Tesi sul tema "Speculaur reflection"
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Purcell, Isabella Pauline. "Specular reflection from interfaces". Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386624.
Testo completoSferrazza, Michele. "The study of polymer interfaces by specular and off-specular neutron reflection". Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624963.
Testo completoTing, Choon Boon. "Universal Zero Specular Reflection Curves for MetaMaterials". Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17469.
Testo completoMaterials are generally classified in terms of their constitutive parameters, the complex permittivity and permeability , in the frequency domain. These parameters are used to determine the response of materials to electromagnetic (EM) radiation. Materials found in nature have positive real parts for both and . In recent years, researchers have shown that a new class of materials called metamaterials (MTMs), characterized by inclusions of various shapes and materials that are small compared to wavelength, result in an effectively homogeneous medium with the unique properties of negative real and which cause EM waves traveling through the medium to exhibit unusual characteristics. Zero specular reflection layers for four material types such as double positive (DPS), double negative (DNG), epsilon-negative (ENG) and mu-negative (MNG) materials are examined in this thesis. For each defined type of MTM, the transcendental equations are derived and solved numerically to generate curves for zero specular reflection. A MATLAB program was developed to generate universal curves for DPS, DNG, ENG, and MNG materials. The results were discussed and evaluated to determine wave behavior in each type of MTM as well as how they can be used as a matched-surface radar-absorbing material (RAM) for military application. The results were compared to published data.
Brelstaff, Gavin J. "Inferring surface shape from specular reflections". Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/15347.
Testo completoDia, Amadou Sall. "Quantitative ultrasound imaging of human cortical bone". Electronic Thesis or Diss., Sorbonne université, 2024. https://theses.hal.science/tel-04650855.
Testo completoOsteoporosis is a disease characterized by a decrease in bone mass and an increase in porosity, weakening the bones and potentially leading to fragility fractures. Globally, one-third of women over the age of 50 and one-fifth of men aged over 50 will experience osteoporosis-related fractures, contributing to over 8.9 million fractures annually worldwide. Early detection and treatment can prevent these fractures. Several techniques have been developed to assess bone quality, with ultrasound emerging as a cost-effective, portable, and safe option. Ultrasound imaging of the cortex of long bones allows for the evaluation of bone quality by estimating cortical thickness and ultrasonic wave-speed, which are biomarkers of mechanical strength and fracture risk. However, challenges arise with increased cortical porosity in osteoporotic bone, making it difficult to detect the inner surface (endosteum) and limiting image quality. The aim of this study is to design an image reconstruction technique to enhance ultrasound images of cortical bone. This involves understanding the factors influencing image quality. Synthetic and experimental ultrasound datasets were generated to achieve this. The results demonstrate successful estimation of cortical thickness and ultrasonic wave-speed using ultrasound imaging for homogeneous cortical bone. In vivo estimation of wave-speed at the tibial cortex of healthy individuals achieved a precision of less than 3%. However, for degraded bones, increased cortical porosity and vascular pore size create speckle that obscures the visibility of the endosteal interface. A novel refraction-corrected specular beamforming algorithm was proposed to improve the visibility of the endosteal interface. Application of this algorithm to both ex vivo and in vivo datasets revealed enhanced visibility compared to traditional Delay-and-Sum (DAS) beamforming. This study provides a better understanding of factors affecting bone ultrasound image contrast and proposes considering scatterers as specular reflectors to enhance endosteal interface visibility. By evaluating the specularity of the endosteal interface, it becomes possible to potentially assess the roughness of the endosteum. This opens a way for designing new bone mechanical quality quantifiers. Bone ultrasound imaging shows promise in identifying and monitoring individuals with low cortical bone mechanical quality at risk of osteoporotic fracture
Willatt, A. J. "Specular reflection of neutrons and X-rays from interfaces". Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235074.
Testo completoLiu, Miaomiao, e 刘苗苗. "Pose estimation from reflections for specular surface recovery". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47246376.
Testo completopublished_or_final_version
Computer Science
Doctoral
Doctor of Philosophy
Rhodes, Trevor Ian. "Neutron reflection used to investigate polymers and surfactants at the solid-liquid interface". Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275249.
