gebhart/patrepeval huggingface dataset:
Learning Data Augmentation with Online Bilevel Optimization for Image\n Classification (2020)

Data augmentation is a key practice in machine learning for improving\ngeneralization performance. However, finding the best data augmentation\nhyperparameters requires domain knowledge or a computationally demanding\nsearch. We address this issue by proposing an efficient approach to\nautomatically train a network that learns an effective distribution of\ntransformations to improve its generalization. Using bilevel optimization, we\ndirectly optimize the data augmentation parameters using a validation set. This\nframework can be used as a general solution to learn the optimal data\naugmentation jointly with an end task model like a classifier. Results show\nthat our joint training method produces an image classification accuracy that\nis comparable to or better than carefully hand-crafted data augmentation. Yet,\nit does not need an expensive external validation loop on the data augmentation\nhyperparameters.\n
Tracking polycrystal evolution non-destructively in 3D by laboratory X-ray diffraction contrast tomography (2020)

The ability to accurately map crystal grain morphology and grain boundaries in polycrystalline materials, non-destructively and in three-dimensions is required for detailed investigations into many aspects of polycrystalline deformation, as well as many other properties. Previously, the laboratory-based X-ray diffraction contrast tomography technique (LabDCT) has been shown to be capable of reconstructing crystallographic orientations and grain centres in 3D. Here we demonstrate the extension of the method to the reconstruction of the individual 3D grain shapes. Firstly, the grain boundaries are mapped by DCT in a beta‑titanium alloy (Ti-β21S) sample and validated by independent measurements of the grain shapes obtained from phase contrast tomography. The independent validation measurements show that the boundaries can be located with a mean accuracy of 4.4 μm. Secondly, the grain locations and orientations in a copper powder sample sintered at 1050 °C are tracked over time in a time-lapse manner by LabDCT and then the final state compared and validated against destructive serial sectioning EBSD (3D-EBSD) post-mortem. In this case we are able to follow the recrystallisation and competitive grain growth over time, by visualising the migration of selected grain boundaries. In particular the shrinkage and dissolution of grains in the immediate vicinity of a fast-growing grain are observed and quantified in the light of changes in misorientation relationships with the growing grain. More generally, LabDCT can be used to characterise, track or establish realistic 3D image-based models of polycrystalline microstructures across a range of crystal structures.
Ultrasonic/sonic driller/corer (USDC) as a sampler for planetary exploration (2002)

Future NASA exploration missions to Mars, Europa, Titan, comets, and asteroids will perform sampling, in-situ analysis and possibly the return of material to Earth for further tests. One of the major limitations of sampling in low gravity environments is that conventional drills need high axial force. An ultrasonic/sonic driller/corer (USDC) mechanism was developed to address these and other limitations of existing drilling techniques. The USDC is based on an ultrasonic horn that is driven by a piezoelectric stack. The horn drives a free-mass, which resonates, between the horn and drill stem. Tests have shown that this device addresses some of the key challenges to the NASA objective of planetary in-situ sampling and analysis. The USDC is lightweight (450 g), requires low pre-load (<5N) and can be driven at low power (5 W). The device was operated from such robotic platforms as the Sojourner rover and the FIDO robotic arm and it has been shown to drill various rocks including granite, diorite, basalt and limestone. The drill can potentially operate at high and low temperatures and does not require sharpening. Although the drill is driven electrically at 20 kHz, a substantial subharmonic acoustic component is found that is crucial to drilling performance. Models that explain this low frequency coupling in the horn, free-mass, drill stem and rock are presented. Efforts are currently underway to integrate the models and experimentally corroborate the predictions.
Revolver and Superior: Novel Transposon-Like Gene Families of the Plant Kingdom (2009)

High-throughput sequencing of eukaryotic genomes has revived interest in the structure and function of repetitive genomic sequences, previously referred to as junk DNA. Repetitive sequences, including transposable elements, are now believed to play a significant role in genomic differentiation and evolution. Some are also expressed as regulatory noncoding RNAs. Vast DNA databases exist for higher eukaryotes; however, with the exception of homologues of known repetitive-sequence-families and transposable elements, most repetitive elements still need to be annotated. Revolver and Superior, both discovered in the Triticeae, are novel classes of transposon-like genes and major components of large cereal genomes. Revolver was isolated from rye via genome subtraction of sequences common to rye and wheat. Superior was isolated from rye by cleavage with EcoO109I, the recognition sites of which consist of a 5'- PuGGNCCPy-3' multi-sequence. Revolver is 2929-3041 bp long with an inverted repeat sequence on each end. The Superior family elements are 1292-1432 bp in length, with divergent 5' regions, indicating the presence of considerable structural diversity. Revolver and Superior are transcriptionally active elements; Revolver harbors a single gene consisting of three exons and two introns, encoding a protein of 139 amino acid residues. Revolver variants range in size from 2665 bp to 4269 bp, with some variants lacking the 5' region, indicating structural diversity around the first exon. Revolver and Superior are dispersed across all seven chromosomes of rye. Revolver has existed since the diploid progenitor of wheat, and has been amplified or lost in several species during the evolution of the Triticeae. This article reviews the recently discovered Revolver and Superior families of plant transposons, which do not share identity with any known autonomous transposable elements or repetitive elements from any living species.
Electrically and Thermally Triggered Three-Dimensional Graphene-Foam-Reinforced Shape Memory Epoxy Composites (2023)

