729 research outputs found
Multiobjective optimization of electromagnetic structures based on self-organizing migration
Práce se zabĂ˝vá popisem novĂ©ho stochastickĂ©ho vĂcekriteriálnĂho optimalizaÄŤnĂho algoritmu MOSOMA (Multiobjective Self-Organizing Migrating Algorithm). Je zde ukázáno, Ĺľe algoritmus je schopen Ĺ™ešit nejrĹŻznÄ›jšà typy optimalizaÄŤnĂch Ăşloh (s jakĂ˝mkoli poÄŤtem kritĂ©riĂ, s i bez omezujĂcĂch podmĂnek, se spojitĂ˝m i diskrĂ©tnĂm stavovĂ˝m prostorem). VĂ˝sledky algoritmu jsou srovnány s dalšĂmi běžnÄ› pouĹľĂvanĂ˝mi metodami pro vĂcekriteriálnĂ optimalizaci na velkĂ© sadÄ› testovacĂch Ăşloh. Uvedli jsme novou techniku pro vĂ˝poÄŤet metriky rozprostĹ™enĂ (spread) zaloĹľenĂ© na hledánĂ minimálnĂ kostry grafu (Minimum Spanning Tree) pro problĂ©my majĂcĂ vĂce neĹľ dvÄ› kritĂ©ria. DoporuÄŤenĂ© hodnoty pro parametry Ĺ™ĂdĂcĂ bÄ›h algoritmu byly urÄŤeny na základÄ› vĂ˝sledkĹŻ jejich citlivostnĂ analĂ˝zy. Algoritmus MOSOMA je dále ĂşspěšnÄ› pouĹľit pro Ĺ™ešenĂ rĹŻznĂ˝ch návrhovĂ˝ch Ăşloh z oblasti elektromagnetismu (návrh Yagi-Uda antĂ©ny a dielektrickĂ˝ch filtrĹŻ, adaptivnĂ Ĺ™ĂzenĂ vyzaĹ™ovanĂ©ho svazku v ÄŤasovĂ© oblasti…).This thesis describes a novel stochastic multi-objective optimization algorithm called MOSOMA (Multi-Objective Self-Organizing Migrating Algorithm). It is shown that MOSOMA is able to solve various types of multi-objective optimization problems (with any number of objectives, unconstrained or constrained problems, with continuous or discrete decision space). The efficiency of MOSOMA is compared with other commonly used optimization techniques on a large suite of test problems. The new procedure based on finding of minimum spanning tree for computing the spread metric for problems with more than two objectives is proposed. Recommended values of parameters controlling the run of MOSOMA are derived according to their sensitivity analysis. The ability of MOSOMA to solve real-life problems from electromagnetics is shown in a few examples (Yagi-Uda and dielectric filters design, adaptive beam forming in time domain…).
Adaptive strategy for neural network synthesis constant estimation
Neural Network Synthesis is a new innovative method for an artificial neural network learning and structural optimization. It is based on two other already very successful algorithms: Analytic Programming and Self-Organizing Migration Algorithm (SOMA). The method already recorded several theoretical as well as industrial application to prove itself as a useful tool of modelling and simulation. This paper explores promising possibility to farther improve the method by application of an adaptive strategy for SOMA. The new idea of adaptive strategy is explained here and tested on a theoretical experimental case for the first time. Obtained data are statistically evaluated and ability of adaptive strategy to improve neural network synthesis is proved in conclusion
A new MDA-SOA based framework for intercloud interoperability
Cloud computing has been one of the most important topics in Information Technology which aims to assure scalable and reliable on-demand services over the Internet. The expansion of the application scope of cloud services would require cooperation between clouds from different providers that have heterogeneous functionalities. This collaboration between different cloud vendors can provide better Quality of Services (QoS) at the lower price. However, current cloud systems have been developed without concerns of seamless cloud interconnection, and actually they do not support intercloud interoperability to enable collaboration between cloud service providers. Hence, the PhD work is motivated to address interoperability issue between cloud providers as a challenging research objective.
This thesis proposes a new framework which supports inter-cloud interoperability in a heterogeneous computing resource cloud environment with the goal of dispatching the workload to the most effective clouds available at runtime.
