gebhart/patrepeval huggingface dataset:
High Gain Frequency Domain Optical Parametric Amplification (2015)

The powerful technique of optical parametric amplification (OPA) experienced a huge advance with the invention of optical parametric chirped pulse amplification (OPCPA) and later noncollinear OPA. In this paper, we describe a radically different approach of performing parametric interaction in the frequency domain instead of the time domain. The frequency domain is reached via optical Fourier transformation, which provides a separation ansatz. It allows breaking down a big task into smaller ones which ultimately enables simultaneous up-scaling of peak power and bandwidth. The first proof-of-concept experiment yielding 1.4 mJ, two cycle pulses at 1.8-μm wavelength is complemented by a high gain (>2000) setup at 800-nm wavelength with 2.5 kHz repetition rate. A very low amount of parasitic superfluorescence without degradation of the picosecond pulse contrast within the pump pulse duration has been observed upon high gain conditions.
A low power 16-bit Booth Leapfrog array multiplier using Dynamic Adders (2004)

We propose a 16-bit Booth Leapfrog array multiplier with low voltage (1.1 V), low power dissipation (10.8 /spl mu/W/MHz) and relatively high-speed (64 ns) operation. We achieve these attributes in two ways. First, we employ our proposed low hardware complexity Dynamic Adders (DAs) where their Sum and Carry outputs are obtained at different rates and the DAs are used to reduce the spurious switching in the multiplier. Second, we place most of these DAs in a Leapfrog array structure (in the first stage adder array) and employ a high-speed Manchester Carry Look-Ahead (CLA) adder as the Carry Propagation Adder (CPA). The proposed multiplier features the lowest power dissipation, one of the shortest delays, resulting in the lowest Power-Delay-Product (PDP) when compared to reported designs. The proposed multiplier is suitable for power- and IC area-critical applications such as a hearing instrument.
An interferometer for atoms. (1991)

We have demonstrated an interferometer for atoms. A three-grating geometry is used, in which the interfering beams are distinctly separated in both position and momentum. We used a highly collimated beam of sodium atoms with a de Broglie wavelength of 16 pm and high-quality 0.4-\ensuremath{\mu}m-period free-standing gratings which we fabricated using a novel method. The interference signal is 70 counts/s, which allows us to determine the phase to 0.1 rad in 1 min. Applications of atom interferometers are briefly discussed.
SIFT-Based Image Compression (2012)

This paper proposes a novel image compression scheme based on the local feature descriptor - Scale Invariant Feature Transform (SIFT). The SIFT descriptor characterizes an image region invariantly to scale and rotation. It is used widely in image retrieval. By using SIFT descriptors, our compression scheme is able to make use of external image contents to reduce visual redundancy among images. The proposed encoder compresses an input image by SIFT descriptors rather than pixel values. It separates the SIFT descriptors of the image into two groups, a visual description which is a significantly sub sampled image with key SIFT descriptors embedded and a set of differential SIFT descriptors, to reduce the coding bits. The corresponding decoder generates the SIFT descriptors from the visual description and the differential set. The SIFT descriptors are used in our SIFT-based matching to retrieve the candidate predictive patches from a large image dataset. These candidate patches are then integrated into the visual description, presenting the final reconstructed images. Our preliminary but promising results demonstrate the effectiveness of our proposed image coding scheme towards perceptual quality. Our proposed image compression scheme provides a feasible approach to make use of the visual correlation among images.
Recent Advances in Gaseous Detection Modes in the ESEM (1999)

Abstract The Environmental Scanning Electron Microscope, or ESEM, is the only class of SEM that can image in a gaseous environment that will maintain a sample in a fully wet state. The use of the patented Gaseous Secondary Electron Detector, or GSED, which amplifies the secondary electron signal with the gas, has allowed the ESEM to image a multitude of samples with true secondary contrast. Recently, several new modes of imaging in a gas have been developed and will allow further expansion of the capabilities of the ESEM. To maintain pressures in the ESEM up to 20 Torr (27 mbar), the use of multiple, differentially pumped apertures, is required. This can place a restriction on the low magnification range. In the large field detection mode, all magnification restrictions are removed. Magnifications as low as lOx may be achieved. This is similar to many conventional SEMs.
A new algorithm for detecting central apnea in neonates (2011)

