gebhart/patrepeval huggingface dataset:
Nucleophilic Perfluoroalkylation of Imines and Carbonyls: Perfluoroalkyl Sulfones as Efficient Perfluoroalkyl-Transfer Motifs (2010)

Alkoxide-induced nucleophilic pentafluoroethylation and trifluoromethylation of aldehydes, ketones, and imines using pentafluoroethyl phenyl sulfone (PhSO(2)CF(2)CF(3), 1) and trifluoromethyl phenyl sulfone (PhSO(2)CF(3), 2), respectively, have been successfully achieved. High diastereoselectivity was observed during the perfluoroalkylation of homochiral sulfinimines to give the corresponding perfluoroalkyl sulfinamides.
Collapse analysis of nanofibres (2007)

Continuous nanofibres fabricated by the electrospinning technique have found increasing applications (e.g. nanofibre composites, nanofibre devices, bioengineering tissue scaffolding, etc). For a nanofibre network subjected to a small external perturbation, the fibre segments within the network may deflect and stick to each other under the condition that their surface adhesion energy overcomes the elastic strain energy induced by fibre bending. Therefore, this paper aims to study adhesion-induced nanofibre collapse and relevant criteria. A simple fibre collapse model was proposed, which is based on the contact of two deflected elastic filaments under surface adhesion. Four fundamental fibre collapse modes (i.e. fibre-flat substrate, parallel fibres, orthogonal fibres and fibres at arbitrary angle) were considered, and corresponding collapse criteria were determined in explicit forms. Effects of fibre elasticity, surface adhesion and fibre geometries on the collapse criterion were explored in a numerical manner. Results show that for a fibre segment pair at a relatively large angle, the critical distance to induce the fibre collapse is independent of the fibre radius. This distance is a function of the fibre aspect ratio and the material intrinsic length (γ/E, where γ is the surface energy and E is Young's modulus). The fibre collapse model developed in this study can be used as the theoretical basis for design and failure analysis of nanofibre networks and nanofibre devices, among others.
New dynamic algorithms for shortest path tree computation (2000)

The open shortest path first (OSPF) and IS-IS routing protocols widely used in today's Internet compute a shortest path tree (SPT) from each router to other routers in a routing area. Many existing commercial routers recompute an SPT from scratch following changes in the link states of the network. Such recomputation of an entire SPT is inefficient and may consume a considerable amount of CPU time. Moreover, as there may coexist multiple SPTs in a network with a set of given link states, recomputation from scratch causes frequent unnecessary changes in the topology of an existing SPT and may lead to routing instability. We present new dynamic SPT algorithms that make use of the structure of the previously computed SPT. Besides efficiency, our algorithm design objective is to achieve routing stability by making minimum changes to the topology of an existing SPT (while maintaining shortest path property) when some link states in the network have changed. We establish an algorithmic framework that allows us to characterize a variety of dynamic SPT algorithms including dynamic versions of the well-known Dijkstra, Bellman-Ford, D'Esopo-Pape algorithms, and to establish proofs of correctness for these algorithms in a unified way. The theoretical asymptotic complexity of our new dynamic algorithms matches the best known results in the literature.
AN INVESTIGATION OF VARIOUS PROCEDURES FOR ANALYSIS OF MICROMAGNETIC BARKHAUSEN SIGNALS FOR NONDESTRUCTIVE EVALUATION OF STEELS (1992)

Abstract Current research undertaken at Iowa State University has been concerned with both the theoretical and experimental aspects of the Barkhausen effect. Here we discuss mainly the experimental techniques and including new Barkhausen effect instrumentation to detect and measure the emissions from ferromagnetic materials under the action of an alternating magnetic field H [21]. The capability of the system includes measurements of RMS Barkhausen voltage signals induced in a flux coil, pulse height analysis of these signals, frequency spectrum analysis, and Barkhausen pulse count rate analysis.
Effects of unknown shadowing and non-line-of-sight on indoor tracking using visible light (2017)

