Repeatable semantic reef-mapping through photogrammetry and label-augmentation

In an endeavor to study natural systems at multiple spatial and taxonomic resolutions, there is an urgent need for automated, high-throughput frameworks that can handle plethora of information. The coalescence of remote-sensing, computer-vision, and deep-learning elicits a new era in ecological research. However, in complex systems, such as marine-benthic habitats, key ecological processes still remain enigmatic due to the lack of cross-scale automated approaches (mms to kms) for community structure analysis. We address this gap by working towards scalable and comprehensive photogrammetric surveys, tackling the profound challenges of full semantic segmentation and 3D grid definition. Full semantic segmentation (where every pixel is classified) is extremely labour-intensive and difficult to achieve using manual labeling. We propose using label-augmentation, i.e., propagation of sparse manual labels, to accelerate the task of full segmentation of photomosaics. Photomosaics are synthetic images generated from a projected point-of-view of a 3D model. In the lack of navigation sensors (e.g., a diver-held camera), it is difficult to repeatably determine the slope-angle of a 3D map. We show this is especially important in complex topographical settings, prevalent in coral-reefs. Specifically, we evaluate our approach on benthic habitats, in three different environments in the challenging underwater domain. Our approach for label-augmentation shows human-level accuracy in full segmentation of photomosaics using labeling as sparse as 0.1%, evaluated on several ecological measures. Moreover, we found that grid definition using a leveler improves the consistency in community-metrics obtained due to occlusions and topology (angle and distance between objects), and that we were able to standardise the 3D transformation with two percent error in size measurements. By significantly easing the annotation process for full segmentation and standardizing the 3D grid definition we present a semantic mapping methodology enabling change-detection, which is practical, swift, and cost-effective. Our workflow enables repeatable surveys without permanent markers and specialized mapping gear, useful for research and monitoring, and our code is available online. Additionally, we release the Benthos data-set, fully manually labeled photomosaics from three oceanic environments with over 4500 segmented objects useful for research in computer-vision and marine ecology

Numerical analysis for design of bioinspired ceramic modular armors for ballistic protections

