基于DNA链置换技术的10线-4线优先编码器设计与实现

近年来,DNA链置换技术成为十分热门的技术领域,在众多的领域有广泛的应用,如DNA链置换技术被用于构造DNA纳米结构和逻辑计算系统等.DNA链置换技术与荧光标记技术的结合,使得DNA逻辑电路系统的思想成为现实.本文提出了一种基于DNA链置换技术的10线-4线邮箱编码器,其中使用了Seesaw模块作为基本单元.本文使用VisualDSD软件对所设计的电路系统进行了仿真模拟,结果显示:模型结构稳定,能够稳定高效实现10线-4线优先编码器的功能.     

粒计算下的粗糙集模型比较*

提出了几种组合粒下的粗糙集模型,并将其与单一粒下的粗糙集进行了比较,同时与粒逻辑运算下的粗糙集模型进行了比对,创造性地得到了组合粒、单一粒以及粒逻辑运算下的粗糙集模型之间的关系。结果表明,组合粒与粒逻辑运算组成了一个链结构,这为研究基于信息粒的知识获取以及动态粒的推理奠定了基础。     

DNA计算机算术运算的自装配模型(Ⅲ)—减法

DNA计算是基于DNA分子生化反应,能够在DNA计算机上实现的算法。它具有高度并行性、容量大、速度快等特点。同传统电子计算机一样,它也是以加、减、乘、除等简单算术运算和异或等逻辑运算为基本运算单元。在DNA自装配加法的基础上,设计了一般的DNA自装配并行减法模型,算法的时间复杂度为O(1),空间复杂度为O(n),并通过实例验证了算法的有效性。算法的主要优点在于编码简单、效率高,且具有通用性。     

DNA逻辑计算模型的研究现状与展望

DNA计算因其优异的计算能力已经成为当前研究热点,DNA逻辑计算模型是DNA计算体系与运算实现的重要依托。按应用技术将现有DNA逻辑计算模型进行分类：基于链置换的DNA逻辑计算模型、基于核酶的DNA逻辑计算模型、基于G-quadruplex的DNA逻辑计算模型、基于DNA自组装的逻辑计算模型、基于其他分子技术和分子材料的DNA逻辑计算模型。首先阐述了DNA逻辑计算的研究背景和研究目的以及现阶段在生物分子检测、疾病诊断、多因素分析和生物成像等领域的应用并简述其相关概念;然后梳理各DNA逻辑计算模型的研究历史和现状,分析各类逻辑计算模型所应用的分子操控技术和分子材料以及优缺点和应用前景;最后归纳总结DNA逻辑计算领域当前研究热点和发展前景,为未来提出全新的计算方式奠定基础,为信息、医疗等领域提供更好的服务。     

DNA计算机算术运算的自装配模型（I）—加法

DNA计算是基于DNA分子生化反应,能够在DNA计算机上实现的算法。它具有高度并行性、容量大、速度快等特点。同传统电子计算机一样,它也是以加、减、乘、除等简单算术运算和异或等逻辑运算为基本运算单元。在Labean加法的基础上,设计了通用的N进制的并行加法DNA自装配模型,算法的时间复杂度为O（1）,空间复杂度为O（n）。在此基础上又设计了一位数连加的DNA自装配模型,为今后的并行乘法奠定了基础。算法的主要优点在于编码简单、效率高,且具有通用性。     

DNA自组装的可满足性问题模型

DNA自组装技术在DNA计算和纳米技术领域都发挥着极其重要的作用,许多小规模NP完全问题都可以通过自组装模型得以解决.文中以可满足问题为模型,通过构造范式中变量的特殊补链,使其与初始数据库中初始DNA链发生杂交反应,形成发夹结构,利用形成发夹结构的DNA链与没形成发夹结构的DNA链长度不同的特点,通过凝胶电泳将这些带发夹的DNA链提取出来;然后加入与这些特殊补链完全互补的DNA链,在一定温度下,通过碱基互补配对原则,发夹结构又将被重新打开.该模型充分利用了DNA分子间的自组装能力,在计算过程中只需要用到凝胶电泳操作,在一定程度上大大减少了因生物操作过多而引起的各种实验误差.     

粒度逻辑运算下的粗糙集模型

将粗糙集理论、逻辑运算与粒度计算进行嫁接,得到了粒度逻辑运算下的粗糙集理论模型。对粒度逻辑运算下的粗糙集进行了形式化的定义,讨论并证明了相关性质。同时,讨论了知识的粗细与基于粒度逻辑运算的粗糙集之间的关系,这为进一步研究基于粒计算的知识获取和粒度推理奠定了逻辑基础。     

有界整数规划问题的DNA计算

基于生化反应原理的DNA计算具有强大的并行运算能力,对于解决NP完全问题上具有硅计算机无法比拟的优势,因此对DNA计算的研究具有重要意义.基于荧光标记的策略,提出了约束方程变量分解的概念,通过将约束方程进行分解和增加约束补链的方法,解决了有界整数规划问题.利用荧光猝灭技术,基于DNA计算的新算法具有编码简单和错误率低的特点.     

简单0-1规划问题的动态DNA折纸计算模型

DNA折纸是一种全新的DNA自组装方法。将一个由DNA折纸卡槽、双态DNA机器、DNA行走机器人组装而成的动态折纸应用于求解0-1规划问题。其中DNA折纸卡槽由1条M13脚手架链和202条钉书钉链折叠而成。双态DNA机器分为不修饰和修饰金纳米颗粒两种情况,对应于0-1规划问题约束变量的取值为0或者1。DNA折纸卡槽和DNA双态机器组装成折纸基底。DNA行走机器人是7条单链折叠成的带有粘性末端的DNA折纸。在链的驱动下,DNA行走机器人在折纸基底上顺时针旋转行走,每步旋转120°。DNA行走机器人每走两步,与折纸基底上的DNA双态机器进行链置换,接收修饰的金纳米颗粒。当整个动态行走过程结束,根据透射电镜下DNA行走机器人接收的金纳米颗粒的大小和个数来判断约束变量的取值是否为可行解。该计算模型采用模块化结构,DNA折纸卡槽、双态DNA机器、DNA行走机器人等折纸均单独设计,且采用透射电镜读解,因而提高了模型实现的可行性。     

基于FPGA的多操作位逻辑运算控制器的设计

提出了应用FPGA设计可执行多操作位逻辑运算控制器的思路,该控制器接收到逻辑运算命令与多操作位后,在内部时序脉冲作用下,可以自主完成PLC逻辑运算指令的功能,运算结果传输到系统数据总线.设计多操作位逻辑运算的PLC指令,论述了该控制器的电路构成和基本原理,分析指令在内部时序脉冲作用的执行过程并给出了流程图,应用Verilog HDL语言实现相关硬件的构建和连接,应用梯形图程序进行仿真测试.测试表明:该控制器可以自主完成每条指令的运算,实现了逻辑运算指令的执行与系统其他功能模块的并行处理,提高了PLC执行指令序列的速度.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.