5 research outputs found

    Bi-criteria Pipeline Mappings for Parallel Image Processing

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    Mapping workflow applications onto parallel platforms is a challenging problem, even for simple application patterns such as pipeline graphs. Several antagonistic criteria should be optimized, such as throughput and latency (or a combination). Typical applications include digital image processing, where images are processed in steady-state mode. In this paper, we study the mapping of a particular image processing application, the JPEG encoding. Mapping pipelined JPEG encoding onto parallel platforms is useful for instance for encoding Motion JPEG images. As the bi-criteria mapping problem is NP-complete, we concentrate on the evaluation and performance of polynomial heuristics

    High performance computing with FPGAs

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    Field-programmable gate arrays represent an army of logical units which can be organized in a highly parallel or pipelined fashion to implement an algorithm in hardware. The flexibility of this new medium creates new challenges to find the right processing paradigm which takes into account of the natural constraints of FPGAs: clock frequency, memory footprint and communication bandwidth. In this paper first use of FPGAs as a multiprocessor on a chip or its use as a highly functional coprocessor are compared, and the programming tools for hardware/software codesign are discussed. Next a number of techniques are presented to maximize the parallelism and optimize the data locality in nested loops. This includes unimodular transformations, data locality improving loop transformations and use of smart buffers. Finally, the use of these techniques on a number of examples is demonstrated. The results in the paper and in the literature show that, with the proper programming tool set, FPGAs can speedup computation kernels significantly with respect to traditional processors

