Over forty years ago, Vannevar Bush articulated his vision of a “Memex” machine: “associative indexing, … whereby any item may be caused at will to select immediately and automatically another” [Bush 45]. In the ...
ISBN:
(纸本)0201142376
Over forty years ago, Vannevar Bush articulated his vision of a “Memex” machine: “associative indexing, … whereby any item may be caused at will to select immediately and automatically another” [Bush 45]. In the sixties, Engelbart [Engelbart, English 68] built collaborative systems to provide idea structuring and sharing. Nelson [Nelson 81] coined “hypertext” and proposed world-wide networks for publishing, linking, annotating and indexing multiple versions of documents. With increasing numbers of research projects, papers, panels and conferences, and commercially available systems (e.g. Notecards by Xerox, Guide by Owl and HyperCard by Apple) in recent years, hypertext may be an idea whose time has finally come — or at least a phenomenon not to be *** goal of this panel is not to define hypertext or hypermedia (at its simplest: non-linearly arranged and accessed information), debate its uniqueness, explain implementation issues, or survey the many applications and contributions in the field (see [Conklin 87] for an excellent survey of Hypertext, and the Proceedings of Hypertext '87 Workshop at University of North Carolina, Chapel Hill). Rather, we intend to approach it from the perspective of the information user: reader, searcher, author. The panel will address the following issues:Are the processes of authoring and understanding helped or hindered by the non-linear structure of hypertext, for which kinds of tasks and users? What is the difference between a hypertext writer and a knowledge engineer? In searching for information, what is the difference between browsing and querying?What experiments need to be done? What tools, environment or interfaces can improve the process of information creation and access? Can the overhead of creating or interpreting structure be reduced?When will hypertext replace paper, or should it? How do functions of author and reader co-evolve? Could this revolutionize society like the printing press? Why didn't the panelists cre
作者：
GERSH, JRThe authoris a principal staff engineer at The Johns Hopkins University Applied Physics Laboratory
where he supervises the AAW Operations Section of the Combat Direction Group. Since joining JHU/APL in 1980 he has been involved in the specification development and testing of advanced surface combat direction systems specializing in the application of rule-based control mechanisms to command and control problems. In 1985-86 he chaired the Doctrine Working Group of the Naval Sea Systems Command's Combat Direction System Engineering Committee. Mr. Gersh served in the U.S. Navy from 1968 to 1977 as a sonar technician and as a junior officer (engineering and gunnery) aboard Atlantic Fleet frigates and as a member of the U.S. Naval Academy's Electrical Engineering faculty. He was educated at Harvard University and the Massachusetts Institute of Technology receiving S. B. S. M. and E. E. degrees in electrical engineering from the latter. He holds certificates as a commercial pilot and flight instructor and is a member of the U.S. Naval Institute the IEEE Computer Society and the American Association for Artificial Intelligence.
For the last four years the most advanced surface combat direction system (CDS) of the U.S. Navy has employed a limited knowledge-based control mechanism. Implemented in the Aegis Weapon System's command and decis...
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For the last four years the most advanced surface combat direction system (CDS) of the U.S. Navy has employed a limited knowledge-based control mechanism. Implemented in the Aegis Weapon System's command and decision element, this capability is called control by doctrine, and is a foundation for the Ticonderoga class cruisers' exceptional performance. Control by doctrine allows CIC personnel to direct that certain CDS functions be performed automatically upon tracks with specified characteristics. In effect, these CDS functions, from identification to engagement, can now be controlled through the specification and activation of general system response rules rather than by individual operator actions. The set of active rules, called doctrine statements, forms a system knowledge-base. The advanced Combat Direction System, Block 1, successor to today's Naval Tactical Data System, will also employ control by doctrine. As part of a larger effort investigating Aegis/ACDS commonality issues, a Doctrine Working Group was chartered to consider, among other things, implications for force-wide interoperability of multiple systems with such rule-based control mechanisms. The working group produced a set of design objectives for doctrine statement standardization across CDSs. Principal features of these objectives are described. The prospect of several such ships operating together in a battle group has raised questions as to the methods by which the actions of ships with those doctrinally-automated systems can best be coordinated. Related questions deal with specific design features for the support of such coordinated action. Work is now being carried out to investigate these questions. Combat system automation through doctrine statements is only one kind of rule-based control. Much work in the area of artificial intelligence deals with the use and maintenance of complex systems of rules, usually in non-real-time problem solving applications. Such systems are just now beginning
Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continu...
