Solving Weighted Least Squares (WLS) problems on ARM-based architectures

TheWeighted Least Squares algorithm (WLS) is applied to numerous optimization problems, but requires the use of high computational resources, especially when complex arithmetic is involved. This work aims to accelerate the resolution of a WLS problem by reducing the computational cost (relaying on BLAS/LAPACK routines) and the computational precision from double to single. As a test case, we design an IIR filter for a Graphic Equalizer, where the numerical errors due to single precision are easily visualized. In addition, given the importance of low power architectures for this kind of implementations, we evaluate the performance, scalability, and energy efficiency of each method on two different processors implementing the ARMv7 architecture, widely used in current mobile devices with power constraints. Results show that the method that exhibits a high theoretical computational cost overcomes in efficiency other methods with lower theoretical cost in architectures of this type.This work started in spring 2016 when Jose A. Belloch was a visiting postdoctoral researcher at Budapest University of Technology and Economics thanks to the European Network COST Action IC1305 inside the program Short Term Scientific Mission with the following reference: COST-SPASM-ECOST-STSM-IC1305-020416-072431. Dr. Jose A. Belloch is supported by GVA contract APOSTD/2016/069. The researchers from Universitat Jaume I are supported by the CICYT projects TIN2014-53495-R of MINECO and FEDER. The authors from the Universitat Politecnica de Valencia are supported by MINECO Projects TEC2015-67387-C4-1-R, PROMETEOII/2014/003 and CAPAP-H5 network TIN2014-53522-REDT. The researcher from UCM is supported by the EU (FEDER) and the Spanish MINECO, under Grants TIN 2015-65277-R and TIN2012-32180. The work of Balazs Bank was supported by the UNKP-16-4-III New National Excellence Program of the Ministry of Human Capacities, Hungary.Belloch Rodríguez, JA.; Bank, B.; Igual Peña, FD.; Quintana Ortí, ES.; Vidal Maciá, AM. (2017). Solving Weighted Least Squares (WLS) problems on ARM-based architectures. Journal of Supercomputing. 73(1):530-542. https://doi.org/10.1007/s11227-016-1910-9S530542731Smith TM, van de Geijn RA, Smelyanskiy M, Hammond JR, Van Zee FG (2014) Anatomy of high-performance many-threaded matrix multiplication. In: 28th IEEE International Parallel and Distributed Processing Symposium (IPDPS 2014)Burrus CS (2012) Iterative reweighted least squares. OpenStax-CNC document, May 2012, module m45285. http://cnx.org/content/m45285/1.12 . Accessed 2 Nov 2016Khang SW (1972) Best $$L_p$$ L p approximation. Math Comput 26(118):505–508Jackson LB (2008) Frequency-domain Steiglitz-McBride method for least-squares filter design, ARMA modeling, and periodogram smoothing. IEEE Signal Process Lett 15:49–52Bank B (2012) Magnitude-priority filter design for audio applications. In: Proceedings of $$132^{{\rm nd}}$$ 132 nd AES Convention, Preprint No. 8591, Budapest, Hungary, May 2012Daubechies I, Devire R, Fornasier M, Gntrk CS (2010) Iteratively reweighted least squares minimization for sparse recovery. Comput Music J 23(2):52–69Rämö J, Välimäki V, Bank B (2014) High-precision parallel graphic equalizer. IEEE/ACM Trans Audio Speech Lange Proc 22(12):1894–1904Perez Gonzales E, Reiss J (2009) Automatic equalization of multi-channel audio using cross-adaptive methods. In: Proceedings of AES 127th Convention, New York, Oct. 2009Rämö J, Välimäki V (2013) Live sound equalization and attenuation with a headset. In: Proceedings of AES 51st International Conference, Helsinki, Finland, Aug. 2013Mäkivirta A, Antsalo P, Karjalainen M, Välimäki V (2003) Modal equalization of loudspeaker-room responses at low frequencies. J Audio Eng Soc 51(5):324–343Holters M, Zölzer U (2006) Graphic equalizer design using higher-order recursive filters. In: Proceedings of International Conference Digital Audio Effects, Montreal, QC, pp 37–40Tassart S (2013) Graphical equalization using interpolated filter banks. J Audio Eng Soc 61(5):263–279Chen Z, Geng GS, Yin FL, Hao J (2014) A pre-distortion based design method for digital audio graphic equalizer. Digital Signal Process 25:296–302Välimäki V, Reiss J (2016) All about audio equalization: solutions and frontiers. Appl Sci 6(5):129–145Belloch JA, Välimäki V (2016) Efficient target-response interpolation for a graphic equalizer. In: 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), March 2016, pp 564–568Belloch JA, Alventosa FJ, Alonso P, Quintana-Ortí ES, Vidal AM (2016) Accelerating multi-channel filtering of audio signal on arm processors. J Supercomput, pp 1–12. doi: 10.1007/s11227-016-1689-8Belloch JA, Gonzalez A, Igual FD, Mayo R, Quintana-Ortí ES (2015)Vectorization of binaural sound virtualization on the ARM cortex-A15 architecture. In: Proceedings of 23rd European Signal Processing Conference, (EUSIPCO), Nize, France, September 2015Mitra G, Johnston B, Rendell A, McCreath E, Zhou J (2013) Use of simd vector operations to accelerate application code performance on low-powered arm and intel platforms. In: IEEE 27th International Parallel and Distributed Processing Symposium Workshops PhD Forum (IPDPSW), May 2013, pp 1107–1116Tomov S, Dongarra J, Baboulin M (2008) Towards dense linear algebra for hybrid gpu accelerated manycore systems. LAPACK Working Note, Tech. Rep. 210, Oct. 2008. http://www.netlib.org/lapack/lawnspdf/lawn210.pdf . Accessed 2 Nov 2016Dongarra JJ, DuCroz J, Hammarling S, Hanson RJ (1985) A proposal for an extended set of fortran basic linear algebra subprograms. ACM Signum Newsletter, New York, pp 2–18Golub GH, Loan CFV (2013) Matrix Comput, 4th edn. The John Hopkins University Press, BaltimoreAlonso P, Badia RM, Labarta J, Barreda M, Dolz MF, Mayo R, Quintana-Ortí ES, Reyes R (2012) Tools for power-energy modelling and analysis of parallel scientific applications. In: 41st International Conference on Parallel Processing—ICPP, 2012, pp 420–42

