gebhart/patrepeval huggingface dataset:
A bandwidth efficient channel estimation method using superimposed training for MIMO-OFDM systems (2008)

In this work an iterative time domain Least Squares (LS) based channel estimation method using superimposed training (ST) for a Multi Input Multi Output(MIMO) Orthogonal Frequency Division Multiplexing (OFDM) system over frequency selective fading channels is proposed. The estimate of the channel is generalized to provide scope for exploiting the coherence time and the coherence bandwidth for an improved performance. The performance of the channel estimator is analyzed in terms of the Mean Square Estimation Error (MSEE) and its impact on the uncoded Bit Error Rate (BER) of the MIMO-OFDM system is studied by considering a two branch transmitter diversity system employing Alamouti space time coding. The selection criterion for the training sequences is proposed by jointly optimizing the MSEE and the BER of the OFDM system. Such sequences, one for each transmitting antenna are required to form an orthogonal set and also ensure a fair distribution of the residual interference due to the training sequence on the data symbols prior to data detection in all the used subcarriers. The effectiveness of the mathematical analysis presented is demonstrated through a comparison with the simulation studies. Also, the proposed scheme is applied to the IEEE 802.16e OFDM standard, its suitability is examined and a case is made with the required design of the sequence.
Resonant periodic gain surface-emitting semiconductor lasers (1989)

A surface-emitting semiconductor laser structure with a vertical cavity, extremely short gain medium length, and enhanced gain at a specific design wavelength is described. The active region consists of a series of quantum wells spaced at one half the wavelength of a particular optical transition in the quantum wells. This special periodicity allows the antinodes of the standing-wave optical field to coincide with the gain elements, enhancing the frequency selectivity, increasing the gain in the vertical direction by a factor of two compared to a uniform medium or a nonresonant multiple quantum well, and substantially reducing amplified spontaneous emission. Optically pumped lasing was achieved in a GaAs/AlGaAs structure grown by molecular-beam epitaxy, with what is believed to be the shortest gain medium (310 nm) ever reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Convenient, Rapid Test for Lead in Blood with Use of Disposable Electrodes (1997)

In recent years concern over the adverse effects of low concentrations of lead on children has increased. In 1991, the CDC reduced the acceptable blood lead concentration from 250 μg/L to 100 μg/L and recommended screening of all American children <6 years old for lead poisoning (1). Graphite furnace atomic absorption spectroscopy is the most common method of measuring lead in blood, but the CDC has encouraged the development of other methods that could be used for mass population screening or near-patient testing. Such methods should be portable, cheap, and easier to use than graphite furnace atomic absorption spectroscopy as recommended by CDC Program Announcement 269, 1992.

The electrochemical technique of stripping voltametry at a mercury electrode has also been used for blood lead analysis. Commercially available instruments based on this method have been used widely but have insufficient accuracy and precision for measuring lead at low concentrations (2). Recently, improvements have been made in the electrochemical measurement of blood lead. Ostapczuk (3) and Jagner et al. (4) obtained good accuracy and precision at low concentrations by potentiometric stripping analysis. They used a mercury-coated graphite electrode that must be cleaned between each analysis, and their testing procedure required stirring of the acidified blood solution.

An approach to stripping analysis that simplifies the testing is the use of disposable electrodes, which can be used once and then thrown away. Microarray electrodes have properties that make them especially suitable for this application. They have high current densities in unstirred solution, have a high signal-to-background ratio, and are not affected …
Synthesis of Prenyl Pyrophosphonates as New Potent Phosphoantigens Inducing Selective Activation of Human Vγ9Vδ2 T Lymphocytes (2004)

Gamma9delta2T cells represent the most abundant population of human blood gammadeltaT lymphocytes. They produce and promote strong cytotoxic activity against many pathogens that are implicated in several human infectious diseases. Their activation requires their exposure to small phosphorus-containing antigens in the family of prenyl pyrophosphates and their related biosynthetic precursors such as isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP), which are naturally occurring metabolites in mycobacteria and several other microbial pathogens. The broad specificity in the recognition of these molecules by the T-lymphocyte population expressing a Vgamma9Vdelta2 cell receptor might facilitate their manipulation by designing small potent synthetic agonist ligands. In this paper, we describe the synthesis and the biological evaluation of new pyrophosphonate compounds as new isosteric analogues of natural prenyl pyrophosphates. Several prenyl and alkenyl pyrophosphonate with different chain lengths and degrees of insaturation (24-28, 48-50, and 64-66) were tested as well as the alkoxymethylpyrophosphonic analogue of IPP (compound 76) as its closest isostere. Several of them appeared to be better activators of Vgamma9Vdelta2 T cell proliferation than IPP. These results open the perspective of a potential use of isoprenoides pyrophosphonates as specific immunoregulatory molecules.
Enzymatic methods for glyco(diversification/randomization) of drugs and small molecules (2011)

