An online context-aware mechanism for computation offloading in ubiquitous and mobile cloud environments

The Journal of Supercomputing - In ubiquitous environments today, there are numerous sensors that generate a large amount of data. The results of processing this massive data can be applied through...     

面向云-端融合的移动互联网应用运行平台

与传统的互联网应用相比,移动互联网应用尽管也运行于Web技术栈之上,但移动设备的便携性和多样性,带来了客户端设备计算能力相对有限、数据存储随需而变、显示屏幕大小不一、本地应用与Web应用和服务难以交互等技术挑战.为此,本文设计实现了一种面向云-端融合的移动互联网应用运行平台.首先,提出一种符合移动互联网应用体系结构的构件模型,将客户端应用划分为数据、计算、界面和服务四个部分;其次,设计了一种实现云-端资源融合的构件运行框架,支持应用数据的按需存储、计算任务的云-端迁移、以及用户界面的动态切分;再次,设计了一种实现云-端服务融合的组装框架,支持客户端本地应用和传统Web应用的服务封装、和基于总线的服务即时组装;最后,基于Chrome浏览器实现了平台原型,支持基于HTML5和JavaScript的移动互联网应用,通过多个Web应用基准测试集和热点应用的实验,验证了平台的有效性和可行性.     

Mining multilevel and location-aware service patterns in mobile web environments

In this correspondence, we address the issue of efficiently mining multilevel and location-aware associated service patterns in a mobile web environment. In terms of multilevel concept, we consider the complex problem that locations and services are of hierarchical structures. We propose a new data mining method named two-dimensional multilevel (2-DML) association rules mining, which can efficiently discover the associated service request patterns by taking into account the multilevel properties of locations and services. The discovered patterns can be effectively utilized in real applications like location-based and personalized services. To the best of our knowledge, this is the first work addressing this research issue. Some variations of the 2-DML method with different properties in terms of execution efficiency and memory efficiency were also developed. Through empirical evaluation, the proposed methods are shown to deliver good performance in terms of efficiency and scalability under various system conditions.     

Efficient data integrity auditing for storage security in mobile health cloud

Cloud storage services can enable data owners to eliminate the need for the initial investment of expensive infrastructure setup and also minimize development and maintenance costs. Outsourcing the health data to e-health cloud storage server is very beneficial. Nonetheless, storing the health data on cloud servers also brings serious security challenges. In this paper, we propose a highly efficient data integrity auditing scheme for cloud storage for mobile health applications. The authentication tag for each data block generated by biosensor nodes is minimal in our scheme due to the use of hash operation. Moreover, in data integrity checking phase, message-locked encryption scheme is utilized to encrypt and transport the auditing information of the checked data blocks, which significantly reduces the required amount of calculation and communication resources. Compared with the conventional third party auditing schemes, the presented scheme speeds up the tag generation and tag checking process by more than one thousand times.     

Dynamic cloud resource management for efficient media applications in mobile computing environments

Single-instruction-set architecture (Single-ISA) heterogeneous multi-core processors (HMP) are superior to Symmetric Multi-core processors in performance per watt. They are popular in many aspects of the Internet of Things, including mobile multimedia cloud computing platforms. One Single-ISA HMP integrates both fast out-of-order cores and slow simpler cores, while all cores are sharing the same ISA. The quality of service (QoS) is most important for virtual machine (VM) resource management in multimedia mobile computing, particularly in Single-ISA heterogeneous multi-core cloud computing platforms. Therefore, in this paper, we propose a dynamic cloud resource management (DCRM) policy to improve the QoS in multimedia mobile computing. DCRM dynamically and optimally partitions shared resources according to service or application requirements. Moreover, DCRM combines resource-aware VM allocation to maximize the effectiveness of the heterogeneous multi-core cloud platform. The basic idea for this performance improvement is to balance the shared resource allocations with these resources requirements. The experimental results show that DCRM behaves better in both response time and QoS, thus proving that DCRM is good at shared resource management in mobile media cloud computing.     

A survey on decision making for task migration in mobile cloud environments

The key idea of MCC is using powerful back-end computing nodes to enhance capabilities of small mobile devices and provide better user experiences. An effective and widely used approach to realize this is task migrations. Decision making is an important aspect of migrations which affects the feasibility and effectiveness of task migrations. There have been a number of research efforts to MCC which help make decisions for task migrations. In this paper, we present a comprehensive survey on decision making for task migrations in MCC, including decision factors and algorithms. We observe that there are still some challenges such as comprehensive context awareness, unified migration standards, large-scale experiments, more involvement of latest achievements from artificial intelligence, and flexible decision-making mechanisms. The paper highlights these issues and challenges to attract more efforts to work on MCC.     

