gebhart/patrepeval huggingface dataset:
Performance of time reversal precoding technique for MISO-OFDM systems (2013)

Time reversal (TR) is considered as a promising technique for green and multi-user communications thanks to its time and space focusing properties. TR can be viewed as a precoding scheme which can be combined with orthogonal frequency division multiplexing (OFDM) and easily carried out in a multiple transmit antenna context. This paper analyzes the performance of TR for a multiple-input single-output (MISO) OFDM system and provides a comparison with maximum ratio transmission (MRT) and equal gain transmission (EGT) precoding techniques. The analytical performance of the three precoding techniques is derived by computing the capacity and the bit error rate (BER) as a function of the transmit signal-to-noise ratio (SNR). First, the capacity analysis highlights the ability of the TR system to provide higher bit rates than the MRT system at low SNRs, while the capacity of the MRT system is the highest at high SNRs. From the obtained BER analytical expressions, the diversity exploitation of each system is discussed. In particular, it is shown that the TR system only exploits half the available diversity, while the systems using EGT or MRT exploit the full diversity. Hence, contrary to what is expected from the theoretical capacity analysis, the TR system is shown to underperform the other precoding schemes in terms of BER. To overcome such a drawback, the combination of TR with classical adaptive modulation techniques is studied, allowing the achievable throughput to be increased without destroying the focusing properties of TR. It is then observed that TR takes advantage of adaptive modulations and outperforms the other schemes at low SNRs. In this study, analytical results and closed-form expressions of capacity and BER performance are provided and confirmed through Monte Carlo simulations.
EMI Reduction by Spread-Spectrum Clocking in Digitally-Controlled DC-DC Converters (2009)

This paper proposes spread-spectrum clock modulation algorithms for EMI reduction in digitally-controlled DC-DC converters. In switching regulators using PWM, switching noise and harmonic noise concentrated in a narrow spectrum around the switching frequency can cause severe EMI. Spread-spectrum clock modulation can be used to minimize EMI. In conventional switching regulators using analog control it is very difficult to realize complex spread-spectrum clocking, however this paper shows that it is relatively easy to implement spread-spectrum EMI-reduction using digital control. The proposed algorithm was verified using a power converter simulator (SCAT).
Power-performance modeling and tradeoff analysis for a high end microprocessor (2001)

Power dissipation limits constitute a key new constraint in the design of high-end microprocessors. These limits are becoming important for two main reasons:
Differential methylation of hypoxanthine phosphoribosyltransferase genes on active and inactive human X chromosomes. (1984)

Previous theoretical considerations and some experimental data have suggested a role for DNA methylation in the maintenance of mammalian X chromosome inactivation. The isolation of specific X-encoded sequences makes it possible to investigate this hypothesis directly. We have used cloned fragments of the human hypoxanthine phosphoribosyltransferase (HPRT) gene and methylation-sensitive restriction enzymes to study methylation patterns in genomic DNA of individuals with different numbers of X chromosomes and in somatic cell hybrid lines containing human X chromosomes that are either active or inactive or have been reactivated by treatment with 5-azacytidine. The results of these analyses show that there is hypomethylation of active X chromosomes relative to inactive X chromosomes in the 5' region of this gene. In the middle region of the gene, however, a site that is consistently undermethylated on inactive X chromosomes was identified. Taken together, the data suggest that the overall pattern of methylation, rather than methylation of specific sites, plays a role in the maintenance of X chromosome inactivation.
Hospital Textiles, Are They a Possible Vehicle for Healthcare-Associated Infections? (2012)

Textiles are a common material in healthcare facilities; therefore it is important that they do not pose as a vehicle for the transfer of pathogens to patients or hospital workers. During the course of use hospital textiles become contaminated and laundering is necessary. Laundering of healthcare textiles is most commonly adequate, but in some instances, due to inappropriate disinfection or subsequent recontamination, the textiles may become a contaminated inanimate surface with the possibility to transfer pathogens. In this review we searched the published literature in order to answer four review questions: (1) Are there any reports on the survival of microorganisms on hospital textiles after laundering? (2) Are there any reports that indicate the presence of microorganisms on hospital textiles during use? (3) Are there any reports that microorganisms on textiles are a possible source infection of patients? (4) Are there any reports that microorganisms on textiles are a possible source infection for healthcare workers?
Image processing for automatic surface defect detection (1989)

This paper defines a surface defect and reviews image processing algorithms for defect detection, severity measurement and classification. A number of new techniques which have been developed for use on a dedicated machine vision defect detection system are presented and their applications discussed.<
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Non‐specific, general and multiple stress resistance of growth‐restricted <i>Bacillus subtilis</i> cells by the expression of the σ<sup>B</sup> regulon (1998)

