Previous Prototype Research Articles

GPU Based Virtual Machine for Sleptsov Net Computing

Novel paradigm of Sleptsov Net Computing (SNC) mends imperfections of modern HPC architecture with computing memory implementation and provides a vivid graphical language, fine granulation of concurrent processes, and wide application of formal methods for reliable software design. IDE and VM for SNC have been developed and described in early papers. In the present paper, we considerably reduce GPU memory and thread consumption of the previous prototype implementation, introducing a matrix with condensed columns (MCC), and enhance performance, using the first fireable transition choice on the transition sequence reordered according to the lattice of priorities. MCC takes into consideration procedures of Sleptsov net (SN) arcs processing to enhance performance with rather little overhead compared to traditional sparse matrix formats. We represent a matrix of SN arcs by a pair of considerably smaller matrices, having the same number of columns, with the number of rows equal to the maximal number of nonzero elements over the source matrix columns. The first matrix contains the indexes within the source matrix, the second matrix contains the values within the source matrix. To run an SN, we use the corresponding rectangular matrix of GPU threads, with very few indirect memory accesses via MCC. As a result, we increase VM performance in 2–4 times, and reduce by hundred times GPU memory and thread consumption on programs from the SN software collection.

TOrsion-Bar Antenna: A Ground-Based Detector for Low-Frequency Gravity Gradient Measurement

The Torsion-Bar Antenna (TOBA) is a torsion pendulum-based gravitational detector developed to observe gravitational waves in frequencies between 1 mHz and 10 Hz. The low resonant frequency of the torsion pendulum enables observation in this frequency band on the ground. The final target of TOBA is to observe gravitational waves with a 10 m detector and expand the observation band of gravitational waves. In this paper, an overview of TOBA, including the previous prototype experiments and the current ongoing development, is presented.

Design and Mechanical Validation of Commercially Viable, Personalized Passive Prosthetic Feet

Abstract Current high-performance prosthetic feet work well for many users, but the low resolution of size and stiffness categories may limit walking performance for certain users. A line of prosthetic feet with a high resolution of sizes and stiffnesses, designed through amputee-specific personalization, could provide clinical and economic value. The lower leg trajectory error (LLTE) design framework facilitates the design of high-performance, amputee-specific prosthetic feet; however, previous foot prototypes were not designed to satisfy the economic, mechanical, and aesthetic requirements for commercial adoption. The aims of this work were to understand how a personalized, affordable prosthetic foot can align with the clinical-commercial ecosystem, innovate a viable future product, and inform other prosthesis designers of considerations required to connect innovation to real-world implementation. We evaluated needs by identifying how products, capital, and services flow between stakeholders, and we elucidated design requirements for a personalized prosthetic foot that can be manufactured, distributed, and clinically provided. Based on material properties and manufacturing process capabilities, computer numerically controlled (CNC) machining of Nylon 6/6 satisfies these requirements. We present a novel parametric foot architecture that can be CNC machined, fits within a commercial foot shell, and can be designed for individual users’ body characteristics and activity levels. Prototypes made using the new foot design behaved as anticipated (1–12% error in modeled displacement), satisfied industry-standard strength (ISO 10328) and mechanical performance (AOPA dynamic heel/keel) requirements, and elicited positive feedback from both amputees and prosthetists.

Exposing a dual-readout fibre calorimeter to electron beams, in preparation for HiDRa: High-resolution calorimeter for [formula omitted] colliders

Among the proposed accelerators for the post-LHC era are the Future Circular Collider (FCC) and the Circular Electron–Positron Collider (CEPC). Both projects would take advantage of the clean environment and low radiation damage of electron–positron collisions, providing the highest precision studies of electroweak and Higgs physics. The relatively high branching fraction of W, Z and Higgs bosons into hadronic jets makes the precise measurements of these objects an essential aspect on detector development for experiments at future collider facilities. One of the most promising calorimetry techniques for improved hadron energy reconstruction is the dual-readout method, which exploits signals from two different physics processes to correct for the fem of hadron showers, therefore boosting the standalone calorimeter performance. The usage of compact photosensors (e.g. Silicon PhotoMultipliers) for the readout enables a very fine segmentation, opening to particle-flow and advanced neural networks software reconstruction of events. In this contribution, the results of testing a small-scale dual-readout calorimeter prototype, characterised by a mixed PMT and SiPM readout solution, with an electron beam at the CERN SPS facility in the energy range [10, 120] GeV are presented. It follows the description of a larger prototype of the same type, currently under construction in the context of the INFN HiDRa project, that will be large enough to fully contain hadron showers. The design, construction technique and expected performance, as estimated through a Geant4 simulation parameterised on the previous prototype, are presented.

