scholarly journals Mathematical model of a serine integrase-controlled toggle switch with a single input

2018 ◽  
Vol 15 (143) ◽  
pp. 20180160 ◽  
Author(s):  
Alexandra Pokhilko ◽  
Oliver Ebenhöh ◽  
W. Marshall Stark ◽  
Sean D. Colloms
Keyword(s):  
Basic Element ◽  
Toggle Switch ◽  
Dna Inversion ◽  
Molecular Noise ◽  
Genetic Switches ◽  
Input Control ◽  
Input Signals ◽  
Transcription Regulators ◽  
Single Input ◽  
And Control

Dual-state genetic switches that can change their state in response to input signals can be used in synthetic biology to encode memory and control gene expression. A transcriptional toggle switch (TTS), with two mutually repressing transcription regulators, was previously used for switching between two expression states. In other studies, serine integrases have been used to control DNA inversion switches that can alternate between two different states. Both of these switches use two different inputs to switch ON or OFF. Here, we use mathematical modelling to design a robust one-input binary switch, which combines a TTS with a DNA inversion switch. This combined circuit switches between the two states every time it receives a pulse of a single-input signal. The robustness of the switch is based on the bistability of its TTS, while integrase recombination allows single-input control. Unidirectional integrase-RDF-mediated recombination is provided by a recently developed integrase-RDF fusion protein. We show that the switch is stable against parameter variations and molecular noise, making it a promising candidate for further use as a basic element of binary counting devices.

scholarly journals Robust Synchronization of Delayed Chaotic FitzHugh-Nagumo Neurons under External Electrical Stimulation

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Muhammad Rehan ◽  
Keum-Shik Hong
Keyword(s):  
Electrical Stimulation ◽  
Nonlinear Control ◽  
Control Law ◽  
Input Control ◽  
Control Schemes ◽  
Multiple Input ◽  
Cognitive Diseases ◽  
Single Input ◽  
Error Dynamics ◽  
Nonlinear Control Law

Synchronization of chaotic neurons under external electrical stimulation (EES) is studied in order to understand information processing in the brain and to improve the methodologies employed in the treatment of cognitive diseases. This paper investigates the dynamics of uncertain coupled chaotic delayed FitzHugh-Nagumo (FHN) neurons under EES for incorporated parametric variations. A global nonlinear control law for synchronization of delayed neurons with known parameters is developed. Based on local and global Lipschitz conditions, knowledge of the bounds on the neuronal states, the Lyapunov-Krasovskii functional, and theL2gain reduction, a less conservative local robust nonlinear control law is formulated to address the problem of robust asymptotic synchronization of delayed FHN neurons under parametric uncertainties. The proposed local control law guarantees both robust stability and robust performance and provides theL2bound for uncertainty rejection in the synchronization error dynamics. Separate conditions for single-input and multiple-input control schemes for synchronization of a wide class of FHN systems are provided. The results of the proposed techniques are verified through numerical simulations.

New Approach for Software Modeling and Transformation

2012 ◽  
Vol 195-196 ◽  
pp. 829-833
Author(s):  
Jin Wei Yu
Keyword(s):  
User Interface ◽  
Expressive Power ◽  
Basic Element ◽  
Static Model ◽  
Software Modeling ◽  
New Approach ◽  
Control Power ◽  
Power And Control ◽  
Action Model ◽  
And Control

In this paper, a new kind of presentation model for software modeling and transformation is proposed, which is composed of three parts: static model, action model and presentation model. Presentation model describes user interface appearance thorough, while interface template describes the macro-layout and relation of interface, whose basic element is interactive object. Interface template-based presentation model can enhance the rationality of macro-layout of the interface, enhance the expressive power and control power, meet the requirement of auto generate high quality user interface. This solution can be used widely for suffering little from the domain and some special techniques of target applications.

scholarly journals Fluctuation-induced distributed resonances in oscillatory networks

2019 ◽  
Vol 5 (7) ◽  
pp. eaav1027 ◽  
Author(s):  
Xiaozhu Zhang ◽  
Sarah Hallerberg ◽  
Moritz Matthiae ◽  
Dirk Witthaut ◽  
Marc Timme
Keyword(s):  
Dynamic Network ◽  
Intermediate Frequency ◽  
Response Patterns ◽  
Low Frequencies ◽  
High Frequencies ◽  
Self Organized ◽  
Oscillatory Networks ◽  
Input Signals ◽  
Induce Response ◽  
And Control

Across physics, biology, and engineering, the collective dynamics of oscillatory networks often evolve into self-organized operating states. How such networks respond to external fluctuating signals fundamentally underlies their function, yet is not well understood. Here, we present a theory of dynamic network response patterns and reveal how distributed resonance patterns emerge in oscillatory networks once the dynamics of the oscillatory units become more than one-dimensional. The network resonances are topology specific and emerge at an intermediate frequency content of the input signals, between global yet homogeneous responses at low frequencies and localized responses at high frequencies. Our analysis reveals why these patterns arise and where in the network they are most prominent. These results may thus provide general theoretical insights into how fluctuating signals induce response patterns in networked systems and simultaneously help to develop practical guiding principles for real-world network design and control.

