血清白蛋白的功能及应用

血清白蛋白是脊椎动物血浆中含量最丰富的蛋白质.人血清白蛋白是由585个氨基酸组成的单链蛋白质,分子量为67 kDa.成熟的人血清白蛋白是一个心形分子,由3个结构相似的α-螺旋结构域组成.不同来源的血清白蛋白的氨基酸序列及其空间结构非常保守,它具有结合和运输内源性与外源性物质,维持血液胶体渗透压,清除自由基,抑制血小板聚集和抗凝血等生理功能.最近研究发现,蟾蜍血清白蛋白可能与其皮肤呼吸有关.人血清白蛋白目前已广泛应用于临床.

人类线粒体DNA世系的系统发育关系研究

本文以人类线粒体DNA为例,回顾了其系统发育关系的重建的研究历史,进而总结介绍了该分析方法在人类进化历史研究、线粒体DNA数据质量评估以及疾病相关线粒体DNA突变的甄别等方面的应用,以期对该方法在国内的推广应用有所裨益.

Stochastic resonance for modulated gain in a single-mode laser

Stochastic resonance (SR) induced by the signal modulation is investigated, by introducing the signal-modulated gain into a single-mode laser system. Using the linear approximation method, we detailedly calculate the signal-to-noise ratio (SNR) of a gain-noise model of the single-mode laser, taking the cross-correlation between the quantum noise and pump noise into account. We find that, SR appears in the dependence of the SNR on the intensities of the quantum and the pump noises when the correlation coefficient between both the noises is negative; moreover, when the cross-correlation between the two noises is strongly negative, SR exhibits a resonance and a suppression versus the gain coefficient, meanwhile, the single-peaked SR and multi-peaked SR occur in the behaviors of the SNR as functions of the loss coefficient and the deterministic steady-state intensity. (c) 2005 Elsevier B.V. All rights reserved.

A novel image restoration algorithm based on high-dimensional space geometry

A novel image restoration approach based on high-dimensional space geometry is proposed, which is quite different from the existing traditional image restoration techniques. It is based on the homeomorphisms and "Principle of Homology Continuity" (PHC), an image is mapped to a point in high-dimensional space. Begin with the original blurred image, we get two further blurred images, then the restored image can be obtained through the regressive curve derived from the three points which are mapped form the images. Experiments have proved the availability of this "blurred-blurred-restored" algorithm, and the comparison with the classical Wiener Filter approach is presented in final.

Stochastic resonance in single-mode semiconductor lasers

Owing to the considerable virtues of semiconductor lasers for applications, they have become the main optical source for fiber communication systems recently. The behavior of stochastic resonance (SR) in direct-modulated semiconductor laser systems is investigated in this article. Considering the carrier and photon noises and the cross-correlation between the two noises, the power spectrum of the photon density and the signal-to-noise ratio (SNR) of the modulated laser system were calculated using the linear approximation method. We found that the SR always appears in the dependence of the SNR upon the bias current density, and is strongly affected by the cross-correlation coefficient of the carrier and photon noises, the frequency of modulation signal and the photon lifetime in the laser cavity. Hence, it is promising to use the SR mechanism to enhance the SNR of direct-modulated semiconductor laser systems and improve the quality of optical communication. (c) 2006 Elsevier B.V. All rights reserved.

A novel image restoration algorithm based on high-dimensional space geometry

A novel image restoration approach based on high-dimensional space geometry is proposed, which is quite different from the existing traditional image restoration techniques. It is based on the homeomorphisms and "Principle of Homology Continuity" (PHC), an image is mapped to a point in high-dimensional space. Begin with the original blurred image, we get two further blurred images, then the restored image can be obtained through the regressive curve derived from the three points which are mapped form the images. Experiments have proved the availability of this "blurred-blurred-restored" algorithm, and the comparison with the classical Wiener Filter approach is presented in final.

