gebhart/patrepeval huggingface dataset:
NLOS identification and mitigation for localization based on UWB experimental data (2010)

Sensor networks can benefit greatly from location-awareness, since it allows information gathered by the sensors to be tied to their physical locations. Ultra-wide bandwidth (UWB) transmission is a promising technology for location-aware sensor networks, due to its power efficiency, fine delay resolution, and robust operation in harsh environments. However, the presence of walls and other obstacles presents a significant challenge in terms of localization, as they can result in positively biased distance estimates. We have performed an extensive indoor measurement campaign with FCC-compliant UWB radios to quantify the effect of non-line-of-sight (NLOS) propagation. From these channel pulse responses, we extract features that are representative of the propagation conditions. We then develop classification and regression algorithms based on machine learning techniques, which are capable of: (i) assessing whether a signal was transmitted in LOS or NLOS conditions; and (ii) reducing ranging error caused by NLOS conditions. We evaluate the resulting performance through Monte Carlo simulations and compare with existing techniques. In contrast to common probabilistic approaches that require statistical models of the features, the proposed optimization-based approach is more robust against modeling errors.
Role of human T-cell leukemia virus type 1 X region proteins in immortalization of primary human lymphocytes in culture (1992)

Human T-cell leukemia virus type 1 (HTLV-1) immortalizes human CD4+ T lymphocytes in culture. Previous studies show that in the context of a herpesvirus saimiri vector, the sequence of the X region at the 3' end of the HTLV-1 genome is also capable of immortalizing CD4+ lymphocytes in the absence of HTLV-1 structural proteins. The X region of HTLV-1 encodes two trans-acting viral proteins, the 42-kDa Tax protein and the 27-kDa Rex protein. Infection of human cord blood cells with herpesvirus saimiri recombinants which contain HTLV-1 X region sequences defective for expression of tax, rex, or both tax and rex demonstrates that tax function is necessary and sufficient for immortalization of primary human CD4+ cord blood lymphocytes in culture in the context of the herpesvirus saimiri vector.
A new cascaded multilevel H-bridge drive (2002)

In this paper, a general structure for cascaded power converters is presented in which any number of H-bridge cells having any number of voltage levels are series connected to form an inverter phase leg. Equations are introduced for determining an optimal voltage ratio of DC voltages for the H-bridge cells which will maximize the number of voltage levels obtainable resulting in high power quality. Special cases of the generalized inverter are presented including novel 11-level and 15-level inverters. Laboratory measurements demonstrate the proposed inverter performance.
An Improved Method of Automated Nonparametric Content Analysis for Social Science (2022)

Abstract Some scholars build models to classify documents into chosen categories. Others, especially social scientists who tend to focus on population characteristics, instead usually estimate the proportion of documents in each category—using either parametric “classify-and-count” methods or “direct” nonparametric estimation of proportions without individual classification. Unfortunately, classify-and-count methods can be highly model-dependent or generate more bias in the proportions even as the percent of documents correctly classified increases. Direct estimation avoids these problems, but can suffer when the meaning of language changes between training and test sets or is too similar across categories. We develop an improved direct estimation approach without these issues by including and optimizing continuous text features, along with a form of matching adapted from the causal inference literature. Our approach substantially improves performance in a diverse collection of 73 datasets. We also offer easy-to-use software that implements all ideas discussed herein.
A new high frequency inductor loss measurement method (2011)

Recently, the integrated point-of-load (POL) converters are pushing to high frequency in order to reduce the converter volume. The inductor loss accounts for a significant part of the total converter loss. So accurate measurement of the inductor loss is important for magnetic design. The conventional methods have limitations when measuring high frequency inductor loss under different excitation conditions. In this paper, a new method utilizing reactive cancellation concept overcomes the shortcoming of conventional methods, and increases the accuracy. With appropriate excitation, this method can measure the inductor loss under practical AC waveform and DC current working conditions.
Blind source separation based on multi-user kurtosis criteria (2002)

