Ensemble of Different Approaches for a Reliable Person Re-identification System

An ensemble of approaches for reliable person re-identification is proposed in this paper. The proposed ensemble is built combining widely used person re-identification systems using different color spaces and some variants of state-of-the-art approaches that are proposed in this paper. Different descriptors are tested, and both texture and color features are extracted from the images; then the different descriptors are compared using different distance measures (e.g., the Euclidean distance, angle, and the Jeffrey distance). To improve performance, a method based on skeleton detection, extracted from the depth map, is also applied when the depth map is available. The proposed ensemble is validated on three widely used datasets (CAVIAR4REID, IAS, and VIPeR), keeping the same parameter set of each approach constant across all tests to avoid overfitting and to demonstrate that the proposed system can be considered a general-purpose person re-identification system. Our experimental results show that the proposed system offers significant improvements over baseline approaches. The source code used for the approaches tested in this paper will be available at https://www.dei.unipd.it/node/2357 and http://robotics.dei.unipd.it/reid/

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

코드화된 미세입자를 이용한 색기반의 동시다발적 현장 진단 플랫폼 개발

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 전기·컴퓨터공학부, 2019. 2. Kwon, Sunghoon.In this dissertation, a multiplex colorimetric diagnosis platform using encoded microparticles is proposed. Multiple target biomolecules can be detected by an office scanner as a concept of point of care tests within low-resource settings. The encoded microparticles guarantee high multiplexing capacity up to millions. Detection using gold nanoparticles in platform was demonstrated with assay results according to the color change of the encoded microparticles. Realizing scanner-based multiplex assay, this platforms novelty lies in fabrication of the encoded particles with two materials and introduction of a signal enhancement step to the multiplex bead-based assay using deposition of gold for higher sensitivity. The encoded microparticles, in which the engraved codes indicate the types of target molecules, are prepared to capture target. The design of the particles including the size and the materials were determined, to analyze the assay results with images taken by scanners. Also, the high-throughput fabrication methods have been developed to guarantee that more than 1000 particles can be fabricated in less than 3 minutes. The encoded particles with a single code are coated by silica and chemically conjugated to one type of capture molecules. This pairing guarantees the code to indicate the type of target molecules in multiplexing assay. The encoded microparticles targeting various molecules are pooled and reacted to samples with target molecules. After capturing targets on the multiple types of encoded particles, the particles conjugated with targets react with detection molecules. The detection molecules include gold nanoparticles to change the levels of target molecules into color signals. If the signal is too weak, a signal enhancement step is introduced using gold deposition to the seed gold nanoparticles with targets. After the whole colorimetric assay, the reacted particles are imaged using an office scanner, from which the code and the assay results are analyzed using image processing. The size of the microparticles was considered according to the proper resolution of the scanners. To be applied to various situations, two types of particles have been developed and utilized. 900μm particles with 2.5 million kinds of character codes and 300μm particles with 70-256 kinds of binary codes are developed to be scanned with 1200 and 4800 dpi respectively. As a proof of concept to show a wide range of applications, proteins and genes are detected. Using 4-plex assay, multiple sclerosis autoimmune disease patients are classified from healthy people with p<0.0001 in an unpaired t-test. Using 3-plex assay, bacterial meningitis genes are detected within 1000 molecules. This scanner-based assay platform can expand the clinical impacts of the multiplex assay. This platform can be applied to various circumstances where high-resource settings have not been set. With operators and scanners, the platform can be applied to multiplex assay in high multiplexing capacity and high throughput.