La tensión entre las acciones reivindicativas y la proyección política de los sectores populares : Un estudio sobre los límites y las posibilidades de politización de las experiencias recientes de organización popular. El caso del Movimiento de Trabajadores Desocupados de Lanús

El presente plan se propone indagar sobre los procesos de politización de las prácticas y los vínculos sociales de los sectores populares organizados en torno a colectivos de trabajadores desocupados, a partir de las transformaciones políticas y sociales acontecidas en los últimos años. Buena parte de las expectativas y demandas de cambio social suscitadas recientemente se habían depositado en las experiencias de los movimientos piqueteros, en tanto agentes capaces de encarnar prácticas renovadas de organización política y alternativas colectivas de cambio social. Desde su irrupción pública, sin embargo, la literatura académica había advertido sobre las contradicciones que atravesaban a este movimiento social. Una de las dificultades más importantes radicaba en los inconvenientes encontrados por las organizaciones de desocupados para articular políticamente las demandas de subsistencia de sus bases sociales. En el marco de esta propuesta, se interpreta que estas dificultades dan cuenta de una tensión constitutiva que atraviesa al conjunto del movimiento. Esta tensión se expresa en el vínculo problemático entre las dimensiones reivindicativas y las dimensiones políticas de las experiencias piqueteras. En tal sentido, se pretende realizar un balance y una actualización crítica de las alternativas emergentes de construcción política popular, desde la trayectoria de una de las organizaciones de desocupados señaladas como caso ejemplar de renovación política y social. Se tratará, por tanto, de abordar las respuestas articuladas por esta organización a la tensión entre las cuestiones reivindicativas y las cuestiones políticas, en el contexto de las mutaciones producidas recientemente en el escenario político, especialmente a partir de la asunción del gobierno de Néstor Kirchner en el año 2003.

La tensión entre las acciones reivindicativas y la proyección política de los sectores populares : Un estudio sobre los límites y las posibilidades de politización de las experiencias recientes de organización popular. El caso del Movimiento de Trabajadores Desocupados de Lanús

El presente plan se propone indagar sobre los procesos de politización de las prácticas y los vínculos sociales de los sectores populares organizados en torno a colectivos de trabajadores desocupados, a partir de las transformaciones políticas y sociales acontecidas en los últimos años. Buena parte de las expectativas y demandas de cambio social suscitadas recientemente se habían depositado en las experiencias de los movimientos piqueteros, en tanto agentes capaces de encarnar prácticas renovadas de organización política y alternativas colectivas de cambio social. Desde su irrupción pública, sin embargo, la literatura académica había advertido sobre las contradicciones que atravesaban a este movimiento social. Una de las dificultades más importantes radicaba en los inconvenientes encontrados por las organizaciones de desocupados para articular políticamente las demandas de subsistencia de sus bases sociales. En el marco de esta propuesta, se interpreta que estas dificultades dan cuenta de una tensión constitutiva que atraviesa al conjunto del movimiento. Esta tensión se expresa en el vínculo problemático entre las dimensiones reivindicativas y las dimensiones políticas de las experiencias piqueteras. En tal sentido, se pretende realizar un balance y una actualización crítica de las alternativas emergentes de construcción política popular, desde la trayectoria de una de las organizaciones de desocupados señaladas como caso ejemplar de renovación política y social. Se tratará, por tanto, de abordar las respuestas articuladas por esta organización a la tensión entre las cuestiones reivindicativas y las cuestiones políticas, en el contexto de las mutaciones producidas recientemente en el escenario político, especialmente a partir de la asunción del gobierno de Néstor Kirchner en el año 2003.

