Jie Tang

In questo libro, l'evoluzione microstrutturale di una lega di alluminio rinforzata dall'invecchiamento stata simulata utilizzando modelli di campo di fase micro e continua, rispettivamente su scala atomica e mesoscopica. In primo luogo, la segregazione degli atomi di soluto ai confini del grano (GB), la nucleazione dei cluster e la trasformazione strutturale dei precursori di fase ordinati/disordinati nella lega Al-Cu sono stati simulati utilizzando un campo di fase microscopico. Successivamente, stato sviluppato un modello di campo multifase per descrivere l'evoluzione dei precipitati da invecchiamento nella lega Al-Mg-Si. La crescita di precipitati β'' con il pi forte beneficio di rafforzamento da invecchiamento nella lega Al-Mg-Si stata simulata quantitativamente accoppiando il database CALPHAD (calcolo del diagramma di fase). Gli effetti di diverse frazioni volumetriche, morfologiche e dimensionali delle particelle precipitate sulla crescita dei grani sono stati studiati utilizzando il modello del campo di fase continuo. Infine, stato studiato il meccanismo di deformazione plastica di materiali policristallini con diverse scale sotto l'azione di una forza esterna.

Neste livro, a evolu o microestrutural de uma liga de alum nio refor ada pelo envelhecimento foi simulada utilizando modelos de campo de fase micro e cont nua s escalas at mica e mesosc pica, respetivamente. Em primeiro lugar, a segrega o de tomos de soluto nos limites de gr o (GB), a nuclea o de aglomerados e a transforma o estrutural de precursores de fases precipitadas ordenadas/desordenadas na liga Al-Cu foram simuladas utilizando um campo de fase microsc pico. Em seguida, foi desenvolvido um modelo de campo multif sico para descrever a evolu o dos precipitados de envelhecimento na liga Al-Mg-Si. O crescimento de precipitados β'' com o benef cio mais forte de refor o do envelhecimento na liga Al-Mg-Si foi quantitativamente simulado atrav s do acoplamento da base de dados CALPHAD (c lculo do diagrama de fases). Os efeitos de diferentes frac es de volume, morfologia e tamanho das part culas precipitadas no crescimento do gr o foram investigados utilizando o modelo de campo de fase cont nua. Finalmente, foi estudado o mecanismo de deforma o pl stica de materiais policristalinos com diferentes escalas sob a o de for as externas.

Dans ce livre, l' volution microstructurale d'un alliage d'aluminium renforc par le vieillissement a t simul e en utilisant des mod les de champ de phase micro et continu l' chelle atomique et m soscopique respectivement. Tout d'abord, la s gr gation des atomes de solut la limite du grain, la nucl ation des amas et la transformation structurelle des pr curseurs de phase pr cipit s ordonn s/d sordonn s dans l'alliage Al-Cu ont t simul s l'aide d'un champ de phase microscopique. Ensuite, un mod le de champ multiphasique a t d velopp pour d crire l' volution des pr cipit s de vieillissement dans l'alliage Al-Mg-Si. La croissance des pr cipit s β'' pr sentant le plus fort avantage de renforcement par vieillissement dans l'alliage Al-Mg-Si a t quantitativement simul e en couplant la base de donn es CALPHAD (calcul du diagramme de phase). Les effets des diff rentes fractions de volume, morphologies et tailles des particules pr cipit es sur la croissance des grains ont t tudi s l'aide d'un mod le de champ de phase continu. Enfin, le m canisme de d formation plastique des mat riaux polycristallins diff rentes chelles sous l'effet d'une force externe a t tudi .

In diesem Buch wurde die mikrostrukturelle Entwicklung einer alterungsbest ndigen Aluminiumlegierung mit Hilfe von Mikro- und kontinuierlichen Phasenfeldmodellen auf atomarer bzw. mesoskopischer Ebene simuliert. Zun chst wurden die Entmischung gel ster Atome an der Korngrenze (GB), die Bildung von Clustern und die strukturelle Umwandlung von geordneten/ungeordneten ausgef llten Phasenvorl ufern in einer Al-Cu-Legierung mit Hilfe eines mikroskopischen Phasenfeldes simuliert. Dann wurde ein Mehrphasenfeldmodell entwickelt, um die Entwicklung von Alterungsausscheidungen in einer Al-Mg-Si-Legierung zu beschreiben. Das Wachstum von β''-Ausscheidungen mit dem st rksten Verst rkungseffekt durch Alterung in der Al-Mg-Si-Legierung wurde durch die Kopplung der CALPHAD-Datenbank (Berechnung des Phasendiagramms) quantitativ simuliert. Die Auswirkungen unterschiedlicher Volumenanteile, Morphologie und Gr e der ausgeschiedenen Partikel auf das Kornwachstum wurden mit Hilfe eines kontinuierlichen Phasenfeldmodells untersucht. Schlie lich wurde der Mechanismus der plastischen Verformung von polykristallinen Werkstoffen mit unterschiedlichen Gr enordnungen unter u erer Krafteinwirkung untersucht.

