127,018 research outputs found

    Trusted Computing and Secure Virtualization in Cloud Computing

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    Large-scale deployment and use of cloud computing in industry is accompanied and in the same time hampered by concerns regarding protection of data handled by cloud computing providers. One of the consequences of moving data processing and storage off company premises is that organizations have less control over their infrastructure. As a result, cloud service (CS) clients must trust that the CS provider is able to protect their data and infrastructure from both external and internal attacks. Currently however, such trust can only rely on organizational processes declared by the CS provider and can not be remotely verified and validated by an external party. Enabling the CS client to verify the integrity of the host where the virtual machine instance will run, as well as to ensure that the virtual machine image has not been tampered with, are some steps towards building trust in the CS provider. Having the tools to perform such verifications prior to the launch of the VM instance allows the CS clients to decide in runtime whether certain data should be stored- or calculations should be made on the VM instance offered by the CS provider. This thesis combines three components -- trusted computing, virtualization technology and cloud computing platforms -- to address issues of trust and security in public cloud computing environments. Of the three components, virtualization technology has had the longest evolution and is a cornerstone for the realization of cloud computing. Trusted computing is a recent industry initiative that aims to implement the root of trust in a hardware component, the trusted platform module. The initiative has been formalized in a set of specifications and is currently at version 1.2. Cloud computing platforms pool virtualized computing, storage and network resources in order to serve a large number of customers customers that use a multi-tenant multiplexing model to offer on-demand self-service over broad network. Open source cloud computing platforms are, similar to trusted computing, a fairly recent technology in active development. The issue of trust in public cloud environments is addressed by examining the state of the art within cloud computing security and subsequently addressing the issues of establishing trust in the launch of a generic virtual machine in a public cloud environment. As a result, the thesis proposes a trusted launch protocol that allows CS clients to verify and ensure the integrity of the VM instance at launch time, as well as the integrity of the host where the VM instance is launched. The protocol relies on the use of Trusted Platform Module (TPM) for key generation and data protection. The TPM also plays an essential part in the integrity attestation of the VM instance host. Along with a theoretical, platform-agnostic protocol, the thesis also describes a detailed implementation design of the protocol using the OpenStack cloud computing platform. In order the verify the implementability of the proposed protocol, a prototype implementation has built using a distributed deployment of OpenStack. While the protocol covers only the trusted launch procedure using generic virtual machine images, it presents a step aimed to contribute towards the creation of a secure and trusted public cloud computing environment

    Security and VO management capabilities in a large-scale Grid operating system

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    This paper presents a number of security and VO management capabilities in a large-scale distributed Grid operating system. The capabilities formed the basis of the design and implementation of a number of security and VO management services in the system. The main aim of the paper is to provide some idea of the various functionality cases that need to be considered when designing similar large-scale systems in the future

    Project Quality of Offshore Virtual Teams Engaged in Software Requirements Analysis: An Exploratory Comparative Study

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    The off-shore software development companies in countries such as India use a global delivery model in which initial requirement analysis phase of software projects get executed at client locations to leverage frequent and deep interaction between user and developer teams. Subsequent phases such as design, coding and testing are completed at off-shore locations. Emerging trends indicate an increasing interest in off-shoring even requirements analysis phase using computer mediated communication. We conducted an exploratory research study involving students from Management Development Institute (MDI), India and Marquette University (MU), USA to determine quality of such off-shored requirements analysis projects. Our findings suggest that project quality of teams engaged in pure off-shore mode is comparable to that of teams engaged in collocated mode. However, the effect of controls such as user project monitoring on the quality of off-shored projects needs to be studied further

    Cultural diversity and information and communication technology impacts on global virtual teams: An exploratory study.

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    Modern organizations face many significant challenges because of turbulent environments and a competitive global economy. Among these challenges are the use of information and communication technology (ICT), a multicultural workforce, and organizational designs that involve global virtual teams. Ad hoc teams create both opportunities and challenges for organizations and many organizations are trying to understand how the virtual environment affects team effectiveness. Our exploratory study focused on the effects of cultural diversity and ICT on team effectiveness. Interviews with 41 team members from nine countries employed by a Fortune 500 corporation were analyzed. Results suggested that cultural diversity had a positive influence on decision‐making and a negative influence on communication. ICT mitigated the negative impact on intercultural communication and supported the positive impact on decision making. Effective technologies for intercultural communication included e‐mail, teleconferencing combined with e‐Meetings, and team rooms. Cultural diversity influenced selection of the communication media

