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Discussion of XML focuses on indexing techniques for XML documents, grouping them into flat-file, semistructured, and structured indexing paradigms. Highlights include searching techniques, including full text search and multistage search; search result presentations; database and information retrieval system integration; XML query languages; and retrieval models. (Author/LRW)

Due to the increasing scale and complexity of software products, software maintenance especially on bug resolution has become a challenging task. Generally in large-scale software programs, developers depend on software artifacts (e.g., bug report, source code and change history) in bug repositories to complete the bug resolution task. However, a mountain of submitted bug reports every day increase the developers' workload. Therefore, 'How to effectively resolve software defects by utilizing software artifacts?' becomes a research hotspot in software maintenance. Considerable studies have been done on bug resolution by using multi-techniques, which cover data mining, machine learning and natural language processing. In this paper, we present a literature survey on tasks, challenges and future directions of bug resolution in software maintenance process. Our investigation concerns the most important phases in bug resolution, including bug understanding, bug triage and bug fixing. Moreover, we present the advantages and disadvantages of each study. Finally, based on the investigation and comparison results, we propose the future research directions of bug resolution. [ABSTRACT FROM AUTHOR]

In wireless sensor networks (WSNs), congestion may lead to a plethora of malfunctions such as packet loss, lower throughput and energy inefficiency, potentially resulting in reduced deployment lifetimes and under-performing applications. In this paper, we comprehensively investigate the drawbacks to the CTP protocol in congestion control and propose an ECA-CTP protocol that is equipped with an enhanced congestion avoidance mechanism. Distinguished from the existing protocols, the ECA-CTP protocol detects node-level and link-level congestion by queue full degree (FD) and congestion degree (CD) respectively, which are used to drive the selection of the proper parent nodes for rerouting paths as needed under an overall routing metric. We implemented the enhanced congestion avoidance mechanism for the ECA-CTP protocol based on the Forwarding Engine, Routing Engine and Link Estimator in the CTP protocol executing under the TinyOS platform. The experimental results show that ECA-CTP improves the throughput performance, and provides better performance in data yield when the sending interval is small. Moreover, ECA-CTP reduces the average energy consumption for every packet successfully received by the sink, which again validates the effectiveness of ECA-CTP. We believe that the enhanced congestion avoidance mechanism of ECA-CTP is an effective method to improve network performance when congestion is frequent. [ABSTRACT FROM AUTHOR]

Computation and networking resources in mobile operating environments are much scarcer and more dynamic than in desktop operating environments. Mobile applications can leverage on the benefits of adaptive computing to optimize the quality-of- service (QoS) delivery based on dynamic contextual situations. Fuzzy control models have been successfully applied to various distributed network QoS management systems. However, existing models are either application-specific or limited to abstract modeling and simple conceptual scenarios that do not take into account overall model scalability. Specifically, the large number of QoS parameters in a mobile operating environment causes the rule-explosion problem, in which an exponential increase in the number of rules correspondingly increases the demand for processing power to infer the rules. Hierarchical fuzzy systems were introduced to reduce the number of rules using hierarchical fuzzy control, in which correlated linguistic variables are hierarchically inferred and grouped into abstract linguistic variables. In this paper, we propose a mobile QoS management framework that uses a hierarchical fuzzy control model to support a highly extensible and structured adaptation paradigm. The proposed framework integrates several levels of QoS abstractions derived from user-perceived requirements. It also maps these abstractions to appropriate QoS resources that drive the development of mobile services that mitigate the effects of varying mobile environments. [ABSTRACT FROM AUTHOR]