142 resultados para machine theory


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A direct-driven permanent magnet synchronous machine for a small urban use electric vehicle is presented. The measured performance of the machine at the test bench as well as the performance over the modified New European Drive Cycle will be given. The effect of optimal current components, maximizing the efficiency and taking into account the iron loss, is compared with the simple id=0 – control. The machine currents and losses during the drive cycle are calculated and compared with each other.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The topic of the present doctoral dissertation is the analysis of the phonological and tonal structures of a previously largely undescribed language, namely Samue. It is a Gur language belonging to the Niger-Congo language phulym, which is spoken in Burkina Faso. The data were collected during the fieldwork period in a Sama village; the data include 1800 lexical items, thousands of elicited sentences and 30 oral texts. The data were first transcribed phonetically and then the phonological and tonal analyses were conducted. The results show that the phonological system of Samue with the phoneme inventory and phonological processes has the same characteristics as other related Gur languages, although some particularities were found, such as the voicing and lenition of stop consonants in medial positions. Tonal analysis revealed three level tones, which have both lexical and grammatical functions. A particularity of the tonal system is the regressive Mid tone spreading in the verb phrase. The theoretical framework used in the study is Optimality theory. Optimality theory is rarely used in the analysis of an entire language system, and thus an objective was to see whether the theory was applicable to this type of work. Within the tonal analysis especially, some language specific constraints had to be created, although the basic Optimality Theory principle is the universal nature of the constraints. These constraints define the well-formedness of the language structures and they are differently ranked in different languages. This study gives new insights about typological phenomena in Gur languages. It is also a fundamental starting point for the Samue language in relation to the establishment of an orthography. From the theoretical point of view, the study proves that Optimality theory is largely applicable in the analysis of an entire sound system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis studies the use of machine vision in RDF quality assurance and manufacturing. Currently machine vision is used in recycling and material detection and some commer- cial products are available in the market. In this thesis an on-line machine vision system is proposed for characterizing particle size. The proposed machine vision system is based on the mapping between image segmenta- tion and the ground truth of the particle size. The results shows that the implementation of such machine vision system is feasible.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Laser cutting implementation possibilities into paper making machine was studied as the main objective of the work. Laser cutting technology application was considered as a replacement tool for conventional cutting methods used in paper making machines for longitudinal cutting such as edge trimming at different paper making process and tambour roll slitting. Laser cutting of paper was tested in 70’s for the first time. Since then, laser cutting and processing has been applied for paper materials with different level of success in industry. Laser cutting can be employed for longitudinal cutting of paper web in machine direction. The most common conventional cutting methods include water jet cutting and rotating slitting blades applied in paper making machines. Cutting with CO2 laser fulfils basic requirements for cutting quality, applicability to material and cutting speeds in all locations where longitudinal cutting is needed. Literature review provided description of advantages, disadvantages and challenges of laser technology when it was applied for cutting of paper material with particular attention to cutting of moving paper web. Based on studied laser cutting capabilities and problem definition of conventional cutting technologies, preliminary selection of the most promising application area was carried out. Laser cutting (trimming) of paper web edges in wet end was estimated to be the most promising area where it can be implemented. This assumption was made on the basis of rate of web breaks occurrence. It was found that up to 64 % of total number of web breaks occurred in wet end, particularly in location of so called open draws where paper web was transferred unsupported by wire or felt. Distribution of web breaks in machine cross direction revealed that defects of paper web edge was the main reason of tearing initiation and consequent web break. The assumption was made that laser cutting was capable of improvement of laser cut edge tensile strength due to high cutting quality and sealing effect of the edge after laser cutting. Studies of laser ablation of cellulose supported this claim. Linear energy needed for cutting was calculated with regard to paper web properties in intended laser cutting location. Calculated linear cutting energy was verified with series of laser cutting. Practically obtained laser energy needed for cutting deviated from calculated values. This could be explained by difference in heat transfer via radiation in laser cutting and different absorption characteristics of dry and moist paper material. Laser cut samples (both dry and moist (dry matter content