gebhart/patrepeval huggingface dataset:
Concurrent Estimation of a PLL Transfer Function by Cross-Correlation with pseudo-random Jitter (2019)

PLL parameters like phase margin influence the overall performance of an IC. For safety-critical ICs, PLL parameters should be measured not only once in production test, but also in the field, preferably continuously, i.e. concurrent to the application mode. The paper proposes a way to measure PLL parameters by adding pseudo-random noise to the clock signal or using a signal that is available anyway e.g. for dithering purposes to avoid spurious tones, and to calculate the crosscorrelation of this pseudo-random noise signal and the output signal of the PLL's phase detector. The result of this correlation allows for calculating the PLL's impulse response w.r.t. the phase of its input clock. This impulse response can be used to calculate the phase margin and other parameters of the PLL. Detailed simulation results are presented.
Fabrication of Hierarchical Structures on a Polymer Surface to Mimic Natural Superhydrophobic Surfaces (2007)

Biomimetic superhydrophobic surfaces successfully fabricated on high-density polyethylene surfaces by simple heat- and pressure-driven imprinting methods using patterned anodic aluminum oxides as replication templates are reported. On measuring the water contact angle (see figure), it is clearly observed that the nanostructures and microstructures together influence the superhydrophobicity of the polymer surface. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2007/c0820_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Industrial application of cold cathodes based on field emission in microwave devices (2002)

In cross-field microwave devices the total operating current usually consists of two components: the primary excitation current and the main operating current built up by the secondary electrons. As a source of primary current the cathode based on a cold field emission could be used]. Cold cathodes based on the phenomenon of field emission have a number of advantages over regular thermionic emission cathodes. They emit electrons at room temperature, do not require warm-up time, and are capable of producing very high current densities. However, cold cathodes are very sensitive to the bombardment by ions of residual gases, which sputter the cathode surface material and cause degradation of cathode's characteristics. Generally the cathode consists of the series of film field and secondary emitters placed on the supporting rod. When the cathode is operated within a strong electric field with sufficient magnitude to cause field emission, electrons will begin to leave the emitter's surface. Electrons within the interaction space will be accelerated toward the anode and will follow trajectories consistent with the electric and magnetic fields present within the magnetrons interaction space. Some of these dislodged electrons will return to the cathode with enough energy to dislodge further electrons. These dislodged electrons will enter the interaction space and the process repeats itself until high voltage is removed from the device.
An Upper Bounding Technique on the Error Floor Performance of LDPC Codes (2017)

Low-density parity-check (LDPC) codes have higher coding gains compared to algebraic codes in several configurations. However, unlike algebraic codes whose performance can be easily determined generally, the block error rate performance of an LDPC code needs to be obtained by simulations. While there are analytical methods for some structured LDPC codes that predict this performance in the low error rate regime, these provide little insight into the error floor of other (less structured) LDPC codes. In this article, we present a simple method to upper bound the error floor of LDPC codes based on a certain monotonicity assumption on the decoder. This upper bound is general enough so that under the monotonicity assumption it is valid for any error-correcting code. This upper bounding technique is useful when projecting very low block error rates (such as below 1E-14) for LDPC codes and there is no knowledge of the trapping sets.
On Utilizing Test Cube Properties to Reduce Test Data Volume Further (2012)

Test data compression has become a dominant approach to reduce the test cost today. Majority of test compression schemes are based on the fact that the generated test cubes have very few specified bits. This paper studies additional test cube properties and utilizes them to reduce the test data volume (TDV) further. Two approaches are proposed in this paper. The first one requires no additional hardware and the second one is based on the new DFT hardware, named background chains. The proposed approaches can be combined with other test compression schemes to achieve additional TDV reduction. The experimental results based on embedded deterministic test (EDT) show the proposed approaches achieve significant TDV reduction for industrial designs.
Efficient electromechanical (E/M) impedance measuring method for active sensor structural health monitoring (2005)

Electro-mechanical impedance method is emerging as an important and powerful technique for structural health monitoring. The E/M impedance method utilizes as its main apparatus an impedance analyzer that reads the in-situ E/M impedance of the piezoelectric wafer active sensors (PWAS) attached to the monitored structure. Present-day impedance analyzer equipments (e.g. HP4194) are bulky, heavy and expensive laboratory equipment that cannot be carried into the field for on-site structural health monitoring. To address this issue, several investigators have explored means of miniaturizing the impedance analyzer making the impedance analyzer more compact and field-portable. In this paper we present an improved algorithm for efficient measurement of the E/M impedance using PWAS transducers. Instead of using a sine wave as the excitation signal to the PWAS and slowly changing its frequency, our method utilizes a chirp signal which is abundant in frequency components. By applying Fast Fourier Transform (FFT) to both the input and response signals, the impedance spectrum of the PWAS is acquired. The algorithm was implemented and tested in a real-time system, which consists of excitation signal generation module, voltage and current measurement module and digital signal acquisition module. The size and the implementation of the overall system using either a laptop or a digital signal processor (DSP) are also discussed. Finally, practical results are presented and comparatively examined.
FIR Filter Design Using Optimal Factoring: A Walkthrough and Summary of Benefits (2016)

