A Survey of Applications of Viability Theory to the Sustainable Exploitation of Renewable Resources
TL;DR: A survey of the literature applying viability theory to the sustainable management of renewable resources can be found in this article, where the authors provide a general map of the contributions and next discuss them by area of application, including ecosystems and population biology, climate change, forestry and others.
About: This article is published in Ecological Economics.The article was published on 2018-03-01. It has received 58 citations till now. The article focuses on the topics: Sustainability & Sustainable management.
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TL;DR: In this article, a systematic literature review was conducted focussing on the benefits of non-linear modes adoption, and the results show a high degree of convergence in findings, gaps and weaknesses of these literatures.
Abstract: This paper aims to investigate overlaps, complementarities and divergences between the literature on circular economy (CE) models and related literature in non-linear production models and frameworks, including CE, reverse logistics, closed-loop, industrial symbiosis and industrial ecology.,A systematic literature review was conducted focussing on the benefits of non-linear modes adoption.,The results show a high degree of convergence in findings, gaps and weaknesses of these literatures. Negative environmental, economic and operational impacts are understudied. There is a scarcity of studies identifying practices resulting in empirically tested benefits. The business and society case for non-linear production is still largely built upon conceptual studies, modelling and a few case studies. Despite a normative focus, there is very little use of theory, in particular, management theories.,First, the authors use only one, albeit highly recognized database, Scopus. This database may have omitted some relevant research, journals such as the Journal of Cleaner Production and Resources Conservation & Recycling that are more likely to publish such research and also have a more interdisciplinary approach. This is an important gap and interesting result to claim for more interdisciplinary research. Second, the filtering process used and the focus on Association of Business Schools top journals may have also omitted some relevant research, such as a large stream of literature in specialist journals such as Resources Conservation and Recycling and the Journal of Cleaner Production.,There are contradictions, tensions and epistemological ambiguity that needs to be critically addressed. Such tensions may be associated with the knowledge field that gave rise to these different non-linear production approaches. Many of them appeared at the same time, but from different sciences and disciplines with their own perspectives. Then in doing so, they create confusion in the definitions of CE, assumptions underlying modelling and business choices arising from this complexity. This can be minimized through the critical interpretation of knowledge to elucidate epistemological quandaries to improve the understanding of the economic, social and environmental impacts of practices.,In some way, this result makes sense, as the authors have limited the search to management, business and accounts journals, especially talking about Operations Management journals. This is an important gap and interesting result to claim for more interdisciplinary research.,In addition to gaps previously described, the authors identified areas of tensions where the literature offers inconclusive – often contradictory – findings requiring further exploration. A better understanding of these tensions is required to understand the impacts of non-linear production and develop policy guidelines for industry and policymakers to scale-up CE.
95 citations
TL;DR: In this paper, the reaction mechanisms and catalytic systems of γ-valerolactone (GVL) from various biomass-derived feedstocks were discussed and compared, and practical suggestions on improving the cost, stability and efficiency of the overall catalytic system were also proposed.
Abstract: As a natural renewable resource, the catalytic conversion of lignocellulosic biomass is considered to be an important strategy to alleviate the tremendous dependence on fossil resources. The synthesis of γ-valerolactone (GVL), which is hailed as a new-generation of biomass-based platform molecule, is one of the pivotal steps in the transformation of biomass resources into liquid fuels and high-value chemicals. The catalytic routes for the synthesis of GVL from lignocellulosic feedstocks have been continuously enriched and improved in recent years. Herein, our principal focus is the reaction mechanisms and catalytic systems of GVL from various biomass-derived feedstocks. The specific reaction routes and catalytic performances of GVL synthesis based on the traditional basic raw materials such as levulinic acid (LA) and alkyl levulinates (AL) were discussed and compared, and one-pot processes with cascade steps of cellulosic and hemicellulosic derivatives such as furfural (Fur), furfuryl alcohol (FAL) as well as cellulosic carbohydrates into GVL were also summarized and analyzed in detail. A more intuitive and comprehensive retrospection of the up-to-date literatures on GVL synthesis through multiple pathways was presented, and practical suggestions on improving the cost, stability and efficiency of the overall catalytic systems were also proposed.
87 citations
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TL;DR: In this article, a stochastic viability approach is proposed to address the trade-offs associated with balancing ecological, economic and social objectives in regulating mixed fisheries, taking into account the complexity and uncertainty of the dynamic interactions which characterize such fisheries.