Glyco (randomization/diversification) is a term that encompasses strategies to diversify a core drug scaffold via enzymatic glycosylation to provide sets of analogs wherein the sole diversity element is a carbohydrate. This review covers the influence of glycosylation upon various drug properties, the classes of glycosyl-conjugating enzymes amenable to glyco(randomization/diversification) schemes, approaches to the synthesis of required substrates and specific examples of glycorandomized libraries utilizing both wild-type and engineered enzymes.
Quantum arithmetic and numerical analysis using Repeat-Until-Success\n circuits (2014)

We develop a method for approximate synthesis of single--qubit rotations of\nthe form $e^{-i f(\\phi_1,\\ldots,\\phi_k)X}$ that is based on the\nRepeat-Until-Success (RUS) framework for quantum circuit synthesis. We\ndemonstrate how smooth computable functions $f$ can be synthesized from two\nbasic primitives. This synthesis approach constitutes a manifestly quantum form\nof arithmetic that differs greatly from the approaches commonly used in quantum\nalgorithms. The key advantage of our approach is that it requires far fewer\nqubits than existing approaches: as a case in point, we show that using as few\nas $3$ ancilla qubits, one can obtain RUS circuits for approximate\nmultiplication and reciprocals. We also analyze the costs of performing\nmultiplication and inversion on a quantum computer using conventional\napproaches and find that they can require too many qubits to execute on a small\nquantum computer, unlike our approach.\n
Design of High-Aspect-Ratio T-Gates on N-Polar GaN/AlGaN MIS-HEMTs for High $f_{\max}$ (2012)

This letter discusses the design of high-aspect-ratio T-gates on molecular beam epitaxy (MBE)-grown nitrogen-polar (N-polar) GaN/AlGaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) for high power-gain cutoff frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ). A 351-GHz f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> is demonstrated, which is the highest published to date for an N-polar GaN HEMT. Novel 80-nm-long 1.1-m-tall T-gates with a 370-nm-tall stem were used to simultaneously minimize gate resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ) and parasitic gate-drain capacitance (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gd</sub> ). The device on -resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> ) of 0.42 mm was obtained by employing n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> GaN MBE-regrown ohmic contacts and by scaling the lateral separation between regrown source-drain regions to 250 nm. Within the design space explored, this letter experimentally demonstrates that f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> is increased by reducing the gate width and the T-gate top length.
In-Flight Estimation of Center of Gravity Position Using All-Accelerometers (2014)

Changing the position of the Center of Gravity (CoG) for an aerial vehicle is a challenging part in navigation, and control of such vehicles. In this paper, an all-accelerometers-based inertial measurement unit is presented, with a proposed method for on-line estimation of the position of the CoG. The accelerometers' readings are used to find and correct the vehicle's angular velocity and acceleration using an Extended Kalman Filter. Next, the accelerometers' readings along with the estimated angular velocity and acceleration are used in an identification scheme to estimate the position of the CoG and the vehicle's linear acceleration. The estimated position of the CoG and motion measurements can then be used to update the control rules to achieve better trim conditions for the air vehicle.
A Survey of Fault-Injection Methodologies for Soft Error Rate Modeling in Systems-on-Chips (2016)

The development of process technology has increased system performance, but the system failure probability has also significantly increased. It is important to consider the system reliability in addition to the cost, performance, and power consumption. In this paper, we describe the types of faults that occur in a system and where these faults originate. Then, fault-injection techniques, which are used to characterize the fault rate of a system-on-chip (SoC), are investigated to provide a guideline to SoC designers for the realization of resilient SoCs.
Recent Technology Developments in the Production of Grain-Oriented Electrical Steel (2005)

Despite a long history of continuously improved magnetic properties, the further development of grain-oriented electrical steel is still an exciting field for industrial and joint fundamental research. Today, the driving forces for research and development (R&D) are on one hand increasing quality demands, i.e. still lower losses for more energy-efficient transformers and less transformer noise, and on the other hand the pressure to reduce manufacturing costs in order to stay competitive on the market. Evidently in the last years, the latter aspect has become the mainspring for most of the industrial R&D activities. Now nearly all producers are aiming at more compact and less expensive production routes. From the new techniques under development, most advanced in commercial realization is the application of low slab reheating temperatures in the range 1150… 1300°C instead of up to 1400°C in the classical processes. A radical new method is thin slab casting and direct hot rolling used for steels with a system of inherent plus acquired inhibitors, the latter formed by nitriding the cold rolled strip. This method is very promising and far advanced in industrial tests. Another way for process shortening is to cast directly the hot strip from the steel melt by a twin-roll method. In pilot line tests, good cold workability and good magnetic properties have been achieved by optimising chemical composition, casting conditions, and subsequent thermo-mechanical treatments and by working with inherent plus acquired inhibitors. Another theoretical potential for cost and time saving is to replace box annealing for secondary recrystallization by short-time continuous annealing. Such processes are under development, partly using special in-line procedures to realize fast inhibitor creation after primary recrystallization, but are today still far away from commercial realization.
Multiple intents re-ranking (2009)

