Dissertations / Theses on the topic '2- dimensional electron system (2 DES)'
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Göres, Jörn. "Correlation effects in 2-dimensional electron systems composite fermions and electron liquid crystals /." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11612017.
Full textGeisler, Martin C. "The Hofstadter butterfly and quantum interferences in modulated 2-dimensional electron systems." [S.l. : s.n.], 2005. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-26027.
Full textNübler, Johannes [Verfasser], and David [Akademischer Betreuer] Wharam. "Density Dependence of the v=5/2 Fractional Quantum Hall Effect - Compressibility of a Two-dimensional Electron System under Microwave Irradiation / Johannes Nübler ; Betreuer: David Wharam." Tübingen : Universitätsbibliothek Tübingen, 2011. http://d-nb.info/1162699248/34.
Full textRosner, Helge. "Electronic structure and exchange integrals of low-dimensional cuprates." [S.l. : s.n.], 1999. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB9470690.
Full textMagyar, Peter. "Quelques aspects du transport électronique bidimensionnel : études théoriques en champ magnétique faible et fort." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10025.
Full textCarter, Paul James Anthony. "Acoustic phonon scattering by a 2 dimensional electron gas." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329844.
Full textFord, E. M. "Single electron conduction in 2-dimensional arrays of gold nanodots." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599113.
Full textLee, Sungkoo. "A constraint-based 2-dimensional object display system." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055342896.
Full textMcEnaney, Kevin Bernard. "Magneto-absorption of surface acoustic waves by a 2-dimensional electron gas." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293651.
Full textMartin, Theodore Peyton. "Low-dimensional electron transport in mesoscopic semiconductor devices /." view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1280149921&sid=2&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Full textTypescript. Includes vita and abstract. Includes bibliographical references (leaves 187-196). Also available for download via the World Wide Web; free to University of Oregon users.
Scheid, Matthias. "Tailoring semiconductor spintronics devices : tools for the creation and control of spins in two-dimensional electron gases." Regensburg Univ.-Verl. Regensburg, 2010. http://epub.uni-regensburg.de/14048/.
Full textSalameh, Belal. "Electron spin resonance investigations of organic spin chains and two-dimensional organic conductors." [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11947828.
Full textAmriou, Samia. "Synthesis and electrochemical properties of new l,3-dithiol-2-ylidene derivatives." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/4007/.
Full textZakaria, Marwan F. "An automated vision system using a fast 2-dimensional moment invariants algorithm /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66244.
Full textDigby, Julian Edward. "Phonon absorption by a 2-dimensional carrier system in the quantised Hall regime." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363907.
Full textOng, Seow Meng. "A Mission Planning Expert System with Three-Dimensional Path Optimization for the NPS Model 2 Autonomous Underwater Vehicle." Thesis, Monterey, California. Naval Postgraduate School, 1990. http://hdl.handle.net/10945/23457.
Full textUnmanned vehicle technology has matured significantly over the last two decades. This is evidenced by its widespread use in industrial and military applications ranging from deep-ocean exploration to anti-submarine warefare. Indeed, the feasiblity of short-range, special-purpose vehicles (whether aunonomous or remotely operated) is no longer in question. The research efforts have now begun to shift their focus on development of reliable, longer-range, high-endurance and fully autonomous systems. One of the major underlying technologies required to realize this goal is Artificial Intelligence (AI). The latter offers great potential to endow vehicles with the intelligence needed for full autonomy and extended range capability; this involves the increased application of AI technologies to support mission planning and execution, navigation and contingency planning. This thesis addresses two issues associated with the above goal for Autonomous Underwater Vehicles (AUV's). Firstly, a new approach is proposed for path planning in underwater environments that is capable of dealing with uncharted obstacles and which requires significantly less planning time and computer memory. Secondly, it explores the use of expert system technology in the planning of AUV missions.
Huang, Ran. "Thermodynamics and Ideal Glass Transition on the Surface of a Monatomic System Modeled as Quasi "2-Dimensional" Recursive Lattices." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1342379960.
