Responsible Urban Intelligence: Towards a Research Agenda

Acceleration of urbanisation is posing great challenges to sustainable development. Growing accessibility to big data and artificial intelligence (AI) technologies have revolutionised many fields and offered great potential for addressing pressing urban problems. However, using these technologies without explicitly considering responsibilities would bring new societal and environmental issues. To maximise the benefits of big data and AI while minimising potential issues, we envisage a conceptual framework of Responsible Urban Intelligence (RUI) and advocate an agenda for action. We first define RUI as consisting of three major components including urban problems, enabling technologies, and responsibilities; then introduce transparency, fairness, and eco-friendliness as the three dimensions of responsibilities which naturally link with the human, space, and time dimensions of cities; and further develop a four-stage implementation framework for responsibilities as consisting of solution design, data preparation, model building, and practical application; and finally present a research agenda for RUI addressing challenging issues including data and model transparency, tension between performance and fairness, and solving urban problems in an eco-friendly manner

An unstructured-grid, finite-volume sea ice model : development, validation, and application

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C00D04, doi:10.1029/2010JC006688.A sea ice model was developed by converting the Community Ice Code (CICE) into an unstructured-grid, finite-volume version (named UG-CICE). The governing equations were discretized with flux forms over control volumes in the computational domain configured with nonoverlapped triangular meshes in the horizontal and solved using a second-order accurate finite-volume solver. Implementing UG-CICE into the Arctic Ocean finite-volume community ocean model provides a new unstructured-grid, MPI-parallelized model system to resolve the ice-ocean interaction dynamics that frequently occur over complex irregular coastal geometries and steep bottom slopes. UG-CICE was first validated for three benchmark test problems to ensure its capability of repeating the ice dynamics features found in CICE and then for sea ice simulation in the Arctic Ocean under climatologic forcing conditions. The model-data comparison results demonstrate that UG-CICE is robust enough to simulate the seasonal variability of the sea ice concentration, ice coverage, and ice drifting in the Arctic Ocean and adjacent coastal regions.This work was supported by the NSF Arctic Program for projects with grant numbers of ARC0712903, ARC0732084, and ARC0804029. The Arctic Ocean Model Intercomparison Project (AOMIP) has provided an important guidance for model improvements and ocean studies under coordinated experiments activities. We would like to thank AOMIP PI Proshutinsky for his valuable suggestions and comments on the ice dynamics. His contribution is supported by ARC0800400 and ARC0712848. The development of FVCOM was supported by the Massachusetts Marine Fisheries Institute NOAA grants DOC/NOAA/ NA04NMF4720332 and DOC/NOAA/NA05NMF4721131; the NSF Ocean Science Program for projects of OCE‐0234545, OCE‐0227679, OCE‐ 0606928, OCE‐0712903, OCE‐0726851, and OCE‐0814505; MIT Sea Grant funds (2006‐RC‐103 and 2010‐R/RC‐116); and NOAA NERACOOS Program for the UMASS team. G. Gao was also supported by the Chinese NSF Arctic Ocean grant under contract 40476007. C. Chen’s contribution was also supported by Shanghai Ocean University International Cooperation Program (A‐2302‐10‐0003), the Program of Science and Technology Commission of Shanghai Municipality (09320503700), the Leading Academic Discipline Project of Shanghai Municipal Education Commission (J50702), and Zhi jiang Scholar and 111 project funds of the State Key Laboratory for Estuarine and Coastal Research, East China Normal University (ECNU)

Organophosphate Ester Flame Retardants and Plasticizers in ocean sediments from the North Pacific to the Arctic Ocean

