cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of penalty design in penalized maximum-likelihood image reconstruction for lesion detection

Detecting cancerous lesions is a major clinical application in emission tomography. Previously, we developed a method to design a shift-variant quadratic penalty function in penalized maximum-likelihood (PML) image reconstruction to improve the lesion detectability. We used a multiview channelized Hotelling observer (mvCHO) to assess the lesion detectability in three-dimensional images and validated the penalty design using computer simulations. In this study, we evaluate the benefit of the proposed penalty function for lesion detection using real patient data and artificial lesions. A high-count real patient dataset with no identifiable tumor inside the field of view is used as the background data. A Na-22 point source is scanned in air at variable locations and the point source data are superimposed onto the patient data as artificial lesions after being attenuated by the patient body. Independent Poisson noise is introduced to the high-count sinograms to generate 200 pairs of lesion-present and lesion-absent datasets, each mimicking a 5-min scan. Lesion detectability is assessed using a mvCHO and a human observer two-alternative forced choice (2AFC) experiment. The results show improvements in lesion detection by the proposed method compared with the conventional first-order quadratic penalty function and a total variation (TV) edge-preserving penalty function.
A novel W-band spectrometer for dielectric measurements

A new spectrometer for the precision measurement of dielectric permittivity and loss tangent is presented. The new instrument is capable of providing high-resolution data for the first time over an extended W-band (68-118 GHz) frequency for specimens with a large range of absorption values, including highly absorbing specimens that otherwise would not be possible. A novel technique based on the unbalanced bridge is developed for the measurement of the phase of the wave passed through the specimen in free space (quasi-optical) with reference provided by a waveguide arm. Specially constructed precision waveguide and quasi-optical components allowed reliable broadband operation. A number of common dielectrics are measured, and results are compared with previously reported data.
Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

The concept of frustrated Lewis pairs (FLPs) has received considerable attention of late, and numerous reports have demonstrated the power of non- or weakly interacting Lewis acid–base pairs for the cooperative activation of small molecules. Although most studies have focused on the use of organic or main-group FLPs that utilize steric encumbrance to prevent adduct formation, a related strategy can be envisioned for both organic and inorganic complexes, in which "electronic frustration" engenders reactivity consistent with both nucleophilic (basic) and electrophilic (acidic) character. Here we propose that such a description is consistent with the behavior of many coordinatively unsaturated transition-metal species featuring metal–ligand multiple bonds, and we further demonstrate that the resultant reactivity may be a powerful tool for the functionalization of C–H and E–H bonds.
Impact of soil texture on the distribution of soil organic matter in physical and chemical fractions

Previous research on the protection of soil organic C from decomposition suggests that soil texture affects soil C stocks. However, different pools of soil organic matter (SOM) might be differently related to soil texture. Our objective was to examine how soil texture differentially alters the distribution of organic C within physically and chemically defined pools of unprotected and protected SOM. We collected samples from two soil texture gradients where other variables influencing soil organic C content were held constant. One texture gradient (16–60% clay) was located near Stewart Valley, Saskatchewan, Canada and the other (25–50% clay) near Cygnet, OH. Soils were physically fractionated into coarse- and fine-particulate organic matter (POM), silt- and clay-sized particles within microaggregates, and easily dispersed silt- and clay-sized particles outside of microaggregates. Whole-soil organic C concentration was positively related to silt plus clay content at both sites. We found no relationship between soil texture and unprotected C (coarse- and fine-POM C). Biochemically protected C (nonhydrolyzable C) increased with increasing clay content in whole-soil samples, but the proportion of nonhydrolyzable C within silt- and clay-sized fractions was unchanged. As the amount of silt or clay increased, the amount of C stabilized within easily dispersed and microaggregate-associated silt or clay fractions decreased. Our results suggest that for a given level of C inputs, the relationship between mineral surface area and soil organic matter varies with soil texture for physically and biochemically protected C fractions. Because soil texture acts directly and indirectly on various protection mechanisms, it may not be a universal predictor of whole-soil C content.
sub-SAT: a formulation for relaxed Boolean satisfiability with applications in routing

Advances in methods for solving Boolean satisfiability (SAT) for large problems have motivated recent attempts to recast physical design problems as Boolean SAT problems. One persistent criticism of these approaches is their inability to supply partial solutions, i.e., to satisfy most but not all of the constraints cast in the SAT style. In this paper, we present a formulation for "subset satisfiable" Boolean SAT: we transform a "strict" SAT problem with N constraints into a new, "relaxed" SAT problem which is satisfiable just if not more than k/spl Lt/N of these constraints cannot be satisfied in the original problem. We describe a transformation based on explicit thresholding and counting for the necessary SAT relaxation. Examples from field-programmable gate-array routing show how we can determine efficiently when we can satisfy "almost all" of our geometric constraints.
GENERALIZED SIGMA MODEL DESCRIPTION OF THE LIGHT J = 0 MESONS