Full textMoji, Kabelo McDonald. "Comparison of measured photon and electron beam dose distributions between 3D water phanton and profiler 2 scanning system, South Africa." Thesis, University of Limpopo (Medunsa Campus), 2013. http://hdl.handle.net/10386/1086.
Full textBackground and Objectives: To establish whether the profiler 2 scanning system can be used as a substitute for the 3D-water phantom, by comparing the percentage depth doses and beam profiles for both the photons and electron beams, and validating the results using CMS XiO treatment planning system. Methods: Beam data (profiles, percentage depth doses and absolute dosimetry) were acquired for the two systems: (3D-water phantom and profiler 2 scanning system) for beam energies 6 MV and 15 MV photon beams, and 4, 6, 8, 10, 12 and 15 MeV electron beams generated by the Elekta Synergy linear accelerator (linac) for the field sizes of 6 × 6 cm2, 10 × 10 cm2, 14 × 14 cm2, 20 × 20 cm2, and 25 × 25 cm2 at depths of 0.5 cm, 1.0 cm, 2.0 cm, and 5.0 cm respectively. These measurements were acquired using ionization chambers in water and diode detectors in Perspex. The acquired data was sent to CMS XiO treatment planning system for validation. Results: In general, the dose distributions for both systems compared very well with uncertainties within recommended limits. The largest maximum difference in symmetry was 1.6 % for a 6 MV photon beam defined at 25 × 25 cm2 field size. The largest maximum difference in flatness was 2.77 % for a 4 MeV electron beam defined at 10 × 10 cm2 applicator size. The penumbra largest maximum difference was 1.708 cm for 8 MeV electron beam defined at 25 × 25 cm2 applicator size, which was outside the recommended limit of 1.2 cm. The largest maximum difference in field size was 2.388 cm for a 6 MeV electron beam defined at 20 × 20 cm2 applicator size, which was outside the recommended limit of 0.4 cm. The largest maximum difference in percentage depth dose at 10 cm depth was 1.69 % for the 6 MV photon beam. The absolute dose output measurements showed a very good agreement between the two systems to a maximum percentage difference and highest standard deviation of -0.99 % and 0.69 % respectively for the 6 MV photon beam. Validation measurements showed an agreement to less than 1 % and 2 mm for percentage depth doses and beam profiles respectively. Conclusion and recommendation: From the results obtained, it is evident that the profiler 2 scanning system can be used as a substitute for the 3D-water phantom beam data acquisitions during linear accelerator commissioning. The future work based on this study could be to study the limitations involved with the profiler 2 scanning system when used during measurements for commissioning of a linear accelerator. Limitations like field size (maximum field size of 20 × 30 cm2 at SSD = 100 cm), number of Perspex slabs to be used on top of the profiler 2 scanning system and diagonal profile measurements.
PETIT, PIERRE. "Magnetisme et proprietes de conduction des derives cristallins et liquides cristallins de la bisphtalocyanine de lutecium : effet de dimensionnalite." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13163.
Full textLee, Paul Chong Chan. "A QUALITATIVE AND QUANTITATIVE ANALYSIS OF SOFT TISSUE CHANGE EVALUATION BY ORTHODONTISTS IN CLASS II NON EXTRACTION ORTHODONTIC TREATMENT USING THE 3dMD SYSTEM." Master's thesis, Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/217032.
Full textM.S.
