scholarly journals Krotov: A Python implementation of Krotov's method for quantum optimal control

2019 ◽  
Vol 7 (6) ◽  
Author(s):  
Michael Goerz ◽  
Daniel Basilewitsch ◽  
Fernando Gago-Encinas ◽  
Matthias G. Krauss ◽  
Karl P. Horn ◽  
...  
Keyword(s):  
Optimal Control ◽  
Quantum Control ◽  
Control Method ◽  
Optimization Methods ◽  
Continuous Control ◽  
Wide Range ◽  
Quantum Optimal Control ◽  
Monotonic Convergence ◽  
Krotov’S Method ◽  
High Level

We present a new open-source Python package, krotov, implementing the quantum optimal control method of that name. It allows to determine time-dependent external fields for a wide range of quantum control problems, including state-to-state transfer, quantum gate implementation and optimization towards an arbitrary perfect entangler. Krotov's method compares to other gradient-based optimization methods such as gradient-ascent and guarantees monotonic convergence for approximately time-continuous control fields. The user-friendly interface allows for combination with other Python packages, and thus high-level customization.

scholarly journals Quantum Optimal Control for Bose-Einstein-Condensates at Complex Space

2021 ◽  
Author(s):  
Quan-Fang Wang
Keyword(s):  
Optimal Control ◽  
Hilbert Spaces ◽  
Schrodinger Equation ◽  
Quantum Control ◽  
Complex Space ◽  
Pitaevskii Equation ◽  
Interesting Topic ◽  
Quantum Optimal Control ◽  
Control Target ◽  
Bose Einstein

Quantum control of Bose-Einstein-Condensates is interesting topic in the areas of control and physics. In this work, Gross-Pitaevskii equation expressed Bose-Einstein-Condensates is considered as control target. Full theoretical proof for the existence of quantum optimal control is provided for cubical Schrodinger equation in complex Hilbert spaces.

scholarly journals Quantum Control for Neutrons in Nuclear Reaction

2021 ◽  
Author(s):  
Quan-Fang Wang
Keyword(s):  
Optimal Control ◽  
Variational Method ◽  
Control Theory ◽  
Nuclear Reaction ◽  
Quantum Control ◽  
Many Body ◽  
Chain Reaction ◽  
Quantum Optimal Control ◽  
Full Proof

Quantum control of neutrons in nuclear reaction in considered in this work. Neutrons fission from uranium <sup>235</sup>U of chain reaction is interested to be controlled as target theoretically. Control theory is applied to interacted many-body neutrons collision in the framework of variational method. Full proof is provided for quantum optimal control of scattered poly-neutrons.

scholarly journals Study on maintaining formations during satellite formation flying based on SDRE and LQR

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 394-399 ◽  
Author(s):  
Zhang Ke ◽  
He Zhenqi ◽  
Lv Meibo
Keyword(s):  
Optimal Control ◽  
Control Algorithm ◽  
Formation Flying ◽  
Control Method ◽  
Process Time ◽  
Engineering Practice ◽  
Continuous Control ◽  
Linear Quadratic ◽  
Orbit Element ◽  
Lqr Controller

AbstractDue to the influence of various perturbations of space, satellites flying in formation cannot maintain specific configurations for long durations [1, 2]. In order to ensure that formation configurations are able to meet the requirements of space missions, it is important to maintain control of formation configurations. This is an urgent problem to be solved. The traditional control method for controlling formations is based on the average orbit element, and uses the assumption that the average orbit element deviation and the instantaneous orbit element deviation are approximately equal. However, the continuous control system is more difficult to achieve in engineering practice. Using a LQR (linear quadratic regulator) optimal control algorithm and SDRE (state-dependent Riccati equation) optimal control algorithm to maintain the formation flying [3, 4]. Through simulation, it was found that when using the SDRE controller in the system transition process time is shorter than when the LQR controller is used, and fuel consumption is less for the SDRE controller than for the LQR controller.

scholarly journals Chaos Control in Mechanical Systems

2006 ◽  
Vol 13 (4-5) ◽  
pp. 301-314 ◽  
Author(s):  
Marcelo A. Savi ◽  
Francisco Heitor I. Pereira-Pinto ◽  
Armando M. Ferreira
Keyword(s):  
Chaos Control ◽  
Control Method ◽  
Chaotic Behavior ◽  
Mechanical Systems ◽  
Control Technique ◽  
Continuous Control ◽  
State Variables ◽  
Unstable Periodic Orbits ◽  
State Observers ◽  
Wide Range

Chaos has an intrinsically richness related to its structure and, because of that, there are benefits for a natural system of adopting chaotic regimes with their wide range of potential behaviors. Under this condition, the system may quickly react to some new situation, changing conditions and their response. Therefore, chaos and many regulatory mechanisms control the dynamics of living systems, conferring a great flexibility to the system. Inspired by nature, the idea that chaotic behavior may be controlled by small perturbations of some physical parameter is making this kind of behavior to be desirable in different applications. Mechanical systems constitute a class of system where it is possible to exploit these ideas. Chaos control usually involves two steps. In the first, unstable periodic orbits (UPOs) that are embedded in the chaotic set are identified. After that, a control technique is employed in order to stabilize a desirable orbit. This contribution employs the close-return method to identify UPOs and a semi-continuous control method, which is built up on the OGY method, to stabilize some desirable UPO. As an application to a mechanical system, a nonlinear pendulum is considered and, based on parameters obtained from an experimental setup, analyses are carried out. Signals are generated by numerical integration of the mathematical model and two different situations are treated. Firstly, it is assumed that all state variables are available. After that, the analysis is done from scalar time series and therefore, it is important to evaluate the effect of state space reconstruction. Delay coordinates method and extended state observers are employed with this aim. Results show situations where these techniques may be used to control chaos in mechanical systems.

