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Calderon, F., Lozada, A., Morales, P., Borquez-Paredes, D., Jara, N., Olivares, R., et al. (2022). Multi-band elastic optical networks are a promising alternative to meet the bandwidth demand of the ever-growing Internet traffic. In this letter, we propose a family of band allocation algorithms for multi-band elastic optical networks. Employing simulation, we evaluate the blocking performance of 3 algorithms of such a family and compare their performance with the only heuristic proposed to date. Results show that the three new algorithms outperform the previous proposal, with up to one order of magnitude improvement. We expect these results to help advance the area of dynamic resource allocation in multi-band elastic optical networks. IEEE Commun. Lett., 26(2), 379–383.
Abstract: Multi-band elastic optical networks are a promising alternative to meet the bandwidth demand of the ever-growing Internet traffic. In this letter, we propose a family of band allocation algorithms for multi-band elastic optical networks. Employing simulation, we evaluate the blocking performance of 3 algorithms of such a family and compare their performance with the only heuristic proposed to date. Results show that the three new algorithms outperform the previous proposal, with up to one order of magnitude improvement. We expect these results to help advance the area of dynamic resource allocation in multi-band elastic optical networks.
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Carbonnel, C., Romero, M., & Zivny, S. (2022). The Complexity of General-Valued Constraint Satisfaction Problems Seen from the Other Side. SIAM J. Comput., 51(1), 19–69.
Abstract: The constraint satisfaction problem (CSP) is concerned with homomorphisms between two structures. For CSPs with restricted left-hand-side structures, the results of Dalmau, Languages and Programming, Springer, New York, 2007, pp. 279--290] establish the precise borderline of polynomial-time solvability (subject to complexity-theoretic assumptions) and of solvability by bounded-consistency algorithms (unconditionally) as bounded treewidth modulo homomorphic equivalence. The general-valued constraint satisfaction problem (VCSP) is a generalization of the CSP concerned with homomorphisms between two valued structures. For VCSPs with restricted left-hand-side valued structures, we establish the precise borderline of polynomial-time solvability (subject to complexity-theoretic assumptions) and of solvability by the kth level of the Sherali--Adams LP hierarchy (unconditionally). We also obtain results on related problems concerned with finding a solution and recognizing the tractable cases; the latter has an application in database theory.
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Goles, E., Medina, P., Montealegre, P., & Santivanez, J. (2022). Majority networks and consensus dynamics. Chaos Solitons Fractals, 164, 112697.
Abstract: Consensus is an emergent property of many complex systems, considering this as an absolute majority phenomenon. In this work we study consensus dynamics in grids (in silicon), where individuals (the vertices) with two possible opinions (binary states) interact with the eight nearest neighbors (Moore’s neighborhood). Dynamics emerge once the majority rule drives the evolution of the system. In this work, we fully characterize the sub-neighborhoods on which the consensus may be reached or not. Given this, we study the quality of the consensus proposing two new measures, namely effectiveness and efficiency. We characterize attraction basins through the energy-like and magnetization-like functions similar to the Ising spin model.
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Grigioni, I., Polo, A., Dozzi, M. V., Stamplecoskie, K. G., Jara, D. H., Kamat, P. V., et al. (2022). Enhanced Charge Carrier Separation in WO3/BiVO4 Photoanodes Achieved via Light Absorption in the BiVO4 Layer. ACS Appl. Energy Mater., 5(11), 13142–13148.
Abstract: Photoelectrochemical (PEC) water splitting converts solar light and water into oxygen and energy-rich hydrogen. WO3/BiVO4 heterojunction photoanodes perform much better than the separate oxide components, though internal charge recombination undermines their PEC performance when both oxides absorb light. Here we exploit the BiVO4 layer to sensitize WO3 to visible light and shield it from direct photoexcitation to overcome this efficiency loss. PEC experiments and ultrafast transient absorption spectroscopy performed by frontside (through BiVO4) or backside (through WO3) irradiating photoanodes with different BiVO4 layer thickness demonstrate that irradiation through BiVO4 is beneficial for charge separation. Optimized electrodes irradiated through BiVO4 show 40% higher photocurrent density compared to backside irradiation.
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Ocampo-Melgar, A., Barria, P., Chadwick, C., & Diaz-Vasconcellos, R. (2022). Rural transformation and differential vulnerability: Exploring adaptation strategies to water scarcity in the Aculeo Lake basin. Front. Environ. Sci., 10, 955023.
Abstract: The way of life of agricultural rural territories and their long-term capacity to adapt to changes will be challenged not only by the impacts of climate change; but by increased vulnerability stemming from previous inadequate climate adaptations and development policies. Studies that deepen understanding of the differential causes and implications of vulnerabilities will improve adaptation or transformation of institutions for climate change. The Aculeo basin of Central Chile suffered an extreme 10-years rainfall deficit that resulted in the disappearance of a 12 km(2) lake and the economic transformation of the territory. This paper presents a cross-scale exploration of the political, cultural and historical interconnections behind this dramatic story, while critically discussing whether today's land use configuration reflects the territory's adaptive capacity. The story is reconstructed using land-use change analysis along with literature review and Causal-Loop Analysis. Results show how previous policies and other human factors contributed to the agroecosystem transformation, creating different vulnerabilities in different economic sectors. Today, what is observed as disparate capacities to adapt to climatic drought is actually the result of historic exacerbations of the vulnerabilities that had significantly contributed to the water scarcity crisis.
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