Дисертації з теми "Low computational complexity algorithms"
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Troiani, Chiara. "Vision-Aided Inertial Navigation : low computational complexity algorithms with applications to Micro Aerial Vehicles." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENM021/document.
Повний текст джерелаAccurate egomotion estimation is of utmost importance for any navigation system.Nowadays di_erent sensors are adopted to localize and navigate in unknownenvironments such as GPS, range sensors, cameras, magnetic field sensors, inertialsensors (IMU). In order to have a robust egomotion estimation, the information ofmultiple sensors is fused. Although the improvements of technology in providingmore accurate sensors, and the efforts of the mobile robotics community in thedevelopment of more performant navigation algorithms, there are still openchallenges. Furthermore, the growing interest of the robotics community in microrobots and swarm of robots pushes towards the employment of low weight, low costsensors and low computational complexity algorithms. In this context inertial sensorsand monocular cameras, thanks to their complementary characteristics, low weight,low cost and widespread use, represent an interesting sensor suite.This dissertation represents a contribution in the framework of vision-aided inertialnavigation and tackles the problems of data association and pose estimation aimingfor low computational complexity algorithms applied to MAVs.For what concerns the data association, a novel method to estimate the relative motionbetween two consecutive camera views is proposed. It only requires the observationof a single feature in the scene and the knowledge of the angular rates from an IMU,under the assumption that the local camera motion lies in a plane perpendicular to thegravity vector. Two very efficient algorithms to remove the outliers of the featurematchingprocess are provided under the abovementioned motion assumption. Inorder to generalize the approach to a 6DoF motion, two feature correspondences andgyroscopic data from IMU measurements are necessary. In this case, two algorithmsare provided to remove wrong data associations in the feature-matching process. Inthe case of a monocular camera mounted on a quadrotor vehicle, motion priors fromIMU are used to discard wrong estimations.For what concerns the pose estimation problem, this thesis provides a closed formsolution which gives the system pose from three natural features observed in a singlecamera image, once the roll and the pitch angles are obtained by the inertialmeasurements under the planar ground assumption.In order to tackle the pose estimation problem in dark or featureless environments, asystem equipped with a monocular camera, inertial sensors and a laser pointer isconsidered. The system moves in the surrounding of a planar surface and the laserpointer produces a laser spot on the abovementioned surface. The laser spot isobserved by the monocular camera and represents the only point feature considered.Through an observability analysis it is demonstrated that the physical quantities whichcan be determined by exploiting the measurements provided by the aforementionedsensor suite during a short time interval are: the distance of the system from the planarsurface; the component of the system speed that is orthogonal to the planar surface;the relative orientation of the system with respect to the planar surface; the orientationof the planar surface with respect to the gravity. A simple recursive method toperform the estimation of all the aforementioned observable quantities is provided.All the contributions of this thesis are validated through experimental results usingboth simulated and real data. Thanks to their low computational complexity, theproposed algorithms are very suitable for real time implementation on systems withlimited on-board computation resources. The considered sensor suite is mounted on aquadrotor vehicle but the contributions of this dissertations can be applied to anymobile device
Goussevskaia, Olga. "Computational complexity and scheduling algorithms for wireless networks." Konstanz Hartung-Gorre, 2009. http://d-nb.info/997891122/04.
Повний текст джерелаUdupa, Pramod. "Algorithmes parallèles et architectures évolutives de faible complexité pour systèmes optiques OFDM cohérents temps réel." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S039/document.
