gebhart/patrepeval huggingface dataset:
Plasmonic Antireflection Coating for Photoconductive Terahertz Generation (2017)

Plasmon-enhanced photoconductive antennas allow for improved performance, particularly in below-band-gap absorption devices using low-temperature-grown GaAs. Here we design the plasmonic nanostructures to act as antireflection coatings as well, achieving below 10% reflection at 1570 nm wavelength in an optimized device. Quantitative agreement is seen between experiment and theory. Terahertz emission field amplitudes demonstrate 18 times enhancement compared to that of a conventional terahertz photoconductive antenna on the same substrate.
Number-Theoretic Sequence Design for Uncoordinated Autonomous Multiple Access in Relay-Assisted Machine-Type Communications (2017)

Terminal relaying is expected to offer an effective means for realizing machine-type communications (MTC) in wireless cellular networks. In the absence of channel quality indicators, the effective utilization of relaying terminals (RTs) requires a mechanism by which RTs can autonomously assign available resource blocks (RBs) to potentially large numbers of uncoordinated MTC devices with minimal conflicts. Unlike random RB assignments, which do not offer performance guarantees, using prescribed RB assignment sequences provides an opportunity for obtaining performance gains. However, realizing these gains requires optimizing RB assignments over a large set of lengthy sequences. One technique for selecting assignment sequences is based on an exhaustive search of exponential complexity over sequences generated by multiplicative cyclic groups. This technique restricts the number of RBs to be prime minus one and does not consider sequences generated using other group operations. In this paper, we use group isomorphism to eliminate the constraint on the number of RBs and to show that the optimal assignment sequences generated by a specific cyclic group are globally optimal over the set of all cyclically generated sequences. We develop a greedy algorithm with polynomial complexity for the sequential selection of RB assignment sequences in systems with large numbers of RTs and arbitrary device distributions. This algorithm is further simplified by invoking the graphical representation of cyclic groups. The resulting algorithm is more efficient and thus suitable for generating assignment sequences for relay-assisted massive multiple access Internet-of-Things systems. Numerical results show that the performance of the sequences generated by the greedy algorithms is comparable to that of those generated by exhaustive search, but with much less computational cost.
Quasiatomic layer etching of silicon oxide selective to silicon nitride in topographic structures using fluorocarbon plasmas (2017)

The precision etch of dielectric materials (SiO2, Si3N4) in self-aligned contacts and self-aligned multiple patterning at the 10 nm technology node and beyond is required to solve/mitigate the trade-offs of selectivity, profile, and aspect ratio independent etching. Atomic layer etching (ALE) has significant potential to solve the trade-offs challenge. Unlike the halogenation step of atomic layer etching of silicon using chlorine (e.g., chlorine adsorption on c-Si), the fluorocarbon deposition step of ALE of nitride and oxide is not a self-limiting process. The argon ion bombardment step used to remove CF polymer layer and activated layer of oxide and nitride can be self-limiting if ion energy is kept below the sputter threshold. In this paper, the authors will discuss concurrent engineering approaches including both modeling and experimentation that can provide visibility to the parameters characterizing a viable process. The core of the approach is a new integrated chamber hybrid plasma equipment model-feature scale Monte Carlo feature profile model for silicon dioxide etch experiments intended to be selective to organic planarization layer masked silicon nitride structures. The experiments were conducted on a dual frequency capacitively coupled plasma source using a benchmark Ar/C4F6 chemistry for adsorption and an argon plasma step for desorption in the cyclic etch process. The concurrent engineering approach comprises stages of simulation development and prediction tests using both blanket wafer and patterned wafer data, and finally, process parameter optimization. Plasma parameters for each of the fluorocarbon layer adsorption and desorption etch steps are presented. The authors show how nitride/oxide etch selectivity can be optimized using saturation, “S”-curves, and detail pattern top clogging and its correlation with mask topography. S-curves describe etch/deposition rate trends as a function of desorption time in cyclic etch processes. The results show that clogging margin is a sensitive function of desorption time and feature topography.
A 0.5MHz mode-matched pitch or roll annulus gyroscope with nano-gap slanted electrodes for quadrature cancellation (2017)