Analysing different methodologies that have been applied to resolve various problem scenarios related to interoperability lead us to exploit Model Driven Architecture (MDA) and Service Oriented Architecture (SOA) methods as appropriate approaches for our inter-cloud framework. Moreover, since distributing the operations in a cloud-based environment is a nondeterministic polynomial time (NP-complete) problem, a Genetic Algorithm (GA) based job scheduler proposed as a part of interoperability framework, offering workload migration with the best performance at the least cost. A new Agent Based Simulation (ABS) approach is proposed to model the inter-cloud environment with three types of agents: Cloud Subscriber agent, Cloud Provider agent, and Job agent. The ABS model is proposed to evaluate the proposed framework.Fundação para a Ciência e a Tecnologia (FCT) - (Referencia da bolsa: SFRH SFRH / BD / 33965 / 2009) and EC 7th Framework Programme under grant agreement n° FITMAN 604674 (http://www.fitman-fi.eu
Design and Optimization of High-Torque Ferrite Assisted Synchronous Reluctance Motor
VysokomomentovĂ˝ asistovanĂ˝ synchronnĂ reluktanÄŤnĂ motor mĹŻĹľe bĂ˝t, soudÄ› podle nĂzkĂ©ho poÄŤtu publikovanĂ˝ch ÄŤlánkĹŻ, stále povaĹľován za relativnÄ› málo prozkoumanĂ© tĂ©ma vĂ˝zkumu. Tato ale i dalšà vĂ˝hody, jako nĂzká vĂ˝robnĂ cena a vysoká hustota vĂ˝konu poutajĂ pozornost vĂ˝zkumnĂ˝ch pracovnĂkĹŻ. Navzdory tomu, Ĺľe tento druh motoru je zajĂmavÄ›jšà z pohledu konvenÄŤnĂch nebo vysokootáčkovĂ˝ch aplikacĂ, tak se i trakÄŤnĂ aplikace dostávajĂ do popĹ™edĂ s tĂm, jak jsou objevovány vlastnosti tohoto motoru. Tato práce se zaměřuje na návrh tohoto typu motoru pro pohon lodi, kterĂ˝ je navrĹľen aby dosahoval vysokĂ©ho momentu pĹ™i nĂzkĂ˝ch otáčkách. Aplikace je definována vĂ˝konem 55 kW pĹ™i 150 otáčkách za minutu a pouĹľitĂm levnĂ˝ch feritovĂ˝ch magnetĹŻ s cĂlem nĂzkĂ© ceny motoru. Návrh motoru je Ăşzce propojen s optimalizaÄŤnĂmi algoritmy aby bylo dosaĹľeno co nejlepšĂho vĂ˝konu v danĂ©m objemu stroje. Navzdory tomu, Ĺľe návrh samotnĂ˝ je velice zajĂmavĂ˝m tĂ©matem, tak práce deklaruje dalšà teze, kterĂ© jsou rovněž zajĂmavĂ© a dĹŻleĹľitĂ©. Vzhledem k tomu, Ĺľe je práce zaměřena i na optimalizaci, tak prvnĂm cĂlem práce je porovnánĂ rĹŻznĂ˝ch optimalizaÄŤnĂch metod. V tĂ©to práci jsou nejenom Ĺľe rĹŻznĂ© druhy optimalizaÄŤnĂch algoritmĹŻ, samoorganizujĂcĂ migrujĂcĂ algoritmus a genetickĂ˝ algoritmus, porovnány, ale jsou zde porovnány i rĹŻznĂ© optimalizaÄŤnĂ metody. Metoda zaloĹľená na definovánĂ preferenÄŤnĂho vektoru a ideálnĂ multi-objektivnĂ metody jsou v rovněž v tĂ©to práci srovnány. Tyto algoritmy jsou srovnány v pĹ™ĂpadÄ› vĂce optimalizovanĂ˝ch parametrĹŻ. DalšĂm scĂ©nářem pro porovnánĂ ideálnĂch multi-objektivnĂch algoritmĹŻ je ten s menšĂm poÄŤtem parametrĹŻ. PoslednĂm cĂlem práce je laboratornĂ měřenĂ navrĹľenĂ©ho optimalizovanĂ©ho stroje, kterĂ© rovněž pĹ™edstavuje dalšà set vĂ˝zev v tĂ©to práci, kterĂ© jsou diskutovány v poslednĂ kapitole tĂ©to práce.The high-torque assisted synchronous reluctance machine could be still considered, based on the relatively low amount of publications, as a rather unknown area of research. This and other main advantages, such as low manufacturing cost and a higher torque density of this machine type are driving researchers interest. Even though this machine type has become more interesting in the conventional or high-speed applications, the area of traction applications is slowly getting forward as the machine capabilities are discovered. This thesis is serving just this purpose of developing the ship propulsion driving motor, that is capable of sustaining the high-torque at low-speed. The application is defined by the 55 kW at 150 rpm using the low- cost ferrite magnets aiming to lower the cost. The design will be closely tied with optimization algorithms to deliver the best possible performance in the given volume. However the design challenge being difficult task on its own, the thesis is declaring other goals within, that are still very interesting and important. Since the optimization is included in the design process, the first