Bacillus subtilis cells respond almost immediately to different stress conditions by increasing the production of general stress proteins (GSPs). The genes encoding the majority of the GSPs that are induced by heat, ethanol, salt stress or by starvation for glucose, oxygen or phosphate belong to the sigmaB-dependent general stress regulon. Despite a good understanding of the complex regulation of the activity of sigmaB and knowledge of a very large number of general stress genes controlled by sigmaB, first insights into the physiological role of this nonspecific stress response have been obtained only very recently. To explore the physiological role of this reguIon, we and others identified sigmaB-dependent general stress genes and compared the stress tolerance of wild-type cells with mutants lacking sigmaB or general stress proteins. The proteins encoded by sigmaB-dependent general stress genes can be divided into at least five functional groups that most probably provide growth-restricted B. subtilis cells with a multiple stress resistance in anticipation of future stress. In particular, sigB mutants are impaired in non-specific resistance to oxidative stress, which requires the sigmaB-dependent dps gene encoding a DNA-protecting protein. Protection against oxidative damage of membranes, proteins or DNA could be the most essential component of sigmaB mediated general stress resistance in growth-arrested aerobic gram-positive bacteria. Other general stress genes have both a sigmaB-dependent induction pathway and a second sigmaB-independent mechanism of stress induction, thereby partially compensating for a sigmaB deficiency in a sigB mutant. In contrast to sigB mutants, null mutations in genes encoding those proteins, such as cIpP or cIpC, cause extreme sensitivity to salt or heat.
Dynamic adaptive hypermedia systems for e-learning (2008)

The ultimate goal of adaptive educational hypermedia systems (AEHS) is to provide a learning experience that is individualized to the particular needs of the learners, from the point of view of knowledge level, goals, motivation, individual differences etc. The focus of our thesis is on the learning style as the adaptation criterion, since it is one of the individual differences that play an important role in learning, according to educational psychologists. The first step towards providing adaptivity is selecting a good taxonomy of learning styles. We advocate the use of a learning style model (ULSM), which integrates characteristics from several models proposed in the literature, thus establishing a unified core vocabulary. The traditional method for diagnosing learning style implies having the students fill in a dedicated psychological questionnaire. What we propose in this thesis is an implicit modeling method, which is based on the analysis and interpretation of student behavior in the system, not requiring any additional effort from the part of the students and bypassing the reliability and validity problems of the existing learning style questionnaires. The approach was validated through experimental research, obtaining good precision results. The next step of our research was to identify the adaptation technologies that best serve learners with different learning styles and define the corresponding adaptation rules. The effectiveness was confirmed by means of an experimental study: the results obtained (student behavior, performance, efficiency and satisfaction) proved the positive effect that our adaptation to learning styles has on the learning process. Based on the methods and techniques proposed for modeling and adaptation, we designed and implemented a dedicated e-learning platform, called WELSA (Web-based Educational system with Learning Style Adaptation), which includes several functionalities: i) a course player for the students, enhanced with learner tracking capabilities and an adaptation component; ii) an analysis tool, used for identifying students' learning preferences; iii) a course editor for the teachers, to help them author courses in the required format. The final step of our research was the global evaluation of WELSA system. The analysis of students' answers to the survey instruments revealed the high degree of learner satisfaction with the system, as well as their desire to use WELSA system on an everyday basis. The subject required an interdisciplinary approach, demanding the synergy of computer science and instructional sciences (adaptive hypermedia, learning management systems, user modeling, educational psychology). The findings and results obtained in this thesis open up many research perspectives for the AEHS field in general and the learning style based adaptive educational systems in particular.
Color document image segmentation for automated document entry systems (2002)

Monochrome document image segmentation has been studied for over ten years. On the other hand, how to segment color document images is still an open research field. We propose an approach for segmenting color document images. Unlike the common practice in monochrome documents that objects are black on a white background the components in color documents can be any color. To cope with their variety, the first step of our approach is to create a binary image of edge-representation. Then page segmentation is carried out in the binary image using the CRLA procedure. Finally, we utilize the geometric features and the color information to classify the segmented blocks into text lines and picture components. The identified text lines are then further transformed into the white-background/black-text format for OCR processing. The proposed approach was implemented on a Pentium/l33 PC and the experimental results have demonstrated its feasibility.
Chemical and Histochemical Sequences in the Normal Healing of Wounds (1955)

