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2021 ◽  
Author(s):  
Matthias Konrad Werner ◽  
Daniel Maier ◽  
Lorenzo Scandola ◽  
Wolfram Volk

In freeform bending the desired geometry is created by defined movements of the die while a continuous feed takes place. To compensate the differences and variations in properties of the semi-finished product, the motion profile has to be adjusted. Currently, this calibration is done once before the manufacturing process of a certain profile. Therefore, numerous iterations consisting of bending and measuring certain radii based on a default motion profile are performed. The measured data is subjected to a curve fit, which is not sufficiently suitable for all profiles and materials setups due to the fixed predefined function that is used. Furthermore, the tool setup is not taken in account. This results in wrong kinematics and production rejects. In this work, an enhanced geometrical model is introduced which incorporates tool parameters - such as distances, clearances and positioning aspects - as a starting point for further calculations. Furthermore, different calibration methods are tested and compared to each other using FEM simulations to fit the calculated curve to the actually used specimen. This work establishes the basis for further compensation and calibration strategies in order to improve the handling of varying properties of semi-finished products within the freeform bending process.


Author(s):  
P. Rajagopaludu ◽  
N. Saritha ◽  
N. Devanna ◽  
M. Srinivas

Aim: For the Method development and validation of Anabasine and Nornicotine in human plasma LC-MS/MS technique is used. Methodology: Operated in positive electron spray ionization which removes the hardness in ions. Metoprolol is used as an internal standard. Mass analyzers are used to determine the mass to charge ratio. Liquid chromatography separates mixture components in the basis of differences in affinity for stationary and mobile phase. It removes undesired impurities. It increases reproducibility, sensitivity, robustness, detection of low-level proteins.  C18 Column (Phenomenex Luna C18, 5 μm, 50*4.6mm ID) is used to for high resolution and peak area. Calibration curve is constructed with the help of linear regression. During the entire process no instability is found. Results: m/z values of Anabasine are 162.84(Q1), 134.68(Q3) and for Nornicotine are 148.90(Q1), 79.82(Q3). Back calculated curve is calculated at different concentrations from 1-1000ng/ml and their accuracy range from 97-105% for Anabasine and 93-108% for Nornicotine. In Anabasine and Nornicotine the precision and accuracy are calculated by Intra-batch and inter-batch. In the process of multi-step preparation, consider n=6 for intra-batch and n=18 for inter-batch the values obtained are between the nominal concentrations i.e., 90-110%. For each analyte the coefficients of variation are below nominal criteria <15%.  For Anabasine and Nornicotine the average recovery rate is 98.3% and 94.3%.


Cybersecurity ◽  
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shafi Ullah ◽  
Raja Zahilah

AbstractRobust encryption techniques require heavy computational capability and consume large amount of memory which are unaffordable for resource constrained IoT devices and Cyber-Physical Systems with an inclusion of general-purpose data manipulation tasks. Many encryption techniques have been introduced to address the inability of such devices, lacking in robust security provision at low cost. This article presents an encryption technique, implemented on a resource constrained IoT device (AVR ATmega2560) through utilizing fast execution and less memory consumption properties of curve25519 in a novel and efficient lightweight hash function. The hash function utilizes GMP library for multi-precision arithmetic calculations and pre-calculated curve points to devise a good cipher block using ECDH based key exchange protocols and large random prime number generator function.


2019 ◽  
Vol 37 (4) ◽  
pp. 397
Author(s):  
Nelson Ricardo Coelho Flores Zuniga ◽  
Eder Cassola Molina ◽  
Renato Luiz Prado

