cssi/SciSciGPT-SciSciNet huggingface dataset:
Karhunen Loève feature extraction for neural handwritten character recognition

The optimality of the Karhunen Loeve (KL) transform is well known. Since its basis is the eigenvector set of the covariance matrix, a statistical, not functional, representation of the variance in pattern ensembles is generated. By using the KL transform coefficients as a natural feature representation of a character image, the eigenvector set can be regarded as an unsupervised biological feature extractor for a (neural) classifier. The covariance matrix and its eigenvectors are obtained from 76,753 handwritten digits. This operation is a unique expense; once the basis set is calculated it forms a linear first layer of a three weight layer feed forward network. The subsequent nonlinear perceptron layers are trained using a scaled conjugate gradient algorithm that typically affords an order of magnitude reduction in computation over the ubiquitous back-propagation algorithm. In conjunction with a massively parallel computer, training is expedited such that tens of initially different random weight sets are trained and evaluated. Increase in training set size (up to 76,755 patterns) gives less accurate learning but improved generalization on the fixed disjoint test set. A neural classifier is realized that recognizes 96.1% of 15,000 handwritten digits from 944 different writers. This recognition is attributed to the energy compaction optimality of the KL transform.
From antiferromagnetic insulator to ferromagnetic metal : a brief review of the layered ruthenates

Abstract This paper presents a brief review of recent experimental results of the layered ruthenates (Sr, Ca)n+1,RunO3n+1, with n=1, 2, 3 and ∞ (n=number of Ru–O layers). With the layered nature of the crystal structures and the extended characteristic of the 4d-electrons, these ruthenates provide a truly unique opportunity to study not only the evolution of underlying physical properties as the dimensionality changes but also drastic transitions in ground states (localized antiferromanetism or itinerant ferromagnetism) when the cation (Ca or Sr) is replaced with each other. An enormous range of novel physical phenomena, which are manifested in transport and thermodynamic properties and believed to be fundamentally associated with the bad metallicity that characterizes these systems.
Benzo-fused lactams from a diversity-oriented synthesis (DOS) library as inhibitors of scavenger receptor BI (SR-BI)-mediated lipid uptake.

Abstract We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure–activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50 = 0.10 μM) and solubility (79 μM in PBS), and it was designated as probe ML312.
The effects of environmental risk information on auditors' decisions about prospective financial statements

This study tests a model of how auditors make decisions when presented with environmental risk information in the context of a task that requires their professional opinion on a company's forecasted information. Auditing provided a small-world context where declarative and procedural knowledge have been well documented in terms of the rules for analysing financial information. This research uses a conceptual modelling approach to determine auditors' perceptions of environmental risk information and the effects on their judgement and decision choices when issuing an examination report supporting forecasted financial statements. Auditors were provided with environmental risk information that they had to process and integrate in their decision-making. The results demonstrated that auditors act on unfamiliar declarative knowledge using their standard procedural knowledge. The results from eighty-four senior auditors displayed evidence that auditors' perception of environmental risk information is downplayed c...
Open Source Architecture: An Exploration of Source Code and Access in Architectural Design

ABSTRACT The term open source is increasingly applied to architecture, yet there is little consensus about what it means in this context. This paper explores how different literal and metaphoric interpretations of the “access to source code” principle, set by the founders of the Free and Open Source Software movements, are being applied to architecture. The authors explore several challenges that have arisen in the translation of open source rhetoric from cyberspace to architectural space and discuss paths for new conceptual and programmatic agendas promoting user empowerment and democratization in architectural design.
Turbulence and fossil turbulence in oceans and lakes

Turbulence is defined as an eddy-like state of fluid motion where the intertial-vortex forces of the eddies are larger than any of the other forces that tend to damp the eddies out. Energy cascades of irrotational flows from large scales to small are non-turbulent, even if they supply energy to turbulence. Turbulent flows are rotational and cascade from small scales to large, with feedback. Viscous forces limit the smallest turbulent eddy size to the Kolmogorov scale. In stratified fluids, buoyancy forces limit large vertical overturns to the Ozmidov scale and convert the largest turbulent eddies into a unique class of saturated, non-propagating, internal waves, termed fossil-vorticity-turbulence. These waves have the same energy but different properties and spectral forms than the original turbulence patch. The Gibson (1980, 1986) theory of fossil turbulence applies universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as its growth is constrained and fossilized by buoyancy forces. Quantitative hydrodynamic-phase-diagrams (HPDs) from the theory are used to classify microstructure patches according to their hydrodynamic states. When analyzed in HPD space, previously published oceanic datasets showed their dominant microstructure patches are fossilized at large scales in all layers. Laboratory and field measurements suggested phytoplankton species with different swimming abilities adjust their growth strategies by pattern recognition of turbulence-fossil-turbulence dissipation and persistence times that predict survival-relevant surface layer sea changes. New data collected near a Honolulu waste-water outfall showed the small-to-large evolution of oceanic turbulence microstructure from active to fossil states, and revealed the ability of fossil-density-tubulence patches to absorb, and vertically radiate, internal wave energy, information, and enhanced turbulent-mixing-rates toward the sea surface so that the submerged waste-field could be detected from a space satellite (Bondur and Filatov, 2003).
Fatigue life analysis of a turboprop reduction gearbox

