A cost-effective cloud computing framework for accelerating multimedia communication simulations

Multimedia communication research and development often requires computationally intensive simulations in order to develop and investigate the performance of new optimization algorithms. Depending on the simulations, they may require even a few days to test an adequate set of conditions due to the complexity of the algorithms. The traditional approach to speed up this type of relatively small simulations, which require several develop–simulate–reconfigure cycles, is indeed to run them in parallel on a few computers and leaving them idle when developing the technique for the next simulation cycle. This work proposes a new cost-effective framework based on cloud computing for accelerating the development process, in which resources are obtained on demand and paid only for their actual usage. Issues are addressed both analytically and practically running actual test cases, i.e., simulations of video communications on a packet lossy network, using a commercial cloud computing service. A software framework has also been developed to simplify the management of the virtual machines in the cloud. Results show that it is economically convenient to use the considered cloud computing service, especially in terms of reduced development time and costs, with respect to a solution using dedicated computers, when the development time is longer than one hour. If more development time is needed between simulations, the economic advantage progressively reduces as the computational complexity of the simulation increases.     

A network level channel abstraction for multimedia communication inreal-time networks

The design of communication protocols to support guaranteed real-time communication for distributed multimedia systems is examined. A network level abstraction called φ-channel that supports the requirements of real-time applications is proposed. A φ-channel represents a fractional, simplex, end-to-end communication channel between a source and a destination. The channel is characterized by a set of specific performance parameters associated with its traffic. The required performance characteristics of a φ-channel are specified in terms of the packet maximum end-to-end delay and the maximum number of packets that can be sent over that delay. The primary attribute supported by the φ-channel is the on-time reliability. Based on the specified parameters, the underlying delivery system verifies the feasibility of supporting such a channel. The performance of an accepted φ-channel is guaranteed under any conditions, barring hardware failures. The basic scheme that the model uses to verify the feasibility of accepting a φ-channel and the run-time support used to guarantee its performance are described. The results of a simulation experiment implementing the basic functionalities of the proposed scheme are also presented     

A multilevel computing architecture for embedded multimedia applications

We have designed a new architecture that simplifies integration of heterogeneous IP for multimedia and streaming applications. The multilevel computing architecture (MLCA) is a template architecture featuring multiple processing units. This template architecture for SOC systems uses superscalar techniques to exploit task-level parallelism among different processing units. It supports a natural programming model that relieves programmers from explicitly synchronizing tasks and communicating data. code transformations that improve application performance are easy to incorporate in compilers for this architecture.     

A multi-streaming SIMD multimedia computing engine

Current multimedia extensions provide a mechanism for general-purpose processors to meet the growing performance demand of multimedia applications. However, the computing performance of these extensions is often limited for the design conceptions of the single data stream. This paper presents an architecture called “multi-streaming SIMD” that enables current multimedia extensions to simultaneously manipulate multiple data streams. To efficiently and flexibly realize the proposed architecture, an operation cell is designed by fusing the logic gates and the storage cells together. Multiple operation cells then are connected to compose a register file with the ability of performing SIMD operations called “Multimedia Operation Storage Unit (MOSU)”. Further, many MOSUs are used to compose a multi-streaming SIMD computing engine that can simultaneously manipulate multiple data streams and exploit the subword parallelisms of the elements in each data stream. This paper also designs three instruction modes (global, coupling, and isolated modes) for programmers to dynamically configure the multi-streaming SIMD computing engine at the instruction level to manipulate different amounts of data streams. Simulation results show that when the multi-streaming SIMD architecture has four 4-register MOSUs, it provides a factor of 3.3×–5.5× performance enhancement for traditional MMX extensions on 12 multimedia kernels.     

An intelligent cloud-based data processing broker for mobile e-health multimedia applications

Mobile e-health applications provide users and healthcare practitioners with an insightful way to check users/patients’ status and monitor their daily calorie intake. Mobile e-health applications provide users and healthcare practitioners with an insightful way to check users/patients’ status and monitor their daily activities. This paper proposes a cloud-based mobile e-health calorie system that can classify food objects in the plate and further compute the overall calorie of each food object with high accuracy. The novelty in our system is that we are not only offloading heavy computational functions of the system to the cloud, but also employing an intelligent cloud-broker mechanism to strategically and efficiently utilize cloud instances to provide accurate and improved time response results. The broker system uses a dynamic cloud allocation mechanism that takes decisions on allocating and de-allocating cloud instances in real-time for ensuring the average response time stays within a predefined threshold. In this paper, we further demonstrate various scenarios to explain the workflow of the cloud components including: segmentation, deep learning, indexing food images, decision making algorithms, calorie computation, scheduling management as part of the proposed cloud broker model. The implementation results of our system showed that the proposed cloud broker results in a 45% gain in the overall time taken to process the images in the cloud. With the use of dynamic cloud allocation mechanism, we were able to reduce the average time consumption by 77.21% when 60 images were processed in parallel.     

A user-centric approach to dynamic adaptation of reusable communication services

The pervasiveness of electronic devices coupled with increasing resources within these devices has aided the explosion of available software services. While reusable software services have become more accessible and the cost of using these services has become cheaper, the increased number of services and access methods also increases the complexity for the user of these services, demanding too much attention from the user. On the other hand, automation can alleviate some of the complexity issues but at the expense of user control. We propose a balance between smart reusable integration, automation and user controllability, through a dynamically adaptive user-centric approach that utilizes goal-oriented intent modeling. This work leverages the convergence of services and providers for the user through reuse, autonomic adaptation of services to relieve the user’s of laborious and tedious tasks, while ensuring that the user’s end-goal remains central at all times. We applied our approach to the domains of collaborative communication as demonstration of the feasibility of the approach.     

