Numerical study of a non-equilibrium interface model

We have carried out extensive computer simulations of one-dimensional models related to the low noise (solid-on-solid) non-equilibrium interface of a two dimensional anchored Toom model with unbiased and biased noise. For the unbiased case the computed fluctuations of the interface in this limit provide new numerical evidence for the logarithmic correction to the subnormal L^(1/2) variance which was predicted by the dynamic renormalization group calculations on the modified Edwards-Wilkinson equation. In the biased case the simulations are in close quantitative agreement with the predictions of the Collective Variable Approximation (CVA), which gives the same L^(2/3) behavior of the variance as the KPZ equation.Comment: 15 pages revtex, 4 Postscript Figure

Statistical Properties of Contact Maps

A contact map is a simple representation of the structure of proteins and other chain-like macromolecules. This representation is quite amenable to numerical studies of folding. We show that the number of contact maps corresponding to the possible configurations of a polypeptide chain of N amino acids, represented by (N-1)-step self avoiding walks on a lattice, grows exponentially with N for all dimensions D>1. We carry out exact enumerations in D=2 on the square and triangular lattices for walks of up to 20 steps and investigate various statistical properties of contact maps corresponding to such walks. We also study the exact statistics of contact maps generated by walks on a ladder.Comment: Latex file, 15 pages, 12 eps figures. To appear on Phys. Rev.

Open X-Embodiment:Robotic learning datasets and RT-X models

Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for many applications. Can such a consolidation happen in robotics? Conventionally, robotic learning methods train a separate model for every application, every robot, and even every environment. Can we instead train "generalist" X-robot policy that can be adapted efficiently to new robots, tasks, and environments? In this paper, we provide datasets in standardized data formats and models to make it possible to explore this possibility in the context of robotic manipulation, alongside experimental results that provide an example of effective X-robot policies. We assemble a dataset from 22 different robots collected through a collaboration between 21 institutions, demonstrating 527 skills (160266 tasks). We show that a high-capacity model trained on this data, which we call RT-X, exhibits positive transfer and improves the capabilities of multiple robots by leveraging experience from other platforms. The project website is robotics-transformer-x.github.io

Enhancing Data Base Security in Cloud Computing

Information security has reliably been a significant issue in data innovation. In the distributed computing condition, it turns out to be especially genuine in light of the fact that the distributed is suitable in better places even in all the globe. Distributed and security insurance are the two fundamental components of client's worries about the cloud innovation. Despite the fact that numerous procedures on the themes in distributed computing have been researched in the two ventures, information security and security assurance are getting progressively significant for the future improvement of distributed computing innovation in government, industry, and business. Information security and protection assurance issues are significant to both equipment and programming in the cloud design. This examination is to survey diverse security methods and difficulties from both programming and equipment angles for ensuring information in the cloud and targets upgrading the information security and protection assurance for the dependable cloud condition. In this paper, we make a relative research examination of the current research work with respect to the information security and security assurance procedures utilized in the distributed computing.</jats:p

Implementation of Multiple Pagesize Support in HP-UX

To reduce performance degradation from Translation Lookaside Buffer (TLB) misses without significant increase in TLB size, most modern processors implement TLBs that support multiple pagesizes. For example, Hewlett-Packard&apos;s PA-8000 processor allows 8 hardware pagesizes, in multiples of four, ranging from 4 Kbytes to 64 Mbytes. In implementing multiple pagesize support in HP-UX, wechose to create large pages at page-fault service time. Wehave a buddy system allocator that provides interfaces for allocating and freeing multiple pagesizes. We maintain the Virtual Memory (VM) data structures such as the pagetable entry, virtual page frame descriptor, and physical page frame descriptor based on the smallest pagesize, and represent a large pagesize as a collection of these base pagesize structures. In our implementation, VM operations on a large pagesize such as 16KB are carried out by looping over the 4KB-based constituent VM data structures. Our system offers significant application perfor..