1,240 research outputs found
Consensus with Linear Objective Maps
A consensus system is a linear multi-agent system in which agents communicate
to reach a so-called consensus state, defined as the average of the initial
states of the agents. Consider a more generalized situation in which each agent
is given a positive weight and the consensus state is defined as the weighted
average of the initial conditions. We characterize in this paper the weighted
averages that can be evaluated in a decentralized way by agents communicating
over a directed graph. Specifically, we introduce a linear function, called the
objective map, that defines the desired final state as a function of the
initial states of the agents. We then provide a complete answer to the question
of whether there is a decentralized consensus dynamics over a given digraph
which converges to the final state specified by an objective map. In
particular, we characterize not only the set of objective maps that are
feasible for a given digraph, but also the consensus dynamics that implements
the objective map. In addition, we present a decentralized algorithm to design
the consensus dynamics
Distributed Evaluation and Convergence of Self-Appraisals in Social Networks
We consider in this paper a networked system of opinion dynamics in
continuous time, where the agents are able to evaluate their self-appraisals in
a distributed way. In the model we formulate, the underlying network topology
is described by a rooted digraph. For each ordered pair of agents , we
assign a function of self-appraisal to agent , which measures the level of
importance of agent to agent . Thus, by communicating only with her
neighbors, each agent is able to calculate the difference between her level of
importance to others and others' level of importance to her. The dynamical
system of self-appraisals is then designed to drive these differences to zero.
We show that for almost all initial conditions, the trajectory generated by
this dynamical system asymptotically converges to an equilibrium point which is
exponentially stable
Optimization of corrosion inhibition of essential oils of Alpinia galanga on mild steel using Response Surface Methodology
The use of plant extracts as corrosion inhibitors has gained prominence as replacement for synthetic organic compounds. The plant natural products have been found to be effective, cheap and eco-friendly anticorrosion agents. Corrosion inhibitions of essential oils of Alpinia galanga were investigated on mild steel in hydrochloric acid solution using weight loss method. The interactive effects of inhibitor concentration, temperature and time were optimized for maximum response of inhibition efficiency using Response Surface Methodology with Central Composite Design. The optimum inhibition efficiency of 88.5% at 775 ppm of inhibitor concentration, temperature of 320.4 K and reaction time of 3.75 hours was accomplished. The effectiveness of the inhibitor was also supported using scanning electron microscopy. The mechanism of interaction of both the inhibitor on mild steel surface was found to conform to the Langmuir adsorption isotherm
A note on a gauge-gravity relation and functional determinants
We present a refinement of a recently found gauge-gravity relation between
one-loop effective actions: on the gauge side, for a massive charged scalar in
2d dimensions in a constant maximally symmetric electromagnetic field; on the
gravity side, for a massive spinor in d-dimensional (Euclidean) anti-de Sitter
space. The inclusion of the dimensionally regularized volume of AdS leads to
complete mapping within dimensional regularization. In even-dimensional AdS, we
get a small correction to the original proposal; whereas in odd-dimensional
AdS, the mapping is totally new and subtle, with the `holographic trace
anomaly' playing a crucial role.Comment: 6 pages, io
Pico-hydro electrification from rainwater’s gravitational force for urban area
The demand for electrical energy is increasing in most areas in the world. Unstable fossil fuel price and its rapid depletion have led to an intensive research on new energy source and energy conversion. This paper presents the performance of the energy harvesting which focuses on the experimental work to emulate energy harvesting from the rainwater by utilizing a Pico - hydro approach installed to a high building. NACuM core DB-370F DC generators, 1000 litres water tank, 0.5 inch diameter piping system used in two different configurations with three different head setups. The result shows a huge energy harvesting potential obtained from the system and rainwater with maximum 261 milliwatts despite the hardware’s limitation in the setup. Hance, contributes to the cost-efficient due to its small in size, environmentally friendly, and hassle-free maintenanc
Index Modulation-based Information Harvesting for Far-Field RF Power Transfer
While wireless information transmission (WIT) is evolving into its sixth
