cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Extreme first passage times for random walks on networks
Creators: name: Lawley, Sean D
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G70, 60J27

description: Many biological, social, and communication systems can be modeled by ``searchers'' moving through a complex network. For example, intracellular cargo is transported on tubular networks, news and rumors spread through online social networks, and the rapid global spread of infectious diseases occurs through passengers traveling on the airport network. To understand the timescale of search/transport/spread, one commonly studies the first passage time (FPT) of a single searcher (or ``spreader'') to a target. However, in many scenarios the relevant timescale is not the FPT of a single searcher to a target, but rather the FPT of the fastest searcher to a target out of many searchers. For example, many processes in cell biology are triggered by the first molecule to find a target out of many, and the time it takes an infectious disease to reach a particular city depends on the first infected traveler to arrive out of potentially many infected travelers. Such fastest FPTs are called extreme FPTs. In this paper, we study extreme FPTs for a general class of continuous-time random walks on networks (which includes continuous-time Markov chains). In the limit of many searchers, we find explicit formulas for the probability distribution and all the moments of the $k$th fastest FPT. These rigorous formulas depend only on network parameters along a certain geodesic path(s) from the starting location to the target since the fastest searchers take a direct route to the target. Furthermore, our results allow one to estimate if a particular system is in a regime characterized by fast extreme FPTs. We also prove similar results for mortal searchers on a network that are conditioned to find the target before a fast inactivation time. We illustrate our results with numerical simulations and uncover potential pitfalls of modeling diffusive or subdiffusive processes involving extreme statistics.
description: 33 pages, 4 figures
Stokes--anti-Stokes light scattering process: -- A photon-wave-function approach
Creators: name: Guimarães, A. V. A.
name: Santos, M. F.
name: Jorio, A.
name: Monken, C. H.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The Photon wave function Formalism provides an alternative description of some quantum optical phenomena in a more intuitive way. We use this formalism to describe the process of correlated Stokes--anti-Stokes Raman scattering. In this process, two photons from a laser beam are inelastically scattered by a phonon created by the first photon (Stokes processes) and annihilated by the second photon (anti-Stokes process), producing a Stokes--anti-Sokes (SaS) photon pair. We arrive at an expression for the two-photon wave function of the scattered SaS photon pair, which is in agreement with a number of experimental results.
description: 8 pages, 1 figure
Global Hunger Index: The Challenge of Hunger 2008
Creators: name: Von Grebmer, Klaus
name: Fritschel, Heidi
name: Nestorova, Bella
name: Olofinbiyi, Tolulope
name: Pandya-Lorch, Rajul
name: Yohannes, Yisehac
name: Von Grebmer, Klaus
name: Fritschel, Heidi
name: Nestorova, Bella
name: Olofinbiyi, Tolulope
name: Pandya-Lorch, Rajul
name: Yohannes, Yisehac
Publisher: name: Unknown
Year: 2008
Subjects: Food Security and Poverty

description: The 2008 Global Hunger Index (GHI) shows that the world has made slow progress in reducing food insecurity since 1990, with dramatic differences among regions and countries. In the nearly two decades since 1990, some regions — South and Southeast Asia, the Near East and North Africa, and Latin America and the Caribbean — have made significant headway in improving food security. Nevertheless, the GHI remains high in South Asia. The GHI is similarly high in Sub-Saharan Africa, where progress has been marginal since 1990. The GHI level in the world as a whole remains serious. The countries with the most worrisome hunger status and the highest 2008 GHI scores are predominantly in Sub-Saharan Africa, with the Democratic Republic of Congo, Eritrea, Burundi, Niger, and Sierra Leone at the bottom of the list. Several dozen countries in various regions have GHI scores categorized as low. Hunger is closely tied to poverty, and countries with high levels of hunger are overwhelmingly low- or low-middle-income countries. Sub-Saharan Africa and South Asia are the regions with the highest GHI scores and the highest poverty rates. The recent advent of higher food prices has uneven effects across countries, depending on a range of factors, including whether countries are net importers or exporters of food. Among the countries for which the GHI is calculated, net cereal importers, for example, greatly outnumber exporters, implying that many more countries combating hunger are likely to suffer from higher prices than benefit from them. Higher food prices have also caused violent and nonviolent protests in dozens of countries. In this context of higher food prices, prospects for improving food and nutrition security do not appear favorable, given that at least 800 million people were food insecure even before the food price crisis hit. Higher food prices cut into poor households’ food budgets, with particularly serious risks for undernourished infants and children. High prices also reduce the amount of food aid that donors can supply with a given amount of funds. Combating the food crisis will require more food aid for poor people; much greater investments in agriculture, especially the small farm sector; more investment in social protection programs and social sectors like education and health; reforms to create a fair world trading system; changes to biofuel policies; measures to calm global food markets; better data collection and improved monitoring of the food and nutrition situation; and more support for nongovernmental organizations that work on behalf of poor people in developing countries.
