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Mapping Mining’s Temporal Disruptions: Understanding Peruvian Women’s Experiences of Place-attachment in Changing Landscapes
Get PDFThe importance of mining temporalities and gendered impacts of mining activity are receiving increasing academic attention. This article contributes to these debates by addressing the impacts of large-scale mining activity on women’s sense of place-attachment and landscape, focusing on Cajamarca, Peru, home to the Yanacocha mine since 1993. Using women’s hand-drawn maps representing ‘sites of change’, the article critically examines the various ways in which women communicate mining as deeply affecting their everyday lives in gendered ways. This mapping method tapped into emotional connections to place and local landscapes, and by incorporating stories and maps of both women opposing and supporting further mining expansion in the region, the article goes on to show that both groups share an understanding of the Yanacocha mine as a disruption of time and place
Evasion Generative Adversarial Network for Low Data Regimes
Get PDFA myriad of recent literary works has leveraged generative adversarial networks (GANs) to generate unseen evasion samples. The purpose is to annex the generated data with the original train set for adversarial training to improve the detection performance of machine learning (ML) classifiers. The quality of generated adversarial samples relies on the adequacy of training data samples. However, in low data regimes like medical diagnostic imaging and cybersecurity, the anomaly samples are scarce in number. This paper proposes a novel GAN design called Evasion Generative Adversarial Network (EVAGAN) that is more suitable for low data regime problems that use oversampling for detection improvement of ML classifiers. EVAGAN not only can generate evasion samples, but its discriminator can act as an evasion-aware classifier. We have considered Auxiliary Classifier GAN (ACGAN) as a benchmark to evaluate the performance of EVAGAN on cybersecurity (ISCX-2014, CIC-2017 and CIC2018) botnet and computer vision (MNIST) datasets. We demonstrate that EVAGAN outperforms ACGAN for unbalanced datasets with respect to detection performance, training stability and time complexity. EVAGAN’s generator quickly learns to generate the low sample class and hardens its discriminator simultaneously. In contrast to ML classifiers that require security hardening after being adversarially trained by GAN-generated data, EVAGAN renders it needless. The experimental analysis proves that EVAGAN is an efficient evasion hardened model for low data regimes for the selected cybersecurity and computer vision datasets. Code will be available at HTTPS://www.github.com/rhr407/EVAGAN
Hierarchical User-Driven Trajectory Planning and Charging Scheduling of Autonomous Electric Vehicles
Get PDFAutonomous electric vehicles (A-EVs), regarded as one of the innovations to accelerate transportation electrification, have sparked a flurry of interest in trajectory planning and charging scheduling. In this regard, this work employs mobile edge computing (MEC) to design a decentralized hierarchical algorithm for finding an optimal path to the nearby A-EV parking lots (PL), selecting the best PL, and executing an optimal charging scheduling. The proposed model makes use of unmanned aerial vehicles (UAVs) to assist edge servers in trajectory planning by surveying road traffic flow in real-time. Further, the target PLs are selected using a user-driven multi-objective problem to minimize the cost and waiting time of A-EVs. To tackle the complexity of the optimization problem, a greedy-based algorithm has been developed. Finally, charging/discharging power is scheduled using a local optimizer based on the PLs’ real-time loads which minimizes the deviation of the charging/discharging power from the average load. The obtained results show that the proposed model can handle charging/discharging requests of on-move A-EVs and bring fiscal and non-fiscal benefits for A-EVs and the power grid, respectively. Moreover, it observed that user satisfaction in terms of traveling time and traveling distance are increased by using the edge-UAV model
The politics of transnational student mobility: youth, education and activism in Ghana, 1957–1966