Testo completoIsmail, Mostafa R. "The role of specular and diffuse reflections in urban noise propagation". Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400183.
Testo completoGanapathiraman, Subburengan. "QUANTIFICATION OF SURFACE DEFECTS USING PRIMARY HIGHLIGHT IN DIFFUSE ANGLE GRAY SCALE IMAGES". UKnowledge, 2005. http://uknowledge.uky.edu/gradschool_theses/348.
Testo completoSmitthakorn, Pattra. "Effects of temporal distribution of specular and diffuse reflections on perceived music quality". [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0016560.
Testo completoKempic, Joy III. "Objective Image Quality of CRT Displays under Ambient Glare: Assessing the ISO 9241-7 Ergonomic Technical Standard". Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36622.
Testo completoMaster of Science
Rapp, Holger H. [Verfasser], e C. [Akademischer Betreuer] Stiller. "Reconstruction of Specular Reflective Surfaces using Auto-Calibrating Deflectometry / Holger H. Rapp. Betreuer: C. Stiller". Karlsruhe : KIT-Bibliothek, 2012. http://d-nb.info/1027141730/34.
Testo completoHodaň, Tomáš. "Detekce a odstranění odlesků ze sekvence snímků". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236351.
Testo completoKoch, Rainer [Verfasser], Andreas [Gutachter] Nüchter, Stefan [Gutachter] May e Sergio [Gutachter] Montenegro. "Sensor Fusion for Precise Mapping of Transparent and Specular Reflective Objects / Rainer Koch ; Gutachter: Andreas Nüchter, Stefan May, Sergio Montenegro". Würzburg : Universität Würzburg, 2018. http://d-nb.info/1163201758/34.
Testo completoContino, Alessandro Patrizio. "Solar mirrors characterization for concentrating solar power technology". Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/993.
Testo completoTan, He Ping. "Transfert couple rayonnement-conduction instationnaire dans les milieux semi-transparents à frontières opaques ou naturelles soumis à des conditions de température et de flux". Poitiers, 1988. http://www.theses.fr/1988POIT2264.
Testo completoBorne, Bruno Silva. "Espaços especulares : articulações entre o real e o virtual". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/106948.
Testo completoSpecular Spaces: articulations between the real and the virtual is a study in visual arts. The main theme from which the work is based is creating relationships between real spaces and virtual spaces. Two creative concepts underlie the artistic process: the use of specular reflections and the site-specific. These concepts will be addressed in two different ways: the use of mirrors in the visual arts will be based on the notion of Mirror as a Device, whereas the site-specific is related to the concept of Aesthetics of Opacity, bound to film theory. The object of study is comprised of nineteen artworks created in the period of 2008 to 2013. They are artworks produced by hybrid techniques that utilizes procedures of architecture, computer graphics and visual arts. As a research methodology, the processes and creative concepts will be analyzed related to theoretical and practical examples.
Maftei, Radu. "Analyse stochastique pour la simulation de particules lagrangiennes : application aux collisions de particules colloïdes". Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4130/document.
Testo completoThis thesis broadly concerns colloidal particle simulation which plays an important role in understanding two-phase flows. More specifically, we track the particles inside a turbulent flow and model their dynamics as a stochastic process, their interactions as perfectly elastic collisions where the influence of the flow is modelled by a drift on the velocity term. By coupling each particle and considering their relative position and velocity, the perfectly elastic collision becomes a specular reflection condition. We put forward a time discretisation scheme for the resulting Lagrange system with specular boundary conditions and prove that the convergence rate of the weak error decreases at most linearly in the time discretisation step. The evidence is based on regularity results of the Feynman-Kac PDE and requires some regularity on the drift. We numerically experiment a series of conjectures, amongst which the weak error linearly decreasing for drifts that do not comply with the theorem conditions. We test the weak error convergence rate for a Richardson Romberg extrapolation. We finally deal with Lagrangian/Brownian approximations by considering a Lagrangian system where the velocity component behaves as a fast process. We control the weak error between the position of the Lagrangian system and an appropriately chosen uniformly elliptic diffusion process and subsequently prove a similar control by introducing a specular reflecting boundary on the Lagrangian and an appropriate reflection on the elliptic diffusion
Mikulik, Petr. "Réflectivité des rayons X par des multicouches planaires et structurées". Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10056.
