3,732 research outputs found

    Phase separation driven by surface diffusion: a Monte Carlo study

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    We propose a kinetic Ising model to study phase separation driven by surface diffusion. This model is referred to as "Model S", and consists of the usual Kawasaki spin-exchange kinetics ("Model B") in conjunction with a kinetic constraint. We use novel multi-spin coding techniques to develop fast algorithms for Monte Carlo simulations of Models B and S. We use these algorithms to study the late stages of pattern dynamics in these systems.Comment: 25 pages, 9 figure

    Susceptibilities and speed of sound from PNJL model

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    We present the Taylor expansion coefficients of the pressure in quark number chemical potential μ0=μB/3=μu=μd\mu_0=\mu_B / 3=\mu_u=\mu_d, for the strongly interacting matter as described by the PNJL model for two light degenerate flavours of quarks u and d. The expansion has been done upto eighth order in μ0\mu_0, and the results are consistent with recent estimates from Lattice. We have further obtained the specific heat CVC_V, squared speed of sound vs2v_s^2 and the conformal measure \cC.Comment: 13 pages, 8 figures, References added, some discussions on Fig. 4 modified, one table added, results unchanged, version to appear in Phys. Rev.

    Role of loop entropy in the force induced melting of DNA hairpin

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    Dynamics of a single stranded DNA, which can form a hairpin have been studied in the constant force ensemble. Using Langevin dynamics simulations, we obtained the force-temperature diagram, which differs from the theoretical prediction based on the lattice model. Probability analysis of the extreme bases of the stem revealed that at high temperature, the hairpin to coil transition is entropy dominated and the loop contributes significantly in its opening. However, at low temperature, the transition is force driven and the hairpin opens from the stem side. It is shown that the elastic energy plays a crucial role at high force. As a result, the phase diagram differs significantly with the theoretical prediction.Comment: 9 pages, 8 figures; J. Chem. Phys (2011

    Measuring Hacking Ability Using a Conceptual Expertise Task

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    Hackers pose a continuous and unrelenting threat to organizations. Industry and academic researchers alike can benefit from a greater understanding of how hackers engage in criminal behavior. A limiting factor of hacker research is the inability to verify that self-proclaimed hackers participating in research actually possess their purported knowledge and skills. This paper presents current work in developing and validating a conceptual-expertise based tool that can be used to discriminate between novice and expert hackers. The implications of this work are promising since behavioral information systems researchers operating in the information security space will directly benefit from the validation of this tool. Keywords: hacker ability, conceptual expertise, skill measuremen

    Effect of Fibonacci Modulation On Superconductivity

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    We have studied finite-sized single band models with short range pairing interactions between electrons in presence of diagonal Fibonacci modulation in one dimension. Two models, namely the attractive Hubbard model and the Penson-Kolb model, have been investigated at half-filling at zero temperature by solving the Bogoliubov-de Gennes equations in real space within a mean field approximation. The competition between ``disorder'' and the pairing interaction leads to a suppression of superconductivity (of usual pairs with zero centre-of-mass momenta) in the strong-coupling limit while an enhancement of the pairing correlation is observed in the weak-coupling regime for both the models. However, the dissimilarity of the pairing mechanisms in these two models brings about notable difference in the results. The extent to which the bond ordered wave and the η\eta-paired (of pairs with centre-of-mass momenta = π\pi) phases of the Penson-Kolb model are affected by the disorder has also been studied in the present calculation. Some finite size effects are also identified.Comment: 14 pages, 13 figure

    Can re-entrance be observed in force induced transitions?

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    A large conformational change in the reaction co-ordinate and the role of the solvent in the formation of base-pairing are combined to settle a long standing issue {\it i.e.} prediction of re-entrance in the force induced transition of DNA. A direct way to observe the re-entrance, i.e a strand goes to the closed state from the open state and again to the open state with temperature, appears difficult to be achieved in the laboratory. An experimental protocol (in direct way) in the constant force ensemble is being proposed for the first time that will enable the observation of the re-entrance behavior in the force-temperature plane. Our exact results for small oligonucleotide that forms a hairpin structure provide the evidence that re-entrance can be observed.Comment: 12 pages and 5 figures (RevTex4). Accepted in Europhys Lett. (2009

    Maximizing Profit Prediction: Forecasting Future Trends with LSTM Algorithm and compared with Loss function and Mean error code using Python

