189 research outputs found
Highly efficient macrocycle and cage formation via hindered urea chemistry
No full textU of I OnlyDynamic covalent chemistry (DCC) is a powerful tool that enables the synthesis of novel macrocycles, molecular cages, knots and frameworks, as well as the development of dynamic polymeric materials with unique properties. Hindered urea bond (HUB), a newly developed DCC, has found applications in dynamic materials designs such as self-healing, malleable, shape-memory or environmentally-adaptive materials. However, despite of the intensive research, study of this new, facile dynamic chemistry is still in its infancy. The potential of HUB in the formation of discrete structures in small molecular level is largely overlooked and not demonstrated. What’s more, a turning-off mechanism for HUB was not found which can severally limit the applications of HUB-based materials. Here we report the discovery of acid-assisted de-tert-butylation reaction that can instantly “turn off” the dynamicity of HUB, leading to improved chemical stabilities and mechanical properties of HUB-containing materials. We also demonstrated the use of dynamic HUB for the construction of urea macrocycles with very high efficiency. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C=O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. Building upon the macrocyclization mechanism, we demonstrated that HUB can function as efficient cyclization enabling motif for cyclic peptides. Beyond macrocycles, HUB was also utilized to efficiently construct a series of structures with different topologies as well as urea cages, which were demonstrated to be able to separate important petrochemicals such as pyridine/toluene and benzene/cyclohexane.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-08-01The student, Yingfeng Yang, accepted the attached license on 2021-07-09 at 04:30.The student, Yingfeng Yang, submitted this Dissertation for approval on 2021-07-09 at 05:03.This Dissertation was approved for publication on 2021-07-14 at 15:30.DSpace SAF Submission Ingestion Package generated from Vireo submission #16816 on 2022-01-12 at 12:54:04Made available in DSpace on 2022-01-12T22:35:07Z (GMT). No. of bitstreams: 2
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Research on Three Dimensional Reconstruction of the Ancient Building Based on Images
No full textInternational audienceThree dimensional reconstruction of ancient building using the theory of computer vision is one of the main ways to protect, promote and disseminate the value of ancient building. Due to there exist some shortcomings in the current digitization process of ancient building, such as large-scale scene reconstruction algorithm is complex and the accuracy is low, we present a three dimensional reconstruction approach to point cloud of ancient building based on multiple view images. The proposed approach uses an ordinary digital camera to capture multiple images of the ancient building to be reconstructed, takes advantage of affine decomposition principle to calculate the depth information of SIFT feature point on the ancient building with no damage and convenient operation. Through three dimensional reconstructing of the shape of the Tengwang Pavilion lying in Nanchang city, one of the three famous pavilions in the south of Yangtze River in China, to verify the validity of the proposed approach
John-Stromberg Inequality for Certain Anisotropic BMO Spaces
No full textIn this paper, we establish the John-Stromberg inequality in certain anisotropic BMO spaces and apply the inequality to anisotropic Holder continuous function spaces. To achieve this goal, we define the median value, BMO space and sharp maximal function first. Secondly we constructed a family of continuously expanding rectangles and give a Calderon-Zygmund type decomposition. By using these tools, we establish the John-Stromberg inequality. Finally, an application to anisotropic Holder continuous function spaces is presented
Research on a three-dimensional reconstruction method based on the feature matching algorithm of a scale-invariant feature transform
No full textAutomated Personnel Activities Observation in the Catheterization Laboratory
