• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 25
  • 7
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A*-Based Path Planning for an Unmanned Aerial and Ground Vehicle Team in a Radio Repeating Operation

Krawiec, Bryan Michael 30 May 2012 (has links)
In the event of a disaster, first responders must rapidly gain situational awareness about the environment in order to plan effective response operations. Unmanned ground vehicles are well suited for this task but often require a strong communication link to a remote ground station to effectively relay information. When considering an obstacle-rich environment, non-line-of-sight conditions and naive navigation strategies can cause substantial degradations in radio link quality. Therefore, this thesis incorporates an unmanned aerial vehicle as a radio repeating node and presents a path planning strategy to cooperatively navigate the vehicle team so that radio link health is maintained. This navigation technique is formulated as an A*-based search and this thesis presents the formulation of this path planner as well as an investigation into strategies that provide computational efficiency to the search process. The path planner uses predictions of radio signal health at different vehicle configurations to effectively navigate the vehicles and simulations have shown that the path planner produces favorable results in comparison to several conceivable naive radio repeating variants. The results also show that the radio repeating path planner has outperformed the naive variants in both simulated environments and in field testing where a Yamaha RMAX unmanned helicopter and a ground vehicle were used as the vehicle team. Since A* is a general search process, this thesis also presents a roadway detection algorithm using A* and edge detection image processing techniques. This algorithm can supplement unmanned vehicle operations and has shown favorable performance for images with well-defined roadways. / Master of Science
2

Computational Modeling and Impact Analysis of Textile Composite Structutres

Hur, Hae-Kyu 21 November 2006 (has links)
This study is devoted to the development of an integrated numerical modeling enabling one to investigate the static and the dynamic behaviors and failures of 2-D textile composite as well as 3-D orthogonal woven composite structures weakened by cracks and subjected to static-, impact- and ballistic-type loads. As more complicated modeling about textile composite structures is introduced, some of homogenization schemes, geometrical modeling and crack propagations become more difficult problems to solve. To overcome these problems, this study presents effective mesh-generation schemes, homogenization modeling based on a repeating unit cell and sinusoidal functions, and also a cohesive element to study micro-crack shapes. This proposed research has two: 1) studying behavior of textile composites under static loads, 2) studying dynamic responses of these textile composite structures subjected to the transient/ballistic loading. In the first part, efficient homogenization schemes are suggested to show the influence of textile architectures on mechanical characteristics considering the micro modeling of repeating unit cell. Furthermore, the structures of multi-layered or multi-phase composites combined with different laminar such as a sub-laminate, are considered to find the mechanical characteristics. A simple progressive failure mechanism for the textile composites is also presented. In the second part, this study focuses on three main phenomena to solve the dynamic problems: micro-crack shapes, textile architectures and textile effective moduli. To obtain a good solutions of the dynamic problems, this research attempts to use four approaches: I) determination of governing equations via a three-level hierarchy: micro-mechanical unit cell analysis, layer-wise analysis accounting for transverse strains and stresses, and structural analysis based on anisotropic plate layers, II) development of an efficient computational approach enabling one to perform transient response analyses of 2-D plain woven, 2-D braided and 3-D orthogonal woven composite structures featuring matrix cracking and exposed to time-dependent ballistic loads, III) determination of the structural characteristics of the textile-layered composites and their degraded features under smeared and discrete cracks, and assessment of the implications of stiffness degradation on dynamic response to impact loads, and finally, IV) the study of the micro-crack propagation in the textile/ceramic layered plates. A number of numerical models have been carried out to investigate the mechanical behavior of 2-D plain woven, 2-D braided and 3-D orthogonal woven textile composites with several geometrical representations, and also study the dynamic responses of multi-layered or textile layered composite structures subjected to ballistic impact penetrations with a developed in-house code. / Ph. D.
3

Repeating and the Financial Cost of Teaching Repeaters in the Kingsville, Texas, Public Schools

