cssi/SciSciGPT-SciSciNet huggingface dataset:
Export Destinations and Input Prices

This paper examines the extent to which the destination of exports matters for the input prices paid by firms, using detailed customs and firm-product-level data from Portugal. The authors use exchange rate movements as a source of variation in export destinations and find that exporting to richer countries leads firms to charge more for outputs and pay higher prices for inputs, other things equal. The results are supportive of the hypothesis that an exogenous increase in average destination income leads firms to raise the average quality of goods they produce and to purchase higher-quality inputs.
Bayesian Algorithms for Causal Data Mining

We present two Bayesian algorithms CD-B and CD-H for discovering unconfounded cause and effect relationships from observational data without assuming causal sufficiency which precludes hidden common causes for the observed variables. The CD-B algorithm first estimates the Markov blanket of a node X using a Bayesian greedy search method and then applies Bayesian scoring methods to discriminate the parents and children of X. Using the set of parents and set of children CD-B constructs a global Bayesian network and outputs the causal effects of a node X based on the identification of Y arcs. Recall that if a node X has two parent nodes A,B and a child node C such that there is no arc between A,B and A,B are not parents of C, then the arc from X to C is called a Y arc. The CD-H algorithm uses the MMPC algorithm to estimate the union of parents and children of a target node X. The subsequent steps are similar to those of CD-B. We evaluated the CD-B and CD-H algorithms empirically based on simulated data from four different Bayesian networks. We also present comparative results based on the identification of Y structures and Y arcs from the output of the PC, MMHC and FCI algorithms. The results appear promising for mining causal relationships that are unconfounded by hidden variables from observational data.
The Forgotten History of Domestic Debt

There is a rich scholarly literature on sovereign default on external debt. Comparatively little is known about sovereign default on domestic debt. Even today, cross-country data on domestic public debt remains curiously exotic, particularly prior to the 1980s. We have filled this gap in the literature by compiling a database on central government public debt (external and domestic). The data span 1914 to 2010 for most countries, reaching back into the nineteenth century (and earlier) for many. Our findings here on debt sustainability, sovereign defaults, the temptation to inflate, and the hierarchy of creditors only scratch the surface of what the domestic public debt data can reveal. First, domestic debt is big—for the 64 countries for which we have long time series, domestic debt accounts for almost two-thirds of total public debt. For most of the sample, this debt carries a market-determined interest rate (except for the financial repression era between WWII and financial liberalization). Second, the data go a long way toward explaining the puzzle of why countries so often default on their external debts at seemingly low debt thresholds. Third, domestic debt has largely been ignored in the vast empirical work on inflation. In fact, domestic debt (a significant portion of which is long term and nonindexed) is often much larger than the monetary base in the run-up to high-inflation episodes. Last, the widely held view that domestic residents are strictly junior to external creditors does not find broad support.
Singular cardinals and strong extenders

We investigate the circumstances under which there exist a singular cardinal µ and a short (κ,µ)-extender E witnessing “κ is µ-strong”, such that µ is singular in Ult(V, E).
An analysis of phase synchronization mismatch sensitivity for coherent MIMO radar systems

In this study, the hybrid Cramer-Rao bound (CRB) is developed for target localization, to establish the sensitivity of the estimation mean-square error (MSE) to the level of phase synchronization mismatch in coherent Multiple-Input Multiple-Output (MIMO) radar systems with widely distributed antennas. The lower bound on the MSE is derived for the joint estimation of the vector of unknown parameters, consisting of the target location and the mismatch of the allegedly known system parameters, i.e., phase offsets at the radars. Synchronization errors are modeled as being random and Gaussian. A closed-form expression for the hybrid CRB is derived for the case of orthogonal waveforms. The bound on the target localization MSE is expressed as the sum of two terms, the first represents the CRB with no phase mismatch, and the second captures the mismatch effect. The latter is shown to depend on the phase error variance, the number of mismatched transmitting and receiving sensors and the system geometry. For a given phase synchronization error variance, this expression offers the means to analyze the achievable localization accuracy. Alternatively, for a predetermined localization MSE target value, the derived expression may be used to determine the necessary phase synchronization level in the distributed system.
A Bayesian sampling approach to exploration in reinforcement learning

We present a modular approach to reinforcement learning that uses a Bayesian representation of the uncertainty over models. The approach, BOSS (Best of Sampled Set), drives exploration by sampling multiple models from the posterior and selecting actions optimistically. It extends previous work by providing a rule for deciding when to re-sample and how to combine the models. We show that our algorithm achieves near-optimal reward with high probability with a sample complexity that is low relative to the speed at which the posterior distribution converges during learning. We demonstrate that BOSS performs quite favorably compared to state-of-the-art reinforcement-learning approaches and illustrate its flexibility by pairing it with a non-parametric model that generalizes across states.
Grossman–Hart (1986) Goes Global: Incomplete Contracts, Property Rights, and the International Organization of Production

