Stochastic resonance with different periodic forces in overdamped two coupled anharmonic oscillators

We study the stochastic resonance phenomenon in the overdamped two coupled anharmonic oscillators with Gaussian noise and driven by different external periodic forces. We consider (i) sine, (ii) square, (iii) symmetric saw-tooth, (iv) asymmetric saw-tooth, (v) modulus of sine and (vi) rectified sinusoidal forces. The external periodic forces and Gaussian noise term are added to one of the two state variables of the system. The effect of each force is studied separately. In the absence of noise term, when the amplitude $f$ of the applied periodic force is varied cross-well motion is realized above a critical value ($f_{\mathrm{c}}$) of $f$. This is found for all the forces except the modulus of sine and rectified sinusoidal forces.Stochastic resonance is observed in the presence of noise and periodic forces. The effect of different forces is compared. The logarithmic plot of mean residence time $\tau_{\mathrm{MR}}$ against $1/(D - D_{\mathrm{c}})$ where $D$ is the intensity of the noise and $D_{\mathrm{c}}$ is the value of $D$ at which cross-well motion is initiated shows a sharp knee-like structure for all the forces. Signal-to-noise ratio is found to be maximum at the noise intensity $D=D_{\mathrm{max}}$ at which mean residence time is half of the period of the driving force for the forces such as sine, square, symmetric saw-tooth and asymmetric saw-tooth waves. With modulus of sine wave and rectified sine wave, the $SNR$ peaks at a value of $D$ for which sum of $\tau_{MR}$ in two wells of the potential of the system is half of the period of the driving force. For the chosen values of $f$ and $\omega$, signal-to-noise ratio is found to be maximum for square wave while it is minimum for modulus of sine and rectified sinusoidal waves.Comment: 13 figures,27 page

DNA Intuitionistic fuzzy turing machine

The restriction enzymes of bacteria are used to cut and insert the two strands of double-stranded DNA at different positions that cause overhangs of single stranded DNA. We developed an encoding transition table of an intuitionistic fuzzy Turing machine that processes series of restriction(cut) and ligation of DNA fragments or oligonucleotides that can be used to find the Body Mass Index of human being.Publisher's Versio

Cultural Components in Karisal Region in the works of K.Ra

Among the literary personalities of Tamil language K. Ra (K.Rajanarayanan) has won a good place in people's minds through his works. K. Rajanarayanan lived in Karisal region created literary works based on the karisal region. He documented the traditions and cultural aspects of the Karisal land people through his works. He called himself as a vernacular artist and his works are very unique. This article explains about the beliefs, customs, rituals, weddings, festivals, worships and practices followed in the Karisal land and it expresses their culture

To Find the Effectiveness of Strengthening Exercises along with Stretching Exercises in the Gait Pattern of Stroke Patients

The idea that ‘increase effort will increase spasticity’ – still persist and many Neuro Rehabilitation Centre in the country are not using strengthening exercise in spastic adults with hemiplegia. Though spastic also shows some muscle weakness which can be improved by strengthening exercises, thus the study is planned to find out the effectiveness of strengthening exercise for the lower limb in gait performance in adults with using step length, stride length and speed. OBJECTIVES: 1. To achieve maximum gait performance in step length in response to strengthening exercise for adults with hemiplegia. 2. To achieve maximum gait performance in stride length in response to strengthening exercise for adults with hemiplegia. 3. To achieve maximum gait performance in speed in response to strengthening exercise for adults with hemiplegia. METHODOLOGY: STUDY DESIGN: Quazi Experimental. STUDY SETUP: 1. Madha Medical College and Research Institute Hospital, Kovur, Thandalam Chennai. 2. Focus Rehabilitation Centre Porur, Chennai. Population: All the patients who certified the selection criteria were the population of the study. Sample size: 30 subjects (Group A-15 patients and GroupB-15 patients). Inclusion criteria: 1. Moderately increase muscle tone (grade2 Modified Ashworth Scale). 2. Age group between 50 and 70 years. 3. Patients obeying commands. 4. Ambulatory adult. 5. Patient with moderate neurological deficit. 6. Patients having duration less than 3months of stroke attack. 7. Patients who are willing. Exclusion criteria: 1. Patient with associated cognitive deficit. 2. Patient with any lower limb joint deformity. 3.Any other major medical problems. RESULTS: The statistical results of the study is highly significant in both Control & Experimental group in all the three parameters of the gait pattern – Step length, Stride length, Speed length, following both strengthening & stretching exercises, on which the Experimental group showed higher percentage of improvement comparatively. CONCLUSION: This study adds to the accumulating evidence that strengthening exercise is beneficial in improving the walking ability of adults with spastic hemiplegia. The finding that there is no adverse effect accompanied with the positive outcomes

An Electron Microscope Study of Biomineralisation for Geotechnical Engineering Purposes

XJTL

PHYTOCHEMICAL ANALYSIS AND IN VITRO DPPH ASSAY OF ETHANOLIC EXTRACT OF MUCUNA PRURIENS SEED

Objective: To detect the bioactive phytoconstituents of Mucuna pruriens seed extract and to estimate invitro antioxidant activity. Methods: Preliminary phytochemical analysis were done to determine the active phytochemical constituents and DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay method was used for the estimation of In vitro antioxidant activity. Results: Preliminary phytochemical analysis of Mucuna pruriens seed extract showed the presence of chief bioactive components like phenols, flavonoids, tannins, alkaloids, triterpenes and phytosterols. In antioxidant assay, Mucuna pruriens seed extract exhibited a maximum DPPH radical scavenging activity of 72.95% against the standard control with a maximum activity of 93.24% for the same concentration (0.2 mg/ml). This is a clear indication of strong antioxidant property of the drug. Conclusion: Mucuna Pruriens seeds are abundant source of natural antioxidants, and important bioactive phytoconstituents

Harmonic minimization in modulated frequency single-phase matrix converter

Abstract: This Field Programmable Gate Array (FPGA) based digital controller has been developed to improve the output of the frequency converter using Hardware Description Language. An attempt has been made to analyze converters using three modulation techniques namely sinusoidal pulse width modulation (SPWM), delta modulation (DM) and trapezoidal modulation (TM) to reduce the harmonics. It has been found that for the Sine PWM, the total harmonic distortion factor (THD) is high when the output frequency is greater than input frequency. The output is improved with delta modulation scheme where the total harmonic distortion is found minimum as compare to the SPWM and TM techniques. The circuit has been tested qualitatively by observing various waveforms on digital storage oscilloscope (DSO). The overall system is compact and no external memory system is required. Tests have been carried out to show the effectiveness and flexibility of the proposed method

Comparative analysis of modulation techniques in frequency converter

Abstract: A generalized frequency converter has been realized which makes use of a cyclo-converter in newer form AC-AC converter. An attempt has been made to operate this converter both in a conventional low frequency AC-AC converter and a new high frequency AC-AC converter. The ability to directly affect the frequency conversion of power without any intermediate stage involving DC power is a huge advantage of the system. The output of this converter has a frequency either fo = fi × Nr or fo = fi / Nr. where Nr is an integer and fi is the source frequency. A methodology is developed to generate the required trigger signal for any integer multiple/sub multiple of the output frequency. The undesirable harmonic components in the output of the frequency converter have been minimized using four modulation techniques namely; sinusoidal pulse width modulation (SPWM), delta modulation (DM), trapezoidal modulation (TM) and space vector modulation (SVM) technique. The converter is simulated using well known software package MATLAB. Comparative simulation analysis is presented for a single phase frequency converter (SPFC) topology with all these modulation techniques when the converter is operating both step up as well as for step down mode