cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Working between cultures : individual voices and multiple visions of childcare teachers
Creators: name: Waqar, Zoobi
Publisher: name: University of British Columbia
Year: 2009

description: The thesis focuses on the tensions, issues and challenges childcare teachers experience in a culturally diverse children center. It explores childcare teachers' understandings and practices using the mainstream early childhood education curriculum approach in North America. Teachers' knowledge of early childhood education is important to my discussion because it reflects on the cultural perspectives, values and personal philosophies they bring to the classroom. Skills that teachers want children to know and learn are related to their personal beliefs and experience of not only what children are able to do at a particular level, but what they feel is important for children to learn. Over a period of six months, I was participant-observer in one childcare center. Information gathering included open-ended interviews, fieldnotes, and conversations. My learning inquiry involves moving and descriptive journeys from one to the next, and within the journeys are stories presented through portraiture, my poems and different textual illustrations. In this context childcare teachers' voices are heard, illustrating that there are many tensions, issues and challenges that they confront when working with children from diverse cultures. In the long and continuous journey that I undertake, my personal life experiences weave a pattern with childcare teachers' experiences about their concerns of using the early childhood curriculum approaches for children from a variety of cultures. This inquiry process begins as ethnography of voices that becomes a proactive process. I document childcare teachers' lives and their words, a deliberate gesture to bring forward whom I have come to know in a community. By incorporating teachers' biographies into my thesis, and listening to what they have to say, considering why and how they say it, I add depth to the journey they have taken as individuals. And in sharing some of their tense moments with me, they express their concerns, and boldly depict the issues in childcare and the challenges they have taken charge of, and thankfully, find release.
The partition function of interfaces from the Nambu-Goto effective string theory
Creators: name: Billo, M.
name: Caselle, M.
name: Ferro, L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We consider the Nambu-Goto bosonic string model as a description of the physics of interfaces. By using the standard covariant quantization of the bosonic string, we derive an exact expression for the partition function in dependence of the geometry of the interface. Our expression, obtained by operatorial methods, resums the loop expansion of the NG model in the "physical gauge" computed perturbatively by functional integral methods in the literature. Recently, very accurate Monte Carlo data for the interface free energy in the 3d Ising model became avaliable. Our proposed expression compares very well to the data for values of the area sufficiently large in terms of the inverse string tension. This pattern is expected on theoretical grounds and agrees with previous analyses of other observables in the Ising model.
description: 28 pages, 4 figures
The singularities of the rate function of quantum coherent work in one-dimensional transverse field Ising model
Creators: name: Xu, Bao-Ming
name: Wang, Chao-Quan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Quantum coherence will undoubtedly play a fundamental role in understanding of the dynamics of quantum many-body systems, thereby to reveal its genuine contribution is of great importance. In this paper, we specialize our discussions to the one-dimensional transverse field quantum Ising model initialized in the coherent Gibbs state. After quenching the strength of the transverse field, the effects of quantum coherence are studied by the rate function of quantum work distribution. We find that quantum coherence not only recovers the quantum phase transition destroyed by thermal fluctuations, but also generates some entirely new singularities both in the static state and dynamics. It can be manifested that these singularities are rooted in spin flips causing the sudden change of the domain boundaries of spin polarization. This work sheds new light on the fundamental connection between quantum critical phenomena and quantum coherence.
description: 8 pages, 4 figures, welcome the comments. arXiv admin note: text overlap with arXiv:1810.04614, arXiv:cond-mat/0701768 by other authors
NONPRICE RATIONING OF AGRICULTURAL CREDIT BY TWO TRADING BANKS
Creators: name: Ockwell, Anthony P.
name: Batterham, Robert L.
name: Ockwell, Anthony P.
name: Batterham, Robert L.
Publisher: name: Unknown
Year: 1980
Subjects: Agricultural Finance

description: The non price mechanism used by the trading banks to ration credit among farmers was studied using a survey designed along the lines of a factorial experiment. Of the farmer characteristics studied, managerial ability emerged as being most important in affecting the amount a farmer could borrow. Banking history and, to a lesser extent, security were also influential. However, the research indicated that there is great variability in the amounts that individual bank managers are prepared to lend.