    Virtual Leadership: Required Competencies for Effective Leaders

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    There are countless books, articles, and resources available which attempt to identify the competencies and qualities of effective leaders. Traditionally, leaders have been at the center of a community, be it work, church, or social groups. In these communities, face-to-face meetings and close personal interaction have dominated the way leaders interact with their members. However, with the advent of the internet and the host of communication tools that followed, teams today are becoming increasingly dispersed and diverse. Studies are now being done to understand how leadership has or should evolve in order to meet the changing needs and demands of these new and different communities. Some argue that leadership in the virtual environment is simpler as fewer tools are available to virtual leaders. Others may argue that access to fewer tools makes virtual leadership more complex and challenging than traditional leadership. This paper will explore leadership in virtual settings and how it’s changing as more teams move away from traditional team environments. I’ll review the responsibilities and roles of virtual leaders in an effort to better highlight the core competencies needed in today’s virtual settings. I’ll also look at competencies required of global virtual leaders and I’ll address how these competencies can be cultivated to ensure leaders are more effective in leading teams in these new environments

    Grid Infrastructure for Domain Decomposition Methods in Computational ElectroMagnetics

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    The accurate and efficient solution of Maxwell's equation is the problem addressed by the scientific discipline called Computational ElectroMagnetics (CEM). Many macroscopic phenomena in a great number of fields are governed by this set of differential equations: electronic, geophysics, medical and biomedical technologies, virtual EM prototyping, besides the traditional antenna and propagation applications. Therefore, many efforts are focussed on the development of new and more efficient approach to solve Maxwell's equation. The interest in CEM applications is growing on. Several problems, hard to figure out few years ago, can now be easily addressed thanks to the reliability and flexibility of new technologies, together with the increased computational power. This technology evolution opens the possibility to address large and complex tasks. Many of these applications aim to simulate the electromagnetic behavior, for example in terms of input impedance and radiation pattern in antenna problems, or Radar Cross Section for scattering applications. Instead, problems, which solution requires high accuracy, need to implement full wave analysis techniques, e.g., virtual prototyping context, where the objective is to obtain reliable simulations in order to minimize measurement number, and as consequence their cost. Besides, other tasks require the analysis of complete structures (that include an high number of details) by directly simulating a CAD Model. This approach allows to relieve researcher of the burden of removing useless details, while maintaining the original complexity and taking into account all details. Unfortunately, this reduction implies: (a) high computational effort, due to the increased number of degrees of freedom, and (b) worsening of spectral properties of the linear system during complex analysis. The above considerations underline the needs to identify appropriate information technologies that ease solution achievement and fasten required elaborations. The authors analysis and expertise infer that Grid Computing techniques can be very useful to these purposes. Grids appear mainly in high performance computing environments. In this context, hundreds of off-the-shelf nodes are linked together and work in parallel to solve problems, that, previously, could be addressed sequentially or by using supercomputers. Grid Computing is a technique developed to elaborate enormous amounts of data and enables large-scale resource sharing to solve problem by exploiting distributed scenarios. The main advantage of Grid is due to parallel computing, indeed if a problem can be split in smaller tasks, that can be executed independently, its solution calculation fasten up considerably. To exploit this advantage, it is necessary to identify a technique able to split original electromagnetic task into a set of smaller subproblems. The Domain Decomposition (DD) technique, based on the block generation algorithm introduced in Matekovits et al. (2007) and Francavilla et al. (2011), perfectly addresses our requirements (see Section 3.4 for details). In this chapter, a Grid Computing infrastructure is presented. This architecture allows parallel block execution by distributing tasks to nodes that belong to the Grid. The set of nodes is composed by physical machines and virtualized ones. This feature enables great flexibility and increase available computational power. Furthermore, the presence of virtual nodes allows a full and efficient Grid usage, indeed the presented architecture can be used by different users that run different applications

    Acquiring and Applying Knowledge in Transnational Teams: The Roles of Cosmopolitans and Locals

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    This paper examines the roles of cosmopolitans and locals in transnational teams that work on knowledge-intensive projects. I propose that cosmopolitan and local team members can help their teams to acquire and apply knowledge more effectively, by bringing both internal and external knowledge to their teams and enabling them to more successfully transform this knowledge into improved project performance. Findings from a study of 96 project teams at an international development agency reveal that the roles of cosmopolitans and locals were complex and sometimes valuable, but cosmopolitans offered greater benefits than locals and too many of each could hurt. Implications for theory and research on international management, virtual teams, exploration and exploitation, and organizational knowledge are discussed
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