cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Planetary Nebula Luminosity Function at the Dawn of Gaia
Creators: name: Ciardullo, Robin
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The [O III] 5007 Planetary Nebula Luminosity Function (PNLF) is an excellent extragalactic standard candle. In theory, the PNLF method should not work at all, since the luminosities of the brightest planetary nebulae (PNe) should be highly sensitive to the age of their host stellar population. Yet the method appears robust, as it consistently produces < 10% distances to galaxies of all Hubble types, from the earliest ellipticals to the latest-type spirals and irregulars. It is therefore uniquely suited for cross-checking the results of other techniques and finding small offsets between the Population I and Population II distance ladders. We review the calibration of the method and show that the zero points provided by Cepheids and the Tip of the Red Giant Branch are in excellent agreement. We then compare the results of the PNLF with those from Surface Brightness Fluctuation measurements, and show that, although both techniques agree in a relative sense, the latter method yields distances that are ~15% larger than those from the PNLF. We trace this discrepancy back to the calibration galaxies and argue that, due to a small systematic error associated with internal reddening, the true distance scale likely falls between the extremes of the two methods. We also demonstrate how PNLF measurements in the early-type galaxies that have hosted Type Ia supernovae can help calibrate the SN Ia maximum magnitude-rate of decline relation. Finally, we discuss how the results from space missions such as Kepler and Gaia can help our understanding of the PNLF phenomenon and improve our knowledge of the physics of local planetary nebulae.
description: 12 pages, invited review at the conference "The Fundamental Cosmic Distance Scale: State of the Art and Gaia Perspective", to appear in Astrophysics and Space Science
Verifying Accountability for Unbounded Sets of Participants
Creators: name: Morio, Kevin
name: Künnemann, Robert
Publisher: name: CISPA
Year: 2023

description: Little can be achieved in the design of security protocols without trusting at least some participants. This trust should be justified or, at the very least, subject to examination. One way to strengthen trustworthiness is to hold parties accountable for their actions, as this provides a strong incentive to refrain from malicious behavior. This has led to an increased interest in accountability in the design of security protocols. In this work, we combine the accountability definition of Künnemann et al. with the notion of case tests to extend its applicability to protocols with unbounded sets of participants. We propose a general construction of verdict functions and a set of verification conditions that achieve soundness and completeness. Expressing the verification conditions in terms of trace properties allows us to extend Tamarin---a protocol verification tool---with the ability to analyze and verify accountability properties in a highly automated way. In contrast to prior work, our approach is significantly more flexible and applicable to a wider range of protocols.
On a generalization of the Blaschke-Lebesgue theorem for disk-polygons
Creators: name: Bezdek, Máté
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: In this paper we prove an extension of the Blaschke-Lebesgue theorem for a family of convex domains called disk-polygons. Also, this provides yet another new proof of the Blaschke-Lebesgue theorem.
description: Contributions to Discrete Mathematics, Vol 6, No 1 (2011)
Financial Well-Being of Farm Operators and Their Households
Creators: name: Ahearn, Mary
name: Ahearn, Mary
Publisher: name: Unknown
Year: 1986
Subjects: subject: Consumer/Household Economics
subject: Financial Economics
subject: Farm operator households
subject: distribution of income
subject: wealth
subject: Farm Costs and Returns Survey
subject: farm-nonfarm comparison

description: Almost a sixth of all U.S. farming households suffered net income losses in 1984 while about a ninth had total incomes of more than $60,000. This disparity in a relatively high income year for the agricultural sector as a whole demonstrates the importance of income distribution in determining the overall financial well-being of farm operators and their households. Most of the average farming household's income earned on the farm came in the form of the rental value of farm dwellings, home consumption of farm-produced food, and wages and benefits operators paid themselves and their households. In 1984, about three-fifths of the total income earned by farming households came from off-farm sources.
Atomic-scale effects behind structural instabilities in Si lamellae during ion beam thinning
Creators: name: Holmström, Eero
name: Kotakoski, Jani
name: Lechner, Lorenz
name: Kaiser, Ute
name: Nordlund, Kai
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The rise of nanotechnology has created an ever-increasing need to probe structures on the atomic scale, to which transmission electron microscopy has largely been the answer. Currently, the only way to efficiently thin arbitrary bulk samples into thin lamellae in preparation for this technique is to use a focused ion beam (FIB). Unfortunately, the established FIB thinning method is limited to producing samples of thickness above ~20 nm. Using atomistic simulations alongside experiments, we show that this is due to effects from finite ion beam sharpness at low milling energies combined with atomic-scale effects at high energies which lead to shrinkage of the lamella. Specifically, we show that attaining thickness below 26 nm using a milling energy of 30 keV is fundamentally prevented by atomistic effects at the top edge of the lamella. Our results also explain the success of a recently proposed alternative FIB thinning method, which is free of the limitations of the conventional approach due to the absence of these physical processes.
A variant of the bipartite relation theorem and its application to clique graphs
Creators: name: Kawamura, Kazuhiro
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: We consider a homological variant of the Bipartite

Relation Theorem (\cite{bjorner}) in the context of the flag complex of the square of a bipartite graph 