Cannon-Thurston Maps for Surface Groups I: Amalgamation Geometry and Split Geometry
Creators: name: Mj, Mahan
Publisher: name: arXiv
Year: 2005
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M50

description: We introduce the notion of manifolds of amalgamation geometry and its generalization, split geometry. We show that the limit set of any surface group of split geometry is locally connected, by constructing a natural Cannon-Thurston map.
description: v 5: 73 pages, 7 figures. References updated. Subsection on partial electrocution modified. Introductory comments added
Living on the margin: Assessing the economic impacts of Landcare in the Philippine uplands
Creators: name: Newby, Jonathan C.
name: Cramb, Rob A.
name: Newby, Jonathan C.
name: Cramb, Rob A.
Publisher: name: Unknown
Year: 2009
Subjects: subject: Landcare
subject: Philippines
subject: livelihoods
subject: poverty
subject: watershed
subject: ACIAR

description: In the Philippines, about 38 per cent of the population resides in rural areas where poverty remains a significant problem. In 2006, 47 per cent of all households in Bohol Province fell below the national poverty line, with the percentage even higher in upland communities. These households often exist in marginal landscapes that are under significant pressure from ongoing resource degradation and rising input costs. This paper first explores whether the adoption of Landcare practices in a highly degraded landscape has resulted in improved livelihood outcomes for upland farming families in Bohol. Second, it analyses the potential for the piecemeal adoption of these measures to deliver tangible benefits at the watershed scale. Finally, using a BCA approach, these outcomes are compared to the costs of the research and extension projects that have helped achieve them.
Sliding Window Algorithms for k-Clustering Problems
Creators: name: Borassi, Michele
name: Epasto, Alessandro
name: Lattanzi, Silvio
name: Vassilvitskii, Sergei
name: Zadimoghaddam, Morteza
Publisher: name: arXiv
Year: 2020
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: The sliding window model of computation captures scenarios in which data is arriving continuously, but only the latest $w$ elements should be used for analysis. The goal is to design algorithms that update the solution efficiently with each arrival rather than recomputing it from scratch. In this work, we focus on $k$-clustering problems such as $k$-means and $k$-median. In this setting, we provide simple and practical algorithms that offer stronger performance guarantees than previous results. Empirically, we show that our methods store only a small fraction of the data, are orders of magnitude faster, and find solutions with costs only slightly higher than those returned by algorithms with access to the full dataset.
description: 43 pages, 7 figures
ROLE OF COMPETENCY IN THE TRANSFORMATIONAL LEADERSHIP  OF MATHEMATICS TEACHERS
Creators: name: BASCONCILLO, MELANY
Publisher: name: Zenodo
Year: 2024
Subjects: competency, transformational leadership, mathematics teachers, professional development, leadership effectiveness, instructional strategies

description: In recent years, the importance of transformational leadership in education has garnered significant attention, particularly as schools strive to meet the evolving demands of students. For Mathematics teachers, their leadership role extends beyond the classroom, requiring them to demonstrate strong competencies that can inspire both students and colleagues. This study aimed to explore how the competency of Mathematics teachers impacts their transformational leadership abilities. Specifically, it sought to assess how critical skills, such as problem-solving and instructional strategies, enhance their leadership effectiveness and promote a motivating and supportive learning environment. This study examined the role of competency in the transformational leadership of Mathematics teachers, focusing on how their skillset influenced leadership effectiveness in educational settings. The research assessed how their competencies such as problem-solving and instructional strategies, contributed to their ability to inspire and motivate students and colleagues. Data were gathered from Mathematics teachers in secondary schools, and results revealed that higher competency levels correlated with improved leadership outcomes. Additionally, the study highlighted specific areas for development, suggesting that enhancing teacher competencies can boost transformational leadership. This research emphasized the need for professional development programs to support the continuous growth of Mathematics teachers as effective leaders.
CHARACTERISTICS OF DIFFERENT CONSUMER SEGMENTS IN THE AUSTRALIAN BEEF MARKET
Creators: name: Morales, Luis Emilio
name: Griffith, Garry R.
name: Wright, Vic
name: Umberger, Wendy J.
name: Fleming, Euan M.
name: Morales, Luis Emilio
name: Griffith, Garry R.
name: Wright, Vic
name: Umberger, Wendy J.
name: Fleming, Euan M.
Publisher: name: Unknown
Year: 2009
Subjects: subject: Beef Branding
subject: Consumer Preferences
subject: Segmentation
subject: Focus Groups.

description: Beef consumers in Australia have shown differences in their preferences for products and sensitivity to price. This can be explained by the influence on expected quality of cues related to health, production process and eating experience. Eating experience is difficult to predict as consumers generally do not have enough information to form reliable expectations. In this context, branded beef can help to signal quality and reduce the degree of uncertainty that consumers experience when shopping. Focus group research identified different segments, premiums for preferred products and potential for large-scale differentiation and branding in the Australian market.
