cssi/SciSciGPT-SciSciNet huggingface dataset:
Decreased atmospheric sulfur deposition across the southeastern U.S.: When will watersheds release stored sulfate?

Emissions of sulfur dioxide (SO2) to the atmosphere lead to atmospheric deposition of sulfate (SO42–), which is the dominant strong acid anion causing acidification of surface waters and soils in the eastern United States. Since passage of the Clean Air Act and its Amendments, atmospheric deposition of SO2 in this region has declined by over 80%, but few corresponding decreases in streamwater SO42– concentrations have been observed in unglaciated watersheds. We calculated SO42– mass balances for 27 forested, unglaciated watersheds from Pennsylvania to Georgia, by using total atmospheric deposition (wet plus dry) as input. Many of these watersheds still retain SO42–, unlike their counterparts in the northeastern U.S. and southern Canada. Our analysis showed that many of these watersheds should convert from retaining to releasing SO42– over the next two decades. The specific years when the watersheds crossover from retaining to releasing SO42– correspond to a general geographical pattern of later net waters...
The photooxidation of allyl chloride

The photooxidation of allyl chloride was studied by irradiation either in 100-L Teflon bags or in a 22.7-m3 Teflon smog chamber in the presence of added NOx. In the absence of added hydrocarbons, the reaction involves a Cl atom chain, which leads to a highly reactive system. A reaction mechanism is presented to account for the following photooxidation products: chloroacetaldehyde, formaldehyde, 1,3-dichloroacetone, 3-chloroacrolein, acrolein, glyoxal, chloroperoxyacetyl nitrate, and peroxypropenyl nitrate. The rate constant for OH reaction with allyl chloride at 298 K was measured by a relative rate method under conditions where the Cl atom chain length was small and was found to be kOH = 1.7 × 10−11 cm3 molecule−1 s−1. The rate constant for O3 reaction with allylchloride at 298 K was found to be kO3 = 1.5 × 10−18 cm3 molecule−1 s−1.
Does Short-Term Debt Increase Vulnerability to Crisis? Evidence from the East Asian Financial Crisis☆

Abstract Does short-term debt increase vulnerability to financial crisis, or does short-term debt reflect – rather than cause – the incipient crisis? We study the role that short-term debt played in the collapse of the East Asian financial sector in 1997–1998. We alleviate concerns about the endogeneity of short-term debt by using long-term debt obligations that matured during the crisis. We find that debt obligations issued at least three years before the crisis had a negative, albeit sometimes insignificant, effect on the probability of failure. Our results are consistent with the view that short-term debt reflects, rather than causes, distress in financial institutions.
EXTENDED HOT HALOS AROUND ISOLATED GALAXIES OBSERVED IN THE ROSAT ALL-SKY SURVEY

We place general constraints on the luminosity and mass of hot X-ray-emitting gas residing in extended hot halos around nearby massive galaxies. We examine stacked images of 2165 galaxies from the 2MASS Isolated Galaxy Catalog as well as subsets of this sample based on galaxy morphology and K-band luminosity. We detect X-ray emission at high confidence (ranging up to nearly 10σ) for each subsample of galaxies. The average LX within 50 kpc is 1.0 ± 0.1 (statistical) ±0.2 (systematic) × 1040 erg s–1, although the early-type galaxies are more than twice as luminous as the late-type galaxies. Using a spatial analysis, we also find evidence for extended emission around five out of seven subsamples (the full sample, the luminous galaxies, early-type galaxies, luminous late-type galaxies, and luminous early-type galaxies) at 92.7%, 99.3%, 89.3%, 98.7%, and 92.1% confidence, respectively. Several additional lines of evidence also support this conclusion and suggest that about 1/2 of the total emission is extended, and about 1/3 of the extended emission comes from hot gas. For the sample of luminous galaxies, which has the strongest evidence for extended emission, the average hot gas mass is 4 × 109 M ☉ within 50 kpc and the implied accretion rate is 0.4 M ☉ yr–1.
Dilysine motifs in exon 2b of SMN protein mediate binding to the COPI vesicle protein α-COP and neurite outgrowth in a cell culture model of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder that stems from low levels of survival of motor neuron (SMN) protein. The processes that cause motor neurons and muscle cells to become dysfunctional are incompletely understood. We are interested in neuromuscular homeostasis and the stresses put upon that system by loss of SMN. We recently reported that α-COP, a member of the coatomer complex of coat protein I (COPI) vesicles, is an SMN-binding partner, implicating this protein complex in normal SMN function. To investigate the functional significance of the interaction between α-COP and SMN, we constructed an inducible NSC-34 cell culture system to model the consequences of SMN depletion and find that depletion of SMN protein results in shortened neurites. Heterologous expression of human SMN, and interestingly over-expression of α-COP, restores normal neurite length and morphology. Mutagenesis of the canonical COPI dilysine motifs in exon 2b results in failure to bind to α-COP and abrogates the ability of human SMN to restore neurite outgrowth in SMN-depleted motor neuron-like NSC-34 cells. We conclude that the interaction between SMN and α-COP serves an important function in the growth and maintenance of motor neuron processes and may play a significant role in the pathogenesis of SMA.
Refinement of the Sphere-Packing Bound: Asymmetric Channels

