Beginning LEGO MINDSTORMS EV3 shows you how to create new fun and fantastic creations with the new EV3 programmable brick along with other new EV3 pieces and features. You'll learn the language of the EV3 brick, and then go on to create a variety of programmable vehicles using MINDSTORMS and Technic parts. You'll then move into creating robot parts, including robotic arms. You'll even learn how to make different types of MINDSTORMS walkers. Finally, you'll learn how to incorporate light and sound into your amazing EV3 creations. Whether you're a MINDSTORMS enthusiast wanting to know more about EV3, a robotics competitor, or just a LEGO fan who wants to learn all about what EV3 can do, Beginning LEGO MINDSTORMS EV3 will give you the knowledge you need. What you'll learn * How to program the new EV3 brick * The different components new to the EV3 system * How to program the EV3 with LabView * How to build fantastic robotic creations * How to incorporate Technic creations into MINDSTORMS Who this book is for MINDSTORMS and robotics enthusiasts who want to learn about EV3, and people who are completely new to MINDSTORMS and want a thorough and fun introduction.

Dieses Buch vermittelt geballtes Wissen zur Halbleiter-SchaltungstechnikSeit nunmehr 50 Jahren ist dieses Buch uber die Schaltungstechnik auf dem Markt, doch in die Jahre gekommen ist es noch lange nicht. Auch die 16. Auflage wurde von den Verfassern intensiv uberarbeitet und erweitert und stellt dem Leser viele wichtige Themen der Halbleiter-Schaltungstechnik vor, darunter eine Einfuhrung in die Digitaltechnik, Anwendungsmoeglichkeiten in Bauelementen und Schaltungen der Nachrichtentechnik. Inhalte richten sich Praktiker und Studierende Von den Inhalten dieses Buchs uber die Schaltungstechnik profitieren sowohl Studenten als auch Ingenieure. Samtliche Kapitel wurden entsprechend der neuesten technischen Entwicklungen uberarbeitet. Es vermittelt Grundlagenwissen aber auch tiefergehende Informationen.

Mit zunehmender Popularitat werden Drohnen nicht nur privat, sondern auch beispielsweise in der Landwirtschaft oder Wissenschaft erfolgreich eingesetzt. Obwohl es immer wieder zu negativen Schlagzeilen kommt, bleiben sie ein Erfolg. Aber haben Sie sich schon mal Gedanken gemacht, wie Drohnen uberhaupt funktionieren? Oder welche Probleme bei der Entwicklung entstehen?Die Elektronik einer Drohne besteht aus einer Vielzahl von Komponenten, die naher beschrieben und ihr Zusammenspiel erklart wird. Dabei wird die Thematik so erlautert, dass sie auch ohne tiefgreifendes technisches Vorwissen verstanden werden kann.

Get the most out of your printer, including how to design models, choose materials, work with different printers, and integrate 3D printing with traditional prototyping to make techniques like sand casting more efficient.This book is for new 3D printer owners, makers of all kinds, entrepreneurs, technology educators, and anyone curious about what you can do with a 3D printer. In this revised and expanded new edition of Mastering 3D Printing, which has been a trusted resource through five years of evolution in the 3D printing industry, you'll gain a comprehensive understanding of 3D printing. This book presumes no foreknowledge and describes what you need to know about how printers work, how to decide which type of printer (filament, resin, or powder) makes the most sense for you, and then how to go forward in the case of filament and resin printers. This new edition now includes material about consumer resin printing, the evolution of lower-cost metal printing, and the plethora of both materials and applications. What You'll Learn Choose among the different 3D printing technologies Create or find 3D models to print Make both easy and challenging prints come out as you imagined Assess whether your business, factory, home or classroom will benefit from 3D printing Work with applications that are good candidates for first projects in home and industrial applications Who This Book Is For People who are encountering 3D printing for the first time, or for those who want to level up their skills. It is designed for the nontechnical adult and minimizes jargon. However more sophisticated users will still find tips and insights of value.