[EN] The exigent requirements for personal protections in terms of energy absorption and ergonomics have led to increasing interest in bioinspired protections. This work focuses on the numerical analysis of ballistic behavior of different bioinspired geometries under impact loadings. Ceramic armors based on ganoid fish scales (the type exhibited by gars, bichirs and reedfishes), placoid fish scales (characterizing sharks and rays) and armadillo natural protection have been considered. Different impact conditions are studied, including perpendicular and oblique impacts to surface protection, different yaw angle, and multiple impacts. Main conclusion is related to the improved efficiency of modular armors against multiple shots exhibiting more localized damage and crack arrest properties. Moreover, its potential ergonomic is a promising characteristic justifying a deeper study.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work has been carried out within the framework of the research program Juan de la Cierva Incorporacion 2015, and research projects DPI2017-88166-R, and RTC-2015-3887-8 of FEDER program financed by the Ministerio de Economia, Industria y Competitividad of Spain. The support of the Generalitat Valenciana, Programme PROMETEO 2016/007 is also acknowledged.González Albuixech, VF.; Rodríguez-Millán, M.; Ito, T.; Loya, JA.; Miguélez, MH. (2019). Numerical analysis for design of bioinspired ceramic modular armors for ballistic protections. International Journal of Damage Mechanics. 28(6):815-837. https://doi.org/10.1177/1056789518795203S815837286Chen, I. H., Kiang, J. H., Correa, V., Lopez, M. I., Chen, P.-Y., McKittrick, J., & Meyers, M. A. (2011). Armadillo armor: Mechanical testing and micro-structural evaluation. Journal of the Mechanical Behavior of Biomedical Materials, 4(5), 713-722. doi:10.1016/j.jmbbm.2010.12.013Chintapalli, R. K., Mirkhalaf, M., Dastjerdi, A. K., & Barthelat, F. (2014). Fabrication, testing and modeling of a new flexible armor inspired from natural fish scales and osteoderms. Bioinspiration & Biomimetics, 9(3), 036005. doi:10.1088/1748-3182/9/3/036005Deka, L. J., Bartus, S. D., & Vaidya, U. K. (2009). Multi-site impact response of S2-glass/epoxy composite laminates. Composites Science and Technology, 69(6), 725-735. doi:10.1016/j.compscitech.2008.03.002Duro-Royo, J., Zolotovsky, K., Mogas-Soldevila, L., Varshney, S., Oxman, N., Boyce, M. C., & Ortiz, C. (2015). MetaMesh: A hierarchical computational model for design and fabrication of biomimetic armored surfaces. Computer-Aided Design, 60, 14-27. doi:10.1016/j.cad.2014.05.005Flores-Johnson, E. A., Shen, L., Guiamatsia, I., & Nguyen, G. D. (2014). Numerical investigation of the impact behaviour of bioinspired nacre-like aluminium composite plates. Composites Science and Technology, 96, 13-22. doi:10.1016/j.compscitech.2014.03.001Grujicic, M., Pandurangan, B., & Coutris, N. (2011). A Computational Investigation of the Multi-Hit Ballistic-Protection Performance of Laminated Transparent-armor Systems. Journal of Materials Engineering and Performance, 21(6), 837-848. doi:10.1007/s11665-011-0004-3Grunenfelder, L. K., Suksangpanya, N., Salinas, C., Milliron, G., Yaraghi, N., Herrera, S., … Kisailus, D. (2014). Bio-inspired impact-resistant composites. Acta Biomaterialia, 10(9), 3997-4008. doi:10.1016/j.actbio.2014.03.022Klasztorny, M., & Świerczewski, M. (2015). NUMERICAL MODELLING AND VALIDATION OF 12.7 MM FSP IMPACT INTO ALFC SHIELD – ARMOX 500T STEEL PLATE SYSTEM. Journal of KONES. Powertrain and Transport, 19(4), 291-299. doi:10.5604/12314005.1138463Liu, P., Zhu, D., Yao, Y., Wang, J., & Bui, T. Q. (2016). Numerical simulation of ballistic impact behavior of bio-inspired scale-like protection system. Materials & Design, 99, 201-210. doi:10.1016/j.matdes.2016.03.040Morka, A., & Nowak, J. (2015). NUMERICAL ANALYSES OF CERAMIC/METAL BALLISTIC PANELS SUBJECTED TO PROJECTILE IMPACT. Journal of KONES. Powertrain and Transport, 19(4), 465-472. doi:10.5604/12314005.1138618Pandya, K., Kumar, C. V. S., Nair, N., Patil, P., & Naik, N. (2014). Analytical and experimental studies on ballistic impact behavior of 2D woven fabric composites. International Journal of Damage Mechanics, 24(4), 471-511. doi:10.1177/1056789514531440Poniżnik, Z., Nowak, Z., & Basista, M. (2015). Numerical modeling of deformation and fracture of reinforcing fibers in ceramic–metal composites. International Journal of Damage Mechanics, 26(5), 711-734. doi:10.1177/1056789515611945Porter, M. M., Ravikumar, N., Barthelat, F., & Martini, R. (2017). 3D-printing and mechanics of bio-inspired articulated and multi-material structures. Journal of the Mechanical Behavior of Biomedical Materials, 73, 114-126. doi:10.1016/j.jmbbm.2016.12.016Reaugh, J. E., Holt, A. C., Welkins, M. L., Cunningham, B. J., Hord, B. L., & Kusubov, A. S. (1999). Impact studies of five ceramic materials and pyrex. International Journal of Impact Engineering, 23(1), 771-782. doi:10.1016/s0734-743x(99)00121-9Rostamiyan, Y., & Ferasat, A. (2016). High-speed impact and mechanical strength of ZrO2/polycarbonate nanocomposite. International Journal of Damage Mechanics, 26(7), 989-1002. doi:10.1177/1056789516644312Russell, B. P. (2014). Multi-hit ballistic damage characterisation of 304 stainless steel plates with finite elements. Materials & Design, 58, 252-264. doi:10.1016/j.matdes.2014.01.074Serjouei, A., Chi, R., Sridhar, I., & Tan, G. E. B. (2015). Empirical Ballistic Limit Velocity Model for Bi-Layer Ceramic–Metal Armor. International Journal of Protective Structures, 6(3), 509-527. doi:10.1260/2041-4196.6.3.509Shaktivesh, Nair, N., & Naik, N. (2014). Ballistic impact behavior of 2D plain weave fabric targets with multiple layers: Analytical formulation. International Journal of Damage Mechanics, 24(1), 116-150. doi:10.1177/1056789514524074Yang, W., Chen, I. H., Gludovatz, B., Zimmermann, E. A., Ritchie, R. O., & Meyers, M. A. (2012). Natural Flexible Dermal Armor. Advanced Materials, 25(1), 31-48. doi:10.1002/adma.20120271

Improving the light collection efficiency of silicon photomultipliers through the use of metalenses

Metalenses are optical devices that implement nanostructures as phase shifters to focus incident light. Their compactness and simple fabrication make them a potential cost-effective solution for increasing light collection efficiency in particle detectors with limited photosensitive area coverage. Here we report on the characterization and performance of metalenses in increasing the light collection efficiency of silicon photomultipliers (SiPM) of various sizes using an LED of 630 nm, and find a six to seven-fold increase in signal for a 1.3×1.3 mm² SiPM when coupled with a 10-mm-diameter metalens manufactured using deep ultraviolet stepper lithography. Such improvements could be valuable for future generations of particle detectors, particularly those employed in rare-event searches such as dark matter and neutrinoless double beta decay

The ubiquitous ζ\zeta-function and some of its "usual" and "unusual" meromorphic properties

In this contribution we announce a complete classification and new exotic phenomena of the meromorphic structure of \z-functions associated to conic manifolds proved in \cite{KLP1}. In particular, we show that the meromorphic extensions of these \z-functions have, in general, countably many logarithmic branch cuts on the nonpositive real axis and unusual locations of poles with arbitrarily large multiplicity. Moreover, we give a precise algebraic-combinatorial formula to compute the coefficients of the leading order terms of the singularities.Comment: Paper presented at the 8th Workshop on Quantum Field Theory under the Influence of External Conditions (Leipzig, Germany, 16-21 September, 2007

Coral Disease Diagnostics: What's between a Plague and a Band?

