Learning a local-variable model of aromatic and conjugated systems

A collection of new approaches to building and training neural networks, collectively referred to as deep learning, are attracting attention in theoretical chemistry. Several groups aim to replace computationally expensive <i>ab initio</i> quantum mechanics calculations with learned estimators. This raises questions about the representability of complex quantum chemical systems with neural networks. Can local-variable models efficiently approximate nonlocal quantum chemical features? Here, we find that convolutional architectures, those that only aggregate information locally, cannot efficiently represent aromaticity and conjugation in large systems. They cannot represent long-range nonlocality known to be important in quantum chemistry. This study uses aromatic and conjugated systems computed from molecule graphs, though reproducing quantum simulations is the ultimate goal. This task, by definition, is both computable and known to be important to chemistry. The failure of convolutional architectures on this focused task calls into question their use in modeling quantum mechanics. To remedy this heretofore unrecognized deficiency, we introduce a new architecture that propagates information back and forth in waves of nonlinear computation. This architecture is still a local-variable model, and it is both computationally and representationally efficient, processing molecules in sublinear time with far fewer parameters than convolutional networks. Wave-like propagation models aromatic and conjugated systems with high accuracy, and even models the impact of small structural changes on large molecules. This new architecture demonstrates that some nonlocal features of quantum chemistry can be efficiently represented in local variable models

Nuclear shell evolution and in-medium NN interaction

We report on a quantitative study of the evolution of the nuclear shell structure, in particular, effective single-particle energies (ESPEs), based on the spin-tensor decomposition of an effective two-body shell-model interaction. While the global trend of the ESPEs is mainly due to the central term of the effective interaction, variations of shell gaps invoke various components of the in-medium NN force. From a detailed analysis of a well-fitted realistic interaction in the sdpf shell-model space, two most important contributions for the evolution of the N = 20 and N = 28 shell gaps are confirmed to be the central term and the tensor term. The role of the latter is dominant to explain the energy shift of spin-orbit partners. Spin-tensor analysis of microscopic effective interactions in sd, pf, and gds shell-model spaces, contrasted with that of the phenomenologically adjusted ones, shows no evidence of amplification of the tensor component contribution; however, it points toward the neglect of three-body forces in the present microscopic interactions

Work domain analysis and intelligent transport systems: Implications for vehicle design

This article presents a Work Domain Analysis (WDA) of the road transport system in Victoria, Australia. A series of driver information requirements and tasks that could potentially be supported through the use of Intelligent Transport Systems (ITS) are then extracted from the WDA. The potential use of ITS technologies to circumvent these information gaps and provide additional support to drivers is discussed. It is concluded that driver information requirements are currently not entirely satisfied by contemporary vehicle design and also that there are a number of driving tasks that could be further supported through the provision of supplementary systems within vehicles

Beyond sustainable buildings: eco-efficiency to eco-effectiveness through cradle-to-cradle design

Sustainable building development focuses on achieving buildings that meet performance and functionality requirements with minimum adverse impact on the environment. Such eco-efficiency strategies are however not feasible for achieving long-term economic and environmental objectives as they only result in damage reduction without addressing design flaws of contemporary industry. The cradle-to-cradle (C2C) design philosophy which has been described as a paradigm changing innovative platform for achieving ecologically intelligent and environmentally restorative buildings appears to offer an alternative vision which, if embraced, could lead to eco-effectiveness and the achievement of long-term environmental objectives. Adoption of C2C principles in the built environment has however been hindered by several factors especially in a sector where change has always been a very slow process. From a review of extant literature, it is argued that the promotion of current sustainable and/or gree n building strategies - which in themselves are not coherent enough due to their pluralistic meanings and sometimes differing solutions - are a major barrier to the promotion of C2C principles in the built environment. To overcome this barrier to C2C implementation, it is recommended that research should focus on developing clearly defined and measurable C2C targets that can be incorporated into project briefs from the inception of development projects. These targets could enable control, monitoring and comparison of C2C design outcomes with eco-efficient measures as well as serve as a guide for project stakeholders to achieve eco-effective “nutrient” management from the project conceptualization phase to the end of life of the building

Augmented paper applications: Initial user tests of a wireless pattern reader

A handheld pattern reader has been developed to read low visibility conductive patterns on paper. The patterns are formed by masking conductive paper with a non-conductive, printed lacquer. The reader was developed as part of an EU-funded project investigating methods of augmenting paper. Data read from the patterns was used to trigger events in the digital domain. Usability tests were undertaken to investigate the performance of the prototype. Results showed that at this stage of development there was significant variation in performance of the prototype from user to user. Further work is being undertaken to determine the causes of this variability

Outcomes of ab interno trabeculectomy with the trabectome by degree of angle opening.