Abstract : A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors. Keywords: Turboprop engines, Fatigue life, and Life adjustment factors.
Practical, asymmetric synthesis of aromatic-substituted bulky and hydrophobic tryptophan derivatives

Abstract An efficient method for the synthesis of novel aromatic substituted, bulky and hydrophobic tryptophan derivatives has been developed. Asymmetric hydrogenations of α-enamide 5 using Burk's DuPHOS-based catalysts generated high enantiomerically pure d - and l -α-amino acid derivatives 6 , which subsequently underwent Suzuki cross couplings with boronic acid derivatives to afford aromatic substituted tryptophan derivatives 7 and 8 in high yields. The method can allow for the preparation of such amino acids in large-scales for extensive structure–activity studies.
Electric field distribution around a biased probe immersed in an electrical discharge

Summary form only given. Electric field distributions are measured around a biased probe immersed in an argon discharge. The distributions are measured as functions of probe bias, argon pressure, and distance of the probe from the "boundary" placed on the plasma by a powered electrode. The electric fields are symmetrically distributed around the probe when the probe is placed sufficiently far from this boundary, but become asymmetric when the sheaths around both the probe and the powered electrode began to couple. For select cases, we discuss how the space charge is distributed around the probe. We also discuss perturbations in the excited 1s4 states that result due to the presence of the probe. In general, we note that while the measurable fields around the probe are contained in a region around the probe on the order of a Debye length (~1lambdaDebye), these perturbations extend many Debye lengths (~10lambdaDebye). We discuss the implication of these measurements both in terms of conventional Langmuir probes used to measure plasma parameters, as well as charged grains of dust that exhibit collective behavior leading to the formation of plasma crystals
The power of randomness in Bayesian optimal mechanism design

Abstract We investigate the power of randomness in the context of a fundamental Bayesian optimal mechanism design problem—a single seller aims to maximize expected revenue by allocating multiple kinds of resources to “unit-demand” agents with preferences drawn from a known distribution. When the agents' preferences are single-dimensional Myerson's seminal work (1981) shows that randomness offers no benefit—the optimal mechanism is always deterministic. In the multi-dimensional case, when agents' preferences are arbitrarily correlated, Briest et al. (2010) showed that the gap between the expected revenue obtained by an optimal randomized mechanism and an optimal deterministic mechanism can be unbounded even when a single agent is offered only 4 services. We show that when the agents' values involve no correlation or a specific kind of positive correlation, the benefit of randomness is only a small constant factor.
Commodity Money Equilibrium in a Convex Trading Post Economy with Transaction Costs

Abstract Existence and efficiency of general equilibrium with commodity money is investigated in an economy where N commodities are traded at N ( N − 1 ) / 2 commodity-pairwise trading posts. Trade is a resource-using activity recovering transaction costs through the spread between bid (wholesale) and ask (retail) prices. Budget constraints, enforced at each trading post separately, imply demand for a carrier of value between trading posts. Existence of general equilibrium is established under conventional convexity and continuity conditions while structuring the price space to account for distinct bid and ask price ratios. Commodity money flows are identified as the difference between gross and net inter-post trades.
Isotopic composition of siderite as an indicator of depositional environment

Compilation of available oxygen and carbon isotopic data for siderites from different depositional environments indicates that marine and continental siderites are characterized by distinctive compositional fields. The most notable difference between the fields is the generally higher δ 13 C values of continental vs. marine siderites. This difference appears to reflect the fact that marine sediments generally undergo a more extensive period of sulfate reduction than do the continental sediments in which siderite forms. Analysis of siderite geochemistry may assist in determination of depositional environment in cases where the available sedimentological evidence is ambiguous.
LEADING EDGE FILM-COOLING EFFECTS ON TURBINE BLADE HEAT TRANSFER

