Big Data Concepts, Theories, and Applications

Download Big Data Concepts, Theories, and Applications PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319277634
Total Pages : 437 pages
Book Rating : 4.3/5 (192 download)

DOWNLOAD NOW!


Book Synopsis Big Data Concepts, Theories, and Applications by : Shui Yu

Download or read book Big Data Concepts, Theories, and Applications written by Shui Yu and published by Springer. This book was released on 2016-03-03 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers three major parts of Big Data: concepts, theories and applications. Written by world-renowned leaders in Big Data, this book explores the problems, possible solutions and directions for Big Data in research and practice. It also focuses on high level concepts such as definitions of Big Data from different angles; surveys in research and applications; and existing tools, mechanisms, and systems in practice. Each chapter is independent from the other chapters, allowing users to read any chapter directly. After examining the practical side of Big Data, this book presents theoretical perspectives. The theoretical research ranges from Big Data representation, modeling and topology to distribution and dimension reducing. Chapters also investigate the many disciplines that involve Big Data, such as statistics, data mining, machine learning, networking, algorithms, security and differential geometry. The last section of this book introduces Big Data applications from different communities, such as business, engineering and science. Big Data Concepts, Theories and Applications is designed as a reference for researchers and advanced level students in computer science, electrical engineering and mathematics. Practitioners who focus on information systems, big data, data mining, business analysis and other related fields will also find this material valuable.

Big Data

Download Big Data PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119701821
Total Pages : 370 pages
Book Rating : 4.1/5 (197 download)

DOWNLOAD NOW!


Book Synopsis Big Data by : Balamurugan Balusamy

Download or read book Big Data written by Balamurugan Balusamy and published by John Wiley & Sons. This book was released on 2021-04-13 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn Big Data from the ground up with this complete and up-to-date resource from leaders in the field Big Data: Concepts, Technology, and Architecture delivers a comprehensive treatment of Big Data tools, terminology, and technology perfectly suited to a wide range of business professionals, academic researchers, and students. Beginning with a fulsome overview of what we mean when we say, “Big Data,” the book moves on to discuss every stage of the lifecycle of Big Data. You’ll learn about the creation of structured, unstructured, and semi-structured data, data storage solutions, traditional database solutions like SQL, data processing, data analytics, machine learning, and data mining. You’ll also discover how specific technologies like Apache Hadoop, SQOOP, and Flume work. Big Data also covers the central topic of big data visualization with Tableau, and you’ll learn how to create scatter plots, histograms, bar, line, and pie charts with that software. Accessibly organized, Big Data includes illuminating case studies throughout the material, showing you how the included concepts have been applied in real-world settings. Some of those concepts include: The common challenges facing big data technology and technologists, like data heterogeneity and incompleteness, data volume and velocity, storage limitations, and privacy concerns Relational and non-relational databases, like RDBMS, NoSQL, and NewSQL databases Virtualizing Big Data through encapsulation, partitioning, and isolating, as well as big data server virtualization Apache software, including Hadoop, Cassandra, Avro, Pig, Mahout, Oozie, and Hive The Big Data analytics lifecycle, including business case evaluation, data preparation, extraction, transformation, analysis, and visualization Perfect for data scientists, data engineers, and database managers, Big Data also belongs on the bookshelves of business intelligence analysts who are required to make decisions based on large volumes of information. Executives and managers who lead teams responsible for keeping or understanding large datasets will also benefit from this book.

Big Data and Smart Service Systems

Download Big Data and Smart Service Systems PDF Online Free

Author :
Publisher : Academic Press
ISBN 13 : 0128120401
Total Pages : 232 pages
Book Rating : 4.1/5 (281 download)

DOWNLOAD NOW!


Book Synopsis Big Data and Smart Service Systems by : Xiwei Liu

Download or read book Big Data and Smart Service Systems written by Xiwei Liu and published by Academic Press. This book was released on 2016-11-23 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Big Data and Smart Service Systems presents the theories and applications regarding Big Data and smart service systems, data acquisition, smart cities, business decision-making support, and smart service design. The rapid development of computer and Internet technologies has led the world to the era of Big Data. Big Data technologies are widely used, which has brought unprecedented impacts on traditional industries and lifestyle. More and more governments, business sectors, and institutions begin to realize data is becoming the most valuable asset and its analysis is becoming the core competitiveness. Describes the frontier of service science and motivates a discussion among readers on a multidisciplinary subject areas that explores the design of smart service Illustrates the concepts, framework, and application of big data and smart service systems Demonstrates the crucial role of smart service to promote the transformation of the regional and global economy

Big Data: Concepts, Methodologies, Tools, and Applications

Download Big Data: Concepts, Methodologies, Tools, and Applications PDF Online Free

Author :
Publisher : IGI Global
ISBN 13 : 1466698411
Total Pages : 2478 pages
Book Rating : 4.4/5 (666 download)

DOWNLOAD NOW!


Book Synopsis Big Data: Concepts, Methodologies, Tools, and Applications by : Management Association, Information Resources

Download or read book Big Data: Concepts, Methodologies, Tools, and Applications written by Management Association, Information Resources and published by IGI Global. This book was released on 2016-04-20 with total page 2478 pages. Available in PDF, EPUB and Kindle. Book excerpt: The digital age has presented an exponential growth in the amount of data available to individuals looking to draw conclusions based on given or collected information across industries. Challenges associated with the analysis, security, sharing, storage, and visualization of large and complex data sets continue to plague data scientists and analysts alike as traditional data processing applications struggle to adequately manage big data. Big Data: Concepts, Methodologies, Tools, and Applications is a multi-volume compendium of research-based perspectives and solutions within the realm of large-scale and complex data sets. Taking a multidisciplinary approach, this publication presents exhaustive coverage of crucial topics in the field of big data including diverse applications, storage solutions, analysis techniques, and methods for searching and transferring large data sets, in addition to security issues. Emphasizing essential research in the field of data science, this publication is an ideal reference source for data analysts, IT professionals, researchers, and academics.

Handbook of Research for Big Data

Download Handbook of Research for Big Data PDF Online Free

Author :
Publisher :
ISBN 13 : 9781774639283
Total Pages : pages
Book Rating : 4.6/5 (392 download)

DOWNLOAD NOW!


Book Synopsis Handbook of Research for Big Data by : Brojo Kishore Mishra

Download or read book Handbook of Research for Big Data written by Brojo Kishore Mishra and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Data has become a valuable asset like never before. Today the challenge is not a shortage of data but the need for techniques and methods capable enough to be able to glean valuable insights from the fast-flowing mass of Big Data. This new volume, Handbook of Research for Big Data: Concepts and Techniques, helps to meet the challenge of managing and using Big Data by presenting new research on various technological advances in the field. The chapters in the book present information on important applications, concepts, and technologies for Big Data in the present industry and market scenario. It looks at research domain issues and their solutions as well as various research case studies, research plans, methodologies, and related data sets for the four Vs: volume, velocity, variety, and veracity. Chapters discuss Big Data in governance, transportation, disaster management, epidemiology, and more. The book covers design and analysis of reconfigurable computing of SoC for IoT, data mining techniques and applications, the use of natural language processing in big data, and more. The volume is a valuable resource for researchers from both academia and industry to learn about and enhance their knowledge and skills in the broad area of big data computing and applications.

Big Data Computing

Download Big Data Computing PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1466578378
Total Pages : 566 pages
Book Rating : 4.4/5 (665 download)

DOWNLOAD NOW!