AimTo analyse ab interno trabeculectomy (AIT) with the trabectome and combined phacoemulsification with AIT (phaco-AIT) by Shaffer angle grade (SG).MethodsProspective study of AIT and phaco-AIT with narrow angles of SG≤2 versus open angles ≥3. Outcomes included intraocular pressure (IOP), medications, complications, secondary surgery and success (IOP &lt;21 mm Hg and &gt;20% reduction without further surgery). Exclusion criteria were missing preoperative data and &lt;1 year follow-up.ResultsOf 671 included cases, at 1 year AIT SG≤2 (n=43) had an IOP reduction of 42% from 27.3±7.4 to 15.7±3.0 mm Hg (p&lt;0.01) versus AIT SG≥3 (n=271) with an IOP reduction of 37% from 26.1±7.8 to 16.4±3.9 mm Hg (p&lt;0.01). In phaco-AIT with SG≤2 (n=48), IOP was reduced 24% from 20.7±7.0 to 15.7±3.6 mm Hg (p&lt;0.01) versus phaco-AIT with SG≥3 (n=309) with an IOP reduction of 25% from 22.6±6.4 to 17.0±3.4 mm Hg (p&lt;0.01). There was no difference between SG≤2 and SG≥3 in reduction of IOP or medications, complications, secondary surgery and success rates (p&gt;0.05).ConclusionsSG≤2 is not associated with worse outcomes in AIT or phaco-AIT

The valuation tool user guide: monetizing Cradle to Cradle®

This User Guide outlines the object, scope and expected deliverables from the Valuation Tool component of the Cradle to Cradle ® C2C BIZZ project. It describes the compendium of subtools that have been developed comprising: i) overview of funding tools; ii) C2C investment appraisal tool; and iii) C2C value indexing tool. The underpinning methodologies, as well as their inherent strengths and limitations are also described. The C2C BIZZ project as a whole aims specifically to promote and enhance the implementation of C2C methods in business site development within North Western Europe (NWE) (PAD, p.14). It is intended to infuse C2C notions into conventional site development, restructuring and management. The primary focus of the project is on planning, building and managing of business sites with C2C credentials (PAD, p.18) using sites in Lille Metropole (La Lainiere), London (London Sustainable Industries Park) and Luxemburg (Ecoparc Windhof) as experimental fields. C2C BIZZ is not concerned with the internal operations and activities of occupiers or users of the developed site. Accordingly, the scope of the valuation tool is confined to the planning, building and management of C2C sites. The deliverable from this component is a compendium of subtools (see Figure 1 below) that may be used to analyse the financial performance of C2C credentials in business sites to aid the making of a business case for such developments and evaluating the financial incentives for particular C2C site development projects. This entire work is premised on the argument that the wider adoption of C2C principles within the built environment depends on the rate of uptake by the private sector. The private sector, being profit driven, are likely to engage in C2C site development if they are convinced of its capacity to contribute to their business goals which ultimately is a return on their investment. The tool development described in this document attempts to provide a framework for collating an evidence base that can assist in articulating the business case for C2C in business site developments

Evolution of transport properties of BaFe2-xRuxAs2 in a wide range of isovalent Ru substitution

The effects of isovalent Ru substitution at the Fe sites of BaFe2-xRuxAs2 are investigated by measuring resistivity and Hall coefficient on high-quality single crystals in a wide range of doping (0 < x < 1.4). Ru substitution weakens the antiferromagnetic (AFM) order, inducing superconductivity for relatively high doping level of 0.4 < x < 0.9. Near the AFM phase boundary, the transport properties show non-Fermi-liquid-like behaviors with a linear-temperature dependence of resistivity and a strong temperature dependence of Hall coefficient with a sign change. Upon higher doping, however, both of them recover conventional Fermi-liquid behaviors. Strong doping dependence of Hall coefficient together with a small magnetoresistance suggest that the anomalous transport properties can be explained in terms of anisotropic charge carrier scattering due to interband AFM fluctuations rather than a conventional multi-band scenario.Comment: 7 pages, 6 figures, submitted to Phys. Rev.