253 research outputs found
Tiled fuzzy Hough transform for crack detection
Surface cracks can be the bellwether of the failure of any component under loading as it indicates the component's    fracture due to stresses and usage. For this reason,  crack detection is indispensable for the condition monitoring  and quality control of road surfaces. Pavement images have high levels of intensity variation and texture content, hence the crack detection is difficult. Moreover, shallow  cracks result in very low contrast image pixels making  their detection difficult. For these reasons, studies on pavement crack detection is active even after years of research. In this paper, the fuzzy Hough transform is employed, for the first time to detect cracks on any surface. The contribution of texture pixels to the  accumulator array is reduced by using the tiled version  of the Hough transform. Precision values of 78% and a recall  of 72% are obtaining for an image set obtained from an  industrial imaging system containing very low contrast    cracking. When only high contrast crack segments are considered the values move to mid to high 90%
DFT Study of Planar Boron Sheets: A New Template for Hydrogen Storage
We study the hydrogen storage properties of planar boron sheets and compare
them to those of graphene. The binding of molecular hydrogen to the boron sheet
(0.05 eV) is stronger than that to graphene. We find that dispersion of alkali
metal (AM = Li, Na, and K) atoms onto the boron sheet markedly increases
hydrogen binding energies and storage capacities. The unique structure of the
boron sheet presents a template for creating a stable lattice of strongly
bonded metal atoms with a large nearest neighbor distance. In contrast, AM
atoms dispersed on graphene tend to cluster to form a bulk metal. In particular
the boron-Li system is found to be a good candidate for hydrogen storage
purposes. In the fully loaded case this compound can contain up to 10.7 wt. %
molecular hydrogen with an average binding energy of 0.15 eV/H2.Comment: 19 pages, 7 figures, and 3 table
A top-down approach for setting climate targets for buildings: The case of a New Zealand detached house
Climate change mitigation requires the construction of low/zero-carbon buildings, and this is a challenge for designers. The use of Life Cycle Assessment (LCA) provides useful information to support eco-efficiency improvements and therefore, to reduce the climate impacts of building designs. However, it does not provide information about whether a proposed design aligns with achieving the global climate target of limiting global warming to below 1.5C or 2C. This study, therefore, introduces an LCA-based top-down approach for setting climate targets for the whole life cycle of buildings in terms of greenhouse gas emissions. It involves assigning a share of the 2C global carbon budget for 2018-2050 to a country, to the construction sector of the country, and finally to a building. The approach includes a stock model that accounts for the projected growth in the number of buildings and associated climate impacts in a country up to 2050. The proposed approach was applied to a detached house in New Zealand, the most common residential building type in the country; it was found that the climate target of a New Zealand detached house over a 90-year lifetime is 71 tCO2eq. This modelling approach has potential to guide designers and other interested stakeholders in development of building designs enabling the building sector to operate within a selected global climate target (such as the 1.5C or 2C target).fals
Earthquake early warning systems based on low-cost ground motion sensors: A systematic literature review
(c) The Author/sfals
Application of absolute sustainability assessment to new zealand residential dwellings
One approach to supporting the implementation of sustainable activities by industry sectors is the use of climate targets. Such climate targets have potential to be used in design and rating tools for buildings and to support government regulation for the building and construction sector. In this study, the climate targets for New Zealand residential dwellings were calculated based on assigning the global carbon budget (for limiting temperature increase to 1.5 or 2.0 °C during 2018-2050) to three building typologies: detached, medium-density housing and apartments. These budgets were assigned to the pre-existing and new-built dwellings using building stock projections for the nominated period. Separately, the climate impact of new-built dwellings in each of the three residential typologies were assessed using Life Cycle Assessment methodology. For New Zealand residential buildings, new-built dwellings exceed their 1.5 °C climate targets by a factor of 6.7, 6.8 and 10.9 for detached, medium-density housing, and apartments respectively. For the 2.0 °C climate target, these factors are 4.8, 4.8 and 7.7 for detached, medium-density housing, and apartments respectively. The results show that about two-thirds of the climate impact of residential dwellings for the period 2018-2050 is associated with preexisting dwellings rather than new-builds. The operational energy used for space heating, water heating, lighting and plug loads makes the biggest contribution to the climate impact for all typologies of pre-built residential dwellings. For new-built residential dwellings, both the operational energy and the construction materials/products contribute most of the climate impact.fals
A Comparison Between Optical Coherence Tomography Angiography and Fluorescein Angiography for the Imaging of Type 1 Neovascularization.
