The performance of many cloud-based applications critically depends on the capacity of the underlying datacenter network. A particularly innovative approach to improve the throughput in datacenters is enabled by emerg...
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The performance of many cloud-based applications critically depends on the capacity of the underlying datacenter network. A particularly innovative approach to improve the throughput in datacenters is enabled by emerging optical technologies, which allow to dynamically adjust the physical network topology, both in an oblivious or demand-aware manner. However, such topology engineering, i.e., the operation and control of dynamic datacenter networks, is considered complex and currently comes with restrictions and overheads. We present Duo, a novel demand-aware reconfigurable rack-to-rack datacenter network design realized with a simple and efficient control plane. Duo is based on the well-known de Bruijn topology (implemented using a small number of optical circuit switches) and the key observation that this topology can be enhanced using dynamic ("opportunistic") links between its nodes. In contrast to previous systems, Duo has several desired features: i) It makes effective use of the network capacity by supporting integrated and multi-hop routing (paths that combine both static and dynamic links). ii) It uses a work-conserving queue scheduling which enables out-of-the-box TCP support. iii) Duo employs greedy routing that is implemented using standard IP longest prefix match with small forwarding tables. And iv) during topological reconfigurations, routing tables require only local updates, making this approach ideal for dynamic networks. We evaluate Duo in end-to-end packet-level simulations, comparing it to the state-of-the-art static and dynamic networks designs. We show that Duo provides higher throughput, shorter paths, lower flow completion times for high priority flows, and minimal packet reordering, all using existing network and transport layer protocols. We also report on a proof-of-concept implementation of Duo's control and data plane.
The surge in interest surrounding Software Defined networking (SDN) reflects its status as a groundbreaking and transformative network approach. In large-scale SDN networks, a sole centralized controller cannot fulfil...
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In the rapidly expanding realm of the Internet of Things (IoT), the escalation of sophisticated cyber threats, particularly botnet Distributed Denial of Service (DDoS) attacks, highlights the importance of Intrusion D...
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ISBN:
(纸本)9798350395730;9798350395723
In the rapidly expanding realm of the Internet of Things (IoT), the escalation of sophisticated cyber threats, particularly botnet Distributed Denial of Service (DDoS) attacks, highlights the importance of Intrusion Detection systems (IDS) for maintaining network integrity. IDSs are necessary tools for identifying and mitigating such threats. Consequently, there is a compelling need for a testbed that can facilitate the development and rigorous evaluation of IDS solutions, specifically designed to meet unique requirements and constraints of IoT environments. To bridge this gap, DDOSHIELD-IoT, an IDS testbed, is introduced, aiming to provide a platform for creating and evaluating IDSs within the IoT context. DDOSHIELD-IoT leverages Docker containers and the NS-3 network simulator to accurately mimic IoT environments and traffic. DDOSHIELD-IoT is used to implement and evaluate multiple IDSs. These IDSs leverage different machine learning models, such as K-Means, to detect Mirai botnet DDoS traffic, achieving an accuracy of over 90%. This evaluation highlights DDOSHIELD-IoT's precision as an IDS testbed. Furthermore, DDOSHIELD-IoT provides the capability to measure diverse performance metrics, such as CPU and memory usage. These assessments show DDOSHIELD-IoT's contributions to IoT security practices by offering scalability and reproducibility for enhanced IDS creation and evaluation.
There are a large number of cyber-attacks in the power system, especially the false data injection attack (FDIA). This attack can bypass the traditional bad data detection mechanism (BDDM), and affect the operation of...
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ISBN:
(纸本)9798350321050
There are a large number of cyber-attacks in the power system, especially the false data injection attack (FDIA). This attack can bypass the traditional bad data detection mechanism (BDDM), and affect the operation of the power system. In this paper, for the purpose of guaranteeing the reliable operation of the cyber-physical power system (CPPS), a novel FDIA detection model is developed based on spatial-temporal graph neural network (STGNN). The STGNN can extract the temporal features and spatial features of measurement data simultaneously in the CPPS. Specially, the spatial features and the temporal features are extracted by graph neural network (GNN) and recurrent neural network (RNN), respectively. Simulation results based on IEEE 14-bus system verify the performance of the proposed method.
Model-free reinforcement learning is a promising approach for autonomously solving challenging robotics control problems, but faces exploration difficulty without information about the robot's morphology. The unde...
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ISBN:
(纸本)9798350377712;9798350377705
Model-free reinforcement learning is a promising approach for autonomously solving challenging robotics control problems, but faces exploration difficulty without information about the robot's morphology. The under-exploration of multiple modalities with symmetric states leads to behaviors that are often unnatural and sub-optimal. This issue becomes particularly pronounced in the context of robotic systems with morphological symmetries, such as legged robots for which the resulting asymmetric and aperiodic behaviors compromise performance, robustness, and transferability to real hardware. To mitigate this challenge, we can leverage symmetry to guide and improve the exploration in policy learning via equivariance / invariance constraints. We investigate the efficacy of two approaches to incorporate symmetry: modifying the network architectures to be strictly equivariant / invariant, and leveraging data augmentation to approximate equivariant / invariant actor-critics. We implement the methods on challenging loco-manipulation and bipedal locomotion tasks and compare with an unconstrained baseline. We find that the strictly equivariant policy consistently outperforms other methods in sample efficiency and task performance in simulation. Additionaly, symmetry-incorporated approaches exhibit better gait quality, higher robustness and can be deployed zero-shot to hardware.
