High-speed Video from Asynchronous Camera Array

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

EXEL : a language for interactive behavioral synthesis

This paper describes a new input language for behavioral synthesis called EXEL. EXEL is a powerful language that permits the user to specify partially designed structures in the language. It employs a mixed graphic/textual user interface to enhance user interactivity. EXEL's design model is comprehensive: it permits specification of synchronous and asynchronous behavior, and allows specification of general timing constraints. A flexible type construct permits the user to define operators and components to be used in the description. Finally, it simplifies compilation by using a small set of constructs for specifying timing and asynchronouos behavior. The compiler for EXEL runs on SUN-3 workstations and is written in C and SUNVIEW

EXTEND-L : an input language for extensible register transfer compilation

This report discusses the model and input language for EXTEND, a synthesis system that permits extensible register transfer synthesis. EXTEND-L fills the need for a language that bridges the gap between existing behavioral input descriptions, which are too abstract, and structural schematics, which cannot capture the high-level behavior. The report first discusses previous work in behavioral synthesis and summarizes the deficiencies of these behavioral specifications. The report then describes the proposed langauge in detail, and concludes with a few examples that show its utility

치료제 전달을 위한 주사가능한 마이크로 크라이오겔 시스템 개발

학위논문 (석사) -- 서울대학교 대학원 : 공과대학 협동과정 바이오엔지니어링전공, 2020. 8. 황석연.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 -20℃ 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.크라이오겔은 큰 기공구조를 가지고 있으며, 형상기억능과 주입가능하다는 특징이 있다. 또한, 세포나 성장인자들이 크라이오겔 내부에 담지되어 서방출 양상을 띄기도 한다. 이러한 특징들 덕분에, 크라이오겔은 조직공학적으로 널리 사용되고 있다. 그러나, 부피가 큰 크라이오겔은 작은 주사바늘구멍을 통과하기 힘들고, 불규칙적 모양의 병변 부위를 완전히 채울 수 없다. 따라서 위 논문에서 우리는 세포나 치료제 전달을 할 수 있는 주사가능 크라이오겔시스템을 개발하였다. 이것은 부드럽게 주입되고 사출 성형능과 void-filling 특성을 띈다. 첫번째 챕터에서는, 주입식 크라이오겔 마이크로입자(CMP)를 pulverizing을 통해 손쉽게 제작하였다. CMP를 제작하기 위해 우리는 메타크릴레이트화 키토산과 메타크릴레이트와 황산콘드로이틴을 사용하여 영하 20도씨 조건에서 가교시켰다. 또한 혈관생성인자를 CMP 에 담지하여 서방출양상을 띄었다. 마지막으로, 혈관생성인자가 담지된 크라이오겔을 하지허혈 마우스모델에 근육주사하여 신생혈관이 촉진되고, 괴사를 억제하여 조직재생이 되는 것 역시 확인하였다. 두번째 챕터에서는, 주입식 크라이오겔 마이크로스피어를 미세유체칩과 에멀젼기법을 통해 제작하였다. 메타크릴레이트화된 젤라틴과 메타크릴레이트화된 히알루론산을 이용하여 마이크로스피어를 제작하였고, 이는 보다 균일한 상태의 미세입자형태를 보였다. 뿐만 아니라, 세포가 크라이오겔 마이크로스피어 내부로 침투하고 외부의 충격으로부터 보호되어 크라이오겔이 세포를 전달하기 적합한 환경임을 확인하였다.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 국문초록(요약) 61Maste

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

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 $N_{\text a}$ 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 $N_{\text a}$. 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

Stepping Stones to Inductive Synthesis of Low-Level Looping Programs

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