I survey the influence of Grossman and Hart's (1986. "The Costs and Benefits of Ownership: A Theory of Vertical and Lateral Integration," 94 Journal of Political Economy 691–719.) seminal paper in the field of International Trade. I discuss the implementation of the theory in open-economy environments and its implications for the international organization of production and the structure of international trade flows. I also review empirical work suggestive of the empirical relevance of the property-rights theory. Along the way, I develop novel theoretical results and also outline some of the key limitations of existing contributions. (JEL D23, F10, F12, F14, F21, F23, L22, L23).
Quantum teleportation of an arbitrary superposition of atomic Dicke states

We propose a scheme for teleporting an arbitrary superposition of entangled Dicke states of any number of atoms (qubits) between two distant cavities. Our method relies on adiabatic passage using multi-atom dark states in each cavity, and a conditional detection of photons leaking out of both cavities. The ideal success probability of the protocol decreases polynomially in the number of atoms. The fidelity is unity for a single Dicke state, and can be optimized for the superposition by unitary postprocessing. Issues of experimental feasibility and applications to quantum informatics are discussed.
Optimal preview-based stable-inversion for output tracking of nonminimum-phase linear systems

In this article, a new approach for output tracking of nonminimum-phase systems is proposed The proposed approach extends the preview-based stable inversion technique which utilizes the finite-previewed (in time) future desired trajectory to find the feedforward input (called inverse input) to achieve precision output-tracking of nonminimum-phase systems. It has been shown that the error in the inverse input can be rendered arbitrarily small provided the preview time is large enough Exact-output-tracking can be achieved if the entire future desired trajectory is known (i.e., the preview time extends to infinity). Therefore, having a large enough preview time is important to ensure the precision in the preview-based inverse input. The available preview time can be increased by using more powerful sensors. Or, alternatively, the need for preview time can be reduced by redesigning the trajectory, the system, or by using path following techniques. However, the available preview time is limited by physical constraints in applications such as active noise control. More generally, the available preview time is limited because of the associated cost and/or hardware limit. Therefore, we propose, in this article, the integration of optimal control with the preview- based stable-inversion to optimally exploit the available preview time. Specifically, we aim at obtaining the optimal preview- based inverse input by minimizing, within the preview time window, the predicted tracking error (under the preview-based inverse input) over the input energy. The properties of the optimal preview-based stable-inversion are discussed.
THE SEARCH FOR STABLE, MASSIVE, ELEMENTARY PARTICLES

In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches — what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review.
Photon-assisted transmission through a double-barrier structure

We study multiphoton-assisted transmission of electrons through single-step, single-barrier and double-barrier potential-energy structures as a function of the photon energy and the temperature. Sharp resonances are obtained for the spectra of the tunneling current and are relevant to infrared detectors.
Economic Growth and the Environment: A Review of Theory and Empirics.

Abstract The relationship between economic growth and the environment is, and will always remain, controversial. Some see the emergence of new pollution problems, the lack of success in dealing with global warming and the still rising population in the Third World as proof positive that humans are a short-sighted and rapacious species. Others however see the glass as half full. They note the tremendous progress made in providing urban sanitation, improvements in air quality in major cities and marvel at the continuing improvements in the human condition made possible by technological advance. The first group focuses on the remaining and often serious environmental problems of the day; the second on the long, but sometimes erratic, history of improvement in living standards. These views are not necessarily inconsistent and growth theory offers us the tools needed to explore the link between environmental problems of today and the likelihood of their improvement tomorrow. This review articles discusses and evaluates the theoretical literature linking environmental quality to economic growth. We focus on three questions. These are: (1) what is the relationship between economic growth and the environment? (2) how can we escape the limits to growth imposed by environmental constraints? and (3) where should future research focus its efforts? For the most part, we discuss the link between industrial pollution and growth, but also show how this most recent work is related to earlier contributions on exhaustible resources and growth. While no review can settle the perennial debate over the limits to growth, this review moves the literature forward by identifying important unresolved theoretical questions, reports on the results of recent empirical work, and provides an integrative assessment of where we stand today.
Biomimetic Total Syntheses of (−)‐Leucoridines A and C through the Dimerization of (−)‐Dihydrovalparicine

Concise biomimetic syntheses of the Strychnos-Strychnos-type bis-indole alkaloids (-)-leucoridine A (1) and C (2) were accomplished through the biomimetic dimerization of (-)-dihydrovalparicine (3). En route to 3, the known alkaloids (+)-geissoschizoline (8) and (-)-dehydrogeissoschizoline (10) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza-Michael/spirocyclization sequence over the alternate hetero-Diels-Alder cycloaddition reaction.
An efficient procedure for preparation of C- and N-protected 1-aminocyclobutane carboxylic acid

