The effect of impurities on quantum chemical parameters of single-walled nanotubes (SWNTs) was studied using density functional theory (DFT). The density of states (DOS), Fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. It was found that this nanotube remains metallic after being doped with one nitrogen atom. The partial den...

Users and providers increasingly disagree on what Denial of Service (DoS) is. For example, an ISP might consider large multimedia downloads an attack to overload its infrastructure or have it pay high interconnection fees. On the other hand, a user will certainly consider selective bandwidth reduction that is used by ISPs as a countermeasure, as a DoS measure. Given the nature of their business...

One mechanism used by receptor tyrosine kinases to relay a signal to different downstream effector molecules is to use adaptor proteins that provide docking sites for a variety of proteins. The daughter of sevenless (dos) gene was isolated in a genetic screen for components acting downstream of the Sevenless (Sev) receptor tyrosine kinase. Dos contains a N-terminally located PH domain and sever...

1Research Fellow, Department of Dental Materials and Prosthodontics, São José dos Campos Dental School, São Paulo State University, São José dos Campos, SP, Brazil. 2DDS, PhD student, Department of Dental Materials and Prosthodontics, São José dos Campos Dental School, São Paulo State University, São José dos Campos, SP, Brazil. 3DDS, DMD, PhD student, Dental Materials and Prosthodontics, Arara...

Di ver sos ti pos de po li es ti re no mo di fi ca dos fo ram ob ti dos atra vés da po li me ri za ção por en xer tia (graft poly me ri za ti on) de es ti re no na pre sen ça dos se guin tes mo di fi ca do res: co po lí me ro de eti le no-acetato de vi ni la (EVA); po li e ti le no de ba i xa den si da de (PE) e po li bu ta di e no (PB). Os mo di fi ca do res fo ram uti li za dos em se pa ra do...

The Denial of service (DoS) and Distributed Denial of Service (DDoS) attacks are aimed at maliciously consuming the available resources in computing systems to prevent genuine users from legitimately accessing them. These attacks can easily interrupt or disable targeted systems, so it is important for the system to detect and filter bogus connection requests as early as possible. Many common pr...

VANET (Vehicular Ad-hoc Network) which is a hy- brid network (combination of infrastructure and infra- structure-less networks) is an emergent technology with promising future as well as great challenges especially in security. By the other hand this type of network is very sensible to safety problem. This paper focuses on a new mechanism for DoS (denial of service) attacks on the physical and ...

the density of state and the natural bond orbital calculations were carried out to study theoxidation of co on au14 nano cluster through two different mechanisms and determining the bestmechanism for the reaction. chemisorption of o2 and co on the nano cluster led to change in energy,density of state and its thermodynamic properties. we calculated the energy band gap between thehighest occupied...

DoS attack tools have become increasingly sophisticated challenging the existing detection systems to continually improve their performances. In this paper we present a victimend DoS detection method based on Artificial Neural Networks (ANN). In the proposed method a Feed-forward Neural Network (FNN) is optimized to accurately detect DoS attack with minimum resources usage. The proposed method ...

Received: 06/25/2007 Approved: 12/18/2007 Portugu se / English: www.scielo.br/reeusp RESUMO Este é um estudo exploratório de natureza quantitativa e qualitativa, que avalia o desempenho dos serviços de saúde na execução do DOT no domicílio em um município de grande porte. Para a análise quantitativa foram construídos indicadores que avaliaram a otimização dos recursos materiais/ humanos e a efe...