Some of the most challenging issues in data outsourcing scenario are the enforcement of authorization policies and the support of policy updates. Ciphertext-policy attribute-based encryption is a promising cryptographic solution to these issues for enforcing access control policies defined by a data owner on outsourced data. However, the problem of applying the attribute-based encryption in […]
Predictable High-Performance Computing Using Feedback Control and Admission Control
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 […]
A Privacy-Preserving Location Monitoring System for Wireless Sensor Networks
Monitoring personal locations with a potentially untrusted server poses privacy threats to the monitored individuals. To this end, we propose a privacy-preserving location monitoring system for wireless sensor networks. In our system, we design two in-network location anonymization algorithms, namely, resource and quality-aware algorithms, that aim to enable the system to provide high-quality location monitoring […]
Efficient Data Collection in Wireless Sensor Networks with Path-Constrained Mobile Sinks
Recent work shows that sink mobility along a constrained path can improve the energy efficiency in wireless sensor networks. However, due to the path constraint, a mobile sink with constant speed has limited communication time to collect data from the sensor nodes deployed randomly. This poses significant challenges in simultaneously improving the amount of data […]
On Reliable Broadcast in Low Duty-Cycle Wireless Sensor Networks
Broadcast is one of the most fundamental services in wireless sensor networks, where a distinct feature is that sensor nodes may alternate between active and dormant states, so as to conserve energy and extend the network lifetime. Unfortunately, the impact of such cycles has been largely ignored in existing broadcast implementations that adopt the common […]
Fast Data Collection in Tree-Based Wireless Sensor Networks
We investigate the following fundamental question – how fast can information be collected from a wireless sensor network organized as tree? To address this, we explore and evaluate a number of techniques using realistic simulation models under the many-to-one communication paradigm known as convergecast. We first consider time scheduling on a single frequency channel with […]
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 […]