Showing papers on "Personal computer published in 1998"

Space Vehicle Dynamics and Control

Abstract: "Space Vehicle Dynamics and Control, Second Edition" continues to provide a solid foundation in dynamic modeling, analysis, and control of space vehicles featuring detailed sections covering the fundamentals of controlling orbital, attitude, and structural motions of space vehicles. A new Part 5 is a collection of advanced spacecraft control problems and their practical solutions obtained by applying the fundamental principles and techniques emphasized throughout the book.The textbook highlights a range of orbital maneuvering and control problems: orbital transfer, rendezvous, and halo orbit determination and control. Rotational maneuvering and attitude control problems of space vehicles under the influence of reaction jet firings, internal energy dissipation, or momentum transfer via reaction wheels and control moment gyros are treated in detail. It also covers the analysis and design of attitude control systems in the presence of structural flexibility and/or propellant sloshing. New topics include control moment gyros for agile imaging satellites, solar sail dynamics and control, solar sail missions for asteroid deflection, and attitude and orbit control of a large geostationary solar power satellite.This text requires a thorough knowledge of vector and matrix algebra, calculus, ordinary differential equations, engineering mechanics, and linear system dynamics and control. The first two chapters provide a summary of such necessary background material. Since some problems may require the use of software for the analysis, control design, and numerical simulation, readers should have access to computational software (i.e., MATLAB[registered]) on a personal computer. MATLAB is a registered trademark of The MathWorks, Inc.

Integrated routing/mapping information

Abstract: An Integrated Routing/Mapping Information System (IRMIS) links desktop personal computer cartographic applications to one or more handheld organizer, personal digital assistant (PDA) or “palmtop” devices. Such devices may be optionally equipped with, or connected to, portable Global Positioning System (GPS) or equivalent position sensing device. Desktop application facilitates user selection of areas, starts, stops, destinations, maps and/or point and/or route information. It optionally includes supplemental online information, preferably for transfer to the PDA or equivalent device. Users' options include route information, area, and route maps. Maps and related route information are configured with differential detail and levels of magnitude. Used in the field, in conjunction with GPS receiver, the PDA device is configured to display directions, text and map formats, the user's current position, heading, speed, elevation, and so forth. Audible signals identifying the next turn along the user's planned route are also provided. The user can pan across maps and zoom between two or more map scales, levels of detail, or magnitudes. The IRMIS also provides for “automatic zooming,” e.g., to show greater detail or closer detail as the user approaches a destination, or to larger scale and lower resolution to show the user's overall planned route between points of interest. The IRMIS also enables the user to mark or record specific locations and/or log actual travel routes, using GPS position information. These annotated location marks and/or “breadcrumb” or GPS log data can be saved, uploaded, displayed, or otherwise processed on the user's desktop geographic information or cartographic system. The IRMIS application and data may be distributed online and/or in tangible media in limited and advanced manipulation formats.

Method and apparatus using geographical position and universal time determination means to provide authenticated, secure, on-line communication between remote gaming locations

Abstract: Method and apparatus for providing authenticated, secure, on-line communication between remote locations including a user terminal adapted to enable a player in one location to remotely communicate via a communications medium such as the Internet with a gaming host in another location. Location of the remote user terminal, the host server and universal time are determined using means for accessing signals generated by geostationary navigational transmitters, such as in the global positioning satellite (GPS) system. Player authentication (identity verification) is determined by use of a personal identification number (PIN) and an electronic signature verification service. Security of communication is accomplished through use of a public-key/private-key encryption system. The remote user terminal may be comprised of one or more discreet components adapted to be used with a laptop or desktop personal computer (PC), or may be embodied in a stand alone or self-contained single unit that is portable and communicates via radio waves, telephone lines or the Internet to a host server.

Interpretation of measured concentration profiles in sediment pore water

Abstract: A robust numerical procedure for biogeochemical interpretation and analysis of measured concentration profiles of solutes in sediment pore water has been developed. Assuming that the concentration-depth profile represents a steady state, the rate of net production or consumption as a function of depth can be calculated, together with the flux across the sediment-water interface. Three kinds of vertical transport can be included in the analysis: molecular diffusion, bioturbation, and irrigation. The procedure involves finding a series of least square fits to the measured concentration profile, followed by comparisons of these fits through statistical F-testing. This approach leads to an objective selection of the simplest production-consumption profile that reproduces the concentration profile. Because the numerical procedure is optimized with respect to speed, one prediction can typically be done in a few minutes or less on a personal computer. The technique has been tested successfully against analytical solutions describing the transport and consumption of 0, in sediment pore water. In other tests, measured concentration profiles of O,, NO;, , NH:, and ZCO, have been interpreted using the new procedure.

