Дисертації з теми "Bloch frames"
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1
Monaco, Domenico. "Geometric phases in graphene and topological insulators." Doctoral thesis, SISSA, 2015. http://hdl.handle.net/20.500.11767/4844.
Повний текст джерелаАнотація:
This thesis collects three of the publications that the candidate produced during his Ph.D. studies. They all focus on geometric phases in solid state physics.
We first study topological phases of 2-dimensional periodic quantum systems, in absence of a spectral gap, like e.g. (multilayer) graphene. A topological invariant n_v in Z, baptized eigenspace vorticity, is attached to any intersection of the energy bands, and characterizes the local topology of the eigenprojectors around that intersection. With the help of explicit models, each associated to a value of n_v in Z, we are able to extract the decay at infinity of the single-band Wannier function w in mono- and bilayer graphene, obtaining |w(x)| <= const |x|^{-2} as |x| tends to infinity.
Next, we investigate gapped periodic quantum systems, in presence of time-reversal symmetry. When the time-reversal operator Theta is of bosonic type, i.e. it satisfies Theta^2 = 1, we provide an explicit algorithm to construct a frame of smooth, periodic and time-reversal symmetric (quasi-)Bloch functions, or equivalently a frame of almost-exponentially localized, real-valued (composite) Wannier functions, in dimension d <= 3. In the case instead of a fermionic time-reversal operator, satisfying Theta^2 = -1, we show that the existence of such a Bloch frame is in general topologically obstructed in dimension d=2 and d=3. This obstruction is encoded in Z_2-valued topological invariants, which agree with the ones proposed in the solid state literature by Fu, Kane and Mele.
2
Arslan, Guray. "Strengthening Of Reinforced Concrete Frames By Custom Shaped High Strength Concrete Masonry Blocks." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610335/index.pdf.
Повний текст джерелаАнотація:
Located on one of the highly active seismic fault systems in the world, the building stock in Turkey is mainly composed of reinforced concrete frames with 4-5 stories. Due to design and construction deficiencies resulting from the use of unqualified personnel and insufficient supervision, many of these buildings lack lateral stiffness, ductility and strength. For many structures, there is a need to alleviate these deficiencies by means of some rehabilitation techniques prior to earthquakes. One approach also used very widely in Turkey is to fill some of the frame bays by cast-in-place R/C panels. The procedure appears to be very practical at first glance. It also appears to be very economical as far as the production of the panels is concerned. However, the production phase is slow, dirty, destructive and disruptive to occupants. Moreover, it requires relatively skilled personnel and special equipment. Therefore, the real life experience shows that the actual cost in practice is much higher when all other hidden costs are taken into account.
The aim of this experimental study is to explore the potential of using infill walls made of custom shaped and high strength concrete blocks as a simpler and more practical alternative to cast-in-place R/C panels to increase the lateral load bearing capacity of frame structures. The effectiveness of FRCM (Fiber Reinforced Cementitous Matrix) system on damaged structures is also investigated in this study.
3
Habib, Brian. "Framnäs förskola." Thesis, KTH, Arkitektur, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188999.
Повний текст джерелаАнотація:
Det hela började med en väldigt grundläggande tanke om en säker förskola. Trappor är farliga och bör undvikas. För många våningar blir lätt problematiskt. Avgörande för projektet blev det att barnen ska kunna spendera hela dagar på ett och samma våningsplan. Därmed är barnens avdelningar helt placerade på sina respektive envåningsplaner. De omsluter gemensamt samlingsrum och gård. På övre plan finns de yngsta barnens avdelning med direkt tillgång till takterrass. Planlösningen följer en upprepande modulenhet, där rummen är glasade mot söder. På så sätt efterliknas den enkelhet som finns i modernistiska paviljonger, samtidigt som en tydlig framsida definieras. En förlängning av rummen bildar en passage som går genom hela byggnaden, både interiört och exteriört och på bågge våningsplan. Detta skapar ett "mellanrum" i ett försök att överbrygga den annars skarpa gränsen mellan inne och ute. Jag tror att denna utformning med upprepande rumsindelning, samt lätthet och horisontalitet i arkitektoniskt uttryck talar ett språk som klargör för hur förskolan ska brukas.It all started with a very essential idea for a safe kindergarten. Staircases are dangerous and are better avoided. Too many levels easily become problematic. Crucial through the project was that the children could spend full days on a single storey plan. Consequently the childrens' sections are fully placed on their respective single level plans. These enclose a common room and playgrounds. On the upper level you will find the youngests' section directly accessing roof terraces. The floor plan follows a repetitive module, where rooms facing south are glazed in that direction, resembling the simplicity of modernist pavilions, yet defining a pronounced front. An extension of the rooms towards the playgrounds, a passageway, runs through the whole building, both indoors and outdoors and on both levels, creating a linking "room" in the middle. I believe that this type of layout with repetitive modules and simplicity and horizontality in architectural expression makes it clear how the kindergarten is best operated.
4
Ellenberger, Lindsey Renee. "Transfer of Function in a Block Design Context across Frames of Distinction, Comparison, and Opposition." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2342.
Повний текст джерелаАнотація:
Individuals with autism are largely taught using direct contingency learning, limiting their already potentially limited relational repertoire. A multiple baseline design across skills with an embedded multiple probe design was implemented to demonstrate the efficacy of training procedures used to established nonarbitrary relations in the context of block design. The PEAK – Transformation module (PEAK-T) is a curriculum designed to develop the relational repertoire of individuals with and without developmental disabilities, from which procedures were adapted. Training phases were each preceded by test probes of each of the target relations. Transfers of stimulus function were tested by presenting a novel context in which the trained and derived relations were used in completion of a task. The entailment probes across each of the programs showed transfers of function across three relational stimulus classes. All three directly trained relations across three frames resulted in mastery level responding. The results support the efficacy of the PEAK-T curriculum such that complex relational responding can be taught to a child with intellectual disabilities.
5
Milburn, Paul Spencer. "Multi-variable block transforms for motion compensated digital video compression." Thesis, University of Salford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261859.
Повний текст джерела
6
Chang, Andy. "Fast multi-frame and multi-block selection for H.264 video coding standard /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20CHANG.
Повний текст джерелаАнотація:
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 57-58). Also available in electronic version. Access restricted to campus users.