Hybrid Modular Redundancy: Exploring Modular Redundancy Approaches in RISC-V Multi-Core Computing Clusters for Reliable Processing in Space
Creators: name: Rogenmoser, Michael
name: Tortorella, Yvan
name: Rossi, Davide
name: Conti, Francesco
name: Benini, Luca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: Hardware Architecture (cs.AR)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Space Cyber-Physical Systems (S-CPS) such as spacecraft and satellites strongly rely on the reliability of onboard computers to guarantee the success of their missions. Relying solely on radiation-hardened technologies is extremely expensive, and developing inflexible architectural and microarchitectural modifications to introduce modular redundancy within a system leads to significant area increase and performance degradation. To mitigate the overheads of traditional radiation hardening and modular redundancy approaches, we present a novel Hybrid Modular Redundancy (HMR) approach, a redundancy scheme that features a cluster of RISC-V processors with a flexible on-demand dual-core and triple-core lockstep grouping of computing cores with runtime split-lock capabilities. Further, we propose two recovery approaches, software-based and hardware-based, trading off performance and area overhead. Running at 430 MHz, our fault-tolerant cluster achieves up to 1160 MOPS on a matrix multiplication benchmark when configured in non-redundant mode and 617 and 414 MOPS in dual and triple mode, respectively. A software-based recovery in triple mode requires 363 clock cycles and occupies 0.612 mm2, representing a 1.3% area overhead over a non-redundant 12-core RISC-V cluster. As a high-performance alternative, a new hardware-based method provides rapid fault recovery in just 24 clock cycles and occupies 0.660 mm2, namely ~9.4% area overhead over the baseline non-redundant RISC-V cluster. The cluster is also enhanced with split-lock capabilities to enter one of the redundant modes with minimum performance loss, allowing execution of a mission-critical or a performance section, with <400 clock cycles overhead for entry and exit. The proposed system is the first to integrate these functionalities on an open-source RISC-V-based compute device, enabling finely tunable reliability vs. performance trade-offs.
AUSTRALIAN AGRICULTURE AND WORLD COMMODITY TRADING ARRANGEMENTS
Creators: name: Harris, Stuart
name: Harris, Stuart
Publisher: name: Unknown
Year: 1980
Subjects: International Relations/Trade

description: A long period of international discussion and negotiation about new global trading arrangements ended in 1979. Despite changed economic and institutional circumstances, and growing deficiencies in the. existing arrangements for agricultural trade, these negotiations have done little to improve the efficiency with which the world's agricultural resources are used. Rather, they have tended to institutionalise the status quo. This is likely further to disadvantage efficient producers and to lead to a growing bilateralism in trading relationships, with consequent increased politicisation and potential for conflicts and instability.
Noncommutative Unification of General Relativity and Quantum Mechanics
Creators: name: Heller, Michael
name: Pysiak, Leszek
name: Sasin, Wieslaw
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In Gen. Rel. Grav. (36, 111-126 (2004); in press, gr-qc/0410010) we have proposed a model unifying general relativity and quantum mechanics based on a noncommutative geometry. This geometry was developed in terms of a noncommutative algebra A defined on a transformation groupoid given by the action of a group G on a space E. Owing to the fact that G was assumed to be finite it was possible to compute the model in full details. In the present paper we develop the model in the case when G is a noncompact group. It turns out that also in this case the model works well. The case is important since to obtain physical effects predicted by the model we should assume that G is a Lorentz group or some of its representations. We show that the generalized Einstein equation of the model has the form of the eigenvalue equation for the generalized Ricci operator, and all relevant operators in the quantum sector of the model are random operators; we study their dynamics. We also show that the model correctly reproduces general relativity and the usual quantum mechanics. It is interesting that the latter is recovered by performing the measurement of any observable. In the act of such a measurement the model ``collapses'' to the usual quantum mechanics.
description: 23 LaTex pages
Homeland Security and the Rules of International Trade
Creators: name: Kerr, William A.
name: Kerr, William A.
Publisher: name: Unknown
Year: 2004
Subjects: subject: International Relations/Trade
subject: agents
subject: capture
subject: cost
subject: essential security interests
subject: homeland security
subject: national security
subject: protectionism
subject: terrorism

description: International trade law is very clear: national security concerns take precedent over any commitments in trade agreements. In response to the terrorist attacks in New York and Washington on September 11, 2001, the United States and other countries have been putting in place new anti-terrorist measures, many of which will act to inhibit international trade. As with any measure that inhibits international trade, these new measures will provide an economic benefit to domestic vested interests in importing countries. Guarding against the possibility of terrorist acts is by nature a speculative activity, and it is difficult to refute the need for the anti-terrorist measures put in place by governments. As a result, trading partners may be frustrated by what they perceive as protectionist measures and tempted to reply with trade-restricting measures of their own, imposed under the guise of national security. Thus, governments have a vested interest in being willing to listen to the comments of their trading partners and ensuring that the policies put in place achieve their goal in the least-trade-distorting manner - even if they are not obliged to do so. It is particularly important that the measures put in place have either sunset clauses or automatic reviews pertaining to their efficacy in achieving anti-terrorist goals. These provisions will help ensure that anti-terrorist measures are not captured by those who benefit from the economic protection they provide.
