SoC数据映射中的快速应用程序存储分析方法

片上系统SoC在多媒体信息处理领域中应用广泛.多媒体处理程序中频繁的循环嵌套与多维数组操作严重影响着多媒体处理SoC系统的数据传输与存储效率.根据程序各个部分的存储需求量将程序中数据映射到SoC存储层次上,这是改善SoC系统性能与功耗的必要途径.针对多媒体处理程序,提出一种面向SoC数据映射的快速存储需求量分析方法.在存储需求量分析过程中,提出并使用正交线性有界格对所操作数据的数据域进行划分,并基于相关性进行存储需求量计算,得到了较为准确的存储需求量,并大幅度减少了分析时间.     

多媒体对象服务器机制

在多媒体、Internet以及分布式应用环境下 ,需要一个完整而全新的数据库开发环境 ,使用面向对象数据库是存储复杂多媒体数据的最有效的方法。分析了在以上环境下多媒体对象服务器的结构和运作机制 ,并给出对象数据库Jasmine服务器的实例。由于对象具有很强的可再生性和适应性 ,因而建立在数据对象基础上的客户应用程序灵活且易于管理。     

基于ATM的多媒体服务器初探

多媒体技术和多处理器技术飞速发展,多处理器将在多媒体环境下用作服务器。当前的顺不能内部处理我媒体通信,有效地给处理和存储子系统分配网络的高带宽,满足多媒体信息实时演播要求。讨论了３种规模可扩展、基于子系统的多媒体服务器系统结构,利用ＡＴＭ互连机制解决这些问题。     

在线数据存储——你存储了吗?

随着信息技术的发展,网络中的视频、音频的内容更加丰富,人们工作、生活中需要存储的多媒体数据日益增长。信息社会带来了信息存储和保护的一些问题:电脑很容易受到硬盘驱动器崩溃或病毒的攻击;数据备份繁琐;数据发生故障时恢复能力差等。在线数据存储这几年得到了快速发展。在线数据存储是一种技术,可以让使用者的资料存储在互联网上。在线数据存储不仅提供了额外弹性源,供存放资料,而且还可以作为备份机制,并提供了有效的方法共享数据给别人。     

基于多媒体技术的地理信息系统开发环境

本文介绍了基于多媒体技术的地理信息系统（ＧＩＳ）开发环境的设计思想与实现方法，以及基于该环境开发的电信，电业应用系统。系统以面向对象的多媒体技术为基础，实现了多媒体数据库，信息类管理机制，窗口界面机制及增量快速原型生成机制。     

多媒体邮件的发送系统存储机制研究

针对传统邮件系统收发多媒体邮件时存在的不足,提出一种发送系统存储机制。该方案使用多媒体Server和客户端应用程序,利用流媒体技术,使视听信息从发送系统直接传送到接收者,节省了中间环节的带宽和存储空间。讨论了实现这种机制的方法,最后针对多媒体邮件的安全性问题提出了解决方法。     

互动式游戏数据库的数据存储与管理

互动游戏的实时与动态交互性要求游戏能够快速调用存储介质中的图像、语音、动作等多媒体数据,作为游戏角色参与游戏。针对该特性,设计适合于互动游戏的专用数据库管理软件,构建能够存储和管理多媒体数据的基于关系的数据库模型,从物理存储和逻辑语义2个方面探讨基于Hash的多媒体数据的存储与管理方法。     

浅谈现代多媒体教室智能化管理系统的设计与实现

根据现代多媒体教室管理需求,借助校园网应用多媒体教室智能化管理系统,通过MC900智能多媒体控制系统将教务智能排课系中的排课数据存储到各多媒体教室电子锁的存储器中,读卡器根据存储器中的排课信息,按时开锁并触发中控联动控制机制,实现多媒体教室智能化管理。     

IDC网站运营支撑系统设计与实现

针对万兆网络流量采集容易丢包和海量数据难以存储的问题,设计一种特定的网络测量方法及数据存储方式,其中包括在Linux内核TCP/IP协议栈中添加快速匹配算法以实现IP快速过滤、分布式多点采集机制对不同地点服务器进行检测、多粒度聚合对海量数据进行存储。在运营商实地环境下进行测试,结果表明,该系统能够达到预期的功能设计目标。     

