cssi/SciSciGPT-SciSciNet huggingface dataset:
A Sample Selection Approach to Censored Demand Systems

The multivariate sample selection model is extended to a nonlinear equation system with partial selection and applied to household meat consumption in China. Elasticity estimates differ from those obtained from conventional maximum likelihood and Tobit estimates. Chinese meat products are gross complements while net substitution also exists in some cases. The use of micro survey data has been popular in estimating consumer demand equations. Important features of microdata include censored dependent variables. Estimation procedures for censored consumer demand systems include the primal (Kuhn-Tucker) approach of Wales and Woodland (1983), dual (virtualprice) approach of Lee and Pitt (1986), and the Tobit system (Amemiya 1974) estimated by generalized maximum entropy (Golan, Perloff, and Shen 2001) and maximum simulated likelihood (Dong, Gould, and Kaiser 2004; Yen, Lin, and Smallwood 2003) procedures. Less efficient alternatives include the quasi-maximum likelihood estimator (Yen, Lin, and Smallwood 2003), the generalized method of moments estimator (Meyerhoefer, Ranney, and Sahn 2005), and a number of two-step estimators (Heien and Wessells 1990; Perali and Chavas 2000; Shonkwiler and Yen 1999). Yen (2005) recently proposed a maximum likelihood (ML) procedure for the multivariate sample selection model (MSSM), an extension of the bivariate sample selection model (Heckman 1979), which had motivated the procedures of Heien and Wessells (1990) and Shonkwiler and Yen (1999). The MSSM was developed in the context of linear equations and, in addition, is not strictly applicable for a partially selective equation system, viz.,
The standardized‐taper root canal preparation – Part 1. Concepts for variably tapered shaping instruments

Buchanan LS. The standardized-taper root canal preparation - Part 1. Concepts for variably tapered shaping instruments. International Endodontic Journal , 33 , 516-529, 2000. Aim To introduce the concept of variable taper instruments for predictable and ergonomic root canal preparation, and demonstrate the design features of Greater Taper files. Summary Optimal root canal shaping is difficult to practice and teach with traditional instruments. Instrument sequences are complex, with up to 18 instruments and 63 pro- cedural stages, providing almost limitless scope for poor results and iatrogenic error. In the first of six articles, Dr Buchanan describes the Variable Taper concept, which grew from such frustrations, and represents a new concept in file design. Milled from NiTi alloys in tapers of 0.06, 0.08, 0.10 and 0.12 mm mm -1 , with accessory files for wide canals, their design embodies the key shaping features of adequate coronal enlarge- ment, full deep shape, and predictable apical resistance form case after case. The ease and simplicity of their use is described, and enhanced cleaning and obturation outcomes discussed in relation to their unique design features. Key learning points • Canal preparation is difficult to practice and teach with traditional K-files and Gates Glidden drills. • Variable Taper files are designed to offer the optimal preparation features of adequate (not excessive) coronal enlargement, full deep shape, and apical resistance form in a simple instrument sequence. • Variable Taper technique is simple to master, and offers predictable cleaning and obturation outcomes, even in inexperienced hands.
In vivo time-resolved autofluorescence measurements on human skin

In this paper we present preliminary results obtained from fluorescence lifetime measurements on human skin using time-correlated single photon counting (TCSPC) techniques. Human skin was exposed to light from a pulsed LED of 700 ps pulse width at a wavelength of 375 nm and fluorescence decays were recorded at four different emission wavelengths (442, 460, 478 and 496 nm) using a photomultiplier tube (PMT) coupled to a monochromator. Measurements were carried out on the left and right palms of subjects recruited for the study after obtaining consent using a UCLA IRB approved consent form. The subjects recruited consisted of 18 males and 17 females with different skin complexions and ages ranging from 10 to 70 years. In addition, a set of experiments were also performed on various locations including the palm, the arm and the cheek of a Caucasian subject. The fluorescence decays thus obtained were fit to a three-exponential decay model in all cases and were approximately 0.4, 2.7 and 9.4 ns, respectively. The variations in these lifetimes with location, gender, skin complexion and age are studied. It is speculated that the shorter lifetimes correspond to free and bound NADH while the longer lifetime is due to AGE crosslinks.
Micro-machined heat pipes in silicon MCM substrates

Multichip modules (MCMs) containing power components need a substrate with excellent heat spreading capability both to avoid hot spots and to move dissipated heat toward the system heat sinks. Polycrystalline diamond is an excellent MCM heat spreading substrate but remains several orders of magnitude too expensive and somewhat more difficult to process than conventional mother-board materials. Today's power MCMs concentrate on moderately priced silicon wafers and aluminum nitride ceramic with their improved thermal conductivity and good thermal expansion match to power semiconductor components in comparison to traditional alumina and printed wiring board materials. However even silicon and AIN substrates are challenged by designers' thermal needs. We report on the fabrication of micro-heat pipes embedded in silicon MCM substrates (5/spl times/5 cm) by the use of micromachined capillary wick structures and hermetic micro-cavities. This passive microstructure results in more than a 5 times improvement in heat spreading capability of the silicon MCM substrate over a large range of power densities and operating temperatures. Thus diamond-like cooling is possible at silicon prices.
PREFERENTIAL FLOW INFLUENCES ON DRAINAGE OF SHALLOW SLOPING SOILS

