Fast Data Acquisition Research Articles

Neutron–gamma discrimination based on quantum clustering technique

Abstract In this study, the digital neutron–gamma discrimination (DNGD) has been undertaken based on the pulse-shape discrimination on the anode pulse of a 2” by 2” right cylinder BC501A liquid scintillator with a fast data acquisition card (14-bit resolution, 500 MS/s). Seven different features of the anode pulse have been extracted and the discrimination based on quantum clustering (DBQC) has been studied. The influence of three different parameters (i.e., η , σ and K) on the discrimination figure-of-merit (FoM) has been investigated. In addition, the FoM dependencies on different choices of DBQC features have been determined. A 100 mCi 241Am-Be neutron source has been used for the DNGD and the calibration has been made with a 1.1 μ Ci 22Na gamma-ray source. The results show that the FoM value is around 1 at 100 keVee bias energy, whilst this value can be improved up to 50% by choosing and setting appropriate features.

Quantitative condition inspection and assessment of tunnel lining

Abstract To ensure the safety and the serviceability of underground structures, routine inspections and maintenance processes are essential for their optimal use. Presently, the practical inspection of tunnels depends on human-based methods, which has inherent limitations. This study proposed a quantitative system for the health inspection and assessment of the tunnel lining. The system is capable of acquiring and extracting cracks or other defects efficiently, drawing crack charts automatically and assessing the situation of tunnel lining with a much more accurate index. The consistency of the cracks automatically extracted by the proposed tunnel lining inspection system is verified with the investigation of two tunnels using different construction methods. For the health assessment of tunnel lining, a valid index is introduced to evaluate the lining status according to the fractal dimension of cracks. Results of the comparative tests and field tests indicate the validity of crack fractal dimension D. In addition, results of several real cases on field tests demonstrate its practicability. Such a system can achieve time-saving automated surveying solutions with fast data acquisition, identification and documentation of cracks as well as detection of structural changes. For an all-around assessment of the health situation for tunnel lining, the influence of strength characteristics of the tunnel lining due to its irregular shape should be taken into consideration in future research.

Machine-learning reprogrammable metasurface imager

Conventional microwave imagers usually require either time-consuming data acquisition, or complicated reconstruction algorithms for data post-processing, making them largely ineffective for complex in-situ sensing and monitoring. Here, we experimentally report a real-time digital-metasurface imager that can be trained in-situ to generate the radiation patterns required by machine-learning optimized measurement modes. This imager is electronically reprogrammed in real time to access the optimized solution for an entire data set, realizing storage and transfer of full-resolution raw data in dynamically varying scenes. High-accuracy image coding and recognition are demonstrated in situ for various image sets, including hand-written digits and through-wall body gestures, using a single physical hardware imager, reprogrammed in real time. Our electronically controlled metasurface imager opens new venues for intelligent surveillance, fast data acquisition and processing, imaging at various frequencies, and beyond.

Detection of Gold Nanoparticles in Hydrothermal Fluids

The transport and deposition of gold from colloidal suspensions in hydrothermal fluids has been a persistent theme in ore deposits research. Studies of active geothermal systems show that a complete model of gold transport must include both dissolved and particulate forms. However, samples of the hydrothermal fluids are commonly spiked with aqua regia after collection in order to put any solids back into solution, thus preventing a quantitative assessment of the particle load. Although attempts have been made to filter the solids, gold nanoparticles (Au NPs) will mostly pass the 0.2-µm filters that are in common use, and a simple technique for analyzing suspended particles in the liquids has been lacking. In this study, we demonstrate how time-resolved acquisition of mass 197 in a conventional inductively coupled plasma-mass spectrometer (ICP-MS) can be used to detect and measure Au NPs in the filtered liquids, with an example of well-characterized fluids from the Reykjanes geothermal field on Iceland. The technique allows for precise monitoring of the solution as it is introduced into the plasma with the capability of identifying individual particles carried in suspension. Results show that Au particles passing the 0.2-µm filters are abundant in the studied samples, and measurements of the individual particles can be used to determine their size. The experiment highlights the potential of emerging ICP-MS techniques, including very fast data acquisition and multielement analysis of single particles in timeof-flight mode, for characterization of NPs in hydrothermal fluids.

