cssi/SciSciGPT-SciSciNet huggingface dataset:
On Cohen–Macaulay Rings of Invariants

Abstract We investigate the transfer of the Cohen–Macaulay property from a commutative ring to a subring of invariants under the action of a finite group. Our point of view is ring theoretic and not a priori tailored to a particular type of group action. As an illustration, we discuss the special case of multiplicative actions, that is, actions on group algebras k[ Z n] via an action on Z n.
Risk-factor fusion for predicting multifactorial diseases

A generalized classification methodology is developed to predict the presence or absence of a multifactorial disease from a set of risk factors thought to be correlated with the disease. The methodology includes fusion to combine risk factors into a single feature vector, normalization to overcome the problems associated with fusing features which have different formats and ranges, discrete Karhunen-Loeve transform (DKLT)-based transformation to facilitate parametric classifier development, the selection of features with high interclass separations, and the design of parametric classifiers. The validity of the method is demonstrated by applying it to predict the occurrence of gout from 14 risk factors. Cross-validation evaluations on 96 patients, 48 clinically diagnosed to have gout and 48 diagnosed to not have gout, showed that an average classification accuracy of 75.7% can be obtained. Even more promising is that higher classification accuracies can be achieved through the careful selection of the DKLT transformation matrix which in turn involves selecting design sets that are good representatives of the gout and nongout classes. It is concluded that the generalized methodology developed in this paper is quite effective in predicting multifactorial diseases and can, therefore, assist/support a physician in diagnosing a multifactorial disease.
Global patterns of child health: the role of nutrition.

Almost two-thirds of the deaths of children around the world are directly or indirectly associated with nutritional deficiencies. Both protein-energy malnutrition and micronutrient deficiencies increase the risk of death from common diseases such as acute gastroenteritis, pneumonia and measles. Iron deficiency anemia is estimated to affect almost 25% of the world's population (equivalent to 3.5 billion people) resulting in high economic costs by adding to the burden on healthcare services, affecting learning in school and reducing adult productivity. Dietary practices frequently seen in older children and adolescents from industrialized countries, leading to frequent consumption of often nutrient-poor foods, may also put them at risk of micronutrient deficiencies. Marginal nutrient deficiencies in the developed world are increasingly accepted as risk factors for the development of chronic disease such as cardiovascular disease or some cancers.
Repurchase loyalty for customer social co-creation e-marketplaces

Purpose – Social co-creation refers to the process of using social media as a vehicle to carry out customer co-creation engagements. By allowing many customers to contribute to a specific co-creation initiative, social media makes co-creation platforms more efficient. The purpose of this paper is to examine: first, whether usability and information quality, visual appeal and image, interactivity, and web innovativeness, as perceived web site quality dimensions, were related to value equity; second, whether value equity was related to commitment and repurchase loyalty to social co-creation; and third, the moderating effects of aesthetic appreciation and fashion opinion leadership. Design/methodology/approach – The conceptual foundation was based on the Quality-Value-Satisfaction model. Data were collected from US online apparel shoppers (n=691) using a consumer panel via an online survey. Structural equation modeling was employed to test the proposed model and research hypotheses. Findings – Usability and ...
The Unusual Infrared Object HDF-N J123656.3+621322* **

We describe an object in the Hubble Deep Field North with very unusual near-infrared properties. It is readily visible in Hubble Space Telescope NICMOS images at 1.6 ?m and from the ground at 2.2 ?m, but it is undetected (with S/N 2) in very deep WFPC2 and NICMOS data from 0.3 to 1.1 ?m. The f? flux density drops by a factor 8.3 (97.7% confidence) from 1.6 to 1.1 ?m. The object is compact but may be slightly resolved in the NICMOS 1.6 ?m image. In a low-resolution, near-infrared spectrogram, we find a possible emission line at 1.643 ?m, but a reobservation at higher spectral resolution failed to confirm the line, leaving its reality in doubt. We consider various hypotheses for the nature of this object. Its colors are unlike those of known Galactic stars, except perhaps the most extreme carbon stars or Mira variables with thick circumstellar dust shells. It does not appear to be possible to explain its spectral energy distribution as that of a normal galaxy at any redshift without additional opacity from either dust or intergalactic neutral hydrogen. The colors can be matched by those of a dusty galaxy at z 2, by a maximally old elliptical galaxy at z 3 (perhaps with some additional reddening), or by an object at z 10 whose optical and 1.1 ?m light have been suppressed by the intergalactic medium. Under the latter hypothesis, if the luminosity results from stars and not an AGN, the object would resemble a classical, unobscured protogalaxy, with a star formation rate 100 M? yr-1. Such UV-bright objects are evidently rare at 2 < z < 12.5, however, with a space density several hundred times lower than that of present-day L* galaxies.
Management and results of localized Ewing's sarcoma.

