cssi/SciSciGPT-SciSciNet huggingface dataset:
Information markets over trust networks

Information markets are inefficient. Information products have large upfront development costs, yet their duplication costs are negligibly small; and they are experience goods with high costs of marketing and promotion. As a result, either winner-take-all markets are created through large and expensive promotional campaigns, or artificial monopoly power is conferred by the government through copyright protection, or both, to prevent the collapse of these markets from intense price competition and piracy. Such inefficiency creates opportunities to design more efficient markets by utilizing new technologies. Trust networks provide such an opportunity where the network infrastructure acts not only as a distribution system for information products, but also as an advertising and promotion medium, a payment and pricing mechanism, a guarantee and insurance service, and a copyright enforcement and dispute resolution tool. Such a network-centric market place is proposed to remedy many of the shortcomings of mass markets by relying on peer-to-peer distribution, peer-to-peer payments, and peer-to-peer enforcement of trust and integrity. Analytical models are presented to show that such a market place for information goods can scale up to satisfy large markets without expensive promotions and advertising campaigns, create customized products with dynamic pricing, reduce entry costs by eliminating the distinction between buyers and sellers, and eliminate the need for copyright protection.
A quiet-flow Ludwieg tube for experimental study of high speed boundary layer transition

A new low Reynolds number quiet-flow Ludwieg tube facility, now under construction, is briefly described, and its advantages outlined. The facility is characterized by good optical access and may be particularly useful for the development of optical instrumentation for the generation and measurement of instability waves. Initial research plans also include work on hot-wire instrumentation, wave generation techniques, roughness and receptivity effects, and suction distribution effects.
Learning in knowledge base management systems

This chapter argues that techniques from the field at Machine Learning may play a significant role in future Knowledge-Base Management Systems. We describe a specific knowledge-based consultant system which automatically augments its knowledge base by observing and generalizing from the problem solving steps contributed by its users.
The new Zintl phases Eu21Cd4Sb18 and Eu21Mn4Sb18

Abstract Crystals of two new Zintl compounds, Eu21Mn4Sb18 and Eu21Cd4Sb18 have been synthesized using the molten metal flux method, and their structures have been established by single-crystal X-ray diffraction. Both compounds are isotypic and crystallize in the monoclinic space group C2/m (No. 12, Z=4). The structures are based on edge- and corner-shared MnSb4 or CdSb4 tetrahedra, which make octameric [Mn8Sb22] or [Cd8Sb22] polyanions. Homoatomic Sb–Sb bonds are present in both structures. The Eu atoms take the role of Eu2+cations with seven unpaired 4f electrons, as suggested by the temperature-dependent magnetization measurements. The magnetic susceptibilities of Eu21Mn4Sb18 and Eu21Cd4Sb18 indicate that both phases order anti-ferromagnetically with Neel temperatures of ca. 7 K and ca. 10 K, respectively. The unpaired 3d electrons of the Mn atoms in Eu21Mn4Sb18 do contribute to the magnetic response, however, the bulk magnetization measurements do not provide evidence for long-range ordering of the Mn spins down to 5 K. Electrical resistivity measurements suggest that both compounds are narrow band gap semiconductors.
Studies of Rubberlike Polymers by Nuclear Magnetism

The actual width of the proton resonance line in uncured natural rubber has been determined at room temperature to be 0.06 gauss. Curing of polymers increases the line width at a given temperature. The small increase in natural rubber is possibly compatible with a physical bonding rather than the usually assumed cross linking. For a butadiene‐styrene copolymer the increase in line width due to cure is somewhat larger. Carbon black loading increases the line width to a lesser degree than cure. This is compatible with the concept of physical bonding between the blacks and the polymer chain molecules. Variations in line width caused by changes in chemical composition and copolymerization were also investigated. Polypropylene and polypropylene oxide of roughly the same average molecular weight are compared. The polypropylene oxide exhibits a greater degree of ``rotation'' about its C–O bonds than polypropylene does about its C–C bonds. Two butadiene‐acrylonitrile copolymers also have been studied as a functio...
Smoke in the City: How Often and Where Does Smoke Impact Summertime Ozone in the United States?

We investigate the influence of smoke on ozone (O3) abundances over the contiguous United States. Using colocated observations of particulate matter and the National Weather Service Hazard Mapping System smoke data, we identify summertime days between 2005 and 2014 that Environmental Protection Agency Air Quality System O3 monitors are influenced by smoke. We compare O3 mixing ratio distributions for smoke-free and smoke-impacted days for each monitor, while controlling for temperature. This analysis shows that (i) the mean O3 abundance measured on smoke-impacted days is higher than on smoke-free days, and (ii) the magnitude of the effect varies by location with a range of 3 to 36 ppbv. For each site, we present the percentage of days when the 8-h average O3 mixing ratio (MDA8) exceeds 75 ppbv and smoke is present. Smoke-impacted O3 mixing ratios are most elevated in locations with the highest emissions of nitrogen oxides. The Northeast corridor, Dallas, Houston, Atlanta, Birmingham, and Kansas City stand...
A taxonomy of privacy-protecting tools to browse the world wide web

