nD modelling: Industry uptake considerations

Purpose – The purpose of this paper is to identify the key enablers and obstacles to the effective adoption and use of nD modelling technology. Design/methodology/approach – This paper explores the feasibility of industry absorbing and diffusing nD modelling technology by considering key technology transfer issues; namely, organisational direction, inter-organisational networks and the knowledge characteristics of technology. Findings from semi-structured interviews around a diagnostic technology transfer framework are used to offer implications for theory and practice. Findings – The results from 15 survey interviews indicate that construction professionals appreciate the potential significant benefits of nD modelling technology, but at present, nD modelling technology is seen as too embryonic; too far removed from construction firms' “comfort zones”; requiring too much investment; and, containing too many risks. Originality/value – The paper stresses that the challenge for nD modelling technology, along with any new technology, is to shift from its “technology push” emphasis, to a more balanced “market orientated” stance, which allows the technology to be shaped by both strategic design concerns, and day-to-day operational needs. If this trajectory is pursued, nD modelling technology could have a positive future

Digit-only sauropod pes trackways from China - evidence of swimming or a preservational phenomenon?

For more than 70 years unusual sauropod trackways have played a pivotal role in debates about the swimming ability of sauropods. Most claims that sauropods could swim have been based on manus-only or manus-dominated trackways. However none of these incomplete trackways has been entirely convincing, and most have proved to be taphonomic artifacts, either undertracks or the result of differential depth of penetration of manus and pes tracks, but otherwise showed the typical pattern of normal walking trackways. Here we report an assemblage of unusual sauropod tracks from the Lower Cretaceous Hekou Group of Gansu Province, northern China, characterized by the preservation of only the pes claw traces, that we interpret as having been left by walking, not buoyant or swimming, individuals. They are interpreted as the result of animals moving on a soft mud-silt substrate, projecting their claws deeply to register their traces on an underlying sand layer where they gained more grip during progression. Other sauropod walking trackways on the same surface with both pes and manus traces preserved, were probably left earlier on relatively firm substrates that predated the deposition of soft mud and silt . Presently, there is no convincing evidence of swimming sauropods from their trackways, which is not to say that sauropods did not swim at all

Effect of Nonlinear Multi-axial Elasticity and Anisotropic Plasticity on Quasi-static Dent Properties of Automotive Steel Sheets

This study investigates the influence of the elasto-plastic properties of automotive steel sheets on the denting behavior and suggests a constitutive modeling approach for reliable dent analysis. The stress strain behaviors of three kinds of steel sheets were measured in uniaxial tension, in-plane biaxial tension and forward-reverse simple shear tests. Advanced constitutive models were employed to capture the plastic anisotropy, reverse loading characteristics such as the Bauschinger effect, and elastic modulus degradation. In particular, the biaxial elastic modulus and its degradation behavior were measured and implemented in the constitutive model. The suggested model significantly improved the prediction of dents compared to the conventional model in terms of the load-displacement curve. Sensitivity studies on the constitutive model demonstrated that mainly plastic anisotropy and elastic behavior of a material influence the panel stiffness, whereas the reverse loading behavior strongly affects the permanent dent depth. (C) 2016 Elsevier Ltd. All rights reserved.1151Ysciescopu

Observations on the Nonlinear Unloading Behavior of Advanced High Strength Steels

The unloading behavior was compared for three different steel grades: a dual-phase steel, a transformation-induced plasticity steel, and a twinning-induced plasticity steel. Steels that harden by phase transformation or deformation twinning exhibited a smaller component of microplastic strain during unloading and a smaller reduction in the chord modulus compared to the conventional hardening steel. As a result, unloading is closer to pure elastic unloading when the TRIP effect or TWIP effect is active.X111513sciescopu

Josephson effects in MgB2 meta masked ion damage junctions

Ion beam damage combined with nanoscale focused ion beam direct milling was used to create manufacturable SNS type Josephson junctions in 100 nm thick MgB$_{2}$ with T$_{C}$ of 38 K. The junctions show non-hysteretic current - voltage characteristics between 36 and 4.2 K. Experimental evidence for the dc and ac Josephson effects in MgB$_{2}$ metal masked ion damage junctions are presented. This technique is particularly useful for prototyping devices due to its simplicity and flexibility of fabrication and has a great potential for high-density integration.Comment: 12 pages, 4 figures, RevTeX4, submitted to AP

Linkless octree using multi-level perfect hashing

The standard C/C++ implementation of a spatial partitioning data structure, such as octree and quadtree, is often inefficient in terms of storage requirements particularly when the memory overhead for maintaining parent-to-child pointers is significant with respect to the amount of actual data in each tree node. In this work, we present a novel data structure that implements uniform spatial partitioning without storing explicit parent-to-child pointer links. Our linkless tree encodes the storage locations of subdivided nodes using perfect hashing while retaining important properties of uniform spatial partitioning trees, such as coarse-to-fine hierarchical representation, efficient storage usage, and efficient random accessibility. We demonstrate the performance of our linkless trees using image compression and path planning examples.postprin