Seventy-six patients with localized Ewing's sarcoma who received primary treatment at M. D. Anderson Hospital from 1948 through December 1975 were reviewed. Patients have been divided into four groups according to the different treatment regimens they received: Group I, moderate dose radiotherapy alone; Group II, high dose radiotherapy alone; Group III, radiotherapy plus vincristine and cytoxan; and Group IV, radiotherapy plus vincristine, Adriamycin, cytoxan and actinomycin. The problem of local recurrence appears to be solved with combined chemotherapy and radiation therapy with only one of 36 patients having a recurrence at the primary site in Groups III and IV. Multimodal therapy is the preferred treatment to obtain control of the primary lesion by radiation therapy while preserving good function. However, the major cause of failure remains distant metastases, 19 of 36 (53%) in Groups III and IV. In addition, 4 of 10 patients who have survived over 5 years have developed osteogenic sarcoma. Cancer 43:1001–1006, 1979.
Spectral evidence for zeolite in the dust on Mars

Abstract Spectral features observed in Mars Global Surveyor Thermal Emission Spectrometer data ( ∼ 1670 –220 cm−1) of martian surface dust provide clues to its mineralogy. An emissivity peak at ∼ 1630 cm−1 is consistent with the presence of an H2O-bearing mineral. This spectral feature can be mapped globally and shows a distribution related to the classical bright regions on Mars that are known to be dust covered. An important spectral feature at ∼ 830 cm−1 present in a newly derived average spectrum of surface dust likely is a transparency feature arising from the fine particulate nature of the dust. Its shape and location are consistent with plagioclase feldspars and also zeolites, which essentially are the hydrous form of feldspar. The generally favored visible/near-infrared spectral analog for martian dust, JSC Mars-1 altered tephra, does not display the ∼ 830 cm−1 feature. Zeolites commonly form from the interaction of low temperature aqueous fluids and volcanic glass in a variety of geologic settings. The combination of spectral features that are consistent with zeolites and the likelihood that Mars has (or had) geologic conditions necessary to produce them makes a strong case for recognizing zeolite minerals as likely components of the martian regolith.
Standard logarithmic mean velocity distribution in a band-limited restricted nonlinear model of turbulent flow in a half-channel

Numerical simulations of wall-turbulence using the restricted nonlinear (RNL) model generate realistic mean velocity profiles in plane Couette and channel flow at low Reynolds numbers. The results are less accurate at higher Reynolds number, and while a logarithmic region is observed, its von Karman constant is not consistent with the standard logarithmic law. In half-channel flow, we show that limiting the streamwise-varying wavenumber support of RNL turbulence to one or few empirically determined modes improves its predictions considerably. In particular, the mean velocity profiles obtained with the band-limited RNL model follow standard logarithmic behavior for the higher Reynolds numbers in this study.
Trends in gender segregation in the choice of science and engineering majors.

Numerous theories have been put forward for the high and continuing levels of gender segregation in science, technology, engineering, and mathematics (STEM) fields, but research has not systematically examined the extent to which these theories for the gender gap are consistent with actual trends. Using both administrative data and four separate longitudinal studies sponsored by the U.S. Department of Education’s National Center for Education Statistics (NCES), we evaluate several prominent explanations for the persisting gender gap in STEM fields related to mathematics performance and background and general life goals, and find that none of them are empirically satisfactory. Instead, we suggest that the structure of majors and their linkages to professional training and careers may combine with gender differences in educational goals to influence the persisting gender gap in STEM fields. An analysis of gendered career aspirations, course-taking patterns, and pathways to medical and law school supports this explanation.
The effects of negative information transference in the celebrity endorsement relationship

Purpose – The purpose of this paper is to test empirically the impact of negative information about a celebrity spokesperson on consumers' perceptions of the endorsed brand. In addition, it is the first study to examine the reverse relationship: the impact of negative information about the brand on the celebrity endorser.Design/methodology/approach – A two‐group, post‐test‐only, randomized experimental design was utilized to test the hypotheses. Data were collected by a survey of 247 college students.Findings – The results of an experiment indicate that when respondents are exposed to negative information about a celebrity endorser, a negative transference of affect in the endorsement relationship will occur. However, when the situation is reversed and the respondents are exposed to negative information about the brand, the transference of affect is mitigated.Research limitations/implications – The present study provides a starting‐point for further research on negative information transference in the cel...
Instanton representation of Plebanski gravity. Euclidean signature minisuperspace solution

Using the action for the instanton representation of Plebanski gravity (IRPG), we construct minisuperspace solutions restricted to diagonal variables. We have treated the Euclidean signature case with zero cosmological constant, depicting a gravitational analogy to free particle motion. This paper provides a testing ground for IRPG for a simple case, which will be extended to the full theory in future work.
Government investment and fiscal stimulus