A novel technique for the blind source separation (BSS) of mutually independent and identically distributed i.i.d. discrete-time sequences is presented. The observed signals are assumed mixed through a narrow-band (memoryless) multiple-input-multiple-output (MIMO) noisy channel and are then processed by a linear MIMO receiver, whose outputs should ideally match the transmitted signals. In the proposed approach (called the multi-user kurtosis (MUK) algorithm), the linear receiver's matrix setting is computed adaptively based on the optimization of a constrained statistical criterion that involves only second and fourth order statistics of the receiver's output. At each iteration, the algorithm combines a stochastic gradient adaptation with a Gram-Shmidt orthogonalization that enforces its criterion's constraints. The analysis of its stationary points, reveals that it is globally convergent to a zero forcing -ZF (or decorrelating) solution, both in the absence of noise and in the presence of spatio-temporally white additive Gaussian noise.
Correction: Corrigendum: Novel n-3 Immunoresolvents: Structures and Actions (2014)

Resolution of inflammation is now held to be an active process where autacoids promote homeostasis. Using functional-metabololipidomics and in vivo systems, herein we report that endogenous n-3 docosapentaenoic (DPA) acid is converted during inflammation-resolution in mice and by human leukocytes to novel n-3 products congenerous to D-series resolvins (Rv), protectins (PD) and maresins (MaR), termed specialized pro-resolving mediators (SPM). The new n-3 DPA structures include 7,8,17-trihydroxy-9,11,13,15E,19Z-docosapentaenoic acid (RvD1n-3 DPA), 7,14-dihydroxy-8,10,12,16Z,19Z-docosapentaenoic acid (MaR1n-3 DPA) and related bioactive products. Each n-3 DPA-SPM displayed protective actions from second organ injury and reduced systemic inflammation in ischemia-reperfusion. The n-3 DPA-SPM, including RvD1n-3 DPA and MaR1n-3 DPA, each exerted potent leukocyte directed actions in vivo. With human leukocytes each n-3 DPA-SPM reduced neutrophil chemotaxis, adhesion and enhanced macrophage phagocytosis. Together, these findings demonstrate that n-3 DPA is converted to novel immunoresolvents with actions comparable to resolvins and are likely produced in humans when n-3 DPA is elevated.
Cross-talk considerations for angular and phase-encoded multiplexing in volume holography (1994)

We compare the characteristics of cross talk for angular multiplexing and several phase-encoded multiplexing strategies for volume holography. We discuss the implications of these characteristics for holographic data storage and compare noise arising from cross talk with noise arising from scattering that is due to inhomogeneities within a holographic medium.
Micro/Nanoparticle Delivery Systems for Ocular Diseases (2019)

<i>Micro- (MPs) and nanoparticles (NPs) have been recently studied for their application in ophthalmic drug delivery. These drug delivery systems are able to circumvent the ocular barriers that currently limit the efficacy of conventional treatments, as well as provide a more sustained release of drug, reducing the frequency of administration and increasing patient compliance. This review summarizes the recent trends in ophthalmic research from conventional treatment to the utilization of MPs and NPs as drug carriers.</i>
Centro-symmetric technique for measuring shear modulus, viscosity, and surface tension of spread monolayers (1983)

We have constructed an apparatus which enables one to measure, simultaneously, the shear modulus, the viscosity, and the surface pressure of a monomolecular film on water under a hydrostatic compression. It is particularly suitable for measurements of the static shear modulus of insoluble monolayers. A capillary wave generator/detector system was also incorporated to determine the surface pressure. The trough is a Teflon cup 12.7 cm (5.4 in.) in inner diameter with sloping interior sides. As the cup is raised, while maintaining the water elevation fixed, the film is uniformly compressed. A rotor suspended at the center from a fine torsion fiber is used to measure the mechanical properties (surface viscosity and/or surface shear modulus). To measure the quasistatic shear properties, the cup is rotated through a small angle and the residual deflection of the rotor determined. Dynamic shear response is probed by studying transient torsional oscillations following a sudden angular displacement of the torsion fiber. There are no barrier seals and circular symmetry is maintained at all times. The apparatus has a resolution of 5×10−4 surface poise of shear viscosity and 1×10−4 dyn/cm of static shear modulus.
Echo Cancellation in Speech and Data Transmission (1984)

