2,159 research outputs found
Carbon Trading with Blockchain
Blockchain has the potential to accelerate the deployment of emissions
trading systems (ETS) worldwide and improve upon the efficiency of existing
systems. In this paper, we present a model for a permissioned blockchain
implementation based on the successful European Union (EU) ETS and discuss its
potential advantages over existing technology. We propose an ETS model that is
both backwards compatible and future-proof, characterised by
interconnectedness, transparency, tamper-resistance and high liquidity.
Further, we identify key challenges to implementation of a blockchain ETS, as
well as areas of future work required to enable a fully-decentralised
blockchain ETS
The Analysis of Large Order Bessel Functions in Gravitational Wave Signals from Pulsars
In this work, we present the analytic treatment of the large order Bessel
functions that arise in the Fourier Transform (FT) of the Gravitational Wave
(GW) signal from a pulsar. We outline several strategies which employ
asymptotic expansions in evaluation of such Bessel functions which also happen
to have large argument. Large order Bessel functions also arise in the
Peters-Mathews model of binary inspiralling stars emitting GW and several
problems in potential scattering theory. Other applications also arise in a
variety of problems in Applied Mathematics as well as in the Natural Sciences
and present a challenge for High Performance Computing(HPC).Comment: 8 pages, Uses IEEE style files: Ieee.cls, Ieee.clo and floatsty.sty.
Accepted for publication in High Performance Computing Symposium, May 15-18
(HPCS 2005) Guelph, Ontario, Canad
Pseudo-finite hard instances for a student-teacher game with a Nisan-Wigderson generator
For an NP intersect coNP function g of the Nisan-Wigderson type and a string
b outside its range we consider a two player game on a common input a to the
function. One player, a computationally limited Student, tries to find a bit of
g(a) that differs from the corresponding bit of b. He can query a
computationally unlimited Teacher for the witnesses of the values of constantly
many bits of g(a). The Student computes the queries from a and from Teacher's
answers to his previous queries. It was proved by Krajicek (2011) that if g is
based on a hard bit of a one-way permutation then no Student computed by a
polynomial size circuit can succeed on all a. In this paper we give a lower
bound on the number of inputs a any such Student must fail on. Using that we
show that there is a pseudo-finite set of hard instances on which all uniform
students must fail. The hard-core set is defined in a non-standard model of
true arithmetic and has applications in a forcing construction relevant to
proof complexity
Poland, the Netherlands and the EU - Common Challenges
Leiden Europa Lecture delivered by Minister R. Sikorski at Leiden University on 12 June 2013
ALL EXTER
The extension problem for partial Boolean structures in Quantum Mechanics
Alternative partial Boolean structures, implicit in the discussion of
classical representability of sets of quantum mechanical predictions, are
characterized, with definite general conclusions on the equivalence of the
approaches going back to Bell and Kochen-Specker. An algebraic approach is
presented, allowing for a discussion of partial classical extension, amounting
to reduction of the number of contexts, classical representability arising as a
special case. As a result, known techniques are generalized and some of the
associated computational difficulties overcome. The implications on the
discussion of Boole-Bell inequalities are indicated.Comment: A number of misprints have been corrected and some terminology
changed in order to avoid possible ambiguitie
Quasi-Monte Carlo, Monte Carlo, and regularized gradient optimization methods for source characterization of atmospheric releases
An inversion technique based on MC/QMC search and regularized gradient optimization was developed to solve the atmospheric source characterization problem. The Gaussian Plume Model was adopted as the forward operator and QMC/MC search was implemented in order to find good starting points for the gradient optimization. This approach was validated on the Copenhagen Tracer Experiments. The QMC approach with the utilization of clasical and scrambled Halton, Hammersley and Sobol points was shown to be 10-100 times more efficient than the Mersenne Twister Monte Carlo generator. Further experiments are needed for different data sets. Computational complexity analysis needs to be
carried out
Anatomy of Malicious Singularities
As well known, the b-boundaries of the closed Friedman world model and of
Schwarzschild solution consist of a single point. We study this phenomenon in a
broader context of differential and structured spaces. We show that it is an
equivalence relation , defined on the Cauchy completed total space
of the frame bundle over a given space-time, that is responsible for
this pathology. A singularity is called malicious if the equivalence class
related to the singularity remains in close contact with all other
equivalence classes, i.e., if for every . We
formulate conditions for which such a situation occurs. The differential
structure of any space-time with malicious singularities consists only of
constant functions which means that, from the topological point of view,
everything collapses to a single point. It was noncommutative geometry that was
especially devised to deal with such situations. A noncommutative algebra on
, which turns out to be a von Neumann algebra of random operators,
allows us to study probabilistic properties (in a generalized sense) of
malicious singularities. Our main result is that, in the noncommutative regime,
even the strongest singularities are probabilistically irrelevant.Comment: 16 pages in LaTe
A Simple Laboratory Experiment for the Measurement of Single Phase Permeability
A simple experiment for measuring single-phase permeability of fully saturated porous medium is introduced. The experiment utilizes radial flow of a non-volatile wetting fluid through a porous medium such as ceramic tile, concrete or sand. The radial position of flow front is measured as a function of time and the collected data are analyzed using Darcy\u27s Law to determine the permeability. In addition, the phenomenon of the multiphase flow through the medium with a broad pore size distribution is demonstrated
Classroom culture and indigenous classrooms
Thesis (M.Ed.) University of Alaska Fairbanks, 2008"Indigenous languages have been traditionally learned by doing activities on the land, with the family or around a village. Sometimes, because this is not feasible, Indigenous languages can be learned in a classroom. This is a qualitative research on the author's own Indigenous language classroom with the theoretical foundations of second language acquisition and group formation processes. Data collected were videotapes, audiotapes, student journals, and an exit interview, which were triangulated and verified by an interrater. Results were that the instructor had to possess a philosophy of second language teaching and learning; set high expectations, and create a positive classroom culture. Learners had to be extremely motivated; participate, and pull their own weight. The overall recommendations are that (a) learners need to learn their ancestral language as a second language, (b) Native language teachers need training on theories of second language acquisition, (c) Native language teachers need to have a strong philosophy of second language learning and teaching, and (d) learners need to have a mindset that they will learn to speak their ancestral languages by practicing. These recommendations have worked in the researcher's classroom, and can be extended to any second language teaching or learning arena"--Leaf ii
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