There is a growing public concern regarding big data and intelligence surveillance on unsuspecting Internet users, and an increase in public conversation around what does privacy really mean in the digital realm. Although technologies have been developed to help generate public protect their privacy, average users found the tools complex and difficult to decipher. This research aims to weed through some of these complexities by reviewing 6 publicly recognized technologies promoted to help users protect their privacy while browsing the web. The scope will be broad in order to touch on the important aspects each technology including promises, privacy realities, technical construct, ease of use and drawbacks average users should be aware of before using.
Capturing Dynamic Textured Surfaces of Moving Targets

We present an end-to-end system for reconstructing complete watertight and textured models of moving subjects such as clothed humans and animals, using only three or four handheld sensors. The heart of our framework is a new pairwise registration algorithm that minimizes, using a particle swarm strategy, an alignment error metric based on mutual visibility and occlusion. We show that this algorithm reliably registers partial scans with as little as 15 % overlap without requiring any initial correspondences, and outperforms alternative global registration algorithms. This registration algorithm allows us to reconstruct moving subjects from free-viewpoint video produced by consumer-grade sensors, without extensive sensor calibration, constrained capture volume, expensive arrays of cameras, or templates of the subject geometry.
Jobs in the city : explaining urban spatial structure in Kampala

This paper examines the spatial organization of jobs in Kampala, the capital city of Uganda, and applies the Lucas and Rossi-Hansberg (2002) model to explain the observed patterns in terms of the agglomeration forces and the commuting costs of workers. The paper suggests that: (i) Economic activities are concentrated in the downtown -- beyond which employment is spatially dispersed. (ii) Geographically weighted regressions identify five potential subcenters in 2011; however, none of these contribute significantly to employment. When explaining the variation in employment density across localities in Kampala, the research highlights that (i) density falls by 23.5 percent per kilometer increase in distance from the nearest potential subcenter; (ii) an increase in local production externalities of 10 percent increases density by 3.7 percent; and (iii) production externalities in Kampala's potential subcenters are extremely weak to have any significant impact even on nearby tracts.
A weighted edge-count two-sample test for multivariate and object data

ABSTRACTTwo-sample tests for multivariate data and non-Euclidean data are widely used in many fields. Parametric tests are mostly restrained to certain types of data that meets the assumptions of the parametric models. In this article, we study a nonparametric testing procedure that uses graphs representing the similarity among observations. It can be applied to any data types as long as an informative similarity measure on the sample space can be defined. The classic test based on a similarity graph has a problem when the two sample sizes are different. We solve the problem by applying appropriate weights to different components of the classic test statistic. The new test exhibits substantial power gains in simulation studies. Its asymptotic permutation null distribution is derived and shown to work well under finite samples, facilitating its application to large datasets. The new test is illustrated through an analysis on a real dataset of network data.
The Effectiveness of Social Science Research in Addressing Societal Problems: Broadening Participation in Computing

One important rationale for federal funding of social science research is its role in addressing pressing social problems. In this article we examine the impact of the National Science Foundation’s Information Technology Workforce Program (ITWF) on broadening participation in computing and IT careers. Established in 2000 in response to the declining participation of women and minorities in computer science education and IT careers, the ITWF Program awarded almost US$30 million in research funding through its final solicitation in 2004. We document the quantitative and qualitative effects of this research funding, both to illustrate the complex ways in which R&D funding can advance scientific understanding and to identify the challenges that such problem-driven social science research may encounter. The problem of diversity in the IT workforce has not been solved. Nonetheless, the ITWF program had important effects on the understanding of this problem and efforts to address it.
Advancements in afterbody radiative heating simulations for earth entry

Four advancements to the simulation of backshell radiative heating for Earth entry are presented. The first of these is the development of a flow field model that treats electronic levels of the dominant backshell radiator, N, as individual species. This is shown to allow improvements in the modeling of electron-ion recombination and two-temperature modeling, which are shown to increase backshell radiative heating by 10 to 40%. By computing the electronic state populations of N within the flow field solver, instead of through the quasi-steady state approximation in the radiation code, the coupling of radiative transition rates to the species continuity equations for the levels of N, including the impact of non-local absorption, becomes feasible. Implementation of this additional level of coupling between the flow field and radiation codes represents the second advancement presented in this work, which is shown to increase the backshell radiation by another 10 to 50%. The impact of radiative transition rates due to non-local absorption indicates the importance of accurate radiation transport in the relatively complex flow geometry of the backshell. This motivates the third advancement, which is the development of a ray-tracing radiation transport approach to compute the radiative transition rates and divergence of the radiative flux at every point for coupling to the flow field, therefore allowing the accuracy of the commonly applied tangent-slab approximation to be assessed for radiative source terms. For the sphere considered at lunar-return conditions, the tangent-slab approximation is shown to provide a sufficient level of accuracy for the radiative source terms, even for backshell cases. This is in contrast to the agreement between the two approaches for computing the radiative flux to the surface, which differ by up to 40%. The final advancement presented is the development of a nonequilibrium model for NO radiation, which provides significant backshell radiation at velocities below 10 km/s. The developed model reduces the nonequilibrium NO radiation by 50% relative to the previous model.
An overview of the scientist's responsibilities: comments by an ethicist.