Bacon, Carl T. 08 1900 (has links)
The purpose of this problem is to determine the financial cost of repeating students who failed during a five-year period in the Kingsville Public Schools, and to determine if this expenditure is justified.
4

Fermo / Fermo

Vidrinskaitė, Gabija 03 July 2014 (has links)
Kasdienis veiksmo kartojimas formos paieškų sėkmės labui tapo pagrindine darbo tema: ką daryti su vizualių bei rašytinių išraiškų kiekybe? Asmeniniai įrašai, atrinkti ir persipynę su Paul Klee, Eugene Delacroix bei Edvard Munch dienoraščių analize autorei rūpimais aspektais, įgavo „Sąsiuvinio nr. 4“ – rašto darbo formą, bylojančią apie kūrybinių procesų įtakas ir ištakas. Estampai bei savaitiniai piešiniai susivienijo kolekcijoje „Fermo“, Išvertus iš Esperanto kalbos – uždarymas, baigimas. Baigiamasis darbas – tai neišvengiamai pasikartojančių vaizdinių ir verbalių išraiškų, surinktų paskutiniųjų mokslo metų Vilniaus dailės akademijoje metu, sintezė. / The repetition of a daily action for the sake of luck in a form reaserch became the main problem of the work: what to do with the amount of visual and written expressions? Selected personal entries overlapped with Paul Klee, Eugene Delacroix and Edvard Munch diaries analysies gained a form of „Jounal nr. 4“ – a written work, pointing the interests and outflows of the working processes. The prints and weekly drawings united in a collection „Fermo“. The comlplete work is a sythesis of necesarilly repetitive pictorial and verbal expresions, collected during the last years of studies in Vilnius Academy of Arts.
5

Dailininkų dienoraščiai. Sąsiuvinis Nr. 4 / Artists' Diaries. Journal No. 4

Vidrinskaitė, Gabija 03 July 2014 (has links)
Pasiklydau temų miške vieną dieną. Kiekviena smulkmena atrodė įdomi ir verta aptarimo... Kad suprasčiau, kas man iš tiesų rūpi, nusprendžiau rašyti dienoraštį. Susikūriau sau užduotį – rašyti dienoraštį kas dieną ir taip visą mėnesį. Mėnesis praėjo, o karuselė vis dar sukosi. Reikėjo naujos užduoties... Išvažiavus į Švediją atlikti praktikos, užsivedžiau naują sąsiuvinį ir pildžiau jį du mėnesius. Praktika baigėsi, grįžau į savo šalį. Negalėjau nustoti rašiusi, jaučiau, jog tai mano darbo dalis. Kai sutikau tris žymius nepažįstamuosius – Eugenijų Delakrua, Paulių Klė ir Edvardą Munchą ir pradėjau skaityti jų dienoraščius, užsivedžiau naują sąsiuvinį ant viršelio užrašiusi „Nr. 4“. Šie dailininkai savo dienoraščiuose pasiūlė naujų žiūrėjimo taškų į savo pačios dienoraščio rašymą bei kūrybą. Tai buvo akstinas rūpestingam dailininko dienoraščio svarstymui. / One day I felt lost in the forest of topics. Every single thing seemed to be interesting and worth to discuss… I decided to write a diary to understand what is the most important to me. I started with a task – to write a diary every day for a period of a month. The month ended, but the carousel was still spinning. I needed a new task. I was writing my second journal during the practice in foreign country for two months, also every day. The practice was finished – I could not stop writing – It was a part of my work I felt. I took a blank Journal and wrote "No. 4" on the cover when I met three famous strangers and started to read their diaries - Edvard Munch, Paul Klee and Eugene Delacroix. They offered me new perspectives on my own writing and working. It was the reason to start with a serious discussion about the diaries of artists.
6

A Position-Join Method for Finding Maximum-Length Repeating Patterns in Music Databases