Testo completoFerté, Morgan. "Étude et analyse de couches minces par techniques multi-spectroscopiques pour une application sur une ligne de galvanisation". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0206/document.
Testo completoWith the emergence of new steel loaded in reactive elements, the characterization of the physico-chemical properties of the surface states has taken a new dimension. Indeed, the thin films of oxide formed are damaging for the surface quality of the steel and may adversely affect the application of varied coatings. Also, to ensure a good quality on finished products, the need to characterize, online, the steel surface over its entire width is increasingly necessary. The hyperspectral imaging is an emerging technology that allows both spatial and spectral characterization of a surface. It had never been used to characterize thin layers in the steel industry. During my PhD, both methodologies have been developed to meet this need: one via a measurement in specular reflection and the other via a measurement in emission. In addition to a synthesis of reference samples, a full experimental development ranging from a simulation bench to the data processing was performed. This work has demonstrated the capability of the hyperspectral imaging to detect thin surface oxide layers on a steel surface, sometimes at several hundred degrees Celsius. These encouraging results led to the first industrial implementation of this technology. This thesis made it possible to study theoretically and experimentally the phenomena involved and to move from the concept that meets an industrial need to the implementation of an online sensor dedicated to the characterization of a thin oxide layer on a moving surface in industrial conditions
Yang, Shang-Hua, e 楊尚樺. "Specular Reflection Removal based on Logical Estimation". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/13978061765971102959.
Testo completo國立臺灣大學
資訊網路與多媒體研究所
101
In this thesis, we proposed a specular reflection removal method based on logical estimation to deal with two specular images with the same scene but with different specular regions. Assume the two input images contain some complementary information. They can reference each other to recover the specular region. Even if there is a specular region appearing in both images, our method still can remove specularity and recover the structure in the image. At first, we use Scale-Invariant Feature Transform to describe the features of two input images and employ information to warp one of two input images to another one. According to the matching relationship of the feature points, we generate a specular-overlap image and a specular-union image. Then, we use these two images to fit a logical estimation model and find the specular region in both specular-overlap image and specular-union image. Finally, we recover the specular region of specular-overlap image by applying color transformation and color blending. Our results show that the proposed method has removed the specular reflection and recover the structure of contents in the specular region automatically.
Lin, Yi-lung, e 林義隆. "Innovative Back Light Unit Design via Specular Reflection". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/px3mgg.
Testo completo國立臺灣科技大學
電子工程系
94
Display is among the most important in the nowadays significant opto-electric industry. Because the liquid crystal is not self-illuminated, it needs an outer light source to operate. Therefore, BLU is the most important part in LCD display and it had been developed several type of BLU carter to demand for market. BLU (Back Light Unit) plays an important role in display. Most of edge lighting BLUs use dot patterns or similar ways to gain uniformity via scattering. In this article, we use mirrors to achieve uniformity. Mirrors reduce the energy loss of source and easier to analyze. In this article, we employ the CCFL for light source of edge lighting BLU, and we use the specular reflection instead of dot patterns for uniformity. This method reduces the energy loss and is easier to analyze. Although parameters (relative position,θ…) adjusting is necessary, the proposed system is suitable for any reflector. As long as the reflected rays are concurrent, the proposal design is independent of reflectors shape and will achieve more uniformity and reduce energy loss.
Lee, Hsuan-Han, e 李宣翰. "Coin Authentication Based on Intensity Variation of Specular Reflection". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/91328833645016667882.
Testo completo國立交通大學
多媒體工程研究所
103
Nowadays counterfeit money has increased to an unacceptable level in Taiwan, especially for fifty dollar coins. As the techniques of counterfeit become more advanced, many traders cannot effectively distinguish the money between authentic or counterfeit. In order to prevent the counterfeit money from running rampant, we propose an image analysis method based on the change of specular reflection of a coin. It is verified through experiments that the proposed approach, and the implement prototype machine, can effectively and efficiently distinguish authentic and counterfeit coins. We hope the proposed approach can prevent effectively suppress the amount of counterfeit money in our society.