This textbook, based on the authors' fifteen years of teaching, is a complete teaching tool for turning students into logic designers in one semester. Each chapter describes new concepts, giving extensive applications and examples. Assuming no prior knowledge of discrete mathematics, the authors introduce all background in propositional logic, asymptotics, graphs, hardware and electronics. Important features of the presentation are: * All material is presented in full detail. Every designed circuit is formally specified and implemented, the correctness of the implementation is proved, and the cost and delay are analyzed * Algorithmic solutions are offered for logical simulation, computation of propagation delay and minimum clock period * Connections are drawn from the physical analog world to the digital abstraction * The language of graphs is used to describe formulas and circuits * Hundreds of figures, examples and exercises enhance understanding. The extensive website (http://www.eng.tau.ac.il/~guy/Even-Medina/) includes teaching slides, links to Logisim and a DLX assembly simulator.

Build functioning wind turbines that generate electricity; we don't mean LEGO models that look like miniature wind turbines. This book is for people who want to learn how real turbines work, and to build them using LEGO and Mindstorms EV3. You'll find specific instructions on building, links to parts purchasing, distillation of complex science ideas into practice, and pointers for trying something new. With the knowledge you gain here, you'll be able to compete in turbine design competitions, such as the KidWind Challenge, Collegiate Wind Competition, and locally organized contests. Examples are given that fit within the KidWind Challenge, including adherence to rules of the competition such as that a specific generator be used. The complexity of making a wind turbine a can make it difficult to know where to start. This book addresses many aspects of the turbine with practical examples. You'll follow specific design instructions for turbine construction, supported by suggestions and background science to go in new directions. Assembly diagrams are used throughout, made with the Studio utility from bricklink.com. Parts are identified in the assembly diagram, as well as in parts lists in the Appendix. What You'll Learn Build a turbine from scratch Use LEGO to learn aspects of electrical engineering, such as loading turbine output and impedance matching Connect a generator to do useful things such as charging a battery or powering LEDs See how generators, gear systems, aerodynamic blades, lab and outdoor testing, and power output are used. Who This Book Is For Adult fans of LEGO and hardware hackers. Also coaches or students involved in a school science/technology project or design competition.

Learn the basics of using the micro: bit, an open source hardware ARM-based embedded system used to teach computer programming, to build a series of 10 different gadgets from scratch! You'll use the micro: bit to make: a scrolling name tag, animated LED displays a high-tech compass. a handheld tilting game with a buzzer and saved high score a carnival-like strength tester a powered cooling fan helmet an electronic musical instrument a security system that sends alerts to your computer when someone enters the room. a wheeled robot an alert to water your plants You will learn how simple electrical devices like speakers, motors, buzzers and fans work. You'll understand electronic components like resistors, force resistors, photoresistors, LEDs, and Op Amps, as well as Infrared distance sensors and soil moisture sensors. You'll also get a beginner's look at micropython, one of the fastest-growing computer languages. In this book you will combine multiple disciplines -- electronics, programming, and engineering -- to build a series of successful gadgets. Everything is explained with lots and lots of full-color line drawings. No prior experience is necessary. You'll have fun while you learn a ton!

After the devastating tsunami in 2011, DYIers in Japan built their own devices to detect radiation levels, then posted their finding on the Internet. Right now, thousands of people worldwide are tracking environmental conditions with monitoring devices they've built themselves. You can do it too

This inspiring guide shows you how to use Arduino to create gadgets for measuring noise, weather, electromagnetic interference (EMI), water purity, and more. You'll also learn how to collect and share your own data, and you can experiment by creating your own variations of the gadgets covered in the book. If you're new to DIY electronics, the first chapter offers a primer on electronic circuits and Arduino programming.Use a special microphone and amplifier to build a reliable noise monitorCreate a gadget to detect energy vampires: devices that use electricity when they're "off"Examine water purity with a water conductivity deviceMeasure weather basics such as temperature, humidity, and dew pointBuild your own Geiger counter to gauge background radiationExtend Arduino with an Ethernet shield--and put your data on the InternetShare your weather and radiation data online through Pachube