(\cite{lpvf}). We apply the results to study the homology and homotopy groups of the flag complexes of clique graphs.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
Characterization of the Derlin protein, CUP-2, in promoting stem cell proliferation in the C. elegans germ line
Creators: name: Singh, Ramya
Publisher: name: Graduate Studies
Year: 2018
Subjects: subject: C. elegans
subject: Developmental Biology
subject: Biology--Cell
subject: Genetics
subject: FOS: Biological sciences
subject: Biology--Molecular

description: Understanding of how tissue homeostasis is maintained is not only essential for furthering our understanding of a fundamental area in Biology, but also has important implications for regenerative medicine and the design of therapeutics for human health. The germline of the C. elegans nematode serves as an excellent model to study adult stem cells and how the balance between proliferation and differentiation is maintained in this vital tissue. GLP-1/Notch signalling is the principal pathway that promotes proliferation of Germline Stem Cells (GSCs) in this system. In this thesis, the role of a Derlin (Degradation in the ER) protein, CUP-2, in promoting GLP-1/Notch signalling-mediated proliferation of GSCs is presented. Reducing cup-2 activity strongly suppresses germline tumours caused by increased Notch signalling. However, cup-2(0) is unable to suppress Notch-independent germline tumours, which suggests that cup-2 promotes Notch signalling specifically and not cell proliferation in general. This is further supported by cup-2’s ability to influence the expression of a read-out for Notch signalling, SYGL-1. The cup-2 gene was tagged using CRISPR/Cas9 editing with an epitope tag and CUP-2 was found to be expressed in the germ line, which is consistent with its role in promoting Notch signalling. The ability of cup-2 to promote GLP-1/Notch signalling likely represents a conserved function, since der-2, a Derlin homolog, was also found to contribute to the development of Notch-dependent germ line tumours. In fact, cup-2 and der-2 appear to additively promote GLP-1/Notch signalling. Derlin proteins are known to function in Endoplasmic Reticulum-Associated Degradation (ERAD) of proteins. Therefore, this work sheds light on the importance of ERAD in maintaining the balance between proliferation and differentiation in stem cells. Investigation into the mechanism by which cup-2 promotes GLP-1/Notch signalling led to the discovery that cup-2 is involved in anchoring the niche cell, the Distal Tip Cell, in place in the aging gonad. This is a novel phenotype not reported before in the literature. The CRISPR/Cas9 tagged cup-2 alleles developed as part of this thesis could serve as a useful reagent for further studies in determining the mechanism by which cup-2 promotes GLP-1/Notch signalling.
Causality-Based Game Solving
Creators: name: Baier, Christel
name: Coenen, Norine
name: Finkbeiner, Bernd
name: Funke, Florian
name: Jantsch, Simon
name: Siber, Julian
Publisher: name: CISPA
Year: 2023

description: We present a causality-based algorithm for solving two-player reachability games represented by logical constraints. These games are a useful formalism to model a wide array of problems arising, e.g., in program synthesis. Our technique for solving these games is based on the notion of subgoals, which are slices of the game that the reachability player necessarily needs to pass through in order to reach the goal. We use Craig interpolation to identify these necessary sets of moves and recursively slice the game along these subgoals. Our approach allows us to infer winning strategies that are structured along the subgoals. If the game is won by the reachability player, this is a strategy that progresses through the subgoals towards the final goal; if the game is won by the safety player, it is a permissive strategy that completely avoids a single subgoal. We evaluate our prototype implementation on a range of different games. On multiple benchmark families, our prototype scales dramatically better than previously available tools.
Global Feed-Forward Vibration Isolation in a km scale Interferometer
Creators: name: DeRosa, Ryan
name: Driggers, Jennifer C
name: Atkinson, Dani
name: Miao, Haixing
name: Frolov, Valery
name: Landry, Michael
name: Giaime, Joseph
name: Adhikari, Rana X.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Using a network of seismometers and sets of optimal filters, we implemented a feed-forward control technique to minimize the seismic contribution to multiple interferometric degrees of freedom of the LIGO interferometers. The filters are constructed by using the Levinson-Durbin recursion relation to approximate the optimal Wiener filter. By reducing the RMS of the interferometer feedback signals below \sim10 Hz, we have improved the stability and duty cycle of the joint network of gravitational wave detectors. By suppressing the large control forces and mirror motions, we have dramatically reduced the rate of non-Gaussian transients in the gravitational wave signal stream.
description: 7 pages
Media construction of Japanese Canadian redress: a case study of the "Globe and Mail's" news discourses
Creators: name: Yato, Shiro
Publisher: name: University of Calgary
Year: 2006