7
Cai, Guangcheng Chen Liming. "Le suivi de l'objet mobile et l'algorithme du bloc estimé." [S.l.] : [s.n.], 2005. http://bibli.ec-lyon.fr/exl-doc/gcai.pdf.
Повний текст джерела
8
Hanks, Kevin N. "Rotational Strength and Stiffness of Shallowly Embedded Base Connections in Steel Moment Frames." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6261.
Повний текст джерелаАнотація:
Shallowly embedded column base connections with unreinforced block out concrete are a common method of connecting steel columns to their foundation. There has been little research done to accurately quantify the effects of this block out concrete on the connection strength and rigidity, and therefore there is nothing to aid the practicing engineer in accounting for this in structural analysis. Due to this lack of understanding, engineers have typically ignored the effects of shallow block out concrete in their analysis, presumably leading to a conservative design. Recent research has attempted to fill this gap in understanding. Several methods have been proposed that seek to quantify the effects of shallow block out concrete on a column base connection. Barnwell proposed a model that predicts the strength of a connection. Both Jones and Tryon used numerical modeling to predict the rotational stiffness of the connection. An experimental study was carried out to investigate the validity of these proposed models. A total of 8 test specimens were created at 2/3 scale with varying column sizes, connection details, and embedment depths. The columns were loaded laterally and cyclically at increasing displacements until the connection failed. The results show that the strength model proposed by Barnwell is reasonable and appropriate, and when applied to this series of physical tests produce predictions that have an observed/predicted ratio of between 0.95 to 1.39. The results also show that methods for estimating the rotational stiffness of the connection at the top of the block out concrete, as proposed by Jones and Tryon also produce reasonable values that had observed/predicted ratios of between 0.93 to 1.47. An alternative model for determining a design value for the rotational stiffness of a shallowly embedded column base plate is also proposed. When the embedment depth to column depth ratio is greater than 1.22, the connection is sufficiently rigid and at small deflections (less than 1% story drift) may be accurately modelled with infinite rotational stiffness (a "fixed" connection) at the base of the column.
9
Cai, Guangcheng. "Le suivi de l'objet mobile et l'algorithme du bloc estimé." Ecully, Ecole centrale de Lyon, 2005. http://bibli.ec-lyon.fr/exl-doc/gcai.pdf.
Повний текст джерелаАнотація:
Dans cet article nous proposons une méthode qui permet d'identifier et de suivre l'objet cible à partir des données digitales MPEG. Cette méthode consiste à récupérer les informations sur le vecteur de mouvement de chaque macrobloc en mouvement puis identifier les objets mobiles avec la méthode de la croissance régionale des vecteurs de mouvement. Cette méthode évite les problèmes liés à la forme, à la couleur et à la taille de l'objet. Notre technique utilise la transformation de Hough rapide et les caractéristiques géométriques de la zone de texte pour extraire les informations de la publicité des images de programme sportif sur TV. La corrélation de Speckle Digital qu'on utilise dans la mesure optique est la technique d'adaptation bloc du traitement d'image. Nous pouvons déduire la valeur de déplacement de subpixel avec la formule d'interpolation et comparer la précision théorique et la stabilité de la méthode d'interpolation parabolique et la méthode de gradientMoving object detection and tracking is a major issue in many vision systems. Since features of MPEG, our paper presents a novel mehtod that directly detects and tracks the moving object in video from MPEG coded data fluid. Our method can fully make use of the temporal and spatial correlation between I and P frame, and effectively avoid the difficult of change of shape, color and background of moving object. Precise visibility measuring of billboard advertising is a key element for the organizers and broadcasters to make cost effective their sport live relay. Our technique makes use of fast Hough transform and text's geometry features in order to extract advertisement from sport TV images. Digital Speckle Correlation Method has been applied to an optical measurement. This paper discusses the theory precision of the quadratic interpolation and the gradient method from mathematics theory. And we ameliorate their formula from discrete integer aspect
10
Urger, Mucip Ahmet. "Apartment Block As The Object Of The Generic City:ankara." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605548/index.pdf.
Повний текст джерелаАнотація:
Ankara has experienced a radical transformation after 1950s, in which the identity of the highly planned capital has been erased, emphasizing homogenization, blankness and similarity. The Apartment Block was the object of this condition and the subject of the transformation in the urban identity, both with its physical existence and with the mind-set it has radiated to the whole levels of the society. It has stripped out the identity of the city with its "endless reproduction."
This transformation has led the Apartment Block to be accused of transforming Turkish cities to deformed agglomerations, deprived of aesthetics. In this sense, architectural discipline has been criticized for its impotence to respond the economical, social and cultural conditions that traverse the urban setting. This criticism has questioned the generative role of architecture in the Early Republican period as a social engineering and discouraged any relation between architecture and the city, which has manifested the reduction of the architecture to a formal discipline. Ankara, with its dazzling transformation within few decades proposed its own urbanism and its own architecture, with the mutation of the Apartment Block first to a resilient frame than to a multi-programmed infrastructure. This study will consider this transformation as &
#8216
another&
#8217
manifestation of a new kind of urbanism that was mainly declared by Rem Koolhaas and OMA, claming that the resilient and neutral objects are the dominant and extensive forms of the contemporary urbanism. Hence, the study presents a cross reading of the urban development of Ankara together with Rem Koolhaas&
#8217
book Delirious New York and his essay The Generic City in SMLXL. The utmost goal is to explore a possible "
reciprocal relation"
between architecture and the city and to explore the limits of architectural intervention in the particular case of Ankara. Such an objective inevitably requires extending the limits of architectural thinking to the city scale. Thus, Ankara goes beyond a case study in an inquiry that aims to undertand the mechanisms of the building production in the contemporary urbanism.
11
Burmeister, Steffi [Verfasser], Jürgen [Akademischer Betreuer] Oberst, Jürgen [Gutachter] Oberst, and Jürgen [Gutachter] Kusche. "Determining rotational elements of planetary bodies : method and implementation of an inertial frame bundle block adjustment / Steffi Burmeister ; Gutachter: Jürgen Oberst, Jürgen Kusche ; Betreuer: Jürgen Oberst." Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156271487/34.
Повний текст джерела
12
Bína, Vojtěch. "Hotel Artia." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-239948.
