gebhart/patrepeval huggingface dataset:
Design and Simulation of Electron Gun for a Multibeam Klystron (2012)

This paper represents the design of multi-beam (sixty-beam) electron gun and focusing system for high power, compact klystron. The beam voltage is 4 kV with a total beam current of 513 (8.55 × 60) mA which is equally divided among sixty-beam. Each beam has a perveance of 0.033 μP making a total gun perveance of 2.02 μP corresponding to a total beam power of more than 2 kW. The cathode radius is7 mm and individual emitter radius is 0.2 mm having current density 6.7 A/cm2. The design has been accomplished using OPERA 3D code. All beamlets have individual anode as well as BFE and a common focusing system. Potential difference between cathode and anode is 4 kV. A magnetic field of 1200 Gauss is applied along the beam axis. A major challenge for the development of multi-beam klystron is design and technology for the focusing of off-axis beamlets because off-axis beams are at various azimuths.
Neuroprotective potency of kynurenic acid against excitotoxicity (2000)

The aim of this study was to determine in vivo which extracellular levels of kynurenic acid (KYNA) are required to control excessive NMDA receptor activation in the rat cortex. As excitotoxicity is coupled to marked ion movements, local depolarisations induced by perfusion of NMDA or quinolinic acid (QUIN) through microdialysis probes were recorded at the site of excitotoxin application. Perfusion of KYNA through the dialysis fibre inhibited the excitotoxin responses with an IC50 of 32-66 microM (extracellular concentration corrected for microdialysis delivery), but > 10-fold lower levels of endogenous KYNA were reported to be neuroprotective. Accordingly, these results strengthen the notion that KYNA accumulation may protect the brain parenchyma by acting on different molecular target(s), besides the NMDA receptor glycine site.
A Neural Network Approach for the Control of a Tracking Behavior (1991)

The problem of correctly evaluating noisy and incorrect data for the interpretation of ultrasonic sensor signals is an often encountered one. Neural networks, with their inherent characteristics of adaptivity and high fault- and noise-tolerance are well suited for such tasks. In this paper two neural network approaches are described for the control of the tracking behavior of an autonomous mobile robot. Input data are provided by a set of ultrasonic sensors mounted at the front of the vehicle. Two neural network learning strategies: backpropagation and reinforcement learning, are examined in a simulation and compared with respect to learning speed, capacity of tracking and the effort required to adapt the control networks of the real vehicle. >
Image Segmentation for Fruit Detection and Yield Estimation in Apple Orchards (2016)

Ground vehicles equipped with monocular vision systems are a valuable source of high resolution image data for precision agriculture applications in orchards. This paper presents an image processing framework for fruit detection and counting using orchard image data. A general purpose image segmentation approach is used, including two feature learning algorithms; multi-scale Multi-Layered Perceptrons (MLP) and Convolutional Neural Networks (CNN). These networks were extended by including contextual information about how the image data was captured (metadata), which correlates with some of the appearance variations and/or class distributions observed in the data. The pixel-wise fruit segmentation output is processed using the Watershed Segmentation (WS) and Circular Hough Transform (CHT) algorithms to detect and count individual fruits. Experiments were conducted in a commercial apple orchard near Melbourne, Australia. The results show an improvement in fruit segmentation performance with the inclusion of metadata on the previously benchmarked MLP network. We extend this work with CNNs, bringing agrovision closer to the state-of-the-art in computer vision, where although metadata had negligible influence, the best pixel-wise F1-score of $0.791$ was achieved. The WS algorithm produced the best apple detection and counting results, with a detection F1-score of $0.858$. As a final step, image fruit counts were accumulated over multiple rows at the orchard and compared against the post-harvest fruit counts that were obtained from a grading and counting machine. The count estimates using CNN and WS resulted in the best performance for this dataset, with a squared correlation coefficient of $r^2=0.826$.
Query-Efficient Black-Box Attack by Active Learning (2018)

Deep neural network (DNN) as a popular machine learning model is found to be vulnerable to adversarial attack. This attack constructs adversarial examples by adding small perturbations to the raw input, while appearing unmodified to human eyes but will be misclassified by a well-trained classifier. In this paper, we focus on the black-box attack setting where attackers have almost no access to the underlying models. To conduct black-box attack, a popular approach aims to train a substitute model based on the information queried from the target DNN. The substitute model can then be attacked using existing white-box attack approaches, and the generated adversarial examples will be used to attack the target DNN. Despite its encouraging results, this approach suffers from poor query efficiency, i.e., attackers usually needs to query a huge amount of times to collect enough information for training an accurate substitute model. To this end, we first utilize state-of-the-art white-box attack methods to generate samples for querying, and then introduce an active learning strategy to significantly reduce the number of queries needed. Besides, we also propose a diversity criterion to avoid the sampling bias. Our extensive experimental results on MNIST and CIFAR-10 show that the proposed method can reduce more than 90% of queries while preserve attacking success rates and obtain an accurate substitute model which is more than 85% similar with the target oracle.
Gamma-induced attenuation in normal single-mode and multimode, Ge-doped and P-doped optical fibers: A fiber optic dosimeter for low dose levels (2000)

