Siemens (Greece)

Cloud Computing provides functionality for managing information data in a distributed, ubiquitous and pervasive manner supporting several platforms, systems and applications. This work presents the implementation of a mobile system that enables electronic healthcare data storage, update and retrieval using Cloud Computing. The mobile application is developed using Google's Android operating system and provides management of patient health records and medical images (supporting DICOM format and JPEG2000 coding). The developed system has been evaluated using the Amazon's S3 cloud service. This article summarizes the implementation details and presents initial results of the system in practice.

This paper addresses the problem of the development of optimal offering strategies by electricity producers in day-ahead energy auctions with step-wise energy offer format. The producer energy offer optimization is formulated as a bi-level optimization problem, which is converted to a offer optimization is formulated as a bi-level optimization problem, which is converted to a mathematical program with equilibrium constraints (MPEC). The producer MPEC is subsequently converted to a mixed integer linear program (MILP) using binary expansion of offer quantities and prices. The uncertainties under which the producer must develop his offering strategy are modeled. Test results on a small, ten-unit test system address the effect of the auction settlement rules (uniform or discriminatory pricing) as well as the producer's forward commitments on the producer strategic behavior in the day-ahead energy market.

A hierarchical system for character recognition with hidden Markov model knowledge sources which solve both the context sensitivity problem and the character instantiation problem is presented. The system achieves 97-99% accuracy using a two-level architecture and has been implemented using a systolic array, thus permitting real-time (1 ms per character) multifont and multisize printed character recognition as well as handwriting recognition.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The paper briefly compares the architecture of commonly used channel sounders for single input multiple output (SIMO) and multiple input multiple output (MIMO) applications. The architecture of a novel dual UMTS band parallel receiver sounder developed for the purposes of such studies is outlined. The performance of the sounder from back-to-back measurements and calibration considerations are discussed. Outdoor SIMO measurements and indoor/outdoor MIMO measurements obtained with different antenna arrays demonstrate its capability.

The main aim of this study was the comparative evaluation of nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS), fibrosis 4 index (FIB-4), AST-to-Platelet Ratio Index (APRI), and enhanced liver fibrosis (ELF) test in distinguishing none/early (F0/F1) from significant/advanced (F2/F3) fibrosis in NAFLD patients, thereby providing an external validation cohort. Thirty-one patients with biopsy-proven NAFLD and 10 matched controls without NAFLD were prospectively enrolled. Serum hyaluronic acid (HA), aminoterminal propeptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases (TIMP)-1, and biochemical tests were measured. NFS, FIB-4, APRI, and ELF were calculated. ELF, FIB-4, and APRI, but not NFS, were higher in F2/F3 than F0/F1 group. Specifically, ELF [area under the ROC curve (AUROC): 0.86±0.10; p=0.004) and APRI (AUROC: 0.86±0.07; p=0.005], but not NFS (AUROC: 0.68±0.12; p=0.16), and FIB-4 (AUROC: 0.71±0.11; p=0.10), could similarly discriminate F0/F1 from F2/F3 stage. The sensitivity, specificity, positive predicted value (PPV), and negative predicted value (NPV) were: a) for cut-off of APRI=0.5, 85.7%, 70.8%, 46.2%, and 94.4%, respectively, and b) for cut-off of ELF=9.0, 85.7%, 83.3%, 60.0%, and 95.2%, respectively. When ln(PIIINP) or TIMP-1 were combined with APRI, the combined AUROCs could distinguish F2/F3 from F0/F1, but without significantly higher accuracy compared with APRI alone. APRI could also distinguish patients with simple steatosis from nonalcoholic steatohepatitis, and those with from those without lobular inflammation and ballooning, findings warranting further research. In conclusions: The application of ELF test and APRI can distinguish F0/F1 from F2/F3 fibrosis stages in NAFLD patients.

Detail experimental measurements of a 2.4 GHz printed dipole antenna for wireless communication systems is presented and discussed. A group of printed dipoles with integrated balun have been designed and constructed on a dielectric substrate. This paper is based on modifications of the known printed dipole architecture. The corresponding printed dipole antennas have differences on their forms that are provided by two essential geometry parameters. The first parameter l is related to the bend on microstrip line that feeds the dipole and the second w corresponds to the form of the dipole’s gap. The impact of these parameters on reflection coefficient and radiation pattern of antenna has been investigated. The corresponding measured results indicate that the return loss and radiation pattern of a printed dipole antenna are independent of the w parameter. Instead, variations in the value of the l parameter in the dipole’s structure affect the form of the corresponding return loss. These observations are very important and provide interesting considerations on affecting design and construction of antenna elements at frequency range of 2.4 GHz.

