Mobile Edge Computing Servers Deployment with Improved Genetic Algorithm in Cellular Internet of Things

Mobile edge computing(MEC)provides services to devices and reduces latency in cellular internet of things(IoT)networks.However,the challenging problem is how to deploy MEC servers economically and efficiently.This paper investigates the deployment problem of MEC servers of the real-world road network by employing an improved genetic algorithm(GA)scheme.We first use the threshold-based K-means algorithm to form vehicle clusters according to their locations.We then select base stations(BSs)based on clustering center coordinates as the deployment locations set for potential MEC servers.We further select BSs using a combined simulated annealing(SA)algorithm and GA to minimize the deployment cost.The simulation results show that the improved GA deploys MEC servers effectively.In addition,the proposed algorithm outperforms GA and SA algorithms in terms of convergence speed and solution quality.

Adaptive Load Balancing for Parameter Servers in Distributed Machine Learning over Heterogeneous Networks

In distributed machine learning(DML)based on the parameter server(PS)architecture,unbalanced communication load distribution of PSs will lead to a significant slowdown of model synchronization in heterogeneous networks due to low utilization of bandwidth.To address this problem,a network-aware adaptive PS load distribution scheme is proposed,which accelerates model synchronization by proactively adjusting the communication load on PSs according to network states.We evaluate the proposed scheme on MXNet,known as a realworld distributed training platform,and results show that our scheme achieves up to 2.68 times speed-up of model training in the dynamic and heterogeneous network environment.

An Efficient Framework for Utilizing Underloaded Servers in Compute Cloud

In cloud data centers,the consolidation of workload is one of the phases during which the available hosts are allocated tasks.This phenomenon ensures that the least possible number of hosts is used without compromise in meeting the Service Level Agreement(SLA).To consolidate the workloads,the hosts are segregated into three categories:normal hosts,under-loaded hosts,and over-loaded hosts based on their utilization.It is to be noted that the identification of an extensively used host or underloaded host is challenging to accomplish.Thresh-old values were proposed in the literature to detect this scenario.The current study aims to improve the existing methods that choose the underloaded hosts,get rid of Virtual Machines(VMs)from them,andfinally place them in some other hosts.The researcher proposes a Host Resource Utilization Aware(HRUAA)Algorithm to detect those underloaded and place its virtual machines on different hosts in a vibrant Cloud environment.The mechanism presented in this study is contrasted with existing mechanisms empirically.The results attained from the study estab-lish that numerous hosts can be shut down,while at the same time,the user's workload requirement can also be met.The proposed method is energy-efficient in workload consolidation,saves cost and time,and leverages active hosts.

Graph Partitioning Method to Determine Servers Placement in CDN

To determine CDN cache servers'placement reasonably,an idea that using graph partitioning to solve the problem was put forward through theoretical analysis and the specific algorithm of partitioning was researched. The concept of graph partitioning for CDN was defined. The conditions of graph partitioning for CDN were demonstrated: the sum of the weights of the nodes in each subarea is as close as possible; edge cut between the subareas is as large as possible; internal nodes in each subarea are connected as far as possible. By reference to light vertex matching algorithm of graph partitioning for network simulation,a multilevel k-way algorithm of graph partitioning for CDN was proposed. The maximized edge cut k-way KL refinement algorithm was discussed. Graph partitioning is a feasible way to solve the problem of CDN servers'placement. Multilevel k-way algorithm is a feasible algorithm for CDN graph partitioning.

The Configuration Strategies on Caching for Web Servers

The Web cluster has been a popular solution of network server system because of its scalability and cost effective ness. The cache configured in servers can result in increasing significantly performance, In this paper, we discuss the suitable configuration strategies for caching dynamic content by our experimental results. Considering the system itself can provide support for caching static Web page, such as computer memory cache and disk＇s own cache, we adopt a special pattern that only caches dynamic Web page in some experiments to enlarge cache space. The paper is introduced three different replacement algorithms in our cache proxy module to test the practical effects of caching dynamic pages under different conditions. The paper is chiefly analyzed the influences of generated time and accessed frequency on caching dynamic Web pages. The paper is also provided the detailed experiment results and main conclusions in the paper.