The dramatic effect of flow through macropores and hardpan fissures on artificial drainage in shallow sloping soils is demonstrated. Implications of these preferential flow mechanisms on drainage design and water management are discussed. In designing drainage systems on these types of soils, more emphasis should be given to the characteristics of the hardpan.
Biobehavioral predictor variables of treatment outcome in patients with temporomandibular disorders

A biopsychosocial intervention approach has been found to be effective in the treatment of chronic medical conditions such as temporomandibular disorder (TMD). Recent research has begun to evaluate factors that may predict positive treatment response to such an approach. The present study was designed to assess the ability of two variables (a muscle disorder diagnosis and an elevation of Scale 3 on the MMPI-2) to predict treatment outcomes in a sample of chronic TMD patients. A total of 121 patients with chronic TMD were randomly assigned to one of five different treatment conditions: biofeedback, cognitive-behavioral skills training (CBST), combined CBST/biofeedback, no treatment/random control, or no treatment/not interested in treatment control. All patients were administered the standard Research Diagnostic Criteria (RDC) for TMD at pretreatment. They were reevaluated at posttreatment and 1 year after intervention. There were also four patient classification groups: dual presence of MMPI-2 Scale 3 elevation and an RDC muscle disorder diagnosis; MMPI-2 Scale 3 elevation and no RDC muscle disorder diagnosis; no MMPI-2 Scale 3 elevation and an RDC muscle disorder diagnosis; and no MMPI-2 Scale 3 elevation and no RDC muscle disorder diagnosis. Results revealed that the patient classification group variable significantly affected posttreatment pain levels. Such findings have important treatment implications and also suggest the significant biopsychosocial underpinnings of a chronic medical condition such as TMD.
Blow up Criterion for Nematic Liquid Crystal Flows

In this paper, we establish a blow up criterion for the short time classical solution of the nematic liquid crystal flow, a simplified version of Ericksen–Leslie system modeling the hydrodynamic evolution of nematic liquid crystals, in dimensions two and three. More precisely, 0 < T * < + ∞ is the maximal time interval iff (i) for n = 3, ; and (ii) for n = 2, .
Linked Without Linking: The Role of Mainland China’s Taiwanese Students in Cross-Strait Unification

Following the renewal of economic and social relations between Taiwan and Mainland China, economic and social integration between the two sides of the Taiwan Strait has led to an advanced state of interdependence. Scholars of integration have argued that economic integration has the potential to spill over into politics, catalyzing political unification. However, as unification has failed to appear, scholars have sought alternative frameworks for understanding the conditions necessary to facilitate unification. Drawing on the “linkage community” integration framework, which outlines a group of people with ties to both sides of the Taiwan Strait and the ability to influence policymakers as a primary variable for understanding the potential for unification, this paper examines the political activity of organizations for Taiwanese students at Mainland Chinese universities (taisheng). Based on data collected through informal interviews with Taiwanese students and officials conducted between October 2012 and August 2013, this paper presents information on the situation of Taiwanese students in Mainland China and argues that they have little potential to drive unification. It concludes that better understanding of the intersection of identity and interests in the cross-Strait context is essential to understanding the relationship between Taiwan and Mainland China and the unification of divided nations more generally.
Is trading behavior stable across contexts? Evidence from style and multi-style investors

In this paper we study priming of identity within the context of inherent vs. contextual financial decision making. We use a sample of individual trading accounts in equity-style funds taken from one fund family to test the hypothesis that trading styles are inherent vs. contextual. Our sample contains investors who invest either in a growth fund, a value fund, or both. We document behavioral differences between growth fund investors and value fund investors. We find that their trades depend on past returns in different ways: growth fund investors tend towards momentum trading and value fund investors tend towards contrarian trading. These differences may be due to inherent clientele characteristics, including beliefs about market prices, specific personality traits and cognitive strategies that cause them to self-select into one or the other style. We use a sample of investors that trade in both types of funds to test this proposition. Consistent with the contextual hypothesis, we find that investors who...
Perturbative Quantum Gravity and its Relation to Gauge Theory

In this review we describe a non-trivial relationship between perturbative gauge theory and gravity scattering amplitudes. At the semi-classical or tree-level, the scattering amplitudes of gravity theories in flat space can be expressed as a sum of products of well defined pieces of gauge theory amplitudes. These relationships were first discovered by Kawai, Lewellen, and Tye in the context of string theory, but hold more generally. In particular, they hold for standard Einstein gravity. A method based on D-dimensional unitarity can then be used to systematically construct all quantum loop corrections order-by-order in perturbation theory using as input the gravity tree amplitudes expressed in terms of gauge theory ones. More generally, the unitarity method provides a means for perturbatively quantizing massless gravity theories without the usual formal apparatus associated with the quantization of constrained systems. As one application, this method was used to demonstrate that maximally supersymmetric gravity is less divergent in the ultraviolet than previously thought.
Small Business and the Value of Community Financial Institutions