We provide a refinement of the sphere-packing bound for constant composition codes over asymmetric discrete memoryless channels that improves the subexponential factor in front of the exponent. The order of our subexponential factor is Ω(N-0.5(1+e+ρR*)) for any ϵ > 0, where ρR* is the left derivative of the sphere-packing exponent at rate R and N is the blocklength.
Single-Photon Sensitivity of Lamprey Rods with Cone-like Outer Segments

Most vertebrates have a duplex retina containing rods for dim light vision and cones for bright lights and color detection. Photoreceptors like cones are present in many invertebrate phyla as well as in chordata, and rods evolved from cones, but the sequence of events is not well understood. Since duplex retinas are present in both agnatha and gnathostomata, which diverged more than 400 million years ago, some properties of ancestral rods may be inferred from a comparison of cells in these two groups. Lamprey have two kinds of photoreceptors, called "short" and "long", which seem to be rods and cones; however, the outer segments of both have an identical cone-like morphology of stacks of lamellae without a continuous surrounding plasma membrane. This observation and other aspects of the cellular and molecular biology of the photoreceptors have convinced several investigators that "the features of 'true' rod transduction in jawed vertebrates, which permit the reliable detection of single photons of light, evolved after the separation of gnathostomes from lampreys". To test this hypothesis, we recorded from photoreceptors of the sea lamprey Petromyzon marinus and show that their rods have a single-photon sensitivity similar to that of rods in other vertebrates. Thus, photoreceptors with many of the features of rods emerged before the split between agnatha and gnathostomata, and a rod-like outer segment with cytosolic disks surrounded by a plasma membrane is not necessary for high-sensitivity visual detection.
Functionalization of saturated fluorocarbons with and without light

Photochemical transformation of saturated fluorocarbons into tetrabutylammonium enolates has been improved, and a method employing ketyls as reductants has been developed that accomplishes the same chemistry without light. Enolates have been isolated as enol methyl ethers, from which they can be efficiently regenerated with tetrabutylammonium iodide. In other cases, enolates have been isolated as the corresponding ketone or stable enol. Fluorocarbon LUMO energies correlate with their reactivity and serve as a guide to the choice of ketyl. Use of this chemistry for fluoropolymer surface modification is discussed.
In Situ Synthesis of Silicon Carbide Whiskers from Silicon Nitride Powders

Silicon carbide whiskers were synthesized in situ by direct carbothermal reduction of silicon nitride with graphite in an argon atmosphere. Phase evolution study reveals that the formation of β-SiC was initiated at 1400° to 1450°C; above 1650°C silicon was formed when carbon was deficient. Nevertheless, Si3N4 could be completely converted to SiC with molar ratio Si3N4:C = 1:3 at 1650°C. The morphology of the SiC whiskers is needlelike, with lengths and diameters changing with temperature. SiC fibers were produced on the surface of the sample fired at 1550°C with an average diameter of 0.3 μm. No catalyst was used in the syntheses, which minimizes the amount of impurities in the final products. A reaction mechanism involving the decomposition of silicon nitride has been proposed.
Risk Aversion in International Relations Theory

When international relations writers use the idea of risk aversion, they either leave it undefined or cite the economics conception, that the decision-maker has a concave utility function for the goal. However, in the international context the goal is typically not money or any other objectively measurable quantity, and in this case the concept of concavity is meaningless. This article gives two definitions of risk aversion that are “non-metric” in the sense that they do not require such a quantity. The first, comparative risk aversion , specifies the relative degree of aversion but does not specify a zero point. The second concept, multiattribute risk aversion , does the reverse, separating risk-averters from risk-seekers in an absolute sense without making comparisons within each group. The arguments imply significant revisions of work on historical case studies using prospect theory and Fearon's categorization of rationalist explanations for war. It indicates that countries might be unable to negotiate their way out of a war because certain kinds of disputes, especially those over symbols or religious places, often generate risk-seeking behavior.
Kinetic simulation of a time-dependent two-dimensional plasma

Abstract The distribution function of ions is calculated in a two-dimensional plasma with a rapidly expanding sheath, self-consistently with the electrostatic potential, φ . The numerical procedure consists of a direct solution of an integral form of the kinetic equation. This solution relies on the use of a simple form for the Green's function which describes the time-evolution of the distribution, which has previously been used in one spatial dimension and is here extended to two dimensions. The electron density n 0 is assumed to be described by the Boltzmann relation. n 0 n 0 exp( cφ/κT 0 ), allowing Poisson's equation to be solved for φ self-consistently with the ion density. This procedure is applied to describe the plasma surrounding a "target" to which is rapidly applied a large negative potential, as occurs in plasma source ion implantation (PSII). The ion distribution striking the target is calculated to allow determination of the dose and depth profile.
Pipelined two step iterative matching algorithms for CIOQ crossbar switches

