Variable Kinematic Finite Element Formulations Applied to Multi-layered Structures and Multi-field Problems

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Quantized Landau level spectrum and its density dependence

Scanning tunneling microscopy and spectroscopy in magnetic field was used to study Landau quantization in graphene and its dependence on charge carrier density. Measurements were carried out on exfoliated graphene samples deposited on a chlorinated SiO2 thermal oxide which allowed observing the Landau level sequences characteristic of single layer graphene while tuning the density through the Si backgate. Upon changing the carrier density we find abrupt jumps in the Fermi level after each Landau level is filled. Moreover, the Landau level spacing shows a marked increase at low doping levels, consistent with an interaction-induced renormalization of the Dirac cone.Comment: 11 pages, 4 figure

Providing Efficient Privacy-Aware Incentives for Mobile Sensing

Abstract—Mobile sensing relies on data contributed by users through their mobile device (e.g., smart phone) to obtain useful information about people and their surroundings. However, users may not want to contribute due to lack of incentives and concerns on possible privacy leakage. To effectively promote user participation, both incentive and privacy issues should be addressed. Existing work on privacy-aware incentive is limited to special scenario of mobile sensing where each sensing task needs only one data report from each user, and thus not appropriate for generic scenarios in which sensing tasks may require multiple reports from each user (e.g., in environmental monitoring applications). In this paper, we propose a privacy-aware incentive scheme for general mobile sensing, which allows each sensing task to collect one or multiple reports from each user as needed. Besides being more flexible in task management, our scheme has much lower computation and communication cost compared to the existing solution. Evaluations show that, when each node only contributes data for a small fraction of sensing tasks (e.g, due to the incapability or disqualification to generate sensing data for other tasks), our scheme runs at least one order of magnitude faster. I

Structure and organization of chromatin fiber in the nucleus

AbstractEukaryotic genomes are organized hierarchically into chromatin structures by histones. Despite extensive research for over 30years, not only the fundamental structure of the 30-nm chromatin fiber is being debated, but the actual existence of such fiber remains hotly contested. In this review, we focus on the most recent progress in elucidating the structure of the 30-nm fiber upon in vitro reconstitution, and its possible organization inside the nucleus. In addition, we discuss the roles of linker histone H1 as well as the importance of specific nucleosome-nucleosome interactions in the formation of the 30-nm fiber. Finally, we discuss the involvement of structural variations and epigenetic mechanisms available for the regulation of this chromatin form

Routing in Socially Selfish Delay Tolerant Networks

Abstract—Existing routing algorithms for Delay Tolerant Networks (DTNs) assume that nodes are willing to forward packets for others. In the real world, however, most people are socially selfish; i.e., they are willing to forward packets for nodes with whom they have social ties but not others, and such willingness varies with the strength of the social tie. Following the philosophy of design for user, we propose a Social Selfishness Aware Routing (SSAR) algorithm to allow user selfishness and provide better routing performance in an efficient way. To select a forwarding node, SSAR considers both users ’ willingness to forward and their contact opportunity, resulting in a better forwarding strategy than purely contact-based approaches. Moreover, SSAR formulates the data forwarding process as a Multiple Knapsack Problem with Assignment Restrictions (MKPAR) to satisfy user demands for selfishness and performance. Trace-driven simulations show that SSAR allows users to maintain selfishness and achieves better routing performance with low transmission cost. I