Fast consensus via predictive pinning control

By incorporating some predictive mechanism into a few pinning nodes, we show that convergence procedure to consensus can be substantially accelerated in networks of interconnected dynamic agents while physically maintaining the network topology. Such an acceleration stems from the compression mechanism of the eigenspectrum of the state matrix conferred by the predictive mechanism. This study provides a technical basis for the roles of some predictive mechanisms in widely-spread biological swarms, flocks, and consensus networks. From the engineering application point of view, inclusion of an efficient predictive mechanism allows for a significant increase in the convergence speed towards consensus. © 2011 IEEE.published_or_final_versio

Effects of film thickness and mismatch strains on magnetoelectric coupling in vertical heteroepitaxial nanocomposite thin films

The phase field model is adopted to study the magnetoelectric coupling effects in vertical heteroepitaxial nanocomposite thin films. Both the lateral epitaxial strains between the film and the substrate and the vertical epitaxial strains between the ferroelectric and ferromagnetic phases are accounted for in the model devised. The effects of the film thickness on the magnetic-field- induced electric polarization (MIEP) are investigated. The results obtained show that the MIEP is strongly dependent on the film thickness, as well as on the vertical and lateral epitaxial strains. © 2011 American Institute of Physics.published_or_final_versio

Estimation of optical power and heat-dissipation coefficient for the photo-electro-thermal theory for LED systems

With the use of wall-plug efficiency, estimation techniques for the optical power and heat-dissipation coefficient of LEDs are introduced in this paper to enrich the photo-electro-thermal theory, which has provided a framework for analyzing LED systems. The estimation methods consist of simple procedures for optical and electrical power measurements, which are easy for LED device manufacturers and system designers to follow. The extended theory has been tested with several types of LED devices, with reasonably good agreements between theoretical and practical results. © 2011 IEEE.published_or_final_versio

Reduced Ambiguity Calibration for LOFAR

Interferometric calibration always yields non unique solutions. It is therefore essential to remove these ambiguities before the solutions could be used in any further modeling of the sky, the instrument or propagation effects such as the ionosphere. We present a method for LOFAR calibration which does not yield a unitary ambiguity, especially under ionospheric distortions. We also present exact ambiguities we get in our solutions, in closed form. Casting this as an optimization problem, we also present conditions for this approach to work. The proposed method enables us to use the solutions obtained via calibration for further modeling of instrumental and propagation effects. We provide extensive simulation results on the performance of our method. Moreover, we also give cases where due to degeneracy, this method fails to perform as expected and in such cases, we suggest exploiting diversity in time, space and frequency.Comment: Draft version. Final version published on 10 April 201

Multi-realization of nonlinear systems

The system multi-realization problem is to find a state-variable realization for a set of systems, sharing as many parameters as possible. A multi-realization can be used to efficiently implement a multi-controller architecture for Multiple Model Adaptive Control (MMAC). We extend the linear multi-realization problem to nonlinear systems. The problem of minimal multi-realization of a set of MIMO systems is introduced and solved for feedback linearizable systems. ©2009 IEEE

Boccia court analysis for promoting elderly physical activity

Physical inactivity is one of the leading risk factors for global mortality. Older adults, in particular, are more probable to suffer the consequences of physical inactivity, since it is one of the most sedentary age groups. On the other hand, engaging physical activity can have various benefits for the prevention of several diseases and functional loss prevention, therefore, it is critical to encourage its regular practice amongst the elderly. Boccia is a simple precision ball sport that is easily adaptable for individuals with physical limitations, which makes it a perfectly good game for this circumstance. The present paper proposes a ball-detection based system for monitoring the Boccia court, compute the current game score and display it on a user interface. The future goal of such system will be to motivate the elders to participate more frequently in the Boccia game and make the overall game experience more enjoyable. The proposed system was tested with twenty video recordings of different simulated game situations. Overall, the obtained results were encouraging, having only one incorrect game score being computed by the developed algorithm.This article is a result of the project Deus ex Machina: NORTE01-0145-FEDER-000026, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF)