Traditional iterative matching algorithms for VOQ switches need three steps, i.e., request, grant and accept. By incorporating arbitration into the request step, two step iterative matching can be achieved. This enables simpler implementation and shorter scheduling time, while maintaining almost identical performance. As an example of the two step iterative matching algorithms, in this paper we present two step parallel iterative matching (PIM2), and theoretically prove that its average convergence iterations are less than In N + e/(e - 1) for an N X N switch. Furthermore, two step iterative matching algorithms can be efficiently pipelined on CIOQ switches so that two matchings can be obtained in each time slot. We propose a scheme called second of line (SOL) matching to provide two independent virtual switches, with which the pipelining can be achieved without additional scheduling time and arbitration hardware. More importantly, the pipelined algorithms are theoretically guaranteed to achieve 100% throughput for any admissible traffic. Extensive simulations are conducted to show that our analytical result on the average convergence iterations In N + e/(e - 1) is more accurate than the classical result log2 N + 4/3, and to test the performance of different pipelined algorithms on CIOQ switches.
Prediction and Prevention of Child Abuse and Neglect

A high-risk population was successfully identified by the use of perinatal screening procedures. These children encountered significantly different parenting practices than the low-risk "control" group. There were also significant differences between "High-Risk" and "Low-Risk" families on issues concerning social adjustment and mother/infant attachment. Five children in a "High-Risk Nonintervene" group required hospitalization for serious injuries thought to be secondary to abnormal parenting practices. There were no such hospitalizations in either a High Risk Intervene group or a Low Risk group. Labordelivery observations, and postpartum interviews and observations provided the most accurate predictive information; prenatal interviews and questionnaires did not add significantly. Perinatal assessment and simple intervention with families at high risk for abnormal parenting practices significantly improves the infants' chances for escaping serious hospitalized physical injury. Language: en
4G Mobile Communication Systems: Turns, Trends and Transition

Recent activity in 4G (fourth generation) mobile communication systems has steeped the race in its implementation at the earliest. 4G wireless being an upcoming standard witnesses burgeoning interest amongst researchers and vendor. It is being designed to allow seamless integration and communication between wireless devices across diverse wireless standards as well as broadband networks wirelessly. Access to different radio technologies is facilitated due to IP-based-4G mobile communication system connecting the user. This paper attempts to make an assessment in development, transition, and roadmap for fourth generation mobile communication system with a perspective of wireless convergence domain and future research issues.
Simulated multiply-scattered lidar returns from nonspherical particles

Presents an investigation of the characteristics of multiply-scattered lidar returns from homogeneous layers of monodispersed nonspherical particles. A Monte Carlo procedure has been employed to simulate lidar measurements. Total detected power as well as depolarization of the detected signal have been calculated for a variety of particle deformations and orientations, fields of view (FOVs) of the receiver and optical thicknesses of the medium. It has been found that in certain cases multiply-scattered photons cause a decrease in the depolarization of the received light. The results have been checked, for double scattering, by comparing them with the outcome of analytical calculations.
DNA methylation and histone modifications of Wnt genes by genistein during colon cancer development

This study aims to elucidate the epigenetic mechanisms by which genistein (GEN) maintains a normal level of WNT genes during colon cancer development. We have reported that soy protein isolate (SPI) and GEN repressed WNT signaling, correlating with the reduction of pre-neoplastic lesions in rat colon. We hypothesized that SPI and GEN induced epigenetic modifications on Sfrp2, Sfrp5 and Wnt5a genes, suppressing their gene expression induced by azoxymethane (AOM), a chemical carcinogen, to the similar level as that of pre-AOM period. We identified that in the post-AOM period, histone H3 acetylation (H3Ac) was downregulated by SPI and GEN at the promoter region of Sfrp2, Sfrp5 and Wnt5a, which paralleled with the reduced binding of RNA polymerase II. Nuclear level of histone deacetylase 3 was enhanced by SPI and GEN. The diets suppressed the trimethylation of histone H3 Lysine 9 (H3K9Me3) and the phosphorylation of histone H3 Serine 10 (H3S10P). Methylation of the specific region of Sfrp2, Sfrp5 and Wnt5a genes was increased by SPI and GEN, which was inversely correlated with the reduction of gene expression. Bisulfite sequencing further confirmed that dietary GEN induced DNA methylation at CpG island of the promoter region of Sfrp5. Importantly, this region includes a fragment that had decreased H3Ac. Here, we present a potential epigenetic mechanism by which dietary GEN controls the responses of WNT genes during carcinogen induction, which involves DNA methylation, histone modifications and their interactions at the regulatory region of gene.
Using mixed methods in monitoring and evaluation : experiences from international development

