Whodunit ! Assessing Copyright Liability in Cyburbia: Positing Solutions to Curb the Menace of Copyrighted ‘File Sharing’ Culture

The electronic age has kick started the information boom and with an everincreasing pace, it has begun to spread its canvas to engulf mankind as its greatest beneficiary andperhaps its most susceptible slave. This is evident from the universal phenomenon of copyrightedfile sharing culture promoted by P2P technologies. Indeed, the P2P architecture poses a threat to theentertainment and software industries which stand on the legislative guarantee of copyright laws.But technological advances have not only caused legislative obsolescence , but have also altered thedynamics of information exchange in the online environment. The word ‘State’ seems to have lostits meaning somewhere. Therefore, there is a pressing need on us, as an International society, todevise alternative solutions and approaches to substantially curb the abuse of digital copyrightedworks, for copyright laws to have any meaning. It is this global concern which gives birth to thispaper

Solid Freeform Fabrication of Functional Silicon Nitride Ceramics by Laminated Object Manufacturing 1

The processing of silicon nitride (Si3N4) structural ceramics by Laminated Object Manufacturing (LOM) using ceramic tape preforms was investigated. The key processing stages involved green shape formation (which used the LOM process), followed by the burnout of all organics, and final densification by pressureless sintering. Two material systems were considered. These were a) monolithic Si3N4 and b) a preceramic polymer infiltrated Si3N4. The raw materials for the process were tape preforms of Si3N4, which were fabricated by standard tape casting techniques. Mechanical property data obtained for the LOM processed Si3N4 showed high strength and fracture toughness values. The room temperature and high temperature (1260 o C) flexural strengths were in the range of 700-900 MPa and 360-400 MPa, respectively. The fracture toughness averaged from 5.5-7.5 MPa.m1/2. These strength and fracture toughness values are comparable to those reported for conventionally prepared Si3N4 ceramics. Thus, this research demonstrated that the LOM technique is a viable method for preparing functional Si3N4 ceramics with good physical and mechanical properties.Mechanical Engineerin

Phases and quantum phase transitions in the anisotropic antiferromagnetic Kitaev-Heisenberg-T magnet

We study the Kitaev-Heisenberg-P model with antiferromagnetic Kitaev exchanges in the strong anisotropic (toric code) limit to understand the phases and the intervening phase transitions between the gapped Z2 quantum spin liquid and the spin-ordered (in the Heisenberg limit) as well as paramagnetic phases (in the pseudodipolar, Gamma, limit). We find that the paramagnetic phase obtained in the large Gamma limit has no topological entanglement entropy and is proximate to a gapless critical point of a system described by equal superposition of differently oriented stacked one-dimensional Z2 x Z2 symmetry protected topological phases. Using a combination of exact diagonalization calculations and field theoretic analysis we map out the phases and phase transitions to reveal the complete phase diagram as a function of the Heisenberg, the Kitaev, and the pseudodipolar interactions. Our work shows a rich plethora of unconventional phases and phase transitions and provides a comprehensive understanding of the physics of anisotropic Kitaev-Heisenberg-P systems along with our recent pape

Bridging the Divide Between Users and 3D Printers

A system model and associated parameters for the design of a web based 3D printer selection system is envisioned. Accessible through a webpage that will be mapped to a central 3D printer database, the system will provide users with access to the database of 3D printers available around the world. The purpose of the selection system is to match user 3D printing requirements to available 3D printers. It is anticipated that the selection system will help bridge the divide between users and 3D printers by helping to facilitate the 3D printer selection process

Towards Benchmarking Scene Background Initialization

Given a set of images of a scene taken at different times, the availability of an initial background model that describes the scene without foreground objects is the prerequisite for a wide range of applications, ranging from video surveillance to computational photography. Even though several methods have been proposed for scene background initialization, the lack of a common groundtruthed dataset and of a common set of metrics makes it difficult to compare their performance. To move first steps towards an easy and fair comparison of these methods, we assembled a dataset of sequences frequently adopted for background initialization, selected or created ground truths for quantitative evaluation through a selected suite of metrics, and compared results obtained by some existing methods, making all the material publicly available.Comment: 6 pages, SBI dataset, SBMI2015 Worksho

Chiral metals and entrapped insulators in a one-dimensional topological non-Hermitian system

