740 research outputs found

    Multi-agent opportunism

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    The real world is a complex place, rife with uncertainty; and prone to rapid change. Agents operating in a real-world domain need to be capable of dealing with the unexpected events that will occur as they carry out their tasks. While unexpected events are often related to failures in an agent\u27s plan, or inaccurate knowledge in an agent\u27s memory, they can also be opportunities for the agent. For example, an unexpected event may present the opportunity to achieve a goal that was previously unattainable. Similarly, real-world multi-agent systems (MASs) can benefit from the ability to exploit opportunities. These benefits include the ability for the MAS itself to better adapt to its changing environment, the ability to ensure agents obtain critical information in a timely fashion, and improvements in the overall performance of the system. In this dissertation we present a framework for multi-agent opportunism that is applicable to open systems of heterogeneous planning agents. The contributions of our research are both theoretical and practical. On the theoretical side, we provide an analysis of the critical issues that must be addressed in order to successfully exploit opportunities in a multi-agent system. This analysis can provide MAS designers and developers important guidance to incorporate multi-agent opportunism into their own systems. It also provides the fundamental underpinnings of our own specific approach to multi-agent opportunism. On the practical side, we have developed, implemented, and evaluated a specific approach to multi-agent opportunism for a particular class of multi-agent system. Our evaluation demonstrates that multi-agent opportunism can indeed be effective in systems of heterogeneous agents even when the amount of knowledge the agents share is severely limited. Our evaluation also demonstrates that agents that are capable of exploiting opportunities for their own goals are also able, using the same mechanisms, to recognize and respond to potential opportunities for the goals of other agents. Further and perhaps more interesting, we show that under some circumstances, multi-agent opportunism can be effective even when the agents are not themselves capable of single-agent opportunism

    PICES Press, Vol. 10, No. 2, July 2002

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    International symposium on North Pacific transitional areas [pp. 1-4] [pdf, 0.8 Mb] PICES Volunteer Observing Ship (VOS) Workshop [pp. 5-7] [pdf, 0.3 Mb] Joint meeting on Causes of marine mortality of salmon [pp. 8-9] [pdf, 0.3 Mb] The state of the western North Pacific in the second half of 2001 [pp. 10-11] [pdf, 0.5 Mb] State of the eastern North Pacific in spring 2002 [pp. 12-13] [pdf. 0.4 Mb] The status of the Bering Sea in the second half of 2001 [pp. 14-15] [pdf. 0.3 Mb] PICES Workshop on “Perturbation analysis” on subarctic Pacific gyre ecosystem models [pp. 16-17] [pdf. 0.4 Mb] Status and future plans for SOLAS-Japan [pp. 18-20] [pdf. 0.5 Mb] China-Korea Joint Ocean Research Center: A bridge across the Yellow Sea to connect Chinese and Korean oceanographic institutes and scientists [pp. 21-22] [pdf. 0.3 Mb] Persistent changes in the California Current ecosystem [pp. 23-24] [pdf. 0.2 Mb] The Hokusei Maru: 53 years of research in the Pacific [pp. 25-28] [pdf. 0.5 Mb] First meeting of the CLIVAR Pacific Panel [pp. 29-30] [pdf. 0.3 Mb] Call for contributions to the North Pacific Ecosystem Status Report [p. 31] [pdf. 0.2 Mb] PICES announcements [p. 32] [pdf. 0.2 Mb

    Strengthening Europe's Capability in Biological Ocean Observations

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    This publication is primarily aimed at stakeholders involved in ocean observing, spanning diverse roles from commissioning, managing, funding and coordinating, to developing, implementing, or advising on, ocean observation programmes. Such programmes will have strategic and policy drivers but their main purpose may vary from predominantly researchdriven scientific purposes to environmental monitoring for providing data and reporting to legally-binding regulations or directives. The main focus is on European capabilities but set in a global context with the various actors spanning a variety of geographical scales from national to regional and European. Key stakeholder organizations include environmental or other agencies; marine research institutions, their researchers and operators; international and regional ocean observing initiatives and programmes; national, regional and European policy makers and their advisors; national stations for observations; etc.). It will also be of interest to the wider marine and maritime research and policy community. The main aim of the publication is to increase the relevance of current (and future) European biological ocean observation capacity to strengthen global efforts towards our understanding of the ocean and enhance marine biodiversity conservation, for maintaining a healthy ocean for healthy societies. This document explains why biological ocean observations are needed to assess progress against national and international conservation targets, the Sustainable Development Goals (SDGs), the Blue Growth agenda and to contribute to key EU directives including the Marine Strategy Framework Directive (MSFD). To achieve this, the publication highlights the need of biological ocean observations to reflect clearly defined hypotheses about potential causes of change, including the combined impacts of local and global drivers, and to support the management of our impacts on the ocean. Additionally, it calls for flexible biological ocean observing programmes to capture the relevant drivers operating at multiple spatial scales, by networking and integration of ongoing monitoring programmes, methodological standardization and appropriate policies of data integration and dissemination. It then presents key variables, elements and information products to inform on the status and trends of marine biodiversity

    Proceedings of the Ocean Climate Data Workshop

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    The First Consultative Meeting on Responsible National Oceanographic Data Centres (RNODC's) and Climate DataServices met in February 1988 and made a number of recommendations related to improving services to meet the needs of climate programmes. Included in these discussions was a recommendation for a Workshop on Ocean Climate Data Management. This workshop will be talking about ways to establish a Global Ocean Observing System (GOOS)

    IMOS national reference stations: A continental-wide physical, chemical and biological coastal observing system

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    Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology

    Special Libraries, September 1975

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    Volume 66, Issue 9https://scholarworks.sjsu.edu/sla_sl_1975/1007/thumbnail.jp

    Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems

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    Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment

    PICES Press, Vol. 25, No. 2, Summer 2017

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    2017 Inter-sessional Science Board Meeting (pp. 1-4); Highlights from the FUTURE SSC’s 3rd Inter-sessional Meeting (pp. 5-6); WG 35 (WG-NPESR3) meets inter-sessionally in Honolulu (pp. 7-8); PICES/ICES International Symposium on “Drivers of dynamics of small pelagic fish resources” (pp. 9-12); SPF Workshop on “Environmental control of spatio-temporal changes in population size, distribution and migration of small pelagic fish in an ecosystem context” (pp. 13-15); SPF Workshop on “Methods and techniques for sampling and assessing small pelagic fish populations” (16-17); SPF Workshop on “Modeling migratory fish behavior and distribution” (pp. 18-19); SPF Workshop on “Recent advances in the life stage ecophysiology of small pelagic fish” (pp. 20-21); SPF Workshop on “Remote sensing and ecology of small pelagics” (pp. 22-23); SPF Workshop on “Simulation approaches of forage fish populations for management strategy evaluations” (pp. 24-26); An ICES/PICES Workshop on “Understanding the impacts and consequences of ocean acidification for commercial species and end-users” (pp. 27-28); The 26th International Hydrological Program (IHP) training course on “Coastal vulnerability and freshwater discharge” (pp. 29-30); PICES/MAFF MarWeb project collaborates with the United Nations program on the development of Marine Protected Areas in Guatemala (pp. 31-34); Program of topic sessions and workshops at PICES-2017 (pp. 35-35); The 3rd PICES/ICES Early Career Scientist Conference takes place in Busan, Korea (pp. 36-39); The Bering Sea: Current status and recent trends (pp. 40-42); The state of the western North Pacific during the 2016 warm season (pp. 43-44
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