Biology, fisheries and culture of tropical groupers and snappers

Groupers and snappers are important fishery resources of the tropics and subtropics, where their high values have caused most of their stocks to be heavily exploited, some even to the point of collapse. Trends towards heavy demand and decreasing natural supply, which are accelerating in several parts of the world, prompted various mariculture ventures. Focused research on biology and the population dynamics of groupers and snappers, and on their reproduction and growth under controlled condition will remain essential for dealing with the questions on how to better manage their fisheries. This volume of papers presents important scientific findings and views on these two important groups of fish.Percoid fisheries, Fishery biology, Fishery management, Conferences

Ultrasound Imaging

In this book, we present a dozen state of the art developments for ultrasound imaging, for example, hardware implementation, transducer, beamforming, signal processing, measurement of elasticity and diagnosis. The editors would like to thank all the chapter authors, who focused on the publication of this book

Words to Live By: How Experience Shapes our Information World at Work, Play and in Everyday Life

Background: A considerable amount of effort has been spent studying information behaviours and practices associated with formal, professional contexts and documentary, tangible sources of information. Comparatively, relatively little is known about non–documentary and experience-based information found in informal, nonformal, blue collar and rural contexts. Experiences of everyday life are often neglected from a research standpoint because they are seen as common, familiar, and unremarkable. Research Question: By exploring familiar experiences of everyday life in one specific, marginalized context, my goals were to contribute to the body of interdisciplinary literature describing non–problem–based phenomena and non–documentary, experience-based sources of information; to extend our understanding of work, leisure and everyday life information practices in informal and non-professional contexts; and to elevate these less frequently studied experiences and information sources above the trivial theoretically. To address this gap, the present study asks, what is the nature of experience in the remote, rural village of Whitney, Ontario, Canada across the domains of work, leisure and maintenance activities? Method: I interviewed 24 adult residents of the village ranging in age from their early twenties to their late eighties using a semi–structured interview protocol. I also gathered data through several photo–methodologies including documentary photography, photo–voice, and photo–elicitation. Printed documentary evidence reflecting experiences in the village were obtained through environmental scanning. I analyzed data according to grounded theory from the perspective of everyday life information seeking theories, drawing support from serious leisure, lifelong learning, and experiential education theories where appropriate. Discussion: Reinforcing previous Information Behaviour theory, results show that informal information channels and interpersonal sources are frequently preferred over formal ones, and that contextual factors continue to influence information seeking and use across the domains of work, play and everyday life. More study is required to explain the characteristics and qualities that insulate small worlds like this from information poverty, as well as the effects of interruptions in the network of interpersonal sources relied on heavily in this context. This research also highlights how the social characteristics of information seeking and use add depth to discussions of leisure experiences. A working definition of experiential information is provided. Keywords: Experiential Information, Everyday Life Information Seeking (ELIS), Informal Information Behaviours, Information Poverty, Information Seeking Behaviours, Information Seeking and Use (ISU), Rural Information Seeking, Tacit Knowledge, Leisure Experience, Everyday Life Experienc

Xenomai Lab: uma plataforma para controlo digital em tempo-real

Mestrado em Engenharia Electrónica e TelecomunicaçõesXenomai Lab is a free software suite that allows a user to graphically design control systems using block diagrams. The designed system can be executed in real-time with operating frequencies of up to 10KHz using the Xenomai framework. Execution can be merely a numerical simulation or an interaction with the real-world via input/output blocks. Several useful blocks are included in the default installation, such as an oscilloscope, a signal generator, MATLAB setpoint profile loader, and others. A rich set of documentation and examples is also provided. Development of Xenomai Lab was supported by a thorough study of real-time operating systems based on GNU/Linux. The performances of standard Linux, the PREEEMPT_RT patchset, RTAI and Xenomai were benchmarked using a standard test. This allowed for a direct comparison between them. Xenomai was found to have the ideal balance between performance and ease of use, with scheduling jitter bellow 35μs on a desktop computer. Ease of use was one of Xenomai Lab’s main goals. This distinguishes it from alternatives. Control algorithms are programmed in C and no prior knowledge of Xenomai, or real-time operating systems in general for that matter, is needed. This makes our system adequate for use by control engineers unfamiliar with GNU/Linux and by entry level students of control engineering, robotics, and other equally technical areas. Advanced users will feel right at home.O Xenomai Lab é uma plataforma open-source que permite a um utilizador projectar gráficamente um sistema de controlo recorrendo a um diagrama de blocos. O sistema projectado pode ser executado em tempo-real a uma frequência de operação de até 10KHz pela framework de tempo-real Xenomai. Execução pode ser uma mera simulação numérica, ou uma interacção com o mundo real recorrendo a blocos de input e output. A instalação traz de origem vários blocos potencialmente úteis, como um osciloscópio, um gerador de sinais, interface com perfis de setpoint feitos em MATLAB, entre outros. É também incluída documentação e alguns exemplos ilustrativos. O desenvolvimento do Xenomai Lab teve por base uma pesquisa exaustiva de sistemas operativos de tempo-real baseados em GNU/Linux. As performances de Linux, do patch PREEEMPT_RT, do RTAI e do Xenomai foram medidas recorrendo a um mesmo teste. Desta forma, tornou-se possível fazer uma comparação directa entre as diferentes tecnologias. De acordo com os nossos testes, o Xenomai apresenta um balanço ideal entre performance e facilidade de utilização. O jitter de escalonamento esteve sempre abaixo de 35μs num computador de secretária. O Xenomai Lab foi desenvolvido de forma a ser fácil de utilizar. Esta é a característica chave que o distingue de software semelhante. Algoritmos de controlo são programados em linguagem C, não sendo necessário nenhum conhecimento específico de Xenomai ou mesmo de sistemas de tempo-real em geral. Assim, o Xenomai Lab é adequado para engenheiros da área de controlo sem experiência em GNU/Linux ou sistemas operativos de tempo-real ou mesmo estudantes de engenharia de controlo, robótica e outras áreas técnicas. Utilizadores avançados sentir-se-ão imediatamente em casa

Federal Register

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii