Página 33 dos resultados de 2566 itens digitais encontrados em 0.044 segundos

Gestão da Mudança na Implementação de Sistemas de Informação em Organizações de Saúde

Santos, João Pedro Cordeiro
Fonte: Repositório Científico Lusófona Publicador: Repositório Científico Lusófona
Tipo: Dissertação de Mestrado
Português
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O sector da saúde a nível nacional e internacional atravessa uma fase de digitalização de processos. As organizações de saúde têm por isso sido confrontadas com a realização de projectos de sistemas de informação. Sendo a sua área de actuação sensível, é essencial diminuir o impacto da mudança provocada pela implementação de sistemas de informação para a saúde, maximizando a eficiência dos sistemas de informação e minimizando o impacto negativo na prestação de cuidados de saúde. Um dos principais problemas de um processo de mudança é o impacto nos profissionais, que exercem resistência, podendo inviabilizar o projecto de sistemas de informação. Neste âmbito, surge a gestão da mudança, que pretende suportar a mudança organizacional. Tendo em conta a importância dos sistemas de informação para a actividade das organizações de saúde, pretende-se estudar o comportamento dos profissionais e da organização durante o processo, ou seja, as características dos processos da gestão de mudança em projectos de sistemas de informação de saúde. A metodologia de investigação utilizada seguiu um método qualitativo interpretativo com base num estudo de caso. A instituição escolhida foi o Centro Hospitalar de S. Francisco...

Sistema de navegação para veiculos roboticos aereos baseado na observação e mapeamento do ambiente; Navigation system for aerial robotic vehicles based on the boservation and mapping of the environment at the School of Electrical and Computer Engineering

Cesar Dantas de Castro
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/04/2007 Português
Relevância na Pesquisa
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Este trabalho disserta sobre o desenvolvimento e a implementação de um sistema de localização e mapeamento simultâneos (SLAM) para um veículo robótico aéreo. Utilizando tal sistema, um robô que sobrevoe determinada área, até então desconhecida, deve ser capaz de conhecer sua postura no ambiente e mapeá-lo, sem o auxílio de mapas ou outras informações externas. Para alcançar este objetivo, o sistema recebe informações de uma unidade de medição inercial e de uma câmera, que observa características do ambiente e, indiretamente, a posição e a atitude do robô. Para fundir as informações dos dois conjuntos sensoriais embarcados, é utilizada uma arquitetura baseada no filtro de Kalman estendido, que atua como um estimador tanto da localização do dirigível quanto do mapa. Este sistema representa um primeiro passo em direção a uma solução de SLAM em seis graus de liberdade para o Projeto AURORA, que visa o desenvolvimento de tecnologia em robótica aérea. Desta forma, a abordagem proposta é validada em um ambiente de simulação composto de sensores virtuais e do simulador dinâmico do projeto AURORA. Os resultados apresentados mostram a eficácia da metodologia; This work addresses the development and implementation of a simultaneous localization and mapping (SLAM) system for aerial robotic vehicles. Through this system...

Deriving software architectures for CRUD applications : the FPL tower interface case study

Mashkoor, Atif; Fernandes, João M.
Fonte: IEEE Computer Society Press Publicador: IEEE Computer Society Press
Tipo: Artigo de Revista Científica
Publicado em /08/2007 Português
Relevância na Pesquisa
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The main aim of this paper is to present how to derive logical software architectures for CRUD (Create, Read, Update and Delete) applications using a specific technique called 4SRS. In this technique, a component diagram, which is obtained through transformations of use cases, is used to represent the logical software architecture. To show that the 4SRS technique, which was initially devised for behavior-intensive reactive systems, is also effective and gives seamless results for other software domains, it is being experimented on data processing systems, which typically follow a CRUD pattern. For demonstration purposes, the FPL tower interface system, which is responsible for communication between air traffic control operators and flight data processing system on airports of Portugal, has been used as a case study.

The design methodology for the verification of hybrid dynamical systems

Pluska, Michal; Sinclair, David
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: Conference item; all_ul_research; ul_published_reviewed; none
Português
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non-peer-reviewed; This work presents the OHMS methodology. The main aim of it is to design a model of a complex system easy to process by formal model checking procedure. The outcome is a verification report showing safety of the system. As the novel approach the complex mathematical notation is hidden form the user and use object base approach with graphical notation. It gives the user better experience and more flexibility in the design. On the other hand at the end of the process the user is still provided with the formal verification report helping in the correct design.

