Internet of Things (IoT) is an integral part of our daily lives and the security of these devices is paramount. However, IoT devices are often resource constrained, requiring implementations of ...efficient lightweight security strategy for such environments. In this paper, we propose a novel identity authenticated Key Agreement Scheme (KAS) for IoT environments based on Hyper Elliptic Curve Cryptography (HECC) and Chinese Remainder Theorem (CRT) built on four co-prime integers. The distributed CRT four co-prime based KAS permits multiple shared keys between devices which facilitates a subset construction with much greater device support and having full connectivity till depth four and overall better connectivity till greater depths than its two co-prime counterpart. We develop an efficient authentication mechanism based on HECC that has much smaller key sizes than most existing cryptosystems. The authentication part treats devices identities related to CRT four co-prime KAS as secret information during their exchange and thereby eliminates the well known selective device attack (SDA). We compute the standard resiliency measure,
fail
(
s
) with
s
=
1
for our authenticated CRT four co-prime KAS. Proposed scheme are secure against a variety of attacks, including reply attack, impersonation attack, user anonymity. A comparative study with existing schemes in terms of storage, network connectivity, communications overheads, scalability, resiliency and standard security parameters exhibits superiority of our schemes making them more apt during implementations in practical deployment zones.
This paper presents a novel federated reinforcement learning (Fed-RL) methodology to enhance the cyber resiliency of networked microgrids. We formulate a resilient reinforcement learning (RL) ...training setup which (a) generates episodic trajectories injecting adversarial actions at primary control reference signals of the grid forming (GFM) inverters and (b) trains the RL agents (or controllers) to alleviate the impact of the injected adversaries. To circumvent data-sharing issues and concerns for proprietary privacy in multi-party-owned networked grids, we bring in the aspects of federated machine learning and propose a novel Fed-RL algorithm to train the RL agents. To this end, the conventional horizontal Fed-RL approaches using decoupled independent environments fail to capture the coupled dynamics in a networked microgrid, which leads us to propose a multi-agent vertically federated variation of actor-critic algorithms, namely federated soft actor-critic (FedSAC) algorithm. We created a customized simulation setup encapsulating microgrid dynamics in the GridLAB-D/HELICS co-simulation platform compatible with the OpenAI Gym interface for training RL agents. Finally, the proposed methodology is validated with numerical examples of modified IEEE 123-bus benchmark test systems consisting of three coupled microgrids.
Children in Sub-Saharan Africa are living under chronic adversity due to poverty, serious health issues, physical and sexual abuse, and armed conflicts. These highly stressful conditions have ...deleterious effects on their mental health and socio-emotional adjustment. Since many children lack adequate access to mental health care, culturally adapted school-based resiliency programs could provide a resource to scaffold their development and promote their mental health. This study evaluated the efficacy of a universal school-based intervention in enhancing the resiliency of Tanzanian primary school children and cultivating prosocial behaviors. A total of 183 students from grades 4 to 6 were randomly assigned to either the 16-session “ERSAE-Stress-Prosocial (ESPS)” structured intervention or to a Social Study curriculum (SS) active control group. The original ESPS program was adapted by Tanzanians mental health professionals who modified the program based on local idioms of distress and indigenous practices. Students' resilience was evaluated before, after and 8 months following the intervention by assessing social difficulties, hyperactivity, somatization, level of anxiety, prosocial behaviors and school functioning as well as academic achievements and disciplinary problems. There was significant improvement on all outcome measures for the ESPS group compared to the control group post-intervention and at the 8-month follow up. The ESPS intervention was equally effective on most measures for students experiencing different adversity levels. The results indicate that a culturally adapted universal school-based intervention can be effective in enhancing Tanzanian students' resiliency and promoting prosocial behaviors. Should these results be replicated and found enduring, the modified ESPS could be a valuable mental health-promoting intervention in other low-income countries.