In this work, we study many-body "steady states" that arise in the non-Hermitian generalization of the noninteracting Su-Schrieffer-Heeger model at a finite density of fermions. We find that the hitherto known phase diagrams for this system, derived from the single-particle gap closings, in fact correspond to distinct nonequilibrium phases, which either carry finite currents or are dynamical insulators where particles are entrapped. Each of these have distinct quasiparticle excitations and steady-state correlations and entanglement properties. Looking at finite-sized systems, we further modulate the boundary to uncover the topological features in such steady states, particularly the emergence of leaky boundary modes. Using a variety of analytical and numerical methods, we develop a theoretical understanding of the various phases and their transitions, and we uncover the rich interplay of nonequilibrium many-body physics, quantum entanglement, and topology in a simple looking yet rich model system

Higher-order topological insulators in amorphous solids

We identify the possibility of realizing higher order topological (HOT) phases in noncrystalline or amorphous materials. Starting from two- and three-dimensional crystalline HOT insulators, accommodating topological corner states, we gradually enhance structural randomness in the system. Within a parameter regime, as long as amorphousness is confined by an outer crystalline boundary, the system continues to host corner states, yielding amorphous HOT insulators. However, as structural disorder percolates to the edges, corner states start to dissolve into amorphous bulk, and ultimately the system becomes a trivial insulator when amorphousness plagues the entire system. These outcomes are further substantiated by computing the quadrupolar (octupolar) moment in two (three) dimensions. Therefore, HOT phases can be realized in amorphous solids, when wrapped by a thin (lithographically grown, for example) crystalline layer. Our findings suggest that crystalline topological phases can be realized even in the absence of local crystalline symmetry

Dichloro(diphenylarsino)ruthenium(III) & Its Reactions with Some Nitrogen Donors

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Fock space exploration by angle resolved transmission through quantum diffraction grating of cold atoms in an optical lattice

Light transmission or diffraction from different quantum phases of cold atoms in an optical lattice has recently come up as a useful tool to probe such ultra cold atomic systems. The periodic nature of the optical lattice potential closely resembles the structure of a diffraction grating in real space, but loaded with a strongly correlated quantum many body state which interacts with the incident electromagnetic wave, a feature that controls the nature of the light transmission or dispersion through such quantum medium. In this paper we show that as one varies the relative angle between the cavity mode and the optical lattice, the peak of the transmission spectrum through such cavity also changes reflecting the statistical distribution of the atoms in the illuminated sites. Consequently the angle resolved transmission spectrum of such quantum diffraction grating can provide a plethora of information about the Fock space structure of the many body quantum state of ultra cold atoms in such an optical cavity that can be explored in current state of the art experiments.Comment: 40 double spaced, single column pages, 40 .eps figures, accepted for publication in Physical Review

Three-Dimensional Genome Architecture Influences Partner Selection for Chromosomal Translocations in Human Disease

Chromosomal translocations are frequent features of cancer genomes that contribute to disease progression. These rearrangements result from formation and illegitimate repair of DNA double-strand breaks (DSBs), a process that requires spatial colocalization of chromosomal breakpoints. The “contact first” hypothesis suggests that translocation partners colocalize in the nuclei of normal cells, prior to rearrangement. It is unclear, however, the extent to which spatial interactions based on three-dimensional genome architecture contribute to chromosomal rearrangements in human disease. Here we intersect Hi-C maps of three-dimensional chromosome conformation with collections of 1,533 chromosomal translocations from cancer and germline genomes. We show that many translocation-prone pairs of regions genome-wide, including the cancer translocation partners BCR-ABL and MYC-IGH, display elevated Hi-C contact frequencies in normal human cells. Considering tissue specificity, we find that translocation breakpoints reported in human hematologic malignancies have higher Hi-C contact frequencies in lymphoid cells than those reported in sarcomas and epithelial tumors. However, translocations from multiple tissue types show significant correlation with Hi-C contact frequencies, suggesting that both tissue-specific and universal features of chromatin structure contribute to chromosomal alterations. Our results demonstrate that three-dimensional genome architecture shapes the landscape of rearrangements directly observed in human disease and establish Hi-C as a key method for dissecting these effects.National Human Genome Research Institute (U.S.) (grant T32 HG002295)United States. Dept. of Defense (National Defense Science and Engineering Graduate Fellowship Program)Fannie and John Hertz FoundationNational Institute of General Medical Sciences (U.S.) (grant 5T32 GM008313)National Institute of General Medical Sciences (U.S.) (Medical Scientist Training Program