Página 16 dos resultados de 4609 itens digitais encontrados em 0.076 segundos

Developing and implementing an open and non-proprietary device description for FOUNDATION fieldbus based on software standards

PANTONI, Rodrigo Palucci; BRANDAO, Dennis
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
571.83855%
Support for interoperability and interchangeability of software components which are part of a fieldbus automation system relies on the definition of open architectures, most of them involving proprietary technologies. Concurrently, standard, open and non-proprietary technologies, such as XML, SOAP, Web Services and the like, have greatly evolved and been diffused in the computing area. This article presents a FOUNDATION fieldbus (TM) device description technology named Open-EDD, based on XML and other related technologies (XLST, DOM using Xerces implementation, OO, XMIL Schema), proposing an open and nonproprietary alternative to the EDD (Electronic Device Description). This initial proposal includes defining Open-EDDML as the programming language of the technology in the FOUNDATION fieldbus (TM) protocol, implementing a compiler and a parser, and finally, integrating and testing the new technology using field devices and a commercial fieldbus configurator. This study attests that this new technology is feasible and can be applied to other configurators or HMI applications used in fieldbus automation systems. (c) 2008 Elsevier B.V. All rights reserved.; Engineering School of SAO Carlos University of SAO Paulo (USP)

The Lynx Distributed Programming Language: Motivation, Design, and Experience

Scott, Michael L. (1959 - )
Fonte: University of Rochester. Computer Science Department. Publicador: University of Rochester. Computer Science Department.
Tipo: Relatório
Português
Relevância na Pesquisa
570.38934%
A programming language can provide much better support for interprocess communication than a library package can. Most message-passing languages limit this support to communication between the pieces of a single program, but this need not be the case. Lynx facilitates convenient, typesafe message passing not only within applications, but also between applications, and among distributed collections of servers. Specifically, it addresses issues of compiler statelessness, late binding, and protection that allow run-time interaction between processes that were developed independently and that do not trust each other. Implementation experience with Lynx has yielded important insights into the relationship between distributed operating systems and language run-time support packages, and into the inherent costs of high-level message-passing semantics.

A Language of Suggestions for Program Parallelization

Zhang, Chao ; Feng, Xiaobing ; Ding, Chen (1970 - ); Gu, Xiaoming (1980 - ); Bai, Tongxin (1977 - ); Kelsey, Kirk M.
Fonte: University of Rochester. Computer Science Department. Publicador: University of Rochester. Computer Science Department.
Tipo: Relatório
Português
Relevância na Pesquisa
570.64844%
Coarse-grained task parallelism exists in sequential code and can be leveraged to boost the use of chip multi-processors. However, large tasks may execute thousands of lines of code and are often too complex to analyze and manage statically. This report describes a programming system called emph{suggestible parallelization}. It consists of a programming interface and a support system. The interface is a small language with three primitives for marking possibly parallel tasks and their possible dependences. The support system is implemented in software and ensures correct parallel execution through speculative parallelization, speculative communication and speculative memory allocation. It manages parallelism dynamically to tolerate unevenness in task size, inter-task delay and hardware speed. When evaluated using four full-size benchmark applications, suggestible parallelization obtains up to a 6 times speedup over 10 processors for sequential legacy applications up to 35 thousand lines in size. The overhead of software speculation is not excessively high compared to unprotected parallel execution.

Analyzing anti-terrorist tactical effectiveness of picket boats for force protection of Navy ships using X3D graphics and agent-based simulation

Harney, James William
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xxii, 228 p. : ill. (chiefly col.) ;
Português
Relevância na Pesquisa
571.37086%
Approved for public release, distribution unlimited; S) technologies to demonstrate a prototypical planning tool that can be used by today's deployed warfighter. All research and work is conducted in a web-based, 'user-centric' fashion utilizing a combination of user-driven and agentbased control of entities for simulation iterations, along with various open source technologies which include Extensible 3D Graphics (X3D), Scalable Vector Graphics (SVG), and Extensible Markup Language (XML). Conventions are demonstrated for the integration of the many academic disciplines utilized during this research to achieve automatic generation of tactically significant scenarios. In order to give the end-user the greatest insight towards potential drawbacks in the tactical planning against surface-borne terrorist threats, various 2D and 3D media provide both real-time and non-real time scenario playback. The result of this work is a fully integrated, prototypical, Java-based application that demonstrates how various Open-Source, web-based technologies can be applied in order to provide the tactical operator with tools to aid in Force Protection planning. Scenarios can be auto generated, viewed, analyzed, and manipulated by end users with little to no computer experience necessary beyond requirements for operation of a desktop personal computer (PC) in the Information Technology for the 21st Century (IT-21) environment at sea. This approach has broad applicability to improve the tactical awareness and defensive posture of ships defending against terrorist attacks in port.; Lieutenant...