This paper reviews the main challenges and opportunities for incorporating mixed method approaches into research and evaluation on the effectiveness and impacts of international development. It draws on the authors’ experience over several decades working in both academia and with a wide range of multilateral and bilateral development agencies, non-profit organisations and developing country governments on the evaluation of the effectiveness and impacts of development interventions. Development research is informed by current research trends in Northern countries, but it is often conducted within very distinct economic, political, cultural and organisational contexts. While certainly not unique to the international context, many development evaluations are subject to a range of budget, time, data, political and organisational constraints that tend to be more severe than those faced by researchers working in industrialised nations. Moreover, due to the more limited opportunities to conduct research in developing countries, individual studies or evaluations are often required to address a broader set of questions. So while a researcher in the US may be able to focus exclusively on a rigorous summative evaluation designed to address a limited range of questions on quantitative impacts, the same researcher evaluating a major development intervention in Latin America, Africa or Asia may be asked to address a wider range of summative and formative questions. We argue that the demand for multi-purpose evaluations in developing countries opens up opportunities for a broader application of mixed method approaches than is usually the case in ‘mainstream’ mixed method research. We hope that this paper will help readers to understand the unique challenges, and also the great opportunities, for strengthening the use of mixed methods in the international development context.
Iron-catalyzed intermolecular [2+2] cycloadditions of unactivated alkenes

Cycloadditions, such as the [4+2] Diels-Alder reaction to form six-membered rings, are among the most powerful and widely used methods in synthetic chemistry. The analogous [2+2] alkene cycloaddition to synthesize cyclobutanes is kinetically accessible by photochemical methods, but the substrate scope and functional group tolerance are limited. Here, we report iron-catalyzed intermolecular [2+2] cycloaddition of unactivated alkenes and cross cycloaddition of alkenes and dienes as regio- and stereoselective routes to cyclobutanes. Through rational ligand design, development of this base metal-catalyzed method expands the chemical space accessible from abundant hydrocarbon feedstocks.
Iron(II)-catalyzed trifluoromethylation of potassium vinyltrifluoroborates.

An iron(II)-catalyzed trifluoromethylation of potassium vinyltrifluoroborates has been developed. The reactions proceed under mild conditions and provide E/Z selectivities of > 95:5 for 2-aryl and -heteroarylvinyl substrates. Experimental observations suggest that the reaction does not proceed through a transmetallation of the RBF3K to the iron catalyst.
STOCHASTIC ACCELERATION OF ELECTRONS AND PROTONS. I. ACCELERATION BY PARALLEL-PROPAGATING WAVES

Stochastic acceleration of electrons and protons by waves propagating parallel to the large-scale magnetic fields of magnetized plasmas is studied with emphasis on the feasibility of accelerating particles from a thermal background to relativistic energies and with the aim of determining the relative acceleration of the two species in one source. In general, the stochastic acceleration by these waves results in two distinct components in the particle distributions, a quasi-thermal and a hard nonthermal, with the nonthermal one being more prominent in hotter plasmas and/or with higher level turbulence. This can explain many of the observed features of solar flares. Regarding the proton-to-electron ratio, we find that in a pure hydrogen plasma the dominance of the wave-proton interaction by the resonant Alfven mode reduces the acceleration rate of protons in the intermediate energy range significantly, while the electron-cyclotron and Whistler waves are very efficient in accelerating electrons from a few keV to MeV energies. The presence of such an acceleration barrier prohibits the proton acceleration under solar flare conditions. This difficulty is alleviated when we include the effects of 4He in the dispersion relation and the damping of the turbulent waves by the thermal background plasma. The additional 4He cyclotron branch of the turbulent plasma waves suppresses the proton acceleration barrier significantly, and the steep turbulence spectrum in the dissipation range makes the nonthermal component have a near power-law shape. The relative acceleration of protons and electrons is very sensitive to a plasma parameter α = ωpe/Ωe, where ωpe and Ωe are the electron plasma frequency and gyrofrequency, respectively. Protons are preferentially accelerated in weakly magnetized plasmas (large α). The formalism developed here is applicable to the acceleration of other ion species and to other astrophysical systems.
Copper‐Mediated Deoxygenative Trifluoromethylation of Benzylic Xanthates: Generation of a C ? CF3 Bond from an O‐Based Electrophile

The conversion of an alcohol-based functional group, into a trifluoromethyl analogue is a desirable transformation. However, few methods are capable of converting O-based electrophiles into trifluoromethanes. The copper-mediated trifluoromethylation of benzylic xanthates using Umemoto's reagent as the source of CF3 to form C-CF3 bonds is described. The method is compatible with an array of benzylic xanthates bearing useful functional groups. A preliminary mechanistic investigation suggests that the C-CF3 bond forms by reaction of the substrate with in situ generated CuCF3 and CuOTf. Further evidence suggests that the reaction could proceed via a radical cation intermediate.
AlInAs/GaInAs/InP double heterojunction bipolar transistor with a novel base-collector design for power applications