Get PDFThis article examines the political agendas, practical challenges and personal aspirations that informed different forms of transnational student mobility in the 1950s and 1960s. It does so by focusing on a variety of initiatives that involved Ghana during the period of Kwame Nkrumah's rule (1957–1966). The article considers schemes that enabled Ghanaian students to attend universities in the United States and the communist bloc, but it also traces the operation of 'Freedom Fighters' scholarships that brought young people from different parts of Africa to Ghana. Moreover, it shows how involvement in student organisations connected Ghanaian student leaders to an international community of activists. Notwithstanding the importance of Cold War dynamics and Pan-African ambitions, the article argues that these multidirectional mobilities can be understood within the broader framework of internationalism. In examining this phenomenon from different perspectives, the piece traces the tensions between official designs on the one side and students’ experiences, discord and contention on the other
Two birds, one stone: How altruism can facilitate both individual creativity and prosocial behavior in two different team contexts
Get PDFObjective: This article aims to examine how individual disposition is influenced by group structures and how this in turn enhances team members’ creative and prosocial behaviors. Building on a person-in-situation theory, we argue that altruism is a communal personality leading to the dual outcome of creativity and prosocial behavior, and altruism can best facilitate the dual outcomes of creativity and prosocial behavior when team standardization is low and when team participation is high. Method: Based on data from 346 employees in 86 teams, the results from multilevel modeling largely supported our hypotheses. Results: Altruism is associated with both individual creativity and prosocial behavior when team participation is high. Altruism is associated with individual prosocial behavior when team standardization is low. Conclusions: Our study shows that to foster creativity and prosociality, teams need not only to pay attention to team members’ altruistic dispositional tendency but also to build a participative team environment and reduce team standardization to enable such dispositional tendency to be expressed. In doing so, our study offers a new alignment of prescriptions to foster prosociality and creativity. Being altruistic is an antecedent of prosociality, but it is also a powerful driver of individual creativity in participative teams
One-Week L-Arginine Supplementation Had No Effect on 200m Freestyle Swimming Time Trial in Moderately-Trained Male Swimmers
Get PDFResearch on the effect of L-arginine supplementation on exercise performance is still inconsistent and its influence on single-bout swimming performance has not been investigated. Therefore, the aim of this study was to assess if one-week L-arginine supplementation would enhance 200-m freestyle swimming performance in trained/developmental (regularly training ∼3 times per week with a purpose to compete) male swimmers. In a randomized, cross-over, double-blind design, 8 trained/developmental male swimmers (age 25 ± 5 years; mean ± SD) completed 200-m freestyle swimming time-trial on 3 separate occasions: a control trial; and after 2 separate 7-d supplementation periods, with a daily dose of either 8 g/d of L-arginine or placebo trials. Blood lactate concentration was measured immediately post time-trial swimming. Completion time of the 200-m freestyle swimming time-trial did not differ significantly (F = 4.55; P = 0.060; ŋp2 = 0.394) between control (149.40 ± 9.88 s), L-arginine (146.02 ± 10.34 s) and placebo trials (147.58 ± 10.86 s). There was no statistically significant difference in post time-trial swimming blood lactate concentration between trials (control: 11.2 ± 2.7; L-arginine: 13.1 ± 1.8; Placebo: 12.2 ± 2.7, F = 3.52; P = 0.058; ŋp2 = 0.335). One-week of supplementation with 8 g/d of L-arginine, had no ergogenic effect on middle-distance (200-m), freestyle swimming performance in trained/developmental male swimmers
The trade-off between inflation and unemployment in an ‘MMT world’: an open-economy perspective
Get PDFThis paper is focused on modern monetary theory’s (MMT) treatment of inflation from an open-economy perspective. It analyses how the inflation process is explained within the MMT framework and provides empirical evidence in support of this vision. However, it also makes use of a stock–flow consistent open-economy model to underline some limits of the theory when it is applied in the context of a non-US (relatively) open economy with a flexible exchange-rate regime. The model challenges the contention made by MMT-ers that measures such as the job guarantee programme can achieve full employment without facing an inflation–unemployment trade-off
Delayed circadian rhythms in older Africans living with human immunodeficiency virus (HIV)