This paper presents, for the first time, the effective quadrature cancellation in a high-frequency pitch or roll bulk acoustic wave (BAW) gyroscope to enable perfect mode-matching for sensitivity improvement and noise reduction. The presented gyroscope has a high operation frequency of 0.5MHz and high translational stiffness for shock and vibration robustness. Quadrature cancellation, which is the biggest challenge in high-performance pitch or roll gyroscopes, is achieved by incorporating nano-gap slanted electrodes through the new HARPSS+ fabrication process, which combines anisotropic wet-etching of silicon with conventional DRIE-based HARPSS process. The HARPSS+ process enables precision capacitive transduction and tuning in all desired orientations, providing tuning coverage over typical process corners and significantly improving the yield of pitch or roll gyroscopes. Quadrature cancellation is verified on fabricated devices, allowing a perfectly mode-matched operation with a scale factor of 95.2pA/(°/s) and an open-loop bandwidth of 15Hz. The HARPSS+ process also enables simultaneous fabrication of single-chip tri-axial BAW gyroscopes: high-frequency (0.5-5MHz) gyroscopic modes with high quality factors (10,000s- 100,000s) are measured on both yaw and pitch/roll BAW gyroscopes on the same wafer.
Influence of amorphicity on properties of Ce-Ti mixed oxide films for electrochromic devices (2007)

Alcohol based sols of cerium chloride and titanium propoxide mixed in 1:1 and 1:3 mole ratios have yielded mixed oxide films with excellent chemical as well as mechanical stability on densification at 500°C. The 1:1 films are more transparent due to their highly porous structure. Electrochemical studies have revealed the significant role of TiO 2 in controlling the ion storage capacity of the films, as it induces amorphicity in them. Although both the films are found to be amorphous to X-rays, the 1:1 composition however, is characterized by the presence of CeO 2 nanocrystallites of about 5 nm dimension. XPS studies have shown the presence of both Ce 3+ and Ce 4+ states in the films. Scanning electron microscopic study has shown the presence of CeO 2 and TiO 2 agglomerates respectively in the 1:1 and 1:3 films. The faster coloration-bleaching kinetics for the primary electrochromic electrode working in combination with Ce/Ti (1:1) electrode indicates the better utility of the latter in electrochromic windows. Appreciable optical modulation of the electrochromic devices comprising both the Ce/Ti compositions of the counter electrodes over the visible spectral region displays their potential as the ion storage layer for the electrochromic windows.
Inexact Adjoint-based SQP Algorithm for Real-Time Stochastic Nonlinear MPC (2020)

This paper presents a real-time algorithm for stochastic nonlinear model predictive control (NMPC). The optimal control problem (OCP) involves a linearization based covariance matrix propagation to formulate the probabilistic chance constraints. Our proposed solution approach uses a tailored Jacobian approximation in combination with an adjoint-based sequential quadratic programming (SQP) method. The resulting algorithm allows the numerical elimination of the covariance matrices from the SQP subproblem, while ensuring Newton-type local convergence properties and preserving the block-sparse problem structure. It allows a considerable reduction of the computational complexity and preserves the positive definiteness of the covariance matrices at each iteration, unlike an exact Jacobian-based implementation. The realtime feasibility and closed-loop control performance of the proposed algorithm are illustrated on a case study of an autonomous driving application subject to external disturbances.
Use of ERCC1 gene expression to predict the effectiveness of platin-based therapy in colorectal, ovarian and lung cancer (2008)

