bluuebunny/crossref_metadata_2025_split huggingface dataset:
Television Transmission
Authors: Freeman Roger L. 
Published: November 2003

Abstract

This chapter provides standards and functional data for the design of television transmission systems for point‐to‐point and point‐to‐multipoint transport networks. It also is a source of general design data for CATV systems. The chapter also covers conference television for enterprise networks. Point‐to‐point and point‐to‐multipoint networks include transmission media, such as line‐of‐sight microwave, coaxial cable, fiber‐optic cable systems and satellite transmission serving the broadcast and CATV communities. Also included in this group are STL (
studio‐to‐transmitter link
), CATV headend extension, security, and medical image type systems.

There have been three technical thrusts in the television that were considered for inclusion in this
Manual
: digital television, television compression, and high‐definition television (HDTV). We included a brief review of the first two and did not include HDTV because it is still in a formative developmental stage. It is just not catching on with the public.

A wide disparity exists between television transmission and broadcast standards around the world. These differences appear throughout the section. A letter code is used by the ITU‐R Organization to distinguish one from another. Typically the US, for example, is given the letter code M for its NTSC system. The appropriate code letter for each of the world's countries to indicate the system type in use supplied.
Availability, Reliability, and Maintainability
Authors: Freeman Roger L. 
Published: November 2003

Abstract

Availability
is the probability that a system will operate satisfactorily at any point in time, where time includes not only operating life but also active repair time and administrative and logistic time.

This chapter deals primarily with reliability. The reader should consult the following:

MIL‐HDBK‐472,
Maintainability Prediction for methods to predict MTTR

MIL‐STD‐471A,
Maintainability Verification/Demonstration/Evaluation
.

The information in this chapter consists of abstracts from the Appendices to MIL‐HDBK‐217C,
Reliability Prediction of Electronic Equipment
[Ref.
3
].

Reliability, as discussed in this chapter, deals only with reliability of equipment and entire systems. It does not deal with propagation reliability (preferred term is “time availability“) where there might be downtime due to fading or other propagation impairment. Here the theme is equipment failure or degradation. Obviously, such a failure or degradation will affect the system to which the equipment is a functional part.
Electromagnetic Compatibility
Authors: Freeman Roger L. 
Published: November 2003

Abstract

Electromagnetic compatibility (EMC) has taken on new importance as the number of radiating devices (intentional and unintentional radiation) multiply. EMC has two aspects: emission and susceptibility.
Emission
refers to the unwanted electromagnetic energy a device generates and emits (radiates). It is often referred to as RFI or EMI.
Susceptibility
refers to the level of immunity of a device operating in a hostile environment (not in the military sense) of electromagnetic interference (both conducted and radiated) and power‐line transients.

Telecommunication systems and equipment must be designed to limit unwanted radiation and conducted interference, but they also must be designed to operate in a hostile radiation environment. With the advent of low‐level devices such as ICs, LSI, VLSI, and VHSIC (very high‐speed integrated circuits), susceptibility and emission requirements are even more stringent to prevent upset, damage, or degraded performance.
Among the most stringent specifications for EMC are those found in military systems. The basic document for these specifications is MIL‐STD‐461. Much of this chapter includes material taken from this specification. The chapter also contains FCC Part 15 regulations dealing with unintentional radiators. Such radiators (i.e., computers and other processors) are tending to corrupt our environment. It is this type of interference (noise) that is the source of much of the ingress noise on CATV systems. Ingress noise is covered.
Aircraft Control, Applications of Smart Structures
Authors: Schweiger Johannes 
Published: November 2003

AbstractProbably the most famous photograph in aviation, depicts the first successful manned powered flight on 17 December 1903 by the Wright brothers. It also shows the first successful airplane that had an active structure. The Wright brothers' design must definitely be called smart in many aspects and design features. They were among the first pioneers in aviation who had realized that uncoupled control about all three vehicle axes was required. They had done systematic experimental aerodynamic research to achieve the maximum possible aerodynamic performance. And they had learned how to design and manufacture lightweight structures in their bicycle shop. Their solution for adequate roll control of the airplane, moreover, was more than one century ahead of the state of the art in aviation technology. No single airplane exists yet that uses a smart structural concept to control the flight of the vehicle. Only in recent years, after almost one century since the first successful powered flight, was it possible to design, build, and fly vehicles powered by the human body for the sole purpose of winning trophies.For these reasons, the first successes in aviation were possible only by using design concepts for almost “rigid” surfaces and natural stability of the vehicles. Nevertheless, a major contribution to the success of the Wright brothers was their “Smart Structures” flight control system for the roll axis. They were among the first pioneers in aviation who had realized that uncoupled control about all three vehicle axes was required. They had done systematic experimental aerodynamic research to achieve maximum possible aerodynamic performance. They had a combustion engine that had sufficient energy density available “just in time,” and they had learned how to design and manufacture lightweight structures in their bicycle shop. This article discussed the use of smart materials for active structures aeroelasticity and structural concepts for aircraft control are taken into account.
Architecture
Authors: Addington D. Michelle , Schodek Daniel S. 
Published: November 2003