Bo-WeiHuang e 黃博偉. "Application of Fringe Reflection Method for Specular Surface Profile Measurement". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/j6z34m.
Testo completo國立成功大學
機械工程學系
107
The main purpose of this study is to measure the specular profile using two different fringe reflection methods as well as exploring the differences between the two methods. The two methods performed in this experiment include the vector method and the normal vector method. They are used to measure the wafer and the male die as well as the female die, respectively. Finally, the results of these experiments are then compared using the surface roughness meter and displacement sensor. The root-mean-square error (henceforth, RMSE) of the wafer with 30 μm of range of height is found to be within 1.69 μm. The RMSE of the male die and female die with 18 mm of range of height is found to be within 0.22 mm. In the experiment, it is observed that the larger the pitch of fringe, the more visible the wave profile of the specimen. In order to avoid the slope of the specimen being too large, which may ultimately cause the camera to not be able to clearly observe the image on the screen from the specimen. The specimen must be properly tilted. When integrating the x-direction of the slope of a female die, the female die geometry relationship will cause integrations that occur only in horizontal directions to commit integral errors. It should be priorly determined whether or not the geometry of the specimen will cause the slope in the central axis of the integral or the area near it to be absent. If the slope is indeed absent, the area where the slope exists should be integrated first, followed by integrating the area where the slope does not exist. It is also necessary to find the adjacent slope point in the direction of such integration then search for the integration result of the surrounding from the slope point. Continue the integration until all the slope points have completed their respective integration.
Lian, Zih-Hao, e 連子豪. "Minimizing specular reflections of the iris image acquisition system". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/8g5dxp.
Testo completo國立交通大學
顯示科技研究所
102
Specular reflection is an important issue for an iris acquisition imaging system. This thesis is aimed to investigate the influence of near IR source on the image quality as well as optimizing arrangement of light source to enhance segmentation process. The arrangement of the light source manipulates the specular positions on iris region. More specifically, by controlling the geometric relations of subject, light source and image acquisition is able to avoid the specular reflections overlapping with iris information region. In this thesis, we proposed a complete geometric model to predict the specular reflections. The effectiveness and practicability of the proposed modeling have been validated by a series of experimental testing.
LAI, JHIH-REN, e 賴致仁. "Temporal and Spatial Analysis Based Specular Reflection Removal Techniques for Endoscopy". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/45374311315000254821.
Testo completo國立雲林科技大學
電機工程系
104
Specular reflection in endoscopy is annoying to physicians when performing Minimally Invasive Surgery (MIS). A spatial domain inpainting techniques was proposed last year for reflection removal in laparoscopy, in this thesis, our goal is to extend the spatial domain technique to the use of temporal domain information based on the observation that the locations of specular reflections are varying when the camera is moving, thus, reflections in current frame may be normal (non-reflection) in previous frames. Therefore, the idea is to search through the original previous 2Nth frames (N=1:10) for the key frame which has maximum non-reflection (normal) pixels in the current reflection areas, then match current frame to the key frame using registration technique, the reflection areas in current frame are compensated by coping from the reflection removed (compensated ) key frame. Since the illuminations in the reflection area in current frame and key frame may be different, we developed a illumination compensation technique to compensate the illumination difference. All pixels in the reflection area in the first frame as well as the pixels in the current frame but not overlapped by the key frame are marked and compensated using spatial domain inpainting technique proposed last year.
YOU, YUAN-WEI, e 游原瑋. "Machine vision based highly specular reflection curved surface defects inspection system". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7h8xwv.
Testo completo國立臺北科技大學
機械工程系機電整合碩士班
106
Since the surface of the cylinder (golf club) has up to 14 kinds of defects with different type of sizes, directions, and locations, this paper designs two kinds of lighting systems for defect detection on the surface of the club through the three-dimensional rendering software simulation lighting systems structure. However, the surface of golf club was electroplated with high specular reflection characteristics. Therefore, the design of lighting system was required to avoid the external lighting system affecting the image quality of the club in this paper. The first lighting system developed a light-shielding element with an one-side slit observation hole above the circular tube. Moreover, the light-shielding element could pre-vent the light from being highly reflective coverage of the club and generate the dark area to defect inspection. The second lighting system had used a linear diffused to detect inspection in the radial depth of the club surface. The experimental results show that both lighting sys-tems can be applied to high-mirror and high reflection surface objects for defect detection. The first light source system has a defect accuracy of 71.9%, and the second light source system has a defect accuracy of 82.5%.
