814 resultados para Computer- aided Engineering


Relevância:

80.00% 80.00%

Publicador:

Resumo:

This paper presents the project of a mobile cockpit system (MCS) for smartphones, which provides assistance to electric bicycle (EB) cyclists in smart cities' environment. The presented system introduces a mobile application (MCS App) with the goal to provide useful personalized information to the cyclist related to the EB's use, including EB range prediction considering the intended path, management of the cycling effort performed by the cyclist, handling of the battery charging process, and the provisioning of information regarding available public transport. This work also introduces the EB cyclist profile concept, which is based on historical data analysis previously stored in a database and collected from mobile devices' sensors. From the tests performed, the results show the importance of route guidance, taking into account the energy savings. The results also show significant changes on range prediction based on user and route taken. It is important to say that the proposed system can be used for all bicycles in general.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

More than ever, there is an increase of the number of decision support methods and computer aided diagnostic systems applied to various areas of medicine. In breast cancer research, many works have been done in order to reduce false-positives when used as a double reading method. In this study, we aimed to present a set of data mining techniques that were applied to approach a decision support system in the area of breast cancer diagnosis. This method is geared to assist clinical practice in identifying mammographic findings such as microcalcifications, masses and even normal tissues, in order to avoid misdiagnosis. In this work a reliable database was used, with 410 images from about 115 patients, containing previous reviews performed by radiologists as microcalcifications, masses and also normal tissue findings. Throughout this work, two feature extraction techniques were used: the gray level co-occurrence matrix and the gray level run length matrix. For classification purposes, we considered various scenarios according to different distinct patterns of injuries and several classifiers in order to distinguish the best performance in each case described. The many classifiers used were Naïve Bayes, Support Vector Machines, k-nearest Neighbors and Decision Trees (J48 and Random Forests). The results in distinguishing mammographic findings revealed great percentages of PPV and very good accuracy values. Furthermore, it also presented other related results of classification of breast density and BI-RADS® scale. The best predictive method found for all tested groups was the Random Forest classifier, and the best performance has been achieved through the distinction of microcalcifications. The conclusions based on the several tested scenarios represent a new perspective in breast cancer diagnosis using data mining techniques.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Dissertation presented at Faculty of Sciences and Technology of the New University of Lisbon to attain the Master degree in Electrical and Computer Science Engineering

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The goal of this project, one of the proposals of the EPS@ISEP 2014 Spring, was to develop an Aquaponics System. Over recent years Aquaponics systems have received increased attention due to its possibilities in helping reduce strain on resources within 1st and 3rd world countries. Aquaponics is the combination of Hydroponics and Aquaculture and mimics a natural environment in order to successfully apply and enhance the understanding of natural cycles within an indoor process. By using this knowledge of natural cycles it was possible to create a system with the capabilities similar to that of a natural environment with the benefits of electronic adaptions to enhance the overall efficiency of the system. The multinational team involved in its development was composed of five students, from five countries and fields of study. This paper covers their solution, involving overall design, the technology involved and the benefits it could bring to the current market. The team was able to achieve the final rendered Computer Aided Design (CAD) drawings, successfully performed all the electronic testing, and designed a solution under budget. Furthermore, the solution presented was deeply studied from the sustainability viewpoint and the team also developed a product specific marketing plan. Finally, the students involved in this project obtained new knowledge and skills.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The goal of this project, one of the proposals of the EPS@ISEP Spring 2014, was to develop an Aquaponics System. Over recent years Aquaponics systems have received increased attention since they contribute to reduce the strain on resources within 1st and 3rd world countries. Aquaponics is the combination of Hydroponics and Aquaculture, mimicking a natural environment in order to successfully apply and enhance the understanding of natural cycles within an indoor process. Using this knowledge of natural cycles, it was possible to create a system with capabilities similar to that of a natural environment with the support of electronics, enhancing the overall efficiency of the system. The multinational team involved in the development of this system was composed of five students from five countries and fields of study. This paper describes their solution, including the overall design, the technology involved and the benefits it can bring to the current market. The team was able to design and render the Computer Aided Design (CAD) drawings of the prototype, assemble all components, successfully test the electronics and comply with the budget. Furthermore, the designed solution was supported by a product sustainability study and included a specific marketing plan. Last but not least, the students enrolled in this project obtained new multidisciplinary knowledge and increased their team work and cross-cultural communication skills.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

BACKGROUND: Wireless capsule endoscopy has been introduced as an innovative, non-invasive diagnostic technique for evaluation of the gastrointestinal tract, reaching places where conventional endoscopy is unable to. However, the output of this technique is an 8 hours video, whose analysis by the expert physician is very time consuming. Thus, a computer assisted diagnosis tool to help the physicians to evaluate CE exams faster and more accurately is an important technical challenge and an excellent economical opportunity. METHOD: The set of features proposed in this paper to code textural information is based on statistical modeling of second order textural measures extracted from co-occurrence matrices. To cope with both joint and marginal non-Gaussianity of second order textural measures, higher order moments are used. These statistical moments are taken from the two-dimensional color-scale feature space, where two different scales are considered. Second and higher order moments of textural measures are computed from the co-occurrence matrices computed from images synthesized by the inverse wavelet transform of the wavelet transform containing only the selected scales for the three color channels. The dimensionality of the data is reduced by using Principal Component Analysis. RESULTS: The proposed textural features are then used as the input of a classifier based on artificial neural networks. Classification performances of 93.1% specificity and 93.9% sensitivity are achieved on real data. These promising results open the path towards a deeper study regarding the applicability of this algorithm in computer aided diagnosis systems to assist physicians in their clinical practice.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

