11,972 research outputs found
Changemaker values within the Foundation Degree Learning and Teaching and the development of a Teaching Assistant Teachmeet Event
An article exploring the Changemaker values within the planning and delivery of the TeachMeet for teaching Assistants event
A Parametric Non-Convex Decomposition Algorithm for Real-Time and Distributed NMPC
A novel decomposition scheme to solve parametric non-convex programs as they
arise in Nonlinear Model Predictive Control (NMPC) is presented. It consists of
a fixed number of alternating proximal gradient steps and a dual update per
time step. Hence, the proposed approach is attractive in a real-time
distributed context. Assuming that the Nonlinear Program (NLP) is
semi-algebraic and that its critical points are strongly regular, contraction
of the sequence of primal-dual iterates is proven, implying stability of the
sub-optimality error, under some mild assumptions. Moreover, it is shown that
the performance of the optimality-tracking scheme can be enhanced via a
continuation technique. The efficacy of the proposed decomposition method is
demonstrated by solving a centralised NMPC problem to control a DC motor and a
distributed NMPC program for collaborative tracking of unicycles, both within a
real-time framework. Furthermore, an analysis of the sub-optimality error as a
function of the sampling period is proposed given a fixed computational power.Comment: 16 pages, 9 figure
An Alternating Trust Region Algorithm for Distributed Linearly Constrained Nonlinear Programs, Application to the AC Optimal Power Flow
A novel trust region method for solving linearly constrained nonlinear
programs is presented. The proposed technique is amenable to a distributed
implementation, as its salient ingredient is an alternating projected gradient
sweep in place of the Cauchy point computation. It is proven that the algorithm
yields a sequence that globally converges to a critical point. As a result of
some changes to the standard trust region method, namely a proximal
regularisation of the trust region subproblem, it is shown that the local
convergence rate is linear with an arbitrarily small ratio. Thus, convergence
is locally almost superlinear, under standard regularity assumptions. The
proposed method is successfully applied to compute local solutions to
alternating current optimal power flow problems in transmission and
distribution networks. Moreover, the new mechanism for computing a Cauchy point
compares favourably against the standard projected search as for its activity
detection properties
A Parametric Multi-Convex Splitting Technique with Application to Real-Time NMPC
A novel splitting scheme to solve parametric multiconvex programs is
presented. It consists of a fixed number of proximal alternating minimisations
and a dual update per time step, which makes it attractive in a real-time
Nonlinear Model Predictive Control (NMPC) framework and for distributed
computing environments. Assuming that the parametric program is semi-algebraic
and that its KKT points are strongly regular, a contraction estimate is derived
and it is proven that the sub-optimality error remains stable if two key
parameters are tuned properly. Efficacy of the method is demonstrated by
solving a bilinear NMPC problem to control a DC motor.Comment: To appear in Proceedings of the 53rd IEEE Conference on Decision and
Control 201
Tools and technologies in mathematical didactics
This short paper provides an overview of recent European research about the use and impact of tools and technologies in mathematical didactics. Such research is categorised as focusing on theoretical ideas, on algebraic knowledge when using spreadsheet and computer algebra (CAS), and on dynamic geometry software (DGS). The paper reveals the variety of software technologies, education levels, and methodologies utitised in European research
Toward a zero carbon energy policy in Europe: Defining a feasible and viable solution.
Reducing the European Union GHG emissions by at least 80% by 2050 will require a near zero carbon electricity, road and rail transport industry, and heating and cooling in buildings. As compared to "business as usual" the amount of energy required will basically vary according to the level of energy efficiency: it is the "system scale". Then it is the "system design" which will provide the needed carbon-free technologies consisting of renewable, nuclear and fossil fuels with carbon capture and storage. . A zero carbon energy system by 2050 is then demonstrated to be feasible. However it is far from easy and requires immediate and substantial policy action. The main policy implications are addressed in this paper. The 5 years 2010-2015 will be decisive in establishing a regulatory environment whereby the EU will be in a position, by 2020, to take the next steps to achieve the 2050 goal..EU Energy Policy; Emission Rights; Carbon free electricity production; regulation of electricity industry
ER5, a tomato cDNA encoding an ethylene-responsive LEA-like protein: characterization and expression in response to drought, ABA and wounding
We report the isolation by differential display of a novel tomato ethylene-responsive cDNA, designated ER5.
RT-PCR analysis of ER5 expression revealed an early (15 min) and transient induction by ethylene in tomato fruit,
leaves and roots. ER5 mRNA accumulated during 2 h of ethylene treatment and thereafter underwent a dramatic
decline leading to undetectable expression after 5 h of treatment. The full-length cDNA clone of 748 bp was
obtained and DNA sequence analysis showed strong homologies to members of the atypical hydrophobic group of
the LEA protein family. The predicted amino acid sequence shows 67%, 64%, 64%, and 61%sequence identity with
the tomato Lemmi9, soybean D95-4, cotton Lea14-A, and resurrection plant pcC27-45 gene products, respectively.
As with the other members of this group, ER5 encodes a predominantly hydrophobic protein. Prolonged drought
stress stimulates ER5 expression in leaves and roots, while ABA induction of this ethylene-responsive clone is
confined to the leaves. The use of 1-MCP, an inhibitor of ethylene action, indicates that the drought induction of
ER5 is ethylene-mediated in tomato roots. Finally, wounding stimulates ER5 mRNA accumulation in leaves and
roots. Among the Lea gene family this novel clone is the first to display an ethylene-regulated expression
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