Get started programming Rust applications for the Internet of Things (IoT). This book is a programming skills migration book that teaches you the Rust programming techniques most useful for IoT applications. You'll step through from server to board development in creating a set of IoT applications. In Rust for the IoT, you'll learn how to build a modern server-side application using Rust on the backend. Then you'll use docker and Kubernetes to deploy these to a managed cloud. Finally you will use a Raspberry Pi with a SenseHat and Camera to capture the world around you and send that information to the cloud. While you will be able to follow along without any cloud or hardware, to make the most of it we recommend a few cloud pieces and hardware that is designed to integrate with the software in this book. After reading and using this book, you'll see how to apply Rust to the Internet of Things. What You Will Learn Create a modern Rust backend complete with handling eventual consistency and interacting via a GraphQL interface Use the Raspberry PI to serve as a cheap IoT device that one can easily deploy around the house Capture temperature, video, and use the interactive joystick to interact with the software you've created Use OpenCV to perform facial detection from the PI's camera and save that information to the cloud. Create deployable helm charts for the cloud, and for the device create complete ISOs that allow you to easily deploy the Pi's OS + custom software Who This Book Is For You will need to have a basic understanding of cloud application development at a minimum and the basics of Rust coding. This book is for those interested in or working with the IoT and the Raspberry Pi who want to learn how Rust can work for them.

Program in Python on a Raspberry Pi or PC by developing six computer games. Each game project is split into several chapters of the book. Rather than taking you through programming techniques as standalone concepts, this book explains concepts as they are used within a game. You'll learn about variables; integer, real, Boolean and string data types; conditional if statements; fixed loops and conditional loops; modularity; arrays and lists; and predefined functions. You'll also discover the PyGame library, which is popularly used in the development of 2D games. Key programming concepts are revisited in subsequent projects in the book to consolidate prior learning. Beyond teaching you how to code, this book explains the programming logic behind each project-exemplifying the process of designing and writing a computer game. All the projects in this book are supported by Code Angel (mycodeangel.com). Code Angel Code Angel largely serves students and new developers and the projects work by encouraging you to 'Learn...then play'. Taking this approach, you'll be able to build fun 2D games and enjoy playing them by yourself or with friends. Developing games in this way keeps you engaged, gives a purpose as you work through each project, and offers a sense of achievement when each game is finished. What You'll Learn Integrate the fundamentals of the Python 3 programming language Program fun, classic computer games you can then play Develop computational thinking skills and abilities that can be applied to other ventures Who This Book Is For Students, hobbyists, new developers or anyone wishing to learn how to design and write computer games.

Hone your understanding of science and engineering concepts with the versatile Arduino microcontroller and powerful Raspberry Pi mini-computer. The simple, straightforward, fun projects in this book use the Arduino and Raspberry Pi to build systems that explore key scientific concepts and develop engineering skills. Areas explored include force/acceleration, heat transfer, light, and astronomy. You'll work with advanced tools, such as data logging, advanced design, manufacturing, and assembly techniques that will take you beyond practical application of the projects you'll be creating. Technology is ever evolving and changing. This book goes beyond simple how-tos to teach you the concepts behind these projects and sciences. You'll gain the skills to observe and adapt to changes in technology as you work through fun and easy projects that explore fundamental concepts of engineering and science. What You'll Learn Measure the acceleration of a car you're riding in Simulate zero gravity Calculate the heat transfer in and out of your house Photography the moon and planets Who This Book Is ForHobbyists, students, and instructors interested in practical applications and methods to measure and learn about the physical world using inexpensive Maker technologies.

Apply machine learning using the Internet of Things (IoT) in the agriculture, telecom, and energy domains with case studies. This book begins by covering how to set up the software and hardware components including the various sensors to implement the case studies in Python. The case study section starts with an examination of call drop with IoT in the telecoms industry, followed by a case study on energy audit and predictive maintenance for an industrial machine, and finally covers techniques to predict cash crop failure in agribusiness. The last section covers pitfalls to avoid while implementing machine learning and IoT in these domains. After reading this book, you will know how IoT and machine learning are used in the example domains and have practical case studies to use and extend. You will be able to create enterprise-scale applications using Raspberry Pi 3 B+ and Arduino Mega 2560 with Python. What You Will Learn Implement machine learning with IoT and solve problems in the telecom, agriculture, and energy sectors with Python Set up and use industrial-grade IoT products, such as Modbus RS485 protocol devices, in practical scenarios Develop solutions for commercial-grade IoT or IIoT projects Implement case studies in machine learning with IoT from scratch Who This Book Is For Raspberry Pi and Arduino enthusiasts and data science and machine learning professionals.