Ge-doped, P-doped, normal single-mode (SM) and multimode (MM) optical fibers were exposed to Cobalt-60 gamma radiation at dose rates of 0.5 and 3.0 Gy/min, typical radiotherapy dose rates. A CCD-based fiber optic spectrometer was used to measure the real-time absorption spectra of these fibers in the visible region. Experimental results have shown that P-doped fiber is the most radiation-sensitive of the fibers tested. At the wavelength of 502 nm, the radiation-induced loss in P-doped fiber shows a linear relationship with the total dose with no dose-rate dependence. This indicates that dose rates have no influence on a fiber optic dosimeter operating at this wavelength. The radiation-induced losses in normal MM fibers, Ge-doped MM fibers, and Ge-doped SM fibers are shownto be dose-rate dependent. PACS No.: 42.62nBe, 42.81-i
InGaN/GaN multiple quantum well solar cells with long operating wavelengths (2009)

We report on the fabrication and photovoltaic characteristics of InGaN solar cells by exploiting InGaN/GaN multiple quantum wells (MQWs) with In contents exceeding 0.3, attempting to alleviate to a certain degree the phase separation issue and demonstrate solar cell operation at wavelengths longer than previous attainments (&gt;420 nm). The fabricated solar cells based on In0.3Ga0.7N/GaN MQWs exhibit an open circuit voltage of about 2 V, fill factor of about 60%, and an external efficiency of 40% (10%) at 420 nm (450 nm).
CHINA'S AFGHAN POLICY: THE FORMING OF THE "March WEST" STRATEGY? (2016)

Traditionally, Afghanistan has been a low diplomatic priority for China, and China did not have strong influence there. But recent years have found that as the U.S. is to withdraw its troops from Afghanistan and China's interests in the country are rapidly growing, Beijing has adjusted its stance from cultivated disinterest to growing engagement. Indeed, from a broader perspective, Afghanistan is an ideal channel for China to implement its March West strategy ? to expand its economic and strategic influence to Central Asia, the Middle East and beyond.
A comparative study of spectral clustering for i-vector-based speaker clustering under noisy conditions (2015)

The present paper dealt with speaker clustering for speech corrupted by noise. In general, the performance of speaker clustering significantly depends on how well the similarities between speech utterances can be measured. The recently proposed i-vector-based cosine similarity has yielded the state-of-the-art performance in speaker clustering systems. However, this similarity often fails to capture the speaker similarity under noisy conditions. Therefore, we attempted to examine the efficiency of spectral clustering on i-vector-based similarity for speech corrupted by noise because spectral clustering can yield robustness against noise by non-linear projection. Experimental comparisons demonstrated that spectral clustering yielded significant improvement from conventional methods, such as agglomerative clustering and k-means clustering, under non-stationary noise conditions.
The dimensionality effect on phonon localization in graphene/hexagonal boron nitride superlattices (2020)

Abstract Phonon localization, a largely elusive phenomenon, has a great promise for improving current applications like thermoelectric materials and thermal barrier coatings. By freezing the out-of-plane atomic motion in graphene/hexagonal boron nitride (hBN) superlattices and random multilayers, i.e aperiodic superlattices, we are able to completely isolate the effect of the third dimension on phonon scattering and localization in 2D materials. In particular, we find much more prominent phonon heat conduction and localization when atomic motions in the third dimension are frozen. Rigorous spectral phonon transmission and scattering phase space analyses reveal that the phase-breaking anharmonic scatterings can significantly hinder the occurrence of phonon localization. Phonon participation ratio calculations further reveal that the flexural modes—arising from the degree of freedom of the third dimension—are rather extended, in contrast to the vastly localized in-plane modes in graphene/hBN random multilayers. These two factors altogether greatly obstruct the observation of coherent phonon localization in realistic materials. This work will be useful for guiding the search for nanostructures possessing significant phonon localization behaviors.
Metal-Insulator-Semiconductor Photodetectors (2010)

The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.
The emergence of digital ecosystem governance: An investigation of responses to disrupted resource control in the Swedish public transport sector (2022)

