ISEP – CISTER – Outros
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- Response Time Analysis for Fixed-Priority Tasks with Multiple Probabilistic ParametersPublication . Maxim, Dorin; Cucu-Grosjean, LilianaWe consider a system of n synchronous tasks {t1, t2, ……tn} to be scheduled on one processor according to a preemptive fixed-priority task-level scheduling policy. Without loss of generality, we consider that ti has a higher priority than tj for i
- A module for the XDense architecture in ns-3Publication . Loureiro, João; Albano, Michele; Cerqueira, Tiago; Rangarajan, Raghuraman; Tovar, EduardoThe acquisition of data regarding some dynamic phenomena can require extremely dense deployments of sensors and high sampling rates. We propose XDense [1], a wired mesh grid sensor network architecture (see Figure 1a) tailored for scenarios that benefit from thousands of sensors per square meter. XDense has scalable network topology and it enables complex feature extraction in real-time from the observed phenomena, by exploiting distributed processing capabilities and inter-node communication, the latter being represented in Figure 1b.
- A module for the FTT-SE protocol in ns-3Publication . Oliveira, Fábio; Martínez, Ricardo Garibay; Cerqueira, Tiago; Albano, Michele; Ferreira, Luís LinoThe Flexible Time Triggered Switched Ethernet (FFT-SE) protocol allows the concurrent transmission of both real-time (i.e., synchronous and asynchronous) traffic and best-effort traffic over Ethernet. Communications within an FTT-SE network are done based on the reservation of fixed duration time slots called Elementary Cycles (ECs). The construction of the ECs and the media access control are managed by the master node. The FTTSE protocol uses the master/slave paradigm, in which the slave nodes make petitions for transmission to the master node, and the master node grants them access for transmission according to the scheduling algorithm chosen by the master node (e.g., Rate Monotonic, Earliest Deadline First, etc.).
- A module for Data Centric Storage in ns-3Publication . Albano, Michele; Cerqueira, Tiago; Chessa, StefanoManagement of data in large wireless sensor networks presents many hurdles, mainly caused by the limited energy available to the sensors, and by the limited knowledge of the sensors regarding the topology of the network. The first problem has been targeted by the introduction of in-network storage of sensed data, which can save much communication energy. The second issue found some relief with the introduction of geographical protocols that do not need knowledge regarding the network at large. Data Centric Storage systems such as QNiGHT [1][2] assume that each sensor knows its own geographical location, and they use geographical routing such as the Enhanced Greedy Perimeter Stateless Routing (EGPSR) protocol, sketched in Figure 1, to deliver packets to the sensor closest to a given point in the sensing area.
- Automated resource allocation for T-ResPublication . Gaur, Shashank; Rangarajan, Raghuraman; Tovar, EduardoThis paper presents a demo of an extension developed to support an existing programming abstraction for IoT: mTRes. mT-Res is an extension of the T-Res programming abstraction, which allows users to write applications using a web framework independent of resources. The paper describes an automated mechanism for allocate resources to such applications and adapt to changes in those resources.
- Run-Time Monitoring Environments for Real-Time and Safety Critical SystemsPublication . Nelissen, Geoffrey; Carvalho, Humberto; Pereira, David; Tovar, EduardoIn this work, we present four different implementations of a run-time monitoring framework suited to real-time and safety critical systems. Two implementations are written in Ada and follow the Ravenscar profile, which make them particularly suited to the development of high integrity systems. The first version is available as a standalone library for Ada programs while the second has been integrated in the GNAT run-time environment and instruments the ORK+ micro-kernel. Information on the task scheduling events, directly originating from the kernel, can thus be used by the monitors to check if the system follows all its requirements. The third implementation is a standalone library written in C++ that can be used in any POSIX compliant run-time environment. It is therefore compatible with the vast majority of operating systems used in embedded systems. The last implementation is a loadable kernel module for Linux. It has for main advantage to be able to enforce complete space partitioning between the monitors and the monitored applications. It is therefore impossible for memory faults to propagate and corrupt the state of the monitors.
- Timing Analysis Solutions for Multicore SystemsPublication . Pinho, Luís MiguelA generic framework, integrating models, tools and system software, to parallelize applications with high performance and real-time requirements
- Guest editorial: real-time networks and systemsPublication . Pinho, Luis Miguel; Faucou, SébastienThis section of Real-Time Systems provides extended journal versions of the outstanding work presented at the 24th International Conference on Real-Time Networks and Systems (RTNS 2016), held at Université de Bretagne Occidentale (November 2016, in Brest, France). The purpose of RTNS is to provide a venue for sharing new ideas, experiences and information among academic researchers, developers and service providers in the field of real-time systems and networks. The 24th edition of the conference continued the established series with a rich program of 34 papers (out of 75 submissions), with a diversity of topics, such as transactions and distributed systems, network analysis, synchronous dataflow graphs, scheduling and schedulability, periodic systems and control, network optimization, many-core and networks-on-chip, multicore scheduling, timing analysis, parallelism, a clear demonstration of the broad scope of real-time systems and networks research. The special issue consists of four papers that cover various areas, from high level system design and optimization to low level timing analysis of computer systems and networks, which have undergone a rigorous peer-review process according to the journal’s high standards.
- System and method for operating a follower vehicle in a vehicle platoonPublication . Li, Zhiwu; Karoui, Oussama; Koubaa, Anis; Khalgui, Mohamed; Guerfala, Emna; Tovar, Eduardo; Wu, NaiqiA method for operating a follower vehicle in a vehicle platoon includes determining, during operation, whether the follower vehicle is operating in a normal state or an abnormal state based on an operation condition of a component of the follower vehicle, or a communication between the follower vehicle and a preceding vehicle in the vehicle platoon. The method further includes selecting a first control mode if the follower vehicle is in the normal state and a second control mode if the follower vehicle is in the abnormal state so as to control movement of the follower vehicle using the selected control mode. In the first control mode, the follower vehicle uses communication data received from the preceding vehicle in the vehicle platoon to control its movement. In the second control mode, the follower vehicle uses data obtained by one or more of its sensors to control its movement.
- Guest Editorial Special Issue on Communications Technologies and Infrastructures for Smart e-Health SystemsPublication . Ullah, Sana; Pedrycz, Witold; Karagiannidis, George K.; Chao, Han-Chieh; Gacek, Adam; Verikoukis, ChristosThe papers in included in this special issue examines new and novel communication methods for smart e-health systems. Recent developments in the healthcare domain have facilitated the integration of several technologies for smart, cost-effective, reliable, and pervasive health monitoring of chronic diseases. Current research efforts focus on developing real-time communication methods, mostly for body area networks (BANs) that are used to deliver patients´ information effectively. These efforts are limited to communication within a BAN; however, less attention has been paid to connect multiple BANs to remote servers in real time. In addition, there is a limited study on the integration of BANs with different technologies including mobile cloud computing—a technology that may assist in storing and processing the huge amount of BAN data at competitive costs. Machine to machine is also considered to be a valuable paradigm in delivering BAN data to a remote server/cloud for further analysis. This may assist in reducing risks and cost of remote health monitoring. Unlike conventional research in BANs where researchers focused on individual networks, there is a need to develop innovative communication methods with a focus on complete and smart e-health systems. This smart e-health system must integrate the aforementioned technologies with multiple BANs, and provide rich healthcare services to end users. It calls for research on versatile topics ranging from physical and medium access control protocols to BANs coexistence, traffic characterization, cloud resource allocation, and cloud monitoring and maintenance.