cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Impact of Price Floors: A Real Options Based Experimental Approach
Creators: name: Maart, Syster Christin
name: Musshoff, Oliver
name: Maack, Moritz
name: Maart, Syster Christin
name: Musshoff, Oliver
name: Maack, Moritz
Publisher: name: Unknown
Year: 2012
Subjects: subject: Institutional and Behavioral Economics
subject: Political Economy
subject: Risk and Uncertainty
subject: Price floors
subject: investment decisions
subject: real options
subject: experimental economics

description: In order to stimulate investments, agricultural policies frequently use price floors, which guarantee a price above a certain limit. In some cases, however, a price floor does not have the desired effects. In this study, we experimentally analyse differences in the investment behaviour with respect to the presence of a price floor and compare the actual investment behaviour to normative benchmarks of the net present value and the real options approach. Furthermore, we look at treatment order and learning effects. The results show that the price floor has no significant impact on the decision behaviour of participants, whereas the effects of treatment order were statistically significant. Regarding the analysis of policy impacts, the latter result shows that the investment reluctance arising from an abolishment of a price floor is stronger than the investment stimulation arising from the introduction of a price floor. Consequently, neither the net present value nor the real options approach is appropriate to predict the investment behaviour in general. Nevertheless, we found out that the predictions of the real options approach enable an approximation of the participants’ investment behaviour if the individuals have an adequate chance to learn from personal experience.
Behaviour and performance of traders in the gum arabic supply chain in Senegal: Investigating oligopsonistic myths.
Creators: name: Mujawamariya, Gaudiose
name: Burger, Kees
name: D'Haese, Marijke F.C.
name: Mujawamariya, Gaudiose
name: Burger, Kees
name: D'Haese, Marijke F.C.
Publisher: name: Unknown
Year: 2012
Subjects: subject: Agricultural and Food Policy
subject: Industrial Organization
subject: Marketing
subject: FOS: Economics and business
subject: oligopsony
subject: double marginalisation
subject: Herfindahl index
subject: market accession
subject: market exit
subject: risk
subject: marketing margins.

description: Farmers face monopsonist/oligopsonist structures in agricultural or forest products markets because of the limited choice of traders/buyers. As a consequence, these farmers and traders alike, in successive transactions along the supply chain, may get lower prices in selling their products. This leads to a problem of double (or even multiple) marginalisation. We investigate oligopsonist tendencies in the trade of gum arabic, a non-timber forest product which is widely used as an additive in food and non-food industries. We compute traders’ shares and a corresponding Herfindahl index in primary, transport and wholesale markets of gum arabic in Senegal to analyse the market concentration; through a gllamm procedure we analyse determinants of these market shares and finally by a weighted least square regression, we analyse determinants of marketing margins of individual traders. The computed Herfindahl index was found too low to have any influence on margins and hence oligopsonist powers could not be confirmed. Instead traders’ margins depend on costs, risk and uncertainty that they face. Consequently, traders were not found exploitative; their power is derived from access to capital and market characteristics.
Pentaquarks: Status and Perspectives for Lattice Calculations
Creators: name: Sasaki, Shoichi
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The present status of pentaquark spectroscopy in lattice QCD is reviewed. This talk also includes a brief introduction of pentaquark baryons.
description: Talk presented at Lattice2004(plenary), Fermilab, June 21-26, 2004, 7 pages, 4 figures
A Data-Driven Network Model for the Emerging COVID-19 Epidemics in Wuhan, Toronto and Italy
Creators: name: Xue, Ling
name: Jing, Shuanglin
name: Miller, Joel C.
name: Sun, Wei
name: Li, Huafeng
name: Estrada-Franco, Jose Guillermo
name: Hyman, James M
name: Zhu, Huaiping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The ongoing Coronavirus Disease 2019 (COVID-19) pandemic threatens the health of humans and causes great economic losses. Predictive modelling and forecasting the epidemic trends are essential for developing countermeasures to mitigate this pandemic. We develop a network model, where each node represents an individual and the edges represent contacts between individuals where the infection can spread. The individuals are classified based on the number of contacts they have each day (their node degrees) and their infection status. The transmission network model was respectively fitted to the reported data for the COVID-19 epidemic in Wuhan (China), Toronto (Canada), and the Italian Republic using a Markov Chain Monte Carlo (MCMC) optimization algorithm. Our model fits all three regions well with narrow confidence intervals and could be adapted to simulate other megacities or regions. The model projections on the role of containment strategies can help inform public health authorities to plan control measures.