Photoacoustic image synthesis with generative adversarial networks
Creators: name: Schellenberg, Melanie
name: Gröhl, Janek
name: Dreher, Kris K.
name: Nölke, Jan-Hinrich
name: Holzwarth, Niklas
name: Tizabi, Minu D.
name: Seitel, Alexander
name: Maier-Hein, Lena
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Medical Physics (physics.med-ph)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Photoacoustic tomography (PAT) has the potential to recover morphological and functional tissue properties with high spatial resolution. However, previous attempts to solve the optical inverse problem with supervised machine learning were hampered by the absence of labeled reference data. While this bottleneck has been tackled by simulating training data, the domain gap between real and simulated images remains an unsolved challenge. We propose a novel approach to PAT image synthesis that involves subdividing the challenge of generating plausible simulations into two disjoint problems: (1) Probabilistic generation of realistic tissue morphology, and (2) pixel-wise assignment of corresponding optical and acoustic properties. The former is achieved with Generative Adversarial Networks (GANs) trained on semantically annotated medical imaging data. According to a validation study on a downstream task our approach yields more realistic synthetic images than the traditional model-based approach and could therefore become a fundamental step for deep learning-based quantitative PAT (qPAT).
description: 10 pages, 6 figures, 2 tables, update with paper published at Photoacoustics
Time complexity of in-memory solution of linear systems
Creators: name: Sun, Zhong
name: Pedretti, Giacomo
name: Mannocci, Piergiulio
name: Ambrosi, Elia
name: Bricalli, Alessandro
name: Ielmini, Daniele
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Complexity (cs.CC)
subject: Emerging Technologies (cs.ET)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: In-memory computing with crosspoint resistive memory arrays has been shown to accelerate data-centric computations such as the training and inference of deep neural networks, thanks to the high parallelism endowed by physical rules in the electrical circuits. By connecting crosspoint arrays with negative feedback amplifiers, it is possible to solve linear algebraic problems such as linear systems and matrix eigenvectors in just one step. Based on the theory of feedback circuits, we study the dynamics of the solution of linear systems within a memory array, showing that the time complexity of the solution is free of any direct dependence on the problem size N, rather it is governed by the minimal eigenvalue of an associated matrix of the coefficient matrix. We show that, when the linear system is modeled by a covariance matrix, the time complexity is O(logN) or O(1). In the case of sparse positive-definite linear systems, the time complexity is solely determined by the minimal eigenvalue of the coefficient matrix. These results demonstrate the high speed of the circuit for solving linear systems in a wide range of applications, thus supporting in-memory computing as a strong candidate for future big data and machine learning accelerators.
description: Accepted by IEEE Trans. Electron Devices. The authors thank Scott Aaronson for helpful discussion about time complexity
Orbital Chern Insulator at $ν=-2$ in Twisted MoTe$_{2}$
Creators: name: Fan, Feng-Ren
name: Xiao, Cong
name: Yao, Wang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In twisted MoTe$_{2}$, latest transport measurement has reported observation of quantum anomalous Hall effect at hole filling $ν=-1$, which undergoes a topological phase transition to a trivial ferromagnet as layer hybridization gets suppressed by interlayer bias $D$. Here we show that this underlies the existence of an orbital Chern insulating state with gate ($D$) switchable sign in an antiferromagtic spin background at hole filling $ν=-2$. From momentum-space Hartree Fock calculations, we find this state has a topological phase diagram complementary to that of the $ν=-1$ one: by sweeping $D$ from negative to positive, the Chern number of this $ν=-2$ state can be switched between $+1$, $0$, and $-1$, accompanied by a sign change of a sizable orbital magnetization. In range of $D$ where this antiferronagnet is the ground state, the orbital magnetization allows magnetic field initialization of the spin antiferromagnetic order and the Chern number.