This paper examines whether community banks have a niche in the production of soft information when lending to small firms. A composite measure of soft information production is created from owner ratings of bank performance characteristics using survey data from a national sample of U.S. small firms. These characteristics capture some important aspects of soft information such as the bank’s knowledge of the owner’s business. This composite measure is related to the size of the owner’s primary bank, a measure of the intensity of market competition and proxies for the strength of banking relationships. After controlling for several sources of endogeneity, this composite measure is found to be significantly higher if the owner currently banks at a CFI and experiences less loan officer turnover.
NICMOS Imaging of the HR 4796A Circumstellar Disk

We report the first near-infrared (NIR) imaging of a circumstellar annular disk around the young (~8 Myr), Vega-like star HR 4796A. NICMOS coronagraph observations at 1.1 and 1.6 μm reveal a ringlike symmetrical structure that peaks in reflected intensity 105±002 (~70 AU) from the central A0 V star. The ring geometry, with an inclination of 731±12 and a major axis position angle of 268±06, is in good agreement with recent 12.5 and 20.8 μm observations of a truncated disk. The ring is resolved with a characteristic width of less than 026 (17 AU) and appears abruptly truncated at both the inner and outer edges. The region of the disk-plane inward of ~60 AU appears to be relatively free of scattering material. The integrated flux density of the part of the disk that is visible (greater than 065 from the star) is found to be 7.6±0.5 and 7.4±1.2 mJy at 1.1 and 1.6 μm, respectively. Correcting for the unseen area of the ring yields total flux densities of 12.8±1.0 and 12.5±2.0 mJy, respectively (Vega magnitudes equal to 12.92±0.08 and 12.35±0.18). The NIR luminosity ratio is evaluated from these results and ground-based photometry of the star. At these wavelengths, L(λ)/L(λ) is equal to 1.4±0.2×10 and 2.4±0.5×10, giving reasonable agreement between the stellar flux scattered in the NIR and that which is absorbed in the visible and reradiated in the thermal infrared. The somewhat red reflectance of the disk at these wavelengths implies a mean particle size in excess of several microns, which is larger than typical interstellar grains. The confinement of material to a relatively narrow annular zone implies dynamical constraints on the disk particles by one or more as yet unseen bodies.
Predictive business operations management

The ability to forecast metrics and performance indicators for business operations is crucial to proactively avoid abnormal situations, and to do effective business planning. However, expertise is typically required to drive each step of the prediction process. This is impractical when there are thousands of metrics to monitor. Fortunately, for business operations management, extreme accuracy is not required. It is usually enough to know when a metric is likely to go beyond the normal range of values. This gives opportunity for automation. In this paper, we present an engine that completely automates the prediction of metrics to support a better management of business operations.
An Improved Preparation of Highly Enantiomerically Enriched (R)-(+)-4-tert-Butyldimethylsiloxy-2-cyclopenten-1-one.

Abstract A convenient procedure for the preparation of the title compound of ⩾99% ee is presented as well as simple analytical methods for the determination of the optical purity of the product and intermediates in the sequence.
RELATIONS BETWEEN TWO COMMON TYPES OF RECTANGULAR TILINGS

Partitioning a multi-dimensional data set (array) into rectangular regions subject to some constraints (error measures) is an important problem arising from applications in parallel computing, databases, VLSI design, and so on. In this paper, we consider two most common types of partitioning used in practice: the Arbitrary partitioning and (p × p) partitioning, and study their relationships under three widely used error metrics: Max-Sum, Sum-SVar, and Sum-SLift.
Sliding and rolling constitutive theory for granular materials

By analyzing a microelement based on four spheres, equations governing the equilibrium of the microelement are developed. By examining these equations more closely, two primary mechanisms of failure of the microelements, one based on particle sliding and the other based on particle rolling, are identified. For each primary mechanism, two separate mechanisms, one based on collapse of the microelement in the vertical direction and the other based on collapse in the horizontal direction, are recognized. With the aid of these concepts, constitutive equations are developed for a two-dimensional assembly of granular particles. The assembly is considered to consist of four-sphere microelements. Taking the plastic strain to be a consequence of the collapse of some of the microelements, equations are developed for plastic strain. The formulation yields loading criteria and flow directions. With suitable hardening rules, it is shown that the microstructural model is capable of simulating most of the salient features of the stress-strain behavior of granular materials. In particular, the stress-dilatancy relation, taking into consideration phenomena of phase transformation, and critical state failure are simulated satisfactorily.
There Are No Racists Here: The Rise of Racial Extremism, When No One is Racist

