cssi/SciSciGPT-SciSciNet huggingface dataset:
Angular Synchronization by Eigenvectors and Semidefinite Programming

Abstract The angular synchronization problem is to obtain an accurate estimation (up to a constant additive phase) for a set of unknown angles θ 1 , … , θ n from m noisy measurements of their offsets θ i − θ j mod 2 π . Of particular interest is angle recovery in the presence of many outlier measurements that are uniformly distributed in [ 0 , 2 π ) and carry no information on the true offsets. We introduce an efficient recovery algorithm for the unknown angles from the top eigenvector of a specially designed Hermitian matrix. The eigenvector method is extremely stable and succeeds even when the number of outliers is exceedingly large. For example, we successfully estimate n = 400 angles from a full set of m = ( 400 2 ) offset measurements of which 90 % are outliers in less than a second on a commercial laptop. The performance of the method is analyzed using random matrix theory and information theory. We discuss the relation of the synchronization problem to the combinatorial optimization problem Max-2-Lin mod L and present a semidefinite relaxation for angle recovery, drawing similarities with the Goemans–Williamson algorithm for finding the maximum cut in a weighted graph. We present extensions of the eigenvector method to other synchronization problems that involve different group structures and their applications, such as the time synchronization problem in distributed networks and the surface reconstruction problems in computer vision and optics.
Dynamic analysis and experimental evaluation of delta modulators for field-oriented AC machine current regulators

Implementation of field-oriented control requires regulation of the temporal orientation of flux and current vectors in AC machines. The orientation is generally achieved via instantaneous control of stator current relative to either the measured flux or the indirectly estimated flux terms. In either case, the instantaneous control of current is critical. A novel approach for current regulation is presented, based on the use of a nonlinear discrete-time delta modulator which offers the potential for reduced parameter sensitivity and more accurate command tracking than either classical or state-space linear system controllers. A power electronic topology, the resonant DC link is ideally suited to implement this controller. Experimental data on a field-oriented induction machine controller using a resonant DC link inverter topology demonstrate the command tracking performance of this induction-machine current regulator. >
Causality Among Fed Cattle Market Variables: Directed Acyclic Graphs Analysis of Captive Supply

In quantitative research, direction of causality among the variables is often assumed without a rigorous test. In this study, the directed acyclic graph (DAG) method was used to illuminate causal relationships among fed cattle industry variables, in particular, it was shown that captive supply causes spot market price to change.
The transition to the metallic state in low density hydrogen.

Solid atomic hydrogen is one of the simplest systems to undergo a metal-insulator transition. Near the transition, the electronic degrees of freedom become strongly correlated and their description provides a difficult challenge for theoretical methods. As a result, the order and density of the phase transition are still subject to debate. In this work, we use diffusion quantum Monte Carlo to benchmark the transition between paramagnetic and anti-ferromagnetic body centered cubic atomic hydrogen in its ground state. We locate the density of the transition by computing the equation of state for these two phases and identify the phase transition order by computing the band gap near the phase transition. These benchmark results show that the phase transition is continuous and occurs at a Wigner-Seitz radius of rs = 2.27(3) a0. We compare our results to previously reported density functional theory, Hedin’s GW approximation, and dynamical mean field theory results.
Polar patterns in active fluids

We study the spatio-temporal dynamics of a model of polar active fluid in two dimensions. The system exhibits a transition from an isotropic to a polarized state as a function of density. The uniform polarized state is, however, unstable above a critical value of activity. Upon increasing activity, the active fluids displays increasingly complex patterns, including traveling bands, traveling vortices and chaotic behavior. The advection arising from the particles self-propulsion and unique to polar fluids yields qualitatively new behavior as compared to that obtained in active nematic, with traveling-wave structures. We show that the nonlinear hydrodynamic equations can be mapped onto a simplified diffusion-reaction-convection model, highlighting the connection between the complex dynamics of active system and that of excitable systems.
DYNAMIC TIME SERIES BINARY CHOICE

This paper considers dynamic time series binary choice models. It proves near epoch dependence and strong mixing for the dynamic binary choice model with correlated errors. Using this result, it shows in a time series setting the validity of the dynamic probit likelihood procedure when lags of the dependent binary variable are used as regressors, and it establishes the asymptotic validity of Horowitz’s smoothed maximum score estimation of dynamic binary choice models with lags of the dependent variable as regressors. For the semiparametric model, the latent error is explicitly allowed to be correlated. It turns out that no long-run variance estimator is needed for the validity of the smoothed maximum score procedure in the dynamic time series framework.
A survey of random processes with reinforcement

The models surveyed include generalized Polya urns, reinforced random walks, interacting urn models, and continuous reinforced processes. Emphasis is on methods and results, with sketches provided of some proofs. Applications are discussed in statistics, biology, economics and a number of other areas.
Access to cis-2,5-disubstituted iodovinyltetrahydrofurans via the cyclization of γ-silyloxyallenes using n-iodosuccinimide

