209 research outputs found
Testing the robustness of attribution methods for convolutional neural networks in MRI-based Alzheimer's disease classification
Attribution methods are an easy to use tool for investigating and validating
machine learning models. Multiple methods have been suggested in the literature
and it is not yet clear which method is most suitable for a given task. In this
study, we tested the robustness of four attribution methods, namely
gradient*input, guided backpropagation, layer-wise relevance propagation and
occlusion, for the task of Alzheimer's disease classification. We have
repeatedly trained a convolutional neural network (CNN) with identical training
settings in order to separate structural MRI data of patients with Alzheimer's
disease and healthy controls. Afterwards, we produced attribution maps for each
subject in the test data and quantitatively compared them across models and
attribution methods. We show that visual comparison is not sufficient and that
some widely used attribution methods produce highly inconsistent outcomes
Production of Ultra-Cold-Neutrons in Solid \alpha-Oxygen
Our recent neutron scattering measurements of phonons and magnons in solid
\alpha-oxygen have led us to a new understanding of the production mechanismen
of ultra-cold-neutrons (UCN) in this super-thermal converter. The UCN
production in solid \alpha-oxygen is dominated by the excitation of phonons.
The contribution of magnons to UCN production becomes only slightly important
above E >10 meV and at E >4 meV. Solid \alpha-oxygen is in comparison to solid
deuterium less effcient in the down-scattering of thermal or cold neutrons into
the UCN energy regime.Comment: 4 pages, 5 figuer
Service robotics: do you know your new companion? Framing an interdisciplinary technology assessment
Service-Robotic—mainly defined as “non-industrial robotics”—is identified as the next economical success story to be expected after robots have been ubiquitously implemented into industrial production lines. Under the heading of service-robotic, we found a widespread area of applications reaching from robotics in agriculture and in the public transportation system to service robots applied in private homes. We propose for our interdisciplinary perspective of technology assessment to take the human user/worker as common focus. In some cases, the user/worker is the effective subject acting by means of and in cooperation with a service robot; in other cases, the user/worker might become a pure object of the respective robotic system, for example, as a patient in a hospital. In this paper, we present a comprehensive interdisciplinary framework, which allows us to scrutinize some of the most relevant applications of service robotics; we propose to combine technical, economical, legal, philosophical/ethical, and psychological perspectives in order to design a thorough and comprehensive expert-based technology assessment. This allows us to understand the potentials as well as the limits and even the threats connected with the ongoing and the planned implementation of service robots into human lifeworld—particularly of those technical systems displaying increasing grades of autonomy
Compression of TW class laser pulses in a planar hollow waveguide for applications in strong-field physics
Dualities and dilemmas: contending with uncertainty in large-scale safety-critical projects
© 2016, Informa UK Limited, trading as Taylor & Francis Group. Uncertainty is a fact of project life. Most decisions that are made on a safety-critical project involve uncertainty, the consequences of which may be highly significant to the safe and timely delivery of the project. Based on interviews with project management practitioners on nine large-scale civil nuclear and aerospace projects, we explore how uncertainty emerges, and how project management practitioners identify, analyse and act on it. We make three important contributions. First, we present three approaches – structural, behavioural and relational – that individuals and organizations can adopt when contending with project uncertainty. Secondly, we characterize nine dualities at play in the management of project uncertainty and thirdly, we identify key differences between how civil nuclear and aerospace project managers confront project uncertainty, which have important implications for how projects might be organized in both these industry sectors. Drawing attention to the structural, behavioural and relational approaches to project uncertainty and the tensions that manifest themselves in each approach should enable the project management community to make progress in environments of high uncertainty where situations are often complex, rapidly changing and confusing, and yet where, for reasons of safety, failure is not an option
Timing and Tempo of Early and Successive Adaptive Radiations in Macaronesia
The flora of Macaronesia, which encompasses five Atlantic archipelagos (Azores, Canaries, Madeira, Cape Verde, and Salvage), is exceptionally rich and diverse
Intravesical Treatments of Bladder Cancer: Review
For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy
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