With the advent of cephalometrics in the 1930s, numerous studies have focused on the profile of a face to achieve a more esthetic orthodontic treatment outcome. With such heavy emphasis on facial esthetics, a shift in focus from the profile view to the oblique view has become necessary as the smile in the oblique view is what the general public evaluates. The purpose of this pilot study was to determine whether the current tools for diagnosis and treatment evaluation are sufficient. Currently, 2-dimensional composite photographs are utilized in evaluating the soft tissue. At Temple University, 3-dimensional images, which show all sides of the patient's face, are used adjunctively to 2-dimensional composite photographs. In this study, faculty members at the Temple University Department of Orthodontics were asked to complete surveys after viewing two different image modalities, 2-dimensional images and a 3-dimensional video of the same patient. They were asked to fill out the soft tissue goals for specific facial landmarks. Patient photos were in the smiling view as current literature lacks studies on this view. Faculty members' responses from analyzing the 2-dimensional images and 3-dimensional video for each patient were compared to determine which areas had frequent discrepancies from using two different image modalities. During the survey, a voice recorder captured any comments regarding the images. The ultimate goal of this qualitative pilot study was to identify when 3-dimensional imaging is necessary in treatment planning and evaluation, with an added hope to further advance research in 3-dimensional imaging and its vast possibilities to advance the field of orthodontics. Based on the data collected, the following conclusions were made: 1. The qualitative data highlighted that 3-dimensional imaging would be necessary in cases with skeletal deformities. 2. In the oblique view, 3-dimensional imaging is superior than 2-dimensional imaging by showing more accurate shadow, contour, and depth of the soft tissue. 3. Further improvement is necessary to create a virtual patient with treatment simulation abilities. 4. The comfort level among orthodontists of 2-dimensional imaging was higher than 3-dimensional imaging. With more widespread use of 3-dimensional imaging, more orthodontists may gradually reach a higher comfort level in using this relatively new technology. 5. Faculty members expressed high willingness to use 3-dimensional imaging if improvement in new technology could allow for more manipulation and accurate soft tissue prediction. 6. 3-dimensional imaging is superior in its efficiency, quick capture time, and lack of need for multiple images. Implementation of 3-dimensional imaging could streamline the records process and help with practice efficiency without compromising the image quality. 7. Both patients and orthodontists may benefit from using 3-dimensional imaging. Patients can see an accurate representation of themselves and possibly view their own treatment simulation upon further improvement in current technology. Orthodontists would benefit with much more accurate images that may serve as the virtual patient. 8. Besides the exorbitantly high cost, faculty members thought that more advances were needed and the current benefit was not great enough to justify the investment. The results were consistent with other studies that used the oblique view in that the 2-dimensional oblique view lacks depth and does not provide adequate information. With further improvement in current 3-dimensional imaging, this technology can benefit orthodontists in visualizing their patients. In addition, patients can benefit by hopefully seeing a live and accurate simulation of themselves instantly as a virtual patient. With these benefits of 3-dimensional imaging, it may one day be the new standard in patient records in the field of orthodontics.
Temple University--Theses
Wang, Yin-Yu. "Réseaux supraconducteurs : température critique et états mixtes." Grenoble 1, 1987. http://www.theses.fr/1987GRE10060.
Full textNegri, Carlotta. "Controlling electron transport : quantum pumping and single-electron tunneling oscillations." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14670/document.
Full textExploiting time-dependent effects to induce and control currents through mesoscopic and nano\-scopic conductors is a major challenge in the field of quantum transport. In this dissertation we consider two nanoscale systems in which a current can be induced through intriguing mechanisms of coupling between excitations by external fields and electron transport.We first study a quantum pumping problem, analyzing the possibility to induce a DC response to an AC parametric driving through a three-site system in a ring configuration. We are interested in particular in the crossover between adiabatic and antiadiabatic driving regimes and in the presence of dissipation, which is accounted for by coupling with an external bath. We show that for a clever choice of this coupling the dissipative model admits a full analytical solution for the steady state current valid at arbitrary frequency, which allows us to fully understand the pumping-frequency dependence of the induced current. We then focus on a different current-controlling scheme exploiting the phenomenon of single-electron tunneling oscillations (SETOs). In this case, opposite to what happens for pumping, an AC effect, an almost periodic current of single electrons, arises through a tunnel junction circuit as a consequence of a DC bias. We study the zero-temperature noise spectrum of a tunnel junction in different resistive environments with the aim to determine the boundaries of the SETOs regime and quantify their quality in terms of periodicity. We then discuss the finite-temperature generalization and the possibility to account for the effects of quantum fluctuations
Blauch, David N. Anson Fred C. Anson Fred C. "Part I. Improvements in the rotation-rate step experiment for the evaluation of diffusion coefficients at rotating disk electrodes. : Part II. Ion-pairing and electric field effects on electron hopping in the Nafion-tris(2,2'-bipyridine)osmium(3+/2+) system /." Diss., Pasadena, Calif. : California Institute of Technology, 1991. http://resolver.caltech.edu/CaltechETD:etd-06152007-081035.