    Efficient high-performance ASIC implementation of JPEG-LS encoder

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    This paper introduces an innovative design which implements a high-performance JPEG-LS encoder. The encoding process follows the principles of the JPEG-LS lossless mode. The proposed implementation consists of an efficient pipelined JPEG-LS encoder, which operates at a significantly higher encoding rate than any other JPEG-LS hardware or software implementation while keeping area small. ยฉ 2007 EDAA

    Capsule endoscopy system with novel imaging algorithms

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    Wireless capsule endoscopy (WCE) is a state-of-the-art technology to receive images of human intestine for medical diagnostics. In WCE, the patient ingests a specially designed electronic capsule which has imaging and wireless transmission capabilities inside it. While the capsule travels through the gastrointestinal (GI) tract, it captures images and sends them wirelessly to an outside data logger unit. The data logger stores the image data and then they are transferred to a personal computer (PC) where the images are reconstructed and displayed for diagnosis. The key design challenge in WCE is to reduce the area and power consumption of the capsule while maintaining acceptable image reconstruction. In this research, the unique properties of WCE images are identified by analyzing hundreds of endoscopic images and video frames, and then these properties are used to develop novel and low complexity compression algorithms tailored for capsule endoscopy. The proposed image compressor consists of a new YEF color space converter, lossless prediction coder, customizable chrominance sub-sampler and an efficient Golomb-Rice encoder. The scheme has both lossy and lossless modes and is further customized to work with two lighting modes โ€“ conventional white light imaging (WLI) and emerging narrow band imaging (NBI). The average compression ratio achieved using the proposed lossy compression algorithm is 80.4% for WBI and 79.2% for NBI with high reconstruction quality index for both bands. Two surveys have been conducted which show that the reconstructed images have high acceptability among medical imaging doctors and gastroenterologists. The imaging algorithms have been realized in hardware description language (HDL) and their functionalities have been verified in field programmable gate array (FPGA) board. Later it was implemented in a 0.18 ฮผm complementary metal oxide semiconductor (CMOS) technology and the chip was fabricated. Due to the low complexity of the core compressor, it consumes only 43 ยตW of power and 0.032 mm2 of area. The compressor is designed to work with commercial low-power image sensor that outputs image pixels in raster scan fashion, eliminating the need of significant input buffer memory. To demonstrate the advantage, a prototype of the complete WCE system including an FPGA based electronic capsule, a microcontroller based data logger unit and a Windows based image reconstruction software have been developed. The capsule contains the proposed low complexity image compressor and can generate both lossy and lossless compressed bit-stream. The capsule prototype also supports both white light imaging (WLI) and narrow band imaging (NBI) imaging modes and communicates with the data logger in full duplex fashion, which enables configuring the image size and imaging mode in real time during the examination. The developed data logger is portable and has a high data rate wireless connectivity including Bluetooth, graphical display for real time image viewing with state-of-the-art touch screen technology. The data are logged in micro SD cards and can be transferred to PC or Smartphone using card reader, USB interface, or Bluetooth wireless link. The workstation software can decompress and show the reconstructed images. The images can be navigated, marked, zoomed and can be played as video. Finally, ex-vivo testing of the WCE system has been done in pig's intestine to validate its performance