Hung, Cheng-Wei, e 洪晟瑋. "Identification of Coin Authenticity Based on Relative Positions of Specular Reflections". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/2a4ffc.
Testo completo國立交通大學
多媒體工程研究所
105
With the increased on counterfeit money of market, especially for fifty dollar coin. Many people cannot effectively distinguish the money between real or counterfeit, which forced the unscrupulous vendor who manufacture counterfeit money has run rampant. In order to prevent the counterfeit money from increasing, we are engaged in research for this area. We propose an image processing method that based on intensity change of a coin. The proposed approach and the corresponding machine can effectively and efficiently distinguish coin. We hope the proposed approach can prevent the counterfeit money in our life.
Tang, Chang-Yu, e 唐昌宇. "A Path Reuse Method for Specular Surface Reflection in Monte Carlo Path Tracing". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/74055458258527275294.
Testo completo國立臺灣師範大學
資訊工程學系
104
Physically based image synthesis aims to render realistic images. It is widely used in many industries, e.g., Computer-generated imagery (CGI) in the movie industry, 3D models preview in the architecture and the design industry, and of course, 3D scenes in the computer gaming industry. In the real world, the information of light is infinite; therefore, we must do sampling to estimate it. How to deal with the global illumination effect plays an important role in whether the rendered image looks real or not. There are many sampling methods that reveal different features of the scene. Bidirectional path tracing, which is one of the Monte Carlo path tracing methods, is known for its quick convergence; however, due to innate limitation, it cannot handle some difficult cases, such as specular-diffuse-specular (SDS) paths. In this thesis, we introduce an alternative path reuse method while facing the SDS problem during the operation.
LO, MING-MIN, e 羅明旻. "Specular Reflection Removal And Reconstruction For Endoscopic Video Based On Background Sprite Model". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/zqk76y.
Testo completo國立中正大學
電機工程研究所
106
Endoscopes are used for a wide range of purposes. The endoscope is mainly composed of a light source and a lens. Endoscopes are often used for examinations inside the body, such as the large intestine, stomach, etc. In addition to in vivo examination of the human body, minimally invasive surgery is also an endoscope-related application. Compared with the traditional surgery, minimally invasive surgery has the advantages of small wound and quick recovery. Minimally invasive surgery is performed through an endoscope. The light source and lens of the endoscope can be used to display the current situation from a monitor. The physician can treat or observe through the endoscope. Since the surface of the internal organs is full of water, when the endoscope is used, the light source will have water reflection when it hits the surface of the organ. We call it Specular reflection. This Specular reflection will affect the doctor's diagnosis. This can cause shadowing to the organs. But most of the current literature focuses on the use of Inpainting. The method is to use the surrounding information to fill the Specular reflection. The result of this method is not the actual situation on the surface of the organ, and it is difficult for the doctor to believe. This paper uses a background Sprite model to reconstruct the Specular reflection. First, the Specular reflection will be detected and marked first. Next, we will calculate the Global motion estimation(GME) parameter. Integrate the endoscope image into the background Sprite model and form a progressive background Sprite model. Finally, get information from the momentary background Sprite model and reconstruct the Specular reflection. The experiment result shows, this paper can effectively reconstruct the specular reflection and reconstructive result is actually the surface of the organ. However, the specular reflection of the endoscope image is not homogeneous, the effect of reconstruction can be strengthened.
Koch, Rainer. "Sensor Fusion for Precise Mapping of Transparent and Specular Reflective Objects". Doctoral thesis, 2018. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-163462.
