703 research outputs found
The Effect of Luxury Taxes on Competitive Balance, Club Profits, and Social Welfare in Sports Leagues
This paper provides a game-theoretic model of a professional sports league and analyzes the effect of luxury taxes on competitive balance, club profits and social welfare. We show that a luxury tax increases aggregate salary payments in the league as well as produces a more balanced league. Moreover, a higher tax rate increases the profits of large-market clubs, whereas the profits of small-market clubs only increase if the tax rate is not set inadequately high. Finally, we show that social welfare increases with a luxury tax.Sports League, Luxury Tax, Social Welfare, Competitive Balance
Social Welfare in Sports Leagues with Profit-Maximizing and/or Win-Maximizing Clubs
This paper develops a contest model to compare social welfare in homogeneous leagues in which all clubs maximize identical objective functions with mixed leagues in which clubs maximize different objective functions. We show that homogeneous leagues in which all clubs are profit-maximizers dominate all other leagues whereas mixed leagues in which small-market clubs are profit- and large-market clubs are win-maximizers (type-I mixed leagues) are dominated by all other leagues. In addition, we show that, from a welfare perspective, large-market clubs win too often in (purely) win-maximizing and type-I mixed leagues whereas small-market clubs win too many games in (purely) profit-maximizing leagues and in mixed leagues in which large-market clubs are profit- and small-market clubs are win-maximizers (type-II mixed leagues). These results have important policy implications: Social welfare will increase if clubs are reorganized from non-profit members associations to profit-maximizing corporations. Moreover, it is socially desirable to reorganize large-market clubs first because, in mixed leagues, it is better if large-market clubs maximize profits instead of small-market clubs. Finally, we show that the invariance proposition does not hold in any league. In mixed (homogeneous) leagues, revenue sharing decreases (increases) social welfare. Given these results, homogeneous leagues should introduce revenue sharing; mixed leagues should not.Social welfare, team sports leagues, objective functions, mixed leagues, competitive balance
Magnetic anisotropy of epitaxial (Ga,Mn)As on (113)A GaAs
The temperature dependence of magnetic anisotropy in (113)A (Ga,Mn)As layers
grown by molecular beam epitaxy is studied by means of superconducting quantum
interference device (SQUID) magnetometry as well as by ferromagnetic resonance
(FMR) and magnetooptical effects. Experimental results are described
considering cubic and two kinds of uniaxial magnetic anisotropy. The magnitude
of cubic and uniaxial anisotropy constants is found to be proportional to the
fourth and second power of saturation magnetization, respectively. Similarly to
the case of (001) samples, the spin reorientation transition from uniaxial
anisotropy with the easy along the [-1, 1, 0] direction at high temperatures to
the biaxial anisotropy at low temperatures is observed around 25 K. The
determined values of the anisotropy constants have been confirmed by FMR
studies. As evidenced by investigations of the polar magnetooptical Kerr
effect, the particular combination of magnetic anisotropies allows the
out-of-plane component of magnetization to be reversed by an in-plane magnetic
field. Theoretical calculations within the p-d Zener model explain the
magnitude of the out-of-plane uniaxial anisotropy constant caused by epitaxial
strain, but do not explain satisfactorily the cubic anisotropy constant. At the
same time the findings point to the presence of an additional uniaxial
anisotropy of unknown origin. Similarly to the case of (001) films, this
additional anisotropy can be explained by assuming the existence of a shear
strain. However, in contrast to the (001) samples, this additional strain has
an out-of-the-(001)-plane character.Comment: 13 pages, 9 figure
Проект ЭСПЦ на площадях ОАО «Волжский трубный завод» производительностью 1,2 млн. тонн стали в год
Реферат
Выпускная квалификационная работа содержит 136 с., 23 рисунка, 25 источников, 8 графического материала формата А1.
Ключевые слова: дуговая сталеплавильная печь (ДСП), агрегат внепечной обработки, машина непрерывной разливки стали (МНЛЗ), сталеразливочный ковш, электросталеплавильный цех (ЭСПЦ), марка стали.
Актуальность работы является в связи со сложной экономической ситуацией проблема импортозамещения трубной продукции для нужд нефтегазовой отрасли, и дальнейшее развитие газодобывающей отрасли потребует большого количества стальных труб.
Объектом исследования является электросталеплавильный цех на площадях завода ОАО «Волжский трубный завод».
Цель работы является разработка проекта ЭСПЦ.