Book Synopsis Big Data Computing by : Rajendra Akerkar

Download or read book Big Data Computing written by Rajendra Akerkar and published by CRC Press. This book was released on 2013-12-05 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to market forces and technological evolution, Big Data computing is developing at an increasing rate. A wide variety of novel approaches and tools have emerged to tackle the challenges of Big Data, creating both more opportunities and more challenges for students and professionals in the field of data computation and analysis. Presenting a mix of industry cases and theory, Big Data Computing discusses the technical and practical issues related to Big Data in intelligent information management. Emphasizing the adoption and diffusion of Big Data tools and technologies in industry, the book introduces a broad range of Big Data concepts, tools, and techniques. It covers a wide range of research, and provides comparisons between state-of-the-art approaches. Comprised of five sections, the book focuses on: What Big Data is and why it is important Semantic technologies Tools and methods Business and economic perspectives Big Data applications across industries

Big Data Fundamentals

Download Big Data Fundamentals PDF Online Free

Author :
Publisher : Prentice Hall
ISBN 13 : 0134291204
Total Pages : 423 pages
Book Rating : 4.1/5 (342 download)

DOWNLOAD NOW!


Book Synopsis Big Data Fundamentals by : Thomas Erl

Download or read book Big Data Fundamentals written by Thomas Erl and published by Prentice Hall. This book was released on 2015-12-29 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: “This text should be required reading for everyone in contemporary business.” --Peter Woodhull, CEO, Modus21 “The one book that clearly describes and links Big Data concepts to business utility.” --Dr. Christopher Starr, PhD “Simply, this is the best Big Data book on the market!” --Sam Rostam, Cascadian IT Group “...one of the most contemporary approaches I’ve seen to Big Data fundamentals...” --Joshua M. Davis, PhD The Definitive Plain-English Guide to Big Data for Business and Technology Professionals Big Data Fundamentals provides a pragmatic, no-nonsense introduction to Big Data. Best-selling IT author Thomas Erl and his team clearly explain key Big Data concepts, theory and terminology, as well as fundamental technologies and techniques. All coverage is supported with case study examples and numerous simple diagrams. The authors begin by explaining how Big Data can propel an organization forward by solving a spectrum of previously intractable business problems. Next, they demystify key analysis techniques and technologies and show how a Big Data solution environment can be built and integrated to offer competitive advantages. Discovering Big Data’s fundamental concepts and what makes it different from previous forms of data analysis and data science Understanding the business motivations and drivers behind Big Data adoption, from operational improvements through innovation Planning strategic, business-driven Big Data initiatives Addressing considerations such as data management, governance, and security Recognizing the 5 “V” characteristics of datasets in Big Data environments: volume, velocity, variety, veracity, and value Clarifying Big Data’s relationships with OLTP, OLAP, ETL, data warehouses, and data marts Working with Big Data in structured, unstructured, semi-structured, and metadata formats Increasing value by integrating Big Data resources with corporate performance monitoring Understanding how Big Data leverages distributed and parallel processing Using NoSQL and other technologies to meet Big Data’s distinct data processing requirements Leveraging statistical approaches of quantitative and qualitative analysis Applying computational analysis methods, including machine learning

Ethics of Big Data

Download Ethics of Big Data PDF Online Free

Author :
Publisher : "O'Reilly Media, Inc."
ISBN 13 : 1449357490
Total Pages : 80 pages
Book Rating : 4.4/5 (493 download)

DOWNLOAD NOW!


Book Synopsis Ethics of Big Data by : Kord Davis

Download or read book Ethics of Big Data written by Kord Davis and published by "O'Reilly Media, Inc.". This book was released on 2012-09-13 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: What are your organization’s policies for generating and using huge datasets full of personal information? This book examines ethical questions raised by the big data phenomenon, and explains why enterprises need to reconsider business decisions concerning privacy and identity. Authors Kord Davis and Doug Patterson provide methods and techniques to help your business engage in a transparent and productive ethical inquiry into your current data practices. Both individuals and organizations have legitimate interests in understanding how data is handled. Your use of data can directly affect brand quality and revenue—as Target, Apple, Netflix, and dozens of other companies have discovered. With this book, you’ll learn how to align your actions with explicit company values and preserve the trust of customers, partners, and stakeholders. Review your data-handling practices and examine whether they reflect core organizational values Express coherent and consistent positions on your organization’s use of big data Define tactical plans to close gaps between values and practices—and discover how to maintain alignment as conditions change over time Maintain a balance between the benefits of innovation and the risks of unintended consequences

Data Science

Download Data Science PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 0429554354
Total Pages : 325 pages
Book Rating : 4.4/5 (295 download)

DOWNLOAD NOW!


