SMSE: A serverless platform for multimedia cloud systems

Along with the rise of domain-specific computing (ASICs hardware) and domain-specific programming languages, we envision that the next step is the emergence of domain-specific cloud platforms. Considering multimedia streaming as one of the most trendy applications in the IT industry, the goal of this study is to develop serverless multimedia streaming engine (SMSE), the first domain-specific serverless platform for multimedia streaming. SMSE democratizes multimedia service development via enabling content providers (or even end-users) to rapidly develop their desired functionalities on their multimedia contents. Upon developing SMSE, the next goal of this study is to deal with its efficiency challenges and develop a function container provisioning method that can efficiently utilize cloud resources and improve the users' quality of service. In particular, we develop a dynamic method that provisions durable or ephemeral containers depending on the spatiotemporal and data-dependency characteristics of the functions. Evaluating the prototype implementation of SMSE under real-world settings demonstrates its capability to reduce both the containerization overhead, and the makespan time of serving multimedia processing functions (by up to 30%) in compare to the function provision methods that are being used in the general-purpose serverless cloud systems.     

基于云制造平台的云资源语义描述研究

为解决通过云制造平台实现资源描述的问题,采用分而治之的思想将云资源细分归类后进行分别描述,提出了一种基于云制造平台的“框架建立-框架获取-资源描述”三阶段的资源语义描述机制。针对web服务类云资源,建立了资源服务与服务请求的本体描述模型,在此基础上设计了服务发现算法。开发了云制造应用平台原型系统,验证了提出的资源描述与发现的方法。     

Characterizing application scheduling on edge,fog, and cloud computing resources

Cloud computing has grown to become a popular distributed computing service offered by commercial providers. More recently, edge and fog computing resources have emerged on the wide-area network as part of Internet of things (IoT) deployments. These three resource abstraction layers are complementary, and offer distinctive benefits. Scheduling applications on clouds has been an active area of research, with workflow and data flow models offering a flexible abstraction to specify applications for execution. However, the application programming and scheduling models for edge and fog are still maturing, and can benefit from learnings on cloud resources. At the same time, there is also value in using these resources cohesively for application execution. In this article, we offer a taxonomy of concepts essential for specifying and solving the problem of scheduling applications on edge, fog, and cloud computing resources. We first characterize the resource capabilities and limitations of these infrastructure and offer a taxonomy of application models, quality-of-service constraints and goals, and scheduling techniques, based on a literature review. We also tabulate key research prototypes and papers using this taxonomy. This survey benefits developers and researchers on these distributed resources in designing and categorizing their applications, selecting the relevant computing abstraction(s), and developing or selecting the appropriate scheduling algorithm. It also highlights gaps in literature where open problems remain.     

图卷积神经网络在点云语义分割中的研究综述

点云数据蕴含丰富的空间信息,可以通过激光雷达、3D传感器等设备大量采集,被广泛应用于自动驾驶、虚拟现实、城市规划和3D重建等领域。点云语义分割作为3D场景理解、识别和各种应用的基础而受到广泛关注。但不规则的点云数据无法直接作为传统卷积神经网络的输入,而图卷积神经网络可以利用图卷积算子直接对点云数据进行特征提取,使得图卷积神经网络已逐步成为点云语义分割领域的一个重要研究方向。基于此,对图卷积神经网络在3D点云语义分割应用中的研究进展进行综述,根据图卷积的类型对基于图卷积神经网络的点云语义分割方法进行分类,按照不同类别对比分析主流方法的模型架构及其特点,描述几个相关点云语义分割领域常用的公共数据集和评价指标,对点云语义分割方法进行总结和展望。     

A survey on the service interoperability in cloud computing: Client-centric and provider-centric perspectives

The vendor lock-in is a prominent issue in cloud computing. It is caused by cloud providers who offer proprietary services, which hinders the cloud interoperability. Client-centric interoperability enables the migration of the data and applications across clouds; it gives the clients control over their workloads and a wider range of service choices. Whereas, provider-centric interoperability allows the providers to collaborate. Thus, providers, who have spare resources, can lend them to other providers who lack computational or storage capabilities to overcome the limitations of their local resources. In this article, we conduct a survey to differentiate between client- and provider-centric interoperability solutions. We aim to provide an up-to-date analysis of the current tendencies and the neglected areas of the cloud interoperability field. Thus, we study the cloud service interoperability evolution through the years. Furthermore, we propose definitions for the intra-cloud and inter-cloud interoperability. Moreover, we propose a taxonomy to classify the cloud interoperability approaches into client-centric and provider-centric categories. Then, for each category, we classify the approaches based on their interoperability environment into single cloud or interconnected clouds. Finally, we analyze and compare the approaches based on multiple criteria. The study reveals the focus on the client-centric solutions and the interoperability in interconnected clouds. We notice more interest in the data and application levels interoperability, mainly, in infrastructure as a service model. We also find that client-centric solutions are, mostly, semantic technologies and brokers. However, provider-centric solutions are middleware, protocols, and standards. We conclude that a generic cloud service interoperability model is needed.     