Abstraction in the INTEL iAPX-432 prototype systems implementation language

MacLennan, Bruce J.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Relatório Formato: 26 p. ; 28 cm.
Português
Relevância na Pesquisa
572.02035%
This report describes the abstraction mechanism of a prototype systems implementaiton language for Intel's iAPX-432 microprocessor. Full exploitation of the 432's facilities places many demands on a language intended for systems implementation. The 432 is a capability-based machine, with hardware-enforced typing of large objects, dynamically instantiated domains (i.e., packages), hardware-enforced information information hiding (seals), and hardware-supported, software-defined access-rights (trademarks). The prototype language's support for these facilities is described in this project; Prepared for: Chief of Naval Research, Arlington, Virginia 22217.; http://archive.org/details/abstractioninint00macl; 61152N: RROOO-0 1-100, N0001483WR30104; NA

Automatic Prediction of Rheumatoid Arthritis Disease Activity from the Electronic Medical Records

Lin, Chen; Karlson, Elizabeth W.; Canhao, Helena; Miller, Timothy A.; Dligach, Dmitriy; Chen, Pei Jun; Perez, Raul Natanael Guzman; Shen, Yuanyan; Weinblatt, Michael E.; Shadick, Nancy A.; Plenge, Robert M.; Savova, Guergana K.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
571.13535%
Objective: We aimed to mine the data in the Electronic Medical Record to automatically discover patients' Rheumatoid Arthritis disease activity at discrete rheumatology clinic visits. We cast the problem as a document classification task where the feature space includes concepts from the clinical narrative and lab values as stored in the Electronic Medical Record. Materials and Methods The Training Set consisted of 2792 clinical notes and associated lab values. Test Set 1 included 1749 clinical notes and associated lab values. Test Set 2 included 344 clinical notes for which there were no associated lab values. The Apache clinical Text Analysis and Knowledge Extraction System was used to analyze the text and transform it into informative features to be combined with relevant lab values. Results: Experiments over a range of machine learning algorithms and features were conducted. The best performing combination was linear kernel Support Vector Machines with Unified Medical Language System Concept Unique Identifier features with feature selection and lab values. The Area Under the Receiver Operating Characteristic Curve (AUC) is 0.831 (σ = 0.0317), statistically significant as compared to two baselines (AUC = 0.758, σ = 0.0291). Algorithms demonstrated superior performance on cases clinically defined as extreme categories of disease activity (Remission and High) compared to those defined as intermediate categories (Moderate and Low) and included laboratory data on inflammatory markers. Conclusion: Automatic Rheumatoid Arthritis disease activity discovery from Electronic Medical Record data is a learnable task approximating human performance. As a result...

Social Media and the Social Good: How Nonprofits Use Facebook to Communicate with the Public

Saxton, Gregory D.; Guo, Chao; Chiu, I-Hsuan; Feng, Bo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 23/03/2012 Português
Relevância na Pesquisa
572.03625%
In this study, we examine the social networking practices of the 100 largest nonprofit organizations in the United States. More specifically, we develop a comprehensive classification scheme to delineate these organizations' use of Facebook as a stakeholder engagement tool. We find that there are 5 primary categories of Facebook "statuses", which can be aggregated into three key dimensions - "information", "community", and "action". Our analysis reveals that, though the "informational" use of Facebook is still significant, nonprofit organizations are better at using Facebook to strategically engage their stakeholders via "dialogic" and "community-building" practices than they have been with traditional websites. The adoption of social media seems to have engendered new paradigms of public engagement.; Comment: Chinese-language article

Relative Observability of Discrete-Event Systems and its Supremal Sublanguages

Cai, Kai; Zhang, Renyuan; Wonham, W. Murray
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
570.38934%
We identify a new observability concept, called relative observability, in supervisory control of discrete-event systems under partial observation. A fixed, ambient language is given, relative to which observability is tested. Relative observability is stronger than observability, but enjoys the important property that it is preserved under set union; hence there exists the supremal relatively observable sublanguage of a given language. Relative observability is weaker than normality, and thus yields, when combined with controllability, a generally larger controlled behavior; in particular, no constraint is imposed that only observable controllable events may be disabled. We design algorithms which compute the supremal relatively observable (and controllable) sublanguage of a given language, which is generally larger than the normal counterparts. We demonstrate the new observability concept and algorithms with a Guideway and an AGV example.