I want to discuss a problem which has been running through lots of people's papers and comments at this meeting; namely, the problem of what we should think about the human fetus from a moral point of view. Morally speaking, what are fetuses, and what may or may not be done to them? As a preface to my remarks, I will say something about the question of whether each of us has the right to follow his own conscience in this area-to make his own moral decisions and to act on his own moral views without interference by others. Yesterday several people argued that we should not try to impose our moral views on one another. Each scientist, it was said, should make his own moral judgments and conduct his own research as seems best to him. This may seem an attractive idea, which cuts through a lot of difficulties: I have no right to tell you what you can or cannot do, and you have no right to tell me what I can or cannot do. While we might exchange ideas, still this is only an exchange of ideas and ultimately each individual must make up his own mind about these matters. As a general proposition about ethics, no one really accepts this. For example, we all agree that it is immoral to murder someone or to rape someone, but we haven't the slightest hesitation in imposing this view on others, or in invoking the power of the law to prohibit behavior of this sort. If a murderer or a rapist were to say, "My moral ideas are different from yours; you follow your conscience and let me follow mine," we wouldn't accept this for a moment. There are, of course, other areas in which we think the individual does have a right to follow his own lights without interference from others. For example, a person's private sexual conduct is his own business, and others have no right to interfere.
Selective Radical-Radical Cross-Couplings: Design of a Formal β-Mannich Reaction.

A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical–radical coupling. This novel pathway to γ-aminoketones is predicated upon the use of DABCO as both a base and an electron transfer agent. This protocol also formally allows for the direct synthesis of β-Mannich products via a chemoselective three-component coupling of aryl aldehydes, amines, and ketones.
Differential and pass-transistor CMOS logic for high performance systems

Abstract This paper presents a review of differential and pass-transistor logic used in today's high performance systems. Various circuit and logic design styles used in contemporary high performance processors have been reviewed. The new logic is advantageous over standard CMOS in terms of performance and. very often in terms of area, speed and power as well. Evolution of various high performance latches has been presented.
Epigenetic contribution of the myosin light chain kinase gene to the risk for acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a devastating clinical syndrome with a considerable case fatality rate (∼30%–40%). Health disparities exist with African descent (AD) subjects exhibiting greater mortality than European descent (ED) individuals. Myosin light chain kinase is encoded by MYLK, whose genetic variants are implicated in ARDS pathogenesis and may influence ARDS mortality. As baseline population-specific epigenetic changes, that is, cytosine modifications, have been observed between AD and ED individuals, epigenetic variations in MYLK may provide insights into ARDS disparities. We compared methylation levels of MYLK cytosine-guanine dinucleotides (CpGs) between ARDS patients and intensive care unit (ICU) controls overall and by ethnicity in a nested case–control study of 39 ARDS cases and 75 non-ARDS ICU controls. Two MYLK CpG sites (cg03892735 and cg23344121) were differentially modified between ARDS subjects and controls (P
IEEE P1149.5 standard module test and maintenance bus

The IEEE P1149.5 standard module test and maintenance bus (MTM-Bus) standardizes a serial, backplane test & maintenance bus that can be used to integrate modules into testable and maintainable subsystems. This paper discusses the protocol, some implementation details and the status of the standard and related standards activities. >
Apical Lung Herniation Associated with Continuous Positive Airway Pressure in a 4-Year-Old Girl

We report a case of apical lung herniation through the superior thoracic aperture of an obese child using nocturnal CPAP. Lung herniation has been described in association with congenital thoracic ...
A modular data acquisition system using the 10 GSa/s PSEC4 waveform recording chip

We describe a modular multi-channel data acquisition system based on the 5–15 Gigasample-per-second waveform-recording PSEC4 chip. The system architecture incorporates two levels of hardware with FPGA-embedded system control and inline data processing. The front-end unit is a 30-channel circuit board that holds five PSEC4 ASICs, a clock jitter cleaner, and a control FPGA. The analog bandwidth of the front-end signal path is 1.5 GHz. Each channel has an on-chip threshold-level discriminator that is monitored in the FPGA, from which a flexible on-board trigger decision can be formed. To instrument larger channel counts, a ‘back-end’ 6U VME32 control card has been designed. Called the ‘Central Card’, it incorporates an Altera Arria-V FPGA that manages up to 8 front-end cards using one or two CAT5 network cables per board, which transmits the clock and communicates data packets over a custom serial protocol. Data can be read from the Central Card via USB, Ethernet, or dual SFP links, in addition to the VME interface. The Central Card can be configured as either Master or Slave, allowing one Master to receive data from up to 8 Slaves, with each Slave managing 8 30-channel front-end cards, allowing a single VME crate to control up to 1920 channels of the PSEC4 chip.
Orthogonal wavelet transforms and filter banks