COMPARATIVE ANALYSIS OF 3D PHOTOGRAMMETRY MODELING SOFTWARE PACKAGES FOR DRONES SURVEY

Abstract. Drones are becoming popular in spatial mapping or survey. The use of drones survey can be seen from it low flying heights (capable to create a clear images), accessible on difficult or non-friendly vehicle access areas, faster data acquisition and higher data resolution henceforth improve the quality of the survey. However, this paper focuses on the post-processing of drone images for 3D surface modeling. With the motivation of producing better 3D models, four software packages are used for comparison. Those software packages are eyesMap3D, Drone Deploy, Agisoft PhotoScan and Pix4Dmapper. The equipment used to ensure a high level of quality model is the Leica GPS1200+ stationary GPS module and the DJI Phantom 4 PRO drone. The Leica GPS1200+ stationary GPS module were used to track the exact position of tie points on the ground. Meanwhile the DJI Phantom 4 PRO drone is used as data inputs (images) for the software packages stated. In addition, the drone is used to fly over a golf course, with a challenge of homogenous surface for 3D surface modeling. Based on the output, it shows that each software packages produces slightly different outputs. This paper summarizes the outputs and discusses the key elements in each software packages. This variation might be useful for future references in 3D surface modeling that can conform in different applications requirements.

Single-shot ptychographic iterative engine based on chromatic aberrations

A single shot ptychographic iterative engine based on chromatic aberrations is proposed to retrieve the object with fast data acquisition and convergence. In the imaging system, the specimen is irradiated by a RGB illumination source, and the RGB light transmitted through the specimen is recorded by a color sensor. There are three different sizes of the spots on the object surface generated by the lens with chromatic aberrations and the aperture stop, which can produce partially overlapping between adjacent wavelength illumination areas that will lock the object’s phase information and ensure retrieve the object successfully. In the reconstruction algorithm, an initial object guess is established by spectrum synthesis method to accelerate convergence and suppress noise. The data acquisition time is dramatically reduced by our proposed single shot method.

A setup for extreme-ultraviolet ultrafast angle-resolved photoelectron spectroscopy at 50-kHz repetition rate.

Time- and angle-resolved photoelectron spectroscopy (trARPES) is a powerful method to track the ultrafast dynamics of quasiparticles and electronic bands in energy and momentum space. We present a setup for trARPES with 22.3 eV extreme-ultraviolet (XUV) femtosecond pulses at 50-kHz repetition rate, which enables fast data acquisition and access to dynamics across momentum space with high sensitivity. The design and operation of the XUV beamline, pump-probe setup, and ultra-high vacuum endstation are described in detail. By characterizing the effect of space-charge broadening, we determine an ultimate source-limited energy resolution of 60 meV, with typically 80-100 meV obtained at 1-2 × 1010 photons/s probe flux on the sample. The instrument capabilities are demonstrated via both equilibrium and time-resolved ARPES studies of transition-metal dichalcogenides. The 50-kHz repetition rate enables sensitive measurements of quasiparticles at low excitation fluences in semiconducting MoSe2, with an instrumental time resolution of 65 fs. Moreover, photo-induced phase transitions can be driven with the available pump fluence, as shown by charge density wave melting in 1T-TiSe2. The high repetition-rate setup thus provides a versatile platform for sensitive XUV trARPES, from quenching of electronic phases down to the perturbative limit.

Fast data acquisition techniques in magnetic resonance spectroscopic imaging.

