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Instrumento de investigação clínico-epidemiológica em Cardiologia fundamentado no processamento de linguagem natural; A tool for clinical and epidemiological investigation in cardiology based on natural language processing

Castilla, André Coutinho
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/09/2007 PT
Relevância na Pesquisa
75.73%
O registro eletrônico do paciente (REP) está sendo gradativamente implantado no meio médico hospitalar. Grande parte das informações essenciais do REP está armazenada na forma de texto narrativo livre, dificultando operações de procura, análise e comparação de dados. O processamento de linguagem natural (PLN) refere-se a um conjunto de técnicas computacionais, cujo objetivo é a análise de texto através de conhecimentos léxicos, gramaticais e semânticos. O presente projeto propõe a criação de uma ferramenta computacional de investigação clínicoepidemiológica aplicada a textos narrativos médicos. Como metodologia propomos a utilização do processador de linguagem natural especializado em medicina MEDLEE desenvolvido para textos em Inglês. Para que seu uso seja possível textos médicos em Português são traduzidos ao Inglês automaticamente. A tradução automatizada (TA) é realizada utilizando o aplicativo baseado em regras SYSTRAN especialmente configurado para processar textos médicos através da incorporação de terminologias especializadas. O resultado desta seqüência de TA e PLN são informações conceituais que serão investigadas à procura de achados clínicos pré-definidos, atrvés de inferência lógica sobre uma ontologia. O objetivo experimental desta tese foi conduzir um estudo de recuperação de informações em um conjunto de 12.869 relatórios de radiografias torácicas à procura de vinte e dois achados clínicos e radiológicas. A sensibilidade e especificidade médias obtidas em comparação com referência formada pela opinião de três médicos radiologistas foram de 0...

Recuperação multimodal de imagens com realimentação de relevância baseada em programação genética; Multimodal image retrieval with relevance feedback based on genetic programming

Rodrigo Tripodi Calumby
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/03/2010 PT
Relevância na Pesquisa
65.82%
Este trabalho apresenta uma abordagem para recuperação multimodal de imagens com realimentação de relevância baseada em programação genética. Supõe-se que cada imagem da coleção possui informação textual associada (metadado, descrição textual, etc.), além de ter suas propriedades visuais (por exemplo, cor e textura) codificadas em vetores de características. A partir da informação obtida ao longo das iterações de realimentação de relevância, programação genética é utilizada para a criação de funções de combinação de medidas de similaridades eficazes. Com essas novas funções, valores de similaridades diversos são combinados em uma única medida, que mais adequadamente reflete as necessidades do usuário. As principais contribuições deste trabalho consistem na proposta e implementação de dois arcabouços. O primeiro, RFCore, é um arcabouço genérico para atividades de realimentação de relevância para manipulação de objetos digitais. O segundo, MMRFGP, é um arcabouço para recuperação de objetos digitais com realimentação de relevância baseada em programação genética, construído sobre o RFCore. O método proposto de recuperação multimodal de imagens foi validado sobre duas coleções de imagens...

Uso de técnicas de aprendizagem para classificação e recuperação de imagens; Use of learning techniques for image classification and retrieval

Fábio Augusto Faria
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/03/2010 PT
Relevância na Pesquisa
75.67%
Técnicas de aprendizagem vêm sendo empregadas em diversas áreas de aplicação (medicina, biologia, segurança, entre outras). Neste trabalho, buscou-se avaliar o uso da técnica de Programação Genética (PG) em tarefas de recuperação e classificação de imagens. PG busca soluções ótimas inspirada pela teoria de seleção natural das espécies. Indivíduos mais aptos (melhores soluções) tendem a evoluir e se reproduzir nas gerações futuras. As principais contribuições deste trabalho são: implementação de um classificador de imagens utilizando PG para combinar evidencias visuais (descritores de imagens) e assim, obter melhores resultados com relação à eficácia de classificação; Comparação de PG com outras técnicas de aprendizagem em tarefas de recuperação de imagens por conteúdo; Uso de regras de associação para recuperação de imagens; Learning techniques have been used in several applications (medicine, biology, surveillance systems, e.g.) This work aims to evaluate the use of the Genetic Programming (GP) learning technique for image retrieval and classification tasks. This technique is a problem-solving system that follows principles of inheritance and evolution, inspired by the idea of Natural Selection. The space of all possible solutions is investigated using a set of optimization techniques that imitate the theory of evolution. The main contributions of this work are: proposal of classifier implementation using GP to combine visual evidences (image descriptors) to be used in image classification tasks; comparison of GP with other learning techniques in content-based image retrieval tasks