description: Bibliography: p. 136-144
description: This thesis examines how mainstream Canadian media, The Globe and Mail in particular, interpreted and represented Japanese Canadian redress. This study analysed eight articles published in The Globe and Mail from 1984 to 1988 using three­dimensional discourse analysis as proposed by Norman Fairclough (1992). This study attempts to deconstruct the media's construction of the redress negotiations and provide an alternative way of understanding the redress. From the perspective of constructivist structuralism, discourse is theorised as social practice. Discourse is conditioned by social .structure and, at the same time, contributes to transforming the conditions of social reproduction. This study finds that The Globe and Mail endorsed the redress campaign and presented the redress as an improvement in ethnic minority rights. However, it also constructed Japanese Canadians as "racial Others." The study reveals the complexity of the media's role in reproducing and transforming power relations in society.
CapablePtrs: Securely Compiling Partial Programs Using the Pointers-as-Capabilities Principle
Creators: name: El-Korashy, Akram
name: Tsampas, Stelios
name: Patrignani, Marco
name: Devriese, Dominique
name: Garg, Deepak
name: Piessens, Frank
Publisher: name: CISPA
Year: 2023

description: Capability machines such as CHERI provide memory capabilities that can be used by compilers to provide security benefits for compiled code (e.g., memory safety). The existing C to CHERI compiler, for example, achieves memory safety by following a principle called “pointers as capabilities” (PAC). Informally, PAC says that a compiler should represent a source language pointer as a machine code capability. But the security properties of PAC compilers are not yet well understood. We show that memory safety is only one aspect, and that PAC compilers can provide significant additional security guarantees for partial programs: the compiler can provide security guarantees for a compilation unit, even if that compilation unit is later linked to attacker-provided machine code. As such, this paper is the first to study the security of PAC compilers for partial programs formally. We prove for a model of such a compiler that it is fully abstract. The proof uses a novel proof technique (dubbed TrICL, read trickle), which should be of broad interest because it reuses the whole-program compiler correctness relation for full abstraction, thus saving work. We also implement our scheme for C on CHERI, show that we can compile legacy C code with minimal changes, and show that the performance overhead of compiled code is roughly proportional to the number of cross-compilation-unit function calls.
Signed star k-domatic number of a graph
Creators: name: Sheikholeslami, Seyed Mahmoud
name: Volkmann, Lutz
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: Let $G$ be a simple graph without isolated vertices with vertex set

$V(G)$ and edge set $E(G)$ and let $k$ be a positive integer. A function  $f:E(G)\longrightarrow \{-1,

1\}$ is said to be a signed star $k$-dominating function on $G$ if

$\sum_{e\in E(v)}f(e)\ge k$ for every vertex $v$ of $G$, where

$E(v)=\{uv\in E(G)\mid u\in N(v)\}$. A set $\{f_1,f_2,\ldots,f_d\}$ of

signed star $k$-dominating functions on $G$ with the property that

$\sum_{i=1}^df_i(e)\le 1$ for each $e\in E(G)$, is called a signed

star  $k$-dominating family (of functions) on $G$. The maximum number of

functions in a signed star $k$-dominating family on $G$ is the signed

star $k$-domatic number of $G$, denoted by $d_{kSS}(G)$.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
EARTH RESISTANCE MEASUREMENTS A PANACEA TO IMPROPER GROUNDING SYSTEM: A CASE STUDY OF ILARO TOWNSHIP
Creators: name: Sunday S. Olowofela
name: Omolola, Samuel A.
name: Adelakun, Najeem Olawale
Publisher: name: figshare
Year: 2020
Subjects: subject: 90699 Electrical and Electronic Engineering not elsewhere classified
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 91503 Engineering Practice
subject: FOS: Other engineering and technologies

description: Installation of electrical works in a building requires a proper investigation about the building, the purpose which the structure will serve, the soil resistance, and the type of installation required by competent personnel. However, inadequate study leads to several domestic accidents such as fire outbreak, burns, and electrical shock etc. Effective grounding of the electrical system set up a common reference potential for any kind of power supply system as a low resistance connection to earth is required. This investigation of the Electrical performance of the earth in Ilaro provides a valuable insight into how the standard earth resistance value can be achieved and maintained over the life of the installation with minimum cost and effort. For this research work, six (6) different locations were considered, measurements were taken using a digital Earth Resistance Meter, Global Positioning System with other test equipment at these locations and the empirical data gotten was analyzed graphically for each location. The result shows that the resistance of four (4) areas under test was relatively high and the remaining two (2) areas were low with values obtained ranging from 2.9Ω -5.5Ω. This reveals that the resistance of the soil of Ilaro town is relatively high and not suitable for effective grounding without improving the conductivity of the soil.
A bijection between noncrossing and nonnesting partitions of types A, B and C
Creators: name: Mamede, Ricardo
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: The total number of noncrossing partitions of type $\Psi$ is the $n$th Catalan number

$\frac{1}{n+1}\binom{2n}{n}$ when $\Psi=A_{n-1}$,

and the coefficient binomial $\binom{2n}{n}$ when $\Psi=B_n$ or $C_n$, and these numbers coincide with the

correspondent number of nonnesting partitions. For type A, there are several

bijective proofs of this equality; in particular, the intuitive map, which locally

converts each crossing to a nesting, is one of them.

