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    High-speed Video from Asynchronous Camera Array

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    This paper presents a method for capturing high-speed video using an asynchronous camera array. Our method sequentially fires each sensor in a camera array with a small time offset and assembles captured frames into a high-speed video according to the time stamps. The resulting video, however, suffers from parallax jittering caused by the viewpoint difference among sensors in the camera array. To address this problem, we develop a dedicated novel view synthesis algorithm that transforms the video frames as if they were captured by a single reference sensor. Specifically, for any frame from a non-reference sensor, we find the two temporally neighboring frames captured by the reference sensor. Using these three frames, we render a new frame with the same time stamp as the non-reference frame but from the viewpoint of the reference sensor. Specifically, we segment these frames into super-pixels and then apply local content-preserving warping to warp them to form the new frame. We employ a multi-label Markov Random Field method to blend these warped frames. Our experiments show that our method can produce high-quality and high-speed video of a wide variety of scenes with large parallax, scene dynamics, and camera motion and outperforms several baseline and state-of-the-art approaches.Comment: 10 pages, 82 figures, Published at IEEE WACV 201

    ์น˜๋ฃŒ์ œ ์ „๋‹ฌ์„ ์œ„ํ•œ ์ฃผ์‚ฌ๊ฐ€๋Šฅํ•œ ๋งˆ์ดํฌ๋กœ ํฌ๋ผ์ด์˜ค๊ฒ” ์‹œ์Šคํ…œ ๊ฐœ๋ฐœ

