14,737 research outputs found
Modeling rationality to control self-organization of crowds: An environmental approach
In this paper we propose a classification of crowd models in built
environments based on the assumed pedestrian ability to foresee the movements
of other walkers. At the same time, we introduce a new family of macroscopic
models, which make it possible to tune the degree of predictiveness (i.e.,
rationality) of the individuals. By means of these models we describe both the
natural behavior of pedestrians, i.e., their expected behavior according to
their real limited predictive ability, and a target behavior, i.e., a
particularly efficient behavior one would like them to assume (for, e.g.,
logistic or safety reasons). Then we tackle a challenging shape optimization
problem, which consists in controlling the environment in such a way that the
natural behavior is as close as possible to the target one, thereby inducing
pedestrians to behave more rationally than what they would naturally do. We
present numerical tests which elucidate the role of rational/predictive
abilities and show some promising results about the shape optimization problem
Does financial development cause economic growth in the ASEAN-4 countries
This paper empirically examines the short- and long-run finance-growth nexus during the post-1997 financial crisis in the ASEAN-4 countries (i.e., Indonesia,Malaysia, Thailand and the Philippines) by employing battery of times series techniques such as autoregressive distributed lag (ARDL) model, vector error correction model (VECM), variance decompositions (VDCs) and impulseresponse
functions (IRFs). Based on the ARDL models, the study documents a long-run equilibrium between economic growth, finance depth, share of investment and inflation. The study also finds that the common sources of economic progress/regress among the countries are price stability and financial development. Granger causality tests based on the VECM further reveals that there are: (i) no causality between finance-growth in Indonesia; the finding in
favour of “the independent hypothesis” of Lucas (1988); (ii) a unidirectional causality running from finance to growth in Malaysia, thus supporting “the
finance-growth led hypothesis” or “the supply-leading view”; (iii) a bidirectional causality between finance-growth in Thailand, the finding accords with “the feedback hypothesis” or “bidirectional causality view”; and (iv) a
unidirectional causality stemming from growth to finance in the Philippines, the finding echoes with “the growth-led finance hypothesis” or “the demand following view” of Robinson (1952). Based on the VDCs and IRFs, the study
discovers that the variations in the economic growth rely very much on its own innovations. If policy makers want to promote growth in the ASEAN-4 countries, priority should be given for long run policies, i.e., the enhancement of existing financial institutions both in the banking sector and stock market
MHD Modeling for Formation Process of Coronal Mass Ejections: Interaction between Ejecting Flux Rope and Ambient Field
We performed magnetohydrodynamic simulation of a formation process of coronal
mass ejections (CMEs), focusing on interaction (reconnection) between an
ejecting flux rope and its ambient field. We examined three cases with
different ambient fields: no ambient field, and cases with dipole field of two
opposite directions which are parallel and anti-parallel to that of the flux
rope surface. As a result, while the flux rope disappears in the anti-parallel
case, in other cases the flux ropes can evolve to CMEs and show different
amounts of rotation of the flux rope. The results imply that the interaction
between an ejecting flux rope and its ambient field is an important process for
determining CME formation and CME orientation, and also show that the amount
and direction of magnetic flux within the flux rope and the ambient field are
key parameters for CME formation. Especially, the interaction (reconnection)
plays a significant role to the rotation of the flux rope, with a process
similar to "tilting instability" in a spheromak-type experiment of laboratory
plasma.Comment: 24 pages, 5 figures. Accepted for publication in Ap
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