UGV‐Based Precision Spraying System for Chemical Apple Blossom Thinning on Trellis Trained Canopies

ABSTRACTBlossom thinning is one of the key steps in apple crop load management that improves the quality of apples, reduces stress on the trees, and avoids the likelihood of biennial bearing. Conventional chemical blossom thinning such as air‐blast spraying can lead to excessive use of chemical thinner to ensure full coverage, which can also cause leaf damage fruit russeting. In addition, a well‐trained operator is required to use these chemical spraying systems. To address these challenges, a UGV‐based precision spraying system was developed for automated and targeted chemical blossom thinning for apples. The system is capable of automatically driving along the tree row in the orchard environment during blooming stage, locating apple flower clusters to be thinned using a real‐time machine vision system, and precisely spraying the chemical thinner to the targeted flower clusters. A set of field tests were conducted to evaluate the performance of the UGV‐based target spraying system by comparing it to a conventional air‐blast sprayer (ABS) and a previous prototype named the cartesian target sprayer (CTS). Tests showed that the flower cluster detection reached a precision of 93.8%. The UGV‐based spraying system used 2.2 L of chemical thinner to finish the chemical thinning for 30 apple trees, followed by the ABS and CTS with 4.2 and 2.4 L usage, respectively. The robotic system also obtained an average fruit set of 2.2 per cluster after thinning, which was comparable to that with the air blast sprayer. The findings indicated that the robotic thinning system demonstrated a 66.7% reduction in chemical usage compared to the ABS and exhibited a 43.0% faster operational pace than the CTS, while attaining a comparable fruit set per cluster. The outcomes of the study provided guidance for developing a full scale robotic chemical thinning system for modern apple orchards.

Three-Dimensional Printing with Earthen Materials: A Settlement-Scale Design Experience

This case study originates as a design experiment for a sustainable housing system built on-site. The context is Niamey, the capital of Niger. The study takes into account the environmental issues in the construction sector and aims to find a solution capable of meeting housing, environmental, and economic needs. In the field of earthen construction, the most important developments have been achieved in manufacturing methods. In particular, the use of an additive digital manufacturing system, such as large-scale 3D printing, allows the construction of complex shapes derived from structural and thermal studies, maintaining a high degree of automation in the construction process, reducing construction times and labor costs. This paper investigates the possibility of responding to housing and environmental needs with a settlement system made almost entirely of printed earth, maintaining the highest possible degree of automation. Starting from a study on the state of the art of 3D printing in architecture and printable earthen compounds, the design choices of similar cases are analyzed to understand the construction techniques, potentials, and limitations of the medium. Finally, a design proposal is developed based on the definition of a fully printable functional module, which, upon aggregation, determines the characteristics of the final settlement. This implies a radical change of approach compared to previous prototyping of 3D-printed earthen buildings, as the design of the single functional module is not an exercise that finds completion in itself, but is oriented to the scale of the settlement right from the definition of its basic geometric characteristics. In other words, the settlement is no longer the result of the serial aggregation of independent basic units, but arises spontaneously from the juxtaposition of functional modules designed to interact with each other and merge into a single residential complex. The settlement is, therefore, the large-scale replication of the alternation between full and empty spaces, that characterizes the single functional module and, even more importantly, the replication can take multiple forms. In fact, the full and empty spaces of the functional module are planned to allow multiple combinations of aggregation. This introduces a certain degree of customization into the growth dynamics of the settlement, a factor that is entirely new compared to previous proposals by repeatable modules. No less important are the environmental implications, as designing for the scale of the settlement allows the low carbon footprint typical of earth-based construction to be extended from the single building to the entire settlement.