This tutorial paper reviews echo cancellation techniques as applied to both voice and data transmission applications. The echo control problem in telephone voice transmission is described, and the several measures taken to counteract echo are outlined. The problem of full-duplex data transmission over two-wire lines is described, with application to both digital subscriber loop and voiceband data transmission. The unique characteristics of each of these applications, more advanced methods recently proposed, and approaches to implementation are described.
PTP4A1 promotes TGFβ signaling and fibrosis in systemic sclerosis (2017)

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of skin and internal organs. Protein tyrosine phosphatases have received little attention in the study of SSc or fibrosis. Here, we show that the tyrosine phosphatase PTP4A1 is highly expressed in fibroblasts from patients with SSc. PTP4A1 and its close homolog PTP4A2 are critical promoters of TGFβ signaling in primary dermal fibroblasts and of bleomycin-induced fibrosis in vivo. PTP4A1 promotes TGFβ signaling in human fibroblasts through enhancement of ERK activity, which stimulates SMAD3 expression and nuclear translocation. Upstream from ERK, we show that PTP4A1 directly interacts with SRC and inhibits SRC basal activation independently of its phosphatase activity. Unexpectedly, PTP4A2 minimally interacts with SRC and does not promote the SRC-ERK-SMAD3 pathway. Thus, in addition to defining PTP4A1 as a molecule of interest for TGFβ-dependent fibrosis, our study provides information regarding the functional specificity of different members of the PTP4A subclass of phosphatases.
Silicon micromachined ultrasonic transducers (2002)

This paper reviews ultrasonic transducers that are made by silicon micromachining (MUTs). Transducers for both air-borne and immersion applications are made from parallel plate capacitors whose dimensions are controlled through traditional integrated circuit manufacturing methods. Typical dimensions of the capacitors are: gap <1 micron (vacuum or air), membrane thickness=1 micron (silicon nitride or poly-silicon), and diameter=50 microns. A large number of small elements are connected in parallel to make a transducer. Transducers for air borne ultrasound applications have been operated in the frequency range of 0.1-11 MHz, while immersion transducers have been operated in the frequency range of 1-20 MHz. A theoretical model for the transducers will be presented. The model is used to highlight the important parameters in the design of both airborne and immersion transducers. Theory is used to compare the receive sensitivity, the transmit power capability, and the bandwidth of the MUTs to piezoelectric transducers. We will show that MUTs are at least as good if not better performing than piezoelectric transducers. Examples of single element transducers, linear array transducers, and two dimensional arrays of transducers will be presented. The agreement between the theory and experimental measurements will be presented and will prove the validity of the model. In summary, we will present a capacitive micromachined transducer technology that is competitive to the piezoelectric technology and that carries the advantage of electronic integration and batch processing using silicon fabrication practices.
Inhibition of brain tumor growth by intravenous poly(β- <scp>l</scp> -malic acid) nanobioconjugate with pH-dependent drug release (2010)

