Nonlinear structures and thermodynamic instabilities in a one-dimensional lattice system

The equilibrium states of the discrete Peyrard-Bishop Hamiltonian with one end fixed are computed exactly from the two-dimensional nonlinear Morse map. These exact nonlinear structures are interpreted as domain walls (DW), interpolating between bound and unbound segments of the chain. The free energy of the DWs is calculated to leading order beyond the Gaussian approximation. Thermodynamic instabilities (e.g. DNA unzipping and/or thermal denaturation) can be understood in terms of DW formation.Comment: 4 pages, 5 figures, to appear in Phys. Rev. Let

Strategizing In the Context of Transitional Economy: The Interplay between Firm Level and Institutional Logics

Using the dual concepts of ‘dominant logic’ and institutional logics, this paper examines how senior managers in the context of transition economy navigate between the competing logics of state- dependency and market-dependency when seeking to explain their firms’ business strategies. By comparing accounts in matched-paired case studies drawn from state versus private sectors, the study reveals how top teams develop shared dominant logics which are patterned in a manner which reveals that the degree of state-dependency was the critical variable and that market was a subsidiary variable. Further, the study found that it was the top teams in the state-owned firms which articulated the more confident, proactive expansionary plans, while the top managers in the private sector firms presented more cautious and incremental business strategies. Contextual conditions are described which help account for these contrasting patterns

The opportunity cost and endowment effects of resources and capabilities on stages of entrepreneurship

In this paper, the start-up process is split conceptually into four entrepreneurial stages considering entrepreneurship, intending to start a new business in the next three years, nascent entrepreneurship and newly established business. We investigate the determinants of the start-up process using a multinomial logit model which allows the effects of resources and capabilities to vary across the different entrepreneurial stages. We employ a pooled Global Entrepreneurship Monitor database for the years 2006 to 2009, containing 8,269 usable observations of the East Midlands region in the United Kingdom, controlling for the local environmental effects. Our results show that the combinative role of human capital, experience and local context varies along the different stages of the entrepreneurial process. In the early stages the (negative) opportunity cost effect of resources dominates tends to reverse in advanced stages, where the (positive) endowment effect becomes stronger

Resource endowment and opportunity cost effects along the stages of entrepreneurship

In this paper, the start-up process is split conceptually into four stages: considering entrepreneurship, intending to start a new business in the next three years, nascent entrepreneurship, and owning-managing a newly established business. We investigate the determinants of all of these jointly, using a multinomial logit model; it allows for the effects of resources and capabilities to vary across these stages. We employ the Global Entrepreneurship Monitor database for the years 2006 to 2009, containing 8,269 usable observations from respondents drawn from the Lower Layer Super Output Areas in the East Midlands (UK) so that individual observations are linked to space. Our results show that the role of education, experience, and availability of 'entrepreneurial capital' in the local neighbourhood varies along the different stages of the entrepreneurial process. In the early stages the negative (opportunity cost) effect of resources endowment dominates, yet it tends to reverse in the advanced stages, where the positive effect of resources becomes stronger

Reversal of Fortune: Opportunity Cost and Endowment Effects Along Stages of Entrepreneurship

In this paper, the start-up process is split conceptually into four entrepreneurial stages considering entrepreneurship, intending to start a new business in the next three years, nascent entrepreneurship and newly established business. We investigate the determinants of all of these stages jointly, using a multinomial logit model which allows the effects of resources and capabilities to vary across these different entrepreneurial stages. We employ a pooled Global Entrepreneurship Monitor database for the years 2006 to 2009, containing 8,269 usable observations of the East Midlands region in the United Kingdom, controlling for the local environmental effects. Our results show that the role of human capital, experience and local context varies along the different stages of the entrepreneurial process. In the early stages the negative (opportunity cost) effect of resources dominates, yet it tends to reverse in advanced stages, where the positive (endowment) effect becomes stronger

Leveraging Expert Models for Training Deep Neural Networks in Scarce Data Domains: Application to Offline Handwritten Signature Verification

This paper introduces a novel approach to leverage the knowledge of existing expert models for training new Convolutional Neural Networks, on domains where task-specific data are limited or unavailable. The presented scheme is applied in offline handwritten signature verification (OffSV) which, akin to other biometric applications, suffers from inherent data limitations due to regulatory restrictions. The proposed Student-Teacher (S-T) configuration utilizes feature-based knowledge distillation (FKD), combining graph-based similarity for local activations with global similarity measures to supervise student's training, using only handwritten text data. Remarkably, the models trained using this technique exhibit comparable, if not superior, performance to the teacher model across three popular signature datasets. More importantly, these results are attained without employing any signatures during the feature extraction training process. This study demonstrates the efficacy of leveraging existing expert models to overcome data scarcity challenges in OffSV and potentially other related domains

Lyapunov exponents as a dynamical indicator of a phase transition

We study analytically the behavior of the largest Lyapunov exponent $\lambda_1$ for a one-dimensional chain of coupled nonlinear oscillators, by combining the transfer integral method and a Riemannian geometry approach. We apply the results to a simple model, proposed for the DNA denaturation, which emphasizes a first order-like or second order phase transition depending on the ratio of two length scales: this is an excellent model to characterize $\lambda_1$ as a dynamical indicator close to a phase transition.Comment: 8 Pages, 3 Figure

Bubbles, clusters and denaturation in genomic DNA: modeling, parametrization, efficient computation

The paper uses mesoscopic, non-linear lattice dynamics based (Peyrard-Bishop-Dauxois, PBD) modeling to describe thermal properties of DNA below and near the denaturation temperature. Computationally efficient notation is introduced for the relevant statistical mechanics. Computed melting profiles of long and short heterogeneous sequences are presented, using a recently introduced reparametrization of the PBD model, and critically discussed. The statistics of extended open bubbles and bound clusters is formulated and results are presented for selected examples.Comment: to appear in a special issue of the Journal of Nonlinear Mathematical Physics (ed. G. Gaeta