The networking of interactive bibliographic retrieval systems

Fonte: Electronic Systems Laboratory, Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology Publicador: Electronic Systems Laboratory, Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology
Formato: vi, 164 p.; application/pdf
ENG
Relevância na Pesquisa
75.64%
by Richard S. Marcus, J. Francis Reintjes.; Bibliography: p. 123-127.; This report constitutes the final report for Grant NSF-SIS-74-18165 entitled "Research in the coupling of interactive information systems".

Investigations of computer-aided document search strategies

Fonte: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology Publicador: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology
Formato: 68 p.; 5156027 bytes; application/pdf
ENG
Relevância na Pesquisa
85.6%
by Richard S. Marcus.; "September 1, 1982."; Bbliography: p. 64-68.; National Science Foundation Division of Information Science and Technology Grant Number NSF IST-80-06516

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
85.66%
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.

Neural mechanisms involved in memory formation and retrieval within the rodent hippocampus : an in vivo electrophysiological study

Quirk, Michael C. (Michael Clayton), 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 188 leaves; 13086900 bytes; 13086658 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
75.64%
While it is well established that the rodent hippocampus plays a crucial role in the formation and retrieval of spatial memories, the neural mechanisms underlying this process have not been completely characterized. In this thesis I have combined large-scale recordings from multiple single cells within the hippocampus of behaving rodents with pharmacological and genetic manipulations of hippocampal function in order to investigate how the cellular and network properties of the hippocampus contribute to memory storage and retrieval. In Part I of this thesis, extracellular recordings are used to monitor systematic changes in the cellular properties of hippocampal pyramidal cells in vivo. These studies demonstrate that the biophysical characteristics of CA1 pyramidal cells undergo both short term (activity-dependent) and long-term (experience-dependent) modulations during behavior. Short tem changes in the biophysical state of hippocampal pyramidal cells interact with changes in synaptic input to determine the probability with which CA1 pyramidal cells generate single spikes or bursts of action potentials and may play an important role in influencing where and when mechanisms of plasticity are engaged during behavior (Chapters: 3-4). Longer term changes include: 1) input specific reductions in amplitude attenuation - consistent with an increase in dendritic excitability (Chapter 4)...

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
85.81%
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...

An apparatus to investigate a high density information storage technique / by P. Leigh-Jones

Leigh-Jones, Peter
Fonte: Adelaide, Publicador: Adelaide,
Tipo: Tese de Doutorado Formato: 148163 bytes; application/pdf
Publicado em //1971 EN
Relevância na Pesquisa
75.63%
Thesis (Ph.D.1972) from the Dept. of Electrical Engineering, University of Adelaide; 151 [47] leaves : ill. ; 26 cm.; Title page, contents and abstract only. The complete thesis in print form is available from the University Library.

Question-answering systems as efficient source of terminological information: evaluation

Olvera Lobo, Mar??a Dolores; Guti??rrez-Artacho, Juncal
Fonte: Health Libraries Group Publicador: Health Libraries Group
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.77%
Background:??? Question-answering systems (or QA Systems) stand as a new alternative for Information Retrieval Systems. Most users frequently need to retrieve specific information about a factual question to obtain a whole document. Objectives:??? The study evaluates the efficiency of QA systems as terminological sources for physicians, specialised translators and users in general. It assesses the performance of one open-domain QA system, START, and one restricted-domain QA system, MedQA. Method:??? The study collected two hundred definitional questions (What is????), either general or specialised, from the health website WebMD. Sources used by the open-domain QA system, START, and the restricted-domain QA system, MedQA, were studied to retrieve answers, and later a range of evaluation measures (precision, Mean Reciprocal Rank, Total Reciprocal Rank, First Hit Success) were applied to mark the quality of answers. Results:??? It was established that both systems are useful in the retrieval of valid definitional healthcare information, with an acceptable degree of coherent and precise responses from both. The answers supplied by MedQA were more reliable that those of START in the sense that they came from specialised clinical or academic sources...