Abstract: Management of fisheries for sustainability requires dealing with multiple and often conflicting objectives. A stochastic viability approach is proposed to address the trade-offs associated with balancing ecological, economic and social objectives in regulating mixed fisheries, taking into account the complexity and uncertainty of the dynamic interactions which characterize such fisheries. We focus on the demersal fishery in the Bay of Biscay and more specifically on the fleets harvesting Norway Lobster (Nephrops norvegicus), Hake (Merluccius merluccius) and Sole (Solea solea). A bio-economic multi-species and multi-fleet model with technical interactions is developed to examine the trade-offs between preserving Spawning Stock Biomass (SSB) of every species and maintaining the economic profitability of the various fishing fleets. Different management strategies are tested and compared. Results suggest that ensuring viability of this demersal fishery requires a significant decrease in fishing capacity as compared to the reference year. The simulations allow comparing the trade-offs associated with different allocations of this decrease across fleets.
58 citations
TL;DR: In this article, the catalytic system and reaction mechanism of each stage towards synthesizing sugar, levulinic acid, furfural (FAL), and GVL from the important biomass components cellulose and hemicellulose.
54 citations
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TL;DR: In this paper, a survey of 14 farms made it possible to characterise practices in llama flocks and in sheep flocks (high care and low care practices) and evaluate the efficiency of these practices using annual numerical productivity indexes.
Abstract: On the Bolivian arid highlands, breeders' strategies combining herd diversification (llamas and sheep) and the control of breeding rate were assessed under unpredictable environmental conditions. A survey of 14 farms made it possible to characterise practices in llama flocks (controlled and uncontrolled breeding practices) and in sheep flocks (high care and low care practices). The efficiency of these practices was evaluated using annual numerical productivity indexes. To assess the effectiveness of these practices, a dynamic model of mixed herds, based on the mathematical framework of the viability theory, was developed. The model made it possible to analyse the long-term interactions between management practices and climatic uncertainty on livestock system sustainability. Numerical productivity at weaning was found to be significantly lower in llama flocks managed with controlled breeding compared to uncontrolled breeding (44% and 70% respectively). For sheep, numerical productivity at weaning of high-care flocks was not significantly higher than that of low-care ones (83% and 69%, respectively). It was not possible to conclude whether high-care practices were more efficient in increasing numbers than low-care ones. On a long-term perspective, the dynamic analysis showed that the control of the llama flock breeding rate stabilises the evolution of the mixed herd only when a low offtake rate can satisfy a minimum income. Thus, foregoing short-term yield can be a sound strategy to insure mixed herd viability in an extremely harsh and unpredictable environment. However, the effectiveness of this practice is closely related to wealth (herd size). The model is discussed in terms of its heuristic value for assessing management practices and sustainability of pastoral systems.
40 citations
References
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Book•
01 May 1995TL;DR: The leading and most up-to-date textbook on the far-ranging algorithmic methododogy of Dynamic Programming, which can be used for optimal control, Markovian decision problems, planning and sequential decision making under uncertainty, and discrete/combinatorial optimization.
Abstract: The leading and most up-to-date textbook on the far-ranging algorithmic methododogy of Dynamic Programming, which can be used for optimal control, Markovian decision problems, planning and sequential decision making under uncertainty, and discrete/combinatorial optimization. The treatment focuses on basic unifying themes, and conceptual foundations. It illustrates the versatility, power, and generality of the method with many examples and applications from engineering, operations research, and other fields. It also addresses extensively the practical application of the methodology, possibly through the use of approximations, and provides an extensive treatment of the far-reaching methodology of Neuro-Dynamic Programming/Reinforcement Learning.
10,834 citations
Book•
[...]
01 Jan 1972
TL;DR: In this article, the authors investigate five major trends of global concern: accelerating industrialization, rapid population growth, widespread malnutrition, depletion of nonrenewable resources, and a deteriorating environment.
Abstract: Every person approaches problems with the help of models. A model is simply an ordered set of assumptions about a complex system. Our world model was built specifically to investigate five major trends of global concern—accelerating industrialization, rapid population growth, widespread malnutrition, depletion of nonrenewable resources, and a deteriorating environment. It is possible to alter the growth trends and to establish a condition of ecological and economic stability that is sustainable far into the future. The state of global equilibrium could be designed so that the basic material needs of each person on earth are satisfied and each person has an equal opportunity to realize his individual human potential. Although the history of human effort contains numerous incidents of mankind's failure to live within physical limits, it is success in overcoming limits that forms the cultural tradition of many dominant people in today's world.
5,312 citations
04 Aug 2011
TL;DR: This book discusses the challenges of dynamic programming, the three curses of dimensionality, and some experimental comparisons of stepsize formulas that led to the creation of ADP for online applications.
