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Law enforcement agencies need the ability to conduct electronic surveillance to combat crime, terrorism, or other malicious activities exploiting the Internet. However, the proliferation of anonymous communication systems on the Internet has posed significant challenges to providing such traceback capability. In this paper, we develop a new class of flow(More)
It is well-known that placing disks in the triangular lattice pattern is optimal for achieving full coverage on a plane. With the emergence of wireless sensor networks, however, it is now no longer enough to consider coverage alone when deploying a wireless sensor network; connectivity must also be con-sidered. While moderate loss in coverage can be(More)
—Small talk is an important social lubricant that helps people, especially strangers, initiate conversations and make friends with each other in physical proximity. However, due to difficulties in quickly identifying significant topics of common interest, real-world small talk tends to be superficial. The mass popularity of mobile phones can help improve(More)
—Falls are a major health risk that diminish the quality of life among elderly people. With the elderly population surging, especially with aging " baby boomers " , fall detection becomes increasingly important. However, existing commercial products and academic solutions struggle to achieve pervasive fall detection. In this paper, we propose utilizing(More)
—This paper presents the general approach, design, implementation , and evaluation of NetCamo, which is a system to prevent traffic analysis in systems with real-time requirements. Integrated support for both security and real-time is becoming necessary for computer networks that support mission critical applications. This study focuses on how to integrate(More)
Falls are a major health risk that diminishes the quality of life among the elderly people. The importance of fall detection increases as the elderly population surges, especially with aging ''baby boomers''. However, existing commercial products and academic solutions all fall short of pervasive fall detection. In this paper, we propose utilizing mobile(More)
In this paper, we study the issue of sensor networks deployment using limited mobility sensors. By limited mobility, we mean that the maximum distance that sensors are capable of moving to is limited. Given an initial deployment of limited mobility sensors in a field clustered into multiple regions, our deployment problem is to determine a movement plan for(More)
—In this paper, we address a Resource Constrained Lifetime Problem in sensor networks in an operating environment subject to physical node destructions. Specifically, given a limited number of sensors, our goal is to maximize the network lifetime and derive the deployment plan of the nodes to maximize the lifetime under physical node destructions. The(More)
—In wireless sensor networks, multiple-coverage, in which each point is covered by more than one sensor, is often required to improve detection quality and achieve high fault tolerance. However, finding optimal patterns that achieve multiple-coverage in a plane remains a long-lasting open problem. In this paper, we first derive the optimal deployment(More)
In this paper, we propose deployment patterns to achieve full coverage and three-connectivity, and full coverage and five-connectivity under different ratios of sensor communication range (denoted by Rc) over sensing range (denoted by Rs) for wireless sensor networks (WSNs). We also discover that there exists a hexagon-based universally elemental pattern(More)