Bio-inspired delayed evolutionary game dynamics with?networking applications

We study in this paper some evolutionary games where competition between individuals from a large population occurs through many local interactions between randomly selected individuals. We focus on games that have the property of possessing a single interior evolutionarily stable strategy (ESS). We study in particular the effect of the time delays on the convergence of evolutionary dynamics to the ESS in an evolutionary game in which each pure strategy is associated with its own delay. In particular, we study a multiple access game as well as a Hawk and Dove game. We study the properties of the ESS in these games and also the effect of time delays on the convergence of various bio-inspired evolutionary game dynamics to the ESS.     

Sequential batch sampling

Let {X_i} be i.i.d.{F_θ}.We consider the testing problem H₁θ<θ₀ vs H₂θ≥θ₀, where sampling is done sequentially in batches with variable batch sizes.For some parametric families {F_θ}, and under natural cost struc-ture, we characterize the Bayes procedures. This characterization of Bayes procedures lead to a similar characterization of essentially complete class of procedures.     

Triplet State Interrogation in Supersonic Beams by Surface Electron Ejection

Recently, we have developed an experimental method for the detection of triplet states generated by laser excitation in supersonic beams. It is based on electron ejection from low work-function surfaces by metastable triplet states. We have detected both directly laser-excited triplets and triplets generated via intersystem crossing from laser-excited singlet states. Here, we review the applications of this method and discuss its mechanism. By comparing the laser-induced fluorescence (LIF) spectrum and Surface Electron Ejection by Laser-Excited Metastables (SEELEM), we have measured relative triplet formation quantum yields for several aromatic compounds. By utilizing a detector mounted on a translational stage, we could vary the distance between the pulsed laser excitation and the detector and measure the decay rates of triplets in molecular beams. The major advantage of the method is in extending the measurement of triplet lifetimes to the ∼ 1-ms range. The combination of LIF, SEELEM, and fluorescence quantum yields enabled us to discriminate between intersystem crossing and internal conversion in isoquinoline. SEELEM is now being utilized in studying the spectroscopy and the dynamics of directly laser-excited triplet states. Although the oscillator strength of the lowest triplet state of pyrazine is about 10⁻⁸, we have measured the spectrum and the decay rates of its various vibronic levels. Our results support the notion that surface Penning ionization is the mechanism of SEELEM. The detector is insensitive to vibrational energy (thus enabling the distinction between intersystem crossing and internal conversion). The detection sensitivity of triplets rises with the excess electronic energy and with the lowering of the surface work-function.     

Discriminatory processor sharing queues with stationary ergodic service times and the performance of TCP in overload

In a recent paper, Bonald and Roberts (2001) [6] studied non-persistent TCP connections in transient overload conditions, under the assumption that all connections have the same round-trip times. In this paper our goal is to develop theoretical tools that will enable us to relax this assumption and obtain explicit expressions for the rate of growth of the number of connections at the system, the rate at which TCP connections leave the system, as well as the time needed for the completion of a connection. To that end, we model the system as a discriminatory processor sharing (DPS) system which we analyze under very mild assumptions on the probability distributions related to different classes of arrivals: we only assume that the arrival rates of connections exist, and that the amount of information transmitted during a connection of a given type forms a stationary ergodic sequence. We then proceed to obtain explicit expressions for the growth rate of the number of connections at the DPS system for several specific probability distributions. We check through simulations the applicability of our queueing results for modeling TCP connections sharing a bottleneck.     

Structural and electrochemical studies of PPy/PEG-LiFePO4 cathode material for Li-ion batteries

A simple chemical oxidative polymerization of pyrrole (Py) directly onto the surface of LiFePO₄ particles was applied to the synthesis of polypyrrole-LiFePO₄ (PPy-LiFePO₄) powder. The LiFePO₄ sample without carbon coating was synthesized by a solvothermal method. The polyethylene glycol (PEG) was used as additive during Py polymerization for increasing the PPy-LiFePO₄ conductivity. Properties of resulting LiFePO₄, PPy-LiFePO₄ and PPy/PEG-LiFePO₄ samples were characterized by XRD, SEM, TGA and galvanostatic charge-discharge measurements. These methods confirmed the presence of polypyrrole on LiFePO₄ particles and its homogeneous distribution in the resulting powder material. The PPy/PEG-LiFePO₄ composites show higher discharge capacity than pure LiFePO₄, as PPy/PEG network improves the electron conductivity. It presents specific discharge capacity of 153 mAh/g at C/5 rate.     

NROM: A novel localized trapping, 2-bit nonvolatile memory cell

This paper presents a novel flash memory cell based on localized charge trapping in a dielectric layer and on a new read operation. It is based on the storage of a nominal ~400 electrons above a n⁺/p junction. Programming is performed by channel hot electron injection and erase by tunneling enhanced hot hole injection. The new read methodology is very sensitive to the location of trapped charge above the source. This single device cell has a two physical bit storage capability. The cell shows improved erase performances, no over erase and erratic bit issues, very good retention at 250°C, and endurance up to 1M cycles. Only four masks are added to a standard CMOS process to implement a virtual ground array. In a typical 0.35 μm process, the area of a bit is 0.315 μm² and 0.188 μm² in 0.25 μm technology. All these features and the small cell size compared to any other flash cell make this device a very attractive solution for all NVM applications     

Using “last-minute” sales for vertical differentiation on the Internet

In Internet-based commerce, sellers often use multiple distribution channels for the sale of standard consumer goods. We study a model of second-degree price discrimination in which a monopolist sells to risk-averse buyers. The seller uses two channels that differ in their risk attributes. In one channel prices and qualities are fixed and availability is assured. In the second channel, the seller offers a joint distribution of prices and qualities and may not guarantee availability. We characterize optimal two-channel selling policies. We show that it can be optimal to offer multiple identical items in a random sale event. However, the seller cannot benefit by offering two distinct quality levels in a sale event that is held with probability smaller than one. We use the model to offer explanations for the observed behavior of online sellers and discuss implementation issues in recent e-commerce environments.