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Model-driven methodologies for pervasive information systems development

Fernandes, José Eduardo; Machado, Ricardo J.; Carvalho, João Álvaro
Fonte: TUCS - Turku Centre for Computer Science Publicador: TUCS - Turku Centre for Computer Science
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
85.63%
This paper intends to introduce the concept of pervasive information systems (PIS) and the issues that arise from the software development for pervasive information systems. The model driven approach is generally described and its benefits to the software design are identified. Finally, some future directions for the usage of model driven methodologies within the development of PIS are highlighted, presenting some specific problems that nowadays that kind of methodologies have not yet been able to overcome.

Supporting content-based image retrieval and computer-aided diagnosis systems with association rule-based techniques

RIBEIRO, Marcela X.; BUGATTI, Pedro H.; TRAINA JR., Caetano; MARQUES, Paulo M. A.; ROSA, Natalia A.; TRAINA, Agma J. M.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
85.73%
In this work, we take advantage of association rule mining to support two types of medical systems: the Content-based Image Retrieval (CBIR) systems and the Computer-Aided Diagnosis (CAD) systems. For content-based retrieval, association rules are employed to reduce the dimensionality of the feature vectors that represent the images and to improve the precision of the similarity queries. We refer to the association rule-based method to improve CBIR systems proposed here as Feature selection through Association Rules (FAR). To improve CAD systems, we propose the Image Diagnosis Enhancement through Association rules (IDEA) method. Association rules are employed to suggest a second opinion to the radiologist or a preliminary diagnosis of a new image. A second opinion automatically obtained can either accelerate the process of diagnosing or to strengthen a hypothesis, increasing the probability of a prescribed treatment be successful. Two new algorithms are proposed to support the IDEA method: to pre-process low-level features and to propose a preliminary diagnosis based on association rules. We performed several experiments to validate the proposed methods. The results indicate that association rules can be successfully applied to improve CBIR and CAD systems...

Integration of distributed and heterogeneous information for public-private policy analyses

Cheng, David Su-Kai, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 83 p.; 4476470 bytes; 4476276 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
75.75%
Databases and analysis tools currently being used to study carbon dioxide capture and storage (CCS) options are managed by diverse organizations and are heterogeneous in format. Tools to study the various components of a CCS system have been developed in several fields including chemistry, geology, and economics. Data being used to run analyses are being obtained from an equally diverse set of organizations, from data collected for environmental assessments to data on oil and gas exploration. These variations in tools and data cause complications in systems-level analyses, resulting in additional effort expended in data collection and opportunities for human error. A geographic information system has been implemented to automate and support robust studies of both component and system options. Context management and information integration techniques have been designed into the system. The system improves the availability and quality of information by automatically managing the distributed and heterogeneous data sources. The resulting information is being used to advance research and development of CCS systems through efforts such as the NETL sponsored Regional Carbon Sequestration Partnerships. This paper will present an overview of the system and initial results of its application to CCS-related data.; by David Su-Kai Cheng.; Thesis (S.M.)--Massachusetts Institute of Technology...

Information theoretic models of storage and memory

Hall, Susan Aileen
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 104 leaves; 5917755 bytes; 5917510 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
85.71%
by Susan Aileen Hall.; Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982.; MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING; Includes bibliographical references.

Enhancement of catalog processing system for MIT Science Fiction Society

Wheeler, Cheryl Ann
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 51 leaves; 2047023 bytes; 2046783 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
85.67%
by Cheryl Ann Wheeler.; Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982.; MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING; Includes bibliographical references.

Integrating coordination support into automated information systems

Cimral, John Jeffrey
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 113 leaves; 6857130 bytes; 6856892 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
85.59%
by John Jeffrey Cimral.; Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1983.; MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING; Bibliography: leaves 109-113.

A garbage-collecting associative memory for database systems

Ross, Richard Alan
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 66 leaves; 4656218 bytes; 4655974 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
85.67%
by Richard Alan Ross.; Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982.; MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.; Bibliography: leaves 64-66.