Apnea of prematurity is an important and common clinical problem, and is often the rate-limiting process in NICU discharge. Accurate detection of episodes of clinically important neonatal apnea using existing chest impedance (CI) monitoring is a clinical imperative. The technique relies on changes in impedance as the lungs fill with air, a high impedance substance. A potential confounder, however, is blood coursing through the heart. Thus, the cardiac signal during apnea might be mistaken for breathing. We report here a new filter to remove the cardiac signal from the CI that employs a novel resampling technique optimally suited to remove the heart rate signal, allowing improved apnea detection. We also develop an apnea detection method that employs the CI after cardiac filtering. The method has been applied to a large database of physiological signals, and we prove that, compared to the presently used monitors, the new method gives substantial improvement in apnea detection.
Optimal Design of Sulfidated Nanoscale Zerovalent Iron for Enhanced Trichloroethene Degradation (2018)

Sulfidated nanoscale zerovalent iron (S-nZVI) has the potential to be a cost-effective remediation agent for a wide range of environmental pollutants, including chlorinated solvents. Various synthesis approaches have yielded S-nZVI consisting of a Fe<sup>0</sup> (or Fe<sup>0</sup>/S<sup>0</sup>) core and FeS shell, which are significantly more reactive to trichloroethene (TCE) than nZVI. However, their reactivity is not as high as palladium-doped nZVI (Pd-nZVI). We synthesized S-nZVI by the co-precipitation of FeS and Fe<sup>0</sup> by using Na<sub>2</sub>S during the borohydride reduction of FeSO<sub>4</sub> (S-nZVI<sub>co</sub>). This resulted in FeS structures bridging the nZVI core and the surface, as confirmed by electron microscopy and X-ray analyses. The TCE degradation capacity of up to 0.46 mol TCE/mol Fe<sup>0</sup> was obtained for S-nZVI<sub>co</sub> at a high S loading and was comparable to Pd-nZVI but 60% higher than the currently most reactive S-nZVI, in which FeS only coats the nZVI (S-nZVI<sub>post</sub>). The high TCE degradation was due to complete utilization of Fe<sup>0</sup> (2 e<sup>-</sup>/mol Fe<sup>0</sup>) toward the formation of acetylene. Although Pd-nZVI yielded 3 e<sup>-</sup>/mol Fe<sup>0</sup>, TCE degradation was comparable because it reduced acetylene further to ethene and ethane. Under Fe<sup>0</sup>-limited conditions, the S-nZVI<sub>co</sub> TCE degradation rate was 16 times higher than that of Pd-nZVI (0.5 wt % Pd) and 90 times higher than that of S-nZVI<sub>post</sub>.
Efficient LCA based keyword search in xml data (2007)

Keyword search in XML documents based on the notion of lowest common ancestors (LCAs) and modifications of it has recently gained research interest [2, 3, 4]. In this paper we propose an efficient algorithm called Indexed Stack to find answers to keyword queries based on XRank's semantics to LCA [2]. The complexity of the Indexed Stack algorithm is O(kd|S1|\log|S|) where k is the number of keywords in the query, d is the depth of the tree and |S1 | (|S|) is the occurrence of the least (most) frequent keyword in the query. In comparison, the best worst case complexity of the core algorithms in [2] is O(kd|S|). We analytically and experimentally evaluate the Indexed Stack algorithm and the two core algorithms in [2]. The results show that the Indexed Stack algorithm outperforms in terms of both CPU and I/O costs other algorithms by orders of magnitude when the query contains at least one low frequency keyword along with high frequency keywords.
Almost Optimal Local Graph Clustering Using Evolving Sets (2016)