Повний текст джерелаIn this thesis, low-complexity algorithms and architectures for CO-OFDM systems are explored. First, low-complexity algorithms for estimation of timing and carrier frequency offset (CFO) in dispersive channel are studied. A novel low-complexity timing synchro- nization algorithm, which can withstand large amount of dispersive delay, is proposed and compared with previous proposals. Then, the problem of realization of low-complexity parallel architecture is studied. A generalized scalable parallel architecture, which can be used to realize any auto-correlation algorithm, is proposed. It is then extended to handle multiple parallel samples from ADC and provide outputs, which can match the input ADC rate. The scalability of the architecture for higher number of parallel outputs and different kinds of auto-correlation algorithms is explored. An algorithm-architecture approach is then applied to the entire CO-OFDM transceiver chain. At the transmitter side, radix-22 algorithm for IFFT is chosen and parallel Mul- tipath Delay Commutator (MDC) Feed-forward (FF) architecture is designed which con- sumes lesser resources compared to MDC FF architectures of radix-2/4. At the receiver side, efficient algorithm for Integer CFO estimation is adopted and efficiently realized with- out the use of complex multipliers. Reduction in complexity is achieved due to efficient architectures for timing synchronization, FFT and Integer CFO estimation. Fixed-point analysis for the entire transceiver chain is done to find fixed-point sensitive blocks, which affect bit error rate (BER) significantly. The algorithms proposed are validated using opti- cal experiments by the help of arbitrary waveform generator (AWG) at the transmitter and digital storage oscilloscope (DSO) and Matlab at the receiver. BER plots are used to show the validity of the system built. Hardware implementation of the proposed synchronization algorithm is validated using real-time FPGA platform
Danjean, Ludovic. "Low-Complexity Iterative Reconstruction Algorithms in Compressed Sensing." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579661.
Повний текст джерелаIn this paper we focus on two low-complexity iterative reconstruction algorithms in compressed sensing. These algorithms, called the approximate message-passing algorithm and the interval-passing algorithm, are suitable to recover sparse signals from a small set of measurements. Depending on the type of measurement matrix (sparse or random) used to acquire the samples of the signal, one or the other reconstruction algorithm can be used. We present the reconstruction results of these two reconstruction algorithms in terms of proportion of correct reconstructions in the noise free case. We also report in this paper possible practical applications of compressed sensing where the choice of the measurement matrix and the reconstruction algorithm are often governed by the constraint of the considered application.
Vorhies, John T. "Low-complexity Algorithms for Light Field Image Processing." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590771210097321.
Повний текст джерелаUppman, Hannes. "On Some Combinatorial Optimization Problems : Algorithms and Complexity." Doctoral thesis, Linköpings universitet, Programvara och system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-116859.
Повний текст джерелаSmith, Justin N. "Computational complexity, bounded rationality and the theory of games." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365642.
Повний текст джерелаLundqvist, Samuel. "Computational algorithms for algebras." Doctoral thesis, Stockholm : Department of Mathematics, Stockholm University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-31552.
Повний текст джерелаAt the time of doctoral defence, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript. Paper 6: Manuscript. Härtill 6 uppsatser.
Neyer, Gabriele. "Algorithms, complexity, and software engineering in computational geometry : case studies /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13586.
Повний текст джерелаBrooks, Duncan John. "Adaptive algorithms for low complexity equalizers in mobile communications." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312445.
Повний текст джерелаLi, Peng. "Low-complexity iterative detection algorithms for multi-antenna systems." Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/2192/.
Повний текст джерелаWang, Tong. "Low-complexity signal processing algorithms for wireless sensor networks." Thesis, University of York, 2012. http://etheses.whiterose.ac.uk/2844/.
Повний текст джерелаBorie, Richard Bryan. "Recursively constructed graph families : membership and linear algorithms." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8140.
Повний текст джерелаXia, Ge. "Parameterized algorithms and computational lower bounds: a structural approach." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4322.
Повний текст джерелаNussbaum, Doron Carleton University Dissertation Computer Science. "Directional separability in two and three dimensional space." Ottawa, 1988.
Знайти повний текст джерелаSchüldt, Christian. "Low-Complexity Algorithms for Echo Cancellation in Audio Conferencing Systems." Doctoral thesis, Blekinge Tekniska Högskola, Avdelningen för elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00541.
Повний текст джерелаDanjean, Ludovic. "Low Complexity Iterative Algorithms in Channel Coding and Compressed Sensing." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/307022.
Повний текст джерелаAlnawayseh, Saif Enad Ahmad. "Coded cooperative diversity with low complexity encoding and decoding algorithms." Thesis, Swansea University, 2011. https://cronfa.swan.ac.uk/Record/cronfa42648.
Повний текст джерелаHe, Qie. "Topics in discrete optimization: models, complexity and algorithms." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50237.
Повний текст джерелаCai, Fang. "Low-complexity Decoding Algorithms and Architectures for Non-binary LDPC Codes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1372338108.
