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The Canada lynx is listed as a threatened species, and as such, the identification and conservation of lynx habitats is of significant concern. Lynxes require areas with high amounts of horizontal cover made up of ground vegetation. Lidar offers a robust method of quantifying vegetation structure, and airborne lidar has been acquired across large areas of potential lynx habitat. Unfortunately, airborne lidar is often not able to directly measure understory horizontal cover due to occlusion from the upper branches. Terrestrial lidar does directly measure understory horizontal cover and can be used as training data for larger area models using airborne lidar. In this study, we acquired 168 individual terrestrial lidar scans (TLS) across 42 sites in north-central Washington state. We generated metrics from the single-scan TLS plots using depth maps, a digital cover board, and voxels. Using our TLS metrics as the training data for the airborne lidar acquired for the entire Loomis State Forest, we were able to produce a model using xgboost with 85% accuracy. We believe our study shows that single-scan TLS plots can be used effectively to quantify fine-scale forest structure elements relevant to species habitat, to then inform larger area models using airborne lidar. [ABSTRACT FROM AUTHOR]

Streams are temporally ordered, rapid changing, ample in volume, and infinite in nature. It is nearly impossible to store the entire data stream due to its large volume and high velocity. In this work, the principle of parallelism is employed to accelerate stream data computing. GPU-based high-performance computing (HPC) framework is proposed for accelerated processing of big-data streams using the in-memory data structure. We have implemented three parallel algorithms to prove the viability of the framework. The contributions of Mille Cheval are: (1) the viability of streaming on accelerators to increase throughput, (2) carefully chosen hash algorithms to achieve low collision rate and high randomness, and (3) memory sketches for approximation. The objective is to leverage the power of a single node using in-memory computing and hybrid computing. HPC does not always require high-end hardware but well-designed algorithms. Achievements of Mille Cheval are: (1) relative error is 1.32 when error rate and overestimate rate are chosen as 0.001 and (2) the host memory space requirement is just 63 MB for 1 terabyte of data. The proposed algorithms are pragmatic. It is evident from experimental results that the framework demonstrates 10X speed-up as compared with CPU implementations and 3X speed-up as compared with GPU implementations. [ABSTRACT FROM AUTHOR]

Purpose: Scatter contamination in the cone‐beam CT (CBCT) leads to CT number inaccuracy, spatial nonuniformity, and loss of image contrast. In our previous work, we proposed a single scan scatter correction approach using a stationary partial beam blocker. Although the previous method works effectively on a tabletop CBCT system, it fails to achieve high image quality on a clinical CBCT system mainly due to the wobble of the LINAC gantry during scan acquisition. Due to the mechanical deformation of CBCT gantry, the wobbling effect is observed in the clinical CBCT scan, and more missing data present using the previous blocker with the uniformly distributed lead strips. Methods: An optimal blocker distribution is proposed to minimize the missing data. In the objective function of the missing data, the motion of the beam blocker in each projection is estimated using the segmentation due to its high contrast in the blocked area. The scatter signals from the blocker are also estimated using an air scan with the inserted blocker. The final image is generated using the forward projection to compensate for the missing data. Results: On the Catphan©504 phantom, our approach reduces the average CT number error from 86 Hounsfield unit (HU) to 9 HU and improves the image contrast by a factor of 1.45 in the high‐contrast rods. On a head patient, the CT number error is reduced from 97 HU to 6 HU in the soft‐tissue region and the image spatial nonuniformity is decreased from 27% to 5%. Conclusions: The results suggest that the proposed method is promising for clinical applications. [ABSTRACT FROM AUTHOR]

Objective: A robust and general single-scan NMR method, SGEN-J, is proposed for real-time recording high-resolution two-dimensional (2D) homonuclear J-resolved spectra under inhomogeneous magnetic fields. Methods: This proposed NMR method is designed based on the combination of a selective gradient encoding module to encode chemical shifts with spatial positions, and a J-modulation decoding module to reveal encoded structural information. Multi-band SGEN-J is further implemented to effectively enhance spectral sensitivity with a sustained tolerance of field inhomogeneity. Results: The SGEN-J provides an effective way to rapidly recover chemical shifts, J coupling constants, and multiplet patterns under inhomogeneous magnetic fields. Experiments on various chemical solutions were performed to demonstrate the feasibility and effectiveness of SGEN-J. Experiments on pig marrow tissues were performed to further investigate the applicability of SGEN-J to biological samples with intrinsic susceptibility variations. Conclusion: Based on intrinsic advantages, SGEN-J serves as a helpful complement to existing 2D J-resolved methodologies in molecular structure elucidation and biomedical study, and offer bright perspectives for real-time analyzing in vivo biological systems and monitoring in situ chemical reactions. [ABSTRACT FROM AUTHOR]