Shape memory polymer (SMP) epoxy composites have attracted significant attention due to their easy processing, lightweight nature, and ability to recover strain. However, their limited recovery rate and inferior mechanical properties have hindered their functional applications. This research explores the potential of three-dimensional (3D) graphene foam (GrF) as a highly efficient reinforcement for SMP epoxy composites. We demonstrated that the incorporation of a mere 0.13 wt.% GrF into mold-cast SMP epoxy leads to a 19% increase in the glass transition temperature (T<sub>g</sub>). To elucidate the reinforcing mechanism, we fabricated and extensively analyzed composites with varying weight percentages of GrF. The GrF-based SMP epoxy composite exhibits a 57% increase in thermal conductivity, measuring 0.296 W mK<sup>-1</sup> at 70 °C, due to the interconnected 3D graphene network within the matrix. Notably, this composite also demonstrates remarkable electrical conductivity, making it suitable for dual-triggering applications. The GrF-SMP epoxy composite achieves a maximum shape recovery ratio and a significant 23% improvement in the recovery rate, effectively addressing the issue of slow recovery associated with SMPs. We investigated the effect of switching temperatures on the shape recovery rate. We identified the optimal triggering temperature to initiate shape recovery for epoxy SMP and GrF-epoxy SMP as thermal energy equivalent to T<sub>g</sub> + 20 °C. Additionally, we fabricated a bird-shaped composite using GrF reinforcement, which showcases self-healing capabilities through the crack opening and closure and serves as a tangible demonstration of the transformative potential of the composite. These GrF-epoxy SMP composites, responsive to stimuli, hold immense promise for diverse applications, such as mechanical systems, wearable sensors, morphing wings, foldable robots, and antennas.
Improved Hard Iterative Decoding (IHID) of Multilevel Codes (2013)

An improved hard iterative decoding (IHID) algorithm is presented to efficiently terminate hard iterations in the decoding of multi-level codes. The proposed terminating policy stops iterations as soon as a valid path on the super trellis is found thereby only running the minimum required number of iterations. The IHID decoding algorithm performs better than the conventional multi-stage decoding by reducing the effects of error multiplicity. Compared with known hard iterative decoding with fixed number of iterations, the IHID algorithm can significantly reduce decoding complexity and decoding delay.
A Species-Specific Strategy for the Identification of Hemocoagulase Agkistrodon halys pallas Based on LC-MS/MS-MRM (2022)

Hemocoagulase <i>Agkistrodon halys pallas</i> is a complex mixture composed of snake venom thrombin-like enzymes (svTLEs) and small amounts of thrombokinase-like enzymes. It has been widely used as a hemostatic with rapidly growing marketing due to its advantage of localized clotting fibrinogen other than systemic coagulation. However, svTLEs from different species have various structures, functions, and hemostatic mechanisms. To ensure the efficacy and safety of Hemocoagulase <i>Agkistrodon halys pallas</i>, an exclusive and sensitive method has been developed to identify specific marker peptides based on liquid chromatography-tandem mass spectrometry with multiple reaction monitoring (LC-MS/MS-MRM) mode. By combining transcriptomics and proteomics, a series of species-specific peptides of <i>Agkistrodon halys pallas</i> were predicted and examined by LC-MS/MS. After reduction, alkylation, and tryptic digestion were performed on Hemocoagulase <i>Agkistrodon halys pallas</i>, a target peptide TLCAGVMEGGIDTCNR was analyzed by LC-MS/MS-MRM. It offers a new and effective approach for the quality control of Hemocoagulase <i>Agkistrodon halys pallas</i> products. This method is superior to the current assays in terms of sensitivity, specificity, precision, accuracy, and throughput. The strategy can also be applied in studying other important protein-based medicines.
Industrializing a Bacterial Strain for <scp>l</scp>-Serine Production through Translation Initiation Optimization (2019)