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    Profit prediction is a pivotal task in financial markets, empowering investors and traders to make informed decisions. In recent years, the advent of deep learning techniques has revolutionized the field of financial forecasting, offering the potential to extract intricate patterns and relationships from vast and complex datasets. This paper presents an innovative approach to profit prediction using Long Short Term Memory (LSTM) networks, a specialized type of Recurrent Neural Network{RNN). LSTM’s excel at capturing long term dependencies in sequential data, making them well-suited for modeling the dynamics of the financial markets. The core of the paper lies in the practical application of LSTM model architecture specially tailored for profit prediction. This includes defining the input layer, LSTM layers, fully connected layers and the output layer. The training and validation process is elucidated, covering data splitting, model training, validation techniques and hyper parameter tuning to enter ensure the model performance. The paper also explores the practical application of the LSTM-based profit prediction algorithm through a case study involving real-world financial data. Evaluation metrics such as Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) are employed to assess the algorithm's predictive accuracy and effectiveness. Additionally, the paper addresses risk assessment, a critical aspect of profit prediction in financial markets. It sheds light on the promising potential of LSTM-based profit prediction algorithms as a powerful tool for financial forecasting. It summarizes key findings, acknowledges limitations and challenges, and outlines future directions for improving the algorithm, including incorporating additional data sources and fine-tuning hyper parameters. The presented approach offers a significant advancement in the realm of profit prediction, enabling investors and traders to make more informed and data-driven decisions in an ever-evolving financial landscape. &nbsp

    Kinetics of Surface Enrichment: A Molecular Dynamics Study

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    We use molecular dynamics (MD) to study the kinetics of surface enrichment (SE) in a stable homogeneous mixture (AB), placed in contact with a surface which preferentially attracts A. The SE profiles show a characteristic double-exponential behavior with two length scales: \xi_-, which rapidly saturates to its equilibrium value, and \xi_+, which diverges as a power-law with time (\xi_+ \sim t^\theta). We find that hydrodynamic effects result in a crossover of the growth exponent from \theta \simeq 0.5 to \theta \simeq 1.0. There is also a corresponding crossover in the growth dynamics of the SE-layer thickness.Comment: 20 pages, 6 figures, Published in J. Chem. Phys. (Research Highlights

    The Stability of Strange Star Crusts and Strangelets

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    We construct strangelets, taking into account electrostatic effects, including Debye screening, and arbitrary surface tension sigma of the interface between vacuum and quark matter. We find that there is a critical surface tension sigma_crit below which large strangelets are unstable to fragmentation and below which quark star surfaces will fragment into a crystalline crust made of charged strangelets immersed in an electron gas. We derive a model-independent relationship between sigma_crit and two parameters that characterize any quark matter equation of state. For reasonable model equations of state, we find sigma_crit typically of order a few MeV/fm^2. If sigma <= sigma_crit, the size-distribution of strangelets in cosmic rays could feature a peak corresponding to the stable strangelets that we construct.Comment: 11 pages, LaTe

    Pulmonary Hypertension Registry of Kerala (PROKERALA) – Rationale, design and methods

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    AbstractBackgroundPulmonary hypertension (PH) is a disease associated with a high morbidity and mortality. There is paucity of data regarding PH from the developing countries including India.Idiopathic pulmonary arterial hypertension is the most important etiological factor in the western world, but PH secondary to rheumatic heart disease, chronic obstructive pulmonary disease and untreated congenital heart disease could well be the predominant causes in developing countries like India.The main objective of the PROKERALA study – Pulmonary hypertension Registry Of Kerala is to collect data regarding the etiology, practice patterns and one-year outcomes of patients diagnosed to have PH.MethodsThe study is a hospital-based registry in the state of Kerala supported and funded by the Cardiological Society of India, Kerala Chapter. A total of 77 hospitals have agreed to participate in the registry. PH was defined as systolic pulmonary artery pressure derived by echocardiography of more than 50mmHg (by tricuspid regurgitation jet) or mean PA pressure more than 25mmHg obtained at cardiac catheterization.A detailed questionnaire is administered which includes the demographic characteristics, risk factors, family history, ECG data, 6 minute walk test distance, chest X ray findings and echocardiographic data. Details of PH specific therapy and one-year follow-up data are collected.From a preliminary survey in the region, we estimated that we will be able to collect 2000 cases over a period of one year
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