cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Black Holes Surrounded by Uniformly Rotating Rings
Creators: name: Ansorg, Marcus
name: Petroff, David
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Highly accurate numerical solutions to the problem of Black Holes surrounded by uniformly rotating rings in axially symmetric, stationary spacetimes are presented. The numerical methods developed to handle the problem are discussed in some detail. Related Newtonian problems are described and numerical results provided, which show that configurations can reach an inner mass-shedding limit as the mass of the central object increases. Exemplary results for the full relativistic problem for rings of constant density are given and the deformation of the event horizon due to the presence of the ring is demonstrated. Finally, we provide an example of a system for which the angular momentum of the central Black Hole divided by the square of its mass exceeds one.
description: 12 pages, 14 figures, revtex, v4: minor changes, Eq. (17) corrected, corresponds to version in PRD
Hedging Effectiveness around USDA Crop Reports
Creators: name: Singh, Navinderpal
name: McKenzie, Andrew M.
name: Singh, Navinderpal
name: McKenzie, Andrew M.
Publisher: name: Unknown
Year: 2008
Subjects: Agribusiness
Research Methods/ Statistical Methods

description: It is well documented that “unanticipated” information contained in USDA crop reports induces large price reactions in corn and soybean markets. Thus, a natural question that arises from this literature is: To what extent are futures hedges able to remove or reduce increased price risk around report release dates? This paper addresses this question by simulating daily futures returns, daily cash returns and daily hedged returns around report release dates for two storable commodities (corn and soybeans) in two market settings (North Central Illinois and Memphis Tennessee). Various risk measures, including “Value at Risk,” are used to determine hedging effectiveness, and “Analysis of Variance” is used to uncover the underlying factors that contribute to hedging effectiveness.
An Eulerian Vlasov-Fokker-Planck Algorithm for Spherical Implosion Simulations of Inertial Confinement Fusion Capsules
Creators: name: Taitano, William T.
name: Keenan, Brett D.
name: Chacon, Luis
name: Anderson, Steven E.
name: Hammer, Hans R.
name: Simakov, Andrei N.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We present a numerical algorithm that enables a phase-space adaptive Eulerian Vlasov-Fokker-Planck (VFP) simulation of an inertial confinement fusion (ICF) capsule implosion. The approach relies on extending a recent mass, momentum, and energy conserving phase-space moving-mesh adaptivity strategy to spherical geometry. In configuration space, we employ a mesh motion partial differential equation (MMPDE) strategy while, in velocity space, the mesh is expanded/contracted and shifted with the plasma's evolving temperature and drift velocity. The mesh motion is dealt with by transforming the underlying VFP equations into a computational (logical) coordinate, with the resulting inertial terms carefully discretized to ensure conservation. To deal with the spatial and temporally varying dynamics in a spherically imploding system, we have developed a novel nonlinear stabilization strategy for MMPDE in the configuration space. The strategy relies on a nonlinear optimization procedure that optimizes between mesh quality and the volumetric rate change of the mesh to ensure both accuracy and stability of the solution. Implosions of ICF capsules are driven by several boundary conditions: 1) an elastic moving wall boundary; 2) a time-dependent Maxwellian Dirichlet boundary; and 3) a pressure-driven Lagrangian boundary. Of these, the pressure-driven Lagrangian boundary driver is new to our knowledge. The implementation of our strategy is verified through a set of test problems, including the Guderley and Van-Dyke implosion problems --the first-ever reported using a Vlasov-Fokker-Planck model.
description: 62 pages, 34 figures
Eddy diffusivity in convective hydromagnetic systems
Creators: name: Baptista, M.
name: Gama, S. M. A.
name: Zheligovsky, V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: An eigenvalue equation, for linear instability modes involving large scales in a convective hydromagnetic system, is derived in the framework of multiscale analysis. We consider a horizontal layer with electrically conducting boundaries, kept at fixed temperatures and with free surface boundary conditions for the velocity field; periodicity in horizontal directions is assumed. The steady states must be stable to short (fast) scale perturbations and possess symmetry about the vertical axis, allowing instabilities involving large (slow) scales to develop. We expand the modes and their growth rates in power series in the scale separation parameter and obtain a hierarchy of equations, which are solved numerically. Second order solvability condition yields a closed equation for the leading terms of the asymptotic expansions and respective growth rate, whose origin is in the (combined) eddy diffusivity phenomenon. For about 10% of randomly generated steady convective hydromagnetic regimes, negative eddy diffusivity is found.
description: 18 pages. Added numerical reults. Submitted to European Physical Journal B
Increased Cocoa Bean Exports under Trade Liberalization: A Gravity Model Approach
Creators: name: Yeboah, Osei-Agyeman
name: Shaik, Saleem
name: Wozniak, Shawn J.
name: Allen, Albert J.
name: Yeboah, Osei-Agyeman
name: Shaik, Saleem
name: Wozniak, Shawn J.
name: Allen, Albert J.
Publisher: name: Unknown
Year: 2008
Subjects: subject: International Relations/Trade
subject: Research Methods/ Statistical Methods
subject: Gravity models
subject: Bilateral exports
subject: Market liberalization
subject: Cocoa
subject: Fixed Effects Model
subject: Random Effects Model
subject: Pooled O.L.S.

