Mining frequent itemsets in distorted databases with granula computing

Data perturbation is a popular method to achieve privacy-preserving data mining. However, distorted databases bring enormous overheads to mining algorithms as compared to original databases. In this paper, we present the GrC-FIM algorithm to address the efficiency problem in mining frequent itemsets from distorted databases. Two measures are introduced to overcome the weakness in existing work: firstly, the concept of independent granule is introduced, and granule inference is used to distinguish between non-independent itemsets and independent itemsets. We further prove that the support counts of non-independent itemsets can be directly derived from subitemsets, so that the error-prone reconstruction process can be avoided. This could improve the efficiency of the algorithm, and bring more accurate results; secondly, through the granular-bitmap representation, the support counts can be calculated in an efficient way. The empirical results on representative synthetic and real-world databases indicate that the proposed GrC-FIM algorithm outperforms the popular EMASK algorithm in both the efficiency and the support count reconstruction accuracy.

Computing the numerical scale of the linguistic term set for the 2-tuple fuzzy linguistic representation model

When using linguistic approaches to solve decision problems, we need the techniques for computing with words (CW). Together with the 2-tuple fuzzy linguistic representation models (i.e., the Herrera and Mart´ınez model and the Wang and Hao model), some computational techniques for CW are also developed. In this paper, we define the concept of numerical scale and extend the 2-tuple fuzzy linguistic representation models under the numerical scale.We find that the key of computational techniques
based on linguistic 2-tuples is to set suitable numerical scale with
the purpose of making transformations between linguistic 2-tuples
and numerical values. By defining the concept of the transitive
calibration matrix and its consistent index, this paper develops an optimization model to compute the numerical scale of the linguistic term set. The desired properties of the optimization model are also presented. Furthermore, we discuss how to construct the transitive calibration matrix for decision problems using linguistic preference relations and analyze the linkage between the consistent index of the transitive calibration matrix and one of the linguistic preference relations. The results in this paper are pretty helpful to complete the fuzzy 2-tuple representation models for CW.

Parallel computing on clusters and enterprise grids : practice and experience

We assert that companies can make more money and research institutions can improve their performance if inexpensive clusters and enterprise grids are exploited. In this paper, we have demonstrated that our claim is valid by showing the study of how programming environments, tools and middleware could be used for the execution of parallel and sequential applications, multiple parallel applications executing simultaneously on a non-dedicated cluster, and parallel applications on an enterprise grid and that the execution performance was improved. For this purpose an execution environment, and parallel and sequential benchmark applications selected for, and used in, the experiments were characterised.

Energy-efficient management of data center resources for cloud computing : a vision, architectural elements, and open challenges

Cloud computing is offering utility-oriented IT services to users worldwide. Based on a pay-as-you-go model, it enables hosting of pervasive applications from consumer, scientific, and business domains. However, data centers hosting Cloud applications consume huge amounts of energy, contributing to high operational costs and carbon footprints to the environment. Therefore, we need Green Cloud computing solutions that can not only save energy for the environment but also reduce operational costs. This paper presents vision, challenges, and architectural elements for energy-efficient management of Cloud computing environments. We focus on the development of dynamic resource provisioning and allocation algorithms that consider the synergy between various data center infrastructures (i.e., the hardware, power units, cooling and software), and holistically work to boost data center energy efficiency and performance. In particular, this paper proposes (a) architectural principles for energy-efficient management of Clouds; (b) energy-efficient resource allocation policies and scheduling algorithms considering quality-of-service expectations, and devices power usage characteristics; and (c) a novel software technology for energy-efficient management of Clouds. We have validated our approach by conducting a set of rigorous performance evaluation study using the CloudSim toolkit. The results demonstrate that Cloud computing model has immense potential as it offers significant performance gains as regards to response time and cost saving under dynamic workload scenarios.

Above the trust and security in cloud computing : a notion towards innovation

While the nascent Cloud Computing paradigm supported by virtualization has the upward new notion of edges, it lacks proper security and trust mechanisms. Edges are like on demand scalability and infinite resource provisioning as per the `pay-as-you-go' manner in favour of a single information owner (abbreviated as INO from now onwards) to multiple corporate INOs. While outsourcing information to a cloud storage controlled by a cloud service provider (abbreviated as CSP from now onwards) relives an information owner of tackling instantaneous oversight and management needs, a significant issue of retaining the control of that information to the information owner still needs to be solved. This paper perspicaciously delves into the facts of the Cloud Computing security issues and aims to explore and establish a secure channel for the INO to communicate with the CSP while maintaining trust and confidentiality. The objective of the paper is served by analyzing different protocols and proposing the one in commensurate with the requirement of the security property like information or data confidentiality along the line of security in Cloud Computing Environment (CCE). To the best of our knowledge, we are the first to derive a secure protocol by successively eliminating the dangling pitfalls that remain dormant and thereby hamper confidentiality and integrity of information that is worth exchanging between the INO and the CSP. Besides, conceptually, our derived protocol is compared with the SSL from the perspectives of work flow related activities along the line of secure trusted path for information confidentiality.

