Science topics: Applied MathematicsOptimization
Science topic
Optimization - Science topic
Explore the latest questions and answers in Optimization, and find Optimization experts.
Questions related to Optimization
Transient analysis in electrical engineering is the study of circuit behavior during the short period immediately after a sudden change, such as switching, faults, or the application/removal of sources. During this interval, the circuit has not yet reached its steady state; instead, voltages and currents vary rapidly due to energy stored in inductors and capacitors. Understanding these transients is crucial for designing stable, reliable, and safe electrical and electronic systems.
1. Introduction:-
Electrical circuits containing reactive components—inductors (L) and capacitors (C)—store energy. When the circuit is switched on or off, or when a disturbance occurs, this stored energy creates temporary responses called transients. The study of how voltages and currents behave during this short time is called transient analysis.
Transient behavior typically lasts only a few milliseconds but can reach dangerous values if not controlled. Engineers analyze transients to ensure systems can withstand sudden changes without failure.
2. Causes of Transients:-
Electrical transients occur whenever there is a sudden change in circuit conditions. Common causes include:
2.1 Switching Operations
• Connecting or disconnecting loads
• Starting motors
• Switching transformers
2.2 Faults in Power Systems
• Short circuits
• Line interruptions
• Lightning strikes causing voltage surges
2.3 Load Variations
• Sudden changes in consumer demand
• Inrush current during energization of inductors/transformers
2.4 Electronic Switching
• Transistors and MOSFETs switching at high speed
• Digital logic transitions
3. Energy Storage Elements and Their Role:-
Reactive elements cause transients because they resist sudden changes:
3.1 Capacitors
• Store energy in electric fields
• Voltage across a capacitor cannot change instantaneously
i = C *dv/dt
3.2 Inductors
• Store energy in magnetic fields
• Current through an inductor cannot change instantaneously
v = L *di/dt
These fundamental properties lead to exponential or oscillatory behavior during transient conditions.
4. Types of Transient Responses:-
4.1 First-Order Transients
Circuits with one energy-storage element (RC or RL).
RC Charging Example:
📷
RL Current Growth Example:
📷
Time Constant (τ):
• RC circuit: τ = RC
• RL circuit: τ = L/R
After 5τ, the transient is considered practically over.
4.2 Second-Order Transients
Circuits with two energy-storage elements (RLC circuits).
Depending on damping (ζ), response may be:
• Underdamped: Oscillatory decay
• Critically damped: Fastest non-oscillatory response
• Overdamped: Slow decay without oscillation
General form:
📷
Where:
• alpha = damping factor
• omega_d = damped natural frequency
5. Methods of Transient Analysis:-
5.1 Classical Differential Equation Method
• Apply KVL or KCL
• Form differential equations
• Solve using initial conditions
5.2 Laplace Transform Method
Most widely used because it:
• Converts differential equations into algebraic equations
• Easily incorporates initial conditions
• Simplifies complex circuits
The final solution is obtained by inverse Laplace transform.
5.3 Simulation-Based Analysis:-
Software tools include:
• PSpice / LTspice
• MATLAB/Simulink
• Multisim
• EMTP (Electromagnetic Transients Program)
Simulations allow detailed modeling of nonlinear components and power systems.
6. Applications of Transient Analysis:-
Transient analysis is vital across many areas of electrical engineering:
6.1 Power Systems
• Fault current calculations
• Transformer inrush current
• Lightning surge analysis
• Switching overvoltages
6.2 Electronics
• MOSFET and BJT switching
• Digital circuit timing and delays
• Pulse response of filters
6.3 Communication Systems
• Pulse shaping
• Rise/fall time analysis
• Transient behavior in transmission lines
6.4 Electric Drives
• Motor startup currents
• Torque and speed transients
6.5 Protection Systems
• Relay response
• Surge arresters
• Circuit breaker operation
7. Importance of Transient Analysis:-
Transient analysis helps engineers:
• Predict high currents/voltages during sudden changes
• Prevent damage to equipment
• Design stable circuits
• Optimize switching performance
• Ensure safety during abnormal system conditions
In power systems, insufficient transient understanding can cause outages or equipment failure. In electronics, it affects speed, reliability, and signal integrity.
8. Conclusion:-
Transient analysis is a cornerstone of electrical engineering, providing essential insights into the short-term behavior of circuits and systems after sudden changes. By understanding how capacitors, inductors, and entire networks respond during this critical period, engineers can design safer, more efficient, and more reliable systems. Whether analyzing switching surges in power lines or timing behavior in microchips, transient analysis remains vital across all electrical engineering domains.
9.MATLAB CODE:-
% ============================================================
% TRANSIENT ANALYSIS MENU-DRIVEN MATLAB PROGRAM
% ============================================================
clc;
clear;
while true
disp('====================================================');
disp(' TRANSIENT ANALYSIS MENU');
disp('====================================================');
disp('1. RC Charging Transient');
disp('2. RL Current Growth Transient');
disp('3. RLC Step Response (Underdamped / Overdamped / Critically Damped)');
disp('4. Exit');
disp('====================================================');
choice = input('Enter your choice: ');
switch choice
% ====================================================
% RC CHARGING
% ====================================================
case 1
clc;
disp('--- RC Charging Transient ---');
R = input('Enter resistance R (ohms): ');
C = input('Enter capacitance C (farads): ');
Vs = input('Enter supply voltage Vs (volts): ');
tau = R*C;
t = linspace(0, 5*tau, 500);
vC = Vs * (1 - exp(-t/tau));
fprintf('\nTime constant tau = %.6f seconds\n\n', tau);
figure;
plot(t, vC, 'LineWidth', 2);
xlabel('Time (s)');
ylabel('v_C(t) (V)');
title('RC Charging Transient');
grid on;
% ====================================================
% RL CURRENT GROWTH
% ====================================================
case 2
clc;
disp('--- RL Current Growth Transient ---');
R = input('Enter resistance R (ohms): ');
L = input('Enter inductance L (henry): ');
Vs = input('Enter supply voltage Vs (volts): ');
tau = L/R;
I_inf = Vs / R;
t = linspace(0, 5*tau, 500);
i = I_inf * (1 - exp(-t/tau));
fprintf('\nTime constant tau = %.6f seconds\n', tau);
fprintf('Steady-state current I∞ = %.4f A\n\n', I_inf);
figure;
plot(t, i, 'LineWidth', 2);
xlabel('Time (s)');
ylabel('i(t) (A)');
title('RL Current Growth Transient');
grid on;
% ====================================================
% RLC TRANSIENT
% ====================================================
case 3
clc;
disp('--- RLC Step Response ---');
R = input('Enter resistance R (ohms): ');
L = input('Enter inductance L (henry): ');
C = input('Enter capacitance C (farads): ');
Vs = input('Enter supply voltage Vs (volts): ');
t_end = input('Enter simulation time (seconds): ');
% Natural frequency & damping ratio
wn = 1 / sqrt(L*C);
zeta = R / (2*L*wn);
fprintf('\nNatural freq (wn) = %.4f rad/s\n', wn);
fprintf('Damping ratio (zeta) = %.4f\n', zeta);
if zeta < 1
disp('System is UNDERDAMPED.');
elseif zeta == 1
disp('System is CRITICALLY DAMPED.');
else
disp('System is OVERDAMPED.');
end
% Differential equations
f = @(t, x) [
(Vs - R*x(1) - x(2)) / L; % di/dt
x(1) / C % dvC/dt
];
[t, x] = ode45(f, [0 t_end], [0 0]);
i = x(:,1);
vC = x(:,2);
% Plot results
figure;
subplot(2,1,1);
plot(t, i, 'LineWidth', 2);
xlabel('Time (s)');
ylabel('i(t) (A)');
title('RLC Current Response');
grid on;
subplot(2,1,2);
plot(t, vC, 'LineWidth', 2);
xlabel('Time (s)');
ylabel('v_C(t) (V)');
title('RLC Capacitor Voltage Response');
grid on;
% ====================================================
% EXIT PROGRAM
% ====================================================
case 4
clc;
disp('Exiting program...');
break;
otherwise
disp('Invalid choice! Please select 1–4.');
end
end
10.References:-
[1] C. K. Alexander and M. N. O. Sadiku, Fundamentals of Electric Circuits, 6th ed. New York, NY, USA: McGraw-Hill, 2017.