Full textAhmadouche, Ahmed Abdelkader. "Modélisation électrique des interconnexions multiniveaux en présence de diélectriques stratifiés." Grenoble INPG, 1987. http://www.theses.fr/1987INPG0140.
Full textLe, Touze Christophe. "Etude des propriétés associées aux ondes de densité de charge dans les bronzes oxygénés quasi-bidimensionnels (PO2)4(WO3)2m." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10183.
Full textUtard, Christian. "Les oscillateurs microondes faible bruit de fond a base de mesfet gaas, tegfet gaalas et transistor bipolaire silicium : modelisation, caracterisation et comparaison." Toulouse 3, 1988. http://www.theses.fr/1988TOU30078.
Full textLovisa, Stephane. "Propriétés optiques de puits quantiques de CdTe contenant un gaz d'électrons bidimensionnel." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10099.
Full textDulieu, Olivier. "Etude des systemes atomiques a deux electrons externes par la methode de fonction d'onde correlee de pluvinage : application a l'etude des ions alcalins negatifs." Paris 6, 1987. http://www.theses.fr/1987PA066350.
Full textDriss, Khodja Kouider. "Etude expérimentale et modélisation de la fonction diélectrique des milieux inhomogènes 2D et 3D." Rouen, 1989. http://www.theses.fr/1989ROUES018.
Full textPesquet-Popescu, Béatrice. "Modélisation bidimensionnelle de processus non stationnaires et application à l'étude du fond sous-marin." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0021.
Full textPignol, Valérie. "Évolution et caractérisation de structures cellulaires bidimensionnelles expérimentales, en particulier les mousses de savon, et simulées." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 1996. http://tel.archives-ouvertes.fr/tel-00717860.
Full textChickering, William Elbridge. "Thermopower in Two-Dimensional Electron Systems." Thesis, 2016. https://thesis.library.caltech.edu/9320/2/thesis.pdf.
Full textThe subject of this thesis is the measurement and interpretation of thermopower in high-mobility two-dimensional electron systems (2DESs). These 2DESs are realized within state-of-the-art GaAs/AlGaAs heterostructures that are cooled to temperatures as low as T = 20 mK. Much of this work takes place within strong magnetic fields where the single-particle density of states quantizes into discrete Landau levels (LLs), a regime best known for the quantum Hall effect (QHE). In addition, we review a novel hot-electron technique for measuring thermopower of 2DESs that dramatically reduces the influence of phonon drag.
Early chapters concentrate on experimental materials and methods. A brief overview of GaAs/AlGaAs heterostructures and device fabrication is followed by details of our cryogenic setup. Next, we provide a primer on thermopower that focuses on 2DESs at low temperatures. We then review our experimental devices, temperature calibration methods, as well as measurement circuits and protocols.
Latter chapters focus on the physics and thermopower results in the QHE regime. After reviewing the basic phenomena associated with the QHE, we discuss thermopower in this regime. Emphasis is given to the relationship between diffusion thermopower and entropy. Experimental results demonstrate this relationship persists well into the fractional quantum Hall (FQH) regime.
Several experimental results are reviewed. Unprecedented observations of the diffusion thermopower of a high-mobility 2DES at temperatures as high as T = 2 K are achieved using our hot-electron technique. The composite fermion (CF) effective mass is extracted from measurements of thermopower at LL filling factor ν = 3/2. The thermopower versus magnetic field in the FQH regime is shown to be qualitatively consistent with a simple entropic model of CFs. The thermopower at ν = 5/2 is shown to be quantitatively consistent with the presence of non-Abelian anyons. An abrupt collapse of thermopower is observed at the onset of the reentrant integer quantum Hall effect (RIQHE). And the thermopower at temperatures just above the RIQHE transition suggests the existence of an unconventional conducting phase.
Lee, Ming-Tang, and 李明堂. "Study of a 2+1 dimensional electron-monopole system via supersymmetry." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/36198875235707486035.
Full textHöpfner, Philipp Alexander. "Two-Dimensional Electron Systems at Surfaces — Spin-Orbit Interaction and Electronic Correlations." Doctoral thesis, 2012. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-78876.
