|
|
Sorting Networks Design Using Coevolutionary CGP
Fábry, Marko ; Hrbáček, Radek (referee) ; Drahošová, Michaela (advisor)
This paper deals with sorting networks design using Cartesian Genetic Programming and coevolution. Sorting networks are abstract models capable of sorting lists of numbers. Advantage of sorting networks is that they are easily implemented in hardware, but their design is very complex. One of the unconventional and effective ways to design sorting networks is Cartesian Genetic Programming (CGP). CGP is one of evolutionary algorithms that are inspired by Darwinian theory of evolution. Efficiency of the CGP algorithm can be increased by using coevolution. Coevolution is an approach that works with multiple populations, which are influencing one another and constantly evolving, thus prevent the local optima deadlock. In this work it is shown, that with the use of coevolution, it is possible to achieve nearly twice the acceleration compared to evolutionary design.
|
|
|
Optimization of the Distributed I/O Subsystem of the k-Wave Project
Vysocký, Ondřej ; Hrbáček, Radek (referee) ; Jaroš, Jiří (advisor)
This thesis deals with an effective solution of parallel writing of variable amounts of data on the Lustre file system. The work will be used by the k-Wave project designed for time domain acoustic and ultrasound simulations. Since the simulation is computationally and data intensive, the project requires to be implemented with libraries for parallel computig (Open MPI) and large data processing (HDF5) and it must run on a supercomputer. The application is implemented in C and uses previously mentioned libraries. The proper settings of the Lustre file system leads to the peak write bandwith of 2.5 GB/s that corresponds to a speedup factor of 5 compared to the reference settings. The data aggregation improved the write bandwidth by a factor of 3 compared to a naive version. Here, the achieved I/O bandwidth for certain block sizes hits the limits of the Anselm I/O subsytem (3GB/s).
|
|
|
On-Chip Debugger Generator
Hrbáček, Radek ; Mecera, Martin (referee) ; Hruška, Tomáš (advisor)
This bachelor's thesis deals with the design and implementation of an on-chip debugger and its connection to the hardware generated using software tools developed as a part of the Lissom project. The first part introduces the JTAG and Nexus 5001 standards, which the implemented interface complies with. The practical part includes detailed description of the developed tool and its testing. The result is a functional on-chip debugger that has been tested with the Codea processor on the FITKit educational platform.
|
|
|
Coevolutionary Algorithm in FPGA
Hrbáček, Radek ; Vašíček, Zdeněk (referee) ; Drahošová, Michaela (advisor)
This thesis deals with the design of a hardware acceleration unit for digital image filter design using coevolutionary algorithms. The first part introduces reconfigurable logic device technology that the acceleration unit is based on. The theoretical part also briefly characterizes evolutionary and coevolutionary algorithms, their principles and applications. Traditional image filter designs are compared with the biologically inspired design methods. The hardware unit presented in this thesis exploits dual MicroBlaze system extended by custom peripherals to accelerate cartesian genetic programming. The coevolutionary image filter design is accelerated up to 58 times. The hardware platform functionality in the task of impulse noise filter design and edge detector design has been empirically analyzed.
|
|
|
Compressive sampling and simulation of one-pixel camera
Hrbáček, Radek ; Špiřík, Jan (referee) ; Rajmic, Pavel (advisor)
The Nyquist theorem is the main pillar of the traditional digital signal processing approach. It states that the sampling rate must be at least twice the maximum frequency present in the signal to guarantee perfect signal reconstruction from the sequence of its samples. In practice, we often compress the signal right after the sampling process to reduce the data size. The compressive sampling approach is not limited to the frequency domain, it provides a new look at the signal by using an arbitrary basis. If we find a basis in which the signal is sparse, it is possible to take a small number of samples and reconstruct the signal successfully. One-pixel camera is one of real applications, it's formed by digital micromirror array reflexing the light into single sensor. Mathematical methods are then used to reconstruct the signal. This thesis deals with the simulation of the camera.
