The MAC performance of IEEE 802.11 DCF and the IEEE 802.11e EDCA is analyzed in nonsaturated condition which means sometimes the device does not have a packet for transmission. In this paper we assume that there is no generation of flow while the previous flow is in service and the number of packets in flow is geometrically distributed. In the non-saturated condition, the first packet arriving ...

INTRODUCTION As further restrictions have been placed on tobacco advertising and promotions, point-of-sale (PoS) displays of cigarettes in shops have become an increasingly important source of young people's exposure to tobacco products. This study explored the relationship between PoS displays of cigarettes and brand awareness among secondary school students in Scotland. METHODS Cross-sectio...

This paper presents a new mathematical model for a hybrid flow shop scheduling problem with multiprocessor tasks in which sequence dependent set up times and preemption are considered. The objective is to minimize the weighted sum of makespan and maximum tardiness. Three meta-heuristic methods based on genetic algorithm (GA), imperialist competitive algorithm (ICA) and a hybrid approach of GA a...

the hybrid molten/solid in2o3 - 30-48 wt.% bi2o3 oxide materials were studied with respect to their transport properties. the conductivities, oxygen ion transport numbers and oxygen permeation fluxes have been measured by using the four-probe dc, volumetric measurements of the faradaic efficiency and gas flow techniques, respectively. we show that the oxygen permeability of the hybrid molten/so...

WuXianGouXiang is an O2O(offline to online and vice versa)-based mobile application that recommends the nearby coupons and deals for users, by which users can also follow the shops they are interested in. If the potential followers of a shop can be discovered, the merchant’s targeted advertising can be more effective and the recommendations for users will also be improved. In this paper, we pro...

This paper develops an evaluation and enhancement approach of the carbon footprints (CFs) based environmentally sustainable service competitiveness for coffees shops. Firstly, the proposed approach uses the service blueprint to analyse the service process of coffee shops and the working times of the required direct facilities and the supporting facilities to estimate the amounts of greenhouse g...

In this short paper, we would like to call professional community’s attention to a daring idea that is surely unhelpful, but is exciting for programmers and anyway conflicts with the trend of energy consumption in computer systems.