generation (6G), maintaining terminal operations that rely on limited battery
capacities has become one of the most paramount challenges for
Internet-of-Things (IoT) platforms. In this respect, there exists a growing
interest in energy harvesting technology from ambient resources, and wireless
power transfer (WPT) can be the key solution towards enabling battery-less
infrastructures referred to as zero-power communication technology. Indeed,
eclectic integration approaches between WPT and WIT mechanisms are becoming a
vital necessity to limit the need for replacing batteries. Beyond the
conventional separation between data and power components of the emitted
waveforms, as in simultaneous wireless information and power transfer (SWIPT)
mechanisms, a novel protocol referred to as information harvesting (IH) has
recently emerged. IH leverages existing WPT mechanisms for data communication
by incorporating index modulation (IM) techniques on top of the existing
far-field power transfer mechanism. In this paper, a unified framework for the
IM-based IH mechanisms has been presented where the feasibility of various IM
techniques are evaluated based on different performance metrics. The presented
results demonstrate the substantial potential to enable data communication
within existing far-field WPT systems, particularly in the context of
next-generation IoT wireless networks.Comment: 13 pages, 9 figure
Chiral Modulations in Curved Space I: Formalism
The goal of this paper is to present a formalism that allows to handle
four-fermion effective theories at finite temperature and density in curved
space. The formalism is based on the use of the effective action and zeta
function regularization, supports the inclusion of inhomogeneous and
anisotropic phases. One of the key points of the method is the use of a
non-perturbative ansatz for the heat-kernel that returns the effective action
in partially resummed form, providing a way to go beyond the approximations
based on the Ginzburg-Landau expansion for the partition function. The
effective action for the case of ultra-static Riemannian spacetimes with
compact spatial section is discussed in general and a series representation,
valid when the chemical potential satisfies a certain constraint, is derived.
To see the formalism at work, we consider the case of static Einstein spaces at
zero chemical potential. Although in this case we expect inhomogeneous phases
to occur only as meta-stable states, the problem is complex enough and allows
to illustrate how to implement numerical studies of inhomogeneous phases in
curved space. Finally, we extend the formalism to include arbitrary chemical
potentials and obtain the analytical continuation of the effective action in
curved space.Comment: 22 pages, 3 figures; version to appear in JHE
The Fine Spectra of the CesĂ ro Operator C 1 over the Sequence Space bvp, (1 ≤ p ∞)
The sequence space bvp consisting of all sequences (xk) such that (xk - xk-1) in the sequence space lp has recently been introduced by Basar and Altay [Ukrainian Math. J. 55(1)(2003), 136-147]; where 1 ≤ p ≤ ∞. In the present paper, the norm of the Cesàro operator C1 acting on the sequence space bvp has been found and the fine spectrum of the Cesàro operator C1 over the sequence space bvp has been determined, where 1 ≤ p < ∞.</p
A Policy Research Method Case-Study: Generating and Extracting Evidence-based Policy Inferences from a large EC Framework Programme Project
In 2004 the European Neighbourhood Policy (ENP) was instituted following the greatest
single enlargement of the European Union (EU), to support security and peaceful relations
between the EU and neighbouring countries with a unified governance approach to economic,
social and political aspects of international cooperation. This paper reports on an effort to
develop and test a methodology for bridging social science research and policy communities
on an important policy question that concerns comity between the EU and its Eurasian,
Middle Eastern and North African neighbouring countries1, although the approach applies to
any broad policy issue for which multiple sources and types of research evidence are present.
Five evaluative elements are developed and implemented whose complementary application
result in a large set of policy inferences, a strategy of implementation, and researcher insights
concerning the method. This case study suggests that the recommended evidence synthesis
methodology has good potential for informing policy that is comprised of multiple elements,
studied by large research teams, and enacted by diverse agents. The suggested methodology
requires engagement by active researchers and policy experts in the formulation of policy
options. It is put forward that improving the quality of evidence-informed policy will depend
upon institutions and practices in the research and policy making communities. (authors' abstract)Series: SRE - Discussion Paper
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