Second-order integrable Lagrangians and WDVV equations
Creators: name: Ferapontov, Evgeny V.
name: Pavlov, Maxim V.
name: Xue, Lingling
Publisher: name: arXiv
Year: 2020
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 35Q51, 37K05, 37K10, 37K20, 53D45

description: We investigate integrability of Euler-Lagrange equations associated with 2D second-order Lagrangians of the form \begin{equation*} \int f(u_{xx},u_{xy},u_{yy})\ dxdy. \end{equation*} By deriving integrability conditions for the Lagrangian density $f$, examples of integrable Lagrangians expressible via elementary functions, Jacobi theta functions and dilogarithms are constructed. A link of second-order integrable Lagrangians to WDVV equations is established. Generalisations to 3D second-order integrable Lagrangians are also discussed.
Anoxypristis undetermined
Creators: name: Cicimurri, David J.
name: Ebersole, Jun A.
name: Stringer, Gary L.
name: Starnes, James E.
name: Phillips, George E.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Rhinopristiformes
Pristidae
Anoxypristis
Anoxypristis undetermined

description: Anoxypristis sp.
Fig. 13S–X
Material examined
UNITED STATES OF AMERICA – Mississippi • 10 rostral spines; Catahoula Formation; MMNS VP-12071 (Fig. 13S–U), MMNS VP-12072 (7 specimens), MMNS VP-12072.1 (Fig. 13V–X), SC 2013.28.514.
Description
The spines are elongated, very thin dorso-ventrally (Fig. 13T, W), with a triangular dorsal outline. The anterior and posterior faces are thin and converge distally to form a medially located point (Fig. 13U, X). The basal surface may have an elliptical or teardrop-shaped (rounded anterior margin but tapering posteriorly) outline (Fig. 13S, V).
Remarks
These spines are comparable to those occurring on a rostrum of extant Anoxypristis sp. that we examined (SC 86.214.1). They differ from the spines of the Catahoula Formation Pristis sp. (see above) and those of extant Pristis (i.e., MSC 43849, MSC 43850, SC 90.80.1) by being much thinner dorso-ventrally (although Pristis spines are very thin at the pointed distal end), having rather thin anterior and posterior faces, and having an elliptical to teardrop-shaped basal outline. In contrast, the fossil Pristis sp. spines are comparably thicker, very elongated but narrow antero-posteriorly, the posterior surface is concave, and the basal outline is “D” shaped. Although Cicimurri & Knight (2009) observed an Anoxypristis sp. rostral spine from the Chandler Bridge Formation (Chattian, NP25) of South Carolina that was housed in a private collection, sawfish specimens have yet to be formally described from the South Carolina Oligocene. Anoxypristis spines of similar morphology to those from the Catahoula Formation have been confirmed from middle Eocene deposits in Alabama (Cappetta & Case 2016; Ebersole et al. 2019), but we cannot determine whether they are conspecific.
description: Published as part of Cicimurri, David J., Ebersole, Jun A., Stringer, Gary L., Starnes, James E. & Phillips, George E., 2025, Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA, pp. 1-131 in European Journal of Taxonomy 984 (1) on pages 53-54, DOI: 10.5852/ejt.2025.984.2851, http://zenodo.org/record/15126034
Improving PSNR-based Quality Metrics Performance For Point Cloud Geometry
Creators: name: Javaheri, Alireza
name: Brites, Catarina
name: Pereira, Fernando
name: Ascenso, João
Publisher: name: arXiv
Year: 2020
Subjects: subject: Image and Video Processing (eess.IV)
subject: Multimedia (cs.MM)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: An increased interest in immersive applications has drawn attention to emerging 3D imaging representation formats, notably light fields and point clouds (PCs). Nowadays, PCs are one of the most popular 3D media formats, due to recent developments in PC acquisition, namely with new depth sensors and signal processing algorithms. To obtain high fidelity 3D representations of visual scenes a huge amount of PC data is typically acquired, which demands efficient compression solutions. As in 2D media formats, the final perceived PC quality plays an important role in the overall user experience and, thus, objective metrics capable to measure the PC quality in a reliable way are essential. In this context, this paper proposes and evaluates a set of objective quality metrics for the geometry component of PC data, which plays a very important role in the final perceived quality. Based on the popular PSNR PC geometry quality metric, the novel improved PSNR-based metrics are proposed by exploiting the intrinsic PC characteristics and the rendering process that must occur before visualization. The experimental results show the superiority of the best-proposed metrics over the state-of-the-art, obtaining an improvement of up to 32% in the Pearson correlation coefficient.