|
|
|
Adaptive Plot Generation in Role-Playing Game
Vymazal, Jiří ; Grochol, David (referee) ; Hrbáček, Radek (advisor)
Generating a story, while trying to preserve at least some qualities of author-written narrative is a complex issue. In this thesis several currently existing systems and approaches are discussed. Then, a solution based on evolutionary computation is presented, and its traits shown on small-scale proof-of-concept scenario. Finally, this approach is compared againist existing solutions.
|
|
|
Efficient Implementation of High Performance Algorithms on Intel Xeon Phi
Šimek, Dominik ; Hrbáček, Radek (referee) ; Jaroš, Jiří (advisor)
This thesis is dedicated to the implementation of high performance algorithms on the Intel Xeon Phi coprocessor. The Xeon phi was introduced by Intel as a new MIC (Many Integrated Core) architecture in 2012. The theoretical part of the thesis is focused on the architecture of the coprocessor (with peak performance of 2 tFLOPS for a single precision data) and on the procedure of algorithms implementation and optimization. The theoretical knowledge is then applied to a practical examples with demonstration of the implementation and the optimization of algorithms and work with the coprocessor. In the practical part of the thesis, simple benchmarks such as a vector matrix multiplication and a matrix multiplication are explained and implemented. In the first benchmark 6.5% of theoretical coprocessor performance was achieved, in the second it was much more. In following chapter a more complex benchmark - simulation of a particles system (N-Body), that reached more than 35% of coprocessor performance (725 gFLOPS), is discussed. The following section is dedicated to some interesting problems such as optimization of a MATLAB module k-Wave (propagation of the ultrasound waves), extraction of I-vector (speech processing), cross-compilation of existing libraries, modules and programs. In the conclusion of the thesis the usage the potential of the Intel Xeon Phi is evaluated.
|
|
|
Coevolution of Image Filters and Fitness Predictors
Trefilík, Jakub ; Hrbáček, Radek (referee) ; Drahošová, Michaela (advisor)
This thesis deals with employing coevolutionary principles to the image filter design. Evolutionary algorithms are very advisable method for image filter design. Using coevolution, we can add the processes, which can accelerate the convergence by interactions of candidate filters population with population of fitness predictors. Fitness predictor is a small subset of the training set and it is used to approximate the fitness of the candidate solutions. In this thesis, indirect encoding is used for predictors evolution. This encoding represents a mathematical expression, which selects training vectors for candidate filters fitness prediction. This approach was experimentally evaluated in the task of image filters for various intensity of random impulse and salt and pepper noise design and the design of the edge detectors. It was shown, that this approach leads to adapting the number of target objective vectors for a particular task, which leads to computational complexity reduction.
|
|
|
Parallelisation of Ultrasound Simulations Using Local Fourier Decomposition
Dohnal, Matěj ; Hrbáček, Radek (referee) ; Jaroš, Jiří (advisor)
This document introduces a brand new method of the 1D, 2D and 3D decomposition with the use of local Fourier basis, its implementation and comparison with the currently used global 1D domain decomposition. The new method was designed, implemented and tested primarily for future use in the simulation software called The k-Wave toolbox, but it can be applied in many other spectral methods. Compared to the global 1D domain decomposition, the Local Fourier decomposition is up to 3 times faster and more efficient thanks to lower inter-process communication, however it is a little inaccurate. The final part of the thesis discusses the limitations of the new method and also introduces best practices to use 3D Local Fourier decomposition to achieve both more speed and accuracy.
|
|
|
Exploitng sparse signal representations in capturing and recovery of nuclear magnetic resonance data
Hrbáček, Radek ; Zátyik, Ján (referee) ; Rajmic, Pavel (advisor)
This thesis deals with the nuclear magnetic resonance field, especially spectroscopy and spectroscopy imaging, sparse signal representation and low-rank approximation approaches. Spectroscopy imaging methods are becoming very popular in clinical praxis, however, long measurement times and low resolution prevent them from their spreading. The goal of this thesis is to improve state of the art methods by using sparse signal representation and low-rank approximation approaches. The compressed sensing technique is demonstrated on the examples of magnetic resonance imaging speedup and hyperspectral imaging data saving. Then, a new spectroscopy imaging scheme based on compressed sensing is proposed. The thesis deals also with the in vivo spectrum quantitation problem by designing the MRSMP algorithm specifically for this purpose.
|
guest ::
