Open Access. Powered by Scholars. Published by Universities.®

Computer and Systems Architecture Commons™

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Computer and Systems Architecture

An Optimized And Scalable Blockchain-Based Distributed Learning Platform For Consumer Iot, Zhaocheng Wang, Xueying Liu, Xinming Shao, Abdullah Alghamdi, Md. Shirajum Munir, Sujit Biswas Jan 2023

An Optimized And Scalable Blockchain-Based Distributed Learning Platform For Consumer Iot, Zhaocheng Wang, Xueying Liu, Xinming Shao, Abdullah Alghamdi, Md. Shirajum Munir, Sujit Biswas

School of Cybersecurity Faculty Publications

Consumer Internet of Things (CIoT) manufacturers seek customer feedback to enhance their products and services, creating a smart ecosystem, like a smart home. Due to security and privacy concerns, blockchain-based federated learning (BCFL) ecosystems can let CIoT manufacturers update their machine learning (ML) models using end-user data. Federated learning (FL) uses privacy-preserving ML techniques to forecast customers' needs and consumption habits, and blockchain replaces the centralized aggregator to safeguard the ecosystem. However, blockchain technology (BCT) struggles with scalability and quick ledger expansion. In BCFL, local model generation and secure aggregation are other issues. This research introduces a novel architecture, emphasizing …


Decision Strategies For A P2p Computing System, Grzegorz Chmaj, Krzysztof Walkowiak Jan 2012

Decision Strategies For A P2p Computing System, Grzegorz Chmaj, Krzysztof Walkowiak

Electrical & Computer Engineering Faculty Research

Peer-to-Peer (P2P) computing (also called ‘public-resource computing’) is an effective approach to perform computation of large tasks. Currently used P2P computing systems (e.g., BOINC) are most often centrally managed, i.e., the final result of computations is created at a central node using partial results – what may be not efficient in the case when numerous participants are willing to download the final result. In this paper, we propose a novel approach to P2P computing systems. We assume that results can be delivered to all peers in a distributed way using three types of network flows: unicast, Peer-to-Peer and anycast. We …


Random Approach To Optimization Of Overlay Public-Resource Computing Systems, Grzegorz Chmaj, Krzysztof Walkowiak Mar 2010

Random Approach To Optimization Of Overlay Public-Resource Computing Systems, Grzegorz Chmaj, Krzysztof Walkowiak

Electrical & Computer Engineering Faculty Research

The growing need for computationally demanding systems triggers the development of various network-oriented computing systems organized in a distributed manner. In this work we concentrate on one kind of such systems, i.e. public-resource computing systems. The considered system works on the top of an overlay network and uses personal computers and other relatively simple electronic equipment instead of supercomputers. We assume that two kinds of network flows are used to distribute the data in the public-resource computing systems: unicast and peer-to-peer. We formulate an optimization model of the system. After that we propose random algorithms that optimize jointly the allocation …


Proactive Service Migration For Long-Running Byzantine Fault-Tolerant Systems, Wenbing Zhao, H. Zhang Apr 2009

Proactive Service Migration For Long-Running Byzantine Fault-Tolerant Systems, Wenbing Zhao, H. Zhang

Electrical and Computer Engineering Faculty Publications

A proactive recovery scheme based on service migration for long-running Byzantine fault-tolerant systems is described. Proactive recovery is an essential method for ensuring the long-term reliability of fault-tolerant systems that are under continuous threats from malicious adversaries. The primary benefit of our proactive recovery scheme is a reduced vulnerability window under normal operation. This is achieved in two ways. First, the time-consuming reboot step is removed from the critical path of proactive recovery. Second, the response time and the service migration latency are continuously profiled and an optimal service migration interval is dynamically determined during runtime based on the observed …


Preliminary Study On Optimization Of Data Distribution In Resource Sharing Systems, Grzegorz Chmaj, Krzysztof Walkowiak Aug 2008

Preliminary Study On Optimization Of Data Distribution In Resource Sharing Systems, Grzegorz Chmaj, Krzysztof Walkowiak

Electrical & Computer Engineering Faculty Research

Grid structures are increasingly considered as very convergent with peer-to-peer networks. This paper presents a model of network acting both as grid and peer-to-peer network, used for data computation and distribution. Presented PPLC algorithm is a complete solution for both grid and peer-to-peer points of view. Problem formulation is presented, as well as solution heuristic algorithm and research results.


Dynamic Routing Structure For An Rti Taking An Evolutionary Approach Towards Optimization, Matthew Ryan Davis Jul 2007

Dynamic Routing Structure For An Rti Taking An Evolutionary Approach Towards Optimization, Matthew Ryan Davis

Computational Modeling & Simulation Engineering Theses & Dissertations

The Runtime Infrastructure (RTI) is the common communication framework that High Level Architecture (HLA) simulations incorporate to exchange data. By abstracting the network communication layer from simulation, a common protocol for information exchange is achieved, allowing any RTI- based simulation to exchange data with any other. Such commonality can bring a limitation upon the network infrastructure, enforcing all federates to agree on the same communication policy. While this static network structure is not always the case, an optimal choice would be to adhere to the dynamic properties of a network. Static network configurations deny federates the ability to dynamically avoid …


Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng Jan 2006

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …


Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga Oct 2004

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …


Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere Jan 2001

Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere

Computer Science Faculty Publications and Presentations

A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine-grain reallocation of …


Application Of Control Theory To Modeling And Analysis Of Computer Systems, Molly H. Shor, Kang Li, Jonathan Walpole, David Steere, Calton Pu Jun 2000

Application Of Control Theory To Modeling And Analysis Of Computer Systems, Molly H. Shor, Kang Li, Jonathan Walpole, David Steere, Calton Pu

Computer Science Faculty Publications and Presentations

Experimentally, we show that Transmission Control Protocol (TCP)’s congestion control algorithm results in dynamic behavior similar to a stable limit cycle (attractor) when data from TCP flow into a fixed-size buffer and data is removed from the buffer at a fixed service rate. This setup represents how TCP buffers packets for transmission onto the network, with the network represented by a fixed-size buffer with a fixed service rate. The closed trajectory may vary slightly from period to period due to the discrete nature of computer systems. The size of the closed trajectory is a function of the network’s buffer size …


Implementation And Performance Of Error Correction Codes For High-Speed Computer Networks, Jochen Spengler Sep 1999

Implementation And Performance Of Error Correction Codes For High-Speed Computer Networks, Jochen Spengler

Dissertations and Theses

During the transmission of data there is always a possibility that errors occur and some pieces are modified. If the receiver detects an error it either sends a request for retransmission or, like in networks using Ethernet, it does not send an acknowledgment for the erroneous frame. In this case the sender waits a certain time and retransmits the frame. With the development of faster computer networking hardware and the need for more real-time applications, these errors have become a major concern. Long retransmission latencies and the need for large memories for buffering drive the development of more reliable network …