This book shows you how to build real-time image processing systems all the way through to house automation. Find out how you can develop a system based on small 32-bit ARM processors that gives you complete control through voice commands. Real-time image processing systems are utilized in a wide variety of applications, such as in traffic monitoring systems, medical image processing, and biometric security systems. In Real-Time IoT Imaging with Deep Neural Networks, you will learn how to make use of the best DNN models to detect object in images using Java and a wrapper for OpenCV. Take a closer look at how Java scripting works on the Raspberry Pi while preparing your Visual Studio code for remote programming. You will also gain insights on image and video scripting. Author Nicolas Modrzyk shows you how to use the Rhasspy voice platform to add a powerful voice assistant and completely run and control your Raspberry Pi from your computer. To get your voice intents for house automation ready, you will explore how Java connects to the MQTT and handles parametrized Rhasspy voice commands. With your voice-controlled system ready for operation, you will be able to perform simple tasks such as detecting cats, people, and coffee pots in your selected environment. Privacy and freedom are essential, so priority is given to using open source software and an on-device voice environment where you have full control of your data and video streams. Your voice commands are your own-and just your own. With recent advancements in the Internet of Things and machine learning, cutting edge image processing systems provide complete process automation. This practical book teaches you to build such a system, giving you complete control with minimal effort. What You Will Learn: Show mastery by creating OpenCV filters Execute a YOLO DNN model for image detection Apply the best Java scripting on Raspberry Pi 4 Prepare your setup for real-time remote programming Use the Rhasspy voice platform for handling voice commands and enhancing your house automation setup Who This Book Is For:Engineers, and Hobbyists wanting to use their favorite JVM to run Object Detection and Networks on a Raspberry Pi

Compile and run Bitcoin full nodes, lightning nodes, and user-friendly web-apps that help abstract the complexities of Bitcoin. This book not only explains the tools and techniques to help readers build their own banks and banking apps, but it also tells a story. Starting with the origins of Bitcoin-what it is and why we need it-find out what its strengths and limitations are. Understand the nature of mining and why so much energy is put into it. The blockchain itself will be reviewed, as well, and compared to other options such as a normal SQL database or a simple spreadsheet. With this book, you can control Bitcoin wallets via RPC commands on a Raspberry Pi. Configure, compile, and run two implementation of the Lightning Network-compatible daemons: LND and c-lightning. And employ user-friendly web apps that abstract the complexities of Bitcoin/Lightning-Network. The Internet of Information is currently transitioning to the Internet of Things, which in turn may well be followed by the Internet of Value (or Money). However, there is no evolution without happy users and Bitcoin will never reach the same heights like the original internet without having offered "useful" and "easy to use" tools. Just like nobody would ever want to use UUCP to send messages via web the same applies to current cryptocurrency tools. These are hard to use and very unforgiving. But, the evolution doesn't stop here and many easy-to-use tools are already available. We will meet some of them when building apps for the Lightning Network, a new technology running on top of Bitcoin's blockchain that makes it possible to generate billions of transactions within a single second. What You'll Learn Control Bitcoin wallets via console RPC commands Run two implementation of the Lightning Network compatible daemons Simplify the complexities of Bitcoin and the Lightning network with user-friendly web apps Who This Book Is For This book is for Makers familiar with the basics of Linux command line processes.

Architect IoT solutions in any domain using the vast power of IoT architectural patterns with this hands-on guide Key Features * Speed up the process of implementing IoT solutions through the use of IoT architectural patterns * Look beyond the nature of the domain to see the underlying commonalities in IoT implementations * Learn how IoT architectural patterns are used today in a wide variety of contexts Book Description IoT is growing ever larger, and as it grows and moves to new domains, it requires architectural patterns to enable faster and more uniform development. Theoretical knowledge of patterns is all well and good, but how do you implement them? IoT Architectural Patterns in Practice has the answer. Through numerous use cases and examples, it helps you to conceptualize and implement IoT architectural patterns and use them in diverse contexts in the real world. You'll be introduced to a variety of IoT architectural patterns and then see how they are used in domains such as retail, smart manufacturing, and smart agriculture. Once you've examined the use cases and applicable patterns, you'll roll up your IoT sleeves and get hands-on with the implementation of the patterns, giving you the knowledge and practice to implement unique IoT solutions with the architectural patterns you've learned here. You'll look at security, project management, and operational efficiency, as well as data analytics. By the end of the book, you will be able to architect scalable, secure, and performance-optimized IoT solutions in any domain using the power of IoT architectural patterns, and you'll avoid the pitfalls that derail many IoT projects. What you will learn * Monitor the physical world using a Device Gateway * Choose the right sensors and actuators for your solution * Explore edge analytics, streaming analytics, and data lakes * Overcome the challenges of securing IoT systems * Prepare a typical IoT project management risk register * Ensure optimum test coverage * Implement use cases in which edge computing plays a prominent role * Differentiate between constrained devices and normal devices Who This Book Is For This book is relevant for IoT architects, CXOs, and technical directors, as well as IoT developers and semi-technical people such as technical program managers, technical pre-sales, and so on who are interested in understanding the fundamental patterns that are relevant in IoT and how these patterns can be mixed and matched to implement unique and diverse IoT applications. Prior knowledge of IoT fundamental concepts and related examples is assumed for using this book.

