Mobile tele-echography: user interface design.

Ultrasound imaging allows the evaluation of the degree of emergency of a patient. However, in some instances, a well-trained sonographer is unavailable to perform such echography. To cope with this issue, the Mobile Tele-Echography Using an Ultralight Robot (OTELO) project aims to develop a fully integrated end-to-end mobile tele-echography system using an ultralight remote-controlled robot for population groups that are not served locally by medical experts. This paper focuses on the user interface of the OTELO system, consisting of the following parts: an ultrasound video transmission system providing real-time images of the scanned area, an audio/video conference to communicate with the paramedical assistant and with the patient, and a virtual-reality environment, providing visual and haptic feedback to the expert, while capturing the expert's hand movements. These movements are reproduced by the robot at the patient site while holding the ultrasound probe against the patient skin. In addition, the user interface includes an image processing facility for enhancing the received images and the possibility to include them into a database.     

On the mechanisms of adenosine induced pulmonary vasoconstriction in rats

The effect of adenosine on pulmonary vessels was studied in isolated perfused rat lungs. Drugs were administered intra-arterially in a fixed volume of 0.1 ml Krebs solution as bolus injections. Adenosine responses were obtained before and 10 min after drug injections. When applied in logarithmically increasing doses (1-100 micrograms/ml), adenosine caused dose-dependent increases in pulmonary perfusion pressure (e.g. pulmonary vasoconstriction) which were readily reversible. Challenging adenosine with quinidine, dihydroergocristine and cyproheptadine (2 micrograms/ml each) did not significantly alter adenosine responses. Pretreatment of lungs with 0.5 mM theophylline, 10 micrograms/ml indomethacin, 30 micrograms/ml tebokan (a PAF antagonist) or 1 microgram/ml methylene blue for 10 min, however, antagonized the vasoconstrictor effect of the drug significantly. From these experiments, it was concluded that the mechanisms underlying the pulmonary vasoconstrictor action of adenosine are complex, and that both types of purinoceptors, prostaglandins, PAF and other vascular endothelial hormones might be involved.     

Access Time Minimization for Distributed Multimedia Applications

The problem of minimizing the access time of a requested multimedia (MM) document on a network based environment is addressed. A generalized version of this problem is formulated and retrieval strategies that minimize the access time of the user-requested MM document from a pool of MM servers are proposed. To this end, we design single-installment and multi-installment MM document retrieval strategies, through which the minimization of access time can be carried out. The main idea is to utilize more than one MM server in downloading the requested document. Each server assumes the responsibility of uploading a predetermined portion of the entire document in a particular order. Single- and multi-installment strategies differ in the number of disjoint document pieces each server sends to the client. We first introduce a directed flow graph (DFG) model to represent the retrieval process and generate a set of recursive equations using this DFG. Then, we derive closed-form solutions for the portions of the MM document downloaded from the various servers and the corresponding access time. We present rigorous analysis for these two strategies and show their performance under MPEG-I and MPEG-II video streams playback rates. Their behavior under different network bandwidths is also examined, revealing in-depth information about their expected performance. We also show that in the case of a multi-installment strategy, the access time can be completely controlled by fine tuning the number of installments. Since the number of installments is software tunable, the adaptive nature of the strategies to different channel bandwidths is also demonstrated. Important trade-off studies with respect to the number of servers involved in the retrieval process and the number of installments are presented. In the case of a heterogeneous network employing a single-installment strategy, we prove that the access time is independent of the server sequence used. Illustrative examples are provided for ease of understanding.     

Transferrin-Decorated Niosomes with Integrated InP/ZnS Quantum Dots and Magnetic Iron Oxide Nanoparticles: Dual Targeting and Imaging of Glioma

The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting. Transmission electron microscopy confirmed the complete co-encapsulation of MIONs and QDs in the niosomes. Flow cytometry analysis demonstrated enhanced cellular uptake of the niosomal formulation by glioma cells. In vitro imaging studies showed that PEGNIO/QDs/MIONs/Tf produces an obvious negative-contrast enhancement effect on glioma cells by magnetic resonance imaging (MRI) and also improved fluorescence intensity under fluorescence microscopy. This novel platform represents the first niosome-based system which combines magnetic nanoparticles and QDs, and has application potential in dual-targeted imaging of glioma.     

Introducing two landscape components from Turkey: Irim and Kesik

A very particular set of landscape components, namely the irim and the kesik, found in the peri-urban rural area called Karabaglar, are considered. This area is in the contiguous land of the city of Mugla, in southwestern Turkey, and is administered by its municipality. It has a rural character, yet also includes summerhouses for the inhabitants of the city. Physical resemblance of the irim and the kesik to the hedgerow suggests similar functions, but a closer look reveals that they have a wider range of features and aspects. Functioning not only as a marker of agricultural land sub-divisions, they also play an important role in the hydrology of the area. While their specific traditional features can be used in designed landscapes, the intention here is, first, to introduce the irim, the kesik and the very special setting offered by Karabaglar, which are now under the pressure of urban encroachment. A comparison with the hedgerow is nevertheless useful in order to better understand related aspects and features.     