Recently, reports of coral disease have increased significantly across the world's tropical oceans. Despite increasing efforts to understand the changing incidence of coral disease, very few primary pathogens have been identified, and most studies remain dependent on the external appearance of corals for diagnosis. Given this situation, our current understanding of coral disease and the progression and underlying causes thereof is very limited. In the present study, we use structural and microbial studies to differentiate different forms of black band disease: atypical black band disease and typical black band disease. Atypical black band diseased corals were infected with the black band disease microbial consortium yet did not show any of the typical external signs of black band disease based on macroscopic observations. In previous studies, these examples, here referred to as atypical black band disease, would have not been correctly diagnosed. We also differentiate white syndrome from white diseases on the basis of tissue structure and the presence/absence of microbial associates. White diseases are those with dense bacterial communities associated with lesions of symbiont loss and/or extensive necrosis of tissues, while white syndromes are characteristically bacterium free, with evidence for extensive programmed cell death/apoptosis associated with the lesion and the adjacent tissues. The pathology of coral disease as a whole requires further investigation. This study emphasizes the importance of going beyond the external macroscopic signs of coral disease for accurate disease diagnosis

Vacuum Expectation Value of the Spinor Massive field in the Cosmic String Space-Time

We found the contribution to the vacuum expectation value of the energy-momentum tensor of a massive Dirac field due to the conical geometry of the cosmic string space-time. The heat kernel and heat kernel expansion for the squared Dirac operator in this background are also considered and the first three coefficients were found in an explicity form.Comment: 9 pages, 1 figure (2 ref added) (enlarged version

Development and Manufacture of Cost Effective Composite Drill Pipe

This technical report presents the engineering research, process development and data accomplishments that have transpired to date in support of the development of Cost Effective Composite Drill Pipe (CDP). The report presents progress made from October 1, 2004 through September 30, 2005 and contains the following discussions: (1) Qualification Testing; (2) Prototype Development and Testing of ''Smart Design'' Configuration; (3) Field Test Demonstration; and (4) Commercial order for SR-CDP from Torch International. The objective of this contract is to develop and demonstrate ''cost effective'' Composite Drill Pipe. It is projected that this drill pipe will weigh less than half of its steel counter part. The resultant weight reduction will provide enabling technology that will increase the lateral distance that can be reached from an offshore drilling platform and the depth of water in which drilling and production operations can be carried out. Further, composite drill pipe has the capability to carry real time signal and power transmission within the pipe walls. CDP can also accommodate much shorter drilling radius than is possible with metal drill pipe. As secondary benefits, the lighter weight drill pipe can increase the storage capability of floating off shore drilling platforms and provide substantial operational cost savings

Regularity of the eta function on manifolds with cusps

On a spin manifold with conformal cusps, we prove under an invertibility condition at infinity that the eta function of the twisted Dirac operator has at most simple poles and is regular at the origin. For hyperbolic manifolds of finite volume, the eta function of the Dirac operator twisted by any homogeneous vector bundle is shown to be entire.Comment: 22 pages, 2 figure

Análisis numérico de blindajes cerámicos modulares inspirados en la naturaleza para protecciones balísticas

Comunicación presentada en el XXXIV Encuentro del Grupo Español de Fractura celebrado en Santander del 29 al 31 de marzo de 2017.The requirements increase of the protections used by the security forces, which should combine a high capacity for protection and ergonomics, have determined an interest on bioinspired protections. This work presents a numericalstudy numerical of its role performance against impact. We have considered ceramic armours based on ganoid fishscales (gars, bichirs and reedfishes), placoid fish scales (sharks and rays) and armadillos. Perpendicular impacts tosurface protection, oblique and double impacts are considered. It is concluded that the localized damaging and crack arrest properties, associated with its modular configuration, improve their efficiency on multihit situations, besides itspotential ergonomic, convert them in suitable candidates for a deeper study.El aumento en los requerimientos de las protecciones que emplean las fuerzas de seguridad, que deben combinar una alta capacidad de protección y de ergonomía han determinado un creciente interés por el estudio y diseño de protecciones inspiradas en la naturaleza. En este trabajo, se presenta un estudio numérico de la respuesta ante impacto que presentan blindajes cerámicos inspirados en escamas tipo ganoide (esturiones y bichires) y placoide (tiburones y rayas) y la protección de los armadillos. Se consideran impactos perpendiculares a la superficie de protección, oblicuos e impactos dobles. Se concluye que las propiedades de limitar el daño y la fractura asociada a su configuración modular, mejoran su eficacia ante sucesivos impactos, lo que unido a su potencial ergonómico las convierten en candidatas para un estudio más profundo.Los autores desean agradecer, por el soporte económico, al trabajo al programa Juan de la Cierva Incorporación 2015, IJCI-2015-23245 y al proyecto RTC-2015-3887-8 del programa FEDER del Ministerio de Economía, Industria y Competitividad de España