In this paper we present a bijection between nonnesting and noncrossing partitions of

types $A, B$ and $C$ that generalizes the type $A$ bijection that locally converts each crossing

to a nesting.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
A graph theoretic proof of the complexity of colouring by a local tournament with at least two directed cycles
Creators: name: MacGillivray, Gary
name: Swarts, Jacobus
name: Bang-Jensen, Jørgen
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: In this paper we give a graph theoretic proof of the fact that deciding whether a homomorphism exists to a fixed local tournament with at least two directed cycles is NP-complete. One of the main reasons for the graph theoretic proof is that it showcases all of the techniques that have been built up over the years in the study of the digraph homomorphism problem.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
Cards, permutations, and sums
Creators: name: Sands, Bill
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: We are given four cards, each containing four nonnegative real numbers, 

written one below the other, so that the sum of the numbers on each card is 1. 

We are allowed to put the cards in any order we like, then we write down 

the first number from the first card, the second number from the second card, 

the third number from the third card, and the fourth number from the fourth 

card, and we add these four numbers together. We wish to find real 

intervals $[a,b]$ with the following property: there is always an ordering of 

the four cards so that the above sum lies in $[a,b]$. We prove that the 

intervals $[1,2]$ and $[2/3,5/3]$ are solutions to this problem. It follows 

that 

$$[0,1],\ [1/3,4/3],\ [2/3,5/3],\ [1,2]$$ 

are the only minimal intervals which 

are solutions. We also discuss a generalization to $n$ cards, and give an 

equivalent formulation of our results in matrix terms.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
Structural Rigidity of Paranemic (PX) and Juxtapose (JX) DNA Nanostructures
Creators: name: Santosh, Mogurampelly
name: Maiti, Prabal K
Publisher: name: arXiv
Year: 2011
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Crossover motifs are integral components for designing DNA based nanostructures and nanomechanical devices due to their enhanced rigidity compared to the normal B-DNA. Although the structural rigidity of the double helix B-DNA has been investigated extensively using both experimental and theoretical tools, to date there is no quantitative information about structural rigidity and the mechanical strength of parallel crossover DNA motifs. We have used fully atomistic molecular dynamics simulations in explicit solvent to get the force-extension curve of parallel DNA nanostructures to characterize their mechanical rigidity. In the presence of mono-valent Na+ ions, we find that the stretch modulus (γ_1) of the paranemic crossover (PX) and its topo-isomer JX DNA structure is significantly higher (~ 30%) compared to normal B-DNA of the same sequence and length. However, this is in contrast to the original expectation that these motifs are almost twice rigid compared to the double-stranded B-DNA. When the DNA motif is surrounded by a solvent with Mg2+ counterions, we find an enhanced rigidity compared to Na+ environment due to the electrostatic screening effects arising from the divalent nature of Mg2+ ions. This is the first direct determination of the mechanical strength of these crossover motifs which can be useful for the design of suitable DNA for DNA based nanostructures and nanomechanical devices with improved structural rigidity.
description: 30 pages, 7 figures
Hydrogeochemical site characterization and groundwater flow modeling of the arsenic-contaminated Gotra aquifer, West Bengal, India
Creators: name: Koenig, Cassandra E.M.
Publisher: name: University of British Columbia
Year: 2011

description: Groundwater geochemistry and flow have been studied in Gotra, West Bengal, India, where geogenic arsenic contaminates groundwater at levels above World Health Organization limits. The village is situated upon the natural levee of an abandoned channel, which terminates a fluvio-deltaic depositional sequence. The formerly prograding meander bend deposited point-bar sands during the Holocene that now comprise the 30m-thick shallow aquifer, while incising deeper Pleistocene sands and a shallow floodplain sequence. Hand-pumped tubewells are completed in point-bar sands, whereas irrigation wells are generally screened within Pleistocene materials. Hydraulic conductivity of the point-bar aquifer is approximately 5x10⁻⁴ m/s. A leaky-confining layer of levee/crevasse splay deposits overlies this aquifer beneath crop fields. Near the village, the shallow aquifer is confined by channel-fill silts that have an estimated conductivity of 1x10⁻⁷ m/s. The paleohorizon separating Holocene and Pleistocene sediments is marked locally by fine-grained material comprised of organic material and a hard clay. Groundwater elevations vary 7m over the course of a given year due to monsoonal climate and groundwater extraction. Convergent flow towards shallow pumping wells is a salient feature during irrigation season, and persistent localized downward gradients suggest that meteoric recharge and pumping are the predominant groundwater sources and sinks. A northeast trending geochemical gradient in the point-bar aquifer suggests that local flows transporting arsenic are directed away from the channel-fill silt. Concentration gradients of terminal electron acceptors and redox reaction products in the shallow aqueous profile also coincide with a flowpath originating from this unit. A numerical model of groundwater flow was developed based on a conceptual model derived from field observations to investigate controls of arsenic transport and to provide a context in which to interpret geochemical data. Short- (7-day) and long- (3-year) term transient simulations were implemented to simulate groundwater flowpaths, water balance, and average residence times. Modeling results support field observations that contamination is related to the channel-fill unit deposit, and suggest that the water balance has been significantly altered compared to pre-irrigation conditions. Results also suggest contaminant flushing will not occur over a human timescale.
Strong d-collapsibility
Creators: name: Tancer, Martin
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: We introduce a notion of strong d-collapsibility. Using this notion, we