В разделе объект и методы исследования описано организационная струReferat
Die Abschlussqualifikationsarbeit enthält 135 Seiten, 23 Zeichnungen, 25 Quellen, 8 A1 Zeichnungen.
Stichwörter: Lichtbogenstahlschmelzofen, Außerofenbearbeitungsmaschine, Stranggussmaschine, Stahlgießpfanne, Elektrostahlwerk, Stahlgüte.
Die Aktualität der Arbeit besteht darin, dass die wirtschaftliche Lage schwierig ist. Die Importsubstitution von Rohrprodukten für die Öl- und Gasindustrie sowie die weitere Entwicklung der Gasindustrie erfordern große Mengen von Stahlrohren.
Der Gegenstand der Arbeit ist Elektrostahlwerk des metallurgischen Betriebes Gesellschaft mit beschränkter Haftung «VTZ».
Das Ziel der Arbeit ist, das Elektrostahlwerk zu entwickeln, das die Installation des zweiten Lichtbogenstahlschmelzofens voraussetzt.
Im Teil „Objekt und Methoden der Forschung“ sind so
Hysteretic magnetoresistance and thermal bistability in a magnetic two-dimensional hole system
Colossal negative magnetoresistance and the associated field-induced
insulator-to-metal transition, the most characteristic features of magnetic
semiconductors, are observed in n-type rare earth oxides and chalcogenides,
p-type manganites, n-type and p-type diluted magnetic semiconductors (DMS) as
well as in quantum wells of n-type DMS. Here, we report on magnetostransport
studies of Mn modulation-doped InAs quantum wells, which reveal a magnetic
field driven and bias voltage dependent insulator-to-metal transition with
abrupt and hysteretic changes of resistance over several orders of magnitude.
These phenomena coexist with the quantised Hall effect in high magnetic fields.
We show that the exchange coupling between a hole and the parent Mn acceptor
produces a magnetic anisotropy barrier that shifts the spin relaxation time of
the bound hole to a 100 s range in compressively strained quantum wells. This
bistability of the individual Mn acceptors explains the hysteretic behaviour
while opening prospects for information storing and processing. At high bias
voltage another bistability, caused by the overheating of electrons10, gives
rise to abrupt resistance jumps
Collective electronic excitation in a trapped ensemble of photogenerated dipolar excitons and free holes revealed by inelastic light scattering
Photogenerated excitonic ensembles confined in coupled GaAs quantum wells were probed by a complementary approach of emission spectroscopy and resonant inelastic light scattering. Lateral electrostatic trap geometries were used to create dense systems of spatially indirect excitons and excess holes with similar densities in the order of 10(11) cm(-2.) Inelastic light scattering spectra reveal a very sharp low-lying collective mode that is identified at an energy of 0.44 meV and a full width at half maximum of only similar to 50 mu eV. This mode is interpreted as a plasmon excitation of the excess hole system coupled to the photogenerated indirect excitons. The emission energy of the indirect excitons shifts under the application of a perpendicular applied electric field, with the quantum-confined Stark effect unperturbed from the presence of free charge carriers. Our results illustrate the potential of studying low-lying collective excitations in photogenerated exciton systems to explore the many-body phase diagrams, related phase transitions, and interaction physics
Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions
Data taken with the ALEPH detector at LEP1 have been used to search for gamma
gamma production of the glueball candidates f0(1500) and fJ(1710) via their
decay to pi+pi-. No signal is observed and upper limits to the product of gamma
gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have
been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) <
0.31 keV and Gamma_(gamma gamma -> fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV
at 95% confidence level.Comment: 10 pages, 3 figure
Search for supersymmetry with a dominant R-parity violating LQDbar couplings in e+e- collisions at centre-of-mass energies of 130GeV to 172 GeV
A search for pair-production of supersymmetric particles under the assumption
that R-parity is violated via a dominant LQDbar coupling has been performed
using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV.
The observed candidate events in the data are in agreement with the Standard
Model expectation. This result is translated into lower limits on the masses of
charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for
m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81
GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the
95% confidence level for any generation structure of the LQDbar coupling.Comment: 32 pages, 30 figure
Search for CP Violation in the Decay Z -> b (b bar) g
About three million hadronic decays of the Z collected by ALEPH in the years
1991-1994 are used to search for anomalous CP violation beyond the Standard
Model in the decay Z -> b \bar{b} g. The study is performed by analyzing
angular correlations between the two quarks and the gluon in three-jet events
and by measuring the differential two-jet rate. No signal of CP violation is
found. For the combinations of anomalous CP violating couplings, and , limits of \hat{h}_b < 0.59h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st
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