Automated Detection of Hematological Abnormalities through Classification of Flow Cytometric Data Patterns

Rossman, Mark A
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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Flow Cytometry analyzers have become trusted companions due to their ability to perform fast and accurate analyses of human blood. The aim of these analyses is to determine the possible existence of abnormalities in the blood that have been correlated with serious disease states, such as infectious mononucleosis, leukemia, and various cancers. Though these analyzers provide important feedback, it is always desired to improve the accuracy of the results. This is evidenced by the occurrences of misclassifications reported by some users of these devices. It is advantageous to provide a pattern interpretation framework that is able to provide better classification ability than is currently available. Toward this end, the purpose of this dissertation was to establish a feature extraction and pattern classification framework capable of providing improved accuracy for detecting specific hematological abnormalities in flow cytometric blood data. This involved extracting a unique and powerful set of shift-invariant statistical features from the multi-dimensional flow cytometry data and then using these features as inputs to a pattern classification engine composed of an artificial neural network (ANN). The contribution of this method consisted of developing a descriptor matrix that can be used to reliably assess if a donor’s blood pattern exhibits a clinically abnormal level of variant lymphocytes...

Computer-aided programming using formally specified design templates

Hemer, D.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Conference paper
Publicado em //2002 Português
Relevância na Pesquisa
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This paper describes a formal component language, used to support automated component-based program development. The components, referred to as templates, are machine processable, meaning that appropriate tool support, such as retrieval support, can be developed. The templates are highly adaptable, meaning that they can be applied to a wide range of problems. Some of the main features of the language are described, including: higher-order parameters; state variable declarations; specification statements and conditionals; applicability conditions and theories; meta-level placeholders; and abstract data structures.; David Hemer; ©2002 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Steady state distillation calculations: An investigation of computer techniques and an examination of results

Shearer, Luther T., Jr
Fonte: Universidade Rice Publicador: Universidade Rice
Português
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This work has been divided into two parts. The first is concerned with methods of computation suitable for use with digital computers for distillation problems with one feed and two product streams. Two methods were investigated (although others have been employed and reported by many authors): The Lewis-Matheson method and a modified Thiele-Geddes method. These techniques differ in that one requires floating-point arithmetic, while the other does not. A comparison has been made illustrating the merits and faults of both methods. The second section presents the results of a number of computations. A correlating method suggested recently by Geddes was investigated, as well as the more familiar ones of Gilliland and Brown & Martin. An empirical correlation was developed after the suggestion of Geddes for the range 0.5⩽LV⩽1.0, 0<DF⩽0.5 . Further, the effect of both the number of plates and the reflux ratio has been examined.

Shipboard sensor closed-loop calibration using wireless LANs and DataSocket transport protocols

Perchalski, Steven Joseph
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Approved for public release, distribution is unlimited; This thesis studies the feasibility of developing a closed-loop shipboard sensor calibration system with two main objectives. The first objective was to reduce the number of personnel required to calibrate a shipboard sensor by 50%. The second was to reduce the time required to complete the calibration process by 60%. This was achieved by displaying the sensor data and the calibration standard data on a tablet PC. Wireless technology was used to transmit the data from the sensor and the calibration standard to the tablet PC. The data from the sensor is sent via IEEE 802.11b wireless LAN using DataSocket protocol and the calibration standard is sent via Bluetooth protocol. The technology can be installed and used on current ships in the United States Navy. Four software programs were developed to accomplish these goals. One program runs on the tablet PC and the other three run on the network capable application processor (NCAP). These four programs accomplish the goals stated.

