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Application of formal languages in polynomial transformations of instances between NP-complete problems

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第8期14卷 623-633页

作者： Jorge A. RUIZ-VANOYE Joaquín PREZ-ortega Rodolfo A. PAZOS RANGEl Ocotlán DíAZ-PARRA Héctor J. FRAIRE-HUACUJA Juan FRAUSTO-SOlíS Gerardo reyes-SAlGADO laura CRUZ-reyes DACI Universidad Autónoma del Carmen Computer Science Centro Nacional de Investigación y Desarrollo Tecnológico Systems and Computer Science Instituto Tecnológico de Ciudad Madero Informatics Universidad Politécnica del Estado de Morelos Computer Science Instituto Tecnológico de Cuautla

We propose the usage of formal languages for expressing instances of NP-complete problems for their application in polynomial transformations. The proposed approach, which consists of using formal language theory for polynomial transformations, is more robust, more practical, and faster to apply to real problems than the theory of polynomial transformations. In this paper we propose a methodology for transforming instances between NP-complete problems, which differs from Garey and Johnson's. Unlike most transformations which are used for proving that a problem is NP-complete based on the NP-completeness of another problem, the proposed approach is intended for extrapolating some known characteristics, phenomena, or behaviors from a problem A to another problem B. This extrapolation could be useful for predicting the performance of an algorithm for solving B based on its known performance for problem A, or for taking an algorithm that solves A and adapting it to solve B.

关键词： Formal languages Polynomial transformations NP-completeness

Context-dependent insect predation pressure on an avian ectoparasite

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Insect Science 2023年第6期30卷 1784-1797页

作者： Angela Salido Jesús Veiga Joaquín luis reyes-lópez Francisco Valera Department of Botany Ecology and Plant PhysiologyUniversity of CórdobaCórdobaSpain Departamento de Ecología Funcional y Evolutiva Estación Experimental de ZonasÁridas(EEZA-CSIC)AlmeríaSpain Department of Parasitology University of GranadaGranadaSpain MEMEG Department of BiologyLund UniversityLundSweden

Context dependence arises when ecological relationships vary with the conditions under which they are observed. Context dependence of interactions involving parasites is poorly known, even if it is key to understanding host–parasite relationships and food web dynamics. This paper investigates to which extent predation pressure on an avian ectoparasite (Carnus hemapterus) is context-dependent. Based on a predator-exclusion experiment, predation pressure on C. hemapterus pupae in the host's nest for 3 years, and its variation between habitat types are quantified. Variation in precipitation and normalized difference vegetation index (NDVI) is also explored as a likely cause of context dependency. We hypothesize that predation pressure should fluctuate with such surrogates of food availability, so that inter-annual and intra-annual differences may emerge. The number of nests with significant reduction of pupae varied widely among years ranging from 24% to 75%. However, average pupae reduction in nests where a significant reduction occurred did not vary between years. No differences in predation rates between habitat types were detected. Precipitation and NDVI varied widely between years and NDVI was consistently lower around nests on cliffs than around nests on trees and farmhouses. Parallels were found between variation in predation pressure and precipitation/NDVI at a wide scale (highest predation the driest year, and much lower the 2 rainier ones), but not at the nest scale. This paper shows clear context-dependent insect predation pressure on an ectoparasite under natural conditions, and that such interaction changes in signs rather than magnitude between years. The causes for these variations require longer-term studies and/or well-designed, large-scale experiments.

关键词： ants arid areas Carnus hemapterus consumer-resource interaction ecosys-tem productivity predator-parasite rainfall

Characterization of Cd1-xZnxTe（0≤x≤1） Nanolayers Grown by Atomic layer Deposition on GaSb and GaAs（001） Oriented Substrates

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Journal of Electronic Science and Technology 2019年第2期17卷 97-108页

作者： Joel Díaz-reyes Roberto Saúl Castillo-Ojeda José Eladio Flores-Mena Center for Research in Applied Biotechnology Instituto Politécnico Nacional Tepetitla 90700 Mexico Universidad Politécnica de Pachuca Pachuca 43830 Mexico Faculty of Sciences of the Electronics Autonomous University of Puebla Puebla 72570 Mexico

ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (AlD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (lO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the lO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.