Повний текст джерелаАнотація:
The final thesis „Hotel Artia” is processed in the form design documentation for building construction. The building of hotel is located on plot no. 443/1 in Červená Řečice. The building has four-storey part of hotel and single-storey part of restaurant. Structural system is RC frame. The building has warm flat roof and contact thermal insulation.
13
DHAKAL, PAWAN. "Algorithms for 5G physical layer." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2670627.
Повний текст джерелаАнотація:
There is a great activity in the research community towards the investigations of the various aspects of 5G at different protocol layers and parts of the network. Among all, physical
layer design plays a very important role to satisfy high demands in terms of data rates, latency, reliability and number of connected devices for 5G deployment. This thesis addresses
he latest developments in the physical layer algorithms regarding the channel coding, signal detection, frame synchronization and multiple access technique in the light of 5G use
cases. These developments are governed by the requirements of the different use case scenarios that are envisioned to be the driving force in 5G.
All chapters from chapter 2 to 5 are developed around the need of physical layer algorithms dedicated to 5G use cases. In brief, this thesis focuses on design, analysis, simulation and
he advancement of physical layer aspects such as 1. Reliability based decoding of short length Linear Block Codes (LBCs) with very good properties in terms of minimum hamming
istance for very small latency requiring applications. In this context, we enlarge the grid of possible candidates by considering, in particular, short length LBCs (especially extended CH codes) with soft-decision decoding; 2. Efficient synchronization of preamble/postamble in a short bursty frame using modified Massey correlator; 3. Detection of Primary User
activity using semiblind spectrum sensing algorithms and analysis of such algorithms under practical imperfections; 4. Design of optimal spreading matrix for a Low Density Spreading (LDS) technique in the context of non-orthogonal multiple access. In such spreading matrix, small number of elements in a spreading sequences are non zero allowing each user to
spread its data over small number of chips (tones), thus simplifying the decoding procedure using Message Passing Algorithm (MPA).
14
Gustavsson, Göran, and Göran Löfgren. "Höga trähus : Befintliga trähusproducenters förutsättningar och intresse att bygga flerfamiljshus med bärande trästomme med fler än två våningar." Thesis, Växjö University, School of Technology and Design, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2312.
Повний текст джерелаАнотація:
Syftet med uppsatsen är att undersöka befintliga trähusproducenters förutsättningar och intresse att bygga flerfamiljshus med bärande trästomme med fler än två våningar. För att nå vårt syfte har vi satt oss in i marknaden för höga trähus. Detta har vi gjort genom att initialt betrakta dels marknaden ur olika intressenters perspektiv, dels genom att undersöka företagen som finns på marknaden idag och placera in deras respektive byggsystem i en produktlivscykel. Vi har därefter satt oss in i marknaden för trähus och fokuserat på tio företag som vi har djupintervjuat. Vi beskriver sedan de samband vi ser mellan förutsättningarna på marknaden för höga trähus och intervjuresultaten. Dessa samband utmynnar i en analys av de faktorer som påverkar företagens val av strategi. Vi gör en uppdelning av företagen i olika strategiska grupper utgående från deras erfarenhet av höga trähus, och vi redogör för hur företagen i de olika grupperna kan agera vid några olika scenarier. Faktorer som påverkar är ägarförhållanden, övrig verksamhet i koncernen och bristen på ingenjörskompetens i projekteringen. I våra redovisade scenarier tror vi att flera av dagens trähusproducenter kommer att finnas på marknaden om fem år. Det gäller främst företag som är starka på projektverksamhet, men också företag som är underleverantörer av element. De företag som nu är på marknaden med ett byggsystem eller som nu är på väg in tror vi, i våra scenarier, har ett gynnsamt läge främst för leveranser till större och medelstora städer.
The purpose of this thesis is to investigate existing manufacturers of wooden framed buildings requirements and interest of building block of flats with bearing wooden frame with more than two floors. With this in view we have studied the market for high wooden houses. We have initially regarded that market from the approach of different interest parties and through investigation of the companies in the market today and to place their systems for building technologies in a life cycle for the product. After that we have regarded the market for wooden framed buildings and focused on the ten companies which we have interviewed. Than we describe how the requirements on the market for high wooden houses are related to results from the interviews. These connections end in an analysis of the factors which influence the choices for the strategy of the companies. We divide the companies in different strategic groups. These groups originate from their experiences of high wooden houses. We describe how the different companies can act at some different scenarios. Factors which influence the existing manufacturers of wooden framed buildings entrance on the market are the state of proprietions, the other activity in the group of companies and the lack of competence of engineering in the projecting. In the scenarios, which we have given details about, do we predict that several of todays existing manufacturers of wooden framed buildings will be on the market in less than five years. This is above all valid for companies which are strong in the activities of projects and companies which are subcontractor of building elements. The companies which are on the market now with a system for building technologies, or are on their way, we believe have a favourable position above all for deliveries to larger or mediumlarge cities.
15
Carda, Vojtěch. "Bytový dům v Třebíči." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265716.
Повний текст джерелаАнотація:
The content of this thesis is to design four storey block of flats. The house is supposed to be passive. The building is four storey basement, roofed hipped roof, with flat roof operation served as a terrace. The building is located on a plot of number 1037/28 in the village Trebic, cadastral area Trebic. Supporting structures of the house are made of monolithic reinforced concrete frame with masonry infill of clay brick blocks THERM. The building is insulated contact insulation system EPS boards. The roofing is done using a timber truss. The house is based on the base plate. The project includes a seminar work assessing thermal technical and acoustic properties of structures.
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Твердохліб, Віталій Вікторович, Виталий Викторович Твердохлеб та Vitaliy Tverdohlib. "Метод підвищення продуктивності телекомунікаційних систем на основі управління інтенсивністю відеотрафіка". Thesis, Національний авіаційний університет, 2021. https://er.nau.edu.ua/handle/NAU/48932.
Повний текст джерелаАнотація:
Дисертаційна робота присвячена вирішенню актуальної науковоприкладної задачі, що полягає у забезпечення якості відеосервісів на необхідному рівні за рахунок зниження часу затримок доставки відеотрафіку у системі надання відеосервісів з використанням безпровідних телекомунікаційних мереж.
