Deep Ensemble of Weighted Viterbi Decoders for Tail-Biting Convolutional Codes

Tail-biting convolutional codes extend the classical zero-termination convolutional codes: Both encoding schemes force the equality of start and end states, but under the tail-biting each state is a valid termination. This paper proposes a machine-learning approach to improve the state-of-the-art decoding of tail-biting codes, focusing on the widely employed short length regime as in the LTE standard. This standard also includes a CRC code. First, we parameterize the circular Viterbi algorithm, a baseline decoder that exploits the circular nature of the underlying trellis. An ensemble combines multiple such weighted decoders, each decoder specializes in decoding words from a specific region of the channel words' distribution. A region corresponds to a subset of termination states; the ensemble covers the entire states space. A non-learnable gating satisfies two goals: it filters easily decoded words and mitigates the overhead of executing multiple weighted decoders. The CRC criterion is employed to choose only a subset of experts for decoding purpose. Our method achieves FER improvement of up to 0.75dB over the CVA in the waterfall region for multiple code lengths, adding negligible computational complexity compared to the circular Viterbi algorithm in high SNRs

Light-Heavy Symmetry: Geometric Mass Hierarchy for Three Families

The Universal Seesaw pattern coupled with a Light$\leftrightarrow$Heavy symmetry principle leads to the Diophantine equation $\displaystyle N = \sum_{i=1}^Nn_i$, where $n_i\geq 0$ and distinct. Its unique non-trivial solution $(3=0+1+2)$ gives rise to the geometric mass hierarchy $m_W$, $m_W\epsilon$, $m_W\epsilon^2$ for $N=3$ fermion families. This is realized in a model where the hybrid (yet Up$\leftrightarrow$Down symmetric) quark mass relations $m_d m_t \approx m_c^2\leftrightarrow m_u m_b \approx m_s^2$ play a crucial role in expressing the CKM mixings in terms of simple mass ratios, notably $\sin\theta_C \approx {m_c\over m_b}$.Comment: 12 pages, no figures, Revtex fil

Epidermolytic Ichthyosis Sine Epidermolysis

Epidermolytic ichthyosis (EI) is a rare disorder of cornification caused by mutations in KRT1 and KRT10, encoding two suprabasal epidermal keratins. Because of the variable clinical features and severity of the disease, histopathology is often required to correctly direct the molecular analysis. EI is characterized by hyperkeratosis and vacuolar degeneration of the upper epidermis, also known as epidermolytic hyperkeratosis, hence the name of the disease. In the current report, the authors describe members of 2 families presenting with clinical features consistent with EI. The patients were shown to carry classical mutations in KRT1 or KRT10, but did not display epidermolytic changes on histology. These observations underscore the need to remain aware of the limitations of pathological features when considering a diagnosis of EI

Linking Geometric Mass Hierarchy with Threefold Family Replication

A link is established between the observed (approximate) geometric mass hierarchy of quarks and leptons and the triangular structure of their tenable flavor representations. This singles out SU(3) as the horizontal flavor group, thereby linking the Fermi mass hierarchy with the threefold family replication. These linkages are exploited within a flavor-chiral SU(3) model, with fermions and Higgs bosons in the 3+6* representation. The model is Left-Right symmetric and utilizes the universal see-saw mechanism with a geometric mass suppression pattern. Given certain assumptions, the model produces successful mass-ratio (rather than square-mass-ratio) mixing angle relations and fixes the light quark mass ratio.Comment: Revtex, 11 twocolumn pages, No figure

Simplified Models for LHC New Physics Searches

This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ~50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.Comment: 40 pages, 2 figures. This document is the official summary of results from "Topologies for Early LHC Searches" workshop (SLAC, September 2010). Supplementary material can be found at http://lhcnewphysics.or

Binding of Superantigen Toxins into the CD28 Homodimer Interface Is Essential for Induction of Cytokine Genes That Mediate Lethal Shock

Bacterial superantigen toxins bind directly to the dimer interface of CD28, the principal co-stimulatory receptor, to induce a lethal cytokine storm, and peptides that prevent this binding can suppress superantigen lethality

Combining the contributions of behavioral economics and other social sciences in understanding taxation and tax reform

This paper extends previous work presented at the SABE/IAREP conference at St Mary’s University, Halifax (James, 2009). In the earlier paper it was shown that conventional economic theory is used to make the case for tax reform but does not always adequately incorporate all the relevant factors. However, an approach based on behavioral economics can make the difference between success and failure. In this paper the contributions of other social sciences are also included. Taxation is a particularly appropriate subject to explore the integration of the social sciences since they have all devoted considerable attention to it. It can be seen that different social sciences suggest a range of variables that might be taken into account in addition to those included in mainstream economics. Other social sciences also offer different methodological approaches and consider the possibility of different outcomes of the fiscal process. The paper concludes that it is not easy to integrate the social sciences in a single approach to the study of tax and tax policy. There may also be the risk of encouraging inappropriate integration - researchers operating outside their expertise can produce results that are not helpful. However, comparing the contribution of behavioral economics with those of the social sciences more generally, it can be seen that behavioral economics can offer a framework within which these areas can be examined. Indeed, it may be a useful channel to add the contributions of other social sciences to mainstream economic research