Within a linear sigma model framework, possible mixing between two chiral nonets (a two quark nonet, and a four quark nonet) below 2 GeV is studied. Incorporating the U(1)A behavior of the underlying QCD, and working in the isospin invariant limit, the mass spectra of the I = 0, I = 1/2 and I = 1 pseudoscalars, and the I = 1/2 scalars are studied, and estimates of their quark content are presented. It is found, as expected, that the ordinary and the excited pseudoscalars generally have much less two and four quark admixtures compared to the respective scalars. As by-products, several quantities such as the four quark vacuum condensate, and the decay constant of excited states are predicted.
Detection of Planetary Emission from the Exoplanet TrES-2 Using Spitzer/IRAC

We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting decrease in flux is 0.127% ± 0.021%, 0.230% ± 0.024%, 0.199% ± 0.054%, and 0.359% ± 0.060% at 3.6 μm, 4.5 μm, 5.8 μm, and 8.0 μm, respectively. We show that three of these flux contrasts are well fit by a blackbody spectrum with T_(eff) = 1500 K, as well as by a more detailed model spectrum of a planetary atmosphere. The observed planet-to-star flux ratios in all four IRAC channels can be explained by models with and without a thermal inversion in the atmosphere of TrES-2, although with different atmospheric chemistry. Based on the assumption of thermochemical equilibrium, the chemical composition of the inversion model seems more plausible, making it a more favorable scenario. TrES-2 also falls in the category of highly irradiated planets which have been theoretically predicted to exhibit thermal inversions. However, more observations at infrared and visible wavelengths would be needed to confirm a thermal inversion in this system. Furthermore, we find that the times of the secondary eclipses are consistent with previously published times of transit and the expectation from a circular orbit. This implies that TrES-2 most likely has a circular orbit, and thus does not obtain additional thermal energy from tidal dissipation of a non-zero orbital eccentricity, a proposed explanation for the large radius of this planet.
A low-swing clock double-edge triggered flip-flop

A low-swing clock double-edge triggered flip-flop (LSDFF) is developed to reduce power consumption significantly compared to conventional flip-flops. The LSDFF avoids unnecessary internal node transitions to reduce power consumption. In addition, power consumption in the clock tree is reduced because LSDFF uses a double-edge triggered operation as well as a low-swing clock. To prevent performance degradation of the LSDFF due to low-swing clock, low-V/sub t/ transistors are used for the clocked transistors without significant leakage current problems. The power saving in flip-flop operation is estimated to be 28.6% to 49.6% with additional 78% power saving in the clock network.
Computational Studies of Chiral Catalysts: A Comparative Molecular Field Analysis of an Asymmetric Diels−Alder Reaction with Catalysts Containing Bisoxazoline or Phosphinooxazoline Ligands

A QSAR using Comparative Molecular Field Analysis (CoMFA) is developed for a set of 23 catalysts containing bisoxazoline or phosphinooxazoline ligands that are known to induce asymmetry during the Diels−Alder reaction of N-2-alkenoyl-1,3-oxazolidine-2-one with cyclopentadiene. It is shown that extremely high q2 statistics can be derived by using standard modeling protocols when internal validation alone is done as well as when an external test set is used. From these models it is shown that approximately 70% of the variance in the observed enantiomeric excess can be attributed to the steric field and the remainder of the variance to the electrostatic field. Suggestions about how to improve the performance of inefficient catalysts are given.
WebFlow - High-Level Programming Environment and Visual Authoring Toolkit for High Performance Distributed Computing

We developed a platform independent, three-tier system, called WebFlow. The visual authoring tools implemented in the front end integrated with the middle tier network of servers based on the industry standards and following distributed object paradigm, facilitate seamless integration of commodity software components. We add high performance to commodity systems using GLOBUS metacomputing toolkit as the backend. We have explained these ideas in general before, and here for the first time we describe a fully operational example which is expected to be deployed in an NCSA Alliance Grand Challenge.
Composite Adaptation for Neural Network-Based Controllers

With the motivation of using more information to update the parameter estimates to achieve improved tracking performance, composite adaptation that uses both the system tracking errors and a prediction error containing parametric information to drive the update laws, has become widespread in adaptive control literature. However, despite its obvious benefits, composite adaptation has not been widely implemented in neural network-based control, primarily due to the neural network (NN) reconstruction error that destroys a typical prediction error formulation required for the composite adaptation. This technical note presents a novel approach to design a composite adaptation law for NNs by devising an innovative swapping procedure that uses the recently developed robust integral of the sign of the error (RISE) feedback method. Semi-global asymptotic tracking is proven for a Euler-Lagrange system. Experimental results are provided to illustrate the concept.
A Computational and Experimental Study of Resonators in Three Dimensions

