One of the first steps in the identification of human remains is sex estimation. discriminant functions are very useful for this purpose, as they are based on the fundamental premise of the sexual dimorphism in osseou...
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One of the first steps in the identification of human remains is sex estimation. discriminant functions are very useful for this purpose, as they are based on the fundamental premise of the sexual dimorphism in osseous remains. However, the absence of studies of this kind in the thoracic cage is visible, and adequate cause to justify this work. To this purpose, we analysed and measured a set of ribs, R1 to R4, belonging to skeletons of contemporary chronology (1970–2010), in order to obtain discriminant functions enabling sex estimation through equations applied to the rib neck. The sample comes from the Cemetery of San José, which is located at the Laboratory of Anthropology at the University of Granada. All data from this sample was known: ancestry, sex, age-at-death and cause of death. Results showed a percentage of success of approximately 80–88% in ribs R2 to R4, and approximately 85–90% in R1, reaching up to 93.2%. Results from intra-/inter-observer error tests show excellent reproducibility of the method. The data confirms that it is possible to estimate sex from the rib neck.
Of crucial importance to the successful use of artificial neural networks for pattern classification problems is how the appropriate network size can be automatically determined. This issue is addressed by formulating...
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Of crucial importance to the successful use of artificial neural networks for pattern classification problems is how the appropriate network size can be automatically determined. This issue is addressed by formulating the process as an automatic search in the space of functions that corresponds to a subclass of multilayer feedforward networks. Learning is thus a dynamic network construction process which involves adjusting both the network weights and the topology. Adding new hidden units corresponds to extracting higher-level features from the original input features for reducing the residual classification errors. It can be shown that the resultant network approximates a Bayesian classifier that implements the Bayesian decision rule for classification. The empirical results of several pattern classification experiments are also reported.
In this paper, we propose two approaches to obtain accurate classifiers for dealing with multi-category classification problem. Our work is based on one-vs-all strategy where we try to decrease conflicting situations....
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In this paper, we propose two approaches to obtain accurate classifiers for dealing with multi-category classification problem. Our work is based on one-vs-all strategy where we try to decrease conflicting situations. In the first phase of both approaches we employ Genetic Programming to find populations of the best discriminant functions (one population for each class). In addition to traditional function set, like {+, -, *, /}, we utilize other special functions in our binary trees. We also use both negative and positive constants in the terminal nodes of the trees. In the second phase, we employ Ant Colony in our first approach, called GP-Ant, and Genetic Algorithm in the second one, called GP-GA, to find the best combination of discriminant functions found in the previous phase. We also provide a special modification box to modify the decision of our final integrated classifiers, when conflicting situations happen. To cope with conflicting situations, we also utilize an appropriate fitness function in the second phase. We compare our works with both state of the art and basic multi-category classification methods on eight well-known publicly available data sets. Our experimental results show that our methods are statistically significantly better than all the Other classification methods used. (C) 2015 Elsevier B.V. All rights reserved.
A procedure is presented for finding maximum likelihood estimates of the parameters of a mixture of two random walk distributions in two cases, using classified and unclassified observations. Based on small sample siz...
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A procedure is presented for finding maximum likelihood estimates of the parameters of a mixture of two random walk distributions in two cases, using classified and unclassified observations. Based on small sample size, estimation of nonlinear discriminant functions is considered. Throughout simulation experiments, the performance of the corresponding estimated nonlinear discriminant functions is investigated. The total probabilities of misclassification and percentage biases are evaluated and discussed.
The methodology of defining polynomial discriminant functions in a constructive way is presented. discriminant functions should be defined in such a way that they fulfil assumptions of Bernstein's theorem. It allo...
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The methodology of defining polynomial discriminant functions in a constructive way is presented. discriminant functions should be defined in such a way that they fulfil assumptions of Bernstein's theorem. It allows us both to prove a uniform convergence of the method and to estimate a rate of convergence of the interpolating process.
Magellanic Penguins (Spheniscus magellanicus) show little sexual dimorphism, and although males are usually larger than females, sexing by direct observation may be difficult, especially in the case of chicks. In this...
