50 research outputs found
Wi-Fi Access point system manager
[ESP]Los estándares de comunicaciones inalámbricas especifican protocolos para asegurar las comunicaciones en el interfaz aéreo pero no indican ningún método para gestionar un sistema de AAT (autenticación,autorización y tarifación) que garantice que los protocolos especificados se activan y funcionancorrectamente. Los fabricantes de equipos de comunicaciones inalámbricos forman consorcios para desarrollar equipos con una serie de funcionalidades, que en muchos casos deriva en un estándar internacional, lo que facilita la interconexión de equipos entre diferentes fabricantes. El principal problema técnico radica en que el cliente final que adquiere esos equipos no puede activar la mayoría decapacidades del equipo a no ser que disponga de un dispositivo externo que lo haga. El dispositivo externo debe ser lo suficientemente flexible para facilitar cualquier tipo de configuración, de forma local o remota. El sistema desarrollado consiste en la implementación de 4 elementos: 1.a) Un sistema de autenticación compatible con el estandard inalámbrico. 1.b) Un sistema de presentación de páginas web dinámicas.1.c) Un sistema de gestión de datos. 1.d) Un sistema de cifrado de la información.[ENG] The standards of wireless communications specify protocols to provide secure communications in the aerial interface but they do not indicate any method to manage a AAA system (authentication, authorization and accounting) that guarantees that the specified protocols are activated and work correctly. The manufacturers of wireless communications equipment form partnerships to develop equipment with a series of functionalities, that in many cases derives in an international standard, which facilitates the interconnection of equipment between different manufacturers. The main technical problem is that the final client acquiring those equipment cannot activate most of capacities of the equipment unless an external device does it. The external device must be flexible enough to facilitate any type of configuration on local or remote. The developed system consists of the implementation of 4 elements: 1.a) An authentication method compatible with the wi-fi standard. 1.b) A system of presentation based on dynamic pages Web. 1.c) A system of data management.1.d) A system of information coding.[ESP]Una universidad española ha desarrollado un sistema que permite la gestión y configuración remota de múltiples Puntos de Acceso de una red wi-fi. Incorpora control de acceso y seguridad basadas en IEEE
802.11i. El sistema está desarrollado sobre Linux y es válido para cualquier tipo de cliente (PDA, PC, etc. Windows o Linux). La universidad está buscando socios para adaptar y comercializar la tecnología en el mercado.[ENG]UPCT, Spain. The system allows remote management and configuration of several wi-fi APs in a wireless network. It incorporates access control a security issues based on IEEE 802.11i. Developed under Linux. Valid for any kind of client. We need help for merchandising.[ESP] Reducción de costes en la ampliación de la red de datos. Aumento de la productividad de la empresa derivado del uso de redes wi-fi.Facilidad para innovar. Servicios de voz y valor añadido sobre wi-fi. [ENG] Cost reductions when deployment the data network. Gain in company productivity thanks to wi-fi networks. Innovation facility. Voice services and other added value services over wi-fi.Arquitecturas de conmutación electrónica y fotónica. Redes Overlay (desarrollo de protocolos multicast y P2P, distribución de contenidos multimedia). Calidad de servicio en redes heterogéneas.Redes inalámbicas.Redes de sensores y actuadores inalámbricos.Integración de sistemas a través de middleware.Desarrollo de aplicaciones y servicios telemáticos avanzados
Proportional bandwidth distribution in IP networks implementing the assured forwarding PHB
Recent demands for new applications are giving rise
to an increasing need of Quality of Service (QoS).
Nowadays, most IP-based networks tend to use the
DiffServ architecture to provide end-to-end QoS.
Traffic conditioners are a key element in the
deployment of DiffServ. In this paper, we introduce a
new approach for traffic conditioning based on feedback
signaling among boundary nodes and traffic
conditioners. This new approach is intended to provide
a poportional distribution of excess bandwidth to endusers.
