gebhart/patrepeval huggingface dataset:
Yaw rate and linear velocity stabilized manual wheelchair (2013)

We present the development of a prototype novel low-power, inexpensive stability control system for manual wheelchairs. Manual wheelchairs, while providing the ability to maneuver in relatively small indoor spaces, have a high center of gravity making them prone to tipping. Additionally, they can easily slide on sloped surfaces and can even spin and tip when attempting to turn or brake too quickly. When used on ramps and in outdoor environments where the surface is rarely perfectly flat (slopes greater than 1∶20 (5%) are common), wheelchair users can easily encounter potentially dangerous situations. The design and evaluation of an accident prevention system for independent manual wheelchair users that increases independence by enabling mobility with greater confidence and safety is described. The system does not limit a wheelchair user's ability to manually brake, rather, if the system detects that the wheelchair is out of control, braking force will be added by the system to either one or both wheels. The prototype utilized inexpensive bicycle technologies for the wheel brake and electrical power generator assemblies. Custom servos were designed along with custom electronics and firmware in the prototype to evaluate performance. The goal of the project was to derive specifications for a control and actuation system that utilizes inexpensive bicycle components in this cost-sensitive application. The design is detailed and the final specifications provided.
Simple data link (SDL) protocol: an efficient and low complexity data link protocol for high-speed packet networks (2003)

The simple data link (SDL) is a framing protocol for asynchronous, variable/fixed, length packets over a general-purpose point-to-point communications channel. The SDL relies on an ATM HEC-like framing mechanism that requires no special encoding of the framed protocol data unit (PDU) such as in HDLC framing. Its low implementation complexity makes SDL particularly suitable for high-speed transmission links such as SONET/SDH point-to-point links and SONET/SDH paths, wavelength links in an optical network, and others. For a high data rate environment, SDL is a very attractive alternative to more conventional solutions such as ATM, frame relay or PPP-over-SONET (POS).
Fabrication and characterization of nanostructured titania films with integrated function from inorganic–organic hybrid materials (2012)

Nanostructured titania films are of growing interest due to their application in future photovoltaic technologies. Therefore, a lot of effort has been put into the controlled fabrication and tailoring of titania nanostructures. The controlled sol-gel synthesis of titania, in particular in combination with block copolymer templates, is very promising because of its high control on the nanostructure, easy application and cheap processing possibilities. This tutorial review gives a short overview of the structural control of titania films gained by using templated sol-gel chemistry and shows how this approach is extended by the addition of further functionality to the films. Different expansions of the sol-gel templating are possible by the fabrication of gradient samples, by the addition of a homopolymer, by the combination with micro-fluidics and also by the application of novel precursors for low-temperature processing. Moreover, hierarchically structured titania films can be fabricated via the subsequent application of several sol-gel steps or via the inclusion of colloidal templates in a one-step process. Integrated function in the block copolymer used in the sol-gel synthesis allows for the fabrication of an integrated blocking layer or an integrated hole-conductor. Both approaches grant a one-step fabrication of two components of a working solar cell, which make them very promising towards a cheap solar cell production route. Looking to the complete solar cell, the top contact is also of great importance as it influences the function of the whole solar cell. Thus, the mechanisms acting in the top contact formation are also reviewed. For all these aspects, characterization techniques that allow for a structural investigation of nanostructures inside the active layers are important. Therefore, the characterization techniques that are used in real space as well as in reciprocal space are explained shortly as well.
22.4 A 24Gb/s 0.71pJ/b Si-photonic source-synchronous receiver with adaptive equalization and microring wavelength stabilization (2015)