goal, concluding from the given topic is to compare various optimization methods. Not only the two different optimization algorithms, self-organizing migrating algorithm and genetic algorithm, will be compared in the thesis, but even two multi-objective optimization approaches will be compared as well. The preference based vector and ideal multi-objective optimization techniques comparison will be demonstrated in one optimization scenario with a higher amount of optimized parameters. Other demonstrated goal within the thesis is the comparison of ideal multi-objective optimization with a lower number of parameters. The last goal will be the measurement of the designed and optimized machine, that introduced variety of challenges itself and all of them will be discussed within the last chapter.
Programming a paintable computer
Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (p. 163-169).A paintable computer is defined as an agglomerate of numerous, finely dispersed, ultra-miniaturized computing particles; each positioned randomly, running asynchronously and communicating locally. Individual particles are tightly resource bound, and processing is necessarily distributed. Yet computing elements are vanishingly cheap and are regarded as freely expendable. In this regime, a limiting problem is the distribution of processing over a particle ensemble whose topology can vary unexpectedly. The principles of material self-assembly are employed to guide the positioning of "process fragments" - autonomous, mobile pieces of a larger process. These fragments spatially position themselves and reaggregate into a running process. We present the results of simulations to show that "process self-assembly" is viable, robust and supports a variety of useful applications on a paintable computer. We describe a hardware reference platform as an initial guide to the application domain. We describe a programming model which normatively defines the term process fragment and which provides environmental support for the fragment's mobility, scheduling and data exchange. The programming model is embodied in a simulator that supports development, test and visualization on a 2D particle ensemble. Experiments on simple combinations of fragments demonstrate robustness and explore the limits of scale invariance. Process fragments are shown interacting to approximate conservative fields, and using these fields to implement scaffolded and thermodynamic self-assembly.(cont.) Four applications demonstrate practical relevance, delineate the application domain and collectively illustrate the paintable's capacity for storage, communication and signal processing. These four applications are Audio Streaming, Holistic Data Storage, Surface Bus and Image Segmentation.by William Joseph Butera.Ph.D
ETL and analysis of IoT data using OpenTSDB, Kafka, and Spark
Master's thesis in Computer scienceThe Internet of Things (IoT) is becoming increasingly prevalent in today's society. Innovations in storage and processing methodologies enable the processing of large amounts of data in a scalable manner, and generation of insights in near real-time. Data from IoT are typically time-series data but they may also have a strong spatial correlation. In addition, many time-series data are deployed in industries that still place the data in inappropriate relational databases.
Many open-source time-series databases exist today with inspiring features in terms of storage, analytic representation, and visualization. Finding an efficient method to migrate data into a time-series database is the first objective of the thesis.
In recent decades, machine learning has become one of the backbones of data innovation. With the constantly expanding amounts of information available, there is good reason to expect that smart data analysis will become more pervasive as an essential element for innovative progress. Methods for modeling time-series data in machine learning and migrating time-series data from a database to a big data machine learning framework, such as Apache Spark, is explored in this thesis
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