description: 6 pages, 4 figures
Water harvesting options in the drylands at different spatial scales
Creators: name: Ali, Akhtar
name: Oweis, Theib
name: Rashid, Mohammad
name: El-Naggar, Sobhi
name: Aal, Atef Abdul
name: Ali, Akhtar
name: Oweis, Theib
name: Rashid, Mohammad
name: El-Naggar, Sobhi
name: Aal, Atef Abdul
Publisher: name: Unknown
Year: 2007
Subjects: Resource /Energy Economics and Policy

description: The effect of spatial-scale variations on water harvesting has been evaluated at micro-catchment, hillside/farm, and watershed (=catchment) scales in three relatively dry environments in Syria, Pakistan and Egypt. Micro-catchment water harvesting captures localized runoff only through independent micro-catchment systems and is not influenced by hill slope runoff and stream flows. In Syria, it was found that only a fraction of total runoff from a catchment is collected, with no significant effect on water supply downstream. Therefore, it is less sensitive to spatial-scale variations (rainfall, topography, soils) and it is less likely to create upstream-downstream water-use conflicts. Micro-catchment water harvesting established fodder shrubs, with 3-7 fold growth improvement and 27 to 90% survival rate. In contrast, spatial rainfall and geo-hydrological variations greatly influenced the potential of water harvesting at the watershed scale in north-west Egypt. The study revealed the importance of scientific data and appropriate assessment methods. Due to potential socio-economic disputes, the institutional arrangements for water allocation and conflict resolution are critical at this scale. At the farm scale, the low-cost farm runoff structures (US$ 48 per structure), effectively regulated the runoff, reduced terrace damage and improved field soil moisture, and were shown to be suitable for water harvesting on terraces in Barani, Pakistan. The study infers that water harvesting in the drylands is a viable option to improve productivity and conserve natural resources, if it is appropriately implemented. Nevertheless, the size of the water harvesting system and the spatial scale at which it is to be implemented determine the options for water harvesting.
Split-step Fourier methods for the Gross-Pitaevskii equation
Creators: name: Javanainen, Juha
name: Ruostekoski, Janne
Publisher: name: arXiv
Year: 2004
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We perform a systematic study of the accuracy of split-step Fourier transform methods for the time dependent Gross-Pitaevskii equation using symbolic calculation. Provided the most recent approximation for the wave function is always used in the nonlinear atom-atom interaction potential energy, every split-step algorithm we have tried has the same-order time stepping error for the Gross-Pitaevskii equation and the Schroedinger equation.
description: 3 pages
Land-water interactions in five contrasting dairying catchments: issues and solutions
Creators: name: Wilcock, Robert J.
name: Monaghan, Ross M.
name: Thorrold, Bruce S.
name: Meredith, Adrian S.
name: Betteridge, Keith
name: Duncan, Maurice J.
name: Wilcock, Robert J.
name: Monaghan, Ross M.
name: Thorrold, Bruce S.
name: Meredith, Adrian S.
name: Betteridge, Keith
name: Duncan, Maurice J.
Publisher: name: Unknown
Year: 2007
Subjects: Resource /Energy Economics and Policy

description: Monitoring of five dairy farming catchment streams in New Zealand shows they have high concentrations of N and P forms and faecal indicator bacteria. Suspended solids (SS) concentrations are sometimes high because of poor riparian management. Trend analysis and specific yields of N, P and SS for two streams that have been monitored for five years indicates that little change has occurred in water quality. However, improved water quality has been detected in the trends for two streams that have been monitored for 10 years, as a result of reductions in point sources and improved stock management (less intensive grazing and better stream bank fencing) that have taken place over the longer period. Surveys of farm management practices have been conducted at two-yearly intervals and best management practices are recommended for farming in each catchment, based on identified linkages between land use and water quality.
Controlling the microstructure and phase behavior of confined soft colloids by active interaction switching
Creators: name: Moncho-Jordá, Arturo
name: Dzubiella, Joachim
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We explore the microstructure and phase behavior of confined soft colloids which can actively switch their interactions at a predefined kinetic rate. For this, we employ a reaction-diffusion approach based on a reactive dynamical density-functional theory (R-DDFT) and study the effect of a binary (two-state) switching of the size of colloids interacting with a Gaussian pair potential. The rate of switching interpolates between a near-equilibrium binary Gaussian mixture at low rates and an effective monodisperse liquid for large rates, hence strongly affecting the one-body density profiles, adsorption, and pressure at confining walls. Importantly, we demonstrate that sufficiently fast switching impedes the phase separation of an (in equilibrium) unstable liquid, allowing the dynamic control of the degree of mixing/condensation and local micro-structuring in a cellular confinement by tuning the switching rate.
description: 5 pages, 3 figures, 1 supplemental material (pdf) file
Analogue quantum gravity phenomenology from a two-component Bose-Einstein condensate
Creators: name: Liberati, Stefano
name: Visser, Matt
name: Weinfurtner, Silke
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present an analogue spacetime model that reproduces the salient features of the most common ansatz for quantum gravity phenomenology. We do this by investigating a system of two coupled Bose-Einstein condensates. This system can be tuned to have two "phonon" modes (one massive, one massless) which share the same limiting speed in the hydrodynamic approximation [Phys. Rev. D72 (2005) 044020, gr-qc/0506029; cond-mat/0409639]. The system nevertheless possesses (possibly non-universal) Lorentz violating terms at very high energies where "quantum pressure" becomes important. We investigate the physical interpretation of the relevant fine-tuning conditions, and discuss the possible lessons and hints that this analogue spacetime could provide for the phenomenology of real physical quantum gravity. In particular we show that the effective field theory of quasi-particles in such an emergent spacetime does not exhibit the so called "naturalness problem".