Reengineering human performance and fatigue research through use of physiological monitoring devices, web-based and mobile device data collection methods, and integrated data storage techniques

Patillo, Paul L.; O'Connor, Maureen J.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xvi, 119 p. : ill. (chiefly col.)
Relevância na Pesquisa
75.73%
Approved for public release; distribution is unlimited; In the field of human research, particularly in operational environments, data collection techniques are difficult. Researchers often focus their efforts on the data analysis and overlook the shortcomings of their data collection and storage methodologies. In order to demonstrate effective data collection and storage methodology in a representative human research process, the process used by human fatigue and performance researchers at the Human Systems Integration Lab at Naval Postgraduate School (NPS) served as a Proof of Concept. Most recent studies conducted at NPS provided a model of the current process. The Knowledge Value Added (KVA) methodology was used as a tool of comparison of the current process to the reengineered process. Information technologies including wireless physiological monitoring devices, web-based and mobile device data collection methods, and integrated data storage techniques were incorporated in the reengineering effort. The data storage process included the design of a standard relational database format allowing research teams to easily access their data. This repository also enables data to be archived for future use (e.g., meta-analyses). To demonstrate the reengineered process in an operational environment...

Implementation of hospital-wide computer information system :a case study of this change process

Myers, Nancy E.
Fonte: Brock University Publicador: Brock University
Tipo: Electronic Thesis or Dissertation
ENG
Relevância na Pesquisa
75.57%
This case study examines the impact of a computer information system as it was being implemented in one Ontario hospital. The attitudes of a cross section of the hospital staff acted as a barometer to measure their perceptions of the implementation process. With The Mississauga Hospital in the early stages of an extensive computer implementation project, the opportunity existed to identify staff attitudes about the computer system, overall knowledge and compare the findings with the literature. The goal of the study was to develop a greater base about the affective domain in the relationship between people and the computer system. Eight exploratory questions shaped the focus of the investigation. Data were collected from three sources: a survey questionnaire, focused interviews, and internal hospital documents. Both quantitative and qualitative data were analyzed. Instrumentation in the study consisted of a survey distributed at two points in time to randomly selected hospital employees who represented all staff levels.Other sources of data included hospital documents, and twenty-five focused interviews with staff who replied to both surveys. Leavitt's socio-technical system, with its four subsystems: task...

On the storage and retrieval of primes and other random numbers using n-dimensional geometry

Eswaran, K.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.81%
We show that if you represent all primes with less than n-digits as points in n-dimensional space, then they can be stored and retrieved conveniently using n-dimensional geometry. Also once you have calculated all the prime numbers less than n digits, it is very easy to find out if a given number having less than n-digits is or is not a prime. We do this by separating all the primes which are represented by points in n-dimension space by planes. It so turns out that the number of planes q, required to separate all the points represented by primes less than n-digit, are very few in number. Thus we obtain a very efficient storage and retrieval system in n-dimensional space. In addition the storage and retieval repository has the property that when new primes are added there is no need to start all over, we can begin where we last left off and add the new primes in the repository and add new planes that separate them as and when necessary. Also we can arrange matters such that the repository can begin to accept larger primes which has more digits say n' where n' > n. The algorithm does not make use of any property of prime numbers or of integers in general,except for the fact that any n-digit integer can be represented as a point in n-dimension space. Therefore the method can serve to be a storage and retrieval repository of any set of given integers...