Testo completoFast schon wöchentlich füllen Meldungen über Erdbeben, Wirbelstürme, Tsunamis oder Wald-brände die Nachrichten. Es ist hart anzusehen, aber noch viel härter trifft es die Rettungskräfte, welche dort zum Einsatz gerufen werden. Diese müssen gut trainiert sein, um sich schnell einen Überblick verschaffen zu können und um den zerstörten Bereich nach Opfern zu durchsuchen. Zeit ist hier ein seltenes Gut, denn die Überlebenschancen sinken, je länger es dauert bis Hilfe eintrifft. Für eine effektive Teamkoordination werden alle Informationen in der Einsatzzentrale gesammelt. In Trupps wird nach Opfern gesucht. Hierfür werden die zerstörten Gebäude durchsucht und alle Hohlräume inspiziert. Dabei können die Helfer oft nicht darauf vertrauen, dass die Gebäude stabil sind und nicht noch vollständig kollabieren. Hier sind Rettungsroboter eine willkommene Hilfe. Sie sind ersetzbar und können für gefährliche Aufgaben verwendet werden. Dies macht die Arbeit der Rettungstrupps sicherer. Allerdings gibt es solche Roboter noch nicht von der Stange. Sie müssten gewisse Anforderungen erfüllen, dass sie in einem solchen Szenarien einsetztbar sind. Neben Ansprüchen an die Mechanik, müsste eine 3D-Karte des Einsatzgebietes erstellen werden. Diese ist Grundlage für eine erfolgreiche Navigation (durch unebenes Terrain), sowie zur Beeinflussung der Umgebung (z.B. Tür öffnen). Die Umgebungserfassung wird über Sen-soren am Roboter durchgeführt. Heutzutage werden bevorzugt Laserscanner dafür verwendet, da sie präzise Messdaten liefern und über einen großen Messbereich verfügen. Unglücklicherweise werden Messdaten durch transparente (z.B. Glas, transparenter Kunststoff) und reflektierende Objekte (z.B. Spiegel, glänzendes Metall) verfälscht. Eine Vorbehandlung der Umgebung (z.B. abdecken der Flächen), um diese Einflüsse zu verhindern, ist verständlicherweise nicht möglich. Zusätzliche Sensoren zu verwenden birgt ebenfalls Nachteile. Das Problem dieser Objekte liegt darin, dass sie nur teilweise sichtbar sind. Dies ist abhängig vom Einfallwinkel des Laserstrahls auf die Oberfläche und vom Typ des Objektes. Dementsprechend könnnen die Messwerte bei transparenten Flächen von der Oberfläche oder vom Objekten dahinter resultieren. Im Gegensatz dazu können die Messwerte bei reflektierenden Oberflächen von der Oberfläche selbst oder von einem gespiegelten Objekt resultieren. Gespiegelte Objekte werden dabei hinter der reflektierenden Objerfläche dargestellt, was falsch ist. Um eine präzise Kartierung zu erlangen, müssen die Oberflächen zuverlässig eingetragen werden. Andernfalls würde der Roboter in diese navigieren und kollidieren. Weiterhin sollten Punkte hinter der Oberfläche abhängig von der Oberfläche behandelt werden. Bei einer trans- parenten Oberfläche müssen die Punkte in die Karte eingetragen werden, weil sie ein reelles Objekt darstellen. Im Gegensatz dazu, müssen bei einer reflektierenden Oberfläche die Messdaten dahinter gelöscht werden. Dafür ist eine Unterscheidung der Objekte zwingend. Diese Anforderungen erfüllen die momentan verfügbaren Algorithmen jedoch nicht. Aus diesem Grund befasst sich folgende Doktorarbeit mit der Problematik der Erkennung und Identifizierung transparenter und spiegelnder Objekte, sowie deren Einflüsse. Um dem Leser einen Einstieg zu geben, beschreiben die ersten Kapitel: den theoretischen Hindergrund bezüglich des Verhaltens von Licht; Sensorsysteme für die Distanzmessung; Kartierungsalgorithmen, welche in dieser Arbeit verwendet wurden; und den Stand der Technik bezüglich der Erkennung von transparenten und spiegelndend Objekten. Danach wird der Reflection-Identification-Algorithmus, welcher Basis dieser Arbeit ist, präsentiert. Hier wird eine 2D und eine 3D Implementierung beschrieben. Beide sind als ROS-Knoten verfügbar. Das anschließende Kapitel diskutiert Experimente, welche die Anwendbarkeit und Zuverlässigkeit des Algorithmus verifizieren. Für den 2D-Fall ist ein Vor- und ein Nachfilter-Modul notwendig. Nur mittels der Nachfilterung ist eine Klassifizierung der Objekte möglich. Im Gegensatz kann im 3D-Fall die Klassifizierung bereits mit der Vorfilterung erlangt werden. Dies beruht auf der höheren Anzahl an Messdaten. Weiterhin zeigt dieses Kapitel beispielhaft eine Adaptierung des TSD-SLAM Algorithmus, so dass der Roboter auf einer aktualisierten Karte navigieren kann. Dies erspart die Erstellung von zwei unabhängigen Karten und eine anschließende Fusionierung. Im letzten Kapitel werden die Ergebnisse der Arbeit zusammengefasst und ein Ausblick mit Anregungen zur Weiterarbeit gegeben
Michalis, Krista. "Modeling Specular and Diffuse Reflection Sound Fields in Enclosures with an Energy-Intensity Boundary Element Method". Diss., 2011. http://hdl.handle.net/10161/4997.