One of the most fundamental problems in web search is how to re-rank result web pages based on user logs. Most traditional models for re-ranking assume each query has a single intent. That is, they assume all users formulating the same query have similar preferences over the result web pages. It is clear that this is not true for a large portion of queries as different users may have different preferences over the result web pages. Accordingly, a more accurate model should assume that queries have multiple intents. In this paper, we introduce the multiple intents re-ranking problem. This problem captures scenarios in which some user makes a query, and there is no information about its real search intent. In such cases, one would like to re-rank the search results in a way that minimizes the efforts of all users in finding their relevant web pages. More formally, the setting of this problem consists of various types of users, each of which interested in some subset of the search results. Moreover, each user type has a non-negative profile vector. Consider some ordering of the search results. This order sets a position for each search result, and induces a position vector of the results relevant to each user type. The overhead of a user type is the dot product of its profile vector and its induced position vector. The goal is to order the search results as to minimize the average overhead of the users. Our main result is an O(log r)-approximation algorithm for the problem, where r is the maximum number of search results that are relevant to any user type. The algorithm is based on a new technique, which we call harmonic interpolation. In addition, we consider two important special cases. The first case is when the profile vector of each user type is non-increasing. This case is a generalization of the well-known min-sum set cover problem. We extend the techniques of Feige, Lovasz and Tetali (Algorithmica '04), and present an algorithm achieving 4-approximation. The second case is when the profile vector of each user type is non-decreasing. This case generalizes the minimum latency set cover problem, introduced by Hassin and Levin (ESA '05). We devise an LP-based algorithm that attains 2-approximation for it.
ABC–ABC‐Type Directly <i>meso</i>–<i>meso</i> Linked Porphyrin Dimers (2018)

Covalently linked porphyrin oligomers are attractive because of their extended π-conjugated systems. Among various porphyrin oligomers, directly meso-meso linked porphyrin oligomers exhibit unique photophysical properties due to their strong exciton couplings derived from the alternative orthogonal geometry of the porphyrins. Although their structural and electronic properties can be greatly altered by substituents at meso positions, it is still difficult to introduce different substituents at the meso positions. Thus, it is a challenge to develop general synthetic methodologies for functional porphyrin dimers and oligomers with different substituents at the meso positions. Herein, a general synthetic strategy for ABC-ABC-type directly meso-meso linked porphyrin dimers by stepwise functionalization starting from 10,15,20-meso-free 5-substituted porphyrin as building block is established. A meso-ABC-ABC-type meso-meso-linked donor-π-acceptor-type porphyrin dimer was prepared and exhibited the highest power conversion efficiency (7.91 %) ever reported for dye-sensitized solar cells based on dimeric orthogonal donor-π-acceptor-type organic sensitizers. This synthetic strategy will provide useful guidance for the rational design of functional porphyrin dimers and oligomers for diverse applications.
Switching cost minimization in the IEEE 802.16e mobile WiMAX sleep mode operation (2009)

To prolong the battery lifetime, it is important to continue designing a better energy efficient mechanism for different mobile technologies. Most of the existing works on the IEEE 802.16e sleep mode operation focus on the decision making before a mobile station switching to sleep mode state. The correlation of the decision is mainly on when and how to sleep based on the traffic demands. After the mobile station is switched to sleep mode, the deactivation of it mainly depends on new incoming traffic regardless of the actual amount. Truly, frequent switching can increase the energy cost on the mobile station, which can significantly reduce the battery lifetime. To minimize the switching frequency, we propose a novel approach to resolve this issue by making a heuristic decision during the listening interval. With this aim, we propose a real-time heuristic algorithm, WAKSLP_DECISION, to accommodate our target. Three main decision criteria are analyzed and designed, namely the probability of buffer overflow, expected delay violation, and battery lifetime expiry, to achieve our goal. We verify the energy consumption performance with simulation experiments to validate our proposed scheme. The result shows that our scheme performs 25% to 30% better compared with the original standard in terms of energy consumption. We believe this algorithm is practical and implementable without changing the original standard, which can contribute both in the research community and industrial development.
PDE-Constrained Fluorescence Tomography With the Frequency-Domain Equation of Radiative Transfer (2010)