2541 Background: ERCC1 expression is associated with tumor response, progression free survival and overall survival of cancer patients treated with platin-based therapies. We have determined the optimal cut-point values of ERCC1 gene expression for separating patients with best and worst outcomes from platin-based chemotherapy in 3 different types of cancer. Methods: Formalin-fixed paraffin-embedded (FFPE) tumor tissue samples were obtained from 366 patients with NSCLC treated in a multicenter phase III trial. The regimes were docetaxel plus cisplatin or docetaxel plus gemcitabine. An additional 191 FFPE from patients with metastatic colorectal cancer treated with FOLFOX ± PTK/ZK in first- and second-line treatment enrolled in the CONFIRM 1 and CONFIRM 2 studies were analyzed. Further, we examined 145 ovarian cancer patients treated with carboplatin or cisplatin alone or in combination with docetaxel or paclitaxel. FFPE tissues were microdissected and analyzed for ERCC-1 mRNA expression using quantitative real-time RT-PCR. The maximal chi-square method was used to determine optimal cut-point values of ERCC1 gene expressions that best segregated patients into poor- and good-outcome subgroups. Results: In lung cancer, ERCC1 showed a relative range from 0.19 to 8.67 (median 1.56). The cut-point value dividing low- and high- expression was 1.71 (53rd percentile). The low-expression group had a 10% greater objective response rate. In colon cancer the range was 0.34 to 4.66 (median 1.16). The cut-point value that best divided patients into long- and short-term survivors was 1.71 (80th percentile, confirming our earlier results in JCO 2001: 4298–4304). In ovarian cancer, the range of expression was 0.38 to 15.71 (median 2.68) with a cut-point at 4.8 (80th percentile) significantly separating patients for overall and progression-free survival. Conclusions: ERCC1 gene expression is a useful predictor of the effectiveness of platin therapy in a number of cancers with precisely determinable ranges and effectiveness cut-point values. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Novartis, Response Genetics Inc. Novartis, Response Genetics Inc., sanofi-aventis Novartis, Response Genetics Inc. Novartis, sanofi-aventis Novartis
A spatial sampler using integrated optic techniques (1986)

A spatial sampler for detecting transient RF and microwave signals is proposed. The sampler consists of a series of electrooptic directional couplers spatially located along an integrated-optic waveguide beneath a coplanar RF stripline. It is theoretically shown that the sampler has the potential of sampling with a temporal resolution of a few picoseconds and a sampling rate in excess of 40 billion samples per second. An electrooptic coupler with a coupling characteristic that is asymmetric with voltage is analyzed and experimentally evaluated for consideration in the sampler.
Code-modulated path-sharing multi-antenna receivers: theory and analysis (2009)

Conventional multi-antenna receiver front-ends require multiple RF/baseband chains and analog-to-digital converters (ADC). This increases power consumption and chip area substantially. In this letter, we introduce a new Code-Modulated Path-Sharing Multi-Antenna (CPMA) receiver architecture suitable for any multi-antenna scheme including spatial multiplexing, spatial diversity, and beamforming. The receiver uses code modulation to distinguish the antenna signals before combining them in the analog domain. The combined signal propagates through shared-path blocks and all the original signals are later recovered in the digital domain for further processing. Due to the spread spectrum nature of code modulation, a larger bandwidth is needed for the blocks in the shared path. To alleviate this effect, the use of non-orthogonal coding is examined. An effective channel matrix is derived and the system capacity is evaluated in terms of the cross-correlation between signature codes. Implementation and code selection issues are discussed. Analysis and simulation results indicate that by properly selecting non-orthogonal code sets, the spreading factor, and therefore, the overall analog signal bandwidth is reduced while incurring minimal performance degradation.
Efficient quasi-phase-matched second harmonic generation in a polymer waveguide (1990)

Efficient phase matched second harmonic generation has been observed in a polymer waveguide over a distance of 0.5 cm. Phase matching is accomplished by periodic poling of a nonlinear optical polymer. The observed efficiency of 0.01 % /W is in good agreement with calculations.
On Differential Beamforming With Nonuniform Linear Microphone Arrays (2022)