Conceptualizing social influence in the ubiquitous computing era : technology adoption and use in multiple use contexts

Ubiquitous and mobile computing has increased the level of social connectedness. In an era where technology has permeated into spaces of work, play and socializing, social influence has become an important consideration. The operationalization of the social influence construct in the technology adoption and use literature often assumes singular technology use contexts and purposes. We question whether social influence, as operationalized in IS, is reflective of the utilitarian, hedonic and social environment that many individuals operate in. We propose a framework to consider social influence more inclusively, drawing on differences in referent power and levels of expertise. We outline our research approach within the demographic segment of young working professionals. Research in this area is necessary to improve theoretical explanations of adoptive behavior of these technologies. We hope to contribute by suggesting a richer, more encompassing operationalization of the social influence construct for future IS research.

Conceptualizing user satisfaction in the ubiquitous computing era

In this research-in-progress paper we argue that technology in the ubiquitous computing era offers experiences to users that extend well beyond the functional, practical applications offered in the world of work. In this era a realm of engagement is opening up to the individual that transcends the utilitarian, to encompass hedonic and social existence. Our central argument, therefore, is that user satisfaction is a notion which must extend to encompass rich, holistic human experience involving complex and fleeting interactions, driven by highly personal circumstances. We argue that the expectations, requirements and value perceptions of individuals in this dynamic context may only be anticipated and understood if situational factors (such as location, time, context, history-of-use) and quality of life factors (such as life stage, mobility, health, income, background, education) are taken into account. We identify the fundamental differences in key characteristics of user satisfaction between the traditional and ubiquitous computing environments and provide details about our own research approach, in which we are exploring ubiquitous content provision from the perspective of content providers.

Contextual influences on user satisfaction with mobile computing : findings from two healthcare organizations

Mobile information technologies (IT) are transforming individual work practices and organizations. These devices are extending not only the boundaries of the ‘office’ in space and time, but also the social context within which use occurs. In this paper, we investigate how extra-organizational influences can impact user satisfaction with mobile systems. The findings from our longitudinal study highlight the interrelatedness of different use contexts and their importance in perceptions of user satisfaction. The data indicate that varying social contexts of individual use (individual as employee, as professional, as private user, and as member of society) result in different social influences that affect the individual’s perceptions of user satisfaction with the mobile technology. While existing theories explain user satisfaction with IT within the organizational context, our findings suggest that future studies of mobile IT in organizations should accommodate such extra-organizational contextual influences.

Toward higher level abstractions for cloud computing

The general idea of cloud computing is offering computational resources as scalable, on demand services accessible over the internet. However, this new realisation of on demand computing is hindered by the amount of user involvement. Currently, high level abstractions in cloud computing only exist in the form of services. In particular, there is no effective means to publish, discover and finally use required services in clouds. In response, we propose a user level abstraction on top of already available cloud abstraction layers, present its concept using the resources via web services (RVWS) framework and demonstrate its feasibility by simplifying the exposure and use of clusters, a commonly used resource in cloud computing.

Special section : trusted computing

Security and privacy have been the major concern when people build computer networks and systems. Any computer network or system must be trustworthy to avoid the risk of losing control and retain confidence that it will not fail [1] Jun Ho Huh, John Lyle, Cornelius Namiluko and Andrew Martin, Managing application whitelists in trusted distributed systems. Future Generation Computer Systems,  27 2 (2011), pp. 211–226. [1]. Trust is the key factor to enable dynamic interaction and cooperation of various users, systems and services [2]. Trusted Computing aims at making computer networks, systems, and services available, predictable, traceable, controllable, assessable, sustainable, dependable, and security/privacy protectable. This special section focuses on the issues related to trusted computing, such as trusted computing models and specifications, trusted reliable and dependable systems, trustworthy services and applications, and trust standards and protocols.

Establishing trust in hybrid cloud computing environments

Establishing trust for resource sharing and collaboration has become an important issue in distributed computing environment. In this paper, we investigate the problem of establishing trust in hybrid cloud computing environments. As the scope of federated cloud computing enlarges to ubiquitous and pervasive computing, there will be a need to assess and maintain the trustworthiness of the cloud computing entities. We present a fully distributed framework that enable trust-based cloud customer and cloud service provider interactions. The framework aids a service consumer in assigning an appropriate weight to the feedback of different raters regarding a prospective service provider. Based on the framework, we developed a mechanism for controlling falsified feedback ratings from iteratively exerting trust level contamination due to falsified feedback ratings. The experimental analysis shows that the proposed framework successfully dilutes the effects of falsified feedback ratings, thereby facilitating accurate and fair assessment of the service reputations.