The Invisible Computer: Why Good Products Can Fail, the Personal Computer Is So Complex, and Information Appliances Are the Solution

Abstract: From "Science Finds, Industry Applies, Man Conforms" (motto of the 1933 Chicago USA World's Fair)-to "People Propose, Science Studies, Technology Conforms" (Donald Norman's person-centered motto for the twenty-first centuray). Technologies have a life cycle, says Donald Norman, and companies and their products must change as they pass from youth to maturity. Alas, the computer industry thinks it is still in its rebellious teenage years, exulting in technical complexity. Customers want change. They are ready for products that offer convenience, ease of use, and pleasure. The technology should be invisible, hidden from sight. In this book, Norman shows why the computer is so difficult to use and why this complexity is fundamental to its nature. The only answer, says Norman, is to start over again, to develop information appliances that fit people's needs and lives. To do this companies must change the way they develop products. They need to start with an understanding of people: user needs first, technology last-the opposite of how things are done now.

Personal computer card for collection of real-time biological data

Abstract: A real-time biological data processing PC card is very lightweight, cost effective, and portable. The real-time biological data processing PC card is capable of converting a host personal computer system (27) into a powerful diagnostic instrument. Each real-time biological data processing PC card is adapted to input and process biological data from one or more biological sensors (21), and is interchangeable with other real-time biological data processing PC cards. A practitioner having three different biological data collection devices, effectively carries three full sized, powerful diagnostic instruments. The full resources of a host personal computer (27) can be utilized and converted into a powerful diagnostic instrument, for each biological data collection device by the insertion of one of the real-time biological data processing PC cards.

Patterns and Meanings: Using corpora for English language research and teaching

Abstract: Patterns and Meanings consists of case studies which make use of corpora and concordance technology. Each case study elaborates a problem area, makes reference to both the descriptive and applied literature thus far, and then suggests ways of exploiting corpus data to shed light on the problem. Language phenomena investigated include word sense, phraseology and syntax, metaphor and creative use, text reference, idiom, and translation. Emphasis is given to information that usually cannot be found in dictionaries, grammars, language textbooks or other resources, but which the study of corpus data makes available. This work is particularly important not only for its language description insights, but also for pedagogical application. Further useful suggestions are included on setting up a medium-sized corpus on a personal computer.

Deinterlacing-an overview

Abstract: The question "to interlace or not to interlace" divides the television and the personal computer communities. A proper answer requires a common understanding of what is possible nowadays in deinterlacing video signals. This paper outlines the most relevant proposals, ranging front simple linear methods to advanced motion-compensated algorithms, and provides a relative performance comparison for 12 of these methods. Next to objective performance indicators, screen photographs have been used to illustrate typical artifacts of individual deinterlacers. The overview provides no final answer in the interlace debate, as such requires unavailable capabilities in balancing technical and nontechnical issues.