simplify the proof of Matoušek and the author showing that the nerve of a

family of sets of size at most d is d-collapsible.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
Measurement of the two-photon exchange contribution in elastic $ep$ scattering at VEPP-3
Creators: name: Gramolin, A. V.
name: Arrington, J.
name: Barkov, L. M.
name: Dmitriev, V. F.
name: Gauzshtein, V. V.
name: Golovin, R. A.
name: Holt, R. J.
name: Kaminsky, V. V.
name: Lazarenko, B. A.
name: Mishnev, S. I.
name: Muchnoi, N. Yu.
name: Neufeld, V. V.
name: Nikolenko, D. M.
name: Rachek, I. A.
name: Sadykov, R. Sh.
name: Shestakov, Yu. V.
name: Stibunov, V. N.
name: Toporkov, D. K.
name: de Vries, H.
name: Zevakov, S. A.
name: Zhilich, V. N.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We report on the status of the Novosibirsk experiment on a precision measurement of the ratio $R$ of the elastic $e^+ p$ and $e^- p$ scattering cross sections. Such measurements determine the two-photon exchange effect in elastic electron-proton scattering. The experiment is conducted at the VEPP-3 storage ring using a hydrogen internal gas target. The ratio $R$ is measured with a beam energy of 1.6 GeV (electron/positron scattering angles are $θ= 55 ÷75^{\circ}$ and $θ= 15 ÷25^{\circ}$) and 1 GeV ($θ= 65 ÷105^{\circ}$). We briefly describe the experimental method, paying special attention to the radiative corrections. Some preliminary results are presented.
description: 5 pages, 6 figures and 1 table; contribution to the Proceedings of the PHIPSI11 Workshop (Novosibirsk, Russia, 19-22 September 2011)
Isomorphism Testing Parameterized by Genus and Beyond
Creators: name: Neuen, Daniel
Publisher: name: CISPA
Year: 2023

description: We present an isomorphism test for graphs of Euler genus g running in time 2^{O(g^4 log g)}n^{O(1)}. Our algorithm provides the first explicit upper bound on the dependence on g for an fpt isomorphism test parameterized by the Euler genus of the input graphs. The only previous fpt algorithm runs in time f(g)n for some function f (Kawarabayashi 2015). Actually, our algorithm even works when the input graphs only exclude K_{3,h} as a minor. For such graphs, no fpt isomorphism test was known before. The algorithm builds on an elegant combination of simple group-theoretic, combinatorial, and graph-theoretic approaches. In particular, we introduce (t,k)-WL-bounded graphs which provide a powerful tool to combine group-theoretic techniques with the standard Weisfeiler-Leman algorithm. This concept may be of independent interest.
Computation of atomic fibers of Z-linear maps
Creators: name: Eisenschmidt, Elke
name: Hemmecke, Raymond
name: Köppe, Matthias
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: For given matrix $A\in\Z^{d\times n}$, the set

$P_{b}=\{z:Az=b,z\in\Z^n_+\}$ describes the preimage or fiber

of $b\in\Z^d$ under the $\Z$-linear map

$f_A:\Z^n_+\rightarrow\Z^d$, $x\mapsto Ax$. The fiber $P_{b}$

is called atomic, if $P_{b}=P_{b_1}+P_{b_2}$ implies

$b=b_1$ or $b=b_2$. In this paper we present a novel algorithm to

compute such atomic fibers. An algorithmic solution to appearing

subproblems, computational

examples and applications are included as well.
description: Contributions to Discrete Mathematics, Vol 6, No 2 (2011)
Ab initio quantum dynamics using coupled-cluster
Creators: name: Kvaal, Simen
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The curse of dimensionality (COD) limits the current state-of-the-art {\it ab initio} propagation methods for non-relativistic quantum mechanics to relatively few particles. For stationary structure calculations, the coupled-cluster (CC) method overcomes the COD in the sense that the method scales polynomially with the number of particles while still being size-consistent and extensive. We generalize the CC method to the time domain while allowing the single-particle functions to vary in an adaptive fashion as well, thereby creating a highly flexible, polynomially scaling approximation to the time-dependent Schrödinger equation. The method inherits size-consistency and extensivity from the CC method. The method is dubbed orbital-adaptive time-dependent coupled-cluster (OATDCC), and is a hierarchy of approximations to the now standard multi-configurational time-dependent Hartree method for fermions. A numerical experiment is also given.
description: 5 figures
Do winning tickets exist before DNN training?
Creators: name: Grosse, Kathrin
name: Backes, Michael
Publisher: name: CISPA
Year: 2023