关键词： Ⅲ-Ⅴ substrates atomic layer deposition(AlD) defect generation mechanism ternary alloy Cd1-xZnxTe Zn and Cd mixture

Electrochemical and spectroscopic study of interfacial interactions between chalcopyrite and typical flotation process reagents

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International Journal of Minerals,Metallurgy and Materials 2016年第2期23卷 127-136页

作者： Gustavo Urbano Isabel lázaro Israel Rodríguez Juan luis reyes Roxana larios Roel Cruz Instituto de Metalurgia Universidad Autonotrla de San Luis PotosiAvSierra Leona 550Lomas 2a SeccionSan Luis PotosiS.L.P.78210Mexico Industrial Minera Mexico S.A.de C.V. San Luis PotosiS.L.P.Mexico Centro Universitario de Ciencias Exactas e Ingenierias Universidad de GuadalajaraGuadalajaraJaliscoMexico

Comparative voltammetry and differential double-layer capacitance studies were performed to evaluate interfacial interactions between cnalcopyrite（CuFeS2） and n-isopropyl xanthate（X） in the presence of ammonium bisulfite/39wt%SO2 and caustic starch at different pH *** spectroscopy,Fourier transform infrared（FTIR） spectroscopy,contact angle measurements,and microflotation tests were used to establish the type and extent of xanthate adsorption as well as the species involved under different mineral surface conditions in this *** results demonstrate that the species that favor a greater hydrophobicity of chalcopyrite are primarily CuX and S^0,whereas oxides and hydroxides of Cu and Fe as well as an excess of starch decrease the hydrophobicity.A conditioning of the mineral surface with ammonium bisulfite/39wt%SO2 at pH 6 promotes the activation of surface and enhances the xanthate ***,this effect is diminished at pH ≥ 8,when an excess of starch is added during the preconditioning step.

关键词： sulfide minerals chalcopyrite xanthates flotation interfacial reactions electrochemistry spectroscopy

Radicals and Kothe’s Conjecture for Skew PBW Extensions

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Communications in Mathematics and Statistics 2021年第2期9卷 119-138页

作者： Armando reyes Hector Suarez Departamento de Matematicas Universidad Nacional de ColombiaSede BogotaColombia Escuela de Matemáticas y Estadística Universidad Pedagogica y Tecnológica de ColombiaSede TunjaColombia

The aim of this paper is to investigate different radicals(Wedderburn radical,lower nil radical,levitzky radical,upper nil radical,the set of all nilpotent elements,the sum of all nil left ideals)of the noncommutative rings known as skew Poincare–Birkhoff–Witt *** characterize minimal prime ideals of these rings and prove that the Kothe’s conjecture holds for these ***,we establish the transfer of several ring-theoretical properties(reduced,symmetric,reversible,2-primal)from the coefficients ring of a skew PBW extension to the extension itself.

关键词： Armendariz rings Kothe’s conjecture Skew PBW extensions

The ρ-variation of the Hermitian Riesz Transform

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Acta Mathematica Sinica,English Series 2010年第10期26卷 1827-1838页

作者： Raquel CRESCIMBENI Francisco Javier MARTíN-reyes Alberto DE lA TORRE José l.TORREA Departamento de Matemática Universidad Nacional del Comahue Facultad de Economía y Administración Departamento de Análisis Matemático Facultad de Ciencias Universidad de Málaga Facultad de Ciencias Universidad Autónoma de Madrid ICMAT-CSIC-UAM-UCM-UC3M

In this paper we prove the behaviour in weighted lp spaces of the oscillation and variation of the Hilbert transform and the Riesz transform associated with the Hermite operator of dimension 1. We prove that this operator maps lP（R, w（x）dx） into itself when w is a weight in the Ap class for 1 〈 p 〈 ∞. For p = 1 we get weak type for the A1 class. Weighted estimated are also obtained in the extreme case p = ∞.

