133 research outputs found

    Towards Studying Collective Dynamics of Electricity Sharing Systems

    Get PDF
    AbstractIn this paper, we propose an agent-based model for investigating collective dynamics in community-based electricity sharing systems. In our simulations, we assume the absence of electricity grids and telecommunication infrastructure–a situation which might be induced by a big natural disaster or a large-scale black-out. Under such circumstances, electricity sharing systems based on decentralized, small-scale renewables could help meeting basic electricity demand. Since real-world tests are hardly possible for such a scenario, we analyze possible collective reactions via means of social simulation

    Principles and criteria for assessing urban energy resilience: A literature review

    Get PDF
    AbstractBetween 60% and 80% of global energy is consumed in urban areas and given the projected increase in world׳s urban population, this share is expected to further increase in the future. Continuity of energy supply in cities is affected by climate change and a growing array of other threats such as cyber attacks, terrorism, technical deficiencies, and market volatility. Determined efforts, acknowledging the interactions and interlinkages between energy and other sectors, are needed to avoid adverse consequences of disruption in energy supply. Resilience thinking is an approach to management of socio-ecological systems that aims to develop an integrated framework for bringing together the (often) fragmented, diverse research on disaster risk management. The literature on urban resilience is immense and still growing. This paper reviews literature related to energy resilience to develop a conceptual framework for assessing urban energy resilience, identify planning and design criteria that can be used for assessing urban energy resilience, and examine the relationship of these criteria with the underlying components of the conceptual framework. In the conceptual framework, it is proposed that in order to be resilient, urban energy system needs to be capable of “planning and preparing for”, “absorbing”, “recovering from”, and “adapting” to any adverse events that may happen in the future. Integrating these four abilities into the system would enable it to continuously address “availability”, “accessibility”, “affordability”, and “acceptability” as the four sustainability-related dimensions of energy. The paper explains different resilience principles associated with these abilities and sustainability dimensions. Also, different planning and design criteria were extracted from the literature and categorized into five themes: infrastructure; resources; land use, urban geometry and morphology; governance; and socio-demographic aspects and human behavior. Examination of the relationship of these criteria with the underlying components of the conceptual framework highlighted the complexity and multi-faceted nature of energy resilience. Exploration of the relevance of the identified criteria to climate change mitigation and adaptation revealed that most of the identified criteria can provide both mitigation and adaptation benefits

    Systematizing and upscaling urban climate change mitigation

    Get PDF
    The question of what cities can contribute to mitigation and adapting to climate change is gaining traction among researchers and policy makers alike. However, while the field is rich with case studies, methods that provide rich data across municipalities and potentially at global scale remain underdeveloped, and comparative insights remain scarce. Here we summarize contributions to the focus issue on 'Systematizing and Upscaling Urban Climate Solutions', also drawing from presentations given at an accompanying conference in 2018. We highlight four core areas for systematizing and upscaling urban climate mitigation solutions. First, with more and better (big) data and associated machine learning methods, there is increasing potential to compare types of cities and leverage collective understanding. Second, while urban climate assessments have mostly emphasized urban planning, demand-side action as related to both behavioral change and modified social practices relevant to urban space deserve more academic attention and integration across a diverse set of social sciences. Third, climate mitigation would be intangible as a single objective at the urban scale, and measures and solutions that coordinate mitigation coherently with adaptation and broader sustainable development goals require explicit conceptualization and systematization. Forth, all insights should come together to develop governance frameworks that translate scientific exercises into concrete, realistic and organized action plans on the ground, for all cities

    Involvement of Spinal Angiotensin II System in Streptozotocin-Induced Diabetic Neuropathic Pain in Mice

    Get PDF
    ABSTRACT Renin-angiotensin system (RAS) activity increases under hyperglycemic states, and is thought to be involved in diabetic complications. We previously demonstrated that angiotensin (Ang) II, a main bioactive component of the RAS, might act as a neurotransmitter and/or neuromodulator in the transmission of nociceptive information in the spinal cord. Here, we examined whether the spinal Ang II system is responsible for diabetic neuropathic pain induced by streptozotocin (STZ). Tactile allodynia was observed concurrently with an increase in blood glucose levels the day after mice received STZ (200 mg/kg, i.v.) injections. Tactile allodynia on day 14 was dose-dependently inhibited by intrathecal administration of losartan, an Ang II type 1 (AT1) receptor antagonist, but not by PD123319, an AT2 receptor antagonist. In the lumbar dorsal spinal cord, the expression of Ang II, Ang converting enzyme (ACE), and phosphop38 mitogen-activated protein kinase (MAPK) were all significantly increased on day 14 after STZ injection compared with vehicletreated controls, whereas no differences were observed among AT1 receptors or angiotensinogen levels. Moreover, the increase in phospho-p38 MAPK was significantly inhibited by intrathecal administration of losartan. These results indicate that the expression of spinal ACE increased in STZ-induced diabetic mice, which in turn led to an increase in Ang II levels and tactile allodynia. This increase in spinal Ang II was accompanied by the phosphorylation of p38 MAPK, which was shown to be mediated by AT1 receptors

    Extended Averaged Learning Subspace Method for Hyperspectral Data Classification

    Get PDF
    Averaged learning subspace methods (ALSM) have the advantage of being easily implemented and appear to outperform in classification problems of hyperspectral images. However, there remain some open and challenging problems, which if addressed, could further improve their performance in terms of classification accuracy. We carried out experiments mainly by using two kinds of improved subspace methods (namely, dynamic and fixed subspace methods), in conjunction with the [0,1] and [-1,+1] normalization methods. We used different performance indicators to support our experimental studies: classification accuracy, computation time, and the stability of the parameter settings. Results are presented for the AVIRIS Indian Pines data set. Experimental analysis showed that the fixed subspace method combined with the [0,1] normalization method yielded higher classification accuracy than other subspace methods. Moreover, ALSMs are easily applied: only two parameters need to be set, and they can be applied directly to hyperspectral data. In addition, they can completely identify training samples in a finite number of iterations
    corecore