We report the performance of an AlInAs/GaInAs/InP DHBT with a new collector design. The base-collector junction was formed with an all arsenide chirped superlattice with linear variation in the average composition. A doping dipole was inserted at the ends of the superlattice to cancel the quasielectric field. The conduction band offset between AlInAs and InP enabled hot electrons to be launched into the InP collector. The new design resulted in an excellent combination of speed and breakdown voltage with superior microwave power performance at X-band. Output power of 2 W (5.6 W/mm) with 70% power-added-efficiency at 9 GHz was achieved.
Inferring Correlation Networks from Genomic Survey Data

High-throughput sequencing based techniques, such as 16S rRNA gene profiling, have the potential to elucidate the complex inner workings of natural microbial communities - be they from the world's oceans or the human gut. A key step in exploring such data is the identification of dependencies between members of these communities, which is commonly achieved by correlation analysis. However, it has been known since the days of Karl Pearson that the analysis of the type of data generated by such techniques (referred to as compositional data) can produce unreliable results since the observed data take the form of relative fractions of genes or species, rather than their absolute abundances. Using simulated and real data from the Human Microbiome Project, we show that such compositional effects can be widespread and severe: in some real data sets many of the correlations among taxa can be artifactual, and true correlations may even appear with opposite sign. Additionally, we show that community diversity is the key factor that modulates the acuteness of such compositional effects, and develop a new approach, called SparCC (available at https://bitbucket.org/yonatanf/sparcc), which is capable of estimating correlation values from compositional data. To illustrate a potential application of SparCC, we infer a rich ecological network connecting hundreds of interacting species across 18 sites on the human body. Using the SparCC network as a reference, we estimated that the standard approach yields 3 spurious species-species interactions for each true interaction and misses 60% of the true interactions in the human microbiome data, and, as predicted, most of the erroneous links are found in the samples with the lowest diversity.
The Law and Economics of Risk Regulation

Law plays a central role in the management of risk in society. The rules adopted by regulatory agencies now affect nearly every facet of the economy, and as such regulation has motivated a substantial body of academic research. Law and economics research on regulation has, first, demonstrated the normative justification for governmental intervention in the marketplace based on the concept of market failure. Second, political economy research on regulation has shown how, as a positive matter, interest groups, political movements, and public pressure affect the stringency of such regulation, sometimes more than any normative rationale for regulation. Third, risk regulation research has clarified the available normative principles that can guide the selection of regulatory stringency, from the zero-risk principle to cost-benefit balancing. Finally, the law and economics literature on risk regulation offers lessons about the form or design of regulatory instruments, from traditional “command-and-control” standards to more innovative possibilities, such as market-based instruments or management-based regulation. Keywords: risk regulation; law and economics; regulatory instrument choice; benefit-cost analysis
Fracture Toughness of Structural Ceramics Under Biaxial Stress State by Anticlastic Bending Test

Mixed-mode fracture of structural ceramics under a biaxial stress state was investigated by an anticlastic bending test using the controlled surface flaw technique. The stress state of the anticlastic bending specimen is biaxial. This test enables the study of fractures under pure mode I, pure mode II, or any combination of mode I and mode II loading. To discuss the experimental results, a parameter T was introduced to the modified maximum hoop stress criterion. This parameter represents frictional effects of crack interfaces on the mixed-mode fracture and can be obtained experimentally. Relative magnitudes of mode I and mode II stress intensity factors and the directions of non-coplanar crack extension angles were predicted using the parameter T. Reasonable agreement with the experimental results was obtained.
Catalytic Enantioselective Intramolecular Redox Reactions: Ring-Fused Tetrahydroquinolines

The first example of a catalytic enantioselective intramolecular hydride shift/ring closure reaction is reported. This redox neutral reaction cascade allows for the efficient formation of ring-fused tetrahydroquinolines in high enantioselectivities.
Radial Velocities for 889 Late-Type Stars*

We report radial velocities for 844 FGKM-type main-sequence and subgiant stars and 45 K giants, most of which had either low-precision velocity measurements or none at all. These velocities differ from the stand- ard stars of Udry et al. by 0.035 km s � 1 (rms) for the 26 FGK standard stars in common. The zero point of our velocities differs from that of Udry et al.: hVPresentVUdry i¼þ 0:053 km s � 1 . Thus, these new velocities agree with the best known standard stars both in precision and zero point, to well within 0.1 km s � 1 . Nonetheless, both these velocities and the standards suffer from three sources of systematic error, namely, convective blueshift, gravitational redshift, and spectral type mismatch of the reference spectrum. These sys- tematic errors are here forced to be zero for G2 V stars by using the Sun as reference, with Vesta and day sky as proxies. But for spectral types departing from solar, the systematic errors reach 0.3 km s � 1 in the F and K stars and 0.4 km s � 1 in M dwarfs. Multiple spectra were obtained for all 889 stars during 4 years, and 782 of them exhibit velocity scatter less than 0.1 km s � 1 . These stars may serve as radial velocity standards if they remain constant in velocity. We found 11 new spectroscopic binaries and report orbital parameters for them. Subject headings: binaries: spectroscopic — catalogs — stars: fundamental parameters — stars: kinematics — stars: late-type — techniques: radial velocities — techniques: spectroscopic On-line material: machine-readable tables
NP with small advice