Abstract An efficient method for the synthesis of differentially protected 1‐aminocyclobutane carboxylic acid is described. Synthetically useful intermediates 7 and 8 were prepared from ethyl 1‐bromocyclobutanecarboxylate in excellent yields (95% and 69%, respectively).
Highly chemoselective oxidation of 1,5-diols to δ-lactones with TEMPO/BAIB

Abstract The selective oxidative conversion of a variety of highly functionalized 1°,2°-1,5-diols into the corresponding δ-lactones has been effected simply and efficiently using a reagent system comprised of catalytic 2,2,6,6-tetrmethylpiperidinooxy (TEMPO) and excess bis-acetoxyiodobenzene (BAIB).
Impact of Target-Material Activation on Personnel Exposure and Radioactive Contamination in the National Ignition Facility

Detailed activation analyses are performed for the different materials under consideration for use in the target capsules and hohlraums during the ignition campaign of the National Ignition Facility (NIF). Results of the target-material activation are additionally used to estimate the levels of contamination within the NIF Target Chamber (TC) and the workplace controls that are necessary for safe operation. The analysis examined the impact of using Be-Cu and Ge-doped hydrocarbon capsules on the external dose received by workers during maintenance activities. Five days following a 20-MJ shot, dose rates inside the TC due to the two proposed capsule materials are small (~ 0.01 ?Sv/h). Gold and depleted uranium (DU) are considered as potential hohlraum materials. Following a shot, gold will be deposited on the TC first wall. On the other hand, while noble-gas precursors from the DU are expected to stay in the TC, most of the noble gases are pumped out of the chamber and end up on the cryopumps. The dose rates inside the TC due to activated gold or DU, at five days following a 20-MJ shot, are about 10 ?Sv/h. Dose rates in the vicinity of the cryopumps (containing noble ?fission? gases) drop off to about 10 ?Sv/h during the first 12 h following the shot. Contamination from activation of NIF targets will result in levels in the NIF TC above U.S. Department of Energy surface contamination limits. Objects removed from the TC will need to be managed as radioactive material. However, the results suggest that airborne contamination from resuspension of surface contamination will not be significant and is at levels that can be readily managed by negative ventilation when accessing the TC attachments.
Quickest Change Detection of a Markov Process Across a Sensor Array

Recent attention in quickest change detection in the multisensor setting has been on the case where the densities of the observations change at the same instant at all the sensors due to the disruption. In this work, a more general scenario is considered where the change propagates across the sensors, and its propagation can be modeled as a Markov process. A centralized, Bayesian version of this problem is considered, with a fusion center that has perfect information about the observations and a priori knowledge of the statistics of the change process. The problem of minimizing the average detection delay subject to false alarm constraints is formulated in a dynamic programming framework. Insights into the structure of the optimal stopping rule are presented. In the limiting case of rare disruptions, it is shown that the structure of the optimal test reduces to thresholding the a posteriori probability of the hypothesis that no change has happened. Under a certain condition on the Kullback-Leibler (K-L) divergence between the post- and the pre-change densities, it is established that the threshold test is asymptotically optimal (in the vanishing false alarm probability regime). It is shown via numerical studies that this low-complexity threshold test results in a substantial improvement in performance over naive tests such as a single-sensor test or a test that incorrectly assumes that the change propagates instantaneously.
Sterile Endophthalmitis after Intravitreal Triamcinolone: A Possible Association with Uveitis

Purpose To report an association between uveitis and sterile endophthalmitis after intravitreal triamcinolone acetonide injection. Design Retrospective case series. Methods A retrospective analysis of all patients receiving intravitreal triamcinolone injection at the Cole Eye Institute from January 2006 through September 2006 was carried out to evaluate for the occurrence of bacterial or sterile endophthalmitis. Indication for treatment, ocular history, best-corrected Snellen visual acuity, and clinical examination findings were recorded from the clinical charts before injection and at last follow-up. Results A total of 310 eyes received intravitreal triamcinolone injection for various causes, including age-related macular degeneration (AMD), diabetic retinopathy, vascular occlusion, and cystoid macular edema (CME) resulting from uveitis. There were no cases of culture-positive infectious endophthalmitis. There were six cases (1.9%) of sterile endophthalmitis. Of these six cases, four had prior history of uveitis, whereas only 20 of the 310 cases had a prior history of uveitis. All six patients sought treatment within three days of injection, and all recovered rapidly. Presenting visual acuity was either counting fingers or hand movements. Median best-corrected visual acuity before injection was 20/100 + , whereas median final visual acuity was 20/80 − . Conclusions Patients with a history of uveitis may be at increased risk of experiencing sterile endophthalmitis resulting from intravitreal triamcinolone injection.
Efficient state classification of finite-state Markov chains