[2] W. H. Hayt, J. E. Kemmerly, and S. M. Durbin, Engineering Circuit Analysis, 9th ed. New York, NY, USA: McGraw-Hill, 2019.
[3] J. W. Nilsson and S. A. Riedel, Electric Circuits, 11th ed. Boston, MA, USA: Pearson, 2019.
[4] A. S. Pabla, Electric Power Distribution, 6th ed. New Delhi, India: McGraw-Hill Education, 2018.
[5] P. Kundur, Power System Stability and Control. New York, NY, USA: McGraw-Hill, 1994.
[6] IEEE Power and Energy Society, IEEE Std C62.41: Recommended Practice on Surge Voltages in Low-Voltage AC Power Circuits, 2016.
[7] L. O. Chua, C. A. Desoer, and E. S. Kuh, Linear and Nonlinear Circuits. New York, NY, USA: McGraw-Hill, 1987.
[8] S. Franco, Electric Circuit Fundamentals, 3rd ed. Boston, MA, USA: Oxford University Press, 2015.
[9] MIT OpenCourseWare, “Circuits and Electronics.” Available: https://ocw.mit.edu
[10] A. Greenwood, Electrical Transients in Power Systems. New York, NY, USA: Wiley-IEEE Press, 1991.

Optimization: What novel methods can be developed to solve large-scale non-convex optimization problems efficiently?
E2MAR (Energy-Efficient Multi-hop Algorithm for Reliable Routing) is a specialized protocol designed for underwater wireless sensor networks (UWSNs), which are integral to the Internet of Underwater Things (IoUT). Its operation focuses on overcoming the challenges of underwater communication, such as high energy consumption, limited bandwidth, and the unreliability of acoustic communication. Here’s how E2MAR works within the IoUT ecosystem:
1. Multi-hop Communication in IoUT
E2MAR uses a multi-hop communication strategy, where data is transmitted through a series of intermediate nodes instead of a direct path. This approach helps:
- Reduce energy consumption by avoiding long-distance transmissions.
- Improve communication reliability in underwater environments where signals degrade over distance.
2. Energy Efficiency
- Node Selection Based on Residual Energy: E2MAR selects relay nodes based on their remaining energy levels. Nodes with higher energy are prioritized, ensuring network longevity.
- Load Balancing: By distributing the communication workload among multiple nodes, E2MAR prevents energy depletion in specific nodes, avoiding network partitioning.
3. Reliability in Data Transmission
- Adaptive Path Selection: E2MAR adapts to dynamic underwater conditions (e.g., mobility of nodes, water currents) by selecting the most reliable paths based on node stability and link quality.
- Error Correction: The protocol may include mechanisms for detecting and correcting errors, mitigating the impact of packet loss common in underwater communication.
4. Minimizing Acoustic Channel Limitations
- Reduced Interference: By carefully scheduling transmissions, E2MAR reduces collisions and interference, which are common in underwater acoustic channels.
- Optimized Routing Paths: It avoids paths with high signal attenuation or noise, leveraging environmental knowledge for better performance.
5. Scalability and Adaptability
- E2MAR can scale to support large IoUT deployments, such as those for oceanographic monitoring, underwater surveillance, and resource exploration.
- The protocol adapts to varying densities of nodes and network topology changes, maintaining efficient operation in dynamic underwater environments.
Applications in IoUT
- Environmental Monitoring: E2MAR ensures reliable, energy-efficient data collection from underwater sensors monitoring parameters like temperature, salinity, or pollution.
- Disaster Management: Used in tsunami detection or oil spill monitoring networks, E2MAR provides reliable routing for critical data.
- Underwater Surveillance: Helps in securing underwater assets and monitoring marine life with minimal energy overhead.
Challenges and Future Directions
While E2MAR enhances IoUT by improving energy efficiency and reliability, there are areas for further improvement:
- Integration with AI: To enhance decision-making in dynamic environments.
- Hybrid Communication: Combining acoustic, optical, and electromagnetic waves for more robust performance.
- Security Enhancements: Incorporating secure routing to counter cyber threats in IoUT.
E2MAR (Energy-Efficient Multi-hop Algorithm for Reliable Routing) is a protocol designed for underwater wireless sensor networks, vital to the Internet of Underwater Things (IoUT). It enhances energy efficiency by selecting relay nodes based on residual energy and balancing communication loads. Using multi-hop transmission, it ensures reliable data transfer, adapts to dynamic underwater conditions, and minimizes acoustic channel limitations like interference and signal attenuation. Scalable and adaptable, E2MAR supports large IoUT networks for applications in environmental monitoring, disaster management, and underwater surveillance. Future improvements include integrating AI, hybrid communication methods, and enhanced security for better performance and resilience in underwater environments
Optimization of Energy Consumption in Electric Arc Furnace Steelmaking.
I am trying to establish an inflammatory injury model in HK-2 cells using LPS stimulation, but I've encountered some issues.
I treated the HK-2 cells with a range of LPS concentrations (0, 1, 2, 5, 10, 20, and 50 µg/ml) in 1% FBS medium for 24 hours. However, the CCK-8 assay showed no significant differences in cell viability across the groups.
Has anyone encountered a similar situation, or does anyone have suggestions on optimizing the model? Could it be related to serum concentration, LPS batch, or cell sensitivity?
