Global attractors for singular perturbations of the Cahn–Hilliard equations

AbstractWe consider the singular perturbations of two boundary value problems, concerning respectively the viscous and the nonviscous Cahn–Hilliard equations in one dimension of space. We show that the dynamical systems generated by these two problems admit global attractors in the phase space H01(0,π)×H-1(0,π), and that these global attractors are at least upper-semicontinuous with respect to the vanishing of the perturbation parameter

A Herding Model with Preferential Attachment and Fragmentation

We introduce and solve a model that mimics the herding effect in financial markets when groups of agents share information. The number of agents in the model is growing and at each time step either (i) with probability p an incoming agent joins an existing group, or (ii) with probability 1-p a group is fragmented into individual agents. The group size distribution is found to be power-law with an exponent that depends continuously on p. A number of variants of our basic model are discussed. Comparisons are made between these models and other models of herding and random growing networks

Constrained Network Slicing Games: Achieving service guarantees and network efficiency

Network slicing is a key capability for next generation mobile networks. It enables one to cost effectively customize logical networks over a shared infrastructure. A critical component of network slicing is resource allocation, which needs to ensure that slices receive the resources needed to support their mobiles/services while optimizing network efficiency. In this paper, we propose a novel approach to slice-based resource allocation named Guaranteed seRvice Efficient nETwork slicing (GREET). The underlying concept is to set up a constrained resource allocation game, where (i) slices unilaterally optimize their allocations to best meet their (dynamic) customer loads, while (ii) constraints are imposed to guarantee that, if they wish so, slices receive a pre-agreed share of the network resources. The resulting game is a variation of the well-known Fisher market, where slices are provided a budget to contend for network resources (as in a traditional Fisher market), but (unlike a Fisher market) prices are constrained for some resources to provide the desired guarantees. In this way, GREET combines the advantages of a share-based approach (high efficiency by flexible sharing) and reservation-based ones (which provide guarantees by assigning a fixed amount of resources). We characterize the Nash equilibrium, best response dynamics, and propose a practical slice strategy with provable convergence properties. Extensive simulations exhibit substantial improvements over network slicing state-of-the-art benchmarks

A comprehensive weighted evolving network model

Many social, technological, biological, and economical systems are best described by weighted networks, whose properties and dynamics depend not only on their structures but also on the connection weights among their nodes. However, most existing research work on complex network models are concentrated on network structures, with connection weights among their nodes being either 1 or 0. In this paper, we propose a new weighted evolving network model. Numerical simulations indicate that this network model yields three power-law distributions of the node degrees, connection weights and node strengths. Particularly, some other properties of the distributions, such as the droop-head and heavy-tail effects, can also be reflected by this model.Comment: 6 pages, 4 figures, accepted by Physica

Forecasting term structure of the Japanese bond yields in the presence of a liquidity trap

The Nelson–Siegel (NS) model is widely used in practice to fit the term structure of interest rates largely due to its high efficacy in the in-sample fit and out-of-sample forecasting of bond yields. In this paper, we compare forecasting performances of estimated yields from the Nelson–Siegel-based models and some simpler time series models, using the daily, weekly, and monthly data during a prolong period of liquidity trap in Japan. We find that the out-of-sample expanding window forecasts by NS-based models in general perform less satisfactory than the competitor models. However, the NS-based models can be useful in forecasting yields over longer horizons and can work well with GARCH-type structures in modeling the conditional volatility

A PERFORMANCE-RELATED FOOT LOADING CHARACTERS WHILE PERFORMING LUNGING STEP AMONG BADMINTON PLAYERS

The purpose of this study was to investigate the foot loading characteristics of badminton athletes and amateurs while performing the right-forward lunging step. Eight badminton male athletes and eight aged-matched college students participated the test in a stimulated badminton court. The Novel pedar insole plantar pressure measuring system was utilized to collect the right feet loading. As the results turn out, the peak pressure and force time integral of amateurs to the lateral reatfoot and lateral forefoot were obviously higher than that of badminton athletes, and athletes showed opposite plantar pressure distribution characteristics. This findings indicated the movement instability thus reducing performance of lunge, even reflect the ankle sprain risks of badminton amateurs