Abstract Digital ecosystem governance entails the management of complex, dynamic power relationships. As entrant platform providers seek to cultivate an ecosystem, they must carefully navigate these power relationships when dealing with governance tensions. Providers generally seek to leverage the ecosystem's generative potential by facilitating a variety of interactions and distributing design rights. Simultaneously, they need to ensure stability and order by imposing rules that resolve contentious matters and restrict ecosystem participants' degrees of freedom. This study explores how and why providers can induce ecosystem actors to engage in collaborative negotiation regarding such governance tensions through a case study of the introduction of an open data platform in the Swedish public transport sector. Our analysis offers three main contributions. First, it provides an empirical demonstration that entrepreneurial threats, as well as opportunities, can trigger platform launches and drive collaborative negotiation of digital ecosystem governance. Second, it extends conceptualizations of boundary resources beyond the current focus on transactional elements by demonstrating the role of interactive boundary resources in the negotiation of governance grounded in both social and systemic power relationships. Third, it shows how positive reinforcement can complement punitive measures to increase acceptance of design rules.
The behavior of pinned layers using a high-field transfer curve (2005)

In order to study the magnetic behaviors of pinned layers under different conditions, we applied compressive mechanical stress to a device and measured the transfer curve changes using a high-field (10 kOe) quasi-static tester. This permitted us to determine the behaviors of the pinned layers and the free layer. The results of the transfer curve measurements led to a classification of these curves. The governing conditions for each category were also determined. A normal transfer curve occurs when "E/sub j/>E/sub u//spl Gt/E/sub k/(AP1) and E/sub k/(AP2)," where: AP1 is the pinned layer adjacent to the antiferromagnetic (AFM) layer; AP2 is the pinned layer adjacent to the spacer; E/sub u/ is the coupling energy constant between the antiferromagnetic layer and the AP1; E/sub j/ is the anti-parallel coupling energy constant between AP1 and AP2 through the Ru; and E/sub k/(AP1) and E/sub k/(AP2) are the induced uniaxial anisotropic energy constants in AP1 and AP2 due to magnetostriction resulting from stress applied giant magnetoresistive (GMR) sensor.
Efficacy and Tolerance of Long‐Term, High‐Dose Gabapentin: Additional Observations (1994)

Gabapentin (GBP) has shown antiepileptic efficacy and good tolerance in clinical trials. Much remains to be learned about its clinical use. As a participating center in the US Gabapentin Study Group, we report observations that have practical implications for patient management. Twenty-three patients with intractable partial-onset seizures initiated open-label treatment after a blinded placebo-controlled add-on dose efficacy study. In the titration phase, GBP and concurrent antiepileptic drugs (AEDs) were adjusted to achieve optimal efficacy on maximally tolerated GBP doses. Nine patients had no significant improvement in seizure control and discontinued GBP. The remaining 14 patients were observed while treated long-term with stable-dose GBP and concurrent AEDs. Improvement was maintained as long as patients were followed: < or = 4 years. The protocol-allowed upper dose limit, 2,400 mg/day, was well tolerated by 16 of 23 patients, indicating that higher doses may be tolerated. GBP discontinuation did not cause rebound increases in seizure frequency. The most common adverse events (AEs) (in 14 of 23) were similar to those induced by concurrent AEDs and responded to reduction of concurrent AEDs. Many patients reported positive psychostimulatory effects. These observations extend previous findings indicating that GBP is an effective and well-tolerated drug for treatment of partial-onset seizures.
Distinct DNA methylomes of newborns and centenarians (2012)

Human aging cannot be fully understood in terms of the constrained genetic setting. Epigenetic drift is an alternative means of explaining age-associated alterations. To address this issue, we performed whole-genome bisulfite sequencing (WGBS) of newborn and centenarian genomes. The centenarian DNA had a lower DNA methylation content and a reduced correlation in the methylation status of neighboring cytosine--phosphate--guanine (CpGs) throughout the genome in comparison with the more homogeneously methylated newborn DNA. The more hypomethylated CpGs observed in the centenarian DNA compared with the neonate covered all genomic compartments, such as promoters, exonic, intronic, and intergenic regions. For regulatory regions, the most hypomethylated sequences in the centenarian DNA were present mainly at CpG-poor promoters and in tissue-specific genes, whereas a greater level of DNA methylation was observed in CpG island promoters. We extended the study to a larger cohort of newborn and nonagenarian samples using a 450,000 CpG-site DNA methylation microarray that reinforced the observation of more hypomethylated DNA sequences in the advanced age group. WGBS and 450,000 analyses of middle-age individuals demonstrated DNA methylomes in the crossroad between the newborn and the nonagenarian/centenarian groups. Our study constitutes a unique DNA methylation analysis of the extreme points of human life at a single-nucleotide resolution level.
On the comparison between code-index modulation and spatial modulation techniques (2015)

