34,044 research outputs found
Magnetoelectronic Phenomena at a Ferromagnet-Semiconductor Interface
A Comment on the Letter by P. R. Hammar et al., Phys. Rev. Lett. 83, 203 (1999)
Measuring and analysing vibration motors in insoles via accelerometers
Purpose: Falling is a major public health concern among elderly people, and they often cause serious injuries1,2. They most frequently occur during walking and are associated with the chronic deterioration in the neuromuscular and sensory systems, as well as with ankle muscle weakness and lower endurance of these muscles to fatigue1,3. Vibrating insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy4. The object of this study is to find the most suitable vibrator to put into the insole which can effectively improve the balance control of the elderlies. Method: We choose three different vibration actuators (micro vibration motor, brushless motor and eccentric motor) with two different weights on the insole. First, we put three same motors and two accelerometers on the insole, as shown in Figure1, then attach another layer on both side of the insole. Second, connect the motors to the power supply and the accelerometer to NI PXI-1033 spectrum analyzer which is used to collect the accelerometers' data. At last, using Fast Fourier Transform (FFT) to analyze and compare the results to see which motor is the most stable and suitable to put into the insole. Results & Discussion: The results showed that the most stable one is the brushless motor. The reason why the frequency is stable is that the relationship between voltage and frequency is linear, and the error is small through continuous measurements. On the other hand, when a person weight 55 kg stands on the insole, the frequency isn't affected by the weight. These two results appear very similar to each other, as shown in Figure 2. According to the result, we use the brushless motor to be our vibrator in the insole, and hope this will help the elderlies improve their balance control ability more efficiency
A unified approach to blending of constant and varying parametric surfaces with curvature continuity
In this paper, we develop a new approach to blending of
constant and varying parametric surfaces with curvature
continuity. We propose a new mathematical model consisting of a
vector-valued sixth-order partial differential equation (PDE) and
time-dependent blending boundary constraints, and develop an
approximate analytical solution of the mathematical model. The
good accuracy and high computational efficiency are
demonstrated by comparing the new approximate analytical
solution with the corresponding accurate closed form solution. We also investigate the influence of the second partial derivatives on
the continuity at trimlines, and apply the new approximate
analytical solution in blending of constant and varying parametric
surfaces with curvature continuit
Temperature Effects on Threshold Counterion Concentration to Induce Aggregation of fd Virus
We seek to determine the mechanism of like-charge attraction by measuring the
temperature dependence of critical divalent counterion concentration
() for the aggregation of fd viruses. We find that an increase in
temperature causes to decrease, primarily due to a decrease in the
dielectric constant () of the solvent. At a constant ,
is found to increase as the temperature increases. The effects of
and on can be combined to that of one parameter:
Bjerrum length (). decreases exponentially as
increases, suggesting that entropic effect of counterions plays an important
role at the onset of bundle formation.Comment: 12 pages, 3 figure
Integration of gradient least mean squares in bidirectional long short-term (LSTM) memory networks for metallurgical bearing ball fault diagnosis
This paper introduces a novel diagnostic approach for bearing ball failures: a synergistic implementation of a bidirectional Long Short-Term Memory (LSTM) network, empowered by Gradient Minimum Mean Square. This method leverages deep analysis of operational data from bearings, enabling the precise identification of incipient bearing ball failures at early stages, thus markedly improving prediction accuracy. Our empirical results underscore the superior performance of this composite methodology in accurately detecting a spectrum of five mechanical bearing ball failure types, achieving a substantial enhancement in diagnostic precision
Phase Separation of Bismuth Ferrite into Magnetite under Voltage Stressing
Micro-Raman studies show that under ~700 kV/cm of d.c. voltage stressing for
a few seconds, thin-film bismuth ferrite BiFeO3 phase separates into magnetite
Fe3O4. No evidence is found spectroscopically of hemite alpha-Fe2O3, maghemite
gamma-Fe2O3, or of Bi2O3. This relates to the controversy regarding the
magnitude of magnetization in BiFeO3.Comment: 9 pages and 2 figure
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