Merlin: A Language for Provisioning Network Resources

Soulé, Robert; Basu, Shrutarshi; Marandi, Parisa Jalili; Pedone, Fernando; Kleinberg, Robert; Sirer, Emin Gün; Foster, Nate
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/07/2014 Português
Relevância na Pesquisa
570.38934%
This paper presents Merlin, a new framework for managing resources in software-defined networks. With Merlin, administrators express high-level policies using programs in a declarative language. The language includes logical predicates to identify sets of packets, regular expressions to encode forwarding paths, and arithmetic formulas to specify bandwidth constraints. The Merlin compiler uses a combination of advanced techniques to translate these policies into code that can be executed on network elements including a constraint solver that allocates bandwidth using parameterizable heuristics. To facilitate dynamic adaptation, Merlin provides mechanisms for delegating control of sub-policies and for verifying that modifications made to sub-policies do not violate global constraints. Experiments demonstrate the expressiveness and scalability of Merlin on real-world topologies and applications. Overall, Merlin simplifies network administration by providing high-level abstractions for specifying network policies and scalable infrastructure for enforcing them.

SIP APIs for Voice and Video Communications on the Web

Davids, Carol; Johnston, Alan; Singh, Kundan; Sinnreich, Henry; Wimmreuter, Wilhelm
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/06/2011 Português
Relevância na Pesquisa
569.43004%
Existing standard protocols for the web and Internet telephony fail to deliver real-time interactive communication from within a web browser. In particular, the client-server web protocol over reliable TCP is not always suitable for end-to-end low latency media path needed for interactive voice and video communication. To solve this, we compare the available platform options using the existing technologies such as modifying the web programming language and protocol, using an existing web browser plugin, and a separate host resident application that the web browser can talk to. We argue that using a separate application as an adaptor is a promising short term as well as long-term strategy for voice and video communications on the web. Our project aims at developing the open technology and sample implementations for web-based real-time voice and video communication applications. We describe the architecture of our project including (1) a RESTful web communication API over HTTP inspired by SIP message flows, (2) a web-friendly set of metadata for session description, and (3) an UDP-based end-to-end media path. All other telephony functions reside in the web application itself and/or in web feature servers. The adaptor approach allows us to easily add new voice and video codecs and NAT traversal technologies such as Host Identity Protocol. We want to make web-based communication accessible to millions of web developers...

Workflows for the Management of Change in Science, Technologies, Engineering and Mathematics

Autexier, Serge; David, Catalin; Dietrich, Dominik; Kohlhase, Michael; Zholudev, Vyacheslav
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/05/2011 Português
Relevância na Pesquisa
571.5117%
Mathematical knowledge is a central component in science, engineering, and technology (documentation). Most of it is represented informally, and -- in contrast to published research mathematics -- subject to continual change. Unfortunately, machine support for change management has either been very coarse grained and thus barely useful, or restricted to formal languages, where automation is possible. In this paper, we report on an effort to extend change management to collections of semi-formal documents which flexibly intermix mathematical formulas and natural language and to integrate it into a semantic publishing system for mathematical knowledge. We validate the long-standing assumption that the semantic annotations in these flexiformal documents that drive the machine-supported interaction with documents can support semantic impact analyses at the same time. But in contrast to the fully formal setting, where adaptations of impacted documents can be automated to some degree, the flexiformal setting requires much more user interaction and thus a much tighter integration into document management workflows.; Comment: 16 pages, Conference on Intelligent Computer Mathematics 2011, July, Bertinoro, Italy

Symbolic Computing with Incremental Mindmaps to Manage and Mine Data Streams - Some Applications