description: This article is accepted in 27th International Conference on Image Processing (ICIP 2020)
Morphology of synchrotron emission in young supernova remnants
Creators: name: Cassam-Chenai, Gamil
name: Decourchelle, Anne
name: Ballet, Jean
name: Ellison, Donald C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In the framework of test-particle and cosmic-ray modified hydrodynamics, we calculate synchrotron emission radial profiles in young ejecta-dominated supernova remnants (SNRs) evolving in an ambient medium which is uniform in density and magnetic field. We find that, even without any magnetic field amplification by Raleigh-Taylor instabilities, the radio synchrotron emission peaks at the contact discontinuity because the magnetic field is compressed and is larger there than at the forward shock. The X-ray synchrotron emission sharply drops behind the forward shock as the highest energy electrons suffer severe radiative losses.
description: 8 pages, 6 figures, Accepted for publication in A&A
Cannon-Thurston Maps,i-bounded Geometry and a theorem of McMullen
Creators: name: Mj, Mahan
Publisher: name: arXiv
Year: 2005
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M50

description: The notion of i-bounded geometry generalises simultaneously bounded geometry and the geometry of punctured torus Kleinian groups. We show that the limit set of a surface Kleinian group of i-bounded geometry is locally connected by constructing a natural Cannon-Thurston map. This is an exposition of a special case of the main result of arXiv:math/0607509.
description: v3: 32 pages 3 figures
Quantum coherent control of nonlinear thermoelectric transport in a triple-dot Aharonov-Bohm heat engine
Creators: name: Behera, Jayasmita
name: Bedkihal, Salil
name: Agarwalla, Bijay Kumar
name: Bandyopadhyay, Malay
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate the role of quantum coherence and higher harmonics resulting from multiple-path interference in nonlinear thermoelectricity in a two-terminal triangular triple-dot Aharonov-Bohm (AB) interferometer. We quantify the trade-off between efficiency and power in the nonlinear regime of our simple setup comprising three non-interacting quantum dots (two connected to two biased metallic reservoirs) placed at the vertex of an equilateral triangle, and a magnetic flux $Φ$ pierces it perpendicularly. For a spatially symmetric setup, we achieve optimal efficiency and power output when the inter-dot tunneling strength is comparable to the dot-lead coupling, AB phase $ϕ=π/2$. Our analysis reveals that the presence of higher harmonics is necessary but not sufficient to achieve optimal power output. The maximal constructive interference represented by three close-packed resonance peaks of the unit transmission can enhance the power output ($P_{max}\sim 2.35\,\mathrm{fW}$) almost 3.5 times as compared to the case where only a single channel participates in the transport, and the corresponding efficiency is about $0.80η_{c}$ where $η_{c}$ is the Carnot efficiency. Geometric asymmetries and their effects on efficiency and power output are also investigated. An asymmetric setup characterized by the ratio of the coupling to the source and the drain terminals ($x$) can further enhance the maximum power output $P_{max}\sim 3.85\,\mathrm{fW}$ for $x=1.5$ with the same efficiency as that of the symmetric case. Our investigation reveals that the output power and efficiency are optimal in the wide-band limit. The power output is significantly reduced for the narrow-band case. On the other hand, disorder effects radically reduce the performance of the heat engine.
Taming the Dragon: The WTO After the Accession of China
Creators: name: Kerr, William A.
name: Hobbs, Anna L.
name: Kerr, William A.
name: Hobbs, Anna L.
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: accession
subject: China
subject: decision making
subject: unequal treaties
subject: WTO

description: The accession of China to the WTO may take place in the near future. While much attention has been given to the effect this will have on international trade and the Chinese economy, less attention has been given to the effect on the WTO. China is a large, developing, transition economy that is likely to alter the WTO in a number of ways. The paper examines three aspects of China's accession and their implications for the WTO: (1) will China play by the rules?; (2) market socialism in the WTO's market-based system; and (3) the organisation's decision-making process.
Geomagnetic storm dependence on the solar flare class
Creators: name: Yermolaev, Yu. I.
name: Yermolaev, M. Yu.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Space Physics (physics.space-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Content. Solar flares are often used as precursors of geomagnetic storms. In particular, Howard and Tappin (2005) recently published in A&A a dependence between X-ray class of solar flares and Ap and Dst indexes of geomagnetic storms which contradicts to early published results. Aims. We compare published results on flare-storm dependences and discuss possible sources of the discrepancy. Methods. We analyze following sources of difference: (1) different intervals of observations, (2) different statistics and (3) different methods of event identification and comparison. Results. Our analysis shows that magnitude of geomagnetic storms is likely to be independent on X-ray class of solar flares.
