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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Face Detection using Swarm Intelligence

Lang, Andreas January 2010 (has links)
Groups of starlings can form impressive shapes as they travel northward together in the springtime. This is among a group of natural phenomena based on swarm behaviour. The research field of artificial intelligence in computer science, particularly the areas of robotics and image processing, has in recent decades given increasing attention to the underlying structures. The behaviour of these intelligent swarms has opened new approaches for face detection as well. G. Beni and J. Wang coined the term “swarm intelligence” to describe this type of group behaviour. In this context, intelligence describes the ability to solve complex problems. The objective of this project is to automatically find exactly one face on a photo or video material by means of swarm intelligence. The process developed for this purpose consists of a combination of various known structures, which are then adapted to the task of face detection. To illustrate the result, a 3D hat shape is placed on top of the face using an example application program.:1 Introduction 1.1 Face Detection 1.2 Swarm Intelligence and Particle Swarm Optimisation Fundamentals 3 Face Detection by Means of Particle Swarm Optimisation 3.1 Swarms and Particles 3.2 Behaviour Patterns 3.2.1 Opportunism 3.2.2 Avoidance 3.2.3 Other Behaviour Patterns 3.3 Stop Criterion 3.4 Calculation of the Solution 3.5 Example Application 4 Summary and Outlook
12

Optimal color channel combination across skin tones for remote heart rate measurement in camera-based photoplethysmography

Ernst, Hannes, Scherpf, Matthieu, Malberg, Hagen, Schmidt, Martin 16 September 2022 (has links)
Objective: The heart rate is an essential vital sign that can be measured remotely with camera-based photoplethysmography (cbPPG). Systems for cbPPG typically use cameras that deliver red, green, and blue (RGB) channels. The combination of these channels has been proven to increase signal-to-noise ratio (SNR) and heart rate measurement accuracy (ACC). However, many combinations remain untested, the comparison of proposed combinations on large datasets is insufficiently investigated, and the interplay with skin tone is rarely addressed. Methods: Eight regions of interest and eight color spaces with a total of 25 color channels were compared in terms of ACC and SNR based on the Binghamton-Pittsburgh-RPI Multimodal Spontaneous Emotion Database (BP4D+). Additionally, two systematic grid searches were performed to evaluate ACC in the space of linear combinations of the RGB channels. Results: Glabella and forehead regions of interest provided highest ACC (up to 74.1 %) and SNR (> -3 dB) with the hue channel H from HSV color space and the chrominance channel Q from NTSC color space. The grid searches revealed a global optimum of linear RGB combinations (ACC: 79.2 %). This optimum occurred for all skin tones, although ACC dropped for darker skin tones. Conclusion: Through systematic grid searches we were able to identify the skin tone independent optimal linear RGB color combination for measuring heart rate with cbPPG. Our results proved on a large dataset that the identified optimum outperformed conventionally used color channels. Significance: The presented findings provide useful evidence for future considerations of algorithmic approaches for cbPPG.
13

O circuito espacial da ind?stria de cer?mica vermelha no serid? potiguar

Nascimento, Judicleide de Azevedo 07 April 2011 (has links)
Made available in DSpace on 2015-03-13T17:10:46Z (GMT). No. of bitstreams: 1 JudicleideAN_DISSERT.pdf: 1718775 bytes, checksum: 1c64b7a22a787d96b10f62b600bd2ba2 (MD5) Previous issue date: 2011-04-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This research has as an empirical universe, the productive territory of red ware in the Serid? region of Rio Grande do Norte. In the last years this territory has gone through a process of appropriation that has been substantially changing the environmental and social dynamism of the place. However, the industry of red ware has been focusing in some areas, mainly, in the county of Parelhas and Carna?ba dos Dantas. From this point of view, the aim of this work consists in analyze the use of these areas by the red ware industry and the transformations occurred with the expansion of the number of industries and the productivity raise, that requires bigger amounts of earthenware and wood, resources that are low in referred territory. As the result of this process, the suitable alternative has been to acquire inputs in other Rio Grande do Norte counties, as well as in Para?ba counties. To reach the proposed objective, the methodology of this work was consisted of bibliographic and empirical research, regarding the occupation that this activity covers in the Serid? region. From the information obtained during the research, it can be stated that the inputs to the production execution in the red ware industry are acquired in the geographic nearby lands. The analysis of the stages of the production(acquisition of raw material, production and commercialization) showed that the activity acts in a continuous area, having as principal consumer market other northeastern states and the state of Par?. The present study revealed that the pottery activity is set as untenable, because of non-stopping use of the argil and wood, resources that are vanishing from the area, which consume causes a many problems such as deforestation and erosion. Besides, the sale of productive lands for the red ware industries makes harder its good use by the familiar agriculturists in the development of agriculture and cattle raising activity, which for many times is the main economic activity of the place. The precariousness reveals in the constant accidents at work, that most of them are neglected by the local authorities, without any penalty to the industries. Therefore, the industry of red ware in Serid? uses the territory as a resource, leaving its environmental problems that my compromise the quality of life of the actual and future generations / Esta pesquisa tem como universo emp?rico, o territ?rio produtor de cer?mica vermelha no Serid? potiguar. Nos ?ltimos anos esse territ?rio passou por um processo de apropria??o que tem alterado substancialmente a din?mica social e ambiental do lugar. No Serid?, a ind?stria de cer?mica vermelha tem se concentrado em algumas ?reas, sobretudo, nos munic?pios de Parelhas e Carna?ba dos Dantas. Nesta perspectiva, o objetivo desse trabalho consiste em analisar o uso do territ?rio pela ind?stria de cer?mica vermelha e as transforma??es ocorridas com a expans?o no n?mero de ind?strias e no aumento da produtividade, o que requer maiores quantidades de argila e de lenha, recursos escassos no referido territ?rio. Em decorr?ncia desse processo, a alternativa encontrada tem sido adquirir os insumos em outros munic?pios do Rio Grande do Norte, como tamb?m em munic?pios paraibanos. Para alcan?ar o objetivo proposto, o encaminhamento metodol?gico envolveu pesquisa bibliogr?fica e emp?rica, considerando a espacializa??o que essa atividade abrange no territ?rio seridoense. A partir das informa??es obtidas durante a pesquisa pode-se afirmar que os insumos para a realiza??o da produ??o na ind?stria de cer?mica vermelha s?o adquiridos no seu entorno geogr?fico. A an?lise das etapas do circuito de produ??o (aquisi??o da mat?ria-prima, produ??o e comercializa??o) mostrou que esta atividade atua numa ?rea cont?nua, tendo como principal mercado consumidor os demais estados do Nordeste e o estado do Par?. O presente estudo revelou ainda que a atividade ceramista configura-se como insustent?vel, haja vista a recorr?ncia permanente ? argila e ? lenha, insumos escassos no territ?rio, cuja aquisi??o provoca uma s?rie de problemas como o desmatamento e a eros?o. Al?m disso, a venda dos solos f?rteis para as cer?micas dificulta o seu aproveitamento pelos agricultores familiares, no desenvolvimento das atividades agropecu?rias, que muitas vezes configura-se na principal atividade econ?mica da propriedade. A precariedade da atividade se revela nos constantes acidentes de trabalho, que na grande maioria, s?o negligenciados pelas autoridades locais, sem aplica??o de nenhuma penalidade ?s empresas. Assim, a ind?stria de cer?mica vermelha no Serid? usa o territ?rio de forma seletiva e excludente, deixando s?rias problem?ticas ambientais, as quais podem comprometer a qualidade de vida das atuais e futuras gera??es

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