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Upgrade of the Belle II vertex detector with depleted monolithic CMOS active pixel sensors
No full textThe Belle II experiment at the SuperKEKB collider in Japan, which currently holds the world luminosity record for electron–positron collisions, plans to upgrade its vertex detector (VXD) to operate at a target luminosity of 6×1035 cm−2s−1. A new pixelated vertex detector (VTX) is under development, utilizing a monolithic CMOS pixel sensor named OBELIX (Optimized BELle II pIXel). The VTX design incorporates 5–6 layers with a total material budget below 2.5% X0. All layers will employ the OBELIX, adapted from the TJ-Monopix2 sensor initially designed for the ATLAS Inner Tracker (ITk) upgrade. The OBELIX sensor, designed using a 180 nm CMOS process, features an enhanced pixel matrix and additional functionalities compared to its predecessor. Laboratory tests and test beam characterization results on irradiated and unirradiated TJ-Monopix2 sensors have yielded promising results, confirming the key performance parameters for the OBELIX design. This paper reviews the overall design of the VTX and the OBELIX sensor and presents the latest results of the in-beam characterization of the TJ-Monopix2
Metric Error Assessment Regarding Geometric 3D Reconstruction of Transparent Surfaces via SfM Enhanced by 2D and 3D Gaussian Splatting
No full textThis research investigates the metric accuracy of 3D transparent object reconstruction, a task where conventional photogrammetry often fails. The topic is especially relevant in cultural heritage (CH), where accurate digital documentation of glass and transparent artifacts is important. The work proposes a practical methodology using existing tools to verify metric accuracy standards. The study compares three methods, conventional photogrammetry, 3D Gaussian splatting (3DGS), and 2D Gaussian splatting (2DGS), to assess their ability to produce complete and metrically reliable 3D models suitable for measurement and geometric analysis. A transparent glass artifact serves as the case study. Results show that 2DGS captures fine surface and internal details with better geometric consistency than 3DGS and photogrammetry. Although 3DGS offers high visual quality, it introduces surface artifacts that affect metric reliability. Photogrammetry fails to reconstruct the object entirely. The study highlights that visual quality does not ensure geometric accuracy, which is critical for measurement applications. In this work, ground truth comparisons confirm that 2DGS offers the best trade-off between accuracy and appearance, despite higher computational demands. These findings suggest extending the experimentation to other sets of images featuring transparent objects, and possibly also reflective ones
Magnetically Induced Skin Stretch Enhances Proprioceptive Feedback in Prosthetics
No full textProprioceptive feedback is essential for motor control and prosthetic embodiment, yet myoelectric prostheses lack naturalistic sensory input. Artificial skin stretch stimulation has emerged as a preferred method to convey proprioceptive cues, but current friction-based devices face limitations preventing integration into practical prostheses. This work investigates magnetically induced skin stretch as a non-invasive, potentially implantable alternative. We present MISS (Magnetically Induced Skin Stretch), a novel system that uses external coils to control magnets adhered to the skin, producing skin deformations that mimic subdermal implantation and evoke proprioceptive sensations. We conducted physical and psychophysical experiments, including Just Noticeable Difference and Point of Subjective Equality measurements. Eighteen participants, including five with transradial amputation, used the MISS device with a myoelectric prosthesis, where skin stretch was modulated in sync with prosthetic hand flexion. Results showed high object discrimination accuracy, with amputees performing comparably to non-disabled users. These findings demonstrate MISS as a promising proprioceptive feedback method, supporting its future integration into implantable systems
A Technique for the Study of the Volume and Textural Parameter Evolution of Marine Coarse Sediments
No full textIn this article, we detail a novel technique for measuring volume and textural parameters of coarse-grained marine sediments. The technique combines radio frequency identification (RFID) technology for sediment tracking with 3-D scanning for volume measurement. The technique is applied to real marine sediments collected from the beach under study. In the preliminary phase, the sediments are scanned using a low-cost 3-D scanning system and then fitted with an embedded RFID transponder, which allows their unambiguous identification. The pebbles are then deployed on the beach and, after a predefined period of time, they are located and retrieved by means of an ad-hoc RFID reader used as a detector. After retrieval, the pebbles are 3-D scanned to collect data on the volumetric changes that result from the abrasion and chipping processes caused by intergranular friction on their surfaces from water movements (mostly sea waves). The technique allows for an accurate estimation of morphological variations of sediments, thereby providing essential insights into sediment stability and, on a broader scale, coastal erosive processes. Moreover, it allows the study of the evolution of a number of textural parameters, such as sphericity or angularity, which can be extracted from the 3-D model
RESURVEYDUNE PROJECT: ASSESSING COASTAL DUNE CHANGES IN THE SAN ROSSORE ESTATE AND CALAMBRONE (TUSCANY, ITALY)
No full textIn 2023, a call for collaboration was sent to vegetation experts of the Italian Society of Vegetation Science (SISV) to join the ReSurveyDune project, aimed at resurveying Italian coastal dune areas [1]. In line with this objective, the present study resurveyed two coastal areas in northern Tuscany (Italy), within the province of Pisa. The first is located inside the Migliarino – San Rossore – Massaciuccoli Regional Park and includes a 12 km stretch of coastline between the Serchio River to the north and the Arno River to the south. The second area corresponds to the 3.5 km Calambrone coastline, which lies adjacent to the park and is subject to regulatory constraints. It is situated between Tirrenia and the mouth of the Scolmatore d’Arno. While the San Rossore coastline is closed to the public and severely threatened by coastal erosion, the Calambrone coastline is characterized by numerous bathing establishments and remains relatively stable [2].