description: Gravity models were developed to estimate the potential bilateral exports of cocoa under trade liberalization by the sixteen major cocoa producing countries to the US using panel data from 1989 to 2003. The results indicate that differences between resource endowment, relative size of economies, and the sum of bilateral GDP of U.S. and exporting countries are the major determinants. Thus, as trade is liberalized, farmers share of the world price of cocoa increases and this raises exports.
Maximum Angle of Stability of a Wet Granular Pile
Creators: name: Nowak, Sarah
name: Samadani, Azadeh
name: Kudrolli, Arshad
Publisher: name: arXiv
Year: 2005
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Anyone who has built a sandcastle recognizes that the addition of liquid to granular materials increases their stability. However, measurements of this increased stability often conflict with theory and with each other [1-7]. A friction-based Mohr-Coulomb model has been developed [3,8]. However, it distinguishes between granular friction and inter-particle friction, and uses the former without providing a physical mechanism. Albert, {\em et al.} [2] analyzed the geometric stability of grains on a pile's surface. The frictionless model for dry particles is in excellent agreement with experiment. But, their model for wet grains overestimates stability and predicts no dependence on system size. Using the frictionless model and performing stability analysis within the pile, we reproduce the dependence of the stability angle on system size, particle size, and surface tension observed in our experiments. Additionally, we account for past discrepancies in experimental reports by showing that sidewalls can significantly increase the stability of granular material.
description: 4 pages, 4 figures
A Matrix Model for Black Hole Thermalization
Creators: name: Iizuka, Norihiro
name: Polchinski, Joseph
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a matrix model which is intended as a toy model of the gauge dual of an AdS black hole. In particular, it captures the key property that at infinite $N$ correlators decay to zero on long time scales, while at finite $N$ this cannot happen. The model consists of a harmonic oscillator in the adjoint which acts as a heat bath for a particle in the fundamental representation. The Schwinger-Dyson equation reduces to a closed recursion relation, which we study by various analytical and numerical methods. We discuss some implications for the information problem.
description: 23 pages, 5 eps figures. v2: expanded discussion of model, added references. v3: slightly expanded conclusions
Impacts of the physical data model on the forward inference of initial conditions from biased tracers
Creators: name: Nguyen, Nhat-Minh
name: Schmidt, Fabian
name: Lavaux, Guilhem
name: Jasche, Jens
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We investigate the impact of each ingredient in the employed physical data model on the Bayesian forward inference of initial conditions from biased tracers at the field level. Specifically, we use dark matter halos in a given cosmological simulation volume as tracers of the underlying matter density field. We study the effect of tracer density, grid resolution, gravity model, bias model and likelihood on the inferred initial conditions. We find that the cross-correlation coefficient between true and inferred phases reacts weakly to all ingredients above, and is well predicted by the theoretical expectation derived from a Gaussian model on a broad range of scales. The bias in the amplitude of the inferred initial conditions, on the other hand, depends strongly on the bias model and the likelihood. We conclude that the bias model and likelihood hold the key to an unbiased cosmological inference. Together they must keep the systematics -- which arise from the sub-grid physics that are marginalized over -- under control in order to obtain an unbiased inference.
description: 29 pages, 11 figures, 1 table; main results in Sec 4.2; comments welcome. v2: Match JCAP accepted version (no major change), update references. v3: Fix links, typos and further update reference info. v4: Match JCAP published version, fix an incorrect link and line spacing
Transcription of the narration of Reel #5 (collection LA 256)
Creators: name: Parker, Verdena
name: Kelly, Christine
name: Spence, Justin
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2020
Subjects: subject: hup

description: Audio files VP-120316-08a/c: transcription of VP-161215-01 (narration of Reel #5 from the LA 256 collection at SCOIL, one of six reels of 8mm film created by Verdena in the 1960s, featuring scenes of everyday life around Hoopa Valley as well as Brush Dances). Edited file (51 seconds of preamble by J. Spence deleted in order to align video) from 10:34 to 12:42. Due to re-numbering, Reel #5 has been assigned the CLA item number LA 256.044.
Clouds in Three-Dimensional Models of Hot Jupiters Over a Wide Range of Temperatures I: Thermal Structures and Broadband Phase Curve Predictions
Creators: name: Roman, Michael T.
name: Kempton, Eliza M. -R.
name: Rauscher, Emily
name: Harada, Caleb K.
name: Bean, Jacob L.
name: Stevenson, Kevin B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Using a general circulation model (GCM), we investigate trends in simulated hot Jupiter atmospheres for a range of irradiation temperatures (1,500 - 4,000 K), surface gravities (10 and 40 m s-2), and cloud conditions. Our models include simplified temperature-dependent clouds with radiative feedback and show how different cloud compositions, vertical thicknesses, and opacities shape hot Jupiters atmospheres by potentially increasing planetary albedos, decreasing photospheric pressures and nightside temperatures, and in some cases producing strong dayside thermal inversions. With decreasing irradiation, clouds progressively form on the nightside and cooler western limb followed by the eastern limb and central dayside. We find that clouds significantly modify the radiative transport and affect the observable properties of planets colder than T_irr ~ 3,000~K (T_eq~2,100 K) depending on the clouds' vertical extent. The precise strength of expected effects depends on the assumed parameters, but trends in predicted phase curves emerge from an ensemble of simulations. Clouds lead to larger phase curve amplitudes and smaller phase curve offsets at IR wavelengths, compared to cloud-free models. At optical wavelengths, we predict mostly westward phase curve offsets at intermediate temperatures (T_irr ~ 2,000 - 3,500 K) with clouds confined to the nightside and western limb. If clouds are vertically compact (i.e. on order of a pressure scale height in thickness), their distributions and effects become more complicated as different condensates form at different heights -- some too deep to significantly affect the observable atmosphere. Our results have implications for interpreting the diversity of phase curve observations of planets with T_irr
description: Accepted to ApJ. 34 pages, 16 figures
Multi-Hamiltonian structure of Plebanski's second heavenly equation
Creators: name: Neyzi, F.
name: Nutku, Y.
name: Sheftel, M. B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We show that Plebanski's second heavenly equation, when written as a first-order nonlinear evolutionary system, admits multi-Hamiltonian structure. Therefore by Magri's theorem it is a completely integrable system. Thus it is an example of a completely integrable system in four dimensions.
The spin-statistics connection in classical field theory
Creators: name: Morgan, J. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The spin-statistics connection is obtained for a simple formulation of a classical field theory containing even and odd Grassmann variables. To that end, the construction of irreducible canonical realizations of the rotation group corresponding to general causal fields is reviewed. The connection is obtained by imposing local commutativity on the fields and exploiting the parity operation to exchange spatial coordinates in the scalar product of classical field evaluated at one spatial location with the same field evaluated at a distinct location. The spin-statistics connection for irreducible canonical realizations of the Poincaré group of spin $j$ is obtained in the form: Classical fields and their conjugate momenta satisfy fundamental field-theoretic Poisson bracket relations for 2$j$ even, and fundamental Poisson antibracket relations for 2$j$ odd
description: 27 pages. Typos and sign error corrected; minor revisions to text
Effects of Tariff Liberalization due to EU Accession on Slovak Agricultural Trade
Creators: name: Drabik, Dusan
name: Pokrivcak, Jan
name: Ciaian, Pavel
name: Drabik, Dusan
name: Pokrivcak, Jan
name: Ciaian, Pavel
Publisher: name: Unknown
Year: 2007
Subjects: International Relations/Trade