The single-scan setup of terrestrial laser scanning of a forest field plot has advantages compared to the multi-scan setup: the speed of operation and that there is no need of a co-registration of the different scans. However in a single-scan setup some of the trees are shaded by others and therefore not detected in the scan. A field inventory solution must take this fact into account. This simulation study shows how different plot sizes and tree stand densities influence the stem visibility giving nonlinear effects especially for large trees and high stem numbers. These effects can be counteracted by using an edge or center stem point detection criteria when analyzing the results or by weighting the detected trees by their visibility. It is shown that the stem density and diameter distribution can be estimated from the visible areas of the plot in case the stem positions are Poisson distributed. [ABSTRACT FROM AUTHOR]

Powder bed additive manufacturing technologies gained much attention in past years not only thanks to design freedom but also because of the peculiar microstructures and mechanical properties that can be obtained thanks to the extremely high cooling rate. However the phenomena that arise during the laser scanning are not yet deeply understood. In this work the effect of the main building parameters and of powder properties on the shape, the microstructure and the properties of Al-based LPBF single scan tracks was evaluated. The experiments were carried out with three different powders in order to understand of the effect of the material thermo-physical properties on the consolidation phenomena. [ABSTRACT FROM AUTHOR]

Objective: A method is proposed to obtain high-resolution 2-D $J$-resolved nuclear magnetic resonance (NMR) spectra in inhomogeneous magnetic fields. Methods: The proposed experiment enables the acquisition of an entire 2-D spectrum in a single scan by utilizing intermolecular double-quantum coherences and the spatial encoding of NMR observables. Results: Chemical shifts, $J$ coupling constants, and multiplet patterns are recovered even when field inhomogeneities are severe enough to completely obscure conventional NMR spectra. After intentional deshimming to yield inhomogeneous magnetic fields, the method was demonstrated on ethyl 3-bromoproprionate in acetone and on a complex mixture of organic compounds. To illustrate the technique's applicability to biological samples with intrinsic magnetic field inhomogeneities arising from macroscopic magnetic susceptibility variations, we performed the experiment on a pig bone marrow sample. Conclusion: Our results show that the new method is a fast and effective tool for studying complex chemical mixtures and biological tissues. Significance: The method could potentially be useful for real-time in vivo NMR studies. [ABSTRACT FROM AUTHOR]

Ambient ionization mass spectrometry has significantly improved the efficiency of analysis complex matrix sample due to its high sensitivity, selectivity and throughput. At present, direct ionization sources coupled with mass spectrometer including desorption electrospray ionization (DESI), real time online (DART), matrix assisted laser desorption ionization (MALDI), laser ablation electrospray ionization (LAESI), desorption atmospheric pressure chemical ionization (DAPCI), extractive electrospray ionization (EESI) etc. are applied for the direct ionization targeting molecular followed by mass spectrometer characterization. A famous ionization technique namely DESI is the most representative ambient source, which can ionization the polar compounds with bulk solid surface focused on a large number of studies on the detection methods of explosives. However, DESI in the ionization of solid explosives is needed continuous scanning and a single sampling area can not exceeding 1 cm2, resulting in time consuming and inaccurate enough results. In order to further improve the analysis rate of the large surface sample and decrease the number of scanning for a given sample surface, a novel mass spectrometry method with a single scan was established for detecting trace substance distributed in large sample surface of any position. Using artificial leather surface (length of a side: 4 cm×4 cm) added lysine and royal demolition explosive (RDX) as representative detection object, the triangular metal copper electrode (length of a side: 8.6 cm) which was applied the ionization regent with methanol-water (3∶7, V/V) was closed to the sample surface, making the tip of the triangle metal copper electrode on the mass spectrometer entrance. The trace substance form into ions in triangle electrode tip towards mass spectrometry when applying +5.8 kV high voltage on the metal copper electrode. This experimental results show that the novel method with a single scan can detect randomly and non-uniform distributed on the surface of the leather sample of lysine and/or RDX at any position, providing the speed for a single sample analysis within 2 s, the limit of detection (LOD) of 6.2×10-7 μg/cm2. compared with analyzing speeding on desorption electrospray ionization mass spectrometry (single sampling area less than 1 cm2), the analyzing speed of the established method is 1000 times than DESI. Overall, this method can provide a promising analytical tool for advanced studies on monitoring of trace explosive, the identification of the food quality and the products in the import and export trade, and the pharmacokinetics of drug metabolism in vivo. [ABSTRACT FROM AUTHOR]