This book constitutes the proceedings of the 7th International Workshop on Design, Modeling, and Evaluation of Cyber Physical Systems, CyPhy2017, held in conjunction with ESWeek 2017, in Seoul, South Korea, in October 2017. The 10 papers presented together with 1 extended and 1 invited abstracts in this volume were carefully reviewed and selected from 16 submissions. The conference presents a wide range of domains including robotics; smart homes, vehicles, and buildings; medical implants; and future-generation sensor networks.

This book constitutes the thoroughly refereed post-conference proceedings of the 13th International Conference on High Performance Computing in Computational Science, VECPAR 2018, held in Sao Pedro, Brazil, in September 2018. The 17 full papers and one short paper included in this book were carefully reviewed and selected from 32 submissions presented at the conference. The papers cover the following topics: heterogeneous systems, shared memory systems and GPUs, and techniques including domain decomposition, scheduling and load balancing, with a strong focus on computational science applications.

Dieses zweibandige, grundlegende und tiefgehende Werk uber analoge und digitale Schaltungstechnik bietet neben einer verstandlichen Darstellung des Lehrstoffs viele umfangreiche Lernhilfen. Es ist daher besonders fur Einsteiger und zum Selbst- und Fernstudium geeignet. Eine Vielzahl von detailliert durchgerechneten Beispielen, Aufgaben mit ausfuhrlichen Losungsvorschlagen, Merksatzen und Kapitelzusammenfassungen erleichtern das Lernen ebenso wie die zahlreichen Abbildungen und Tabellen. Das Werk entstand aus einer Vorlesung an der Fernuniversitat Hagen. Der zweite Band behandelt Aufbau und Schaltungen des Operationsverstarkers, Digitale Schaltungen (Gatter-Familien, Flip-Flop-Typen, Dekoder/Enkoder, Multiplexer, Minimierungs- verfahren) sowie Verbindungsleitungen."

This book constitutes the refereed proceedings of the 22st International Symposium on VLSI Design and Test, VDAT 2018, held in Madurai, India, in June 2018. The 39 full papers and 11 short papers presented together with 8 poster papers were carefully reviewed and selected from 231 submissions. The papers are organized in topical sections named: digital design; analog and mixed signal design; hardware security; micro bio-fluidics; VLSI testing; analog circuits and devices; network-on-chip; memory; quantum computing and NoC; sensors and interfaces.

Learn to set up a Pi-based game development environment, and then develop a game with Lua, a popular scripting language used in major game frameworks like Unreal Engine (BioShock Infinite), CryEngine (Far Cry series), Diesel (Payday: The Heist), Silent Storm Engine (Heroes of Might and Magic V) and many others. More importantly, learn how to dig deeper into programming languages to find and understand new functions, frameworks, and languages to utilize in your games. You'll start by learning your way around the Raspberry Pi. Then you'll quickly dive into learning game development with an industry-standard and scalable language. After reading this book, you'll have the ability to write your own games on a Raspberry Pi, and deliver those games to Linux, Mac, Windows, iOS, and Android. And you'll learn how to publish your games to popular marketplaces for those desktop and mobile platforms. Whether you're new to programming or whether you've already published to markets like Itch.io or Steam, this book showcases compelling reasons to use the Raspberry Pi for game development. Use Developing Games on the Raspberry Pi as your guide to ensure that your game plays on computers both old and new, desktop or mobile. What You'll Learn Confidently write programs in Lua and the LOVE game engine on the Raspberry Pi Research and learn new libraries, methods, and frameworks for more advanced programming Write, package, and sell apps for mobile platforms Deliver your games on multiple platforms Who This Book Is ForSoftware engineers, teachers, hobbyists, and development professionals looking to up-skill and develop games for mobile platforms, this book eases them into a parallel universe of lightweight, POSIX, ARM-based development.