This paper discusses microgrid power supply resiliency in extreme events and the impact of power electronic interfaces, energy storage, lifelines, and the characteristics of distribution ...architectures. Resiliency is characterized based on metrics analogous to those of availability considering the presence of power electronic interfaces and energy storage. The effect of energy storage on microgrid resiliency is analyzed and resiliency improvement in the presence of diverse sources is discussed. Resiliency metrics, which are time dependent in nature, are derived under natural disasters conditions. Resiliency is calculated for microgrids containing photovoltaics with batteries, diesel generators, and fuel storage with discontinuous fuel supply. Hurricane conditions are considered to provide a practical context for the discussion. Microgrid resiliency formulas are derived for radial, ring, and ladder architectures. It is shown that the resiliency formula for radial architecture can be used as a building block to derive the formulas for the ring and ladder networks. Architecture resiliencies are compared in islanded and grid-tie modes. The results indicate that the effects of including energy storage and source diversity, such as combinations of renewable energy sources and diesel generators, can improve power supply resiliency when the microgrid is in island mode, which is the most likely operating mode during extreme events.
5G-Advanced and 6G networks will serve as critical infrastructure for society and will enable a new generation of immersive use cases, such as the metaverse, wherever people roam. Absolute time is an ...essential component to ensure critical use cases, synchronize media playout, and timestamp events to be used in machine learned contexts. Until now, timing on the go has mainly been acquired by satellite, e.g., Global Navigation Satellite System (GNSS), but a terrestrial timing solution using cellular networks is required to extend coverage to deep indoors and to offer resilient operation in GNSS-denied environments (e.g., due to GNSS signal interference, jamming and spoofing). In this paper, we detail the use cases for timing to be provisioned by 5G-Advanced and 6G networks. Then, we discuss the architectural enablers for timing as a service in current 5G and 5G-Advanced standard and timing resiliency enablers under discussion in the 3rd Generation Partnership Project (3GPP). Finally, we discuss the gaps and research challenges to be solved in 6G for future-proof timing solutions.
Hospital adaptation and resiliency, required during public health emergencies to optimize outcomes, are understudied especially in resource-limited settings.
What are the prepandemic and pandemic ...critical illness outcomes in a resource-limited setting and in the context of capacity strain?
We performed a retrospective cohort study among patients admitted to ICUs at two public hospitals in the KwaZulu-Natal Department of Health in South Africa preceding and during the COVID-19 pandemic (2017-2022). We used multivariate logistic regression to analyze the association between three patient cohorts (prepandemic non-COVID-19, pandemic non-COVID-19, and pandemic COVID-19) and ICU capacity strain and the primary outcome of ICU mortality.
Three thousand two hundred twenty-one patients were admitted to the ICU during the prepandemic period and 2,539 patients were admitted to the ICU during the pandemic period (n = 375 14.8% with COVID-19 and n = 2,164 85.2% without COVID-19). The prepandemic and pandemic non-COVID-19 cohorts were similar. Compared with the non-COVID-19 cohorts, the pandemic COVID-19 cohort showed older age, higher rates of chronic cardiovascular disease and diabetes, less extrapulmonary organ dysfunction, and longer ICU length of stay. Compared with the prepandemic non-COVID-19 cohort, the pandemic non-COVID-19 cohort showed similar odds of ICU mortality (OR, 1.06; 95% CI, 0.90-1.25; P = .50) whereas the pandemic COVID-19 cohort showed significantly increased odds of ICU mortality (OR, 3.91; 95% CI, 3.03-5.05 P < .0005). ICU occupancy was not associated with ICU mortality in either the COVID-19 cohort (OR, 1.05 per 10% change in ICU occupancy; 95% CI, 0.96-1.14; P = .27) or the pooled non-COVID-19 cohort (OR, 1.01 per 10% change in ICU occupancy; 95% CI, 0.98-1.03; P = .52).
Patients admitted to the ICU before and during the pandemic without COVID-19 were broadly similar in clinical characteristics and outcomes, suggesting critical care resiliency, whereas patients admitted to the ICU with COVID-19 showed important clinical differences and significantly higher mortality.
•Validation of analysis methods.•Comparison of tessellated and conventional shear walls.•Analyses of tessellated walls with varying edge tile patterns.•Damage definitions and quantification for ...aiding designers.•Parametric study involving parameters like concrete strength and reinforcement ratio.•A simplified analytical model to estimate the capacity of tessellated shear walls.
