cssi/SciSciGPT-SciSciNet huggingface dataset:
"USE OF ASYMMETRIC-CYCLE AUTOREGRESSIVE MODELS TO IMPROVE FORECASTING OF AGRICULTURAL TIME SERIES VARIABLES"

Threshold autoregressive (TAR) models can accommodate the asymmetric cycling behavior observed in some time series data. This study develops a procedure to estimate TAR models when the conditional mean of the dependent variable is function of one or more exogenous factors while allowing for heteroskedasticity, i.e. for different levels of variation in upward versus downward cycles. The formulas to obtain predictions from TAR models are derived. Monte Carlo simulation analyses suggest that TAR models can significantly improve forecasting precision. Substantial gains in forecasting precision, in comparison with AR models, are in fact found when applying the proposed procedure to the modeling of U.S. quarterly soybeans future prices and Brazilian coffee spot prices. The estimated TAR models also provide useful insights on the markedly different dynamics of the upward versus the downward cycles exhibited by U.S. soybeans and Brazilian coffee prices.
Enantioselective synthesis of α-phenyl- and α-(dimethylphenylsilyl)alkylboronic esters by ligand mediated stereoinductive reagent-controlled homologation using configurationally labile carbenoids

Chain extension of boronic esters by the action of configurationally labile racemic lithium carbenoids in the presence of scalemic bisoxazoline ligands was explored for the enantioselective synthesis of the two title product classes. Enantioenriched 2° carbinols generated by oxidative work-up (NaOOH) of initial α-phenylalkylboronate products were obtained in 35–83% yield and 70–96% ee by reaction of B-alkyl and B-aryl neopentyl glycol boronates with a combination of O-(α-lithiobenzyl)-N,N-diisopropylcarbamate and ligand 3,3-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl] pentane in toluene solvent (−78 °C to rt) with MgBr2·OEt2 additive. Enantioenriched α-(dimethylsilylphenylsilyl)alkylboronates were obtained in 35–69% yield and 9–57% ee by reaction of B-alkyl pinacol boronates with a combination of lithio(dimethylphenylsilyl)methyl 2,4,6-triisopropylbenzoate and ligand 2,2-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl]propane in cumene solvent (−45 °C to −95 °C to rt). The stereochemical outcome of the second type of reaction depended on the temperature history of the organolithium·ligand complex indicating that the stereoinduction mechanism in this case involves some aspect of dynamic thermodynamic resolution.
Building up to macroprogramming: an intermediate language for sensor networks

There is widespread agreement that a higher level programming model for sensor networks is needed. A variety of models have been developed, but the community is far from consensus. We propose an intermediate language to speed up the exploration of this design space. Our language, called the token machine language (TML) can be targeted by compilers for higher level systems. TML provides a layer of abstraction for a lower-level runtime environment, such as TinyOS. TML is intended to capture coordinated activity in a sensor network. Notable features of TML are its atomic action model of concurrency, and its unification of communication, control, and storage around the concept of a token. Tokens are small objects, typically under a hundred bytes, and can be disseminated across the network. A token causes computation upon its arrival at a site by invoking a token handler. The effect of the computation is to atomically change the token's own state as well as the state of shared variables at the site.
Formation of a Zinc Oxide/Yttria-Stabilized Zirconia Interface

Zinc oxide was deposited on the (111) face of an yttria-stabilized zirconia single crystal using the chemical vapor phase method. Zinc vapor was obtained by reducing polycrystalline ZnO in hydrogen at 1200°C. The deposition of the ZnO was accomplished by the reoxidation of zinc vapor at temperatures of 1300° to 1345°C.
Design and Implementation of a Nonblocking 2-Dilated Flattened Butterfly Switching Network

High-performance computing is highly dependent on the communication network connecting the nodes. In this paper, we present a design and implementation of the 2-dilated flattened butterfly (2DFB) network topology, which provides nonblocking performance for relatively low cost overhead. The flattened butterfly is known to be a cost efficient topology for high-radix networks. Because of its inherent path diversity, it is able to provide comparable cost/performance with the folded-Clos network in adversarial traffic conditions. However, the flattened butterfly is a blocking network and this blocking behavior can degrade the performance of the network when all compute nodes are transmitting and receiving data at full bandwidth. 2DFB network exhibits nonblocking behavior which is a critical factor in deciding the quality of any high performance computing system network. We have implemented the network using the NetFPGA as the switching element and verified the nonblocking behavior of 2DFB. We also compare the performance of a 2DFB with other switching networks. We also show that the 2DFB topology can be used to build high speed switching systems with reduced cost.
A matrix fed circular array for continuous scanning

