected, and, (c) we demonstrate an infinite class of simple connected 4-regular planar graphs which are not 3-connected (i.e., either simply connected or biconnected) and do not admit realizations as a system of circles.
description: Journal of Computational Geometry, Vol. 6 No. 1 (2015)
The signature of the Warm Hot Intergalactic Medium in WMAP and the forthcoming PLANCK data
Creators: name: Suarez-Velásquez, I.
name: Kitaura, F. -S.
name: Atrio-Barandela, F.
name: Muecket, J. P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We compute the cross-correlation between the Warm-Hot Intergalactic Medium and maps of Cosmic Microwave Background temperature anisotropies using a log-normal probability density function to describe the weakly non-linear matter density field. We search for this contribution in the data measured by the Wilkinson Microwave Anisotropy Probe. We use a template of projected matter density reconstructed from the Two-Micron All-Sky Redshift Survey as a tracer of the electron distribution. The spatial distribution of filaments is modeled using the recently developed Augmented Lagrangian Perturbation Theory. On the scales considered here, the reconstructed density field is very well described by the assumed log-normal distribution function. We predict that the cross-correlation will have an amplitude of $0.03-0.3μ$K. The measured value is close to $1.5μ$K, compatible with random alignments between structure in the template and in the temperature anisotropy data. Using the W1 Differencing Assembly to remove this systematic gives a residual correlation dominated by Galactic foregrounds. Planck could detect the Warm-Hot Medium if it is well traced by the density field reconstructed from galaxy surveys. The 217GHz channel will allow to eliminate spurious contributions and its large frequency coverage can show the sign change from the Rayleigh-Jeans to the Wien part of the spectrum, characteristic of the thermal Sunyaev-Zeldovich effect.
description: ApJ, in press. Matches the published version
Progressive geometric algorithms
Creators: name: Alewijnse, Sander P.A.
name: Bagautdinov, Timur M.
name: De Berg, Mark
name: Bouts, Quirijn W.
name: Ten Brink, Alex P.
name: Buchin, Kevin
name: Westenberg, Michel A.
Publisher: name: Journal of Computational Geometry
Year: 2015

description: Progressive algorithms are algorithms that, on the way to computing a complete solution to the problem at hand, output intermediate solutions that approximate the complete solution increasingly well. We present a framework for analyzing such algorithms, and develop efficient progressive algorithms for two geometric problems: computing the convex hull of a planar point set, and finding popular places in a set of trajectories.
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
The Canonical Structure of the First Order Einstein-Hilbert Action with a Flat Background
Creators: name: Chishtie, Farrukh
name: McKeon, D. G. C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It has been shown that the canonical structure of the first order Einstein-Hilbert (1EH) action involves three generations of constraints and that these can be used to find the generator of a gauge transformation which leaves the action invariant; this transformation is a diffeomorphism with field-dependent gauge function while on shell. In this paper we examine the relationship between the canonical structure of this action and that of the first order spin-2 (1S2) action, which is the weak field limit of the Einstein-Hilbert action. We find that the weak field limit of the Possion Brackets (PB) algebra of first class constraints associated with the 1EH action is not that of the 1S2 action.
description: 9 pages, LaTeX2e, published version
New and improved spanning ratios for Yao graphs
Creators: name: Barba, Luis
name: Bose, Prosenjit
name: Damian, Mirela
name: Fagerberg, Rolf
name: Keng, Wah Loon
name: O'Rourke, Joseph
name: Van Renssen, André
name: Taslakian, Perouz
name: Verdonschot, Sander
name: Xia, Ge
Publisher: name: Journal of Computational Geometry
Year: 2015

