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Evolutionary Design of Neural Networks
Kastner, Jan ; Hurta, Martin (referee) ; Sekanina, Lukáš (advisor)
The thesis deals with the implementation of a problem-solving method for the automated design of convolutional neural networks (CNN) architectures. The optimization of two fundamental and often conflicting characteristics, the number of parameters and the quality of CNN classification, is performed using a multi-criteria optimization genetic algorithm (NSGA-II). To encode this problem, the Cartesian genetic programming (CGP) technique is used, which enables the wide range of CNN architectures to be represented, and at the same time, the searched area can be appropriately limited by parameterization. Experiments were performed on the MNIST dataset to understand the effect of population size on the quality of the resulting solution. It is also evident from the results of the experiments that the quality of the architectures found can compete with already established models. This is therefore an alternative approach that does not require human intervention compared to manual design.
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Machine Learning of Representations in Genetic Programming
Pomykal, Šimon ; Piňos, Michal (referee) ; Sekanina, Lukáš (advisor)
The aim of this thesis is to become acquainted with machine learning methods that are used for the automatic design of representations. Specifically, the work focuses on deep learning in the field of genetic programming (GP). Image processing is chosen as a case study, particularly noise reduction methods. By combining the acquired knowledge, a new representation is proposed, intended to replace the syntactic tree in the GP algorithm. This method is obtained using a transformer-type neural network. In conclusion, a modified version of GP that works with the new representation is created. This variant is compared with the original GP using the traditional representation in several experiments.
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Implementation and Comparison of Nature-Inspired Search Algorithms
Malysák, Adam ; Husa, Jakub (referee) ; Sekanina, Lukáš (advisor)
This thesis deals with the description, implementation and comparison of genetic algorithm, genetic algorithm enhanced with local search heuristic and binary particle swarm optimization (BPSO). These are algorithms inspired by natural phenomena, specifically the evolution and movement of bird flocks or fish schools. Implemented algorithms are used to solve the 3-SAT problem, which is also described in this thesis. Algorithms are tested on 3-SAT benchmarks and compared to each other and to other papers.
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Aproximace obvodů s využitím alternativních reprezentací
Michalisko, Tomáš ; Mrázek, Vojtěch (referee) ; Sekanina, Lukáš (advisor)
This master's thesis deals with the design of approximate circuits using alternative representations. The investigated representations include the And-inverter graph, Majority-Inverter graph, and Xor-Majority graph. Cartesian genetic programming is employed for design automation. By computing the approximation error using formal methods, the developed system can be applied to more complex circuits. In the first part of the experiments, the speed of the program is evaluated and optimized. Subsequently, a suitable mutation operator is searched for. Then, the system is tested for approximating 8-bit multipliers and 16-bit adders with the aim of minimizing size and delay. The results show that adders and multipliers in the XMG representation achieve better fitness values compared to evolution at the gate level. Finally, an evolution targeting the k-LUT technology is performed. Here, gates remain the most efficient representation.
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Statistical Model Checking of Approximate Computing Systems
Blažek, Michal ; Sekanina, Lukáš (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis focuses on the simulation of models of approximate multipliers. The main aim of the thesis is comparing selected properties of multipliers in an application-specific scope of input values. The thesis includes the conversion of multiplier models from the EvoApproxLib library into models used in the UPPAAL environment. These models are then simulated while monitoring their selected evaluation metrics such as error probability, mean absolute error, etc. From the obtained results, one can conclude that using a suitable approximate multiplier in a specific context can have a positive effect on the error in calculations. The results could therefore have further applications in the field of approximate computing systems.
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Evolutionary Design of Non-Linear Functions for Convolutional Neural Networks
Hladiš, Martin ; Mrázek, Vojtěch (referee) ; Sekanina, Lukáš (advisor)
The aim of this thesis is to design and implement a program for automated design of nonlinear activation functions for convolutional neural networks (CNN) using evolutionary algorithms. The use of automated design provides an independent view to systematically explore a wide range of activation functions and identify the best ones. The method for automatic design chosen in this thesis is a form of evolutionary algorithms referred to as Cartesian genetic programming, which uses a graph representation to encode the solution. This technique allows for the definition of a set of mathematical primitives that define the search space, and thus simply parameterize the design. The implemented approach has been tested on several different architectures and datasets (LeNet-5 \& MNIST, ResNet-10 \& FashionMNIST, WRN-40-4 \& CIFAR-10). Experiments have shown that the approach can find activation functions that statistically improve the accuracy of the architecture over the commonly used ReLU function.