Abstract Treatment of γ-( tert -butyldimethylsiloxy)- or γ-(trimethylsiloxy)allenes bearing various groups at the ether carbon with N-iodosuccinimide resulted in the formation of iodocyclization products, 1-iodo-1-(tetrahydrofuran-2′-yl)ethenes, in good yields and with high selectivity for the cis diastereomer.
A Frequency Decomposition of Approximation Errors in Stochastic Discount Factor Models

This article extends the work of Hansen and Jagannathan by showing how to decompose approximation errors in stochastic discount factor models by frequency. This decomposition is applied to a number of consumption-based discount factor models in order to investigate how well they fit at low frequencies. There is some evidence of improved fit at low frequencies, but only in models with high degrees of risk aversion. In models with low degrees of risk aversion, approximation errors at low frequencies are just as severe as those at high frequencies.
Concerning the occurrence pattern of flux transfer events on the dayside magnetopause

We present an analytical model for the magnetic field perturbations associated with flux transfer events (FTEs) on the dayside magnetopause as a function of the shear between the magnetosheath and magnetospheric magnetic fields and the ratio of their strengths. We assume that the events are produced by component reconnection along subsolar reconnection lines with tilts that depend upon the orientation of the interplanetary magnetic field (IMF), and show that the amplitudes of the perturbations generated during southward IMF greatly exceed those during northward IMF. As a result, even if the distributions of magnetic reconnection burst durations/event dimensions are identical during periods of northward and southward IMF orientation, events occurring for southward IMF orientations must predominate in surveys of dayside events. Two factors may restore the balance between events occurring for northward and southward IMF orientations on the flanks of the magnetosphere. Events generated on the dayside magnetopause during periods of southward IMF move poleward, while those generated during periods of northward IMF slip dawnward or duskward towards the flanks. Due to differing event and magnetospheric magnetic field orientations, events that produce weak signatures on the dayside magnetopause during intervals of northward IMF orientation may produce strong signatures on the flanks.
Soft physics in STAR

Abstract The STAR Experiment at RHIC is well-suited to making measurements of particle yields from relativistic nuclear collisions in the low transverse momentum, or “soft”, regime. We present preliminary results on measurements of π 0 , π − , π + , K − , K + , K s 0 , ϱ, K * 0 + K * 0 ¯ , f 0 , p , p ¯ , φ, λ, Λ ¯ , Ξ − , Ξ ¯ + , Ω − , and Ω ¯ + from the first two years of physics running at RHIC. An abundance of physics topics can be addressed by these measurements, some of which are discussed here along with the results.
Public vs. Private Equity

Many corporate executives view private equity as a last resort, as expensive capital that should be tapped only by companies that don't have access to presumably cheaper public equity. The reality of private equity, however, is more complex, and potentially quite rewarding, for both shareholders and management. This paper surveys some of the academic work on the costs and benefits of public vs. private equity, contrasting the private equity investment process with its public counterpart and exploring how such a process may add value. The importance of public equity, particularly for very large companies and growth companies with large capital requirements, is indisputable. But as investment bankers and other practitioners have noted, under certain circumstances the public markets effectively become “closed” to some public companies. Moreover, the cost of equity raised in public markets involves much more than the direct costs of underwriters, attorneys, and accountants. Some indication of the indirect costs is provided by the market's typically negative reaction to announcements of seasoned equity offerings. Although the negative reaction averages about 3%, in some cases stock prices drop by as much as 10%, thereby diluting the value of existing stockholders. Most academics attribute this reaction to the informational disadvantage of public stockholders. Private equity is designed in large part to overcome this information problem by replacing the monitoring performed by the typical public company board with the oversight of better informed and more highly motivated owners. A growing body of academic research suggests that private equity investors add value to the companies they invest in, and that the best investors are consistently effective in so doing. What's more, even public companies that tap private equity seem to benefit. As the author found in his own research on PIPES (Private Investment in Public Equity Securities) transactions, even though such securities are issued to private equity investors at a discount to the prevailing market price, the average market response to the announcement of such transactions is a positive 10%. In short, the participation of private equity investors is perceived to create value, and some of this value is shared with the rest of the market.
Improved method for parameter estimation of complex sinusoids in noise

Using, respectively, the theory of resultants/subresultants (inner determinants) and the one-to-one correspondence between reactance functions and Hurwitz polynomials, a set of necessary conditions and also another set of necessary and sufficient conditions, which involve nonlinear constraints on the polynomial coefficients, are obtained for all the roots of the polynomial to lie on the unit circle and be distinct from each other. The results have potentials for leading to improvements over previous methods for estimating parameters of sinusoids in noise where the constraints imposed provided only necessary conditions which were linear in the polynomial coefficients. >
First Structurally Characterized Palladium(II)-Substituted Polyoxoanion: [Cs2Na(H2O)10Pd3(α-SbIIIW9O33)2]9-