Full textIn der vorliegenden Arbeit werden drei unterschiedliche Beispiele für ein zweidimensionales Elektronensystem (2DES) auf der Oberfläche von Elementhalbleitern behandelt: Pt/Si(111), Au/Ge(111) und Sn/Si(111). Atomare Strukturen und deren spezielle Merkmale wurden mit Rastertunnelmikroskopie (STM) und Elektronenbeugung (LEED) untersucht, wobei ein Schwerpunkt die Abscheidung von Pt auf Si(111) war. Hervorzuheben ist hier die Anordnung von Pt Atomen als Trimere, die das Grundgerüst phasenverschobener Domänen bilden. Interessanterweise sind die Trimere um 30° gegenüber dem Substrat verdreht, was einen unerwarteten Symmetriebruch bedeutet. Daher stellt Pt/Si(111) ein einzigartiges Beispiel einer chiralen Struktur auf Halbleitern dar und könnte außerdem für katalytische Prozesse im atomaren Bereich interessant sein. Die Spin-Bahn Wechselwirkung ist auf Oberflächen, die schwere Elemente enthalten, von großer Bedeutung. Hier kann die Spin-Entartung in den elektronischen Zuständen aufgehoben sein, was als Rashba-Effekt bekannt ist. Rechnungen mittels Dichtefunktionaltheorie (DFT) zeigen, dass eine solche Aufspaltung in der hexagonalen Fermi-Fläche von Au/Ge(111) existiert. Experimentell wurde dies mit dreidimensionaler spin- und winkelaufgelöster Photoelektronenspektroskopie bestätigt. Dabei folgt die planare Spin-Komponente einem kreisförmigen Umlaufsinn, während zudem eine starke Aufrichtung des Spins aus der Ebene hinaus entlang gerader Abschnitte der Fermi-Fläche auftritt. Hierbei wurden zum ersten Mal in einem 2DES zusätzliche Rotationen des planaren Spinanteils in der Oberflächenebene nahe von Hochsymmetrierichtungen nachgewiesen. Dieses komplexe Spin-Muster resultiert aus den kristallinen Anisotropien und kann exzellent modelliert werden, indem das Rashba-Modell um Dresselhaus-artige Spin-Bahn Terme höherer Ordnung erweitert wird. Die alternative Verwendung von Gruppe-IV Adatomen bei einer geringeren Bedeckung ändert die Eigenschaften eines 2DES deutlich. Kennzeichnend sind eine verstärkte Ladungsträger-Lokalisierung und ein von Korrelationen bestimmter Grundzustand. Dabei stellt Sn/Si(111) ein Modell-System dar, das zudem ein spin-frustriertes Dreiecksgitter bildet. In einem solchen fehlt üblicherweise die langreichweitige magnetische Ordnung und der Grundzustand ist entweder ein isolierender spiralförmiger Antiferromagnet (AF) oder eine Spin-Flüssigkeit. Zur Analyse des Wechselspiels von geometrischer Frustration und elektronischen Korrelationen dient die Ein-Teilchen Spektralfunktion als Basisgröße. Dazu wurden die sich ergänzenden Stärken von Bandstruktur-Rechnungen in der lokalen Dichtenäherung (LDA), winkelaufgelöster Photoelektronenspektroskopie und Viel-Teilchen Modellen (hier LDA+DCA) kombiniert. Dabei wurde die Existenz eines Schattenbandes und einer Bandrückfaltung nachgewiesen, wobei letztere einen spiralförmigen AF als Grundzustand ausschließt. Vielmehr sind Hüpfprozesse über den nächsten Nachbarn im Gitter hinaus relevant und die spektralen Merkmale sind, trotz der Spin-Frustration, durch einen langreichweitigen kollinearen AF als Grundzustand erklärbar
Hsieh, Li-Ching, and 謝立青. "2-DIMENSION ELECTRON SYSTEM IN CROSSING STATIC ELECTRIC AND MAGNETIC FIELDS." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/65835364848147057334.
Full textZou, Yue. "Quantum Phases and Phase Transitions in Disordered Low-Dimensional Systems: Thin Film Superconductors, Bilayer Two-Dimensional Electron Systems, and One-Dimensional Optical Lattices." Thesis, 2011. https://thesis.library.caltech.edu/6024/2/thesis_v5.pdf.
