| 1. |
- Kåresdotter, Elisie, et al.
(författare)
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Navigating the Currents: Understanding Global Water Cooperation and Conflict Mitigation Dynamics
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The demand for water is increasing rapidly due to growing populations and intensified human activities such as agriculture, industry, and energy production. This has led to increasing concerns about the availability and sustainable use of freshwater, as conflicts over water are reported to have increased while cooperation has declined over the past decade. Further research on water-related conflict and cooperation is needed to improve understanding of key factors and ways to mitigate the conflicts and counteract their escalating trend. This study investigates which main factors relate to and may have affected cooperation and conflict events worldwide in the last 70 years as a basis for understanding how to promote effective water-based cooperation and conflict reduction; investigated factors include, for example, hydro-climatic and socioeconomic ones, with the latter encompassing, e.g., wealth, export dependency, demographic, and water use factors. The study used panel data models and content analysis of reported event descriptions to achieve its aims of identifying main conflict-influencing factors and which of these may contribute to successful conflict mitigation. The results indicate that countries that cooperate experience significant subsequent decrease in conflicts. Cooperation is particularly effective in areas with low water stress, while in high-stress areas, diplomatic efforts combined with economic collaboration can boost resilience and increase conflict resolution effectiveness. Economic robustness and trade incentives to maintain peace are strongly correlated with fewer conflicts. Cooperation with less affluent countries also emerges as influential for fewer conflicts, and stability or even growth in GDP and exports. Cooperation efforts can thus be strategic investments for promoting diplomatic stability and improving a nation's economic standing. Understanding which measures can be successful for conflict mitigation can provide valuable insights to global policymakers and water management leaders, enabling them to avoid future conflicts based on current and projected water availability.
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| 2. |
- Li, Cai, et al.
(författare)
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DMPs based CPG Actor Critic: A Method for Locomotion Learning
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this article, a dynamic motor primitives (DMPs) based CPG-Actor-Critic is proposed to enable locomotion learning on a humanoid (the NAO robot) and a puppy robot (the ghostdog robot). In order to model two types of locomotion with one architecture, a novel application of an existing method to designa CPG architecture for learning locomotion. The method is to a) have an architectural base (4-cell CPG) and, b) have a learning component which is based on an existing method for designing DMPs. Learning locomotion here concerns gait emergence in relation to the robot’s body and prior knowledge. The focus of this article will be on two types of locomotion: crawling on ahumanoid and running on a puppy robot. On the two robots with two different morphologies, our method and architecture can make the robots learn by itself. We also compare the performance with respect to two state-of-the-art reinforcement learning algorithms with provided particular instantiations of ourDMPs-based CPG-Actor-Critic architecture. Finally, based on the analysis of the experimental results, a generic view/architecture for locomotion learning is discussed and introduced in the conclusion.
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| 3. |
- Li, Xuhong, et al.
(författare)
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A Belief Propagation Algorithm for Multipath-based SLAM with Multiple Map Features: A mmWave MIMO Application
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we present a multipath-based simultaneous localization and mapping (SLAM) algorithm that continuously adapts mulitiple map feature (MF) models describing specularly reflected multipath components (MPCs) from flat surfaces and point-scattered MPCs, respectively. We develop a Bayesian model for sequential detection and estimation of interacting MF model parameters, MF states and mobile agent's state including position and orientation. The Bayesian model is represented by a factor graph enabling the use of belief propagation (BP) for efficient computation of the marginal posterior distributions. The algorithm also exploits amplitude information enabling reliable detection of weak MFs associated with MPCs of very low signal-to-noise ratios (SNRs). The performance of the proposed algorithm is evaluated using real millimeter-wave (mmWave) multiple-input-multiple-output (MIMO) measurements with single base station setup. Results demonstrate the excellent localization and mapping performance of the proposed algorithm in challenging dynamic outdoor scenarios.
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| 4. |
- Yang, Hao, et al.
(författare)
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Monolithic FAPbBr3 Photoanode for Photoelectrochemical Water Oxidation with Ultralow-Onset-Potential
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Despite considerable research efforts on photoelectrochemical (PEC) water splitting over the past few decades, its practical application is still impeded by the lack of efficient, stable, and scalable photoelectrodes. Herein, we demonstrate the facile fabrication of a metal-halide perovskite-based photoanode for PEC water oxidation. A hole transport material-free and precious metal-free FAPbBr3 photovoltaic (PV) device is fabricated for the first time to examine the charge separation performance of the FAPbBr3 absorber. With a planar structure using mesoporous carbon as a hole-conducting layer, the device achieved a solar-to-electrical power conversion efficiency of 9.2% and a Voc of 1.4 V. The solar cell architecture is successfully applied to build a monolithic photoanode with the FAPbBr3 absorber, carbon/graphite conductive protection layer, and NiFe catalyst layers for direct photo-driven water oxidation. With suitable energy band alignment and minimal contact loss, the photoanode delivers an ultralow onset potential below 0 V versus a reversible hydrogen electrode and a high applied bias photon-to-current efficiency of 8.5%. Stable operation exceeding 100 h under constant solar illumination is successfully reached by the application of UV filter protection. A detailed photothermal investigation confirms that the photothermal effect can improve the overall performance of the perovskite photoanode. The results in this report are of great significance in guiding the further development of PV material-based photoelectrodes for solar fuel applications.
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