This paper presents an efficient method for state classification of finite-state Markov chains using binary-decision diagram-based symbolic techniques. The method exploits the fundamental properties of a Markov chain and classifies the state space by iteratively applying reachability analysis. We compare our method with the state-of-the-art technique, which requires the transitive closure of the transition relation of a Markov chain. Experiments in over a dozen synchronous and asynchronous systems and queueing networks demonstrate that our method dramatically reduces the CPU time needed and solves much larger problems because of the reduced memory requirements.
A General Concept and Algorithm of Projected DGPS for High‐Accuracy DGPS‐Based Systems

: Typical high-accuracy relative differential GPS (DGPS) solutions define single differences (SDs) based on the assumption that the unit vectors from both the reference and user sites to the satellite are parallel. However, the parallel assumption is challenged by the nonlinearity problem in augmented DGPS and long-baseline high-accuracy DGPS systems. This paper proposes the general concept of Projected DGPS (PDGPS) to effectively remove the nonlinear geometry bias in a closed-form solution. PDGPS is applicable not only to augmented high-accuracy positioning applications using auxiliary ranging sources (ARS), such as low earth-orbiting satellites (LEOs) and earth-bound pseudolites (PLs), but also to medium- and long-baseline applications using medium earth-orbiting satellites (MEOs). Simulation results and real-data test results are presented. The conclusion is drawn that PDGPS significantly improves the resolution performance of high-accuracy DGPS-based systems in terms of simplicity, accuracy, and reliability.
Ambient temperature synthesis of polycrystalline thin films of lithium cobalt oxide with controlled crystallites † orientations

Polycrystalline thin films of lithium cobalt oxide (nominally LiCo0 2 ) have been deposited by a process which we have named, ion beam directed assembly (IBDA). It is similar to ion assisted deposition (IAD) or ion beam assisted deposition (IBAD), but the major difference is that in IBDA the ion beam directs, via the vector momenta of the ions, rather than merely assists, the growth. Hence, we also term the process directed assembly to distinguish it from self assembly. Also, in directed assembly the ions may or may not become an integral part of the film's composition. In this paper we wish to show that the IBDA process may be capable of controlling microstructure, e.g., in the case of polycrystalline films, control the orientations of the crystallites. For LiCoO 2 we have observed this in two ways - by X-ray analysis, and electrochemically, by lithium diffusivity measurements. In particular, we have observed increased lithium diffusivities (≥ 10 −8 cm 2/s) in IBDA deposited films as compared to that found for rf sputter deposited films (z 10 −10 cm 2 /s). In addition, the coulometric titration characteristics of an IBDA deposited Li l−y CoO 2 are very similar to those of sputtered deposited films (for lithium extraction/insertion, y ≤0.5, and for quasi-equilibrium voltages up to 4.2 volts).
On the Achievable Throughput Region of Multiple-Access Fading Channels with QoS Constraints

Effective capacity, which provides the maximum constant arrival rate that a given service process can support while satisfying statistical delay constraints, is analyzed in a multiuser scenario. In particular, we study the achievable effective capacity region of the users in multiaccess fading channels (MAC) in the presence of quality of service (QoS) constraints. We assume that channel side information (CSI) is available at both the transmitters and the receiver, and superposition coding technique with successive decoding is used. When the power is fixed at the transmitters, we show that varying the decoding order with respect to the channel state can significantly increase the achievable throughput region. For a two-user case, we obtain the optimal decoding strategy when the users have the same QoS constraints. Meanwhile, it is shown that time-division multiple-access (TDMA) can achieve better performance than superposition coding with fixed successive decoding order at the receiver side for certain QoS constraints. For power and rate adaptation, we determine the optimal power allocation policy with fixed decoding order at the receiver side. Numerical results are provided to demonstrate our results.
Comparative studies of chemotherapy of human tumor cells in vitro by tritiated thymidine uptake inhibition and soft agar clonogenic assay

A rapid nonsterile short-term assay has been investigated in which percent inhibition of incorporation of the DNA precursor (3H)-thymidine is measured following exposure of tumor cells to the test drugs. To evaluate the usefulness of the short-term assay in providing a rapid reliable assessment of chemotherapeutic response, the short-term assay was compared with the soft agar clonogenic assay. Sensitivity to five anticancer drugs was compared using three human tumor cell lines (epidermoid carcinoma of the oral cavity, pancreatic carcinoma, and bladder carcinoma). The short-term assay produced results that were similar to results of the clonogenic assay in two of the three tumors tested, for three drugs (cis-platin, doxorubicin, and BCNU), but did not detect responses to two antimetabolites (5-FU and MTX) in any tumor. Further studies of this short-term assay should focus on alkylating agents and other nonantimetabolites.
Involvement of Histone Methylation and Phosphorylation in Regulation of Transcription by Thyroid Hormone Receptor