Thermodynamic analysis and optimization of a condensation-driven dilution refrigerator

Dilution refrigerators are widely used in the fields of condensed matter physics and quantum technology. The condensation-driven dilution refrigerator uses a condenser operating at temperatures below the Still to liquefy the 3He vapor and achieve the circulation of 3He, which has the advantages of compact structure, lightweight, low cost, and low vibration. The published research primarily focuses on the system architecture and performance, and the research and analysis on the thermodynamic cycle are still incomplete. In this paper, the condensation-driven dilution refrigeration cycle has been clarified as a thermally driven refrigeration cycle, and the thermodynamic performances including the figure of merit and thermodynamic perfectibility are investigated. Optimizations have been made to the key components of the previous prototype, and the lowest no-load temperature of 68 mK and a cooling power of 4 μW at 100 mK were achieved. Compared with the previous prototype, the thermodynamic perfectibility of the system increased from 7.63% to 17.83%. The impact of the Still heating strategies on the system was analyzed, and a start-up strategy was proposed to speed up the cooldown process.

A sample-and-hold-based sine wave phase measurement system

In this paper, a new prototype of a Phase Measurement System (PMS) is presented. The PMS uses a Sample & Hold (S&H) circuit-based architecture, and it is capable of performing phase measurements with very low uncertainty over a wide bandwidth. The prototype covers a frequency range from 100 Hz to 100 MHz, and it consists of three main subsystems: (i) a bank of four S&H circuits, (ii) a pulse train signal generator with coarse and fine delay control, and (iii) a data acquisition circuit followed by digital signal processing.The paper describes the method and system-level architecture of the PMS, as well as its capabilities. Experimental results show that the PMS can provide high-accuracy time measurements from high-accuracy amplitude measurements. For a sinewave frequency of 10 MHz, the maximum standard deviation obtained was 0.019°, while for a frequency of 100 MHz, the maximum standard deviation was 0.73°. These results represent a significant improvement compared to the previous PMS prototype and reference measurement instrumentation.

A115 EVALUATING THE CONTENT AND FACE VALIDITY OF LOW-COST GEL POLYPS FOR POLYPECTOMY SKILLS TRAINING IN NOVICE ENDOSCOPISTS

Abstract Background Polypectomy is an essential endoscopic skill involving the removal of potentially premalignant lesions during colonoscopy. The ad hoc nature of polyp encounters is a significant barrier to polypectomy training, as this limits the ability to deliberately practice the skill. Effective and accessible polypectomy simulators may improve global implementation of polypectomy curricula. Aims To determine the face and content validity of a novel low-cost gel polyp simulator for use in endoscopic training programs. Methods A novel gel polyp simulator with multiple polyp morphologies based on the Paris classification was developed and used with a commercially available colonic phantom (Koken Lower GI Endoscopy Simulator Type II LM-107, Koken CO.LTD, Japan) in an endoscopy simulation-based training course (July, 2023). Feedback based on previous prototypes of the simulator were implemented into the simulator utilized in the present study. Novice (ampersand:003C25 procedures) and expert (ampersand:003E1000 procedures) endoscopists performed simulated procedures with the gel polyps. Using a five-point Likert scale (“strongly agree” to “strongly disagree”), a post-training survey based on previously published surveys used to determine the face and content validity of low-cost physical colonic simulators was administered. A section for additional comments was placed at the end of the survey. Results The face and content validity survey was completed by 3 experts and 21 novices. The median score for all face validity questions was 5 (IQR 5-5) from experts and 5 (IQR 5-5) from novices. The median score for all content validity questions was 5 (IQR 5-4) from experts and 5 (IQR 5-5) from novices. In the additional comments section of the survey, one expert commented that future iterations of the gel polyps should be made thicker so that trainees could practice using endoscopic clips. The gel polyp simulator cost $0.61 CAD/polyp including the cost of materials and 3D printed molds. Conclusions The gel polyp simulator appears to be a feasible modality for polypectomy training that is reproducible using accessible and low cost materials. Face and Content Validity Survey (questions and median survey score) Funding Agencies None