Dynamic Control of a Flow-Rack Automated Storage and Retrieval System

Hachemi, Khalid; Alla, Hassane.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/01/2009
Relevância na Pesquisa
75.77%
In this paper we propose a control scheme based on coloured Petri net (CPN) for a flow-rack automated storage and retrieval system. The AS/RS is modelled using Coloured Petri nets, the developed model has been used to capture and provide the rack state. We introduce in the control system an optimization module as a decision process which performs a real-time optimization working on a discrete events time scale. The objective is to find bin locations for the retrieval requests by minimizing the total number of retrieval cycles for a batch of requests and thereby increase the system throughput. By solving the optimization model, the proposed method gives according to customers request and the rack state, the best bin locations for retrieval, i.e. allowing at the same time to satisfy the customers request and carrying out the minimum of retrieval cycles.; Comment: CSCS 17 15th International Conference on Control Systems and Computer Science, Bucarest : Roumanie (2007)

An Effective Private Data storage and Retrieval System using Secret sharing scheme based on Secure Multi-party Computation

Nair, Divya G.; Binu, V. P.; Kumar, G. Santhosh
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/02/2015
Relevância na Pesquisa
75.91%
Privacy of the outsourced data is one of the major challenge.Insecurity of the network environment and untrustworthiness of the service providers are obstacles of making the database as a service.Collection and storage of personally identifiable information is a major privacy concern.On-line public databases and resources pose a significant risk to user privacy, since a malicious database owner may monitor user queries and infer useful information about the customer.The challenge in data privacy is to share data with third-party and at the same time securing the valuable information from unauthorized access and use by third party.A Private Information Retrieval(PIR) scheme allows a user to query database while hiding the identity of the data retrieved.The naive solution for confidentiality is to encrypt data before outsourcing.Query execution,key management and statistical inference are major challenges in this case.The proposed system suggests a mechanism for secure storage and retrieval of private data using the secret sharing technique.The idea is to develop a mechanism to store private information with a highly available storage provider which could be accessed from anywhere using queries while hiding the actual data values from the storage provider.The private information retrieval system is implemented using Secure Multi-party Computation(SMC) technique which is based on secret sharing. Multi-party Computation enable parties to compute some joint function over their private inputs.The query results are obtained by performing a secure computation on the shares owned by the different servers.; Comment: Data Science & Engineering (ICDSE)...

Information Storage and Retrieval for Probe Storage using Optical Diffraction Patterns

van Honschoten, Joost; de Jong, Henri; Koelmans, Wabe W.; Parnell, Thomas P.; Zaboronski, Oleg V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.88%
A novel method for fast information retrieval from a probe storage device is considered. It is shown that information can be stored and retrieved using the optical diffraction patterns obtained by the illumination of a large array of cantilevers by a monochromatic light source. In thermo-mechanical probe storage, the information is stored as a sequence of indentations on the polymer medium. To retrieve the information, the array of probes is actuated by applying a bending force to the cantilevers. Probes positioned over indentations experience deflection by the depth of the indentation, probes over the flat media remain un-deflected. Thus the array of actuated probes can be viewed as an irregular optical grating, which creates a data-dependent diffraction pattern when illuminated by laser light. We develop a low complexity modulation scheme, which allows the extraction of information stored in the pattern of indentations on the media from Fourier coefficients of the intensity of the diffraction pattern. We then derive a low-complexity maximum likelihood sequence detection algorithm for retrieving the user information from the Fourier coefficients. The derivation of both the modulation and the detection schemes is based on the Fraunhofer formula for data-dependent diffraction patterns. We show that for as long as the Fresnel number F<0.1...

Knowledge based text indexing and retrieval utilizing case based reasoning

Mick, Alan
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
85.79%
Information retrieval systems for documents normally rely on the use of keywords that describe the text in some fashion or another, or are contained in the text itself, for indexing and searching. These keywords may be associated with standard boolean operators, where presence or absence in the text or text description is used as the truth value, or other oper ators indicating their proximity to one another in the text. Another emerging approach is the use of content or knowledge based indexing and retrieval. In this approach the text is not represented or treated as a collection keywords, rather its meaning or semantic content is abstracted and the meaning is used to search for the text desired. This approach may have several advantages over the standard keyword approach. Both precision and recall of the search may be improved, increasing the likelihood that relevant texts will be found while decreasing the probability of finding irrelevant ones. The knowl edge based approach may also allow more sophisticated query techniques, for instance queries based on the purpose for which the text will be used. This thesis will explore the possibility and usefulness of applying case based reasoning to the problem of text search and retrieval. An easy-to-use expert system for information retrieval that utilizes case-based reasoning to improve...

