Politecnio die Bari - Catalogo di prodotti della Ricerca
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Efficient FPGA-Accelerated Convolutional Neural Networks for Cloud Detection on CubeSats
No full textWe present the implementation of four FPGA-accelerated convolutional neural network (CNN) models for onboard cloud detection in resource-constrained CubeSat missions, leveraging Xilinx's Vitis AI (VAI) framework and Deep Learning Processing Unit (DPU), a programmable engine with pre-implemented, parameterizable IP cores optimized for deep neural networks, on a Zynq UltraScale+ MPSoC. This study explores both pixel-wise (Pixel-Net and Kernel-Net) and image-wise (U-Net and Patch-Net) models to benchmark trade-offs in accuracy, latency, and model complexity. Applying channel pruning, we achieved substantial reductions in model parameters (up to 98.6%) and floating-point operations (up to 90.7%) with minimal accuracy loss. Furthermore, the VAI tool was used to quantize the models to 8-bit precision, ensuring optimized hardware performance with negligible impact on accuracy. All models retained high accuracy post-FPGA integration, with a cumulative maximum accuracy drop of only 0.6% after quantization and pruning. The image-wise Patch-Net and U-Net models demonstrated strong real-time inference capabilities, achieving frame rates per second of 57.14 and 37.45, respectively, with power consumption of around 2.5 W, surpassing state-of-the-art onboard cloud detection solutions. Our approach underscores the potential of DPU-based hardware accelerators to expand the processing capabilities of small satellites, enabling efficient and flexible onboard CNN-based applications
Remote meta-selective C-H bromination of arenes using a recyclable Ru-based aminopropyl bifunctional PMO with robust imidazolium bridges
No full textThis systematic study delves into the synthesis and characterization of robust bi-functional aminopropyl-tagged periodic mesoporous organosilica with a high loading of small imidazolium bridges in its framework (PrNH2@R-PMO-IL, ∼2 mmol g−1 of IL). The materials proved to be a reliable and enduring support for the immobilization of Ru species, demonstrating strong performance and excellent selectivity in the meta-bromination of various derivatives of 2-phenylpyridine compounds and other heterocycles, showcasing its effectiveness and robust nature. The synthesized materials were thoroughly characterized to determine their structural properties, such as pore size distribution, loading of organic groups, and surface area, using various analytical techniques. The research aims to improve the catalytic activity of supported ruthenium species in meta-selective bromination reactions through a systematic approach that emphasizes the synergistic effects of the mesoporous structure, concentration of imidazolium incorporated, and aminopropyl functionalization for enhancing the catalytic performance of the supported Ru species in these reactions. Our findings indicate that the developed catalyst system exhibits promise as a recyclable catalyst for meta-C-H activation, offering the potential for multiple reaction cycles and reduced waste production. This study highlights the enhanced catalytic performance and versatility of Ru@PrNH2@R-PMO-IL in comparison with previously documented homogeneous and heterogeneous catalyst systems, even when using lower loading levels. This is particularly evident in meta-C-H bromination of challenging substrates, such as 1-phenylpyrazole for the first time under the described catalytic chemical reaction
Shifting Lithium Amide Reactivity to the Radical Domain: Regioselective Radical C−H Functionalization of 3-Iodooxetane for the Synthesis of 1,5-Dioxaspiro[2.3]hexanes
No full textStrained spiro-heterocycles (SSHs) have gained significant attention within the medicinal chemistry community as promising sp3-rich bioisosteres for their aromatic and non-spirocyclic counterparts. We herein report access to an unprecedented spiro-heterocycle—1,5-dioxaspiro[2.3]hexane. Our synthetic approach leverages a lithium-amide induced single-electron transfer to benzophenones generating an N-centered radical and a ketyl radical anion—reminiscent of a frustrated radical pair. This pair works synergistically to selectively abstract the β-hydrogen from 3-iodooxetane, initiating an exergonic radical-radical coupling reaction. This process enables the formation of the desired bond between the oxetane core and benzophenone derivatives, ultimately yielding the novel 1,5-dioxaspiro[2.3]hexane core. The stability and synthetic utility of the novel 1,5-dioxaspiro[2.3]hexane motif are showcased. An in-depth mechanistic investigation is presented, including cyclic voltammetry studies, as well as computational calculations and experiments to support the mechanism of this new single electron synthetic tactic
La contrazione urbana. Strategie di rightsizing per la città post-growth
Full text linkLa città vive oggi il passaggio da una fase di espansione e crescita a una di stasi o
decrescita in buona parte dei contesti urbani dei Paesi economicamente sviluppati.