The palladium-substituted tungstoantimonate(III) [Cs2Na(H2O)10Pd3(α-SbW9O33)2]9- (1) has been synthesized and characterized by IR, elemental analysis, and electrochemistry. Single-crystal X-ray analysis was carried out on Cs3KNa5[Cs2Na(H2O)10Pd3(SbW9O33)2]·16.5H2O, which crystallizes in the monoclinic system, space group P21/m, with a = 13.3963(13) A, b = 19.5970(19) A, c = 18.1723(17) A, β = 100.416(2)°, and Z = 2. Polyanion 1 represents the first structurally characterized palladium(II)-substituted polyoxometalate. The title polyoxoanion consists of two (α-SbIIIW9O33) Keggin moieties linked via three Pd2+ ions leading to a sandwich-type structure. The palladium centers are equivalent, and they are coordinated in a square-planar fashion. The central belt of 1 contains also one sodium and two cesium ions which reduces the symmetry of the polyanion to C2v. Polyanion 1 was synthesized in good yield by reaction of Pd(CH3COO)2 with Na9[SbW9O33] in aqueous acidic medium (pH 4.8). A cyclic voltammetry study of ...
Graphical potential games

We study the class of potential games that are also graphical games with respect to a given graph G of connections between the players. We show that, up to strategic equivalence, this class of games can be identified with the set of Markov random fields on G. From this characterization, and from the Hammersley–Clifford theorem, it follows that the potentials of such games can be decomposed into local potentials.
A device model for the tandem junction solar cell

A conceptual device model has been developed to explain operation of the Tandem Junction Cell (TJC) when back contacts only are used. Operation and parameters of the cell are explained by transistor action. Experimental observations are presented which confirm that current is collected for carrier generation in the front uncontacted n+region. The model should be useful as a guideline to optimize the TJC by application of transistor design principles.
FASCIOCUTANEOUS BLOOD SUPPLY IN BELOW-KNEE AMPUTATION

Skin cover after below-knee amputation has been extensively discussed. We describe the flaps which are commonly used and discuss their vascular basis in the context of the current knowledge of the fasciocutaneous system. An understanding of this vascular system will enable surgeons to plan and shape flaps for surgical exposure and coverage.
The 'Out of Africa' Hypothesis, Human Genetic Diversity, and Comparative Economic Development

This research advances and empirically establishes the hypothesis that, in the course of the prehistoric exodus of Homo sapiens out of Africa, variation in migratory distance to various settlements across the globe affected genetic diversity and has had a persistent humpshaped effect on comparative economic development, reflecting the trade-off between the beneficial and the detrimental effects of diversity on productivity. While the low diversity of Native American populations and the high diversity of African populations have been detrimental for the development of these regions, the intermediate levels of diversity associated with European and Asian populations have been conducive for development. (JEL N10, N30, N50, O10, O50, Z10) Prevailing hypotheses of comparative economic development highlight various determinants of the remarkable inequality in income per capita across the globe. The significance of geographical, institutional, and cultural factors, human capital, ethnolinguistic fractionalization, colonialism, and globalization has been at the heart of a debate concerning the genesis of the astounding transformation in the pattern of comparative development over the past few centuries. While early research focused on the proximate forces that contributed to the divergence in living
Bismuth compounds in organic synthesis. A one-pot synthesis of homoallyl ethers and homoallyl acetates from aldehydes catalyzed by bismuth triflate.

Three one-pot methods for the conversion of aldehydes to homoallyl ethers catalyzed by Bi(OTf)3·xH2O (1 < x < 4) have been developed. The one-pot synthesis of homoallyl ethers can be achieved either by in situ generation of the acetal followed by its reaction with allyltrialkylsilane or by a three-component synthesis in which the aldehyde, trimethylorthoformate or an alkoxytrimethylsilane and allyltrimethylsilane are mixed together in the presence of bismuth triflate (0.1−1.0 mol %). In addition, a three-component synthesis of homoallyl acetates, which is achieved by reacting the aldehyde, acetic anhydride, and allyltrimethylsilane in the presence of bismuth triflate (3.0−5.0 mol %), has been developed. The use of a relatively nontoxic, easy to handle, and inexpensive catalyst adds to the versatility of these methods.
Emerging infectious disease surveillance in Southeast Asia: Cambodia, Indonesia, and the Naval Area Medical Research Unit 2

Abstract Emerging infectious diseases (EIDs) pose international security threats. What cultural, political, and economic challenges stand in the way of setting up EID Surveillance infrastructure? Are there general principles that might guide engagement with developing countries and support such infrastructure? Using the US Naval Area Medical Research Unit 2 as a common denominator, this study compares barriers to EID surveillance in Cambodia and Indonesia and presents key factors that constrain disease surveillance systems. As extensive interviews revealed, low levels of development in general are the main impediments to building EID surveillance infrastructure and are perhaps beyond the scope of health and scientific agencies at this point. Ultimately, political economy matters and promoting greater understanding of these issues is a critical first step in mitigating negative outcomes.
Maximum likelihood angle estimation for signals with known waveforms