Abstract : If the radiators of a circular array are connected to the outputs of a Butler matrix, a focused radiation pattern can be formed by establishing the proper current distribution on the inputs of the Butler matrix. Further, if the amplitudes of the input currents are held fixed, the pattern can be scanned through 360 degrees in azimuth by the operation of phase shifters alone, just as the pattern of a linear array is scanned by varying the phases of the element currents. One explanation of this is based on the assumption that the pattern can be written as the sum of a finite number of uniform pattern modes and that the relative phases and amplitudes of these modes can be adjusted to form a narrow beam. Then the beam is scanned by adjusting the currents feeding the Butler matrix. This is only qualitatively correct; the patterns calculated from the actual current distribution established on the array by the matrix differ from the patterns formed from the ideal modes. There is reasonable agreement between the calculated patterns and those obtained experimentally with a 32-element array of dipoles used to demonstrate how a beam could be formed and then scanned. The inputs to the Butler matrix required to achieve a prescribed cophasal sector distribution on the array are determined from the synthesis procedure of Davies with the corresponding changes in the current distribution on the array for other beam positions. (Author)
An On-Chip NBTI Sensor for Measuring pMOS Threshold Voltage Degradation

Negative bias temperature instability (NBTI) is one of the most critical device reliability issues in sub-130 nm CMOS processes. In order to better understand the characteristics of this mechanism, accurate and efficient means of measuring its effects must be explored. In this work, we describe an on-chip NBTI degradation sensor using a delay-locked loop (DLL), in which the increase in pMOS threshold voltage due to NBTI stress is translated into a control voltage shift in the DLL for high sensing gain. The proposed sensor is capable of supporting both DC and AC stress modes. Measurements from a test chip fabricated in a 130 nm bulk CMOS process show an average gain of 10 in the operating range of interest, with measurement times in tens of microseconds possible for minimal unwanted threshold voltage recovery. NBTI degradation readings across a range of operating conditions are presented to demonstrate the flexibility of this system.
Policy iteration for decentralized control of Markov decision processes

Coordination of distributed agents is required for problems arising in many areas, including multi-robot systems, networking and e-commerce. As a formal framework for such problems, we use the decentralized partially observable Markov decision process (DECPOMDP). Though much work has been done on optimal dynamic programming algorithms for the single-agent version of the problem, optimal algorithms for the multiagent case have been elusive. The main contribution of this paper is an optimal policy iteration algorithm for solving DEC-POMDPs. The algorithm uses stochastic finite-state controllers to represent policies. The solution can include a correlation device, which allows agents to correlate their actions without communicating. This approach alternates between expanding the controller and performing value-preserving transformations, which modify the controller without sacrificing value. We present two efficient value-preserving transformations: one can reduce the size of the controller and the other can improve its value while keeping the size fixed. Empirical results demonstrate the usefulness of value-preserving transformations in increasing value while keeping controller size to a minimum. To broaden the applicability of the approach, we also present a heuristic version of the policy iteration algorithm, which sacrifices convergence to optimality. This algorithm further reduces the size of the controllers at each step by assuming that probability distributions over the other agents' actions are known. While this assumption may not hold in general, it helps produce higher quality solutions in our test problems.
Predicted Changes in Advanced Turboprop Noise with Shaft Angle of Attack

Advanced turboprop blade designs and new propeller installation schemes motivated an effort to include unsteady loading effects in existing propeller noise prediction computer programs. The present work validates the prediction capability while studing the effects of shaft inclination on the radiated sound field. Classical methods of propeller performance analysis supply the time-dependent blade loading needed to calculate noise. Polar plots of the sound pressure level (SPL) of the first four harmonics and overall SPL are indicative of the change in directivity pattern as a function of propeller angle of attack. Noise predictions are compared with newly available wind tunnel data and the accuracy and applicability of the prediction method are discussed. It is concluded that unsteady blade loading caused by inclining the propeller with respect to the flow changes the directionality and the intensity of the radiated noise. These changes are well modeled by the present quasi-steady prediction method.
Discovery of gallium, germanium, lutetium, and hafnium isotopes

Currently, twenty-eight gallium, thirty-one germanium, thirty-five lutetium, and thirty-six hafnium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Facieplatycauda pratti gen. n., sp. n. and Two New Species of Myxobolus (Myxosporida)

Synopsis. Facieplatycauda pratti gen. n., sp. n. and Myxobolus kozloffi sp. n., from the Klamath Lake sucker,Catostomus luxatus (Cope), are described. The new genus is placed in the family Myxobolidae between Henneguya and Myxobolus. The spore valves beyond the sporoplasmic space are broad and long but not attenuated as an inverted triangle as in certain species of Myxobolus with tails, or of Henneguya with sometimes bifurcated tails. An organism resembling Myxobolus insidiosus (Wyatt & Pratt) was found in the muscle of the body of Salmo clarki (Richardson). Differences in spore structure and site of infection suggest this is a subspecies of the previous form which should be designated Myxobolus insidiosus clarki. A previously unreported species of Myxobolus from Cottus aleuticus (Gilbert) is also described.
Spitzer IRAC Photometry of M, L, and T Dwarfs

