bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fiber‐Optic Transmission
Authors: Freeman Roger L. 
Published: November 2003

Abstract
Fiber optics as a transmission medium offers such advantages in transmission that it has become the medium of choice for both terrestrial and undersea connectivities. From several perspectives it seems to have an infinite bandwidth. Operational systems support single serial bit streams of around 10 Gbps, and 40‐Gbps systems are on the horizon. A multiplying factor up to 45‐fold is available using dense wave division multiplexing such that a single fiber can transport 10 × 45 Gbps or 450 Gbps.
Fiber‐optic links prove‐in over very long distances, typically transcontinental, and over very short distances, on the order of 300 cm (i.e., 1 ft) and anywhere in between.
A fiber‐optic link consists of a light source (i.e., transmitter), fiber‐optic cable with connectors and/or splices, and a detector (i.e., receiver). Long fiber‐optic links require intermediate repeaters. The distance between repeaters is much greater than found in coaxial cable systems, and that distance is being notably extended with the use of erbium‐doped amplifiers.
There are two basic impairments to fiber‐optic transmission: fiber loss and dispersion.
This chapter provides fiber‐optic design and application information for transmission links. Data have been included that deal with generic fiber types, sources, detectors, splices/connectors, amplifiers, wave‐division multiplex, and system design and performance. The reader should appreciate that fiber‐optic technology continues to advance very rapidly.
Radio‐Frequency Data and Regulatory Information
Authors: Freeman Roger L. 
Published: November 2003

Abstract

The electromagnetic spectrum is a natural resource of the world. To achieve optimum utilization of this resource for the public good, it is rigidly regulated. The International Telecommunication Union, based in Geneva, Switzerland, is an international regulatory agency of which nearly every nation in the world is a member and thus a signatory of its
Radio Regulations
.

The “Radio Regulations” embody the regulatory material on which each national regulatory agency (e.g., Federal Communications Commission in the United States, for example) bases its own regulations, often with refinements. The World Administrative Radio Conference (WARC) meets periodically to revise the Radio Regulations. The last WARC was in 1997.
This chapter provides basic planning information regarding the electromagnetic spectrum and its regulated usage. Sources for this chapter are the 1990 Radio Regulations, revised in 1994 with an update in 1996, data from the U.S. National Telecommunications and Information Administration, and data from the Federal Communications Commission (FCC) (1996). Much of the FCC data provided are filed in the appropriate specialty chapter.
High‐Frequency (HF) Radio Systems
Authors: Freeman Roger L. 
Published: November 2003

Abstract
From about 1920 to around 1965, HF radio was the workhorse for long‐distance telecommunication connectivity. Today it serves as an adjunct and backup for more cost‐effective, high‐availability broadband systems. In many situations it can provide a primary means of communications for the world's armed forces.
HF radio operates in the frequency band 3–30 MHz. HF propagation and transmission techniques can be readily used down to 2 MHz and below. HF can be a very economic alternative for narrow‐band, long‐distance transmission. Up to 12‐kHz bandwidth is permitted supporting four nominal 3‐kHz voice channels. However, much of the utilization of HF is based on frequency shift keying (FSK) message transmission in the range of 50–150 bps. HF circuits are used for links up to or greater than 8000 km long. Propagation availabilities range from 70% to 90% or somewhat more. HF is widely used for international propaganda broadcasts. Some countries use parts of the lower HF band (e.g., around 6 MHz) for standard broadcast. Thus, more because of typical HF skywave propagation, the HF band is rampant with interference, which probably is its number one impairment.
The objective of this chapter is to provide design data on HF systems, favoring point‐to‐point operations. In this chapter expect to find data on required signal‐to‐noise ratios, bandwidths, fade margins, propagation predictions, HF system design requirements and specifications, frequency stability implications, digital data modulation plans and waveforms, and relative level of carrier in relation to peak envelope power (PEP).
Transmission Lines and Related Devices
Authors: Freeman Roger L. 
Published: November 2003

Abstract
The assemblage of data presented in this chapter deals with transmission lines and related information. A transmission line provides the conductive transport for carrying signal power between/among system elements.
From the 1950s to about 1985, coaxial cable was a major contender for long distance signal transport (e.g., AT&T L5 transcontinental system). Fiber‐optic systems are far more feasible, do not need equalization, and have lower loss and nearly an infinite bandwidth. They have completely replaced long‐distance coaxial cable systems. Coaxial cable is widely employed for the last mile (last kilometer) or last 100 ft (30 m) of cable television systems. It is almost universally used for comparatively short run transport of RF signals (e.g, connecting transmitter/receiver to antenna). However, its use is declining in the enterprise network.
Data Transmission
Authors: Freeman Roger L. 
Published: November 2003

Abstract
The objective of this chapter is to present a collection of system‐related information on data transmission. Essentially the chapter deals with the basic, generalized physical interface (i.e., OSI layer 1) of a data circuit.