Doppler effect as a tool for ultrashort electric field reconstruction
Creators: name: Béjot, P.
name: Szmygel, E.
name: Dubrouil, A.
name: Billard, F.
name: Lavorel, B.
name: Faucher, O.
name: Hertz, E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Technological advances in femtosecond laser sources call for the development of increasingly refined characterization tools implying to enrich the existing panel of operable nonlinear interactions. The present paper describes a novel characterization method based on spectral-shearing interferometry which exploits the non-standard rotational Doppler effect for producing the frequency shear. This original approach, called DEER "Doppler Effect for Electric field Reconstruction", provides a spectral-shearing in the absence of frequency conversion and features multiple benefits as for instance the ability of operation in the ultraviolet spectral range or the characterization of ultra-broadband laser pulses.
description: 7 pages, 3 figures
Custo do cadeia produtiva do frango: parceria entre cooperativa e pequenos produtores familiares no Estado de Santa Catarina
Creators: name: Talamini, Dirceu Duarte
name: Martins, Franco Muller
name: Oliveira, Antonio Jorge
name: Talamini, Dirceu Duarte
name: Martins, Franco Muller
name: Oliveira, Antonio Jorge
Publisher: name: Unknown
Year: 2006
Subjects: Farm Management
Livestock Production/Industries

description: O trabalho teve como objetivo determinar o custo de todos os elos da cadeia de produção do frango inteiro congelado do corredor Oeste do Estado de Santa Catarina ao porto de Itajaí no mesmo estado. A etapa inicial, ou seja, a produção do frango vivo é realizada em parceria entre pequenos produtores familiares e uma cooperativa que coordena todas as ações. A etapa de transporte dos animais vivos até a indústria é terceirizada, assim como a do transporte do frango congelado até o porto. A etapa de abate e preocessamento das aves é feita em planta da cooperativa. Observou-se a grande participação do custo do frango vivo, seguido do custo do abate e processamento no custo do produto pronto e que a cadeia apresenta um estrutura de custos competitiva tanto em relação a outras regiões brasileiras como em relação a outros países produtores. Os indicadores técnicos, por outro lado, indicam uma adequada governança e coordenação da cadeia e que a especificidade dos ativos estimula o compromisso dos agentes econômicos no uso de novas tecnologias de produção e de gestão visando manter a atividade competitiva no longo prazo.
Evaluating the Magnetic Field Strength in Molecular Clouds
Creators: name: Houde, Martin
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss an extension to the Chandrasekhar-Fermi method for the evaluation of the mean magnetic field strength in molecular clouds to cases where the spatial orientation of the field is known. We apply the results to M17, using previously published data.
description: 10 pages, 1 figure, accepted for publication in the ApJ Letters
The stellar velocity distribution function in the Milky Way galaxy
Creators: name: Anguiano, Borja
name: Majewski, Steven R.
name: Hayes, Chris R.
name: Prieto, Carlos Allende
name: Cheng, Xinlun
name: Bidin, Christian Moni
name: Beaton, Rachael L.
name: Beers, Timothy C.
name: Minniti, Dante
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The stellar velocity distribution function (DF) in the solar vicinity is re-examined using data from the SDSS APOGEE survey's DR16 and \emph{Gaia} DR2. By exploiting APOGEE's ability to chemically discriminate with great reliability the thin disk, thick disk and (accreted) halo populations, we can, for the first time, derive the three-dimensional velocity DFs for these chemically-separated populations. We employ this smaller, but more data-rich APOGEE+{\it Gaia} sample to build a \emph{data-driven model} of the local stellar population velocity DFs, and use these as basis vectors for assessing the relative density proportions of these populations over 5 $
description: 15 pages, 12 figures, accepted for publication in ApJ
DESENVOLVIMENTO LOCAL SUSTENTÁVEL NA ZONA DA MATA-PE: ASPECTOS ESTRUTURANTES DO PROMATA NO MUNICÍPIO DE PAUDALHO
Creators: name: Neto, Eurico Araujo Noblat
name: Albuquerque, Jose De Lima
name: Silva, Ana Maira Navaes Da
name: Neto, Eurico Araujo Noblat
name: Albuquerque, Jose De Lima
name: Silva, Ana Maira Navaes Da
Publisher: name: Unknown
Year: 2006
Subjects: Community/Rural/Urban Development
Resource /Energy Economics and Policy

description: Este trabalho procura analisar em que medida os instrumentos de políticas públicas, neste caso específico, o Programa de Apoio ao Desenvolvimento Sustentável da Zona da Mata de Pernambuco (PROMATA), criado a partir de 2001, com apoio do Banco Interamericano de Desenvolvimento (BID), contribuem como instrumento de desenvolvimento local em economias periféricas, neste caso no município de Paudalho. Observou-se que, apesar das amplas estratégias englobadas pelo PROMATA, pouco se obteve em termos de resultados concretos para o desenvolvimento do município. Os aspectos relativos ao diagnóstico das potencialidades e prioridades para o desenvolvimento local não foram alcançados e muito menos combatidos pelo programa, além do que, restando muito pouco tempo para a conclusão do programa, este não resultou em projetos que efetivamente resultassem em melhoria de qualidade de vida para os habitantes do município.
A uniform result for the dimension of fractional Brownian motion level sets
Creators: name: Daw, Lara
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: Let $B =\{ B_t \, : \, t \geq 0 \}$ be a real-valued fractional Brownian motion of index $H \in (0,1)$. We prove that the macroscopic Hausdorff dimension of the level sets $\mathcal{L}_x = \left\{ t \in \mathbb{R}_+ \, : \, B_t=x \right\}$ is, with probability one, equal to $1-H$ for all $x\in\mathbb{R}$.