At first glance hate murders appear wholly anachronistic in post-racial America. This Article suggests otherwise. The Article begins by analyzing the periodic expansions of the Supreme Court’s interpretation of the protection for racist expression in First Amendment doctrine. The Article then contextualizes the case law by providing evidence of how the First Amendment works on the ground in two separate areas —the enforcement of hate crime law and on university campuses that enact speech codes. In these areas, those using racist expression receive full protection for their beliefs. Part III describes social spaces—social media and employment where slurs and epithets may be used frequently. The final portion of the Article briefly explores two forms of unacknowledged racial violence—violence directed at minorities who move to white neighborhoods and extremist killings. Our inaccurate approach to bias-motivated crime and the culture of protection around racist expression, the Article concludes, leaves American society vulnerable to the danger created by racial extremists.
The factorization of discrete-process spectral matrices

A technique is presented for salving the discrete version of the multidimensional Wiener-Hopf equation by spectral factorization. This equation is derived to establish a need for spectral factorization and to determine the requirements of the factors of the spectral matrix. The method of factoring the spectral matrix of continuous systems, developed by Davis, is then extended to discrete systems. More specifically, a matrix H(z) must be found such that the matrix of the spectra of the input signals equals the product of H(z^{-1}) and H^{T}(z) . A technique for finding this matrix is presented. The nonanticipatoriness as well as the stability of the elements of H(z) and H^{-1}(z) must be and is guaranteed. It is then shown that the solution to the discrete Wiener-Hopf equation is unique.
Dynamic Adaptation of Liver Mitochondria to Chronic Alcohol Feeding in Mice BIOGENESIS, REMODELING, AND FUNCTIONAL ALTERATIONS

Liver mitochondria undergo dynamic alterations following chronic alcohol feeding to mice. Intragastric alcohol feeding to mice resulted in 1) increased state III respiration (109% compared with control) in isolated liver mitochondria, probably due to increased levels of complexes I, IV, and V being incorporated into the respiratory chain; 2) increased mitochondrial NAD+ and NADH levels (∼2-fold), with no change in the redox status; 3) alteration in mitochondrial morphology, with increased numbers of elongated mitochondria; and 4) enhanced mitochondrial biogenesis in the liver, which corresponded with an up-regulation of PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α). Oral alcohol feeding to mice, which is associated with less liver injury and steatosis, slightly enhanced respiration in isolated liver mitochondria (30.8% compared with control), lower than the striking increase caused by intragastric alcohol feeding. Mitochondrial respiration increased with both oral and intragastric alcohol feeding despite extensive N-acetylation of mitochondrial proteins. The alcohol-induced mitochondrial alterations are probably an adaptive response to enhance alcohol metabolism in the liver. Isolated liver mitochondria from alcohol-treated mice had a greater rate of acetaldehyde metabolism and respiration when treated with acetaldehyde than control. Aldehyde dehydrogenase-2 levels were unaltered in response to alcohol, suggesting that the greater acetaldehyde metabolism by isolated mitochondria from alcohol-treated mice was due to increased mitochondrial respiration that regenerated NAD+, the rate-limiting substrate in alcohol/acetaldehyde metabolism. Overall, our work suggests that mitochondrial plasticity in the liver may be an important adaptive response to the metabolic stress caused by alcohol intake and could potentially play a role in many other vital functions performed by the liver.
The spin state of iron in minerals of Earth's lower mantle

The spin state of Fe(II) and Fe(III) at temperatures and pressures typical for the Earth's lower mantle is discussed. We predict an extended high-spin to low-spin crossover region along the geotherm for Fe-dilute systems depending on crystal-field splitting, pairing energy, and cooperative interactions. In particular, spin transitions in ferromagnesium silicate perovskite and ferropericlase, the dominant lower mantle components, should occur in a wide temperature-pressure range. We also derive a gradual volume change associated with such transitions in the lower mantle. The gradual density changes and the wide spin crossover regions seem incompatible with lower mantle stratification resulting from a spin transition.
A Generalization of Automatic Sequences

Abstract We generalize the uniform tag sequences of Cobham, which arise as images of fixed points of k-uniform homomorphisms, to the case where the homomorphism ϕ is not necessarily uniform, but rather satisfies the analogue of an algebraic equation. We show that these sequences coincide with 1. (a) the class of sequences accepted by a finite automaton with “generalized digits” as input, and 2. (b) generalizations of the “locally catenative formula” of Rozenberg and Lindenmayer. Examples include the infinite Fibonacci word, which is generated as the fixed point of the homomorphism ϕ(a) = ab, ϕ(b) = a, and sequences of Rauzy and De Bruijn.
Regularity, Boosting, and Efficiently Simulating Every High-Entropy Distribution