Catalogue of Diagnostic X-Ray Spectra and Other Data

Abstract: The original version of the Catalogue, SRS-30 published by Birch, Marshall and Ardan in 1979, contained essential data for physicists working in diagnostic radiology and mammography. The aim of this publication is to include and enhance much of the original data by providing a wider range of x-ray photon spectra. With the increased availability of desktop computing and the use of spectral data in computer modelling applications, the publication is also intended to provide the data in a more accessible form on CD-ROM. The compact disk contains a set of over 4000 data files and includes basic sets of unattenuated radiographic x-ray spectra from tungsten targets for tube potentials with sinusoidal waveform ripple and constant potential. Constant potential mammographic x-ray spectra from molybdenum and rhodium targets are also provided. The spectra have been calculated using the same theoretical method of Birch and Marshall but with up-to-date attenuation coefficients. All spectra have been provided at energy steps of 0.5 keV rather than at 1 keV intervals which were used in SRS-30. The attenuation coefficients are provided for various materials as are photon to kerma conversion factors for air, adipose tissue, skeletal muscle and bone. A useful tool provided on the CD-ROM is the Spectral Processor program. This allows spectral files to be processed and saved for future use. By selecting a spectral file and specifying the type and thickness of one of the displayed attenuating materials, calculations are made of the mean photon energy, the air kerma ( at 750 mm) and the first HVL of the filtered spectrum. A plot of the spectrum is also displayed. The spectral files may also be used as input to the user's personal computer programs. Other data provided on the CD-ROM include data for estimating x-ray tube filtration. The data in this set of files, when plotted, present HVL to total filtration graphs similar to those provided in Data for Estimating X-ray Tube Total Filtration (IPSM 64). One useful addition is that data are provided at target angles from to in increments rather than in steps of . Mammographic data for estimating x-ray tube filtration are also provided and include the data published in Commissioning and Routine Testing of Mammographic x-ray Systems (IPSM 59 [2nd edition]). The CD-ROM also contains explanatory text on what factors affect the spectrum shape, how the spectral data were calculated, how the data compare with SRS-30 and how the data should be used for estimating tube total filtration. A summary on how all the data are presented on the CD-ROM is also provided. A listing of a sample computer program for attenuating spectra is also included as an appendix. With its up-to-date spectral data, convenient data format and excellent on-line documentation, this publication will be a useful and effective tool for many scientists.

Real-Time Automated Detection and Quantitative Analysis of Seizures and Short-Term Prediction of Clinical Onset

Abstract: Summary: Purpose: We describe an algorithm for rapid realtime detection, quantitation, localization of seizures, and prediction of their clinical onset. Methods: Advanced digital signal processing techniques used in time-frequency localization, image processing, and identification of time-varying stochastic systems were used to develop the algorithm, which operates in generic or adaptable “modes.” The “generic mode” was tested on (a) 125 partial seizures (each contained in a 10-min segment) involving the mesial temporal regions and recorded using depth electrodes from 16 subjects, and (b) 205 ten-minute segments of randomly selected interictal (nonseizure) data. The performance of the algorithm was compared with expert visual analysis, the current “gold standard.” Results: The generic algorithm achieved perfect sensitivity and specificity (no false-positive and no false-negative detections) over the entire data set. Seizure intensity, a novel measure that seems clinically relevant, ranged between 35.7 and 6129. Detection was sufficiently rapid to allow prediction of clinical onset in 92% of seizures by a mean of 15.5 s. Conclusions: This algorithm, which was implemented with a personal computer, represents a definitive step toward rapid and accurate detection and prediction of seizures. It may also enable development of intelligent devices for automated seizure warning and treatment and stimulate new study of the dynamics of seizures and of the epileptic brain.

Electronic book with automated look-up of terms of within reference titles

Abstract: An electronic reading system is disclosed which allows users to download books and other types of content to a hand-held reader device for viewing. Using software which runs on a personal computer (PC), the user can download titles from Internet sites to the PC. Titles are then automatically transferred to the device when the device is placed in a cradle which is connected to the PC. Using the device's touch-sensitive display and graphical user interface, the user can access various software-implemented features associated with the display and management of the content. One feature is a user-definable hotkey that can be “dragged and dropped” onto a menu item to create a shortcut to that item. Another feature allows the user to tap twice on a displayed word to cause the device to look the word up in a pre-specified or default reference title, such as a dictionary or an encyclopedia. Another feature allows the user to block a passage on the touch-sensitive display and then specify one or more destinations (email addresses, file folders, fax numbers, printers, etc.) for routing the passage; when the device is subsequently placed in the cradle, the passage is automatically retrieved by the PC and routed to the specified destination(s). The device also implements a user interface feature for allowing the user to rapidly and conveniently adjust the orientation of the displayed title.

A Practical Implementation of the Timing Attack

Abstract: When the running time of a cryptographic algorithm is non-constant, timing measurements can leak information about the secret key. This idea, first publicly introduced by Kocher, is developed here to attack an earlier version of the CASCADE smart card. We propose several improvements on Kocher’s ideas, leading to a practical implementation that is able to break a 512-bit key in few hours, provided we are able to collect 300000 timing measurements (128-bit keys can be recovered in few seconds using a personal computer and less than 10000 samples). We therefore show that the timing attack represents an important threat against cryptosystems, which must be very seriously taken into account.

