534 research outputs found

    Product, Processes and Organization Architectures Modeling : from strategic expectations to strategic competences.

    No full text
    International audienceComplex systems design and especially automotive design is facing continuous technological evolution that needs stronger integration. In this paper, a method for representing system architecture is presented. This method is based on dependencies and constraints propagation which allows us to focus on the co-evolution of product, organization and processes domains

    Using machine learning on V2X communications data for VRU collision prediction

    Get PDF
    The datasets presented in this study are available in Zenodo at https://doi.org/10.5281/zenodo.7376770 (accessed on 16 December 2022), reference number [23]. These datasets are the raw data used for the testing and training of the ML algorithms in this work.Intelligent Transportation Systems (ITSs) are systems that aim to provide innovative services for road users in order to improve traffic efficiency, mobility and safety. This aspect of safety is of utmost importance for Vulnerable Road Users (VRUs), as these users are typically more exposed to dangerous situations, and their vehicles also possess poorer safety mechanisms when in comparison to regular vehicles on the road. Implementing automatic safety solutions for VRU vehicles is challenging since they have high agility and it can be difficult to anticipate their behavior. However, if equipped with communication capabilities, the generated Vehicle-to-Anything (V2X) data can be leveraged by Machine Learning (ML) mechanisms in order to implement such automatic systems. This work proposes a VRU (motorcyclist) collision prediction system, utilizing stacked unidirectional Long Short-Term Memorys (LSTMs) on top of communication data that is generated using the VEINS simulation framework (coupling the Simulation of Urban MObility (SUMO) and Network Simulator 3 (ns-3) tools). The proposed system performed well in two different scenarios: in Scenario A, it predicted 96% of the collisions, averaging 4.53 s for Average Prediction Time (s) (APT) and with a Correct Decision Percentage (CDP) of 41% and 78 False Positives (FPs); in Scenario B, it predicted 95% of the collisions, with a 4.44 s APT, while the CDP was 43% with 68 FPs. The results show the effectiveness of the approach: using ML methods on V2X data allowed the prediction of most of the simulated accidents. Nonetheless, the presence of a relatively high number of FPs does not allow for the usage of automatic safety features (e.g., emergency breaking in the passenger vehicles); thus, collision avoidance must be achieved manually by the drivers.This work has been supported by national funds through FCT—Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020

    Design of a communications interface for a very high performance computer

    Get PDF
    PetaFLOPS computing power is the newest goal of Federal Government agencies, in the increasingly active supercomputer field. To obtain this performance goal by the year 2007, sophisticated parallel processing designs are required. To effectively create network interfaces/routers for interprocessor communications in such computer systems, it requires optimal hardware and software codesigns. An interface is presented for the NJIT New Millennium Computing Point Design, a system that targets 100 TeraFLOPS performance by the year 2005. The router handles store-and-forward switching and wormhole routing for the system

    An Analysis of Botnet Attack for SMTP Server using Software Define Network (SDN)

    Get PDF
    SDN architecture overwhelms traditional network architectures by software abstraction for a centralize control of the entire networks. It provides manageable network infrastructures that consist millions of computing devices and software. In this work, we present multi-domain SDNs architecture with an integration of Spamhaus server. The proposed method allows SDN Controllers to update the Spamhaus server with latest detected spam signatures. It can help to prevent any spam email from entering others SDN domains. We also discussed a method for analyzing SMTP spam frames using a decision tree algorithm. We use Mininet tool to simulate the multi-domain SDNs with the Spamhaus server. The simulation results show that a packet Retransmission Timeout (RTO) between server and client can help to detect the SMTP spam frames

    Multithreading Aware Hardware Prefetching for Chip Multiprocessors

    Get PDF
    To take advantage of the processing power in the Chip Multiprocessors design, applications must be divided into semi-independent processes that can run concur- rently on multiple cores within a system. Therefore, programmers must insert thread synchronization semantics (i.e. locks, barriers, and condition variables) to synchro- nize data access between processes. Indeed, threads spend long time waiting to acquire the lock of a critical section. In addition, a processor has to stall execution to wait for load data accesses to complete. Furthermore, there are often independent instructions which include load instructions beyond synchronization semantics that could be executed in parallel while a thread waits on the synchronization semantics. The conveniences of the cache memories come with some extra cost in Chip Multiprocessors. Cache Coherence mechanisms address the Memory Consistency problem. However, Cache Coherence adds considerable overhead to memory accesses. Having aggressive prefetcher on different cores of a Chip Multiprocessor can definitely lead to significant system performance degradation when running multi-threaded applications. This result of prefetch-demand interference when a prefetcher in one core ends up pulling shared data from a producing core before it has been written, the cache block will end up transitioning back and forth between the cores and result in useless prefetch, saturating the memory bandwidth and substantially increase the latency to critical shared data. We present a hardware prefetcher that enables large performance improvements from prefetching in Chip Multiprocessors by significantly reducing prefetch-demand interference. Furthermore, it will utilize the time that a thread spends waiting on syn- chronization semantics to run ahead of the critical section to speculate and prefetch independent load instruction data beyond the synchronization semantics

    Supporting unified distributed management and autonomic decisions: design, implementation and deployment

    Get PDF
    Nowadays, the prevailing use of networks based on traditional centralized management systems reflects on a fast increase of the management costs. The growth in the number of network equipments and services reinforces the need to distribute the management responsibilities throughout the network devices. In this approach, each device executes common network management functionalities, being part of the overall network management platform. In this paper, we present a Unified Distributed Network Management (UDNM) framework that provides a unified (wired and wireless) management network solution, where further different network services can take part of this infrastructure, e.g., flow monitoring, accurate routing decisions, distributed policies dissemination, etc. This framework is divided in two main components: (A) Situation awareness, which sets up initial information through bootstrapping, discovery, fault-management process and exchange of management information; (B) Autonomic Decision System (ADS) that performs distributed decisions in the network with incomplete information. We deploy the UDNM framework in a testbed which involves two cities ( ≈ ≈ 250 km between), different standards (IEEE 802.3, IEEE 802.11 and IEEE 802.16e) and network technologies, such as, wired virtual grid, wireless ad-hoc gateways, ad-hoc mobile access devices. The UDNM framework integrates management functionalities into the managed devices, proving to be a lightweight and easy-respond framework. The performance analysis shows that the UDNM framework is feasible to unify devices management functionalities and to take accurate decisions on top of a real network.info:eu-repo/semantics/publishedVersio
    • …
    corecore