Many membrane-bound molecules in cells form small clusters. It has been hypothesized that these clusters convert an analog extracellular signal into a digital intracellular signal and that this conversion increases signaling fidelity. However, the mechanism by which clusters digitize a signal and the subsequent effects on fidelity remain poorly understood. Here we demonstrate using a stochastic...

The evolution of altruistic behavior through group selection is generally viewed as possible in theory but unlikely in reality, because individual selection favoring selfish strategies should act more rapidly than group selection favoring cooperation. Here we demonstrate the evolution of altruism, in the form of conditional reproductive restraint based on an explicitly social mechanism, modulat...

With the development of wireless communication, signal processing and Micro Electro Mechanical System(MEMS), a new wireless network named wireless sensor network(WSN) came into being. However, due to the limitations of sensor node, e.g., limited energy, wireless wideband and computation capability, there are many novel challenges in the area of wireless sensor network. It is unpractical to depe...

In future wireless networks, cooperation between the base stations may reduce the effects of intercell interference and enhance the capacity per cell. In this paper, the potential of such cooperation is evaluated using measurements of the informationtheoretic channel capacity at 5.2 GHz in 4 overlapping urban microcells with 5 users. In each link, a 10-transmit 16-receive antenna configuration ...

Abstract In this paper, symbol-error-rate (SER) performance analysis and optimum power 1 allocation are provided for uncoded cooperative communications in wireless networks with 2 either decode-and-forward (DF) or amplify-and-forward (AF) cooperation protocol, in which 3 source and relay send information to destination through orthogonal channels. In case of the 4 DF cooperation systems, closed...

Reticulate evolution is a fundamental process in the evolution of certain groups of taxa. Consequently, conflicting signals in a data set may not be the result of sampling or modelling errors, but due to the fact that reticulation has played a role in the evolutionary history of the species under consideration. However, despite its occurrence, such processes are still relatively rare, and so, a...

In this paper, we derive a new achievable rate region for the user cooperation channel, which exceeds the best known result for this channel [Wil83]. Since the user cooperation channel includes many other known channels as a special case, the new rate region provides an improved achievable rates for many of the special cases (discussed later). The most notable example is that of the Gaussian re...

Model predictive control (MPC) is one of the few techniques which is able to handle with constraints on both state and input of the plant. The admissible evolution and asymptotically convergence of the closed loop system is ensured by means of a suitable choice of the terminal cost and terminal contraint. However, most of the existing results on MPC are designed for a regulation problem. If the...

We show that the available constraints relating to LiBeB Galactic evolution can be accounted for by the so-called superbubble model, according to which particles are efficiently accelerated inside superbubbles out of a mixture of supernova ejecta and ambient interstellar medium. The corresponding energy spectrum is required to be flat at low energy (in E below 500 MeV/n, say), as expected from ...

Density waves in the central kpc of galaxies, taking the form of spirals, bars and/or lopsided density distributions, are potential actors of the redistribution of angular momentum. They may thus play an important role in the overall evolution of the central structures, not mentioning the possible link with the active/non-active central mass concentration. I present here some evidence for the p...