Wavelength-division multiplexing (WDM) optical interconnect architectures based on microring resonator devices offer a low-area and energy-efficient approach to realize both high-speed modulation and WDM with high-speed transmit-side ring modulators and high-Q receive-side drop filters [1-3]. While CMOS optical front-ends have been previously developed that support data-rates in excess of 20Gb/s, these designs often do not offer the retiming and deserialization functions required to form a complete link [1,4]. Furthermore, along with the requirements of a sensitive energy-efficient receiver front-end with low-complexity clocking, wavelength stabilization control is necessary to compensate for the fabrication tolerances and thermal sensitivity of microring drop filters. In this work, a 24Gb/s hybrid-integrated microring receiver is demonstrated the incorporates the following key advances: 1) a low-complexity optically-clocked source-synchronous receiver with LC injection-locked oscillator (ILO) jitter filtering; 2) a large input-stage feedback resistor TIA cascaded with an adaptively-tuned continuous-time linear equalizer (CTLE) for improved sensitivity and bandwidth; 3) a receive-side thermal tuning loop that stabilizes the microring drop filter resonance wavelength with minimal impact on receiver sensitivity.
Solar energy harvesting in photoelectrochemical solar cells (2007)

Here we study different approaches for increasing energy harvesting in titania based photoelectrochemical solar (PES) cells. We study the light harvesting of PES cells when photonic crystal and photonic sponge architectures are used. We also report on the influence of the surface corrugation of the metal electrode on the harvesting of photocarriers in solar cells
An electrically pumped hybrid silicon evanescent amplifier (2007)

A hybrid silicon evanescent amplifier utilizing a wafer bonded structure of a silicon waveguide and AlGalnAs quantum wells is demonstrated. Maximum chip gain obtained is 13 dB with a 3 dB output saturation power of 11 dBm.
Empirical formulation for debris flow impact and energy release (2022)

Abstract Full understanding the interaction mechanisms between flow-like landslides and the impacted protection structures is an open issue. While several approaches, from experimental to numerical, have been used so far, it is clear that the adequate assessment of the hydromechanical behaviour of the landslide body requires both a multiphase and large deformation approach. This paper refers to a specific type of protection structure, namely a rigid barrier, fixed to the base ground. Firstly, a framework for the Landslide-Structure-Interaction (LSI) is outlined with special reference to the potential barrier overtopping (nil, moderate, large) depending on the features of both the flow and the barrier. Then, a novel empirical method is casted to estimate the impact force on the barrier and the time evolution of the flow kinetic energy. The new method is calibrated by using an advanced hydro-mechanical numerical model based on the Material Point Method. The validation of the empirical formulation is pursued referring to a large dataset of field evidence for the peak impact pressure. Both numerical and empirical methods can appropriately simulate the physical phenomena. The performance of the newly proposed empirical method is compared to the literature methods and its advantages are outlined.
Common field-of-view of cameras in robotic swarms (2013)

Cooperative swarms of robots with cameras can provide stereo and multi-view vision. They are robust against failures and introduce diversity in the case of poor conditions. Cameras are used both for data acquisition and navigation. Additional sensors also play a role in the SLAM tasks (Simultaneously Localization and Mapping). The independent mobility of the robots/cameras leads to a situation in which the common field-of-view (FOV) of cameras changes continuously. The present paper addresses the task of acquiring and tracking the cameras FOVs. State-of-the-art FOV characterization techniques count feature points or do image segmentation. These methods are often not accurate or complex. We propose an adaptive common FOV detection method based on fuzzy plane clustering. The performance of the method is shown to be invariant under baseline scaling. An autonomous grouping algorithm is further proposed with respect to both distance of robots and overlapping FOV of cameras.
A Melanoma Cell State Distinction Influences Sensitivity to MAPK Pathway Inhibitors (2014)

Although most BRAF(V600)-mutant melanomas are sensitive to RAF and/or MEK inhibitors, a subset fails to respond to such treatment. This study characterizes a transcriptional cell state distinction linked to MITF and NF-κB that may modulate intrinsic sensitivity of melanomas to MAPK pathway inhibitors.
A comparison of sorting algorithms for the connection machine CM-2 (1991)

We have implemented three parallel sorting algorithms on the Connection Machine Supercomputer model CM-2: B atcher's bitonic sort, a parallel radix sor~and a sample sort similar to Reif and Valiant's flashsort. We have also evaluated the implementation of many other sorting algorithms proposed in the literature.
Active Sticks: a New Dimension in Controller Design (1984)