We present the results of a program to acquire photometry for 86 late M, L, and T dwarfs using the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We examine the behavior of these cool dwarfs in various color-color and color-magnitude diagrams composed of near-IR and IRAC data. The T dwarfs exhibit the most distinctive positions in these diagrams. In M_(5.8) versus [5.8]-[8.0], the IRAC data for T dwarfs are not monotonic in either magnitude or color, giving the clearest indication yet that the T dwarfs are not a one-parameter family in T_(eff). Because metallicity does not vary enough in the solar neighborhood to act as the second parameter, the most likely candidate then is gravity, which in turn translates to mass. Among objects with similar spectral type, the range of mass suggested by our sample is about a factor of 5 (~70M_J to ~15M_J), with the less massive objects making up the younger members of the sample. We also find the IRAC 4.5 μm fluxes to be lower than expected, from which we infer a stronger CO fundamental band at ~4.67 μm. This suggests that equilibrium CH_4/CO chemistry underestimates the abundance of CO in T dwarf atmospheres, confirming earlier results based on M-band observations from the ground. In combining IRAC photometry with near-IR JHK photometry and parallax data, we find the combination of K_s, IRAC 3.6 μm, and 4.5 μm bands to provide the best color-color discrimination for a wide range of M, L, and T dwarfs. Also noteworthy is the M_k versus K_s-[4.5] relation, which shows a smooth progression over spectral type, and splits the M, L, and T types cleanly.
Proactive Postsales Service: When and Why Does It Pay Off?

Abstract Proactive postsales service (PPS) refers to a supplier taking the initiative to contact a customer to provide service after a sale is complete. It is argued that PPS leads to faster delivery of service to a broader cross-section of customers than customer-initiated postsales service, or reactive postsales service. The authors argue that mental frames of customers and suppliers engaged in PPS are more positive and open than mental frames of those engaged in customer-initiated service. On the basis of nine focus groups with 94 managers in both business-to-business and business-to-consumer settings, the authors propose three main dimensions of PPS: (1) proactive prevention, (2) proactive education, and (3) proactive feedback seeking. They argue that PPS leads not only to favorable customer-level outcomes (e.g., customer satisfaction) but also to favorable supplier-level outcomes (e.g., greater innovativeness, new product success rate). The authors propose that the value of PPS varies depending on th...
Covariant computation of the low-energy effective action of the heterotic superstring

We derive the low-energy effective action of the heterotic superstring in superspace. This is achieved by coupling the covariantly quantized Green-Schwarz superstring of Berkovits to a curved background and requiring that the sigma model has superconformal invariance at tree level and at one loop in α′. Tree level superconformal invariance yields the complete supergravity algebra, and one-loop superconformal invariance the equations of motion of the low energy theory. The resulting low-energy theory is old-minimal supergravity coupled to a tensor multiplet. The dilation is part of the compensator multiplet.
SECULAR EVOLUTION AND THE GROWTH OF PSEUDOBULGES IN DISK GALAXIES

Galactic evolution is in transition from an early universe dominated by hierarchical clustering to a future dominated by secular processes. These result from interactions involving collective phenomena such as bars, oval disks, spiral structure, and triaxial dark halos. A detailed review is in Kormendy & Kennicutt (2004). This paper provides a summary illustrated in part with different galaxies.
Hydrologic controls on coastal suspended sediment plumes around the Greenland Ice Sheet

Abstract. Rising sea levels and increased surface melting of the Greenland ice sheet have heightened the need for direct observations of meltwater release from the ice edge to ocean. Buoyant sediment plumes that develop in fjords downstream of outlet glaciers are controlled by numerous factors, including meltwater runoff. Here, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery is used to average surface suspended sediment concentration (SSC) in fjords around ∼80% of Greenland from 2000–2009. Spatial and temporal patterns in SSC are compared with positive-degree-days (PDD), a proxy for surface melting, from the Polar MM5 regional climate model. Over this decade significant geographic covariance occurred between ice sheet PDD and fjord SSC, with outlet type (land- vs. marine-terminating glaciers) also important. In general, high SSC is associated with high PDD and/or a high proportion of land-terminating glaciers. Unlike previous site-specific studies of the Watson River plume at Kangerlussuaq, temporal covariance is low, suggesting that plume dimensions best capture interannual runoff dynamics whereas SSC allows assessment of meltwater signals across much broader fjord environments around the ice sheet. Remote sensing of both plume characteristics thus offers a viable approach for observing spatial and temporal patterns of meltwater release from the Greenland ice sheet to the global ocean.
Non-Invasive Testing, Non-Invasive Counseling:

This article describes a new prenatal genetic test that is painless, early, and increasingly available. State legislatures have reacted by prohibiting abortion for reason of fetal sex or of fetal diagnosis and managing genetic counseling. This article explores these legislative responses and considers how physicians and genetic counselors currently communicate post-testing options. The article then examines the challenges ahead for genetic counseling, particularly in light of the troubling grip of abortion politics on conversations about prenatal diagnosis.
Problem Doctors: Is There a System-Level Solution?

