A Discrete Logarithm-based Approach to Compute Low-Weight Multiples of Binary Polynomials

Being able to compute efficiently a low-weight multiple of a given binary polynomial is often a key ingredient of correlation attacks to LFSR-based stream ciphers. The best known general purpose algorithm is based on the generalized birthday problem. We describe an alternative approach which is based on discrete logarithms and has much lower memory complexity requirements with a comparable time complexity.Comment: 12 page

Understanding how high-tech entrepreneurs successfully pivot as part of the entrepreneurial journey

Purpose: In their entrepreneurial journey, high-tech entrepreneurs continuously face a need to devise a competitive value proposition for the startup company and leverage emerging technology to strengthen the proposition. Entrepreneurial pivoting addresses this challenge by allowing startups to validate and refine both their strategy and business model. Therefore, the research study has investigated two theories: the Lean Startup Approach and Technology Entrepreneurship. Consequently, the study has provided an empirical investigation of the pivoting concept examined in the context of the Lean Startup approach (LSA) and Technology Entrepreneurship to improve the understanding of the entrepreneurial journey for high-tech entrepreneurs. The research also focused on understanding how the life cycle stage of an emerging technology impacts the high-tech entrepreneurs’ entrepreneurial journey. The Lean Startup Approach, the technology S-curve, and the technology readiness level (TRL) framework were investigated to address the above question. The study has provided an empirical investigation of the pivoting concept, which has been explained in the context of the lean startup approach (LSA), the technology S-curve and the technology readiness level to improve the understanding of the entrepreneurial journey for high-tech entrepreneurs leading tech startups. Apart from investigating how high-tech entrepreneurs develop competitive value propositions and how emerging technologies impact their entrepreneurial journey, the research study also investigated leadership styles and their influence on tech entrepreneurs. For this, the study has empirically investigated pivoting from the Lean Startup Approach and six different leadership styles. Due to studying pivoting from the Lean Startup Approach and investigating technology entrepreneurship, technology S-curve and technology readiness levels, this research study is titled ‘Understanding how high-tech entrepreneurs successfully pivot their startups as part of the entrepreneurial journey’. Methodological Approach: A qualitative research method was adopted by interviewing hightech entrepreneurs across the United Kingdom to validate the theories associated with the LSA and identify new insights on entrepreneurial pivoting. The interviews are divided into two stages. Firstly, thirty primary interviews were conducted to understand pivoting and the factors that trigger pivoting; the influence of the phases of technology entrepreneurship on pivoting; and the impact of stages of technology maturity in the technology S-curve on pivoting. Secondly, longitudinal interviews were conducted in three phases with nine high-tech entrepreneurs who were also involved in the thirty primary interviews. The purpose of the longitudinal interviews was to collect further data on the above-mentioned topics and understand in more detail and build up a richer picture on how high-tech startups successfully pivot as part of the entrepreneurial journey. Findings: The research study has validated the existing types of pivots and identified two new pivots (giving 16 in total). The study has validated 11 factors that trigger a tech startup to change direction and identified three new factors (giving 14 in total). The research study also determined that there can be a domino effect in pivoting, and the value proposition can be created and sustained through pivoting. The study has established the influence of the phases of technology entrepreneurship on pivoting and the impact of the stages of technology maturity in the technology S-curve on pivoting. Originality: The study provides empirical evidence on pivots and the factors associated with pivots. Moreover, the study significantly helps to improve the understanding of the influence of the phases of technology entrepreneurship on pivoting. The study has developed a new conceptual framework for TE. Furthermore, the study helped in understanding the impact of the stage of technology in the technology S-curve and technology readiness level on pivoting. The study also discusses the challenges faced by tech startups while pursuing pivots; the domino effect in pivoting; and has found evidence that pivoting leads to achieving the desired results

A model for multifragmentation in heavy-ion reactions

From an experimental point of view, clear signatures of multifragmentation have been detected by different experiments. On the other hand, from a theoretical point of view, many different models, built on the basis of totally different and often even contrasting assumptions, have been provided to explain them. In this contribution we show the capabilities and the shortcomings of one of this models, a QMD code developed by us and coupled to the nuclear de-excitation module taken from the multipurpose transport and interaction code FLUKA, in reproducing the multifragmentation observations recently reported by the INDRA collaboration for the reaction Nb + Mg at a 30 MeV/A projectile bombarding energy. As far as fragment production is concerned, we also briefly discuss the isoscaling technique by considering reactions characterized by a different isospin asymmetry, and we explain how the QMD + FLUKA model can be applied to obtain information on the slope of isotopic yield ratios, which is crucially related to the symmetry energy of asymmetric nuclear matter.Comment: 8 pages, 2 figures, Proc. 12th International Conference on Nuclear Reaction Mechanisms, Varenna, Italy, June 15 - 19 200

Decidability of the interval temporal logic ABBar over the natural numbers

In this paper, we focus our attention on the interval temporal logic of the Allen's relations "meets", "begins", and "begun by" (ABBar for short), interpreted over natural numbers. We first introduce the logic and we show that it is expressive enough to model distinctive interval properties,such as accomplishment conditions, to capture basic modalities of point-based temporal logic, such as the until operator, and to encode relevant metric constraints. Then, we prove that the satisfiability problem for ABBar over natural numbers is decidable by providing a small model theorem based on an original contraction method. Finally, we prove the EXPSPACE-completeness of the proble

High energy extension of the FLUKA atmospheric neutrino flux

The atmospheric neutrino flux calculated with FLUKA was originally limited to 100-200 GeV for statistical reasons. In order to make it available for the analysis of high energy events, like upward through-going muons detected by neutrino telescopes, we have extended the calculation so to provide a reliable neutrino yield per primary nucleon up to about 10**6 GeV/nucleon, as far as the interaction model is concerned. We point out that the primary flux model above 100 GeV/nucleon still contributes with an important systematic error to the neutrino flux.Comment: Extended version (10 pages) of the contribution to ICRC 2003, with the addition of flux table

The interaction-strength interpolation method for main-group chemistry: benchmarking, limitations, and perspectives

We have tested the original interaction-strength-interpolation (ISI) exchange-correlation functional for main group chemistry. The ISI functional is based on an interpolation between the weak and strong coupling limits and includes exact-exchange as well as the G\"orling-Levy second-order energy. We have analyzed in detail the basis-set dependence of the ISI functional, its dependence on the ground-state orbitals, and the influence of the size-consistency problem. We show and explain some of the expected limitations of the ISI functional (i.e. for atomization energies), but also unexpected results, such as the good performance for the interaction energy of dispersion-bonded complexes when the ISI correlation is used as a correction to Hartree-Fock.Comment: 20 pages, 20 figure

Possible, alternative explanations of the T2K observation of the nu_e appearance from an initial nu_mu

An alternative explanation to the emergence of sin^2(2 theta_13) > 0 is discussed. It is pointed out that the recorded T2K events might have been due to some other new physics in the neutrino sector, related to the LSND/MiniBooNE sterile neutrino anomalies, for which there is nowadays a growing evidence. The presently running ICARUS detector with the CNGS beam will be able to distinguish between these two possible sources of the effectComment: 5 pages, 1 figur