CONTROLLED GPS DATA TRANSFER FROM MOBILE DEVICES TO SERVER

Diplomska naloga opisuje razvoj Android aplikacije in strežnika ter vso uporabljeno tehnologijo. Predstavljen je koordiniran prenos GPS (ang. Global Positioning System) podatkov iz mobilne naprave do strežnika. Aplikacija pridobi GPS podatke naprave in jih pošlje strežniku, ki te podatke prejema. Strežnik bo tudi krmilil hitrost pošiljanja GPS podatkov s telefona na strežnik. Implementiran sistem tako omogoča uporabo GPS podatkov v različne namene.The thesis describes the development of an Android application and server, and all the technology used. Described is a coordinated transfer of GPS (Global Positioning System) data from mobile devices to the server. The application obtains GPS data from the device and sends it to a server that receives this data. The server also controls the speed at which the GPS data will be sent from the device to the server. The implemented system enables the use of GPS data for different purposes

A Chess Rating System for the Comparison of Multi-Objective Evolutionary Algorithms

Evolucijski algoritmi večkriterijske optimizacije so bili uspešno uporabljeni za reševanje realnih večkriterijskih problemov, kar pojasnjuje tudi njihovo popularnost. Ocenjevanje in primerjava evolucijski algoritmi večkriterijske optimizacije je pomembno vprašanje. Vendar izvajanje primerjav evolucijskih algoritmov ni trivialna naloga. Algoritmi imajo številne kontrolne parametre, ki jih je potrebno konfigurirati. Izbrati je treba primerne testne probleme in rezultate analizirati z uporabo statistične metode. Poleg tega lahko rezultate evolucijskih algoritmov večkriterijske optimizacije ocenimo z različnimi indikatorji kakovosti, kar še dodatno otežuje primerjavo. Da bi olajšali proces primerjave smo, v doktorski disertaciji predstavili metodo za primerjavo in uglaševanje evolucijskih algoritmov večkriterijske optimizacije. Najprej je bila opravljena analiza indikatorjev kakovosti, ki je pokazala, da lahko z indikatorji, ki merijo enake aspekte kakovosti, dobimo statistično značilne razlike. Dobili smo tudi nabor robustnih in konsistentnih indikatorjev. Za primerjavo algoritmov smo uporabili šahovski sistem rangiranja, ki je bil prilagojen za algoritme večkriterijske optimizacije z ansamblom indikatorjev kakovosti. V ansambel smo vključili najprimernejše indikatorje iz predhodne analize. Rezultati so pokazali, da je predlagana metoda dosegla primerljive rezultate s primerljivimi metodami z manjšim številom zagonov posameznega algoritma. Ker je uspešnost evolucijskih algoritmov lahko zelo odvisna od konfiguracije kontrolnih parametrov, smo predlagano metodo nadgradili tako, da omogoča uglaševanje. Rezultati eksperimenta so pokazali veliko izboljšanje algoritmov po izvedenem uglaševanju s predlagano metodo. Z uporabo uglaševanja zagotovimo, da imajo algoritmi primernejše kontrolne parametre in posledično je tudi primerjava bolj poštena.Evolucijski algoritmi večkriterijske optimizacije so bili uspešno uporabljeni za reševanje realnih večkriterijskih problemov, kar pojasnjuje tudi njihovo popularnost. Ocenjevanje in primerjava evolucijski algoritmi večkriterijske optimizacije je pomembno vprašanje. Vendar izvajanje primerjav evolucijskih algoritmov ni trivialna naloga. Algoritmi imajo številne kontrolne parametre, ki jih je potrebno konfigurirati. Izbrati je treba primerne testne probleme in rezultate analizirati z uporabo statistične metode. Poleg tega lahko rezultate evolucijskih algoritmov večkriterijske optimizacije ocenimo z različnimi indikatorji kakovosti, kar še dodatno otežuje primerjavo. Da bi olajšali proces primerjave smo, v doktorski disertaciji predstavili metodo za primerjavo in uglaševanje evolucijskih algoritmov večkriterijske optimizacije. Najprej je bila opravljena analiza indikatorjev kakovosti, ki je pokazala, da lahko z indikatorji, ki merijo enake aspekte kakovosti, dobimo statistično značilne razlike. Dobili smo tudi nabor robustnih in konsistentnih indikatorjev. Za primerjavo algoritmov smo uporabili šahovski sistem rangiranja, ki je bil prilagojen za algoritme večkriterijske optimizacije z ansamblom indikatorjev kakovosti. V ansambel smo vključili najprimernejše indikatorje iz predhodne analize. Rezultati so pokazali, da je predlagana metoda dosegla primerljive rezultate s primerljivimi metodami z manjšim številom zagonov posameznega algoritma. Ker je uspešnost evolucijskih algoritmov lahko zelo odvisna od konfiguracije kontrolnih parametrov, smo predlagano metodo nadgradili tako, da omogoča uglaševanje. Rezultati eksperimenta so pokazali veliko izboljšanje algoritmov po izvedenem uglaševanju s predlagano metodo. Z uporabo uglaševanja zagotovimo, da imajo algoritmi primernejše kontrolne parametre in posledično je tudi primerjava bolj pošten