Maximum-likelihood estimation (MLE) of the arrival angles of narrowband plane waves when one or all signals have known waveforms is considered. Computationally efficient and rapidly converging algorithms that iteratively maximize the likelihood functions are presented. Cramer-Rao bounds for these estimators are obtained. The conditions under which incorporating knowledge of one or all of the signal waveforms in the estimators improves the accuracy of the angle estimates are described. >
Nickel-catalyzed decarboxylative arylation of azoles with perfluoro- and nitrobenzoates

This manuscript describes a Ni-catalyzed method for the direct arylation of azoles using benzoates. Perfluorophenyl and 2-nitrobenzoates participate in these reactions to afford the corresponding products in modest to good yields. The efficiency of the arylations with perfluorobenzoates is highly dependent on both the degree and position of fluorine atoms in the benzoates.
The Transport of Oxygen, Glucose, Carbon Dioxide and Lactic Acid in the Human Brain : Mathematical Models

Mathematical models of the transport of oxygen, glucose, carbon dioxide and lactic acid in the human brain have been developed and solved for both steady-state and dynamic cases which include normal conditions, arterial and venous hypoxia, reduced flow and hematocrit, hypocapnia, reduced glucose and transient arterial upsets. Results indicate that local concentration deficits of oxygen and/or glucose and excesses of lactic acid can exist within the system described by the models and therefore possibly could exist in the tissues of the human brain under similar conditions.
Elevated East Antarctic outlet glaciers during warmer-than-present climates in southern Victoria Land

Abstract We document Plio-Pleistocene changes in the level of Taylor Glacier, an outlet glacier in southern Victoria Land that drains Taylor Dome on the periphery of the East Antarctic Ice Sheet (EAIS). Chronologic control comes from 3He cosmogenic-nuclide analyses of 27 boulders sampled from drifts and moraines in Kennar Valley, a small hanging valley that opens onto a peripheral lobe of Taylor Glacier in the Quartermain Mountains. Assuming a constant boulder-erosion rate of 10 cm Myr−1, our preferred age model spans the last 3.1 Myr and calls for stepped ice recession from a local highstand ~ 200 m above the present base of Taylor Glacier at the mouth of Kennar Valley. The texture and sedimentology of all mapped moraines and drifts indicate deposition from cold-based ice, analogous with the modern Taylor Glacier at the mouth of Kennar Valley. The Kennar Valley glacial record shows an uncharacteristic relationship with average global temperatures, exhibiting higher-than-present ice levels during globally warm periods, including the Pliocene climatic optimum (~ 3.1 Ma) and Marine Oxygen Isotope Stage (MIS) 31 (~ 1.07 Ma). The Kennar Valley record also suggests that the rate of ice-surface lowering accelerated after the mid-Pleistocene transition at ~ 0.9 Ma. Correlation of our moraine record with published reports for fluctuations of Taylor Glacier elsewhere in the Quartermain Mountains, and with a dated moraine record from Ferrar Glacier (a second outlet for Taylor Dome), reveals similar ice-surface changes, highlighting minor, but widespread ice recession in southern Victoria Land since the mid- to late-Pliocene. Our record for minimal variability in the East Antarctic Ice Sheet contrasts with recent data from nearby marine cores that call for dynamic fluctuations in the volume of grounded ice in the Ross Embayment, and significant reduction of the West Antarctic Ice Sheet (WAIS) during warmer-than-present intervals. Taken together, these records from the Ross Embayment call for considerable variation in the response of marine-based West Antarctic ice and terrestrial East Antarctic outlet glaciers during Plio-Pleistocene time.
A differential approach to inference in Bayesian networks

We present a new approach to inference in Bayesian networks, which is based on representing the network using a polynomial and then retrieving answers to probabilistic queries by evaluating and differentiating the polynomial. The network polynomial itself is exponential in size, but we show how it can be computed efficiently using an arithmetic circuit that can be evaluated and differentiated in time and space linear in the circuit size. The proposed framework for inference subsumes one of the most influential methods for inference in Bayesian networks, known as the tree-clustering or jointree method, which provides a deeper understanding of this classical method and lifts its desirable characteristics to a much more general setting. We discuss some theoretical and practical implications of this subsumption.
The ribosome as a table-driven convolutional decoder for the Escherichia coli K-12 translation initiation system