Optimized Ferromagnetic Core Magnetorquer Design and Testing for LEO Nanosatellite Attitude Control

Magnetorquers are a very suitable solution for the nanosatellite’s attitude and orbital control of low Earth orbit (LEO) given its constraints: small available volume, limited power consumption, and maximum weight limitation. In this work, an optimized ferromagnetic core magnetorquer is designed for LEO nanosatellites, considering the geometrical, electrical, and magnetic parameters in an electromagnetic finite element analysis (FEA). The final design dimensions are 10.9 mm diameter and 100 mm in length, with a ferromagnetic core made of high performance soft magnetic alloy Vacoflux50 measuring 5 mm diameter and 100 mm in length. Magnetorquer geometry has been optimized to achieve a very high compactness, reaching an optimal combination of high specific magnetic moment and magnetic moment-input power ratio at the same time. It shows a maximum magnetic moment of 1.42 Am2, a magnetic moment-input power ratio of 2.52 Am2/W, and a specific magnetic moment of 22.5 Am2/kg, with a power consumption of 0.565 W and 0.5 A. Such a combination of high-performance values has not been previously found. Furthermore, it has displayed higher magnetic moment and specific magnetic moment than previous prototypes in literature. The simulated model is validated with the experimental testing of a manufactured prototype, by measuring the magnetic and electric variables.

A new high-performance flat plate solar collector. Numerical modelling and experimental validation

A new concept of flat plate solar collector (FPC) has been numerically studied for optimization purposes from an energetic and exergetic points of view. The highly efficient results have been achieved by adding transparent insulation materials (TIM) made of plastic and aerogel-silica in the cover. The optimum solution has been prototyped and successfully tested. The numerical simulation and the corresponding analysis are performed with a previously developed numerical simulation tool based on an in-house software platform (NEST). An optimization design has been done using this numerical simulation tool objected to higher performance at the (Tin−Tamb)/Ġ>0.074 range, and a new prototype is fabricated with low-cost materials found in the workshop. The final results are compared with previous prototypes that could collect between 2.5 and 1.4 times higher than standard collectors in summer and autumn, respectively. The new prototype has higher performance at (Tin−Tamb)/Ġ>0.074, which makes it competitive in a high-temperature range. Moreover, with the new layer of aerogel-silica, additional protection against overheating is achieved, as the temperatures of the plastic TIM are limited. The new prototype has higher energetic and exergetic efficiency at high-temperature areas, and the inlet temperature at optimized working conditions is higher than the previous prototype. Finally, the energy efficiency at (Tin−Tamb)/Ġ=0.08 could reach 55% and exergetic efficiency 8%. The manufacturing cost of the FPC prototype with TIM and aerogel-silica is about 160 euros per m2.

Enhancing Chromatographic Analysis: A Novel Cryo-Enrichment Module for GC Analysis of Terpenes in Cannabis sativa.

This study presents the development and validation of a gas chromatography (GC) method using cryo-enrichment for the analysis of α-pinene and β-caryophyllene in Cannabis sativa plant. Cryo-enrichment is a method that involves cooling part of the GC column to improve some aspect of chromatographic analysis. The aim of this study was to improve upon previous GC cryo-enrichment prototype and to create and validate a method for the analysis of these terpene compounds, which have received increasing attention for their medicinal properties. The improved cryo-enrichment device used in this study was built in-house and used a custom-built aluminum GC column holder cooled by a two-stage cryo-cooler. The validated method was found to be precise, accurate and sensitive, with good repeatability.