Complex networks constructed from irrational number sequences

In this paper, we construct (d, r) networks from sequences of different irrational numbers. In detail, segment an irrational number sequence of length M into groups of d digits which represent the nodes while two consecutive groups overlap by r digits (r = 0,1,...,d-1), and the undirected edges indicate the adjacency between two consecutive groups. (3, r) and (4, r) networks are respectively constructed from 14 different irrational numbers and their topological properties are examined. By observation, we find that network topologies change with different values of d, r and even sequence length M instead of the types of irrational numbers, although they share some similar features with traditional random graphs. We make a further investigation to explain these interesting phenomena and propose the identical-degree random graph model. The results presented in this paper provide some insight into distributions of irrational number digits that may help better understanding of the nature of irrational numbers.

针对C语言的自动微分系统及其应用

采用切线性模式和代码转换策略,开发了C语言自动微分转换系统(DTC),用于牛顿法求解非线性方程中Jacobi矩阵—向量乘积计算。介绍系统计算模型、功能、特色,并讨论系统的设计与实现技术,包括编译技术、微分代码转换及输入/输出(I/O)相关分析。最后给出了几个具有说服力的测试与应用。

限界模型检测方法及其应用

形式化验证主要是通过精确的分析来证明或证伪硬件或软件系统中一些明确的声明或者性质。形式化验证方法在广义上可以分成两大类：模型检测和定理证明。模型检测由对模型的所有状态和迁移做详尽访问的自动检测机制组成。这种机制是通过对适当的抽象模型进行直接或间接的状态枚举技术来实现的，从而证明模型中存在或者不存在所谓的“瑕疵”状态。定理证明则是运用数学推理和逻辑推论来证明系统的正确性。本文所讨论的就是模型检测方法中的限界模型检测方法及其相关的改进和应用。近些年来，基于可满足性求解（SAT）的限界模型检测方法作为基于BDD的模型检测方法的一种有效的补充，已经有了一定的发展。A. Biere等人最先提出了对于线性时序逻辑公式（LTL）的限界模型检测方法，进而，W.Penczek又提出了对于全局计算树逻辑（ACTL）的限界模型检测方法。由于模型检测方法具有很高的复杂性，因此，其效率问题始终倍受关注。论文第一个方面的重要贡献就体现在提高限界模型检测效率方面的相关研究上。我们对Penczek提出的限界模型检测方法进行了两方面的改进，以提高其求解效率。第一方面的改进是通过改进所需路径条数计算函数，将时序操作符EX和其它时序操作符区分开来，以减少编码时所需的迁移关系和变量数目；第二方面的改进则是采用统一路径编码的方式来简化公式的编码。通过这两方面的改进，公式在最坏情况下的编码复杂度得到了有效的降低。同时，我们还在工具BMV中实现了改进后的方法。随着实时系统的应用日益广泛，在对全局计算树逻辑的限界模型检测方法做了改进，提高了其求解效率以后，我们又将目光转移到了对实时系统的限界模型检测上。如何将限界模型检测方法高效的运用到对实时系统的检测当中成为了本文第二个方面的重要贡献。基于SAT的限界模型检测方法在对实时系统的模型和描述性质的公式进行编码时，需要对时间变量和时钟约束进行布尔编码，由于时间的连续性和不确定性，使得在对它进行布尔编码时，往往会相当的复杂，不仅耗费大量的时间，而且还不利于SAT的求解，即使是使用改进后的限界模型检测方法，整个验证过程的效率还是很低。所以，在对实时系统进行限界模型检测方面，我们转而考虑采用基于可满足性模块理论（SMT）的方法来对实时系统的模型和描述性质的公式进行编码。由于SMT可以直接处理基于整数或者实数的线性算术表达式，因此，我们可以直接用整型或者实型变量来表示时间变量，用线性算术表达式来表示时钟约束。与基于SAT的限界模型检测方法相比，基于SMT的限界模型检测方法在处理实时系统方面，不仅简化了编码过程，而且大大提高了求解效率。在此基础上，我们运用基于SAT的对全局计算树逻辑的限界模型检测方法中的改进思想，对基于SMT的实时系统的限界模型检测方法也做了相应的改进，使其求解效率较之改进前有了较大的提升。最后，我们就基于SAT的限界模型检测方法和基于SMT的限界模型检测方法以及它们的改进方法进行了一系列的实验对比。从实验结果可以看出，改进后的方法比改进前的方法在时间效率和空间效率上都有明显的提升，同时就实时系统来说，采用了SMT和限界模型检测相结合的方法以后，效率也比没有采用这两者的方法要高很多。