Spectral partitioning is a simple, nearly linear time algorithm to find sparse cuts, and the Cheeger inequalities provide a worst-case guarantee for the quality of the approximation found by the algorithm. A local graph partitioning algorithm finds a set of vertices with small conductance (i.e., a sparse cut) by adaptively exploring part of a large graph G , starting from a specified vertex. For the algorithm to be local, its complexity must be bounded in terms of the size of the set that it outputs, with at most a weak dependence on the number n of vertices in G . Previous local partitioning algorithms find sparse cuts using random walks and personalized PageRank [Spielman and Teng 2013; Andersen et al. 2006]. In this article, we introduce a simple randomized local partitioning algorithm that finds a sparse cut by simulating the volume-biased evolving set process , which is a Markov chain on sets of vertices. We prove that for any ϵ > 0, and any set of vertices A that has conductance at most φ, for at least half of the starting vertices in A our algorithm will output (with constant probability) a set of conductance O (√φ /ϵ). We prove that for a given run of the algorithm, the expected ratio between its computational complexity and the volume of the set that it outputs is vol( A ) ϵ φ -1/2 polylog( n ), where vol( A ) = Σ v ∈ A d ( v ) is the volume of the set A . This gives an algorithm with the same guarantee (up to a constant factor) as the Cheeger's inequality that runs in time slightly superlinear in the size of the output. This is the first sublinear (in the size of the input) time algorithm with almost the same guarantee as the Cheeger's inequality. In comparison, the best previous local partitioning algorithm, by Andersen et al. [2006], has a worse approximation guarantee of O (√φ log n ) and a larger ratio of φ -1 polylog( n ) between the complexity and output volume. As a by-product of our results, we prove a bicriteria approximation algorithm for the expansion profile of any graph. For 0 < k ≤ vol( V )/2, let φ( k ) : min S : vol( S ) ≤ k φ( S ). There is a polynomial time algorithm that, for any k , ϵ > 0, finds a set S of volume vol( S ) ≤ O ( k 1 + ϵ ) and expansion φ( S )≤ O (√φ ( k )/ϵ). As a new technical tool, we show that for any set S of vertices of a graph, a lazy t -step random walk started from a randomly chosen vertex of S will remain entirely inside S with probability at least (1 - φ( S )/2) t . This itself provides a new lower bound to the uniform mixing time of any finite state reversible Markov chain.
Time alignment of time of flight positron emission tomography using the background activity of LSO (2013)

Time alignment of a positron emission tomography scanner (PET) is an important calibration as the nature of the data collected in PET is inherently time-correlated. This calibration is a key concern in scanners which employ time-of-flight (TOF) capability to localize events along a particular segment of a line of response. Emission data collected with TOF information requires the time difference measured by the scanner to be tightly coupled to the spatial information such that the true origin of the annihilation event of the radioisotope is colocated in both the time and spatial domains. There are many techniques to time align a PET scanner but all involve an external source. Our research shows that the background radiation of LSO provides an intrinsic source of radiation that can be used to measure and correct the time offsets for detector pixels. The physical distances of the static pixel locations can be compared to the measured time of flight of background events generated by LSO beta decay and cascade gamma traversing the PET field of view. The resulting information can be used to correct for the time offset between a pixel and all other pixels that the originating pixel is in coincidence with. This method can enable system operators to perform continuous time alignment whenever the system is idle, and can reduce personnel radiation exposure by reducing the need to handle sources during the calibration process.
Compressive x-ray material decomposition using structured illumination (2019)

This manuscript explores a new approach for spectral X-ray tomography that uses K-edge filtering structures to attain spectral and spatially coded illumination which enables the acquisition of compressive measurements for the reconstruction of energy-binned images. The system is coined compressive spectral X-ray imaging (CSXI). A multi-stage algorithm is proposed to solve the non-linear ill-posed problem using sparse and low-rank regularization constraints to exploit the structure of the spectral data cube. The proposed algorithm can reconstruct both the energy binned images as well as the material decomposition of the object given a set of basis materials.
Realizing the Commercial Potential of Hierarchical Zeolites: New Opportunities in Catalytic Cracking (2013)

