58 research outputs found
Pursuit on a Graph Using Partial Information
The optimal control of a "blind" pursuer searching for an evader moving on a
road network and heading at a known speed toward a set of goal vertices is
considered. To aid the "blind" pursuer, certain roads in the network have been
instrumented with Unattended Ground Sensors (UGSs) that detect the evader's
passage. When the pursuer arrives at an instrumented node, the UGS therein
informs the pursuer if and when the evader visited the node. The pursuer's
motion is not restricted to the road network. In addition, the pursuer can
choose to wait/loiter for an arbitrary time at any UGS location/node. At time
0, the evader passes by an entry node on his way towards one of the exit nodes.
The pursuer also arrives at this entry node after some delay and is thus
informed about the presence of the intruder/evader in the network, whereupon
the chase is on - the pursuer is tasked with capturing the evader. Because the
pursuer is "blind", capture entails the pursuer and evader being collocated at
an UGS location. If this happens, the UGS is triggered and this information is
instantaneously relayed to the pursuer, thereby enabling capture. On the other
hand, if the evader reaches one of the exit nodes without being captured, he is
deemed to have escaped. We provide an algorithm that computes the maximum
initial delay at the entry node for which capture is guaranteed. The algorithm
also returns the corresponding optimal pursuit policy
SÃntese e caracterização de ferritas de Zn e Mn provenientes de pilhas inutilizadas
Synthesizing capabilities for collective adaptive systems from self-descriptive hardware devices bridging the reality gap
Kinetics and Mechanism of Oxidation of Tryptophan by Ferrate(VI)
Kinetics
of the oxidation of tryptophan (Trp) and kynurenine (Kyn),
precursors of nitrogenous disinfection byproducts (N-DBP), by ferrateÂ(VI)
(Fe<sup>VI</sup>O<sub>4</sub><sup>2–</sup>, FeÂ(VI)) were investigated
over the acidic to basic pH range. The second-order rate constants
decreased with increase in pH, which could be described by the speciation
of FeÂ(VI) and Trp (or Kyn). The trend of pH dependence of rates for
Trp (i.e., aromatic α-amino acid) differs from that for glycine
(i.e., aliphatic α-amino acid). A nonlinear relationship between
transformation of Trp and the added amount of FeÂ(VI) was found. This
suggests that the formed intermediate oxidized products (OPs), identified
by LC-PDA and LC-MS techniques, could possibly compete with Trp to
react with FeÂ(VI). <i>N</i>-Formylkynurenine (NFK) at pH
7.0 and 4-hydroxyquinoline (4-OH Q) and kynurenic acid (Kyn-A) at
pH 9.0 were the major OPs. Tryptophan radical formation during the
reaction was confirmed by the rapid-freeze quench EPR experiments.
The oxygen atom transfer from FeÂ(VI) to NFK was demonstrated by reacting
Fe<sup>18</sup>O<sub>4</sub><sup>2–</sup> ion with Trp. A proposed
mechanism explains the identified OPs at both neutral and alkaline
pH. Kinetics and OPs by FeÂ(VI) were compared with other oxidants (chlorine,
ClO<sub>2</sub><sup>•</sup>, O<sub>3</sub>, and <sup>•</sup>OH)
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