Brucks, Claudine; Hilker, Michael; Schommer, Christoph; Wagner, Cynthia; Weires, Ralph
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/02/2009 Português
Relevância na Pesquisa
572.233%
In our understanding, a mind-map is an adaptive engine that basically works incrementally on the fundament of existing transactional streams. Generally, mind-maps consist of symbolic cells that are connected with each other and that become either stronger or weaker depending on the transactional stream. Based on the underlying biologic principle, these symbolic cells and their connections as well may adaptively survive or die, forming different cell agglomerates of arbitrary size. In this work, we intend to prove mind-maps' eligibility following diverse application scenarios, for example being an underlying management system to represent normal and abnormal traffic behaviour in computer networks, supporting the detection of the user behaviour within search engines, or being a hidden communication layer for natural language interaction.; Comment: 4 pages; 4 figures

Report on a User Test and Extension of a Type Debugger for Novice Programmers

Ishii, Yuki; Asai, Kenichi
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 16/12/2014 Português
Relevância na Pesquisa
570.775%
A type debugger interactively detects the expressions that cause type errors. It asks users whether they intend the types of identifiers to be those that the compiler inferred. However, it seems that novice programmers often get in trouble when they think about how to fix type errors by reading the messages given by the type debugger. In this paper, we analyze the user tests of a type debugger and report problems of the current type debugger. We then extend the type debugger to address these problems. Specifically, we introduce expression-specific error messages and language levels. Finally, we show type errors that we think are difficult to explain to novice programmers. The subjects of the user tests were 40 novice students belonging to the department of information science at Ochanomizu University.; Comment: In Proceedings TFPIE 2014, arXiv:1412.4738

Low latency protocol for transmission of measurement data from FPGA to Linux computer via 10 Gbps Ethernet link

Zabolotny, Wojciech M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
569.72965%
This paper presents FADE-10G - an integrated solution for modern multichannel measurement systems. Its main aim is a low latency, reliable transmission of measurement data from FPGA-based front-end electronic boards (FEBs) to a computer-based node in the Data Acquisition System (DAQ), using a standard Ethernet 1 Gbps or 10 Gbps link. In addition to transmission of data, the system allows the user to send reliably simple control commands from DAQ to FEB and to receive responses. The aim of the work is to provide a possible simple base solution, which can be adapted by the end user to his or her particular needs. Therefore, the emphasis is put on the minimal consumption of FPGA resources in FEB and the minimal CPU load in the DAQ computer. The open source implementation of the FPGA IP core and the Linux kernel driver published under permissive license facilitates modifications and reuse of the solution. The system has been successfully tested in real hardware, both with 1 Gbps and 10 Gbps links.; Comment: Introduced further language corrections. Changed section describing resource consumption

Computer model of teaching with the varied coefficient of forgetting

Mayer, Robert V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/01/2014 Português
Relevância na Pesquisa
570.84047%
At computer modeling of process of training it is usually supposed that all elements of a training material are forgotten with an identical speed. But in practice that knowledge which are included in educational activity of the pupil are remembered much more strongly and forgotten more slowly then knowledge which he doesn't use. For the purpose of more exact research of didactic systems is offered the model of training, in which consider that in case increasing the number of applications of this element of a learning material: 1) duration of its use by the pupil decreases; 2) the coefficient of forgetting decreases. The computer model is considered, programs in the Pascal language are submitted, results of modeling are given and analyzed. Keywords: didactics, information and cybernetic approach, computer modeling of process of training.; Comment: 4 pages, 5 figures, 3 programs (on russian). http://injoit.org/index.php/j1

Using RDF to Model the Structure and Process of Systems

Rodriguez, Marko A.; Watkins, Jennifer H.; Bollen, Johan; Gershenson, Carlos
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
571.5958%
Many systems can be described in terms of networks of discrete elements and their various relationships to one another. A semantic network, or multi-relational network, is a directed labeled graph consisting of a heterogeneous set of entities connected by a heterogeneous set of relationships. Semantic networks serve as a promising general-purpose modeling substrate for complex systems. Various standardized formats and tools are now available to support practical, large-scale semantic network models. First, the Resource Description Framework (RDF) offers a standardized semantic network data model that can be further formalized by ontology modeling languages such as RDF Schema (RDFS) and the Web Ontology Language (OWL). Second, the recent introduction of highly performant triple-stores (i.e. semantic network databases) allows semantic network models on the order of $10^9$ edges to be efficiently stored and manipulated. RDF and its related technologies are currently used extensively in the domains of computer science, digital library science, and the biological sciences. This article will provide an introduction to RDF/RDFS/OWL and an examination of its suitability to model discrete element complex systems.; Comment: International Conference on Complex Systems...

