Fault-tolerant scheduling with dynamic number of replicas in heterogeneous systems

In the existing studies on fault-tolerant scheduling, the active replication schema makes use of ε + 1 replicas for each task to tolerate ε failures. However, in this paper, we show that it does not always lead to a higher reliability with more replicas. Besides, the more replicas implies more resource consumption and higher economic cost. To address this problem, with the target to satisfy the user’s reliability requirement with minimum resources, this paper proposes a new fault tolerant scheduling algorithm: MaxRe. In the algorithm, we incorporate the reliability analysis into the active replication schema and the theoretical analysis and experiments prove that the MaxRe algorithm’s schedule can certainly satisfy user’s reliability requirements. And the MaxRe scheduling algorithm can achieve the corresponding reliability with at most 70% fewer resources than the FTSA algorithm.

Structuration theory and information systems development - frameworks for practice

Giddens’ structuration theory (ST) offers an account of social life in terms of social practices developing and changing over time and space, which makes no attempt to directly theorize the Information Systems (IS) domain. IS researchers have long been interested in it as a way of deepening understanding; a common application is the analysis of empirical situations using Giddens’ ‘dimensions of the duality of structure’ model. Other writers, most notably Orlikowski, have used it help theorize the field. Often the mode of research employed has been the interpretative case study. However, direct attempts to influence practice (an important component of working in an applied field), perhaps through the vehicle of action research, have yet to be undertaken. There are at least three serious problems with attempting this. The first is the inaccessibility of the theory to IS researchers and practitioners. The second is the absence of specific theories of technology. The third is Giddens’ own disinterest in practical uses of his work – which leaves no obvious path to follow. This paper explores that path, in the context of information system development (ISD). Some frameworks for practice are suggested which are translated into forms of discourse that are more accessible to the IS community. In particular, we include an empirical illustration to demonstrate the potential of ISD tools based on structuration theory.

Online context recognition in multisensor systems using Dynamic Time Warping

In this paper, we present our system for online context recognition of multimodal sequences acquired from multiple sensors. The system uses Dynamic Time Warping (DTW) to recognize multimodal sequences of different lengths, embedded in continuous data streams. We evaluate the performance of our system on two real world datasets: 1) accelerometer data acquired from performing two hand gestures and 2) NOKIA's benchmark dataset for context recognition. The results from both datasets demonstrate that the system can perform online context recognition efficiently and achieve high recognition accuracy.

Temporal data fusion in multisensor systems using dynamic time warping

Data acquired from multiple sensors can be fused at a variety of levels: the raw data level, the feature level, or the decision level. An additional dimension to the fusion process is temporal fusion, which is fusion of data or information acquired from multiple sensors of different types over a period of time. We propose a technique that can perform such temporal fusion. The core of the system is the fusion processor that uses Dynamic Time Warping (DTW) to perform temporal fusion. We evaluate the performance of the fusion system on two real world datasets: 1) accelerometer data acquired from performing two hand gestures and 2) NOKIA’s benchmark dataset for context recognition. The results of the first experiment show that the system can perform temporal fusion on both raw data and features derived from the raw data. The system can also recognize the same class of multisensor temporal sequences even though they have different lengths e.g. the same human gestures can be performed at different speeds. In addition, the fusion processor can infer decisions from the temporal sequences fast and accurately. The results of the second experiment show that the system can perform fusion on temporal sequences that have large dimensions and are a mix of discrete and continuous variables. The proposed fusion system achieved good classification rates efficiently in both experiments

A theory of change framework for developing cross-faculty programs : an information systems perspective

Information systems (IS) is a discipline that draws upon many other disciplines to bridge theory and practice and address the information and knowledge needs of individuals, organisations and society. We propose that an ideal education in IS would be delivered via cross-faculty programs of study that are not combinations of units from different faculties and disciplines, but programs which include a coherent and cohesive set of units co-designed and co-delivered by teaching staff from more than one faculty. This allows students, and teachers, to appreciate the different content and perspectives within the same context, as they will experience in the workplace, and allow them to develop deeper understandings of the complexity that can arise in their roles as mediators and communicators in finding appropriate IT solutions. Such a model poses a radical change, and thus the framework we offer uses a ‘theory of change’ agenda.

Stability analysis of grid-connected photovoltaic systems using a linear zero dynamic controller

This paper proposed a new linear zero dynamic controller (LZDC) for