    ๋””์Šคํ”Œ๋ ˆ์ด ์žฅ์น˜๋ฅผ ์œ„ํ•œ ๊ณ ์ • ๋น„์œจ ์••์ถ• ํ•˜๋“œ์›จ์–ด ์„ค๊ณ„

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    ํ•™์œ„๋…ผ๋ฌธ (๋ฐ•์‚ฌ)-- ์„œ์šธ๋Œ€ํ•™๊ต ๋Œ€ํ•™์› : ์ „๊ธฐยท์ปดํ“จํ„ฐ๊ณตํ•™๋ถ€, 2016. 2. ์ดํ˜์žฌ.๋””์Šคํ”Œ๋ ˆ์ด ์žฅ์น˜์—์„œ์˜ ์••์ถ• ๋ฐฉ์‹์€ ์ผ๋ฐ˜์ ์ธ ๋น„๋””์˜ค ์••์ถ• ํ‘œ์ค€๊ณผ๋Š” ๋‹ค๋ฅธ ๋ช‡ ๊ฐ€์ง€ ํŠน์ง•์ด ์žˆ๋‹ค. ์ฒซ์งธ, ํŠน์ˆ˜ํ•œ ์–ดํ”Œ๋ฆฌ์ผ€์ด์…˜์„ ๋ชฉํ‘œ๋กœ ํ•œ๋‹ค. ๋‘˜์งธ, ์••์ถ• ์ด๋“, ์†Œ๋น„ ์ „๋ ฅ, ์‹ค์‹œ๊ฐ„ ์ฒ˜๋ฆฌ ๋“ฑ์„ ์œ„ํ•ด ํ•˜๋“œ์›จ์–ด ํฌ๊ธฐ๊ฐ€ ์ž‘๊ณ , ๋ชฉํ‘œ๋กœ ํ•˜๋Š” ์••์ถ•๋ฅ ์ด ๋‚ฎ๋‹ค. ์…‹์งธ, ๋ž˜์Šคํ„ฐ ์ฃผ์‚ฌ ์ˆœ์„œ์— ์ ํ•ฉํ•ด์•ผ ํ•œ๋‹ค. ๋„ท์งธ, ํ”„๋ ˆ์ž„ ๋ฉ”๋ชจ๋ฆฌ ํฌ๊ธฐ๋ฅผ ์ œํ•œ์‹œํ‚ค๊ฑฐ๋‚˜ ์ž„์˜ ์ ‘๊ทผ์„ ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์••์ถ• ๋‹จ์œ„๋‹น ๋ชฉํ‘œ ์••์ถ•๋ฅ ์„ ์‹ค์‹œ๊ฐ„์œผ๋กœ ์ •ํ™•ํžˆ ๋งž์ถœ ์ˆ˜ ์žˆ์–ด์•ผ ํ•œ๋‹ค. ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ด์™€ ๊ฐ™์€ ํŠน์ง•์„ ๋งŒ์กฑ์‹œํ‚ค๋Š” ์„ธ ๊ฐ€์ง€ ์••์ถ• ์•Œ๊ณ ๋ฆฌ์ฆ˜๊ณผ ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ๋ฅผ ์ œ์•ˆํ•˜๋„๋ก ํ•œ๋‹ค. LCD ์˜ค๋ฒ„๋“œ๋ผ์ด๋ธŒ๋ฅผ ์œ„ํ•œ ์••์ถ• ๋ฐฉ์‹์œผ๋กœ๋Š” BTC(block truncation coding) ๊ธฐ๋ฐ˜์˜ ์••์ถ• ๋ฐฉ์‹์„ ์ œ์•ˆํ•˜๋„๋ก ํ•œ๋‹ค. ๋ณธ ๋…ผ๋ฌธ์€ ์••์ถ• ์ด๋“์„ ์ฆ๊ฐ€์‹œํ‚ค๊ธฐ ์œ„ํ•˜์—ฌ ๋ชฉํ‘œ ์••์ถ•๋ฅ  12์— ๋Œ€ํ•œ ์••์ถ• ๋ฐฉ์‹์„ ์ œ์•ˆํ•˜๋Š”๋ฐ, ์••์ถ• ํšจ์œจ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ธฐ ์œ„ํ•˜์—ฌ ํฌ๊ฒŒ ๋‘ ๊ฐ€์ง€ ๋ฐฉ๋ฒ•์„ ์ด์šฉํ•œ๋‹ค. ์ฒซ ๋ฒˆ์งธ๋Š” ์ด์›ƒํ•˜๋Š” ๋ธ”๋ก๊ณผ์˜ ๊ณต๊ฐ„์  ์—ฐ๊ด€์„ฑ์„ ์ด์šฉํ•˜์—ฌ ๋น„ํŠธ๋ฅผ ์ ˆ์•ฝํ•˜๋Š” ๋ฐฉ๋ฒ•์ด๋‹ค. ๊ทธ๋ฆฌ๊ณ  ๋‘ ๋ฒˆ์งธ๋Š” ๋‹จ์ˆœํ•œ ์˜์—ญ์€ 2ร—16 ์ฝ”๋”ฉ ๋ธ”๋ก, ๋ณต์žกํ•œ ์˜์—ญ์€ 2ร—8 ์ฝ”๋”ฉ ๋ธ”๋ก์„ ์ด์šฉํ•˜๋Š” ๋ฐฉ๋ฒ•์ด๋‹ค. 2ร—8 ์ฝ”๋”ฉ ๋ธ”๋ก์„ ์ด์šฉํ•˜๋Š” ๊ฒฝ์šฐ ๋ชฉํ‘œ ์••์ถ•๋ฅ ์„ ๋งž์ถ”๊ธฐ ์œ„ํ•˜์—ฌ ์ฒซ ๋ฒˆ์งธ ๋ฐฉ๋ฒ•์œผ๋กœ ์ ˆ์•ฝ๋œ ๋น„ํŠธ๋ฅผ ์ด์šฉํ•œ๋‹ค. ์ €๋น„์šฉ ๊ทผ์ ‘-๋ฌด์†์‹ค ํ”„๋ ˆ์ž„ ๋ฉ”๋ชจ๋ฆฌ ์••์ถ•์„ ์œ„ํ•œ ๋ฐฉ์‹์œผ๋กœ๋Š” 1D SPIHT(set partitioning in hierarchical trees) ๊ธฐ๋ฐ˜์˜ ์••์ถ• ๋ฐฉ์‹์„ ์ œ์•ˆํ•˜๋„๋ก ํ•œ๋‹ค. SPIHT์€ ๊ณ ์ • ๋ชฉํ‘œ ์••์ถ•๋ฅ ์„ ๋งž์ถ”๋Š”๋ฐ ๋งค์šฐ ํšจ๊ณผ์ ์ธ ์••์ถ• ๋ฐฉ์‹์ด๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ 1D ํ˜•ํƒœ์ธ 1D SPIHT์€ ๋ž˜์Šคํ„ฐ ์ฃผ์‚ฌ ์ˆœ์„œ์— ์ ํ•ฉํ•จ์—๋„ ๊ด€๋ จ ์—ฐ๊ตฌ๊ฐ€ ๋งŽ์ด ์ง„ํ–‰๋˜์ง€ ์•Š์•˜๋‹ค. ๋ณธ ๋…ผ๋ฌธ์€ 1D SPIHT์˜ ๊ฐ€์žฅ ํฐ ๋ฌธ์ œ์ ์ธ ์†๋„ ๋ฌธ์ œ๋ฅผ ํ•ด๊ฒฐํ•  ์ˆ˜ ์žˆ๋Š” ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ๋ฅผ ์ œ์•ˆํ•œ๋‹ค. ์ด๋ฅผ ์œ„ํ•ด 1D SPIHT ์•Œ๊ณ ๋ฆฌ์ฆ˜์€ ๋ณ‘๋ ฌ์„ฑ์„ ์ด์šฉํ•  ์ˆ˜ ์žˆ๋Š” ํ˜•ํƒœ๋กœ ์ˆ˜์ •๋œ๋‹ค. ์ธ์ฝ”๋”์˜ ๊ฒฝ์šฐ ๋ณ‘๋ ฌ ์ฒ˜๋ฆฌ๋ฅผ ๋ฐฉํ•ดํ•˜๋Š” ์˜์กด ๊ด€๊ณ„๊ฐ€ ํ•ด๊ฒฐ๋˜๊ณ , ํŒŒ์ดํ”„๋ผ์ธ ์Šค์ผ€์ฅด๋ง์ด ๊ฐ€๋Šฅํ•˜๊ฒŒ ๋œ๋‹ค. ๋””์ฝ”๋”์˜ ๊ฒฝ์šฐ ๋ณ‘๋ ฌ๋กœ ๋™์ž‘ํ•˜๋Š” ๊ฐ ํŒจ์Šค๊ฐ€ ๋””์ฝ”๋”ฉํ•  ๋น„ํŠธ์ŠคํŠธ๋ฆผ์˜ ๊ธธ์ด๋ฅผ ๋ฏธ๋ฆฌ ์˜ˆ์ธกํ•  ์ˆ˜ ์žˆ๋„๋ก ์•Œ๊ณ ๋ฆฌ์ฆ˜์ด ์ˆ˜์ •๋œ๋‹ค. ๊ณ ์ถฉ์‹ค๋„(high-fidelity) RGBW ์ปฌ๋Ÿฌ ์ด๋ฏธ์ง€ ์••์ถ•์„ ์œ„ํ•œ ๋ฐฉ์‹์œผ๋กœ๋Š” ์˜ˆ์ธก ๊ธฐ๋ฐ˜์˜ ์••์ถ• ๋ฐฉ์‹์„ ์ œ์•ˆํ•˜๋„๋ก ํ•œ๋‹ค. ์ œ์•ˆ ์˜ˆ์ธก ๋ฐฉ์‹์€ ๋‘ ๋‹จ๊ณ„์˜ ์ฐจ๋ถ„ ๊ณผ์ •์œผ๋กœ ๊ตฌ์„ฑ๋œ๋‹ค. ์ฒซ ๋ฒˆ์งธ๋Š” ๊ณต๊ฐ„์  ์—ฐ๊ด€์„ฑ์„ ์ด์šฉํ•˜๋Š” ๋‹จ๊ณ„์ด๊ณ , ๋‘ ๋ฒˆ์งธ๋Š” ์ธํ„ฐ-์ปฌ๋Ÿฌ ์—ฐ๊ด€์„ฑ์„ ์ด์šฉํ•˜๋Š” ๋‹จ๊ณ„์ด๋‹ค. ์ฝ”๋”ฉ์˜ ๊ฒฝ์šฐ ์••์ถ• ํšจ์œจ์ด ๋†’์€ VLC(variable length coding) ๋ฐฉ์‹์„ ์ด์šฉํ•˜๋„๋ก ํ•œ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๊ธฐ์กด์˜ VLC ๋ฐฉ์‹์€ ๋ชฉํ‘œ ์••์ถ•๋ฅ ์„ ์ •ํ™•ํžˆ ๋งž์ถ”๋Š”๋ฐ ์–ด๋ ค์›€์ด ์žˆ์—ˆ์œผ๋ฏ€๋กœ ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” Golomb-Rice ์ฝ”๋”ฉ์„ ๊ธฐ๋ฐ˜์œผ๋กœ ํ•œ ๊ณ ์ • ๊ธธ์ด ์••์ถ• ๋ฐฉ์‹์„ ์ œ์•ˆํ•˜๋„๋ก ํ•œ๋‹ค. ์ œ์•ˆ ์ธ์ฝ”๋”๋Š” ํ”„๋ฆฌ-์ฝ”๋”์™€ ํฌ์Šคํ„ฐ-์ฝ”๋”๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๋‹ค. ํ”„๋ฆฌ-์ฝ”๋”๋Š” ํŠน์ • ์ƒํ™ฉ์— ๋Œ€ํ•˜์—ฌ ์‹ค์ œ ์ธ์ฝ”๋”ฉ์„ ์ˆ˜ํ–‰ํ•˜๊ณ , ๋‹ค๋ฅธ ๋ชจ๋“  ์ƒํ™ฉ์— ๋Œ€ํ•œ ์˜ˆ์ธก ์ธ์ฝ”๋”ฉ ์ •๋ณด๋ฅผ ๊ณ„์‚ฐํ•˜์—ฌ ํฌ์Šคํ„ฐ-์ฝ”๋”์— ์ „๋‹ฌํ•œ๋‹ค. ๊ทธ๋ฆฌ๊ณ  ํฌ์ŠคํŠธ-์ฝ”๋”๋Š” ์ „๋‹ฌ๋ฐ›์€ ์ •๋ณด๋ฅผ ์ด์šฉํ•˜์—ฌ ์‹ค์ œ ๋น„ํŠธ์ŠคํŠธ๋ฆผ์„ ์ƒ์„ฑํ•œ๋‹ค.