Effects of government investment are studied in an estimated neoclassical growth model. The analysis focuses on two dimensions that are critical for understanding government investment as a fiscal stimulus: implementation delays for building public capital and expected fiscal adjustments to deficit-financed spending. Implementation delays can produce small or even negative labor and output responses to increases in government investment in the short run. Anticipated fiscal adjustments matter both quantitatively and qualitatively for long-run growth effects. When public capital is insufficiently productive, distorting financing can make government investment contractionary at longer horizons.
On the Relation between Hot Jupiters and the Roche Limit

Many of the known extrasolar planets are "hot Jupiters," giant planets with orbital periods of just a few days. We use the observed distribution of hot Jupiters to constrain the location of its inner edge in the mass-period diagram. If we assume a slope corresponding to the classical Roche limit, then we find that the edge corresponds to a separation close to twice the Roche limit, as expected if the planets started on highly eccentric orbits that were later circularized. In contrast, any migration scenario would predict an inner edge right at the Roche limit, which applies to planets approaching on nearly circular orbits. However, the current sample of hot Jupiters is not sufficient to provide a precise constraint simultaneously on both the location and the slope of the inner edge.
Foreign Investment in Local Currency Bonds : Considerations for Emerging Market Public Debt Managers

Foreign investors are increasingly important participants in the local currency sovereign bond markets of developing countries. This note provides context on the overall growth of local currency sovereign debt markets in emerging markets and the growth of foreign investor participation in these markets, a short review of the relevant academic literature, and a summary of the sources of foreign demand. The note concludes with a discussion of the implications of growing foreign investor participation for the managers of public domestic debt in developing countries. The aim of the note is to provide a useful, practically-oriented primer for debt managers beginning to engage on this issue, and in particular to facilitate moving the dialogue beyond overly simple categorizations of countries as"emerging markets"and of investors as a homogeneous source of"hot money".
401(k) Investment Decisions and Social Security Reform

This paper uses the 1995 Survey of Consumer Finances to show that 401(k) participants with an underlying defined benefit plan are more likely to invest in equities than are participants whose 401(k) is their primary plan, suggesting that workers with a guaranteed source of retirement income are more likely to invest their other retirement assets more aggressively. Removing this guarantee might result in more conservative investment. Therefore, using current 401(k) asset allocation behavior to project income under a Social Security individual account system with reduced guaranteed benefits could overstate returns to these accounts, thus overstating their attractiveness relative to the current system.
TEXPLORE: real-time sample-efficient reinforcement learning for robots

The use of robots in society could be expanded by using reinforcement learning (RL) to allow robots to learn and adapt to new situations online. RL is a paradigm for learning sequential decision making tasks, usually formulated as a Markov Decision Process (MDP). For an RL algorithm to be practical for robotic control tasks, it must learn in very few samples, while continually taking actions in real-time. In addition, the algorithm must learn efficiently in the face of noise, sensor/actuator delays, and continuous state features. In this article, we present texplore, the first algorithm to address all of these challenges together. texplore is a model-based RL method that learns a random forest model of the domain which generalizes dynamics to unseen states. The agent explores states that are promising for the final policy, while ignoring states that do not appear promising. With sample-based planning and a novel parallel architecture, texplore can select actions continually in real-time whenever necessary. We empirically evaluate the importance of each component of texplore in isolation and then demonstrate the complete algorithm learning to control the velocity of an autonomous vehicle in real-time.
Vehicle index estimation for signalized intersections using sample travel times

Abstract We introduce in this paper the concept of vehicle indices in a cycle at a signalized intersection which are the positions of vehicles in the departure process of the cycle. We show that vehicle indices are closely related to the vehicle arrival and the departure processes at the intersection. Based on vehicle indices and sample travel times collected from mobile sensors, a three-layer Bayesian Network model is constructed to describe the stochastic intersection traffic flow by capturing the relationship of vehicle indices, and the arrival and departure processes. The non-homogeneous Poisson process and log–normal distributions are used respectively to model the stochastic arrival and departure processes. The methods of parameter learning and vehicle index inference are presented based on the observed intersection travel times. Simplification to the methods is discussed to reduce the computational effort of parameter learning and vehicle index estimation. The model is tested using data from NGSIM, a field test, and simulation with reasonable results.
A social science of human rights