O desenvolvimento da tecnologia informática e de melhor hardware, proporcionou ao mercado de aplicações informáticas, um grande crescimento nas últimas décadas. Paralelamente, o aprofundamento e investigação das disciplinas de engenharia industrial, de novas filosofias e tipologias de produção, proporcionam ao mercado de sistemas de informação, uma panóplia de soluções abrangentes a todos os sectores e departamentos das organizações. Apesar da grande oferta, nem sempre existe viabilidade financeira das organizações para adquirirem e/ ou implementarem uma solução eficaz que responda às suas necessidades específicas. A presente dissertação, incide na melhoria do sistema de orçamentação do produto numa indústria de produtos únicos, através de uma plataforma de informação que permita reduzir o tempo de elaboração, melhorando a estimação do tempo de produção. As exigências do mercado em causa, influenciadas pela concorrência de países com mão-de-obra mais barata, prazos de resposta a orçamentos muito curtos e pequenas margens de negociação e lucro, implicam a necessidade de que sejam minimizadas ao máximo as atividades sem valor acrescentado, como o caso da orçamentação. Foi elaborada uma análise à empresa, ao produto - cablagem, às operações e seus recursos em estudo de caso. Após o levantamento das operações de produção executadas na empresa, reuniram-se os tempos referentes aos tempos de elaboração de cada operação, tendo sido estes utilizados para melhorar a estimativa do tempo de produção. A plataforma de informação foi desenvolvida seguindo o processo produtivo de cablagens, princípios de orçamentação e algumas funcionalidades referentes a ferramentas de apoio à produção, tais como, Product Data Management, Computer Aided Design, Bill-of-Material e Visual Aid’s. Estruturada consoante as necessidades da empresa e respeitando a vasta gama de Matérias- Primas intervenientes na produção, a ferramenta desenvolvida proporcionou a redução do tempo de orçamentação e melhoria na estimativa dos tempos de produção. Esta ferramenta é no entanto transversal e com pequenas alterações, poderá ser implementada em qualquer outra indústria de produtos únicos.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This present study aimed to investigate the fatigue life of unused (new) endodontic instruments made of NiTi with control memory by Coltene™ and subjected to the multi curvature of a mandibular first molar root canal. Additionally, the instrument‟s structural behaviour was analysed through non-linear finite element analysis (FEA). The fatigue life of twelve Hyflex™ CM files was assessed while were forced to adopt a stance with multiple radius of curvature, similar to the ones usually found in a mandibular first molar root canal; nine of them were subjected to Pecking motion, a relative movement of axial type. To achieve this, it was designed an experimental setup with the aim of timing the instruments until fracture while worked inside a stainless steel mandibular first molar model with relative axial motion to simulate the pecking motion. Additionally, the model‟s root canal multi-curvature was confirmed by radiography. The non-linear finite element analysis was conducted using the computer aided design software package SolidWorks™ Simulation, in order to define the imposed displacement required by the FEA, it was necessary to model an endodontic instrument with simplified geometry using SolidWorks™ and subsequently analyse the geometry of the root canal CAD model. The experimental results shown that the instruments subjected to pecking motion displayed higher fatigue life values and higher lengths of fractured tips than those with only rotational relative movement. The finite element non-linear analyses shown, for identical conditions, maximum values for the first principal stress lower than the yield strength of the material and those were located in similar positions to the instrument‟s fracture location determined by the experimental testing results.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Relatório de estágio de mestrado em Arqueologia

Relevância:

80.00% 80.00%

Publicador:

Resumo:

