26 research outputs found
Silicon detectors for gamma-ray and beta spectroscopy
No full textLarge active volume Si(Li) detectors were successfully developed for gamma-ray spectrometry at room temperature that show a sufficient efficiency and an energy resolution that is better than scintillation detectors. The higher efficiency of the proposed detectors with respect to normal silicon diodes is achieved by increasing the active volume. For this purpose special attention is given to the selection of the initial material which has to show homogeneous electrophysical parameters, low concentration of oxygen impurities and high structural perfection. The technique of using lithium ions is used as these drift into large depths and hence the profile of the impurity distribution is optimized
Hypoxic-hypercapnic training-based correction of functional state of qualified athletes
No full textObjective of the study was to substantiate the need for a differentiated approach to the correction of the functional state of qualified athletes using hypoxic-hypercapnic training. Methods and structure of the study. The study was carried out at the premises of the state-financed institution "Sports Medicine Center", Crimea, in the period from 2015 to 2017, with the informed consent of the subjects and after the verdict of the ethics committee. Sampled for the study were the 19-22 year-old qualified athletes from team sports (n=100) and combat athletes (n=100). The authors rated their cardiorespiratory system functionality in the transitional period of the one-year training cycle, which was followed by the hypoxic-hypercapnic training course for 83 athletes. The course consisted of 10 training sessions, each with three sets of 5, 6, and 7 minutes (18 minutes in total), respectively, with a 5-minute rest break inbetween. Results and conclusions. When identifying the differences in the functional reserves of the myocardium, it was the T-wave symmetry rates (βT) that were the most informative. There were statistically significant relationships between MOC/kg and PЕТ CO2 in the combat athletes with all breathing patterns. After the hypoxic-hypercapnic training course, the athletes with the initial hypocapnic type of ventilation were found to have expanded myocardial reserve and increased aerobic capacity of the body. The βT value decreased by 6% (p˂0.001), the MOC/ kg value increased by 10% (p˂0.01). In the group with the initial hypocapnic type of ventilation, no changes in MOC/kg were found, but the βT value decreased by 10% (p˂0.001)
Automatic Tuning to Performance Modelling of Matrix Polynomials on Multicore and Multi-GPU Systems
No full text[EN] Automatic tuning methodologies have been used in the design of routines in recent years. The goal of these methodologies is to develop routines which automatically adapt to the conditions of the underlying computational system so that efficient executions are obtained independently of the end- user experience. This paper aims to explore programming routines that can automatically be adapted to the computational system conditions thanks to these automatic tuning methodologies. In particular, we have worked on the evaluation of matrix polynomials on multicore and multi-GPU systems as a target application. This application is very useful for the computation of matrix functions like the sine or cosine but, at the same time, the application is very time consuming since the basic computational kernel, which is the matrix multiplication, is carried out many times. The use of all available resources within a node in an easy and efficient way is crucial for the end user.This work has been partially supported by Generalitat Valenciana under Grant PROM-ETEOII/2014/003, and by the Spanish MINECO, as well as European Commission FEDER funds, under Grant TEC2015-67387-C4-1-R and TIN2015-66972-C5-3-R, and network CAPAP-H. Also, we have work in cooperation with the EU-COST Programme Action IC1305, "Network for Sustainable Ultrascale Computing (NESUS)".Boratto, M.; Alonso-Jordá, P.; Gimenez, D.; Lastovetsky, A. (2017). Automatic Tuning to Performance Modelling of Matrix Polynomials on Multicore and Multi-GPU Systems. The Journal of Supercomputing. 