THE healing wound is of perennial interest and fundamental importance to the surgeon. Despite continued study, however, knowledge to date consists largely of the factors that affect the well known histological sequences of healing and the rate of gain in tensile strength. The intensive inquiries1 , 2 that many investigators have conducted into the nature of connective tissue in the last decade have provided a variety of technics, some old and some new, that require application to the healing wound. This report reappraises the sequences of wound healing on the basis of data obtained from chemical and histochemical studies.Formation of Collagen . . .
Proteolytic susceptibility of the serine protease inhibitor trappin-2 (pre-elafin): evidence for tryptase-mediated generation of elafin (2005)

A number of serine, cysteine, metallo- and acid proteases were evaluated for their ability to proteolytically cleave the serine protease inhibitor trappin-2, also known as pre-elafin, and to release elafin from its precursor. None of the metalloproteases or acid proteases examined cleaved trappin-2, while serine and cysteine proteases preferentially cleaved trappin-2 within its non-inhibitory N-terminal moiety. Cathepsin L, cathepsin K, plasmin, trypsin and tryptase were able to release elafin by cleaving the Lys 38 -Ala 39 peptide bond in trappin-2. However, purified tryptase appeared to be efficient at releasing elafin. Incubation of trappin-2 with purified mast cells first challenged with anti-immunoglobulin E or calcium ionophore A23187 resulted in the rapid generation of elafin. This proteolytic release of elafin from trappin-2 was inhibited in the presence of a tryptase inhibitor, suggesting that this mast cell enzyme was involved in the process. Finally, ex vivo incubation of trappin-2 with sputum from cystic fibrosis patients indicated the production of a proteolytic immunoreactive fragment with the same mass as that of native elafin. This cleavage did not occur when preincubating the sputum with polyclonal antibodies directed against tryptase. Taken together, these findings indicate that tryptase could likely be involved in the maturation of trappin-2 into elafin under physiological conditions.
Power delivery system architecture for many-tier 3D systems (2010)

Many-tier systems are the future of 3D integration. In this work we explore power delivery system design for these large scale devices. We have developed a scalable many-tier design that contains one tier of processors and eight tiers of DRAM. These nine tiers comprise a 'set' that can be stacked any number of times. Previously, we have examined the dynamic and static power noise scaling behavior of various components of this system. Now, we present studies on two key aspects of power system architecture in these systems and their impact on power supply noise. First, we examine the addition of a dynamic noise-limiting turn-on policy and show that it can reduce dynamic power supply noise by 37% with almost no impact on system performance. Next, we present interesting results comparing different power/ground TSV topologies and show that a spread TSV distribution can lower both DC and dynamic power supply noise in the case that the many-tier stack contains low power tiers, such as memory tiers. We also show that ignoring TSV inductance when calculating dynamic noise can result in a 14.8% underestimate.
Real attacks on virtual networks (2006)

The recently proposed coordinates-based systems for network positioning have been shown to be accurate, with very low distance prediction error. However, these systems often rely on nodes coordination and assume that information reported by probed nodes is correct. In this paper, we identify different attacks against coordinates embedding systems and study the impact of such attacks on the recently proposed Vivaldi decentralized positioning system. We present a simulation study of attacks carried out by malicious nodes that provide biased coordinates information and delay measurement probes. We experiment with attack strategies that aim to (i) introduce disorder in the system, (ii) fool honest nodes to move far away from their correct positions and (iii) isolate a particular node in the system through collusion. Our findings confirm the susceptibility of the Vivaldi System to such attacks.
Growth and device performance of InP/GaAsSb HBTs (2003)

We report the growth of high-quality InP/GaAsSb heterojunction bipolar transistors (HBTs) for high-frequency applications by metalorganic vapor phase epitaxy (MOVPE) and gas-source molecular beam epitaxy (GSMBE) using carbon as a base dopant. Hole concentrations above 10/sup 20/ cm/sup -3/ are achieved in a carbon-doped GaAsSb base layer. We measure type I and type II luminescence from InP/GaAsSb/InAlAs and GaAsSb/InP superlattices to evaluate quickly the HBT's GaAsSb base layer and collector-base and base-emitter heterojunction quality. The HBTs exhibit excellent DC characteristics and a current gain cutoff frequency over 210 GHz.
Methylphenidate and Children With Attention Deficit Disorder (1985)

The short-term, dose-response effects of methylphenidate hydrochloride were evaluated on academic and social classroom measures in 29 children with attention deficit disorder. In a double-blind, cross-over design with order randomized, children received a placebo for two weeks and three doses of methylphenidate hydrochloride (0.15 mg/kg, 0.3 mg/kg, and 0.6 mg/kg) for one week each. Dependent measures included the output and accuracy of performance in grade-appropriate reading comprehension workbooks and arithmetic problems, spelling word acquisition, and observations of disruptive and on-task behavior. Beneficial drug effects and linear dose-response curves on all dependent measures were found. The results suggest that beneficial methylphenidate effects on classroom behavior may be accompanied by enhanced academic achievement in some hyperactive children.
A graphical model representation of the track-oriented multiple hypothesis tracker (2012)