A three-dimensional Navier-Stokes code has been used to study the effect ofspanwise pitch of shower-head holes and coolant to mainstream mass flow ratio on the adiabatic effectiveness and heat transfer coefficient on a film-cooled turbine vane. The mainstream is akin to that under real engine conditions with stagnation temperature 1900 K and stagnation pressure 3 MPa. It is found that with the ratio of coolant to mainstream mass flow being fixed, reducing the spanwise pitch for shower-head holes (P) from 7.5d to 3.0d, where d is the hole diameter, increases the average effectiveness considerably over the blade surface. However, when P / d = 7.5, increasing the coolant mass flow increases the effectiveness on the pressure surface but reduces it on the suction surface owing to coolant jet lift-off. For P / d = 4.5 or 3.0, such an anomaly does not occur within the range of coolant-to-mainstream-mass-flow ratios analyzed. In all cases, adiabatic effectiveness and heat transfer coefficient are highly three-dim...
Political-economic problems in trade capacity building

Theoretically, trade capacity building should contribute to export-led growth and support liberal economic policies. Unfortunately, it often fails to meet this ideal due to resource misallocation, misplaced focus on existing obligations, and donor-driven implementation. This article presents a formal theory of political-economic problems in trade capacity building. I analyze trade liberalization as a repeated game with imperfect public monitoring between a developed and developing country. Modeling trade capacity building as an investment by the developed country, I show that it suffers from two problems. First, the need to enforce trade liberalization drives resource misallocation: costly projects are implemented only to build commitment capacity while others are not implemented because they encourage protectionism. Second, donor interests distort trade capacity building. Counterintuitively, if the donor can seek compensation from the recipient when it violates international trade law, it sometimes refuses to invest in low-cost trade capacity building while funding projects that hurt the recipient.
Clinical characteristics of hereditary hemochromatosis patients who lack the C282Y mutation

Approximately 85% of patients with typical hereditary hemochromatosis (HH) are homozygous for the C282Y mutation (C282Y/C282Y) in the recently identified candidate gene for HH. However, some HH patients are instead homozygous for the wild-type allele (wt/wt) at this locus. These wt/wt patients may represent a phenotypically similar, but genotypically different, heritable trait, or may be unrecognized cases of secondary iron overload. The purpose of this study is to provide an in-depth analysis of the wt/wt HH patients identified in the original description of the HH gene, and to compare them with 62 patients from the same analysis who were homozygous for the C282Y mutation. Eighteen of the 21 wt/wt HH patients from the original study were assessed for 14 historical and laboratory variables, including previously unrecognized causes of secondary iron overload, the heritability of iron overload and liver disease, and other clinical characteristics. Ten of these 18 wt/wt HH patients (55.6%) were found to have previously unrecognized causes for secondary iron overload compared with 3 of 62 (4.8%) of the C282Y/C282Y patients (P < .001). The remaining 8 wt/wt patients had no recognizable etiology of secondary iron overload. None of the 18 wt/wt patients had a family history of iron overload or liver disease, compared with 58% of the C282Y/C282Y patients (P < .001). When compared with C282Y homozygotes, the 8 wt/wt patients without secondary iron overload had a higher presenting hepatic iron index (HII) (9.5 vs. 4.7; P = .01). We conclude that, in this series of patients, over half of the wt/wt HH patients possessed previously unrecognized causes of secondary iron overload, and therefore, may have been misdiagnoses. If these cases are excluded, the number of false-negative tests is decreased, and the sensitivity of the mutational analysis is increased. However, there is a subgroup of wt/wt patients who have typical hemochromatosis without an identifiable cause of secondary iron overload. These patients may have more severe iron loading than C282Y homozygotes.
Electron/nuclear spin domain walls in quantum Hall systems

We propose experiments that can be done using both optically pumped NMR and the technique of all-optical NMR for creating spatially modulated nuclear-spin profiles. Due to the hyperfine coupling these would appear as spatially modulated Overhauser fields for the electrons that could have an amplitude large enough to cancel or even reverse the external Zeeman field at some places. We discuss two-dimensional electron-gas transport in the quantum Hall regime at filling factor $\ensuremath{\nu}=1$ and demonstrate the existence of collective modes and topological excitations induced in the electron gas by various nuclear-spin patterns. We calculate the ${1/T}_{1}$ relaxation rate of the nuclear spins due to coupling with these low-lying collective modes and also discuss how transport and the low-energy modes would be affected by spin-orbit coupling in GaAs quantum wells grown in the $[001]$ and $[110]$ directions.
Sloan Digital Sky Survey

The Sloan Digital Sky Survey is a project which will produce a detailed digital phometric map of half the northern sky to about 23 magnitude using a special purpose wide field telescope of 2.5 meter aperture. This map will be used to select about a million galaxies and 100,000 quasars, for which high resolution spectra will be obtained using the same telescope. A catalog will be produced of all the detected objects, about 100 million galaxies and a similar number of stars, and a million quasar candidates.
Radar sea reflection for low-e targets

