cssi/SciSciGPT-SciSciNet huggingface dataset:
A parallel branch and bound algorithm for test generation

For circuits of VLSI complexity, test generation time can be prohibitive. Most of the time is consumed by hard-to-detect (HTD) faults, which might remain undetected even after a large number of backtracks. The problems inherent in a uniprocessor implementation of a test generation algorithm are identified, and a parallel test generation method which tries to achieve a high fault coverage for HTD faults in a reasonable amount of time is proposed. A dynamic search space allocation strategy which allocates disjoint search spaces to minimize the redundant work is proposed. The search space allocation strategy tries to utilize the partial solutions generated by other processors to increase the probability of searching in a solution area. The parallel test generation algorithm has been implemented on an Intel iPSC/2 hypercube. It is shown that parallel processing of HTD faults does indeed result in high fault coverage, which is otherwise not achievable by a uniprocessor algorithm. The parallel algorithm exhibits superlinear speedups in some cases due to search anomalies. >
A performance model of effective memory management in HYDRA: a large scale data stream recording system

Presently, digital continuous media (CM) are well established as an integral part of many applications. Scant attention has been paid to servers that can record such streams in real time. However, more and more devices produce direct digital output streams. Hence, the need arises to capture and store these streams with an efficient recorder that can handle both recording and playback of many streams simultaneously and provide a central repository for all data. Because of the continuously decreasing cost of memory, more and more memory is available on a large scale recording system. Unlike most previous work that focuses on how to minimize the server buffer size, this paper investigates how to effectively utilize the additional available memory resources in a recording system. We propose an effective resource management framework that has two parts: (1) a dynamic memory allocation strategy, and (2) a deadline setting policy ( DSP ) that can be applied consistently to both playback and recording streams, satisfying the timing requirements of CM, and also ensuring fairness among different streams. Furthermore, to find the optimal memory configuration, we construct a probability model based on the classic M / G /1 queueing model and the recently developed Real Time Queueing Theory (RTQT) . Our model can predict (a) the missed deadline probability of a playback stream, and (b) the blocking probability of recording streams. The model is applicable to admission control and capacity planning in a recording system.
Base change behavior of the relative canonical sheaf related to higher dimensional moduli

Reference EPFL-ARTICLE-231110doi:10.2140/ant.2013.7.353 URL: http://dx.doi.org/10.2140/ant.2013.7.353 Record created on 2017-09-19, modified on 2017-09-20
Cross‐cultural patterns of honorifics and sociolinguistic sensitivity to honorific variables: Evidence from English, Japanese, and Korean

Abstract In this paper are presented both paradigmatic and syntagmatic patterns of honorifics that compare American English, Japanese, and Korean. A set of cross‐cultural variables of power and solidarity is proposed and discussed in relation to the usages of honorific expressions. Of the three languages in comparison, American English is the least sensitive to all the power variables and group solidarity, to which Japanese and Korean are highly susceptible. In their sociolinguistic behavior, Americans appear to render the greatest relative importance to the intimacy variable, Japanese to groupness, and Koreans to age.
Institutional Arrangements for Rural Poverty Reduction and Resource Conservation

Summary This paper introduces a special issue featuring a set of papers on institutional arrangements for reconciling rural poverty reduction with renewable natural resources conservation in the low-income tropics. Collectively, these papers make four core points. First, synergies do not naturally emerge just because rural poverty reduction and renewable natural resources conservation are each appealing goals with common drivers and some intrinsic interlinkage. Second, it matters less which rules a community or country adopts than how well they monitor and enforce the rules they set. Third, flexibility and adaptability in design are critical to establishing cooperative partnerships that can advance both conservation and development goals. Fourth, multiscalar approaches are commonly desirable.
Coulomb blockade peak spacings: Interplay of spin and dot-lead coupling

For Coulomb blockade peaks in the linear conductance of a quantum dot, we study the correction to the spacing between the peaks due to dot-lead coupling. This coupling can affect measurements in which Coulomb blockade phenomena are used as a tool to probe the energy level structure of quantum dots. The electron-electron interactions in the quantum dot are described by the constant exchange and interaction (CEI) model while the single-particle properties are described by random matrix theory. We find analytic expressions for both the average and rms mesoscopic fluctuation of the correction. For a realistic value of the exchange interaction constant ${J}_{s}$, the ensemble average correction to the peak spacing is two to three times smaller than that at ${J}_{s}=0$. As a function of ${J}_{s}$, the average correction to the peak spacing for an even valley decreases monotonically, nonetheless staying positive. The rms fluctuation is of the same order as the average and weakly depends on ${J}_{s}$. For a small fraction of quantum dots in the ensemble, therefore, the correction to the peak spacing for the even valley is negative. The correction to the spacing in the odd valleys is opposite in sign to that in the even valleys and equal in magnitude. These results are robust with respect to the choice of the random matrix ensemble or change in parameters such as charging energy, mean level spacing, or temperature.
Efficient synthesis of thymidine boranophosphoramidates conjugated with amino acids

An efficient synthesis of a thymidine boranophosphoramidate prodrug was accomplished using a phosphoramidite approach in high yield. This new class of compounds is designed to have improved antiviral and anticancer advantages conferred by combining the boranophosphate and normal nucleoside amino acid phosphoramidate. Compounds were characterized by MS and 31P NMR.
Diameter-dependent electron mobility of InAs nanowires.