El crecimiento exponencial del tráfico de datos es uno de los mayores desafíos que enfrentan actualmente los sistemas de comunicaciones, debiendo los mismos ser capaces de soportar velocidades de procesamiento de datos cada vez mas altas. En particular, el consumo de potencia se ha transformado en uno de los parámetros de diseño más críticos, generando la necesidad de investigar el uso de nuevas arquitecturas y algoritmos para el procesamiento digital de la información. Por otro lado, el análisis y evaluación de nuevas técnicas de procesamiento presenta dificultades dadas las altas velocidades a las que deben operar, resultando frecuentemente ineficiente el uso de la simulación basada en software como método. En este contexto, el uso de electrónica programable ofrece una oportunidad a bajo costo donde no solo se evaluan nuevas técnicas de diseño de alta velocidad sino también se valida su implementación en desarrollos tecnológicos. El presente proyecto tiene como objetivo principal el estudio y desarrollo de nuevas arquitecturas y algoritmos en electrónica programable para el procesamiento de datos a alta velocidad. El método a utilizar será la programación en dispositivos FPGA (Field-Programmable Gate Array) que ofrecen una buena relación costo-beneficio y gran flexibilidad para integrarse con otros dispositivos de comunicaciones. Para la etapas de diseño, simulación y programación se utilizaran herramientas CAD (Computer-Aided Design) orientadas a sistemas electrónicos digitales. El proyecto beneficiara a estudiantes de grado y postgrado de carreras afines a la informática y las telecomunicaciones, contribuyendo al desarrollo de proyectos finales y tesis doctorales. Los resultados del proyecto serán publicados en conferencias y/o revistas nacionales e internacionales y divulgados a través de charlas de difusión y/o encuentros. El proyecto se enmarca dentro de un área de gran importancia para la Provincia de Córdoba, como lo es la informática y las telecomunicaciones, y promete generar conocimiento de gran valor agregado que pueda ser transferido a empresas tecnológicas de la Provincia de Córdoba a través de consultorias o desarrollos de productos.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fuel cell, PEM fuel cell, Network theory, Computer aided modelling, Nonlinear analysis

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Purpose: Revolutionary endovascular treatments are on the verge of being available for management of ascending aortic diseases. Morphometric measurements of the ascending aorta have already been done with ECG-gated MDCT to help such therapeutic development. However the reliability of these measurements remains unknown. The objective of this work was to compare the intraobserver and interobserver variability of CAD (computer aided diagnosis) versus manual measurements in the ascending aorta. Methods and materials: Twenty-six consecutive patients referred for ECG-gated CT thoracic angiography (64-row CT scanner) were evaluated. Measurements of the maximum and minimum ascending aorta diameters at mid-distance between the brachiocephalic artery and the aortic valve were obtained automatically with a commercially available CAD and manually by two observers separately. Both observers repeated the measurements during a different session at least one month after the first measurements. Intraclass coefficients as well the Bland and Altman method were used for comparison between measurements. Two-paired t-test was used to determine the significance of intraobserver and interobserver differences (alpha = 0.05). Results: There is a significant difference between CAD and manual measurements in the maximum diameter (p = 0.004) for the first observer, whereas the difference was significant for minimum diameter between the second observer and the CAD (p <0.001). Interobserver variability showed a weak agreement when measurements were done manually. Intraobserver variability was lower with the CAD compared to the manual measurements (limits of variability: from -0.7 to 0.9 mm for the former and from -1.2 to 1.3 mm for the latter). Conclusion: In order to improve reproductibility of measurements whenever needed, pre- and post-therapeutic management of the ascending aorta may benefit from follow-up done by a unique observer with the help of CAD.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Purpose: Recently morphometric measurements of the ascending aorta have been done with ECG-gated MDCT to help the development of future endovascular therapies (TCT) [1]. However, the variability of these measurements remains unknown. It will be interesting to know the impact of CAD (computer aided diagnosis) with automated segmentation of the vessel and automatic measurements of diameter on the management of ascending aorta aneurysms. Methods and Materials: Thirty patients referred for ECG-gated CT thoracic angiography (64-row CT scanner) were evaluated. Measurements of the maximum and minimum ascending aorta diameters were obtained automatically with a commercially available CAD and semi-manually by two observers separately. The CAD algorithms segment the iv-enhanced lumen of the ascending aorta into perpendicular planes along the centreline. The CAD then determines the largest and the smallest diameters. Both observers repeated the automatic measurements and the semimanual measurements during a different session at least one month after the first measurements. The Bland and Altman method was used to study the inter/intraobserver variability. A Wilcoxon signed-rank test was also used to analyse differences between observers. Results: Interobserver variability for semi-manual measurements between the first and second observers was between 1.2 to 1.0 mm for maximal and minimal diameter, respectively. Intraobserver variability of each observer ranged from 0.8 to 1.2 mm, the lowest variability being produced by the more experienced observer. CAD variability could be as low as 0.3 mm, showing that it can perform better than human observers. However, when used in nonoptimal conditions (streak artefacts from contrast in the superior vena cava or weak lumen enhancement), CAD has a variability that can be as high as 0.9 mm, reaching variability of semi-manual measurements. Furthermore, there were significant differences between both observers for maximal and minimal diameter measurements (p<0.001). There was also a significant difference between the first observer and CAD for maximal diameter measurements with the former underestimating the diameter compared to the latter (p<0.001). As for minimal diameters, they were higher when measured by the second observer than when measured by CAD (p<0.001). Neither the difference of mean minimal diameter between the first observer and CAD nor the difference of mean maximal diameter between the second observer and CAD was significant (p=0.20 and 0.06, respectively). Conclusion: CAD algorithms can lessen the variability of diameter measurements in the follow-up of ascending aorta aneurysms. Nevertheless, in non-optimal conditions, it may be necessary to correct manually the measurements. Improvements of the algorithms will help to avoid such a situation.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

PFC de los estudios de Ingeniería Informática, del área .NET, desarrollado conforme a la propuesta "Iluminando el escritorio, la web y la nube con Microsoft Silverlight".