Effective treatment of brain neurological disorders such as Alzheimer's disease, multiple sclerosis, or tumors should be possible with drug delivery through blood-brain barrier (BBB) or blood-brain tumor barrier (BTB) and targeting specific types of brain cells with drug release into the cell cytoplasm. A polymeric nanobioconjugate drug based on biodegradable, nontoxic, and nonimmunogenic polymalic acid as a universal delivery nanoplatform was used for design and synthesis of nanomedicine drug for i.v. treatment of brain tumors. The polymeric drug passes through the BTB and tumor cell membrane using tandem monoclonal antibodies targeting the BTB and tumor cells. The next step for polymeric drug action was inhibition of tumor angiogenesis by specifically blocking the synthesis of a tumor neovascular trimer protein, laminin-411, by attached antisense oligonucleotides (AONs). The AONs were released into the target cell cytoplasm via pH-activated trileucine, an endosomal escape moiety. Drug delivery to the brain tumor and the release mechanism were both studied for this nanobiopolymer. Introduction of a trileucine endosome escape unit resulted in significantly increased AON delivery to tumor cells, inhibition of laminin-411 synthesis in vitro and in vivo, specific accumulation in brain tumors, and suppression of intracranial glioma growth compared with pH-independent leucine ester. The availability of a systemically active polymeric drug delivery system that passes through the BTB, targets tumor cells, and inhibits glioma growth gives hope for a successful strategy of glioma treatment. This delivery system with drug release into the brain-specific cell type could be useful for treatment of various brain pathologies.
Robotic radiosurgery with noncylindrical collimators (1997)

In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of fixed cross section. The radiation source can be moved only along simple, standardized paths. A new radiosurgical system based on a six-degree-of-freedom robotic arm has been developed to overcome limitations of conventional systems. We address the following question: Can dose distributions generated by robotic radiosurgery be improved by using noncylindrical radiation beams? This includes static noncylindrical collimators and collimators of adaptable cross section. Geometric methods for planning the shape of the beam in addition to planning beam motion are developed. Design criteria considered in this context are treatment time, radiation penumbra, and transparency of interactive treatment planning. An experimental evaluation compares distributions generated with our new radiosurgical system using cylindrical beams to distributions generated with beams of adaptable, noncylindrical shapes.
Advanced demodulation technique for the extraction of tissue optical properties and structural orientation contrast in the spatial frequency domain (2014)

We have developed a method for extracting spatial frequency information content from biological tissue, which is used to calculate tissue optical properties and determine tissue structural orientation. This demodulation method employs a two-dimensional Hilbert transform using a spiral phase function in Fourier space. The approach presented here allows for the determination of tissue optical properties using a single frame of data for each modulation frequency, increasing imaging speed by two to threefold versus conventional, three-phase spatial frequency domain imaging (SFDI). This new single-phase Hilbert transform approach recovers optical property and scattering orientation index values within 1% and 10% of three-phase SFDI, respectively. These results suggest that, using the Hilbert demodulation technique, SFDI data acquisition speed can be increased significantly while preserving data quality, which will help us move forward toward the implementation of a real-time SFDI platform.
Initiating and Monitoring the Evolution of Single Electrons Within Atom-Defined Structures (2018)

Using a noncontact atomic force microscope, we track and manipulate the position of single electrons confined to atomic structures engineered from silicon dangling bonds on the hydrogen terminated silicon surface. An attractive tip surface interaction mechanically manipulates the equilibrium position of a surface silicon atom, causing rehybridization that stabilizes a negative charge at the dangling bond. This is applied to controllably switch the charge state of individual dangling bonds. Because this mechanism is based on short range interactions and can be performed without applied bias voltage, we maintain both site-specific selectivity and single-electron control. We extract the short range forces involved with this mechanism by subtracting the long range forces acquired on a dimer vacancy site. As a result of relaxation of the silicon lattice to accommodate negatively charged dangling bonds, we observe charge configurations of dangling bond structures that remain stable for many seconds at 4.5 K. Subsequently, we use charge manipulation to directly prepare the ground state and metastable charge configurations of dangling bond structures composed of up to six atoms.
Adaptive Delta-Sigma Modulation for Enhanced Input Dynamic Range (2006)

An adaptive delta-sigma modulator of 1st order with one-bit quantization is presented. Adaptation is instantaneous and based on an exponential law. The feedback signal is a multibit discrete-level signal generated by a digital-to-analog converter (DAC). Compared to a nonadaptive delta-sigma modulator of 1st order, the input dynamic range is significantly enhanced. The gain in dynamic range is 6 dB per bit defining the feedback amplitude. The influence of nonideal DAC performance is discussed. It is demonstrated that an implementation of the system is realistic with standard CMOS technology. To relax the requirements to the one-bit quantizer, the quantizer input signal is amplified adaptively (Q-Switching).
Endpoint Identification Using System Logs (2009)