Recently, two promising modulation techniques have been developed aiming to increase data rate and save energy while being simple to implement. These modulation schemes belong to two different communication methods, however, they share the common structure of using an index as an additional parameter to convey information. The first scheme known as spatial modulation (SM), is a scheme that uses multiple antennas at the transmitter side where just one antenna is activated at a time and its index is used as means to convey information. The second is known as code-index modulation (CIM), a system that uses multiple spreading codes, where a certain code is selected and its index is used as a mechanism to ferry data. In this paper, we present these two modulation techniques and we discuss the associated set of challenges for each scheme. Moreover, in order to evaluate the advantages and disadvantages of each technique, we compare the energy efficiency, the system complexity, and the bit error rate performance of the SM and CIM schemes.
Blind separation of second-order nonstationary and temporally colored sources (2002)

This paper presents a method of blind source separation that jointly exploits the nonstationarity and temporal structure of sources. The method needs only multiple time-delayed correlation matrices of the observation data, each of which is evaluated at a different time-windowed data frame, to estimate the demixing matrix. We show that the method is quite robust with respect to the spatially correlated but temporally white noise. We also discuss the extension of some existing second-order blind source separation methods. Extensive numerical experiments confirm the validity of the proposed method.
Effect of site specifically located mitomycin C-DNA monoadducts on in vitro DNA synthesis by DNA polymerases (1993)

A series of site-specifically modified oligodeoxynucleotides were synthesized that contained either of the two known mitomycin C-DNA monoadducts. In vitro DNA synthesis was carried out on some of these templates using a modified bacteriophage T7 DNA polymerase (Sequenase), AMV reverse transcriptase, and two different varieties of Escherichia coli DNA polymerase I (Klenow fragment)--one that carries the normal 3'-->5' exonuclease activity and a mutant protein that lacks this enzymatic function. Regardless of the type of DNA polymerase being used, DNA synthesis was terminated nearly quantitatively at the nucleotide 3' to each of these two monoadduct sites, although primer extension to full length of the template was noted with the unmodified control template. Substitution of Mn2+ for Mg2+ at a high concentration of the deoxynucleotide triphosphates resulted in incorporation of nucleotides opposite the adduct in the incubations with Sequenase or the 3'-->5' exonuclease-free Klenow fragment; however, primer extension beyond the adduct site did not take place. These studies demonstrated that the mitomycin monoadducts are strong blocks of replication and are likely to be toxic lesions in vivo. Since previous molecular modeling studies and molecular mechanical calculations indicated that the mitomycin adduction does not induce severe distortions at the site of adduction, a lack of base-pairing ability of the modified base in the extended product is unlikely to be the reason for the inhibitory effect. Instead, energy-minimized structural models indicated that additional hydrogen-bonding interactions have been introduced by the mitomycin moiety, and perhaps this increased thermodynamic stabilization of a distorted structure of the replication fork, in turn, may block the replication bypass. Experimental evidence of increased thermodynamic stability was provided by thermal melting of a template/primer complex that presumably a polymerase encounters in a typical replication fork. Consistently higher Tm of the adducted "replication fork" was noted when compared to its unmodified counterpart.
<i>Ly6a</i> Differential Expression in Blood–Brain Barrier Is Responsible for Strain Specific Central Nervous System Transduction Profile of AAV-PHP.B (2019)

Adeno-associated virus (AAV) gene therapy for neurological diseases was revolutionized by the discovery that AAV9 crosses the blood-brain barrier (BBB) after systemic administration. Transformative results have been documented in various inherited diseases, but overall neuronal transduction efficiency is relatively low. The recent development of AAV-PHP.B with ∼60-fold higher efficiency than AAV9 in transducing the adult mouse brain was the major first step toward acquiring the ability to deliver genes to the majority of cells in the central nervous system (CNS). However, little is known about the mechanism utilized by AAV to cross the BBB, and how it may diverge across species. In this study, we show that AAV-PHP.B is ineffective for systemic CNS gene transfer in the inbred strains BALB/cJ, BALB/cByJ, A/J, NOD/ShiLtJ, NZO/HILtJ, C3H/HeJ, and CBA/J mice, but it is highly potent in C57BL/6J, FVB/NJ, DBA/2J, 129S1/SvImJ, and AKR/J mice and also the outbred strain CD-1. We used the power of classical genetics to uncover the molecular mechanisms AAV-PHP.B engages to transduce CNS at high efficiency, and by quantitative trait locus mapping we identify a 6 Mb region in chromosome 15 with an logarithm of the odds (LOD) score ∼20, including single nucleotide polymorphisms in the coding region of 9 different genes. Comparison of the publicly available data on the genome sequence of 16 different mouse strains, combined with RNA-seq data analysis of brain microcapillary endothelia, led us to conclude that the expression level of <i>Ly6a</i> is likely the determining factor for differential efficacy of AAV-PHP.B in transducing the CNS across different mouse strains.