์ œ 1 ์žฅ ์„œ๋ก  1 1.1 ์—ฐ๊ตฌ ๋ฐฐ๊ฒฝ 1 1.2 ์—ฐ๊ตฌ ๋‚ด์šฉ 4 1.3 ๋…ผ๋ฌธ ๊ตฌ์„ฑ 8 ์ œ 2 ์žฅ ์ด์ „ ์—ฐ๊ตฌ 9 2.1 BTC 9 2.1.1 ๊ธฐ๋ณธ BTC ์•Œ๊ณ ๋ฆฌ์ฆ˜ 9 2.1.2 ์ปฌ๋Ÿฌ ์ด๋ฏธ์ง€ ์••์ถ•์„ ์œ„ํ•œ BTC ์•Œ๊ณ ๋ฆฌ์ฆ˜ 10 2.2 SPIHT 13 2.2.1 1D SPIHT ์•Œ๊ณ ๋ฆฌ์ฆ˜ 13 2.2.2 SPIHT ํ•˜๋“œ์›จ์–ด 17 2.3 ์˜ˆ์ธก ๊ธฐ๋ฐ˜ ์ฝ”๋”ฉ 19 2.3.1 ์˜ˆ์ธก ๋ฐฉ๋ฒ• 19 2.3.2 VLC 20 2.3.3 ์˜ˆ์ธก ๊ธฐ๋ฐ˜ ์ฝ”๋”ฉ ํ•˜๋“œ์›จ์–ด 22 ์ œ 3 ์žฅ LCD ์˜ค๋ฒ„๋“œ๋ผ์ด๋ธŒ๋ฅผ ์œ„ํ•œ BTC 24 3.1 ์ œ์•ˆ ์•Œ๊ณ ๋ฆฌ์ฆ˜ 24 3.1.1 ๋น„ํŠธ-์ ˆ์•ฝ ๋ฐฉ๋ฒ• 25 3.1.2 ๋ธ”๋ก ํฌ๊ธฐ ์„ ํƒ ๋ฐฉ๋ฒ• 29 3.1.3 ์•Œ๊ณ ๋ฆฌ์ฆ˜ ์š”์•ฝ 31 3.2 ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ 33 3.2.1 ํ”„๋ ˆ์ž„ ๋ฉ”๋ชจ๋ฆฌ ์ธํ„ฐํŽ˜์ด์Šค 34 3.2.2 ์ธ์ฝ”๋”์™€ ๋””์ฝ”๋”์˜ ๊ตฌ์กฐ 37 3.3 ์‹คํ—˜ ๊ฒฐ๊ณผ 44 3.3.1 ์•Œ๊ณ ๋ฆฌ์ฆ˜ ์„ฑ๋Šฅ 44 3.3.2 ํ•˜๋“œ์›จ์–ด ๊ตฌํ˜„ ๊ฒฐ๊ณผ 49 ์ œ 4 ์žฅ ์ €๋น„์šฉ ๊ทผ์ ‘-๋ฌด์†์‹ค ํ”„๋ ˆ์ž„ ๋ฉ”๋ชจ๋ฆฌ ์••์ถ•์„ ์œ„ํ•œ ๊ณ ์† 1D SPIHT 54 4.1 ์ธ์ฝ”๋” ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ 54 4.1.1 ์˜์กด ๊ด€๊ณ„ ๋ถ„์„ ๋ฐ ์ œ์•ˆํ•˜๋Š” ํŒŒ์ดํ”„๋ผ์ธ ์Šค์ผ€์ฅด 54 4.1.2 ๋ถ„๋ฅ˜ ๋น„ํŠธ ์žฌ๋ฐฐ์น˜ 57 4.2 ๋””์ฝ”๋” ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ 59 4.2.1 ๋น„ํŠธ์ŠคํŠธ๋ฆผ์˜ ์‹œ์ž‘ ์ฃผ์†Œ ๊ณ„์‚ฐ 59 4.2.2 ์ ˆ๋ฐ˜-ํŒจ์Šค ์ฒ˜๋ฆฌ ๋ฐฉ๋ฒ• 63 4.3 ํ•˜๋“œ์›จ์–ด ๊ตฌํ˜„ 65 4.4 ์‹คํ—˜ ๊ฒฐ๊ณผ 73 ์ œ 5 ์žฅ ๊ณ ์ถฉ์‹ค๋„ RGBW ์ปฌ๋Ÿฌ ์ด๋ฏธ์ง€ ์••์ถ•์„ ์œ„ํ•œ ๊ณ ์ • ์••์ถ•๋น„ VLC 81 5.1 ์ œ์•ˆ ์•Œ๊ณ ๋ฆฌ์ฆ˜ 81 5.1.1 RGBW ์ธํ„ฐ-์ปฌ๋Ÿฌ ์—ฐ๊ด€์„ฑ์„ ์ด์šฉํ•œ ์˜ˆ์ธก ๋ฐฉ์‹ 82 5.1.2 ๊ณ ์ • ์••์ถ•๋น„๋ฅผ ์œ„ํ•œ Golomb-Rice ์ฝ”๋”ฉ 85 5.1.3 ์•Œ๊ณ ๋ฆฌ์ฆ˜ ์š”์•ฝ 89 5.2 ํ•˜๋“œ์›จ์–ด ๊ตฌ์กฐ 90 5.2.1 ์ธ์ฝ”๋” ๊ตฌ์กฐ 91 5.2.2 ๋””์ฝ”๋” ๊ตฌ์กฐ 95 5.3 ์‹คํ—˜ ๊ฒฐ๊ณผ 101 5.3.1 ์•Œ๊ณ ๋ฆฌ์ฆ˜ ์‹คํ—˜ ๊ฒฐ๊ณผ 101 5.3.2 ํ•˜๋“œ์›จ์–ด ๊ตฌํ˜„ ๊ฒฐ๊ณผ 107 ์ œ 6 ์žฅ ์••์ถ• ์„ฑ๋Šฅ ๋ฐ ํ•˜๋“œ์›จ์–ด ํฌ๊ธฐ ๋น„๊ต ๋ถ„์„ 113 6.1 ์••์ถ• ์„ฑ๋Šฅ ๋น„๊ต 113 6.2 ํ•˜๋“œ์›จ์–ด ํฌ๊ธฐ ๋น„๊ต 120 ์ œ 7 ์žฅ ๊ฒฐ๋ก  125 ์ฐธ๊ณ ๋ฌธํ—Œ 128 ABSTRACT 135Docto
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