No full textThis thesis presents a method for personnel activities observation, i.e., 3D human pose estimation and tracking, in a Catheterization Laboratory(Cath Lab). We mount five cameras from different angles in the Cath Lab, where surgeons and assistants are in similar clothes while doing surgery. Accurate 3D human pose estimation is the cornerstone of our method. Most previous 3D pose estimation methods train their models directly on a 3D pose dataset. However, these methods are not suitable for our task: 1) We do not have enough 3D pose data for training because of privacy issues and specificity 2) The model needs to be retrained in different operating rooms or the camera calibration changed. To solve these problems, we decompose the 3D human pose estimation task into two stages, avoiding the need for large amounts of 3D pose data and retraining. In the first stage, we apply YOLOX and HRNet for 2D human detection and 2D pose estimation. Simultaneously, the 2D object tracking network Bytetrack tracks person identities based on detection results. Then we use a matching algorithm to match the corresponding 2D poses from multiple views and reconstruct 3D poses. Given 3D poses and tracking identities, we at last introduce a hybrid method tracking algorithm. By feeding 2D tracking results into the matching and tracking algorithm, we increase the accuracy of the result in a scene where people are wearing similar clothes. We fine-tune and test our method with an operating room dataset. Finally, we validate the method on data from the Cath Lab.Electrical Engineerin
Optimization of manufacturing systems using the Internet of Things /
No full textOptimization of Manufacturing Systems Using the Internet of Things extends the IoT (Internet of Things) into the manufacturing field to develop an IoMT (Internet of Manufacturing Things) architecture with real-time traceability, visibility, and interoperability in production planning, execution, and control. This book is essential reading for anyone interested in the optimization and control of an intelligent manufacturing system. As modern manufacturing shop-floors can create bottlenecks in the capturing and collection of real-time field information, and because paper-based manual systems are time-consuming and prone to errors, this book helps readers understand how to alleviate these issues, assisting them in their decision-making on shop-floors.Online resource; title from title page (viewed January 4, 2017).Includes bibliographical references and index.Cover; Title page; Copyright page; Contents; Preface; Chapter 1 -- Introduction; 1.1 -- The concept of IoT; 1.2 -- Existing manufacturing paradigms and their limitations; 1.2.1 -- Agile Manufacturing; 1.2.2 -- Networked Manufacturing; 1.2.3 -- Reconfigurable Manufacturing Systems; 1.2.3.1 -- Modularity; 1.2.3.2 -- Integrability; 1.2.3.3 -- Customization; 1.2.3.4 -- Convertibility; 1.2.3.5 -- Scalability; 1.2.3.6 -- Diagnosability; 1.2.4 -- Product-Service System/Industrial Product-Service Systems; 1.2.5 -- Manufacturing Grid; 1.2.6 -- Cloud Manufacturing; 1.2.7 -- Limitations.1.3 -- Applications of IoT in manufacturing system1.4 -- The conception of IoT-MS; 1.5 -- Key features and limitations of IoT-MS; 1.6 -- Organization of the book; References; Chapter 2 -- Overview of IoT-Enabled Manufacturing System; 2.1 -- Introduction; 2.2 -- Related work; 2.2.1 -- Advanced Manufacturing Paradigms and Technologies; 2.2.2 -- Manufacturing Information Standard and Share and Integration Method; 2.3 -- Overall architecture of IoT-MS; 2.4 -- Integration framework of real-time manufacturing information; 2.4.1 -- Framework of Real-Time Manufacturing Information Sharing and Integration.2.4.2 -- Real-Time Manufacturing Data Processing, Sharing, and Exchanging Service2.5 -- The worklogic of IoT-MS; 2.6 -- Description of the core technologies of IoT-MS; References; Chapter 3 -- Real-Time and Multisource Manufacturing Information Sensing System; 3.1 -- Introduction; 3.2 -- Related works; 3.2.1 -- Real-Time Manufacturing Data Capturing; 3.2.2 -- Sensor Management; 3.2.3 -- Manufacturing Information Processing and Sharing; 3.3 -- Overall architecture of real-time and€multisource RMMISS; 3.3.1 -- Deployment of Multiple Sensors; 3.3.2 -- Multiple Sensors Manager.3.3.3 -- Multisource Manufacturing Information Processing and€Sharing3.4 -- Deployment of multisensors; 3.4.1 -- Description of Multisource Manufacturing Information; 3.4.2 -- Multiple Sensors Selection; 3.5 -- Multiple sensors manager; 3.6 -- Multisource manufacturing information capturing and sharing; 3.6.1 -- Data Preprocessing; 3.6.2 -- Information Encapsulation; 3.6.3 -- Manufacturing Information Sharing; 3.7 -- Case study; 3.7.1 -- Hardware Device; 3.7.2 -- Software System; References; Chapter 4 -- IoT-Enabled Smart Assembly Station; 4.1 -- Introduction; 4.2 -- Related works.4.2.1 -- RFID-Based Applications in Assembly Line4.2.2 -- Assistant Services for Assembly Line; 4.3 -- Overall architecture of IoT-enabled smart assembly station; 4.4 -- Real-time status monitoring; 4.5 -- Real-time production guiding; 4.6 -- Real-time production data sharing; 4.7 -- Real-time production requeuing; References; Chapter 5 -- Cloud Computing-Based Manufacturing Resources Configuration Method; 5.1 -- Introduction; 5.2 -- Related works; 5.2.1 -- Cloud Manufacturing; 5.2.2 -- Real-Time Production Information Perception and Capturing; 5.2.3 -- Cloud Service Selection and Composition.5.3 -- Overall architecture of manufacturing resources configuration method.Optimization of Manufacturing Systems Using the Internet of Things extends the IoT (Internet of Things) into the manufacturing field to develop an IoMT (Internet of Manufacturing Things) architecture with real-time traceability, visibility, and interoperability in production planning, execution, and control. This book is essential reading for anyone interested in the optimization and control of an intelligent manufacturing system. As modern manufacturing shop-floors can create bottlenecks in the capturing and collection of real-time field information, and because paper-based manual systems are time-consuming and prone to errors, this book helps readers understand how to alleviate these issues, assisting them in their decision-making on shop-floors.Elsevie
A forward collision avoidance algorithm based on driver braking behavior
No full textMeasuring risk is critical for collision avoidance. The paper aims to develop an online risk level classification algorithm for forward collision avoidance systems. Assuming risk levels are reflected by braking profiles, deceleration curves from critical evasive braking events from the Virginia “100-car” database were first extracted. The curves are then clustered into different risk levels based on spectrum clustering, using curve distance and curve changing rate as dissimilarity metrics among deceleration curves. Fuzzy logic rules of safety indicators at critical braking onset for risk classification were then extracted according to the clustered risk levels. The safety indicators include time to collision, time headway, and final relative distance under emergency braking, which characterizes three kinds of uncertain critical conditions respectively. Finally, the obtained fuzzy risk level classification algorithm was tested and compared with other Automatic Emergency Braking (AEB) algorithms under Euro-NCAP testing scenarios in simulation. Results show the proposed algorithm is promising in balancing the objectives of avoiding collision and reducing interference with driver's normal driving compared with other algorithms.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
A Model of Trade and Growth with a Non-traded Service Sector.
No full textThis paper incorporates a nontraded service sector into an otherwise neoclassical model of trade and growth. The author's model can explain why the relative price of services, the expenditure share of services, and the employment share of the service sector all tend to rise with the level of per capita income, which is determined, in the long run, by the ratio of the saving rate to the rate of labor growth and the level of labor-augmenting technical progress. The author also finds that a rich country with a high level of technical progress, ceteris paribus, has comparative advantage in producing capital-intensive goods.
A General Model of Comparative Advantage with Two Factors and a Continuum of Goods.
No full textThis paper develops a general model of comparative advantage with two factors and a continuum of goods, which incorporates the Ricardian and Heckscher-Ohlin-Samuelson models as two special cases and which can illustrate how technology, factor endowments, world income, world prices, and demand preferences influence trade pattern with a single graph. Further, the author has derived an intuitive solution of a unique trade pattern under factor price equalization: countries specialize in goods that use intensively abundant factors and some middle goods in terms of capital intensity are not traded even in the absence of trade barriers. Copyright 1993 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.
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