Energy-efficiency enhanced virtual machine scheduling policy for mixed workloads in cloud environments

Virtualization technology is an effective approach to improving the energy-efficiency in cloud platforms; however, it also introduces many energy-efficiency losses especially when I/O virtualization is involved. In this paper, we present an energy-efficiency enhanced virtual machine (VM) scheduling policy, namely Share-Reclaiming with Collective I/O (SRC-I/O), with aiming at reducing the energy-efficiency losses caused by I/O virtualization. The proposed SRC-I/O scheduler allows VMs to reclaim extra CPU shares in certain conditions so as to increase CPU utilization. Meanwhile, it separates I/O-intensive VMs from CPU-intensive ones and schedules them in a collective manner, so as to reduce the context-switching cost when scheduling mixed workloads. Extensive experiments are conducted on various platforms to investigate the performance of the proposed scheduler. The results indicate that when the system is in presence of mixed workloads, SRC-I/O scheduler outperforms many existing VM schedulers in terms of energy-efficiency and I/O responsiveness.     

Leveraging bandwidth improvements to web servers through enhanced network interfaces

Markets nowadays demand applications that require high communication throughputs to reach their adequate levels of performance. Although the bandwidth of the network links has increased allowing multiple gigabits per second, taking advantage of these links accounts for a high communication overhead, and thus a lot of processor cycles are used for communication tasks, diminishing the processor cycles that remain available for the application. In this paper, we evaluate the performance in web applications of a network interface that as it is distributed among the processors currently available in the node takes advantage of both the hardware (multiprocessor nodes and multicore architectures, as well as programmable network interface cards) and software elements present in the system, thus improving not only the effective communication throughputs and latencies, but also the capacity of the nodes to satisfy the requirements of the applications. Here, the usefulness of this distributed network interface to improve the performance of either static or dynamic web servers is shown. The ubiquity and the different computation/communication rates that can be found in web applications make the analysis of web servers interesting, as it could provide relevant conclusions about the efficiency of the different approaches to the design of high-performance network interfaces.     

Dynamic replication of web contents

The phenomenal growth of the World Wide Web has brought huge increase in the traffic to the popular web sites. Long delays and denial of service experienced by the end-users, especially during the peak hours, continues to be the common problem while accessing popular sites. Replicating some of the objects at multiple sites in a distributed web-server environment is one of the possible solutions to improve the response time/latency. The decision of what and where to replicate requires solving a constraint optimization problem, which is NP-complete in general. In this paper, we consider the problem of placing copies of objects in a distributed web server system to minimize the cost of serving read and write requests when the web servers have limited storage capacity. We formulate the problem as a 0-1 optimization problem and present a polynomial time greedy algorithm with backtracking to dynamically replicate objects at the appropriate sites to minimize a cost function. To reduce the solution search space, we present necessary conditions for a site to have a replica of an object in order to minimize the cost function. We present simulation results for a variety of problems to illustrate the accuracy and efficiency of the proposed algorithms and compare them with those of some well-known algorithms. The simulation results demonstrate the superiority of the proposed algorithms.     

An autonomic approach for P2P/cloud collaborative environments

The rise of Cloud Computing has progressively dimmed the interest in volunteer and peer-to-peer computing, in general. However, efficient and cost-effective large scale distributed collaborative environments cannot be achieved leveraging upon the Cloud alone. In this paper, we propose a novel hybrid P2P/cloud approach where components and protocols are autonomically configured according to specific target goals, such as cost-effectiveness, reliability and availability. The proposed approach is based on the Networked Autonomic Machine (NAM) framework, which allows distributed system designers to include different kinds of cost and performance constraints. As an example, we show how the NAM-based approach can be used to design collaborative storage systems, enabling the definition of an autonomic policy to decide, according to cost minimization and data availability goals, how to part data chunks among peer nodes and Cloud, based on the local perception of the P2P network.     

Secure and efficient image retrieval through invariant features selection in insecure cloud environments

Neural Computing and Applications - Advances in computer vision technologies lead to a renewed focus on content-based image retrieval (CBIR) in computer multimedia content analysis applications....     