In spring 2024, we resurveyed 23 historical plots in San Rossore [3] and 28 in Calambrone [4], following the same methodology used for the historical plots, namely the Braun-Blanquet phytosociological method. [A1.1][A1.2]The presence of all vascular plant species was recorded, and species abundance was visually estimated using the Braun-Blanquet percentage cover scale. Each relevé was assigned to a specific EU habitat type, as defined by the 92/43/EEC Habitats Directive, focusing on the following herbaceous habitats: 1210, 2110, 2120, 2210, and 2230. To analyze shifts in species richness and diversity over time, we calculated Hill numbers (the exponential of Shannon diversity and the inverse of Simpson diversity) for each habitat. Differences between habitats were assessed using the Wilcoxon rank sum test. Additionally, rank-abundance curves were constructed to illustrate the relative abundance of species within each habitat, allowing for temporal comparisons.
The resurvey revealed three key findings: (i) Species richness declined along the San Rossore coastline but showed a slight increase in Calambrone. (ii) The number of historical plots decreased, particularly for habitat 1210 (annual vegetation of drift lines), which disappeared in Calambrone and was reduced by half in San Rossore. (iii) While the dominant species in each habitat remained the same, their overall abundance significantly declined.
In conclusion, the study highlights an ongoing regression and fragmentation of dune habitats in both areas, driven by different threats: coastal erosion in San Rossore and human disturbance linked to tourism in Calambrone. In both cases, targeted conservation and management measures are urgently needed to mitigate the degradation of these environments, preserve biodiversity, and ensure the long-term sustainability of these coastal areas
Enhancing WiFi Privacy: A Focus on Frame Anonymization Techniques
No full textRecently, the WiFi community has focused on improving privacy measures, beginning with the introduction of randomized and changing MAC addresses (RCM) to mitigate privacy concerns during pre-association discovery (PAD) mechanisms. A significant advancement has been the establishment of the IEEE 802.11bi Task Group (TG), known as enhanced data privacy (EDP), which targets various aspects of privacy. Current EDP efforts concentrate on developing frame anonymization techniques to mitigate the issue of presence monitoring of associated STAs. This article provides an overview of these techniques, focusing on MAC address rotation schemes. Preliminary simulation results highlight the effectiveness of these schemes, although a dependency on the network scenario was observed. The performance analysis provides insights for future research to improve frame anonymization strategies
Constrained Riemannian Manifold Optimization for the Simultaneous Shaping of Ambiguity Function and Transmit Beampattern
No full textDesigning the transmit waveforms with prescribed ambiguity functions (AFs) and beampatterns while adhering to the constant modulus (CM) constraint is pivotal for the forthcoming cognitive multiple-input multiple-output (MIMO) radar systems. This study delves into the AF shaping quandary within the MIMO radar framework, considering the joint constraints of waveform unimodality and desired beampattern. The established model explores higher dimensions to realize the waveform design in range–Doppler and spatial dimensions, to improve the possibility of separating target and interference. Specifically, we first formulate the waveform design problem as a jointly constrained quartic problem, with the aim of minimizing the response values corresponding to the different range–Doppler bins within the defined compound AF. Leveraging the geometric properties of CM constraint, we further transform the jointly constrained problem in the Euclidean space into a single-constraint optimization problem in the Riemannian space. Then, the Riemannian augmented Lagrangian method (RALM) is proposed to iteratively search for the optimal waveform. Subsequently, we conduct numerical experiments to validate the efficacy of the RALM algorithm. In addition, we implemented the designed waveforms in hardware systems to analyze the effects induced by nonlinear instruments
Ketogenic diets in chronic kidney disease patients: a review for skeptics by skeptics
No full textOver the last few decades, there has been growing interest in the use of ketogenic diets, mainly as a weight loss strategy. Obesity and diabetes are major risk factors for kidney disease, and obese patients with chronic kidney disease (CKD) are potential candidates for weight reducing diets, among them ketogenic diets. Of further relevance to nephrology, a limited number of recent studies suggests a favorable effect of ketogenic diets in patients affected by autosomal dominant polycystic kidney disease (ADPKD). However, concerns remain about safety in patients with CKD, particularly in the long term and in those with poor residual kidney function. The confusion surrounding the definition of ketogenic diets adds to these concerns. The aim of this review is to summarize information on the main types of ketogenic diets used in daily practice and to discuss the options for their implementation in CKD patients, limiting ultra-processed or industrial preparations. Although further studies are needed to identify the profile of CKD patients who may benefit from the implementation of ketogenic diets to treat obesity or slow the progression of ADPKD, and to assess short- and long-term safety and adherence, the available data appear promising. This critical review is intended to stimulate further research
