Linux下一种多核网络服务器模型设计与实现

传统的基于Linux操作系统的网络服务器程序在高负载情况下不能充分利用多核服务器硬件资源,其原因主要在于没有找到一种高效的服务器编程解决方案.为了解决这一问题,在分析了线程池技术和linux 2.6内核下的I/O多路复用技术各自的优缺点的基础上,设计并实现了一种在多核服务器平台上结合线程池和I/O多路复用的高性能网络服务器编程模型.通过实验表明,新的编程模型相对于线程池模型和单纯的I/O多路复用模型,其任务平均响应时间只占其它两种模型的8%和29%,而其平均吞吐量则达到了其它两种模型的8.4倍和1.9倍.     

地理信息服务网站服务器集群负载均衡技术应用研究

在分析基于互联网的地理信息在线服务特点和网站服务质量需求的基础上,对服务器负载均衡的构建方式、调度算法进行了讨论,给出了地理信息服务网站服务器两层负载均衡的设计模型,描述了Web服务器负载均衡的设备部署、调度算法和健康性检测等方面的设计内容;同时,讨论了文件和关系型数据库服务器负载均衡的设计思路及调度算法的具体应用。     

基于集群技术的“天地图”运行支持环境设计

在分析基于互联网的地理信息在线服务特点和网站服务质量需求的基础上,对服务器高可用性、负载均衡技术与构建方式、调度算法进行了讨论,给出了天地图网站高可用性服务器集群和负载均衡服务器集群的设计模型,描述了相关的设备部署、调度算法和健康性检测等方面的设计内容;同时,讨论了文件和关系型数据库服务器集群的具体应用.     

LINUX虚拟服务器集群模型及其任务分配算法的探讨

在介绍集群和Linux虚拟服务器集群的基础上,抽象出了LVS集群的系统模型并对模型进行了描述.在此基础上又对LVS集群已经实现的8种算法进行了分析,指出了它们一个共同的不同之处,并就此提出了根据任务大小进行任务分配的思想.     

Web服务器端二进制验证系统设计

随着网络技术的不断发展,Web信息系统的安全性与服务器端的系统安全应用紧密联系在一起,为了保证存在于Web服务器上的服务过程,例如网络数据库、数据库应用系统、文件服务等在网络应用中不被非法用户使用,提出通过引入二进制验证文件的方法,利用设计的软件对服务器端的ASP程序进行验证,并且在成功连接数据库后实时地对验征文件进行验证码位修改及加密.通过这种方法可以达到对ASP连接过程安全控制的目的.     

用PLC技术改造彩电偏转绕线机

本文介绍ＰＬＣ技术在改造偏转机的应用原理和方法,探讨了ＰＬＣ在现代工业控制、技术改造等方面的有关问题。     

Research on purification and modification of I/S bentonite

Analyzing raw material's structure and performance of bentonite from Panzhihua in Sichuan, the authors think that it is adequate for agglomerant of iron smelting. According to its composition and property we have researched the purification and modification of I/S bentonite under conditions of different dispersants and sodium agent. XRD test result reveals that the essential minerals of Panzhihua bentonite are I/S mixed-layer ones, and FTIR analysis shows that when adding 1 5% sodium pyrophosphate to the bentonite slurry during purification, the composition of quartz in bentonite decreases to less than 4% and I/S is more than 90%. The optimized modification technic conditions are Na2CO3 (4%) and CMC-Na (3%) as modified agents, the clay and water are 10 vs. 1, and the temperature is 75℃. It is 40 min for stirring time and reacting time is 4 h. Under the conditions we can get the modified I/S bentonite with colloid index more than 500 ml/15 g.     

pGTIOL:GeoTIFF数据并行I/O库

在地理栅格并行计算处理中,数据I/O 已成为制约计算性能的主要瓶颈之一。本文针对该问题,首先分析广泛应用于GIS 栅格数据存储的GeoTIFF 格式,重点研究数据的2 种存储模式(即条带存储与块状存储),并根据这2 种存储方式,分别构建了栅格数据从逻辑结构向物理存储结构的映射模型。然后,针对地理空间并行计算的需要,提出了栅格数据的并行读写框架,并利用MPI 并行I/O 技术的文件视图方法,实现了GeoTIFF 数据并行I/O库(pGTIOL)。结果表明,对比开源栅格空间数据转换库(GDAL)的主从I/O 模式,本文提出的pGTIOL 准确读写数据,具有更高的性能。该库隐藏了底层并行I/O 的细节,提供简单易用的并行读写GeoTIFF 栅格数据的接口,支持多数据类型和多种空间分割,实现了对条带存储与块状存储数据的异步并行读写,从而满足动态负载均衡的需求。     