Redundancy occurs naturally within RNA and DNA sequences. The existence of tandem repeats, and sequences such as the Shine-Dalgarno sequence, the Pribnow box and the TATA box, leads the authors to believe that cellular communication systems use some method of coding to recognize valid information regions within a nucleotide sequence and correct for "transmission" errors such as mutations. Here, the authors use principles of convolutional coding theory to analyse the translation initiation process. The principle hypothesis is that the messenger RNA (mRNA) sequence can be viewed as a noisy, convolutionary encoded signal. The ribosome is functionally paralleled to a table-driven convolutional decoder. The 16s ribosomal RNA (rRNA) sequence is used to form decoding masks for table-driven decoding. The results of applying this method to Escherichia coli K-12 strain MG1655 are presented.
Rigidity of SU(2, 2|2)-symmetric solutions in Type IIB

We investigate the existence of half-BPS solutions in Type IIB supergravity which are invariant under the superalgebra SU(2, 2|2) realized on either AdS5 × S2 × S1 or AdS5 × S3 warped over a Riemann surface Σ with boundary. We prove that, in both cases, the only solution is AdS5 × S5 itself. We argue that this result provides evidence for the non-existence of fully back-reacted intersecting D3/D7 branes with either AdS5 × S2 × S1 × Σ or AdS5 × S3 × Σ near-horizon limits.
Economic Growth under Globalization: Evidence from Panel Data Analysis

It has been controversial among economists about the impacts of globalization on growth, and the debate over the issue has intensified in recent years. In this study, we employ reliable panel data and an empirical growth model derived from production theory to investigate the effects of globalization on economic growth. The estimation results strongly suggest that economic globalization has a significant positive effect on economic growth for all countries. However, China and India would gain the most, followed by developed countries, and other developing countries would gain the least. Other important determinants of economic growth include capital, human capital, and technology.
Superconducting magnet design for Fixed-Field Alternating-Gradient (FFAG) accelerator

The FFAG accelerator requires static fields that increase with radius along the accelerator midplane according to B=B/sub 0/(R/R/sub 0/)/sup 13.4/. The field is generated by equally spaced magnets around the circumference and varies from a maximum of 4.1 T to a minimum of -1.9 T. The general coil design employs cryostable magnets wound with aluminum stabilized superconductor. Each magnet has resistive pole face windings outside of the cryostat to allow for field fine tuning after construction. A set of iron-free coil windings generate the required field distribution. >
Customized Online Promotions: Moderating Effect Of Promotion Type On Deal Value, Perceived Fairness, And Purchase Intent

This paper investigated whether consumers differ in their perceptions of deal value, fairness and purchase intentions when presented with individually targeted (or customized) promotions versus universal promotions offered to all consumers at online retail websites. It was found that customized offers lead to significantly higher purchase intent compared to universal offers. Perceived fairness differed significantly across promotion types (free shipping, $ off and temporary reduced price) based on whether they were customized to the consumer or offered universally. Implications for designing customized online promotions are offered.
The Seven Sins of Consumer Psychology

Consumer psychology faces serious issues of internal and external relevance. Most of these issues originate in seven fundamental problems with the way consumer psychologists plan and conduct their research—problems that could be called “the seven sins of consumer psychology.” These seven “sins” are (1) a narrow conception of the scope of consumer behavior research; (2) adoption of a narrow set of theoretical lenses; (3) adherence to a narrow epistemology of consumer research; (4) an almost exclusive emphasis on psychological processes as opposed to psychological content; (5) a strong tendency to overgeneralize from finite empirical results, both as authors and as reviewers; (6) a predisposition to design studies based on methodological convenience rather than on substantive considerations; and (7) a pervasive confusion between “theories of studies” and studies of theories. Addressing these problems (“atoning for these sins”) would greatly enhance the relevance of the field. However, this may require a substantial rebalancing of the field's incentives to reward actual research impact rather than sheer number of publications in major journals.
An Efficient and Practical System for the Catalytic Oxidation of Alcohols, Aldehydes, and α,β-Unsaturated Carboxylic Acids

Upon exposure to commercial bleach (∼5% aqueous sodium hypochlorite), nickel(II) chloride or nickel(II) acetate is transformed quantitatively into an insoluble nickel species, nickel oxide hydroxide. This material consists of high surface area nanoparticles (ca. 4 nm) and is a useful heterogeneous catalyst for the oxidation of many organic compounds. The oxidation of primary alcohols to carboxylic acids, secondary alcohols to ketones, aldehydes to carboxylic acids, and α,β-unsaturated carboxylic acids to epoxy acids is demonstrated using 2.5 mol % of nickel catalyst and commercial bleach as the terminal oxidant. We demonstrate the controlled and selective oxidation of several organic substrates using this system affording 70−95% isolated yields and 90−100% purity. In most cases, the oxidations can be performed without an organic solvent, making this approach attractive as a “greener” alternative to conventional oxidations.
RURAL FINANCE INSTITUTIONS, MARKETS AND POLICIES IN AFRICA