The constantly increasing demand for capacity in modern communication systems such as wireless backhaul has led to the employment of frequencies above 10 GHz where the dominant fading mechanism is rain attenuation which is usually modelled as a lognormal random variable (when expressed in dB - log-lognormal in linear scale). In addition, in the context of green communications the use of cooperative diversity techniques can be considered as an important tool which improves the performance, reliability and efficiency of such systems. In this paper, the outage performance analysis of a cooperative system operating at frequencies above 10 GHz is presented, where the propagation medium consists of spatially correlated fading channels. In addition, the energy and spectral efficiency of various multiple-access protocols as well as different relay retransmission and receiver combining techniques are investigated. Moreover, it is proposed that the high correlation coefficient between various rain fading channels can be exploited by the relay to estimate the rain fading of the next hop. Extended numerical results present the impact of various system parameters on the end-to-end performance. Finally, comparison with an energy- and bandwidth- equivalent direct link highlights the system parameter regions where cooperative diversity offers gains over non-cooperation.

A Reply to the Comment by Michael C. Birse, Xiangdong Ji, and Judith A. McGovern.Received 9 January 2001DOI:https://doi.org/10.1103/PhysRevLett.86.3205©2001 American Physical Society

UWB communications have attracted considerable interest, targeting applications in high‐speed data transfer wireless communication systems. This paper studies the effects of matched filter receiver in the performance of such a system. Such effects are evaluated in terms of the Bit Error Rate (BER) for a Binary Pulse Position Modulation (BPPM) scheme, considering multipath propagation channel and the presence of noise. The case of imperfect channel estimation is taken into account. Dependence of BER on parameters such as signal to noise ratio, number of estimation pulses and correletor taps is also presented.

Exact expressions for the probabilities P(l,m-l/k) of l correct packet receptions and m-l erroneous ones, out of total k packets contending in a slot, are presented for the case of frequency-hopped spread-spectrum random-access slotted networks employing random frequency hopping patterns. These expressions are difficult to evaluate numerically for values of m>3. However, their numerical analysis indicates that under light traffic conditions these probability values are very close to the ones provided by the independent receiver operation assumption, under which the distribution of multireception obeys the binomial law.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Analysis, simulation, implementation and results of a new kiln drive system consisting of two AC motors of 315 kW each, on an existing common tooth gear, as a new contribution for the operational optimisation of rotating kilns, are presented in this study. Two separate inverter units control the two asynchronous motors with a common rectifier. This study also illustrates how backlash problems on tooth gear and maintenance needs are eliminated while reducing operational costs, down‐times and energy consumption, by applying contemporary technology, including power electronics and dynamic performance in control systems.

Service-oriented architecture can be considered as a philosophy or paradigm in organizing and utilizing services and capabilities that may be under the control of different ownership domains. Virtualization provides abstraction and isolation of lower level functionalities, enabling portability of higher level functions and sharing of physical resources. However, dynamics, environmental conditions and increasing complexity / heterogeneity of underlying resources call for adaptive resource handling. In this view an intelligent distributed architecture that enables dynamic user management and control on network-wide resource sharing by using the service oriented architecture concept is presented. Additionally, the proposed architecture supports trading of resources that will enable the transformation of traditional business models.

This paper describes the design and implementation of an UWB Impulse Radio transmitter. This UWB transmitter produces very short pulses with possibility of time‐shifting to be used in cases of Pulse Position Modulation (PPM). The transmitter, which is based on step recovery diode (SRD), can operate at 50 Mbps with high repetition rate. Experimental results show that, ultra short pulses with duration of about 1nsec and spectrum exceeding 2 GHz at −10 dB, are produced and transmitted.

This paper presents a novel method of JPEG image Steganalysis, driven by the need for a quick and accurate identification of stego-carriers from a collection of files, where there is no knowledge of the steganography algorithm used, nor previous database of suspect carrier files created. The suspicious image is analyzed in order to identify the encoding algorithm while various meta-data is retrieved. An image file is then reconstructed in order to be used as a measure of comparison. A generalization of the basic principles of Benford’s Law distribution is applied on both the suspicious and the reconstructed image file in order to decide whether the target is a stego-carrier. The authors demonstrate the effectiveness of the technique with a steganalytic tool that can blindly detect the use of JPHide/JPseek/JPHSWin, Camouflage and Invisible Secrets. Experimental results show that the steganalysis scheme is able to efficiently detect the use of different steganography algorithms without the use of a time consuming training step, even if the embedding data rate is very low. The accuracy of the detector is independent of the payload. The method described can be generalized in order to be used for the detection of different type images which act as stego-carriers.