பாரதிதாசனின் உணர்ச்சிநிலைகள்
Creators: name: Devarkaivalyam, Ashok
Publisher: name: figshare
Year: 2020
Subjects: subject: 200315 Indian Languages
subject: FOS: Languages and literature

description: மனித இனம் தன் கருத்துக்களை மொழியாகிய வழியாக வெளிப்படுத்தி சமூகத்தை நடத்தி வருகிறது. ஒருவரின் உணர்வுகளை வெளிப்படுத்துவதில் மொழி முதன்மையானது. உணர்வை வெளிப்படுத்துவதில் மொழியில் கவிதைகளின் பங்கு அளப்பரியது. இருபதாம் நூற்றாண்டின் இணையற்ற தமிழ் கவிஞர்களின் குறிப்பிடத்தக்கவர் பாவேந்தர் பாரதிதாசன் பாவேந்தர். பாரதிதாசன் படைப்புகளில் உணர்ச்சிமயமான போக்குவதாக அமைகின்றது. தமிழ் உணர்வை வெளிப்படுத்துவதில் பாவேந்தருக்கு நிகர; பாவேந்தரேயாவார;. பாவேந்தர் திருமண முறையில் உள்ள குறைபாடுகளை களைதல் உழைப்பாளிகளின் மீதான அக்கரை மான உணர்ச்சி ஆகியவற்றின் அடிப்படையில் உணர்ச்சி பொங்க கவிதை இயற்றி இந்த சமூகத்தைப் பல்வேறு உணர்வு நிலைக்கு உள்ளாகிறார்.
A heavy Higgs boson from flavor and electroweak symmetry breaking unification
Creators: name: Bazzocchi, Federica
name: Fabbrichesi, Marco
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a unified picture of flavor and electroweak symmetry breaking based on a nonlinear sigma model spontaneously broken at the TeV scale. Flavor and Higgs bosons arise as pseudo-Goldstone modes. Explicit collective symmetry breaking yields stable vacuum expectation values and masses protected at one loop by the little-Higgs mechanism. The coupling to the fermions generates well-definite mass textures--according to a U(1) global flavor symmetry--that correctly reproduce the mass hierarchies and mixings of quarks and leptons. The model is more constrained than usual little-Higgs models because of bounds on weak and flavor physics. The main experimental signatures testable at the LHC are a rather large mass m_{h^0} = 317\pm 80 GeV for the (lightest) Higgs boson and a characteristic spectrum of new bosons and fermions at the TeV scale.
description: 5 pages
Integrating climate change into forest planning : a spatial and temporal analysis of landscape vulnerability
Creators: name: Nitschke, Craig Robert
Publisher: name: University of British Columbia
Year: 2010

description: The achievement of sustainable forest management requires the incorporation of risk and uncertainty into long-term planning. Climatic change is one stressor that will have significant impact on natural disturbances, ecosystems and biodiversity, particularly on landscapes influenced by forest management. Understanding where vulnerabilities lie and when climatic thresholds are reached are important areas of knowledge that must be used to manage the risks associated directly or indirectly with climatic change. The vulnerability of landscapes to natural disturbances, the resilience of ecosystems and distribution of biodiversity are all important components that need to be considered when undertaking forest planning. Through the use of modelling the vulnerability of a 145,000 ha landscape in the south-central interior of British Columbia was used as case study to assess the vulnerability of fire potential, fire regimes, ecosystem resilience and biodiversity to climatic change. The results from the analysis of fire potential identified a 30% increase in fire season length and a 95% increase in fire severity by 2085. A statistically significant shift in fire behaviour was also detected by 2070 with crown fires predicted to be more common. Climatic change was also found to significantly increase mean fire size by 2025 and decrease the mean return interval. By 2085, 95% of the landscape could burn every 50 years or less compared to the 34% currently classified. Ecosystem resilience was modelled to be affected to varying degrees with a shift in many species to higher elevation and/or to non-water deficit sites between 2025 and 2085. Six species were predicted to be at extreme risk and four others at high risk. An analysis of bark beetle risk identified 38.7% of the study area is currently at some degree of risk to attack. An analysis of biodiversity identified 19 indicator species that could be used to monitor management actions with a biodiversity management area that covers 66% of the landscape. These analyses were used as a foundation to guide forest zoning allocation, using the triad zoning framework, and for developing a "Climate-smart" management paradigm to be used for managing the landscape after allocation.
Speed of sound and quark confinement inside neutron stars
Creators: name: Marczenko, Michał
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Several observations of high-mass neutron stars (NSs), as well as the first historic detection of the binary neutron star merger GW170817, have delivered stringent constraints on the equation of state (EoS) of cold and dense matter. Recent studies suggest that, in order to simultaneously accommodate a $2M_\odot$ NS and the upper limit on the compactness, the pressure has to swiftly increase with density and the corresponding speed of sound likely exceeds the conformal limit. In this work, we employ a unified description of hadron-quark matter, the hybrid quark-meson-nucleon (QMN) model, to investigate the EoS under NS conditions. We show that the dynamical confining mechanism of the model plays an important role in explaining the observed properties of NSs.
description: submitted to epj st. arXiv admin note: substantial text overlap with arXiv:2004.09566
Exploring the characteristics of innovation alliances of Dutch Biotechnology SMEs and their policy implications
Creators: name: Garbade, Philipp J.P.
name: Omta, S.W.F. (Onno)
name: Fortuin, Frances T.J.M.
name: Garbade, Philipp J.P.
name: Omta, S.W.F. (Onno)
name: Fortuin, Frances T.J.M.