The track-oriented multiple hypothesis tracker is currently the preferred method for tracking multiple targets in clutter with medium to high computational resources. This method maintains a structured representation of the track posterior distribution, which it repeatedly extends and optimizes over. This representation of the posterior admits probabilistic inference tasks beyond MAP estimation that have yet to be explored. To this end we formulate the posterior as a graphical model and show that belief propagation can be used to approximate the track marginals. These approximate marginals enable an online parameter estimation scheme that improves tracker performance in the presence of parameter misspecification.
The Potential of Immune Biomarkers to Advance Personalized Medicine Approaches for Schizophrenia (2015)

Molecular profiling studies have helped increase the understanding of the immune processes thought to be involved in the etiology and pathophysiology of psychiatric disorders such as schizophrenia. Current therapeutic interventions with first- and second-generation antipsychotics are suboptimal. Poor response rates and debilitating side effects often lead to poor treatment compliance. This highlights the pressing need to identify more effective treatments as well as objective biomarker based tests, which can help predict treatment response and identify diagnostic subpopulations. Such tests could enable early detection of patients who will benefit from particular therapeutic interventions. In this review, we discuss studies relating to dysfunctions of the immune system in patients with schizophrenia and the effects of antipsychotic medication on the molecular components of these systems. Immune system dysfunction may in part be related to genetic risk factors for schizophrenia, but there is substantial evidence that a wide range of environmental factors ranging from exposure to infectious agents such as influenza and Toxoplasma gondii to HPA axis dysfunction play an important role in the etiopathogenesis of schizophrenia. Ongoing research efforts, testing therapeutic efficacy of anti-inflammatory agents used as add-on medications are also discussed. From a therapeutic perspective, these represent the initial steps toward novel treatment approaches and more effective patient care in the field of mental health.
Stereochemistry of reduction and methylation of 5-(trimethylsilyl)adamantan-2-one and 5-(trimethylstannyl)adamantan-2-one (1989)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereochemistry of reduction and methylation of 5-(trimethylsilyl)adamantan-2-one and 5-(trimethylstannyl)adamantan-2-oneMei Xie and W. J. Le NobleCite this: J. Org. Chem. 1989, 54, 16, 3836–3839Publication Date (Print):August 1, 1989Publication History Published online1 May 2002Published inissue 1 August 1989https://pubs.acs.org/doi/10.1021/jo00277a018https://doi.org/10.1021/jo00277a018research-articleACS PublicationsRequest reuse permissionsArticle Views207Altmetric-Citations35LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Monte carlo analysis of electron transport in small semiconductor devices including band-structure and space-charge effects (1988)

The physics of electron transport in Si and GaAs is investigated with use of a Monte Carlo technique which improves the "state-of-the-art" treatment of high-energy carrier dynamics. (1) The semiconductor is modeled beyond the effective-mass approximation by using the band structure obtained from empirical-pseudopotential calculations. (2) The electron-phonon, electron-impurity, and electron-electron scattering rates are computed in a way consistent with the full band structure of the solid, thus accounting for density-of-states and matrix-element effects more accurately than previous transport formulations. (3) The long-range carrier-carrier interaction and space-charge effects are included by coupling the Monte Carlo simulation to a self-consistent two-dimensional Poisson solution updated at a frequency large enough to resolve the plasma oscillations in highly doped regions. The technique is employed to study experimental submicrometer Si field-effect transistors with channel lengths as small as 60 nm operating at 77 and 300 K. Velocity overshoot and highly nonlocal, off-equilibrium phenomena are investigated together with the role of electron-electron interaction in these ultrasmall structures. In the systems considered, the inclusion of the full band structure has the effect of reducing the amount of velocity overshoot via electron transfer to upper conduction valleys, particularly at large biases and low temperatures. The reasonableness of the physical picture is supported by the close agreement of the results of the simulation to available experimental data.
Long term effects of locomotor training in spinal humans (2001)

The long term effects of locomotor training in patients with spinal cord injury (SCI) were studied. In patients with complete or incomplete SCI coordinated stepping movements were induced and trained by bodyweight support and standing on a moving treadmill. The leg extensor muscle EMG activity in both groups of patients increased significantly over the training period, associated with improved locomotor ability in those with incomplete SCI. During a period of more than 3 years after training, the level of leg extensor EMG remained about constant in incomplete SCI in those who regularly maintained locomotor activity. By contrast the EMG significantly fell in those with complete SCI. The results suggest a training induced plasticity of neuronal centres in the isolated spinal cord which may be of relevance for future interventional therapies.