description: 3 pages, 1 table
Superradiance in dispersive black hole analogues
Creators: name: Patrick, Sam
name: Weinfurtner, Silke
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Wave equations containing spatial derivatives which are higher than second order arise naturally in the context of condensed matter systems. The solutions of such equations contain more than two modes and consequently, the range of possible interactions between the different modes is significantly enhanced compared to the two mode case. We develop a framework for analysing the different mode interactions based on the classical turning points of the dispersion relation. We then apply this framework to the scattering of deep water gravity waves with a draining bathtub vortex, a system which constitutes the analogue of a rotating black hole in the non-dispersive limit. In particular, we show that the different scattering outcomes are controlled by the light-ring frequencies, a concept routinely applied in black hole physics, and two new frequencies which are related to the strength of dispersion. We find that the frequency range in which the reflected wave is superradiantly amplified appears as a simple modification to the non-dispersive case. However, the condition to observe this amplification is complicated by the fact that a superradiant mode can be reflected back into the system by scattering with one of the additional modes. We provide estimates for the reflection coefficients in the full dispersive regime.
description: 22 pages, 11 figures
Quantum Timing and Synchronization Problems
Creators: name: de Falco, Diego
name: Tamascelli, Dario
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Feynman's model of a quantum computer provides an example of a continuous-time quantum walk. Its clocking mechanism is an excitation of a basically linear chain of spins with occasional controlled jumps which allow for motion on a planar graph. The spreading of the wave packet poses limitations on the probability of ever completing the $s$ elementary steps of a computation: an additional amount of storage space $δ$ is needed in order to achieve an assigned completion probability. In this note we study the END instruction, viewed as a measurement of the position of the clocking excitation: a $π$-pulse indefinitely freezes the contents of the input/output register, with a probability depending only on the ratio $δ/s$.
description: 8 pages, 4 figures
An Overview of the Issues and Positions of the Major Countries in the WTO Negotiations
Creators: name: Miner, William M.
name: Miner, William M.
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: agricultural negotiations
subject: peace clause
subject: non-trade concerns
subject: subsidies
subject: WTO

description: Negotiations on agriculture were successfully launched in the WTO early in 2000. In the initial phase, negotiating proposals have been submitted by member countries and are being discussed in special sessions of the WTO Committee on Agriculture. A stock-taking exercise will be held in March 2001 to establish the next steps in the process. Many developments will influence the shape and dynamics of the negotiations, particularly the possibility of a comprehensive trade round. The first part of this paper examines the policy setting for the negotiations. The ongoing integration of economies and accompanying agricultural policy reforms provide an environment for further trade liberalization. Expansion of regional trade agreements and EU enlargement negotiations add urgency to the multilateral negotiating process. Newer trade issues and nontrade concerns, often connected to the food business, focus attention on the agricultural talks but may also retard them. A further factor that will add urgency is the anticipated expiry of the Peace Clause in 2003. The paper reviews the main agricultural issues for negotiation and the initial negotiating positions. Substantial progress in improving access is essential for the negotiations to succeed. The issues of export subsidies, other forms of export competition, unfair pricing practices, and dumping are receiving much attention. There are pressures to reduce or eliminate all forms of trade-distorting domestic support. Many non-trade concerns are being introduced, and legitimate trade issues will need to be addressed. The developing countries are determined to extract a better deal for their agriculture. The paper concludes that the elements for progress in further agricultural trade liberalization are coming to the negotiating table but much uncertainty remains both within and outside agriculture.
Initiation of motility on a compliant substrate
Creators: name: Étienne, Jocelyn
name: Recho, Pierre
Publisher: name: arXiv
Year: 2023
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Cell Behavior (q-bio.CB)
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: 92C17, 74-10

description: The conditions under which biological cells switch from a static to a motile state are fundamental to the understanding of many healthy and pathological processes. In this paper, we show that even in the presence of a fully symmetric protrusive activity at the cell edges, such a spontaneous transition can result solely from the mechanical interaction of the cell traction forces with an elastic substrate. The loss of symmetry of the traction forces leading to the cell propulsion is rooted in the fact that the surface loading follows the substrate deformation. The bifurcation between the static and motile states is characterized analytically and, considering the measurements performed on two cell types, we show that such an instability can realistically occur on soft in vivo substrates.