Why do governments abuse human rights, and what can be done to deter and reverse abusive practices? This article examines the emerging social science on these two questions. Over the last few decades, scholars have made consid- erable progress in answering the first one. Abuse stems, centrally, from conflict and institutions. Answers to the sec- ond question are more elusive because data are scarce and the relationships between cause and effect are hard to pin down. Lively debates concern the effectiveness of tools such as military intervention, economic policy, international law, and information strategies for protecting human rights. The evidence suggests that despite the explosion of inter- national legal instruments, this strategy has had impact only in special circumstances. Powerful states play central roles in protecting human rights through sanctions, impartial military intervention, and other tools - often applied unilaterally, which suggests that there is an ongoing tension between the legitimacy of broad multilateral legal insti- tutions and narrower strategies that actually work. The best approaches to managing human rights depend on the political organization of the abuser. Where strong centralized organizations are the problem, the best strategies alter the incentives of leaders at the top; where abuse arises from disarray, such as during civil war or fragile democratic transition, the key tasks include reducing agency slack and making organizations stronger and more accountable.
Nonparametric Reduced Rank Regression

We propose an approach to multivariate nonparametric regression that generalizes reduced rank regression for linear models. An additive model is estimated for each dimension of a q-dimensional response, with a shared p-dimensional predictor variable. To control the complexity of the model, we employ a functional form of the Ky-Fan or nuclear norm, resulting in a set of function estimates that have low rank. Backfitting algorithms are derived and justified using a nonparametric form of the nuclear norm subdifferential. Oracle inequalities on excess risk are derived that exhibit the scaling behavior of the procedure in the high dimensional setting. The methods are illustrated on gene expression data.
Parametric Finite Element Analysis of Physical Stimuli Resulting From Mechanical Stimulation of Tissue Engineered Cartilage

While mechanical stimulation of cells seeded within scaffolds is widely thought to be beneficial, the amount of benefit observed is highly variable between experimental systems. Although studies have investigated specific experimental loading protocols thought to be advantageous for cartilage growth, less is known about the physical stimuli (e.g., pressures, velocities, and local strains) cells experience during these experiments. This study used results of a literature survey, which looked for patterns in the efficacy of mechanical stimulation of chondrocyte seeded scaffolds, to inform the modeling of spatial patterns of physical stimuli present in mechanically stimulated constructs. The literature survey revealed a large variation in conditions used in mechanical loading studies, with a peak to peak strain of 10% (i.e., the maximum amount of deformation experienced by the scaffold) at 1 Hz on agarose scaffolds being the most frequently studied parameters and scaffold. This loading frequency was then used as the basis for simulation in the finite element analyses. 2D axisymmetric finite element models of 2 ×4 mm 2 scaffolds with 360 modulus/permeability combinations were constructed using COMSOL MULTIPHYS-ICS software. A time dependent coupled pore pressure/effective stress analysis was used to model fiuidlsolid interactions in the scaffolds upon loading. Loading was simulated using an impermeable frictionless loader on the top boundary with fluid and solid displacement confined to the radial axis. As expected, all scaffold materials exhibited classic poro-elastic behavior having pressurized cores with low fluid flow and edges with high radial fluid velocities. Under the simulation parameters of this study, PEG scaffolds had the highest pressure and radial fluid velocity but also the lowest shear stress and radial strain. Chitosan and KLD-12 simulated scaffold materials had the lowest radial strains and fluid velocities, with collagen scaffolds having the lowest pressures. Parametric analysis showed maximum peak pressures within the scaffold to be more dependent on scaffold modulus than on permeability and velocities to depend on both scaffold properties similarly. The dependence of radial strain on permeability or modulus was more complex; maximum strains occurred at lower permeabilities and moduli, and the lowest strain occurred at the stiffest most permeable scaffold. Shear stresses within all scaffolds were negligible. These results give insight into the large variations in metabolic response seen in studies involving mechanical stimulation of cell-seeded constructs, where the same loading conditions produce very different results due to the differences in material properties.
Derivative-Free Model Reference Adaptive Control

A derivative-free, delayed weight update law is developed for model reference adaptive control of continuous-time uncertain systems, without assuming the existence of constant ideal weights. Using a Lyapunov―Krasovskii functional it is proven that the error dynamics are uniformly ultimately bounded, without the need for modification terms in the adaptive law. Estimates for the ultimate bound and the exponential rate of convergence to the ultimate bound are provided. Also discussed are employing various modification terms for further improving performance and robustness of the adaptively controlled system. Examples illustrate that the proposed derivative-free model reference adaptive control law is advantageous for applications to systems that can undergo a sudden change in dynamics.
CONSISTENCY CONDITIONS FOR AdS/CFT EMBEDDINGS

The group embeddings used in orbifolding the AdS/CFT correspondence to arrive at quiver gauge field theories are studied for both supersymmetric and nonsupersymmetric cases. For an orbifold AdS5×S5/Γ the conditions for embeddings of the finite group Γ in the SU(4)~O(6) isotropy of S5 are stated in the form of consistency rules, both for Abelian and non-Abelian Γ.
Does Capital Account Liberalization Lead to Growth