본 학위 논문에서는 동시다발적으로 단백질이나 유전물질을 색변화를 통해 진단할 수 있는 플랫폼을 개발하였다. 본 플랫폼은 최종적으로 오피스 스캐너로 분석할 수 있기에 고가의 장비 없이 환자와 보다 가까운 곳에서 활용될 수 있는 기술이다. 코드화된 미세입자를 통해 한 샘플에서 동시에 여러 가지 진단을 가능하게 하였으며, 금 나노입자를 통해 분석 결과가 색 변화로 나타나 스캐너로 검출할 수 있도록 하였다. 해당 기술을 구현하기 위하여 미세입자를 두 가지 물질로 구성되도록 제작하였고 빠르게 대용량으로 제작하는 기술 역시 개발하였다. 또한 색변화로 적은 양의 물질을 검출할 수 있도록 신호 증폭 기술을 입자 기반 진단 기술에 적용하였다. 본 플랫폼을 개발하기 위해서 우선 표적 생체물질을 잡을 수 있는 코드화된 미세입자를 제작하였다. 스캐너로도 분석에 충분한 이미지를 얻을 수 있도록 크기와 물질 등의 디자인이 고려되었다. 본 미세입자를 3분 이내에 1 000 개 이상 제작할 수 있는 방법 역시 개발하였다. 제작된 코드화된 미세입자는 표적 생체물질만을 붙잡을 수 있도록 실리카 코팅된 후 화학적으로 포획분자가 코드 별로 다르게 부착된다. 여러 물질을 표적하는 코드화된 미세입자들은 함께 섞인 뒤에 표적물질이 있는 샘플과 동시다발적으로 반응한다. 표적물질을 반응 시킨 후에는 표적물질의 존재를 색변화로 나타낼 수 있도록 미세입자에 부착된 표적물질에만 골드 나노파티클이 붙게 된다. 신호가 약한 경우 골드 나노파티클의 크기를 키우는 반응을 통해 신호를 증폭시켜 확인한다. 반응이 모두 끝난 이후 미세입자들은 스캐너로 관측이 되고, 이미지 처리를 통해 코드와 표적물질의 양에 따라 변화된 색변화를 분석한다. 코드는 표적 물질의 종류를 나타내고, 색변화는 표적물질의 존재 정도에 비례하여 나타난다. 미세입자의 크기는 스캐너의 해상도에 직접적으로 연관이 있으므로 1 200 dpi 에서 분석이 가능한 900μm 미세입자와 4 800 dpi 에서 분석이 가능한 300μm 미세입자를 개발하였다. 각 입자는 문자코드를 활용하여 250만 개 이상의 코드를 가질 수 있고, 2진법의 코드를 활용하여 70 에서 256 개의 코드를 가질 수 있도록 개발되었다. 본 플랫폼이 다양한 진단 상황에 적용될 수 있음을 보이기 위하여, 환자 샘플에서 자가면역질환 관련 항체를 검출하는 실험과 적은 양의 박테리아 뇌수막염 관련 유전체를 검출하는 실험을 진행하였다. 4 종류의 동시다발적 분석을 통해 자가면역 질환 환자와 건강한 사람을 비쌍체 t 검정에서 p<0.0001 로 구분할 수 있었으며, 3 종류의 동시다발적 분석을 통해 박테리아 뇌수막염 관련 유전체를 1 000 개까지 검출해낼 수 있었다. 본 플랫폼을 통해 동시다발적 진단 기술의 의료 혜택을 보다 널리 확장시킬 수 있을 것으로 기대된다. 본 플랫폼은 고가의 장비들이 구축되지 않은 환경에서도 스캐너만 있다면 구현될 수 있으며 많은 수의 표적 물질을 동시에 확인할 수 있고 병렬적으로 많은 샘플을 진단할 수 있도록 개발되었기 때문이다.Table of Contents ABSTRACT I MULTIPLEX COLORIMETRIC DIAGNOSIS FOR POINT OF CARE TEST USING ENCODED MICROPARTICLE I TABLE OF CONTENTS IV LIST OF TABLES VIII LIST OF FIGURES IX CHAPTER 1. INTRODUCTION １ 1.1. Multiplex point of care test ２ 1.1.1. Multiplex assay for diagnosis of patients ２ 1.1.2. Needs of multiplex point of care test near to patients ５ 1.2. Main Concept: Multiplex colorimetric assay platform with encoded microparticle ８ 1.2.1. Multiplex colorimetric assay platform with encoded microparticle ９ 1.2.2. Advantages of scanner as widely spread detecting device １０ 1.2.3. Core technology of platform １２ 1.3. Outline of dissertation １８ CHAPTER 2. BACKGROUND １９ 2.1. Process of multiplex assay ２０ 2.2. Previous multiplex point of care technology ２１ 2.2.1. Technology for multiplex point of care test technology ２２ 2.2.2. Positioning of previous technology for multiplex assay ２９ 2.3. Commercialized multiplex assay devices for point of care test ３１ 2.3.1. Pros and cons of conventional automated machines for multiplex point of care test ３８ 2.4. Previous research in the group ４３ CHAPTER 3. PLATFORM DEVELOPMENT ４６ 3.1. Preparing process of encoded microparticle conjugated with capture molecule ４７ 3.1.1. Particle design considerations for scanner-based detection ４９ 3.1.2. Fabrication process of dual-functional encoded particle ５２ 3.1.3. Strategy to fabricate dual-functional sequentially with fixing polymers at the same position. ５５ 3.1.4. High-throughput fabrication method ５７ 3.1.5. Process of chemically conjugating capture molecules on surface of encoded particles ６４ 3.2. Process of massively parallel multiplex colorimetric assay ６７ 3.3. Optimization of imaging process with office scanner ６８ 3.3.1. Optimization of imaging plate ６９ 3.3.2. Optimization of resolution of scanning ７０ 3.4. Data analyzing process ７１ 3.4.1. Particle detection and alignment process ７２ 3.4.2. Algorithm for decoding particles and analyzing results of colorimetric assay from scanned images ７４ CHAPTER 4. PLATFORM VALIDATION WITH APPLICATION: ANTIBODY FROM AUTOIMMUNE DISEASE AND GENE FROM BACTERIAL MENINGITIS ７８ 4.1. Validation for immunoassay with autoimmune disease samples ７９ 4.2. Validation for genotyping with bacterial meningitis target ８７ CHAPTER 5. CONCLUSION AND DISCUSSION ９１ 5.1. Summary of dissertation ９２ 5.2. Comparison with previous technology ９４ 5.3. Limit of platform ９７ 5.4. Future work ９９ BIBLIOGRAPHY １００ 국문 초록 １１０Docto