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    ํ•™์œ„๋…ผ๋ฌธ (์„์‚ฌ) -- ์„œ์šธ๋Œ€ํ•™๊ต ๋Œ€ํ•™์› : ๊ณต๊ณผ๋Œ€ํ•™ ํ˜‘๋™๊ณผ์ • ๋ฐ”์ด์˜ค์—”์ง€๋‹ˆ์–ด๋ง์ „๊ณต, 2020. 8. ํ™ฉ์„์—ฐ.Cryogels have a large porous structure, and they can be tailored to have shape-memory ability and injectability. In addition, cells or growth factors can be loaded within the cryogel and show sustained release behavior. Because of these characteristics, the cryogels have been widely used for tissue-engineering applications. However, bulky cryogel cannot pass the narrow needle syringe and fill the irregular shape defect perfectly. Herein, we established an injectable cryogel system for delivering cells or therapeutic agents. It displayed smoothly injectable characteristics that exhibited printability and void-filling ability. In chapter one, we fabricated injectable cryogel microparticles (CMP) via simply pulverizing. To prepare the CMP, we used both methacrylated chitosan (Chi-MA) and methacrylated chondroitin sulfate (CS-MA) and cross-linked them under -20โ„ƒ conditions. Also, we loaded the recombinant human-vascular endothelial growth factor (rhVEGF) into the CMP (V-CMP), and the sustained release behavior could be obtained. Finally, when the V-CMP were injected into mice hindlimb ischemia model, the enhanced neovascularization and effective tissue necrosis prevention were observed. In chapter two, we also fabricated injectable cryogel microsphere via microfluidic and emulsification. The microspheres consist of methacrylated gelatin (Gel-MA) and methacrylated hyaluronic acid (HA-MA), and they had narrow size distribution. In addition, we confirmed that the cells could infiltrate into the cryogel microspheres and that the microspheres provided the cells with favorable environment.ํฌ๋ผ์ด์˜ค๊ฒ”์€ ํฐ ๊ธฐ๊ณต๊ตฌ์กฐ๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ์œผ๋ฉฐ, ํ˜•์ƒ๊ธฐ์–ต๋Šฅ๊ณผ ์ฃผ์ž…๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ํŠน์ง•์ด ์žˆ๋‹ค. ๋˜ํ•œ, ์„ธํฌ๋‚˜ ์„ฑ์žฅ์ธ์ž๋“ค์ด ํฌ๋ผ์ด์˜ค๊ฒ” ๋‚ด๋ถ€์— ๋‹ด์ง€๋˜์–ด ์„œ๋ฐฉ์ถœ ์–‘์ƒ์„ ๋„๊ธฐ๋„ ํ•œ๋‹ค. ์ด๋Ÿฌํ•œ ํŠน์ง•๋“ค ๋•๋ถ„์—, ํฌ๋ผ์ด์˜ค๊ฒ”์€ ์กฐ์ง๊ณตํ•™์ ์œผ๋กœ ๋„๋ฆฌ ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜, ๋ถ€ํ”ผ๊ฐ€ ํฐ ํฌ๋ผ์ด์˜ค๊ฒ”์€ ์ž‘์€ ์ฃผ์‚ฌ๋ฐ”๋Š˜๊ตฌ๋ฉ์„ ํ†ต๊ณผํ•˜๊ธฐ ํž˜๋“ค๊ณ , ๋ถˆ๊ทœ์น™์  ๋ชจ์–‘์˜ ๋ณ‘๋ณ€ ๋ถ€์œ„๋ฅผ ์™„์ „ํžˆ ์ฑ„์šธ ์ˆ˜ ์—†๋‹ค. ๋”ฐ๋ผ์„œ ์œ„ ๋…ผ๋ฌธ์—์„œ ์šฐ๋ฆฌ๋Š” ์„ธํฌ๋‚˜ ์น˜๋ฃŒ์ œ ์ „๋‹ฌ์„ ํ•  ์ˆ˜ ์žˆ๋Š” ์ฃผ์‚ฌ๊ฐ€๋Šฅ ํฌ๋ผ์ด์˜ค๊ฒ”์‹œ์Šคํ…œ์„ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ์ด๊ฒƒ์€ ๋ถ€๋“œ๋Ÿฝ๊ฒŒ ์ฃผ์ž…๋˜๊ณ  ์‚ฌ์ถœ ์„ฑํ˜•๋Šฅ๊ณผ void-filling ํŠน์„ฑ์„ ๋ˆ๋‹ค. ์ฒซ๋ฒˆ์งธ ์ฑ•ํ„ฐ์—์„œ๋Š”, ์ฃผ์ž…์‹ ํฌ๋ผ์ด์˜ค๊ฒ” ๋งˆ์ดํฌ๋กœ์ž…์ž(CMP)๋ฅผ pulverizing์„ ํ†ตํ•ด ์†์‰ฝ๊ฒŒ ์ œ์ž‘ํ•˜์˜€๋‹ค. CMP๋ฅผ ์ œ์ž‘ํ•˜๊ธฐ ์œ„ํ•ด ์šฐ๋ฆฌ๋Š” ๋ฉ”ํƒ€ํฌ๋ฆด๋ ˆ์ดํŠธํ™” ํ‚คํ† ์‚ฐ๊ณผ ๋ฉ”ํƒ€ํฌ๋ฆด๋ ˆ์ดํŠธ์™€ ํ™ฉ์‚ฐ์ฝ˜๋“œ๋กœ์ดํ‹ด์„ ์‚ฌ์šฉํ•˜์—ฌ ์˜ํ•˜ 20๋„์”จ ์กฐ๊ฑด์—์„œ ๊ฐ€๊ต์‹œ์ผฐ๋‹ค. ๋˜ํ•œ ํ˜ˆ๊ด€์ƒ์„ฑ์ธ์ž๋ฅผ CMP ์— ๋‹ด์ง€ํ•˜์—ฌ ์„œ๋ฐฉ์ถœ์–‘์ƒ์„ ๋„์—ˆ๋‹ค. ๋งˆ์ง€๋ง‰์œผ๋กœ, ํ˜ˆ๊ด€์ƒ์„ฑ์ธ์ž๊ฐ€ ๋‹ด์ง€๋œ ํฌ๋ผ์ด์˜ค๊ฒ”์„ ํ•˜์ง€ํ—ˆํ˜ˆ ๋งˆ์šฐ์Šค๋ชจ๋ธ์— ๊ทผ์œก์ฃผ์‚ฌํ•˜์—ฌ ์‹ ์ƒํ˜ˆ๊ด€์ด ์ด‰์ง„๋˜๊ณ , ๊ดด์‚ฌ๋ฅผ ์–ต์ œํ•˜์—ฌ ์กฐ์ง์žฌ์ƒ์ด ๋˜๋Š” ๊ฒƒ ์—ญ์‹œ ํ™•์ธํ•˜์˜€๋‹ค. ๋‘๋ฒˆ์งธ ์ฑ•ํ„ฐ์—์„œ๋Š”, ์ฃผ์ž…์‹ ํฌ๋ผ์ด์˜ค๊ฒ” ๋งˆ์ดํฌ๋กœ์Šคํ”ผ์–ด๋ฅผ ๋ฏธ์„ธ์œ ์ฒด์นฉ๊ณผ ์—๋ฉ€์ ผ๊ธฐ๋ฒ•์„ ํ†ตํ•ด ์ œ์ž‘ํ•˜์˜€๋‹ค. ๋ฉ”ํƒ€ํฌ๋ฆด๋ ˆ์ดํŠธํ™”๋œ ์ ค๋ผํ‹ด๊ณผ ๋ฉ”ํƒ€ํฌ๋ฆด๋ ˆ์ดํŠธํ™”๋œ ํžˆ์•Œ๋ฃจ๋ก ์‚ฐ์„ ์ด์šฉํ•˜์—ฌ ๋งˆ์ดํฌ๋กœ์Šคํ”ผ์–ด๋ฅผ ์ œ์ž‘ํ•˜์˜€๊ณ , ์ด๋Š” ๋ณด๋‹ค ๊ท ์ผํ•œ ์ƒํƒœ์˜ ๋ฏธ์„ธ์ž…์žํ˜•ํƒœ๋ฅผ ๋ณด์˜€๋‹ค. ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ, ์„ธํฌ๊ฐ€ ํฌ๋ผ์ด์˜ค๊ฒ” ๋งˆ์ดํฌ๋กœ์Šคํ”ผ์–ด ๋‚ด๋ถ€๋กœ ์นจํˆฌํ•˜๊ณ  ์™ธ๋ถ€์˜ ์ถฉ๊ฒฉ์œผ๋กœ๋ถ€ํ„ฐ ๋ณดํ˜ธ๋˜์–ด ํฌ๋ผ์ด์˜ค๊ฒ”์ด ์„ธํฌ๋ฅผ ์ „๋‹ฌํ•˜๊ธฐ ์ ํ•ฉํ•œ ํ™˜๊ฒฝ์ž„์„ ํ™•์ธํ•˜์˜€๋‹ค.ABSTRACT i Development of Injectable Microcryogel System for Delivering Therapeutic Agents i Table of Contents iii List of figures v CHAPTER ONE: Enhanced Neovascularization Using Injectable and rhVEGF-Releasing Microparticles 1 1.1 Introduction 1 1.2 Experimental section 5 1.2.1 Synthesis of methacrylated biopolymers 5 1.2.2 Fabrication of cryogels 6 1.2.3 Characterization of cryogels 6 1.2.4 Fabrication of cryogel microparticle (CMP) 7 1.2.5 Rheological properties and injectability of the CMP 8 1.2.6 Release kinetic analysis 9 1.2.7 Antibacterial test 9 1.2.8 In vitro biocompatibility and cell proliferation 10 1.2.9 In vivo hindlimb ischemia model and cryogel injection 11 1.2.10 Histological analysis 12 1.2.11 Statistical analysis 12 1.3 Results & Discussion 13 1.3.1 Synthesis of methacrylated biopolymers 13 1.3.2 Fabrication and characterization of the Chi-MA/CS-MA/PEGDA cryogels 15 1.3.3 Preparation of the cryogel microparticle (CMP) and the injectability 19 1.3.4 Sustained rhVEGF-release behavior 23 1.3.6 The effects of released rhVEGF on cell behavior 27 1.3.7 Intramuscular injection of the CMP for treating the mice hindlimb ischemia in vivo 29 1.4 Conclusion 34 CHAPTER TWO: Injectable Cryogel Microsphere for Cell Delivery. 35 2.1 Introduction 35 2.2 Experimental section 40 2.2.1 Synthesis of methacrylated biopolymers 40 2.2.2 Fabrication of cryogel 41 2.2.3 Swelling ratio and rheological property of cryogel 41 2.2.4 Preparation of cryogel microspheres 42 2.2.5 Cell proliferation and viability 43 2.3 Results & Discussion 44 2.3.1 Synthesis of methacrylated biopolymers 44 2.3.2 Characterization of cryogel 46 2.3.3 Preparation of cryogel microsphere 50 2.3.4 In vitro, cell viability and protection. 52 2.4 Conclusion 54 References 55 ๊ตญ๋ฌธ์ดˆ๋ก(์š”์•ฝ) 61Maste