description: The paper analyzes the changes in agricultural trade patterns in Slovakia that occured during the gradual trade liberalization due to European Union enlargement in 2004. The results indicate that approximately 30% of the increase in agricultural imports from the EU15 and CEECs between 2000 and 2005 was due to the discriminatory trade liberalization between Slovakia and the EU15 and CEECs, i.e. due to the formation of a customs union. Part of the increase in agricultural trade with the EU15 and CEECs was at the expense of trade with more efficient producers from the rest of the world, i.e. there is an indication that some trade diversion could have occurred. The second wave of agricultural trade liberalization (from 2002 onward) brought about greater effects in terms of the increase in agricultural imports from the EU15 and CEECs than was the case with the first wave.
Impacts of Observation Deleting Standards on Profitability Analysis of Precision Agriculture
Creators: name: Song, Baohui
name: Dillon, Carl R.
name: Mueller, Thomas
name: Song, Baohui
name: Dillon, Carl R.
name: Mueller, Thomas
Publisher: name: Unknown
Year: 2008
Subjects: Research Methods/ Statistical Methods

description: This research explores a possible reason for the inconsistent results from previous study on the profitability analysis in precision agriculture - different standards of identifying possible erroneous observations for PA datasets. By comparing the results from the different standards of identifying possible erroneous observations, this research raises concerns about the negative impacts of different standards of identifying possible erroneous observations on the profitability analysis of PA, and provides some suggestions for the standard which could be used in the future profitability analysis of PA.
The Contribution of Nonmarket Valuation to Policy: The Case of Nonfederal Hydropower Relicensing
Creators: name: Stephenson, Kurt
name: Shabman, Leonard A.
name: Stephenson, Kurt
name: Shabman, Leonard A.
Publisher: name: Unknown
Year: 2008
Subjects: Resource /Energy Economics and Policy

description: The contribution of nonmarket valuation studies to decisions about the operation of nonfederal hydroelectric facilities is examined. Hydropower licensing reforms by the Federal Energy Regulatory Commission to better weigh market and nonmarket tradeoffs did not require or use nonmarket valuation. License negotiation processes are interpreted as a substitute for valuation.
From pulses to circuits and back again: A quantum optimal control perspective on variational quantum algorithms
Creators: name: Magann, Alicia B.
name: Arenz, Christian
name: Grace, Matthew D.
name: Ho, Tak-San
name: Kosut, Robert L.
name: McClean, Jarrod R.
name: Rabitz, Herschel A.
name: Sarovar, Mohan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The last decade has witnessed remarkable progress in the development of quantum technologies. Although fault-tolerant devices likely remain years away, the noisy intermediate-scale quantum devices of today may be leveraged for other purposes. Leading candidates are variational quantum algorithms (VQAs), which have been developed for applications including chemistry, optimization, and machine learning, but whose implementations on quantum devices have yet to demonstrate improvements over classical capabilities. In this Perspective, we propose a variety of ways that the performance of VQAs could be informed by quantum optimal control theory. To set the stage, we identify VQAs and quantum optimal control as formulations of variational optimization at the circuit level and pulse level, respectively, where these represent just two levels in a broader hierarchy of abstractions that we consider. In this unified picture, we suggest several ways that the different levels of abstraction may be connected, in order to facilitate the application of quantum optimal control theory to VQA challenges associated with ansatz selection, optimization landscapes, noise, and robustness. A major theme throughout is the need for sufficient control resources in VQA implementations; we discuss different ways this need can manifest, outline a variety of open questions, and conclude with a look to the future.
RESOURCES OF WIND ENERGY AVAILABLE IN THE APSHERON PENINSULA OF THE REPUBLIC OF AZERBAIJAN AND THE POSSIBILITIES OF THEIR EFFECTIVE USE
Creators: name: Salamov O.
name: Mamedova L.
name: Aliyev F.
name: Gasimova, S.
Publisher: name: Colloquium-journal
Year: 2021
Subjects: wind cadastre
isodynamics
wind regimes
meteorological stations
weather vane
average wind speed
instantaneous wind speed
characteristics of repetition of instantaneous wind speed
calm hours
wind power unit.