AIM: Feasibility and reliability evaluation of 5G internet networks (5G IN) upon Artificial Intelligence (AI)/Machine Learning (ML), of telemonitoring and mobile ultrasound (m u/s) in an ambulance car (AC)- integrated in the pre-hospital setting (PS)- to support the Golden Hour Principle (GHP) and optimize outcomes in severe trauma (TRS). MATERIAL AND METHODS: (PS) organization and care upon (5G IN) high bandwidths (10 GB/s) mobile tele-communication (mTC) experimentation by using the experimental Cobot PROMETHEUS III, pn:100016 by simulation upon six severe trauma clinical cases by ten (N1=10) experts: Four professional rescuers (n1=4), three trauma surgeons (n2=3), a radiologist (n3=1) and two information technology specialists (n4=2) to evaluate feasibility, reliability and clinical usability for instant risk, prognosis and triage computation, decision support and treatment planning by (AI)/(ML) computations in (PS) of (TRS) as well as by performing (PS) (m u/s). RESULTS: A. Trauma severity scales instant computations by the Cobot PROMETHEUS III, pn 100016) ) based on AI and ML complex algorithms and Cloud Computing, telemonitoring and r showed very high feasibility and reliability upon (5GIN) under specific, technological, training and ergonomic prerequisites B. Measured be-directional (m u/s) images data sharing between (AC) and (ED/TC) showed very high feasibility and reliability upon (5G IN) under specific, technological and ergonomic conditions in (TRS). CONCLUSION: Integration of (PS) tele-monitoring with (AI)/(ML) and (PS) (m u/s) upon (5GIN) via the Cobot PROMETHEUS III, (pn 100016) in severe (TRS/ES), seems feasible and under specific prerequisites reliable to support the (GHP) and optimize outcomes in adult and pediatric (TRS/ES).

In modern mobile communication system, low profile antennas capable of broadband operation are required. Nevertheless there is a problem in changing fast and easy the resonant frequency to achieve effective bandwidth. In this paper we examine in particular how an added capacitive load affects the resonant frequency, the VSWR and the current distribution of a Planar antenna. The resonant frequency dependence from the capacitance load is useful parameter for making full self‐tuning antennas.

Latest technologies in wireless communications present new challenges on antenna design. Reduced size antennas with self reconfigurable ability are characteristical of smart antennas. This paper presents the practical implementation issues of making an automatic smart antenna tuning system varying the resonant frequency of the antenna using a varactor. The primary parameter for changing varactor’s value is antenna’s VSWR which is monitored by a uC. Additionally, the uC also controls the varactor’s value.

Several well‐known computational methods, based on various mathematical concepts, are applied to the electromagnetic scattering analysis of a benchmark cavity structure. Specifically, a simplified jet engine inlet configuration is defined, constructed and used as reference, whereas predicted numerical results for the radar cross‐section are compared with measurements. The merits and drawbacks of each method are highlighted and quantified, with respect to accuracy, efficiency, resource requirements, reliability and robustness. Conclusions may be exploited in the near future in the construction of reliable classifiers, used in non‐cooperative target identification.

Multiple—output transmitter implementation based on Direct Digital Synthesis (DDS) architecture is presented and investigated. A particular number of identical and independent units compose the proposed device. DDS technology is applied on the first stage of these units and provides amplitude, phase and frequency adjustments on the corresponding output signals. Quadrature mixers are driven by DDS’s outputs and corresponding amplification and filtering circuits are also used to prepare the radiofrequency signals in the outputs of the proposed device. Design issues of analog circuitry and digital control logic are also described. Phase, amplitude and frequency accuracy that DDS technology provides are further discussed. Experimental results indicate that the proposed transmitter architecture can provide independent RF signals for wireless applications.

Ceratonia siliqua L., Myrtus communis L., Nerium oleander L., Rosmarinus officinalis L., Ligustrum japonicum Thunb. and Pittosporum tobira (Thunb.) Aiton were grown in long tubes as well in rhizotrons. After a period of acclimation to the conditions of the experimental construction under normal watering conditions, some plants were watered whereas other plants remained unwatered for a period of one month. During the studying period the plants have been observed and regular measurements of roots and above ground parts development were taken. The results show the resistance of the Mediterranean plants (C. siliqua, M. communis, N. oleander) to water deficit in comparison to plants that are often used in parks and urban horticulture (L. japonicum, P. tobira), whereas R. officinalis shows an intermediate stage of endurance to drought.