Full textGöres, Jörn [Verfasser]. "Correlation effects in 2-dimensional electron systems : composite fermions and electron liquid crystals / vorgelegt von Jörn Göres." 2005. http://d-nb.info/973886056/34.
Full textGeisler, Martin C. [Verfasser]. "The Hofstadter butterfly and quantum interferences in modulated 2-dimensional electron systems / Martin C. Geisler." 2006. http://d-nb.info/980568595/34.
Full textHuang, Chun-Wei, and 黃俊瑋. "Image-Based measuring system and it applications in 2-dimensional localization." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/85454170831358116390.
Full text淡江大學
電機工程學系碩士班
96
Localization is an important topic in Robotics. It is essential to have accurate position information of the robot so that the robot can be moved to any desired location. Although various Many localization methods have been proposed, those methods, however, usually use sensor fusion techniques to calculate the location of the robot. As a result, excessively calculation time might be required. In this thesis, we present a distance measurement method by using a single CCD camera and two parallel laser projectors beside the camera to measure the distance between the CCD camera and a target object. The proposed measuring system can measure the distance between arbitrarily points on an oblique surface and the angle between the oblique surface and the horizon. We also apply the proposed image-based measurement system to determine the position of the robot in 2-dimensional plane. Furthermore, this thesis also establishes a parameter identification system to make the proposed measuring system suitable for all kinds of CCD cameras. Thus, measurement accuracy of the proposed system can be significantly improved. Finally, practical experiments are conducted in the thesis to validate the effectiveness and viability of the proposed method. Simulation results also demonstrate the measurement system has a satisfactory accuracy in 2-dimensional localization.
Tchaplyguine, Igor [Verfasser]. "Electronic structure of strongly correlated low-dimensional spin 1/2 systems : cuprates and vanadates / von Igor Tchaplyguine." 2002. http://d-nb.info/967614309/34.
Full textYan, Jaw-Jenq, and 顏召政. "The Study of 2 Dimensional Vision Servo Tracking System on Robot Positioning." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/83184499690617632419.
Full text華梵大學
機電工程研究所
93
Robots are now in widespread use on automatic engineering﹐which has the advantage of high speed﹐high accuracy﹐and stably performance﹒It doesn’t have the disadvantage of human easy feel boring on repeating works﹒On traditionally robot use the method of teaching or teaching box guiding the route and recording in memory﹐then repeat again﹒Otherwise it can control the robot with programming the moving procedure﹒So it always plans the moving route beforehand﹒ Robot control system needs a on-time tracking ability for tracking moving object﹒Machine vision bases on image processing﹐it can recognize the grabbing image information﹐then output the result to control robot﹒Machine vision likes the human see a object then have a reactive﹐it is a method of realizing control robot on time﹒This dissertation uses machine vision﹐and set the CCD on robot arm﹐grabbing and analyzing the image information﹒So it can flexible change the route doesn’t plan the way previously﹐and achieve the goal of tracking on time﹒
Chen, A., Soo-Jin Chua, Clifton G. Jr Fonstad, B. Wang, and O. Wilhelmi. "Two-dimensional Photonic Crystals Fabricated by Nanoimprint Lithography." 2004. http://hdl.handle.net/1721.1/7374.
Full textSingapore-MIT Alliance (SMA)
Wu, Chun-Te, and 吳俊德. "The Characteristic study of 2-D electron gas induced in AlN/GaN heterojunction using Helicon Sputtering system." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/77945262056671636616.
Full text中原大學
電子工程研究所
92
AlGaN/GaN heterostructure field-effect transistors (HFETs) have been a subject of intensive investigation recently and have emerged as attractive candidates for high voltage, high-power operation at microwave frequencies such as low noise microwave amplifier, power microwave amplifier, high temperature devices and power suppliers. However, there exist some problems. One of those is large lattice mismatch as increasing the Al content, which increases the defects of interface and decreases the sheet carrier concentration as well as the carrier mobility. Therefore some research groups suggested to use the AlN/GaN heterostructure. AlN/GaN heterostructure would have much higher sheet carrier concentration, if the difficulties of deposition can be overcome. The aims of this study are to deposit epitaxial AlN films on GaN/Sapphire substrates at low growth temperature, and investigate the presence of large polarization field in the AlN barrier layer which results in high values of the 2DEG sheet density. Epitaxial AlN films have been successfully deposited on GaN/Sapphire substrates at low-temperature (300℃) using Helicon sputtering system. The FWHM of XRD rocking curve for (002) peak of AlN film is 0.125 and the �� scan confirms the epitaxial orientation relationship between the three layers of AlN/GaN/Sapphire. The two dimensional electron gas induced by AlN/GaN heterojunction has been measured to achieve -1.24×1013cm-2. The fruitful results will have contributions for fabricating high-power devices based on AlN/GaN heterojunction.
Liu, Weihao, and 劉韋豪. "Detection of the Pathological Changes of Superficial Tissues and Development of a 2-Dimensional Image Measurement System Based on Bioimpedance Technique." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/65041250604292427448.
Full text國立暨南國際大學
生物醫學科技研究所
99
In Taiwan, 35.9 out of 100,000 people diagnosed with oral cancer, just second to New Guinea and Solomon. According to the statistics reported by the Department of Health, oral and skin cancer ranked sixth and twenty-first positions respectively in major cause of cancer death for four consecutive years in Taiwan. Currently non-invasive oral and skin cancer diagnostic products are very scarce, and the equipment is very expensive and heavy. Therefore, the purpose of this study is to develop a 2-dimensional image measurement system based on bioimpedance technique. The system has been evaluated with the averaged percentage error of about 5.2% ± 2.8%. Finally, we can use this system to distinguish normal and morbid tissues by the 2-dimensional image.
Huang, Yu Shiang, and 黃鈺翔. "Establish a beam characteristic analysis system for the Chang Gung Memorial Hospital (CGMH) proton pencil beam scanning technique using a 2-dimensional ionization chamber array." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/76823621396314962858.
Full text長庚大學
醫學影像暨放射科學系
103
Quality assurance is an important procedure in radiation therapy. The purpose of this investigation was to establish a beam characteristic analysis system for Chang Gung Memorial Hospital (CGMH) proton pencil beam scanning technique using a 2-dimensional ionization chamber array and to evaluate the effect of clinical instruments set up error affecting the analyzed results. The following beam properties of the proton pencil beam scanning technique were analyzed: beam position, beam size, beam intensity, scanning velocity of beams, and beam energy. The detector distribution of 2D-arrays and a pre-designed scanning pattern were simulated using in-house program. Because 2D ion-chamber arrays challenge with coarse resolution, we applied mathematical methods such as 2D Gaussian fitting function to post-processing the signals. To compare the signals in ideal spatial resolution and discrete distribution, the differences were analyzed quantitatively. The differences for position and spot size analysis were within 0.3 mm and 0.6 mm, respectively , but intensity difference is larger than 10% at small spot situation. However, energy verification behaved good agreement in R80 value. The analysis results from the 2D ion-chamber arrays detected signals by pre-designed scanning pattern can be used to confirm the beam properties. The most obviously difference between the 2D arrays and high resolution dosimeters was their ability to test intensity stability for small spot size. And we suggested that the clinical set up error could not exceed 1˚ rotation and 1 mm position shift.
Yuan, Judy Chia-Chun. "Defining a natural tooth color space based on a three-dimensional shade system." 2007. http://proquest.umi.com/pqdweb?did=1320964491&sid=20&Fmt=2&clientId=39334&RQT=309&VName=PQD.
Full textTitle from PDF title page (viewed on Nov. 28, 2007) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Brewer, Jane D. Includes bibliographical references.
Blauch, David N. "Part I. Improvements in the rotation-rate step experiment for the evaluation of diffusion coefficients at rotating disk electrodes. Part II. Ion-pairing and electric field effects on electron hopping in the Nafion-tris(2,2'-bipyridine)osmium(3+/2+) system." Thesis, 1991. https://thesis.library.caltech.edu/2613/1/Blauch_dn_1991.pdf.
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