227,421 research outputs found
Full-field interferometry using infinity corrected optics
In this paper the construction of full-field (imaging) interferometers using infinity corrected
optics commonly used in microscopy is discussed, with an emphasis on self-mixing
interferometry configurations where the imaged light field is mixed with itself rather than
a reference wave. Such configurations are used in speckle shearing interferometry, flow
visualisation and quantitative flow measurement. The critical considerations for constructing
path-length imbalanced full-field interferometers for these and similar applications are
discussed, expressions are derived for key calculations and interferograms from example
interferometers are presented. These include the concept of balancing the infinity-spaces of
the two arms via the use of a glass block to minimise the optical path difference variation
across the interferogram and ensure adequate sampling of the fringes on the detector. Further,
the use of tilted glass blocks in single-pass and double-pass arrangements is detailed for
the generation and control of spatial carrier fringes without extensive realignment of the
interferometer, and for phase shifting
Channel characterization for 1D molecular communication with two absorbing receivers
This letter develops a one-dimensional (1D) diffusion-based molecular communication system to analyze channel responses between a single transmitter (TX) and two fully-absorbing receivers (RXs). Incorporating molecular degradation in the environment, rigorous analytical formulas for i) the fraction of molecules absorbed, ii) the corresponding hitting rate, and iii) the asymptotic fraction of absorbed molecules as time approaches infinity at each RX are derived when an impulse of molecules are released at the TX. By using particle-based simulations, the derived analytical expressions are validated. Simulations also present the distance ranges of two RXs that do not impact molecular absorption of each other, and demonstrate that the mutual influence of two active RXs reduces with the increase in the degradation rate
On sets of terms with a given intersection type
We are interested in how much of the structure of a strongly normalizable
lambda term is captured by its intersection types and how much all the terms of
a given type have in common. In this note we consider the theory BCD
(Barendregt, Coppo, and Dezani) of intersection types without the top element.
We show: for each strongly normalizable lambda term M, with beta-eta normal
form N, there exists an intersection type A such that, in BCD, N is the unique
beta-eta normal term of type A. A similar result holds for finite sets of
strongly normalizable terms for each intersection type A if the set of all
closed terms M such that, in BCD, M has type A, is infinite then, when closed
under beta-eta conversion, this set forms an adaquate numeral system for
untyped lambda calculus. A number of related results are also proved
One-parameter extension of the Doi-Peliti formalism and relation with orthogonal polynomials
An extension of the Doi-Peliti formalism for stochastic chemical kinetics is
proposed. Using the extension, path-integral expressions consistent with
previous studies are obtained. In addition, the extended formalism is naturally
connected to orthogonal polynomials. We show that two different orthogonal
polynomials, i.e., Charlier polynomials and Hermite polynomials, can be used to
express the Doi-Peliti formalism explicitly.Comment: 10 page
Towards a Nonequilibrium Quantum Field Theory Approach to Electroweak Baryogenesis
We propose a general method to compute -violating observables from
extensions of the standard model in the context of electroweak baryogenesis. It
is alternative to the one recently developed by Huet and Nelson and relies on a
nonequilibrium quantum field theory approach. The method is valid for all
shapes and sizes of the bubble wall expanding in the thermal bath during a
first-order electroweak phase transition. The quantum physics of -violation
and its suppression coming from the incoherent nature of thermal processes are
also made explicit.Comment: 19 pages, 1 figure available upon e-mail reques
Implementation of Time-Delay Interferometry for LISA
We discuss the baseline optical configuration for the Laser Interferometer
Space Antenna (LISA) mission, in which the lasers are not free-running, but
rather one of them is used as the main frequency reference generator (the {\it
master}) and the remaining five as {\it slaves}, these being phase-locked to
the master (the {\it master-slave configuration}). Under the condition that the
frequency fluctuations due to the optical transponders can be made negligible
with respect to the secondary LISA noise sources (mainly proof-mass and shot
noises), we show that the entire space of interferometric combinations LISA can
generate when operated with six independent lasers (the {\it one-way method})
can also be constructed with the {\it master-slave} system design. The
corresponding hardware trade-off analysis for these two optical designs is
presented, which indicates that the two sets of systems needed for implementing
the {\it one-way method}, and the {\it master-slave configuration}, are
essentially identical. Either operational mode could therefore be implemented
without major implications on the hardware configuration. We then.......Comment: 39 pages, 6 figures, 2 table
Rich Counter-Examples for Temporal-Epistemic Logic Model Checking
Model checking verifies that a model of a system satisfies a given property,
and otherwise produces a counter-example explaining the violation. The verified
properties are formally expressed in temporal logics. Some temporal logics,
such as CTL, are branching: they allow to express facts about the whole
computation tree of the model, rather than on each single linear computation.
This branching aspect is even more critical when dealing with multi-modal
logics, i.e. logics expressing facts about systems with several transition
relations. A prominent example is CTLK, a logic that reasons about temporal and
epistemic properties of multi-agent systems. In general, model checkers produce
linear counter-examples for failed properties, composed of a single computation
path of the model. But some branching properties are only poorly and partially
explained by a linear counter-example.
This paper proposes richer counter-example structures called tree-like
annotated counter-examples (TLACEs), for properties in Action-Restricted CTL
(ARCTL), an extension of CTL quantifying paths restricted in terms of actions
labeling transitions of the model. These counter-examples have a branching
structure that supports more complete description of property violations.
Elements of these counter-examples are annotated with parts of the property to
give a better understanding of their structure. Visualization and browsing of
these richer counter-examples become a critical issue, as the number of
branches and states can grow exponentially for deeply-nested properties.
This paper formally defines the structure of TLACEs, characterizes adequate
counter-examples w.r.t. models and failed properties, and gives a generation
algorithm for ARCTL properties. It also illustrates the approach with examples
in CTLK, using a reduction of CTLK to ARCTL. The proposed approach has been
implemented, first by extending the NuSMV model checker to generate and export
branching counter-examples, secondly by providing an interactive graphical
interface to visualize and browse them.Comment: In Proceedings IWIGP 2012, arXiv:1202.422
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