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Search Results: 1 - 10 of 103 matches for " Thaddeus; "
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The Economic Value of Public Goods  [PDF]
Thaddeus Neil Cummins
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.518272
Abstract: This paper explores US entrepreneurial history and public budgets from President Eisenhower’s election in 1952 until the beginning of the Obama administration 2008. A mix of market forces, structural changes and a tendency toward unfettered capitalism [1] challenge diagnosis. This analysis examines these complexities with 216 business quarters of economic history. It also provides a mathematical model to characterize in broad strokes positive governance modeling for business. This work is important as economic growth ensures a nation’s ability to protect its citizens.
La antropología aplicada y la administración indígena en los Estados Unidos: 1934-1945
Blanchette, Thaddeus;
Desacatos , 2010,
Abstract: modern applied anthropology in the united states was born in the context of a reform leaded by the office of indian affairs (oia). our aim here is to offer an examination of the relationships between agents and institutions that were involved with applied anthropology in the oia, during the john collier administration. it was then, that an approximation to the modern notion of "indigenism" was born, a phase that represented the first systematic employment of anthropologists by a governmental institution in the united states. this matter is especially relevant for those scholars devoted to indigenism in latin america, since the inter-american indian institute was first conceived by collier, as a clearinghouse for anthropological knowledge and practices regarding indigenous peoples of the americas.
Mirror symmetry, Langlands duality, and commuting elements of Lie groups
Michael Thaddeus
Physics , 2000,
Abstract: By normalizing the space of commuting pairs of elements in a reductive Lie group G, and the corresponding space for the Langlands dual group, we construct pairs of hyperkahler orbifolds which satisfy the conditions to be mirror partners in the sense of Strominger-Yau-Zaslow. The same holds true for commuting quadruples in a compact Lie group. The Hodge numbers of the mirror partners, or more precisely their orbifold E-polynomials, are shown to agree, as predicted by mirror symmetry. These polynomials are explicitly calculated when G is a quotient of SL(n).
Variation of moduli of parabolic Higgs bundles
Michael Thaddeus
Mathematics , 2000,
Abstract: We study moduli spaces of parabolic Higgs bundles on a curve and their dependence on the choice of weights. We describe the chamber structure on the space of weights and show that, when a wall is crossed, the moduli space undergoes an elementary transformation in the sense of Mukai.
Geometric invariant theory and flips
Michael Thaddeus
Mathematics , 1994,
Abstract: We study the dependence of geometric invariant theory quotients on the choice of a linearization. We show that, in good cases, two such quotients are related by a flip in the sense of Mori, and explain the relationship with the minimal model programme. Moreover, we express the flip as the blow-up and blow-down of specific ideal sheaves, leading, under certain hypotheses, to a quite explicit description of the flip. We apply these ideas to various familiar moduli problems, recovering results of Kirwan, Boden-Hu, Bertram-Daskalopoulos- Wentworth, and the author. Along the way we display a chamber structure, following Duistermaat-Heckman, on the space of all linearizations. We also give a new, easy proof of the Bialynicki-Birula decomposition theorem.
A perfect Morse function on the moduli space of flat connections
Michael Thaddeus
Mathematics , 1998,
Abstract: The moduli space of flat SU(2) connections on a punctured surface, having prescribed holonomy around the punctures, is a compact smooth manifold if the prescription is generic. This paper gives a direct, elementary proof that the trace of the holonomy around a certain loop determines a Bott-Morse function on the moduli space which is perfect, meaning that the Morse inequalities are equalities. This leads to an attractive recursion for the Betti numbers of the moduli space, which agrees with the Harder-Narasimhan formula in the case of one puncture with holonomy -1.
Stable pairs, linear systems and the Verlinde formula
Michael Thaddeus
Mathematics , 1992,
Abstract: We study the moduli problem of pairs consisting of a rank 2 vector bundle and a nonzero section over a fixed smooth curve. The stability condition involves a parameter; as it varies, we show that the moduli space undergoes a sequence of flips in the sense of Mori. As applications, we prove several results about moduli spaces of rank 2 bundles, including the Harder-Narasimhan formula and the SU(2) Verlinde formula. Indeed, we prove a general result on the space of sections of powers of the ideal sheaf of a curve in projective space, which includes the Verlinde formula.