Turning a proof-of-concept synthetic biology design into a robust, high performing cell factory is a major time and money consuming task, which severely limits the growth of the white biotechnology sector. Here, we extend the use of tunable antibiotic resistance markers for synthetic evolution (TARSyn), a workflow for screening translation initiation region (TIR) libraries with antibiotic selection, to generic pathway engineering, and transform a proof-of-concept synbio design into a process that performs at industrially relevant levels. Using a combination of rational design and adaptive evolution, we recently engineered a high-performing bacterial strain for production of the important building block biochemical l-serine, based on two high-copy pET vectors facilitating expression of the serine biosynthetic genes <i>serA</i>, <i>serC</i>, and <i>serB</i> from three independent transcriptional units. Here, we prepare the bacterial strain for industrial scale up by transferring and reconfiguring the three genes into an operon encoded on a single low-copy plasmid. Not surprisingly, this initially reduces production titers considerably. We use TARSyn to screen both experimental and computational optimization designs resulting in high-performing synthetic serine operons and reach industrially relevant production levels of 50 g/L in fed-batch fermentations, the highest reported so far for serine production.
Electrocorticography-based brain computer Interface-the seattle experience (2006)

Electrocorticography (ECoG) has been demonstrated to be an effective modality as a platform for brain-computer interfaces (BCIs). Through our experience with ten subjects, we further demonstrate evidence to support the power and flexibility of this signal for BCI usage. In a subset of four patients, closed-loop BCI experiments were attempted with the patient receiving online feedback that consisted of one-dimensional cursor movement controlled by ECoG features that had shown correlation with various real and imagined motor and speech tasks. All four achieved control, with final target accuracies between 73%-100%. We assess the methods for achieving control and the manner in which enhancing online control can be accomplished by rescreening during online tasks. Additionally, we assess the relevant issues of the current experimental paradigm in light of their clinical constraints.
Electrical-Impedance-Based Ice-Thickness Gauges (2003)

Langley Research Center has developed electrical-impedance-based ice-thickness gauges and is seeking partners and collaborators to commercialize them. When used as parts of active monitoring and diagnostic systems, these gauges make it possible to begin deicing or to take other protective measures before ice accretes to dangerous levels. These gauges are inexpensive, small, and simple to produce. They can be adapted to use on a variety of stationary and moving structures that are subject to accumulation of ice. Examples of such structures include aircraft, cars, trucks, ships, buildings, towers, power lines (see figure), power-generating equipment, water pipes, freezer compartments, and cooling coils. A gauge of this type includes a temperature sensor and two or more pairs of electrically insulated conductors embedded in a surface on which ice could accumulate. The electrical impedances of the pairs of conductors vary with the thickness of any ice that may be present. Somewhat more specifically, when the pairs of conductors are spaced appropriately, the ratio between their impedances is indicative of the thickness of the ice. Therefore, the gauge includes embedded electronic circuits that measure the electrical impedances, plus circuits that process the combination of temperature and impedance measurements to determine whether ice is present and, if so, how thick it is. Of course, in the processing of the impedance measurements, the temperature measurements help the circuitry to distinguish between liquid water and ice. The basic design of a gauge of this type can be adapted to local conditions. For example, if there is a need to monitor ice over a wide range of thickness, then the gauge can include more than two sets of conductors having various spacings.
PHOTOISOMERIZATION OF 7-SUBSTITUTED NORBORNADIENE-CYCLODEXTRIN INCLUSION COMPLEXES (1985)

Abstract The photoisomerization of 7-substituted norbornadiene-cyclodextrin inclusion complexes, in which the substituents are t-butoxyl, acetoxyl, and hydroxyl groups, gave 7-substituted quadricyclene-cyclodextrin inclusion complexes.
Design considerations for effective thermal management in mobile nanotweezers (2019)

Controlled manipulation of nanoscale objects in fluids is relevant to both fundamental studies and advances in nanotechnology. While standard techniques of nanomanipulation, such as optical and plasmonic tweezers have limitations in simultaneous trapping and transport of nanoscale cargo, magnetically driven plasmonic nanorobots under optical illumination provide a promising solution. These so called mobile nanotweezers[1] (MNT) use strongly localized electromagnetic field near plasmonic nanostructures to trap objects with high efficiency and can simultaneously be driven by magnetic fields to selectively trap, transport and release colloidal cargo. Upon illumination, apart from gradient forces due to local electric field enhancement, additional forces arise from heating generated by absorption of light. Here, we present a method to understand and engineer the thermally induced forces in mobile nanotweezers. The temperature enhancement and associated thermofluidic forces are studied as a function of MNT geometry. Illumination slightly detuned from plasmon resonance frequency produces sufficient field enhancement with negligible generation of heat, and therefore much reduced thermophoretic and convective forces. This allowed us to engineer thermoplasmonic forces in MNTs for enhanced trapping performance.
Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes (2008)