Modeling radar signal reflection from a wavy sea surface uses a realistic characteristic of the large surface features and parameterizes the effect of the small roughness elements. Representation of the reflection coefficient at each point of the sea surface as a function of the Specular Deviation Angle is, to our knowledge, a novel approach. The objective is to achieve enough simplification and retain enough fidelity to obtain a practical multipath model. The 'specular deviation angle' as used in this investigation is defined and explained. Being a function of the sea elevations, which are stochastic in nature, this quantity is also random and has a probability density function. This density function depends on the relative geometry of the antenna and target positions, and together with the beam- broadening effect of the small surface ripples determined the reflectivity of the sea surface at each point. The probability density function of the specular deviation angle is derived. The distribution of the specular deviation angel as function of position on the mean sea surface is described.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Contour line construction for a new rectangular facility in an existing layout with rectangular departments

Abstract In a recent paper, Savas et al. [S. Savas, R. Batta, R. Nagi, Finite-size facility placement in the presence of barriers to rectilinear travel, Operations Research 50 (6) (2002) 1018–1031] consider the optimal placement of a finite-sized facility in the presence of arbitrarily shaped barriers under rectilinear travel. Their model applies to a layout context, since barriers can be thought to be existing departments and the finite-sized facility can be viewed as the new department to be placed. In a layout situation, the existing and new departments are typically rectangular in shape. This is a special case of the Savas et al. paper. However the resultant optimal placement may be infeasible due to practical constraints like aisle locations, electrical connections, etc. Hence there is a need for the development of contour lines, i.e. lines of equal objective function value. With these contour lines constructed, one can place the new facility in the best manner. This paper deals with the problem of constructing contour lines in this context. This contribution can also be viewed as the finite-size extension of the contour line result of Francis [R.L. Francis, Note on the optimum location of new machines in existing plant layouts, Journal of Industrial Engineering 14 (2) (1963) 57–59].
Astrometric Observation of MACHO Gravitational Microlensing

Following previous suggestions of other researchers, this paper discusses the prospects for astrometric observation of MACHO gravitational microlensing events. We derive the expected astrometric observables for a simple microlensing event with either a dark or self-luminous lens and demonstrate that accurate astrometry can determine the lens mass, distance, and proper motion in a very general fashion. In particular, we argue that in limited circumstances ground-based, narrow-angle differential astrometric techniques are sufficient to measure the lens mass directly and other lens properties (distance, transverse motion) by applying an independent model for the source distance and motion. We investigate the sensitivity of differential astrometry in determining lens parameters by Monte Carlo methods and derive a quasi-empirical relationship between astrometric accuracy and mass uncertainty.
Physical conditions in the cool parts of prominences

A spectral analysis of the cool parts of seven prominences reported by Shin-Huei (1961) and Yakovkin and Zel'dina (1964) is presented. The analysis requires only measurements of the Na and Sr(+) resonance lines and the middle H Balmer lines, all of which are optically thin, and uses the Na and Sr(+) statistical equilibrium solutions of Landman (1983). It is shown that the Na/H integrated intensity ratios alone are sufficient to determine the degree of H ionization. The major result of this investigation is that the degree of H ionization in the cool prominence parts is very low and the total gas pressure very high.
Coherent Pulse Propagation in Water

We show how transmission through 5.7 meters of water varies with pulse energy and temporal width. 3 orders increase in transmission is observed compared with Beer’s law predictions. The experimental results are compared with 0π-pulses.
Coordination chemistry of heavy polychalcogenide ligands

Abstract The coordination complexes of polychalcogenide ligands with metal ions are reviewed. In the past two decades, the chemistry of metal polysulfides has been extensively studied, while a great deal of attention is currently being paid to metal polyselenides and polytellurides. Compounds of metal heavy polychaleogenides are primarily of interest regarding their structure and reactivity, but they also provide potential for being used as soluble precursors to some technologically relevant metal chalcogenides. This article focuses on coordination compounds of metal polyselenides and polytellurides, both homoleptic species and organometallic complexes with heavy polychalcogenide co-ligands, from the synthetic and structural point of view. After giving a comprehensive survey of the compounds known to date according to the periodic table, some applications and an outlook in this research area are discussed.
Using higher moments of fluctuations and their ratios in the search for the QCD critical point