We test whether capital account liberalization led to higher economic growth using de jure measures of capital account and financial current account openness for 94 nations, from 1950 (or independence) onward. We argue that measurement error, differing time periods used, and collinearity among independent variables account for conflicting results in prior scholarship. We use pooled time-series, cross-sectional OLS and system GMM estimators toexamineeconomicgrowthrates,1955‐2004.Capitalaccountliberalizationhadapositive association with growth in both developed and emerging market nations. We confirm that equity market liberalization has an independent effect on economic growth. (JEL F02, F43, P16) In this paper, we reexamine the effects of capital account liberalization on economic growth in the context of addressing the inconsistent and widely diverging results that have been reported in the scholarly literature over the last decade. (See the comprehensive review essays on the topic by Eichengreen, 2001 and Kose et al., 2006; henceforth KPRW.) We strive to untangle the reasons behind this inconsistency, and to situate our results in the broader literature on finance and growth. • We propose that conflicting prior results are associated in part with measurement error in capital account variables. We offer a new dataset that contains more precise de jure measures of capital account regulation for a wide sample of countries (94) for up to 50 years (1950 to 1999). The
A versatile computer driven display system for the classroom

The last two decades have seen education in the sciences, mathematics and engineering move from a practical base to the teaching of highly sophisticated abstract principles. The changes have been rapid and radical. Generally, they have affected subject matter only and for the most part this new material is being taught by traditional methods. The changes in subject matter are proper, but they must be accompanied by changes in pedagogy. The use of display-based, highly interactive computer simulations represents one approach toward building the required new pedagogy.
Pulse distortion and optimum transmit waveform for pulse-based UWB communications

This paper initiates a new investigation of optimum transmission waveforms in the presence of per-path pulse wave shape distortion - a physical mechanism unique to impulsive signals. First, the transient electromagnetic analysis is carried out to derive, for the first time, closed-form expressions for the impulse responses of several canonical channels that are suitable for communication engineers. Second, numerical calculation using the inverse Fourier transform of the frequency-domain expressions is compared with the derived closed-form expressions, to verify the validity of these derived impulse responses. Third, propagation mechanisms responsible for multipath and per-path pulse shape distortion can be clearly identified using the closed-form impulse responses. Finally, using these closed-form expressions as a departure point, optimum transmission waveforms determined by a Fredholm integration equation are investigated, for different physical mechanisms, including one path or no multipath (wedge), two paths (rectangular building) and more than two paths (two half plane waveguide).
Learning from weaving for digital fabrication in architecture

This project restructures weaving performance in architecture by analyzing the tacit knowledge of traditional weavers through perceptual study and converting it into an explicit rule in computational design. Three implementations with different materials show the advantages of using computational weaving that combines traditional principles with today's digital (CAD/CAM) tools to develop affordable fabrication techniques.
Putting Management Capacity Building at the Forefront of Health Systems Strengthening; Comment on “Management Matters: A Leverage Point for Health Systems Strengthening in Global Health”

The current limited focus on management in global health activities is highly problematic given the amounts of financial and human resources that are pouring into health system strengthening interventions and the complexity of clinical operations across settings. By ensuring that public health and healthcare practitioners in domestic and international settings receive management training in their educational programs and that we build management capacity among individuals already in the health workforce, we can begin to prepare for more effective health systems strengthening efforts. Rigorous evaluation of health systems strengthening and the impact of management capacity building is crucial to building evidence for the field.
Internationally Correlated Jumps

Stock returns are characterized by extreme observations, jumps that would not occur under the smooth variation typical of a Gaussian process. Jumps are prevalent in most countries, but their cross-country comovements have not been extensively documented. This is important because international diversification is less effective if jumps are frequent, unpredictable, and strongly correlated. We investigate using returns on broad equity indexes from eighty-two countries and modern statistical measures of jumps. We find that jumps are weakly correlated internationally, except within Europe. Although the variation in ordinary returns seems to reflect systematic global factors, jumps are more idiosyncratic.
Statistical mechanics: a possible model for market-based electric power control

Statistical mechanics provides a useful analog for understanding the behavior of complex adaptive systems, including electric power markets and the power systems they intend to govern. Market-based control is founded on the conjecture that the regulation of complex systems based on price-mediated strategies (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper discusses the derivation and some illustrative applications of a first-principles model of market-based system dynamics based on strict analogies to statistical mechanics.
Lack of a neuroprotective effect from N-acetylcysteine after cardiac arrest and resuscitation in a canine model.