In a previous work by the present authors, a computational and experimental investigation of the acoustic properties of two-dimensional slit resonators was carried out. The present paper reports the results of a study extending the previous work to three dimensions. This investigation has two basic objectives. The first is to validate the computed results from direct numerical simulations of the flow and acoustic fields of slit resonators in three dimensions by comparing with experimental measurements in a normal incidence impedance tube. The second objective is to study the flow physics of resonant liners responsible for sound wave dissipation. Extensive comparisons are provided between computed and measured acoustic liner properties with both discrete frequency and broadband sound sources. Good agreements are found over a wide range of frequencies and sound pressure levels. Direct numerical simulation confirms the previous finding in two dimensions that vortex shedding is the dominant dissipation mechanism at high sound pressure intensity. However, it is observed that the behavior of the shed vortices in three dimensions is quite different from those of two dimensions. In three dimensions, the shed vortices tend to evolve into ring (circular in plan form) vortices, even though the slit resonator opening from which the vortices are shed has an aspect ratio of 2.5. Under the excitation of discrete frequency sound, the shed vortices align themselves into two regularly spaced vortex trains moving away from the resonator opening in opposite directions. This is different from the chaotic shedding of vortices found in two-dimensional simulations. The effect of slit aspect ratio at a fixed porosity is briefly studied. For the range of liners considered in this investigation, it is found that the absorption coefficient of a liner increases when the open area of the single slit is subdivided into multiple, smaller slits.
Modeling intermediate tests for fault-tolerant multichip module systems

This paper presents analytical models for evaluating intermediate tests for yield enhancement and quality assurance of systems manufactured using fault-tolerant multichip modules (MCM's) for massively parallel computing (MPC). In the proposed approaches, we employ both a novel Markov model and a so-called working-test-set to compute the yield. Unlike a previous method which utilizes a binomial distribution, our scheme can employ intermediate tests to meet MCM quality requirements effectively. Several strategies for appropriately testing fault-tolerant MCM's have been proposed, but little analytical evaluation has been performed. In this paper, it is shown that an efficient test strategy with a modest level of redundancy may exist to achieve virtually 100% first-pass MCM yield for a particular system. We note that a yield-analysis model employing the LRTWS (Least Recently Tested in WS) test strategy proposed in this paper may provide a very good figure of merit due to its cost, delivery, number of tests and reliability benefits for current technology. Extensive parametric results for the analysis are provided to show that our approach can be applied to calculate the overall yield for fault-tolerant MCM's more accurately and efficiently, thereby improving upon the reliability and quality of the entire system. >
Computing core/periphery structures and permutation tests for social relations data

The core/periphery structure is ubiquitous in network studies. The discrete version of the concept is that individuals in a group belong to either the core, which has a high density of ties, or to the periphery, which has a low density of ties. The density of ties between the core and the periphery may be either high or low. If the core/periphery structure is given a priori, then there is no problem in finding a suitable statistical test. Often, however, the structure is not given, which presents us with two problems, searching for the optimal core/periphery structure, and devising a valid statistical test to replace the one invalidated by the search. UCINET [Borgatti, S.P., Everett, M.G., Freeman, L.C., 2002. UCINET for Windows, Version 6.59: Software for Social Network Analysis. Analytic Technologies, Harvard], the oldest and most trusted network program, gives incorrect answers in some simple cases for the first problem and does not address the second. This paper solves both problems with an adaptation of the Kernighan–Lin search algorithm, and with a permutation test incorporating this algorithm. © 2005 Elsevier B.V. All rights reserved.
Length spectra and degeneration of flat metrics

In this paper we consider flat metrics (semi-translation structures) on surfaces of finite type. There are two main results. The first is a complete description of when a set of simple closed curves is spectrally rigid, that is, when the length vector determines a metric among the class of flat metrics. Secondly, we give an embedding into the space of geodesic currents and use this to obtain a compactification for the space of flat metrics. The geometric interpretation is that flat metrics degenerate to mixed structures on the surface: part flat metric and part measured foliation.
Jitter model and signal processing techniques for pulse width modulation optical recording

A jitter model and signal processing techniques for data recovery in pulse-width modulation (PWM) optical recording are discussed. In PWM, information is stored through modulating sizes of sequential marks alternating in magnetic polarization or in material structure. Jitter, defined as the deviation from the original mark size in the time domain, will result in error detection if it is excessively large. A new approach is taken for data recovery by first using a high speed counter clock to convert time-marks to amplitude-marks, and signal processing techniques are used to minimize jitter according to the jitter model. The signal processing techniques include motor speed and intersymbol interference equalization, differential and additive detection, and differential and additive modulation. >
Vortex Deconfinement in the XY Model with a Magnetic Field

Abstract We study vortex unbinding for the classical two-dimensional XY model in a magnetic field on square and triangular lattices. A renormalization group analysis combined with duality in the model shows that at high temperature and high field, the vortices unbind as the magnetic field is lowered in a two-step process: strings of overturned spins first proliferate and then vortices unbind. The transitions are highly continuous but are not of the Kosterlitz–Thouless type. The unbound vortex fixed point is shown to inherit properties of the underlying lattice, in particular containing a set of nodal lines that reflect the lattice symmetry.
A sharper view of the outer Galaxy at 1420 and 408 MHz from the Canadian Galactic Plane Survey II: the catalogue of extended radio sources

