One-to-many node-disjoint paths in (n,k)-star graphs

We present an algorithm which given a source node and a set of n−1 target nodes in the (n,k)-star graph Sn,k, where all nodes are distinct, builds a collection of n−1 node-disjoint paths, one from each target node to the source. The collection of paths output from the algorithm is such that each path has length at most 6k−7, and the algorithm has time complexity O(k2n2)

An extensive English language bibliography on graph theory and its applications

Bibliography on graph theory and its application

A planetary nervous system for social mining and collective awareness

We present a research roadmap of a Planetary Nervous System (PNS), capable of sensing and mining the digital breadcrumbs of human activities and unveiling the knowledge hidden in the big data for addressing the big questions about social complexity. We envision the PNS as a globally distributed, self-organizing, techno-social system for answering analytical questions about the status of world-wide society, based on three pillars: social sensing, social mining and the idea of trust networks and privacy-aware social mining. We discuss the ingredients of a science and a technology necessary to build the PNS upon the three mentioned pillars, beyond the limitations of their respective state-of-art. Social sensing is aimed at developing better methods for harvesting the big data from the techno-social ecosystem and make them available for mining, learning and analysis at a properly high abstraction level. Social mining is the problem of discovering patterns and models of human behaviour from the sensed data across the various social dimensions by data mining, machine learning and social network analysis. Trusted networks and privacy-aware social mining is aimed at creating a new deal around the questions of privacy and data ownership empowering individual persons with full awareness and control on own personal data, so that users may allow access and use of their data for their own good and the common good. The PNS will provide a goal-oriented knowledge discovery framework, made of technology and people, able to configure itself to the aim of answering questions about the pulse of global society. Given an analytical request, the PNS activates a process composed by a variety of interconnected tasks exploiting the social sensing and mining methods within the transparent ecosystem provided by the trusted network. The PNS we foresee is the key tool for individual and collective awareness for the knowledge society. We need such a tool for everyone to become fully aware of how powerful is the knowledge of our society we can achieve by leveraging our wisdom as a crowd, and how important is that everybody participates both as a consumer and as a producer of the social knowledge, for it to become a trustable, accessible, safe and useful public good.Seventh Framework Programme (European Commission) (grant agreement No. 284709

Structure and dynamics of nanoconfined water and aqueous solutions

This review is devoted to discussing recent progress on the structure, thermodynamic, reactivity, and dynamics of water and aqueous systems confined within different types of nanopores, synthetic and biological. Currently, this is a branch of water science that has attracted enormous attention of researchers from different fields interested to extend the understanding of the anomalous properties of bulk water to the nanoscopic domain. From a fundamental perspective, the interactions of water and solutes with a confining surface dramatically modify the liquid's structure and, consequently, both its thermodynamical and dynamical behaviors, breaking the validity of the classical thermodynamic and phenomenological description of the transport properties of aqueous systems. Additionally, man-made nanopores and porous materials have emerged as promising solutions to challenging problems such as water purification, biosensing, nanofluidic logic and gating, and energy storage and conversion, while aquaporin, ion channels, and nuclear pore complex nanopores regulate many biological functions such as the conduction of water, the generation of action potentials, and the storage of genetic material. In this work, the more recent experimental and molecular simulations advances in this exciting and rapidly evolving field will be reported and critically discussed

Nanoscale Semiconductor Materials and Devices Employing Hybrid 1D and 2D Structures for Tunable Electronic and Photonic Applications

Das, Suprem R. Ph.D., Purdue University, December 2013. Nanoscale Semiconductor Materials and Devices employing Hybrid 1D and 2D structures for Tunable Electronic and Photonic Applications. Major Professor: Dr. David B. Janes. Continued miniaturization of microelectronic devices over past decades has brought the device feature size towards the physical limit. Likewise, enormous `waste energy\u27 in the form of self-heating in almost all of the electronic and optoelectronic devices needs an `energy-efficient low power\u27 and `high performance\u27 material as well as device with alternate geometry. III-V semiconductors are proven to be one of the alternate systems of materials for various applications including CMOS devices, low power and high performance transistor devices, power transistors, as well as thermoelectric applications. InSb, being the bulk semiconductor with lowest bandgap, highest mobility, low effective mass, and highest spin–orbit coupling has potential of providing numerous novel applications. Also, InSb in nanowire form has not been explored in many aspects. First part of this thesis explores the possibility of growing InSb nanowires using solution based electrodeposition technique followed by field effect transistor studies. InSb nanowires have recently shown very promising magneto-transport properties at low temperatures and with magnetic field due to its high spin orbit coupling. This thesis demonstrates initial low temperature device studies on hybrid devices with InSb channel and superconducting electrodes (aluminum). In the last section of InSb nanowire studies, the thesis explores hierarchial branched nanowires with different diameters that demonstrate near unity optical absorption in UV–VIS regime and wavelength dependent absorption in near infrared (NIR) regime. A photonic coupling model was developed to explain the phenomena. The unique photonic properties of the structurally tailored branched nanowire arrays could be used to devise new types of photonic, optoelectronics and/or photovoltaic devices. The second half of the thesis explores another class of hybrid material structure involving 2D semiconductor/semimetal ‘Graphene’ and 1D silver nanowires. While the ultimate goal was to push the limit of ‘transparent and flexible technology’ the thesis, also critically explores the physics of percolation doping to beat the conduction–transparency bottleneck. The thesis demonstrates theory of ‘co-percolation’ involving two individual networks in which the invidual\u27s weakness is circumvented by the other. This study not only applies to the particular system chosen but also could be readily applied to any large scale 2D–1D nanoscale systems such as layered semiconductors, topological insulators and nanowires