description: V1: 36 pages, uses iopart.sty; V2: 31 pages, presentation simplified, conclusions clarified, discussion of some side issues eliminated, several references added, this version to appear in Classical and Quantum Gravity
Pressure drag reduction via imposition of spanwise wall oscillations on a rough wall
Creators: name: Deshpande, Rahul
name: Kidanemariam, Aman G.
name: Marusic, Ivan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The present study tests the efficacy of the well-known viscous drag reduction strategy of imposing spanwise wall oscillations to reduce pressure drag contributions in a transitional- and fully-rough turbulent wall flow. This is achieved by conducting a series of direct numerical simulations of a turbulent flow over two-dimensional (spanwise aligned) semi-cylindrical rods, placed periodically along the streamwise direction with varying streamwise spacing. Surface oscillations, imposed at fixed viscous-scaled actuation parameters optimum for smooth wall drag reduction, are found to yield substantial drag reduction (>25%) for all the rough wall cases, maintained at matched roughness Reynolds numbers. While the total drag reduction is due to a drop in both viscous and pressure drag in the case of transitionally-rough flow (i.e. with large inter-rod spacing), it is solely associated with pressure drag reduction for the fully-rough cases (i.e. with small inter-rod spacings), with the latter being reported for the first time. The study finds that pressure drag reduction in all cases is caused by the attenuation of the vortex shedding activity in the roughness wake, in response to wall-oscillation frequencies that are of the same order as the vortex shedding frequencies. Contrary to speculations in the literature, this study confirms that the mechanism behind pressure drag reduction, achieved via imposition of spanwise oscillations, is independent from the viscous drag reduction. This mechanism is responsible for weakening of the Reynolds stresses and increase in base pressure in the roughness wake, explaining the pressure drag reduction observed by past studies, across varying roughness heights and geometries.
description: Manuscript accepted in the Journal of Fluid Mechanics comprising 20 pages, 7 figures
Charge-Symmetry-Breaking Three-Nucleon Forces
Creators: name: Friar, J. L.
name: Payne, G. L.
name: van Kolck, U.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Leading-order three-nucleon forces that violate isospin symmetry are calculated in Chiral Perturbation Theory. The effect of the charge-symmetry-breaking three-nucleon force is investigated in the trinucleon systems using Faddeev calculations. We find that the contribution of this force to the 3He - 3H binding-energy difference is approximately 5 keV.
description: 14 pages, 3 figures
Virtual sanctuar : geographies of pro-anorexia websites
Creators: name: Dias, Karen Lynn
Publisher: name: University of British Columbia
Year: 2009

description: Eating 'disorders' and body image disturbances are increasingly prevalent among girls and women in Western industrialized societies and globally. This thesis explores cyberspace as a potential 'safer' space where girls and women who are struggling with anorexia or other eating 'disorders' can potentially find sanctuary from the surveillance and regulatory mechanisms of control in the public sphere or 'realspace.' In contrast to dominant biomedical and psychiatric discourses of anorexia that often portray women with eating disorders as 'irrational' and 'in denial' of their behavior, this study takes seriously the voices of these women and looks to their narratives for alternative presentations of anorexia and other eating disorders. It attempts to locate women's cyberspace expressions of anorexia in the context of a society that often pathologizes, medicalizes and attempts to silence their voices. The thesis examines the narratives of women who create and visit 'pro-anorexia' or 'pro-ana' websites to see if dominant cultural scripts about women's bodies and subjectivities are reproduced, negotiated and/or resisted. It investigates women's expressions and interpretations of their own experiences of anorexia and other eating disorders. It reviews data collected from pro-anorexia websites from September 2001 to February 2003 and considers the backlash they generate. It explores the rationale of girls and women who inhabit these new social spaces, and their resilience in spite of backlash. Narratives found on pro-anorexia websites may illustrate alternative discourses of anorexia and eating disorders that have implications for biomedical theories as well as clinical practices.
Neutrino Masses in the Effective Rank-5 Subgroups of E_6 II: Supersymmetric Case
Creators: name: Frank, Mariana
name: Turan, Ismail
name: Sher, Marc
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a complete analysis of the neutral fermion sector of supersymmetric E_6-inspired low energy models containing an extra SU(2), concentrating on the Alternate Left-Right and Inert models. We show that the R-parity conserving scenario always exhibits a large Dirac mass for ν_L with maximal mixing with an isosinglet neutrino, and that R-parity violating scenarios do not change the picture other than allowing further mixing with another isosinglet. In order to recover Standard Model phenomenology, additional assumptions in the form of discrete symmetries and/or new interactions are needed. We introduce and investigate Discrete Symmetry method and Higher Dimensional Operators as mechanisms for solving the neutrino mass and mixing problems in these models.
description: 27 pages, 2 figures; typos correted, version to be published in Physical Review D
FROM STRUGGLE TO SUCCESS: HOW TO STAY INSPIRED WHILE LEARNING ENGLISH
Creators: name: Yuldoshev, Khaydarbek
Publisher: name: Zenodo
Year: 2025

description: Learning English as a Foreign Language (EFL) can be a challenging yet rewarding journey. Many learners struggle with motivation, confidence, and consistency. This article explores effective strategies for staying inspired while learning English. By implementing goal-setting techniques, engaging in immersive learning experiences, and utilizing modern technology, learners can transform their struggles into success.