Temperature-dependent I−V and C−V spectroscopy of single InAs nanowire field-effect transistors were utilized to directly shed light on the intrinsic electron transport properties as a function of nanowire radius. From C−V characterizations, the densities of thermally activated fixed charges and trap states on the surface of untreated (i.e., without any surface functionalization) nanowires are investigated while enabling the accurate measurement of the gate oxide capacitance, therefore leading to the direct assessment of the field-effect mobility for electrons. The field-effect mobility is found to monotonically decrease as the radius is reduced to <10 nm, with the low temperature transport data clearly highlighting the drastic impact of the surface roughness scattering on the mobility degradation for miniaturized nanowires. More generally, the approach presented here may serve as a versatile and powerful platform for in-depth characterization of nanoscale, electronic materials.
Neutron Scattering Studies of Magnetic Superconductors

After nearly twenty years of theoretical and experimental attempts to understand the mutual effects of superconductivity and magnetism on each other, the existence of long-range order of both kinds in the same material was finally established recently with the advent of the families of ternary compounds which have come to be known as “magnetic superconductors” [1,2]. The general use of this term does not necessarily imply a simultaneous coexistence (e.g., at a given temperature) of long-range magnetic order and superconductivity, although the very existence of superconductivity in crystals which contain ordered lattices of magnetic ions is itself initially very surprising and is believed to be due to the relative weakness of the exchange spin-flip (and therefore pair-breaking) interaction between the closed shell (necessarily f-like) of electrons on the magnetic ions and the conduction-band electrons. Nevertheless, in many of these compounds, magnetic long-range order (LRO) can simultaneously coexist with superconductivity over certain temperature ranges. This is particularly true of the case in which the magnetic LRO is of the antiferromagnetic type. The case of ferromagnetic LRO leads to the phenomenon of “re-entrance” and will be discussed in detail later. The best studied families of these compounds are the ternary borides with the chemical formula ReRh4B4 (where RE is a rare earth ion), and the Chevrel phase compounds with the formula REMo6S8 or REMo6Se8. There exist by now several review articles on these extremely interesting classes of materials, which the reader may consult for more detailed experimental information [3,4]. In this article, we shall concern ourselves with neutron scattering studies of these compounds. Reviews of the recent theoretical developments of the subject may be found in many other papers of this symposium.
On The Choice and Impacts of Innovative International Food Assistance Instruments

Summary The rise of new food assistance instruments, including local and regional procurement, cash, and vouchers, has surpassed increase in understanding of the tradeoffs among and impacts of these options relative to traditional food aid. Response choices rarely appear to result from systematic response analyses. Further, impacts along multiple dimensions—timeliness, cost-effectiveness, local market effects, recipient satisfaction, food quality, impact on smallholder suppliers, etc.—may be competing or synergistic. No single food assistance tool is always and everywhere preferable. A growing body of evidence, including the papers in this special section, nonetheless demonstrates the clear value-added of new food assistance instruments.
Provably good approximation algorithms for optimal kinodynamic planning for Cartesian robots and open-chain manipulators

Inoptimal kinodynamic planning, given a robot system, we must find a minimal-time trajectory that goes from a start state to a goal state while avoiding obstacles by a speed-dependent safety margin and respecting dynamics bounds. With Canny and Reif [1], we approached this problem from anɛ-approximation standpoint and introduced a provably good approximation algorithm for optimal kinodynamic planning for a robot obeying particle dynamics. If a solution exists, this algorithm returns a trajectoryɛ-close to optimal in time polynomial in both (1/ɛ) and the geometric complexity. We extend [1] and [2] tod-link three-dimensional robots with full rigid-body dynamics amidst obstacles. Specifically, we describe polynomial-time approximation algorithms for Cartesian robots obeyingL 2 dynamic bounds and for open-kinematic-chain manipulators with revolute and prismatic joints. The latter class includes many industrial manipulators. The correctness and complexity of these algorithms rely on new trajectory tracking lemmas for robots with coupled dynamics bounds.
Modeling and analysis of integrated spiral inductors for RF system-in-package