Decomposing an FIR filter into a cascade of blocks, each representing an optimal factor of H(z), the filter?s transfer function, can start with the complex-conjugate pairs of zeros of H(z) and then creating optimal pairings of these zero-pairs. This leads to a general method for designing FIR filters having minimal hardware complexity. We illustrate this concept, further techniques, benefits, and performance improvements in this paper, highlighting the practical features of the design method. It is also shown that the resulting structure can achieve lower hardware complexity, when compared with the prior art.
A Theory of Multiplication Noise for Electron Multiplying CMOS Image Sensors (2014)

An electron multiplying CMOS images sensor (emCMOS) enables electron multiplication inside the pixel by the use of high voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(hv\) </tex-math></inline-formula> ) phase(s) under gate(s). Different possible implementations of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">\(hv\) </tex-math></inline-formula> gates dedicated to impact ionization require specific multiplication patterns and therefore new excess noise formulation. This paper presents a rigorous mathematical approach to the calculation of the excess noise factor for all electron multiplying CMOS pixel structures in the framework of the branching processes and the compounding theorem of the probability generating function. Validation of the model is performed by computing the variance formula for one pixel structure and its corresponding Monte Carlo simulation of the stochastic processes. The signal over noise ratio including the readout noise, SNR <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><sub>ro</sub></i> , is introduced to evaluate the possible extreme low light imaging performance as a function of the multiplication parameters.
Total Synthesis of Ciguatoxin CTX3C (2001)

More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered the isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. The large (3 nanometers long) and complicated molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. Our highly convergent strategic approach featuring the chemoselective ring-closing metathesis reaction as a key tactic has enabled the total synthesis of ciguatoxin CTX3C, which will provide a practical supply for further studies.
A framework for evaluating storage system dependability (2004)

Designing storage systems to provide business continuity in the face of failures requires the use of various data protection techniques, such as backup, remote mirroring, point-in-time copies and vaulting, often in concert. Predicting the dependability provided by such compositions of techniques is difficult, yet necessary for dependable system design. We present a framework for evaluating the dependability of data storage systems, including both individual data protection techniques and their compositions. Our models estimate storage system recovery time, data loss, normal mode system utilization and operational costs under a variety of failure scenarios. We demonstrate the effectiveness of these modeling techniques through a case study using real-world storage system designs and workloads.
Morphology of Human Embryonic Stem Cells and Induced Pluripotent Stem Cells Cultured in Feeder Layer-Free Conditions (2011)

While the culturing of human embryonic stem cells (hESCs) and induced pluripotent cells (iPSCs) with mouse embryonic fibroblasts (MEFs) or human foreskin fibroblasts may be adequate for research purposes, it is less suitable for clinical and industrial use due to the risk of exposure of the cells to animal pathogens and to variations between batches of MEFs and fetal bovine serum (FBS). To establish reproducible and defined cultures, devoid of animal products, feeder layers and ­animal products need to be replaced. This chapter describes layer-free culture ­systems that have been developed specifically for iPSCs.
High performance interband cascade lasers at 3.8 microns (2012)

An interband cascade laser design has been grown by molecular beam epitaxy using uncracked arsenic and antimony sources. Lasers were fabricated into both broad-area and narrow-ridge devices, with cavity lengths ranging between 1 mm and 4 mm. At 300K, under low-duty-cycle pulsed conditions, threshold current densities for lasers with 2-mm cavity lengths are as low as 395 A/cm<sup>2</sup>, with optical emission centered at a wavelength of ~3.82 μm at 300 K. Continuous-wave (cw) performance of the narrow-ridge devices has been achieved for temperatures up to almost 60°C. We present results of both pulsed (broad-area and ridge) and cw (ridge only) measurements on these lasers, including L-I-V, spectral, cavity-length, and Hakki-Paoli analyses.
Quantitative Frequency-Domain Passive Cavitation Imaging (2016)