description: The recent lottery ticket hypothesis proposes that there is at least one sub-network that matches the accuracy of the original network when trained in isolation. Recent work shows that under SGD noise, several such tickets emerge. We build on these works and study how winning tickets derived from one fixed network differ in structural and functional terms under varying levels of stochasticity. Structurally, we show that the Hamming distance of winning tickets' shapes follow the hyper-geometric distribution. Functionally, our experiments validate that different emerging winning tickets are not disguised variants of each other, but diverge also concerning their classification outputs. Last but not least, different regimes of stochasticity affect winning tickets. Decreasing randomness during training also decreases the tickets' functional and structural distance.
A4 Flavor Models in Split Seesaw Mechanism
Creators: name: Adulpravitchai, Adisorn
name: Takahashi, Ryo
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A seesaw mechanism in an extra-dimension, known as the split seesaw mechanism, provides a natural way to realize a splitting mass spectrum of right-handed neutrinos. It leads to one keV sterile neutrino as a dark matter candidate and two heavy right-handed neutrinos being responsible for leptogenesis to explain the observed baryon asymmetry of the Universe. We study models based on $A_4$ flavor symmetry in the context of the split seesaw mechanism. It is pointed out that most of known $A_4$ flavor models with three right-handed neutrinos being $A_4$ triplet suffer from a degeneracy problem for the bulk mass terms, which disturbs the split mechanism for right-handed neutrino mass spectrum. Then we construct a new $A_4$ flavor model to work in the split seesaw mechanism. In the model, the experimentally observed neutrino masses and mixing angles can be realized from both type I+II seesaw contributions. The model predicts the $μ-τ$ symmetry in the neutrino mass matrix at the leading order, resulting in the vanishing $θ_{13}$ and maximal $θ_{23}$. The flavor symmetry $A_4$ is broken via the flavon vacuum alignment which can be obtained from the orbifold compactification. The model can be consistent with all data of neutrino oscillation experiments, cosmological discussions of dark matter abundance, leptogenesis, and recent astrophysical data.
description: 21 pages, 1 figure, version to appear in JHEP
Variation in hydrothermal muscovite and chlorite composition in the Highland Valley porphyry Cu-Mo district, British Columbia, Canada
Creators: name: Alva Jimenez, Tatiana Romy
Publisher: name: University of British Columbia
Year: 2011

description: Muscovitic mica and chlorite are common alteration components in porphyry Cu-Mo deposits. Their mineral chemistry varies depending on the degree of fluid rock interaction, pressure and temperature and can therefore be used as alteration vector. At the Valley porphyry Cu-Mo deposit of the Highland Valley porphyry district, southern British Columbia, muscovitic mica forms part of the high-temperature K-silicate assemblage. It also forms in the adjacent Bethsaida Zone and the abandoned Alwin mine some 4 km to the west, where it is associated with quartz-sulfide veins. The host rock of these areas is granodiorite of the Bethsaida phase of the Guichon Creek batholith. In the Bethlehem deposits, fine- to medium-grained muscovitic mica and chlorite form parallel to fractures or disseminated in a more mafic host rock. The muscovitic mica forms as several textural varieties, including vein selvages where they replace the rock, replacement of igneous biotite and feldspar whereas chlorite replaces mostly biotite and amphibole. Muscovite in the core of the Valley deposit is sodium-bearing (ca. 0.6wt%Na2O, 0.8wt%MgO), but is more phengitic (ca. 0.2wt%Na2O, 1.29wt%MgO) at the Alwin mine and the Bethlehem deposits. Titanium, Li, Sn, V and Sr are present in higher concentrations in muscovites from the Valley deposit compared to those from other areas. In contrast Tl, Rb, Cs, B, Mn, Co and Zn concentrations are higher in muscovite from the Alwin mine, Bethsaida zone and Bethlehem than those from the Valley deposit. Major and trace element chemistry of muscovite reflects decreasing temperature and increasing pH from the central porphyry zones Valley to the peripheral hydrothermal systems. High concentrations of Cs, Rb and Tl in whole-rocks indicate extensive muscovite alteration, whereas high Li, Zn, Mn and Co relate to abundant hydrothermal chlorite in the whole rock. The variability in the chemistry of muscovite and chlorite is also detected using short-wave infrared spectra (SWIR). An absorption feature between 2200 nm to 2202 nm characterizes the Na-bearing muscovites from Valley, whereas more phengitic-muscovites from Alwin and Bethlehem deposits have an absorption feature between 2205 nm to 2209 nm. Mg-rich chlorites have an absorption feature at around 2341 nm, whereas the same feature shifts to 2350 nm for Fe-rich chlorites. Muscovite and chlorite chemistry varies laterally in porphyry Cu-Mo districts and is also reflected in SWIR spectra and whole rock geochemistry, techniques widely used in exploration.
Chemical constituents from the leaves of Melia azedarach
Creators: name: Zeng, Jin
name: Ma, Rui-Jing
name: Wang, Ling
name: Zhang, Sheng-Nan
name: Song, Hong-Zhi
name: Yang, Yang
name: Tan, Qin-Gang
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biophysics
subject: Biochemistry
subject: Physical Sciences not elsewhere classified
subject: Genetics
subject: FOS: Biological sciences
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified

description: Six compounds, benzyl 3-O-β-D-glucopyranosyl-7-hydroxybenzoate (1), spathulenol (2), 1,7,8-trihydroxy-2-naphtaldehyde (3), quercetin (4), astragalin (5) and 2-methoxy-4-(2-propenyl)phenyl β-D-glucoside (6), were isolated from the leaves of Melia azedarach L. The structure elucidation of compound 1 was discussed in detail based on its 2D-NMR data. Compound 1 showed weak cytotoxicity against the cell lines of T-24, NCI-H460, HepG2, SMMC-7721, CNE, MDA-MB-231 and B16F10 with the inhibition rates from 10.01% to 34.05% at the concentration of 80 μM.
The life trajectory of elderly institutionalized holocaust survivors: an ethnographic study
Creators: name: Pirner, Diane Marion
Publisher: name: University of Calgary
Year: 2006