Publisher: name: Unknown
Year: 2013
Subjects: subject: Agribusiness
subject: Industrial Organization
subject: Research and Development/Tech Change/Emerging Technologies
subject: knowledge transfer
subject: human resources exchange
subject: biotechnology alliances

description: Policy makers are becoming increasingly aware of the fact that R&D intensive SMEs play a pivotal role in providing sustainable economic growth by maintaining a high rate of innovation. To compensate for their financial vulnerability, these SMEs increasingly conduct innovation in alliances. This paper aims to explore the impact of different alliance characteristics on the performance of Dutch biotechnology SMEs. The conceptual model was tested using a sample of 18 biotech SMEs reporting about 40 alliances. The main findings indicate that alliance performance is positively related to the level of complementarity, the cognitive distance and tacit knowledge transfer by the human resources exchanges. Policy makers are recommended to support innovation alliances by providing the infrastructure in which alliances can flourish, e.g. through stimulating the foundation of cluster organizations that can function as innovation brokers. These cluster organizations can provide network formation, demand articulation, internationalization and innovation process support to their member companies and can act as a go-between among alliance partners. As part of the innovation process support activities, they can organize special workshops for biotech SMEs on how to successfully behave in an innovation alliance.
Ectomycorrhizal communities of Douglas-fir and paper birch along a gradient of stand age following clearcutting and wildfire in the Interior Cedar-Hemlock zone, southern British Columbia
Creators: name: Twieg, Brendan David
Publisher: name: University of British Columbia
Year: 2010

description: Ectomycorrhizal (ECM) communities of Douglas-fir and paper birch were characterized in 5-, 26-, 65, and 100-year-old stands using ECM root tip morphology and ITS region DNA sequences. Stands disturbed by wildfire (all age classes) and clearcutting (two youngest age classes) were studied (4 replicates per stand type) in the Interior Cedar-Hemlock forests of southern British Columbia. ECM community species richness on Douglas-fir differed with stand age, being three times higher in 65- and 100-yr-old stands than 5-yr-old stands; 26-yr-old stands were intermediate. In the 5-yr-old stands, the ECM community of paper birch had ~70% higher species richness than Douglas-fir. Roots of sprouting paper birch stumps may support mycorrhizae or inocula that persist through disturbance. Overall ECM diversity increased substantially from 5- to 26-yr-old stands, but changed little with further stand age increase. ECM community composition and structure shifted from 5- to 26-yr-old stands and continued to change from 26- to 65-yr-old stands, including increases in Russula and Piloderma relative abundances. Similar ECM communities occurred on 65- and 100-yr-old stands. Cortinurius and Hebeloma were nearly absent in 5-yr-old stands and peaked in relative abundance in 26-yr-old stands. Generally, patterns in relative abundance of fungal taxa with stand age paralleled those in frequency. Host-specific ECM fungi were most dominant in the youngest stands, particularly Rhizopogon vinicolor-type on Douglas-fir and Lacturius pubescens on paper birch. Host-generalists were more abundant on paper birch than Douglas-fir at younger ages, suggesting that paper birch may be important in the establishment of these fungi on Douglas-fir. Paper birch also had an important positive influence on ECM fungal diversity in 5-yr-old stands, which should be considered in forest management. There was no difference in ECM diversity between clearcut and wildfire origin sites, although community structure differed slightly between these disturbances in 5-yr-old stands. Within the range of ages studied, it appears that the ECM fungal community changed little after 65 years following disturbance. Available P was correlated with abundance of two dominant taxa, but available N and P, mineralizable N, and organic P were not related to ECM diversity or community structure.
Laboratory Physics and Cosmology
Creators: name: Alfonso-Faus, Antonio
Publisher: name: arXiv
Year: 2004
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: We find five fundamental reasons demanding that any gravitational mass m, and the speed of light c, vary with cosmological time such that mc remains constant. This is required by the universal condition of conservation of momentum in a Universe with spatial homogeneity. We prove that this is consistent with Einstein's Theory of General Relativity. We call this effect a "MASS BOOM". At the LAB system no such time variations can be detected, unless we make comparisons with cosmological observations. We have to stress that the physical conditions implied by a time varying mass, together with a time varying speed of light, preserving the constancy of momentum, are compatible with Einstein's field equations. We then integrate his cosmological equations and find the solution for the cosmological scale factor a(t) proportional to the square of time, implying an apparent accelerated expansion for the Universe, as seen from the LAB frame. This is the interpretation given to recent observations obtained from the Supernova Type Ia. This determination of the scale factor a(t) is based upon a LAB interpretation and therefore is an apparent effect. On the other hand we note that the product ct being a constant determines the real Universe as a static one, of constant size. The observed red shift at the LAB system is due to a real shrinkage of the quantum world, due to the decrease in size of the quantum particles determined by a decreasing Planck's "constant".