A smart stick controller was built which actively produces a force to interact with the subject's hand and to aid in tracking. When the human tracks in this situation, the man-machine system can be viewed as the combination of two closed loop feedback paths. The inner loop occurs as a result of a tactile information channel effecting the man-controller interaction through force with this stick in the active mode (the stick generates a force) and the passive mode (the stick not generating a force) are reported. The most noteworthy observation is a significant increase in apparent neuromotor bandwidth and consequently better tracking performance.
Full-Scale Testing of PM Linear Generator for Point Absorber WEC (2005)

This thesis deals with a system for operation of directly driven offshore wave energy converters. The work that has been carried out includes laboratory testing of a permanent magnet linear generator, wave energy converter mechanical design and offshore testing, and finally design, implementation, and offshore testing of an underwater collector substation. Long-term testing of a single point absorber, which was installed in March 2006, has been performed in real ocean waves in linear and in non-linear damping mode. The two different damping modes were realized by, first, a resistive load, and second, a rectifier with voltage smoothing capacitors and a resistive load in the DC-link. The loads are placed on land about 2 km east of the Lysekil wave energy research site, where the offshore experiments have been conducted. In the spring of 2009, another two wave energy converter prototypes were installed. Records of array operation were taken with two and three devices in the array. With two units, non-linear damping was used, and with three units, linear damping was employed. The point absorbers in the array are connected to the underwater substation, which is based on a 3 m3 pressure vessel standing on the seabed. In the substation, rectification of the frequency and amplitude modulated voltages from the linear generators is made. The DC voltage is smoothened by capacitors and inverted to 50 Hz electrical frequency, transformed and finally transmitted to the on-shore measuring station. Results show that the absorption is heavily dependent on the damping. It has also been shown that by increasing the damping, the standard deviation of electrical power can be reduced. The standard deviation of electrical power is reduced by array operation compared to single unit operation. Ongoing and future work include the construction and installation of a second underwater substation, which will connect the first substation and seven new WECs.
Graph-based verification and misbehavior detection in multi-agent networks (2014)

Multi-agent networks consist of autonomous nodes, where each node maintains and updates its state based on exchanged information with its neighboring nodes. Due to the collaborative nature of state updates, if one or more nodes were to misbehave by deviating from the pre-specified update rule, they can bias the states of other nodes and thus drive the network to an undesirable state. In this paper, we present a query-based mechanism for a third-party verifier to detect misbehaving nodes. The proposed mechanism consists of two components. The first component determines whether the state of the queried node is consistent with its ideal value. The second component identifies the set of misbehaving nodes that induced the inconsistency. We prove that our approach detects the set of misbehaving nodes, as well as the times of their misbehaviors, by establishing the equivalence of our approach to a tree-generation algorithm. We evaluate our approach through simulation study which corroborates the theoretical guarantees, and analyzes the performance of our scheme as a function of the number of queried nodes.
Two-cross-polarized-frequency VECSEL at 852nm for CPT-based Cs clocks (poster) (2013)

International audience
Two kinases mediate agonist-dependent phosphorylation and desensitization of the beta 2-adrenergic receptor. (1990)

