56 research outputs found

    A Graph Theoretic Approach for Object Shape Representation in Compositional Hierarchies Using a Hybrid Generative-Descriptive Model

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    A graph theoretic approach is proposed for object shape representation in a hierarchical compositional architecture called Compositional Hierarchy of Parts (CHOP). In the proposed approach, vocabulary learning is performed using a hybrid generative-descriptive model. First, statistical relationships between parts are learned using a Minimum Conditional Entropy Clustering algorithm. Then, selection of descriptive parts is defined as a frequent subgraph discovery problem, and solved using a Minimum Description Length (MDL) principle. Finally, part compositions are constructed by compressing the internal data representation with discovered substructures. Shape representation and computational complexity properties of the proposed approach and algorithms are examined using six benchmark two-dimensional shape image datasets. Experiments show that CHOP can employ part shareability and indexing mechanisms for fast inference of part compositions using learned shape vocabularies. Additionally, CHOP provides better shape retrieval performance than the state-of-the-art shape retrieval methods.Comment: Paper : 17 pages. 13th European Conference on Computer Vision (ECCV 2014), Zurich, Switzerland, September 6-12, 2014, Proceedings, Part III, pp 566-581. Supplementary material can be downloaded from http://link.springer.com/content/esm/chp:10.1007/978-3-319-10578-9_37/file/MediaObjects/978-3-319-10578-9_37_MOESM1_ESM.pd

    'Thinking like a fish': adaptive strategies for coping with vulnerability and variability emerging from a relational engagement with kob

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    Based on ethnographic fieldwork amongst a group of commercial handline fishers in the town of Stilbaai in South Africa's southern Cape region, this paper presents a range of flexible, adaptive and evolving strategies through which fishers negotiate constantly shifting variability in weather patterns, fish stocks, fisheries policies, and economic conditions. These variabilities constitute a diverse set of vulnerabilities to which fishers must respond in order to sustain their livelihoods. In this context, the act of 'thinking like a fish' on the part of the fishers provides them with an effective means of adapting to variability and uncertainty. Findings of ethnographic research in 2010-11 suggest that a number of the fishers who participated in the research actively work towards achieving a balance between profit and sustainability. 'Thinking like a fish' is an embodied, interactive way of knowing that emerges from interactions between fishers and fish, offering an ethical and ecological outlook which is a valuable resource for fisheries and conservation management in the region. We suggest that the deeply embodied interactional component of 'thinking like a fish' results from a desire to understand the life world of fish and to think from their perspective in order to more effectively target them while sustaining the species and ecosystem

    Challenges for Implementing an Ecosystem Approach to Fisheries Management

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    The ecosystem approach is being promoted as the foundation of solutions to the unsustainability of fisheries. However, because the ecosystem approach is broadly inclusive, the science for its implementation is often considered to be overly complex and difficult. When the science needed for an ecosystem approach to fisheries is perceived this way, science products cannot keep pace with fisheries critics, thus encouraging partisan political interference in fisheries management and proliferation of “faith-based solutions. In this paper we argue that one way to effectively counter politicization of fisheries decision-making is to ensure that new ecosystem-based approaches in fisheries are viewed only as an emergent property of innovation in science and policy. We organize our essay using three major themes to focus the discussion: empirical, jurisdictional, and societal challenges. We undertake at least partial answers to the following questions: (1) has conventional fisheries management really failed?; (2) can short-comings in conventional fisheries management be augmented with new tools, such as allocation of rights?; (3) is the Ecosystem Approach to Fisheries (EAF) equivalent to Ecosystem-Based Management?; and (4) is restoration of degraded ecosystems a necessary component of an EAF

    Toward Self-Referential Autonomous Learning of Object and Situation Models

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    Most current approaches to scene understanding lack the capability to adapt object and situation models to behavioral needs not anticipated by the human system designer. Here, we give a detailed description of a system architecture for self-referential autonomous learning which enables the refinement of object and situation models during operation in order to optimize behavior. This includes structural learning of hierarchical models for situations and behaviors that is triggered by a mismatch between expected and actual action outcome. Besides proposing architectural concepts, we also describe a first implementation of our system within a simulated traffic scenario to demonstrate the feasibility of our approach

    Introduction: Coping with global change in marine social-ecological systems

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    Marine social-ecological systems are complex, inter-connected, and highly dynamic, in particular when forced with global changes. However, their human social components are often treated separately from their biophysical components, and by different scientific disciplines. To help bridge these gaps, and to explore conceptual, comparative, and governance issues relating to marine social-ecological systems and global change, an international symposium was held on "Coping with global change in marine social-ecological systems". This short paper provides an introduction to this topic, and briefly describes nine papers which arose from this symposium and which comprise this special issue of Marine Policy. It is concluded that good progress is being made towards studying marine social and ecological systems as coupled systems, but that many issues remain to challenge natural scientists, social scientists, and humanists to work together. These include incorporating multi-stakeholder participation, the need for a long-term perspective, and development of flexible livelihood and governance strategies.Social-ecological systems Global change Fishing communities Marine ecosystems Vulnerability

    Social–ecological dynamism, knowledge, and sustainable coastal marine fisheries

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    To understand and mitigate the increasingly rapid and complex global and local changes of coastal marine social–ecological systems in such a manner as to ensure their sustainability requires both recognising the dynamic nature of the interactions within and between these systems, and drawing on insights from different types of knowledge and knowledgegenerating systems. This requires the systematic collection, comparison and (where feasible) integration of scientists’ and stakeholders’ knowledge from a broad range of natural and social science and humanities backgrounds, different social– ecological locations (spatial, temporal and organisational), local experiences and traditional practices, as well as formal knowledge. Considered separately, each of these groups can only throw light on how a part of the system is changing and, because of interactivity and complexity, may sometimes misunderstand what is actually happening, its social and environmental consequences, and the available options and alternatives for change. We suggest ways in which integration of the various knowledge bases for fisheries management might be achieved, and the types of governance infrastructure that would need to be put in place

    World Fisheries - A Social-Ecological Analysis

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    This exciting new book grew out of an international symposium held at FAO, Rome in July 2008, but it is not just a collection of papers from that symposium. Rather, the publication brings together work on social-ecological marine research that cuts across disciplines, identifies key common elements and approaches that promote resilience of marine social-ecological systems in the face of global changes, and points to next steps. The book comprises contributions on conceptual issues relating to social-ecological responses in marine systems to global changes; offers illustrative case studies of specific examples of social-ecological responses in marine systems to significant environmental changes manifested locally; develops a syntheses between natural and social scientists on the topic, and points the way forward with innovative approaches to the use of science and knowledge in management, policy and advice. World Fisheries is part of Wiley-Blackwell's prestigious Fish and Aquatic Resources Series, and encompasses chapters from many scientists at the top of their fields worldwide. Carefully drawn together and edited by four world experts in the area, World Fisheries is a landmark publication which is an essential purchase for all fisheries managers worldwide
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