多媒体流的轻量级TCP/IP协议栈的优化

提出了一种在轻量级 TCP 协议栈上实现的零存储丢包重传机制,并设计了一种专门适用于多媒体视频流的坚持计时器。这两种机制的共同作用可以有效提高多媒体数据流在嵌入式系统上传输的效率和稳定性,避免网络拥塞。同时,针对不同的传输环境,对改进后的 TCP/IP 轻量级协议栈进行了效率和稳定性的测试,测试结果表明,经优化后的协议栈在不同的网络拥塞可以保持正常工作。     

Fast proxy delivery of multiple streaming sessions in shared running buffers

With the falling price of memory, an increasing number of multimedia servers and proxies are now equipped with a large memory space. Caching media objects in the memory of a proxy helps to reduce the network traffic, the disk I/O bandwidth requirement, and the data delivery latency. The running buffer approach and its alternatives are representative techniques to caching streaming data in the memory. There are two limits in the existing techniques. First, although multiple running buffers for the same media object co-exist in a given processing period, data sharing among multiple buffers is not considered. Second, user access patterns are not insightfully considered in the buffer management. In this paper, we propose two techniques based on shared running buffers in the proxy to address these limits. Considering user access patterns and characteristics of the requested media objects, our techniques adaptively allocate memory buffers to fully utilize the currently buffered data of streaming sessions, with the aim to reduce both the server load and the network traffic. Experimentally comparing with several existing techniques, we show that the proposed techniques achieve significant performance improvement by effectively using the shared running buffers.     

Multimedia object modeling and storage allocation strategies

The improvements in disk speeds have not kept up with improvements in processor and memory speeds. Many techniques have been proposed and utilized to maximize the bandwidths of storage devices. These techniques have proven useful for conventional data, but when applied to multimedia data, they tend to be insufficient or inefficient due to the diversified data types, bandwidth requirements, file sizes and structures of complex objects of multimedia data. In this paper, we discuss the design of an efficient multimedia object allocation strategy that strives to achieve the expected retrieval rates and I/O computational requirements of objects; and also effectively balances the loads on the storage devices. We define a multimedia object model, describe the multimedia object and storage device characteristics, the classification of the multimedia objects according to their I/O requirements, and the fragmentation strategies. We use a bipartite graph model for mapping of fragments to storage devices. A cost function based on a disk utilization per allocated space, the amount of free space, and the bandwidth of a storage device is used to determine the optimal allocation for an object's data.     

An intelligent memory caching architecture for data-intensive multimedia applications

With the rapid developments in cloud computing and mobile networks, multimedia content can be accessed conveniently. Recently, some novel intelligent caching-based approaches have been proposed to improve the memory architectures for multimedia applications. These applications often face bottleneck related challenges which result in performance degradation and service delay issues. Intelligent multimedia network applications access the shared data by using a specific network file system. This results in answering the processing related constraints on hard-drive storage and might result in bringing bottleneck issues. Therefore, to improve the performance of these multimedia network applications, we present an intelligent distributed memory caching system. We integrate the multimedia application message passing interface in a multi-threaded environment and propose an algorithm which can handle concurrent response behavior for different multimedia applications. Results demonstrate that our proposed scheme outperforms traditional approaches in terms of throughput and file read access features.

     

一种高效的分布式并行数据库日志机制

减少协议中的强制写次数一直是研究分布式原子提交协议的目标．利用超高速网络与磁盘的数据存取速度差距，可以提出一种高效的协同内存缓存日志机制(cooperating memory cached log mechanism，CMCL)．它通过在事务参与者的内存中相互备份日志而获得日志的可靠性，从而免除强制写．在给出CMCL的原理，并用它改进两阶段提交协议后，对其性能进行了分析和比较，结果表明CMCL机制在适当的环境下是高效的．     