    Shape characteristics of the aggregates formed by amphiphilic stars in water: dissipative particle dynamics study

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    We study the effect of the molecular architecture of amphiphilic star polymers on the shape of aggregates they form in water. Both solute and solvent are considered at a coarse-grained level by means of dissipative particle dynamics simulations. Four different molecular architectures are considered: the miktoarm star, two different diblock stars and a group of linear diblock copolymers, all of the same composition and molecular weight. Aggregation is started from a closely packed bunch of NaN_{\text a} molecules immersed into water. In most cases, a single aggregate is observed as a result of equilibration, and its shape characteristics are studied depending on the aggregation number NaN_{\text a}. Four types of aggregate shape are observed: spherical, rod-like and disc-like micelle and a spherical vesicle. We estimate "phase boundaries" between these shapes depending on the molecular architecture. Sharp transitions between aspherical micelle and a vesicle are found in most cases. The pretransition region shows large amplitude oscillations of the shape characteristics with the oscillation frequency strongly dependent on the molecular architecture.Comment: 10 pages, 7 figure

    Area fill synthesis for uniform layout density

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    Stepping Stones to Inductive Synthesis of Low-Level Looping Programs

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    Inductive program synthesis, from input/output examples, can provide an opportunity to automatically create programs from scratch without presupposing the algorithmic form of the solution. For induction of general programs with loops (as opposed to loop-free programs, or synthesis for domain-specific languages), the state of the art is at the level of introductory programming assignments. Most problems that require algorithmic subtlety, such as fast sorting, have remained out of reach without the benefit of significant problem-specific background knowledge. A key challenge is to identify cues that are available to guide search towards correct looping programs. We present MAKESPEARE, a simple delayed-acceptance hillclimbing method that synthesizes low-level looping programs from input/output examples. During search, delayed acceptance bypasses small gains to identify significantly-improved stepping stone programs that tend to generalize and enable further progress. The method performs well on a set of established benchmarks, and succeeds on the previously unsolved "Collatz Numbers" program synthesis problem. Additional benchmarks include the problem of rapidly sorting integer arrays, in which we observe the emergence of comb sort (a Shell sort variant that is empirically fast). MAKESPEARE has also synthesized a record-setting program on one of the puzzles from the TIS-100 assembly language programming game.Comment: AAAI 201
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