M. Usman Iftikhar

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Self-adaptation is a promising approach to manage the complexity of modern software systems. A self-adaptive system is able to adapt autonomously to internal dynamics and changing conditions in the environment to achieve particular quality goals. Our particular interest is in decentralized selfadaptive systems, in which central control of adaptation is not(More)
Despite the vast body of work on self-adaption, no systematic study has been performed on the claims associated with self-adaptation and the evidence that exists for these claims. As such an insight is crucial for researchers and engineers, we performed a literature study of the research results from SEAMS since 2006 and the associated Dagstuhl seminar in(More)
Providing high-quality software in the face of uncertainties, such as dealing with new user needs, changing availability of resources, and faults that are difficult to predict, raises fundamental challenges to software engineers. These challenges have motivated the need for self-adaptive systems. One of the primary claimed benefits of self-adaptation is(More)
Data gathering in a timely and reliable fashion has been a key concern in wireless sensor networks particularly related to military applications. The introduction of real time communication has created additional challenges in this area with different communication constraints. Since sensor networks represent a new generation of time-critical applications,(More)
Over the past few years, we have witnessed a growing popularity of new wireless architectures such as 3G, Wi-Fi and Wi-Max due to the increase in demand for wireless Internet access. The all-IP based future mobile and wireless network model is expected to be the most dominant architecture for QoS provisioning in next-generation wireless networks, mainly due(More)
Designing software systems with uncertainties, such as incomplete knowledge about changing system goals, is challenging. One approach to handle uncertainties is self-adaptation, where a system consists of a managed system and a managing system that realizes a feedback loop. The promise of self-adaptation is to enable a system to adapt itself realizing the(More)
Today customers require software systems to provide particular levels of qualities, while operating under dynamically changing conditions. These requirements can be met with different self-adaptation approaches. Recently, we developed two approaches that are different in nature - control theory-based SimCA and architecture-based ActivFORMS - to endow(More)
There is a growing interest of wireless operators to migrate their existing 3G networks to different 4G technologies such as WiMAX and LTE. In this heterogeneous environment of wireless networks and architectures, one of the major concerns is how to allocate network resources efficiently to diverse traffic classes with different QoS constraints. Further it(More)
Modern software systems are subject to uncertainties, such as dynamics in the availability of resources or changes of system goals. Self-adaptation enables a system to reason about runtime models to adapt itself and realises its goals under uncertainties. Our focus is on providing guarantees for adaption goals. A prominent approach to provide such(More)