关键词： Oscillation-p-variation-singular integral-Hermite operator

The McCoy Condition on Skew Poincaré-Birkhoff-Witt Extensions

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Communications in Mathematics and Statistics 2021年第1期9卷 1-21页

作者： Armando reyes Camilo Rodriguez Departamento de Matematicas Universidad Nacional de ColombiaSede BogotaColombia

In this paper,we study the notion of McCoy ring over the class of non-commutative rings of polynomial type known as skew Poincare–Birkhoff–Witt *** a consequence,we generalize several results about this notion consi... 详细信息

关键词： McCoy ring Reversible ring Semicommutative ring Zip ring Skew Poincare–Birkhoff–Witt extension

A test method for evaluating the thermal environment of underground coal mine refuge alternatives

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International Journal of Mining Science and Technology 2019年第3期29卷 343-355页

作者： D.S.Yantek l.Yan N.W.Damiano M.A.reyes J.R.Srednicki CDC NIOSH

Since 2009,the Mine Safety and Health Administration(MSHA)has required mines to install refuge alternatives(RAs)in underground coal *** of the biggest concerns with occupied RAs is the possible severity of the resulting thermal *** 30 CFR 7.504,the maximum allowable apparent temperature(AT)for an occupied RA is specified as 35℃(95°F).Manufacturers must conduct heat/humidity tests to demonstrate that their RAs meet the 35℃(95°F)AT *** these tests,heat input devices are used to input the metabolic heat of actual miners.A wide variety of test methods,sensors,and heat input devices could be used when conducting such *** 2012,the National Institute for Occupational Safety and Health(NIOSH)has conducted over thirty 96-hour heat/humidity tests on four different *** paper discusses the test equipment and procedures used during these *** information is useful for RA manufacturers conducting RA heat/humidity tests,for other researchers investigating RA heat/humidity buildup,and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge.

关键词： Refuge chamber Refuge alternative Confined space Thermal environment Test method Temperature

Using music to reduce anxiety among older adults in the emergency department:a randomized pilot study

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Journal of Integrative Medicine 2017年第6期15卷 450-455页

作者： laura Belland laura Rivera-reyes Ula Hwang center for family medicine newyork-presbyterian/columbia university medical centerNew YorkNY 10032USA department of emergency medicine icahn school of medicine at mount sinaiNew YorkNY 10029USA geriatric research education and clinical centerjames j.peters vamcNew YorkNY 10029USA

BACKGROUND： An emergency department （ED） visit may be distressing and anxiety-provoking for older adults （age 〉 65 years）. No studies have specifically evaluated the effect of music listening on anxiety in older adults in the ED. OBJECTIVE： The objective of this pilot study was to evaluate the effect of music listening on anxiety levels in older ED patients. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This was a randomized pilot study in the geriatric ED of an urban academic tertiary medical center. This was a sample of English-speaking adults （age 〉 65 years） who were not deaf （n = 35）. Subjects consented to participate and were randomized to receive up to 60 min of music listening with routine care, while the control group received routine care with no music. Subjects in the music treatment group received headphones and an electronic tablet with pre-downloaded music, and were allowed to choose from 5 selections. MAIN OUTCOME MEASURES： The primary outcome was change in anxiety levels, measured by the state- trait anxiety inventory （STAI）, at enrollment and 1 h later. RESUlTS： A total of 35 participants were enrolled： 74% were female, 40% were white, and 40% were black; of these, 32 subjects completed the study protocol. When comparing control （n = 18） against intervention subjects （n = 17）, there were no significant differences in enrollment STAI scores （43.00 ± 15.00 vs. 40.30± 12.80, P = 0.57）. STAI scores 1 hour after enrollment （after the music intervention） were significantly reduced in the intervention subjects compared to the control subjects （with reduction of 10.00± 12.29 vs. 1.88 ± 7.97, P = 0.03）. CONClUSION： These pilot results suggest that music listening may be an effective tool for reducing anxiety among older adults in the ED.

关键词： music anxiety emergency department randomized controlled trial