Engineering data compendium. Human perception and performance. User's guide

The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

Vibrational Spectroscopy as a Tool for Studying Drug-Cell Interaction: Could High Throughput Vibrational Spectroscopic Screening Improve Drug Development

Vibrational spectroscopy is currently widely explored as a tool in biomedical applications. An area at the forefront of this field is the use of vibrational spectroscopy for disease diagnosis, ultimately aiming towards spectral pathology. However, while this field shows promising results, moving this technique into the clinic faces the challenges of widespread clinical trials and legislative approval. While spectral pathology has received a lot of attention, there are many other biomedical applications of vibrational spectroscopy, which could potentially be translated to applications with greater ease. A particularly promising application is the use of vibrational spectroscopic techniques to study the interaction of drugs with cells. Many studies have demonstrated the ability to detect biochemical changes in cells in response to drug application, using both infrared and Raman spectroscopy. This has shown potential for use in high throughput screening (HTS) applications, for screening of efficacy and mode of action of potential drug candidates, to speed up the drug discovery process. HTS is still a relatively new and growing area of research and, therefore, there is more potential for new techniques to move into and shape this field. Vibrational spectroscopic techniques come with many benefits over the techniques used currently in HTS, primarily based on fluorescence assays to detect specific binding interactions or phenotypes. They are label free, and an infrared or Raman spectrum provides a wealth of biochemical information, and therefore could reveal not only information about a specific interaction, but about how the overall biochemistry of a cell changes in response to application of a drug candidate. Therefore, drug mode of action could be elucidated. This review will investigate the potential for vibrational spectroscopy, particularly FTIR and Raman spectroscopy, to benefit the field of HTS and improve the drug development process. In addition to FTIR and Raman spectroscopy, surface enhanced Raman spectroscopy (SERS), coherent anti-Stokes Raman spectroscopy (CARS) and stimulated Raman spectroscopy (SRS), will be investigated as an alternative tool in the HTS process

Robust Biosensors for Healthcare Applications: from High-Content Screening to Point-of-Care Testing