In un periodo storico in cui la transizione – ecologica, energetica, digitale, economica,
demografica, ... – è quotidianamente al centro del dibattito pubblico, la città
contemporanea ne vive un’altra, connessa al fenomeno della contrazione urbana,
innescatasi all’inizio del secolo a causa della crisi economica e demografica, che sta
profondamente modificando forme e usi consolidati della città. Ciò pone la necessità
di costruire conoscenza su doppia scala – globale e nazionale – su un tema spesso
trascurato o non riconosciuto dai territori e ripensare l’assetto del territorio postgrowth
rispetto ai mutati bisogni della società.
Ma come si interviene nel mondo sulle shrinking city? Come si agisce, invece, in
contesti come quello italiano dove i ‘sintomi’ di questa condizione urbana si fanno
così silenziosi da ritardarne il riconoscimento?
La complessità e diversificazione del fenomeno, congiunta con l’inerzia al cambiamento
radicata nei processi e negli strumenti di pianificazione nostrani, richiede di inquadrare
differenti modalità di intervento nelle città in contrazione, non dimenticando le
specificità di ciascun territorio, che richiedono una riflessione ad hoc.
In questo senso studi e ricerche nell’ambito del righsizing – il processo di portare le
shrinking cities a una ‘giusta’ dimensione, proporzionata alla capacità di autosostenersi
e autoalimentarsi – pur nella diversità di approcci e obiettivi, pongono le basi per
sviluppare strategie per agire sui territori in contrazione. La ricerca approfondisce
alcune ‘posture’ di intervento sulla città come risposta al fenomeno dello urban
shrinkage, tuttavia l’aleatorietà delle manifestazioni materiali e immateriali di un
fenomeno come quello della contrazione urbana e l’inadeguatezza degli ‘attrezzi’ di
quanti si trovano chiamati a lavorare sulla città in perdita, portano a individuare nella
pianificazione e in particolar modo nella flessibilità degli strumenti urbanistici la più
adeguata risposta strutturale a questo tipo di condizione. In questo alveo, la ricerca
prova ad approfondire nel suo ultimo punto il concetto di reversibilità delle previsioni
urbanistiche nella pianificazione attraverso alcune esperienze italiane in corso.Cities are experiencing a transition from a phase of expansion and growth to one of
stagnation, or decline, in most of urban settings in economically developed countries.
At a time in history when transition – ecological, energetic, digital, economic,
demographic, ... – is at the center of public debate on a daily basis, the contemporary
city is also experiencing a different one which is thoroughly changing established
forms and uses of the city. The current urban transition appears to be strongly related
to the urban shrinkage phenomenon, triggered at the beginning of the century by the
economic and demographic crisis. This poses the necessity to build knowledge on a
double scale – both global and local – about an issue often neglected or unrecognized
by territories, and to rethink post-growth spatial planning, according to society’s
changing needs and demands.
However, how do we cope with shrinking cities across the world? On the other hand,
how do we operate in contexts, as Italy, where the ‘symptoms’ of this urban condition
become silent enough to delay its acknowledgement?
The complexity and diversification of the phenomenon, combined with changes
inertia rooted in domestic planning processes and tools, requires framing different
approaches towards shrinking cities, keeping in mind each territory’s specificities,
which demand specific considerations.
As such, studies and research in the field of rightsizing – the process of bringing
shrinking cities to the ‘right’ size, according to their ability to self-sustain and self-
support – lay the basis for developing strategies to operate on shrinking territories,
despite different approaches and objectives. This research explores some ‘postures’
of action on the city as a response to the urban shrinkage. However, the aleatory
nature of material and immaterial manifestations of such a phenomenon, together
with the inadequate ‘toolkit’ of those challenged to work on shrinking cities, lead
to identify urban planning and in particular its flexibility in planning tools as the
most appropriate structural response to such a condition. Within this framework, the
research tries to explore in its final point the reversibility of urban planning through
some ongoing Italian experiences
Metasurface-Enabled Microphotonic Biosensors via BIC Modes
Full text linkPhotonic biosensors based on bound states in the continuum (BIC) resonant modes exhibit a transformative potential for high-sensitivity, label-free detection across various diagnostic applications. BIC-enabled metasurfaces, utilizing dielectric, plasmonic, and hybrid structures, achieve ultra-high Q-factors and amplify target molecule interactions on functionalized sensor surfaces. These unique properties result in increased refractive index sensitivity and low detection limits, essential for monitoring biomolecules in clinical diagnostics, environmental analysis, and food safety. Recent advancements in BIC-enabled metasurfaces have demonstrated ultra-low detection limits in the zeptomolar range, making these devices highly promising for real-world applications. This review paper critically discusses the design principles of BIC-based biosensors, emphasizing key factors such as material selection, structural asymmetry, and functionalization strategies that enhance both sensitivity and specificity. Additionally, recent advancements in fabrication techniques that enable precise BIC control with scalable approaches for practical biosensing applications are examined. Case studies demonstrate the effectiveness of BIC metasurfaces for real-time, low-concentration detection, highlighting their versatility and adaptability. Finally, the review discusses future challenges and opportunities, such as integration with microfluidics for point-of-care testing and multiplexed sensing, underscoring the potential of BIC-based platforms to revolutionize the field of biosensing
Opening the black box of Growth Hacking: Insights into the microfoundations of Lean Startup Capabilities