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Automated compression of neural network weights
Lorinc, Marián ; Sekanina, Lukáš (referee) ; Mrázek, Vojtěch (advisor)
Konvolučné neurónové siete (CNN) od svojho vynájdenia zrevolucionizovali spôsob, akým sa realizujú úlohy z odvetvia počítačového videnia. Vynález CNN viedol k zníženiu pamäťovej náročnosti, keďže váhy boli nahradené konvolučnými filtrami obsahujúcimi menej trénovateľných váh. Avšak, toto zníženie bolo dosiahnuté na úkor zvýšenia požiadaviek na výpočtový výkon, ktorý je naviazaný na výpočet konvolúcie. Táto práca skúma hypotézu, či je možné sa vyhnúť načítavaniu váh a miesto toho ich vypočítať, čím sa ušetrí energia. Na otestovanie tejto hypotézy bol vyvinutý nový algoritmus kompresie váh využívajúci Kartézske genetické programovanie. Tento algoritmus hľadá najoptimálnejšiu funkciu kompresie váh s cieľom zvýšiť energetickú účinnosť. Experimenty vykonané na architektúrach LeNet-5 a MobileNetV2 ukázali, že algoritmus dokáže efektívne znížiť spotrebu energie pri zachovaní vysokej presnosti modelu. Výsledky ukázali, že určité vrstvy je možné doplniť vypočítanými váhami, čo potvrdzuje potenciál pre energeticky efektívne neurónové siete.
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Automated Representation Learning for Cartesian Genetic Programming Using Neural Networks
Koči, Martin ; Mrázek, Vojtěch (referee) ; Sekanina, Lukáš (advisor)
This master's thesis addresses the integration of neural networks and Cartesian Genetic Programming (CGP). It explores the use of neural networks for automated representation creation for CGP and their application to improve the evolutionary process in CGP. The study covers basic concepts of machine learning, including various types of learning and neural network models. It also touches on evolutionary algorithms with an emphasis on their basic principles, general algorithms, and types of representations. This work also includes principles of representation learning and two fundamental architectures for their creation. It describes the subsequent use of representation learning in genetic programming. The solution design includes data acquisition and preprocessing, representation creation processes, and the utilization of the resulting representations. The thesis also implements two new approaches for creating representations for Cartesian genetic programs. It further explores their use in two new mutation operators, where one is based on direct modification of the vector representation and the other on the selection of genes for mutation based on their similarity. The last of the explored areas is predicting the suitability of candidate solutions using newly emerged representations.
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Využití operátoru křížení v kartézském genetickém programování
Bromnik, Petr ; Sekanina, Lukáš (referee) ; Hurta, Martin (advisor)
The aim of this paper is to propose and implement two new crossover methods in Cartesian Genetic Programming (CGP) and compare them with existing approaches. CGP is a type of evolutionary algorithm that uses acyclic graphs to represent executable programs. Most CGP applications use the mutation operator only, but the effort to find a suitable crossover operator is still ongoing. In this paper, the two newly proposed crossover methods are compared on five symbolic regression problems against the standard 1 + lambda procedure based purely on mutation. Experimental results show that these methods find solutions in a similar number of fitness evaluations as 1 + lambda and, in two cases, even significantly earlier.
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Evolutionary Design of Local Image FIlters
Gall, Samuel ; Hurta, Martin (referee) ; Sekanina, Lukáš (advisor)
This thesis focuses on the research and implementation of evolutionary design of local image filters. The aim is to create a tool capable of automatically designing suitable image operators for image filtering, specifically noise removal, using an evolutionary design method called Cartesian Genetic Programming (CGP). The tool was used for various experiments with different settings of CGP parameters such as grid size, population size, and mutation parameter. The created filters were compared with conventional noise removal filters. Evolved filters were tested on a set of test images, where their behavior was comparable to that of a median filter. Unlike the median filter, evolved filters were able to preserve more image quality.
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