Abstract Objective: Oxygen free radicals cause brain injury following resuscitation from cardiac arrest. In preclinical trials, some free radical scavenging drugs reduce oxidative neuronal damage after ischemia and reperfusion, but these drugs are generally not yet available for clinical testing or use. N -Acetylcysteine (NAC), a commonly used antidote in acetaminophen poisoning, is also a potent free radical scavenger that can ameliorate oxidative injury following ischemia and reperfusion in neuronal cell culture. We hypothesized that treatment with NAC would improve neurological outcome after cardiac arrest and resuscitation. Methods: In 16 adult female beagles, 10 min of ventricular fibrillation was followed by 3 min of open-chest CPR, and defibrillation. Immediately following return of spontaneous circulation, animals randomly received either 150 mg/kg NAC (3% solution) ( n =8) or an equivalent volume of normal saline ( n =8). Twenty-three hours later, neurological deficit was scored (0=normal, 100=brain death). Results: All animals were successfully resuscitated, and there were no apparent adverse effects to the administration of NAC in post resuscitative animals. There was, however, no significant difference in neurological deficit in the animals receiving NAC (40±12.9, mean±SD) compared to control animals (44±6.5, P =0.73). Conclusion: No neuroprotective effect was found from the administration of NAC at currently used clinical dosages, to dogs subjected to 10 min of global cerebral ischemia from cardiac arrest and resuscitation.
On Pricing Barrier Options

B oyle and Lau (hereafter BL) [1994] have illustrated how a naive application of the binomial option pricing algorithm can lead to significantly biased estimates in the prices of a variety of barrier, capped, and vulnerable options, even when the number of time steps is large. The source of the problem arises from the location of the barrier with respect to adjacent layers of nodes in the lattice. BL show that if the layers of the lattice are set up so that the barrier falls between layers of the lattice, the errors may be quite significant. To avoid these errors, they constrain the time partition so that the resulting lattice has layers that are as close as possible to the barrier. While this procedure reduces the size of errors, refining the partition size may not necessarily produce more precise results. Moreover, the BL procedure may be difficult to implement if the barriers are time-varying or if there are multiple barriers. This article provides a simple and highly efficient algorithm that can be used to price and hedge options that have single barriers that are either at constant levels or time-varying as well as contracts that are subject to multiple barriers. First, a lattice is constructed to pass through the barrier points exactly. Second, the stock price partition and the
Dynamic Scheduling of a Two-Server Parallel Server System with Complete Resource Pooling and Reneging in Heavy Traffic: Asymptotic Optimality of a Two-Threshold Policy

We consider a dynamic control problem for a parallel server system commonly known as the N-system. An N-system is a two-server parallel server system with two job classes, one server that can serve both classes, and one server that can only serve one class. We assume that jobs within each class arrive according to a renewal process. The random service time of a job has a general distribution that may depend on both the job's class and the server providing the service. Each job independently reneges, or abandons the queue without receiving service, if service does not begin within an exponentially distributed amount of time. The objective is to minimize the expected infinite horizon discounted cost of holding jobs in the system and having customers abandon, by dynamically scheduling waiting jobs to available servers. It is not possible to solve this control problem exactly, and so, we consider an asymptotic regime in which the system satisfies both a heavy traffic and a resource pooling condition. Then, we solve the limiting Brownian control problem, and interpret its solution as a policy in the original N-system. We label the servers and job classes so that server 1 can only serve class 1 and server 2 can serve both classes. The policy we propose has two thresholds. There is one threshold on the total number of jobs in the system, and one threshold on the number of class 1 jobs in the system. These thresholds are used to determine which job class server 2 should serve. We show that this proposed policy is asymptotically optimal within a specified class of admissible policies in the heavy traffic limit, and has the same limiting cost as the Brownian control problem solution.
Optimal Betti numbers of forest ideals

We prove a tight lower bound on the algebraic Betti numbers of tree and forest ideals and an upper bound on certain graded Betti numbers of squarefree monomial ideals.
Maximum entropy direct models for speech recognition

Traditional statistical models for speech recognition have mostly been based on a Bayesian framework using generative models such as hidden Markov models (HMMs). This paper focuses on a new framework for speech recognition using maximum entropy direct modeling, where the probability of a state or word sequence given an observation sequence is computed directly from the model. In contrast to HMMs, features can be asynchronous and overlapping. This model therefore allows for the potential combination of many different types of features, which need not be statistically independent of each other. In this paper, a specific kind of direct model, the maximum entropy Markov model (MEMM), is studied. Even with conventional acoustic features, the approach already shows promising results for phone level decoding. The MEMM significantly outperforms traditional HMMs in word error rate when used as stand-alone acoustic models. Preliminary results combining the MEMM scores with HMM and language model scores show modest improvements over the best HMM speech recognizer.
War and the Sectoral Distribution of Wealth: Evidence from United States Firms