In this book, the microstructural evolution of aging strengthened aluminum alloy was simulated by using micro and continuous phase field models at atomic and mesoscopic scales respectively. Firstly, the segregation of solute atoms at grain boundarie (GB), cluster nucleation and structural transformation of ordered/disordered precipitated phase precursors in Al-Cu alloy were simulated by using microscopic phase field. Then, a multi-phase field model was developed to describe the evolution of aging precipitates in Al-Mg-Si alloy. The growth of β'' precipitates with the strongest aging strengthening benefit in Al-Mg-Si alloy was quantitatively simulated by coupling CALPHAD (calculation of phase diagram) database. The effects of different volume fraction, morphological and size of precipitated particles on grain growth were investigated by using continuous phase field model. Finally, the plastic deformation mechanism of polycrystalline materials with different scales under external force is studied.

The recent development of cloud computing and edge computing shows great promise for the Connected and Automated Vehicle (CAV), by enabling CAVs to offload their massive on-board data and heavy computing tasks. Leveraging the Internet of Things (IoT) technology, different entities in the intelligent transportation system (e.g., vehicles, infrastructure, traffic management centers, etc.) get connected with each other, thus making the entire system smarter, faster, and more efficient. However, these advances also bring significant challenges to public authorities, industry, as well as scientific communities. In terms of system design and control, current cloud and edge architecture of CAVs need to be refined or even redesigned to better function under uncertainties in demand, and to better cooperate with existing conventional vehicles and infrastructure. From the performance assessment perspective, models and simulation tools based on artificial intelligence and big data have been widely developed for validation and evaluation of cloud computing and edge computing, but the validity of these models needs to be re-examined with field implementations. Finally, while the increasing connectivity among vehicles and infrastructures may help improve their perception of the environment and enable coordinated decision making, it also presents new challenges to ensure system safety and security, with inherent disturbances to wireless communication networks and also the inevitably larger attack surface that may be exploited by malicious attacks. In this tutorial, experts from academia and industry introduce the trends and challenges of applying cloud and edge computing for CAVs, highlight representative works in the literature and discuss their limitations, present new promising solutions, and outline future directions in research and engineering. Particular focus will be given to methodologies and tools for building digital twin frameworks with cloud and edge computing for CAVs, quantitative and formal analysis for ensuring CAV safety under disturbances and uncertainties, system-level CAV security threat landscape and defense solution space, and experiences from practical deployment of cloud and edge computing for CAVs.

This book is one of the first technical overviews of autonomous vehicles written for a general computing and engineering audience. The authors share their practical experiences designing autonomous vehicle systems. These systems are complex, consisting of three major subsystems: (1) algorithms for localization, perception, and planning and control; (2) client systems, such as the robotics operating system and hardware platform; and (3) the cloud platform, which includes data storage, simulation, high-definition (HD) mapping, and deep learning model training. The algorithm subsystem extracts meaningful information from sensor raw data to understand its environment and make decisions as to its future actions. The client subsystem integrates these algorithms to meet real-time and reliability requirements. The cloud platform provides offline computing and storage capabilities for autonomous vehicles. Using the cloud platform, new algorithms can be tested so as to update the HD map—in addition to training better recognition, tracking, and decision models. Since the first edition of this book was released, many universities have adopted it in their autonomous driving classes, and the authors received many helpful comments and feedback from readers. Based on this, the second edition was improved by extending and rewriting multiple chapters and adding two commercial test case studies. In addition, a new section entitled “Teaching and Learning from this Book” was added to help instructors better utilize this book in their classes. The second edition captures the latest advances in autonomous driving and that it also presents usable real-world case studies to help readers better understand how to utilize their lessons in commercial autonomous driving projects. This book should be useful to students, researchers, and practitioners alike. Whether you are an undergraduate or a graduate student interested in autonomous driving, you will find herein a comprehensive overview of the whole autonomous vehicle technology stack. If you are an autonomous driving practitioner, the many practical techniques introduced in this book will be of interest to you. Researchers will also find extensive references for an effective, deeper exploration of the various technologies.

