Pulse Filtering and Correction For CZT Detectors Using Simple Digital Algorithms Based on The Wavelet Transform

1997 ◽  
Vol 487 ◽  
Author(s):  
J. M. Pérez ◽  
G. García-Belmonte
Keyword(s):  
Wavelet Transforms ◽  
Signal Analysis ◽  
Simple Method ◽  
New Approach ◽  
Pulse Processing ◽  
Hole Charge ◽  
Charge Loss ◽  
Digital Algorithms ◽  
Czt Detectors ◽  
Semiconductor Gamma

AbstractWe report an approach to double gaussian filtering used in classical works as dual parameter pulse processing. This technique has been implemented by creating a bank of gaussian-like digital filters based on wavelet transforms. A simple method to correct for the charge loss inherent to room temperature semiconductor gamma detectors has been developed. This method is based on multi-resolution signal analysis. Results are reported from tests of these algorithms on commercial CZT detectors and two trapped hole charge correction levels are compared. Finally, the advantages and limitations of this new approach to detector pulse processing are discussed.

scholarly journals Classic adsorption isotherms incorporated in modern surface complexation models: Implications for sorption of actinides

2006 ◽  
Vol 94 (9-11) ◽  
Author(s):  
Dimitrii A. Kulik
Keyword(s):  
Surface Complexation ◽  
Real Surface ◽  
Density Parameter ◽  
Surface Species ◽  
Lateral Interactions ◽  
Surface Binding ◽  
Simple Method ◽  
New Approach ◽  
Langmuir Isotherms ◽  
Adsorption Equilibria

Computer-aided surface complexation models (SCMs) are widely used in describing mineral-water interface reactions such as sorption of actinides onto (hydr)oxides and clays. Most SCMs are built upon balances of surface binding sites. In fact, such models can reproduce only competitive Langmuir isotherms, plus optional electrostatic corrections. Hence, it may be difficult to extend such SCMs to some real-surface phenomena (site heterogeneity, lateral interactions, surface precipitation) described in isotherms other than Langmuir. In this contribution, a new approach to overcome this difficulty is presented which does not use surface site balances, is not restricted only to Langmuir isotherms, and can be implemented within the Gibbs energy minimization solvers of chemical (adsorption) equilibria. It is suggested to define the ideal behavior of a surface species using a linear isotherm only. Conversely, an adsorption isotherm equation of choice can be split into a linear term (involving the standard-state density and the equilibrium constant referenced to infinite dilution) and a non-linear surface activity coefficient term (SACT, involving the site density parameter). A simple method is proposed for deriving a SACT for the monodentate surface binding from the Langmuir isotherm. This method is then applied to obtain SACTs for mono-, bi-, tri- and tetra-dentate binding from the “quasi-chemical approximation” isotherm, as well as a SACT accounting for non-ideal lateral interactions between surface species from the Frumkin isotherm. The new approach is illustrated by modeling U

A Simple Method for Estimating the Parameters of the Beta Distribution Applied to Modeling Uncertainty in Gas Turbine Inlet Temperature

2002 ◽  
Author(s):  
Frederic A. Holland
Keyword(s):  
Standard Deviation ◽  
Conventional Method ◽  
Beta Distribution ◽  
Conventional Approach ◽  
Algebraic Solution ◽  
Inlet Temperature ◽  
Shape Parameters ◽  
Simple Method ◽  
New Approach ◽  
A Value

The beta distribution is a particularly convenient model for random variables when only the minimum, maximum and most likely values are available. It is also very useful for estimating the mean and standard deviation given this information. In this paper a simple method is proposed to estimate the beta parameters from these three values. The proposed method has advantages over the conventional approach. In the conventional approach, the four parameters of the beta distribution are determined from only three values by assuming a standard deviation that is one-sixth the range. In contrast, the new method assumes a value for one of the beta shape parameters based on an analogy with the normal distribution. This new approach allows for a very simple algebraic solution of the beta shape parameters in contrast to the simultaneous solution required by the conventional method. The results of the proposed method are very similar to the conventional method. However, the proposed method generally gives a slightly higher (more conservative) estimate of the standard deviation when the distribution is skewed. In addition, the new approach allows the standard deviation to vary as the shape or skew of the distribution varies. Both methods were applied to modeling the probability distribution of temperature.

scholarly journals Simple Method to Improve Electrical Conductivity of Films Made from Single-Walled Carbon Nanotubes

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1113 ◽  
Author(s):  
Bogumiła Kumanek ◽  
Tomasz Wasiak ◽  
Grzegorz Stando ◽  
Paweł Stando ◽  
Dariusz Łukowiec ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Single Walled Carbon Nanotubes ◽  
Simple Approach ◽  
Sonication Time ◽  
Free Standing ◽  
Simple Method ◽  
New Approach ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Despite the widespread use of sonication for individualization of nanomaterials, its destructive nature is rarely acknowledged. In this study, we demonstrated how exposure of the material to a hostile sound wave environment can be limited by the application of another preprocessing step. Single-walled carbon nanotubes (CNTs) were initially ground in a household coffee grinder, which enabled facile deagglomeration thereof. Such a simple approach enabled us to obtain high-quality CNT dispersion at reduced sonication time. Most importantly, electrical conductivity of free-standing films prepared from these dispersion was improved almost fourfold as compared with unground material eventually reaching 1067 ± 34 S/cm. This work presents a new approach as to how electrical properties of nanocarbon ensembles may be enhanced without the application of doping agents, the presence of which is often ephemeral.

