Sriram Chellappan

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In this paper, we study the issue of mobility based sensor networks deployment. The distinguishing feature of our work is that the sensors in our model have limited mobilities. More specifically, the mobility in the sensors we consider is restricted to a flip, where the distance of the flip is bounded. Given an initial deployment of sensors in a field, our(More)
An important phase of sensor networks operation is deployment of sensors in the field of interest. Critical goals during sensor networks deployment include coverage, connectivity, load balancing, etc. A class of work has recently appeared, where mobility in sensors is leveraged to meet deployment objectives. In this paper, we study deployment of sensor(More)
Recent active worm propagation events show that active worms can spread in an automated fashion and flood the Internet in a very short period of time. Due to the recent surge of Peer-to-Peer (P2P) systems with large numbers of users, P2P systems can be a potential vehicle for the active worms to achieve fast worm propagation in the Internet. In this paper,(More)
In this paper, we study the issue of sensor network 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)
State-of-the-art in-home activity recognition schemes with wearable devices are mostly capable of detecting coarse-grained activities (sitting, standing, walking, or lying down), but can't distinguish complex activities (sitting on the floor versus the sofa or bed). Such schemes often aren't effective for emerging critical healthcare applications -- 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)
0140-3664/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.comcom.2008.08.008 * Corresponding author. Tel.: +1 214 208 5951. E-mail addresses: (W. Yu), ch pan), (X. Wang), xuan@cs Active worms continue to pose major threats to the security of today’s Internet. This is due to the ability of active worms to(More)
Distributed denial of service (DDoS) attacks are currently major threats to communication in the Internet. A secure overlay services (SOS) architecture has been proposed to provide reliable communication between clients and a target under DDoS attacks. The SOS architecture employs a set of overlay nodes arranged in three hierarchical layers that controls(More)
In many Wireless Sensor Networks (WSNs), providing end to end secure communications between sensors and the sink is important for secure network management. While there have been many works devoted to hop by hop secure communications, the issue of end to end secure communications is largely ignored. In this paper, we design an end to end secure(More)