Passive cavitation detection has been an instrumental technique for measuring cavitation dynamics, elucidating concomitant bioeffects, and guiding ultrasound therapies. Recently, techniques have been developed to create images of cavitation activity to provide investigators with a more complete set of information. These techniques use arrays to record and subsequently beamform received cavitation emissions, rather than processing emissions received on a single-element transducer. In this paper, the methods for performing frequency-domain delay, sum, and integrate passive imaging are outlined. The method can be applied to any passively acquired acoustic scattering or emissions, including cavitation emissions. To compare data across different systems, techniques for normalizing Fourier transformed data and converting the data to the acoustic energy received by the array are described. A discussion of hardware requirements and alternative imaging approaches is additionally outlined. Examples are provided in MATLAB.
From audio-only to audio and video text-to-speech (2004)

Assessing the quality of Text-to-Speech (TTS) systems is a complex problem due to the many modules involved that address different subtasks during synthesis. Adding face synthesis – the animation of a “talking head ” and its rendering to video – to a TTS system makes evaluation even more difficult. In the case of talking heads, today, we are at the infancy of research towards evaluating such systems. This paper reports on progress made with the AT&amp;T sample-based Visual TTS (VTTS) system. Our system incorporates unit-selection synthesis (now well known from Audio TTS) and a moderate-size recorded database of video segments that are modified and concatenated to render the desired output. Given the high quality the system achieves, we feel for the first time that we are close to passing the Turing test, that is, that we are almost able to synthesize “talking heads ” that look like recordings of real people. We demonstrate this point in applications, either over the web (client/server), or in stand-alone form, in a kiosk setting. Several steps are necessary to assure a very high quality sample based VTTS system. First, highly accurate image analysis tools are important for creating the necessary video clip databases. The problem is compounded by the fact that facial videos cannot be stored whole due to unfavorable combinatorics: for a given synthetic sequence, it is very unlikely that a whole face video clip contains the correct mouth sequence, the appropriate eye sequence, and also a suitable “background ” face, given what we want to synthesize. Consequently, separate parts of a synthetic face need to be accessible independently from each other
A potentiostat based on a voltage-controlled current source for use with amperometric gas sensors (1992)

Amperometric gas-sensing devices develop a current that is proportional to the concentration of gas that is supplied to them. The circuit that maintains electrochemical stability in the sensor as well as buffering the current output is called a potentiostat. Some sensors used for gas sensing have very large electrode capacitances, which can result in instability with conventional potentiostat designs. The responses of two potentiostat designs to a gas were compared. One is based on conventional use of a current-to-voltage converter (CVC); the second is a new design which uses a voltage-controlled current source (VCCS). A frequency analysis of the VCCS potentiostat design is included.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Novel Chemically Modified Curcumin (CMC) Derivatives Inhibit Tyrosinase Activity and Melanin Synthesis in B16F10 Mouse Melanoma Cells (2021)

Skin hyperpigmentation disorders arise due to excessive production of the macromolecular pigment melanin catalyzed by the enzyme tyrosinase. Recently, the therapeutic use of curcumin for inhibiting tyrosinase activity and production of melanin have been recognized, but poor stability and solubility have limited its use, which has inspired synthesis of curcumin analogs. Here, we investigated four novel chemically modified curcumin (CMC) derivatives (CMC2.14, CMC2.5, CMC2.23 and CMC2.24) and compared them to the parent compound curcumin (PC) for inhibition of in vitro tyrosinase activity using two substrates for monophenolase and diphenolase activities of the enzyme and for diminution of cellular melanogenesis. Enzyme kinetics were analyzed using Lineweaver-Burk and Dixon plots and nonlinear curve-fitting to determine the mechanism for tyrosinase inhibition. Copper chelating activity, using pyrocatechol violet dye indicator assay, and antioxidant activity, using a DPPH radical scavenging assay, were also conducted. Next, the capacity of these derivatives to inhibit tyrosinase-catalyzed melanogenesis was studied in B16F10 mouse melanoma cells and the mechanisms of inhibition were elucidated. Inhibition mechanisms were studied by measuring intracellular tyrosinase activity, cell-free and intracellular α-glucosidase enzyme activity, and effects on MITF protein level and cAMP maturation factor. Our results showed that CMC2.24 showed the greatest efficacy as a tyrosinase inhibitor of all the CMCs and was better than PC as well as a popular tyrosinase inhibitor-kojic acid. Both CMC2.24 and CMC2.23 inhibited tyrosinase enzyme activity by a mixed mode of inhibition with a predominant competitive mode. In addition, CMC2.24 as well as CMC2.23 showed a comparable robust efficacy in inhibiting melanogenesis in cultured melanocytes. Furthermore, after removal of CMC2.24 or CMC2.23 from the medium, we could demonstrate a partial recovery of the suppressed intracellular tyrosinase activity in the melanocytes. Our results provide a proof-of-principle for the novel use of the CMCs that shows them to be far superior to the parent compound, curcumin, for skin depigmentation.
Recent developments in quantum cascade lasers (2003)