VISTA : a visualization tool for computer architects; Visualization tool for computer architects

Mihalik, Aaron D. (Aaron Daniel), 1980-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 55 leaves; 3599683 bytes; 3605553 bytes; application/pdf; application/pdf
EN_US
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75.73%
As computer architectures continue to grow in complexity, software developers and hardware engineers cope with the increasing complexity by developing proprietary applications, simulations and tool sets to understand the behavior of these complex systems. Although the field of information visualization is leading to powerful applications in many areas, information visualization applications for computer architecture development are either tightly coupled with a specific architecture or target a wide range of computer system data. This thesis introduces the Visualization Tool for Computer Architects (VISTA) Environment. The VISTA Environment is an extensible and modular information visualization environment for hardware engineers, software developers and educators to visualize data from a variety of computer architecture simulations at different levels of abstraction. The VISTA Environment leverages common attributes in simulation data, computer architecture visualizations, and computer architecture development methods to create a powerful information visualization environment to aid in designing, understanding and communicating complex computer architectures.; by Aaron D. Mihalik.; Thesis (M. Eng.)--Massachusetts Institute of Technology...

A framework for low-complexity iterative interference cancellation in communication systems

Chan, Albert M. (Albert Michael), 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 215 p.; 10260186 bytes; 10290533 bytes; application/pdf; application/pdf
EN_US
Relevância na Pesquisa
75.76%
Communication over interference channels poses challenges not present for the more traditional additive white Gaussian noise (AWGN) channels. In order to approach the information limits of an interference channel, interference mitigation techniques need to be integrated with channel coding and decoding techniques. This thesis develops such practical schemes when the transmitter has no knowledge of the channel. The interference channel model we use is described by r = Hx + w, where r is the received vector, H is an interference matrix, x is the transmitted vector of data symbols chosen from a finite set, and w is a noise vector. The objective at the receiver is to detect the most likely vector x that was transmitted based on knowledge of r, H, and the statistics of w. Communication contexts in which this general integer programming problem appears include the equalization of intersymbol interference (ISI) channels, the cancellation of multiple-access interference (MAI) in code-division multiple-access (CDMA) systems, and the decoding of multiple-input multiple-output (MIMO) systems in fading environments. We begin by introducing mode-interleaved precoding, a transmitter preceding technique that conditions an interference channel so that the pairwise error probability of any two transmit vectors becomes asymptotically equal to the pairwise error probability of the same vectors over an AWGN channel at the same signal-to-noise ratio (SNR). While mode-interleaved precoding dramatically increases the complexity of exact ML detection...

Efficient routing for peer-to-peer systems; Efficient routing for P2P systems

Gupta, Anjali, 1980-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 55 p.; 2687792 bytes; 2692427 bytes; application/pdf; application/pdf
EN_US
Relevância na Pesquisa
75.75%
This thesis examines the problem of locating and accessing an item stored in a large and volatile peer-to-peer system, and presents new ways of organizing items and peers to make this operation fast and efficient. Current structured peer-to-peer routing schemes keep routing information about only a small number of peers in the system, typically logarithmic in the size of the system. They do this under the assumption that it is infeasible to keep more routing information up-to-date since the system is highly volatile. As a result, when a node wants to locate an item, several peers have to be contacted in sequence before enough information is available to determine the location of the item. This makes routing a very long operation. In this thesis, we question this assumption and present two fast peer-to-peer routing algorithms. First, we present a "one hop" routing scheme. We show how to disseminate information about membership changes quickly enough so that peers maintain accurate routing tables with information about all peers in the system. Further, we demonstrate the feasibility of the system with analytical results and simulations. Second, we propose a "two hop" routing scheme for large scale systems of more than a few million peers...

Reduction of blocking artifacts using side information

Kamışlı, Fatih
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 96 p.; 10907252 bytes; 11143750 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
75.76%
Block-based image and video coding systems are used extensively in practice. In low bit-rate applications, however, they suffer from annoying discontinuities, called blocking artifacts. Prior research shows that incorporating systems that reduce blocking artifacts into codecs is useful because visual quality is improved. Existing methods reduce blocking artifacts by applying various post-processing techniques to the compressed image. Such methods require neither any modification to current encoders nor an increase in the bit-rate. This thesis examines a framework where blocking artifacts are reduced using side information transmitted from the encoder to the decoder. Using side information enables the use of the original image in deblocking, which improves performance. Furthermore, the computational burden at the decoder is reduced. The principal question that arises is whether the gains in performance of this choice can compensate for the increase in the bit-rate due to the transmission of side information. Experiments are carried out to answer this question with the following sample system: The encoder determines block boundaries that exhibit blocking artifacts as well as filters (from a predefined set of filters) that best deblock these block boundaries.; (cont.) Then it transmits side information that conveys the determined block boundaries together with their selected filters to the decoder. The decoder uses the received side information to perform deblocking. The proposed sample system is compared against an ordinary coding system and a post-processing type deblocking system with the bit-rate of these systems being equal to the overall bit-rate (regular encoding bits + side information bits) of the proposed system. The results of the comparisons indicate that...