We show that every bounded function g: {0,1}^n -≫ [0,1] admits an efficiently computable "simulator" function h: {0,1}^n-≫[0,1] such that every fixed polynomial size circuit has approximately the same correlation with g as with h. If g describes (up to scaling) a high min-entropy distribution D, then h can be used to efficiently sample a distribution D' of the same min-entropy that is indistinguishable from D by circuits of fixed polynomial size. We state and prove our result in a more abstract setting, in which we allow arbitrary finite domains instead of {0,1}^n, and arbitrary families of distinguishers, instead of fixed polynomial size circuits. Our result implies (a) the Weak Szemeredi Regularity Lemma of Frieze and Kannan (b) a constructive version of the Dense Model Theorem of Green, Tao and Ziegler with better quantitative parameters (polynomial rather than exponential in the distinguishing probability), and (c) the Impagliazzo Hardcore Set Lemma. It appears to be the general result underlying the known connections between "regularity" results in graph theory, "decomposition" results in additive combinatorics, and the Hardcore Lemma in complexity theory. We present two proofs of our result, one in the spirit of Nisan's proof of the Hardcore Lemma via duality of linear programming, and one similar to Impagliazzo's "boosting" proof. A third proof by iterative partitioning, which gives the complexity of the sampler to be exponential in the distinguishing probability, is also implicit in the Green-Tao-Ziegler proofs of the Dense Model Theorem.
A note on an NSFD scheme for a mathematical model of respiratory virus transmission

We construct a non-standard finite difference (NSFD) scheme for an SIRS mathematical model of respiratory virus transmission. This discretization is in full compliance with the NSFD methodology as formulated by Mickens. By use of an exact conservation law satisfied by the SIRS differential equations, we are able to determine the corresponding denominator function for the discrete first-order time derivatives. Our scheme is dynamically consistent with the SIRS differential equations, since the conservation laws are preserved. Furthermore, the scheme is shown to satisfy a positivity condition for its solutions for all values of the time step size.
HOW TO SYNCHRONIZE THE HEADS OF A MULTITAPE AUTOMATON

Given an n-tape automaton M with a one-way read-only head per tape and a right end marker $ on each tape, we say that M is aligned or 0-synchronized (or simply, synchronized) if for every n-tuple x = (x1,…, xn) that is accepted, there is a computation on x such that at any time during the computation, all heads, except those that have reached the end marker, are on the same position. When a head reaches the marker, it can no longer move. As usual, an n-tuple x = (x1,…, xn) is accepted if M eventually reaches the configuration where all n heads are on $ in an accepting state. In two recent papers, we looked at the problem of deciding, given an n-tape automaton of a given type, whether there exists an equivalent synchronized n-tape automaton of the same type. In this paper, we exhibit various classes of multitape automata which can(not) be converted to equivalent synchronized multitape automata.
Urban heat island

Abstract The phenomenon of an urban heat island was investigated by the use of Landsat/Thematic Mapper data sets collected over the metropolitan area of Washington, DC. By combining the derived spectral albedos and temperatures, surface energy composites of five surface categories were analysed. The results indicate that urban heating is attributable to a large excess in heat from the rapidly heating urban surfaces consisting of buildings, asphalt, bare-soil and short grasses. In summer, the symptoms of diurnal heating begin to appear by mid-morning and can be about 10°C warmer than nearby woodlands.
Hierarchical control of multiple resources in distributed real-time and embedded systems

Real-time and embedded systems have traditionally been designed for closed environments where operating conditions, input workloads, and resource availability are known a priori, and are subject to little or no change at runtime. There is increasing demand, however, for adaptive capabilities in distributed real-time and embedded (DRE) systems that execute in open environments where system operational conditions, input workload, and resource availability cannot be characterized accurately a priori. A challenging problem faced by researchers and developers of such systems is devising effective adaptive resource management strategies that can meet end-to-end quality of service (QoS) requirements of applications. To address key resource management challenges of open DRE systems, this paper presents the Hierarchical Distributed Resource-management Architecture (HiDRA), which provides adaptive resource management using control techniques that adapt to workload fluctuations and resource availability for both bandwidth and processor utilization simultaneously. This paper presents three contributions to research in adaptive resource management for DRE systems. First, we describe the structure and functionality of HiDRA. Second, we present an analytical model of HiDRA that formalizes its control-theoretic behavior and presents analytical assurance of system performance. Third, we evaluate the performance of HiDRA via experiments on a representative DRE system that performs real-time distributed target tracking. Our analytical and empirical results indicate that HiDRA yields predictable, stable, and efficient system performance, even in the face of changing workload and resource availability.
A Solution-Based Stall Delay Model for Horizontal-Axis Wind Turbines

This paper presents a solution-based stall delay model to predict rotational effects on horizontal-axis wind turbines. In contrast to conventional stall delay models that correct sectional airfoil data prior to the solution to account for three-dimensional and rotational effects, a novel approach is proposed that corrects sectional airfoil data during the solution process by investigating the spanwise circulation distribution along the blade and other solution-dependent parameters. The wind turbine performance analysis code XTurb-PSU iterates over modified sectional lift and drag data until a converged circulation distribution is obtained. Results obtained show good agreement with measured data along the NREL Phase VI and MEXICO rotor blades at low and high wind speeds.
Computation of the Generalized F Distribution

Exact expressions for the cumulative distribution function of a random variable of the form (α1X1+α2X2)/Y are given where X1, X2 and Y are independent chi-squared random variables. The expressions are applied to the detection of joint outliers and Hotelling's mis-specified T2 distribution.
A simple auction mechanism for the optimal allocation of the commons