description: Bibliography: p. 210-226
description: During the last decade several research projects have provided increasing evidence to support the assumption that historical events such as wars can and do have both a profound and a sustained impact on the ways in which individuals respond to, and cope with the numerous and often cumulative challenges that arise during the final decades of life. Debate continues among gerontologists not only about the effects of trauma at a young age on the well-being of these individuals once they are older (i.e. 65 and over), but also how such outcomes may vary between various cultural groups. The purpose of this descriptive study was to gain insights into one aspect of this debate by conducting a series of participant observation sessions and a series of in depth interviews with eight Holocaust survivors who were now living in retirement home. The three objectives of the study were to gain: 1) insights into the pattern of events experienced by Holocaust survivors within defined epochs of their life; 2) insights into the pattern of cultural beliefs, values, attitudes and meanings that are attributed to the above mentioned events by Holocaust survivors who are living in a retirement home. This knowledge should afford a greater understanding of the often quoted concept of "survivorship" as well as the coping patterns of the survivors; and 3) knowledge about strategies that will assist in the development of more culturally sensitive nursing care for this (Holocaust survivor) elderly population. A number of unique findings (themes) were discovered in the stories provided by the eight participants in this ethnographic study of the life trajectory of Holocaust survivors. One central finding was that most of the participants experienced similar life events for these three epochs. Furthermore, although these survivors were from diverse countries (e.g., Poland, Romania, and Hungary) , there was considerable similarity in their cultural perspectives: that is, in their beliefs, values, and attitudes about the various happenings, as indicated by the meanings that they attributed to the events that contributed to their survivorship and their ability to cope throughout their life, particularly the impact on their coping style during the current retirement home phase of their life trajectory. Throughout all of their accounts there were indicators that researchers variously refer to as hardiness or resilience. That is, they articulated a personal philosophy that was characterized by hope, trust, and facilitative beliefs. Furthermore, they emphasized the need for engagement in meaningful activities and the importance of family and social support system such as friendships.
``Go eat a bat, Chang!'': On the Emergence of Sinophobic Behavior on Web Communities in the Face of COVID-19
Creators: name: Tahmasbi, Fatemeh
name: Schild, Leonard
name: Ling, Chen
name: Blackburn, Jeremy
name: Stringhini, Gianluca
name: Zhang, Yang
name: Zannettou, Savvas
Publisher: name: CISPA
Year: 2023

description: The outbreak of the COVID-19 pandemic has changed our lives in unprecedented ways. In the face of the projected catastrophic consequences, many countries have enacted social distancing measures in an attempt to limit the spread of the virus. Under these conditions, the Web has become an indispensable medium for information acquisition, communication, and entertainment. At the same time, unfortunately, the Web is being exploited for the dissemination of potentially harmful and disturbing content, such as the spread of conspiracy theories and hateful speech towards specific ethnic groups, in particular towards Chinese people since COVID-19 is believed to have originated from China. In this paper, we make a first attempt to study the emergence of Sinophobic behavior on the Web during the outbreak of the COVID-19 pandemic. We collect two large-scale datasets from Twitter and 4chan's Politically Incorrect board (/pol/) over a time period of approximately five months and analyze them to investigate whether there is a rise or important differences with regard to the dissemination of Sinophobic content. We find that COVID-19 indeed drives the rise of Sinophobia on the Web and that the dissemination of Sinophobic content is a cross-platform phenomenon: it exists on fringe Web communities like \dspol, and to a lesser extent on mainstream ones like Twitter. Also, using word embeddings over time, we characterize the evolution and emergence of new Sinophobic slurs on both Twitter and /pol/. Finally, we find interesting differences in the context in which words related to Chinese people are used on the Web before and after the COVID-19 outbreak: on Twitter we observe a shift towards blaming China for the situation, while on /pol/ we find a shift towards using more (and new) Sinophobic slurs.
Prediction of Cosmological Constant $Λ$ In Veneziano Ghost Theory of QCD$^{*}$
Creators: name: Li-juan, Zhou
name: Wei-xing, Ma
name: Kisslinger, Leonard S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Based on the Veneziano ghost theory of QCD, we estimate the cosmological constant $Λ$, which is related to the vacuum energy density, $ρ_Λ$, by $Λ= 8πG ρ_Λ$. In the recent Veneziano ghost theory $ρ_Λ$ is given by the absolute value of the product of the local quark condensate and quark current mass:$ρ_Λ = \frac{2N_{f}H}{m_{η'}}c |m_{q}<0|:\bar{q}q:|0>|$. By solving Dyson-Schwinger Equations for a dressed quark propagator, we found the local quark condensate $<0|:\bar{q}q:|0> \simeq -(235 MeV)^{3}$, the generally accepted value. The quark current mass is $m_{q} \simeq$ 4.0 Mev. This gives the same result for $ρ_Λ$ as found by previous authors, which is somewhat larger than the observed value. However, when we make use of the nonlocal quark condensate, $<0|:\bar{q}(x)q(0):|0>= g(x)<0|:\bar{q}q:|0>$, with g(x) estimated from our previous work, we find $Λ$ is in a good agreement with the observations.
description: 12 pages, no figures. arXiv admin note: text overlap with arXiv:nucl-th/0404015, arXiv:1010.1339, arXiv:0906.2162
Strictly chained (p,q)-ary partitions
Creators: name: Imbert, Laurent
name: Philippe, Fabrice
Publisher: name: Faculty of Science, University of Calgary
Year: 2010

