Description: Abstract: This paper presents an innovative unsupervised method for automatic sentence extraction using graph-based ranking algorithms. We evaluate the method in the context of a text summarization task, and show that the results obtained compare favorably with previously published results on established benchmarks.

Description: This technical report addresses how to hide secrets from an operating system. Abstract: The adversary model for digital rights management is much more powerful than for the traditional security scenarios. The adversary has complete control of the computing node - supervisory privileges, physical as well as architectural object observational capabilities. In essence, this makes the operating system (or any other layer around the architecture) itself the adversary. The repercussions of this observation are severe. It creates a need to "keep secrets" from the operating system. We argue for the need to keep secrets from the OS in hardware. This concept is demonstrated through architectural support for the obfuscation of dynamic address traces on the memory bus. The objective is to leak as little information about the executed program sequence as possible. This is done by handing over many of the virtual memory management responsibilities from the operating system to an architecturally isolated hardware black-box (VM black-box). The authors provide a detailed design for the VM blackbox and some microarchitecture level simulation derived performance data. We also describe a compiler directed prefetch scheme that uses both instruction and data prefetches to obfuscate the address traces on the address bus between on-chip ...

Description: This paper discusses hybrid energy-aware synchronization algorithm in wireless sensor networks. Abstract: We present a time synchronization scheme for wireless sensor networks that aims to conserve sensor battery power while maintaining network connectivity for as long as possible. The proposed method creates a hierarchical tree by flooding the sensor network from a designated source point. It then uses a hybrid algorithm derived from the Timing-sync Protocol for Sensor Networks (TSPN) and the Reference Broadcast Synchronization Method (RBS) to periodically synchronize sensor clocks by minimizing the number of required transmissions. In multi-hop ad-hoc networks, a depleted sensor will drop information from all other sensors that route data through it, decreasing the physical area being monitored by the network. It is therefore imperative that time synchronization schemes are aware of the number of sensors being used at any given time. The proposed method uses several techniques and thresholds to maintain network connectivity. A new source point is chosen when the current one's battery power reaches a designated energy threshold. The network is also re-flooded whenever the number of used sensors drops below another threshold. We implement and show that their scheme can provide significant power savings over both TPSN and RBS; the ...

Description: This presentation introduces code division multiple access (CDMA) networks, average and actual interference models, optimized capacity, and the 2D Gaussian user model.

Description: This paper discusses indoor propagation modeling. Abstract: The purpose of this study is to characterize the indoor channel for 802.11 wireless local area networks at 2.4 GHz frequency. This work presents a channel model based on measurements conducted in commonly found scenarios in buildings. These scenarios include closed corridor, open corridor, classroom, and computer lab. Path loss equations are determined using log-distance path loss model and log-normal shadowing. The Chi-square test statistic values for each access point are calculated to prove that the observed fading is a normal distribution at 5% significance level. A numerical analysis of measurements in each scenario was conducted and the study determined equations that describe path loss for each scenario.