Повний текст джерелаValkanova, Elena. "Algorithms for simple stochastic games." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003070.
Повний текст джерелаNagao, Atsuki. "Computational Complexity of Tree Evaluation Problems and Branching Program Satisfiability Problems." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199453.
Повний текст джерелаMercat, Alexandre. "Complexity Control for Low-Power HEVC Encoding." Thesis, Rennes, INSA, 2018. http://www.theses.fr/2018ISAR0035/document.
Повний текст джерелаThe Internet of Things (loT) is now a reality. Forthcoming applications will boost mobile video demand to an unprecedented level. The induced increase in computational complexity is a challenge when executing in real-time new video coding standards on embedded platforms, limited in computing, memory, and energy. New 4K UHD and 360-degree video contents coming with high spatial (SK, 16K) and temporal (120fp resolutions further complicate the problem. In this context, codecs such as HEVC (High Efficiency Vide Coding) must be worked on to reduce their complexity while preserving the bitrate and image quality. Th bounded energy density of embedded system's batteries requires designers to propose new methods scaling and controlling the complexity and energy consumption of HEVC codecs. This document presents a set of studies aiming at scaling and controlling the complexity, and therefore the energy consumption, of HEVC Intra encoding. Two methods of quad-tree partitioning prediction in "one-shot are proposed: one based on variance-aware statistic approach and one based on Machine Learning using data-mining classifiers. From the obtained prediction, a generic tunable complexity scheme of HEVC encoding is introduced. It expands the search space around the original partitioning prediction and allocates complexit in a frame while minimizing performance loss in terms of bitrate and visual quality. Finally, a real-time contr system is created that dynamically manages the encoding process to keep the encoding complexity under specific tarjet. It demonstrates the a licability of the mayor contributions of this document
Milliner, David Louis. "Low-complexity list detection algorithms for the multiple-input multiple-output channel." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37248.
Повний текст джерелаPowell, David Richard 1973. "Algorithms for sequence alignment." Monash University, School of Computer Science and Software Engineering, 2001. http://arrow.monash.edu.au/hdl/1959.1/8051.
Повний текст джерелаOliveira, Igor Carboni. "Complexidade computacional e o problema P vs NP." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275804.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
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Resumo: A teoria de complexidade computacional procura estabelecer limites para a eficiência dos algoritmos, investigando a dificuldade inerente dos problemas computacionais. O problema P vs NP é uma questão central em complexidade computacional. Informalmente, ele procura determinar se, para uma classe importante de problemas computacionais, a busca exaustiva por soluções é essencialmente a melhor alternativa algorítmica possível. Esta dissertação oferece tanto uma introdução clássica ao tema, quanto uma exposição a diversos teoremas mais avançados, resultados recentes e problemas em aberto. Em particular, o método da diagonalização é discutido em profundidade. Os principais resultados obtidos por diagonalização são os teoremas de hierarquia de tempo e de espaço (Hartmanis e Stearns [54, 104]). Apresentamos uma generalização desses resultados, obtendo como corolários os teoremas clássicos provados por Hartmanis e Stearns. Essa é a primeira vez que uma prova unificada desses resultados aparece na literatura
Abstract: Computational complexity theory is the field of theoretical computer science that aims to establish limits on the efficiency of algorithms. The main open question in computational complexity is the P vs NP problem. Intuitively, it states that, for several important computational problems, there is no algorithm that performs better than a trivial exhaustive search. We present here an introduction to the subject, followed by more recent and advanced results. In particular, the diagonalization method is discussed in detail. Although it is a classical technique in computational complexity, it is the only method that was able to separate strong complexity classes so far. Some of the most important results in computational complexity theory have been proven by diagonalization. In particular, Hartmanis and Stearns [54, 104] proved that, given more resources, one can solve more computational problems. These results are known as hierarchy theorems. We present a generalization of the deterministic hierarchy theorems, recovering the classical results proved by Hartmanis and Stearns as corollaries. This is the first time that such unified treatment is presented in the literature
Mestrado
Teoria da Computação
Mestre em Ciência da Computação
Chen, Jinghu. "Reduced complexity decoding algorithms for low-density parity check codes and turbo codes." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/6885.