We present the first fluorescence tomography algorithm that is based on a partial differential equation (PDE) constrained approach. PDE methods have been increasingly employed in many numerical applications, as they often lead to faster and more robust solutions of many inverse problems. In particular, we use a sequential quadratic programming (SQP) method, which allows solving the two forward problems in fluorescence tomography (one for the excitation and one for the emission radiances) and one inverse problem (for recovering the spatial distribution of the fluorescent sources) simultaneously by updating both forward and inverse variables in simultaneously at each of iteration of the optimization process. We evaluate the performance of this approach with numerical and experimental data using a transport-theory frequency-domain algorithm as forward model for light propagation in tissue. The results show that the PDE-constrained approach is computationally stable and accelerates the image reconstruction process up to a factor of 15 when compared to commonly employed unconstrained methods.
Process for producing aromatic hydrocarbons of high purity. [from gasoline] (1977)

A process is described for producing aromatic hydrocarbons from gasolines substantially free of mono- and diolefins. It comprises an aromizing step in the presence of a catalyst at a temperature from 400 to 600/sup 0/C under a pressure from 1 to 30 kg/cm/sup 2/ followed with the separation of an aromatic cut and of an alkylaromatic cut and a step of hydrodealkylating said alkylaromatic cut by means of hydrogen recovered from the aromizing step, in the presence of a catalyst, at a temperature from 400 to 650/sup 0/C, under a pressure substantially equal or lower than that of the aromizing step.
An Image Retrieval Relevance Feedback Algorithm Based on the Bayesian Classifier (2002)

The biggest problem in content-based image retrieval (CBIR) is a big gap between high-level semantic contents and low-level features. As an effective solution, relevance feedback has been put on many efforts for the past few years. In this paper, a new relevance feedback approach with progressive learning capability is proposed. It is based on a Bayesian classifier and treats positive and negative feedback examples with different strategies. It can utilize previous users?feedback information to improve its retrieval ability. The experimental results show that this algorithm achieves high accuracy and effectiveness on real-world image collections.
Polyesters from Bio-Aromatics (2015)

Ferulic acid, a naturally occurring hydroxycinnamic acid possessing antioxidant properties, is abundantly available from lignin and lignocellulose. It is the starting material for the synthesis of acetylferulic acid and acetyldihydroferulic acid monomers. These monomers, when copolymerized at various feed ratios, produce copolymers with tunable thermal and physical properties. Some copolymers exhibit thermal properties comparable to commercially available fossil fuel-based packaging plastics—particularly polyethylene terephthalate (PET) and polystyrene (PS). For example, the glass transition temperature can be tuned from 78 °C to 153 °C and increases with increasing ferulic acid content and decreasing dihydroferulic acid content. With promising properties and scalable feedstock availability, copolyesters from substituted hydroxycinnamic acids could prove to be sustainable replacements for a variety of non-renewable and non-degradable commodity plastics.
Quantum Device Development (1988)

Abstract : The results of the first year of research on and development of resonant tunneling transistors are described. A true resonant tunneling transistor consists of a single-well, double-barrier resonant tunneling diode structure to which a third terminal, directly contacting the quantum well, has been added. Two types of resonant tunneling transistors (RTT) are included within the scope of the contract: a unipolar version called the Quantum Excited-State Tunneling Transistor (QuESTT), and a pseudomorphic bipolar version called the Bipolar Quantum Resonant Tunneling Transistor (BiQuaRTT). A lattice-matched version of the BiQuaRTT has been developed. The report describes the development of a theory of resonant tunneling structures and its use to derive device models that have been used in the design of device structures. It also describes the extensive process development required to permit contacting the very thin (50 A) quantum well base layers, and also to isolate the emitter, base, and collector layers. The processes developed have been used to fabricate transistors, and these devices have been characterized electrically. The characterization reveals that a pseudomorphic BiQuaRTT that shows transistor action with a current gain of 5 has been fabricated. Achievement of a functional QuESTT is thought to be imminent. Keywords: Semiconductor devices; Gallium arsenide devices; Heterojunction transistors; Resonant tunneling transistors; Quantum semiconductor devices.
Transformation of <i>Saccharomyces cerevisiae</i> with a cDNA encoding a sterol <i>C</i>‐methyltransferase from <i>Arabidopsis thaliana</i> results in the synthesis of 24‐ethyl sterols (1996)

Using an EST-cDNA probe, a full-length cDNA (411) sequence of 1411 bp was isolated from A. thaliana. This sequence contained features typical of methyltransferases in general and in particular showed 38% identity with ERG6, a S. cerevisiae gene which encodes the zymosterol-C-24-methyltransferase. A yeast vector containing this ORF (4118-pYeDP60) was used to transform a wild type S. cerevisiae which accumulates predominantly ergosterol, a 24-methyl sterol as well as a mutant erg6 null mutant accumulating principally zymosterol, a sterol non-alkylated at C-24. In both cases, several 24-ethyl- and 24-ethylidene sterols were synthetized indicating that the 4118 cDNA encodes a plant sterol C-methyltransferase able to perform two sequential methylations of the sterol side chain.