Molecular solutions for minimum and exact cover problems in the tile assembly model

The tile assembly model is a novel biological computing model where information is encoded in DNA tiles. It is an efficient way to solve NP-complete problems due to its scalability and parallelism. In this paper, we apply the tile assembly model to solve the minimum and exact set cover problems, which are well-known NP-complete problems. To solve the minimum set cover problem, we design a MinSetCover system composed of three parts, i.e., the seed configuration subsystem, the nondeterministic choice subsystem, and the detection subsystem. Moreover, we improve the MinSetCover system and propose a MinExactSetCover system for solving the problem of exact cover by 3-sets. Finally we analyze the computation complexity and perform a simulation experiment to verify the effectiveness and correctness of the proposed systems.     

基于运行电能表误差自监测技术研究

电能表作为电能计量计费仪表,用于电网与用户的电量计量和电费结算,其计量性能的准确性、稳定性是核心要求。电能表挂网运行后,受环境、人为等因素影响,其计量误差会发生变化。本文分析了计量误差异常的原因,给出计量误差异常的诊断模型,并针对当前计量芯片的误差自监测功能进行了全面测试和分析。     

滁州市城市公交线路最优化分析

城市化的迅速发展,迫切要求城市公共交通的合理规划。针对公交线路规划设计的特点与目标,本文基于优化理论和GIS技术,结合SPSS数据统计技术,对收集到的2008年12月份滁州市各公交线路客流数据进行分析统计处理,再利用ArcGIS网络分析原理,对公交线路数据进行空间分析,并结合叠加分析原理,分析公交线路各要素的不舍理性。本文主要从城市公交发车频率、公交站点分布、公交线路优化三个方面着手,分析滁州市目前公交线路存在的问题,并针对三个方面进行优化计算和分析,得到滁州市具体公交车发车频率一周分布表以及站点与线路的优化图,给出了具体的解决方法,能从实际角度为该市公共交通规划提供一定的支持,真正意义上的节省线路规划中的人力物力,提高规划效果。     

用VB实现横断面图的自动绘制

在工程建设中,当采用较小间距的断面布置时,就能满足设计对方量计算和标准断面选取的要求,这就需要大量反复的横断面成图.此外,各个设计要求和阶段的不同,所需横断面图的格式和比例就不相同,这就发挥了VB灵活性好的优点,可以根据具体的要求绘制出图形.     

冲击爆炸问题的三维物质点法数值仿真

基于物质点法（Material Point Method,MPM）模拟超高速碰撞和爆炸问题时呈现的特点,概述对MPM及其应用的扩展,包括：将MPM扩展应用于超高速碰撞问题,物质点有限元法（MaterialPoint Finite Element Method,MPFEM）,杂交MPFEM,MPM质点自适应法,基于局部多重背景网格的接触算法和并行MPM算法.在此基础上开发针对冲击爆炸问题的三维显式并行MPM数值仿真软件MPM3D.MPM3D采用C＋＋语言开发,并基于Qt和VTK开发图形用户界面PeneBlast,可在Windows,Linux和Mac OS等多种平台上运行.关于超高速碰撞、侵彻、爆炸、边坡失效和金属切削等问题的大量实例表明MPM3D的可靠性和准确性.MPM3D可作为航天器空间碎片防护、常规武器研发与防护等的有效设计工具.     

GIS支持下的交通沿线土地利用状况分析

着重以交通沿线土地利用为对象的分析研究较少,而此因子在地区的发展中起着很重要的作用。因此,本文基于ArcGIS的空间分析功能与分析建模功能,研究南充市嘉陵区的典型地类——工矿仓储用地,耕地,农村居民点用地相对于道路交通网络的聚集程度,分析了该地区的城市化发展水平,为该区的城市化发展提供建议。     

抛物样条算法在等值线平滑中的应用

在深入研究分段抛物样条算法的基础之上,采用Visual Basic. NET2005开发语言,最终设计并实现了基于该算法的闭合和不闭合的平滑抛物样条曲线绘制方法。并将该算法应用到雨量等值线的平滑中,取得了较为理想的效果。并采用均匀添加型值点的方式,使最终等值线的绘制更加科学化,避免相交情况的出现。     

Robust exponential passive filtering for uncertain neutral-type neural networks with time-varying mixed delays via Wirtinger-based integral inequality

This paper is concerned with the problem of the robust exponential passive filter design for uncertain neutral-type neural networks with time-varying mixed delays. Our aim is to design a Luenberger-type filter for estimating information about the neuron states, which is required in some applied areas. By constructing an appropriate Lyapunov-Krasovskii functional and using the Wirtinger-based integral inequality to estimate its derivative, a delay-range-dependent and delay-rate-dependent criterion is presented to ensure the augmented filtering dynamic system to be robustly exponentially stable and passive with an expected dissipation. Since the criterion is presented in the form of linear matrix inequalities with nonlinear constraints, a cone complementarity linearization algorithm is proposed to determine the filter gain from solution to the nonlinear problem. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.     

Power allocation for OFDM-based cognitive heterogeneous networks

In this paper,the capacity maximization and the spectrum utilization efficiency improvement are investigated for the Pico cells in broadband heterogeneous networks.In frequency-reuse model,the users attached to Macro base station are usually viewed as primary users,and those attached to Pico base station should be regarded as cognitive radio(CR) users.As both the primary users and the CR users communicate in parallel frequency bands,the performance of the system is limited by the mutual inter-carrier interference(ICI).In order to control ICI and maximize the achievable transmission rate of the CR users,an effective power allocation scheme is proposed to maximize the transmission rate of the CR users under a given interference threshold prescribed by the primary users.By transforming this suboptimal solution into an innovative matrix expression,the algorithm is easier to perform in practice.The simulation results demonstrate that the proposed algorithm provides a large performance gain in Pico cell capacity over the non-cooperative and equal power allocation schemes.     

六工位悬链式抛丸光饰清理机的开发与应用

无论是一般铸造,还是经过精铸后的铸铝件,其表面都会因为带有脱膜剂或冲压油等附着物而产生局部不光洁的现象,同时工件为下一道工序需要具有一定的表面粗糙度,所以需要进行表面抛光处理.用抛丸清理的方法可直接、经济、有效地去除铸铝件表面的附着物,得到细密、均匀、光洁的理想表面.另外,在抛丸器的弹丸中加入铝粉或是镁粉,可以对工件表面进行有效的光饰,使工件表面呈现十分美观的金属光泽.针对以上应用,本文介绍了一种新型的悬链式抛丸光饰清理机,其六个清理工位的设计,实现了同类设备中史无前例的高生产率.