Straddling the crevasse: A review of microservice software architecture foundations and recent advancements

Microservice architecture style has been gaining wide impetus in the software engineering industry. Researchers and practitioners have adopted the microservices concepts into several application domains such as the internet of things, cloud computing, service computing, and healthcare. Applications developed in alignment with the microservices principles require an underlying platform with management capabilities to coordinate the different microservice units and ensure that the application functionalities are delivered to the user. A multitude of approaches has been proposed for the various tasks in microservices-based systems. However, since the field is relatively young, there is a need to organize the different research works. In this study, we present a comprehensive review of the research approaches directed toward microservice architectures and propose a multilevel taxonomy to categorize the existing research. The study also discusses the different distributed computing paradigms employing microservices and identifies the open research challenges in the domain.     

基于开源软件的云监控平台设计与实现

最近几年,基于云计算的互联网服务迅速增长,数据中心的基础设施和应用资源不断增加。需要及时、高效的监控和管理资源的可用性,保证云服务的可靠性。通过对云监控的内容和特性的研究,提出一种管理云计算资源的云监控系统架构,重点对分布式架构、逻辑处理模块和云监控接口进行设计,实例中完成对私有云中物理主机、虚拟机、应用服务的批量监控,实现数据的存储和展示。     

一种基于海量信息处理的云存储模型研究

提出了一种云环境下海量数据组织与资源共享的存储总模型,该模型包括:结构化、半结构化及其非结构化数据与资源的对应存储方法;能兼顾海量大小数据文件处理的分布式文件系统THDFS;云数据库系统设计模型THCloudDB;云环境下强于MapReduce弱于SQL,以Hadoop++为基础的一种针对互联网海量数据文件处理且具有语义计算效能的计算模型THMapReduce;针对THDFS及其THCloudDB的具有语义效能的智能挖掘分析工具THBI;最后以"清华通"为案例分析了该模型平台的具体应用.     

基于云综合方法的三支群决策模型

在三支决策问题中，领域专家群决策是一种确定损失函数的最直接方法。相较于体现单一不确定性的语言变量模型和模糊集模型，云模型描述的专家评价更能够反映认知过程中复杂的不确定性形式，并能通过云综合的方法获得综合评价函数。但当前的云综合方法仅对数字特征进行简单的线性组合，缺乏对概念语义差异上的描述，难以获得令人信服的结果。因此首先证明了在云模型的距离空间中赋权距离和是一个凸函数，并将综合云模型定义为此函数的最小值点。然后，将该定义推广到多个云模型的场景下，提出了一种新的云综合方法——基于密度中心的云综合方法。群决策过程中，该方法在保证综合评价与基础评价之间的相似度最高的同时获得最精确的综合评价，为损失函数的确定提供了一种新的语义解释。实验结果表明，在与简单线性组合和合理粒度方法对比中，该方法所确定的损失函数使得三支决策中的误分类率最低。     

Integration of grid,cluster and cloud resources to semantically annotate a large‐sized repository of learning objects

The Universia repository is composed of more than 15 million of educational resources. The lack of metadata describing these resources complicates their classification, search and recovery. To overcome this drawback, it was decided to semantically annotate the available educational resources using the ADEGA algorithm. For this objective, we selected the DBpedia, a cross‐domain linked data composed of more than 3.77 million ‘things’ with 400 million ‘facts’, in order to make sure that the wide range of Universia topics are covered by the ontology. However, this kind of process is extremely expensive from a computational point of view: more than 1600 years of CPU time was estimated to achieve it. In this paper, parallel programming techniques and distributed computing paradigms are combined in order to achieve this semantic annotation in a reasonable time. The cornerstone of this proposal is a resource management and execution framework able to integrate heterogeneous computing resources at our disposal (grid, cluster and cloud resources). As a result, the problem was solved in less than 180 days, demonstrating that it is perfectly feasible to exploit the advantages of these computing models in the field of linked data. Copyright © 2014 John Wiley & Sons, Ltd.     

