Inside NAND Flash Memories

Download Inside NAND Flash Memories PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 9048194318
Total Pages : 582 pages
Book Rating : 4.0/5 (481 download)

DOWNLOAD NOW!


Book Synopsis Inside NAND Flash Memories by : Rino Micheloni

Download or read book Inside NAND Flash Memories written by Rino Micheloni and published by Springer Science & Business Media. This book was released on 2010-07-27 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital photography, MP3, digital video, etc. make extensive use of NAND-based Flash cards as storage media. To realize how much NAND Flash memories pervade every aspect of our life, just imagine how our recent habits would change if the NAND memories suddenly disappeared. To take a picture it would be necessary to find a film (as well as a traditional camera...), disks or even magnetic tapes would be used to record a video or to listen a song, and a cellular phone would return to be a simple mean of communication rather than a multimedia console. The development of NAND Flash memories will not be set down on the mere evolution of personal entertainment systems since a new killer application can trigger a further success: the replacement of Hard Disk Drives (HDDs) with Solid State Drives (SSDs). SSD is made up by a microcontroller and several NANDs. As NAND is the technology driver for IC circuits, Flash designers and technologists have to deal with a lot of challenges. Therefore, SSD (system) developers must understand Flash technology in order to exploit its benefits and countermeasure its weaknesses. Inside NAND Flash Memories is a comprehensive guide of the NAND world: from circuits design (analog and digital) to Flash reliability (including radiation effects), from testing issues to high-performance (DDR) interface, from error correction codes to NAND applications like Flash cards and SSDs.

Flash Memories

Download Flash Memories PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9781461372783
Total Pages : 540 pages
Book Rating : 4.3/5 (727 download)

DOWNLOAD NOW!


Book Synopsis Flash Memories by : Paulo Cappelletti

Download or read book Flash Memories written by Paulo Cappelletti and published by Springer. This book was released on 2014-02-23 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Flash memory is a Non Volatile Memory (NVM) whose "unit cells" are fabricated in CMOS technology and programmed and erased electrically. In 1971, Frohman-Bentchkowsky developed a folating polysilicon gate tran sistor [1, 2], in which hot electrons were injected in the floating gate and removed by either Ultra-Violet (UV) internal photoemission or by Fowler Nordheim tunneling. This is the "unit cell" of EPROM (Electrically Pro grammable Read Only Memory), which, consisting of a single transistor, can be very densely integrated. EPROM memories are electrically programmed and erased by UV exposure for 20-30 mins. In the late 1970s, there have been many efforts to develop an electrically erasable EPROM, which resulted in EEPROMs (Electrically Erasable Programmable ROMs). EEPROMs use hot electron tunneling for program and Fowler-Nordheim tunneling for erase. The EEPROM cell consists of two transistors and a tunnel oxide, thus it is two or three times the size of an EPROM. Successively, the combination of hot carrier programming and tunnel erase was rediscovered to achieve a single transistor EEPROM, called Flash EEPROM. The first cell based on this concept has been presented in 1979 [3]; the first commercial product, a 256K memory chip, has been presented by Toshiba in 1984 [4]. The market did not take off until this technology was proven to be reliable and manufacturable [5].

3D Flash Memories

Download 3D Flash Memories PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9401775125
Total Pages : 380 pages
Book Rating : 4.4/5 (17 download)

DOWNLOAD NOW!


Book Synopsis 3D Flash Memories by : Rino Micheloni

Download or read book 3D Flash Memories written by Rino Micheloni and published by Springer. This book was released on 2016-05-26 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book walks the reader through the next step in the evolution of NAND flash memory technology, namely the development of 3D flash memories, in which multiple layers of memory cells are grown within the same piece of silicon. It describes their working principles, device architectures, fabrication techniques and practical implementations, and highlights why 3D flash is a brand new technology. After reviewing market trends for both NAND and solid state drives (SSDs), the book digs into the details of the flash memory cell itself, covering both floating gate and emerging charge trap technologies. There is a plethora of different materials and vertical integration schemes out there. New memory cells, new materials, new architectures (3D Stacked, BiCS and P-BiCS, 3D FG, 3D VG, 3D advanced architectures); basically, each NAND manufacturer has its own solution. Chapter 3 to chapter 7 offer a broad overview of how 3D can materialize. The 3D wave is impacting emerging memories as well and chapter 8 covers 3D RRAM (resistive RAM) crosspoint arrays. Visualizing 3D structures can be a challenge for the human brain: this is way all these chapters contain a lot of bird’s-eye views and cross sections along the 3 axes. The second part of the book is devoted to other important aspects, such as advanced packaging technology (i.e. TSV in chapter 9) and error correction codes, which have been leveraged to improve flash reliability for decades. Chapter 10 describes the evolution from legacy BCH to the most recent LDPC codes, while chapter 11 deals with some of the most recent advancements in the ECC field. Last but not least, chapter 12 looks at 3D flash memories from a system perspective. Is 14nm the last step for planar cells? Can 100 layers be integrated within the same piece of silicon? Is 4 bit/cell possible with 3D? Will 3D be reliable enough for enterprise and datacenter applications? These are some of the questions that this book helps answering by providing insights into 3D flash memory design, process technology and applications.