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Magellanic Penguins (Spheniscus magellanicus) show little sexual dimorphism, and although males are usually larger than females, sexing by direct observation may be difficult, especially in the case of chicks. In this paper we evaluate the utility of four different PCR-based sex determination techniques using genomic DNA for sexing Magellanic Penguins. We found that the primer set designed for sex determination in Collared Flycatcher (Ficedula albicollis) also provided a reliable, simple and convenient sexing procedure for Magellanic Penguins. Additionally, we obtained discriminant functions for sexing adults and chicks, sampled at six colonies differing in size and other ecological characteristics. discriminant function for adults used two variables, bill length and bill depth that correctly classified 97% of the birds. discriminant function for chicks included bill length and flipper length and correctly classified 78% of the individuals. Although molecular and biometric approaches could be useful for sexing adult Magellanic Penguins, only molecular procedures proved appropriate for accurately sexing chicks.
Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time o...
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Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients with hypercalcaemia, were consecutively recorded, during six and three months respectively, 5 years apart under similar circumstances. The prevalence of hypercalcaemia was comparable in both populations, being 2.57 and 2.38% respectively (non-significant) (NS). The female/male ratio was 1.9 and 1.7 (NS). The discriminant functions correctly classified 81 and 80%, of the women, respectively (NS) and respectively 75% and 64% of the men (NS) in the first and second recorded populations.
Understanding of the formative conditions of fluvial bedforms is significant for both river management and geological studies. Diagrams showing bedform stability conditions have been widely used for the analyses of se...
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Understanding of the formative conditions of fluvial bedforms is significant for both river management and geological studies. Diagrams showing bedform stability conditions have been widely used for the analyses of sedimentary structures. However, the use of discriminants to determine the boundaries of different bedforms regimes has not yet been explored. In this study, we use discriminant functions to describe formative conditions for a range of fluvial bedforms in a 3-D dimensionless parametric space. We do this by means of discriminant analysis using the Mahalanobis distance. We analyzed 3,793 available laboratory and field data and used these to produce new bedform phase diagrams. These diagrams employ three dimensionless parameters representing properties of flow hydraulics and sediment particles as their axes. The discriminant functions for bedform regimes proposed herein are quadratic functions of three dimensionless parameters and are expressed as curved surfaces in 3-D space. These empirical functions can be used to estimate paleoflow velocities from sedimentary structures. As an example of the reconstruction of hydraulic conditions, we calculated the paleoflow velocity of the 2011 Tohoku-Oki tsunami backwash flow from the sedimentary structures of the tsunami deposit. In so doing, we successfully reconstructed reasonable values of the paleoflow velocities.
The Black-headed Gull Larus ridibundus, like many other gulls, has monomorphic plumage, which impedes sex identification in the field. we analysed the size of the hood, eye ring and wing tip and found that putative or...
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The Black-headed Gull Larus ridibundus, like many other gulls, has monomorphic plumage, which impedes sex identification in the field. we analysed the size of the hood, eye ring and wing tip and found that putative ornaments did not differ between sexes in this species. we formulated a novel discriminant function for Black-headed Gulls using morphometric measurements of live individuals (i.e. total head length, bill depth, and the sixth rectrix length), intentionally excluding data from dead birds, which were on average significantly smaller than their living conspecifics. we also tested cross-application of discriminant functions previously developed for Black-headed Gulls, proving that sexing individuals from different populations, even geographic neighbours, based on a single discriminant function risks errors and showing that discriminant functions cannot be treated as a universal tool for sex identification across space and time.
Elevated nasal resistance, as a result of nasal mucosal swelling and/or adenoidal hyperplasia, has been associated with an increased incidence of mouth breathing, which may lead to alterations in facial morphology. Th...
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Elevated nasal resistance, as a result of nasal mucosal swelling and/or adenoidal hyperplasia, has been associated with an increased incidence of mouth breathing, which may lead to alterations in facial morphology. The classical approach to studying this problem clinically has been through the adoption of percentiles and various other norms. However, these techniques are only crude estimates and are subject to error. We have developed a novel approach to the assessment of nasal resistance measurements that provides the means for its differential diagnosis. Two- and three-parameter discriminant (or classification) functions were found to replicate an experienced orthodontist''s clinical diagnosis very accurately. We also propose the adoption of "sensitivity" when discussing the evaluation and/or success of such models.
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