A new catalogue of extended radio sources has been prepared based on arcminute-resolution 1420-MHz images from the Canadian Galactic Plane Survey (CGPS). The new catalogue provides both 1420- and 408-MHz flux density measurements on sources found near the Galactic plane in the second quadrant of our Galaxy. In addition cross-identifications are made with other major radio catalogues and information is provided to facilitate the recovery of CGPS image data associated with each catalogued source. Numerous new radio sources are identified and the catalogue provides a comprehensive summary of both newly discovered and previously known H ii regions and supernova remnants in the outer Galaxy. The catalogue should be of use both for synoptic studies of Galactic structure and for placing higher resolution observations, at radio and other wavelengths, in context.
Bioethics of Organ Transplantation

As the ability to transplant organs and tissues has grown, the demand for these procedures has increased as well--to the point at which it far exceeds the available supply creating the core ethical challenge for transplantation--rationing. The gap between supply and demand, although large, is worse than it appears to be. There are two key steps to gaining access to a transplant. First, one must gain access to a transplant center. Then, those waiting need to be selected for a transplant. Many potential recipients do not get admitted to a program. They are deemed too old, not of the right nationality, not appropriate for transplant as a result of severe mental impairment, criminal history, drug abuse, or simply because they do not have access to a competent primary care physician who can refer them to a transplant program. There are also financial obstacles to access to transplant waiting lists in the United States and other nations. In many poor nations, those needing transplants simply die because there is no capacity or a very limited capacity to perform transplants. Although the demand for organs now exceeds the supply, resulting in rationing, the size of waiting lists would quickly expand were there to suddenly be an equally large expansion in the number of organs available for transplantation. Still, even with the reality of unavoidable rationing, saving more lives by increasing organ supply is a moral good. Current public policies for obtaining organs from cadavers are not adequate in that they do not produce the number of organs that public polls of persons in the United States indicate people are willing to donate.
Aerosol Monitoring by Satellite Horizon Scanning

A newly adapted horizon-scanning technique can simultaneously monitor the vertical distribution of aerosols, as well as ozone and neutral atmospheric density, in the stratosphere and mesosphere for both meteorological and ecological application in a global satellite-monitoring program. The horizon-inversion technique permits the conversion of scattered solar-radiation horizon (limb) profiles into the vertical distribution of aerosol extinction coefficients. Results are given based on real and simulated experimental data which indicate that the aerosol layers can be identified and that the potential exists for estimating the physical characteristics of aerosols within a layer. TRATOSPHERIC distributions of aerosols have been drawing increasing attention as a result of new knowledge concerning their role in the Earth's radiation balance. These particles are now known to cause temperature changes both in the stratosphere and at the Earth's surface. Of particular interest is the aerosol vertical distribution which is influenced both by man-made environmental pollutants and by natural phenomena. This paper describes a mathematical technique of horizon- radiance inversion developed to recover the vertical distribu- tion of aerosol extinction and, coincidentally, ozone and neu- tral atmospheric density in the stratosphere and mesosphere.l The technique provides for the inversion of horizon-intensity profiles obtained by scanning the Earth's sunlit horizon with a satellite-borne sensor. In this experimental configura- tion, a satellite-base d sensor with a limited field of view mechanically scans the Earth's horizon (Fig. 1) in a multispec- tral mode, allowing the aerosols to be distinguished from other atmospheric constituents, such as the neutral atmosphere and ozone. The sensor output is inverted by applying a Kalman-Bucy recursive filter to the received signal, using a reference-intensity profile generated by a theoretical radia- tive-transfer simulation. When the scattering or absorption cross sections are well known (as in the case of ozone and the neutral atmosphere), the received multispectral signals are inver- ted to yield constituent-density information. When the cross sections are not well known, however—as in the case of aerosols—the extinction profile is obtained directly from the inversion. Further development of this horizon-inversion
A proposal to pulse the Bevatron/Bevalac main guide field magnet with SCR power supplies

The Bevatron/Bevalac main guide field power supply was originally designed to provide a 15250-V DC at 8400-A peak magnet pulse. Protons were accelerated to 6.2 GeV. The 128-MW pulse required two large motor-generator (MG) sets with 67-ton flywheels to store 680 MJ of energy. Ignitron rectifiers are used to rectify the generator outputs. Acceleration of heavy ions results in an operating schedule with a broad range of peak fields. The maximum field of 12.5 kG requires a peak pulse of 80 MW. Acceleration of ions to 1.0 kG requires an 8-MW peak pulse. One MG set can provide pulses below 45 MW. Peak pulses of less than 15 MW are now a large block of the operating schedule. A proposal has been made to replace the existing MG system with eight silicon controlled rectifier (SCR) power supplies for low field operation. The SCR supplies will be powered directly from the Lawrence Berkeley Laboratory's 12.3-kV power distribution system. It is concluded that the implementation of this proposal will benefit Bevaton/Bevalac operations by reducing operating costs and improving beam quality. It is noted that the ability to achieve a requested field without extensive Ignitron warmup would, by itself, be justification for the concept. >
Cubanos en México: “dos mexicanos más"