We examine the sector-specific distributive effect of war in the US economy. We argue that war generates sector-specific distributive effects via demand-side and supply-side mechanisms. We also claim that war's distributive effects materialize over time. Our empirical analysis utilizes a panel data set with 22,354 U.S. firms for the period from 1960 to 2007. It probes the impact of the U.S. Government's war making on firm performance in the U.S. arms and non-arms (hybrid and civilian) sectors in both the short and long runs. Our analysis shows that war does not always affect U.S. non-arms sectors adversely. Indeed, war exercises a positive total long-run effect for these sectors. It also finds that the supposedly positive distributive effect of war for U.S. arms sectors proves weaker than analysts generally assume. Finally, it demonstrates that war-induced demand and supply shocks can explain these results. Overall, our research sheds light on a relatively understudied aspect of war and advances the general understanding of the political microeconomy of war making.
QUANTUM COHOMOLOGY OF ORTHOGONAL GRASSMANNIANS

Let V be a vector space with a nondegenerate symmetric form and OG be the orthogonal Grassmannian which parametrizes maximal isotropic subspaces in V. We give a presentation for the (small) quantum cohomology ring QH ⁄ (OG) and show that its product structure is determined by the ring of e P-polynomials. A 'quantum Schubert calculus' is formulated, which includes quantum Pieri and Giambelli formulas, as well as algorithms for computing Gromov{Witten invariants. As an application, we show that the table of 3- point, genus zero Gromov{Witten invariants for OG coincides with that for a corresponding Lagrangian Grassmannian LG, up to an involution.
Limitations of the Application of Fourfold Table Analysis to Hospital Data.

In the biologic laboratory we have a method of procedure for determining the effect of an agent or process that may be considered typical. It consists in dividing a group of animals into two cohorts, one considered the “experimental group,” the other the “control.” On the experimental group some variable is brought to play; the control is left alone. The results are set up as in table 1-a. If the results show that the ratio a:a þb is different from the ratio c:c þd, it is considered demonstrated that the process brought to bear on the experimental group has had a significant effect. A similar method is prevalent in statistical practice, which I venture to think has come into authority because of its apparent equivalence to the experimental procedure. In Biometrika it is referred to as the fourfold table and it is used as a paradigm of statistical analysis. The usual arrangement is that given in table 1-b. The entries, a, b, c and d are manipulated arithmetically to determine whether there is any correlation between A and B. A considerable number of indices have been elaborated to measure this correlation. Pearson has given the formula for calculating the product-moment correlation coefficient from a fourfold table on the assumption that the distribution of both variates is normal; Yule has an index of association for the fourfold table; there are the chi-square test and others. In essence, however, all these indices measure in different ways whether and how much, in comparison with the variation of random sampling, the ratio a:a þb differs from the ratio c:c þd. If the difference departs significantly from zero, there is said to be correlation, and the correlation is the greater the greater the difference. Now there is a distinction between the method as used in the laboratory and as applied in practical statistics. In the experimental situation, the groups, B and not B, are selected before the subgroupings, A and not A, are effected; that is, we start with a total group of unaffected animals. In the statistical application, the groupings, B and not B, are made after the subgroupings, A and not A, are already determined; that is, all the effects are already produced before the investigation starts. In the end, the tables of the results which are drawn up look alike for the two cases, but they have been arrived at differently. Correlative to this difference, a different interpretation may apply to the results, and this paper deals with a specific case of a kind that arises frequently in a medical clinic or a hospital. I take an example.
Sparse Polynomial Learning and Graph Sketching

Let f : {-1, 1}n - ℝ be a polynomial with at most s non-zero real coefficients. We give an algorithm for exactly reconstructing f given random examples from the uniform distribution on {- 1,1}n that runs in time polynomial in n and 2s and succeeds if the function satisfies the unique sign property: there is one output value which corresponds to a unique set of values of the participating parities. This sufficient condition is satisfied when every coefficient of f is perturbed by a small random noise, or satisfied with high probability when s parity functions are chosen randomly or when all the coefficients are positive. Learning sparse polynomials over the Boolean domain in time polynomial in n and 2s is considered notoriously hard in the worst-case. Our result shows that the problem is tractable for almost all sparse polynomials. Then, we show an application of this result to hypergraph sketching which is the problem of learning a sparse (both in the number of hyperedges and the size of the hyperedges) hypergraph from uniformly drawn random cuts. We also provide experimental results on a real world dataset.
Engineering Modular Viral Scaffolds for Targeted Bacterial Population Editing

Bacteria are central to human health and disease, but existing tools to edit microbial consortia are limited. For example, broad-spectrum antibiotics are unable to accurately manipulate bacterial communities. Bacteriophages can provide highly specific targeting of bacteria, but assembling well-defined phage cocktails solely with natural phages can be a time-, labor- and cost-intensive process. Here, we present a synthetic-biology strategy to modulate phage host ranges by engineering phage genomes in Saccharomyces cerevisiae. We used this technology to redirect Escherichia coli phage scaffolds to target pathogenic Yersinia and Klebsiella bacteria, and conversely, Klebsiella phage scaffolds to target E. coli by modular swapping of phage tail components. The synthetic phages achieved efficient killing of their new target bacteria and were used to selectively remove bacteria from multi-species bacterial communities with cocktails based on common viral scaffolds. We envision that this approach will accelerate phage-biology studies and enable new technologies for bacterial population editing.
Statistical mechanics of an optical phase space compressor