An investigation of a supersonic fluidic oscillator generating pulsations in chambers during pressurization

A load-type supersonic fluidic oscillator has potential application for introducing small oscillations in the chamber of a superplastic forming process to improve performance. This paper presents a study of a special bi-stable load-type supersonic fluidic oscillator capable of simultaneously producing self-sustained oscillations in two gas pressure chambers during their filling at high-pressure. The experimental portion of the work verifies the robust nature of the device performance. Distinct differences, however, are observed compared to those previously shown for a similar prototype supplying pressure fluctuations to a single chamber at low pressure. It is also found that a three-dimensional computational fluid dynamics model is required to accurately simulate the transient filling process of the current oscillator facility, unlike the previous case. This leads to an unaffordable computational cost. To address this issue, a low-order fluid circuit model is developed. This simplified approach is based on a quasi-steady assumption and is of the same form as the one which accurately predicts the performance of the previous prototype. The model is “numerically empirical” in that the model parameters are determined using steady state 3D-CFD analysis rather than physical experiments. The circuit model combined with a lumped parameter numerical model of tank filling with realistic heat transfer to the surroundings provides an accurate and rapid prediction of the transient performance of the device. Also, the usefulness of the circuit model as an industrial design tool is demonstrated by predicting the effect of two design changes.

Compact and modular system architecture for a nano-resonator-mass spectrometer.

Mass measurements in the mega-to giga-Dalton range are essential for the characterization of natural and synthetic nanoparticles, but very challenging to perform using conventional mass spectrometers. Nano-electro-mechanical system (NEMS) based MS has demonstrated unique capabilities for the analysis of ultra-high mass analytes. Yet, system designs to date included constraints transferred from conventional MS instruments, such as ion guides and high vacuum requirements. Encouraged by other reports, we investigated the influence of pressure on the performances of the NEMS sensor and the aerodynamic focusing lens that equipped our first-generation instrument. We thus realized that the NEMS spectrometer could operate at significantly higher pressures than anticipated without compromising particle focusing nor mass measurement quality. Based on these observations, we designed and constructed a new NEMS-MS prototype considerably more compact than our original system, and which features an improved aerodynamic lens alignment concept, yielding superior particle focusing. We evaluated this new prototype by performing nanoparticle deposition to characterize aerodynamic focusing, and mass measurements of calibrated gold nanoparticles samples. The particle capture efficiency showed nearly two orders of magnitude improvement compared to our previous prototype, while operating at two orders of magnitude greater pressure, and without compromising mass resolution.

Hydrodynamic and energy-harvesting performance of a BBDB-OWC device in irregular waves: An experimental study

The back-bent duct buoy (BBDB) can be used as a floating oscillating water column (OWC) wave energy converter, showing its potential and reliability in most previous prototype sea trials. In this study, an experimental test on a generic BBDB OWC model was conducted in a wave flume using irregular wave scenarios. By using a specific mechanism, the degree-of-freedom (DOF) of the model can be preset in four modes: the ZDOF (the model is fixed with zero DOF) mode, the TDOFs mode (the model conducts the pitching and heaving motions with two DOFs), the SDOF-P mode (the model conducts the pitching motion with the single DOF), and the SDOF-H mode (the model conducts the heaving motion with the single DOF). The kinematic, hydrodynamic, and aerodynamic responses and energy-harvesting performances of the BBDB model were presented and analyzed. It was found that the pitching and heaving motions made positive and negative contributions to wave power capturing of the model, resulting in a moderate energy-harvesting performance for the TDOFs mode. Furthermore, the analysis indicated that strengthening the pitching motion and restraining the heaving motion will benefit the wave energy conversion of the BBDB device.

Exploring Enhancement of AR-HUD Visual Interaction Design Through Application of Intelligent Algorithms

This study aims to optimize the visual interaction design of AR-HUD and reduce cognitive load in complex driving situations. An immersive driving simulation incorporating eye-tracking technology was utilized to analyze objective physiological indices and measure subjective cognitive load using the NASA-TLX. Additionally, a visual cognitive load index was integrated into a BP-GA neural network model for load prediction, enabling the derivation of an optimal solution for AR-HUD design. The optimized AR-HUD interface demonstrated a significant reduction in cognitive load compared to the previous prototype. The experimental group achieved a mean total score of 25.63 on the WP scale, whereas the control group scored 43.53, indicating a remarkable improvement of 41.1%. This study presents an innovative approach to optimizing AR-HUD design, effectively reducing cognitive load in complex driving situations. The findings demonstrate the potential of the proposed algorithm to enhance user experience and performance.