Standard diffusion NMR measurements require the repetition of the experiment multiple times with varying gradient strength or diffusion delay. This makes the experiment time-consuming and restricts the use of hyperpolarized substances to boost sensitivity. We propose a novel single-scan diffusion experiment, which is based on spatial encoding of two-dimensional data, employing the spin-echoes created by two successive adiabatic frequency-swept chirp π pulses. The experiment is called ultrafast pulsed-field-gradient spin-echo (UF-PGSE). We present a rigorous derivation of the echo amplitude in the UF-PGSE experiment, justifying the theoretical basis of the method. The theory reveals also that the standard analysis of experimental data leads to a diffusion coefficient value overestimated by a few per cent. Although the overestimation is of the order of experimental error and thus insignificant in many practical applications, we propose that it can be compensated by a bipolar gradient version of the experiment, UF-BP-PGSE, or by corresponding stimulated-echo experiment, UF-BP-pulsed-field-gradient stimulated-echo. The latter also removes the effect of uniform background gradients. The experiments offer significant prospects for monitoring fast processes in real time as well as for increasing the sensitivity of experiments by several orders of magnitude by nuclear spin hyperpolarization. Furthermore, they can be applied as basic blocks in various ultrafast multidimensional Laplace NMR experiments. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Signature‐based authentication is used often to authenticate hardware intellectual property (IP) when it is reused on a plug‐and‐play system‐on‐chip. A signature embedded in the functional/test component of a hardware IP can easily be verified as it can be generated and observed as functional/scan output of the hardware IP for a certain input key vector. An existing scan‐based approach for embedding signature inserts signature through reordering of scan cells in a single scan (SS) chain. However, it is not applicable to the recent reconfigurable scan architectures having reduced test application time. We propose a scheme for embedding two distinct signatures separately in a reconfigurable scan architecture and verifying those without conflict from the packaged chip by using two distinct test modes of the reconfigurable architecture: namely, scan tree mode and SS mode. The two signatures may include one from logic IP source and the other from physical IP source. The overhead in both routing and power has been minimised in our scheme. Experimental results on design overhead and robustness for ISCAS89 benchmarks are very encouraging. [ABSTRACT FROM AUTHOR]

Abstract: Two-dimensional (2D) NMR spectroscopy shows strong vitality and unsubstitutable significance among NMR techniques. In many cases, however, it is virtually impossible to obtain high-resolution 2D spectra in inhomogeneous fields. Furthermore, conventional 2D NMR spectroscopy suffers from long acquisition time. In this paper, two new pulse sequences tracking the differences of the precession frequencies of two coupled spins are proposed to ultrafast achieve high-resolution 2D correlation spectroscopy (COSY and TOCSY) in inhomogeneous fields in a single scan. The spectral width of the indirect dimension can be reduced to improve the spectral resolution without loss of the correlative information for reconstructing the COSY and TOCSY spectra with mathematical manipulations. The theoretical analysis was given and experiments were performed to verify theoretical predictions. The results show that the proposed sequences can give correct 2D COSY and TOCSY spectra if the field inhomogeneity is linear along the orientation of encoding and decoding gradients. [Copyright &y& Elsevier]