Indoor target tracking has garnered interest as communication systems and mobile device capabilities advance. Visible light communication (VLC) is an alternative to RF methods that uses light emitting diodes. In this paper, probabilistic filtering algorithms (particle and extended Kalman filters) are used for indoor tracking. The performance of the filters is compared with an another positioning method: trilateration. Probabilistic filtering methods are shown to be more reliable than trilateration for indoor tracking when non-line-of-sight components are significant. The probabilistic filtering algorithms require a light intensity map that is collected as a fingerprint map prior to tracking. The effect of unpredictable shadowing as the conditions change is examined in a scenario where one of the lamps has been shadowed. Our algorithm tracks the user equipment with less error than trilateration. The results also show that the tracking accuracy for our algorithms is on the order of the grid resolution of the fingerprint map for high signal-to-noise ratio environments.
Low threshold photopumped Al<i>x</i>Ga1−<i>x</i>As quantum-well heterostructure lasers (1983)

Data are presented on very low threshold photopumped separate-confinement quantum-well heterostructure (SC QWH) lasers grown by metalorganic chemical vapor deposition (MOCVD). An unusually thin single quantum well (size Lz≲ 60 Å) is employed in the QWH with the carriers confined (‘‘trapped’’) in the interior ‘‘cladding’’ region, which serves also as the optical waveguide. Excess carriers, which are photogenerated (or injected), are confined in the thin interior cladding region (size Lz′ ∼1000 Å) and, in this charge reservoir and waveguide region, are thermionically ‘‘emitted’’ back and forth across the well until scattered to lower energy in the well (ΔE∼ℏωLO) and collected. Continuous (cw) 300 K photopumed laser operation of these QWH’s is demonstrated for very short cavities. For one QWH wafer laser operation occurs at λ∼7730 Å with a photopumping threshold of 380 W/cm2 (Jeq ∼160 A/cm2) and for another wafer at λ∼7000 Å with threshold 103 W/cm2(Jeq∼ 410 A/cm2). The photopumped samples are as small as 20×40 μm, thus making these laser thresholds (for such short cavity lengths) a factor of 3–10 better than the lowest previously reported.
Synthesis and PKC Binding of a New Class of A-Ring Diversifiable Bryostatin Analogues Utilizing a Double Asymmetric Hydrogenation and Cross-Coupling Strategy (2006)

The design, asymmetric synthesis, and biological evaluation of a new class of bryostatin analogues based on a pseudosymmetric spacer domain are described. An aryl bromide diversification site is incorporated allowing access to systematically varied analogues. The new analogues all exhibit potent, nanomolar affinity to PKC.
Structure−Activity Relationships Study of Two Series of Leukotriene B<sub>4</sub>Antagonists:  Novel Indolyl and Naphthyl Compounds Substituted with a 2-[Methyl(2-phenethyl)amino]-2-oxoethyl Side Chain (1996)

N-Methyl-N-phenethylphenylacetamide has been reported to be a key binding domain to LTB4 receptors. Here we describe the synthesis and structure-activity relationship (SAR) studies of two new series of LTB4 receptor antagonists in which the phenyl ring of this receptor binding domain is replaced with indole and naphthalene, respectively. Results of these studies indicate that, in addition to the 2-[methyl(2-phenethyl)amino]-2-oxoethyl moiety, the presence of an acid group and a lipophilic side chain, as well as the spatial relationship of these three functions, is crucial for high binding affinity with LTB4 receptors. Our SAR studies also reveal that an arenecarboxylic acid, or an enoic acid in which the carboxyl group is conjugated with the central ring, is the preferred polar group. The lipophilic side chain of the naphthyl series was found to tolerate minor variations, ranging from a phenylmethoxy group to phenyl and alkyloxy groups. The most active compounds are 2-ethyl-3-[1-[2-[methyl(2-phenethyl) amino]-2-oxoethyl]-5-(phenylmethoxy)indol-3-yl]propenoic+ ++ acid (4g) of the indolyl series and 4-[2-[methyl(2-phenethyl)amino]-2-oxoethyl]-8-(phenylmethoxy )-2-naphthalenecarboxylic acid (2a) or the naphthyl series, with IC50 of 8 and 4.7 nM respectively, in the receptor binding assay using intact human neutrophils.
What's going on? (2008)