description: For a set of points in the plane and a fixed integer $k > 0$, the Yao graph $Y_k$ partitions the space around each point into $k$ equiangular cones of angle $\theta=2\pi/k$, and connects each point to a nearest neighbor in each cone. It is known for all Yao graphs, with the sole exception of $Y_5$, whether or not they are geometric spanners. In this paper we close this gap by showing that for odd $k \geq 5$, the spanning ratio of $Y_k$ is at most $1/(1-2\sin(3\theta/8))$, which gives the first constant upper bound for $Y_5$, and is an improvement over the previous bound of $1/(1-2\sin(\theta/2))$ for odd $k \geq 7$. We further reduce the upper bound on the spanning ratio for $Y_5$ from $10.9$ to \mbox{$2+\sqrt{3} \approx 3.74$}, which falls slightly below the lower bound of $3.79$ established for the spanning ratio of $\Theta_5$ ($\Theta$-graphs differ from Yao graphs only in the way they select the closest neighbor in each cone). This is the first such separation between a Yao and $\Theta$-graph with the same number of cones. We also give a lower bound of $2.87$ on the spanning ratio of $Y_5$. In addition, we revisit the $Y_6$ graph, which plays a particularly important role as the transition between the graphs ($k > 6$) for which simple inductive proofs are known, and the graphs ($k \le 6$) whose best spanning ratios have been established by complex arguments. Here we reduce the known spanning ratio of $Y_6$ from $17.6$ to $5.8$, getting closer to the spanning ratio of 2 established for $\Theta_6$. Finally, we present the first lower bounds on the spanning ratio of Yao graphs with more than six cones, and a construction that shows that the Yao-Yao graph (a bounded-degree variant of the Yao graph) with five cones is not a spanner.
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
High performance fiber-coupled NbTiN superconducting nanowire single photon detectors with Gifford-McMahon cryocooler
Creators: name: Miki, Shigehito
name: Yamashita, Taro
name: Terai, Hirotaka
name: Wang, Zhen
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Superconductivity (cond-mat.supr-con)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present high performance fiber-coupled niobium titanium nitride superconducting nanowire single photon detectors fabricated on thermally oxidized silicon substrates. The best device showed a system detection efficiency (DE) of 74%, dark count rate of 100 c/s, and full width at half maximum timing jitter of 68 ps under a bias current of 18.0 uA with a practical Gifford-McMahon cryocooler system. We also introduced six detectors into the cryocooler and confirmed that the system DE of all detectors was higher than 67% at the dark count rate of 100 c/s.
description: 10 pages, 3 figures, 1 table
Finding the largest disk containing a query point in logarithmic time with linear storage
Creators: name: Kaminker, Tal
name: Sharir, Micha
Publisher: name: Journal of Computational Geometry
Year: 2014

description: Let D be a set of n disks in the plane. We present a data structure of size O(n) that can compute, for any query point q, the largest disk in D that contains q, in O(log n) time. The structure can be constructed in O(n log3 n) time. The optimal storage and query time of the structure improve several recent results on this and related problems
description: Journal of Computational Geometry, Vol. 6 No. 2 (2015): Special issue of Selected Papers from SoCG 2014
Computing the maximum detour of a plane geometric graph in subquadratic time
Creators: name: Wulff-Nilsen, Christian
Publisher: name: Journal of Computational Geometry
Year: 2010

description: Let G be a plane geometric graph where each edge is a line segment. We consider the problem of computing the maximum detour of G, defined as the maximum over all pairs of distinct points (vertices as well as interior points of edges) p and q of G of the ratio between the distance between p and q in G and the Euclidean distance ||pq||2. The fastest known algorithm for this problem has Θ(n2) running time where n is the number of vertices. We show how to obtain O(n3/2(log n)3) expected running time. We also show that if G has bounded treewidth, its maximum detour can be computed in O(n(log n)3) expected time.
description: Journal of Computational Geometry, Vol. 1 No. 1 (2010)
Origami-based spintronics in graphene
Creators: name: Costa, A. T.
name: Ferreira, M. S.
name: Hallam, Toby
name: Duesberg, Georg S.
name: Neto, A. H. Castro
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that periodically folded graphene sheets with enhanced spin-orbit interaction due to curvature effects can carry spin polarized currents and have gaps in the electronic spectrum in the presence of weak magnetic fields. Our results indicate that such origami-like structures can be used efficiently in spintronic applications.
Infinite ensemble learning with support vector machines
Creators: name: Lin, Hsuan-Tien
Publisher: name: California Institute of Technology
Year: 2005
Subjects: Kernel method
large margin classifier
support vector machine
ensemble learning
boosting
Computer Science

description: Ensemble learning algorithms such as boosting can achieve better performance by averaging over the predictions of base learners. However, existing algorithms are limited to combining only a finite number of base learners, and the generated ensemble is usually sparse. It is not clear whether we should construct an ensemble classifier with a larger or even an infinite number of base learners.

In addition, constructing an infinite ensemble itself is a challenging task. In this paper, we formulate an infinite ensemble learning framework based on SVM. The framework could output an infinite and nonsparse ensemble, and can be applied to construct new kernels for SVM as well as to interpret existing ones. We demonstrate the framework with a concrete application, the stump kernel, which embodies infinitely many decision stumps. The stump kernel is simple, yet powerful.

Experimental results show that SVM with the stump kernel usually achieves better performance than boosting, even with noisy data.