AbstractThe processing of multicomponent seismic data is already a challenge concerning the velocity analysis. When it is performed for offshore survey, the difficulty increases a lot more with the use of OBN (Ocean Bottom Nodes) technology. The ray tracing asymmetry generated by the wave conversion and the difference of datum between source and receptor are not the only factors which contribute for a strongly nonhyperbolic travel-time event. The layered subsurface models and the large offsets employed in the offshore surveys make the nonhyperbolicity even stronger. Aiming to solve this problem, eight approximations to perform the velocity analysis were tested for two models. The complexity analysis of each nonhyperbolic multiparametric approximation was also studied to understand their behaviors during the optimization process. The relative error between the observed curve and the calculated curve with each approximation was computed for PP and PS reflection events of two models. With these informations, it was possible to determine which approximation is the most reliable one for this kind of models.Keywords: multicomponent, OBN, nonhyperbolic, multiparametric. ResumoO processamento de dados sísmicos multicomponentes já é um desafio com relação à análise de velocidades. Quando realizado para levantamentos marítimos, a dificuldade aumenta muito mais com o uso da tecnologia OBN (Ocean Bottom Nodes). A assimetria no traçado de raios gerada pela conversão de onda e pela diferença de profundidade entre fonte e receptor não são os únicos fatores que contribuem para um evento de tempos de trânsito fortemente não-hiperbólico. Os modelos estratificados de subsuperfície e os grandes afastamentos aplicados nos levantamentos marítimos tornam a não-hiperbolicidade ainda mais forte. Visando resolver este problema, oito aproximações para realizar a análise de velocidades foram testadas para dois modelos. A análise de complexidade de cada aproximação não-hiperbólica multiparamétrica também foi estudada para entender seus comportamentos durante o processo de otimização. Os erros relativos entre as curvas observadas e calculadas com cada aproximação foram calculados para os eventos de reflexão PP e PS dos dois modelos. Com estas informações, foi possível determinar qual aproximação é a mais confiável para estes tipos de modelos.Palavras-chave: multicomponente, OBN; não-hiperbólico, multiparamétrico.


2019 ◽  
Vol 7 (4) ◽  
pp. 321-328
Author(s):  
Nelson Ricardo Flores Zuniga

In the last decade, many works compared nonhyperbolic multiparametric travel-time approximations to perform velocity analysis. In these works, some analyses were accomplished, such as accuracy analysis and objective function analysis. However, no previous works compared the optimization algorithms to perform the inversion procedure concerning the processing time and the accuracy of each algorithm. As the shifted hyperbola showed the best results among the unimodal approximations in previous works, it was selected to be used in a comparison with five local search optimization algorithms. Each algorithm was compared concerning the accuracy by the minimization of the calculated curve to the observed curve. The travel-time curves tested here are conventional (PP) and converted wave (PS) reflection events from an offshore model. With this set of tests, it is possible to define which optimization algorithm presents the most reliable result when used with the shifted hyperbola equation concerning the processing time and the accuracy.


2016 ◽  
Vol 49 (1) ◽  
pp. 311-316 ◽  
Author(s):  
M. Souilah ◽  
A. Boulle ◽  
A. Debelle

RaDMaX(radiation damage in materials analysed with X-ray diffraction) is a user-friendly graphical program that allows the determination of strain and damage depth profiles in ion-irradiated crystals. This task is achieved by fitting experimental X-ray diffraction data, recorded in symmetrical θ–2θ geometry, with a dynamical diffraction model parametrized with variable strain and damage profiles based onB-spline functions. The strain and damage profiles can be graphically manipulated so as to fit the calculated curve to the experimental data. Automatic fitting procedures (generalized simulated annealing and conventional least squares) are also implemented.RaDMaXis free and open source (CeCILL licence) and can be downloaded from http://aboulle.github.io/RaDMaX.


2014 ◽  
Vol 60 (No. 1) ◽  
pp. 1-8
Author(s):  
M. Mimra ◽  
M. Kavka ◽  
K. Tomšík ◽  
M. Struhár

The &ldquo;boundary line analysis method&rdquo; calculates the minimal total annual operational costs used for the optimisation of number of tractors owned by agricultural companies. This calculation reflects the actual need of tractors used in the selected time periods during a year. The above method is based on data gained during five day periods (so-called pentads) in the plant production Farm Estate L&aacute;ny which belongs to the Czech University of Life Sciences Prague. Based on the annual use of tractors in the company, operational costs involve tractors owned and hired. The calculated curve changes in relation to the total annual costs for the owned tractors. The economically optimal number of the owned tractors would be reached at the minimum point where the total annual costs curve is low whilst all working operations in the company have been done. Due to the use of tractors during the pentads, it is recommended to own exactly the number of tractor-machine sets given by the calculated minimum. For all the other works, it is advisable to use hired tractors, operationally leased tractors or outsourced services.