73(1):227-239. https://doi.org/10.1007/s11227-016-1694-yS227239731Alberti PV, Alonso P, Vidal AM, Cuenca J, Giménez D (2004) Designing polylibraries to speed up linear algebra computations. IJHPCN 1(1/2/3):75–84Alonso P, Boratto M, Pinilla J, Ibañez J, Martinez J (2014) On the evaluation of matrix polynomials using several GPGPUs. Tech Rep Riunet/E10251/39615Anderson E, Bai Z, Bischof C, Demmel J, Dongarra J, Croz JD, Greenbaum A, Hammarling S, McKenney A, Ostrouchov S, Sorensen D (2013) LAPACK users guide, 2nd edn. SIAM, PhiladelphiaBlackford LS, Demmel J, Dongarra J, Duff I, Hammarling S, Henry G, Heroux M, Kaufman L, Lumsdaine A, Petitet A, Pozo R, Remington K, Whaley RC (2001) An updated set of basic linear algebra subprograms (blas). ACM Trans Math Softw 28:135–151Caron E, Uter F (2002) Parallel extension of a dynamic performance forecasting tool. Sci Ann Cuza Univ 11:80–93Chandra R (2001) Parallel programming in OpenMP. Morgan Kaufmann, BurlingtonDemmel J, Marques O, Parlett BN, Vömel C (2008) Performance and accuracy of LAPACK’s symmetric tridiagonal eigensolvers. SIAM J.Sci Comput 30(3):1508–1526Frigo M, Johnson S (1998) FFTW: an adaptive software architecture for the FFT. In: Proceedings of IEEE International Conference on Acoustics Speech and Signal Processing vol. 3, pp 1381–1384García L, Cuenca J, Giménez D (2007) Including improvement of the execution time in a software architecture of libraries with self-optimisation. In: ICSOFT 2007, Proceedings of the Second International Conference on Software and Data Technologies, Volume SE, Barcelona, Spain, pp 156–161, 22–25 JulyGarcía LP, Cuenca J, Giménez D (2014) On optimization techniques for the matrix multiplication on hybrid cpu+gpu platforms. Ann Multicore GPU Program 1(1):10–18Hasanov K, Quintin JN, Lastovetsky A (2014) Hierarchical approach to optimization of parallel matrix multiplication on large-scale platforms. J Supercomput 71(11):24–34Katagiri T, Kise K, Honda H (2005) RAO-SS: a prototype of run-time auto-tuning facility for sparse direct solvers. Tech Rep 22(1):1–10Katagiri T, Kise K, Honda H, Yuba T (2004) Effect of auto-tuning with user’s knowledge for numerical software. Proceedings of the 1st conference on computing frontiers, Ischia, Italy. ACM, New York, NY, USA, pp 12–25Nath R, Tomov S, Dongarra J (2010) An improved magma gemm for fermi graphics processing units. Int J High Perform Comput Appl 24(4):511–515Paterson MS, Stockmeyer LJ (1973) On the number of nonscalar multiplications necessary to evaluate polynomials. SIAM J Comput 2(1):60–66PLASMA (2015) Parallel linear algebra software for multicore architectures. Available in: http://www.netlib.org/plasma/ . Accessed 1 June 2015Tanaka T, Katagiri T, Yuba T (2007) D-spline based incremental parameter estimation in automatic performance tuning. In: International Conference on Applied Parallel Computing: State of the Art in Scientific Computing, PARA’06. Springer-Verlag, Berlin, Heidelberg, pp 986–995Vuduc R, Demmel J, Bilmes J (2004) Statistical models for empirical search-based performance tuning. Int J High Perform Comput Appl 18:65–94Whaley RC, Petitet A, Dongarra JJ (2001) Automated empirical optimizations of software and the ATLAS project. Parallel Comput 27:21–3
Radiation hardness of silicon detectors based on pre-irradiated silicon
No full textRadiation hardness of planar detectors processed from pre-irradiated and thermo-annealed n-type FZ silicon substrates, and standard FZ as a reference, was studied. The high purity n-Si wafers with carrier concentration 4.8x1011 cm-3 were pre-irradiated in Kiev’s nuclear research reactor by fast neutrons to fluence of about 1016 neutrons/cm2 and thermo-annealed at a temperature of about 850 1C. Silicon diodes were fabricated from standard and pre-irradiated silicon substrates by IRST (Italy). All diodes were subsequently irradiated by fast neutrons at Kiev and Ljubljana nuclear reactors. The dependence of the effective doping concentration as a function of fluence (Neff = f(F)) was measured for reference and pre-irradiated diodes. Pre-irradiation of silicon improves the radiation hardness by decreasing the acceptor introduction rate (b), thus mitigating the depletion voltage (Vdep) increase. In particular, b in reference samples is about 0.017 cm-1, and for pre-irradiated samples is about 0.008 cm-1. Therefore, the method of preliminary irradiation can be useful to increase the radiation hardness of silicon devices to be used as sensors or detectors in harsh radiation environments
