单点系泊船舶运动的仿真研究

应用计算机仿真方法,研究了潮流作用下系泊系统的运动响应。建立了三自由度运动微分方程。然后在仿真工具箱SIMULINK中建立了时域仿真模型。对系泊船只的运动进行了计算机仿真。给出了其运动响应的时间历程,讨论了系统刚性对系泊运动的影响,利用Liapunov理论分析了静止系泊位置的稳定性,指出了定性分析方法对于系泊系统设计的意义。     

量子力学和量子计算机

In this paper,the relationship between computation and physics and the application of the principle of Quantum mechanics to Quantum Computing and Quantum Computers was reviewed     

Uquantchem: A versatile and easy to use quantum chemistry computational software

In this paper we present the Uppsala Quantum Chemistry package (UQUANTCHEM), a new and versatile computational platform with capabilities ranging from simple Hartree–Fock calculations to state of the art First principles Extended Lagrangian Born–Oppenheimer Molecular Dynamics (XL-BOMD) and diffusion quantum Monte Carlo (DMC). The UQUANTCHEM package is distributed under the general public license and can be directly downloaded from the code web-site (http://www.anst.uu.se/pesou087/DOWNLOAD-UQUANTCHEM/DOWNLOAD-UQUANTCHEM/DOWNLOAD-SITE-UQUANTCHEM.html)  [1]. Together with a presentation of the different capabilities of the uquantchem code and a more technical discussion on how these capabilities have been implemented, a presentation of the user-friendly aspect of the package on the basis of the large number of default settings will also be presented. Furthermore, since the code has been parallelized within the framework of the message passing interface (MPI), the timing of some benchmark calculations are reported to illustrate how the code scales with the number of computational nodes for different levels of chemical theory.     

基于量子层析的量子态测量方案及其仿真

为解决量子态信息获取问题,基于量子层析理论,深入分析了单量子比特和多量子比特的层析理论,设计了利用量子态层析进行量子态测量的实验方案,并通过计算机仿真技术对单量子比特层析实验进行了模拟．在理论分析和仿真实验的基础上得到如下结论：通过适当选取测量次数,量子层析技术可以较为精确地重构量子态密度矩阵,获取量子态信息,同时可以兼顾实验效率．     

Unconditionally secure cryptosystems based on quantum cryptography

Most modern cryptographic studies design cryptosystems and algorithms using mathematical concepts. In designing and analyzing cryptosystems and protocols, mathematical concepts are critical in supporting the claim that the intended cryptosystem is secure. Most early cryptographic algorithms are based either on factorization or on discrete logarithm problem. Such systems generally adopt rather simple mathematics, and, therefore, need extensive secondary index computation. This study discusses quantum cryptosystems, protection of system security, and optimization of system efficiency. Quantum cryptography detects intrusion and wiretap. In quantum mechanics, a wiretap is neither external nor passive; rather it modifies its entity based on the internal component of the system. The status of the quantum system changes once a wiretap is detected. Hence, only the designer of the system can discover the quantum status of the system; an eavesdropper can neither determine the quantum state nor duplicate the system. The quantum cryptosystem can achieve unconditional security, and thus guarantees secure communication.     

An efficient and accurate quantum lattice-gas model for the many-body Schrödinger wave equation

Presented is quantum lattice-gas model for simulating the time-dependent evolution of a many-body quantum mechanical system of particles governed by the non-relativistic Schrödinger wave equation with an external scalar potential. A variety of computational demonstrations are given where the numerical predictions are compared with exact analytical solutions. In all cases, the model results accurately agree with the analytical predictions and we show that the model's error is second order in the temporal discretization and fourth order in the spatial discretization. The difficult problem of simulating a system of fermionic particles is also treated and a general computational formulation of this problem is given. For pedagogical purposes, the two-particle case is presented and the numerical dispersion of the simulated wave packets is compared with the analytical solutions.     

一种评估颅骨和颅面相似性的方法

针对评估颅面和颅骨轮廓相似性过程中的离散点对应、曲线拟合带来的误差以及人工干预问题, 提出一种基于重采样和Fourier变换的离散轮廓像素点的相似度量方法。首先使用Canny算子和滑动窗口方法进行边缘检测和边界跟踪, 得到待比较颅骨和颅面的边缘轮廓像素集合; 然后对轮廓统一重采样, 解决了两者离散点的对应问题; 最后直接对数据进行规格化和离散傅里叶变换, 利用傅里叶描述子进行相似性度量, 避免了曲线拟合导致的误差和手工介入问题。实验表明, 该算法提高了颅骨和颅面相似性度量的准确率, 复杂度较低, 可实现评价过程自动化, 为颅像重合身份认证奠定了基础。     

量子进程

由量子力学原理,酉变换和测量算子可以完成量子计算中的所有操作,但仅用酉变换和测量算子的序列并不能清楚地描述量子世界的并发与通信,因此本文提出了量子进程的概念,讨论量子进程通信的几种可能方式,并基于CCS建立了两个量子进程的一种互模拟关系,用以刻画传送量子进程的并发与通信。     

量子密钥分配协议

本文首先简要阐述了量子密码技术应用的量子力学基础,然后详细介绍了目前常用的量子密钥分配协议.     

