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  • 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.
11

Εκτίμηση της ζήτησης των νοικοκυριών για ηλεκτρικό ρεύμα στην Ελλάδα

Στρατή, Αναστασία 01 July 2014 (has links)
Στην παρούσα έρευνα εκτιμήθηκε η επίδραση του κατά κεφαλήν εισοδήματος, της τιμής του ηλεκτρισμού και της τιμής του ακατέργαστου πετρελαίου στην ζήτηση ηλεκτρικού ρεύματος στην Ελλάδα και συγκεκριμένα στον τομέα των νοικοκυριών. Τα δεδομένα που εισήχθησαν στο οικονομετρικό μοντέλο αφορούσαν την περίοδο 1981 έως 2010. Για την εκτίμηση των βραχυχρόνιων και μακροχρόνιων επιδράσεων των ανεξάρτητων μεταβλητών επί της εξαρτημένης εφαρμόστηκαν δύο μέθοδοι, η Engle Granger two step method και η ARDL . Τα αποτελέσματα που προέκυψαν από την έρευνα έδειξαν ότι οι μακροχρόνιες επιδράσεις όλων των ανεξάρτητων μεταβλητών βρέθηκαν στατιστικά σημαντικές στο επίπεδο σημαντικότητας 0.05. Συγκεκριμένα η επίδραση του εισοδήματος βρέθηκε θετική ενώ των τιμών ηλεκτρισμού και πετρελαίου αρνητικές. Βραχυχρόνια βρέθηκε ότι στη ζήτηση του ηλεκτρισμού επιδρά σημαντικά η τιμή του πετρελαίου σύμφωνα και με τις δύο μεθόδους και το κεφαλήν εισόδημα σύμφωνα μόνο με την μέθοδο Engle Granger. Τέλος οι μακροχρόνιες ελαστικότητες βρέθηκαν μεγαλύτερες από τις αντίστοιχες βραχυχρόνιες. / The present study estimates the effect of GDP per capita, electricity price and oil price on the residential electricity demand in Greece. The annual data that has been used in the econometric model is from the period 1981 to 2010. Two techniques have been used for the estimation of the long run and short run effects of the independent variables on the dependent, Engle Granger two step method and ARDL method. The results that have been found from the study show that long run effects of all independent variables are statistically significant at the 0.05 significant level. The effect of electricity price and oil price has been found negative and the effect of GDP per capita has been found positive. More specifically, in the short run period only oil price elasticity has been found statistically significant according to the two methods and income elasticity has been found statistically significant only according to Error Correction Model. In addition long run elasticities have been found to be larger than the short run elasticities.
12

Εξέλιξη ή δημιουργία; : περιγραφή, μελέτη, ανάλυση και φιλοσοφική οριοθέτηση ενός διλήμματος

Μοσχόπουλος, Χαρίλαος 21 July 2015 (has links)
Η παρούσα εργασία πραγματεύεται ορισμένες όψεις της αντιπαράθεσης αναφορικά με τη γενεσιουργό αιτία της εμφάνισης και διαμόρφωσης της ζωής στην γη. Η αντιπαράθεση διαρθρώνεται, εκ πρώτης όψεως, στον άξονα του διλημματικού δίπολου Εξέλιξη ή Δημιουργία. Ως κύριες ερμηνευτικές προσεγγίσεις, εξετάζονται κατά σειρά ο δημιουργισμός, η εξελικτική θεωρία και η θεωρία του ευφυούς σχεδιασμού. Συγκεκριμένα, επιχειρείται να οριοθετηθεί το επιστημολογικό και εν γένει φιλοσοφικό πλαίσιο των εν λόγω θεωριών και να επισημανθούν οι κύριοι άξονες της σχετικής επιχειρηματολογίας. / This paper discusses some aspects of the debate regarding the root cause of the emergence and formation of life on earth. The debate is structured, prima facie, on the dipole between Evolution and Creation. The main interpretative approaches are examined: creationism, evolutionary theory and the theory of intelligent design. Specifically, the aim is to define the epistemological and generally philosophical context of these theories and to identify the main points of the relevant argumentation.
13

Upprätta processbeskrivning och utvärdera processtabilitet för en fermenteringsprocess

