GEOMETRIC AND ALGEBRAIC APPROACHES OF PLANAR STRUCTURE RECOVERY BASED ON PROPERTIES OF DUAL CONIC

Author(s):  
LIANG WANG ◽  
HONGXUN YAO ◽  
SHAOHUI LIU

In this article, approaches of planar Euclidean Structure recovery are proposed based on the geometric and algebraic characteristics of the dual conic. Algebraic relations between the matrix representation of the dual conic and the circular point enveloped are extensively analyzed, to attain a generalized framework for the problem. The dual conic has the decomposition with consistent geometric interpretation from which the circular point envelope can be solved. From the geometric viewpoint, based on the characteristics of the common elements of dual conics (their bitangents), a stratified approach is presented to establish the solution. Experiments on both synthetic and real images are conducted to demonstrate the robustness and accuracy of the presented approach.

2005 ◽  
Vol 24 (s-1) ◽  
pp. 171-193 ◽  
Author(s):  
Michael Gibbins ◽  
Susan A. McCracken ◽  
Steven E. Salterio

Much of what takes place in auditor-client management negotiations occurs in unobservable settings and normally does not result in publicly available archival records. Recent research has increasingly attempted to probe issues relating to accounting negotiations in part due to recent events in the financial world. In this paper, we compare recalls from the two sides of such negotiations, audit partners, and chief financial officers (CFOs), collected in two field questionnaires. We examine the congruency of the auditors' and the CFOs' negotiation recalls for all negotiation elements and features that were common across the two questionnaires (detailed analyses of the questionnaires are reported elsewhere). The results show largely congruent recall: only limited divergences in recall of common elements and features. Specifically, we show a high level of congruency across CFOs and audit partners in the type of issues negotiated, parties involved in resolving the issue, and the elements making up the negotiation process, including agreement on the relative importance of various common accounting contextual features. The analysis of the common accounting contextual features suggests that certain contextual features are consistently important across large numbers of negotiations, whether viewed from the audit partner's or the CFO's perspective, and hence may warrant future study. Finally, the comparative analysis allows us to identify certain common elements and contextual features that may influence both audit partners and CFOs to consider the accounting negotiation setting as mainly distributive (win-lose).


Autism ◽  
2020 ◽  
Vol 24 (8) ◽  
pp. 2285-2297
Author(s):  
Kyle M Frost ◽  
Jessica Brian ◽  
Grace W Gengoux ◽  
Antonio Hardan ◽  
Sarah R Rieth ◽  
...  

Naturalistic developmental behavioral interventions for young children with autism spectrum disorder share key elements. However, the extent of similarity and overlap in techniques among naturalistic developmental behavioral intervention models has not been quantified, and there is no standardized measure for assessing the implementation of their common elements. This article presents a multi-stage process which began with the development of a taxonomy of elements of naturalistic developmental behavioral interventions. Next, intervention experts identified the common elements of naturalistic developmental behavioral interventions using quantitative methods. An observational rating scheme of those common elements, the eight-item NDBI-Fi, was developed. Finally, preliminary analyses of the reliability and the validity of the NDBI-Fi were conducted using archival data from randomized controlled trials of caregiver-implemented naturalistic developmental behavioral interventions, including 87 post-intervention caregiver–child interaction videos from five sites, as well as 29 pre–post video pairs from two sites. Evaluation of the eight-item NDBI-Fi measure revealed promising psychometric properties, including evidence supporting adequate reliability, sensitivity to change, as well as concurrent, convergent, and discriminant validity. Results lend support to the utility of the NDBI-Fi as a measure of caregiver implementation of common elements across naturalistic developmental behavioral intervention models. With additional validation, this unique measure has the potential to advance intervention science in autism spectrum disorder by providing a tool which cuts across a class of evidence-based interventions. Lay abstract Naturalistic developmental behavioral interventions for young children with autism spectrum disorder share key elements. However, the extent of similarity between programs within this class of evidence-based interventions is unknown. There is also currently no tool that can be used to measure the implementation of their common elements. This article presents a multi-stage process which began with defining all intervention elements of naturalistic developmental behavioral interventions. Next, intervention experts identified the common elements of naturalistic developmental behavioral interventions using a survey. An observational rating scheme of those common elements, the eight-item NDBI-Fi, was developed. We evaluated the quality of the NDBI-Fi using videos from completed trials of caregiver-implemented naturalistic developmental behavioral interventions. Results showed that the NDBI-Fi measure has promise; it was sensitive to change, related to other similar measures, and demonstrated adequate agreement between raters. This unique measure has the potential to advance intervention science in autism spectrum disorder by providing a tool to measure the implementation of common elements across naturalistic developmental behavioral intervention models. Given that naturalistic developmental behavioral interventions have numerous shared strategies, this may ease clinicians’ uncertainty about choosing the “right” intervention package. It also suggests that there may not be a need for extensive training in more than one naturalistic developmental behavioral intervention. Future research should determine whether these common elements are part of other treatment approaches to better understand the quality of services children and families receive as part of usual care.