on lin-bose problem

This paper study generalized Serre problem proposed by Lin and Bose in multidimensional system theory context [Multidimens. Systems and Signal Process. 10 (1999) 379; Linear Algebra Appl. 338 (2001) 125]. This problem is stated as follows. Let F ∈ Al×m be a full row rank matrix, and d be the greatest common divisor of all the l × l minors of F. Assume that the reduced minors of F generate the unit ideal, where A = K[x 1,...,xn] is the polynomial ring in n variables x 1,...,xn over any coefficient field K. Then there exist matrices G ∈ Al×l and F1 ∈ A l×m such that F = GF1 with det G = d and F 1 is a ZLP matrix. We provide an elementary proof to this problem, and treat non-full rank case.

认证字典及其在PKI中的应用研究

认证字典是一类重要的数据结构,它在众多研究领域都具有重要的理论和应用价值.文中介绍了认证字典的基本概念和原理,引入了时间约束,给出了一种新的认证字典分类方法.从认证字典在PKI中的应用出发,分析了其实现技术;并简单地分析和比较了基于不同认证字典实现的证书撤销方案.

服务自适应模型及其应用

提出了一个基于模糊理论的服务自适应模型。完整地形式化了服务自适应选择过程,使用模糊语言变量和隶属度方程定义了上下文状态和服务策略选择规则。基于当前上下文与服务实现策略标准上下文之间的模糊距离概念,提出了计算服务实现策略合适程度的合适度方程。结合名为“校园助理”的上下文敏感应用场景,阐述了该模型的有效性和具体应用。

Magnetic frustration induced quantum phase transitions in the S=1/2 vertically asymmetric diamond chain

This work was supported by the National Basic Research Program of China (973 Program) grant No. G2009CB929300 and the National Natural Science Foundation of China under Grant Nos. 60521001 and 60776061.

基于BDD的增量启发式搜索方法及其应用

增量启发式搜索是一种利用先前的搜索信息和启发信息提高本次搜索效率的方法，通常可用来解决动态环境下的重规划问题。在人工智能领域，一些实时系统常常需要根据外界环境的变化不断修正自身，这样就会产生一系列变化较小的相似问题，此时应用增量启发式搜索将会非常有效。另一方面，基于BDD的强大的搜索技术利用BDD有效操作性以及化简后唯一性的优点， 在一定程度上缓解了模型检测的状态爆炸问题，使得被检测状态的个数大大增加。 1、本文结合基于BDD的启发式搜索和基于BDD的增量搜索这两种方法给出了基于BDD的增量启发式搜索方法， 基于BDD的增量启发式搜索综合了基于BDD的搜索、增量搜索以及启发式搜索这三种方法的优点。它既用BDD作为数据结构以提高搜索的空间效率， 又结合了增量搜索的思想来提高重搜索的效率，同时，又引入了启发函数来进一步压缩搜索空间。 2、本文介绍了基于BDD的增量启发式搜索算法BDDRPA*并用大量的实验结果证明BDDRPA*的高效性。给定一个搜索问题， BDDRPA*算法先用基于BDD的启发式搜索方法搜出一条从初始节点到目标节点的最短路径；接着， 问题的状态格局发生改变，BDDRPA*再用基于BDD的增量搜索方法根据旧格局的迁移关系BDD_T构造出新格局的迁移关系BDD_{T'}， 然后再用启发式方法搜索路径，如此反复下去。 3、本文介绍了基于BDD的动态增量启发式搜索算法BDDD*并用大量的实验结果证明BDDD*的高效性。 BDDD*算法在机器人边走边扫描的过程中，不断根据机器人新获得的信息更新已知地图并重新规划路线。每次规划时，BDDD*都假设未知的领域没有任何障碍物， 也就是每个位置都是可通的，它按照这个假设去计算从当前位置到目标位置的最短路径。如果在行走的过程中扫描到了障碍物，它就把这条信息添加到它的地图中，然后重复 上面的过程，直到到达目标位置或者发现每条路径都被堵死为止。 BDDRPA*算法和BDDD*算法可以应用到机器人线路规划、智能交通及计算机网络的线路规划问题中。 另外，在机器学习和控制领域，也可以考虑使用BDDRPA*算法和BDDD*算法。