I am trying to optimize an molecule containing C, H and O by using gaussian 09. Parameters which are mentioned in .com file are mentioned below:
%Chk=./vac_A_vac.chk
%RWF=./vac_A_vac.rwf
%Int=./vac_A_vac.int
%D2E=./vac_A_vac.d2e
%Mem=256MW
%NProcShared=16
#P B3LYP/6-31G(d,p) Opt(ModRedundant,MaxCycles=999) Pop=Full NoSymm ROHF
Geo_Optimization GeoOpt_vac_A_vac
Unfortunately the job has been terminated with showing the following error
Error in internal coordinate system.
Error termination via Lnk1e in /usr/local/g09/l103.exe at Mon Dec 2 16:35:01 2019.
Please help me to solve the problem.
Formability Analysis of AA3003O by Optimizing Processing Parameters in Single Point Incremental Forming
Above is my paper, please see it and do the needful as soon as possible

(E1U) (E2G) (E2G) (B2U) (A1G) (E1U) (E1U) (E2G)
(E2G) (B2U)
Requested convergence on RMS density matrix=1.00D-08 within 128 cycles.
Requested convergence on MAX density matrix=1.00D-06.
Requested convergence on energy=1.00D-06.
No special actions if energy rises.
SCF Done: E(RB3LYP) = -13319.3349271 A.U. after 1 cycles
Convg = 0.2232D-08 -V/T = 2.0097
Range of M.O.s used for correlation: 1 5424
NBasis= 5424 NAE= 1116 NBE= 1116 NFC= 0 NFV= 0
NROrb= 5424 NOA= 1116 NOB= 1116 NVA= 4308 NVB= 4308
PrsmSu: requested number of processors reduced to: 4 ShMem 1 Linda.
PrsmSu: requested number of processors reduced to: 1 ShMem 1 Linda.
PrsmSu: requested number of processors reduced to: 1 ShMem 1 Linda.
PrsmSu: requested number of processors reduced to: 1 ShMem 1 Linda.I
.
.
.
PrsmSu: requested number of processors reduced to: 1 ShMem 1 Linda.
PrsmSu: requested number of processors reduced to: 1 ShMem 1 Linda.
Symmetrizing basis deriv contribution to polar:
IMax=3 JMax=2 DiffMx= 0.00D+00
G2DrvN: will do 1 centers at a time, making 529 passes doing MaxLOS=2.
Estimated number of processors is: 3
Calling FoFCou, ICntrl= 3107 FMM=T I1Cent= 0 AccDes= 0.00D+00.
Calling FoFCou, ICntrl= 3107 FMM=T I1Cent= 0 AccDes= 0.00D+00.
CoulSu: requested number of processors reduced to: 4 ShMem 1 Linda.
Calling FoFCou, ICntrl= 3107 FMM=T I1Cent= 0 AccDes= 0.00D+00.
CoulSu: requested number of processors reduced to: 4 ShMem 1 Linda.
.
.
.
Calling FoFCou, ICntrl= 3107 FMM=T I1Cent= 0 AccDes= 0.00D+00.
CoulSu: requested number of processors reduced to: 4 ShMem 1 Linda.
Erroneous write. Write 898609344 instead of 2097152000.
fd = 4
orig len = 3177921600 left = 3177921600
g_write
I performed the opt + freq in xtb using the following keyword: ''--ohess --alpb water" the optimization ran fine with NO message like this one:
########################################################################
# WARNING! Some non-fatal runtime exceptions were caught, please check:
# - Hessian on incompletely optimized geometry!
########################################################################
So i thought that my structure was correctly optimized, but when I open the g98.out file i noticed a small negative frequencies, so should I reoptimized my compound or is this a numerical issue ?
Thanks
Alessio
Hello everyone , please I have problem in my calculations using gaussian, I always have the same error.
Error termination in NtrErr: NtrErr called from fileIO.
PPp

Hi I'm using a dynamic programming tool for my research written in matlab.
However I want to shift my work in python, is it available a open source dynamic programming tool in python?
Where I can find it?
I need to implement a problem defined by 400 lines of code featured by 5 state variables, 4 output variables and 20 input time series.
Thanks!
"How can I ensure that my RTX 3090 GPU on a supercomputer is fully utilized for Abaqus 2023 simulations? Despite configuring the system, it seems the GPU is not under significant load during the simulation. What steps should I take to optimize Abaqus to leverage the full power of my GPU?"
I'm trying to optimize Vanadium atom for formation energy calculation, but there is a convergence problem.
I set the optimization steps to 2000 and electron_maxstep = 2000, but I don't know where the issue lies, and I am new to this.
I added input and output files.
Thanks for your help
Improving Thermal Energy Storage in Solar Collectors: A Study of iron Oxide Nanoparticles and Flow Rate Optimization
So my research is about primer design for plant pathogent bacteriophage (especially: Xanthomonas oryzae phage). I am using tail fiber gene target, because that area is more conserved than their capsid or DNA polymerase (I analyzed it using Mega X). I made my primer using Primer3Plus, Primer3Web, and Primer Blast NCBI (I used reference seq from NCBI).
So here is the problem after I'm using my own primer..
At first attempt doing the PCR, I am using the PCRMix protocol and using the everage Tm temperature of my primer as annealing temperature. One of my sample DNA showed poorly results but the DNA is showsed as multiband under the UV transilluminator (I'm not sure but I think it's a good sign)..
I used around 57°C annealing temperature. At that time I thought my primer is probably works.. 🤔 I'm so confused not even one sample is positive after doing the optimalization
Can someone please help me to correct my steps..
please show me which one is wrong or kindly explain the correct way to make a design primer😭
I would be really thankful for your help..
Dear Colleagues,
I hope this message finds you well. I am working on a research project involving the development of a Mixed-Integer Linear Programming (MILP) model for optimizing quality-based supply chain management, particularly focusing on managing the deterioration of perishable food items.
I have written the preliminary LINGO code for this model, but unfortunately, it is not functioning as expected. The variable values (solutions) are incorrect or not converging as anticipated, and despite my best efforts, I am unable to resolve the issue.
I am genuinely seeking help from someone with expertise in MILP modeling and supply chain optimization who can assist me in debugging and improving the code. Your contribution would be highly valuable, and in recognition of your efforts, I would be more than happy to offer co-authorship on the paper once the work is successfully completed.
If you are willing to help or guide me through the corrections, please do not hesitate to reach out. I would greatly appreciate any advice or support.
Looking forward to your response.
Best regards,
Ashish Kumar
I am experiencing challenges culturing Human Umbilical Vein Endothelial Cells (HUVEC) and seeking advice for optimization.
Observations:
- Slow growth rate: My HUVEC cells exhibit a slow growth rate, reaching only around 5 million cells in an 80% confluent T75 flask.
- Altered cell morphology: I have observed changes in cell shape between passages 5 and 18, as evidenced by the attached images for both passages.
