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Efficient first-principles electronic transport approach to complex band structure materials : the case of n -type Mg 3 Sb 2
Get PDFWe present an efficient method for accurately computing electronic scattering rates and transport properties in materials with complex band structures. Using ab initio simulations, we calculate a limited number of electron–phonon matrix elements, and extract scattering rates for acoustic and optical processes based on deformation potential theory. Polar optical phonon scattering rates are determined using the Fröhlich model, and ionized impurity scattering rates are derived from the Brooks-Herring theory. Subsequently, electronic transport coefficients are computed within the Boltzmann transport theory. We exemplify our approach with n-type Mg3Sb2, a promising thermoelectric material with a challenging large unit cell and low symmetry. Notably, our method attains competitive accuracy, requiring less than 10% of the computational cost compared to state-of-the-art ab initio methods, dropping to 1% for simpler materials. Additionally, our approach provides explicit information on individual scattering processes, offering an alternative that combines efficiency, robustness, and flexibility beyond the commonly employed constant relaxation time approximation with the accuracy of fully first-principles calculations
Magnetotransport of Sm2Ir2O7 across the pressure-induced quantum-critical phase boundary
No full textA monument to E.G. Wakefield : new and historical materialist dialogues for a posthuman international law
No full textIn this chapter, we consider a posthumanist critique of international law in relation to the material world. Our perspective on posthumanism and international law is framed by a monument of Edward Gibbon Wakefield, the so-called ‘founding father’ of the colony of South Australia. Centering the monument in our dialogue, we discuss two types of materialism: New materialism and historical materialism. We argue that an engagement with new and old materialism opens possibilities for a critical engagement with posthumanism. Central to this critical engagement are themes of materiality, settler colonialism, agency, and exploitation – themes that are key for understanding the operation of international law. By identifying where
the materialist theories differ, and also where they converge, we ultimately seek to identify the utility of a posthumanist critique for destabilising international law’s imperialist, capitalist, racialized and patriarchal structures
Self-supervised adaptive weighting for cooperative perception in V2V communications
Get PDFPerception of the driving environment is critical for collision avoidance and route planning to ensure driving safety. Cooperative perception has been widely studied as an effective approach to addressing the shortcomings of single-vehicle perception. However, the practical limitations of vehicle-to-vehicle (V2V) communications have not been adequately investigated. In particular, current cooperative fusion models rely on supervised models and do not address dynamic performance degradation caused by arbitrary channel impairments. In this paper, a self-supervised adaptive weighting model is proposed for intermediate fusion to mitigate the adverse effects of channel distortion. The performance of cooperative perception is investigated in different system settings. Rician fading and imperfect channel state information (CSI) are also considered. Numerical results demonstrate that the proposed adaptive weighting algorithm significantly outperforms the benchmarks without weighting. Visualization examples validate that the proposed weighting algorithm can flexibly adapt to various channel conditions. Moreover, the adaptive weighting algorithm demonstrates good generalization to untrained channels and test datasets from different domains
Positive Family Connections for families of children with a developmental disability : cluster randomized controlled trial
Get PDFPositive Family Connections is a co-produced, positively-oriented, family-systems program for families of children with a developmental disability aged 8-13 years. The study was a feasibility cluster randomized-controlled trial registered prospectively (ISRCTN 14809884). Families (clusters) were randomized 1:1 to take part in Positive Family Connections immediately or to a waitlist condition and were followed up 4-months and 9-months after randomization. Feasibility outcomes included participant and facilitator recruitment rates, retention, intervention adherence, and fidelity. The proposed primary outcome measure was the family APGAR, a measure of family functioning. Quantitative data were analyzed using multilevel modelling. 60 families (60 primary parental carers and 13 second carers) were randomized. 73.33% of primary parental carers and 71.43% of second carers in the intervention group attended ≥4 intervention sessions and fidelity of delivery was high (mean=94.02% intervention components delivered). Retention for the proposed primary outcome was 97.26% at 4-month follow-up and 98.63% at 9-month follow-up. Intervention condition was not associated with family APGAR scores at 9-month follow-up (estimate=0.06, 95% CI= -0.49, 0.61, p=0.86, Hedges g=0.03, 95% CI=-0.43, 0.49). However, meaningful improvements were observed for other secondary outcomes related to parental wellbeing and family relationships. A definitive randomized-controlled trial of Positive Family Connections is feasible. Preliminary evaluation of outcomes shows that Positive Family Connections may be beneficial for parental psychological wellbeing and family relationships
Deep labeller : automatic bounding box generation for synthetic violence detection datasets
Get PDFManually labelling datasets for training violence detection systems is time-consuming, expensive, and labor-intensive. Mind wandering, boredom, and short attention span can also cause labelling errors. Moreover, collecting and distributing sensitive images containing violence has ethical implications. Automation is the future for labelling sensitive image datasets. Deep labeller is a two-stage Deep Learning (DL) method that uses pre-trained DL object detection methods on MS-COCO for automatic labelling. The Deep Labeller method labels violent and nonviolent images in WVD and USI. In stage 1, WVD generates weak labels using synthetic images. In stage 2, the Deep labeller method is retrained on weak labels. USI dataset is used to test our method on real-world violence. Deep labeller generated weak and strong labels with an IoU of 0.80036 in stage 1 and 0.95 in stage 2 on the WVD. Automatically generated labels. To test our method’s generalisation power, violent and nonviolent image labels on USI dataset had a mean IoU of 0.7450
T-Shaped palladium and platinum {MNO}10 nitrosyl complexes
No full textThe synthesis and characterization of a homologous series of T-shaped {MNO}10 nitrosyl complexes of the form [M(PR3)2(NO)]+ (M = Pd, Pt; R = tBu, Ad) are reported. These diamagnetic nitrosyls are obtained from monovalent or zerovalent precursors by treatment with NO and NO+, respectively, and are notable for distinctly bent M–NO angles of ∼123° in the solid state. Adoption of this coordination mode in solution is also supported by the analysis of isotopically enriched samples by 15N NMR spectroscopy. Effective oxidation states of M0/NO+ are calculated, and metal–nitrosyl bonding has been interrogated using DFT-based energy decomposition analysis techniques. While a linear nitrosyl coordination mode was found to be electronically preferred, the M–NO and P–M–P angles are inversely correlated to the extent that binding in this manner is prevented by steric repulsion between the bulky ancillary phosphine ligands