Purpose: To determine the sensitivity of the combination of optical coherence tomography angiography (OCTA) and structural optical coherence tomography (OCT) for detecting type 1 neovascularization (NV) and to determine significant factors that preclude visualization of type 1 NV using OCTA.
Methods: Multicenter, retrospective cohort study of 115 eyes from 100 patients with type 1 NV. A retrospective review of fluorescein (FA), OCT, and OCTA imaging was performed on a consecutive series of eyes with type 1 NV from five institutions. Unmasked graders utilized FA and structural OCT data to determine the diagnosis of type 1 NV. Masked graders evaluated FA data alone, en face OCTA data alone and combined en face OCTA and structural OCT data to determine the presence of type 1 NV. Sensitivity analyses were performed using combined FA and OCT data as the reference standard.
Results: A total of 105 eyes were diagnosed with type 1 NV using the reference. Of these, 90 (85.7%) could be detected using en face OCTA and structural OCT. The sensitivities of FA data alone and en face OCTA data alone for visualizing type 1 NV were the same (66.7%). Significant factors that precluded visualization of NV using en face OCTA included the height of pigment epithelial detachment, low signal strength, and treatment-naïve disease (P \u3c 0.05, respectively).
Conclusions: En face OCTA and structural OCT showed better detection of type 1 NV than either FA alone or en face OCTA alone. Combining en face OCTA and structural OCT information may therefore be a useful way to noninvasively diagnose and monitor the treatment of type 1 NV
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background 
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Exploring the factors influencing farmers' purchase behavior towards submersible pumps: A PLS-structural equation modeling study in Coimbatore district
Submersible pumps are increasingly being utilised to facilitate irrigation, providing farmers with a dependable mean to access groundwater. Efficient water management is crucial for enhancing agricultural productivity, with irrigation playing an important role in crop development. The purpose of this research is to examine the factors influencing farmers’ purchasing behaviour for submersible pumps in the Coimbatore region. Data were collected from 380 farmers using a convenience sampling method, employing a well-prepared interview schedule. The study aims to gain a better understanding of how various attributes such as price (P), durability (D), brand loyalty (BL), dealer recommendation (DR), warranty (W), product quality (PQ), spare parts availability (SPA), and after-sales service (AS) influence farmers' purchasing decisions for submersible pumps. Partial Least Squares Structural Equation Modelling (PLS-SEM) was employed to analyse the data. The results revealed that factors such as AS, BL, DR, P, and PQ significantly influenced farmers’ purchasing decisions for submersible pumps. The findings underscore the need for regulations that enhance the availability and accessibility of high-quality submersible pumps, along with the development of efficient marketing methods that address the specific needs of farmers
Lifetime climate impacts of diet transitions: a novel climate change accounting perspective
Dietary transitions, such as eliminating meat consumption, have been proposed as one way to reduce the climate impact of the global and regional food systems. However, it should be ensured that replacement diets are indeed nutritious and that climate benefits are accurately accounted for. This study uses New Zealand food consumption as a case study for exploring the cumulative climate impact of adopting the national dietary guidelines and the substitution of meat from hypothetical diets. The new GWP* metric is used as it was designed to better reflect the climate impacts of the release of methane than the de facto standard 100-year Global Warming Potential metric (GWP100). A transition at age 25 to the hypothetical dietary guideline diet reduces cumulative warming associated with diet by 7 to 9% at the 100th year compared with consuming the average New Zealand diet. The reduction in diet-related cumulative warming from the transition to a hypothetical meat-substituted diet varied between 12 and 15%. This is equivalent to reducing an average individual's lifetime warming contribution by 2 to 4%. General improvements are achieved for nutrient intakes by adopting the dietary guidelines compared with the average New Zealand diet; however, the substitution of meat items results in characteristic nutrient differences, and these differences must be considered alongside changes in emission profiles.fals
Full-field Chromatic Pupillometry for the Assessment of the Postillumination Pupil Response Driven by Melanopsin-Containing Retinal Ganglion Cells
Citation: Lei S, Goltz HC, Chandrakumar M, Wong AMF. Full-field chromatic pupillometry for the assessment of the postillumination pupil response driven by melanopsin-containing retinal ganglion cells. Invest Ophthalmol Vis Sci. 2014;55:4496-4503
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