Previous studies have established an important role of histone acetylation in transcriptional control by nuclear hormone receptors. With chromatin immunoprecipitation assays, we have now investigated whether histone methylation and phosphorylation are also involved in transcriptional regulation by thyroid hormone receptor (TR). We found that repression by unliganded TR is associated with a substantial increase in methylation of H3 lysine 9 (H3-K9) and a decrease in methylation of H3 lysine 4 (H3-K4), methylation of H3 arginine 17 (H3-R17), and a dual modification of phosphorylation of H3 serine 10 and acetylation of lysine 14 (pS10/acK14). On the other hand, transcriptional activation by liganded TR is coupled with a substantial decrease in both H3-K4 and H3-K9 methylation and a robust increase in H3-R17 methylation and the dual modification of pS10/acK14. Trichostatin A treatment results in not only histone hyperacetylation but also an increase in methylation of H3-K4, increase in dual modification of pS10/acK14, and reduction in methylation of H3-K9, revealing an extensive interplay between histone acetylation, methylation, and phosphorylation. In an effort to understand the underlying mechanism for an increase in H3-K9 methylation during repression by unliganded TR, we demonstrated that TR interacts in vitro with an H3-K9-specific histone methyltransferase (HMT), SUV39H1. Functional analysis indicates that SUV39H1 can facilitate repression by unliganded TR and in so doing requires its HMT activity. Together, our data uncover a novel role of H3-K9 methylation in repression by unliganded TR and provide strong evidence for the involvement of multiple distinct histone covalent modifications (acetylation, methylation, and phosphorylation) in transcriptional control by nuclear hormone receptors.
Trigonometric S matrices, affine Toda solitons and supersymmetry

Using - and -invariant R matrices we construct exact S matrices in two-dimensional space–time. These are conjectured to describe the scattering of solitons in affine Toda field theories. In order to find the spectrum of soliton bound states we examine the pole structure of these S matrices in detail. We also construct the S matrices for all scattering processes involving scalar bound states. In the last part of this paper we discuss the connection of these S matrices with minimal N=1 and N = 2 super-symmetric S matrices. In particular we comment on the folding from N = 2 to N = 1 theories.
Electrochemical and Photoelectrochemical Properties of the Copper Hydroxyphosphate Mineral Libethenite

There has been much interest recently in the discovery of new, non-oxide materials for photoelectrochemical applications. The copper hydroxyphosphate mineral libethenite, Cu2(OH)PO4 (CHP), which has a Jahn-Teller distorted structure and d 9 electron configuration, has recently been reported to display photocatalytic activity. To better understand the properties of this material, a detailed investigation of the relevant fundamental characteristics such as the flatband potential, conduction type, and band diagram was performed using electrochemical and photoelectrochemical methods on thin films deposited on fluorine-doped tin oxide (FTO) substrates. Density functional theory was used to calculate the band structure, effective mass of electrons and holes, and vacancy formation energies in CHP. CHP was found to be active for electrochemical water oxidation, as confirmed by quantitative O2 measurements. Possible factors behind the low photocurrents observed in linear scanning voltammetry are discussed. Better understanding of this material may lead to the development of improved catalysts and photocatalysts from natural mineral sources.
Markov chain existence and Hidden Markov models in spectrum sensing

The primary function of a cognitive radio is to detect idle frequencies or sub-bands, not used by the primary users (PUs), and allocate these frequencies to secondary users. The state of the sub-band at any time point is either free (unoccupied by a PU) or busy (occupied by a PU). The states of a sub-band are monitored over L consecutive time periods, where each period is of a given time interval. Existing research assume the presence of a Markov chain for sub-band utilization by PUs over time, but this assumption has not been validated. Therefore, in this paper we validate existence of a Markov chain for sub-band utilization using real-time measurements collected in the paging band (928–948 MHz). Furthermore, since the detection of idle sub-bands by a cognitive radio is prone to errors, we probabilistically model the errors and then formulate a spectrum sensing paradigm as a Hidden Markov model that predicts the true states of a sub-band. The accuracy of our proposed method in predicting the true states of the sub-band is substantiated using extensive simulations.
Use of devolved controllers in data center networks