Викладаються етапи створення методу управління інтенсивністю відеокадрів на рівні кодування сегментів кадрів та їхніх структурних складників, базові особливості якої полягають у тому, що для кожного
сегменту формується кодовий опис у вигляді сукупності незалежних кодових структур. Це дозволяє здійснювати управління бітовою інтенсивністю відео за рахунок зміни кількості структурних складників кодової конструкції трансформованого сегменту кадру.
Метод дозволяє забезпечити скорочення надмірності опису відеокадру за рахунок урахування структурних особливостей опису трансформант на рівні бітового представлення. Обгрунтовується доцільність підходу, що базується на виключенні ряду трансформант сегменту відеокадру з подальшою інтерполяцією, для побудови методу управління інтенсивністю відеопотоку з контрольованим рівнем якості.
Розробляється метод управілння бітовою інтенсивністю відеотрафіку на базі інтенполяції трансформант, що забезпечує обробку відеопотоку у реальному часі. У рамках методу управління забезпечуються режими
функціонування, у ході яких здійснюється зміна бітової інтенсивності да корегування рівня помилки, внесеної у процесі управління.Диссертация посвящена решению актуальной научно-прикладной задачи, заключающейся в обеспечении качества видеосервисов на необходимом уровне за счет снижения времени задержек доставки видеотрафика в системе предоставления видеосервисов с использованием беспроводных телекоммуникационных сетей. Излагаются этапы создания метода управления интенсивностью видеокадров на уровне кодирования сегментов кадров и их структурных составляющих, базовые особенности которого заключаются в том, что для каждого сегмента формируется кодовый описание в виде совокупности независимых кодовых структур. Подход на основе независимых кодовых структур позволяет осуществлять управление битовой интенсивностью видео за счет изменения количества структурных составляющих кодовой конструкции трансформированного сегмента кадра. Метод позволяет обеспечить сокращение избыточности описания видеокадра за счет учета структурных особенностей описания трансформант на уровне битового представления. Обосновывается целесообразность подхода, основанного на исключении ряда трансформант сегмента видеокадра с последующей интерполяцией для построения метода управления интенсивностью видеопотока с контролируемым уровнем качества. Разрабатывается метод управления битовой интенсивностью видеотрафика на базе интерполяции трансформант, что обеспечивает обработку видеопотока в реальном времени. В рамках метода управления обеспечиваются режимы функционирования, в ходе которых выполняется изменение битовой интенсивности да корректировки уровня ошибки, внесенной в процессе управления.
The dissertation is devoted to the solution of an urgent scientific and applied problem, which consists in ensuring the quality of video services at the required level by reducing the time of video traffic delivery delays in the system for providing video services using wireless telecommunication networks. The stages of creating a method for controlling the intensity of video frames at the level of encoding frame segments and their structural components are described, the basic features of which are that for each segment a code description is formed in the form of a set of independent code structures. This allows you to control the bit intensity of the video by changing the number of structural components of the code structure of the transformed frame segment. The method allows to reduce the redundancy of the video frame description by taking into account the structural features of the description of transformants at the level of bit representation. The expediency of an approach based on the exclusion of a number of transformants of a video frame segment with subsequent interpolation to construct a method for controlling the intensity of a video stream with a controlled level of quality is substantiated. A method for controlling the bit intensity of video traffic is being developed based on downsampling of frame slices at the transformants level with their subsequent interpolation, while processing the video stream in real time is provided. To implement the method for controlling the bit rate of video traffic based on downsampling of slices, sets of basic transformants and transformants are preliminarily formed in their structure, which can be thinned out at this stage. Within the framework of the control method, the existence of modes of operation is provided, during which the bit intensity is changed in real time and the error level is corrected, which can be introduced in the process of controlling the value of the video bit intensity.
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Nemati, Navid. "Theorie macroscopique de propagation du son dans les milieux poreux 'à structure rigide permettant la dispersion spatiale: principe et validation." Phd thesis, Université du Maine, 2012. http://tel.archives-ouvertes.fr/tel-00848603.
Повний текст джерелаАнотація:
Ce travail présente et valide une théorie nonlocale nouvelle et généralisée, de la propagation acoustique dans les milieux poreux à structure rigide, saturés par un fluide viscothermique. Cette théorie linéaire permet de dépasser les limites de la théorie classique basée sur la théorie de l'homogénéisation. Elle prend en compte non seulement les phénomènes de dispersion temporelle, mais aussi ceux de dispersion spatiale. Dans le cadre de la nouvelle approche, une nouvelle procédure d'homogénéisation est proposée, qui permet de trouver les propriétés acoustiques à l'échelle macroscopique, en résolvant deux problèmes d'action-réponse indépendants, posés à l'échelle microscopique de Navier-Stokes-Fourier. Contrairement à la méthode classique d'homogénéisation, aucune contrainte de séparation d'échelle n'est introduite. En l'absence de structure solide, la procédure redonne l'équation de dispersion de Kirchhoff-Langevin, qui décrit la propagation des ondes longitudinales dans les fluides viscothermiques. La nouvelle théorie et procédure d'homogénéisation nonlocale sont validées dans trois cas, portant sur des microgéométries significativement différentes. Dans le cas simple d'un tube circulaire rempli par un fluide viscothermique, on montre que les nombres d'ondes et les impédances prédits par la théorie nonlocale, coïncident avec ceux de la solution exacte de Kirchhoff, connue depuis longtemps. Au contraire, les résultats issus de la théorie locale (celle de Zwikker et Kosten, découlant de la théorie classique d'homogénéisation) ne donnent que le mode le plus attenué, et encore, seulement avec le petit désaccord existant entre la solution simplifiée de Zwikker et Kosten et celle exacte de Kirchhoff. Dans le cas où le milieu poreux est constitué d'un réseau carré de cylindres rigides parallèles, plongés dans le fluide, la propagation étant regardée dans une direction transverse, la vitesse de phase du mode le plus atténué peut être calculée en fonction de la fréquence en suivant les approches locale et nonlocale, résolues au moyen de simulations numériques par la méthode des Eléments Finis. Elle peut être calculée d'autre part par une méthode complètement différente et quasi-exacte, de diffusion multiple prenant en compte les effets viscothermiques. Ce dernier résultat quasi-exact montre un accord remarquable avec celui obtenu par la théorie nonlocale, sans restriction de longueur d'onde. Avec celui de la théorie locale, l'accord ne se produit que tant que la longueur d'onde reste assez grande.