Multiscale Thermodynamics: Energy, Entropy, and Symmetry from Atoms to Bulk Behavior
Creators: name: Chamberlin, Ralph V.
name: Clark, Michael R.
name: Mujica, Vladimiro
name: Wolf, George H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: Here we investigate how local properties of particles in a thermal bath influence the thermodynamics of the bath. We utilize nanothermodynamics, based on two postulates: that small systems can be treated self-consistently by coupling to an ensemble of similarly small systems, and that a large ensemble of small systems forms its own thermodynamic bath. We adapt these ideas to study how a large system may subdivide into an ensemble of smaller subsystems, causing internal heterogeneity across multiple size scales. For the semi-classical ideal gas, maximum entropy favors subdividing a large system of atoms into regions of variable size. The mechanism of region formation could come from quantum exchange that makes atoms in each region indistinguishable, while decoherence between regions allows atoms in separate regions to be distinguishable by location. Combining regions reduces the total entropy, as expected when distinguishable particles become indistinguishable, and as required by theorems for sub-additive entropy. Combining large volumes of small regions gives the entropy of mixing for a semi-classical ideal gas, resolving Gibbs paradox without invoking quantum symmetry for distant atoms. Other models we study are based on Ising-like spins in 1-D. We find similarity in the properties of a two-state model in the nanocanonical ensemble and a three-state model in the canonical ensemble. Thus, emergent phenomena may alter the thermal behavior of microscopic models, and the correct ensemble is necessary for fully-accurate predictions. We add a nonlinear correction to Boltzmann's factor in simulations of the Ising-like spins to imitate the dynamics of spin exchange on intermediate lengths, yielding the statistics of indistinguishable states. These simulations exhibit 1/f-like noise at low frequencies (f), and white noise at higher f, similar to the thermal fluctuations found in many materials.
description: 23 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:2007.13031
General Formula for the Green's Function Approach to the Spin-1/2 Antiferromagnetic Heisenberg Model
Creators: name: Sasamoto, Daiki
name: Morinari, Takao
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A wide range of analytical and numerical methods are available to study quantum spin systems. However, the complexity of spin correlations and interactions limits their applicability to specific temperature ranges. The analytical approach utilizing Green's function has proved advantageous, as it allows for formulation without restrictions on the presence of long-range order and facilitates estimation of the spin excitation spectrum and thermodynamic quantities across the entire temperature range. In this work, we present a generalized formulation of the Green's function method that can be applied to diverse spin systems. As specific applications, we consider the hypercubic lattice and the $J_1$-$J_2$ model. For the cubic lattice case, the Green's function approach provides a good estimation for the transition temperature. Regarding the $J_1$-$J_2$ model, we include nematic correlations in the analysis and find no signature of such correlations, though accurate numerical calculations are required in the presence of strong frustration. Although our focus is on the spin one-half antiferromagnetic Heisenberg model on an arbitrary lattice, the Green's function approach can be generalized to incorporate other interactions and higher spin values.
description: 10 pages, 9 figures
Multi-band programmable gain Raman amplifier
Creators: name: de Moura, Uiara Celine
name: Iqbal, Md Asif
name: Kamalian, Morteza
name: Krzczanowicz, Lukasz
name: Da Ros, Francesco
name: Brusin, Ann Margareth Rosa
name: Carena, Andrea
name: Forysiak, Wladek
name: Turitsyn, Sergei
name: Zibar, Darko
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Optical communication systems, operating in C-band, are reaching their theoretically achievable capacity limits. An attractive and economically viable solution to satisfy the future data rate demands is to employ the transmission across the full low-loss spectrum encompassing O, E, S, C and L band of the single mode fibers (SMF). Utilizing all five bands offers a bandwidth of up to $\sim$53.5THz (365nm) with loss below 0.4dB/km. A key component in realizing multi-band optical communication systems is the optical amplifier. Apart from having an ultra-wide gain profile, the ability of providing arbitrary gain profiles, in a controlled way, will become an essential feature. The latter will allow for signal power spectrum shaping which has a broad range of applications such as the maximization of the achievable information rate X distance product, the elimination of static and lossy gain flattening filters (GFF) enabling a power efficient system design, and the gain equalization of optical frequency combs. In this paper, we experimentally demonstrate a multi-band (S+C+L) programmable gain optical amplifier using only Raman effects and machine learning. The amplifier achieves >1000 programmable gain profiles within the range from 3.5 to 30 dB, in an ultra-fast way and a very low maximum error of 1.6e-2 dB/THz over an ultra-wide bandwidth of 17.6-THz (140.7-nm).