Optimal information storage : nonsequential sources and neural channels

Varshney, Lav R. (Lav Raj)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 163 p.
ENG
Relevância na Pesquisa
75.78%
Information storage and retrieval systems are communication systems from the present to the future and fall naturally into the framework of information theory. The goal of information storage is to preserve as much signal fidelity under resource constraints as possible. The information storage theorem delineates average fidelity and average resource values that are achievable and those that are not. Moreover, observable properties of optimal information storage systems and the robustness of optimal systems to parameter mismatch may be determined. In this thesis, we study the physical properties of a neural information storage channel and also the fundamental bounds on the storage of sources that have nonsequential semantics. Experimental investigations have revealed that synapses in the mammalian brain possess unexpected properties. Adopting the optimization approach to biology, we cast the brain as an optimal information storage system and propose a theoretical framework that accounts for many of these physical properties. Based on previous experimental and theoretical work, we use volume as a limited resource and utilize the empirical relationship between volume anrid synaptic weight.; (cont.) Our scientific hypotheses are based on maximizing information storage capacity per unit cost. We use properties of the capacity-cost function...

Decentralized information flow control on a cluster

Cliffer, Natan Tsvi Cohen
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 54 p.
ENG
Relevância na Pesquisa
75.72%
Information flow control security models can prevent programs from divulging sensitive information in unexpected ways. There has been significant work on tracking information flow between processes in the same computer at the operating system level. I present a modification to the Flume information flow control system for OpenBSD that allows information flow to be tracked between programs on different computers, as long as the system software on all involved computers is maintained by the same trusted entity. This allows the benefits of Flume to be applied to computer systems that take the cluster approach to scaling.; by Natan Tsvi Cohen Cliffer.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.; Includes bibliographical references (p. 53-54).

Extending the hierarchical systems knowledge representation framework : interfacing with geographic information systems

Phillips, Reesa Brooke
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 108 p.
ENG
Relevância na Pesquisa
85.77%
This thesis presents the design and implementation of a geographic information systems framework in which engineering systems can be created and analyzed. This framework extends the hierarchical systems knowledge representation framework to allow geospatial information to be attributed to model objects and viewed within geographic information system tools. The addition of geospatial information allows analysts to use spatial analysis to better learn about engineering systems.; by Reesa Brooke Phillips.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.; Includes bibliographical references (p. 107-108).

Design principles and patterns for computer systems that are simultaneously secure and usable

Garfinkel, Simson
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 472 p.; 29543936 bytes; 31405031 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
75.74%
It is widely believed that security and usability are two antagonistic goals in system design. This thesis argues that there are many instances in which security and usability can be synergistically improved by revising the way that specific functionality is implemented in many of today's operating systems and applications. Specific design principles and patterns are presented that can accomplish this goal. Patterns are presented that minimize the release of confidential information through remnant and remanent data left on hard drives, in web browsers, and in documents. These patterns are based on a study involving the purchase of 236 hard drives on the secondary market, interviews conducted with organizations whose drives had been acquired, and through a detailed examination of modern web browsers and reports of information leakage in documents. Patterns are presented that enable secure messaging through the adoption of new key management techniques. These patterns are supported through an analysis of S/MIME handling in modern email clients, a survey of 469 Amazon.com merchants, and a user study of 43 individuals. Patterns are presented for promoting secure operation and for reducing the danger of covert monitoring. These patterns are supported by the literature review and an analysis of current systems.; (cont.) In every case considered...

A survey of SMS based Information Systems

Joshi, Manish R.; Pathak, Varsha M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/05/2015
Relevância na Pesquisa
75.73%
Short Message Service (SMS) based Information Systems (SMSbIS) provide an excellent alternative to a traditional approach of obtaining specific information by direct (through phone) or indirect (IVRS, Web, Email) probing. Information and communication technology and far reaching mobile penetration has opened this new research trend Number of key players in Search industry including Microsoft and Google are attracted by the expected increase in volume of use of such applications. The wide range of applications and their public acceptance has motivated researchers to work in this research domain. Several applications such as SMS based information access using database management services, SMS based information retrieval through internet (search engine), SMS based information extraction, question answering, image retrieval etc. have been emerged. With the aim to understand the functionality involved in these systems, an extensive review of a few of these SMSbISs has been planned and executed by us. These systems are classified into four categories based on the objectives and domains of the applications. As a result of this study a well structured functional model is presented here. The model is evaluated in different dimensions, which is presented in this paper. In addition to this a chronological progress with respect to research and development in this upcoming field is compiled in this paper. Such an extensive review presented in this paper would definitely help the researchers and developers to understand the technical aspects of this field. The functional framework presented here would be useful to the system designers to design and develop an SMS based Information System of any specific domain.; Comment: 17 pages 3 Figures 5 Tables