In this paper, a fast efficient Method of Moments (MoM) based on a new subdomain partitioning technique is presented for rapidly extracting the distributed capacitance and inductance of spiral inductors. By using this approach, the analytical formula of Green's function for multi-layer substrates is obtained through the prioritized wave-tracing method. The computing time is much faster than the state-of-the-art capacitance and inductance solvers, such as FMMS. Good agreement between numerical results and measurement data is shown to demonstrate the accuracy of the proposed new method.
A methodology for analyzing laser-induced structural damage

The analysis of laser-induced structural damage requires the merging of a thermal analysis which includes the characterization of the laser damage with a structural analysis which enables the determination of the deformation and the residual load carrying ability. Three types of laser-induced damage are considered: loss of structure due to melting, change of material properties due to temperature changes, and addition of load due to thermal stress. The thermal solution is calculated from a set of finite difference equations obtained from heat balances performed at successive finite time increments on an array of finite cells. The structural analysis is performed by a re-analysis technique, applicable when changes in structural stiffness are small compared to the initial value. The combined procedure for evaluating laser damage is applied to two structures, representing two levels of complexity. The first was a simple two-dimensional plate and the second a three-dimensional wing structure. The displacement solutions were compared to results obtained from NASTRAN to determine the accuracy of the iterative solution technique. The procedure was found to be efficient, and permits the parametric studies needed for a-priori estimates of the effectiveness of potential laser weapons systems. 10 references.
Iodine as an Oxidant in the Topotactic Deintercalation of Interstitial Iron in Fe1+xTe

The layered telluride, Fe1+xTe, is a parent compound of the isostructural and superconducting phases, Fe1+x(Te, Se, S). Here we show that, through a simple reaction of I2 vapor with both powder and single crystal samples, the interstitial iron can be removed from the FeTe framework topotactically. Neutron powder diffraction and X-ray single crystal diffraction confirm that the iron being extracted is the partially occupied site that lies between the 2-D blocks of edge-sharing FeTe4 tetrahedra. The deintercalation process has consequences for both magnetic and crystallographic phase transitions in the compound at low temperatures. This technique could be of use for the tuning of stoichiometry of the superconducting phases and therefore enable more careful studies on how chemical composition affects magnetic and superconducting properties.
The tau lepton

The author reviews the experimental knowledge of the properties of the tau lepton and the tau neutrino. The conventional theory of lepton properties and interactions is summarized; and that theory is compared with experiment. Future directions for research in tau and tau neutrino physics are described.
Capital controls and stock market volatility in frequency domain

Abstract The link between capital controls and stock market volatility is examined using frequency domain techniques. Conventional analyses of the second moments can produce spurious results if the high-frequency volatility is reduced (increased) while the overall volatility is increased (reduced).
Use of “Studio” Methods in the Introductory Engineering Design Curriculum

A number of themes, including interest in first year design courses, commitment to active learning approaches, and desires for changes in course structures and costs have come together in a variety of teaching approaches. Some of these approaches have been referred to as using “studio” methods, although the particular pedagogy appears to vary greatly. In this paper, some of these experiments are briefly reviewed and placed in a larger context of studio education in other disciplines. The paper seeks to differentiate studio education from other active learning approaches. An introductory engineering design course was taught using an architecture studio model for two semesters. The experiment demonstrated that the studio method can be very effective in teaching design concepts, but because students are likely to be unfamiliar with this approach, care must be taken to reassure students regarding grades and expectations.
ESTIMATING THE GUMBEL SCALE PARAMETER FOR LOCAL ALIGNMENT OF RANDOM SEQUENCES BY IMPORTANCE SAMPLING WITH STOPPING TIMES

The gapped local alignment score of two random sequences follows a Gumbel distribution. If computers could estimate the parameters of the Gumbel distribution within one second, the use of arbitrary alignment scoring schemes could increase the sensitivity of searching biological sequence databases over the web. Accordingly, this article gives a novel equation for the scale parameter of the relevant Gumbel distribution. We speculate that the equation is exact, although present numerical evidence is limited. The equation involves ascending ladder variates in the global alignment of random sequences. In global alignment simulations, the ladder variates yield stopping times specifying random sequence lengths. Because of the random lengths, and because our trial distribution for importance sampling occurs on a different sample space from our target distribution, our study led to a mapping theorem, which led naturally in turn to an efficient dynamic programming algorithm for the importance sampling weights. Numerical studies using several popular alignment scoring schemes then examined the efficiency and accuracy of the resulting simulations.
Bureaucratic Autonomy in the U.S. Separation of Powers: Evidence from Cabinet Departments