Book Synopsis Data Science by : Qurban A Memon

Download or read book Data Science written by Qurban A Memon and published by CRC Press. This book was released on 2019-09-26 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide an internationally respected collection of scientific research methods, technologies and applications in the area of data science. This book can prove useful to the researchers, professors, research students and practitioners as it reports novel research work on challenging topics in the area surrounding data science. In this book, some of the chapters are written in tutorial style concerning machine learning algorithms, data analysis, information design, infographics, relevant applications, etc. The book is structured as follows: • Part I: Data Science: Theory, Concepts, and Algorithms This part comprises five chapters on data Science theory, concepts, techniques and algorithms. • Part II: Data Design and Analysis This part comprises five chapters on data design and analysis. • Part III: Applications and New Trends in Data Science This part comprises four chapters on applications and new trends in data science.

Big-Data Analytics and Cloud Computing

Download Big-Data Analytics and Cloud Computing PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319253131
Total Pages : 169 pages
Book Rating : 4.3/5 (192 download)

DOWNLOAD NOW!


Book Synopsis Big-Data Analytics and Cloud Computing by : Marcello Trovati

Download or read book Big-Data Analytics and Cloud Computing written by Marcello Trovati and published by Springer. This book was released on 2016-01-12 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the theoretical concepts, leading-edge techniques and practical tools involved in the latest multi-disciplinary approaches addressing the challenges of big data. Illuminating perspectives from both academia and industry are presented by an international selection of experts in big data science. Topics and features: describes the innovative advances in theoretical aspects of big data, predictive analytics and cloud-based architectures; examines the applications and implementations that utilize big data in cloud architectures; surveys the state of the art in architectural approaches to the provision of cloud-based big data analytics functions; identifies potential research directions and technologies to facilitate the realization of emerging business models through big data approaches; provides relevant theoretical frameworks, empirical research findings, and numerous case studies; discusses real-world applications of algorithms and techniques to address the challenges of big datasets.

Big Data Technologies and Applications

Download Big Data Technologies and Applications PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319445502
Total Pages : 400 pages
Book Rating : 4.3/5 (194 download)

DOWNLOAD NOW!


Book Synopsis Big Data Technologies and Applications by : Borko Furht

Download or read book Big Data Technologies and Applications written by Borko Furht and published by Springer. This book was released on 2016-09-16 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this book is to introduce the basic concepts of big data computing and then to describe the total solution of big data problems using HPCC, an open-source computing platform. The book comprises 15 chapters broken into three parts. The first part, Big Data Technologies, includes introductions to big data concepts and techniques; big data analytics; and visualization and learning techniques. The second part, LexisNexis Risk Solution to Big Data, focuses on specific technologies and techniques developed at LexisNexis to solve critical problems that use big data analytics. It covers the open source High Performance Computing Cluster (HPCC Systems®) platform and its architecture, as well as parallel data languages ECL and KEL, developed to effectively solve big data problems. The third part, Big Data Applications, describes various data intensive applications solved on HPCC Systems. It includes applications such as cyber security, social network analytics including fraud, Ebola spread modeling using big data analytics, unsupervised learning, and image classification. The book is intended for a wide variety of people including researchers, scientists, programmers, engineers, designers, developers, educators, and students. This book can also be beneficial for business managers, entrepreneurs, and investors.

Research Anthology on Big Data Analytics, Architectures, and Applications

Download Research Anthology on Big Data Analytics, Architectures, and Applications PDF Online Free

Author :
Publisher : IGI Global
ISBN 13 : 1668436639
Total Pages : 1988 pages
Book Rating : 4.6/5 (684 download)

DOWNLOAD NOW!