Norms and Commitment for iOrgs(TM) Information Systems: Direct Logic(TM) and Participatory Grounding Checking

Hewitt, Carl
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.78%
The fundamental assumption of the Event Calculus is overly simplistic when it comes to organizations in which time-varying properties have to be actively maintained and managed in order to continue to hold and termination by another action is not required for a property to no longer hold. I.e., if active measures are not taken then things will go haywire by default. Similarly extension and revision is required for Grounding Checking properties of systems based on a set of ground inferences. Previously Model Checking as been performed using the model of nondeterministic automata based on states determined by time-points. These nondeterministic automata are not suitable for iOrgs, which are highly structured and operate asynchronously with only loosely bounded nondeterminism. iOrgs Information Systems have been developed as a technology in which organizations have people that are tightly integrated with information technology that enables them to function organizationally. iOrgs formalize existing practices to provide a framework for addressing issues of authority, accountability, scalability, and robustness using methods that are analogous to human organizations. In general -iOrgs are a natural extension Web Services, which are the standard for distributed computing and software application interoperability in large-scale Organizational Computing. -iOrgs are structured by Organizational Commitment that is a special case of Physical Commitment that is defined to be information pledged. iOrgs norms are used to illustrate the following: -Even a very simple microtheory for normative reasoning can engender inconsistency In practice...

A theoretical foundation for building Knowledge-work Support Systems

Laha, Arijit
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/10/2009
Relevância na Pesquisa
75.78%
In this paper we propose a novel approach aimed at building a new class of information system platforms which we call the "Knowledge-work Support Systems" or KwSS. KwSS can play a significant role in enhancing the IS support for knowledge management processes, including those customarily identified as less amenable to IS support. In our approach we try to enhance basic functionalities provided by the computer-based information systems, namely, that of improving the efficiency of the knowledge workers in accessing, processing and creating useful information. The improvement, along with proper focus on cultural, social and other aspects of the knowledge management processes, can enhance the workers' efficiency significantly in performing high quality knowledge works. In order to build the proposed approach, we develop several new concepts. The approach analyzes the information availability and usage from the knowledge workers and their works' perspectives and consequently brings forth more transparency in various aspects of information life-cycle with respect to knowledge management. KsSSes are technology platforms, which can be implemented independently as well as in conjunction with other knowledge management and data management technology platforms...

Computer based Information Systems and Managers' Work

Kimble, Chris; McLoughlin, Kevin
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/02/2001
Relevância na Pesquisa
85.78%
This paper identifies three categories of model: the Technology Impact Model; the Social Impact Model and the Integrationist Model, which imply different views of the "impact" of Information Technology on work organisation. These models are used to structure data from case studies conducted by the authors to explore the implications of the use of computer-based information systems for managers' work. The paper argues that the "impact" of information systems is not a single stable and predictable outcome but a non-linear ongoing process that changes and evolves over time. It also argues that the actions of individuals and groups within an organisation are not wholly determined by outside forces: people can and do react to, and shape, systems in different ways. In this sense, the "impact" of computer-based information systems on managers' work reflects decisions made by managers themselves about how the technology is used.; Comment: Available from http://www-users.cs.york.ac.uk/~kimble/research/publics.html

Exploiting Conceptual Knowledge for Querying Information Systems

Selke, Joachim; Balke, Wolf-Tilo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/05/2011
Relevância na Pesquisa
75.74%
Whereas today's information systems are well-equipped for efficient query handling, their strict mathematical foundations hamper their use for everyday tasks. In daily life, people expect information to be offered in a personalized and focused way. But currently, personalization in digital systems still only takes explicit knowledge into account and does not yet process conceptual information often naturally implied by users. We discuss how to bridge the gap between users and today's systems, building on results from cognitive psychology.; Comment: International Conference on Philosophy's Relevance in Information Science (PRIS), Paderborn, Germany, 2008