We prove a new equivalence between the non-uniform and uniform complexity of exponential time. We show that EXP /spl sube/ NP/log if and only if EXP = P/sub /spl par///sup NP/ Our equivalence makes use of a recent result due to Shaltiel and Umans showing EXP in P/sub /spl par///sup NP/ implies EXP in NP/poly.
ADHD, Values, and the Self

*The opinions expressed are the views of the author and do not necessarily reflect the policy of the National Institutes of Health, the Public Health Service, or the U.S. Department of Health and Human Services.
On the development of a multifunction millimeter-wave sensor for displacement sensing and low-velocity measurement

A new multifunction millimeter-wave sensor operating at 35.6 GHz has been developed and demonstrated for measurement of displacement and low velocity. The sensor was realized using microwave integrated circuits and monolithic microwave integrated circuits. Measured displacement results show unprecedented resolution of only 10 /spl mu/m, which is approximately equivalent to /spl lambda//sub 0//840 in terms of free-space wavelength /spl lambda//sub 0/, and maximum error of only 27 /spl mu/m. A polynomial curve-fitting method was also developed for correcting the error. Results indicate that multiple reflections dominate the displacement measurement error. The sensor was able to measure speed as low as 27.7 mm/s, corresponding to 6.6 Hz in Doppler frequency, with an estimated velocity resolution of 2.7 mm/s. A digital quadrature mixer (DQM) was configured as a phase-detecting processor, employing a quadrature sampling signal-processing technique, to overcome the nonlinear phase response problem of a conventional analog quadrature mixer. The DQM also enables low Doppler frequency to be measured with high resolution. The Doppler frequency was determined by applying linear regression on the phase sampled within only fractions of the period of the Doppler frequency. Short-term stability of the microwave signal source was also considered to predict its effect on measurement accuracy.
Transverse charge and magnetization densities in the nucleon's chiral periphery

In the light-front description of nucleon structure the electromagnetic form factors are expressed in terms of frame-independent transverse densities of charge and magnetization. Recent work has studied the transverse densities at peripheral distances b = O(M{pi}{sup -1}), where they are governed by universal chiral dynamics and can be computed in a model-independent manner. Of particular interest is the comparison of the peripheral charge and magnetization densities. We summarize (a) their interpretation as spin-independent and -dependent current matrix elements; (b) the leading-order chiral effective field theory results; (c) their mechanical interpretation in the light-front formulation; (d) the large-N_c limit of QCD and the role of {Delta} intermediate states; (e) the connection with generalized parton distributions and peripheral high-energy scattering processes.
Scheduling of manufacturing systems using the Lagrangian relaxation technique

The practical solutions for three manufacturing scheduling problems are examined. As each problem is formulated, constraints are added or modified to reflect increasing real world complexity. The first problem considers scheduling single-operation jobs on identical machines. The second problem is concerned with scheduling multiple-operation jobs with simple fork/join precedence constraints on identical machines. The third problem is the job shop problem in which multiple-operation jobs with general precedence constraints are scheduled on multiple machine types Langrangian relaxation is used to decompose each of the scheduling problems into job- or operation-level subproblems. The subproblems are easier to solve than the original problem and have intuitive appeal. This technique results in algorithms which generate near-optimal schedules efficiently, while giving a lower bound on the optimal cost. In resolving the scheduling problem from one time instant to the next, the Lagrange multipliers from the last schedule can be used to initialize the multipliers, further reducing the computation time. >
RADIATIVE TRANSFER IN A SOLAR ABSORBING PARTICLE LADEN FLOW

Solar central receivers which utilize solid thermal carriers such as sand or small refractory particles for direct absorption of concentrated solar radiation have been investigated at several laboratories. In the central receiver concept a field of tracking mirrors (heliostats) is used to focus solar energy onto a receiver mounted atop a tower. A possible receiver configuration is a cavity in which a falling sheet of solid particles is directly irradiated by the concentrated solar flux passing through the aperture. Regardless of the particular geometry, the radiative transfer within the falling particle curtain must be studied in order to determine the net radiative heating rate for the particles A discrete ordinate radiative transfer model has been applied to study the radiative coupling within the falling particle curtain. The model determines how much energy is absorbed by the particles, how much is transmitted to the rear wall of the receiver, and determines the effects of particle scattering and ther...
Learning goal hierarchies from structured observations and expert annotations