Two-way communications between a remote control unit and one or more devices in an audio/visual environment

Abstract: A remote control unit in an audio/visual system has a two-way communications link with one or more audio/visual devices The bi-directional flow of information between the remote control unit and the audio/visual device(s) provides for the creation of remote control commands that are customized based upon the characteristics of the particular A/V device being controlled by the remote control unit The remote control unit may additionally have another two-way communications link with one or more information-providing devices, such as a personal computer capable of accessing the Internet, that can provide the remote control unit with information available outside the audio/visual environment The bi-directional flow of information of the two-way communications links is accomplished with a two-way infra-red link or a two-way serial link

Unleashing the Killer App: Digital Strategies for Market Dominance

Abstract: From the Publisher: When technologies, products, and services converge in radical, creative new ways, a 'killer app' can emerge -- a new application so powerful that it transforms industries, redefines markets, and annihilates the competition. The compass, the steam engine, the cotton gin, and the Model T were all killer apps that sent shock waves through the social, political, and economic systems of their time. Today's killer apps spring from the digital realm: the personal computer, e-mail, and the World Wide Web have profoundly influenced and even altered society far beyond their intended use. Tempted by the promise of such devastating power, companies large and small, from vast multinationals to lean entrepreneurial start-ups, are remaking themselves into organizations that nurture killer apps rather than succumb to them. With Unleashing the Killer App, Downes and Mui offer a progressive guide to transforming your company into a place where killer apps are born. Drawing from their experience and research with leading global businesses, the authors identify the 12 fundamental design principles for building killer apps; illustrate these principles with classic stories from history and examples from a wide range of industries that have successfully developed killer apps; examine the economic consequences of the diminishing transaction costs in cyberspace; and describe how to integrate digital strategy into an organization's planning process to create new markets, form new customer relationships, and change the product line.

Information security awareness: educating your users effectively

Abstract: This article investigates the evolution of computing, with specific reference to the security issues involved. These issues are then taken further to determine the need for education in the workplace through an information security awareness program. Techniques borrowed from the field of social psychology, which have been largely ignored in current awareness programs, are highlighted in order to show how they could be utilized to improve the effectiveness of the awareness program.

Method and system for advertising on personal computers

Abstract: An advertising system for a personal computer (PC) stores an advertising message as part of software which has been installed after its purchase from a software vendor. The message is presented to the user only during waiting times when documents derived from the PC are being printed.

Remote control device with a graphical user interface

Abstract: A two-way remote control unit with a graphical user interface controls various audio/video devices interconnected in a multimedia system. The remote control unit includes a transceiver for transmitting and receiving control commands to/from multimedia components, which are displayed in the user-friendly format on a display of the remote control unit. The user can scroll, select, browse, etc. through various menu items on the display, and activate any desired function on the multimedia system component by selecting the desired representation of that function on the display. In addition, the remote control unit communicates, also through wireless transmission, with a personal computer and obtains information from remote or local databases for either controlling or enhancing the operation of the multimedia system devices.

Method for creating, modifying, and playing a custom playlist, saved as a virtual CD, to be played by a digital audio/visual actuator device

Abstract: A custom playlist to be played by a digital audio/visual actuator device may be easily created and modified through use of an effective human interface on an external device, such as a personal computer. Tracks, easily identifiable by their track index identifier and the TOC of the digital storage device on which they are stored, are selected by the user or by an automated method and added to a playlist file. Once the playlist is created, the playlist file is stored to non-volatile memory of the digital audio/visual actuator device. The playlist may then be easily modified if so desired by performing such functions as adding tracks, deleting tracks, and rearranging tracks of the playlist through the interface of the external device. The playlist may be played by the digital audio/visual actuator device at any time after it has been created and the digital audio/visual actuator device may be controlled by a remote control unit to actuate the playlist if so desired.

A real-time experimental prototype for enhancement of vision rehabilitation using auditory substitution

Abstract: The rehabilitation of blindness, using noninvasive methods, requires sensory substitution. A theoretical frame for sensory substitution has been proposed (C. Veraart, 1989) which consists of a model of the deprived sensory system connected to an inverse model of the substitutive sensory system. This paper addresses the feasibility of this conceptual model in the case of auditory substitution, and its implementation as a rough model of the retina connected to an inverse linear model of the cochlea. The authors have developed an experimental prototype. It aims at allowing optimization of the sensory substitution process. This prototype is based on a personal computer which is connected to a miniature head-fixed video camera and to headphones. A visual scene is captured. Image processing achieves edge detection and graded resolution. Each picture element (pixel) of the processed image is assigned a sinusoidal tone; weighted summation of these sinewaves builds up a complex auditory signal which is transduced by the headphones. On-line selection of various parameters and real-time functioning of the device allow optimization of parameters during psychophysical experimentations. Assessment of this implementation has been initiated, and has so far demonstrated prototype usefulness for pattern recognition. An integrated circuit of this system is to be developed.