On One Model of Multichannel Queuing System with Unreliable Repairable Servers and Input Memory

The work deals with the development of analytical model of multichannel technical queuing system with unreliable servers and input memory where server failure flows and incoming request flows comply with Poissonian laws, while the flows of failed facilities repairs and flows of incoming requests comply with exponential laws of probability distribution. Random process of system change-over is a Markovian process with continuous time and discrete states. Relations binding basic parameters and output characteristics of the system indicated are obtained as probabilities of system staying in the given moment in one of the possible states. The proposed model is the most generalized compared to some models known in literature which could be considered as special cases of the considered model.

Unemployment Period Approach with Infinite Servers Queue Systems

With results on the infinite servers queue systems with Poisson arrivals - M｜G｜∞ queues - busy period, it is displayed an application of those queue systems in the unemployment periods time length parameters and distribution function study. These queue systems are adequate to the study of many population processes, and this quality is brought in here. The results presented are mainly on unemployment periods length and their number in a certain time interval. Also, some questions regarding the practical applications of the outlined formulas are briefly discussed.

Research on the High Robustness JavaEE Enterprise Development Mode based on Hadoop and Cloud Servers

In this paper, we conduct research on the high robustness JavaEE enterprise development mode based on Hadoop and cloud servers. The current virtual machine real-time migration can only achieve manual migration, and cannot achieve full-automatic migration. In other words, when the server overload requires the administrator to artificially select a low-load host, and then hit migration command to implement the migration. In recent years, the Hadoop is becoming popular, and the read performance of the data is measured in terms of the time overhead for reading the required data. The key to reducing read time is to optimize that Hadoop cloud data read time and the RDBMS data query time. This paper integrates the mentioned techniques to construct the novel JavaEE enterprise development pattern that will promote the further development of the related techniques.

利用Delphi中Servers组件结合Word模板实现某些特殊功能的打印需求(一)

一、引言 在实际工作中,用户常常会提出某些特殊打印需求,比如各种证件、证明文件以及带有统计功能的数据库报表等等.

利用Dephi中Servers组件结合Word模板实现某些特殊打印报表需求(二)

一、引言 现实生活当中数据库的打印需求是相当多的,各种形式的打印报表都有,笔者不可能对这些报表一一列举并写出源代码,所以举这个例子是希望能起到抛砖引玉的作用,只要读者用心去体会其中的语句,一定会有所收获!

Rehabilitative Environment for Prison Servers

A prison can be something different as ordinary people imagine. It can be a therapeutic and rehabilitative environment, a place where human beings can learn to cope with the stressful situations they could not deal with in their past. That is what happens in the Rencheng prison under the administration of Lineng Prison Sub-Bureau of East China’s Shandong Province.

Active Authentication Protocol for IoV Environment with Distributed Servers

The Internet of Vehicles(IoV)has evolved as an advancement over the conventional Vehicular Ad-hoc Networks(VANETs)in pursuing a more optimal intelligent transportation system that can provide various intelligent solutions and enable a variety of applications for vehicular traffic.Massive volumes of data are produced and communicated wirelessly among the different relayed entities in these vehicular networks,which might entice adversaries and endanger the system with a wide range of security attacks.To ensure the security of such a sensitive network,we proposed a distributed authentication mechanism for IoV based on blockchain technology as a distributed ledger with an ouroboros algorithm.Using timestamp and challenge-responsemechanisms,the proposed authentication model can withstand several security attacks such asMan-in-Middle(MiM)attacks,Distributed Denial of Service(DDoS)attacks,server spoofing attacks and more.The proposed method also provides a solution for single-point failure,forward secrecy,revocability,etc.We exhibit the security of our proposed model by using formal(mathematical)analysis and informal analysis.We used Random Oracle Model to perform themathematical analysis.In addition,we compared the communication cost,computation cost,and security of the proposed model with the related existing studies.We have verified the security of the model by using AVISPA tool simulation.The security analysis and computation analysis show that the proposed protocol is viable.

Do ICMP Security Attacks Have Same Impact on Servers?

There are different types of Cyber Security Attacks that are based on ICMP protocols. Many ICMP protocols are very similar, which may lead security managers to think they may have same impact on victim computer systems or servers. In this paper, we investigate impact of different ICMP based security attacks on two popular server systems namely Microsoft’s Windows Server and Apple’s Mac Server OS running on same hardware platform, and compare their performance under different types of ICMP based security attacks.