Magnetic resonance spectroscopic imaging (MRSI) is an important technique for assessing the spatial variation of metabolites in vivo. The long scan times in MRSI limit clinical applicability due to patient discomfort, increased costs, motion artifacts, and limited protocol flexibility. Faster acquisition strategies can address these limitations and could potentially facilitate increased adoption of MRSI into routine clinical protocols with minimal addition to the current anatomical and functional acquisition protocols in terms of imaging time. Not surprisingly, a lot of effort has been devoted to the development of faster MRSI techniques that aim to capture the same underlying metabolic information (relative metabolite peak areas and spatial distribution) as obtained by conventional MRSI, in greatly reduced time. The gain in imaging time results, in some cases, in a loss of signal-to-noise ratio and/or in spatial and spectral blurring. This review examines the current techniques and advances in fast MRSI in two and three spatial dimensions and their applications. This review categorizes the acceleration techniques according to their strategy for acquisition of the k-space. Techniques such as fast/turbo-spin echo MRSI, echo-planar spectroscopic imaging, and non-Cartesian MRSI effectively cover the full k-space in a more efficient manner per TR . On the other hand, techniques such as parallel imaging and compressed sensing acquire fewer k-space points and employ advanced reconstruction algorithms to recreate the spatial-spectral information, which maintains statistical fidelity in test conditions (ie no statistically significant differences on voxel-wise comparisions) with the fully sampled data. The advantages and limitations of each state-of-the-art technique are reviewed in detail, concluding with a note on future directions and challenges in the field of fast spectroscopic imaging.

Dual frequency comb photon echo spectroscopy

Dual frequency comb (DFC) nonlinear spectroscopy is an emerging technique that can be used to study a variety of molecular nonlinear responses by exploiting the automatic pulse-to-pulse time delay scanning and fast data acquisition characteristics of the DFC techniques. Here, we propose a DFC-based photon echo spectroscopy (DFC-PES), where two optical frequency comb lasers have slightly different repetition rates and are also allowed to have different carrier frequencies. We first demonstrate our theoretical approach for DFC linear spectroscopy. Then, the signals expected from the proposed DFC-PES are theoretically calculated. The slight offset in the pulse repetition rates enables asynchronous optical sampling and automatic scanning of the time intervals between different field–matter interaction events, making frequency tuning unnecessary. Analytic expression of the third-order photon echo signal is demonstrated in two frequency dimensions for a simple two-level model system. The signal has a well-defined and simple connection to the underlying third-order response function and exhibits the expected down-conversion features from the optical frequency into the radio frequency region with a down-conversion factor that is experimentally controllable.

Use of EHRs data for clinical research: Historical progress and current applications.

The benefits of reusing EHR data for clinical research studies are numerous. They portend the opportunity to bring new therapies to patients sooner, potentially at a lower cost, and to accelerate learning health cycles—through faster data acquisition in clinical research studies. Metrics have proven that time can be saved, workflow and processes streamlined, and data quality increased significantly. Pilot projects and now actual investigational trials used for regulatory submissions have shown that these benefits support the transformation of clinical research by leveraging EHRs for research. Panelists at a recent collaborative focused on bridging clinical research and clinical care offered varying perspectives on how the latest standards and technologies could be leveraged to facilitate data transfer from EHR systems into clinical research databases, as well as the associated improvements in data quality. Panelists also discussed other avenues to leverage EHR in clinical research. Improvements and exciting possibilities notwithstanding, much work remains. Data ownership and access, attention to metadata and structured data for data sharing, and broader adoption of global standards are key areas for collaboration. With the steady increase in adoption of EHRs around the world, this is an excellent time for all stakeholders to work together and create an environment such that EHRs can be used more readily for research. The capacity for research can thus be increased to provide more high‐quality information that will contribute to rapid continuous learning health systems from which all patients can benefit.

Fast NMR Methods for Identification of Resonances and Metabolic Pathways.

High-throughput analysis of NMR data in metabolomics involves both rapid data acquisition and analysis. We describe here a data collection and analysis protocol, which enables fast multidimensional NMR data acquisition and automated analysis of NMR spectra to rapidly identify the metabolites and assign them to active metabolic pathways in the system.