Nonvolatile Memory Technologies with Emphasis on Flash

Download Nonvolatile Memory Technologies with Emphasis on Flash PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1118211626
Total Pages : 766 pages
Book Rating : 4.1/5 (182 download)

DOWNLOAD NOW!


Book Synopsis Nonvolatile Memory Technologies with Emphasis on Flash by : Joe Brewer

Download or read book Nonvolatile Memory Technologies with Emphasis on Flash written by Joe Brewer and published by John Wiley & Sons. This book was released on 2011-09-23 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented here is an all-inclusive treatment of Flash technology, including Flash memory chips, Flash embedded in logic, binary cell Flash, and multilevel cell Flash. The book begins with a tutorial of elementary concepts to orient readers who are less familiar with the subject. Next, it covers all aspects and variations of Flash technology at a mature engineering level: basic device structures, principles of operation, related process technologies, circuit design, overall design tradeoffs, device testing, reliability, and applications.

NAND Flash Memory Technologies

Download NAND Flash Memory Technologies PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119132606
Total Pages : 432 pages
Book Rating : 4.1/5 (191 download)

DOWNLOAD NOW!


Book Synopsis NAND Flash Memory Technologies by : Seiichi Aritome

Download or read book NAND Flash Memory Technologies written by Seiichi Aritome and published by John Wiley & Sons. This book was released on 2015-12-29 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a comprehensive overview of NAND flash memories, with insights into NAND history, technology, challenges, evolutions, and perspectives Describes new program disturb issues, data retention, power consumption, and possible solutions for the challenges of 3D NAND flash memory Written by an authority in NAND flash memory technology, with over 25 years’ experience

Embedded Flash Memory for Embedded Systems: Technology, Design for Sub-systems, and Innovations

Download Embedded Flash Memory for Embedded Systems: Technology, Design for Sub-systems, and Innovations PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319553062
Total Pages : 247 pages
Book Rating : 4.3/5 (195 download)

DOWNLOAD NOW!


Book Synopsis Embedded Flash Memory for Embedded Systems: Technology, Design for Sub-systems, and Innovations by : Hideto Hidaka

Download or read book Embedded Flash Memory for Embedded Systems: Technology, Design for Sub-systems, and Innovations written by Hideto Hidaka and published by Springer. This book was released on 2017-09-09 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive introduction to embedded flash memory, describing the history, current status, and future projections for technology, circuits, and systems applications. The authors describe current main-stream embedded flash technologies from floating-gate 1Tr, floating-gate with split-gate (1.5Tr), and 1Tr/1.5Tr SONOS flash technologies and their successful creation of various applications. Comparisons of these embedded flash technologies and future projections are also provided. The authors demonstrate a variety of embedded applications for auto-motive, smart-IC cards, and low-power, representing the leading-edge technology developments for eFlash. The discussion also includes insights into future prospects of application-driven non-volatile memory technology in the era of smart advanced automotive system, such as ADAS (Advanced Driver Assistance System) and IoE (Internet of Everything). Trials on technology convergence and future prospects of embedded non-volatile memory in the new memory hierarchy are also described. Introduces the history of embedded flash memory technology for micro-controller products and how embedded flash innovations developed; Includes comprehensive and detailed descriptions of current main-stream embedded flash memory technologies, sub-system designs and applications; Explains why embedded flash memory requirements are different from those of stand-alone flash memory and how to achieve specific goals with technology development and circuit designs; Describes a mature and stable floating-gate 1Tr cell technology imported from stand-alone flash memory products - that then introduces embedded-specific split-gate memory cell technologies based on floating-gate storage structure and charge-trapping SONOS technology and their eFlash sub-system designs; Describes automotive and smart-IC card applications requirements and achievements in advanced eFlash beyond 4 0nm node.

Flash Memories

Download Flash Memories PDF Online Free

Author :
Publisher : BoD – Books on Demand
ISBN 13 : 9533072725
Total Pages : 278 pages
Book Rating : 4.5/5 (33 download)

DOWNLOAD NOW!


