886 research outputs found

    Contributions of a feminist perspective to the analysis of farm viability: the livelihoods reproduction framework

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    [EN] The agrarian question dealing with peasants' reproduction in adverse global conditions is a topic of deep debate closely linked to farm viability. Approaches that define viability in monetary terms cannot explain peasants' way of farming. Holistic approaches can better analyse this question but existing frameworks leave aside aspects of reproduction. Here, we revise sustainable livelihoods and resilience frameworks through a feminist lens and propose livelihoods reproduction to address some blind spots. We do so through a literature review and a case study of olive oil farms in Spain. Our analysis highlights the importance of household labour distribution for farm viability.This work was supported by Ministerio de Ciencia e Innovacion: [Grant Number CSO2016-78827-R]; the Spanish Ministry of Science, Innovation and Universities (Ministerio de Ciencia, Innovacion y Universidades): [Grant Number PCI2018-093179]; and ARIMNet2 (ERA-NET no. 618127).Manuel, J.; Rivera-Ferre, MG.; López-I-Gelats, F. (2023). Contributions of a feminist perspective to the analysis of farm viability: the livelihoods reproduction framework. The Journal of Peasant Studies. 51(1):185-211. https://doi.org/10.1080/03066150.2023.221050018521151

    Regular sparse array direction of arrival estimation in one dimension

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    Traditionally regularly spaced antenna arrays follow the spatial Nyquist criterion to guarantee an unambiguous analysis. We present a novel technique that makes use of two sparse non-Nyquist regularly spaced antenna arrays, where one of the arrays is just a shifted version of the other. The method offers several advantages over the use of traditional dense Nyquist spaced arrays, while maintaining a comparable algorithmic complexity for the analysis. Among the advantages we mention: an improved resolution for the same number of receivers and reduced mutual coupling effects between the receivers, both due to the increased separation between the antennas. Because of a shared structured linear system of equations between the two arrays, as a consequence of the shift between the two, the analysis of both is automatically paired, thereby avoiding a computationally expensive matching step as is required in the use of so-called co-prime arrays. In addition, an easy validation step allows to automatically detect the precise number of incoming signals, which is usually considered a difficult issue. At the same time, the validation step improves the accuracy of the retrieved results and eliminates unreliable results in the case of noisy data. The performance of the proposed method is illustrated with respect to the influence of noise as well to the effect of mutual coupling

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    Re-framing the climate change debate in the livestock sector: mitigation and adaptation options

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    Livestock play a key role in the climate change debate. As with crop-based agriculture, the sector is both a net greenhouse gas emitter and vulnerable to climate change. At the same time, it is an essential food source for millions of people worldwide, with other functions apart from food security such as savings and insurance. By comparison with crop-based agriculture, the interactions of livestock and climate change have been much less studied. The debate around livestock is confusing due to the coexistence of multiple livestock farming systems with differing functions for humans, greenhouse gas (GHG) emission profiles and different characteristics and boundary issues in their measurement, which are often pooled together. Consequently, the diversity of livestock farming systems and their functions to human systems are poorly represented and the role of the livestock sector in the climate change debate has not been adequately addressed. In this article, building upon the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC 5AR) findings, we review recent literature on livestock and climate change so as better to include this diversity in the adaptation and mitigation debate around livestock systems. For comparative purposes we use the same categories of managerial, technical, behavioral and policy-related action to organize both mitigation and adaptation options. We conclude that different livestock systems provide different functions to different human systems and require different strategies, so they cannot readily be pooled together. We also observe that, for the different livestock systems, several win-win strategies exist that effectively tackle both mitigation and adaptation options as well as food security

    Design of a linear time-varying Model Predictive Control energy regulator for grid-tied VSCs

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    This paper presents an energy regulator based on a Model Predictive Control (MPC) algorithm for a Voltage Source Converter (VSC). The MPC is formulated to optimise the converter performance according to the weights defined in an objective function that trades off additional features, such as current harmonic distortion, reactive power tracking and DC bus voltage oscillation. Differently from most approaches found in the research literature, the MPC proposed here considers the coupling dynamics between the AC and DC sides of the VSC. This study is focused on the example case of a single-phase VSC, which presents a nonlinear relationship between its AC and DC sides and a sustained double-line frequency power disturbance in its DC bus. To reduce the burden of the MPC, the controller is formulated to benefit from the slow energy dynamics of the system. Thus, the cascaded structure typically used in the control of VSCs is kept and the MPC is set as an energy regulator at a reduced sampling frequency while the current control relies on a fast inner controller. The computational burden of the algorithm is further reduced by using a linear time-varying approximation. The controller is presented in detail and experimental validation showing the performance of the algorithm is provided
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