Globalization in contemporary life suggests the suitability for redefining the role and place in national literary historiography for those “foreign born” in order to determine how and to what point they belong to the culture and literary history of another nation. This essay examines the issue using the example of two Cuban figures, both exiled from their homeland and who identified themselves with literary and political life in Mexico. We are dealing with Jose Marti and Jose Maria Heredia, who lived and wrote in Mexico, identified themselves with national life, and, in the case of Heredia, occupied official positions in the government. We are proposing to clarify if they are Cubans or “two more Mexicans,” and to what point do their works respond to the influence of the Mexican literary environment and its correspondent traditions, modes and linguistic codes.
High-speed VLSI architecture for parallel Reed-Solomon decoder

This paper presents high-speed parallel Reed-Solomon (RS) (255,239) decoder architecture using modified Euclidean algorithm for the high-speed multigigabit-per-second fiber optic systems. Pipelining and parallelizing allow inputs to be received at very high fiber-optic rates and outputs to be delivered at correspondingly high rates with minimum delay. A parallel processing architecture results in speed-ups of as much as or more than 10 Gb, since the maximum achievable clock frequency is generally bounded by the critical path of the modified Euclidean algorithm block. The parallel RS decoders have been designed and implemented with the 0.13-/spl mu/m CMOS standard cell technology in a supply voltage of 1.1 V. It is suggested that a parallel RS decoder, which can keep up with optical transmission rates, i.e., 10 Gb/s and beyond, could be implemented. The proposed channel = 4 parallel RS decoder operates at a clock frequency of 770 MHz and has a data processing rate of 26.6 Gb/s.
Expectant management of veterans with early-stage prostate cancer.

BACKGROUND For certain men with low-risk prostate cancer, aggressive treatment results in marginal survival benefits while exposing them to urinary and sexual side effects. Nevertheless, expectant management has been underused. In the current study, the authors evaluated the association between various factors and expectant management use among veterans diagnosed with prostate cancer. METHODS The authors identified men diagnosed with prostate cancer in 2008. The outcome of interest was use of expectant management, based on documentation captured through an in-depth chart review. Multivariable regression models were fit to examine associations between use of expectant management and patient demographics, cancer severity, and facility characteristics. The authors assessed variation across 21 tertiary care regions and 52 facilities by generating predicted probabilities for receipt of expectant management. RESULTS Expectant management was more common among patients aged ≥75 years (40% vs 27% for those aged .05). Among ideal candidates for expectant management, receipt of expectant management varied considerably across individual facilities (0%-85%; P<.001). CONCLUSIONS Patient age and tumor risk were found to be more strongly associated with use of expectant management than patient comorbidity. Although use of expectant management appears broadly appropriate, there was variation in expectant management noted between hospitals that was apparently not attributable to facility factors. Research determining the basis of this variation, with a focus on providers, will be critical to help optimize prostate cancer treatment for veterans. Cancer 2016;122:626–633. © 2015 American Cancer Society.
Coding Strategies in Monkey V1 and Inferior Temporal Cortices

Gershon, Ethan D., Matthew C. Wiener, Peter E. Latham, and Barry J. Richmond. Coding strategies in monkey V1 and inferior temporal cortices. J. Neurophysiol. 79: 1135–1144, 1998. We would like to k...
Effect of tissue preservation on imaging using ultrahigh resolution optical coherence tomography

Ultrahigh resolution optical coherence tomography OCT is an emerging imaging modality that enables noninvasive imaging of tissue with 1- to 3-m resolutions. Initial OCT studies have typically been performed using harvested tissue specimens ex vivo .N o re- ports have investigated postexcision tissue degradation on OCT image quality. We investigate the effects of formalin fixation and commonly used cell culture media on tissue optical scattering characteristics in OCT images at different times postexcision compared to in vivo con- ditions. OCT imaging at 800-nm wavelength with 1.5-m axial reso- lution is used to image the hamster cheek pouch in vivo, followed by excision and imaging during preservation in phosphate-buffered sa- line PBS, Dulbecco's Modified Eagle's Media DMEM, and 10% neutral-buffered formalin. Imaging is performed in vivo and at se- quential time points postexcision from 15 min to 10 to 18 h. Formalin fixation results in increases in scattering intensity from the muscle layers, as well as shrinkage of the epithelium, muscle, and connective tissue of 50%. PBS preservation shows loss of optical contrast within two hours, occurring predominantly in deep muscle and con- nective tissue. DMEM maintains tissue structure and optical scattering characteristics close to in vivo conditions up to 4 to 6h after excision and best preserved tissue optical properties when compared to in vivo imaging. © 2005 Society of Photo-Optical Instrumentation Engineers.
Pluralism, Academic Freedom, and Heterodox Economics