New partial differential equations governing the joint, response–excitation, probability distributions of nonlinear systems, under general stochastic excitation

In the present work the problem of determining the probabilistic structure of the dynamical response of nonlinear systems subjected to general, external, stochastic excitation is considered. The starting point of our approach is a Hopf-type equation, governing the evolution of the joint, response–excitation, characteristic functional. Exploiting this equation, we derive new linear partial differential equations governing the joint, response–excitation, characteristic (or probability density) function, which can be considered as an extension of the well-known Fokker–Planck–Kolmogorov equation to the case of a general, correlated excitation and, thus, non-Markovian response character. These new equations are supplemented by initial conditions and a marginal compatibility condition (with respect to the known probability distribution of the excitation), which is of non-local character. The validity of this new equation is also checked by showing its equivalence with the infinite system of moment equations. The method is applicable to any differential system, in state-space form, exhibiting polynomial nonlinearities. In this paper the method is illustrated through a detailed analysis of a simple, first-order, scalar equation, with a cubic nonlinearity. It is also shown that various versions of Fokker–Planck–Kolmogorov equation, corresponding to the case of independent-increment excitations, can be derived by using the same approach.

A numerical method for the solution of these new equations is introduced and illustrated through its application to the simple model problem. It is based on the representation of the joint probability density (or characteristic) function by means of a convex superposition of kernel functions, which permits us to satisfy a priori the non-local marginal compatibility condition. On the basis of this representation, the partial differential equation is eventually transformed to a system of ordinary differential equations for the kernel parameters. Extension to general, multidimensional, dynamical systems exhibiting any polynomial nonlinearity will be presented in a forthcoming paper.     

Web-based teaching in software engineering

The introduction of the new technologies of computer networks and hypermedia systems in education seems promising. However, only through experimentation can the effectiveness of these technologies be demonstrated. This was the main objective of the EONT project, in the process of which the National Technical University of Athens adapted an introductory course in Software Engineering to a novel enriched instructional delivery mode. The existing course material was supplemented by Web-based courseware, integrated into a Web-based novel networked learning environment. In this article we report on the results of our research and development, concerning this particular course, and discuss the results that were obtained from our evaluation study.     

An L norm for efficient power quality monitoring

Real-time monitoring of power quality requires extensive data-handling and data-processing capabilities. These requirements limit the scope of monitoring, despite the fact that microprocessor-based monitoring systems have seen significant increase in their storage and computational power. Development of compact algorithms will benefit power quality in two ways; they will allow monitoring of more points simultaneously for large systems, and they will help create powerful embeddable monitoring architectures within small power devices, such as a breaker, motors, or power drives. This paper proposes use of the distance L¹ norm as an indicator of power quality. We show how this approach will improve the computational and storage requirements. This work presents analyses of the proposed norm, how it compares with traditional approaches, and examples of its applications.     

Smart dynamic rotor control using active flaps on a small‐scale wind turbine: aeroelastic modeling and comparison with wind tunnel measurements

In this paper, the proof of concept of a smart rotor is illustrated by aeroelastic simulations on a small‐scale rotor and comparison with wind tunnel experiments. The application of advanced feedback controllers using actively deformed flaps in the wind tunnel measurements is shown to alleviate dynamic loads leading to considerable fatigue load reduction. The numerical method for aeroelastically simulating such an experiment is described, together with the process of verifying the methods for accurate prediction of the load reduction potential of such concepts. The small‐scale rotor is simulated using the aeroelastic tool, load predictions are compared with the wind tunnel measurements, and similar control concepts are compared and evaluated in the numerical environment. Conclusions regarding evaluation of the performance of smart rotor concepts for wind turbines are drawn from this threefold research investigation (simulation, experiment and comparison). Copyright © 2012 John Wiley & Sons, Ltd.     

Controlling aggregate thin film surface morphology for improved light trapping using a patterned deposition rate profile

This work focuses on modeling and control of aggregate thin film surface morphology for improved light trapping using a patterned deposition rate profile. The dynamics of the evolution of the thin film surface height profile are modeled by an Edwards–Wilkinson-type equation (a second-order stochastic partial differential equation) in two spatial dimensions. The thin film surface morphology is characterized in terms of aggregate surface roughness and surface slope. These variables are computed with respect to appropriate visible light-relevant characteristic length scales and defined as the root-mean-squares of height deviation and slope of aggregate surface height profiles, respectively. Analytical solutions of the expected aggregate surface roughness and surface slope are obtained by solving the Edwards–Wilkinson equation and are used in the controller design. The model parameters of the Edwards–Wilkinson equation are estimated from kinetic Monte-Carlo simulations using a novel parameter estimation procedure. This parameter dependence on the deposition rate is used in the formulation of the predictive controller to predict the influence of the control action on the surface roughness and slope at the end of the growth process. The cost function of the controller involves penalties on both aggregate surface roughness and mean slope from set-point values as well as constraints on the magnitude and rate of change of the control action. The controller is applied to the two-dimensional Edwards–Wilkinson equation. Simulation results show that the proposed controller successfully regulates aggregate surface roughness and slope to set-point values at the end of the deposition that yield desired levels of thin film reflectance and transmittance.