2,170 research outputs found

    Object recognition using shape-from-shading

    Get PDF
    This paper investigates whether surface topography information extracted from intensity images using a recently reported shape-from-shading (SFS) algorithm can be used for the purposes of 3D object recognition. We consider how curvature and shape-index information delivered by this algorithm can be used to recognize objects based on their surface topography. We explore two contrasting object recognition strategies. The first of these is based on a low-level attribute summary and uses histograms of curvature and orientation measurements. The second approach is based on the structural arrangement of constant shape-index maximal patches and their associated region attributes. We show that region curvedness and a string ordering of the regions according to size provides recognition accuracy of about 96 percent. By polling various recognition schemes. including a graph matching method. we show that a recognition rate of 98-99 percent is achievable

    New constraints on data-closeness and needle map consistency for shape-from-shading

    Get PDF
    This paper makes two contributions to the problem of needle-map recovery using shape-from-shading. First, we provide a geometric update procedure which allows the image irradiance equation to be satisfied as a hard constraint. This not only improves the data closeness of the recovered needle-map, but also removes the necessity for extensive parameter tuning. Second, we exploit the improved ease of control of the new shape-from-shading process to investigate various types of needle-map consistency constraint. The first set of constraints are based on needle-map smoothness. The second avenue of investigation is to use curvature information to impose topographic constraints. Third, we explore ways in which the needle-map is recovered so as to be consistent with the image gradient field. In each case we explore a variety of robust error measures and consistency weighting schemes that can be used to impose the desired constraints on the recovered needle-map. We provide an experimental assessment of the new shape-from-shading framework on both real world images and synthetic images with known ground truth surface normals. The main conclusion drawn from our analysis is that the data-closeness constraint improves the efficiency of shape-from-shading and that both the topographic and gradient consistency constraints improve the fidelity of the recovered needle-map

    Evaluating Consumer Sensory and Composition Attributes of Arkansas-Grown Fresh-Market Blackberries

    Get PDF
    Blackberries are grown worldwide for commercial fresh markets. Three Arkansas-grown fresh-market blackberry genotypes (‘Natchez’, ‘Ouachita’, and A-2418) were evaluated for consumer sensory and compositional attributes at the University of Arkansas Food Science Department, Fayetteville. The compositional attributes of the blackberries were within an acceptable range for commercial markets (soluble solids=8.20-11.90%, pH=2.79-3.18, titratable acidity=1.09-1.32%). In terms of soluble solids to titratable acidity ratio, ‘Ouachita’ (10.92) had the highest ratio, followed by ‘Natchez’ (8.93) and A-2418 (6.25). A consumer sensory panel (n=80) evaluated fresh-market blackberry attributes using a 9-point hedonic scale for overall impression, overall flavor, sweetness, and sourness and a 5-point Just-about-Right (JAR) scale for sweetness and sourness. The participants also ranked the blackberries in order of overall liking from most to least liked. For overall impression, overall flavor, and sweetness, ‘Natchez’ scored higher than ‘Ouachita’ and A-2418, but the panelists did not detect differences in sourness. In terms of JAR for sweetness, 64% of consumers scored ‘Natchez’ JAR, followed by ‘Ouachita’ (39%) and A-2418 (34%). Whereas, 42% percent found A-2418 “Too Sour”, followed by ‘Ouachita (33%) and ‘Natchez’ (25%). In terms of ranking the blackberries, ‘Natchez’ was the most liked blackberry followed by ‘Ouachita’ and A-2418. When looking only at blackberries ranked first, 53% of consumers ranked ‘Natchez’ as their most liked berry, compared to A-2418 (26%) and ‘Ouachita’ (21%). The results from this research suggested that fresh-market blackberries with medium-level sweetness to sourness ratios were preferred though more consumers than expected preferred the blackberries with the more extreme ratios

    Long-period unstable gravity-waves and associated VHF radar echoes

    Get PDF

    Lay Christian Counseling and Client Expectations for Integration in Therapy

    Get PDF
    As lay approaches to Christian counseling have multiplied and become increasingly sophisticated, we hypothesize that these might affect expectations of conservative Christian clients for professional integrative psychotherapy. Accordingly, we review several models of lay counseling, broadly categorizing them into active listening, cognitive & solution-focused approaches, inner healing, and mixed models. We consider how client expectations for psychotherapy may be altered through their experiences with these approaches. Subsequently, we make recommendations for clinicians who deal with lay-counseling-experienced clients. These include doing a more detailed assessment of client lay counseling experiences and considering ethical aspects of treatment (informed consent and competency to treat)

    A statistical study of underestimates of wind speeds by VHF radar

    No full text
    International audienceComparisons are made between horizontal wind measurements carried out using a VHF-radar system at Aberystwyth (52.4°N, 4.1°W) and radiosondes launched from Aberporth, some 50 km to the south-west. The radar wind results are derived from Doppler wind measurements at zenith angles of 6° in two orthogonal planes and in the vertical direction. Measurements on a total of 398 days over a 2-year period are considered, but the major part of the study involves a statistical analysis of data collected during 75 radiosonde flights selected to minimise the spatial separation of the two sets of measurements. Whereas good agreement is found between the two sets of wind direction, radar-derived wind speeds show underestimates of 4?6% compared with radiosonde values over the height range 4?14 km. Studies of the characteristics of this discrepancy in wind speeds have concentrated on its directional dependence, the effects of the spatial separation of the two sets of measurements, and the influence of any uncertainty in the radar measurements of vertical velocities. The aspect sensitivity of radar echoes has previously been suggested as a cause of underestimates of wind speeds by VHF radar. The present statistical treatment and case-studies show that an appropriate correction can be applied using estimates of the effective radar beam angle derived from a comparison of echo powers at zenith angles of 4.2° and 8.5°

    Liquid drop splashing on smooth, rough and textured surfaces

    Full text link
    Splashing occurs when a liquid drop hits a dry solid surface at high velocity. This paper reports experimental studies of how the splash depends on the roughness and the texture of the surfaces as well as the viscosity of the liquid. For smooth surfaces, there is a "corona" splash caused by the presence of air surrounding the drop. There are several regimes that occur as the velocity and liquid viscosity are varied. There is also a "prompt" splash that depends on the roughness and texture of the surfaces. A measurement of the size distribution of the ejected droplets is sensitive to the surface roughness. For a textured surface in which pillars are arranged in a square lattice, experiment shows that the splashing has a four-fold symmetry. The splash occurs predominantly along the diagonal directions. In this geometry, two factors affect splashing the most: the pillar height and spacing between pillars.Comment: 9 pages, 11 figure

    Efficacy of a Workbook to Promote Forgiveness: A Randomized Controlled Trial with University Students

    Get PDF
    Objective The present study investigated the efficacy of a 6-hour self-directed workbook adapted from the REACH Forgiveness intervention. Method Undergraduates (N = 41) were randomly assigned to either an immediate treatment or waitlist control condition. Participants were assessed across 3 time periods using a variety of forgiveness outcome measures. Results The 6-hour workbook intervention increased forgiveness, as indicated by positive changes in participants’ forgiveness ratings that differed by condition. In addition, benchmarking analysis showed that the self-directed workbook intervention is at least as efficacious as the delivery of the REACH Forgiveness model via group therapy. Conclusion A self-directed workbook intervention adapted from the REACH Forgiveness intervention provides an adjunct to traditional psychotherapy that could assist the mental health community to manage the burden of unforgiveness among victims of interpersonal harm
    • 

    corecore