Frederic Lee’s laudable attempt to expand heterodox economists’ academic rights is vitiated by his narrow conception of pluralism as tolerance. The author proposes an alternative view of academic p...
Isolated Boost Converters

Two implementations of the isolated boost converter that exhibit no parasitic voltage ringing across all semiconductor devices on the primary and secondary sides of the transformer are introduced. Ringing-free operation is achieved by clamping the voltages of the primary switches and rectifiers to the voltage of the primary-side energy-storage capacitor and clamping the voltage across the secondary-side rectifiers to the output filter capacitor. The performance of the proposed topology was verified on a dual ac-input, 900-W experimental prototype operating at 67 kHz.
The Concept of Hope and Its Relevance to Product Evaluation and Choice

Abstract This conceptual article uses an appraisal theory perspective to define the construct of hope and describe its relevance to consumer behavior, marketing, and public policy in the domains of product evaluation and choice. Using the appraisal dimensions of hope, the authors identify a set of marketing tactics that are designed to stimulate hope. They posit that hope plays a moderating role in the relationship between well-known antecedent variables (e.g., involvement, expectations) on the one hand and evaluative judgments (e.g., attitudes, satisfaction) and consumer choices on the other hand. The authors advance specific propositions that describe the effects. Furthermore, they argue that the effects have implications for marketing and public policy. The article concludes with a call for additional research relevant to the study of hope.
Stable wide‐angle Fourier finite‐difference downward extrapolation of 3‐D wavefields

I present an unconditionally stable, implicit finite‐difference operator that corrects the constant‐velocity phase‐shift operator for lateral velocity variations. The method is based on the Fourier finite‐difference (FFD) method. Contrary to previous results, my correction operator is stable even when the medium velocity has sharp discontinuities, and the reference velocity is higher than the medium velocity. The stability of the new correction enables the definition of a new downward‐continuation method based on the interpolation of two wavefields: the first wavefield is obtained by applying the FFD correction starting from a reference velocity lower than the medium velocity; the second wavefield is obtained by applying the FFD correction starting from a reference velocity higher than the medium velocity. The proposed Fourier finite‐difference plus interpolation (FFDPI) method combines the advantages of the FFD technique with the advantages of interpolation.A simple and economical procedure for defining ...
A Simple Theory of Capillary-Gravity Wave Turbulence

Employing a recently proposed 'multi-wave interaction' theory [JFM, 243, 623-625], spectra of capillary-gravity waves are derived. This case is characterized by a rather high degree of nonlinearity and a complicated dispersion law. The resultant absence of scale invariance makes this and some other problems of wave turbulence (e.g., nonlinear Rossby waves) intractable by small-perturbation techniques, even in the weak turbulence limit. The analytical solution obtained in the present work is shown to be in good agreement with experimental data. Its low- and high-frequency limits yield power-laws characterizing spectra of purely gravity and capillary waves, respectively. In the limits of weak and strong linearity, these reduce of the Zakharov-Filonenko and Phillips spectra, respectively.
Robust Alignment of Multi-view Range Data to CAD Model

Surface matching is a common task in computer graphics and computer vision. In this paper, we introduce a novel algorithm that aligns scanned point-based surfaces to the related 3D model without assumptions about their relative position and orientation. Our method estimates the transformation that matches two surfaces from a pair of corresponding points using their surface positions, normals and principal curvature directions. This approximate alignment is used as the input of ICP algorithm to refine the registration of the surface to the model. The algorithm is easy to implement and proved to be reliable even with coarse point clouds. Furthermore, with the help of multi-scale feature points, we can improve the reliability of our surface matching algorithm
PhyloCSF: a comparative genomics method to distinguish protein coding and non-coding regions

Motivation: As high-throughput transcriptome sequencing provides evidence for novel transcripts in many species, there is a renewed need for accurate methods to classify small genomic regions as protein coding or non-coding. We present PhyloCSF, a novel comparative genomics method that analyzes a multispecies nucleotide sequence alignment to determine whether it is likely to represent a conserved protein-coding region, based on a formal statistical comparison of phylogenetic codon models. Results: We show that PhyloCSF’s classification performance in 12-species Drosophila genome alignments exceeds all other methods we compared in a previous study. We anticipate that this method will be widely applicable as the transcriptomes of many additional species, tissues and subcellular compartments are sequenced, particularly in the context of ENCODE and modENCODE, and as interest grows in long non-coding RNAs, often initially recognized by their lack of protein coding potential rather than conserved RNA secondary structures. Availability and Implementation: The Objective Caml source code and executables for GNU/Linux and Mac OS X are freely available at
Coupled 802.11 flows in urban channels: model and experimental evaluation