Hofling, Ann January 2008 (has links)
Inledning Vid Unitech Biopharma, Matfors (Sverige) sker tillverkning av rekombinant Kolera Toxin subenhet B (rCTB-213), vilket är en av de aktiva substanserna i vaccinet Dukoral®. Unitech Biopharma AB är ett bioteknikföretag fokuserade på legotillverkning av rekombinanta proteiner och tillverkar rCTB för SBL Vaccin AB Solna, (Sverige). Anläggningen där tillverkningen av denna produkt sker har alla nödvändiga tillstånd (Läkemedelsverket, Länsstyrelsen, Arbetsmiljöverket) och uppfyller gällande cGMP-krav samt är godkänd av läkemedelsmyndigheterna i EU och Kanada, WHO samt i ytterligare ca 35 andra länder. Dukoral® är ett drickbart vaccin som stimulerar immunförsvaret i tarmen och skapar ett bra skydd mot sjukdomen kolera. Vaccinet ger även skydd mot enterotoxinbildande stammar av Escherichia coli (ETEC) vars värmekänsliga toxin (LT) delvis liknar koleratoxinet både strukturellt, funktionellt och immunologiskt[34]. Vaccinet består förutom rCTB av tre olika stammar inaktiverade Vibrio Cholerae bakterier, vilka produceras vid SBL-vaccin AB, där även slutformulering av vaccinet sker. Tillverkningsprocessen av Monovalent bulk rCTB-213 sker genom mikrobiell fermentering av en genetiskt modifierad produktionsstam av Vibrio Cholerae, där huvudodlingssteget sker i 500 liters skala där hela tillvekningsprocessen sker under Good Manifacturing Practise (GMP) förhållanden för att garantera en säker, effektiv och kvalitetsmässigt bra produkt. Målet med detta examensarbete är att upprätta en processbeskrivning för tillverkningsprocessen av Monovalent bulk rCTB-213. Beskrivningen skall baseras på den process som görs idag och innefatta respektive processtegs mål, teori och kritiska parametrar. Den kunskap som skapas genom att definiera och kartlägga (dvs. dokumentera arbetsflödet) i en process har ett stort värde i sig, den är dessutom en utomordentlig plattform för förbättringsarbete genom att den skapar en gemensam bild av vad som sker i processen i dag. I detta examensarbete sker även en sammanställning av produktionen av Monovalent bulk rCTB-213 för perioden februari 2004 - juni 2005. Fakta om hur processen tidigare har betett sig måste användas som bas för förbättringsarbete[1]. För att se om eventuell förekomst av variation för enskilda variabler kan urskiljas, utvärderas processdata för variabler som dokumenterats av företaget för batcher tillverkade under perioden februrari 2004 tom. juni 2005. Under fermentationssteget regleras parametrarna temperatur, pH och andelen löst syre i huvudfermentorn för att upprätthålla optimal fysisk miljö för tillväxt och rCTB produktion. För att få en uppfattning om hur dessa parameterar förhållit sig vid odlingar som utförts under perioden februari 2004 – juni 2005 utvärderas dessa variabler via duglighetsanalys/processkapabilitetsstudie (Cpk). I denna studie beräknas de korrigerade duglighetsindexen för de ovan nämda parametrarna, där den naturliga spridningen för processen sätts i förhållande till vilka gränser som är angivna i registreringsdokument (Process Manifacturing Description) för att få en uppfattning om det som är angivet i registrerings- dokument efterlevs.
14

Striden mot genusborgen : En karaktärsanalys om reproduktion/ ifrågasättande av genussystemet i två kapitelböcker för unga / The battle against the gender castle : a character analysis of the reproduction or questioning of the gender system in two chapter books for children

Nilsson, Lina January 2019 (has links)
Syftet med studien är att, utifrån ett genusteoretiskt perspektiv, beskriva hur genussystemet upprätthålls eller ifrågasätts i böckerna Nidstången och Rum 213, vilka är de verk barn i årskurs 4-6 läser frekvent i sin fria läsning. Detta mot bakgrunden att skolans värdegrundsuppdrag är att arbeta för jämställdhet mellan könen och att elevers identitetsskapande påverkas av den skönlitteratur de läser. Syftet besvaras genom att söka svar på frågorna: vilka egenskaper tillskrivs karaktärerna baserat på deras tankar, känslor och handlingar? Hur framställs de relationer som finns i böckerna? Genom en karaktärsanalys som kombinerar ett mimetiskt och ett semiotiskt perspektiv, visar analysen av resultatet att samtliga karaktärer reproducerar genussystemets premisser, om än på olika sätt och i olika utsträckning.
15

