Qualitative mechanism models and the rationalization of procedures

A qualitative, cluster-based approach to the representation of hydraulic systems is described and its potential for generating and explaining procedures is demonstrated. Many ideas are formalized and implemented as part of an interactive, computer-based system. The system allows for designing, displaying, and reasoning about hydraulic systems. The interactive system has an interface consisting of three windows: a design/control window, a cluster window, and a diagnosis/plan window. A qualitative mechanism model for the ORS (Orbital Refueling System) is presented to coordinate with ongoing research on this system being conducted at NASA Ames Research Center

Textualities in the Digital Age

The article provides an overview of the symposium of the same name held at the University of Oregon on April 14, 2012. A summary of the presentations is included

Minimum-cost line broadcast in paths

AbstractUnder the line communication protocol, calls can be placed between pairs of non-adjacent sites over a path of lines connecting them; only one call can utilize a line at any time. This paper addresses questions regarding the cumulative cost, i.e., sum of lengths of calls, of broadcasting under the line protocol in path networks. Let Pn be the path with n vertices, and Cn be the cost of an optimal, line broadcast scheme from a terminal vertex in path Pn. We show that a minimum-cost line broadcast scheme from any source vertex in Pn has cost no more than Cn and no less than Cn − n + 2 for any n ⩾ 2 and any time t > [log2n]. We derive a closed-form expression for the minimum cost of a minimum-time line broadcast from a terminal vertex in certain paths and relate this to costs from nearby sources

Education, Technology, and Humans: An Interview with Jeffrey Schnapp

The interview reconstructs Jeffrey Schnapp's brilliant career from his origins as a scholar of Dante and the Middle Ages to his current multiple interdisciplinary interests. Among other things, Schnapp deals with knowledge design, media history and theory, history of the book, the future of archives, museums, and libraries. The main themes of the interview concern the relationships between technology and pedagogy, the future of reading, and artificial intelligence

Collective Intelligence, the Future of Internet and the IEML

Collective Intelligence, the book in French, that Pierre Levy wrote before the existence of the worldwide web, when only the Internet existed, it's a philosophical vision of the future, a philosophical vision of what could be a global civilization based on the digital and the general interconnection of all the computers. In the interview, Levy addresses the creation o the WWW by Tim Berners Lee as a form of collective intelligence. He then discusses Berners Lee's proposal for a reform of the WWW to avoid its confiscation by the big platforms, such as Google, Facebook, and Amazon. Then, he introduces his most recent project the IELM as a tool for semantic metadata and a code between the natural languages and the algorithms, and all the apparatus of computations

Minimum-time multidrop broadcast

AbstractThe multidrop communication model assumes that a message originated by a sender is sent along a path in a network and is communicated to each site along that path. In the presence of several concurrent senders, we require that the transmission paths be vertex-disjoint. The time analysis of such communication includes both start-up time and drop-off time terms. We determine the minimum time required to broadcast a message under this communication model in several classes of graphs

The Design of Template Immune Networks: Path Immunity

13 pagesA network is specified by a topology definition and a protocol definition. A network's topology, represented as a graph, defines its interconnection structure, while the protocol defines its operational behavior. A template is a connected graph. A topology G is immune to a set of templates T if G remains connected under removal of any imbedding of a single element of T. A network is template immune to a set of templates T if its topology is immune to T and its protocol guarantees that all operative sites can communicate in the presence of possible failures. A network is isolated template immune to a set of templates T if it is immune to multiple imbeddings of elements of T, where each imbedded template does not involve vertices that are neighbors of another imbedded template. We discuss networks that are isolated template immune to simple path templates of length k

Broadcasting in Trees with Multiple Originators

13 pagesBroadcasting is the information dissemination process in a communication network whereby all sites of the network become informed of a given message by calls made over lines of the network. We present an algorithm which, given a tree network and a time, determines a smallest set of subtrees covering sites of the network such that broadcast can be completed within the given time in each subtree. Information developed by the algorithm is sufficient to determine a satisfactory originator and calling scheme within each subtree