Question:
- Passage number determination: Does the passage number start counting after thawing HUVECs from liquid nitrogen or upon initial plating after isolation?
- Optimization strategies: Based on the observations described above, I would appreciate any suggestions or recommendations for optimizing HUVEC cell culture, particularly regarding: Improving growth rate and cell yield?


I would like to inquire about the theory titled ‘Geometric Mean Optimizer for Solving a Problem of a Real-Life Embedded System Application.’ Any information, no matter how small, would be greatly appreciated.
I got an problem solving a MIQCP: I want to cut my feaseable region into to spaces with a quadratical constraints (half circle). For points inside my half circle there is no problem, but the area outsid is a non-convex one. I use disjunctive programming to activite only one of the constraints. Is there any way to solve such a problem with Cplex in Matlab (cplexmiqcp())? Would be very grathefull if someone have experience with such a problem and can share his knowledge with me :)
Best regards,
Jannik
I made a DesignBuilder model that includes PV solar collectors using two electric load centers. After simulation, the annual PV generation was about + 3700 KWh.
Then, I identified an optimization problem with two objectives (minimize thermal discomfort and maximize PV electricity generation). The decision variables are windows ratios, wall materials, and building rotation, while any parameters related to PV solar collectors design are kept constant.
In the optimization results, the power generation values are negative. Consequently, the optimum design scenarios and the pareto front are misleading.
I am optimizing a multi-stage optimization model for disaster response relief delivery. In this regard, I want to know the realistic values of cost parameters related to the operating and setup costs of temporary relief logistics facilities.
Can anyone guide me what are the realistic ranges of these costs, and how they are related to each other, and with the capacity of temporary relief facilities?
Also, please comment on the effect of the planning horizon's length on these costs.
My name is Apurva Saoji. I am a Ph.D scholar in Computer engineering in India. I am looking for international expert in reviewing my PhD thesis, "Competitive Optimization Techniques to Minimize Energy Consumption in Wireless Sensor Network," Kindly do the needful.
I have a function of the form a+(b*r^u) + c*u where a, b, r and c are dependent variables and u is the independent variable.
I am trying to optimize on a, b, r and c by setting a least-squares objective function in COMSOL Multiphysics using the Nelder Mead solver.
I have specified appropriate bounds for the variables, tightening them after each trial when the solver fails to converge, with no solution in sight.
Any recommendations on why it would not converge?
I would like to optimize my extraction using responce surface methodology but I‘m perplexed in choosing what design should I use? I just have 2 factors with 2 levels each, so I considered using CCD but I don’t understand the basic of the run test results which have some replication or about the lack of fits (is this crucial?). If I change it to no replication or minimizing lack of fits, is it ok? Or should I consider another design?
thank you very much for your kind response
Am interested on how we can improve the manufacturing, procurement, distribution and use of pharmaceuticals both medicines and medical supplies in Sub-Sahara Africa
How can the various stages of supply chain management be addressed to increase accessibility, availability and affordability of medicines and medical supplies by the populations of Sub-Sahara Africa
What are the available literature reviews in respect to risk management and reselience; agility and reselience; digitalization; transportation; climate changes in respect to environmental; social and governance; consortium buying; offshoring; in-shoring; local manufacturing versus international manufacturing; local sourcing versus international sourcing; opportunities available at all stages of the supply chain management; innovations necessary to scale increased access; strategic decisions necessary to be taken and other topics related with supply chain management of medicines and medical supplies
2024 5th International Conference on Artificial Intelligence and Electromechanical Automation (AIEA 2024) will be held in Shenzhen, China, from June 14 to 16, 2024.
---Call For Papers---
The topics of interest for submission include, but are not limited to:
(1) Artificial Intelligence
- Intelligent Control
- Machine learning
- Modeling and identification
......
(2) Sensor
- Sensor/Actuator Systems
- Wireless Sensors and Sensor Networks
- Intelligent Sensor and Soft Sensor
......
(3) Control Theory And Application
- Control System Modeling
- Intelligent Optimization Algorithm and Application
- Man-Machine Interactions
......
(4) Material science and Technology in Manufacturing
- Artificial Material
- Forming and Joining
- Novel Material Fabrication
......
(5) Mechanic Manufacturing System and Automation
- Manufacturing Process Simulation
- CIMS and Manufacturing System
- Mechanical and Liquid Flow Dynamic
......
All accepted papers will be published in the Conference Proceedings, which will be submitted for indexing by EI Compendex, Scopus.
Important Dates:
Full Paper Submission Date: April 1, 2024
Registration Deadline: May 31, 2024
Final Paper Submission Date: May 14, 2024
Conference Dates: June 14-16, 2024
For More Details please visit:
Invitation code: AISCONF
*Using the invitation code on submission system/registration can get priority review and feedback

I have an equation in the topic cell less in 5G . The equation is about the system capacity can be calculated as the aggregation of
all active RUs throughput. Then we propose the following as
Optimization problem:
argmax (∑ ∑ ∑ bk,n Rm,k,n) Xb ,Xy m∈M k∈K n∈N
Subject to:
C1 : yk,m ∈ {0, 1}, ∀k ∈ K, m ∈ M (4)
C2 : bk,n ∈ {0, 1}, ∀k ∈ K, n ∈ N (5)
C3 : RD
m,k ≥ RD,min
m,k , ∀k ∈ K, m ∈ M.
The constraints C1, C2, and C3 indicate the user k will associate with a particular RU m, allocate with RB n, and guarantee
minimum rate requirements of the users, respectively. I have a difficult equation that cannot be implemented in MATLAB. I need an equation similar to it, but it should be simple. Can anyone help me ?

Optimization by genetic algorithm (GAO) in electricity and smart grid?
why we use it ?
what is the process of this algorithms ?
What are the possible ways of rectifying a lack of fit test showing up as significant. Context: Optimization of lignocellulosic biomass acid hydrolysis (dilute acid) mediated by nanoparticles
I am working on a project that implements PSO to solve a nonlinear optimization equation (minimization problem). I want to ensure that PSO is not falling for premature convergence (i.e choosing a solution too early and claiming it to be the best solution).
the ERROR was reported as:
SimTK Exception thrown at InteriorPointOptimizer.cpp:264:
Optimizer failed: Ipopt: Infeasible problem detected (status 2)
OPTIMIZATION FAILED...
CMC::computeControls: Optimizer could not find a solution.
Unable to find a feasible solution at time = 0.49( both feet stroked).
Model cannot generate the forces necessary to achieve the target acceleration.
Possible issues: 1. not all model degrees-of-freedom are actuated,
2. there are tracking tasks for locked coordinates, and/or
3. there are unnecessary control constraints on reserve/residual actuators.
to solve this problem ,i had double checked Possible issues 1-3 above, however it did't work.
thanks for your advices,and if you get interested in this problem, please do not hesitate to leave your massages.
