(2+1)维非线性演化方程的形式新解

主要从两个方面讨论(1)将非线性演化方程的形式级数解进行对称延拓;(2)利用"秩"的概念,对非线性演化方程进行分类.即如果方程各项中"秩"的取值全为奇数或偶数,则可借助椭圆方程的方法解之;若方程各项中"秩"的取值奇偶性不一致,则给出一形式幂级数解.并以两个(2+1)维非线性演化方程为例,说明改进的方法能较好地求得非线性演化方程的更多形式新解.     

中国高煤阶地区的煤层气勘探理论与实践

通过对中美两国煤层气生成地质条件的对比,认为中国煤层气形成和富集有着不同于美国的特征。我国华南和华北地区广泛分布高煤阶煤层,煤层气资源丰富。在成煤后期多个方向和期次的构造运动改造下,部分高煤阶煤层的渗透性有可能得到改善。通过地质研究,可以在高煤阶地区找到高产富集区。在这种思路指导下,在我国沁水含煤盆地南部无烟煤地区发现了大型高煤阶煤层气田——沁水煤层气田。这不仅丰富了煤层气富集成藏理论,对于拓展煤层气勘探领域也具有重要意义。      

Conditions for Parametric and Geometric Coincidence of Two Rational Curves

Necessary and sufficient conditions for the relationship of weights and control points of two parametrically and geometrically coincident rational Bézier or NURBS curves are discussed in detail. The method is based on the reduction of matrices and transformation between rational Bézier curves and NURBS curves.     

Hamilton系统等能曲面之奇异同调群的秩估计

为了加深对等能曲面的拓扑结构的了解,利用正合同调序列及Morse不等式的方法估计了等能曲面一般维数奇异同调群的秩的上界.分别对等能曲面的0维、1维、2维奇异同调群的秩进行了估计,得出了估计不等式,依据0维、1维、2维的估计不等式,归纳出一般维数奇异同调群的秩的上界估计不等式,证明此归纳不等式成立,并将其运用到刚体运动的力学例子中,与前人研究结果对照,验证其正确性.     

利用El Gamal密码体制解决安全多方多数据排序问题

基于E1Gamal同态密码体制给出了一个解决百万富翁问题的扩展问题的协议——安全多方多数据排序协议。并使用安全多方计算的对安全性的定义，在半诚实模型下，对协议的正确性和安全性进行了理论证明。该协议为保密电子投标和拍卖、保密在线交易等新型电子交易奠定了基础。     

2014年中国高性能计算机发展现状分析与展望

本文根据2014 年11 月发布的中国高性能计算机TOP100 排行榜的数据,对国内高性能计算机的发展现状从总体性能、制造商、行业领域等方面进行了深入分析。我们发现, 由于天河二号超级计算机的发布,中国TOP100 的平均Linpack 性能已经从两年前的落后一年变为比国际TOP500 平均Linpack 性能高的局面,且TOP100 的入门性能门槛也第一次超过TOP500。在此基础上,根据十三届排行榜积累的性能数据和能够得到的其他公开历史数据,对未来几年中国大陆高性能计算机的发展趋势进行了分析预测。根据新的数据和实际情况,经修正后我们认为,累计Linpack 性能将在2015 年到2016 年间达到100Petaflops, 比我们原来预期的晚;峰值100Petaflops 的机器将在2015 年到2016 年间出现;峰值Exaflops 的机器将在2019 年到2020 年间出现,比我们原来预期的晚2 年。单台机器峰值超过累计Linpack 性能的情况出现在2018 到2019 年间。     

多维度等级评分模型优化技术

研究了多维度等级评分模型的训练学习优化技术.为了解决不同用户之间的评分标注所存在的不一致性,提出两种简单、有效的模型训练优化技术,包括基于容忍度的样本选择方法和基于排序损失的样本选择方法.另外,为了充分利用不同特征的用户评分标注之间的相关性,提出了一个面向属性的协同过滤技术以改善多维度等级评分模型.在两个公开的英语和汉语真实餐馆评论数据集上进行实验验证,实验结果表明,所提出的方法有效地改善了等级评分的性能.     

Approximate controllability of linear retarded systems in Hilbert spaces

The object of this paper is to construct some results on the control problems for retarded functional differential equations of parabolic type with unbounded principal operators in Hilbert spaces. In order to establish relations between controllability of the given equation and observability of the adjoint system, we investigate the equivalent relation for the completeness of generalised eigenspaces of the infinitesimal generators. Finally, when the control space is a finite-dimensional space, a necessary and sufficient condition for the approximate controllability of retarded equations is given by the so-called rank condition.     

Nonparametric testing against restricted alternatives under progessive censoring

Nonparametric testing procedures under progressive censoring schemes are often adopted in clinical trials and life testing experimentations. In a variety of situations, a null hypothesis (of the homogeneity of distributions) may be tested against a restricted viz., orthant or ordered alternative. Though such tests in a general setup have been considered in a complete sample or a single point censored (or truncated) experimental scheme, there has not been much progress with these tests in a progressively censored setup. Genuinely distribution free tests based on simple linear rank statistics and the classical union intersection principle are considered. The theory of such time sequential tests rests heavily on some basic invariance principles, and these are studied as well. The case of proportional hazard models is also treated briefly. The main emphasis is laid on the development of the relevant asymptotic theory, and in this context, some (sub) martingale characterizations of progressively censored rank statistics have been incorporated.     

DRYING OF WOOD BIOMASS AT HIGH PRESSURE STEAM ATMOSPHERE; EXPERIMENTAL RESEARCH AND APPLICATION

ABSTRACT

Imatran Voima Oy together with Technical Research Centre of Finland has carried out experimental research on fuel drying at high pressure steam atmosphere. The pilot dryer is a pressurized flash dryer. Since its commissioning in 1991, the dryer has been used for drying experiments of peat and wood biomass for about 1000 h. The dryer operates at 23 bar pressure steam atmosphere with capacity of abt. 1000 kg/h of wet feedstock.

The developed high pressure steam dryer is planned to be used in a power plant process suitable for wet fuels as peat, biomass, and brown coal. The process is based on the connection of a pressurized fuel dryer, a pressurized gasifier, and a gas turbine. The integration of the high pressure steam dryer to the process increases the power generating efficiency of the process essentially.