We identify three types of obstacles (missing institutions) that limit the process of financial deepening in rural financial markets. Each of these obstacles contributes to a continuing and common dilemma in developing countries - the lack of long-term finance. In Africa, as in most developing regions, there is need to develop a more consistent strategy for improving access to term finance in agriculture and rural areas. Although some examples of term financing can be found in African agriculture, the general lack of term financing in rural areas can be linked to the lack of general policy measures to enhance the environment for long-term financing, weak effective demand for rural and agricultural investment financing, and inadequate capacity of lenders to provide long-term finance to those clientele.
Pthreads for Dynamic and Irregular Parallelism

High performance applications on shared memory machines have typically been written in a coarse grained style, with one heavyweight thread per processor. In comparison, programming with a large number of lightweight, parallel threads has several advantages, including simpler coding for programs with irregular and dynamic parallelism, and better adaptability to a changing number of processors. The programmer can express a new thread to execute each individual parallel task; the implementation dynamically creates and schedules these threads onto the processors, and effectively balances the load. However, unless the threads scheduler is designed carefully, the parallel program may suffer poor space and time performance. In this paper, we study the performance of a native, lightweight POSIX threads (Pthreads) library on a shared memory machine running Solaris; to our knowledge, the Solaris library is one of the most efficient user-level implementations of the Pthreads standard available today. To evaluate this Pthreads implementation, we use a set of parallel programs that dynamically create a large number of threads. The programs include dense and sparse matrix multiplies, two N-body codes, a data classifier, a volume rendering benchmark, and a high performance FFT package. We find the existing threads scheduler to be unsuitable for executing such programs. We show how simple modifications to the Pthreads scheduler can result in significantly improved space and time performance for the programs; the modified scheduler results in as much as 44% less running time and 63% less memory requirement compared to the original Pthreads implementation. Our results indicate that, provided we use a good scheduler, the rich functionality and standard API of Pthreads can be combined with the advantages of dynamic, lightweight threads to result in high performance.
Rate and power allocation under the pairwise distributed source coding constraint

We consider the problem of rate and power allocation for a sensor network under the pairwise distributed source coding constraint. For noiseless source-terminal channels, we show that the minimum sum rate assignment can be found by finding a minimum weight arborescence in an appropriately defined directed graph. For orthogonal noisy source-terminal channels, the minimum sum power allocation can be found by finding a minimum weight matching forest in a mixed graph. Numerical results are presented for both cases showing that our solutions always outperform previously proposed solutions. The gains are considerable when source correlations are high.
Suffix arrays: a new method for on-line string searches

A new and conceptually simple data structure, called a suffix array, for on-line string searches is introduced in this paper. Constructing and querying suffix arrays is reduced to a sort and search paradigm that employs novel algorithms. The main advantage of suffix arrays over suffix trees is that, in practice, they use three to five times less space. From a complexity standpoint, suffix arrays permit on-line string searches of the type, “Is W a substring of A?” to be answered in time $O(P + \log N)$, where P is the length of W and N is the length of A, which is competitive with (and in some cases slightly better than) suffix trees. The only drawback is that in those instances where the underlying alphabet is finite and small, suffix trees can be constructed in $O(N)$ time in the worst case, versus $O(N\log N)$ time for suffix arrays. However, an augmented algorithm is given that, regardless of the alphabet size, constructs suffix arrays in $O(N)$expected time, albeit with lesser space efficiency. It is ...
Algorithms for CVaR Optimization in MDPs

In many sequential decision-making problems we may want to manage risk by minimizing some measure of variability in costs in addition to minimizing a standard criterion. Conditional value-at-risk (CVaR) is a relatively new risk measure that addresses some of the shortcomings of the well-known variance-related risk measures, and because of its computational efficiencies has gained popularity in finance and operations research. In this paper, we consider the mean-CVaR optimization problem in MDPs. We first derive a formula for computing the gradient of this risk-sensitive objective function. We then devise policy gradient and actor-critic algorithms that each uses a specific method to estimate this gradient and updates the policy parameters in the descent direction. We establish the convergence of our algorithms to locally risk-sensitive optimal policies. Finally, we demonstrate the usefulness of our algorithms in an optimal stopping problem.
Continual Corporate Entrepreneurial Search for Long-Term Growth

This paper examines how established firms conduct continual entrepreneurial search for possibilities for long-term growth. Drawing on comprehensive internal documents of the DuPont Company over a 20-year period, we develop a search process that is a departure from frequent depictions of search as local or random. Longitudinal field data show that corporate entrepreneurs follow a moving, anchored search for growth possibilities. Employing this framework as lens, we develop propositions. We find that corporate entrepreneurs are more likely to conduct search in new domains following events that cause them to expect future performance to change significantly and lastingly. This is in contrast to the literature that has typically modeled the initiation of search as a response to poor past performance. Because new domains are unexplored territories for corporate entrepreneurs, they utilize transitional levers that they perceive will facilitate the move from existing domains to new ones. These perceived transitional levers, however, typically prove inaccurate or incomplete. Content within domains is searched using anchors whose locations and numbers change. The combination of search process and content searched influences the particular growth possibilities discovered and created. Search and pursuit of growth possibilities is accompanied by the creation of new knowledge and new capabilities.
Towards observing the intercommutation of flux tubes in superconductors