Existing traffic analysis tools focus on traffic volume. They identify the heavy-hitters - flows that exchange high volumes of data, yet fail to identify the structure implicit in network traffic - do certain flows happen before, after or along with each other repeatedly over time? Since most traffic is generated by applications (web browsing, email, p2p), network traffic tends to be governed by a set of underlying rules. Malicious traffic such as network-wide scans for vulnerable hosts (mySQLbot) also presents distinct patterns. We present eXpose, a technique to learn the underlying rules that govern communication over a network. From packet timing information, eXpose learns rules for network communication that may be spread across multiple hosts, protocols or applications. Our key contribution is a novel statistical rule mining technique to extract significant communication patterns in a packet trace without explicitly being told what to look for. Going beyond rules involving flow pairs, eXpose introduces templates to systematically abstract away parts of flows thereby capturing rules that are otherwise unidentifiable. Deployments within our lab and within a large enterprise show that eXpose discovers rules that help with network monitoring, diagnosis, and intrusion detection with few false positives.
High-Temperature Superconducting Oxide Synthesis and the Chemical Doping of the Cu-O Planes (1987)

Different synthesis techniques for the preparation of dense superconducting ceramics are discussed, and a sol-gel process is shown to be very promising. The effect of oxygen content, and the effect of substitution of Ni and Zn for copper, on the structural, transport and superconducting properties of the La-Sr-Cu-O and Y-Ba-Cu-O systems are presented. We find that substitution on the copper sites destroys Tc in the La-Sr-Cu-O system and decreases it in the Y-Ba-Cu-O system, and this effect is insensitive as to whether the 3d metal is magnetic (Ni) or diamagnetic (Zn). A detailed study of the YBa2Cu3O7-y system as a function of oxygen content (y) shows that superconductivity can be destroyed in these materials by the removal of oxygen and restored by reinjecting oxygen; either thermally at 500°C or at temperatures (80°C) compatible with device processing by means of a novel plasma oxidation process. Of scientific interest, the plasma process induces bulk superconductivity in the undoped La2CuO4.
Chemical vapor deposition of boron and boron nitride from decaborane(14) (1989)

We have investigated photoassisted, plasma enhanced chemical vapor deposition and pyrolytic deposition of boron from decaborane (B10H14) and boron nitride from decaborane combined with nitrogen or ammonia. The use of decaborane for depositing boron and boron nitride thin films is seen as a viable alternative to diborane or boron halides.
Towards the development of phased array systems for deep brain stimulation (2008)

Deep brain stimulation (DBS) is a clinical technique adopted for the treatment of various neurological disorders. One major limitation of todaypsilas DBS systems is the inability to focus the electric field in the desired direction and provide a more efficient stimulation. This study adopted 2D and 3D FEM tools to explore the the application of phased array (PA) techniques to control the direction of the stimulation pattern delivered during DBS. Results illustrate that a PA DBS system can be used to steer the stimulation pattern from broadside to endfire, by driving the electrode contacts with high frequency sinusoids with phase delays varying from 0deg to 90deg. This study can provide a framework for future investigation in the development of more efficient DBS systems based on PA technology.
Enhancement of Microwave Drying Under Reduced Pressure Condition by Irradiation Control and External Air Supply (2006)

