Radar/electro-optical data fusion for non-cooperative UAS sense and avoid

Abstract This paper focuses on hardware/software implementation and flight results relevant to a multi-sensor obstacle detection and tracking system based on radar/electro-optical (EO) data fusion. The sensing system was installed onboard an optionally piloted very light aircraft (VLA). Test flights with a single intruder plane of the same class were carried out to evaluate the level of achievable situational awareness and the capability to support autonomous collision avoidance. System architecture is presented and special emphasis is given to adopted solutions regarding real time integration of sensors and navigation measurements and high accuracy estimation of sensors alignment. On the basis of Global Positioning System (GPS) navigation data gathered simultaneously with multi-sensor tracking flight experiments, potential of radar/EO fusion is compared with standalone radar tracking. Flight results demonstrate a significant improvement of collision detection performance, mostly due to the change in angular rate estimation accuracy, and confirm data fusion effectiveness for facing EO detection issues. Relative sensors alignment, performance of the navigation unit, and cross-sensor cueing are found to be key factors to fully exploit the potential of multi-sensor architectures

Particle Filtering for Obstacle Tracking in UAS Sense and Avoid Applications

Obstacle detection and tracking is a key function for UAS sense and avoid applications. In fact, obstacles in the flight path must be detected and tracked in an accurate and timely manner in order to execute a collision avoidance maneuver in case of collision threat. The most important parameter for the assessment of a collision risk is the Distance at Closest Point of Approach, that is, the predicted minimum distance between own aircraft and intruder for assigned current position and speed. Since assessed methodologies can cause some loss of accuracy due to nonlinearities, advanced filtering methodologies, such as particle filters, can provide more accurate estimates of the target state in case of nonlinear problems, thus improving system performance in terms of collision risk estimation. The paper focuses on algorithm development and performance evaluation for an obstacle tracking system based on a particle filter. The particle filter algorithm was tested in off-line simulations based on data gathered during flight tests. In particular, radar-based tracking was considered in order to evaluate the impact of particle filtering in a single sensor framework. The analysis shows some accuracy improvements in the estimation of Distance at Closest Point of Approach, thus reducing the delay in collision detection

Differential Expression of Kisspeptin System and Kisspeptin Receptor Trafficking during Spermatozoa Transit in the Epididymis

The hypothalamus–pituitary–testis axis controls the production of spermatozoa, and the kisspeptin system, comprising Kiss1 and Kiss1 receptor (Kiss1R), is the main central gatekeeper. The activity of the kisspeptin system also occurs in testis and spermatozoa, but currently the need of peripheral kisspeptin to produce gametes is not fully understood. Hence, we characterized kisspeptin system in rat spermatozoa and epididymis caput and cauda and analyzed the possible presence of Kiss1 in the epididymal fluid. The presence of Kiss1 and Kiss1R in spermatozoa collected from epididymis caput and cauda was evaluated by Western blot; significant high Kiss1 levels in the caput (p < 0.001 vs. cauda) and constant levels of Kiss1R proteins were observed. Immunofluorescence analysis revealed that the localization of Kiss1R in sperm head shifts from the posterior region in the epididymis caput to perforatorium in the epididymis cauda. In spermatozoa-free epididymis, Western blot revealed higher expression of Kiss1 and Kiss1R in caput (p < 0.05 vs. cauda). Moreover, immunohistochemistry revealed that Kiss1 and Kiss1R proteins were mainly localized in the secretory epithelial cell types and in contractile myoid cells, respectively. Finally, both dot blot and Elisa revealed the presence of Kiss1 in the epididymal fluid collected from epididymis cauda and caput, indicating that rat epididymis and spermatozoa possess a complete kisspeptin system. In conclusion, we reported for the first time in rodents Kiss1R trafficking in spermatozoa during the epididymis transit and Kiss1 measure in the epididymal fluid, thus suggesting a possible role for the system in spermatozoa maturation and storage within the epididymis

Las prácticas de cooperación en el Sistema de Bibliotecas de la UBA

Elizalde, Elsa Elena. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFasano de Roig, Nora Maria. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFerrando, Claudia Eugenia. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; Argentin

Los catálogos colectivos de la Universidad de Buenos Aires : pasado, presente y futuro

Elizalde, Elsa Elena. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFasano de Roig, Nora María. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFerrando, Claudia Eugenia. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; Argentin