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Zouhar, Martin. "Novostavba administrativní budovy v Blansku." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227269.
Повний текст джерелаАнотація:
The solution of the diploma thesis is the office block in Blansko. Building is suggested for using as insurance company. This building is located in a particular territory which had precisely limited the possibilities of the construction. There are three aboveground floors. The building is designed like reinforced concrete frame with complete masonry type THERM. The building is built on drilled piles that are connected fundamental grate. The facade is made as ceramic aired facade. The building has a flat roof with classical succession layer and is stabilized by gravel. The building is designed for fifty people.
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Giacintová, Sylva. "Intenzivní dům v Brně." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-394011.
Повний текст джерелаАнотація:
The subject of this thesis is the architectural study of revitalization of a city block and its spatial structure. Selected part of city was solved already in previous project that preceded own thesis. Merger proposal will allow a larger number of different functions within the complex, which will ensure the residents to various forms of housing, services and employment and leisure activities. The studied area is located in the city of Brno-Veveří. Plan shape of the object based on the area in which the three parties connected to the access road. Mass and spatial design respects the surrounding buildings and uses the sidewalks along the whole of the area. The matrix of the object is divided by two axes passing through the object into three blocks linked by a courtyard. This creates a square with a water surface with the possibility of recreation and sitting under the trees. The shape of these three blocks is further formed in several height terraced layers. Do terraces are placed in the atrium and individual residential and office units have large windows and balcony available. This solution brings natural light into the interior while allowing illumination of the courtyard and surrounding objects within the chosen area. This spatial structure is horizontally divided by function. There are proposed underground public garage, arcade with shops, services, administration and housing. The exterior of the building is designed by combining brick facades and white plaster, which works like optically lighter impression of the building.
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Melo, Franco Lenon Rogerio de. "A maldição como processo = leituras de Gaspard de la Nuit." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/270320.
Повний текст джерелаАнотація:
Orientador: Suzi Frankl SperberDissertação (mestrado) - Universidade Estadual de Campinas, Instituo de Estudos da Linguagem
Made available in DSpace on 2018-08-15T22:23:26Z (GMT). No. of bitstreams: 1 MeloFranco_LenonRogeriode_M.pdf: 1830662 bytes, checksum: d63fce9d22e9ed1808c6436f83f0a25d (MD5) Previous issue date: 2010
Resumo: A dissertação se ocupa da recepção da obra francesa Gaspard de la Nuit: fantaisies à la manière de Rembrandt et de Callot desde sua publicação nos anos românticos até nossos dias. As leituras de Sainte-Beuve, Baudelaire, Mallarmé e André Breton, sobretudo, são revisadas à luz de exames sincrônicos e diacrônicos. Os diferentes acolhimentos do texto são oportunidade e aporte para discutirmos seus aspectos prevalentes, tais como a relação da poesia com as artes plásticas, a fundação de um novo gênero que é o poema em prosa moderno e a noção de poète maudit. Após o decantamento crítico de numerosos leitores, apresentamos então nossa exegese particular da obra - que se acrescenta a esses registros recepcionais que foram analisados
Abstract: Not informed
Mestrado
Literatura Geral e Comparada
Mestre em Teoria e História Literária
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Bár, Radek. "Autosalon." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226538.
Повний текст джерелаАнотація:
This master thesis is focused on elaboration of project documentation for constructing autosalon in Kopřivnice. Project and appendix are processed by current applicable laws, regulations and standarts. Designed object is situated on plat #419/2 and partly on plat #419/27. Both plats are parts of cadastral area of Kopřivnice. There are all needed engineering networks nearby. Object is divided on three functional parts, which are operationally and constructionally connected. First part is exhibition and representative hall, with capacity of 11 exhibited vehicles. Second part is formed by administrative facilities for staff including sanitary facilities for both staff and visitors. Third part is service for personal and light commercial vehicles with three working stations. Construction is designed partially reinforced concrete columnar structural system and partially of brick longitudinal structural system. The biggest plan dimension of building is 34.3x35.15m. The cladding is designed of sandwich blocks LIVETHERM tl.400mm. Roof of building accross the surface is flat roof with several height levels. Establishment of the object is a combination of footings and foundation belts. Cladding of exhibition hall is more than 50% glazed. Parts of service and autosalon are designed as sigle storey objects, while administrative part is designed as a two.
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Navrátil, Ondřej. "Přístavba polyfunkčních prostor k výrobní hale - stavebně technologický projekt." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240430.
Повний текст джерелаАнотація:
The subject thesis's topic is the technological implementation of rough upper construction's extension of the company BÖHM's polyfunctional space to technological shop floor located in district Červený Kříž in city of Jihlava. This thesis contains (includes) the implementation of the building's framework made up of ferroconcret and steel construction. The thesis namely includes the solution of the construction site equipment, the situation of the construction with the transport routes solution, the technical report, the technology study of the major technology stages, the bill of quantities and the itemized budget, the suggestion of the main lifting device, the evaluation of the main finance funds for building's construction, the technological instruction, the technical report of the construction site equipment, the schedule of work suggestion of the machine system, the control plan and test plan.
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Šámalová, Daniela. "Dům krátké cesty." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-354940.
Повний текст джерелаАнотація:
The assigned territory is situated in the City of Brno, in the city district of Židenice. From the west it is limited by the railway track Brno-Židenice, from the east by Koperníkova Street, from the north by Lazaretní Street and finally from the south by Bubeníčkova Street. Its area is approximately 45, 480 m2 which is 4,55 ha. From the urban perspective it is an intensive development in a separated block of the city with a protection zone. Total area is permeated by a few lines for pedestrians. The pedestrian zone provides better permeability of the area and better accessibility of the trade parterre. The buildings connect to surrounding development and respect the density of the integrity of the area. Intensive housing structure is regarded as "the city of short distance". The achievement of high density of housing development combines lots of various functions and relatively small built-up surface. While high-quality environment is preserved, people can find job oportunities in the intensive housing development without the need for transport. For achievement conception of compact city applies space urban planning. The shape of the estate directly impacted the principle of the proposal together with the city planning context of the current buildings. In the protective zone there is established a huge park with water reservoirs. The walk-through trade parterre is filled with many various functions, on its walkable roof is created a semi-public zone with skylights and freely introduced verdure. On the walkable roof there are independent blocks of apartments and public facilities. In the northern and southern corner are located public-service utilities and in the middle of this area there is a nursery and a kindergarden. In structural terms the building it is about cast-in-place concrete reinforced frame based on a white concrete foundation which has one underground level and five above-ground levels.