Digital phased array architectures for radar and communications based on off-the-shelf wireless technologies

Ong, Chin Siang
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Approved for public release, distribution is unlimited; This thesis is a continuation of the design and development of a three-dimensional 2.4 GHz digital phased array radar antenna. A commercial off-the-shelf quadrature modulator and demodulator were used as phase shifters in the digital transmit and receive arrays. The phase response characteristic of the demodulator was measured and the results show that the phase difference between the received phase and transmit phase is small. In order to increase the bandwidth of the phased array, a method of time-varying phase weights for linear frequency modulated signal was investigated. Using time-varying phase weights on transmit and receive give the best performance, but require the range information of the target. It is more practical to use time-varying phase weights on only one side (transmit or receive but not both), and constant phase weights on the other side. The simulation results showed that by using time-varying phase weights, the matched filter loss is not as severe as it is when using the conventional fixed weights technique. It was also found that this method is only effective for small scan angles when the time-bandwidth product is large. The approach to implement time-varying phase weights on transmit using commercial components such as direct digital synthesizer and quadrature modulator is discussed.

Reed-Muller codes in error correction in wireless adhoc networks

Tezeren, Serdar U.
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Approved for public release; distribution is unlimited; The IEEE 802.11a standard uses a coded orthogonal frequency division multi-plexing (COFDM) scheme in the 5-GHz band to support data rates up to 54 Mbps. The COFDM was chosen because of its robustness to multipath fading affects. In the stan-dard, convolutional codes are used for error correction. This thesis examines the perform-ance of the COFDM system with variable rate Reed-Muller (RM) error correction codes with a goal to reduce the peak-to-average power ratio (PAPR). Contrary to the expecta-tions, RM codes did not provide expected improvement in PAPR reduction. Peak clip-ping and Hanning windowing techniques were investigated in order to reduce the PAPR. The results indicate that a tradeoff exists between the PAPR and the bit-error rate (BER) performance. Although peak clipping yielded considerable reduction in PAPR, it required high signal-to-noise ratios. On the other hand, Hanning windowing provided only a small reduction in PAPR with reasonable BER performance.

Constant and power-of-2 segmentation algorithms for a high speed numerical function generator

Valenzuela, Zaldy M.
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
349.92035%
The realization of high-speed numeric computation is a sought-after commodity for real world applications, including high-speed scientific computation, digital signal processing, and embedded computers. An example of this is the generation of elementary functions, such as sin( ) x , x e and log( ) x . Sasao, Butler and Reidel [Ref. 1] developed a high speed numeric function generator using a look-up table (LUT) cascade. Their method used a piecewise linear segmentation algorithm to generate the functions [Ref. 1]. In this thesis, two alternative segmentation algorithms are proposed and compared to the results of Sasao, Butler and Reidel [Ref.1]. The first algorithm is the Constant Approximation. This algorithm uses lines of slope zero to approximate a curve. The second algorithm is the power-of-2-approximation. This method uses 2i x to approximate a curve. The constant approximation eliminates the need for a multiplier and adder, while the power-of-2-approximations eliminates the need for multiplier, thus improving the computation speed. Tradeoffs between the three methods are examined. Specifically, the implementation of the piecewise linear algorithm requires the most amount of hardware and is slower than the other two. The advantage that it has is that it yields the least amount of segments to generate a function. The constant approximation requires the most amount of hardware to realize a function...

Detection of frequency-hopped signals embedded in interference waveforms

Brown, Christopher K.
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Many military communications systems utilize frequency-hopped spread spectrum waveforms to protect against jamming and enemy detection. These waveforms may be subjected not only to intentional jamming but may also be unintentionally jammed by other communications signals. While some systems can overcome inband interference with more signal power, covert systems may be limited to small amounts of transmitted power. The objective of this thesis was to investigate a method for resolving a frequency-hopped signal embedded in interference waveforms. With exponential averaging in the frequency domain, the spectra of the interfering signals can be estimated as long as they are present over a period longer than that of the frequency-hopped signal. Certain FFT sizes and weights are more beneficial to achieving this estimate than others. The interference estimate can be used to extract the desired frequency-hopped signal through spectral division of the received signal with the estimate. This technique is designated as noise-normalization. Simulations in MATLAB demonstrate the use of the technique and show how the desired signal can be resolved.