Strategies and Alliances into Action to Improve National Collaboration

The Italian NILDE network of libraries continues to grow through the use of the NILDE system and currently comprises more than 600 Italian librarians and about 10.000 registered end-users.The system allows to daily manage and to record all the Inter-Library-Loan (ILL) operations, with a high national coverage. This paper presents the NILDE network governance and evolution and the strategies that have been put into action to improve collaboration in resource sharing among the participants. These strategies include: &#8722; release of best practices and worst practices; &#8722; activities to promote the knowledge about the network; &#8722; cooperation with the Italian national catalogs and consortia; &#8722; data analysis about ILL and its performance, related to: turn around time, reciprocity factor, requested/supplied documents imbalance analysis, analysis of ILL requested serial titles and their relationship with consortial e-only acquisitions. The availability of such a high volume of ILL data has allowed for the first time to analyze the trends and gaps of ILL and to help future cooperative acquisitions planning

Los catálogos colectivos de la Universidad de Buenos Aires : el mismo espíritu de cooperación en un nuevo ambiente tecnológico

Elizalde, Elsa Elena. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFasano de Roig, Nora María. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaFerrando, Claudia Eugenia. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; ArgentinaAlvarez Alonso, Pablo Alejandro. Universidad de Buenos Aires. Sistema de Bibliotecas y de Información; Argentin

The Rethinking Resource Sharing Initiative: the NILDE case study in the frame of Italian experiences

NILDE (Network for Inter-Library Document Exchange) is born at the CNR Bologna Research Area Library to provide an effective answer to the needs of libraries in order to guarantee information accessibility, sharing resources through Inter Library Loan (ILL) of returnable and non-returnable items (books and journal articles)

Multi-compartment analysis of the complex gradient-echo signal quantifies myelin breakdown in premanifest Huntington's disease

White matter (WM) alterations have been identified as a relevant pathological feature of Huntington’s disease (HD). Increasing evidence suggests that WM changes in this disorder are due to alterations in myelin‐associated biological processes. Multi-compartmental analysis of the complex gradient-echo MRI signal evolution in WM has been shown to quantify myelin in vivo, therefore pointing to the potential of this technique for the study of WM myelin changes in health and disease. This study first characterized the reproducibility of metrics derived from the complex multi-echo gradient-recalled echo (mGRE) signal across the corpus callosum in healthy participants, finding highest reproducibility in the posterior callosal segment. Subsequently, the same analysis pipeline was applied in this callosal region in a sample of premanifest HD patients (n = 19) and age, sex and education matched healthy controls (n = 21). In particular, we focused on two myelin-associated derivatives: i. the myelin water signal fraction (fm), a parameter dependent on myelin content; and ii. the difference in frequency between myelin and intra-axonal water pools (Δω), a parameter dependent on the ratio between the inner and the outer axonal radii. fm was found to be lower in HD patients (β = -0.13, p = 0.03), while Δω did not show a group effect. Performance in tests of working memory, executive function, social cognition and movement was also assessed, and a greater age-related decline in executive function was detected in HD patients (β = -0.06, p = 0.006), replicating previous evidence of executive dysfunction in HD. Finally, the correlation between fm, executive function, and proximity to disease onset was explored in patients, and a positive correlation between executive function and fm was detected (r = 0.542; p = 0.02). This study emphasises the potential of complex mGRE signal analysis for aiding understanding of HD pathogenesis and progression. Moreover, expanding on evidence from pathology and animal studies, it provides novel in vivo evidence supporting myelin breakdown as an early feature of HD

Body mass index and blood pressure in a semi-urban community in Ota, Nigeria

This study was designed to establish the relationship between body mass index (BMI) and blood pressure (BP) in an increasingly industrialised town in Nigeria due to the rising prevalence of hypertension in non-industrialised countries. Factors associated with BMI and BP levels were determined in three hundred adult male and female subjects in Ota community of Ogun State, Nigeria. The levels of the overweight among the male and female subjects were 53.03 % and 47.37 % respectively. The levels of hypertensive male and female subjects were 40.91 % and 35.34 % respectively. The overweight and underweight among the hypertensive male were 54.29 % and 0 % respectively; while the overweight and underweight among the hypertensive female were 42.86 % and 28.57 % respectively. Hypertension among the overweight, and hypotension among the underweight, are major health concern in Ota that requires intensive medical care