Hospital service robots must coordinate time-sensitive and heterogeneous tasks while maintaining reliable awareness of nearby robots in structured, human-populated clinical spaces where GPS, wireless communication, and global localization can be degraded. Existing studies typically address perception, task allocation, or path optimization as separate components, which limits their ability to support closed-loop multi-robot coordination under communication-constrained hospital conditions. This paper presents a graph-driven multi-robot coordination framework with situational awareness for hospital service robotics. The framework couples three coordination modules on a shared MAKLINK Graph Theory (MGT) representation of the hospital layout. First, a lightweight CNN-LiDAR module performs point-wise binary segmentation of 2D LiDAR scans to detect peer robots and maintain local fleet awareness during GPS or network outages. Second, the detected peer positions and confidence scores are passed to a priority-weighted Self-Organizing Map (SOM), which allocates asynchronous service tasks according to task urgency, deadline, risk, proximity, and workload balance, with Lazy Theta* generating feasible any-angle initial routes on the MGT graph inside the allocation loop to link assignment decisions to executable navigation. Finally, an improved Moss Growth Optimization (iMGO) module refines the initial routes by optimizing waypoint locations on a compact line-of-sight-preserving MAKLINK domain. Simulation and comparison studies validate the perception, allocation, path-refinement, and integrated pipeline components. The CNN-LiDAR subsystem sustains reliable peer-robot detection during GPS and communication outages, with near-perfect accuracy at the close range most critical for collision avoidance. The priority-weighted SOM improves task-completion behavior and workload balance compared with clustering and non-clustering genetic algorithm baselines. The iMGO module produces shorter and smoother collision-free paths with faster convergence than competing optimizers. The integrated multi-robot simulations further show reduced mission time and travel distance relative to random allocation, supporting the proposed framework as a scalable and safety-aware coordination architecture for hospital service robotics.
Modernizing the electric power grid through advanced communications and intelligent devices has improved efficiency and reliability, but it has also expanded the cyberattack surface. One of the most consequential integrity threats is False Data Injection Attacks (FDIAs), which can compromise the measurements and data streams that underpin monitoring, protection, and control functions. This paper surveys FDIA research in smart grids and organizes attack targets into five domains: steady-state control; transient and auxiliary control; substation control; energy and load control; and AI-based systems. We review how attackers construct stealthy and data-driven FDIAs, summarize their physical and economic impacts, and discuss why many existing detection mechanisms remain vulnerable. Finally, we highlight open challenges and outline research directions toward resilient, attack-aware grid architectures.
Africa is increasingly being exposed to the negative impacts of climate and environmental change, while having less capacity to respond compared to other continents. The vulnerability partially results from unprecedented demographic growth, urbanization, and industrialization. However, the continent has still largely been underserved by the broader Earth system science (ESS) community, as evidenced by the limited amount of ESS data and research that cover Africa compared to other areas of the world. Here, we present the recent University Corporation for Atmospheric Research (UCAR) Africa Initiative that aims to enhance environmental sustainability in Africa by fostering international collaborative research partnerships coled by African scientists. Specifically, we outline urgent challenges and opportunities identified through an international workshop in six areas of ESS, namely, 1) air quality and health, 2) weather, 3) climate, 4) land and water, 5) social science perspectives, and 6) developing equitable collaboration and sustainable infrastructure. We highlight examples of successful partnerships and conclude with recommendations to advance collaborative, actionable ESS research that addresses Africa's critical environmental challenges.
Branched polymers have attracted significant interest due to their unique structural features such as large molecular size, high surface area, accessible reactive groups, and favorable thermal properties. Hyperbranched polymers are particularly appealing as they can be synthesized in a single step with high yields and minimal byproducts. In this work, we have synthesized a series of degradable hyperbranched poly(silyl ether)s (HBPSEs) by a manganese-catalyzed dehydrogenative cross-coupling of an A2 + B3 system consisting of a diol and phenylsilane. The polymers have been characterized by various spectroscopic techniques, including 2D NMR techniques such as HSQC, HMBC, and HOESY, which allows us to assign branching and linear units and determine the degree of branching (DB) of these hyperbranched polymers. The analysis reveals that a certain level of control over the branching of the polymers can be achieved with a DB of up to 0.9 without gelation. Thermal degradation was evaluated by evolved gas analysis mass spectrometry (EGA-MS), which provides insight into the degradation process and the degradation products.
This study examines the relationship between corporate governance mechanisms and financial stability in non-financial firms listed on African stock markets, with a specific focus on the moderating role of religious diversity. A quantitative research design was employed, using data from 281 non-financial listed firms across 23 African countries over the 2012-2022 period. A two-step system dynamic generalized method of moments (GMM) was implemented to analyze the data. Corporate governance mechanisms, including board independence, board size, board effectiveness, and chairman duality, positively influence financial stability. Furthermore, religious diversity moderates these relationships, amplifying the positive effects of governance mechanisms on financial stability. Managers should prioritize religious diversity in board composition to strengthen governance and financial stability. Inclusive recruitment practices, cultural competency training, and policies that support diverse representation can enhance board effectiveness. This study extends the understanding of corporate governance by highlighting the significant role of religious diversity. It also provides new insights into how religious diversity can influence the effectiveness of governance mechanisms in enhancing financial stability, particularly in African markets.