Traffic profiling of wireless sensor networks

Kirykos, Georgios
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Network security is vital in wireless networks that are widely used today. We desire wireless networks that maintain a high degree of confidentiality, integrity, and availability. Wireless sensor networks pose unique challenges and limitations to the traditional schemes, which are used in the other wireless networks for security protection, and are due mainly to the increased vulnerability of physical attacks, energy and communication limitations. This thesis introduces the foundations of a network and anomaly-based Intrusion Detection System (IDS) tool, including both hardware and software components, that can be used for traffic profiling and monitoring of a wireless sensor network. The work demostrates how the IDS should capture and store traffic and use this information to create traffic profiles and baselines for normal traffic behavior. Then it describes how these baselines can be used to generate alerts based on traffic variations that imply possible attacks. Profiles on typical implementations of wireless sensor networks were observed and analyzed. Finally, initial indications from basic analysis of wireless sensor network traffic demonstrated a high degree of self-similarity.

Implementation of a fault tolerant control unit within an FPGA for space applications

Perez Casanova, Gaspar M.
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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The space environment implies a challenge for the development and utilization of electronics. Field Programmable Gate Arrays (FPGAs) represent a possible solution to that challenge. An FPGA itself is not a Fault Tolerant component, but with the correct configuration it can emulate and behave as one. The Configurable Fault Tolerant Processor (CFTP) developed at the Naval Postgraduate School (NPS) was intended to work as a platform for the implementation and testing of designs and experiments for space applications. The mayor components of the CFTP are two FPGAs, one configured as the control FPGA (X1) and the other as the experiment FPGA (X2). The configuration of the experiment FPGA already includes fault tolerant properties against radiation and its effects over FPGAs. The control experiment did not have any fault tolerance built-in. This thesis investigates the design, considerations, implementation, performance and resource utilization of a Fault Tolerant Control Unit based on FPGA technology using a Triple Modular Redundancy (TMR) approach.

Wirelessly networked digital phased array design and analysis of A 2.4 GHZ demonstrator

Burgstaller, Gert M.
Fonte: Monterey California. Naval Postgraduate School Publicador: Monterey California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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The wirelessly networked opportunistic digital array radar (WNODAR) system combines opportunistic phased array and aperstructure concepts. The array elements contain standâ alone transmitâ receive (T/R) modules with no hardwire connections other than prime power and are wirelessly networked to a central controller and processor unit. A fullâ scale WNODAR operating in the VHF/UHF frequency bands (300 MHz) exhibits many favorable properties, which make the system suitable for ballistic missile defense (BMD) early warning radar (EWR) applications. In order to validate the WNODAR concepts, demonstration arrays consisting of T/R modules realized using field programmable gate array (FPGA) technology are developed. The demonstration units are frequency scaled from the projected VHF/UHF frequency range to S-band (2.4 GHz) to make use of the abundance of commercial off the shelf (COTS) wireless communication components. This research primarily relates to the development of a demonstration T/R module and the evaluation and characterization of component devices. Design, analysis and simulation of an eightâ element demonstration array using MATLAB and CST Microwave Studio were conducted to examine expected array beam patterns.

Sensor synchronization, geolocation and wireless communication in a shipboard opportunistic array

Loke, Yong
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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A wirelessly networked opportunistic digital array radar (WNODAR) is an integrated ship wide digital phased array, where the array elements are placed at available open areas over the entire surface of the platform. The array elements are self-standing digital transmit/receive (T/R) modules with no hardwire connections other than prime power. All control and digitized signals are passed wirelessly between the elements and a central signal processor. This research investigates the problem of integrating the array elements through the design of a wireless synchronization and geolocation network. Phase synchronization of array elements is possible using a simple synchronization circuit. A technical survey of geolocation techniques was performed, and performance curves for the WNODAR operating under different seastate conditions were obtained. Analysis and simulation results suggest that a position location scheme to correct for dynamic effects of hull deflection is not absolutely necessary for an array operating at a VHF or lower UHF frequency. Finally, a design of the demonstration T/R module is proposed. Based on projected communication requirements, the full-scale WNODAR demands a 3.7 Gb/s data transmission rate. The multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) approach has been identified as a promising solution to achieve gigabit transmission rates.

