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- Soundserver: data sonification on-demand for computationalPublication . Cardoso, Jorge C. S.; Carvalho, José; Teixeira, Luis Miguel Lopes; Barbosa, ÁlvaroThe rapid accumulation of large collections of data has created the need for efficient and intelligent schemes for knowledge extraction and results analysis. The resulting information is typically visualized, but it may also be presented through audio techniques such as sonification. Sonification techniques become especially interesting when the client application runs on graphically limited devices such as mobile phones or PDAs (Personal Digital Assistants). In this paper we present an architecture for a sonification server that will be used in the Sound Data Mining project. In this project sound will be used to increase perception and present information extracted by spatial data mining techniques. The server is based on an audio synthesis engine and will relieve clients with little audio synthesis capabilities from the burden of sound processing. By providing sonification modules, this server can potentially be used on a variety of applications where sonification techniques are required
- Online data mining services for dynamic spatial databases I: system architecture and client applicationsPublication . Costa, Manuel; Sousa, Inês; Fonseca, Alexandra; Henriques, Diana; Rosa, Paulo; Franco, Ivan; Capeta, Nuno; Teixeira, Luis Miguel Lopes; Cardoso, Jorge C. S.; Carvalho, VascoThis paper describes online data mining services for dynamic spatial databases connected to environmental monitoring networks. These services can use Artificial Neural Networks as data mining techniques to find temporal relations in monitored parameters. The execution of the data mining algorithms is performed at the server side and a distributed processing scheme is used to overcome problems of scalability. To support the discovery of temporal relations, two other families of online services are made available: vectorial and raster visualization services and a sonification service. The use of this system is illustrated by the DM Plus client application and the SNIRH Data Mining Web site. The sonification service is described and illustrated in the part II paper.
- Generic Framework for Video AnalysisPublication . Tavares, Luís Filipe; Teixeira, Luis Miguel Lopes; Corte-Real, LuísIn this paper we propose a framework for development of video analysis and description systems, in an easy and interactive way. Due to the architecture design the developed software can run on different operating systems and on distributed environments.
- Comunicação e ciência a partir das questões éticas das ciências da vidaPublication . Carvalho, Mónica; Araújo, Joana; Costa, Joana Cunha; Teixeira, Luis Miguel Lopes; Carvalho, Ana SofiaEste trabalho pretende apresentar o projecto de investigação Ciência e Sociedade: promovendo a cidadania através da reflexão sobre as questões éticas das ciências da vida. Trata-se de uma iniciativa conjunta do Gabinete de Investigação em Bioética “GIB e do Centro de Investigação em Ciências e Tecnologias das Artes” CITAR, ambos da Universidade Católica Portuguesa. A partir de um modelo transdisciplinar de investigação, pretende-se partir da reflexão ética sobre as questões suscitadas pelo desenvolvimento das ciências da vida e estudar e desenvolver novas metodologias e ferramentas comunicacionais, audiovisuais e digitais. Em virtude do universo que se quer auscultar; dos temas abordados e do desenvolvimento técnico e metodológico que se pretende promover em comunicação e ciência, pode-se afirmar que se trata de um projecto complexo. O planeamento do projecto constituir-se-á por diversas fases de investigação. Numa fase inicial, pretende-se realizar um inquérito nacional à população portuguesa visando a análise do potencial crítico da população sobre as diversas temáticas da bioética e das ciências da vida. Posteriormente, e também em função dos resultados do inquérito, propõem-se estudos de recepção dos diversos públicos em Portugal para obter dados acerca do modo como as informações circulam na interacção entre os públicos e diversos media. De seguida, devem-se desenvolver estratégias e ferramentas para a comunicação da ciência e participação do público em questões que podem afectar directa ou indirectamente as suas vivências. As estratégias a desenvolver incluirão sempre ferramentas multimédia a serem criadas no âmbito do projecto.