I am using a genetic algorithm to solve a multivariable optimization problem. The difficulty in exploring all the solutions is that the permissible set of each variable of the solution is of the form {0} U [a,b], where 0 < a < b (the magnitudes are around a=4 and b=15). "Solutions" that do not satisfy the constraints get a low fitness. So when the genetic explores the search space, it is difficult that it tries solutions with one variable at 0 (zero). I can try to enlarge the interval around 0 and to modify the fitness of variables close to zero. Does anybody know how to treat this kind of constraints? By the way I am using the DEAP genetic algorithms, more precisely this one: http://deap.gel.ulaval.ca/doc/default/examples/ga_onemax.html.
What is the difference between optimization and standardization in research? What difference does validation have from others?
I am currently using pET26b(+) plasmid however, the gene is problematic. and reduce the growth of BL21DE3 cell upon iptg induction. how much yeast is efficent for pYES expression vector.
Dear Mathematicians, Control Engineers, and Optimization Enthusiastics, Could you please compute the domain through which this inequality holds (3/(x-2))<-1? If yes, please prove your answer.
(Note that: the solution is not x> -1, and please don’t use any symbolic math software)
Can any one let me know Classifications of Optimization Techniques are useful for Current research trends? How to choose our suitable Optimization Technique for our research problem.
my article is Optimally Enhancement Rural Development Support Using Hybrid Multy Object Optimization (MOO) and Clustering Methodologies: A Case South Sulawesi - Indonesia
I am trying to optimize my antibodies for free floating IHC-IF on paraformaldehyde fixed mouse brain sections. I want to preserve my slices in an appropriate cryopreservation solution for later use and save their freshness. I can not order ethylene glycol due to some legal issues. They suggested diethylene glycol instead of ethylene glycol but I couldn't find any recipe or paper about its use on slice preservation. Is ıt possible to use diethylene glycol instead of ethylene glycol for slice cryopreservation? And lastly, can I use it with PVP40?
My protocol for cropreservation is:
Sucrose ----------------------------- 300 g
Polyvinyl-pyrrolidone (PVP-40) --- 10 g
0.1M PB ----------------------------- 500 ml
Ethylene glycol --------------------- 300 ml
Thank you in advance.
Can anyone suggest me some new optimization techniques and thair matlab codes.
Hello experts
I am dealing with an optimization problem in which the algorithm will choose the section of the column (RC structure) between a lower and an upper bound (e.g., LB and UB).
How can I ask the algorithm to change the cross section if the condition of the period isn't satisfied?
N.B: the period value is retrieved from the sap2000 software using the API, and it has no relation with the design variables to be set as a constriant.
Any one knows how to do it please?
The set of optimal solutions obtained in the form of Pareto front includes all equally good trade-off solutions. But I was wondering, whether these solutions are global optima or local optima or mix of both. In other words, does an evolutionary algorithm like NSGA-II guaranties global optimum solutions?
Thank you in anticipation.
What are the best practices for optimizing performance and efficiency in R programming, particularly when dealing with large datasets or computationally intensive tasks? Are there any specific techniques or packages that researchers should be aware of?
Hi everyone,
I want to use the Casadi optimization package for my NLMPC controller in Matlab/Simulink.
I read the examples of https://web.casadi.org/ site, but I can't modify them for my problem.
I want to use Casadi for the tacking problem, so I will have a time-varying cost function and I have time-varying constraints as well.
All the examples which I saw aren't included the time-varying cost function or time-varying constraints.
I would be grateful if anyone can help me.
Regards,
Hossein.
Suppose we have a HEN with several multi-pass heat exchangers. However, due to some technical constraints all these exchangers are modelled simply using single pass equations.
What will the impact if such a simplistic model is used in optimization problems, such as network optimization for retrofitting or cleaning scheduling?
For instance, it is clear that we may not end up with global optimal solutions but still what will the qualitative impact of such approximations?
I am using Gaussian to estimate the ionization potential of a cluster of molecules including 6 molecules of Methanol and 1 molecule of Fluorobenzene, I have optimized the geometry of the neutral cluster and then did a single point energy calculation of the optimized geometry with +1 charge, the difference between energy of the two gives me a rough estimate of the IP, my question is how can we interpret this IP, is it the IP of the whole system or the molecule from which the electron has been removed? also by visualizing the HOMO orbitals in both cases I noticed that the HOMO in neutral case is one of the Pi orbitals of the Fluorobenzene ring while in the ionized case it's the bonding orbital of one of the methanol molecules, not sure how to interpret that?
Hi everyone,
I'm performing DFT Calculation / Geometry Optimization of some 5,7-dibromobenzofurane hydrazide derivatives using ORCA 4.2.1 and BY3LP basis set (! B3LYP RIJK def2-TZVP def2/JK).
Each of 5,7-dibromobenzofurane derivatives has two isomers: anti-isomer and syn-isomer.
While the anti-isomer of a compound was successfully calculated with SCF converged after 43 cycles, the syn- one was not able to obtain the final results with this error:
----------------------------------------------------------------------------------
FINAL SINGLE POINT ENERGY -6213.007766579487 (Wavefunction not fully converged!)
----------------------------------------------------------------------------------
ERROR
This wavefunction IS NOT FULLY CONVERGED!
You can't use it for properties or numerical calculations !
Aborting the run ...
Please restart calculation (with larger maxiter/different convergence flags)
----------------------------------------------------------------------------------
Herein I attached two ouput files corresponding two isomers of a compound.
I am having issues resolving PCR inhibition in rhino dung samples for a metagenome sequencing project. I used the DNeasy Blood and Tissue Kit to extract gDNA (with expected low yields, but DNA present all the same), and have attempted to clean extracts amplify the 18S region using NEB's Q5 HiFi 2x Mastermix. I know that the primers themselves are robust, the positive control looks great, and all fecal samples EXCEPT for rhino amplify well! Cleanups/Optimizations that I have tried: 1) Monarch Kit (best Nanodrop 260/230, 260/280 values), 2) Double extractions using Qiagen's DNeasy columns, 3) Dilutions (1:5, 1:10, 1:20, 1:50, 1:75), 4) Optimizing PCR by adding 5% DMSO and 5M Betaine, 5) Zymo's 1-Step PCR Inhibitor Cleanup Kit.
Help!
Could anyone please mention the inputs i require from an offgrid wind farm for the optimization of LCOH.
I am really new into this topic and currently doing research on the modelling aspect.
I have optimized several of my diastereomers on spartan (M06-2X, 311+G**, CPCM ACETONITRILE) I managed to have all positive frequencies. However I'm getting the syn isomer as the more favorable, however, my experimental data clearly indicates that the anti is the more favorable product. Can anyone suggest to me what to do? I have tried other methods and the results are the same.
Optimization is a statistical technique and done by using linear programming. it is being used in farming systems.