Efficient detection of proteins, mammalian cells, microorganisms and other biological systems in complex mixture is essential in disease diagnosis and environmental health. Therefore, technological platforms that provide sensors of high sensitivity, selectivity and stability are greatly desired. Recently, the ‘chemical-nose’ sensing approach has proved to be an effective strategy for profiling bio-relevant targets in complex mixtures. Detecting analytes in complex mixture is a challenge that conventional specificity-based sensors are still trying to solve due to the requirement of prior knowledge of the analyte, which is unknown in many cases. This thesis focuses on how to develop simple and robust chemical-nose sensors for complex mixtures using supramolecular interactions between nanoparticles, fluorescent proteins, enzymes, and fluorescent polymers. We have successfully developed effective sensors for many healthcare applications including chemotherapeutic drug profiling, cancer diagnostics, environmental toxicity and bacterial detection. Throughout this dissertation, there is an emphasis on moving from high-content screening to point-of-care testing, especially in cancer diagnostics. Overall, the chemical-nose sensors provide a simple generic tool for bio-relevant analyte profiling, avoiding additional processing steps prior to screening as seen in traditional methods. More importantly, chemical-nose sensors hold great promise for addressing the needs in personalized screening of disease states and environmental toxicology

The Monitoring and Assessment Plan (MAP) Greater Everglades Wetlands Module- Landscape Pattern- Ridge, Slough, and Tree Island Mosaics: Year 1 Annual Report

In the current managed Everglades system, the pre-drainage, patterned mosaic of sawgrass ridges, sloughs and tree islands has been substantially altered or reduced largely as a result of human alterations to historic ecological and hydrological processes that sustained landscape patterns. The pre-compartmentalization ridge and slough landscape was a mosaic of sloughs, elongated sawgrass ridges (50-200m wide), and tree islands. The ridges and sloughs and tree islands were elongated in the direction of the water flow, with roughly equal area of ridge and slough. Over the past decades, the ridge-slough topographic relief and spatial patterning have degraded in many areas of the Everglades. Nutrient enriched areas have become dominated by Typha with little topographic relief; areas of reduced flow have lost the elongated ridge-slough topography; and ponded areas with excessively long hydroperiods have experienced a decline in ridge prevalence and shape, and in the number of tree islands (Sklar et al. 2004, Ogden 2005)

Recent Developments in Video Surveillance

With surveillance cameras installed everywhere and continuously streaming thousands of hours of video, how can that huge amount of data be analyzed or even be useful? Is it possible to search those countless hours of videos for subjects or events of interest? Shouldn’t the presence of a car stopped at a railroad crossing trigger an alarm system to prevent a potential accident? In the chapters selected for this book, experts in video surveillance provide answers to these questions and other interesting problems, skillfully blending research experience with practical real life applications. Academic researchers will find a reliable compilation of relevant literature in addition to pointers to current advances in the field. Industry practitioners will find useful hints about state-of-the-art applications. The book also provides directions for open problems where further advances can be pursued

Evolution of correlated complexity in the radically different courtship signals of birds-of-paradise

This is the author accepted manuscript. The final version is available from Public Library of Science (PLoS) via the DOI in this record.Data accessibility: Data for primary analyses are included in S1 Data file.Ornaments used in courtship often vary wildly among species, reflecting the evolutionary interplay between mate preference functions and the constraints imposed by natural selection. Consequently, understanding the evolutionary dynamics responsible for ornament diversification has been a longstanding challenge in evolutionary biology. However, comparing radically different ornaments across species, as well as different classes of ornaments within species, is a profound challenge to understanding diversification of sexual signals. Using novel methods and a unique natural history dataset, we explore evolutionary patterns of ornament evolution in a group – the birds-of-paradise – exhibiting dramatic phenotypic diversification widely assumed to be driven by sexual selection. Rather than the trade-off between ornament types originally envisioned by Darwin and Wallace, we found positive correlations among cross-modal (visual/acoustic) signals indicating functional integration of ornamental traits into a composite unit – the courtship phenotype. Furthermore, given the broad theoretical and empirical support for the idea that systemic robustness – functional overlap and interdependency – promotes evolutionary innovation, we posit that birds-of-paradise have radiated extensively through ornamental phenotype space as a consequence of the robustness in the courtship phenotype that we document at a phylogenetic scale. We suggest that the degree of robustness in courtship phenotypes among taxa can provide new insights into the relative influence of sexual and natural selection on phenotypic radiations