Semi-Active Reduction of Vibrations of Periodically Oscillating System

2016 ◽  
Vol 248 ◽  
pp. 111-118 ◽  
Author(s):  
Maciej Michajłow ◽  
Tomasz Szolc ◽  
Łukasz Jankowski ◽  
Robert Konowrocki
Keyword(s):  
Optimal Control ◽  
Steady State ◽  
Control Strategy ◽  
Control Method ◽  
Active Damping ◽  
Problem Solution ◽  
Control Methods ◽  
Typical Application ◽  
Stable Position ◽  
Wide Range

Periodical vibrations are common phenomenon affecting a wide range of mechanical systems. Most frequently it affects machines designed to work in a steady-state conditions like: turbine, pump, rail vehicle, etc. In those kinds of machines it is always possible to decompose the system motion to basic average-speed constant component and oscillatory component. Usually the second term is treated as undesirable and various techniques are applied in order to minimize it as far as it is possible. These techniques refers to both the hardware selection – meaning the type of damping system (active, semi-active, passive) and the control method selection – meaning the damping system control method. Concerning the control methods, there are many algorithms available in literature devoted to transient systems. One of typical application is to use them in systems experiencing sudden, external force excitation. After destabilization of the system, caused by excitation, the role of the control algorithm is to restore the system stable position and additionally to reach the extreme of some additional criterion. Typical criterions are minimization of the time, of restoring the stable position, minimizing the consumed control energy, etc. On the other hand, considering the steady-state systems, especially based on semi-active damping elements, there are not so many control methods available.This paper focuses on developing the proper methodology for deriving the optimal control strategy of semi-active damping element, to be used in periodically vibrating mechanical system. The control strategy is developed on the basis of the Optimal Control Theory. Numerical computations are involved in order to solve the optimal control problem for the considered test system. Problem solution reveals the periodical nature of optimal control function.

scholarly journals Quantum Optimal Control for Bose-Einstein-Condensates at Complex Space

2021 ◽  
Author(s):  
Quan-Fang Wang
Keyword(s):  
Optimal Control ◽  
Hilbert Spaces ◽  
Schrodinger Equation ◽  
Quantum Control ◽  
Complex Space ◽  
Pitaevskii Equation ◽  
Interesting Topic ◽  
Quantum Optimal Control ◽  
Control Target ◽  
Bose Einstein

Quantum control of Bose-Einstein-Condensates is interesting topic in the areas of control and physics. In this work, Gross-Pitaevskii equation expressed Bose-Einstein-Condensates is considered as control target. Full theoretical proof for the existence of quantum optimal control is provided for cubical Schrodinger equation in complex Hilbert spaces.

scholarly journals Quantum Control for Neutrons in Nuclear Reaction

2021 ◽  
Author(s):  
Quan-Fang Wang
Keyword(s):  
Optimal Control ◽  
Variational Method ◽  
Control Theory ◽  
Nuclear Reaction ◽  
Quantum Control ◽  
Many Body ◽  
Chain Reaction ◽  
Quantum Optimal Control ◽  
Full Proof

Quantum control of neutrons in nuclear reaction in considered in this work. Neutrons fission from uranium <sup>235</sup>U of chain reaction is interested to be controlled as target theoretically. Control theory is applied to interacted many-body neutrons collision in the framework of variational method. Full proof is provided for quantum optimal control of scattered poly-neutrons.

Modeling and Optimal Control of Distributed Generation Systems for Demand and Energy Management

2009 ◽  
Author(s):  
Andrew J. Yosten ◽  
Gregor P. Henze
Keyword(s):  
Optimal Control ◽  
Objective Function ◽  
Distributed Generation ◽  
Care Center ◽  
Load Ratio ◽  
Mixed Integer ◽  
Continuous Control ◽  
Objective Functions ◽  
Part Load ◽  
Wide Range

A procedure for the simplified modeling of distributed generation (DG) systems and finding optimal control and dispatch schedules is presented. Mixed integer linear programming can be used to develop optimized equipment dispatch schedules for a wide range of constraints and objective functions. For the monetary objective function considered in this study, optimal control of distributed generation equipment can reduce operating costs by reducing the amount of energy purchased from the grid, reducing demand charges, and reducing the heating energy cost through the implementation of a CHP plant. The procedure can easily be modified for alternative objective functions considering site energy, primary energy, or emissions and the resultant dispatch schedules used to derive operational guidelines. Moreover, a wide range of operational constraints can be modeled. Results are presented for a healthcare outpatient care center in Richmond, Indiana for the cases of single-day and multi-day demand management using on/off control of emergency generation equipment, continuous control of the emergency generation equipment between a nonzero minimum and a maximum part-load ratio, and combined heat and power systems with thermal storage. Nonlinearities in the objective function due to demand charges or nonzero lower bounds on the part-load operation of the DG equipment have been avoided by properly formulating substitute problems. The emphasis of this article is on the model development process rather than the specific dispatch schedules generated.

The way of value of Correlation of genomic DNA microsatellite loci and live weight of Chukchi reindeer

2020 ◽  
pp. 27-32
Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova
Keyword(s):  
Microsatellite Markers ◽  
Agricultural Production ◽  
Live Weight ◽  
Biodiversity Loss ◽  
Tribal Community ◽  
High Germination ◽  
Wide Range ◽  
The Mean ◽  
High Level ◽  
Dna Microsatellite

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.

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