Using Stable Matching to Optimize the Balance between Accuracy and Diversity in Recommendation
Creators: name: Eskandanian, Farzad
name: Mobasher, Bamshad
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Increasing aggregate diversity (or catalog coverage) is an important system-level objective in many recommendation domains where it may be desirable to mitigate the popularity bias and to improve the coverage of long-tail items in recommendations given to users. This is especially important in multistakeholder recommendation scenarios where it may be important to optimize utilities not just for the end user, but also for other stakeholders such as item sellers or producers who desire a fair representation of their items across recommendation lists produced by the system. Unfortunately, attempts to increase aggregate diversity often result in lower recommendation accuracy for end users. Thus, addressing this problem requires an approach that can effectively manage the trade-offs between accuracy and aggregate diversity. In this work, we propose a two-sided post-processing approach in which both user and item utilities are considered. Our goal is to maximize aggregate diversity while minimizing loss in recommendation accuracy. Our solution is a generalization of the Deferred Acceptance algorithm which was proposed as an efficient algorithm to solve the well-known stable matching problem. We prove that our algorithm results in a unique user-optimal stable match between items and users. Using three recommendation datasets, we empirically demonstrate the effectiveness of our approach in comparison to several baselines. In particular, our results show that the proposed solution is quite effective in increasing aggregate diversity and item-side utility while optimizing recommendation accuracy for end users.
Trade Liberalization in the Dairy Sector: An Overview
Creators: name: Meilke, Karl D.
name: Lariviere, Sylvain
name: Martin, Craig
name: Meilke, Karl D.
name: Lariviere, Sylvain
name: Martin, Craig
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: dairy
subject: dispute
subject: export competition
subject: price discrimination
subject: processors
subject: tariffication

description: The world dairy industry is one of the most heavily protected in the agri-food sector. Exports of dairy products are dominated by the EU, the United States, New Zealand, and Australia. The major importers of dairy products are far less concentrated but include the EU, Japan, Mexico, Russia, the United States, and many others. The Canadian dairy industry came out of the Uruguay Round of trade negotiations with the continued ability to practise supply management, thereby allowing it to: (1) maintain prices above world market levels and (2) control the allocation of output to the domestic market. In fact, the Agreement on Agriculture opened the door for Canada to become a more aggressive exporter of dairy products by practising price discrimination between domestic and export markets. The Canadian dairy export program introduced in 1995 was challenged by the United States and New Zealand, and the WTO appellate body ruled against Canada because of the involvement of government agencies in the export process. Recent changes in Canada's dairy export program remove the direct involvement of government agencies but Canada may face a new WTO challenge, one that would force the WTO to rule if price discrimination, at least in some situations, is an export subsidy. Progress towards future trade liberalization in the dairy sector will involve reductions in export subsidies and over-quota tariffs, and increases in minimum access commitments. Reductions in explicit export subsidies will have the most effect on the EU. The effects of tariff reductions and increases in minimum access on domestic product prices, production, and consumption are commodity and country specific. Careful analysis of any proposed changes in these instruments will be required to fully understand their effects, both in Canada and on world markets.
Passivity-based Decentralized Control for Collaborative Grasping of Under-Actuated Aerial Manipulators
Creators: name: Jeong, Jinyeong
name: Kim, Min Jun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This paper proposes a decentralized passive impedance control scheme for collaborative grasping using under-actuated aerial manipulators (AMs). The AM system is formulated, using a proper coordinate transformation, as an inertially decoupled dynamics with which a passivity-based control design is conducted. Since the interaction for grasping can be interpreted as a feedback interconnection of passive systems, an arbitrary number of AMs can be modularly combined, leading to a decentralized control scheme. Another interesting consequence of the passivity property is that the AMs automatically converge to a certain configuration to accomplish the grasping. Collaborative grasping using 10 AMs is presented in simulation.
description: IEEE International Conference on Robotics and Automation (ICRA) 2023
Observation of Localization Using a Noisy Quantum Computer
Creators: name: Kudo, Kazue
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Quantum dynamics in a strongly disordered quantum many-body system show localization properties. The initial state memory is maintained owing to slow relaxation when the system is in the localized regime. This work demonstrates how localization can be observed using a noisy quantum computer by evaluating the magnetization and twist overlap in a quantum spin chain after short-time evolution. The quantities obtained from quantum-circuit simulation and real-device computation show their apparent dependence on disorder strength, although real-device computation suffers from noise-induced errors significantly. Using the exact diagonalization of the Hamiltonian, we analyze how noise-induced errors affect those quantities. The analysis also suggests how the twist overlap can reflect the information on the eigenstates of the Hamiltonian.
description: 8 pages, 4 figures
Nuclear polarizability effects in $^3$He$^+$ hyperfine splitting
Creators: name: Patkóš, Vojtěch
name: Yerokhin, Vladimir A.