Guillain-Barré syndrome associated with Puumula Hantavirus infection.

We report the case of a 62-year-old man who developed Guillain-Barré syndrome (GBS) following Hantavirus infection. Only three similar cases have been described in the literature so far. GBS is an autoimmune disease characterized by progressive symmetrical weakness of lower limbs extending to upper limbs and face and low or absent tendon reflexes. Prompt diagnosis is mandatory as GBS is a potentially life threatening disorder and needs timely treatment to ensure fast recovery and fewer complications

Dissection d'un anévrysme de l'artère rénale chez une femme enceinte atteinte de maladie Elhers-Danlos de type IV.

[Dissection of renal artery aneurysm in a pregnant woman with Elhers-Danlos disease type IV]. Recall the clinical signs and personal and family medical history suggestive of Elhers-Danlos syndrome, mainly type IV. Review of literature and presentation of a clinical case observed in a female patient with Elhers-Danlos disease type IV who developed dissection of a renal artery during pregnancy. The prevalence of the syndrome is increasing, reaching, according to the latest publications 1/5,000 births. It is important to determine the type of syndrome to assess prognosis. In the classic type and in the hyper mobile type, pregnancy is generally well tolerated although certain complications linked to connective tissue dysfunction such as pelvic instability, premature delivery, bleeding postpartum and perineal lacerations, may develop. Ehlers-Danlos syndrome can be associated with serious and even fatal complications for these patients: vascular dissection or uterine rupture. It is important for obstetricians to be aware of the clinical signs and symptoms suggestive of Elhers-Danlos syndrome in a pregnant patient and to know the diagnostic possibilities and potential risks. If a typeIV syndrome is diagnosed, it is very important to inform the patient about the potential implications for pregnancy and maternal health, as well as the risk of transmission to the child and the possibility of antenatal diagnosis.L’objectif était de permettre aux gynécologues obstétriciens d’être attentif aux signes cliniques et aux antécédents personnels et familiaux qui peuvent révéler la présence d’un syndrome d’Elhers-Danlos, essentiellement de type IV. Revue de la littérature et présentation du cas clinique d’une patiente enceinte atteinte d’Elhers-Danlos de type IV présentant une dissection de l’artère rénale au décours de sa grossesse. La prévalence de ce syndrome est en augmentation suite à de récents articles, il est de 1/5 000 naissances. Le typage de ce syndrome est important pour pouvoir évaluer le pronostic. Dans le type classique et le type hyper mobile, la grossesse est généralement bien tolérée mais il existe des complications liées aux dysfonctions des tissus conjonctifs telles que l’instabilité pelvienne, l’accouchement prématuré, l’hémorragie du post-partum et lacérations périnéales. Le syndrome d’Elhers-Danlos de type IV peut être associé à des complications sévères, voire mortelles chez ces patientes, de type rupture vasculaire ou utérine. Il est important que les obstétriciens soient attirés par les signes et les symptômes cliniques qui peuvent indiquer la présence d’un EDS chez une patiente enceinte et connaissent les possibilités diagnostiques et les risques potentiels. La connaissance du syndrome de type IV est très important afin d’informer la patiente des implications d’une grossesse sur sa propre santé, sur le risque de transmission à son enfant et la possibilité d’un diagnostic prénatal