AbstractAn inextricable link has existed historically between a building's characteristics—form, appearance, and function—and the characteristics of the different materials that were available and suitable for construction. As exemplified by historical building traditions in stone and wood, early architects sought to understand intuitively the intrinsic physical behavior of commonly available materials to exploit their properties in designing and constructing buildings. Conversely, later innovations in the type and availability of materials strongly impacted the development of new architectural forms as architects began to respond to changing societal demands and new building functions emerged. This trend is illustrated by the development of steel in the nineteenth century and the related emergence of long‐span and high‐rise building forms. Today, architects are beginning to look forward to using the developments in smart materials to bring new solutions to long‐standing problems and also to exploit the potential of smart materials in developing new building functions, forms, and responses. The wide variety of smart materials available has great potential for use within the field, but, in this area, their applications remain only marginally explored.This article outlines and discusses smart materials in conjunction with needs currently defined in architecture. In some cases, smart materials have been proposed as replacements for conventional materials, and in other cases, smart materials have been proposed for improving the functionality of standard building systems. All of these developments can be positioned into the third category titled “Smart materials”. The impact of incorporating these materials into standard architectural practice will be significant, particularly in regard to energy use and building performance, but far more interesting potentials derive from reconsidering smart materials as fundamental conceptual elements in design rather than only as mprovements to existing elements.Several different smart materials would be involved in the development of this component, including sensors and actuators, electroluminescents or LEDS, and perhaps even shape‐memory alloys. A smart assembly would operate at the next level of functionality beyond the smart component. There are many “high‐tech” assemblies currently used in architecture. These assemblies integrate several types of components and technologies to achieve multiple functions. A smart assembly would be designed to manifest the same behaviors, but do so in the most strategic manner. Shading could be accomplished at the micron or molecular level by using smart materials, and thermal control could take place discretely and transiently by selective placement of phase change materials and thermoelectrics. The smart assembly would maximize functionality and minimize the number of components.
Biomimetic Electromagnetic Devices
Authors: Stone Morley O. , Naik Rajesh R. 
Published: November 2003

Abstract

Literally, the term
biomimetics
means to imitate life. Practically, biomimetics is an interdisciplinary effort aimed at understanding biological principles and then applying those principles to improve existing technology. This approach can mean changing a design to match a biological pattern, or it can mean actually using biological materials, for example, proteins, to improve performance. Biomimetics had its earliest and strongest footholds in materials science, and it is rapidly spreading to areas such as electromagnetic sensors and computer science.

The area of biomimetics covered in this article applies to sensing electromagnetic (EM) radiation. Volumes have been written regarding how higher organisms perceive visible light, and thus, this will be largely ignored here. Mostly, coverage is limited to biological sensing of EM radiation on either side of the visible, the ultraviolet, and the infrared. From a biological sensing perspective, spectral regions are defined as follows: near‐ultraviolet wavelengths (λ) from 200–400 nm and infrared wavelengths from 0.75–15 µm. Operationally, both the ultraviolet and infrared extend over larger wavelength intervals. This article outlines some of the electromagnetic detection/sensitive systems in biology.
Fiber Optics, Bragg Grating Sensors
Authors: Measures Raymond M. 
Published: November 2003

AbstractThe unique properties of fiber‐optic Bragg gratings are leading to many exciting applications in both the telecommunication and sensing fields. Afiber Bragg grating(FBG) is formed when a periodic variation of the index of refraction is created along a section of the core of the optical fiber by exposing the fiber to an interference pattern of intense UV‐laser light. The formation of permanent Bragg gratings in an optical fiber was first demonstrated in 1978 and results from the photosensitivity of the core of certain optical fibers. The special properties of FBGs that make them attractive as structural sensors are their very narrow reflection spectrum and the dependence of this reflection wavelength on the local strain state of the optical fiber. A broad review of FBGs has been provided, and comprehensive overviews of the application of FBGs to the telecommunication and structural sensing fields can be found in the recent books (3) and (4), respectively.
Gels
Authors: Lowman Anthony M. , Dziubla Thomas D. 
Published: November 2003