Although I have tried certain methods to remove the error.But it still persists.
I have cleaned the disk, restart the system and use the system best suited to satisfy the computational requirements.
In addition, I also try installing it again in the system.
But still error persist.
This was suggexted by someone.
Hello experts
This question is shared with one of my research team.
We are dealing with an optimization problem in which the algorithm will choose the cross-section of the column (RC structure) between a lower and an upper bound (e.g., LB and UB).
We know that the obtained optimal values for the section can be for example 330mm.
Recently, we came across this phrase in a paper dealing with the same problem where the author stated that 'The column sections are square with dimensions of 250 mm × 250 mm to 1200 mm × 1200 mm, by a step of 50 mm'
Our concern is how to oblige the algorithm to choose 50mm for the next candidate within the design interval.
Anyone knows how to do it, please?
Where is the Jade due to the throwing out of a brick and a paving stone?
A brand new conception of preferable probability and its evaluation were created, the book was entitled "Probability - based multi - objective optimization for material selection", and published by Springer, which opens a new way for multi-objective orthogonal experimental design, uniform experimental design, respose surface design, and robust design, discretization treatment and sequential optimization, etc.
It aims to provide a rational approch without personal or other subjective coefficients, which is available at https://link.springer.com/book/9789811933509,
DOI: 10.1007/978-981-19-3351-6.
Best regards.
Yours
M. Zheng
What challenges and use cases are associated with designing an optimization xApp for O-RAN?
In O-RAN (Open RAN), xApp communicates with RIC (Radio Intelligence Controller) to impose policies on the radio access network (RAN). The RIC is responsible for managing and coordinating the DUs (Distributed Units) and RUs (Radio Units) in the RAN. The workflow for this process is as follows:
- xApp generates and sends a policy to the RIC.
- The RIC receives the policy and translates it into a series of commands.
- The RIC sends the commands to the relevant DUs and RUs.
- The DUs and RUs execute the commands and update their configurations accordingly.
- The RIC monitors the status of the DUs and RUs and reports back to the xApp.
- The xApp has access to the status of the DUs and RUs and can make updates to the policies based on the received status.
In this way, xApp has access to both DU and RU activities through the RIC. The RIC acts as an intermediary between xApp and the DUs and RUs, ensuring that policies are applied consistently and effectively across the RAN.
The Question is How can we read and check the xApp activities? its inside the RIC or logged in CU DU?
Can anybody help me if in finding any existing literature where I can find the energy of Polyethylene optimized structure 12 monomer units using DFT level of theory
HCP has two parameters to optimize namely a and c/a; the process detailed here gives pretty accurate result to determine those parameters. Zr is taken as an example here, where positions are special, high symmetry positions, i.e. (1/3, 2/3,1/4) and (2/3, 1/3,3/4)
i. Take 7 to 8 different volumes across the estimated equilibrium volume (from published XRD data).
ii. Range of volume scanned should be typically within +/- 10%
iii. If atom positions are in high symmetry positions then atoms should not be moved. However, in the POSCAR file set 'selected dynamics' and motion should be set to T, to get force info in OUTCAR, but set ISIF=5 in INCAR to change only the shape of the unit cell.
An example of POSCAR -
HCP Zr parama (vary this to get different volume) 1.000000000 0.000000000 0.00000000000 -0.500000000 0.866025404 0.00000000000 0.000000000 0.000000000 1.60000000000 Zr 2 Selective dynamics Direct 0.6666666666666667 0.3333333333333333 0.7500000000000000 T T T 0.3333333333333333 0.6666666666666667 0.2500000000000000 T T T
iv. INCAR setting
ISTART=0 LREAL=.FALSE. PREC=Accurate ADDGRID=.TRUE. ENCUT=550 ISPIN=2 NPAR=6 MAGMOM=2*2.0
IBRION=2 ISIF=4 POTIM=0.15 ISMEAR=1 SIGMA=0.01
NSW=100 NELM=50 EDIFF=1.0E-6
v. Fit 3rd order BM EOS to determine the equilibrium energy, volume and bulk modulus (E0, V0 and B)
vi. For each run also find the final a and c/a
vii. Fit 3rd order BM EOS between E vs. a^3 to determine the equilibrium a0^3, during this fitting keep E0 constant (found from step v)
viii. Now we have both V0 and a0, from which c0/a0 can be calculated. Use these final cell parameters to determine the energy accurately using ISMEAR = -5 in INCAR.
In consideration of lipemic samples being one of the most commonly encountered interferences in routine clinical chemistry assays (Ho et al., 2021, p. 1), are there any removal methods that are immediately available for samples affected with lipemia?
According to Nikolac (2014), the CLSI recommended method is ultracentrifugation among other methods, however, this method may be quite costly. So, I’m wondering if there are methods which would be more accessible for small, remote laboratories.
Reference Articles:
- Ho, C. K., Chen, C., Setoh, J. W., Yap, W. W., & Hawkins, R. C. (2021). Optimization of hemolysis, icterus and lipemia interference thresholds for 35 clinical chemistry assays. Practical Laboratory Medicine, 25, e00232. https://doi.org/10.1016/j.plabm.2021.e00232
- Nikolac N. (2014). Lipemia: causes, interference mechanisms, detection and management. Biochemia medica, 24(1), 57–67. https://doi.org/10.11613/BM.2014.008
Interpretable, credible and responsible multimodal artificial intelligence preface--DIKWP model (beyond ChatGPT)
Already 312 times read 2023-2-11 15:23 |System Classification: Paper Exchange
First answer what is artificial intelligence (Artificial Intelligence, AI)?
Subjects and objects in the entire digital world and cognitive world can be consistently mapped to the five components of the DIKWP model and their transformations: Data Graph, Information Graph, Knowledge Graph, Wisdom Map (Wisdom Graph), intention map (Purpose Graph).
Each DIKWP component corresponds to the semantic level of cognition, the concept and concept instance level of human language: {semantic level, {concept, instance}}
Model <DIKWP Graphs>
::=(DIKWP Graphs)*(Semantics, {Concept, Instance})
::={ DIKWP Graphs*Semantics, DIKWP Graphs*Concept, DIKWP Graphs*Instance }
::={ DIKWP Semanics Graphs, DIKWP Concept Graphs, DIKWP Instance Graphs }
Interactive scene <DIKWP Graphs>
::={DIKWP Content Graph includes: Data Content Graph, Information Content Graph, Knowledge Content Graph, Wisdom Content Graph, Purpose Content Graph;
DIKWP cognitive model (DIKWP Cognition Graph) includes: Data Cognition Graph, Information Cognition Graph, Knowledge Cognition Graph, Wisdom Cognition Graph , Purpose Cognition Graph.
}
Artificial intelligence is the capability part of DIKWP interaction.