LHCb MiniDAQ control system

LHCb is one of the 4 experiments at the LHC accelerator at CERN, specialized in B-physics. During the next long shutdown period, the LHCb experiment will be upgraded to a trigger-less readout system with a full software trigger in order to be able to record data with a much higher instantaneous luminosity. To achieve this goal, the upgraded systems for Timing and Fast Control (TFC) and Data Acquisition (DAQ) will have new electronic boards and a new software stack will be introduced for data acquisition. In the development stage, all these components are housed in servers named MiniDAQ. These new components will need to be integrated in an upgraded Experiment Control System (ECS) based on the WinCC OA SCADA and the CERN JCOP framework. The ECS provides full monitoring and control for all these subsystems and many important features like configuration recipes and automated actions. This paper describes the implementation of the upgraded ECS and its component fwMiniDAQ, which integrates all the new developments and can be easily distributed to the sub-detector developers and configured for their various setups.

Understanding fracture distribution and its relation to knickpoint evolution in the Rio Icacos watershed (Luquillo Critical Zone Observatory, Puerto Rico) using landscape‐scale hydrogeophysics

AbstractThe Rio Icacos watershed in the Luquillo Mountains (Puerto Rico) is unique due to its extremely rapid weathering rates. The watershed is incised into a quartz diorite that has developed a large knickzone defining the river profile. Regolith thickness within the watershed generally decreases from 20 to 30 m at the ridges to several meters in the quartz diorite‐dominated valley to tens of centimeters near the major river knickpoint, as determined from previous studies. Above the knickzone, we observe spheroidal corestones, but below this weathering is much less apparent. Measured erosion rates from previous studies are also high in the knickzone compared with upper elevations within the river profile. A suite of near‐surface geophysical methods (i.e. ground penetrating radar and terrain conductivity) capable of fast data acquisition in rugged landscapes, was deployed at kilometer scales to characterize critical zone structure. Concentrations of chaotic ground penetrating radar (GPR) reflections and diffraction hyperbolas with low electrical conductivity were observed in vertical zones that outcrop at the land surface as areas of intense fracturing and spheroidally weathered corestones. The width of these fractured and weathered zones showed an increase with proximity to the knickpoint, and was attributed to dilation of these sub‐vertical fractures near the knickpoint, as postulated theoretically by a stress model calculated for the topographic variability across the knickzone in the Rio Icacos, and that shows a release of compressive stress near the knickpoint. We hypothesize that erosion rates increase in the knickzone because of this inferred dilation of fractures. Specifically, opened fractures could enhance access of water and in turn promote spalling, erosion, and spheroidal weathering. This study shows that ground‐based hydrogeophysical methods used at the landscape‐scale (traditionally applied at smaller scales) can be used to explore critical zone architecture at the scales needed to explain the extreme variability in erosion rates across river profiles. © 2018 John Wiley & Sons, Ltd.

Fast and high-resolution mapping of elastic properties of biomolecules and polymers with bimodal AFM.

Fast, high-resolution mapping of heterogeneous interfaces with a wide elastic modulus range is a major goal of atomic force microscopy (AFM). This goal becomes more challenging when the nanomechanical mapping involves biomolecules in their native environment. Over the years, several AFM-based methods have been developed to address this goal. However, none of these methods combine sub-nanometer spatial resolution, quantitative accuracy, fast data acquisition speed, wide elastic modulus range and operation in physiological solutions. Here, we present detailed procedures for generating high-resolution maps of the elastic properties of biomolecules and polymers using bimodal AFM. This requires the simultaneous excitation of the first two eigenmodes of the cantilever. An amplitude modulation (AM) feedback acting on the first mode controls the tip-sample distance, and a frequency modulation (FM) feedback acts on the second mode. The method is fast because the elastic modulus, deformation and topography images are obtained simultaneously. The method is efficient because only a single data point per pixel is needed to generate the aforementioned images. The main stages of the bimodal imaging are sample preparation, calibration of the instrument, tuning of the microscope and generation of the nanomechanical maps. In addition, with knowledge of the deformation, bimodal AFM enables reconstruction of the true topography of the surface. It takes ~9 h to complete the whole procedure.

