We develop a novel theoretical framework for studying ecosystems in which interacting state variables which are affected by management decisions diffuse in space. We identify (i) mechanisms creating spatial patterns when economic agents maximize profit at each site by ignoring the impact of their actions on other sites and (ii) a diffusion induced externality. Pattern formation mechanisms and e...

In this paper we study a version of the Keller–Segel model where the chemotactic cross-diffusion depends on both the external signal and the local population density. A parabolic quasi-linear strongly coupled system follows. By incorporation of a population-sensing (or “quorum-sensing”) mechanism, we assume that the chemotactic response is switched off at high cell densities. The response to hi...

We present a novel method of imaging multiple moving targets using a SAR system transmitting ultra-narrowband continuous waveforms. Our method comprises of a new forward model that relates the velocity as well as re ectivity information at each location to a correlated received signal; and a novel image formation method based on ltered-backprojection and image-contrast optimization. The method ...

Mechanical constraints have strong influence on the dynamics, and structure of granular aggregations. The contact forces within dense suspensions of active particles may give rise to intriguing phenomena including anomalous density fluctuations, long-range orientational ordering, and spontaneous pattern formation. Various authors have proposed that these physical phenomena contribute to the abi...

the sanganeh formation crops out throughout the kopeh-dagh basin and is mainly composed of shale and marl with interbeds of siltstone and limestone. in this study, the sanganeh formation, with 550 meter thickness, has been studied at north of the sanganeh village in eastern parts of the basin. according to distribution of organic matter content, four palynofacies types are identified. the main ...

the kinetics of catalyst deactivation and coke formation during dehydrogenation of propane over supported pt–based catalysts and, in particular, the effect of alkali metal promoters on catalyst activity and stability were studied. the analysis of propane conversion data showed that there is an optimum level of alkali metal promoter loading for both catalyst activity and stability.a model based ...

The systems analysis of thrombosis seeks to quantitatively predict blood function in a given vascular wall and hemodynamic context. Relevant to both venous and arterial thrombosis, a Blood Systems Biology approach should provide metrics for rate and molecular mechanisms of clot growth, thrombotic risk, pharmacological response, and utility of new therapeutic targets. As a rapidly created multic...

There are two methods for identifying formation interface in oil wells: core analysis, which is a precise approach but costly and time consuming, and well logs analysis, which petrophysists perform, which is subjective and not completely reliable. In this paper, a novel coupled method was proposed to detect the formation interfaces using GR logs. Second approximation level (a2) of GR log gained...