Learn programming using the Commodore 16/Plus 4 system. Following this book, you and your children will not only learn BASIC programming, but also have fun emulating a retro Commodore system. There are many ways to bring the fun of learning to program in the 1980s back to life. For example, downloading the VICE emulator to a Raspberry Pi allows for the classic "turn on and program" experience and also provides some retro computing project fun. Many parents learned programming in this same way and can have fun helping their children follow the same path. You can also use this book as an opportunity to dust off your computing skills or learn programming concepts for the first time on a system that's easy, approachable, and fun with a nostalgic twist. Commodore computers were the most sold computing devices before the iPhone. Nowadays, the Commodore system can be run using freely available emulation on modern computers. This book uses VICE, which is available for PC, Mac, Linux, as an online app, and on the Raspberry Pi. Beginning Programming Using Retro Computing offers simple programming concepts to give children and adults alike a sense of wonder in seeing that words they write have the power to do things, like play sounds, draw graphics, or finish math homework.

Microcontrollers and Microcomputers: Principles of Software and Hardware Engineering, Second Edition, is an ideal introductory text for an embedded system or microcontroller course. While most texts discuss only one specific microcontroller, this book offers a unique approach by covering the common ground among all microcontrollers in one volume.
Since the text does not focus on a particular processor, it can be used with processor-specific material--such as manufacturer's data sheets and reference manuals--or with texts, including author Fredrick M. Cady's Software and Hardware Engineering: Motorola M68HC11 or Software and HardwareEngineering: Motorola M68HC12. Now fully updated, the second edition covers the fundamental operation of standard microcontroller features, including parallel and serial I/O interfaces, interrupts, analog-to-digital conversion, and timers, focusing on the electrical interfaces as needed. It devotes one chapter to showing how a variety of devices can be used, and emphasizes C program software development, design, and debugging.

Use the Raspberry Pi and modern computing techniques to build industrial Internet of Things systems. Principles and theoretical aspects of IoT technologies combine with hands-on projects leading to detailed descriptions of several industrial IoT applications. This book presents real-life IoT applications based on the Raspberry Pi, beyond the relatively simplistic demos built for educational purposes or hobbyists. You'll make the transition from tinkering with a couple of sensors and simple devices to building fully developed products for commercial use and industrial systems. You'll also work with sensors and actuators, web technologies used for communications in IoT networks, and the large-scale deployment of IoT software solutions. And see how to design these systems as well as maintain them long term. See the Raspberry Pi in a new light that highlights the true industrial potential of the device. Move beyond connecting an LED to the Raspberry Pi and making it blink to actually managing a network of IoT devices. What You'll Learn Design industrial and large scale professional Internet of Things systems Extend your basic IoT knowledge by building advanced products Learn how large scale IoT systems are deployed and maintained Who This Book Is For Advanced hobbyists who want to stretch their abilities into the professional sector. Also professional industrial engineers looking for low-cost solutions to basic IoT needs.

This open access book presents outstanding doctoral dissertations in Information Technology from the Department of Electronics, Information and Bioengineering, Politecnico di Milano, Italy. Information Technology has always been highly interdisciplinary, as many aspects have to be considered in IT systems. The doctoral studies program in IT at Politecnico di Milano emphasizes this interdisciplinary nature, which is becoming more and more important in recent technological advances, in collaborative projects, and in the education of young researchers.Accordingly, the focus of advanced research is on pursuing a rigorous approach to specific research topics starting from a broad background in various areas of Information Technology, especially Computer Science and Engineering, Electronics, Systems and Control, and Telecommunications. Each year, more than 50 PhDs graduate from the program. This book gathers the outcomes of the best theses defended in 2021-22 and selected for the IT PhD Award. Each of the authors provides a chapter summarizing his/her findings, including an introduction, description of methods, main achievements and future work on the topic. Hence, the book provides a cutting-edge overview of the latest research trends in Information Technology at Politecnico di Milano, presented in an easy-to-read format that will also appeal to non-specialists.