- H.264 Rate-Distortion Analysis Using Subjective Quality MetricPublication . Teixeira, Luis Miguel Lopes; Corte-Real, LuísIn this paper we provide an analysis of rate-distortion (R-D) relationship in an H.264 codec using as quality metric Structural Similarly Information (SSIM). This study focus on the quantization parameter, namely rate-quantization (R-Q) functions and distortion-quantization (D-Q) functions. Together, these functions allow a better understanding of the rate-distortion (RD) behaviour of an H.264 video codec, which is the key issue of optimum bit allocation. Initial results are presented and discussed.
- Statistical Multiplexing of H.264 video streams using Structural Similarity InformationPublication . Teixeira, Luis Miguel Lopes; Corte-Real, LuísIn this paper, we propose a method to broadcast digital video programs in which the channel capacity is dynamically distributed among video programs according to each video program particular complexity. A bit rate control algorithm based on the Structural Similarity Index as the measure of video program complexity is examined. Initial results show that a uniform picture quality among video programs can be obtained.
- Joint Coding of multiple H.264 video programsPublication . Teixeira, Luis Miguel Lopes; Corte-Real, LuísThis paper presents a joint coding scheme for multiple H.264/AVC video programs. Channel bandwidth is divided among different programs according its complexity. Several complexity metrics are assessed. Initial results are presented and discussed.
- Online data mining services for dynamic spatial databases II: air quality location based services and sonificationPublication . Teixeira, Luis Miguel Lopes; Barbosa, Álvaro; Cardoso, Jorge C. S.; Carvalhos, Vasco; Costa, Manuel; Sousa, Inês; Franco, Ivan; Fonseca, Alexandra; Henriques, Diana; Rosa, PauloThis paper introduces online data mining services for dynamic spatial databases associated with environmental monitoring networks. In particular, it describes an application that uses these services with sonification for air quality location based information services to the general public. The data mining services use Artificial Neural Networks, to find temporal relations in the monitored parameters. The execution of the algorithms performed at the server side and a distributed processing scheme is used to overcome problems of scalability. In addition, two other families of web services are made available to support the discovery of temporal relations: vectorial and raster map? services and a sonification service. The map services were implemented in DM Plus, a client application presented in part I. The sonification service is described in this paper and illustrated through an application study that implements an air quality index with sonification for mobile phones.
- A novel approach to joint video codingPublication . Teixeira, Luis Miguel Lopes; Corte-Real, LuísIt is expected that future delivery of Digital TV signals will use H.264. This paper presents a novel coding scheme for multi-program video transmission in which the channel capacity is distributed among the programs according to the program complexities resulting in a more uniform overall image quality. A complexity bit rate control algorithm based on the Structural Similarity Index (SSIM) is proposed. SSIM metric is presented under the hypothesis that the Human Visual System (HSV) is very specialized in extracting structural information from a video sequence but not in extracting the errors. Thus, a measurement on structural distortion should give a better correlation to the subjective impression. Computer simulations have demonstrated very promising results showing joint coding is able to effectively control the complexity of the multi-program encoding process whilst improving overall subjective compared to independent coding and algorithms based on traditional distortion/quality metrics.
- Statistical Multiplexing of H.264 programmsPublication . Teixeira, Luis Miguel Lopes; Corte-Real, LuísThe advent of H.264/AVC is going to change the way Digital Television programs are broadcast. Each program can be independently encoded or jointly encoded resulting thus in a more efficient way to distribute the available channel bandwidth. This paper presents a combined coding scheme for multi-program video transmission in which the channel capacity is distributed among the programs according to the program complexities. A complexity bit rate control algorithm based on the Structural Similarity Index (SSIM) is proposed. SSIM metric is presented under the hypothesis that the Human Visual System (HSV) is very specialized in extracting structural information from a video sequence but not in extracting the errors. Thus, a measurement on structural distortion should give a better correlation to the subjective impression. Current simulations have demonstrated very promising results showing that the algorithm can effectively control the complexity of the multi-program encoding process whilst improving overall subjective.