description: The paper analyzes in detail the indicators of the meteorological stations installed on the Apsheron Peninsula, referring, according to the frequency distribution of various instantaneous wind speeds, to zone A, and it is revealed that in these territories the average annual wind speed is 5,9÷7,9 m/s. For these meteorological stations, at different average annual wind speeds, the numerical values of the repetition rates, in the annual cycle, in hours and in relative units, are determined and the results are shown in the table. During the study, first of all, we used the average monthly and average annual values of the wind speed observed at the height of the weather vane (9÷12 m), and then, by calculation, the numerical values of the average monthly, average annual and instantaneous wind speeds were determined. up to 150 m (every 10 m), which are shown in the form of a table and graph. The paper also gives the possible number of working hours and quiet hours of high-speed and low-speed wind power units (WPU), within one year, for the meteorological stations of Sumgait, Baku and Mashtagi. Analyzing the existing wind regimes, the possibilities of using WPU, with different capacities on the Absheron Peninsula, for individual and public purposes were indicated.
Structure of wavefunction for interacting bosons in mean-field with random $k$-body interactions
Creators: name: Rao, Priyanka
name: Chavda, N. D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Wavefunction structure is analyzed for dense interacting many-boson systems using Hamiltonian $H$, which is a sum of one-body $h(1)$ and an embedded GOE of $k$-body interaction $V(k)$ with strength $λ$. In the first analysis, a complete analytical description of the variance of the strength function as a function of $λ$ and $k$ is derived and the marker $λ_t$ defining thermalization region is obtained. In the strong coupling limit ($λ> λ_t$), the conditional $q$-normal density describes Gaussian to semi-circle transition in strength functions as body rank $k$ of the interaction increases. In the second analysis, this interpolating form of the strength function is utilized to describe the fidelity decay after $k$-body interaction quench and also to obtain the smooth form for the number of principal components, a measure of chaos in finite interacting many-particle systems. The smooth form very well describes embedded ensemble results for all $k$ values.
description: 27 pages, 8 figures
The Structure of U.S. Red Meat and Livestock Imports
Creators: name: Susanto, Dwi
name: Rosson, C. Parr
name: Henneberry, Shida Rastegari
name: Susanto, Dwi
name: Rosson, C. Parr
name: Henneberry, Shida Rastegari
Publisher: name: Unknown
Year: 2008
Subjects: International Relations/Trade
Livestock Production/Industries

description: The Flexible nonlinear almost ideal demand systems are estimated for U.S. import demand for red meat and livestock (live cattle and hogs). In estimating the model, expenditure endogeneity is imposed. Estimates of price elasticity suggest that fresh and frozen beef and live cattle are price elastic. Pork, sheep meat and hogs, on the other hand, are price inelastic. The study also finds that frozen beef and sheep meat, both mainly supplied by Australia and New Zealand, are expenditure elastic; whereas fresh beef, pork, live cattle and hogs are expenditure inelastic.
Properties of heaviest nuclei with $98\leq Z \leq 126$ and $134 \leq N \leq 192$
Creators: name: Jachimowicz, P.
name: Kowal, M.
name: Skalski, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We systematically determine ground-state and saddle-point shapes and masses for 1305 heavy and superheavy nuclei with $Z=98-126$ and $N=134-192$, including odd-$A$ and odd-odd systems. From these, we derive static fission barrier heights, one- and two-nucleon separation energies, and $Q_α$ values for g.s. to g.s transitions. Our study is performed within the microscopic-macroscopic method with the deformed Woods-Saxon single-particle potential and the Yukawa-plus-exponential macroscopic energy taken as the smooth part. We use parameters of the model that were fitted previously to masses of even-even heavy nuclei. For systems with odd numbers of protons, neutrons, or both, we use a standard BCS method with blocking. Ground-state shapes and energies are found by the minimization over seven axially-symmetric deformations. A search for saddle-points was performed by using the "imaginary water flow" method in three consecutive stages, using five- (for nonaxial shapes) and seven-dimensional (for reflection-asymmetric shapes) deformation spaces. The results are collected in two main tables. Calculated ground-state mass excess, nucleon separation- and $Q_α$ energies, total, macroscopic(normalized to the macroscopic energy at the spherical shape) and shell corrections energies, and deformations are given for each nucleus in \mbox{Table 1}. \mbox{Table 2} contains calculated properties of the saddle-point configurations and the fission barrier heights. In \mbox{Tables 3-7}, are given calculated ground-state, inner and outer saddle-point and superdeformed secondary minima characteristics for 75 actinide nuclei, from Ac to Cf, for which experimental estimates of fission barrier heights are known. These results are an additional test of our model.
description: Submitted to ADNDT. arXiv admin note: text overlap with arXiv:1203.5013
Demand System Analysis of the South Korean Beef Market with the Free Trade Demand Model
Creators: name: Lee, Young-Jae
name: Kennedy, P. Lynn
name: Lee, Young-Jae
name: Kennedy, P. Lynn
Publisher: name: Unknown
Year: 2008
Subjects: Demand and Price Analysis
International Relations/Trade
Research Methods/ Statistical Methods

description: In this study a demand system analysis for beef in South Korea is constructed. A free trade demand system was used in which the economic welfare of market participants are maximized. Recognizing implicit discrimination about non-locally sourced beef products, this study deduces market demand equations with respect to consumer preference in order to identify the marginal effect of change consumer preference has on market demand.
Theoretical Examination of the Conditions of Best Management Practices Adoption and the Easing of Trade Distortion for Sugar
Creators: name: Lee, Young-Jae
name: Lee, Young-Jae
Publisher: name: Unknown
Year: 2008
Subjects: Agribusiness

description: In this study it is examined to see that if the government subsidy compensating for the additional cost of adopting best management practices (BMP) is equal to marginal net benefit, will farmers then try to adopt BMP at every level of TRQ and FMA without exhibiting concerns over the form of their production function and, also, will this then imply an ability on the part of the government to lighten importing and market restrictions on sugar.
title: La letteratura italiana e il concetto di maternità
Creators: name: Delogu, Lucy
Publisher: name: Edizioni Ca' Foscari - Digital Publishing
Year: 2015