AbstractHydrogels are three‐dimensional, water‐swollen structures composed mainly of hydrophilic homopolymers or copolymers. They are rendered insoluble by chemical or physical cross‐links. The physical cross‐links can be entanglements, crystallites, or weak associations such as van der Waals forces or hydrogen bonds. Cross‐links provide the network structure and physical integrity. It is possible to design hydrogels whose swelling behavior depends on the external environment. During the last thirty years, there has been significant interest in the development and analysis of environmentally or physiologically responsive hydrogels.Hydrogels are classified in a number of ways. They can be neutral or ionic based on the nature of the side groups. They can also be classified on the basis of network morphology as amorphous, semicrystalline, hydrogen‐bonded structures; supermolecular structures; and hydrocolloidal aggregates. Additionally, in terms of their network structures, hydrogels can be classified as macroporous, microporous, or nonporous. In this article, an overview of smart hydrogels and models that characterize the structure and properties of these materials are presented. Additionally, important contributions in this area and new synthetic methods that promise to lead to the development of exciting new structures for solutions to drug delivery problems are reviewed.
Intelligent Processing of Materials (IPM)
Authors: Güemes J. A. , Rodriguez‐Lence F. , Menendez J. M. 
Published: November 2003

Abstract
Intelligent materials processing (IMP) is achieved by the integration of on‐line sensors, process models, and adaptive control strategies. So formed, the system will be able to adjust the process parameters during production in response to changes in a material's state and thus to achieve the desired end‐use properties.
Metal welding is an example of this off‐line control procedure. To make the metal welding process “intelligent,” one would need to have sensors that not only control the electrodes' voltage and the welding speed—as is done in conventional processing—but also sensors that collect data continuously from the material in the molten area. A computer‐based model would be used to predict the final microstructure based on the values of the monitored variables and the control parameters' setting. The system then would predict how to modify the control parameters during the subsequent steps of the process in order to achieve the desired microstructure. Although technology has yet been able to produce such an “intelligent welding machine” to replace the skilled operator, despite the difficulties, this is an ongoing project of the Weld Process Sensing, Modeling, and Control program sponsored by NIST.

The simple welding example helps identify the two main issues that need to be addressed in order to implement “intelligent processing” in any material:

Availability of reliable sensors to monitor the process variables. The sensors must not disturb the processing environment.

Full understanding of the process, the interdependence among the process variables that can be sensed and the process parameters that can be controlled in order to achieve predictive capability in the new material.

It must be emphasized that “intelligent processing” is not the same as “automated processing,” but a step ahead.

The major benefit of intelligent processing is that this reduces the time spent in moving a design from the project desk into production.
The more ambitious focus of materials process research concerns the use of self‐directed computer‐aided systems to establish in‐situ self‐improvement of the design and control of materials processing.
The general points discussed here apply to any engineering material, and industrial examples may be found in every technological area, from polymers to metals, ceramics, and composites.
Microrobotics, Microdevices Based on Shape‐Memory Alloys
Authors: Bellouard Yves 
Published: November 2003

AbstractFor the past few years, consumer products such as computers, mobile phones, and cameras have drastically decreased in size and their functionalities have increased. In addition, mini‐invasive techniques in surgery have led to a growing need for small, highly reliable components that can go through arteries or veins. In general, there are nearly no highly technological products that do not benefit from miniaturization. However, one cannot simply scale down electrical or mechanical components from “macroscale” because physical forces do not scale down at the same amplitude. Therefore, the efficiency of actuators depends on their size. Consequently, there is a need for new actuating technologies adapted to the microworld that can replace usual actuators such as electromagnetic motors. Among these technologies, smart materials such as piezoceramics, magnetostrictive, electrostrictive, and shape‐memory materials are of particular interest. This article describes the use of shape‐memory alloys (SMA) for microengineering applications.A brief description of SMA properties is given. Some usual design principles are addressed. A literature survey and a concept of monolithic microdevices concludes the article.
Microtubes
Authors: Hoffman Wesley P. , Wapner Phillip G. 
Published: November 2003