Chen, Tien-hsiu 12 July 2011 (has links)
In recent years, the music has become popular due to the evolution of the technology. Various kinds of music around us become complexities and huge. The explosive growth in the music has generated the urgent need for new techniques and tools that can intelligently and automatically transform the music into useful information. Many researches consider the music object as an continuously discrete note in time order. Repeating patterns are some subsequences which appear frequently in the music sequence. The repeating patterns usually can represent the theme of a music object. Moreover, it also can be utilized in music classification. Many methods have been proposed for finding the repeating patterns in music objects, for example, the M2P (Mining Maximum-length Patterns) method. It constructs a directed graph and uses the depth-first search to traverse the graph. It calculates the paths by the string matching algorithm to decide whether they are repeating pattern, and finds out the maximum-length repeating pattern in a music sequence. Although the M2P method is a straightforward method to find out the patterns, it consumes time in creating too many candidate patterns and performing the string matching algorithm. Therefore, in this thesis, we propose the PJ (Position-Join) method to efficiently find out the maximum-length repeating pattern. In the constructing graph step, we find out that we can modify the information in the graph, and avoid to use the string matching algorithm to decide whether a path is repeating pattern. We record the positions of length two repeating patterns in the matrix. While traversing the graph, we calculate the frequency by the information of positions. Moreover, we record the repeated path by the positions. We create terminal edges, and record the information of paths which have been traversed. We dynamically modify the graph by terminal edges. It can avoid to traverse some paths repeatedly in traversing the graph step. From our performance study based on the synthetic data and real music data, we show that our proposed PJ method is more efficient than the M2P method.
7

Glissements sismiques et asismiques : le cas du Japon / Seismic and aseismic slip : the Japanese subduction zone

Gardonio, Blandine 02 March 2017 (has links)
L'existence de glissements lents a été observé pour la première fois en Californie, sur une portion de la faille de San Andreas (Steinbrugge et al., 1960,Tocher 1960). Ils ont ensuite été détéctés dans les années 90s avec l'avènement des GPS. Les interactions entre glissement lents, ou glissements asismiques (qui n'émettent pas d'ondes élastiques) et les glissements sismiques est cependant mal connue.Pourtant, cette question est fondamentale puisque des glissements lents ont été observés avant plusieurs séismes.Par exemple, l’installation d’un glissement lent avant le séisme d’Izmit de 1999 en Turquie a été mise en évidence grâce à l’analyse de signaux répétitifs (Bouchon et al., 2011). De même, en étudiant le comportement des séismes répétitifs avant le méga-séisme de Tohoku de 2011, deux séquences de glissement lent en direction du point d’initiation ont été observées (Kato et al., 2012). D’autres glissements lents précédents des séismes de grandes ampleurs ont été reportés, notamment au Mexique, avant le séisme de Papanoa (Radiguet et al., 2016) de magnitude 7.3 et au Chili, avant le séisme d’Iquique de 2014 de magnitude 8.2 (Ruiz et al., 2014).L'objectif de ce travail de thèse est de mieux caractériser les interactions qui existent entre glissements sismiques et asismiques dans une zone de subduction très largement instrumentée: le Japon.La très grande densité des réseaux Japonais (sismique courte et longue période, GPS) autorise des seuils de détection des glissements sismiques ou lents très bas, et permet d'utiliser des méthodes de réseaux afin de maximiser le rapport signal sur bruit. La recherche d'épisodes de déformation lente est basée sur plusieurs types d'observables et de méthodes, et est complétée par l'analyse des changements de taux de sismicité accompagnant ces épisodes. Cette thèse vise ainsi à mieux comprendre comment du glissement lent peut -ou non- accélérer l'occurrence de grands séismes, et les conditions requises pour se faire. / Transient aseismic slip events (that do not emit elastic waves) were first discovered on the San Andreas fault in central California in 1960 (Steinbrugge et al., 1960, Tocher 1960) and were later confirmed by the development and installation of GPS stations. Aseismic slip can occur on continental faults as well as on subduction zones. However, the interactions between aseismic and seismic slips are not fully captured yet. Understanding the mechanisms at stake on fault planes is fundamental since several large earthquakes were preceded by aseismic slip episodes.For example, the setting of a slow slip event before the 1999 Izmit earthquake in Turkey was evidenced by the observation of repeating signals at one station (Bouchon et al., 2011). Also, by studying repeating earthquakes before the 2011 Tohoku earthquake, two slow slip episodes that migrated towards the rupture intitiation were observed (Kato et al., 2012). Other transient slips preceding large earthquakes occurred, including in Mexico, before the M7.3 Papanoa earthquake (Radiguet et al., 2016) and in Chile, before the 2014 Iquique earthquake (Ruiz et al., 2014).The aim of this thesis is to better characterize the interactions between seismic and aseismic slip that can occur in a subduction zone largely instrumented: Japan.The very high density of the japanese monitoring networks(seismic networks, both at short and long periods, and GPS network), allows the detection ofseismic and aseismic slip events with low intensity / size, and is amenable to the use of arraymethods to improve the signal-to-noise ratio. The search for episodes of transient deformation will be based on several observables andtechniques, and is complemented by the analysis of the changes in earthquake rates concomittent to these episodes. This work thus gives new clues on how aseismic deformation can -or not- accelerate the occurrence of strong earthquakes, and on what are the conditions (tectonic, dynamic) for this to happen.
8