description: Accepted for publication in Physics Essays 2004
Chemical compositions of Four B-type Supergiants in the SMC Wing
Creators: name: Lee, J. -K.
name: Rolleston, W. R. J.
name: Dufton, P. L.
name: Ryan, R. S. I.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: High-resolution UCLES/AAT spectra of four B-type supergiants in the SMC South East Wing have been analysed using non-LTE model atmosphere techniques to determine their atmospheric parameters and chemical compositions. The principle aim of this analysis was to determine whether the very low metal abundances ($-$1.1 dex compared with Galactic value) previously found in the Magellanic Inter Cloud region (ICR) were also present in SMC Wing. The chemical compositions of the four targets are similar to those found in other SMC objects and appear to be incompatible with those deduced previously for the ICR. Given the close proximity of the Wing to the ICR, this is difficult to understand and some possible explanations are briefly discussed.
description: 11 pages, 2 figues, A&A accepted
Novel oseltamivir-resistant mutations distant from the active site of influenza B neuraminidase
Creators: name: Kato, Yusuke
name: Takahashi, Kazuhiro
name: Fuyu Ito
name: Suzuki, Shoichi
name: Fukui, Kiyoshi
name: Mimaki, Masakazu
name: Suzuki, Kazuo
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biophysics
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Evolutionary Biology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology
subject: Computational Biology

description: We performed a neuraminidase sequence analysis of thirty-two pediatric patients with influenza B who visited Teikyo University Hospital from January 2016 to March 2017, and found oseltamivir-resistant samples belonging to the Yamagata and Victoria lineages. Comparison with the neuraminidase sequence of oseltamivir-susceptible B/Brisbane/60/2008 revealed 5 common amino acid substitutions in many of these samples. According to the binding free energy calculation, the N340D and E358K substitutions reduced the affinity of oseltamivir to neuraminidase. Unexpectedly, these substitutions were located distant from the oseltamivir-binding site in neuraminidase. According to the molecular dynamics simulations, the N340D substitution rearranged complicated hydrogen bond networks in an extensive surface region of neuraminidase. The E358K substitution extensively altered the electrostatic potential map of the overall neuraminidase structure. Through these novel mechanisms, the N340D and E358K substitutions indirectly influenced the affinity reduction. These results may be useful for designing drugs for the treatment of oseltamivir-resistant virus infections. Communicated by Ramaswamy H. Sarma
Gauge Functions in Classical Mechanics: From Undriven to Driven Dynamical Systems
Creators: name: Musielak, Z. E.
name: Vestal, L. C.
name: Tran, B. D.
name: Watson, T. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Novel gauge functions are introduced to non-relativistic classical mechanics and used to define forces. The obtained results show that the gauge functions directly affect the energy function and that they allow converting an undriven physical system into a driven one. This is a novel phenomenon in dynamics that resembles the role of gauges in quantum field theories.
description: 11 pages
EMPREGO RURAL NA FRUTICULTURA PARAIBANA NO PERÍODO 1990-2003
Creators: name: Souza, Ana Paula Lopes De
name: Cavalcanti, Guilherme De Albuquerque
name: Fonseca, Marcia Batista
name: Souza, Ana Paula Lopes De
name: Cavalcanti, Guilherme De Albuquerque
name: Fonseca, Marcia Batista
Publisher: name: Unknown
Year: 2006
Subjects: Community/Rural/Urban Development
Labor and Human Capital

description: A fruticultura movimenta no Brasil um PIB de US$ 1,5 bilhão, ocupando uma área de 2,6 milhões de hectares, equivalente a 5% da área cultivada, onde são gerados 4 milhões de empregos e no estado da Paraíba caracteriza-se como uma importante alternativa na geração de emprego e renda. A literatura existente sobre a fruticultura no estado revela que há poucos estudos sobre o emprego da mão-de-obra na produção de frutas, principalmente no que diz respeito a informações estatísticas que revelem a evolução do emprego gerado pela fruticultura da Paraíba. Desta forma, a preocupação desse trabalho de pesquisa é contribuir para o preenchimento desta lacuna através da discrição da situação geral do emprego em algumas importantes fruteiras cultivadas internamente. Serão utilizadas como referencial de estudo as frutas de maior importância para a economia paraibana entre 1990 e 2003, quais sejam: abacaxi, banana, coco-da-baía, laranja, mamão e manga. O objetivo deste estudo é estimar o número de empregos gerado na produção de frutas na Paraíba, destacando sua evolução recente e a justificativa para este estudo encontra-se no fato de que este esforço de pesquisa contribui para conhecer aspectos do emprego na fruticultura do Estado. A estimação é feita com base em dados secundários junto ao IBGE e ao BNB. O marco teórico tem como referencial de estudo teorias que versem sobre o mercado de trabalho. Os resultados indicam que dentre as frutas estudadas a maior demanda de empregos/ano encontra-se nas lavouras de banana, coco-da-baía e abacaxi, respectivamente, em função de possuírem uma área colhida relativamente elevada. Percebe-se ainda que fatores sazonais, como a seca e institucionais, como a cobrança do ICMS provocam redução no nível de emprego. Conclui-se que a fruticultura paraibana foi responsável, em média, entre 1990-2003, pela geração de 66.099 empregos/ano, revelandose como uma atividade de grande importância social e econômica para o Estado.