AbstractMicrotubes are very small diameter tubes (in the nanometer and micron range) that have very high aspect ratios and can be made from practically any material in any combination of cross‐sectional and axial shape desired. In smart structures, these microscopic tubes can function as sensors and actuators, as well as components of fluidic logic systems. In many technological fields, including smart structures, microtube technology enables fabricating components and devices that have, to date, been impossible to produce, offers a lower cost route for fabricating some current products, and provides the opportunity to miniaturize numerous components and devices that are currently in existence.Microtubes appear to have almost universal application in areas as diverse as optics, electronics, medical technology, and microelectromechanical devices. The technology works equally well for high‐ and low‐temperature materials and appears feasible for all applications that have been conceived to date.The advantage of microtube technology is that tubes can be fabricated inexpensively from practically any material in a variety of cross‐sectional and axial shapes in very precise diameters, compositions, and wall thicknesses of orders of magnitude smaller than is now possible. In contrast to the other micro‐ and nanotube technologies currently being developed, microtubes can be made from a greater range of materials in a greater range of lengths and diameters and far greater control over the cross‐sectional shape. These tubes will provide the opportunity to miniaturize (even to nanoscale dimensions) numerous products and devices that currently exist, as well as allowing the fabrication of innovative new products that have to date been impossible to produce.Here allows presenting one application of microtube technology to new innovative products in greater detail.
Paints
Authors: Egusa Shigenori 
Published: November 2003

AbstractPaints are used everywhere in an industrialized society. The most important functions of paints are protection and decoration of a substrate.Smart paints are an innovative type of paint that has a sensor function as well as the protective and decorative functions of conventional paints. Smart paints can detect abnormal vibration of a structural material by monitoring the natural frequencies and mode shapes of the material. They can also detect damage generated in the material by monitoring the acoustic emission (AE) wave traveling from the damage location to the material surface. Vibration and AE can be monitored in real time, thus enabling health monitoring of the material even during operation.Smart paints are used in large‐scale structures such as vehicles operated at high speeds, civil infrastructures of huge mass and volume, and special facilities that contain large amounts of petroleum, nuclear fuel, and explosive substances. Smart paints can possibly prevent a disaster by warning of abnormal vibration and damage generated in a structural material.The frequency of health monitoring needed for structural materials increases steadily as age increases because the corrosion of steel and concrete progresses gradually during the service period of several decades. Smart paints can be applied to a structural material at any time before and after the construction of the structure, thus making health monitoring quite, easy even for a structure already in active service. Smart paints can make a significant contribution to increasing the service life of a structure, and consequently to saving natural resources.
Poly(p‐phenylenevinylene)
Authors: Wolf Michael O. 
Published: November 2003

AbstractPoly(p‐phenylenevinylene) (PPV) and its derivatives are polymers that have been widely studied due to their potential applications in optoelectronic devices. PPV is a conjugated polymer whose backbone consists of alternating single and double bonds. Many conjugated polymers are known and exhibit remarkably high electrical conductivities when oxidatively or reductively doped. Much of the early research on PPV focused on the relatively disappointing properties of the doped material; however, interest in this material was reawakened in 1990 when it was discovered that films of undoped PPV could be used as the emitting layer in organic electroluminescent (EL) devices. This discovery stimulated intense research in the area, including many fundamental studies of the properties of PPV and its derivatives, and extensive academic and industrial interest in the applications of the materials.This article provides an overview of the methods by which PPV and some of its derivatives may be prepared, the physical and electronic properties of these materials, and the applications that are being explored. Several excellent and comprehensive reviews which have been published on the synthesis, properties, and applications of PPV and these are noted.
Magnets, Organic/Polymer
Authors: Miller Joel S. , Epstein Arthur J. 
Published: November 2003

AbstractMagnetism has enabled the development and exploitation of fundamental science, ranging from quantum mechanics, to probing condensed matter chemistry and physics, to materials science. The control of magnetism has resulted in the availability of low‐cost electricity and the use of electric motors, leading to the development of telecommunications devices (microphones, televisions, telephones, etc.), and to magnetic storage for computers. Magnets, due to their myriad properties, are suitable components in sensors and actuators, and hence they must be considered the key components in smart materials and systems of the future.Magnetic materials known from time immemorial are comprised of either transition or rare‐earth metals, or their ions with spins residing in d‐ or f‐orbitals, respectively, such as Fe, CrO2, SmCo5, Co17Sm2, and Nd2Fe14B. These materials are prepared by high‐temperature metallurgical methods, and generally, they are brittle. In the late twentieth century many metal and ceramic materials were replaced with lightweight polymeric materials. The polymeric materials were designated primarily for structural materials, but examples also abound for electrically conducting and optical materials. More recently, new examples of magnetic materials have been reported. Undoubtedly, in this millennium there will be commercialization of these organic and polymeric magnets.