Data communications is the fastest growing segment of telecommunications. Among the several new terms appearing after 1990 is the
enterprise network
. This is a network employing data transmission that is used in the office and industrial environment consisting of local area networks (LANs) and wide area networks (WANs). The underlying technology for the physical layer of these networks is data transmission. The transmission is binary based on the bit or 1s and 0s. Of primordial interest is the speed of transmission measured in bits per second (bps) and its underlying performance measure, the
bit error rate (or ratio)
(BER).

Data transmission has evolved from telegraph transmission, technology of the 1920s. Much of the terminology used to describe data transmission derives from telegraphy terms such as FSK (frequency shift keying), ARQ (automatic repeat request) and “marks and spaces.”
A major thrust of the chapter is the data modem, a device that makes the binary DC (direct current) format of 1s and 0s compatible with an analog connectivity or compatible with the digital voice channel (the 56/64‐kbps channel) via a device called a channel service unit/digital service unit (CSU/DSU).
Community Antenna Television (CATV)
Authors: Freeman Roger L. 
Published: November 2003

Abstract
Community antenna television (CATV) has come a long way since its beginnings in the 1960s. At that time, its thrust was entertainment by providing a customer a choice of multiple TV channels with comparatively good quality pictures. It is now going through a change providing the user with a return path. In other words, the system has changed from a one‐way to a two‐way system while maintaining the capability of multiple TV channels. This new approach is well along towards maturity, where a user can simultaneously have basic plain old telephone service (POTS) telephony, megabit Internet, various two‐way data services, and TV reception.

The chapter begins with a descriptive narrative, then includes an extensive table of channel assignments. These are the standardized 6 MHz frequency slots. This is followed by a review of the Digital Video Transmission Standard for Cable Television. Then there is an overview of data over cable service interface specification (DOCSIS). Work is completed on the IEEE 802.14 specification called the Multimedia Modem Protocol. A section of the chapter briefly reviews the protocol. The
IEEE Spectrum
(May 1999) forecasts a merger between DOCSIS and 802.14 specifications. The chapter then has several subsections dealing the CATV system design issues.
Emergency and Standby Power Systems for Telecommunications
Authors: Freeman Roger L. 
Published: November 2003

Abstract
Availability is one of the most important considerations in the design of a telecommunication system. In many instances, prime power outage is the single largest contributor to the degradation of availability. In addition, many computers and processors have volatile memory and depend on a constant voltage source to keep memories alive. With the loss of prime power, volatile memories may be lost and require reloading.

This chapter treats methods of ensuring continuous power. For a single computer this may only mean a small battery pack. On the other extreme is backup, no‐break power for the entire critical load of a large telecommunications facility. Telephone switching centers are good examples of such a large facility, and it is this group that has pioneered no‐break power. The basic supply for such a facility is −48 volts of
direct current
(
DC
) derived from large banks of secondary cells. Because of this no‐break source of power, other telephone equipment also depend on −48‐VDC power, such as transmission equipment (e.g., radio relay sets, multiplex equipment).

Other installations require 110/220‐VAC or similar sources to support the critical load. Some of these installations still depend on flywheel systems where the inertia of the flywheel (connecting a motor/generator to a diesel or gasoline engine) supplies power for the several‐second interval from the loss of prime power until the diesel or gasoline engine generator cam takes up the load. The inertia in the flywheel not only keeps the generator turning, but also cranks the gasoline or diesel engine. A more modern approach is the battery‐charger system described above with the addition of an inverter to produce 110/220 VAC.

We define
reserve time
as that time the battery supply can carry the full load. Reserve time can be measured in minutes when all that is required is to bring on‐line a backup generator. It can be measured in hours — enough time for a technician to travel to a remote site to bring up a backup generator, or statistically the reasonable maximum time of a power outage.