While differential beamforming with uniform linear arrays (ULAs) has been widely studied, there is little work so far regarding the design of differential beamformers with nonuniform linear arrays (NULAs). This paper attempts to shed some light on the principles of differential beamforming with NULAs. We define spatial difference operators with NULAs, where any order of the spatial difference of the observation signals can be represented as the product of a nonuniform spatial difference operator matrix and the observation vector. Consequently, the design of differential beamformers is performed in two stages. In the first one, a nonuniform spatial difference operator matrix is applied to the array observations, thereby yielding differential signals. In the second stage, beamformers are designed and applied to the obtained differential signals to optimize the array performance. Based on the defined spatial difference operators, we derive from some performance metrics a family of differential beamformers with NULAs, which include the maximum directivity factor (DF), the maximum white noise gain (WNG), and the maximum front-to-back ratio (FBR) differential beamformers. To compromise between the DF and array robustness, we also derive the parameterized maximum DF and parameterized maximum FBR differential beamformers. The null-constraint maximum DF and WNG differential beamformers are also developed so that some nulls can be placed in specified directions for interference suppression. Simulation results validate the theoretical analysis and justify the properties of the proposed methods.
Palladium-Catalyzed Synthesis of Monodisperse, Controlled-Length, and Functionalized Oligoanilines (1998)

The palladium-catalyzed amination of aryl halides, in conjunction with an orthogonal protective group scheme, forms the basis of two routes to oligoaniline precursors. One method consists of a bidirectional chain growth from a symmetric core piece, whereas the other involves a divergent−convergent synthesis of nonsymmetric fragments, followed by coupling to a symmetric core fragment. The oligoaniline precursors are soluble in a variety of common organic solvents and are easily converted to the deprotected oligoanilines. The method allows the preparation of even or odd chain lengths and the incorporation of a variety of functional groups. The synthesis of phenyl-capped heptaaniline through decaaniline, of four end-functionalized octaaniline derivatives, and of phenyl-capped 16-mer and 24-mer is described. The effects of chain length and substitution upon oligomer behavior have been investigated by electronic absorption spectroscopy and cyclic voltammetry.
Control of dispersion in a femtosecond ytterbium laser by use of hollow-core photonic bandgap fiber (2004)

We demonstrate the use of photonic bandgap fiber for dispersion compensation in a short-pulse fiber laser. The anomalous dispersion provided by the photonic bandgap fiber enables us to construct a femtosecond fiber laser at 1 micron wavelength without prisms or diffraction gratings. The laser is self-starting and produces 160-fs pulses with 1-nJ energy, and represents a significant step toward all-fiber devices capable of much higher pulse energies.
Pitch and Yaw Trajectory Measurement Comparison Between Automated Video Analysis and Onboard Sensor Data Analysis Techniques (2013)

Abstract : This report is a comparison between a newly developed method and a well proven analysis process to measure the pitch and yaw behavior of an artillery projectile following cannon launch. In the new method, launch video is processed using automated computer-vision algorithms to estimate a projectile's orientation history in the interval of video coverage. For the experiments covered by this report, this interval extended from the muzzle to approximately 70 80 m downrange. The accuracy of the method's results is validated by comparing them to results obtained from processing of high-fidelity onboard measurements using the vectoring technique known as Projectile Orientation In Navigation TERms (POINTER). From this evaluation, it is shown that the automated video analysis method is correctly measuring the epicyclic motion of the projectile during the portion of flight captured by the video (first two nutation cycles). Included in the report is a general introduction of both analysis methods, as well as a brief overview of other techniques used by aeroballisticians to characterize the flight mechanics of artillery projectiles. The limits and advantages of the various methods are discussed, and future research efforts to improve results and overcome some of the shortcomings of the automated video method are identified.
Tissue specific perfusion imaging using arterial spin labeling (1994)