Повний текст джерелаxiii, 117 leaves
Castura, Jeff. "Performance analysis and optimization of reduced complexity Low Density Parity Check decoding algorithms." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ53426.pdf.
Повний текст джерелаGoldar, Davila Alejandro. "Low-complexity algorithms for the fast and safe charge of Li-ion batteries." Doctoral thesis, Universite Libre de Bruxelles, 2021. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/320077.
Повний текст джерелаDoctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
Golovins, Eugene. "Low-Complexity Algorithms for Channel Estimation in Optimised Pilot-Assisted Wireless OFDM Systems." Doctoral thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/5213.
Повний текст джерелаSinnokrot, Mohanned Omar. "Space-time block codes with low maximum-likelihood decoding complexity." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31752.
Повний текст джерелаCommittee Chair: Barry, John; Committee Co-Chair: Madisetti, Vijay; Committee Member: Andrew, Alfred; Committee Member: Li, Ye; Committee Member: Ma, Xiaoli; Committee Member: Stuber, Gordon. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Islam, Mohammad Tauhidul, and University of Lethbridge Faculty of Arts and Science. "Approximation algorithms for minimum knapsack problem." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, c2009, 2009. http://hdl.handle.net/10133/1304.
Повний текст джерелаx, 85 leaves ; 29 cm
Liang, Ying, and 梁瑩. "A study on low complexity near-maximum likelihood spherical MIMO decoders." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43703987.
Повний текст джерелаLiang, Ying. "A study on low complexity near-maximum likelihood spherical MIMO decoders." Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43703987.
Повний текст джерелаKrug, Marcus [Verfasser], and D. [Akademischer Betreuer] Wagner. "Combinatorial and Geometric Aspects of Computational Network Construction : Algorithms and Complexity / Marcus Krug. Betreuer: D. Wagner." Karlsruhe : KIT-Bibliothek, 2012. http://d-nb.info/1019361921/34.
Повний текст джерелаVance, Pamela H. "Crew scheduling, cutting stock, and column generation : Solving huge integer programs." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/23333.
Повний текст джерелаCarlsson, Per. "Algorithms for Electronic Power Markets." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4668.
Повний текст джерелаKim, Eun Jung. "Parameterized algorithms on digraph and constraint satisfaction problems." Thesis, Royal Holloway, University of London, 2010. http://repository.royalholloway.ac.uk/items/4e3a1971-6e98-97a9-8e4f-9e1fdc76066a/9/.
Повний текст джерелаRingh, Emil. "Low complexity algorithms for faster-than-Nyquistsign : Using coding to avoid an NP-hard problem." Thesis, KTH, Optimeringslära och systemteori, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-136936.
Повний текст джерелаDetta examensarbete handlar om vad som händer då kommunikationskanaler pressas till sin gräns och pulserna som bär data packas tätare i tiden. Detta kallas snabbare-än-Nyquist (FTN) och kommer att bryta mot Nyquists kriterium för intersymbolinterferens, vilket innebär att de databärande pulserna inte längre kommer vara ortogonala och att signalsamplen kommer vara beroende av mer än en skickad symbol. Det uppstår intersymbolinterferens (ISI) och dess konsekvenser studeras inom kanalmodellen AWGN. Vi visar att göra en maximum likelihood uppskattning baserat på dessa data är ett NP-svårt problem. Normalt används Viterbi algoritmen när man har ISI, men den har exponentiell komplexitet. På ett block med N symboler och interferens i storleken K symboler är komplexiteten O(N*2K) vilket gör att algoritmen är svår att använda i praktiska fall. Istället så föreslås en förkodning, som tillsammans med en avkodning reducerar komplexiteten. Kodningen appliceras blockvis och på ett block med N symboler är komplexiteten O(N2) för kodning/avkodning. Denna måste i båda fall föregås av en O(N3) beräkning, som dock behöver göras endast en gång. Simuleringar visar den föreslagna kodningens fördelar. I den första simuleringen testades den ihop med turbokodning med blocklängd på 6000 bitar och en kodningsgrad på 2/3. När FTN användes för att skicka 25% mer data krävdes det cirka 2.5 dB högre signal-till-brus-förhållande (SNR) för att den icke förkodade signalen skulle ha samma felfrekvens som den förkodade. När det förkodade fallet presterade felfritt gjorde det oförkodade fel på nästan alla block. Ett annat scenario som testades var det med korta koder, liten fördröjning och hög robusthet. I detta scenario skickades 600 bitar med en kodningsgrad på 2/3, alltså 400 bitar ren data. Genom att använda FTN med en dubbel packningsgrad, vilket innebär att 1200 bitar skickades under samma tid, var det möjligt att sänka kodningsgraden till 1/3, eftersom det bara var 400 bitar ren data som skulle överföras. Detta ökad robustheten i systemet ty då FTN fallet gjorde felfritt hade det klassiska Nyquist fallet fortfarande en felfrekvens på 0.19 för sina block. Det krävdes 1.25 dB högre SNR för Nyquist fallet att bli felfritt jämfört med FTN och lägre kodningsgrad.