Typical logging of public Internet activity involves recording only the source IP address associated with a transaction or access. Unfortunately this is usually insufficient to identify a unique endpoint associated with the activity, mainly due to the common existence of one or more NAT gateways between the originating network and the Internet and the lack of specific logging at the originating end. Here we address the information needed to solve this problem, where it needs to come from, and various scenarios for how it can be managed. Specifically, in order to uniquely identify a specific endpoint, three related pieces of information need to be recorded: 1. the MAC address associated with the local IP address at the originating network (known by a DHCP daemon); 2. the association between the local IP address and port numbers at each NAT gateway (known by a NAT daemon); and 3. the source port number of the public access (known by the remote server). A related problem of MAC address validation, allowing the association of a specific hardware device with a MAC address in use, is discussed as well.
Reversible Indicators For Alkali Metal Ion Optical Sensors (1987)

An indicator system that responds reversibly to alkali metal ion concentrations has been developed. The components of the indicator system include the Cu(II) complex of aqueous polyethylenimine, an anionic fluorophor, and a neutral ionophore immobilized by adsorption on silica particles. In the absence of alkali metal ion, the anionic fluorophor binds to the Cu(II)-polyethylenimine complex where the presence of the paramagnetic Cu(II) ion causes quenching. When an alkali metal ion is present, it complexes with the ionophore forming a hydrophobic cation which binds to some of the anionic fluorophor rendering it fluorescent. The fluorescence of the indicator can be measured through optical fiber resulting in a reversible sensor for alkali metal ions.
Mean curvature mapping for detection of corneal shape abnormality (2005)

Corneal topography is used to measure the anterior surface of the cornea. It is conventionally represented as radial slope, radial curvature, and elevation. In this paper, we introduce the application of mean curvature mapping as an alternative representation of the corneal topography. The purpose is to improve the detection of keratoconus and other diseases characterized by local increase in corneal curvature. Both simulated keratoconic cornea and real keratoconus data exported from the corneal topography system were analyzed. Four representations of corneal topography were generated and compared. It was found that mean curvature mapping provided the most precise cone location in simulated keratoconus. In both actual and simulated keratoconus cases, the appearance of the cone-like distortion is more consistent on mean curvature maps. Mean curvature mapping may improve the detection and localization of corneal shape abnormalities.
Potent vasopressin antagonists lacking the proline residue at position 7 (1986)

As part of a program to design potent antidiuretic vasopressin antagonists and to define the minimum effective pharmacophore requirements for vasopressin (VP) antagonist activity, we studied the importance of the C-terminal tripeptide of a previously reported peptide antagonist of arginine-vasopressin (AVP,1). The proline residue at position 7 in AVP is proposed to impart a conformational constraint to the peptide backbone that is essential for V2-receptor agonist activity. Since the structure-activity relationships for VP agonists and antagonists are different, we investigated the effect of proline on antagonist activity, by synthesizing analogue 3 lacking this residue. This analogue was found to retain a high degree of antidiuretic antagonist activity. Since deletion of the Gly residue at position 9 of the antagonist did not adversely affect VP antagonist potency, several vasopressin antagonist analogues (4-7 and 9) that lacked both the Pro and Gly residues were also studied. These, too, were found to block vasopressin V2-receptor activity. Our results indicate that neither the proline nor glycine residues are essential for antagonism of the V2 receptor.
Rendering from compressed high dynamic range textures on programmable graphics hardware (2007)

High dynamic range (HDR) images are increasingly employed in games and interactive applications for accurate rendering and illumination. One disadvantage of HDR images is their large data size; unfortunately, even though solutions have been proposed for future hardware, commodity graphics hardware today does not provide any native compression for HDR textures.