Flow-induced voltage and current generation in carbon nanotubes
Creators: name: Ghosh, S.
name: Sood, A. K.
name: Ramaswamy, S.
name: Kumar, N.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: New experimental results, and a plausible theoretical understanding thereof, are presented for the flow-induced currents and voltages observed in single-walled carbon nanotube samples. In our experiments, the electrical response was found to be strongly sublinear -- nearly logarithmic -- in the flow speed over a wide range, and its direction could be controlled by an electrochemical biasing of the nanotubes. These experimental findings are inconsistent with the conventional idea of a streaming potential as the efficient cause. Here we present a new, physically appealing, Langevin-equation based treatment of the nanotube charge carriers, assumed to be moving under coulombic forcing by the correlated ionic fluctuations, advected by the liquid in flow. The resulting 'Doppler-shifted' force-force correlation, as seen by the charge carriers drifting in the nanotube, is shown to give a strongly sublinear response, broadly in agreement with experiments.
description: 11 pages including 3 figures. To appear in Phys. Rev B (2004)
The Cayley isomorphism property for the group $C^5_2\times C_p$
Creators: name: Ryabov, Grigory
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 05C25, 05C60, 20B25

description: A finite group $G$ is called a DCI-group if two Cayley digraphs over $G$ are isomorphic if and only if their connection sets are conjugate by a group automorphism. We prove that the group $C_2^5\times C_p$, where $p$ is a prime, is a DCI-group if and only if $p\neq 2$. Together with the previously obtained results, this implies that a group $G$ of order $32p$, where $p$ is a prime, is a DCI-group if and only if $p\neq 2$ and $G\cong C_2^5\times C_p$.
description: 19 pages. arXiv admin note: text overlap with arXiv:2003.08118, arXiv:1912.08835
A REGRA ÓTIMA DE ARMAZENAMENTO DE ARROZ NO BRASIL ATRAVÉS DE UM MODELO DINÂMICO DE EXPECTATIVAS RACIONAIS
Creators: name: Bragagnolo, Cassiano
name: Guimaraes, Vania Di Addario
name: Bragagnolo, Cassiano
name: Guimaraes, Vania Di Addario
Publisher: name: Unknown
Year: 2006
Subjects: Crop Production/Industries

description: Este trabalho pretende aplicar um modelo econômico dinâmico de expectativas racionais para armazenamento de arroz no Brasil com o intuito de modelar a decisão de estocagem. Estas quantidades de estoque maximizam os efeitos de bem-estar oriundos da introdução da estocagem como uma atividade econômica competitiva em um mercado com oferta estocástica, onde todos os indivíduos são maximizadores de lucro com expectativas racionais. Os impactos dependem, principalmente, da informação disponível ao produtor antes do armazenamento ser introduzido, da elasticidade da oferta de área, da especificação da curva de demanda, dos custos de estocagem, da taxa de juros considerada e do custo de estocagem. Estas funções e valores foram utilizados para a estimação de um modelo dinâmico de expectativas racionais, através de programação dinâmica estocástica, aproximando uma função de preço esperado e área plantada em função do estoque inicial, fazendo uso de polinômio de quarto grau no estoque, onde se encontrou uma disponibilidade crítica, a partir da qual, ocorrerá armazenamento como uma atividade econômica. Em seguida procedeu-se a estimação de simulações de longo-prazo com o intuito de avaliar os impactos de altos e baixos estoques iniciais no mercado. Os resultados demonstraram que estes impactos podem ser percebidos por cerca de 3 ou 4 safras.
DETERMINAÇÃO DA BASE DO MILHO EM DIFERENTES MUNICÍPIOS DO BRASIL
Creators: name: Dias, Vitor Caminha Faustino
name: Nishioka, Nelson Norio
name: Marques, Pedro Valentim
name: Martines-Filho, Joao Gomes
name: Neto, Leonardo Francisco Figueiredo
name: Dias, Vitor Caminha Faustino
name: Nishioka, Nelson Norio
name: Marques, Pedro Valentim
name: Martines-Filho, Joao Gomes
name: Neto, Leonardo Francisco Figueiredo
Publisher: name: Unknown
Year: 2006
Subjects: Crop Production/Industries

description: A importância do cálculo da base deve-se ao fato de que em operações realizadas em Mercados Futuros, o preço negociado não é necessariamente igual ao preço físico onde o hedger encontra-se. Na realidade, essa igualdade dificilmente acontece. Assim, como os preços dos produtos diferem em cada região, o cálculo da base para cada uma delas torna-se um instrumento muito útil ao negociar um contrato futuro. O objetivo do presente é de fornecer aos agentes de mercados futuros não só os valores da base, mas também enfatizar sua importância e as vantagens de seu prévio conhecimento quando se opera em mercados futuros. Sendo o milho o principal componente da ração utilizada na alimentação de frangos e de suínos e dada a importância dessas atividades no agronegócio, foram escolhidos 04 municípios, pelos motivos adiante descritos: a)Toledo (PR) e Chapecó (SC), onde as atividades de suinocultura e de avicultura são tradicionalmente desenvolvidas. b) Rio Verde (GO), município em que há grande expansão dessas atividades, principalmente após a implantação do projeto Buriti Perdigão. c) Lucas do Rio Verde (MT), região produtora de milho, onde se percebe que essas atividades (suinocultura e avicultura) ainda encontram-se pouco desenvolvidas. Os preços físicos de cada região foram obtidos através do Sistema Corporativo do Banco do Brasil S/A – Aplicativo Risco Técnico Agrícola (RTA) e os preços futuros utilizados para o cálculo são originários da BMF. O período analisado é relativo aos contratos futuros com vencimento entre 1997 e 2004. Dois Métodos foram utilizados na análise dos dados: a) Obtenção de base para seis meses anteriores aos vencimentos; b) Base relativa ao vencimento mais próximo de cada mês. Os resultados obtidos no trabalho evidenciam a importância do cálculo da base na tomada de decisão de hedgers no mercado do milho, tendo assim, a possibilidade de diminuir o risco inerente à comercialização de commodities agrícola.
