Generalizing the CHOKe flow protection

This paper proposes a simple and stateless active queue management (AQM) scheme, called geometric CHOKe (gCHOKe), to protect responsive flows from unresponsive ones. gCHOKe has its root in and is a generalization of the original CHOKe. It provides an additional power of protection, achieved by introducing an extra flow matching trial following each successful flow comparison of packets. The maximum number of comparisons permitted for an arrival can be controlled by a parameter called maxcomp. The quality of flow protection improves with maxcomp. Compared to the plain CHOKe (which is just the simplest case of gCHOKe), our analysis and simulations show that the scheme can achieve over 20% improvement in the bounds of both bandwidth and buffer space used by an aggressive flow. In addition, up to 14% of the total link capacity can be saved from the unresponsive flow, allowing responsive or rate-adaptive flows to obtain a better share of resources in the router.     

四川盆地含膏盐红层特征及坝基工程地质问题(Ⅱ)

本文探讨了四川盆地含膏盐红层类岩溶作用引起的坝基工程地质问题,首先是地下水化学成分的改变及其对水工结构混凝土的腐蚀作用及坝基渗漏问题,然后确定了表征类岩溶作用强度的类岩溶强度因子(k).最后,通过类岩溶岩体Vp与主要岩体工程力学指标,诸如:允许承载力fak、抗剪(断)摩擦系数f(f')、变形模量(E0)的回归关系,探讨了类岩溶作用对坝基岩体弱化的作用.     

求解泊松方程的紧致修正法

将紧致格式与低阶格式结合,构造紧致格式的修正项,并将修正项加入到源项中进行求解,得到了一种基于非均分网格求解泊松方程的紧致修正法,且将该方法应用于二维和三维泊松方程的数值求解中。数值计算结果表明:紧致修正方法的精度高于经典方法的精度,但四阶紧致修正方法比二阶经典方法对网格的依赖性强。     

Chemical reaction optimization with greedy strategy for the 0–1 knapsack problem

The 0–1 knapsack problem (KP01) is a well-known combinatorial optimization problem. It is an NP-hard problem which plays important roles in computing theory and in many real life applications. Chemical reaction optimization (CRO) is a new optimization framework, inspired by the nature of chemical reactions. CRO has demonstrated excellent performance in solving many engineering problems such as the quadratic assignment problem, neural network training, multimodal continuous problems, etc. This paper proposes a new chemical reaction optimization with greedy strategy algorithm (CROG) to solve KP01. The paper also explains the operator design and parameter turning methods for CROG. A new repair function integrating a greedy strategy and random selection is used to repair the infeasible solutions. The experimental results have proven the superior performance of CROG compared to genetic algorithm (GA), ant colony optimization (ACO) and quantum-inspired evolutionary algorithm (QEA).     

Development of a quadruped walking robot AiDIN-III using biologically inspired kinematic analysis

This paper presents a bio-inspired mechanism design for a quadruped walking robot. The approach is derived from the observation on the behaviors of quadruped locomotion, skeletal structure, and the study on the stability of walking based on morphological analysis. In the first, we define the design parameters such as the dimensions of the body and limbs, the center of mass position, and locomotion mechanisms based on surveys on the literatures from biologists. Then, by using the parameters, we propose an useful framework for determining the design parameters of a quadruped walking robot. For implementations, we manufacture a dog-type self-contained quadruped walking robot, named AiDIN-III (Artificial Digitigrade for Natural Environment version III) and the effectiveness of the proposed idea is validated via experimental works.     

超差特征量指标集约束下PID调节器的满意优化

针对一类具有目的域的控制系统,提出将一组由滞留时间、超差时间以及随机穿越周期时间等构成的超差特征量指标纳入满意PID调节器的目标函数集中进行研究。将PID调节器的参数设计转化为局部状态反馈问题,推导出带状目的域下超差特征量指标的解析表达式,并分析了其与稳定裕度、动态误差系数以及稳态输出方差指标之间的相容性;当上述指标相容时,给出了一种利用双群体机制下的差分进化算法和内点法相结合对PID调节器参数进行优化求解的策略;数值算例表明了所提方法的有效性。     

分布式系统中的资源发现机制综述

资源发现问题亦即由给定的资源描述找到满足该描述的资源地址。如何快速并且准确地从分布存储的资源中找到所需的资源,是一个挑战性的问题。传统的网格资源发现系统采用注册中心和索引的方式,但这些方式不能满足网格系统规模不断扩大的需求。而对等网络是一种扩展性好的分布式系统,采用已有的P2P技术解决网格环境下的资源发现问题是一种有效的途径。介绍了网格系统中的资源发现、P2P系统的资源发现以及基于P2P的网格资源发现系统,并对它们进行了比较。     

谈在.NET平台中DataList控件嵌套的应用

介绍在.NET平台下利用DataList控件的嵌套和绑定数据技术,处理主从关系数据和多列数据等多级关联数据的显示方法和技巧,为网站开发和教学提供一定实用技术支持和帮助。     

浅析网络数据库安全

随着网络的不断发展,网络数据库安全日益凸显,目前网络数据库安全问题存在许多的威胁,本文就针对网络数据库安全策略提出了一些见解,而这些策略对网络数据库安全提供良好的保证.