Prasad, Kintali Shiva. "Realizable paths and the NL vs L problem." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42770.
Повний текст джерелаXiang, Gang. "Fast algorithms for computing statistics under interval uncertainty with applications to computer science and to electrical and computer engineering /." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Повний текст джерелаStarrett, Dean. "Optimal Alignment of Multiple Sequence Alignments." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194840.
Повний текст джерелаLichtenstein, Joseph. "Low computational complexity bit error rate simulation for personal communications systems in multipath and fading environments." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06102009-063138/.
Повний текст джерелаJi, Bo. "Design of Efficient Resource Allocation Algorithms for Wireless Networks: High Throughput, Small Delay, and Low Complexity." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354641556.
Повний текст джерелаMattsson, Per. "The Asymmetric Traveling Salesman Problem." Thesis, Uppsala universitet, Matematiska institutionen, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-132624.
Повний текст джерелаSu, Chorng-Yann, and 蘇崇彥. "The Study of Low Computational Complexity Enhanced Zerotree Coding Algorithm." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/18205327675769242225.
Повний текст джерела國立交通大學
電機與控制工程系
88
In this study, we present a low computational complexity enhanced zerotree coding algorithm and apply it to the coding of arbitrarily shaped images. The algorithm contains three main parts. The first part is about transformation, including extending the shape-adaptive discrete wavelet transform (SA-DWT) to translation-invariant SA-DWT (TI-SA-DWT), and presenting a fast convolution algorithm for the filtering with odd length symmetric filters. The second part is about compression performance, including proposing an computationally simple adaptive multi-subband decomposition (AMSD) to elevate the peak-signal to noise ratio (PSNR), and designing a band flag scheme (BFS) to speed up the execution of zerotree coding. The third part is about low memory implementation, including using recursive programming and using the top bits of coefficients to serve as flags so that the working memory can be reduced significantly and the cost of hardware implementation can be decreased. Experimental results show that in transform time, using the fast convolution algorithm can reduce at least 13% of DWT time and 37% of inverse DWT time; in PSNR value, using AMSD can further elevate the value by 0.1~4dB; in the number of comparisons for searching zerotrees, using BFS can reduce the number of comparisons up to 60% of the original one; in memory requirement, for a 768*512 color image, using the proposed method can reduce the amount of memory up to 5.3 MBytes compared with the state-of-the-art zerotree coder, set partitioning in hierarchical trees (SPIHT). Experimental results verify that the proposed algorithm is indeed executable and outperforms the other related techniques. Therefore, it can be extensively applied to the coding of various images.
Lin, Cheng, and 林成. "Low Computational Complexity Algorithm forH.264/AVC Video Frame-skipping Transcoding." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/61705566894631845556.
Повний текст джерела國立中央大學
通訊工程研究所
100
H.264/AVC supports many advanced compression techniques that can achieve better coding performance than the previous standards, and applications of H.264/AVC become popular and important in network multimedia services. However, because different networks might have different limitations of channel bandwidth, it is often needed to reduce the bit-rate of the coded video bit streams. Frame-skipping transcoding is one way to solve the problem. The most straightforward method for frame-skipping transcoding is to decode the video stream and re-encode the reconstructed video sequences after frame-skipping. Because H.264/AVC supports many advanced compression techniques, the computational complexity of the fully decoding and re-encoding process is extremely high. If we prefer to reduce the computational complexity, reusing information existing in the original incoming video stream can achieve this goal. But the coding performance will decrease significantly. Therefore, we propose a hierarchical mode decision, motion vector composition and multiple reference frames selection, and then combine with them for frame-skipping transcoding. The experimental results show that our proposed algorithms can maintain the coding performance and speed up transcoding process simultaneously.