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Výborný, Václav. "Příprava realizace polyfunkčního domu v Pardubicích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240493.
Повний текст джерелаАнотація:
The main contens of the thesis is solving a construction-technological project substructure and the upper shell construction of a polyfunctional building in Pardubice. Excavation and foundation work are done in section A and B1 and B2. Drilled piles are foundation of a polyfunctional building. Drilled piles are support of reinforced concrete grillage, which are from strips foundation and foundation pads. Cast-in-place concrete frame is a form of load-bearing structure, which contens plate ceilings, pillars and walls. Peripheral masonry is from hellow clay blocks, which are between cast-in-place concrete frame. Diploma thesis includes technical report, plan of building side, schedule and the budget of the building, technological instructions, radon prevent, control and testing plan, safety, balance resources, selected constructional details, machinery composition, bill of quantities.
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Lin, Yu-Sheng, and 林煜盛. "Block-based Frame Interpolation under MPEG Environment." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/93723898343980335238.
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Chia-Ming, Wang, and 王嘉銘. "Multi-frame Motion Estimation Using Adaptive Block Matching." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/72090964200427397849.
Повний текст джерелаАнотація:
碩士國立中央大學
資訊工程研究所
88
Motion estimation and detection is an important and interesting topic in computer vision. Many motion estimation approaches start from the computation of optical flow. However, it is well known that the optical flow vectors estimated with the conventional methods are usually quite noisy and inaccurate. To obtain more accurate optical flow estimation of an image, our basic idea is to use as much information as possible contained in a number of image frames. In this thesis, we use the correlation-based method. Two different approaches called the reference-frame approach and the incremental approach are used in estimating multi-frame optical flow. We adopt the constant velocity flow model in all of our work. Moreover, sub-pixel refinement is necessary for every estimations. Bilinear interpolation and three-step searching are used in sub-pixel refinement. Finally, we device the adaptive window selection scheme in template matching. The adaptive windows are selected with an efficient algorithm which is called the difference accumulation algorithm. The accuracy improvement is demonstrated in our experimental results.
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Meng, Qing-Jun, and 孟慶俊. "Data Synchronization Techniques On Combined Block And Frame Alignment Strategies." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/21671845306118123198.
Повний текст джерела
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Mukund, Sriram N. "Grassmannian Fusion Frames for Block Sparse Recovery and Its Application to Burst Error Correction." Thesis, 2013. http://etd.iisc.ernet.in/2005/3469.
Повний текст джерелаАнотація:
Fusion frames and block sparse recovery are of interest in signal processing and communication applications. In these applications it is required that the fusion frame have some desirable properties. One such requirement is that the fusion frame be tight and its subspaces form an optimal packing in a Grassmannian manifold. Such fusion frames are called Grassmannian fusion frames.
Grassmannian frames are known to be optimal dictionaries for sparse recovery as they have minimum coherence. By analogy Grassmannian fusion frames are potential candidates as optimal dictionaries in block sparse processing. The present work intends to study fusion frames in finite dimensional vector spaces assuming a specific structure useful in block sparse signal processing.
The main focus of our work is the design of Grassmannian fusion frames and their implication in block sparse recovery. We will consider burst error correction as an application of block sparsity and fusion frame concepts.
We propose two new algebraic methods for designing Grassmannian fusion frames. The first method involves use of Fourier matrix and difference sets to obtain a partial Fourier matrix which forms a Grassmannian fusion frame. This fusion frame has a specific structure and the parameters of the fusion frame are determined by the type of difference set used.
The second method involves constructing Grassmannian fusion frames from Grassmannian frames which meet the Welch bound. This method uses existing constructions of optimal Grassmannian frames. The method, while fairly general, requires that the dimension of the vector space be divisible by the dimension of the subspaces.
A lower bound which is an analog of the Welch bound is derived for the block coherence of dictionaries along with conditions to be satisfied to meet the bound. From these results we conclude that the matrices constructed by us are optimal for block sparse recovery from block coherence viewpoint.
There is a strong relation between sparse signal processing and error control coding. It is known that burst errors are block sparse in nature. So, here we attempt to solve the burst error correction problem using block sparse signal recovery methods. The use of Grassmannian fusion frames which we constructed as optimal dictionary allows correction of maximum possible number of errors, when used in conjunction with reconstruction algorithms which exploit block sparsity. We also suggest a modification to improve the applicability of the technique and point out relationship with a method which appeared previously in literature.
As an application example, we consider the use of the burst error correction technique for impulse noise cancelation in OFDM system. Impulse noise is bursty in nature and severely degrades OFDM performance. The Grassmannian fusion frames constructed with Fourier matrix and difference sets is ideal for use in this application as it can be easily incorporated into the OFDM system.
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Ching-Wei, Shih. "Fast Block Size Decision For Inter Frame In H.264/AVC." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0016-1303200709270922.
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Shih, Ching-Wei, and 施清偉. "Fast Block Size Decision For Inter Frame In H.264/AVC." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/28688996638068461509.
Повний текст джерелаАнотація:
碩士國立清華大學
資訊系統與應用研究所
94
H. 264 is the latest coding standard for video compression. It has a lot of industry applications for wired or wireless transmission. However, the H.264 requires complex computation for motion estimation because it tries to find the best subdivision for each 16 x 16 block. We will improve the computational time of the inter prediction for P frames in H.264 video. Our proposed method first categorise macroblocks into two types, “skipped” and “not skipped”. Then, our method tries to find the most appropriate sub-block for motion estimation. Because our method does not involve computation for 16 x 16 blocks, 16 x 8 or 8 x 16 blocks for motion estimation it can reduce the computation time.
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(10693164), Chen Ma. "Modeling Alternatives for Implementing the Point-based Bundle Block Adjustment." Thesis, 2021.
Знайти повний текст джерелаАнотація:
This thesis examines the multilinear equations of the calibrated pinhole camera.
The multilinear equations describe the linear relations between camera parameters and image observations in matrix or tensor formats.