The QCD critical point can be found in heavy-ion collision experiments via the nonmonotonic behavior of many fluctuation observables as a function of the collision energy. The event-by-event fluctuations of various particle multiplicities are enhanced in those collisions that freeze-out near the critical point. Higher, non-Gaussian, moments of the event-by-event distributions of such observables are particularly sensitive to critical fluctuations, since their magnitude depends on the critical correlation length to a high power. We present quantitative estimates of the contribution of critical fluctuations to the third and fourth moments of the pion, proton and net proton multiplicities, as well as estimates of various measures of pion-proton correlations, all as a function of the same five nonuniversal parameters, one of which is the correlation length that parametrizes proximity to the critical point. We show how to use nontrivial but parameter-independent ratios among these more than a dozen fluctuation observables to discover the critical point. We also construct ratios that, if the critical point is found, can be used to overconstrain the values of the nonuniversal parameters.
On the Failure of Monotonicity in Uniform-Price Auctions

Except for well-studied special cases in which bidders have single-unit demand or bidders are risk-neutral with independent private values, equilibria of uniform-price auctions with private values need not possess familiar monotonicity properties. In particular, equilibria in weakly undominated strategies may exist in which some bidders bid strictly less on some units when they have strictly higher values for every unit.
Magnetic surface states in high polarization materials

Surfaces are often different materials, and typically have a different electronic structure from the bulk and since the dawn of surface science, surface-localized electronic states, surface states, have been extensively studied and investigated with growing accuracy. Of particular importance to spintronics are magnetic surface states. Interfaces will play a very important role in many spintronics devices, yet the interface properties are often ignored, poorly understood or badly characterized. For many nominally half metal materials, materials that in some ground state calculations exhibit 100% spin polarization, the magnetic surface states may significantly reduce the effective spin polarization. We review the magnetic surface states of several well known and often highly touted high spin polarized materials such as NiMnSb, Fe 3 O 4 , CoS 2 and CrO 2 . Finally, we summarize surface state measurements of magnetoelectric antiferromagnets Cr 2 O 3 , which has electrically controllable net surface spins, a major complication to the study of CrO 2 by photoemission.
Nazarov-like cyclization reactions

The Nazarov cyclization, a well-known method for the formation of cyclopentenones, mechanistically involves the 4π electrocyclization of a 1,4-pentadienyl cation, generated from cross-conjugated divinyl ketones. Recently, advances related to this cyclization, such as the incorporation of heteroatoms as well as the use of cyclopropanes as double bond equivalents have extended the scope of the original reaction. The modifications discussed in this review, which covers the years 2009–2013, have allowed the realization of both heteroatom- and homo-Nazarov cyclizations.
Homolytic Substitution at the Sulfur Atom as a Tool for Organic Synthesis

The use of intramolecular homolytic substitution at the sulfur atom by aryl and vinyl radicals, as an alternative to the use of alkyl halides, and chalcogenides as radical precursors in organic synthesis is reviewed.
0.5-V analog circuit techniques and their application in OTA and filter design

We present design techniques that make possible the operation of analog circuits with very low supply voltages, down to 0.5 V. We use operational transconductance amplifier (OTA) and filter design as a vehicle to introduce these techniques. Two OTAs, one with body inputs and the other with gate inputs, are designed. Biasing strategies to maintain common-mode voltages and attain maximum signal swing over process, voltage, and temperature are proposed. Prototype chips were fabricated in a 0.18-/spl mu/m CMOS process using standard 0.5-V V/sub T/ devices. The body-input OTA has a measured 52-dB DC gain, a 2.5-MHz gain-bandwidth, and consumes 110 /spl mu/W. The gate-input OTA has a measured 62-dB DC gain (with automatic gain-enhancement), a 10-MHz gain-bandwidth, and consumes 75 /spl mu/W. Design techniques for active-RC filters are also presented. Weak-inversion MOS varactors are proposed and modeled. These are used along with 0.5-V gate-input OTAs to design a fully integrated, 135-kHz fifth-order elliptic low-pass filter. The prototype chip in a 0.18-/spl mu/m CMOS process with V/sub T/ of 0.5-V also includes an on-chip phase-locked loop for tuning. The 1-mm/sup 2/ chip has a measured dynamic range of 57 dB and draws 2.2 mA from the 0.5-V supply.
A COMPUTATIONAL APPROACH TO FUZZY QUANTIFIERS IN NATURAL LANGUAGES

