8,546 research outputs found
Sequential evacuation strategy for multiple rooms toward the same means of egress
This paper examines different evacuation strategies for systems where several
rooms evacuate trough the same means of egress, using microscopic pedestrian
simulation.As a case study, a medium-rise office building is considered. It was
found that the standard strategy, whereby the simultaneous evacuation of all
levels is performed, can be improved by a sequential evacuation, beginning with
the lowest floor and continuing successively with each one of the upper floors
after a certain delay. The importance of the present research is that it
provides the basis for the design and implementation of new evacuation
strategies and alarm systems that could significantly improve the evacuation of
multiple rooms trough a common means of escape.Comment: 8 pages, 4 figure
Dual-use Molecules from Yeast
This year the OPCW, the implementing body for the Chemical Weapons Convention, celebrates the 20th anniversary of entry into forces. In 2014, this organization examined the impact of new technologies in the field of chemical and biological weapons, in particular the “Convergence” of Chemistry and Biology. An OPCW report of the Scientific Advisory Group highlighted the importance of monitoring developments in science and technology: “New production processes, combined with developments in drug discovery and delivery, could be exploited in the development of new toxic chemicals that could be used as weapons.” 1 Indeed, since 2008, Synthetic Biology is monitored also by other international organizations, such as the Nonproliferation Export Control Regimes Australia Group
A MULTICROP PRODUCTION MODEL OF IRRIGATED AGRICULTURE, APPLIED TO WATER ALLOCATION POLICY OF THE BUREAU OF RECLAMATION
Recipients of irrigation water from the Bureau of Reclamation (BuRec) face a future of water conservation. By formally modeling surface water as a fixed, allocatable input to a multioutput firm, this research captures the institutional constraints governing water allocation and , simultaneously, establishes a cohesive approach to analyzing the production effects of BuRec allocation policy. Econometric results show that BuRec-served irrigators'Â’ crop supply and land allocation decisions are generally inelastic with respect to the water constraint. Using the elasticities, a policy simulation of a 10% reduction in BuRec water allocation indicates that production response to reduced water supply would affect the national price of three of ten major crops produced by BuRec-served farms.Resource /Energy Economics and Policy,
Rain estimation from satellites: An examination of the Griffith-Woodley technique
The Griffith-Woodley Technique (GWT) is an approach to estimating precipitation using infrared observations of clouds from geosynchronous satellites. It is examined in three ways: an analysis of the terms in the GWT equations; a case study of infrared imagery portraying convective development over Florida; and the comparison of a simplified equation set and resultant rain map to results using the GWT. The objective is to determine the dominant factors in the calculation of GWT rain estimates. Analysis of a single day's convection over Florida produced a number of significant insights into various terms in the GWT rainfall equations. Due to the definition of clouds by a threshold isotherm the majority of clouds on this day did not go through an idealized life cycle before losing their identity through merger, splitting, etc. As a result, 85% of the clouds had a defined life of 0.5 or 1 h. For these clouds the terms in the GWT which are dependent on cloud life history become essentially constant. The empirically derived ratio of radar echo area to cloud area is given a singular value (0.02) for 43% of the sample, while the rainrate term is 20.7 mmh-1 for 61% of the sample. For 55% of the sampled clouds the temperature weighting term is identically 1.0. Cloud area itself is highly correlated (r=0.88) with GWT computed rain volume. An important, discriminating parameter in the GWT is the temperature defining the coldest 10% cloud area. The analysis further shows that the two dominant parameters in rainfall estimation are the existence of cold cloud and the duration of cloud over a point
Native state of natural proteins optimizes local entropy
The differing ability of polypeptide conformations to act as the native state of proteins has long been rationalized in terms of differing kinetic accessibility or thermodynamic stability. Building on the successful applications of physical concepts and sampling algorithms recently introduced in the study of disordered systems, in particular artificial neural networks, we quantitatively explore how well a quantity known as the local entropy describes the native state of model proteins. In lattice models and all-atom representations of proteins, we are able to efficiently sample high local entropy states and to provide a proof of concept of enhanced stability and folding rate. Our methods are based on simple and general statistical-mechanics arguments, and thus we expect that they are of very general use
From Display to Labelled Proofs for Tense Logics
We introduce an effective translation from proofs in the display calculus to proofs in the labelled calculus in the context of tense logics. We identify the labelled calculus proofs in the image of this translation as those built from labelled sequents whose underlying directed graph possesses certain properties. For the basic normal tense logic Kt, the image is shown to be the set of all proofs in the labelled calculus G3Kt
Proving Craig and Lyndon Interpolation Using Labelled Sequent Calculi
We have recently presented a general method of proving the fundamental
logical properties of Craig and Lyndon Interpolation (IPs) by induction on
derivations in a wide class of internal sequent calculi, including sequents,
hypersequents, and nested sequents. Here we adapt the method to a more general
external formalism of labelled sequents and provide sufficient criteria on the
Kripke-frame characterization of a logic that guarantee the IPs. In particular,
we show that classes of frames definable by quantifier-free Horn formulas
correspond to logics with the IPs. These criteria capture the modal cube and
the infinite family of transitive Geach logics
European specific landrace conservation strategy for target crops (Avena, Beta, Brassica and Medicago)
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