Summary form only given. A new class of orthogonal basis functions that can be relevant to signal processing has recently been introduced. These bases are constructed from a single smooth bandpass function psi (t), the wavelet, by considering its translates and dilates on a dyadic grid 2/sup n/, 2/sup n/m of points, psi /sub n,m/(t)=2/sup -n/2/ psi (2/sup -n/t-m). It is required that psi (t) be well localized in both the time and frequency domain, without violating the uncertainty principle. Any one-dimensional signal can be represented by the bidimensional set of its expansion coefficients. Multidimensional signals can also be expanded in terms of wavelet bases. An algorithm for computing the expansion coefficients of a signal in terms of wavelet bases has been found, the structure of which is that of a pruned-tree quadrature mirror multirate filter bank. The construction of wavelet bases and their relation to filter banks, together with several design techniques for wavelet generating quadrature mirror filters and examples, are reviewed. >
Disaster Loss and Social Media: Can Online Information Increase Flood Resilience?

When confronted with natural disasters, individuals around the world increasingly use online resources to become informed of forecasted conditions and advisable actions. This study tests the effectiveness of online information and social media in enabling households to reduce disaster losses. The 2011 Bangkok flood is utilized as a case study since it was one of the first major disasters to affect a substantial population connected to social media. The role of online information is investigated with a mixed methods approach. Both quantitative (propensity score matching) and qualitative (in-depth interviews) techniques are employed. The study relies on two data sources – survey responses from 469 Bangkok households and in-depth interviews with twenty-three internet users who are a subset of the survey participants. Propensity score matching indicates that social media enabled households to reduce flood losses by an average of 37% (USD 3,708 per household), using a nearest neighbor estimator. This reduction is substantial when considering that household flood losses for the matched sample averaged USD 8,278. Social media offered information not available from other sources, such as localized and nearly real-time updates of flood location and depth. With this knowledge, households could move belongings to higher ground before floodwaters arrived. These findings suggest that utilizing social media users as sensors could better inform populations during disasters. Overall, the study reveals that online information can enable effective disaster preparedness and reduce losses. This article is protected by copyright. All rights reserved.
The Cross Section of Expected Real Estate Returns: Insights from Investment-Based Asset Pricing

Motivated by investment-based asset pricing, we show that two firm fundamentals, investment and profitability, have substantial predictive power for REIT returns. The return predictability of investment and profitability is not subsumed by conventional models and can be useful for understanding the cross section of expected REIT returns. To illustrate, we construct an investment-based factor model for REITs that consists of a market factor, an investment factor, and a profitability factor. The investment-based model outperforms conventional models in capturing well-known cross-sectional patterns in REIT returns. Our findings suggest that incorporating investment-based asset pricing can be a promising direction for future real estate finance research.
Bootstrapping mixed correlators in the five dimensional critical O ( N ) models

We use the conformal bootstrap approach to explore 5D CFTs with O(N) global symmetry, which contain N scalars ϕ i transforming as O(N) vector. Specifically, we study multiple four-point correlators of the leading O(N) vector ϕ i and the O(N) singlet σ. The crossing symmetry of the four-point functions and the unitarity condition provide nontrivial constraints on the scaling dimensions (Δ ϕ , Δ σ ) of ϕ i and σ. With reasonable assumptions on the gaps between scaling dimensions of ϕ i (σ) and the next O(N) vector ϕ ′ (singlet σ ′ ) scalar, we are able to isolate the scaling dimensions (Δ ϕ , Δ σ ) in small islands. In particular, for large N = 500, the isolated region is highly consistent with the result obtained from large N expansion. We also study the interacting O(N) CFTs for 1≤N ≤100. Isolated regions on (Δ ϕ , Δ σ ) plane are obtained using conformal bootstrap program with lower order of derivatives Λ; however, they disappear after increasing Λ. For N = 100, no solution can be found with Λ = 25 under the assumptions on the scaling dimensions of next O(N) vector $$ {\varDelta}_{\phi_i^{\prime }}\ge\ 5.0 $$ (singlet Δ σ ′ ≥ 3.3). These islands are expected to be corresponding to interacting but nonunitary O(N) CFTs. Our results suggest a lower bound on the critical value N c > 100, below which the interacting O(N) CFTs turn into nonunitary.
CERAMIC ON CERAMIC HIP ARTHROPLASTY: AN ENDURING SOLUTION