description: 10 pages, 8 figures
Search for the gamma-ray spectral lines with the DAMPE and the Fermi-LAT observations
Creators: name: Cheng, Ji-Gui
name: Liang, Yun-Feng
name: Liang, En-Wei
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Weakly interacting massive particles, as a major candidate of dark matter (DM), may directly annihilate or decay into high-energy photons, producing monochromatic spectral lines in the gamma-ray band. These spectral lines, if detected, are smoking-gun signatures for the existence of new physics. Using the 5 years of DAMPE and 13 years of Fermi-LAT data, we search for line-like signals in the energy range of 3 GeV to 1 TeV from the Galactic halo. Different regions of interest are considered to accommodate different DM density profiles. We do not find any significant line structure, and the previously reported line-like feature at $\sim$133 GeV is also not detected in our analysis. Adopting a local DM density of $ρ_{\rm local}=0.4\,{\rm GeV\,cm^{-3}}$, we derive 95% confidence level constraints on the velocity-averaged cross-section of $\langle{σv}\rangle_{γγ} \lesssim 4 \times 10^{-28}\,{\rm cm^{3}\,s^{-1}}$ and the decay lifetime of $τ_{γν} \gtrsim 5 \times 10^{29}\,{\rm s}$ at 100 GeV, achieving the strongest constraints to date for the line energies of 6-660 GeV. The improvement stems from the longer Fermi-LAT data set used and the inclusion of DAMPE data in the analysis. The simultaneous use of two independent data sets could also reduce the systematic uncertainty of the search.
description: 14 pages, 10 figures. Accepted for publication in PRD
Luminosity determination using Z boson production at the CMS experiment
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13 TeV. Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same data set, in small intervals of 2 pb$^{-1}$ of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity.
description: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/LUM-21-001 (CMS Public Pages)
Spectral curves and the mass of hyperbolic monopoles
Creators: name: Norbury, Paul
name: Romão, Nuno M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences
subject: 32L25; 14H70

description: The moduli spaces of hyperbolic monopoles are naturally fibred by the monopole mass, and this leads to a nontrivial mass dependence of the holomorphic data (spectral curves, rational maps, holomorphic spheres) associated to hyperbolic multi-monopoles. In this paper, we obtain an explicit description of this dependence for general hyperbolic monopoles of magnetic charge two. In addition, we show how to compute the monopole mass of higher charge spectral curves with tetrahedral and octahedral symmetries. Spectral curves of euclidean monopoles are recovered from our results via an infinite-mass limit.
description: 43 pages, LaTeX, 3 figures
Ilm-fan ta'limi, ta'lim tizimining muammolari va istiqbollar
Creators: name: Saidova, Zebiniso Rustam qizi
Publisher: name: Zenodo
Year: 2025

description: Ushbu maqolada inson kapitalining milliy iqtisodiyotdagi o‘rni va uning raqobatbardoshlikni oshirishdagi ahamiyati yoritilgan. Inson kapitali tarkibi ta’lim, salomatlik, malaka va raqamli ko‘nikmalar kabi jihatlardan iborat bo‘lib, ularning rivoji iqtisodiy samaradorlikni ta’minlaydi. Ta’lim tizimini modernizatsiya qilish, tibbiyot xizmatlarini yaxshilash va texnologik savodxonlikni oshirish inson kapitalini rivojlantirishning muhim yo‘nalishlari sifatida ko‘rsatilgan. Innovatsion iqtisodiy modelga o‘tish va ishchi kuchini global talablar asosida moslashtirish orqali iqtisodiy o‘sish va ijtimoiy barqarorlikka erishish mumkinligi ta’kidlangan. Mazkur maqola inson kapitalini rivojlantirishning milliy iqtisodiyot uchun strategik ahamiyatini ko‘rsatadi.
