7 research outputs found
Low-power Programmable Processor for Fast Fourier Transform Based on Transport Triggered Architecture
This paper describes a low-power processor tailored for fast Fourier
transform computations where transport triggering template is exploited. The
processor is software-programmable while retaining an energy-efficiency
comparable to existing fixed-function implementations. The power savings are
achieved by compressing the computation kernel into one instruction word. The
word is stored in an instruction loop buffer, which is more power-efficient
than regular instruction memory storage. The processor supports all
power-of-two FFT sizes from 64 to 16384 and given 1 mJ of energy, it can
compute 20916 transforms of size 1024.Comment: 5 pages, 4 figures, 1 table, ICASSP 2019 conferenc
Pruned Lightweight Encoders for Computer Vision
Latency-critical computer vision systems, such as autonomous driving or drone control, require fast image or video compression when offloading neural network inference to a remote computer. To ensure low latency on a near-sensor edge device, we propose the use of lightweight encoders with constant bitrate and pruned encoding configurations, namely, ASTC and JPEG XS. Pruning introduces significant distortion which we show can be recovered by retraining the neural network with compressed data after decompression. Such an approach does not modify the network architecture or require coding format modifications. By retraining with compressed datasets, we reduced the classification accuracy and segmentation mean intersection over union (mIoU) degradation due to ASTC compression to 4.9-5.0 percentage points (pp) and 4.4-4.0 pp, respectively. With the same method, the mIoU lost due to JPEG XS compression at the main profile was restored to 2.7-2.3 pp. In terms of encoding speed, our ASTC encoder implementation is 2.3x faster than JPEG. Even though the JPEG XS reference encoder requires optimizations to reach low latency, we showed that disabling significance flag coding saves 22-23% of encoding time at the cost of 0.4-0.3 mIoU after retraining.acceptedVersionPeer reviewe
AnalĂ˝za podmĂnek pohybu ÄŤeskĂ˝ch spotĹ™ebitelĹŻ mezi zdroji s legálnÄ› a nelegálnÄ› šĂĹ™enĂ˝m audiovizuálnĂm obsahem
VĂ˝zkumná zpráva shrnuje základnĂ zjištÄ›nĂ kvalitativnĂho vĂ˝zkumu ÄŤeskĂ˝ch konvergentnĂch publik vedenĂ©ho v letech 2018 a 2019, a to s dĹŻrazem na motivy, jeĹľ respondenty zahrnutĂ© do vĂ˝zkumnĂ©ho vzorku vedou k volbÄ› mezi jednotlivĂ˝mi aktuálnÄ› dostupnĂ˝mi zdroji audiovizuálnĂch obsahĹŻ. VĂ˝zkumnĂ© závÄ›ry, jeĹľ jsou v tĂ©to zprávÄ› struÄŤnÄ› shrnuty, se pĹ™itom obracejĂ ke dvÄ›ma klĂÄŤovĂ˝m otázkám: Za jakĂ˝ch podmĂnek a z jakĂ˝ch dĹŻvodĹŻ souÄŤasnĂ konzumenti televiznĂch a filmovĂ˝ch obsahĹŻ volĂ jako zdroje tÄ›chto obsahĹŻ zdroje neoficiálnĂ? A co je naopak vede k tomu, aby dali pĹ™ednost zdrojĹŻm oficiálnĂm?The research report summarizes the basic findings of qualitative research of Czech convergent audiences conducted in 2018 and 2019, with an emphasis on the motives that lead respondents included in the research sample to choose between individual currently available sources of audiovisual content. The research conclusions briefly summarized in this report address two key questions: Under what conditions and for what reasons do current consumers of television and film content choose unofficial sources as sources of such content? And what, on the other hand, leads them to prefer official sources
Image and Video Coding Techniques for Ultra-low Latency
The next generation of wireless networks fosters the adoption of latency-critical applications such as XR, connected industry, or autonomous driving. This survey gathers implementation aspects of different image and video coding schemes and discusses their tradeoffs. Standardized video coding technologies such as HEVC or VVC provide a high compression ratio, but their enormous complexity sets the scene for alternative approaches like still image, mezzanine, or texture compression in scenarios with tight resource or latency constraints. Regardless of the coding scheme, we found inter-device memory transfers and the lack of sub-frame coding as limitations of current full-system and software-programmable implementations.publishedVersionPeer reviewe
Mapa audiovizuálnĂho pole v ÄŚeskĂ© republice z hlediska digitalizace a strategie pro jednotnĂ˝ digitálnĂ trh
