1,720,963 research outputs found
Gradient-based Instantaneous Traffic Flow Optimization on a Roundabout
No full textIn this article we focus on instantaneous traffic fl ow optimization on a roundabout using a macroscopic approach. The roundabout is modeled as a concatenation of 2x2 junctions with one main lane and secondary incoming and outgoing roads. We consider a cost functional that measures the total travel time spent by drivers on the roundabout and compute its gradient with respect to the priority parameters at junctions. Then, through numerical simulations, the traffic behavior is studied on the whole roundabout. The numerical approximations compare the performance of a roundabout for instantaneous optimization of the priority parameters and fixed constant parameters
Gradient-based Instantaneous Traffic Flow Optimization on a Roundabout
Full text linkIn this article we focus on instantaneous traffic fl ow optimization on a roundabout using a macroscopic approach. The roundabout is modeled as a concatenation of 2x2 junctions with one main lane and secondary incoming and outgoing roads. We consider a cost functional that measures the total travel time spent by drivers on the roundabout and compute its gradient with respect to the priority parameters at junctions. Then, through numerical simulations, the traffic behavior is studied on the whole roundabout. The numerical approximations compare the performance of a roundabout for instantaneous optimization of the priority parameters and fixed constant parameters
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Controlling crop pest with a farming awareness based integrated approach and optimal control
No full textWe investigate a mathematical model in crop pest controlling, considering
plant biomass, pest, and the effect of farming awareness. The pest population
is divided into two compartments: susceptible pests and infected pests. We
assume that the growth rate of self-aware people is proportional to the density
of susceptible pests existing in the crop arena. Impacts of awareness are
modeled through the usual mass action term and a saturated term. It is further
assumed that self-aware people will adopt chemical and biological control
methods, namely integrated pest management. Bio-pesticides are costly and
require a long-term process, expensive to impose. However, if chemical
pesticides are introduced in the farming system along with bio-pesticides, the
process will be faster as well as cost-effective. Also, farming knowledge is
equally important. In this article, a mathematical model is derived for
controlling crop pests through an awareness-based integrated approach. In order
to reduce the negative effects of pesticides, we apply optimal control theory.Adama Science and Technology University (ASTU), ASTU/SP-R/027/19; Fundação para a Ciência e a Tecnologia, UIDB/04106/2020 (CIDMA).publishe
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Macroscopic traffic flow optimization on roundabouts
Full text linkThe aim of this paper is to propose an optimization strategy for traffic flow on roundabouts using a macroscopic approach. The roundabout is modeled as a sequence of 2 × 2 with one mainline and secondary incoming and outgoing roads. We consider two cost the total travel time and the total waiting time, which give an estimate of the time by drivers on the network section. These cost functionals are minimized with respect to the of way parameter of the incoming roads. For each cost functional, the analytical expression given for each junction
Macroscopic traffic flow optimization on roundabouts
No full textThe aim of this paper is to propose an optimization strategy for traffic flow on roundabouts using a macroscopic approach. The roundabout is modeled as a sequence of 2 × 2 with one mainline and secondary incoming and outgoing roads. We consider two cost the total travel time and the total waiting time, which give an estimate of the time by drivers on the network section. These cost functionals are minimized with respect to the of way parameter of the incoming roads. For each cost functional, the analytical expression given for each junction
Farming awareness based optimum interventions for crop pest control
Full text linkWe develop a mathematical model, based on a system of ordinary differential equations, to the upshot of farming alertness in crop pest administration, bearing in mind plant biomass, pest, and level of control. Main qualitative analysis of the proposed mathematical model, akin to both pest-free and coexistence equilibrium points and stability analysis, is investigated. We show that all solutions of the model are positive and bounded with initial conditions in a certain significant set. The local stability of pest-free and coexistence equilibria is shown using the Routh–Hurwitz criterion. Moreover, we prove that when a threshold value is less than one, then the pest-free equilibrium is locally asymptotically stable. To get optimum interventions for crop pests, that is, to decrease the number of pests in the crop field, we apply optimal control theory and find the corresponding optimal controls. We establish existence of optimal controls and characterize them using Pontryagin's minimum principle. Finally, we make use of numerical simulations to illustrate the theoretical analysis of the proposed model, with and without control measures.publishe
Macroscopic traffic flow optimization on roundabouts
No full textThe aim of this paper is to propose an optimization strategy for traffic flow on roundabouts using a macroscopic approach. The roundabout is modeled as a sequence of 2 × 2 with one mainline and secondary incoming and outgoing roads. We consider two cost the total travel time and the total waiting time, which give an estimate of the time by drivers on the network section. These cost functionals are minimized with respect to the of way parameter of the incoming roads. For each cost functional, the analytical expression given for each junction
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