While crosslinked polyethylene has reduced the rate of wear and osteolysis in THA, osteolysis still occurs and taper-corrosion induced wear has become recognised as an increasing problem especially when larger diameter metal bearings are used. Long-term follow up studies of newer polyethylene bearings continue to lag those of ceramic-on-ceramic bearings by several years. Ceramic-on-ceramic (CoC) bearing surfaces have consistently demonstrated reliable clinical results with when coupled with appropriated designed femoral stems and acetabular shells and have been shown to exhibit virtually no risk of adverse biologic reaction. Further, CoC bearings have not been associated with corrosion-induced adverse tissue reactions that occur with metal taper junctions. Revisions for squeaking have been associated with specific designs and materials, including the use of a titanium elevated metal rim on the acetabular side, and more flexible femoral components made of a beta-titanium alloy (TMZF) which had thin necks and relatively small tapers. Multiple clinical studies document excellent long-term survival of CoC bearing couples in young patients with revision for any reason as the primary endpoint. Our own experience with 341 hips in patients under 50 with 2–15 years and average 9.1-year follow up demonstrates a 95% overall survivorship (revision for any reason) at 13 years. CoC bearings continue to show excellent durability in young, high demand patients with an absence of osteolysis in any case. CoC bearings continue to represent an excellent alternative to bearing couples containing polyethylene.
Formation of the Sputnik Planum basin and the thickness of Pluto's subsurface ocean

We simulate the formation of the large elliptical impact basin associated with Pluto's Sputnik Planum (SP; informal name). The location of SP suggests that it represents a large positive mass anomaly. To find the conditions necessary for SP to have a positive mass anomaly, we consider impacts into targets with a range of thermal states and ocean thicknesses. Assuming the basin evolves to its current day configuration, we calculate the mass and gravity anomalies associated with SP. We find that SP can only achieve a large positive mass anomaly if Pluto has a more than 100 km thick salty ocean. This conclusion may help us better understand the composition and thermal evolution of Pluto. Furthermore, our work supports the hypothesis that SP basin has an impact origin.
Uncontrolled Generator Operation of PM Synchronous Machine Drive With Current-Source Inverter Using Normally on Switches

This paper investigates the uncontrolled generator (UCG) operating characteristics of permanent magnet (PM) synchronous machine drives using current-source inverters (CSIs) with normally on switches. This special mode occurs when a PM machine is spinning at a high speed and gating signals are simultaneously removed from all of the inverter switches. This investigation shows that the UCG operating characteristics are quite different when the PM machine is combined with a CSI that uses normally on switches, compared to the use of a conventional voltage-source inverter (VSI). The presence of the stiff dc-link current prevents high transient currents from being developed in the machine phases that can expose the machine's rotor magnets to significant demagnetization risks. As a result, the UCG characteristics of the CSI-based PM machine drive with normally on switches are more benign than those of comparable VSI-based drives, representing an advantage of the CSI drive configuration during fault-mode operation. Experimental test results for UCG-mode operation with a 2.6-kW current-source PM drive are included that exhibit good agreement with the analytical predictions.
Detection of exocrine dysfunction by MRI in patients with early chronic pancreatitis

To determine if T1-weighted MR signal of the pancreas can be used to detect early CP. A retrospective analysis was performed on 51 suspected CP patients, who had both secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) and an intraductal secretin stimulation test (IDST). There were 29 patients in normal and 22 patients in the low bicarbonate group. Bicarbonate level, total pancreatic juice volume, and excretory flow rate were recorded during IDST. Signal intensity ratio of pancreas (SIR), fat signal fraction, pancreatograms findings, and grade of duodenal filling were recorded on S-MRCP by two blinded radiologists. There was a significant difference in the signal intensity ratio of the pancreas to spleen (SIRp/s) between the normal and low bicarbonate groups (p < 0.0001). A significant positive correlation was found between pancreatic fluid bicarbonate level and SIRp/s (p < 0.0001). SIRp/s of 1.2 yielded sensitivity of 77% and specificity of 83% for detection of pancreatic exocrine dysfunction (AUC: 0.89). T1-weighted MR signal of the pancreas has a high sensitivity and specificity for the detection of parenchymal abnormalities related to exocrine dysfunction and can therefore be helpful in evaluation of suspected early CP.
INTERMARRIAGE AND THE LABOR MARKET OUTCOMES OF ASIAN WOMEN

The impact of intermarriage with natives, on labor market outcomes of immigrants, is not homogeneous across ethnic groups. Wages of Asian women are compared with non-Asians. Both ordinary least squares and instrumental variables estimates of the effects of intermarriage on the wages of Asian women are negative and significant. Non-Asian women earn a wage premium that becomes insignificant when controls for selection into marriage are introduced. One possible explanation for the intermarriage penalty for Asians is an income effect of having a high-earning native husband. Intermarriage penalties rise with husband's education. Assimilation patterns of intermarried Asians indicate that they have lower initial wages, market hours, and employment, but exhibit faster rates of growth over their years of stay. The results are robust across Asian subgroups and husband's ethnicity. (JEL J16, J12, J31, J61)
Carrier Recovery Techniques using Synchronous Oscillators

