Arctangent function-based third derivative attribute for characterisation of faults

2016 ◽  
Vol 65 (4) ◽  
pp. 913-925 ◽  
Author(s):  
Jingbo Yu ◽  
Zhong Li
2011 ◽  
Vol 6 ◽  
pp. ACI.S7282 ◽  
Author(s):  
Nashwah Gadallah Mohamed

A spectrophotometric method was developed for simultaneous determination of amlodipine (Aml) and valsartan (Val) without previous separation. In this method amlodipine in methanolic solution was determined using zero order UV spectrophotometry by measuring its absorbency at 360.5 nm without any interference from valsartan. Valsartan spectrum in zero order is totally overlapped with that of amlodipine. First, second and third derivative could not resolve the overlapped peaks. The first derivative of the ratio spectra technique was applied for the measurement of valsartan. The ratio spectrum was obtained by dividing the absorption spectrum of the mixture by that of amlodipine, so that the concentration of valsartan could be determined from the first derivative of the ratio spectrum at 290 nm. Quantification limits of amlodipine and valsartan were 10-80 μg/ml and 20-180 μg/ml respectively. The method was successfully applied for the quantitative determination of both drugs in bulk powder and pharmaceutical formulation.


Author(s):  
Clément M. Gosselin ◽  
Ammar Hadj-Messaoud

Abstract This paper proposes some new polynomial solutions to the trajectory planning problem encountered in pick-and-place operations. When a robotic manipulator is used for such operations, it is possible to plan the required trajectory in joint space, provided that the inverse kinematic problem has been solved for the initial and final configurations — and possibly for a lift-off and a set-down configuration — and that the workspace is free of obstacles. Polynomial solutions to this problem can be found in the literature. However, they usually provide continuity up to the second derivative only, leading to a discontinuous jerk. The solutions derived in this paper preserve the continuity of the third derivative of the joint coordinates, thereby ensuring smooth trajectories with smooth variations of the actuator currents. Moreover, whenever possible, unique polynomial expressions valid between the initial and final configurations are used in order to simplify the logic. Polynomial formulations without lift-off and set-down configurations are first presented. Then, these intermediate configurations are introduced, leading to a new set of solutions. A global algorithm is then discussed in order to clearly indicate the relationship between the different solutions. Finally, an example illustrating the application to a pick-and-place operation is solved.


2013 ◽  
Vol 30 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Xavier Girones ◽  
Carme Julia ◽  
Domenec Puig

2021 ◽  
pp. 1-6
Author(s):  
Kyle B. Kosik ◽  
Kathryn Lucas ◽  
Matthew C. Hoch ◽  
Jacob T. Hartzell ◽  
Katherine A. Bain ◽  
...  

Studies have demonstrated that individuals with chronic ankle instability (CAI) have diminished dynamic stability. Jerk-based measures have been utilized to examine dynamic balance because of their ability to quantify changes in acceleration and may provide an understanding of the postural corrections that occur during stabilizing following a jumping task. The purpose of this study was to compare acceleration and jerk following a jump stabilization task between individuals with CAI and the uninjured controls. Thirty-nine participants volunteered to participate in this case control study. Participants completed a jump stabilization task requiring them to jump off 2 feet, touch a marker set at 50% of their maximal vertical jump height, land on a single limb, and maintain balance for 3 seconds. Acceleration was calculated as the second derivative, and jerk was calculated as the third derivative of the displacement of the resultant vector position. Participants with CAI had greater acceleration (mean difference = 55.6 cm/s2; 95% confidence interval, 10.3 to 100.90; P = .017) and jerk compared with the uninjured controls (mean difference = 1804.5 cm/s3; 95% confidence interval, 98.7 to 3510.3; P = .039). These results suggest that individuals with CAI made faster and more frequent active postural control corrections to regain balance following a jump compared with the uninjured controls.


2020 ◽  
Vol 222 (3) ◽  
pp. 1898-1908
Author(s):  
Toshio Fukushima

SUMMARY By utilizing the addition theorems of the arctangent function and the logarithm, we developed a new expression of Bessel’s exact formula to compute the prismatic gravitational field using the triple difference of certain analytic functions. The use of the new expression is fast since the number of transcendental functions required is significantly reduced. The numerical experiments show that, in computing the gravitational potential, the gravity vector, and the gravity gradient tensor of a uniform rectangular parallelepiped, the new method runs 2.3, 2.3 and 3.7 times faster than Bessel’s method, respectively. Also, the new method achieves a slight increase in the computing precision. Therefore, the new method can be used in place of Bessel’s method in any situation. The same approach is applicable to the geomagnetic field computation.


2017 ◽  
Vol 100 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Nisreen F Abo-Talib ◽  
Mohamed R El-Ghobashy ◽  
Marwa H Tammam

Abstract Sofosbuvir and ledipasvir are the first drugs in a combination pill to treat chronic hepatitis C virus. Simple, sensitive, and rapid spectrophotometric methods are presented for the determination of sofosbuvir and ledipasvir in their combined dosage form. These methods were based on direct measurement of ledipasvir at 333 nm (due to the lack of interference of sofosbuvir) over a concentration range of 4.0–14.0 µg/mL, with a mean recovery of 100.78 ± 0.64%. Sofosbuvir was determined, without prior separation, by third-derivative values at 281 nm; derivative ratio values at 265.8 nm utilizing 5.0 µg/mL ledipasvir as a divisor; the ratio difference method using values at 270 and 250 nm using 5.0 µg/mL ledipasvir as a divisor; and the ratio subtraction method using values at 261 nm. These methods were found to be linear for sofosbuvir over a concentration range of 5.0–35.0 µg/mL. The suggested methods were validated according to International Conference on Harmonization guidelines. Statistical analysis of the results showed no significant difference between the proposed methods and the manufacturer's LC method of determination with respect to accuracy and precision. These methods were used to compare the equivalence of an innovator drug dosage form and two generic drug dosage forms of the same strength.


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