The occurence of organophosphate ester (OPE) flame retardants and plasticizers in surface sediment from the North Pacific to Arctic Ocean was observed for the first time during the fourth National Arctic Research Expedition of China in the summer of 2010. The samples were analyzed for three halogenated OPEs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(dichloroisopropyl) phosphate], three alkylated OPEs [triisobutyl phosphate (TiBP), tri-n-butyl phosphate, and tripentyl phosphate], and triphenyl phosphate. Σ7OPEs (total concentration of the observed OPEs) was in the range of 159–4658 pg/g of dry weight. Halogenated OPEs were generally more abundant than the nonhalogenated OPEs; TCEP and TiBP dominated the overall concentrations. Except for that of the Bering Sea, Σ7OPEs values increased with increasing latitudes from Bering Strait to the Central Arctic Ocean, while the contributions of halogenated OPEs (typically TCEP and TCPP) to the total OPE profile also increased from the Bering Strait to the Central Arctic Ocean, indicating they are more likely to be transported to the remote Arctic. The median budget of 52 (range of 17–292) tons for Σ7OPEs in sediment from the Central Arctic Ocean represents only a very small amount of their total production volume, yet the amount of OPEs in Arctic Ocean sediment was significantly larger than the sum of polybrominated diphenyl ethers (PBDEs) in the sediment, indicating they are equally prone to long-range transport away from source regions. Given the increasing level of production and usage of OPEs as substitutes of PBDEs, OPEs will continue to accumulate in the remote Arctic

Strong affinity of polysulfide intermediates to multi-functional binder for practical application in lithium-sulfur batteries

Binder, one of the most important battery components, plays a critical role in lithium-sulfur batteries. Poly(vinylidene difluoride) (PVDF), a commonly used binder in lithium-sulfur batteries, does not have a strong affinity to the intermediate polysulfides, however, leading to fast capacity fading with electrochemical cycling. Herein, copolymers of vinylidene difluoride with other monomers are used as multi-functional binders to enhance the electrochemical performance of lithium-sulfur batteries. Compared to the PVDF, the copolymer, poly(vinylidene difluoride-trifluoroethylene) (P(VDF-TRFE)) binder exhibits higher adhesion strength, less porosity, and stronger chemical interaction with polysulfides, which helps to keep the polysulfides within the cathode region, thereby improving the electrochemical performance of the lithium-sulfur battery. As a result, sulfur electrode with P(VDF-TRFE) binder delivered a high capacity of 801 mA h g-1 at 0.2 C after 100 cycles, which is nearly 80% higher capacity than the corresponding sulfur cathode with PVDF binder

Seasonal and interannual variability of the Arctic sea ice : a comparison between AO-FVCOM and observations

Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 8320–8350, doi:10.1002/2016JC011841.A high-resolution (up to 2 km), unstructured-grid, fully ice-sea coupled Arctic Ocean Finite-Volume Community Ocean Model (AO-FVCOM) was used to simulate the sea ice in the Arctic over the period 1978–2014. The spatial-varying horizontal model resolution was designed to better resolve both topographic and baroclinic dynamics scales over the Arctic slope and narrow straits. The model-simulated sea ice was in good agreement with available observed sea ice extent, concentration, drift velocity and thickness, not only in seasonal and interannual variability but also in spatial distribution. Compared with six other Arctic Ocean models (ECCO2, GSFC, INMOM, ORCA, NAME, and UW), the AO-FVCOM-simulated ice thickness showed a higher mean correlation coefficient of ∼0.63 and a smaller residual with observations. Model-produced ice drift speed and direction errors varied with wind speed: the speed and direction errors increased and decreased as the wind speed increased, respectively. Efforts were made to examine the influences of parameterizations of air-ice external and ice-water interfacial stresses on the model-produced bias. The ice drift direction was more sensitive to air-ice drag coefficients and turning angles than the ice drift speed. Increasing or decreasing either 10% in water-ice drag coefficient or 10° in water-ice turning angle did not show a significant influence on the ice drift velocity simulation results although the sea ice drift speed was more sensitive to these two parameters than the sea ice drift direction. Using the COARE 4.0-derived parameterization of air-water drag coefficient for wind stress did not significantly influence the ice drift velocity simulation.This work was supported by NSF grants OCE-1203393 for the UMASSD team and PLR-1203643 for R. C. Beardsley.2017-05-2