Efficient regulation of the commons requires information about the regulated firms that is rarely available to regulators (e.g., cost of pollution abatement). Different mechanisms have been proposed for inducing firms to reveal their private information but for reasons I discuss in the paper, I find these mechanisms of limited use. I propose a much simpler mechanism that implements the first-best for any number of firms: a uniform price sealed-bid auction of an endogenous number of (transferable) licenses with a fraction of the auction revenues given back to firms. Paybacks, which decrease with the number of firms, are such that truth-telling is a dominant strategy regardless of whether firms behave non-cooperatively or collusively.
Characteristics of depth-sensing coplanar grid CdZnTe detectors

Abstract The latest depth-sensing coplanar grid CdZnTe detectors have been tested. Two of these have dimensions 1.5×1.5×1.0 cm3 and one is a cylindrical detector with 1.5 cm diameter and 1.0 cm length, all of them using the third-generation coplanar anode design. Energy resolutions of 2.0% and 2.4% FWHM at 662 keV γ-ray energies were obtained. Detector performance has been observed experimentally as a function of depth of the γ-ray interaction, and as a function of radial position near the anode surface. The measured results show the improvement of the third-generation anode design. Material uniformity of CdZnTe crystals manufactured by eV Products have been directly observed and compared on two 1.5×1.5×1.0 cm3 detectors.
Structure of Turbulent Shear Flows: A New Look

The problem of turbulent now continues to be an outstanding one in technology and in physics. Of the nine Dryden research lectures so far, four have been on some aspect of the turbulence problem. At meetings such as this one the turbulence problem is always the subject of some sessions and lurks in the background of many others; for example, separated now, combustion, jet noise, chemical lasers, atmospheric problems, etc. It is continually the subject of conferences, workshops and reviews. In his time Hugh Dryden wrote several reviews of turbulent now. In reading some of them again, one statement particularly relevant to the present lecture caught my attention: "-it is necessary to separate the random processes from the nonrandom processes. It is not yet fully clear what the random elements are in turbulent now." Neither is it fully clear what the nonrandom, orderly elements are, but some of them are beginning to be recognized and described. Generally the picture one has had of turbulence is of chaos and disorder, implicit in the name. Although it was known that organized motion could exist, superimposed on the background of "turbulence," for example, vortex shedding from a circular cylinder up to Reynolds numbers of 10^7, such examples were regarded as special cases closely tied to their particular geometric origins and not characteristic of "well-developed" turbulence. It was known that large structures are important in the development of turbulent shear flows and that these ought to possess some definable features. But even when the concept of a characteristic "big eddy" was explored, it was usually in the context of a statistical quantity. The earliest and most decisive attempts to define the form of such large eddies were made by Townsend and his students. In recent years it has become increasingly evident that turbulent shear flows do contain structures or eddies whose description is more deterministic than had been thought, possessing identifiable characteristics, existing for significant lifetimes, and producing recognizable and important events. More accurate descriptions of their properties, how they fit into the complete description of a turbulent flow, to what extent are they central to its development, and how they can be reconciled with the apparent chaos and disorder, are problems which are becoming of interest to an increasing number of researchers. It is the purpose of this lecture to describe some of these new developments. The discussion will draw largely on experiences from our own laboratory; it is not intended to be a complete survey. Other discussions of these ideas can be found in various recent publications.
Up-sampling and Natural Sample Value Computation for Digital Pulse Width Modulators

Digital pulse width modulation has been considered for high-fidelity and high-efficiency audio amplifiers for several years now. It has been shown that the distortion, can be reduced and the implementation of the system can be simplified if the switching frequency is much higher than the Nyquist rate of the modulating waveform. Hence, the input digital source is normally upsampled to a higher frequency. It was also proved that converting uniform samples to natural samples will decrease the harmonic distortion. Thus, in this paper, we examine a new approach that combines digital interpolation and natural sampling conversion. This approach uses poly-phase implementation of the digital interpolation filter and digital differentiators. We will show that the structure consists of an FIR-type linear stage and a nonlinear stage. Some spectral simulation results of a pulse width modulation system based on this approach will also be presented. Finally, we will discuss the improvement of the new approach over old algorithms.
High oxidation state alkylidene and alkylidyne complexes

Electron deficient high oxidation state early transition metal complexes that contain metal–carbon double or triple bonds and bulky supporting ligands have been found to be highly reactive catalysts for the alkene and alkyne metathesis reactions, respectively.
Coping with crises : why and how to protect employment and earnings

Events of the past two years are a reminder that crises are a recurring phenomenon with deep and often protracted impacts on labor markets. This paper examines the challenges inherent in crafting policy responses, with particular attention to developing countries. It focuses on the potential tradeoffs between offsetting adverse short-term impacts and preserving incentives for economic recovery and future growth, and between protecting the most vulnerable and compensating those most immediately impacted. It also highlights how policymakers room for maneuver is constrained in crisis times by deteriorating fiscal space, limited institutional capacity, and mounting political pressures. Based on empirical evidence from previous crises, the paper asserts that taking a myopic and reactive approach may be costly and counterproductive. Instead, it advocates a more comprehensive approach, designed to build institutions - such as automatic stabilizers and safety nets - that can deliver a coordinated and coherent policy package. This approach will make crises catalysts for institutional changes and long-run growth.
High energy density materials from azido cyclophosphazenes