Huang, Shang-en, and 黃上恩. "Low Computational Complexity Algorithm for HEVC Intra Prediction with Support Vector Machine." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/09461317827186011784.
Повний текст джерела國立中央大學
通訊工程學系
103
High efficiency video coding (HEVC) is the state-of-the-art video coding standard. HEVC is better than the previous video coding standard H.264/AVC on the coding efficient. The coding unit(CU) of HEVC uses a Quadtree-based coding structure to increase coding performance. In order to predict more accurately, using 35 prediction modes in intra prediction. Simultaneously, it also increases its coding complexity. Hence, in this thesis, we proposed an SVM based fast intra CU depth decision algorithm is proposed to reduce the computational complexity. It is convenient to develop the criterion of early CU splitting and termination by applying SVM with features extracted from spatial domain, frequency domain, including Variance, low-frequency AC value, and neighboring CU depth. After extracting the features, SVM predict the current CU will be split or be terminated. In intra prediction, we use sobel operator to distinguish the direction of PU(Prediction Unit) and the neighbor mode to be the candidates of rough mode decision and we also reduce the candidates of rate-distortion optimization. The experimental results show that our proposed algorithm achieves 48.3% encoding time saving on average without significant degradation of coding performance.
Gorur, Pushkar. "Bitrate Reduction Techniques for Low-Complexity Surveillance Video Coding." Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2681.
Повний текст джерелаChang, Kai-Hsiung, and 張凱雄. "A Low Computational-Complexity QRS Complex Detection Algorithm Realized in an MCU-Based System and Tested with a Three-Lead Synthetic ECG Generator." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/17473511076822651106.
Повний текст джерела國立成功大學
電機工程學系碩博士班
97
A normal electrocardiogram (ECG) cycle basically consists of the P-wave, the QRS complex and the T-wave, which reflect the different electrical activities within the heart. An electrocardiogram is a non-invasive tool that is used for recording the electrical activity within the heart, and from the observation of ECG morphology, doctors are able to diagnose different types of heart disease. Therefore, this paper first presents the design of an electrocardiogram measurement circuit module, which consists of the instrumentation amplifier, the Sallen-Key high-pass filter, the Sallen-Key low-pass filter, and the back stage amplifier. The ECG measurement circuit module is designed with the PSpice circuit simulation CAD to measure three lead electrocardiograms of Einthoven's Triangle and filter the noise within the measured waveforms, and then uses the operational amplifier to implement the circuits. Afterward, this paper simplifies and adopts a synthetic electrocardiogram model composed of three coupled differential equations proposed by Dr. McSharry et al. (2003), as well as utilizes an improved fourth-order Taylor series to quickly approximate the exponential function within the differential equation of a simplified synthetic ECG model so that, when studying ECG analytic algorithms, the graphical user interface (GUI) program “Synthetic Waveforms Control Panel”, developed by the author using LabVIEW, can be used to attain the desirable morphology of electrocardiogram as well as the time intervals between peaks (P, Q, R, S, T) and heart rate. Finally, this paper presents a low computational-complexity QRS complex detection algorithm, which can easily be implemented in a general processor or micro-controller. The algorithm adopts the derivative of the electrocardiogram waveform to accurately identify the peaks (the Q-, R-, and S-peaks) and calculate the heart rate and the duration of the QRS complex in real-time. Then we apply the QRS complex detection algorithm to design an MCU-based ECG measurement instrument, and test it with 12 electrocardiogram samples (with heart rates from 49.59 to 155.44 BPM). The experimental results show that the maximum relative error of the measured R-R interval with the new QRS complex detection algorithm is only 1.58%, while the more detailed experimental data will be discussed at the end of this paper. The low computational-complexity QRS complex detection algorithm and the 8-bit MCU-based ECG measurement system developed in this work has good potential for use in portable and reasonable measurement instruments.