Theories of delegation posit that politicians have the incentive to decrease discretion when ideological conflict with an administrative agency increases. Yet agencies can use their expertise to appropriate informational benefits from delegation helping to increase bureaucratic autonomy. Such theories only indirectly address the impact of ideological conflict on bureaucrats’ perceptions about the extent of the discretion they are afforded on the job. Does the perception of discretion by bureaucrats depend on ideological conflicts between the legislative and executive branches? Statistical results from dynamic panel models provide evidence that that closer ideological alignment with the U.S. Congress than the president increases perceived discretion; that a negative relationship emerges between confirmation times and perceived discretion, but a small and opposite relationship exists among supervisory levels; that variance in the ideological portfolio of cabinet secretaries decreases perceived discretion overall, but has no effect on supervisory cadres; and that divergence between the goals and legal context of an agency and the president’s policy orientation are associated with lower perceived discretion.
The science and detection of gravitational waves

Albert Einstein predicted the existence of gravitational waves as a consequence of the general theory of relativity. In his theory, changes in the shape of concentrations of mass (or energy) warp space-time, cause distortions that propagate through the Universe at the speed of light. However, no direct detection of such waves has yet been made. A new generation of detectors promises sensitivities that will be capable of detection from a variety of catastrophic events, such as the gravitational collapse of stars or the coalescence of compact binary systems
Organocatalytic Enantioselective Olefin Aminofluorination

Chiral β-fluoroamines are increasingly prevalent in medicinal compounds, but there are few efficient methods to access them from achiral starting materials. To address this, a multicomponent organocascade reaction was developed in which chiral α-fluoro-β-amino aldehydes were generated in a single flask from achiral α,β-unsaturated aldehydes (2), using catalyst 12a. Conversions up to 85%, dr’s up to 98:2 and ee’s up to 99% of the corresponding alcohol (9) were achieved in this reaction.
Asymmetric synthesis of aziridine 2-phosphonates and azirinyl phosphonates from enantiopure sulfinimines

Abstract Enantiopure sulfinimine (S)- 4 was employed in a Darzens-type synthesis of aziridine 2-phosphonates (−)-7/(+)-8 wich were transformed into α-amino phosphonates (S)-11/(R)-12 and the first enantiopure examples of azirinyl phosphonates 13–15 .
Constraining the History of the Sagittarius Dwarf Galaxy Using Observations of Its Tidal Debris

We present a comparison of semianalytic models of the phase-space structure of tidal debris with measurements of average distances, velocities, and surface densities of stars associated with the Sagittarius dwarf galaxy, compiled from all observations reported since its discovery in 1994. We find that several interesting features in the data can be explained by these models. The properties of stars about ?10??15? away from the center of Sgr?in particular, the orientation of material perpendicular to Sgr's orbit and the kink in the velocity gradient?are consistent with those expected for unbound material stripped during the most recent pericentric passage ~50 Myr ago. The break in the slope of the surface density seen by Mateo, Olszewski, & Morrison at b ~ -35? can be understood as marking the end of this material. However, the detections beyond this point are unlikely to represent debris in a trailing streamer, torn from Sgr during the immediately preceding passage ~0.7 Gyr ago, as the surface density of this streamer would be too low compared with observations in these regions. The low-b detections are more plausibly explained by a leading streamer of material that was lost more that 1 Gyr ago and has wrapped all the way around the Galaxy to intercept the line of sight. The distance and velocity measurements at b = -40? reported by Majewski et al. in a companion paper also support this hypothesis. We determine debris models with these properties on orbits that are consistent with the currently known positions and velocities of Sgr in Galactic potentials with halo components that have circular velocities vcirc = 140?200 km s-1. In all cases, the orbits oscillate between ~12 and ~40 kpc from the Galactic center with radial time periods of 0.55?0.75 Gyr. The best match to the data is obtained in models where Sgr currently has a mass of ~109 M? and has orbited the Galaxy for at least the last 1 Gyr, during which time it has reduced its mass by a factor of 2?3, or luminosity by an amount equivalent to ~10% of the total luminosity of the Galactic halo. These numbers suggest that Sgr is rapidly disrupting and unlikely to survive beyond a few more pericentric passages. These conclusions are only tentative, because they rely heavily on the less certain measurements of debris properties far from the center of Sgr. However, they demonstrate the immense potential for using debris to determine Sgr's dynamical history in great detail.
Intra- and inter-firm US trade

Abstract Bivariate Tobit gravity regressions using 2000–2007 US trade data show that US-based firms take advantage of positive forces (e.g., economic freedom) operating in foreign markets more through affiliates than third parties. Likewise, transactions with affiliates are deterred a lot more by negative forces (e.g., distance). Additionally, trade flows are higher (lower) with non-OECD (OECD) countries that are more politically free. Decompositions of the Tobit effects and the predicted-to-actual trade ratios indicate a two-pronged strategy for policymakers: develop targeted policies to specific hurdles to intra-firm trade and work aggressively on increasing market access for US exports.
User re-authentication via mouse movements