A group interest-based collaborative filtering algorithm for multimedia information

This paper proposes a collaborative filtering algorithm based on user group interest. A novel co-clustering method (BalClust) and various weighted non-negative matrix factorization algorithms are used in the proposed method. The BalClust method is used to divide the raw rating matrix into clusters, which are smaller than the original matrix. Then, the balance factor is introduced to consider the user weight and the item-based CF (collaborative filtering). To predict the rating of the unknown items in the cluster, the non-negative matrix factorization algorithm was used. The proposed method achieves higher predicting accuracy and efficiency on low dimensional and homogeneous sub-matrices, and the method also reduces the computational complexity by combining the user and item-based CF. Based on the proposed method, this paper proposed an incremental learning method to ensure data accuracy and timeliness to overcome the problem brought by data updates. The experimental results show the proposed methods outperformed traditional CF algorithms, and the completion time is reduced.     

普适计算环境下的设备请求代理模型*

为了给普适计算环境提供一个统一的应用架构和模式,本文从普适计算研究现状出发,通过借鉴对象请求代理技术,提出了设备请求代理模型,建立了设备基件的远程映射管理和统一调度机制,有效降低了普适计算环境下应用程序的开发难度和兼容传统应用程序。     

Tacit guidance for collaborative multimedia learning

Collaborative multimedia learning is a scenario placing various demands on the learners that go beyond understanding complex issues and coordinating a learning discourse. On the one hand, individuals have to mentally interrelate multiple external representations in order to understand the learning material and the underlying concepts; on the other hand, during collaboration, learners have to use the differently coded information in order to exchange conceptual knowledge. In this paper, the development and experimental evaluation of a group awareness tool (collaborative integration tool) is presented that is intended to simultaneously support both individual and collaborative learning processes during dyadic collaborative multimedia learning. The tool was experimentally compared with an integration task that already proved to foster meaningful individual learning processes. The results suggest that providing group awareness can lead to better individual learning gains by reducing demanding processes and by tacitly guiding learner interactions.     

Retrieval scheduling for collaborative multimedia presentations

The single-system approach is no longer sufficient to handle the load on popular Internet servers, especially for those offering extensive multimedia content. Such services have to be replicated to enhance their availability, performance, and reliability. In a highly replicated and available environment, server selection is an important issue. In this paper, we propose an application-layer broker (ALB) for this purpose. ALB employs a content-based, client-centric approach to negotiate with the servers and to identify the best server for the requested objects. ALB aims to maximize client buffer utilization in order to efficiently handle dynamic user interactions such as skip, reverse presentation, go back in time. We also present details of a collaborative multimedia presentation platform that we have developed based on ALB.     

Cognitive computing for intelligent multimedia systems

Multimedia Tools and Applications -     

A computational economy for grid computing and its implementation in the Nimrod-G resource broker

Computational grids that couple geographically distributed resources such as PCs, workstations, clusters, and scientific instruments, have emerged as a next generation computing platform for solving large-scale problems in science, engineering, and commerce. However, application development, resource management, and scheduling in these environments continue to be a complex undertaking. In this article, we discuss our efforts in developing a resource management system for scheduling computations on resources distributed across the world with varying quality of service (QoS). Our service-oriented grid computing system called Nimrod-G manages all operations associated with remote execution including resource discovery, trading, scheduling based on economic principles and a user-defined QoS requirement. The Nimrod-G resource broker is implemented by leveraging existing technologies such as Globus, and provides new services that are essential for constructing industrial-strength grids. We present the results of experiments using the Nimrod-G resource broker for scheduling parametric computations on the World Wide Grid (WWG) resources that span five continents.     

On the performance of secure user-centric VoIP communication

Motivated by the increased Wi-Fi coverage in metropolitan areas and the emergence of user-centric wireless access schemes, we focus on the provision of secure, user-centric voice services and explore their potential performance-wise, by designing a VoIP communications scheme tailored to open-access wireless environments, but also with wider applicability, and experimenting with it to estimate its upper bounds on VoIP capacity, under constraints posed by user-centrism; operation at low-cost and on user-controlled equipment, minimal dependence on centralized entities, and tackling specific security challenges. We identify quality degradation factors and quantify their importance by simple analysis and experimentation, showing that typical user Wi-Fi equipment can sustain a satisfactory number of concurrent secure VoIP sessions with acceptable Quality of Experience and, at the same time, protection from malicious user activity can be offered to access providers, while a level of roaming privacy can be guaranteed.     

适于多种通信设备的多媒体通信终端软件

针对应急通信系统的需求,本文介绍了一种适用于多种通信设备的多媒体通信终端的软件实现方法.软件采用了面向对象的设计方法,根据通信设备和各种业务的特点,合理的界定了通信模块和各种业务模块之间的职能.在对通信模块接口进行合理抽象的基础上,软件实现了适用于以太网、网络电台和短波电台的通信模块.在通过不同的下层通信设备进行通信时,终端软件只需要选择不同的通信模块就能实现包括语音、视频、短信息、静态图像、电子白板和文件传输在内的多媒体通信.     

适于多种通信设备的多媒体通信终端软件

针对应急通信系统的需求,本文介绍了一种适用于多种通信设备的多媒体通信终端的软件实现方法。软件采用了面向对象的设计方法,根据通信设备和各种业务的特点,合理的界定了通信模块和各种业务模块之间的职能。在对通信模块接口进行合理抽象的基础上,软件实现了适用于以太网、网络电台和短波电台的通信模块。在通过不同的下层通信设备进行通信时,终端软件只需要选择不同的通信模块就能实现包括语音、视频、短信息、静态图像、电子白板和文件传输在内的多媒体通信。