Study of Neutron Pre-Irradiated Silicon for Nuclear Detectors
No full textThe ways of increasing the radiation hardness of silicon were considered. It was then experimentally shown that a preliminary irradiation of the bulk silicon introduces sinks for radiation defects that leads to an increased radiation hardness of the silicon. Neutron transmutation doping of silicon can be considered as one form of preliminary radiation. It was shown that for neutron transmutated silicon the carrier removal rate in NTD after γ-irradiation is more than one order of magnitude smaller than in a standard reference specimen, but the carriers removal rate after neutron irradiation is approximately a factor of two less
A dataflow IR for memory efficient RIPL compilation to FPGAs
No full textField programmable gate arrays (FPGAs) are fundamentally different to fixed processors architectures because their memory hierarchies can be tailored to the needs of an algorithm. FPGA compilers for high level languages are not hindered by fixed memory hierarchies. The constraint when compiling to FPGAs is the availability of resources.
In this paper we describe how the dataflow intermediary of our declarative FPGA image processing DSL called RIPL (Rathlin Image Processing Language) enables us to constrain memory. We use five benchmarks to demonstrate that memory use with RIPL is comparable to the Vivado HLS OpenCV library without the need for language pragmas to guide hardware synthesis. The benchmarks also show that RIPL is more expressive than the Darkroom FPGA image processing language
Bacterial endosymbionts influence host sexuality and reveal reproductive genes of early divergent fungi
No full textMany heritable mutualisms, in which beneficial symbionts are transmitted vertically between host generations, originate as antagonisms with parasite dispersal constrained by the host. Only after the parasite gains control over its transmission is the symbiosis expected to transition from antagonism to mutualism. Here, we explore this prediction in the mutualism between the fungus Rhizopus microsporus (Rm, Mucoromycotina) and a beta-proteobacterium Burkholderia, which controls host asexual reproduction. We show that reproductive addiction of Rm to endobacteria extends to mating, and is mediated by the symbiont gaining transcriptional control of the fungal ras2 gene, which encodes a GTPase central to fungal reproductive development. We also discover candidate G-protein-coupled receptors for the perception of trisporic acids, mating pheromones unique to Mucoromycotina. Our results demonstrate that regulating host asexual proliferation and modifying its sexual reproduction are sufficient for the symbiont's control of its own transmission, needed for antagonism-to-mutualism transition in heritable symbioses. These properties establish the Rm-Burkholderia symbiosis as a powerful system for identifying reproductive genes in Mucoromycotina.National Science FoundationNational Institutes of HealthOffice of Science of the U.S. Department of Energ
Mathematical analysis of the stability of heart-rate dynamics in postinfarction patients
No full textDevelopment of radiation tolerant semiconductor detectors for the Super-LHC.
No full textThe envisaged upgrade of the Large Hadron Collider (LHC) at CERN towards the Super-LHC (SLHC) with a 10 times increased luminosity of 1035 cm−2 s−1 will present severe challenges for the tracking detectors of the SLHC experiments. Unprecedented high radiation levels and track densities and a reduced bunch crossing time in the order of 10 ns as well as the need for cost effective detectors have called for an intensive R&D program. The CERN RD50 collaboration “Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders” is working on the development of semiconductor sensors matching the requirements of the SLHC. Sensors based on defect engineered silicon like Czochralski, epitaxial and oxygen enriched silicon have been developed. With 3D, Semi-3D and thin detectors new detector concepts have been evaluated and a study on the use of standard and oxygen enriched p-type silicon detectors revealed a promising approach for radiation tolerant cost effective devices. These and other most recent advancements of the RD50 collaboration are presented