Quantitative magnetic resonance measurements of regional tissue perfusion can be obtained using magnetically labeled arterial water as a diffusable tracer. Continuous labeling is achieved in flowing spins using adiabatic inversion. The effects of continuous labeling of proximal arterial spins and T1 relaxation in distal tissue magnetization result in a steady-state change in tissue magnetization which is tissue specific, i.e., it can be quantified in units of blood flow per gram of tissue per unit time. This magnetization is sampled using standard imaging sequences. The theoretical basis for this method, including the effects of macromolecular spin saturation, is reviewed. Recent results demonstrating the successful implementation of this technique in vitro and in vivo in rat brain, heart, and kidney, and in human brain and kidney are presented, as well as the use of a separate RF coil for arterial labeling to produce selective perfusion images in rat brain. This approach allows quantitative perfusion images to be obtained completely non-invasively at the resolution of 1H MRI, and is useful in the clinical and investigational evaluation of organ physiology.
Maximum-likelihood estimation for semiconductor detector arrays (2002)

We propose a rigorous statistical treatment of data from semiconductor detector arrays using maximum-likelihood estimation. For pixellated and cross-striped electrodes, a single gamma-ray interaction can produce signals in multiple electrodes. The set of signals generated from a single gamma-ray interaction are random variables with a probability law dependent on the position and energy of the gamma ray. If the signals are fixed then the probability law becomes the likelihood function. The maximum-likelihood estimate is then the position and energy that maximize the likelihood. We applied this estimator to a 48/spl times/48 pixellated CdZnTe array with 125 /spl mu/m pixel spacing. The likelihood law was evaluated with Monte-Carlo integration using a model of all physical processes affecting signal generation. By simplifying the physical model such that each gamma ray can undergo only one scattering process, computation time is greatly reduced with no measurable effect on energy resolution. The energy estimates formed histograms with 7.5 keV full-width-half-maximum (FWHM) at 140 keV, and 6 keV FWHM at 60 keV. Currently used methods show at best 11 keV FWHM at 140 keV and 9 keV FWHM at 60 keV. Comparison with simulations shows that these devices behave close to our model.
Digitally Tuned Bandpass Sigma Delta Modulator for Wireless Communications (2005)

An 80 MHz, 3-level output, bandpass sigma delta modulator analog to digital converter (ADC) with complete digital tuning is presented. The proposed architecture is based on error feedback mechanism with a 64-level flash ADC, and a 3-level DAC in the loop. It yields almost constant SNR for programmable signal band that can be placed anywhere in the 2 to 38MHz band.
Mutational Analysis of the Enzymatic Domain of<i>Clostridium difficile</i>Toxin B Reveals Novel Inhibitors of the Wild-Type Toxin (2003)

Toxin B (TcdB), a major Clostridium difficile virulence factor, glucosylates and inactivates the small GTP-binding proteins Rho, Rac, and Cdc42. In the present study we provide evidence that enzymatically inactive fragments of the TcdB enzymatic domain are effective intracellular inhibitors of native TcdB. Site-directed and deletion mutants of the TcdB enzymatic region (residues 1 to 556), lacking receptor binding and cell entry domains, were analyzed for attenuation of glucosyltransferase and glucosylhydrolase activity. Five of six derivatives from TcdB(1-556) were found to be devoid of enzymatic activity. In order to facilitate cell entry, mutants were genetically fused to lfn, which encodes the protective antigen binding region of anthrax toxin lethal factor and mediates the cell entry of heterologous proteins. In line with reduced enzymatic activity, the mutants also lacked cytotoxicity. Remarkably, pretreatment or cotreatment of cells with four of the mutants provided protection against the cytotoxic effects of native TcdB. Furthermore, a CHO cell line expressing enzymatically active TcdB(1-556) was also protected by the mutant-derived inhibitors, suggesting that inhibition occurred at an intracellular location. Protection also was afforded by the inhibitor to cells treated with Clostridium sordellii lethal toxin (TcsL), which uses the same cosubstrate as TcdB but shares Rac only as a common substrate target. Finally, the inhibitor did not provide protection against Clostridium novyi alpha-toxin (Tcnalpha), which shares similar substrates with TcdB yet uses a different cosubstrate. This is the first report to demonstrate that the potential exists to inhibit toxins at their intracellular site of action by using inactive mutants.