Complete collineations revisited
Michael Thaddeus
Mathematics , 1998,
Abstract: The space of complete collineations is a compactification of the space of matrices of fixed dimension and rank, whose boundary is a divisor with normal crossings. It was introduced in the 19th century and has been used to solve many enumerative problems. We show that this venerable space can be understood using the latest quotient constructions in algebraic geometry. Indeed, there is a detailed analogy between the complete collineations and the moduli space of stable pointed curves of genus zero. The remarkable results of Kapranov exhibiting the latter space as a Chow quotient, Hilbert quotient, and so on, all have counterparts for complete collineations. This analogy encompasses Vainsencher's construction of the complete collineations, as well as a form of the Gel'fand-MacPherson correspondence. There is also a tangential relation with the Gromov-Witten invariants of Grassmannians. The symmetric and anti-symmetric versions of the problem are considered as well. An appendix explains the original motivation, which came from the space of broken Morse flows for the moment map of a circle action.
Performance Optimization of Dual Pressure Heat Recovery Steam Generator (HRSG) in the Tropical Rainforest  [PDF]
Sidum Adumene, Barinaadaa Thaddeus Lebele-Alawa
Engineering (ENG) , 2015, DOI: 10.4236/eng.2015.76031
Abstract: This work evaluates the performance optimization of heat recovery steam generator system in Afam VI power plant, Rivers State. Nigeria. Steady state monitoring and direct collection of data from the plant was performed including logged data for a period of 12 months. The data were analysed using various energy equations. Hysys software was used to model the temperature across the heating surfaces, and MATLAB software was used to determine the heat transfer coefficient, heat duties, steam flow, effectiveness of the HRSG. The optimization technique was carried out by varying the exhaust gas flow, exhaust gas temperature, steam pressure and the theoretical introduction of duct burner for supplementary firing. The results show that between 490 and 526, the percentage increase in the overall heat absorbed in the HRSG is 37.39%. It also show that for an increase in the exhaust gas mass flow by 80 kg/s, the steam generation increase by 19.29% and 18.18% for the low and high pressure levels respectively. The overall result indicates an improvement in the HRSG energy efficiency and steam generation. As the exhaust gas mass flow and temperature increases, the steam generation and system effectiveness greatly improved under the various considerations, which satisfy the research objective.
Comparative Assessment of Combined-Heat-and-Power Performance of Small-Scale Aero-Derivative Gas Turbine Cycles  [PDF]
Barinyima Nkoi, Barinaadaa Thaddeus Lebele-Alawa
Journal of Power and Energy Engineering (JPEE) , 2015, DOI: 10.4236/jpee.2015.39002
Abstract: This paper considers comparative assessment of combined-heat-and-power (CHP) performance of three small-scale aero-derivative industrial gas turbine cycles in the petrochemical industry. The bulk of supposedly waste exhaust heat associated with gas turbine operation has necessitated the need for CHP application for greater fuel efficiency. This would render gas turbine cycles environ-mentally-friendly, and more economical. However, choosing a particular engine cycle option for small-scale CHP requires information about performances of CHP engine cycle options. The investigation encompasses comparative assessment of simple cycle (SC), recuperated (RC), and intercooled-recuperated (ICR) small-scale aero-derivative industrial gas turbines combined-heat-and-power (SS-ADIGT-CHP). Small-scale ADIGT engines of 1.567 MW derived from helicopter gas turbines are herein analysed in combined-heat-and-power (CHP) application. It was found that in this category of ADIGT engines, better CHP efficiency is exhibited by RC and ICR cycles than SC engine. The CHP efficiencies of RC, ICR, and SC small-scale ADIGT-CHP cycles were found to be 71%, 60%, and 56% respectively. Also, RC engine produces the highest heat recovery steam generator (HRSG) duty. The HRSG duties were found to be 3171.3 kW for RC, 2621.6 kW for ICR, and 3063.1 kW for SC. These outcomes would actually meet the objective of aiding informed preliminary choice of small-scale ADIGT engine cycle options for CHP application.
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