A multi-UAV cooperative route planning methodology for 3D fine-resolution building model reconstruction

In order to provide a fast multi-UAV cooperative data acquisition approach for 3D building model reconstruction in emergency management domain, a route planning methodology is proposed. A minimum image set including camera shooting positions and attitudes can be firstly obtained, with the given parameters describing the target building, UAVs, cameras, and image overlap requirements. A specific flight route network is then determined, and the optimal solution for multi-UAV data capture route planning is computed on the basis of constraint conditions such as the time frame, UAV battery endurance, and take-off and landing positions. Furthermore, field experiments with manual operating UAV mode, single UAV mode, and multi-UAV mode were conducted to compare the data collection and processing runtimes, as well as the quality of created 3D building models. According to the five defined LoDs of OGC CityGML 2.0 standard, the fine 3D building models conform to the LoD3. Comparison results demonstrate that our method is able to greatly enhance the efficiency of 3D reconstruction by improving the data collection speed while minimizing redundant image datasets, as well as to provide a normalized approach to assign the single or multi-UAV data acquisition tasks. The quality analysis of 3D models shows that the metric difference is less than 20 cm mean error with a standard deviation of 11 cm, which is fairly acceptable in emergency management study field. A 3D GIS-based software demo was also implemented to enable route planning, flight simulation, and data collection visualization.

Gunshot Wounds: Ballistics and Imaging Findings

Ballistic traumas are defined by a projectile entering the body. Such projectiles include bullets, birdshot, and metal fragments from the covering or the contents of an explosive device. They frequently cause severe wounds characterized by a range of clinical pictures and a large spectrum of concomitant wounds. The major aims of imaging are to define the path of the projectile or projectiles, to evaluate which tissues have been injured, to estimate the severity of injury, and to determine what additional studies are needed. A routine radiograph is performed in patients with gunshot wounds. The diagnostic approach has been changed by the use of multidetector row computed tomography (MDCT) due to its technical developments particularly faster data acquisition and advanced image reconstructions. In the evaluation of patients with gunshot injuries, MDCT is considered the method of choice to identify hemorrhage, bullet, bone fragments, air, hemothorax, nerve lesions, musculoskeletal lesions, and vessel injuries. Moreover, MDCT technology and multiplanar reformation postprocessing allow meticulous trajectory analysis that potentially benefits the clinical outcomes of patients aiding time-saving triage and correct image-based diagnosis of organ and vessel damage. Familiarity of ballistics and forensic sciences will therefore help the radiologist in assessment and localization of the damage caused by projectiles.

Dead Time Compensation for High-Flux Ranging

Dead time effects have been considered a major limitation for fast data acquisition in various time-correlated single photon counting applications, since a commonly adopted approach for dead time mitigation is to operate in the low-flux regime where dead time effects can be ignored. Through the application of lidar ranging, this work explores the empirical distribution of detection times in the presence of dead time and demonstrates that an accurate statistical model can result in reduced ranging error with shorter data acquisition time when operating in the high-flux regime. Specifically, we show that the empirical distribution of detection times converges to the stationary distribution of a Markov chain. Depth estimation can then be performed by passing the empirical distribution through a filter matched to the stationary distribution. Moreover, based on the Markov chain model, we formulate the recovery of arrival distribution from detection distribution as a nonlinear inverse problem and solve it via provably convergent mathematical optimization. By comparing per-detection Fisher information for depth estimation from high- and low-flux detection time distributions, we provide an analytical basis for possible improvement of ranging performance resulting from the presence of dead time. Finally, we demonstrate the effectiveness of our formulation and algorithm via simulations of lidar ranging.

Microwave frequency comb Doppler reflectometer applying fast digital data acquisition system in LHD.