Inferential Model Predictive Control Of Poly(ethylene Terephthalate) Degradation During Extrusion

Ozbek, Murat Olus 01 September 2003 (has links) (PDF)
Poly(ethylene terephthalate), PET, which is commonly used as a packaging material, is not degradable in nature. As an issue of sustainable development it must be recycled and converted into other products. During this process, extrusion is an important unit operation. In extrusion process, if the operating conditions are not controlled, PET can go under degradation, which results in the loss of some mechanical properties. In order to overcome the degradation of recycled PET (RPET), this study aims the control of the extrusion process. Dynamic models of the system for control purposes are obtained by experimental studies. In the experimental studies, screw speed, feed rate and barrel temperatures are taken as process variables in the ranges of 50 &ndash / 500 rpm, 3.85 &ndash / 8.16 g/min and 270 &ndash / 310 oC respectively. Singular value decomposition (SVD) technique is used for the best pairing between the manipulated &ndash / controlled variables, where screw speed is taken as the manipulated variable and molecular weight of the product is taken as the controlled variable. PID and model predictive controller (MPC) are designed utilizing the dynamic models in the feedback inferential control algorithm. In the simulation studies, the performance of the designed inferential control system, where molecular weight (Mv) of the product is estimated from the measured intrinsic viscosity ([&amp / #951 / ]) of the product, is investigated. The controller utilizing PID and MPC control algorithms are found to be robust and satisfactory in tracking the given set points and eliminating the effects of the disturbances.
16

Direct Georeferencing And Orthorectification Of Airborne Digital Images

Kiraci, Ali Coskun 01 September 2008 (has links) (PDF)
GPS/INS (Global Positioning System / Inertial Navigation System) brings possibility of relaxing the demand for aerial triangulation in stereo model construction and rectification. In this thesis a differential rectification algorithm is programmed with Matlab software for aerial frame camera images. This program is tested using exterior orientation parameters obtained by GPS/INS and images are ortho-rectified. Ground Control Points (GCP) are measured in the orthorectified images and compared with other rectification methods according to RMSE and mean error. Besides, direct georeferencing accuracy is investigated by using GPS/INS data. Therefore, stereo models and ortho-images are constructed by using exterior orientation parameters obtained with both aerial triangulation and GPS/INS integration. GCPs are measured in both stereo models and ortho-images, compared with respect to their RMSE and mean error. In order to determine Digital Elevation Model (DEM) effect in ortho-rectification, different DEM data are used and the results are compared.
17

A Framework For Ranking And Categorizing Medical Documents

Al Zamil, Mohammed Gh. I. 01 June 2010 (has links) (PDF)
In this dissertation, we present a framework to enhance the retrieval, ranking, and categorization of text documents in medical domain. The contributions of this study are the introduction of a similarity model to retrieve and rank medical textdocuments and the introduction of rule-based categorization method based on lexical syntactic patterns features. We formulate the similarity model by combining three features to model the relationship among document and construct a document network. We aim to rank retrieved documents according to their topics / making highly relevant document on the top of the hit-list. We have applied this model on OHSUMED collection (TREC-9) in order to demonstrate the performance effectiveness in terms of topical ranking, recall, and precision metrics. In addition, we introduce ROLEX-SP (Rules Of LEXical Syntactic Patterns) / a method for the automatic induction of rule-based text-classifiers relies on lexical syntactic patterns as a set of features to categorize text-documents. The proposed method is dedicated to solve the problem of multi-class classification and feature imbalance problems in domain specific text documents. Furthermore, our proposed method is able to categorize documents according to a predefined set of characteristics such as: user-specific, domain-specific, and query-based categorization which facilitates browsing documents in search-engines and increase users ability to choose among relevant documents. To demonstrate the applicability of ROLEX-SP, we have performed experiments on OHSUMED (categorization collection). The results indicate that ROLEX-SP outperforms state-of-the-art methods in categorizing short-text medical documents.
18