We describe a relational learning by observation framework that automatically creates cognitive agent programs that model expert task performance in complex dynamic domains. Our framework uses observed behavior and goal annotations of an expert as the primary input, interprets them in the context of background knowledge, and returns an agent program that behaves similar to the expert. We map the problem of creating an agent program on to multiple learning problems that can be represented in a "supervised concept learning'' setting. The acquired procedural knowledge is partitioned into a hierarchy of goals and represented with first order rules. Using an inductive logic programming (ILP) learning component allows our framework to naturally combine structured behavior observations, parametric and hierarchical goal annotations, and complex background knowledge. To deal with the large domains we consider, we have developed an efficient mechanism for storing and retrieving structured behavior data. We have tested our approach using artificially created examples and behavior observation traces generated by AI agents. We evaluate the learned rules by comparing them to hand-coded rules.
Investigation of a Three-Dimensional Shock Wave Separated Turbulent Boundary Layer

A detailed Investigation of a flow in which a three-dimensional shock wave separates a two-dimensional turbulent boundary layer is presented. The resulting flowfield is highly three dimensional with a significant portion of flow separation on the surface at the phi = 0 deg (windward) plane was well as a large zone of secondary surface flow off this plane. Mean and fluctuating experimental measurements were obtained throughout the entire flowfield. These measurements included mean pressures, flow angles and shear on the surface, as well as yaw angles, static pressures, turbulent shear stresses, and turbulent kinetic energies on selected planes throughout the flowfield. In addition, numerical predictions of this flow, obtained by solving the Navier-Stokes equations with an algebraic eddy viscosity turbulence model, are presented. These computations reasonably predict both the surface and flowfield quantities, despite the extremely complicated nature of the experimental flow.
Robust Extraction of Spatial Correlation

The increased variability of process parameters makes it important yet challenging to extract the statistical characteristics and spatial correlation of process variation. Recent progress in statistical static-timing analysis also makes the extraction important for modern chip designs. Existing approaches extract either only a deterministic component of spatial variation or these approaches do not consider the actual difficulties in computing a valid spatial-correlation function, ignoring the fact that not every function and matrix can be used to describe the spatial correlation. Applying mathematical theories from random fields and convex analysis, we develop: 1) a robust technique to extract a valid spatial-correlation function by solving a constrained nonlinear optimization problem and 2) a robust technique to extract a valid spatial-correlation matrix by employing a modified alternative-projection algorithm. Our novel techniques guarantee to extract a valid spatial-correlation function and matrix from measurement data, even if those measurements are affected by unavoidable random noises. Experiment results, obtained from data generated by a Monte Carlo model, confirm the accuracy and robustness of our techniques and show that we are able to recover the correlation function and matrix with very high accuracy even in the presence of significant random noises
STUDENTS' PERCEPTIONS OF ONLINE LEARNING AND INSTRUCTIONAL TOOLS: A QUALITATIVE STUDY OF UNDERGRADUATE STUDENTS USE OF ONLINE TOOLS

The purpose of this study was to describe undergraduate students' experiences and perceptions of online courses based on interviews, observations, and online focus groups. I describe (a) motivational and learner characteristics within online classes, (b) the positive and negative aspects of online courses as experienced by students, (c) what instructors can do to improve the teaching of online courses, and (d) how undergraduate students’ perceptions of the online learning environment and the tools used affects the selection of their approach to learning. Data analysis from this study produced five primary findings across the four research questions. The first finding is the role of communication in shaping students’ perceptions and approach to learning. The second finding is that participants did not perceive the negative attributes of technology to be inherent to the technology itself but in its use and implementations. Included in this second finding is that the tools used were not as important as the quality of communication and that the value assigned by students to any tool is influenced by the way the tool is implemented. The third is that course organization is key to student learning and success. The fourth is that student’ approaches to learning appeared to be shaped by both the structure of the learning environment and the nature of assessments used in the online environment. Included in this fourth finding is students’ perceptions of online learning as being less academically rigorous than their experiences in face–to–face education. The fifth is that students use nonacademic resources to locate information rather than the university library. Presentation will consist of a summary of students’ perceptions and an overview of methodology, including the movement from face-to-face focus groups to an online model and the use of think-aloud observations and interviews in collecting data on online student learning.
Does technological modularity substitute for control? A study of alliance performance in software outsourcing

Although control is presumed to be necessary to curb opportunism, its implementation in alliances can be costly and challenging. Paradoxically, some contemporary firms have counterintuitively developed successful alliances without extensive formal control. A widespread but untested assertion that might help reconcile this contradiction is that technological modularity reduces the need for alliance control. The objective of this study is to develop and test this assertion. Using data from 120 software outsourcing alliances, we show that, process control, outcome control, and modularity independently enhance alliance performance. However modularity and control are imperfect substitutes: modularity lowers the influence of process control but not of outcome control on alliance performance. Our theoretical development and empirical testing of the interactions of alliance control with modularity has significant implications for strategy theory and practice, which are also discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Enhanced electrochemical performance of solid-state ion sensors based on silicone rubber membranes

