Quantum hydrodynamic simulation of discrete-dopant fluctuated physical quantities in nanoscale FinFET

Impact of the discrete dopants on device performance is crucial in determining the behavior of nanoscale semiconductor devices. Atomistic quantum mechanical device simulation for studying the effect of discrete dopants on device's physical quantities is urgent. This work explores the physics of discrete-dopant-induced characteristic fluctuations in 16-nm fin-typed field effect transistor (FinFET) devices. Discrete dopants are statistically positioned in the three-dimensional channel region to examine associated carrier's characteristic, concurrently capturing “dopant concentration variation” and “dopant position fluctuation”. An experimentally validated quantum hydrodynamic device simulation was conducted to investigate the potential profile and threshold voltage fluctuations of the 16-nm FinFET. Results of this study provide further insight into the problem of fluctuation and the mechanism of immunity against fluctuation in 16-nm devices.     

Light scattering from anisotropic, randomly rough, perfectly conducting surfaces

An approach is introduced for performing rigorous numerical simulations of electromagnetic wave scattering from randomly rough, perfectly conducting surfaces. It is based on a surface integral technique, and consists of determining the unknown electric surface current densities from which the electromagnetic field everywhere can be determined. The method is used to study the scattering of a p-polarized beam from an anisotropic Gaussian, randomly rough, perfectly conducting surface. It is demonstrated that the surface anisotropy gives rise to interesting and pronounced signatures in the angular intensity distribution of the scattered light. The origins of these features are discussed.     

Estimation of extreme percentiles in Birnbaum-Saunders distributions

The Birnbaum-Saunders distribution has recently received considerable attention in the statistical literature, including some applications in the environmental sciences. Several authors have generalized this distribution, but these generalizations are still inadequate for predicting extreme percentiles. In this paper, we consider a variation of the Birnbaum-Saunders distribution, which enables the prediction of extreme percentiles as well as the implementation of the EM algorithm for maximum likelihood estimation of the distribution parameters. This implementation has some advantages over the direct maximization of the likelihood function. Finally, we present results of a simulation study along with an application to a real environmental data set.     

芹菜素和山萘酚对细胞色素CYP1A2抑制机理研究

目的:我们先前的体外肝微粒体抑制活性实验,已证实芹菜素和山萘酚对细胞色素CYP 1A2有较强的抑制作用。然而,其抑制机理仍然未知。分子模拟方法能更好了解这2个天然产物对1A2的抑制机理。方法:采用分子对接、分子动力学模拟及结合自由能计算的方法,研究它们对1A2的抑制作用。结果:芹菜素和山萘酚对1A2的预测结合自由能分别是-18.01和-16.40 kcal/mol,这与实验抑制活性结果一致。在1A2结合口袋中,残基呈平面性排列,与平面芹菜素和山萘酚存在紧密的范德华和疏水相互作用,因而小分子有较强的抑制作用。此外,活性位点残基也与小分子发生氢键和盐桥等相互作用,使小分子在结合口袋中的位置得到固定。     

On the Design of Link-State Routing Protocol for Connection-Oriented Networks

Link-state routing protocols are being increasingly used in modern communications networks. A salient feature of this class of routing protocols is that network connectivity and state information of all links are available to nodes for making routing decision. Two main components of a link-state routing protocol are an update mechanism and a routing algorithm. These components must be properly designed for efficient routing. Various alternatives are possible for each of these components leading to different scenarios for routing protocol. In this paper, we quantitatively examine the impact of these alternatives on network performance using call-by-call simulations. Our design objective is to reduce call blocking ratio without significantly increasing routing overhead. We also present a new signaling scheme that can be used in conjunction with link-state protocols. We show that, if properly designed, this scheme can enhance the network performance.     

High-Energy Physics on the Grid: the ATLAS and CMS Experience

In this paper we present the experience of the ATLAS and CMS High-Energy Physics (HEP) experiments at the Large Hadron Collider (LHC) with the LCG/EGEE Grid infrastructure. The activity developed around the following two main lines: large-scale physics and detector simulations and end-user analysis. The LCG/EGEE Grid infrastructure offers a large amount of computing and storage resources and is growing very rapidly. It provides the natural environment for large-scale physics and detector simulations. Also, the analysis of these detector simulation data (and in the near future of the reconstructed data from physics collisions) requires efficient end-users access to Grid resources. In this paper, the main findings and lessons learned in terms of performance, robustness and scalability of the whole system are discussed in detail.     

Time Changes, Laplace Transforms and Path-Dependent Options

Path-dependent options have become increasingly popular over the last few years, in particular in FX markets, because of the greater precision with which they allow investors to choose or avoid exposure to well-defined sources of risk. The goal of the paper is to exhibit the power of stochastic time changes and Laplace transform techniques in the evaluation and hedging of path-dependent options in the Black–Scholes–Merton setting. We illustrate these properties in the specific case of Asian options and continuously (de-) activating double-barrier options and show that in both cases, the pricing and, just as important, the hedging results are more accurate than the ones obtained through Monte Carlo simulations.     

A Simulation Study on the Behavior of Magnetorheological Fluid on Herringbone-Grooved Hybrid Slot-Entry Bearing

Abstract

In recent years, extensive use of smart lubricants has been made in order to control the tribological performance of fluid film bearings. The grooved surfaces of the journal bearing greatly influence the performance of bearings. In the present work, various geometric shapes of herringbone grooves (rectangular, triangular, and parabolic) with groove angles (30° and 60°) have been considered to numerically simulate the performance of slot-entry bearings. The work reported in this article deals with the numerical simulation of magnetorheological (MR) fluid–lubricated slot-entry herringbone-grooved hybrid journal bearings. Dave equation, a constitutive relation of the Bingham model, was employed to simulate the flow behavior of MR fluid. Using the finite element method (FEM), the governing Reynolds equation for a hybrid slot-entry bearing model was solved. The result shows that the use of a herringbone-grooved surface and application of MR fluid in a slot-entry bearing offers better stability and higher fluid film stiffness and minimizes frictional torque.     

闽江下游天然河床的未来演进趋势

在探明闽江下游天然河道河沙储量的基础上,分别从水动力作用和人为挖沙两个方面预测闽江下游河床演变的趋势,提出了基于水动力作用引发河床演变的“三类分区”假说和基于人为挖沙引发河床演变的“四区分类”假说,并分别给出了水动力和人为挖沙对河道关键断面水位变化规律的影响。研究结果表明：人为挖沙对闽江下游河道演变的影响大于水动力作用对天然河道的影响。闽江下游河床演变研究工作对其堤防安全、闽江口湿地保护、城市饮用水安全、跨江桥梁及沿江公路安全、航运和沿江城市污染物排放控制均具有重要意义。     

淮河干流正阳关至峡山口段 河道整治研究

通过分析淮河干流形态、水沙时空分布、冲淤变化等基本特性,开展了河工模型试验研究和二维水动力数值计算,采用2003、2005、2007年实测洪水资料对模型进行率定与验证,模拟值与实测资料吻合较好,为河道整治提供了研究思路。利用模型对河道整治方案进行了效果分析,对行洪区调度方案进行了优化。