Physician performance failures are not rare and pose substantial threats to patient welfare and safety. Few hospitals respond to such failures promptly or effectively. Failure to ensure the quality and safety of the performance of colleagues is a breach of medicine's fiduciary responsibility to the public. A major reason for this deficiency is the hospitals' lack of formal systems to monitor physician performance and to identify and correct shortcomings. To develop and implement these systems, hospitals need better performance measures and substantial expansion of external programs for assessment and remediation. This is a task well beyond the capacities of individual hospitals; a national effort is required. The authors call on the Federation of State Medical Boards, the American Board of Medical Specialties, and the Joint Commission on Accreditation of Healthcare Organizations (organizations that already bear a fiduciary responsibility for ensuring safe, competent care) to collaborate on developing better methods for measuring performance and to expand programs for helping practitioners who are deficient.
Proving probabilistic correctness statements: the case of Rabin's algorithm for mutual exclusion

The correctness of most randomized distributed algorithms is expressed by a statement of the form “some predicate of the executions holds with high probability, regardless of the order in which actions are scheduled“. In this paper, we present a general methodology to prove correctness statements of such randomized algorithms. Specifically, we show how to prove such statements by a series of refinements, which terminate in a statement independent of the schedule. To demonstrate the subtlety of the issue involved in this type of analysis, we focus on Rabin's randomized distributed algorithm for mutual exclusion [6].Surprisingly, it turns out that the algorithm does not maintain one of the requirements of the problem under a certain schedule. In particular, we give a schedule under which a set of processes can suffer lockout for arbitrary long periods.
Some Results on Combinators in the System TRC

We investigate the system TRC of untyped illative combinatory logic that is equiconsistent with New Foundations. We prove that various unstratified combinators do not exist in TRC.
The angular velocity of Nubia relative to Somalia and the location of the Nubia—Somalia–Antarctica triple junction

SUMMARY An ew analysis of geologically current plate motion across the Southwest Indian ridge (SWIR) and of the current location of the Nubia‐Antarctica‐Somalia triple junction is presented. Spreading rates averaged over the past 3.2 Myr are estimated from 103 well-distributed, nearly ridge-perpendicular profiles that cross the SWIR. All available bathymetric data are evaluated to estimate the azimuths and uncertainties of transform faults; six are estimated from multibeam data and 12 from precision depth recorder (PDR) data. If both the Nubian and Somalian component plates are internally rigid near the SWIR and if the Nubia‐Somalia boundary is narrow where it intersects the SWIR, that intersection lies between ≈26 ◦ E and ≈32 ◦ E. Thus, the boundary is either along the spreading ridge segment just west of the Andrew Bain transform fault complex (ABTFC) or along some of the transform fault complex itself. These limits are narrower than and contained within limits of ≈24 ◦ Et o≈33 ◦ E previously found by Lemaux et al. from an analysis of the locations of magnetic anomaly 5. The data are consistent with a narrow boundary, but also consistent with a diffuse boundary as wide as ≈700 km. The new Nubia‐Somalia pole of rotation lies ≈10 ◦ north of the Bouvet triple junction, which places it far to the southwest of southern Africa. The new angular velocity determined only from data along the SWIR indicates displacement rates of Somalia relative to Nubia of 3.6 ± 0.5 mm yr −1 (95 per cent confidence limits) towards 176 ◦ (S04 ◦ E) between Somalia and Nubia near the SWIR, and of 8.3 ± 1.9 mm yr −1 (95 per cent confidence limits) towards 121 ◦ (S59 ◦ E) near Afar. The new Nubia‐Somalia angular velocity differs significantly from the Nubia‐Somalia angular velocity estimated from Gulf of Aden and Red sea data. This significant difference has three main alternative explanations: (i) that the plate motion data have substantial unmodelled systematic errors, (ii) that the Nubian component plate is not a single rigid plate, or (iii) that the Somalian component plate is not a single rigid plate. We tentatively prefer the third explanation given the geographical distribution of earthquakes within the African composite plate relative to the inferred location of the Nubia‐Somalia boundary along the SWIR.
Pseudo-resonant full bridge DC/DC converter

A DC-DC power converter topology that combines the ease of control and wide range of conventional DC-DC converters, with low switching losses, low dv/dt and low electromagnetic interference that is typical of zero voltage switched resonant converters is proposed. Consequently, the ratings of these components are substantially lower than for similarly rated resonant topologies. While resonant elements are used to ensure zero voltage switching of all devices, they have little or no role in the actual power transfer and can thus be reasonably sized. As the resonant elements are not involved in the primary power transfer, the converter is referred to as a pseudo-resonant converter. It is shown that the converter offers significantly higher levels of performance than either the pulse width-modulated (PWM) or typical resonant converters. Operation at very high frequencies is possible and is shown with the fabrication of a 200 W 1 MHz DC-DC converter. >
A bulk power system reliability assessment methodology