This thesis includes derivations and analysis of the trilinear equations through the point feature relation. For the four-frame and more than four frame cases, this paper gives derivations and analysis using a combination of the bilinear and trilinear equations to represent general multi-frame point geometry. As a result, a three-frame model (TFM) for general multi-frame point geometry is given. This model provides a concise set of minimal and sufficient equations and minimal unknowns.
Based on the TFM, there are two bundle adjustment (BA) approaches developed.
The TFM does not involve the object parameters/coordinates necessary and indispensable for the collinearity equation employed by BA.
The two methods use TFM as the condition equation fully and partially, replacing the collinearity equation.
One operation using both TFM and the collinearity equation is designed to engage the object structures' prior knowledge.
The synthetical and real data experiments demonstrate the rationality and validity of the TFM and the two TFM based methods.
When the unstable estimate of the object structures appears, the TFM-based BA methods have a higher acceptance ratio of the adjustment results.
32
Chen, Yue-Lin, and 陳岳麟. "Space-Time Block Code with Interblock Memory for LTE-Advanced Frame Structure." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/56xv4a.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電機工程系所
105
In the specification of 4th generation wireless system(4G) project Long Term Evolution Advanced(LTE-Advanced), the up-transmit code frames in the base stations (BS) are required to meet the standard of two antennas and three time slots. In this thesis, we proposed a new coding scheme called Space-Time Block Code with Interblock Memory for LTE-Advanced Frame Structure. The proposed scheme is designed by the combination of interblock memory code and multilevel STBC. The simulation result shows that this new scheme can achieve full diversity, full rate transmission and good error performance. Besides, the coding design provides more flexibility and low decoding complexity.
33
Tsai, Tung-Yuan, and 蔡東源. "Layered Video Coding Based on Displaced Frame Difference Prediction and Multiresolution Block-Matching." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/65291667394929388201.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
89
In many scalable coding systems, motion compensation is performed on the original high-resolution video sequence. This implies that the motion compensation process can't be identically replicated at the low resolution decoder, causing an accumulation of error in the decoded lower layer video sequence. It is known as drift. To solve this problem, in this thesis, we present a novel video coding scheme based on displaced frame difference (DFD) prediction and multiresolution block-matching for layered transmission. Since existing scalable coding systems use one DFD for all layers, it results in error accumulated in the lower layers. Hence, we use a multiresolution block-matching scheme, which has its own DFD at each layer, to eliminate the problem. However, it still has the drawback that the DFDs among different layers are coded independently. Therefore, the objective of DFD prediction is to remove the correlation among these DFDs to further enhance the efficiency for DFD encoding. We use a multistage motion vector quantization (MSMVQ) algorithm to achieve multiresolution block-matching. In the MSMVQ, the block-matching process is decomposed into several stages. Each stage has its own resolution, which can be prespecified before the design. Based on the motion vectors selected from earlier stages, the block-matching operations at later stages are then executed in higher resolutions to further refine the results of motion estimation. DFD prediction scheme is implemented by taking the reconstructed DFD at the current layer as the predicted DFD of the next higher layer. Simulation results show that our video coding scheme outperforms multiresolution method without DFD prediction and it can significantly improve the drift problem. Therefore, our algorithm is effective for the applications where high rate-distortion performance and low computational complexity for video coding are required.
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Yeo, Hangu. "A novel block-based motion estimation algorithm and architectures for inter-frame video coding." 1997. http://catalog.hathitrust.org/api/volumes/oclc/39328827.html.
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35
Hsiao, Yi-Hon, and 蕭奕弘. "Fast Multi-frame Block Matching Motion Estimation with Precise Prediction in Video Compression System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/64415304313158897357.
Повний текст джерелаАнотація:
碩士國立中央大學
電機工程研究所
92
Motion estimation plays an extremely important role in the video coding. The objective of the motion estimation is to remove the temporal redundancy between video frames so that the motion compensated frames can be coded efficiently. Multi-frame motion-compensated prediction extends the spatial displacement vector utilized in blocking-based hybrid video coding by a variable frame reference permitting the use of more frames than the previously decoded one for motion-compensated prediction. The multi-frame buffer stores frames at encoder and decoder that efficient for motion-compensated prediction. The use of multiple frames for motion compensation in most cases provides significantly improved coding gain. The multiple reference picture selection in H.264 allows the encoder store up to five previous frames for motion estimation. However, the complexity will increase five times dramatically. Numerous fast search algorithms in single-frame motion estimation are proposed in the past. As we know, a good initial point can speed up the velocity of fast search algorithm. Our proposed algorithm is focus on multi-frame condition, and provides more precisely prediction as initial point.
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Li, Wei Bang, and 李威邦. "Block Motion Decision and Motion Vector Composition in H.264 Video Frame skipping Transcoding." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/32807835188132505045.
Повний текст джерелаАнотація:
碩士國立交通大學
資訊科學與工程研究所
97
In recent years, many multimedia applications such as real-time video streaming systems, videoconference, handheld media systems, and high-speed video browsing through networks are required. Users expect to receive high quality of video under limited network bandwidth and established hardware equipments. Oppositely, system providers pursue services of high video quality through low bit-rate transmission in order to reduce the cost and provide more services. In this thesis, we focus on a frame-skipping transcoding methods to reduce the bit-rate for H.264/AVC video coding. We have proposed block mode decision methods, motion vector composition methods for frame-skipping transcoding. Experimental results show that, compared with H.264/AVC and other algorithms, the proposed methods can save a lot of computational cost. The performance can be improved by maintaining visual quality at low bit-rate.
37
Li, Wei-Shiu, and 李韋序. "Error Concealment for Whole-frame Loss Through Effective Block Size Decision In H.264." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/4k9gmx.
Повний текст джерелаАнотація:
碩士國立東華大學
電機工程學系
96
In low bit-rate video coding, a single packet usually contains a whole frame. Any packet loss could cause serious error. In this thesis, an error concealment algorithm is proposed to deal with this issue for H.264/AVC video bitstream. For correctly decoded frames, some useful information is recorded and a probabilistic table is built. The block size decision of each macroblock (MB) in the lost frame is estimated by this table. Then, we use different strategies to get the motion vector according different estimated block size for recovering the lost MB. Experimental results show that our proposed algorithm outperforms the other existing algorithms in terms of objective and subjective qualities.