In a data center network, for example, it is quite often to use controllers to manage resources in a centralized manner. Centralized control, however, imposes a scalability problem. In this paper, we investigate the use of multiple independent controllers instead of a single omniscient controller to manage resources. Each controller looks after a portion of the network only, but they together cover the whole network. This therefore solves the scalability problem. We use flow allocation as an example to see how this approach can manage the bandwidth use in a distributed manner. The focus is on how to assign components of a network to the controllers so that (1) each controller only need to look after a small part of the network but (2) there is at least one controller that can answer any request. We outline a way to configure the controllers to fulfill these requirements as a proof that the use of devolved controllers is possible. We also discuss several issues related to such implementation.
High temperature dielectric properties of Apical, Kapton, PEEK, Teflon AF, and Upilex polymers

Apical, Upilex, Kapton, Teflon AF, and PEEK polymers are characterized for AC and DC dielectric breakdown in air and in silicone oil at temperatures up to 250 degrees C. The materials are also tested in terms of their dielectric constant and dissipation factor at high temperatures with an electrical stress of 60 Hz, 200 V/mil present. The effects of thermal aging on the properties of the films are determined after 15 h of exposure at 200 and 250 degrees C. The preliminary data indicate that most of the tested films remain relatively stable when exposed to temperature as high as 250 degrees C. The PEEK film however tends to display some wrinkling and exhibit discoloration when exposed to temperatures of about 200 degrees C and higher. All other films displayed good dielectric and physical properties even up to 250 degrees C. >
Segmented-core single-mode fiber optimized for bending performance

The performance of a matched-clad single-mode fiber design presently under development is described. Fibers of this design, which is based on the segmented-core approach, have been fabricated with a higher delta than simple matched-clad step-index single-mode fibers without a sacrificial increase in either the fiber cutoff or zero dispersion wavelengths. The resulting improvements in both macrobending and microbending performance is detailed. >
Harmonic and refined extraction methods for the singular value problem, with applications in least squares problems

For the accurate approximation of the minimal singular triple (singular value and left and right singular vector), we may use two separate search spaces, one for the left, and one for the right singular vector. In Lanczos bidiagonalization, for example, such search spaces are constructed. In (3), the author proposes a Jacobi-Davidson type method for the singular value problem, where solutions to certain correction equations are used to expand the search spaces. As noted in (3), the standard Galerkin subspace extraction works well for the computation of large singular triples, but may lead to unsatisfactory approximations to small and interior triples. To overcome this problem for the smallest triples, we propose three harmonic and a refined approach. All methods are derived in a number of different ways. Two of these methods can also be applied when we are interested in interior singular triples. Theoretical results as well as numerical experiments indicate that the results of the alternative extraction processes are often better than the standard approach. We show that when Lanczos bidiagonalization is used to approximate the smallest singular triples, the standard, harmonic, and refined extraction methods are all essentially equivalent. This gives more insight in the success of the use of Lanczos bidiagonalization to find the smallest singular triples. Finally, we present a novel method for the least squares problem, the success of which is based on a good extraction process for the smallest singular triples. The truncated SVD is also discussed in this context.
Do Convnets Learn Correspondence

Convolutional neural nets (convnets) trained from massive labeled datasets [1] have substantially improved the state-of-the-art in image classification [2] and object detection [3]. However, visual understanding requires establishing correspondence on a finer level than object category. Given their large pooling regions and training from whole-image labels, it is not clear that convnets derive their success from an accurate correspondence model which could be used for precise localization. In this paper, we study the effectiveness of convnet activation features for tasks requiring correspondence. We present evidence that convnet features localize at a much finer scale than their receptive field sizes, that they can be used to perform intraclass aligment as well as conventional hand-engineered features, and that they outperform conventional features in keypoint prediction on objects from PASCAL VOC 2011 [4].
Does anonymity affect the willingness to accept and willingness to pay gap? A generalization of Plott and Zeiler

Conventional value-elicitation experiments often find subjects provide higher valuations for items they posses than for identical items they may acquire. Plott and Zeiler (Am Econ Rev 95:530–545, 2005) replicate this willingness-to-pay/willingness-to-accept “gap” with conventional experimental procedures, but find no gap after implementing procedures that provide for subject anonymity and familiarity with the second-price mechanism. This paper investigates whether anonymity is necessary for their result. We employ both types of procedures with and without anonymity. Contrary to predictions of one theory—which suggest social pressures may cause differences in subject valuations—we find, regardless of anonymity, conventional procedures generate gaps and Plott and Zeiler’s does not. These findings strongly suggest subject familiarity with elicitation mechanisms, not anonymity, is responsible for the variability in results across value-elicitation experiments. As an application to experimental design methodology, there appears to be little need to impose anonymity when using second-price mechanisms in standard consumer good experiments.
LOCAL ANALYSIS OF DISSIPATIVE DYNAMICAL SYSTEMS

