93,666 research outputs found
Efficient Energy Transport in Photosynthesis: Roles of Coherence and Entanglement
Recently it has been discovered---contrary to expectations of physicists as
well as biologists---that the energy transport during photosynthesis, from the
chlorophyll pigment that captures the photon to the reaction centre where
glucose is synthesised from carbon dioxide and water, is highly coherent even
at ambient temperature and in the cellular environment. This process and the
key molecular ingredients that it depends on are described. By looking at the
process from the computer science view-point, we can study what has been
optimised and how. A spatial search algorithmic model based on robust features
of wave dynamics is presented.Comment: 6 pages, 3 figures, to appear in the proceedings of the Symposium "75
Years of Quantum Entanglement: Foundations and Information Theoretic
Applications", January 2011, Kolkata, Indi
Surface-renewal models for heat-transfer between walls and fluidized beds
Two surface-renewed film penetration models describe transient heat-transfer between a wall and a fluidized bed. Methods are presented for estimation of mean residence times of particles at the transporting surface, their age densities and the average transport coefficients
Autonomic computing architecture for SCADA cyber security
Cognitive computing relates to intelligent computing platforms that are based on the disciplines of artificial intelligence, machine learning, and other innovative technologies. These technologies can be used to design systems that mimic the human brain to learn about their environment and can autonomously predict an impending anomalous situation. IBM first used the term ‘Autonomic Computing’ in 2001 to combat the looming complexity crisis (Ganek and Corbi, 2003). The concept has been inspired by the human biological autonomic system. An autonomic system is self-healing, self-regulating, self-optimising and self-protecting (Ganek and Corbi, 2003). Therefore, the system should be able to protect itself against both malicious attacks and unintended mistakes by the operator
Narrating the past: virtual environments and narrative
This paper explores how traditional narrative language used in film and theatre can be adapted to create interactivity and a greater sense of presence in the virtual heritage environment. It focuses on the fundamental principles of narrative required to create immersion and presence and investigates methods of embedding intangible social histories into these environments. These issues are explored in a case study of Greens Mill in the 1830’s, interweaving the story of the reform bill riots in Nottingham with the life of George Green, mathematician and proprietor of the Mill
Eta-nucleon and eta-prime-nucleon coupling constants in QCD and the role of gluons
Coupling constants of and mesons with nucleons have
been calculated using the method of QCD sum rules. Starting from
vacuum-to-meson correlation function of interpolating fields of two nucleons,
its matrix element with respect to nucleon spinors has been considered.
Coupling constants at the physical points have been estimated from
extrapolation of results obtained at two other points. Anomalous glue has been
found to give substantial contribution to the coupling constants and also
accounts for a significant OZI-rule violation.Comment: 6 pages, 3 figures and 2 table
Zariski Closures and Subgroup Separability
The main result of this article is a refinement of the well-known subgroup
separability results of Hall and Scott for free and surface groups. We show
that for any finitely generated subgroup, there is a finite dimensional
representation of the free or surface group that separates the subgroup in the
induced Zariski topology. As a corollary, we establish a polynomial upper bound
on the size of the quotients used to separate a finitely generated subgroup in
a free or surface group.Comment: Final version. To appear in Selecta Mat
Towards Understanding the Origin of Genetic Languages
Molecular biology is a nanotechnology that works--it has worked for billions
of years and in an amazing variety of circumstances. At its core is a system
for acquiring, processing and communicating information that is universal, from
viruses and bacteria to human beings. Advances in genetics and experience in
designing computers have taken us to a stage where we can understand the
optimisation principles at the root of this system, from the availability of
basic building blocks to the execution of tasks. The languages of DNA and
proteins are argued to be the optimal solutions to the information processing
tasks they carry out. The analysis also suggests simpler predecessors to these
languages, and provides fascinating clues about their origin. Obviously, a
comprehensive unraveling of the puzzle of life would have a lot to say about
what we may design or convert ourselves into.Comment: (v1) 33 pages, contributed chapter to "Quantum Aspects of Life",
edited by D. Abbott, P. Davies and A. Pati, (v2) published version with some
editin
- …