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Air cushion vehicles (ACVs) have operated successfully on commercial routes for about twenty years. The routes are normally quite short; the craft are equipped with radar and radio navigation aids and maintain continuous contact with their terminals. Navigation of these craft, therefore, does not present any unusual difficulty. The introduction of air cushion vehicles into military service, however, can present a very different picture, especially when external navigation aids are not available and the craft must navigate by dead reckoning. This paper considers the problems involved when navigating a high-speed air cushion vehicle by dead reckoning in conditions of poor visibility. A method is presented to assess the ACV's navigational capability under these circumstances. A figure of merit is used to determine the sensitivity of factors which affect navigation such as the range of visibility, point-to-point distance, speed, turning radius and accuracy of onboard equipment. The method provides simplistic but adequate answers and can be used effectively to compare the-capability and cost of alternative navigation concepts.
作者：
SLAGER, JJTOMASSONI, CASANDBERG, WCTHE AUTHORS: Mr. John S. Slager:is currently the Director of Hydrodynamic Design at Designers & Planners (D&P)
Inc. Arlington Va. He received his B.S. degree from Webb Institute of Naval Architecture in 1949 and from then until 1964 was employed as Naval Architect and Supervisory Naval Architect in the Preliminary Design Branch of the Navy's Bureau of Ships where he was involved in Feasibility Conceptual and Preliminary Design studies for all types of Navy Surface Ships and Submarines. From 1964 to 1980 he was employed as Principal Naval Architect at Hydronautics Inc. where he continued to be involved in early-stage design work primarily naval ships. In recent years he has concentrated on improvement of ship hydrodynamic performance and has been involved in the development and definition of the hull forms as well as the power performance predictions for many recent naval ship designs. In 1980 he joined D&P where his responsibilities include management of and participation in ship hydrodynamic studies and participation in the early-stage design of all types of ships. Mr. Slager is a member of RINA and SNA ME. Mr. Carlos A. Tomassoni:is Director of Ship Design and Marine Economics at D&P. He received his M.S. degree in Naval Architecture and Marine Engineering from the University of Buenos Aires in 1962 and began his career as a Naval Architect in the largest naval shipyard in his native country. In 1965
he joined the firm of John J. McMullen Associates in New York City as Project Engineer. He also worked as a Senior Naval Architect for the Advanced Marine Technology Division of Litton Industries during the design of the DD 963 Class ships and most recently for Hydronautics Inc. where he reached the position of Head Naval Architecture Division. In his current capacity at D&P he is responsible for early-stage ship design work and marine economic activities for both commercial and naval ships. He is particularly experienced in the development and use of ship design synthesis computer programs used
Speed-power margins are applied during the preparation of powering performance estimates for new U.S. Navy ship designs. This paper describes a study which was carried out in support of the U.S. Navy's Energy Cons...
Speed-power margins are applied during the preparation of powering performance estimates for new U.S. Navy ship designs. This paper describes a study which was carried out in support of the U.S. Navy's Energy Conservation Program. The primary purpose of the study was to estimate, for new naval ships, the savings in ship fuel consumption and ship acquisition costs which might be achieved by the use of design power margin values which are smaller than those in the current NAVSEA margin policy. A second, related purpose was to determine the risks, in terms of reduced probabilities of achieving design speed, which would be associated with the use of reduced power margin values. The results of the study indicate that reductions in fuel consumption and acquisition cost can be achieved if a projected new naval ship is redesigned with a smaller value of power margin. However, the results are shown to be dependent upon ship size constraints and on the type of propulsion system. The results of the study also indicate that, for a projected new naval ship, the use of a reduced design power margin value will be accompanied by a substantial decrease in the probability of achieving the design speed.
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