This paper describes a methodology to evaluate the reliability of bulk power systems. The method encompasses the systematic enumeration of contingencies and the evaluation of their effects on the system over a range of system load levels. Contingencies and electric load states are described with Markov models. Reliability indices are computed using these models. Both adequacy and a simplified security approaches are considered in the effects analysis. The framework is capable of considering full security approach but it is not addressed in this paper. In adequacy approach, an improved system simulation method is used based on the single-phase quadratized power flow. Remedial actions are also applied for the purpose of alleviating abnormal conditions. This approach determines whether the system is adequate of supplying the electric load without operating constraint violations. In the simplified security approach, the immediate response of the system is of interest. The simulation approach consists of an inertial redispatch and operating conditions immediately after the contingency before any controls take effect. The objective is to determine whether cascading failures occur. The proposed methodology has been applied to two reliability test systems
Migration, Economic Opportunity, and the Quality of Life: Reply and Extension

This reply extends our previous study on migration by estimating a system of simultaneous equations by two stage least squares. This set of results implies even more strongly than our original study, which was a single-equation system estimated by ordinary least squares, that in-migration is positively impacted by both the prospects of a higher level of income and greater income growth on the one hand and by quality of life factors, including warm climate, on the other hand.
McKesson drug company-a case study of Economost: a strategic information system

The authors examine in detail McKesson's order entry and distribution system, Economost, which is one of the most widely cited strategic information systems, with wide acceptance; nearly 100% of McKesson's orders are entered electronically by customers. The impact on customers and on McKesson's costs has been both favorable and considerable. The authors describe the history of Economost and discuss its effect on McKesson and on the industry. >
Basel II: A Contracting Perspective

Financial safety nets are incomplete social contracts that assign responsibility to various economic sectors for preventing, detecting, and paying for potentially crippling losses at financial institutions. Basel II forces signatory countries to reopen safety-net bargaining across affected sectors. This paper uses the theories of incomplete contracts and sequential bargaining to interpret the Basel Accords as a framework for endlessly renegotiating minimal duties and standards of safety-net management across the community of nations. Modelling the stakes and stakeholders represented by different regulators helps us to understand that inconsistencies were bound to exist in prior understandings about the range of sectoral effects that the 2004 Basel II agreement might produce. The analysis seeks to explain why, in the U.S., attempting to resolve what turned out to be intolerable inconsistencies spawned an embarrassingly fractious debate and repeatedly pushed back Basel II’s scheduled implementation.
General Relativistic Magnetohydrodynamic Simulations of Black Hole Accretion Disks: Results and Observational Implications

A selection of results from the general relativistic MHD accretion simulations described in the previous talk are presented. We find that the magnetic field strength increases sharply with decreasing radius and is also enhanced near rapidly-spinning black holes. The greater magnetic field strength associated with rapid black hole rotation leads to a large outward electromagnetic angular momentum flux that substantially reduces both the mean accretion rate and the net accreted angular momentum per unit rest-mass. This electromagnetic stress strongly violates the traditional guess that the accretion stress vanishes at and inside the marginally stable orbit. Possible observational consequences include a constraint on the maximum spin of black holes, enhancement to the radiative efficiency, and concentration of fluorescent Fe Kα to the innermost part of the accretion disk.
Hierarchical QR Factorization Algorithms for Multi-core Cluster Systems

This paper describes a new QR factorization algorithm which is especially designed for massively parallel platforms combining parallel distributed multi-core nodes. %equipped with accelerators. These platforms make the present and the foreseeable future of high-performance computing. Our new QR factorization algorithm falls in the category of the tile algorithms which naturally enables good data locality for the sequential kernels executed by the cores (high sequential performance), low number of messages in a parallel distributed setting (small latency term), and fine granularity (high parallelism). Each tile algorithm is uniquely characterized by its sequence of reduction trees. In the context of a cluster of multicores, in order to minimize the number of inter-processor communications (aka, ``communication-avoiding'' algorithm), it is natural to consider two-level hierarchical trees composed of an ``inter-node'' tree which acts on top of ``intra-node'' trees. At the intra-node level, we propose a hierarchical tree made of three levels: (0) ``TS level'' for cache-friendliness, (1) ``low level'' for decoupled highly parallel inter-node reductions, (2) ``coupling level'' to efficiently resolve interactions between local reductions and global reductions. Our hierarchical algorithm and its implementation are flexible and modular, and can accommodate several kernel types, different distribution layouts, and a variety of reduction trees at all levels, both inter-cluster and intra-cluster. Numerical experiments on a cluster of multicore nodes (1) confirm that each of the four levels of our hierarchical tree contributes to build up performance and (2) build insights on how these levels influence performance and interact within each other. Our implementation of the new algorithm with the \Dague scheduling tool significantly outperforms currently available QR factorization softwares for all matrix shapes, thereby bringing a new advance in numerical linear algebra for petascale and exascale platforms.
Agarose Gel Electrophoresis