Testo completoSteady-state sound fields in enclosures, with specular and diffuse reflection boundaries, are modeled with a first-principle energy-intensity boundary element method using uncorrelated broadband directional sources. The specular reflection field is represented by a limited set of spherical harmonics that are orthogonal on the half-space. The amplitudes of these harmonics are determined by a Lagrange multiplier method to satisfy the energy conservation integral constraint. The computational problem is solved using an iterative relaxation method starting from the 3-D diffuse reflection solution. At each iteration, directivity harmonics are estimated by post-processing and the influence matrix is refined accordingly. For internal sources, simple first reflection images improve accuracy with virtually no penalty on computation time. Monotonic convergence occurs in relatively few relaxation steps. Extrapolating to an infinite number of boundary elements and iterations gives very accurate results. The method is very computationally efficient. Results are compared to exact benchmark solutions obtained from a frequency-by-frequency modal analysis, and a broadband image method, demonstrating high accuracy. The method of absorption scaling is verified for complicated 3-D cases, and showing that the spatial variation in rooms is largely determined by source position and the relative distribution of absorption, but not the overall absorption level.
Dissertation
Μπόκαρης, Παναγιώτης-Αλέξανδρος. "Διαχωρισμός συνιστωσών ανάκλασης από ψηφιακή φωτογραφία". Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4276.
Testo completoThe subject of this thesis is the separation of two reflection components (specular and diffuse) on surfaces of dielectric materials. The specular reflections are a significant problem for many algorithms in the field of computer vision, i.e. image segmentation. After the analysis of the problem and an introduction to colorimetry and polarization we describe popular methods that have already been used for this problem. Finally, we represent our own separation method, which exploits the different degree of polarization in the two reflection components and achieves the separation using independent component analysis (ICA). The method is applied on both real and virtual images.
Waddington, Christopher. "Adaptive Fringe Pattern Projection Techniques for Imgae Saturation Avoidance in 3D Surface Measurement". Thesis, 2010. http://hdl.handle.net/10012/5616.
Testo completoChen, Pei-yu, e 陳培瑜. "The experimental study on the perception of different users at the interior design space in relation to color scheme and specular reflection- based on the interior space without funiture and the residential interior space". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/w5c6t4.
Testo completo國立臺灣科技大學
建築系
100
Color and specular reflection are the important in interior design and also have different meaning and value in our life. Color and specular reflection influent the atmosphere of interior space and bring the effect of human. In this study, the relationship between color, specular reflection, interior space and human perception are discussed. the experiment 1 is about the interior space without funiture and the participants are required to compare 9 rooms (3 different colors: blue, yellow and white;and 3 different specular reflection: 0.1, 0.45, and 0.8). The experiment 2 is about the residential interior space with funiture and the participants are required to compare 16 rooms ( 4 function: living room, bedroom, dining room and study room; in 4 type: blue 0.45, yellow 0.1, white 0.45 and color 0.1). The experiments are proceeded in qestionaires and 3d rendered pictures. The result in experiments figure out the participants in different background such as different gender, ages, eyes color, architecture, interior background and different country have different perception of different spaces. Most paricipants can not accept high specular reflection in the interior space. In the residential interior, most participant have more positve emotion in the yellow type design. The purpose of his research is helping designers to understand the spatial perception and the preference of color and spacular refleciton in interior design of differents users and to expect the designer can create perfected interior space in the future.
