103 research outputs found
Global attractivity of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion
AbstractBy employing the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion is established. Further, by constructing a Lyapunov functional and using the result of the existence of positive periodic solution, the attractivity of a positive periodic solution for above system is obtained
Improving Neural Relation Extraction with Positive and Unlabeled Learning
We present a novel approach to improve the performance of distant supervision
relation extraction with Positive and Unlabeled (PU) Learning. This approach
first applies reinforcement learning to decide whether a sentence is positive
to a given relation, and then positive and unlabeled bags are constructed. In
contrast to most previous studies, which mainly use selected positive instances
only, we make full use of unlabeled instances and propose two new
representations for positive and unlabeled bags. These two representations are
then combined in an appropriate way to make bag-level prediction. Experimental
results on a widely used real-world dataset demonstrate that this new approach
indeed achieves significant and consistent improvements as compared to several
competitive baselines.Comment: 8 pages, AAAI-202
Two Periodic Solutions of Nonlinear Systems with Feedback Control
Abstract In this paper, by the well-known Deimling fixed point theorem in a cone, we consider the following nonlinear functional differential system with feedback control where λ is a positive parameter. We obtain the results on the existence and multiplicity of positive periodic solutions
Existence and Global Exponential Stability of Periodic Solution to Cohen-Grossberg BAM Neural Networks with Time-Varying Delays
We investigate first the existence of periodic solution in general Cohen-Grossberg BAM neural networks with multiple time-varying delays by means of using degree theory. Then using the existence result of periodic solution and constructing a Lyapunov functional, we discuss global exponential stability of periodic solution for the above neural networks. Our result on global exponential stability of periodic solution is different from the existing results. In our result, the hypothesis for monotonicity ineqiality conditions in the works of Xia (2010) Chen and Cao (2007) on the behaved functions is removed and the assumption for boundedness in the works of Zhang et al. (2011) and Li et al. (2009) is also removed. We just require that the behaved functions satisfy sign conditions and activation functions are globally Lipschitz continuous
Autonomous Crowdsensing: Operating and Organizing Crowdsensing for Sensing Automation
The precise characterization and modeling of Cyber-Physical-Social Systems
(CPSS) requires more comprehensive and accurate data, which imposes heightened
demands on intelligent sensing capabilities. To address this issue,
Crowdsensing Intelligence (CSI) has been proposed to collect data from CPSS by
harnessing the collective intelligence of a diverse workforce. Our first and
second Distributed/Decentralized Hybrid Workshop on Crowdsensing Intelligence
(DHW-CSI) have focused on principles and high-level processes of organizing and
operating CSI, as well as the participants, methods, and stages involved in
CSI. This letter reports the outcomes of the latest DHW-CSI, focusing on
Autonomous Crowdsensing (ACS) enabled by a range of technologies such as
decentralized autonomous organizations and operations, large language models,
and human-oriented operating systems. Specifically, we explain what ACS is and
explore its distinctive features in comparison to traditional crowdsensing.
Moreover, we present the ``6A-goal" of ACS and propose potential avenues for
future research
Fibrillation of chain branched poly (lactic acid) with improved blood compatibility and bionic structure
YesHighly-oriented poly (lactic acid) (PLA) with bionic fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLA was first chain branched with pentaerythritol polyglycidyl ether (PGE). The branching degree as high as 12.69 mol% can be obtained at 0.5 wt% PGE content. The complex viscosity, elastic and viscous modulus for chain branched PLA were improved resulting from the enhancement of molecular entanglement, and consequently higher draw ratio can be achieved during the subsequent hot stretching. The stress-induced crystallization of PLA occurred during stretching, and the crystal structure of the oriented PLA can be attributed to the α′ crystalline form. The tensile strength and modulus of PLA were improved dramatically by drawing. Chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing hemolysis ratio, protein adsorption and platelet activation. Fibrous structure as well as micro-grooves can be observed for the oriented PLA which were similar to intimal layer of blood vessel, and this bionic structure was considered to be beneficial to decrease the activation and/or adhesion of platelets
Blow-Up and Global Existence for a Degenerate Parabolic System with Nonlocal Sources
This paper investigates the blow-up and global existence of nonnegative solutions for a class of nonlocal degenerate parabolic system. By using the super- and subsolution techniques, the critical exponent of the system is determined. That is, if Pc=p1q1−(m−p2)(n−q2)<0, then every nonnegative solution is global, whereas if Pc>0, there are solutions that blowup and others that are global according to the size of initial values u0(x)
and v0(x). When Pc=0, we show that if the domain is sufficiently small, every nonnegative solution is global while if the domain large enough that is, if it contains a sufficiently large ball, there is no global solution
Existence of Positive Periodic Solutions for a Nonautonomous Generalized Predator-Prey System with Time Delay in Two-Patch Environment
By using continuation theorem of coincidence degree theory, sufficient conditions of the existence of positive periodic solutions are obtained for a generalized predator-prey system with diffusion and delays. In this paper, we construct a V-function to make the prior estimation for periodic solutions, which makes the discussion more concise. Moreover, to compute the mapping's topological degree, a polynomial function matrix is constructed straightforwardly as a homotopic mapping for the generalized one, which improves the methods of computation on topological degree for a generalized mapping
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