A centralized feedback control model for resource management in wireless networks

In a wireless environment, guaranteeing QoS is challenging because applications at multiple devices share the same limited radio bandwidth. In this paper we introduce and study a resource management model for centralized wireless networks, using feedback control theory. Before applying in practice, the proposed model is evaluated using the well-known 20-sim dynamic system simulator. The experimental results show that flexible and efficient resource allocation can be achieved for a variety of system parameters and WLAN scenarios; however, care should be taken in setting the control parameters and coefficients

This paper exposes an extension of the simplest mathematical model of soil organic matter decomposition. The equation of this model is very common in the literature, for example, Davidescu and Davidescu (1981), or Willigen et al. (2008), considering some

organic matter, time, evolution, mathematical, mode

Bootstrapping Color Constancy

Presented at the Electronic Imaging IV conference, Jan. 1999

Topology Control in Cooperative Ad Hoc Wireless Networks

AbstractCooperative communication (CC) is a technique that exploits spatial diversity allowing multiple nodes to cooperatively relay signals to the receiver so that it can combine the received signals to obtain the original message. CC can be combined with topology control to increase connectivity at the cost of a small increase in energy consumption. This work focuses on exploring CC to improve the connectivity with a sink node in ad hoc wireless networks. More precisely, this work proposes a new technique, named CoopSink, that combines CC and topology control techniques to increase connectivity to a sink node while ensuring energy-efficient routes. Simulation results show that connectivity and routing to the sink cost can be improved up to 6.8 and 2.3 times, respectively, when compared with other similar strategies

Luminance-Based Multi-Scale Retinex

Presented at the AIC Colour 97 8th Congress of the International Colour Association, May 1997

Prognosis on Concentration of Soil Organic Matter Using Maps of Organic Matter Distribution and Progress Mathematical Models

This paper presents a method of prognosis of organic matter content evolution in a plane agricultural surface soil, using the information obtained by initial scanning with spectrophotometrical techniques. The scanning result – map of organic matter content distribution – is used as initial moment distribution for calculating the evolution of soil organic matter content in terms of time. In order to calculate the evolution in time of organic matter quantity, mathematical models described by differential equations known in specialty literature are used: Willigen et al. (2008 are used. .Knowing this evolution, we are able to evaluate the optimum moment applying and the fertilizer quantity necessary for obtaining the appropriate parameters of soil nutrients. Therefore, this method aims at predicting the evolution of organic matter content in an agricultural soil, on a plane surface, for being able to add in due time the chemical fertilizers treatments needed

Vector Representation for the Soil Erosion Model USLE,

This article presents a mathematical viewpoint as vector form on estimating the risk of erosion due to water action, starting from the original USLE. We started with a vector representation of pluviometric regime. Daily amount of rain during a year can be in the form vector graphics. This representation is equivalent to a vector. Starting from this representation is computed the factor of the rain erosivity. We found that other factors in the USLE formula allowed the same type of representation. These representations have been used in the daily calculating for the erosion. This point of view extends the USLE model using to the rainfall event erosivity assessment, similarly with the RUSLE models. This vision permit the comparison between the possible divisions of the annual period: month, weeks, days, hours, minutes or seconds. In this article the solution test are made by comparison of the result with experimental results obtained in the Valea Calugareasca vineyard