Context Aware Service Oriented Computing in Mobile Ad Hoc Networks

These days we witness a major shift towards small, mobile devices, capable of wireless communication. Their communication capabilities enable them to form mobile ad hoc networks and share resources and capabilities. Service Oriented Computing (SOC) is a new emerging paradigm for distributed computing that has evolved from object-oriented and component-oriented computing to enable applications distributed within and across organizational boundaries. Services are autonomous computational elements that can be described, published, discovered, and orchestrated for the purpose of developing applications. The application of the SOC model to mobile devices provides a loosely coupled model for distributed processing in a resource-poor and highly dynamic environment. Cooperation in a mobile ad hoc environment depends on the fundamental capability of hosts to communicate with each other. Peer-to-peer interactions among hosts within communication range allow such interactions but limit the scope of interactions to a local region. Routing algorithms for mobile ad hoc networks extend the scope of interactions to cover all hosts transitively connected over multi-hop routes. Additional contextual information, e.g., knowledge about the movement of hosts in physical space, can help extend the boundaries of interactions beyond the limits of an island of connectivity. To help separate concerns specific to different layers, a coordination model between the routing layer and the SOC layer provides abstractions that mask the details characteristic to the network layer from the distributed computing semantics above. This thesis explores some of the opportunities and challenges raised by applying the SOC paradigm to mobile computing in ad hoc networks. It investigates the implications of disconnections on service advertising and discovery mechanisms. It addresses issues related to code migration in addition to physical host movement. It also investigates some of the security concerns in ad hoc networking service provision. It presents a novel routing algorithm for mobile ad hoc networks and a novel coordination model that addresses space and time explicitly

Architecture and implementation of online communities

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references.by Philip Greenspun.Ph.D

Untangling the Web: A Guide To Internet Research

[Excerpt] Untangling the Web for 2007 is the twelfth edition of a book that started as a small handout. After more than a decade of researching, reading about, using, and trying to understand the Internet, I have come to accept that it is indeed a Sisyphean task. Sometimes I feel that all I can do is to push the rock up to the top of that virtual hill, then stand back and watch as it rolls down again. The Internet—in all its glory of information and misinformation—is for all practical purposes limitless, which of course means we can never know it all, see it all, understand it all, or even imagine all it is and will be. The more we know about the Internet, the more acute is our awareness of what we do not know. The Internet emphasizes the depth of our ignorance because our knowledge can only be finite, while our ignorance must necessarily be infinite. My hope is that Untangling the Web will add to our knowledge of the Internet and the world while recognizing that the rock will always roll back down the hill at the end of the day

Changing the way the world thinks about computer security.

Small changes in an established system can result in larger changes in the overall system (e.g. network effects, émergence, criticality, broken Windows theory). However, in an immature discipline, such as computer security, such changes can be difficult to envision and even more difficult to amplement, as the immature discipline is likely to lack the scientific framework that would allow for the introduction of even minute changes. (Cairns, P. and Thimbleby, H, 2003) describe three of the signs of an immature discipline as postulated by (Kuhn, 1970): a. squabbles over what are legitimate tools for research b. disagreement over which phenomenon are legitimate to study, and c. inability to scope the domain of study. The research presented in this document demonstrates how the computer security field, at the time this research began, was the embodiment of thèse characteristics. It presents a cohesive analysis of the intentional introduction of a séries of small changes chosen to aid in maturation of the discipline. Summarily, it builds upon existing theory, exploring the combined effect of coordinated and strategie changes in an immature system and establishing a scientific framework by which the impact of the changes can be quantified. By critically examining the nature of the computer security system overall, this work establishes the need for both increased scientific rigor, and a multidisciplinary approach to the global computer security problem. In order for these changes to take place, many common assumptions related to computer security had to be questioned. However, as the discipline was immature, and controlled by relatively few entities, questioning the status quo was not without difficulties. However, in order for the discipline to mature, more feedback into the overall computer security (and in particular, the computer malware/virus) system was needed, requiring a shift from a mostly closed system to one that was forced to undergo greater scrutiny from various other communities. The input from these communities resulted in long-term changes and increased maturation of the system. Figure 1 illustrates the specific areas in which the research presented herein addressed these needs, provides an overview of the research context, and outlines the specific impact of the research, specifically the development of new and significant scientific paradigms within the discipline

Changing the way the world thinks about computer security

Small changes in an established system can result in larger changes in the overall system (e.g. network effects, émergence, criticality, broken Windows theory). However, in an immature discipline, such as computer security, such changes can be difficult to envision and even more difficult to amplement, as the immature discipline is likely to lack the scientific framework that would allow for the introduction of even minute changes. (Cairns, P. and Thimbleby, H, 2003) describe three of the signs of an immature discipline as postulated by (Kuhn, 1970): a. squabbles over what are legitimate tools for research b. disagreement over which phenomenon are legitimate to study, and c. inability to scope the domain of study. The research presented in this document demonstrates how the computer security field, at the time this research began, was the embodiment of thèse characteristics. It presents a cohesive analysis of the intentional introduction of a séries of small changes chosen to aid in maturation of the discipline. Summarily, it builds upon existing theory, exploring the combined effect of coordinated and strategie changes in an immature system and establishing a scientific framework by which the impact of the changes can be quantified. By critically examining the nature of the computer security system overall, this work establishes the need for both increased scientific rigor, and a multidisciplinary approach to the global computer security problem. In order for these changes to take place, many common assumptions related to computer security had to be questioned. However, as the discipline was immature, and controlled by relatively few entities, questioning the status quo was not without difficulties. However, in order for the discipline to mature, more feedback into the overall computer security (and in particular, the computer malware/virus) system was needed, requiring a shift from a mostly closed system to one that was forced to undergo greater scrutiny from various other communities. The input from these communities resulted in long-term changes and increased maturation of the system. Figure 1 illustrates the specific areas in which the research presented herein addressed these needs, provides an overview of the research context, and outlines the specific impact of the research, specifically the development of new and significant scientific paradigms within the discipline.EThOS - Electronic Theses Online ServiceGBUnited Kingdo