Distributed routing algorithms for interconnected FDDI LANS

The Fibre Distributed Data Interface (FDDI) represents the new generation of local area networks (LANs). These high speed LANs are capable of supporting up to 500 users over a 100 km distance. User traffic is expected to be as diverse as file transfers, packet voice and video. As the proliferation of FDDI LANs continues, the need to interconnect these LANs arises. FDDI LAN interconnection can be achieved in a variety of different ways. Some of the most commonly used today are public data networks, dial up lines and private circuits. For applications that can potentially generate large quantities of traffic, such as an FDDI LAN, it is cost effective to use a private circuit leased from the public carrier. In order to send traffic from one LAN to another across the leased line, a routing algorithm is required. Much research has been done on the Bellman-Ford algorithm and many implementations of it exist in computer networks. However, due to its instability and problems with routing table loops it is an unsatisfactory algorithm for interconnected FDDI LANs. A new algorithm, termed ISIS which is being standardized by the ISO provides a far better solution. ISIS will be implemented in many manufacturers routing devices. In order to make the work as practical as possible, this algorithm will be used as the basis for all the new algorithms presented. The ISIS algorithm can be improved by exploiting information that is dropped by that algorithm during the calculation process. A new algorithm, called Down Stream Path Splits (DSPS), uses this information and requires only minor modification to some of the ISIS routing procedures. DSPS provides a higher network performance, with very little additional processing and storage requirements. A second algorithm, also based on the ISIS algorithm, generates a massive increase in network performance. This is achieved by selecting alternative paths through the network in times of heavy congestion. This algorithm may select the alternative path at either the originating node, or any node along the path. It requires more processing and memory storage than DSPS, but generates a higher network power. The final algorithm combines the DSPS algorithm with the alternative path algorithm. This is the most flexible and powerful of the algorithms developed. However, it is somewhat complex and requires a fairly large storage area at each node. The performance of the new routing algorithms is tested in a comprehensive model of interconnected LANs. This model incorporates the transport through physical layers and generates random topologies for routing algorithm performance comparisons. Using this model it is possible to determine which algorithm provides the best performance without introducing significant complexity and storage requirements.

Management of services differentiation and guarantee in IEEE 802.11e wireless LANs

In this paper, we study the management and control of service differentiation and guarantee based on enhanced distributed function coordination (EDCF) in IEEE 802.11e wireless LANs. Backoff-based priority schemes are the major mechanism for Quality of Service (QoS) provisioning in EDCF. However, control and management of the backoff-based priority scheme are still challenging problems. We have analysed the impacts of backoff and Inter-frame Space (IFS) parameters of EDCF on saturation throughput and service differentiation. A centralised QoS management and control scheme is proposed. The configuration of backoff parameters and admission control are studied in the management scheme. The special role of access point (AP) and the impact of traffic load are also considered in the scheme. The backoff parameters are adaptively re-configured to increase the levels of bandwidth guarantee and fairness on sharing bandwidth. The proposed management scheme is evaluated by OPNET. Simulation results show the effectiveness of the analytical model based admission control scheme. ©2005 IEEE.

Precise relative clock synchronization for distributed control using TSC registers

Precise clock synchronization is essential in emerging time-critical distributed control systems operating over computer networks where the clock synchronization requirements are mostly focused on relative clock synchronization and high synchronization precision. Existing clock synchronization techniques such as the Network Time Protocol (NTP) and the IEEE 1588 standard can be difficult to apply to such systems because of the highly precise hardware clocks required, due to network congestion caused by a high frequency of synchronization message transmissions, and high overheads. In response, we present a Time Stamp Counter based precise Relative Clock Synchronization Protocol (TSC-RCSP) for distributed control applications operating over local-area networks (LANs). In our protocol a software clock based on the TSC register, counting CPU cycles, is adopted in the time clients and server. TSC-based clocks offer clients a precise, stable and low-cost clock synchronization solution. Experimental results show that clock precision in the order of 10~microseconds can be achieved in small-scale LAN systems. Such clock precision is much higher than that of a processor's Time-Of-Day clock, and is easily sufficient for most distributed real-time control applications over LANs.

A Decentralized Session Management Framework for Heterogeneous Ad-Hoc and Fixed Networks