Binding of the catecholamine agonists epinephrine and norepinephrine to the beta-adrenergic receptor (BAR) rapidly activates adenylate cyclase via the stimulatory guanine nucleotide regulatory protein Gs, and results in rises in cellular levels of cAMP. However, continuous exposure to these agonists leads within minutes to a dampening of the enzymatic response. Both in vivo and in vitro studies have implicated agonist-induced phosphorylation of BAR in this process. These results include the isolation of a novel beta-adrenergic receptor kinase (BARK), which has been shown to preferentially phosphorylate receptors that are occupied by agonist when assessed in vitro. Recent studies in our laboratory have examined the desensitization process in intact cells to determine where on the receptor molecule functionally relevant phosphorylation occurs, and to identify the kinase(s) involved. In one set of studies, site-specific mutagenic techniques with the cloned gene for the human beta 2-adrenergic receptor were utilized to delete putative sites of phosphorylation by BARK and/or the cAMP-dependent protein kinase (PKA). Following expression of the mutated receptors in mammalian cells, the cells were challenged with different concentrations of agonist for 10-15 min and the functional and phosphorylation properties of the mutant receptors were then assessed. In another set of studies human A431 cells were permeabilized with low concentrations of digitonin and treated with selective inhibitors of both BARK and PKA. The cells were then exposed to desensitizing concentrations of agonist, and similar measurements performed. Taken together, the results from both sets of studies suggest that exposure of cells to low (nanomolar) concentrations of agonist leads to phosphorylation of the receptor on one or both consensus sites for PKA, and that the predominant effect of this phosphorylation on the adenylyl cyclase response is a loss in sensitivity of the receptor to further stimulation by the agonist. In contrast, exposure of cells to higher (micromolar) concentrations of agonist leads to BAR phosphorylation by both PKA and BARK, the latter on the carboxyl terminal region of the receptor. Phosphorylation of the receptor by both kinases appears to be required for the full desensitization effect seen with the high concentration of agonist, which includes both losses in sensitivity and in the maximal responsiveness of the adenylyl cyclase response upon subsequent challenge with the agonist. Such a dual kinase control of BAR phosphorylation may have important implications for understanding the regulation of desensitization under different physiological circumstances.
Evaluation of AddUp Precision L-PBF Technology for Tooling and Other Industrial Applications (2022)

ORNL (Contractor) and AddUp Inc. (Participant) collaborated to enable the adoption of laser powder bed fusion for tooling applications, critical for reshoring the manufacturing sector in the U.S. Most of the work on laser powder bed fusion has focused on high value materials such as Ti-6Al-4V and Inconel 718 for niche applications in aerospace, biomedical and energy sectors. In this collaboration, ORNL and AddUp worked laser powder bed fusion of maraging steels for tooling applications while leveraging the unique ability of the AddUp laser powder bed fusion system to deposit fine powders. We demonstrated that the AddUp technology is capable of depositing complex artifacts and features such as overhangs within desired tolerances. We also showed that direct aging of the deposited parts result in simultaneously higher strength and elongation compared to the conventional two step heat treatments, which could result in significant energy savings. Finally, we developed thermos-kinetic models to enable design of heat treatments for optimal material properties compared to the energy intensive empirical methods currently used. The report summarizes the detailed findings of this collaboration.
Time-gated Cherenkov emission spectroscopy from linear accelerator irradiation of tissue phantoms (2012)

Radiation from a linear accelerator induces Cherenkov emission in tissue, which has recently been shown to produce biochemical spectral signatures that can be interpreted to estimate tissue hemoglobin and oxygen saturation or molecular fluorescence from reporters. The Cherenkov optical light levels are in the range of 10(-6) to 10(-9) W/cm2, which limits the practical utility of the signal in routine radiation therapy monitoring. However, due to the fact that the radiation is pulsed, gated-acquisition of the signal allows detection in the presence of ambient lighting, as is demonstrated here. This observation has the potential to significantly increase the value of Cherenkov emission spectroscopy during radiation therapy to monitor tissue molecular events.
Stability control and analysis of two-wheeled vehicles out of plane dynamics (2018)