description: Una raccolta di saggi scritti da ricercatori di diversi paesi sul ruolo della madre nella letteratura italiana. Un viaggio che tocca diversi periodi della storia italiana, grazie agli autori italiani che hanno affrontato in diverse maniere il tema della maternità. I saggi mettono in luce quindi il ruolo della maternità che ha avuto in ogni autore e le implicazioni sociali e culturali che li hanno mossi.
description: Innesti/Crossroads, volume 7
Full-duplex Reflective Beamsteering Metasurface Featuring Magnetless Nonreciprocal Amplification
Creators: name: Taravati, Sajjad
name: Eleftheriades, George V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nonreciprocal radiation refers to electromagnetic wave radiation in which a structure provides different responses under the change of the direction of the incident field. Modern wireless telecommunication systems demand versatile apparatuses which are capable of full-duplex nonreciprocal wave processing and amplification, especially in the reflective state. To realize such a unique, extraordinary and versatile functionality, we propose an architecture in which a chain of series cascaded radiating patches are integrated with nonreciprocal phase shifters, providing an original and efficient apparatus for full-duplex reflective beamsteering. Such an ultrathin reflective metasurface can provide directive and diverse radiation beams, large wave amplification, steerable beams by simply changing the bias of the gradient active nonmagnetic nonreciprocal phase shifters, and is immune to undesired time harmonics. Having accomplished all these functionalities in the reflective state, the metasurface represents a conspicuous apparatus for efficient, controllable and programmable wave engineering.
Difficulties with the QPOs Resonance Model
Creators: name: Rebusco, Paola
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: High frequency quasi-periodic oscillations (HFQPOs) have been detected in microquasars and neutron star systems. The resonance model suggested by Kluzniak & Abramowicz (2000) explains twin QPOs as two weakly coupled nonlinear resonant epicyclic modes in the accretion disk. Although this model successfully explains many features of the observed QPOs, it still faces difficulties and shortcomings. Here we summarize the aspects of the theory that remain a puzzle and we briefly discuss likely developments.
description: To appear in New Astronomy Review, Proceedings of "Jean-Pierre Lasota, X-ray binaries, accretion disks and compact stars" (October 2007); Ed. M. Abramowicz
title: КОЛОРЕКТАЛЬНЫЕ ЭПИТЕЛИАЛЬНЫЕ НОВООБРАЗОВАНИЯ НА СТАДИИ ДИСПЛАЗИИ ЛЕГКОЙ СТЕПЕНИ: ГЕНДЕРНЫЕ, ВОЗРАСТНЫЕ И МЕТРОЛОГИЧЕСКИЕ РАЗЛИЧИЯ ПРИ ЭНДОСКОПИЧЕСКОЙ ДИАГНОСТИКЕ
title: COLORECTAL EPITHELIAL NEOPLASMS AT STAGE OF LOW-GRADE DYSPLASIA: GENDER, AGE AND METROLOGICAL DIFFERENCES IN ENDOSCOPIC DIAGNOSIS
Creators: name: Деге, Олег Владимирович
name: Дарвин, Владимир Васильевич
name: Алмазова, Елена Геннадьевна
name: Деге, Юлия Евгеньевна
Publisher: name: Издательский центр СурГУ
Year: 2018

description: Цель – выявление особенностей эпидемиологии, метрологии и морфологии колоректальных эпителиальных новообразований на стадии дисплазии легкой степени. Из 8 294 видеоколоноскопий были выделены 2 группы: пациенты без дисплазии и эпителиального рака и обследуемые с дисплазией легкой степени. Среди них выявлены статистически достоверные гендерные, топографоанатомические, метрологические, морфологические различия.
description: The aim of the article is to research epidemiological, metrological and morphological features of colorectal epithelial neoplasms at the stage of low-grade dysplasia. Two groups were formed according to results of 8294 videocolonoscopies: patients without dysplasia and epithelial cancer, and the examined with low-grade dysplasia. Statistically significant gender, topographical anatomical, metrological, morphological differences are revealed among them.
A conservative fully-discrete numerical method for the regularised shallow water wave equations
Creators: name: Mitsotakis, Dimitrios
name: Ranocha, Hendrik
name: Ketcheson, David I.
name: Süli, Endre
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: The paper proposes a new, conservative fully-discrete scheme for the numerical solution of the regularised shallow water Boussinesq system of equations in the cases of periodic and reflective boundary conditions. The particular system is one of a class of equations derived recently and can be used in practical simulations to describe the propagation of weakly nonlinear and weakly dispersive long water waves, such as tsunamis. Studies of small-amplitude long waves usually require long-time simulations in order to investigate scenarios such as the overtaking collision of two solitary waves or the propagation of transoceanic tsunamis. For long-time simulations of non-dissipative waves such as solitary waves, the preservation of the total energy by the numerical method can be crucial in the quality of the approximation. The new conservative fully-discrete method consists of a Galerkin finite element method for spatial semidiscretisation and an explicit relaxation Runge--Kutta scheme for integration in time. The Galerkin method is expressed and implemented in the framework of mixed finite element methods. The paper provides an extended experimental study of the accuracy and convergence properties of the new numerical method. The experiments reveal a new convergence pattern compared to standard Galerkin methods.
title: ÐÑÐ»Ð»ÐµÑÐµÐ½Ñ Ð½Ð¾Ð²ÑÑ Ð¿Ð¾ÑÑÑÐ¿Ð»ÐµÐ½Ð¸Ð¹ Ð·Ð° Ð´ÐµÐºÐ°Ð±ÑÑ 2023 Ð³Ð¾Ð´Ð°
title: Ð¸Ð½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¾Ð½Ð½ÑÐ¹ Ð±ÑÐ»Ð»ÐµÑÐµÐ½Ñ
titleType: Subtitle
Creators: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑ Ð½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾. ÐÐ½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¾Ð½Ð½Ð¾-Ð±Ð¸Ð±Ð»Ð¸Ð¾ÑÐµÑÐ½ÑÐ¹ ÐºÐ¾Ð¼Ð¿Ð»ÐµÐºÑ
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2024
Subjects: Ð±Ð¸Ð±Ð»Ð¸Ð¾Ð³ÑÐ°ÑÐ¸Ñ
Ð±Ð¸Ð±Ð»Ð¸Ð¾ÑÐµÑÐ½ÑÐµ ÑÐ¾Ð½Ð´Ñ