Identification Of Outliers In Oxazolines AND Oxazoles High Dimension Molecular Descriptor Dataset Using Principal Component Outlier Detection Algorithm And Comparative Numerical Study Of Other Robust Estimators

Doreswamy; Vastrad, Chanabasayya . M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/12/2013 Português
Relevância na Pesquisa
354.0798%
From the past decade outlier detection has been in use. Detection of outliers is an emerging topic and is having robust applications in medical sciences and pharmaceutical sciences. Outlier detection is used to detect anomalous behaviour of data. Typical problems in Bioinformatics can be addressed by outlier detection. A computationally fast method for detecting outliers is shown, that is particularly effective in high dimensions. PrCmpOut algorithm make use of simple properties of principal components to detect outliers in the transformed space, leading to significant computational advantages for high dimensional data. This procedure requires considerably less computational time than existing methods for outlier detection. The properties of this estimator (Outlier error rate (FN), Non-Outlier error rate(FP) and computational costs) are analyzed and compared with those of other robust estimators described in the literature through simulation studies. Numerical evidence based Oxazolines and Oxazoles molecular descriptor dataset shows that the proposed method performs well in a variety of situations of practical interest. It is thus a valuable companion to the existing outlier detection methods.

Scalably Verifiable Cache Coherence

Zhang, Meng
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2013 Português
Relevância na Pesquisa
354.0798%

The correctness of a cache coherence protocol is crucial to the system since a subtle bug in the protocol may lead to disastrous consequences. However, the verification of a cache coherence protocol is never an easy task due to the complexity of the protocol. Moreover, as more and more cores are compressed into a single chip, there is an urge for the cache coherence protocol to have higher performance, lower power consumption, and less storage overhead. People perform various optimizations to meet these goals, which unfortunately, further exacerbate the verification problem. The current situation is that there are no efficient and universal methods for verifying a realistic cache coherence protocol for a many-core system.

We, as architects, believe that we can alleviate the verification problem by changing the traditional design paradigm. We suggest taking verifiability as a first-class design constraint, just as we do with other traditional metrics, such as performance, power consumption, and area overhead. To do this, we need to incorporate verification effort in the early design stage of a cache coherence protocol and make wise design decisions regarding the verifiability. Such a protocol will be amenable to verification and easier to be verified in a later stage. Specifically...

Reconstructing the Boundary of a Web Document

Sweet, James
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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Documents found on the World Wide Web (WWW) may be composed of a single web page, or several web pages that are linked together by a table of contents or some other commonly known document construct. When a document spans multiple web pages, it is often inconvenient to print or download the entire document using available tools. This thesis introduces a concept called the document boundary to facilitate representation and analysis of multi-page web documents, and suggests a two-phase approach towards automated identification of document boundaries. In the first phase, individual pages are examined to determine which links are most likely to represent an intra-document link. This procedure is applied recursively to identify a group of candidate pages which may be part of the same document. In the second phase, the link topology and other features of the identified pages are examined in aggregate for indications of a multi-page document. A test suite of both single- and multi-page web documents was assembled using a mixture of handpicked documents and documents which were gathered by an arbitrary third party. The document boundary detection system was applied to the main page of each document. The document boundary detection system was able to achieve a success rate of 73% when its results were compared to the ground truth documents.

An Adaptive estimation scheme for reducing communications in a distributed control implementation

Burry, Aaron
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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This paper examines the application of adaptive estimation and control techniques to reduce the amount of communication required between subsystems in a distributed control implementation. Rather than require a large amount of communications to broadcast the outputs or the states of each of the subsystem nodes to all of the other nodes at every sampling instant, local estimators in each subsystem are used to predict the state vectors for all of the other subsystems. These estimates are then used in the calculation of the controller outputs for each of the subsystems. Prior work in the literature has focused on static estimation schemes to achieve such reductions in communications. However, such schemes typically require very accurate models of the plant in order to maintain the desired reduction in communications. Poorly modeled dynamics or systems whose dynamics change slowly over time (due to aging of components, changes in plant parameters such as a robot picking up a heavy object, etc.) can cause a substantial increase in the amount of communications required to maintain the desired system performance. In order to avoid this, this paper presents an adaptive estimation and control scheme for each subsystem in the distributed implementation. The stability of the state estimators and the convergence of the state tracking errors to within a desired threshold is proven. The performance of the system using perfect communication at every sampling instant...