基于本体的实训云服务

由于区域发展不平衡,目前高校实验资源存在不同程度紧缺,各科研高校通过建立虚拟仿真实训平台,大大缓解高校实验资源不足状况。结合实训资源呈现分布广、种类多、结构异构、管理自治和动态组合等特征,本文设计基于本体语义的实训云服务体系结构,利用本体技术和Protégé实现实训云语义描述,采用Web Services技术实现实训资源匹配和定位。本文设计的实训云提高了开放式在线实训平台的开发与利用。     

基于云计算的开放性教学资源平台建设研究

针对当前高等教育信息化资源平台建设零散分布、重复投资等突出问题,提出了基于云计算的开放性教学资源平台建设方案。以期建立一个基于云计算的集中管理、分散存储的资源开发、管理、应用系统平台,形成高等教育信息化资源共建共享的机制。首先分析了基于云计算的开放性教学资源平台建设的可行性,然后提出了基于云计算的开放性教学资源平台的设计思想、系统设计、系统架构、资源库建设内容,并对主要应用功能进行了概述,有助于推进基于云计算的高校信息化资源平台建设进程。     

一种基于Linux容器技术的大规模遥感数据云服务平台

遥感数据云服务平台是基于云计算技术,整合大规模遥感数据的存储资源和计算资源,实现资源共享和按需使用的服务模式的地理信息处理服务平台。我们基于分布式存储技术实现遥感数据的高效存储、Linux 容器技术实现快速部署和资源隔离、ownCloud 私有云技术实现高效共享和 IPythonnotebook 交互式技术实现方便易用交互,设计了一种稳定、高效的地理信息云服务平台。用户可通过Web的方式方便的访问大规模遥感数据,并利用云主机的计算、存储资源对所需的遥感数据进行分析和处理。     

Visual creation of inhabited 3D environments

The creation of virtual reality applications and 3D environments is a complex task that requires good programming skills and expertise in computer graphics and many other disciplines. The complexity increases when we want to include complex entities such as virtual characters and animate them. In this paper we present a system that assists in the tasks of setting up a 3D scene and configuring several parameters affecting the behavior of virtual entities like objects and autonomous virtual humans. Our application is based on a visual programming paradigm, supported by a semantic representation, an ontology for virtual environments. The ontology allows us to store and organize the components of a 3D scene, together with the knowledge associated with them. It is also used to expose functionalities in the given 3D engine. Based on a formal representation of its components, the proposed architecture provides a scalable VR system. Using this system, non-experts can set up interactive scenarios with minimum effort; no programming skills or advanced knowledge is required.     

基于云计算的数据安全风险及防范策略探讨

云计算依托计算机网络系统,目前已经成为人们生活的重要部分,随着网络化、虚拟化生活的加速发展,诸如Google、Microsoft、Apple、Amazon、IBM等互联网IT和手机、网络运营商巨头开始重新定位企业发展的战略核心.云计算作为IT商业计算模型,它将计算任务分布在各种类型的广域网络和局域网络组成计算机网络系统,使用户能够借助网络按需获取计算力、存储空间和信息服务.云计算的用户通过PC、手机以及其他终端连接到网络使用云资源;随着云计算的广泛应用,云计算的环境安全环境、数据安全成为突出问题,如何保障云计算的安全成为当前急需解决的问题.本文介绍了云计算相关概念,以及对云计算数据安全风险进行分析,并提出了防范策略.     

云计算环境安全综述

伴随云计算技术的飞速发展,其所面临的安全问题日益凸显,在工业界和学术界引起了广泛的关注.传统的云基础架构中存在较高安全风险,攻击者对虚拟机的非法入侵破坏了云服务或资源的可用性,不可信的云存储环境增大了用户共享、检索私有数据的难度,各类外包计算和云应用需求带来了隐私泄露的风险.该文从云计算环境下安全与隐私保护技术的角度出发,通过介绍云虚拟化安全、云数据安全以及云应用安全的相关研究进展,分析并对比典型方案的特点、适用范围及其在安全防御和隐私保护方面的不同效用,讨论已有工作的局限性,进而指出未来发展趋势和后续研究方向.     

基于包簇映射机制的实验平台建设及应用

从一般云平台和项目的实际需求出发,结合包簇架构,利用CloudStack开源云平台,设计一种基于包簇映射机制的实验平台。该实验平台采用分层的设计方法,包含硬件设施层、虚拟资源层、调度层、包簇中间件层以及用户应用层,将传统以虚拟机形式的资源申请转换成以需求包的形式进行申请,同时用户可以指定其需求包结构及每个包所需的物理资源。通过对云平台调度原理的分析,阐述如何将项目中涉及的包簇部署算法应用到该实验平台中,为后续改善项目的研究成果提供实验依据。最后选取云计算管理平台的6种重要的管理功能,通过对基于包簇机制的实验平台和CloudStack、OpenStack这2种云管理平台进行整体功能测试,结果表明本文的包簇实验平台提供了较全面的管理功能,具有一定的应用市场。