Modeling skull-face anatomical/morphological correspondence for craniofacial superimposition-based identification

Craniofacial superimposition (CFS) is a forensic identification technique which studies the anatomical and morphological correspondence between a skull and a face. It involves the process of overlaying a variable number of facial images with the skull. This technique has great potential since nowadays the wide majority of the people have photographs where their faces are clearly visible. In addition, the skull is a bone that hardly degrades under the effect of fire, humidity, temperature changes, etc. Three consecutive stages for the CFS process have been distinguished: the acquisition and processing of the materials; the skull-face overlay; and the decision making. This final stage consists of determining the degree of support for a match based on the previous overlays. The final decision is guided by different criteria depending on the anatomical relations between the skull and the face. In previous approaches, we proposed a framework for automating this stage at different levels taking into consideration all the information and uncertainty sources involved. In this study, we model new anatomical skull-face regions and we tackle the last level of the hierarchical decision support system. For the first time, we present a complete system which provides a final degree of craniofacial correspondence. Furthermore, we validate our system as an automatic identification tool analyzing its capabilities in closed (known information or a potential list of those involved) and open lists (little or no idea at first who may be involved) and comparing its performance with the manual results achieved by experts, obtaining a remarkable performance. The proposed system has been demonstrated to be valid for sortlisting a given data set of initial candidates (in 62,5% of the cases the positive one is ranked in the first position) and to serve as an exclusion method (97,4% and 96% of true negatives in training and test, respectively)

Hierarchical information fusion for decision making in craniofacial superimposition

Craniofacial superimposition is one of the most important skeleton-based identification methods. The process studies the possible correspondence between a found skull and a candidate (missing person) through the superimposition of the former over a variable number of images of the face of the latter. Within craniofacial superimposition we identified three different stages, namely: (1) image acquisition-processing and landmark location; (2) skull-face overlay; and (3) decision making. While we have already proposed and validated an automatic skull-face overlay technique in previous works, the final identification stage, decision making, is still performed manually by the expert. This consists of the determination of the degree of support for the assertion that the skull and the ante-mortem image belong to the same person. This decision is made through the analysis of several criteria assessing the skull-face anatomical correspondence based on the resulting skull-face overlay. In this contribution, we present a hierarchical framework for information fusion to support the anthropologist expert in the decision making stage. The main goal is the automation of this stage based on the use of several skull-face anatomical criteria combined at different levels by means of fuzzy aggregation functions. We have implemented two different experiments for our framework. The first aims to obtain the most suitable aggregation functions for the system and the second validates the proposed framework as an identification system. We tested the framework with a dataset of 33 positive and 411 negative identification instances. The present proposal is the first automatic craniofacial superimposition decision support system evaluated in an objective and statistically meaningful way. © 2017 Elsevier B.V

Study on the criteria for assessing skull-face correspondence in craniofacial superimposition

Craniofacial superimposition has the potential to be used as an identification method when other traditional biological techniques are not applicable due to insufficient quality or absence of ante-mortem and post-mortem data. Despite having been used in many countries as a method of inclusion and exclusion for over a century it lacks standards. Thus, the purpose of this research is to provide forensic practitioners with standard criteria for analysing skull-face relationships. Thirty-seven experts from 16 different institutions participated in this study, which consisted of evaluating 65 criteria for assessing skull-face anatomical consistency on a sample of 24 different skull-face superimpositions. An unbiased statistical analysis established the most objective and discriminative criteria. Results did not show strong associations, however, important insights to address lack of standards were provided. In addition, a novel methodology for understanding and standardizing identification methods based on the observation of morphological patterns has been proposed

El registro sedimentario y faunístico de las cuencas de Calatayud-Daroca y Teruel. Evolución paleoambiental y paleoclimática durante el Neógeno

Las cuencas de Calatayud-Daroca y Teruel contienen un registro sedimentario y faunístico muy completo del Neógeno continental español. En ellas están definidas las, secciones tipo del Rambliense, Aragoniense, Turoliense y Alfambriense. A su vez, el Vallesiense se encuentra muy bien representado en la parte norte de la Cuenca de Teruel, tanto litoestratigráficamente como por la amplia sucesión de faunas de vertebrados que contiene. En este trabajo se presenta un resumen y puesta al día de la información estratigráfica y sedimentológica disponible sobre las formaciones neógenas de ambas cuencas, incluyendo además datos recientes sobre el límite Aragoniense-Vallesiense en el área de Daroca-Nombrevilla y sobre el registro sedimentario de edad Plioceno en la parte más septentrional de la región de Teruel-Alfambra. Se presenta asimismo un cuadro sintético de las columnas magnetoestratigráficas elaboradas en los últimos años. Con carácter preliminar, se muestran las curvas de evolución paleoclimática (humedad/temperatura) deducibles de las asociaciones de micromamíferos presentes en una densa sucesión de yacimientos que abarcan todo el Mioceno. Las diferencias en los resultados obtenidos sobre la evolución paleoclimática de ambas cuencas son posiblemente debidas a la distinta metodología utilizada en el análisis de las asociaciones faunísticas. Por otra parte, se discuten las faltas de ajuste detectadas, al menos para algunos intervalos temporales, entre los resultados deducibles de este tipo de interpretación paleoclimática y los que se derivan del análisis sedimentológico de los depósitos.The Calatayud-Daroca and Teruel basins (NE Spain) show a very complete sedimentary and faunal record of the Spanish continental Neogene. The stratotypes for the Ramblian, Aragonian, Turolian and Alfambrian stages have been defined in these basins. Moreover, the Vallesian is well recorded especially in the northern Teruel Basin. This paper gives a state-of-the-art summary of the available information generated in the latest years by detailed sedimentological, biostratigraphical and magnetostratigraphical studies of the Neogene deposits of the basins. Recent results concerning the Aragonian-Vallesian boundary in the Daroca-Nombrevilla area are presented. A general integrated scheme of the magnetostratigraphic logs obtained from a large number of stratigraphic sections throughout the region is also included. Preliminary palaeoclimatic evolutionary curves (humidity/ temperature) are proposed for the Miocene stratigraphic record of the basins. The curves have been inferred from detailed analysis of the micromammal associations found in an extremely dense succession of mammal localities. Differences in the palaeoclimatic curves proposed for Calatayud-Daroca and Teruel may be explained by the use of different methodologies. Discrepancies between sedimentological and faunal based interpretations of the palaeoclimatic evolution of some intervals of the Miocene are discussed

Effect of infill pattern in Fused Filament Fabrication (FFF) 3D Printing on materials performance

Fused Filament Fabrication (FFF) is an Additive Manufacturing process popularized in the last decade due to its easiness of use and lower costs. However, despite its increasing popularity, the process itself has several gaps in knowledge, hindering further uses on more advanced objects. Also, the freedom of design allows significant variances in the printed parts, many influencing production and mechanical properties. This work studies the influences of the infill patterns in the mechanical response of printed parts. Using poly (lactic acid) (PLA), a widely used polymer in FFF process, the mechanical responses of parts printed with different infill patterns were analyzed. Rectilinear, Honeycomb, Triangle and Grid patterns were tested on impact resistance and tensile strength. Additionally, samples masses were measured and compared to the mechanical response. Results shown significant differences in the on tested properties. Tensile strength varied from 2.4 to 1.1 MPa, and impact resistance from 3.8 to 1.5 kJ/m² Also, measured mass was found to be significantly higher on the Honeycomb pattern. Considering mechanical response from both tensile and impact tests along with printed mass, Rectilinear pattern can be considered the most advantageous from the economic point of view