name: Pachucki, Krzysztof
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The nuclear polarizability effects in hyperfine splitting of light atomic systems are not well known. The only system for which they were previously calculated is the hydrogen atom, where these effects were shown to contribute about 5\% of the total nuclear correction. One generally expects the polarizability effects to become more pronounced for composite nuclei. In the present work we determine the nuclear polarizability correction to the hyperfine splitting in He$^+$ by comparing the effective Zemach radius deduced from the experimental hyperfine splitting with the Zemach radius obtained from the electron scattering. We obtain a surprising result that the nuclear polarizability of the helion yields just 3\% of the total nuclear correction, which is smaller than for the proton.
description: 5 pages, corrected misprint in Eq. (23)
Horizon Entropy in Modified Gravity
Creators: name: Wang, Peng
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present an observation about the proposal that four-dimensional modification of general relativity may explain the observed cosmic acceleration today. Assuming that the thermodynamical nature of gravity theory continues to hold in modified gravity theories, we derive the modified horizon entropy formula from the modified Friedmann equation. We argue that our results imply that there are conceptual problems in some models of four-dimensional modification of general relativity.
description: 8 pages. v2: references added
Quantum Dot Source-Drain Transport Response at Microwave Frequencies
Creators: name: Havir, Harald
name: Haldar, Subhomoy
name: Khan, Waqar
name: Lehmann, Sebastian
name: Dick, Kimberly A.
name: Thelander, Claes
name: Samuelsson, Peter
name: Maisi, Ville F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum dots are frequently used as charge sensitive devices in low temperature experiments to probe electric charge in mesoscopic conductors where the current running through the quantum dot is modulated by the nearby charge environment. Recent experiments have been operating these detectors using reflectometry measurements up to GHz frequencies rather than probing the low frequency current through the dot. In this work, we use an on-chip coplanar waveguide resonator to measure the source-drain transport response of two quantum dots at a frequency of 6 GHz, further increasing the bandwidth limit for charge detection. Similar to the low frequency domain, the response is here predominantly dissipative. For large tunnel coupling, the response is still governed by the low frequency conductance, in line with Landauer-Büttiker theory. For smaller couplings, our devices showcase two regimes where the high frequency response deviates from the low frequency limit and Landauer-Büttiker theory: When the photon energy exceeds the quantum dot resonance linewidth, degeneracy dependent plateaus emerge. These are reproduced by sequential tunneling calculations. In the other case with large asymmetry in the tunnel couplings, the high frequency response is two orders of magnitude larger than the low frequency conductance G, favoring the high frequency readout.
description: 12 pages 5 figures
Agriculture and the WTO: Future Directions in the Grain and Oilseed Sectors
Creators: name: Gray, Richard S.
name: Gray, Richard S.
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: carbon sequestration
subject: food security
subject: grain
subject: Kyoto Accord
subject: oilseed

description: This paper examines the larger economic forces that shape multilateral trade agreements and concludes that further WTO trade reform in the grain and oilseed sectors will be difficult to achieve. The somewhat successful Uruguay Round had budget and internal reform pressure to assist the process. The United States currently has large budget surpluses, and efficiency effects from policy reform following the Uruguay Round have reduced the possible gains from further domestic reform. Without these pressures, further negotiated reform in the grain and oilseed sectors is a remote possibility. On the other hand, there are good prospects for a multilateral environmental agreement on climate change. Ratification of a climate change agreement could have a large impact on the grain and oilseed sectors as such an agreement would divert excess resources from food production.
The interplay between feedback, accretion, transport and winds in setting gas-phase metal distribution in galaxies
Creators: name: Sharda, Piyush
name: Ginzburg, Omri
name: Krumholz, Mark R.
name: Forbes, John C.
name: Wisnioski, Emily
name: Mingozzi, Matilde
name: Zovaro, Henry R. M.
name: Dekel, Avishai
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The recent decade has seen an exponential growth in spatially-resolved metallicity measurements in the interstellar medium (ISM) of galaxies. To first order, these measurements are characterised by the slope of the radial metallicity profile, known as the metallicity gradient. In this work, we model the relative role of star formation feedback, gas transport, cosmic gas accretion, and galactic winds in driving radial metallicity profiles and setting the mass-metallicity gradient relation (MZGR). We include a comprehensive treatment of these processes by including them as sources that supply mass, metals, and energy to marginally unstable galactic discs in pressure and energy balance. We show that both feedback and accretion that can drive turbulence and enhance metal-mixing via diffusion are crucial to reproduce the observed MZGR in local galaxies. Metal transport also contributes to setting metallicity profiles, but it is sensitive to the strength of radial gas flows in galaxies. While the mass loading of galactic winds is important to reproduce the mass metallicity relation (MZR), we find that metal mass loading is more important to reproducing the MZGR. Specifically, our model predicts preferential metal enrichment of galactic winds in low-mass galaxies. This conclusion is robust against our adopted scaling of the wind mass-loading factor, uncertainties in measured wind metallicities, and systematics due to metallicity calibrations. Overall, we find that at $z \sim 0$, galactic winds and metal transport are more important in setting metallicity gradients in low-mass galaxies whereas star formation feedback and gas accretion dominate setting metallicity gradients in massive galaxies.
description: 21 pages (+ appendix), 11 figures, 4 tables. Accepted by MNRAS
Are Disciplines Required on Domestic Support?