Apparatus and method for recapture of realtime events

Abstract: An apparatus and method for providing a video or audio record of a predetermined activity close in time to a preselected triggering event comprising a video or audio detection apparatus, control circuitry for developing a stream of electronic data representing a continuous sequence of audio or video images in real time, a circular data storage buffer for receiving the data in real time, an event detection mechanism for sensing occurrence of the predetermined triggering event so as to cause the control circuitry to freeze the contents of the circular buffer at some time adjacent to the occurrence of the triggering event, and means for downloading the stored data to a means for perceiving it such as a personal computer.

Exploring personal computer adoption dynamics

Abstract: As the personal computer's capability to function as an interactive multimedia entertainment and information provider increases, the implications of its future development on the print, broadcast, and cable television industries are of great interest to society. This study visits the most important question facing the personal computer phenomenon at present— adoption—by examining adoption rate and adopter types and their relations to potential adoption barriers, media use patterns, existing communication technology ownership and social locators. Even though the study provided only an exploratory examination of the proposed model, the findings offer a reasonable level of support for the theoretical framework outlined.

A global computer software for polymer flows in corotating twin screw extruders

Abstract: A global computation model for self-wiping corotating twin screw extruders is proposed. Based on a 1D approximated approach, it has been validated by comparison with experimentation and more sophisticated numerical models. It allows one to obtain, for any screw profile including left-and right-handed screw elements and kneading discs, the profile along the screws of the main flow variables, such as pressure, mean temperature, residence time, and filling ratio. Owing to the approximations made, this model can be easily and rapidly run on a personal computer or a workstation. Important applications may be found in screw profile design, scaleup, compounding or reactive extrusion.

Optical CT reconstruction of 3D dose distributions using the ferrous-benzoic-xylenol (FBX) gel dosimeter.

Abstract: In recent years, magnetic-resonance imaging of gelatin doped with the Fricke solution has been applied to the direct measurement of three-dimensional (3D) radiation dose distributions. However, the 3D dose distribution can also be imaged more economically and efficiently using the method of optical absorptioncomputed tomography. This is accomplished by first preparing a gelatin matrix containing a radiochromic dye and mapping the radiation-induced local change in the optical absorption coefficient. Ferrous–Benzoic–Xylenol (FBX) was the dye of choice for this investigation. The complex formed by Fe 3+ and xylenol orange exhibits a linear change in optical attenuation ( cm −1 ) with radiation dose in the range between 0 and 1000 cGy, and the local concentration of this complex can be probed using a green laser light (λ=543.5 nm). An optical computed tomography(CT) scanner was constructed analogous to a first-generation x-rayCT scanner, using a He–Ne laser, photodiodes, and rotation–translation stages controlled by a personal computer. The optical CT scanner itself can reconstructattenuation coefficients to a baseline accuracy of 2% while yielding dose images accurate to within 5% when other uncertainties are taken into account. Optical tomography is complicated by the reflection and refraction of light rays in the phantom materials, producing a blind spot in the transmission profiles which, results in a significant dose artifact in the reconstructed images. In this report we develop corrections used to reduce this artifact and yield accurate dosimetric maps. We also report the chemical reaction kinetics, the dose sensitivity and spatial resolution (<1 mm3) obtained by optical absorptioncomputed tomography. The article concludes with sample dose distributions produced by “cross-field” 6 MV x-ray beams, including a radiosurgery example.

Apparatus and methods relating to optical systems for diagnosis of skin diseases

Abstract: Apparatus for diagnosis of a skin disease site using spectral analysis includes a light source for generating light to illuminate the disease site and a probe unit optically connected to the light source for exposing the disease site to light to generate fluorescence and reflectance light. The probe unit also collects the generated fluorescence and reflectance light and transmits this light to a spectrometer to be analyzed. The spectrometer generates and displays spectral measurements of the fluorescence light and the reflectance light which in together assist the user in diagnosing the disease site. The apparatus makes use of a conventional personal computer using a plug-in spectrometer card to provide a compact and low costs system. The system performs combined fluorescence and reflectance spectral analysis in a quick and efficient manner to provide a powerful tool for dermatologic diagnosis.