description: Ð Ð½Ð°ÑÑÐ¾ÑÑÐ¸Ð¹ Â«ÐÑÐ»Ð»ÐµÑÐµÐ½ÑÂ» Ð²ÐºÐ»ÑÑÐµÐ½Ñ Ð¸Ð½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¾Ð½Ð½ÑÐµ ÑÐµÑÑÑÑÑ, Ð¿Ð¾ÑÑÑÐ¿Ð¸Ð²ÑÐ¸Ðµ Ð² Ð¿Ð¾Ð´ÑÐ°Ð·Ð´ÐµÐ»ÐµÐ½Ð¸Ñ ÐÐ½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¾Ð½Ð½Ð¾-Ð±Ð¸Ð±Ð»Ð¸Ð¾ÑÐµÑÐ½Ð¾Ð³Ð¾ ÐºÐ¾Ð¼Ð¿Ð»ÐµÐºÑÐ° Ð¡ÐÐ±ÐÐ£ Ð² Ð´ÐµÐºÐ°Ð±ÑÐµ 2023 Ð³Ð¾Ð´Ð°. Â«ÐÑÐ»Ð»ÐµÑÐµÐ½ÑÂ» ÑÐ¾ÑÑÐ°Ð²Ð»ÐµÐ½ Ð½Ð° Ð¾ÑÐ½Ð¾Ð²Ðµ Ð·Ð°Ð¿Ð¸ÑÐµÐ¹ ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½Ð¾Ð³Ð¾ ÐºÐ°ÑÐ°Ð»Ð¾Ð³Ð°. ÐÐ°Ð¿Ð¸ÑÐ¸ ÑÐ´ÐµÐ»Ð°Ð½Ñ Ð² ÑÐ¾ÑÐ¼Ð°ÑÐµ RUSMARC Ñ Ð¸ÑÐ¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°Ð½Ð¸ÐµÐ¼ Ð¿ÑÐ¾Ð³ÑÐ°Ð¼Ð¼Ñ Â«Ð ÑÑÐ»Ð°Ð½-ÐÐµÐ¾Â». ÐÐ°ÑÐµÑÐ¸Ð°Ð» ÑÐ°ÑÐ¿Ð¾Ð»Ð¾Ð¶ÐµÐ½ Ð² ÑÐ¸ÑÑÐµÐ¼Ð°ÑÐ¸ÑÐµÑÐºÐ¾Ð¼ Ð¿Ð¾ÑÑÐ´ÐºÐµ Ð¿Ð¾ Ð¾ÑÑÐ°ÑÐ»ÑÐ¼ Ð·Ð½Ð°Ð½Ð¸Ñ, Ð²Ð½ÑÑÑÐ¸ ÑÐ°Ð·Ð´ÐµÐ»Ð¾Ð² â Ð² Ð°Ð»ÑÐ°Ð²Ð¸ÑÐµ Ð°Ð²ÑÐ¾ÑÐ¾Ð² Ð¸ Ð·Ð°Ð³Ð»Ð°Ð²Ð¸Ð¹. ÐÐ°Ð¿Ð¸ÑÐ¸ Ð²ÐºÐ»ÑÑÐ°ÑÑ Ð¿Ð¾Ð»Ð½Ð¾Ðµ Ð±Ð¸Ð±Ð»Ð¸Ð¾Ð³ÑÐ°ÑÐ¸ÑÐµÑÐºÐ¾Ðµ Ð¾Ð¿Ð¸ÑÐ°Ð½Ð¸Ðµ Ð¸Ð·Ð´Ð°Ð½Ð¸Ð¹, Ð¸Ð½Ð²ÐµÐ½ÑÐ°ÑÐ½ÑÐ¹ Ð½Ð¾Ð¼ÐµÑ Ð¸ Ð½Ð°Ð·Ð²Ð°Ð½Ð¸Ðµ Ð¾ÑÐ´ÐµÐ»Ð° ÑÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð² ÑÐ¾ÐºÑÐ°ÑÐµÐ½Ð½Ð¾Ð¼ Ð²Ð¸Ð´Ðµ (ÑÐ¸ÑÑ Ð¾ÑÐ´ÐµÐ»Ð°). Ð¡Ð¿Ð¸ÑÐ¾Ðº ÑÐ¾ÐºÑÐ°ÑÐµÐ½Ð¸Ð¹ Ð¿ÑÐ¸Ð²Ð¾Ð´Ð¸ÑÑÑ Ð² Â«ÐÑÐ»Ð»ÐµÑÐµÐ½ÐµÂ». Ð Ð½Ð°ÑÑÐ¾ÑÑÐµÐ¼ Ð¸Ð·Ð´Ð°Ð½Ð¸Ð¸ Ð¾ÑÑÐ°Ð¶ÐµÐ½Ñ ÐºÐ½Ð¸Ð³Ð¸ Ð¸ ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½ÑÐµ ÑÐµÑÑÑÑÑ â Ð¿Ð¾Ð»Ð½Ð¾ÑÐµÐºÑÑÐ¾Ð²ÑÐµ Ð´Ð¾ÐºÑÐ¼ÐµÐ½ÑÑ, Ð¿ÑÐµÐ´ÑÑÐ°Ð²Ð»ÐµÐ½Ð½ÑÐµ Ð² ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½Ð¾Ð¼ ÐºÐ°ÑÐ°Ð»Ð¾Ð³Ðµ Ð² ÑÐ¾ÑÐ¼Ð°ÑÐ°Ñ pdf Ð¸ html, Ð° ÑÐ°ÐºÐ¶Ðµ Ð¿ÐµÑÐµÑÐµÐ½Ñ Ð´Ð¾ÑÑÑÐ¿Ð½ÑÑ Ð±Ð°Ð· Ð´Ð°Ð½Ð½ÑÑ. ÐÐ»Ñ ÐºÐ°Ð¶Ð´Ð¾Ð³Ð¾ ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½Ð¾Ð³Ð¾ ÑÐµÑÑÑÑÐ° ÑÐºÐ°Ð·Ð°Ð½ URL-Ð°Ð´ÑÐµÑ. Ð Â«ÐÑÐ»Ð»ÐµÑÐµÐ½ÐµÂ» Ð¾ÑÐ´ÐµÐ»ÑÐ½Ð¾ Ð¾ÑÑÐ°Ð¶ÐµÐ½Ñ Ð¸Ð·Ð´Ð°Ð½Ð¸Ñ, Ð¿Ð¾Ð»ÑÑÐµÐ½Ð½ÑÐµ Ð±Ð¸Ð±Ð»Ð¸Ð¾ÑÐµÐºÐ¾Ð¹ Ð² ÐºÐ°ÑÐµÑÑÐ²Ðµ Ð¿Ð¾Ð¶ÐµÑÑÐ²Ð¾Ð²Ð°Ð½Ð¸Ð¹. Ð ÐºÐ¾Ð½ÑÐµ Ð±ÑÐ»Ð»ÐµÑÐµÐ½Ñ Ð¿ÑÐ¸Ð²ÐµÐ´ÐµÐ½ ÑÐ¿Ð¸ÑÐ¾Ðº Ð¿ÐµÑÐ¸Ð¾Ð´Ð¸ÑÐµÑÐºÐ¸Ñ Ð¸Ð·Ð´Ð°Ð½Ð¸Ð¹ Ð´Ð»Ñ ÐµÐ´Ð¸Ð½Ð¾Ð³Ð¾ Ð±Ð¸Ð±Ð»Ð¸Ð¾ÑÐµÑÐ½Ð¾Ð³Ð¾ ÑÐ¾Ð½Ð´Ð° Ð½Ð° Ð´ÐµÐºÐ°Ð±ÑÑ 2023 Ð³Ð¾Ð´Ð°.
L'accès à l'aide à mourir pour les personnes atteintes de démence, les enjeux bioéthiques ainsi que la responsabilité infirmière
Creators: name: Roch, Laura
name: Romo Ricardo, Thaïs
Publisher: name: Unknown
Year: 0
Subjects: subject: démence
subject: euthanasie
subject: directives anticipées
subject: souffrance
subject: capacité de discernement
subject: plan de soins anticipés
subject: hesav TB SI