Customer Joining Behavior and Regulation Strategy in Visible Multi-Server Queues with Synchronous Vacations of Partial Servers

This paper studies customer joining behavior and system regulation strategy in nonexhaustive visible M/M/m queues with synchronous vacations of a part of the servers.Once this part of the servers are idle,they take multiple vacations simultaneously(vacation period).Until there are customers waiting in the queue,they are reactivated and all servers are busy or idle(busy period).The authors call this part of the servers as“partial servers”.In view of the fully visible queue and the almost visible queue,the authors obtain customers’equilibrium joining threshold strategies and their socially optimal joining threshold strategies,respectively,and observe that customer joining behavior in equilibrium generally makes the system overcrowded,which makes the equilibrium social welfare lower than the optimal social welfare.After regulation,interestingly,for optimizing social welfare,the system manager hopes not only customers arriving in vacation period pay attention to the number of partial servers,but also customers arriving in busy period should care about it rather than ignore.Moreover,arranging more servers for vacation does not necessarily lead to the decrease of social welfare on condition that the number of partial servers is close to m.As for the information advantage of the fully visible case,it is not obvious for increasing social welfare and even unfavorable to servers’profit unless the number of partial servers is big enough.Furthermore,given the different composition of social welfare,there exists the optimal number of partial servers and the optimal arrival rate of customers for maximizing social welfare.

二三维一体化GIS Server在城市信息模型(CIM)中的应用

城市信息模型(CIM)是新型智慧城市的数字基础设施和城市数字化转型的关键抓手,而无缝集成二维地理信息、三维模型和建筑信息模型(BIM)等实现二三维一体化是建设城市信息模型(CIM)基础平台中的关键技术。本文在分析研究CIM平台关键技术基础上提出了一套跨平台、自主化、界面化、B/S网络化的二三维一体化GIS Server解决方案,重点介绍该系统的总体框架及关键技术,并展示了其在城市信息模型(CIM)中的应用成效,为CIM基础平台的建设提供借鉴。

基于ESP8266的单片机无线烧写器的设计与实现

为了简化51单片机烧写流程,克服传统单片机有线烧写的弊端,设计了基于ESP8266的单片机无线烧写器。该无线烧写器以ESP8266作为主控单元,通过Wi-Fi网络使用TCP协议与PC上的TCP服务器进行通信,获取烧写BIN文件,然后通过ESP8266内的烧写控制程序,适时对51单片机的电源进行控制,实现51单片机程序的自动烧写。测试结果验证了该设计方案的正确性和可用性。

基于SOA框架的高校人事管理系统设计与实现

文章通过JDK开发工具设计基于SOA框架的高校人事管理系统,该系统采用三层结构,表示层使用GUI图形用户界面优化人机交互体验,数据层选用SQL Server数据库实现数据的分类存储。从功能上看,高校人事管理系统可支持招聘管理、培训管理、薪资管理以及部门管理等功能;设计访问认证保护系统安全,能满足高校人事管理的基本需要。

动态地震监测系统设计及数据处理技术优化

Client/Server作为一种分布式网络协作处理模式,是当前计算机领域内比较热门的处理技术,应用范围也更加宽广。尤其是在图像处理应用方面,通过对Client/Server模式的应用,可实现对动态地震图像的有效处理,将图像画面更加清晰地表现出来,通过图像完成地震现场处理工作。基于此,本文主要对Client/Server模式下的动态地震图像处理系统进行分析研究。该系统从应用效果来看,充分利用现代计算机技术,采用模块化设计方式,为动态地震图像处理提供一种很好的解决方法,从而发挥出地震仪器设备作用,对地震出现展开正确预判,提升通信处理效果,提前做好相关的预防措施。

SQL Server性能优化的技术分析

随着客户端/服务器技术和多层架构的进步,系统效率问题日益引发广泛讨论。由于缺乏数据库管理系统(DBMS)提供的优化方法和工具,以及基于微软技术的数据库管理员和应用程序开发人员的知识,无法对设计和服务执行系统进行优化。文章回顾了提高SQL Server实例性能时需要考虑的目标,并阐述了用于优化查询的技术。

基于Windows Server Failover Cluster的Apache故障转移集群应用实践

在当前互联网时代,Web应用程序的高可用性和可靠性是确保业务持续运行的关键因素。针对Apache Web服务器,介绍了利用Windows Server 2019 Failover Cluster构建Apache故障转移集群的实践方案。通过配置两个节点的故障转移集群,当某个节点发生故障时,Apache服务将自动在另一个节点上重新启动,从而最大程度地减少系统中断的时间,提高Web应用的可用性。详细阐述了集群搭建的具体步骤、配置要点、集群验证方法以及运行时的监控与维护方法,为构建高可用Apache Web服务器提供一种实用的解决方案。