A Synchronous Oscillator (SO) is a synchronization and tracking network which synchronizes, tracks, filters, amplifies and divides (if necessary) in a single process. It has very good noise rejection properties while maintaining wide tracking range. It acquires very fast in burst mode operation. Various carrier recovery techniques are introduced which use SOs in feedforward and feedback configurations. Also, a preamble carrier recovery technique is introduced. It uses a Coherent Phase-Locked Synchronous Oscillator (CPSO). A CPSO is the only existing network which has absolute coherency (zero phase error) throughout its tracking range with first degree loop and its noise bandwidth is independent of its tracking range.
DPPred: An Effective Prediction Framework with Concise Discriminative Patterns

In the literature, two series of models have been proposed to address prediction problems including classification and regression. Simple models, such as generalized linear models, have ordinary performance but strong interpretability on a set of simple features. The other series, including tree-based models, organize numerical, categorical, and high dimensional features into a comprehensive structure with rich interpretable information in the data. In this paper, we propose a novel Discriminative Pattern-based Prediction framework ( $\sf {DPPred}$ ) to accomplish the prediction tasks by taking their advantages of both effectiveness and interpretability. Specifically, $\sf {DPPred}$ adopts the concise discriminative patterns that are on the prefix paths from the root to leaf nodes in the tree-based models. $\sf {DPPred}$ selects a limited number of the useful discriminative patterns by searching for the most effective pattern combination to fit generalized linear models. Extensive experiments show that in many scenarios, $\sf {DPPred}$ provides competitive accuracy with the state-of-the-art as well as the valuable interpretability for developers and experts. In particular, taking a clinical application dataset as a case study, our $\sf {DPPred}$ outperforms the baselines by using only 40 concise discriminative patterns out of a potentially exponentially large set of patterns.
Thermoelectric studies of nanoporous thin films with adjusted pore-edge charges

In recent years, nanoporous thin films have been widely studied for thermoelectric applications. High thermoelectric performance is reported for nanoporous Si films, which is attributed to the dramatically reduced lattice thermal conductivity and bulk-like electrical properties. Porous materials can also be used in gas sensing applications by engineering the surface-trapped charges on pore edges. In this work, an analytical model is developed to explore the relationship between the thermoelectric properties and pore-edge charges in a periodic two-dimensional nanoporous material. The presented model can be widely used to analyze the measured electrical properties of general nanoporous thin films and two-dimensional materials.
A holographic model for pseudogap in BCS–BEC crossover (I): Pairing fluctuations, double-trace deformation and dynamics of bulk bosonic fluid

Abstract We build a holographic model for the pairing fluctuation pseudogap phase in fermionic high temperature superconductivity/superfluidity based on the BCS–BEC crossover scenario. The pseudogap originates from incoherent Cooper pairing and has been observed in recent cold atom experiments. The strength of Cooper pairing and hence the BCS–BEC crossover is controlled by an effective 4-Fermi interaction and we argue that the double-trace deformation for charged scalar operator is a close analog in large N field theories. We employ the double-trace deformed Abelian Higgs model of holographic superconductors and propose that the incoherent fluctuations of the charged scalar in the bulk is the holographic dual of the fluctuating Cooper pairs. Using a Madelung transformation and the velocity-potential formalism, we develop a quantum fluid dynamics as an effective theory for these bulk fluctuations. The new fluid dynamics takes care of the boundary conditions required by AdS/CFT and encodes the vacuum polarization effect in curved spacetime. The pseudogap in conductivity can be related to the plasma oscillation of this bulk fluid.
GRAM: Graph-based Attention Model for Healthcare Representation Learning

Deep learning methods exhibit promising performance for predictive modeling in healthcare, but two important challenges remain: - Data insufficiency: Often in healthcare predictive modeling, the sample size is insufficient for deep learning methods to achieve satisfactory results. Interpretation: The representations learned by deep learning methods should align with medical knowledge. To address these challenges, we propose GRaph-based Attention Model (GRAM) that supplements electronic health records (EHR) with hierarchical information inherent to medical ontologies. Based on the data volume and the ontology structure, GRAM represents a medical concept as a combination of its ancestors in the ontology via an attention mechanism. We compared predictive performance (i.e. accuracy, data needs, interpretability) of GRAM to various methods including the recurrent neural network (RNN) in two sequential diagnoses prediction tasks and one heart failure prediction task. Compared to the basic RNN, GRAM achieved 10% higher accuracy for predicting diseases rarely observed in the training data and 3% improved area under the ROC curve for predicting heart failure using an order of magnitude less training data. Additionally, unlike other methods, the medical concept representations learned by GRAM are well aligned with the medical ontology. Finally, GRAM exhibits intuitive attention behaviors by adaptively generalizing to higher level concepts when facing data insufficiency at the lower level concepts.
Joint hierarchical models for sparsely sampled high-dimensional LiDAR and forest variables