悖论的生成机制和解释

从计算机科学中的具体悖论实例出发,使用对角线方法来说明一类悖论的生成机制,并指出自指代现象是悖论产生的深层次原因。传统的应对策略往往采用回避的方式,简单禁止自指代以避免悖论。从量子力学和范畴理论两个新视角出发,给出容纳悖论的新模型。结果表明,从新角度审视悖论不仅可以使悖论在某些新领域得到合理解释,而且能提供认识问题本质的新思维。     

分子计算理论方法及在化工计算中的应用

论述了量子力学中从头计算、半经验和密度泛函方法及分子力学的基础理论,概述了常用的MD、MC分子模拟方法,总结了多种应用软件的主要功能,并结合实例对HyperChem．7软件的功能进行了具体的说明。     

Kernel-based classification using quantum mechanics

This paper introduces a new nonparametric estimation approach inspired from quantum mechanics. Kernel density estimation associates a function to each data sample. In classical kernel estimation theory the probability density function is calculated by summing up all the kernels. The proposed approach assumes that each data sample is associated with a quantum physics particle that has a radial activation field around it. Schrödinger differential equation is used in quantum mechanics to define locations of particles given their observed energy level. In our approach, we consider the known location of each data sample and we model their corresponding probability density function using the analogy with the quantum potential function. The kernel scale is estimated from distributions of K-nearest neighbours statistics. In order to apply the proposed algorithm to pattern classification we use the local Hessian for detecting the modes in the quantum potential hypersurface. Each mode is assimilated with a nonparametric class which is defined by means of a region growing algorithm. We apply the proposed algorithm on artificial data and for the topography segmentation from radar images of terrain.     

基于脉动压力相关理论的火电机组循环水流量测量

介绍了在非洁净单相流体中，利用流体紊流产生的压力脉动随机信号作为相关测量信号源进行流量测量；避免大口径管道采用均速管测量非洁净流体时，取压孔被堵塞问题。与采用超声波、电容作为传感器的相关测量法相比，利用压力传感器测量压力脉动随机信号的相关测量法成本较低。     

现代模态逻辑在计算机科学中的应用研究

现代模态逻辑是在经典数理逻辑基础上发展起来的,主要包括狭义模态逻辑、道义逻辑、认知逻辑、信念逻辑、时态逻辑与动态逻辑。克里普克语义模型的建立,使得模态逻辑成为现代逻辑的重要分支之一,并成功应用到数学、经济学、社会科学、计算机科学和量子力学等众多领域。介绍了现代模态逻辑研究的主要内容,重点综述了现代模态逻辑在计算机科学的程序设计语言、知识表示与多代理系统以及模型检测、定理机器证明和非单调逻辑5个方面的应用,阐述了现代模态逻辑在计算机科学领域的研究目标、研究进展和发展趋势,最后指出现代模态逻辑研究中存在的问题,并预测其未来可能的研究与发展方向。     

Improved Gap Estimates for Simulating Quantum Circuits by Adiabatic Evolution

We use elementary variational arguments to prove, and improve on, gap estimates which arise in simulating quantum circuits by adiabatic evolution. Partially supported by the National Science Foundation under Grant DMS-0314228 and by the National Security Agency and Advanced Research and Development Activity under Army Research Office contract number DAAD19-02-1-0065.     

QCD研究与高性能科学计算--域分解、函数分解和并行程序设计技术

量子色动力学 ( Quantum ChromoDynamics,QCD) 研究是一个典型的高性能科学计算问题,它被美国著名的高性能计算与通信计划(HPCC)列为世界级重大挑战性课题之一.由于Fermion矩阵处理等对时空性能指标的超级要求,必须寻找新的计算机求解技术才能推动研究的进展.文章提出并分析了域分解和函数分解方法、方法导致的MIMD模式和并行程序设计技术.在Exemplar SPP1200／XA(简称SPP1200)系统上的测试表明,这些方法和技术对QCD的进一步研究具有重要的意义.