Unterstützung der ukrainischen Genehmigungs- und Aufsichtsbehörde bei der Einrichtung einer verbesserten betrieblichen Überwachung für das KKW Rovno (5. Realisierungsstufe)

Carl, Helmar, Beyer, Matthias, Kriks, Jakob 31 March 2010 (has links) (PDF)
In Analogie zum Pilotprojekt für den 5. Block vom KKW Saporoshje - WWER-1000/W-320 - wurde für die beiden WWER-440/W-213 Blöcke vom KKW Rovno eine verbesserte betriebliche Überwachung eingerichtet. Dazu werden dem Vor-Ort-Inspektor am KKW Standort und der Aufsichtsbehörde in Kiew einmal pro Minute 55 aktuelle sicherheitsrelevante Parameter pro Block und 7 standortspezifische Parameter zur Erfassung und Bewertung mittels moderner technischer Mittel on-line zur Verfügung gestellt. Die zur Ausstattung des Arbeitsplatzes des Vor-Ort-Inspektors unbedingt benötigten Ausrüstungen wurden unter Berücksichtigung der aktuellen Anforderungen des KKW Rovno spezifiziert, beschafft und der ukrainischen Seite unentgeltlich überlassen. Bei Funktionstests Ende 1998/Anfang 1999 wurden Datensätze aus dem lokalen Rechnernetz des KKW Rovno fehlerfrei nach Kiew übertragen und auf einem Rechner im Informations- und Krisenzentrum in Form von Tabellen, Grafiken und Schemata dargestellt.
19

An Mpeg-7 Video Database System For Content-based Management And Retrieval

Celik, Cigdem 01 October 2005 (has links) (PDF)
A video data model that allows efficient and effective representation and querying of spatio-temporal properties of objects has been previously developed. The data model is focused on the semantic content of video streams. Objects, events, activities performed by objects are the main interests of the model. The model supports fuzzy spatial queries including querying spatial relationships between objects and querying the trajectories of objects. In this thesis, this work is used as a basis for the development of an XML-based video database system. This system is aimed to be compliant with the MPEG-7 Multimedia Description Schemes in order to obey a universal standard. The system is implemented using a native XML database management system. Query entrance facilities are enhanced via integrating an NLP interface.
20

Medidas de seções de choque de reações induzidas por nêutrons rápidos

Suita, Julio Cezar, Instituto de Engenharia Nuclear 01 1900 (has links)
Submitted by Marcele Costal de Castro (costalcastro@gmail.com) on 2017-09-27T17:33:25Z No. of bitstreams: 1 JULIO CESAR SUITA D.pdf: 3971978 bytes, checksum: 60e4fc95f134a5c7fee28b0a90ec6b74 (MD5) / Made available in DSpace on 2017-09-27T17:33:25Z (GMT). No. of bitstreams: 1 JULIO CESAR SUITA D.pdf: 3971978 bytes, checksum: 60e4fc95f134a5c7fee28b0a90ec6b74 (MD5) Previous issue date: 1994-01 / Foram feitas medidas de seções de choque das reações 58Ni(n,p) 58Co, 59Co(n,p) 59Fe, 51 V(n,α) 49Sc e 59Co(n,2n) 59Co, e de razões isoméricas do 59Co na faixa de energia de nêutrons entre 9 e 14 MeV. São apresentados os arranjos experimentais desenvolvidos para a realização dessas medidas e o processo de obtenção e análise dos dados. Os resultados obtidos são comparados com medidas anteriores e com a curva teórica calculada com o auxilio do código GNASH, apontado como o mais adequado para a região de energia e massa estudadas. Em geral os resultados experimentais são mais baixos que os calculados. / Cross sections for the 58Ni(n,p) 58Co, 59Co(n,p) 59Fe, 51 V(n,α) 48Sc e 59Co(n,2n) 58Co reactions, and isomeric ratio in 58Co were measured in the neutron energy range from 9 to 14 MeV. The experimental arrangements set up for these measurements are presented together with the data aquisition and analysis procedures. The results are compared with earlier measurements as well as the theoretical calculations performed by the GNASH code, which is known as the most suitable for this energy and mass regions. In general, the experimental results are lower than the theoretical ones.

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