An analytic method to predict the thermal map of cryosurgery iceballs in MR images

This paper presents a newly developed method to estimate, in magnetic resonance (MR) images, the temperatures reached within the volume of an iceball produced by a cryogenic probe. Building on the direct measurements of the MR signal intensity and its correlation with independent temperature variations at the phase transition from liquid to solid, the thermal information embedded in the images was accessed. The volume and diameter of the growing iceball were estimated from a time series of MR images. Using regressions over the volume in the time and thermal domains, this method predicted the cryogenic temperatures beyond the range of sensitivity of the MR signal itself. We present a validation of this method in samples of gelatin and ex vivo pig liver. Temperature predictions are shown to agree with independent thermosensor readings over a range extending from 20 degrees C down to -65 degrees C, with an average error of less than 6 degrees C.     

A Memristive Nanoparticle/Organic Hybrid Synapstor for Neuroinspired Computing

A large effort is devoted to the research of new computing paradigms associated with innovative nanotechnologies that should complement and/or propose alternative solutions to the classical Von Neumann/CMOS (complementary metal oxide semiconductor) association. Among various propositions, spiking neural network (SNN) seems a valid candidate. i) In terms of functions, SNN using relative spike timing for information coding are deemed to be the most effective at taking inspiration from the brain to allow fast and efficient processing of information for complex tasks in recognition or classification. ii) In terms of technology, SNN may be able to benefit the most from nanodevices because SNN architectures are intrinsically tolerant to defective devices and performance variability. Here, spike‐timing‐dependent plasticity (STDP), a basic and primordial learning function in the brain, is demonstrated with a new class of synapstor (synapse‐transistor), called nanoparticle organic memory field‐effect transistor (NOMFET). This learning function is obtained with a simple hybrid material made of the self‐assembly of gold nanoparticles and organic semiconductor thin films. Beyond mimicking biological synapses, it is also demonstrated how the shape of the applied spikes can tailor the STDP learning function. Moreover, the experiments and modeling show that this synapstor is a memristive device. Finally, these synapstors are successfully coupled with a CMOS platform emulating the pre‐ and postsynaptic neurons, and a behavioral macromodel is developed on usual device simulator.     

A Cooperative Nearest Neighbours Topology Control Algorithm for Wireless Ad Hoc Networks

In this article, we introduce a simple distributed algorithm that assigns appropriate individual transmission powers to devices in a wireless ad hoc network. In contrast to many other proposed algorithms, it does without special hardware. It requires only local neighbourhood information and therefore avoids flooding information throughout the network. Finally, the cooperative nature of the algorithm avoids that devices cause excessive interference by using unnecessarily high transmission powers. By means of simulation, we show that the topologies created by this algorithm without any global knowledge are as effective as topologies resulting from a good choice of a common transmission power (which would require global knowledge) in terms of the achievable throughput. This work was supported in part by the German Federal Ministry of Education and Research (BMBF) as part of the IPonAir project.     

Investigating Energy Prosumer Behaviour in Crowd Energy Using an Interactive Model/Diorama

Smart living labs such as the one located in Fribourg (Switzerland) focus on improving wellbeing and furthering knowledge related to building the district of the future on a technical and social level. Therefore, smart living labs represent an experimental platform/space where sustainable production and consumption strategies can be tested in a protected environment. A significant change in the socioeconomic production and consumption sphere can be expected by the rise of the so-called energy prosumer. Accordingly, this article presents an interactive model for the experimental investigation of energy prosumer behavior. In this context, two potential experiments on investment and trade decisions are briefly outlined. Since (behavioral and economic) experiments are usually conducted under controlled conditions in experimental labs involving mainly undergraduate students, the presented interactive model is flexible and mobile, providing the advantage to conduct experiments nearly everywhere involving everyday citizens.     

Cloud Based Infrastructure,the New Business Possibilities and Barriers

Realization of the cloud computing infrastructure requires access to data anywhere, anytime at any device at a sufficient perceived quality of service. Many Western European countries, such as Denmark, have a high percentage of individuals (inhabitants and companies) that has access to broadband internet via cable, satellite and mobile. This gives a unique position in roll-out and deploying intelligent cloud based services that can be applied for a number of purposes, but where lack of sufficient capacity/quality and IT readiness will be barriers in realization of the “Global Information Multimedia Communication Village (GIMCV)”. Broadband is here defined as more than 2 Mbps. In this paper, the combination of e-commerce, cloud computing and broadband infrastructure has our focus, and its unique possibilities for the overall IT society. However, it is also about a significant number of Small and Medium sized Enterprises (SMEs) that today applies manual billing systems or Excel like systems in combination with severe lacks of sufficient IT skills. This means that the most commonly used systems are the ones requiring the most of our time. Therefore, the move for the SME towards e-commerce and electronic processes has a significant economical potential for the SMEs. E-commerce and other internet based services will simplify their business, and hence allow the SMEs to focus on their core business which was their raison d’être. In addition to this can be added other fundamental IT systems that will help their business, but that is outside the scope of this paper. Furthermore, this paper focuses on infrastructural barriers and cloud computing; not only focusing on bandwidth, but also the entire issue of service offering. Services offered via cloud computing solutions will minimize the SMEs investment in own hardware (HW), software (SW) and maintenance. The focus is also the upgrade to a superior infrastructure that provides the platform for efficient cloud computing, for e-commerce, and beyond.     

Quantitative evaluation of three calibration methods for 3-D freehand ultrasound

In this paper, three different calibration methods for three-dimensional (3-D) freehand ultrasound (US) are evaluated. Calibration is the process of estimating the rigid transformation from US image coordinates to the coordinate system of the tracking sensor mounted onto the probe. Calibration accuracy has an important impact on quantitative studies. Geometrical precision can also be crucial in many interventions and surgery. The proposed evaluation framework relies on a single point phantom and a 3-D US phantom which mimics the US characteristics of human liver. Four quality measures are used: 3-D point localization criterion, distance and volume measurements, and shape based criterion. Results show that during the acquisition procedure, volumetric measurements and shapes of the reconstructed object depend on probe motion used, particularly fan motions for which errors are larger. It is also shown that accurate calibration is essential to obtain reliable quantitative information.