After a short review on recent developments in Quantum Cascade (QC) lasers, which includes advances in long wavelength lasers, short pulse generation, and applications, we report on efficient intracavity nonlinear light generation in QC-lasers, in particular on optimized second harmonic generation (SHG) in laser active regions with integrated resonant nonlinear optical intersubband transitions.
Nucleophilic Difluoromethylation of Primary Alkyl Halides Using Difluoromethyl Phenyl Sulfone as a Difluoromethyl Anion Equivalent. (2005)

Abstract For Abstract see ChemInform Abstract in Full Text.
Computational studies for a multiple-frequency electron cyclotron resonance ion source (abstract) (1996)

The number density of electrons, the energy (electron temperature), and energy distribution are three of the fundamental properties which govern the performance of electron cyclotron resonance (ECR) ion sources in terms of their capability to produce high charge state ions. The maximum electron energy is affected by several processes including the ability of the plasma to absorb power. In principle, the performances of an ECR ion source can be realized by increasing the physical size of the ECR zone in relation to the total plasma volume. The ECR zones can be increased either in the spatial or frequency domains in any ECR ion source based on B-minimum plasma confinement principles. The former technique requires the design of a carefully tailored magnetic field geometry so that the central region of the plasma volume is a large, uniformly distributed plasma volume which surrounds the axis of symmetry, as proposed in Ref. . Present art forms of the ECR source utilize single frequency microwave power supplies to maintain the plasma discharge; because the magnetic field distribution continually changes in this source design, the ECR zones are relegated to thin ‘‘surfaces’’ which surround the axis of symmetry. As a consequence of the small ECR zone in relation to the total plasma volume, the probability for stochastic heating of the electrons is quite low, thereby compromising the source performance. This handicap can be overcome by use of broadband, multiple frequency microwave power as evidenced by the enhanced performances of the CAPRICE and AECR ion sources when two frequency microwave power was utilized. We have used particle-in-cell codes to simulate the magnetic field distributions in these sources and to demonstrate the advantages of using multiple, discrete frequencies over single frequencies to power conventional ECR ion sources. The electron heating rates are found to scale directly in proportion to the resonant plasma ‘‘volume.’’
Intracellular ATP binding is required to activate the slowly activating K <sup>+</sup> channel I <sub>Ks</sub> (2013)

Gating of ion channels by ligands is fundamental to cellular function, and ATP serves as both an energy source and a signaling molecule that modulates ion channel and transporter functions. The slowly activating K(+) channel I(Ks) in cardiac myocytes is formed by KCNQ1 and KCNE1 subunits that conduct K(+) to repolarize the action potential. Here we show that intracellular ATP activates heterologously coexpressed KCNQ1 and KCNE1 as well as I(Ks) in cardiac myocytes by directly binding to the C terminus of KCNQ1 to allow the pore to open. The channel is most sensitive to ATP near its physiological concentration, and lowering ATP concentration in cardiac myocytes results in I(Ks) reduction and action potential prolongation. Multiple mutations that suppress I(Ks) by decreasing the ATP sensitivity of the channel are associated with the long QT (interval between the Q and T waves in electrocardiogram) syndrome that predisposes afflicted individuals to cardiac arrhythmia and sudden death. A cluster of basic and aromatic residues that may form a unique ATP binding site are identified; ATP activation of the wild-type channel and the effects of the mutations on ATP sensitivity are consistent with an allosteric mechanism. These results demonstrate the activation of an ion channel by intracellular ATP binding, and ATP-dependent gating allows I(Ks) to couple myocyte energy state to its electrophysiology in physiologic and pathologic conditions.
Recent Developments of High-Voltage Light-Triggered Thyristors (2006)

13-kV light-triggered asymmetrical thyristors (LTT)s are studied by numerical simulations and first symmetrically blocking tandem structures-consisting of an asymmetrical thyristor connected in series with a diode-have been fabricated and characterized. It turned out that low-doped field stop layers favor fast turn-on of the subsequent amplifying gate structures. This had to be combined with anode emitter shunting. Our simulations show the very drastic effects of anode shunting, especially on the dv/dt reaction of the anode-side p-n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">- </sup> -n-p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> transistor of the asymmetrical thyristor. Another focus is on the dynamical behavior of the space charge region at optical (and subsequent electrical) amplifying gate triggering, which is different for symmetrical and asymmetrical thyristors. Our simulations indicate that both, intensity and localization of the high-power regions during turn-on are even more favorable in asymmetrical thyristors compared with symmetrical thyristors