Uncertainty Management of Intelligent Feature Selection in Wireless Sensor Networks

Wireless sensor networks (WSN) are envisioned to revolutionize the paradigm of monitoring complex real-world systems at a very high resolution. However, the deployment of a large number of unattended sensor nodes in hostile environments, frequent changes of environment dynamics, and severe resource constraints pose uncertainties and limit the potential use of WSN in complex real-world applications. Although uncertainty management in Artificial Intelligence (AI) is well developed and well investigated, its implications in wireless sensor environments are inadequately addressed. This dissertation addresses uncertainty management issues of spatio-temporal patterns generated from sensor data. It provides a framework for characterizing spatio-temporal pattern in WSN. Using rough set theory and temporal reasoning a novel formalism has been developed to characterize and quantify the uncertainties in predicting spatio-temporal patterns from sensor data. This research also uncovers the trade-off among the uncertainty measures, which can be used to develop a multi-objective optimization model for real-time decision making in sensor data aggregation and samplin

British and Fennoscandian Ice-Sheet interactions during the quaternary

Northeastern England and the North Sea Basin is a critical location to examine the influence of glaciation in the northern Hemisphere during the Quaternary. This region was a zone of confluence between the British and Fennoscandian Ice Sheets, and harboured several dynamic ice lobes sourced from northern Scotland, the Cheviots, the Lake District and the Southern Uplands. The region thus has some of the most complex exposures of Middle to Late Pleistocene sediments in Britain, with both interglacial and glacial sediments deposited in terrestrial and marine settings, and being sourced from both the British Isles and northern continental Europe. The research undertaken involved a thorough reinvestigation of the Quaternary sediments of northeast England, making use of enhanced exposures in coastal sections following the cessation of colliery waste dumping, and in boreholes from the North Sea. It used detailed sedimentological, stratigraphical, chronostratigraphical, lithological, petrological, and geochemical techniques to investigate their depositional processes, age, provenance signatures, and regional correlatives to construct an independent model of the eastern margin of the British-Irish Ice Sheet (BUS) throughout the Quaternary, and its interaction in the North Sea Basin with the Fennoscandian Ice Sheet (PIS). This region was a zone of confluence between ice lobes sourced from northern Scotland, the Cheviots, the Lake District and the Southern Uplands, and is ideally placed for investigating the geological record of the North Sea Lobe during the Late Devensian. In addition. County Durham has one of the most northerly exposures of Middle Pleistocene sediments in Britain, including a raised beach and a Scandinavian till. This project focussed on a variety of localities in northeastern England and in the North Sea Basin, including Whitburn Bay, Shippersea Bay, Hawthorn Hive, and Warren House Gill. At Whitburn Bay, the Blackhall and Horden glacigenic members are exposed in superposition and are Late Devensian in age. The lower Blackhall Member here is interpreted as a subglacial traction till with a high percentage of locally derived erratics. A boulder pavement at the top of the till points to a switch in ice-bed conditions and the production of a melt-out lag prior to the deposition of the upper, Horden Member. This second traction till contains erratics and heavy minerals derived from crystalline bedrock sources in the Cheviot Hills and northeast Scotland, including tremolite, andalusite, kyanite and rutile. Within the Horden Member are numerous sand, clay and gravel-filled channels incised into the diamicton, which are attributed to a low energy, distributed, subglacial canal drainage system. Coupled with the hydrofractures and the boulder pavement, this suggests that a partly decoupled, fast flowing ice stream deposited the Horden Member. The eastward, on-shore direction of ice movement indicates that the ice stream was confined in the North Sea Basin, possibly by the presence of Scandinavian ice. From Hawthorn Hive to Warren House Gill, the Blackhall and Horden members are separated by the Peterlee Sands and Gravels, ice-proximal outwash sediments. Beneath the glacial sequence, some 500 m to the south is the Easington Raised Bench. The partly calcreted interglacial beach lies directly on Magnesian Limestone bedrock at 33 m O.D., and consists of beds of unconsolidated, well-bedded, imbricated, well- rounded sands and gravels. It has been dated to MIS 7 by amino acid geochronology and OSL dating. The beach contains exotic gravel, including flint, and previous workers have reported Norwegian erratics. The only currently extant source for these is the Scandinavian Drift at Warren House Gill. Warren House Gill is a classic Middle Pleistocene site, and has a complex stratigraphy, consisting of a lower "Scandinavian Drift" with overlying estuarine sediments, and an upper "Main Cheviot Drift", which comprises two tills and glaciotectonised, interstratified sands and silts, traditionally interpreted as Devensian in age. The lowest grey Scandinavian Drift is a grey, laminated clay with dropstones. It contains marine bivalve fragments, foraminifera, and clasts of northeastern Scotland and Norwegian provenance, as well as Magnesian Limestone, chalk, flint, and Triassic red marl from the North Sea. Reworked palynomorphs include Eocene dinoflagellate cysts. This is interpreted as a Middle Pleistocene glaciomarine deposit, and is renamed the 'Ash Gill Member' of the Warren House Formation, with inputs from both Scottish and Scandinavian sources. It is dated to the Middle Pleistocene by AAR dates on the shell fauna, and by the relationship to the MIS 7 age raised beach. The overlying well sorted pink and red interbedded sands and silts contain carbonate nodules and rare clasls. These shallow subaqueous sediments were deposited through suspension settling and bottom current activity, and they may be reworked loess. They are named the 'Whitesides Member' and are the highest member in the Warren House Formation. The overlying "Cheviot Drift" consists of two ice-marginal traction tills (the Blackhall and Horden members), separated by interbedded glaciofluvial red silts and sands. The till lithologies are indicative of a northern British provenance, and are rich in limestone, coal, sandstone, greywacke and dolerile. The Blackhall Member was deposited by ice during MIS 4, during a period of maximum extent of the British and Fennoscandian ice sheets and contact in the central North Sea. The Horden Member was deposited in an ice- marginal landsystem by the Late Devensian North Sea Lobe, and is correlative with the Skipsea Member in Yorkshire and the Bolders Bank Formation offshore. The Swarte Bank, Coal Pit, Fisher and Bolders Bank formations from the North Sea Basin were also examined. These subglacial and glaciomarine sediments, ranging from MIS 12 to MIS 2 in age, were all found to show a similar provenance from the Grampians, Aberdeenshire and the Scottish Highlands, indicating repeat ice-flow pathways during the Quaternary. This research has significant implications for British Quaternary stratigraphy, as it indicates that Fennoscandian ice was a significant influence on the BIIS throughout the Quaternary, and that on multiple occasions, Fennoscandian ice directly impacted the coast of eastern England. During MIS 12, a marine embayment opened in northeast England between the British and Fennoscandian ice sheets. Ice rafted material derived from both Scottish and Norwegian sources was deposited in this marine embayment. The Ash Gill Member of the Warren House Formation is an isolated remnant of this ancient glaciomarine environment, and it is separated from the overlying Devensian sediments by a substantial unconformity. During the Early Devensian, ice sourced in Scotland flowed eastwards through the Tyne Gap, where it was joined by a minor component of Lake District ice. This was a stage of maximum configuration of the BIIS, with contact with the FIS offshore. During the Last Glacial Maximum, the North Sea Lobe was constrained by the FIS offshore, forcing the North Sea Lobe onshore. This project found no evidence of Lake District erratics in County Durham, but found detrital material in the subglacial tills from the coast of northeastern Scotland

Rejection-oriented learning without complete class information

Machine Learning is commonly used to support decision-making in numerous, diverse contexts. Its usefulness in this regard is unquestionable: there are complex systems built on the top of machine learning techniques whose descriptive and predictive capabilities go far beyond those of human beings. However, these systems still have limitations, whose analysis enable to estimate their applicability and confidence in various cases. This is interesting considering that abstention from the provision of a response is preferable to make a mistake in doing so. In the context of classification-like tasks, the indication of such inconclusive output is called rejection. The research which culminated in this thesis led to the conception, implementation and evaluation of rejection-oriented learning systems for two distinct tasks: open set recognition and data stream clustering. These system were derived from WiSARD artificial neural network, which had rejection modelling incorporated into its functioning. This text details and discuss such realizations. It also presents experimental results which allow assess the scientific and practical importance of the proposed state-of-the-art methodology.Aprendizado de Máquina é comumente usado para apoiar a tomada de decisão em numerosos e diversos contextos. Sua utilidade neste sentido é inquestionável: existem sistemas complexos baseados em técnicas de aprendizado de máquina cujas capacidades descritivas e preditivas vão muito além das dos seres humanos. Contudo, esses sistemas ainda possuem limitações, cuja análise permite estimar sua aplicabilidade e confiança em vários casos. Isto é interessante considerando que a abstenção da provisão de uma resposta é preferível a cometer um equívoco ao realizar tal ação. No contexto de classificação e tarefas similares, a indicação desse resultado inconclusivo é chamada de rejeição. A pesquisa que culminou nesta tese proporcionou a concepção, implementação e avaliação de sistemas de aprendizado orientados `a rejeição para duas tarefas distintas: reconhecimento em cenário abertos e agrupamento de dados em fluxo contínuo. Estes sistemas foram derivados da rede neural artificial WiSARD, que teve a modelagem de rejeição incorporada a seu funcionamento. Este texto detalha e discute tais realizações. Ele também apresenta resultados experimentais que permitem avaliar a importância científica e prática da metodologia de ponta proposta

Tangible auditory interfaces : combining auditory displays and tangible interfaces

Bovermann T. Tangible auditory interfaces : combining auditory displays and tangible interfaces. Bielefeld (Germany): Bielefeld University; 2009.Tangible Auditory Interfaces (TAIs) investigates into the capabilities of the interconnection of Tangible User Interfaces and Auditory Displays. TAIs utilise artificial physical objects as well as soundscapes to represent digital information. The interconnection of the two fields establishes a tight coupling between information and operation that is based on the human's familiarity with the incorporated interrelations. This work gives a formal introduction to TAIs and shows their key features at hand of seven proof of concept applications

LEARNING FROM THE PAST TO FACE THE FUTURE: LANDSLIDES IN THE PIAVE VALLEY (EASTERN ALPS, ITALY)

Landslides are a critical process in landscape evolution and may pose a serious threat to people and infrastructure. In the last decades, a growing interest in such phenomena has developed in the Alps, where narrow valleys are increasingly in\uachabited, and landslides have caused several casualties. Understanding the driving factors, triggers, evolution, and impact of past and future failures is of the utmost importance when dealing with land use and risk reduction. In this paper, four distinct case stud\uacies are presented, showing how different approaches can interact and produce a comprehensive understanding of a landslide event. All examples lie in the middle sector of the Piave Valley (NE Italy) and deal with failures that occurred in the distant past (i.e., the historic Masiere di Vedana rock avalanche), in the near past (i.e., the 1963 Vajont event), in the present (i.e., the 60-years -lasting Tessina landslide) and in the future (i.e., possible Mt. Peron instabilities). The final goal of the paper is to show how the understanding of past landslides is fundamental to obtain reliable predictions on future failures, and how modelling designed to predict the evolution of potential detachments can be applied to understand the dynamics of ancient events

p-probabilistic k-anonymous microaggregation for the anonymization of surveys with uncertain participation

We develop a probabilistic variant of k-anonymous microaggregation which we term p-probabilistic resorting to a statistical model of respondent participation in order to aggregate quasi-identifiers in such a manner that k-anonymity is concordantly enforced with a parametric probabilistic guarantee. Succinctly owing the possibility that some respondents may not finally participate, sufficiently larger cells are created striving to satisfy k-anonymity with probability at least p. The microaggregation function is designed before the respondents submit their confidential data. More precisely, a specification of the function is sent to them which they may verify and apply to their quasi-identifying demographic variables prior to submitting the microaggregated data along with the confidential attributes to an authorized repository. We propose a number of metrics to assess the performance of our probabilistic approach in terms of anonymity and distortion which we proceed to investigate theoretically in depth and empirically with synthetic and standardized data. We stress that in addition to constituting a functional extension of traditional microaggregation, thereby broadening its applicability to the anonymization of statistical databases in a wide variety of contexts, the relaxation of trust assumptions is arguably expected to have a considerable impact on user acceptance and ultimately on data utility through mere availability.Peer ReviewedPostprint (author's final draft

The sedimentary and geomorphic signature of subglacial processes in the Tarfala Valley, northern Sweden, and the links between subglacial soft-bed deformation, glacier flow dynamics, and landform generation

The aim of this study is to understand the extent, depth, magnitude and significance of subglacial sediment deformation. It will examine the role of this deformation in controlling glacier dynamics and landform generation in glaciers in general, and polythermal glaciers in particular. A detailed multi-dimensional approach is used to study recently exposed glacigenic sediments on the forefields of three polyglaciers in the Tarfala Valley, northern Sweden. Overridden fluted moraines and diamicton plains occur in each forefield. These palimpsest landforms consist of multiple subglacial traction tills. Flutes have quasi-regular geometry and about half of those studied have no initiating boulder. It is suggested here that flute formation by forced-mechanisms was superimposed on flute formation related to a topographically-induced flow instability. In each forefield the depth of the deforming-bed averaged between 0.2m and 0.6m thickness. Detailed clast fabric data suggest the diamicton plain is composed of thin layers of traction tills that accreted over time as the zone of deformation moved upwards. Laboratory shear box tests show that subglacial deformation required elevated pore-water pressures, which suggests deforming-bed conditions and flute formation were restricted to the temperate zones of polythermal glaciers. Magnetic fabrics suggest strain magnitudes were moderate (≤10), rather than the very high strain magnitudes (>102) required by the deforming-bed model. The application of the micro-structural mapping technique demonstrates that subglacial deformation was multi-phase, heterogeneous, and partitioned into the softer and more easily deformed parts of the matrix. Consequently, deformation is controlled by variations in sediment granulometry and pore-water pressure, and is likely to have been spatially and temporally variable, a finding that supports the ice-bed mosaic model. The strain magnitudes and deforming-bed thickness suggest that soft-bed deformation did not exert a major control on glacier dynamics during the Little Ice Age advance