Agarose gel electrophoresis is a simple and highly effective method for separating, identifying, and purifying 0.5- to 25-kb DNA fragments. The protocol can be divided into three stages: (1) a gel is prepared with an agarose concentration appropriate for the size of DNA fragments to be separated; (2) the DNA samples are loaded into the sample wells and the gel is run at a voltage and for a time period that will achieve optimal separation; and (3) the gel is stained or, if ethidium bromide has been incorporated into the gel and electrophoresis buffer, visualized directly upon illumination with UV light.
Optical network design to minimize switching and transceiver equipment costs

We consider a network consisting of N nodes and a certain number of links M that could be used to interconnect these nodes. The problem we address is to determine the smallest subset of switching nodes (in which to provide optical or electronic switching capability) necessary and sufficient to provide full end-to-end connectivity among all nodes. It is shown that this selection leads to the minimum number of transceivers needed to achieve full connectivity. We then address the same problem with the additional requirement of survivability, whereby the failure of any one link does not lead to any disconnection in the network. To solve the above stated problems, we employ heuristic and optimal algorithms; we find that the minimum number of switching sites is well estimated as a function of a single parameter, the network connectivity @a=2MN(N-1). (This is an extended version of the paper presented at Broadnets 2006.)
Reliable cellular automata with self-organization

In a noisy cellular automaton, even if it is infinite, it is non-trivial to keep a bit of information for more than a constant number of steps. A clever solution in 2 dimensions has been applied to a simple 3-dimensional fault-tolerant cellular automaton. This technique did not solve the following problems: remembering a bit of information in 1 dimension; computing in dimensions lower than 3, or with non-synchronized transitions. With a more complex technique using a hierarchy of simulations, we construct an asynchronous one-dimensional reliable cellular automaton, which is also "self-organizing". This means that if the input information has constant size, the initial configuration can be homogenous: the hierarchy organizes itself. An application to information storage in positive-temperature Gibbs states is also given.
Cross-Market Discounts

Firms in several markets attract consumers by offering discounts in other unrelated markets. This promotion strategy, which we call “cross-market discounts,” has been successfully adopted in the last few years by many grocery retailers in partnership with gasoline retailers across North America, Europe, and Australia. In this paper, we use an analytical model to investigate the major forces driving the profitability of this novel promotion strategy. We consider a generalized scenario in which purchases in a source market lead to price discounts redeemable in a target market. Our analysis shows that this strategy can be a revenue driver by simultaneously increasing prices as well as sales in the source market, even though we assume the demand curve to be downward sloping in price. Moreover, it distributes additional consumption (motivated by the discount) in two markets, and under diminishing marginal returns from consumption, this can simultaneously increase firm profits and consumer welfare more effectively than traditional nonlinear pricing strategies. Our study provides many other interesting insights as well, and our key results are in accordance with anecdotal evidence obtained from managers and industry publications.
Calculation of the minimum number of replicate spots required for detection of significant gene expression fold change in microarray experiments

Motivation: We present statistical methods for determining the number of per gene replicate spots required in microarray experiments. The purpose of these methods is to obtain an estimate of the sampling variability present in microarray data, and to determine the number of replicate spots required to achieve a high probability of detecting a significant fold change in gene expression, while maintaining a low error rate. Our approach is based on data from control microarrays, and involves the use of standard statistical estimation techniques. Results: After analyzing two experimental data sets containing control array data, we were able to determine the statistical power available for the detection of significant differential expression given differing levels of replication. The inclusion of replicate spots on microarrays not only allows more accurate estimation of the variability present in an experiment, but more importantly increases the probability of detecting genes undergoing significant fold changes in expression, while substantially decreasing the probability of observing fold changes due to chance rather than true differential expression. Availability: The methods presented here are based on standard techniques, and are available in most statistical software packages. We used the software R to perform the computations for this work.
When can you fold a map