We evaluate through extensive simulations the
performance of our proposal in terms of final
throughput, considering contracted target rates and
distribution of spare bandwidth. Results show a high
level of fairness in the excess bandwidth allocation
among TCP sources under different network
conditions
End-to-end TCP performance of the couple CBM traffic conditioner and RIO buffer management in a three node topology
Despite the abundant literature written about the AF PHB,
no solution has been found to efficiently face up its two
goals, assuring a minimum rate to the users and offering a
fair distribution of the excess bandwidth if available. The
Counters Based Modified (CBM) traffic conditioner,
presented in a previous work, is able to achieve these
objectives in single-node topologies. This paper raises
issues with providing bandwidth assurance and spare
bandwidth distribution for TCP flows in more complex
topologies than usual. Simulation results explore the
effect of target rates, round trip times, and efficiency of
CBM when up to three network nodes implement service
differentiation, including in some cases the coexistence of
assured service and best-effort traffics.This work was supported by the Spanish Research
Council under projects TEC2004-05622-C04-02/TCM
and TIC2001-3339-C02-02
Application of artificial intelligence to refrigeration systems
Refrigeration systems currently use 20% of the total electrical energy, and this consumption
is expected to increase by more than 30% between now and 2050. The optimization
of these systems makes it possible to minimize CO2 emissions, increase energy efficiency
and reduce costs. However, refrigeration system optimization problems are complex and time
consuming. This is where sensorization and artificial intelligence come into play. Not many
years ago, refrigeration systems were controlled with analog thermostats, and centralized
supervision by SCADA systems using the data from sensors. Currently, we are in a completely
digitized world thanks to massive sensorization, which is possible due to the development
of the IoT (Internet of Things). The fundamental premise of the IoT is to connect the unconnectable
by enabling new services and experiences. Complex machines and systems such as
refrigeration systems can be measured comprehensively, down to the component level, and
their data streams studied in real-time analysis systems. In this case, artificial intelligence
can take the data to drive decision-making
Tecnologías avanzadas para afrontar el reto de la innovación educativa
Since the arrival of the Internet in Spain in the 1990s, digital technologies have demonstrated their multitude and diversity of applications in various fields, including education. We use the concept of advanced technologies to refer to the latest technological developments within the field of digital technologies, including both software and hardware developments. In this paper, we review some relevant and interesting works related to this topic of advanced technologies. We have utilized an analytical review method and have carried out the selection of didactic experiences around four categories which we have considered of relevance: computation (robotics, computational thinking and artificial intelligence), extended reality (augmented reality and virtual reality), games (video games, serious games) and educational tools (LMS, apps). With these descriptors, we have searched educational experiences that can serve as examples of good educational practices with advanced technologies. The references, which we collect, may be of interest and use to researchers or to educational professionals who are searching specific information on these topics. The main conclusion we reach is that the bibliography is extensive, and this shows the interest that these themes generate within the scientific field. Furthermore, it shows the wide range of possibilities of application of these technologies, both in formal and non-formal contexts, as well as informal experiences.Desde la llegada de internet a España en los años 90, las tecnologías digitales han demostrado su multitud y diversidad de aplicaciones en diversos campos, entre ellos en educación. Utilizamos el concepto de tecnologías avanzadas para denominar los últimos desarrollos tecnológicos dentro del ámbito de las tecnologías digitales, incluyendo tanto desarrollos de software, como hardware. En este artículo hacemos una revisión de algunos trabajos de relevancia e interés en relación con este tema de las tecnologías avanzadas. Hemos utilizado un método de revisión analítica y hemos llevado a cabo la selección de experiencias didácticas en torno a cuatro categorías que hemos considerado de especial relevancia: computación (robótica, pensamiento computacional e inteligencia artificial), realidad extendida (realidad aumentada y realidad virtual), juegos (videojuegos, juegos serios) y herramientas para educación (EVEA, apps). Con estos descriptores, hemos buscado experiencias educativas que puedan servir como ejemplos de buenas prácticas educativas con tecnologías avanzadas. Las referencias que recogemos pueden ser de interés y utilidad a los investigadores o a profesionales de la educación que busquen información específica sobre estos temas. La principal conclusión a la que llegamos es que la bibliografía es amplia y eso pone de manifiesto el interés que estos tópicos generan en el ámbito científico. Además, se demuestra el amplio abanico de posibilidades de aplicación de estas tecnologías, tanto en contextos formales, como no formales o experiencias informales
A certification authority for elliptic curve X.509v3. Certificates
Wireless networks are more and more common in current communications networks. Nevertheless, wireless communications entail a big concern: security. The use of X.509v3 certificates to carry out authentication tasks is an approach to improve security. These certificates are usually employed with the RSA algorithm. Elliptic Curve Cryptography (ECC) is a cryptographic technique eminently suited for small devices, like those used in wireless communications, and is gaining momentum. The main advantage of ECC versus RSA is that for the same level of security it requires a much sorter key length. The purpose of this work is to design and implement a free open-source Certification Authority able to issue X.509v3 certificates using ECC. This research is an implementation study on free open-source tools to issue digital certificates using ECC. Moreover, it contributes to the development of free open-source tools for network security based on ECC. The result of this research may assist organizations to increase their security level in wireless devices and networks, in a costless way, by including authentication techniques based on ECC digital certificates
Experimental Tests on SCTP over IPSec