This paper presents a novel attempt at combining the mobile mapping mode and a multiecho-recording laser scanner, as well as a new methodology based on the resulting single-scan point clouds, for enhancing the integrity of individual tree crown reconstruction. The motive stemmed from the widespread but hard-to-reach demand in precision forestry, i.e., efficiently acquiring the integral 3-D structures of single crowns via single-scan light detection and ranging (LiDAR) surveys. For this task, aerospace and aerial LiDAR is generally subject to low sampling density, and static terrestrial LiDAR is restricted to high relocation cost. As a state-of-the-art mapping technology, mobile laser scanning (MLS) can somehow overcome these limitations owing to its strengths of high sampling density and moving efficiency. However, its laser emissions, even from the incorporated peculiar scanner, still suffer from leaf/branch occlusions. To address this challenge, mirroring the half crowns facing the MLS system to the other sides can be assumed as a solution strategy, in a point of view different from typically strengthening laser transmission penetrability. In the case of no multiscans available, this plan turns out to be unstable due to the shortage of reference data. For this issue, this study further expands the roles of multiechoes beyond penetration, namely, also as the self-indicators for correcting the mirrored half crowns. Quantitative evaluation about the integrity of reconstruction in terms of crown outer surface was conducted based on the sample trees, which were measured by the multiecho-recording MLS and a static terrestrial LiDAR from two opposite sides. The promising results basically validated the proposed technique. [ABSTRACT FROM AUTHOR]

Abstract: Current single-shot diffusion methods based on magnetization gratings suffer from low sensitivity due to small rf tip angles and, consequently, from inefficient use of the total equilibrium magnetization. Here, we propose and illustrate the use of a slightly modified form of the magnetization encoding scheme OUFIS for single-shot diffusion experiments. In a detailed theoretical and experimental analysis, we compare the performance of the proposed method to other encoding schemes such as the one-phase or two-phase DANTE and conclude that the OUFIS-based experiment is a superior one. The primary reason is that this scheme allows one to use a larger total pulse area. Hence, one can encode a far larger portion of the initial magnetization into a frequency grating before the onset of various nonlinear effects. In the experimental illustration, we present a single-shot measurement of multicomponent diffusion. [Copyright &y& Elsevier]

Purpose: X-ray scatter results in a significant degradation of image quality in computed tomography (CT), representing a major limitation in cone-beam CT (CBCT) and large field-of-view diagnostic scanners. In this work, a novel scatter estimation and correction technique is proposed that utilizes peripheral detection of scatter during the patient scan to simultaneously acquire image and patient-specific scatter information in a single scan, and in conjunction with a proposed compressed sensing scatter recovery technique to reconstruct and correct for the patient-specific scatter in the projection space. Methods: The method consists of the detection of patient scatter at the edges of the field of view (FOV) followed by measurement based compressed sensing recovery of the scatter through-out the projection space. In the prototype implementation, the kV x-ray source of the Varian TrueBeam OBI system was blocked at the edges of the projection FOV, and the image detector in the corresponding blocked region was used for scatter detection. The design enables image data acquisition of the projection data on the unblocked central region of and scatter data at the blocked boundary regions. For the initial scatter estimation on the central FOV, a prior consisting of a hybrid scatter model that combines the scatter interpolation method and scatter convolution model is estimated using the acquired scatter distribution on boundary region. With the hybrid scatter estimation model, compressed sensing optimization is performed to generate the scatter map by penalizing the L1 norm of the discrete cosine transform of scatter signal. The estimated scatter is subtracted from the projection data by soft-tuning, and the scatter-corrected CBCT volume is obtained by the conventional Feldkamp-Davis-Kress algorithm. Experimental studies using image quality and anthropomorphic phantoms on a Varian TrueBeam system were carried out to evaluate the performance of the proposed scheme. Results: The scatter shading artifacts were markedly suppressed in the reconstructed images using the proposed method. On the Catphan©504 phantom, the proposed method reduced the error of CT number to 13 Hounsfield units, 10% of that without scatter correction, and increased the image contrast by a factor of 2 in high-contrast regions. On the anthropomorphic phantom, the spatial nonuniformity decreased from 10.8% to 6.8% after correction. Conclusions: A novel scatter correction method, enabling unobstructed acquisition of the high frequency image data and concurrent detection of the patient-specific low frequency scatter data at the edges of the FOV, is proposed and validated in this work. Relative to blocker based techniques, rather than obstructing the central portion of the FOV which degrades and limits the image reconstruction, compressed sensing is used to solve for the scatter from detection of scatter at the periphery of the FOV, enabling for the highest quality reconstruction in the central region and robust patient-specific scatter correction. [ABSTRACT FROM AUTHOR]