Results of optimization studies regarding the composition of silicone rubber films suitable for preparing miniaturized solid-state ion-selective sensors are presented. Using conventional macro ion-selective electrodes (ISEs) it was shown that the addition of more lipophilic ionic additives and small amounts of an appropriate plasticizer to the silicone matrix achieved optimal electroanalytical performance. The incorporation of these components into the membrane along with the required ionophore can, however, influence membrane curing time and adhesion of the film to silicon nitride surfaces. Solid-state sensors with optimized silicone membrane compositions exhibit theoretical and reproducible electrochemical performance.
On unipotent flows in H (1,1)

We study the action of the horocycle flow on the moduli space of abelian differentials in genus two. In particular, we exhibit a classification of a specific class of probability measures that are invariant and ergodic under the horocycle flow on the stratum ℋ(1,1).
Asymptotic confidence intervals for impulse responses of near‐integrated processes

Summary Many economic time series are characterized by high persistence which typically requires nonstandard limit theory for inference. This paper proposes a new method for constructing confidence intervals for impulse response functions and half-lives of nearly nonstationary processes. It is based on inverting the acceptance region of the likelihood ratio statistic under a sequence of null hypotheses of possible values for the impulse response or the half-life. This paper shows the consistency of the restricted estimator of the localizing constant which ensures the validity of the asymptotic inference. The proposed method is used to study the persistence of shocks to real exchange rates.
Aeroelastic effects of battens on the flight dynamics of a MAV

Wing flexibility is well established as providing gust rejection and delayed onset of stall for micro air vehicles. As such, many designs adopt wings of a flexible material mounted onto a skeleton comprised of a stiff leading-edge spar and stiff chordwise strips, called battens. These battens are shown to provide additional strength at localised regions of the wing and thus improve the gust rejection and delay stall; however, their effect on the flight dynamics is less studied. Using a numerical modeling approach, this paper explores a design space of vehicles with a varied number of wing battens mounted onto a baseline vehicle with a flexible wing. The battens are modelled as stepwise changes in torsional stiffness along the wing span. The resulting trim characteristics, static stability metrics and flight dynamics are evaluated. The battens are shown to improve gust rejection but otherwise have a complicated effect across the design space. A reduction in the number of battens improves the longitudinal static stability derivative slightly but lowers the lateral and directional static stability. The damping is decreased for the short period mode and increased for the phugoid and dutch roll modes as the number of battens is reduced.
CONFORMAL FIXED POINTS OF UNIDENTIFIED GAUGE THEORIES

In this article we discuss gauge/string correspondence based on the non-critical strings. With this goal we present several remarkable sigma models with the AdS target spaces. The models have kappa symmetry and are completely integrable. The radius of the AdS space is fixed and thus they describe isolated conformal fixed points of gauge theories in various dimensions. This work is dedicated to the memory of Ian Kogan.
Model-independent Analyses of Dark-Matter Particle Interactions

Abstract A model-independent treatment of dark-matter particle elastic scattering has been developed, yielding the most general interaction for WIMP-nucleon low-energy scattering, and the resulting amplitude has been embedded into the nucleus, taking into account the selection rules imposed by parity and time-reversal. One finds that, in contrast to the usual spin-independent/spin-dependent (SI/SD) formulation, the resulting cross section contains six independent nuclear response functions, three of which are associated with possible velocity-dependent interactions. We find that current experiments are four orders of magnitude more sensitive to derivative couplings than is apparent in the standard SI/SD treatment, which necessarily associated such interactions with cross sections proportional to v2T ∼ 10−6, where vT is the WIMP velocity relative to the center of mass of the nuclear target.
A lattice with no transition and large dynamic aperture

In the case of a one-ring high-energy scheme for an advanced hadron facility, beam losses can be reduced if the ring lattice accommodates the beam from injection to maximum energy without crossing the transition. Since there is no synchrotron booster in such a scheme and the injection energy is relatively low, this requirement implies a negative compaction factor and an imaginary transition energy. This can be achieved by making the horizontal dispersion negative in some regions of the arcs so that the average value taken in the dipoles is globally also negative. Such a modulation of the dispersion may make it increasingly difficult to obtain a large enough dynamic aperture in the presence of sextupoles. A careful optimization is therefore necessary, and the possibility of modifying the linear lattice in order to include the requirements associated with chromaticity adjustments has to be studied. Work done along this line is summarized, with attention given to a racetrack lattice that can be used in a hadron facility main ring. An alternative lattice design which tends to minimize the effects of the nonlinear aberrations introduced by sextupoles and to achieve a large dynamic aperture, keeping the betatron amplitudes as low as possible, is described. >