description: Contexte : En Belgique et aux Pays-Bas, les déclarations anticipées d’euthanasie sont légales depuis 2002, y compris pour les personnes atteintes de démence, à contrario de la Suisse. Les demandes d’aide à mourir dans cette population représentent un défi pour les soignants. Objectifs : Le but de cette recherche est de déterminer quelles sont les conditions qui rendent acceptable l’accès à l’aide à mourir pour les personnes atteintes de démence d’un point de vue infirmier. Méthode : Ce travail est basé sur une revue de littérature. Les articles ont été sélectionnés sur les bases de données PubMed et CINHAL. Les résultats pertinents pour la recherche ont été extrait à partir des concepts définis dans le cadre théorique : le contexte légal, la notion de capacité de discernement, la théorie de la dignité et la souffrance intolérable. Résultats : Les déclarations anticipées d’euthanasie pour les personnes atteintes de démence ont de la peine à être acceptés. Ce travail démontre que l’altération de la capacité de discernement et la difficulté à évaluer la souffrance intolérable sont les principales raisons qui influencent les soignants dans leur décision. Discussion : La difficulté de la part des soignants à accepter les déclarations anticipées d’euthanasie pour les personnes atteintes de démence montre qu’il est indispensable de trouver une alternative : le plan de soins anticipé. Les compétences de l’infirmière lui permettront de valoriser l’autonomie et de mettre en avant les valeurs et les souhaits du patient. Grâce à ce processus, le patient exprimera son désir pour sa fin de vie accompagné par ses proches. De cette manière, les souhaits du patient seront respectés sans pouvoir être remis en cause.
Direct photon measurement in Au+Au collisions at $\sqrt{s_{NN}}$=200GeV a t RHIC
Creators: name: Sakaguchi, Takao
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Direct photon production in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV has been measured. The result is compared to several theoretical calculations, and found that it is not inconsistent with ones including thermal radiation from QGP or jet-photon conversion process on top of a NLO pQCD expectation. The direct photon contribution in dilepton measurement is also evaluated.
description: 3 pages, 2 figures. Contributed talk at PANIC '05 conference, Santa Fe, NM, Oct24-28, 2005
Symmetric inclusion-exclusion
Creators: name: Gessel, Ira M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05A15, 05A19, 60C05