Contending flows in multihop 802.11 wireless networks compete with two fundamental asymmetries: 1) channel asymmetry, in which one flow has a stronger signal, potentially yielding physical layer capture; and 2) topological asymmetry, in which one flow has increased channel state information, potentially yielding an advantage in winning access to the channel. Prior work has considered these asymmetries independently with a highly simplified view of the other. However, in this paper, we perform thousands of measurements on coupled flows in urban environments and build a simple yet accurate model that jointly considers information and channel asymmetries. We show that if these two asymmetries are not considered jointly, throughput predictions of even two coupled flows are vastly distorted from reality when traffic characteristics are only slightly altered (e.g., changes to modulation rate, packet size, or access mechanism). These performance modes are sensitive not only to small changes in system properties, but also small-scale link fluctuations that are common in an urban mesh network. We analyze all possible capture relationships for two-flow subtopologies and show that capture of the reverse traffic can allow a previously starving flow to compete fairly. Finally, we show how to extend and apply the model in domains such as modulation rate adaptation and understanding the interaction of control and data traffic.
Low Velocity Friction Compensation and Feedforward Solution Based on Repetitive Control

One of the most significant sources of tracking error for an X-Y table is static friction, a nonlinear disturbance at low velocity. In traversing a circular profile, an X-Y table encounters zero velocity crossings at ninety degree intervals around the circle, leaving relatively large tracking errors referred to as “quadrant glitches.” To learn the control input which eliminates errors caused by stiction, repetitive control, a subclass of learning control, is employed. Experiments, conducted on the X-Y bed of a CNC milling machine, demonstrate that near-perfect tracking can be achieved in twelve cycles or less. Of particular interest is the velocity command input generated by repetitive control. The input contains feedforward information for developing perfect trajectories at low velocities.
The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function

We present results from an adaptive optics survey for substellar and stellar companions to Sun-like stars. The survey targeted 266 F5-K5 stars in the 3 Myr-3 Gyr age range with distances of 10-190 pc. Results from the survey include the discovery of two brown dwarf companions (HD 49197B and HD 203030B), 24 new stellar binaries, and a triple system. We infer that the frequency of 0.012-0.072 M_☉ brown dwarfs in 28-1590 AU orbits around young solar analogs is 3.2^(+3.1)_(–2.7%) (2σ limits). The result demonstrates that the deficiency of substellar companions at wide orbital separations from Sun-like stars is less pronounced than in the radial velocity "brown dwarf desert." We infer that the mass distribution of companions in 28-1590 AU orbits around solar-mass stars follows a continuous dN/dM_(2)∝ M^(–0.4)_2 relation over the 0.01-1.0 M_☉ secondary mass range. While this functional form is similar to that for isolated objects less than 0.1 M_☉ , over the entire 0.01-1.0 M_☉ range, the mass functions of companions and of isolated objects differ significantly. Based on this conclusion and on similar results from other direct imaging and radial velocity companion surveys in the literature, we argue that the companion mass function follows the same universal form over the entire range between 0 and 1590 AU in orbital semimajor axis and ≈ 0.01-20 M_☉ in companion mass. In this context, the relative dearth of substellar versus stellar secondaries at all orbital separations arises naturally from the inferred form of the companion mass function.
Nystrom Approximation for Large-Scale Determinantal Processes

Determinantal point processes (DPPs) are appealing models for subset selection problems where diversity is desired. They oer surprisingly ecient inference, including sam
Protein and Chemical Microarrays—Powerful Tools for Proteomics

In the last few years, protein and chemical microarrays have emerged as two important tools in the field of proteomics. Specific proteins, antibodies, small molecule compounds, peptides, and carbohydrates can now be immobilized on solid surfaces to form high-density microarrays. Depending on their chemical nature, immobilization of these molecules on solid support is accomplished by in situ synthesis, nonspecific adsorption, specific binding, nonspecific chemical ligation, or chemoselective ligation. These arrays of molecules can then be probed with complex analytes such as serum, total cell extracts, and whole blood. Interactions between the analytes and the immobilized array of molecules are evaluated with a number of different detection systems. In this paper, various components, methods, and applications of the protein and chemical microarray systems are reviewed.
Aqueous and biphasic nitrile hydration catalyzed by a recyclable Ru(II) complex under atmospheric conditions

[RuCl2(PTA)4] (PTA = 1,3,5-triaza-7-phosphaadamantane) was found to be a highly active catalyst for aqueous phase nitrile hydration at 100 °C in air. Near quantitative conversion of aromatic, alkyl, and vinyl nitriles to their corresponding amides was observed. The reaction tolerated ether, hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Some amides were isolated by simple decantation from the aqueous phase catalyst. Catalyst loading down to 0.001 mol% was examined with turnover numbers as high as 22000 observed. The catalyst was stable for weeks in solution and could be reused more than five times without significant loss of activity.
The Operational Consequences of Private Equity Buyouts: Evidence from the Restaurant Industry