Modeling two-language competition dynamics

Patriarca, M.; Castelló, X.; Uriarte, J. R.; Eguíluz, V. M.; Miguel, M. San
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/06/2012 Português
Relevância na Pesquisa
570.0505%
During the last decade, much attention has been paid to language competition in the complex systems community, that is, how the fractions of speakers of several competing languages evolve in time. In this paper we review recent advances in this direction and focus on three aspects. First we consider the shift from two-state models to three state models that include the possibility of bilingual individuals. The understanding of the role played by bilingualism is essential in sociolinguistics. In particular, the question addressed is whether bilingualism facilitates the coexistence of languages. Second, we will analyze the effect of social interaction networks and physical barriers. Finally, we will show how to analyze the issue of bilingualism from a game theoretical perspective.; Comment: 15 pages, 5 figures; published in the Special Issue of Advances in Complex Systems "Language Dynamics"

Global disease monitoring and forecasting with Wikipedia

Generous, Nicholas; Fairchild, Geoffrey; Deshpande, Alina; Del Valle, Sara Y.; Priedhorsky, Reid
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
569.43004%
Infectious disease is a leading threat to public health, economic stability, and other key social structures. Efforts to mitigate these impacts depend on accurate and timely monitoring to measure the risk and progress of disease. Traditional, biologically-focused monitoring techniques are accurate but costly and slow; in response, new techniques based on social internet data such as social media and search queries are emerging. These efforts are promising, but important challenges in the areas of scientific peer review, breadth of diseases and countries, and forecasting hamper their operational usefulness. We examine a freely available, open data source for this use: access logs from the online encyclopedia Wikipedia. Using linear models, language as a proxy for location, and a systematic yet simple article selection procedure, we tested 14 location-disease combinations and demonstrate that these data feasibly support an approach that overcomes these challenges. Specifically, our proof-of-concept yields models with $r^2$ up to 0.92, forecasting value up to the 28 days tested, and several pairs of models similar enough to suggest that transferring models from one location to another without re-training is feasible. Based on these preliminary results...

BASEL (Buffering Architecture SpEcification Language)

Kogan, Kirill; Menikkumbura, Danushka; Petri, Gustavo; Noh, Youngtae; Nikolenko, Sergey; Eugster, Patrick
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/10/2015 Português
Relevância na Pesquisa
570.38934%
Buffering architectures and policies for their efficient management constitute one of the core ingredients of a network architecture. In this work we introduce a new specification language, BASEL, that allows to express virtual buffering architectures and management policies representing a variety of economic models. BASEL does not require the user to implement policies in a high-level language; rather, the entire buffering architecture and its policy are reduced to several comparators and simple functions. We show examples of buffering architectures in BASEL and demonstrate empirically the impact of various settings on performance.; Comment: 11 pages, 11 figures, 2 tables

A Federated CloudNet Architecture: The PIP and the VNP Role

Abarca, Ernesto; Grassler, Johannes; Schaffrath, Gregor; Schmid, Stefan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/03/2013 Português
Relevância na Pesquisa
569.36125%
We present a generic and flexible architecture to realize CloudNets: virtual networks connecting cloud resources with resource guarantees. Our architecture is federated and supports different (and maybe even competing) economical roles, by providing explicit negotiation and provisioning interfaces. Contract-based interactions and a resource description language that allows for aggregation and abstraction, preserve the different roles' autonomy without sacrificing flexibility. Moreover, since our CloudNet architecture is plugin based, essentially all cloud operating systems (e.g., OpenStack) or link technologies (e.g., VLANs, OpenFlow, VPLS) can be used within the framework. This paper describes two roles in more detail: The Physical Infrastructure Providers (PIP) which own the substrate network and resources, and the Virtual Network Providers (VNP) which can act as resource and CloudNet brokers and resellers. Both roles are fully implemented in our wide-area prototype that spans remote sites and resources.