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A wireless mesh network (WMN) is a multihop wireless network consisting of a large number of wireless nodes of which some are called gateway nodes and connected with a wired network. Wireless mesh network have attracted much research attention recently due to its flexibility, low-cost and robustness, which facilitate its usability in many potential applications, including last-mile broadband Internet access, neighborhood gaming, Video-on-Demand (VoD), distributed file backup, video surveillance, etc. The broadcast nature, the lack of infrastructure as well as the flexible deployment nature of wireless mesh networks make it different from wired networks, therefore more attention in designing the wireless mesh network is needed to maintain a good performance of this promising technology. We, in this study, investigate the wireless mesh network design taking into consideration three design factors seeking an improvement in the network performance by reducing the interference influence in the network, improving the network reliability to satisfy more requests, and securing the network against malicious eavesdropping attacks. Our design is presented into three sub-problems; sub-problem (1), which seeks an interference-aware robust topology control scheme, sub-problem (2) which seeks a multipath routing scheme, and sub-problem (3) which seeks a secure key management scheme. Through simulations and comparisons with previous work, we show that our proposed solutions outperform previous schemes in providing a better network performance in terms of reducing the network interference, satisfying more number of requests and increasing the network resistance to malicious eavesdropping attacks.

Software reuse via component libraries suffers from the twin problems of code location and comprehension. The Intelligent Code Object Planner (ICOP) is a cognitively motivated system that facilitates code reuse by answering queries about how to produce an effect with the library. It can plan for effects which are not primitive with respect to the library by building a plan that incorporates multiple components. The primary subsystems of ICOP are a knowledge base which describes the ontology of the library, a natural language interface which translates user queries into a formal effect language (predicates), a planner which accepts the effect and produces a plan utilizing the library components, and an explanation generator which accepts the plan and produces example code illustrating the plan. ICOP is currently implemented in Prolog and supports a subset of the Windows 3.0 APL

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There has been an increased focus in recent years on the development of re-usable software, in the form of objects and software components. This increase, together with pressures from enterprises conducting transactions on the Web to support all business interactions on all scales, has encouraged research towards the development of easily reconfigurable and highly adaptable Web services. This work investigates the ability of Component-Based Software Development (CBSD) to produce such systems, and proposes a more manageable use of CBSD methodologies. Component-Driven Software Development (CDSD) is introduced to enable better component manageability. Current Web service technologies are also examined to determine their ability to support extensible Web services, and a dynamic Web service architecture is proposed. The work also describes the development of two proof-of-concept systems, DREW Chat and Hamilton Bank. DREW Chat and Hamilton Bank are implementations of Web services that support extension dynamically and at run-time. DREW Chat is implemented on the client side, where the user is given the ability to change the client as required. Hamilton Bank is a server-side implementation, which is run-time customisable by both the user and the party offering the service. In each case, a generic architecture is produced to support dynamic Web services. These architectures are combined to produce CREWS, a Component-driven Runtime Extensible Web Service solution that enables Web services to support the ever changing needs of enterprises. A discussion of similar work is presented, identifying the strengths and weaknesses of our architecture when compared to other solutions.

Little or no empirical validation exists for many of software engineering's basic assumptions. While some of these assumptions are intuitive, the need for scientific experimentation remains clear. Several assumptions are made about the factors affecting software reuse. In particular, the object-oriented paradigm and various human factors are hypothesized to affect the successful reuse of software components. This dissertation describes a controlled experiment designed to evaluate the impact of the object-oriented paradigm and human factors on software reuse. The human factors under investigation include managerial influence and cognitive abilities. This experiment concludes (a) the object-oriented paradigm makes significant contributions to productivity, (b) language differences are far more important when programmers reuse than when they do not, and (c) the object-oriented paradigm holds a particular affinity to the reuse process, (d) reuse results in higher productivity than no reuse independent of language paradigm, (e) the level of management encouragement does affect the reuse process, and (f) the cognitive ability of visualization does relate to effective reuse. / Ph. D.

To increase productivity, application developers are using tools that allow them to create higher quality applications faster. One such set of tools, open-source frameworks, allows application developers to reuse software artifacts and should increase application quality. However, given the vast number of open-source frameworks available, users must be able to differentiate among frameworks and select the one best suited for them. In this study, we expand the taxonomy of open-source frameworks and analyze the impact of the framework's characteristics, technical quality, and social pressure on perceived usefulness and continued framework usage intention. Our findings suggest that understandability and flexibility have a significant impact on perceived ease of use, while perceived usefulness is mainly determined by flexibility and efficiency. Our research can be used to understand what influences developers to continue using frameworks and to improve framework development. / viii, 129 leaves : ill. ; 29 cm

Thesis (Ph.D)--Computing, Georgia Institute of Technology, 2010. / Committee Chair: Yannis Smaragdakis; Committee Member: Oege de Moor; Committee Member: Richard LeBlanc; Committee Member: Santosh Pande; Committee Member: Spencer Rugaber. Part of the SMARTech Electronic Thesis and Dissertation Collection.

This study evaluates three different ways of structuring a software library for an object-oriented system. The traditional class/subclass tree (CIS) is used as well as two methods from the mental model literature: hierarchical cluster analysis (HCA) of sorting data and modal block clustering (MBC) of attribute rating data (Shurtleff, Jenkins, and Sams, 1988; Tullis, 1985). Also examined in this context are two software metrics: depth-in- inheritance-tree (D IT) and response-for-class (RFC) (Lei, 1991, 1993). These two metrics had been found by Lei to correlate with the ease of maintenance of software. It was conjectured that they might also be useful in the study of mental model methods for software. Finally, student and professional programmers are explicitly compared. There has been much debate on the applicability of software-related data generated from student subjects but little research on the topic. The results indicate that subject performance with the MBC representation was worse than with the CIS representation. Also found was that performance with the HCA representation was not sufficiently better to justify the effort involved in creating the new representation. Student programmers were found in this study to be no worse than professional programmers and thus appear to be acceptable substitutes for professional programmers in a class-based search task. This study's results indicate that student response time to locate a class could be used as the lower boundary for professional programmer class locating time. The student error rates, however, could be used as the upper boundary for professional programmer error rate performance in class locating tasks. A "middle" problem was also found. Classes 1n the middle of a library representation proved to be more difficult to locate as measured by time and error rate. Finally, a higher RFC was found to increase search time for a class when it was in the middle of a library representation. A higher RFC also reduced programmer reusability ratings of a class and the programmer's confidence in the reusability rating. / Ph. D.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy