Competitive Benchmarking: An IS Research Approach to Address Wicked Problems with Big Data and Analytics

Wicked problems like sustainable energy and financial market stability are societal challenges that arise from complex socio-technical systems in which numerous social, economic, political, and technical factors interact. Understanding and mitigating them requires research methods that scale beyond the traditional areas of inquiry of Information Systems (IS) “individuals, organizations, and markets” and that deliver solutions in addition to insights. We describe an approach to address these challenges through Competitive Benchmarking (CB), a novel research method that helps interdisciplinary research communities to tackle complex challenges of societal scale by using different types of data from a variety of sources such as usage data from customers, production patterns from producers, public policy and regulatory constraints, etc. for a given instantiation. Further, the CB platform generates data that can be used to improve operational strategies and judge the effectiveness of regulatory regimes and policies. We describe our experience applying CB to the sustainable energy challenge in the Power Trading Agent Competition (Power TAC) in which more than a dozen research groups from around the world jointly devise, benchmark, and improve IS-based solutions

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Network Analysis, Creative System Modelling and Decision Support: The NetSyMoD Approach

This paper presents the NetSyMoD approach where NetSyMod stands for Network Analysis Creative System Modelling Decision Support. It represents the outcome of several years of research at FEEM in the field of natural resources management, environmental evaluation and decision-making, within the Natural Resources Management Research Programme. NetSyMoD is a flexible and comprehensive methodological framework, which uses a suite of support tools, aimed at facilitating the involvement of stakeholders or experts in decision-making processes. The main phases envisaged for the process are: (i) the identification of relevant actors, (ii) the analysis of social networks, (iii) the creative system modelling and modelling of the reality being considered (i.e. the local socio-economic and environmental system), and (iv) the analysis of alternative options available for the management of the specific case (e.g. alternative projects, plans, strategies). The strategies for participation are necessarily context-dependent, and thus not all the NetSyMod phases may be needed in every application. Furthermore, the practical solutions for their implementation may significantly differ from one case to another, depending not only on the context, but also on the available resources (human and financial). The various applications of NetSyMoD have nonetheless in common the same approach for problem analysis and communication within a group of actors, based upon the use of creative thinking techniques, the formalisation of human-environment relationships through the DPSIR framework, and the use of multi-criteria analysis through the mDSS software

Geomorphic and vegetative recovery processes along modified stream channels of West Tennessee

Hundreds of miles of streams in West Tennessee have been channelized or otherwise modified since the tum of century. After all or parts of a stream are straightened, dredged, or cleared, systematic hydrologic, geomorphic, and ecologic processes collectively begin to reduce energy conditions towards the premodified state. One hundred and .five sites along 15 streams were studied in the Obion, Forked Deer, Hatchie. and Wolf River basins. All studied streams, except the Hatchie River, have had major channel modification along all or parts of their courses. Bank material shear-strength properties were determined through drained borehole-shear testing (168 tests) and used to interpret present critical bank conditions andfactors of safety, and to estimate future channel-bank stability. Mean values of cohesive strength and angle ofintemalfriction were 1.26 pounds per square inch and 30.1 degrees, respectively. Dendrogeomorphic analyses were made using botanical evidence of channel-bank failures to detennine rates of channel widening, buried riparian stems were analyzed to determine rates of bank accretion. Channel bed-level changes through time and space were represented by a power equation. Plant ecological analyses were made to infer relative bank stability, to identifY indicator species of the stage of bank recovery, and to determine patterns of vegetation development through the course of channel evolution. Quantitative data on morphologic changes were used with previously developed six-stage models of channel evolution and bank-slope development to estimate trends of geomorphic and ecologic processes and forms through time. Immediately after channel modifications, a 1(}- to 15-year period of channel-bed degradation ensues at and upstream from the most recenf modifications (area of maximum disturbance). Channel-bed lowering by degradation was as much as 20 feet along some stream reaches. Downstream from the area of maximum disturbance, the bed was aggraded by the deposition of sediment supplied by knickpoint migration upstream; aggradation also occu"ed in initially degraded sites with time. Additionally, if degradation caused an increase in bank height beyond the critical limits of the bank material, a period of channel widening by mass wasting followed. Degradation knickpoints migrated upstream at rates greater than 1 mile per year,· the rates attenuated with distance above the area of maximum disturbance. Channel widening rates of up to 16 feet per year were documented along some severely degraded reaches. Planar failures were generally more frequent but rotational failures dominated the most rapidly widening reaches. Total volumes of bank erosion may represent 75 percent or more of the total material eroded fro~ the channel, but this material generally exits the drainage basin. Mean factors of safety vary with the stage of channel evolution with the lowest values for planar and rotational failures occurring during the threshold stage (stage IV) 1.00 and 1.15, respectively. As channel gradients decrease, degradation ceases and then a period of "secondary aggradation" (at lesser rates than degradation) and bank accretion begins that may .fill the channel to near flood-plain level. This shift in process represents an oscillation in channel bed-level adjustment. Streams in basins underlain by loess may require an order of magnitude more time than sand-bed streams to stabilize due to a lack of coarse-grained material (sand) for aggradation. A systematic progression of riparian species that rej1ects the six-stage model of channel evolution has been identified. This progression can be used to irifer ambient channel stability and hydrogeomorphic conditions. Woody vegetation establishes on low- and mid-bank swfaces (the slough line, initially) at about the same time that bank accretion begins. This slough line forms at a mean temporary stability angle of 24 degrees and expands upslope with time by the accretion of sediments. Species involved in this ini,tial revegetation are hardy, fast growing, and can tolerate moderate amounts of slope instability and sedimentation; these species include river birch, black willow, boxelder and silver maple. Vegetation appears to enhance bank stability, and with increasing stability, species such as bald cypress, tupelo gum, and various hydric oaks, which are more characteristic of stable, premodified riparian settings, begin to establish. Detrended-co"espondence analysis indicated species assemblages associated with the six stages of channel evolution and bank-slope development. Ordination of site variables based on species data such as channel widening, bank accretion, and woody vegetative cover also reflects the temporal changes identified by the models. Long-tenn channel geometry was estimated from a quantitative model of bed-level change, and from documented trends in channel widening. An idealized stable channel of a major sand-bed stream may have a width/depth ratio near 10 and bank slopes of about 24 degrees. This stable channel will ultimately undergo the development of point-bars and incipient meanders, characteristic of unmodified streams

Characterization of the Interaction between Tollmien-Schlichting Waves and a DBD Plasma Actuator using Phase-locked PIV

The research reported in this study addresses the direct measurement of Tollmien-Schlichting (TS) waves on a flat plate, when the laminar boundary layer is excited by velocity perturbations. Tollmien-Schlichting waves are a precursor to natural laminar-to-turbulent transition and, if these waves can be reduced in amplitude, a transition delay can be realized, resulting in lower overall friction drag. One such means of actively suppressing TS waves is the application of dielectric barrier discharge (DBD) plasma actuators [2]. These devices can be operated in several different modes to achieve a decrease of TS-wave amplitude and the physics of the actuator/wave interaction differs for each mode. In the present study two particular modes are investigated; the boundary-layer stabilization mode, in which the actuator is operated continuously (quasi-steady); and the hybrid mode, in which the actuator amplitude is modulated about a steady value. The purpose of the present measurements is to demonstrate the feasibility of measuring the DBD actuator interaction with the TS-waves using phase-locked Particle Image Velocimetry. Obtaining such velocity field data in the interaction zone of the DBD actuator allows insight into the physics of the actuator/TS-wave interaction. However the measurements are particular challenging, since the amplitude of TS-waves in their linear growth region is typically less than 1% of the freestream velocity; therefore some particular remarks about the PIV data processing will be directed towards achieving the necessary accuracy and resolution