Abstract Recent advancements in remote sensing technology, specifically Light Detection and Ranging (LiDAR) sensors, provide the data needed to quantify forest characteristics at a fine spatial resolution over large geographic domains. From an inferential standpoint, there is interest in prediction and interpolation of the often sparsely sampled and spatially misaligned LiDAR signals and forest variables. We propose a fully process-based Bayesian hierarchical model for above ground biomass (AGB) and LiDAR signals. The process-based framework offers richness in inferential capabilities, e.g., inference on the entire underlying processes instead of estimates only at pre-specified points. Key challenges we obviate include misalignment between the AGB observations and LiDAR signals and the high-dimensionality in the model emerging from LiDAR signals in conjunction with the large number of spatial locations. We offer simulation experiments to evaluate our proposed models and also apply them to a challenging dataset comprising LiDAR and spatially coinciding forest inventory variables collected on the Penobscot Experimental Forest (PEF), Maine. Our key substantive contributions include AGB data products with associated measures of uncertainty for the PEF and, more broadly, a methodology that should find use in a variety of current and upcoming forest variable mapping efforts using sparsely sampled remotely sensed high-dimensional data.
Corrosion of carbon steel and 18% Cr-8% Ni stainless steels in 23% by weight fluorosilicic acid and 10-30-0 suspension fertilizer with fluorosilicic acid added

Research studies conducted by the Tennessee Valley Authority (TVA) have shown that addition of fluorosilicic acid can improve the physical properties of suspension fertilizers made from monoammonium phosphate (MAP) containing metallic impurities. The experimental data showed that addition of as little as 0.6% fluorine as fluorosilicic acid to a 10-30-0 grade suspension improved its viscosity, pourability, and high-temperature storage and increased the water solubility of the nitrogen and P2O5. Because fluorosilicic acid is very corrosive in nature, a series of electrochemical and immersion corrosion tests was conducted to study the effect of fluorosilicic acid on the corrosiveness of 10-30-0 suspension containing fluorosilicic acid. The corrosion tests included exposure of mild steel and several popular austenitic stainless steels under static conditions at both ambient temperature and 130°F. Tests were also made with the corrosion test specimens exposed in fluorosilicic acid (23% by wt). This paper includes results of these corrosion tests.
Housing Supply Elasticity and Rent Extraction by State and Local Governments

Abstract Governments may extract rent from private citizens by inflating taxes and spending on projects benefiting special interests. Using a spatial equilibrium model, I show that less elastic housing supplies increase governments’ abilities to extract rents. Inelastic housing supply, driven by exogenous variation in local topography, raises local governments’ tax revenues and causes citizens to combat rent seeking by enacting laws limiting the power of elected officials. I find that public sector workers, one of the largest government special interests, capture a share of these rents through increased compensation when collective bargaining is legal or through corruption when collective bargaining is outlawed. (JEL H71, H72, J45, J52, R31, R51)
Tunable metasurfaces via subwavelength phase shifters with uniform amplitude

Metasurfaces with tunable spatial phase functions could benefit numerous applications. Currently, most approaches to tuning rely on mechanical stretching which cannot control phase locally, or by modulating the refractive index to exploit rapid phase changes with the drawback of also modulating amplitude. Here, we propose a method to realize phase modulation at subwavelength length scales while maintaining unity amplitude. Our device is inspired by an asymmetric Fabry-Perot resonator, with pixels comprising a scattering nanopost on top of a distributed Bragg reflector, capable of providing a nearly 2π nonlinear phase shift with less than 2% refractive index modulation. Using the designed pixels, we simulate a tunable metasurface composed of an array of moderately coupled nanopost resonators, realizing axicons, vortex beam generators, and aspherical lenses with both variable focal length and in-plane scanning capability, achieving nearly diffraction-limited performance. The experimental feasibility of the proposed method is also discussed.
Modulation calorimetry in diamond anvil cells. II. Joule-heating design and prototypes

Part I shows that quantitative measurements of heat capacity are theoretically possible inside diamond anvil cells via high-frequency Joule heating (100 kHz–10 MHz), opening up the possibility of new methods to detect and characterize transformations at high-pressure such as the glass transitions, melting, magnetic orderings, and the onset of superconductivity. Here, we test the possibility outlined in Part I, using prototypes and detailed numerical models. First, a coupled electrical-thermal numerical model shows that specific heat of metals inside diamond cells can be measured directly using ∼1 MHz frequency, with <10% accuracy. Second, we test physical models of high-pressure experiments, i.e., diamond-cell mock-ups. Metal foils of 2–6 μm-thickness are clamped between glass insulation inside diamond anvil cells. Fitting data from 10 Hz to ∼30 kHz, we infer the specific heat capacities of Fe, Pt, and Ni with ±20%–30% accuracy. The electrical test equipment generates −80 dBc spurious harmonics, which overwhelm the thermally induced harmonics at higher frequencies, disallowing the high precision expected from numerical models. An alternative Joule-heating calorimetry experiment, on the other hand, does allow absolute measurements with <10% accuracy, despite the −80 dBc spurious harmonics: the measurement of thermal effusivity, ρck (ρ, c, and k being density, specific heat, and thermal conductivity), of the insulation surrounding a thin-film heater. Using a ∼50 nm-thick Pt heater surrounded by glass and 10 Hz–300 kHz frequency, we measure thermal effusivity with ±6% accuracy inside the sample chamber of a diamond anvil cell.
Wavepackets in inhomogeneous periodic media: Effective particle-field dynamics and Berry curvature