Azido substituted cyclophosphazenes were prepared and their standard heats of formation were calculated based on experimentally determined heats of combustion.
Titan Launch Vehicle: Ground Test History

The major aerodynamic wind-tunnel tests that span the time frame from the early Titan I vehicle developed in 1955 to the most recent Titan-family vehicle, the Titan IV solid rocket motor upgrade, last tested in 1996, are summarized. These tests cover all aspects of single- and multibodied aerodynamics including nozzle hinge moments, staging, vehicle forces and moments, dynamic and static pressure distributions, and launch facility impingement pressures. Angle of attack/side slip covers the range primarily from 0 to 10 deg and, in select cases, from 50 to 90 deg. Principal emphasis is placed on the ground tests affecting the predicted aerodynamic environment of the Titan IV launch vehicle. Significant conclusions drawn from various three-body wind-tunnel tests are presented. Nomenclature C A = drag coefficient Cl = rolling moment coefficient Cm = bending moment coefficient in the pitch plane C N = normal force coefficient in the pitch plane Cn = bending moment coefficient in the yaw plane CY = side force coefficient in the yaw plane α = pitch plane angle of attack β = yaw plane angle of side slip I. Introduction A HISTORY of the major aerodynamic wind-tunnel tests that were conducted for the Titan family of launch vehicles is contained herein. Particular emphasis is given to those tests used to describe the aerodynamic environment of the most recent configuration, the Titan IV (TIV) type 1 [with solid rocket motor (SRM)] and type 2 [with solid rocket motor upgrade (SRMU)] launch vehicles. The description of the external aerodynamic environment acting on
Model Predictive Control Of A Parafoil And Payload System

A model predictive control strategy is developed for an autonomous parafoil and payload system. Since the technique requires a linear dynamic model of the system, a reduced state linear model based on a nonlinear 6 degree-of-freedom parafoil and payload model is established and validated. In order to use the reduced state linear model for model predictive control the desired trajectory in the x-y plane is mapped into a desired heading angle using Lagrange interpolating polynomials. Flight test results demonstrate that this model predictive control strategy is a natural and effective method of achieving trajectory tracking in a parafoil and payload system.
Synthesis of a novel dicycloproparene

Abstract A novel bridged dicycloproparene has been synthesized by treating the Diels-Alder adduct of 1-bromo-2-chlorocyclopropene and 2,3,5,6-tetramethylidene[2.2.2]bicyclooctane with potassium t-butoxide in tetrahydrofouran.
MODELS OF LITTLE HIGGS AND ELECTROWEAK PRECISION TESTS

The little Higgs idea is an alternative to supersymmetry as a solution to the gauge hierarchy problem. In this note, the author reviews various little Higgs models and their phenomenology with emphasis on the precision electroweak constraints in these models.
Retinex processing for automatic image enhancement

There has been a revivification of interest in the Retinex computation in the last six or seven years, especially in its use for image enhancement. In his last published concept (1986) for a Ret- inex computation, Land introduced a center/surround spatial form, which was inspired by the receptive field structures of neurophysi- ology. With this as our starting point, we develop the Retinex con- cept into a full scale automatic image enhancement algorithm—the multiscale Retinex with color restoration (MSRCR)—which com- bines color constancy with local contrast/lightness enhancement to transform digital images into renditions that approach the realism of direct scene observation. Recently, we have been exploring the fun- damental scientific questions raised by this form of image process- ing. 1. Is the linear representation of digital images adequate in visual terms in capturing the wide scene dynamic range? 2. Can visual quality measures using the MSRCR be developed? 3. Is there a canonical, i.e., statistically ideal, visual image? The answers to these questions can serve as the basis for automating visual as- sessment schemes, which, in turn, are a primitive first step in bring- ing visual intelligence to computers. © 2004 SPIE and IS&T.
“What's Wrong with Being Sexy?” Why Political Science Needs to Get Serious about Sexuality

From the infamous blue dress to lewd gesturing under an airport bathroom stall, the scandalous coupling of sex and politics generates a lot of buzz. Political pundits inevitably find themselves on the media frontlines, ruminating on the impact of a particular impropriety, its implications for the dishonored politician's career, and his or her ability to effectively perform his or her job. Comedians gather some of their greatest material from the collision of sex and politics. Their jokes and send-ups, however, are not limited to sexual scandal. Tina Fey's impersonation of Sarah Palin catapulted Saturday Night Live ( SNL ) to the top of the Nielson ratings map in 2008. The nation collectively busted a gut watching the mock “nonpartisan” television announcement featuring Sarah Palin (dressed in a brightly colored skirt suit and punctuating her statements with emotive winks or cutesy giggles) and Hillary Clinton (sporting a drab pantsuit and underscoring her statements with firm nods or a clenched fist pounding the podium) as they denounced the role that sexism played in the presidential campaign.
Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