Creators: name: Blandford, David
name: Blandford, David
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: agriculture
subject: domestic support
subject: green box
subject: WTO

description: The impact of domestic support on trade is likely to become an increasingly important issue in the WTO negotiations on agriculture. Domestic support expenditures are increasing and existing disciplines on forms and levels of support are weak. While a shift from market price support to output subsidies should be less trade distorting, such support may not be minimally distorting as required under the so-called green-box criteria. Proposals submitted by WTO members could further expand permissible support measures and weaken disciplines on their use. In some cases, most notably support provided in pursuit of environmental objectives, there may be a contradiction between the aims of support measures and the requirement that these should be minimally trade distorting. Clearer policy criteria and stronger disciplines are needed in order to avoid future trade disputes on agricultural support.
Trade Liberalisation and the Red Meat Sector
Creators: name: Kerr, William A.
name: Kerr, William A.
Publisher: name: Unknown
Year: 2001
Subjects: subject: International Relations/Trade
subject: antidumping
subject: Argentina
subject: countervail
subject: red meat
subject: SPS

description: Trade liberalisation in the livestock sector is not likely to benefit to any great degree from the trade negotiations on agriculture at the WTO that commenced in the spring of 2000. This is because the major barriers to trade in livestock and red meat are not related to tariffs and other traditional border measures that restrict trade or subsidisation; rather, they are governed by the WTO's SPS Agreement and the GATT's contingency protection provisions relating to dumping and countervailing duties. Negotiations on these issues will have to await a general WTO negotiating round. As SPS and contingency protection questions have many interested sectors, progress is likely to be slow and the prospects for further formal liberalisation remote in the near future. In these circumstances, private sector initiatives to defuse trade problems before they start is a strategy that should be continued and expanded.
A New Algorithm for the Detection of Inter-cluster Galaxy Filaments using Galaxy Orientation Alignments
Creators: name: Pimbblet, Kevin A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new algorithm to detect inter-cluster galaxy filaments based upon the assumption that the orientations of constituent galaxies along such filaments are non-isotropic. We apply the algorithm to the 2dF Galaxy Redshift Survey catalogue and find that it readily detects many straight filaments between close cluster pairs. At large inter-cluster separations (>15 Mpc), we find that the detection efficiency falls quickly, as it also does with more complex filament morphologies. We explore the underlying assumptions and suggest that it is only in the case of close cluster pairs that we can expect galaxy orientations to be significantly correlated with filament direction.
description: 7 pages, 5 figures, accepted for publication in MNRAS
Multi-code Benchmark on Simulated Ti K-edge X-ray Absorption Spectra of Ti-O Compounds
Creators: name: Meng, Fanchen
name: Maurer, Benedikt
name: Peschel, Fabian
name: Selcuk, Sencer
name: Hybertsen, Mark
name: Qu, Xiaohui
name: Vorwerk, Christian
name: Draxl, Claudia
name: Vinson, John
name: Lu, Deyu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: X-ray absorption spectroscopy (XAS) is an element-specific materials characterization technique that is sensitive to structural and electronic properties. First-principles simulated XAS has been widely used as a powerful tool to interpret experimental spectra and draw physical insights. Recently, there has also been growing interest in building computational XAS databases to enable data analytics and machine learning applications. However, there are non-trivial differences among commonly used XAS simulation codes, both in underlying theoretical formalism and in technical implementation. Reliable and reproducible computational XAS databases require systematic benchmark studies. In this work, we benchmarked Ti K-edge XAS simulations of ten representative Ti-O binary compounds, which we refer to as the Ti-O-10 dataset, using three state-of-the-art codes: xspectra, ocean and exciting. We systematically studied the convergence behavior with respect to the input parameters and developed a workflow to automate and standardize the calculations to ensure converged spectra. Our benchmark comparison shows: (1) the two Bethe-Salpeter equation (BSE) codes (ocean and exciting) have excellent agreement in the energy range studied (up to 35 eV above the onset) with an average Spearman's rank correlation score of 0.998; (2) good agreement is obtained between the core-hole potential code (xspectra) and BSE codes (ocean and exciting) with an average Spearman's rank correlation score of 0.990. Our benchmark study provides important standards for first-principles XAS simulations with broad impact in data-driven XAS analysis.
description: 32 pages, 11 figures and 7 tables