We consider a model of an electron in a crystal moving under the influence of an external electric field: Schrodinger’s equation with a potential which is the sum of a periodic function and a general smooth function. We identify two dimensionless parameters: (re-scaled) Planck’s constant and the ratio of the lattice spacing to the scale of variation of the external potential. We consider the special case where both parameters are equal and denote this parameter ϵ. In the limit ϵ↓0, we prove the existence of solutions known as semiclassical wavepackets which are asymptotic up to “Ehrenfest time” t∼ln1/ϵ. To leading order, the center of mass and average quasi-momentum of these solutions evolve along trajectories generated by the classical Hamiltonian given by the sum of the Bloch band energy and the external potential. We then derive all corrections to the evolution of these observables proportional to ϵ. The corrections depend on the gauge-invariant Berry curvature of the Bloch band and a coupling to the e...
Tandem Cyclic Alignment

We present a solution for the following problem. Given two sequences X = x1x2...xn and Y = y1y2...ym, n≤m, find the best scoring alignment of X' = Xk[i] vs. Y over all possible pairs (k,i), for k = 1, 2 ....and 1≤i≤n, where X[i] is the cyclic permutation of X starting at xi, Xk[i] is the concatenation of k complete copies of X[i] (k tandem copies), and the alignment must include all of Y and all of X'. Our algorithm allows any alignment scoring scheme with additive gap costs and uses O(nm log n) time and O(nm) space. We use it to identify related tandem repeats in the C. elegans genome as part of the development of a multi-genome database of tandem repeats.
A Model of Secular Stagnation: Theory and Quantitative Evaluation

This paper formalizes and quantifies the secular stagnation hypothesis, defined as a persistently low or negative natural rate of interest leading to a chronically binding zero lower bound (ZLB). Output-inflation dynamics and policy prescriptions are fundamentally different from those in the standard New Keynesian framework. Using a 56-period quantitative life cycle model, a standard calibration to US data delivers a natural rate ranging from –1:5% to –2%, implying an elevated risk of ZLB episodes for the foreseeable future. We decompose the contribution of demographic and technological factors to the decline in interest rates since 1970 and quantify changes required to restore higher rates.
Chapter 4 – Pharmacological Assay Formats: Binding

The theory of binding experiments begins this chapter followed by discussions of multi-state binding and the optimal experimental conditions required for binding strategies. These ideas are considered in relation to the two main types of binding experiments done in practice, saturation binding and displacement binding.
Optimization of Anastomotic Geometry for Vascular Access Fistula

Arteriovenous fistula (AVF) is one type of vascular access which is a surgically created vein used to remove and return blood during hemodialysis [1]. It is a long-term treatment for kidney failure. Although clinical treatment and technology have both achieved great improvements in recent years, the vascular access for hemodialysis still has significant early failure rates after the insertion of AVF in patients [2]. Studies have shown that stenosis in the vascular access circuit is the single major cause for access morbidity. Majority of efforts to understand the mechanisms of stenosis formation, and its prevention and management have largely focused on understanding and managing this complication based on the pathophysiology, tissue histology and molecular biology; however these efforts have not resulted in significant progress to date. We believe that the major impact in this area will come from continued and accurate understanding of the hemodynamics, and by development of techniques of intervention to modulate factors such as flow rates, pressures and compliance of the circuit.The goal of this paper is to study anastomotic models of AV access using Computational Fluid Dynamics (CFD) and optimize them to minimize the wall shear stress (WSS). In order to achieve this goal, the commercial CFD software FLUENT [3] is employed in conjunction with a single objective genetic algorithm [4].Computations for two types of AVF currently in use in clinical practice are performed. AVF with 25° angle/3–4mm diameter and 90° angle/3–5mm diameter are selected to conduct the optimization. A single-objective genetic algorithm is employed in the optimization process and a k-kl-ω turbulence model is employed in CFD simulations; this model can accurately compute transitional/turbulent flows. In order to optimize for the same flow conditions, a fixed boundary condition is used during the optimization process. Computations for 16 to 20 generations of the selected AVFs are obtained from the genetic algorithm solver. The maximum WSS in the two AVFs considered are 6997.8 and 7750 dynes/cm2; however, the maximum WSS in the shape-optimized AVFs are reduced to 3511.2 and 4293.9 dynes/cm2 respectively, which have decreased by 49.82% and 44.59% respectively. Thus, the probability of the formation of stenosis in AVFs and early failure rates of vascular access are reduced by using the optimized AVFs.Copyright © 2015 by ASME