Over the past decade and a half, homogenous gold catalysis has emerged as a diverse and rich field of research resulting in the continuous development of new methods for organic synthesis. The activation of alkynes towards nucleophilic attack by AuI and AuIII complexes is a well-established mode of reactivity and the gold-catalyzed hydration and hydroalkoxylation of alkynes are two of the more well-explored reaction pathways. Although these classes of reactions have seen continuous development since their initial reports, achieving regioselectivity persists as one of the most challenging issues for this chemistry. This article aims to draw attention to the general problem of regioselectivity in these reactions. A select set of examples is presented to highlight the challenges and survey some of the strategies employed to address this problem.
GaN-based high electron-mobility transistors for microwave and RF control applications

Heterojunction FETs or high electron-mobility transistors (HEMTs) based on Al/sub x/Ga/sub 1-x/N/GaN are studied for their use as control components for high-power microwave and RF control devices (switches, phase-shifters, etc.). A linear operation model was developed for these components so that optimum transistor geometry and operation parameters may be determined for their use in control applications. The model was verified with experimental data taken on test HEMT devices. It was experimentally established that the HEMT resistance is low for voltages of +1.0 V, and that the capacitive reactance increases for de gate voltages below the threshold voltage of approximately -1.5 V.
Transpapillary drainage has no added benefit on treatment outcomes in patients undergoing EUS-guided transmural drainage of pancreatic pseudocysts: a large multicenter study.

Background and Aims The need for transpapillary drainage (TPD) in patients undergoing transmural drainage (TMD) of pancreatic fluid collections (PFCs) remains unclear. The aims of this study were to compare treatment outcomes between patients with pancreatic pseudocysts undergoing TMD versus combined (TMD and TPD) drainage (CD) and to identify predictors of symptomatic and radiologic resolution. Methods This is a retrospective review of 375 consecutive patients with PFCs who underwent EUS-guided TMD from 2008 to 2014 at 15 academic centers in the United States. Main outcome measures included TMD and CD technical success, treatment outcomes (symptomatic and radiologic resolution) at follow-up, and predictors of treatment outcomes on logistic regression. Results A total of 375 patients underwent EUS-guided TMD of PFCs, of which 174 were pseudocysts. TMD alone was performed in 95 (55%) and CD in 79 (45%) pseudocysts. Technical success was as follows: TMD, 92 (97%) versus CD, 35 (44%) ( P = .0001). There was no difference in adverse events between the TMD (15%) and CD (14%) cohorts ( P = .23). Median long-term (LT) follow-up after transmural stent removal was 324 days (interquartile range, 72-493 days) for TMD and 201 days (interquartile range, 150-493 days) ( P = .37). There was no difference in LT symptomatic resolution (TMD, 69% vs CD, 62%; P = .61) or LT radiologic resolution (TMD, 71% vs CD, 67%; P = .79). TPD attempt was negatively associated with LT radiologic resolution of pseudocyst (odds ratio, 0.11; 95% confidence interval, 0.02-0.8; P = .03). Conclusions TPD has no benefit on treatment outcomes in patients undergoing EUS-guided TMD of pancreatic pseudocysts and negatively affects LT resolution of PFCs.
Hidden actions and preferences for timing of resolution of uncertainty

We study preferences for timing of resolution of objective uncertainty in a menuchoice model with two stages of information arrival. We characterize a general class of utility representations called hidden action representations, which interpret an intrinsic preference for timing of resolution of uncertainty as if an unobservable action is taken between the resolution of the two periods of information arrival. These representations permit a richer class of preferences for timing than was possible in the model of Kreps and Porteus (1978) by incorporating a preference for flexibility. Our model contains several special cases where this hidden action can be given a novel economic interpretation.
Copper-catalyzed diamination of unactivated alkenes with hydroxylamines

A copper-catalyzed regio- and stereoselective diamination of unactivated alkenes has been developed with O-acylhydroxylamines as electrophilic nitrogen sources and oxidants. This method provides the first example of metal-catalyzed alkene diamination for directly installing an electron-rich amino group and extends the diamination scope for the synthesis of diverse 1,2-diamines. It offers a rapid and efficient approach to construct a wide range of 1,2-diamines that are an important structural motif in organic synthesis, medicines, catalysts and ligands.
Coca Leaf Use in Southern Peru: Some Biosocial Aspects

The use of coca leaves in the Andean region has usually been condemned as a simple addiction to cocaine. This paper summarizes a series of studies in the southern Andes which consider the biological and economic motivations of the users. It is suggested that consumption of leaves is limited to avoid the undesirable effects of large doses of cocaine, while the smaller doses received are beneficial in certain aspects of the arduous life at high altitude. The persistence of the practice is viewed in terms of economics. It is concluded that coca plays a role in Andean life which is not related to simple addictive properties.