A delay-tolerant Kalman filter (DTKF) was proposed in an earlier work of the authors for solving the voltage stability problem in distributed generation systems (DGSs). Several scheduling schemes were compared for the...
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A delay-tolerant Kalman filter (DTKF) was proposed in an earlier work of the authors for solving the voltage stability problem in distributed generation systems (DGSs). Several scheduling schemes were compared for the DGS, where 4 wireless-connected sensor-controller pairs are equally divided into 2 groups and the wireless channel within each group has interference. This brief further generalizes the approach for large-scale DGSs with numerous interconnected distributed energy resources (DERs), where each distributed voltage sensor can perform a multicast to reach multiple controllers and each controller can receive messages from different sensors. In this brief, the aim is to investigate the effects of sensors' scheduling schemes and their multicasting capability on the stability of their DGS. Understanding the dominant factor influencing stability performance (sensor scheduling or multicasting capability) is crucial for making informed decisions and optimizing system design, resource allocation, and performance improvements.
The tracking performance of linear discrete-time systems under quantized iterative learning control is investigated in this paper. An encoding-decoding mechanism is utilized to process the output of the system that is...
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Scholars are enhancing their academic publication for research sharing, professional development, opportunities for collaboration, and so on. They will win academic prestige if their publications have a high citation ...
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ISBN:
(纸本)9783031683114;9783031683121
Scholars are enhancing their academic publication for research sharing, professional development, opportunities for collaboration, and so on. They will win academic prestige if their publications have a high citation index due to the excellent quality. However, some scholars ally with each other to build a group (community) for over-citing each other's papers, in order to increase citation amount fraudulently and further angle for praises and benefits. Such a group demonstrates a tightly linked citation relationship in academic social network (graph). Many existing anomaly group detection methods don't extract and utilize rich semantic information from network and neglect the joint optimization of dense subgraphs discovery and node representation learning, thus the detection performance is degraded. To deal with these issues, an anomalous citation group detection approach GADEC is proposed, which bases on local expansion community discovery andDQN(DeepQnetwork). Semantic information such as research field, paper title, and self-citation is extracted and represented to richen authors' abnormal features. An expansion measure function is enhanced for community discovery, which integrates several key metrics like node transfer similarity, node community membership, abnormal citation degree, etc. GADEC can accurately find the anomaly citation groups by mutually promoting both detection performance of anomalous communities and authors. The experiments on real data sets have demonstrated very good effectiveness of GADEC on the abnormal citation group mining.
Industrial controlsystems (ICS) have specific data requirements in terms of Quality of Service (QoS). Lost or delayed critical data, such as control signals, can damage widespread production, such as machine performa...
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ISBN:
(纸本)9798350398045
Industrial controlsystems (ICS) have specific data requirements in terms of Quality of Service (QoS). Lost or delayed critical data, such as control signals, can damage widespread production, such as machine performance. The problem is compounded in the next-generation Industry 4.0, where the operations will be even less human-dependent, involving multiple organizations. Moreover, the communication aspects across multistakeholders require a disaggregated approach contrary to the current closed ICS architecture. This paper presents a framework for decentralization of ICS called Operations and controlnetworks (OCN) in which 'contracts' are the basic units of abstraction to exchange information with trust and precision between different actors. In the lower layers, High-Precision Communication (HPC) contracts execute control functions with requested service level guarantees in the network. A high-level trusted delegation of tasks is executed as smart contracts using Distributed Ledger Technology (DLT) to enable multi-stakeholder auditability and accountability.
Designing predictive controllers towards optimal closed-loop performance while maintaining safety and stability is challenging. This work explores closed-loop learning for predictive control parameters under imperfect...
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Designing predictive controllers towards optimal closed-loop performance while maintaining safety and stability is challenging. This work explores closed-loop learning for predictive control parameters under imperfect information while considering closed-loop stability. We employ constrained Bayesian optimization to learn a model predictive controller's (MPC) cost function parametrized as a feedforward neural network, optimizing closed-loop behavior as well as minimizing model-plant mismatch. Doing so offers a high degree of freedom and, thus, the opportunity for efficient and global optimization towards the desired and optimal closed-loop behavior. We extend this framework by stability constraints on the learned controller parameters, exploiting the optimal value function of the underlying MPC as a Lyapunov candidate. The effectiveness of the proposed approach is underlined in simulations, highlighting its performance and safety capabilities. Copyright (C) 2024 The Authors.
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