Abstract We propose a simple experiment to investigate the intercommutation of flux tubes in type II superconductors. Using this method the intercommutation of strings can be observed directly and the dependence of intercommutation on the initial angle of crossing of strings can also be analyzed.
Electrically Driven Photonic Crystal Nanocavity Devices

Interest in photonic crystal nanocavities is fueled by advances in device performance, particularly in the development of low-threshold laser sources. Effective electrical control of high-performance photonic crystal lasers has thus far remained elusive due to the complexities associated with current injection into cavities. A fabrication procedure for electrically pumping photonic crystal membrane devices using a lateral p-i-n junction has been developed and is described in this study. We have demonstrated electrically pumped lasing in our junctions with a threshold of 181 nA at 50 K-the lowest threshold ever demonstrated in an electrically pumped laser. At room temperature, we find that our devices behave as single-mode light-emitting diodes (LEDs), which when directly modulated, have an ultrafast electrical response up to 10 GHz corresponding to less than 1 fJ/bit energy operation-the lowest for any optical transmitter. In addition, we have demonstrated electrical pumping of photonic crystal nanobeam LEDs, and have built fiber taper coupled electro-optic modulators. Fiber-coupled photodetectors based on two-photon absorption are also demonstrated as well as multiply integrated components that can be independently electrically controlled. The presented electrical injection platform is a major step forward in providing practical low power and integrable devices for on-chip photonics.
Can immigrants help women “have it all”? Immigrant labor and women’s joint fertility and labor supply decisions

This paper explores how inflows of low-skilled immigrants impact the tradeoffs women face when making joint fertility and labor supply decisions. I find increases in fertility and decreases in labor force participation rates among high-skilled US-born women in cities that have experienced larger immigrant inflows. Most interestingly, these changes have been accompanied by decreases in the strength of the negative correlation between childbearing and labor force participation, an often-used measure of the difficulty with which women combine motherhood and labor market work. Using a structured statistical model, I show that the immigrant-induced attenuation of this negative correlation can explain about 24% of the immigrant-induced increases in the joint likelihood of childbearing and labor force participation in the US between the years 1980 and 2000. JEL codes D10, F22, J13, J22, R23
IMA Resource Allocation process

IMA Resource Allocation process needs to be thought out prior to beginning of an IMA development. The aircraft functions that are being hosted on the IMA architecture will need to have early system engineering/modeling done. Based on this early work, allocations/budgets need to be determined and the IMA system architecture modeled to determine the right amount of IMA shared resources that will need to be available.
Highly enantio- and diastereoselective one-pot synthesis of acyclic epoxy alcohols and allylic epoxy alcohols

In this report, we outline a highly enantio- and diastereoselective one-pot method for the efficient synthesis of synthetically useful acyclic epoxy alcohols and allylic epoxy alcohols. Our method takes advantage of a highly enantioselective C-C bond-forming reaction to set the initial chirality. The resulting allylic zinc alkoxide intermediate is then epoxidized in situ using either dioxygen or TBHP in the presence of a titanium tetraalkoxide. Epoxy alcohols with up to three contiguous stereocenters are formed in one pot with excellent enantio- and diastereoselectivity. In cases where the zinc alkoxide intermediates contain two different allylic olefins, the more electron-rich double bond is chemoselectively epoxidized to afford an allylic epoxy alcohol. This method represents a highly efficient, stereoselective, and chemoselective approach to the synthesis of a wide range of useful epoxy alcohol and allylic epoxy alcohol products that were previously difficult to access.
Selective pressures on genomes in molecular evolution

We describe the evolution of macromolecules as an information transmission process and apply tools from Shannon information theory to it. This allows us to isolate three independent, competing selective pressures that we term compression, transmission, and neutrality selection. The first two affect genome length: the pressure to conserve resources by compressing the code, and the pressure to acquire additional information that improves the channel, increasing the rate of information transmission into each offspring. Noisy transmission channels (replication with mutations) give rise to a third pressure that acts on the actual encoding of information; it maximizes the fraction of mutations that are neutral with respect to the phenotype. This neutrality selection has important implications for the evolution of evolvability. We demonstrate each selective pressure in experiments with digital organisms.
Predicting e-services adoption: a perceived risk facets perspective