An adaptive model-free resource and power management approach for multi-tier cloud environments

With the development of cloud environments serving as a unified infrastructure, the resource management and energy consumption issues become more important in the operations of such systems. In this paper, we investigate adaptive model-free approaches for resource allocation and energy management under time-varying workloads and heterogeneous multi-tier applications. Specifically, we make use of measurable metrics, including throughput, rejection amount, queuing state, and so on, to design resource adjustment schemes and to make control decisions adaptively. The ultimate objective is to guarantee the summarized revenue of the resource provider while saving energy and operational costs. To validate the effectiveness, performance evaluation experiments are performed in a simulated environment, with realistic workloads considered. Results show that with the combination of long-term adaptation and short-term adaptation, the fluctuation of unpredictable workloads can be captured, and thus the total revenue can be preserved while balancing the power consumption as needed. Furthermore, the proposed approach can achieve better effect and efficiency than the model-based approaches in dealing with real-world workloads.     

An enhanced authenticated key agreement protocol for wireless mobile communication

With the rapid progress of wireless mobile communication, the authenticated key agreement protocol has attracted an increasing amount of attention. However, due to the limitations of bandwidth and storage of the mobile devices, most of the existing authenticated key agreement protocols are not suitable for wireless mobile communication. Quite recently, Sui et al. have presented an efficient authenticated key agreement protocol based on elliptic curves cryptography and included their protocol in 3GPP2 specifications to improve the security of A-Key distribution. However, in this paper, we show that Sui et al.'s protocol can't resist the off-line password guessing attack, and therefore present an enhanced authenticated key agreement protocol. At the same time, we also consider including our enhanced protocol in 3GPP2 specifications.     

An intelligent RFID-enabled authentication scheme for healthcare applications in vehicular mobile cloud

Recently, vehicular cloud computing (VCC) has emerged as the one of the fast growing technologies with an aim to provide uninterrupted services to the moving clients even on-the-fly. One of the services provided by VCC is the mobile healthcare in which patient can be provided diagonosis from anywhere during their mobility. This paper proposes an intelligent RFID-enabled authentication scheme for healthcare applications in VCC environment. In the proposed scheme, a Petri Nets-based authentication model is used for authentication of tags, and readers. Both server, and tag authentications are protected by strong elliptical curve cryptography (ECC)-based key generation mechanism. The proposed scheme is found to be secure with respect to mutual authentication of servers and tags, replay attack, tracking attack, users anonymity, eavesdropping, and cloning with forward secrecy. To evaluate the effectiveness of the proposed scheme, it is evaluated with respect to the overhead generated, computation complexity, and % service delivery, where its performance is found better than the case where it is not applied.     

Understanding user perceptions of World-wide web environments

Abstract The purpose of this study was to develop and test a conceptual model of individual perceptions of Web technology as a use and training tool. The model presents a perspective of users' attitudes toward Web environments. This model integrates the Technical Acceptance Model, Social Cognitive Theory, individual attitudes, motivation and self-efficacy perspectives to develop a new aspect of users' perceptions toward Web technology acceptance and use. The study provides some evidence that the conceptual model helps the understanding of user perceptions to Web environments. In addition, training and educational programmes on computers may foster a positive feeling towards the Web. Furthermore, the more individuals have self-efficacy towards Web technology, the more individuals have motivation to use the Web.     

An empirical study of the cross-channel effects between web and mobile shopping channels

With the increasing popularity of mobile applications, increasingly more e-commerce websites are providing mobile shopping services that enable their consumers to access their products and services through an additional mobile channel. The question arises here as to whether the new channel brings new sales or merely shifts consumers from the web to the mobile channel. Using the 2½-year transaction data obtained from an e-commerce company that expanded its web service onto a mobile platform, we investigated the impact of the newly introduced mobile channel on the sales of the incumbent web channel, and whether it could stimulate new consumption from consumers. Our empirical results indicate that after the adoption of the mobile channel, the purchases on the web channel were slightly cannibalized; however, the consumers’ purchases increased overall, suggesting that the positive synergy effect of the new channel overrode the negative cannibalization effect. Our investigation contributes to multichannel e-commerce literature by empirically testing the cross-channel effects of a new mobile channel and also providing insights for e-retailers interested in introducing a new mobile channel.     

An enhanced genetic algorithm for constrained knapsack problems in dynamic environments

Natural Computing - In this paper, an enhanced genetic algorithm (ERGA), based on memory updating and environment reaction schemes, has been proposed to solve constrained knapsack problems in...