Terahertz metamaterials on flexible polypropylene substrate

The final publication is available at Springer via http://dx.doi.org/10.1007/s11468-014-9724-1In this work, we present a metamaterial working at terahertz frequencies made over a flexible polypropylene sub-strate. The experimental measurements, in accordance with the numerical calculations, show the metamaterial reliance on the impinging electric field polarization. The structure s symmetry yields purely electrical resonant responses eliminating bianisotropy effects. The widely used bendable polypropylene polymer may promote the insertion of metamaterial-based structures with special electromagnetic response in a number of objects of our daily lives such as textiles, automotive components, and sensingThis work was supported by the Spanish MICINN under contracts CONSOLIDER EMET CSD2008-00066 and TEC2011-28664-C02-02 and by the Universitat Politecnica de Valencia under the program INNOVA 2011.Ortuño Molinero, R.; García Meca, C.; Martínez Abietar, AJ. (2014). Terahertz metamaterials on flexible polypropylene substrate. Plasmonics. 9(5):1143-1147. https://doi.org/10.1007/s11468-014-9724-1S1143114795Smith DR, Padilla WJ, Vier DC, Nemat-Nasser SC, Schultz S (2000) Composite medium with simultaneously negative permeability and permittivity. Phys Rev Lett 84:4184–4187Pendry JB (2000) Negative refraction makes a perfect lens. Phys Rev Lett 85:3966–3969Zhang X, Liu Z (2008) Superlenses to overcome the diffraction limit. Nat Mater 7:435–441Pendry JB, Schurig D, Smith DR (2006) Controlling electromagnetic fields. Science 312:1780–1782Schurig D, Mock JJ, Justice BJ, Cummer SA, Pendry JB, Starr AF, Smith DR (2006) Metamaterial electromagnetic cloak at microwave frequencies. Science 314:977–980Rodríguez-Cantó PJ, Martínez-Marco M, Rodríguez-Fortuño FJ, Tomás-Navarro B, Ortuño R, Peransí-Llopis S, Martínez A (2011) Demonstration of near infrared gas sensing using gold nanodisks on functionalized silicon. Opt Express 19:7664–7672Rodríguez-Fortuño FJ, Martínez-Marco M, Tomás-Navarro B, Ortuño R, Martí J, Martínez A, Rodríguez-Cantó PJ (2011) Highly-sensitive chemical detection in the infrared regime using plasmonic gold nanocrosses. Appl Phys Lett 98:133118O’Hara FJ, Singh R, Brener I, Smirnova E, Han J, Taylor AJ, Zhang W (2008) Thin-film sensing with planar terahertz metamaterials: sensitivity and limitations. Opt Express 16:1786–1795Tao H, Landy NI, Bingham CM, Zhang X, Averitt RD, Padilla WJ (2008) A metamaterial absorber for the terahertz regime: design, fabrication and characterization. Opt Express 16:7181–7188Iwaszczuk K, Strikwerda AC, Fan K, Zhang X, Averitt RD, Jepsen PU (2012) Flexible metamaterial absorbers for stealth applications at terahertz frequencies. Opt Express 20:635–643Tao H, Bingham CM, Strikwerda AC, Pilon D, Shrekenhamer D, Landy NI, Fan K, Zhang X, Padilla WJ, Averitt RD (2008) Highly flexible wide angle of incidence terahertz metamaterial absorber: design, fabrication, and characterization. Phys Rev B 78:241103(R)Tao H, Bingham CM, Pilon D, Fan K, Strikwerda AC, Shrekenhamer D, Padilla WJ, Zhang X, Averitt RD (2010) A dual band terahertz metamaterial absorber. J Phys D: Appl Phys 43:225102Padilla WJ, Taylor AJ, Highstrete C, Lee M, Averitt RD (2006) Dynamical electric and magnetic metamaterial response at terahertz frequencies. Phys Rev Lett 96:107401Chen HT, Padilla WJ, Zide JMO, Gossard AC, Taylor AJ, Averitt RD (2006) Active terahertz metamaterial devices. Nature 444:597–600Chen HT, O’Hara FJ, Azad AK, Taylor AJ, Averitt RD, Shrekenhamer DB, Padilla WJ (2008) Experimental demonstration of frequency-agile terahertz metamaterials. Nature Photon 2:295–298Chen HT, Padilla WJ, Zide JMO, Bank SR, Gossard AC, Taylor AJ, Averitt RD (2007) Ultrafast optical switching of terahertz metamaterials fabricated on ErAs/GaAs nanoisland superlattices. Opt Lett 32:1620–1622Chen HT, Palit S, Tyler T, Bingham CM, Zide JMO, O’Hara FJ, Smith DR, Gossard AC, Averitt RD, Padilla WJ, Jokerst NM, Taylor AJ (2008) Hybrid metamaterials enable fast electrical modulation of freely propagating terahertz waves. Appl Phys Lett 93:091117Chen HT, Padilla WJ, Cich MJ, Azad AK, Averitt RD, Taylor AJ (2009) A metamaterial solid-state terahertz phase modulator. Nat Photon 3:148Driscoll T, Andreev GO, Basov DN, Palit S, Cho SY, Jokerst NM, Smith DR (2007) Tuned permeability in terahertz split-ring resonators for devices and sensors. Appl Phys Lett 91:062511Debus C, Bolivar PH (2007) Frequency selective surfaces for high sensitivity terahertz sensing. Appl Phys Lett 91:184102Al-Naib IAI, Jansen C, Koch M (2008) Thin-film sensing with planar asymmetric metamaterial resonators. Appl Phys Lett 93:083507Leonhardt U, Philbin TG (2010) Geometry and light: the science of invisibility. Dover, MineolaDi Falco A, Ploschner M, Krauss TF (2010) Flexible metamaterials at visible wavelengths. New J Phys 12:113006Tao H, Strikwerda AC, Fan K, Bingham CM, Padilla WJ, Zhang X, Averitt RD (2008) Terahertz metamaterials on free-standing highly-flexible polyimide substrates. Appl Phys 41:232004Tao H, Amsden JJ, Strikwerda AC, Fan K, Kaplan DL, Zhang X, Averitt RD, Omenetto FJ (2010) Metamaterial silk composites at terahertz frequencies. Adv Mater 22:3527–3531Chen ZC, Han NR, Pan ZY, Gong YD, Chong TC, Hong MH (2011) Tunable resonance enhancement of multi-layer terahertz metamaterials fabricated by parallel laser micro-lens array lithography on flexible substrates. Opt Mat Express 1:151–157Miyamaru F, Takeda MW, Taima K (2009) Characterization of terahertz metamaterials fabricated on flexible plastic films: toward fabrication of bulk metamaterials in terahertz region. Appl Phys Express 2:042001Peralta XG, Wanke MC, Arrington CL, Williams JD, Brener I, Strikwerda A, Averitt RD, Padilla WJ, Smirnova W, Taylor AJ, O’Hara FJ (2009) Large-area metamaterials on thin membranes for multilayer and curved applications at terahertz and higher frequencies. Appl Phys Lett 94:161113Choi M, Lee SH, Kim Y, Kang SB, Shin J, Kwak MH, Kang KY, Lee YH, Park N, Min B (2011) A terahertz metamaterial with unnaturally high refractive index. Nature 470:369–373Han NR, Chen ZC, Lim CS, Ng B, Hong MH (2011) Broadband multi-layer terahertz metamaterials fabrication and characterization on flexible substrates. Opt Express 19:6990–6998Aznabet M, Navarro-Cia N, Kuznetsov SA, Gelfand AV, Fedorinina NI, Goncharov YG, Beruete M, Mrabet OE, Sorolla M (2008) Polypropylene-substrate-based SRR- and CSRR- metasurfaces for submillimeter waves. Opt Express 16:18312–18319Padilla WJ, Aronsson MT, Highstrete C, Lee M, Taylor AJ, Averitt RD (2007) Electrically resonant terahertz metamaterials: theoretical and experimental investigations. Phys Rev B 75:041102(R)Chen HT, O’Hara FJ, Taylor AJ, Averitt RD, Highstrete C, Lee M, Padilla WJ (2007) Complementary planar terahertz metamaterials. Opt Express 15:1084–1095Pendry JB, Holden AJ, Robbins DJ, Stewart WJ (1999) Magnetism from conductors and enhanced nonlinear phenomena. IEEE Trans Microwave Theory Tech 47:2075–208