The generic term fuzzy quantifier is employed in this paper to denote the collection of quantifiers in natural languages whose representative elements are: several, most, much, not many, very many, not very many, few, quite a few, large number, small number, close to five, approximately ten, frequently, etc. In our approach, such quantifiers are treated as fuzzy numbers which may be manipulated through the use of fuzzy arithmetic and, more generally, fuzzy logic. A concept which plays an essential role in the treatment of fuzzy quantifiers is that of the cardinality of a fuzzy set. Through the use of this concept, the meaning of a proposition containing one or more fuzzy quantifiers may be represented as a system of elastic constraints whose domain is a collection of fuzzy relations in a relational database. This representation, then, provides a basis for inference from premises which contain fuzzy quantifiers. For example, from the propositions “Most U's are A's” and “Most A's are B's,” it follows that “Most2 U's are B's,” where most2 is the fuzzy product of the fuzzy proportion most with itself. The computational approach to fuzzy quantifiers which is described in this paper may be viewed as a derivative of fuzzy logic and test-score semantics. In this semantics, the meaning of a semantic entity is represented as a procedure which tests, scores and aggregates the elastic constraints which are induced by the entity in question.
Digital processing of Young's fringes in speckle photography

A new technique for fully automatic diffraction fringe measurement in pointwise analysis of speckle photographs is presented. The fringe orientation and spacing are initially estimated with the help of a 1 D fast Fourier transform (FFT). A 2-D convolution filter is then applied to enhance the estimated image. A fringe pattern with high signal-to-noise ratio is achieved, which makes feasible precise determination of the displacement components. The halo effect is also optimally eliminated in a new way by a halo-division technique. High reliability and accurate determination of displacement components are achieved over a wide range of fringe densities, with the computation time comparing favorably with those for the 2-D autocorrelation method and the iterative 2-D FFT method.
The power of one move: hashing schemes for hardware

In a standard multiple-choice hashing scheme, each item is stored in one of d ≥ 2 hash table buckets. The availability of choice in where items are stored improves space utilization. These schemes are often very amenable to a hardware implementation, such as in a router. Recently, researchers have discovered powerful variants where items already in the hash table may be moved during the insertion of a new item. Unfortunately, these schemes occasionally require a large number of items to be moved to perform an insertion, making them inappropriate for a hardware implementation. We show that it is possible to significantly increase the space utilization of multiple-choice hashing schemes by allowing at most one item to be moved during an insertion. Furthermore, our schemes can be effectively analyzed, optimized, and compared using numerical methods based on fluid limit arguments, without resorting to much slower simulations.
Reducing contention through priority updates

Memory contention can be a serious performance bottleneck in concurrent programs on shared-memory multicore architectures. Having all threads write to a small set of shared locations, for example, can lead to orders of magnitude loss in performance relative to all threads writing to distinct locations, or even relative to a single thread doing all the writes. Shared write access, however, can be very useful in parallel algorithms, concurrent data structures, and protocols for communicating among threads.We study the "priority update" operation as a useful primitive for limiting write contention in parallel and concurrent programs. A priority update takes as arguments a memory location, a new value, and a comparison function >p that enforces a partial order over values. The operation atomically compares the new value with the current value in the memory location, and writes the new value only if it has higher priority according to >p. On the implementation side, we show that if implemented appropriately, priority updates greatly reduce memory contention over standard writes or other atomic operations when locations have a high degree of sharing. This is shown both experimentally and theoretically. On the application side, we describe several uses of priority updates for implementing parallel algorithms and concurrent data structures, often in a way that is deterministic, guarantees progress, and avoids serial bottlenecks. We present experiments showing that a variety of such algorithms and data structures perform well under high degrees of sharing. Given the results, we believe that the priority update operation serves as a useful parallel primitive and good programming abstraction as (1) the user largely need not worry about the degree of sharing, (2) it can be used to avoid non-determinism since, in the common case when >p is a total order, priority updates commute, and (3) it has many applications to programs using shared data.
THE THERMAL MEMORY OF REIONIZATION HISTORY

The recent measurement by WMAP of a large electron-scattering optical depth τe = 0.17 ± 0.04 is consistent with a simple model of reionization in which the intergalactic medium (IGM) is ionized at redshift z ~ 15 and remains highly ionized thereafter. Here we show that existing measurements of the IGM temperature from the Lyα forest at z ~ 2-4 rule out this "vanilla" model. Under reasonable assumptions about the ionizing spectrum, as long as the universe is reionized before z = 10 and remains highly ionized thereafter, the IGM reaches an asymptotic thermal state that is too cold compared to observations. To simultaneously satisfy the cosmic microwave background and Lyα forest constraints, the reionization history must be complex: reionization begins early at z 15, but there must have been significant (order-of-unity) changes in fractions of neutral hydrogen and/or helium at 6 < z < 10 and/or singly ionized helium at 4 < z < 10. We describe a physically motivated reionization model that satisfies all current observations. We also explore the impact of a stochastic reionization history and show that a late epoch of (He → He ) reionization induces a significant scatter in the IGM temperature, but the scatter diminishes with time quickly. Finally, we provide an analytic formula for the thermal asymptote and discuss possible additional heating mechanisms that might evade our constraints.
Finding an optimal path without growing the tree