Online social networks have already become a bridge connecting our physical daily life with the (web-based) information space. This connection produces a huge volume of data, not only about the information itself, but also about user behavior. The ubiquity of the social Web and the wealth of social data offer us unprecedented opportunities for studying the interaction patterns among users so as to understand the dynamic mechanisms underlying different networks, something that was previously difficult to explore due to the lack of available data. In this book, we present the architecture of the research for social network mining, from a microscopic point of view. We focus on investigating several key issues in social networks. Specifically, we begin with analytics of social interactions between users. The first kinds of questions we try to answer are: What are the fundamental factors that form the different categories of social ties? How have reciprocal relationships been developed from parasocial relationships? How do connected users further form groups? Another theme addressed in this book is the study of social influence. Social influence occurs when one's opinions, emotions, or behaviors are affected by others, intentionally or unintentionally. Considerable research has been conducted to verify the existence of social influence in various networks. However, few literature studies address how to quantify the strength of influence between users from different aspects. In Chapter 4 and in [138], we have studied how to model and predict user behaviors. One fundamental problem is distinguishing the effects of different social factors such as social influence, homophily, and individual's characteristics. We introduce a probabilistic model to address this problem. Finally, we use an academic social network, ArnetMiner, as an example to demonstrate how we apply the introduced technologies for mining real social networks. In this system, we try to mine knowledge from both the informative (publication) network and the social (collaboration) network, and to understand the interaction mechanisms between the two networks. The system has been in operation since 2006 and has already attracted millions of users from more than 220 countries/regions.

This book explores the question as to whether the way in which Chinese management handles conflict is fundamentally different from elsewhere or much the same. It does so by examining in detail an international joint venture construction project, where managers rooted in contrasting business systems were brought together, and by showing how the project progressed over time, how various conflict situations arose, and how they were handled. In addition the book provides an in-depth account of the inner workings of the Chinese business world, touching on issues such as:differing international standards and management proceduresthe peculiarities of Chinese red tape paternalism and nepotismthe limits on contract in contemporary Chinathe involvement of local officials. Of interest to scholars and managers alike, this study benefits from the unparalleled access the author secured to all the parties involved. Working alongside managers as a participant observer, Jia Tang uses the fine detail of ethnography to convey a vivid impression the lives of managers in China today and the forces with which they have to contend.

This study explores the question as to whether the way in which Chinese management handles conflict is fundamentally different from elsewhere or much the same. It does so by examining in detail an international joint venture construction project, where managers rooted in contrasting business systems were brought together, and by showing how the project progressed over time, how various conflict situations arose, and how they were handled. In addition, the book provides an in-depth account of the inner workings of the Chinese business world, touching on issues such as:differing international standards and management proceduresthe peculiarities of Chinese red tape paternalism and nepotismthe limits on contract in contemporary Chinathe involvement of local officials. Of interest to scholars and managers alike, this study benefits from the unparalleled access the author secured to all the parties involved. Working alongside managers as a participant observer, Jie Tang uses the fine detail of ethnography to convey a vivid impression of the lives of managers in China today and the forces with which they have to contend.

This book describes the design, synthesis, performance and practical application of energetic materials. The book consists of thirteen chapters demonstrating the design routes of nitrogen-rich polycyclic-based energetic materials that are bicyclic, tricyclic and tetracyclic-based. It presents the synthesis of the energetic backbone, the construction of linkage and the introduction of energetic units, which could have a positive impact on the chemistry of not only on high-energy-density materials but also in other fields. The book also provides detailed analysis of the experimental methods discussed. Work in this area will benefit from the combine expertise from organic, inorganic and physical chemistry as well as other connected disciplines. As such this book has wide appeal and will help in increasing fundamental knowledge of nitrogen-rich heterocycles to eventually allow for this knowledge to be transferred into industrial applications.

This book describes the design, synthesis, performance and practical application of energetic materials.