description: We consider a special type of integer partitions in which the parts of the form $p^aq^b$, for some relatively prime integers $p$ and $q$, are restricted by divisibility conditions. We investigate the problems of generating and encoding those partitions and give some estimates for several partition functions.
description: Contributions to Discrete Mathematics, Vol 5, No 2 (2010)
Resonant dynamics for the quintic non linear Schrödinger equation
Creators: name: Grebert, Benoît
name: Thomann, Laurent
Publisher: name: arXiv
Year: 2011
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We consider the quintic nonlinear Schrödinger equation (NLS) on the circle. We prove that there exist solutions corresponding to an initial datum built on four Fourier modes which form a resonant set, which have a non trivial dynamic that involves periodic energy exchanges between the modes initially excited. It is noticeable that this nonlinear phenomena does not depend on the choice of the resonant set. The dynamical result is obtained by calculating a resonant normal form up to order 10 of the Hamiltonian of the quintic NLS and then by isolating an effective term of order 6. Notice that this phenomena can not occur in the cubic NLS case for which the amplitudes of the Fourier modes are almost actions, i.e. they are almost constant.
description: 32 pages, 4 figures
Option-closed games
Creators: name: Nowakowski, Richard J.
name: Ottaway, Paul
Publisher: name: Faculty of Science, University of Calgary
Year: 2011

description: We consider the class of combinatorial games with the property that

each player's move eliminates some options but does not add any new

options for that player. While the canonical form can be

complicated, we show that the reduced canonical form of a position

is either a number or a switch. Moreover, for a given position, the

difference between the two canonical forms is bounded by

$\cgdoubledown\cgstar$ and $\cgdoubleup\cgstar$.
description: Contributions to Discrete Mathematics, Vol 6, No 1 (2011)
Microwave-induced resistance oscillations and zero-resistance states in 2D electron systems with two occupied subbands
Creators: name: Inarrea, Jesus
name: Platero, Gloria
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on theoretical studies of recently discovered microwave-induced resistance oscillations and zero resistance states in Hall bars with two occupied subbands. In the same results, resistance presents a peculiar shape which appears to have a built-in interference effect not observed before. We apply the microwave-driven electron orbit model, which implies a radiation-driven oscillation of the two-dimensional electron system. Thus, we calculate different intra and inter-subband electron scattering rates and times that are revealing as different microwave-driven oscillations frequencies for the two electronic subbands. Through scattering, these subband-dependent oscillation motions interfere giving rise to a striking resistance profile. We also study the dependence of irradiated magnetoresistance with power and temperature. Calculated results are in good agreement with experiments.
description: 7 pages, 6 figures
Deconstructing blazars: A different scheme for jet kinematics in flat-spectrum AGN
Creators: name: Karouzos, Marios
name: Britzen, Silke
name: Witzel, Arno
name: Zensus, Anton J.
name: Eckart, Andreas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Recent VLBI studies of the morphology and kinematics of individual BL Lac objects (S5 1803+784, PKS 0735+178, etc.) have revealed a new paradigm for the pc-scale jet kinematics of these sources. Unlike the apparent superluminal outward motions usually observed in blazars, most, if not all, jet components in these sources appear to be stationary with respect to the core, while exhibiting strong changes in their position angles. As a result, the jet ridge lines of these sources evolve substantially, at times forming a wide channel-flow. We investigate the Caltech-Jodrell Bank flat-spectrum (CJF) sample of radio-loud active galaxies to study this new kinematic scenario for flat-spectrum AGN. We develop a number of tools that extract information about the apparent linear and angular evolution of the CJF jet ridge lines, as well as their morphology. In this way, we study both radial and non-radial apparent motions in the CJF jets. We find that approximately half of the sample shows appreciable apparent jet widths ($>10 degrees$), with BL Lac jet ridge lines showing significantly larger apparent widths than both quasars and radio galaxies. In addition, BL Lac jet ridge lines are found to change their apparent width more strongly. Finally, BL Lac jet ridge lines show the least apparent linear evolution, which translates to the smallest apparent expansion speeds for their components. We find compelling evidence supporting a substantially different kinematic scenario for flat-spectrum radio-AGN jets and in particular for BL Lac objects. In addition, we find that variability is closely related to the properties of a source's jet ridge line. Variable quasars are found to show "BL Lac like" behavior, compared to their non-variable counterparts.
description: 16 pages, 13 figures, accepted for publication in Astronomy & Astrophysics