For problems on computing an optimal path as well as its length in a certain setting, the "standard" approach for finding an actual optimal path is by building (or "growing") a single-source optimal path tree. In this paper, we study a class of optimal path problems with the following phenomenon: The space complexity of the algorithms for reporting the lengths of single-source optimal paths for these problems is asymptotically smaller than the space complexity of the "standard" tree-growing algorithms for finding actual optimal paths. We present a general and efficient algorithmic paradigm for finding an actual optimal path for such problems without having to grow a single-source optimal path tree. Our paradigm is based on the "marriage-before-conquer" strategy, the prune-and-search technique, and a new data structure called clipped trees. The paradigm enables us to compute an actual path for a number of optimal path problems and dynamic programming problems in computational geometry, graph theory, and combinatorial optimization. Our algorithmic solutions improve the space bounds (in certain cases, the time bounds as well) of the previously best known algorithms, and settle some open problems. Our techniques are likely to be applicable to other problems.
Application of digital simulation techniques to highway design problems

A study of the operating characteristics of the driver-vehicle combination has yielded a general digital simulation model. This simulation model, which can duplicate traffic flow on a 17,000-ft. section of a freeway including two on-ramps and two off-ramps, can be used to economically evaluate alternate design criteria.The simulated vehicle in the model, following decision rules based on actual traffic behavior, is allowed to maneuver through the section of freeway under study. The effects of changes in traffic volume, traffic velocity, freeway configuration, etc., can then be evaluated by noting changes in the computer output of traverse time, waiting time on ramp, volume-velocity relationship, weaving complexity, etc.The computer simulation thus creates a duplication of the real situation at a small fraction of the cost of studying the real system. Furthermore, the simulation allows: (1) the evaluation of various freeway configurations without the expense of their construction, and (2) the performance of controlled experiments impossible to perform with the actual traffic.
Black market premia, exchange rate unification, and inflation in Sub-Saharan Africa

World Bank and International Monetary Fund (IMF) programs favor unification of official and black market exchange rates on the argument that multiple exchange rates misallocate resources. This article shows that such policy advice sometimes overlooks an important consideration : when multiple rates are a means of taxation, the widened deficit from unification increases inflation. This article uses the experience of Ghana, Nigeria, and Sierra Leone to illustrate the tradeoff between the benefits of unification for resource allocation and its cost for inflation.
Traveling-Wave Chemotaxis.

A simple model is studied for the chemotactic movement of biological cells in the presence of a periodic chemical wave. It incorporates the feature of adaptation that may play an important role in allowing for ``rectified'' chemotaxis: motion opposite the direction of wave propagation. The conditions under which such rectification occurs are elucidated in terms of the form and speed of the chemical wave, the velocity of chemotaxis, and the time scale for adaptation. An experimental test of the adaptation dynamics is proposed.
A new pentacyclic sulfated hydroquinone from the marine sponge Haliclona sp.

Abstract A new pentacyclic sulfated hydroquinone, phuklona sulfate, has been isolated from the marine sponge Haliclona sp. collected near Phuket Island, Thailand. The structure was elucidated by a variety of spectroscopic methods including 1D and 2D NMR experiments. Phuklona sulfate contains a novel triterpenoid carbon skeleton linked to a sulfated hydroquinone moeity.
Synthesis and Characterization of Annulene-Fused Pseudorotaxanes

A 24-crown-8 ether-fused dehydrobenzo[18]annulene has been prepared via a stepwise Pd/Cu-mediated strategy. This annulene-crown ether hybrid forms a pseudorotaxane complex in CD 2 Cl 2 with dibenzylammonium hexafluorophosphate when they are combined in a 1:1 ratio, as indicated by 1 H NMR spectroscopy and mass spectrometry.
The Aging-Associated Enzyme CLK-1 Is a Member of the Carboxylate-Bridged Diiron Family of Proteins

The aging-associated enzyme CLK-1 is proposed to be a member of the carboxylate-bridged diiron family of proteins. To evaluate this hypothesis and characterize the protein, we expressed soluble mouse CLK-1 (MCLK1) in Escherichia coli as a heterologous host. Using Mossbauer and EPR spectroscopy, we established that MCLK1 indeed belongs to this protein family. Biochemical analyses of the in vitro activity of MCLK1 with quinone substrates revealed that NADH can serve directly as a reductant for catalytic activation of dioxygen and substrate oxidation by the enzyme, with no requirement for an additional reductase protein component. The direct reaction of NADH with a diiron-containing oxidase enzyme has not previously been encountered for any member of the protein superfamily.
The Equivariant Gromov-Witten theory of P**1