2011 ◽  
Vol 110-116 ◽  
pp. 3389-3393
Author(s):  
Yan Mei Xu ◽  
Chong Liu

In the paper a new method is presented to simulate the course of light output from organic light emitting device. The method uses optical transmission matrix to deal with multiple layers. To confirm the validity of our theories, a comparison of the theoretic analysis with testing results is given. The calculated curve consistented with the experimental value. By this methoed the Commission Internationale de L'Eclairage (CIE) coordinates of device were simulated. By adjusting the thickness of each layer in organic light emission diode (OLED) we obtained different CIE coordinates. When thickness becomes thicker the CIEX becomes bigger on the other hand CIEY become smaller.


2010 ◽  
Vol 108-111 ◽  
pp. 1152-1157
Author(s):  
Ming Lu ◽  
Liu Peng ◽  
Ling Li ◽  
Xin Wei Ji

Constant variably acceleration motion model of flying plate is proposed and the model formula about the relationship between speed of flying plate and clearance is put forward, which provides theorotical basis for choosing optimum clearance by collision speed of different metallic materials in explosive welding industry production. High pressure impulse X radial photograph experiment was carried out, the photos of the flying stances of flying plate in different clearances were obtained and the corresponding flying speeds of flying plate were calculated. Curve fitting of the experiment data through constant variably acceleration motion model was carried out. The results show that constant variably acceleration motion model accords well with the experiment data,and the maximum speed of flying plate calculated through constant acceleration model is in good agreement with the values through theoretical calculation. Therefore, it is concluded that the motion of flying plate in the main follows the constant variably acceleration motion.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2034-2034 ◽  
Author(s):  
Anthony F. Waller ◽  
Fengrong Wang ◽  
Ned Waller

Abstract Background: The use of UCB transplants is limited by the difficulty of finding units with sufficient cells to provide reliable engraftment, and the slower kinetics of hematopoietic engraftment compared to other hematopoietic progenitor cell grafts. Grafts consisting of two unrelated UCB result in accelerated engraftment compared to single unit UCB transplants, but the mechanism for enhanced engraftment is unknown. Methods: We extracted data from published studies on myeloid engraftment following transplantation of single (9 studies, 1542 engrafted patients) or double (4 studies, 94 engrafted patients) UCB units (Table). A weighted average of median days (and estimated SD) to engraft for single and double UCB transplants was calculated. The cumulative incidence of myeloid engraftment for single or double UCB transplants was modeled based the assumption that the time to engraft was described by a normal distribution. For double and triple UCB transplants, the probability of myeloid engraftment at any time post-transplant was calculated as 1 minus the probability of non-engraftment for a single UCB unit squared or cubed, respectively. Results: The weighted average percentage for myeloid engraftment following single UCB transplants was 89%, with a median day of engraftment of 26.4 days. The weighted average for the rate of myeloid engraftment following double UCB transplants was 96%, with a median day of engraftment of 22 days. The calculated median days to engraft from single or double UCB transplants, using the assumption of normal distributions, were 22 and 26 days, respectively. Applying the mathematical model, the predicted cumulative engraftment for a double UCB graft is 99%, with a the curve for cumulative engraftment kinetics quite similar to the observed engraftment in Barker 2005 and the calculated curve for double UCB transplants based upon analysis of extracted data (Figure). Conclusion: UCB units do not appear to facilitate engraftment in grafts containing multiple units. A stochastic statistical model, in which different UCB grafts engraft independently, appears to account for the observed 4-day decrease in the median time to achieve myeloid engraftment following a double versus single UCB transplant. The use of a triple UCB graft is predicted to shorten the median time to achieve neutrophil engraftment to a median of 20 days. Published experiences describing myeloid engraftment following single and double UCB transplants Single UCB Transplant N, % engrafted Median day to engraft Double UCB Transplants N, % engrafted Median day to engraft Laughlin NEJM 2001 N=61, 90% 27 Barker Blood 2005 N=50, 100% 23 Hamza BJH 2004 N=28, 86% 29 Yoo ASH 2005 N=12, 100% 23 Barker Blood 2001 N=31, 88% 26 Kai ASH 2004 N=11, 82% 21 Thomson Blood 2000 N=30, 81% 25 Ballen ASH 2005 N=21, 90% 20 Sanz Blood 2001 N=22, 100% 22 Terakura BBMT 2007 N=148, 81% 22 Wagner Blood 2002 N=102, 86% 22 Migliaccio Blood 2000 N=200, 91% 28 Stevens Blood 2002 N=1111, 90% 27 Figure Figure


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