Linear transformation techniques such as singular value decomposition (SVD) have been used widely to gain insight into the qualitative dynamics of data generated by dynamical systems. There have been several reports in the past that had pointed out the susceptibility of linear transformation approaches in the presence of nonlinear correlations. In this tutorial review, the local dispersion along with the surrogate testing is suggested to discriminate nonlinear correlations arising in deterministic and non-deterministic settings.
Algorithm Based fault tolerant state estimation of power systems

Electric power industry deregulation has transformed state estimation from an important application into a critical one. State estimations in power systems involve very tedious computations since large systems can consist of thousands of buses and lines. In this paper, we apply algorithm based fault tolerance techniques to the Gauss-Newton iterative algorithm that solves a weighted least-squares (WLS) state estimator of a power system. These techniques efficiently detect computational errors due to transient and permanent faults in the hardware. We show that the modified state estimation algorithm has low computational over-head and is free from false alarms
WIMP-nucleus scattering in chiral effective theory

We discuss long-distance QCD corrections to the WIMP-nucleon(s) interactions in the framework of chiral effective theory. For scalar-mediated WIMP-quark interactions, we calculate all the next-to-leading-order corrections to the WIMP-nucleus elastic cross-section, including two-nucleon amplitudes and recoil-energy dependent shifts to the single-nucleon scalar form factors. As a consequence, the scalar-mediated WIMP-nucleus cross-section cannot be parameterized in terms of just two quantities, namely the neutron and proton scalar form factors at zero momentum transfer, but additional parameters appear, depending on the short-distance WIMP-quark interaction. Moreover, multiplicative factorization of the cross-section into particle, nuclear and astro-particle parts is violated. In practice, while the new effects are of the natural size expected by chiral power counting, they become very important in those regions of parameter space where the leading order WIMP-nucleus amplitude is suppressed, including the so-called “isospin-violating dark matter” regime. In these regions of parameter space we find order-of-magnitude corrections to the total scattering rates and qualitative changes to the shape of recoil spectra.
The equatorial undercurrent: 100 years of discovery

The Equatorial Undercurrent is a narrow ribbon of eastward flow centered on the equator in the upper thermocline. It is a permanent feature of the general circulation in the Atlantic and Pacific oceans and is present in the Indian Ocean in northern winter and spring during the northeast monsoon. It reaches speeds of 50–100 cm s −1 below the westward flow of the South Equatorial Current, and in the Pacific transports as much mass on average (40×106 m3 s −1 ) as the Florida Current, which feeds the Gulf Stream.
Switch placement to improve system reliability for radial distribution systems with distributed generation

To improve system reliability for radial distribution systems with distributed generation (DG) under fault conditions, switch placement schemes are proposed to form self-supported areas after fault isolation. Customer priority is also considered in this problem. The switch placement problem is formulated as a nondifferentiable, multiobjective optimization problem. Graph-based algorithms, which incorporate direct load control, are developed to locate switches. Their results enable DG to support customers continuously in the event of fault. The proposed algorithms can be applied to unbalanced distribution networks with single or multiple distributed generators. Simulation results on a 394-bus distribution system, including priority customers, and single or multiple distributed generators, were also provided.
Vacuum Instabilities with a Wrong-Sign Higgs-Gluon-Gluon Amplitude

The recently discovered 125 GeV boson appears very similar to a Standard Model (SM) Higgs, but with data favoring an enhanced h → γγ rate. A number of groups have found that fits would allow (or, less so after the latest updates, prefer) that the coupling have the opposite sign. This can be given meaning in the context of an electroweak chiral Lagrangian, but it might also be interpreted to mean that a new colored and charged particle runs in loops and reinforces the W-loop contribution to hFF, while also producing the opposite-sign hGG amplitude to that generated by integrating out the top. Due to a correlation in sign of the new physics amplitudes, when the SM hFF coupling is enhanced the hGG coupling is decreased. Thus, in order to not suppress the rate of h → WW and h → ZZ, which appear to be approximately SM-like, one would need the loop to ‘overshoot’, not only canceling the top contribution but producing an opposite-sign hGG vertex of about the same magnitude as that in the SM. We argue that most such explanations have severe problems with fine-tuning and, more importantly, vacuum stability. In particular, the case of stop loops producing an opposite-sign hGG vertex of the same size as the SM one is ruled out by a combination of vacuum decay bounds and Large Electron–Positron Collider (LEP) constraints. We also show that scenarios with a sign flip from loops of color octet charged scalars or new fermionic states are highly constrained.
Chemical Control of Stem Cell Fate and Developmental Potential