Průchová, Kristýna. "Vibrační spektroskopie ve farmaceutické analýze". Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-307055.
Testo completoNazaré, Maria Leonor Leal da. "Devant les miroirs de Pistoletto. Art et vie spéculaires". Master's thesis, 1997. http://hdl.handle.net/10362/20030.
Testo completoL’œuvre de Michelangelo Pistoletto expose l’idée même de miroir, en proposant à la fois des dispositifs miroiriques dans son travail et un méta discours sur l’art en tant que miroir. J'ai cru y trouver l’occasion de me poser des questions sur son œuvre qui peuvent peut-être servir à penser d'autres situations d'art contemporain, ou d'art tout court. Que reflètent les œuvres? Comment le reflètent-elles? En essayant de répondre à ces deux questions, on s'aperçoit vite que la qualité de refléter ou de réfléchir n'en est qu'une, parmi d'autres qualités des miroirs, et des œuvres en tant que miroirs. Il faut alors remplacer ces questions par deux autres: Que font les œuvres quand elles fonctionnent comme des miroirs? Et comment? Ce qu'elles font, outre réfléchir et refléter, outre leur qualité réfléchissante, nous montre leurs autres qualités: mnésiques, symboliques, narratives, géométriques, algébriques, interpellatrices, révélatrices, auto réflexives et méta-discursives. J'aimerais appeler cet ensemble « les qualités miroiriques», pour emprunter un terme à Duchamp , puisqu' elles concernent les qualités du miroir. J'ai cru pouvoir analyser leur fonctionnement dans les œuvres, à l’appui de celles de Pistoletto, et en gardant le souci de les rapporter à un récepteur qui en jouit. Je suis donc allée à la recherche de cette métaphore courante qui prétend que l’art reflète la vie dans la conviction qu'un objet ou une expérience artistiques n'existent pour ce récepteur que quand ils lui renvoient des images et des possibilités de lui-même et de son monde; et ceci dans la conviction que, par exemple, son expérience du double est moins une expérience de reproduction qu'une expérience qui le nourrit de lui-même. Les qualités miroiriques multiples des œuvres équivalent à leur potentiel mobilisateur; elles m'ont amenée à rechercher les formes de vitalité qui se dessinent à l’intérieur de cette mobilisation. Autrement dit, à reprendre le débat, qui semblerait plutôt épuisé, sur les rapports entre l’art et la vie. Mais ce débat n'a pu m'intéresser que dans la mesure où le point de vue des qualités miroiriques déplaçait son paradigme duel: celui sur lequel se profilent des oppositions vicieuses comme subjectif/objectif, expressionnisme / inexpressionnisme, expression / engagement social, contemplation / participation, choses / images, bidimensionnel / tridimensionnel, autonomie / utilité, formaliste / référentiel et d'autres qui leur sont proches. Il n'y a pas d'art ou la vie ne soit pas inscrite; ce qui change sont les points de vue, les lectures et le genre de «vie» recherchée et / ou oblitérée. Comme on le verra, c'est encore l’œuvre de Pistoletto qui m'en a fourni les meilleurs prétextes. Celle-ci inclut des initiatives aussi disparates que des objets, des «actions» ou des textes écrits. Son œuvre écrite est à la fois informative, littéraire, programmatique et plastique, ce qui ne va pas sans poser quelques problèmes dans l’approche interprétative. Les révélations apportées par les miroirs littéraux et métaphoriques concernent aussi, entre autres, les problèmes de l’encadrement, de la peinture, de la représentation, du sujet, de l’auto-reconnaissance et de la participation à l’œuvre.
Rautenbach, Helperus Ritzema. "An empirically derived system for high-speed rendering". Thesis, 2012. http://hdl.handle.net/2263/28196.
Testo completoThesis (PhD)--University of Pretoria, 2012.
Computer Science
unrestricted