Spatial Entity Resolution between Restaurant Locations and Transportation Destinations in Southeast Asia
Creators: name: Gao, Emily
name: Widdows, Dominic
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: As a tech company, Grab has expanded from transportation to food delivery, aiming to serve Southeast Asia with hyperlocalized applications. Information about places as transportation destinations can help to improve our knowledge about places as restaurants, so long as the spatial entity resolution problem between these datasets can be solved. In this project, we attempted to recognize identical place entities from databases of Points-of-Interest (POI) and GrabFood restaurants, using their spatial and textual attributes, i.e., latitude, longitude, place name, and street address.
 Distance metrics were calculated for these attributes and fed to tree-based classifiers. POI-restaurant matching was conducted separately for Singapore, Philippines, Indonesia, and Malaysia. Experimental estimates demonstrate that a matching POI can be found for over 35% of restaurants in these countries. As part of these estimates, test datasets were manually created, and RandomForest, AdaBoost, Gradient Boosting, and XGBoost perform well, with most accuracy, precision, and recall scores close to or higher than 90% for matched vs. unmatched classification. To the authors' knowledge, there are no previous published scientific papers devoted to matching of spatial entities for the Southeast Asia region.
The Inverse Problem for Simple Liquid Metals a Study Case on Liquid Aluminum at Melting Point
Creators: name: El-Daher, Moustafa Sayem
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In an attempt to test the possibility of solving the inverse problem for liquid metals i.e. obtaining the effective pair potential from the experimental structure factor, we solve the modified Hypernetted-Chain Integral equation for liquid aluminum at melting temperature to obtain the effective pair potential starting from the experimental structure factor and compare it with the potential obtained from theoretical considerations. Then we use the potential obtained by solving the inverse problem in Monte Carlo simulation to test it, and the calculated structure factor of the liquid aluminum is compared with experiment. We show that the solution of the inverse problem in such cases gives reasonable quantitative results, and reproduces the general features of the pair potential and the results for the structure factor are not far from the experimental measurements.
Pipes, pennies, and politics : an exploration of water conservation in the Greater Vancouver area
Creators: name: Uitto, Taina
Publisher: name: University of British Columbia
Year: 2010

description: This thesis examines municipal water conservation activities in the Greater Vancouver area. First, I conducted a literature review to provide context for water management within the region, build a case for water conservation, and provide examples of barriers to and drivers of water conservation. Because limited studies exist that have sought to elicit the perceptions of water conservation administrators, I interviewed personnel involved with planning and implementing water conservation activities at the Greater Vancouver Regional District and in the region's municipalities. The results provide an indication of the current circumstances and potential for water conservation in the region. Interviewees identified perceived reasons for water conservation generally, and in relation to specific water conservation initiatives. They also identified positive drivers of change, and a number of obstacles that hinder the advancement of initiatives. In evaluating the potential for water conservation, I infer that there is room for improvement if a change to the status quo is desired. Although interviewees identified a comprehensive array of reasons that necessitate water conservation, when it comes to reasons for specific initiatives, interviewees were principally motivated by practical, political, and financial benefits; environmental and associated social benefits were largely unmentioned, and in some cases, dismissed as insignificant. Only a few interviewees spoke of more holistic reasons. Based on these results, there is an apparent discrepancy between what interviewees think (and practise) and what is declared by literature as the full case for water conservation. Furthermore, interviewees did not live up to the expectations set by the local literature that environmental and social considerations have significance to decision-making when it comes to water conservation. Although interviewees placed much accountability to the public and politicians, overall, the full case for water conservation has not been articulated by water conservation administrators themselves; I infer this to be a shortcoming of the current circumstances. Furthermore, there is a lack of water conservation advocates who view water management from a more holistic perspective; the results indicate the prevalence of perspectives more associated with supply and demand management. In turning the given barriers into drivers, positive opportunities for change can be found.