Wireless technologies are continuously evolving. Second generation cellular networks have gained worldwide acceptance. Wireless LANs are commonly deployed in corporations or university campuses, and their diffusion in public hotspots is growing. Third generation cellular systems are yet to affirm everywhere; still, there is an impressive amount of research ongoing for deploying beyond 3G systems. These new wireless technologies combine the characteristics of WLAN based and cellular networks to provide increased bandwidth. The common direction where all the efforts in wireless technologies are headed is towards an IP-based communication. Telephony services have been the killer application for cellular systems; their evolution to packet-switched networks is a natural path. Effective IP telephony signaling protocols, such as the Session Initiation Protocol (SIP) and the H 323 protocol are needed to establish IP-based telephony sessions. However, IP telephony is just one service example of IP-based communication. IP-based multimedia sessions are expected to become popular and offer a wider range of communication capabilities than pure telephony. In order to conjoin the advances of the future wireless technologies with the potential of IP-based multimedia communication, the next step would be to obtain ubiquitous communication capabilities. According to this vision, people must be able to communicate also when no support from an infrastructured network is available, needed or desired. In order to achieve ubiquitous communication, end devices must integrate all the capabilities necessary for IP-based distributed and decentralized communication. Such capabilities are currently missing. For example, it is not possible to utilize native IP telephony signaling protocols in a totally decentralized way. This dissertation presents a solution for deploying the SIP protocol in a decentralized fashion without support of infrastructure servers. The proposed solution is mainly designed to fit the needs of decentralized mobile environments, and can be applied to small scale ad-hoc networks or also bigger networks with hundreds of nodes. A framework allowing discovery of SIP users in ad-hoc networks and the establishment of SIP sessions among them, in a fully distributed and secure way, is described and evaluated. Security support allows ad-hoc users to authenticate the sender of a message, and to verify the integrity of a received message. The distributed session management framework has been extended in order to achieve interoperability with the Internet, and the native Internet applications. With limited extensions to the SIP protocol, we have designed and experimentally validated a SIP gateway allowing SIP signaling between ad-hoc networks with private addressing space and native SIP applications in the Internet. The design is completed by an application level relay that permits instant messaging sessions to be established in heterogeneous environments. The resulting framework constitutes a flexible and effective approach for the pervasive deployment of real time applications.

Performance analysis of wavelength/time codes with and without hard-limiter

Fiber-optic CDMA technology is well suited for high speed local-area-networks (LANs) as it has good salient features. In this paper, we model the wavelength/time multiple-pulses-per-row (W/T MPR) FO-CDMA network channel, as a Z channel. We compare the performances of W/T MPR code with and without hard-limiter and show that significant performance improvement can be achieved by using hard-limiters in the receivers. In broadcast channels, MAI is the dominant source of noise. Hence the performance analysis is carried out considering only MAI and other receiver noises are neglected.

A emoção em rede: as éticas e estéticas Emo

O presente trabalho consiste em analisar as características mais marcantes da tribo urbana Emo, cuja origem se encontra no estilo musical emocore. Trata-se de um estudo que pontua basicamente a música, sexualidade, moda e sentimentalidades no imaginário emo, apresentadas como elementos que se configuram em élans comunitários da tribo. Dentro da perspectiva da Pós-modernidade, a pesquisa não objetiva encontrar razões ou justificativas para o comportamento dos jovens da tribo, apenas ponderar algumas temáticas sob a ótica do imaginário, tribalismo urbano e conceitos de corpo dentro do viés já explorado em pesquisas de Comunicação Social. Tendo a rede social Facebook como principal terreno para realização da netnografia, foram analisadas publicações em perfis e fan pages desmistificando a tribo e mostrando as diversas facetas destes jovens. Ao abordar temas polêmicos como bissexualidade, androginia, suicídio e automutilação, o estudo mostra como os emos se colocam socialmente dentre suas lógicas subversivas e contraditórias elucidando outras formas de ver o mundo. Os conceitos de tribalismo urbano de Maffesoli (1987) guiaram os passos deste estudo que se valeu da ótica deste e de outros autores que tratam questões da Pós-modernidade

10-Gbit/s transmission over 300-m standard multimode fiber using multilevel coding and 2-channel WDM

A combination of multilevel coding schemes and simple two-channel wavelength division multiplexing (WDM) at 1300 and 1550 nm was used to transmit an aggregate of 10 Gbit/s over 300 m of multimode fiber that is typical of that employed in current Local Area Networks (LANs). It was shown that this technique could be a simple solution for achieving 10 Gigabit ethernet links over installed multimode fiber building backbones.

The divulgation of hygiene-sanitation matters at the start of Spanish radio (1933-1957)

The work analyse from a journalistic point of view the history radio divulgation of health during the Second Republic and the start of the Franco era. For it, printed sources of the health broadcast conferences have been analysed. The most frequently used radio genre was a combination of informative monologue and monologue opinion. Questions relating to maternal-juvenile health were the most disseminated. In general, the radio language employed responded to the needs for clarity, as well as adapting the message to the target audience. With Francoism, the political slogans were incorporated and the gender discussions were given more importance.

A k-round Elimination Contention Scheme for WLANs

currently in press. This is the first published attempt to engineer QoS into a contention-based MAC layer protocol. The work was based on a cross-layer approach to providing programmability into wireless LANs. The work arose from an EPSRC grant in the "programmable networks" call, with Philips / STM research in Italy (Dr Melpignano). Subsequent follow-on includes the formation of a spin-out company (TOM) based on the idea.