Historically, batch scheduling has dominated the management of High-Performance Computing (HPC) resources. One of the most significant limitations using this approach is an inability to predict both the start time and end time of jobs. Although existing researches such as resource reservation and queue-time prediction partially address this issue, a more predictable HPC system is […]
Optimizing resource conflicts in workflow management systems
Resource allocation and scheduling are fundamental issues in a Workflow Management System (WfMS). Effective resource management in WfMS should examine resource allocation together with task scheduling since these problems impose mutual constraints. Optimization of the one factor is subject to the other constraints and vice versa. Thus, an ideal algorithm should take into account not […]
delay optimal opportunistic scheduling and approximations
This paper considers the design of multiuser opportunistic packet schedulers for users sharing a time-varying wireless channel from performance and robustness points of view. For a simplified model falling in the classical Markov decision process framework, we numerically compute and characterize mean-delay-optimal scheduling policies. The computed policies exhibit radial sum-rate monotonicity: As users’ queues grow […]
SRLG Failure Localization in Optical Networks
We introduce the concepts of monitoring paths (MPs) and monitoring cycles (MCs) for unique localization of shared risk linked group (SRLG) failures in all-optical networks. An SRLG failure causes multiple links to break simultaneously due to the failure of a common resource. MCs (MPs) start and end at the same (distinct) monitoring location(s). They are […]
Communication Cost Minimization in Wireless Sensor and Actor Networks for Road Surveillance
In recent years, wireless sensor and actor networks (WSANs) have been extensively deployed to monitor physical environment and facilitate decision making based on data collected. Emerging applications such as road surveillance highlight some interesting research issues in WSANs, including coordination problems in sensor-actor or actor-actor communications. In this paper, the issue of choosing a set […]
Rumor Riding: Anonymizing Unstructured Peer-to-Peer Systems
Although anonymizing Peer-to-Peer (P2P) systems often incurs extra traffic costs, many systems try to mask the identities of their users for privacy considerations. Existing anonymity approaches are mainly path-based: peers have to pre-construct an anonymous path before transmission. The overhead of maintaining and updating such paths is significantly high. We propose Rumor Riding (RR), a […]
A Spatiotemporal Approach for Secure Range Queries in Tiered Sensor Networks
We target a two-tier sensor network with resource-rich master nodes at the upper tier and resource-poor sensor nodes at the lower tier. Master nodes collect data from sensor nodes and answer the queries from the network owner. The reliance on master nodes for data storage and query processing raises serious concerns about both data confidentiality […]
Distributed Adaptation of Quantized Feedback for Downlink Network MIMO Systems
This paper focuses on quantized channel state information (CSI) feedback for downlink network MIMO systems. Specifically, we propose to quantize and feedback the CSI of a subset of BSs, namely the feedback set. Our analysis reveals the tradeoff between better interference mitigation with large feedback set and high CSI quantization precision with small feedback set. […]
Network Coding Based Privacy Preservation against Traffic Analysis in Multi-hop Wireless Networks
Privacy threat is one of the critical issues in multi-hop wireless networks, where attacks such as traffic analysis and flow tracing can be easily launched by a malicious adversary due to the open wireless medium. Network coding has the potential to thwart these attacks since the coding/mixing operation is encouraged at intermediate nodes. However, the […]
Continuous Neighbor Discovery in Asynchronous Sensor Networks
In most sensor networks, the nodes are static. Nevertheless, node connectivity is subject to changes because of disruptions in wireless communication, transmission power changes, or loss of synchronization between neighboring nodes. Hence, even after a sensor is aware of its immediate neighbors, it must continuously maintain its view, a process we call continuous neighbor discovery. […]