The Clinical Application of Anti-CCP in Rheumatoid Arthritis and Other Rheumatic Diseases

Rheumatoid arthritis (RA) is a common rheumatic disease in Caucasians and in other ethnic groups. Diagnosis is mainly based on clinical features. Before 1998, the only serological laboratory test that could contribute to the diagnosis was that for rheumatoid factor (RF). The disease activity markers for the evaluation of clinical symptoms or treatment outcome were the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). As a matter of fact, the diagnosis of early RA is quite impossible, as the clinical criteria are insufficient at the beginning stage of the disease. In 1998, Schelleken reported that a high percentage of RA patients had a specific antibody that could interact with a synthetic peptide which contained the amino acid citrulline. The high specificity (98%) for RA of this new serological marker, anti-cyclic citrullinated antibody (anti-CCP antibody), can be detected early in RA, before the typical clinical features appear. The presence or absence of this antibody can easily distinguish other rheumatic diseases from RA. Additionally, the titer of anti-CCP can be used to predict the prognosis and treatment outcome after DMARDs or biological therapy. Therefore, with improvement of sensitivity, the anti-CCP antibody will be widely used as a routine laboratory test in the clinical practice for RA

A novel osmosis membrane bioreactor-membrane distillation hybrid system for wastewater treatment and reuse

© 2016 . A novel approach was designed to simultaneously enhance nutrient removal and reduce membrane fouling for wastewater treatment using an attached growth biofilm (AGB) integrated with an osmosis membrane bioreactor (OsMBR) system for the first time. In this study, a highly charged organic compound (HEDTA3-) was employed as a novel draw solution in the AGB-OsMBR system to obtain a low reverse salt flux, maintain a healthy environment for the microorganisms. The AGB-OsMBR system achieved a stable water flux of 3.62 L/m2 h, high nutrient removal of 99% and less fouling during a 60-day operation. Furthermore, the high salinity of diluted draw solution could be effectively recovered by membrane distillation (MD) process with salt rejection of 99.7%. The diluted draw solution was re-concentrated to its initial status (56.1 mS/cm) at recovery of 9.8% after 6 h. The work demonstrated that novel multi-barrier systems could produce high quality potable water from impaired streams