We present an approach to user re-authentication based on the data collected from the computer's mouse device. Our underlying hypothesis is that one can successfully model user behavior on the basis of user-invoked mouse movements. Our implemented system raises an alarm when the current behavior of user X, deviates sufficiently from learned "normal" behavior of user X. We apply a supervised learning method to discriminate among k users. Our empirical results for eleven users show that we can differentiate these individuals based on their mouse movement behavior with a false positive rate of 0.43% and a false negative rate of 1.75%. Nevertheless, we point out that analyzing mouse movements alone is not sufficient for a stand-alone user re-authentication system.
Random vicious walks and random matrices

A lock step walk is a one-dimensional integer lattice walk in discrete time. Suppose that initially there are infinitely many walkers on the nonnegative even integer sites. At each moment of time, every walker moves either to its left or to its right with equal probability. The only constraint is that no two walkers can occupy the same site at the same time. Hence we describe the walk as vicious. It is proved that as time tends to infinity, a certain limiting conditional distribution of the displacement of the leftmost walker is identical to the limiting distribution of the (scaled) largest eigenvalue of a random GOE matrix (GOE Tracy-Widom distribution). The proof is based on the bijection between path configurations and semistandard Young tableaux established recently by Guttmann, Owczarek, and Viennot. The distribution of semistandard Young tableaux is analyzed using the Hankel determinant expression for the probability obtained from the work of Rains and the author. The asymptotics of the Hankel determinant are then obtained by applying the Deift-Zhou steepest-descent method to the Riemann-Hilbert problem for the related orthogonal polynomials. © 2000 John Wiley & Sons, Inc.
Analysts' forecasts and investments in information technology

Abstract Previous research has shown that investments in intangible assets, especially research and development, can increase the difficulty in forecasting a company's earnings. This information risk translates into a lower market value for the firm. Because IT investments have many intangible characteristics similar to research and development expenditures, information technology investments may also increase information risk. Tests using IT spending data for over 1000 firms show that IT spending does increase earnings forecast dispersion and error. Increased dispersion and error might affect the market value of the firm. Using a residual income valuation model, results show that as IT spending increases, residual income is capitalized into market value at a decreasing amount, controlling for diminishing marginal returns to IT spending. This research highlights the importance for IT-intensive companies to find ways to decrease information risk through other forms of communication with market participants.
Reduction of systolic coronary blood flow in experimental left ventricular outflow tract obstruction

Abstract In aortic valvular stenosis, coronary reserve has been shown to be markedly diminished despite normal coronary arteries. To gain further insight into this phenomenon, we examined the effects of an acute subaortic valvular obstruction on coronary blood flow (CBF) in seven open-chest anesthetized dogs. Transient subaortic obstruction was produced by inflating a catheter-tip balloon in the left ventricular (LV) outflow tract. The degree of obstruction, a 26 ± 3 mm Hg gradient across the aortic valve, was adjusted to achieve an elevation of LV pressure while maintaining a constant aortic pressure (coronary perfusion pressure). In seven dogs with intact coronary vasomotor tone, systolic left anterior descending CBF decreased from 20 ± 9 ml/min during the control period to 13 ± 3 ml/min during subaortic obstruction ( p p
Communication, credible improvements and the core of an economy with asymmetric information

We analyze an economy with asymmetric information and endogenize the possibilities for information transmission between members of a coalition. We then define a concept of the Core that takes into account these communication possibilities. The internal consistency of the improvements is considered and an Internally Consistent Core, which requires credibility from the improvements is introduced.
Strong second harmonic generation from the tantalum thioarsenates A3Ta2AsS11 (A = K and Rb).

The strongly anisotropic thioarsenates A3Ta2AsS11 are stabilized in a polysulfide flux. All compounds contain the same parallel 1/∞[Ta2AsS113−] polymeric anionic chains, but the size of the alkali-metals has a profound effect on the packing of the chains. The K+ or Rb+ favor noncentrosymmetric packing of the chains, whereas the larger Cs+ favors the centrosymmetric packing. The chains feature the combination of two asymmetric units [Ta2S11] and [AsS3] and exhibit strong nonlinear optical (NLO) second harmonic generation (SHG) response. Polycrystalline samples exhibit is up to ∼15 times stronger SHG than that of commercially used AgGaSe2.
Synthesis of Titanium Silicon Carbide

Synthesis of bulk titanium silicon carbide (Ti3SiC2) from the elemental Ti, Si, and C powders has been accomplished for the first time, using the arc-melting and annealing route. The effects of various parameters on the phase purity of the Ti3SiC2 have been examined, including the starting composition of the powders, compaction technique, arc-melting of the samples, and temperature and time of anneal. The best bulk samples, containing about 2 vol% TiC as the second phase, were made from Si-deficient and C-rich starting compositions. Based on electron probe microanalysis data from a number of bulk samples, it appears that Ti3SiC2 exists over a range of compositions; the Ti-Si-C ternary section has been modified to reflect this. The purest samples of the ternary phase were obtained by leaching powders of silicide-containing samples in diluted HF, and contained over99vol%Ti3SiC2.
Single exposure dual-energy digital radiography