A CHESS RATING SYSTEM FOR THE COMPARISON OF MULTI-OBJECTIVE EVOLUTIONARY ALGORITHMS

Magistrsko delo obravnava primerjavo evolucijskih algoritmov večkriterijske optimizacije z uporabo šahovskega rangiranja. Na začetku je opisano šahovsko rangiranje in osnovni pojmi večkriterijske optimizacije. Prikazana je nadgradnja orodja EARS (ang. Evolutionary Algorithms Rating System), ki omogoča ocenjevanje uspešnosti evolucijskih algoritmov za enokriterijsko optimizacijo. Predstavljena je implementacija primernih primerjalnih funkcij in nabora preizkusnih problemov. Prav tako so predstavljeni tudi nekateri bolj znani evolucijski algoritmi večkriterijske optimizacije, ki smo jih vključili v orodje EARS. Na koncu so prikazani rezultati in primerjava rezultatov orodja EARS z drugimi metodami.In this thesis the comparison of multi-objective evolutionary algorithms using chess ranking is presented. First, the chess ranking and the basic concepts of multi-objective optimization are described. Then the upgrade of EARS (Evolutionary Algorithms Rating System), which enables the assessment of the performance of evolutionary algorithms for single-objective optimization is presented. The implementation of appropriate comparator functions and a set of test problems is also presented. Some of more well-known evolutionary algorithms of multi-objective optimization which were included in EARS are shown. Finally, the results and the comparison of EARS results with other methods are outlined

Tuning Multi-Objective Evolutionary Algorithms on Different Sized Problem Sets

Multi-Objective Evolutionary Algorithms (MOEAs) have been applied successfully for solving real-world multi-objective problems. Their success can depend highly on the configuration of their control parameters. Different tuning methods have been proposed in order to solve this problem. Tuning can be performed on a set of problem instances in order to obtain robust control parameters. However, for real-world problems, the set of problem instances at our disposal usually are not very plentiful. This raises the question: What is a sufficient number of problems used in the tuning process to obtain robust enough parameters? To answer this question, a novel method called MOCRS-Tuning was applied on different sized problem sets for the real-world integration and test order problem. The configurations obtained by the tuning process were compared on all the used problem instances. The results show that tuning greatly improves the algorithms’ performance and that a bigger subset used for tuning does not guarantee better results. This indicates that it is possible to obtain robust control parameters with a small subset of problem instances, which also substantially reduces the time required for tuning