AI::=(DIKWP Graphs)*(DIKWP Graphs)*
Narrow definition: Artificial intelligence is the development-oriented elimination of duplication in the DIKWP interaction, the integrated storage-computing-transmission iterative capability and the cross-DIKWP-oriented (Open World Assumption) OWA scope conversion capability.
We are conducting ChatGPT's artificial intelligence ability test and look forward to sharing it with you.
Examples of our related work:
Typed Resource-Oriented Typed Resource-Based Resource Management System (Authorized)
Value Driven Storage and Computing Collaborative Optimization System for Typed Resources
Application publication number: CN107734000A
For a list of all relevant invention patents, see:
List of Chinese national invention patents authorized by the DIKWP team for the first inventor Duan Yucong during the three years from 2019 to 2022 (69/241 in total)
Please visit: https://blog.sciencenet.cn/blog-3429562-1354842.html
Hello dear researchers.
Please, how do I know that I have done a good optimization of the structure (I use abinit), should I see something in the output file or just compare the cell parameters with the experimental values?
Thank you in advance.
Sincerely.
Hello! I am going to conduct a study on the application of Vehicle Routing Problem in real world. However, I am struggling with how I construct my networks. I would like to ask on how to define the edges/arcs/links between the vertices.
For example, what should the edge between cityA and cityB represent? Most literatures use travel times which is based on road distances from cityA to cityB. However, there are a lot of paths from cityA to cityB. The way to address this is to use the shortest path from cityA to city B. Are there any alternatives to address this issue? What should the edge between two vertices represent?
This new way of accessing information through a reward model for reinforcement learning requires collecting comparison data, which consists of two or more model responses classified by quality. Data collection is performed through conversations that the AI trainers had with the chatbot, enhanced by Reinforcement Learning with Human Feedback. A written message is randomly selected per model, trying out several alternative conclusions and asking the AI trainers to rate them.
The use of reward models can adjust the model using Proximal Policy Optimization. Models such as GPT-3 and Codex are also implemented.
How can I calculate ANOVA table for the quadratic model by Python?
I want to calculathe a table like the one I uploaded in the image.

For difficult to transduce adherent cell lines, I was wondering if anybody has tried spinoculation with polybrene? If so, what is the protocol you used?
Please advise a reference to paper/book/sources with description of Complex value test functions for optimization like extended Rosenbrock or Powell? There are many analytical functions for testing non-linear/optimization algorithms but I was able to find only cases for real numbers. So the question is how to test a case when Jacobian/residual are complex value matrix/vector?
linear least squares problem::
fit f(t) = sin(t) on the interval [0, π] with polynomials of degree n with n = 1, 2, 3, · · · , 10. Here, we use equally spaced nodes.
Solve the normal equation with a backslash in Matlab. Save the norm of the residual and the condition numbers of AT A??
Could anybody please tell me how can find x, y, and A in that case ??
Hello, I've been tasked with validating a 2kb region of DNA. A colleague designed primers with the F melting at 53.8 and the reverse at 59.7. I believe they used 54C which had multiple bands show up in their gel due to specificity issues. I am trying to optimize the reaction but don't know what temp would give the best results. Redesigning was my first thought but that's not an option. My plan now is to start at 56, see what I get if its still not specific enough than increase until I get clear bands. The problem however is this will be quite time consuming and will waste resources. Any input on next steps would be greatly appreciated.
Thank you
I am working on topology optimization for photonic devices. I need to apply a custom spatial filter on the designed geometry to make it fabricable with the CMOS process. I know there exist spatial filters to remove the pixel-by-pixel and small features from the geometry. However, I have not seen any custom analytical or numerical filters in the literature. Can anyone suggest a reference to help me through this?
Thanks,
Hello Researchers,
I am Marwen Amiri, A PhD student, my subject is "Optimization of RFID systems used in wireless body networks" it is a purely "internet of things" subject, I wanted to know if it would be possible to simulate WBAN networks with the physiological parameters of a human body using NetSim or Omnet ++ or another simulator ? i want to modify the TxPower and the distance between sensors to evaluate the performance of a WBAN network in terms of PLR, latency and energy consumption. The main objective is to determine some objectives of optimization by simulation and testing of some algorithms of multiobjective optimization (Node coverage, interference, control of Txpower, number of sinks, number of nodes, etc...)
if it's possible, I wanted to know also, how can I find the library of a Phantom of a human body with its physiological parameters to use it in one of the iot simulators. In fact, I found several simulations of BAN networks on Youtube, but without source code, since we want to work on a human body with physiological parameters to perform our simulations with normal or RFID sensor nodes.
Can you help me with information, papers or contacts ? I did not find many resources in this area of research
Cordially
There are various steps involved in western blot analysis. Any tips or optimization tricks you might have used that worked and made work easy for you. Please kindly, drop in in the discussion. For new and Old Grad students that are working with old equipments and not able to afford already- made reagents. Thanks
In his name is the judge
Hi
There is a fuzzy logic control system in python. The system contain 2 inouts and 18 outputs.
inference of system is mamdani and shape function used to be guassian.
Then in term of refine performance of the controller I need to optimize specifications belong to shape functions of both input and output. In order to that I need to use multi objective optimization.
We have 2 input and 1 output in case of this problem. I have developed 3 shape functions for each entrance and 3 for output and the shape function is gaussian so we have 18 parameters totally.
I defined my problem as a function in python. But notice this I there is not any clear relationship between input and output of function. It’s just a function which is so complicated with 2 inputs and 18 outputs.
I made my decision to use NSGAII algorithm and I really don't want to change the algorithm.
So I try every way to optimize my function but I didn’t find any success. By searching about python library which can do multiobjective optimization I find Pymoo as the best solution but I really failed to optimize my function which is complicated custom function, with it.
So It’s really my pleasure if you can introduce me a library in python or suggest me a way that I can use Pymoo in order to this aim.
wish you best
Take refuge in the right.
I am trying to optimize zeolite bulk structure with some of the silicon atoms being replaced by Al in VASP. But it's not converging and the job stops after 1 iteration. There is no error message also. I am using vdw-RE tag. What should I do to converge it successfully?
I have L16 for Machining and some researchers do RSM after GRA using GRG data.
How we can do that?
Thanks
When I try to perform the following calculation, Python gives the wrong answer.
2*(1.1-0.2)/(2-0.2)-1
I have attached a photo of the answer.

I am working on a non-linear optimization problem. Even though I wrote the code correctly and it doesn't give an error message, the optimal values are zero. please if there is someone who masters in lingo model help me .
Thank you
I'm searching for new collaborations. I'm focused mostly on numerics on obtaining solitons bifurcating from band edges and localized modes. I'm specialized in shooting methods with more than one parameter, NR optimized for CUDA obtaining solutions, parametric curve step to obtain branches that cannot be described by a function. Optimization of split-step FFT dynamics with coupled Nonlinear partial differential equations, Ex: SHG was the harder one. I worked previously with V. Konotop, F. Abdullaev and B. Malomed. I was first author on all papers. They provided the equations and researched on obtaining solutions.