Herramientas para evaluar la sostenibilidad de las intervenciones urbanas en barrios: Sustainability assessment tools for urban design at neighbourhood scale

UrbanismArchitectur

A glacial isostatic adjustment model for the central and northern Laurentide ice sheet based on relative sea level and GPS measurements

The thickness and equivalent global sea level contribution of an improved model of the central and northern Laurentide Ice Sheet is constrained by 24 relative sea level histories and 18 present-day GPS-measured vertical land motion rates. The final model, termed Laur16, is derived from the ICE-5G model by holding the timing history constant and iteratively adjusting the thickness history, in four regions of northern Canada. In the final model, the last glacial maximum (LGM) thickness of the Laurentide Ice Sheet west of Hudson Bay was ~3.4-3.6 km. Conversely, east of Hudson Bay, peak ice thicknesses reached ~4 km. The ice model thicknesses inferred for these two regions represent, respectively, a ~30 per cent decrease and an average ~20-25 per cent increase to the load thickness relative to the ICE-5G reconstruction, which is generally consistent with other recent studies that have focussed on Laurentide Ice Sheet history. The final model also features peak ice thicknesses of 1.2-1.3 km in the Baffin Island region, a modest reduction relative to ICE-5G and unchanged thicknesses for a region in the central Canadian Arctic Archipelago west of Baffin Island. Vertical land motion predictions of the final model fit observed crustal uplift rates well, after an adjustment is made for the elastic crustal response to present-day ice mass changes of regional ice cover. The new Laur16 model provides more than a factor of two improvement of the fit to the RSL data (?2 measure of misfit) and a factor of nine improvement to the fit of the GPS data (mean squared error measure of fit), compared to the ICE-5G starting model. Laur16 also fits the regional RSL data better by a factor of two and gives a slightly better fit to GPS uplift rates than the recent ICE-6G model. The volume history of the Laur16 reconstruction corresponds to an up to 8 m reduction in global sea level equivalent compared to ICE-5G at LGM.Physical and Space Geodes

Joint Estimation of Hemodynamic Response and Stimulus Function in Functional Ultrasound Using Convolutive Mixtures

Functional ultrasound (fUS) is an exciting new neuroimaging technique that is able to record brain activity similar to functional magnetic resonance imaging, yet with higher spatiotemporal resolution and at lower cost. We consider the problem of jointly estimating the underlying neural sources and the hemodynamic response function (HRF) from fUS recordings. We propose to model the measured voxel time-series as a convolutive mixture of multiple source signals and solve the blind deconvolution problem via block-term decomposition. This allows us to estimate both the source time courses and a different HRF for each voxel and source combination, which accounts for the variability of HRF across different brain regions and events respectively. The proposed approach is proven to be robust against noise via simulations and further validated on real fUS data by performing a visual experiment on a mouse. The obtained results show that the proposed method is able to recover the timings of the visual paradigm.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Circuits and System

Observation and control of hybrid spin-wave-Meissner-current transport modes

Superconductors are materials with zero electrical resistivity and the ability to expel magnetic fields, which is known as the Meissner effect. Their dissipationless diamagnetic response is central to magnetic levitation and circuits such as quantum interference devices. In this work, we used superconducting diamagnetism to shape the magnetic environment governing the transport of spin waves-collective spin excitations in magnets that are promising on-chip signal carriers-in a thin-film magnet. Using diamond-based magnetic imaging, we observed hybridized spin-wave-Meissner-current transport modes with strongly altered, temperature-tunable wavelengths and then demonstrated local control of spin-wave refraction using a focused laser. Our results demonstrate the versatility of superconductor-manipulated spin-wave transport and have potential applications in spin-wave gratings, filters, crystals, and cavities.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.QN/vanderSarlabQN/Kavli Nanolab DelftQN/Blanter Grou