Search results for "Multiplier"

Applications and numerical convergence of the partial inverse method

2006

In 1983, J.E. Spingarn introduced what he called the Partial Inverse Method in the framework of Mathematical Programming. Since his initial articles, numerous applications have been given in various fields including Lagrangian multipliers methods, location theory, convex feasibility problems, analysis of data, economic equilibrium problems. In a first part of this paper we give a survey of these applications. Then by means of optimization problems relevant to location theory such as single and multifacility minimisum or minimax location problems, we examine the main advantages of the algorithm and we point out its drawbacks mainly concerning the rate of convergence. We study how different p…

Gamma-ray position reconstruction in large lanthanum-halide crystals with SiPM readout: analytical vs. neural-network algorithms

2019

The main objective of this research was to achieve an excellent gamma-ray position reconstruction with very large monolithic scintillation crystals coupled to pixelated silicon photosensors. Analyzing the scintillation-light distribution measured along the SiPM-pixels one can get a sub-pixel accuracy for the position reconstruction. The quality of the latter depends on both the characteristics of the crystal-photosensor assembly, and the goodness of the algorithm used to reconstruct the gamma-ray hit location. We have carried out a systematic study for 511 keV gamma-rays using three different crystal thicknesses of 10 mm, 20 mm and 30 mm, all of them with planar geometry and a base size of …

Comparison among different dynamic shakedown approaches

2017

The paper concerns the search for the limit load multiplier of structures subjected to seismic actions under shakedown conditions. The search problem is treated referring to two fundamental different approaches: The unrestricted dynamic shakedown approach and a new stochastic one recently proposed. The comparison between the above cited approaches is effected with the aim of evaluate the goodness of the obtainable results and the related computational effort. The structure sensitivity with respect to shakedown is evaluated through the analysis of the shakedown limit load multiplier cumulative distribution function. This function is determined by means of the stochastic approach, adopting th…

A penalty-based interface technology

2009

Modern computers have enabled engineers to perform large scale analyses of complex structures like entire aircrafts, automobiles, and ships. One issue that arises often is the need to perform a unified analysis of a structural assembly using sub-structural models created independently. These sub-structural models are frequently designed by different engineers, thus they are likely to be incompatible at their interfaces. Finite element interface technology has been developed to facilitate the joining of independently modeled substructures. Here an effective and robust interface element is presented. This method has been developed using penalty constraints and allows computationally efficient…

Signal to Noise Ratio of Silicon Photomultipliers: a study in the Continuous Wave Regime

2014

We report on Signal to Noise Ratio measurements carried out, in the continuous wave regime, at different bias voltages, frequencies and temperatures, on a novel class of silicon photomultipliers fabricated in planar technology on silicon p-type substrate. Signal to Noise Ratio has been measured as the ratio of the photogenerated current, filtered and averaged by a lock-in amplifier, and the Root Mean Square deviation of the same current. The measured noise takes into account the shot noise, resulting from the photocurrent and the dark current. We have also performed a comparison between our SiPMs and a photomultiplier tube in terms of Signal to Noise Ratio, as a function of the temperature …

John Maurice Clark's contribution to the genesis of the multiplier analysis: A note with some related unpublished correspondence

2008

The multiplier is a central concept in Keynesian and post-Keynesian economics. It is largely what justifies activist full-employment fiscal policy: an increase in fiscal expenditures contributing to multiple rounds of spending, thereby financing itself. Yet, while a copingstone of post-Keynesian theory,

Measurements of Silicon Photomultipliers Responsivity in Continuous Wave

2012

N-on-P and P-on-N Silicon Photomultipliers: Responsivity comparison in the continuous wave regime

2013

We report on the electrical and optical comparison, in continuous wave regime, of two novel classes of silicon photomultipliers fabricated in planar technology on silicon P-type and Ntype substrate respectively. A physical explanation of the experimental results is provided.

Measurements of Silicon Photomultipliers Responsivity

2012

We present some results on the optical characterization of Silicon Photomultipliers designed for medical imaging applications. In particular we will discuss our responsivity measurements performed with very low incident optical power and on a broad spectrum

PPG/ECG Multisite Combo System Based on SiPM Technology

2019

Two versions of a PPG/ECG combined system have been realized and tested. In a first version a multisite system has been equipped by integrating 3 PPG optodes and 3 ECG leads, whereas in another setup a portable version has been carried out. Both versions have been realized by equipping the optical probes with SiPM detectors. SiPM technology is expected to bring relevant advantages in PPG systems and overcome the limitations of physiological information extracted by state of the art PPG, such as poor sensitivity of detectors used for backscattered light detection and motion artifacts seriously affecting the measurements repeatability and pulse waveform stability. This contribution presents t…