15,012 research outputs found

    Spatial optimization for land use allocation: accounting for sustainability concerns

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    Land-use allocation has long been an important area of research in regional science. Land-use patterns are fundamental to the functions of the biosphere, creating interactions that have substantial impacts on the environment. The spatial arrangement of land uses therefore has implications for activity and travel within a region. Balancing development, economic growth, social interaction, and the protection of the natural environment is at the heart of long-term sustainability. Since land-use patterns are spatially explicit in nature, planning and management necessarily must integrate geographical information system and spatial optimization in meaningful ways if efficiency goals and objectives are to be achieved. This article reviews spatial optimization approaches that have been relied upon to support land-use planning. Characteristics of sustainable land use, particularly compactness, contiguity, and compatibility, are discussed and how spatial optimization techniques have addressed these characteristics are detailed. In particular, objectives and constraints in spatial optimization approaches are examined

    IR theory, historical materialism, and the false promise of international historical sociology

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    The three-decades old call for an inter-disciplinary rapprochement between IR Theory and Historical Sociology, starting in the context of the post-positivist debate in the 1980s, has generated a proliferating repertory of contending paradigms within the field of IR, including Neo-Weberian, Post-Structuralist, and Constructivist approaches. Within the Marxist literature, this project comprises an equally rich and diverse set of theoretical traditions, including World-Systems Theory, Neo-Gramscian IR/IPE, the Amsterdam School, Political Marxism, Neo-Leninism, and Postcolonial Theory. More recently, a “third wave” of approaches has been announced from within the field of IR, suggesting to move the dialogue from inter-disciplinarity towards an integrated super-discipline of International Historical Sociology (IHS). This proposition has been most persistently advanced by advocates of the theory of Uneven and Combined Development (UCD), claiming to constitute a universal, unitary and sociological theory of IR. This article charts the intellectual trajectory of this ongoing IR/HS dialogue. It moves from a critique of Neo-Weberianism to a critique of UCD against the background of the original promise of the turn in IR to Historical Sociology: the supersession of the prevailing rationalism, structuralism, and positivism in extant mainstream IR approaches through the mobilization of alternative and non-positivistic traditions in the social sciences. This critique will be performed by setting UCD in dialogue with Political Marxism. By anchoring both approaches at opposite ends on the spectrum of Marxist conceptions of social science – respectively the scientistic and the historicist - the argument is that UCD reneges on the promise of Historical Sociology for IR by re-aligning, first by default and now by design, with the meta-theoretical premises of Neo-Realism. This is most visibly expressed in the articulation of a deductive-nomological covering law, leading towards acute conceptual and ontological anachronisms, premised on the radical de-historicisation of the fields of ontology, conceptuality and disciplinarity. This includes the semantic neutering and hyper-abstract re-articulation of the very category, which in IR’s self-perception lends legitimacy to its claim of disciplinary distinctiveness: the international. The article concludes by suggesting that an understanding of Marxism as a historicist social science subverts all calls for the construction of grand theories and, a fortiori, a unitary super-discipline of IHS, premised on a set of universal, space-time indifferent, and abstract categories that hold across the spectrum of world history. In contrast, recovering the historicist credentials of Marxism demands a constant temporalisation and specification of the fields of ontology, agency, conceptuality and disciplinarity. The objective is to lay the foundations for a historicist social science of geopolitics

    Scientific Methodology: A View from Early String Theory

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    This paper addresses the question as to whether the methodology followed in building and assessing string theory can be considered scientific in the same sense, say, that the methodology followed in building and assessing the Standard Model of particle physics is scientific, by focussing on the "founding" period of the theory. More precisely, its aim is to argue for a positive answer to the above question (there is no real change of scientific status in the way of proceeding and reasoning in fundamental physical research) in the light of a historical analysis of the early developments of the string theoretical framework.Comment: Contribution to the volume "Epistemology of Fundamental Physics: Why Trust a Theory?", eds. R. Dawid, R. Dardashti, and K. Thebault, Cambridge University Pres