CWT × DWT × DTWT × SDTWT: Clarifying terminologies and roles of different types of wavelet transforms

2020 ◽  
Vol 18 (06) ◽  
pp. 2030001 ◽  
Author(s):  
Rodrigo Capobianco Guido ◽  
Fernando Pedroso ◽  
André Furlan ◽  
Rodrigo Colnago Contreras ◽  
Luiz Gustavo Caobianco ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Discrete Time ◽  
Wavelet Transforms ◽  
Signal Analysis ◽  
Applied Mathematics ◽  
Discrete Wavelet ◽  
Frequency Signal ◽  
Time Frequency ◽  
Subsequent Investigation ◽  
Different Types

Wavelets have been placed at the forefront of scientific researches involving signal processing, applied mathematics, pattern recognition and related fields. Nevertheless, as we have observed, students and young researchers still make mistakes when referring to one of the most relevant tools for time–frequency signal analysis. Thus, this correspondence clarifies the terminologies and specific roles of four types of wavelet transforms: the continuous wavelet transform (CWT), the discrete wavelet transform (DWT), the discrete-time wavelet transform (DTWT) and the stationary discrete-time wavelet transform (SDTWT). We believe that, after reading this correspondence, readers will be able to correctly refer to, and identify, the most appropriate type of wavelet transform for a certain application, selecting relevant and accurate material for subsequent investigation.

A New Approach for Exact/Approximate Point Synthesis of Planar Mechanisms

2005 ◽  
Author(s):  
Ahmad Smaili ◽  
Nadim Diab
Keyword(s):  
Synthesis Method ◽  
Dimensional Synthesis ◽  
Gradient Search ◽  
Planar Mechanisms ◽  
Simple Method ◽  
New Approach ◽  
Optimum Synthesis ◽  
Approximate Synthesis ◽  
Optimum Solution ◽  
Synthesis Approach

The aim of this article is to provide a simple method to solve the mixed exact-approximate dimensional synthesis problem of planar mechanism. The method results in a mechanism that can traverse a closed path with the choice of any number of exact points while the rest are approximate points. The algorithm is based on optimum synthesis rather than on precision position methods. Ant-gradient search is applied on an objective function based on log10 of the error between the desired positions and those generated by the optimum solution. The log10 function discriminates on the side of generating miniscule errors (on the order of 10−14) at the exact points while allowing for higher errors at the approximate positions. The algorithm is tested by way of five examples. One of these examples was used to test exact/approximate synthesis method based on precision point synthesis approach.

Grading of Adductor Spasticity in Cerebral Palsy – A New Approach

2015 ◽  
Vol 26 (1) ◽  
pp. 2-5
Author(s):  
Vinay Goyal ◽  
Nonica Laisram
Keyword(s):  
Cerebral Palsy ◽  
Clinical Practice ◽  
Drug Therapy ◽  
Therapeutic Intervention ◽  
Physical Activities ◽  
Spastic Cerebral Palsy ◽  
Simple Method ◽  
New Approach ◽  
Visual Method ◽  
Grade 3

Abstract Spastic cerebral palsy is the most common form of cerebral palsy. Spasticity in hip adductor causes discomfort, stiffness and difficulties in performing physical activities such as seating, transfers and walking. Grading of hip adductor spasticity is still a challenge in the field of rehabilitation. A simple method to assess hip adductor spasticity and use it as outcome measures of intervention is needed in general clinical practice. We propose a visual method for grading hip adductor spasticity i.e grade 1= touch at ankle, grade 2 = crossing at ankle and grade 3 = crossing at knee in spastic cerebral palsy children. We followed 60 spastic cerebral palsy children over a period of three months on oral antispastic medication and found it very useful to assess response to drug. Intially hip adductor spasticity of grade 3 was observed in 10 %, grade 2- 8.33%, grade 1- 26.66% and 45% patients had no scissoring. After three months of drug therapy improvement was observed as grade 3 seen in 1 %, grade 2 - 7%, grade 1 - 23.33% and patients with no scissoring rose to 63.3%. These observations show that visual method for hip adductor spasticity is a simple and helpful method for grading response to therapeutic intervention.

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