2021 ◽  
pp. 001316442199253
Author(s):  
Robert C. Foster

This article presents some equivalent forms of the common Kuder–Richardson Formula 21 and 20 estimators for nondichotomous data belonging to certain other exponential families, such as Poisson count data, exponential data, or geometric counts of trials until failure. Using the generalized framework of Foster (2020), an equation for the reliability for a subset of the natural exponential family have quadratic variance function is derived for known population parameters, and both formulas are shown to be different plug-in estimators of this quantity. The equivalent Kuder–Richardson Formulas 20 and 21 are given for six different natural exponential families, and these match earlier derivations in the case of binomial and Poisson data. Simulations show performance exceeding that of Cronbach’s alpha in terms of root mean square error when the formula matching the correct exponential family is used, and a discussion of Jensen’s inequality suggests explanations for peculiarities of the bias and standard error of the simulations across the different exponential families.


Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 1014
Author(s):  
Polly-Anne Jeffrey ◽  
Martín López-García ◽  
Mario Castro ◽  
Grant Lythe ◽  
Carmen Molina-París

Cellular receptors on the cell membrane can bind ligand molecules in the extra-cellular medium to form ligand-bound monomers. These interactions ultimately determine the fate of a cell through the resulting intra-cellular signalling cascades. Often, several receptor types can bind a shared ligand leading to the formation of different monomeric complexes, and in turn to competition for the common ligand. Here, we describe competition between two receptors which bind a common ligand in terms of a bi-variate stochastic process. The stochastic description is important to account for fluctuations in the number of molecules. Our interest is in computing two summary statistics—the steady-state distribution of the number of bound monomers and the time to reach a threshold number of monomers of a given kind. The matrix-analytic approach developed in this manuscript is exact, but becomes impractical as the number of molecules in the system increases. Thus, we present novel approximations which can work under low-to-moderate competition scenarios. Our results apply to systems with a larger number of population species (i.e., receptors) competing for a common resource (i.e., ligands), and to competition systems outside the area of molecular dynamics, such as Mathematical Ecology.


1965 ◽  
Vol 13 (3) ◽  
pp. 155-160 ◽  
Author(s):  
H. J. KEUTEL

Fluorescent labeled antibodies were used for the demonstration of uromucoid. This urine specific mucoprotein is demonstrably present only in the epithelial cells of the proximal segments of the normal human renal tubules and in the matrix of human kidney stones of all the common crystalline compositions.


Legal Studies ◽  
2001 ◽  
Vol 21 (2) ◽  
pp. 153-191 ◽  
Author(s):  
Joachim Dietrich

The common law has solved questions of liability arising in the context of precontractual negotiations by resort to a range of different doctrines and approaches, adopting in effect ‘piecemeal’ solutions to questions of precontractual liability. Consequently, debate has arisen as to how best to classify or categorise claims for precontractual work and as to which doctrines are best suited to solving problems arising from anticipated contracts. The purpose of this article is to consider this question of how best to classify (cases of) precontractual liability. The initial focus will be on the ongoing debate as to whether principles of contract law or principles of unjust enrichment can better solve problems of precontractual liability. I will be suggesting that unjust enrichment theory offers little by way of explanation of cases of precontractual liability and, indeed, draws on principles of contract law in determining questions of liability for precontractual services rendered, though it does so by formulating those principles under different guises. Irrespective, however, of the doctrines utilised by the common law to impose liability, it is possible to identify a number of common elements unifying all cases of precontractual liability. In identifying such common elements of liability, it is necessary to draw on principles of both contract and tort law. How, then, should cases of precontractual liability best be classified? A consideration of the issue of classification of precontractual liability from a perspective of German civil law will demonstrate that a better understanding of cases of precontractual liability will be gained by classifying such cases as lying between the existing categories of contract and tort.


2000 ◽  
Vol 51 (2) ◽  
pp. 183 ◽  
Author(s):  
Maria Byrne ◽  
Peter A. Vesk

The Australian freshwater mussel Hyridella depressa sequesters elements in calcium phosphate (CaP) granules that form extensive aggregations in its tissues. Elements contained in these granules were determined by X-ray microanalysis of river and lake mussels from the Hawkesbury–Nepean River system, New South Wales. Granules in freeze-substituted mantle tissue were analysed to determine the variation in element profiles in granules among mussels and among sites. For the common elements Ca, P, Fe, Mg and Mn, granule composition reflected catchment lithology and site trophic status and indicated exogenous input. These were most important for differentiation among lake sites and also indicated differences between lake and river mussels. Site differences seen with some common elements in granules from lake mussels correlated with differences in water chemistry. Trace elements, particularly Al, Cu, Zn and Pb, were also important in lake and river site differentiation. The granules play a major role in element dynamics in freshwater mussel tissues and provide a focal structure for direct analysis of element accumulation by these bivalves. The results indicate that characterization of element content of granules in mussel populations would provide valuable insights into animal–element interactions in freshwater systems for ecological and ecotoxicological investigations.


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