We explore the following problem: given a collection of creases on a piece of paper, each assigned a folding direction of mountain or valley, is there a fiat folding by a sequence of simple folds? There are several models of simple folds; the simplest one-layer simple fold rotates a portion of paper about a crease in the paper by ±180°. We first consider the analogous questions in one dimension lower--bending a segment into a flat object--which lead to interesting problems on strings. We develop efficient algorithms for the recognition of simply foldable 1D crease patterns, and reconstruction of a sequence of simple folds. Indeed, we prove that a 1D crease pattern is flat-foldable by any means precisely if it is by a sequence of one-layer simple folds. Next we explore simple foldability in two dimensions, and find a surprising contrast: "map" folding and variants are polynomial, but slight generalizations are NP-complete. Specifically, we develop a linear-time algorithm for deciding foldability of an orthogonal crease pattern on a rectangular piece of paper, and prove that it is (weakly) NP-complete to decide foldability of (1) an orthogonal crease pattern on a orthogonal piece of paper, (2) a crease pattern of axis-parallel and diagonal (45-degree) creases on a square piece of paper, and (3) crease patterns without a mountain/valley assignment.
From chiral random matrix theory to chiral perturbation theory

Abstract We study the spectrum of the QCD Dirac operator by means of the valence quark mass dependence of the chiral condensate in partially quenched Chiral Perturbation Theory (pqChPT) in the supersymmetric formulation of Bernard and Golterman. We consider valence quark masses both in the ergodic domain (mν ⪡ Ec) and the diffusive domain (mν ⪢ Ec). These domains are separated by a mass scale Ec ∼ F2/Σ0L2 (with F the pion decay constant, Σ0 the chiral condensate and L the size of the box). In the ergodic domain the effective super-Lagrangian reproduces the microscopic spectral density of chiral Random Matrix Theory (chRMT). We obtain a natural explanation of Damgaard's relation between the spectral density and the finite volume partition function with two additional flavors. We argue that in the ergodic domain the natural measure for the superunitary integration in the pqChPT partition function is non-compact. We find that the tail of the two-point spectral correlation function derived from pqChPT agrees with the chRMT result in the ergodic domain. In the diffusive domain we extend the results for the slope of the Dirac spectrum first obtained by Smilga and Stern. We find that the spectral density diverges logarithmically for non-zero topological susceptibility. We study the transition between the ergodic and the diffusive domains and identify a range where chRMT and pqChPT coincide.
The Texture of Hardship: Qualitative Sociology of Poverty, 1995–2005

Focusing on the past decade, this review considers advances in the qualitative study of working poverty, welfare reform, patterns of family formation, neighborhood effects, class-based patterns of childhood socialization, and the growing European literature on social exclusion. We highlight the increasing importance of qualitative research embedded in large-scale quantitative studies of poverty. Within each of these areas, we suggest new directions for research that take into account the changing contours of poverty, including the increasing diversity of poor neighborhoods (reflecting the in-migration of the foreign born) and the growth of poverty in the older suburbs surrounding the city centers. The reintroduction of the language of class has been a hallmark of the past decade, drawing it closer to some of the original concerns of sociologists in the 1940s, contrasted with a nearly universal emphasis on race and ethnicity characteristic of more recent decades.
Terminal olefins to linear α,β-unsaturated ketones: Pd(II)/hypervalent iodine co-catalyzed Wacker oxidation-dehydrogenation.

Development of a mild (35 °C, no Bronsted acids) tandem Wacker oxidation–dehydrogenation of terminal olefins was accomplished using palladium(II) and hypervalent iodine co-catalysis. The reaction affords linear aryl and alkyl α,β-unsaturated ketones directly from readily available terminal olefins in good yields (average 75% per step) with excellent functional group tolerance and chemo- and stereoselectivities. The hypervalent iodine co-catalyst was found to be critical for dehydrogenation but was not effective as a stoichiometric oxidant.
Complications of Acute Respiratory Failure

Acute respiratory failure is frequently fatal. Attempts to decrease mortality must include attention to pulmonary and extrapulmonary complications. Pulmonary complications include pulmonary emboli, barotrauma, fibrosis, and pneumonia. Swan-Ganz catheters, tracheal intubation, and mechanical ventilation can also result in pulmonary complications. Extra-pulmonary complications such as gastrointestinal hemorrhage, renal failure, infection, and thrombocytopenia may increase mortality. Early diagnosis, aggressive treatment, and prophylaxis of complications should increase survival.
Our Troubled Health Care System: Why Is It So Hard to Fix?

This brief draws heavily on Judith Feder, 2004, "Crowd-Out and the Politics of Health Reform," The Journal of Law, Medicine, and Ethids 32(3): 461-464. We all know that affordable health care is now back on the political agenda, and it's about time! Because all of us - families, businesses, and governments--are struggling with the ever-increasing costs of care. Every year about a million people are added to the rolls of the uninsured. In 2006, it was even more, over 2 million. The number of people without health insurance coverage has reached more than 47 million. People *with* insurance are seeing their benefits dwindle and their health care costs consume their wabes. Even people with health insurance find themselves unable to pay their medical bills and going without needed care. The bottom line is that, increasingly, our health insurance system fails to protect us when we get sick.
A conjugate gradient-based algorithm to minimize the sidelobe level of planar arrays with element failures