about 25-40%)) were tested for strength properties. It was shown that tensile strength and strain break of laser cut samples are similar to corresponding values of non-laser cut samples. Chosen method, however, did not address tensile strength of laser cut edge in particular. Thus, the assumption of improving strength properties with laser cutting was not fully proved. Laser cutting effect on possible pollution of mill broke (recycling of trimmed edge) was carried out. Laser cut samples (both dry and moist) were tested on the content of dirt particles. The tests revealed that accumulation of dust particles on the surface of moist samples can take place. This has to be taken into account to prevent contamination of pulp suspension when trim waste is recycled. Material loss due to evaporation during laser cutting and amount of solid residues after cutting were evaluated. Edge trimming with laser would result in 0.25 kg/h of solid residues and 2.5 kg/h of lost material due to evaporation. Schemes of laser cutting implementation and needed laser equipment were discussed. Generally, laser cutting system would require two laser sources (one laser source for each cutting zone), set of beam transfer and focusing optics and cutting heads. In order to increase reliability of system, it was suggested that each laser source would have double capacity. That would allow to perform cutting employing one laser source working at full capacity for both cutting zones. Laser technology is in required level at the moment and do not require additional development. Moreover, capacity of speed increase is high due to availability high power laser sources what can support the tendency of speed increase of paper making machines. Laser cutting system would require special roll to maintain cutting. The scheme of such roll was proposed as well as roll integration into paper making machine. Laser cutting can be done in location of central roll in press section, before so-called open draw where many web breaks occur, where it has potential to improve runability of a paper making machine. Economic performance of laser cutting was done as comparison of laser cutting system and water jet cutting working in the same conditions. It was revealed that laser cutting would still be about two times more expensive compared to water jet cutting. This is mainly due to high investment cost of laser equipment and poor energy efficiency of CO2 lasers. Another factor is that laser cutting causes material loss due to evaporation whereas water jet cutting almost does not cause material loss. Despite difficulties of laser cutting implementation in paper making machine, its implementation can be beneficial. The crucial role in that is possibility to improve cut edge strength properties and consequently reduce number of web breaks. Capacity of laser cutting to maintain cutting speeds which exceed current speeds of paper making machines what is another argument to consider laser cutting technology in design of new high speed paper making machines.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The subject of the thesis is automatic sentence compression with machine learning, so that the compressed sentences remain both grammatical and retain their essential meaning. There are multiple possible uses for the compression of natural language sentences. In this thesis the focus is generation of television program subtitles, which often are compressed version of the original script of the program. The main part of the thesis consists of machine learning experiments for automatic sentence compression using different approaches to the problem. The machine learning methods used for this work are linear-chain conditional random fields and support vector machines. Also we take a look which automatic text analysis methods provide useful features for the task. The data used for machine learning is supplied by Lingsoft Inc. and consists of subtitles in both compressed an uncompressed form. The models are compared to a baseline system and comparisons are made both automatically and also using human evaluation, because of the potentially subjective nature of the output. The best result is achieved using a CRF - sequence classification using a rich feature set. All text analysis methods help classification and most useful method is morphological analysis. Tutkielman aihe on suomenkielisten lauseiden automaattinen tiivistäminen koneellisesti, niin että lyhennetyt lauseet säilyttävät olennaisen informaationsa ja pysyvät kieliopillisina. Luonnollisen kielen lauseiden tiivistämiselle on monta käyttötarkoitusta, mutta tässä tutkielmassa aihetta lähestytään television ohjelmien tekstittämisen kautta, johon käytännössä kuuluu alkuperäisen tekstin lyhentäminen televisioruudulle paremmin sopivaksi. Tutkielmassa kokeillaan erilaisia koneoppimismenetelmiä tekstin automaatiseen lyhentämiseen ja tarkastellaan miten hyvin erilaiset luonnollisen kielen analyysimenetelmät tuottavat informaatiota, joka auttaa näitä menetelmiä lyhentämään lauseita. Lisäksi tarkastellaan minkälainen lähestymistapa tuottaa parhaan lopputuloksen. Käytetyt koneoppimismenetelmät ovat tukivektorikone ja lineaarisen sekvenssin mallinen CRF. Koneoppimisen tukena käytetään tekstityksiä niiden eri käsittelyvaiheissa, jotka on saatu Lingsoft OY:ltä. Luotuja malleja vertaillaan Lopulta mallien lopputuloksia evaluoidaan automaattisesti ja koska teksti lopputuksena on jossain määrin subjektiivinen myös ihmisarviointiin perustuen. Vertailukohtana toimii kirjallisuudesta poimittu menetelmä. Tutkielman tuloksena paras lopputulos saadaan aikaan käyttäen CRF sekvenssi-luokittelijaa laajalla piirrejoukolla. Kaikki kokeillut teksin analyysimenetelmät auttavat luokittelussa, joista tärkeimmän panoksen antaa morfologinen analyysi.