Abstract: Preface. Acknowledgments. 1. The challenges of dynamic programming. 1.1 A dynamic programming example: a shortest path problem. 1.2 The three curses of dimensionality. 1.3 Some real applications. 1.4 Problem classes. 1.5 The many dialects of dynamic programming. 1.6 What is new in this book? 1.7 Bibliographic notes. 2. Some illustrative models. 2.1 Deterministic problems. 2.2 Stochastic problems. 2.3 Information acquisition problems. 2.4 A simple modeling framework for dynamic programs. 2.5 Bibliographic notes. Problems. 3. Introduction to Markov decision processes. 3.1 The optimality equations. 3.2 Finite horizon problems. 3.3 Infinite horizon problems. 3.4 Value iteration. 3.5 Policy iteration. 3.6 Hybrid valuepolicy iteration. 3.7 The linear programming method for dynamic programs. 3.8 Monotone policies. 3.9 Why does it work? 3.10 Bibliographic notes. Problems 4. Introduction to approximate dynamic programming. 4.1 The three curses of dimensionality (revisited). 4.2 The basic idea. 4.3 Sampling random variables . 4.4 ADP using the postdecision state variable. 4.5 Lowdimensional representations of value functions. 4.6 So just what is approximate dynamic programming? 4.7 Experimental issues. 4.8 Dynamic programming with missing or incomplete models. 4.9 Relationship to reinforcement learning. 4.10 But does it work? 4.11 Bibliographic notes. Problems. 5. Modeling dynamic programs. 5.1 Notational style. 5.2 Modeling time. 5.3 Modeling resources. 5.4 The states of our system. 5.5 Modeling decisions. 5.6 The exogenous information process. 5.7 The transition function. 5.8 The contribution function. 5.9 The objective function. 5.10 A measuretheoretic view of information. 5.11 Bibliographic notes. Problems. 6. Stochastic approximation methods. 6.1 A stochastic gradient algorithm. 6.2 Some stepsize recipes. 6.3 Stochastic stepsizes. 6.4 Computing bias and variance. 6.5 Optimal stepsizes. 6.6 Some experimental comparisons of stepsize formulas. 6.7 Convergence. 6.8 Why does it work? 6.9 Bibliographic notes. Problems. 7. Approximating value functions. 7.1 Approximation using aggregation. 7.2 Approximation methods using regression models. 7.3 Recursive methods for regression models. 7.4 Neural networks. 7.5 Batch processes. 7.6 Why does it work? 7.7 Bibliographic notes. Problems. 8. ADP for finite horizon problems. 8.1 Strategies for finite horizon problems. 8.2 Qlearning. 8.3 Temporal difference learning. 8.4 Policy iteration. 8.5 Monte Carlo value and policy iteration. 8.6 The actorcritic paradigm. 8.7 Bias in value function estimation. 8.8 State sampling strategies. 8.9 Starting and stopping. 8.10 A taxonomy of approximate dynamic programming strategies. 8.11 Why does it work? 8.12 Bibliographic notes. Problems. 9. Infinite horizon problems. 9.1 From finite to infinite horizon. 9.2 Algorithmic strategies. 9.3 Stepsizes for infinite horizon problems. 9.4 Error measures. 9.5 Direct ADP for online applications. 9.6 Finite horizon models for steady state applications. 9.7 Why does it work? 9.8 Bibliographic notes. Problems. 10. Exploration vs. exploitation. 10.1 A learning exercise: the nomadic trucker. 10.2 Learning strategies. 10.3 A simple information acquisition problem. 10.4 Gittins indices and the information acquisition problem. 10.5 Variations. 10.6 The knowledge gradient algorithm. 10.7 Information acquisition in dynamic programming. 10.8 Bibliographic notes. Problems. 11. Value function approximations for special functions. 11.1 Value functions versus gradients. 11.2 Linear approximations. 11.3 Piecewise linear approximations. 11.4 The SHAPE algorithm. 11.5 Regression methods. 11.6 Cutting planes. 11.7 Why does it work? 11.8 Bibliographic notes. Problems. 12. Dynamic resource allocation. 12.1 An asset acquisition problem. 12.2 The blood management problem. 12.3 A portfolio optimization problem. 12.4 A general resource allocation problem. 12.5 A fleet management problem. 12.6 A driver management problem. 12.7 Bibliographic references. Problems. 13. Implementation challenges. 13.1 Will ADP work for your problem? 13.2 Designing an ADP algorithm for complex problems. 13.3 Debugging an ADP algorithm. 13.4 Convergence issues. 13.5 Modeling your problem. 13.6 Online vs. offline models. 13.7 If it works, patent it!
2,300 citations
TL;DR: In this paper, the existence and uniqueness of equilibrium points for concave n-person games is studied in a dynamic model for nonequilibrium situations, where the equilibrium points are chosen by the players.
Abstract: Existence and uniqueness of equilibrium points for concave n-person games - dynamic model for nonequilibrium situations
2,280 citations