In-memory eigenvector computation in time O(1)
Creators: name: Sun, Zhong
name: Pedretti, Giacomo
name: Ambrosi, Elia
name: Bricalli, Alessandro
name: Ielmini, Daniele
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Complexity (cs.CC)
subject: Emerging Technologies (cs.ET)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: In-memory computing with crosspoint resistive memory arrays has gained enormous attention to accelerate the matrix-vector multiplication in the computation of data-centric applications. By combining a crosspoint array and feedback amplifiers, it is possible to compute matrix eigenvectors in one step without algorithmic iterations. In this work, time complexity of the eigenvector computation is investigated, based on the feedback analysis of the crosspoint circuit. The results show that the computing time of the circuit is determined by the mismatch degree of the eigenvalues implemented in the circuit, which controls the rising speed of output voltages. For a dataset of random matrices, the time for computing the dominant eigenvector in the circuit is constant for various matrix sizes, namely the time complexity is O(1). The O(1) time complexity is also supported by simulations of PageRank of real-world datasets. This work paves the way for fast, energy-efficient accelerators for eigenvector computation in a wide range of practical applications.
description: Accepted by Adv. Intell. Syst
A Line of Critical Points in 2+1 Dimensions: Quantum Critical Loop Gases and Non-Abelian Gauge Theory
Creators: name: Freedman, Michael
name: Nayak, Chetan
name: Shtengel, Kirill
Publisher: name: arXiv
Year: 2004
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We (1) construct a one-parameter family of lattice models of interacting spins; (2) obtain their exact ground states; (3) derive a statistical-mechanical analogy which relates their ground states to O(n) loop gases; (4) show that the models are critical for $d\leq \sqrt{2}$, where $d$ parametrizes the models; (5) note that for the special values $d=2\cos(π/(k+2))$, they are related to doubled level-$k$ SU(2) Chern-Simons theory; (6) conjecture that they are in the universality class of a non-relativistic SU(2) gauge theory; and (7) show that its one-loop $β$-function vanishes for all values of the coupling constant, implying that it is also on a critical line.
Unconventional photo-induced charge-density-wave dynamics in 2H-NbSe$_{2}$
Creators: name: Venturini, Rok
name: Sarkar, Ankita
name: Sutar, Petra
name: Jagličić, Zvonko
name: Vaskivskyi, Yevhenii
name: Goreshnik, Evgeny
name: Mihailovic, Dragan
name: Mertelj, Tomaz
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigated temperature ($T$) dependent ultrafast near-infrared (NIR) transient reflectivity dynamics in coexisting superconducting (SC) and charge density wave (CDW) phases of two-dimensional 2H-NbSe$_{2}$ using NIR and visible excitations. With visible pump-photon excitation (400 nm) we find a slow high-energy quasiparticle relaxation channel which is present in all phases. In the CDW phase, we observe a distinctive transient response component, irrespective of the pump-photon energy. The component is marked by the absence of coherent amplitude mode oscillations and a relatively slow, picosecond rise time, which is different than in most of the typical CDW materials. In the SC phase, another tiny component emerges that is associated with optical suppression of the SC phase. The transient reflectivity relaxation in the CDW phase is dominated by phonon diffusive processes with an estimated low-$T$ heat diffusion constant anisotropy of $\sim30$. Strong excitation of the CDW phase reveals a weakly non-thermal CDW order parameter (OP) suppression. Unlike CDW systems with a larger gap, where the optical OP suppression involves only a small fraction of phonon degrees of freedom, the OP suppression in 2H-NbSe$_{2}$ is characterised by the excitation of a large amount of phonon degrees of freedom and significantly slower dynamics.
Bangladesh Famine at 1974 and Effects of Changing Paper Money From 1947
Creators: name: MD. ABDULLAH YUSUF IMAM
Publisher: name: figshare
Year: 2020
Subjects: Uncategorized

description: After thePartition of Bengal in 1947, inEast Bengal, which later became the Eastern Wing ofPakistan unionand was renamed toEast Pakistanin 1956 to 16thDecember 1971. During the 1960s the State Bank of Pakistan had been introducing a new series of bank notes that carried equal amounts of Urdu and Bengali text. The newly independent Bangladesh did not find an international community with a helping hand in its moments of trial. T
Educational, institutional and governmental obstacles to protecting water resources from improper agricultural practices in Lebanon
Creators: name: Farajalla, Nadium
name: Khoury, Ricardo
name: Farajalla, Nadium
name: Khoury, Ricardo
Publisher: name: Unknown
Year: 2007
Subjects: Resource /Energy Economics and Policy

description: Agriculture is the biggest use of water in Lebanon, a relatively water-rich country in a mostly arid region. Pollution of water resources in Lebanon varies according to region but most is mainly due to sewage discharge and agricultural activities. As with intensive agricultural practices worldwide, the agricultural sector in Lebanon relies heavily on agrochemicals to protect crops and improve their yield. To ensure sustainable agricultural production, proper management of soil and water quality is required. This study aimed to identify obstacles (educational, institutional, regulatory, etc.) hindering the protection of water resources from inappropriate agricultural practices in Lebanon. First, a limited field survey was conducted to determine current farm practices with respect to the farmers’ awareness of the environmental impact of their practices, specifically agrochemical use, and the role of best management practices (BMPs). Second, a review of studies on the impact of agriculture on water resources in Lebanon and a review of current regulations and legislation aimed at controlling environmental degradation were performed. Finally, key barriers to implementing water resources protection measures (e.g. BMPs) were identified and measures to over them recommended.