The objective of the proposed work was to develop the fundamental understanding and practical techniques for enhancement of Phosphorescent Organic Light Emitting Diodes (PhOLEDs) performance by utilizing radiative decay control technology. Briefly, the main technical goal is the acceleration of radiative recombination rate in organometallic triplet emitters by using the interaction with surface plasmon resonances in noble metal nanostructures. Increased photonic output will enable one to eliminate constraints imposed on PhOLED efficiency by triplet-triplet annihilation, triplet-polaron annihilation, and saturation of chromophores with long radiative decay times. Surface plasmon enhanced (SPE) PhOLEDs will operate more efficiently at high injection current densities and will be less prone to degradation mechanisms. Additionally, introduction of metal nanostructures into PhOLEDs may improve their performance due to the improvement of the charge transport through organic layers via multiple possible mechanisms ('electrical bridging' effects, doping-like phenomena, etc.). SPE PhOLED technology is particularly beneficial for solution-fabricated electrophosphorescent devices. Small transition moment of triplet emitters allows achieving a significant enhancement of the emission rate while keeping undesirable quenching processes introduced by the metal nanostructures at a reasonably low level. Plasmonic structures can be introduced easily into solution-fabricated PhOLEDs by blending and spin coating techniques and can be used for enhancement of performance in existing device architectures. This constitutes a significant benefit for a large scale fabrication of PhOLEDs, e.g. by roll-to-roll fabrication techniques. Besides multieexciton annihilation, the power efficacy of PhOLEDs is often limited by high operational bias voltages required for overcoming built-in potential barriers to injection and transport of electrical charges through a device. This problem is especially pronounced in solution processed OLEDs lacking the accuracy and precision of fabrication found in their small molecule counterparts. From this point of view, it seems beneficial to develop materials allowing reduction of the operation bias voltage via improvement of the charge injection. The materials sought have to be compatible with solution-based fabrication process and allow easy incorporation of metal nanostructures.
Deposition and properties of optical oxide coatings from polymerized solutions (1982)

Oxide films ranging in thickness from less than a hundred angstroms to several thousand angstroms may be deposited from clear solutions derived from metal-organic compounds. These solutions contain oxide constituents in a soluble polymerized form and deposit a glasslike film upon application on substrates. A bake temperature of 300-500 degrees C is required to reduce these film into a pure oxide state. The properties of the resultant oxide films are process dependent. In this paper, parameters that affect the optical properties of oxide films deposited from polymerized solution are identified, and their specific effects are described. The parameters include: type of solution; nature of substrate; drying conditions; and heat treatment atmosphere and temperature.
Batteries for Efficient Energy Extraction from a Water Salinity Difference (2011)

The salinity difference between seawater and river water is a renewable source of enormous entropic energy, but extracting it efficiently as a form of useful energy remains a challenge. Here we demonstrate a device called "mixing entropy battery", which can extract and store it as useful electrochemical energy. The battery, containing a Na(2-x)Mn(5)O(10) nanorod electrode, was shown to extract energy from real seawater and river water and can be applied to a variety of salt waters. We demonstrated energy extraction efficiencies of up to 74%. Considering the flow rate of river water into oceans as the limiting factor, the renewable energy production could potentially reach 2 TW, or ∼13% of the current world energy consumption. The mixing entropy battery is simple to fabricate and could contribute significantly to renewable energy in the future.
Integrated optical differential amplifier with large dynamic range for gigahertz bandwidth electrical signals (1991)

An optoelectronic differential amplifier for gigahertz-bandwidth electrical signals using fiber optics and integrated optical devices is presented. In the amplifier presented the signal subtraction is done while still in the optical domain. The differential gain is a function of the electrical-to-optical and optical-to-electrical conversion factors. The common-mode rejection ratio of the differential amplifier at 1 GHz is greater than 30 dB. The common-mode rejection ratio depends on the time difference between the differential amplifier inputs. This device could be used as an integrated module in radar and communications systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Wire Crimp Connectors Verification using Ultrasonic Inspection (2007)

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.
DNA guided assembly of well-organized nano-architectures. (2008)

Incorporation of DNA into nano-object design provides a unique opportunity to establish highly selective and reversible interactions between the components of nanosystems. Assembly approaches based on the nanoobject’s addressability promise powerful routes for creation of rationally designed nano-systems for the development of novel magnetic, photonic and plasmonic metamaterials. DNA provides a powerful platform due its unique recognition capabilities, mechanical and physicochemical stability, and synthetic accessibility of practically any desired nucleotide sequences. Recently, strategies based on DNA programmability for a pre-designed placement of nanoparticles in one- and two-dimensions using scaffolds have been demonstrated [1, 2]. However, in three dimensions, where theory predicted a rich phase behavior[3, 4], experimental realization has remained elusive[5], with nanoscale systems forming amorphous aggregates.