As telecommunication technologies evolve, security in communications becomes a more and more relevant issue. IPSec is a set of protocols aiming to enhance security at the IP layer. Specifically, IPSec and IKE are important security mechanism that provide cryptographic-based protection for IP packets, and consequently for IP services. SCTP is a standardized transport protocol whose main features include multihoming and multistreaming, and is gaining momentum as a general-purpose transport protocol. While the simultaneous use of these two protocols is feasible, it is under study how to make them work efficiently. In this paper, we present a simple method to improve SCTP-IPSec-IKE compatibility by modifying the structure of the Security Associations. Despite the conceptual simplicity of our proposal, it has not been proposed before in related literature.This research has been supported by project grant TEC2007-67966-01/TCM (CON-PARTE-1) and it is also developed in the framework of "Programa de Ayudas a Grupos de Excelencia de la Región de Murcia, de la Fundación Séneca, Agencia de Ciencia y Tecnología de la RM (Plan Regional de Ciencia y Tecnología 2007/2010)
Spectroscopy transmittance by LED calibration
Local administrations demand real-time and continuous pollution monitoring in sewer networks. Spectroscopy is a non-destructive technique that can be used to continuously monitor quality in sewers. Covering a wide range of wavelengths can be useful for improving pollution characterization in wastewater. Cost-effective and in-sewer spectrophotometers would contribute to accomplishing discharge requirements. Nevertheless, most available spectrometers are based on incandescent lamps, which makes it unfeasible to place them in a sewerage network for real-time monitoring. This research work shows an innovative calibration procedure that allows (Light-Emitting Diode) LED technology to be used as a replacement for traditional incandescent lamps in the development of spectrophotometry equipment. This involves firstly obtaining transmittance values similar to those provided by incandescent lamps, without using any optical components. Secondly, this calibration process enables an increase in the range of wavelengths available (working range) through a better use of the LED's spectral width, resulting in a significant reduction in the number of LEDs required. Thirdly, this method allows important reductions in costs, dimensions and consumptions to be achieved, making its implementation in a wide variety of environments possible.This research was funded by Seneca Foundation of the Región de Murcia (Spain) and “Hidrogea, Gestión Integral de Aguas de Murcia S.A”. Authors wish to thank the financial support received from the Seneca Foundation of the Región de Murcia (Spain) through the program devoted for training of novel researchers in areas of specific interest for the industry and with a high capacity to transfer the results of the research generate entitled: “Subprograma Regional de Contratos de Formación de Personal Investigador en Universidades y OPIs” (Mod. B, Ref. 20320/FPI/17).Authors wish to thank the financial support received from the Seneca Foundation of the Región de Murcia (Spain) through the program devoted for training of novel researchers in areas of specific interest for the industry and with a high capacity to transfer the results of the research generate entitled:
“Subprograma Regional de Contratos de Formación de Personal Investigador en Universidades y OPIs” (Mod. B, Ref. 20320/FPI/17)
Wastewater quality estimation through spectrophotometry-based statistical models
Local administrations are increasingly demanding real-time continuous monitoring of pollution in the sanitation system to improve and optimize its operation, to comply with EU environmental policies and to reach European Green Deal targets. The present work shows a full-scale Wastewater Treatment Plant field-sampling campaign to estimate COD, BOD5, TSS, P, TN and NO3-N in both influent and effluent, in the absence of pre-treatment or chemicals addition to the samples, resulting in a reduction of the duration and cost of analysis. Different regression models were developed to estimate the pollution load of sewage systems from the spectral response of wastewater samples measured at 380-700 nm through multivariate linear regressions and machine learning genetic algorithms. The tests carried out concluded that the models calculated by means of genetic algorithms can estimate the levels of five of the pollutants under study (COD, BOD5, TSS, TN and NO3-N), including both raw and treated wastewater, with an error rate below 4%. In the case of the multilinear regression models, these are limited to raw water and the estimate is limited to COD and TSS, with less than a 0.5% error rateThe authors wish to thank the financial support received from the Seneca Foundation of the Región de Murcia (Spain) through the program devoted to training novel researchers in areas of specific interest for the industry and with a high capacity to transfer the results of the research generated, entitled: “Subprograma Regional de Contratos de Formación de Personal Investigador en Universidades y OPIs” (Mod. B, Ref. 20320/FPI/17)
Performing calibration of transmittance by single rgb-led within the visible spectrum
Spectrophotometry has proven to be an effective non-invasive technique for the characterization of the pollution load of sewer systems, enabling compliance with new environmental protection regulations. This type of equipment has costs and an energy consumption which make it difficult to place it inside a sewer network for real-time and massive monitoring. These shortcomings are mainly due to the use of incandescent lamps to generate the working spectrum as they often require the use of optical elements, such as diffraction gratings, to work. The search for viable alternatives to incandescent lamps is key to the development of portable equipment that is cheaper and with a lower consumption that can be used in different points of the sewer network. This research work achieved the following results in terms of the measured samples: First, the development a calibration procedure that enables the use of RGB-LED technology as a viable alternative to incandescent lamps, within the range of 510 to 645 nm, with high accuracy. Secondly, demonstration of a simple method to model the transmittance value of a specific wavelength without the need for optical elements, achieving a cost-effective equipment. Thirdly, it provides a simple method to obtain the transmittance based on the combination of RGB colors. Finally its viability is demonstrated for the spectral analysis of wastewater.The authors are grateful for the financial support received from the Seneca Foundation of the Región de Murcia (Spain) through the program devoted to training novel researchers in areas of specific interest for the industry and with a high capacity to transfer the results of the research generated, entitled: “Subprograma Regional de Contratos de Formación de Personal Investigador en Universidades y OPIs” (Mod. B, Ref. 20320/FPI/17)