System design for health information management in rural India

Khedkar, Rishikesh
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
75.61%
The problem of child mortality in India is one of the biggest that today's developing nation is dealing with. A complex matrix of different societal and behavioral forces is present at the root of this problem. Not only are absolute numbers of child deaths high in India, but the Child Mortality Rate (CMR) is also substantially higher among developing nations. Different sources of information at national as well as at state levels give feedback to the Indian Government on this nationwide issue. Looking closely at the west coast of India, the State of Maharashtra is having systematic problems in recording each child death. The way of operation of information sources and their accountability raises some serious issues about their efficiency, and the state governments are completely reliant on these sources to make decisions that save a child's life. This thesis study works in the domain of the health management information system in the context of the rural region of the State of Maharashtra, India. This study documents practical experience gained in relation with user centered product design while working with Auxiliary Nurse Midwife (ANM) workers. Research was carried out to see different problems that health workers face during field work and their ways of operations to collect data on child and maternal health. Existing infrastructure for communication in the rural region of Maharashtra and the efficiency of health workers to adapt a new system are primary concerns about design decisions made in response to this issue. The intention behind this study is to create a strong network of health information and communication transfer among sufferers and helpers. A sound information system can create a foundation for correct decision making and formulation of public policies to save one complete life not lived.

Retrieval from an image knowledge base

Janicki, James
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
75.89%
With advances in computer technology, images and image databases are becoming increasingly important. Retrievals of images in current image database systems have been designed using keyword searches. These carefully designed and handcrafted systems are very efficient given the application domain they are built for. Unfortunately, they are not adaptable to other domains, not expandable for other uses of the existing information and are not very forgiving to their users. The appearance of full-text search provides for a more general search given textual documents. However, pictorial images contain a vast amount of information that is difficult to catalog in a general way. Further this classification needs to be dynamic providing for flexible searching capability. The searching should allow for more than a pre-programmed set of search parameters, as exact searches make the image database quite useless for a search that was not designed into the original database. Further the incorporation of knowledge along with the images is difficult. Development of an image knowledge base along with content-based retrieval techniques is the focus of this thesis. Using an artificial intelligence technique called case-based reasoning, images can be retrieved with a degree of flexibility. Each image would be classified by user entered attributes about the image called descriptors. These descriptors would also have a "degree-of-importance" parameter. This parameter would indicate the relative importance or certainty of that descriptor. These descriptors are collected as the "case" for the image and stored in "frames" Each image can vary as to the amount of attribute information they contain. Retrieval of an image from the knowledge base begins with the entry of new descriptors for the desired image. Along with the descriptors are the degree-of-importance parameter. The degree-of-importance would indicate the requirement for the desired image to match that descriptor. Again...

An image storage system using a relational database management system to facilitate picture data handling

Johnson, Daryl G.
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
85.81%
The Image Storage System (ISS) is a general purpose graphics facility for the storage and retrieval of pictures. ISS utilizes the capabilities of the Mistress Relational Database Management System, the Relation Interpreter Package and the CORE Graphics Package. The system was developed to illustrate that by utilizing a database system for the storage of the actual picture description, users can incorporate graphics into their applications very simply without becoming a graphics or programming expert. Through the database, image data can be shared between applications and changes or additions to the image will not require program modification. As a consequence of using a data base management system, graphical as well as nongraphical information may be stored together. An important out come of this is that the graphical data may be accessible for non-graphical purposes as well. The database schema is illustrated and its flexibility and user adaptability is demonstrated. The graphics image interpreter is described as well as the underlying Relation Interpreter Package on which it is built.