Microlensing Optical Depth towards the Galactic Bulge Using Clump Giants from the MACHO Survey
Creators: name: Popowski, P.
name: Griest, K.
name: Thomas, C. L.
name: Cook, K. H.
name: Bennett, D. P.
name: Becker, A. C.
name: Alves, D. R.
name: Minniti, D.
name: Drake, A. J.
name: Alcock, C.
name: Allsman, R. A.
name: Axelrod, T. S.
name: Freeman, K. C.
name: Geha, M.
name: Lehner, M. J.
name: Marshall, S. L.
name: Nelson, C. A.
name: Peterson, B. A.
name: Quinn, P. J.
name: Stubbs, C. W.
name: Sutherland, W.
name: Vandehei, T.
name: Welch, D.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using 7 years of MACHO survey data, we present a new determination of the optical depth to microlensing towards the Galactic bulge. We select the sample of 62 microlensing events (60 unique) on clump giant sources and perform a detailed efficiency analysis. We use only the clump giant sources because these are bright bulge stars and are not as strongly affected by blending as other events. Using a subsample of 42 clump events concentrated in just 4.5 square degrees, we find tau = 2.17^{+0.47}_{-0.38} x 10^{-6} at (l,b) = (1.50, -2.68), somewhat smaller than found in most previous MACHO studies, but in excellent agreement with recent theoretical predictions. We also present the optical depth in each of the 19 fields in which we detected events, and find limits on optical depth for fields with no events. The errors in optical depth in individual fields are dominated by Poisson noise. We measure optical depth gradients (1.06 +/- 0.71) x 10^{-6} deg^{-1} and (0.29 +/- 0.43) x 10^{-6} deg^{-1} in the galactic latitude b and longitude l directions, respectively. Finally, we discuss the possibility of anomalous duration distribution of events in the field 104 centered on (l,b) = (3.11, -3.01) as well as investigate spatial clustering of events in all fields.
description: 42 pages, 15 figures (6 of them in color), 12 tables; results unchanged, discussion of blending strengthened including addition of new appendix; to be published in ApJ, Vol. 630, Sept. 10, 2005 issue
Reference design for closed loop system optimization
Creators: name: Balula, Samuel
name: Liniger, Alex
name: Rupenyan, Alisa
name: Lygeros, John
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: An optimization-based method for improving the productivity of precision machine tools is proposed, where the reference path is computed in local coordinates, and information about the machine tool performance is learned from experimental data. The optimization yields a modified reference that is tracked by the existing low-level controller. The method is tested in simulation for a biaxial positioning system. The positioning system is modelled as double integrator, and the controller characteristic is modelled from experimental data using a least-squares fit. Simulation results show that the method is effective in designing optimal references even for challenging geometries such as sharp corners. The application of this procedure allows the retrofit of the control of existing machines with minimal overhead, by providing a modified reference file to track.
description: to be published in European Control Conference 2020 proceedings
On the strong-coupling effects in jet bremsstrahlung in the heavy flavor decays
Creators: name: Uraltsev, Nikolai
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We address the strong-coupling regime effects in the light-like quark jets where the radiated gluons are hard but highly collinear. These may lead to additional contributions in the invariant mass (or recoil energy) spectra, on top of the Fermi motion of the initial heavy quark in decays like b->s+γ. It is shown that the integer moments are nevertheless free from such effects; perturbation theory corrections for the moments are driven by α_s in the small coupling regime. They are modified nonperturbatively by the soft modes but not by the collinear modes.
description: 9 pages, LaTeX, one figure
Constraints on Stupendously Large Black Holes
Creators: name: Carr, Bernard
name: Kuhnel, Florian
name: Visinelli, Luca
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider the observational constraints on stupendously large black holes (SLABs) in the mass range $M \gtrsim 10^{11}\,M_{\odot}$. These have attracted little attention hitherto and we are aware of no published constraints on a SLAB population in the range $(10^{12}$ - $10^{18})\,M_{\odot}$. However, there is already evidence for black holes of up to nearly $10^{11}\,M_{\odot}$ in galactic nuclei, so it is conceivable that SLABs exist and they may even have been seeded by primordial black holes. We focus on limits associated with (i) dynamical and lensing effects, (ii) the generation of background radiation through the accretion of gas during the pregalactic epoch, and (iii) the gamma-ray emission from the annihilation of the halo of weakly interacting massive particles (WIMPs) expected to form around each SLAB if these provide the dark matter. Finally, we comment on the constraints on the mass of ultra-light bosons from future measurements of the mass and spin of SLABs.
description: v2: major revision
First Passage Properties of the Erdos-Renyi Random Graph
Creators: name: Sood, V.
name: Redner, S.
name: ben-Avraham, D.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study the mean time for a random walk to traverse between two arbitrary sites of the Erdos-Renyi random graph. We develop an effective medium approximation that predicts that the mean first-passage time between pairs of nodes, as well as all moments of this first-passage time, are insensitive to the fraction p of occupied links. This prediction qualitatively agrees with numerical simulations away from the percolation threshold. Near the percolation threshold, the statistically meaningful quantity is the mean transit rate, namely, the inverse of the first-passage time. This rate varies non-monotonically with p near the percolation transition. Much of this behavior can be understood by simple heuristic arguments.
description: 10 pages, 9 figures, 2-column revtex4 format