This chapter provides the reader with the design details to assemble a backup power system with reasonable system parameters. Designing a system with excessive reserve time is costly. The amount of reserve time is a judgment call on the system designer.
Sensor Array Technology, Army
Authors: Schoess Jeffrey 
Published: November 2003

Abstract

Today's commercial and military aircraft require significant manpower to provide operational readiness and flight safety. Aging aircraft fleets are much in need of new and innovative health‐monitoring methods to prevent catastrophic failure and reduce life‐cycle costs. The key needs for characterizing

in situ

structural integrity characteristics of corrosion and barely visible impact damage (BVID) to determine “damage susceptibility” must be addressed. This article presents a new concept for onboard real‐time monitoring using conductive polymer sensor array technology.
Battery Applications
Authors: Manthiram Arumugam 
Published: November 2003

AbstractBatteries are the major power sources for portable electronic devices and toys. They are also used in automobiles for starting, lighting, and ignition (SLI batteries). At present, the worldwide battery market exceeds $30 billion per year. Rapid technological advances and miniaturization in electronics have created an ever‐increasing demand for compact, lightweight batteries. For example, popular portable electronic devices such as cellular phones, laptop computers, and camcorders require batteries of high energy density. Additionally, a need for more efficient use of available energy resources as well as air‐quality control have created enormous interest in electric vehicles. For example, the major automobile manufacturers around the globe are engaged in developing advanced batteries for electric vehicles in response to increased environmental regulations and legislative mandates. The advanced and high energy density batteries have become possible due to the discovery and development of smart materials and processes. This article, after providing a brief introduction to the basic electrochemical concepts and the principles involved in batteries, presents the materials and electrochemical aspects of high energy density (lithium‐ion) batteries.
Chemical Indicating Devices
Authors: Oriakhi Christopher O. 
Published: November 2003

AbstractMost people remember a chemical indicator from their high school chemistry. This kind of indicator is a material that changes color to signify the end point of a titration or to provide a relative indication of the acidity or alkalinity of a chemical substance. The use of indicators extends far beyond this. For example, food, cosmetic, pharmaceutical, and other chemical formulations undergo complex chemical, enzymatic, and microbial interactions when they are exposed to UV light or temperature fluctuations over time. Consequently, product quality may be degraded and may lead to additional safety concerns. The challenges facing the produce industry include successful implementation of Good Manufacturing Practices (GMP), Hazard Analysis and Critical Control Point (HACCP), Total Quality Management (TQM) programs, and other regulations that demand compliance.To address these issues and increase consumer confidence in product quality, safety, and authenticity, many manufacturers incorporate inexpensive monitoring devices into their products during production, packaging, or storage. A large number of consumer‐readable indicators are available commercially.Generally, chemical indicators may be defined as stimulus responsive materials that can provide useful information about changes in their environment. Organic dyes, hydrogels or “smart polymers,” shape‐memory alloys, thermochromic or photochromic inks, and liquid crystals are some examples. They may function by forming structurally altered ionic or molecular complexes with species in their environment through chemical or physical interactions involving proton exchange, chelation, hydrogen bonding, dipole–dipole interactions, or van der Waal forces. The resulting characteristic biochemical, chemical, optical, magnetic, thermal, or mechanical changes can be tailored to provide the desired indication response.This article focuses on inexpensive disposable chemical indicating devices such as pH indicators, temperature indicators, time–temperature indicators (TTI), and tampering and counterfeit indicators. The temperature and TTIs are widely used in the food and pharmaceutical products where date coding on a package may sometimes be inadequate.
Ceramics, Piezoelectric and Electrostrictive
Authors: Kholkin Andrei , Jadidian Bahram , Safari Ahmad 
Published: November 2003

AbstractIn a rapidly developing world, the use of smart materials becomes increasingly important when executing sophisticated functions within a designed device. In a common definition, smart materials differ from ordinary materials because they can perform two or several functions, sometimes with a useful correlation or feedback mechanism between them. For piezoelectric or electrostrictive materials, this means that the same component may be used for both sensor and actuator functions. Piezoelectric/electrostrictive sensors convert a mechanical variable (displacement or force) into a measurable electrical quantity by the piezoelectric/electrostrictive effect. Alternately, the actuator converts an electrical signal into a useful displacement or force. Typically, the term transducer is used to describe a component that serves actuator (transmitting) and sensor (receiving) functions. Because piezoelectrics and electrostrictors inherently possess both direct (sensor) and converse (actuator) effects, they can be considered smart materials. The degree of smartness can vary in piezoelectric/electrostrictive materials. A merely smart material (only sensor and actuator functions) can often be engineered into a “very smart” tunable device or further, into an “intelligent structure” whose sensor and actuator functions are intercorrelated with an integrated processing chip.Recent growth in the transducer market has been rapid and, it is predicted will continue on its current pace through the turn of the century. Piezoelectric/electrostrictive sensors and actuators comprise a significant portion of the transducer market. There is a growing trend due especially to automobile production, active vibration damping, and medical imaging. In this article, the principles of piezoelectric/electrostrictive sensors and actuators are considered along with the properties of the most useful materials and examples of successful devices.
Composites, Survey
Authors: Searles K.H. 
Published: November 2003