Potential applications of stem cells in medicine range from their inclusion in disease modeling and drug discovery to cell transplantation and regenerative therapies. However, before this promise can be realized several obstacles must be overcome, including the control of stem cell differentiation, allogeneic rejection and limited cell availability. This will require an improved understanding of the mechanisms that govern stem cell potential and the development of robust methods to efficiently control their fate. Recently, a number of small molecules have been identified that can be used both in vitro and in vivo as tools to expand stem cells, direct their differentiation, or reprogram somatic cells to a more naive state. These molecules have provided a wealth of insights into the signaling and epigenetic mechanisms that regulate stem cell biology, and are already beginning to contribute to the development of effective treatments for tissue repair and regeneration.
Comparison of the square-wave and quasi-resonant topologies

The waveforms of a square-wave DC-DC converter and a quasiresonant DC-DC converter are examined in detail and a comparison is made between the switching losses and conduction losses for each topology. Using data from commercially available semiconductor devices, conservative estimates are then given for the switching frequency at which the resonant approach becomes advantageous. The effect of an isolation transformer on this comparison is also addressed. >
Characterization of the transcriptome, nucleotide sequence polymorphism, and natural selection in the desert adapted mouse Peromyscus eremicus.

As a direct result of intense heat and aridity, deserts are thought to be among the most harsh of environments, particularly for their mammalian inhabitants. Given that osmoregulation can be challenging for these animals, with failure resulting in death, strong selection should be observed on genes related to the maintenance of water and solute balance. One such animal, Peromyscus eremicus, is native to the desert regions of the southwest United States and may live its entire life without oral fluid intake. As a first step toward understanding the genetics that underlie this phenotype, we present a characterization of the P. eremicus transcriptome. We assay four tissues (kidney, liver, brain, testes) from a single individual and supplement this with population level renal transcriptome sequencing from 15 additional animals. We identified a set of transcripts undergoing both purifying and balancing selection based on estimates of Tajima’s D. In addition, we used the branch-site test to identify a transcript—Slc2a9, likely related to desert osmoregulation—undergoing enhanced selection in P. eremicus relative to a set of related non-desert rodents.
Violating the Ingleton inequality with finite groups

It is well known that there is a one-to-one correspondence between the entropy vector of a collection of n random variables and a certain group-characterizable vector obtained from a finite group and n of its subgroups [1]. However, if one restricts attention to abelian groups then not all entropy vectors can be obtained. This is an explanation for the fact shown by Dougherty et al [2] that linear network codes cannot achieve capacity in general network coding problems (since linear network codes form an abelian group). All abelian group-characterizable vectors, and by fiat all entropy vectors generated by linear network codes, satisfy a linear inequality called the Ingleton inequality. In this paper, we study the problem of finding non-abelian finite groups that yield characterizable vectors which violate the Ingleton inequality. Using a refined computer search, we find the symmetric group S 5 to be the smallest group that violates the Ingleton inequality. Careful study of the structure of this group, and its subgroups, reveals that it belongs to the Ingleton-violating family PGL(2, p) with primes p ≥ 5, i.e., the projective group of 2×2 nonsingular matrices with entries in F p . This family of groups is therefore a good candidate for constructing network codes more powerful than linear network codes.
A nonlinear small-gain theorem for large-scale time delay systems

This paper extends the nonlinear ISS small-gain theorem to a large-scale time delay system composed of three or more subsystems. En route to proving this small-gain theorem for systems of differential equations with delays, a small-gain theorem for operators is examined. The result developed for operators allows applications to a wide class of systems, including state space systems with delays.
Lightweight Procedural Animation With Believable Physical Interactions

In this paper, we describe Twig, a fast, AI-friendly procedural animation system that supports easy authoring of new behaviors. The system provides a simplified dynamic simulation that is specifically designed to be easy to control. Characters are controlled by applying external forces directly to body parts, rather than by simulating joint torques. This ldquopuppetry-stylerdquo of control provides the simplicity of kinematic control within an otherwise dynamic simulation. Although less realistic than motion capture or full biomechanical simulation, Twig produces compelling, responsive character behavior. Moreover, it is fast, stable, supports believable physical interactions between characters such as hugging, punching, and dragging, and makes it easy to author new behaviors.
A touch sensitive X-Y position encoder for computer input

Any input device used in conjunction with a computer controlled display for interactive information exchange between man and computer must function as a position encoder. Input devices for handling two dimensional positional information can be grouped into two general types, one type encoding absolute positions and the other encoding changes in position.
An independent refinement and integration procedure in multiregion finite element analysis

An independent refinement and integration procedure is developed to couple together independently modelled (global and local) regions in a single analysis. The finite element models can have different levels of refinement and the nodes along the interface between them need not coincide with one another. A spline interpolation function that satisfies the linear isotropic plate-bending differential equation is used to relate the local model interface nodal displacements to the global model interface displacements. The proposed independent refinement and integration procedure is validated by applying it to problems involving in-plane and out-of-plane deformations.