How do private equity firms affect their portfolio companies? We document operational changes in restaurant chain buyouts between 2002 and 2012 using comprehensive health inspection records in Florida. Storelevel operational practices improve after private equity buyout, as restaurants become cleaner, safer, and better maintained. Supporting a causal interpretation, this effect is stronger in chain-owned stores than in franchised locations—“twin” restaurants over which private equity owners have limited control. Private equity targets also slightly reduce employee headcount and lower menu prices. These changes to store-level operations are particularly apparent when private equity partners have prior experience in the restaurant industry. Such improvements require monitoring, training, and better alignment of worker incentives, suggesting private equity firms engage in operational engineering and improve management practices throughout the organization.
Analysis of the photodiode boundary layer transition indicator

The photodiode transition indicator is a device that has been successfully used to determine the onset of boundary-layer transition on numerous hypersonic flight vehicles. The exact source of the electromagnetic radiation detected by the photodiode at transition was not understood. During some flight tests early saturation of the device occurred, and the device failed to detect transition. Analyses have been performed to determine the source of the radiation producing the photodiode signal. Four proposed radiation sources were investigated: 1) radiation from the quartz window material, 2) radiation from the heat shield material bordering the quartz window, 3) radiative emissions from the gases within the boundary and shock layers, and 4) radiation from ablation products. The results of these analyses indicate that the most likely source of the radiation is blackbody emission from the heat shield material bordering the quartz window of the device. Good agreement between flight data and calculations based on this radiation source has been obtained. Analyses also indicate that the most probable source of the radiation causing early saturation is blackbody radiation from carbon particles that break away from the nosetip during the ablation process.
Ceramic Matrix Composite Applications in Advanced Liquid Fuel Rocket Engine Turbomachinery

Fiber-reinforced ceramic matrix composites have been identified with properties suitable for near term applications. Conceptual design studies indicate the feasibility of applying C/SiC, and subelements were manufactured that verify selected fabrication features and key material properties. Tests and inspection of these subelements confirmed their capabilities.
Triurethane-Protected Guanidines and Triflyldiurethane-Protected Guanidines: New Reagents for Guanidinylation Reactions

New guanidinylation reagents are reported. These reagents consist of N,N‘,N‘‘-tri-Boc-guanidine (1) and N,N‘,N‘‘-tri-Cbz-guanidine (2), which allow for the facile conversion of alcohols to substituted guanidines. A series of arginine analogues were synthesized via condensation of a primary or secondary alcohol with the guanidinylation reagents 1 or 2, under Mitsunobu conditions,1 to produce protected alkylated guanidines. In addition, an extended study of the previously reported reagents2 N,N‘-di-Boc-N‘‘-triflylguanidine (3) and N,N‘-di-Cbz-N‘‘-triflylguanidine (4) is presented. The triflyldiurethane-protected guanidine 3 was utilized to guanidinylate primary and secondary amines under mild conditions with high yield in both solution and on solid phase.
Expanding the National Flood Insurance Program to Cover Coastal Erosion Damage

This paper uses the results of a nationwide survey of coastal property owners to estimate the demand for insurance against erosion damage. The National Flood Insurance Program (NFIP) does not technically cover such damage, although in practice there is considerable uncertainty about this point. The ability to insure against such losses has implications for the choice of beach management strategies and for NFIP management. We find significant demand for insurance at prices in the range of current flood insurance premiums, although median willingness to pay appears to be less than the cost of providing such insurance.
Radiation effects at cryogenic temperatures in Si-JFET, GaAs MESFET, and MOSFET devices

Front-end electronics for liquid ionization chamber calorimetry at hadron collider experiments may be exposed to substantial levels of ionizing radiation and neutron fluences in a cryogenic environment. Measurements of devices built with rad-hard technologies have shown that devices able to operate in these conditions exist. Several families of devices (Si-JFETs, rad-hard MOSFETs, and GaAs MESFETs) have been irradiated and tested at a stable cryogenic temperature up to doses of 55 Mrad of ionizing radiation and up to neutron fluences of 4/spl times/10/sup 14/ n/cm/sup 2/. Radiation effects on DC characteristics and on noise will be presented.
A general analysis of propagation along multiple-layer superconducting stripline and microstrip transmission lines

A rigorous spectral-domain formulation for a superconducting stripline or microstrip transmission line with a multiple-layer dielectric substrate is presented. The formulation models the strip conductor as a surface current with an equivalent surface impedance, where the surface impedance is approximated in closed form when the strip is either much thinner or much thicker than a penetration depth. In either case the surface impedance is related to the complex conductivity of the material, which is calculated from a two-fluid model. Results are presented to show the slow-wave propagation and attenuation along both microstrip and stripline packages in a realistic multiple-layer configuration, which accounts for the field penetration into the superconducting ground planes. >