We express all equivariant Gromov-Witten invariants of the projective line as matrix elements of explicit operators acting in the Fock space. As a consequence, we prove the equivariant theory is governed by the 2-Toda hierarchy of Ueno and Takasaki. This is the second in a sequence of three papers devoted to the Gromov-Witten theory of nonsingular target curves (the first paper of the series is math.AG/0204305).
Minimality and complementarity properties associated with Z-functions and M-functions

A nonlinear generalization of square matrices with non-positive off-diagonal elements is presented, and an algorithm to solve the corresponding complementarity problem is suggested. It is shown that the existence of a feasible solution implies the existence of a least solution which is also a complementary solution. A potential application of this nonlinear setup in extending the well-known linear Leontief input—output systems is discussed.
Effect of ruthenium-loading on the catalytic activity of Ru-NaZSM-5 zeolites for nitrous oxide decomposition

Abstract The effect of Ru-loading on the performance of Ru-NaZSM-5 catalysts prepared by ion exchange (extent of ruthenium exchange: 20–100%) in the decomposition of nitrous oxide was studied in the temperature range of 40–700°C. The turnover frequency (TOF) for nitrous oxide decomposition (number of nitrous oxide molecules converted per ruthenium site per unit time) increased significantly with decreasing Ru-loading. Although lower Ru-loading resulted in higher TOF and lower apparent activation energy for nitrous oxide decomposition, this occurred at the expense of stronger inhibition by oxygen. Therefore, to obtain catalysts that remain active in the presence of excess oxygen, high Ru-loaded catalysts (close to 100% of exchange) are needed; whereas in the absence of oxygen, low Ru-loadings (close to 20% of exchange) are preferred. The high TOF observed in Ru-NaZSM5-20 was attributed to the interaction between ruthenium and sodium cations.
A mild preparation of substituted indolizines and indole from simple aromatic precursors using (trimethylsilyl)diazomethane

A mild and convenient synthesis of substituted indolizines from readily available 2-(pyridin-2-yl)acetyl derivatives using (trimethylsilyl)diazomethane is described. The extension of this methodology to the synthesis of indole from 2-aminobenzaldehyde is also reported.
Enumerative Geometry of Calabi-Yau 4-Folds

Gromov-Witten theory is used to define an enumerative geometry of curves in Calabi-Yau 4-folds. The main technique is to find exact solutions to moving multiple cover integrals. The resulting invariants are analogous to the BPS counts of Gopakumar and Vafa for Calabi-Yau 3-folds. We conjecture the 4-fold invariants to be integers and expect a sheaf theoretic explanation.
Superconductivity and stoichiometry in the BSCCO-family materials

We report on magnetization, c-axis and ab-plane resistivity, critical current, electroni band structure and superconducting gap properties. Bulk measurements and photoemission data were taken on similar samples.
The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 347 ± 13 Ma and an eNd143 value of +40.1 ± 0.9. Maskelynite fractions do not lie on the Sm–Nd isochron and appear to contain a martian surface component with low 147Sm/144Nd and 143Nd/144Nd ratios that was added during shock. The Rb–Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial 87Sr/86Sr ratio of 0.7016 is estimated by passing a 347 Ma reference line through the maskelynite fraction that is least affected by contamination. The high initial eNd143 value and the low initial 87Sr/86Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible-element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with similar Sr–Nd isotopic systematics. These similarities suggest that these two meteorites share a close petrogenetic relationship and might have been erupted from a common volcano. The meteorites Yamato 980459, Dar al Gani 476, Sayh al Uhaymir 005/008, and Dhofar 019 also have relatively old ages between 474 and 575 Ma and trace element and/or isotopic systematics that are indicative of derivation from incompatible-element-depleted sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of meteorites is modeled with the MELTS algorithm using the bulk composition of Yamato 980459 as a parent. These models reproduce many of the major element and mineralogical variations observed in the suite. In addition, the rare earth element systematics of these meteorites are reproduced by fractional crystallization using the proportions of phases and extents of crystallization that are calculated by MELTS. Other shergottites that demonstrate enrichments in incompatible-elements and have evolved Sr and Nd isotopic systematics have some geochemical systematics that are similar to those observed in the depleted group. Most notably, although they exhibit a very limited range of incompatible trace element and isotopic compositions, they have highly variable major element compositions. This is also consistent with evolution from a common mantle source region by variable amounts of fractional crystallization. If this scenario is correct, it suggests that the combined effects of source composition and fractional crystallization are likely to account for the major element, trace element, and isotopic diversity of all shergottites.