Internet-delivered e-services are increasingly being made available to consumers; however, little is known about how consumers evaluate them for potential adoption. Past Technology Adoption Research has focused primarily on the positive utility gains attributable to system adoption. This research extends that approach to include measures of negative utility (potential losses) attributable to e-service adoption. Drawing from Perceived Risk Theory, specific risk facets were operationalized, integrated, and empirically tested within the Technology Acceptance Model resulting in a proposed e-services adoption model. Results indicated that e-services adoption is adversely affected primarily by performance-based risk perceptions, and perceived ease of use of the e-service reduced these risk concerns. Implications of integrating perceived risk into the proposed e-services adoption model are discussed.
Economic Inequality and Democratic Political Engagement

What effect, if any, does the extent of economic inequality in a country have upon the political engagement of its citizens? This study examines this question using data from multiple cross-national surveys of the advanced industrial democracies. It tests the theory that greater inequality increases the relative power of the wealthy to shape politics in their own favor against rival arguments that focus on the effects of inequality on citizens' objective interests or the resources they have available for political engagement. The analysis demonstrates that higher levels of income inequality powerfully depress political interest, the frequency of political discussion, and participation in elections among all but the most affluent citizens, providing compelling evidence that greater economic inequality yields greater political inequality.
The Stable Manifold Theorem for Stochastic Differential Equations

type equations are treated. Starting with the existence of a stochastic flow for a SDE, we introduce the notion of a hyperbolic stationary trajectory. We prove the existence of invariant random stable and unstable manifolds in the neighborhood of the hyperbolic stationary solution. For Stratonovich SDEs, the stable and unstable manifolds are dynamically characterized using forward and backward solutions of the anticipating SDE. The proof of the stable manifold theorem is based on Ruelle–Oseledec multiplicative ergodic theory.
Electronic Response and Bandstructure Modulation of Carbon Nanotubes in a Transverse Electrical Field

The electronic properties of carbon nanotubes (NTs) in a uniform transverse field are investigated within a single orbital tight-binding (TB) model. For doped nanotubes, the dielectric function is found to depend not only on symmetry of the tube, but also on radius and Fermi level position. Band gap opening/closing is predicted for zigzag tubes, while it is found that armchair tubes always remain metallic, which is explained by the symmetry in their configuration. The bandstructures for both types are considerably modified when the field strength is large enough to mix neighboring subbands.
A Competitive Model of (Super)Stars

Following Rosen [1981], superstar effects (earnings convex in quality and a few firms reaping a large share of market earnings) occur with imperfect substitution between sellers, low (and possibly declining) marginal cost of output, and marginal cost falling as quality increases. However, markets without such characteristics have superstar effects, and the main result from the superstar model — small quality differences result in large earnings differences — may not hold. A competitive model can yield superstar effects when a few firms have quality significantly higher than others and cost increases in output, provided cost does not increase too rapidly in quality.
An improved model averaging scheme for logistic regression

Recently, penalized regression methods have attracted much attention in the statistical literature. In this article, we argue that such methods can be improved for the purposes of prediction by utilizing model averaging ideas. We propose a new algorithm that combines penalized regression with model averaging for improved prediction. We also discuss the issue of model selection versus model averaging and propose a diagnostic based on the notion of generalized degrees of freedom. The proposed methods are studied using both simulated and real data.
Synthesis of an allene-containing germacranoid

Abstract The anion-induced cyclization of the farnesol derivative IV furnished germacranoid V . Desulfurization of the corresponding sulfoxide gave an allene analogue of the sesquiterpene alcohol, hedycaryol.
DISCRETE SCALE INVARIANCE AND THE SECOND BLACK MONDAY

Evidence is offered for log-periodic (in time) fluctuations in the S&P 500 stock index during the three years prior to the October 27, 1997 "correction". These fluctuations were expected on the basis of a discretely scale invariant rupture phenomenology of stock market crashes proposed earlier.
Consumer protection and financial literacy : lessons from nine country studies

The 2008 global financial crisis has emphasized the need for adequate consumer protection and financial literacy for long-term stability of the financial sector. This Working Paper aims to summarize key lessons from reviews of consumer protection and financial literacy in the nine middle-income countries of Europe and Central Asia: Azerbaijan, Bulgaria, Croatia, the Czech Republic, Latvia, Lithuania, Romania, the Russian Federation and Slovakia. All the country assessments used a systematic common approach, based on a set of Good Practices for Consumer Protection and Financial Literacy developed by the World Bank's Europe and Central Asia Region. A financial consumer protection regime should meet three objectives. First, consumers should receive accurate, simple, comparable information of a financial service or product, before and after buying it. Second, consumers should have access to expedient, inexpensive and efficient mechanisms for dispute resolution with financial institutions. Third, consumers should be able to receive financial education when and how they want it. A common challenge among the nine countries is the need of an adequate institutional structure for financial consumer protection. Regardless of the specific institutional structures, financial consumers should have one single agency where to submit complaints and inquiries. Financial institutions should be required to apply fair, non-coercive and reasonable practices when selling and advertising financial products and services to consumers. Personal data should also be carefully protected.