Elevers uppfattningar av mönster : En kvalitativ studie om hur elever i årskurs 1 uppfattar upprepade och växande geometriska mönster / Pupils perceptions of pattern : A qualitative study on how pupils in grade 1 perceive patterns

Debreceni, Hanna January 2017 (has links)
Arbetet med mönster, genom dess innehållande av strukturer och samband, är en betydelsefull del inom området algebra. Genom att bedriva undervisning i de lägre årskurserna om matematiska mönster kan elever få en god grund att stå på i mötet med den mer komplexa algebran. Studien är en kvalitativ intervjustudie med inspiration av fenomenografi, där elever i årskurs 1 ombeds att lösa ett antal uppgifter om upprepade samt växande geometriska mönster. Utifrån denna metod syftar studien till att bidra med kunskap om hur elever i de yngre åldrarna uppfattar matematiska mönster. Genom detta syfte, bidrar studien också till förståelse för vad det finns för kritiska aspekter i samband med erfarandet av de två mönstertyperna. När kunskap om ovannämnda delar finns tillhands, kan lärare designa undervisning på ett sätt som gynnar elevers lärande.  Resultatet påvisar ett antal kritiska aspekter i samband med förståelsen av upprepade och växande geometriska mönster. Det kan vara kritiskt att identifiera den upprepade delen i ett upprepat mönster och att fortsätta ett upprepat mönster enligt samma struktur. Vidare kan det vara kritiskt att urskilja en växande struktur och ett regelbundet numeriskt samband i de växande mönstren. Upptäcka ett generellt samband i ett växande geometriskt mönster är ytterligare en kritisk aspekt som framkommer i studien.  Elever uppfattar mönster på många skilda sätt, vilket lärare bör ha i åtanke då de planerar och genomför undervisning. Det finns viktiga aspekter som bör synliggöras i undervisningen så att elever kan utveckla en förståelse för upprepade och växande mönster. / The work of patterns, through its content of structures and relationships, is an important part in the area of algebra. Teaching pupils in the lower grades about mathematical patterns, helps them to understand the more complex algebra. The study is a qualitative interview study inspired by phenomenography, where pupils in grade 1 were asked to solve a number of tasks related to repeating as well as growing geometric patterns. Based on this method, the study aims to contribute knowledge about how pupils in the younger ages perceive mathematical patterns. In connection with the purpose of this study it also contributes to the understanding about what the critical aspects connected to the two types of patterns could be. Once knowledge of the above-mentioned parts is available, teachers can design their education in a way that benefits pupils' learning. The result shows a number of critical aspects associated with the understanding of repeating and growing patterns. It may be critical to identify the repeating part in a repeated pattern and to continue a repeated pattern according to the same structure. Furthermore, it may be critical to distinguish a growing structure and a regular numerical connection in the growing patterns. Discovering a general relationship in a growing geometric pattern is another critical aspect that appears in the study. Pupils perceive patterns in many different ways, which teachers should keep in mind when planning and conducting teaching. There are important aspects that should be made visible in the education so that pupils can develop an understanding of repeating and growing patterns.
9