From Grammar Inference to Semantic Inference—An Evolutionary Approach

This paper describes a research work on Semantic Inference, which can be regarded as an extension of Grammar Inference. The main task of Grammar Inference is to induce a grammatical structure from a set of positive samples (programs), which can sometimes also be accompanied by a set of negative samples. Successfully applying Grammar Inference can result only in identifying the correct syntax of a language. With the Semantic Inference a further step is realised, namely, towards inducing language semantics. When syntax and semantics can be inferred, a complete compiler/interpreter can be generated solely from samples. In this work Evolutionary Computation was employed to explore and exploit the enormous search space that appears in Semantic Inference. For the purpose of this research work the tool LISA.SI has been developed on the top of the compiler/interpreter generator tool LISA. The first results are encouraging, since we were able to infer the semantics only from samples and their associated meanings for several simple languages, including the Robot language

Long Term Memory Assistance for Evolutionary Algorithms

Short term memory that records the current population has been an inherent component of Evolutionary Algorithms (EAs). As hardware technologies advance currently, inexpensive memory with massive capacities could become a performance boost to EAs. This paper introduces a Long Term Memory Assistance (LTMA) that records the entire search history of an evolutionary process. With LTMA, individuals already visited (i.e., duplicate solutions) do not need to be re-evaluated, and thus, resources originally designated to fitness evaluations could be reallocated to continue search space exploration or exploitation. Three sets of experiments were conducted to prove the superiority of LTMA. In the first experiment, it was shown that LTMA recorded at least 50 % more duplicate individuals than a short term memory. In the second experiment, ABC and jDElscop were applied to the CEC-2015 benchmark functions. By avoiding fitness re-evaluation, LTMA improved execution time of the most time consuming problems F 03 and F 05 between 7% and 28% and 7% and 16%, respectively. In the third experiment, a hard real-world problem for determining soil models’ parameters, LTMA improved execution time between 26% and 69%. Finally, LTMA was implemented under a generalized and extendable open source system, called EARS. Any EA researcher could apply LTMA to a variety of optimization problems and evolutionary algorithms, either existing or new ones, in a uniform way

A Graph Pointer Network-Based Multi-Objective Deep Reinforcement Learning Algorithm for Solving the Traveling Salesman Problem

Traveling Salesman Problems (TSPs) have been a long-lasting interesting challenge to researchers in different areas. The difficulty of such problems scales up further when multiple objectives are considered concurrently. Plenty of work in evolutionary algorithms has been introduced to solve multi-objective TSPs with promising results, and the work in deep learning and reinforcement learning has been surging. This paper introduces a multi-objective deep graph pointer network-based reinforcement learning (MODGRL) algorithm for multi-objective TSPs. The MODGRL improves an earlier multi-objective deep reinforcement learning algorithm, called DRL-MOA, by utilizing a graph pointer network to learn the graphical structures of TSPs. Such improvements allow MODGRL to be trained on a small-scale TSP, but can find optimal solutions for large scale TSPs. NSGA-II, MOEA/D and SPEA2 are selected to compare with MODGRL and DRL-MOA. Hypervolume, spread and coverage over Pareto front (CPF) quality indicators were selected to assess the algorithms’ performance. In terms of the hypervolume indicator that represents the convergence and diversity of Pareto-frontiers, MODGRL outperformed all the competitors on the three well-known benchmark problems. Such findings proved that MODGRL, with the improved graph pointer network, indeed performed better, measured by the hypervolume indicator, than DRL-MOA and the three other evolutionary algorithms. MODGRL and DRL-MOA were comparable in the leading group, measured by the spread indicator. Although MODGRL performed better than DRL-MOA, both of them were just average regarding the evenness and diversity measured by the CPF indicator. Such findings remind that different performance indicators measure Pareto-frontiers from different perspectives. Choosing a well-accepted and suitable performance indicator to one’s experimental design is very critical, and may affect the conclusions. Three evolutionary algorithms were also experimented on with extra iterations, to validate whether extra iterations affected the performance. The results show that NSGA-II and SPEA2 were greatly improved measured by the Spread and CPF indicators. Such findings raise fairness concerns on algorithm comparisons using different fixed stopping criteria for different algorithms, which appeared in the DRL-MOA work and many others. Through these lessons, we concluded that MODGRL indeed performed better than DRL-MOA in terms of hypervolumne, and we also urge researchers on fair experimental designs and comparisons, in order to derive scientifically sound conclusions