Book Synopsis Flash Memories by : Igor Stievano

Download or read book Flash Memories written by Igor Stievano and published by BoD – Books on Demand. This book was released on 2011-09-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flash memories and memory systems are key resources for the development of electronic products implementing converging technologies or exploiting solid-state memory disks. This book illustrates state-of-the-art technologies and research studies on Flash memories. Topics in modeling, design, programming, and materials for memories are covered along with real application examples.

Flash Memories

Download Flash Memories PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 1461550157
Total Pages : 544 pages
Book Rating : 4.4/5 (615 download)

DOWNLOAD NOW!


Book Synopsis Flash Memories by : Paulo Cappelletti

Download or read book Flash Memories written by Paulo Cappelletti and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Flash memory is a Non Volatile Memory (NVM) whose "unit cells" are fabricated in CMOS technology and programmed and erased electrically. In 1971, Frohman-Bentchkowsky developed a folating polysilicon gate tran sistor [1, 2], in which hot electrons were injected in the floating gate and removed by either Ultra-Violet (UV) internal photoemission or by Fowler Nordheim tunneling. This is the "unit cell" of EPROM (Electrically Pro grammable Read Only Memory), which, consisting of a single transistor, can be very densely integrated. EPROM memories are electrically programmed and erased by UV exposure for 20-30 mins. In the late 1970s, there have been many efforts to develop an electrically erasable EPROM, which resulted in EEPROMs (Electrically Erasable Programmable ROMs). EEPROMs use hot electron tunneling for program and Fowler-Nordheim tunneling for erase. The EEPROM cell consists of two transistors and a tunnel oxide, thus it is two or three times the size of an EPROM. Successively, the combination of hot carrier programming and tunnel erase was rediscovered to achieve a single transistor EEPROM, called Flash EEPROM. The first cell based on this concept has been presented in 1979 [3]; the first commercial product, a 256K memory chip, has been presented by Toshiba in 1984 [4]. The market did not take off until this technology was proven to be reliable and manufacturable [5].

Flash Memories

Download Flash Memories PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 9400760825
Total Pages : 268 pages
Book Rating : 4.4/5 (7 download)

DOWNLOAD NOW!


Book Synopsis Flash Memories by : Detlev Richter

Download or read book Flash Memories written by Detlev Richter and published by Springer Science & Business Media. This book was released on 2013-09-12 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this book is to introduce a model-based quantitative performance indicator methodology applicable for performance, cost and reliability optimization of non-volatile memories. The complex example of flash memories is used to introduce and apply the methodology. It has been developed by the author based on an industrial 2-bit to 4-bit per cell flash development project. For the first time, design and cost aspects of 3D integration of flash memory are treated in this book. Cell, array, performance and reliability effects of flash memories are introduced and analyzed. Key performance parameters are derived to handle the flash complexity. A performance and array memory model is developed and a set of performance indicators characterizing architecture, cost and durability is defined. Flash memories are selected to apply the Performance Indicator Methodology to quantify design and technology innovation. A graphical representation based on trend lines is introduced to support a requirement based product development process. The Performance Indicator methodology is applied to demonstrate the importance of hidden memory parameters for a successful product and system development roadmap. Flash Memories offers an opportunity to enhance your understanding of product development key topics such as: · Reliability optimization of flash memories is all about threshold voltage margin understanding and definition; · Product performance parameter are analyzed in-depth in all aspects in relation to the threshold voltage operation window; · Technical characteristics are translated into quantitative performance indicators; · Performance indicators are applied to identify and quantify product and technology innovation within adjacent areas to fulfill the application requirements with an overall cost optimized solution; · Cost, density, performance and durability values are combined into a common factor – performance indicator - which fulfills the application requirements

Channel and Source Coding for Non-Volatile Flash Memories

Download Channel and Source Coding for Non-Volatile Flash Memories PDF Online Free

Author :
Publisher : Springer Nature
ISBN 13 : 3658289821
Total Pages : 143 pages
Book Rating : 4.6/5 (582 download)

DOWNLOAD NOW!


Book Synopsis Channel and Source Coding for Non-Volatile Flash Memories by : Mohammed Rajab

Download or read book Channel and Source Coding for Non-Volatile Flash Memories written by Mohammed Rajab and published by Springer Nature. This book was released on 2020-01-02 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mohammed Rajab proposes different technologies like the error correction coding (ECC), sources coding and offset calibration that aim to improve the reliability of the NAND flash memory with low implementation costs for industrial application. The author examines different ECC schemes based on concatenated codes like generalized concatenated codes (GCC) which are applicable for NAND flash memories by using the hard and soft input decoding. Furthermore, different data compression schemes are examined in order to reduce the write amplification effect and also to improve the error correct capability of the ECC by combining both schemes.