Abstract This study presents preliminary results of single kVp dual-energy computed radiography using laser stimulable luminescent phosphor image plate detectors. The single kVp technique makes use of four of these plates in a single cassette, each plate acting as an X-ray filter to the next so that the energy separation required for the dual-energy basis decomposition is achieved. An analysis to determine the best operating technique for the chest is performed using computer simulation, and was found to be 85 kVp and 14 mAs. This technique yields the same entrance exposure value as is used clinically, so that the information for the decomposition is obtained without additional dose to the patient. The iso-transmission line technique was used as the decomposition algorithm. A humanoid chest phantom was used to demonstrate the quality of the resulting calibration material equivalent images.
Analysis of particle transport in a magnetophoretic microsystem

An analytical analysis is presented of the transport and capture of magnetic micro/nanoparticles in a magnetophoretic microsystem that consists of an array of integrated soft-magnetic elements embedded beneath a microfluidic channel. The elements, which are polarized by a bias field, produce a nonuniform field distribution that gives rise to a force on magnetic particles within the microchannel. The equations governing particle motion are derived using analytical expressions for the dominant magnetic and fluidic forces. The magnetic force is obtained using an analytical expression for the field distribution in the microchannel combined with a linear magnetization model for the magnetic response of the particles. The theory takes into account particle size and material properties, the bias field, the dimensions of the microchannel, the fluid properties, and the flow velocity. The equations of motion are solved to study particle transport and capture. The analysis indicates that the particles exhibit an oscillatory motion as they traverse the microsystem, and that a high capture efficiency can be obtained in practice.
Synthesis of Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds through stereoselective catalytic cross-metathesis

The first examples of catalytic cross-metathesis (CM) reactions that furnish Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds are disclosed. Products are generated with high Z selectivity by the use of a W-based monoaryloxide pyrrolide (MAP) complex (up to 91% yield and >98:2 Z:E). The more sterically demanding Z-alkenylboron species are obtained in the presence of Mo-based MAP complexes in up to 93% yield and 97% Z selectivity. Z-selective CM with 1,3-dienes and aryl olefins are reported for the first time. The utility of the approach, in combination with catalytic cross coupling, is demonstrated by a concise and stereoselective synthesis of anticancer agent combretastatin A-4.
Range data analysis using cross-stripe structured-light system

ABSTRACT In this paper, we present a triangulation based range finding system, cross-stripe structured lightsystem (CSSLS), composed of two stripe projectors and a camera generating a cross stripe. We first show a method ofreconstructing surfaces from the range data obtained by CSSLS. The technique utilizesCoon's patch formalism that interpolates the surface solely from the boundary information of the patch.We also show how to extract homogeneous surfaces using CSSLS. Simulation and experimental results of our method are presented. 1 . INTRODUCTION The importance of range data is greater than ever in many aspects of computer integrated manu- facturing: ranging from the solder paste inspection task in surface mounting technology (SMT) used inthe micro electronics manufacturing industry to the design and quality control of aircraft wings or shiphulls. During the past decade, a number of range sensors have been developed for rapid and accuratemeasurement of the range information. The review of the recent development in range sensors can be
The Radial Defocusing Nonlinear Schrödinger Equation in Three Space Dimensions

We study the defocusing nonlinear Schrodinger equation in three space dimensions. We prove that any radial solution that remains bounded in the critical Sobolev space must be global and scatter. In the energy-supercritical setting we employ a space-localized Lin–Strauss Morawetz inequality of Bourgain. In the intercritical regime we prove long-time Strichartz estimates and frequency-localized Lin–Strauss Morawetz inequalities.
Bank resolution costs, depositor preference and asset encumbrance

Purpose – This paper aims to clarify the effects of introducing depositor preference on resolution costs, probability of default and bank funding costs, allowing for the possibility of collateralized funding. Design/methodology/approach – The importance of conflict among creditors in generating bankruptcy costs is documented. A model of such a conflict is provided, which is then used in analyzing the effects of depositor preference and other forms of asset encumbrance. The model takes into account the reactions of providers of secured and unsecured financing. Findings – Depositor preference and collateralization of borrowing may reduce the cost of settling the conflicts among creditors that arises in case of resolution or bankruptcy. This net benefit, which may be capitalized into the value of the bank rather than affect creditors’ expected returns, should result in lower overall funding costs and thus a lower probability of distress despite increasing encumbrance of the bank’s balance sheet. The benefit ...
Social security and the rise in health spending

Abstract In a quantitative model of Social Security with endogenous health, I argue that Social Security increases the aggregate health spending of the economy because it redistributes resources to the elderly whose marginal propensity to spend on health is high. I show by using computational experiments that the expansion of US Social Security can account for over a third of the dramatic rise in US health spending from 1950 to 2000. In addition, Social Security has a spill-over effect on Medicare. As Social Security increases health spending, it also increases the payments from Medicare, thus raising its financial burden.
Multiple-well interference testing in the Ohaaki geothermal field