We succeeded in increasing the radial observation points of the microwave frequency comb Doppler reflectometer system from 8 to 20 (or especially up to 45) using the high sampling rate of 40 GS/s digital signal processing. For a new acquisition system, the estimation scheme of the Doppler shifted frequency is constructed and compared with the conventional technique. Also, the fine radial profile of perpendicular velocity is obtained, and it is found that the perpendicular velocity profile is consistent with the E × B drift velocity one.

In Situ X-ray Diffraction Analysis of Stresses during Deep Rolling of Steel

Residual stresses originating from elasto-plastic deformation during mechanical processing can be analyzed post-process with various known methods. A new measurement method to measure and evaluate the strain and stress fields in situ under the contact point during a deep rolling process was developed to describe the dependence of the residual stresses from the internal material load. Using synchrotron radiation at European Synchrotron Radiation Facility (ESRF) (ID11), diffraction measurements were performed in transmission geometry during dynamical loading with different process parameters. The strain and stress fields were analyzed with high spatial resolution in an 8 mm × 4 mm area around the contact point during the process using a 13-mm tungsten carbide roller on samples of AISI 4140H steel. Fast data acquisition allowed the reconstruction of full two-dimensional (2D) strain and stress maps. These could be used to determine the response from the initial material state in front of the roller to the mechanically loaded region with plastic deformation up to the processed material with the resulting residual stresses. This comprehensive analysis was then used to link the internal material load with the resulting residual stresses in the final material state.

FPGA and Embedded Systems Based Fast Data Acquisition and Processing for GEM Detectors

Gas electron multiplier (GEM) detectors (Sauli in Nucl Instrum Methods Phys Res A 805:2–24, 2016. https://doi.org/10.1016/j.nima.2015.07.060 (special issue in memory of Glenn F. Knoll); Buzulutskov in Instrum Exp Tech 50(3):287–310, 2007. https://doi.org/10.1134/S0020441207030013) are widely used for detection of ionizing radiation. When used in the proportional mode, they provide information about time, location, and energy of a detected particle (Chernyshova et al. in Fusion Eng Design, 2017. https://doi.org/10.1016/j.fusengdes.2017.03.107; Altunbas et al. in Nucl Instrum Methods Phys Res A 490(1–2):177–203, 2002. https://doi.org/10.1016/S0168-9002(02)00910-5. http://linkinghub.elsevier.com/retrieve/pii/S0168900202009105). Modern technologies allow full utilization of detector properties, by acquiring the waveform of output current pulses and processing them using sophisticated digital signal processing (DSP) algorithms. The current pulses must be digitized at high speed (up to 125 MHz) with high resolution (up to 12-bits). Due to the high volume of the produced data, it is necessary to provide the high-performance data acquisition system (DAQ) to transmit the data to processing units. Efficient processing of the GEM data requires distributed parallel processing system to perform multiple tasks (Czarski et al. in Rev Sci Instrum 87(11), 11E336, 2016. https://doi.org/10.1063/1.4961559): (1) Filter out the background and transmit only hit related data. (2) Extract the parameters of a hit, describing the time and charge (related to energy). (3) Estimate the hit position by combining information from multiple anode pads. (4) In case of 2D GEM detectors, correlate pulses received from X and Y pads (pixels) or W, U and V pads (pixels). (5) Separate the hits overlapping in space or in time (if possible) to support detector operation at higher rates. The above functionalities may be achieved in different hardware architectures. The typical hardware platforms include FPGA chips, standard or embedded computer systems with different computation accelerators (Wojenski et al. in J Instrum 11(11):C11035, 2016. http://stacks.iop.org/1748-0221/11/i=11/a=C11035; Nowak et al. in J Phys Conf Ser 513(5):052–024, 2014. https://doi.org/10.1088/1742-6596/513/5/052024. http://stacks.iop.org/1742-6596/513/i=5/a=052024?key=crossref.c5912cfa72c30b309821e14c4384948f. The paper shows possible solutions with their feasibility for particular applications.