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Yeh, Chin-Kun, and 葉錦坤. "Fast Global Disparity Vector Estimation and Block Mode Decision for Anchor Frame in Multiview Video Coding." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/gm8gb4.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電機工程系研究所
96
In July 2006 the Joint Video Team (JVT) started working on the multiview video coding (MVC) extension for H.264 video. In Oct. 2007 multiview video has also been added as an option in ITU Internet protocol TV (IPTV) service. So it shows that multiview video system is getting more attention in the near future. The H.264 MVC extension achieves excellent coding efficiency by not only inheriting from H.264 video standard but also incorporating new tools for inter-view prediction. As a result, a huge amount of computational complexity is involved, and how to reduce the complexity of encoding process becomes an important issue. In previous work, most researchers proposed to expedite the motion estimation across the temporal axis by utilizing the inter-view relationship to save the computational load on MVC, but few of them considered to reduce the complexity spent in the inter-view coding. In this thesis, we speed up the MVC inter-view coding by proposing a fast global disparity vector (GDV) estimation based on the edge projection map, and also present a fast block mode decision for the MVC anchor frames based on the obtained GDV with motion skip (MS) mode enabled. Experimental results show that our proposed method can reduce the complexity while keeping R-D performances for MVC anchor frame encoding.
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HSIEH, Chia-Chun, and 謝佳峻. "Fast CU and PU mode decision methods based on their neighboring block information for HEVC inter-frame coding." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/65a953.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
電機工程系
104
With the advance of multimedia communication technologies and widespread smart phones related applications, video coding efficiency has been extensively improved recently. The newest video coding standard, H.265/HEVC, is designed to encode high resolution video, 4K Ultra HD and 8K Ultra HD, with high fidelity, which can provide twice the compression ratio under the same encoding quality. To meet this high efficiency encoding targets, it requires high time complexity and wide transmission bandwidth. In the HEVC coder, it adopts Coding Unit (CU), Prediction Unit (PU), and Transform Unit (TU) to perform motion estimation/compensation and entropy coding, in which a best encoding mode has to be carried out based on exhaustive RD-cost evaluation procedures. For inter-frame coding, this optimal coding mode decision process is very time consuming and demands 60%~70% of the total encoding time. To speed up the HEVC encoding process, we proposed to determine the encoding mode of the current coding unit with reference to neighboring ones, which can be carried out by: (1) Utilizing the coding information of neighboring CUs to early determine whether to early terminate the current CU encoding to or proceed directly to next depth CU coding; (2) Utilizing the coding information of neighboring PUs to minimize the range of PU mode decision to determine the best PU coding mode. The proposed HEVC encoding method is designed to integrate the above two schemes to speed up the process. Experiments show that the proposed method can reduce the encoding time to 72.53% smaller, with acceptable bitrate increment and PSNR reduction.
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Martins, João Manuel Carrilho Gil. "Time-Interleaved Block Windowed Burst OFDM: Channel Estimation and Synchronization techniques." Master's thesis, 2020. http://hdl.handle.net/10316/92199.
Повний текст джерелаАнотація:
Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e TecnologiaNo contexto da indústria de telecomunicações, as comunicações móveis desempenham um papel muito importante devido ao seu impacto na economia e na sociedade global. As expectativas aumentam com a introdução da quinta geração (5G) que permite o acesso dos utilizadores em qualquer lugar com elevada fiabilidade e qualidade de serviço.Dentro deste contexto, é usado o Orthogonal Frequency Division Multiplexing (OFDM) que garante robustez contra canais seletivos no domínio da frequência, fornece elevadas taxas de transmissão de dados e fácil implementação baseada na transformada discreta de Fourier.No entanto, esta técnica apresenta uma eficiência espectral limitada, baixa eficiência energética e sensibilidade a erros de sincronismo.Como alternativa, foram desenvolvidas técnicas de modulação híbridas, como o Time Interleaved Block Windowed Burst-OFDM (TIBWB-OFDM).Esta dissertação desenvolve o modelo do transceptor TIBWB-OFDM através da introdução de técnicas adequadas a um cenário de comunicações reais sem fios. Consequentemente, os principais desafios e foco deste trabalho passaram pelo desenvolvimento de algoritmos de estimação de canal e sincronismo de tramas. Um passo importante para obter uma sincronização de tramas fiável é a escolha de preâmbulos com propriedades de correlação ótimas, como por exemplo, as sequências de Zadoff-Chu (ZC). Os resultados experimentais mostram que aplicando algoritmos de correlação e um dispositivo de limiar, é possível detectar perfeitamente o ínicio de cada trama TIBWB-OFDM. Em simultâneo, as sequências de ZC foram também aplicadas no contexto de estimação de canal através da aplicação de estimadores e algoritmos desenvolvidos baseados no OFDM.Desta forma, esta dissertação propõe um método conjunto de estimação de canal e sincronismo de tramas, aplicado ao TIBWB-OFDM, tomando partido das sequências ZC amplificadas.
In the segment of communications industry, wireless mobile communications are one of the most important innovations of our times due to its impact in the global economy and society. Expectations grow with the arrival and demands that the fifth generation of mobile telecommunications (5G) brings associated with an everywhere user access with better reliability and quality. In this context, Orthogonal Frequency Division Multiplexing (OFDM) is a widely used system that guarantees robustness against frequency selectivity channels, provide high data transmission rates and a easy implementation based on the discrete Fourier transform. However, this technique has high limited spectral efficiency, low power efficiency and sen- sitivity to synchronization errors. As an alternative, hybrid modulation techniques such as the time interleaved block windowed burst orthogonal frequency division multiplexing (TIBWB-OFDM) were developed.This thesis develops the TIBWB-OFDM transceiver model and the modifications necessary to implement this technique in a real wireless link scenarios. Hence, channel estimation and frame synchronization algorithms were the key challenges and focus of this work. An important step to achieve reliable frame synchronization is the choice of preamble sequences with optimum correlation proprieties, such as the Zadoff-Chu (ZC) sequences. Our experimental results show that by applying a correlation algorithm and a threshold device it is possible to detect perfectly each TIBWB-OFDM frame beginning. On the other hand, ZC sequences were also used to acquire the channel information by applying estimators and algorithms based on the OFDM technique.Therefore, this thesis proposes a joint channel and frame synchronization esti- mation using power amplified ZC sequences as preambles in the TIBWB-OFDM method.