    Green supply chain quantitative models for sustainable inventory management: A review

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    [EN] This paper provides a systematic and up-to-date review and classification of 91 studies on quantitative methods of green supply chains for sustainable inventory management. It particularly identifies the main study areas, findings and quantitative models by setting a point for future research opportunities in sustainable inventory management. It seeks to review the quantitative methods that can better contribute to deal with the environmental impact challenge. More specifically, it focuses on different supply chain designs (green supply chain, sustainable supply chain, reverse logistics, closed-loop supply chain) in a broader application context. It also identifies the most important variables and parameters in inventory modelling from a sustainable perspective. The paper also includes a comparative analysis of the different mathematical programming, simulation and statistical models, and their solution approach, with exact methods, simulation, heuristic or meta-heuristic solution algorithms, the last of which indicate the increasing attention paid by researchers in recent years. The main findings recognise mixed integer linear programming models supported by heuristic and metaheuristic algorithms as the most widely used modelling approach. Minimisation of costs and greenhouse gas emissions are the main objectives of the reviewed approaches, while social aspects are hardly addressed. The main contemplated inventory management parameters are holding costs, quantity to order, safety stock and backorders. Demand is the most frequently shared information. Finally, tactical decisions, as opposed to strategical and operational decisions, are the main ones.The research leading to these results received funding from the Grant RTI2018-101344-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe". It was also funded by the National Agency for Research and Development (ANID) / Scholarship Program/Doctorado Becas en el Extranjero/2020 72210174.Becerra, P.; Mula, J.; Sanchis, R. (2021). Green supply chain quantitative models for sustainable inventory management: A review. Journal of Cleaner Production. 328:1-16. https://doi.org/10.1016/j.jclepro.2021.129544S11632

    (WP 2012-01) Samuels on Methodological Pluralism in Economics

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    Warren Samuels was an influential proponent of methodological pluralism in economics. This short paper discusses his understanding of methodological pluralism, and argues that it is based on three distinct components: (1) his critique of the idea that theories have epistemic foundations and his \u27matrix approach to meaningfulness,\u27 (2) his belief that the absence of meta-principles for science combined with our human psychology create an existential dilemma for theorists and policy-makers, and (3) his understanding of relativism, social constructivism, and \u27limited but affirmative\u27 defense of nihilism against the charge of skepticism. The paper closes with a brief discussion of what Samuels\u27 methodological pluralism might tell us about historiography and the history of economics

    An anytime tree search algorithm for two-dimensional two- and three-staged guillotine packing problems

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    [libralesso_anytime_2020] proposed an anytime tree search algorithm for the 2018 ROADEF/EURO challenge glass cutting problem (https://www.roadef.org/challenge/2018/en/index.php). The resulting program was ranked first among 64 participants. In this article, we generalize it and show that it is not only effective for the specific problem it was originally designed for, but is also very competitive and even returns state-of-the-art solutions on a large variety of Cutting and Packing problems from the literature. We adapted the algorithm for two-dimensional Bin Packing, Multiple Knapsack, and Strip Packing Problems, with two- or three-staged exact or non-exact guillotine cuts, the orientation of the first cut being imposed or not, and with or without item rotation. The combination of efficiency, ability to provide good solutions fast, simplicity and versatility makes it particularly suited for industrial applications, which require quickly developing algorithms implementing several business-specific constraints. The algorithm is implemented in a new software package called PackingSolver

    The Knowledge Level in Cognitive Architectures: Current Limitations and Possible Developments

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    In this paper we identify and characterize an analysis of two problematic aspects affecting the representational level of cognitive architectures (CAs), namely: the limited size and the homogeneous typology of the encoded and processed knowledge. We argue that such aspects may constitute not only a technological problem that, in our opinion, should be addressed in order to build articial agents able to exhibit intelligent behaviours in general scenarios, but also an epistemological one, since they limit the plausibility of the comparison of the CAs' knowledge representation and processing mechanisms with those executed by humans in their everyday activities. In the final part of the paper further directions of research will be explored, trying to address current limitations and future challenges
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