NetBID2 provides comprehensive hidden driver analysis

Many signaling and other genes known as “hidden” drivers may not be genetically or epigenetically altered or differentially expressed at the mRNA or protein levels, but, rather, drive a phenotype such as tumorigenesis via post-translational modification or other mechanisms. However, conventional approaches based on genomics or differential expression are limited in exposing such hidden drivers. Here, we present a comprehensive algorithm and toolkit NetBID2 (data-driven network-based Bayesian inference of drivers, version 2), which reverse-engineers context-specific interactomes and integrates network activity inferred from large-scale multi-omics data, empowering the identification of hidden drivers that could not be detected by traditional analyses. NetBID2 has substantially re-engineered the previous prototype version by providing versatile data visualization and sophisticated statistical analyses, which strongly facilitate researchers for result interpretation through end-to-end multi-omics data analysis. We demonstrate the power of NetBID2 using three hidden driver examples. We deploy NetBID2 Viewer, Runner, and Cloud apps with 145 context-specific gene regulatory and signaling networks across normal tissues and paediatric and adult cancers to facilitate end-to-end analysis, real-time interactive visualization and cloud-based data sharing. NetBID2 is freely available at https://jyyulab.github.io/NetBID.

Design of nonlinear phase prototype filter based on coefficients symmetry for UFMC communication system

One of the candidates for short burst communication is universal filtering multicarrier (UFMC), which applies filters in each sub-band to reduce intercarrier interference. Compared with the linear phase FIR filter (LPFF), prototyping a nonlinear phase FIR filter (NLPFF) as the UFMC filter can benefit system performance by improving the filter magnitude response. However, the benefit, namely the tradeoff between phase response and better magnitude, is limited in previous NLPFF designs. Aiming at this problem, this paper has done the following works. First, we propose a new measure called sum of symmetric coefficient differences (SSCD) to represent the phase deviation. Furthermore, we propose a constrained least squares design for NLPFF, where constraints are imposed on the SSCD and squared magnitude. The design can be effectively realized under the second-order cone programming (SOCP) framework. Due to the significantly reduced constraint size and enhanced performance tradeoff area, the proposed SOCP-SSCD approach is the most competitive in effectiveness and efficiency. We have demonstrated this advantage by comparing with previous NLPFF methods. Consequently, by applying this method to design NLPFF as a prototype filter in the UFMC system, we have achieved better power spectral density, symbol error rate (SER), and demodulated constellation than previous prototype filters. For the SER indicator, Fig. 6(a) indicates an SNR gain of 1.2dB@{SER=0.001} between the designed NLPFFs and the previous prototype filters.

Development and Control of a Real Spherical Robot.

This paper presents the design and implementation of a spherical robot with an internal mechanism based on a pendulum. The design is based on significant improvements made, including an electronics upgrade, to a previous robot prototype developed in our laboratory. Such modifications do not significantly impact its corresponding simulation model previously developed in CoppeliaSim, so it can be used with minor modifications. The robot is incorporated into a real test platform designed and built for this purpose. As part of the incorporation of the robot into the platform, software codes are made to detect its position and orientation, using the system SwisTrack, to control its position and speed. This implementation allows successful testing of control algorithms previously developed by the authors for other robots such as Villela, the Integral Proportional Controller, and Reinforcement Learning.

Query-Guided Prototype Learning with Decoder Alignment and Dynamic Fusion in Few-Shot Segmentation

Few-shot segmentation aims to segment objects belonging to a specific class under the guidance of a few annotated examples. Most existing approaches follow the prototype learning paradigm and generate category prototypes by squeezing masked feature maps extracted from images in the support set. These support prototypes may lead to inaccurate predictions when directly compared with features extracted from the query set due to the considerable distribution discrepancy between support and query features. We propose a query-guided prototype learning architecture to address this problem from two aspects: (i) We propose a cross-alignment loss for training the segmentation decoder. This loss function will help the decoder improve its robustness against the distribution discrepancy between support and query features. (ii) We build a dynamic fusion module to strengthen the original support prototype with another prototype extracted from query features. Experiments show that our method achieves promising results compared to previous prototype learning methods on PASCAL-5 i and COCO-20 i datasets.