N-body U and K matrix program

Computer program was devised to compute free-fall trajectories of satellites, allowing for injection errors and midcourse velocity perturbations. Program consists of trajectory perturbing program and N-body integrating conic program which can also be used as 2-body patch conic program

Centaur AC-8 Postflight Guidance Analysis

Centaur AC-8 postflight guidance and control analysi

Binomial Ideals and Congruences on Nn

Producción CientíficaA congruence on Nn is an equivalence relation on Nn that is compatible with the additive structure. If k is a field, and I is a binomial ideal in k[X1,…,Xn] (that is, an ideal generated by polynomials with at most two terms), then I induces a congruence on Nn by declaring u and v to be equivalent if there is a linear combination with nonzero coefficients of Xu and Xv that belongs to I. While every congruence on Nn arises this way, this is not a one-to-one correspondence, as many binomial ideals may induce the same congruence. Nevertheless, the link between a binomial ideal and its corresponding congruence is strong, and one may think of congruences as the underlying combinatorial structures of binomial ideals. In the current literature, the theories of binomial ideals and congruences on Nn are developed separately. The aim of this survey paper is to provide a detailed parallel exposition, that provides algebraic intuition for the combinatorial analysis of congruences. For the elaboration of this survey paper, we followed mainly (Kahle and Miller Algebra Number Theory 8(6):1297–1364, 2014) with an eye on Eisenbud and Sturmfels (Duke Math J 84(1):1–45, 1996) and Ojeda and Piedra Sánchez (J Symbolic Comput 30(4):383–400, 2000).National Science Foundation (grant DMS-1500832)Ministerio de Economía, Industria y Competitividad (project MTM2015-65764-C3-1)Junta de Extremadura (grupo de investigación FQM-024

Master of Science

thesisEstablished characteristics of aerated submerged biofilm reactors (ASBRs) include sustenance of multiple microclimates within the system, high biomass accumulation, and highly diverse bacterial population. Besides presenting important advantages over the traditional use of suspended growth activated sludge systems, these properties also make ASBRs a more suitable environment for the achievement of simultaneous carbon, nitrogen and phosphorus removal from sewage. By incorporating air cycling into their operation, simultaneous carbon and nutrient removal employing ASBRs has been well established and documented. Airon and air-off intervals promote the coexistence of aerobic, anoxic and anaerobic zones within the system, allowing the concurrentbiological metabolization of carbon, nitrogen, and phosphorus compounds. This research assessed the simultaneous carbon and nutrient removal potential of specially designed structures treating primary clarified municipal wastewater effluent at low temperatures. For this, two pilot-scale bioreactors were constructed and operated during 115. One bioreactor held a series of six dome shaped aerated submerged biofilm devices, called Poo-Gloos, while the second bioreactor held a series of six aeration bases, intended to emulate a controlling suspended growth process. With both bioreactors receiving the exact same influent wastewater constitution and flow rate, and with operational variables adjusted equally to both reactors on a weekly basis, a quantitative, qualitative and comparative analysis of the nutrient removal capacity of the two systems was performed. In terms of COD removal, average weekly percentage removals of up to 77±5% and as low as 50±5% were achieved by the Poo-Gloo system under air cycling conditions. In contrast, the control system exhibited an average weekly removal percentage range between 8±8% and 39±6%. In terms of total nitrogen (TN) removal, a consistent increase in average weekly removal percentages from 42±6% to 47±3%, and to 49±4% was observed in the case of the Poo-Gloo system conforming air-off periods were increased from 2 hours to 3 hours, and to 4 hours, respectively. In contrast, the control system exhibited an erratic behavior under air cycling conditions achieving weekly percentage removals in the range between -7±13% and 14±5%. Finally, in terms of total phosphorus (TP) removal, an optimum air cycling composition of 21 hours on/3 hours off was observed, allowing for the largest average weekly TP percentage removal achieved, 22±4%. Meanwhile, the control system accomplished an average weekly removal percentage of only 0 ±6% under the same air cycling conditions

Affine semigroups having a unique Betti element

We characterize affine semigroups having one Betti element and we compute some relevant non-unique factorization invariants for these semigroups. As an example, we particularize our description to numerical semigroups.Comment: 8 pages, 1 figure. To appear in Journal of Algebra and its Application

Optimal Ecodriving Control: Energy-Efficient Driving of Road Vehicles as an Optimal Control Problem

International audienceTransportation is responsible for a substantial fraction of worldwide energy consumption and greenhouse gas emissions and is the largest sector after energy production. However, while emissions from other sectors are generally decreasing, those from transportation have increased since 1990. Reducing the impact of transportation is a task that is inherently associated with the improvement of energy efficiency, particularly for passenger cars that contribute to almost half of the whole sector

Hilbert number for a family of piecewise nonautonomous equations

For family $x'=(a_0+a_1\cos t+a_2 \sin t)|x|+b_0+b_1 \cos t+b_2 \sin t$, we solve three basic problems related with its dynamics. First, we characterize when it has a center (Poincar\'e center focus problem). Second, we show that each equation has a finite number of limit cycles (finiteness problem), and finally we give a uniform upper bound for the number of limit cycles (Hilbert's 16th problem).Comment: 16 pages, no figure