We present a novel microwave drying as an effective drying method for seafood. Microwave is irradiated in pulse or intermittently so as to keep the temperature of material at around room temperature in a reduced pressure system. Energy of microwave is supplied just for the latent heat for evaporation. Also, by introducing a small amount of external air into the system, water vapor can be effectively carried out of the drying system. We made several experiments using the scallop as seafood. The drying time was successfully shortened as compared with the warm-air drying and the drying at room-temperature results in good quality for dried seafood. Microphotographs of scallop indicate us that the morphological change of the muscular fiber-cells has an important role in water transport. The present drying method prevent from the cell shrink at the scallop surface observed in the warm-air drying, but keep the channel for water transportation to the outside. The new method is proved to be an effective and applicable way of seafood drying.
Synthesis and biological activities of 2-pyrimidinone nucleosides. 2. 5-Halo-2-pyrimidinone 2'-deoxyribosides (1985)

1-(2-Deoxy-beta-D-ribofuranosyl)-5-bromo-2-pyrimidinone (BrPdR) and 1-(2-deoxy-beta-D-ribofuranosyl)-5-iodo-2-pyrimidinone (IPdR) have been synthesized by condensation of the appropriate silylated bases 2a and 2b, respectively, with 3,5-bis-O-(p-chlorobenzoyl)-2-deoxy-alpha-D-ribofuranosyl chloride (8) in 1,2-dichloroethane, in the presence of SnCl4, followed by separation of the anomeric blocked nucleosides via column chromatography and subsequent deprotection with methanolic ammonia. Both BrPdR and IPdR exhibited significant antiherpes activities against various strains of HSV-1 and HSV-2, the latter compound (IPdR) showing the higher activity as well as the stronger binding to the virus-specific thymidine kinase.
Limits to anatomical accuracy of diffusion tractography using modern approaches (2018)

Abstract Diffusion MRI fiber tractography is widely used to probe the structural connectivity of thebrain, with a range of applications in both clinical and basic neuroscience. Despite widespread use, tractography has well-known pitfalls that limits the anatomical accuracy of this technique. Numerous modern methods have been developed to address these shortcomings through advances in acquisition, modeling, and computation. To test whether these advances improve tractography accuracy, we organized the ISBI 2018 3D Validation of Tractography with Experimental MRI (3D-VoTEM) challenge. We made available three unique independent tractography validation datasets – a physical phantom and two ex vivo brain specimens - resulting in 176 distinct submissions from 9 research groups. By comparing results over a wide range of fiber complexities and algorithmic strategies, this challenge provides a more comprehensive assessment of tractography’s inherent limitations than has been reported previously. The central results were consistent across all sub-challenges in that, despite advances in tractography methods, the anatomical accuracy of tractography has not dramatically improved in recent years. Taken together, our results independently confirm findings from decades of tractography validation studies, demonstrate inherent limitations in reconstructing white matter pathways using diffusion MRI data alone, and highlight the need for alternative or combinatorial strategies to accurately map the fiber pathways of the brain.
A double motion-compensated orthogonal transform with energy concentration constraint (2007)

This paper discusses a transform for successive pictures of an image sequence which strictly maintains orthogonality while permitting 2-hypothesis motion compensation between pairs of pictures. We extend previous work on an orthogonal transform for image sequences which uses only 1-hypothesis motion compensation between pairs of pictures. This work is motivated by the well known fact that the motion-compensated lifted Haar wavelet maintains orthogonality only approximately. In the case of zero motion fields, the motion-compensated lifted Haar wavelet is known to be orthogonal. But for complex motion fields with many multi-connected and unconnected pixels, the motion-compensated lifted Haar wavelet cannot accurately maintain its transform property and, hence, suffers a performance degradation. The presented double motion-compensated orthogonal transform strictly maintains orthogonality for any motion field. For the transform, each pixel in the high-band is compensated by a linear combination of two motion-compensated pixels chosen from the corresponding low-band. That is, each pixel in the high-band is associated with two motion vectors. This is in contrast to the previously presented single motion-compensated orthogonal transform where each pixel in the high-band is compensated by only one motion-compensated pixel chosen from the corresponding low-band. In terms of energy concentration, the double motion-compensated orthogonal transform outperforms the single motion-compensated orthogonal transform and compares favorably with the double motion-compensated lifted Haar wavelet.
A Spatial-Temporal Multiresolution CMOS Image Sensor With Adaptive Frame Rates for Tracking the Moving Objects in Region-of-Interest and Suppressing Motion Blur (2007)