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tutkimuksen tavoitteena oli selvittää keinoja parantaa tuottavuutta ja investointitehokkuutta kunnallisteknisissä töissä. Tutkimusmenetelmäksi valittiin konstruktiivinen tutkimusmenetelmä, jossa käytännölliseen ongelmaan luodaan teoriapohjan kautta ratkaisuehdotus. Työn teoriaosuus käsittelee palveluiden tuottavuutta ja sen mittaamista. Työn tuloksena syntyi excel-työkalu, jonka avulla on mahdollista tarkastella palveluntuottajan konekannan aiheuttamia kustannuksia ja tuottoja. Työkalu laskee konekohtaiset kustannukset ja tuotot, joiden avulla palveluntuottajalle on mahdollista osoittaa aiempien investointien kannattavuus. Työkalu laskee kustannus- ja tuottoarvion myös vaihtoehtoiselle konekannalle, jossa alhaisen käyttöasteen koneita korvataan monipuolisemmalla kalustolla. Palveluntuottajan konekannan hallinta ja kustannusrakenteen tarkka määrittely ovat tärkeässä roolissa tuottavuuden ja kannattavuuden kehittämisessä. Työkalu mahdollistaa myös eri kustannuserissä tapahtuvien muutosten vaikutusten arvioinnin, mikä auttaa palveluntuottajia toiminnan pitkäjänteisessä kehittämisessä.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Työn tavoitteena oli selvittää kaupallisen dynamiikansimulointiohjelmiston so-veltuvuus roottoridynamiikan analysointiin. Työssä keskityttiin erityisesti rootto-rin dynamiikkaan vaikuttavien epäideaalisuuksien mallintamiseen. Simulointitu-losten tarkkuutta selvitettiin mittauksilla. Lisäksi vertailtiin yleiskäyttöisen dyna-miikan simulointiohjelmiston ja roottoridynamiikan erikoisohjelmiston teoriaa. Tutkittava roottori oli paperikoneen putkitela. Telan joustavuus kuvattiin ele-menttimenetelmällä ratkaistujen moodien avulla. Elementtimallissa huomioitiin telan vaipan seinämänpaksuusvaihtelu, joka vaikuttaa telan massa- ja jäykkyysja-kaumaan. Dynamiikkaohjelmistossa mallinnettiin telan tuennasta tulevat herätteet. Dynamiikkaohjelmistona käytettiin ADAMS:ia ja FEM-ohjelmana ANSYS:stä. Tuloksista havaittiin käytetyn menetelmän soveltuvan roottoridynamiikan ana-lysointiin ja roottorin epäideaalisuuksien mallintamiseen. Simulointimallilla saa-tiin esille murtolukukriittiset pyörimisnopeudet ja telan kriittinen pyörimisnopeus vastasi hyvin mittaustuloksia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Optimization of quantum measurement processes has a pivotal role in carrying out better, more accurate or less disrupting, measurements and experiments on a quantum system. Especially, convex optimization, i.e., identifying the extreme points of the convex sets and subsets of quantum measuring devices plays an important part in quantum optimization since the typical figures of merit for measuring processes are affine functionals. In this thesis, we discuss results determining the extreme quantum devices and their relevance, e.g., in quantum-compatibility-related questions. Especially, we see that a compatible device pair where one device is extreme can be joined into a single apparatus essentially in a unique way. Moreover, we show that the question whether a pair of quantum observables can be measured jointly can often be formulated in a weaker form when some of the observables involved are extreme. Another major line of research treated in this thesis deals with convex analysis of special restricted quantum device sets, covariance structures or, in particular, generalized imprimitivity systems. Some results on the structure ofcovariant observables and instruments are listed as well as results identifying the extreme points of covariance structures in quantum theory. As a special case study, not published anywhere before, we study the structure of Euclidean-covariant localization observables for spin-0-particles. We also discuss the general form of Weyl-covariant phase-space instruments. Finally, certain optimality measures originating from convex geometry are introduced for quantum devices, namely, boundariness measuring how ‘close’ to the algebraic boundary of the device set a quantum apparatus is and the robustness of incompatibility quantifying the level of incompatibility for a quantum device pair by measuring the highest amount of noise the pair tolerates without becoming compatible. Boundariness is further associated to minimum-error discrimination of quantum devices, and robustness of incompatibility is shown to behave monotonically under certain compatibility-non-decreasing operations. Moreover, the value of robustness of incompatibility is given for a few special device pairs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this Master’s Thesis was to examine the determinants of intention and behavior of playing sports betting games in order to explain the intention to play in a more precise way and to be able to understand the behavior of playing. The theory of planned behavior was applied in explaining the intention of young Finnish adults aged 18 to 34. A quantitative research method was applied and an online survey was sent to the students of Lappeenranta University of Technology and to the subscribers of Urheilulehti in order to reach a sample that present the young population of Finland. The theory of the study focused on the theory of planned behavior and its antecedents, attitude towards behavior, subjective norms, perceived behavioral control as well as motivation. By analyzing the data, causal relationships were found through which the explanation of intention was possible. The results showed that attitude towards playing, subjective norms, perceived behavioral control and motivation impact the formation of intention significantly. The results also indicated that intention impacts significantly to the playing frequency.