scholarly journals Reduced Germline Mobility of a mariner Vector Containing Exogenous DNA: Effect of Size or Site?

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1299-1306 ◽  
Author(s):  
Allan R Lohe ◽  
Daniel L Hartl
Keyword(s):  
Genetic Engineering ◽  
Transposable Element ◽  
Frequency Analysis ◽  
Relative Stability ◽  
Low Frequency ◽  
Economic Importance ◽  
Exogenous Dna ◽  
Valuable Property ◽  
Reduced Mobility

Abstract Germline mobilization of the transposable element mariner is severely inhibited by the insertion of a 4.5- to 11.9-kb fragment of exogenous DNA into a unique SacI site approximately in the middle of the 1286bp element. In the presence of transposase driven by the germline-specific hsp26-sgs3 promoter, mobilization of the MlwB construct (containing a 11.9-kb insertion) is detected at low frequency. Analysis of a mobilized MlwB element indicated that mobilization is mediated by the marinertransposase. However, transposed MlwB elements are also defective in germline mobilization. Rare, transposase-induced germline excision events were also recovered for such vectors. The estimated rate of excision is <0.1% per chromosome per generation. Excision appears to be accompanied by gap repair if a suitable template is available. The data imply that the reduced mobility of mariner vectors with exogenous DNA in the SacI site results from disruption of sequences necessary for efficient mobilization. The relative stability may be a valuable property in the uses of mariner-like elements in genetic engineering of insects of economic importance.

scholarly journals On some restrictions in parametric synthesis of PID controllers

2020 ◽  
Vol 2020 (2) ◽  
pp. 7-18
Author(s):  
Goerun Kachperunovich Ayazyan ◽  
Elena Viktorovna Tausheva
Keyword(s):  
Relative Stability ◽  
Low Frequency ◽  
Stability Margin ◽  
Pid Controllers ◽  
Parametric Synthesis ◽  
Symbolic Calculations ◽  
Methods Of Synthesis ◽  
The Given ◽  
Limiting Values ◽  
Fractional Orders

The article highlights solving the problem of parametric synthesis of PID Controllers of integer and fractional orders. The methods of synthesis for the given margins and indices of the relative stability of PID Controllers of integral and fractional orders have been developed. There have been developed algorithms for calculating the limiting values of the controller differential gain, at which the boundary of the region of a given stability margin has a cusp. Applying the criterion for low-frequency disturbance compensation helps to define the limiting values of the relative stability margin and indices. To implement the proposed algorithms there have been developed the software in the environment of the Maple package of symbolic calculations. Application of the developed algorithms allows to narrow the search area for the PID Controllers optimal parameters.

Low - Frequency analysis of super yacht free vibrations

2019 ◽  
Vol 176 ◽  
pp. 199-210
Author(s):  
G. Vergassola ◽  
T. Pais ◽  
D. Boote
Keyword(s):  
Frequency Analysis ◽  
Low Frequency ◽  
Free Vibrations

scholarly journals Application of S-Transform in ISAR Imaging

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 676 ◽  
Author(s):  
Bo Zang ◽  
Mingzhe Zhu ◽  
Xianda Zhou ◽  
Lu Zhong
Keyword(s):  
Frequency Analysis ◽  
Low Frequency ◽  
Frequency Region ◽  
Echo Signal ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
S Transform ◽  
Isar Imaging ◽  
Body Components ◽  
Over Time

In inverse synthetic aperture radar (ISAR) imaging, time-frequency analysis is the basic method for processing echo signals, which are reflected by the results of time-frequency analysis as each component changes over time. In the time-frequency map, a target’s rigid body components will appear as a series of single-frequency signals in the low-frequency region, and the micro-Doppler components generated by the target’s moving parts will be distributed in the high-frequency region with obvious frequency modulation. Among various time-frequency analysis methods, S-transform is especially suitable for analyzing these radar echo signals with micro-Doppler (m-D) components because of its multiresolution characteristics. In this paper, S-transform and the corresponding synchrosqueezing method are used to analyze the ISAR echo signal and perform imaging. Synchrosqueezing is a post-processing method for the time-frequency analysis result, which could retain most merits of S-transform while significantly improving the readability of the S-transformation result. The results of various simulations and actual data will show that S-transform is highly matched with the echo signal for ISAR imaging: the better frequency-domain resolution at low frequencies can concentrate the energy of the rigid body components in the low-frequency region, and better time resolution at high frequencies can better describe the transformation of the m-D component over time. The combination with synchrosqueezing also significantly improves the effect of time-frequency analysis and final imaging, and alleviates the shortcomings of the original S-transform. These results will be able to play a role in subsequent work like feature extraction and parameter estimation.

Time-Frequency Analysis of Pressure Fluctuations on a Hydrofoil Undergoing a Transient Pitching Motion Using Hilbert-Huang and Teager-Huang Transforms

2007 ◽  
Author(s):  
S. Benramdane ◽  
J. C. Cexus ◽  
A. O. Boudraa ◽  
J.-A. Astolfi
Keyword(s):  
Frequency Analysis ◽  
Pressure Coefficient ◽  
Pressure Fluctuations ◽  
Low Frequency ◽  
Suction Side ◽  
Intrinsic Mode Functions ◽  
Pitching Motion ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
The Hilbert Transform

In this paper, time-frequency analysis of wall pressure signals of a hydrofoil’s suction side undergoing a forced transient pitching motion with incoming flow is conducted. A novel method recently introduced by Huang et al., the Empirical Mode Decomposition (EMD), is first used to decompose resulting non-stationary signals into frequency sub-band components called Intrinsic Mode Functions (IMFs). EMD-filtered pressure coefficient signals are then reconstructed from few selected IMFs from low frequency modes and time-frequency analysis performed on high frequency modes. For this latter purpose, two analysis methods are used. The first one consists in demodulating IMFs into their Instantaneous Amplitude (IA) and Instantaneous Frequency (IF) using the Hilbert transform and the second one is based on the Teager energy tracking operator (TEO). The transition occurrence is analyzed using IA and IF of extracted IMFs from chordwise pressure transducer’s signals. This transition occurrence is then described in time-frequency domain.

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