Get PDFThe increasing number of people living with human immunodeficiency virus, HIV, (PLWH) have an elevated incidence of risk for noncommunicable comorbidities, the aetiology of which remains incompletely understood. While sleep disturbances are often reported in PLWH, it is unknown to what extent they relate to changes in the circadian and/or sleep homeostatic processes. We studied the relationship between sleep characteristics, circadian phase, and HIV status in older adults from the HAALSI (Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa) subsample of the Agincourt Health and Demographic Surveillance System in South Africa (n = 187, 36 human immunodeficiency virus positive [HIV+], age: 66.7 ± 11.5 years, range 45—93 years), where HIV prevalence is high and (in contrast to the global north) does not associate significantly with potentially confounding behavioural differences. In participants with valid actigraphy data (n = 172), regression analyses adjusted for age and sex indicated that HIV+ participants had slightly later sleep onset (β = .16, p = .039), earlier sleep offset times (β = −.16, p = .049) and shorter total sleep times (β = −.20, p = .009) compared to the HIV negative (HIV−) participants. In a subset of participants (n = 51, 11 HIV+), we observed a later dim light melatonin onset (DLMO) in HIV+ (21:16 ± 01:47) than in HIV− (20:06 ± 00:58) participants (p = .006). This substantial difference remained when adjusted for age and sex (β = 1.21; p = .006). In 36 participants (6 HIV+) with DLMO and actigraphy data, median phase angle of entrainment was −6 min in the HIV+ group and +1 h 25 min in the HIV− group. DLMO time correlated with sleep offset (ρ = 0.47, p = .005) but not sleep onset (ρ = −0.086, p = .623). Collectively, our data suggest that the sleep phase occurred earlier than what would be biologically optimal among the HIV+ participants. This is the first report of a mistimed circadian phase in PLWH, which has important potential implications for their health and well-being, especially given the well-established relationships between circadian asynchrony and sleep deprivation with poorer health outcomes
Risk-embedded scheduling of a CCHP integrated with electric vehicle parking lot in a residential energy hub considering flexible thermal and electrical loads
Get PDFClimate change has detrimental impacts on the environment and sustainability, leading to employing alternative energy systems such as combined cooling, heat and power (CCHP). The concept of integrated energy systems (IES) allows the coordination of several components, such as electric vehicles (EV), to serve various demands simultaneously. This paper focuses on coordinating the CCHP and electric vehicle parking lot (EVPL) integrated with photovoltaic (PV) technology as renewable energy (RE). The residential energy hub (REH) is modeled to integrate these components to meet the demands and minimize REH’s operating costs and carbon emissions. EVPL functions as dynamic electrical storage besides serving EVs. Stochastic programming is used to model RE, EV, loads, and electricity price uncertainties. Demand response (DR) is applied for shiftable electrical loads. The thermodynamic model of heating and cooling loads is developed with flexibility as integrated demand response (IDR) based on the building’s desired temperature. The emission cost model with penalty factors enforces REH to use less-pollutant energy sources. Subsequently, a risk-aversion strategy, namely downside risk constraint (DRC), is implemented to diminish the associated risk as the consequence of uncertainties for the decision-maker. Different constraint level is applied to provide various conservative decision-making strategies for the operator. Summer and winter scenarios with and without DR and flexible thermal loads were used to evaluate the model’s accuracy. The scheduling problem is solved in IEEE 33-bus test system. The results reveal that the DR could reduce the operation cost by 5% in summer and 8% in winter. Moreover, zero risk for summer and winter is gained at the cost of 10.4% and 3.1% increment in operating costs
Sustainability considerations in remediation, retrofit, and seismic upgrading of historic masonry structures
Get PDFThis paper addresses the problem of sustainability in remediation, retrofit, and seismic upgrading of historic masonry structures. Different rehabilitation techniques and some successful applications throughout the Balkans and Italy are described, with particular emphasis to the shear reinforcement of wall panels. The selected techniques aim at improving the seismic performance, preserving the structures for future generations, having the least impact in altering the architectural and heritage values, as well as being sustainable, in terms of reduced carbon dioxide emissions, reversibility, and low energy consumption. The use of cross-laminated timber (CLT), natural fibers, and fiber-reinforced Polymers (FRP) jacketing with natural lime coatings are discussed. The paper concludes by summarizing key successes of the proposed rehabilitation solutions in conservation engineering and suggests areas in which these could be used with great advantage