4,677 research outputs found
Entanglement between an electron and a nuclear spin 1/2
We report on the preparation and detection of entangled states between an
electron spin 1/2 and a nuclear spin 1/2 in a molecular single crystal. These
were created by applying pulses at ESR (9.5 GHz) and NMR (28 MHz) frequencies.
Entanglement was detected by using a special entanglement detector sequence
based on a unitary back transformation including phase rotation.Comment: 4 pages, 3 figure
Swarm shape manipulation through connection control
The control of a large swarm of distributed agents is a well known challenge within the study of unmanned autonomous systems. However, it also presents many new opportunities. The advantages of operating a swarm through distributed means has been assessed in the literature for efficiency from both operational and economical aspects; practically as the number of agents increases, distributed control is favoured over centralised control, as it can reduce agent computational costs and increase robustness on the swarm. Distributed architectures, however, can present the drawback of requiring knowledge of the whole swarm state, therefore limiting the scalability of the swarm. In this paper a strategy is presented to address the challenges of distributed architectures, changing the way in which the swarm shape is controlled and providing a step towards verifiable swarm behaviour, achieving new configurations, while saving communication and computation resources. Instead of applying change at agent level (e.g. modify its guidance law), the sensing of the agents is addressed to a portion of agents, differentially driving their behaviour. This strategy is applied for swarms controlled by artificial potential functions which would ordinarily require global knowledge and all-to-all interactions. Limiting the agents' knowledge is proposed for the first time in this work as a methodology rather than obstacle to obtain desired swarm behaviour
A non-partitionable Cohen-Macaulay simplicial complex
A long-standing conjecture of Stanley states that every Cohen-Macaulay
simplicial complex is partitionable. We disprove the conjecture by constructing
an explicit counterexample. Due to a result of Herzog, Jahan and Yassemi, our
construction also disproves the conjecture that the Stanley depth of a monomial
ideal is always at least its depth.Comment: Final version. 13 pages, 2 figure
Thermal efficiency analysis of buildings with phase change materials.
Increasing global temperature is alarming the need for construction industry to have thermally efficient building materials. Incorporating Phase Change Materials (PCM) in buildings is widely accepted method for reduction in temperature, thereby achieving better thermal efficiency. This paper focuses on the assessment of thermal performance of PCM-incorporated building under tropical climatic condition. The simulation process was carried out using Design Builder Software and the developed building model is validated with the results available in the literature. A parametric study is also performed in order to identify the effect of different parameters like building orientation, window to wall ratio, ceiling height and construction material on the indoor air temperature. The results showed that the maximum reduction was up to 2.76°C.
Keywords- Thermal Efficiency, Tropical climate, PC
Geometry of the 3-Qubit State, Entanglement and Division Algebras
We present a generalization to 3-qubits of the standard Bloch sphere
representation for a single qubit and of the 7-dimensional sphere
representation for 2 qubits presented in Mosseri {\it et
al.}\cite{Mosseri2001}. The Hilbert space of the 3-qubit system is the
15-dimensional sphere , which allows for a natural (last) Hopf
fibration with as base and as fiber. A striking feature is, as in
the case of 1 and 2 qubits, that the map is entanglement sensitive, and the two
distinct ways of un-entangling 3 qubits are naturally related to the Hopf map.
We define a quantity that measures the degree of entanglement of the 3-qubit
state. Conjectures on the possibility to generalize the construction for higher
qubit states are also discussed.Comment: 12 pages, 2 figures, final versio
Amino acid substitution during functionally constrained divergent evolution of protein sequences
In aligning homologous protein sequences, it is generally assumed that amino acid substitutions subsequent in time occur independently of amino acid substitutions previous in time, i.e. that patterns of mulation are similar at low and high sequence divergence. This assumption is examined here and shown to be incorrect in an interesting way. Separate mutation matrices were constructed for aligned protein sequence pairs at divergences ranging from 5 to 100 PAM units (point accepted mutations per 100 aligned positions). From these, the corresponding log-odds (Day-hoff) matrices, normalized to 250 PAM units, were constructed. The matrices show that the genetic code influences accepted point mutations strongly at early stages of divergence, while the chemical properties of the side chains dominate at more advanced stage
Present status of perch fishery resources in India and its prospects
The perch resources and fisheries In India have been dealt with. As seen from the statewise
perch production during 1969-19Q1, on an average 27,184 tonnes of parches were landed in India
with fluctuation from 12,865 In 1969 to 49,312 in 1978. The gearwise and statewise perch
production from 1982-83 to 1984-85 indicates that the mechanised units contributed 72.4 % and nonmechanised
27.6 %. Among mechanised units, the trawlers have landed the major portion of the catch
(68 4 % ) . The State wise species composition of perch landings indicate that the threadtin breams
formed more than 50% of the catch- During 1982-83 and 1S83-84. the perch production of Tamil
Nadu was higher than all other states whereas during 1984 85, Kerala was the first in perch production
followed by Andhrapradesh and Tamil Nadu- The different groups of perches landed by trawl and gill
net units at different important landing centres on the east and west coast of Indian show that in all
the centres the catch rates of trawlers were higher. The higher catch rate in trawl net operations In
Sasoons Dock and New ferry Wharf was due to voyage fishing for more than a da
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