远端内存交换系统的设计与实现

随着高带宽和低延迟的网络的出现,远端内存到本地内存的传输速率大于本地磁盘到本地内存的传输速率,使用远端内存代替磁盘缓存应用程序的数据将成可能。RMSS是一个基于Linux2.4内核的远端内存交换系统,它以内核模块的形式提供给用户。通过RMSS,应用程序可以透明的访问远端内存。根据本文实验结果,得出在快速网络中,使用RMSS会比交换到磁盘的性能要好。本文也对RMSS中的可靠性进行了分析,并提出了几种解决方案。     

一种基于内存服务的内存共享网格系统

内存密集型应用对运行环境的物理内存要求严格,在物理内存不足时将会引发大量磁盘IO,降低系统性能．传统的网络内存致力于在集群内部通过共享空闲节点的物理内存解决该问题,但受集群负载和内部网络影响较大．通过结合网络内存和服务计算、网格计算等技术,提出一种基于内存服务的内存共享网格系统——内存网格,并分析和讨论了实现内存服务的关键技术和算法．内存网格弥补了网络内存的不足,扩展了网格计算的应用范围．通过基于真实应用运行状态的模拟,证明了内存网格与网络内存相比具有性能的提高．     

Improving multimedia systems performance using constant-density recording disks

Multimedia systems store and retrieve large amounts of data which require extremely high disk bandwidth and their performance critically depends on the efficiency of disk storage. However, existing magnetic disks are designed for small amounts of data retrievals geared to traditional operations; with speed improvements mainly focused on how to reduce seek time and rotational latency. When the same mechanism is applied to multimedia systems, overheads in disk I/O can result in dramatic deterioration in system performance. In this paper, we present a mathematical model to evaluate the performance of constant-density recording disks, and use this model to analyze quantitatively the performance of multimedia data request streams. We show that high disk throughput may be achieved by suitably adjusting the relevant parameters. In addition to demonstrating quantitatively that constant-density recording disks perform significantly better than traditional disks for multimedia data storage, a novel disk-partitioning scheme which places data according to their bandwidths is presented.     

Run-time optimization of heterogeneous media access in a multimediaserver

Discrete media (DM) data throughput is vital to systems that need to support the heterogeneity and variety of data found in interactive hypermedia and digital library applications. Therefore, a multimedia server's ability in delivering a high DM data throughput without degrading its CM data throughput deserves more attention. In this paper, we address this issue by optimizing the use of disk bandwidth spent on CM service at run-time and redirecting the saved bandwidth to service DM requests. Based on a new cost model of disk access incurred in CM service, we formulate strategies to control the size of each disk read at run time. These strategies improve the efficiency of each disk access and improve the DM data throughput of a multimedia server, without jeopardizing the CM throughput. Through experimental evaluations, the improvements achieved are demonstrated. Furthermore, efficient control of the allocation of disk bandwidth between DM and CM services over a wide range is also demonstrated     

适应广域网的虚拟机在线迁移模型

针对广域网(WAN)环境下虚拟机(VM)迁移存在的诸多问题提出一种迁移模型。该模型持续检测节点间链路状态,优化磁盘、内存和CPU状态及网络的迁移时序,并采用磁盘周期同步、单向网络隧道及虚拟机本地化等方法。实验表明：模型减少了虚拟机跨WAN迁移的数据量,缩短了网络重定向路径,在模拟实验中迁移的总时间及暂停时间接近于共享存储方式。     

基于文件分时索引的大规模流量实时IoT终端识别算法

随着5G时代的来临,诸如工业区,校园网等开放性园区网络中存在大量的物联网(Internet of Things,IoT)终端,IoT终端由于其数据流量巨大,伪造IoT终端进行网络攻击的问题日益严重.现有IoT终端识别技术在面对海量数据时计算资源的成本逐渐提高.针对以上问题,提出了基于文件分时索引的大规模流量实时IoT终端识别算法.首先,建立内存分时索引元数据;其次,使用文件的分时索引来存储构建会话的中间数据;最后,控制内存分时索引元数据触发从少量文件中提取特征并进行IoT终端识别.实验中,在不损失IoT终端识别算法精度条件下,仅消耗少量磁盘,可将内存消耗降低92%.实验结果表明,该技术能够用于实时IoT终端识别框架中.