Research on purification and modification of I/S bentonite

Analyzing raw material＇s structure and performance of bentonite from Panzhihua in Sichuan, the authors think that it is adequate for agglomerant of iron smelting. According to its composition and property we have researched the purification and modification of I/S bentonite under conditions of different dispersants and sodium agent. XRD test result reveals that the essential minerals of Panzhihua bentonite are I/S mixed-layer ones, and FTIR analysis shows that when adding 1.5% sodium pyrophosphate to the bentonite slurry during purification, the composition of quartz in bentonite decreases to less than 4% and I/S is more than 90%. The optimized modification technic conditions are Na2CO3 （4%） and CMC-Na （3%） as modified agents, the clay and water are 10 vs. 1, and the temperature is 75℃. It is 40 min for stirring time and reacting time is 4 h. Under the conditions we can get the modified I/S bentonite with colloid index more than 500 nd/15 g.     

Linux 防火墙的研究与设计

阐述了Linux2．4内核的防火墙Linux的原理，并分析了netfilter的设计与实现，叙述了Linux的动态地址转换，介绍了在Linux下基于netfilter架构如何开发自己的防火墙并给出具体实例。     

Research and development on foam breaking and recycling technology in air-foam drilling

In recent years, air-foam combining the advantages of both liquid and air drilling has been utilized as a drilling medium. Air-foam drilling has proved its efficiency in numerous situations where serious problems were encountered, such as in fractured formations and depleted or high permeable zones. However, the major disadvantage of air-foam drilling system is that the foam can only be used once, so that an extremely large pit is required to contain the foam to allow sufficient room for cuttings and for the foam to dissipate. Moreover, it needs enormous volume prepared, consuming abundance of water and ingredient additives, which results in the high cost of foam drilling. The recycling foam fluid by using foam breaking technology is the only effective method to solve these problems associated with the known foam drilling. Various types of equipment and technique have been employed to suppress foam formation in biological and process equipment in foam drilling. The study described various methods of foam breaking technology, and the trend of the foam breaking technology for foam drilling is discussed.     

Research and development on foam breaking and recycling technology in air-foam drilling

In recent years, air-foam combining the advantages of both liquid and air drilling has been utilized as a drilling medium. Air-foam drilling has proved its efficiency in numerous situations where serious problems were encountered, such as in fractured formations and depleted or high permeable zones. However, the major disadvantage of air-foam drilling system is that the foam can only be used once, so that an extremely large pit is required to contain the foam to allow sufficient room for cuttings and for the foam to dissipate. Moreover, it needs enormous volume prepared, consuming abundance of water and ingredient additives, which results in the high cost of foam drilling. The recycling foam fluid by using foam breaking technology is the only effective method to solve these problems associated with the known foam drilling. Various types of equipment and technique have been employed to suppress foam formation in biological and process equipment in foam drilling. The study described various methods of foam breaking technology, and the trend of the foam breaking technology for foam drilling is discussed.     

RESEARCH ON DROUGHT / FLOOD INFLUENCE FACTORS IN CHINA

In the fifth paper listed in the references, East China was divided into eight drought/ flood regions. But we, taking earth rotation velocity, sunspots, southern oscillation, etc. as the influence factors, through step-wise regression analysis and typical analysis, discussed drought/ flood influence factors of the eight regions. On the basis of them, applying spectrum analysis, we calculated the cycles of every influence factor variation and cycles of drought/ flood variations of every region as well as cycles of vibration between them. The results indicate that the drought/ flood influence factors of East China are southern oscillation, earth rotation velocity, etc. Specially, the influence of EL-Nino is more evident to drought/ flood in most regions than that of others. Generally, there are good correlations between the year of EL-Nino and the year of drought/ flood in most regions. The ways of these factors influencing drought/ flood are shown in lag correlation, by 2-5-year high-frequency vibration