VĂ˝zkumná zpráva popisuje stav audiovizuálnĂho pole v ÄŚR, tj. základnĂ struktury, klĂÄŤovĂ© aktĂ©ry a praxe v produkci, distribuci a spotĹ™ebÄ› audiovizuálnĂch dÄ›l. Mezi struktury audiovizuálnĂho pole Ĺ™adĂme technickou infrastrukturu, právnĂ normy, obchodnĂ (tj. produkÄŤnĂ a distribuÄŤnĂ) modely, základnĂ socioekonomickĂ© parametry pracovnĂho trhu v audiovizuálnĂm prĹŻmyslu, státnĂ kulturnĂ politiku a širšà sociokulturnĂ kontext. Mezi aktĂ©ry audiovizuálnĂho pole zahrnujeme jednak aktĂ©ry hodnotovĂ©ho Ĺ™etÄ›zce, kteřà se podĂlejĂ na vĂ˝voji, vĂ˝robÄ› a šĂĹ™enĂ audiovizuálnĂho dĂla, a jednak samotnĂ© spotĹ™ebitele.The research report describes the state of the audiovisual field in the Czech Republic, i.e. the basic structures, key actors and practices in the production, distribution and consumption of audiovisual works. Among the structures of the audiovisual field we include technical infrastructure, legal standards, business (i.e. production and distribution) models, basic socio-economic parameters of the labour market in the audiovisual industry, state cultural policy and wider socio-cultural context. Among the actors of the audiovisual field we include, on the one hand, actors of the value chain who participate in the development, production and distribution of audiovisual works and, on the other hand, consumers themselves
Implementation of Fast Fourier Transformation on Transport Triggered Architecture
V tĂ©to práci je navrhnut energeticky ĂşspornĂ˝ procesor typu TTA (Transport Triggered Architecture) pro vĂ˝poÄŤet rychlĂ© Fourierovy transformace (FFT). Návrh procesoru byl vytvoĹ™en na mĂru pouĹľitĂ©mu algoritmu pomocĂ speciáonĂch funkÄŤnĂch jednotek. Algoritmus byl realizován jako posloupnost instrukcĂ tak, Ĺľe vÄ›tšina vĂ˝poÄŤtu probĂhá ve smyÄŤce obrahujĂcĂ pouze jedionu paralelnĂ instrukci. Tato instrukce je umĂstÄ›na do instrukÄŤnĂho bufferu, odkud je potom volána mĂsto instrukÄŤnĂ pamÄ›ti. DĂky tomu se dá docĂlit nižšà spotĹ™eby, neboĹĄ volánĂ z instrukÄŤnĂho bufferu je efektivnÄ›jšà neĹľ volánĂ z instrukÄŤnĂ pamÄ›ti. Program byl zkompilován na ÄŤasovĂ©m modelu procesoru a ÄŤasová simulace potvrdila správnost návrhu. SoučástĂ práce jsou rovněž pomocnĂ© programy v Pythonu, kterĂ© sloužà ke generaci referenÄŤnĂch vĂ˝sledkĹŻ a automatickĂ© simulaci a porovnánĂ vĂ˝sledkĹŻ simulace s referencĂ.The thesis proposes an energy-efficient processor architecture for computing a Fast Fourier Transform (FFT) using a Transport Triggered Architecture (TTA) template. The architecture was specifically tailored to a custom instruction schedule using several custom functional units (FUs). The instruction schedule for computing the algorithm was developed in a way that most of the computation is done in a loop containing only one instruction word. This word is stored into an instruction loop buffer which is more power-efficient than a regular memory storage. Thus a power consumption can be lowered. A timed model of the processor and the instruction schedule were developed, verified the approach and suggested further improvements. Python programs for generating referencing and an automatic verification of the timed models were developed to aid the design process.
Fast optical receiver for measurement application
Tato bakalářská práce se zabĂ˝vá problĂ©mem detekce spojitĂ©ho optickĂ©ho signálu o~frekvencĂch blĂĹľĂcĂch se 100 MHz. Teoretická část práce popisuje princip funkce základnĂch typĹŻ fotodiod a jejich parametry vÄŤetnÄ› náhradnĂho schĂ©matu a parazitnĂch vlastnostĂ. Dále se zabĂ˝vá vĂ˝bÄ›rem vhodnĂ©ho zapojenĂ a vhodnĂ˝ch prvkĹŻ tohoto zapojenĂ, zejmĂ©na fotodiody a operaÄŤnĂho zesilovaÄŤe. V~praktickĂ© části probÄ›hne simulace zapojenĂ v~softwaru Tina-TI a pokusnĂ© měřenĂ vybranĂ˝ch fotodiod. PotĂ© jsou navrĹľeny desky plošnĂ˝ch spojĹŻ a jejich vĂ˝roba, osazenĂ a následnĂ© testovánĂ a ladÄ›nĂ pro dosaĹľenĂ optimálnĂch parametrĹŻ.This bachelor's thesis analyzes the problem of a detection of analog optical signals on frequencies nearing 100 MHz. The theoretical part describes a principle of the basic photodiode types and their parameters including their equivalent circuit and parasitic characteristics. Next we discuss the ideal circuit selection and its components, especially the photodiode and operational amplifier. In the practical part we simulate the circuit in the software Tina-TI and measure chosen photodiodes. After that, real circuit boards are designed, constructed, soldered, tested and adjusted to achieve the best performance possible.