Citation selection and routing feature for hand-held content display device

Abstract: An electronic reading system is disclosed which allows users to download books and other types of content to a hand-held reader device for viewing. Using software which runs on a personal computer (PC), the user can download titles from Internet sites to the PC. Titles are then automatically transferred to the device when the device is placed in a cradle which is connected to the PC. Using the device's touch-sensitive display and graphical user interface, the user can access various software-implemented features associated with the display and management of the content. One feature is a user-definable hotkey that can be “dragged and dropped” onto a menu item to create a shortcut to that item. Another feature allows the user to tap twice on a displayed word to cause the device to look the word up in a pre-specified or default reference title, such as a dictionary or an encyclopedia. Another feature allows the user to block a passage on the touch-sensitive display and then specify one or more destinations (email addresses, file folders, fax numbers, printers, etc.) for routing the passage; when the device is subsequently placed in the cradle, the passage is automatically retrieved by the PC and routed to the specified destination(s). The device also implements a user interface feature for allowing the user to rapidly and conveniently adjust the orientation of the displayed title.

Fast address look-up for internet routers

Abstract: We consider the problem of organizing address tables for internet routers to enable fast searching. Our proposal is to to build an efficient, compact and easily searchable implementation of an IP routing table by using an LC-trie, a trie structure with combined path and level compression. The depth of this structure increases very slowly as function of the number of entries in the table. A node can be coded in only four bytes and the size of the main search structure never exceeds 256 kB for the tables in the US core routers. We present a software implementation that can sustain approximately half a million lookups per second on a 133 MHz Pentium personal computer, and two million lookups per second on a more powerful SUN Sparc Ultra II workstation.

Strategic supply chain alignment : best practice in supply chain management

Abstract: Contents: Foreword - Gregory Owens Introduction - John Gattorna New approaches to strategy - Peter Fuchs, Andrew Young and Alida Zweidler-McKay Strategic supply chain management - Robert Evans and Alister Danks. Part I The Market: Overview Creating Customer Value: Aligned logistics operations - Liane Torres and John Miller Customer support logistics - Robert Evans and Doug Castek Postponement for mass customization - Hau Lee Integrating Supply with Demand: The supply-demand nexus - Jeff Beech Efficient consumer response - David Sharpe and Richard Hill Components of demand planning - Todd Smith, Jay Mabe and Jeff Beech Effective demand management - Jamie Bolton Time compression in the supply chain - Jon Bumstead Towards finding the perfect match - Ananth Raman The personal computer supply chain - Terry Austin. Part II Strategic Response: Overview Channel Strategy: Strategic value networks - Randy Barba, Philip Roussel and Bruce Bendix Formulating a channel strategy - John Miller The global retail supply chain - Ken Bonning, Ed Rader and Rick Chavie The consumer direct channel - Steve Bartolotta Supply Chain Configuration: Relationships and alliances - Martin Christopher Strategic sourcing - Gregory Owens, Olivier Vidal, Rick Toole and Donovan Favre Network-modelling tools - Sue Jimenez, Tim Brown and Joe Jordan Global supply management - Dave Anderson, Yamini Dhillon and Julian Remnant Operations and Distribution Management: Lean synchronous manufacturing - David Kennedy, Barry Elliott and Frank Carbone Distribution operations - Duane Marvick and John White Transport management - Rich Bergmann and Craig Rawlings Inventory management - Chris Norek Warehouse-management systems technologies - Bruce Richmond and Eric Peters. Part III Cultural Capability: Overview Organization Options: Alternative organization options - Paula Giles and Anthony Hancy Fourth-party logistics - John Gattorna Change Management: The dynamics of change in the s

Apparatus and method for a bookmarking system

Abstract: A bookmarking system is provided that includes a user input device and a network server. A person who is viewing a program, e.g., watching a network news program on television, can bookmark an archived version of that program for future reference. The viewer utilizes the user input device to communicate to the network server the identity of the program of interest. The network server uses the identification information for the program of interest to identify a URL for the archived version of the program. The network server transmits the URL for the archived program to the personal computer of the viewer.