This paper studies the lateral behavior of a reinforced concrete tessellated structural-architectural (TeSA) shear wall system. TeSA walls are made of prefabricated repetitive tiles and have the ability to localize damage which occurs under extreme loading. A TeSA wall is intended for architectural interest, automated construction, reconfiguration, disassembly, and reuse. This study focuses on TeSA tiles that are topologically interlocking in two directions. Nonlinear finite element analysis is used to study the monotonic pushover behavior of TeSA walls with different edge tile configurations and a comparison is made thereof with a conventional reinforced concrete shear wall. The results indicate that the strength of TeSA walls is not significantly affected by the configuration of edge tiles. Damage progression in tiles and the number of damaged tiles that need to be replaced are also presented at different drift ratios. The study shows that reinforcement ratio substantially affects the wall lateral capacity. Finally, a simplified cross-sectional analysis procedure is proposed to provide a lower and upper bound estimate of the lateral capacity of TeSA walls.
Sustaining a stroke, regardless of its severity, is a life-changing and often traumatizing event that can lead to chronic depression, anxiety, and posttraumatic stress in both survivors and their ...family caregivers. Psychosocial interventions for emotional distress after stroke are limited, have emphasized psychoeducation rather than skills, treatment of chronic emotional distress rather than prevention, and have targeted either the patient or their caregiver without accounting for the context of their interpersonal relationship. Here we discuss “Recovering Together,” a novel program for dyads of patients with stroke and their family caregivers aimed at preventing chronic emotional distress by using cognitive behavioral principles to teach resiliency and interpersonal communication skills beginning during hospitalization in a neuroscience intensive care unit and continuing after discharge via telehealth. We illustrate the case of a pilot dyad enrolled in the Recovering Together program, to showcase how patients and caregivers can engage with and benefit from it. This dyad’s experience suggests that Recovering Together is credible, feasible, and useful. The potential dyadic benefit of this intervention lies not only in providing the opportunity to optimize recovery and prevent long-term emotional distress, but also in creating the space to come together as a pair and make meaning from critical illness.
•Resiliency training for stroke patients and caregivers is credible and feasible•Recovering Together pilot dyad endorsed high satisfaction and improved well-being•Dyadic approach provides a valued space for meaning making together after stroke
A criterion for tidal inlets to achieve sustainable stability was derived from theoretical considerations and validated with historical data. The criterion states, in part, that an inlet will achieve ...sustainable stability if its Keulegan’s repletion coefficient K exceeds 1.86. Based on the fundamental hydraulics of tidal inlets that holds regardless of timescale, the criterion relates the stability of an inlet to a suite of throat parameters explicitly. The criterion distinguishes between general stability and sustainable stability, thereby permitting a statement on the inlet resiliency in the context of climate change. The criterion was evaluated for 44 global inlets with known stability conditions at the time of data. The results were found to validate the criterion. The criterion suggests that inlet stability exists across a semi-infinite space of K rather than at (or around) a certain throat area Ac as implied by the O’Brien-Jarrett criteria and expounded by Escoffier. For a stable inlet, the effective tidal prism is in a dynamic equilibrium with a suite of throat parameters rather than with the throat area Ac alone. The tidal prism as normalized will remain unchanged as long as the sustainable criterion is met even as the throat parameters modulate individually or collectively in a changing physical environment on any timescales. Since all of the throat parameters involved are relatively easy to obtain for a given inlet, the criterion can be conveniently applied in coastal planning and conceptual design where initial scoping, problem identification, and evaluation of frequently numerous alternatives may require a simpler, less costly tool than numerical modeling.
The First Responder ECHO (Extension for Community Outcomes) program was established in 2019 to provide education for first responders on self-care techniques and resiliency while establishing a ...community of practice to alleviate the enormous stress due to trauma and substance misuse in the community. When the SARS-CoV-2 (COVID-19) pandemic hit the United States (US) in March 2020, a tremendous strain was placed on first responders and healthcare workers, resulting in a program expansion to include stress mitigation strategies. From 31 March 2020, through 31 December 2020, 1530 unique first responders and frontline clinicians participated in the newly expanded First Responder Resiliency (FRR) ECHO. The robust curriculum included: psychological first aid, critical incident debriefing, moral distress, crisis management strategies, and self-care skills. Survey and focus group results demonstrated that, while overall stress levels did not decline, participants felt more confident using psychological first aid, managing and recognizing colleagues who needed mental health assistance, and taking time for self-care. Although first responders still face a higher level of stress as a result of their occupation, this FRR ECHO program improves stress management skills while providing weekly learning-listening sessions, social support, and a community of practice for all first responders.
PDF