Full text linkGrowth hacking (GH) is a strategy of rapid experimentation and testing aimed at scaling firms’ business model. Based on the relationships established in the literature between GH and Lean Startup (LS), we acknowledge LS capabilities play a crucial role in the successful implementation of GH, yet a deeper understanding of how LS capabilities support GH is needed, especially from a theoretical perspective. In this context, through a multiple case study approach analyzing six different startups, we aim to unveil the microfoundations of LS capabilities supporting the implementation of GH, hence opening the black box of GH. This research advances the theoretical development and understanding of GH, with a focus on its relationship with LS and underlying LS capabilities, by leveraging the microfoundations perspective to reconcile theory and practice when examining GH. Additionally, it informs the debate on how GH can create favorable conditions for scaling business models
Deep Autoencoder Framework for Classifying Damage Mechanisms in Repaired CFRP
No full textThis study investigates the classification of damage modes in adhesively bonded carbon fiber-reinforced plastic (CFRP) composites, a critical factor in advancing lightweight automotive design. Adhesive bonding, replacing traditional riveting, improves structural integrity while reducing weight and CO2 emissions. Mechanical testing on CFRP composites was performed, and acoustic emission (AE) signals were collected to evaluate damage mechanisms. A deep autoencoder (DAE) framework was developed to automate damage characterization by reducing AE signal dimensionality through singular value decomposition (SVD) and classifying features using the k-means algorithm. This approach effectively identified three primary damage modes: matrix cracking, interfacial debonding, and fiber breakage. Traditional AE features, such as entropy and amplitude were also classified and validated using spectral analysis. The DAE-based strategy demonstrated superior capability in real-time damage mode differentiation. Fractographic analysis confirmed crack growth in the adhesive layer, leading to interfacial debonding, fiber-matrix separation, and eventual fiber rupture. These findings highlight the DAE framework’s effectiveness in enhancing damage mode characterization, offering valuable insights for optimizing the structural performance of bonded CFRP composites in automotive applications
Measurement of multidifferential cross sections for dijet production in proton–proton collisions at
No full text: A measurement of the dijet production cross section is reported based on proton-proton collision data collected in 2016 at s=13TeV by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of up to 36.3 fb-1 . Jets are reconstructed with the anti- kT algorithm for distance parameters of R=0.4 and 0.8. Cross sections are measured double-differentially (2D) as a function of the largest absolute rapidity |y|max of the two jets with the highest transverse momenta pT and their invariant mass m1,2 , and triple-differentially (3D) as a function of the rapidity separation y∗ , the total boost yb , and either m1,2 or the average pT of the two jets. The cross sections are unfolded to correct for detector effects and are compared with fixed-order calculations derived at next-to-next-to-leading order in perturbative quantum chromodynamics. The impact of the measurements on the parton distribution functions and the strong coupling constant at the mass of the Z boson is investigated, yielding a value of αS(mZ)=0.1179±0.0019
Planetary construction with ISRU on Moon and Mars: Scalability and automation of the construction processes
Full text linkHuman exploration of the heliosphere (and beyond) is closely related to the development of the capability to use local resources.
Despite the trend that sees a progressive growth in the useful payload of the new generation carriers, establishing a constant human presence and growth in the volumes of buildings on the lunar and martian surface will be possible only through mastery in the use of materials offered by the surrounding environment. Building on (or below) the surface requires a deep knowledge not only of the properties of materials and construction techniques but also of the form factor of pressurized and non-pressurized constructions. The environmental conditions (and properties of the regolith) between the moon and Mars, although very different, characterize the need to automate the construction processes right from the exploration phase. This research aims to analyze the construction techniques of terrestrial and space structures to define an abacus of techniques and technologies for the efficient use of resources in situ, to structure a methodology of approach to the design of structures suitable for welcoming human crews on the lunar and Martian surface. and finally to validate the form factor of these structures through numerical techniques (FEM) and prototyping (AM) with the use of simulants. In the same way, this work will address the research gap in the current research, identified in four main topics:
Scalability of extraterrestrial manufacturing and construction techniques
Preservation strategies against environmental dangers for the mechanical equipment needed for the construction
Reliability of the use of simulants and space environment conditions replication in earth-based testing.
Robustness of automation protocols to enable autonomous construction
Those four research gaps, assumed from the most up-to-date literature analysis, are a central research topic to enable the continuation of the research on construction form factor and automation. Since reproducing manufacturing construction element manufacturing with all the different techniques considered would be extremely expensive in terms of time and resources, the analysis will mostly rely on scientific literature and results from previous testing. The scalability of the construction techniques will be assessed similarly, and testing will be conducted through simulations (FEA) and field testing at reduced scale