Abstract
The definition of a composite material, loosely translated, could point to any material having more than a single phase such that the multiple phases act in a synergistic manner to provide a behavior or set of behaviors more desirable than exhibited singularly. By this definition, a significant amount of creative space is available for scientists and engineers alike to develop exciting new materials, structures, processes, and applications to meet the demands dictated by the evolution of new technologies. As this evolution progresses, the traditional distinction made between the five classes of materials (i.e., metals, ceramics, polymers, elastomers, and glasses) tends to fade. It is here where many new possibilities arise to intelligently process and “smear” these classes together to produce new, smarter composite materials and engineering structures that “think” and respond to stimuli. The paradigm for this is by way of the tailorable structure‐performance relationships for composites based on interactions between constituent materials, which may encompass any of the five material classes.
The number of materials available to scientists and engineers for translating ideas into usable products and markets is vast, if not almost overwhelming. Current estimations give a range somewhere on the order of between 40,000 and 80,000 engineering materials. As new materials are developed having novel and exploitable characteristics (properties and responses), the number of choices further expands.
This article gives information on macroscale, microscale and mesoscale behavior of various composites. The opportunity to comprehend new theories of behavior is discussed.
Conductive Polymers
Authors: Wallace G. G. , Lewis T. W. , Kane‐Maguire L. A. P. 
Published: November 2003

AbstractIntelligent polymer systems have the capacity to sense a variety of stimuli in the operational environment. They can further process this information and then actuate responses. The stimuli utilized may be chemical (e.g., chemical imbalance in a living system) or physical (e.g., structure exceeds a stress limit). Likewise the response actuated may be chemical (e.g., controlled release of drugs) or physical (e.g., increase in stiffness of material).The intelligent polymer structure will require energy to implement these functions, so energy conversion/storage capabilities are desirable. These latter functions could be achieved, for example, by utilizing the photovoltaic properties of polymer structures. Ideally, all of the above mentioned functions would be integrated at the molecular level.While a number of classes of polymers are capable of providing one or more intelligent functions, inherently conducting polymers (ICPs) may provide all of them. Synthesis and properties of these polymers are detailed. Their use as sensors, information processors and actuators are discussed as is the possiblity of providing an energy conversion and storage stystem.
Computational Techniques for Smart Materials
Authors: Laso Manuel , Cormenzana Juan L. 
Published: November 2003

AbstractIn this article the term “design” in a rather restricted sense. Calculations, simulations, or in general to any quantitative approach necessary to specify a structure, part, mechanism, processing operation, or function, in which a smart material is used are referred to.In a large number of cases, the design with smart materials relies on well‐known and established principles of thermodynamics and continuum mechanics, such as the theories of elasticity, fluid mechanics, classical electromagnetic field theory, chemical equilibrium and kinetics, and solid state physics. These theoretical frameworks typically result in a consistent set of equations, of which at least one relates the stimulus and the response of the system. The design task consists often in specifying dimensions of structures or operating conditions of devices that guarantee satisfactory function. A typical example is the design of a smart structure that, under changes in temperature, deforms in a controlled way, possibly operating a valve or tripping a relay switch. The design of such a component, involves a straightforward application of the laws of thermoelasticity, provided that the thermomechanical properties of the material are known.The controlling principles can often be expressed as very concise and elegant partial differential equations (PDEs) that must be satisfied in domains of complicated shape that have rather involved boundary and initial conditions.In other cases, the difficult part of the design task is not the structural, fluid‐mechanical, optical or thermal design itself, but the description of the behavior of the smart material.The two main aspects in which the design and calculation for smart materials departs significantly from standard design techniques. Both aspects are intimately related to the constitutive equation (CE) or, somewhat ironically, to its nonexistence.The first aspect specific of CEs for smart materials has to do with the existence of memory effects. As a matter of fact, some of the most spectacular effects that smart materials display are related to what is somewhat vaguely called memory. Some general aspects of memory in materials and its mathematical formulation are discussed. We consider the question how to handle materials that have memory in practical calculations. Finally, the more fundamental question how to postulate a constitutive equation for smart materials is discussed. These last two sections reflect some recent developments in fields that are rapidly developing. A tentative outlook into the future of designing smart materials is presented in the closing section.