description: One form of the inclusion-exclusion principle asserts that if A and B are functions of finite sets then A(S) is the sum of B(T) over all subsets T of S if and only if B(S) is the sum of (-1)^|S-T| A(T) over all subsets T of S. If we replace B(S) with (-1)^|S| B(S), we get a symmetric form of inclusion-exclusion: A(S) is the sum of (-1)^|T| B(T) over all subsets T of S if and only if B(S) is the sum of (-1)^|T| A(T) over all subsets T of S. We study instances of symmetric inclusion-exclusion in which the functions A and B have combinatorial or probabilistic interpretations. In particular, we study cases related to the Polya-Eggenberger urn model in which A(S) and B(S) depend only on the cardinality of S.
description: 10 pages
Vortex states in an acoustic Weyl crystal with a topological lattice defect
Creators: name: Wang, Qiang
name: Ge, Yong
name: Sun, Hong-xiang
name: Xue, Haoran
name: Jia, Ding
name: Guan, Yi-jun
name: Yuan, Shou-qi
name: Zhang, Baile
name: Chong, Yidong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We design and implement a three dimensional acoustic Weyl metamaterial hosting robust modes bound to a one-dimensional topological lattice defect. The modes are related to topological features of the bulk bands, and carry nonzero orbital angular momentum locked to the direction of propagation. They span a range of axial wavenumbers defined by the projections of two bulk Weyl points to a one-dimensional subspace, in a manner analogous to the formation of Fermi arc surface states. We use acoustic experiments to probe their dispersion relation, orbital angular momentum locked waveguiding, and ability to emit acoustic vortices into free space. These results point to new possibilities for creating and exploiting topological modes in three-dimensional structures through the interplay between band topology in momentum space and topological lattice defects in real space.
title: СИНДРОМ ПРОФЕССИОНАЛЬНОГО ВЫГОРАНИЯ У ВРАЧЕЙ БЮДЖЕТНЫХ ЛЕЧЕБНЫХ УЧРЕЖДЕНИЙ Г. СУРГУТА
title: BURNOUT SYNDROME IN DOCTORS OF BUDGETARY HEALTH FACILITIES OF SURGUT
Creators: name: Смертина, Любовь Порфирьевна
name: Мовсумов, Вели Зеллабдун оглы
Publisher: name: Издательский центр СурГУ
Year: 2018

description: Цель работы – проанализировать синдром профессионального выгорания у врачей бюджетных лечебных учреждений города Сургута. Изучены 40 анкет врачей стационаров бюджетных лечебных учреждений со стажем врачебной деятельности от 3 месяцев до 25 лет. В зависимости от стажа работы респонденты были поделены на 3 группы: стаж до 5 лет, от 6 до 15 и от 16 лет и выше. Синдром профессионального выгорания имел место у 98 % респондентов. Высокая и крайне его высокая степень были определены у 70 % врачей. Высокая степень синдрома профессионального выгорания чаще встречалась среди врачей со стажем более 16 лет. Предложены методы профилактики синдрома профессионального выгорания.
description: The aim of the article is to analyze the occupational burnout syndrome in doctors of budgetary health facilities in the city of Surgut. There were studied 40 questionnaires of Surgut doctors who have the employment period of medical activity from 3 months to 25 years. Depending on the length of service, respondents were divided into 3 groups: with experience up to 5 years, from 6 to 15 years and from 16 years and above. The occupational burnout syndrome is present in 98 % of respondents. A high and extremely high degree of the syndrome is recognized in 70 % of doctors. The high degree of burnout syndrome is more common among doctors with more than 16 years of working experience. Prevention techniques for the occupational burnout syndrome are suggested.
Agricultural land and community in British Columbia : UBC research farm and Oyster River community : towards an agri-culture
Creators: name: Muir, Sara Katherine
Publisher: name: University of British Columbia
Year: 2009

description: The Oyster River Research project begins by exploring the meaning of agriculture, the definition, the history, the cultural context of agri-culture, as well as the role of agriculture in our present day. An overview of the Agricultural Census 1992 is given to outline the Agricultural Industry past and present within Canada, and the major issues and constraints with regards to Agriculture in British Columbia are identified. Elements of farmland conservation, BC's ALR, as well as case studies and precedents regarding farmland conservation strategies are also discussed. From this research exploration, an understanding of the role and scope of UBC, the Oyster River Farm, and the surrounding community, locally and regionally is met, and programs capable of linking these issues are developed. These programs, in conjunction with the overall farm and community site design, exhibit the most beneficial means of defining and developing the relationship of UBC, the farm, and the community, while maintaining the integrity of agricultural land and the practice of farming for local food security. Ultimately, this design thesis offers a solution that attempts to serve UBC, the Oyster River Farm and the local / regional community in a manner most sensitive socially, ecologically, and economically to issues presently facing the Research Farm and the larger community of the Comox-Strathcona Regional District.
Solution methods for a class of finite-horizon vector-valued Markov decision processes
Creators: name: Mifrani, Anas
name: Saint-Pierre, Philippe
name: Savy, Nicolas
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Mathematical Sciences not elsewhere classified
subject: Science Policy
subject: Computational Biology

description: This paper investigates and develops solution methods for a class of finite-horizon Markov decision processes characterized by additive or multiplicative vector rewards. Two concepts of optimality are treated: (1) optimality in the space of return vectors, whereby a policy is optimal if it delivers a maximal total reward from any initial state; and (2) optimality in the space of return functions, whereby a policy is optimal if its total reward function is maximal among all total reward functions. The paper elucidates the relation between the two concepts, proposes a procedure for utilizing this relation to determine the set of optimal policies under concept (1), and formulates a dynamic programming approach to calculating optimal policies under concept (2). The paper demonstrates that dynamic programming yields all optimal policies under concept (2). The paper’s results are illustrated with numerical experiments and a multi-objective stochastic inventory control problem.