K-means算法在大学生消费状况分析中的应用

以运城学院在校大学生为例,对其消费情况进行了抽样调查,并利用K-means算法对调查结果进行了聚类和分析.实验结果表明,每一类学生中影响其消费的因素是有差别的,该分析结果可作为指导各类学生消费的依据.     

TCP和SCTP路由协议的对比研究

为了更好地了解流控制协议—SCTP的相关性能,利用NS-2网络仿真软件,从单路径和多路径两个方面对TCP和SCTP协议进行了比较。实验结果表明,在应对链路恶化的情况下,SCTP协议的吞吐量更大,也具有更高的稳定性,更能满足现在网络高性能传输的要求。     

A novel linearly-weighted gradient smoothing method (LWGSM) in the simulation of fluid dynamics problem

This paper describes a novel linearly-weighted gradient smoothing method (LWGSM). The proposed method is based on irregular cells and thus can be used for problems with arbitrarily complex geometrical boundaries. Based on the analysis about the compactness and the positivity of coefficients of influence of their stencils for approximating a derivative, one favorable scheme (VIII) is selected among total eight proposed discretization schemes. This scheme VIII is successively verified and carefully examined in solving Poisson equations, subjected to changes in the number of nodes, the shapes of cells and the irregularity of triangular cells, respectively. Strong form of incompressible Navier–Stokes equations enhanced with artificial compressibility terms are tackled, in which the spatial derivatives are approximated by consistent and successive use of gradient smoothing operation over smoothing domains at various locations. All the test cases using LWGSM solver exhibits its robust, stable and accurate behaviors. The attained incompressible LWGSM solutions show good agreements with experimental and literature data. Therefore, the proposed LWGSM can be reliably used for accurate solutions to versatile fluid flow problems.     

Development of an image-based model for capillary vasculature of retina

The paper presents a method of development of a detailed network model to represent retinal capillary vasculature. The capillary model is a circular mesh consisting of concentric rings with an increasing diameter. Each of the rings has uniformly distributed bifurcation nodes to represent capillary vessels. The model is customized using the data that has been measured from confocal microscopic images of a mouse retina. The capillary model developed can be connected to networks of larger vessels of the vasculature such as arterial and venous networks to form a complete model of the retinal network. A method to automate such interface connections between capillary and other vascular networks using connecting vessels (i.e., pre-capillary and post-capillary) is also presented in the paper. Such a detailed image-based capillary model together with the arterial and venular networks can be used for various circulation simulations to obtain accurate information on hemodynamic quantities such as the spatial distribution of pressure and flow in the vasculature for both physiological and pathological conditions. The method presented for the development of the capillary model can also be adopted for vasculatures of other organs.     

基于3G无线网络的工业监控系统设计

设计了一种基于3G无线网络工业监控系统,把自动控制技术和先进的移动通信技术相结合,使用便携手机作为监控终端,利用3G无线网络实时清晰地传递工业现场的动态信息,并将监控人员控制命令下达给现场设备,管理设备运行,针对控制功能提供权限认证,当遇到异常情况时,及时发出报警信息。     

ADS5287及其在MIMO接收机中的应用

介绍了TI公司模数转换器ADS5287的性能特点.用ADS5287作为模数转换器设计了MIMO中频接收机电路,完成了系统的PCB设计,并使用Hyperlynx软件中的Boradsim工具对设计中重要的高速信号线做了信号完整分析.     

一种使用视觉反馈与行为记忆的蚁群优化算法

在分析现有改进算法的基础上,结合视知觉及认知心理学的相关理论,提出一种具备视觉反馈与行为记忆学习能力的新型蚁群算法:首先,建立视觉模型使得蚂蚁能够通过人工视觉感知周围目标城市的分布,用视知觉修正信息素噪声,提高蚂蚁探索质量;其次,建立行为记忆学习模型,使蚂蚁能够从已经走过的局部最优路径中提取经验来指导周游活动,加快算法收敛速度并强化寻优能力.经过与传统改进策略比较发现,新算法在求解质量与求解时间上均有明显改进.     

一种基于Web的层次编码处理模块设计

针对目前大多数Web应用系统对层次编码处理相对简单导致用户操作不便的问题,开发了一个基于Web的层次编码处理模块,详细介绍了其设计与实现思想.其操作简便,易实现,对开发B/S结构的管理信息系统在处理层次编码时,提供了一个很好的解决方案.     

芹菜素和山萘酚对细胞色素CYP1A2抑制机理研究

目的:我们先前的体外肝微粒体抑制活性实验,已证实芹菜素和山萘酚对细胞色素CYP 1A2有较强的抑制作用。然而,其抑制机理仍然未知。分子模拟方法能更好了解这2个天然产物对1A2的抑制机理。方法:采用分子对接、分子动力学模拟及结合自由能计算的方法,研究它们对1A2的抑制作用。结果:芹菜素和山萘酚对1A2的预测结合自由能分别是-18.01和-16.40 kcal/mol,这与实验抑制活性结果一致。在1A2结合口袋中,残基呈平面性排列,与平面芹菜素和山萘酚存在紧密的范德华和疏水相互作用,因而小分子有较强的抑制作用。此外,活性位点残基也与小分子发生氢键和盐桥等相互作用,使小分子在结合口袋中的位置得到固定。     

不同模拟方法研究β-环糊精识别对映体分子

手性对映体分子的物理化学性质基本相同,其旋光性差异直接影响生物体内生理和药理的活性.本文以Builder和Discover-3模块为基础,在InsightⅡ平台上模建并优化,采用Dock刚性、柔性对接及GOLD柔性对接的方法,模拟了β-环糊精识别手性对映体的能力.通过利用DMS程序计算环糊精分子溶剂的可接触表面,用SPHGEN程序计算,产生球集,形成环糊精分子活性位点的负像;在环糊精分子上打格点,计算格点能;采用格点的打分函数打分,分子对接,保存分数最高的对接结果等步骤;表明手性识别的预测率从高到低依次是GOLD对接,Dock柔性对接,Dock刚性对接.由于刚性对接过程对映体分子保持刚性,导致手性识别效果最差,故分子柔性的作用不可忽视;GOLD对接在模拟环糊精对对映体手性识别方面要优于Dock对接模拟.因此,用GOLD对接建立了β-环糊精对对映体的手性识别模型,结合能越大,相互作用越强,形成的包合物越稳定.分析模型的结合能组分,以分子识别过程中的氢键作用为模型,则其手性识别预测结果正确率为45.5%:如以分子间氢键作用和范德华作用为预测模型,则其预测正确率为81.8%.表明手性识别的驱动力不仅有氢键的作用,也存在范德华力的作用.