Book Synopsis Research Anthology on Big Data Analytics, Architectures, and Applications by : Management Association, Information Resources

Download or read book Research Anthology on Big Data Analytics, Architectures, and Applications written by Management Association, Information Resources and published by IGI Global. This book was released on 2021-09-24 with total page 1988 pages. Available in PDF, EPUB and Kindle. Book excerpt: Society is now completely driven by data with many industries relying on data to conduct business or basic functions within the organization. With the efficiencies that big data bring to all institutions, data is continuously being collected and analyzed. However, data sets may be too complex for traditional data-processing, and therefore, different strategies must evolve to solve the issue. The field of big data works as a valuable tool for many different industries. The Research Anthology on Big Data Analytics, Architectures, and Applications is a complete reference source on big data analytics that offers the latest, innovative architectures and frameworks and explores a variety of applications within various industries. Offering an international perspective, the applications discussed within this anthology feature global representation. Covering topics such as advertising curricula, driven supply chain, and smart cities, this research anthology is ideal for data scientists, data analysts, computer engineers, software engineers, technologists, government officials, managers, CEOs, professors, graduate students, researchers, and academicians.

Big Data Concepts, Technologies, and Applications

Download Big Data Concepts, Technologies, and Applications PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1000965074
Total Pages : 124 pages
Book Rating : 4.0/5 (9 download)

DOWNLOAD NOW!


Book Synopsis Big Data Concepts, Technologies, and Applications by : Mohammad Shahid Husain

Download or read book Big Data Concepts, Technologies, and Applications written by Mohammad Shahid Husain and published by CRC Press. This book was released on 2023-10-25 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of such advanced technologies as cloud computing, the Internet of Things, the Medical Internet of Things, the Industry Internet of Things and sensor networks as well as the exponential growth in the usage of Internet-based and social media platforms, there are enormous oceans of data. These huge volumes of data can be used for effective decision making and improved performance if analyzed properly. Due to its inherent characteristics, big data is very complex and cannot be handled and processed by traditional database management approaches. There is a need for sophisticated approaches, tools and technologies that can be used to store, manage and analyze these enormous amounts of data to make the best use of them. Big Data Concepts, Technologies, and Applications covers the concepts, technologies, and applications of big data analytics. Presenting the state-of-the-art technologies in use for big data analytics. it provides an in-depth discussion about the important sectors where big data analytics has proven to be very effective in improving performance and helping industries to remain competitive. This book provides insight into the novel areas of big data analytics and the research directions for the scholars working in the domain. Highlights include: The advantages, disadvantages and challenges of big data analytics State-of-the-art technologies for big data analytics such as Hadoop, NoSQL databases, data lakes, deep learning and blockchain The application of big data analytic in healthcare, business, social media analytics, fraud detection and prevention and governance Exploring the concepts and technologies behind big data analytics, the book is an ideal resource for researchers, students, data scientists, data analysts and business analysts who need insight into big data analytics

Big Data

Download Big Data PDF Online Free

Author :
Publisher :
ISBN 13 : 9781119701859
Total Pages : pages
Book Rating : 4.7/5 (18 download)

DOWNLOAD NOW!


Book Synopsis Big Data by : Balamurugan Balusamy

Download or read book Big Data written by Balamurugan Balusamy and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book offers comprehensive coverage of Big Data tools, terminologies and technologies for researchers, business professionals and graduates. This book begins with an overview of what Big Data is and emphasizes all the key concepts of big data end to end. Big Data concepts, technologies, terminologies and storing, processing and analysis techniques and much more -- are all logically organized and reinforced by diagrams and case studies. This book refines readers' understanding of Big Data with in-depth analysis of key concepts. The case studies provided in this book give insight on key concepts. The initial chapters of the book shed light on various characteristics of Big Data that distinguish it from traditional Database Management systems. Big Data Analytics are covered in detail in a separate chapter. Hadoop, the heart of Big Data is handled in the Big Data processing chapter and a deep understanding of its concepts is provided"--

Big Data Science in Finance

Download Big Data Science in Finance PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119602971
Total Pages : 336 pages
Book Rating : 4.1/5 (196 download)

DOWNLOAD NOW!