Modeling of a Dynamic Mirror With Antagonistic Piezoelectric Stack Actuation

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
James A. Mynderse ◽  
George T. C. Chiu
Keyword(s):  
Constitutive Models ◽  
Open Loop ◽  
Step Response ◽  
Experimental Frequency ◽  
Loop Control ◽  
Response Data ◽  
Input Control ◽  
Proposed Model ◽  
Single Input ◽  
Charging Dynamics

A dynamic mirror actuator utilizing antagonistic piezoelectric stack actuators is presented for use in laser printers. Exhibiting hysteresis and other nonlinearities in open-loop operation, the dynamic mirror actuator (DMA) requires a control structure to achieve accurate mirror positioning. A linear DMA model is developed for extending operational bandwidth under closed-loop control, employing explicit piezoelectric stack actuator (PESA) charging dynamics and incorporating two modes for single input control of opposing PESA drives. Compared to constitutive models from literature, the proposed model displays a comparable fit with experimental frequency response data while retaining a lower model order. As further validation, simulated step response data are shown to agree with experimental data.

scholarly journals UPRAVLJANJE RIZICIMA I INTERNA REVIZIJA

2021 ◽  
Vol 9 (1) ◽  
pp. 48-57
Author(s):  
Zorica Jović
Keyword(s):  
Risk Management ◽  
Internal Audit ◽  
Basic Element ◽  
Security Measures ◽  
Management Framework ◽  
Internal Auditors ◽  
Consulting Services ◽  
Risk Management Framework ◽  
Enterprise Risk ◽  
And Control

People undertake risk management activities to identify, assess, manage, and control all types of events or situations. This can range from a single project or narrowly defined types of risk, for example, market risk, to the threats and opportunities faced by the organization. Organizations are under pressure to identify all business risks they face - social, ethical, and environmental risks as well as financial and operational - and to explain that they are being managed at an acceptable level. Risk management is a basic element of corporate governance. Management is responsible for establishing and operating the risk management framework on behalf of the board. A company's risk management brings many benefits that result from its structured, consistent, and coordinated approach. The key role of internal auditors concerning enterprise risk management should be to assure the effectiveness of risk management to management. When an internal audit extends its activities beyond this key role, it should apply certain security measures, including treating engagements as consulting services and applying all relevant standards. In this way, an internal audit will protect its independence and the objectivity of its assurance services

Fractional High-Order Differential Estimator and Feedback Controller Design for a Single-Input–Single-Output Affine Chaotic System

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Erdinc Sahin ◽  
Mustafa Sinasi Ayas
Keyword(s):  
Chaotic System ◽  
High Order ◽  
Feedback Controller ◽  
Control Problems ◽  
Single Input Single Output ◽  
Single Output ◽  
System Output ◽  
Single Input ◽  
Estimation And Control ◽  
And Control

Abstract Control of chaos generally refers to realize a desired behavior of chaotic system output and its states. In this manner, we design a fractional high-order differential feedback controller (FHODFC) to increase tracking performance of a nonlinear system output and its differentials for a desired trajectory signal. The proposed controller is based on fractional calculus and high-order extracted differentials of error signal. The suggested fractional approach is applied to a single-input–single-output affine Duffing-Holmes dynamical system in matlab/simulink environment. Duffing-Holmes system is analyzed for two different problems: estimation and control problems. The simulation results clearly demonstrate superior dynamic behavior of the FHODFC compared to the classical high-order differential feedback controller (HODFC) version for both estimation and control problems.

Dynamic logarithmic state and control quantization for continuous-time linear systems

Robotica ◽  
2022 ◽  
pp. 1-16
Author(s):  
Jiashuo Wang ◽  
Shuo Pan ◽  
Zhiyu Xi
Keyword(s):  
Feedback Control ◽  
Linear System ◽  
Linear Systems ◽  
Continuous Time ◽  
Control Law ◽  
Quantized Feedback ◽  
Single Input ◽  
Simulation Results ◽  
And Control ◽  
Time Linear

Abstract This paper addresses logarithmic quantizers with dynamic sensitivity design for continuous-time linear systems with a quantized feedback control law. The dynamics of state quantization and control quantization sensitivities during “zoom-in”/“zoom-out” stages are proposed. Dwell times of the dynamic sensitivities are co-designed. It is shown that with the proposed algorithm, a single-input continuous-time linear system can be stabilized by quantized feedback control via adopting sensitivity varying algorithm under certain assumptions. Also, the advantage of logarithmic quantization is sustained while achieving stability. Simulation results are provided to verify the theoretical analysis.

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