Using genetic algorithms to generate test sequences for complex timed systems

The generation of test data for state based specifications is a computationally expensive process. This problem is magnified if we consider that time con- straints have to be taken into account to govern the transitions of the studied system. The main goal of this paper is to introduce a complete methodology, sup- ported by tools, that addresses this issue by represent- ing the test data generation problem as an optimisa- tion problem. We use heuristics to generate test cases. In order to assess the suitability of our approach we consider two different case studies: a communication protocol and the scientific application BIPS3D. We give details concerning how the test case generation problem can be presented as a search problem and automated. Genetic algorithms (GAs) and random search are used to generate test data and evaluate the approach. GAs outperform random search and seem to scale well as the problem size increases. It is worth to mention that we use a very simple fitness function that can be eas- ily adapted to be used with other evolutionary search techniques

Common Genetic Variant Association with Altered HLA Expression, Synergy with Pyrethroid Exposure, and Risk for Parkinson's Disease: An Observational and Case-Control Study.

Background/objectivesThe common non-coding single nucleotide polymorphism (SNP) rs3129882 in HLA-DRA is associated with risk for idiopathic Parkinson's disease (PD). The location of the SNP in the major histocompatibility complex class II (MHC-II) locus implicates regulation of antigen presentation as a potential mechanism by which immune responses link genetic susceptibility to environmental factors in conferring lifetime risk for PD.MethodsFor immunophenotyping, blood cells from 81 subjects were analyzed by qRT-PCR and flow cytometry. A case-control study was performed on a separate cohort of 962 subjects to determine association of pesticide exposure and the SNP with risk of PD.ResultsHomozygosity for G at this SNP was associated with heightened baseline expression and inducibility of MHC class II molecules in B cells and monocytes from peripheral blood of healthy controls and PD patients. In addition, exposure to a commonly used class of insecticide, pyrethroids, synergized with the risk conferred by this SNP (OR = 2.48, p = 0.007), thereby identifying a novel gene-environment interaction that promotes risk for PD via alterations in immune responses.ConclusionsIn sum, these novel findings suggest that the MHC-II locus may increase susceptibility to PD through presentation of pathogenic, immunodominant antigens and/or a shift toward a more pro-inflammatory CD4+ T cell response in response to specific environmental exposures, such as pyrethroid exposure through genetic or epigenetic mechanisms that modulate MHC-II gene expression

GRB 180620A: Evidence for Late-time Energy Injection

The early optical emission of gamma-ray bursts (GRBs) gives an opportunity to understand the central engine and first stages of these events. About 30% of GRBs present flares whose origin is still a subject of discussion. We present optical photometry of GRB 180620A with the COATLI telescope and RATIR instrument. COATLI started to observe from the end of prompt emission at T + 39.3 s and RATIR from T + 121.4 s. We supplement the optical data with the X-ray light curve from Swift/XRT. We observe an optical flare from T + 110 s to T + 550 s, with a temporal index decay α O,decay = 1.32 ± 0.01, and Δt/t = 1.63, which we interpret as the signature of a reverse shock component. After the initial normal decay the light curves show a long plateau from T + 500 s to T + 7800 s in both X-rays and the optical before decaying again after an achromatic jet break at T + 7800 s. Fluctuations are seen during the plateau phase in the optical. Adding to the complexity of GRB afterglows, the plateau phase (typically associated with the coasting phase of the jet) is seen in this object after the "normal" decay phase (associated with the deceleration phase of the jet), and the jet break phase occurs directly after the plateau. We suggest that this sequence of events can be explained by a rapid deceleration of the jet with t d ≲ 40 s due to the high density of the environment (≈100 cm-3) followed by reactivation of the central engine, which causes the flare and powers the plateau phase

The Hubble Constant from Observations of the Brightest Red Giant Stars in a Virgo-Cluster Galaxy

The Virgo and Fornax clusters of galaxies play central roles in determining the Hubble constant H_0. A powerful and direct way of establishing distances for elliptical galaxies is to use the luminosities of the brightest red-giant stars (the TRGB luminosity, at M_I = -4.2). Here we report the direct observation of the TRGB stars in a dwarf elliptical galaxy in the Virgo cluster. We find its distance to be 15.7 +- 1.5 Megaparsecs, from which we estimate a Hubble constant of H_0 = 77 +- 8 km/s/Mpc. Under the assumption of a low-density Universe with the simplest cosmology, the age of the Universe is no more than 12-13 billion years.Comment: 12 pages, LaTeX, with 2 postscript figures; in press for Nature, July 199