Multiple interference tests were carried out in the Ohaaki geothermal field between 1979 and 1983. Data were collected for periods of up to 200 days per test with both wellhead-mounted water-level recorders and quartz crystal pressure gauges, each with a resolution of about 0.0145 psi (100 Pa). Data are analyzed by conventional log-log type-curve matching techniques, followed by application of recently developed semilog type-curve matching techniques that allow linear boundary detection without developing two semilog straight lines. One type curve exists for each of the drawdown and buildup data, which are produced by mathematically collapsing the family of curves produced in the solution for a system containing a line source and linear boundary. The type curve for the buildup data has not been previously published. The method allows the inference ellipse for a linear boundary to be determined without any knowledge of reservoir parameters. The data in some tests show the presence of a no-flow boundary for which inference ellipses have been located. Four interference tests performed on the same doublet show that vastly different reservoir parameters can be found unless careful interpretation is made.
Why did World Trade Center collapse? - Simple analysis

Simplified approximate analysis of the overall collapse of the World Trade Center towers is presented. It is shown that if prolonged heating causes the majority of columns of a single floor to lose their load-carrying capacity, the whole tower is doomed.
Regioselective reduction of 4,6-O-benzylidenes using triethylsilane and BF3·Et2O

Abstract The 4,6-di-O-benzylidene acetals of glucose, mannose, glucosamine, and galactose were regioselectively reduced by triethylsilane in the presence of BF3·Et2O to yield the 6-O-benzyl ethers in good to excellent yields.
The Global Economy and the Latino Populations in the United States: A World Systems Approach

There are broad, historical-structural linkages among the distinct Latino groups in the United States, on the basis of which a Latino national minority is forming. In analyzing the disproportional ...
The symmetry of quasiperiodic crystals

Abstract Experimentally observed crystals range from periodic crystals, through incommensurately modulated crystals and composite crystals, to quasicrystals and even modulated quasicrystals. How does one characterize in a unified manner the symmetry of all these types of crystals? How does one classify all crystals according to their symmetry? These questions are answered through a review of the Fourier-space approach to crystal symmetry of Rokhsar, Wright, and Mermin. The notion of indistinguishability, which is central to the approach, is introduced and used as the basis for a generalization of the traditional space-group classification scheme, applicable to all types of crystals known to date.
Gas-phase exposure history derived from material-phase concentration profiles

Non-reactive gas-phase pollutants such as benzene diffuse into indoor furnishings and leave behind a unique material-phase concentration profile that serves as a record of the past gas-phase indoor concentrations. The inverse problem to be solved is the diffusion equation in a slab such as vinyl flooring. Using knowledge of the present material-phase concentration profile in the slab, we seek to determine the historical material-phase concentration at the surface exposed to indoor air, and hence the historical gas-phase concentration, which can be used directly to determine exposure. The problem as posed has a unique solution that may be solved using a variety of approaches. We use a trained artificial neural network (ANN) to derive solutions for hypothetical exposure scenarios. The ANN results show that it is possible to estimate the intensity and timing of past exposures from the material-phase concentration profile in a building material. The overall method is limited by (1) the resolution of techniques for measuring spatial material-phase concentration profiles, (2) how far back in time we seek to determine exposure and (3) the representational power of the ANN solution. For example, we estimate that this technique can estimate exposure to phenol up to 0.5 y in the past from analyses of vinyl flooring.
Do life insurers' asset allocation strategies influence performance within the enterprise risk framework

In this paper we examine the impact of asset allocation strategies on the investment performance of life insurers in the U.S. We are especially interested in comparing the effects of active portfolio management to the effects of passive holding strategies. We define three novel quantitative indices of static/dynamic strategies to represent important dimensions of the active/passive spectrum of investment strategies. The indices are computed from portfolio allocations reported in the firms’ annual statement data. Using cluster analysis, we partition the population of life insurers into three groups, characterised by generally having static (passive), dynamic (active) and mixed asset allocation strategies, respectively. There are major differences among the three clusters in terms of risk profile, size and other factors. We model investment performance and allocations among the major holdings of bonds, stocks, cash and mortgages explicitly as simultaneously interacting phenomena. In order to isolate the effect of allocation strategies from the confounding effects of other risks, we imbed a spectrum of enterprise risks, treated as exogenous or predetermined, within the model framework of endogenously interacting performance and asset allocation variables. The strategy indicators are also exogenous variables. We find that the most active cluster enjoys the greatest relative performance, even controlling for allocations among asset classes.
Approximation in Mechanism Design