NAND Flash Memory Technologies

Download NAND Flash Memory Technologies PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119132622
Total Pages : 432 pages
Book Rating : 4.1/5 (191 download)

DOWNLOAD NOW!


Book Synopsis NAND Flash Memory Technologies by : Seiichi Aritome

Download or read book NAND Flash Memory Technologies written by Seiichi Aritome and published by John Wiley & Sons. This book was released on 2015-12-01 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a comprehensive overview of NAND flash memories, with insights into NAND history, technology, challenges, evolutions, and perspectives Describes new program disturb issues, data retention, power consumption, and possible solutions for the challenges of 3D NAND flash memory Written by an authority in NAND flash memory technology, with over 25 years’ experience

Advances in Non-volatile Memory and Storage Technology

Download Advances in Non-volatile Memory and Storage Technology PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 0857098098
Total Pages : 456 pages
Book Rating : 4.8/5 (57 download)

DOWNLOAD NOW!


Book Synopsis Advances in Non-volatile Memory and Storage Technology by : Yoshio Nishi

Download or read book Advances in Non-volatile Memory and Storage Technology written by Yoshio Nishi and published by Elsevier. This book was released on 2014-06-24 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: New solutions are needed for future scaling down of nonvolatile memory. Advances in Non-volatile Memory and Storage Technology provides an overview of developing technologies and explores their strengths and weaknesses. After an overview of the current market, part one introduces improvements in flash technologies, including developments in 3D NAND flash technologies and flash memory for ultra-high density storage devices. Part two looks at the advantages of designing phase change memory and resistive random access memory technologies. It looks in particular at the fabrication, properties, and performance of nanowire phase change memory technologies. Later chapters also consider modeling of both metal oxide and resistive random access memory switching mechanisms, as well as conductive bridge random access memory technologies. Finally, part three looks to the future of alternative technologies. The areas covered include molecular, polymer, and hybrid organic memory devices, and a variety of random access memory devices such as nano-electromechanical, ferroelectric, and spin-transfer-torque magnetoresistive devices. Advances in Non-volatile Memory and Storage Technology is a key resource for postgraduate students and academic researchers in physics, materials science, and electrical engineering. It is a valuable tool for research and development managers concerned with electronics, semiconductors, nanotechnology, solid-state memories, magnetic materials, organic materials, and portable electronic devices. Provides an overview of developing nonvolatile memory and storage technologies and explores their strengths and weaknesses Examines improvements to flash technology, charge trapping, and resistive random access memory Discusses emerging devices such as those based on polymer and molecular electronics, and nanoelectromechanical random access memory (RAM)

Embedded Memories for Nano-Scale VLSIs

Download Embedded Memories for Nano-Scale VLSIs PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 0387884971
Total Pages : 390 pages
Book Rating : 4.3/5 (878 download)

DOWNLOAD NOW!


Book Synopsis Embedded Memories for Nano-Scale VLSIs by : Kevin Zhang

Download or read book Embedded Memories for Nano-Scale VLSIs written by Kevin Zhang and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kevin Zhang Advancement of semiconductor technology has driven the rapid growth of very large scale integrated (VLSI) systems for increasingly broad applications, incl- ing high-end and mobile computing, consumer electronics such as 3D gaming, multi-function or smart phone, and various set-top players and ubiquitous sensor and medical devices. To meet the increasing demand for higher performance and lower power consumption in many different system applications, it is often required to have a large amount of on-die or embedded memory to support the need of data bandwidth in a system. The varieties of embedded memory in a given system have alsobecome increasingly more complex, ranging fromstatictodynamic and volatile to nonvolatile. Among embedded memories, six-transistor (6T)-based static random access memory (SRAM) continues to play a pivotal role in nearly all VLSI systems due to its superior speed and full compatibility with logic process technology. But as the technology scaling continues, SRAM design is facing severe challenge in mainta- ing suf?cient cell stability margin under relentless area scaling. Meanwhile, rapid expansion in mobile application, including new emerging application in sensor and medical devices, requires far more aggressive voltage scaling to meet very str- gent power constraint. Many innovative circuit topologies and techniques have been extensively explored in recent years to address these challenges.

VLSI-Design of Non-Volatile Memories

Download VLSI-Design of Non-Volatile Memories PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 9783540201984
Total Pages : 616 pages
Book Rating : 4.2/5 (19 download)

DOWNLOAD NOW!