Although the genetic algorithm is very helpful to find a good solution, it is very time-consuming. I've recently read an article in which the authors used the genetic algorithm for pruning a neural network on a very small dataset. They pruned a third of their network and reduces the size of the model from 90MG to 60MG. Their pruning also decreased the inference time of their model by around 0.5 seconds. Although, unlike other methods, pruning using the genetic algorithm does not deteriorate their model's performance, finding redundant parts of the network using the genetic algorithm is an overhead. I wonder why they think their method is useful and why people still use the genetic algorithm.
I am trying to Optimize TiO2 bulk (Anatase), I need an examined INCAR file.
I have trained a regression svm model for a set of experimental data which has 4 parameters - initial concentration, pH, T and dosage. The response is equilibrium loading. Now, I want to use the trained model to get optimal conditions for the same, i.e., to find the experimental parameters at which we get maximum equilibrium loading. Since, a svm model doesn't give the parameters of the model it would be difficult to find the parameters. Kindly suggest some ways to do this.
Dear friends,
Would you please tell me where I can find a dynamic list (updated constantly) of new meta-heuristic algorithms?
Thanks in advance for your guidance,
Reza
I am looking for examples of using home energy storage to reduce energy peaks on a daily basis in the case of PV. There is a need to use many home energy storage (several hundred thousand in Poland) to cut PV energy peaks.
In robust optimization, random variables are modeled as uncertain parameters belonging to a convex uncertainty set and the decision-maker protects the system against the worst case within that set.
In the context of nonlinear multi-stage max-min robust optimization problems:
What are the best robustness models such as Strict robustness, Cardinality constrained robustness, Adjustable robustness, Light robustness, Regret robustness, and Recoverable robustness?
How to solve max-min robust optimization problems without linearization/approximations efficiently? Algorithms?
How to approach nested robust optimization problems?
For example, the problem can be security-constrained AC optimal power flow.
In his name is the judge
Hi
I want to learn multi-objective optimization with NSGAII in python for my research.
Please recommend a good source for learning NSGAII in python.
wish you best
Take refuge in the right.
How does one optimize a set of data which is comprised of 3 input variables and 1 output variable (numerical variables) using a Genetic Algorithm? and also how can I create a fitness function? How is a population selected in this form of data? What will the GA result look like, will it be in a form of 3 inputs and 1 output?
I do understand how the GA works, however, I am confused about how to execute it with the form of data that I have.
My data is structured as follows, just for better understanding:
3 columns of Input data, and the fourth column of Output Data. (4 Columns and 31 rows) data. The 3 input variables are used to predict the fourth variable. I want to use GA to improve the prediction results.
Lastly, Can I use decimal numbers (E.g. 0.23 or 24.45); or I should always use whole numbers for chromosomes.
I have running GA optimization using "gamultiobj" in Matlab. The upper bound and lower bound of my design variables are like [10 30 175 1] and [30 60 225 3]. But after convergence, I see the design variables (like all of them) near 20,47,175 and 1. I am not getting a Pareto Front. What could be the possible reasons for that?
Hello everyone, I am looking for a good MPC quadratic optimization mathematical model to optimize a cost function or performance index, for a battery energy storage state space model. Would anybody suggest a good research paper or post a formulation that contains a good mathematical model for quadratic optimization? An objective function with viable constraints, which can be possible to implement in function solvers such as quadprog or cplex would be ideal. Thank you
In your opinion, what are the main aspects of Econo-Mathematical Optimization ?
I've been using GMAT in my free time to optimize trajectories, and have varied burn component values and spacecraft states, usually with success. The vary command in GMAT, with the Yukon optimizer that I am using, has the following parameters that can be changed:
- Initial value: The initial guess. I know the gradient descent optimization method that GMAT uses is very sensitive to initial conditions and so this must be feasible or reasonably close.
- Perturbation: The step size used to calculate the finite difference derivative.
- Max step: The maximum allowed change in the control variable during a single iteration of the solver.
- Additive scale factor: Number used to nondimensionalize the independent variable. This is done with the equation xn = m (xd + a), where xn is the non-dimensional parameter, xd is the dimensional parameter and this parameter is a.
- Multiplicative scale factor: Same as above, but it's the variable d in the equation.
For the initial value, I can usually see when my chosen value is feasible by observing the solver window or a graphical display of the orbit in different iterations. The max step is the most intuitive of these parameters for me, and by trial and error, observation of the solver window and how sensitive my target variables are to changes in the control variables I can usually get it right and get convergence. It is still partially trial and error though.
However, I do not understand the effect of the other parameters on the optimization. I read a bit about finite difference and nondimensionalization/rescaling, and I think I understand them conceptually, but I still don't understand what values they have to be to get an optimal optimization process.
This is especially a problem now because I have started to vary epochs (TAIModJulian usually) or time intervals (e.g. "travel for x days" and find optimal x, or to find optimal launch windows), and I cannot get the optimizer to vary them properly, even when I use a large step size. The optimizer usually stays close to the initial values, and eventually leads to a non-convergence message.
I have noticed that using large values for the two scale factors sometimes gives me larger step sizes and occasionally what I want, but it's still trial and error. As far as perturbation goes, I do not understand its influence on how the optimization works. Sometimes for extremely small values I get array dimension errors, sometimes for very large values I get similar results to if I'm using too large a max step size, and that's about it. I usually use 1e-5 to 1e-7 and it seems to work most of the time. Unfortunately information on the topic seems sparse, and from what I can tell GMAT's documentation uses different terminology for these concepts than what I can find online.
So I guess my question is two-fold: how to understand the optimization parameters of GMAT and what they should be in different situations, and what should they be when I want GMAT to consider a wide array of possible trajectories with different values of control variables, especially when those control variables are epochs or time intervals? Is there a procedure or automatic method that takes into account the scale of the optimization problem and its sensitivity, and gives an estimate of what the optimization parameters should be?
I have designed the optimization experiment using Box-Behnken approach.
What should I do if any of the factors combination fails, for example because the aggregation occurs.
Should I review whole optimization or is there any method to skip the particular factors combination?
And if I need to review the whole experiment, what method should I use to evaluate boundary factors values? Screening methods I have seen require at least 6 factors to be screened.
Any help is appreciated.
Greetings.
I have generated 16 variable probability distributions in the form of a 16 dimensional NumPy array in python. How could I determine all the peaks in this function in python or using some software?










































































































