We describe the statistical mechanics of a new method to produce very cold atoms or molecules. The method results from trapping a gas in a potential well, and sweeping through the well a semi-permeable barrier, one that allows particles to leave but not to return. If the sweep is sufficiently slow, all the particles trapped in the well compress into a very cold gas. We derive analytical expressions for the velocity distribution of particles in the cold gas, compare these results with numerical simulations, and discuss limitations on reduction in energy due to imperfections of the barrier.
Exploring demand for forestry in Lake Victoria Basin (Western Kenya): An econometric approach

This paper determines the demand for a forestry program amongst rural households in western Kenya. It is based on a field survey with 277 households, using a stratified random sampling approach. The study follows attribute based method to elicit farmers’ preferences. Demand is measured in terms of additional number of trees that a household is willing to plant under different price schedules, including direct economic incentive to plant new seedlings. The mean willingness to plant new trees per household increases from 44 trees when farmers have to pay 10ksh/seedling, to 244 trees when farmers receive a payment of 10ksh/seedling. The paper uses fixed effects, random effects and random effect tobit models to estimate relevant parameters. Hausman specification test is returned insignificant, while implies that random effects specification is not incorrect. Price of seedlings (negative effect), availability of timber species (positive effect), gender of the respondent (men likely to plant more trees than women), and availability of agricultural labor at the household (positive) were all found to be significant. Increase in price of a seedling by 1Ksh reduced demand by nine seedlings, while addition of an adult who works full-time on the family farm will raise the demand for seedlings by 18. Furthermore, farmers in Yala River basin were likely to plant more trees than those in the Nyando River basin.
The AIRSAR/TOPSAR integrated multi-frequency polarimetric and interferometric SAR processor

To really derive the maximum information content from SAR data, it is desirable to combine polarimetric and interferometric techniques, preferably at multiple frequencies. The NASA/JPL AIRSAR/TOPSAR system is capable of simultaneously acquiring interferometric (C- and/or L-band) and polarimetric data (C-, L- and P-band). The authors describe a processing approach that is used to process data acquired in these modes. This approach is different from that described by Madsen et al. (1993) in both the motion compensation approach, as well as in the sense that data are deskewed before interferograms are formed. Using this approach, the same basic SAR processor is used to process data acquired in any of the modes supported by the AIRSAR/TOPSAR system.
Global optimization using accurate approximations in design synthesis

The design variable space of a design synthesis problem may contain multiple local optima. In the approximation concepts approach to design synthesis, the design objective and constraint functions are approximated in order to reduce the overall cost. If the approximations accurately capture the actural behavior of the objective function and constraints, then the approximate design variable space may also contain local optima. In this work, a multistart optimization algorithm is used to search for the global optimum of the actual design using just a few design cycles. Example problems are presented to illustrate the methodology set forth.
Congressional voting on funding the international financial institutions

The United States is the largest contributor to the International Monetary Fund (IMF) and the World Bank, providing resources in exchange for voting power in these international financial institutions (IFIs). While the Treasury Department manages the day-to-day aspects of US participation in these institutions, Congress retains authority on funding. With the aim of understanding the microincentives of US support for the IFIs, I analyze congressional voting on bills to fund the IFIs. I argue that members of congress are more likely to support a funding increase (1) the more “liberal” their ideology, (2) the larger the share of campaign contributions they get from banks that specialize in international lending, and (3) the larger the share of voters that gain from economic globalization that reside in their districts. Statistical analyses of voting on five IFI funding bills since 1977 provide support for these arguments.
A 16-Day-Old Breast-fed Infant with Metabolic Acidosis Caused by Salicylate

This is a report of a 16-day-old, breast-fed infant who presented with metabolic acidosis and no history of drug ingestion. Salicylate intoxication was demonstrated as the probable cause of the acidosis.
Removal of respiratory artifacts from cardiogenic impedance signal by digital filtering

The use of a digital high-pass filter designed and implemented on a personal computer for thoracic impedance cardiography (ZCG) is discussed. Two male subjects were tested under supine, sitting and 50-W exercise conditions. The first derivative of the thoracic impedance signal was recorded by a standard four-electrode impedance cardiograph. The digital high-pass filter automatically selects its cutoff frequency (CF) as a fraction of the heart rate. It was determined that a fractional value of 0.35 provides the best elimination of breathing artifacts with minimal effect on the cardiac signal. >