This paper considers three challenge areas for mechanism design and describes the role approximation plays in resolving them. Challenge 1: optimal mechanisms are finely tuned to precise details of the distribution on agent preferences. Challenge 2: in environments with multi-dimensional agent preferences economic analysis has failed to provide general characterizations optimal mechanisms. Challenge 3: optimal mechanisms are parameterized by unrealistic knowledge of the distribution of agents' private preferences. This paper surveys positive resolutions to these challenges with emphasis on basic techniques and their relevance to theory and practice.
Novel Route to Functionalized Indans via Formal [3 + 2] Cycloadditions of 1-Benzylbenzotriazoles with Alkenes

Abstract α-Functionalized 1-benzylbenzotriazoles (3, 4 and 12), derived from the lithiation of 1-(2,3-dimethoxybenzyl)benzotriazole 2 followed by reactions with electrophiles, or from the condensation of benzyl alcohol 11 with benzotriazole, undergo formal [3 + 2] cycloadditions with styrenes upon treatment with ZnBr2 to give functionalized indans (9, 10, 13 and 14).
Aerodynamic and Aeroacoustic Optimization of Rotorcraft Airfoils via a Parallel Genetic Algorithm

A parallel genetic algorithm (GA) methodology was developed to generate a family of two-dimensional airfoil designs that address rotorcraft aerodynamic and aeroacoustic concerns. The GA operated on 20 design variables, whichconstitutedthecontrolpointsforasplinerepresentingtheairfoilsurface.TheGAtookadvantageofavailable computer resources by operating in either serial mode, where the GA and function evaluations were run on the same processor or “ manager/worker” parallel mode, where the GA runs on the manager processor and function evaluations areconducted independently on separate workerprocessors. The multiple objectives of this work were to minimizethedrag and overall noiseof the airfoil. Constraintswereplaced on liftcoefe cient, moment coefe cient, andboundary-layerconvergence.TheaerodynamicanalysiscodeXFOILprovidedpressureandsheardistributions in addition to liftand drag predictions. Theaeroacousticanalysis code, WOPWOP, provided thicknessand loading noise predictions. The airfoils comprising the resulting Pareto-optimal set exhibited favorable performance when compared with typical rotorcraft airfoils under identical design conditions using the same analysis routines. The relationship between the quality of results and the analyses used in the optimization is also discussed. The new airfoil shapes could provide starting points for further investigation.
Orthogonal Polynomials and Expansions for a Family of Weight Functions in Two Variables

Orthogonal polynomials for a family of weight functions on [−1,1]2, $$\mathcal{W}_{\alpha,\beta,\gamma}(x,y) = |x+y|^{2\alpha+1}|x-y|^{2\beta+1} \bigl(1-x^2\bigr)^{\gamma}\bigl(1-y^2\bigr)^{\gamma},$$ are studied and shown to be related to the Koornwinder polynomials defined on the region bounded by two lines and a parabola. In the case of γ=±1/2, an explicit basis of orthogonal polynomials is given in terms of Jacobi polynomials, and a closed formula for the reproducing kernel is obtained. The latter is used to study the convergence of orthogonal expansions for these weight functions.
Carbon Nanotube–Magnetite Composites, With Applications to Developing Unique Magnetorheological Fluids

The development of carbon nanotube (CNT) based technology is limited in part by the lack of effective bulk methods for precisely manipulating and aligning nanotubes at the very fine scale. Moreover, the innate hydrophobic and inert nature of the CNT surface limits their compatibility with aqueous systems and flexibility for surface chemistry functionalization. This paper assesses the variety of methods developed to couple magnetically susceptible components such as ferromagnetic material with CNTs in order to overcome these limitations. In addition to reviewing the past 16 years of relevant literature, our own methods for noncovalent surface coating of CNT's with magnetite nanoparticles are described. The application of such composites is then explored within the framework of a magnetorheological (MR) fluid. It is found that the addition of magnetite nanoparticles to a MR fluid enriches the available MR response, resulting, in some cases, in an increased sedimentation stability, larger saturation critical stresses, and faster response to time varying magnetic fields. Finally, our own composite based MR fluid is discussed, and shown to possess a field dependent response that is a hybrid between that observed in ferrofluids and conventional MR fluids.
A study of dynamic load balancing in a distributed system

This paper presents a study of a distributed system consisting of a number of hosts connected by a local area network. The system model is based on the LOCUS distributed file system. The LOCUS file system allows replicated files, and the synchronization policy is enforced by the use of the Centralized Synchronization Sites (CSS). All requests to open a file for access must be sent to the file's CSS which checks for access conflicts. Our simulation model allows process migration. The focus of this study is on load balancing as applied to optimal process and read site placement. An algorithm is proposed that increases system performance through load balancing. This algorithm uses data collected by the system on which to base its decisions. The characteristics of the algorithm and their effects on system performance are analyzed and discussed.