In this paper, we report a CMOS image sensor for spatial-temporal multiresolution images. This image sensor simultaneously generates two outputs: one for normal images (<30 fps) of stationery background and the other for adaptable frame-rate images (over 960 fps) of moving objects. The moving objects are tracked with a reduced spatial resolution in the region-of-interest (ROI). The entire image is reconstructed from the two images with the details in stationery objects and the suppressed motion blur in moving objects. High frame rate only applies to the ROI; therefore, the proposed scheme can significantly reduce power consumption by adjusting the optimal use of bandwidth. In order to provide real-time decision of ROI, the sensor employs on-chip motion-detection circuits based on the inter-pixel switch operation by storing the previous frame signal in a floating diffusion node. This allows a small pixel implementation without adding any extra in-pixel memory components. A prototype chip has been implemented using a 0.35 mum 1P4M standard CMOS process and multiresolution images have been successfully captured. The fabricated chip operates at 3.3 V and consumes 75 mW in the multiresolution readout of a 256times256 normal image at 30 fps and a 64times64 ROI image at 240 fps.
On Finding of Personal Characteristics of Signatures Using Genetic Algorithm with a Local Improvement Mechanism (1996)

This paper presents a new method to find personal characteristics of signatures using a genetic algorithm. The new method uses a new coding method, a new crossover method, and a genetic algorithm with a local improvement mechanism. The new coding method is devised for finding personal characteristics from signatures. The new crossover method determines the number of characteristics used for the signature verification. The genetic algorithm is very efficient in improving the local portions of chromosomes.Experiments are done to show that the personal characteristics are efficiently found by the proposed method.
<title>Dynamic heater for display elements</title> (1997)

Liquid crystal display (LCD) deliver optimal performance when the entire display surface is isothermal and at a controllable temperature. This condition creates uniform electro-optical properties within the liquid crystal layer. This paper describes a dynamic, multicontact heater system that actively compensates for uneven heat loads, thereby creating the desired isothermal condition. The heater system includes a uniform resistive sheet, with multiple electrical contacts around the perimeter. A switch network connects each heater contact to a power supply, ground potential, or a high impedance. A microprocessor monitors the display temperature, and detects non-uniformity, and selectively applies heat to cold areas of the display. The dynamic heater system employs a variety of heating patterns to create the desired isothermal condition.Heating patterns vary in duration, power applied, and location on the display face. The microprocessor control loop can also detect and isolate faulty drive elements, and compensate for non- uniformity in the heater itself. The heater prevents stress- induced delaminations, mechanical distortions, and stress- induced birefringence in optical components. Test results indicate that a dynamic heater can be beneficial in the thermal design of LCD products.
Temperature desensitisation of delay in optical fibres for sensor applications (1983)

We demonstrate a significant reduction in delay sensitivity against temperature in optical fibres, using a novel tight jacketed fibre structure. This technique has the cabability of producing fibre in which the optical delay is insensitive to temperature. This has potential in the field of sensors and fibre devices.
Tissue characterization based on scatterer number density estimation (1988)

The authors propose a robust model for characterizing the statistical nature of signals obtained from ultrasonic backscatter processes. The model can accommodate frequency-dependent attenuation, spatially varying media statistics, arbitrary beam geometries, and arbitrary pulse shapes. On the basis of this model, statistical schemes are proposed for estimating the scatterer number density (SND) of tissues. The algorithm for estimating the scatterer number incorporates measurements of both the statistical moments of the backscattered signals and the point spread function of the acoustic system. The number density algorithm has been applied to waveforms obtained from ultrasonic phantoms with known number densities and in vitro mammalian tissues. There is an excellent agreement among theoretical, histological, and experimental results. The application of this technique for noninvasive clinical tissue characterization is discussed.