Adult restoration of Shank3 expression rescues selective autistic-like phenotypes

Because autism spectrum disorders are neurodevelopmental disorders and patients typically display symptoms before the age of three, one of the key questions in autism research is whether the pathology is reversible in adults. Here we investigate the developmental requirement of Shank3 in mice, a prominent monogenic autism gene that is estimated to contribute to approximately 1% of all autism spectrum disorder cases. SHANK3 is a postsynaptic scaffold protein that regulates synaptic development, function and plasticity by orchestrating the assembly of post synaptic density macromolecular signalling complex. Disruptions of the Shank3 gene in mouse models have resulted in synaptic defects and autistic-like behaviours including anxiety, social interaction deficits, and repetitive behaviour. We generated a novel Shank3 conditional knock-in mouse model, and show that re-expression of the Shank3 gene in adult mice led to improvements in synaptic protein composition, spine density and neural function in the striatum. We also provide behavioural evidence that certain behavioural abnormalities including social interaction deficit and repetitive grooming behaviour could be rescued, while anxiety and motor coordination deficit could not be recovered in adulthood. Together, these results reveal the profound effect of post-developmental activation of Shank3 expression on neural function, and demonstrate a certain degree of continued plasticity in the adult diseased brain.National Institutes of Health (U.S.) (Grant R01MH097104

Visual-Guided Mesh Repair

Mesh repair is a long-standing challenge in computer graphics and related fields. Converting defective meshes into watertight manifold meshes can greatly benefit downstream applications such as geometric processing, simulation, fabrication, learning, and synthesis. In this work, we first introduce three visual measures for visibility, orientation, and openness, based on ray-tracing. We then present a novel mesh repair framework that incorporates visual measures with several critical steps, i.e., open surface closing, face reorientation, and global optimization, to effectively repair defective meshes, including gaps, holes, self-intersections, degenerate elements, and inconsistent orientations. Our method reduces unnecessary mesh complexity without compromising geometric accuracy or visual quality while preserving input attributes such as UV coordinates for rendering. We evaluate our approach on hundreds of models randomly selected from ShapeNet and Thingi10K, demonstrating its effectiveness and robustness compared to existing approaches

Persistent organic pollutants in ocean sediments from the North Pacific to the Arctic Ocean

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OC pesticides), and polybrominated diphenyl ethers (PBDEs) are reported in surficial sediments sampled along cruise transects from the Bering Sea to the central Arctic Ocean. OCs and PCBs all had significantly higher concentrations in the relatively shallow water (500 m) of the Bering Sea and Arctic Ocean (e.g., Canada Basin ΣPCB 149 ± 102 pg g−1 dw). Concentrations were similar to, or slightly lower than, studies from the 1990s, indicating a lack of a declining trend. PBDEs (excluding BDE-209) displayed very low concentrations (e.g., range of median values, 3.5–6.6 pg/g dw). In the shelf areas, the sediments comprised similar proportions of silt and clay, whereas the deep basin sediments were dominated by clay, with a lower total organic carbon (TOC) content. While significant positive correlations were observed between persistent organic pollutant (POP) concentrations and TOC (Pearson correlation, r = 0.66–0.75, p <0.05), the lack of strong correlations, combined with differing chemical profiles between the sediments and technical formulations (and/or marine surface waters), indicate substantial chemical processing during transfer to the benthic environment. Marked differences in sedimentation rates between the shallow and deeper water regions are apparent (the ∼5 cm-depth grab samples collected here representing ∼100 years of accumulation for the shelf sediments and ∼1000 years for the deeper ocean regions), which may bias any comparisons. Nonetheless, the sediments of the shallower coastal arctic seas appear to serve as significant repositories for POPs deposited from surface waters