Geometriska mönster i Favorit matematik : En läromedelsgranskning av Favorit matematik i årskurserna 1-3 / Geometric patterns in Favorit matematik : A teaching material study of Favorit matematik in primary grades

Axelsson, Johanna January 2017 (has links)
Algebra i matematik kan handla om så mycket mer än svåra ekvationer och beräkningar. I de yngre åldrarna, åk 1-3, är geometriska mönster en del av det centrala innehållet i algebra. Genom att arbeta med mönster förbereder vi eleverna inför den svårare algebran och de lär sig att uttrycka sig generellt. Många studier visar fördelarna med mönster i tidiga åldrar, exempelvis lär sig eleverna se samband och även att göra generaliseringar.   Denna studie är en läromedelsgranskning av läromedlet Favorit matematik i årskurserna 1-3. Syftet är att bidra med kunskap kring vilka matematiska förmågor eleverna ges utrymme att utveckla vid arbetet med mönster i Favorit matematik. Fokus ligger även på att undersöka vilken av mönstertyperna, upprepade mönster och växande geometriska mönster, som behandlas mest. Metoden som har använts är en tabell där mönstertyperna och förmågorna skrevs in.   Resultatet visar på brister när det handlar om arbete med mönster i Favorit matematik. Läraren måste i sin undervisning arbeta med mönster utanför läroboken för att alla förmågor ska få utrymme. Det visas inte heller på att mönster är något inom algebra utan det kopplas mestadels till andra områden i det centrala innehållet i kursplanen. De flesta uppgifterna i läroböckerna handlade om att fortsätta på ett mönster som var ett upprepat mönster. Därför kopplades merparten av uppgifterna till den första matematiska förmågan som handlar om att lösa problem och värdera sina strategier och metoder. Resultatet visar också att växande geometriska mönster inte behandlas mycket i Favorit matematik. / Algebra in mathematics is so much more than just equations and calculations. Through the primary grades in school, geometric patterns are a part of the Swedish curriculum. By working with patterns we prepare the students for the more difficult algebra to come, and they learn to express themselves generally. Many studies show the benefits with the work with patterns in the primary grades, for example students learn how to see connections and how to generalise.   This study is a teaching material study of the material Favorit matematik in the primary grades. The aim is to contribute knowledge about which mathematical abilities students are given chance to develop by working with patterns in Favorit matematik. Focus is also to study what type of pattern, of repeating patterns and growing patterns, that are more processed in the material. The method that has been used is a chart where the patterns and the abilities were written into.   The result shows flaws when it comes to patterns in Favorit matematik. The teacher has to work with this along with the material to give the students chance to explore every mathematical ability. Nor is it shown that patterns are something within the algebra, it is mostly linked to other areas from the curriculum. Mostly the exercises were about completing a pattern that was repeating, and therefore the majority of the exercises was connected to the first ability, which is about solving problems and evaluate your strategies and methods. The result also shows that growing geometric patterns is not presented as much as repeating patterns.
10

Characterizing induced and natural earthquake swarms using correlation algorithms

Skoumal, Robert J. 13 April 2016 (has links)
No description available.

Page generated in 0.0603 seconds