What a cracker! Many approaches to mesoporous zeolites have been reported. The preparation of mesoporous zeolite Y, as the most widely used zeolite in catalysis, its properties, and its application in fluid catalytic cracking (FCC) and hydrocracking are reviewed. Finally, the scale-up and use of mesostrutured zeolite Y on an industrial scale are described, as the first commercial application of hierarchical zeolites.
Acoustic Beamfolding With a Miura-Ori Tessellated Transducer Array (2016)

Vibrating structures radiate acoustic waves into the fluid media which surround them at the structure-fluid interface. Fundamentally, the interfacing structural surface topology governs the amplitude and frequency sensitivities of acoustic energy propagation away from the surface, a characteristic known as directivity. Assembling many planar acoustic transducer elements into arrays is one way to greatly enhance the far-field energy propagation directional sensitivities. Due to the spatially distributed transducers, the travelling waves combine uniquely in phase at an observation point in the far field where large energy focusing or suppressing occurs as a function of the spatial coordinates. The conventional approach to tune planar array directivity for a different purpose or new spectral sensitivity is to actively adjust each array input signal with a controlled phase delay which requires accessory hardware and computational burden. From a different standpoint, structures created from foldable, tessellated architectures, such as origami patterns, can yield enormous topological variation from the simple, kinematic motions of connected planar facets. This observation has inspired recent efforts to develop innovative, adaptable engineering systems using origami tessellations as an architectural basis for design. Considering together the topological sensitivities of planar acoustic arrays and the multifunctionality engendered by folding origami-based structures having planar facets, this research seeks to surmount the limitations of conventional acoustic arrays and explore a new idea for adaptable acoustic systems by integrating principles from acoustics and origami-inspired design. Upon the new idea, this research studies a tessellated acoustic transducer array able to drastically adapt energy guiding capabilities through simple topological folding. An array based on the Miura-ori folding pattern is examined in a new structural-acoustic model to assess the capability of folding to tune the magnitude and spatial variations of acoustic energy propagated to the far field. The acoustic directivity of the array is found to exhibit massive sensitivities based on the excitation frequency and fold angle, giving rise to large amplitude and spatial adaptation of the energy guiding to the far field point. An experimental tessellated acoustic array is fabricated and evaluated to verify the trends predicted by the model. From the measurements, it is conclusively seen that the topological change of the origami-inspired acoustic array empowers straightforward and reversible means for orders of magnitude in change in acoustic energy transmission and steering. Upon this basis, future compact, deployable, and kinematically-adaptable wave energy transmission systems may be developed for applications including field imaging, communications, and long range force projection.
Wide-range thermometer based on the temperature-dependent conductance of planar tunnel junctions (2000)

The effect of the Fermi–Dirac distribution on the current through standard planar tunnel junctions is a suitable basis for thermometry in a wide temperature range. In particular, it extends the range spanned by Coulomb-blockade thermometers up to room temperature.
Slit-Surface Electrospinning: A Novel Process Developed for High-Throughput Fabrication of Core-Sheath Fibers (2015)

In this work, we report on the development of slit-surface electrospinning--a process that co-localizes two solutions along a slit surface to spontaneously emit multiple core-sheath cone-jets at rates of up to 1 L/h. To the best of our knowledge, this is the first time that production of electrospun core-sheath fibers has been scaled to this magnitude. Fibers produced in this study were defect-free (i.e. non-beaded) and core-sheath geometry was visually confirmed under scanning electron microscopy. The versatility of our system was demonstrated by fabrication of (1) fibers encapsulating a drug, (2) bicomponent fibers, (3) hollow fibers, and (4) fibers from a polymer that is not normally electrospinnable. Additionally, we demonstrate control of the process by modulating parameters such as flow rate, solution viscosity, and fixture design. The technological achievements demonstrated in this work significantly advance core-sheath electrospinning towards commercial and manufacturing viability.
Polymorphic Repetitive DNA Sequences in Mycobacterium tuberculosis Detected with a Gene Probe from a Mycobacterium fortuitum Plasmid (1989)

