An Incremental Algorithm for Computing Cylindrical Algebraic Decompositions

In this paper, we propose an incremental algorithm for computing cylindrical algebraic decompositions. The algorithm consists of two parts: computing a complex cylindrical tree and refining this complex tree into a cylindrical tree in real space. The incrementality comes from the first part of the algorithm, where a complex cylindrical tree is constructed by refining a previous complex cylindrical tree with a polynomial constraint. We have implemented our algorithm in Maple. The experimentation shows that the proposed algorithm outperforms existing ones for many examples taken from the literature

An anonymity layer for JXTA service

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An Algorithm for Computing the Limit Points of the Quasi-component of a Regular Chain

For a regular chain $R$, we propose an algorithm which computes the (non-trivial) limit points of the quasi-component of $R$, that is, the set $\bar{W(R)} \setminus W(R)$. Our procedure relies on Puiseux series expansions and does not require to compute a system of generators of the saturated ideal of $R$. We focus on the case where this saturated ideal has dimension one and we discuss extensions of this work in higher dimensions. We provide experimental results illustrating the benefits of our algorithms

Security analysis of JXME-Proxyless version

JXME es la especificación de JXTA para dispositivos móviles con J2ME. Hay dos versiones diferentes de la aplicación JXME disponibles, cada una específica para un determinado conjunto de dispositivos, de acuerdo con sus capacidades. El principal valor de JXME es su simplicidad para crear peer-to-peer (P2P) en dispositivos limitados. Además de evaluar las funciones JXME, también es importante tener en cuenta el nivel de seguridad por defecto que se proporciona. Este artículo presenta un breve análisis de la situación actual de la seguridad en JXME, centrándose en la versión JXME-Proxyless, identifica las vulnerabilidades existentes y propone mejoras en este campo.JXME és l'especificació de JXTA per a dispositius mòbils amb J2ME. Hi ha dues versions diferents de l'aplicació JXME disponibles, cada una d'específica per a un determinat conjunt de dispositius, d'acord amb les seves capacitats. El principal valor de JXME és la seva simplicitat per crear peer-to-peer (P2P) en dispositius limitats. A més d'avaluar les funcions JXME, també és important tenir en compte el nivell de seguretat per defecte que es proporciona. Aquest article presenta un breu anàlisis de la situació actual de la seguretat en JXME, centrant-se en la versió JXME-Proxyless, identifica les vulnerabilitats existents i proposa millores en aquest camp.JXME is the JXTA specification for mobile devices using J2ME. Two different flavors of JXME implementation are available, each one specific for a particular set of devices, according to their capabilities. The main value of JXME is its simplicity to create peer-to-peer (P2P) applications in limited devices. In addition to assessing JXME functionalities, it is also important to realize the default security level provided. This paper presents a brief analysis of the current state of security in JXME, focusing on the JXME-Proxyless version, identifies existing vulnerabilities and proposes further improvements in this field

Overcoming organic and nitrogen overload in thermophilic anaerobic digestion of pig slurry by coupling a microbial electrolysis cell

The combination of the anaerobic digestion (AD) process with a microbial electrolysis cell (MEC) coupled to an ammonia stripping unit as a post-treatment was assessed both in series operation, to improve the quality of the effluent, and in loop configuration recirculating the effluent, to increase the AD robustness. The MEC allowed maintaining the chemical oxygen demand removal of the whole system of 46 ± 5% despite the AD destabilization after doubling the organic and nitrogen loads, while recovering 40 ± 3% of ammonia. The AD-MEC system, in loop configuration, helped to recover the AD (55% increase in methane productivity) and attained a more stable and robust operation. The microbial population assessment revealed an enhancement of AD methanogenic archaea numbers and a shift in eubacterial population. The AD-MEC combined system is a promising strategy for stabilizing AD against organic and nitrogen overloads, while improving the quality of the effluent and recovering nutrients for their reutilization.Postprint (author's final draft