Book Synopsis VLSI-Design of Non-Volatile Memories by : Giovanni Campardo

Download or read book VLSI-Design of Non-Volatile Memories written by Giovanni Campardo and published by Springer Science & Business Media. This book was released on 2005-01-18 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: VLSI-Design for Non-Volatile Memories is intended for electrical engineers and graduate students who want to enter into the integrated circuit design world. Non-volatile memories are treated as an example to explain general design concepts. Practical illustrative examples of non-volatile memories, including flash types, are showcased to give insightful examples of the discussed design approaches. A collection of photos is included to make the reader familiar with silicon aspects. Throughout all parts of this book, the authors have taken a practical and applications-driven point of view, providing a comprehensive and easily understood approach to all the concepts discussed. Giovanni Campardo and Rino Micheloni have a solid track record of leading design activities at the STMicroelectronics Flash Division. David Novosel is President and founder of Intelligent Micro Design, Inc., Pittsburg, PA.

Semiconductor Memories and Systems

Download Semiconductor Memories and Systems PDF Online Free

Author :
Publisher : Woodhead Publishing
ISBN 13 : 0128209461
Total Pages : 364 pages
Book Rating : 4.1/5 (282 download)

DOWNLOAD NOW!


Book Synopsis Semiconductor Memories and Systems by : Andrea Redaelli

Download or read book Semiconductor Memories and Systems written by Andrea Redaelli and published by Woodhead Publishing. This book was released on 2022-06-07 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor Memories and Systems provides a comprehensive overview of the current state of semiconductor memory at the technology and system levels. After an introduction on market trends and memory applications, the book focuses on mainstream technologies, illustrating their current status, challenges and opportunities, with special attention paid to scalability paths. Technologies discussed include static random access memory (SRAM), dynamic random access memory (DRAM), non-volatile memory (NVM), and NAND flash memory. Embedded memory and requirements and system level needs for storage class memory are also addressed. Each chapter covers physical operating mechanisms, fabrication technologies, and the main challenges to scalability. Finally, the work reviews the emerging trends for storage class memory, mainly focusing on the advantages and opportunities of phase change based memory technologies. Features contributions from experts from leading companies in semiconductor memory Discusses physical operating mechanisms, fabrication technologies and paths to scalability for current and emerging semiconductor memories Reviews primary memory technologies, including SRAM, DRAM, NVM and NAND flash memory Includes emerging storage class memory technologies such as phase change memory

Semiconductor Memories

Download Semiconductor Memories PDF Online Free

Author :
Publisher : Wiley-IEEE Press
ISBN 13 : 9780780310001
Total Pages : 480 pages
Book Rating : 4.3/5 (1 download)

DOWNLOAD NOW!


Book Synopsis Semiconductor Memories by : Ashok K. Sharma

Download or read book Semiconductor Memories written by Ashok K. Sharma and published by Wiley-IEEE Press. This book was released on 2002-09-10 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor Memories provides in-depth coverage in the areas of design for testing, fault tolerance, failure modes and mechanisms, and screening and qualification methods including. * Memory cell structures and fabrication technologies. * Application-specific memories and architectures. * Memory design, fault modeling and test algorithms, limitations, and trade-offs. * Space environment, radiation hardening process and design techniques, and radiation testing. * Memory stacks and multichip modules for gigabyte storage.

Emerging Nanoelectronic Devices

Download Emerging Nanoelectronic Devices PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1118958268
Total Pages : 576 pages
Book Rating : 4.1/5 (189 download)

DOWNLOAD NOW!


Book Synopsis Emerging Nanoelectronic Devices by : An Chen

Download or read book Emerging Nanoelectronic Devices written by An Chen and published by John Wiley & Sons. This book was released on 2014-11-12 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging Nanoelectronic Devices focuses on the future direction of semiconductor and emerging nanoscale device technology. As the dimensional scaling of CMOS approaches its limits, alternate information processing devices and microarchitectures are being explored to sustain increasing functionality at decreasing cost into the indefinite future. This is driving new paradigms of information processing enabled by innovative new devices, circuits, and architectures, necessary to support an increasingly interconnected world through a rapidly evolving internet. This original title provides a fresh perspective on emerging research devices in 26 up to date chapters written by the leading researchers in their respective areas. It supplements and extends the work performed by the Emerging Research Devices working group of the International Technology Roadmap for Semiconductors (ITRS). Key features: • Serves as an authoritative tutorial on innovative devices and architectures that populate the dynamic world of “Beyond CMOS” technologies. • Provides a realistic assessment of the strengths, weaknesses and key unknowns associated with each technology. • Suggests guidelines for the directions of future development of each technology. • Emphasizes physical concepts over mathematical development. • Provides an essential resource for students, researchers and practicing engineers.