Clinical isolates of Mycobacterium tuberculosis were shown by Southern blotting to contain DNA sequences hybridizing to a probe derived from a Mycobacterium fortuitum plasmid. Two such M. tuberculosis DNA fragments, isolated from a gene library, were used as probes to show restriction fragment length polymorphism in M. tuberculosis strains by detecting a repetitive sequence apparently located at different points on the chromosome. This could indicate the presence of a transposable element in M. tuberculosis which is partly homologous to a region of the M. fortuitum plasmid. The probes described can be used to fingerprint M. tuberculosis isolates, and in addition are capable of distinguishing M. tuberculosis from Mycobacterium bovis and BCG.
Self-Transducing Silicon Nanowire Electromechanical Systems at Room Temperature (2008)

Electronic readout of the motions of genuinely nanoscale mechanical devices at room temperature imposes an important challenge for the integration and application of nanoelectromechanical systems (NEMS). Here, we report the first experiments on piezoresistively transduced very high frequency Si nanowire (SiNW) resonators with on-chip electronic actuation at room temperature. We have demonstrated that, for very thin (~90 nm down to ~30 nm) SiNWs, their time-varying strain can be exploited for self-transducing the devices' resonant motions at frequencies as high as approximately 100 MHz. The strain of wire elongation, which is only second-order in doubly clamped structures, enables efficient displacement transducer because of the enhanced piezoresistance effect in these SiNWs. This intrinsically integrated transducer is uniquely suited for a class of very thin wires and beams where metallization and multilayer complex patterning on devices become impractical. The 30 nm thin SiNW NEMS offer exceptional mass sensitivities in the subzeptogram range. This demonstration makes it promising to advance toward NEMS sensors based on ultrathin and even molecular-scale SiNWs, and their monolithic integration with microelectronics on the same chip.
The obligatory role of Activin A in the formation of heterotopic bone in Fibrodysplasia Ossificans Progressiva (2017)

Fibrodysplasia Ossificans Progressiva (FOP) is a rare genetic disorder that presents at birth with only minor patterning defects, but manifests its debilitating pathology early in life with episodic, yet progressive and cumulative, heterotopic ossification (HO) of ligaments, tendons, and a subset of major skeletal muscles. The resulting HO lesions are endochondral in nature, and appear to be linked to inflammatory stimuli arising in association with known injuries, or from inflammation linked to normal tissue repair. FOP is caused by gain-of-function mutations in ACVR1, which encodes a type I BMP receptor. Initial studies on the pathogenic mechanism of FOP-causing mutations in ACVR1 focused on the enhanced function of this receptor in response to certain BMP ligands, or independently of ligands, but did not directly address the fact that HO in FOP is episodic and inflammation-driven. Recently, we and others demonstrated that Activin A is an obligate factor for the initiation of HO in FOP, signaling aberrantly via mutant ACVR1 to transduce osteogenic signals and trigger heterotopic bone formation (Hatsell et al., 2015; Hino et al., 2015). Subsequently, we identified distinct tissue-resident mesenchymal progenitor cells residing in muscles and tendons that recognize Activin A as a pro-osteogenic signal (solely in the context of FOP-causing mutant ACVR1), and give rise to the cartilaginous anlagen that form heterotopic bone (Dey et al., 2016). During the course of these studies, we also found that the activity of FOP-causing ACVR1 mutations does not by itself explain the triggered or inflammatory nature of HO in FOP, suggesting the importance of other, inflammation-introduced, factors or processes. This review presents a synthesis of these findings with a focus on the role of Activin A and inflammation in HO, and lays out perspectives for future research.
Rapid development of optimized DSP code from a high level description through software estimations (1999)

Generation of optimized DSP code from a high level language such as C is very time consuming since current DSP compilers are generally unable to produce efficient code. We present a software estimation methodology from a C description that helps for a rapid development of DSP applications. Our tool VESTIM provides both a performance evaluation for assembly code generated by the compiler and an estimation of an optimized assembly code. Blocks of applications G.721 and G.728 have been evaluated using VESTIM. Results show that estimations are very accurate and allow software development time to be significantly reduced.