[Submandibular sialadenitis secondary to iodinated contrast injection] : Sialadénite submandibulaire secondaire à une injection de produit de contraste iodé

ERMAInternational audienc

Microstructure and electrical resistance evolution during sintering of a Ag nanoparticle paste

Silver nanoparticle pastes are promising materials for high temperature interconnection particularly above 400 °C. Reliability is a major concern in interconnection and it mainly depends on the behavior under the stress induced by thermal cycling. The joint microstructure is then a crucial parameter for reliability and determines the electrical, mechanical and thermal properties. Here, an investigation procedure is proposed to describe the microstructure of a joint and to monitor its evolution in real-time during the sintering. Combining electron and x-ray diffraction with electrical resistance measurement and secondary ion mass spectroscopy, our method is used on a sample made out of a home-made silver nanoparticle paste. The influence of the chemical composition of the paste on the microstructure is discussed as well as the compatibility of the paste for oxide interconnection. © 2015 IOP Publishing Ltd

Caractère « porteur de la flavescence dorée » chez les vignes porte-greffes, en particulier le 3309 Couderc et le Fercal

La plupart des variétés de porte-greffes de vigne peuvent être porteuses sans symptôme de la flavescence dorée (FD). Ces ceps infectés peuvent être reconnus, dans une certaine mesure, chez le 3309 C et le Fercal, par un retard printanier de végétation et le mauvais aoûtement de certains rameaux. Une fois infectés, il apparaît que ces ceps restent porteurs toute leur vie. Par conséquent, au contraire de ce qui se passe pour les variétés de V vinifera, les traitements aux insecticides pour éviter les inoculations par l'insecte vecteur ne sont pas efficaces pour réduire l'infectivité des plantes déjà infectées. Ces porte-greffes ne transmettent la maladie que dans une proportion de leurs boutures variant de 6 à 80 % selon les ceps. Les rameaux d'un même cep sont inégalement infectés et le niveau d'infection, le long du rameau, apparaît fortuit. La forte transmission de la FD par les boutures infectées de 3309 C est associée à une forte mortalité des greffes, la « mortalité pratique» (greffes mortes + malades) pouvant atteindre 82%. De nouvelles inoculations décelées dans un champ de pieds mères traité aux insecticides soulignent la nécessité d'un bon isolement géographique des vignes mères.Ability of grapevine rootstocks varieties to transmit flavescence dorée. Study of the case of 3309 C and Fercal. Most grapevine rootstock varieties are potential symptomless carriers of Flavescence dorée (FD). However some infected plants of 3309 C and Fercal rootstocks can be recognized as they exhibit late spring growth and incomplete ripening of some canes. Once infected, these plants remain as potential sources of infection throughout their lifetime. Therefore, contrary to V vinifera behaviour, treating fields with insecticides against the leafhopper vector to prevent inoculations of the disease is not efficient in reducing the infectivity of the plants already infected. Only 6-80% of cuttings obtained from infected plants transmit the disease. Canes from the same vine are unevenly infected and the infection level along the canes is also uneven. The high degree of FD transmission in 3309 C is associated with a high graft mortality, the 'practical mortality' (graft death + diseased) sometimes reaching 82%. New inoculations can occur in fields containing 3309 mother plants, even though insecticide treatments are mandatory. This stresses the necessity of a geographical isolation of mother-plant stands

Infraorbital nerve schwannoma : [Schwannome du nerf infra-orbitaire]

ERMAInternational audienc

Microstructure and electrical resistance evolution during sintering of a Ag nanoparticle paste

International audienceSilver nanoparticle pastes are promising materials for high temperature interconnection particularly above 400 °C. Reliability is a major concern in interconnection and it mainly depends on the behavior under the stress induced by thermal cycling. The joint microstructure is then a crucial parameter for reliability and determines the electrical, mechanical and thermal properties. Here, an investigation procedure is proposed to describe the microstructure of a joint and to monitor its evolution in real-time during the sintering. Combining electron and x-ray diffraction with electrical resistance measurement and secondary ion mass spectroscopy, our method is used on a sample made out of a home-made silver nanoparticle paste. The influence of the chemical composition of the paste on the microstructure is discussed as well as the compatibility of the paste for oxide interconnection. © 2015 IOP Publishing Ltd