Element failures increase the sidelobe power level of an array. Reconfiguring the amplitude and phase distribution of the remaining elements can partially compensate for the failed elements and thus reduce the sidelobe level. An algorithm is obtained that yields the reconfigured distribution by minimizing the ratio of the average peak sidelobe power level to the power in the main beam, taking into account the defective elements. The minimization of this nonlinear function is carried out via a conjugate gradient method. The algorithm is applied to the synthesis of sum and difference patterns of planar arrays. >
EvoGrader: an online formative assessment tool for automatically evaluating written evolutionary explanations

EvoGrader is a free, online, on-demand formative assessment service designed for use in undergraduate biology classrooms. EvoGrader’s web portal is powered by Amazon’s Elastic Cloud and run with LightSIDE Lab’s open-source machine-learning tools. The EvoGrader web portal allows biology instructors to upload a response file (.csv) containing unlimited numbers of evolutionary explanations written in response to 86 different ACORNS (Assessing COntextual Reasoning about Natural Selection) instrument items. The system automatically analyzes the responses and provides detailed information about the scientific and naive concepts contained within each student’s response, as well as overall student (and sample) reasoning model types. Graphs and visual models provided by EvoGrader summarize class-level responses; downloadable files of raw scores (in .csv format) are also provided for more detailed analyses. Although the computational machinery that EvoGrader employs is complex, using the system is easy. Users only need to know how to use spreadsheets to organize student responses, upload files to the web, and use a web browser. A series of experiments using new samples of 2,200 written evolutionary explanations demonstrate that EvoGrader scores are comparable to those of trained human raters, although EvoGrader scoring takes 99% less time and is free. EvoGrader will be of interest to biology instructors teaching large classes who seek to emphasize scientific practices such as generating scientific explanations, and to teach crosscutting ideas such as evolution and natural selection. The software architecture of EvoGrader is described as it may serve as a template for developing machine-learning portals for other core concepts within biology and across other disciplines.
A Robust Robust Optimization Result

We study the loss in objective value when an inaccurate objective is optimized instead of the true one, and show that “on average” this loss is very small, for an arbitrary compact feasible region.
Square integrable holomorphic functions on infinite-dimensional Heisenberg type groups

We introduce a class of non-commutative, complex, infinite-dimensional Heisenberg like Lie groups based on an abstract Wiener space. The holomorphic functions which are also square integrable with respect to a heat kernel measure μ on these groups are studied. In particular, we establish a unitary equivalence between the square integrable holomorphic functions and a certain completion of the universal enveloping algebra of the “Lie algebra” of this class of groups. Using quasi-invariance of the heat kernel measure, we also construct a skeleton map which characterizes globally defined functions from the L2(ν)-closure of holomorphic polynomials by their values on the Cameron–Martin subgroup.
Micromachined millimeter-wave SIS-mixers

Micromachined SIS-mixers for 90-115 GHz and for 180-230 GHz have been fabricated and tested. A micromachined SIS-mixer consists of an antenna-coupled superconducting tunnel junction fabricated on a thin SiN membrane which is placed inside a pyramidal horn structure. The horn is formed by anisotropic KOH-etching of [100] Si along the (111) crystal planes. The high accuracy of the etching and the ease of whole-wafer fabrication make this type of SIS mixers attractive for applications both at high frequencies and in imaging arrays. Experimental results show that high-quality tunnel junctions can be reliably fabricated on thin SiN membranes. Experiments also show that the junctions are adequately cooled on the membrane and that sufficient LO-power can be coupled. >
Geographic routing in the presence of location errors

In this paper, we propose a new geographic routing algorithm that alleviates the effect of location errors on routing in wireless ad hoc networks. In most previous work, geographic routing has been studied assuming perfect location information. However, in practice there could be significant errors in obtaining location estimates, even when nodes use GPS. Hence, existing geographic routing schemes will need to be appropriately modified. We investigate how such location errors affect the performance of geographic routing strategies. We incorporate location errors into our objective function by considering both transmission failures and backward progress. Each node then forwards packets to the node that maximizes this objective function. We call this strategy "Maximum Expectation within transmission Range" (MER). Simulation results with MER show that accounting for location errors significantly improves the performance of geographic routing. Our analysis also shows that our algorithm works well up to a critical threshold of error. We also show that MER is robust to the location error model and model parameters. Further, via simulations, we show that in a mobile environment MER performs better than existing approaches.
Higher-Degree Analogs of the Determinant Line Bundle

In the first part of this paper, given a smooth family of Dirac-type operators on an odd-dimensional closed manifold, we construct an abelian gerbe-with-connection whose curvature is the three-form component of the Atiyah-Singer families index the- orem. In the second part of the paper, given a smooth family of Dirac-type operators whose index lies in the subspace � ∗ (B) of the reduced K-theory of the parametrizing space, we construct a set of Deligne cohomology classes of degree i whose curvatures are the i-form component of the Atiyah-Singer families index theorem.