Questo lavoro presenta lo studio e la progettazione di un sistema di controllo per la stabilita delle dinamiche fuori dal piano di veicoli a due ruote. La tesi e divisa in tre parti: la prima parte e dedicata ad introdurre le dinamiche di un veicolo a due ruote e alla descrizione dei sensori ed attuatori comunemente usati su motoveicoli in produzione; la seconda parte e focalizzata sull’implementazione di un modello multi-body, la progettazione dell’algoritmo di controllo per la stabilita e la progettazione dell’ammortizzatore ottimo rispetto alla maneggevolezza del veicolo; la terza parte presenta la stima dell’angolo di side-slip di un veicolo a due ruote. Il controllo gestisce due aspetti fondamentali: stabilita dei modi fuori dal piano per mezzo di un ammortizzatore semi-attivo di sterzo e l’ammortizzamento ottimo dello stesso quando il veicolo non e soggetto a instabilita. L’ultima parte del lavoro e dedicata alla stima dell’angolo di side-slip per mezzo di due metodi: data-driven con l’uso di Reti Neurali e model-based. Entrambi i problemi, di controllo e di stima sono inizialmente analizzati in simulazione e testati sperimentalmente con un motoveicolo.
Lithographically-defined 3D porous networks as active substrates for surface enhanced Raman scattering (2011)

Interferometric lithographically fabricated porous carbon acts as active substrates for Surface Enhanced Raman Scattering (SERS) applications with enhancement factors ranging from 7 to 9 orders of magnitude.
PCM-based uncertainty reduction in support of model validation for depletion calculations (2022)

This manuscript further develops a recent methodology, denoted by Physics-guided Coverage Mapping (PCM), to support model validation for neutronic depletion calculations. The overarching goal of model validation is to develop confidence in model predictions for the application of interest via fusion of both simulation results and measurements from scaled-down experiments, and whenever possible to improve predictions by explaining the observed discrepancies. This manuscript focuses on the isotopic depletion problem, that is how to improve the predictions of depleted fuel isotopic across the range of expected burnup based on a limited number of post-irradiation measurements. PCM employs an information theoretic approach, capable of directly transferring, i.e., without performing model inversion, biases and their uncertainties from the available measurements to the quantities of interest (QoIs), representing the isotopic concentrations at different burnup values and/or different irradiation spectra. It precludes the need for sensitivity coefficients and only requires forward model executions, and can be applied using non-informative priors, often required by Bayesian-based methods. This is achieved via a mapping kernel relating a number of predictor variables, the concentrations of single or multiple isotopes at certain burnup, to the QoIs, the isotopic concentrations at target burnup such as end of life. Proof-of-principle calculations are demonstrated using both representative PWR and BWR lattice models, where the goal is to employ measurements at given burnup value(s) from one lattice to predict the isotopic concentrations across burnup for the same or the other lattice. Results show 50% to 90% reduction in uncertainties of isotopic concentrations across burnup as compared to the prior uncertainty.
SiGe HBTs in 90nm BiCMOS Technology Demonstrating fT/fMAX 285GHz/475GHz through Simultaneous Reduction of Base Resistance and Extrinsic Collector Capacitance (2014)

Development of SiGe HBTs in BiCMOS technology with both high f T and f MAX faces significant challenges. To increase f T , thinning the base and collector thickness is generally the first step to reduce the carrier transit times, but this increases the base resistance and the collector-base capacitance, which impacts f MAX negatively. Increasing collector doping is also often employed to increase f T , but this increases collector-base capacitance, which drives f MAX down. To overcome these limits, millisecond anneal techniques, low temperature silicide and low temperature contact processes are employed to reduce the base resistance. Concurrently a novel approach to reduce the extrinsic collector-base capacitance is developed, without affecting the manufacturability and integration with CMOS. The simultaneous reduction of both base resistance and collector capacitance enables high performance SiGe HBT devices in 90nm BiCMOS Technology with operating frequencies of 285/475GHz f T / f MAX .
First-in-man assessment of plaque rupture by polarization-sensitive optical frequency domain imagingin vivo (2016)

A 50-year-old man underwent primary percutaneous coronary intervention for anterior ST-segment elevation myocardial infarction 3 h after symptom onset. After thrombectomy, polarization-sensitive optical frequency domain imaging (PS-OFDI) was performed at the culprit left anterior descending artery lesion using a prototype imaging system (Wellman Center for Photomedicine). In addition to the conventional image of plaque structure, PS-OFDI provides a measure of tissue birefringence. This optical tissue property is elevated in tissue with regularly organized architecture, …