Book Synopsis Big Data Science in Finance by : Irene Aldridge

Download or read book Big Data Science in Finance written by Irene Aldridge and published by John Wiley & Sons. This book was released on 2021-01-08 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explains the mathematics, theory, and methods of Big Data as applied to finance and investing Data science has fundamentally changed Wall Street—applied mathematics and software code are increasingly driving finance and investment-decision tools. Big Data Science in Finance examines the mathematics, theory, and practical use of the revolutionary techniques that are transforming the industry. Designed for mathematically-advanced students and discerning financial practitioners alike, this energizing book presents new, cutting-edge content based on world-class research taught in the leading Financial Mathematics and Engineering programs in the world. Marco Avellaneda, a leader in quantitative finance, and quantitative methodology author Irene Aldridge help readers harness the power of Big Data. Comprehensive in scope, this book offers in-depth instruction on how to separate signal from noise, how to deal with missing data values, and how to utilize Big Data techniques in decision-making. Key topics include data clustering, data storage optimization, Big Data dynamics, Monte Carlo methods and their applications in Big Data analysis, and more. This valuable book: Provides a complete account of Big Data that includes proofs, step-by-step applications, and code samples Explains the difference between Principal Component Analysis (PCA) and Singular Value Decomposition (SVD) Covers vital topics in the field in a clear, straightforward manner Compares, contrasts, and discusses Big Data and Small Data Includes Cornell University-tested educational materials such as lesson plans, end-of-chapter questions, and downloadable lecture slides Big Data Science in Finance: Mathematics and Applications is an important, up-to-date resource for students in economics, econometrics, finance, applied mathematics, industrial engineering, and business courses, and for investment managers, quantitative traders, risk and portfolio managers, and other financial practitioners.

Data Science

Download Data Science PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 0429558821
Total Pages : 403 pages
Book Rating : 4.4/5 (295 download)

DOWNLOAD NOW!


Book Synopsis Data Science by : Qurban A Memon

Download or read book Data Science written by Qurban A Memon and published by CRC Press. This book was released on 2019-09-26 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide an internationally respected collection of scientific research methods, technologies and applications in the area of data science. This book can prove useful to the researchers, professors, research students and practitioners as it reports novel research work on challenging topics in the area surrounding data science. In this book, some of the chapters are written in tutorial style concerning machine learning algorithms, data analysis, information design, infographics, relevant applications, etc. The book is structured as follows: • Part I: Data Science: Theory, Concepts, and Algorithms This part comprises five chapters on data Science theory, concepts, techniques and algorithms. • Part II: Data Design and Analysis This part comprises five chapters on data design and analysis. • Part III: Applications and New Trends in Data Science This part comprises four chapters on applications and new trends in data science.

Intelligent Systems Design and Applications

Download Intelligent Systems Design and Applications PDF Online Free

Author :
Publisher : Springer Nature
ISBN 13 : 3030711870
Total Pages : 1440 pages
Book Rating : 4.0/5 (37 download)

DOWNLOAD NOW!


Book Synopsis Intelligent Systems Design and Applications by : Ajith Abraham

Download or read book Intelligent Systems Design and Applications written by Ajith Abraham and published by Springer Nature. This book was released on 2021-06-02 with total page 1440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights recent research on intelligent systems and nature-inspired computing. It presents 130 selected papers from the 19th International Conference on Intelligent Systems Design and Applications (ISDA 2020), which was held online. The ISDA is a premier conference in the field of computational intelligence, and the latest installment brought together researchers, engineers and practitioners whose work involves intelligent systems and their applications in industry. Including contributions by authors from 40 countries, the book offers a valuable reference guide for all researchers, students and practitioners in the fields of Computer Science and Engineering.